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  |Keith Barnett/RTP/USEPA/US                                                               

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  |Cortney_Higgins@omb.eop.gov                                                               

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  |Charlotte Bertrand/DC/USEPA/US@EPA, Walton.Tom@epamail.epa.gov, Steven

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  |Steve Fruh/RTP/USEPA/US@EPA                                                              

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  |08/06/2010 12:04 AM                                                                       

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  |Revised Preamble                                                                          

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Dear Courtney:

Here is the revised rule and preamble. I think we have disposed of all the

comments, with preamble changes or separate responses. We are still working on

the changes to the RIA and have not updated the preamble section on economic

impacts that come form the RIA.  The ISIS section is current.

Note that we have changes the discussion on the two high emitting kilns.

Based in information recently received, we are confident that these facilities

will be able to come into compliance with the mercury limit.

We also note that, in the case of Ash Grove, their initial costs will actually be

lower than many kilns because they are an area source and thus not subject to the

HCl emissions limit.

As I noted previously, We now have an example of a kiln that was exceeding the

mercury emissions limit by a factor of 100 (they were emitting 400 ug/dscm, the

standard is 41).  This facility has been able to reduce emission without adding

any mercury controls simply by shuttling cement kiln dust.  Based on this

information, and the fact that we know that the Durkee facility has extremely

high mercury level in their cement kiln dust (high mercury levels make dust

shuttling more effective), we anticipate that the Ash Grove kiln will be able to

meet the limit, either through dust shuttling or treatment of the dust to remove

the mercury.  .  And as you are now aware, EPA is looking into the possibility of

some type of compliance schedule that could allow them more than the 3‐4 years

normally required.

(See attached file: PREAMBLE‐RULE Cement‐OMB August 5PM.docx)

Keith W. Barnett

USEPA/OAQPS/SPPD/MMG

Mail Code D243‐02

Research Triangle Park, NC  27711

919‐541‐5605

barnett.keith@epa.gov
6560-50-P

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 60 and 63

[EPA-HQ-OAR-2007-0877; FRL - ]

RIN 2060-AO42

[EPA-HQ-OAR-2002-0051; FRL- ]

RIN 2060-AO15

National Emission Standards for Hazardous Air Pollutants From

the Portland Cement Manufacturing Industry and Standards of 

Performance for Portland Cement Plants

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

SUMMARY: EPA is finalizing amendments to the National Emission 

Standards for Hazardous Air Pollutants (NESHAP) from the 

Portland Cement Manufacturing Industry and to the New Source 

Performance Standards (NSPS) for Portland Cement Plants.

The final amendments to the NESHAP add or revise, as 

applicable, emission limits for mercury, total hydrocarbons 

(THC), and particulate matter (PM) from new and existing kilns 

located at major and area sources, and for hydrochloric acid 

(HCl) from new and existing kilns located at major sources. The 

standards for new kilns apply to facilities that commence 

construction, modification, or reconstruction after May 6, 2009. 

The final amendments to the NSPS add or revise, as 

applicable, emission limits for PM, opacity, nitrogen oxides
Page 2 of 456

(NOx), and sulfur dioxide (SO2) for facilities that commence 

construction, modification, or reconstruction after June 16, 

2008. The final rule also includes additional testing and 

monitoring requirements for affected sources. 

DATES: These final rules are effective on [INSERT DATE 60 DAYS 

FROM PUBLICATION OF THESE AMENDMENTS IN THE FEDERAL REGISTER]. 

The incorporation by reference of certain publications listed in 

this rule is approved by the Director of the Federal Register on 

[INSERT DATE 60 DAYS FROM DATE OF PUBLICATION IN THE FEDERAL 

REGISTER].

ADDRESSES: EPA has established two separate dockets for these

actions: Docket ID No. EPA-HQ-OAR-2007-0877 for the amendments 

to the NSPS and Docket ID No. EPA-HQ-OAR-2002-0051 for the 

amendments to the NESHAP. All documents in the two dockets are 

listed in the http://www.regulations.gov index. Certain other 

material, such as copyrighted material, will be publicly 

available only in hard copy. Publicly available docket 

materials are available either electronically in 

http://www.regulations.gov or in hard copy at the EPA Docket 

Center, Standards of Performance 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-
Page 3 of 456

1744, and the telephone number for the Docket Center is (202) 

566-1742.

FOR FURTHER INFORMATION CONTACT: Mr. Keith Barnett; Office of 

Air Quality Planning and Standards; Sector Policies and Programs 

Division, Metals and Minerals Group (D243-02); Environmental 

Protection Agency; Research Triangle Park, NC 27711; telephone 

number: (919) 541-5605; fax number: (919) 541-5450; e-mail 

address: barnett.keith@epa.gov.

SUPPLEMENTARY INFORMATION:

The supplementary information presented in this preamble is 

organized as follows:

I. General Information

A. Does this action apply to me?

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

C. Judicial Review

II. Background Information on the NESHAP, 40 CFR part 63, 

subpart LLL

A. What is the statutory basis for the NESHAP in 40 CFR part 63, 

 subpart LLL?

B. Summary of the National Lime Association v. EPA Litigation

C. EPA‘s Response to the Remand

D. Reconsideration of EPA Final Action in Response to the Remand

III. Background Information from the NSPS 40 CFR part 60, 

subpart F

IV. Summary of EPA‘s Final Action on Amendments

A. What are EPA‘s Final Actions on 40 CFR part 63, subpart LLL?

B. What are EPA‘s Final Actions on 40 CFR 

 part 60, subpart F?

C. What is EPA‘s Sector-Based Approach?

V. Responses to Major Comments

A. What are the significant comments and responses on 40 CFR 

part 63, subpart LLL? 

B. What are the significant comments and responses on 40 CFR 

part 60, subpart F?

VI. Summary of Cost, Environmental, Energy, and Economic 

Impacts of the Final Amendments to subpart LLL and subpart F
Page 4 of 456

VII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

B. Paperwork Reduction Act

C. Regulatory Flexibility Act

D. Unfunded Mandates Reform Act

E. Executive Order 13132: Federalism 

F. Executive Order 13175: Consultation and Coordination with 

Indian Tribal Governments

G. Executive Order 13045: Protection of Children from

Environmental Health Risks and Safety Risks

H. Executive Order 13211: Actions Concerning Regulations That 

Significantly Affect Energy Supply, Distribution, or Use

I. National Technology Transfer Advancement Act

J. Executive Order 12898: Federal Actions to Address 

Environmental Justice in Minority Populations and Low-Income 

Populations

K. Congressional Review Act

I. General Information

A. Does this action apply to me?

Categories and entities potentially regulated by this final 

rule include: 

Category NAICS 

code1

Examples of regulated entities

Industry.... 327310 Portland cement manufacturing

plants.

Federal government... Not affected.

State/local/tribal 

government...

Portland cement manufacturing 

plants.

1 North American Industry Classification System.

This table is not intended to be exhaustive, but rather provides 

a guide for readers regarding entities likely to be regulated by 

this action. To determine whether your facility will be 

regulated by this action, you should examine the applicability 

criteria in 40 CFR 60.60 (subpart F) or in 40 CFR 63.1340 
Page 5 of 456

(subpart LLL). If you have any questions regarding the 

applicability of this final action to a particular entity, 

contact the person listed in the preceding FOR FURTHER 

INFORMATION CONTACT section.

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

In addition to being available in the docket, an electronic 

copy of this final action is available on the Worldwide Web 

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

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

TTN‘s policy and guidance page for newly proposed or promulgated 

rules at http://www.epa.gov/ttn/oarpg. The TTN provides 

information and technology exchange in various areas of air 

pollution control.

C. Judicial Review

Under section 307(b)(1) of the Clean Air Act (CAA), 

judicial review of these final rules are available only by 

filing a petition for review in the United States Court of 

Appeals for the District of Columbia Circuit by [INSERT DATE 60 

DAYS FROM DATE OF PUBLICATION IN THE FEDERAL REGISTER]. Under 

section 307(b)(2) of the CAA, the requirements established by 

these final rules may not be challenged separately in any civil 

or criminal proceedings brought by EPA to enforce these 

requirements.
Page 6 of 456

Section 307(d)(7)(B) of the CAA further provides that 

―[o]nly an objection to a rule or procedure which was raised 

with reasonable specificity during the period for public comment 

(including any public hearing) may be raised during judicial 

review.‖ This section also provides a mechanism for EPA to 

convene a proceeding for reconsideration, ―[i]f the person 

raising an objection can demonstrate to EPA that it was 

impracticable to raise such objection within [the period for 

public comment] or if the grounds for such objection arose after 

the period for public comment (but within the time specified for 

judicial review) and if such objection is of central relevance 

to the outcome of the rule.‖ Any person seeking to make such a 

demonstration to us should submit a Petition for Reconsideration 

to the Office of the Administrator, U.S. EPA, Room 3000, Ariel 

Rios Building, 1200 Pennsylvania Ave., NW., Washington, DC 

20460, with a copy to both the person(s) listed in the preceding 

FOR FURTHER INFORMATION CONTACT section, and the Associate 

General Counsel for the Air and Radiation Law Office, Office of 

General Counsel (Mail Code 2344A), U.S. EPA, 1200 Pennsylvania

Ave., NW., Washington, DC 20460.

II. Background Information on the NESHAP, 40 CFR part 63, 

subpart LLL

A. What is the statutory basis for the NESHAP in 40 CFR part

63, subpart LLL?
Page 7 of 456

Section 112 of the CAA establishes a regulatory process to

address emissions of hazardous air pollutants (HAP) from

stationary sources. After EPA has identified categories of

sources emitting one or more of the HAP listed in section 112(b)

of the CAA, section 112(d) requires us to promulgate NESHAP for

those sources. For ―major sources‖ that emit or have the

potential to emit 10 tons per year (tpy) or more of a single HAP 

or 25 tpy or more of a combination of HAP, these technologybased standards must reflect the maximum reductions of HAP 

achievable (after considering cost, energy requirements, and 

non-air quality health and environmental impacts) and are 

commonly referred to as maximum achievable control technology 

(MACT) standards.

The statute specifies certain minimum stringency 

requirements for MACT standards, which are referred to as 

―floor‖ requirements. See CAA section 112(d)(3). Specifically, 

for new sources, the MACT floor cannot be less stringent than 

the emission control that is achieved in practice by the best

controlled similar source. The MACT standards for existing

sources can be less stringent than standards for new sources,

but they cannot be less stringent than the average emission

limitation achieved by the best-performing 12 percent of

existing sources (for which the Administrator has emissions 

information) in the category or subcategory (or the best-
Page 8 of 456

performing five sources for categories or subcategories with

fewer than 30 sources). 

In developing MACT, we must also consider control options 

that are more stringent than the floor. We may establish 

standards more stringent than the floor based on the 

consideration of the cost of achieving the emissions reductions, 

any non-air quality health and environmental impacts, and energy 

requirements. CAA section 112(d)(2).

Section 112(k)(3)(B) of the CAA requires EPA to identify at 

least 30 HAP that pose the greatest potential health threat in 

urban areas, and section 112(c)(3) requires EPA to regulate, 

under section 112(d) standards, the area source1 categories that 

represent 90 percent of the emissions of the 30 ―listed‖ HAP 

(―urban HAP‖). We implemented these listing requirements 

through the Integrated Urban Air Toxics Strategy (64 FR 38715, 

July 19, 1999).2

The Portland cement manufacturing source category was 

listed for regulation under this 1999 Urban Strategy based on 

emissions of arsenic, cadmium, beryllium, lead, and 

polychlorinated biphenyls (PCB). The final NESHAP for the 

 

1 An area source is a stationary source of HAP emissions that is 

not a major source. A major source is a stationary source that 

emits or has the potential to emit 10 tpy or more of any HAP or 

25 tpy or more of any combination of HAP.

2 Since its publication in the Integrated Urban Air Toxics 

Strategy in 1999, EPA has amended the area source category list 

several times.
Page 9 of 456

Portland Cement Manufacturing Industry (64 FR 31898, June 14, 

1999) included emission limits based on performance of MACT for 

the control of THC emissions from area sources. This 1999 rule 

fulfills the requirement to regulate area source cement kiln 

emissions of PCB (for which THC is a surrogate). However, EPA 

did not include requirements for the control of the non-volatile 

metal HAP (arsenic, cadmium, beryllium, and lead) from area 

sources in the 1999 rule or in the 2006 amendments. To fulfill 

our requirements under CAA section 112(c)(3) and 112(k), EPA is 

thus setting emissions standards for these metal HAP from 

Portland cement manufacturing facilities that are area sources 

(using PM as a surrogate). In this final rule EPA is 

promulgating PM standards for area sources based on performance 

of MACT, PM being a surrogate for these (and other non-volatile) 

HAP metals. 

Section 112(c)(6) requires that EPA list categories and 

subcategories of sources assuring that sources accounting for 

not less than 90 percent of the aggregate emissions of each of 

seven specified HAP are subject to standards under section 

112(d)(2) or (d)(4). The seven HAP are as follows: alkylated 

lead compounds; polycyclic organic matter; hexachlorobenzene; 

mercury; polychlorinated byphenyls; 2,3,7,8-

tetrachlorodibenzofurans; and 2,3,7,8-tetrachloroidibenzo-pdioxin. Standards established under CAA section 112(d)(2) must 
Page 10 of 456

reflect the performance of MACT. ―Portland cement 

manufacturing: non-hazardous waste kilns‖ is listed as a source 

category pursuant to CAA section 112(c)(6) due to emissions of 

polycyclic organic matter (POM), mercury, and dioxin/furans. 

Consistent with the requirements of CAA section 112(c)(6), we 

set MACT standards for these pollutants. 63 FR 17838, 17848, 

April 10, 1998; see also 63 FR at 14193 (March 24, 1998) (area 

source cement kilns‘ emissions of mercury, dibenzo-p-dioxins and 

dibenzo-p-furans, POM, and PCB are subject to MACT).

Section 129(a)(1)(A) of the CAA requires EPA to establish 

specific performance standards, including emission limitations, 

for "solid waste incineration units" generally, and, in 

particular, for "solid waste incineration units combusting 

commercial or industrial waste" (CAA section 129(a)(1)(D)).3

Section 129 of the CAA defines "solid waste incineration 

unit" as "a distinct operating unit of any facility which 

combusts any solid waste material from commercial or industrial 

establishments or the general public." CAA Section 129(g)(1). 

CAA Section 129 also provides that ―solid waste‖ shall have the 

meaning established by EPA pursuant to its authority under the 

Resource Conservation and Recovery Act (RCRA). Section 

129(g)(6). 

 

3 CAA section 129 refers to the Solid Waste Disposal Act (SWDA). 

However, this Act, as amended is commonly referred to as RCRA. 

 
Page 11 of 456

In Natural Resources Defense Council v. EPA, 489 F. 3d 

1250, 1257-61 (D.C. Cir. 2007), the Court vacated the Commercial 

and Industrial Solid Waste Incineration Units (CISWI) 

Definitions Rule, 70 FR 55568 (Sept. 22, 2005), which EPA issued 

pursuant to CAA section 129(a)(1)(D). 

In response to the Court‘s remand and vacatur of the CISWI 

Definitions rule, EPA initiated a rulemaking to identify which 

secondary materials are non-hazardous ―solid waste‖ for purposes 

of subtitle D (non-hazardous waste) of the RCRA when burned in a 

combustion unit. See 75 FR 31844 (June 4, 2010). Any final 

definition adopted in that rulemaking, in turn, will determine 

the applicability of CAA section 129(a) (i.e., any combustion 

unit that burns any non-hazardous secondary material that is 

considered to be a solid waste would be subject to CAA section 

129 requirements).

There is presently no federal regulatory interpretation of

―solid waste‖ for EPA to apply under Subtitle D of RCRA for 

purposes of CAA section 112 and 129. EPA is not prejudging, and 

cannot prejudge the outcome of the recently proposed nonhazardous solid waste rulemaking. EPA therefore cannot reliably 

determine at this time if the non-hazardous secondary materials 

combusted by cement kilns are to be classified as solid wastes. 

Accordingly, EPA is basing all determinations as to source 

classification on the emissions information now available, as 
Page 12 of 456

required by CAA section 112 (d)(3), and will necessarily 

continue to do so until the solid waste definition discussed 

above is promulgated. The current data base classifies all 

Portland cement kilns as CAA section 112 sources (i.e., subject 

to regulation under CAA section 112). 

We proposed amendments to the Portland Cement Manufacturing 

NESHAP on May 6, 2009. See 74 FR 21136. We received a total of 

3,229 comments from the Portland cement industry, environmental 

groups, State environmental agencies and others during the 

comment period. This final rule reflects our consideration of 

all the comments we received. Detailed responses to the 

comments not included in this preamble are contained in the 

Summary of Public Comments and Responses document, which is 

included in the docket for this rulemaking.

B. Summary of the National Lime Association v. EPA Litigation

On June 14, 1999 (64 FR 31898), EPA issued the NESHAP for 

the Portland Cement Manufacturing Industry (40 CFR part 63, 

subpart LLL).4 The 1999 final rule established emission 

limitations for PM as a surrogate for non-volatile HAP metals

 

4 Cement kilns which burn hazardous waste are a separate source 

category, since their emissions of many HAP differ from Portland

cement kilns‘ as a result of the hazardous waste inputs. Rules 

for hazardous waste-burning cement kilns are found at subpart 

EEE of part 63.
Page 13 of 456

(major sources only), dioxins/furans, and for greenfield5 new 

sources total THC as a surrogate for organic HAP. These 

standards were intended to be based on the performance of MACT 

pursuant to CAA sections 112 (d)(2) and (3). We did not 

establish limits for THC for existing sources and non-greenfield 

new sources, nor for HCl or mercury for new or existing sources. 

We reasoned that emissions of these constituents were a function 

of raw material concentrations and so were essentially 

uncontrolled, the result being that there was no level of 

performance on which a floor could be based. EPA further found 

that beyond the floor standards for these HAP were not 

warranted. 

Ruling on petitions for review of various environmental 

groups, the D.C. Circuit held that EPA had erred in failing to 

establish CAA section 112 (d) standards for mercury, THC (except 

for greenfield new sources) and HCl. The court held that

―[n]othing in the statute even suggests that EPA may set 

emission levels only for those ... HAPs controlled with 

technology.‖ National Lime Ass‘n v. EPA, 233 F. 3d 625, 633 

(D.C. Cir. 2000). The court also stated that EPA is obligated 

to consider other pollution–reducing measures such as process 

 

5 For purposes of the 1999 rule a new greenfield kiln is a kiln 

constructed after March 24, 1998, at a site where there are no 

existing kilns. 
Page 14 of 456

changes and material substitution. Id. at 634. Later cases go 

on to hold that EPA must account for levels of HAP in raw 

materials and other inputs in establishing MACT floors, and 

further hold that sources with low HAP emission levels due to 

low levels of HAP in their raw materials can be considered best 

performers for purposes of establishing MACT floors. See, e.g., 

Sierra Club v. EPA (―Brick MACT‖), 479 F. 3d 875, 882-83 (D.C. 

Cir. 2007).6 

C. EPA‘s Response to the Remand 

 In response to the National Lime Ass‘n mandate, on December 

2, 2005, we proposed standards for mercury, THC, and HCl. (More 

information on the regulatory and litigation history may be 

found at 70 FR 72332, December 2, 2005.) We received over 1,700 

comments on the proposed amendments. Most of these comments 

addressed the lack of a mercury emission limitation in the 

proposed amendments. On December 20, 2006 (71 FR 76518), EPA 

published final amendments to the NESHAP. The 2006 amendments 

contained a new source standard for mercury emissions from 

cement kilns and kilns/in-line raw mills of 41 micrograms per 

dry standard cubic meter, or alternatively the application of a 

 

6 In the remainder of the opinion, the Court in National Lime 

Ass‘n upheld EPA‘s standards for PM and dioxin (on grounds that 

petitioner had not properly raised arguments in its opening 

brief), upheld EPA‘s use of PM as a surrogate for HAP metals, 

and remanded for further explanation EPA‘s choice of an analytic 

method for HCl.
Page 15 of 456

limestone wet scrubber with a liquid-to-gas ratio of 30 gallons 

per 1,000 actual cubic feet per minute of exhaust gas. The 

final rule also adopted a standard for new and existing sources 

banning the use of utility boiler fly ash in cement kilns where 

the fly ash mercury content has been increased through the use 

of activated carbon or any other sorbent unless the cement kiln 

seeking to use the fly ash can demonstrate that the use of fly 

ash will not result in an increase in mercury emissions over its 

baseline mercury emissions (i.e., emissions not using the 

mercury-laden fly ash). EPA also issued a THC standard for new 

cement kilns (except for greenfield cement kilns that commenced 

construction on or before December 2, 2005) of 20 parts per 

million (corrected to 7 percent oxygen) or 98 percent reduction 

in THC emissions from uncontrolled levels. EPA did not set a 

standard for HCl, determining that HCl was a pollutant for which 

a threshold had been established, and that no cement kiln, even 

under conservative operating conditions and exposure 

assumptions, would emit HCl at levels that would exceed that 

threshold level, allowing for an ample margin of safety. EPA 

pointed to CAA section 112(d)(4) authority as its rationale for 

not establishing HCl emissions limits.

D. Reconsideration of EPA Final Action in Response to the 

Remand 
Page 16 of 456

At the same time we issued the final amendments, EPA on its 

own initiative made a determination to reconsider the new source 

standard for mercury, the existing and new source standard 

banning cement kiln use of certain mercury-containing fly ash, 

and the new source standard for THC (71 FR 76553, December 20, 

2006). EPA granted reconsideration of the new source mercury 

standard both due to substantive issues relating to the 

performance of wet scrubbers and because information about their 

performance in the industry had not been available for public 

comment at the time of proposal; that information is now 

available in the docket. We also committed to undertake a test 

program for mercury emissions from cement kilns equipped with 

wet scrubbers that would enable us to resolve these issues. We 

further explained that we were granting reconsideration of the 

work practice requirement banning the use of certain mercurycontaining fly ash in cement kilns to allow further opportunity 

for comment on both the standard and the underlying rationale 

and because we did not feel we had the level of analysis we 

would like to have to support a beyond-the-floor determination. 

We granted reconsideration of the new source standard for THC 

because the information on which the standard was based arose 

after the period for public comment. We requested comment on 

the actual standard, whether the standard is appropriate for 

reconstructed new sources (if any should occur) and the 
Page 17 of 456

information on which the standard is based. We specifically 

solicited data on THC emission levels from preheater/precalciner 

cement kilns. We stated that we would evaluate all data and 

comments received, and determine whether in light of those data 

and comments it was appropriate to amend the promulgated 

standards. 

EPA received comments on the notice of reconsideration from 

two cement companies, three energy companies, three industry 

associations, a technical consultant, one State, one 

environmental group, one ash management company, one fuels 

company, and one private citizen. As part of these comments, 

one industry trade association submitted a petition to withdraw 

the new source MACT standards for mercury and THC and one 

environmental group submitted a petition for reconsideration of 

the 2006 final action. A summary of these comments is available 

in the docket for this rulemaking.7

In addition to the reconsideration discussed above, EPA 

received a petition from Sierra Club requesting reconsideration 

of the existing source standards for THC, mercury, and HCl, and 

judicial petitions for review challenging the final amendments. 

EPA granted the reconsideration petition. The judicial 

 

7 Summary of Comments on December 20, 2006 Final Rule and Notice 

of Reconsideration. April 15, 2009.
Page 18 of 456

petitions have been combined and are being held in abeyance 

pending the results of the reconsideration.

In March 2007 the D.C. Circuit Court issued an opinion 

(Sierra Club v. EPA, 479 F.3d 875 (D.C. Cir. 2007)(Brick MACT)) 

vacating and remanding CAA section 112(d) MACT standards for the 

Brick and Structural Clay Ceramics source categories. Some key 

holdings in that case were:

 Floors for existing sources must reflect the average 

emission limitation achieved by the best performing 12 

percent of existing sources, not levels EPA considers to be 

achievable by all sources (479 F. 3d at 880-81); 

 EPA cannot set floors of ―no control.‖ The Court 

reiterated its prior holdings, including National Lime 

Ass‘n, confirming that EPA must set floor standards for all 

HAP emitted by the major source, including those HAP that 

are not controlled by at-the-stack control devices (479 F. 

3d at 883); and

 EPA cannot ignore non-technology factors that reduce HAP 

emissions, including when determining which sources are 

best performers for purposes of ascertaining the MACT 

floor. Specifically, the Court held that ―EPA‘s decision 

to base floors exclusively on technology even though nontechnology factors affect emissions violates the Act.‖ (479 

F. 3d at 883). 
Page 19 of 456

Based on the statute, as interpreted in the Brick MACT

decision, we believe a source‘s performance resulting from the 

presence or absence of HAP in raw materials must be accounted 

for in establishing floors; i.e., a low emitter due to low HAP 

proprietary raw materials can still be a best performer. In 

addition, the fact that a specific level of performance is not 

being intentionally achieved by the source is not a legal basis 

for excluding the source‘s performance from consideration. 

Sierra Club v. EPA, 479 F.3d at 631-34; National Lime Ass‘n, 233 

F. 3d at 640.

The Brick MACT decision also reiterated that EPA may 

account for variability in setting floors. However, the Court 

found that EPA erred in assessing variability because it relied 

on data from the worst performers to estimate best performers‘ 

variability, and held that ―EPA may not use emission levels of 

the worst performers to estimate variability of the best 

performers without a demonstrated relationship between the two.‖ 

479 F. 3d at 882.

After considering the implications of this decision, EPA 

granted the petition for reconsideration of all the existing 

source standards in the 2006 rulemaking.

A second Court opinion of relevance to the Portland cement 

NESHAP amended here is Sierra Club v. EPA, 551 F. 3d 1019 (D.C. 

Cir. 2008). In that case, the court vacated the regulations 
Page 20 of 456

contained in the General Provisions which exempt major sources

from CAA section 112(d) standards during periods of startup, 

shutdown and malfunction (SSM). The regulations (in 40 C.F.R. 

63.6(f)(1) and 63.6(h)(1)) provided that sources need not comply 

with the relevant CAA section 112(d) standard during SSM events 

and instead must ―minimize emissions . . . to the greatest 

extent which is consistent with safety and good air pollution 

control practices.‖ The current Portland Cement NESHAP 

references the now-vacated rules in the General Provisions. As 

a result of the court‘s decision, we are removing the references 

to the vacated provisions and addressing SSM in this rulemaking. 

Discussion of this issue may be found in Section IV.A.

III. Background Information on the NSPS 40 CFR part 60, subpart

F

NSPS implement CAA section 111(b) and are issued for 

categories of sources which cause, or contribute significantly 

to, air pollution which may reasonably be anticipated to 

endanger public health or welfare. The primary purpose of the 

NSPS is to attain and maintain ambient air quality by ensuring 

that the best demonstrated emission control technologies are 

installed as the industrial infrastructure is modernized. Since 

1970, the NSPS have been successful in achieving long-term 

emissions reductions in numerous industries by assuring cost-
Page 21 of 456

effective controls are installed on new, reconstructed, or 

modified sources.

Section 111 of the CAA requires that NSPS reflect the 

application of the best system of emission reductions which,

taking into consideration the cost of achieving such emission 

reductions, any non-air quality health and environmental impact 

and energy requirements, the Administrator determines has been 

adequately demonstrated. This level of control is commonly 

referred to as best demonstrated technology (BDT). EPA 

promulgated Standards of Performance for Portland Cement Plants 

(40 CFR, part 61 subpart F) in 1971((36 FR 24876, December 23, 

1971). 

Section 111(b)(1)(B) of the CAA requires EPA to 

periodically review and revise the standards of performance, as 

necessary, to reflect improvements in methods for reducing 

emissions. We have conducted three reviews of the standards (39 

FR 20793, June 14, 1974; 39 FR 39874, November 12, 1974; and 53 

FR 50354, December 14, 1988).

We proposed the current review of the Portland Cement Plant 

NSPS on June 16, 2008. We received a total of 46 comments from 

the Portland cement industry, environmental groups, State 

environmental agencies and others during the comment period. 

This final rule reflects our consideration of all the comments 

we received. Detailed responses to the comments not included in 
Page 22 of 456

this preamble are contained in the Summary of Public Comments 

and Responses document which is included in the docket for this 

rulemaking.

IV. Summary of EPA’s Final Action on the Amendments 

In this section we discuss the final amendments to 40 CFR 

part 63 subpart LLL and part 60 subpart F, the changes since 

proposal, and the rationale for the changes. Responses to 

specific comments may be found in the response to comment 

section of this document or in the response to comment documents 

contained in the dockets for this rulemaking.

As a preliminary matter, EPA notes that certain portions of 

the existing rules are not being amended substantively but are 

being reprinted, sometimes with editorial changes, in today‘s 

regulatory text. As explained at proposal, EPA did so either 

for readers' convenience or to make certain non-substantive 

'plain English' changes to rule text. 74 FR at 21140. The 

final rule text makes these same non-substantive changes (which 

did not occasion public comment), and reprints certain existing 

provisions. Provisions from the existing rules which do not 

change substantively include the PM emission limits for kilns 

currently subject to the NSPS, the opacity limits for raw 

materials dryers, raw mills, and finish mills, and the limits 

for dioxin furan (D/F)for cement kilns. We reorganized the 

testing and monitoring requirements of both rules to make them 
Page 23 of 456

more consistent, and modified the rule language to better 

conform with the June 1, 1998, Executive Memorandum on Plain 

Language in Government Writing. 

A. What are EPA‘s Final Actions on 40 CFR part 63, subpart

LLL?

1. What are the final actions on emission limits under 40 CFR 

part 63, subpart LLL?

In this action, we are amending the emission limits for 

mercury, THC, and PM from new and existing kilns located at a 

major or area source, and for HCl from new and existing kilns 

located at major sources. We identify these standards below for 

the emission sources in a typical Portland cement production 

process. We have applied the limits for existing and new 

sources in this final rule for mercury and THC to area sources 

consistent with CAA section 112(c)(6). As noted above, mercury 

is one of the pollutants specifically singled out by Congress in 

CAA section 112(c)(6), and THC is a surrogate for POM and PCB, 

which are also section 112(c)(6) HAP. See 63 FR 14193, March 

24, 1998 (determination to control all THC emissions from the 

source category under MACT standards). Finally, Portland cement 

kilns are a listed area source category for urban HAP metals 

pursuant to CAA section 112(c)(3), and control of these metal 

HAP emissions (via the standard for the PM non-mercury HAP metal 
Page 24 of 456

surrogate) is required to ensure that area sources representing 

90 percent of the area source emissions of urban metal HAP are 

subject to CAA section 112 control, as required by CAA section 

112(c)(3). The PM standards for area sources reflect MACT, as 

explained below.

a. Changes to overall floor setting procedure

The MACT floor limits for each of the HAP and HAP 

surrogates (mercury, THC, HCl, and PM) are calculated based on 

the performance of the lowest emitting (considered best 

performing in this rulemaking) sources in each of the MACT floor 

pools for each HAP or HAP surrogate. We ranked all of the 

sources for which we had data based on their emissions and 

identified the lowest emitting 12 percent of the sources for 

which we had data, which ranged from two kilns for THC to 11 

kilns for mercury for existing sources. For new source MACT, 

the floor was based on the best controlled source. 

In assessing sources‘ performance, EPA may consider 

variability both in identifying which performers are ―best‖ and 

in assessing their level of performance. Brick MACT, 479 F. 3d 

at 881-82; see also Mossville Envt‘l Action Now v. EPA, 370 

F.3d 1232, 1241–42 (D.C. Cir 2004) (EPA must exercise its 

judgment, based on an evaluation of the relevant factors and 

available data, to determine the level of emissions control that 
Page 25 of 456

has been achieved by the best performing sources considering 

these sources‘ operating variability). 

Variability in cement kilns‘ performance has a number of 

causes. For many of the pollutants, notably mercury and THC, 

most kilns do not have add-on control devices. The main source 

of variability for these pollutants consequently is the 

differing mercury and organic concentrations in the raw 

materials and fuels which are fed to the kiln. For particulate 

matter, which is well-controlled by baghouses, the variability 

is chiefly due to variations in performance of the control 

device for which both run-to-run and test-to-test variability 

must be accounted.8

In determining the MACT floor limits, we first determine 

the floor, which, as explained above, for existing sources is

the level achieved in practice by the average of the top 12 

percent of existing sources, or the level achieved in practice 

by the best controlled similar source for new sources. In this 

 

8 Run-to-run variability is essentially within-test variability, 

and encompasses variability in individual runs comprising the 

compliance test, and includes uncertainties in correlation of 

monitoring parameters and emissions, and imprecision of stack 

test methods and laboratory analysis. 72 FR at 54877 (Sept. 27, 

2007). Test-to-test variability results from variability in 

pollution device control efficiencies over time (depending on 

many factors, including for fabric filters the point in the 

maintenance cycle in which a fabric filter is tested). Test-totest variability can be termed long-term variability. 72 FR at 

54878.
Page 26 of 456

rule, EPA is using lowest emissions as the measure of best 

performance. 

We then assess variability of the best performers by using

a statistical formula designed to estimate a MACT floor level 

that is equivalent to the average of the best performing sources 

based on future compliance tests (or calculated inputs in the 

case of mercury). Specifically, the MACT floor limit is an 

upper prediction limit (UPL) calculated with the Student‘s ttest using the TINV function in Microsoft Excel®. The Student‘s 

t-test has also been used in other EPA rulemakings (e.g., NSPS 

for Hospital/Medical/Infectious Waste Incinerators, NESHAP for

Industrial, Commercial, and Institutional Boilers and Process

Heaters) in accounting for variability. A prediction interval 

for a future observation is an interval that will, with a 

specified degree of confidence, contain the next (or some other 

pre-specified) randomly selected observation from a population. 

In other words, the prediction interval estimates what the upper 

bound of future values will be, based upon present or past 

background samples taken. The UPL consequently represents the 

value which we can expect the mean of future observations (3-run 

average for HCl, 30-day average for mercury, PM, HCl (sources 

not having wet scrubbers or otherwise electing CEM-based 

compliance), and THC) to fall below within a specified level of 

confidence, based upon the results of an independent sample from 
Page 27 of 456

the same population. In other words, if we were to randomly 

select a future test condition from any of these sources (i.e., 

average of 3 runs or 30-day average) we can be 99 percent 

confident that the reported level will fall at or below the UPL 

value. Use of the UPL is appropriate in this rulemaking because 

it sets a limit any single or future source can meet based on 

the performance of the MACT pool. 

This formula uses a pooled variance (in the s2 term) that 

encompasses all the data-point to data-point variability of the 

best performing sources comprising the MACT floor pool for each 

HAP. Where variability was calculated using the UPL statistical 

approach (i.e., for the Hg, HCl, and PM standards), we used the 

average (or sample mean) and sample standard deviation, which 

are two statistical measures calculated from the data 

distributions for mercury and PM. The average is a central 

value of a data set, and the standard deviation is the common 

measure of the dispersion of the data set around the average. 

We describe in detail in the preamble sections on mercury, HCl 

and PM and in the memorandum ―Floor Calculations for Final 

Portland Cement NESHAP, August 6, 2010‖ how these averages were 

developed. We note here that the methodology accounts for both 

long-term variability as well as run-to-run and test-to-test 

variability. 
Page 28 of 456

The formula also applies differently depending on how the 

underlying data set is distributed. To this end, EPA carefully 

evaluated the data sets for each HAP to ascertain whether the 

data were normally distributed, or distributed in some other 

manner (i.e., log normally). After applying standard and 

rigorous statistical tests (involving the degree of ―skewness‖ 

of the data), we determined that the distributions for mercury 

and particulate matter were approximately a normal distribution, 

which in turn determined the final form of the UPL equation. 

See Floor Calculations for Final Portland Cement NESHAP, August 

6, 2010; see also 75 FR at 32019-20. 

EPA was able to reasonably calculate variability for the 

THC and HCl standards without needing to use predictive 

statistics. Specifically, the data set for THC contains a 

sufficient number of observations to estimate the variability 

without the need of any type of statistical intervals (no UPL 

needed to be calculated). Although EPA applied the UPL formula 

in developing the HCl standard, the key issue for the HCl data 

set is the HCl analytic method‘s detection limit, which 

ultimately dictated the level of the standard. 

At proposal we adopted a form of the UPL equation that has 

been used in a previous rulemaking. 69 FR 21233 April 20, 2004. 

Commenters stated correctly that there was an error in the 

equation used at proposal. As a result of these comments, EPA
Page 29 of 456

corrected the formula in the final rule. The UPL used in the 

final rule is calculated by:

Where:

x ̄ = the mean of the sample data set

n = the number of test runs

m = the number of test runs in the compliance average

s

2 = observed variance 

t = student t distribution statistic

This calculation was performed using the following Excel 

functions:

Normal distribution: 99 percent UPL = AVERAGE(Test Runs in Top 

12percent) + [STDEV(Test Runs in Top 12percent) x TINV(2 x 

probability, n-1 degrees of freedom)*SQRT((1/n)+(1/m))], for a 

one-tailed t-value, probability of 0.01, and sample size of n 

This is the same UPL equation that EPA used in more recent 

rulemakings. See 75 FR 32020 (June 4, 2010) and 75 FR 31905

(June 4, 2010). The value of ―m‖ denotes the number of future 

observations, and it is used to calculate an estimate of the 

variance of the average of m-future observations. For example, 

if 30-day averages are used to determine compliance (m=30), the 

amount of variability in the 30-day average is much lower than 

the variability of the daily measurements in the data base, 

which results in a lower UPL for the 30-day average.

As an illustration of the effects that correcting the UPL 

had on the emission limits, we calculated the UPLs for mercury

and PM using the proposal version of the UPL formula, and the 

version used in this final rule. The results of these 
Page 30 of 456

calculations are presented in Table 1. Both calculated limits 

are about 20 percent lower when the corrected UPL formula is 

used. 

Table 1. Comparison Emission Limits Calculated using proposal 

UPL formula versus corrected UPL formula for existing sources.

 

Proposal (Uncorrected 

UPL Formula)

Proposal (Corrected 

UPL Formula)

Mercury, (lb/MM 

tons feed) 

[lb/MM tons 

clinker]

29.6

[48.8]

22.5

[37.1]

PM (lb/ton 

clinker)

0.05 0.04

b. Ramifications of EPA Statistical Approach. 

A number of commenters maintained that this final rule 

raises the (perceived) quandry voiced by Judge Williams in his 

concurring opinion in Brick MACT where an achieved level of 

performance for purposes of CAA section 112(d)(3)results in a 

standard which is unachievable under CAA section 112(d)(2) 

because it is too costly or not cost-effective. Brick MACT, 479 

F. 3d at 884-85. EPA is of course mindful of the repeated 

admonitions (with accompanying vacaturs and remands) from the 

D.C. Circuit that MACT floors must reflect achieved performance, 

that HAP content of process inputs (raw materials and fuels) 

must be accounted for in ascertaining sources‘ performance, and 

that costs cannot be considered by EPA in ascertaining the level 

of the MACT floor. See, e.g., Brick MACT, 479 F. 3d at 880-81, 

882-83; NRDC v. EPA, 489 F. 3d 1364, 1376 (D.C. Cir. 2007) 
Page 31 of 456

(―Plywood MACT‖); see also Cement Kiln Recycling Coalition v. 

EPA, 255 F. 3d 855, 861-62 (D.C. Cir. 2001) (―achievability‖ 

requirement of CAA section 112 (d)(2) cannot override the 

requirement that floors be calculated on the basis of what best 

performers actually achieved). EPA is also mindful of the need 

to account for sources‘ variability (both due to control device 

performance and variability in inputs) in assessing sources‘ 

performance when developing technology-based standards. See, 

e.g., Mossville Environmental Action Now v. EPA, 370 F. 3d 1232, 

1242 (D.C. Cir. 2004); National Lime I, 627 F. 2d 416,433-

34(D.C. Cir. 1980). EPA has carefully developed data for each 

standard, assessing both technological controls and HAP inputs 

in doing so. For mercury, EPA used the pooled variance from all 

of the best performing kilns in the MACT floor pool in order to 

fully assess these kilns‘ intra-quarry and other variable 

mercury levels. EPA also used pooled variance to assess the 

variability of HCl and PM emissions for the MACT floor pool 

kilns. See 70 FR at 59438 (Oct. 12, 2005) (explaining when use 

of such pooled variances can be reasonable). EPA has also 

adopted 30-day averaging periods for all of the standards, 

further allowing short term fluctuations to be averaged out over 

the 30-day period. 

The result are floors which reasonably estimate the 

performance over time of the best performing sources, as do the 
Page 32 of 456

standards based on those floors. It is true that many sources 

will need to install controls to meet these standards, and that 

these controls have significant costs (although EPA estimates 

that the rule‘s costs are substantially outweighed by its 

benefits). See Section VI below. This is part of the expected 

MACT process where, by definition, the averaged performance of 

the very best performers sets the minimum level of the standard. 

The Agency believes that it has followed the statute and 

applicable case law in developing its floor methodology.

Industry commenters nonetheless maintained that EPA had not 

properly accounted for variability of the best performing 

sources because not even these sources can meet the standards 

which are predicated on their own performance without adding 

controls. This contention lacks a basis in the record. For 

mercury, all performers in the MACT floor pool – not just those 

with emissions below the average of the best performers-- meet 

the promulgated standard (highest 30-day average in MACT pool is 

41.63 lb/MM tons clinker; the standard is 55 lb/MM tons clinker

(30-day average). In addition, two additional kilns, which are 

not in the pool of best performers, meet the standards. For 

THC, all kilns in the pool of best performers meet the 

promulgated standard (highest 30-day average in MACT pool is 

5.68 ppmv; the standard is 24 ppmv). In addition, seven 

additional kilns which are not in the pool of best performers 
Page 33 of 456

meet the standards. Indeed, nine of the 11 kilns for which EPA 

has CEM data are meeting the promulgated standards for THC. For 

PM, all six kilns in the MACT pool as well as twelve kilns 

overall meet the promulgated 30-day standard even though the 

measurements in the data base are stack tests (i.e. unlike for 

mercury and THC, these are not averaged values).9 Virtually all 

kilns in the MACT floor pool are meeting the HCl standard, 

although this is largely the result of setting the standard at a 

level reflecting analytic method quantitation limits. 

Commenters presented virtually no quantified data that 

floor plants are unable to meet the standards. See National 

Association of Metal Finishers v. EPA, 719 F. 2d 624, 649 (3d 

Cir. 1983) (unquantified assertions are entitled to little if 

any weight). Rather, their comments (comment 2845 at Table 1, 

echoed by many other industry commenters) provided narrative 

descriptions purporting to demonstrate that floor plants would 

not be able to achieve the standards.10 In those instances where 

commenters provided actual data on these plants‘ performance, 

EPA took the information into account in developing the final 

 

9 Development of The MACT Floors For The Final NESHAP For 

Portland Cement. August 6, 2010.

10 For example, the commenter asserted, without providing 

support, that the standards were ―achieved in practice, but not 

under foreseeable operations‖; ―achieved in practice based on 

limited stack tests‖; ―data shows that proposed standard was not 

achieved in practice when malfunction emission [sic] are 

included in compliance determination‖ (although no such data 

were provided to EPA). 
Page 34 of 456

standards. Indeed, EPA adjusted all of the standards based on 

actual data presented. However, EPA is not willing to act on 

pure supposition and conjecture regarding variability, 

particularly in the face of record information indicating that 

not only all floor plants but a number of additional plants are 

already meeting the promulgated standards.

c. Mercury Limits for Kilns.

i. Floor Determination. We proposed mercury 

emissions limits of 43 lb/million(MM) tons clinker for existing 

sources and 14 lb/MM tons clinker for new sources. The proposed 

floor was based on 30 days of data on all kiln inputs for 89 

kilns. See 74 FR at 21142-43. For all kilns but the five 

equipped with wet scrubbers, emissions were assumed to equal the 

total mass of mercury fed to each kiln. Scrubber-equipped kilns 

were considered to emit all mercury minus an assumed amount 

representing the average performance of the wet scrubbers. For 

kilns that waste cement kiln dust (CKD), the mercury component 

of the CKD was subtracted from inputs to calculate emissions. 

Id. By conducting a total mass balance for mercury and then 

assuming that all mercury inputted is emitted (minus 

conservatively estimated removals for scrubber usage and dust 

wastage), EPA made a near worst case assumption as to kilns‘ 

mercury emission levels. The kilns were then ranked from best 

to worst based on the extrapolated mercury emissions, normalized 
Page 35 of 456

to clinker production. EPA further proposed that no beyond the 

floor standard was appropriate for either existing or new 

sources. Id. at 21149. 

Since proposal we received updated data on certain kilns‘ 

raw materials usage and mercury content11 and used that data to 

revise our average mercury emissions estimates from the best 

performing kilns at proposal.12 We have also revised upward the 

floor kilns‘ projected emissions based on their reasonably 

estimated intra-quarry variability (explained further below). 

As a result, estimated emissions from some kilns increased, and 

one of the kilns in the group of sources used to set the 

existing source floor is no longer one of the best performing 

kilns. At proposal, the average mercury emissions of the top 12 

percent of the kilns was 27.4 pounds per million (lb/MM) tons 

clinker, and the average emissions of the best performing source 

were 13.4 lb/MM ton clinker. After revising our mercury 

emissions estimates, the averages were 32 and 14 lb/MM tons 

clinker, respectively, as shown in Table 2. 

Table 2. Mercury MACT Floor

Kiln code Mercury emissions (lb/MM ton feed)

1589 8.48

 

11 See Portland Cement Association Comments on the NESHAPProposed Rule (Docket Number: EPA-HQ-OAR-2002-0051)(September 

4, 2009) at pp. 31-35.

12 Development of The MACT Floors For The Final NESHAP For 

Portland Cement, August 6, 2010. 
Page 36 of 456

1650 9.53

1315 15.26

1302 15.28

1248 16.63

1259 21.33

1286 22.65

1594 25.23

1435 25.51

1484 25.51

1364 25.91

MACT - Existing Kilns

Average: lb/MM tons 

feed (lb/MM tons 

clinker)

19.21 (31.7)

Total variance 272.3

UPL: lb/MM tons feed 

(lb/MM tons clinker)

32.8(54.1)

MACT - New Kilns

Average: lb/MM tons 

feed (lb/MM tons 

clinker)

8.48 (14.0)

Total variance 35.2

UPL: lb/MM tons feed 

(lb/MM tons clinker)

12.3 (20.3)

 As noted above, we are taking into account operating 

variability of the best performing kilns, or in the case of new 

source MACT the single best controlled kiln, in assessing their 

performance (i.e., both in determining which performers are 

best, and calculating what their performance is). When we 

calculated the UPL with 99 percent confidence for the best 

performing sources (or in the case of new source MACT the best 

controlled single source), we calculated a mercury floor of 55

lb/MM tons clinker for existing sources and 21 lb/MM tons 
Page 37 of 456

clinker for new sources. Both are based on a 30-day rolling 

average. We chose a 30-day averaging period for the mercury 

emission limit. As noted above, the use of a 30 day average (as 

opposed to hourly or daily averages) tends to reduce 

variability, and also best reflects the nature of the data from 

which the floor was derived and assures that several operating 

cycles of raw mill on and off are included in each average. Id.

at 21144.

Industry commenters stated that we should account for 

additional sources of variability in this floor determination, 

namely intra-quarry variability and variability of the mercury 

content in local coals which kilns could utilize. As explained 

below, beyond those situations where commenters documented that 

sources actually used inputs with greater mercury content than 

used during the 30-day test period (see note 11 above), or 

where further intra-quarry mercury variability could reasonably 

be estimated, we did not do so. 

EPA is of course aware that limestone quarries are immense, 

and are customarily used from periods of 50 to 100 years. 

Taking the average of 30 days of sampling data from one part of 

the quarry would not necessarily encompass all of the different 

mercury levels throughout the quarry. 
Page 38 of 456

Although industry commenters originally raised the issue of 

long term intra-quarry variability during the initial May 2007 

30-day data collection, no plant chose to perform additional 

sampling and analysis of their raw materials and feed that would 

have allowed this issue to be directly addressed. Certain 

industry commenters did point, however, to data from the 30-day 

sampling effort as providing useful information on potential 

intra-quarry mercury variability of the two best performers. 

The data come from 30-day sampling conducted at four sources 

(three of which are located at a single facility), which all 

quarry limestone from a common geologic limestone formation.13 

All six kilns (the two floor kilns, and the other four kilns in 

the immediate vicinity) are in the same city and within 9 miles 

of each other. It is a reasonable assumption that variability of 

mercury levels (as opposed to mercury levels themselves) across 

this formation are substantially the same and therefore that the 

variability of mercury levels in the two best performers‘ 

quarries can be adjusted to reflect the variability seen in the 

other quarries which are part of the common geologic formation. 

See Brick MACT, 479 F. 3d at 881-882 (EPA may look at 

performance of sources which are not among the best in 

estimating variability of best performers if there is a 

 

13 Memorandum. Intra-quarry Variability Estimate, July 21, 2010.

 
Page 39 of 456

demonstrated relationship between the two). EPA further applied 

these estimates of intra-quarry variability to the mercury data 

for the other best performing kilns (i.e. applied the same RSD 

to the other best performing sources). EPA did so to more 

robustly characterize long-term variability of these sources‘ 

quarries‘ mercury levels. The fact that intra-quarry 

variability of the two lowest emitting sources increased 

somewhat after examination with other quarries in the common 

geologic formation confirms that there can be further 

variability. Since the intra-quarry variability comes from 

quarries servicing the two lowest emitting kilns, EPA would not 

expect intra-quarry variability to be lower for the other best 

performing sources.. In no other instance did commenters provide 

data that we could use to determine intra-quarry variability for 

kilns in the MACT floor pool.14 

Commenters also maintained that because cement kilns can 

burn different types of coal, variability of coal mercury 

content needs to be factored into estimates of sources‘ 

 

14 For example, one industry commenter submitted core (unground, 

unprocessed) samples from its quarry which samples differed in 

mercury content by approximately one order of magnitude. This 

facility is not a best performer, the samples are single 

measurements (rather than 30-day measurements or some longer 

duration), and (unlike the 30-day measurements used as the basis 

for the standard) have not been processed (i.e. passed through 

the quarry crushers and mixed in the storage pile which would 

tend to make the material more homogeneous). Therefore, these 

data are not comparable to the data used to set the MACT floors.
Page 40 of 456

performance. Commenters maintained that they obtained coal from 

a ―local market‖ and so might eventually use any coal from that 

market. The comments did not further link coal to individual 

mines or to other particularized sources. Commenters appear to 

be asking for an upward adjustment of the MACT floors based on 

coal they might potentially use but never had used. EPA 

believes that allowing for any inputs that might conceivably be 

used in the future, including from sources in an area which a 

source has never used to date, goes beyond a reasonable estimate 

of performance over time and invites inflated estimates of 

variability based only on hypothesized possibilities, not on 

actual behavior.15 EPA not only does not believe such 

methodology is a reasonable means of calculating sources‘ 

achieved performance, but also believes that such an approach 

creates a perverse incentive to build in compliance margins 

based on seeking out more polluted inputs. 

For example, the price of lower mercury coal may increase 

as a result of this rule (it may be more desirable as a means of 

keeping mercury emissions low), so plants may seek out higher 

mercury coal which they otherwise have never used. This type of 

volitional activity does not seem to be within the ambit of 

normal variability of process inputs. In addition, facilities 

 

15 The situation differs from use of limestone from a proprietary 

quarry. Not only have sources used the quarry in the past but 

will necessarily continue to do so in the future.
Page 41 of 456

do have choices for coal. As noted in the comments, some 

facilities obtain coals from several states, while others appear 

to limit themselves to more local areas. However, coal is a 

commodity that can be transported long distances to fuel utility 

boilers. Therefore, we believe that a facility should have 

sufficient coals available that they would not be compelled to 

use a higher mercury coal just because it happens to be near the 

plant. 

ii. Decision Regarding Whether to Create a Subcategory 

Based on Limestone Mercury Content. 

 EPA may create subcategories which distinguish among 

―classes, types, and sizes of sources.‖ CAA section 112 (d)(1). 

EPA reads this provision to provide the Agency with discretion 

to subcategorize, and EPA may exercise that discretion if 

sources are rationally distinguishable due to some difference in 

class, type or size. See Lignite Energy Council v. EPA, 198 F. 

3d 930, 933 (D.C. Cir. 1999) (―EPA is not required by law to 

subcategorize--section 111 [b] [2] merely states that  ̳the 

Administrator may distinguish among classes, types, and sizes 

within categories of new sources‘‖ (emphasis original)). 

Moreover, as we noted at proposal, ―normally, any basis for 

subcategorizing must be related to an effect on emissions, 

rather than to some difference among sources which does not 

affect emissions performance.‖ 74 FR at 21145. EPA may also 
Page 42 of 456

exercise this discretion on a pollutant-specific basis, since 

the difference in class, type or size may only have practical 

significance for certain HAP. In this final rule, EPA carefully 

considered the possibility of creating different subcategories 

of cement kilns with respect to mercury emissions. 

The subcategorization possibilities for mercury which we 

considered and rejected at rule proposal were the type of kiln, 

presence of an inline raw mill, practice of wasting cement kiln 

dust, total mercury inputs, or geographic location. See 74 FR 

21144-21145. We likewise reject these bases in this final rules 

for the reasons already stated. 

At proposal we also considered subcategorizing by the 

mercury concentration of the limestone in the kiln‘s proprietary 

quarry. We did not propose to create this type of subcategory, 

and also choose not to do so in this final rule. 

As we explained at proposal, the facts do not indicate 

sharp disparities in limestone mercury content that readily 

differentiate among types of sources for most of the facilities 

for which we have data, and thus do not support this

subcategorization approach for the majority of the facilities. 

See Figure 1 showing a gradual continuum of mercury 

concentrations in limestone for all but two outlying plants. 
Page 43 of 456

Figure 1. Average Mercury Concentration of Limestone

Industry commenters who supported creating a separate 

subcategory for the two highest mercury emitting sources based 

on limestone mercury content agreed with this assessment. Thus, 

EPA sees no technical justification to subcategorize by 

limestone quarry mercury content for the majority of the source 

category. 

However, as also shown in Figure 1, there is a sharp 

disparity for two kilns which have the highest quarry mercury 

contents. These sources‘ mercury emissions are also 

disproportionately higher than all other cement kilns‘, and are 

Average Mercury Content of Limestone

0.00

200.00

400.00

600.00

800.00

1000.00

1200.00

0 10 20 30 40 50 60 70 80 90 100

Kiln Number

Avg ppb Hg in Limestone
Page 44 of 456

related almost entirely to the limestone mercury content, not to 

mercury content of other inputs. Commenters who supported 

subcategorization by quarry mercury levels recommended that EPA 

create a separate source category for these two kilns based on 

their uniquely high quarry mercury contents. 

If we were to set a separate subcategory for these two 

kilns, we determined that the floor level of control would be 

approximately 2100 lb/MM tons clinker. Due to the high level of 

this floor, we evaluated a beyond-the-floor option of 85 percent 

reduction in emission for the highest emitting kiln. This level 

would represent the highest level of mercury control believed 

achievable for the highest emitting facility based on test data 

on a pilot mercury control system for that facility.16 This 

level of control would result in an emissions limit of 

approximately 500 lb/MM tons clinker. This level is over 10 

times the level that will be required for all other kilns, and 

even exceeds every other kiln‘s uncontrolled mercury emissions 

levels which range from 20 to 400 lb/MM tons clinker. 

Mercury in the air eventually settles into water or onto 

land where it can be washed into water. Once deposited, certain 

microorganisms can change it into methylmercury, a highly toxic 

form that builds up in fish, shellfish and animals that eat 

 

16 Letter, C. Lesslie, Ash Grove Cement to P. Tsirigotis, U.S. 

EPA, April 22, 2010.
Page 45 of 456

fish. Fish and shellfish are the main sources of methylmercury 

exposure to humans. Methylmercury builds up more in some types 

of fish and shellfish than in others. The levels of 

methylmercury in fish and shellfish depend on what they eat, how 

long they live and how high they are in the food chain. Mercury 

exposure at high levels can harm the brain, heart, kidneys, 

lungs, and immune system of people of all ages. Research shows 

that most people's fish consumption does not cause a health 

concern. However, it has been demonstrated that high levels of 

methylmercury in the bloodstream of unborn babies and young 

children may harm the developing nervous system, making the 

child less able to think and learn.17 Heightened concern for 

mercury‘s toxic effects is reflected directly in the structure 

of section 112 of the Act. Mercury is one of the pollutants 

identified for MACT-level control under the CAA‘s air toxics 

provision even (in most instances) when emitted by area sources 

(see CAA section 112(c)(6)).

Thus, creating a high-mercury subcategory for two kilns 

based on limestone mercury content would result in standards 

allowing emissions of 500 lb/MM tons of clinker. Based on 2008 

production rates, this would allow 1,020 pounds of mercury 

emissions per year from the potential two-plant subcategory. To 

 

17 For more information see http://www.epa.gov/mercury/about.htm
Page 46 of 456

put this in perspective, the rest of the industry (92 plants) 

would be allowed to emit 1,012 pounds tons of mercury per year 

(again based on 2008 production rates), and the two highemitting plants would be allowed to emit 1,020 pounds per year. 

This would result in a doubling of mercury emissions from this 

source category after the application of MACT. Moreover, 

national mercury emissions for industrial sources are 

approximately 50 tpy. That would mean that these two sources 

alone would constitute 1 percent of the industrial mercury 

emissions for the U.S. EPA believes it is a reasonable exercise 

of discretion not to create a subcategory, where, as here, doing 

so would allow on-going emissions of a disproportionately high 

volume of a high-toxicity pollutant.

Due to mercury‘s high toxicity and the extremely high 

mercury emissions that would result, the Administrator is not 

exercising her discretion to subcategorize in setting the final 

mercury emissions limit. In light of this decision, it is 

unnecessary for EPA to address the further question of whether 

subcategorizing by raw material content of proprietary quarries 

is permissible under section 112 of the Act. 

Although the Agency has concluded that it is reasonable to 

set the same mercury standard for all cement kilns, we 

acknowledge the unique challenges that the highest emitting 

sources may face in meeting the reductions within the regulatory 
Page 47 of 456

compliance timeline. Specifically, providing a mechanism to the 

two highest mercury-emitting plants to make significant 

reductions (i.e., 90 percent) in their mercury emissions before 

the three year compliance period could result in as much as two

tons of additional mercury reductions. EPA is interested in 

working with these two plants to consider mechanisms that could 

assure these early reductions.

iii. Beyond the Floor Determinations for Mercury.

We are basing the final mercury standard on the floor level 

of control. When we establish a beyond the floor standard we 

typically identify control techniques that have the ability to 

achieve an emissions limit more stringent than the MACT floor. 

Under these final amendments, most existing kilns would have to 

have installed both a wet scrubber and activated carbon 

injection (ACI) for control of mercury, HCl and THC.18 To 

achieve further reductions in mercury beyond what can be 

achieved using wet scrubber and ACI in combination, the 

available options would include closing the kiln and relocating 

to a limestone quarry having lower mercury concentrations in the 

limestone, transporting low-mercury limestone in from long 

distances, switching other raw materials to lower the amount of 

 

18 Summary of Environmental and Cost Impacts of Proposed 

Revisions to Portland Cement NESHAP (40 CFR Part 63, subpart 

LLL), April 15, 2009.
Page 48 of 456

limestone in the feed, wasting CKD, and installing additional 

add-on control devices. These options were discussed at 

proposal, and were rejected as either technically infeasible or 

not cost- effective. Consideration of non-air quality impacts 

and energy requirements do not change this conclusion. See 74 

FR at 22249-50. We received no comments that would cause us to 

change that determination. 

We did receive one comment from an environmental group

requesting EPA explore fuel switching as a beyond the floor 

option. However, EPA thoroughly explored fuel switching as a 

control option in the 2006 rulemaking and determined that there 

were problems with fuel availability and the costs were 

prohibitive. See 70 FR 72340. EPA is not presently aware of 

facts that would justify a different approach in this final 

rule.

As a result of these analyses, we determined that, 

considering the technical feasibility and costs, there is no 

reasonable beyond the floor control option, and the final 

mercury emission limit is based on the MACT floor level of 

control.

c. THC Limits for Kilns and Raw Material Dryers. 

The limits for existing and new sources in this final rule 

apply to both area and major sources. As noted earlier, we have 
Page 49 of 456

applied these limits to area sources consistent with CAA section 

112(c)(6). 

i. Floor Determination. EPA proposed THC emissions limits 

of 7 and 6 parts per million by volume dry (ppmvd) for existing 

and new sources respectively for both cement kilns and raw 

material dryers. The existing source standard was based on the 

performance of the best performing 12 percent of cement kilns 

for which we had THC CEMS data. At proposal we requested

comment on the issue of whether or not we should base the 

existing source floor on the best performing five kilns, rather 

than on the best performing 12 percent (two kilns). Industry 

commenters supported the use of the best five kilns stating that 

this would be in keeping with what appeared to be the intent of 

Congress that five kilns should be the minimum number of sources 

on which to set an existing source floor. However, other 

commenters noted that a plain reading of the statute is that 

when the source category has 30 or more sources, the top 

performing 12 percent for which the Administrator has data must 

be used, even if this results in less than five facilities due 

to lack of available data. In this final rule we are 

reaffirming our decision at proposal to use the best performing 

12 percent rather that the best performing five facilities 

because we believe this result to be unavoidably compelled by 

the literal language of the statute.
Page 50 of 456

At proposal we set the emissions limit based on the 99th

percentile of the available data. As a result of new data 

received after the comment period, we recalculated the averages 

of the kilns for which we had CEMS data and selected the best 

performing two kilns (12 percent of 15 total kilns) based on 

their average emissions. See Calculations of Floors for Final 

Portland Cement NESHAP dated August 6, 2010. Because these were 

large data sets (688 and 274 readings), we directly calculated 

the 99th percentile of the 30-day averages to determine the MACT 

floor which is 24 ppmvd.19 This is shown in Table 3.

Table 3. Summary of THC CEMS Data and MACT Floor

Kiln Average 

(ppmvd 

at 7% 

O2, 

propane)

Number 

of 

readings

Kiln type Inline 

raw 

mill

Kiln 1 4.7 668 Preheater/precalciner yes

Kiln 2 5.7 274 Precalciner yes

Existing 

Source 

Average 

5.2

Existing 

Source 99th

percentile 

24

New Source 

Average 

4.7

New Source 

99th

percentile 

24

 

19 In other words, as noted above, EPA possesses sufficient THC 

data that it is not necessary to estimate variability by use of 

the UPL equation. Rather, variability is calculated directly 

from the THC data set comprised of the two lowest emitting 

sources. 
Page 51 of 456

For new sources, we analyzed the data from the kiln with 

the lower numeric average to determine the 99th percentile of its 

performance. The result of this analysis was also a 24 ppmvd 

standard because this kiln had more variability (although a 

lower average performance) than the other kiln in the data set. 

This emission limit is based on a concentration measured dry, 

corrected to 7 percent oxygen and a 30-day average measured 

using a CEM. 

ii. Additional THC data received too late to be considered 

in this rulemaking. In addition to the THC CEMS data just 

discussed, we received another set of THC CEMS data from the 

Portland Cement Association (PCA). These data were not 

submitted to EPA until mid-June 2010, virtually too late for any 

consideration, much less considered analysis. This set 

consisted of THC CEMS data collected over periods ranging from 

31 to 90 days for additional kilns not in the data base 

discussed above, as well as additional data from some of the 

kilns already in our data base. These additional data increased 

the total number of kilns with THC CEMS data to 30 kilns. The 

PCA also provided a floor analysis on this data set and 

recommended THC emissions limits. The data set as presented by 

PCA is shown in Table 4.

Table 4. Portland Cement Association: Determination of 

Size of Best Performing Pool for Proposed Sub-Categories

for THC (mid-June 2010 data submission)
Page 52 of 456

Sub 

Category

Estimated 

US 

Population

Kilns for 

Which 

Data Are 

Available

Procedure for Selecting 

Pool of

Best Performing Kilns

Existing Units

New 

Rule Units Pool 

Size

Major NonCommingled 

Kilns

> 30 17 Best 12% 3

Best 

1

Major 

Commingled 

Kilns

< 30 7 Best 5 5

Best 

1

Area Kilns < 30 6 Work Practices Standard

In this analysis, the PCA proposed two subcategories: kilns 

where the coal preparation mill exhaust is comingled with the 

kiln exhaust, and kilns where the coal preparation mill has a 

separate stack. The PCA maintains that subcategories are needed 

because emissions for the coal preparation mill (which are 

believed to be chiefly methane from the coal) will, all other 

things being equal, elevate the THC emissions of the kiln 

exhaust. See also 74 FR at 21152. The PCA recommended floors 

are shown in Tables 5 and 6 below:

Table 5. Alternative MACT Floors 

for THC

Major Non-Commingled Kilns

Existing 

Units New Units

99th 

Percentile 30 ppm 11 ppm

99.9th

Percentile 36 ppm 12 ppm
Page 53 of 456

Table 6. Alternative MACT Floors 

for THC

Major Commingled Kilns

Existing 

Units New Units

99th 

Percentile 70 ppm 17 ppm

99.9th

Percentile 80 ppm 20 ppm

However, the PCA MACT analysis suffers from one major deficiency 

because it excludes area sources from the MACT floor analysis, 

and assumes a work practice for these sources. As previously 

noted, THC emissions serve as surrogates for POM and PCB 

emissions. CAA section 112(c)(6) requires EPA to list, and to 

regulate under standards established pursuant to CAA section 

112(d)(2) or (d)(4), categories of sources accounting for not 

less than 90 percent of emissions of these HAP standards 

established under CAA section 112(d)(2) must reflect the 

performance of MACT. Again, as explained above, EPA has long 

since determined that area source cement kilns‘ THC emissions 

must be controlled under CAA section 112 (d)(2) or (d)(4) in 

order to satisfy the 90 percent requirement. Therefore, these 

area sources should have been included in the MACT floor 

analysis.

If this error in the floor analysis is corrected, the MACT 

floor for the kilns with comingled exhaust would be unchanged 

from the PCA analysis of 70 ppmvd for existing and 17 ppmvd for 

new (assuming the statistical calculations were done correctly). 
Page 54 of 456

However, this estimate is premised on the assumption that 

there are less than 30 kilns in this subcategory (so that 5 

sources would be used to establish the floor). That assumption 

is based on data provided in the PCA report that indicated, of 

the 87 kilns that provided data to PCA on their coal preparation 

stack configurations, 13 had comingled exhaust. If there are 

actually 30 or more kilns with this configuration, the MACT 

floor would have to be based on the best performing 12 percent 

of 8 kilns (the 7 major source comingled kilns plus one area 

source comingled kiln) which would be one kiln, Lehigh at Union 

Bridge. If one kiln is used for the existing source floor, the 

existing source MACT limit would be 17 ppmvd using the 99th

percentile. The estimate of 26 versus 30 or more sources causes 

a high level of uncertainty in this analysis.

For sources that do not comingle the exhaust, the floor 

would appear to be approximately 13 ppmvd when the area sources 

are included in the analysis. This is also lower than the floor 

calculated from the long term data set out above (and would 

result in a standard roughly 50 percent more stringent than that 

which EPA is adopting).

The PCA analysis also recommended a separate subcategory 

for kilns with high limestone outgassing based on the 

information shown below:
Page 55 of 456

0

10

20

30

40

50

60

70

80

90

100

0 2 5 50 75 100 125 150 175 200 225

Stack Emissins (ppm THC, dry &% O2 )

Limestone Outgassing (mg THC/kg)

Low THC Limestone High THC Limestone

High Limestone Subcategory

The limestone outgassing factor is determined by heating a 

sample of the limestone from the kiln‘s proprietary quarry to 

determine the potential for THC emissions based on the amount 

and types of organic materials present. The premise here is 

basically the same as previously discussed for subcategorization 

by limestone mercury content when setting mercury emissions 

limits, because the kiln is tied to its limestone quarry. The 

subcategory proposed was for sources with THC outgassing ≥ 65 

mg/kg. The recommended THC emissions limits for this 

subcategory were 170 and 62 ppmvd for new and existing sources 

respectively. This analysis, however, suffers from the same 

defect previously discussed in that for a subcategory with only 

three sources where we have data, the best performing 12 percent 

would be one kiln, so the actual limit for new and existing 
Page 56 of 456

would be 62 ppmvd. We rejected this option because it suffers 

from the same defects as subcategorization by limestone mercury 

content. First, the choice of high versus low organics appears 

arbitrary. A level between 75 and 175 could just as easily have 

been chosen. The selection of 65 appears to be an attempt to 

move the high THC emitting facility into a subcategory with a 

high limit. Second, subcategorizing in this manner could result 

in situations where a few facilities would be allowed to emit at 

levels well above the remainder of the sources in this source 

category. Third, although the two kilns with the highest 

outgassing limestone appear to be outliers (similar to the two 

facilities with unusually high limestone mercury contents), we 

do not have data on a majority of the kilns (as we do with 

mercury) and it is possible that if we had more data, the two 

facilities that appear to be outliers would be part of a gradual 

continuum, which would mean the level we chose to separate high 

and low outgassing limestone would be mistaken.

