E.O. 12866 Review 2060-AQ42 Email 013111 +1 att.txt

 

 

 From: Sharon Nizich/RTP/USEPA/US 

 To: cortney_higgins@omb.eop.gov 

 Cc: Fred Talcott/DC/USEPA/US@EPA, Dave Guinnup/RTP/USEPA/US@EPA, 

Steve Fruh/RTP/USEPA/US@EPA, Jan Tierney/DC/USEPA/US@EPA, 

 Michael Stewart/RTP/USEPA/US@EPA 

 

 

 Date: 01/31/2011 10:44 AM 

 Subject: Part of E.O. 12866 Review: EPA Staff Response to revisions 

pertaining to Primary Lead RTR: RIN 2060-AQ42 

 

Hello CortneyPlease find edits per your last comments as well as a few from Region 7:

1. Page 58 - we clarified the language you requested 2. Page 93 - We 

clarified the location of the potential new smelter, per Region 7 late Friday.

3. Page 101 footnote 3 - we added clarification per a Region 7 comment 

received late Friday.

4. Page 110 - We omitted the 2 sentences per a Region 7 comment received late 

Friday. We can discuss.

THANKS.

(See attached file: E O 12866 Primary Lead Smelting 2060-AQ42 Proposal 

012811_EO12866interagencycomments deg.docx)

Sharon V. Nizich

Metals and Minerals Group

Sector Policies and Programs Division

OAQPS - US EPA

RTP NC 27711

919/541-2825

Page 1
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E.O. 12866 Primary Lead Smelting 2060-AQ42 Proposal 

 6560-50-P 

ENVIRONMENTAL PROTECTION AGENCY 

40 CFR Part 63 

[EPA-HQ-OAR-2004-0305; FRL- ] 

RIN 2060–AQ42 

National Emission Standards for Hazardous Air Pollutants: 

Primary Lead Smelting 

AGENCY: Environmental Protection Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: EPA is proposing amendments to the national emission 

standards for hazardous air pollutants (NESHAP) for Primary Lead 

Smelting to address the results of the residual risk and 

technology reviews conducted as required under sections 

112(d)(6) and (f)(2) of the Clean Air Act (CAA). These proposed 

amendments include revisions to the emission limits for lead, 

the addition of a lead concentration in air standard, and the 

modification and addition of testing and monitoring and related 

notification, recordkeeping, and reporting requirements. We are 

also proposing to revise provisions addressing periods of 

startup, shutdown, and malfunction to ensure that they are 

consistent with a recent court decision. Finally, we are 

proposing revisions to the rule’s applicability provision to 

make it consistent with the definition of the source category 
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and proposing other minor technical changes to the standard. We 

are also responding to a petition for rulemaking filed on the 

standard with regard to lead as a surrogate and regulation of 

volatile organic compounds (VOC) and acid gases. 

DATES: Comments must be received on or before [INSERT DATE 45 

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

the Paperwork Reduction Act, comments on the information 

collection provisions are best assured of having full effect if 

the Office of Management and Budget (OMB) receives a copy of 

your comments on or before [INSERT DATE 30 DAYS FROM DATE OF 

PUBLICATION IN THE FEDERAL REGISTER].

Public Hearing. If anyone contacts EPA requesting to speak 

at a public hearing by [INSERT DATE 10 DAYS FROM DATE OF 

PUBLICATION IN THE FEDERAL REGISTER], a public hearing will be 

held on [INSERT DATE 15 DAYS FROM DATE OF PUBLICATION IN THE 

FEDERAL REGISTER]. 

ADDRESSES: Submit your comments, identified by Docket ID Number 

EPA-HQ-OAR-2004-0305, by one of the following methods: 

 www.regulations.gov: Follow the on-line instructions for 

submitting comments. 

 E-mail: a-and-r-docket@epa.gov, Attention Docket ID Number 

EPA-HQ-OAR-2004-0305. 
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 Fax: (202) 566-9744, Attention Docket ID Number EPA-HQOAR-2004-0305. 

 Mail: U.S. Postal Service, send comments to: EPA Docket 

Center, EPA West (Air Docket), Attention Docket ID Number 

EPA-HQ-OAR-2004-0305, U.S. Environmental Protection Agency, 

Mailcode: 2822T, 1200 Pennsylvania Ave., NW, Washington, DC 

20460. Please include a total of two copies. In addition, 

please mail a copy of your comments on the information 

collection provisions to the Office of Information and 

Regulatory Affairs, Office of Management and Budget (OMB), 

Attn: Desk Officer for EPA, 725 17th Street, NW, Washington, 

DC 20503. 

 Hand Delivery: U.S. Environmental Protection Agency, EPA 

West (Air Docket), Room 3334, 1301 Constitution Ave., NW, 

Washington, DC 20004, Attention Docket ID Number EPA-HQOAR-2004-0305. Such deliveries are only accepted during 

the Docket’s normal hours of operation, and special 

arrangements should be made for deliveries of boxed 

information. 

Instructions. Direct your comments to Docket ID Number 

EPA-HQ-OAR-2004-0305. EPA’s policy is that all comments 

received will be included in the public docket without change 

and may be made available on-line at www.regulations.gov, 
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including any personal information provided, unless the comment 

includes information claimed to be confidential business 

information (CBI) or other information whose disclosure is 

restricted by statute. Do not submit information that you 

consider to be CBI or otherwise protected through 

www.regulations.gov or e-mail. The www.regulations.gov website 

is an “anonymous access” system, which means EPA will not know 

your identity or contact information unless you provide it in 

the body of your comment. If you send an e-mail comment 

directly to EPA without going through www.regulations.gov, your 

e-mail address will be automatically captured and included as 

part of the comment that is placed in the public docket and made 

available on the Internet. If you submit an electronic comment, 

EPA recommends that you include your name and other contact 

information in the body of your comment and with any disk or CDROM you submit. If EPA cannot read your comment due to 

technical difficulties and cannot contact you for clarification, 

EPA may not be able to consider your comment. Electronic files 

should avoid the use of special characters, any form of 

encryption, and be free of any defects or viruses. For 

additional information about EPA’s public docket, visit the EPA 

Docket Center homepage at 

http://www.epa.gov/epahome/dockets.htm. 
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Docket. The EPA has established a docket for this 

rulemaking under Docket ID Number EPA-HQ-OAR-2004-0305. All 

documents in the docket are listed in the www.regulations.gov

index. Although listed in the index, some information is not 

publicly available, e.g., CBI or other information whose 

disclosure is restricted by statute. Certain other material, 

such as copyrighted material, is not placed on the Internet and 

will be publicly available only in hard copy. Publicly 

available docket materials are available either electronically 

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

EPA West, Room 3334, 1301 Constitution Ave., NW, Washington, DC. 

The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., 

Monday through Friday, excluding legal holidays. The telephone 

number for the Public Reading Room is (202) 566-1744, and the 

telephone number for the EPA Docket Center is (202) 566-1742. 

Public Hearing. If a public hearing is held, it will begin 

at 10:00 a.m. on [INSERT DATE 15 DAYS FROM DATE OF PUBLICATION 

IN THE FEDERAL REGISTER] and will be held at EPA’s campus in 

Research Triangle Park, North Carolina, or at an alternate 

facility nearby. Persons interested in presenting oral testimony 

or inquiring as to whether a public hearing is to be held should 

contact Ms. Virginia Hunt, Office of Air Quality Planning and 

Standards, Sector Policies and Programs Division, Metals and 

Minerals Group (D243-02), U.S. Environmental Protection Agency, 
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Research Triangle Park, North Carolina 27711; telephone number: 

(919) 541–0832. 

FOR FURTHER INFORMATION CONTACT: For questions about this 

proposed action, contact Ms. Sharon Nizich, Sector Policies and 

Programs Division (D243-02), Office of Air Quality Planning and 

Standards, U.S. Environmental Protection Agency, Research 

Triangle Park, North Carolina 27711, telephone (919) 541-2825; 

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

nizich.sharon@epa.gov. For specific information regarding the 

risk modeling methodology, contact Ms. Elaine Manning, Health 

and Environmental Impacts Division (C539-02), Office of Air 

Quality Planning and Standards, U.S. Environmental Protection 

Agency, Research Triangle Park, North Carolina 27711; telephone 

number: (919) 541–5499; fax number: (919) 541–0840; and e-mail 

address: manning.elaine@epa.gov. For information about the 

applicability of the NESHAP to a particular entity, contact the 

appropriate person listed in Table 1 to this preamble. 

TABLE 1--LIST OF EPA CONTACTS FOR THE NESHAP ADDRESSED IN THIS 

PROPOSED ACTION 

NESHAP for: OECA Contact1

 OAQPS Contact2

Primary Lead 

Smelting 

Maria Malave, (202)564-

7027 

malave.maria@epa.gov 

Sharon Nizich, (919) 

541-2825, 

nizich.sharon@epa.gov 1

 EPA’s Office of Enforcement and Compliance Assurance. 

2

 EPA’s Office of Air Quality Planning and Standards. 

SUPPLEMENTARY INFORMATION: 

I. Preamble Acronyms and Abbreviations 
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 Several acronyms and terms used to describe industrial 

processes, data inventories, and risk modeling are included in 

this preamble. While this may not be an exhaustive list, to 

ease the reading of this preamble and for reference purposes, 

the following terms and acronyms are defined here: 

ADAF Age-dependent Adjustment Factors 

AERMOD Air dispersion model used by the HEM-3 model 

AEGL Acute Exposure Guideline Levels 

ANPRM Advance Notice of Proposed Rulemaking 

BACT Best Available Control Technology 

CAA Clean Air Act 

CBI Confidential Business Information 

CEEL Community Emergency Exposure Levels 

CEMS Continuous Emissions Monitoring System 

CERMS Continuous Emission Rate Monitoring System 

CFR Code of Federal Regulations 

EJ Environmental Justice 

EPA Environmental Protection Agency 

ERPG Emergency Response Planning Guidelines 

HAP Hazardous Air Pollutants 

HI Hazard Index 

HEM-3 Human Exposure Model version 3 

HON Hazardous Organic National Emissions Standards for 

Hazardous Air Pollutants 

HQ Hazard Quotient 

IRIS Integrated Risk Information System 

Km Kilometer 

LAER Lowest Achievable Emission Rate 

LOAEL Lowest Observed Adverse Effect Level 

MACT Maximum Achievable Control Technology 

MACT Code Code within the NEI used to identify processes 

included in a source category 

MIR Maximum Individual Risk 

NAAQS National Ambient Air Quality Standard 

NAC/AEGL 

Committee National Advisory Committee for Acute Exposure 

Guideline Levels for Hazardous Substances 

NAICS North American Industry Classification System 

NAS National Academy of Sciences 

NATA National Air Toxics Assessment 

NESHAP National Emissions Standards for Hazardous Air 

Pollutants 
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NEI National Emissions Inventory 

NOAEL No Observed Adverse Effects Level 

NRC National Research Council 

NTTAA National Technology Transfer and Advancement Act 

OAQPS EPA’s Office of Air Quality Planning and Standards 

OECA EPA’s Office of Enforcement and Compliance 

Assurance 

OMB Office of Management and Budget 

PB-HAP Hazardous air pollutants known to be persistent and 

bio-accumulative in the environment 

POM Polycyclic Organic Matter 

RACT Reasonably Available Control Technology 

RBLC RACT/BACT/LAER Clearinghouse 

RFA Regulatory Flexibility Act 

RfC Reference Concentration 

RfD Reference Dose 

RTR Residual Risk and Technology Review 

SAB Science Advisory Board 

SBA Small Business Administration 

SCC Source Classification Codes 

SF3 2000 Census of Population and Housing Summary File 3 

SIP State Implementation Plan 

SOP Standard Operating Procedures 

SSM Startup, Shutdown, and Malfunction 

TOSHI Target Organ-Specific Hazard Index 

TPY Tons Per Year 

TRIM Total Risk Integrated Modeling System 

TTN Technology Transfer Network 

UF Uncertainty Factor 

UMRA Unfunded Mandates Reform Act 

URE Unit Risk Estimate 

VOC Volatile Organic Compounds 

VOHAP Volatile Organic Hazardous Air Pollutants 

WWW Worldwide Web 

 Organization of this Document. The following outline is 

provided to aid in the location of information in this preamble. 

I. Preamble Acronyms and Abbreviations 

II. General Information 

A. Does this action apply to me? 

B. Where can I get a copy of this document and other related 

information? 

C. What should I consider as I prepare my comments for EPA? 

III. Background 

A. What is the statutory authority for this action? 
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B. How did we consider the risk results in making decisions 

for this proposal? 

C. What other actions are we addressing in this proposal? 

IV. Analyses Performed and Background for the Source Category 

and MACT Standard 

A. How did we estimate risks posed by the source category? 

B. How did we perform the technology review? 

C. Overview of the source category and MACT standards 

V. Analyses Results and Proposed Decisions 

A. What data were used in our risk analyses? 

B. What are the results of the risk assessments and analyses? 

C. What are our proposed decisions on risk acceptability and 

ample margin of safety? 

D. What are the results and proposed decisions from the 

technology review? 

E. Variability 

F. What other actions are we proposing? 

VI. Proposed Action 

A. What actions are we proposing as a result of the residual 

risk reviews? 

B. What actions are we proposing as a result of the technology 

reviews? 

C. What other actions are we proposing? 

VII. Request for Comments 

VIII.Submitting Data Corrections 

IX. 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 and Advancement Act 

J. Executive Order 12898: Federal Actions to Address 

 Environmental Justice in Minority Populations and Low- 

 Income Populations 

II. General Information 

A. Does this action apply to me?
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 The regulated industrial source category that is the 

subject of this proposal is listed in Table 2 to this preamble. 

Table 2 is not intended to be exhaustive, but rather provides a 

guide for readers regarding entities likely to be affected by 

the proposed action for the source categories listed. This 

standard, and any changes considered in this rulemaking, would 

be directly applicable to sources as a Federal program. Thus, 

Federal, State, local, and tribal government entities are not 

affected by this proposed action. As defined in the source 

category listing report published by EPA in 1992, the Primary 

Lead Smelting source category is defined as any facility engaged 

in producing lead metal from ore concentrates; including, but 

not limited to, the following smelting processes: sintering, 

reduction, preliminary treatment, and refining operations.1

 As 

discussed in section III. (C)(3), to be consistent with the 1992 

listing, EPA is proposing to change the applicability of the 

Primary Lead Smelting NESHAP to apply to any facility that 

produces lead metal from lead ore concentrates. Although the 

source category name in the 1992 listing will remain Primary 

Lead Smelting (as in 1992 listing) we are proposing to change 

the title of the rule to refer to Primary Lead Processing. For 

clarification purposes, all references to lead emissions in this 

 

1 USEPA. Documentation for Developing the Initial Source Category List –

Final Report, USEPA/OAQPS, EPA-450/3-91-030, July, 1992. 
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preamble means “lead compounds” (which is a HAP) and all 

reference to lead production means elemental lead (which is not 

a HAP)as provided under CAA 112(b)(7)). 

TABLE 2--NESHAP AND INDUSTRIAL SOURCE CATEGORIES AFFECTED BY 

THIS PROPOSED ACTION 

Source Category NESHAP NAICS code1

MACT 

code2

Primary Lead 

Smelting

Primary Lead 

Processing 

331419 0204 

1

 North American Industry Classification System 

2

 Maximum Achievable Control Technology 

B. Where can I get a copy of this document and other related 

information?

In addition to being available in the docket, an electronic 

copy of this proposal will also be available on the World Wide 

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

Following signature by the EPA Administrator, a copy of this 

proposed action will be posted on the TTN’s policy and guidance 

page for newly proposed or promulgated rules at the following 

address: http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. The TTN 

provides information and technology exchange in various areas of 

air pollution control. 

Additional information is available on the residual risk 

and technology review (RTR) web page at 

http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. This information 

includes source category descriptions and detailed emissions and 

other data that were used as inputs to the risk assessments. 
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C. What should I consider as I prepare my comments for EPA?

 Submitting CBI. Do not submit information containing CBI 

to EPA through www.regulations.gov or e-mail. Clearly mark the 

part or all of the information that you claim to be CBI. For 

CBI information on a disk or CD ROM that you mail to EPA, mark 

the outside of the disk or CD ROM as CBI and then identify 

electronically within the disk or CD ROM the specific 

information that is claimed as CBI. In addition to one complete 

version of the comment that includes information claimed as CBI, 

a copy of the comment that does not contain the information 

claimed as CBI must be submitted for inclusion in the public 

docket. If you submit a CD ROM or disk that does not contain 

CBI, mark the outside of the disk or CD ROM clearly that it does 

not contain CBI. Information not marked as CBI will be included 

in the public docket and EPA’s electronic public docket without 

prior notice. Information marked as CBI will not be disclosed 

except in accordance with procedures set forth in 40 CFR part 2. 

Send or deliver information identified as CBI only to the 

following address: Roberto Morales, OAQPS Document Control 

Officer (C404-02), Office of Air Quality Planning and Standards, 

U.S. Environmental Protection Agency, Research Triangle Park, 

North Carolina 27711, Attention Docket ID Number EPA-HQ-OAR2004-0305. 

III. Background 
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A. What is the statutory authority for this action? 

Section 112 of the Clean Air Act (CAA) establishes a twostage regulatory process to address emissions of hazardous air 

pollutants (HAP) from stationary sources. In the first stage, 

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) of the CAA calls for us to promulgate NESHAP for those 

sources. “Major sources” are those 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 any combination of HAP. For major sources, 

these technology-based standards must reflect the maximum degree 

of emission 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. 

MACT standards must require the maximum degree of emission 

reduction through the application of measures, processes, 

methods, systems, or techniques, including, but not limited to, 

measures which (A) reduce the volume of or eliminate pollutants 

through process changes, substitution of materials or other 

modifications; (B) enclose systems or processes to eliminate 

emissions; (C) capture or treat pollutants when released from a 

process, stack, storage, or fugitive emissions point; (D) are 

design, equipment, work practice, or operational standards 
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(including requirements for operator training or certification); 

or (E) are a combination of the above. CAA section 

112(d)(2)(A)-(E). The MACT standards may take the form of 

design, equipment, work practice, or operational standards where 

EPA first determines either that, (A) a pollutant cannot be 

emitted through a conveyance designed and constructed to emit or 

capture the pollutants, or that any requirement for, or use of, 

such a conveyance would be inconsistent with law; or (B) the 

application of measurement methodology to a particular class of 

sources is not practicable due to technological and economic 

limitations. CAA sections 112(h)(1)-(2). 

The MACT “floor” is the minimum control level allowed for 

MACT standards promulgated under CAA section 112(d)(3) and may 

not be based on cost considerations. 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 floors for existing sources can be less stringent than 

floors for new sources, but they cannot be less stringent than 

the average emissions limitation achieved by the best-performing 

12 percent of existing sources in the category or subcategory 

(or the best-performing 5 sources for categories or 

subcategories with fewer than 30 sources). In developing MACT 

standards, we must also consider control options that are more 

stringent than the floor. We may establish standards more 
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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. 

The EPA is then required to review these technology-based 

standards and to revise them “as necessary (taking into account 

developments in practices, processes, and control technologies)” 

no less frequently than every 8 years, under CAA section 

112(d)(6). In conducting this review, EPA is not obliged to 

completely recalculate the prior MACT determination. NRDC v. 

EPA, 529 F.3d 1077, 1084 (D. C. Cir., 2008). 

The second stage in standard-setting focuses on reducing 

any remaining “residual” risk according to CAA section 112(f). 

This provision requires, first, that EPA prepare a Report to 

Congress discussing (among other things) methods of calculating 

the risks posed (or potentially posed) by sources after 

implementation of the MACT standards, the public health 

significance of those risks, and the recommendations regarding 

legislation of such remaining risk. EPA prepared and submitted 

this report (Residual Risk Report to Congress, EPA–453/R–99–001) 

in March 1999. Congress did not act in response to the report, 

thereby triggering EPA’s obligation under CAA section 112(f)(2) 

to analyze and address residual risk. 

Section 112(f)(2) of the CAA requires us to determine for 

source categories subject to certain MACT standards, whether the 
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emissions standards provide an ample margin of safety to protect 

public health. If the MACT standards that apply to a source 

category emitting a HAP that is “classified as a known, 

probable, or possible human carcinogen do not reduce lifetime 

excess cancer risks to the individual most exposed to emissions 

from a source in the category or subcategory to less than onein-one million,” EPA must promulgate residual risk standards for 

the source category (or subcategory) as necessary to provide an 

ample margin of safety to protect public health. CAA section 

112(f)(2)(A). In doing so, EPA may adopt standards equal to 

existing MACT standards if EPA determines that the existing 

standards are sufficiently protective. As stated in NRDC v. 

EPA, 529 F.3d 1077, 1083 (D.C. Dir. 2008), “If EPA determines 

that the existing technology-based standards provide an ‘ample 

margin of safety,’ then the Agency is free to readopt those 

standards during the residual risk rulemaking.” Section 

112(f)(2) of the Clean Air Act further states that EPA must also 

adopt more stringent standards, if necessary, to “prevent taking 

into consideration costs, energy, safety, and other relevant 

factors, an adverse environmental effect.”2

 

 

2 “Adverse environmental effect” is defined in CAA section 112(a)(7) as 

any significant and widespread adverse effect, which may be reasonably 

anticipated to wildlife, aquatic life, or natural resources, including 

adverse impacts on populations of endangered or threatened species or 

significant degradation of environmental qualities over broad areas.
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When Section 112(f)(2) of the CAA was enacted in 1990, it 

expressly preserved our use of the two-step process for 

developing standards to address any residual risk and our 

interpretation of “ample margin of safety” developed in the 

National Emission Standards for Hazardous Air Pollutants: 

Benzene Emissions from Maleic Anhydride Plants, 

Ethylbenzene/Styrene Plants, Benzene Storage Vessels, Benzene

Equipment Leaks, and Coke By-Product Recovery Plants (Benzene 

NESHAP) (54 FR 38044, September 14, 1989). The first step in 

this process is the determination of acceptable risk. The 

second step provides for an ample margin of safety to protect 

public health, which is the level at which the standards are set 

(unless a more stringent standard is required to prevent, taking 

into consideration costs, energy, safety, and other relevant 

factors, an adverse environmental effect). 

The terms “individual most exposed,” “acceptable level,” 

and “ample margin of safety” are not specifically defined in the 

CAA. However, CAA section 112(f)(2)(B) preserves the 

interpretation set out in the Benzene NESHAP, and the Court in 

NRDC v. EPA, concluded that EPA’s interpretation of subsection 

112(f)(2) is a reasonable one. See NRDC v. EPA, 529 F.3d at 

1083 (D. C. Cir. 2008), which says “[S]ubsection 112(f)(2)(B) 

expressly incorporates EPA’s interpretation of the Clean Air Act 

from the Benzene standard, complete with a citation to the 
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Federal Register.” See also, A Legislative History of the Clean 

Air Act Amendments of 1990, volume 1, p. 877 (Senate debate on 

Conference Report). We notified Congress in the Residual Risk 

Report to Congress that we intended to use the Benzene NESHAP 

approach in making CAA section 112(f) residual risk 

determinations (EPA–453/R–99–001, p. ES–11). 

In the Benzene NESHAP, we stated as an overall objective: 

* * * in protecting public health with an ample margin of 

safety, we strive to provide maximum feasible protection 

against risks to health from hazardous air pollutants by 

(1) protecting the greatest number of persons possible to 

an individual lifetime risk level no higher than 

approximately 1-in-1 million; and (2) limiting to no higher 

than approximately 1-in-10 thousand [i.e., 100-in-1 

million] the estimated risk that a person living near a 

facility would have if he or she were exposed to the 

maximum pollutant concentrations for 70 years. 

The Agency also stated that, “The EPA also considers 

incidence (the number of persons estimated to suffer cancer or 

other serious health effects as a result of exposure to a 

pollutant) to be an important measure of the health risk to the 

exposed population. Incidence measures the extent of health 

risks to the exposed population as a whole, by providing an 

estimate of the occurrence of cancer or other serious health 
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effects in the exposed population.” The Agency went on to 

conclude that “estimated incidence would be weighed along with 

other health risk information in judging acceptability.” As 

explained more fully in our Residual Risk Report to Congress, 

EPA does not define “rigid line[s] of acceptability,” but 

considers rather broad objectives to be weighed with a series of 

other health measures and factors (EPA–453/R–99–001, p. ES–11). 

The determination of what represents an “acceptable” risk is 

based on a judgment of “what risks are acceptable in the world 

in which we live” (Residual Risk Report to Congress, p. 178, 

quoting the Vinyl Chloride decision at 824 F.2d 1165) 

recognizing that our world is not risk-free. 

In the Benzene NESHAP, we stated that “EPA will generally 

presume that if the risk to [the maximum exposed] individual is 

no higher than approximately 1-in-10 thousand, that risk level 

is considered acceptable.” 54 FR 38045. We discussed the 

maximum individual lifetime cancer risk as being “the estimated 

risk that a person living near a plant would have if he or she 

were exposed to the maximum pollutant concentrations for 70 

years.” Id. We explained that this measure of risk “is an 

estimate of the upper bound of risk based on conservative 

assumptions, such as continuous exposure for 24 hours per day 

for 70 years.” Id. We acknowledge that maximum individual 

lifetime cancer risk “does not necessarily reflect the true 
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risk, but displays a conservative risk level which is an upperbound that is unlikely to be exceeded.” Id. 

Understanding that there are both benefits and limitations 

to using maximum individual lifetime cancer risk as a metric for 

determining acceptability, we acknowledged in the 1989 Benzene 

NESHAP that “consideration of maximum individual risk * * * must 

take into account the strengths and weaknesses of this 

measure of risk.” Id. Consequently, the presumptive risk level 

of 100-in-1 million (1-in-10 thousand) provides a benchmark for 

judging the acceptability of maximum individual lifetime cancer 

risk, but does not constitute a rigid line for making that 

determination. 

