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6560-50-P

ENVIRONMENTAL PROTECTION

40 CFR Part 63

[EPA-HQ-OAR-2010-0544; FRL-???]

RIN 2060-AQ40

National Emissions Standards for Hazardous Air Pollutants: 

Secondary Aluminum Production

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

SUMMARY: The EPA is proposing amendments to the national 

emissions standards for hazardous air pollutants for Secondary 

Aluminum Production to address the results of the residual risk 

and technology review that the EPA is required to conduct by the 

Clean Air Act. In addition, the EPA is proposing amendments to 

correct and clarify rule requirements and provisions. These 

proposed amendments would require emission sources to comply 

with the emission limits at all times including periods of 

startup and shutdown; add a definition of affirmative defense;

add a requirement to report performance testing through the 

Electronic Reporting Tool (ERT); add rule provisions allowing 

owners and operators to change furnace classifications; add rule 

requirements regarding testing of uncontrolled furnaces; add 

compliance provisions for hydrogen fluoride (HF) for 
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uncontrolled group 1 furnaces; add operating requirements such 

as monitoring of lime injection rates; and make technical 

corrections and clarifications to the applicability, 

definitions, operating, monitoring, and performance testing 

requirements.

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

45 DAYS AFTER THE DATE OF PUBLICATION OF THIS PROPOSED RULE 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 THE DATE 30 DAYS AFTER THE DATE OF PUBLICATION OF THIS 

PROPOSED RULE IN THE FEDERAL REGISTER].

Public Hearing. If anyone contacts the EPA requesting to 

speak at a public hearing by [INSERT THE DATE 10 DAYS AFTER THE 

DATE OF PUBLICATION IN THE FEDERAL REGISTER], a public hearing 

will be held on [INSERT THE DATE 15 DAYS AFTER THE DATE OF 

PUBLICATION IN THE FEDERAL REGISTER].

ADDRESSES: Submit your comments, identified by Docket ID Number 

EPA-HQ-OAR-2010-0544, by one of the following methods:

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

for submitting comments.

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

EPA-HQ-OAR-2010-0544.

 Fax: (202) 566-9744, Attention Docket ID Number EPA-HQ-OAR2010-0544.
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 Mail: U.S. Postal Service, send comments to: EPA Docket 

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

EPA-HQ-OAR-2010-0544, 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-2010-0544. 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 EPAHQ-OAR-2010-0544. The 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 http://www.regulations.gov, including 

any personal information provided, unless the comment includes 

information claimed to be confidential business information 

(CBI) or other information whose disclosure is restricted by 

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

or otherwise protected through http://www.regulations.gov or 

email. The http://www.regulations.gov website is an “anonymous 

access” system, which means the EPA will not know your identity 

or contact information unless you provide it in the body of your 

comment. If you send an email comment directly to the EPA

without going through http://www.regulations.gov, your email 
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address will be automatically captured and included as part of 

the comment that is placed in the public docket and made 

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

the EPA recommends that you include your name and other contact 

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

technical difficulties and cannot contact you for clarification, 

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

files should avoid the use of special characters, any form of 

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

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

EPA Docket Center homepage at 

http://www.epa.gov/epahome/dockets.htm.

Docket. The EPA has established a docket for this 

rulemaking under Docket ID Number EPA-HQ-OAR-2010-0544. The 

proposed rulemaking also used material from Docket ID Number

EPA-HQ-OAR_2010-0469 in the development of this rule. All 

documents in the docket are listed in the 

http://www.regulations.gov index. Although listed in the index, 

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

information whose disclosure is restricted by statute. Certain 

other material, such as copyrighted material, is not placed on 

the Internet and will be publicly available only in hard copy. 

Publicly available docket materials are available either 
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electronically in http://www.regulations.gov or in hard copy at 

the EPA Docket Center, EPA West, Room 3334, 1301 Constitution 

Ave., NW, Washington, DC. The Public Reading Room is open from 

8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal 

holidays. The telephone number for the Public Reading Room is 

(202) 566-1744, and the telephone number for the EPA Docket 

Center is (202) 566-1742.

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

at 10:00 a.m. on [INSERT THE DATE 15 DAYS AFTER THE DATE OF 

PUBLICATION OF THIS PROPOSED RULE IN THE FEDERAL REGISTER] and 

will be held at the 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, (D243-02), U.S. 

Environmental Protection Agency, Research Triangle Park, North 

Carolina 27711; telephone number: (919) 541–0832.

FOR FURTHER INFORMATION CONTACT: For questions about this 

proposed action, contact Ms. Rochelle Boyd, 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) 541-1390; 

fax number: (919) 541-3207; and email address:
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boyd.rochelle@epa.gov. For specific information regarding the 

risk modeling methodology, contact Dr. Michael Stewart, Office 

of Air Quality Planning and Standards, Health and Environmental 

Impacts Division, Air Toxics Assessment Group (C504–06), U.S. 

Environmental Protection Agency, Research Triangle Park, NC 

27711; telephone number: (919) 541–7524; fax number: (919) 541–

0840; and email address: stewart.michael@epa.gov. For 

information about the applicability of the national emission 

standards for hazardous air pollutants (NESHAP) to a particular 

entity, contact the appropriate person listed in Table 1 of this 

preamble.

Table 1. List of EPA Contacts For The NESHAP Addressed In This 

Proposed Action

NESHAP for: OECA Contact1 OAQPS Contact2

Secondary 

Aluminum 

Production

Scott Throwe, 

(202)564-7013 

throwe.scott@epa.gov

Rochelle Boyd,

(919) 541-1390, 

boyd.rochelle@epa.gov 

1 EPA Office of Enforcement and Compliance Assurance.

2 EPA Office of Air Quality Planning and Standards.

SUPPLEMENTARY INFORMATION:

Preamble Acronyms and Abbreviations

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, for 

ease of reading of this preamble and for reference purposes, the 

following terms and acronyms are defined here:
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ACGIH American Conference of Government Industrial 

Hygienists

ADAF age-dependent adjustment factors

AEGL acute exposure guideline levels

AERMOD air dispersion model used by the HEM-3 model

APCD air pollution control devices

AMOS ample margin of safety

ANPRM advance notice of proposed rulemaking

ATSDR Agency for Toxic Substances and Disease Registry

BACT best available control technology

CAA Clean Air Act

CBI confidential business information

CFR Code of Federal Regulations

D/F dioxins and furans

EJ environmental justice

EPA Environmental Protection Agency

ERPG Emergency Response Planning Guidelines

ERT Electronic Reporting Tool

HAP hazardous air pollutants

HCl hydrogen chloride

HEM-3 Human Exposure Model, Version 3

HF hydrogen fluoride

HHRAP human health risk assessment protocols

HI hazard index

HQ hazard quotient

ICR information collection request

IRIS Integrated Risk Information System

km kilometer

LAER lowest achievable emissions rate

lb/yr pounds per year

MACT maximum achievable control technology

MACT Code code within the NEI used to identify processes

included in a source category

MDL method detection level

mg/acm milligrams per actual cubic meter

mg/dscm milligrams per dry standard cubic meter

mg/m3 milligrams per cubic meter

MIR maximum individual risk

MRL minimum risk level
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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

NEI National Emissions Inventory

NESHAP National Emissions Standards for Hazardous Air 

Pollutants

NOAEL no observed adverse effects level

NRC National Research Council

NTTAA National Technology Transfer and Advancement Act

O&M operation and maintenance

OAQPS Office of Air Quality Planning and Standards

OECA Office of Enforcement and Compliance Assurance

OHEA Office of Health and Environmental Assessment

OMB Office of Management and Budget

PB-HAP hazardous air pollutants known to be persistent and 

bio-accumulative in the environment

PM particulate matter

ppmv parts per million by volume

RACT reasonably available control technology

RBLC RACT/BACT/LAER Clearinghouse

REL reference exposure level

RFA Regulatory Flexibility Act

RfC reference concentration

RfD reference dose

RIA regulatory impact analysis

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

SIP state implementation plan

SOP standard operating procedures

SSM startup, shutdown, and malfunction

TEF toxic equivalency factors

TEQ toxic equivalency quotient

THC total hydrocarbons
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TOSHI target organ-specific hazard index

tpy tons per year

TRIM Total Risk Integrated Modeling System

TTN Technology Transfer Network

UBC used beverage containers

UF uncertainty factor

μg/m3 microgram per cubic meter

UMRA Unfunded Mandates Reform Act

UPL upper predictive limit

URE unit risk estimate

VOC volatile organic compounds

VOHAP volatile organic hazardous air pollutants

WHO World Health Organization

WWW worldwide web

Organization of this Document. The information in this preamble 

is organized as follows:

I. General Information

A. What is the statutory authority for this action?

B. Does this action apply to me?

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

information?

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

II. Background

A. What is this source category and how did the MACT standard 

regulate its HAP emissions?

B. What data collection activities were conducted to support 

this action?

III. Analyses Performed

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

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

this proposal?

C. How did we perform the technology review?

D. What other issues are we addressing in this proposal?

IV. Analytical Results and Proposed Decisions

A. What are the results of the risk assessments?

B. What are our proposed decisions regarding risk acceptability 

and ample margin of safety?

C. What are the results and proposed decisions based on our 

technology review?

D. What other actions are we proposing?
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E. Compliance dates

V. Summary of Cost, Environmental, and Economic Impacts

A. What are the affected sources?

B. What are the air quality impacts?

C. What are the cost impacts?

D. What are the economic impacts?

E. What are the benefits?

VI. Request for Comments

VII. Submitting Data Corrections

VIII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and 

Executive Order 13563: Improving Regulation and Regulatory 

Review.

B. Paperwork Reduction Act.

C. Regulatory Flexibility Act.

D. Unfunded Mandates Reform Act.

E. Executive Order 13132: Federalism.

F. Executive Order 13175: Consultation and Coordination with 

Indian Tribal Governments.

G. Executive Order 13045: Protection of Children from 

Environmental Health Risks and Safety Risks.

H. Executive Order 13211: Actions Concerning Regulations That 

Significantly Affect Energy Supply, Distribution, or Use.

I. National Technology Transfer and Advancement Act.

J. Executive Order 12898: Federal Actions to Address 

Environmental Justice in Minority Populations and Low-Income 

Populations.

I. General Information

A. What is the statutory authority for this action? 

Section 112 of the CAA establishes a two-stage regulatory 

process to address emissions of hazardous air pollutants (HAP)

from stationary sources. In the first stage, after the EPA has 

identified categories of sources emitting one or more of the HAP 

listed in section 112(b) of the CAA, section 112(d) of the CAA 

calls for us to promulgate national emission standards for 
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hazardous air pollutants (NESHAP) for those sources. “Major 

sources” are those that emit or have the potential to emit (PTE)

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 technologybased 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 emissions 

reduction achievable through the application of measures, 

processes, methods, systems or techniques including, but not 

limited to, measures which (1) reduce the volume of or eliminate 

emissions of pollutants through process changes, substitution of 

materials or other modifications, (2) enclose systems or 

processes to eliminate emissions, (3) capture or treat 

pollutants when released from a process, stack, storage or 

fugitive emissions point, (4) are design, equipment, work 

practice or operational standards (including requirements for 

operator training or certification) or (5) are a combination of 

the above. CAA section 112(d)(2)(A)-(E). The MACT standard may 

take the form of a design, equipment, work practice or 

operational standard where the EPA first determines that either 

(1) a pollutant cannot be emitted through a conveyance designed 
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and constructed to emit or capture the pollutant or that any 

requirement for, or use of, such a conveyance would be 

inconsistent with law, or (2) 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 emission limitation achieved by the best-performing 

12 percent of existing sources in the category or subcategory 

(or the best-performing five 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 

stringent than the floor based on consideration of the cost of 

achieving the emissions reductions and any non-air quality 

health and environmental impacts and energy requirements.

Under CAA section 112(d)(6), the EPA is then required to 

review these technology-based standards and to revise them “as 
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necessary (taking into account developments in practices, 

processes, and control technologies)” no less frequently than 

every 8 years. In conducting this review, the 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 the EPA prepare a Report to 

Congress discussing (among other things) methods of calculating 

risk posed (or potentially posed) by sources after 

implementation of the MACT standards, the public health 

significance of those risks, and the EPA’s recommendations as to 

legislation regarding such remaining risk. The 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 the EPA’s obligation under CAA 

section 112(f)(2) to analyze and address residual risk.