We also considered combining all the THC CEMS data (the 

more recent PCA data, data used at proposal, and data received 

during the comment period which would create a data set of 34 

kilns). The results of this analysis was a floor (based on the 

99th percentile of the data) of 24 ppmvd for existing sources 

(the same standard adopted in the final rule) and 3 ppmvd for 

new sources (more stringent than the new source standard in the 
Page 57 of 456

final rule). Given the short time available to review the PCA 

data, the uncertainty concerning the actual size of one of the 

subcategories, the fact that these data would not in our view 

significantly change the levels of the standard for most kilns, 

and the concerns we have with subcategorization by limestone 

organic outgassing potential, we conclude that there is no 

compelling reason to change our floor determination based on 

this new information, which again was submitted only days before 

the final rule requirements had to be determined in order to 

meet the court ordered deadline for this rule. 

iii. Beyond the floor determination. At proposal we 

evaluated several practices and technologies that are available 

to cement kilns to control emissions of organic HAP at a level 

beyond the floor. 74 FR at 21152. These practices include raw 

materials substitution, ACI systems and limestone scrubber and 

regenerative thermal oxidizer (RTO). We rejected each of these 

alternatives based on technical limitations or poor costeffectiveness. Consideration of non-air quality impacts and 

energy support this determination as well (RTO‘s in particular 

being associated with appreciable energy penalties). 74 FR at 

21152. We received no comments that have caused us to change 

that proposed decision. Therefore, we are choosing the floor 

level of control for the final THC emissions limit. 
Page 58 of 456

iv. Standards for THC. We are establishing the emissions 

limit for THC at the floor level of control. In addition, 

because the final existing source standard will be more 

stringent than the new source standard of 50 ppmvd for 

greenfield new sources contained in the 1999 final rule, we are 

also removing the 50 ppmvd standard for both kilns and raw 

material dryers.

EPA proposed an alternative floor for non-dioxin organic 

HAP, based on measuring the organic HAP itself rather than the 

THC surrogate. This equivalent alternative limit would provide 

additional flexibility in determining compliance, and it would 

be appropriate for those cases in which methane and ethane 

comprise a disproportionately high amount of the organic 

compounds in the feed because these non-HAP compounds could be 

emitted and would be measured as THC. At proposal we determined 

that organic HAP averaged 24 percent of the THC. Since proposal 

we have reevaluated these data and recalculated an average 

organic HAP concentration of 35 percent. Based on this 

percentage, and the fact that the THC emission limit is now 24 

ppmvd, we are promulgating an alternative organic HAP limit of 9 

ppmvd, corrected to 7 percent oxygen (or 19 percent oxygen for 

raw material dryers), for new and existing sources. The 

specific organic compounds that will be measured to determine 

compliance with the alternative to the THC limit are benzene, 
Page 59 of 456

toluene, styrene, xylene (ortho-, meta-, and para-), 

acetaldehyde, formaldehyde, and naphthalene. These were the 

organic HAP species that were measured along with THC in the 

cement kiln emissions tests that were reviewed. Nearly all of 

these organic HAP species also were identified in an earlier 

analysis of the organic HAP concentrations in THC in which the 

average concentration of organic HAP in THC was 35 percent.20

The alternative standard will be based on organic HAP 

average concentration of organic HAP in THC was 35 percent.21

The alternative standard will be based on organic HAP emission 

testing and concurrent THC CEMS measurements that will establish 

a site specific THC limit that will demonstrate compliance with 

the total organic HAP limit. The site specific THC limit will 

be measured as a 30 day rolling average. 

iv. THC Emissions from Raw Material Dryers. As we noted 

at proposal, some plants may dry their raw materials in separate 

dryers prior to or during grinding. See 74 FR at 21153; see 

also 63 FR at 14204. This drying process can potentially lead to 

organic HAP and THC emissions in a manner analogous to the 

release of organic HAP and THC emissions from kilns when hot 

kiln gas contacts incoming feed materials. The methods 

available for reducing THC emissions (and organic HAP) is the 

 

20 Summary of Organic HAP Test Data. August 6, 2010

21 Ibid.
Page 60 of 456

same technology described for reducing THC emissions from kilns 

and in-line kiln/raw mills. Based on the similarity of the 

emissions source and controls, we proposed to set the THC 

emissions limit of materials dryers at the same levels as the 

kilns.

Commenters noted that stand alone raw materials dryers have 

higher gas flows relative to the amounts of fuels burned. This 

results in higher oxygen concentrations, typically as high as 19 

percent. They also noted that raw material dryers may have 

higher THC and lower HAP emissions because raw materials dryers 

operate at lower temperature than kilns (since the dryer only 

needs to operate at the temperature needed to remove free 

water), and that the residence times for dryers is considerably 

longer than for kilns. 

However, although we agree that the exhaust oxygen 

contents of raw material dryers may be higher than occurs with a 

cement kiln, there are reasons to believe that dryers actually 

emit less hydrocarbons than kilns. Operating at lower 

temperatures, we would expect any hydrocarbons that are emitted 

from dryers to be only those with the highest volatility, and 

therefore that the potential for emissions of organic HAP would 

be less for dryers than for kilns. However, the longer 

residence times could tend to increase emissions. Therefore, 

making any conclusions on the emission of dryers relative to 
Page 61 of 456

kilns is difficult. We also note that we are allowing dryers to 

also use the alternative organic HAP emissions limit, so if the 

surmise that organic HAP emissions are low relative to the 

cement kilns is correct, this alternative should be very viable 

for these sources. 

In short, we received no data indicating that the same 

limit as for kilns was infeasible, or that would otherwise allow 

us to set a different THC emissions limit for raw materials 

dryers. Therefore, in these final amendments we are setting the 

THC emissions limit at the same level as the cement kiln‘s, 

which is 24 ppmvd measured as propane.

However, because raw material dryers have high oxygen 

contents due to their inherent operation characteristics (and 

not due to the addition of dilution air), referencing the raw 

material dryer standard to 7 percent oxygen would actually 

result in a more stringent standard than for cement kilns. For 

example, given the typical oxygen contents of kiln exhaust (7 to 

12 percent), a kiln just meeting the THC limit of 24 ppmvd would 

have an actual stack measurement of approximately 16 to 24 

ppmvd. If the raw material dryer standard is referenced to the 

same oxygen level, they would have to meet a measured THC limit 

of approximately 3 ppmvd. For this reason, we are referencing 

the oxygen level of the standard for raw materials dryers to 19 
Page 62 of 456

percent oxygen, which is the typical oxygen level found in the 

exhaust of these devices. 

d. Hydrochloric Acid Emissions from Kilns. 

In the proposed rule we based the proposed HCl emission 

limit for major sources on HCl data measured at 27 kilns using 

Method 321. The data in ppmvd corrected to 7 percent oxygen (O2) 

were ranked by emissions level and the top 12 percent (4 kilns) 

lowest emitting kilns identified as best performing existing 

sources. The calculated MACT floors were 2 ppmvd and 0.1 ppmvd 

respectively.

i. Floor Determination. Subsequent to proposal, we 

received comments that indicated we had inappropriately (albeit 

inadvertently) included certain natural area sources in the MACT 

floor analysis. We have removed those natural area sources from 

the floor analysis. In addition, many of the source tests were 

not actually EPA Method 321 tests; others lacked important 

quality assurance information. As a result, we issued letters 

under CAA section 114 authority requiring facilities that were 

major sources and that had previously submitted data to retest 

their facilities. We used this new data set to calculate a MACT 

floor. The data from the best performing three sources, as 

determined by average emissions during the test, are shown below 

in Table 7.

Table 7. HCl MACT Floor
Page 63 of 456

Kiln HCl Emissions (ppmvd at 7% O2)

1 0.34

2 0.44

3 0.46

MACT – Existing

Average (Top 3) 0.41

Variance 0.02

UPL 0.52

MACT – New

Average 0.34

Variance 0.0

UPL 0.34

However, these measurements are very close to the detection 

limit for analytic method 321 actually calculated in the field 

for HCl -- from 0.2 to 0.3 parts per million by volume (ppmv) as 

measured in the stack.22 The expected measurement imprecision 

for an emissions value occurring at or near the method detection 

level is in fact about 40 to 50 percent. This large measure of 

analytic uncertainty decreases as measured values increase: 

pollutant measurement imprecision decreases to a consistent 

relative 10 to 15 percent for values measured at a level about 

three times the method detection level. See American Society of 

Mechanical Engineers, Reference Method Accuracy and Precision 

(ReMAP): Phase 1, Precision of Manual Stack Emission 

Measurements, CRTD Vol. 60, February 2001. Thus, if the value 

equal to three times the representative method detection level 

 

22 Memorandum. EPA Method 321 Detection Limits and Minimum 

Quantification Limit, July 26, 2010
Page 64 of 456

were greater than the calculated floor emissions limit, we would 

conclude that the calculated floor emissions limit does not 

account entirely for measurement variability. 

That is the case here with HCl. The calculated standard 

(not accounting for the inherent analytical variability in the 

measurements) is 0.52 ppm (see Table 8 above). In order to 

account for measurement variability, we multiplied the highest 

reported minimum detection level for the analytic method by a 

factor of three which results in a level of 0.9 ppmv. This 

represents the lowest level that can be reliably measured using 

this test method, and we therefore believe that it is the lowest 

level we can set as the MACT limit taking the appropriate 

measurement variability into account. Converting this level to 

a dry basis at 7 percent oxygen results in a floor of 3 ppmvd 

for both new and existing sources. As explained further below, 

we are using a CEM to measure this standard, and it is a 30-day 

average.

ii. Beyond the Floor Determination. At proposal we 

examined the use of a packed bed scrubber, which was assumed to 

have a higher HCl removal efficiency than the spray tower 

limestone scrubbers typically used in this industry. 

Considering the high costs, high cost-effectiveness and small 

additional emissions reduction (and adverse cross-media 

impacts), we did not believe that a beyond-the-floor standard 
Page 65 of 456

for HCl is justified. We received no comment that would change 

that decision. In addition, the current HCl floor limit is

actually set at the lowest level we believe can be accurately 

quantified by the applicable test method. Therefore, a lower 

standard could not be reliably quantified. For these reasons we 

selected the floor level of control as MACT for HCl for major 

sources. 

iii. Compliance Mechanisms. As proposed, kilns equipped 

with wet scrubbers may demonstrate compliance by means of stack 

testing at intervals of five years, plus utilize continuous 

monitoring of specified parameters. All other kilns are 

required to use a CEMS, with compliance based on a 30-day 

rolling average. Although the underlying data were obtained via 

stack tests, rather than with continuous monitors, EPA believes 

that because the HCl standard is established at a level higher 

than all measured values (to account for the inability to 

reliably measure any lower standard) and measured based on 30-

day averages, it provides an ample compliance margin.

iv. Determination not to Establish a Risk-Based Standard 

for HCl. At proposal, EPA elected not to exercise its 

discretion under CAA section 112(d)(4) and proposed a major 

source standard for HCl based on MACT. The primary basis for 

not setting a health-based standard was that setting a MACT 

standard for HCl not only controlled HCl but also co-controlled 
Page 66 of 456

other HAP (such as HF, Chlorine (Cl2), and hydrogen cyanide 

(HCN)) and criteria pollutants yielding very substantial 

environmental benefits. However, we also requested comment on 

whether we had the legal authority to establish a standard for 

HCl, and, if so, whether we should exercise our discretion to do 

so. 74 FR at 21154. After considering comments, EPA has 

decided not to exercise its discretion to establish a risk-based 

standard for HCl under CAA section 112(d)(4), opting instead to 

promulgate a standard for HCl based on the performance of MACT 

in this final rule. This section discusses the basis for that 

decision.

 Setting technology-based MACT standards for HCl will 

result in significant reductions in emissions of other 

pollutants, most notably SO2, and would likely also result in 

additional reductions in emissions of mercury, along with 

condensable PM, ammonia, and semi-volatile compounds. The 

additional reductions of SO2 alone attributable to the MACT 

standard for HCl are estimated to be 124,000 tons per year in 

the third year following promulgation of the proposed HCl 

standard. These are substantial reductions with substantial 

public health benefits. SO2 emissions are associated with a 

variety of human health, ecosystem, and visibility effects. 75 

FR at 35525-27 (June 22, 2010). Even more significantly, SO2 is 

also a precursor to PM2.5. Reducing SO2 emissions also reduces 
Page 67 of 456

PM2.5 formation, human exposure, and the incidence of PM2.5-

related health effects, among them premature mortality and 

cardiovascular and respiratory morbidity. See detailed 

discussion of PM2.5 health effects in the text at Table 13 below. 

For these rules the SO2 reductions represent a large 

fraction of the total monetized benefits from reducing PM2.5, but 

it is not possible to isolate the portion if the total monetized 

benefits attributable to the emission reductions of SO2 resulting 

from the application of HCl controls. The benefits models 

assume that all fine particles, regardless of their chemical 

composition, are equally potent in causing premature mortality 

because there is no clear scientific evidence that would support 

the development of differential effects estimates by particle 

type.

We estimate the number of premature mortalities avoided 

each year due to the reductions in PM2.5 exposure attributable to 

this standard to be in the thousands. RIA Table 6-3. We also 

estimate there to be over 2800 instances of annual

cardiovascular and respiratory morbidity cases avoided, and 

hundreds of thousands of work loss days avoided. Id. The 

monetized benefits just from premature mortality avoided 

attributable to PM2.5 reductions from this standard are estimated 

to be $7.4 billion to $18 billion at the three percent discount 

rate and $6.7 billion to $17 billion at a seven percent discount 
Page 68 of 456

rate, nearly an order of magnitude higher than the rule‘s 

estimated social costs. See Table 13 below. Although MACT 

standards may directly regulate only HAPs and not criteria 

pollutants, Congress did recognize, in the legislative history 

to section 112(d)(4), that MACT standards would have the 

collateral benefit of controlling criteria pollutants as well 

and viewed this as an important benefit of the air toxics 

program.23 The EPA believes these health and environmental 

benefits to be large and important and fully in keeping with the 

paramount goal of the Clean Air Act ―to protect and enhance the 

quality of the Nation‘s air‖ (CAA section 101 (b)(1)), and so is 

adopting MACT standards for HCl.24

Commenters from industry urged EPA to retain a risk-based 

standard but did not challenge EPA‘s finding or quantification 

that there would be these enormous health and environmental 

benefits to setting a standard reflecting MACT to control HCl. 

 

23 See S. Rep. No. 101-228, 101st Cong. 1st sess. at 172. EPA 

consequently does not accept the argument that it cannot 

consider reductions of criteria pollutants in determining 

whether to exercise its discretion to adopt a risk-based 

standard under section 112 (d)(4). There appears to be no valid 

reason that EPA must ignore controls which further the health 

and environmental outcomes at which section 112 (d) of the Act 

is fundamentally aimed.

24 We further note that HCl is not the only acid gas HAP emitted 

by Portland cement plants. Hydrogen fluoride, HCN, ammonia, and 

chlorine may also present and were not accounted for in the risk 

analysis. Setting an HCl standard under 112(d)(2)and (3) allows 

the Agency to also address these other HAPs as they are cocontrolled by wet scrubbers along with HCl. 
Page 69 of 456

The commenters nonetheless urged EPA to retain a risk-based 

standard, noting that EPA had done so in the predecessor to this 

rule and for other source categories, and that HCl is a 

threshold pollutant within the meaning of CAA section 112(d)(4) 

so that there is a technical basis for such a standard. These

arguments do not persuade the Agency to forego the very 

significant benefits just outlined. However, even if (contrary 

to the analysis just set out) EPA were inclined to adopt a riskbased standard here, there would be technical obstacles to doing 

so, as described at the final part of this section.

As we noted in the proposed rule, as a general matter, CAA 

section 112(d) requires MACT standards at least as stringent as 

the MACT floor to be set for all HAP emitted from major sources. 

However, CAA section 112(d)(4) provides that for HAP with 

established health thresholds, EPA has the discretionary 

authority to consider such health thresholds with an ample 

margin of safety when establishing emission standards under CAA 

section 112(d). This provision is intended to allow EPA to 

establish emission standards other than technology-based MACT 

standards in cases where a less stringent emission standard will 

still ensure that the health threshold will not be exceeded, 

with an ample margin of safety. In order to exercise this 

discretion, EPA must first conclude that the HAP at issue has an 

established health threshold and must then provide for an ample 
Page 70 of 456

margin of safety when considering the health threshold to set an 

emission standard. We discussed this issue at length in the 

recent proposed Industrial Boiler MACT. See 75 FR at 32020-33 

(June 4, 2010) (declining to propose a risk-based standard for 

HCl emissions). 

The legislative history of section 112(d)(4) indicates that 

Congress did not intend for this provision to provide a 

mechanism for EPA to delay issuance of emission standards for 

sources of HAPs. The legislative history also indicates that a 

health-based emission limit under section 112(d)(4) should be 

set at the level at which no observable effects occur, with an 

ample margin of safety. S. Rep. 101-228 at 171-72. The 

legislative history further states that employing a section 

112(d)(4) standard rather than a conventional MACT standard 

―shall not result in adverse environmental effects which would 

otherwise be reduced or eliminated.‖ Id. 

It is clear that EPA may exercise its discretionary 

authority under 112(d)(4) only with respect to pollutants with 

an established health threshold. Where there is an established 

threshold, EPA has, in the proposed rule on industrial boilers, 

interpreted section 112(d)(4) to allow us to weigh additional 

factors, beyond any established health threshold, in making a 

judgment whether to set a standard for a specific pollutant 

based on the threshold, or instead follow the traditional path 
Page 71 of 456

of developing a MACT standard after determining a MACT floor (75 

FR 32030). In deciding whether to exercise its discretion for a 

threshold pollutant for a given source category, EPA has 

interpreted section 112(d)(4) to allow us to take into account 

factors such as the following: the potential for cumulative 

adverse health effects due to concurrent exposure to other HAPs 

with similar biological endpoints, from either the same or other 

source categories, where the concentration of the threshold 

pollutant emitted from the given source category is below the 

threshold; the potential impacts on ecosystems of releases of 

the pollutant; and reductions in criteria pollutant emissions 

and other co-benefits that would be achieved via the MACT 

standard – the decisive factor here. Each of these factors is 

directly relevant to the health and environmental outcomes at 

which section 112 of the Clean Air Act is fundamentally aimed. 

If EPA does determine that it is appropriate to set a standard 

based on a health threshold, we must develop emission standards 

that will ensure the public will not be exposed to levels of the 

pertinent HAP in excess of the health threshold, with an ample 

margin of safety.

Since any emission standard under section 112(d)(4) must 

consider the established health threshold level, with an ample 

margin of safety, in this rulemaking EPA has considered the 

adverse health effects of the HAP acid gases, beginning with 
Page 72 of 456

HCl. Research indicates that HCl is associated with chronic 

respiratory toxicity. In the case of HCl, this means that 

chronic inhalation of HCl can cause tissue damage in humans. 

Among other things, it is corrosive to mucous membranes and can 

cause damage to eyes, nose, throat, and the upper respiratory 

tract as well as pulmonary edema, bronchitis, gastritis, and 

dermatitis. Considering this respiratory toxicity, EPA has 

established a chronic reference concentration (RfC) for the 

inhalation of HCl of 20 μg/m3. (See 

http://www.epa.gov/ncea/iris/subst/0396.htm.) An RfC is defined 

as an estimate (with uncertainty spanning perhaps an order of 

magnitude) of a continuous inhalation exposure to the human 

population (including sensitive subgroups25) that is likely to be 

without an appreciable risk of deleterious effects during a 

lifetime. The IRIS health assessment evaluated chronic noncancer risks and did not include an evaluation of carcinogenic 

effects (on which there are very limited studies). As a 

reference value for a single pollutant, RfCs do not reflect any 

potential cumulative or synergistic effects of an individual‘s 

exposure to multiple HAPs or to a combination of HAPs and 

criteria pollutants. Similarly, an RfC evaluation does not focus 

on potential environmental impacts.

 

25 ―Sensitive subgroups‖ may refer to particular life stages, 

such as children or the elderly, or to those with particular 

medical conditions, such as asthmatics.
Page 73 of 456

With respect to the potential health effects of HCl, we 

know the following:

1. Chronic exposure to concentrations at or below the RfC 

is not expected to cause chronic respiratory effects; 

2. Little research has been conducted on its 

carcinogenicity. The one occupational study of which 

we are aware found no evidence of carcinogenicity;

3. There is a significant body of scientific literature 

addressing the health effects of acute exposure to HCl 

(California Office of Health Hazard Assessment, 2008. 

Acute Toxicity Summary for Hydrogen Chloride, 

http://www.oehha.ca.gov/air/hot_spots/2008/AppendixD2_

final.pdf#page=112 EPA, 2001). However, we currently 

lack information on the peak short-term emissions of 

HCl from cement kilns which might allow us to 

determine whether a chronic health-based emission 

standard for HCl would ensure that acute exposures 

will not pose health concerns. 

4. We are aware of no studies explicitly addressing the 

toxicity of mixtures of HCl with other respiratory 

irritants. However, many of the other HAPs (and 

criteria pollutants) emitted by cement kilns also are 

respiratory irritants, and in the absence of 

information on interactions, EPA assumes an additive 
Page 74 of 456

cumulative effect (Supplementary Guidance for 

Conducting Health Risk Assessment of Chemical 

Mixtures. 

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=20

533). 

Cement kilns also emit other acid gases along with HCl, 

including chlorine (Cl2), HCN and hydrogen fluoride (HF), 

all of which are HAPs. Like HCl, these HAP gases have 

established chronic health thresholds below which they 

are not expected to pose any significant risk of chronic 

respiratory effects, have no evidence to suggest that 

they may pose carcinogenic effects, and have an 

established body of literature regarding acute 

respiratory health effects. They are also controlled 

during the process of controlling HCl emissions from 

cement kilns using a wet scrubber. As such, their health 

impacts must be taken into account when considering a 

health-based emission limit for HCl.

In the 2006 final rule, EPA did not set any standard for 

HCl.26 The Agency reasoned that no further control was necessary 

 

26 Although the decision not to set a standard in 2006 was based 

on the authority of section 112(d)(4), we note that the statute 

in fact states: ―the Administrator may consider such threshold 

level, with an ample margin of safety, when establishing 

emission standards under this subsection.‖ Section 112(d)(4), 

emphasis added.
Page 75 of 456

for Portland cement emissions of HCl because HCl is a ―health 

threshold pollutant‖ and human health is protected with an ample 

margin of safety at current HCl emission levels. 71 FR at 

76527. Underlying this conclusion was EPA‘s analysis of a 

tiered screening study of dispersion modeling of cement 

facilities‘ worst-case and actual HCl emissions. This study was 

conducted by the Portland Cement Association for about twothirds of operating U.S. cement plants. Dispersion modeling 

results were evaluated against the RfC for HCl.27 The screening 

analysis involved making conservative assumptions regarding HCl 

emission concentrations and plants‘ operating conditions 

(greater concentrations than known to be emitted and perpetual

operation at maximum capacity). All plants in the analysis, 

with five exceptions, had HCl levels well below a Hazard 

Quotient (HQ) level of 1.0, the ratio of exposure (or modeled 

concentration) to the health reference value or threshold level. 

The remaining five plants in the analysis had HQ levels greater 

than 1.0 assuming maximum emissions, but less than 1.0 when 

their actual emissions were used in the dispersion models. Id.

at 76528-29. 

 

27 In the previous study EPA also evaluated dispersion modeling 

results against an acute exposure guideline level (AEGL) below 

which acute effects would not be expected to occur. However, 

even given the uncertainties mentioned for short term HCl 

emissions, that analysis indicated that chronic effects would be 

of the most concern.
Page 76 of 456

At proposal of these amendments, recognizing that the 2006 

determination was deficient, if for no other reason because it 

failed to establish any emission standard whatever, EPA 

conducted its own analysis to determine what numerical standard 

for HCl would be necessary to at least assure that, for the 

sources in the controlled category or subcategory, persons 

exposed to emissions of HCl would not experience the adverse 

health effects on which the threshold is based. In order to 

determine this level, in the proposed rule we conducted a risk 

analysis of the same 68 facilities analyzed by PCA using a 

screening level dispersion model (AERSCREEN). Using the site 

specific stack parameters provided by the PCA and conservative

meteorological conditions (taken from the PCA analysis), the 

AERSCREEN modeling predicted the highest long term ground level 

concentration surrounding each facility, and used this 

concentration to back calculate the highest allowable HCl 

emissions rate that could occur without exceeding the allowable 

RfC. The results of this analysis indicated that an HCl 

emission limit of 23 ppmv or less (an order of magnitude higher 

than the MACT standard) would result in no exceedances of the 

RfC for HCl for any of the facilities assessed.28 

 

28 Derivation of a Health-Based Stack Gas Concentration Limit for 

HCl in Support of the National Emission Standards for Hazardous 

Air Pollutants from the Portland Cement Manufacturing Industry, 

April 10, 2009.
Page 77 of 456

Based on further consideration, EPA now believes that the 

2006 PCA study and analysis has the following deficiencies. 

First of all, not all cement plants were evaluated (the PCA 

study covered about two thirds of the plants in the source 

category), and among those not evaluated were cement plants with 

the most likelihood of posing risk at ground level from HCl 

emissions due to use of positive pressure baghouses with 

monovents or multiple short stacks. Secondly, the analysis did 

not consider the impacts of the co-emitted acid gases, an 

important consideration in determining an ample margin of 

safety. In addition, no data were provided, nor do we have 

data, on other pollutants in the vicinity of these cement 

facilities, or background concentration data for HCl to 

determine cumulative impacts of HCl emissions for these 

facilities.29 EPA‘s analysis of 2009 could not improve on the 

PCA study, given the lack of robust emissions data for Cl2, HF, 

and HCN, and the lack of any additional data for the cement 

kilns not included in the original study. As a result, EPA 

cannot ensure that the resulting derivation of 23 ppmv as a 

 

29 It should be noted that large amounts of site-specific 

information both on kiln operation and local meteorological 

information is needed to obtain meaningful results from 

AERSCREEN and other dispersion models. This information is in 

the ready possession of the industrial sources themselves, but 

for unknown reasons, was not provided by industry to EPA either 

as part of the 2006 PCA analysis or in response to subsequent 

data solicitations by EPA.
Page 78 of 456

possible health-based emission standard for HCl would result in 

chronic ambient levels of acid gases that would not pose 

significant health risks. EPA has no data that would allow us 

to extend that analysis to cover all acid gases and all 

facilities.

In addition to potential health impacts, EPA has evaluated 

the potential for environmental impacts when considering whether 

to exercise discretion under section 112(d)(4). When HCl gas 

encounters water in the atmosphere, it forms an acidic solution 

of HCl. In areas where the deposition of acids derived from 

emissions of sulfur and nitrogen oxides are causing aquatic 

and/or terrestrial acidification, with accompanying ecological 

impacts, the deposition of HCl could exacerbate these impacts. 

Being mindful of the explicit legislative history, and in 

keeping with past EPA practice, it is appropriate to consider 

potential adverse environmental effects in addition to adverse 

health effects when setting an emission standard for HCl under 

section 112(d)(4). The co-emissions of HF, HCN, and Cl2 from 

cement kilns could serve to further aggravate these 

environmental acidification impacts, but EPA has no data to 

determine these impacts.

Although the PCA analysis did not include an assessment of 

potential environmental effects, for the 2006 final Portland 

cement rule, EPA conducted its own analysis of potential effects 
Page 79 of 456

of cement kilns‘ HCl emissions to wildlife, aquatic life, and 

other natural resources. The Agency concluded at the time that 

acute and chronic exposures to expected HCl concentration around 

cement kilns are not expected to result in adverse environmental 

toxicity effects. Id. at 76529. EPA accordingly declined to 

establish any standard for HCl.

At this time, we now believe the ecological risk analysis 

performed in 2006 is insufficient, as it was merely a literature 

review and not a formal ecological assessment, and, as discussed 

in the previous paragraphs, it did not cover the impacts of the 

other acid gases, nor did it cover about one third of the 

existing cement plants. No additional information was provided 

during the comment period which addressed these various 

technical issues, notwithstanding EPA‘s solicitation of data.

Consequently, although EPA is declining to adopt a section 

112(d)(4) risk-based standard for HCl emissions from Portland 

cement facilities for the sound policy reasons discussed herein, 

we further note that there remain technical issues as to the 

appropriateness of such a standard even if EPA were inclined to 

exercise that discretion. We also do not view ourselves as 

bound by the technical determinations made in the 2006 

rulemaking for the reasons just explained.

EPA also has concluded that the facts here are 

distinguishable from those in other rulemakings in which it 
Page 80 of 456

exercised its discretionary authority under section 112 (d)(4). 

In the case of the Pulp and Paper MACT (63 FR at 18765 (April 

15, 1998)), the risk analysis indicated, at the 95 percent 

confidence interval, that the maximum concentration predicted to 

which people were estimated to be exposed was 0.3 g/m3, 60 times 

less than the inhalation reference concentration. This is a 

much lower value than present in the Portland cement risk 

analysis discussed above. In the case of the Lime Manufacturing 

NESHAP (67 FR at 78054 (Dec. 20, 2002)), there are two key 

distinctions. First, the technical information available to EPA 

covered 100 percent of all lime kilns in the U.S., which is not 

the case for the Portland cement risk analysis. Second, EPA did 

a worst case analysis as a supplement to the industry analysis 

and determined that the highest hazard index under that scenario 

was 0.21. Based on the EPA analysis determining a health based 

limit for Portland cement, if we were allow the same level of 

risk as we determined in Lime NESHAP analysis, the health based 

emission limit would be 2 ppmvd, which is almost the same level 

as the MACT standard we are finalizing in this action. 

EPA also considers the alternative standard for total 

chlorine in the Hazardous Waste Combustor MACT (70 FR at 59555 

(Oct. 12, 2005)) to be distinguishable. That rule, under the 

authority of section 112 (d)(4) establishes a site-specific 

risk-based standard for total chlorine (of which HCl is the 
Page 81 of 456

largest component), whereby, in lieu of meeting the MACT 

standard, sources may emit total chlorine at higher levels if 

they demonstrate that their emissions of total chlorine from all 

hazardous waste combustor sources at a facility do not exceed 

both acute (one-hour) and chronic (annual) exposure thresholds.

The demonstration must account for all relevant site-specific 

conditions, or be based on worst-case screening assumptions. If 

sources satisfy these criteria, the amount of their total 

chlorine emissions is still capped by the technology-based limit 

to which these sources were previously subject. The sitespecific demonstrations, applicability to all combustor sources 

at a facility, use of acute and chronic health benchmarks, and 

capping of emission limits are all unique to that rule.

e. PM Emissions from Kilns 

Particulate matter serves as a surrogate for non-volatile 

metal HAP (a determination upheld for this source category in 

National Lime Ass‘n, 233 F. 3d at 637-39). Existing and new 

major sources are presently subject to a PM limit of 0.3 lb/ton 

of feed which is equivalent to 0.5 lb/ton clinker. EPA is 

amending this standard for major sources, and also adding PM 

standards for existing and new area source cement kilns. In all 

instances, EPA is revising these limits because they do not 

represent MACT, but rather a level which is achievable by the 

bulk of the industry. See 63 FR at 14198 (March 24, 1998); see 
Page 82 of 456

also 233 F. 3d at 633 (indicating that the standards for PM were 

likely legally deficient but that the argument had not been 

properly preserved for the court to adjudicate). This is not 

legally permissible. Brick MACT, 479 F. 3d at 880-81. EPA thus 

does not accept the argument of some commenters that EPA may 

only amend promulgated MACT standards by means of the periodic 

review procedures of section 112 (d) (6), which does not include 

re-determining floor levels. Section 112 (d)(6)does not 

indicate that it is the exclusive means of amending MACT 

standards, and in particular does not speak to a situation where 

an original floor was palpably short of statutory requirements 

and where that floor became the ultimate standard. EPA 

consequently believes it has discretion to reconsider and redo 

the MACT floor analysis for PM, and to amend the standard as 

appropriate. 

Other commenters suggested that even if EPA has such 

discretion, it would (or should) be limited to a reanalysis of 

the original database for the 1999 rule and so should not 

consider kilns‘ subsequent performance. Were EPA to take that 

approach here, the floor (and standard) for PM would be more 

stringent than the floor (and standard) in this rule.30 Because 

EPA considers the database for the current rule to be more 

 

30 Calculation of PM MACT Floor Based on Data in 1998 Proposal. 

July 7, 2010
Page 83 of 456

representative of performance capabilities of best performing 

kilns than the sparser 1999 database, EPA is basing its 

determination on the more representative data.

EPA is setting a PM standard based on MACT for existing and 

new area source cement kilns. As noted at proposal, Portland 

cement kilns are a listed area source category for urban HAP 

metals pursuant to section 112(c)(3), and control of these metal 

HAP emissions (via the standard for the PM metal surrogate) is 

required to ensure that area sources representing 90 percent of 

the area source emissions of urban metal HAP are subject to 

section 112 control, as required by section 112(c)(3). EPA has 

determined that this standard should reflect MACT, rather than 

GACT, because there is no essential difference between area 

source and major source cement kilns with respect to emissions 

of either HAP metals or PM. Thus, the factors that determine 

whether a cement kiln is major or area are typically a function 

of the source‘s HCl or formaldehyde emissions, rather than its 

emissions of HAP metals. As a result, there are kilns that are 

physically quite large that are area sources, and kilns that are 

small that are major sources. Both large and small kilns have 

similar HAP metal and PM emissions characteristics and controls. 

Given that EPA is developing major and area source

standards for PM at the same time in this rulemaking, a common 

control strategy consequently appears warranted for these 
Page 84 of 456

emissions. We thus have included all cement kilns in the floor 

calculations for the final PM standard, and have developed 

common PM limits based on MACT for both major and area sources. 

i. Floor Determination. At proposal we had compiled PM 

stack test data for 45 kilns from the period 1998 to 2007. EPA 

ranked the data by emissions level and the lowest emitting 12 

percent, 6 kilns, was used to develop the proposed existing 

source MACT floors of 0.085 and 0.08 lb/ton clinker for new and 

existing sources respectively. 

Commenters noted that we had omitted some of the data 

already submitted to EPA in developing the MACT floor. In 

addition, we noted for two of the best performing facilities we 

had only one emissions test. Therefore we requested these 

sources to submit additional PM emission test data and the 

source sent two additional PM emissions tests for each kiln to 

allow us to better characterize emissions variability. We 

modified the PM data base to reflect these submissions. Another 

change made since proposal is that we have changed the 

compliance requirement to require a PM CEMS. This requires that 

we establish an averaging period. We chose a period of 30 days 

(rolling average) to be consistent with requirements for mercury 

and THC, and because PM emissions on a lb/ton basis are affected 

by raw mill cycles (typically encompassed within 30-days, see 74 

FR at 21144) for kilns with in-line raw mills. We have 
Page 85 of 456

converted the concentrations obtained from 3-hour tests into 30-

day values by means of the UPL equation previously described. 

It should be noted that due to the longer averaging periods, the 

actual limit will be a lower number compared to the shorter 

compliance interval in the proposed rule (30 days versus a three 

hour test). This damping of variability when a longer averaging 

period is used is well established where continuous monitors 

have been used to measure emissions, and is also accounted for 

in the ―m‖ term of the UPL equation. The results of the new 

MACT analysis are shown in Table 8. 

Table 8. PM MACT Floor

Kiln PM Emissions (lb/ton clinker)

1 0.01

2 0.01

3 0.01

4 0.03

5 0.04

6 0.04

MACT - Existing

Average 0.02

Variance 0.001

UPL 0.04

MACT - New

Average 0.01

Variance 0.00001

UPL 0.01

EPA proposed use of PM CEMS as an alternative to using a 

bag leak detector, and also solicited comment on requiring their 

use generally. 74 FR at 21157. As we noted there, performance 

specifications for PM CEMS are now available, and continuous 

monitors ―give a far better measure of sources‘ performance over 
Page 86 of 456

time than periodic stack tests‖. After considering the public 

comments, EPA continues to believe that this is the case. See 

also further discussion of this issue at Section A.3 of this 

preamble below. 

EPA does not agree with the comment that use of a CEM 

renders the standard more stringent and so results in floors 

(and standards) more stringent than those achieved by average of 

the best performing sources. First, the continuous collection 

of data used to assess compliance with this standard does not 

create a limit more stringent that otherwise allowed. As 

discussed in the preamble to the Credible Evidence Rule, 

―...continuous monitoring of the standards (has) no effect on the 

stringency of the standard...‖ (62 FR at 8326, February 24, 1997).

Further, a statistically-based adjustment to account for 

emissions variability, and which, in this case, increases the 

numerical value of the standard (and its longer averaging 

period) by fifty percent, does not make the standard more 

stringent. Finally, increasing the averaging period beyond the 

duration associated with conducting a performance test 

(typically three hours) to 30 days normally makes a standard 

more lenient because there is more opportunity to average out 

individual results. As mentioned in the description of the Salo 

and Pederson memoranda cited in Section 4.1.2.1 of the Credible 

Evidence Rule Response to Comment Document, ―...(t)he effect of 
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the change from a 3-hour averaging time to a 30-day averaging 

time is to make the standard more lenient...‖.31 

ii. Beyond the Floor Determination.

EPA did not propose beyond-the-floor standards for PM. 

This was because the cost effectiveness of adopting beyond-thefloor controls was several orders of magnitude greater than EPA 

has accepted for PM reductions in other rules where standards 

allow consideration of costs, and because the incremental amount 

of PM removed was very small (3 tpy nationwide). Consideration 

of non-air quality issues did not change this conclusion. 74 FR 

at 21155. Commenters did not challenge this analysis. EPA 

accordingly is not adopting beyond-the-floor standards for PM. 

The final PM emissions limit for existing sources is 0.04 

pounds per ton (lb/ton) clinker for and 0.01 lb/tons clinker for 

new sources (30-day average). Kilns where the clinker cooler 

gas is combined with the kiln exhaust and sent to a single 

control device for energy efficiency purposes (i.e., to extract 

heat from the clinker cooler exhaust) will be allowed to adjust 

the PM standard to an equivalent level accounting for the 

increased gas flow due to combining of kiln and clinker cooler 

exhaust (an action for which EPA received no adverse comment). 

See 74 FR at 21156 and 73 FR at 64090-91 (Oct. 28, 

 

31 Available at 

http://www.epa.gov/ttncaaa1/t1/fr_notices/certcfin.pdf>.
Page 88 of 456

2008)(explaining the equivalency of this standard and the energy 

efficiency benefits resulting from combining these gas flows). 

The PM standard is a 30-day rolling average and is measured with 

a CEM.

iii. Compliance Alternative for Comingled Kiln/Clinker 

Cooler Exhaust.

As we noted at proposal, some kilns combine the clinker 

cooler gas with the kiln exhaust and send the combined emissions 

to a single control device. There are significant energy 

savings (and attendant greenhouse gas emission reductions) 

associated with this practice, since heat can be extracted from 

the clinker cooler exhaust. However, there need to be different 

conversion factors from concentration to mass per unit clinker 

in these cases to allow for the increased gas flow, which result 

in a different PM emissions limit. We proposed adjustment 

factors that would account for these differences and create a 

site specific PM emission limit of this situation. See 74 FR 

21155-56 and 21184. We received no comments on these factors

and are thus adopting them as proposed, except that the factors 

have been changed to account for changes in the underlying kiln 

and clinker cooler emissions limits. Note that adjustments 

would also be necessary for kilns subject to the NSPS PM limit. 

Thus, we are including a cross reference for the NSPS to the 

appropriate section of the NESHAP rule. 
Page 89 of 456

f. Opacity Standards for Kilns and Clinker Coolers. 

We are removing all opacity standards for kilns and clinker 

coolers because these sources will be required to monitor 

compliance with the PM emissions limits by more accurate means. 

Although some commenters requested retention of opacity as a 

backup standard, and others as an alternative, none of these 

comments offered any convincing information or other 

justification for perpetuating a less reliable compliance 

methodology. Though we have preserved some regulation text, any 

kiln or clinker cooler that uses a PM CEMS to monitor compliance 

with the PM emission limit is exempt from opacity standards.

g. PM Standard for Clinker Coolers

In addition to amending the PM standard for kilns we are 

similarly amending the PM emissions limit for clinker coolers. 

Fabric filters are the usual control for both cement kilns and 

clinker coolers. As EPA noted in our proposed revision to the 

NSPS (73 FR 34078, June 16, 2008), we believe that the current 

clinker cooler controls can meet the same level of PM control 

that can be met by the cement kiln. No commenter challenged 

this. One commenter did state that PM limits for clinker 

coolers should not be changed, but we disagree with that comment 

for the reasons previously discussed on the PM limit for kilns. 

Therefore, we are setting the same PM emissions limits and 

compliance requirements for both clinker coolers and kilns. 
Page 90 of 456

h. Standards for Open Clinker Piles

 At proposal we noted that open clinker piles were currently 

unregulated, and that hexavalent chromium emissions had been 

detected in fugitive dust from these piles. See 74 FR at 21163. 

We requested comment and information as to how common the 

practice of open clinker storage is, appropriate ways to detect 

or measure fugitive emissions (ranging from open-path techniques 

to continuous digital or intermittent manual visible emissions 

techniques), any measurements of emissions of hexavalent 

chromium (or other HAP) from these open storage piles, potential 

controls to reduce emissions, or any other factors we should 

consider. 

Commenters did not provide data on this practice. Industry 

commenters stated emission were de minimis and should not be 

regulated. Other commenters noted that the fact that we know 

these sources emit HAP is sufficient to necessitate regulation. 

We agree that these operations do emit HAP and that 

regulation of these sources is necessary. See National Lime, 

233 F. 3d at 640 (upholding EPA position that de minimis 

exceptions are not to be read into the MACT standard setting 

process). Because the emissions in question are fugitive dust 

for which measurement is not feasible since (by definition) the 

emissions are not emitted through a conveyance or other device 

which allows their measurement (see section 112 (h) (1) and 
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(2)(A)), we are adopting the work practice standards and opacity 

emissions limits contained in Rule 1156 as amended by the South 

Coast Air Quality Management District on March 6, 2009 and 

incorporating them into this rule. There are only two plants 

which EPA can state definitively have open storage piles and are 

complying with Rule 1156, so these existing regulatory standards 

would constitute a floor level of control (and EPA does not 

believe beyond-the-floor controls are needed, since utilizing 

some type of enclosure should well control fugitive emissions). 

A summary of the requirements are as follows:

If clinker material storage and handling activities occur 

more than 1,000 feet from the facility property-line, 

o Utilize a three-sided barrier with roof, provided the 

open side is covered with a wind fence material of a 

maximum 20 percent porosity, allowing a removable 

opening for vehicle access. The removable wind fence 

for vehicle access may be removed only during minor or 

routine maintenance activities, the creation or 

reclamation of outside storage piles, the importation 

of clinker from outside the facility, and reclamation 

of plant clean-up materials. The removable opening 

shall be less than 50 percent of the total surface 

area of the wind fence and the amount of time shall be 

minimized to the extent feasible; 
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o Storage and handling of material that is immediately 

adjacent to the three-sided barrier due to space 

limitations inside the structure shall be contained 

within an area next to the structure with a wind fence 

on at least two sides, with at least a 5 foot 

freeboard above the top of the storage pile to provide 

wind sheltering, and shall be completely covered with 

an impervious tarp, revealing only the active 

disturbed portion during material loading and 

unloading activities; 

o Storage and handling of other active clinker material 

shall be conducted within an area surrounded on three 

sides by a barrier or wind fences with one side of the 

wind fence facing the prevailing wind and at least a 

5-foot freeboard above the top of the storage pile to 

provide wind sheltering. The clinker shall remain 

completely covered at all times with an impervious 

tarp, revealing only the active disturbed portion 

during material loading and unloading activities. The 

barrier or wind fence shall extend at least 20 feet 

beyond the active portion of the material at all 

times; and 

o Inactive clinker material may be alternatively stored 

using a continuous and impervious tarp, covered at all 
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times, provided records are kept demonstrating the 

inactive status of such stored material. 

 If clinker material storage and handling activities occur 

1,000 feet or less from the facility property-line these 

activities must be in an enclosed storage area. 

In the SCAQMD regulation, there are different requirements 

for active vs. inactive open clinker piles. An inactive pile is 

one that had not been disturbed for 30 consecutive days. In 

addition, the ACAQMD rule has different requirements for clinker 

piles that are 1,000 feet or less form the facility propertyline. This 1000 foot criterion was a mutually agreed number 

among the stakeholders (both industry and environmental groups) 

involved in developing the regulation.32 Given the lack of 

additional data, we saw no reason to change these criterion. 

More information on this rule is available at 

http://www.aqmd.gov/hb/gb_cal95.html. 

Industry commenters also maintained that regulation of open 

storage piles would violate a 2001 settlement agreement between 

EPA and the industry in which EPA agreed that the 1999 rule did 

not apply to fugitive emission sources. But nothing in that 

settlement agreement prevents EPA from amending its regulations 

if it is appropriate to do so (nor could EPA legally bind itself 

 

32 Telecon with Tuyet-Le Pham, South Coast Air Quality Management 

District. June 29, 2010.
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in such a way). The agreement in fact states that ―[n]othing in 

this Agreement shall be construed to limit or modify EPA's 

discretion to alter, amend, or revise, or to promulgate 

regulations that supersede, the regulations identified in 

section III of this Agreement.‖ Consequently, EPA‘s action 

today properly amends the current regulation, and does not 

violate any provisions of the settlement agreement. 

i. Format of the Normalized Standards in the NESHAP and 

the NSPS

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. As we noted at the NSPS 

proposal, the current NSPS and limits (and NESHAP limits before 

today‘s amendments) for PM are expressed on a pound of PM per 

ton (lb/ton) of dry feed input format. See 73 FR at 34075-76. 

In this final NESHAP (and NSPS) we are adopting a new 

normalizing parameter of lb/ton of clinker – i.e., normalizing 

based on kiln output rather than input for both PM and mercury.

We noted at proposal of the NSPS that adopting an outputbased 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. 73 FR at 34076. EPA therefore proposed that all of 
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the NSPS (for PM, NOx, and SO2) be normalized by ton of clinker 

produced, and later proposed the same parameter for the two 

standards in the NESHAP which are normalized, mercury and PM. 73 

FR at 34076; 74 FR at 21140.

In this final NESHAP (and NSPS) we are therefore adopting a 

new normalizing parameter of lb/ton of clinker – i.e. 

normalizing based on kiln output rather than input – for mercury 

and PM in the NESHAP, and for PM, NOx, and SO2 in the NSPS. 

Commenters either supported this proposal, or did not question 

that normalizing by output promotes more efficient production. 

However, commenters from industry raised technical objections 

and concerns to the proposal. They maintained that the 

measurement of kiln output is not as exact as the measurement of 

kiln input, and that many kilns have not installed clinker 

measuring equipment. These objections do not necessitate 

normalizing by inputs. Most commenters also stated that kiln 

feed could be accurately measured and also indicated that most 

facilities currently derive reasonable feed-to-clinker 

conversion factors from these measurements. Kilns already 

calculate clinker production in this way when required to meet 

emissions limits normalized by clinker production, as many NSR 

and PSD permits for cement kilns presently do.33 

 

33 RACT/BACT/LAER Clearing house Report for Portland Cement. 

November 25, 2009.
Page 96 of 456

Since it appears from comments that the equipment to accurately 

measure clinker is not typically installed in this industry, we 

must assume these facilities use a feed-to-clinker conversion 

factor to calculate clinker production on whatever time basis is 

necessary (e.g., daily, hourly, etc.). Therefore, we have 

modified the rule language to more clearly provide the option 

allowing facilities to measure feed inputs and to use their site 

specific feed/clinker ratio to calculate clinker production (and 

to make clear that no prior approval from a regulatory authority 

is necessary to do so). Facilities would be allowed to use a 

constant feed/clinker ratio in accord with their usual cycles 

for determining such ratios, typically on a monthly basis when 

clinker inventories are reconciled. 

 Commenters were nonetheless concerned that because 

clinker/feed ratios change somewhat and are only re-determined 

at the end of a cycle, a slight change in clinker/feed ratio, 

determined at the end of the cycle, could show lack of 

compliance without even an opportunity to alter operation. To 

obviate this legitimate concern, the rule provides that 

facilities are not required to retroactively update clinker 

production estimates after recomputing feed/clinker ratios. We 

would not expect that the clinker/feed ratio will change 

significantly from month to month, so we do not see this as 

creating a situation where facilities will be able to have large 
Page 97 of 456

amounts of excess emissions but still be considered in 

compliance (especially since the 30-day standards are all 

rolling averages). 

 So, for these reasons above we are adopting emission 

limits normalized by kiln output for PM in both the NESHAP and 

the NSPS, for mercury in the NESHAP, and for NOx and SO2 in the 

NSPS (the same analysis applying to the limits in the NSPS). 

2. What are the final operating limits under subpart LLL?

EPA is eliminating the restriction, adopted in the 2006 

rule, on the use of fly ash where the mercury content of the fly 

ash has been increased through the use of activated carbon once 

the kiln has complied with a numerical mercury emissions limit. 

Given the emission limitation for mercury, whereby kilns must 

continuously meet the mercury emission limits described above 

(including when using these materials) there does not appear to 

be a need for such a provision. This provision is removed once 

a kiln is in compliance with the mercury limitations adopted in 

this. We are removing the requirement at compliance, rather 

than when the rule takes effect, to prevent the possibility of 

additional mercury emissions between the rule‘s effective date 

and the required compliance date. However, once the rule takes 

effect EPA is removing the requirement to maintain the amount of 

cement kiln dust wasted during testing of a control device, and 

the provision requiring that kilns remove from the kiln system 
Page 98 of 456

sufficient amounts of dust so as not to impair product quality

for the same reasons. In this case, we do not see immediate 

removal of these provisions as creating a likelihood of 

increased mercury emissions prior to the compliance date.

3. What are the final testing and monitoring requirements under

subpart LLL?

Kilns will be required to meet the following changed 

monitoring/testing requirements:

 CEMS (PS-12A) or sorbent trap monitors (PS-12B) to 

continuously measure mercury emissions, along with 

Procedure 5 for ongoing quality assurance.

 CEMS meeting the requirement of PS-8 to measure THC 

emissions for existing sources. (New sources are already 

required to monitor THC with such a CEMS). Kilns meeting 

the organic HAP alternative to the THC limit will still be 

required to continuously monitor THC (based on the results 

of THC monitoring done concurrently with the Method 320 

test), and will also be required to test emissions using 

EPA Method 320 or ASTM D6348-03 every 30 months to identify 

the organic HAP component of their THC emissions. 

 Installation and operation of a PM CEMS that meets the 

requirements of PS-11. 

 CEMS meeting the requirements of PS-15 will be required to 

demonstrate compliance with the HCl standard for all kilns 
Page 99 of 456

except those using a caustic scrubber. If a facility is 

using a caustic scrubber to meet the standard, EPA Test 

Method 321 and ongoing continuous parameter monitoring of 

the scrubber may be used in lieu of a CEMS to demonstrate 

compliance. The M321 test must be repeated every 30 

months. 

Raw material dryers that are existing sources will also be 

required to install and operate CEMS meeting the requirement of 

PS-8 to measure THC emissions. (New raw material dryer sources 

are already required to monitor THC with a CEMS). Raw material 

dryers meeting the organic HAP alternative to the THC limit will 

still be required to continuously monitor THC (based on the 

results of THC monitoring done concurrently with the Method 320 

test), and will also be required to test emissions using EPA 

Method 320 or ASTM D6348-03 every 30 months to identify the 

organic HAP component of their THC emissions. 

New or reconstructed raw material dryers and raw or finish 

mills will be subject to longer Method 22 and, potentially, to 

longer Method 9 tests. The increase in test length duration is 

necessary to better reflect the operating characteristics of 

sources subject to the rule. EPA has included the costs 

associated with increased test duration in its estimates of the 

rule‘s costs.
Page 100 of 456

The requirements above are the same as those proposed with 

the following exceptions. 

For kilns and clinker coolers, EPA proposed to require bag 

leak detection systems for fabric filters and an ESP predictive 

model to monitor performance of an ESP. In this final rule we 

are requiring the use of a PM CEMS for all PM control devices. 

We did receive comments on technical issues associated with PM 

CEMS, which we have addressed in the Comments and Responses 

Document in the docket to this rulemaking. As explained 

earlier, we continue to believe that these devices provide the 

most positive indication that a facility is actually complying 

with the PM emissions limit. We also note that we promulgated a 

requirement for PM CEMS in the 1999 final rule but deferred the 

compliance date until the establishment of performance 

specifications. These specifications have now been established 

as EPA Performance Specification 11. 

In the proposed rule we specified that THC CEMS must meet 

the requirements of performance specification 8A. Commenters 

correctly pointed out certain deficiencies of the 8A method as 

applied to this source category. In response to those comments 

we have changed the requirement to PS-8.

Where periodic performance tests are required for HCl we 

changed the test frequency to 30 months because a commenter 

noted both chlorine inputs and scrubber performance may change 
Page 101 of 456

significantly over five years. For similar reasons we changed 

the testing frequency for the organic HAP option to 30 months. 

We believe aligning the test schedules for all pollutants 

(dioxin furan, organic HAP, and HCl) to the same testing 

schedule will allow for more efficient use of testing resources. 

4. Standards for Startup and Shutdown

As noted above, the United States Court of Appeals for the 

District of Columbia Circuit vacated portions of two provisions 

in EPA‘s CAA section 112 regulations governing the emissions of 

HAP during periods of SSM. Sierra Club v. EPA, 551 F.3d 1019 

(D.C. Cir. 2008), cert. denied, 130 S. Ct. 1735 (U.S. 2010). 

Specifically, the Court vacated the SSM exemption contained in 

40 CFR 63.6(f)(1) and 40 CFR 63.6(h)(1), that are part of a 

regulation, commonly referred to as the ―General Provisions 

Rule,‖ that EPA promulgated under section 112 of the CAA. When 

incorporated into CAA section 112(d) regulations for specific 

source categories, these two provisions exempt sources from the 

requirement to comply with the otherwise applicable CAA section 

112(d) emission standard during periods of SSM.

The effect of the vacatur is that the cross-reference to 40 

CFR 63.6(f)(1) and 40 CFR 63.6(h)(1) in Table 2 to subpart LLL 

no longer operates to incorporate an SSM exemption. 

In light of the Sierra Club decision, EPA proposed to 

require that sources be in continuous compliance with emissions 
Page 102 of 456

limits at all times, even during startup, shutdown, and 

malfunction. 74 FR at 21161-62. We proposed that these sources 

meet the same standards at all times. Id. We also specifically 

asked for information on emissions during startup, shutdown, and 

malfunction. 

In these final amendments we have eliminated the crossreference to the vacated General Provisions‘ exemptions 

contained in Table 1 of current subpart LLL. In establishing 

the standards in this rule, EPA has taken into account cement 

kilns‘ operating properties during startup and shutdown periods 

and, for the reasons explained below, has established different 

standards for those periods. EPA is not setting separate 

standards for malfunctions so that, for the reasons explained 

below, the standard that applies during normal operations 

applies during periods of malfunctions. We have also revised 

Table 2 (the General Provisions table) in several respects. For 

example, we have eliminated the General Provisions‘ requirement 

that the source develop an SSM plan. We have also removed

certain recordkeeping and reporting requirements related to the 

SSM exemption. EPA has attempted to ensure that we have not 

incorporated into the regulatory text any provisions that are 

inappropriate, unnecessary, or redundant in the absence of the 

SSM exemption. 
Page 103 of 456

Startup is the period of time between when fuel is first 

introduced into a cement kiln that is not firing fuel, and when 

the kiln temperatures are within normal operating limits, the 

kiln is using its normal operating fuel, and the kiln is 

producing clinker. During kiln startup, fuel is first 

introduced into the kiln to raise the kiln to the appropriate 

operating temperatures. In the case of a cold start the fuel is 

typically a natural gas or distillate fuel. Once the kiln 

reaches certain temperatures, the normal operation fuel is 

introduced. After the kiln reaches stable operating 

temperatures, kiln feed is introduced in low amounts which are

gradually increased. Because the kiln feed is a significant 

source of most kiln emissions (HAP and otherwise) we would 

consequently expect that kiln emissions, on a concentration 

basis, would not be any higher during startup than during normal 

operations, with any potential short-term emission spikes due to 

transient conditions or release of emissions from materials left 

in the kiln from the last operating period being accommodated 

through an averaging period. Indeed, on a pure concentration 

basis, kiln emissions over time would likely be lower than 

during normal operation given the lesser volume of inputs being 

processed, and (at startup) the cleaner fuel being used to heat 

the kiln to normal operating conditions.
Page 104 of 456

Notwithstanding that stack concentrations over time would 

likely be the same or less than during normal operation, in some 

cases, the manner in which the standard is expressed is not 

appropriate during startup. Most particularly, the mercury and 

PM standards are normalized to kiln production (amount of 

pollutant allowed being linked to a ton of clinker produced). 

During startup, production is by definition either non-existent 

or very low. Even where there is a modest amount of production 

during startup, relationships between HAP concentration and 

amount of product are skewed so as to make this means of 

measurement inappropriate. In addition, normalized standards 

require accurate measurements of kiln volumetric flow rate (used 

to convert concentration into mass) and kiln flow rate, which

changes in important ways from normal values during startup. 

When considered along with such phenomena as varying kiln stack 

moisture contents and flow rate, flow rate measurements are 

significantly less accurate during startup than during normal 

operation.

For these reasons, we are establishing standards for 

mercury and PM by converting the normal operation standards to a 

concentration basis. These conversions are as follows: 55 lb 

mercury/MM tons clinker is equivalent to 10 micrograms per dry 

standard cubic meter (ug/dscm); 21 lb mercury/MM tons clinker is 

equivalent to 4 ug/dscm; 0.04 lb PM/ton clinker is equivalent to 
Page 105 of 456

0.004 grains per dry standard cubic foot (gr/dscf); and 0.01 lb 

PM/ton clinker is equivalent to 0.0008 gr/dscf. Mercury and PM 

would be measured during startup with a CEMS (as during normal 

operation) and the concentration standard would be met on the 

basis of 7-day averages. We do not believe a 30-day average is 

appropriate for these periods because they are of short 

duration, and it might take a period of 1 year or more to 

accumulate 30 days of startup operation. We considered an 

averaging period equal to the time period of each startup, but 

that would have meant different averaging periods for each 

event. Therefore, we chose 7 days as a period short enough to 

accumulate the data necessary to calculate the average over a 

reasonable period (certainly less than a year) but long enough 

to allow averaging out any transient spikes that may occur. In 

this way, short-term spikes which occur during startup would be 

averaged against the lower concentrations which otherwise 

typically maintained. A consequence of this compliance regime 

(as for the standards which apply during normal operation), is 

that a source (at least initially) cannot determine compliance 

based on any single startup (or shutdown) event. Seven days of 

data will need to be averaged. 

All of the discussion above applies to THC emissions during 

startup: feed (the main source of THC emissions) is introduced 

gradually so THC emissions should ordinarily be lower, cleaner 
Page 106 of 456

fuels are initially used to heat the kiln to normal 

temperatures, etc. The difference is that the THC standard is 

already expressed as a concentration, so the measurement 

difficulties with a normalized standard do not exist. However, 

during normal operation the THC standard is corrected to a 

specified oxygen concentration to avoid the situation where a 

facility uses dilution air to lower the measured concentration. 

At startup, oxygen concentrations may be higher that during 

normal operation, and may also fluctuate more. This could have 

the effect of actually making the standard more stringent during 

startup. Consequently, EPA is adopting the same concentration 

standard for THC during startup as applies during normal 

operation, but is removing the oxygen concentration correction 

factor. The standard is measured with a CEMS and is based on a 

7-day average so, that, again the lower concentrations which 

ordinarily maintain at startup should balance out any transient 

events that occur because the kiln is not yet in steady state 

mode.

HCl is also expressed as an un-normalized stack 

concentration corrected to a specific oxygen concentration. 

Where measured with a CEMS, EPA knows of no reason the same 

standard as applies during normal operation should not be met 

during startup, except that the averaging period would be 7 days 

and the oxygen correction factor would be removed for the 
Page 107 of 456

reasons noted above. However, for those units equipped with wet 

scrubbers, sources may choose to demonstrate compliance by means 

of stack testing and parametric monitoring. See Section IV.A.3. 

In such a circumstance, there are no parameters to measure 

because HCl will not be emitted. This is because HCl is emitted 

only as kilns begin burning normal fuel, not the natural gas or 

distillate used as a fuel during startup. Consequently, EPA is 

providing that emissions of HCl shall be zero at all such times 

as distillate or natural gas is used to fire the kiln (and that 

is the parameter which would be measured).

The current standard for dioxins and furans is expressed 

either as a concentration, or a combination of concentration and 

temperature control at the inlet to the PM control device. 

Continuous compliance is determined based on demonstrating the 

measured temperature at the inlet to the PM control device does 

not exceed the limit established during dioxin compliance 

testing. This is because higher PM control inlet temperature 

can increase dioxin emissions. See 63 FR 14196, March 24, 1998. 

Based on a comment indicating that there can be an increase in 

short-term temperature fluctuations during startup (and 

shutdown), EPA is indicating in the startup standard that 

temperature measurements can increase by 10 percent during these 

periods.
Page 108 of 456

Shutdown is the period of time between when kiln raw 

material feed is shutoff and gas flow through the kiln ceases. 

Shutdown operations are in many ways a mirror image of startup. 

During shutdown, the same transient conditions and low product 

production rates occur as during startup. Cement kilns cannot 

be immediately shut off. Even after the feed is stopped, gas 

flow must be continued through the kiln and the kiln continues 

to rotate to prevent kiln overheating and/or warping. Moreover, 

the concerns about inability to have normalized standards or 

standards with oxygen correction factors, air pollution control

inlet temperature variability, and lack of measureable HCl 

emissions when the kiln is fired with distillate or natural gas 

and is not HCl CEM-equipped, all apply at shutdown for the same 

reasons as at startup. For this reason, we are setting the same 

limits for kilns during shutdown operations as during startup.

Periods of startup, normal operations, and shutdown are all 

predictable and routine aspects of a source‘s operations. In 

the proposed rule, EPA expressed the view that there are 

different modes of operation for any stationary source, and that 

these modes generally include startup, normal operations, 

shutdown, and malfunctions. 74 FR at 21162. However, after 

considering the issue of malfunctions more carefully, EPA 

believes that malfunctions are distinguishable from startup, 

shutdown and normal operations. Malfunction is defined as a 
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―sudden, infrequent, and not reasonably preventable failure of 

air pollution control and monitoring equipment, process 

equipment or a process to operate in a normal or usual manner * 

* * ‘‘(40 CFR 63.2). EPA has determined that malfunctions 

should not be viewed as a distinct operating mode or condition 

and, therefore, any emissions that occur at such times do not 

need to be factored into development of CAA section 112(d) 

standards, which, once promulgated, apply at all times. In 

Mossville Environmental Action Now v. EPA, 370 F.3d 1232, 1242 

(D.C. Cir. 2004), the court upheld as reasonable standards that 

had factored in variability of emissions under all operating 

conditions. However, nothing in section 112(d) or in caselaw 

requires that EPA anticipate and account for the innumerable 

types of potential malfunction events in setting emission 

standards. See, Weyerhaeuser v Costle, 590 F.2d 1011, 1058 

(D.C. Cir. 1978)(― In the nature of things, no general limit, 

individual permit, or even any upset provision can anticipate 

all upset situations. After a certain point, the transgression 

of regulatory limits caused by "uncontrollable acts of third 

parties," such as strikes, sabotage, operator intoxication or 

insanity, and a variety of other eventualities, must be a matter 

for the administrative exercise of case-by-case enforcement 

discretion, not for specification in advance by regulation.‖) 

Further, it is reasonable to interpret section 112(d) as 
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not requiring EPA to account for malfunctions in setting 

emissions standards. For example, we note that Section 112 

uses the concept of ―best performing‖ sources in defining MACT, 

the level of stringency that major source standards must meet. 

Applying the concept of ―best performing‖ to a source that is 

malfunctioning presents significant difficulties. The goal of 

best performing sources is to operate in such a way as to avoid 

malfunctions of their units. 

Moreover, even if malfunctions were considered a distinct 

operating mode, we believe it would be impracticable to take 

malfunctions into account in setting CAA section 112(d) 

standards for this (or any other) source category. As noted 

above, by definition, malfunctions are sudden and unexpected 

events and it would be difficult to set a standard that takes 

into account the myriad different types of malfunctions that can 

occur across all sources in the category. Moreover, 

malfunctions can vary in frequency, degree, and duration, 

further complicating standard setting. 

In the event that a source fails to comply with the 

applicable CAA section 112(d) standards as a result of a 

malfunction event, EPA would, of course, determine an 

appropriate response based on, among other things, the good 

faith efforts of the source to minimize emissions during 

malfunction periods, including preventative and corrective 
Page 111 of 456

actions, as well as root cause analyses to ascertain and rectify 

excess emissions. EPA would also consider whether the source's 

failure to comply with the CAA section 112(d) standard was, in

fact, ―sudden, infrequent, not reasonably preventable‖ and was 

not instead ―caused in part by poor maintenance or careless 

operation.‖ 40 C.F.R. § 63.2 (definition of malfunction).

In response to comments urging that EPA not apply the same 

standards to malfunctions as to normal operation, EPA recognizes

that even equipment that is properly designed and maintained can 

sometimes fail and that such failure can sometimes cause an 

exceedance of the relevant emission standard. (See, e.g., State 

Implementation Plans: Policy Regarding Excessive Emissions 

 During Malfunctions, Startup, and Shutdown (Sept. 20, 1999); 

Policy on Excess Emissions During Startup, Shutdown, 

Maintenance, and Malfunctions (Feb. 15, 1983)). EPA is 

therefore adding to the final rule an affirmative defense to 

civil penalties for exceedances of emission limits that are 

caused by malfunctions. See 40 CFR 63.1341 (defining 

―affirmative defense‖ to mean, in the context of an enforcement 

proceeding, a response or defense put forward by a defendant, 

regarding which the defendant has the burden of proof, and the 

merits of which are independently and objectively evaluated in a 

judicial or administrative proceeding). We also added other 

regulatory provisions to specify the elements that are necessary 
Page 112 of 456

to establish this affirmative defense; the source must prove by 

a preponderance of the evidence that it has met all of the 

elements set forth in 63.1344. (See 40 C.F.R. 22.24). The 

criteria ensure that the affirmative defense is available only 

where the event that causes an exceedance of the emission limit 

meets the narrow definition of malfunction in 40 C.F.R. 63.2 

(sudden, infrequent, not reasonable preventable and not caused 

by poor maintenance and or careless operation). The criteria 

also are designed to ensure that steps are taken to correct the 

malfunction, to minimize emissions in accordance with section 

63. 1348(d) and to prevent future malfunctions. In any judicial 

or administrative proceeding, the Administrator may challenge 

the assertion of the affirmative defense and, if the respondent 

has not met its burden of proving all of the requirements in the 

affirmative defense, appropriate penalties may be assessed in 

accordance with Section 113 of the Clean Air Act (see also 40 

C.F.R. Part 22.77). 

5. What are EPA‘s final actions on compliance dates? 

For existing sources we proposed a compliance date of 3 

years after the promulgation of the new emission limits for 

mercury, THC, PM, and HCl to take effect. This is the maximum 

period allowed by law. See section 112(i)(3)(A). We continue 

to believe a 3 year compliance period is justified because most 

facilities will have to install emissions control devices (and 
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in some cases multiple devices) to comply with the proposed 

emissions limits. Therefore, we have retained a 3 year 

compliance data in this final rule. 

For new sources, the compliance date will be the effective 

date of this final rule or startup, whichever is later. Because 

this is a major rule as defined by the Congressional Review Act, 

the effective date of the rule is 60 days after publication of 

the Federal Register. 

In determining the proposal date that determines if a 

source is existing or new, we have decided to select the 

proposal date of these final amendments, which is May 6, 2009, 

for all the standards. 

At proposal, we considered three possible dates, including 

March 24, 1998; December 5, 2005; and the proposal date of these 

final amendments, which was May 6, 2009. As we noted at 

proposal, Section 112 (a)(4) of the Act states that a new source 

is a stationary source if ―the construction or reconstruction of 

which is commenced after the Administrator first proposes 

regulations under this section establishing an emissions 

standard applicable to such source.‖ ―First proposes‖ could 

refer to the date EPA first proposes standards for the source 

category as a whole, or could refer to the date the agency first 

proposes standards under a particular rulemaking record or first 

proposes the particular standards at issue. The definition is 
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also ambiguous with regard to whether it refers to a standard 

for the source as a whole, or to a HAP-specific standard (so 

that there could be different new source standards for different 

HAP which are regulated at different times).34 At proposal we 

chose the date of December 5, 2005, as the proposal date that 

determines if a source is new or existing for the mercury, HCl, 

and THC, and the May 6, 2009, date for PM. 

After consideration of comments on the selection of the 

date for mercury, THC, and HCl, we believe that the May 6, 2009, 

date for all pollutants is more in keeping with the evident 

intent of Section 112 (a)(4) that source should have sufficient 

notice that new source controls requirements can be considered 

in the initial design. We accept commenters‘ argument that 

sources coming into existence between the proposed date of the 

2006 standards and the May 6, 2009, proposal date of these 

amendments would have no reasonable means of ascertaining the 

standards‘ final content and so lacked notice of what controls 

and strategies to adopt. Since this is antithetical to the 

policy underlying new source standards, EPA is adopting May 6, 

2009, as the date which determines if a source is existing or 

new.

 

34 See also 74 FR at 21158 n. 41 citing other statutory 

provisions indicating that the phrase ―first proposes‖ can have 

a number of meanings. 
Page 115 of 456

We note that there are currently sources subject to new 

source limits for mercury and THC contained in the December 20, 

2006, rule. However, the mercury the new source standards in 

this final rule are significantly different than the limits in 

the December 20, 2006, rule, and we do not see how the affected 

sources could have anticipated this change prior to proposal of 

these amendments. Accordingly, we have selected a date that 

allows these facilities to design and install the required 

control equipment. 

B. What are EPA‘s Final Actions on to 40 CFR part 60, subpart

F? 

1. What are the final kiln and clinker cooler emissions limits

under 40 CFR part 60, subpart F?