The Agency also explained in the 1989 Benzene NESHAP the 

following: “In establishing a presumption for MIR [maximum 

individual cancer risk], rather than a rigid line for 

acceptability, the Agency intends to weigh it with a series of 

other health measures and factors. These include the overall 

incidence of cancer or other serious health effects within the 

exposed population, the numbers of persons exposed within each 

individual lifetime risk range and associated incidence within, 

typically, a 50-kilometer (km) exposure radius around 

facilities, the science policy assumptions and estimation 

uncertainties associated with the risk measures, weight of the 

scientific evidence for human health effects, other quantified 
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or unquantified health effects, effects due to co-location of 

facilities, and co-emission of pollutants.” Id.

In some cases, these health measures and factors taken 

together may provide a more realistic description of the 

magnitude of risk in the exposed population than that provided 

by maximum individual lifetime cancer risk alone. As explained 

in the Benzene NESHAP, “[e]ven though the risks judged 

“acceptable” by EPA in the first step of the Vinyl Chloride 

inquiry are already low, the second step of the inquiry, 

determining an “ample margin of safety,” again includes 

consideration of all of the health factors, and whether to 

reduce the risks even further.” In the ample margin of safety 

decision process, the Agency again considers all of the health 

risks and other health information considered in the first step. 

Beyond that information, additional factors relating to the 

appropriate level of control will also be considered, including 

costs and economic impacts of controls, technological 

feasibility, uncertainties, and any other relevant factors. 

Considering all of these factors, the Agency will establish the 

standard at a level that provides an ample margin of safety to 

protect the public health, as required by CAA section 112(f). 

54 FR 38046. 

B. How did we consider the risk results in making decisions

for this proposal?
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As discussed in section III.A of this preamble, we apply a 

two-step process for developing standards to address residual 

risk. In the first step, EPA determines if risks are 

acceptable. This determination “considers all health 

information, including risk estimation uncertainty, and includes 

a presumptive limit on maximum individual lifetime [cancer] risk 

(MIR)3

 of approximately 1-in-10 thousand [i.e., 100-in-1 

million].” 54 FR 38045. In the second step of the process, EPA 

sets the standard at a level that provides an ample margin of 

safety “in consideration of all health information, including 

the number of persons at risk levels higher than approximately 

1-in-1 million, as well as other relevant factors, including 

costs and economic impacts, technological feasibility, and other 

factors relevant to each particular decision.” Id. 

In past residual risk actions, EPA has presented and 

considered a number of human health risk metrics associated with 

emissions from the category under review, including: the MIR; 

the numbers of persons in various risk ranges; cancer incidence; 

the maximum non-cancer hazard index (HI); and the maximum acute 

non-cancer hazard (72 FR 25138, May 3, 2007; 71 FR 42724, July 

27, 2006). In our most recent proposals (75 FR 65068, October 

 

3 Although defined as “maximum individual risk,” MIR refers only to 

cancer risk. MIR, one metric for assessing cancer risk, is the 

estimated risk were an individual exposed to the maximum level of a 

pollutant for a lifetime.
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21, 2010 and 75 FR 80220, December 21, 2010),, EPA also 

presented and considered additional measures of health 

information, including: estimates of “facility-wide” risks 

(risks from all HAP emissions from the facility at which the 

source category is located)4

; demographic analyses (analyses of 

the distributions of HAP-related risks across different social, 

demographic, and economic groups living near the facilities); 

and estimates of the risks associated with the maximum level of 

emissions which might be allowed by the current MACT standards 

(see, e.g., 75 FR 65068, October 21, 2010 and 75 FR 80220, 

December 21, 2010). EPA also discussed and considered risk 

estimation uncertainties. EPA is providing this same type of 

information in support of the proposed actions described in this 

Federal Register notice. 

The Agency is considering all available health information 

to inform our determinations of risk acceptability and ample 

margin of safety under CAA section 112(f). Specifically, as 

explained in the Benzene NESHAP, “the first step judgment on 

acceptability cannot be reduced to any single factor” and thus 

“[t]he Administrator believes that the acceptability of risk 

under section 112 is best judged on the basis of a broad set of 

health risk measures and information.” 54 FR at 38046. 

 

4 EPA previously provided estimates of total facility risk in a residual risk 

proposal for coke oven batteries (69 FR 48338, August 9, 2004). 
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Similarly, with regard to making the ample margin of safety 

determination, as stated in the Benzene NESHAP “[I]n the ample 

margin decision, the Agency again considers all of the health 

risk and other health information considered in the first step. 

Beyond that information, additional factors relating to the 

appropriate level of control will also be considered, including 

cost and economic impacts of controls, technological 

feasibility, uncertainties, and any other relevant factors.” 

Id.

The Agency acknowledges that flexibility is provided by the 

Benzene NESHAP regarding what factors EPA might consider in 

making determinations and how they might be weighed for each 

source category. In responding to comment on our policy under 

the Benzene NESHAP, EPA explained that: “The policy chosen by 

the Administrator permits consideration of multiple measures of 

health risk. Not only can the MIR figure be considered, but 

also incidence, the presence of non-cancer health effects, and 

the uncertainties of the risk estimates. In this way, the 

effect on the most exposed individuals can be reviewed as well 

as the impact on the general public. These factors can then be 

weighed in each individual case. This approach complies with 

the Vinyl Chloride mandate that the Administrator ascertain an 

acceptable level of risk to the public by employing [her] 

expertise to assess available data. It also complies with the 
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Congressional intent behind the CAA, which did not exclude the 

use of any particular measure of public health risk from the 

EPA's consideration with respect to CAA section 112 regulations, 

and, thereby, implicitly permits consideration of any and all 

measures of health risk which the Administrator, in [her] 

judgment, believes are appropriate to determining what will 

‘protect the public health.’” 54 FR at 38057. 

For example, the level of the MIR is only one factor to be 

weighed in determining acceptability of risks. It is explained 

in the Benzene NESHAP that “an MIR of approximately 1-in-10 

thousand should ordinarily be the upper end of the range of 

acceptability. As risks increase above this benchmark, they 

become presumptively less acceptable under CAA section 112, and 

would be weighed with the other health risk measures and 

information in making an overall judgment on acceptability. Or, 

the Agency may find, in a particular case, that a risk that 

includes MIR less than the presumptively acceptable level is 

unacceptable in the light of other health risk factors.” Id. at 

38045. Similarly, with regard to the ample margin of safety 

analysis, EPA stated in the Benzene NESHAP that: “...EPA believes 

the relative weight of the many factors that can be considered 

in selecting an ample margin of safety can only be determined 

for each specific source category. This occurs mainly because 

technological and economic factors (along with the health-
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related factors) vary from source category to source category.” 

Id. at 38061. 

EPA wishes to point out that certain health information has 

not been considered to date in making residual risk 

determinations. In assessing risks to populations in the 

vicinity of the facilities in each category, we present 

estimates of risk associated with HAP emissions from the source 

category alone (source category risk estimates) and HAP 

emissions from the entire facility at which the covered 

source category is located (facility-wide risk estimates). We 

do not attempt to characterize the risks associated with all HAP 

emissions impacting the populations living near the sources in 

these categories. That is, at this time, we do not attempt to 

quantify those HAP risks that may be associated with mobile 

source emissions, natural source emissions, persistent 

environmental pollution, or atmospheric transformation in the 

vicinity of the sources in these categories. 

The Agency understands the potential importance of 

considering an individual’s total exposure to HAP in addition to 

considering exposure to HAP emissions from the source category 

and facility. This is particularly important when assessing 

non-cancer risks, where pollutant-specific exposure levels 

(e.g., Reference Concentration (RfC)) are based on the 

assumption that thresholds exist for adverse health effects. 
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For example, the Agency recognizes that, although exposures 

attributable to emissions from a source category or facility 

alone may not indicate the potential for increased risk of 

adverse non-cancer health effects in a population, the exposures 

resulting from emissions from the facility in combination with 

emissions from all of the other sources (e.g., other facilities) 

to which an individual is exposed may be sufficient to result in 

increased risk of adverse non-cancer health effects. In May 

2010, the Science Advisory Board (SAB) advised us “... that RTR 

assessments will be most useful to decision makers and 

communities if results are presented in the broader context of 

aggregate and cumulative risks, including background 

concentrations and contributions from other sources in the 

area.”5 

While we are interested in placing source category and 

facility-wide HAP risks in the context of total HAP risks from 

all sources combined in the vicinity of each source, we are 

concerned about the uncertainties of doing so. At this point, 

we believe that such estimates of total HAP risks will have 

 

5

 EPA’s responses to this and all other key recommendations of the 

SAB’s advisory on RTR risk assessment methodologies (which is 

available at: 

http://yosemite.epa.gov/sab/sabproduct.nsf/4AB3966E263D943A8525771F006

68381/$File/EPA-SAB-10-007-unsigned.pdf) are outlined in a memo to 

this rulemaking docket from David Guinnup entitled, EPA’s Actions in 

Response to the Key Recommendations of the SAB Review of RTR Risk 

Assessment Methodologies.
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significantly greater associated uncertainties than for the 

source category or facility-wide estimates, hence compounding 

the uncertainty in any such comparison. This is because we have 

not conducted a detailed technical review of HAP emissions data 

for source categories and facilities that have not previously 

undergone an RTR review or are not currently undergoing such 

review. We are requesting comment on whether and how best to 

estimate and evaluate total HAP exposure in our assessments, 

and, in particular, on whether and how it might be appropriate 

to use information from EPA’s National Air Toxics Assessment 

(NATA) to support such estimates. We are also seeking comment 

on how best to consider various types and scales of risk 

estimates when making our acceptability and ample margin of 

safety determinations under CAA section 112(f). Additionally, 

we are seeking comments and recommendations for any other 

comparative measures that may be useful in the assessment of the 

distribution of HAP risks across potentially affected 

demographic groups. 

C. What other actions are we addressing in this proposal?

 1. Startup, Shutdown and Malfunction. 

This proposed action would amend the provisions of the 

existing NESHAP that apply to periods of startup, shutdown, and 

malfunction (SSM). The proposed revisions of these provisions 

result from a Court decision that vacated portions of two 
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provisions in EPA’s “General Provisions” regulation under CAA 

section 112, governing the emissions of HAP during periods of 

SSM. The current Primary Lead Smelting MACT includes references 

to the vacated provisions in the General Provisions rule. 

We are proposing to revise the Primary Lead Smelting MACT 

standard to require affected sources to comply with the emission 

limitations at all times and during periods of SSM. 

Specifically, we are proposing several revisions to subpart TTT 

including revising Table 1 to indicate that the requirements of 

the General Provisions pertaining to SSM do not apply and to 

revise language in section 63.1547 (g)(1) and (2) to remove the 

exemption for bag leak detection alarm time attributable to SSM 

from total allowed alarm time. For reasons discussed below, we 

are also proposing to promulgate an affirmative defense to civil 

penalties for exceedances of emission standards caused by 

malfunctions, as well as criteria for establishing the 

affirmative defense. These changes would go into effect upon 

the effective date of promulgation of the final rule. 

 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 exemptions contained in 40 CFR 
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63.6(f)(1) and 40 CFR 63.6(h)(1), that are part of a regulation 

commonly known as the “General Provisions Rule,” that EPA had 

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. 

We are proposing the elimination of the SSM exemption in 

this rule. Consistent with Sierra Club v. EPA, EPA is proposing 

standards in this rule that apply at all times. We are also 

proposing several revisions to Table 1 (the General Provisions 

Applicability table). For example, we are proposing to 

eliminate the incorporation of the General Provisions’ 

requirement that the source develop an SSM plan. We also are 

proposing to eliminate or revise certain recordkeeping and 

reporting that relate to the SSM exemption. EPA has attempted 

to ensure that we have not included in the proposed regulatory 

language any provisions that are inappropriate, unnecessary, or 

redundant in the absence of the SSM exemption. We are 

specifically seeking comment on whether there are any such 

provisions that we have inadvertently incorporated or 

overlooked. 

In proposing standards in this rule, EPA has taken into 

account startup and shutdown periods and, for the reasons 
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explained below, has not proposed different standards for those 

periods. Information on periods of startup and shutdown in the 

industry indicate that emissions during these periods do not 

increase. Furthermore, all processes are controlled by either 

control devices or work practices and these controls would not 

typically be affected by an SSM event. Also, compliance with 

the standard already requires averaging of emissions over a 

three month period, which accounts for the variability of 

emissions that may result during periods of startup and 

shutdown. Therefore, separate standards for periods of startup 

and shutdown are not being proposed. 

Periods of startup, normal operations, and shutdown are all 

predictable and routine aspects of a source’s operations. 

However, by contrast, malfunction is defined as a “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 useful manner * * * ” (40 

CFR 63.2). EPA has determined that malfunctions should not be 

viewed as a distinct operating mode 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 
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variability of emissions under all operating conditions. 

However, nothing in section 112(d) or in case law 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 

not requiring EPA to account for malfunctions in setting 

emission standards. For example, we note that CAA 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 as 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 
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malfunctions into account in setting CAA section 112(d) 

standards for Primary Lead Smelting. 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 unlikely event that a source fails to comply with 

the applicable CAA section 112(d) standards as a result of a 

malfunction event, EPA would 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 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 

CFR 63.2 (definition of malfunction). 

Finally, EPA recognizes that even equipment that is 

properly designed and maintained can sometimes fail and that 

such failure can sometimes cause or contribute to an exceedance 

of the relevant emission standard. (See, e.g., State 
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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 proposing to add to the final rule an affirmative 

defense to civil penalties for exceedances of emission limits 

that are caused by malfunctions. See 40 CFR 63.1542 (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 are proposing 

other regulatory provisions to specify the elements that are 

necessary 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 63.1551. (See 40 CFR 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 CFR 63.2 

(sudden, infrequent, not reasonably preventable and not caused 

by poor maintenance and/or careless operation). For example, to 

successfully assert the affirmative defense, the source must 

prove by a preponderance of the evidence that excess emissions 

“[w]ere caused by a sudden, short, infrequent, and unavoidable 
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failure of air pollution control and monitoring equipment, 

process equipment, or a process to operate in a normal or usual 

manner....” The criteria also are designed to ensure that steps 

are taken to correct the malfunction, to minimize emissions in 

accordance with Section 63.1543(i) and 63.1544(e) and to prevent 

future malfunctions. For example, the source must prove by a 

preponderance of the evidence that “[r]epairs were made as 

expeditiously as possible when the applicable emission 

limitations were being exceeded...” and that “[a]ll possible steps 

were taken to minimize the impact of the excess emissions on 

ambient air quality, the environment and human health....” 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 CFR Part 22.77). 

Specifically, we are proposing the following changes to the 

rule. 

 Added general duty requirements in §63.1543 and §63.1544 to 

replace General Provision requirements that reference vacated 

SSM provisions. 

 Added replacement language that eliminates the reference to 

SSM exemptions applicable to performance tests in 63.1546. 
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 Added paragraphs in 63.1549(e) requiring the reporting of 

malfunctions as part of the affirmative defense provisions. 

 Added paragraphs in 63.1549(b) requiring the keeping of 

certain records during malfunctions as part of the affirmative 

defense provisions. 

 Revised Table 1 to reflect changes in the applicability of the 

General Provisions to this subpart resulting from a court 

vacatur of certain SSM requirements in the General Provisions. 

 2. Lead as a surrogate and regulation of volatile organic 

compounds (VOC) and acid gas emissions. 

In a January 14, 2009 petition for rulemaking filed by the 

Natural Resources Defense Council and Sierra Club, the 

petitioners claim that for the Primary Lead Smelting MACT, EPA 

relied on lead as a surrogate for all HAP and they claim that it 

was inappropriate for EPA to do so in absence of a showing that 

lead is an appropriate surrogate for all other HAP (such as 

mercury, acid gases, and volatile organic compounds (VOC)). The 

petitioners asserted that EPA should set standards for other HAP 

absent a showing that lead is an appropriate surrogate for these 

HAP. They also assert that EPA’s PM standard does not reflect 

the emission level achieved by the best performing sources and 

that EPA must re-open the rule to set floors for PM in 

accordance with CAA section 112(d)(3). A copy of the petition 
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is included in the docket. 

As part of this rulemaking, EPA is responding to the claims 

made by the petitioners regarding the Primary Lead Smelting 

MACT. 

As an initial matter, the petitioners are incorrect in 

their claim that EPA considers lead as a surrogate for all HAP. 

Rather, EPA used lead as a surrogate only for other metal HAP 

compounds in establishing the emissions limit in the current 

MACT standard for this source category (63 FR 19206 and 64 FR 

30195). EPA determined in the 1999 rule that lead, a 

nonvolatile metal HAP, is an appropriate surrogate for other 

nonvolatile metal HAP including antimony, arsenic, chromium, 

nickel, manganese, and cadmium. In the proposed rule for the 

Primary Lead Smelting MACT (63 FR 19206), EPA discussed the use 

of lead as a surrogate for metal HAP emissions and explained 

that strong correlations exist between emissions of lead and 

other metal HAP and that the technologies identified for the 

control of metal HAP are the same as those used to control lead 

emissions. Therefore, EPA expected that the standards requiring 

control of lead would achieve similar control of the other metal 

HAP emitted from primary lead smelters. No adverse comments 

were received regarding EPA’s proposed rationale for relying on 

lead as a surrogate for other metal HAP emitted by these sources 

and EPA adopted that rationale in the final rule promulgating 
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the Primary Lead Smelting MACT. The petitioners do not have any 

substantive basis as to why EPA’s rationale is not supported. 

Nor do they claim that there is any new information that would 

support re-opening this issue. Thus they fail to present a 

basis for re-opening this issue. 

The petitioners also insist that EPA should have set 

standards for VOC and acid gases that are HAP because lead would 

not be a surrogate for these pollutants. EPA noted in the 

original proposal that due to small amounts of coke fed to the 

blast furnace, organic HAP (VOC) was emitted at a rate so low as 

to be infeasible to reduce. Again, no adverse comments were 

received on EPA’s proposed conclusions, which were adopted in 

the final rule, and the petitioners do not now provide 

substantive support for their claim. Nor do they explain why 

any such claim could not have been raised during the initial 

rulemaking. Thus, they fail to present a basis for re-opening 

the rule on this issue. 

Finally, Petitioners claim that the “PM standard does not 

reflect the emission level achieved by the best performing 

sources.” This claim is unclear as there is no PM standard in 

the Primary Lead Smelting MACT. The monitoring provisions 

provide that PM should be measured in relation to a 

predetermined PM level as one test for indicating baghouse 

performance. However, the PM levels are not enforceable 
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emission limits, but merely an indication that the baghouse may 

not be operating properly. Again, these provisions were clearly 

explained in the proposed and final Primary Lead Smelting MACT 

rulemakings. Any claims concerning the appropriateness of these 

monitoring requirements should have been raised during the 

initial rulemaking process. Petitioners do not claim any new 

grounds for raising this issue now. Thus, the petition fails to 

provide a basis for re-opening the MACT. 

3. Modification of the Applicability Provision.

EPA is proposing to amend the applicability section to 

apply to any facility processing lead ore concentrate to produce 

lead metal. Under the current applicability provisions, the 

affected sources include any sinter machine, blast furnace, 

dross furnace, process fugitive source, and fugitive dust source 

located at a primary lead smelter and excludes secondary lead 

smelters, lead refiners, or lead remelters. Combined with the 

current definition for “primary lead smelter,” the current rule 

effectively only applies to facilities that produce lead metal 

from lead sulfide ore concentrates using pyrometallurgical 

techniques. While the only processes available for the 

production of lead from lead ore concentrate at the time the 

MACT rule was developed were pyrometallurgical techniques, that 

applicability language is narrower than the primary lead 

smelting source category description EPA identified in its 
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source category listing issued pursuant to CAA section 

112(c)(1), Documentation for Developing the Initial Source 

Category List (EPA-450/3-91-030, July 1992). In the source 

category listing, EPA defined the primary lead smelting source 

category as follows: “The Primary Lead Smelting source category 

includes any facility engaged in producing lead metal from ore 

concentrates. The category includes, but is not limited to, the 

following smelting processes: sintering reduction, preliminary 

treatment, and refining operations. The sintering process 

includes an updraft or downdraft sintering machine. The 

reduction process includes the blast furnace, electric smelting 

furnace with a converter or reverberatory furnace, and slag 

fuming furnace process units. The preliminary treatment process 

includes the drossing kettles and dross reverberatory furnace 

process units. The refining process includes the refinery 

process unit”. The definition is clear that the primary intent 

was to cover sources that produce lead metal from ore 

concentrates, which would “include” the use of a 

pyrometallurgical process, but would not be limited to such. As 

noted previously, at the time we promulgated the MACT standard, 

the only method of producing lead metal from ore concentrates 

was through use of pyrometallurgical techniques and we adopted 

an applicability provision that focused on that process. 

However, information provided by the sole operating primary lead 
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smelting facility indicates that lead production is likely to 

continue at the current Doe Run facility, although using a 

process other than a pyrometallurgical technique. The new lead 

facility would continue to process lead ore concentrate in order 

to produce lead metal. Based on the current applicability 

section and definitions, it could be interpreted that the future 

lead producing process, using techniques other than 

pyrometallurgical, would not be subject to the NESHAP for 

primary lead smelters. Such a limited interpretation is not 

consistent with EPA’s intent as evidenced by the broader 

definition in the source category list. Therefore, EPA is 

proposing to amend the applicability section to specify that the 

MACT applies to any lead processing facility that produces lead 

metal from lead ore concentrate. Consistent with the proposed 

revision to the applicability section, we are proposing to 

remove the definition of “primary lead smelter” and add a 

definition of “primary lead processor” which means any facility 

engaged in the production of lead metal from lead sulfide ore 

concentrates through the use of pyrometallurgical or other 

techniques. In addition, we are proposing to replace “primary 

lead smelter” with “primary lead processor” throughout 40 CFR 

subpart TTT. (§63.1541 through §63.1545, §63.1547 through 

§63.1549). We are specifically asking for comment on this 

proposed change in the definition. 
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Because there is only one primary lead processing facility 

in the US, there will be no impact of this change on the number 

of existing facilities covered by the MACT. 

We note, however, that although we are changing the 

applicability section to clarify that the MACT applies to all 

processes for producing lead metal from ore concentrates, we are 

not today proposing a specific MACT standard that would apply to 

the as-yet undemonstrated hydrometallurgical process which Doe 

Run has indicated that it plans to build at the current Doe Run 

facility. If and when that process begins operation, we will 

consider whether to revise the MACT standard to specifically 

address that process or any other new processes. However, the 

limits applicable to specific emission sources currently in 

operation as specified in the MACT and as revised under CAA 

sections 112(d)(6) and (f)(2) in this rulemaking would continue 

to apply to any emission source at the facility that continues 

in operation, such as the refinery. In addition, to the extent 

that we establish a final air lead concentration limit as 

proposed in Section 63.1544, those limits would also continue to 

apply to the facility. We also are proposing that the plantwide emission limit we are proposing today should continue to 

apply to any facility that meets the revised applicability 

definition, but we are specifically soliciting comment on 

whether it should apply. 
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We are also taking this opportunity to clarify the 

reference to “lead refiners” in the second sentence of the 

applicability section, which provides that the MACT standard 

does not apply to “secondary lead smelters, lead refiners, or 

lead remelters.” The intent of this provision was to make clear 

that secondary lead smelters would not be subject to the rule 

because secondary lead smelters were listed as a separate source 

category and addressed in a separate MACT standard. With regard 

to lead refiners and lead remelters, the intent was to provide 

that these activities, to the extent that they are not located 

at facilities that produce lead from lead ore concentrate, would 

not be subject to the Primary Lead Smelting MACT. However, it 

was not the intention of the rule to exempt kettle refining 

operations included as part of a primary lead processing 

facility. Therefore, EPA is proposing to add definitions for 

secondary lead smelters, lead refiners, and lead remelters in 

the definitions section of this NESHAP in order to further 

clarify the exemption in the applicability provisions with 

regard to these types of facilities. As this change only 

clarifies an existing provision in the rule, there will be no 

impact to the number of facilities covered by the rule. 

4. Other Changes

The following lists additional minor changes we are 

proposing. This list includes rule changes that address 
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editorial errors and plain language revisions. 

 As part of EPA’s effort to incorporate plain language into its 

regulations, replaced the word “shall” with “must.” (§63.1543 

through §63.1550) 

 Correction to the original rule (“thru” replaced with 

“through” in the definition of “tapping location”). (§63.1542) 

 Minor wording change to definition of “fugitive dust source” 

to clarify meaning. (§63.1542) 

IV. Analyses Performed and Background of the Source Category and 

MACT Standard 

 As discussed above, in this notice we are proposing action 

to address the RTR requirements of CAA sections 112(d)(6) and 

(f)(2) for the Primary Lead Smelting MACT standard. In this 

section, we describe the analyses performed to support the 

proposed decisions for the RTR for this source category and we 

also include background information on the source category and 

the MACT standard. 

A. How did we estimate risks posed by the source category?

 The EPA conducted a risk assessment that provided estimates 

of the MIR posed by the HAP emissions from the one source in the 

source category, the distribution of cancer risks within the 

exposed populations, cancer incidence, HI for chronic exposures 

to HAP with the potential to cause non-cancer health effects, 
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hazard quotients (HQ) for acute exposures to HAP with the 

potential to cause non-cancer health effects, and an evaluation 

of the potential for adverse environmental effects. The risk 

assessments consisted of seven primary steps, as discussed 

below. 

The docket for this rulemaking contains the following 

document which provides more information on the risk assessment 

inputs and models: Draft Residual Risk Assessment for the 

Primary Lead Smelting Source Category. 

1. Establishing the Nature and Magnitude of Actual 

Emissions and Identifying the Emissions Release 

Characteristics. 

For the Primary Lead Smelting source category, we compiled 

a preliminary dataset using readily available information, 

reviewed the data, and made changes where necessary. The 

preliminary dataset was based on data in the 2002 National 

Emissions Inventory (NEI) Final Inventory, Version 1 (made 

publicly available on February 26, 2006). The NEI is a database 

that contains information about sources that emit criteria air 

pollutants, their precursors, and HAP. The NEI database 

includes estimates of annual air pollutant emissions from point, 

non-point, and mobile sources in the 50 States, the District of 

Columbia, Puerto Rico, and the Virgin Islands. The EPA collects 
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this information and releases an updated version of the NEI 

database every 3 years. 