CAA section 112(f)(2) requires us to determine, for source 

categories subject to certain MACT standards, whether the 

emissions standards provide an ample margin of safety to protect 

public health. If the MACT standards for HAP “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 
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than one in one million,” the 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. In doing so, the EPA may adopt standards equal to 

existing MACT standards if the EPA determines that the existing 

standards are sufficiently protective. NRDC v. EPA, 529 F.3d 

1077, 1083 (D.C. Cir. 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.”) The EPA must also adopt 

more stringent standards, if necessary, to prevent an adverse 

environmental effect1 but must consider cost, energy, safety and 

other relevant factors in doing so.

Section 112(f)(2) of the CAA expressly preserves our use of 

a 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 

 

1

“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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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 necessary 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 EPA’s 

interpretation set out in the Benzene NESHAP, and the United 

States Court of Appeals for the District of Columbia Circuit in 

NRDC v. EPA concluded that the EPA’s interpretation of 

subsection 112(f)(2) is a reasonable one. See NRDC v. EPA, 529 

F.3d 1077 1083 (D.C. Cir. 2008) (“[S]ubsection 112(f)(2)(B) 

expressly incorporates the EPA’s interpretation of the Clean Air 

Act from the Benzene standard, complete with a citation to the 

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, 54 FR at 38044-38045, we stated as 

an overall objective:
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In protecting public health with an ample margin of safety

under section 112, EPA strives 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 

plant would have if he or she were exposed to the maximum 

pollutant concentrations for 70 years.

The agency stated that “[t]he 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 risk to the 

exposed population as a whole, by providing an estimate of the 

occurrence of cancer or other serious health effects in the 

exposed population.” 54 FR at 38045. The agency went on to 

conclude that “estimated incidence would be weighed along with 

other health risk information in judging acceptability.” 54 FR 

at 38046. As explained more fully in our Residual Risk Report to 

Congress, the 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–
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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 at 38045. We discussed the 

maximum individual lifetime cancer risk (or maximum individual 

risk (MIR)) 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 risk, but displays a conservative risk level 

which is an upper bound 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 
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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: “[i]n 

establishing a presumption for MIR, 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 km [kilometer] 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 

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 the EPA in the first step of the Vinyl Chloride
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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 * * *.” 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.” 54 FR at 38046.

As discussed above, we apply a two-step process for 

developing standards to address residual risk. In the first 

step, the EPA determines whether 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)2 of approximately 

1 in 10 thousand [i.e., 100 in 1 million].” 54 FR at 38045. In 

the second step of the process, the 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 

 

2

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 to be exposed to the maximum level 

of a pollutant for a lifetime.
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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 determinations, the EPA presented 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 

noncancer hazard index (HI); and the maximum acute noncancer 

hazard. In estimating risks, the EPA considered source 

categories under review that are located near each other and 

that affect the same population. The EPA estimates risk based on

the actual emissions from the source category under review as 

well as based on the emissions allowed pursuant to the source 

category MACT standard. The EPA also discussed and considered 

risk estimation uncertainties. The EPA is providing this same 

type of information in support of these actions.

The agency acknowledges that the Benzene NESHAP provides 

flexibility regarding what factors the EPA might consider in 

making our determinations and how they might be weighed for each 

source category. In responding to comment on our policy under 

the Benzene NESHAP, the EPA explained that: “[t]he policy chosen 

by the Administrator permits consideration of multiple measures 

of health risk. Not only can the MIR figure be considered, but 
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also incidence, the presence of noncancer 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 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. The Benzene 

NESHAP explains “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 
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presumptively acceptable level is unacceptable in the light of 

other health risk factors.” 54 FR at 38045. Similarly, with 

regard to the ample margin of safety analysis, the Benzene 

NESHAP states 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-related factors) vary from source 

category to source category.” 54 FR at 38061.

B. Does this action apply to me?

The regulated industrial source category that is the 

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

Table 2 of this preamble is not intended to be exhaustive, but 

rather provides a guide for readers regarding the entities 

likely to be affected by this proposed action. These standards,

once finalized, will be directly applicable to affected sources. 

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

affected by this proposed action. The EPA defined the Secondary 

Aluminum source category in 1992 as any establishment using 

clean charge, aluminum scrap, or dross from aluminum production, 

as the raw material and performing one or more of the following 

processes: scrap shredding, scrap drying/delacquering/decoating, 

thermal chip drying, furnace operations (i.e., melting, holding, 
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sweating, refining, fluxing, or alloying), recovery of aluminum 

from dross, in-line fluxing, or dross cooling. 

Table 2. NESHAP and Industrial Source Categories Affected By 

This Proposed Action

Source Category NESHAP NAICS 

code1

MACT 

code2

Secondary Aluminum Production

Primary aluminum production facilities

Aluminum sheet, plate, and foil 

manufacturing facilities

Aluminum extruded product manufacturing 

facilities

Other aluminum rolling and drawing 

facilities

Aluminum die casting facilities

Aluminum foundry facilities

Secondary 

Aluminum 

Production

331314

331312

331315

331316

331319

331521

331524

0044

1 North American Industry Classification System

2 Maximum Achievable Control Technology

C. 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 EPA’s Technology Transfer Network (TTN). 

Following signature by the EPA Administrator, a copy of this 

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

page for newly proposed or promulgated rules at the following 

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

provides information and technology exchange in various areas of 

air pollution control including the residual risk and technology 

review (RTR) and includes source category descriptions and 
Page 24 of 236

detailed emissions estimates and other data that were used as 

inputs to the risk assessments.

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

Submitting CBI. Do not submit information containing CBI to 

the EPA through http://www.regulations.gov or email. Clearly 

mark the part or all of the information that you claim to be 

CBI. For CBI information on a disk or CD ROM that you mail to 

the EPA, mark the outside of the disk or CD ROM as CBI and then 

identify electronically within the disk or CD ROM the specific 

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

version of the comment that includes information claimed as CBI, 

a copy of the comment that does not contain the information 

claimed as CBI must be submitted for inclusion in the public 

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

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

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

in the public docket and the EPA’s electronic public docket 

without prior notice. Information marked as CBI will not be 

disclosed except in accordance with procedures set forth in 40 

CFR part 2. Send or deliver information identified as CBI only 

to the following address: Roberto Morales, OAQPS Document 

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

Standards, U.S. Environmental Protection Agency, Research 
Page 25 of 236

Triangle Park, North Carolina 27711, Attention Docket ID Number 

EPA-HQ-OAR-2010-0544.

II. Background

A. What is this source category and how did the MACT standard 

regulate its HAP emissions?

The Secondary Aluminum Production source category includes 

facilities that produce aluminum from scrap aluminum material 

and consists of the following operations: (1) Preprocessing of 

scrap aluminum, including size reduction and removal of oils, 

coatings, and other contaminants; (2) Furnace operations 

including melting, in-furnace refining, fluxing, and tapping;

(3) Additional refining, by means of in-line fluxing; and (4) 

Cooling of dross. The following sections include descriptions of 

the affected sources in the secondary aluminum production source 

category, the origin of HAP emissions from these affected 

sources, and factors affecting the emissions. 

Scrap aluminum is often preprocessed prior to melting. 

Preprocessing steps may include shredding to reduce the size of 

aluminum scrap; drying of oily scrap such as machine turnings 

and borings; and/or heating in a scrap dryer, delacquering kiln 

or decoating kiln to remove coatings or other contaminants that 

may be present on the scrap. Heating of high iron content scrap 

in a sweat furnace to reclaim the aluminum content is also a 

preprocessing operation.
Page 26 of 236

Crushing, shredding and grinding operations are used to 

reduce the size of scrap aluminum. Particulate matter (PM) and

HAP metals emissions are generated as dust from coatings and 

other contaminants contained in the scrap aluminum as they are 

processed. 

A chip dryer is used to evaporate oil and/or moisture from 

uncoated aluminum chips and borings. Chip dryers typically 

operate at temperatures ranging between 150°C to 400°C (300°F to 

750°F). An uncontrolled chip dryer may emit dioxins and furans 

(D/F) and total hydrocarbons (THC), of which some fraction is 

organic HAP. 

Painted and/or coated materials are processed in a scrap 

dryer/delacquering kiln/decoating kiln to remove coatings and 

other contaminants that may be present in the scrap prior to 

melting. Coatings, oils, grease, and lubricants represent up to 

20 percent of the total weight of these materials. Organic HAP, 

D/F, and inorganic HAPs including particulate metal HAP are

emitted during the drying/delacquering/decoating process.

Used beverage containers (UBC) comprise a major portion of 

the recycled aluminum scrap used as feedstock by the industry. 

In scrap drying/delacquering/decoating operations, UBC and other 

post-consumer, coated products (e.g., aluminum siding) are

heated to an exit temperature of up to 540°C (1,000°F) to 

volatilize and remove various organic contaminants such as
Page 27 of 236

paints, oils, lacquers, rubber, and plastic laminates prior to 

melting. An uncontrolled scrap dryer/delacquering kiln/decoating 

kiln emits PM (of which some fraction is particulate metal HAP), 

HCl, THC (of which some fraction is organic HAP), and D/F.

A sweat furnace is typically used to reclaim (or ‘‘sweat’’) 

the aluminum from scrap with high levels of iron. These furnaces 

operate in batch mode at a temperature that is high enough to 

melt the aluminum but not high enough to melt the iron. The 

aluminum melts and flows out of the furnace while the iron

remains in the furnace in solid form. The molten aluminum can be 

cast into sows, ingots, or T-bars that are used as feedstock for 

aluminum melting and refining furnaces. Alternately, molten

aluminum can be fed directly to a melting or refining furnace.

An uncontrolled sweat furnace may emit D/F.

Process (i.e. melting, holding or refining) furnaces are 

refractory-lined metal vessels heated by an oil or gas burner to 

achieve a metal temperature of about 760°C (1,400°F). The 

melting process begins with the charging of scrap into the 

furnace. A gaseous (typically, chlorine) or salt flux may be

added to remove impurities and reduce aluminum oxidation. Once 

molten, the chemistry of the bath is adjusted by adding selected 

scrap or alloying agents, such as silicon. Salt and other fluxes

contain chloride and fluoride compounds that may be released 

when introduced to the bath. HCl may also be released when 
Page 28 of 236

chlorine-containing contaminants (such as polyvinyl chloride 

coatings) present in some types of scrap are introduced to the 

bath. Argon and nitrogen fluxes are not reactive and do not 

produce HAPs. In a sidewell melting furnace, fluxing is

performed in the sidewell and fluxing emissions from the 

sidewell are controlled. In this type of furnace, fluxing is not 

typically done in the hearth and hearth emissions (which include 

products of combustion from the oil and gas fired furnaces) are

typically uncontrolled.

Process furnaces may process contaminated scrap which can 

result in HAP emissions. In addition, fluxing agents may contain 

HAPs, some fraction of which is emitted from the furnace.

Process furnaces are significant sources of HAP emissions in the 

secondary aluminum industry. An uncontrolled melting furnace 

which processes contaminated scrap and uses reactive fluxes 

emits PM (of which some fraction is particulate metal HAP), HCl, 

and D/F.

Process furnaces are divided into group 1 and group 2 

furnaces. Group 1 furnaces are unrestricted in the type of scrap

they process and the type of fluxes they can use. Group 2 

furnaces process only clean charge and conduct no reactive 

fluxing.

Dross-only furnaces are furnaces dedicated to reclamation 

of aluminum from drosses formed during the melting/
Page 29 of 236

holding/alloying operations carried out in other furnaces. 

Exposure to the atmosphere causes the molten aluminum to 

oxidize, and the flotation of the impurities to the surface 

along with any salt flux creates ‘‘dross.’’ Prior to tapping, 

the dross is periodically skimmed from the surface of the

aluminum bath and cooled. Dross-only furnaces are typically 

rotary barrel furnaces (also known as salt furnaces). A drossonly furnace without controls emits PM (of which some fraction 

is particulate metal HAP).

Rotary dross coolers are devices used to cool dross in a 

rotating, water-cooled drum. A rotary dross cooler without 

controls emits PM (of which some fraction is particulate metal 

HAP).

In-line fluxers are devices used for aluminum refining, 

including degassing, outside the furnace. The process involves 

the injection of chlorine, argon, nitrogen or other gases to 

achieve the desired metal purity. Argon and nitrogen are not 

reactive and do not produce HAPs. In-line fluxers are found

primarily at facilities that manufacture very high quality 

aluminum or in facilities with no other means of degassing. An 

in-line fluxer operating without emission controls emits HCl and 

PM.