For ―new‖ affected facilities constructed, modified, or 

reconstructed after June 16, 2008, the final emission limits

amend the existing rules as follows: 

 Change the format of the PM emission limits from lb/ton of 

dry feed to lb/ton of clinker product; 

 Reduce the PM emission limit for kilns from 0.3 lb/ton of 

dry feed to 0.01 lb/ton of clinker;

 Set a limit on NOx emissions from kilns of 1.50 lb/ton of 

clinker; and
Page 116 of 456

 Set a limit on SO2 emissions from kilns of 0.4 lb/ton of 

clinker, or, as an alternative, demonstrate a reduction in 

SO2 emissions from the kiln of at least 90 percent; and

 Reduce the PM emissions limit for clinker coolers from 0.1 

lb/ton dry feed to 0.01 lb/ton of clinker.

The emission limits for affected facilities constructed, 

modified, or reconstructed before June 16, 2008, remain 

unchanged in this subpart. The rationale for these actions is 

discussed below 

a. NOx Limits for Kilns

EPA proposed a NOx limit of 1.5 lb/ton of clinker based on 

application of Selective Non-Catalytic Reduction (SNCR) to a new 

precalciner kiln. At proposal we also considered a level of 

1.95 lb/ton clinker based on the use of SNCR control technology, 

and a limit of 0.5 lb/ton clinker based on the use of selective 

catalytic reduction (SCR) technology.

After evaluation of the comments, we have decided to adopt 

the level of 1.5 lb/ton clinker in this final rule, as proposed. 

In general, commenters agreed with the selection of SNCR as the 

basis of the standard (i.e., it represents the performance of 

BDT). However, there was disagreement over the appropriate 

emission limit that represents BDT. 

Industry commenters requested a higher limit, claiming that 

site specific properties of raw materials could create a 
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situation where application of SNCR technology to a well 

designed preheater/precalciner kiln could not achieve the level 

of 1.5 lb/ton clinker without high ammonia injection rates that 

would result in significant ammonia emissions. To support their 

arguments they noted that EPA based the 1.5 lb/ton clinker level 

on the assumption that a well designed new preheater/precalciner 

kiln could meet a level of 3.0 lb/ton clinker without SNCR, so 

that this 3.0 lb/ton clinker should be the baseline from which 

performance of SNCR is evaluated. 73 FR at 34079. They pointed 

to several newer kilns that had difficulty meeting a level of 

3.0 lb/ton clinker without SNCR, and attributed this difficulty 

to ―hard to burn‖ raw materials at certain sites. 

We have rejected the industry argument that 1.5 lb/ton 

clinker is not achievable for all new kilns using SNCR 

technology for the following reasons. First, the commenters 

note some kilns without SNCR cannot meet a NOx level of 3.0 

lb/ton clinker. However, they did not provide the actual levels 

of NOx emissions the sources were designed to meet. The NOx 

emissions for a new preheater/precalciner kiln are primarily a 

function of precalciner design. Though two kilns may have the 

same basic precalciner design, certain site specific design 

parameters will also affect NOx emissions. A precalciner 

designed to meet a level above 3.0 lb/ton clinker, will not 

necessarily be designed exactly the same way as one designed to 
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meet 3.0 lb/ton clinker. We are also aware that there are kiln 

precalciner designs that were installed that do not represent 

best design. We thus do not believe that these kilns‘ 

performance alters the baseline from which performance of SNCR 

is evaluated. In addition, we have enough examples of new 

preheater/precalciner kilns in various locations in the country 

to indicate to us that a NOx limit of 3.0 lb/ton clinker is 

generally achievable, regardless of location, if the precalciner 

is properly designed. For example, several kilns in Florida and 

a kiln in California have NOx emissions below 2.0 lb/ton clinker 

with no add-on controls. According to our information, raw 

materials in Florida can be considered ―hard to burn‖ because of 

the significantly different hardness of Florida limestone and 

silica (limestone being soft which create a fine grind, the 

silica being harder which creates a more coarse grind) creates 

problems with size distribution for the raw material 

necessitating more fuel use and higher kiln temperatures with a 

consequent increase in NOx emissions. Additional test data for 

two plants with reported ―hard to burn‖ mix were 1.89 and 2.4 

lb/ton. Given these facts, we believe the assumption that a new 

kiln without add-on controls can meet a level of 3.0 lb/ton 

clinker over the long term is very reasonable and so should 

represent a baseline for application of SNCR performance. See 

also 73 FR at 34079 noting many other examples of kilns without 
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end-of-stack controls burning hard-to-burn inputs meeting a 

level of 2.5 lb/ton of clinker.

Second, although we based our 1.5 lb/ton clinker level on a 

SNCR emission reduction of 50 percent, there are numerous 

examples of SNCR systems achieving emission reductions greater 

than 50 percent and as high as 80 percent or more. Id. These 

reductions were achieved without appreciable ammonia slip. So 

even if a new kiln were to emit at levels above 3.0 lb/ton 

clinker without end-of-stack controls, application of SNCR would 

allow such a kiln to meet the 1.5 lb/ton clinker level. For 

example, a new kiln emitting at 4.0 lb/ton clinker would only 

need an emission reduction of 63 percent to meet the 1.5 lb/ton 

clinker level for NOx. 

Finally, the NOx limit is based on a 30-day averaging 

period to be consistent with the averaging periods for other 

regulated kiln pollutants, and to allow for averaging of raw 

mill on and off emissions. See 74 FR at 21144. Compared to 

other averaging options (hourly or daily), this longer averaging 

time allows additional operating flexibility to meet the limit.

Based on comments received, we also considered setting a 

NOx limit lower than 1.5 lb/ton clinker based on performance of 

SNCR. However, we also rejected that option. We do have data 

that indicate that some cement kilns are below 1.5 lb/ton 

clinker, but we do not believe the current data support that any 
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new kiln, regardless of location (and consequent raw material 

inputs), could meet a level that low.

At proposal we also considered a NOx emissions level of 0.5 

lb/ton clinker based on performance of SCR. We rejected that 

option because at that time we did not believe that SCR was 

sufficiently demonstrated technology for this industry. We are 

aware that there have been three cement kilns in Europe that 

have successfully used SCR, and that SCR technology is a 

demonstrated control technology for NOx control for other source 

categories, such as utility boilers. We also are aware that 

that one domestic cement company has agreed to install SCR 

technology on one kiln as part of a settlement agreement. 

However, we continue to question if SCR technology would be 

effective at all locations where new kilns might be installed. 

The main concern is the potential for dust buildup on the 

catalyst, which can be influenced by site specific raw material 

characteristics present in the facility‘s proprietary quarry, 

such as trace contaminants that may produce a stickier 

particulate than is experienced at sites where the technology 

has been installed. This buildup could reduce the effectiveness 

of the SCR technology, and make cleaning of the catalyst 

difficult resulting in kiln downtime and significant costs. We 

were unable to estimate these costs and did not include these 

costs in our overall cost estimates for SCR. For these reasons, 
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we have not selected SCR technology as the basis of BDT. We 

will continue to follow this technology as it is applied in the 

U.S., and will reconsider this decision in the next review of 

this standard.

Kilns equipped with alkali bypasses cannot be expected to 

meet the NOx limit for the portion of the exhaust that goes to 

bypass. Bypass gases are quickly cooled and do not remain at a 

temperature long enough to treated using an SNCR systems. For 

that reason, we have revised the rule to clarify that for kilns 

with an alkali bypass, only the main kiln exhaust gases are 

subject to the NOx limit. Because all kilns do not require an 

alkali bypass and the bypass gas stream is a small fraction of 

the total kiln exhaust gas flow, the any additional NOx emission 

resulting from this exclusion will be minimal. 

b. SO2 Limits for kilns

EPA proposed an emissions limit of 1.33 lb/ton clinker or 

90 percent emissions reduction SO2 based on the performance of a 

limestone wet scrubber applied to a kiln with high sulfur raw 

materials. 73 FR at 34080. Commenters noted that this level 

was considerably above the level of many of the recent best 

available control technology (BACT) determinations, and was also 

above the level actually achieved by the facility EPA used as 

the basis of this proposed standard.
Page 122 of 456

At the time EPA proposed the 1.33 lb/ton clinker limit, we 

also considered a limit of 0.4 lb/ton clinker based on the 

average of recent BACT determinations for cement kilns. We 

chose the higher limit at proposal because the 0.4 lb/ton limit 

would have resulted in new kilns with moderate sulfur content 

raw materials experiencing a cost per ton of SO2 removed of 

$6,000. However, we have changed our proposed decision for two 

reasons. First, as a result of the NESHAP requirement to meet a 

HCl emissions level of 3 ppmvd, we estimate that all new kilns 

will have to install wet scrubbers for HCl control. See section 

VI below. Hence, the cost of meeting the 0.4 lb/ton clinker 

limit in the NSPS is minimal, only the cost of the SO2 CEM. 

Second, since proposal we have revised our costs for dry lime 

injection, which is the most cost-effective control technology 

for controlling a moderate sulfur raw material kiln to the 0.4 

lb/ton clinker level. Based on our revised information, the 

cost of meeting a 0.4 lb/ton clinker emission limit now ranges 

from $470 to $1430/ton SO2 for a kiln with high or moderate 

sulfur raw materials, even if these costs are attributed to the 

NSPS rather than to the NESHAP. Kilns with low sulfur raw 

materials can meet the 0.4 lb/ton clinker level with no add-on 

controls. We consider these to be reasonable costs, comparable 

with other costs for SO2 control EPA has deemed reasonable such 

as those in the Clean Air Interstate Rule. See 70 FR at 25583 
Page 123 of 456

(May 12, 2005). So, even if a new facility is able to meet the 

NESHAP HCl limit without any acid gas controls, the cost per ton 

to meet a 0.4 lb/ton SO2 NSPS limit is still reasonable. 

In the proposal, we considered a SO2 emissions level of 0.2 

lb/ton clinker. However, this level adds little environmental 

benefit beyond the 0.4 lb.ton limit, and for many facilities 

would not be achievable based on the use of wet scrubber 

technology, which means these facilities would opt for the 90 

percent emission reduction alternative (discussed below). For 

these reasons, we did not choose this level as BDT.

We also proposed a 90 percent reduction as an alternative 

limit to the 1.33 lb/ton emissions limit. We are retaining this 

alternative in the final rule.35 The alternative 90 percent 

reduction is to account for situations where the sulfur content 

of the raw materials is so high that, even with the most 

efficient SO2 control, a kiln cannot meet the 0.4 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.36 Compliance with the 90 

percent reduction would be determined by continuously monitoring 

SO2 at the control device inlet and outlet. Continuous 

 

35 Section 111(b) specifically indicates that standards may be 

expressed as numerical limits or as percent reductions.

36 Summary of Cement Kiln Wet Scrubber and Lime Injection Design 

and Performance Data, May 29, 2008.
Page 124 of 456

monitoring of SO2 at the inlet and outlet is a positive 

demonstration that the standard is being continuously met. 

c. PM Emissions Limits for Kilns and Clinker Coolers

We proposed a PM emissions limit of 0.86 lb/ton clinker

based on fabric filters using membrane bags. This specific 

level was chosen because it is representative of the performance 

of this technology and was equivalent to the new source limit 

contained in the Hazardous Waste Combustor (HWC) NESHAP for 

cement kilns burning hazardous waste. This rationale is no 

longer applicable, since EPA is reassessing the PM limit in the 

HWC NESHAP. See USEPA Motion for Voluntary Remand in # 05-1441 

(D.C. Circuit, August 29, 2008). 

As previously discussed in section IV.A., in this action we 

are setting PM limits under the Portland Cement NESHAP of 0.04 

lb/ton clinker for existing sources and 0.01 lb/ton clinker for 

new sources based on a 30 day rolling average. We project that 

new cement kilns meeting the 0.01 lb/ton clinker limit will be 

using the same technology which formed the basis of the proposed 

NSPS PM limit, namely fabric filters and membrane bags. It 

should also be noted that we estimate that many new facilities 

will need to install fabric filters in series as part of mercury 

controls. This means that a new kiln will install PM controls 

required to meet the 0.01 lb/ton limit in any case, so 

establishing the same limit for PM in the NSPS not only is 
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technically justified, but has no cost. We also assessed the 

costs of installing and operating fabric filters with membrane 

bags at proposal, and found this to be a cost-effective control 

technology in any case. 73 FR at 34077. The technology would 

now be evaluated as more cost-effective than at proposal, since 

greater PM reductions will result from its use. Therefore, we 

are establishing an NSPS PM limit of 0.01 lb/ton clinker in this 

final NSPS, averaged over 30 days (rolling average) and measured 

with a CEM. For reasons previously discussed, we are setting 

the same limit for clinker coolers. See section IV.A.g of this 

preamble above. See section V for a discussion on measuring 

compliance with a PM CEM.

d. Change in Format of the Standard from lb/ton Feed to 

lb/ton Clinker

The change in format of the standard from feed to lb/ton 

clinker was actually proposed in the NSPS. However, this issue 

was also raised in response to the proposed PM and mercury 

limits in the NESHAP, and was previously discussed in section 

IV.A.1.i. 

e. Applicability of NSPS Limits to Modified Kilns

At proposal we had one set of emission limits for PM, SO2 

and NOx that were applicable to all new, reconstructed, and 

modified kilns. Commenters expressed concerns of the ability of 
Page 126 of 456

a modified kiln to meet the same limits as a newly constructed 

kiln. 

The PM and SO2 limits are based on control technologies that 

can be applied to any kiln type and achieve the same control 

levels that would be expected with a new kiln at similar costs. 

We see no issue here as to technical feasibility. However, this 

is not necessarily the case with NOx. New preheater/precalciner 

kilns with staged combustion achieve NOx levels in the 2.0 to 

3.0 lb/ton clinker range. As discussed above, in developing the 

NOx limit, we assumed this level as baseline in assessing the 

level achievable with SNCR, which is the technology basis of 

BDT. However, older kiln designs can have much higher NOx 

levels, ranging from 2.0 to 8.0 lb/ton clinker. Kilns in the 

higher end of the range might need to achieve an 80 percent 

emissions reduction to meet the 1.5 lb/ton clinker NOx limit. 

Industry commenters requested that EPA either exempt 

modification from the NSPS, or set separate limits. 

In this final rule we are still including modified kilns as 

an affected source. The suggestion that modified kilns be 

outright exempted from these NSPS revisions appears legally 

strained, given that modified sources are a type of new source 

for which EPA is obligated to develop, and review and revise as 

appropriate. Moreover, if we were to exempt modified kilns, 

then such sources would be free to increase emissions without 
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application of BDT, a particular concern with respect to 

pollutants like NOx which are not presently regulated by the 

NSPS. This would undermine the basis of section 111 standards, 

where Congress wanted to assure that BDT was applied to modified 

sources qualifying as ―new.‖ The purpose of the Act is to 

enhance the Nation‘s air quality (CAA section 101 (b)(1)), and 

new source performance standards under section 111 serve that 

goal. Asarco v. EPA, 578 F. 2d 319, 327 (D.C. Cir. 1978).

Commenters had also claimed that other regulatory programs, most 

notably new source review, would result in a site specific BACT 

determination if emissions increased. Though we are always 

mindful of the interrelationship of different EPA regulatory 

programs and their effects, we do not see this as sufficient 

reason not to establish a NOx emissions limits for modified 

kilns. 

We further investigated whether we should set a different 

NOx emissions limit for modified kilns. However, we believe the 

BDT is the same, and are therefore establishing the 1.5 lb/ton 

clinker as the limit for modified kilns. We have two reasons 

for doing so. First, we note that there are kilns of older 

design that meet levels below 1.5 lb/ton clinker, and in some 

cases below 1.0 lb/ton clinker, with SNCR control. Therefore, 

modified kilns would not necessarily be unable to meet the 1.5 

lb/ton clinker limit. However, sources always have the option 
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of adding sufficient NOx control to avoid an hourly emissions 

increase and avoid thus triggering the modification provision. 

Cf. Asarco, 578 F. 2d at 328 (―the operator of an existing 

facility can make any alternations he wishes in the facility 

without becoming subject to the NSPS as long as the level of 

emissions from the altered facility does not increase. Thus, 

the level of emissions before alterations take place, rather 

than the strict NSPS, effectively defines the standard that an 

altered facility must meet‖; the Court did not rule on the 

validity of these unchallenged provisions (id. at n. 32)). The 

NOx controls available to cement kilns which could be utilized 

to prevent an increase in NOx emissions, in addition to SNCR, 

are conversion to indirect firing, mid-kiln fuel injection, midkiln air injection, and substitution of steel slag for some 

limestone. 

f. Regulation of VOC/CO

We are not establishing 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 will 

be subject to a continuous 24 ppmvd THC emissions limit by the 

Portland Cement NESHAP previously discussed. Because most of 
Page 129 of 456

the THC are also VOC, the THC limit also directly limits VOC, 

and serves as the baseline for the NSPS analysis. This limit is 

also the new source limit based on the best performing source. 

Therefore we determined that no additional regulation of VOC 

emissions is necessary or feasible. 

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. As noted at proposal, the only control technology 

identified to reduce CO emissions is a RTO (which also would 

concurrently reduce any VOC emissions). However, we believe 

application of an RTO as BDT for CO would result in significant 

cost and adverse energy impacts. Therefore, we 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. 

g. Regulation of Greenhouse Gases (GHGs)
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In the proposal we did not propose standards of performance 

covering GHGs due to concerns about "issues related to the 

regulation of GHGs under the CAA" and noted that we were in the 

process of evaluating avenues for addressing such concerns. See

73 FR at 34,084. These concerns were specifically related to 

the Prevention of Significant Deterioration and Title V 

permitting programs and the unmanageable permitting burden that 

we anticipated would arise should GHGs become subject to these 

programs as a result of regulation under the Act.

Since that time, we have issued regulations for GHG 

emissions under the CAA through the light duty vehicle rule (75 

FR 25324, (May 7, 2010)) and have finalized the greenhouse gas 

―tailoring‖ rule (75 FR 31514 (June 3, 2010)) and the Johnson 

memo reconsideration (75 FR 17004 (April 2, 2010)). As a result 

of these actions, as of January 2, 2011, GHGs will become 

"subject to regulation" under the Act. Accordingly, the Agency 

has now finalized a framework addressing the concerns that were 

the basis of our decision not to propose standards of 

performance for GHG emissions from this industry at the time we 

proposed this 8-year review action. 

Today‘s final rule does not include a standard of 

performance for GHG. There are two reasons for this. First, we 

did not propose such a standard. Promulgating such a standard 

without providing opportunity to comment on it would not be a 
Page 131 of 456

logical outgrowth of the proposal and would, accordingly, 

violate the norms of notice and comment rulemaking. Second, we 

do not yet have adequate information about GHG emissions 

sufficient to set a standard. This information forms the basis 

of standards of performance, which must take into account 

achievability and cost of such controls. 

This is not the end of the matter. To the contrary, based 

on our current knowledge we believe that it may be appropriate 

for the Agency to set a standard of performance for GHGs. We 

have historically declined to propose standards for a pollutant 

where it is emitting in low amounts or where we determined that 

a BDT analysis would result in no control. National Lime 

Assoc‘n v. EPA, 627 F.2d at 426. Based on current information 

we do not believe such circumstances are present here. Without 

prejudging the outcome of a future regulatory process, we note 

the following considerations. 

First, Portland cement is one of the largest stationary 

source categories of GHG emissions, ranking as the third highest 

U.S. source of CO2 emissions. Second, based on our initial 

evaluation it appears that there are cost-effective control 

strategies for this source category that would provide an 

appropriate basis for establishing a standard of performance for 

GHG emissions. See 73 FR 44491, July 30, 2008. These control 

strategies include, for example, energy efficiency measures, 
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reductions in cement clinker content, and raw materials 

substitution. There may be other cost-effective controls as 

well.

Based upon this preliminary evaluation, the Agency is 

working towards a proposal for GHG standards from Portland 

cement facilities. We are not, however, proposing such 

standards at this time because in order to develop proposed 

standards we need additional information on site specific 

factors that affect performance of these controls, where they 

are currently applied, and control costs. We would also solicit 

information on overall facility energy management practices. To 

this end, the Agency will be sending out information requests to 

fill these information gaps so that we are able to propose a 

standard addressing GHGs in a timeframe that would allow the 

regulated community to make sound investment decisions in 

response to these MACT and NSPS requirements. 

2. What is our final action on the other emission limits in the 

NSPS?

We did not propose changes to the other emissions limits in 

the NSPS, such as materials handling operations. We received 

one comment recommending that we promulgate NSPS limits for 

clinker storage piles, raw materials handling, and baghouse 

fall-out. Open clinker piles are being regulated as part of the 

NESHAP as previously discussed. Materials handling operations 
Page 133 of 456

are currently regulated under NESHAP. We believe baghouse fall 

out would be regulated as part of materials handling standards. 

3. What other changes are being promulgated? 

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 

language was appropriate because the NSPS only regulated PM, and 

the PM limits in the NSPS and NESHAP were identical. At 

proposal, where the proposed new source PM limits in the NSPS 

and NESHAP were different, we proposed to add 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 

source 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. 

This proposed language is still applicable even though in 

this final rule we are setting identical new source PM standards 

in the NSPS and NESHAP rule. For example, a cement kiln that is 

an existing source under NESHAP subject to the 0.04 lb/ton 

clinker emissions limit could potentially become modified under 

NSPS and also be subject to the 0.01 lb/ton clinker emissions 

limit. In addition, there is always a possibility that other 
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situation may occur where a source is subject to differing 

emission limits under NSPS and NESHAP as a result of rule 

changes. 

4. What are the final testing requirements under subpart F?

There are no PM, NOx or SO2 compliance testing requirements; 

compliance is based on the use of a continuous emissions monitor 

(see below).

5. What are the final monitoring requirements under subpart F? 

To demonstrate compliance with the PM emission limits, we 

are amending the monitoring requirements to require the 

installation and operation of a PM CEMS. The reason for this 

decision was previously discussed. Because this requirement is 

also part of the Portland Cement NESHAP, it will also apply to 

existing kilns currently subject to the NSPS. Consequently, 

affected facilities under this rule are not subject to an 

opacity standard to monitor compliance with the final PM 

standard. The PM CEMS must be installed and operated in 

accordance with the requirements of §60.63(g).

We are also adding monitoring requirements for all emission 

sources that are subject to the 10 percent opacity standard –

that is, emission sources other than the kiln and clinker 

cooler. We are requiring that they meet the monitoring 

requirements for these same emission points contained in the 
Page 135 of 456

Portland Cement NESHAP, 40 CFR part 63, subpart LLL in order to 

make the two rules consistent. 

Under the final amendments, compliance with the emission 

limits for NOx and SO2 are also determined using continuous 

emissions monitoring systems (CEMS). The requirements for the 

installation, operation, and calibration of each CEM, including 

minimum data requirements, are specified in the requirements in

§60.63(k) and (l). Under the final amendments, the owner or 

operator of kilns that elect to comply with the alternative SO2

emission limit of 90 percent reduction are required to 

continuously monitor SO2 emissions at the scrubber inlet as well 

as the outlet. These are the same requirements proposed. We 

received no comments on the NOx monitoring provisions. 

Commenters objected to the SO2 monitoring requirement for 

facilities that do not require SO2 controls, suggesting stack 

tests every five years instead. However, in these cases, it is 

possible that a source might change a raw material and 

significantly increase SO2 emissions beyond the standard. If 

monitoring is not in place, these excess emissions could be 

unchecked for five years before they were discovered. We 

believe the cost of the SO2 monitor ($56,000) is reasonable to 

prevent these excess emissions. These monitors are well 

established technology that are already installed on over 30 

cement kilns, including those without SO2 controls. 
Page 136 of 456

C. What is EPA‘s Sector-Based Approach?

Sector-based approaches are based on integrated assessments 

that consider multiple pollutants in a comprehensive and 

coordinated manner to manage emissions and CAA requirements. 

One of the many ways we can address sector-based approaches is 

by reviewing multiple regulatory programs together whenever 

possible. This approach essentially expands the technical 

analyses on costs and benefits of particular technologies, to 

consider the interactions of rules that regulate sources. The 

benefit of multi-pollutant and sector-based analyses and 

approaches include the ability to identify optimum strategies, 

considering feasibility, costs, and benefits across the 

different pollutant types while streamlining administrative and 

compliance complexities and reducing conflicting and redundant 

requirements, resulting in added certainty and easier 

implementation of control strategies for the sector under 

consideration. 

In order to benefit from a sector-based approach for the 

cement industry, EPA analyzed how the NESHAP under 

reconsideration relates to other regulatory requirements 

currently under review for Portland cement facilities. In this 

analysis we looked at how the different control requirements 

that result from these requirement interact, including the 

different regulatory deadlines and control equipment requirement 
Page 137 of 456

that result, the different reporting and recordkeeping 

requirements, and opportunities for States to account for 

reductions resulting for this rulemaking in their state 

implementation plans. The requirements analyzed affect HAP 

and/or criteria pollutant emissions from cement kilns and cover 

the NESHAP reconsideration, area source NESHAP, and the NSPS

revision and their collateral impacts on other programs such as 

New Source Review (NSR), Regional Haze and the National Ambient 

Air Quality Standards (NAAQS). 

As a result of the sector-based approach, this rulemaking 

will reduce conflicting and redundant requirements by setting 

the same PM emission limit requirement for both the Cement 

NESHAP and the Cement NSPS. Also the sector-based approach 

facilitated the streamlining of monitoring, record keeping and 

reporting requirements on both rules reducing administrative and 

compliance complexities associated with complying with both 

regulations. In addition, the sector-based approach promotes a 

comprehensive control strategy that maximizes the co-control of 

multiple regulated pollutants (i.e., mercury and HCl) while 

obtaining SO2 and PM2.5 emission reductions as co-benefits. These 

collateral SO2 and PM2.5 emission reductions may be considered for 

―netting‖ and ―offsets‖ purposes under the major NSR program or 

as credits that could help areas around the country with 

attainment of the SO2 or PM2.5 NAAQS 
Page 138 of 456

For more information on our sector‘s analyses, its benefits 

and interaction with NSR, NAAQS and Regional Haze please refer 

to the preamble of the proposal of this rule (74 FR 21159-61)

V. Responses to Major Comments

This section presents a summary of responses to major 

comments. A summary of the comments received and our responses 

to those comments may be found in Docket ID No. EPA-HQ-OAR-2007-

0877 for subpart F and Docket ID No. EPA-HQ-OAR-2002-0051 for 

subpart LLL.

A. What are the significant comments and responses on 40 CFR 

part 63, subpart LLL?

Comment: Many industry commenters (2830, 2832, 2836, 2841, 2844, 

2845, 2858, 2859, 2863, 2864, 2874, 2890, 2908, 2910, 2914, 

2915, 2916, and 2917) stated that setting MACT floors on a 

pollutant-by-pollutant basis violates the law and results in 

MACT floors that bear no relation to emission limits that are 

being achieved at the best performing existing sources. 

According to industry commenters, this method violates the plain 

language and intent of §112(d) of the Clean Air Act (CAA) and 

its effect is a MACT floor that reflects a standard that no one 

plant in existence currently achieves. Industry commenters 

2832, 2841, 2844, 2845, 2846, 2910, 2914, 2915, and 2916 stated 

that §112(d)‘s use of the terms best-performing and existing

clearly means that sources in a category or subcategory that are 
Page 139 of 456

used to set the MACT floor are to be real, not theoretical or 

hypothetical, sources (42 U.S.C. §7412(d), 2006 and Northeast 

Maryland Waste Disposal Authority, 358 F.3d at 954). They 

further contend that the phrase achieved in practice can only 

mean that Congress intended actual sources, performing under 

real-life conditions, to be the benchmark for determining the 

MACT floors. Furthermore, the language of the statute does not 

speak in terms of the best-performing source or sources for each 

listed pollutant or group of pollutants (42 U.S.C. §7412(d)). 

Rather, the focus is on the best existing source or sources for 

all pollutants, and what these sources truly can achieve on an 

overall basis. Industry commenters argue that EPA‘s pollutantby-pollutant methodology is also at odds with the legislative 

history underlying §112(d) (S. Rep. No. 228, 101st Cong., 1st 

Sess. 169, 1989). 

According to the industry commenters, the focus on overall 

performance is not surprising because in the 1990 CAA Amendments 

Congress abandoned §112‘s previous focus on individual pollutant 

standards, and adopted the technology-based multi-pollutant 

approach to regulating toxics in use under the Clean Water Act 

(CWA). See S. Rep. No. 228, 101st Cong., 1st Sess. 133-34 

(1989). Thus, if one source can achieve a firm degree of control 

for one pollutant but not for another, there may be no 

justification for including it in the set of sources from which 
Page 140 of 456

the floor is calculated (Tanners‘ Council of America v. Train, 

540 F.2d 1188, 1193 (4th Cir. 1976) deeming CWA effluent 

limitations guidelines not achievable where plants in EPA‘s 

database were capable of meeting the limitations for some, but 

not all, of the pollutant parameters).

Some industry commenters (2845, 2910) stated that EPA‘s 

previous use of a pollutant-by-pollutant analysis was based on 

authorities not applicable to the CAA. EPA attempted to defend 

its practice of establishing pollutant-by-pollutant MACT 

standards by citing Chemical Mfr. Ass‘n. v EPA, 870 F.2d 177, 

239 (1989), clarified 885 F.2d 253, 264 (5th Cir. 1989), cert. 

denied, 495 U.S. 910, (1990), a case where the Court held that, 

under the CWA, best available technology (BAT) referred to the 

single best-performing plant on a pollutant-by-pollutant basis.

According to industry commenters 2845 and 2910, EPA‘s 

reliance on Chemical Mfr. Ass‘n is misplaced as the CAA‘s 

procedure regarding the selection of MACT technologies differs 

on a textual basis from the CWA‘s procedure for identifying best 

available technology. Under the CWA, BAT standards are to be set 

based on the best practicable control technology currently 

available. 33 U.S.C. §1311(b)(1)(A)(i)(2006). This has led to 

pollutant-by-pollutant determinations. The CAA more narrowly 

limits the basis for MACT designation to what has been achieved 
Page 141 of 456

at existing sources, not what could be hypothetically achievable 

on a per-pollutant basis.

One industry commenter (2890) stated that EPA appears to be 

forgetting that the floor is only the first step in the process. 

Once EPA has established a floor based on physical sources, it 

is directed to go back and look at options beyond the floor. 

Those beyond the floor options would include the best control 

for each pollutant on every source. By correcting the floor 

approach, EPA would also correct the issue identified by Judge 

Williams in his concurring opinion to the Brick vacatur, where a 

floor that is designed to represent what has been achieved is 

more stringent than what would be deemed achievable under a 

MACT.

Response: We disagree with the commenters who object to setting 

MACT floors on a pollutant-by pollutant basis. Contrary to the 

commenters‘ suggestion, section 112 (d)(3) does not mandate a 

total facility approach. A reasonable interpretation of section 

112 (d)(3) is that MACT floors may be established on a HAP-byHAP basis, so that there can be different pools of best 

performers for each HAP. Indeed, as illustrated below, the 

total facility approach not only is not compelled by the 

statutory language but can lead to results so arbitrary that the 

approach may simply not be legally permissible. 
Page 142 of 456

Section 112 (d)(3) is ambiguous as to whether the MACT 

floor is to be based on the performance of an entire source or 

on the performance achieved in controlling particular HAP. 

Congress specified in section 112(d)(3) the minimum level of 

emission reduction that could satisfy the requirement to adopt 

MACT. For new sources, this floor level is to be "the emission 

control that is achieved in practice by the best controlled 

similar source.‖ For existing sources, the floor level is to be 

"the average emission limitation achieved by the best performing 

12 percent of the existing sources" for categories and 

subcategories with 30 or more sources, or "the average emission 

limitation achieved by the best performing 5 sources" for 

categories and subcategories with fewer than 30 sources. This 

language does not address whether floor levels can be 

established HAP-by-HAP or by any other means. The existing 

source MACT floor achieved by the average of the best performing 

12 percent can reasonably be read as referring to the source as 

a whole or to performance as to a particular HAP. The reference 

in the new source MACT floor provision to "emission control 

achieved by the best controlled similar source" can mean 

emission control as to a particular HAP or emission control 

achieved by a source as a whole.

 Industry commenters also stressed that section 112 (d) 

requires that floors be based on actual performance from real 
Page 143 of 456

facilities, pointing to such language as ―existing source‖, 

―best performing‖, and ―achieved in practice‖. EPA agrees that 

this language refers to sources‘ actual operation, but we repeat 

that the language says nothing about whether it is referring to 

performance as to individual HAP or to single facility‘s 

performance for all HAP. Industry commenters also said that 

Congress could have mandated a HAP-by-HAP result by using the 

phrase ―for each HAP‖ at appropriate points in section 112 (d). 

Doing so would have removed ambiguity from section 112 (d), but 

does not compel any inference that Congress was sub-silentio

mandating a different result when it left the provision 

ambiguous on this issue. The argument that MACT floors set HAPby-HAP are based on the performance of a hypothetical facility, 

so that the limitations are not based on those achieved in 

practice, just re-begs the question of whether section 112 

(d)(3) refers to whole facilities or individual HAP. All of the 

limitations in the floors in this rule of course reflect 

sources‘ actual performance and were achieved in practice. 

The reason EPA has long adopted the interpretation that the 

existing and new source MACT floors are to be applied on a HAPby-HAP basis are that a whole plant approach likely yields least 

common denominator floors – that is floors reflecting mediocre 

or no control, rather than performance which is the average of 

what best performers have achieved. See 61 FR at 173687 (April 
Page 144 of 456

19, 1996); 62 FR at 48363-64 (September 15, 1997) (same approach 

adopted under the very similar language of section 129 (a)(2)). 

For example, if the best performing 12 percent of facilities for 

HAP metals did not control organics as well as a different 12 

percent of facilities, the floor for organics and metals would 

end up not reflecting best performance. For new sources, not 

only would the floor reflect unoptimized control, but EPA would 

have to make some type of value judgment between control of 

organics and metals just to decide which source was best 

controlled. 37

Commenters provided no description of how their total 

facility approach would work in practice. Would a source that is 

a best performer for PM and worst for other HAP be in the pool? 

Would there be some overall summing of where the kiln fell for 

each pollutant? Would there have to be value judgments made 

among pollutants (is being a best performer for mercury worth 

 

37 Another industry commenter (2859) stated that it had three 

sources which were best performers for mercury and three other 

sources which were best performers for PM but that each would 

need to make upgrades for the pollutant not currently fully 

controlled. EPA views this as another least common denominator 

example whereby each of the floors would be diluted due to the 

coincidence that facilities are not optimizing control of all 

their emitted pollutants. See also Petitioners Brief in Medical 

Waste Institute et al. v. EPA, No. 09-1297 (D.C. Cir.) pointing 

out, in this context, that ―the best performers for some 

pollutants are the worst performers for others‖ (p. 34) and 

―[s]ome of the best performers for certain pollutants are among 

the worst performers for others.‖
Page 145 of 456

more than for PM in a ranking process)? EPA evaluated an 

approach whereby every kiln was ranked for performance for each 

HAP and the results were summed with the lowest overall score 

being the best performer, and next lowest the second best, etc. 

(among other things yielding a tie for best performer with no 

non-arbitrary way to break the tie). Using this approach, and 

with the three lowest ranked kilns as the average of the best 

performers, standards (after applying the UPL equation) would be 

approximately 65 lb/MM tons of clinker for mercury, 90 ppm for 

THC (nearly four fold increase), and 0.12 for PM (over an order 

of magnitude increase). All but one kiln in the data base 

already meets the THC standard, 21 of 89 kilns would meet the 

mercury limit, and 27 of 46 kilns have stack test measurements 

less than the 30-day value for PM. See memorandum, ―Total 

Facility Approach for Setting MACT Floors‖, August 6, 2010.

38 

These inflated values, and especially the drastically inflated 

THC and PM values, simply do not reflect best performance. 

 These types of results are at odds with Congress‘ purpose in 

adopting MACT floors. The central purpose of the amended air 

toxics provisions was to apply strict technology-based emission 

 

38 This example could have been more extreme. One of the ultrahigh mercury emitting sources is nearly a best performer for HCl 

(it is just outside the pool of three best performers). 

Inclusion as a best performer, under some methodologies, would 

have added these mercury emissions to the pool of  ̳best 

performers‘, even though, for mercury, performance is the worst. 
Page 146 of 456

controls on HAPs. See, e.g., H. Rep. No. 952, 101st Cong. 2d 

sess. 338. The floor's specific purpose was to assure that 

consideration of economic and other impacts not be used to "gut 

the standards. While costs are by no means irrelevant, they 

should by no means be the determining factors. There needs to be 

a minimum degree of control in relation to the control 

technologies that have already been attained by the best 

existing sources.‖ A Legislative History of the Clean Air Act 

Vol. II at 2897 (statement of Rep. Collins). An interpretation 

that the floor level of control must be limited by the 

performance of devices that only control some of these 

pollutants effectively ―guts the standards‖ by including worse 

performers in the averaging process, whereas EPA‘s 

interpretation promotes the evident Congressional objective of 

having the floor reflect the average performance of best 

performing sources. Since Congress has not spoken to the 

precise question at issue, and the Agency's interpretation 

effectuates statutory goals and policies in a reasonable manner, 

its interpretation must be upheld. See Chevron v. NRDC, 467 U.S. 

837 (1984).

39

 

39 Since industry commenters argued that the statute can only be 

read to allow floors to be determined on a single source basis, 

commenters offered no view of why their reading could be viewed 

as reasonable in light of the statute‘s goals and objectives. 

It is not evident how any statutory goal is promoted by an 

interpretation that allows floors to be determined in a manner 
Page 147 of 456

It is true that legislative history can sometimes be so 

clear as to give clear meaning to what is otherwise ambiguous 

statutory text. As just explained, EPA‘s HAP-by-HAP approach 

fulfills the evident statutory purpose and is supported by the 

most pertinent legislative history. A few industry commenters 

nonetheless indicated that a HAP-by-HAP approach is inconsistent 

with legislative history to section 112 (d), citing to page 169 

of the Senate Report. Since this Report was to a version of the 

bill which did not include a floor provision at all (much less 

the language at issue here), it is of no relevance. National 

Lime II, 233 F. 3d at 638.

Other industry commenters pointed out correctly that the 

section 112 (d) air toxic provisions were modeled on the 

technology-based control scheme for water toxics in the Clean 

Water Act. S. Rep. No. 228, 101st Cong. 2d sess. 133-34. 

However, a HAP-by-HAP approach to standard setting has actually 

been adopted and upheld under the Clean Water Act. Section 301 

(b) (2) (A) of the Clean Water Act requires plants to control 

discharges of toxic pollutants to a degree reflecting 

performance of ―best available technology economically 

achievable.‖ In Chemical Manufacturers Ass‘n v. EPA, 870 F. 2d 

 

likely to result in floors reflecting emissions from worst or 

mediocre performers.
Page 148 of 456

177, 238 (5th Cir. 1989) the Court held that this requirement 

could permissibly be applied on a pollutant-by-pollutant basis: 

The legislative history of the CWA indicates that the "best 

available technology" refers to the single best performing 

plant in an industrial field. The EPA urges that because 

the Act and the legislative history do not provide more 

particular guidance, it was free to determine the "best" 

plant on a pollutant-by-pollutant basis. The Supreme Court 

has stated that "it is by now commonplace that 'when faced 

with a problem of statutory construction, this Court shows 

great deference to the interpretation given the statute by 

the officers or agency charged with its administration.'" 

This Court defers to the EPA's interpretation of the Act. 

The EPA's interpretation of the Act is rational and is not 

precluded by the legislative history‖ (internal citations 

omitted). 

The Court reaffirmed its holding on this issue at 885 F. 253, 

264 (5th Cir. 1989).

 Industry commenters stated that the Clean Water Act 

requirement of Best Available Technology Economically Achievable 

and Best practicable Technology is not the same as the Clean Air 

Act‘s requirement of maximum achievable control technology. 

These distinctions do not seem pertinent to the issue at hand. 

Both statutes require technology-based performance to control 

all toxics discharged or emitted, and both require standards to 

be achievable. The legislative history to section 112 (d) makes 

clear that the CAA provisions are modeled after those in the 

Water Act (as industry commenters correctly noted). EPA does 

not see any more certainty in the CWA than in the Clean Air Act 

on this point and believes its interpretation that a pollutant-
Page 149 of 456

by-pollutant approach is justified is as reasonable under 

section 112 (d) (3) of the CAA as it is under section 301 (b) 

(2) of the Clean Water Act.40

 Industry commenters also noted that EPA retains the duty 

to investigate and, if justifiable, to adopt beyond the floor 

standards, so that potential least common denominator floors 

resulting from the whole facility approach would not have to 

―gut the standards.‖ That EPA may adopt more stringent 

standards based on what is ―achievable‖ after considering costs 

 

40 One industry commenter cited Tanners‘ Council of America v. 

Train, 540 F. 2d 1188, 1193 (4th Cir. 1976) for the proposition 

that technology-based effluent limitation guidelines under the 

Clean Water Act are not considered achievable ―where plants in 

EPA‘s database were  ̳capable of meeting the limitation for some, 

but not all, of the pollutant parameters‘‖. Tanners‘ Council

involved a situation where EPA established standards for one 

source category based on a transfer of performance information 

from a different, unrelated source category. 540 F. 2d at 1192-

93. Since the wastewater from the category from which the 

limits were transferred was easier to treat than tannery 

wastewater, the court was skeptical of EPA‘s undocumented 

assertions that the transfer of performance data (with certain 

upward adjustments) was permissible. Id. None of these 

circumstances apply here. EPA is not transferring performance 

from another category, but basing limits on documented 

performance of cement kilns. In addition, as noted in earlier 

preamble text, all of the kilns in the pool of best performers 

for each HAP is meeting the limit for that HAP, a strong showing 

of technical feasibility and technical achievability. Cf. CPC 

International v. Train, 540 F. 2d 1329, 1333 (8th Cir. 1976); 

American Meat Inst. v. EPA, 526 F. 2d 442, 458, 459 (7th Cir. 

1975). Further, as discussed in the final part of this comment 

response, EPA has closely examined and is unaware of any 

situation whereby optimized performance for one HAP interferes 

with or otherwise precludes or impedes optimized performance for 

another.
Page 150 of 456

and other factors is irrelevant to how EPA is required to set 

MACT floors. MACT floors must be based on the emission 

limitation achieved by the best performing 12 percent of 

existing sources, and, for new sources, on the level achieved by 

the best controlled similar source, and EPA must make this 

determination without consideration of cost. At best, standards 

reflecting a beyond-the-floor level of performance will have to 

be cost-justified; at worst, standards will remain at levels 

reflecting mediocre performance. Under either scenario, 

Congress‘ purpose in requiring floors is compromised.

 EPA notes, however, that if optimized performance for 

different HAPs is not technologically possible due to mutually 

inconsistent control technologies (for example, metals

performance decreases if organics reduction is optimized), then 

this would have to be taken into account by EPA in establishing 

a floor (or floors). The Senate Report indicates that if certain 

types of otherwise needed controls are mutually exclusive, EPA

is to optimize the part of the standard providing the most 

environmental protection. S. Rep. No. 228, 101st Cong. 1st sess. 

168 (although, as noted, the bill accompanying this Report 

contained no floor provisions). It should be emphasized, 

however, that "the fact that no plant has been shown to be able 

to meet all of the limitations does not demonstrate that all the 

limitations are not achievable." Chemical Manufacturers 
Page 151 of 456

Association v. EPA, 885 F. 2d at 264 (upholding technology-based 

standards based on best performance for each pollutant by 

different plants, where at least one plant met each of the 

limitations but no single plant met all of them).

 All available data for cement kilns indicate that there is 

no technical problem achieving the floor levels for each HAP 

simultaneously, using the MACT floor technology. For most 

kilns, compliance with the mercury limits will be accomplished 

using activated carbon injection followed by a second PM control 

consisting of a fabric filter. There is no technical impediment 

to using this same system for control of THC (or organic HAP). 

Note that the ACI system would have to be installed downstream 

of the existing PM control, therefore there would be no effect 

on the cement kiln dust collected in the existing PM control. 

One industry commenter claimed that carbon is not effective on 

mercury and THC at the same time. However, we see no basis for 

that statement as long as the correct type of carbon is used. 

Another industry commenter claimed ACI increases dioxin 

emissions. Considering the fact that ACI can actually be used 

to remove dioxins from kiln exhaust gas, we see no basis for 

that statement either. 

After the ACI system, a wet scrubber can be used for HCl 

control. We would expect the wet scrubber to be the downstream 

control because it creates a moisture laden exhaust that would 
Page 152 of 456

require reheating to then apply ACI. Again, there is no 

technical impediment to adding a wet scrubber after the ACI 

system, and the two control devices should not interfere with 

each other‘s performance. If the facility required an RTO to 

meet the THC limit, the RTO would be installed downstream of the 

wet scrubber in order to protect the RTO from any acid gases in 

the kiln exhaust. The wet scrubber/RTO combination has been 

demonstrated in cement kiln applications. 

In order to meet the PM standard a facility could choose to 

modify their existing PM control to meet the new limit, or 

design the baghouse downstream of the ACI injection point to 

meet the PM limit. 

Though we have described some fairly complicated control 

scenarios, there are simpler applications of control technology 

that would likely be utilized successfully. One example would 

be simultaneous injection of alkaline materials (lime or sodium 

compounds) and activated carbon downstream of the existing PM 

control device followed by collection with a fabric filter. 

This type of injection scheme would potentially control acid 

gases (HCl and SO2), THC (or organic HAP) mercury, and PM.

Industry commenters made much of the fact that no single 

facility is presently achieving all of the HAP limits proposed. 

But this only shows that plants will need to reduce their 
Page 153 of 456

emissions of certain HAP to meet standards reflecting average of 

best industry performers for that HAP. 

Impacts of pollutant-by-pollutant approach

Comment: Industry commenters 2831, 2844, 2845, and 2874 stated 

that in evaluating the economic cost of achieving emission 

reductions, looking at one plant‘s emission control of only one 

pollutant to the exclusion of all other emission controls 

produces a disjointed view of cost implications and compliance 

feasibility. While an individual MACT floor for one pollutant 

might not appear cost-prohibitive, when combined with all of the 

other MACT floors for other pollutants, the total cost 

implications could become especially onerous. While the CAA was 

authored with the intent of reducing air pollution, Congress did 

not intend to disrupt the productive capacity of the United 

States through the promulgation of economically unachievable 

standards. 42 U.S.C. §7401(b)(1)(2006). By setting MACT floors 

individually and ignoring the collective cost implications of 

the entire NESHAP, EPA would effectively disregard the CAA‘s 

requirement that air pollution control be advanced while 

promoting the nation‘s productive capacity. Id.

Response: EPA is forbidden by law from considering costs in 

determining MACT floors. NRDC v. EPA, 489 F. 3d 1364, 1376 

(D.C. Cir. 2007); National Lime, 233 F. 3d at 640. Although one 

of the overall goals of the Act is to protect and enhance the 
Page 154 of 456

quality of the Nation‘s air and resources so as to promote the 

public health and welfare and the productive capacity of the 

population,‖ CAA section 101 (b) (1), this overall goal does not 

somehow authorize EPA to adopt floors that either consider costs 

(overall or otherwise) or to base floors on other than what best 

performers achieve.

2.3.3 Lowest Emitters as Best Performers

Comment: One industry commenter (2834) stated that the Brick 

MACT ruling of the D.C. Circuit Court reinforces earlier 

holdings in National Lime Association vs. EPA. The Court again 

held that floors are to be based on the emission level actually 

achieved by the best performers (those with lowest emission 

levels), not the emission level achievable by all sources.

Response: In this rule, EPA is choosing as best performers 

those sources with lowest emissions of each HAP, on a normalized 

basis, with sources‘ variability taken into account in assessing 

which had the lowest emissions. 

Comment: Many industry commenters (2841, 2844, 2845, 2846, 

2858, and 2914) stated that EPA established its proposed floors 

equating best performing sources with those that have the lowest 

emissions for particular HAPs even though there are other ways 

to measure performance and, in some cases, other methodologies 

may comply with the statute where the "lowest emitter" approach 

does not. Industry commenter 2845 noted that equating best 
Page 155 of 456

performer with lowest emitter contravenes a Congressional 

directive that, in developing MACT standards, EPA cannot require 

substitution of raw materials in mineral processing industries, 

such as cement manufacturing, quoting the Joint Explanatory 

Statement of the Committee of Conference for the 1990 CAA 

Amendments stated: For categories and subcategories of sources 

of [HAPs] engaged in mining, extraction, beneficiation, and 

processing of nonferrous ores, concentrates, minerals, metals, 

and related in-process materials, the Administrator shall not 

consider the substitution of, or other changes in, metal- or 

mineral-bearing raw materials that are used as feedstocks or 

material inputs . . . in setting emission standards, work 

practice standards, operating standards or other prohibitions or 

requirements or limitations under this section for such 

categories and subcategories. H.R. Rep. No. 101-952, at 339 

(1990). According to the industry commenters, enormous amounts 

of limestone are fed into a kiln to manufacture clinker, and it 

is cost-prohibitive to import limestone from further away. If 

the plant‘s quarry contains limestone with high concentrations 

of mercury or high concentrations of organics, the kilns will 

emit more mercury or THC and potentially more organic HAPs. 

Because limestone with high mercury or organic emissions will 

result in higher HAP emissions, and it is not cost-effective to 

import limestone from far away, equating the lowest emitters 
Page 156 of 456

with the best performing sources makes no sense in the context 

of cement facilities. It also would be squarely in opposition to 

the Joint Explanatory Statement.

Response: The industry commenter is citing to the ―Joint 

Explanatory Statement" that accompanied the Conference Committee 

Report to the 1990 Clean Air Act Amendments. This legislative 

history is of limited utility here. As explained at 353 F. 3d 

388: ―The Joint Explanatory Statement describes how the 

differences between the Senate and House were resolved in the 

Conference Committee.... The Joint Explanatory Statement may be 

helpful in determining Congress's intent, but does not carry the 

same weight as the Conference Committee Report itself.‖ See id. 

at 236-37. If there were some ambiguity in the statute, the 

Joint Conference Committee Report could shed some light on 

Congress‘ intent, but there is no exception to section 112 

(d)(2) (A)‘s requirement that EPA consider ―substitution of 

materials‖ for each source category. Thus, the statement cannot 

be read to negate the express statutory command that MACT is to 

be based on, among other things, measures, processes, or systems 

which reduce the volume of pollutant emissions through 

substitution of materials or other process modifications. 

Indeed, EPA‘s attempts to identify best performers by ignoring 

the contribution of raw material inputs have been soundly 

rejected. Brick MACT, 489 F. 3d at 882-883. In fact, brick and 
Page 157 of 456

ceramic production, like Portland cement production, involves 

extraction of mined material from a quarry located proximate to 

the production facility because transport of raw material over 

long distances is ―infeasible‖. 489 F. 3d at 879. The language 

from the Joint Explanatory Statement no more allows EPA to

ignore raw material contribution to Portland cement plants‘ HAP 

emissions than it did raw material HAP contributions to brick 

and ceramic plants‘ HAP emissions.

Comment: Industry commenter 2844 stated that EPA could 

interpret §112(d)(3) as Brick MACT appears to do, as one unitary 

concept meaning sources with the lowest emission levels, or EPA 

can interpret it as a more complex concept that EPA may 

determine the emission control (using any of the various 

definitions in the CAA) that sources have achieved in practice 

(as estimated by reasonably predictive variability factors) and 

rank them according to their relative emissions levels (i.e., a 

quantitative measure of achievement). Having done so, the Agency 

can then evaluate each of the lowest emitters in terms of 

whether they meet the Agency‘s criteria for best controlled 

similar source. With regard to best controlled, EPA may evaluate 

this from a purely quantitative angle (lowest emissions) or from 

more qualitative aspects (reduction efficiency, environmental 

and health (or cross-media) impacts, cost-effectiveness of 
Page 158 of 456

reductions achieved, impacts on other HAP or pollutant 

emissions, and so on.

Industry commenter 2845 provided several examples of 

judicial MACT decisions endorsing a technology approach to 

setting the standards, in which EPA selected the best performing 

sources based on the relative performance of air pollution 

control technology.

Industry commenter 2844 stated that EPA also has the 

discretion to define best performers as sources other than those 

with the lowest achieved emission levels. In the current 

proposal, the many difficulties associated with evaluating the 

impact of HAP content in the raw material inputs to mercury 

emission control and other factors could support a decision by 

the agency to establish a standard based on efficiency (i.e., a 

percent reduction standard) if not for the source category as a 

whole, then such a standard might be established for a 

particular subcategory as relevant, or as an alternative 

compliance strategy. EPA‘s discretion is sufficiently broad to 

encompass many reasonable decisions identifying and estimating 

the emission control of best performing sources on bases other 

than lowest emissions data, assuming the floor for the standard 

is based on a reasonable methodology estimating the percent 

reduction achieved in practice by the best performing sources 

under the reasonably foreseeable worst operating conditions.
Page 159 of 456

Industry commenter 2844 stated that before EPA can determine a 

floor, EPA must define the following terms in regard to the 

selection of a best performer for new sources: Emission control; 

Achieved in practice; Best controlled; and Similar source.

To set the floor for existing sources, the industry commenter 

stated that EPA should define the following terms: Average 

emission limitation; Achieved; and Best performing.

Response: EPA must make determinations in each standard as to 

each of these terms and has done so here. In this rule, EPA is 

determining that the best controlled similar source is the 

source with the lowest emissions of the HAP in question on a 

normalized basis (for mercury and PM), and on a concentration 

basis (for THC and HCl) considering variability in determining 

both which source is best controlled and in estimating its 

achieved performance. EPA is adopting the same approach for 

existing sources in determining which are the 12 percent of best 

performing sources and the performance they achieve. This 

approach accounts for all HAP inputs and outputs (i.e., accounts 

for HAP in all raw material and feed inputs as well as all 

emission controls), and is consistent with the case law.

With regard to the comment stating that the standard could 

be expressed as a per cent reduction, the industry commenter did 

not explain how this can be done without negating the 

contribution of HAPs in feed and fuel input into plant 
Page 160 of 456

performance. Most particularly, for HAP which are uncontrolled, 

mercury being the chief example in this rule, there is no 

removal efficiency to evaluate. Moreover, even for HAP which 

are controlled, plants with higher removal efficiencies may also 

be the highest emitters if the levels of the inputs to the 

control device is high. For these reasons, EPA is not 

evaluating best performers based on removal efficiencies in this 

rule.

Comment: Industry commenters 2832, 2846, and 2890 stated that 

rather than selecting sources with the lowest emissions for 

particular HAP as best performing sources, EPA could use the 

relative performance of air pollution control technology to 

select the best performing sources, applying the best reasonable 

method for determining best-performers, which does not 

necessarily have to equate to lowest emissions. 

Response: EPA discussed this issue at some length at proposal. 

See 74 FR at 21149. The problem with equating best performance 

with performance of pollution control alone is that it ignores 

the contribution of raw materials and fuels to HAP emissions. 

Basing standards exclusively on performance of control 

technology is legally permissible when the control technology is 

the sole factor influencing performance, which is not the case 

here. National Lime, 233 F. 3d at 633-34. EPA thus is not 
Page 161 of 456

adopting these industry commenters‘ approach. See previous 

response as well.

Comment: Several industry commenters (2845, 2846, 2874, and 

2915) stated that EPA is proposing to calculate MACT floors by 

averaging the top 12 percent of sources for which CEMS data are 

available (even if that amounts to less than 30 sources), rather 

than by considering the top 12 percent of sources for which EPA 

has emissions information. As a result, EPA is proposing to 

establish the MACT floor based on data from only 2 sources. The 

industry commenters stated that CAA §112(d) obligates EPA to set 

the MACT floor looking at no fewer than 5 sources, recognizing 

the value of relying on the maximum amount of data available. 

Industry commenter 2841 stated that the use of a minimum of five 

facilities should be adopted in the establishment of THC 

standards as well as the other standards in this proposed 

regulation. The establishment of requirements based on a small 

amount of data would run counter to the intent of the CAA in 

utilizing data that is truly representative of the bestperforming facilities throughout an entire industry.

Industry commenter 2841 stated that in previous MACT 

rulemakings, EPA used the five best performing facilities if the 

number of facilities was less than 30. Consistent with these 

prior rulemakings, the industry commenter stated that this 

approach should be used for this proposed Portland Cement NESHAP 
Page 162 of 456

rule and that EPA needs additional data points in order to 

appropriately set limits for the industry as a whole.

Response: EPA believes that it has discretion to use the data 

which most accurately measure sources‘ performance, which for 

THC case are data obtained from CEM-equipped sources. EPA also 

believes that it has a reasoned technical basis for not 

combining CEMS data with non-CEM data, since this would be a 

classic apples-to-oranges comparison due to the difference in 

measuring times and methods. EPA does not agree that section 

112 (d)(3) mandates a minimum of 5 sources in all instances, 

notwithstanding the incongruity of having less data to establish 

floors for larger source categories than is mandated for smaller 

ones. The literal language of the provision appears to compel 

this result.

Comment: One environmental advocacy group commenter (2898) 

supported EPA‘s decision to not rank best performers based on 

their relative mercury removal efficiency. Relying on mercury 

removal efficiency in setting the MACT floor for the Portland 

cement manufacturing industry would downplay the role of HAP 

inputs on emissions. EPA characterizes Brick MACT‘s statement 

that best performers are those emitting the least HAP as 

appearing arguably in dicta. However, the Brick MACT Court 

itself characterizes the statement as the holding of the Cement 

Kiln case. Brick MACT, 479 F.3d at 880 (relying on Cement Kiln‘s 
Page 163 of 456

holding that §7412(d)(3) requires floors based on the emission 

level actually achieved by the best performers or those with the 

lowest emission levels). The proposed alternative of setting the 

MACT floor on the basis of percentage of emission reduction 

achieved by sources would minimize, if not eliminate, the 

consideration of cleaner inputs in setting MACT floors, as EPA 

acknowledges, and is therefore contrary to statutory dictates 

and case law.

Response: EPA agrees that the chief legal issue with a percent 

reduction approach for expressing floors is that it undervalues 

the role of HAP inputs. EPA is not adopting that approach in 

this rulemaking.

Comment: Several industry trade association commenters (2831 

and 2901) stated that EPA retains considerable discretion on how 

to set MACT floors. The commenters supported the Agency‘s 

authority to set floor standards based on control efficiency, or 

any method as long as their method reasonably estimates the 

performance of the relevant best performing plants. There is 

nothing in the Court‘s decisions that requires EPA to use the 

straight-emissions approach favored in this rule. The commenter 

stated that the Court has expressly decided that a straight 

emissions or arithmetical methodology is not required. EPA‘s 

technology based approach that estimated performance rather than 

deriving the standards through an arithmetic-straight emissions 
Page 164 of 456

approach is supported by the Courts, as long as it results in a 

reasonable estimate of the performance of the best controlled 

units. According to the commenter (2901), Brick MACT does not 

endorse a straight emissions approach; nor could it. To do so 

would mean that the Brick MACT Court was overturning the Chevron 

step one holding in Sierra Club and National Lime II, something 

that it cannot do.

Response: EPA is adopting the straight emissions (so-called) 

approach in this rulemaking and believes that the approach is 

permissible under the statue and case law. Commenters also did 

not convincingly address the issue of how the alternative 

approaches they mention account for HAP inputs. Moreover, 

Sierra Club and National Lime II make clear that a straight 

emissions approach may not be mandated under the language of the 

statute, but also make clear that there must be a reasoned basis 

for estimating which performers are best. National Lime II, and 

later Brick MACT further make clear that contribution of HAP 

inputs in raw materials and fuels must be accounted for in 

making best performer determinations. See 233 F. 3d at 634, 639; 

479 F. 3d at 882-83. Each panel viewed these holdings as 

consistent with the Chevron analysis in Sierra Club. 233 F. 3d 

at 631-32, 633-34; 479 F. 3d at 878. 

Comment: One industry commenter (2844) stated that the CAA 

requires that lawfully promulgated NESHAP standards must be 
Page 165 of 456

achievable. Section 112(d)(2) of the Act requires EPA to 

establish emission standards for HAPs that require the maximum 

degree of reduction in emissions taking into consideration the 

cost of the emission reduction and non-air quality health and 

environmental impacts and energy requirements, that the EPA 

Administrator determines is achievable for new or existing 

sources. Further, House Rep. 101-490, Part 1 (328) stated that 

―The Committee expects MACT to be meaningful, so that MACT will 

require substantial reductions in emissions from uncontrolled 

levels. However, MACT is not intended to require unsafe control 

measures, or to drive sources to the brink of shutdown.‖ The 

commenter noted that the proposed Portland cement proposed 

NESHAP standards do not comply with §112‘s achievability 

requirements.

Response: The industry commenter refers to legislative history 

to versions of the 1990 amendments which did not include floor 

requirements, so it is not directly applicable in interpreting 

the enacted provisions. Moreover, as held repeatedly by the 

D.C. Circuit, the ―achievability‖ requirement in section 112 

(d)(2) does not alter the minimum level of stringency 

requirements mandated by section 112 (d)(3)‘s requirements. 

See, e.g., Cement Kiln Recycling Coalition, 255 F. 3d at 861-62.

Comment: Industry commenter 2844 stated that EPA‘s conclusion 

that §112(d)(3) and/or Brick MACT requires or even permits the 
Page 166 of 456

Agency to ignore the achievability requirements of §112(d)(2) is 

an unreasonable reading of the statute and of Brick MACT. The 

Agency retains more than sufficient discretion to devise NESHAP 

standards that successfully bridge the tension between achieved 

and achievable in §112‘s standard-setting provisions by 

appropriately using both subcategorization and variability 

methodologies.

Response: EPA believes that variability needs to be assessed in 

order to accurately measure both which performers are best and 

what their performance is. However, authority to subcategorize 

is discretionary and need not be exercised where there are 

rational grounds not to do so, such as not authorizing emissions 

of large amounts of a dangerous neurotoxin. See also previous 

response.

Comment: Industry commenter 2844 stated that EPA‘s floor 

setting methodology does not comply with three of Brick MACT‘s

requirements: Floors must be based on emissions achieved in 

practice by best-performing sources; EPA‘s use of variability 

factors and methodologies to adjust reported emissions data must 

be based on demonstrated relationships, so that the floor 

setting methodology serves to reasonably estimate or predict the 

performance of the best performing sources; and EPA must 

consider the impact of nontechnology factors, such as raw 

material and fuel inputs, on a source‘s emission control levels.
Page 167 of 456

Industry commenter 2844 stated that in the Portland cement 

proposal, EPA set MACT floor levels that reflect the specific 

conditions at the time the data were generated and do not 

include any of the operational variability. The commenter 

suggests that EPA must look beyond its snap shots of performance 

to make a reasoned evaluation and estimation of all operating 

conditions and factors that might impact the level of actual 

emissions from those kilns in practice, and adjust their 

reported short term test data appropriately. EPA can and should 

adjust raw emissions results to estimate sources‘ achieved 

emissions levels when setting MACT floors and standards. Since 

Brick MACT, EPA‘s methodology now must be able to reasonably 

estimate the impacts of variability associated with both 

technological and nontechnological factors over the full range 

of circumstances. 

Response: EPA disagrees that it has based the floors for any of 

the HAP on snapshot levels of performance and has not accounted 

for potential variability in sources‘ performance. Each of the 

floors reflects a reasonable estimate of what the best 

performing sources (or source) will achieve over time. Also, 

each of the floors considers the impact of non-technology 

factors, notably HAP inputs in raw materials and fuels, on the 

source‘s emissions. 
Page 168 of 456

Specifically, for mercury the standard reflects 30 days of 

data for all mercury inputs, reasonable estimates of control 

device performance (for the few controlled sources), plus a 

reasonable statistical methodology to account for variability 

(including variability of mercury content of kiln inputs). EPA 

also used a pooled variability factor (pooling variability for 

all kilns in the MACT pool), which increased variability 

estimates. Where commenters provided data showing that kilns‘ 

performance was underestimated because different inputs were 

used outside the sampling period, EPA adjusted those emissions 

estimates. EPA also used data on variability of kilns quarrying 

limestone from the same geologic formation as two of the best 

performing kilns to estimate intra-quarry variability of those 

two best performing kilns, and further applied this variability 

as part of the pooled variability. See IV.A.1.c of this

preamble and 74 FR at 21142-44. 

The standard for THC reflects hundreds of observations 

gathered continuously over time using a CEMS yielding a data set 

from which variability can be calculated directly. See IV.A.1.d

of this preamble. 

The floors for HCl are set at the minimum reliable 

quantification level, which is a factor of three above the 

actual measured levels, and are averaged over 30 days as well. 

EPA believes this fully accounts for performance variability.
Page 169 of 456

Floors for PM are based on multiple stack measurements 

which have been adjusted by reasonable statistical methodologies 

to account for variability. See IV.A.1.f of this preamble, 

responding to the argument that measurement by means of a CEM 

makes the standard more stringent. Moreover, the PM standard 

reflects performance of fabric filters with membrane bags, which 

are known to perform independent of inputs and to have 

relatively small operating variability. 72 FR at 54879 (Sept. 

27, 2007); 70 FR at 59449 ((Oct. 12, 2005). 

Consequently, for each HAP, EPA is assessing sources‘ 

performance over time in a reasonable manner and is not ignoring 

their operating variability.

Comment: Industry commenter 2844 also stated that EPA adopted a 

floor setting methodology that is based on using lowest reported 

emission results with minimal variability adjustments to 

estimate emission control achieved in practice by best 

performing sources. EPA considered test-to-test variability, but 

did not consider the inherent variability due to raw materials, 

product mix, fuels, operating conditions and plant types. The 

industry commenter stated that EPA has not evaluated or 

validated whether its methodology accurately estimates emissions 

control achieved in real world circumstances at sources.

Response: This industry comment is inaccurate on a number of 

counts. First, the statistical methodology used to estimate 
Page 170 of 456

variability depends on the distribution of data to which the 

formula is applied. Any variation in that data – be it due to 

differences in raw material concentration, fuel composition, or 

device operation – is thereby accounted for. Indeed, the data 

base for mercury consists virtually entirely of raw material and 

fuel mercury levels from which emissions are projected on a 

worst case, mass balance basis (since virtually no kiln controls 

its mercury emissions). Consequently, EPA‘s methodology does 

evaluate variability of inputs as well as product mix, fuels, 

operating conditions, and does not just evaluate control device 

operating variability as the commenter maintains. Second, for 

mercury and THC, EPA gathered data over time, as explained in 

the preamble and in the previous response. Third, for mercury, 

industry had ample opportunity to provide longer term sampling 

data and (with a few exceptions, which EPA evaluated and 

accepted) did not do so. Fourth, use of a pooled variability 

factor (which for mercury includes the reasonably estimated 

long-term intra-quarry variability of the two best performers 

extrapolated to all other sources in the MACT pool) further 

accounts for long term variability.

Comment: Industry commenter 2844 stated that EPA cannot 

evaluate floors using methodologies that focus exclusively on 

technology if the resulting standards do not reflect actual 

average limitation[s] achieved (Brick MACT, 479 F.3d at 882). 
Page 171 of 456

The industry commenter concludes that Brick MACT requires EPA to 

address the role of non-technological factors that impact 

emissions in setting floors and EPA must develop a methodology 

that accurately estimates the actual emissions achieved in 

practice by the best performing sources under a variety of 

operating conditions, taking into consideration testing and 

technological and non-technological variability. As proof that 

EPA failed to properly account for sources‘ variability in 

setting the standards, the industry commenter (and industry 

commenter 2845) included a chart purporting to demonstrate that 

the kilns comprising the pool of best performers for each HAP 

could not themselves meet the proposed standard. 

Response: EPA believes that its methodology reasonably estimates 

the variability of the best performing sources, taking into 

account both technological (emission control device) and nontechnological (varying inputs) variability. EPA disagrees that 

the record shows that the kilns comprising the MACT pool for 

each floor cannot themselves meet the promulgated standards (see 

previous response). In fact, for each pollutant, the record 

indicates that every kiln in the MACT pool (not just the kilns 

below the average of the best performers) would be in 

compliance. See section IV.A.1.b above.

Comment: One industry commenter (2845) stated that case law and 

policy dictate that EPA must consider variability in 
Page 172 of 456

establishing MACT standards, and the approach used by EPA in 

Prevention of Significant Deterioration (PSD) permitting should 

also apply in establishing MACT standards. To evaluate the 

emission limits achieved by existing sources, EPA is required to 

develop methodologies for estimating the variability associated 

with all factors that impact a source‘s emissions, including 

process, operational and non-technological variables (see Nat‘l 

Lime Ass‘n v. EPA, 627 F.2d 416, 443, D.C. Cir. 1980). While 

Courts have affirmed EPA‘s authority to choose a methodology 

designed to estimate emissions in setting the MACT floor, the 

Courts have also made clear that EPA‘s method must allow a 

reasonable inference as to the performance of the top 12 percent 

of units (Cement Kiln Recycling Coalition v. EPA, 255 F.3d 855, 

862 (D.C. Cir. 2001) (citing Sierra Club v. EPA, 167 F.3d 658, 

663, D.C. Cir. 1999). Accordingly, the Court of Appeals for the 

D.C. Circuit has stated that EPA must show not only that it 

believes its methodology provides an accurate picture of the 

relevant sources' actual performance, but also why its 

methodology yields the required estimate (Cement Kiln Recycling 

Coalition, 255 F.3d at 862).

Response: EPA agrees that sources‘ variability should be 

accounted for both in determining which sources are best 

performers and what their achieved performance is. EPA also 

believes that it has reasonably accounted for sources‘ 
Page 173 of 456

variability here, including both variability in inputs and 

operating variability.