On December 4, 2009, a CAA Section 114 Information 

Collection Request (ICR) was issued requesting information from 

the one facility in this source category. An updated dataset 

was created through incorporation of changes to the dataset from 

the ICR data review process and additional information gathered 

by EPA. The updated dataset contains information for the one 

facility in the source category and was used to conduct the risk 

assessment and other analyses that form the basis for the 

proposed risk and technology reviews. A copy of the dataset 

used and documentation of the risk assessment can be found in 

the docket. 

2. Establishing the Relationship between Actual Emissions 

and MACT-Allowable Emissions Levels. 

The available emissions data in the NEI and from other 

sources typically represent the estimates of mass of emissions 

actually emitted during the specified annual time period. These 

“actual” emission levels are often lower than the emission 

levels that a facility might be allowed to emit and still comply 

with the MACT standards. The emissions level allowed to be 

emitted by the MACT standards is referred to as the “MACTallowable” emissions level. This represents the highest 
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emissions level that could be emitted by the facility without 

violating the MACT standards. 

We discussed the use of both MACT-allowable and actual 

emissions in the final Coke Oven Batteries residual risk rule 

(70 FR 19998–19999, April 15, 2005) and in the proposed and 

final Hazardous Organic NESHAP (HON) residual risk rules (71 FR 

34428, June 14, 2006, and 71 FR 76609, December 21, 2006, 

respectively). In those previous actions, we noted that 

assessing the risks at the MACT-allowable level is inherently 

reasonable since these risks reflect the maximum level sources 

could emit and still comply with national emission standards. 

But we also explained that it is reasonable to consider actual 

emissions, where such data are available, in both steps of the 

risk analysis, in accordance with the Benzene NESHAP. (54 FR 

38044, September 14, 1989.) It is reasonable to consider actual 

emissions because sources typically seek to perform better than 

required by emission standards to provide an operational cushion 

to accommodate the variability in manufacturing processes and 

control device performance. 

As described above, the actual emissions data were compiled 

based on the NEI, information gathered from the facility and 

State, and information received in response to the ICR. To 

estimate emissions at the MACT-allowable level, we developed a 

ratio of MACT-allowable to actual emissions for each source type 
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(i.e., the individual stacks and the aggregate fugitive 

emissions) for the one facility in the source category. This 

ratio is based on the level of control required by the MACT 

standards compared to the level of reported actual emissions and 

available information on the level of control achieved by the 

emissions controls in use. For example, if there was 

information to suggest that a emission point type was being 

controlled by 98 percent while the MACT standards required only 

92 percent control, we would estimate that MACT-allowable 

emissions from that emission point type could be as much as 4 

times higher (8 percent allowable emissions compared with 2 

percent actually emitted), and the ratio of MACT-allowable to 

actual would be 4:1 for this emission point type. After 

developing these ratios for each emission point type at the one 

facility in this source category, we next applied these ratios 

to the maximum chronic risk estimates from the inhalation risk 

assessment to obtain maximum risk estimates based on MACTallowable emissions. The estimate of MACT-allowable emissions 

for the Primary Lead Smelting source category is described in 

section V of this preamble. 

3. Conducting Dispersion Modeling, Determining Inhalation 

Exposures, and Estimating Individual and Population Inhalation 

Risks. 
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Both long-term and short-term inhalation exposure 

concentrations and health risks from the source category 

addressed in this proposal were estimated using the Human 

Exposure Model (Community and Sector HEM–3 version 1.1.0). The 

HEM–3 performs three of the primary risk assessment activities 

listed above: (1) conducting dispersion modeling to estimate 

the concentrations of HAP in ambient air, (2) estimating longterm and short-term inhalation exposures to individuals residing 

within 50 km of the modeled sources, and (3) estimating 

individual and population-level inhalation risks using the 

exposure estimates and quantitative dose-response information. 

The dispersion model used by HEM–3 is AERMOD, which is one 

of EPA’s preferred models for assessing pollutant concentrations 

from industrial facilities.6

 To perform the dispersion modeling 

and to develop the preliminary risk estimates, HEM–3 draws on 

three data libraries. The first is a library of meteorological 

data, which is used for dispersion calculations. This library 

includes 1 year of hourly surface and upper air observations for 

130 meteorological stations, selected to provide coverage of the 

United States and Puerto Rico. However, in this instance, sitespecific meteorological data for the one facility in this source 

category were supplied by the state of Missouri and used for the 

 

6

 U.S. EPA. Revision to the Guideline on Air Quality Models: Adoption 

of a Preferred General Purpose (Flat and Complex Terrain) Dispersion 

Model and Other Revisions (70 FR 68218, November 9, 2005).
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modeling. The data provided by the state of Missouri were for 

eight quarters (i.e., eight three-month periods) from April 1997 

through June 1999. To obtain one year of meteorological data, 

we used the middle portion of these data, the year 1998, in our 

modeling. A second library of United States Census Bureau 

census block7

 internal point locations and populations provides 

the basis of human exposure calculations (Census, 2000). In 

addition, for each census block, the census library includes the 

elevation and controlling hill height, which are also used in 

dispersion calculations. A third library of pollutant unit risk 

factors and other health benchmarks is used to estimate health 

risks. These risk factors and health benchmarks are the latest 

values recommended by EPA for HAP and other toxic air 

pollutants. These values are available at 

http://www.epa.gov/ttn/atw/toxsource/summary.html and are 

discussed in more detail later in this section. 

In developing the risk assessment for chronic exposures, we 

used the estimated annual average ambient air concentration of 

each of the HAP emitted by each source for which we have 

emissions data in the source category. The air concentrations 

at each nearby census block centroid were used as a surrogate 

for the chronic inhalation exposure concentration for all the 

 

7

 A census block is generally the smallest geographic area for which 

census statistics are tabulated. 
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people who reside in that census block. We calculated the MIR 

for the one facility as the cancer risk associated with a 

lifetime (70-year period) of exposure to the maximum 

concentration at the centroid of an inhabited census block. 

Individual cancer risks were calculated by multiplying the 

estimated lifetime exposure to the ambient concentration of each 

of the HAP (in micrograms per cubic meter) by its Unit Risk 

Estimate (URE), which is an upper bound estimate of an 

individual’s probability of contracting cancer over a lifetime 

of exposure to a concentration of 1 microgram of the pollutant 

per cubic meter of air. In general, for residual risk 

assessments, we use URE values from EPA’s Integrated Risk 

Information System (IRIS). For carcinogenic pollutants without 

EPA IRIS values, we look to other reputable sources of cancer 

dose-response values, often using California Environmental 

Protection Agency (CalEPA) URE values, where available. In 

cases where new, scientifically credible dose response values 

have been developed in a manner consistent with EPA guidelines 

and have undergone a peer review process similar to that used by 

EPA, we may use such dose-response values in place of, or in 

addition to, other values, if appropriate. In this review, IRIS 

values were available for both carcinogenic pollutants (cadmium 

and arsenic) emitted by the facility in this source category, 

and therefore IRIS values were used in the assessment. 
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 Incremental individual lifetime cancer risks associated 

with emissions from the one source in the source category were 

estimated as the sum of the risks for each of the carcinogenic 

HAP (including those classified as carcinogenic to humans, 

likely to be carcinogenic to humans, and suggestive evidence of 

carcinogenic potential8

) emitted by the modeled source. Cancer 

incidence and the distribution of individual cancer risks for 

the population within 50 km of the source were also estimated 

for the source category as part of these assessments by summing 

individual risks. A distance of 50 km is consistent with both 

the analysis supporting the 1989 Benzene NESHAP (54 FR 38044) 

and the limitations of Gaussian dispersion models, including 

AERMOD. 

To assess risk of non-cancer health effects from chronic 

exposures, we summed the HQ for each of the HAP that affects a 

common target organ system to obtain the HI for that target 

organ system (or target organ-specific HI, TOSHI). The HQ is 

the estimated exposure divided by the chronic reference value, 

 

8 These classifications also coincide with the terms "known carcinogen, 

probable carcinogen, and possible carcinogen," respectively, which are 

the terms advocated in the EPA's previous Guidelines for Carcinogen 

Risk Assessment, published in 1986 (51 FR 33992, September 24, 1986). 

Summing the risks of these individual compounds to obtain the 

cumulative cancer risks is an approach that was recommended by the 

EPA's SAB in their 2002 peer review of EPA's NATA entitled, NATA -

Evaluating the National-scale Air Toxics Assessment 1996 Data -- an 

SAB Advisory, available at: 

http://yosemite.epa.gov/sab/sabproduct.nsf/214C6E915BB04E14852570CA007

A682C/$File/ecadv02001.pdf.
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which is either the EPA RfC, defined as “an estimate (with 

uncertainty spanning perhaps an order of magnitude) of a 

continuous inhalation exposure to the human population 

(including sensitive subgroups) that is likely to be without an 

appreciable risk of deleterious effects during a lifetime,” or, 

in cases where an RfC is not available, the Agency for Toxic 

Substances and Disease Registry (ATSDR) chronic Minimal Risk 

Level (MRL) or the CalEPA Chronic Reference Exposure Level 

(REL). The REL is defined as “the concentration level at or 

below which no adverse health effects are anticipated for a 

specified exposure duration.” 

Screening estimates of acute exposures and risks were also 

evaluated for each of the HAP at the point of highest off-site 

exposure for each facility (i.e., not just the census block 

centroids) assuming that a person was located at this spot at a 

time when both the peak (hourly) emission rate and hourly 

dispersion conditions occurred. In general, acute HQ values 

were calculated using best available, short-term dose-response 

value. These acute dose-response values include REL, Acute 

Exposure Guideline Levels (AEGL), and Emergency Response 

Planning Guidelines (ERPG) for 1-hour exposure durations. 

Notably, for HAP emitted from this source category, REL values 

were the only such dose-response values available. As discussed 
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below, we used conservative assumptions for emission rates, 

meteorology, and exposure location for our acute analysis. 

As described in the CalEPA’s Air Toxics Hot Spots Program 

Risk Assessment Guidelines, Part I, The Determination of Acute 

Reference Exposure Levels for Airborne Toxicants, an acute REL 

value (http://www.oehha.ca.gov/air/pdf/acuterel.pdf) is defined 

as “the concentration level at or below which no adverse health 

effects are anticipated for a specified exposure duration is 

termed the REL. REL values are based on the most sensitive, 

relevant, adverse health effect reported in the medical and 

toxicological literature. REL values are designed to protect 

the most sensitive individuals in the population by the 

inclusion of margins of safety. Since margins of safety are 

incorporated to address data gaps and uncertainties, exceeding 

the REL does not automatically indicate an adverse health 

impact. 

To develop screening estimates of acute exposures, we first 

developed estimates of maximum hourly emission rates by 

multiplying the average actual annual hourly emission rates by a 

factor to cover routinely variable emissions. We chose the 

factor to use based on process knowledge and engineering 

judgment and with awareness of a Texas study of short-term 

emissions variability, which showed that most peak emission 

events, in a heavily-industrialized 4-county area (Harris, 
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Galveston, Chambers, and Brazoria Counties, Texas) were less 

than twice the annual average hourly emission rate. The highest 

peak emission event was 74 times the annual average hourly 

emission rate, and the 99th percentile ratio of peak hourly 

emission rate to the annual average hourly emission rate was 9.9

 

This analysis is provided in Appendix 4 of the Draft Residual 

Risk Assessment for Primary Lead Smelting which is available in 

the docket for this action. Considering this analysis, unless 

specific process knowledge or data are available to provide an 

alternate value, to account for more than 99 percent of the peak 

hourly emissions, we apply a conservative screening 

multiplication factor of 10 to the average annual hourly 

emission rate in these acute exposure screening assessments. 

For the Primary Lead Smelting source category, this factor of 10 

was applied. 

In cases where all acute HQ values from the screening step 

were less than or equal to 1, acute impacts were deemed 

negligible and no further analysis was performed. In the cases 

where an acute HQ from the screening step was greater than 1, 

additional site-specific data were considered to develop a more 

refined estimate of the potential for acute impacts of concern. 

Ideally, we would prefer to have continuous measurements over 

 

9 See http://www.tceq.state.tx.us/compliance/field_ops/eer/index.html 

or docket to access the source of these data.
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time to see how the emissions vary by each hour over an entire 

year. Having a frequency distribution of hourly emission rates 

over a year would allow us to perform a probabilistic analysis 

to estimate potential threshold exceedances and their frequency 

of occurrence. Such an evaluation could include a more complete 

statistical treatment of the key parameters and elements adopted 

in this screening analysis. However, we recognize that having 

this level of data is rare, hence our use of the multiplier 

(i.e., factor of 10) approach in our screening analysis. 

4. Conducting Multipathway Exposure and Risk Modeling. 

The potential for significant human health risks due to 

exposures via routes other than inhalation (i.e., multipathway 

exposures) and the potential for adverse environmental impacts 

were evaluated in a three-step process. In the first step, we 

determined whether any facilities emitted any HAP known to be 

persistent and bio-accumulative in the environment (PB-HAP). 

There are 14 PB-HAP compounds or compound classes identified for 

this screening in EPA’s Air Toxics Risk Assessment Library

(available at http://www.epa.gov/ttn/fera/risk_atra_vol1.html). 

They are cadmium compounds, chlordane, chlorinated 

dibenzodioxins and furans, dichlorodiphenyldichloroethylene, 

heptachlor, hexachlorobenzene, hexachlorocyclohexane, lead 

compounds, mercury compounds, methoxychlor, polychlorinated 

biphenyls, POM, toxaphene, and trifluralin. Emissions of two PB 
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HAP were identified in the emissions inventory for the Primary 

Lead Smelting source category: lead compounds and cadmium 

compounds. 

Cadmium emissions were evaluated for potential noninhalation risks and adverse environmental impacts using our 

recently developed screening scenario that was developed for use 

with the TRIM.FaTE model. This screening scenario uses 

environmental media outputs from the peer-reviewed TRIM.FaTE to 

estimate the maximum potential ingestion risks for any specified 

emission scenario by using a generic farming/fishing exposure 

scenario that simulates a subsistence environment. The 

screening scenario retains many of the ingestion and scenario 

inputs developed for EPA’s Human Health Risk Assessment 

Protocols (HHRAP) for hazardous waste combustion facilities. 

In the development of the screening scenario a sensitivity 

analysis was conducted to ensure that its key design parameters 

were established such that environmental media concentrations 

were not underestimated, and to also minimize the occurrence of 

false positives for human health endpoints. See Appendix 3 of 

the risk assessment document for a complete discussion of the 

development and testing of the screening scenario, as well as 

for the values of facility-level de minimis emission rates 

developed for screening potentially significant multi-pathway 

impacts. For the purpose of developing de minimis emission 
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rates for our cadmium multi-pathway screening, we derived 

emission levels for cadmium at which the maximum human health 

risk would be 1-in-1 million for lifetime cancer risk. 

In evaluating the potential air-related multi-pathway risks 

from the emissions of lead compounds from the one facility in 

this source category, rather than developing a de minimis

emission rate, we compared its maximum modeled 3-month average 

atmospheric lead concentration at any off-site location with the 

current primary National Ambient Air Quality Standard (NAAQS) 

for lead (promulgated in 2008), which is set to a level of 0.15 

μg/m3

 based on a rolling 3-month period with a not-to-be-exceeded 

form, and which will require attainment by 2016. 73 FR 66964. 

Notably, in making these comparisons, we estimated maximum 

rolling 3-month ambient lead concentrations taking into account 

all of the elements of the NAAQS for lead. That is, our 

estimated 3-month lead concentrations are calculated in a manner 

that is consistent with the indicator, averaging time, and form 

of the NAAQS for lead, and those estimates are compared to the 

actual level of the lead NAAQS (0.15 μg/m3). 

The NAAQS value, a public health policy judgment,

incorporated the agencies Agency’s most recent health evaluation 

of air effects of lead exposure, as well as public health policy 

judgment, for the purposes of setting a national standard. In 

setting this value, the Administrator promulgated a standard 

Formatted: Not Highlight
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that was requisite to protect public health with an adequate 

margin of safety. We consider values below the level of the 

primary NAAQS to protect against multi-pathway risks because as 

mentioned above, the primary NAAQS is set as to protect public 

health with an adequate margin of safety. However, ambient air 

lead concentrations above the NAAQS are considered to pose the 

potential for increased risk to public health. We consider 

this NAAQS assessment to be a refined analysis given the 

numerous health studies, detailed risk and exposure analyses, 

and level of external peer and public review that went into the 

development of the primary NAAQS for lead, combined with the 

site-specific dispersion modeling analysis performed to develop 

the ambient concentration estimates due to emissions from the 

one Primary Lead Processing facility being addressed in this 

RTR. It should be noted, however, that this comparison does not 

account for possible population exposures to lead from sources 

other than the one being modeled; for example, via consumption 

of water from untreated local sources or ingestion of locally 

grown food. Nevertheless, the Administrator judged that such a 

standard, would protect, with an adequate margin of safety, the 

health of children and other at-risk populations against an 

array of adverse health effects, most notably including 

neurological effects, particularly neurobehavioral and 

neurocognitive effects, in children. (73 FR 67007). The 

Formatted: Not Highlight

Formatted: Not Highlight
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Administrator, in setting the standard, also recognized that no 

evidence-or risk based bright line indicated a single 

appropriate level. Instead a collection of scientific evidence 

and other information was used to select the standard from a 

range of reasonable values (73 FR 67006). 

We further note that comparing ambient lead concentrations 

to the NAAQS for lead, considering the level, averaging time, 

form and indicator, also informs whether there is the potential 

for adverse environmental effects. This is because the 

secondary lead NAAQS, which has the same averaging time, form, 

and level as the primary standard, was set to protect the public 

welfare which includes among other things soils, water, crops, 

vegetation and wildlife. CAA section 302(h). Thus, ambient lead 

concentrations above the NAAQS for lead also indicate the 

potential for adverse environmental effects. 

For additional information on the multi-pathway analysis 

approach, see the residual risk documentation as referenced in 

section IV.A of this preamble. The EPA solicits comment 

generally on the modeling approach used herein to assess airrelated lead risks, and specifically on the use of the lead 

NAAQS in this analytical construct.

5. Assessing Risks Considering Emissions Control Options. 

 In addition to assessing baseline inhalation risks and 

screening for potential multi-pathway risks, we also estimated 
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risks considering the potential emission reductions that would 

be achieved by the particular control options under 

consideration. The expected emissions reductions were applied 

to the specific HAP and emissions points in the source category 

dataset to develop corresponding estimates of risk reductions. 

6. Conducting Other Risk-Related Analyses, Including 

Facility-Wide Assessments and Demographic Analyses. 

a. Facility-Wide Risk. 

To put the source category risks in context, for our 

residual risk review, we also examine the risks from the entire 

“facility,” where the facility includes all HAP-emitting 

operations within a contiguous area and under common control. 

In other words, we examine the HAP emissions not only from the 

source category of interest, but also emissions of HAP from all 

other emission sources at the facility. In this rulemaking, for 

the sole facility in the Primary Lead Smelting source category, 

there are no other significant HAP emission sources present. 

With the exception of organic HAP sources determined to present 

insignificant risk, all HAP sources have been included in the 

risk analysis. Therefore, the facility-wide risks are the same 

as the source category risk and no separate facility-wide 

analysis was necessary. 

b. Demographic Analysis. 
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To examine the potential for any environmental justice 

issues that might be associated with HAP emissions with this 

source category, we evaluated the distributions of HAP-related 

cancer and non-cancer risks across different social, 

demographic, and economic groups within the populations living 

near the one facility in this source category. The development 

of demographic analyses to inform the consideration of 

environmental justice issues in EPA rulemakings is evolving. 

EPA offers the demographic analyses in this rulemaking to inform 

the consideration of potential environmental justice issues, and 

invites public comment on the approaches used and the 

interpretations made from the results, with the hope that this 

will support the refinement and improve the utility of such 

analyses for future rulemakings. 

For the demographic analyses, we focus on the populations 

within 50 km of any facility with emission sources subject to 

the MACT standard (identical to the risk assessment). Based on 

the emissions for the source category or the facility, we then 

identified the populations that are estimated to have exposures 

to HAP which result in: 1) cancer risks of 1-in-1 million or 

greater, 2) non-cancer HI of 1 or greater, and/or 3) ambient 

lead concentrations above the level of the NAAQS for lead. We 

compare the percentages of particular demographic groups within 

the focused populations to the total percentages of those 
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demographic groups nationwide. The results, including other 

risk metrics, such as average risks for the exposed populations, 

are documented in a technical report in the docket for the 

source category covered in this proposal.10 

The basis for the risk values used in the demographic 

analyses for the one facility subject to the Primary Lead 

Smelting MACT was the modeling results based on actual emissions 

levels obtained from the HEM-3 model described above. The risk 

values for each census block were linked to a database of 

information from the 2000 decennial census that includes data on 

race and ethnicity, age distributions, poverty status, household 

incomes, and education level. The Census Department Landview®

database was the source of the data on race and ethnicity, and 

the data on age distributions, poverty status, household 

incomes, and education level were obtained from the 2000 Census 

of Population and Housing Summary File 3 (SF3) Long Form. While 

race and ethnicity census data are available at the census block 

level, the age and income census data are only available at the 

census block group level (which includes an average of 26 blocks 

or an average of 1,350 people). Where census data are available 

at the block group level but not the block level, we assumed 

 

10 Risk and Technology Review – Analysis of Socio-Economic Factors for 

Populations Living Near Primary Lead Smelting Operations.
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that all census blocks within the block group have the same 

distribution of ages and incomes as the block group. 

We focused the analysis on those census blocks where source 

category risk results show either estimated lifetime inhalation 

cancer risks above 1-in-1 million or chronic non-cancer indices 

above 1. In addition, in this case we also focused on those 

census blocks where estimated ambient lead concentrations were 

above the level of the lead NAAQS. For each of these cases, we 

determined the relative percentage of different racial and 

ethnic groups, different age groups, adults with and without a 

high school diploma, people living in households below the 

national median income, and for people living below the poverty 

line within those census blocks. The specific census population 

categories included: 

• Total population; 

• White; 

• African American (or Black); 

• Native Americans; 

• Other races and multiracial; 

• Hispanic or Latino; 

• People living below the poverty line; 

• Children 18 years of age and under; 

• Adults 19 to 64 years of age; 

• Adults 65 years of age and over; 
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• Adults without a high school diploma. 

It should be noted that these categories overlap in some 

instances, resulting in some populations being counted in more 

than one category (e.g., other races and multiracial and 

Hispanic). In addition, while not a specific census population 

category, we also examined risks to “Minorities,” a 

classification which is defined for these purposes as all race 

population categories except white. 

The methodology and the results of the demographic analyses 

for this source category are included in the technical report 

available in the docket for this action. (Risk and Technology 

Review – Analysis of Socio-Economic Factors for Populations 

Living Near Primary Lead Smelting Operations). 

7. Considering Uncertainties in Risk Assessment.

Uncertainty and the potential for bias are inherent in all 

risk assessments, including that performed for the source 

category addressed in this proposal. Although uncertainty 

exists, we believe the approach that we took, which used 

conservative tools and assumptions, ensures that our decisions 

are health-protective. A brief discussion of the uncertainties 

in the emissions dataset, dispersion modeling, inhalation 

exposure estimates, and dose-response relationships follows 

below. A more thorough discussion of these uncertainties is 

included in the risk assessment documentation (Draft Residual 
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Risk Assessment for Primary Lead Smelting) available in the 

docket for this action. 

a. Uncertainties in the Emissions Dataset. 

Although the development of the RTR dataset involved 

quality assurance/quality control processes, the accuracy of 

emissions values will vary depending on the source of the data, 

the degree to which data are incomplete or missing, the degree 

to which assumptions made to complete the datasets are accurate, 

whether and to what extent errors were made in estimating 

emissions values, and other factors. The emission estimates 

considered in this analysis are annual totals provided by the 

facility that do not reflect short-term fluctuations during the 

course of a year or variations from year to year. In contrast, 

the estimates of peak hourly emission rates for the acute 

effects screening assessment were based on multiplication 

factors applied to the average annual hourly emission rates (the 

default factor of 10 was used for Primary Lead Smelting), which 

is intended to account for emission fluctuations due to normal 

facility operations. 

b. Uncertainties in Dispersion Modeling. 

While the analysis employed EPA’s recommended regulatory 

dispersion model, AERMOD, we recognize that there is uncertainty 

in ambient concentration estimates associated with any model, 

including AERMOD. In circumstances where we had to choose 
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between various model options, where possible, we selected model 

options (e.g., rural/urban, plume depletion, chemistry) that 

provided an overestimate of ambient concentrations of the HAP 

rather than an underestimate. However, because of practicality 

and data limitation reasons, some factors (e.g., building 

downwash) have the potential in some situations to overestimate 

or underestimate ambient impacts. Despite these uncertainties, 

we believe that at off-site locations and census block 

centroids, the approach considered in the dispersion modeling 

analysis should generally yield overestimates of ambient HAP 

concentrations. 

c. Uncertainties in Inhalation Exposure. 

The effects of human mobility on exposures were not 

included in the assessment. Specifically, short-term mobility 

and long-term mobility between census blocks in the modeling 

domain were not considered.11 As a result, this simplification 

will likely bias the assessment toward overestimating the 

highest exposures. In addition, the assessment predicted the 

chronic exposures at the centroid of each populated census block 

as surrogates for the exposure concentrations for all people 

living in that block. Using the census block centroid to 

predict chronic exposures tends to over-predict exposures for 

 

11 Short-term mobility is movement from one microenvironment to another 

over the course of hours or days. Long-term mobility is movement from 

one residence to another over the course of a lifetime.
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people in the census block who live farther from the facility, 

and under-predict exposures for people in the census block who 

live closer to the facility. Thus, using the census block 

centroid to predict chronic exposures may lead to a potential 

understatement or overstatement of the true maximum impact for 

any one individual, but is an unbiased estimate of average risk 

and incidence. 