The Secondary Aluminum Production NESHAP was promulgated on 

March 23, 2000, (65 FR 15690) and codified as 40 CFR part 63, 
Page 30 of 236

subpart RRR. The rule was amended at 67 FR 79808, December 30, 

2002; 69 FR 53980, September 3, 2004; 70 FR 57513, October 3, 

2005 and 70 FR 75320, December 19, 2005. The existing subpart 

RRR NESHAP regulates HAP emissions from secondary aluminum 

production facilities that are major sources of HAP that operate 

aluminum scrap shredders, thermal chip dryers, scrap 

dryers/delacquering kilns/decoating kilns, group 1 furnaces,

group 2 furnaces, sweat furnaces, dross only furnaces, rotary 

dross coolers, and secondary aluminum processing units (SAPUs). 

The SAPUs include group 1 furnaces and in-line fluxers. The 

subpart RRR NESHAP regulates HAP emissions from secondary 

aluminum production facilities that are area sources of HAP only 

with respect to emissions of dioxins/furans (D/F) from thermal 

chip dryers, scrap dryers/delacquering kilns/decoating kilns, 

group 1 furnaces, sweat furnaces, and SAPUs.

The secondary aluminum industry consists of approximately 

161 secondary aluminum production facilities, of which the EPA 

estimates 53 to be major sources of HAP. Several of the 

secondary aluminum facilities are co-located with primary 

aluminum, coil coating, and possibly other source category 

facilities. Natural gas boilers or process heaters may also be 

co-located at a few secondary aluminum facilities.

The HAP emitted by these facilities are metals, organic 

HAP, D/F, hydrogen chloride (HCl), and hydrogen fluoride (HF).
Page 31 of 236

The standards promulgated in 2000 established emission 

limits for particulate matter (PM) as a surrogate for metal HAP, 

total hydrocarbons (THC) as a surrogate for organic HAP other 

than D/F, D/F expressed as toxicity equivalents, and HCl as a 

surrogate for acid gases including HF, chlorine and fluorine. 

HAP are emitted from the following affected sources: aluminum 

scrap shredders (subject to PM standards), thermal chip dryers 

(subject to standards for THC and D/F), scrap 

dryers/delacquering kilns/decoating kilns (subject to standards 

for PM, D/F, HCl and THC), sweat furnaces (subject to D/F

standards), dross-only furnaces (subject to PM standards), 

rotary dross coolers (subject to PM standards), group 1 furnaces 

(subject to standards for PM, HCl and D/F), and in-line fluxers 

(subject to standards for PM and HCl). Group 2 furnaces and 

certain in-line fluxers are subject to work practice standards. 

Table 3 provides a summary of the current MACT emissions limits 

for existing and new sources under the 2000 NESAHP and the 2005 

amendments.

Table 3. Emission Standards for New and Existing Affected 

Sources for the Secondary Aluminum Source Category

Affected source/ Emission unit Pollutant Limit Units

All new and existing affected 

sources and emission units 

that are controlled with a PM 

add-on control device and that 

choose to monitor with a 

Continuous Opacity Monitor 

(COM) and all new and existing 

Opacity 10 Percent
Page 32 of 236

aluminum scrap shredders that 

choose to monitor with a COM 

or to monitor visible 

emissions

New and existing aluminum 

scrap shredder

PM 0.01 gr/dscf

New and existing thermal chip 

dryer

THC

D/Fa

0.80

2.50

lb/ton of feed

μg TEQ/Mg of 

feed

New and existing scrap 

dryer/delacquering 

kiln/decoating kiln

 Or

PM

HCl

THC

D/Fa

0.08

0.80

0.06

0.25

lb/ton of feed

lb/ton of feed

lb/ton of feed

μg TEQ/Mg of 

feed

Alternative limits if 

afterburner has a design 

residence time of at least 1 

second and operates at a 

temperature of at least 

1400 °F

PM

HCl

THC

D/Fa

0.30

1.50

0.20

5.0

lb/ton of feed

lb/ton of feed

lb/ton of feed

μg TEQ/Mg of 

feed

New and existing sweat furnace D/Fa 0.80 ng TEQ/dscm @ 

11% O2

b

New and existing dross-only 

furnace

PM 0.30 lb/ton of feed

New and existing in-line 

fluxerc

HCl

PM

0.04

0.01

lb/ton of feed

lb/ton of feed

New and existing in-line 

fluxer with no reactive 

fluxing

No 

limit

Work practice: 

no reactive 

fluxing

New and existing rotary dross 

cooler

PM 0.04 gr/dscf

New and existing clean furnace 

(Group 2)

No 

limit

Work practices: 

clean charge 

only and no 

reactive fluxing

New and existing group 1 

melting/holding furnace 

(processing only clean 

charge)c

PM

HCl

0.80

0.40

or

10

lb/ton of feed

lb/ton of feed

percent of the 

HCl upstream of 

an add-on 

control device

New and existing group 1 

furnacec

PM

HCl

0.40

0.40

or

lb/ton of feed

lb/ton of feed
Page 33 of 236

10 percent of the 

HCl upstream of 

an add-on 

control device

D/Fa 15.0 μg TEQ/Mg of 

feed

New and existing group 1 

furnacec with clean charge 

only

PM

HCl

0.40

0.40

or

lb/ton of feed

lb/ton of feed

10 percent of the 

HCl upstream of 

an add-on 

control device

D/Fa No 

Limit

Clean charge 

only

New and existing secondary 

aluminum processing unita,d

(consists of all existing 

group 1 furnaces and existing 

in-line flux boxes at the 

facility, or all 

simultaneously constructed new 

group 1 furnaces and new inline fluxers)

PMe

 

  









 n

i

i

n

i

i i

t

T

L T

L

PM

PM

1

1

HClf

 

  









 n

i

i

n

i

i i

t

T

L T

L

HC l

HCl

1

1

D/Fg

 

  









 n

i

i

n

i

i i

t

T

L T

L

D F

D F

1

1

/

/

a D/F limit applies to a unit at a major or area source.

b Sweat furnaces equipped with afterburners meeting the specifications of 

§63.1505(f)(1) are not required to conduct a performance test.

c These limits are also used to calculate the limits applicable to secondary 

aluminum processing units.

d Equation definitions: LiPM = the PM emission limit for individual emission 

unit i in the secondary aluminum processing unit [kg/Mg (lb/ton) of feed]; 

Ti = the feed rate for individual emission unit i in the secondary aluminum 

processing unit; LtPM = the overall PM emission limit for the secondary 

aluminum processing unit [kg/Mg (lb-ton) of feed]; LiHCl = the HCl emission 

limit for individual emission unit i in the secondary aluminum processing 

unit [kg/Mg (lb/ton) of feed]; LtHCl = the overall HCl emission limit for the 

secondary aluminum processing unit [kg/Mg (lb/ton) of feed]; LiD/F = the D/F 

emission limit for individual emission unit i [μg TEQ/Mg (gr TEQ/ton) of 
Page 34 of 236

feed]; LtD/F = the overall D/F emission limit for the secondary aluminum 

processing unit [μg TEQ/Mg (gr TEQ/ton) of feed]; n = the number of units 

in the secondary aluminum processing unit.

e In-line fluxers using no reactive flux materials cannot be included in this

calculation since they are not subject to the PM limit.

f In-line fluxers using no reactive flux materials cannot be included in this 

calculation since they are not subject to the HCl limit.

g Clean charge furnaces cannot be included in this calculation since they are 

not subject to the D/F limit.

Control devices currently in use to reduce emissions from 

affected sources subject to the subpart RRR NESHAP include 

fabric filters for control of PM from aluminum scrap shredders; 

afterburners for control of THC and D/F from thermal chip 

dryers; afterburners plus lime-injected fabric filters for 

control of PM, HCl, THC, and D/F from scrap dryers/delacquering 

kilns/decoating kilns; afterburners for control of D/F from 

sweat furnaces; fabric filters for control of PM from dross-only 

furnaces and rotary dross coolers; lime-injected fabric filters 

for control of PM and HCl from in-line fluxers; and limeinjected fabric filters for control of PM, HCl and D/F from 

group 1 furnaces. All affected sources with add-on controls are 

also subject to design requirements and operating limits to 

limit fugitive emissions. 

Compliance with the emission limits in the current rule is 

demonstrated by an initial performance test for each affected 

source. Repeat performance tests are required every 5 years. 

Area sources are only subject to one-time performance tests for 

D/F. After the compliance tests, facilities are required to 
Page 35 of 236

monitor various control parameters or conduct other types of 

monitoring to ensure continuous compliance with the MACT 

standards. Owners or operators of sweat furnaces that operate an 

afterburner that meets temperature and residence time 

requirements are not required to conduct performance tests. 

B. What data collection activities were conducted to support

this action?

For the Secondary Aluminum Production source category, we 

compiled a dataset from two primary sources: (1) an all-company 

information collection request (ICR) sent to companies in 

February 2011, and (2) a nine-company testing ICR, sent in May 

2010.

Responses to the all-company ICR contained data on stack 

release characteristics such as height, volumetric flow rate, 

temperature, and location (latitude/longitude) coordinates. 

Responses to the all-company ICR also contained data on maximum 

production capacity and actual production in tpy and testing 

results for pollutants regulated under subpart RRR. 

As mentioned above, the pollutants regulated under subpart 

RRR are PM, HCl, THC and D/F. PM is a surrogate for metal HAP 

and THC is a surrogate for organic HAP. Since subpart RRR 

compliance testing is performed for the surrogates PM and THC, 

there are limited test data available for speciated metal HAP

and organic HAP emissions. Therefore, responses to the nine-
Page 36 of 236

company testing ICR were used to extrapolate the PM and THC 

testing results reported in the all-company ICR to specific 

metal and organic HAP emissions. In the nine-company testing 

ICR, companies were asked to provide speciated metal HAP 

concentrations (e.g. arsenic, cadmium, cobalt, lead, nickel, 

etc.) in the particulate collected by fabric filters. For more 

information on the selection of these facilities, see the Draft 

Technical Support Document for the Secondary Aluminum Production 

Source Category located in the docket. These data were then used 

to estimate speciated metal HAP emissions, based on the PM 

emissions reported in the all-company ICR. For example, if a 

response to the all-company ICR indicated a particular piece of 

equipment at a specific secondary aluminum facility had 10 tpy 

of PM emissions, and based on an analysis of the results of the 

nine-company testing ICR the EPA determined that the cobalt 

concentration in the fabric filter particulate matter catch was 

20 parts-per-million (ppm), the estimated emissions of cobalt 

would be 0.0002 tpy. In the nine-company testing ICR, companies 

were also required to conduct speciated organic HAP and THC 

emission testing for the two types of equipment that have THC 

limits under subpart RRR, scrap dryer/delacquering/decoating 

kilns and thermal chip dryers. The speciated organic HAPs for 

which data were provided included volatile HAPs (e.g., benzene, 
Page 37 of 236

chloroprene, toluene, etc.) and semi-volatile HAPs (anthracene, 

chrysene, naphthalene, etc.). 

Using the reported amount of charge or production for the 

most recent year and the reported test results (in lb per ton of 

charge) from the all-company ICR, emissions were calculated. 

Where test results from the all-company ICR responses were 

expressed in terms of PM and THC surrogates, emissions were 

converted to speciated metal and organic HAP emissions using the 

nine-company test results, as described above. Allowable and 

actual emissions were calculated for each piece of equipment. 

The derivation of allowable emissions estimates is described in 

Section III of this preamble.

The emissions data, calculations and risk assessment inputs 

for the Secondary Aluminum Production source category are 

described further in the memorandum Draft Development of the RTR 

Risk Modeling Dataset for the Secondary Aluminum Production 

Source Category which is available in the docket for this 

proposed rulemaking.

III. Analyses Performed

In this section we describe the analyses performed to 

support the proposed decisions for the RTR for this source 

category.