Comment: Industry commenters 2844, 2845, and 2916 objected to 

EPA‘s interpretation of CAA Sections 112(d)(2) and 112(d)(3) and 

the Brick MACT opinion (Industry commenter 2845 provided a white 

paper as an appendix to their comments for the HWIMI MACT 

proposal, dated December 01, 2008.). The paper, titled 

―Implications of the Brick MACT Decision on EPA‘s Discretion in 

Setting MACT Floors,‖ discusses variability at some length. The 

paper‘s main points were:

 The Agency has chosen to focus on setting MACT floors based 

on lowest emitting sources derived from limited test 

results that are not appropriately adjusted to account for 

stack test variability. 

 The Brick MACT decision holds that EPA must base MACT 

floors on achieved emissions control rather than control 

technology, but it does not require EPA to ignore 

operational variability in determining those floors. 

Variability methodologies must reasonably estimate or 

predict emissions or variability through a demonstrated 

relationship between the data used and the performance 

intended to be estimated. Non-technological factors (i.e.,

raw materials and fuel) must be considered in determining 
Page 174 of 456

emission control achieved by best performers. It is within 

EPA‘s discretion to define the best performing sources. 

 EPA should estimate variability in determining achieved 

emissions. The Agency can and must seek appropriate data 

from regulated entities and other stakeholders, and to 

develop appropriate fact-based estimating methodologies on 

the data available.

Response: EPA largely agrees with these general points and 

believes that it has adhered to these concepts in the final 

rule. EPA has also implored, and in many instances, compelled 

(through section 114 letters) industry to provide additional 

data to better gauge sources‘ performance. 

Comment: A number of commenters including 2844 and 2845 argued 

that EPA should use an Upper Tolerance limit (UTL) rather than 

Upper Predictive Limit (UPL) statistical methodology to assess 

variability. 

Response: EPA disagrees. An Upper Tolerance Limit is ordinarily 

utilized for sparse data sets (such as a single data points) and 

is intended to assure that predicted values are lower than a 

single highest observation. This methodology is intended to 

produce values that do not underestimate variability but for 

this reason tends to produce inflated predictions when applied 

to data sets containing multiple observations, which is the case 

for the MACT pools for each HAP in this rulemaking. This 
Page 175 of 456

methodology would therefore overestimate performers‘ variability 

as applied in this rulemaking and EPA is therefore not utilizing 

it. In addition, based on documented conversations with 

representatives of these commenters after proposal, EPA 

understands that they no longer regard use of UTL statistical 

methodology as appropriate here.

Comment: Several industry commenters (2832 and 2859) opposed the 

approach taken by EPA in its beyond-the-floor MACT analysis. 

Among other things, EPA failed to consider the creation of 

incremental greenhouse gas emissions associated with the 

construction, installation and operation of new emissions 

control equipment, and the minimal incremental environmental 

benefit associated with those controls. Also, EPA failed to 

consider the cost of carbon credit purchases by the industry.

Response: In all cases we declined to adopt beyond-the-floor 

standards based on consideration of costs, technical 

feasibility, and consideration of nonair environmental impacts.

Evaluating other disbenefits for an option already rejected 

would have no purpose. 

Comment: Many industry commenters (2830, 2845, 2846, 2855, 2858, 

2859, 2879, 2887, and 2890) stated that CEMS are not a proven 

technology and should not be required to determine compliance. 

Industry commenters 2588, 2844, 2845, 2846, 2858, and 2890 

stated that EPA has no data showing that mercury CEMS are 
Page 176 of 456

feasible on cement kilns and that emissions from cement kilns 

will likely be outside of the range of the current CEMS 

technology. The industry commenters stated that EPA must 

evaluate mercury CEMS through long-term field trials at cement 

plants in accordance with the proposed performance 

specifications and quality assurance procedures before imposing 

this regulatory requirement. The industry commenters proposed a 

mass-balance approach for monitoring, which is accurate and was 

used by EPA in setting the mercury standard.

Industry commenter 2855 stated that mercury sorbent trap 

monitoring systems have not been evaluated through long term 

field trials at cement plants in the United States (U.S.) in 

accordance with the proposed performance specifications and 

quality assurance procedures, so the reliability and performance 

of these measurement systems and the adequacy of the technical 

specifications cannot be determined. 

Industry commenters 2855 and 2900 disagreed with EPA‘s 

interpretation of the operating experience with mercury CEMS in 

Germany. The industry commenters stated that mercury CEMS are 

inaccurate and difficult to maintain. Further, mercury CEMS 

operating in Germany are subject to monitoring regulations that 

are different than the U.S. regulations and are used in a 

different regulatory context than that proposed by EPA. The 

monitors used in Germany, or those available from other European 
Page 177 of 456

or Asian manufacturers were not able to demonstrate acceptable 

performance in the Electric Power Research Institute (EPRI) 

Trimble County Mercury CEMS study. 

Industry commenter 2855 stated that there is no legitimate 

technical basis on which to establish detailed performance 

specifications or quality assurance (QA) requirements for these 

CEMS. There is no legitimate technical basis to conclude that 

these CEMS could meet such requirements over any extended period 

when installed and operated at a cement plant. The industry 

commenter recommended that EPA evaluate the performance of 

mercury CEMS at cement kiln systems and acquire the information 

necessary to serve as the basis for technical specifications and 

requirements. After such information is available and analyzed, 

EPA should re-propose appropriate and demonstrated performance 

specifications and quality assurance procedures for mercury CEMS 

to monitor kiln and kiln/in-line raw mill mercury emissions. 

Industry commenter 2855 disagreed with EPA‘s interpretation that 

mercury CEMS can be applied to the cement industry based on 

successful use on utility boilers. The commenter evaluated the 

following issues:

Number of Installations in the Utility Industry – there are 35 –

40 continuous mercury monitors (CMMs) installed and certified 

to date (not yet with a National Institute of Standards and 

Technology (NIST) traceable calibration source).
Page 178 of 456

NIST Certification – In mercury CEMS certification requirements 

outlined in Performance Specification (PS)-12A, it states that 

all calibration and span gases must be NIST certified. The 

draft protocols were just released by NIST in July 2009. The 

major vendors of mercury CEMS are just now advertising NISTcertified calibration sources. Therefore, none of the mercury 

CEMS that have been previously installed are certified. NIST 

does not currently directly certify oxidized mercury 

calibrations. The Interim EPA Traceability Protocols now in 

place provide for certification of evaporative generators by 

certification of the individual components of the calibrator. 

Therefore, the language used in Section 7.0 that refers to a 

NIST trace oxidized mercury calibrator needs to be clarified 

or changed.

Difficulties Encountered in the Utility Industry – The industry 

commenter gave examples of power plants‘ difficulties with 

mercury CEMS.

Installation on Wet Stacks – Installing a mercury CEMS on a wet

stack can result in problems: plugging, corrosion, and buildup 

of solids. Although wet scrubbers are not currently common in 

the cement industry, under the proposed rule, they may be 

required to a greater extent, and many of these same problems 

with mercury CEMS potentially could occur for the cement 

industry as well.
Page 179 of 456

Data Output Requirements – There is no need for dry basis 

measurements under the proposed rule and the language in 

either Subpart LLL should be included to provide an exemption 

from this requirement for cement plants or PS-12A should be 

revised. This language needs to be clarified by EPA.

Cost – The industry commenter provided information about CEMS 

costs, estimating that if mercury CEMS were installed on all 

non-waste-burning U.S. cement facilities, the total capital 

costs would be approximately $45 million, with annual 

operating costs being about $25 million. 

Industry commenter 2901 stated that CEMS should not be used as a 

compliance method for cement plants for the following reasons:

EPA reported in 1997 on an experiment where CEMS were installed 

on a cement kiln burning hazardous waste. The Agency found 

substantial problems regarding mercury CEMS measurement 

accuracy and precision, deciding not to require Mercury CEMS 

at cement plants. The industry commenter stated that the 

primary issue is whether there is a NIST traceable standard 

that can be used to calibrate the unit. Because compliance is 

based on the production rate and on using a 30-day average, it 

is difficult to know what range to calibrate these units.

The reliability of CEMS on cement kiln stacks has not been 

demonstrated in the U.S., where standards and requirements are 
Page 180 of 456

different. Demonstrations in the U.S. at coal-fired power 

plants have different conditions than those at cement kilns. 

There is no legal imperative for EPA to require CEMS. Under the 

CAA, EPA‘s monitoring requirements must provide a reasonable 

assurance of compliance with emission standards Sierra Club v. 

EPA, 353 F.3d 976, 990-991 (DC Cir 2004) (Copper Smelters)

citing Natural Res. Def. Council, Inc. v. EPA, 194 F.3d 130, 

(D.C. Cir 1999). 

Response: Several commenters questioned the applicability of 

current continuous instrumental gaseous mercury CEMS 

technologies to cement kilns. Several commenters also raised 

technical issues about specific performance criteria in 

Performance Specification 12A (PS 12A) for gaseous Hg CEMS and 

expressed concern as to the availability of National institute 

of Standards and Technology (NIST) traceable Hg gas standards. 

NIST has recently completed certification of a  ̳NIST Prime‘ 

elemental mercury gas generator at concentrations of 41, 68, 85, 

105, 140, 185, 230, 287, and 353 μg/m3 and mercury gas generator 

vendors may now submit elemental mercury gas generators for 

certification to serve as  ̳Vendor Primes‘. Therefore NIST 

traceable mercury gas standards can now be made available in 

concentrations that exceed the equivalent mass standards for 

both existing and new kilns by between one and two orders of 

magnitude, thus providing the capability to accurately report 
Page 181 of 456

excursions well beyond either standard. We have provided 

responses to the comments on specific performance criteria 

regarding PS 12A in the response to comments document, and in 

several instances PS 12A has been revised in response to those 

comments. The Agency believes that the now revised PS 12A is 

fully capable of properly measuring the performance of gaseous 

Hg CEMS in many applications, including cement kilns. 

Regarding the applicability of the current commercially 

available gaseous Hg CEMS to cement kilns, and to wet or high 

moisture stacks in particular, we have considered the potential 

physical and chemical characteristics of such kiln stacks and 

does not consider them to be substantively different from those 

of other source categories, particularly utility boilers, where 

technical solutions have been deployed to enable the successful 

application, certification, and operation of gaseous Hg CEMS. 

One of several U.S. Hg CEMS manufacturers advises they have now 

installed approximately 400 Hg CEMS units on coal-fired power 

plants to meet regulatory requirements, including some with flue 

gas desulfurization systems with the higher stack gas moisture 

levels typical of these systems. These installations have 

included performance guarantees for system certification and the 

manufacturer also indicated a willingness to guarantee the 

performance of their units on cement kiln stacks.
Page 182 of 456

We recognize that each source will experience their own 

particular learning curve as with any new instrument, but if 

the source should experience an apparently insurmountable 

problem with a particular installation, they still have the 

option to either petition the Administrator for consideration 

of an alternative testing approach under §63.7(f) or to 

monitor Hg using a sorbent trap monitoring system by 

Performance Specification 12B (PS 12B). We disagree with the 

comment that PS 12 B requires further demonstration. The same 

technology (Method 30B, 40 CFR 60, Appendix A) was 

successfully used on several cement kilns in the process of 

collecting data to establish the emission limits in this rule 

with good precision and accuracy, and has also been widely 

deployed in the data collection program for the current MACT 

rule development program for utility boilers. EPA also 

believes that the growing body of evidence of the successful 

use of Hg CEMS in the utility industry in the US is further 

evidence that Hg CEMS can be used in the cement kiln industry. 

In addition to the knowledge regarding the use of Hg CEMS on 

cement kilns in Europe, EPA is aware of two instances where Hg 

CEMS have been installed on cement kilns in the U.S., with 

specific evidence of successful execution of seven day 

calibration drift checks, linearity (measurement error tests, 

as well as relative accuracy testing.
Page 183 of 456

Comment: Industry commenter 2845 stated that EPA should require 

that compliance with HCl limits should be measured by periodic 

stack tests. Because the HCl floors were developed from HCl 

stack test data, the standard for HCl should be based on 

periodic stack testing. EPA must evaluate valid data from Method 

321/ASTM D6348 stack tests instead of the data contained in 

Table 5 of the proposal. Using CEMS to measure compliance 

effectively makes the standard more stringent than what has been 

achieved by the best-performing sources. If CEMS compliance 

demonstration is retained, then the limit for CEMS compliance 

must be raised to reflect the added variability that will be 

measured by the CEMS. While continuous measurement will capture 

variability of emissions 24 hours per day, 7 days per week over 

the full range of process and control system operating 

conditions over the life of the plant and its associated quarry, 

the stack test is merely a snapshot in time. By definition, a 

stack test contains no parameter related to variability other 

than that obtained during the three hours of testing. In 

addition to the inherent variability of HCl emissions, a CEMS 

standard must also consider the inaccuracy of the CEMS as 

determined (and allowed) relative to the required stack test 

methods, the uncertainty of calibration standards/materials, and 

other factors affecting the sampling, transport, and analysis of 

HCl which is a highly reactive compound.
Page 184 of 456

Response: HCl CEMS will be measuring HCl with the same 

technology that was used in the period stack tests (M321) used 

to set the standard. An allowance for variability has been 

built in through the process of setting the standard, including 

setting the standard based on the 99th percentile UPL and 

increasing the standard to the practical quantitation limit of 

the analytic method.

Comment: Two industry commenters (2845 and 2859) said that EPA 

has not promulgated any regulations requiring PM CEMS at any 

source category due to its inability to address fundamental 

technical and policy issues and must resolve these issues 

through rulemaking before requiring PM CEMS at any cement 

plants. Furthermore EPA has not performed a legitimate 

technical analysis of emissions variability and compliance 

determination uncertainty to allow the use of PM CEMS for 

determining continuous compliance with a PM limit at cement 

plants.

The use of PM CEMS in Europe and other countries does not 

constitute a valid basis for application of PM CEMS at cement 

plants in the United States. Light scattering, light 

transmission, and extractive beta attenuation instruments are 

all inferential measurement devices and a correlation must be 

established to relate the device output to the actual PM 
Page 185 of 456

concentration, then the accuracy and bias of the reference test 

and the uncertainty of the statistical correlation, as well as 

the stability of the correlation must be considered. Under the 

German TUV and the European monitoring standard (EN 14181) these 

uncertainties are considered; emissions are not considered to 

exceed the allowable limit until the lower bound of the 

confidence interval and/or tolerance interval exceeds the 

emission limit; emission standards may contain different 

averaging periods requiring different levels of conformance; and

when a problem is encountered, the emphasis is on resolving the 

emission problem rather than direct enforcement and collection 

of financial penalties. All of these considerations place the 

European monitoring program in an entirely different regulatory 

context than the proposed PM monitoring requirements.

Response: We reject the industry commenters‘ assertions that PM 

CEMS have not been required via rulemaking because of unresolved 

fundamental technical or policy issues. Concerns about PM CEMS 

were identified and addressed prior to the January 2004 

publication of Performance Specification 11 and Quality 

Assurance Procedure 2 for PM CEMS (69 FR 1786, January 12, 

2004). As mentioned in that rule‘s preamble, ―...we believe that 

the PM CEMS field demonstrations completed to date encompass a 

range of operating conditions and emission characteristics...‖ 

including those exhibited by sources such as cement kilns. 
Page 186 of 456

Moreover, we disagree with the assertion that our analysis 

of PM emissions variability is not legitimate, yielding an 

overly-stringent PM emissions limit. The PM limit is based on 

our analysis of PM emissions from test data, adjusted from an 

hourly to a 30-day averaging period and further adjusted for 

variability. As mentioned in the preamble to the Credible 

Evidence Rule (62 FR 8314, February 24, 1997), we have addressed 

and continue to address concerns about perceived ―...limited 

number and distribution of test runs and the inherent 

variability in levels of emissions...‖ by a number of approaches, 

including changing emissions averaging periods.

Certainly, lengthening the averaging period beyond the 

duration associated with conducting a performance test 

(typically three hours) to 30 days without changing the value of 

the emissions limit does not increase stringency of an emissions 

limit. As mentioned in the description of the Salo and Pederson 

memoranda, ―...(t)he effect of the change from a 3-hour averaging 

time to a 30-day averaging time is to make the standard more 

lenient...‖41 Further, a statistically-based adjustment to 

account for emissions variability, and which, in this case, 

increases the numerical value of the standard (and its longer 

 

41 See Section 4.1.2.1 of the Credible Evidence Rule Response to 

Comment Document, available at 

<http://www.epa.gov/ttncaaa1/t1/fr_notices/certcfin.pdf>.
Page 187 of 456

averaging period) by fifty percent, does not make the standard 

more stringent.

Finally, the continuous collection of data used to assess 

compliance with this twice-adjusted standard does not create a 

limit more stringent that otherwise allowed, as discussed in the 

preamble to the Credible Evidence Rule, ―...continuous monitoring 

of the standards (has) no effect on the stringency of the 

standard...‖ (62 FR 8326, February 24, 1997).

Rather, consistent with the rulemaking description process 

given in Section 4.1.1 of the Credible Evidence Rule Response to 

Comment Document, we used our ―...judgment, based on available 

information, to establish emissions standards at (appropriate) 

levels where the standards can be met on a continuous basis by a 

well operated and maintained source that employs best 

demonstrated technology...‖42

Comment: Two industry commenters (2845 and 2859) had the 

following comments concerning technical issues associated with 

application of PM CEMS. EPA has not addressed nor resolved the 

primary technical issues limiting the effective application of 

PM CEMS at cement plants including:

 

42 See Section 4.1.2.1 of the Credible Evidence Rule Response to 

Comment Document, available at 

<http://www.epa.gov/ttncaaa1/t1/fr_notices/certcfin.pdf>.
Page 188 of 456

 inability to generate a sufficiently wide range of PM 

concentrations to establish an acceptable correlation 

(i.e., calibration),

 accuracy and precision limitations of reference method at 

PM levels necessary to generate valid correlation, and

 subsequent changes in effluent matrix and/or PM (i.e., 

particle size distribution, refractive index, particle 

density, etc.) that influence the stability of the 

correlation and hence, the relationship between the output 

of the inferential measurement device relative to actual PM 

concentration.

Valid PM CEMS correlations cannot be established for PM CEMS at 

cement plants due to limitations of process operation and 

control equipment in conjunction with the proposed emission 

limitation. The requirements in Appendix A, PS-11 for the PM 

CEMS correlation and in Appendix F, Procedure 2 do not provide a 

sufficiently reliable means to determine compliance with 

emission limitations.

Response: We have not identified problems cited by the 

commenters at existing installations. In fact, PS-11 and 

Procedure 2 are working well. We note that PS-11 has several 

features to address correlation issues. For example, PS-11 

provides for the addition of a zero point, which enhances the 
Page 189 of 456

ability to provide a calibration. We note that PS-11 has several 

features to address correlation issues due to any limitations of 

process operation and control equipment. PS-11 provides for the 

addition of a zero point. For example, if control equipment 

operations cannot be varied adequately to achieve higher PM 

concentrations, resulting in a cluster of data points at a very 

low level and making it difficult to achieve PS-11 criteria, 

then an artificial data point may be selected at zero that 

allows the correlation curve to be developed that meets the 

correlation criteria. It also strongly suggests the use of 

paired trains to insure that accuracy and precision is obtained. 

Changes in the effluent matrix could potentially be a problem 

with light scattering technologies but this has not been shown 

to be a problem with existing installations. This would not be 

a problem with beta attenuation monitors. Factors that influence 

the stability of the correlation are addressed in Procedure 2 

(40 CFR, Appendix F). Procedure 2 describes the required audits 

to insure that subsequent measurements are stable and within 

acceptable limits, thereby ensuring reliable and stable 

compliance measurement data.

Comment: Two industry commenters (2845 and 2859) had the 

following comments concerning PS-11 and Procedure 2. The 

requirements at §63.1349 for PM CEMS are incomplete and 

ambiguous and EPA has failed to specify important QA frequencies 
Page 190 of 456

and other information relevant to the implementation of PM CEMS 

in accordance with PS-11 and Procedure 2. The proposed Subpart 

LLL revisions fail to address critical elements including the 

following sections of PS-11 and Procedure 2:

 PS-11 3.20, species reference method as method defined in 

applicable regulations (Method 5 with 250oF filtration 

temperature) but this is inadequate for low concentrations 

where Method 5I should be used, and is inapplicable to 

sources with PM that condenses between the stack 

temperature (mill on and mill off, if applicable) and 250oF 

where Method 17 should be used or ASTM D 6831.

 PS-11, 6.2 You must ensure that the averaging time, the 

number of measurements in an average, the minimum data 

availability, and the averaging period for your CEMS 

conform to those specified in the applicable regulation -

but none are specified.

 When using PS-11, 6.5 Your CEMS must sample the stack 

effluent such that the averaging time, the number of 

measurements in an average, the minimum sampling time, and 

the averaging procedure for reporting and determining 

compliance conform to those specified in the applicable 

regulation - but none are specified.

 Procedure 2, 10.3 You must conduct a response correlation 

audit (RCA) and a relative response audit (RRA) at the 
Page 191 of 456

frequency specified in the applicable regulation... but none 

are specified.

 Procedure 2, 10.3, You must perform an RRA at the frequency 

specified in the applicable regulation... but none is 

specified.

 When using Procedure 2, 10.3(7) You must perform an RCA at 

the frequency specified in the applicable regulation... but 

none is specified.

 When using Procedure 2, 10.9 You must report the accuracy 

results for your PM CEMS at the frequency specified in the 

applicable regulation... but none is specified.

Response: We recognize that PS-11 does not specify a reference 

method; we have revised the final rule to specify Method 5 or 

Method 5I (40 CFR 60, appendix A) as the reference method. 

Facilities with issues in application of these reference 

methods, may petition the Administrator for alternatives or 

modifications under §60.8(b) or §63.7(f). The averaging times 

and data reduction specifications have been added to §§60.63(c) 

and 63.1350(b) of the rule. There is no specific data 

availability requirements, §§60.63(g) and 63.1348(b) require 

that monitoring be conducted at all times the affected source is 

operating except for periods of monitoring system malfunctions, 

repairs, or quality assurance/quality control activities. The 

language of the final rule has been revised to specify the 
Page 192 of 456

frequency of the Relative Response Audits (annually) and the 

Response Correlation Audits (every three years), for specifics, 

see §§60.63(c) (2) and 63.1350(b)(2). Absolute Correlation 

Audits are required by Procedure 2 on a quarterly basis. 

Comment: One environmental advocacy group commenter (2786) 

stated that EPA should not eliminate opacity standards in the 

proposed rule. The commenter stated that there are benefits to 

having an opacity standard in conjunction with a particulate 

matter standard. Opacity measurements can be made by anyone who 

is trained to measure opacity, which can include members of the 

public and not just inspectors, and opacity measurements are a 

cheaper method of getting more frequent measurements.

Response: We disagree. Given the sensitivity of the BLD and PM 

CEMs, we find the opacity requirements to be redundant.

Comment: One environmental advocacy group commenter (2898) 

stated that EPA should require PM CEMS and retain the opacity 

monitoring requirements. EPA is proposing installation and 

operation of a BLD system, along with stack testing using EPA 

Method 5 conducted at a frequency of five years for 

demonstrating compliance with the proposed PM emissions limit. 

As an alternative, a PM CEMS that meets the requirements of PS–

11 may be used, and EPA is proposing to eliminate the current 

requirement of using an opacity monitor. The proposed rule 

solicits comment on making the use of a PM CEMS a requirement. 
Page 193 of 456

The commenter stated that EPA should both require CEMS and 

retain the use of opacity monitors.

EPA should abandon the BLD system requirement outlined in the 

proposed rule and mandate the use of PM CEMS instead. The agency 

previously concluded that PM CEMS is a superior monitoring 

technology that can be implemented at a reasonable price. EPA 

has found that BLD systems, standing alone, are inadequate to 

verify compliance and has also found that continuous opacity 

monitors (COMS) operate as a useful check on PM emissions and 

proper operation of PM CEMS. 

Providing a superior level of compliance assurance is not 

the only benefit of PM CEMS. EPA has acknowledged that the 

assumptions to assure compliance are fewer and less conservative 

(direct measure of the standard is the top of the monitoring 

hierarchy), CEMS mean facilities need to monitor only one 

emissions parameter to assure compliance rather than multiple 

operating limits, often relevant to more than one standard, and 

that the cost of installing PM CEMS technology is reasonable. 

Response: We would support the use of multi-metal CEMS, should 

they become available. We have not yet seen evidence that COMS 

are well-suited for continuous compliance as are BLD or PM CEMS, 

so that requiring their use as a backup system would add 

monitoring costs to no special environmental benefit.
Page 194 of 456

Comment: Several industry commenters (2832 and 2859) opposed the 

proposed requirement to install CEMS in order to satisfy 

compliance assurance monitoring (CAM) for selected pollutants. 

Instead, the commenter proposed that CAM requirements be 

satisfied using periodic stack testing to the extent that stack 

testing is requested or require by state air permits. According 

to EPA‘s proposal, the MACT floor for new and existing sources 

in this industry will be determined by stack testing results of 

sources within the MACT pool. If EPA were to finalize a numeric 

emissions limitation based on this approach to setting the new 

and existing MACT floors, that limitation will be based on the 

same stack testing data. CEMs will have played no role in this 

process. It stands to reason that compliance assurance should be 

based on stack testing results, and not a CEMS data that has 

played no part in this process.

One industry trade association commenter (2916) stated that 

EPA can achieve a reasonable assurance of compliance without the 

use of CEMS. The requirement to use CEMS is unreasonably costly 

and unnecessary, given that other reliable means of showing 

compliance are available for all relevant pollutants. Raw 

material sampling and kiln parametric monitoring, in conjunction 

with periodic testing, would work well for THC and HCI. The 

sorbent trap method for mercury is a good alternative to mercury 

CEMS and should be retained in the final rule. EPA should 
Page 195 of 456

refrain from requiring PM CEMS in the final rule. Bag leak 

detection systems and parametric monitoring of ESPs are proven 

methods for assuring ongoing compliance with PM limits.

Response: We disagree. In the case of THC, emissions may 

change significantly due to a process change without any advance 

indication. In addition, the THC emission limits were 

established using data from CEMS, and the standard itself is a 

30-day average, requiring 30 monthly measurements (only 

practically obtainable with a CEM). Therefore, CEMS are the 

obvious compliance assurance choice. In the case of mercury 

emissions, short term test data do not necessarily reflect the 

long term emissions. In addition, the performance of the 

available mercury controls may be significantly affected by 

operational factors. To devise a test plan to clearly establish 

the performance of mercury control under all conditions would be 

difficult, and for that reason it would be difficult to 

establish the proper control device operating parameters and 

operating limits. Therefore, mercury CEMS are essential in 

demonstrating continuous compliance with the mercury emissions 

limits. If the facility does not have a wet scrubber, changes 

in raw materials, or fuels could significantly increase 

emissions without any indications unless a CEMS is used.

B. What are the significant comments and responses on 40 CFR 

part 60, subpart F?
Page 196 of 456

Comment: Several state and environment advocacy group commenters 

(62, 65, and 69) objected to EPA not proposing standards for 

greenhouse gas (GHG) emissions under the proposed NSPS. One 

state commenter (62) criticizes EPA‘s decision to not propose 

any NSPS for GHG emissions from Portland cement plants. The 

commenter states that even though the Courts have confirmed that 

GHGs are air pollutants subject to regulation under the CAA, EPA 

has not issued any such standards, instead issuing an Advance 

Notice of Proposed Rulemaking (ANPR) that seeks public comment 

on whether to regulate GHG emissions under the CAA at all. State 

commenter 62 protests this course of action, and requests that 

EPA revise the proposed rule to include NSPS for GHG emissions. 

According to state commenter 62, EPA‘s failure to propose 

NSPS for GHGs in the proposed rule violates §111 of the CAA (42 

U.S.C. §7411), which requires EPA to determine whether GHG 

emissions emitted by cement plants may endanger public health or 

welfare, and to promulgate NSPS for each air pollutant emitted 

by cement plants that contributes significantly to global 

warming pollution. The state commenter states that as the second 

largest industrial source of carbon dioxide emissions in the 

United States (emitting 45.7 million metric tons of carbon 

dioxide in 2006), the cement industry contributes significantly 

to GHG emissions and there can be no serious dispute that GHG 

emissions endanger public health and/or welfare. The ANPR that 
Page 197 of 456

EPA issued instead is no substitute for action and does not 

commit to regulating GHG emissions from any source.

State and environmental advocacy group commenters 65 and 69 

submitted several exhibits in support of their comments. A 

summary of the comments is presented here. To review the entire 

comment, please refer to the comment at www.regulations.gov. 

The state and environmental advocacy group commenters state 

that:

 EPA is required by §111 to promulgate NSPS for all 

pollutants emitted by a regulated source category including 

CO2 emission from cement plants and EPA‘s assertion that 

§111 does not compel the agency to regulate CO2 emissions 

is contrary to the Act‘s plain language. 

 Congress has expressly directed that NSPS address the 

emissions of ―any‖ air pollutant, a term that plainly 

encompasses CO2. 

 At a minimum, in directing that NSPS be established for 

sources that cause, or contribute significantly to air 

pollution which may reasonably be anticipated to endanger 

public health and welfare, Congress showed that it meant to 

require limits on emissions of any pollutants that cause or 

contribute to such endangerment. Because cement plants emit 

CO2 in such amounts that those emissions significantly 

contribute to ―air pollution which may reasonably be 
Page 198 of 456

anticipated to endanger public health or welfare,‖ EPA is 

legally required to issue standards of performance limiting 

those emissions. EPA cannot rationally assert that cement 

plant CO2 emissions do not meet these criteria, and the 

Agency‘s refusal to promulgate standards of performance is 

therefore unlawful. 

 EPA‘s contention that it can refuse to regulate CO2 

emissions on the basis of interactions with other CAA 

provisions is impossible to reconcile with §111, because 

that section clearly contemplates that EPA will adopt 

standards of performance covering pollutants that have not 

previously been subject to regulation under the Act. 

 Cement plants‘ emissions of CO2 cause, or contribute 

significantly to, air pollution which may reasonably be 

anticipated to endanger public health or welfare and 

significantly contribute to global climate change. 

 There are existing technologies that can reduce emissions 

of CO2 from cement plants. In addition to the suggested 

technologies, other measures that would also have CO2

reduction benefits include shifting from high carbon 

content fuels, such as coal, to lower carbon content fossil 

fuels, such as natural gas.

 Section 111(d) of the Act provides that EPA shall require 

states to implement and enforce standards of performance 
Page 199 of 456

for existing sources when the pollutant at issue is not 

regulated as a criteria pollutant or hazardous air 

pollutant. 

 EPA must also consult with the US Fish and Wildlife Service 

and National Marine Fisheries Service to insure that the 

final rule is not likely to jeopardize recently-listed 

endangered species.

Response: Due to issues related to the regulation of GHGs under 

the CAA, no standards of performance for GHGs were included in 

the proposal and none are being included in the final 

amendments. Promulgating a standard without first proposing it 

does not follow the accepted process of proposal and public 

comment that is required of EPA rulemakings. Also, we have not 

gathered the information we need on GHG emissions and control 

strategies for the Portland cement industry. EPA‘s decisions and 

plans for regulating GHG from this industry are discussed 

earlier in this document (see section IV.B.1.g).

Comment: Several private, state and environmental advocacy group 

commenters (59,60,63,68,70,71,72) approve of the proposed limits 

for NOx or believe more stringent limits are appropriate. One 

private commenter (59) states that the proposed standard is 

unjustifiably high, and will allow for greater NOx emissions 

than can be achieved with the installation of off-the-shelf 

pollution control technology. The commenter recommends a 
Page 200 of 456

standard of no greater than 0.5 lb NOx/ton clinker and states 

that SCR is an effective and proven technology to reduce NOx 

emissions from cement kilns and can reduce NOx emissions from 

cement kilns by greater than 90 percent, consistent with what 

has been observed with SCR in other industries. According to the 

private commenter, SCR can achieve this performance with costeffectiveness of approximately $1,500-$3,800/ton NOx, easily 

within regulatory cost thresholds for many NOx control programs. 

Regarding concerns over dust and plugging, the commenter cites 

three recent installations of SCR on cement kilns that show that 

SCR vendors can properly design and install units which manage 

the dust and successfully operate for many years. The commenter 

stated that numerous SCR companies believe that they can design 

and supply SCR systems for NOx control at cement plants where 

they will have to guarantee performance levels in legal 

contracts, and thus they would be at significant financial risk 

to advertise and sell an SCR system that was actually going to 

fail. The effectiveness of the technology to reduce NOx and 

other pollutant emissions from cement kilns, as demonstrated by 

the SCR installations on cement kilns in Europe and the numerous 

SCR installations on other heavy industries like coal-fired 

power plants and waste incinerators, is supported by the 

marketing, technical assessments, and reports prepared by 

numerous experts on this subject, including: three (3) cement 
Page 201 of 456

companies, five (5) SCR manufacturers, an independent blue 

ribbon panel, the U.S. EPA (twice), and the European IPPC. 

State commenter 68 believes that EPA‘s proposed NOx limit of 1.5 

lb/ton clinker underestimates the reductions that are achievable 

with SCR technology and recommends that SCR be identified as BDT 

for this sector and is ―the regulated future‖ for cement kilns. 

The commenter states that the agency has noted that hybrid 

combinations of SNCR and SCR could be used in new cement kilns 

to achieve greater reductions than would be possible with SNCR 

alone. SCR is also named by EPA as available technology for 

cement kilns in the Regulatory Impact Analysis for the Final 

Clean Air Visibility Rule or the Guidelines for Best Available 

Retrofit Technology (BART) Determinations Under the Regional 

Haze Regulations. As far back as 1999, EPA included SCR in a 

list of control technologies available for both dry and wet 

cement manufacturing processes, as did a Pechan & Associates 

Report prepared for EPA‘s Office of Air Quality Planning and 

Standards in September 2005. Therefore, SCR technology for the 

cement manufacturing sector has been considered feasible 

technology by EPA for some time. 

One state commenter (60) states that the NOx emission limit 

should be lowered to 1.0 lb/ton of clinker on a 24 hour rolling 

average for new PH/PC kilns and a limit added of 2.0 lb/ ton of 

clinker on a 24-hour rolling average if reconstruction or 
Page 202 of 456

modification of the kiln commences after June 16, 2008, and the 

final configuration is a long wet kiln or a long dry kiln. The 

state commenter states that the recommendations regarding PH and 

PH/C kilns should apply equally to projects at greenfield sites 

and brownfield sites stating that many of the advances in NOx 

control in the U.S. and Europe have been made at brownfield 

sites whether they have involved new kilns or reconstruction or 

modification of existing kilns. 

To support the state commenters recommended limits for NOx, the 

commenter provided the following information and included 

several supporting documents as attachments to the comments:

 A long-term value of 1.46 pounds per ton (lb/ton) of NOx 

clinker was achieved with no add-on control equipment when 

not accounting for slag use and 1.38 lb/ton when accounting 

for slag use at TXI Kiln 5 (a PH/C kiln) in Midlothian, 

Texas. 

 A long-term value of 1.98 lb/ton was achieved with no addon control equipment at Cemex Sta. Cruz (a PC/H kiln) in 

Davenport, California. The project involved an improvement 

to an existing calciner (commissioned in 1997) on an 

existing kiln to comply with an existing NOx limitation. 

 Titan America (a PH/C kiln) in Medley Florida and Giant 

Cement in South Carolina where average values of 1.62 and 
Page 203 of 456

1.88 lb NOx/ton were documented for new kilns with no addon control equipment at brownfield sites. 

 The results from the existing SCANCEM (an affiliate of 

Lehigh) Skövde PH kiln where emissions were reduced from 

4.4 lb NOx/ton (1995) by installation of a SNCR system and 

which achieved 0.72 lb/ton in 2005.

 The results from the existing SCANCEM Slite PH/C kilns 

where emissions were reduced from 4.0 lb NOx/ton (1995) by 

installation of an SNCR system and which achieved 1.01 

lb/ton in 2005. 

 The results from the existing Radici Cementeria di 

Monselice PH kiln where emission reductions to values as 

low as 0.20 lb NOx/ton were demonstrated by installation of 

a SCR system. The supplier guaranteed reduction of 90 

percent and realized reductions as high as 97 percent. 

State commenter 60 states that based on the foregoing, 

reductions on the order of 75 percent are achieved by welldesigned SNCR systems and 90 percent by SCR. Given that a new 

kiln can be designed such that emissions can be controlled to 

values between 1.5 and 2 lb/ton before add-on control, 1 lb/ton 

is achievable by SNCR. Given a kiln with less sophisticated 

design or particularly difficult raw materials achieving 3 to 5 

lb/ton, SNCR or SCR or a combination of the two can reduce 

emissions to values much less than 1 lb/ton. The commenter 
Page 204 of 456

states that the proposed averaging time of 30 days is a 

tremendous concession to the industry. The availability of 

reagent injection makes it easier to achieve the proposed 

standard on a 24-hour basis. The lowest permit limit for a 

project under construction in the United States applies to the 

Drake Cement in Arizona. The value is equivalent to 1.14 lb/ton 

on a 24-hour basis. A contract was awarded to F.L. Smidth who 

developed the calciner that achieves 2 lb/ton or less at TXI, 

Titan and Cemex as discussed above. The limit will be achievable 

using an SNCR system. 

State commenter (60) states that because long wet and long 

dry kilns use much more energy to make a ton of clinker, a 

higher NOx limit may be acceptable for these kilns. State 

commenter 60 agrees with EPA‘s assumption that new projects 

triggering the NSPS will actually result in a PH/C kiln. A 

project that might trigger a prevention of significant 

deterioration (PSD) review at a long kiln will probably 

incorporate emissions control measures to avoid PSD and a BACT 

determination for NOx and SO2. The measures to avoid PSD will 

also likely avoid the short-term emissions increases that would 

otherwise trigger the NSPS. 

Finally, with respect to the reconstruction provisions, it 

is not likely that a company will actually invest 50 percent of 

the value of an existing long kiln without taking the 
Page 205 of 456

opportunity to make it much more energy efficient through 

conversion to a PH/C kiln. The state commenter states that a 

separate standard for long kilns will avoid the unnecessary 

relaxation of the limits applicable to PH and PH/C kilns. The 

state commenter listed the following NOx reduction technologies 

that have been demonstrated for long kilns and submitted 

supporting documentation as attachments to the comment:

 Conversion from direct to indirect firing in conjunction 

with the installation of a multi-channel (Low NOx) burner;

 Mid kiln fuel injection (including tires);

 Near mid-kiln pressurized air injection;

 SNCR at long kilns; and

 Combination of SNCR with air injection.

One state commenter (63) described the advances in 

technology for controlling NOx emissions, especially SNCR and 

SCR, from Portland cement plants, and requests EPA consider the 

technological improvements and their applications when 

establishing NOx emission limits. The state commenter states 

that EPA continues to play a crucial role in encouraging 

innovation and in mobilizing supply chains to deliver 

technologies that improve our air quality and environment 

including the continued tightening of emission limits. This 
Page 206 of 456

encourages the industries such as the cement industry to work 

closely with equipment and component suppliers to ensure 

significant reductions in emissions in a timely and economical 

manner. The commenter states that with the improved processes 

that lower uncontrolled NOx emissions and with the addition of 

SCR, NOx limits of 0.25-0.5 lb NOx /ton clinker are achievable.

One state commenter (70) supports the proposed level for 

new, modified and reconstructed kilns of 1.50 lb/ton of clinker 

for NOx. Facilities can meet the 1.50 lb/ton of clinker for NOx, 

with SNCR alone or with SCR (either as a supplement or as an 

alternative to SNCR).

One state commenter (71) states that if new or modified 

systems would likely use the preheater/precalciner 

configuration, then what is achievable must be looked at and 

then apply the effect of the controls. If this approach is 

followed, the appropriate NOx emission limit should be in the 

range of 1.14 lb/ton of clinker. According to state commenter 

71, the traditional long dry cement kilns can attain a NOx 

emission level of 2.73 lb/ton of clinker without utilizing SNCR 

control technology. Based on a SNCR control efficiency of 50 

percent, a NOx emission level of 1.3 lb/ton of clinker is 

achievable. As a result, cement kilns with SNCR control 

technology can achieve a NOx emission level between 1.14 and 1.3 

lb/ton of clinker. However, this state commenter believes that 
Page 207 of 456

the NOx emission level from cement kilns can be further reduced 

by utilizing SCR control technology. State commenter 71 states 

that EPA dismisses the SCR technology used in Europe and

concedes that some mechanical problems were experienced in the 

early stages with plugging but these problems were resolved and 

the system remained in service for four years at the Solnhofen 

facility in Germany. According to the commenter, waste disposal 

should not be an issue because the spent catalyst could be added 

to the process as a source of alumina. State commenter 71 

previously conducted a Best Available Retrofit Control 

Technology (BARCT) assessment for a cement plant in our area and 

recommended SCR as the BARCT for this facility.

One environmental advocacy group commenter (72) states that 

the NSPS emission rate for NOx from cement plants should be 

lowered to 0.5 lb/ton of clinker on a 24 hour rolling average 

because of the ability of current plant designs to achieve very 

low rates of NOx emissions without the addition of add-on 

pollution controls. Currently available add-on controls can 

reduce NOx emission levels below the proposed 1.5 lbs of NOx per 

ton of clinker. There is a considerable operational experience 

with SNCR that shows it‘s capable of reducing NOx emissions to 1 

lb or less/ton of clinker when combined with a modern-designed 

kiln. SCR has been demonstrated in the utility industry and

Europe and can further reduce emissions.
Page 208 of 456

Response: The starting point for the NOx limit was the emission 

level that could be achieved with no add-on control device for 

NOx. To achieve the lowest NOx levels without add-on controls 

involves the use of state-of-the-art combustion technologies in 

conjunction with PH/PC kilns. In developing the proposed limits 

for NOx, we used emissions data showing that three recently 

permitted kilns had achieved average NOx levels of 1.62, 1.88, 

and 1.97 lb/ton of clinker through the use of combustion 

technologies such as low-NOx burners and staged combustion in 

the calciner (SCC). We assumed that through advanced combustion 

technology, an emission level of 2.5 lb/ton of clinker was 

generally achievable. Following proposal, commenters supporting 

the limit, commenters recommending lower limits, and commenters 

recommending higher limits submitted additional data on NOx 

emissions from US kilns as well as kilns operating in other 

countries. The data are summarized below.

Kiln Kiln type Process 

Controls

Add-on 

Controls

NOx 

Emissions 

Before Add-on 

Control (lb/ton 

clinker)

TXI, Midlothian, TX, Kiln 5 (2003) PH/PC LNB, slag None 1.38

LNB None 1.46

Cemex, Santa Cruz, CA (2006-2007) PH/PC SCC None 1.98

Titan America, Medley, FL (2007,2008) PH/PC SCC None 1.62

Giant Cement, Harleyville, SC

(2006,2007)

PH/PC SCC None 1.88

TXI Riverside, CA Long Dry Combustion, 

Process 

None 1.5

Long Dry Combustion, 

Process

None 1.5

Lafarge Sugar Creek MO (2004-2005) PH/PC LNB, SCC None 3.58
Page 209 of 456

Lafarge Calera, AL (2006-2007) PH/PC LNB, SCC None 2.06

Lafarge, Alexandria, Egypt (2007) PH/PC LNB, SCC None 2.03

Lafarge, Richmond, Canada (2007) PH/PC LNB, SCC None 2.64

Lafarge, Port La Nouvelle, France 

(2007)

PH/PC LNB, SCC None 2.65

Lafarge, Ewekoro, Nigeria (2007) PH/PC LNB, SCC None 3.38

Lafarge, Kujawy, Poland (2007) PH/PC LNB, SCC None 3.4

Lafarge, Harleyville, US (2007) PH/PC LNB, SCC None 3.48

Lafarge, Tetouan, Morocco (2007) PH/PC LNB, SCC None 4.07

AVG 2.41

The average uncontrolled NOx emissions for the listed kilns are 

2.4 lb/ton of clinker. If the result for the long dry kiln is 

removed, the average is 2.5 lb/ton. This result is consistent 

with the baseline NOx level used by EPA in the development of 

the proposed NOx limits. To allow for variations in process, 

fuel or feed, EPA selected a baseline level of 3.0 lb/ton of 

clinker.

To arrive at the emissions limit for NOx, we evaluated two 

add-on control technologies for BDT: SNCR and SCR. EPA agrees 

that SCR is a promising technology for the control of NOx 

emissions from Portland cement plants. The Agency also agrees 

that SCR is an attractive control alternative in that it has the 

advantage of reducing emissions of other pollutants in addition 

to reducing NOx by 80 to 90 percent. However, although SCR has 

been demonstrated at a few cement plants in Europe and has been 

demonstrated on coal-fired power plants in the US, the Agency is 

not satisfied that it has been sufficiently demonstrated as an 

off-the-shelf control technology that is readily applicable to 
Page 210 of 456

cement kilns. The experience with SCR use on coal-fired power 

plants in the US is not directly transferrable to Portland 

cement plants with the main difference being the lower dust 

loadings at power plants than would occur at cement plants. 

(Note this is not an issue for CEMS because they can be located 

downstream of the PM controls.) The experience at European 

kilns showed long periods of trial and error before the 

technology was operating properly. In particular, problems with 

the high-dust installations and the resulting fouling of the 

catalyst were problematic. This and other problems were 

eventually overcome, although at one of the early facilities to 

add SCR, the use of the SCR was discontinued in favor of a 

selective noncatalytic reduction (SNCR) system while the 

facility owners and operators gathered additional data to assess 

the advantages and disadvantages of the SCR system in comparison 

to the SNCR system. 

State commenters also noted that it would be possible to 

combine SNCR and SCR technology on the same kiln, thereby 

significantly reducing the amount of catalyst required. This 

could reduce the problem with catalyst fouling. We see no 

technical impediment to combining SNCR and SCR technology. But 

at the same time we have no data on this combined system to 

assess its effectiveness or potential for catalyst fouling. 
Page 211 of 456

At this time we therefore do not agree with the commenters 

that SCR can be considered best demonstrated technology and as a 

result have not established a NOx emission limit based on that 

technology. 

We determined SNCR to be BDT and applied a control 

efficiency for the SNCR to the baseline uncontrolled level to 

determine the appropriate NOx level consistent with application 

of BDT. As discussed in the preamble to the proposed rule, SNCR 

performance varies depending on various factors, but especially 

the normalized molar ratio (NMR), or the molar ratio of ammonia 

injected to NOx- higher removal efficiencies are associated with 

a higher NMR. SNCR performance has been shown to range from 20 

to 80 percent NOx removal. At proposal we used an efficiency of 

50 percent as representative of SNCR performance on average. 

Since then, additional information on SNCR performance has 

become available including data supplied by State commenters as 

well as a 2008 report by the Portland Cement Association. These 

data are summarized below. Reported removal efficiencies range 

from 25 to over 90 percent. According to a 2008 PCA report, 

ammonia slip occurs at molar ratios generally above 1.0. The 

graph below illustrates the relationship between the ammonia 

molar ratio, or NMR, and the performance of SNCR. EPA also 

examined the data to determine if uncontrolled NOx emissions 

affected SNCR performance since SNCR performance has been shown 
Page 212 of 456

to improve with higher uncontrolled NOx levels, but the data 

here did not show any effect between initial NOx concentration 

and SNCR performance. Using the data below, the average removal 

efficiency of SNCR is 60 percent. Thus, EPA believes the 50 

percent removal efficiency used to establish the NOx emission 

limit is a reasonable estimate of the SNCR performance that 

allows for an operating margin considering reasonable worst–case 

conditions that can be expected within the industry or source 

category as a whole. This operating margin should be sufficient 

to allow facilities where a greater than 50 percent reduction 

may be necessary to meet the 1.5 lb/ton clinker limit to 

increase ammonia injection to achieve greater than 50 percent 

reduction without causing ammonia slip. 

Kiln NOx 

Emissions 

Before SNCR

(lb/ton clinker)

NOx 

Emissions 

with SNCR

(lb/ton 

clinker)

Removal 

Efficiency (%)

Ammonia 

Molar 

Ratio

SCANCEM Skovde, Sweden (1995,2005) 4.4 0.7 84 1 - 1.2

SCANCEM Slite, Sweden(1995,2005) 4.0 1.0 75 1.2 - 1.4

Ash Grove, Durkee OR (1994 test) 4.75 1.0 >80 for most

Suwannee American (2008) Not reported 1.4

Florida Rock 3.1 1.7 47 0.1-0.65

3.8 2.2 42 0-1

1 7.0 3.2 55 0.7

2 4.3 3.0 30 0.7

3 4.6 2.3 50 0.7

4 4.0 2.0 50 0.6-0.7

5 3.8 2.9 25

6 4.0 2.4 40 0.25

6 4.0 2.0 50 0.5

7 3.4 1.7 50 0.5

7 3.6 0.9 75 0.8

7 3.2 0.6 81 1
Page 213 of 456

8 5.0 0.4 92 1.0-1.2

8 5.0 1.1 78 1.0-1.2

9 0.9 80-85 1.2-1.4

AVG. 4.2 1.7 60

Removal Efficiency vs NMR

R

2

 = 0.7067

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 10 20 30 40 50 60 70 80 90 100

RE% NMR

Figure 2, NOx Removal Efficiency vs. NMR

Comment: Several industry commenters (64, 73, 74, 75, 76, 77, 

78) commented on the difficulty of consistently achieving the 

NOx limit of 1.5 lb/ton clinker limit over time and at all new 

kiln locations and favored a higher limit or no limit. They 

state that it is important to note that consistent, long term 

compliance with this proposed limit may be difficult to achieve 

and there will be instances where compliance may not be possible 

at all. According to the industry commenters, different factors 

can influence NOx emissions such as:
Page 214 of 456

(1) Fuel type/quality - lower volatility solid fuels such as 

petcoke produce higher NOx emissions. Also, any problems with 

fuel quality as delivered to the plant can have a negative 

impact on NOx emissions;

(2) Raw mix burnability - harder burnability will give higher 

NOx emissions. Burnability is dependent on raw mix chemistry, 

fineness, and chemical deviation (impacted by homogeneity and 

operation of the quarry, which can vary over extended periods of 

time);

(3) Kiln bypass system - The size of the bypass for a given 

plant (if needed), and consequently the bypass emissions, 

depends on the chemistry of the raw mix and fuel(s) and the 

product standards that must be maintained to comply with 

regulations;

(4) Size/type of the preheater - new in-line calciners will 

normally give the lowest NOx emissions; however, in cases where 

the type of fuel(s) used dictates the need for a separate 

calciner (such as may be applied to utilize waste materials), 

NOx emissions will be higher. In addition, sometimes a new 

project will consist of upgrading an existing pyro system. In 

many of these cases the layout of the existing equipment is such 

that it cannot be modified to perform as well as a brand new 

calciner system, and will therefore have higher NOx emissions;
Page 215 of 456

(5) Sub-standard operation and maintenance of the kiln system -

this is the responsibility of the cement producer, but it is 

also expected that NOx emissions will increase slightly over a 

typical campaign between annual maintenance stoppages due to 

normal ―wear and tear‖ of the system; and

(6) SNCR efficiency and slippage - the ability of an SNCR 

system to reduce NOx emissions is not the same for all systems, 

especially for an existing pyro system that has been upgraded 

(due to potential lack of an optimum injection point) or a very 

large pyro system (due to lack of optimum mixing of ammonia and 

preheater gas). 

One industry commenter (75) states that although the 

removal efficiency of SNCR can theoretically be improved by 

increasing the quantity of ammonia injection, there is a 

practical limit to this approach. As ammonia injection rates 

increase, the potential formation of a secondary plume due to 

―ammonia slip‖ increases. In addition, sulfur in the raw 

materials results in SO2 and SO3 in the exhaust, which decreases 

the efficiency of ammonia injection and leads to operational 

issues such as solids accumulation and plugging downstream of 

the SNCR. As the industry commenter noted in the permit 

application for its proposed kiln, facilities with lower BACT 

emission limits are also those facilities with lower sulfur raw 

materials, notably plants located in Florida, thereby improving 
Page 216 of 456

the efficiency of SNCR. Given the baseline NOx emissions 

expected at a new plant, industry commenter 75 would need a 

control level of at least 70 percent to meet the proposed limit 

of 1.5 lb/ton. Industry commenter (75) is not confident that 

this can be done with SNCR. Therefore, the industry commenter 

recommends that the NOx standard be established at 1.95 lb/ton, 

which reflects a level of control achievable with the use of 

SNCR by all facilities without introducing the negative effects 

associated with pushing for high control levels.

One industry commenter (76) states that assuming a facility 

is already operating with best combustion practices (i.e., 

indirect fired fuel supply systems, low primary air burners, 

etc.) then the burnability of the raw mix has the greatest 

single impact on NOx emissions. Statistically speaking, most 

preheater precalciner cement kiln plants worldwide emit an 

uncontrolled NOx emission of 3.8 to 4.2 lb NOx/ton of clinker. 

With a 50 percent NOx reduction rate from the application of 

SNCR technology, a controlled emission rate of 1.9 to 2.1 lb 

NOx/ton of clinker could be expected for most kilns. As such, a 

1.95 lb NOx/t clinker limit for all new kiln applications seems 

achievable. The issues arise when people arbitrarily apply the 

50 percent reduction potential of SNCR to lower baseline 

emission numbers. (i.e., at a 3.2 lb NOx/ton of clinker 

uncontrolled emission, SNCR could reduce it to 1.6 lb NOx/ton of 
Page 217 of 456

clinker). While this might be true on an isolated case basis, it 

would be unwise to approach such a low level for a new NSPS 

limit for all new kilns because of the issue of burnability. In 

some cases it might be possible to reduce the baseline NOx 

levels with integrated control systems, such as Multi-Stage 

Combustion (MSC) installed on low NOx calciner system; but here 

again, the practicality of sustaining stable, continuous 

operation while simultaneously reducing the baseline NOx by 10 

to 30 percent is very site specific. Industry commenter 76 

believes that a controlled emission rate of 1.95 lb NOx/ton of 

clinker can be achieved by all new kiln applications providing 

SNCR is used as the principle measure to control NOx emissions, 

but excluding that portion of gases that may be extracted 

through a bypass system. 

One industry commenter (77) believes that under the worstcast combinations of raw materials, fuels and cement 

specifications and with the application of SNCR technology, a 

controlled emission rate of 2.0 lbs of NOx per ton of cement 

clinker can be achieved by all new kiln applications. However, 

if the kiln must incorporate a bypass for alkalis, chlorides or 

sulfur, the NSPS limits must allow for increased NOx emissions 

on a plant by plant basis due to the fact that bypass amounts 

can be anywhere from 5 percent to 100 percent in size.
Page 218 of 456

One industry commenter (78) states that very few kilns with 

alkali bypasses would have a chance of meeting the proposed 

limit long-term. One industry commenter (83) requested that EPA 

clarify whether the NOx limit applies only to a kiln‘s main 

stack or both the main and bypass stacks.

One industry commenter (73) believes that EPA failed to 

appropriately consider variables that affect uncontrolled NOx 

emissions from preheater/precalciner kilns employing SCC and LNB 

on an industry-wide basis. As a consequence, EPA relied upon a

limited database that did not reflect these variables and then 

made assumptions reflecting an incomplete understanding of 

variability in uncontrolled NOx that result from them. Industry 

commenter (73) recommends that EPA revise its proposed baseline

NOx emission standard from 1.5 to 2.0 lb/ton of clinker, and 

allow for adjustments of the standard upward from this value 

when bypasses are used, unusually hard burning raw mixes are 

used, or specific clinker types (such as oil well clinker) that 

require non-typical burning methods is being produced. When 

bypasses, hard burning mixes and/or clinker specifications 

require non-typical operational parameters, an adjustment factor 

should be allowed and evaluated on a case-by-case basis. The 

fact that individual kilns may be able to achieve a NOx emission 

rate as proposed (or even lower rates) is not determinative of 

what is an appropriate standard for the NSPS.
Page 219 of 456

Industry commenter (73) states that fuel volatility plays a 

major role in NOx emission control. The uncontrolled NOx 

generated in the precalciner alone can vary by as much as 1.4 

g/kg of clinker (2.8 lb/ton clinker) based on fuel volatility. 

Industry commenter (73) states that modern preheater/precalciner 

kilns fire approximately 55-65 percent of their fuel in the 

precalciner. The nitrogen content in the fuel is the main factor 

affecting fuel NOx formation. The fuel NOx produced in the 

precalciner is not directly proportional to the nitrogen content 

of the fuel. It also depends on the chemical form of the 

nitrogen in the fuel and the volatility of the fuel. Typically, 

fuel nitrogen in coals used by PH/PC kilns varies between 1.0 

and 2.0 percent. This difference can impact the uncontrolled NOx 

by as much as 1.5 lb/ton of clinker.

Industry commenter 73 states that a PH/PC kiln system uses 

hot gases from the kiln to both dry and heat the raw materials 

prior to calcination. The effectiveness of this system is 

related to the moisture content of the raw materials and their 

ability to absorb heat from the gases. If additional heat is 

required to dry or heat the raw materials, gases from a separate 

fuel-fired furnace or the clinker cooler are ducted to the raw 

mill. As a result, the moisture content of the raw materials 

directly influences the NOx emission rates. High moisture 

materials require additional energy to dry the materials in the 
Page 220 of 456

raw mill and/or preheater. This increased need for energy 

contributes to the amount of NOx emitted if the excess energy 

comes from burning additional fuel. Some plants may have up to 

20-25 percent moisture content in their raw mix – which results 

in a 15 to 20 percent increase in the kiln‘s specific heat 

consumption, as compared to a ―standard‖ raw mix that contains 

approximately 5 percent moisture. This additional energy need 

results in the combustion of more fuel which ultimately results 

in more uncontrolled NOx. 

On NOx emissions from alkali bypasses, commenter 73 states 

that because the gases within the bypass are not allowed to 

remain in the optimal SNCR temperature range, SNCR is not a 

feasible control option for these gases. The commenter shows 

(in graph form in their comments) that for a certain size kiln, 

bypassing 25 percent of its kiln gases will have an incremental 

increase of approximately 0.42 lb/ton of clinker in the 

controlled NOx emission rate.

Industry commenter 73 states that the three major kiln 

suppliers require a cement company to provide detailed 

information on raw materials (including moisture content), 

fuels, and clinker quality specifications prior to preparing a 

quotation and specifying emission guarantees. Uncontrolled 30-

day average NOx emissions can vary from less than 1.6 to greater 

than 4.6 lb/ton of clinker. SNCR has been demonstrated to reduce 
Page 221 of 456

NOx emissions from cement kilns; however, SNCR has not been used 

on cement kilns for an extended period of time. High removal 

efficiencies such as those stated in the preamble (i.e., 63 

percent at an ammonia-to-NOx ratio of 1.0) may result in adverse 

product quality or environmental impacts that are undesirable. 

In addition, the use of SNCR on larger kilns (>2,000,000 ton/yr 

capacity) may not be as effective due to the larger calciner 

duct diameter and the inability of the ammonia-reagent to mix 

thoroughly with the combustion gases. Based on limited data, 

removal efficiencies of 25-50 percent appear to be achievable 

without these adverse impacts. Therefore, industry Commenter 73 

believes that since NSPS is applicable to all new or 

reconstructed kilns, a reasonable baseline NSPS limit taking 

into account typical operating conditions and limitations stated 

above is 2.0 lb/ton of clinker. However, when non-typical 

conditions exist (bypass, hard burning mixes, and specific 

clinkers that require non-typical burning methods), an 

adjustment upward from the baseline value is appropriate and 

should be made on a case-by-case basis.

Industry Commenters (64, 73) stated that the proposed NOx 

limitations are substantially more stringent than the most 

stringent NOx limit that applies to cement plants in Europe, 

which converts to approximately 2.5 lb/ton of clinker produced 

although EPA asserts that this should be considered the 
Page 222 of 456

―baseline level of control that would occur with no additional 

regulatory action.‖ The industry commenter states that there 

are several problems with that analysis: 1) It does not appear 

that this conclusion is based on a ―statistically sound‖ 

analysis, as the statute requires; and 2) If the NSPS were set 

at 2.5 lbs of NOx per ton of clinker, then all affected 

facilities would have to meet the limitation continuously, 

rather than the ―average‖ performance of all affected facilities 

being at or below 2.5 lb/ton. Therefore, it would appear from 

EPA‘s rationale that setting an emission standard of 2.5 lb/ton 

would require some facilities, even if they have SCC and low-NOx 

burners, to implement additional NOx controls in order to comply 

continuously with that standard throughout the life of the 

facility.

The industry commenter states that there may be substantial 

differences between the NOx emissions that can be achieved by 

new, greenfield kilns and what can be achieved by 

―reconstructed,‖ brownfield kilns. NOx emissions are a function 

of fuel type and of raw material type, as described above. 

Reconstructed cement plants usually will have little or no 

control over their raw materials and may have limited control 

over the fuel they can use. 

The industry commenter states that EPA also needs to 

address the achievability of NOx limitations at cement plants 
Page 223 of 456

that have bypass stacks to control alkalinity because EPA has 

not presented any basis for concluding that SNCR is a 

demonstrated technology for meeting the proposed for facilities 

with bypass systems. 

Likewise, while EPA acknowledges that burnability may have 

a significant influence on NOx emissions, EPA has not explained 

how these differences are reflected in its analysis of the BDT 

and the proposed new NOx limits. Cement plants with hard-to-burn 

raw materials face much greater challenges in meeting a NOx 

limit and applying SNCR.

Industry commenter (64) agrees with EPA that SCR has not 

been demonstrated on preheater/precalciner kilns and that there 

are substantial unresolved issues about the potential for use of 

SCR at such cement plants. Industry commenter (64) also notes 

that, in addition to the cost which EPA identified as a 

disadvantage of a low dust SCR system, there would be 

substantial adverse energy usage and GHG consequences of reheating the flue gas for a low-dust SCR system.

Industry commenter (64) also believes that EPA has not 

given adequate consideration to ammonia slip from the use of 

SCNR. EPA seems to acknowledge that it does not have data on how 

ammonia slip will contribute to condensable PM emissions, and 

what if anything could be done to mitigate that contribution. 

EPA has not conducted a sufficient technical analysis to support 
Page 224 of 456

new NOx emission limits that would effectively require use of 

SNCR without addressing the ammonia slip issues. Ammonia slip 

may be a particular problem when SNCR is applied to particular 

designs, such as pyro systems that have been modified or that 

are particularly large. The inability of these systems to 

promote the reaction of ammonia with NOx also reduces potential 

control efficiency of SNCR on these systems.

Industry commenter (64) believes that the best approach is 

for EPA not to amend the NSPS to include NOx limits. If EPA 

nevertheless insists on including NOx in the revised subpart F 

NSPS, then industry commenter (64) recommends that for 

preheater/precalciner kilns (whether constructed at Greenfield

or brownfield sites), a NOx emission floor of 1.95 lb/ton of 

clinker be established as the NSPS limit. This limit would then 

be modified on a case-by-case basis to account for site-specific 

factors such as the presence of a bypass stack/duct or difficult 

to burn limestone or fuels, likely resulting in an emission 

limit in excess of the recommended floor. 

Response: The previous response addresses the industry 

commenters‘ concerns regarding the appropriateness of the NOx 

emissions limit. Based on the data received prior to proposal 

as well as data submitted after proposal, we feel confident that 

a well designed preheater/precalciner kiln using low NOx process 

technology such as LNB and SCC will be able to achieve a NOx
Page 225 of 456

emission level of 3 lb/ton of clinker or less and using a well 

designed and operated SNCR system will achieve NOx removal 

efficiencies of at least 50 percent without excess ammonia slip. 

But should a case occur where NOx emissions prior to application 

of SNCR are above 3.0 lb/ton clinker, we have set the limit 

sufficiently high that a facility could increase the NMR for 

SNCR to achieve removal efficiencies above 50 percent without 

causing excessive ammonia slip. Referring to Figure 2 above on 

NMR verses removal efficiency, we note that a NMR of 1 results 

in a removal efficiency above 75 percent, were a NRR of 1 

equates to a point where excessive ammonia slip can occur. 

The industry commenters point to numerous factors that can 

influence NOx emissions, fuel volatility and type of fuel 

nitrogen being two factors mentioned. However, we note that 

facilities have a choice of fuels. If their current fuel 

creates a high NOx situation, then they may need to modify their 

fuel choice. They again raise the issue of burnability but in 

the context of certain product types. Again we note that there 

are numerous facilities that achieve NOx levels well below 3.0 

lb/ton clinker located at various locations, some of which have 

―hard to burn‖ raw materials. The industry commenters provided 

no data to substantiate that the burnability issues associated 

with product types are any more severe that burnability issues 

associated with different raw materials. Given these different 
Page 226 of 456

locations, we would surmise that they also use different coals 

and possible other fuels. Given the breadth of the data, we 

find it unlikely that we have not sufficiently covered all the 

variables that affect NOx emissions. And also given the 

operating margin we have applied for SNCR (50 percent reduction 

on average versus a potential reduction of 75 percent), we 

continue to believe that the 1.5 lb/ton clinker emission limit 

is achievable under any reasonable foreseeable conditions 

without resulting in excessive ammonia slip (and the attendant 

potential to produce PM2.5). Industry commenters note that a 

larger kiln may have problems with ammonia distribution and an 

attendant reduction in SNCR efficiency. However, they provided 

no data to substantiate that claim, and we note that some of the 

kilns achieving levels well below 3.0 lb/ton clinker are above 1 

million tpy in size. For larger kilns, it should be possible to 

use a split exhaust dust if necessary to achieve the required 

ammonia distribution. 

Some industry comments expressed concern that sources will 

have to actually be able to reduce emissions to below the NOx 

limit in order to not exceed the limit. In proposing the NOx 

limits, EPA took this into consideration when it set the NOx 

limit as a 30- day average as opposed for example to a 24-hr 

limit. Doing so accommodates occasional daily excursions and 

accounts for operational variability.
Page 227 of 456

EPA agrees with the industry commenters that kilns equipped 

with alkali bypasses cannot be expected to meet the NOx limit

for the portion of the exhaust that goes to bypass. Bypass 

gases are quickly cooled and do not remain at a temperature long 

enough to be treated using an SNCR systems. EPA has revised the 

rule to clarify that for kilns with alkali bypasses, only the 

main kiln exhaust gases are subject to the NOx limit. Because 

all kilns do not require an alkali bypass and the bypass gas 

stream is a small fraction of the total kiln exhaust gas flow, 

the emission of NOx from the bypass will be minimal. 

Comment: Several state and environmental advocacy group 

commenters (60, 68, 70, 71, 72) stated that the proposed limits 

for SO2 were not sufficiently stringent. State commenter (60) 

recommends deleting the 90 percent reduction option, revising 

the limit for SO2 to 0.5 lb/ton clinker on a 24-hr rolling 

average if the kiln is a PH or PH/PC kiln and adding a limit of 

1.0 lb/ton clinker on a 24-hr rolling average if the kiln is a 

long wet or long dry kiln. State commenter (72) concurs on 

reducing the limit to 0.5 lb/ton for PH/PC kilns. State 

commenter (60) states that for PH and PH/C kilns the limit 

should apply equally to projects at greenfield sites and to 

projects at brownfield sites. Industry commenter (60) cites kiln 

performance at brownfield sites that have involved new kilns and

reconstructed or modified of existing kilns.
Page 228 of 456

Cement plants in Florida emit on the order of 0.10 lb SO2/ton 

clinker. Although these kilns use low-sulfur feed materials, all 

use coal and rely on the fuel SO2 control that is inherent in the 

PH and PH/C designs. The steps include reaction with alkali and 

incorporation into the clinker in the burning zone, dry 

scrubbing with finely divided lime in the calcination zone and 

moist limestone scrubbing in the raw mill. State commenters 

(60) and (72) cite the performance of the kilns used by EPA to 

establish the proposed limit. The key kiln (kiln 5 at TXI 

Midlothian, TX) upon which EPA based the proposed SO2 standard of 

1.33 lb/ton has actually operated at 0.37 to 0.57 lb/ton.

State commenters (60) and (72) state that raw materials in 

the Midlothian area are known to be high-sulfur and the TXI kiln 

has a wet scrubber to reduce (non-fuel) SO2 emissions. The limit 

for kiln 5 is now approximately 0.95 lb/ton following a 

production increase authorized by the Texas Commission on 

Environmental Quality (TCEQ). TXI Midlothian Kiln 5 and two 

other PH/C kilns (Kilns 1 and 2) operated by Holcim in the same 

city are controlled by wet scrubbers. All three have wet 

scrubbers yet there is a vast difference in performance between 

the TXI Kiln 5 and the Holcim Kilns 1 and 2. The commenter 

presented data on the SO2 performance of the 3 scrubber 

controlled kilns. According to the commenter, the TXI Kiln 5 can 

consistently achieve SO2 emissions less than 0.5 lb/ton if 
Page 229 of 456

required by a permit limit. The higher SO2 values for the Holcim 

kilns (> 4 lb/ton) represent the first year of joint operation. 

Thereafter, Holcim Kilns 1 and 2 were operated at levels between 

2 and 3 lb/ton. The commenter states that they can choose to run 

one to four pumps providing reductions in SO2 emissions ranging 

from 51 percent with a single pump in operation to 91 percent 

with four pumps in operation. 

State commenters (60) and (72) state that the Ash Grove 

Chanute PH/C kiln in Kansas achieves less than 0.30 lb SO2/ton 

despite high sulfur in the raw materials without even using a 

wet scrubber. State commenter (60) states that this performance 

is attained using important innovations (The F.L. Smidth DeSOx 

system and Environcare Micromist Lime system) not yet assessed 

by EPA. Attachments provided as part of the comment describe 

these technologies. State commenter (60) states that without 

controls, the proposed Chanute kiln would emit SO2 at the high 

rate of 12 lb/ton from raw material sources alone (i.e.,

exclusive of fuel SO2). According to state commenter (60), using 

the described technology, actual emissions from the Ash Grove 

Chanute kiln are less than 0.25 lb SO2/ton. 