The assessments evaluate the projected cancer inhalation 

risks associated with pollutant exposures over a 70-year period, 

which is the assumed lifetime of an individual. In reality, 

both the length of time that modeled emissions sources at 

facilities actually operate (i.e., more or less than 70 years), 

and the domestic growth or decline of the modeled industry 

(i.e., the increase or decrease in the number or size of United 

States facilities), will influence the future risks posed by a 

given source or source category. Depending on the 

characteristics of the industry, these factors will, in most 

cases, result in an overestimate both in individual risk levels 

and in the total estimated number of cancer cases. However, in 

rare cases, where a facility maintains or increases its emission 

levels beyond 70 years, residents live beyond 70 years at the 

same location, and the residents spend most of their days at 

that location, then the risks could potentially be 

underestimated. Annual cancer incidence estimates from 
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exposures to emissions from these sources would not be affected 

by uncertainty in the length of time emissions sources operate. 

For the specific source in this source category we anticipate 

significant reduction in activities and emissions in the 

relatively near future. If this happens, chronic risks based on 

the continuation of current emission levels will be over 

estimated. 

The exposure estimates used in these analyses assume 

chronic exposures to ambient levels of pollutants. Because most 

people spend the majority of their time indoors, actual 

exposures may not be as high, depending on the characteristics 

of the pollutants modeled. For many of the HAP, indoor levels 

are roughly equivalent to ambient levels, but for very reactive 

pollutants or larger particles, these levels are typically 

lower. This factor has the potential to result in an 

overstatement of 25 to 30 percent of exposures.12 

In addition to the uncertainties highlighted above, there 

are several factors specific to the acute exposure assessment 

that should be highlighted. The accuracy of an acute inhalation 

exposure assessment depends on the simultaneous occurrence of 

independent factors that may vary greatly, such as hourly 

emissions rates, meteorology, and human activity patterns. In 

 

12 U.S. EPA. National-Scale Air Toxics Assessment for 1996. (EPA 

453/R–01–003; January 2001; page 85.)
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this assessment, we assume that individuals remain for 1 hour at 

the point of maximum ambient concentration as determined by the 

co-occurrence of peak emissions and worst-case meteorological 

conditions. These assumptions would tend to overestimate actual 

exposures since it is unlikely that a person would be located at 

the point of maximum exposure during the time of worst-case 

impact. 

d. Uncertainties in Dose-Response Relationships. 

There are uncertainties inherent in the development of the 

dose-response values used in our risk assessments for cancer 

effects from chronic exposures and non-cancer effects from both 

chronic and acute exposures. Some uncertainties may be 

considered quantitatively, and others generally are expressed in 

qualitative terms. We note as a preface to this discussion a 

point on dose-response uncertainty that is brought out in EPA’s 

2005 Cancer Guidelines; namely, that “the primary goal of EPA 

actions is protection of human health; accordingly, as an Agency 

policy, risk assessment procedures, including default options 

that are used in the absence of scientific data to the contrary, 

should be health protective.” (EPA 2005 Cancer Guidelines, 

pages 1–7.) This is the approach followed here as summarized in 

the next several paragraphs. A complete detailed discussion of 

uncertainties and variabilities in dose-response relationships 
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is given in the residual risk documentation which is available 

in the docket for this action. 

Cancer URE values used in our risk assessments are those 

that have been developed to generally provide an upper bound 

estimate of risk. That is, they represent a “plausible upper 

limit to the true value of a quantity” (although this is usually 

not a true statistical confidence limit).13 In some 

circumstances, the true risk could be as low as zero; however, 

in other circumstances the risk could be greater.14 When 

developing an upper bound estimate of risk and to provide risk 

values that do not underestimate risk, health-protective default 

approaches are generally used. To err on the side of ensuring 

adequate health-protection, EPA typically uses the upper bound 

estimates rather than lower bound or central tendency estimates 

in our risk assessments, an approach that may have limitations 

for other uses (e.g., priority-setting or expected benefits 

analysis). 

Chronic non-cancer reference (RfC and RfD) values represent 

chronic exposure levels that are intended to be healthprotective levels. Specifically, these values provide an 

estimate (with uncertainty spanning perhaps an order of 

 

13 IRIS glossary (http://www.epa.gov/NCEA/iris/help_gloss.htm). 14 An exception to this is the URE for benzene, which is considered to 

cover a range of values, each end of which is considered to be equally 

plausible, and which is based on maximum likelihood estimates.
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magnitude) of a continuous inhalation exposure (RfC) or a daily 

oral exposure (RfD) to the human population (including sensitive 

subgroups) that is likely to be without an appreciable risk of 

deleterious effects during a lifetime. To derive values that 

are intended to be “without appreciable risk,” the methodology 

relies upon an uncertainty factor (UF) approach (U.S. EPA, 1993, 

1994) which includes consideration of both uncertainty and 

variability. When there are gaps in the available information, 

UF are applied to derive reference values that are intended to 

protect against appreciable risk of deleterious effects. The UF 

are commonly default values,15 e.g., factors of 10 or 3, used in 

the absence of compound-specific data; where data are available, 

UF may also be developed using compound-specific information. 

When data are limited, more assumptions are needed and more UF 

are used. Thus, there may be a greater tendency to overestimate 

 

15 According to the NRC report, Science and Judgment in Risk Assessment

(NRC, 1994) “[Default] options are generic approaches, based on 

general scientific knowledge and policy judgment, that are applied to 

various elements of the risk assessment process when the correct 

scientific model is unknown or uncertain.” The 1983 NRC report, Risk 

Assessment in the Federal Government: Managing the Process, defined 

default option as “the option chosen on the basis of risk assessment 

policy that appears to be the best choice in the absence of data to 

the contrary” (NRC, 1983a, p. 63). Therefore, default options are not 

rules that bind the Agency; rather, the Agency may depart from them in 

evaluating the risks posed by a specific substance when it believes 

this to be appropriate. In keeping with EPA’s goal of protecting 

public health and the environment, default assumptions are used to 

ensure that risk to chemicals is not underestimated (although defaults 

are not intended to overtly overestimate risk). See EPA, 2004, An 

Examination of EPA Risk Assessment Principles and Practices, 

EPA/100/B–04/001 available at: 

http://www.epa.gov/osa/pdfs/ratf-final.pdf.
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risk in the sense that further study might support development 

of reference values that are higher (i.e., less potent) because 

fewer default assumptions are needed. However, for some 

pollutants, it is possible that risks may be underestimated. 

While collectively termed “UF,” these factors account for a 

number of different quantitative considerations when using 

observed animal (usually rodent) or human toxicity data in the 

development of the RfC. The UF are intended to account for: 

(1) variation in susceptibility among the members of the human 

population (i.e., inter-individual variability); (2) uncertainty 

in extrapolating from experimental animal data to humans (i.e., 

interspecies differences); (3) uncertainty in extrapolating from 

data obtained in a study with less-than-lifetime exposure (i.e., 

extrapolating from sub-chronic to chronic exposure); (4) 

uncertainty in extrapolating the observed data to obtain an 

estimate of the exposure associated with no adverse effects; and 

(5) uncertainty when the database is incomplete or there are 

problems with the applicability of available studies. Many of 

the UF used to account for variability and uncertainty in the 

development of acute reference values are quite similar to those 

developed for chronic durations, but they more often use 

individual UF values that may be less than 10. UF are applied 

based on chemical-specific or health effect-specific information 

(e.g., simple irritation effects do not vary appreciably between 
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human individuals, hence a value of 3 is typically used), or 

based on the purpose for the reference value (see the following 

paragraph). The UF applied in acute reference value derivation 

include: (1) Heterogeneity among humans; (2) uncertainty in 

extrapolating from animals to humans; (3) uncertainty in lowest 

observed adverse effect (exposure) level to no observed adverse 

effect (exposure) level adjustments; and (4) uncertainty in 

accounting for an incomplete database on toxic effects of 

potential concern. Additional adjustments are often applied to 

account for uncertainty in extrapolation from observations at 

one exposure duration (e.g., 4 hours) to derive an acute 

reference value at another exposure duration (e.g., 1 hour). 

As further discussed below, there is no RfD or other 

comparable chronic health benchmark value for lead compounds. 

Thus, to address multipathway human health and environmental 

risks associated with emissions of lead from this facility, 

ambient lead concentrations were compared to the NAAQS for lead. 

In developing the NAAQS for lead, EPA considered human health 

evidence reporting adverse health effects associated with lead 

exposure, as well as an EPA conducted multipathway risk 

assessment that applied models to estimate human exposures to 

air-related lead and the associated risk (73FR66979). EPA also 

explicitly considered the uncertainties associated with both the 

human health evidence and the exposure and risk analyses when 

Formatted: Not Highlight
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developing the NAAQS for lead. For example, EPA considered 

uncertainties in the relationship between ambient air lead and 

blood lead levels (73FR66974), as well as uncertainties between 

blood lead levels and loss of IQ points in children (73FR66981). 

In considering the evidence and risk analyses and their 

associated uncertainties, the EPA Administrator noted his view 

that there is no evidence- or risk-based bright line that 

indicates a single appropriate level. Instead, he noted, there 

is a collection of scientific evidence and judgments and other 

information, including information about the uncertainties 

inherent in many relevant factors, which needs to be considered 

together in making this public health policy judgment and in 

selecting a standard level from a range of reasonable values 

(73FR66998). In so doing, the Administrator decided that, a 

level for the primary lead standard of 0.15 μg/m3

, in combination 

with the specified choice of indicator, averaging time, and 

form, is requisite to protect public health, including the 

health of sensitive groups, with an adequate margin of safety 

(73FR67006). A thorough discussion of the health evidence, risk 

and exposure analyses, and their associated uncertainties can be 

found in EPA’s final rule revising the lead NAAQS (73 FR 66970-

66981, November 12, 2008). 

In 1988, EPA’s IRIS program reviewed the health effects 

data regarding lead and its inorganic compounds and determined 
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that it would be inappropriate to develop an RfD for these 

compounds, saying, “A great deal of information on the health 

effects of lead has been obtained through decades of medical 

observation and scientific research. This information has been 

assessed in the development of air and water quality criteria by 

the Agency's Office of Health and Environmental Assessment 

(OHEA) in support of regulatory decision-making by the Office of 

Air Quality Planning and Standards (OAQPS) and by the Office of 

Drinking Water (ODW). By comparison to most other environmental 

toxicants, the degree of uncertainty about the health effects of 

lead is quite low. It appears that some of these effects, 

particularly changes in the levels of certain blood enzymes and 

in aspects of children's neurobehavioral development, may occur 

at blood lead levels so low as to be essentially without a 

threshold. The Agency's RfD Work Group discussed inorganic lead 

(and lead compounds) at two meetings (07/08/1985 and 07/22/1985) 

and considered it inappropriate to develop an RfD for inorganic 

lead.” EPA’s IRIS assessment for Lead and compounds (inorganic) 

(CASRN 7439-92-1), http://www.epa.gov/iris/subst/0277.htm. 

We also note that because of the multi-pathway, multi-media 

impacts of lead, the risk assessment supporting the NAAQS 

considered direct inhalation exposures and indirect air-related 

multi-pathway exposures from industrial sources like primary and 

secondary lead smelting operations. It also considered 
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background lead exposures from other sources (like contaminated 

drinking water and exposure to lead-based paints). In revising 

the NAAQS for lead, we note that the Administrator placed more 

weight on the evidence-based framework and less weight on the 

results from the risk assessment, although he did find the risk 

estimates to be roughly consistent with and generally supportive 

of the evidence-based framework applied in the NAAQS 

determination (73FR67004). Thus, when revising the NAAQS for 

lead to protect public health with an adequate margin of safety, 

EPA considered both the evidence-based framework and the risk 

assessment, albeit to different extents. 

In addition to the uncertainties discussed above with 

respect to chronic, cancer, and the lead NAAQS reference values, 

there are also uncertainties associated with acute reference 

values. Not all acute reference values are developed for the 

same purpose, and care must be taken when interpreting the 

results of an acute assessment of human health effects relative 

to the reference value or values being exceeded. Where relevant 

to the estimated exposures, the lack of short-term dose-response 

values at different levels of severity should be factored into 

the risk characterization as potential uncertainties. 

Although every effort is made to identify peer-reviewed 

reference values for cancer and non-cancer effects for all 

pollutants emitted by the sources included in this assessment, 
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some hazardous air pollutants continue to have no peer-reviewed 

reference values for cancer or chronic non-cancer or acute 

effects. Since exposures to these pollutants cannot be included 

in a quantitative risk estimate, an understatement of risk for 

these pollutants at environmental exposure levels is possible. 

Additionally, chronic reference values for several of the 

compounds included in this assessment are currently under EPA 

IRIS review (e.g., cadmium and nickel), and revised assessments 

may determine that these pollutants are more or less potent than 

the current value. We may re-evaluate residual risks for the 

final rulemaking if, as a result of these reviews, a doseresponse metric changes enough to indicate that the risk 

assessment supporting this notice may significantly understate 

human health risk. 

e. Uncertainties in the Multipathway and Environmental 

Effects Assessment. 

 We generally assume that when exposure levels are not 

anticipated to adversely affect human health, they also are not 

anticipated to adversely affect the environment. For each 

source category, we generally rely on the site-specific levels 

of PB-HAP emissions to determine whether a full assessment of 

the multi-pathway and environmental effects is necessary. For 

PB-HAPS other than lead (i.e., cadmium), site-specific PB-HAP 

emission levels were far below levels which would trigger a 
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refined assessment of multi-pathway impacts, thus we are 

confident that these types of impacts are insignificant for the 

one facility in this source category. 

f. Uncertainties in the Facility-Wide Risk Assessment. 

We did not conduct a separate facility-wide risk assessment 

for this proposal because all of the HAP emission sources at the 

one facility subject to the MACT are covered by the MACT 

standard under review. Thus, the level of the facility-wide HAP 

emissions is the same as the level of emissions from the 

emissions sources subject to the MACT standard under review. 

g. Uncertainties in the Demographic Analysis. 

Our analysis of the distribution of risks across various 

demographic groups is subject to the typical uncertainties 

associated with census data (e.g., errors in filling out and 

transcribing census forms), as well as the additional 

uncertainties associated with the extrapolation of census-block 

group data (e.g., income level and education level) down to the 

census block level. 

B. How did we perform the technology review?

 Our technology review is focused on the identification and 

evaluation of developments in practices, processes, and control 

technologies. If a review of available information identifies 

such developments, then we conduct an analysis of the technical 

feasibility of these developments, along with the impacts 
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(costs, emission reductions, risk reductions, etc.). We then 

make a decision on whether it is necessary to amend the 

regulation to require any identified developments. 

Based on specific knowledge of the primary lead smelting 

source category, we began by identifying known developments in 

practices, processes, and control technologies. For the purpose 

of this exercise, we considered any of the following to be a 

“development”: 

• Any add-on control technology or other equipment that was 

not identified and considered during MACT development; 

• Any improvements in add-on control technology or other 

equipment (that was identified and considered during MACT 

development) that could result in significant additional 

emission reduction; 

• Any work practice or operational procedure that was not 

identified and considered during MACT development; and 

• Any process change or pollution prevention alternative that 

could be broadly applied that was not identified and 

considered during MACT development. 

In addition to looking back at practices, processes, or 

control technologies reviewed at the time we developed the MACT 

standards, we reviewed a variety of sources of data to aid in 

our evaluation of whether there were additional practices, 

processes, or controls to consider. One of these sources of 
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data was subsequent air toxics rules. Since the promulgation of 

the MACT standard for the primary lead smelting source category 

addressed in this proposal, EPA has developed air toxics 

regulations for a number of additional source categories. We 

reviewed the regulatory requirements and/or technical analyses 

associated with these subsequent regulatory actions to identify 

any practices, processes, and control technologies considered in 

these efforts that could possibly be applied to emission sources 

in the primary lead smelting source category. 

We also consulted EPA’s RACT/BACT/LAER Clearinghouse 

(RBLC). The terms "RACT," "BACT," and "LAER" are acronyms for 

different program requirements under the CAA provisions 

addressing the national ambient air quality standards. Control 

technologies, classified as RACT (Reasonably Available Control 

Technology), BACT (Best Available Control Technology), or LAER 

(Lowest Achievable Emission Rate) apply to stationary sources 

depending on whether the sources are existing or new, and on the 

size, age, and location of the facility. BACT and LAER (and 

sometimes RACT) are determined on a case-by-case basis, usually 

by state or local permitting agencies. EPA established the RBLC 

to provide a central database of air pollution technology 

information (including technologies required in source-specific 

permits) to promote the sharing of information among permitting 

agencies and to aid in identifying future possible control 
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technology options that might apply broadly to numerous sources 

within a category or apply only on a source-by-source basis. 

The RBLC contains over 5,000 air pollution control permit 

determinations that can help identify appropriate technologies 

to mitigate many air pollutant emission streams. We searched 

this database to determine whether any practices, processes, or 

control technologies are included for the types of processes 

covered by the primary lead smelting MACT. 

We also requested information from the facility regarding 

developments in practices, processes, or control technology. 

Finally, we reviewed other information sources, such as state or 

local permitting agency databases and industry-supported 

databases. 

C. Overview of the source category and MACT Standards. 

 1. Source Category and MACT Standard

 The National Emission Standard for Primary Lead Smelting 

(or MACT rule) was promulgated on June 4, 1999 (64 FR 30194) and 

codified at 40 CFR part 63, subpart TTT. As promulgated in 

1999, the MACT standard applies to affected sources of HAP at 

primary lead smelters16. The MACT defines “Primary lead 

smelters” as “any facility engaged in the production of lead 

metal from lead sulfide ore concentrates through the use of 

 

16 As provided above in section III (C)(3), we are proposing to change the 

standard to apply to a Primary Lead Processors 
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pyrometallurgical techniques.” 40 CFR 63.1542. The MACT 

standard for the Primary Lead Smelting source category does not 

apply to secondary lead smelters, lead remelters, or lead 

refiners (§63.1541). Today there is one facility (The Doe Run 

Company in Herculaneum, Missouri) operating that is subject to 

the MACT standards (See Section V.A. below). 

 At the time of promulgation of the Primary Lead Smelting 

MACT rule, there were three operating lead smelters. Due to 

economic pressures (decreased market demand for lead) and 

regulatory pressures, two of the lead smelting facilities 

subject to the MACT standard have since been permanently closed, 

leaving one primary lead smelter currently operating in the 

United States. No new primary lead smelters have been built in 

the last 20 years, and no new primary lead processing facilities 

using pyrometallurgical techniques are anticipated in the 

foreseeable future. The one operating lead smelter is not 

collocated with other sources of HAP emissions. 

 Lead is used to make various construction and consumer 

products such as batteries, paint, glass, piping, and filler. 

Lead sulfide (PbS) ore concentrates are the main feed material 

to primary lead smelters. The primary lead smelting process 

consists of lead sulfide concentrate storage and handling, 

sintering of ore concentrates, sinter crushing and handling, 

smelting of sinter to lead metal, drossing (i.e., removing the 
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solid oxide deposits), refining and alloying of lead metal, and 

smelting of the drosses. 

HAP are emitted from primary lead smelting as process 

emissions (stack), process fugitive emissions, and fugitive dust 

emissions. Process emissions are associated with the exhaust 

gases from sinter machines and blast and dross furnaces. HAP 

expected in process emissions are metals (mostly lead compounds, 

but also some arsenic, cadmium, and other metals) and also may 

include small amounts of organic compounds that result from 

incomplete combustion of coke, which is charged along with 

sinter to the blast furnace. Process fugitive emissions occur 

at various points during the smelting process (such as during 

charging and tapping of furnaces) and the only HAP emitted are 

metal HAP. Fugitive dust emissions result from the entrainment 

of dust due to material handling, vehicle traffic, and wind 

erosion from storage piles and the only HAP emitted are metal 

HAP. 

The MACT standard (40 CFR Part 63, subpart TTT) applies to 

process emissions (stack) from sinter machines, blast furnaces, 

and dross furnaces; process fugitive emissions from sinter, 

blast furnace, drossing and refining processes, concentrate 

handling, and locations around such processes; and fugitive dust 

emission sources, such as roadways, storage piles and the plant 

yard. Process emissions of lead compounds from sinter machines, 
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blast furnaces, and dross furnaces, and process fugitive 

emissions from the blast furnace and dross furnace charging, 

blast furnace and dross furnace tapping, and the sinter machine 

(charging, discharging, crushing, and sizing) are limited to 500 

grams (g) of lead emissions per mega gram (Mg) of lead produced 

(500 g/Mg), which is equal to 1.0 pound (lb) of lead emissions 

per ton of lead produced (1 lb/ton). 40 CFR 63.1542(a). A 

plant-wide limit format was used for MACT because it was 

consistent with SIPs, the commingling of exhaust gases from 

processes to a single stack made it impossible to set limits for 

individual sources, it gave the facilities more flexibility in 

complying with the standard, and it promoted pollution 

prevention by giving each facility the ability to meet the 

emission limit through any combination of source reduction and 

control technology options. (63 FR 19208). 

In addition to being subject to the plant-wide emission 

limit of the standard, process fugitive emissions must be 

captured by a hood and ventilated to a baghouse or equivalent 

control device and the hood design and ventilation rate must be 

consistent with American Conference of Governmental Industrial 

Hygienists recommended practices. 40 CFR 63.1543(b). In 

addition, the sinter machine area fugitives must be enclosed in 

a building that is ventilated to a baghouse at a rate that 

maintains a positive in-draft through any doorway opening. 40 
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CFR 63.1543(c). The MACT standard also requires the use of bag 

leak detection systems for continuous monitoring of baghouses. 

40 CFR 63.1547(c)(9). For fugitive dust sources, as defined in 

40 CFR 63.1544, the MACT standard requires that the owner or 

operator prepare and operate at all times according to a 

standard operating procedures (SOP) manual. The SOP manual must 

describe in detail the measures used to control fugitive dust 

emissions from plant roadways, material storage and handling 

areas, sinter machine areas, blast and dross furnace areas, and 

refining and casting operations areas. Existing work practice 

manual(s) that describe the measures in place to control 

fugitive dust sources required as part of a state implementation 

plan for lead satisfy this requirement. 

2. MACT as it applies to Doe Run Company Primary Lead 

Smelter, Herculaneum, Missouri

As stated above, the Doe Run Smelter in Herculaneum, 

Missouri is the sole remaining lead processing facility in the 

United States subject to the MACT. The 1999 MACT rule 

established a plant-wide lead emission limit of 1 lb of lead per 

ton of lead produced that applies to the aggregation of 

emissions from specific sources that discharge from air 

pollution control devices. Compliance with the plant-wide 

emission limit is demonstrated by annual stack testing. The 

rule lists nine sources as subject to the plant-wide limit 
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including; 1)sinter machine, 2)blast furnace, 3)dross furnace, 

4) dross furnace charging location, 5)blast furnace and dross 

furnace tapping location, 6)sinter machine charging location, 

7)sinter machine discharge end, 8)sinter crushing and sizing 

equipment, and 9)sinter machine area. At the Doe Run plant, 

lead emissions from these sources are controlled by baghouses 

that exhaust through two stacks. The sources in the sinter 

operation, the blast furnace, and the dross furnace are 

controlled by three baghouses all of which discharge through one 

emission point, which is designated as the main stack. The 

building that houses the blast furnace and dross kettles is 

vented to a separate baghouse (#7) which discharges through a 

separate stack, designated as the furnace area stack. 

Under the 1999 MACT rule, all other sources of process 

fugitive and fugitive dust emissions are required to follow work 

practice standards detailed in the plant’s standard operating 

procedures (SOP) manual. 

 The HAP emitted in the largest quantities from the Doe Run 

facility are lead compounds, which account for over 99 percent 

of the total HAP emissions by mass. The remaining HAP emissions 

are arsenic, antimony, cadmium, cobalt, nickel and trace organic 

HAP. Negligible levels of organic HAP are also emitted from 

natural gas-fired space heating at the facility and the 

incomplete combustion of coke in the blast furnace. Further 
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discussions of the emission profile for this facility is 

included in the Technical Support Document in the docket. 

3. Missouri SIP and the lead NAAQS as they apply to Doe 

Run Company, Herculaneum, Missouri

In addition to the MACT standard, the Doe Run Company’s 

primary lead smelter in Herculaneum, Missouri is subject to a 

SIP for the purpose of attaining and maintaining the lead 

NAAQS.17 The current SIP, which was approved in 2002, addresses 

the former lead ambient air concentration limit of 1.5 μg/m3

NAAQS. In addition, the 2007 SIP submittal from the State 

includes requirements addressing lead emissions from the Doe Run 

facility and can be found at 

http://www.dnr.mo.gov/env/apcp/docs/2009drh-leadsip.pdf. 

In 2008, EPA revised the lead NAAQS from 1.5 μg/m3

 to 0.15 

μg/m3

. In November 2010, EPA identified or “designated” several 

areas as not meeting the lead NAAQS. These “nonattainment” 

designations include portions of Jefferson County, Missouri 

surrounding the Doe Run facility. Missouri is required by the 

Act to take steps to further control pollution in this area, and 

to detail these steps in a revision to the SIP. The revised SIP 

is due to EPA within eighteen months after the effective date of 

 

17 EPA most recently approved the Missouri SIP for Herculaneum in 2002 (67 FR 

18497, April 16, 2002). Missouri Department of Natural Resources (MDNR) 

substantially revised the requirements for the smelter in 2007. EPA has 

proposed approval of this revision, but has not yet taken final action. 
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the designation, or by June 2012, and attainment of the NAAQS 

should be achieved by 2016. 

The SIP and the pending 2007 SIP submittal contain specific 

measures to be implemented by the Doe Run plant to reduce lead 

emissions. The State of Missouri revised the control 

requirements for the Doe Run facility in 2001 and 2007, 

requiring numerous emissions-reducing measures and improvements 

to add-on control devices, processes, and work practices.18 

These included improvements to existing emission control 

technology, adding or upgrading enclosures, process changes and 

limitations, and work practices. These requirements are 

summarized below. 

Point Source Requirements - As required under the SIP, lead 

emissions from the refining kettles and refining building 

emissions must be captured and vented to baghouses. Doe Run 

implemented these controls and vents the emissions to baghouses 

#8 and #9 and the exhaust from the baghouse #9 is combined with 

baghouse #7 exhaust and vented to a common stack. Although the 

MACT standard does not require Doe Run to do so, it has included 

emissions from refining Baghouses #8 and #9 in their 

 

18 EPA most recently approved the Missouri SIP for Herculaneum in 2002 (67 FR 

18497, April 16, 2002). MDNR substantially revised the requirements for the 

smelter in 2007. EPA has proposed approval of this revision, but has not yet 

taken final action. 
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demonstrations of compliance with the MACT plant-wide lead 

emission limit. 