A. How did we estimate risks posed by the source category?
Page 38 of 236

The EPA conducted risk assessments that provide estimates 

of the MIR posed by the HAP emissions for each source in the 

category, the HI for chronic exposures to HAP with the potential 

to cause noncancer health effects, and the hazard quotient (HQ)

for acute exposures to HAP with the potential to cause noncancer 

health effects. The assessments also provided estimates of the 

distribution of cancer risks within the exposed populations, 

cancer incidence and an evaluation of the potential for adverse 

environmental effects for the source category. 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 

Secondary Aluminum Production Source Category. The methods used 

to assess risks (as described in the six primary steps below) 

are consistent with those peer-reviewed by a panel of the EPA’s 

Science Advisory Board (SAB) in 2009 and described in their peer 

review report issued in 20103; they are also consistent with the 

key recommendations contained in that report.

1. Establishing the nature and magnitude of actual emissions and 

identifying the emissions release characteristics

 

3

U.S. EPA SAB. Risk and Technology Review (RTR) Risk Assessment 

Methodologies: For Review by the EPA’s Science Advisory Board with 

Case Studies – MACT I Petroleum Refining Sources and Portland Cement 

Manufacturing, May 2010.
Page 39 of 236

As discussed in Section II.B. of this preamble, we used a 

dataset based on the estimated actual and allowable emissions as 

the basis for the risk assessment. This dataset was based on 

responses to an Information Collection Request (ICR) sent to 

approximately 425 facilities potentially subject to the subpart 

RRR NESHAP. Approximately 161 sources subject to the NESHAP 

responded, approximately 166 facilities confirmed that they were 

not subject to the NESHAP and no responses were received to 

approximately 51 ICRs. In addition to these responses, as 

described in section II.B, an earlier ICR was sent to 9 

companies requiring them to provide speciated metal and organic 

HAP concentrations for purposes of calculating speciated HAP 

emissions based on reported emissions of the surrogate 

pollutants, THC and PM. As part of our quality assurance (QA)

process, we checked the coordinates of every facility in the 

dataset using tools such as Google Earth. We corrected 

coordinates that were found to be incorrect. We also performed 

QA of the emissions data and release characteristics to identify

outliers and then confirmed or corrected the data.

2. Establishing the relationship between actual emissions and 

MACT-allowable emissions levels

The available emissions data in the MACT dataset include

estimates of the mass of HAP actually emitted during the 

specified annual time period. These “actual” emission levels are 
Page 40 of 236

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 “MACT-allowable” emissions level. This 

represents the highest 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 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.)

As discussed above, allowable and actual emissions were 

calculated for each piece of equipment. The estimates of actual 

emissions are described in Section II of this preamble. 

Allowable emissions for this source category were 

calculated by assuming emissions were at the maximum level 
Page 41 of 236

allowed by the MACT standard (i.e., we assume emissions would be 

emitted at a level equal to the MACT emission limit). 

Nevertheless, we note that these are conservative estimates of 

allowable emissions. It is unlikely that emissions would be at 

the maximum limit at all times because sources cannot emit HAP 

at a level that is exactly equal to the limit at all times and 

remain in compliance with the standard due to day-to-day 

variability in process operations and emissions. On average, 

facilities must emit at some level below the MACT limit to 

ensure that they are always in compliance.

The derivation of actual and allowable emissions estimates

are discussed in more detail in the document Draft Development 

of the RTR Emissions Dataset for the Secondary Aluminum 

Production Source Category which is available in the docket for 

this proposed rulemaking.

3. Conducting dispersion modeling, determining inhalation 

exposures and estimating individual and population inhalation 

risks

Both long-term and short-term inhalation exposure 

concentrations and health risks from each facility in the source 

category were estimated using the Human Exposure Model (HEM)

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

three primary risk assessment activities: (1) conducting 

dispersion modeling to estimate the concentrations of HAP in 
Page 42 of 236

ambient air, (2) estimating long-term 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 the EPA’s preferred models for assessing pollutant 

concentrations from industrial facilities.

4

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 (1991) of hourly 

surface and upper air observations for more than 158 

meteorological stations, selected to provide coverage of the 

United States and Puerto Rico. A second library of United States 

Census Bureau census block

5

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 

 

4

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).

5

A census block is generally the smallest geographic area for which 

census statistics are tabulated. 
Page 43 of 236

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 the 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 people 

who reside in that census block. We calculated the MIR for each 

facility as the cancer risk associated with a continuous 

lifetime (24 hours per day, 7 days per week, and 52 weeks per 

year for a 70-year period) 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. For residual risk assessments, we generally use URE values 
Page 44 of 236

from the EPA’s Integrated Risk Information System (IRIS). For 

carcinogenic pollutants without the EPA IRIS values, we look to 

other reputable sources of cancer dose-response values, often 

using California EPA (CalEPA) URE values, where available. In 

cases where new, scientifically credible dose-response values 

have been developed in a manner consistent with the EPA 

guidelines and have undergone a peer review process similar to 

that used by the EPA, we may use such dose-response values in 

place of, or in addition to, other values, if appropriate.

Incremental individual lifetime cancer risks associated 

with emissions from 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 

potential

6

) emitted by the modeled source. Cancer incidence and 

the distribution of individual cancer risks for the population 

within 50 km of any source were also estimated for the source 

category as part of these assessments by summing individual 

 

6

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.
Page 45 of 236

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 noncancer 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 for 

chronic exposures is the estimated chronic exposure divided by 

the chronic reference level, which is either the EPA reference 

concentration (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 from the EPA’s IRIS database is not available, a value from 

the following prioritized sources: (1) the agency for Toxic 

Substances and Disease Registry Minimum Risk Level, which is 

defined as “an estimate of daily human exposure to a substance 

that is likely to be without an appreciable risk of adverse 

effects (other than cancer) over a specified duration of 

exposure”; (2) the CalEPA Chronic Reference Exposure Level 

(REL), which is defined as “the concentration level at or below 

which no adverse health effects are anticipated for a specified 

exposure duration;” or (3) as noted above, a scientifically 
Page 46 of 236

credible dose-response value that has been developed in a manner 

consistent with the EPA guidelines and has undergone a peer 

review process similar to that used by the EPA, in place of or 

in concert with other values.

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 is located at this spot at a 

time when both the peak (hourly) emission rates from each 

emission point at the facility and worst-case dispersion 

conditions occur. The acute HQ is the estimated acute exposure 

divided by the acute dose-response value. In each case, acute HQ 

values were calculated using best available, short-term doseresponse values. These acute dose-response values, which are 

described below, include the acute REL, acute exposure guideline 

levels (AEGL) and emergency response planning guidelines (ERPG)

for 1-hour exposure durations. As discussed 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 
Page 47 of 236

effects are anticipated for a specified exposure duration.” 

Acute REL values are based on the most sensitive, relevant, 

adverse health effect reported in the medical and toxicological 

literature. Acute REL values are designed to protect the most 

sensitive sub-populations (e.g., asthmatics) by the inclusion of 

margins of safety. Since margins of safety are incorporated to 

address data gaps and uncertainties, exceeding the acute REL 

does not automatically indicate an adverse health impact.

AEGL values were derived in response to recommendations 

from the National Research Council (NRC). As described in 

Standing Operating Procedures (SOP) of the National Advisory 

Committee on Acute Exposure Guideline Levels for Hazardous 

Substances (http://www.epa.gov/opptintr/aegl/pubs/sop.pdf),

7

“the 

NRC’s previous name for acute exposure levels—community 

emergency exposure levels—was replaced by the term AEGL to 

reflect the broad application of these values to planning, 

response, and prevention in the community, the workplace, 

transportation, the military, and the remediation of Superfund 

sites.” This document also states that AEGL values “represent 

threshold exposure limits for the general public and are 

applicable to emergency exposures ranging from 10 minutes to 

eight hours.” The document lays out the purpose and objectives 

 

7

NAS, 2001. Standing Operating Procedures for Developing Acute 

Exposure Levels for Hazardous Chemicals, page 2.
Page 48 of 236

of AEGL by stating (page 21) that “the primary purpose of the 

AEGL program and the National Advisory Committee for Acute 

Exposure Guideline Levels for Hazardous Substances is to develop 

guideline levels for once-in-a-lifetime, short-term exposures to 

airborne concentrations of acutely toxic, high-priority 

chemicals.” In detailing the intended application of AEGL 

values, the document states (page 31) that “[i]t is anticipated 

that the AEGL values will be used for regulatory and 

nonregulatory purposes by U.S. Federal and state agencies and 

possibly the international community in conjunction with 

chemical emergency response, planning, and prevention programs. 

More specifically, the AEGL values will be used for conducting 

various risk assessments to aid in the development of emergency 

preparedness and prevention plans, as well as real-time 

emergency response actions, for accidental chemical releases at 

fixed facilities and from transport carriers.”

The AEGL–1 value is then specifically defined as “the 

airborne concentration of a substance above which it is 

predicted that the general population, including susceptible 

individuals, could experience notable discomfort, irritation, or 

certain asymptomatic nonsensory effects. However, the effects 

are not disabling and are transient and reversible upon 

cessation of exposure.” The document also notes (page 3) that, 

“Airborne concentrations below AEGL–1 represent exposure levels 
Page 49 of 236

that can produce mild and progressively increasing but transient 

and nondisabling odor, taste, and sensory irritation or certain 

asymptomatic, nonsensory effects.” Similarly, the document 

defines AEGL–2 values as “the airborne concentration (expressed 

as ppm or mg/m3) of a substance above which it is predicted that 

the general population, including susceptible individuals, could 

experience irreversible or other serious, long-lasting adverse 

health effects or an impaired ability to escape.”

ERPG values are derived for use in emergency response, as 

described in the American Industrial Hygiene Association’s 

document entitled, Emergency Response Planning Guidelines (ERPG) 

Procedures and Responsibilities

(http://www.aiha.org/1documents/committees/ERPSOPs2006.pdf)

which states that, “Emergency Response Planning Guidelines were 

developed for emergency planning and are intended as health 

based guideline concentrations for single exposures to 

chemicals.”

8

The ERPG–1 value is defined as “the maximum airborne 

concentration below which it is believed that nearly all 

individuals could be exposed for up to 1 hour without 

experiencing other than mild transient adverse health effects or 

without perceiving a clearly defined, objectionable odor.” 

Similarly, the ERPG–2 value is defined as “the maximum airborne 

 

8

ERP Committee Procedures and Responsibilities. November 1, 2006. 

American Industrial Hygiene Association.
Page 50 of 236

concentration below which it is believed that nearly all 

individuals could be exposed for up to 1 hour without 

experiencing or developing irreversible or other serious health 

effects or symptoms which could impair an individual’s ability 

to take protective action.”

As can be seen from the definitions above, the AEGL and 

ERPG values include the similarly defined severity levels 1 and 

2. For many chemicals, a severity level 1 value AEGL or ERPG has

not been developed; in these instances, higher severity level 

AEGL–2 or ERPG–2 values are compared to our modeled exposure 

levels to assess potential for acute concerns.

Acute REL values for 1-hour exposure durations are 

typically lower than their corresponding AEGL–1 and ERPG–1 

values. Even though their definitions are slightly different, 

AEGL–1 values are often similar to the corresponding ERPG–1 

values, and AEGL–2 values are often similar to ERPG–2 values. 

Maximum HQ values from our acute screening risk assessments 

typically result when basing them on the acute REL value for a 

particular pollutant. In cases where our maximum acute HQ value 

exceeds 1, we also report the HQ value based on the next highest 

acute dose-response value (usually the AEGL–1 and/or the ERPG–1 

value).

To develop screening estimates of acute exposures, we 

developed estimates of maximum hourly emission rates by 
Page 51 of 236

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 emissions 

events, in a heavily-industrialized 4-county area (Harris, 

Galveston, Chambers, and Brazoria Counties, Texas) were less 

than twice the annual average hourly emissions rate. The highest 

peak emissions event was 74 times the annual average hourly 

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

emissions rate to the annual average hourly emissions rate was 

9.9 This analysis is provided in Appendix 4 of the Draft Residual 

Risk Assessment for Secondary Aluminum Production 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 generally apply 

the assumption to most source categories that the maximum onehour emissions rate from any source other than those resulting 

in fugitive dust emissions are 10 times the average annual 

hourly emissions rate for that source. We use a factor other 

than 10 in some cases if we have information that indicates that 

 

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

or docket to access the source of these data.
Page 52 of 236

a different factor is appropriate for a particular source 

category. For this source category however, there was no such 

information available and the default factor of 10 was used in 

the acute screening process.

When worst-case HQ values from the initial acute screen 

step were less than 1, acute impacts were deemed negligible and 

no further analysis was performed. In the cases where any worstcase 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.

However, for this source category no acute values were greater 

than 1 and therefore, further refinement was not performed.