According to state commenter (60), the Holcim Siggenthal PH 

kiln in Switzerland achieves approximately 0.05 lb SO2/ton using 

the POLVITEC coke filter installed in the 1990‘s. The POLVITEC 

system is used with various concurrent operational practices to 
Page 230 of 456

control NH3 (from an SNCR system), SO2, PM and metals. Among 

several functions, the coke filter captures the non-fuel SO2

generated in the PH. The coke is subsequently crushed and then 

burned with fuel in the main kiln burner. The SO2 from the PH 

then behaves like fuel SO2 and is incorporated into the clinker. 

Further details are available in an attachment submitted with 

the comment. The state commenter also states that SO2 emissions 

would be significantly less than 0.10 lb/ton of clinker. 

According to the state commenter, the Siggenthal plant emits 

much less SO2 than the average of Holcim cement plants in 

Switzerland and clearly less than 0.10 lb SO2/ton.

Sttae commenters (60) and (72) state that the Holcim 

Untervaz plant in Switzerland achieves between 0.04 and 0.21 lb 

SO2/ton using a wet scrubber despite, according to state 

commenter (72), the presence in the limestone of iron sulfide.

Holcim initially installed a dry scrubber at the Untervaz plant 

in the late 1980‘s. Recent data provided by the state commenter 

indicate significant reductions in SO2 emissions since 2002 

largely due to the replacement of the older dry scrubber with a 

more efficient and economic wet scrubber. 

According to state commenter (60), the areas where medium 

sulfur raw materials are present can implement programs similar 

to the Ash Grove installation without installing large wet 

scrubbers, dry scrubbers or coke filters. Finally selective 
Page 231 of 456

mining of the available raw materials with respect to sulfur 

content is an important SO2 control strategy for any new project. 

In summary, state commenter (60) recommends an NSPS SO2 limit of 

0.50 lb/ton of clinker on a 24-hour basis for PH and PH/C kilns.

State commenter (60) states that because long wet and long dry 

kilns use more energy to make a ton of clinker, a higher SO2

limit may be acceptable. State commenter (60) agrees with EPA‘s 

assumption that new projects triggering the NSPS will result in 

a PH/C kiln. According to the state commenter, projects that 

might trigger a PSD review at a long wet or long dry kiln will 

probably incorporate emissions control measures to avoid PSD and 

a BACT determination. The measures to avoid PSD will also likely 

avoid the short-term emissions increases that would otherwise 

trigger the NSPS. With respect to the reconstruction provisions, 

the commenter states that it is not likely that a company will 

actually invest 50 percent of the (undepreciated) value of an 

existing long kiln without taking the opportunity to make it 

much more energy efficient through conversion to a PH/C kiln. 

Nevertheless, the state commenter states that it is advisable to 

separate out the (unlikely) long kiln projects that trigger the 

NSPS without resulting in PH or PH/C kilns in order to avoid the 

unnecessary relaxation of the limits applicable to the much more 

likely PH and PH/C kilns. According to the state commenter, 

scrubbers are available for long kilns just as they are 
Page 232 of 456

available for PH and PH/C kilns. Other suggested strategies 

cited by the commenter include 1)Near mid-kiln pressurized air 

injection; and 2) Chains near the entrance of the kiln that can 

improve contact between the incoming wet limestone and the SO2-

laden exhaust gases containing both raw material and fuel 

sulfur.

State commenter (60) states that good SO2 control will make it 

possible to employ more aggressive NOx control and that the 

control of NOx and SO2 will also minimize the formation of ozone 

and fine PM in the environment.

State commenters (68, 70, 71) stated that State and local 

experts, who have had long experience with this industry, 

believe that the proposed NSPS limit for SO2 does not reflect 

what most plants are capable of achieving. Even taking into 

account regional variability in the pyritic sulfur content of 

the raw materials, these state commenters find that most cement 

kilns already achieve lower SO2 emissions than the 1.33 lb/ton of 

clinker proposed. 

State commenter (70) stated that after addressing raw 

materials in their most recent BACT review, SO2 limitations were 

0.9 lb/ton of clinker (30-day average) and 1.6 lb/ton of clinker 

(24-hr average); considerably lower than the 1.33 lb/ton of 

clinker (30 day average) proposed. 
Page 233 of 456

Response: Most kilns have low SO2 emissions because of the 

widespread availability of raw materials with low to moderate 

sulfur levels and the inherent scrubbing effects of modern PH/PC 

kilns with in-line raw mills. In fact, these two reasons have 

been cited as BACT in several NSR reviews. Sulfur in the fuel 

is typically not a problem because the sulfur content is 

relatively low and the sulfur has ample opportunity to react 

with clinker and dust both in the kiln and raw mill before the 

exhaust gases are discharged to the atmosphere. The sulfur that 

usually results in higher SO2 emissions is due to pyritic sulfur 

contained in the raw materials, especially the limestone. Where 

kilns have high levels of pyritic sulfur in their raw feed, wet 

scrubbers may be necessary to meet the limit for SO2. 

We note that in our analysis of the NESHAP, all new kilns 

will have to apply wet scrubbers to meet the HCl emissions 

limit. If this indeed occurs then costs of wet scrubbing to 

meet the SO2 will be negligible. Even in the absence of the 

NESHAP requirements, the application of a wet scrubber to a kiln 

that has high uncontrolled SO2 emissions is a cost effective 

approach to reducing SO2 emissions. At higher uncontrolled 

emission levels, wet scrubbers achieve emission reductions of 90 

to 95 percent. However, at lower uncontrolled SO2 levels, removal 

efficiency declines resulting in an increase in costeffectiveness. But at this point other cost-effective control 
Page 234 of 456

techniques, such as lime injection, are available. Based on 

these facts, we have lowered the SO2 emission limit in this final 

rule to 0.4 lb/ton clinker or a 90 percent reduction in SO2

emissions, which addresses the comments that the proposed SO2

limit was too high. 

Comment: Several industry commenters (64, 74, 75) expressed 

concerns that the proposed limits for SO2 are too stringent. One 

industry commenter (64) recommends that EPA not include SO2

limitations because EPA recognizes that there are only ―a few 

locations‖ where the raw materials contain high levels of 

sulfur, and in those few situations state regulations already 

impose SO2 emission limitations that require the type of 

technology EPA proposes as the basis for the proposed SO2

limitations. The industry commenter states that EPA assumes that 

one out of five new kilns will be sited where the raw materials 

are high in sulfur, requiring an SO2 scrubber or a lime injection 

system when in fact at existing plants there have only been a 

handful of situations where high-sulfur materials have been 

determined to justify wet scrubbers. According to the industry 

commenter, of 28 BACT determinations for SO2 for cement kilns 

since 1998 reported in the RACT/BACT/LAER Clearinghouse (RBLC), 

only 5 were based on wet scrubbers, and 1 specified a dry 

scrubber or hydrated lime injection while the majority required 

no add-on controls because of low-sulfur raw materials or 
Page 235 of 456

reliance on the inherent process absorption of SO2. The industry 

commenter states that the preamble information that the fact 

that only 5 kilns out of 178 kilns currently use a wet scrubber 

indicates that uncontrolled SO2 emissions are rarely high enough 

to justify add-on controls.

The industry commenter states that EPA acknowledges in the 

preamble that EPA is not obligated to promulgate NSPS for every 

pollutant emitted by sources in the source category. According 

to the industry commenter, the fact that very few cement kilns 

have been required to employ add-on controls for SO2 is evidence 

that there are few instances where cement kilns are contributing 

to SO2 NAAQS nonattainment, so there is no need for an SO2 NSPS 

to address ambient air quality problems. 

Industry commenter (64) states that allowing state and 

site-specific requirements to address SO2 at plants with highsulfur raw materials would address weaknesses in EPA‘s proposed 

SO2 standards. For example, although EPA assumes that the 

proposed SO2standards will require add-on controls only at 

facilities with high-sulfur raw materials, EPA has proposed a 

limit of 1.33 lb of SO2 per ton of clinker, whereas the average 

emission rate from just 18 data points from tests at facilities 

with moderate levels of sulfur in raw materials was 1.3 lb/ton. 

EPA‘s assumption that facilities with low and moderate levels of 

sulfur in raw materials would not have to install controls to 
Page 236 of 456

meet the proposed SO2 standards is not justified by those data. 

Requiring facilities with moderate uncontrolled SO2 emission 

levels to use add-on controls for SO2 would result in excessively 

high costs per ton of SO2 removed, as EPA has recognized. Also, 

the energy penalty associated with wet scrubbers could more 

appropriately be evaluated on a case-by-case basis, where it can 

be weighed against factors such as the level of uncontrolled SO2

emissions at the particular plant and the need for further SO2

reductions at that location for attainment and maintenance of SO2

ambient air quality standards. 

Industry commenter (64) states that because there is so 

little experience with add-on SO2 controls, EPA has relatively 

little data about the performance of those controls, and is 

proposing NSPS for SO2based solely on a recent BACT 

determination. The few kilns that will be subject to the 

proposed subpart F NSPS can be addressed through requirements 

for SO2 control derived through the RACT process or through NSR.

Industry commenter (64) states that if EPA persists in 

setting SO2 standards, there are a number of problems with the 

standards as proposed. For example, the percentage reduction 

alternative does not indicate that it is to be calculated on a 

30-day basis or how the percentage reduction is to be 

calculated. The industry commenter infers from the monitoring 

provisions that EPA intends for a source to compare the SO2
Page 237 of 456

concentration at the inlet to the scrubber to the SO2

concentration at the outlet from the scrubber, but this does not 

reflect the substantial reduction in SO2 emissions that occurs 

from contact with alkaline materials in the process. The 

industry commenter states that cement plants with moderate 

uncontrolled SO2 emissions may have to install controls and the 

90 percent reduction standard likely would be unachievable when 

applied to the relatively low inlet concentrations to the 

control device. The industry commenter states that it is even 

less clear how EPA would apply the percentage reduction standard 

to cement plants that choose to use lime injection

Industry commenter (64) states that the proposed 

regulations lack any discussion of whether the SO2 limitations 

apply during periods of startup, shutdown, and malfunction. 

Since substantial reduction of SO2 occurs naturally in the 

cement-making process because of the alkaline nature of the raw 

feed, industry commenter (64) states it would be reasonable to 

provide an exemption so that a wet scrubber or a lime injection 

system need not be operating, or operating at maximum 

efficiency, during periods of startup, shutdown, or malfunction. 

The industry commenter states that several recent BACT 

determinations involving scrubbers include special provisions 

for startup, shutdown, or malfunction.
Page 238 of 456

Industry commenter (64) states that the proposed limits for 

SO2 appear inconsistent with their stated technology basis, when 

compared to actual experience and to BACT determinations. 

According to the commenter, the majority of BACT determinations 

in the past 10 years that rely only on inherent SO2 reduction 

established limits higher than 1.33 lb/ton of clinker, except 

for plants in Florida, where the BACT determinations often 

recognized that raw materials are low in sulfur. According to 

the industry commenter, NSPS should be based on demonstrated 

technology that can be applied to the sector as a whole, rather 

than based on raw materials that are available only in a limited 

area of the country. These BACT determinations also undermine 

EPA‘s stated assumption that 1.3 lb/ton represents a ―moderate 

uncontrolled SO2 emission rate‖ and 13 lb/ton would be ―a high 

uncontrolled SO2 emission level,‖ since almost all BACT 

determinations for plants other than those in Florida imposed SO2

emission limits based on no add-on controls higher than 1.3 

lb/ton, and a number were higher than 13 lb/ton.

Industry commenter (64) states that if EPA insists on 

promulgating NSPS for SO2, it is essential that the standards 

retain the proposed option of meeting either a pounds per ton of 

clinker or a percentage reduction limit; but both limits should 

be higher than proposed. According to the commenter, the three 

wet scrubbers operated by Holcim were not designed to achieve 90 
Page 239 of 456

percent reduction, and the one BACT determination that contains 

an estimated percentage reduction in the RBLC uses 85 percent 

reduction. Importantly, cement plants in arid venues may not 

have the option to use a wet scrubber because of water 

restrictions. Especially if EPA persists in applying the revised 

NSPS to existing, modified or reconstructed facilities, wet 

scrubbers cannot be considered demonstrated available technology 

for all facilities in the source category. EPA does not, and 

industry commenter (64) believes EPA cannot, support a 90 

percent reduction requirement using dry scrubbers or lime 

injection. According to the industry commenter, to qualify as a 

limit based on demonstrated technology, the limit should be 

achievable at all types of plants, raw materials, and locations, 

and should be based on actual performance data rather than what 

is ―reportedly‖ achievable or anticipated.

Industry commenter (64) states that 1.33 lb/ton does not 

represent even the technology basis—alkaline wet scrubber on 

high-sulfur raw materials—that EPA has identified. The industry 

commenter states that EPA describes one kiln where uncontrolled 

SO2 emissions are ―about 13 lb/ton of clinker.‖ Achieving 90 

percent reduction of that uncontrolled emission rate would just 

meet the proposed mass limit, with no margin of compliance. And 

in any event, at least four of the BACT determinations for 

cement kilns in the past 10 years reported in the RBLC reflect 
Page 240 of 456

uncontrolled SO2 emission rates over 20.0 lb/ton. The proposed 

limit of 1.33 lb/ton thus does not reflect a limit that has been 

demonstrated as achievable applying wet scrubber technology to 

the range of sulfur contents present in cement plant raw 

materials.

One industry commenter (74) states that the proposed SO2

limit may be achievable in most cases but different plants will 

require different solutions to achieve that limit. Due to the 

large variations in the elemental and pyritic sulfur from plant 

to plant, industry commenter (74) does not believe that it is 

fair to have a set SO2 limit for all plants. Each plant's limit 

should be considered on a case-by-case basis considering the 

elemental or pyritic sulfur level in the raw materials and a 

reasonable target for the cost per short ton of removal to 

determine the controls that are used. In some cases this will 

give a limit lower than 1.33 lb/ton clinker and in other cases 

it will give a higher limit.

One industry commenter (75) states that: 1) Given the range 

of pyritic sulfur in our raw material, we would need to have a 

wet scrubber to meet this limit; 2) Lime injection is an 

effective control with less secondary impacts on water supply 

and energy use; and 3) A limit of 4 lb/ton of clinker should be 

adopted. This would allow greater use of lime injection, 

providing significant SO2 reductions while avoiding secondary 
Page 241 of 456

adverse environmental impacts and energy use of wet scrubbing. 

The industry commenter does not believe that the proposed limit 

adequately reflects the inherent variability of kiln emission 

rates, which are dictated by the characteristics of the raw feed 

to a kiln. Industry commenter (75)‘s kiln feed is locally mined 

raw materials used for over 100 years, with plans to continue 

the present mining operation for many years in the future. The 

standard, as proposed, would impose economic and environmental 

impacts beyond those considered by EPA.

Response: EPA disagrees with the industry commenter that the 

Agency is under no obligation to set standards for SO2 as 

evidenced by the lack of any SO2 limits previously or the 

infrequent need for scrubbers (5 out of 20 new kilns expected to 

need scrubbers). The absence of SO2 limits in the NSPS previously 

was due to the lack of a demonstrated add-on control technology 

applied to cement kilns during EPA‘s last review of the NSPS in 

1988. Since then, wet scrubbers have been installed on no less 

than five kilns and operate continuously. Other scrubbers, dry 

and wet, are installed on other kilns and operate as needed. In 

reference to the industry commenters‘ observations regarding 

permitted kilns in the RBLC database, EPA notes that three kilns 

for which scrubbers are reported as an add-on control device 

have permit limits far in excess of the NSPS SO2 limits 

indicating a clear need for national standards for SO2 emissions 
Page 242 of 456

from cement kilns. Furthermore, controlling SO2 emissions will 

control emissions of condensable fine particulate matter, 

leading to very significant environmental benefits. See Table 

13 in Section VI. Control is consequently in keeping with the 

ultimate goals of the Act in general and section 111 in 

particular: protecting and enhancing the Nation‘s air quality. 

See Asarco v. EPA, 578 F. 2d at 327. 

In response to the industry commenters‘ argument that kilns 

utilizing raw materials with moderate sulfur levels may have to 

install controls to comply with the SO2 limit, EPA agrees that in

a few instances those kilns may need to reduce their SO2

emissions. However, these kilns only need moderate reductions in 

SO2 and have options other than adding wet scrubbers (assuming no 

wet scrubbers are needed to meet the NESHAP HCl standard). In 

addition to the inherent scrubbing that occurs with the raw 

mill, cement plants can and do also practice careful selection 

of their raw materials to avoid high sulfur materials. There are 

cement plants that already limit the sulfur in their raw 

materials through their mining practices and through screening 

the raw materials they purchase. Owners and operators also 

reduce SO2 emissions by not burning sulfur-containing coal and by 

burning natural gas during kiln preheating, shutdown and during 

other maintenance periods when the kiln and/or raw mill are 

down. In those instances when some additional reduction is 
Page 243 of 456

necessary, a less expensive alternative to wet scrubbing is lime 

injection. Lime injection can achieve up to 70 percent reduction 

and may only be necessary during periods of higher SO2 emissions, 

for example when the raw mill is off.

In response to the industry commenter‘s questions of how 

the 90 percent reduction is to be determined, they are correct 

that the reduction is to be measured across the scrubber (in 

other words, measurements must be made to measure the SO2

entering the scrubber and the SO2 exiting the scrubber). Like 

the SO2 standard, the rule states explicitly that the 90 percent 

reduction is to be based on a 30-day average. In the case of 

lime injection, EPA believes this add-on control will only be 

used in situations requiring a modest reduction in SO2 emissions 

and these kilns will be able to meet the SO2 emissions limit. 

EPA disagrees with the industry commenter‘s suggestion that 

EPA provide some allowance for periods of startup, shutdown or 

malfunction as SO2 emissions are affected by whether the raw mill 

is operating or not. The industry commenter requested that EPA 

allow that during these periods, scrubbers or lime injection 

systems need not operate or at least need not operate at maximum 

efficiency. The industry commenter provided no data to indicate 

that, given the long averaging periods, a facility‘s raw mill up 

time versus down time is significantly affected by periods of 

startup and shutdown. In fact, the reason for the 30 day 
Page 244 of 456

averaging period was specifically to allow a lone enough 

averaging period that the higher emissions that occur for SO2

when the raw mill is down could be averages with long periods 

when the raw mill is operating. 

EPA disagrees with the industry commenter‘s statement that 

the proposed limits for SO2 appear inconsistent with their stated 

technology bases, when compared to actual experience and to BACT 

determinations. The standard was based on the performance of a 

scrubber-equipped kiln that processed high sulfur limestone. 

The alternative to the SO2 emission limit is to demonstrate a 90 

percent removal efficiency across the scrubber. EPA could not 

ignore the performance of this control technology, i.e., wet 

scrubbers, which are currently used full time at 5 cement 

plants. In reviewing the RBLC database, it is obvious that, in 

some cases, permit limits are not as stringent as they could be. 

One entry in the RBLC database even stated that the permit limit 

did not account for the reduction that would be achieved by the 

scrubber installed to control SO2. 

We note that industry commenters have stated that some new 

facilities may be located in areas where there is not sufficient 

water to operate a wet scrubber. However, we are not mandating 

the use of wet scrubber technology in these regulations, and we 

believe that sufficient alternative controls exist for SO2

controls that this issue would not preclude a facility from 
Page 245 of 456

meeting these emissions limits. As previously noted, these 

alternative technologies include dry lime injection, injection 

of sodium compounds, selective mining, injection of a finely 

divided lime slurry, use of lower sulfur fuels, and careful 

screening of purchased raw materials. Regarding the industry 

commenter‘s statements that the emission limit and alternative 

percent reduction should be less stringent, EPA notes that the 

kiln upon which the emission limit was based actually operates 

at levels under 0.6 lb/ton clinker based on information supplied 

by another commenter (60). The same industry commenter states 

that the limit for the kiln was reduced in 2007 from 1.33 to 

0.95 lb/ton following a production increase authorized by the 

Texas Commission on Environmental Quality. To support its

statement that a 90 percent removal efficiency is too high, the 

industry commenter noted that three Holnam (now Holcim) plants 

use scrubbers that are designed to operate at less than 90 

percent efficiency. Our data for the scrubbers at the Texas 

plant shows that the removal efficiency depends on the number of 

pumps in operation, with 91 percent efficiency when all four 

pumps are operating. The scrubbers at the Holnam facility in 

Michigan have not operated continuously due to various issues 

encountered. We also note that SO2 scrubbers in the utility 

industry have consistently achieved 90 percent SO2 since the 

1970s. We see no technical reason that the same removal levels 
Page 246 of 456

are not achievable in the cement industry. Therefore, where 

add-on controls are necessary to comply, scrubbers designed to 

achieve at least a 90 percent efficiency or greater are expected 

to be able to meet the 90 percent efficiency alternative; cement 

plants may be able to meet the emission limit by utilizing 

scrubbers with less than 90 percent efficiency or with lime 

injection if the uncontrolled SO2 levels are at moderate levels

(assuming that wet scrubbers are not needed to comply with other 

requirements, such as the HCl standard in the NESHAP).

EPA does not agree with the industry commenter that the 

limit of 1.33 lb/ton based on uncontrolled SO2 emissions of 13 

lb/ton of clinker and a 90 percent reduction leaves no margin 

for compliance. First, there are scrubbers with efficiencies 

higher than 90 percent removal efficiency, which, even if they 

can‘t meet the 1.33 (or the 0.4) lb/ton clinker emission limit, 

will be able to consistently meet 90 percent removal. Secondly, 

based on an industry commenter, the SO2 emissions from a PH/PC 

kiln are not likely to be as high as 13 lb/ton of clinker due to 

the scrubbing effects of the raw mill, but more in the range of 

4 – 5 lb/ton of clinker (75). This is supported by data from a 

2001 survey of cement plants showing that average SO2 emissions 

from PH kilns was 1.39 lb/ton of clinker (maximum of 6.54) and 

from PC kilns was 1.92 lb/ton of clinker (maximum of 8.83). 

Based on these data, use of a wet scrubber should be able to 
Page 247 of 456

meet the proposed SO2 limit of 1.33 and the final limit of 0.4 

lb/ton clinker. In some cases, a less expensive control such as 

lime injection may be adequate. Regarding the industry 

commenters reference to determinations reported in the RBLC that 

reflect uncontrolled SO2 emission rates over 20.0 lb/ton, these 

rates (if they are accurate) are associated with old wet kilns 

that do not have inline raw mills. In the case of one the two 

Michigan kilns, the quarries raw materials are known to have 

extremely high sulfur contents that are not seen at other 

locations. However, even if this location decided to build a 

new kiln, or to modify or reconstruct an existing kiln, they 

would still have the option to meet the 90 percent removal 

option.

In response to the industry commenter that states it is not 

fair to have a set SO2 limit for all plants and that each plant's 

limit should be considered on a case-by-case basis, EPA points 

out that the standards gives plants an alternative to the SO2

limit recognizing, just as the industry commenter states, that 

some plants may not be able to meet the SO2 limit due to the 

presence of pyritic sulfur in its limestone. Where plants cannot 

meet the SO2 limit, they have the option complying with the 

alternative limit of showing a 90 percent reduction in SO2

emissions.
Page 248 of 456

EPA disagrees with one industry commenter‘s suggestion of 

setting the SO2 limit at 4 lb/ton clinker in order to allow 

greater use of lime injection systems. Given that there are 

cost-effective controls to achieve much lower levels, a limit of 

4 lb/ton clinker simply cannot be considered BDT. We also note 

that EPA does not specify the type of control that must be 

used to meet the limit, or, for that matter, that any specific 

control has to be used. Plant owners may use any add-on 

control, such as lime injection if a control is necessary, or 

process control, such as selective mining, or a combination of 

add-on and process controls to meet the limit. The industry 

commenter states that it mined its materials locally for over 

100 years and plans to continue to do so. However, almost all 

cement plants in the country could make a similar statement, and 

it has no relevance and does not change the facts that costeffective SO2 controls are available to achieve SO2 emission 

levels of 0.4 lb/ton clinker. 

Comment: One industry commenter (64) supports EPA‘s decision not 

to set separate limits for condensable PM, PM2.5, or PM10 stating 

that these fractions of PM will be adequately controlled by 

facilities utilizing control equipment sufficient to meet the 

proposed limits for PM. The industry commenter also concurs that 

EPA does not have adequate data on the emissions or the 

demonstrated capability of various control technologies to meet 
Page 249 of 456

any specified level of these fractions of PM. The industry 

commenter states that they are not aware of any demonstrated or 

emerging technology that would provide better control of PM2.5, 

PM10, or condensable PM emissions specifically.

Response: The PM limits address filterable PM, including PM2.5

and PM10, but not condensable PM. EPA does not currently have 

sufficient information on emissions of condensable PM from 

cement kilns to set emission limits and the limited information 

we do have is highly uncertain. We also believe that these 

emissions will be controlled via controls on HCl in the NESHAP 

and SO2 in the NSPS. EPA has recently promulgated a new test

method for condensable PM (Method 202) which will allow for more 

reliable assessments of condensable PM. We anticipate that 

better data will be available at the time of the next review of 

the NSPS. 

Comment: Several industry commenters (64, 73, 74, 83) expressed 

concerns over the proposed NSPS for PM of 0.086 lb/ton of 

clinker. Industry commenter (64) states that the proposed limit 

of 0.086 lb/ton of clinker is not supported by the data 

available from new plants with the identified technology: it 

does not allow for deterioration of performance over time, and 

it does not allow for an adequate margin of compliance. 

Industry commenters believe that EPA used insufficient data to 

develop the standard and failed to consider situations where 
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gases from kilns, clinker coolers, and coal mills are combined 

for energy recovery purposes. Industry commenter (73) has spoken 

to major suppliers of cement kiln systems and believes that 

baghouse technology with membrane bags is capable of achieving a 

continuous outlet grain loading rate of 0.010 gr/dscf. Applying 

EPA‘s factors for standardized volumetric flow and feed-toclinker ratio (54,000 dscf/ton of feed and 1.65 tons feed/ton 

clinker), an appropriate NSPS PM standard would be 0.127 lb/ton 

of clinker for cement kilns and clinker coolers. Industry 

commenter (73) and (74) also believe that when clinker cooler 

and kiln gases are combined, the standard for these systems 

should be additive. 

The industry commenters stated that the standards must be 

set at a level that recognizes that there will be some 

deterioration in performance over time. According to the 

industry commenters, in most cases, emission rates achieved 

immediately after installation of pollution control equipment 

will not be representative of the performance over the life of 

the source, as the bags and the baghouse itself age and 

experience normal wear, even with proper operation and 

maintenance. Industry commenter (73) agrees with EPA that 

―fabric filters control generally to the same concentration 

irrespective of the PM loading to the filter inlet, though some 

variability in PM emissions from fabric filters does occur due 
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to seepage and leakage.‖ It is the seepage and leakage that 

becomes an issue as baghouses age. Industry commenter (64)

states that the PM stack testing data used by EPA in their 

analyses were obtained from kiln-baghouse systems that had 

operated for less than 5 years and, therefore, EPA has not 

demonstrated that they have proposed a limit that new sources 

can sustain long term. EPA has recognized this in numerous other 

rulemakings, including in setting emission standards for 

hazardous air pollutants at new cement kilns burning hazardous 

waste where they amended the PM limits for new sources in that 

NESHAP based on data demonstrating that the original PM standard 

was ―overly stringent in that it does not fully reflect the 

variability of the best performing source over time.‖

Response: As noted in the previous comments on the NESHAP PM 

limit, we have reevaluated the performance of PM controls for 

this source category and have determined that the appropriate 

NESHAP new source standard is 0.1 lb/ton clinker based on a 30 

day rolling average. Because all new sources will be required 

to meet this limit, we see no reason to set a different limit 

for the NSPS. We note the industry commenter‘s performance 

concerns. However, in setting the NESHAP limit we reviewed test 

data from a number of facilities. Some facilities had average 

emissions as low as 0.007 lb/ton clinker based on short term 

testing, and the average of the best performing five facilities 
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was 0.019 lb/ton(based on multiple short term testing). Based 

on this information, we believe that if the PM control is 

properly designed and maintained, PM levels well below the level 

we proposed, or the levels suggested by the commenter are 

possible. In addition, the data discussed were short term 

tests. Compliance will be based on a 30-day rolling average, 

which allows facilities to average out potential short term 

transients. 

VI. Summary of Cost, Environmental, Energy, and Economic 

Impacts 

A. What are the impacts of the final amendments to subpart LLL 

and subpart F?

We are presenting a combined discussion of the estimates of 

the impacts for these final amendments to 40 CFR part 60, 

subpart F and 40 CFR part 63, subpart F. The cost, 

environmental, and economic impacts presented in this section 

are expressed as incremental differences between the impacts of 

a Portland cement plant complying with the amendments to 40 CFR 

63 subpart LLL 40 CFR 60 subpart F and the baseline, i.e., the 

standards before these amendments. The impacts are presented 

for the year 2013, which will be the year that all existing 

kilns will have to be in compliance, and also the year that will 

represent approximately 5 years of new kiln construction subject 

to the amended NSPS emissions limits. The analyses and the 
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documents referenced below can be found in Docket ID Nos. EPAHQ-OAR-2007-0877 and EPA-HQ-OAR-2002-0051.

1. What are the affected sources?

We expect that by 2013, the year when all existing sources 

will be required to come into compliance, there will be 100 

Portland cement manufacturing facilities located in the U.S. and 

Puerto Rico that we expect to be affected by these final 

amendments. Of these facilities, approximately 5 are complete 

new greenfield facilities. These facilities will operate 158 

cement kilns and associated clinker coolers. We have no 

estimate of the number of raw material dryers that are separate 

from the kilns.

Based on capacity expansion data provided by the Portland 

Cement Association, we anticipate that by 2013 there will be 16

kilns and their associated clinker coolers subject to NESHAP new 

source emission limits for mercury, HCl, and THC, and seven 

kilns and clinker coolers subject to the amended NSPS for NOx 

and SO2. Some of these new kilns will be built at existing 

facilities and some at new greenfield facilities. The location 

of the kiln (greenfield or currently existing facility) has no 

bearing on our estimated cost and environmental impacts (since 

there are no longer separate standards for so-called greenfield 

new sources). 
Page 254 of 456

As previously noted there are two kilns with unusually high 

mercury emissions that we believe cannot meet the mercury

emissions limit without using more than one control technique. 

In developing the cost impacts, we assume that they would 

require multiple mercury controls. The only mercury controls

available for which we have detailed cost data are ACI and wet 

scrubbers, so we costed both controls to develop what we 

consider to be a reasonable cost estimate for these facilities. 

This does not imply that we believe these facilities will 

specifically use a combination of a wet scrubber and ACI to meet 

the mercury limit, but we do believe the combination of these 

control results in a reasonable estimate of cost. 

2. How are the impacts for this proposal evaluated?

For these final Portland Cement NESHAP amendments, EPA 

utilized three models to evaluate the impacts of the regulation 

on the industry and the economy. Typically in a regulatory 

analysis, EPA determines the regulatory options suitable to meet 

statutory obligations under the CAA. Based on the stringency of 

those options, EPA then determines the control technologies and 

monitoring requirements that sources might rationally select to 

comply with the regulation. This analysis is documented in an 

Engineering Analysis. The selected control technologies and 

monitoring requirements are then evaluated in a cost model to 

determine the total annualized control costs. The annualized 
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control costs serve as inputs to an Economic Impact Analysis 

model that evaluates the impacts of those costs on the industry 

and society as a whole. 

The Economic Impact Analysis model uses a single-period 

static partial-equilibrium model to compare a pre-policy cement 

market baseline with expected post-policy outcomes in cement 

markets. This model was used in previous EPA analyses of the 

Portland cement industry (EPA, 1998; EPA, 1999b). The benchmark 

time horizon for the analysis is assumed to be short and 

producers have some constraints on their flexibility to adjust 

factors of production. This time horizon allows us to capture 

important transitory impacts of the program on existing 

producers. The model uses traditional engineering costs analysis 

as ―exogenous‖ inputs (i.e., determined outside of the economic 

model) and computes the associated economic impacts of the final

regulation.

For the Portland Cement NESHAP, EPA also utilized the 

Industrial Sector Integrated Solutions (ISIS) model which 

conducts both the engineering cost analysis and the economic 

analysis in a single modeling system. The ISIS model is a 

dynamic and integrated model that simulates potential decisions 

made in the cement industry to meet an environmental policy 

under a regulatory scenario. ISIS simultaneously estimates 1) 

optimal industry operation to meet the demand and emission 
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reduction requirements, 2) the suite of control technologies 

needed to meet the emission limit, 3) the engineering cost of 

controls, and 4) economic impacts of demand response of the 

policy, in an iterative loop until the system achieves the 

optimal solution. The peer review of the ISIS model can be 

found in the docket.

43 This model was revised based on peer 

review comments and comments on the proposed rule and was used 

to develop cost and economic impacts of the final rule. 

In a Technical Memo to the docket, we provide a comparison 

of these models to provide an evaluation of how the differences 

between the models may impact the resulting estimates of the 

impacts of the regulation. For example, the Engineering 

Analysis and Economic Impact Analysis evaluate a snapshot of 

implementation of the final rule in a given year (i.e., 2013, 

based on 2005 dollars) while ISIS evaluates impacts of 

compliance dynamically over time (i.e., 2005-2013). In general, 

given the optimization nature of ISIS, ISIS accounts for more 

flexibility when estimating the impacts of the regulation. For 

example, when optimizing to meet an emission limit, ISIS allows 

for the addition of new kilns, as well as kiln retirements, 

replacements, expansions and the installation of controls. In 

the Engineering Analysis the existing kiln population is assumed 

 

43 See Industrial Sector Integrated Solutions Model and Review of 

ISIS Documentation Packages dated August, 2010.
Page 257 of 456

to be constant even though normal kiln retirements occur. Based 

on these differences, the total control costs from the 

Engineering Analysis are higher than the total control cost 

estimated in ISIS. 

We have not yet developed ISIS modules to calculate non-air 

environmental impacts and energy impacts. Therefore, these 

sections only contain impacts calculated by the traditional 

engineering methods. 

In addition, we have not yet developed ISIS modules to

calculate non-air environmental impacts and energy impacts. 

Therefore, these sections only contain impacts calculated by the 

traditional engineering methods. 

3. What are the air quality impacts?

For the Portland Cement NESHAP and NSPS, we estimated the 

emission reductions that will occur due to the implementation of 

the final emission limits. EPA estimated emission reductions 

based on both the control technologies selected by the 

engineering analysis and the ISIS model. These emission 

reductions are based on the estimated kiln population in 2013. 

Under the final limit for mercury, we have estimated that 

the emissions reductions will be 14,700 lb/yr for kilns subject 

to the exiting source emissions limits. For kilns subject to 

new source emissions limits, the emissions reductions will be 

1,900 lb/year in 2013.
Page 258 of 456

Under the final limits for THC, we have estimated that the 

emissions reductions will be 9,800 tpy for kilns subject to 

existing source limits, which represents an organic HAP 

reduction of 3,400 tpy. For kilns subject to new source limits, 

THC emissions will be reduced by 720 tpy. This represents an 

organic HAP reduction of 250 tpy.

Under the final limit for HCl, we have estimated that 

emissions will be reduced by 4,700 tpy for kilns subject to

exiting source limits and 1,100 tpy for kiln subject to new 

source limits. 

The final emission limits for PM represent a lowering of 

the PM limit from 0.5 lb/ton of clinker to.04 lb/ton of clinker 

for existing kilns and for new kilns, a lowering to 0.01 lb/ton 

of clinker. These new limits are based on 30-day rolling 

averages measured with a CEM. We have estimated that PM 

emissions will be reduced by 9,500 tpy for kilns subject to the 

existing source limits and 2,000 tpy for kilns subject to the 

new source limit. These estimates include only direct PM 

reductions, and do not include secondary PM reductions that 

occur as a result of concurrent control of SO2 discussed below. 

The PM emission reductions that occur as a result of the final 

NSPS limits are included in the totals shown above since the 

final NSPS PM limit is equal to the new source NESHAP limit.
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The control strategies likely adopted to meet the final 

standards for mercury, THC and HCl will also result in 

concurrent control of SO2 emissions. For kilns that use an RTO 

to comply with the THC emissions limit, it is necessary to 

install an alkaline scrubber upstream of the RTO to control acid 

gas and to provide additional control of PM and to avoid 

plugging and fouling of the RTO. Scrubbers will also be used to 

control HCl and mercury emissions. Reductions in SO2 emissions 

associated with controls for mercury, THC and HCl are estimated 

at 230 tpy, 11,200 tpy, and 98,400 tpy, respectively, so that 

total reduction in SO2 emissions from existing kilns will be an 

estimated 95,500 tpy. The SO2 emission reduction totals also 

include the reduction that will result from the final NSPS limit 

for SO2. If we were to break out the NSPS SO2 reduction 

separately, a new 1.2 million tpy kiln equipped with a scrubber 

will reduce SO2 emissions by 190 tpy on average or about 14,300

tpy in 2013. 

These controls will also reduce ambient concentrations of 

secondary PM2.5 as well. This is PM that results from atmospheric 

transformation processes of precursor gases, including SO2. Note 

that the PM emission reductions above do not reflect reductions 

in secondary PM formation. For these rules, the reduction in 

secondary PM formation represents a large fraction of the total 

reduction in ambient levels of PM, which is discussed in the 
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benefits section of the preamble below. However, with the data 

available, we are unable to estimate the fraction of ambient PM 

reduction resulting specifically from the reduction in SO2

emissions. 

Under the final limit for NOx, we estimated that the 

emission reduction for a 1.2 million tpy model kiln will be 600 

tpy. The nationwide emissions reduction 5 years after 

promulgation of the final standards was estimated at 6,600 tpy.

In addition to this traditional estimation of emission 

reductions, EPA employed the ISIS model to estimate emission 

reductions from the NESHAP and NSPS. The estimation of emission 

reductions in the ISIS model accounts for the optimization of 

the industry and includes the addition of new kilns, kiln 

retirements, replacements, and expansions as well as 

installation of controls. Using the ISIS model, in 2013 we 

estimate reductions of 12,627 lbs of mercury, 10,809 tons of 

THC, 4,307 tons of HCl, 5,729 tons of PM (does not include 

reductions in secondary PM), and 80,245 tons of SO2, and 14,159 

tons of NOx compared to emissions that would occur in 2013 in 

the absence of the NESHAP and NSPS. AS noted, the ISIS model 

estimates lower SO2 reductions because the model optimizes kiln 

retirements, replacements, and expansions as well as 

installation of controls. We did not determine ambient PM 

benefits based on the ISIS model‘s predicted emission 
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reductions. However, even with this lower SO2 reduction 

estimate, the secondary PM impacts would likely constitute a 

majority of the total ambient PM impacts. More information on 

the ISIS Model and results can be found in the ISIS TSD and in a 

Technical Memo to the docket.

Under the final standards, new monitoring requirements are 

being added. Particulate matter CEMS are being required on 

kilns and clinker coolers. For cement kilns, CEMS are required 

for measurement of THC, NOx and SO2. For kilns that do not have 

wet scrubbers, CEMS are required to monitor HCl emissions. 

Continuous emission measurement (CEMS or sorbent traps) are 

required for measurement of mercury emissions. There is 

insufficient data to quantify the emissions reduction that will 

result from these requirements. However, emissions reductions 

will occur as a result of the availability of continuous 

information on kiln and control device performance and a 

reduction in the length of time that operations are outside of 

acceptable conditions. Also, periods of excursions from 

acceptable conditions will be identified more quickly with 

continuous monitoring than with less frequent approaches, thus 

reducing the duration of such excursions. 

4. What are the water quality impacts?

We estimated no water quality impacts for the proposed 

amendments. The requirements that might result in the use of 
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alkaline scrubbers will produce a scrubber slurry liquid waste 

stream. However, we assume the scrubber slurry produced will be 

dewatered and added back into the cement-making process as 

gypsum. Water from the dewatering process will be recycled back 

to the scrubber. The four facilities (five kilns) that 

currently use wet scrubbers in this industry report no water 

releases at any time.44 We requested comment in the Portland 

Cement NEHSAP proposal on the potential for water releases due 

to wet scrubber system purges and any regulations that might 

apply. Though commenters raised concerns of the possibility of 

water impacts, they did not provide a rationale of why it would 

be expected when it is not occurring at the four facilities that 

currently use wet scrubbers, due to their on-site reuse of 

water. If discharges did occur, there would be a potential for 

water quality issues. But given these facts, we believe our 

estimate of no water quality impacts resulting from production 

of waste water by wet scrubbers is reasonable. 

The addition of scrubbers will increase water usage by 

about 4,200 million gallons per year. For a new 1.2 million tpy 

kiln, water usage will be 72 million gallons per year or 630

million gallons by 2013 for all kilns subject to new source 

limits for HCl and NSPS limits. 

 

44 Summary of Responses to Requests for Water Impacts 

Information. August 5, 2010.
Page 263 of 456

We did receive comments that in some areas there is not 

sufficient water available to support this increase in water 

use. We do not have sufficient data to perform an analysis of 

this situation, but we note that other less water intensive 

controls (dry injection of various sorbents, spray dryers) are 

available for control of HCl. This is further discussed in the 

cost impacts section.

5. What are the solid waste impacts?

The potential for solid waste impacts are associated with

greater PM control for kilns, waste generated by ACI systems and 

solids resulting from solids in scrubber slurry water. As 

explained above, we have assumed little or no solid waste is 

expected from the generation of scrubber slurry because the 

solids from the slurry are used in the finish mill as a raw 

material. All of the facilities currently using wet scrubber 

use mix the gypsum created in the scrubber with clinker in the 

finish mill. A commenter noted that the synthetic gypsum can be 

difficult to dewater, but currently operating facilities seem to 

have solved this issue. Another commenter notes that facilities 

with low SO2 levels may produce such small amounts of gypsum. 

Theoretically, this could result in a situation where it is 

impractical to dewater the gypsum, and it must be land filled. 

However, we anticipate that the total amounts of waste will not 
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be significant and the cost impact (compared to the total 

scrubber costs) will be minimal. 

The PM captured in the kiln fabric filter (cement kiln 

dust) is essentially recaptured raw material, intermediate 

materials, or product. Based on the available information, it 

appears that most captured PM is typically recycled back to the 

kilns to the maximum extent possible. Therefore we estimate 

that any additional PM captured will also be recycled to the 

kiln to the extent possible. 

Where equipped with an alkali bypass, the bypass will have 

a separate PM control device and that PM is typically disposed 

of as solid waste. An alkali bypass is not utilized on all 

kilns. Where one is present, the amount of solid waste 

generated from the alkali bypass is minimal, usually about 1 

percent of total CKD in control devices, because the bypass gas 

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

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

raw mill. 

Waste collected in the polishing baghouse associated with 

ACI that might be added for mercury or THC control cannot be 

recycled to the kiln and will be disposed of as solid waste. An 

estimated 122,000 tpy of solid waste will be generated from the 

use of ACI systems on existing kilns. A typical new kiln 

subject to new source mercury standards equipped with an ACI 
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system will be expected to generate 1,800 tons of solid waste 

per kiln or, assuming all 16 of the kilns subject to new source 

standards will add ACI systems, about 35,000 tpy in the year 

2013.

In addition to the solid waste impacts described above, 

there is a potential for an increase in solid waste generation 

if a facility elects to control its mercury emissions by 

increasing the amount of CKD wasted rather than returned to 

process. This will be a site-specific decision, and we have no 

data to estimate the potential solid waste that may be generated 

by this practice. However, we expect the total amount to be 

small for two reasons. First, wasting cement kiln dust for 

mercury control represents a significant expense to a facility 

because it will be essentially wasting either raw materials or 

product. We anticipate this option will not be used if the 

amount of CKD wasted will be large. Second, we believe that 

cement manufacturers will add the additional CKD to the finish 

mill to the maximum extent possible rather than waste the 

material. 

6. What are the secondary impacts?

Indirect or secondary air quality impacts include impacts 

that will result from the increased electricity usage associated 

with the operation of control devices as well as water quality 

and solid waste impacts (which were just discussed) that will 
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occur as a result of these final revisions. We estimate these 

final revisions will increase emissions of criteria pollutants 

from utility boilers that supply electricity to the Portland 

cement facilities. We estimate increased energy demand 

associated with the installation of scrubbers, ACI systems, and 

RTO. The increases for kilns subject to existing source 

standards are estimated to be 1,700 tpy of NOx, 900 tpy of CO, 

3,000 tpy of SO2 and about 90 tpy of PM. For kilns subject to new 

source standards, increases in secondary air pollutants are 

estimated to be 440 tpy of NOx, 230 tpy of CO, 760 tpy of SO2 and 

20 tpy of PM. We also estimated increases of CO2 to be 0.9

million tpy for kilns subject to existing source standards and 

209,000 tpy for kilns subject to new source standards.

The increase in electricity usage for the pumps used in the 

SNCR system to deliver reagent to the kiln are negligible.

7. What are the energy impacts?

The addition of alkaline scrubbers, ACI systems, and RTO 

added to comply with the final amendments will result in 

increased energy use due to the electrical requirements for the 

scrubber and ACI systems and increased fan pressure drops, and 

natural gas to fuel the RTO. We estimate the additional national 

electrical demand to be 800 million kWhr per year and the 

natural gas use to be 1.2 million MMBtu per year for kilns 

subject to existing source standards. For kilns subject to new 
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source standards, the electrical demand is estimated to be 199

million kWhr per year. 

8. What are the cost impacts?

Under the final amendments, existing kilns are expected to 

add one or more control devices to comply with the final 

emission limits. In addition, kiln and clinker coolers will be 

required to install varying numbers of CEMS or continuous 

emissions monitors. We performed two separate cost analyses for 

this final rule. In the engineering cost analysis, we estimated 

the cost of the final amendments based on the type of control 

device that was assumed to be necessary to comply with the final

emission standards. Based on baseline emissions of mercury, THC, 

HCl and PM for each kiln and the removal efficiency necessary to 

comply with the final emission limit for each HAP, an 

appropriate control device was identified. In assigning control 

devices to each kiln where more than one control device will be 

capable of reducing emissions of a particular HAP below the 

limit, we assumed that the least costly control will be 

installed. For example, if a kiln could use either a scrubber 

or ACI to comply with the final limit for mercury, it was 

assumed that ACI will be selected over a scrubber because an ACI 

system will be less costly. ACI also is expected to achieve a 

higher removal efficiency than a scrubber for mercury (90 

percent versus 80 percent). In some instances, a more expensive 
Page 268 of 456

technology was considered appropriate because the selected 

control reduced emissions of multiple pollutants. For example, 

even though ACI will be less costly than a scrubber for 

controlling mercury, if the kiln also had to reduce HCl (and, 

for new kilns subject to the NSPS amendments SO2) emissions, we 

assumed that a scrubber will be applied to control HCl as well 

as mercury because ACI will not control HCl. However, for many 

kilns, our analysis assumes that multiple controls will have to

be added because more than one control will be needed to control 

all HAP. For example, ACI may be considered necessary to meet 

the limits for THC/organic HAP and/or mercury. For the same 

kiln, a scrubber will also be required to reduce HCl emissions. 

In this case we allocate the cost of the control to controlling 

mercury emissions, not to the cost of controlling HCl emissions. 

In addition, once we assigned a particular control device, in 

most cases we assumed mercury, HCl and THC/organic HAP emissions 

reductions will equal the control device efficiency, and not the 

minimum reduction necessary to meet the emissions limit. We 

believe this assumption is warranted because it matches costs 

with actual emissions reductions. In the case of PM, we assumed 

the controlled facility will emit at the average level necessary 

to meet the standard (i.e., we assumed for PM that the 

controlled facility will emit at 0.01 lb/ton clinker, the 

average emission level, not 0.04 lb/ton clinker, the actual 
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emissions limit), because the final emissions levels are 

extremely low. 

As previously discussed, in the case of the two facilities 

that require mercury emission reduction of 98 percent or more, 

we estimated the cost impacts by costing the two mercury control 

for which we have cost data, ACI and wet scrubbers. We believe 

this estimate is a conservative estimate of the costs these 

facilities will ultimately incur to meet the mercury emissions 

limit, based on the fact that they may be able to meet the limit 

using dust shuttling and/or treatment of cement kiln dust, 

which, based on the limited amount and size of equipment 

required, is expected to have lower costs than wet scrubbing. 

In a separate analysis performed using the ISIS model, we 

input into ISIS the baseline and controlled emissions rates for 

each pollutant, along with the maximum percent reduction 

achievable for a particular control technology, and allowed ISIS 

to base the control required on optimizing total production 

costs. In addition, the ISIS model accounts for normal kiln 

retirements that will occur even in the absence of any 

regulatory action (i.e., as new kilns come on-line, older, less 

efficient and more costly to operate kilns are retired). In the 

first cost analysis, total national annual costs assume that all 

kilns currently operating continue to operate while 20 new kilns 

come on-line. In the ISIS model, the two highest mercury 
Page 270 of 456

emitting kilns requiring a 98+ percent mercury control are 

assumed to shut down in 2013 because no single mercury control 

applied to these kilns can meet a 98+ percent mercury reduction. 

Table 11 presents the resulting add-on controls each 

approach estimated was necessary to meet the final emissions 

limits.

Table 11. Control Installation Comparison

LWS ACI LWS+ACI MB FF WS+RTO RTO SNCR

Engineering 

Analysis 115 151 2 28 0 10 0 7

ISIS Model 30 42 29 6 2 6 15 7

In the engineering analysis, we estimated the total capital 

cost of installing alkaline scrubbers and ACI systems for 

mercury control, including monitoring systems, will be $339

million with an annualized cost of $113 million. Most of the ACI 

systems installed for mercury control will also control organic 

HAP and THC. Where ACI does not provide sufficient control of 

organic HAP and THC, RTO/wet scrubbers are used. The estimated 

capital cost of installing RTO/wet scrubbers to reduce THC 

emissions will be $253 million with annualized cost of $49

million. The capital cost of adding scrubbers for the control of 

HCl is estimated to be $1,882 million with an annualized cost of 

$261 million. The capital cost of adding membrane bags to 

existing fabric will be $57 million with annualized cost of $16 

million. The total capital cost for the final amendments for 
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kilns subject to existing source emissions limits will be an 

estimated $2.2 billion with an annualized cost of $377 million.

The estimated emission control capital cost per new 1.2 

million tpy kiln is $3.2 million and the annualized costs are 

estimated at $1.2 million for mercury and THC/organic HAP 

control, and $3.6 million for HCl control. Because the new kiln 

will be equipped with a baghouse even in the absence of the rule 

and because the ACI system, which includes a polishing baghouse, 

will be installed for mercury and organic HAP control, there 

will be no additional cost for PM control. Under the NSPS, 7 new 

kilns will install SNCR to control NOx and add NOx CEMS at a 

capital cost of $19.6 million and an annualized cost of $10.9 

million. The control of SO2 under the NSPS will be accomplished 

by wet scrubbers installed for HCl control under the NESHAP so 

that no control costs are attributable to the NSPS. There will 

be SO2 monitoring cost estimated at $1.1 million capital cost and 

$0.3 million annualized cost for the 7 new kilns subject to the 

NSPS. Flow monitoring devices are needed in conjunction with 

CEMS for NOx and SO2. Capital costs for flow monitoring devices 

will be $0.25 million capital and $0.1 million annualized costs. 

National annualized cost by the end of the fifth year for all 

new kilns will be an estimated $80.6 million.

In the ISIS results, we are not able to separate costs by 

pollutant because the model provides an overall optimization of 
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the production and air pollution control costs. The total annual 

costs of the ISIS model for the NESHAP and NSPS are $350 million 

in 2013. This estimate is significantly lower than the total 

costs estimated by traditional methods. 

It should be noted that for cases where more than a 50 

percent reduction in HCl was required, we costed a wet scrubber. 

We note that some commenters have stated that some new and 

existing facilities may be located in areas where there is not 

sufficient water to operate a wet scrubber. However, in this 

rule we are not mandating wet scrubber control technology. 

Other control techniques are available (hydrated finely ground 

lime, spray dryers, fuel and additive switching) that we believe 

would allow a cement kiln to meet the HCl emission limits in 

areas where sufficient water for a wet scrubber is not 

available. However, we do not have data available on costs for 

these alternatives controls or techniques, some of which would 

be site specific. We would anticipate that costs of these 

techniques would be no more expensive that a wet scrubber. 

Therefore we believe that by costing wet scrubber technology in 

these situations we have not underestimated costs.

9. What are the economic impacts?

EPA employed both a partial-equilibrium economic model and 

the ISIS model to analyze the impact on the industry and the 

economy. 
Page 273 of 456

The Economic Impact Analysis model estimates the average 

national price for Portland cement could be 5.4 percent higher 

with the NESHAP and NSPS, or $4.50 per metric ton, while annual 

domestic production may fall by 11 percent, or 10 million tons 

per year. Because of higher domestic prices, imports are 

expected to rise by 3 million metric tons per year. Operating 

profits fall by $241 million. 

Precise job effect estimates cannot be estimated with 

certainty. Ideally, whenever a regulatory change results in a 

reallocation of labor or other factors of production in an 

economy, a general equilibrium approach should be applied to 

estimate the attendant economic impacts. Unfortunately, time and 

resource constraints prevented the creation of a model with the 

spatial and sectoral resolution necessary to analyze the final 

rule. However, Morgenstern et al (2002) provides a theoretical 

framework which allows us to approximate some of the relevant 

general equilibrium effects by identifying three economic 

mechanisms by which pollution abatement activities can 

indirectly influence: higher production costs raise market 

prices, higher prices reduce consumption, and employment within 

an industry falls (―demand effect‖); pollution abatement 

activities require additional labor services to produce the same 

level of output (―cost effect‖); and post-regulation production 

technologies may be more or less labor intensive (i.e., 
Page 274 of 456

more/less labor is required per dollar of output) (―factor-shift 

effect‖).

Several empirical studies, including Morgenstern et al. 

(2002), suggest the net employment decline is zero or 

economically small (e.g., Cole and Elliot, 2007; Berman and Bui, 

2001). However, others show the question has not been resolved 

in the literature (Henderson, 1996; Greenstone, 2002). 

Morgenstern et al. use a 6-year panel (U.S. Census data for 

plant-level prices, inputs [(including labor], outputs, and 

environmental expenditures) to econometrically estimate the 

production technologies and industry-level demand elasticities. 

Their identification strategy leverages repeat plant-level 

observations over time and uses plant-level and year fixed 

effects (e.g., dummy variables for plant and years). After 

estimating their model, Morgenstern show and compute the change 

in employment associated with an additional $1 million ($1987) 

in environmental spending. Their estimates cover four 

manufacturing industries (pulp and paper, plastics, petroleum, 

and steel) and Morgenstern et al. present results separately for 

the cost, factor shift, and demand effects, as well as the net 

effect. They also estimate and report an industry-wide average 

parameter that combines the four industry-wide estimates and 

weight them by each industry‘s share of environmental 

expenditures.
Page 275 of 456

Historically, EPA has most often estimated employment 

changes associated with plant closures due to environmental 

regulation or changes in output for the regulated industry (EPA, 

1999a; EPA, 2000). This partial equilibrium approach focuses 

only on the ―demand‖ portion of the projected change in 

employment and neglects other employment changes. EPA provides 

this estimate because it employs the most detailed modeling for 

the industry being regulated even if it does not capture all 

types of employment impacts. In addition to the employment 

effects identified by Morgenstern et al., we also expect that 

the substitutes for cement (e.g., asphalt) would expand 

production as consumers shift away from cement to other 

products. This would also lead to increased employment in those 

industries. Focusing only on the ―demand effect‖, it can be seen 

that the estimate from the historical approach is within the 

range presented by the Morgenstern ―demand effect‖ portion. This 

strengthens our comfort in the reasonableness of both estimates. 

In April of this year, EPA started including an estimate based 

on the Morgenstern approach because it is thought to be a 

broader measure of the employment impacts of this type of 

environmental regulation. Thus, this analysis goes beyond what 

EPA has typically done because the parameters estimated in the 

Morgenstern paper were used to estimate all three effects 

(―demand,‖ ―cost,‖ and ―factor shift‖). This transfer of results 
Page 276 of 456

from the Morgenstern study is uncertain but avoids ignoring the 

―cost effect‖ and the ―factor-shift effect.‖

Using the historical approach, we calculated ―demand 

effect‖ employment changes by assuming that the number of jobs 

declines proportionally with the economic model‘s simulated 

output changes. As shown in Table 3-10, using this limited 

approach, the employment falls by an 1,500 jobs, or 

approximately −10%.45 By comparison, using the Morgenstern 

approach, we estimate that the net employment effects could 

range between 600 job losses to 1,300 job gains. 

EPA has solely used this historical estimate in the past as 

a measure of the projected employment change associated with a 

regulation. However there are a number of serious shortcomings 

with this approach. First, and foremost, the historical 

approach only looks at the employment effects on the regulated 

industry from reduced output. Second, to arrive at that 

estimate, EPA needed to string together a number of strong 

assumptions. The employment impacts are independent of the 

performance of the overall economy. This rule takes effect in 

three years. If the economy is strong, the demand for cement 

strong, it is unlikely that any contraction in the industry will 

take place, even with the regulation. Second, we assume that 

 

45 To place this reduction in context, it is a similar to the 

decline experienced during the latest economic downturn; 

approximately 2,000 jobs (see Appendix A, Table A-3). 
Page 277 of 456

all plants have the same limited ability to pass on the higher 

costs. In reality, plants should be modeled as oligopolists for 

each of their regional markets. Finally, EPA assumed that 

employment is directly proportional to output. This is 

unlikely, and biases the results towards higher employment 

losses. The Morgenstern methodology is a more complete 

consideration of probable impacts of a regulation on the 

economy. 

Table 12: Job Losses/Gains Associated with the Final Rule 

Method 1,000 Jobs

Partial equilibrium model −1.5

(demand effect only)

Literature-based estimate (net effect [A + B + 

C below])

0.3

(−0.6 to +1.3)

A. Literature-based estimate: Demand effect −0.8

(−1.7 to +0.1)

B. Literature-based estimate: Cost effect 0.5

(+0.2 to +0.9)

C. Literature-based estimate: Factor shift 

effect

0.6

(+0 to +1.2)

We calculated a similar ―demand effect‖ estimate that used 

the Morgenstern paper. EPA selected this paper because the 

parameter estimates (expressed in jobs per million [$1987] of

environmental compliance expenditures) provide a transparent and 

tractable way to transfer estimates for an employment effects 

analysis. Similar estimates were not available from other 

studies. To do this, we multiplied the point estimate for the 

total demand effect (−3.56 jobs per million [$1987] of 
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environmental compliance expenditure) by the total environmental 

compliance expenditures used in the partial equilibrium model. 

For example, the jobs effect estimate for is estimated to be 807 

jobs (−3.56 × $378 million × 0.6).46 Demand effect results are 

provided in Table 12. It is not appropriate to substitute the 

data from that approach in to the Morgenstern due to the 

incompatibilities of the underlying data. Since the result from 

the historical approach is within the confidence bounds for the 

Morgenstern results for the ―demand effect‖, we are comfortable 

that the more general Morgenstern result is a good 

representation of the change in employment.

We also present the results of using the Morgenstern paper 

to estimate employment ―cost‖ and ―factor-shift‖ effects. 

Although using the Morgenstern parameters to estimate these 

―cost‖ and ―factor-shift‖ employment changes is uncertain, it is 

helpful to compare the potential job gains from these effects to 

the job losses associated with the ―demand‖ effect. Table 12 

shows that using the ―cost‖ and ―factor shift‖ employment 

effects may offset employment loss estimates using either 

―demand‖ effect employment losses. The 95% confidence intervals 

are shown for all of the estimates based on the Morgenstern 

 

46 Since Morgenstern‘s analysis reports environmental 

expenditures in 1987 dollars, we make an inflation adjustment to 

the engineering cost analysis using the consumer price index 

(195.3/113.6) = 0.6) 
Page 279 of 456

parameters. As shown, at the 95% confidence level, we cannot be 

certain if net employment changes are positive or negative.

Although the Morgenstern paper provides additional information 

about the potential job effects of environmental protection 

programs, there are several qualifications EPA considered as 

part of the analysis. First, EPA has used the weighted average 

parameter estimates for a narrow set of manufacturing industries 

(pulp and paper, plastics, petroleum, and steel). Absent other 

data and estimates, this approach seems reasonable and the 

estimates come from a respected peer-reviewed source. However, 

EPA acknowledges the final rule covers an industry not 

considered in the original empirical study. By transferring the 

estimates to the cement sector, we make the assumption that 

estimates are similar in size. In addition, EPA assumes also 

that Morgenstern et al.‘s estimates derived from the 1979–1991 

are still applicable for policy taking place in 2013, almost 20 

years later. Second, the economic impact model only considers 

near-term employment effects in the cement industry where 

production technologies are fixed. As a result, the economic 

impact model places more emphasis on the short-term ―demand 

effect,‖ whereas the Morgenstern paper emphasizes other 

important long-term responses. For example, positive job gains 

associated with ―factor shift effects‖ are more plausible when 

production choices become more flexible over time and industries 
Page 280 of 456

can substitute labor for other production inputs. Third, the 

Morgenstern paper estimates rely on sector demand elasticities 

that are different (typically bigger) from the demand elasticity 

parameter used in the cement model. As a result, the demand 

effects are not directly comparable with the demand effects 

estimated by the cement model. Fourth, Morgenstern identifies 

the industry average as economically and statistically 

insignificant effect (i.e., the point estimates are small, 

measured imprecisely, and not distinguishable from zero). EPA 

acknowledges this fact and has reported the 95% confidence 

intervals in Table 12. Fifth, Morgenstern‘s methodology assumes 

large plants bear most of the regulatory costs. By transferring 

the estimates, EPA assumes a similar distribution of regulatory 

costs by plant size and that the regulatory burden does not 

disproportionately fall on smaller plants.

EPA identified ten domestic plants with significant 

utilization changes that could temporarily idle until market 

demand conditions improve. It should be noted that some of 

these plant may be idled even in the absence of this action 

based on a review of recent history of this industry. The 

plants are small capacity plants with unit compliance costs 

close to $8 per ton and $241 million total change in operating 

profits. Since these plants account for approximately 10

percent of domestic capacity, a decision to permanently shut 
Page 281 of 456

down these plants will reduce domestic supply and lead to 

additional projected market price increases.47

The estimated domestic social cost of the final amendments 

is $880 million. There is an estimated $121 million surplus 

gain for other countries producing cement. The social cost 

estimates are significantly higher than the engineering analysis 

estimates, which estimated annualized costs of $466 million. 

This is a direct consequence of EPA‘s assumptions about existing 

domestic plants‘ pricing behavior. Under baseline conditions 

without regulation, the existing domestic cement plants are 

assumed to choose a production level that is less than the level 

produced under perfect competition. The imposition of additional 

regulatory costs tends to widen the gap between price and 

marginal cost in these markets and contributes to additional 

social costs. For more detail see the Regulatory Impact Analysis 

(RIA).

Using the ISIS model, we estimated 12 kilns (9 million tons 

of capacity) may be idled as a result of this final rulemaking. 

ISIS estimates a range of 1,105-1,134 jobs lost associated with 

the capacity idling. In ISIS, kilns are modeled producing at 

 

47 In addition to the ten plants identified that could 

temporarily idle or permanently shut down, there are two plants 

with unusually high mercury emissions that cannot meet the 

mercury emission limit using any single control system. 

However, we are assuming that they will apply multiple controls 

to meet the limit and have accounted for multiple controls in 

our cost analysis. 
Page 282 of 456

their capacity levels after taking into consideration normal 

downtime days. If the kilns owners decide to operate the kilns 

at a lower utilization rate a lower the number of kilns idling 

is expected to be lower. 

As a result of this action, ISIS projects cement industry 

revenues are projected to decline by 4.5 percent, or $421 

million. We estimate cement demand to drop 5.7 percent in 2013 

or 7.0 million tons as a result of this action. The drop in 

demand will affect the domestic production and imports. 

Domestic production may fall by 9.6 percent or 9.0 million tons 

in 2013 compared to the baseline. Imports are likely to rise by

2.0 million tons. ISIS estimates that the average national 

price for Portland cement in 2013 could be 6.8 percent higher, 

or $5.79 per metric ton. More information on this model can be 

found in the ISIS TSD and in a Technical Memo to the docket.

10. What are the benefits?

We estimated the monetized benefits of this final 

regulatory action to be $7.4 billion to $18 billion (2005$, 3 

percent discount rate) in the implementation year (2013). The 

monetized benefits of the final regulatory action at a 7 percent 

discount rate are $6.7 billion to $16 billion (2005$). Using 

alternate relationships between PM2.5 and premature mortality 

supplied by experts, higher and lower benefits estimates are 

plausible, but most of the expert-based estimates fall between 
Page 283 of 456

these two estimates.48 A summary of the avoided health benefits 

and the associated monetized benefits estimates at discount 

rates of 3 percent and 7 percent are provided in Table 13 of 

this preamble. 

Table 13. Summary of the Avoided Health Incidences and 

Monetized PM2.5 Benefits Estimates for the Final Portland Cement 

NESHAP and NSPS

Avoided 

Health 

Incidences

Monetized 

Benefits 

(millions of 

2005$, 3% 

discount 

rate)

Monetized 

Benefits 

(millions of 

2005$, 7% 

discount 

rate)

Avoided Premature 

Mortality

960 to 

2,500

$7,600 to 

$19,000

$6,900 to 

$17,000

Avoided Morbidity

Chronic Bronchitis 650 $19 $19

Acute Myocardial 

Infarction 1,500 $11 $11

Hospital Admissions, 

Respiratory 240 $0.2 $0.2

Hospital Admissions, 

Cardiovascular 500 $0.9 $0.9

Emergency Room Visits, 

Respiratory 1,000 $0.03 $0.03

Acute Bronchitis 1,500 $0.01 $0.01

Work Loss Days 130,000 $1.2 $1.2

Asthma Exacerbation 17,000 $0.06 $0.06

Minor Restricted 

Activity Days 750,000 $3.0 $3.0

Lower Respiratory 

Symptoms 18,000 $0.02 $0.02

Upper Respiratory 

Symptoms 14,000 $0.03 $0.03

1All estimates are for the implementation year (2013), and are 

rounded to two significant figures so numbers may not sum across 

rows. All fine particles are assumed to have equivalent health 

 

48 Roman et al, 2008. Expert Judgment Assessment of the 

Mortality Impact of Changes in Ambient Fine Particulate Matter 

in the U.S. Environ. Sci. Technol., 42, 7, 2268 – 2274.
Page 284 of 456

effects. Benefits from reducing hazardous air pollutants (HAPs) 

are not included. These estimates do not include the energy 

disbenefits of $210 to $470 million. 

 These benefits estimates represent the human health 

benefits associated with reducing exposure to fine particulate 

matter (PM2.5). The PM reductions are the result of emission 

limits on PM as well as emission limits on other pollutants, 

including hazardous air pollutants (HAPs) for the NESHAP and 

criteria pollutants for the NSPS. To estimate the human health 

benefits, we used the environmental Benefits Mapping and 

Analysis Program (BenMAP) model to quantify the changes in PM2.5-

related health impacts and monetized benefits based on changes 

in air quality. This approach is consistent with the recently 

proposed Transport Rule RIA.49

For this final rule, we have expanded and updated the 

analysis since the proposal in several important ways. Using 

the Comprehensive Air Quality Model with extensions (CAMx) 

model, we are able to provide cement sector-specific air quality 

impacts attributable to the emission reductions anticipated from 

this final rule. We believe that this modeling provides a 

superior representation of the geographic distribution of air 

quality impacts than the national average benefit-per-ton 

estimates used for the proposal analysis. Furthermore, CAMx 

 

49 U.S. Environmental Protection Agency, 2010. Proposed RIA for the Transport 

Rule. Prepared by Office of Air and Radiation. June. Available on the 

Internet at http://www.epa.gov/ttn/ecas/ria.html
Page 285 of 456

modeling allows us to model the reduced mercury deposition that 

would occur as a result of the estimated reductions of mercury 

emissions. 

Although we are unable to model mercury methylation and 

human consumption of mercury-contaminated fish, the mercury 

deposition maps provide an improved qualitative characterization 

of the mercury benefits associated with this final rulemaking. 

Lastly, we added qualitative descriptions of the benefits 

categories that we are unable to quantify and monetize,

including the benefits of reducing hazardous air pollutants and 

ecosystem effects. 

In addition, the PM2.5 benefits for this final rulemaking 

reflect EPA‘s current interpretation of the economic literature 

on mortality valuation by using the value‐of‐a-statistical life 

(VSL) based on a meta‐analysis of 26 studies.50 The PM2.5 benefits 

are generally consistent with the methodology used in the 

proposal after adjusting for the revised VSL, and these 

estimates reflect EPA‘s decision to remove the arbitrarily

assumed threshold from the health impact function. 

 

50 In June 2009, EPA‘s Office of Air and Radiation revised the 

VSL used in air regulations to be consistent with the estimate 

used by the rest of the agency. Until updated guidance is 

available, EPA determined that a single peer-reviewed estimate 

applied consistently across the agency best reflects the advice 

it has received.
Page 286 of 456

For these rules the SO2 reductions represent a large 

fraction of the total monetized benefits from reducing PM2.5 , 

but it is not possible to isolate the portion if the total 

monetized benefits attributable to the emission reductions of SO2 

resulting from the application of HCl controls. The benefits 

models assume that all fine particles, regardless of their 

chemical composition, are equally potent in causing premature 

mortality because there is no clear scientific evidence that 

would support the development of differential effects estimates 

by particle type.