Under the 2007 SIP submittal, Doe Run was required to make 

improvements to existing baghouse controls including the 

installation of pleated filters and lowering the air-to-cloth 

ratio for baghouses, increased ventilation and improved 

ventilation hoods at the blast furnace, and using reverse flow 

technology for baghouse cleaning. The 2007 SIP submittal also 

required the installation of enclosures and/or partial 

enclosures for unloading ore concentrate, sinter storage, and 

the sides of the sinter machine (which will be evacuated to a 

baghouse). 

 Process Requirements - Process changes to reduce emissions 

required by the SIP included a process control system for the 

injection of air through the blast furnace tuyeres located at 

the bottom of the blast furnace, limitations on individual 

process and overall plant throughputs, and limiting specific 

operations to only certain times of the day when the impact on 

ambient air concentrations is less. The SIP also stipulates 

that emissions from malfunctions will be reduced by alarms that 

sound when the baghouse fan malfunctions, an interlock system to 

restrict air flow into the blast furnace when the baghouse is 

not operating properly, and cameras for the dross and refinery 

kettles to detect kettle failure (i.e., when a plume of smoke is 
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detected from the stack, the kettle burner can be immediately 

shut off and the problem corrected). 

 Fugitive Dust Requirements - Under both the current SIP and 

the 2007 SIP submittal, work practices are required to reduce 

fugitive dust emissions. Requirements include road watering and 

automatic sprinklers, using new regenerative sweepers to remove 

dust from paved surfaces to reduce emissions from traffic, 

maintaining a minimum water content percentage for ore 

concentrate and for baghouse dust that is loaded into railcars, 

and inspecting the siding that encloses buildings (followed by 

prompt repairs if needed). 

Missouri requires Doe Run to report all metal HAP emissions 

annually based on a speciation analysis that was performed19. 

The state also requires an annual emissions inventory based on 

the stack tests for the point discharges and AP-42 or facilityspecific emission factors for fugitive emissions. 

As a result of the implementation of the emission control 

requirements in the currently approved 2002 SIP, and the 

additional requirements adopted by the state, as discussed 

above, the Doe Run facility has achieved a significant reduction 

of lead and metal HAP emissions since 2000 through a combination 

of reduced production levels and improved emissions controls. 

 

19 Doe Run Company submits annual emissions inventories to MDNR that report 

speciated metals using speciation factors for each metal/source derived in 

the late 1990’s through emissions testing. 
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Based on emissions inventory data submitted to the Missouri 

Department of Natural Resources (DNR), total HAP emissions have 

been reduced from an estimated 140 tons in 2000 to 20 tons in 

2008, and the majority of the 20 tons are lead compound 

emissions. The 2008 reported emissions reflect implementation 

of all emission controls stipulated in the 2002 SIP and the 2007 

SIP revision. 

4. Other Federal and State Actions Affecting Doe Run 

Company 

More recently, the 2008 revision to the lead NAAQS has 

resulted in Doe Run Company deciding that it is not feasible for 

the facility to reduce emissions further to the level necessary 

to meet the newly revised NAAQS without closure of the current 

smelting operations. As a result of past and ongoing regulatory 

compliance issues at the facility, the facility has entered into 

a consent decree with US EPA Region VII and the State of 

Missouri. Under the consent decree, the facility will, among 

other things, close the existing smelter operation and remediate 

the site to an agreed-upon level. The consent decree requires 

that all support operations for the smelter cease by December 

31, 2013 and that the blast furnace cease operations by April 1, 

2014. Remediation of the site is required to commence following 

approval of a plan to be submitted to EPA in January 2013. 

Under the consent decree, the existing refining, casting and 
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alloying operations will be allowed to continue operation. 

Notice of the consent decree was published for public comment on 

October 15, 2010, (75 FR 63506). Once finalized, the consent 

decree is federally enforceable among the parties. 

Prior to closure of the current smelter, the Doe Run 

Company may build and bring to full operation a new 

hydrometallurgical process that will produce lead from lead 

sulfide ore, potentially on the same propertyadjacent to as the 

current smelter. The hydrometallurgical process uses chemical 

reactions involving fluboric acid which allows recovery of lead 

metal through leaching, electrowinning, and co-product treatment 

processes. Some of the lead from the new process is likely to 

undergo further processing at the existing refinery, primarily 

for remelting/casting purposes. Based on limited data from a 

demonstration project, Doe Run expects that lead emissions from 

the hydrometallurgical process will be minimal. 

V. Analyses Results and Proposed Decisions 

 This section of the preamble provides a description of the 

dataset used in the RTR analysis, the results of our RTR for the 

source category, and our proposed decisions concerning changes 

to the Primary Lead Smelting MACT standard. As noted 

previously, all references to lead emissions in this proposal 

means “lead compounds,” which is the regulated HAP under CAA 
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section 112. All reference to lead production means the 

production of element lead. 

A. What data were used in our risk analyses?

For the Primary Lead Smelting source category, we compiled 

a preliminary dataset using readily available information, 

reviewed the data, and made changes where necessary. The 

preliminary dataset was based on data in the 2002 National 

Emissions Inventory (NEI) Final Inventory, Version 1 (made 

publicly available on February 26, 2006), and the 2005 National 

Emissions Inventory (NEI), version 2.0 (made publicly available 

in October 2008). The 2005 NEI was updated to develop the 2005 

National Air Toxics Assessment (NATA) Inventory. NATA inventory 

updates for the primary lead smelting category included SIP data 

provided by the state of MO to EPA. The 2005 NATA inventory was 

used with updated 2008 data received in an Information 

Collection Request (ICR) response from the Doe Run facility. 

The NEI is a database that contains information about sources 

that emit criteria air pollutants, their precursors, and HAP. 

The NEI database includes estimates of annual air pollutant 

emissions from point and volume sources, emission release 

characteristic data such as emission release height, 

temperature, velocity, and location latitude/longitude 

coordinates. We reviewed the NEI datasets, checked geographic 

coordinates, and made changes based on available information. We 
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also reviewed the emissions and other data to identify data 

anomalies that could affect risk estimates. 

The risk assessment was based on estimates of the actual 

emissions and allowable emissions. The estimates of actual 

emissions were for the year 2008 and were based on data from the 

ICR along with data from our NEI dataset. These estimates 

included both stack and fugitive emission sources. Fugitive 

dust sources include material handling (concentrate, sinter, 

fume and dross), plantwide resuspension (roadways, storage piles 

and plant yard) and other miscellaneous sources (vents and heat 

stacks). The material handling sources contribute approximately 

87 percent of the total fugitive dust emissions, while plantwide 

resuspension and miscellaneous sources contribute approximately 

9 and 4 percent, respectively. The estimates of allowable 

emissions were calculated using production data from the ICR 

response combined with the current emissions limits in the MACT 

standard. 

Lead compounds account for about 99 percent of the HAP 

emissions from the source category, or about 20 tons in 2008. 

The facility also reported small emissions of five other metal 

HAP, and trace levels of 25 organic HAP. 

The emissions data, calculations and risk assessment inputs 

for the Primary Lead Smelting source category are described 

Formatted: Not Highlight
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further in the Technical Support Document for this action which 

is available in the docket for this proposed rulemaking. 

 We used the 2008 production information as the basis for 

calculating the MACT allowable ratio (allowable to actual) 

because the 2008 emissions are the most recent reported 

emissions that also reflect implementation of the requirements 

of the 2007 SIP revision. For more information on the ratio of 

actual to MACT-allowable emissions, see the Technical Support 

Document in the docket for this action describing the emission 

data information and estimation of MACT-allowable emission 

levels and associated risks and impacts. 

B. What are the results of the risk assessments and analyses?

 For the Primary Lead Smelting source category, we 

conducted an inhalation risk assessment for all HAP emitted. We 

also conducted a multi-pathway analysis for cadmium and lead. 

With respect to lead, we used the recently-promulgated lead 

NAAQS to evaluate the potential for multi-pathway and 

environmental effects. Furthermore, we conducted a demographic 

analysis of population risks. Details of the risk assessments 

and additional analyses can be found in the residual risk 

documentation referenced in section IV.A of this preamble, which 

is available in the docket for this action. 

 1. Inhalation Risk Assessment Results. 
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 Table 3 provides an overall summary of the results of the 

inhalation risk assessment. 

Table 3. Primary Lead Smelting Inhalation Risk Assessment 

Results 

Maximum 

Individual 

Cancer Risk 

(in 1 million)1 Estimated 

Population 

at Risk ≥ 1-

in-1 Million 

Estimated 

Annual 

Cancer 

Incidence 

(cases 

per year) 

Maximum 

Chronic Non-cancer 

TOSHI2 Maximum Offsite refined 

Acute Noncancer HQ3

Actual 

Emissions 

Level 

Allowable 

Emissions 

Level 

Actual 

Emissions 

Level 

Allowable 

Emissions 

Level 

30 30 4,900 0.0008 1 1 0.6 

1

 Estimated maximum individual excess lifetime cancer risk. 

2

 Maximum TOSHI. The target organ with the highest TOSHI for the 

Primary Lead Smelting source category is the kidney. 

3

 The maximum acute HQ value shown uses the only available acute doseresponse value for arsenic, which is the REL. See section IV.A of 

this preamble for explanation of acute dose-response values. 

 The results of the chronic inhalation cancer risk 

assessment indicate that, based on estimates of actual emissions 

from the base year 2008, the maximum individual lifetime cancer 

risk could be as high as 30-in-1 million with fugitive dust 

emissions of cadmium dominating the risk. The total estimated 

cancer incidence from this source category based on actual 

emission levels is 0.0008 excess cancer cases per year or one 

case in every 1,250 years. Approximately 200 people were 

estimated to have cancer risks above 10-in-1 million and 

approximately 4,900 people were estimated to have cancer risks 

above 1-in-1 million. When considering the maximum levels of 

emissions allowed under the current MACT standard, the MIR 

remains 30-in-1 million. The MIR remains the same since the 
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fugitive dust emissions are governed by work practices, which 

under §63.1544 are defined as the measures that will be “put 

into place to control fugitive dust emissions.” Thus, the 

actual emissions, which reflect the measures that have been put 

in place, should be equivalent to the allowable emissions. 

 The maximum chronic noncancer TOSHI value is 1, with 

fugitive emissions of cadmium dominating those impacts. When 

considering MACT allowable emissions, the maximum chronic 

noncancer TOSHI value remains 1 since, for the reasons provided 

above, MACT-allowable fugitive emissions are equal to actual 

fugitive emissions. 

 Based on the acute REL value for arsenic, an off-site 

screening-level acute HQ value from this facility could be as 

high as 6. However, the emissions factor of 10 times the 

average hourly emissions rate is not appropriate in this 

instance, given that fugitive emissions are minimized during the 

meteorological conditions associated with the worst-case shortterm impacts (i.e., during low-wind, stable atmospheric 

conditions). Thus, we refined the assessment and estimated a 

maximum off-site HQ value of 0.6. 

 The results of a multipathway screening analysis for 

cadmium emissions from this facility were well below the de 

minimis emission rate that would indicate a non-negligible risk 

of adverse health effects from multipathway exposures. We 
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estimate the specific multipathway de minimis emission rate for 

cadmium to be 0.65 TPY and only 0.1 TPY is emitted from the one 

facility in this source category. Thus, there appears to be 

little, if any, multipathway risk associated with cadmium 

emissions from this facility. 

 In evaluating the potential multi-pathway risks from 

emissions of lead compounds, we compared modeled maximum 3-month 

rolling average atmospheric concentrations with the NAAQS for 

lead. Table 4 presents the results of our lead impact analysis 

broken down by emission point considering actual 2008 emissions 

as well as the maximum emissions of lead that the MACT standard 

would have allowed based on production rates for calendar year 

2008 year. For purposes of our analysis, we determined 

separately the risk from each of the types or 

processes/emissions sources regulated by the current MACT, with 

one exception. Under the MACT, emissions from the refining and 

casting area were considered fugitive emissions subject to work 

practice standards under section 63.1544. Since then, pursuant 

to requirements that the 2002 State SIP adopted for purposes of 

meeting the 1.50 μg/m3 lead NAAQS, Doe Run enclosed the refining 

and casting area and vents those emissions to the refinery 

stacks.. We considered these stack emissions separate from the 

fugitive dust emissions. Thus, the four emission process/sources 
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we evaluated for risk were: (1) the main stack, (2) the furnace 

area stack, (3) the refinery stack, and (4) fugitive emissions. 

 The analysis indicates that under both actual 2008 or MACT 

allowable emission scenarios, emissions from the main stack do 

not result in lead levels above the NAAQS within the 50 km 

radius that was modeled. This is likely due to the height of 

the stack (500 feet), which would result in broader and further 

dispersal of lead emissions. However, results of the analysis 

did indicate that modeled ambient air lead concentrations 

resulting from this facility’s fugitive dust emissions could 

exceed the NAAQS for lead by as much as 50-fold at the property 

boundary based on both actual and allowable emissions. 

Moreover, results indicate that modeled emissions from the 

furnace area stack could result in NAAQS exceedances under both 

actual 2008 and MACT-allowable emissions scenarios. In 

addition, the actual estimated emissions from the refining 

stacks, which were put into place based on requirements adopted 

by the State for purposes of the SIP, could result in NAAQS 

exceedances. We were unable to calculate a “MACT allowable” 

emission level for the refinery emissions, which under the MACT 

are included as fugitive emissions. This analysis also 

indicates that within 50 km of this facility, approximately 

1,900 people could be exposed to ambient air lead concentrations 

exceeding the level of the NAAQS for lead. 
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 As mentioned above, to evaluate the potential for adverse 

environmental effects, we also compared maximum 3-month rolling 

average atmospheric concentrations with the current secondary 

NAAQS for lead, which is the same as the primary standard. 

Thus, the analyses presented in Table 4 also indicate the 

potential for adverse environmental effects from emissions of 

lead. 

 Table 4. Summary of Modeled Lead Concentrations Relative to 

the NAAQS Based on Estimated Actual 2008 and MACT Allowable 

Emissions 

Emission Point

Actual 

2008 

Emissions 

(TPY)

Maximum 

ImpactActual 

Emissions

 Allowable 

Emissions1 

(TPY)

Maximum ImpactAllowable 

Emissions

Main stack2 13.31 0.05 times the 

NAAQS

65.8 0.25 times the 

NAAQS

Refining stacks 2.74 3 times the 

NAAQS

NA NA

Furnace area 

stack: 

(controlled 

blast and 

drossing 

fugitives)

1.81 2 times the 

NAAQS

8.94 10 times the 

NAAQS

Fugitive dust3 2.85 50 times the 

NAAQS

2.85 50 times the 

NAAQS

1 Allowable emissions for the main stack and furnace area emission points are 

based on 1 lb of Pb/ton production (MACT limit); Refinery emissions are 

included as fugitive emissions under MACT but are now vented to a stack 

because of SIP requirements, therefore, we were unable to calculate a “MACT 

allowable” emission level. 

2 Main stack is the emission point for sinter machine, blast furnace and 

drossing operations. 

3 Fugitive dust emissions are covered by work practices under current MACT 

and were calculated via emission factors assuming compliance with the MACT. 

The site of maximum ambient air lead concentration resulting from fugitive 

dust emissions occurs in close proximity to the south east boundary of the 

facility (see Figure 3.1-1 of the risk assessment document.) Note this 

differs from inputs used for other types of modeling (e.g., SIP modeling.)

). 
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 2. Facility-wide Risk Assessment Results. 

 Our screening analysis determined that the organic HAP 

emissions from facility represented negligible risk and were 

determined to be insignificant with regard to this risk 

analysis. As a result, all significant HAP emissions from the 

one facility in this category are reflected in the risk analyses 

presented above; therefore, facility-wide risks are equivalent 

to those of the source category. 

 3. Model to Monitor Comparison

 In addition to the results presented above, we also 

compared maximum AERMOD estimates of ambient air lead 

concentrations with those measured at 4 monitors in close 

proximity to the Herculaneum Primary Lead Smelting Facility for 

calendar year 2008. More specifically, we compared maximum 3-

month rolling average lead concentrations (for calendar year 

2008) calculated from data reported at the Main Street, Circle 

Street, South Cross, and Church Street monitors to the maximum 

3-month rolling average lead concentrations at model receptor 

locations in close proximity to these monitoring sites. These 

monitor locations were chosen because they represented the 

closest offsite monitors to the Herculaneum primary lead 

smelter. Thus, lead measurements at these monitoring sites 

would likely be dominated by emissions from this facility - 
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which is important given that AERMOD estimates of ambient air 

lead concentrations only considered lead emissions from this 

facility (i.e., only lead emissions from the Herculaneum primary 

lead smelter were used as inputs into AERMOD). 

 Results of this analysis are presented in Table 5 and 

indicate that with respect to the Main Street and Circle Street 

monitors, AERMOD underestimates 3-month maximum lead 

concentrations by approximately 2.8- and 4.2-fold, respectively. 

While these monitor to model comparisons are not in complete 

agreement on a point-by-point basis, we note that this would not 

be expected given the general uncertainties associated with 

using dispersion modeling to estimate ambient pollutant 

concentrations and considering that the meteorological data used 

to develop the model estimates were from a different year than 

the actual monitoring and emissions data (i.e., meteorological 

data used in the AERMOD simulation was from 1998 while the 

emissions estimates and the monitoring data were from 2008). 

However, results do indicate that the maximum 3-month average 

lead concentration across the group of monitors nearest the 

facility is approximately equal to the maximum 3-month average 

lead concentration estimated by AERMOD across the group of these 

monitoring sites (i.e., both the Main Street monitor and the 

South Cross AERMOD estimate indicate the maximum 3-month average 

lead concentration to be approximately 2.1 μg/m3). Taken 
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together, these results indicate that AERMOD estimates of 

ambient air lead concentration provide a reasonable 

representation of the measured 3-month maximum lead 

concentrations present in the ambient air near this facility. 

Table 5. Comparison of AERMOD modeled to ambient air lead 

concentrations reported by four monitors surrounding the 

Herculaneum Primary Lead Smelting Facility. 

Location

Maximum AEMOD 

Modeled 3-Month 

Lead 

Concentration

(μg/m3

) 

Maximum 

Monitored 3-

Month Lead 

Concentration 20 

(μg/m3) 

Model to 

Monitor 

Ratio21

Main Street 0.47 3.14 -4.6

Circle Street 0.38 1.14 -3.0

South Cross 2.13 0.75 2.8

Church Street 1.99 0.47 4.2

4. Demographic Risk Analysis Results. 

 Demographic analyses were performed to investigate the 

population distribution of: 1) cancer risks at or above 1-in-1 

million and 2) risks from ambient air lead concentrations above 

the NAAQS for lead. Results are summarized in Table 5 and are 

based on modeling using estimated actual emissions levels for 

the population living within 50 km of this facility. 

 

20 Maximum 3-month monitored concentrations were calculated for the year 2008 

based on data submitted to EPA’s Air Quality System (AQS). 

21 Negative sign denotes an underestimation of AERMOD modeled ambient lead 

concentrations, relative to monitored concentrations. AERMOD estimated 

concentrations were based on the 2008 emissions estimates described in 

section V.A. 
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Table 6. Primary Lead Smelting Demographic Risk Analysis 

Results 

Nationwide 

Population with 

cancer risk 

greater than 1 in 

a million

Population with 

ambient air lead 

concentrations 

exceeding the 

NAAQS

Total 

population 

285,000,000 4,900 1,900 

Race by percent

White 75 96 96 

All Other 

Races 25 4 4 

Race by percent

White 75 96 96 

African 

American 12 4 3 

Native 

American 0.9 0.2 0 

Other and 

Multiracial 12 1 0.8 

Ethnicity by percent 

Hispanic 14 1 0.3 

Non-Hispanic 86 99 99.7 

Income by percent

Below poverty 

level 13 15 15 

Above poverty 

level 87 85 85 

 Results of the risk assessment indicate that there are 

approximately 4,900 people exposed to a cancer risk greater than 

1-in-1 million, and 1,900 people in areas with ambient air lead 

concentrations above the NAAQS for lead. In both instances, the 

demographics analysis estimates that about 4 percent of these 

populations can be classified as a minority (listed as “all 

Other Races” in the table), which is well below the national 
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percentage of 25. Similarly, in the cancer and lead demographic 

analyses, the percentage of “African American,” “Hispanic,” 

“Native American,” and “Other and Multiracial” population groups 

are well below the corresponding national percentages. With 

respect to the percentage of those “Below the Poverty Level,” in 

both demographic analyses there is a small (2 percent) increment 

above the corresponding national percentage. However, given that 

the total population affected is small (i.e., 4,900 individuals 

for cancer risk greater than 1-in-1 million and 1,900 

individuals in areas with lead concentrations above the NAAQS), 

we do not think this indicates any significant potential for 

disparate impacts to the specific demographic groups analyzed. 

 Moreover, given the extent to which lead may impact 

children’s health, we further note that our demographic analysis 

doesn’t indicate the presence of a higher percentage of children 

than one would normally expect around this facility. That is, 

while the national percentage of children 18 years and younger 

is 27%, the percentage of children living near this facility who 

are estimated to be exposed to lead concentrations above the 

NAAQS is only slightly higher at 28% (see Risk and Technology 

Review - Analysis of Socio-Economic Factors for Populations 

Living Near Primary Lead Smelting Facilities in the docket for 

this proposed rulemaking), a difference which is likely not 

significant. 
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C. What are our proposed decisions on risk acceptability and 

ample margin of safety?

1. Risk Acceptability.

 As noted in section III.B of this preamble, we weigh all 

health risk factors in our risk acceptability determination, 

including cancer risks to the individual most exposed, risk 

estimation uncertainty, and other health information. For the 

Primary Lead Smelting source category, the risk analysis 

indicates that the cancer risks to the individual most exposed 

could be as high as 30-in-1 million due to actual or MACTallowable emissions. These risks are considerably less than 

100-in-1 million, which is the upper bound of the presumptive 

range of acceptability. The incidence of cancer is very low - 

0.0008 excess cancer cases per year; or one case every 1,250 

years. Similarly, the risks of chronic non-cancer health effects 

from HAP emissions other than lead were low, with a maximum HQ 

of 1. Moreover, while an initial screening analysis suggested 

that fugitive emissions of arsenic had the potential to create a 

risk of acute health effects, a refined analysis based on our 

knowledge of this emission source indicated that the risk was 

low (HQ = 0.6). In addition to these health analyses, a 

demographics analysis did not indicate the potential for 

significantly disproportionate heath impacts (see above, section 

V(3)(c)). Thus, risks associated with the non-lead emissions 
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from the Primary Lead Smelting source category for cancer, acute 

and chronic non-cancer health effects and environmental effects 

are considered acceptable. 

 However, since ambient air lead concentrations resulting 

from emissions from this facility were modeled to be in excess 

of the NAAQS for lead, the risks associated with lead emissions 

from this facility were judged to be significant. Our analysis 

estimated that modeled off-site ambient air lead concentrations 

(based on actual 2008 emissions) resulting from this facility 

could be as high as 50 times the NAAQS for lead based on 

fugitive dust emissions, and that approximately 1,900 

individuals could be exposed to lead concentrations in excess of 

the NAAQS. Given that the NAAQS for lead was set to “provide 

increased protection for children and other at-risk populations 

against an array of adverse health effects, most notably 

including neurological effects in children, including 

neurocognitive and neurobehavioral effects (73FR67007)”, we are 

proposing that risks associated with lead emissions from this 

source category are unacceptable. 

 As noted above, our risk analysis for lead was based on 

modeled 3-month rolling average lead concentrations in ambient 

air in comparison to the primary lead NAAQS. We believe that in 

order to provide an acceptable level of risk, lead 

concentrations in the ambient air must be reduced to the level 
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of the lead NAAQS. Thus, we considered specific emission limits 

for the three emission sources/points that were modeled to 

result in lead concentrations in excess of the NAAQS (see Table 

4); refinery stack, furnace area stack, and fugitive dust 

emissions, with the majority of fugitive dust impacts from 

concentrate handling. Based on our analysis, we conclude that 

in order to meet the NAAQS for lead at all model receptors, 

fugitive dust emissions would have to be reduced by 

approximately 98 percent to 0.064 TPY, refinery stack emissions 

and furnace area stack emissions would have to be reduced by 

approximately 80 percent to a total of 0.91 TPY (the maximum 

impacts of refinery and furnace emission points occur at the 

same location. Further, because the maximum ambient air impacts 

of the refinery/furnace emissions, the fugitive dust emissions, 

and the main stack do not significantly overlap each other, we 

estimate that lead emissions from all emission points other than 

the main stack would have to be limited to a total of 

approximately 0.97 TPY in order to ensure 3-month rolling 

average ambient air lead concentrations do not exceed the lead 

NAAQS level of 0.15 μg/m3

. As noted above, emissions from the 

main stack (i.e., emission point for sinter machine, blast 

furnace and drossing operations) did not result in ambient air 

lead concentrations in excess of the lead NAAQS at modeled 

locations within 50 km of the property boundary and thus we are 
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not proposing any reductions at the main stack in order to 

ensure an acceptable level or risk. 