Ideally, we would prefer to have continuous measurements 

over 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 approach.

To better characterize the potential health risks 

associated with estimated acute exposures to HAP, and in 
Page 53 of 236

response to a key recommendation from the SAB’s peer review of 

the EPA’s RTR risk assessment methodologies,

10 we generally 

examine a wider range of available acute health metrics than we 

do for our chronic risk assessments. This is in response to the 

SAB’s acknowledgement that there are generally more data gaps 

and inconsistencies in acute reference values than there are in 

chronic reference values. 

Comparisons of the estimated maximum off-site 1-hour 

exposure levels are not typically made to occupational levels 

for the purpose of characterizing public health risks in RTR 

assessments. This is because they are developed for working age 

adults and are not generally considered protective for the 

general public. We note that occupational ceiling values are, 

for most chemicals, set at levels higher than a 1-hour AEGL-1.

4. Conducting multipathway exposure and risk screening

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 two-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). 

 

10 The SAB peer review of RTR Risk Assessment Methodologies is available 

at: 

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

68381/$File/EPA-SAB-10-007-unsigned.pdf.
Page 54 of 236

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. Since three of

these PB–HAP (cadmium compounds, POM and chlorinated D/F)

are emitted by at least one facility in this source

category, we proceeded to the second step of the

evaluation. In this step, we determined whether the 

facility-specific emission rates of each of the emitted PB–

HAP were large enough to create the potential for

significant non-inhalation human or environmental risks 

under, worst-case conditions. To facilitate this step, we 

developed emission rate thresholds for each PB–HAP using a

hypothetical worst-case screening exposure scenario 

developed for use in conjunction with the EPA’s TRIM.FaTE 

model. The hypothetical screening scenario was subjected

to a sensitivity analysis to ensure that its key design

parameters were established such that environmental

media concentrations were not underestimated (i.e., to 

minimize the occurrence of false negatives or results that 
Page 55 of 236

suggest that risks might be acceptable when, in fact, 

actual risks are high) and to also minimize the occurrence

of false positives for human health endpoints. We call

this application of the TRIM.FaTE model TRIM-Screen. The 

facility-specific emission rates of each of the PB–HAP were

compared to the TRIM-Screen emission threshold values for

each of the PB–HAP identified in the source category

datasets to assess the potential for significant human

health risks or environmental risks via non-inhalation 

pathways. See Section IV for results of this screening 

analysis. 

5. Conducting other risk-related analyses: facilitywide 

assessments

To put the source category risks in context, for our 

residual risk reviews, we also typically examine the risks from 

the entire “facility,” where the facility includes all HAPemitting operations within a contiguous area and under common 

control. In these facilitywide assessments we examine the HAP 

emissions not only from the source category of interest, but 

also emissions of HAP from all other emissions sources at the 

facility. For the secondary aluminum source category, a 

facilitywide assessment was performed for all major sources. 

A facilitywide assessment was not conducted for area 

sources. By definition, no major sources of HAP (e.g., primary 
Page 56 of 236

aluminum production or coil coating operations) are collocated 

with any of the secondary aluminum area sources. Further, at 

many area sources, equipment subject to the Secondary Aluminum 

NESHAP is the only HAP-emitting equipment. Therefore, the most 

significant HAP emissions from area sources were already being 

considered under the area source risk assessment, and low levels 

of HAP emissions from equipment not subject to the Secondary 

Aluminum NESHAP at these facilities would not contribute 

appreciably to the risk profile. The results of the facilitywide 

assessment for major sources are provided in Section IV.

6. Considering uncertainties in risk assessment

Uncertainty and the potential for bias are inherent in all 

risk assessments, including those performed for the Secondary 

Aluminum source category addressed in this proposal. Although 

uncertainty exists, we believe that our approach, which used 

conservative tools and assumptions, ensures that our decisions 

are health-protective. A brief discussion of the uncertainties 

in the emissions datasets, 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 (referenced 

earlier) available in the docket for this action.

a. Uncertainties in the emissions datasets
Page 57 of 236

Although the development of the MACT dataset involved 

QA/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, errors

in estimating emissions values and other factors. The emission 

estimates considered in this analysis were generally developed 

from one-time or periodic performance tests that do not reflect 

short-term fluctuations during the course of a year or 

variations from year to year.

The estimates of peak hourly emission rates for the acute 

effects screening assessment were based on a default factor of 

10 applied to the average annual hourly emission rate, which is 

intended to account for emission fluctuations due to normal 

facility operations. 

b. Uncertainties in dispersion modeling

While the analysis employed the 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 between various model options, where possible, model 

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

selected to provide an overestimate of ambient air 

concentrations of the HAP rather than underestimates. However, 
Page 58 of 236

because of practicality and data limitation reasons, some 

factors (e.g., meteorology, building downwash) have the 

potential in some situations to overestimate or underestimate 

ambient impacts. For example, meteorological data were taken 

from a single year (1991), and facility locations can be a 

significant distance from the sites where these data were taken. 

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

The assumption of not considering 

short or long-term population mobility does not bias the 

estimate of the theoretical MIR, nor does it affect the estimate 

of cancer incidence since the total population number remains 

the same. It does, however, affect the shape of the distribution 

of individual risks across the affected population, shifting it 

toward higher estimated individual risks at the upper end and 

reducing the number of people estimated to be at lower risks, 

 

11

Short-term mobility is movement from one micro-environment 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.
Page 59 of 236

thereby increasing the estimated number of people at specific 

risk levels.

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 people in the census block 

who live further 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, but it is an unbiased 

estimate of average risk and incidence.

The assessments evaluate the cancer inhalation risks 

associated with continuous 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 risks posed by a 

given 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 
Page 60 of 236

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 exposures to emissions from these 

sources would not be affected by uncertainty in the length of 

time emissions sources operate.

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 other factors specific to the acute exposure 

assessment. 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, 

 

12

U.S. EPA. National-Scale Air Toxics Assessment for 1996. (EPA 453/R–

01–003; January 2001; page 85.)
Page 61 of 236

meteorology, and human activity patterns. In 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 noncancer 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 the 

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

the 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 variability in dose-response 
Page 62 of 236

relationships 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 also 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, the 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 noncancer reference (RfC and reference dose (RfD)) 

values represent chronic exposure levels that are intended to be 

health-protective 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.
Page 63 of 236

magnitude) of daily oral exposure (RfD) or of a continuous 

inhalation exposure (RfC) 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 

 

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.
Page 64 of 236

a greater tendency to overestimate 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 

“uncertainty factor,” 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 more often they use 

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

based on chemical-specific or health effect-specific information 
Page 65 of 236

(e.g., simple irritation effects do not vary appreciably between 

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).

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 noncancer effects for all 

pollutants emitted by the sources included in this assessment, 

some HAP continue to have no reference values for cancer or 
Page 66 of 236

chronic noncancer or acute effects (see table 3.1-1 of the risk 

assessment document available in the docket for this proposed 

rulemaking). 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. For a group of compounds that are either unspeciated 

or do not have reference values for every individual compound 

(e.g., POM), we conservatively use the most protective reference 

value to estimate risk from individual compounds in the group of 

compounds.

Additionally, chronic reference values for several of the 

compounds included in this assessment are currently under the 

EPA IRIS review, 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 

these reviews are completed prior to our taking final action for 

this source category and a dose-response metric changes enough 

to indicate that the risk assessment supporting this notice may 

significantly understate human health risk. More information 

regarding the dose-response values used in this assessment is 

provided in the Draft Residual Risk Assessment for the Secondary 

Aluminum Production Source Category, which is available in the 

docket.
Page 67 of 236

e. Uncertainties in the multipathway and environmental effects 

screening 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 PBHAP emissions to determine whether a full assessment of the 

multipathway and environmental effects is necessary. Our 

screening methods use worst-case scenarios to determine whether 

multipathway impacts might be important. The results of such a 

process are biased high for the purpose of screening out 

potential impacts. Thus, when individual pollutants or 

facilities screen out, we are confident that the potential for

multipathway impacts is negligible. On the other hand, when 

individual pollutants or facilities do not screen out, it does 

not mean that multipollutant impacts are significant, only that 

we cannot rule out that possibility. For this source category, 

we only performed a worst-case multipathway screening assessment 

for PB-HAP. Thus, it is important to note that potential PB-HAP 

multipathway risks are biased high.

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

this proposal?

In evaluating and developing standards under section 

112(f)(2), as discussed in Section I.A of this preamble, we 
Page 68 of 236

apply a two-step process to address residual risk. In the first 

step, the EPA determines whether 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)16 of 

approximately 1 in 10 thousand [i.e., 100 in 1 million]” (54 FR 

at 38045). In the second step of the process, the 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 one in one

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, the 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 more recent proposals the EPA also presented and 

considered additional measures of health information, such as 

 

16 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.
Page 69 of 236

estimates of the risks associated with the maximum level of 

emissions which might be allowed by the current MACT standards 

(see, e.g., 76 FR 72770, November 25, 2011, 76 FR 72508, 

November 23, 2011, 75 FR 65068, October 21, 2010, and 75 FR 

80220, December 21, 2010). The EPA also discussed and considered 

risk estimation uncertainties. The EPA is providing this same 

type of information in support of the proposed determinations

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 [previous] section 112 is best judged on the basis of a 

broad set of health risk measures and information” (54 FR at

38046). Similarly, with regard to making the ample margin of 

safety determination, as stated in the Benzene NESHAP “[in 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.
Page 70 of 236

The agency acknowledges that the Benzene NESHAP provides

flexibility regarding what factors the EPA might consider in 

making determinations and how these factors might be weighed for 

each source category. In responding to comment on our policy 

under the Benzene NESHAP, the 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 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).
Page 71 of 236

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

weighed in determining acceptability of risks. The Benzene 

NESHAP explained 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” (54 FR 

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

analysis, the EPA stated in the Benzene NESHAP that: “the 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-related factors) vary from source category to source 

category” (54 FR at 38061).

The 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 
Page 72 of 236

category alone (source category risk estimates) and HAP 

emissions from the entire facility at which the covered 

source category is located (facilitywide 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 emissions 

from other facilities that do not include the source category in 

question, 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 noncancer risks, where pollutant-specific exposure health reference 

levels (e.g., Reference Concentrations (RfCs)) are based on the 

assumption that thresholds exist for adverse health effects. 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 
Page 73 of 236

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.”17

While we are interested in placing source category and 

facilitywide 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 

significantly greater associated uncertainties than for the 

source category or facilitywide 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 

 

17 The 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, UESPA/OAQPS entitled, EPA’s 

Actions in Response to the Key Recommendations of the SAB Review of 

RTR Risk Assessment Methodologies.
Page 74 of 236

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). 

C. How did we perform the technology review?

Our technology review focused on the identification and 

evaluation of developments in practices, processes, and control 

technologies that have occurred since the Secondary Aluminum 

Production NESHAP was promulgated. In cases where the technology 

review identified such developments, we conducted an analysis of 

the technical feasibility of applying these developments, along 

with the estimated impacts (costs, emissions reductions, risk 

reductions, etc.) of applying these developments. We then made 

decisions on whether it is appropriate or necessary to propose 

amendments to the 2000 NESHAP to require any of the identified 

developments.

Based on our analyses of the data and information collected 

from industry and the trade organization representing facilities 

subject to the NESHAP, our general understanding of the 
Page 75 of 236

industry, and other available information in the literature on 

potential controls for this industry, we identified several new 

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 development of the 

2000 Secondary Aluminum Production NESHAP.

 Any improvements in add-on control technology or other 

equipment (that were identified and considered during 

development of the 2000 Secondary Aluminum Production 

NESHAP) that could result in significant additional 

emissions reduction.

 Any work practice or operational procedure that was not 

identified or considered during development of the 2000 

Secondary Aluminum Production NESHAP.

 Any process change or pollution prevention alternative that 

could be broadly applied to the industry and that was not 

identified or considered during development of the 2000 

Secondary Aluminum Production NESHAP.

In addition to reviewing the practices, processes, or 

control technologies that were not considered at the time we 

developed the 2000 NESHAP, we reviewed a variety of data sources 
Page 76 of 236

in our evaluation of whether there were additional practices, 

processes, or controls to consider for the Secondary Aluminum 

Production industry. Among the data sources we reviewed were the 

NESHAP for various industries that were promulgated after the 

2000 NESHAP. We reviewed the regulatory requirements and/or 

technical analyses associated with these regulatory actions to 

identify any practices, processes, and control technologies 

considered in these efforts that could possibly be applied to 

emissions sources in the Secondary Aluminum Production source 

category, as well as the costs, non-air impacts, and energy 

implications associated with the use of these technologies. 