For context, it is important to note that the magnitude of 

the PM2.5 benefits is largely driven by the concentration response 

function for premature mortality. Experts have advised EPA to 

consider a variety of assumptions, including estimates based 

both on empirical (epidemiological) studies and judgments 

elicited from scientific experts, to characterize the 

uncertainty in the relationship between PM2.5 concentrations and 

premature mortality. For this final rulemaking we cite two key 

empirical studies, one based on the American Cancer Society 

cohort study51 and the extended Six Cities cohort study52. 

 

51 Pope et al, 2002. ―Lung Cancer, Cardiopulmonary Mortality, 

and Long-term Exposure to Fine Particulate Air Pollution.‖ 

Journal of the American Medical Association 287:1132-1141

52 Laden et al, 2006. ―Reduction in Fine Particulate Air 

Pollution and Mortality.‖ American Journal of Respiratory and 

Critical Care Medicine. 173: 667-672
Page 287 of 456

Alternate models identified by experts describing the 

relationship between PM2.5 and premature mortality would yield 

higher and lower estimates depending upon the assumptions that 

they made, but most of the expert-based estimates fall between 

the two epidemiology-based estimates (Roman et al. 2008). 

EPA strives to use the best available science to support our 

benefits analyses. We recognize that interpretation of the 

science regarding air pollution and health is dynamic and 

evolving. The question of whether or not to assume a threshold 

in calculating the benefits associated with reductions in PM2.5 is 

an issue that affects the benefits calculations not only for 

this rule but for many other EPA rulemakings and analyses. Due 

to these implications, we solicited comment on appropriateness 

of both the no-threshold and threshold model for PM benefits 

analysis as part of the proposal of this rule. 

Three commenters did not support adopting a no-threshold 

model because it would obscure the greater uncertainty 

associated with calculated premature mortality at low PM 

concentrations and because it would be premature prior to the 

conclusion of the PM NAAQS review. 

Shortly after the end of the comment period, EPA finalized 

the Integrated Science Assessment for Particulate Matter53, which 

 

53 U.S. Environmental Protection Agency (U.S. EPA). 2009. 

Integrated Science Assessment for Particulate Matter (Final 
Page 288 of 456

was reviewed twice by EPA‘s Clean Air Scientific Advisory 

Committee, and concluded that the scientific literature 

consistently finds that a no-threshold log-linear model most 

adequately portrays the PM-mortality concentration-response 

relationship while recognizing potential uncertainty about the 

exact shape of the concentration-response function. In 

addition, the Human Health Subcommittee of EPA‘s Science 

Advisory Board recently concluded, ―The HES fully supports EPA‘s 

decision to use a no-threshold model to estimate mortality 

reductions. This decision is supported by the data, which are 

quite consistent in showing effects down to the lowest measured 

levels. Analyses of cohorts using data from more recent years, 

during which time PM concentrations have fallen, continue to 

report strong associations with mortality. Therefore, there is 

no evidence to support a truncation of the CRF [concentrationresponse function].‖54 

After reviewing the public comments in conjunction with our 

review of the scientific literature and the Science Advisory 

Board‘s comments, we have determined that the no-threshold model 

 

Report). EPA-600-R-08-139F. National Center for Environmental 

Assessment – RTP Division. December. Available on the Internet 

at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=216546.

54 U.S. Environmental Protection Agency - Science Advisory Board 

(U.S. EPA-SAB). 2010. Review of EPA‘s DRAFT Health Benefits of 

the Second Section 812 Prospective Study of the Clean Air Act. 

EPA-COUNCIL-10-001. June. Available on the Internet at 

<http://yosemite.epa.gov/sab/sabproduct.nsf/0/72D4EFA39E48CDB285

25774500738776/$File/EPA-COUNCIL-10-001-unsigned.pdf>.
Page 289 of 456

is the most appropriate model for assessing the mortality 

benefits associated with reducing PM2.5 exposure. Consistent with 

this recent scientific advice, we are replacing the previous 

threshold sensitivity analysis with a new ―Lowest Measured 

Level‖ (LML) assessment. While an LML assessment provides some 

insight into the level of uncertainty in the estimated PM 

mortality benefits, EPA does not view the LML as a threshold and 

continues to quantify PM-related mortality impacts using a full 

range of modeled air quality concentrations.

Most of the estimated PM-related benefits in this rule 

accrue to populations exposed to higher levels of PM2.5. Using 

the Pope et al. (2002) study, about 94 percent occur among 

populations with baseline exposure to annual mean PM2.5 levels at 

or above 7.5 μg/m3. Using the Laden et al. (2006) study, about 

58 percent occur among populations with baseline exposure to 

annual mean PM2.5 levels at or above 10 μg/m3.

 It is important to 

emphasize that we have high confidence in PM2.5-related effects 

down to the lowest LML of the major cohort studies. This fact 

is important, because as we estimate PM-related mortality among 

populations exposed to levels of PM2.5 that are successively 

lower, our confidence in the results diminishes. However, our 

analysis shows that the great majority of the impacts occur at 

higher exposures.
Page 290 of 456

It should be emphasized that the monetized benefits 

estimates provided above do not include benefits from several 

important benefit categories, including reducing other air 

pollutants, ecosystem effects, and visibility impairment. The 

benefits from reducing other pollutants have not been monetized 

in this analysis, including reducing 4,400 tons of NOx, 5,800 

tons of hydrochloric acid, 5,200 tons of organic HAPS, and over 

16,000 pounds of mercury each year. In addition, we were unable 

to quantify the additional emission reductions that would occur 

if cement facilities temporarily idle or reduce capacity 

utilization as a result of this regulation, or the 

unquantifiable amount of reductions in condensable PM. Although 

we do not have sufficient information or modeling available to 

provide monetized estimates for this rulemaking, we include a 

qualitative assessment of the health effects of these air 

pollutants in the RIA for this rule, which is available in the 

docket.

In addition, the monetized benefits estimates provided in 

Table 13 do not reflect the disbenefits associated with 

increased electricity usage from operation of the control 

devices. We estimate that the increases in emissions of NOx, 

SO2, PM, and CO2 would have disbenefits valued at $210 million to 

$470 million at a 3% discount rate. The total monetized 

benefits estimates of $7.4 billion to $18 billion (2005$, 3 
Page 291 of 456

percent discount rate) and $6.7 billion to $17 billion (2005$, 

7% discount rate) reflect these energy disbenefits. 

This analysis does not include the type of detailed 

uncertainty assessment found in the 2006 PM2.5 NAAQS RIA or 2008 

Ozone NAAQS RIA. However, the benefits analyses in these RIAs 

provide an indication of the sensitivity of our results to 

various assumptions, including the use of alternative 

concentration-response functions and the fraction of mortality 

impacts at low PM2.5 levels. 

The social costs of this rulemaking are estimated at $880 

million (2005$) in the year of full implementation, and the 

benefits are estimated at $7.4 billion to $18 billion (2005$, 3 

percent discount rate) for that same year. The benefits at a 7 

percent discount rate are $6.7 billion to $16 billion (2005$). 

Thus, net benefits of this rulemaking are estimated at $6.5

billion to $17 billion (2005$, 3 percent discount rate). The net 

benefits at a 7 percent discount rate are $5.8 billion to $16 

billion (2005$). Using alternate relationships between PM2.5 and 

premature mortality supplied by experts, higher and lower 

benefits estimates are plausible, but most of the expert-based 

estimates fall between these two estimates. EPA believes that 

the benefits are likely to exceed the costs by a significant 

margin even when taking into account the uncertainties in the 

cost and benefit estimates. 
Page 292 of 456

A final issue on benefits concerns the air impacts of 

increases in imports. When a regulation leads to increases in 

imports and only the domestic emission changes are considered in 

a benefit analysis, the question of the impact of emissions from 

the increased production in other countries should be examined. 

The extra emissions may have an impact on the regulating country 

(the US) and other the countries. The location of these extra 

emissions and the pollutants involved are both important. Our 

economic modeling does not involve estimates of the origin of 

the imports. We also do not have information about the level of 

control for facilities in other countries. Thus, estimating 

disbenefits associated with these increased emissions in other 

countries was beyond what we were able to do in this analysis.

However, another limitation of our analysis produces a bias 

in the opposite direction. The economic impact analysis 

estimated a 10 million ton decrease in domestic production. No 

emission reductions were estimated as a result of this change in 

production. The benefit analysis was based on emission 

reductions associated with control being applied to all 

facilities with no change in capacity utilization. The increase 

in imports was estimated to be 3 million tons. Thus we omitted 

an emission reduction associated with a 10 million ton decrease 

in production in this country while also omitting an increase in 

emissions for an increase in production in other countries of 
Page 293 of 456

less than a third of the domestic decrease. Of course the net 

result of these two omissions depends on the relative emission 

rates of the countries involved. Analysis of benefits for either 

of these two types of emissions is beyond the current scope of 

the benefit analysis.

For more information, please refer to the RIA for this 

final rule that is available in the docket.

VII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

Under section 3(f)(1) of Executive Order 12866 (58 FR 

51735, October 4, 1993), this action is an ―economically 

significant regulatory action‖ because it is likely to have an 

annual effect on the economy of $100 million or more. 

Accordingly, EPA submitted this action to the Office of 

Management and Budget (OMB) for review under EO 12866 and any 

changes made in response to OMB recommendations have been 

documented in the docket for this action. In addition, EPA 

prepared a Regulatory Impact Analysis (RIA) of the potential 

costs and benefits associated with this action. 

When estimating the PM2.5-related human health benefits and 

compliance costs in Table 14 below, EPA applied methods and 

assumptions consistent with the state-of-the-science for human 

health impact assessment, economics and air quality analysis. 

EPA applied its best professional judgment in performing this 
Page 294 of 456

analysis and believes that these estimates provide a reasonable 

indication of the expected benefits and costs to the nation of 

this rule. The Regulatory Impacts Analysis (RIA) available in 

the docket describes in detail the empirical basis for EPA's 

assumptions and characterizes the various sources of 

uncertainties affecting the estimates below. 

When characterizing uncertainty in the PM-mortality 

relationship, EPA has historically presented a sensitivity 

analysis applying alternate assumed thresholds in the PM 

concentration-response relationship. In its synthesis of the 

current state of the PM science, EPA‘s 2009 Integrated Science 

Assessment (ISA) for Particulate Matter concluded that a nothreshold log-linear model most adequately portrays the PMmortality concentration-response relationship. In the RIA 

accompanying this rule, rather than segmenting out impacts 

predicted to be associated levels above and below a  ̳bright 

line‘ threshold, EPA includes a ―lowest-measured-level (LML)‖ 

that illustrates the increasing uncertainty that characterizes 

exposure attributed to levels of PM2.5 below the LML for each 

study. Figures provided in the RIA show avoided PM mortality 

impacts predicted relative to the baseline PM2.5 levels 

experienced by the population receiving the PM2.5 mortality 

benefit, as well as the lowest air quality levels measured in 

each of the epidemiology cohort studies. This information 
Page 295 of 456

allows readers to determine the portion of PM-related mortality 

benefits occurring above or below the LML of each study; in 

general, our confidence in the size of the estimated reduction 

PM2.5-related premature mortality decreases in areas where annual 

mean PM2.5 levels are further below the LML in the cohort 

studies. Using the Pope et al. (2002) study, about 94 percent 

occur among populations with baseline exposure to annual mean 

PM2.5 levels at or above 7.5 μg/m3. Using the Laden et al. (2006) 

study, about 58 percent occur among populations with baseline 

exposure to annual mean PM2.5 levels at or above 10 μg/m3. While 

the LML analysis provides some insight into the level of 

uncertainty in the estimated PM mortality benefits, EPA does not 

view the LML as a threshold and continues to quantify PM-related 

mortality impacts using a full range of modeled air quality 

concentrations.

Table 14 shows the results of the cost and benefits 

analysis for this rule. 

Table 14. Summary of the Monetized Benefits, Social Costs, and 

Net Benefits for the final Portland Cement NESHAP and NSPS in 

2013(millions of 2005$)1

Final NESHAP and NSPS 

3% Discount Rate 7% Discount Rate

Total Monetized 

Benefits2 $7,400 to $18,000 $6,700 to $16,000

Total Social Costs3 $880 $880

Net Benefits $6,500 to $17,000 $5,800 to $16,000

Non-monetized 

Benefits

4,400 tons of NOx (includes energy 

disbenefits)

5,200 tons of organic HAPs

5,900 tons of HCl
Page 296 of 456

16,400 pounds of mercury 

Health effects from HAPs, NO2, and SO2

exposure

Ecosystem effects

Visibility impairment

Final NSPS only

3% Discount Rate 7% Discount Rate

Total Monetized 

Benefits2 $510 to $1,300 $460 to $1,100

Total Social Costs3 $40 $40

Net Benefits $470 to $1,300 $420 to $1,100

Non-monetized 

Benefits

6,600 tons of NOx

520 tons of HCl

Health effects from HAPs, NO2, and SO2

exposure

Ecosystem effects

Visibility impairment

Final NESHAP only

3% Discount Rate 7% Discount Rate

Total Monetized 

Benefits2 $7,400 to $18,000 $6,700 to $16,000

Total Social Costs3 $869 $869

Net Benefits $6,500 to $17,000 $5,800 to $16,000

Non-monetized 

Benefits

5,200 tons of organic HAPs

5,900 tons of HCl

16,000 pounds of mercury 

Health effects from HAPs, SO2 exposure

Ecosystem effects

Visibility impairment

Alternative: More Stringent NSPS and Final NESHAP

3% Discount Rate 7% Discount Rate

Total Monetized 

Benefits2 $7,400 to $18,000 $6,700 to $16,000

Total Social Costs3 $896 $896

Net Benefits $6,500 to $17,000 $5,800 to $16,000

Non-monetized 

Benefits

7,800 tons of NOx (includes energy 

disbenefits)

5,200 tons of organic HAPs

5,900 tons of HCl

16,400 pounds of mercury 

Health effects from HAPs, NO2, and SO2

exposure

Ecosystem effects

Visibility impairment

1All estimates are for the implementation year (2013), and are 

rounded to two significant figures. 
Page 297 of 456

2 The total monetized benefits reflect the human health benefits 

associated with reducing exposure to PM2.5 through reductions of 

directly emitted PM2.5 and PM2.5 precursors such as NOx and SO2. It 

is important to note that the monetized benefits include many 

but not all health effects associated with PM2.5 exposure. 

Benefits are shown as a range from Pope et al. (2002) to Laden 

et al. (2006). These models assume that all fine particles, 

regardless of their chemical composition, are equally potent in 

causing premature mortality because there is no clear scientific 

evidence that would support the development of differential 

effects estimates by particle type. The total monetized benefits 

include the energy disbenefits.

3 The methodology used to estimate social costs for one year in 

the multimarket model using surplus changes results in the same 

social costs for both discount rates.

For more information on the benefits analysis, please refer 

to the RIA for this rulemaking, which is available in the 

docket.

B. Paperwork Reduction Act

1. Subpart F

The information requirements in the final amendments to 

subpart F 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 

2307.02.

The final amendments to the NSPS for Portland cement plants 

apply to affected facilities constructed, modified, or 

reconstructed after June 16, 2008. The owner or operator of a 

new kiln is required to keep daily records of clinker 
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production, install and operate 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 2,559 

labor-hours per year at a cost of $240,064 per year. The 

annualized capital costs are estimated at $45,626 per year and 

operation and maintenance costs are estimated at $52,450 per 

year. Burden is defined at 5 CFR 1320.3(b).

2. Subpart LLL

The information collection requirements in this final rule 

have been submitted for approval to the OMB under the Paperwork 

Reduction Act, 44 U.S.C. 3501 et seq. The Information 

Collection Request (ICR) document prepared by EPA has been 

assigned EPA ICR number 1801.09.
Page 299 of 456

In most cases, new and existing kilns and in-line kiln/raw 

mills at major and area sources that are not already subject to 

emission limits for THC, mercury, and PM will become subject to 

the limits and associated compliance provisions in the current 

rule. New compliance provisions for mercury will remove the 

current requirement for an initial performance test coupled with 

monitoring of the carbon injection rate. Instead, plants will 

measure mercury emissions by calculating a 30-day average from 

continuous or integrated monitors. Records of all calculations 

and data will be required. New compliance procedures will also 

apply to area sources subject to a PM limit in a format of 

lbs/ton of clinker. The owner or operator will be required to 

install and operate a weight measurement system and keep daily 

records of clinker production instead of the current requirement 

to install and operate a PM CEMS. Cement plants also will be 

subject to new limits for HCl and associated compliance 

provisions which include compliance tests using EPA Method 321 

and continuous monitoring for HCl for facilities that do not use 

a wet scrubber for HCl control. These requirements are based on 

the recordkeeping and reporting requirements in the NESHAP 

General Provisions (40 CFR part 63, subpart A) which are 

mandatory for all operators subject to national emission 

standards. These recordkeeping and reporting requirements are 

specifically authorized by section 114 of the CAA (42 U.S.C. 
Page 300 of 456

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 65,506 

labor-hours per year at a cost of $6.4 million per year. The 

average annualized capital costs are estimated at $65.5 million 

per year and average operation and maintenance costs are 

estimated at $199,378 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.

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. 

Small entities include small businesses, small organizations, 

and small governmental jurisdictions.
Page 301 of 456

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 depending on 

the size definition for the affected NAICS code (as defined by 

Small Business Administration (SBA) size standards found at 

http://www.sba.gov/idc/groups/public/documents/sba_homepage/serv

_sstd_tablepdf.pdf); (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.

1. Subpart F

After considering the economic impact of this final 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 3 of the 26 existing Portland cement 

entities are small entities which will not incur any impacts 

under these final amendments unless an affected facility is 

constructed, modified, or reconstructed. Based on our economic 

analysis, 7 new kilns may be constructed during the next five 

years that will be subject to these NSPS amendments. One of 

these kilns may be operated by a Portland cement entity that is 

classified as a small entity according to the SBA small business 
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size standards. Of these 7 kilns, this small entity is expected 

to incur an annualized compliance cost of between 1.0 and 3.0 

percent of sales to comply with the final action. 

Although this final 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 the selection of an 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 sources from the least 

stringent requirement thereby eliminated overlapping monitoring, 

testing and reporting requirements by requiring that the source 

comply with only the more stringent of the standards. 

2. Subpart LLL

After considering the economic impact of this final 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 3 of the 26 existing Portland

cement plants are small entities. 

EPA performed a screening analysis for impacts on the three 

affected small entities by comparing compliance costs to entity 

revenues. EPA‘s analysis found that the ratio of compliance cost 

to company revenue for one small entity (a tribal government) 
Page 303 of 456

will have an annualized cost of less than 1 percent of sales. 

The other two small businesses will have an annualized cost of 

between 1 and three percent of sales.

Although this final rule will not impact a substantial 

number of small entities, EPA nonetheless has tried to reduce 

the impact of this proposed rule on small entities by setting 

the final emissions limits at the MACT floor, the least 

stringent level allowed by law. In the case where there are 

overlapping standards between this NESHAP and the Portland 

Cement NSPS, we have exempted sources from the least stringent 

requirement thereby eliminating the overlapping monitoring, 

testing and reporting requirements by requiring that the source 

comply with only the more stringent of the standards. In 

addition, we applied MACT for HCl emissions to major sources 

only. The reduced compliance costs for two of the three small 

entities by a factor of 4. 

D. Unfunded Mandates Reform Act

Title II of the Unfunded Mandates Reform Act (UMRA), 2 

U.S.C 1531-1538, requires Federal agencies, unless otherwise 

prohibited by law, to assess the effects of their regulatory 

actions on State, local, and tribal governments and the private 

sector. Federal agencies must also develop a plan to provide 

notice to small governments that might be significantly or 

uniquely affected by any regulatory requirements. The plan must 
Page 304 of 456

enable officials of affected small governments to have 

meaningful and timely input in the development of EPA regulatory 

proposals with significant Federal intergovernmental mandates 

and must inform, educate, and advise small governments on 

compliance with the regulatory requirements.

1. Subpart F

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 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 final rule is 

not subject to the requirements of section 202 and 205 of the 

UMRA. 

This final action is also not subject to the requirements 

of section 203 of the UMRA because it contains no regulatory 

requirements that might significantly or uniquely affect small 

governments. This final action contains no requirements that 

apply to such governments, imposes no obligations upon them, and 

will not result in expenditures by them of $100 million or more 

in any one year or any disproportionate impacts on them. 

2. Subpart LLL

This rule contains a Federal mandate that may result in 

expenditures of $100 million or more for State, local, and 
Page 305 of 456

tribal governments, in the aggregate, or the private sector in 

any one year. Accordingly, EPA has prepared under section 202 

of the UMRA a written statement which is summarized below. 

In developing this rule, EPA consulted with small 

governments under a plan developed pursuant to section 203 of 

UMRA concerning the regulatory requirements in the rule that 

might significantly or uniquely affect small governments. EPA 

has determined that this final action contains regulatory 

requirements that might significantly or uniquely affect small 

governments because we identified one of the facilities affected 

by the final rule as tribally owned. EPA developed a plan to 

permit this tribal entity to have meaningful and timely input 

into its development.

Consistent with the intergovernmental consultation 

provisions of section 204 of the UMRA, EPA initiated 

consultations with the governmental entities affected by this 

rule. EPA directly contacted the facility in question to insure 

it was appraised of this rulemaking and potential implications. 

This facility indicated it was aware of the rulemaking and was 

participating in meetings with the industry trade association 

concerning this rulemaking. The facility did not indicate any 

special issues other than those expressed by the industry in 

general, We are assuming that they have the same concerns as 

those expressed by the other non-tribally owned facilities 
Page 306 of 456

during the development of this final rule. Subsequent to 

proposal, EPA again contacted the Tribal Government by letter 

with an offer of consultation. We received no response to that 

letter. 

Consistent with section 205, EPA has identified and 

considered a reasonable number of regulatory alternatives. EPA 

carefully examined regulatory alternatives, and selected the 

lowest cost/least burdensome alternative that EPA deems adequate 

to address Congressional concerns and to effectively reduce 

emissions of mercury, THC and PM. EPA has considered the costs 

and benefits of the final rule, and has concluded that the costs 

will fall mainly on the private sector (approximately $479 

million). EPA estimates that an additional facility owned by a 

tribal government will incur approximately $1.2 million in costs 

per year. Furthermore, we believe it is unlikely that State, 

local and Tribal governments would begin operating large 

industrial facilities, similar to those affected by this 

rulemaking operated by the private sector. EPA has selected 

regulatory alternatives that represent the MACT floor level of 

control, which is the least stringent level allowed by law. 

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 
Page 307 of 456

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.‖

These two final rules do not have federalism implications. 

They 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 these final rules.

F. Executive Order 13175: Consultation and Coordination with 

Indian Tribal Governments

Subject to the Executive Order 13175 (65 FR 67249, November 

9, 2000) EPA may not issue a regulation that has tribal 

implications, that imposes substantial direct compliance costs, 

and that is not required by statute, unless the Federal 

government provides the funds necessary to pay the direct 

compliance costs incurred by tribal governments, or EPA consults 

with tribal officials early in the process of developing the 
Page 308 of 456

proposed regulation and develops a tribal summary impact 

statement.

1.Subpart F

This final action does not have tribal implications, as 

specified in Executive Order 13175 (65 FR 67249, November 9, 

2000). 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 between the Federal government and Indian 

tribes, as specified in Executive Order 13175. The final rule 

imposes requirements on owners and operators of specified 

industrial facilities and not tribal governments. The only 

tribally owned source is not affected by the amendments to 

subpart F. Thus, Executive Order 13175 does not apply to this 

action. 

2.Subpart LLL

EPA has concluded that this action will have tribal 

implications, because it will impose substantial direct 

compliance costs on tribal governments, and the Federal 

government will not provide the funds necessary to pay those 

costs. One of the facilities affected by this final rule is 

tribally owned. We estimate this facility will incur direct 

compliance costs that are between 1 to 3 percent of sales. 
Page 309 of 456

Accordingly, EPA provides the following tribal summary impact 

statement as required by section 5(b). 

EPA consulted with tribal officials early in the process of 

developing this regulation to provide them meaningful and timely 

input into its development. EPA directly contacted the facility 

in question to insure it was appraised of this rulemaking and 

potential implications. This facility indicated it was aware of 

the rulemaking and was participating in meetings with the 

industry trade association concerning this rulemaking. The 

facility did not indicate any specific concern, and we are 

assuming that they have the same concerns as those expresses by 

the other non-tribally owned facilities during the development 

of this proposed rule. 

G. Executive Order 13045: Protection of Children from 

Environmental Health Risks and Safety Risks

EPA interprets Executive Order 13045 (62 FR 19885, April 

23, 1997) as applying to those regulatory actions that concern 

health or safety risks, such that the analysis required under 

section 5-501 of the Executive 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
Page 310 of 456

This proposed rule is not a ―significant energy action‖ as 

defined in Executive Order 13211, (66 FR 28355, May 22, 2001) 

because it is not likely to have a significant adverse effect on 

the supply, distribution, or use of energy. Further, we have 

concluded that this proposed rule is not likely to have any 

adverse energy effects. This proposal will result in the 

addition of control equipment and monitoring systems for 

existing and new sources.

The final rule under subpart F 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 2013.

We estimate that under the final subpart LLL rule the 

additional electrical demand will be 784 million kWhr per year

and the natural gas use will be 672 million cubic feet for 

existing sources. At the end of 2013, electrical demand from 

new sources will be 180 million kWhr per year and natural gas 

use will be 171 million cubic feet.

I. National Technology Transfer and Advancement Act

Section 12(d) of the National Technology Transfer and 

Advancement Act of 1995 (―NTTAA‖), Public Law No. 104-113 (15 

U.S.C. 272 note) directs EPA to use voluntary consensus 

standards (VCS) in its regulatory activities unless to do so 
Page 311 of 456

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. 

Consistent with the NTTAA, EPA conducted searches through 

the Enhanced NSSN Database managed by the American National 

Standards Institute (ANSI). We also contacted VCS 

organizations, and accessed and searched their databases. 

1. Subpart F

This final rulemaking involves technical standards. EPA 

has decided 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. 

While the Agency has identified 12 other 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 
Page 312 of 456

standards cited in this rule. See the docket for this rule for 

the reasons for these determinations. 

2. Subpart LLL

This final rulemaking involves technical standards. EPA 

will use ASTM D6348-03, ―Determination of Gaseous Compounds by 

Extractive Direct Interface Fourier Transform (FTIR) 

Spectroscopy,‖ as an acceptable alternative to EPA Method 320

providing the following conditions are met:

(1) The test plan preparation and implementation in the 

Annexes to ASTM D 6348-03, Sections A1 through A8 are mandatory;

(2) In ASTM D6348-03 Annex A5 (Analyte Spiking Technique), 

the percent R must be determined for each target analyte 

(Equation A5.5). In order for the test data to be acceptable 

for a compound, percent R must be 70<R<130. If the percent R 

value does not meet this criterion for a target compound, the 

test data is not acceptable for that compound and the test must 

be repeated for that analyte (i.e., the sampling and/or 

analytical procedure should be adjusted before a retest). The 

%R value for each compound must be reported in the test report, 

and all field measurements must be corrected with the calculated 

%R value for that compound by using the following equation: 

Reported Result = Measured Concentration in the Stack x 100  % 

R. 
Page 313 of 456

While the Agency has identified eight other 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 and 

63.7 (f) of the NESHAP 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.

J. Executive Order 12898: Federal Actions to Address 

Environmental Justice in Minority Populations and Low-Income 

Populations

Executive Order (EO) 12898 (59 FR 7629)(February 16, 1994) 

establishes federal executive policy on environmental justice. 

Its main provision directs Federal agencies, to the greatest 

extent practicable and permitted by law, to make environmental 

justice part of their mission by identifying and addressing, as 

appropriate, disproportionately high and adverse human health or 

environmental effects of their programs, policies, and 

activities on minority populations and low-income populations in 

the United States.
Page 314 of 456

EPA has determined that this proposed rule will not have 

disproportionately high and adverse human health or 

environmental effects on minority or low-income populations 

because it increases 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 populations. 

Additionally, the Agency has reviewed this proposed rule to 

determine if there was existing disproportionately high and 

adverse human health or environmental effects on minority or 

low-income populations that could be mitigated by this 

rulemaking. An analysis of demographic data showed that the 

average of populations in close proximity to the sources, and 

thus most likely to be effected by the sources, were similar in 

demographic composition to national averages. 

In determining the aggregate demographic makeup of the 

communities near affected sources, EPA used census data at the 

block group level to identify demographics of the populations 

considered to be living near affected sources, such that they 

have notable exposures to current emissions from these sources. 

In this approach, EPA reviewed the distributions of different 

socio-demographic groups in the locations of the expected 

emission reductions from this rule. The review identified those 

census block groups within a circular distance of a half, 3, and 
Page 315 of 456

5 miles of affected sources and determined the demographic and 

socio-economic composition (e.g., race, income, education, etc.) 

of these census block groups. The radius of 3 miles (or 

approximately 5 kilometers) has been used in other demographic 

analyses focused on areas around potential sources.55,

56,57,58 

EPA‘s demographic analysis has shown that these areas in 

aggregate have similar proportions of American Indians, AfricanAmericans, Hispanics, Whites, and ―Other and Multi-racial‖ 

populations, and similar proportions of families with incomes 

below the poverty level as the national average.59 

EPA defines ―Environmental Justice‖ to include meaningful 

involvement of all people regardless of race, color, national 

origin, or income with respect to the development, 

implementation, and enforcement of environmental laws, 

regulations, and polices. To promote meaningful involvement, 

EPA has developed a communication and outreach strategy to 

ensure that interested communities have access to this proposed 

rule, are aware of its content, and have an opportunity to 

 

55 U.S. GAO (Government Accountability Office). Demographics of People Living 

Near Waste Facilities. Washington DC: Government Printing Office; 1995.

56 Mohai P, Saha R. ―Reassessing Racial and Socio-economic Disparities in 

Environmental Justice Research‖. Demography. 2006;43(2): 383–399.

57 Mennis J. ―Using Geographic Information Systems to Create and Analyze 

Statistical Surfaces of Populations and Risk for Environmental Justice 

Analysis‖. Social Science Quarterly, 2002;83(1):281-297.

58 Bullard RD, Mohai P, Wright B, Saha R, et al. Toxic Waste and Race at Twenty 

1987-2007. United Church of Christ. March, 2007. 

59 The results of the demographic analysis are presented in ―Review of 

Environmental Justice Impacts‖, June 2010, a copy of which is available in 

the docket. 
Page 316 of 456

comment during the comment period. During the comment period, 

EPA will publicize the rulemaking via EJ newsletters, Tribal 

newsletters, EJ listservs, and the Internet, including the 

Office of Policy, Economics, and Innovation‘s Rulemaking Gateway 

Web site (http://yosemite.epa.gov/opei/RuleGate.nsf/). EPA will 

also provide general rulemaking fact sheets (e.g., why is this 

important for my community) for EJ community groups and conduct 

conference calls with interested communities. In addition, 

state and federal permitting requirements will provide state and 

local governments and members of affected communities the 

opportunity to provide comments on the permit conditions 

associated with permitting the sources affected by this 

rulemaking.

This final action establishes national emission standards 

for new and existing cement kilns. EPA estimates that there are 

approximately 93 facilities covered by this rule. The final 

rule will reduce emissions of all the listed Hazardous Air 

Pollutants emitted from this source category. This includes 

emissions of cadmium, HCl, lead, Hg, and organic hazardous air 

pollutants. Adverse health effects from these pollutants 

include cancer, irritation of the lungs, skin, and mucus 

membranes, effects on the central nervous system, and damage to 

the kidneys, and acute health disorders. The rule will also 

result in substantial reductions of criteria pollutants such as 
Page 317 of 456

NOx, PM (total and fine), SO2. SO2 and NO2 are precursors for 

the formation of PM2.5 and ozone. Reducing these emissions will 

reduce ozone and PM2.5 formation and associated health effects, 

such as adult premature mortality, chronic and acute bronchitis, 

asthma, and other respiratory and cardiovascular diseases. 

(Please refer to the RIA contained in the docket for this 

rulemaking.) 

K. Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as 

added by the Small Business Regulatory Enforcement Fairness Act 

of 1996, generally provides that before a rule may take effect, 

the agency promulgating the rule must submit a rule report, 

which includes a copy of the rule, to each House of the Congress 

and to the Comptroller General of the United States. EPA will 

submit a report containing this rule and other required 

information to the U.S. Senate, the U.S. House of 

Representatives, and the Comptroller General of the United 

States prior to publication of the rule in the Federal Register. 

A major rule cannot take effect until 60 days after it is 

published in the Federal Register. This action is a ―major rule‖ 

as defined by 5 U.S.C. 804(2). These final rules will be 

effective [INSERT DATE 60 DAYS FROM PUBLICATION IN THE FEDERAL 

REGISTER.
Standards of Performance for Portland Cement Plants and National

Emission Standards for Hazardous Air Pollutants From the 

Portland Cement Manufacturing Industry

Page 318 of 456

List of Subjects in 40 CFR Part 9

Environmental protection, Reporting and recordkeeping.

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, Administrative practice and procedure, 

Air pollution control, Hazardous substances, and Reporting and 

recordkeeping requirements.

.

Dated:

Lisa P. Jackson,

Administrator.
Page 319 of 456

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: 23 U.S.C. 101; 42 U.S.C. 7401-7671q.

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 

§60.56c(b)(4) of subpart Ec, §60.63(f)(2) and (f)(4) of subpart 

F, §60.106(e)(2) of subpart J, §§60.104a(d)(3), (d)(5), (d)(6), 

(h)(3), (h)(4), (h)(5), (i)(3), (i)(4), (i)(5), (j)(3), and 

(j)(4), 60.105a(d)(4), (f)(2), (f)(4), (g)(2), and (g)(4), 

60.106a(a)(1)(iii), (a)(2)(iii), (a)(2)(v), (a)(2)(viii), 

(a)(3)(ii), and (a)(3)(v), and 60.107a(a)(1)(ii), (a)(1)(iv), 

(a)(2)(ii), (c)(2), (c)(4), and (d)(2) of subpart Ja, tables 1 

and 3 of subpart EEEE, tables 2 and 4 of subpart FFFF, table 2 
Page 320 of 456

of subpart JJJJ, and §§60.4415(a)(2) and 60.4415(a)(3) of 

subpart KKKK of this part.

* * * * *

Subpart F--[AMENDED]

3. Section 60.62 is amended to read as follows:

§60.62 Standards.

a) On and after the date on which the performance test 

required to be conducted by §60.8 is completed, you may not 

discharge into the atmosphere from any kiln any gases which: 

(1) Contain particulate matter (PM) in excess of:

(i) 0.30 lb per ton of feed (dry basis) to the kiln (if 

construction, reconstruction, or modification of the kiln 

commences after August 17, 1971 but on or before June 16, 2008.)

(ii) 0.01 pound per ton of clinker if construction, 

reconstruction, or modification of the kiln commenced after June 

16, 2008.

(2) Exhibit greater than 20 percent opacity., except that 

this opacity limit does not apply to any kiln subject to a PM 

limit in paragraph (a)(1) of this section that uses 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 June 
Page 321 of 456

16, 2008, except this limit does not apply to any alkali bypass 

installed on the kiln.

(4) Exceed sulfur dioxide (SO2) levels of 0.4 pounds per 

ton of clinker on a 30-day rolling average; from a kiln for 

which construction, reconstruction, or modification commences 

after June 16, 2008, unless you are demonstrating a 90 percent 

SO2 emissions reduction measured across the SO2 control device. 

(b) On and after the date on which the performance test 

required to be conducted by §60.8 is completed, you may not 

discharge into the atmosphere from any clinker cooler any gases 

which: 

(1) Contain PM in excess of:

(i) 0.10 lb per ton of feed (dry basis) to the kiln if 

construction, reconstruction, or modification of the clinker 

cooler commenced after August 17, 1971 but on or before June 16, 

2008.

(ii) 0.01 pound per ton of clinker if construction, 

reconstruction, or modification of the clinker cooler commences 

after June 16, 2008.

(2) Exhibit 10 percent opacity, or greater, except that 

this opacity limit does not apply to any clinker cooler subject 

to a PM limit in paragraph (b)(1) of this section that uses a PM 

continuous emissions monitoring system.
Page 322 of 456

(3) If the kiln and clinker cooler exhaust are combined 

for energy efficiency purposes and sent to a single control 

device, the appropriate kiln PM limit may be adjusted using the 

procedures in §63.1343(b) to this part.

(4) If the kiln has a separate alkali bypass stack, you 

must combine the PM emissions from the bypass stack with the PM 

emissions from the main kiln exhaust to determine total PM 

emissions.

(c) On and after the date on which the performance test 

required to be conducted by §60.8 is completed, you may not 

discharge into the atmosphere from any affected facility other 

than the kiln and clinker cooler any gases which exhibit 10 

percent opacity, or greater. 

(d) If you have an affected source subject to this 

subpart with a different emission limit or requirement for the 

same pollutant under another regulation in title 40 of this 

chapter, you must comply with the most stringent emission limit 

or requirement and are not subject to the less stringent 

requirement. 

4. Section 60.63 is amended to read as follows:

§60.63 Monitoring of operations.

(a) Reserved
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(b) Clinker Production Monitoring Requirements. For any 

kiln subject to an emissions limitation on particulate matter, 

NOx, or SO2 emissions (lb/ton of clinker), you must

(1) Determine hourly clinker production by one of two 

methods:

(i) Install, calibrate, maintain, and operate a permanent 

weigh scale system to measure and record weight rates in tonsmass per hour of the amount of clinker produced. The system of 

measuring hourly clinker production must be maintained within ±5 

percent accuracy. 

(ii) Install, calibrate, maintain, and operate a permanent 

weigh scale system to measure and record weight rates in tonsmass per hour of the amount of feed to the kiln. The system of 

measuring feed must be maintained within ±5 percent accuracy. 

Calculate your hourly clinker production rate using a kiln 

specific feed to clinker ratio based on reconciled clinker 

production determined for accounting purposes and recorded feed 

rates. This ratio should be updated monthly. Note that if this 

ratio changes at clinker reconciliation, you must use the new 

ratio going forward, but you do not have to retroactively change 

clinker production rates previously estimated. 

(2) You must determine, record, and maintain a record of 

the accuracy of the system of measuring hourly clinker or feed 

production before initial use (for new sources) or within 30 
Page 324 of 456

days of the effective date of this rule (for existing sources). 

During each quarter of source operation, the owner or operator 

must determine, record, and maintain a record of the ongoing 

accuracy of the system of measuring hourly clinker or feed

production. 

(3) You must record the daily clinker production rates and 

kiln feed rates.

(4) You must develop an emissions monitoring plan in 

accordance with paragraphs (o)(1) through (o)(4) of this 

section.

(c) You must monitor PM emissions of a kiln or clinker 

cooler subject to a PM emissions limit in §60.62(a)(1)(ii) or 

(b)(1)(ii) according to the applicable requirements below:

(1) Install and operate a PM continuous emissions 

monitoring system in accordance with Performance Specification 

11 of appendix B and Procedure 2 of appendix F to part 60 of 

this chapter. The performance test method and the correlation 

test method for Performance Specification 11 shall be Method 5 

or Method 5i of appendix A to this part. The owner or operator 

must also develop an emissions monitoring plan in accordance 

with paragraphs (o)(1) through (o)(4) of this section.

(2) Perform Relative Response Audits annually and Response 

Correlation Audits every 3 years.
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(3) Collect readings at least every 15 minutes in order to 

calculate the 30-day rolling average to determine PM emissions. 

Calculate the 30-day rolling average using equation 1 of this 

section:

 



n

i

PM utes

n

dayrolling average

1

1 5min

1

30

 (Eq. 1) 

where:

PM15 minutes = PM emissions from a 15 minute period

n = number of 15 minute periods with valid data over the 

preceding 30 days

(d) You must install, operate, calibrate, and maintain an 

instrument for continuously monitoring and recording the 

concentration by volume of NOx emissions into the atmosphere for 

any kiln subject to the NOx emissions limit in §60.62(a)(3). If 

the kiln has an alkali bypass, NOx emissions from the alkali 

bypass do not need to be monitored, and NOx emission monitoring 

of the kiln exhaust may be done upstream of any comingled alkali 

bypass gases. 

(e) You must install, operate, calibrate, and maintain an 

instrument for continuously monitoring and recording the 

concentration by volume of SO2 emissions into the atmosphere for 

any kiln subject to the SO2 emissions limit in §60.62(a)(4). If 

complying with the alternative 90 percent SO2 emissions reduction 
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emission limit, you must also continuously monitor and record 

the concentration by volume of SO2 present at the wet scrubber 

inlet.

(f) You must install, operate, and maintain according to 

Performance Specification 2 (40 CFR part 60, appendix B) and the 

requirements in paragraphs (f)(1) through (5) of this section

each CEMS required under paragraphs (c), (d) and (e) of this 

section. 

(1) The span value of each NOx monitor must 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) You must 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 must use Methods 7, 7A, 7C, 7D, or 7E of appendix A4 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.
Page 327 of 456

(4) You 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 must use Methods 6, 6A, or 6C 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 6 or 6A of Appendix A-4 to part 60.

(5) You 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.

(g) For each CEMS required under paragraphs (c) through 

(e) of this section:

(1) You must operate the monitoring system and collect data

at all required intervals at all times the affected source is 

operating except for periods of monitoring system malfunctions, 

repairs associated with monitoring system malfunctions, and 

required monitoring system quality assurance or quality control 

activities (including, as applicable, calibration checks and 

required zero and span adjustments).

(2) You may not use data recorded during the monitoring 

system malfunctions, repairs associated with monitoring system 

malfunctions, or required monitoring system quality assurance or 
Page 328 of 456

control activities in calculations used to report emissions or 

operating levels. A monitoring system malfunction is any 

sudden, infrequent, not reasonably preventable failure of the 

monitoring system to provide valid data. Monitoring system 

failures that are caused in part by poor maintenance or careless 

operation are not malfunctions. An owner or operator must use 

all the data collected during all other periods in assessing the 

operation of the control device and associated control system.

(3) You must meet the requirements of §60.13(h) when 

determining the 1-hour averages of emissions data needed to meet 

the minimum data requirements specified in paragraph (g)(1) of 

this section.

(h) You must install, operate, calibrate, and maintain instruments for continuously 

measuring and recording the pollutant per mass flow rate to the atmosphere for each kiln subject 

to the particulate matter emissions limit in §60.62(a)(3), the NOx emissions limit in §60.62(a)(3), 

or the SO2 emissions limit in §60.62(a)(4)(i) or (ii) according to the requirements in paragraphs 

(h)(1) through (10) 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, SO2 or PM CEMS, taking into 

account the manufacturer‘s recommendations. The flow rate 

sensor is that portion of the system that senses the volumetric 
Page 329 of 456

flow rate and generates an output proportional to that flow 

rate.

(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 

recording values over the entire range specified in paragraph 

(n)(1) 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.

(7) The flow rate sensor must have provisions to determine 

the daily zero and upscale calibration drift (CD) (see sections 

3.1 and 8.3 of Performance Specification 2 in appendix B to Part 

60 of this chapter for a discussion of CD).
Page 330 of 456

(i) Conduct the CD tests at two reference signal levels, 

zero (e.g., 0 – 20 percent of span) and upscale (e.g., 50 to 70 

percent of span).

(ii) The absolute value of the difference between the flow 

monitor response and the reference signal must be equal to or 

less than 3 percent of the flow monitor span.

(8) You must perform an initial relative accuracy test of 

the flow rate monitoring system according to Section 8.2 of 

Performance Specification 6 of appendix B to Part 60 of the 

chapter with the exceptions in paragraphs (n)(8)(i) and 

(n)(8)(ii).

(i) The relative accuracy test is to evaluate the flow rate 

monitoring system along rather than a continuous emission rate 

monitoring system.

(ii) The relative accuracy of the flow rate monitoring 

system shall be no greater than 10 percent of the mean value of 

the reference method data.

(9) You must verify the accuracy of the flow rate 

monitoring system at least once per year by repeating the 

relative accuracy test specified in paragraph (n)(8).

(10) 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, 

shutdown, and malfunction, except for periods of monitoring 
Page 331 of 456

system malfunctions, repairs associated with monitoring system 

malfunctions, and required monitoring system quality assurance 

or quality control activities (including, as applicable, 

calibration checks and required zero and span adjustments.

(i) Development and Submittal (Upon Request) of Monitoring 

Plans. If you demonstrate compliance with any applicable 

emission limit through performance stack testing or other 

emissions monitoring, you must develop a site-specific 

monitoring plan according to the requirements in paragraphs 

(i)(1) through (4) of this section. This requirement also 

applies to you if you petition the EPA Administrator for 

alternative monitoring parameters under paragraph (n) of this 

section and §63.8(f). If you use a BLDS, you must also meet the 

requirements specified in paragraph §63.1350(m)(10).

(1) For each continuous monitoring system (CMS) required in 

this section, you must develop, and submit to the permitting 

authority for approval upon request, a site-specific monitoring 

plan that addresses paragraphs (o)(1)(i) through (iii) of this 

section. You must submit this site-specific monitoring plan, if 

requested, at least 60 days before your initial performance 

evaluation of your CMS.

(i) Installation of the CEMS sampling probe or other 

interface at a measurement location relative to each affected 

process unit such that the measurement is representative of 
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control of the exhaust emissions (e.g., on or downstream of the 

last control device);

(ii) Performance and equipment specifications for the 

sample interface, the pollutant concentration or parametric 

signal analyzer, and the data collection and reduction systems; 

and

(iii) Performance evaluation procedures and acceptance 

criteria (e.g., calibrations).

(2) In your site-specific monitoring plan, you must also 

address paragraphs (o)(2)(i) through (iii) of this section.

(i) Ongoing operation and maintenance procedures in 

accordance with the general requirements of §63.8(c)(1), (c)(3), 

and (c)(4)(ii);

(ii) Ongoing data quality assurance procedures in 

accordance with the general requirements of §63.8(d); and

(iii) Ongoing recordkeeping and reporting procedures in 

accordance with the general requirements of §63.10(c), (e)(1), 

and (e)(2)(i).

(3) You must conduct a performance evaluation of each CMS 

in accordance with your site-specific monitoring plan.

(4) You must operate and maintain the CMS in continuous 

operation according to the site-specific monitoring plan.

5. Section 60.64 is amended to read as follows:

§60.64 Test methods and procedures
Page 333 of 456

a) In conducting the performance tests required in §60.8, 

you must use reference methods and procedures and the test 

methods in appendix A of this part or other methods and 

procedures as specified in this section, except as provided in 

§60.8(b).

(b) Compliance with the PM standards in §60.62 is 

determined using the procedures specified in §60.63.

(1) The PM emission rate is calculated using Equation 2

of this section: 

E (c Q )/(P K) 

s sd

(Eq. 2) 

Where: 

E = emission rate of particulate matter, lb/ton of kiln feed; 

Cs = concentration of particulate matter, gr/dscf; 

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

P = total kiln feed (dry basis) rate, ton/hr. For kilns 

constructed, modified or reconstructed on or after June 16, 

2008 p = total kiln clinker production rate; and

K = conversion factor, 7000 gr/lb.

(2) Suitable methods shall be used to determine the kiln 

feed rate (P), except fuels. 

(3) Method 9 and the procedures in §60.11 must be used to 

determine opacity.

(4) 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 this chapter.
Page 334 of 456

(5) If your kiln is not equipped with a PM CEMS meeting 

the requirements of PS-11, and the kiln (including any 

associated alkali bypass and clinker cooler) was constructed, 

modified or reconstructed on or after June 16, 2008, you 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 June 16, 2008 must 

conduct a performance test every 5 years if not equipped with a 

PM CEMS meeting the requirements of PS-11.

(c) You 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 days, divided by the 

total tons of clinker produced in that kiln during the same 30-

day period using Equation 3 of this section:

ton

(Cs Qsd) lb

 

K P

E Eq. 3

Where: 

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

clinker production; 

Cs = concentration of NOX or SO2, gr/dscf; 

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

P = total kiln clinker production rate, ton/hr; and

K = conversion factor, 7000 gr/lb.

(d) As of December 31, 2011 and within 60 days after the 

date of completing each performance evaluation or test, as 
Page 335 of 456

defined in §63.2, conducted to demonstrate compliance with this 

subpart, you must submit the relative accuracy test audit data 

and performance test data, except opacity data, to EPA by 

successfully submitting the data electronically to EPA‘s Central 

Data Exchange (CDX) by using the Electronic Reporting Tool(ERT) 

(see http://www.epa.gov/ttn/chief/ert/ert_tool.html/).

6. 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 to any non-opacity 

emissions standard.

(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.
Page 336 of 456

(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.

Appendix B – [AMENDED]

7. Appendix B to 40 CFR Part 60 is amended to read as 

follows:

a. Revise Performance Specification 12A.

b. Add Performance Specification 12B.

Appendix B to Part 60 – Performance Specifications

* * * * * 

Performance Specification 12A—Specifications and Test Procedures 

For Total Vapor Phase Mercury Continuous Emission Monitoring 

Systems in Stationary Sources

1.0 Scope and Application

1.1 Analyte. The analyte measured by these procedures and 

specifications is total vapor phase Hg in the flue gas, which 

represents the sum of elemental Hg (Hgo, CAS Number 7439-97-6) 

and oxidized forms of gaseous Hg (Hg+2), in concentration units 

of micrograms per cubic meter (μg/m3).

1.2 Applicability.

1.2.1 This specification is for evaluating the 

acceptability of total vapor phase Hg continuous emission 

monitoring systems (CEMS) installed at stationary sources at the 

time of or soon after installation and whenever specified in the 

regulations. The Hg CEMS must be capable of measuring the total 

concentration in μg/m3 of vapor phase Hg, regardless of 

speciation, and recording that concentration at standard 
Page 337 of 456

conditions on a wet or dry basis. These specifications do not 

address measurement of particle bound Hg.

1.2.2 This specification is not designed to evaluate an 

installed CEMS's performance over an extended period of time nor 

does it identify specific calibration techniques and auxiliary 

procedures to assess the CEMS's performance. The source owner 

or operator, however, is responsible to calibrate, maintain, and 

operate the CEMS properly. The Administrator may require, under 

section 114 of the Clean Air Act, the operator to conduct CEMS 

performance evaluations at other times besides the initial 

performance evaluation test. See §§60.13(c) and 63.8(e)(1).

1.2.3 Mercury monitoring approaches not entirely suited to 

these specifications may be approvable under the alternative 

monitoring or alternative test method provisions of §60.13(i) 

and §63.8(f) or §60.8(b)(3) and §63.7(f), respectively.

2.0 Summary of Performance Specification

Procedures for determining CEMS relative accuracy, 

linearity, and calibration drift are outlined. CEMS installation 

and measurement location specifications, data reduction 

procedures, and performance criteria are included. 

3.0 Definitions 

3.1 Continuous Emission Monitoring System (CEMS) means the 

total equipment required to measure a pollutant concentration. 

The system generally consists of the following three major 

subsystems:

3.2 Sample Interface means that portion of the CEMS used 

for one or more of the following: sample acquisition, sample 

transport, sample conditioning, and protection of the monitor 

from the effects of the stack effluent.

3.3 Hg Analyzer means that portion of the Hg CEMS that 

measures the total vapor phase Hg mass concentration and 

generates a proportional output.

3.4 Data Recorder means that portion of the CEMS that 

provides a permanent electronic record of the analyzer output. 

The data recorder may provide automatic data reduction and CEMS 

control capabilities.
Page 338 of 456

3.5 Span Value means the measurement range as specified in 

the applicable regulation or other requirement. If the span is 

not specified in the applicable regulation or other requirement, 

then it must be a value approximately equivalent to two times 

the emission standard. Unless otherwise specified, the span 

value may be rounded up to the nearest multiple of 10. 

3.6 Measurement Error Test means a test procedure in which 

the accuracy of the concentrations measured by a CEMS at three 

or more points over its measurement range is evaluated using 

reference gases. For Hg CEMS, elemental and oxidized Hg (Hg0 and 

mercuric chloride, HgCl2) gas standards of known concentration 

are used for this procedure.

3.7 Measurement Error (ME) means the absolute value of the 

difference between the concentration indicated by the CEMS and 

the known concentration of a reference gas, expressed as a 

percentage of the span value, when the entire CEMS, including 

the sampling interface, is challenged. 

3.8 Calibration Drift (CD) means the absolute value of the 

difference between the CEMS output response and either an 

upscale Hg reference gas or a zero-level Hg reference gas, 

expressed as a percentage of the span value, when the entire 

CEMS, including the sampling interface, is challenged after a 

stated period of operation during which no unscheduled 

maintenance or repair took place.

3.9 Relative Accuracy Test Procedure means a test 

procedure consisting of at least nine test runs, in which the 

accuracy of the concentrations measured by a CEMS is evaluated 

by comparison against concurrent measurements made with a 

reference method (RM). Relative accuracy tests repeated on a 

regular, on-going basis are referred to as relative accuracy 

test audits or RATAs.

3.10 Relative Accuracy (RA) means the absolute mean 

difference between the pollutant concentrations determined by 

the CEMS and the values determined by the RM plus the 2.5 

percent error confidence coefficient of a series of tests 

divided by the mean of the RM tests. Alternatively, for sources 

with an average RM concentration less than 5.0 micrograms per 

standard cubic meter (μg/scm), the RA may be expressed as the 

absolute value of the difference between the mean CEMS and RM 

values.

4.0 Interferences [Reserved]
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5.0 Safety 

The procedures required under this performance 

specification may involve hazardous materials, operations, and 

equipment. This performance specification may not address all 

of the safety problems associated with these procedures. It is 

the responsibility of the user to establish appropriate safety 

and health practices and determine the applicable regulatory 

limitations prior to performing these procedures. The CEMS 

user's manual and materials recommended by the RM should be 

consulted for specific precautions to be taken.

6.0 Equipment and Supplies

6.1 CEMS Equipment Specifications.

6.1.1 Data Recorder Scale. The Hg CEMS data recorder 

output range must include the full range of expected Hg 

concentration values in the gas stream to be sampled including 

zero and the span value. 

6.1.2 The Hg CEMS design should also provide for the 

determination of CD and ME at a zero value (zero to 20 percent

of the span value) and at upscale values (between 50 and 100 

percent of the span value). The Hg CEMS must be constructed to 

permit the introduction of known concentrations of Hg and HgCl2 

separately into the sampling system of the CEMS immediately 

preceding the sample extraction filtration system such that the 

entire CEMS can be challenged. 

6.2 Reference Gas Delivery System. The reference gas 

delivery system must be designed so that the flowrate exceeds 

the sampling system flow requirements of the CEMS and that the 

gas is delivered to the CEMS at atmospheric pressure.

6.3 Other equipment and supplies, as needed by the 

reference method used for the Relative Accuracy Test Procedure. 

See Section 8.6.2.

7.0 Reagents and Standards

7.1 Reference Gases. Reference gas standards are required 

for both elemental and oxidized Hg (Hg and mercuric chloride, 

HgCl2). The use of National Institute of Standards and 

Technology (NIST)-traceable standards and reagents is required. 

The following gas concentrations are required.
Page 340 of 456

7.1.1 Zero-level. 0 to 20 percent of the span value.

7.1.2 Mid-level. 50 to 60 percent of the span value.

7.1.3 High-level. 80 to 100 percent of the span value.

7.2 Reference gas standards may also be required for the 

reference methods. See Section 8.6.2.

8.0 Performance Specification Test Procedure

8.1 Installation and Measurement Location Specifications.

8.1.1 CEMS Installation. Install the CEMS at an 

accessible location downstream of all pollution control 

equipment. Place the probe outlet or other sampling interface 

at a point or location in the stack (or vent) representative of 

the stack gas concentration of Hg. Since the Hg CEMS sample 

system normally extracts gas from a single point in the stack, 

a location that has been shown to be free of stratification for 

Hg or, alternatively, SO2 is recommended. If the cause of 

failure to meet the RA test requirement is determined to be the 

measurement location and a satisfactory correction technique 

cannot be established, the Administrator may require the CEMS to 

be relocated. Measurement locations and points or paths that 

are most likely to provide data that will meet the RA 

requirements are described in Sections 8.1.2 and 8.1.3 below.

8.1.2 Measurement Location. The measurement location 

should be (1) at least two equivalent diameters downstream of 

the nearest control device, point of pollutant generation or 

other point at which a change of pollutant concentration may 

occur, and (2) at least half an equivalent diameter upstream 

from the effluent exhaust. The equivalent duct diameter is 

calculated according to Method 1 in appendix A-1 to this part.

8.1.3 Hg CEMS Sample Extraction Point. Use a sample 

extraction point either (1) no less than 1.0 meter from the 

stack or duct wall, or (2) within the centroidal velocity 

traverse area of the stack or duct cross section. This does not 

apply to cross-stack, in-situ measurement systems.

8.2 Measurement Error (ME) Test Procedure. Sequentially 

inject each of at least three elemental Hg reference gases 

(zero, mid-level, and high level, as defined in Section 7.1), 

three times each for a total of nine injections. Inject the 

gases in such a manner that the entire CEMS is challenged. Do 
Page 341 of 456

not inject the same gas concentration twice in succession. At 

each reference gas concentration, determine the average of the 

three CEMS responses and subtract the average response from the 

reference gas value. Calculate the measurement error (ME) using 

Equation 12-1 by expressing the absolute value of the difference 

between the average CEMS response (A) and the reference gas 

value (R) as a percentage of the span (see example data sheet in 

Figure 12A–1). For each elemental Hg reference gas, the 

absolute value of the difference between the CEMS response and 

the reference value must not exceed 5 percent of the span value. 

If this specification is not met, identify and correct the 

problem before proceeding. Repeat the measurement error test 

procedure using oxidized Hg reference gases. For each oxidized 

Hg reference gas, the absolute value of the difference between 

the CEMS response and the reference value shall not exceed 10 

percent of the span value. If this specification is not met, 

identify and correct the problem before proceeding.

x 100

Span

R A

ME





(Equation 12A-1)

8.3 Seven-Day Calibration Drift (CD) Test Procedure.

8.3.1 CD Test Period. While the affected facility is 

operating normally, or as specified in an applicable 

regulation, determine the magnitude of the CD once each day (at 

24-hour intervals, to the extent practicable) for 7 consecutive 

unit operating days according to the procedures in Sections 

8.3.2 and 8.3.3. The 7 consecutive unit operating days need not 

be 7 consecutive calendar days. Use either Hg° or HgCl2 

standards for this test.

8.3.2 The purpose of the CD measurement is to verify the 

ability of the CEMS to conform to the established CEMS response 

used for determining emission concentrations or emission rates. 

Therefore, if periodic automatic or manual adjustments are made 

to the CEMS zero and upscale response settings, conduct the CD 

test immediately before these adjustments, or conduct it in such 

a way that the CD can be determined.

8.3.3 Conduct the CD test using the zero gas specified and 

either the mid-level or high-level gas as specified in Section 

7.1. Sequentially introduce the reference gases to the CEMS at 

the sampling system of the CEMS immediately preceding the sample 

extraction filtration system. Record the CEMS response (A) for 

each reference gas and, using Equation 12A-2, subtract the 
Page 342 of 456

corresponding reference value (R) from the CEMS value, and 

express the absolute value of the difference as a percentage of 

the span value (see also example data sheet in Figure 12A–2). 

For each reference gas, the absolute value of the difference 

between the CEMS response and the reference value must not 

exceed 5 percent of the span value. If these specifications are 

not met, identify and correct the problem before proceeding.

x 100

Span

R A

CD





(Equation 12A-2)

8.4 Relative Accuracy (RA) Test Procedure.

8.4.1 RA Test Period. Conduct the RA test according to 

the procedure given in Sections 8.4.2 through 8.4.6 while the 

affected facility is operating normally, or as specified in an 

applicable subpart. The RA test may be conducted during the CD 

test period.

8.4.2 Reference Methods (RM). Unless otherwise specified 

in an applicable subpart of the regulations, use Method 29, 

Method 30A, or Method 30B in appendix A-8 to this part or 

American Society of Testing and Materials (ASTM) Method D6784–02 

(incorporated by reference, see §60.17) as the RM for Hg 

concentration. For Method 29 and ASTM Method D6784-02 only, the 

filterable portion of the sample need not be included when 

making comparisons to the CEMS results. When Method 29, Method 

30B, or ASTM D6784–02 is used, conduct the RM test runs with 

paired or duplicate sampling systems and use the average of the 

vapor phase Hg concentrations measured by the two trains. When 

Method 30A is used, paired sampling systems are not required. 

If the RM and CEMS measure on a different moisture basis, data 

derived with Method 4 in appendix A-3 to this part must also be 

obtained during the RA test.

8.4.3 Sampling Strategy for RM Tests. Conduct the RM 

tests in such a way that they will yield results representative 

of the emissions from the source and can be compared to the CEMS 

data. The RM and CEMS locations need not be immediately 

adjacent. Locate the RM measurement points in accordance with 

section 8.1.3 of Performance Specification 2 (PS 2) in this 

appendix. It is preferable to conduct moisture measurements (if 

needed) and Hg measurements simultaneously, although moisture 

measurements that are taken within an hour of the Hg 

measurements may be used to adjust the Hg concentrations to a 

consistent moisture basis. In order to correlate the CEMS and 
Page 343 of 456

RM data properly, note the beginning and end of each RM test 

period for each paired RM run (including the exact time of day) 

on the CEMS chart recordings or other permanent record of 

output.

8.4.4 Number and Length of RM Test Runs. Conduct a 

minimum of nine RM test runs. When Method 29, Method 30B, or 

ASTM D6784–02 is used, only test runs for which the paired RM 

trains meet the relative deviation criteria (RD) of this PS must

be used in the RA calculations. In addition, for Method 29 and 

ASTM D6784–02, use a minimum sample time of 2 hours and for 

Methods 30A and 30B use a minimum sample time of 30 minutes.

Note: More than nine sets of RM test runs may be performed. If this option is 

chosen, RM test run results may be excluded so long as the total number of RM 

test run results used to determine the CEMS RA is greater than or equal to 

nine. However, all data must be reported including the excluded test run 

data.

8.4.5 Correlation of RM and CEMS Data. Correlate the CEMS 

and the RM test data as to the time and duration by first 

determining from the CEMS final output (the one used for 

reporting) the integrated average pollutant concentration for 

each RM test period. Consider system response time, if 

important, and confirm that the results are on a consistent 

moisture basis with the RM test. Then, compare each integrated 

CEMS value against the corresponding RM value. When Method 29, 

Method 30B, or ASTM D6784–02 is used, compare each CEMS value 

against the corresponding average of the paired RM values.

8.4.6 Paired RM Outliers.

8.4.6.1 When Method 29, Method 30B, or ASTM D6784–02 is 

used, outliers are identified through the determination of 

relative deviation (RD) of the paired RM tests. Data that do 

not meet the RD criteria must be flagged as a data quality 

problem and may not be used in the calculation of RA. The 

primary reason for performing paired RM sampling is to ensure 

the quality of the RM data. The percent RD of paired data is 

the parameter used to quantify data quality. Determine RD for 

paired data points as follows:

x 100

C C

C C

RD

a b

a b







(Equation 12A-3)

Where: Ca and Cb are the Hg concentration values determined 

from the paired samples.
Page 344 of 456

8.4.6.2 The minimum performance criteria for RM Hg data is 

that RD for any data pair must be ≤ 10 percent as long as the 

mean Hg concentration is greater than 1.0 μg/m3. If the mean Hg 

concentration is less than or equal to 1.0 μg/m3, the RD must be 

≤ 20 percent or < 0.2 μg/m3 absolute difference. Pairs of RM 

data exceeding these RD criteria should be eliminated from the 

data set used to develop a Hg CEMS correlation or to assess CEMS 

RA.

8.4.7 Calculate the mean difference between the RM and 

CEMS values in the units of micrograms per cubic meter (μg/m3), 

the standard deviation, the confidence coefficient, and the RA 

according to the procedures in Section 12.0.

8.5 Reporting. At a minimum (check with the appropriate 

EPA Regional Office, State or local Agency for additional 

requirements, if any), summarize in tabular form the results of 

the CD tests, the linearity tests, and the RA test or 

alternative RA procedure, as appropriate. Include all data

sheets, calculations, charts (records of CEMS responses), 

reference gas concentration certifications, and any other 

information necessary to confirm that the CEMS meets the 

performance criteria.

9.0 Quality Control [Reserved]

10.0 Calibration and Standardization [Reserved]

11.0 Analytical Procedure 

For Method 30A, sample collection and analysis are 

concurrent. For the other RM, post-run sample analyses are 

performed. Refer to the RM employed for specific analytical 

procedures.

12.0 Calculations and Data Analysis 

Calculate and summarize the RA test results on a data sheet 

similar to Figure 12A–3.

12.1 Consistent Basis. All data from the RM and CEMS must 

be compared in units of micrograms per standard cubic meter 

(μg/scm), on a consistent and identified moisture basis. The 

values must be standardized to 20°C, 760 mm Hg.

12.1.1 Moisture Correction (as applicable). If the RM and 

CEMS measure Hg on a different moisture basis, they will need to 
Page 345 of 456

be corrected to a consistent basis. Use Equation 12A–4a to 

correct data from a wet basis to a dry basis.

(1 )

( )

( )

ws

wet

dry B

Concentration

Concentration





(Equation 12A-4a) 

Use Equation 12A-4b to correct data from a dry basis to a wet 

basis.

  wet dry Bws Concentration( ) Concentration( )  1 (Equation 12A-4b)

Where: Bws is the moisture content of the flue gas from 

Method 4, expressed as a decimal fraction ( e.g. , for 8.0 

percent H2O, Bws= 0.08).

12.2 Arithmetic Mean. Calculate 

d

,the arithmetic mean of 

the differences (di) of a data set as follows:





n

i

di

n

d

1

1

(Equation 12A-5)

Where: n = Number of data points.

12.3 Standard Deviation. Calculate the standard 

deviation, Sd, as follows:

2

1

1

2

2 1

1



































































n

n

d

d

S

n

i

n

i

i

i

d (Equation 12A-6)

Where:

 



n

i

di

1

Algebraic sum of the individual differences 

i d . 

12.3 Confidence Coefficient (CC). Calculate the 2.5 

percent error confidence coefficient (one-tailed), CC, 

as follows:
Page 346 of 456

n

S

CC t

d

 0.975

(Equation 12A-7)

12.4 Relative Accuracy. Calculate the RA of a set of data 

as follows:

 

x100

RM

d CC

RA





(Equation 12A-8)

Where:

|

d

| = Absolute value of the mean of the differences (from 

Equation 12A-5)

|CC| = Absolute value of the confidence coefficient (from 

Equation 12A-7)

RM

= Average reference method value

13.0 Method Performance 

13.1 Measurement Error (ME). For Hg0, the ME must not 

exceed 5 percent of the span value at the zero-, mid-, and highlevel reference gas concentrations. For HgCl2, the ME must not 

exceed 10 percent of the span value at the zero-, mid-, and 

high-level reference gas concentrations.

13.2 Calibration Drift (CD). The CD must not exceed 5 

percent of the span value on any of the 7 days of the CD test.

13.3 Relative Accuracy (RA). The RA of the CEMS must be 

no greater than 20 percent of the mean value of the RM test data 

in terms of units of μg/scm. Alternatively, if the mean RM is 

less than 5.0 μg/scm, the results are acceptable if the absolute 

value of the difference between the mean RM and CEMS values does 

not exceed 1.0 μg/scm.

14.0 Pollution Prevention [Reserved]

15.0 Waste Management [Reserved]

16.0 Alternative Procedures [Reserved]

17.0 Bibliography 
Page 347 of 456

17.1 40 CFR part 60, appendix B, ―Performance 

Specification 2—Specifications and Test Procedures for SO2 and 

NOx Continuous Emission Monitoring Systems in Stationary 

Sources.‖

17.2 40 CFR part 60, appendix A, ―Method 29—Determination 

of Metals Emissions from Stationary Sources.‖

17.3 40 CFR part 60, appendix A, ―Method 30A –

Determination of Total Vapor Phase Mercury Emissions From 

Stationary Sources (Instrumental Analyzer Procedure).

17.4 40 CFR part 60, appendix A, ―Method 30B –

Determination of Total Vapor Phase Mercury Emissions From CoalFired Combustion Sources Using Carbon Sorbent Traps.‖

17.5 ASTM Method D6784–02, ―Standard Test Method for 

Elemental, Oxidized, Particle-Bound and Total Mercury in Flue 

Gas Generated from Coal-Fired Stationary Sources (Ontario Hydro 

Method).‖

18.0 Tables and Figures 

Table 12A–1. T-Values

n

a t0.975 na t0.975 na t0.975

2 12.706 7 2.447 12 2.201

3 4.303 8 2.365 13 2.179

4 3.182 9 2.306 14 2.160

5 2.776 10 2.262 15 2.145

6 2.571 11 2.228 16 2.131

a

The values in this table are already corrected for n–1 degrees of freedom. Use n equal to the 

number of individual values.
Page 348 of 456

Figure 12A–1. ME Determination

 Date Time

Reference

Gas Value 

(μg/m3)

CEMS

Measured

Value 

(μg/m3)

Absolute

Difference

(μg/m3)

ME

(% of span 

value)

Zero 

level 

 

 

 

Average

 

 

Mid 

level 

 

 

 Average 

High 

level 

 

 

 

 

 Average 
Page 349 of 456

Figure 12A-2. 7-Day Calibration Drift Determination

 Date Time

Reference

Gas Value 

(μg/m3)

CEMS

measured

value 

(μg/m3)

Absolute

Differen

ce

(μg/m3)

CD

(% of Span 

Value)

Zero level 

 

 

 

 

 

 

 Upscale

(Mid or 

High) 

 

 

 

 

 
Page 350 of 456

Figure 12A-3. Relative Accuracy Test Data 

Run 

No. Date

Begin 

Time

End 

Time

RM 

Value 

(μg/m3)

CEMS 

Value

(μg/m3)

Difference

(μg/m3)

Run Used 

?