 Once we determined the emissions reductions necessary to 

achieve an acceptable level of risk, we investigated available 

emissions control options and their ability to reduce emissions 

and health risks for fugitive dust and for stack emissions from 

both the refining and furnace area stacks. Control options 

considered for reducing fugitive dust emissions and associated 

risks include improved or additional work practices, site 

remediation, application of additional capture/control measures, 

and lead production limitations. With the exception of site 

remediation, all of these control measures have been implemented 

to varying degrees at the Doe Run facility in response to the 

Missouri SIP, as revised in 2002 and the 2007 revisions 

submitted for approval to the SIP. As such, because the actual 

emissions for 2008 reflect the implementation of those control 

measures, requiring those controls under the MACT would be 

unlikely to yield the additional 98 percent reduction in 

fugitive emissions necessary to meet the primary lead NAAQS 

level of 0.15 μg/m3. Thus, our evaluation of risks based on 

actual emissions already considered emissions with these 

controls largely in place. In order to substantially reduce 

fugitive dust emissions to a level that would ensure that the 

risk is not unacceptable, we believe that a complete remediation 
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of the primary lead smelter site including roadways, storage 

piles and other exposed surfaces, as well addition of controls 

or enclosures to further limit concentrate fume and sinter 

handling, is necessary. Such measures are necessary to prevent 

suspension and re-suspension of lead dust that make up fugitive 

dust emissions. In order to ensure that site remediation 

efforts, or any other efforts the source may choose to 

undertake, will result in sufficient emission reductions to 

address the unacceptable level of risk, we are proposing to 

establish lead concentration in air limit of 0.15 μg/m3 to be 

measured at locations approved by the Administrator. This lead 

concentration in air limit would be established as the 

enforceable requirement to address fugitive emissions under the 

MACT standard.22 Because we are proposing a concentration limit 

to address fugitive dust emissions, we no longer believe it is 

necessary for the affected facility to provide a plan to the 

Administrator describing work practices that will be used to 

reduce fugitive emissions. Therefore, we are proposing to 

remove the requirement to develop and submit a work practice 

standard operating procedure (SOP) manual as required in 

§63.1544(a). 

 

22 Under the consent decree, of which we sought public comment last fall, 

fugitive dust sources will be addressed by site remediation, however, some 

fugitive dust emissions will remain during the remediation of the site, which 

will likely extend beyond April 2014. 
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 As an alternative to proposing compliance monitoring 

requirements for demonstration of compliance with the lead 

concentration in air limit, we considered retaining the current 

fugitive dust emissions requirement to develop and submit to the 

Administrator or delegated authority a work practices SOP. 

Using this alternative approach, we believe it would be 

necessary to modify the current general requirements for an SOP 

by specifying the minimum work practice requirements that the 

plan must include. For example, under this alternative 

approach, we would require that the SOP must include, at a 

minimum, detailed descriptions of all measures that would be 

used to control fugitive dust emissions from plant roadways; 

material storage, transfer and handling areas; sinter machine 

areas; furnace areas; refining and casting areas; and other 

areas the Administrator may identify. Further, EPA would 

require that the SOP contain detailed descriptions of work 

practices including road watering and automatic sprinklers, 

methods to remove dust from paved surfaces to reduce emissions 

from traffic, maintenance of minimum water content for ore 

concentrate and for baghouse dust that will be handled or 

transferred, and procedures for the inspection of building 

siding or damages and openings. The SOP would be required to 

include procedures, including recordkeeping, to ensure that the 

work practices are being implemented at a frequency and in a 
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manner that would ensure that fugitive dust emissions are being 

minimized. To determine whether the work practices described in 

the SOP are reducing emissions sufficient to comply with the 

lead concentration in air limit, the owner or operator would be 

required once a year to model the fugitive dust emissions using 

measurement data or emission factors according to an approved 

fugitive dust emissions modeling plan. At a minimum, EPA would 

require that this modeling plan include a detailed description 

of each fugitive dust emission source; a detailed description of 

the control practices or techniques used to limit fugitive dust 

emissions from each source; the emission factors, test data or 

other methods used to characterize and quantify lead emissions 

from each source; a description of the emissions modeling that 

will be used to estimate the concentrations of lead in air at or 

near the property boundary as contributed by each source as well 

as cumulatively contributed by all sources; a description of 

process or other conditions that would indicate the need to 

demonstrate compliance more often than annually; the 

calculations to be used to show compliance with the air lead 

concentration limit that consider the highest modeled air lead 

concentrations from the modeled fugitive dust sources and any 

contributions from background lead concentrations in air; and a 

description of the records that will be kept. We are seeking 

comments on the proposed requirements to monitor air lead 
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concentrations versus the alternative approach described above, 

of requiring extensive work practices and a work practice SOP in 

conjunction with emissions modeling, to demonstrate compliance 

with the air lead concentration limit. 

 Measures available for reducing lead emissions from the 

refining and furnace area stacks include upgrading existing 

baghouses by replacing the existing fabric bags with high 

efficiency membrane bag filters. Another option would be to add 

extra in-line baghouses after existing baghouses. Such measures 

would reduce lead emissions and associated risk to within 

acceptable levels. 

 In summary, our analysis indicates that in order to ensure 

that lead emissions from this source do not pose an unacceptable 

risk, emissions from this facility would need to be reduced to a 

level that would ensure that these emissions would not result in 

air lead levels greater than the 0.15 μg/m3

 for any 3-month 

period at all of the modeled locations. Further, we conclude 

that in order to achieve the 0.15 μg/m3

 level (for any 3-month 

rolling average) at all modeled locations, fugitive dust 

emissions would need to be reduced by 98 percent and the 

emissions from the furnace area and refining operation stacks 

would need to be reduced by 80 percent. We have identified 

emission reduction and control options for achieving the 

required reductions, which include implementation of site 
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remediation, work practices, and upgrade of existing baghouses 

with membrane bags and/or addition of an additional in-series 

baghouse. 

 We are proposing the following requirements to ensure that 

risk is reduced to an acceptable level. 

 A stack lead emission cap of 0.91 TPY that would apply to 

the furnace area stack and the refining operation stacks. 

 An air lead concentration limit of 0.15 μg/m3

 based on 3-

month rolling average (to be measured at locations approved 

by the Administrator) to ensure that fugitive dust emission 

levels will not exceed the NAAQS. 

 The proposed limits apply to both new and existing 

facilities. Any facility subject to the MACT would be required 

to meet these requirements for each emission unit it is 

operating that is subject to the limit. In order to address any 

fugitive dust emissions, the facility, regardless of whether it 

is operating all or just some of the emission sources covered by 

this action, would be required to meet the air lead 

concentration emission limit. 

For both new and existing facilities, compliance with the 

air lead concentration limit would be demonstrated using lead 

compliance monitoring devices and would be based on a rolling 3-

month average concentration. The proposed rule requires 

development of a monitoring plan for approval by the 
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Administrator that includes the minimum sampling and analysis 

methods and compliance demonstration criteria provided in the 

rule. A provision is included in the proposed rule that allows 

for reduced monitoring if the facility demonstrates an air lead 

concentration for three consecutive years at less than 50 

percent of the air lead concentration limit. The monitoring can 

be reduced to once every six months unless one of the 6-month 

monitoring events exceeds 50 percent of the air lead 

concentration limit, at which time monitoring will be required 

to resume based on the initial plan approved by the 

Administrator until another three years of consecutive 

monitoring below 50 percent of the air lead concentration limit 

is achieved. The compliance requirements discussed above were 

designed to allow for flexibility, prevention of redundant 

requirements, and also to provide consistency with current 

monitoring required at the site. We are soliciting comment on 

this approach. For existing facilities, compliance with the 

emission limit for the furnace area and refinery stacks would be 

demonstrated through stack testing conducted on a quarterly 

basis. All performance testing will be consistent with the 

existing MACT testing requirements, with the exception of 

frequency. As provided in §63.153(e) of the current rule, the 

facility can reduce compliance testing frequency if the most 

recent three compliance tests demonstrated compliance. We are 
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maintaining this provision, however, because the proposed rule 

increases the testing frequency to quarterly, the number of most 

recent tests necessary to comply with this provision will be 

increased from three to 12. New primary lead processing 

facilities would be required to demonstrate compliance using a 

lead continuous emission monitoring systems (CEMS). However, 

since the Agency has not finalized the performance specification 

for the use of these instruments, we are deferring the effective 

date of the requirement to install, correlate, maintain and 

operate lead CEMS until these actions can be completed. The 

lead CEMS installation deadline will be established through 

future rulemaking, along with other pertinent requirements. In 

the event operations commence at a new facility prior to 

promulgation of the performance specification, compliance would 

be demonstrated though quarterly stack testing until 

promulgation of the lead CEMS performance specification. 

 2. Ample Margin of Safety.

 Reducing lead emissions to meet the NAAQS would ensure that 

emissions of all HAP do not pose an unacceptable risk. Once we 

ensure that the risk is acceptable, we then look to determine 

whether further reductions are appropriate to ensure an ample 

margin of safety. In this part of our analysis, we again 

consider the health factors we considered to determine whether 

the risks are acceptable but we also consider the cost of 
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controls. 

With regard to lead emissions, we are proposing to require 

most of the emission sources at the facility to implement all 

technically feasible controls in order to ensure that the 

ambient air meets the level of the lead NAAQS, which is the 

level that we have determined will ensure an acceptable level of 

risk. Because all feasible controls will need to be adopted in 

order to meet that proposed standard, there are no additional 

controls to consider for the three emission sources: fugitive 

dust emissions, the furnace area stack, and the refinery stacks. 

We further note that the same controls we have proposed for the 

three emission points to reduce lead emissions are the same 

controls that would reduce risks from cadmium and all other 

metal HAP known to be emitted from this source category. Thus, 

we are proposing that the controls required to ensure that risk 

from lead emissions from those three emission points is 

acceptable also protect public health with an ample margin of 

safety with regard to emissions from all metal HAP from these 

three emission points. Notably, after these standards are in 

place, we estimate that the MIR cancer risk due to the non-lead 

HAP will be less than 1 in 1-million. 

Our risk analysis indicates that the main stack emissions 

do not result in ambient air lead levels exceeding the NAAQS 

based on either actual or allowable emission levels. We 
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determined, as discussed section V.D. below, that it is 

technologically feasible to reduce emissions from the main stack 

to a level well below the allowable level of the MACT, since 

those levels are currently being achieved, and thus we are 

proposing to require such controls under CAA section 112(d)(6). 

We evaluated whether there were additional controls to further 

reduce emissions from the main stack and determined that lead 

emissions from the main stack could be further reduced by 

replacing the standard cloth bags with membrane bags at a 

capital cost of approximately $2 million and an annual cost of 

$0.3 million. Assuming a 50 percent reduction from 2008 main 

stack emissions, the cost of reducing lead emissions would be 

about $40,000 to $229,000 per ton of lead. (See the Technical 

Support Document included in the docket for a complete 

discussion of this analysis.) Because the highest ambient air 

lead concentration resulting from the emissions from the main 

stack already is more than 20 times below the level that is 

considered acceptable, it was determined that although 

additional controls such as membrane bags could result in 

additional emission reductions, the additional controls are not 

warranted since they would not appreciably reduce risk. We are 

proposing that the MACT standard, with the changes we are 

proposing under the section 112(d)(6) technology review as 

described in section V.D. below will provide an ample margin of 
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safety with regard to emissions of lead and other HAP from the 

main stack. 

D. What are the results and proposed decisions from the 

technology review? 

We evaluated developments in practices, processes, and 

control technologies applicable to emission sources subject to 

the Primary Lead Smelting MACT. This included a search of the 

RBLC Clearinghouse, the California BACT Clearinghouse, the 

internet, and correspondence with state agencies and industry. 

We have determined that there have been advances in emission 

control measures since the Primary Lead Smelting MACT standard 

was originally promulgated in 1999. 

The 1999 MACT limit was set using the lead emission limits 

from the lead SIPs for the three states in which primary lead 

smelting sources were operational at the time of the rulemaking. 

EPA took each of the three lead SIP limits, in lb/day, divided 

them by the corresponding lead production capacity, in tons/day, 

and calculated a lead emission rate in lb/ton. The results were 

as follows: 

ASARCO - Missouri 1.0 lb/ton 

ASARCO - Montana 1.0 lb/ton 

Doe Run - Missouri 0.84 lb/ton 

The values were ranked and the median value (1.0 lb/ton) 

was selected as representative of the MACT floor. 
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Since the MACT standard was promulgated, the industry has 

undergone significant changes. Two of the three facilities have 

shut down. The only remaining primary lead smelting facility is 

the Doe Run smelter at Herculaneum, Missouri, which is subject 

to control requirements under the Missouri SIP for lead. The 

existing SIP, as well as a 2007 SIP revision submitted by the 

State and proposed for approval by EPA require numerous 

emissions-reducing measures and improvements to add-on control 

devices, processes, and work practices. We considered these 

developments in practices, processes, and control technologies 

in our technology review. 

Recent emissions tests (2000 through 2008) at the Doe Run 

facility support that these improvements have resulted in 

significantly lower emissions and demonstrate that actual lead 

emissions from the facility are much lower than are allowed 

under the current MACT rule. To assess the impacts of 

developments in practices, processes and control technologies on 

lead emissions, emissions data from 2008 were compared with 

emissions data from 2000. Data from 2008 were selected because 

they reflect the many improvements that have been implemented at 

the facility since promulgation of the MACT rule. Emissions 

data from earlier years would not reflect all of the emissionreducing changes that have been implemented at the Doe Run 

facility given that some of the improvements were not 
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implemented until 2007 and 2008. As described above, 

technological improvements to baghouses and processes that have 

been implemented at the facility since the MACT rule was 

promulgated have resulted in substantially lower emissions from 

these sources at this facility. These improvements include 

upgrade of cloth bags and ventilation improvements. In 2008, 

lead emissions from the main stack, which vents emissions from 

the sintering operation and the blast and dross furnace, were 

13.31 TPY. In addition, emissions from the furnace area stack 

(i.e., the blast furnace and dross plant building which vent to 

baghouse 7) were 1.81 TPY, for a total of approximately 15.1 

TPY. At the 2008 lead production rate of 149,500 tons, the lead 

emission rate for these sources at Doe Run was about 0.2 lb/ton, 

or 80 percent less than the current MACT limit of 1 lb/ton. 

Based on this demonstrated performance, EPA believes that under 

Section 112 (d)(6), the MACT standard should be revised to 

reflect the reduction achieved in practice. 

Because we believe that the 2008 emissions of 13.31 TPY 

from the main stack (or combined sintering/blast 

furnace/drossing operations) reflect the annual rate of 

emissions achievable as a result of the technological 

improvements that have been made since 1999, we are proposing an 

emission limit based on the actual 2008 annual emissions that 

vent to the main stack (i.e., sintering, blast furnace and 
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drossing operations). In order to account for variability in 

the operation and emissions, recent stack tests were used to 

calculate the 95 percent upper predictive limit (UPL). The 95 

percent UPL for the main stack is 15 TPY. Variability in the 

operations and emission for this source are discussed in more 

detail in Section E below. 

Although we believe that there have been developments in 

processes, practices and control technologies with regard to the 

furnace area stack and with regard to refining and casting 

operations, as reflected by the more stringent requirements that 

have been implemented in accordance with the approved SIP and 

the 2007 SIP revisions; we are not proposing additional 

requirements for these stacks as part of our technology review 

because we have already proposed that these stacks implement all 

feasible controls, regardless of cost, in order to ensure that 

the risks due to these emission points are acceptable. Thus, 

there are no additional developments in practices, processes and 

control technologies beyond those which are reflected in the 

emission limits we have proposed to meet CAA section 112(f)(2), 

above. 

To be consistent with the existing MACT standard, EPA is 

proposing to retain the plant-wide pound per ton of production 

format that currently applies to the aggregate emissions from 

the main stack and the furnace area stack. Because there are 
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also stacks for the refining and casting operations, we are 

proposing to include those emissions as part of the plant-wide 

emission limit. Thus we are proposing a plant-wide lead 

emission limit of 0.22 pounds of lead per ton of lead produced 

based on the proposed reductions due to the section 112 (f)(2) 

risk review for the furnace area and refining operations stacks 

(discussed above in Section C) and the reduction in emissions 

from the main stack (sinter/blast furnace/drossing operations) 

based on this Section 112(d)(6) technology review This proposed 

plant-wide lead emission limit was determined by summing the 15 

TPY for the main stack and the 0.91 TPY for the furnace area and 

the refining operation, and dividing by the annual production 

from 2008 of 149,564 tons. We note that variability was only 

applied in establishing technology-based emissions from the main 

stack in order to establish a plant-wide emission limit. 

Because the emission levels required from the refining operation 

and furnace area stacks are based on acceptable risk, we 

conclude it is not appropriate to consider variability in 

establishing limits for these emission points. 

We are proposing that the plant-wide lead emission limit 

apply to new and existing facilities that are subject to the 

MACT. By default this would include any new, controlled lead 

processing source not currently covered, including lead 

processing by other than the current techniques. We are 
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requesting comment on the appropriateness of applying the plantwide lead emission limit to any future new lead processing 

technique. 

For the existing facility, compliance with the plant-wide 

stack emission limit would be demonstrated in the same manner as 

discussed above in section V.C.1 for the furnace area and 

refining stack limit (i.e., stack testing on a quarterly basis). 

We are proposing stack testing on a quarterly basis as opposed 

to testing on an annual basis since this allows the facility the 

opportunity to adjust their emissions throughout the year to be 

in compliance, rather than to find they are out of compliance at 

the end of the year, thereby risking violations. This schedule 

also coincides with other quarterly monitoring and reporting 

required of the facility. Also as discussed in section V.C.1, 

new primary lead processing facilities would be required to 

demonstrate compliance using lead continuous emission monitoring 

systems (CEMS). 

E. Variability

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 
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available data, to determine the level of emissions control that 

has been achieved by the best performing sources considering 

these sources’ operating variability). 

Variability in lead producers’ performance has a number of 

causes. For emissions of lead compounds that are 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.23 

In determining the contribution to a plant-wide emission 

limit of the main stack, we considered annual emissions 

discharged from the air pollution control devices that control 

lead emissions. For this rule, we used the 2008 emissions 

reported by Doe Run to the State of Missouri. 

We assessed variability using a statistical formula 

designed to estimate an emissions level that is equivalent to 

the source’s performance based on future compliance tests. 

Specifically, the calculated limit is an upper prediction limit 

(UPL) calculated with the Student’s t-test using the TINV 

 

23 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.
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function in Microsoft Excel®. The Student’s t-test has also 

been used in other EPA rulemakings (e.g., NESHAP for Portland 

Cement Manufacturing [75 FR 54970, September 9, 2010]; NSPS for 

Hospital/Medical/Infectious Waste Incinerators [74 FR 51368, 

October 6, 2009]; NESHAP for Industrial, Commercial, and 

Institutional Boilers and Process Heaters-Proposed [75 FR 32006, 

June 4, 2010]) 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 samples taken. The UPL consequently represents 

the value which we can expect the mean of future observations 

(3-run average for lead) to fall below within a specified level 

of confidence, based upon the results of an independent sample 

from 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 95 

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 sources past performance. 

This formula uses a pooled variance (in the s2

 term) that 
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encompasses all the data-point to data-point variability. Where 

variability was calculated using the UPL statistical approach, 

we used the sample standard deviation calculated from the 

emissions data distributions for lead. The standard deviation 

is the common measure of the dispersion of the data set around 

an average. We note here that the methodology accounts for both 

short-term and long-term variability and encompasses run-to-run 

and test-to-test variability. 

We adopted a form of the UPL equation that has been used in 

more recent rulemakings. See 75 FR 54970 (September 9, 2010), 

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

UPL used in this proposed rule is calculated by: 

Where: 

x ̄ = 2008 annual emissions 

n = the number of test runs 

m = the number of test runs in the compliance average 

s2

 = observed variance 

t = student t distribution statistic 

This calculation was performed using the following Excel 

functions: 

95 percent UPL = 2008 annual emissions + [STDEV(Test Runs) 

x TINV(2 x probability, n-1 degrees of freedom) X 

SQRT((1/n)+(1/m))], for a one-tailed t-value, probability of 

0.05, and sample size of n 

F. What other actions are we proposing? 
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As discussed in Section III.C. above, EPA is proposing to 

remove provisions in the existing standard that would have 

exempted sources from complying with the standard during periods 

of startup, shutdown and malfunction. Specifically we are 

proposing revisions to subpart TTT Table 1 and rule provisions 

to remove applicability of the General Provisions with regard to 

SSM and remove the exemption for bag leak detection alarm time 

attributable to SSM events from determining compliance with the 

total alarm time limit. In addition, we are proposing to 

promulgate an affirmative defense to civil penalties for 

exceedances of emission limits caused by malfunctions, as well 

as criteria for establishing the affirmative defense. 

EPA has attempted to ensure that we have not included in 

the proposed regulatory language any provisions that are 

inappropriate, unnecessary, or redundant in the absence of the 

SSM exemption. We are specifically seeking comment on whether 

there are any such provisions that we have inadvertently 

incorporated or overlooked. 

VI. Proposed Action 

A. What actions are we proposing as a result of the residual 

risk reviews?

 Consistent with CAA section 112 (f)(2), we are proposing to 

amend the MACT standard for primary lead processing to include a 

lead concentration in air limit of 0.15 μg/m3 (based on 3-month 
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Page 130 of 188 

rolling averages)to be measured at locations approved by the 

Administrator to address the risks from all fugitive dust 

emissions addressed in 40 CFR 63.1544. We are also proposing to 

remove refining and casting operations from section 63.1544 and 

to require that emissions from these operations be vented to one 

or more stacks. Finally, we are proposing to establish an 

emission cap of 0.91 TPY for the furnace area stack and the 

refining operation stacks. These limits were established based 

on the level of reductions in lead emissions from the three 

sources that are necessary to show that the lead NAAQS will not 

be exceeded within the 50 km modeled domain. We believe the 

NAAQS level represents an acceptable level of risk and that the 

proposed limits are necessary to ensure that risks from these 

sources are acceptable. We are proposing that the risk posed by 

lead emissions from the main stack and by emissions of all other 

HAP is acceptable. 

 We are proposing that compliance with the emission limits 

applicable to the furnace area and refinery stacks would be 

demonstrated based on stack testing for existing facilities and, 

for new facilities, using CEMS after promulgation of performance 

specifications for a CEMS capable of measuring lead emissions. 

 We are proposing that compliance with the lead 

concentration in air limit would be demonstrated using a 

compliance monitoring system approved by the Administrator. 
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 We are also proposing that the Primary Lead Smelting 

standard, as we have proposed to revise it to ensure an 

acceptable level of risk, will also protect public health with 

an ample margin of safety. With regard to lead emissions from 

fugitive dust sources and from the furnace and refining area 

stacks, we have not identified any feasible controls beyond 

those needed to meet the proposed emission limits that will 

provide an acceptable level of risk . The standards we are 

proposing to ensure an acceptable level of risk for lead 

emissions will also reduce the risk from cadmium and will also 

reduce emissions of all other metal HAP known to be emitted from 

this source category because the controls that will reduce lead 

emissions are the same controls that will reduce emissions of 

these other metal HAP. The cancer risk from cadmium emissions 

will be reduced from 30 in 1-million to less than 1 in 1-

million. Therefore, we are proposing that the existing MACT, as 

it would be modified based on our proposed requirements for lead 

emissions, would provide an ample margin of safety with respect 

to emissions from all metal HAP. 

 With regard to lead emissions from the main stack, we have 

identified developments in practices, processes and control 

technologies since promulgation of the MACT standard in 1999, 

and are proposing a reduced emission limit for the main stack 

based on these improvements. Since the main stack does not pose 
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Page 132 of 188 

an unacceptable risk at its current emissions level, we are not 

proposing reductions for this emission point under 112(f)(2). 

However, we are proposing a reduced emission limit under 

112(d)(6) due to the improvements we identified.

B. What actions are we proposing as a result of the technology 

reviews?

 For the Primary Lead Smelting source category, we have 

determined that there have been developments in practices, 

processes, or control technologies since the promulgation of the 

MACT standards that are feasible for the one facility in this 

source category to implement at the main stack. The proposed 

limit is consistent with the current demonstrated performance of 

the facility based on obligations adopted by the State and 

reflected in the 2002 SIP and 2007 SIP revision for Doe Run. 

 We are proposing that a performance of 15.11 TPY has been 

demonstrated for emissions from the main stack, taking into 

consideration variability of emissions from that stack. The 

existing MACT lead emissions standard that is applicable to 

emissions from the main stack is a plant-wide emission limit 

that also applies to emissions from the furnace-area stack. We 

are proposing to revise the plant-wide limit to reflect the 

15.11 TPY limit for the main stack as well as the emissions 

limits we are proposing for the furnace-area and refinery stacks 

under CAA section 112(f)(2). Thus, we are proposing to revise 
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the plant-wide emissions limit from 1 pound of lead per ton of 

lead produced, to 0.22 pound of lead per ton of lead produced 

and the new limit would include emissions from the refinery 

stack as well as emissions from the main stack and the furnace 

area stack. Compliance with this limit would be demonstrated 

quarterly with stack testing. For new facilities, compliance 

would be demonstrated using lead CEMS. 

 C. What other actions are we proposing? 

As described above, we are proposing to amend the 

applicability section for the MACT rule to tailor it to the 

definition of the source category we established under CAA 

section 112(c)(1). See “Documentation for Development of 

Initial Source Category List – Final Report”, USEPA/OAQPS, EPA450/3-91-030, July, 1992. In support of this applicability 

provision clarification, we are also proposing to replace the 

definition of “primary lead smelter” with a definition of 

“primary lead processor”. The “primary lead processor” 

definition would include any facility that produces lead from 

processing of lead sulfide ore by pyrometallurgical (smelting) 

or any other technique. We are also proposing to add 

definitions of “secondary lead smelters”, “lead refiners”, and 

“lead remelters” to clarify the meaning of those terms in the 

second sentence of the applicability provision. 
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We propose to amend the Primary Lead Smelting MACT 

standards to remove the language that exempts bag leak detection 

system alarm time incurred during periods of SSM from inclusion 

in the allowable alarm time. This change is being made to 

ensure the rule is consistent with the court’s ruling in Sierra 

Club v. EPA, 551 F.3d 1019 (D.C. Cir. 2008). We are also 

proposing minor modifications throughout the rule to incorporate 

plain language and to make editorial and clarifying revisions. 

In addition, we are proposing changes to Table 1 of the rule to 

reflect revisions to SSM requirements. 