Additionally, we requested information from facilities

regarding developments in practices, processes, or control 

technology. Finally, we reviewed other information sources, such 

as State or local permitting agency databases and industrysupported databases. In particular, we consulted the EPA’s 

RACT/BACT/LAER Clearinghouse (RBLC) to identify potential 

technology advances. Control technologies classified as RACT 

(Reasonably Available Control Technology), BACT (Best Available 

Control Technology), or LAER (Lowest Achievable Emissions 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 
Page 77 of 236

agencies. The 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 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 

emissions streams. We searched this database to determine 

whether it contained any practices, processes or control 

technologies for the types of processes covered by the Secondary 

Aluminum Production NESHAP. No such practices, processes or 

control technologies were identified in this database.

D. What other issues are we addressing in this proposal?

In addition to the analyses described above, we also 

reviewed other aspects of the MACT standards for possible 

revision as appropriate and necessary. Based on this review we 

have identified aspects of the MACT standards that we believe 

need revision.

This includes proposing revisions to the startup, shutdown 

and malfunction (SSM) provisions of the MACT rule in order to 

ensure that they are consistent with the court decision in 

Sierra Club v. EPA, 551 F. 3d 1019 (D.C. Cir. 2008). 
Page 78 of 236

We are also proposing changes to the rule related to 

affirmative defense for violation of an emission limit during a 

malfunction. We are proposing other changes to address HF 

emissions, fugitive emissions during testing and numerous 

clarifications and corrections related to the existing 

provisions in the rule. Descriptions of each issue and the 

proposed revision to address the issue are presented in Section 

IV of this preamble.

IV. Analytical Results and Proposed Decisions

This section of the preamble provides the results of our 

RTR for the Secondary Aluminum Production source category and 

our proposed decisions concerning changes to the Secondary 

Aluminum Production NESHAP.

A. What are the results of the risk assessments?

For major sources in the Secondary Aluminum source 

category, we conducted an inhalation risk assessment for all HAP 

emitted. In addition, we performed a facilitywide risk 

assessment for the major sources in the secondary aluminum 

source category. For area sources, we conducted an inhalation 

risk assessment for D/F since this is the only HAP covered by 

the subpart RRR MACT standards at area sources. For all sources, 

we conducted multipathway screening analyses for PB-HAP emitted 

(e.g., D/F). Although there are 53 major sources and 108 area 

sources covered by the subpart RRR MACT standards, 52 major 
Page 79 of 236

sources and 103 area sources were modeled due to the other 

sources’ lack of equipment subject to the applicable emission 

standards. Results of the risk assessment are presented briefly 

below and in more detail in the residual risk documentation 

referenced in Section III of this preamble, which is available 

in the docket for this action.

Table 4 of this preamble provides an overall summary of the 

results of the inhalation risk assessment.

Table 4. Secondary Aluminum Production Inhalation Risk 

Assessment Results

Category 

& No of 

Faciliti

es 

Modeled

Maximum

Individual

Cancer Risk

(in 1 million)1

Estimate

d 

Populati

on

at 

increase

d Risk 

of 

cancer ≥ 

1 in 1 

Million4

Estimat

ed 

Annual

Cancer

Inciden

ce 

(cases 

per 

year)4

Maximum

Chronic Noncancer

TOSHI2

Worstcase 

Maximum 

Refined 

Screeni

ng 

Acute 

Noncancer 

HQ3

Based 

on 

Actual 

Emissio

ns 

Level

Based 

on 

Allowab

le 

Emissio

ns 

Level

Based 

on 

Actual 

Emissio

ns 

Level

Based 

on 

Allowab

le 

Emissio

ns 

Level

Major 

Source 

(52) 1 20 2 0.0006 0.05 1

HQREL 

0.7 

(HCl)

Area 

Source 

(103)

0.4 6 0 0.0006 0.0003 0.005 -

Facility

-wide 

Major 

Source

20 - 62,000 0.006 0.4 - -

1 Estimated maximum individual excess lifetime cancer risk due to HAP 

emissions from the source category.

We did not have allowable emissions information at the facilitywide level, 

therefore, risk estimates based on facilitywide allowable emissions were not 

calculated.

2 Maximum TOSHI. The target organ with the highest TOSHI for the secondary 

aluminum source category is the respiratory system. 

3 There is no acute dose-response value for dioxins, thus an acute HQ value 

for area sources was not calculated. See Section III.B of this preamble for 

explanations of acute dose-response values.
Page 80 of 236

4 These estimates are based on actual emissions.

The results of the chronic inhalation cancer risk 

assessment for major sources indicate that the maximum lifetime 

individual cancer risk, considering actual emissions, could be 

up to 1 in 1 million, driven by dioxin emissions. The maximum 

cancer risks for this source category exceeded a cancer risk of 

1 in 1 million at 1 of 52 facilities. The total estimated cancer 

incidence from this source category based on actual emission 

levels is 0.0006 excess cancer cases per year, or one excess 

case in every 1,666 years. No people were estimated to have 

cancer risks above 10 in a million and approximately 2 people

were estimated to have cancer risks above 1 in 1 million 

considering all major source facilities in this source category. 

Based on MACT-allowable emissions for the major sources in this 

category, the MIR could be up to 20 in 1 million. 

With respect to chronic inhalation noncancer risk from 

major sources, we estimate a maximum TOSHI value of 0.05 for the 

Secondary Aluminum source category, primarily from hydrochloric 

acid from Group 1 furnaces. Considering MACT-allowable 

emissions, this maximum TOSHI value is estimated to be 1.

Moreover, our worst-case highest acute screening value for major 

sources was 0.7 based on the REL for HCL.
Page 81 of 236

Considering facility wide emissions at the 52 major 

sources, the MIR is estimated to be up to 20 in 1 million, the 

estimated annual incidence is 0.006 cases per year, and the 

chronic non-cancer TOSHI value is calculated to be 0.4.

In addition, we estimated risks associated with dioxin 

emissions at the 103 area sources in the Secondary Aluminum 

Production source category. The results of the chronic 

inhalation cancer risk assessment indicate that the maximum 

lifetime individual cancer risk could be up to 0.4 in 1 million

and an estimated annual incidence of 0.0006 cases per year. 

Considering MACT-allowable emissions, the MIR could be up to 6 

in 1 million. With respect to chronic inhalation noncancer risk 

from D/F emissions at area sources, we estimate a maximum TOSHI 

value of 0.0003. Considering MACT-allowable emissions, this 

maximum TOSHI value is estimated to be 0.005 for area sources. 

In addition to the analyses presented above, to screen for 

potential multipathway effects from emissions of PB-HAP (such as 

cadmium, dioxins and PAHs) we compared actual emission rates 

from major source facilities in this source category to the 

screening values for these PB HAP described above (see Section 

III (A)(4)). For dioxins, we also screened for potential 

multipathway effects from emissions of D/F from area sources by 

comparing the estimated actual emission rates from these area 

sources to the screening value for D/F described above. (see 
Page 82 of 236

Risk Assessment Document Appendix 4 for a more detailed 

discussion of screening emission rates). Results of this worstcase screen estimate that actual POM emissions from 10 of the 52

major source facilities exceed the POM screening emission rate. 

With respect to D/F, of the 46 major sources that emitted 

dioxins, 39 exceeded our screening emission rate. Similarly, 76 

out of 103 area sources exceeded our D/F screening rate. These

exceedances of the worst-case multipathway screening level for 

POM and dioxins indicate that there may be potential 

multipathway impacts of concern due to emissions of POM and 

dioxins. In general, emission rates below the worst-case 

multipathway screening level indicate no significant potential 

for multipathway-related health or environmental effects; 

whereas emission levels above this worst-case screening level 

only indicate the potential for multipathway-related health or 

environmental risks of concern based on a worst-case scenario. 

Thus, we note that these screening values are biased high for 

purposes of screening and are subject to significant 

uncertainties. As such, they do not represent refined estimates 

of risk and thus, do not necessarily indicate that potential 

multipathway risks from the source category may be a concern; we 

can only say that we cannot rule them out.

With respect to the potential for adverse environmental 

effects from non PB-HAP, we note that for both major and area 
Page 83 of 236

sources all chronic non-cancer HQ values for all pollutants 

considering actual emissions are well below 1 using human health 

reference values. Thus, we believe that it is unlikely that 

adverse environmental effects would occur at the actual HAP 

concentrations estimated in our human health risk assessment. 

B. What are our proposed decisions regarding risk acceptability 

and ample margin of safety?

1. Risk acceptability

As noted in Section III.C of this preamble, we weigh all 

health risk factors in our risk acceptability determination, 

including the MIR, the numbers of persons in various risk 

ranges, cancer incidence, the maximum noncancer HI, the maximum 

acute noncancer hazard, the extent of noncancer risks, the 

potential for adverse environmental effects, distribution of 

risks in the exposed population, and risk estimation 

uncertainties (54 FR 38044, September 14, 1989).

For the Secondary Aluminum Production source category, the 

risk analysis indicates that the cancer risks to the individual 

most exposed could be up to 1 in 1 million due to actual 

emissions and up to 20 in 1 million due to MACT-allowable 

emissions. These risks are considerably less than 100 in 1 

million, which is the presumptive upper limit of acceptable 

risk. The risk analysis also shows very low cancer incidence 

(0.0006 cases per year), as well as no potential for adverse 
Page 84 of 236

chronic or acute non-cancer health effects. In addition, the 

risk assessment indicates no significant potential for adverse 

environmental effects.

In addition to the analyses presented above, to screen for 

potential multipathway effects from emissions of D/F and POM, we 

compared the estimated actual emission rates from facilities in 

this source category to the multipathway screening levels

described in section III.B. With respect to POM and dioxins, 

both major and area sources in the category exceeded our worstcase screening levels. However, we note that this is a worstcase conservative screening level analysis, therefore these 

results are biased high for purposes of screening and are 

subject to significant uncertainties. Moreover, we note that due 

to data limitations we were unable to further refine this worstcase screening scenario. As such, they do not necessarily 

indicate that significant multipathway risks actually exist at 

secondary aluminum facilities, only that we cannot rule them out 

as a possibility. With regard to facilitywide multipathway risk, 

based on the low level of risk identified for the source 

category, a facilitywide multipathway risk analysis was not 

conducted for this source category.

Considering all of the health risk information and factors

discussed above, including the uncertainties discussed in 

section IV.A.7 of this preamble, we propose that the risks from 
Page 85 of 236

the Secondary Aluminum Production source category are 

acceptable.

2. Ample margin of safety analysis

We next considered whether the existing MACT standard 

provides an ample margin of safety to protect public health. 

Under the ample margin of safety analysis, we evaluated the cost 

and feasibility of available control technologies and other 

measures (including the controls, measures and costs reviewed 

under the technology review) that could be applied in this 

source category to further reduce the risks (or potential risks) 

due to emissions of HAP identified in our risk assessment, along 

with all of the health risks and other health information 

considered in the risk acceptability determination described 

above. In this analysis we considered the results of the 

technology review, risk assessment and other aspects of our MACT 

rule review to determine whether there are any cost-effective 

controls or other measures that would reduce emissions further 

to provide an ample margin of safety with respect to the risks 

associated with these emissions. 

For POM, THC and metal HAP emissions, our risk analysis 

indicated very low potential for risk from the facilities in the 

source category. Our technology review did not identify any new 

practices, controls or process options that are being used in 

this industry or in other industries that would be cost-
Page 86 of 236

effective for further reduction of these emissions. Based on the 

estimated low risk levels and absence of new practices or 

control options, we conclude that the provisions of the current 

MACT provide for an ample margin of safety for public health 

with respect to emissions of POM, THC and metal HAP.