(Yes/No)

RD1

1

2

3

4

5

6

7

8

9

10

11

12

 

Average Values

 

Arithmetic Mean Difference:

Standard Deviation: 

Confidence Coefficient:

T-Value:

 

% Relative Accuracy:

 

| (RM)avg - (CEMS)avg | :

 

1 Calculate the RD only if paired samples are taken using RM 30B, 

RM 29, or ASTM 6784-08. Express RD as a percentage or, for very low RM 

concentrations (≤ 1.0 μg/m3), as the absolute difference between Ca and 

Cb. 
Page 351 of 456

Performance Specification 12B – Specifications and Test 

Procedures For Monitoring Total Vapor Phase Mercury Emissions 

from Stationary Sources Using a Sorbent Trap Monitoring System

1.0 Scope and Application

The purpose of Performance Specification 12B (PS 12B) is to

establish performance benchmarks for, and to evaluate the 

acceptability of sorbent trap monitoring systems used to monitor 

total vapor-phase mercury (Hg) emissions in stationary source 

flue gas streams. These monitoring systems involve continuous 

repetitive in-stack sampling using paired sorbent media traps 

with periodic analysis of the time-integrated samples. Persons 

using PS 12B should have a thorough working knowledge of Methods 

1, 2, 3, 4, 5 and 30B in appendices A-1 through A-3 and A-8 to 

this part.

1.1 Analyte. The analyte measured by these procedures and 

specifications is total vapor phase Hg in the flue gas, which 

represents the sum of elemental Hg (Hgo, CAS Number 7439-97-6) 

and gaseous forms of oxidized Hg (i.e., Hg+2) in mass 

concentration units of micrograms per dry standard cubic meter 

(μg/dscm).

1.2 Applicability.

1.2.1 These procedures are only intended for use under 

relatively low particulate conditions (e.g., monitoring after 

all pollution control devices). This specification is for 

evaluating the acceptability of total vapor phase Hg sorbent 

trap monitoring systems installed at stationary sources at the 

time of, or soon after, installation and whenever specified in 

the regulations. The Hg monitoring system must be capable of 

measuring the total concentration of vapor phase Hg (regardless 

of speciation), in units of μg/dscm. 

1.2.2 This specification contains routine procedures and 

specifications designed to evaluate an installed sorbent trap 

monitoring system‘s performance over time; Procedure 5 of 

appendix F to this part contains additional procedures and 

specifications which may be required for long term operation. 

In addition, the source owner or operator is responsible to 

calibrate, maintain, and operate the monitoring system properly. 

The Administrator may require the owner or operator, under 

section 114 of the Clean Air Act, to conduct performance 

evaluations at other times besides the initial test to evaluate 

the CEMS performance. See §60.13(c) and 63.8(e)(1).
Page 352 of 456

2.0 Principle

Known volumes of flue gas are continuously extracted from a 

stack or duct through paired, in-stack, pre-spiked sorbent media 

traps at appropriate nominal flow rates. The sorbent traps in 

the sampling system are periodically exchanged with new ones, 

prepared for analysis as needed, and analyzed by any technique 

that can meet the performance criteria. For quality-assurance 

purposes, a section of each sorbent trap is spiked with Hg0 prior 

to sampling. Following sampling, this section is analyzed 

separately and a specified minimum percentage of the spike must 

be recovered. Paired train sampling is required to determine 

method precision.

3.0 Definitions

3.1 Sorbent Trap Monitoring System means the total 

equipment required for the collection of gaseous Hg samples 

using paired three-partition sorbent traps. 

3.2 Relative Accuracy Test Procedure means a test 

procedure consisting of at least nine runs, in which the 

accuracy of the total vapor phase Hg concentrations measured by 

the sorbent trap monitoring system is evaluated by comparison 

against concurrent measurements made with a reference method

(RM). Relative accuracy tests repeated on a regular, on-going 

basis are referred to as relative accuracy test audits or RATAs. 

3.3 Relative Accuracy (RA) means the absolute mean 

difference between the pollutant (Hg) concentrations determined 

by the sorbent trap monitoring system and the values determined 

by the reference method (RM) plus the 2.5 percent error 

confidence coefficient of a series of tests divided by the mean 

of the RM tests. Alternatively, for low concentration sources, 

the RA may be expressed as the absolute value of the difference 

between the mean sorbent trap monitoring system and RM values. 

3.4 Relative Deviation (RD) means the absolute difference 

of the Hg concentration values obtained with a pair of sorbent 

traps divided by the sum of those concentrations, expressed as a 

percentage. RD is used to assess the precision of the sorbent 

trap monitoring system.

3.5 Spike Recovery means the mass of Hg recovered from the 

spiked trap section, expressed as a percentage of the amount 

spiked. Spike recovery is used to assess sample matrix 

interference.
Page 353 of 456

4.0 Interferences [Reserved]

5.0 Safety 

The procedures required under this performance 

specification may involve hazardous materials, operations, and 

equipment. This performance specification may not address all 

of the safety problems associated with these procedures. It is 

the responsibility of the user to establish appropriate safety 

and health practices and determine the applicable regulatory 

limitations prior to performing these procedures. 

6.0 Equipment and Supplies 

6.1 Sorbent Trap Monitoring System Equipment 

Specifications. 

6.1.1 Monitoring System. The equipment described in 

Method 30B in appendix A-8 to this part must be used to 

continuously sample for Hg emissions, with the substitution of 

three-section traps in place of two-section traps, as described 

below. A typical sorbent trap monitoring system is shown in 

Figure 12B-1. 

6.1.2 Three-Section Sorbent Traps. The sorbent media used 

to collect Hg must be configured in traps with three distinct 

and identical segments or sections, connected in series, to be 

separately analyzed. Section 1 is designated for primary 

capture of gaseous Hg. Section 2 is designated as a backup 

section for determination of vapor-phase Hg breakthrough. 

Section 3 is designated for QA/QC purposes. Section 3 must be 

spiked with a known amount of gaseous Hg0 prior to sampling and 

later analyzed to determine the spike (and hence sample) 

recovery efficiency. 
Page 354 of 456

 Figure 12B-1. Typical Sorbent Trap Monitoring System (only 

one trap and associated sampling system is illustrated).

6.1.3 Gaseous Hgo Sorbent Trap Spiking System. A known 

mass of gaseous Hg0 must be spiked onto section 3 of each sorbent 

trap prior to sampling. Any approach capable of quantitatively 

delivering known masses of Hg0 onto sorbent traps is acceptable. 

Several technologies or devices are available to meet this 

objective. Their practicality is a function of Hg mass spike 

levels. For low levels, NIST-certified or NIST-traceable gas 

generators or tanks may be suitable, but will likely require 

long preparation times. A more practical, alternative system, 

capable of delivering almost any mass required, employs

NIST-certified or NIST-traceable Hg salt solutions (e.g., 

Hg(NO3)2). With this system, an aliquot of known volume and 

concentration is added to a reaction vessel containing a 

reducing agent (e.g., stannous chloride); the Hg salt solution 
Page 355 of 456

is reduced to Hg0 and purged onto section 3 of the sorbent trap 

by using an impinger sparging system.

6.1.4 Sample Analysis Equipment. Any analytical system 

capable of quantitatively recovering and quantifying total 

gaseous Hg from sorbent media is acceptable provided that the 

analysis can meet the performance criteria in Table 12B-1 in 

Section 9 of this performance specification. Candidate recovery 

techniques include leaching, digestion, and thermal desorption. 

Candidate analytical techniques include ultraviolet atomic 

fluorescence (UV AF); ultraviolet atomic absorption (UV AA), 

with and without gold trapping; and in-situ X-ray fluorescence 

(XRF).

7.0 Reagents and Standards

Only NIST-certified or NIST-traceable calibration gas 

standards and reagents must be used for the tests and procedures 

required under this performance specification. The sorbent 

media may be any collection material (e.g., carbon, chemicallytreated filter, etc.) capable of quantitatively capturing and 

recovering for subsequent analysis, all gaseous forms of Hg in 

the emissions from the intended application. Selection of the 

sorbent media must be based on the material's ability to achieve 

the performance criteria contained in this method as well as the 

sorbent's vapor phase Hg capture efficiency for the emissions 

matrix and the expected sampling duration at the test site. 

8.0 Performance Specification Test Procedure

8.1 Installation and Measurement Location Specifications.

8.1.1 Selection of Monitoring Site. Sampling site 

information should be obtained in accordance with Method 1 in 

appendix A-1 to this part. Place the probe inlet at a point or 

location in the stack (or vent) downstream of all pollution 

control equipment and representative of the stack gas 

concentration of Hg. A location that has been shown to be free 

of stratification for Hg or, alternatively, SO2 is recommended. 

An estimation of the expected stack Hg concentration is required 

to establish a target sample flow rate, total gas sample volume, 

and the mass of Hg0 to be spiked onto section 3 of each sorbent 

trap.

8.1.2 Pre-sampling Spiking of Sorbent Traps. Based on the 

estimated Hg concentration in the stack, the target sample rate 

and the target sampling duration, calculate the expected mass 

loading for section 1 of each sorbent trap (see Section 12.1 of 
Page 356 of 456

this performance specification). The pre-sampling spike to be 

added to section 3 of each sorbent trap must be within ± 50 

percent of the expected section 1 mass loading. Spike section 3 

of each sorbent trap at this level, as described in Section 

6.1.3 of this performance specification. For each sorbent trap, 

keep a record of the mass of Hgo added to section 3. This record 

must include, at a minimum, the identification number of the 

trap, the date and time of the spike, the name of the analyst 

performing the procedure, the method of spiking, the mass of Hgo

added to section 3 of the trap (μg), and the supporting 

calculations.

8.1.3 Pre-monitoring Leak Check. Perform a leak check with 

the sorbent traps in place in the sampling system. Draw a 

vacuum in each sample train. Adjust the vacuum in each sample 

train to ~15" Hg. Use the gas flow meter to determine leak 

rate. The leakage rate must not exceed 4 percent of the target 

sampling rate. Once the leak check passes this criterion, 

carefully release the vacuum in the sample train, then seal the 

sorbent trap inlet until the probe is ready for insertion into 

the stack or duct.

8.1.4 Determination of Flue Gas Characteristics. 

Determine or measure the flue gas measurement environment 

characteristics (gas temperature, static pressure, gas velocity, 

stack moisture, etc.) in order to determine ancillary 

requirements such as probe heating requirements (if any), 

sampling rate, proportional sampling conditions, moisture 

management, etc.

8.2 Monitoring. 

8.2.1 System Preparation and Initial Data Recording. 

Remove the plug from the end of each sorbent trap and store each 

plug in a clean sorbent trap storage container. Remove the 

stack or duct port cap and insert the probe(s) with the inlet(s) 

aligned perpendicular to the stack gas flow. Secure the probe(s) 

and ensure that no leakage occurs between the duct and 

environment. Record initial data including the sorbent trap ID,

start time, starting gas flow meter readings, initial 

temperatures, set points, and any other appropriate information.

8.2.2 Flow Rate Control. Set the initial sample flow rate 

at the target value from section 8.1.1 of this performance 

specification. Then, for every operating hour during the 

sampling period, record the date and time, the sample flow rate, 

the gas flow meter reading, the stack temperature (if needed), 
Page 357 of 456

the flow meter temperatures (if needed), temperatures of heated 

equipment such as the vacuum lines and the probes (if heated), 

and the sampling system vacuum readings. Also, record the stack 

gas flow rate and the ratio of the stack gas flow rate to the 

sample flow rate. Adjust the sampling flow rate to maintain 

proportional sampling, i.e., keep the ratio of the stack gas 

flow rate to sample flow rate within ± 25 percent of the 

reference ratio from the first hour of the data collection 

period (see section 12.2 of this performance specification). 

The sample flow rate through a sorbent trap monitoring system 

during any hour (or portion of an hour) that the unit is not 

operating must be zero. 

8.2.3 Stack Gas Moisture Determination. If data from the 

sorbent trap monitoring system will be used to calculate Hg mass 

emissions, determine the stack gas moisture content using a 

continuous moisture monitoring system or other means acceptable 

to the Administrator, such as the ones described in §75.11(b) of 

this chapter. Alternatively, for combustion of coal, wood, or 

natural gas in boilers only, a default moisture percentage from 

§75.11(b) of this chapter may be used. 

8.2.4 Essential Operating Data. Obtain and record any 

essential operating data for the facility during the test 

period, e.g., the barometric pressure for correcting the sample 

volume measured by a dry gas meter to standard conditions. At 

the end of the data collection period, record the final gas flow 

meter reading and the final values of all other essential 

parameters.

8.2.5 Post-monitoring Leak Check. When the monitoring 

period is completed, turn off the sample pump, remove the 

probe/sorbent trap from the port and carefully re-plug the end 

of each sorbent trap. Perform a leak check with the sorbent 

traps in place, at the maximum vacuum reached during the 

monitoring period. Use the same general approach described in 

section 8.1.3 of this performance specification. Record the 

leakage rate and vacuum. The leakage rate must not exceed 4 

percent of the average sampling rate for the monitoring period. 

Following the leak check, carefully release the vacuum in the 

sample train.

8.2.6 Sample Recovery. Recover each sampled sorbent trap 

by removing it from the probe and seal both ends. Wipe any 

deposited material from the outside of the sorbent trap. Place 

the sorbent trap into an appropriate sample storage container 

and store/preserve it in an appropriate manner.
Page 358 of 456

8.2.7 Sample Preservation, Storage, and Transport. While 

the performance criteria of this approach provide for 

verification of appropriate sample handling, it is still 

important that the user consider, determine, and plan for 

suitable sample preservation, storage, transport, and holding 

times for these measurements. Therefore, procedures in

recognized voluntary consensus standards such as those in ASTM 

D6911-03 "Standard Guide for Packaging and Shipping 

Environmental Samples for Laboratory Analysis" should be 

followed for all samples.

8.2.8 Sample Custody. Proper procedures and documentation 

for sample chain of custody are critical to ensuring data 

integrity. Chain of custody procedures in recognized voluntary 

consensus standards such as those in ASTM D4840-99 "Standard 

Guide for Sample Chain-of-Custody Procedures" should be followed 

for all samples (including field samples and blanks).

8.3 Relative Accuracy (RA) Test Procedure

8.3.1 For the initial certification of a sorbent trap 

monitoring system, a RA Test is required. Follow the basic RA

test procedures and calculation methodology described in 

Sections 8.4.1 through 8.4.7 and 12.4 of PS 12A in this 

appendix, replacing the term ―CEMS‖ with ―sorbent trap 

monitoring system‖.

8.3.2 Special Considerations. The type of sorbent 

material used in the traps must be the same as that used for 

daily operation of the monitoring system; however, the size of 

the traps used for the RA test may be smaller than the traps 

used for daily operation of the system. Spike the third section 

of each sorbent trap with elemental Hg, as described in section 

8.1.2 of this performance specification. Install a new pair of 

sorbent traps prior to each test run. For each run, the sorbent 

trap data must be validated according to the quality assurance 

criteria in Table 12B-1 in Section 9.0, below. 

8.3.3 Acceptance Criteria. The RA of the sorbent trap 

monitoring system must be no greater than 20 percent of the mean 

value of the RM test data in terms of units of μg/scm. 

Alternatively, if the RM concentration is less than or equal to 

5.0 μg/scm, then the RA results are acceptable if the absolute 

difference between the means of the RM and sorbent trap 

monitoring system values does not exceed 1.0 μg/scm. 
Page 359 of 456

9.0 Quality Assurance and Quality Control (QA/QC)

Table 12B-1 summarizes the QA/QC performance criteria that 

are used to validate the Hg emissions data from a sorbent trap 

monitoring system. Failure to achieve these performance 

criteria will result in invalidation of Hg emissions data, 

except where otherwise noted.

 

TABLE 12B-1. QA/QC CRITERIA FOR SORBENT TRAP MONITORING SYSTEM OPERATION AND 

CERTIFICATION

QA/QC Test or Specification Acceptance Criteria Frequency Consequences if Not Met

Pre-monitoring leak check ≤4% of target sampling rate Prior to monitoring

Monitoring must not 

commence until the leak 

check is passed

Post-monitoring leak check ≤4% of average sampling rate After monitoring Invalidate the data from 

the paired traps or, if 

certain conditions are met, 

report adjusted data from 

a single trap (see Section 

12.7.1.3)

Ratio of stack gas flow rate to 

sample flow rate

Hourly ratio may not deviate 

from the reference ratio by 

more than ± 25%. 

Every hour throughout

monitoring period

Invalidate the data from 

the paired traps or, if 

certain conditions are met, 

report adjusted data from 

a single trap (see Section 

12.7.1.3)

Sorbent trap section 2 

breakthrough ≤5% of Section 1 Hg mass Every sample Invalidate the data from 

the paired traps or, if 

certain conditions are met, 

report adjusted data from 

a single trap (see Section 

12.7.1.3)

Paired sorbent trap 

agreement 

≤10% Relative Deviation (RD) 

if the average concentration 

is > 1.0 μg/m3

< 20% RD if the average 

concentration is < 1.0 μg/m3

Results also acceptable if 

absolute difference between 

concentrations from paired 

traps is ≤ 0.03 μg/m3

Every sample

Either invalidate the data 

from the paired traps or 

report the results from the 

trap with the higher Hg 

concentration

Spike Recovery Study 

Average recovery between 

85% and 115% for each of 

the 3 spike concentration 

levels

Prior to analyzing field 

samples and prior to 

use of new sorbent 

media

Field samples must not be 

analyzed until the percent 

recovery criteria has been 

met

Multipoint analyzer calibration Each analyzer reading within On the day of Recalibrate until 
Page 360 of 456

± 10% of true value and 

r

2

0.99

analysis, before 

analyzing any samples

successful

Analysis of independent 

calibration standard Within ± 10% of true value 

Following daily 

calibration, prior to 

analyzing field 

samples

Recalibrate and repeat 

independent standard 

analysis until successful

Spike recovery from section 3 

of both sorbent traps

75-125% of spike amount Every sample

Invalidate the data from 

the paired traps or, if 

certain conditions are met, 

report adjusted data from 

a single trap (see Section 

12.7.1.3)

Relative Accuracy

RA ≤ 20.0% of RM mean 

value; or if RM mean value 

< 5.0 μg/scm, absolute 

difference between RM and 

sorbent trap monitoring 

system mean values ≤ 1.0 

μg/scm

RA specification must 

be met for initial 

certification 

Data from the system are 

invalid until a RA test is 

passed

Gas flow meter calibration 

An initial calibration factor (Y) 

has been determined at 3 

settings; for mass flow 

meters, initial calibration with 

stack gas has been 

performed. For subsequent 

calibrations, Y within + 5% of 

average value from the most 

recent 3-point calibration

At 3 settings prior to 

initial use and at least 

quarterly at one 

setting thereafter

Recalibrate meter at 3 

settings to determine a 

new value of Y

Temperature sensor 

calibration 

Absolute temperature 

measured by sensor within ± 

1.5% of a reference sensor

Prior to initial use and 

at least quarterly 

thereafter

Recalibrate; sensor may 

not be used until 

specification is met

Barometer calibration

Absolute pressure measured 

by instrument within ± 10 mm 

Hg of reading with a NISTtraceable barometer

Prior to initial use and 

at least quarterly 

thereafter

Recalibrate; instrument 

may not be used until 

specification is met

10.0 Calibration and Standardization

10.1 Gaseous and Liquid Standards. Only NIST certified or 

NIST-traceable calibration standards (i.e., calibration gases, 

solutions, etc.) must be used for the spiking and analytical 

procedures in this performance specification.

10.2 Gas Flow Meter Calibration. The manufacturer or 

supplier of the gas flow meter should perform all necessary setup, testing, programming, etc., and should provide the end user 

with any necessary instructions, to ensure that the meter will 

give an accurate readout of dry gas volume in standard cubic 

meters for the particular field application.
Page 361 of 456

10.2.1 Initial Calibration. Prior to its initial use, a 

calibration of the flow meter must be performed. The initial 

calibration may be done by the manufacturer, by the equipment 

supplier, or by the end user. If the flow meter is volumetric 

in nature (e.g., a dry gas meter), the manufacturer, equipment 

supplier, or end user may perform a direct volumetric 

calibration using any gas. For a mass flow meter, the 

manufacturer, equipment supplier, or end user may calibrate the 

meter using a bottled gas mixture containing 12 ± 0.5% CO2, 7 ± 

0.5% O2, and balance N2, or these same gases in proportions more 

representative of the expected stack gas composition. Mass flow 

meters may also be initially calibrated on-site, using actual 

stack gas.

10.2.1.1 Initial Calibration Procedures. Determine an 

average calibration factor (Y) for the gas flow meter, by 

calibrating it at three sample flow rate settings covering the 

range of sample flow rates at which the sorbent trap monitoring 

system typically operates. Either the procedures in section 

10.3.1 of Method 5 in appendix A-3 to this part or the 

procedures in section 16 of Method 5 in appendix A-3 to this 

part may be followed. If a dry gas meter is being calibrated, 

use at least five revolutions of the meter at each flow rate.

10.2.1.2 Alternative Initial Calibration Procedures. 

Alternatively, the initial calibration of the gas flow meter may 

be performed using a reference gas flow meter (RGFM). The RGFM

may be either: (1) A wet test meter calibrated according to 

section 10.3.1 of Method 5 in appendix A–3 to this part; (2) A 

gas flow metering device calibrated at multiple flow rates using 

the procedures in section 16 of Method 5 in appendix A–3 to this 

part; or (3) A NIST–traceable calibration device capable of 

measuring volumetric flow to an accuracy of 1 percent. To 

calibrate the gas flow meter using the RGFM, proceed as follows: 

While the sorbent trap monitoring system is sampling the actual 

stack gas or a compressed gas mixture that simulates the stack 

gas composition (as applicable), connect the RGFM to the 

discharge of the system. Care should be taken to minimize the 

dead volume between the sample flow meter being tested and the 

RGFM. Concurrently measure dry gas volume with the RGFM and the 

flow meter being calibrated for a minimum of 10 minutes at each 

of three flow rates covering the typical range of operation of 

the sorbent trap monitoring system. For each 10-minute (or 

longer) data collection period, record the total sample volume, 

in units of dry standard cubic meters (dscm), measured by the 

RGFM and the gas flow meter being tested.
Page 362 of 456

10.2.1.3 Initial Calibration Factor. Calculate an 

individual calibration factor Yi at each tested flow rate from 

section 10.2.1.1 or 10.2.1.2 of this performance specification 

(as applicable), by taking the ratio of the reference sample 

volume to the sample volume recorded by the gas flow meter. 

Average the three Yi values, to determine Y, the calibration 

factor for the flow meter. Each of the three individual values 

of Yi must be within ±0.02 of Y. Except as otherwise provided 

in sections 10.2.1.4 and 10.2.1.5 of this performance 

specification, use the average Y value from the three level 

calibration to adjust all subsequent gas volume measurements 

made with the gas flow meter.

10.2.2 Initial On-Site Calibration Check. For a mass flow 

meter that was initially calibrated using a compressed gas 

mixture, an on-site calibration check must be performed before 

using the flow meter to provide data. While sampling stack gas, 

check the calibration of the flow meter at one intermediate flow 

rate typical of normal operation of the monitoring system. 

Follow the basic procedures in section 10.2.1.1 or 10.2.1.2 of 

this performance specification. If the onsite calibration check 

shows that the value of Yi, the calibration factor at the tested 

flow rate, differs by more than 5 percent from the value of Y 

obtained in the initial calibration of the meter, repeat the 

full 3-level calibration of the meter using stack gas to 

determine a new value of Y, and apply the new Y value to all 

subsequent gas volume measurements made with the gas flow meter.

10.2.3 Ongoing Quality Control. Recalibrate the gas flow 

meter quarterly at one intermediate flow rate setting 

representative of normal operation of the monitoring system. 

Follow the basic procedures in section 10.2.1.1 or 10.2.1.2 of 

this performance specification. If a quarterly recalibration 

shows that the value of Yi, the calibration factor at the tested 

flow rate, differs from the current value of Y by more than 5 

percent, repeat the full 3-level calibration of the meter to 

determine a new value of Y, and apply the new Y value to all 

subsequent gas volume measurements made with the gas flow meter.

10.3 Calibration of Thermocouples and Other Temperature 

Sensors. Use the procedures and criteria in section 10.3 of 

Method 2 in appendix A–1 to this part to calibrate in-stack 

temperature sensors and thermocouples. Calibrations must be 

performed prior to initial use and at least quarterly 

thereafter. At each calibration point, the absolute temperature 

measured by the temperature sensor must agree to within ±1.5 
Page 363 of 456

percent of the temperature measured with the reference sensor, 

otherwise the sensor may not continue to be used.

10.4 Barometer Calibration. Calibrate the barometer 

against another barometer that has a NIST-traceable calibration. 

This calibration must be performed prior to initial use and at 

least quarterly thereafter. At each calibration point, the 

absolute pressure measured by the barometer must agree to within 

±10 mm Hg of the pressure measured by the NIST-traceable 

barometer, otherwise the barometer may not continue to be used.

10.5 Calibration of Other Sensors and Gauges. Calibrate 

all other sensors and gauges according to the procedures 

specified by the instrument manufacturer(s).

10.6 Analytical System Calibration. See section 11.1 of 

this performance specification.

11.0 Analytical Procedures

The analysis of the Hg samples may be conducted using any 

instrument or technology capable of quantifying total Hg from 

the sorbent media and meeting the performance criteria in 

section 9 of this performance specification.

11.1 Analyzer System Calibration. Perform a multipoint 

calibration of the analyzer at three or more upscale points over 

the desired quantitative range (multiple calibration ranges must

be calibrated, if necessary). The field samples analyzed must 

fall within a calibrated, quantitative range and meet the 

necessary performance criteria. For samples that are suitable 

for aliquotting, a series of dilutions may be needed to ensure 

that the samples fall within a calibrated range. However, for 

sorbent media samples that are consumed during analysis (e.g.,

thermal desorption techniques), extra care must be taken to 

ensure that the analytical system is appropriately calibrated 

prior to sample analysis. The calibration curve range(s) should 

be determined based on the anticipated level of Hg mass on the 

sorbent media. Knowledge of estimated stack Hg concentrations 

and total sample volume may be required prior to analysis. The 

calibration curve for use with the various analytical techniques 

(e.g., UV AA, UV AF, and XRF) can be generated by directly 

introducing standard solutions into the analyzer or by spiking 

the standards onto the sorbent media and then introducing into 

the analyzer after preparing the sorbent/standard according to 

the particular analytical technique. For each calibration curve, 

the value of the square of the linear correlation coefficient, 
Page 364 of 456

i.e., r 2 , must be ≥ 0.99, and the analyzer response must be 

within ±10 percent of reference value at each upscale 

calibration point. Calibrations must be performed on the day of 

the analysis, before analyzing any of the samples. Following 

calibration, an independently prepared standard (not from same 

calibration stock solution) must be analyzed. The measured value 

of the independently prepared standard must be within ±10 

percent of the expected value.

11.2 Sample Preparation. Carefully separate the three 

sections of each sorbent trap. Combine for analysis all 

materials associated with each section, i.e., any supporting 

substrate that the sample gas passes through prior to entering a 

media section (e.g., glass wool, polyurethane foam, etc.) must 

be analyzed with that segment.

11.3 Spike Recovery Study. Before analyzing any field 

samples, the laboratory must demonstrate the ability to recover 

and quantify Hg from the sorbent media by performing the 

following spike recovery study for sorbent media traps spiked 

with elemental mercury. Using the procedures described in 

sections 6.2 and 12.1 of this performance specification, spike 

the third section of nine sorbent traps with gaseous Hg0, i.e.,

three traps at each of three different mass loadings, 

representing the range of masses anticipated in the field 

samples. This will yield a 3 x 3 sample matrix. Prepare and 

analyze the third section of each spiked trap, using the 

techniques that will be used to prepare and analyze the field 

samples. The average recovery for each spike concentration must 

be between 85 and 115 percent. If multiple types of sorbent 

media are to be analyzed, a separate spike recovery study is 

required for each sorbent material. If multiple ranges are 

calibrated, a separate spike recovery study is required for each 

range.

11.4 Field Sample Analyses. Analyze the sorbent trap 

samples following the same procedures that were used for 

conducting the spike recovery study. The three sections of each 

sorbent trap must be analyzed separately (i.e., section 1, then 

section 2, then section 3). Quantify the total mass of Hg for 

each section based on analytical system response and the 

calibration curve from section 11.1 of this performance 

specification. Determine the spike recovery from sorbent trap 

section 3. The spike recovery must be no less than 75 percent 

and no greater than 125 percent. To report the final Hg mass for 

each trap, add together the Hg masses collected in trap sections 

1 and 2.
Page 365 of 456

12.0 Calculations, Data Reduction, and Data Analysis

12.1 Calculation of Pre-Sampling Spiking Level. Determine 

sorbent trap section 3 spiking level using estimates of the 

stack Hg concentration, the target sample flow rate, and the 

expected monitoring period. Calculate Mexp, the expected Hg mass 

that will be collected in section 1 of the trap, using Equation 

12B-1. The pre-sampling spike must be within ± 50 percent of 

this mass. 

 

3

exp 10  M  Q t C x s s est

(Equation 12B-1)

Where:

Mexp = Expected sample mass (μg)

Qs = Sample flow rate (L/min)

ts = Expected monitoring period (min)

Cest = Estimated Hg concentration in stack gas (μg/m3)

10-3 = Conversion factor (m3/L)

Example calculation: For an estimated stack Hg concentration of 

5 μg/m3, a target sample rate of 0.30 L/min, and a monitoring 

period of 5 days: 

Mexp = (0.30 L/min)(1440 min/day)(5 days)(10-3 m

3/L)(5 μg/m3) = 

10.8 μg 

A pre-sampling spike of 10.8 μg ±50 percent is, therefore, 

appropriate.

12.2 Calculations for Flow-Proportional Sampling. For the 

first hour of the data collection period, determine the 

reference ratio of the stack gas volumetric flow rate to the 

sample flow rate, as follows:

ref

ref

ref F

KQ

R = (Equation 12B-2)

Where:

Rref = Reference ratio of hourly stack gas flow rate to

 hourly sample flow rate 

Qref = Average stack gas volumetric flow rate for first hour

 of collection period (scfh) 

Fref = Average sample flow rate for first hour of the

 collection period, in appropriate units (e.g.,
Page 366 of 456

 liters/min, cc/min, dscm/min) 

K = Power of ten multiplier, to keep the value of Rref between 1 

and 100. The appropriate K value will depend on the selected 

units of measure for the sample flow rate. 

Then, for each subsequent hour of the data collection period, 

calculate ratio of the stack gas flow rate to the sample flow 

rate using Equation 12B-3:

 

F

KQ

R = 

h

h

h (Equation 12B-3)

Where: 

Rh = Ratio of hourly stack gas flow rate to hourly sample

 flow rate 

Qh = Average stack gas volumetric flow rate for the hour

 (scfh) 

Fh = Average sample flow rate for the hour, in appropriate units 

(e.g., liters/min, cc/min, dscm/min) 

K = Power of ten multiplier, to keep the value of Rh between 1 

and 100. The appropriate K value will depend on the selected 

units of measure for the sample flow rate and the range of 

expected stack gas flow rates. 

Maintain the value of Rh within ±25 percent of Rref throughout the 

data collection period.

12.3 Calculation of Spike Recovery. Calculate the percent 

recovery of each section 3 spike, as follows:

% 100 3

 

M

M

R = 

s

(Equation 12B-4)

Where: 

%R = Percentage recovery of the pre-sampling spike 

M3 = Mass of Hg recovered from section 3 of the sorbent

 trap, (μg) 

Ms = Calculated Hg mass of the pre-sampling spike, from section 

8.1.2 of this performance specification, (μg)

12.4 Calculation of Breakthrough. Calculate the percent 

breakthrough to the second section of the sorbent trap, as 

follows:

% 100

1

2

 

M

M

B = (Equation 12B-5) 
Page 367 of 456

Where:

%B = Percent breakthrough 

M2 = Mass of Hg recovered from section 2 of the sorbent

 trap, (μg) 

M1 = Mass of Hg recovered from section 1 of the sorbent

 trap, (μg) 

12.5 Calculation of Hg Concentration. Calculate the Hg 

concentration for each sorbent trap, using the following 

equation:

Vt

M

C

*



(Equation 12B-6)

Where: 

C = Concentration of Hg for the collection period,

 (μg/dscm) 

M* = Total mass of Hg recovered from sections 1 and 2 of

 the sorbent trap, (μg) 

Vt = Total volume of dry gas metered during the collection 

period, (dscm). For the purposes of this performance 

specification, standard temperature and pressure are defined 

as 20 C and 760 mm Hg, respectively. 

12.6 Calculation of Paired Trap Agreement. Calculate the 

relative deviation (RD) between the Hg concentrations measured 

with the paired sorbent traps:

x 100

C C

C C

RD

a b

a b







(Equation 12B-7)

Where: 

RD = Relative deviation between the Hg concentrations from

 traps "a" and "b" (percent) 

Ca = Concentration of Hg for the collection period, for

 sorbent trap "a" (μg/dscm) 

Cb = Concentration of Hg for the collection period, for 

 sorbent trap "b" (μg/dscm) 
Page 368 of 456

12.7 Calculation of Relative Accuracy. Calculate the 

relative accuracy as described in Section 12.4 of PS 12A in this 

appendix.

12.8 Data Reduction. Typical monitoring periods for 

normal, day-to-day operation of a sorbent trap monitoring system 

range from about 24 hours to 168 hours. For the required RA

tests of the system, smaller sorbent traps are often used, and 

the ‖monitoring period‖ or time per run is considerably shorter 

(e.g., 1 hour or less). Generally speaking, to validate sorbent 

trap monitoring system data, the acceptance criteria for the 

following five QC specifications in Table 12B-1 above must be 

met for both traps: (a) the post-monitoring leak check; (b) the 

ratio of stack gas flow rate to sample flow rate; (c) section 2 

breakthrough; (d) paired trap agreement; and (e) section 3 spike

recovery. 

12.8.1 For routine day-to-day operation of a sorbent trap 

monitoring system, when both traps meet the acceptance criteria 

for all five QC specifications, the two measured Hg 

concentrations must be averaged arithmetically and the average 

value must be applied to each hour of the data collection 

period. 

12.8.2 To validate a RA test run, both traps must meet the 

acceptance criteria for all five QC specifications. However, as 

specified in Section 12.8.3 below, for routine day-to-day 

operation of the monitoring system, a monitoring period may, in 

certain instances, be validated based on the results from one 

trap. 

12.8.3 For the routine, day-to-day operation of the 

monitoring system, when one of the two sorbent trap samples or 

sampling systems either: (a) fails the post-monitoring leak 

check; or (b) has excessive section 2 breakthrough; or (c) fails 

to maintain the proper stack flow-to-sample flow ratio; or (d) 

fails to achieve the required section 3 spike recovery, provided 

that the other trap meets the acceptance criteria for all four 

of these QC specifications, the Hg concentration measured by the 

valid trap may multiplied by a factor of 1.111 and then used for 

reporting purposes. Further, if both traps meet the acceptance 

criteria for all four of these QC specifications, but the 

acceptance criterion for paired trap agreement is not met, the 

owner or operator may report the higher of the two Hg 

concentrations measured by the traps, in lieu of invalidating 

the data from the paired traps. 
Page 369 of 456

12.8.4 Whenever the data from a pair of sorbent traps must 

be invalidated and no quality-assured data from a certified 

backup Hg monitoring system or Hg reference method are available 

to cover the hours in the data collection period, treat those 

hours in the manner specified in the applicable regulation 

(i.e., use missing data substitution procedures or count the 

hours as monitoring system down time, as appropriate). 

13.0 Monitoring System Performance

These monitoring criteria and procedures have been 

successfully applied to coal-fired utility boilers (including 

units with post-combustion emission controls), having vaporphase Hg concentrations ranging from 0.03 μg/dscm to 

approximately 100 μg/dscm.

14.0 Pollution Prevention [Reserved]

15.0 Waste Management [Reserved]

16.0 Alternative Procedures [Reserved]

17.0 Bibliography

17.1 40 CFR Part 60, Appendix B, ―Performance 

Specification 2 - Specifications and Test Procedures for SO2 and 

NOx Continuous Emission Monitoring Systems in Stationary 

Sources.‖

17.2 40 CFR Part 60, Appendix B, ―Performance 

Specification 12A - Specifications and Test Procedures for Total 

Vapor Phase Mercury Continuous Emission Monitoring Systems in 

Stationary Sources.‖

Appendix F – [Amended]

8. Appendix F to 40 CFR part 60 is amended to add Procedure 

5 to read as follows:

Appendix F to Part 60 – Quality Assurance Procedures

* * * * *

Procedure 5. Quality Assurance Requirements for Vapor Phase 

Mercury Continuous Emissions Monitoring Systems and Sorbent Trap 
Page 370 of 456

Monitoring Systems Used for Compliance Determination at 

Stationary Sources

1.0 Applicability and Principle

1.1 Applicability. The purpose of Procedure 5 is to 

establish the minimum requirements for evaluating the 

effectiveness of quality control (QC) and quality assurance (QA) 

procedures as well as the quality of data produced by vapor 

phase mercury (Hg) continuous emission monitoring systems (CEMS) 

and sorbent trap monitoring systems. Procedure 5 applies to Hg 

CEMS and sorbent trap monitoring systems used for continuously 

determining compliance with emission standards or operating 

permit limits as specified in an applicable regulation or 

permit. Other QA/QC procedures may apply to other auxiliary 

monitoring equipment that may be needed to determine Hg 

emissions in the units of measure specified in an applicable 

permit or regulation.

Procedure 5 covers the measurement of Hg emissions as defined in 

Performance Specification 12A (PS 12A) and Performance 

Specification 12B (PS 12B) in appendix B to this part, i.e., 

total vapor phase Hg representing the sum of the elemental (Hgo, 

CAS Number 7439-97-6) and oxidized (Hg+2) forms of gaseous Hg. 

Procedure 5 specifies the minimum requirements for controlling 

and assessing the quality of Hg CEMS and sorbent trap monitoring 

system data submitted to EPA or a delegated permitting 

authority. You must meet these minimum requirements if you are 

responsible for one or more Hg CEMS or sorbent trap monitoring 

systems used for compliance monitoring. We encourage you to 

develop and implement a more extensive QA program or to continue 

such programs where they already exist.

You must comply with the basic requirements of Procedure 5 

immediately following successful completion of the initial 

performance test described in PS 12A or PS 12B in appendix B to 

this part (as applicable).

1.2 Principle. The QA procedures consist of two distinct 

and equally important functions. One function is the assessment 

of the quality of the Hg CEMS or sorbent trap monitoring system 

data by estimating accuracy. The other function is the control 

and improvement of the quality of the CEMS or sorbent trap 

monitoring system data by implementing QC policies and 

corrective actions. These two functions form a control loop: 

When the assessment function indicates that the data quality is 
Page 371 of 456

inadequate, the quality control effort must be increased until 

the data quality is acceptable. In order to provide uniformity 

in the assessment and reporting of data quality, this procedure

explicitly specifies assessment methods for calibration drift, 

system integrity, and accuracy. Several of the procedures are 

based on those of PS 12A and PS 12B in appendix B to this part. 

Because the control and corrective action function encompasses a 

variety of policies, specifications, standards, and corrective 

measures, this procedure treats QC requirements in general terms 

to allow each source owner or operator to develop a QC system 

that is most effective and efficient for the circumstances.

2.0 Definitions

2.1 Mercury Continuous Emission Monitoring System (Hg 

CEMS) means the equipment required for the determination of the 

total vapor phase Hg concentration in the stack effluent. The 

Hg CEMS consists of the following major subsystems:

2.1.1 Sample Interface means that portion of the CEMS used 

for one or more of the following: sample acquisition, sample 

transport, sample conditioning, and protection of the monitor 

from the effects of the stack effluent.

2.1.2 Hg Analyzer means that portion of the Hg CEMS that 

measures the total vapor phase Hg concentration and generates a 

proportional output.

2.1.3 Data Recorder means that portion of the CEMS that 

provides a permanent electronic record of the analyzer output. 

The data recorder may provide automatic data reduction and CEMS 

control capabilities.

2.2 Sorbent Trap Monitoring System means the total 

equipment required for the collection of gaseous Hg samples 

using paired three-partition sorbent traps as described in PS 

12B in appendix B to this part. 

2.3 Span Value means the measurement range as specified 

for the affected source category in the applicable regulation 

and/or monitoring performance specification.

2.4 Zero, Mid-Level, and High Level Values means the 

reference gas concentrations used for calibration drift 

assessments and system integrity checks on a Hg CEMS, expressed 

as percentages of the span value (see section 7.1 of PS 12A in 

appendix B to this part). 
Page 372 of 456

2.5 Calibration Drift (CD) means the absolute value of the 

difference between the CEMS output response and either the 

upscale Hg reference gas or the zero-level Hg reference gas, 

expressed as a percentage of the span value, when the entire 

CEMS, including the sampling interface, is challenged after a 

stated period of operation during which no unscheduled 

maintenance, repair, or adjustment took place. 

2.6 System Integrity (SI) Check means a test procedure 

assessing transport and measurement of oxidized Hg by a Hg CEMS. 

In particular, system integrity is expressed as the absolute 

value of the difference between the CEMS output response and the 

reference value of either a mid- or high-level mercuric chloride 

(HgCl2) reference gas, as a percentage of span, when the entire 

CEMS, including the sampling interface, is challenged.

2.7 Relative Accuracy (RA) means the absolute mean 

difference between the pollutant concentrations determined by a 

continuous monitoring system (e.g., Hg CEMS or sorbent trap 

monitoring system) and the values determined by a reference 

method (RM) plus the 2.5 percent error confidence coefficient of 

a series of tests divided by the mean of the RM tests. 

Alternatively, for sources with an average RM concentration less 

than 5.0 micrograms per standard cubic meter (μg/scm), the RA 

may be expressed as the absolute value of the difference between 

the mean CEMS and RM values.

2.8 Relative Accuracy Test Audit (RATA) means an audit 

test procedure consisting of at least nine runs, in which the 

accuracy of the total vapor phase Hg concentrations measured by 

a CEMS or sorbent trap monitoring system is evaluated by 

comparison against concurrent measurements made with a reference 

test method. 

2.9 Quarterly Gas Audit (QGA) means an audit procedure in 

which the accuracy of the total vapor phase Hg concentrations 

measured by a CEMS is evaluated by challenging the CEMS with a 

zero and two upscale reference gases.

3.0 QC Requirements

3.1 Each source owner or operator must develop and 

implement a QC program. At a minimum, each QC program must 

include written procedures which should describe in detail, 

complete, step-by-step procedures and operations for each of the 

following activities (as applicable):
Page 373 of 456

(a) Calibration drift (CD) checks of Hg CEMS.

(b) CD determination and adjustment of Hg CEMS.

(c) Weekly system integrity check procedures for Hg CEMS.

(d) Routine operation, maintenance, and QA/QC procedures 

for sorbent trap monitoring systems.

(e) Routine and preventive maintenance procedures for Hg 

CEMS (including spare parts inventory).

(f) Data recording, calculations, and reporting.

(g) Accuracy audit procedures for Hg CEMS and sorbent trap 

monitoring systems including sampling and analysis

methods.

(h) Program of corrective action for malfunctioning Hg CEMS 

and sorbent trap monitoring systems.

These written procedures must be kept on record and available 

for inspection by the responsible enforcement agency. Also, as 

noted in Section 5.2.4, below, whenever excessive inaccuracies 

of a Hg CEMS occur for two consecutive quarters, the source 

owner or operator must revise the current written procedures or 

modify or replace the CEMS or sorbent trap monitoring system to 

correct the deficiency causing the excessive inaccuracies.

4.0 Calibration Drift (CD) Assessment

4.1 CD Requirement. As described in 40 CFR 60.13(d) and 

63.8(c), source owners and operators of Hg CEMS must check, 

record, and quantify the CD at two concentration values at least 

once daily (approximately 24 hours) in accordance with the 

method prescribed by the manufacturer. The Hg CEMS calibration 

must, as minimum, be adjusted whenever the daily zero (or lowlevel) CD or the daily high-level CD exceeds two times the 

limits of the applicable PS in appendix B of this part.

4.2 Recording Requirement for Automatic CD Adjusting CEMS. 

CEMS that automatically adjust the data to the corrected 

calibration values (e.g., microprocessor control) must either be 

programmed to record the unadjusted concentration measured in 

the CD prior to resetting the calibration, if performed, or to 

record the amount of adjustment.
Page 374 of 456

4.3 Criteria for Excessive CD. If either the zero (or lowlevel) or high-level CD result exceeds twice the applicable 

drift specification in section 13.2 of PS 12A in appendix B to 

this part for five, consecutive, daily periods, the CEMS is outof-control. If either the zero (or low-level) or high-level CD 

result exceeds four times the applicable drift specification in 

PS 12A during any CD check, the CEMS is out-of-control. If the 

CEMS is out-of-control, take necessary corrective action. 

Following corrective action, repeat the CD checks.

4.3.1 Out-Of-Control Period Definition. The beginning of 

the out-of-control period is the time corresponding to the 

completion of the fifth, consecutive, daily CD check with a CD 

in excess of two times the allowable limit, or the time 

corresponding to the completion of the daily CD check preceding 

the daily CD check that results in a CD in excess of four times 

the allowable limit. The end of the out-of-control period is the 

time corresponding to the completion of the CD check following 

corrective action that results in the CD's at both the zero (or 

low-level) and high-level measurement points being within the 

corresponding allowable CD limit (i.e., either two times or four 

times the allowable limit in the applicable PS in appendix B).

4.3.2 CEMS Data Status During Out-of-Control Period. 

During the period the CEMS is out-of-control, the CEMS data may 

not be used either to determine compliance with an emission 

limit or to meet a minimum data availability requirement 

specified in an applicable regulation or permit.

5.0 Data Accuracy Assessment

5.1 Hg CEMS Audit Requirements. For each Hg CEMS, an 

accuracy audit must be performed at least once each calendar 

quarter. Successive quarterly audits must, to the extent 

practicable, be performed no less than 2 months apart. The 

audits must be conducted as follows:

5.1.1 Relative Accuracy Test Audit (RATA). A RATA of the 

Hg CEMS must be conducted at least once every four calendar 

quarters, except as otherwise noted in section 5.1.4 of this 

appendix. Perform the RATA as described in section 8.5 of PS 

12A in appendix B to this part. Calculate the results according 

to section 12.4 of PS 12A.

5.1.2 Quarterly Gas Audit. A quarterly gas audit (QGA) 

may be conducted in three of four calendar quarters, but in no 

more than three quarters in succession. To perform a QGA, 
Page 375 of 456

challenge the CEMS with a zero-level and two upscale level audit 

gases of known concentrations, first of elemental Hg and then of 

oxidized Hg, within the following ranges:

Audit point Audit range

1 20 to 30% of span value

2 50 to 60% of span value

Sequentially inject each of the three audit gases (zero and two 

upscale), three times each for a total of nine injections. 

Inject the gases in such a manner that the entire CEMS is 

challenged. Do not inject the same gas concentration twice in 

succession. 

Use elemental Hg and oxidized Hg (mercuric chloride, HgCl2) 

audit gases that are National Institute of Standards and 

Technology (NIST)-certified or NIST-traceable following an EPA 

Traceability Protocol. If audit gas cylinders are used, do not 

dilute gas when challenging the Hg CEMS. For each reference gas 

concentration, determine the average of the three CEMS responses 

and subtract the average response from the reference gas value. 

Calculate the measurement error at each gas level using Equation 

12A-1 in section 8.2 of PS 12A. 

5.1.3 Relative Accuracy Audit (RAA). As an alternative to 

the QGA, a RAA may be conducted in three of four calendar 

quarters, but in no more than three quarters in succession. To 

conduct a RAA, follow the RATA test procedures in section 8.5 of 

PS 12A in appendix B to this part, except that only three test 

runs are required. 

5.1.4 Alternative Quarterly Audits. Alternative quarterly 

audit procedures may be used as approved by the Administrator 

for three of four calendar quarters. One RATA is required at 

least every four calendar quarters, except in the case where the 

affected facility is off-line (does not operate) in the fourth 

calendar quarter since the quarter of the previous RATA. In 

that case, the RATA must be performed in the quarter in which 

the unit recommences operation. Also, quarterly gas audits (or 

RAAs, if applicable) are not required for calendar quarters in 

which the affected facility does not operate.

5.2 Sorbent Trap Monitoring System Audit Requirements. For 

each sorbent trap monitoring system, a RATA must be conducted at 

least once every four calendar quarters, except as otherwise 

noted in section 5.1.4 of this appendix. Perform the RATA as 
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described in section 8.3 of PS 12B in appendix B to this part. 

Calculate the results according to section 12.4 of PS 12A.

5.3 Excessive Audit Inaccuracy. If the results of a RATA, 

QGA, or RAA exceed the applicable criteria in section 5.3.3, the 

Hg CEMS or sorbent trap monitoring system is out-of-control. If 

the Hg CEMS or sorbent trap monitoring system is out-of-control, 

take necessary corrective action to eliminate the problem. 

Following corrective action, the source owner or operator must 

audit the CEMS or sorbent trap monitoring system using the same 

type of test that failed to meet the accuracy criterion. For 

instance, a RATA must always be performed following an out-ofcontrol period resulting from a failed RATA. Whenever audit 

results show the Hg CEMS or sorbent trap monitoring system to be 

out-of-control, the owner or operator must report both the 

results of the failed test and the results of the retest 

following corrective action showing the CEMS to be operating 

within specifications.

5.3.1 Out-Of-Control Period Definition. The beginning of 

the out-of-control period is the hour immediately following the 

completion of a RATA, RAA, QGA or system integrity check that 

fails to meet the applicable performance criteria in section 

5.3.3, below. The end of the out-of-control period is the time 

corresponding to the completion of a subsequent successful test 

of the same type.

5.3.2 Monitoring Data Status During Out-Of-Control Period. 

During the period the monitor is out-of-control, the monitoring 

data may not be used to determine compliance with an applicable 

emission limit or to meet a minimum data availability 

requirement in an applicable regulation or permit.

5.3.3 Criteria for Excessive Audit Inaccuracy. Unless 

specified otherwise in an applicable regulation or permit, the 

criteria for excessive inaccuracy are:

(a) For the RATA, the allowable RA in the applicable PS in 

appendix B (e.g., PS 12A or PS 12B).

(b) For the QGA, ±15 percent of the average audit value or 

±0.5 μg/m3, whichever is greater.

(c) For the RAA, ±20 percent of the three run average or 

±10 percent of the applicable standard, whichever is 

greater.
Page 377 of 456

5.3.4 Criteria for Acceptable QC Procedures. Repeated 

excessive inaccuracies (i.e., out-of-control conditions 

resulting from the quarterly audits) indicates the QC procedures 

are inadequate or that the CEMS or sorbent trap monitoring 

system is incapable of providing quality data. Therefore, 

whenever excessive inaccuracies occur for two consecutive 

quarters, the source owner or operator must revise the QC 

procedures (see Section 3) or modify, repair, or replace the 

CEMS or sorbent trap monitoring system.

6.0 Reporting Requirements

6.1 Data Assessment Report. At the reporting interval 

specified in the applicable regulation or permit, report for 

each Hg CEMS and/or sorbent trap monitoring system the accuracy 

assessment results from Section 5, above. For Hg CEMS, also 

report the CD assessment results from Section 4, above. Report 

this information as a Data Assessment Report (DAR), and include 

the appropriate DAR(s) with the emissions report required under 

the applicable regulation or permit.

6.2 Contents of the DAR. At a minimum, the DAR must 

contain the following information:

6.2.1 Facility name and address including identification 

of source owner/operator.

6.2.2 Identification and location of each Hg CEMS and/or 

sorbent trap monitoring system.

6.2.3 Manufacturer, model, and serial number of each Hg 

CEMS and/or sorbent trap monitoring system.

6.2.4 CD Assessment for each Hg CEMS, including the 

identification of out-of-control periods.

6.2.5 System integrity check data for each Hg CEMS.

6.2.6 Accuracy assessment for each Hg CEMS and/or sorbent 

trap monitoring system, including the identification of out-ofcontrol periods. The results of all required RATAs, QGAs, RAAs, 

and audits of auxiliary equipment must be reported. If an 

accuracy audit shows a CEMS or sorbent trap monitoring system to 

be out-of-control, report both the audit results that caused the 

out-of-control period and the results of the retest following 

corrective action, showing the monitoring system to be operating 

within specifications.
Page 378 of 456

6.2.6. Summary of all corrective actions taken when the Hg 

CEMS and/or sorbent trap monitoring system was determined to be 

out-of-control.

6.3 Data Retention. As required in 40 CFR 60.7(d) and 

63.10(b), all measurements from CEMS and sorbent trap monitoring 

systems, including the quality assurance data required by this 

procedure, must be retained by the source owner for at least 5 

years. 

7.0 Bibliography

7.1 Calculation and Interpretation of Accuracy for Continuous 

Emission Monitoring Systems (CEMS). Section 3.0.7 of the Quality 

Assurance Handbook for Air Pollution Measurement Systems, Volume 

III, Stationary Source Specific Methods. EPA–600/4–77–027b. 

August 1977. U.S. Environmental Protection Agency. Office of 

Research and Development Publications, 26 West St. Clair Street, 

Cincinnati, OH 45268.

PART 63--[AMENDED]

9. The authority citation for part 63 continues to read as 

follows:

Authority: 42 U.S.C. 7401, et seq.

10. Section 63.14 is amended by revising paragraph (b)(54) 

to read as follows:

§63.14 Incorporations by reference.

* * * * *

(b) * * *

(54) ASTM D6348–03, Standard Test Method for Determination 

of Gaseous Compounds by Extractive Direct Interface Fourier 

Transform Infrared (FTIR) Spectroscopy, incorporation by 

reference (IBR) approved for §63.1349(b)(4)(ii) of subpart LLL
Page 379 of 456

and table 4 to subpart DDDD of this part as specified in the 

subpart.

* * * * *

Subpart LLL—[Amended]

11. Section 63.1340 is amended to read as follows:

§63.1340 What parts of my plant does this subpart cover?

(a) The provisions of this subpart apply to each new and 

existing portland cement plant which is a major source or an 

area source as defined in §63.2.

(b) The affected sources subject to this subpart are:

(1) Each kiln including alkali bypasses, except for kilns 

that burn hazardous waste and are subject to and regulated under 

subpart EEE of this part;

(2) Each clinker cooler at any portland cement plant;

(3) Each raw mill at any portland cement plant;

(4) Each finish mill at any Portland cement plant;

(5) Each raw material dryer at any Portland cement plant;

(6) Each raw material, clinker, or finished product 

storage bin at any Portland cement plant;

(7) Each conveying system transfer point including those 

associated with coal preparation used to convey coal from the 

mill to the kiln at any Portland cement plant; 

(8) Each bagging and bulk loading and unloading system at 

any Portland cement plant; and
Page 380 of 456

8) Each open clinker pile at any Portland cement plant.

(c) Crushers are not covered by this subpart regardless of 

their location.

(d) If you are subject to any of the provisions of this 

subpart you are also subject to title V permitting requirements.

12. Section 63.1341 is amended by adding definitions for 

―Affirmative Defense‖, ―Clinker,‖ ―Crusher,‖ ―New source,‖

―sorbent,‖ ―Total organic HAP‖ and ―Totally enclosed conveying 

system transfer point‖ in alphabetic order to read as follows:

§63.1341 Definitions.

* * * * *

Affirmative defense means, in the context of an enforcement 

proceeding, a response or defense put forward by a defendant, 

regarding which the defendant has the burden of proof, and the 

merits of which are independently and objectively evaluated in a 

judicial or administrative proceeding

* * * * *

Clinker means the product of the process in which limestone and 

other materials are heated in the kiln and is then ground with 

gypsum and other materials to form cement.

* * * * *

Crusher means a machine designed to reduce large rocks from the 

quarry into materials approximately the size of gravel. 

* * * * *
Page 381 of 456

Enclosed Storage Pile means any storage pile that is completely 

enclosed in a building or structure consisting of a solid roof 

and walls.

* * * * *

Inactive Clinker Pile is a pile of clinker material that has not 

been disturbed, removed, and/or added to as a result of loading, 

unloading, and/or transferring activities for 30 (thirty) 

consecutive days.

* * * * *

Kiln means a device, including any associated preheater or 

precalciner devices, inline raw mills, or alkali bypasses that 

produces clinker by heating limestone and other materials for 

subsequent production of Portland cement. Because the inline 

raw mill is considered an integral part of the kiln, for 

purposes of determining the appropriate emissions limit, the 

term kiln also applies to the exhaust of the inline raw mill. 

* * * * * 

New source means any source that commenced construction after 

May 6, 2009, for purposes of determining the applicability of 

the kiln, clinker cooler and raw material dryer emissions limits 

for mercury, PM, THC, and HCl, and the requirements for open 

clinker storage piles.

* * * * *
Page 382 of 456

Sorbent means activated carbon, lime, or any other type of 

material injected into kiln exhaust for the purposes of 

capturing and removing any hazardous air pollutant.

* * * * *

Total organic HAP means, for the purposes of this subpart, the 

sum of the concentrations of compounds of formaldehyde, benzene, 

toluene, styrene, m-xylene, p-xylene, o-xylene, acetaldehyde, 

and naphthalene as measured by EPA Test Method 320 of appendix A 

to this part or ASTM D6348-03. Only the measured concentration 

of the listed analytes that are present at concentrations 

exceeding one-half the quantitation limit of the analytical 

method are to be used in the sum. If any of the analytes are 

not detected or are detected at concentrations less than onehalf the quantitation limit of the analytical method, the 

concentration of those analytes will be assumed to be zero for 

the purposes of calculating the total organic HAP for this 

subpart.

* * * * *

Totally enclosed conveying system transfer point means a 

conveying system transfer point that is enclosed on all sides, 

top, and bottom.

* * * * *

13. Section 63.1343 is amended to read as follows:
Page 383 of 456

§63.1343 What Standards Apply to my Kilns, Clinker Coolers, Raw 

Material Dryers, and Open Clinker Piles?

(a) General. The provisions in this section apply to each 

kiln and any alkali bypass associated with that kiln, clinker 

cooler, and raw material dryer. All dioxin D/F, HCl, and total 

hydrocarbon (THC) emission limits are on a dry basis. The D/F, 

HCl and THC limits for kilns are corrected to 7 percent oxygen 

except during periods of startup and shutdown. The raw material 

dryer THC limits are corrected to 19 percent oxygen except 

during startup and shutdown. During startup and shutdown no 

oxygen correction is applied. All (THC) emission limits are 

measured as propane. Standards for mercury, PM, and THC are 

based on a 30-day rolling average, except for periods of startup 

and shutdown, where the standard is based on a 7-day rolling 

average. If using a CEMS to determine compliance with the HCl 

standard, this standard is based on a 30-day rolling average, 

except for periods of startup and shutdown, where the standard 

is based on a 7-day rolling average. You must ensure 

appropriate corrections for moisture are made when measuring 

flowrates used to calculate particulate matter (PM) and mercury

emissions.

b) Kilns, clinker coolers, raw material dryers, raw mills, 

and finish mills. The emission limits for these sources are 

shown in table 1 below.
Page 384 of 456

Table 1. Emissions Limits for Kilns (Rows 1-8), Clinker Coolers (Rows 9-12, Raw Material 

Dryers (Rows 13-15, Raw and Finish Mills (Row 16).

If your 

source is 

And the 

operating 

mode is:

And if is 

located

Your 

emissions 

limits are

And The units of 

the emissions 

limit are

The oxygen 

correction 

factor is:

1. An existing 

kiln 

Normal 

Operation 

At a major 

or area 

source

PM - 0.04 

D/F – 0.21

Mercury – 55

THC - 242,3

lb/ton clinker

ng/dscm

lb/MM tons clinker

ppmvd

NA

7 percent

NA

7 percent

2. An existing 

kiln 

Normal 

Operation 

At a major 

source

HCl - 3 ppmvd 7 percent

3. An existing 

kiln 

Startup and

shutdown

At a major 

or area 

source

PM - 0.007 

D/F – 0.21

Mercury – 10

THC - 242,3

gr/dscf

ng/dscm

ug/dscm

ppmvd

NA

NA

NA

NA

4. An existing 

kiln 

Startup and

shutdown

At a major 

source

HCl - 3

4 ppmvd NA

5. A new kiln Normal 

Operation 

At a major 

or area 

source

PM - 0.01 

D/F – 0.21

Mercury – 21

THC - 242,3

lb/ton clinker

ng/dscm

lb/MM tons clinker

ppmvd

NA

7 percent

NA

7 percent

6. A new kiln Normal 

Operation 

At a major 

source

HCl - 3

4 ppmvd 7 percent

7. A new kiln Startup or 

shutdown

At a major 

or area 

source

PM - 0.0008 

D/F – 0.21

Mercury – 4

THC - 242,3

gr/dscf

ng/dscm

ug/dscm

ppmvd

NA

NA

NA

NA

8. A new kiln Startup and 

shutdown

At a major 

source

HCl - 3 ppmvd NA

9.

An existing 

clinker 

cooler

Normal 

Operation 

At a major 

or area 

source

PM - 0.04 lb/ton clinker NA
Page 385 of 456

10.

An existing 

clinker 

cooler

Startup and 

shutdown

At a major 

or area 

source

PM – 0.004 gr/dscf NA

11.

A new 

clinker 

cooler

Normal 

Operation 

At a major 

or area 

source

PM – 0.01 lb/ton clinker NA

12.

A new 

clinker 

cooler

Startup and 

shutdown

At a major 

or area 

source

PM – 0.0008 gr/dscf NA

13.

An Existing 

or new raw 

material 

dryer

Normal 

Operation 

At a major 

or area 

source

THC - 242,3 ppmvd 7 percent

14.

An Existing 

or new raw 

material 

dryer

Startup and 

shutdown

At a major 

or area 

source

THC - 242,3 ppmvd 7 percent

15.

An Existing 

or new raw 

material 

dryer

All 

operating 

modes

At a major 

source

Opacity - 10 percent NA

16.

An Existing 

or new raw 

or finish 

mill

All 

operating 

modes

Opacity - 10 percent NA

1 If the average temperatures at the inlet to the first particulate matter control device 

(fabric filter or electrostatic precipitator) during the D/F performance test is 400 oF or 

less this limit is changed to 0.04 ng/dscm.

2 Measured as propane.

3 Any source subject to the 24 ppmvd THC limit may elect to meet an alternative limit of 

9 ppmvd for total organic HAP. If the source demonstrates compliance with the total 

organic HAP under the requirements of § 63.1349 then the source‘s THC limit will be 
Page 386 of 456

adjusted to equal the average THC emissions measured during the organic HAP compliance 

test. 

4 If the kiln does not have a HCl CEM the emissions limit is zero.
Page 387 of 456

(2) When there is an alkali bypass associated with a kiln, 

the combined PM emissions from the kiln or in-line kiln/raw mill 

and the alkali bypass stack are subject to the PM emissions 

limit. Existing kilns that combine the clinker cooler exhaust 

with the kiln exhaust for energy efficiency purposes and send 

the combined exhaust to the PM control device as a single stream 

may meet an alternative PM emissions limit. This limit is 

calculated using the equation 1 of this section: 

PM alt = 0.004 x 1.65( x (Qk + Qc)/7000 (Eq. 1)

Where: 0.004 is the PM exhaust concentration (gr/dscf)

equivalent to 0.04 lb per ton clinker where clinker 

cooler and kiln exhaust gas are not combined. 

1.65 is the conversion factor of lb feed per lb 

clinker

Qk is the exhaust flow of the kiln (dscf/ton raw 

feed)

Qc is the exhaust flow of the clinker cooler (dscf/ton 

 raw feed)

For new kilns that combine kiln exhaust and clinker cooler gas 

the limit is calculated using the equation 1 of this section: 

PM alt = 0.0008 x 1.65 x (Qk + Qc)/7000 (Eq. 2)

Where: 0.0008 is the PM exhaust concentration 

(gr/dscf) equivalent to 0.01 lb per ton clinker where 

clinker cooler and kiln exhaust gas are not combined

1.65 is the conversion factor of lb feed per lb 

clinker

Qk is the exhaust flow of the kiln (dscf/ton raw 

feed)

Qc is the exhaust flow of the clinker cooler (dscf/ton 

 raw feed)
Page 388 of 456

(c) If clinker material storage and handling activities 

occur more than 1,000 feet from the facility property-line you 

must comply with the following:

(1) Utilize a three-sided barrier with roof, provided the 

open side is covered with a wind fence material of a maximum 20% 

porosity, allowing a removable opening for vehicle access. The 

removable wind fence for vehicle access may be removed only 

during minor or routine maintenance activities, the creation or 

reclamation of outside storage piles, the importation of clinker 

from outside the facility, and reclamation of plant clean-up 

materials. The removable opening must be less than 50% of the 

total surface area of the wind fence and the amount of time must

be minimized to the extent feasible.

(2) Contain storage and handling of material that is 

immediately adjacent to the three-sided barrier within an area 

next to the structure with a wind fence on at least two sides, 

with at least a 5 foot freeboard above the top of the storage 

pile to provide wind sheltering, and completely cover the 

material with an impervious tarp, revealing only the active 

disturbed portion during material loading and unloading 

activities. 
Page 389 of 456

(3) Storage and handling of other active clinker material 

must be conducted within an area surrounded on three sides by a 

barrier or wind fences with one side of the wind fence facing 

the prevailing wind and at least a 5-foot freeboard above the 

top of the storage pile to provide wind sheltering. The clinker 

must remain completely covered at all times with an impervious 

tarp, revealing only the active disturbed portion during 

material loading and unloading activities. The barrier or wind 

fence must extend at least 20 feet beyond the active portion of 

the material at all times.

(4) Inactive clinker material may be alternatively stored 

using a continuous and impervious tarp, covered at all times, 

provided records are kept demonstrating the inactive status of 

such stored material. 

(d) If clinker material storage and handling activities 

occur 1,000 feet or less from the facility property-line these 

activities must be in an enclosed storage area that meets the 

emissions limits specified in §63.1345.

14. Section 63.1344 is amended to read as follows:

§63.1344 Affirmative Defense for Exceedance of Emission 

Limit During Malfunction.

 In response to an action to enforce the standards set forth 

in paragraph §63.1343(b) you may assert an affirmative defense 

to a claim for civil penalties for exceedances of such standards 
Page 390 of 456

during periods of malfunction, as defined at 40 CFR 63.2. 

Appropriate penalties may be assessed, however, if the 

respondent fails to meet its burden of proving all of the 

requirements in the affirmative defense. The affirmative 

defense shall not be available for claims for injunctive relief.

(a) To establish the affirmative defense in any action to 

enforce such a limit, the owners or operators of facilities must 

timely meet the notification requirements in paragraph (b) of 

this section, and must prove by a preponderance of evidence 

that:

(1) The excess emissions 

(i) Were caused by a sudden, short, infrequent, and 

unavoidable failure of air pollution control and monitoring 

equipment, process equipment, or a process to operate in a 

normal or usual manner, and 

(ii) could not have been prevented through careful 

planning, proper design or better operation and maintenance 

practices; and

 (iii) Did not stem from any activity or event that could 

have been foreseen and avoided, or planned for; and

(iv) Were not part of a recurring pattern indicative of 

inadequate design, operation, or maintenance; and
Page 391 of 456

 (ii) Could not have been avoided by better operation and 

maintenance practices; and

 (2) Repairs were made as expeditiously as possible when the 

applicable emission limitations were being exceeded. Off-shift 

and overtime labor were used, to the extent practicable to make 

these repairs; and

 (3) The frequency, amount and duration of the excess 

emissions (including any bypass) were minimized to the maximum 

extent practicable during periods of such emissions; and

 (4) If the excess emissions resulted from a bypass of 

control equipment or a process, then the bypass was unavoidable 

to prevent loss of life, severe personal injury, or severe 

property damage; and

 (5) All possible steps were taken to minimize the impact of 

the excess emissions on ambient air quality, the environment and 

human health; and

 (6) All emissions monitoring and control systems were kept 

in operation if at all possible; and

 (7) Your actions in response to the excess emissions were 

documented by properly signed, contemporaneous operating logs; 

and
Page 392 of 456

(8) At all times, the facility was operated in a manner 

consistent with good practices for minimizing emissions; and

(9) The owner or operator has prepared a written root cause 

analysis to determine, correct, and eliminate the primary causes 

of the malfunction and the excess emissions resulting from the 

malfunction event at issue. The analysis shall also specify, 

using best monitoring methods and engineering judgment, the 

amount of excess emissions that were the result of the 

malfunction. 

(b) Notification. The owner or operator of the facility 

experiencing an exceedance of its emission limit(s) during a 

malfunction shall notify the Administrator by telephone or 

facsimile (FAX) transmission as soon as possible, but no later 

than two business days after the initial occurrence of the 

malfunction, if it wishes to avail itself of an affirmative 

defense to civil penalties for that malfunction. The owner or 

operator seeking to assert an affirmative defense shall also 

submit a written report to the Administrator within 30 days of 

the initial occurrence of the exceedance of the standard in 

section 63.1343 (b) to demonstrate, with all necessary 

supporting documentation, that it has met the requirements set 

forth in paragraph (a) of this section

15. Section 63.1345 is amended to read as follows:
Page 393 of 456

§63.1345 Emissions Limits for affected sources other than 

kilns; in-line kiln/raw mills; clinker coolers; new and 

reconstructed raw material dryers; and raw and finish mills, and 

open clinker piles.

The owner or operator of each new or existing raw material, 

clinker, or finished product storage bin; conveying system 

transfer point; bagging system; and bulk loading or unloading 

system; and each existing raw material dryer, at a facility 

which is a major source subject to the provisions of this 

subpart must not cause to be discharged any gases from these 

affected sources which exhibit opacity in excess of ten percent.