D. Compliance Dates

We are proposing that the requirements under CAA section 

112(f)(2) for the one existing source, if finalized, must be 

implemented no later than two years after the effective date of 

this rule. Consistent with CAA section 112(f)(4)(B), we are 

proposing that a two-year compliance period is necessary so the 

facility has adequate time to install additional controls and 

demonstrate compliance, including the time necessary to 

purchase, install and test replacement bags, or if the facility 

decides to add a new baghouse in series with an existing 

baghouse, seek bids, select a vendor, install and test the new 

equipment; prepare and submit the required monitoring plan to 

monitor lead concentrations in air; purchase, install and 

conduct quality assurance and quality control measures on 
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Page 135 of 188 

compliance monitoring equipment and; conduct site remediation 

necessary to reduce fugitive emissions. A two-year compliance 

period is also consistent with the schedule of required actions 

contained in the Consent Decree. 

 In addition, we are proposing that the plant-wide limit 

that would reflect reductions required for the main stack 

pursuant to CAA section 112(d)(6) and for the furnace area and 

refinery stacks pursuant to CAA section 112(f)(2) must be met no 

later than two years after the effective date of this rule. 

Because these limits reflect the reductions from the furnace 

area and refinery stacks required under section 112(f)(2), we 

believe a two-year compliance timeframe is needed for the same 

reasons provided above. 

VII. Request for Comments 

We are soliciting comments on all aspects of this proposed 

action. All comments received during the comment period will be 

considered. In addition to general comments on the proposed 

actions, we are also interested in any additional data that may 

help to reduce the uncertainties inherent in the risk 

assessments. We are specifically interested in receiving 

corrections to the dataset used for risk modeling. Such data 

should include supporting documentation in sufficient detail to 

allow characterization of the quality and representativeness of 
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Page 136 of 188 

the data or information. Please see the following section for 

more information on submitting data. 

VIII. Submitting Data Corrections 

The facility-specific data used in the source category risk 

analyses and demographic analyses are available for download on 

the RTR Web Page at http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. 

The data files include detailed information for each HAP 

emissions release point for the facility included in the source 

category. 

If you believe the data are not representative or are 

inaccurate, please identify the data in question, provide your 

reason for concern, and provide any “improved” data that you 

have, if available. When you submit data, we request that you 

provide documentation of the basis for the revised values to 

support your suggested changes. To submit comments on the data 

downloaded from the RTR Web page, complete the following steps: 

1) Within this downloaded file, enter suggested revisions 

to the data fields appropriate for that information. The data 

fields that may be revised include the following: 

Data Element Definition 

Control Measure Are control measures in place? 

(yes or no) 

Control Measure Comment 

Select control measure from 

list provided, and briefly 

describe the control measure 

Delete Indicate here if the facility 

or record should be deleted 
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Data Element Definition

Delete Comment Describes the reason for 

deletion 

Emission Calculation 

Method Code For Revised 

Emissions 

Code description of the method 

used to derive emissions. For 

example, CEM, material 

balance, stack test, etc.

Emission Process Group 

Enter the general type of 

emission process associated 

with the specified emission 

point 

Fugitive Angle 

Enter release angle (clockwise 

from true North); orientation 

of the y-dimension relative to 

true North, measured positive 

for clockwise starting at 0 

degrees (maximum 89 degrees) 

Fugitive Length 

Enter dimension of the source 

in the east-west (x-) 

direction, commonly referred 

to as length (ft) 

Fugitive Width 

Enter dimension of the source 

in the north-south (y-) 

direction, commonly referred 

to as width (ft) 

Malfunction Emissions Enter total annual emissions 

due to malfunctions (TPY) 

Malfunction Emissions Max 

Hourly 

Enter maximum hourly 

malfunction emissions here 

(lb/hr) 

North American Datum 

Enter datum for 

latitude/longitude coordinates 

(NAD27 or NAD83); if left 

blank, NAD83 is assumed 

Process Comment Enter general comments about 

process sources of emissions 

REVISED Address Enter revised physical street 

address for MACT facility here 

REVISED City Enter revised city name here

REVISED County Name Enter revised county name here 

REVISED Emission Release 

Point Type 

Enter revised Emission Release 

Point Type here 

REVISED End Date Enter revised End Date here 

REVISED Exit Gas Flow Rate Enter revised Exit Gas 

Flowrate here (ft3

/sec) 
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Data Element Definition

REVISED Exit Gas 

Temperature 

Enter revised Exit Gas 

Temperature here (F) 

REVISED Exit Gas Velocity Enter revised Exit Gas 

Velocity here (ft/sec) 

REVISED Facility Category 

Code 

Enter revised Facility 

Category Code here, which 

indicates whether facility is 

a major or area source 

REVISED Facility Name Enter revised Facility Name 

here

REVISED Facility Registry 

Identifier 

Enter revised Facility 

Registry Identifier here, 

which is an ID assigned by the 

EPA Facility Registry System 

REVISED HAP Emissions 

Performance Level Code 

Enter revised HAP Emissions 

Performance Level here 

REVISED Latitude Enter revised Latitude here 

(decimal degrees) 

REVISED Longitude Enter revised Longitude here 

(decimal degrees) 

REVISED MACT Code Enter revised MACT Code here 

REVISED Pollutant Code Enter revised Pollutant Code 

here 

REVISED Routine Emissions Enter revised routine 

emissions value here (TPY) 

REVISED SCC Code Enter revised SCC Code here 

REVISED Stack Diameter Enter revised Stack Diameter 

here (ft)

REVISED Stack Height Enter revised Stack Height 

here (Ft) 

REVISED Start Date Enter revised Start Date here 

REVISED State Enter revised State here 

REVISED Tribal Code Enter revised Tribal Code here 

REVISED Zip Code Enter revised Zip Code here 

Shutdown Emissions Enter total annual emissions 

due to shutdown events (TPY) 

Shutdown Emissions Max 

Hourly 

Enter maximum hourly shutdown 

emissions here (lb/hr) 

Stack Comment Enter general comments about 

emission release points 

Startup Emissions Enter total annual emissions 

due to startup events (TPY) 

Startup Emissions Max 

Hourly 

Enter maximum hourly startup 

emissions here (lb/hr) 
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Data Element Definition

Year Closed Enter date facility stopped 

operations 

2. Fill in the commenter information fields for each 

suggested revision (i.e., commenter name, commenter 

organization, commenter e-mail address, commenter phone number, 

and revision comments). 

3. Gather documentation for any suggested emissions 

revisions (e.g., performance test reports, material balance 

calculations, etc.). 

4. Send the entire downloaded file with suggested 

revisions in Microsoft® Access format and all accompanying 

documentation to Docket ID Number EPA-HQ-OAR-2004-0305 (through 

one of the methods described in the ADDRESSES section of this 

preamble). To expedite review of the revisions, it would also 

be helpful if you submitted a copy of your revisions to the EPA 

directly at RTR@epa.gov in addition to submitting them to the 

docket. 

5. If you are providing comments on a facility, you need 

only submit one file for that facility, which should contain all 

suggested changes for all sources at that facility. We request 

that all data revision comments be submitted in the form of 

updated Microsoft® Access files, which are provided on the 

http://www.epa.gov/ttn/atw/rrisk/rtrpg.html Web page. 
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IX. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review. 

Under Executive Order 12866 (58 FR 51735, October 4, 1993), 

this action is a significant regulatory action because it raises 

novel legal and policy issues. Accordingly, EPA submitted this 

action to the Office of Management and Budget (OMB) for review 

under Executive Order 12866 and any changes made in response to 

OMB recommendations have been documented in the docket for this 

action. 

B. Paperwork Reduction Act. 

The information collection requirements in this rule 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 2424.01. 

We are proposing new paperwork requirements to the Primary 

Lead Smelting source category in the form of monitoring for lead 

concentrations in air and increased frequency for stack testing 

as described in 40 CFR 63.1547(k) (compliance monitoring) and 40 

CFR 63.1546 (stack testing). These requirements are described 

in section VI.A and B. Although these are additional 

requirements under today’s proposed rule, they are consistent 

with existing monitoring and testing currently conducted by the 

facility to meet MACT and SIP requirements. Therefore, we do 
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Page 141 of 188 

not believe that the additional paperwork required by these 

proposed changes would constitute an undue burden to the 

facility. 

We estimate one regulated entity is currently subject to 

subpart TTT and will be subject to all proposed standards. This 

facility will have no capital costs associated with the 

information collection requirements in the proposed rule. 

The estimated recordkeeping and reporting burden after the 

effective date of the proposed rule is estimated to be 1,323 

labor hours at a cost of $465,503. This estimate includes the 

cost of reporting, including reading instructions, and 

information gathering. Recordkeeping cost estimates include 

reading instructions, planning activities, monitoring plan 

development, conducting compliance monitoring, sampling and 

analysis and maintenance of rolling 3-month average data. The 

average hours and cost per regulated entity would be 1,323 hours 

and $465,503 based on one facility response 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 in 40 CFR are listed in 40 CFR 

part 9. 

To comment on the Agency's need for this information, the 
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accuracy of the provided burden estimates, and any suggested 

methods for minimizing respondent burden, EPA has established a 

public docket for this rule, which includes this ICR, under 

Docket ID number EPA-HQ-OAR-2004-0305. Submit any comments 

related to the ICR to EPA and OMB. See ADDRESSES section at the 

beginning of this notice for where to submit comments to EPA. 

Send comments to OMB at the Office of Information and Regulatory 

Affairs, Office of Management and Budget, 725 17th Street, NW, 

Washington, DC 20503, Attention: Desk Office for EPA. Since OMB 

is required to make a decision concerning the ICR between 30 and 

60 days after [Insert date of publication in the Federal 

Register.], a comment to OMB is best assured of having its full 

effect if OMB receives it by [Insert date 30 days after 

publication in the Federal Register.]. The final rule will 

respond to any OMB or public comments on the information 

collection requirements contained in this proposal. 

C. Regulatory Flexibility Act. 

The Regulatory Flexibility Act (RFA) generally requires an 

agency to prepare a regulatory flexibility analysis of any rule 

subject to notice and comment rulemaking requirements under the 

Administrative Procedure Act or any other statute unless the 

agency certifies that the rule will not have a significant 

economic impact on a substantial number of small entities. 

Small entities include small businesses, small organizations, 
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and small governmental jurisdictions. For purposes of assessing 

the impacts of today’s proposed rule on small entities, small 

entity is defined as: (1) A small business that is a small 

industrial entity as defined by the Small Business 

Administration’s (SBA) regulations at 13 CFR 121.201; (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. 

This proposed rule is currently applicable to one operating 

facility that does not meet the definition of a small entity. 

After considering the economic impacts of today’s proposed 

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

a significant economic impact on a substantial number of small 

entities. 

We continue to be interested in the potential impacts of 

the proposed rule on small entities and welcome comments on 

issues related to such impacts. 

D. Unfunded Mandates Reform Act. 

This proposed rule does not contain a federal mandate under 

the provisions of Title II of the Unfunded Mandates Reform Act 

of 1995 (UMRA), 2 U.S.C. 1531-1538 for State, local, or tribal 

governments or the private sector. The proposed rule would not 
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result in expenditures of $100 million or more for State, local, 

and tribal governments, in aggregate, or the private sector in 

any 1 year. The proposed rule imposes no enforceable duties on 

any State, local or tribal governments or the private sector. 

Thus, this proposed rule is not subject to the requirements of 

sections 202 or 205 of the UMRA. 

This proposed rule is also not subject to the requirements 

of section 203 of UMRA because it contains no regulatory 

requirements that might significantly or uniquely affect small 

governments because it contains no requirements that apply to 

such governments nor does it impose obligations upon them. 

E. Executive Order 13132: Federalism. 

This proposed rule does not have federalism implications. 

It will not have substantial direct effects on the States, on 

the relationship between the national government and the States, 

or on the distribution of power and responsibilities among the 

various levels of government, as specified in Executive Order 

13132. None of the facilities subject to this action are owned 

or operated by State governments, and, because no new 

requirements are being promulgated, nothing in this proposal 

will supersede State regulations. Thus, Executive Order 13132 

does not apply to this proposed rule. 

In the spirit of Executive Order 13132, and consistent with 

EPA policy to promote communications between EPA and State and 
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Page 145 of 188 

local governments, EPA specifically solicits comment on this 

proposed rule from State and local officials. 

F. Executive Order 13175: Consultation and Coordination with 

Indian Tribal Governments. 

Subject to the Executive Order 13175 (65 FR 67249, November 

9, 2000) EPA may not issue a regulation that has tribal 

implications, that imposes substantial direct compliance costs, 

and that is not required by statute, unless the federal 

government provides the funds necessary to pay the direct 

compliance costs incurred by tribal governments, or EPA consults 

with tribal officials early in the process of developing the 

proposed regulation and develops a tribal summary impact 

statement. EPA has concluded that this proposed rule will not 

have tribal implications, as specified in Executive Order 13175. 

It will not have substantial direct effect 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. Thus, Executive 

Order 13175 does not apply to this action. 

EPA specifically solicits additional comment on this 

proposed action from tribal officials. 

G. Executive Order 13045: Protection of Children from 

Environmental Health Risks and Safety Risks. 
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This proposed rule is not subject to Executive Order 13045 

(62 FR 19885, April 23, 1997) because it is not economically 

significant as defined in Executive Order 12866. However, the 

Agency does believe there is a disproportionate risk to 

children. Modeled ambient air lead concentrations from the one 

facility in this source category are in excess of the NAAQS for 

lead, which was set to “provide increased protection for 

children and other at-risk populations against an array of 

adverse health effects, most notably including neurological 

effects in children, including neurocognitive and 

neurobehavioral effects.” 73 FR 67007. However, the control 

measures proposed in this notice will result in lead 

concentration levels that are in compliance with the lead NAAQS, 

thereby mitigating the risk of adverse health effects to 

children.

H. Executive Order 13211: Actions Concerning Regulations That 

Significantly Affect Energy Supply, Distribution, or Use. 

 This action is not a “significant energy action” as defined 

under Executive Order 13211, “Actions Concerning Regulations 

That Significantly Affect Energy Supply, Distribution, or Use” 

(66 FR 28355, May 22, 2001), because it is not likely to have 

significant adverse effect on the supply, distribution, or use 
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of energy. This action will not create any new requirements for 

sources in the energy supply, distribution, or use sectors. 

I. National Technology Transfer and Advancement Act. 

 Section 12(d) of the National Technology Transfer and 

Advancement Act of 1995 (“NTTAA”), Public Law Number 104-113, 

12(d) (15 U.S.C. 272 note) directs EPA to use voluntary 

consensus standards in its regulatory activities unless to do so 

would be inconsistent with applicable law or otherwise 

impractical. Voluntary consensus standards are technical 

standards (e.g., materials specifications, test methods, 

sampling procedures, and business practices) that are developed 

or adopted by voluntary consensus standards bodies. The NTTAA 

directs EPA to provide Congress, through OMB, explanations when 

the Agency decides not to use available and applicable voluntary 

consensus standards. 

 This proposed rulemaking does not involve technical 

standards. Therefore, EPA is not considering the use of any 

voluntary consensus standards. 

J. Executive Order 12898: Federal Actions to Address 

Environmental Justice in Minority Populations and Low-Income 

Populations. 

Executive Order 12898 (59 FR 7629, February 16, 1994) 

establishes federal executive policy on environmental justice. 

Its main provision directs federal agencies, to the greatest 
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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. 

To examine the potential for any environmental justice 

issues that might be associated with each source category, we 

evaluated the distributions of HAP-related cancer and non-cancer 

risks across different social, demographic, and economic groups 

within the populations living near the facilities where these 

source categories are located. The methods used to conduct 

demographic analyses for this rule are described in section IV.A 

of the preamble for this rule. The development of demographic 

analyses to inform the consideration of environmental justice 

issues in EPA rulemakings is an evolving science. The EPA 

offers the demographic analyses in today’s rulemaking as 

examples of how such analyses might be developed to inform such 

consideration, and invites public comment on the approaches used 

and the interpretations made from the results, with the hope 

that this will support the refinement and improve utility of 

such analyses for future rulemakings. 

In the case of Primary Lead Processing, we focused on 

populations within 50 km of the one facility in this source 
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category with emission sources subject to the MACT standard. 

More specifically, for these populations we evaluated exposures 

to HAP which could result in cancer risks of 1-in-1 million or 

greater, or population exposures to ambient air lead 

concentrations above the level of the NAAQS for lead. We 

compared the percentages of particular demographic groups within 

the focused populations to the total percentages of those 

demographic groups nationwide. The results of this analysis are 

documented in section V.B.1 (see Table 6), as well as in a 

technical report located in the docket for this rulemaking. In 

brief, although our analyses show that there is the potential 

for adverse environmental and human health effects from 

emissions of lead, it does not indicate any significant 

potential for disparate impacts to the specific demographic 

groups analyzed (see section V.B.1). Notably however, the 

proposed rule would require additional control measures to 

address the identified environmental and health risks and would 

therefore, decrease risks to any populations exposed to these 

sources. 
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National Emission Standards for Hazardous Air Pollutant 

Emissions: Primary Lead Smelting 

Page 150 of 188 

 

List of Subjects in 40 CFR Part 63

 Environmental protection, Air pollution control, Reporting 

and recordkeeping requirements, Lead. 

____________________________ 

Dated: 

____________________________ 

Lisa P. Jackson, 

Administrator. 
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 For reasons set out in the preamble, title 40, chapter I, of 

the Code of Federal Regulations is amended as 

follows: 

PART 63--[AMENDED]

1. The authority citation for part 63 continues to read as 

follows: 

 Authority: 42 U.S.C. 7401 et seq. 

2. Section 63.1541 is revised to read as follows: 

§63.1541 Applicability.

 (a) The provisions of this subpart apply to any facility 

engaged in producing lead metal from ore concentrates. The 

category includes, but is not limited to, the following smelting 

processes: sintering, reduction, preliminary treatment, refining 

and casting operations, process fugitive sources, and fugitive 

dust sources. The sinter process includes an updraft or 

downdraft sintering machine. The reduction process includes the 

blast furnace, electric smelting furnace with a converter or 

reverberatory furnace, and slag fuming furnace process units. 

The preliminary treatment process includes the drossing kettles 

and dross reverberatory furnace process units. The refining 

process includes the refinery process unit. The provisions of 

this subpart do not apply to secondary lead smelters, lead 

refiners, or lead remelters. 
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 (b) Table 1 of this subpart specifies the provisions of 

subpart A of this part that apply and those that do not apply to 

owners and operators of primary lead processors. 

3. Section 63.1542 is amended by adding a definition for 

“Affirmative defense,” “Lead refiner,” “Lead remelter,” “Primary 

lead processor, and “Secondary lead smelter;” ”deleting the 

definition of “Primary lead smelter;” and revising the 

definitions of ”Fugitive dust source,” “Furnace area,” 

“Malfunction,” “Materials storage and handling area,” “Plant 

roadway,” “Process fugitive source,” “Refining and casting 

area,” Sinter machine area,” and “Tapping location” to read as 

follows: 

§63.1542 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. 

* * * * * 

 Fugitive dust source means a stationary source of hazardous 

air pollutant emissions at a primary lead processor resulting 

from the handling, storage, transfer, or other management of 
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lead-bearing materials where the source is not part of a 

specific process, process vent, or stack. Fugitive dust sources 

include roadways, storage piles, materials handling transfer 

points, and materials transport areas. 

 Furnace area means any area of a primary lead processor in 

which a blast furnace or dross furnace is located. 

 Lead refiner means any facility that refines lead metal that 

is not located at a primary lead processor. 

 Lead remelter means any facility that remelts lead metal 

that is not located at a primary lead processor. 

 Malfunction means any 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 which causes, or has the potential to 

cause, the emission limitations in an applicable standard to be 

exceeded. Failures that are caused in part by poor maintenance 

or careless operation are not malfunctions. 

 Materials storage and handling area means any area of a 

primary lead processor in which lead-bearing materials 

(including ore concentrate, sinter, granulated lead, dross, 

slag, and flue dust) are stored or handled between process 

steps, including areas in which materials are stored in piles, 

bins, or tubs, and areas in which material is prepared for 
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charging to a sinter machine or smelting furnace or other lead 

processing operation. 

* * * * * 

 Plant roadway means any area of a primary lead processor 

that is subject to vehicle traffic, including traffic by 

forklifts, front-end loaders, or vehicles carrying ore 

concentrates or cast lead ingots. Excluded from this definition 

are employee and visitor parking areas, provided they are not 

subject to traffic by vehicles carrying lead-bearing materials. 

 Primary lead processor means any facility engaged in the 

production of lead metal from lead sulfide ore concentrates 

through the use of pyrometallurgical or other techniques. 

 Process fugitive source means a source of hazardous air 

pollutant emissions at a primary lead processor that is 

associated with lead smelting, processing or refining but is not 

the primary exhaust stream and is not a fugitive dust source. 

Process fugitive sources include sinter machine charging 

locations, sinter machine discharge locations, sinter crushing 

and sizing equipment, furnace charging locations, furnace taps, 

and drossing kettle and refining kettle charging or tapping 

locations. 

 Refining and casting area means any area of a primary lead 
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processor in which drossing or refining operations occur, or 

casting operations occur. 

 Secondary lead smelter means any facility at which leadbearing scrap material, primarily, but not limited to, lead-acid 

batteries, is recycled into elemental lead or lead alloys by 

smelting. 

 

* * * * * 

 Sinter machine area means any area of a primary lead 

processor where a sinter machine, or sinter crushing and sizing 

equipment is located. 

* * * * * 

 Tapping location means the opening through which lead and 

slag are removed from the furnace. 

4. Section 63.1543 is revised to read as follows: 

§63.1543 Standards for process and process fugitive sources.

 (a) No owner or operator of any existing, new, or 

reconstructed primary lead processor shall discharge or cause to 

be discharged into the atmosphere lead compounds in excess of 

0.22 pounds per ton of lead metal produced from the aggregation 

of emissions discharged from air pollution control devices used 

to control emissions at primary lead processing facilities, 

including the sources listed in paragraphs (a)(1) through 
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(a)(10) of this section. 

 (1) Sinter machine; 

 (2) Blast furnace; 

 (3) Dross furnace; 

 (4) Dross furnace charging location; 

 (5) Blast furnace and dross furnace tapping location; 

 (6) Sinter machine charging location; 

 (7) Sinter machine discharge end; 

 (8) Sinter crushing and sizing equipment; 

 (9) Sinter machine area; and 

 (10) Refining and casting, and furnace area. 

 (b) No owner or operator of any existing, new, or 

reconstructed primary lead processor shall discharge or cause to 

be discharged into the atmosphere lead compounds in excess of 

0.91 tons per year from the air pollution control devices used 

to control emissions from furnace area and refining and casting 

operations. 

 (c) The process fugitive sources listed in paragraphs 

(a)(4) through (a)(8) of this section must be equipped with a 

hood and must be ventilated to a baghouse or equivalent control 

device. The hood design and ventilation rate must be consistent 

with American Conference of Governmental Industrial Hygienists 

recommended practices. 
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 (d) The sinter machine area must be enclosed in a building 

that is ventilated to a baghouse or equivalent control device at 

a rate that maintains a positive in-draft through any doorway 

opening. 

 (e) Except as provided in paragraph (f) of this section, 

following the initial tests to demonstrate compliance with 

paragraphs (a)and (b) of this section, the owner or operator of 

a primary lead processor must conduct compliance tests for lead 

compounds on an quarterly basis (no later than 100 days 

following any previous compliance test). 

 (f) If the 12 most recent compliance tests demonstrate 

compliance with the emission limit specified in paragraphs (a) 

and (b) of this section, the owner or operator of a primary lead 

processor shall be allowed up to 12 calendar months from the 

last compliance test to conduct the next compliance test for 

lead compounds. 

 (g) The owner or operator of a primary lead processor must 

maintain and operate each baghouse used to control emissions 

from the sources listed in paragraphs (a)(1) through (a)(10) of 

this section such that the alarm on a bag leak detection system 

required under §63.1547(c)(8) does not sound for more than five 

percent of the total operating time in a 6-month reporting 

period. 
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 (h) The owner or operator of a primary lead processor must 

record the date and time of a bag leak detection system alarm 

and initiate procedures to determine the cause of the alarm 

according to the corrective action plan required under 

§63.1547(f) within 1 hour of the alarm. The cause of the alarm 

must be corrected as soon as practicable. 

 (i) At all times, the owner or operator 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. 

5. Section 63.1544 is revised to read as follows: 

§63.1544 Standards for fugitive dust sources. 

 (a) No owner or operator of any existing, new or 

reconstructed primary lead processor shall discharge or cause to 

be discharged into the atmosphere lead compounds that cause the 

concentration of lead in air to exceed 0.15 μg/m3

 on a 3-month 

rolling average measured at locations approved by the 
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Administrator. 

 (b) At all times, the owner or operator 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. 

6. Section 63.1545 is revised to read as follows: 

§63.1545 Compliance dates. 

 (a) Each owner or operator of an existing primary lead 

processor must achieve compliance with the requirements of this 

subpart no later than [INSERT DATE TWO YEARS FROM THE DATE OF 

PUBLICATION OF THESE AMENDMENTS IN THE FEDERAL REGISTER]. 

 (b) Each owner or operator of a new primary lead processor 

must achieve compliance with the requirements of this subpart no 

later than [INSERT DATE 60 DAYS AFTER PUBLICATION OF THESE 

AMENDMENTS IN THE FERERAL REGISTER] or startup, whichever is 

later. 

7. Section 63.1546 is revised to read as follows: 
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§63.1546 Performance testing.

 (a) The following procedures must be used to determine 

quarterly compliance with the emissions standard for lead 

compounds under §63.1543(a) and (b) for existing sources: 

 (1) Each owner or operator of existing sources listed in 

§63.1543(a)(1) through (10) must determine the lead compound 

emissions rate, in units of pounds of lead per hour according to 

the following test methods in appendix A of part 60 of this 

chapter: 

 (i) Method 1 must be used to select the sampling port 

location and the number of traverse points. 

 (ii) Method 2, 2F, 2G must be used to measure volumetric 

flow rate. 

 (iii) Method 3, 3A, 3B must be used for gas analysis. 

 (iv) Method 4 must be used to determine moisture content of 

the stack gas. 

 (v) Method 12 or Method 29 must be used to determine lead 

emissions rate of the stack gas. 

 (2) A performance test shall consist of at least three 

runs. For each test run with Method 12 or Method 29, the 

minimum sample time must be 60 minutes and the minimum volume 

must be 1 dry standard cubic meter (35 dry standard cubic feet). 