Our multipathway screening analysis results indicated 

exceedances of the worst-case screening levels which do not 

necessarily indicate any risks, however, they do suggest a 

potential for risks that cannot be ruled out. To evaluate the 

potential to reduce D/F emissions to ensure an ample margin of 

safety, our analysis for D/F focused on two options: 1) lowering 

the existing D/F limit from 15 to 10 μg TEQ/Mg feed for Group 1 

furnaces processing other than clean charge at all facilities;

and 2) lowering the existing D/F limit for Group 1 furnaces 

processing other than clean charge, after applying a 

subcategorization based on facility production capacity. The 

lower D/F limits potentially could be met by using an activated 

carbon injection (ACI) system. With regard to the option of 

lowering the emission limit to 10 μg TEQ/Mg feed for Group 1 

furnaces handling other than clean charge, we estimate that 

about 11 facilities would need to reduce their D/F emissions and 

that the costs would be about $5.9 million in total capital 

costs with total annualized costs of about $2.7 million. This 
Page 87 of 236

option would achieve an estimated 1.66 grams TEQ reduction of 

D/F emissions with an overall cost-effectiveness of about $1.61 

million per gram D/F TEQ. The second option of lowering the 

emission limit based on a subcategorization according to 

facility production capacity yielded cost-effectiveness 

estimates of greater than $1 million per gram D/F TEQ reduced.

Furthermore, our analysis indicates that these options would not 

result in significant emissions reductions and would not, 

therefore, result in significant changes to the potential risk 

levels. After considering the costs and the small reductions 

that would be achieved, we have decided not to propose any of 

these options. For more information, please refer to the Draft 

Technical Document for the Secondary Aluminum Production Source 

Category that is available in the public docket for this 

proposed rulemaking.

We also evaluated possible options based on work practices 

to achieve further emissions reductions. The current subpart RRR 

NESHAP includes work practices to minimize D/F emissions which 

include scrap inspection, limitations on materials processed by 

group 2 furnaces, temperature and residence time requirements 

for afterburners controlling sweat furnaces, labeling 

requirements, capture/collection requirements, and requirements 

for an operations, maintenance and monitoring plan that contains 

details on the proper operation and maintenance of processes and 
Page 88 of 236

control equipment. We searched for and evaluated other possible 

work practices such as good combustion practices, better scrap 

inspection and cleaning, and process monitoring. However, none 

of these potential work practices were determined to be feasible 

and effective in reducing D/F emissions for this source 

category. Thus, we did not identify any feasible or applicable 

work practices for this industry beyond those that are currently 

in the MACT rule. Further detail on work practices and control 

options are provided in the Draft Technology Review for the 

Secondary Aluminum Production Source Category, which is 

available in the docket.

In accordance with the approach established in the Benzene 

NESHAP, we weighed all health risk information and factors 

considered in the risk acceptability determination, including 

uncertainties, along with the cost and feasibility of control 

technologies and other measures that could be applied in this 

source category, in making our ample margin of safety 

determination. In summary, we did not identify any costeffective approaches to further reduce POM, THC, metal HAP or 

D/F emissions beyond the reductions that are already being 

achieved by the current NESHAP. Further, our analysis indicates 

that none of the options considered would result in significant 

emissions reductions and would not, therefore, result in 

significant changes to the potential risk levels. 
Page 89 of 236

Because of the high cost associated with the use of 

activated carbon injection systems and because work practices 

are already required to help ensure low emissions, we propose 

that the existing MACT standards provide an ample margin of 

safety to protect public health and prevent an adverse 

environmental effect.

C. What are the results and proposed decisions based on our 

technology review?

As described above, the typical controls used to minimize 

emissions at secondary aluminum facilities include fabric 

filters for control of PM from aluminum scrap shredders; 

afterburners for control of THC and D/F from thermal chip 

dryers; afterburners plus lime-injected fabric filters for 

control of PM, HCl, THC, and D/F from scrap dryers/delacquering 

kilns/decoating kilns; afterburners for control of D/F from 

sweat furnaces; fabric filters for control of PM from dross-only 

furnaces and rotary dross coolers; lime-injected fabric filters 

for control of PM and HCl from in-line fluxers; and limeinjected fabric filters for control of PM, HCl and D/F from 

group 1 furnaces. There have been some developments in 

practices, processes, or control technologies that have been 

implemented in this source category since promulgation of the 

current NESHAP. However, based on information available to the 

EPA, these technologies do not clearly reduce HAP emissions 
Page 90 of 236

relative to technologies that were considered by the EPA when 

promulgating the Secondary Aluminum Production NESHAP in 2000. 

In addition, we evaluated whether lime-injection fabric filters 

with activated carbon injection could be used to further reduce 

D/F from group 1 furnaces in a cost-effective manner.

At least one company supplies multichamber furnaces that 

combine the functions of a delacquering kiln and a melting 

furnace. At least 16 of these furnaces are in operation in 

Europe, Asia and the Middle East, however emission test data for 

these facilities is not available. One furnace of this type is 

presently operating in the U. S. and is permitted as a group 1 

furnace handling other than clean charge. 

However, the limited D/F emission test data available for 

the one operating U.S. multichamber furnace is within the range 

of test data for Group 1 furnaces and delacquering kilns that 

are in compliance with subpart RRR using control technologies 

considered by the EPA in the subpart RRR NESHAP. Based on 

available information it is not clear that this technology would 

reduce HAP emissions relative to technologies that were 

considered by the EPA in promulgating the subpart RRR NESHAP and 

are already used by other facilities. Based on our analysis, we 

conclude that it would not be appropriate at this time to revise 

subpart RRR standards based on use of this technology.
Page 91 of 236

Eddy current separators are used to separate a concentrated 

aluminum fraction from a heterogeneous scrap feed. These units 

operate at ambient temperature and emit no D/F or other gaseous 

pollutants. They are used on the material output from mechanical 

shredders that shred automobiles and appliances (not on the 

scrap shredders used in the secondary aluminum industry). These 

units can potentially decrease the need for sweat furnaces. 

However, the product of eddy current separators is not clean 

charge, as with a sweat furnace. Therefore, the product of eddy 

current separators must undergo further processing to produce 

clean charge, and it is not possible to directly compare eddy 

current separators with sweat furnaces. 

Catalytic filtration systems, including catalytic filter 

bags, are available to reduce D/F emissions. These bags 

incorporate an expanded polytetrafluoroethylene membrane coated 

with a precious metal catalyst which promotes the oxidation of 

D/F. The manufacturer claims that this system is installed in 

over 100 applications around the world, including at least 1 

secondary aluminum processing plant. However, no respondents to 

our all-company ICR reported using this technology and we have 

no data on the D/F emission levels that can be achieved at 

secondary aluminum production facilities using this technology.

Therefore we cannot conclude that they are more effective at 

reducing D/F emissions than the control technologies considered 
Page 92 of 236

by the EPA in the 2000 subpart RRR NESHAP. We therefore 

conclude, based on information available to the EPA, that 

catalytic filtration systems are not at present a demonstrated 

control technology that should be used as the technical basis to 

require more stringent emission limits for the secondary

aluminum production source category.. 

We also evaluated the potential to lower D/F emissions 

under the technology review by lowering the emissions limits 

based on the broader use of activated carbon injection 

technology. Under this analysis, we evaluated the same approach 

that was evaluated under the ample margin of safety analysis 

described in section IV.B. In summary, we evaluated two main 

options, as follows: 1) lower the existing D/F limit from 15 to 

10 μg TEQ/Mg feed for Group 1 furnaces processing other than 

clean charge at all facilities; and 2) lower the existing D/F 

limit for Group 1 furnaces processing other than clean charge, 

after applying a subcategorization based on facility production 

capacity. The lower D/F emissions limits potentially could be 

met by using an activated carbon injection (ACI) system. With 

regard to the option of lowering the emission limit to 10 μg 

TEQ/Mg feed for Group 1 furnaces handling other than clean 

charge, we estimate that about 11 facilities would need to 

reduce their D/F emissions and that the costs would be about 
Page 93 of 236

$5.9 million in total capital costs with total annualized costs 

of about $2.7 million. This option would achieve an estimated 

1.66 grams TEQ reduction of D/F emissions with an overall costeffectiveness of about $1.61 million per gram D/F TEQ. The 

second option of lowering the emission limit based on a 

subcategorization according to facility production capacity 

yielded cost-effectiveness estimates of greater than $1 million 

per gram D/F TEQ reduced. Furthermore, our analysis indicates 

that these options would not result in significant emissions 

reductions. After considering the compliance costs and the small

associated emission reductions that would be achieved, we are 

not proposing revised subpart RRR standards based on either of 

these options that rely on the use of ACI injection technology 

under section 112(d)(6) of the CAA.

Overall, based on our review of developments in practices, 

processes, and control technologies, we have not identified any 

control approaches that clearly reduce HAP emissions in a costeffective manner relative to technologies that were available 

and considered by the EPA at the time of promulgation of the 

Secondary Aluminum Production NESHAP in 2000. Therefore, we are 

not proposing any revisions to the NESHAP as a result of our 

technology review. Additional details regarding these analyses 

can be found in the following technical document for this action 
Page 94 of 236

which is available in the docket: Draft Technology Review for 

the Secondary Aluminum Production Source Category.

D. What other actions are we proposing?

This section discusses revisions that are being proposed to 

correct and clarify provisions in the rule as well as 

solicitations of comments and requests for additional 

information. We are proposing revisions to the rule to address 

SSM provisions within the rule that were vacated by a court 

ruling and we are adding a requirement for electronic submission 

of all test results to increase the ease and efficiency of data 

submittal and improve data accessibility. In addition, since 

promulgation of the subpart RRR NESHAP in March 2000 (65 FR 

15689), we have received recommendations and suggestions from

individual representatives from state regulatory agencies and 

industry, as well as within EPA, to correct errors in the rule 

and to help clarify the intent and implementation of the rule.

Table 5 provides a summary of these proposed changes. Following 

Table 5 are detailed descriptions of the proposed revisions.

Table 5. Summary of Technical Corrections/Clarifications to the 

Secondary Aluminum Production NESHAP

Correction/Clarification Description

1. Startup, shutdown and 

malfunctions (63.1503,

63.1506(l) and (m),

63.1506(q),and 63.1520) 

 Addresses vacated General 

Provision (GP) requirements.

 Deletes references to vacated 

GP sections.

 Requires all sources to comply 

with emission limits including 

during periods of startup and
Page 95 of 236

shutdown.

 Adds definition for 

affirmative defense. Adds 

affirmative defense provisions

for malfunctions.

2. Electronic Reporting 

(63.1516(b)(3))

 Requires owners and operators 

to report performance test 

results through the EPA 

Electronic Reporting System 

(ERT).

3. ACGIH Guidelines  The capture and collection 

provision of §63.1506(c)(1)

that reference the ”Industrial 

Ventilation: A Manual of 

Recommended Practice”, is 

revised to allow 23rd or 27th

Editions and take out specific 

references to chapters 3 and 

5. 

 Requests comments on methods 

other than ACGIH Guidelines to 

ensure capture and collection

and alternatives to the 

currently required hooding 

requirements.

4. Scrap Inspection Program 

for Group 1 Furnace without 

Add-on Air Pollutions 

Control Devices (63.1510(p))

 Considering improvements to

scrap inspection program.

 Requesting comments and 

information.

5. Multiple Tests for Worst 

Case Scenarios

(63.1511(b)(6))

 Clarifies that multiple tests 

may be required to reflect the 

range of emissions likely for 

each regulated pollutant. 

6. Lime Injection Rate 

Verification (63.1510(i)(4))

 Requires verification of the 

lime mass injection rate at 

least once per month. 

7. Flux Monitoring

(63.1510(j)(4))

 Clarifies that solid flux must

be tracked at each addition 

during the cycle or time 

period used in the performance 

test.

8. Cover fluxes (63.1503)  Clarifies definition of cover 

flux.

9. Capture and Collection 

Systems (63.1503)

 Adds a definition of capture 

and collection systems.
Page 96 of 236

10. Bale Breakers (63.1503)  Adds a definition of a bale 

breaker to clarify that a bale 

breaker is not a scrap 

shredder.

11. Bag Leak Detection 

Systems (BLDS)

(63.1510(f)(1)(ii))

 Removes reference to an 

outdated guidance document and 

requires use of manufacturer’s 

maintenance and operating 

instructions.

12. Sidewell Furnaces

(63.1510(n)(1))

 Requires visual inspection 

after each tap rather than 

after each charge 

 Allows other means of 

measuring molten metal level

13. Testing Representative 

Units (63.1511(f)(6))

 Clarifies that all performance 

test runs must be conducted on

the same affected source or 

emission unit.

14.Inital Performance Tests

(63.1511(b))

 Revises performance test 

requirements to allow 180 days

to conduct initial performance 

test consistent with GP.