16. Section 63.1346 is amended to read as follows:

§63.1346 Operating limits for kilns.

(a) The owner or operator of a kiln subject to a D/F 

emission limitation under §63.1343 must operate the kiln such 

that the temperature of the gas at the inlet to the kiln 

particulate matter control device (PMCD) and alkali bypass PMCD, 

if applicable, does not exceed the applicable temperature limit 

specified in paragraph (b) of this section. The owner or 

operator of an in-line kiln/raw mill subject to a D/F emission 

limitation under §63.1343 must operate the in-line kiln/raw 

mill, such that:

(1) When the raw mill of the in-line kiln/raw mill is 

operating, the applicable temperature limit for the main in-line 
Page 394 of 456

kiln/raw mill exhaust, specified in paragraph (b) of this 

section and established during the performance test when the raw 

mill was operating is not exceeded, except during periods of 

startup/shutdown when the temperature limit may be exceeded by 

no more than 10 percent.

(2) When the raw mill of the in-line kiln/raw mill is not 

operating, the applicable temperature limit for the main in-line 

kiln/raw mill exhaust, specified in paragraph (b) of this 

section and established during the performance test when the raw 

mill was not operating, is not exceeded, except during periods 

of startup/shutdown when the temperature limit may be exceeded 

by no more than 10 percent.

(3) If the in-line kiln/raw mill is equipped with an alkali 

bypass, the applicable temperature limit for the alkali bypass 

specified in paragraph (b) of this section and established 

during the performance test, with or without the raw mill 

operating, is not exceeded, except during periods of 

startup/shutdown when the temperature limit may be exceeded by 

no more than 10 percent.

(b) The temperature limit for affected sources meeting the 

limits of paragraph (a) of this section or paragraphs (a)(1) 

through (a)(3) of this section is determined in accordance with 

§63.1349(b)(3)(iv).
Page 395 of 456

(c) For an affected source subject to a D/F emission 

limitation under §63.1343 that employs sorbent injection as an 

emission control technique you must operate the sorbent

injection system in accordance with paragraphs (c)(1) and (c)(2) 

of this section.

(1) The three-hour rolling average activated sorbent

injection rate must be equal to or greater than the sorbent 

injection rate determined in accordance with §63.1349(b)(3)(vi).

(2) You must either:

(i) Maintain the minimum activated carbon injection carrier 

gas flow rate, as a three-hour rolling average, based on the 

manufacturer's specifications. These specifications must be 

documented in the test plan developed in accordance with 

§63.7(c), or

(ii) Maintain the minimum activated carbon injection 

carrier gas pressure drop, as a three-hour rolling average, 

based on the manufacturer's specifications. These specifications 

must be documented in the test plan developed in accordance with 

§63.7(c).

(d) Except as provided in paragraph (e) of this section, 

for an affected source subject to a D/F emission limitation 

under §63.1343 that employs carbon injection as an emission 

control technique you must specify and use the brand and type of 

sorbent used during the performance test until a subsequent 
Page 396 of 456

performance test is conducted, unless the site-specific 

performance test plan contains documentation of key parameters 

that affect adsorption and the owner or operator establishes 

limits based on those parameters, and the limits on these 

parameters are maintained.

(e) For an affected source subject to a D/F emission 

limitation under §63.1343 that employs carbon injection as an 

emission control technique you may substitute, at any time, a 

different brand or type of sorbent provided that the replacement 

has equivalent or improved properties compared to the sorbent 

specified in the site-specific performance test plan and used in 

the performance test. The owner or operator must maintain 

documentation that the substitute sorbent will provide the same 

or better level of control as the original sorbent.

f) No kiln may use as a raw material or fuel any fly ash 

where the mercury content of the fly ash has been increased 

through the use of activated carbon, or any other sorbent,

unless the facility can demonstrate that the use of that fly ash 

will not result in an increase in mercury emissions over 

baseline emissions (i.e., emissions not using the fly ash). The 

facility has the burden of proving there has been no emissions 

increase over baseline. Once the kiln must comply with with a

mercury limit specified in §63.1343, this paragraph no longer 

applies. 
Page 397 of 456

17. Section 63.1347 is amended to read as follows:

§ 63.1347 Operation and Maintenance Plan Requirements.

(a) You must prepare, for each affected source subject to the 

provisions of this subpart, a written operations and maintenance 

plan. The plan must be submitted to the Administrator for 

review and approval as part of the application for a part 70 

permit and must include the following information:

(1) Procedures for proper operation and maintenance of the 

affected source and air pollution control devices in order to 

meet the emission limits and operating limits of §§63.1343 

through 63.1348;

(2) Corrective actions to be taken when required by paragraph 

§63.1350(f)(3);

(3) Procedures to be used during an inspection of the components 

of the combustion system of each kiln and each in-line kiln raw 

mill located at the facility at least once per year.

(b) Failure to comply with any provision of the operations 

and maintenance plan developed in accordance with this section 

must be a violation of the standard.

18. Section 63.1348 is amended to read as follows:

§ 63.1348 Compliance Requirements.

(a) Initial Compliance Requirements. For an affected source 

subject to this subpart you must demonstrate initial compliance 
Page 398 of 456

with the emissions standards and operating limits by using the 

test methods and procedures in §§63.1349 and 63.7.

(1) PM Compliance. For an affected source subject to limitations 

on PM emissions under §63.1343(b)(1) and (c)(1) and §63.1345(a) 

you must demonstrate initial compliance with the PM emissions 

standards by using the test methods and procedures in 

§63.1349(b)(1). 

(i) For an affected source subject to limitations on PM 

emissions you must demonstrate initial compliance by conducting 

a performance test as specified in §63.1349(b)(1)(i).

(ii) Compliance with the PM emissions standard must be 

determined based on the first calendar month you operate a PM

CEMS. 

(2) Opacity Compliance. For an affected source subject to 

the limitations on opacity under §§63.1346(a)(1), 63.1347, 

and/or 63.1348 you must demonstrate initial compliance with the 

opacity emissions standards by using the performance test

methods and procedures in §63.1349(b)(2). The maximum 6-minute 

average opacity exhibited during the performance test period 

must be used to determine whether the affected source is in 

initial compliance with the standard.

(3) D/F Compliance. 

(i) For an affected source subject to limitations on D/F 

emissions under §63.1343(b)(2) and (c)(2) you must demonstrate 
Page 399 of 456

initial compliance with the D/F emissions standards by using the 

performance test methods and procedures in §63.1349(b)(3). The 

owner or operator of a kiln with an in-line raw mill must

demonstrate initial compliance by conducting separate 

performance tests while the raw mill is operating and the raw 

mill is not operating. The D/F concentration must be determined 

for each run and the arithmetic average of the concentrations 

measured for the three runs must be calculated to determine 

compliance.

(ii) For an affected source subject to a D/F emission 

limitation under §63.1343(b)(2) and (c)(2) you must demonstrate 

initial compliance with the temperature operating limits 

specified in §63.1344 by using the performance test methods and 

procedures in §63.1349(b)(3)(ii) through (b)(3)(iv). The 

average of the run temperatures will determine the applicable 

temperature limit.

(iii) If activated carbon injection is used, for an 

affected source subject to a D/F emission limitation under 

§63.1343(b)(2) and (c)(2) you must demonstrate initial 

compliance with the activated carbon injection rate operating 

limits specified in §63.1344 by using the performance test

methods and procedures in §63.1349(b)(3)(v). The average of the 

run injection rates will determine the applicable injection rate 

limit.
Page 400 of 456

(iv) If activated carbon injection is used, you must also 

develop a carrier gas parameter during the performance test 

conducted under §63.1349(b)(3) that meets the requirements of 

§63.1349(b)(3)(vi). Compliance is demonstrated if the system is 

maintained within +/- 5 percent accuracy during the performance 

test.

(4)(i) THC Compliance. For an affected source subject to 

limitations on THC emissions under §63.1343(b)(3) and (c)(3) and 

§63.1346(a)(2) you must demonstrate initial compliance with the 

THC emissions standards by using the performance test methods 

and procedures in §63.1349(b)(4)(i). The average THC 

concentration obtained during the the first 30 calendar days 

must be used to determine initial compliance. 

(ii) Total Organic HAP Emissions Tests. If you elect to 

demonstrate compliance with the total organic HAP emissions 

limit under §63.1343(b)(3) and (c)(3) and §63.1346(a)(2) in lieu 

of the THC emissions limit, you must demonstrate initial 

compliance with the total organic HAP emissions standards by 

using the performance test methods and procedures in 

§63.1349(b)(4)(iii) and (b)(4)(iv). 

(iii) For kilns demonstrating initial compliance by 

conducting separate performance tests as specified in 

§63.1349(b)(4)(iii) while the raw mill kiln is operating and 

while the raw mill of the kiln is not operating.
Page 401 of 456

(iv) The average total organic HAP concentration measured 

during the initial performance test specified by 

§63.1349(b)(4)(iii) will be used to determine initial 

compliance.

(v) The average THC concentration measured during the 

initial performance test specified by §63.1349(b)(4)(iv) will be 

used to determine the site-specific THC limit.

(5) Mercury Compliance. For affected source subject to 

limitations on mercury emissions in §63.1343(b)(4) and (c)(4) 

you must demonstrate initial compliance with the mercury 

standards by using the performance test methods and procedures 

in §63.1349(b)(5). The owner or operator of an affected source 

must demonstrate initial compliance by operating a mercury CEMS 

or a sorbent trap based integrated monitor. The first 30 

calendar days of daily mercury concentration data will be used

to determine initial compliance.

(6) HCl Compliance. For affected source subject to 

limitations on HCl emissions under §63.1343(b)(5) and (c)(5) you 

must demonstrate initial compliance with the HCl standards by 

using the performance test methods and procedures in 

§63.1349(b)(6). 

(i) For an affected source that is equipped with a wet 

scrubber or tray tower you must demonstrate initial compliance 

by conducting a performance test as specified in 
Page 402 of 456

§63.1349(b)(6)(i). The HCl concentration must be determined for 

each run and the arithmetic average of the concentrations 

measured for the three runs must be calculated to determine 

compliance. The owner or operator must also have established 

appropriate site-specific parameter limits.

(ii) For an affected source that is not equipped with a wet 

scrubber or tray tower you must demonstrate initial compliance 

by operating a CEMS as specified in §63.1349(b)(6)(ii). The 

average hourly HCl concentration obtained during the first 30 

calendar days must be used to determine initial compliance.

(b) Continuous Compliance Requirements. You must

demonstrate continuous compliance with the emissions standards 

and operating limits by using the performance test methods and 

procedures in §§63.1350 and 63.8 for each affected source.

(1) General Requirements. 

(i) You must monitor and collect data according to §63.1350 

and the site-specific monitoring plan required by §63.1350(o).

(ii) Except for periods of monitoring system malfunctions, 

repairs associated with monitoring system malfunctions, and 

required monitoring system quality assurance or quality control 

activities (including, as applicable, calibration checks and 

required zero and span adjustments), you must operate the 

monitoring system and collect data at all required intervals at 

all times the affected source is operating. Any period for 
Page 403 of 456

which data collection is required and the operation of the CEMS 

is not otherwise exempt and for which the monitoring system is 

out-of-control and data are not available for required 

calculations constitutes a deviation from the monitoring 

requirements.

(iii) You may not use data recorded during monitoring 

system malfunctions, repairs associated with monitoring system 

malfunctions, or required monitoring system quality assurance or 

control activities in calculations used to report emissions or 

operating levels. A monitoring system malfunction is any 

sudden, infrequent, not reasonably preventable failure of the 

monitoring system to provide valid data. Monitoring system 

failures that are caused in part by poor maintenance or careless 

operation are not malfunctions. The owner or operator must use 

all the data collected during all other periods in assessing the 

operation of the control device and associated control system

(iv) Clinker Production. For an affected source subject to 

limitations on PM emissions (lb/ton of clinker) or mercury 

(lb/MM tons of clinker) under §63.1343(b)(1) and (c)(1) you must

demonstrate continuous compliance with the PM emissions 

standards by installing, operating, and maintaining a permanent 

weigh scale system to measure and record weight rates of the 

amount of clinker produced that meets the requirements of 

§63.1350(d).
Page 404 of 456

(2) PM Compliance. For an affected source subject to 

limitations on PM emissions under §63.1343(b)(1) and (c)(1) and 

§63.1345 you must demonstrate continuous compliance with the 

with the PM emissions standards by using the monitoring methods 

and procedures in §63.1350(b) and (d). 

(i) PM CEMS. You must demonstrate continuous compliance 

with the PM emissions standards by using the monitoring methods 

and procedures in §§63.1350(b) for each affected source subject 

to PM emissions limitations. Continuous compliance is 

demonstrated by a 30-day rolling average PM concentration,

except for periods of startup and shutdown, where the compliance

is demonstrated based on a 7-day rolling average.

6(3) Opacity Compliance. For an affected source subject to 

the limitations on opacity under §§63.1345 you must demonstrate 

continuous compliance with the opacity emissions standards by 

using the monitoring methods and procedures in §63.1350(f). 

(i) Continuous compliance is demonstrated by conducting 

specified visible emissions observations and follow up opacity 

readings, as indicated in §63.1350(f)(1) and (f)(2). The 

maximum 6-minute average opacity exhibited during the 

performance test period must be used to determine whether the 

affected source is in compliance with the standard. Corrective 
Page 405 of 456

actions must be initiated within one hour of detecting visible 

emissions.

(ii) COMS. If you install a COMS in lieu of conducting the 

daily visible emissions testing, you must demonstrate continuous 

compliance by operating and maintaining the COMS so that it 

meets the requirements of §63.1350(f)(4)(i).

(iii) BLDS. If you install a BLDS on a raw mill or finish 

mill in lieu of conducting the daily visible emissions testing, 

you must demonstrate continuous compliance by operating and 

maintaining the BLDS so that it meets the requirements of 

§63.1350(f)(4)(ii).

(4) D/F Compliance. For an affected source subject to a D/F 

emission limitation under §63.1343(b) you must demonstrate 

continuous compliance with the temperature operating limits 

specified in §63.1346 by using the installing, operating, and 

maintaining a continuous monitor to record the temperature of 

specified gas streams so that it meets the requirements of 

§63.1350(g). Continuous compliance is demonstrated by a 3-hour 

rolling average temperature.

(5)(i) Activated Carbon Injection Compliance. If activated 

carbon injection is used, for a kiln subject to a D/F emission 

limitation under §63.1343(b) you must demonstrate continuous 

compliance with the activated carbon injection rate operating 

limits specified in §63.1346 by installing, operating, and 
Page 406 of 456

maintaining a continuous monitor to record the rate of activated 

carbon injection that meets the requirements §63.1350(h)(1). 

Continuous compliance is demonstrated by a 3-hour rolling 

average injection rate.

(ii) For a kiln subject to a D/F emission limitation under 

§63.1343(b) you must demonstrate continuous compliance with the 

activated carbon injection system gas parameter by installing, 

operating, and maintaining a continuous monitor to record the 

gas parameter that meets the requirements §63.1350(h)(2). 

Continuous compliance is demonstrated by a 3-hour rolling 

average of the parameter value.

(6) THC Compliance. For an affected source subject to 

limitations on THC emissions under §63.1343(b) you must

demonstrate continuous compliance with the THC emissions 

standards by using the monitoring methods and procedures in 

§63.1350 (i) and (j). Continuous compliance is demonstrated by 

a 30-day rolling average THC concentration, except for periods 

of startup and shutdown, where the standard is based on a 7-day 

rolling average.

(7) Mercury Compliance. For a source subject to limitations 

on mercury emissions in §63.1343(b) you must demonstrate

continuous compliance with the mercury standards by using the 

monitoring methods and procedures in §63.1350(k). Continuous 

compliance is demonstrated by a 30-day rolling average mercury 
Page 407 of 456

concentration, except for periods of startup and shutdown, where 

the standard is based on a 7-day rolling average.

(8) HCl Compliance. For an affected source subject to 

limitations on HCl emissions under §63.1343(b) you must

demonstrate initial compliance with the HCl standards by using 

the performance test methods and procedures in §63.1349(b)(6). 

(i) For an affected source that is not equipped with a wet 

scrubber or tray tower you must demonstrate continuous

compliance by using the monitoring methods and procedures in 

§63.1350(l)(1). Continuous compliance is demonstrated by a 30-

day rolling average HCl concentration, except for periods of 

startup and shutdown, where the standard is based on a 7-day 

rolling average.

(ii) For an affected source that is equipped with a wet 

scrubber or tray tower you must demonstrate continuous

compliance by using the monitoring methods and procedures in 

§63.1350(l)(2). Continuous compliance is demonstrated by a 30-

day rolling average of the required parameters, except for 

periods of startup and shutdown, where the standard is based on 

a 7-day rolling average.

(c) Changes in Operations.

(1) If you plan to undertake a change in operations that 

may adversely affect compliance with an applicable standard,

operating limit, or parametric monitoring value under this 
Page 408 of 456

subpart, the source must conduct a performance test as specified 

in §63.1349(b).

(2) In preparation for and while conducting a performance 

test required in §63.1349(b), you may operate under the planned 

operational change conditions for a period not to exceed 360 

hours, provided that the conditions in (c)(2)(i) through 

(c)(2)(iv) of this section are met. You must submit temperature 

and other monitoring data that are recorded during the pretest 

operations.

(i) You must provide the Administrator written notice at 

least 60 days prior to undertaking an operational change that 

may adversely affect compliance with an applicable standard 

under this subpart for any source, or as soon as practicable 

where 60 days advance notice is not feasible. Notice provided 

under this paragraph must include a description of the planned 

change, the emissions standards that may be affected by the 

change, and a schedule for completion of the performance test 

required under paragraph (c)(1) of this section, including when 

the planned operational change period would begin.

(ii) The performance test results must be documented in a 

test report according to §63.1349 (a).

(iii) A test plan must be made available to the 

Administrator prior to performance testing, if requested.
Page 409 of 456

(iv) The performance test must be conducted completed 

within 360 hours after the planned operational change period 

begins.

(d) General Duty to Comply. 

At all times you must operate and maintain any affected 

source, including associated air pollution control equipment and 

monitoring equipment, in a manner consistent with safety and 

good air pollution control practices for minimizing emissions. 

Determination of whether such operation and maintenance 

procedures are being used will be based on information available 

to the Administrator which may include, but is not limited to, 

monitoring results, review of operation and maintenance 

procedures, review of operation and maintenance records, and 

inspection of the source.

19. Section 63.1349 is amended to read as

§ 63.1349 Performance testing requirements.

(a) Performance test results must be documented in complete 

test reports that contain the information required by paragraphs 

(a)(1) through (a)(10) of this section, as well as all other 

relevant information. As described in §63.7(c)(2)(i), the sitespecific plan to be followed during performance testing must be 

made available to the Administrator prior to testing, if 

requested.
Page 410 of 456

(1) A brief description of the process and the air 

pollution control system;

(2) Sampling location description(s);

(3) A description of sampling and analytical procedures and 

any modifications to standard procedures;

(4) Test results;

(5) Quality assurance procedures and results;

(6) Records of operating conditions during the performance 

test, preparation of standards, and calibration procedures;

(7) Raw data sheets for field sampling and field and 

laboratory analyses;

(8) Documentation of calculations;

(9) All data recorded and used to establish parameters for 

monitoring; and

(10) Any other information required by the performance test

method.

(b)(1) PM Emissions Tests. 

(i)(A) The owner or operator of an affected source subject 

to the limitations on emissions of PM must install, operate, 

calibrate, and maintain a PM CEMS in accordance with the 

requirements in §63.1350(b).

(B) You must determine, record, and maintain a record of 

the accuracy of the volumetric flow rate monitoring system 

according to the procedures in §63.1350(m)(5).
Page 411 of 456

(C) The initial compliance test must be based on the first 

calendar month of operation in which the affected source

operates using a CEMS. Hourly PM concentration and stack gas 

volumetric flow rate data must be obtained.

(ii) You must determine the clinker production rate using 

the methods in §63.1350(d). 

(iii) The emission rate, E, of PM (lb/ton of clinker) must

be computed for each run using equation 3 of this section:

 

ton

(Cs Qsd) lb

 

K P

E Equation 3

Where:

E = emission rate of particulate matter, lb/ton of clinker 

production;

Cs= concentration of particulate matter, gr/dscf;

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

P = total kiln clinker production rate, ton/hr; and

K = conversion factor, 7000 gr/lb.

(iv) When there is an alkali bypass associated with a kiln, 

the main exhaust and alkali bypass of the kiln must be tested 

simultaneously and the combined emission rate of particulate 

matter from the kiln and alkali bypass must be computed for each 

computed for each run using equation 4 of this section:

 

K P

[(Csk sdk) (Cab Qsdb)] Ec 



Q

(Eq. 4)

Where:

Ec= combined emission rate of particulate matter from the kiln or 

in-line kiln/raw mill and bypass stack, lb/ton of kiln clinker 

production;
Page 412 of 456

Csk= concentration of particulate matter in the kiln or in-line 

kiln/raw mill effluent gas, gr/dscf;

Qsdk= volumetric flow rate of kiln or in-line kiln/raw mill 

effluent gas, dscf/hr;

Csb= concentration of particulate matter in the alkali bypass 

gas, gr/dscf;

Qsdb= volumetric flow rate of alkali bypass effluent gas, 

dscf/hr;

P= total kiln clinker production rate, ton/hr; and

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

(2) Opacity Tests. For an affected source subject to 

limitations on opacity under this subpart you must conduct 

opacity tests in accordance with Method 9 of appendix A-4 to 

part 60 of this chapter. The duration of the Method 9 

performance test must be 3 hours (30 6-minute averages), except 

that the duration of the Method 9 performance test may be 

reduced to 1 hour if the conditions of paragraphs (b)(2)(i) 

through (b)(2)(ii) of this section apply. For batch processes 

that are not run for 3-hour periods or longer, compile 

observations totaling 3 hours when the unit is operating.

(i) There are no individual readings greater than 10 

percent opacity;

(ii) There are no more than three readings of 10 percent 

for the first 1-hour period.

(3) D/F Emissions Tests. For a source subject to 

limitations on D/F emissions under this subpart you must conduct 

a performance test using Method 23 of appendix A-7 to part 60 of 

this chapter. The owner or operator of a kiln or in-line 
Page 413 of 456

kiln/raw mill equipped with an alkali bypass must conduct 

simultaneous performance tests of the kiln or in-line kiln/raw 

mill exhaust and the alkali bypass. However, the owner or 

operator of an in-line kiln/raw mill may conduct a performance 

test of the alkali bypass exhaust when the raw mill of the inline kiln/raw mill is operating or not operating. 

(i) Each performance test must consist of three separate 

runs conducted under representative conditions. The duration of 

each run must be at least 3 hours, and the sample volume for 

each run must be at least 2.5 dscm (90 dscf).

(ii) The temperature at the inlet to the kiln or in-line 

kiln/raw mill PMCD, and, where applicable, the temperature at 

the inlet to the alkali bypass PMCD must be continuously 

recorded during the period of the Method 23 test, and the 

continuous temperature record(s) must be included in the 

performance test report.

(iii) Hourly average temperatures must be calculated for 

each run of the performance test.

(iv) The run average temperature must be calculated for 

each run, and the average of the run average temperatures must 

be determined and included in the performance test report and 

will determine the applicable temperature limit in accordance 

with §63.1344(b).
Page 414 of 456

(v)(A) If sorbent injection is used for D/F control, the 

rate of sorbent injection to the kiln or in-line kiln/raw mill 

exhaust, and where applicable, the rate of sorbent injection to 

the alkali bypass exhaust, must be continuously recorded during 

the period of the Method 23 test in accordance with the 

conditions in §63.1350(m)(9), and the continuous injection rate 

record(s) must be included in the performance test report. 

Sorbent injection rate parameters must be determined in 

accordance with paragraphs (b)(3)(vi) of this section.

(B) The performance test report must include the brand and 

type of sorbent used during the performance test.

(C) The owner or operator must maintain a continuous record 

of either the carrier gas flow rate or the carrier gas pressure 

drop for the duration of the performance test. If the carrier 

gas flow rate is used, the owner or operator must determine, 

record, and maintain a record of the accuracy of the carrier gas 

flow rate monitoring system according to the procedures in 

appendix A to part 75 of this chapter. If the carrier gas 

pressure drop is used, the owner or operator must determine, 

record, and maintain a record of the accuracy of the carrier gas 

pressure drop monitoring system according to the procedures in 

§63.1350(m)(6). 

(vi) The run average sorbent injection rate must be 

calculated for each run and the average of the run average 
Page 415 of 456

injection rates must be determined and included in the 

performance test report and will determine the applicable 

injection rate limit in accordance with §63.1344(c)(1).

(4)(i) THC CEMS Relative Accuracy Test. 

(A) For an affected source subject to limitations on THC 

emissions you must operate a continuous emissions monitoring 

system (CEMS) in accordance with the requirements in 

§63.1350(1). For the purposes of conducting the accuracy and 

quality assurance evaluations for CEMS, the THC span value (as 

propane) is 50 ppmvd. An owner or operator demonstrates 

compliance with a RATA when the accuracy between the CEMS and 

the test audit is within 20 percent or when the test audit 

results are within 10 percent of the standard 

(B) The initial compliance test must be based on the first 

30 calendar days of operation in which the affected source

operates using a CEMS. 

(ii) Total Organic HAP Emissions Tests. Instead of 

conducting the performance test specified in paragraph 

(b)(4)(i), the for an affected source subject to limitations on 

THC emissions you may conduct a performance test to determine 

emissions of total organic HAP, by following the procedures in 

paragraphs (b)(4)(iii) through (b)(4)(iv) of this section.

(iii) Method 320 of appendix A to this part or ASTM D6348-

03 must be used to determine emissions of total organic HAP. 
Page 416 of 456

Each performance test must consist of three separate runs under 

the conditions that exist when the affected source is operating 

at the representative performance conditions in accordance with 

§63.7(e). Each run must be conducted for at least 1 hour. 

(iv) At the same time that you are conducting the 

performance test for total organic HAP, you must also determine 

THC emissions by operating a CEMS in accordance with the 

requirements of §63.1350(j). The duration of the performance 

test must be 3 hours and the average THC concentration (as 

calculated from the 1-minute averages) during the 3-hour test 

must be calculated.

(5) Mercury Emissions Tests. For a kiln subject to 

limitations on mercury emissions you must operate a mercury CEMS 

in accordance with the requirements of §63.1350(k). The initial 

compliance test must be based on the first calendar month of 

operation in which the affected source operates using a CEMS. 

Hourly mercury concentration and stack gas volumetric flow rate 

data must be obtained. If the source uses a sorbent trap 

monitoring system, daily data must be obtained with each day 

assumed to equal the daily average of the sorbent trap 

collection period covering that day. 

(i) If you are using a mercury CEMS you must install, 

operate, calibrate, and maintain an instrument for continuously 
Page 417 of 456

measuring and recording the exhaust gas flow rate to the 

atmosphere according to the requirements in§63.1350(k)(4).

(ii) The emission rate must be computed by dividing the 

average mercury concentration by the clinker production rate 

during the same calendar month using the Equation 3 of this 

section:

 

E (C Q )/(PK) 

s sd (Eq. 5)

Where: 

E = emission rate of mercury, lb/million tons of clinker 

production; 

Cs = concentration of mercury, g/dscm;

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

P = total kiln clinker production rate, million ton/hr; and

K = conversion factor, 1000 g/kg (454 g/lb).

(6) HCl Emissions Tests. For a source subject to 

limitations on HCl emissions you must conduct performance 

testing by one of the following methods:

(i)(A) If the source is equipped with a wet scrubber, or 

tray tower, you must conduct performance testing using Method 

321 of appendix A to this part unless you have installed a CEMS 

that meets the requirements §63.1350(l)(1) . 

(B) You must establish site specific parameter limits by 

using the CPMS required in§63.1350(l)(1). Measure and record 

the pressure drop across the scrubber and/or liquid flow rate 

and pH in intervals of no more than 15 minutes during the HCl 

test. Compute and record the 24-hour average pressure drop , 
Page 418 of 456

pH, and average scrubber water flow rate for each sampling run 

in which the applicable emissions limit is met.

(ii)(A) If the source is not controlled by a wet scrubber, 

you must operate a CEMS in accordance with the requirements of 

§63.1350(l)(1). The initial performance test must be the first 

30 calendar days you operate the CEMS. (B) The initial 

compliance test must be based on the 24 hours of operation in 

which the affected source operates using a CEMS. Hourly HCl 

concentration and stack gas volumetric flow rate data must be 

obtained.

(c) Performance Test Frequency. Except as provided in 

§63.1348(b), performance tests are required for affected sources 

that are subject to a dioxin, total organic HAP, or HCl, 

emissions limit and must be repeated every 30 months except for 

pollutants where that specific pollutant is monitored using

CEMS.

(d) Performance Test Reporting Requirements. 

(1) For an affected facility must submit the information 

specified in paragraphs (d)(1)(i) and (d)(2) of this section no 

later than 60 days following the initial performance test. All 

reports must be signed by the facilities manager.

(i) The initial performance test data as recorded under 

paragraph (b) of this section.
Page 419 of 456

(ii) The values for the site-specific operating limits or 

parameters established pursuant to paragraphs (b)(3), 

(b)(4)(iii), (b)(5)(ii), and (b)(6)(i), as applicable, and a 

description, including sample calculations, of how the operating 

parameters were established during the initial performance test. 

(2) As of December 31, 2011 and within 60 days after the 

date of completing each performance evaluation or test, as 

defined in §63.2, conducted to demonstrate compliance with this 

subpart, the owner or operator of an affected facility must 

submit the relative accuracy test audit data and performance 

test data, except opacity data, to EPA by successfully 

submitting the data electronically to EPA‘s Central Data 

Exchange (CDX) by using the Electronic Reporting Tool(ERT) (see 

http://www.epa.gov/ttn/chief/ert/ert_tool.html/).

(e) Performance tests shall be conducted under such 

conditions as the Administrator specifies to the owner or 

operator based on representative of the affected source for the 

period being tested. Upon request, the owner or operator shall 

make available to the Administrator such records as may be 

necessary to determine the conditions of performance tests.

20. Section 63.1350 is amended to read as follows:

§ 63.1350 Monitoring requirements.
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(a) All continuous monitoring data for periods of startup 

and shutdown must be compiled and averaged separately from data 

gathered during periods of normal operation or malfunction.

(b) PM Monitoring Requirements for Sources Using PM CEMS. 

(1) The owner or operator of a kiln or clinker cooler 

subject to emissions limitation on particulate matter emissions 

in §63.1343 and §63.1345 using a PM CEMS must install and 

operate a continuous emissions monitor in accordance with 

Performance Specification 11 of appendix B and Procedure 2 of 

appendix F to part 60 of this chapter. The performance test 

method and the correlation test method for Performance 

Specification 11 shall be Method 5 or Method 5i of appendix A to 

Part 60 of this chapter. The owner or operator must also 

develop an emissions monitoring plan in accordance with 

paragraphs (o)(1) through (o)(4) of this section.

(2) The owner or operator must perform Relative Response 

Audits annually and Response Correlation Audits every 3 years.

(3) If you are using a PM CEMS, you must install, operate, 

calibrate, and maintain an instrument for continuously measuring 

and recording the exhaust gas flow rate to the atmosphere 

according to the requirements in paragraphs (n)(1) through 

(n)(10) of this section.

(4) In order to calculate the 30-day or 7-day rolling 

average, collect readings at least every 15 minutes. Sum the 
Page 421 of 456

hourly data to daily data and then into a 30-day rolling 

average. You must use all data, except those recorded during 

monitoring system malfunctions, repairs associated with 

monitoring system malfunctions, or required monitoring system 

quality assurance or control activities, in calculations. 

(c) Reserved

(d) Clinker Production Monitoring Requirements. For any 

kiln subject to an emissions limitation on particulate matter, 

NOx, or SO2 emissions (lb/ton of clinker), you must

(1) Determine hourly clinker production by one of two 

methods:

(i) Install, calibrate, maintain, and operate a permanent 

weigh scale system to measure and record weight rates in tonsmass per hour of the amount of clinker produced. The system of 

measuring hourly clinker production must be maintained within ±5 

percent accuracy. 

(ii) Install, calibrate, maintain, and operate a permanent 

weigh scale system to measure and record weight rates in tonsmass per hour of the amount of feed to the kiln. The system of 

measuring feed must be maintained within ±5 percent accuracy. 

Calculate your hourly clinker production rate using a kiln 

specific feed to clinker ratio based on reconciled clinker 

production determined for accounting purposes and recorded feed 

rates. This ratio should be updated monthly. Note that if this 
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ratio changes at clinker reconciliation, you must use the new 

ratio going forward, but you do not have to retroactively change 

clinker production rates previously estimated. 

(2) The owner or operator must determine, record, and 

maintain a record of the accuracy of the system of measuring 

hourly clinker production (or feed mass flow if applicable)

before initial use (for new sources) or within 30 days of the 

effective date of this rule (for existing sources). During each 

quarter of source operation, the owner or operator must

determine, record, and maintain a record of the ongoing accuracy 

of the system of measuring hourly clinker production (or feed 

mass flow). 

(3) The owner or operator must record the daily clinker 

production rates and kiln feed rates.

(4) The owner or operator must develop an emissions 

monitoring plan in accordance with paragraphs (o)(1) through 

(o)(4) of this section.

(e) Reserved

(f) Opacity Monitoring Requirements. The owner or operator 

of an affected source subject to a limitation on opacity under 

§63.1346 or §63.1348 must conduct required emissions monitoring 

in accordance with the provisions of paragraphs (f)(1)(i) 

through (f)(1)(vii) of this section and in accordance with the 

operation and maintenance plan developed in accordance with 
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§63.1347. The owner of operator of an affected source subject 

to a limitation on opacity under §63.1347 must conduct emissions 

monitoring in accordance with paragraphs (f)(2)(i) through 

(f)(2)(iii) of this section and in accordance with the operation 

and maintenance plan developed in accordance with (p)(1) through 

(p)(4) of this section. The owner or operator must also develop 

an opacity emissions monitoring plan in accordance with

paragraphs (o)(1) through (o)(4) and paragraph (o)(5), if 

applicable, of this section.

(1)(i) The owner or operator must conduct a monthly 10-

minute visible emissions test of each affected source in 

accordance with Method 22 of appendix A–7 to part 60 of this 

chapter. The performance test must be conducted while the 

affected source is in operation.

(ii) If no visible emissions are observed in six 

consecutive monthly tests for any affected source, the owner or 

operator may decrease the frequency of performance testing from 

monthly to semi-annually for that affected source. If visible 

emissions are observed during any semi-annual test, the owner or 

operator must resume performance testing of that affected source 

on a monthly basis and maintain that schedule until no visible 

emissions are observed in six consecutive monthly tests.

(iii) If no visible emissions are observed during the semiannual test for any affected source, the owner or operator may 
Page 424 of 456

decrease the frequency of performance testing from semi-annually 

to annually for that affected source. If visible emissions are 

observed during any annual performance test, the owner or 

operator must resume performance testing of that affected source 

on a monthly basis and maintain that schedule until no visible

emissions are observed in six consecutive monthly tests.

(iv) If visible emissions are observed during any Method 

22 performance test, of appendix A–7 to part 60 of this chapter, 

the owner or operator must conduct five 6-minute averages of 

opacity in accordance with Method 9 of appendix A–4 to part 60 

of this chapter. The Method 9 performance test, of appendix A–4 

to part 60 of this chapter, must begin within 1 hour of any 

observation of visible emissions.

(v) The requirement to conduct Method 22 visible emissions 

monitoring under this paragraph must not apply to any totally 

enclosed conveying system transfer point, regardless of the 

location of the transfer point. ―Totally enclosed conveying 

system transfer point‖ must mean a conveying system transfer 

point that is enclosed on all sides, top, and bottom. The 

enclosures for these transfer points must be operated and 

maintained as total enclosures on a continuing basis in 

accordance with the facility operations and maintenance plan.

(vi) If any partially enclosed or unenclosed conveying 

system transfer point is located in a building, the owner or 
Page 425 of 456

operator of the Portland cement plant must have the option to 

conduct a Method 22 performance test, of appendix A–7 to part 60 

of this chapter, according to the requirements of paragraphs 

(f)(1)(i) through (f)(1)(iv) of this section for each such 

conveying system transfer point located within the building, or 

for the building itself, according to paragraph (f)(1)(vii) of 

this section.

(vii) If visible emissions from a building are monitored, 

the requirements of paragraphs (f)(1)(i) through (f)(1)(iv) of 

this section apply to the monitoring of the building, and the 

owner or operator of the Portland cement plant must also test 

visible emissions from each side, roof, and vent of the building 

for at least 10 minutes. 

(2)(i) The owner or operator of a raw mill or finish mill 

must monitor opacity by conducting daily visual emissions 

observations of the mill sweep and air separator particulate 

matter control devices (PMCD) of these affected sources in 

accordance with the procedures of Method 22 of appendix A-7 to 

part 60 of this chapter. The duration of the Method 22 

performance test must be 6 minutes. 

(ii) Within 24 hours of the end of the Method 22 

performance test in which visible emissions were observed, the 

owner or operator must conduct a follow up Method 22 performance 
Page 426 of 456

test of each stack from which visible emissions were observed 

during the previous Method 22 performance test. 

(iii) If visible emissions are observed during the followup 

Method 22 performance test required by paragraph (a)(5)(ii) of 

this section from any stack from which visible emissions were 

observed during the previous Method 22 performance test required 

by paragraph (a)(5)(i) of the section, the owner or operator 

must conduct a visual opacity test of each stack from which 

emissions were observed during the follow up Method 22 

performance test in accordance with Method 9 of appendix A-4 to 

part 60 of this chapter. The duration of the Method 9 test must

be 30 minutes.

(3) Corrective Actions. If visible emissions are observed 

during any Method 22 visible emissions test conducted under 

paragraphs (f)(1) or (f)(2) of this section, the owner or 

operator must initiate, within one-hour, the corrective actions 

specified in the site specific operating and maintenance plan

provisions in §63.1347.

(4) The requirements under paragraph (f)(2) of this section 

to conduct daily Method 22 testing must not apply to any 

specific raw mill or finish mill equipped with a continuous 

opacity monitoring system (COMS) or bag leak detection system 

(BLDS). 
Page 427 of 456

(i) If the owner or operator chooses to install a COMS in 

lieu of conducting the daily visual emissions testing required 

under paragraph (f)(2) of this section, then the COMS must be 

installed at the outlet of the PM control device of the raw mill 

or finish mill and the COMS must be installed, maintained, 

calibrated, and operated as required by the general provisions 

in subpart A of this part and according to PS–1 of appendix B to 

part 60 of this chapter.

(ii) If the owner or operator chooses to install a BLDS in 

lieu of conducting the daily visual emissions testing required 

under paragraph (f)(2) of this section, the requirements in 

paragraphs (m)(1) through (m)(4), (m)(10) and (m)(11) of this 

section apply. 

(g) D/F Monitoring Requirements. The owner or operator of 

an affected source subject to an emissions limitation on D/F 

emissions must comply with the monitoring requirements of 

paragraphs (g)(1) through (g)(6) and paragraphs (m)(1) through 

(m)(4) of this section to demonstrate continuous compliance with 

the D/F emissions standard. The owner or operator must also 

develop an emissions monitoring plan in accordance with 

paragraphs (p)(1) through (p)(4) of this section. 

(1) The owner or operator must install, calibrate, 

maintain, and continuously operate a continuous monitor to 

record the temperature of the exhaust gases from the kiln, in-
Page 428 of 456

line kiln/raw mill, and alkali bypass, if applicable, at the 

inlet to, or upstream of, the kiln, in-line kiln/raw mill and/or 

alkali bypass PMCDs.

(i) The temperature recorder response range must include 

zero and 1.5 times the average temperature established according 

to the requirements in §63.1349(b)(3)(iv).

(ii) The calibration reference for the temperature 

measurement must be a National Institute of Standards and 

Technology calibrated reference thermocouple-potentiometer 

system or alternate reference, subject to approval by the 

Administrator.

(iii) The calibration of all thermocouples and other 

temperature sensors must be verified at least once every three 

months.

(2) The owner or operator must monitor and continuously 

record the temperature of the exhaust gases from the kiln, inline kiln/raw mill, and alkali bypass, if applicable, at the 

inlet to the kiln, in-line kiln/raw mill and/or alkali bypass 

PMCD.

(3) The required minimum data collection frequency must be 

one minute.

(4) Each hour, calculate the three-hour average temperature 

for the previous 3 hours of process operation using all of the 

one-minute data available (i.e., the CMS is not out-of-control.)
Page 429 of 456

(5) When the operating status of the raw mill of the inline kiln/raw mill is changed from off to on or from on to off, 

the calculation of the three-hour rolling average temperature 

must begin anew, without considering previous recordings.

(h) Monitoring Requirements for Sources Using Sorbent

Injection. The owner or operator of an affected source subject 

to an operating limit on D/F emissions that employs carbon 

injection as an emission control technique must comply with the 

additional monitoring requirements of paragraphs (h)(1) and

(h)(2) and paragraphs (m)(1) through (m)(4) and (m)(9) of this 

section. The owner or operator must also develop an emissions 

monitoring plan in accordance with paragraphs (p)(1) through 

(p)(4) of this section.

(1) Install, operate, calibrate, and maintain a continuous 

monitor to record the rate of activated carbon injection. The 

accuracy of the rate measurement device must be ±1 percent of 

the rate being measured.

(i) Verify the calibration of the device at least once 

every three months.

(ii) Each hour, calculate the three-hour rolling average 

activated carbon injection rate for the previous 3 hours of 

process operation using all of the one-minute data available 

(i.e., the CMS is not out-of-control.)
Page 430 of 456

(iii) When the operating status of the raw mill of the inline kiln/raw mill is changed from off to on or from on to off, 

the calculation of the three-hour rolling average activated 

carbon injection rate must begin anew, without considering 

previous recordings.

(2)(i) Install, operate, calibrate, and maintain a 

continuous monitor to record the activated carbon injection 

system carrier gas parameter (either the carrier gas flow rate 

or the carrier gas pressure drop) established during the D/F 

performance test in accordance with §63.1349(b)(3).

(ii) Each hour, calculate the three-hour rolling average 

of the selected parameter value for the previous 3 hours of 

process operation using all of the one-minute data available 

(i.e., the CMS is not out-of-control.)

(i) THC Monitoring Requirements. The owner or operator of 

an affected source subject to an emissions limitation on THC 

emissions must comply with the monitoring requirements of 

paragraphs (i)(1) and (i)(2) and (m)(1) through (m)(4) of this 

section. The owner or operator must also develop an emissions 

monitoring plan in accordance with paragraphs (p)(1) through 

(p)(4) of this section.

(1) The owner or operator must install, operate, and 

maintain a THC continuous emission monitoring system in 

accordance with Performance Specification 8 of appendix B to 
Page 431 of 456

part 60 of this chapter and comply with all of the requirements 

for continuous monitoring systems found in the general 

provisions, subpart A of this part. The owner or operator must

operate and maintain each CEMS according to the quality 

assurance requirements in Procedure 1 of appendix F in part 60 

of this chapter.

(2) For sources equipped with an alkali bypass stack, 

instead of installing a CEMS, the source may use the results of 

the initial or subsequent performance test to demonstrate 

compliance with the THC emission limit.

(j) Total Organic HAP Monitoring Requirements. The owner 

or operator of an affected source complying with the total 

organic HAP emissions limits shall continuously monitor THC 

according to paragraph (i)(1) and (2) or in accordance with 

Performance Specification 15 of appendix B to part 60 of this 

chapter and comply with all of the requirements for continuous 

monitoring systems found in the general provisions, subpart A of 

this part. The owner or operator shall operate and maintain 

each CEMS according to the quality assurance requirements in 

Procedure 1 of appendix F in part 60 of this chapter. In 

addition, the owner and operator must and (m)(1) through (m)(4)

of this section. The owner or operator must also develop an 

emissions monitoring plan in accordance with paragraphs (p)(1) 

through (p)(4) of this section.
Page 432 of 456

(k) Mercury Monitoring Requirements. The owner or 

operator of a kiln or in-line kiln/raw mill subject to an 

emissions limitation on mercury emissions must install and 

operate a mercury continuous emissions monitoring system (Hg 

CEMS) in accordance with Performance Specification 12A of 

appendix B to part 60 of this chapter or a sorbent trap-based 

integrated monitoring system in accordance with Performance 

Specification 12B of appendix B to part 60 of this chapter. The 

owner or operator must continuously monitor mercury according to 

paragraphs (k)(1) through (k)(3) and (m)(1) through (m)(4) of 

this section. The owner or operator must also develop an 

emissions monitoring plan in accordance with paragraphs (p)(1) 

through (p)(4) of this section.

(1) The span value for any Hg CEMS must include the 

intended upper limit of the mercury concentration measurement 

range during normal ―mill on‖ operation which may be exceeded 

during ―mill off‖ operation or other short term conditions 

lasting less than 24 consecutive kiln operating hours. However, 

the span should be at least equivalent to approximately two 

times the emissions standard and it may be rounded to the 

nearest multiple of 10 μg/m3 of total mercury.

(2) The owner or operator must operate and maintain each Hg 

CEMS or sorbent trap-based integrated monitoring system 
Page 433 of 456

according to the quality assurance requirements in Procedure 5 

of appendix F to part 60 of this chapter. 

(3) Relative accuracy testing of mercury monitoring systems 

under Performance Specification 12A, Performance Specification 

12B, or Procedure 5 must be at normal operating conditions with 

the raw mill on.

(4) Owners or operators using a mercury CEMS must install, 

operate, calibrate, and maintain an instrument for continuously 

measuring and recording the exhaust gas flow rate to the 

atmosphere according to the requirements in paragraphs (n)(1)

through (n)(10) of this section.

(l) HCl Monitoring Requirements. The owner or operator of 

an affected source subject to an emissions limitation on HCl 

emissions in §63.1343 must continuously monitor HCl according to 

paragraph (l)(1) and (2) and paragraphs (m)(1) through (m)(4) 

of this section. The owner or operator must also develop an 

emissions monitoring plan in accordance with paragraphs (p)(1) 

through (p)(4) of this section.

(1)(i) Continuously monitor compliance with the HCl limit 

by operating a continuous emission monitor in accordance with 

Performance Specification 15 of appendix B to part 60 of this 

chapter. The owner or operator must operate and maintain each 

CEMS according to the quality assurance requirements in 

Procedure 1 of 40 CFR of appendix F to part 60 of this chapter 
Page 434 of 456

except that the Relative Accuracy Test Audit requirements of 

Procedure 1 must be replaced with the validation requirements 

and criteria of sections 11.1.1 and 12.0 of Performance 

Specification 15, or 

(2) Install, operate, and maintain a CMS to monitor wet 

scrubber parameters as specified in paragraphs (m)(5) and (m)(7) 

of this section. 

(m) Parameter Monitoring Requirements. If you have an 

operating limit that requires the use of a CMS, you must 

install, operate, and maintain each continuous parameter 

monitoring system (CPMS) according to the procedures in 

paragraphs (n)(1) through (4) of this section by the compliance 

date specified in §63.1351. You must also meet the applicable 

specific parameter monitoring requirements in paragraphs (m)(5) 

through (m)(11) that are applicable to you.

(1) The CMS must complete a minimum of one cycle of 

operation for each successive 15-minute period. You must have a 

minimum of four successive cycles of operation to have a valid 

hour of data.

(2) The owner or operator must conduct all monitoring in 

continuous operation at all times that the unit is operating. 

(3) Determine the 3-hour block average of all recorded 

readings.
Page 435 of 456

(4) Record the results of each inspection, calibration, and 

validation check.

(5) Liquid Flow Rate Monitoring Requirements. If you have 

an operating limit that requires the use of a flow measurement 

device, you must meet the requirements in paragraphs (m)(5)(i) 

through (iv) of this section.

(i) Locate the flow sensor and other necessary equipment in 

a position that provides a representative flow.

(ii) Use a flow sensor with a measurement sensitivity of 2 

percent of the flow rate.

(iii) Reduce swirling flow or abnormal velocity 

distributions due to upstream and downstream disturbances.

(iv) Conduct a flow sensor calibration check at least 

semiannually.

(6) Specific Pressure Monitoring Requirements. If you have 

an operating limit that requires the use of a pressure 

measurement device, you must meet the requirements in paragraphs 

(m)(6)(i) through (vi) of this section.

(i) Locate the pressure sensor(s) in a position that 

provides a representative measurement of the pressure.

(ii) Minimize or eliminate pulsating pressure, vibration, 

and internal and external corrosion.
Page 436 of 456

(iii) Use a gauge with a minimum tolerance of 1.27 

centimeters of water or a transducer with a minimum tolerance of 

1 percent of the pressure range.

(iv) Check pressure tap pluggage daily.

(v) Using a manometer, check gauge calibration quarterly 

and transducer calibration monthly.

(vi) Conduct calibration checks any time the sensor exceeds 

the manufacturer's specified maximum operating pressure range or 

install a new pressure sensor.

(7) Specific pH Monitoring Requirements. If you have an 

operating limit that requires the use of a pH measurement 

device, you must meet the requirements in paragraphs (m)(7)(i) 

through (iii) of this section.

(i) Locate the pH sensor in a position that provides a 

representative measurement of scrubber effluent pH.

(ii) Ensure the sample is properly mixed and representative 

of the fluid to be measured.

(iii) Check the pH meter's calibration on at least two 

points every 8 hours of process operation.

(8) Reserved.

(9) Mass Flow Rate (for Sorbent Injection) Monitoring 

Requirements. If you have an operating limit that requires the 

use of equipment to monitor sorbent injection rate (e.g., weigh 

belt, weigh hopper, or hopper flow measurement device), you must 
Page 437 of 456

meet the requirements in paragraphs (m)(9)(i) through (iii) of 

this section.

(i) Locate the device in a position(s) that provides a 

representative measurement of the total sorbent injection rate.

(ii) Install and calibrate the device in accordance with 

manufacturer's procedures and specifications.

(iii) At least annually, calibrate the device in accordance 

with the manufacturer's procedures and specifications.

(10) Bag leak detection monitoring requirements. If you 

elect to use a fabric filter bag leak detection system to comply 

with the requirements of this subpart, you must install, 

calibrate, maintain, and continuously operate a bag leak 

detection system as specified in paragraphs (m)(10)(i) through 

(viii) of this section.

(i) You must install and operate a bag leak detection 

system for each exhaust stack of the fabric filter.

(ii) Each bag leak detection system must be installed, 

operated, calibrated, and maintained in a manner consistent with 

the manufacturer's written specifications and recommendations 

and in accordance with the guidance provided in EPA–454/R–98–

015, September 1997.

(iii) The bag leak detection system must be certified by 

the manufacturer to be capable of detecting particulate matter 
Page 438 of 456

emissions at concentrations of 10 or fewer milligrams per actual 

cubic meter.

(iv) The bag leak detection system sensor must provide 

output of relative or absolute particulate matter loadings.

(v) The bag leak detection system must be equipped with a 

device to continuously record the output signal from the sensor.

(vi) The bag leak detection system must be equipped with an 

alarm system that will alert an operator automatically when an 

increase in relative particulate matter emissions over a preset 

level is detected. The alarm must be located such that the alert 

is detected and recognized easily by an operator.

(vii) For positive pressure fabric filter systems that do 

not duct all compartments of cells to a common stack, a bag leak 

detection system must be installed in each baghouse compartment 

or cell.

(viii) Where multiple bag leak detectors are required, the 

system's instrumentation and alarm may be shared among 

detectors.

(11) For each BLDS, the owner or operator must initiate 

procedures to determine the cause of every alarm within 8 hours 

of the alarm. The owner or operator must alleviate the cause of 

the alarm within 24 hours of the alarm by taking whatever 

corrective action(s) are necessary. Corrective actions may 

include, but are not limited to the following:
Page 439 of 456

(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. 

(n) Continuous Emissions Rate Monitoring System. The owner 

or operator must install, operate, calibrate, and maintain 

instruments, according to the requirements in paragraphs (n)(1) 

and (2) of this section, for continuously measuring and 

recording the pollutant per mass flow rate to the atmosphere 

from sources subject to an emissions limitation that has a 

pounds per ton of clinker unit.

(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 mercury or PM CEMS, taking into account 

the manufacturer‘s recommendations. The flow rate sensor is 

that portion of the system that senses the volumetric flow rate 

and generates an output proportional to that flow rate.
Page 440 of 456

(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 

recording values over the entire range specified in paragraph 

(n)(1) 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.

(7) The flow rate sensor must have provisions to determine 

the daily zero and upscale calibration drift (CD) (see sections 

3.1 and 8.3 of Performance Specification 2 in appendix B to Part 

60 of this chapter for a discussion of CD).
Page 441 of 456

(i) Conduct the CD tests at two reference signal levels, 

zero (e.g., 0 – 20 percent of span) and upscale (e.g., 50 to 70 

percent of span).

(ii) The absolute value of the difference between the flow 

monitor response and the reference signal must be equal to or 

less than 3 percent of the flow monitor span.

(8) You must perform an initial relative accuracy test of 

the flow rate monitoring system according to Section 8.2 of 

Performance Specification 6 of appendix B to Part 60 of the 

chapter with the exceptions in paragraphs (n)(8)(i) and 

(n)(8)(ii).

(i) The relative accuracy test is to evaluate the flow rate 

monitoring system along rather than a continuous emission rate 

monitoring system.

(ii) The relative accuracy of the flow rate monitoring 

system shall be no greater than 10 percent of the mean value of 

the reference method data.

(9) You must verify the accuracy of the flow rate 

monitoring system at least once per year by repeating the 

relative accuracy test specified in paragraph (n)(8).

(10) 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, 

shutdown, and malfunction, except for periods of monitoring 
Page 442 of 456

system malfunctions, repairs associated with monitoring system 

malfunctions, and required monitoring system quality assurance 

or quality control activities (including, as applicable, 

calibration checks and required zero and span adjustments.

(o) Alternate Monitoring Requirements Approval. An owner 

or operator may submit an application to the Administrator for 

approval of alternate monitoring requirements to demonstrate 

compliance with the emission standards of this subpart, except 

for emission standards for THC, subject to the provisions of 

paragraphs (n)(1) through (n)(6) of this section.

(1) The Administrator will not approve averaging periods 

other than those specified in this section, unless the owner or 

operator documents, using data or information, that the longer 

averaging period will ensure that emissions do not exceed levels 

achieved during the performance test over any increment of time 

equivalent to the time required to conduct three runs of the 

performance test.

(2) If the application to use an alternate monitoring 

requirement is approved, the owner or operator must continue to 

use the original monitoring requirement until approval is 

received to use another monitoring requirement.

(3) The owner or operator must submit the application for 

approval of alternate monitoring requirements no later than the 

notification of performance test. The application must contain 
Page 443 of 456

the information specified in paragraphs (m)(3)(i) through (iii) 

of this section:

(i) Data or information justifying the request, such as the 

technical or economic infeasibility, or the impracticality of 

using the required approach;

(ii) A description of the proposed alternative monitoring 

requirement, including the operating parameter to be monitored, 

the monitoring approach and technique, the averaging period for 

the limit, and how the limit is to be calculated; and

(iii) Data or information documenting that the alternative 

monitoring requirement would provide equivalent or better 

assurance of compliance with the relevant emission standard.

(4) The Administrator will notify the owner or operator of 

the approval or denial of the application within 90 calendar 

days after receipt of the original request, or within 60 

calendar days of the receipt of any supplementary information, 

whichever is later. The Administrator will not approve an 

alternate monitoring application unless it would provide 

equivalent or better assurance of compliance with the relevant 

emission standard. Before disapproving any alternate monitoring 

application, the Administrator will provide:

(i) Notice of the information and findings upon which the 

intended disapproval is based; and
Page 444 of 456

(ii) Notice of opportunity for the owner or operator to 

present additional supporting information before final action is 

taken on the application. This notice will specify how much 

additional time is allowed for the owner or operator to provide 

additional supporting information.

(5) The owner or operator is responsible for submitting any 

supporting information in a timely manner to enable the 

Administrator to consider the application prior to the 

performance test. Neither submittal of an application, nor the 

Administrator's failure to approve or disapprove the application 

relieves the owner or operator of the responsibility to comply 

with any provision of this subpart.

(6) The Administrator may decide at any time, on a case-bycase basis that additional or alternative operating limits, or 

alternative approaches to establishing operating limits, are 

necessary to demonstrate compliance with the emission standards 

of this subpart.

(p) Development and Submittal (Upon Request) of Monitoring 

Plans. If you demonstrate compliance with any applicable 

emission limit through performance stack testing or other 

emissions monitoring, you must develop a site-specific 

monitoring plan according to the requirements in paragraphs 

(p)(1) through (4) of this section. This requirement also 

applies to you if you petition the EPA Administrator for 
Page 445 of 456

alternative monitoring parameters under paragraph (n) of this 

section and §63.8(f). If you use a BLDS, you must also meet the 

requirements specified in paragraph (o)(5) of this section.

(1) For each continuous monitoring system (CMS) required in 

this section, you must develop, and submit to the permitting 

authority for approval upon request, a site-specific monitoring 

plan that addresses paragraphs (o)(1)(i) through (iii) of this 

section. You must submit this site-specific monitoring plan, if 

requested, at least 60 days before your initial performance 

evaluation of your CMS.

(i) Installation of the CMS sampling probe or other 

interface at a measurement location relative to each affected 

process unit such that the measurement is representative of 

control of the exhaust emissions (e.g., on or downstream of the 

last control device);

(ii) Performance and equipment specifications for the 

sample interface, the pollutant concentration or parametric 

signal analyzer, and the data collection and reduction systems; 

and

(iii) Performance evaluation procedures and acceptance 

criteria (e.g., calibrations).

(2) In your site-specific monitoring plan, you must also 

address paragraphs (o)(2)(i) through (iii) of this section.
Page 446 of 456

(i) Ongoing operation and maintenance procedures in 

accordance with the general requirements of §63.8(c)(1), (c)(3), 

and (c)(4)(ii);

(ii) Ongoing data quality assurance procedures in 

accordance with the general requirements of §63.8(d); and

(iii) Ongoing recordkeeping and reporting procedures in 

accordance with the general requirements of §63.10(c), (e)(1), 

and (e)(2)(i).

(3) You must conduct a performance evaluation of each CMS 

in accordance with your site-specific monitoring plan.

(4) You must operate and maintain the CMS in continuous 

operation according to the site-specific monitoring plan.

(5) BLDS Monitoring Plan. Each monitoring plan must 

describe the items in paragraphs (o)(5)(i) through (v) of this 

section. At a minimum the owner or operator must retain records 

related to the site-specific monitoring plan and information 

discussed in paragraphs (m)(1) through (4), (m)(10) and (m)(11) 

of this section for a period of 5 years, with at least the first 

2 years on-site;

(i) Installation of the BLDS;

(ii) Initial and periodic adjustment of the BLDS, including 

how the alarm set-point will be established;
Page 447 of 456

(iii) Operation of the BLDS, including quality assurance 

procedures;

(iv) How the BLDS will be maintained, including a routine 

maintenance schedule and spare parts inventory list;

(v) How the BLDS output will be recorded and stored.

21. Section 63.1351 is amended to read as follows:

§63.1351 Compliance dates.

(a) Except as noted in paragraph (b) below, the compliance 

date for an owner or operator of an existing affected source 

subject to the provisions of this subpart is June 14, 2002.

(b) The compliance date for existing sources with the PM, 

mercury, THC, and HCl emissions limits in §63.1343(b) which 

became effective in [INSERT DATE 60 DAYS AFTER OF PUBLICATION OF 

THESE AMENDMENTS IN THE FERERAL REGISTER] will be [INSERT DATE 

THREE YEARS FROM THE DATE OF PUBLICATION OF THESE AMENDMENTS IN 

THE FEDERAL REGISTER]. 

(c) Except as noted in paragraph (d) below, the compliance 

date for an owner or operator of an affected source subject to 

the provisions of this subpart that commences new construction 

or reconstruction after March 24, 1998, is June 14, 1999, or 

upon startup of operations, whichever is later.

(d) The compliance date for new sources with the PM, 

mercury, THC, and HCl emissions limits in §63.1343(b) will be 
Page 448 of 456

[INSERT DATE 60 DAYS AFTER PUBLICATION OF THESE AMENDMENTS IN 

THE FERERAL REGISTER] or startup, whichever is later.

22. Section 63.1352 is amended to read:

§ 63.1352 Additional test methods.

(a) If you are conducting tests to determine the rates of 

emission of hydrogen chloride (HCl) from kilns and associated 

bypass stacks at Portland cement manufacturing facilities, for 

use in applicability determinations under §63.1340 you may use 

Method 320 or Method 321 of appendix A of this part.

(b) Owners or operators conducting tests to determine the 

rates of emission of specific organic HAP from raw material 

dryers, kilns and in-line kiln/raw mills at Portland cement 

manufacturing facilities, solely for use in applicability 

determinations under §63.1340 of this subpart are permitted to 

use Method 320 of appendix A to this part, or Method 18 of 

appendix A to part 60 of this chapter.

23. Section 63.1354 is amended by adding paragraph 

(b)(9)(vi) to read as follows:

§63.1354 Reporting requirements.

* * * * *

(b )(9) * * *

(vi) Monthly rolling average mercury, THC, PM, and HCl (if 

applicable) emissions levels in the units of the applicable 
Page 449 of 456

emissions limit for each kiln, clinker cooler, and raw material 

dryer. 

* * * * *

(g)(i) The occurrence and duration of each startup or 

shutdown

(h)(1) Records of the occurrence and duration of each 

malfunction of operation (i.e., process equipment) or the air 

pollution control and monitoring equipment.

(2) Records of actions taken during periods of malfunction 

to minimize emissions in accordance with 63.1348(d) including 

corrective actions to restore malfunctioning process and air 

pollution control and monitoring equipment to its normal or 

usual manner of operation.

* * * * *

24. Section 63.1355 is amended by revising paragraph (e) 

to read as follows:

§63.1355 Recordkeeping requirements.

* * * * *

(e) You must keep records of the daily clinker production 

rates and kiln feed rates for area sources. 

* * * * *

25. Section 63.1356 is revised to read as follows: 

§63.1356 Sources with multiple emission limits or monitoring 

requirements. 
Page 450 of 456

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. 

26. Table 2 to Subpart LLL of Part 63 is revised to read 

as follows:

Table 2 to Subpart LLL of Part 63—Applicability of General 

Provisions

Citation Requirement

Applies 

to 

Subpart 

LLL Explanation

63.1(a)(1)–(4) Applicability Yes

63.1(a)(5) No [Reserved]

63.1(a)(6)–(8) Applicability Yes

63.1(a)(9) No [Reserved]

63.1(a)(10)–

(14)

Applicability Yes

63.1(b)(1) Initial Applicability 

Determination

No §63.1340 

specifies

applicability.

63.1(b)(2)–(3) Initial Applicability 

Determination

Yes

63.1(c)(1) Applicability After 

Standard Established

Yes

63.1(c)(2) Permit Requirements Yes Area sources 

must obtain 

Title V 

permits.

63.1(c)(3) No [Reserved]
Page 451 of 456

63.1(c)(4)–(5) Extensions, Notifications Yes

63.1(d) No [Reserved]

63.1(e) Applicability of Permit 

Program

Yes

63.2 Definitions Yes Additional 

definitions in 

§63.1341.

63.3(a)–(c) Units and Abbreviations Yes

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

63.4(a)(4) No [Reserved]

63.4(a)(5) Compliance date Yes

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

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

63.5(b)(1) Compliance Dates Yes

63.5(b)(2) No [Reserved]

63.5(b)(3)–(6) Construction Approval, 

Applicability

Yes

63.5(c) No [Reserved]

63.5(d)(1)–(4) Approval of 

Construction/Reconstruction

Yes

63.5(e) Approval of 

Construction/Reconstruction

Yes

63.5(f)(1)–(2) Approval of 

Construction/Reconstruction

Yes

63.6(a) Compliance for Standards 

and Maintenance

Yes

63.6(b)(1)–(5) Compliance Dates Yes

63.6(b)(6) No [Reserved]

63.6(b)(7) Compliance Dates Yes

63.6(c)(1)–(2) Compliance Dates Yes

63.6(c)(3)–(4) No [Reserved]

63.6(c)(5) Compliance Dates Yes

63.6(d) No [Reserved]
Page 452 of 456

63.6(e)(1)–(2) Operation & Maintenance No See 63.1348(d) 

for general 

duty 

requirement. 

Any reference 

to 

63.6(e)(1)(i) 

in other 

General 

Provisions is 

to be treated 

as a crossreference to 

63.1348(d)

63.6(e)(3) Startup, Shutdown 

Malfunction Plan

No

63.6(f)(1) Compliance with Emission 

Standards

No

63.6(f)(2)–(3) Compliance with Emission 

Standards

Yes

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

63.6(h)(1) Opacity/VE Standards No

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

63.6(h)(3) No [Reserved]

63.6(h)(4)–

(h)(5)(i)

Opacity/VE Standards Yes

63.6(h)(5)(ii)–

(iv)

Opacity/VE Standards No Test duration 

specified in 

subpart LLL.

63.6(h)(6) Opacity/VE Standards Yes

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

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

63.6(i)(15) No [Reserved]

63.6(i)(16) Extension of Compliance Yes

63.6(j) Exemption from Compliance Yes

63.7(a)(1)–(3) Performance Testing 

Requirements

Yes §63.1349 has 

specific 

requirements.
Page 453 of 456

63.7(b) Notification Yes

63.7(c) Quality Assurance/Test Plan Yes

63.7(d) Testing Facilities Yes

63.7(e)(1)–(4) Conduct of Tests No

63.7(f) Alternative Test Method Yes

63.7(g) Data Analysis Yes

63.7(h) Waiver of Tests Yes

63.8(a)(1) Monitoring Requirements Yes

63.8(a)(2) Monitoring No §63.1350 

includes CEMS 

requirements.

63.8(a)(3) No [Reserved]

63.8(a)(4) Monitoring No Flares not 

applicable.

63.8(b)(1)–(3) Conduct of Monitoring Yes

63.8(c)(1)–(8) CMS Operation/Maintenance Yes Temperature 

and activated 

carbon 

injection 

monitoring 

data reduction 

requirements 

given in 

subpart LLL.

63.8(d) Quality Control Yes, 

except 

for the 

reference 

to the 

SSM Plan 

in the 

last 

sentence.

63.8(e) Performance Evaluation for 

CMS

Yes

63.8(f)(1)–(5) Alternative Monitoring 

Method

Yes Additional 

requirements 

in 
Page 454 of 456

§63.1350(l).

63.8(f)(6) Alternative to RATA Test Yes

63.8(g) Data Reduction Yes

63.9(a) Notification Requirements Yes

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

63.9(c) Request for Compliance 

Extension

Yes

63.9(d) New Source Notification for 

Special Compliance 

Requirements

Yes

63.9(e) Notification of Performance 

Test

Yes

63.9(f) Notification of VE/Opacity 

Test

Yes Notification 

not required 

for VE/opacity 

test under 

§63.1350(e) 

and (j).

63.9(g) Additional CMS 

Notifications

Yes

63.9(h)(1)–(3) Notification of Compliance 

Status

Yes

63.9(h)(4) No [Reserved]

63.9(h)(5)–(6) Notification of Compliance 

Status

Yes

63.9(i) Adjustment of Deadlines Yes

63.9(j) Change in Previous 

Information

Yes

63.10(a) Recordkeeping/Reporting Yes

63.10(b) General Requirements Yes

63.10(c)(1) Additional CMS 

Recordkeeping

Yes PS–8A 

supersedes 

requirements 

for THC CEMS.

63.10(c)(2)–(4) No [Reserved]

63.10(c)(5)–(8)Additional CMS Yes PS–8A 
Page 455 of 456

Recordkeeping supersedes 

requirements 

for THC CEMS.

63.10(c)(9) No [Reserved]

63.10(c)(10)–

(15)

Additional CMS 

Recordkeeping

Yes PS–8A 

supersedes 

requirements 

for THC CEMS.

63.10(d)(1) General Reporting 

Requirements

Yes

63.10(d)(2) Performance Test Results Yes

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

63.10(d)(4) Progress Reports Yes

63.10(d)(5) Startup, Shutdown, 

Malfunction Reports

Yes

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

63.10(e)(3) Excess Emissions and CMS 

Performance Reports

Yes Exceedances 

are defined in 

subpart LLL.

63.10(f) Waiver for 

Recordkeeping/Reporting

Yes

63.11(a)–(b) Control Device Requirements No Flares not 

applicable.

63.12(a)–(c) State Authority and 

Delegations

Yes

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

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

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

Appendix to Part 63 – [AMENDED]

27. Section 1.3.2 of Method 321 of Appendix A to Part 63 

– Test Methods is revised to read as follows:

Appendix A to Part 63 – Test Methods
Page 456 of 456

* * * * * 

Test Method 321 – Measurement of Gaseous Hydrogen Chloride 

Emissions At Portland Cement Kilns by Fourier Transform 

Infrared (FTIR) Spectroscopy

* * * * *

1.3.2 The practical lower quantification range is usually 

higher than that indicated by the instrument performance in the 

laboratory, and is dependent upon (1) the presence of 

interfering species in the exhaust gas (notably H2O), (2) the 

optical alignment of the gas cell and transfer optics, and (3) 

the quality of the reflective surfaces in the cell (cell 

throughput). Under typical test conditions (moisture content of 

up to 30 percent, 10 meter absorption path length, liquid 

nitrogen-cooled IR detector, 0.5 cm-1 resolution, and an 

interferometer sampling time of 60 seconds) a typical lower 

quantification range for HCl is 0.1 to 1.0 ppm.

* * * * *