 (3) Performance tests shall be completed quarterly, once 
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every 3 months, to determine compliance. 

 (4) The lead emission rate in pounds per quarter is 

calculated by multiplying the quarterly lead emission rate in 

pounds per hour by the quarterly plant operating time, in hours 

as shown in Equation 1: 

 (Eq. 1) 

Where: 

 EPb = quarterly lead emissions, pounds per quarter; 

 ERPb = quarterly lead emissions rate, pounds per hour; and 

 QPOT = quarterly plant operating time, hours per quarter. 

 (5) The lead production rate, in units of tons per 

quarter, must be determined based on production data for the 

previous quarter according to the procedures detailed in 

paragraphs (a)(3)(i) through (iv) of this section: 

 (i) Total lead products production multiplied by the 

fractional lead content must be determined in units of tons. 

 (ii) Total copper matte production multiplied by the 

fractional lead content must be determined in units of tons. 

 (iii) Total copper speiss production multiplied by the 

fractional lead content must be determined in units of tons. 

 (iv) Total quarterly lead production must be determined by 

summing the values obtained in paragraphs (a)(3)(i) through 

(a)(3)(iii) of this section. 
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 (6) To determine compliance with the production-based lead 

compound emission rate in §63.1543(a), the quarterly productionbased lead compound emission rate, in units of pounds of lead 

emissions per ton of lead produced, is calculated as shown in 

Equation 2 by dividing lead emissions by lead production. 

 (Eq. 2) 

Where : 

 CEPb = quarterly production-based lead compound emission 

rate, in units of pounds of lead emissions per ton of lead 

produced; 

 EPb = quarterly lead emissions, pounds per quarter; and 

 PPb = quarterly lead production, tons per quarter. 

 (7) To determine quarterly compliance with the emissions 

standard for lead compounds under §63.1543(b), sum the lead 

compound emission rates for the current and previous three 

quarters for the sources in §63.1543 (a)(10) to determine 

compliance with §63.1543(b), as determined in accordance with 

paragraphs (a)(1) through (a)(4) of this section. 

 (b) Owner and operators must perform an initial compliance 

test to demonstrate compliance with the sinter building in-draft 

requirements of Sec. 63.1543(d) at each doorway opening in 

accordance with paragraphs (b)(1) through (b)(4) of this 
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section. 

 (1) Use a propeller anemometer or equivalent device. 

 (2) Determine doorway in-draft by placing the anemometer in 

the plane of the doorway opening near its center. 

 (3) Determine doorway in-draft for each doorway that is 

open during normal operation with all remaining doorways in 

their customary position during normal operation. 

 (4) Do not determine doorway in-draft when ambient wind 

speed exceeds 2 meters per second. 

(c) Performance tests shall be conducted under such 

conditions as the Administrator specifies to the owner or 

operator based on representative performance 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. 

8. Section 63.1547 is revised to read as follows: 

§63.1547 Monitoring requirements. 

 (a) Owners and operators of primary lead processors must 

prepare, and at all times operate according to, a standard 

operating procedures manual that describes in detail the 

procedures for inspection, maintenance, and bag leak detection 

and corrective action for all baghouses that are used to control 
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process, process fugitive, or fugitive dust emissions from any 

source subject to the lead emission standards in §§63.1543 and 

63.1544, including those used to control emissions from general 

ventilation systems. 

 (b) The standard operating procedures manual for baghouses 

required by paragraph (a) of this section must be submitted to 

the Administrator or delegated authority for review and 

approval. 

 (c) The procedures specified in the standard operating 

procedures manual for inspections and routine maintenance must, 

at a minimum, include the requirements of paragraphs (c)(1) 

through (c)(8) of this section. 

 (1) Weekly confirmation that dust is being removed from 

hoppers through visual inspection or equivalent means of 

ensuring the proper functioning of removal mechanisms. 

 (2) Daily check of compressed air supply for pulse-jet 

baghouses. 

 (3) An appropriate methodology for monitoring cleaning 

cycles to ensure proper operation. 

 (4) Monthly check of bag cleaning mechanisms for proper 

functioning through visual inspection or equivalent means. 

 (5) Quarterly visual check of bag tension on reverse air 

and shaker-type baghouses to ensure that bags are not kinked 
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(kneed or bent) or laying on their sides. Such checks are not 

required for shaker-type baghouses using self-tensioning (spring 

loaded) devices. 

 (6) Quarterly confirmation of the physical integrity of the 

baghouse through visual inspection of the baghouse interior for 

air leaks. 

 (7) Quarterly inspection of fans for wear, material 

buildup, and corrosion through visual inspection, vibration 

detectors, or equivalent means. 

 (8) Except as provided in paragraph (h) of this section, 

continuous operation of a bag leak detection system. 

 (d) The procedures specified in the standard operating 

procedures manual for maintenance must, at a minimum, include a 

preventative maintenance schedule that is consistent with the 

baghouse manufacturer's instructions for routine and long-term 

maintenance. 

 (e) The bag leak detection system required by paragraph 

(c)(9) of this section must meet the specifications and 

requirements of (e)(1) through (e)(8) of this section. 

 (1) The bag leak detection system must be certified by the 

manufacturer to be capable of detecting particulate matter 

emissions at concentrations of 10 milligram per actual cubic 

meter (0.0044 grains per actual cubic foot) or less. 
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 (2) The bag leak detection system sensor must provide 

output of relative particulate matter loadings, and the owner or 

operator must continuously record the output from the bag leak 

detection system. 

 (3) The bag leak detection system must be equipped with an 

alarm system that will sound when an increase in relative 

particulate loading is detected over a preset level, and the 

alarm must be located such that it can be heard or otherwise 

determined by the appropriate plant personnel. 

 (4) Each bag leak detection system that works based on the 

triboelectric effect must be installed, calibrated, and 

maintained in a manner consistent with guidance provided in the 

U.S. Environmental Protection Agency guidance document ”Fabric 

Filter Bag Leak Detection Guidance” (EPA-454/R-98-015). Other 

bag leak detection systems must be installed, calibrated, and 

maintained in a manner consistent with the manufacturer's 

written specifications and recommendations. 

 (5) The initial adjustment of the system must, at a 

minimum, consist of establishing the baseline output by 

adjusting the sensitivity (range) and the averaging period of 

the device, and establishing the alarm set points and the alarm 

delay time. 

 (6) Following initial adjustment, the owner or operator 
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must not adjust the sensitivity or range, averaging period, 

alarm set points, or alarm delay time, except as detailed in the 

approved SOP required under paragraph (a) of this section. In no 

event shall the sensitivity be increased by more than 100 

percent or decreased more than 50 percent over a 365-day period 

unless a responsible official certifies that the baghouse has 

been inspected and found to be in good operating condition. 

 (7) For negative pressure, induced air baghouses, and 

positive pressure baghouses that are discharged to the 

atmosphere through a stack, the bag leak detector must be 

installed downstream of the baghouse and upstream of any wet 

acid gas scrubber. 

 (8) Where multiple detectors are required, the system's 

instrumentation and alarm may be shared among detectors. 

 (f) The standard operating procedures manual required by 

paragraph (a) of this section must include a corrective action 

plan that specifies the procedures to be followed in the event 

of a bag leak detection system alarm. The corrective action plan 

must include at a minimum, procedures to be used to determine 

the cause of an alarm, as well as actions to be taken to 

minimize emissions, which may include, but are not limited to, 

the following. 

 (1) Inspecting the baghouse for air leaks, torn or broken 
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bags or filter media, or any other condition that may cause an 

increase in emissions. 

 (2) Sealing off defective bags or filter media. 

 (3) Replacing defective bags or filter media, or otherwise 

repairing the control device. 

 (4) Sealing off a defective baghouse compartment. 

 (5) Cleaning the bag leak detection system probe, or 

otherwise repairing or maintaining the bag leak detection 

system. 

 (6) Shutting down the process producing the particulate 

emissions. 

 (g) The percentage of total operating time the alarm on the 

bag leak detection system sounds in a 6-month reporting period 

must be calculated in order to determine compliance with the 

five percent operating limit in Sec. 63.1543(h). The percentage 

of time the alarm on the bag leak detection system sounds must 

be determined according to paragraphs (g)(1) through (g)(3) of 

this section. 

 (1) For each alarm where the owner or operator initiates 

procedures to determine the cause of an alarm within 1 hour of 

the alarm, 1 hour of alarm time must be counted. 

 (2) For each alarm where the owner or operator does not 

initiate procedures to determine the cause of the alarm within 1 
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hour of the alarm, alarm time will be counted as the actual 

amount of time taken by the owner or operator to initiate 

procedures to determine the cause of the alarm. 

 (3) The percentage of time the alarm on the bag leak 

detection system sounds must be calculated as the ratio of the 

sum of alarm times to the total operating time multiplied by 

100. 

 (h) Baghouses equipped with HEPA filters as a secondary 

filter used to control process or process fugitive sources 

subject to the lead emission standards in Sec. 63.1543 are 

exempt from the requirement in paragraph (c)(9) of this section 

to be equipped with a bag leak detector. The owner or operator 

of an affected source that uses a HEPA filter must monitor and 

record the pressure drop across the HEPA filter system daily. If 

the pressure drop is outside the limit(s) specified by the 

filter manufacturer, the owner or operator must take appropriate 

corrective measures, which may include, but not be limited to, 

the following: 

 (1) Inspecting the filter and filter housing for air leaks 

and torn or broken filters. 

 (2) Replacing defective filter media, or otherwise 

repairing the control device. 

 (3) Sealing off a defective control device by routing air 
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to other comparable control devices. 

 (4) Shutting down the process producing the particulate 

emissions. 

 (i) Owners and operators must monitor sinter machine 

building in-draft to demonstrate continued compliance with the 

operating standard specified in Sec. 63.1543(d) in accordance 

with either paragraph (i)(1), (i)(2), or (i)(3) of this section. 

 (1) Owners and operators must check and record on a daily 

basis doorway in-draft at each doorway in accordance with the 

methodology specified in Sec. 63.1546(b). 

 (2) Owners and operators must establish and maintain 

baseline ventilation parameters which result in a positive indraft according to paragraphs (i)(2)(i) through (i)(2)(iv) of 

this section. 

 (i) Owners and operators must install, calibrate, maintain, 

and operate a monitoring device that continuously records the 

volumetric flow rate through each separately ducted hood; or 

install, calibrate, maintain, and operate a monitoring device 

that continuously records the volumetric flow rate at the 

control device inlet of each exhaust system ventilating the 

building. The flow rate monitoring device(s) can be installed in 

any location in the exhaust duct such that reproducible flow 

rate measurements will result. The flow rate monitoring 
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device(s) must have an accuracy of plus or minus 10 percent over 

the normal process operating range and must be calibrated 

according to manufacturer's instructions. 

 (ii) During the initial demonstration of sinter building 

in-draft, and at any time the owner or operator wishes to reestablish the baseline ventilation parameters, the owner or 

operator must continuously record the volumetric flow rate 

through each separately ducted hood, or continuously record the 

volumetric flow rate at the control device inlet of each exhaust 

system ventilating the building and record exhaust system damper 

positions. The owner or operator must determine the average 

volumetric flow rate(s) corresponding to the period of time the 

in-draft compliance determinations are being conducted. 

 (iii) The owner or operator must maintain the volumetric 

flow rate(s) at or above the value(s) established during the 

most recent in-draft determination at all times the sinter 

machine is in operation. Volumetric flow rate(s) must be 

calculated as a 15-minute average. 

 (iv) If the volumetric flow rate is monitored at the 

control device inlet, the owner or operator must check and 

record damper positions daily to ensure they are in the 

positions they were in during the most recent in-draft 

determination. 
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 (3) An owner or operator may request an alternative 

monitoring method by following the procedures and requirements 

in §63.8(f) of the General Provisions. 

 (j) Each owner or operator of new or modified sources 

listed under §63.1543 (a)(1) through (a)(10) must install, 

calibrate, maintain, and operate a continuous emission 

monitoring system (CEMS) for measuring lead emissions and a 

continuous emission rate monitoring system (CERMS)subject to 

Performance Specification 6 of Appendix B to part 60. 

 (1) Each owner or operator of a source subject to the 

emissions limits for lead compounds under §63.1543(a)and (b) 

must install a CEMS for measuring lead emissions within 180 days 

of promulgation of performance specifications for lead CEMS. 

 (i) Prior to promulgation of performance specifications for 

CEMS used to measure lead concentrations, an owner or operator 

must use the procedure described in §63.1546 (a)(1) through 

(a)(7) of this section to determine compliance. 

(2) If a CEMS used to measure lead emissions is applicable, 

the owner or operator must install a CERMS with a sensor in a 

location that provides representative measurement of the exhaust 

gas flow rate at the sampling location of the CEMS used to 

measure lead emissions, taking into account the manufacturer’s 

recommendations. The flow rate sensor is that portion of the 
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system that senses the volumetric flow rate and generates an 

output proportional to that flow rate. 

(i) The CERMS must be designed to measure the exhaust gas 

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 gas flow rate. 

(ii) The CERMS must be equipped with a data acquisition and 

recording system that is capable of recording values over the 

entire range specified in paragraph (b)(2)(i) of this section. 

(iii) Each owner or operator must perform an initial 

relative accuracy test of the CERMS in accordance with the 

applicable Performance Specification in Appendix B to part 60 of 

the chapter. 

(iv) Each owner or operator must operate the CERMS and 

record data during all periods of operation of the affected 

facility including periods of startup, shutdown, and 

malfunction, 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. 

(3) Each owner or operator must calculate the lead 
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emissions rate in tons per year by summing all hours of CEMS 

data for a year to determine compliance with 63.1543 (b). 

(i) When the CERMS are unable to provide quality assured 

data the following applies: 

(A) When data are not available for periods of up to 48 

hours, the highest recorded hourly emission rate from the 

previous 24 hours must be used. 

(B) When data are not available for 48 or more hours, the 

maximum daily emission rate based on the previous 30 days must 

be used. 

(k) The owner or operator of each source subject to 

§63.1544(a) must operate a continuous monitoring system for the 

measurement of lead compound concentrations in air. 

(1) The owner or operator must operate compliance monitors 

sufficient in number, location, and frequency of sample 

collection to detect expected maximum concentrations of lead 

compounds in air due to emissions from the affected source(s) in 

accordance with a written plan as described in (k)(2) of this 

paragraph and approved by the Administrator. The plan must 

include descriptions of the sampling and analytical methods 

used. The plan may take into consideration existing monitoring 

being conducted under a state monitoring plan in accordance with 

Part 58. 
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(2) The owner or operator must submit a written plan 

describing and explaining the basis for the design and adequacy 

of the compliance monitoring network, the sampling, analytical, 

and quality assurance procedures, and any other related 

procedures, and the justification for any seasonal, background, 

or other data adjustments within 45 days after the effective 

date of this subpart. 

 (3) The Administrator at any time may require changes in, 

or expansion of, the monitoring program, including additional 

sampling and analytical protocols and network design. 

 (l) If all rolling three-month average concentration of lead 

in air measured by the compliance monitoring system are less 

than [50 percent] of the lead concentration in air limit in 

§63.1544(a) for three consecutive years, the owner or operator 

may submit a revised plan to reduce the monitoring sampling and 

analysis frequency (e.g., from daily to weekly). 

 For any subsequent period, if any rolling three-month 

average lead concentration in air measured at any monitor in the 

monitoring system exceeds [50 percent] of the concentration 

limit in §63.1544(a), the owner or operator must resume 

monitoring pursuant to paragraph (k)(1) at all monitors until 

another three consecutive years of lead concentration in air 

measurements less than [50 percent] of the lead concentration in 
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air limit is demonstrated. 

9. Section 63.1548 is revised to read as follows: 

§63.1548 Notification requirements. 

 (a) The owner or operator of a primary lead processor must 

comply with the notification requirements of Sec. 63.9 of 

subpart A, General Provisions as specified in Table 1 of this 

subpart. 

 (b) The owner or operator of a primary lead processor must 

submit the standard operating procedures manual for baghouses 

required under Sec. 63.1547(a) to the Administrator or delegated 

authority along with a notification that the primary lead 

processor is seeking review and approval of the manual and 

procedures. Owners or operators of existing primary lead 

processors must submit this notification no later than November 

6, 2000. The owner or operator of a primary lead processor that 

commences construction or reconstruction after April 17, 1998, 

must submit this notification no later than 180 days before 

startup of the constructed or reconstructed primary lead 

processor, but no sooner than September 2, 1999. 

 (c) The owner or operator of a primary lead processor must 

submit the compliance monitoring network plan required under 

Sec. 63.1547(k)(2) to the Administrator or delegated authority 

along with a notification that the primary lead processor is 
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seeking review and approval of the plan. Owners or operators of 

existing primary lead processors must submit this notification 

no later than 45 days after promulgation of this subpart. The 

owner or operator of a new, reconstructed, or modified primary 

lead processor must submit this notification no later than 180 

days before startup of the constructed or reconstructed primary 

lead processor. 

10. Section 63.1549 is revised to read as follows: 

§63.1549 Recordkeeping and reporting requirements. 

 (a) The owner or operator of a primary lead processor must 

comply with the recordkeeping requirements of Sec. 63.10 of 

subpart A, General Provisions as specified in Table 1 of this 

subpart. 

 (b) In addition to the general records required by 

paragraph (a) of this section, each owner or operator of a 

primary lead processor must maintain for a period of 5 years, 

records of the information listed in paragraphs (b)(1) through 

(b)(10) of this section. 

 (1) Production records of the weight and lead content of 

lead products, copper matte, and copper speiss. 

 (2) Records of the bag leak detection system output. 

 (3) An identification of the date and time of all bag leak 

detection system alarms, the time that procedures to determine 
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the cause of the alarm were initiated, the cause of the alarm, 

an explanation of the actions taken, and the date and time the 

cause of the alarm was corrected. 

 (4) Any recordkeeping required as part of the requirements 

described in the compliance monitoring system plan required 

under §63.1547(k)(2). 

 (5) Any recordkeeping required as part of the practices 

described in the standard operating procedures manual for 

baghouses required under Sec. 63.1547(a). 

 (6) If an owner or operator chooses to demonstrate 

continuous compliance with the sinter building in-draft 

requirement under Sec. 63.1543(d) by employing the method 

allowed in Sec. 63.1547(i)(1), the records of the daily doorway 

in-draft checks, an identification of the periods when there was 

not a positive in-draft, and an explanation of the corrective 

actions taken. 

 (7) If an owner or operator chooses to demonstrate 

continuous compliance with the sinter building in-draft 

requirement under Sec. 63.1543(d) by employing the method 

allowed in Sec. 63.1547(i)(2), the records of the output from 

the continuous volumetric flow monitor(s), an identification of 

the periods when the 15-minute volumetric flow rate dropped 

below the minimum established during the most recent in-draft 
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determination, and an explanation of the corrective actions 

taken. 

 (8) If an owner or operator chooses to demonstrate 

continuous compliance with the sinter building in-draft 

requirement under Sec. 63.1543(d) by employing the method 

allowed in Sec. 63.1547(i)(2), and volumetric flow rate is 

monitored at the baghouse inlet, records of the daily checks of 

damper positions, an identification of the days that the damper 

positions were not in the positions established during the most 

recent in-draft determination, and an explanation of the 

corrective actions taken. 

(9) Records of the occurrence and duration of each 

malfunction of operation (i.e., process equipment) or the air 

pollution control equipment and monitoring equipment. 

 (10)Records of actions taken during periods of malfunction 

to minimize emissions in accordance with §§63.1543(i) and 

63.1544(e), including corrective actions to restore 

malfunctioning process and air pollution control and monitoring 

equipment to its normal or usual manner of operation. 

 (c) Records for the most recent 2 years of operation must 

be maintained on site. Records for the previous 3 years may be 

maintained off site. 

 (d) The owner or operator of a primary lead processor must 
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comply with the reporting requirements of Sec. 63.10 of subpart 

A, General Provisions as specified in Table 1 of this subpart. 

 (e) In addition to the information required under Sec. 

63.10 of the General Provisions, the owner or operator must 

provide semi-annual reports containing the information specified 

in paragraphs (e)(1) through (e)(9) of this section to the 

Administrator or designated authority. 

 (1) The reports must include records of all alarms from the 

bag leak detection system specified in Sec. 63.1547(e). 

 (2) The reports must include a description of the actions 

taken following each bag leak detection system alarm pursuant to 

§63.1547(f). 

 (3) The reports must include a calculation of the 

percentage of time the alarm on the bag leak detection system 

sounded during the reporting period pursuant to Sec. 63.1547(g). 

 (4) If an owner or operator chooses to demonstrate 

continuous compliance with the sinter building in-draft 

requirement under §63.1543(d) by employing the method allowed in 

§63.1547(i)(1), the reports must contain an identification of 

the periods when there was not a positive in-draft, and an 

explanation of the corrective actions taken. 

 (5) If an owner or operator chooses to demonstrate 

continuous compliance with the sinter building in-draft 
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requirement under §63.1543(d) by employing the method allowed in 

§63.1547(i)(2), the reports must contain an identification of 

the periods when the 15-minute volumetric flow rate(s) dropped 

below the minimum established during the most recent in-draft 

determination, and an explanation of the corrective actions 

taken. 

 (6) If an owner or operator chooses to demonstrate 

continuous compliance with the sinter building in-draft 

requirement under §63.1543(d) by employing the method allowed in 

§63.1547(i)(2), and volumetric flow rate is monitored at the 

baghouse inlet, the reports must contain an identification of 

the days that the damper positions were not in the positions 

established during the most recent in-draft determination, and 

an explanation of the corrective actions taken. 

 (7) The reports must contain a summary of the records 

maintained as part of the practices described in the standard 

operating procedures manual for baghouses required under 

§63.1547(a), including an explanation of the periods when the 

procedures were not followed and the corrective actions taken. 

 (8) The reports must contain a summary of the compliance 

monitoring results for the required reporting period, including 

an explanation of any periods when the procedures outlined in 

the compliance monitoring system plan required by §63.1547(k)(2) 
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were not followed and the corrective actions taken. 

 (9) If there was a malfunction during the reporting period, 

the report shall also include the number, duration, and a brief 

description for each type of malfunction which occurred during 

the reporting period and which caused or may have caused any 

applicable emission limitation to be exceeded. The report must 

also include a description of actions taken by an owner or 

operator during a malfunction of an affected source to minimize 

emissions in accordance with §§63.1543(i) and 63.1544(b), 

including actions taken to correct a malfunction. 

11. Section 63.1550 is revised to read as follows: 

§63.1550 Delegation of authority. 

 (a) In delegating implementation and enforcement authority 

to a State under section 112(1) of the act, the authorities 

contained in paragraph (b) of this section must be retained by 

the Administrator and not transferred to a State. 

 (b) Authorities which will not be delegated to States: no 

restrictions. 

12. Section 63.1551 is added to read as follows: 

§63.1551 Affirmative defense for exceedance of emission limit 

during malfunction. 

In response to an action to enforce the standards set forth 

in this subpart you may assert an affirmative defense to a claim 
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for civil penalties for exceedances of such standards that are 

caused by malfunction, as defined in 40 CFR 63.2. Appropriate 

penalties may be assessed, however, if you fail to meet your 

burden of proving all 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, you 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 

(2) Repairs were made as expeditiously as possible when the 
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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) All of the actions in response to the excess emissions 

were documented by properly signed, contemporaneous operating 

logs; and 

(8) At all times, the facility was operated in a manner 

consistent with good practices for minimizing emissions; and 

(9) A written root cause analysis has been prepared to 

determine, correct and eliminate the primary causes of the 

malfunction and the excess emissions resulting from the 
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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 this 

subpart to demonstrate, with all necessary supporting 

documentation, that it has met the requirements set forth in 

paragraph (d)(1) of this section. 

12. Table 1 to Subpart TTT of Part 63 is revised to read as 

follows: 

Table 1 of Subpart TTT – General Provisions Applicability to 

Subpart TTT 

Reference 

Applies 

to 

subpart Comment 
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TTT

* * * * * * * 

63.6(a), (b), (c) Yes 

63.6 (d) No Section reserved.

63.6(e)(1)(i) No See 63.1543(i) 

and 63.1544(b) 

for general duty 

requirement. 

63.6(e)(1)(ii) No

63.6(e)(1)(iii) Yes 

63.6(e)(2) No Section reserved.

63.6(e)(3) No 

63.6(f)(1) No 

63.6(g) Yes 

63.6(h) No No opacity limits 

in rule.

63.6(i) Yes 

63.6(j) Yes 

§63.7(a)-(d) Yes 

§63.7(e)(1) No See 63.1546(c). 

§63.7(e)(2)-(e)(4) Yes 

63.7(f), (g), (h) Yes 

63.8(a)-(b) Yes 

63.8(c)(1)(i) No 

63.8(c)(1)(ii) Yes 

63.8(c)(1)(iii) No

63.8(c)(2)-(d)(2) Yes 

63.8(d)(3) Yes, 

except 
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for last 

sentence

63.8(e)-(g) Yes 

63.9(a),(b),(c),(e),(g),(h)(1)through 

(3), (h)(5) and (6), (i) and (j) 

Yes 

63.9(f) No 

63.9(h)(4) No Reserved 

63.10(b)(2)(i) No 

63.10(b)(2)(ii) No See 63.1549(b)(9) 

and (10) for 

recordkeeping of 

occurrence and 

duration of 

malfunctions and 

recordkeeping of 

actions taken 

during 

malfunction. 

63.10(b)(2)(iii) Yes 

63.10(b)(2)(iv)-(b)(2)(v) No 

63.10(b)(2)(vi)-(b)(2)(xiv) Yes 

63.(10)(b)(3) Yes 

63.10(c)(1)-(9) Yes 

63.10(c)(10)-(11) No See 63.1549(b)(9) 

and (10) for 

recordkeeping of 

malfunctions. 

63.10(c)(12)-(c)(14) Yes 

63.10(c)(15) No 

63.10(d)(1)-(4) Yes

63.10(d)(5) No See 63.1549(e)(9) 

for reporting of 

malfunctions. 

63.10(e)-((f) Yes 

* * * * * * * 
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