15. Definition of Scrap 

Dryer/Delacquering

Kiln/Decoating Kiln and 

Scrap Shredder (63.1503)

 Clarifies definition of Scrap 

Dryer/Delacquering/Decoating 

Kiln to include delamination 

of aluminum from paper or 

plastic.

 Clarifies definition of scrap 

shredder to include 

granulation and shearing.

16. Transporting metal

(63.1503)

 Clarifies definition of Group 

2 furnace to exclude pots used 

to transport metal.

17. Specifications for 

Cleaning Processes

 Not proposing cleaning 

specifications at this time.

 Invites comments and solicits 

information on appropriate 

cleaning procedures.

18. HF Emissions Compliance 

Provisions (63.1503, 

63.1505, 63.1511(c)(9), 

63.1513)

 Adds definition of HF.

 Adds emissions standard for 

HF.

 Requires EPA Method 26A for 

measurement of HF.

19. Uncontrolled furnaces  Requires owner/operators with 
Page 97 of 236

that do not Comply with 

ACGIH Hooding Guidelines

(63.1512(e)(4))

uncontrolled group 1 furnaces 

to construct hoods for 

performance testing to 

demonstrate compliance, or 

assume 67 percent capture 

efficiency if hooding does not 

meet ACGIH guidelines.

 Seeks comments on alternative 

approaches.

20. Clarify the possible 

Number of SAPUs (63.1503)

 Revises “SAPU” definition to 

clarify there can be more than 

1 new SAPU.

21. Aluminum Scrap 

Containing Anodizing Dyes or 

Sealants (63.1503)

 Clarifies “clean charge”

definition to exclude anodized 

material that contains dyes or 

sealants that contain organic 

material.

22. Afterburner Residence 

Time (63.1503)

 Clarifies “residence time” 

definition to include 

refractory lined ductwork up 

to the control thermocouple.

23. SAPU Feed/Charge Rate

(63.1505(k))

 Clarifies that daily 

throughput must be used to 

calculate allowable emissions 

within the SAPU.

24. Changing Furnace 

Classifications (§63.1514)

 Allows owners/operators to 

change furnace 

classifications.

 Specifies requirements for 

changing.

25. Dross Only Versus 

Dross/Scrap Furnaces

 Clarifies that 

owners/operators have the 

option to conduct performance 

tests under different 

operating conditions to 

address charge/flux changes.

26. Annual Hood Inspections

(63.1510(d)(2))

 Clarifies that annual hood 

inspections include flow rate 

measurements.

27. Applicability of Rule to 

Area Sources (63.1506(a), 

63.1510(a))

 Clarifies which operating, 

monitoring and other standards 

apply to area sources.

28. Altering Parameters 

during Testing with New 

Scrap Streams

 Clarifies that

owners/operators can deviate

from established parametric 
Page 98 of 236

(63.1511(b)(1)) limits during performance 

testing being done to 

establish new parametric 

limits.

29. Controlled Furnaces that 

are Temporarily Idled

(63.1506(q)(5))

 Allows control device for 

furnaces to be shut down if 

furnace will remain idle for 

24 hours or longer.

30. Annual Compliance 

Certification for Area 

Sources (63.1516(c))

 Clarifies that area sources 

must submit an annual 

compliance certification.

1. Startup, shutdown and malfunctions

The United States Court of Appeals for the District of 

Columbia Circuit vacated portions of two provisions in the EPA’s 

CAA Section 112 regulations governing the emissions of HAP 

during periods of startup, shutdown and malfunction (SSM). 

Sierra Club v. EPA, 551 F.3d 1019 (D.C. Cir. 2008). 

Specifically, the Court vacated the SSM exemption contained in 

40 CFR 63.6(f)(1) and 40 CFR 63.6(h)(1), that are part of a 

regulation, commonly referred to as the “General Provisions 

Rule,” that the EPA promulgated under CAA section 112. 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, the EPA is 

proposing standards in this rule that apply at all times. We are 
Page 99 of 236

also proposing several revisions to Appendix A to subpart RRR of 

part 63 (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 requirements related to the SSM 

exemption. The 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, the EPA has taken into 

account startup and shutdown periods and is proposing standards 

for startup and shutdown periods for all process units.

We are proposing that the subpart RRR standards apply at 

all times, including periods of startup and shutdown. Because 

the scrap processed at secondary aluminum production facilities 

is the source of emissions, we expect that emissions during 

startup and shutdown would be no higher and probably much lower 

than emissions during normal operations since no scrap would be 

processed. We know of no reason why the existing standards 

should not apply at all times. For production processes in the 

secondary aluminum production source category where the 
Page 100 of 236

standards are expressed in units of pounds per ton of feed or 

similar units (i.e. thermal chip dyers, scrap dryer/delacquering 

kiln/decoating kilns, dross-only furnaces, in-line fluxers using 

reactive flux, and group 1 furnaces), we are proposing certain 

methods for demonstrating compliance with those limits, as 

discussed further in the Technical Document for the Secondary 

Aluminum Production Source Category that is available in the 

docket for this proposed rulemaking. 

We solicit comment on the proposed standards during startup 

and shutdown periods. Specifically, for those processes that 

have production-based limits (i.e., thermal chip dyers, scrap 

dryer/delacquering kiln/decoating kilns, dross-only furnaces, 

in-line fluxers using reactive flux, and group 1 furnaces), we 

solicit comment as to whether work practices under section 

112(h) of the CAA should be applied during startup and shutdown. 

If you believe work practices would be appropriate for such 

processes, please explain how the requirements of section 

112(h)(2) are met and identify any work practices that would be 

effective in limiting HAP emissions during periods of startup 

and shutdown for such processes. 

For these processes (thermal chip dryers, scrap 

dryers/delacquering kilns/decoating kilns, dross-only furnaces,

group 1 furnaces, in-line fluxers, dross only furnaces, sweat 

furnaces, and group 2 furnaces), startup begins with ignition 
Page 101 of 236

and equipment warming from a cold start or a complete shutdown, 

using natural gas or other clean fuel. At the point that feed is 

introduced, startup ends and the process is in normal operation. 

Similarly for shutdown periods, when an operator halts the 

introduction of feed or charge to, and has removed all product 

(e.g., tapped a furnace), the shutdown phase has begun. For more 

information about the application of subpart RRR standards to 

periods of Startup and shutdown, including revised methods to 

demonstrate compliance, see the Technical Support Document for 

the Secondary Aluminum Production Source Category that is 

available in the docket for this proposed rulemaking.

Periods of startup, normal operations, and shutdown are all 

predictable and routine aspects of a source’s operation. 

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 usual manner * * *” (40 CFR 

63.2). The EPA has determined that CAA section 112 does not 

require that emissions that occur during periods of malfunction

be factored into development of CAA section 112 standards. Under 

section 112, emissions standards for new sources must be no less 

stringent than the level “achieved” by the best controlled 

similar source and for existing sources generally must be no 

less stringent than the average emission limitation “achieved” 
Page 102 of 236

by the best performing 12 percent of sources in the category. 

There is nothing in section 112 that directs the agency to 

consider malfunctions in determining the level “achieved” by the 

best performing or best controlled sources when setting emission 

standards. Moreover, while the EPA accounts for variability in 

setting emission standards consistent with the section 112 case 

law, nothing in that case law requires the agency to consider 

malfunctions as part of that analysis. Section 112 of the CAA 

uses the concept of “best controlled” and “best performing” unit 

in defining the level of stringency that CAA section 112 

performance standards must meet. Applying the concept of “best 

controlled” or “best performing” to a unit that is 

malfunctioning presents significant difficulties, as 

malfunctions are sudden and unexpected events.

Further, accounting for malfunctions would be difficult, if 

not impossible, given the myriad different types of malfunctions 

that can occur across all sources in the category and given the 

difficulties associated with predicting or accounting for the 

frequency, degree and duration of various malfunctions that 

might occur. As such, the performance of units that are 

malfunctioning is not “reasonably” foreseeable. See, e.g.,

Sierra Club v. EPA, 167 F. 3d 658, 662 (D.C. Cir. 1999) (The EPA 

typically has wide latitude in determining the extent of datagathering necessary to solve a problem. We generally defer to an 
Page 103 of 236

agency's decision to proceed on the basis of imperfect 

scientific information, rather than to "invest the resources to 

conduct the perfect study."). See also, 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”). In addition, the goal of a best controlled or best 

performing source is to operate in such a way as to avoid 

malfunctions of the source, and accounting for malfunctions 

could lead to standards that are significantly less stringent 

than levels that are achieved by a well-performing nonmalfunctioning source. The EPA’s approach to malfunctions is 

consistent with CAA section 112 and is a reasonable 

interpretation of the statute.

In the event that a source fails to comply with the 

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

malfunction event, the EPA would determine an appropriate 

response based on, among other things, the good faith efforts of 

the source to minimize emissions during malfunction periods, 
Page 104 of 236

including preventative and corrective actions, as well as root 

cause analyses to ascertain and rectify excess emissions. The 

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, the EPA recognizes that even equipment that is 

properly designed and maintained can sometimes fail and that 

such failure can sometimes cause a violation of the relevant 

emission standard. (See, e.g., State Implementation Plans: 

Policy Regarding Excessive Emissions During Malfunctions, 

Startup, and Shutdown (Sept. 20, 1999); Policy on Excess 

Emissions During Startup, Shutdown, Maintenance, and 

Malfunctions (Feb. 15, 1983)). The EPA is therefore proposing to 

add to the final rule an affirmative defense to civil penalties 

for violations of emission limits that are caused by 

malfunctions. See 40 CFR 63.1503 (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 
Page 105 of 236

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 40 CFR 63.1520 (See 40 CFR 22.24). The 

criteria ensure that the affirmative defense is available only 

where the event that causes a violation 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, infrequent, and unavoidable 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 40 CFR §63.1506(a)(5) and §1520(a)(8) 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 
Page 106 of 236

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 22.27).

The EPA included an affirmative defense in the proposed

rule in an attempt to balance a tension, inherent in many types 

of air regulation, to ensure adequate compliance while 

simultaneously recognizing that despite the most diligent of 

efforts, emission limits may be exceeded under circumstances 

beyond the control of the source. The EPA must establish 

emission standards that “limit the quantity, rate, or 

concentration of emissions of air pollutants on a continuous 

basis.” 42 USC §7602(k) (defining “emission limitation and 

emission standard”). See generally Sierra Club v. EPA, 551 F.3d 

1019, 1021 (D.C. Cir. 2008). Thus, the EPA is required to ensure 

that section 112 emissions limitations are continuous. The 

affirmative defense for malfunction events meets this 

requirement by ensuring that even where there is a malfunction, 

the emission limitation is still enforceable through injunctive 

relief. While “continuous” limitations, on the one hand, are 

required, there is also case law indicating that in many 

situations it is appropriate for the EPA to account for the 

practical realities of technology. For example, in Essex 

Chemical v. Ruckelshaus, 486 F.2d 427, 433 (D.C. Cir. 1973), the 
Page 107 of 236

D.C. Circuit acknowledged that in setting standards under CAA 

Section 111 “variant provisions” such as provisions allowing for 

upsets during startup, shutdown and equipment malfunction 

“appear necessary to preserve the reasonableness of the 

standards as a whole and that the record does not support the 

‘never to be exceeded’ standard currently in force.” See also, 

Portland Cement Association v. Ruckelshaus, 486 F.2d 375 (D.C. 

Cir. 1973). Though intervening case law such as Sierra Club v. 

EPA and the CAA 1977 amendments undermine the relevance of these 

cases today, they support the EPA’s view that a system that 

incorporates some level of flexibility is reasonable. The 

affirmative defense simply provides for a defense to civil 

penalties for excess emissions that are proven to be beyond the 

control of the source. By incorporating an affirmative defense, 

the EPA has formalized its approach to upset events. In a Clean 

Water Act setting, the Ninth Circuit required this type of 

formalized approach when regulating “upsets beyond the control 

of the permit holder.” Marathon Oil Co. v. EPA, 564 F.2d 1253, 

1272-73 (9th Cir. 1977). But see, Weyerhaeuser Co. v. Costle, 590 

F.2d 1011, 1057-58 (D.C. Cir. 1978) (holding that an informal 

approach is adequate). The affirmative defense provisions give 

the EPA the flexibility to both ensure that its emission 

limitations are “continuous” as required by 42 U.S.C. § 7602(k), 
Page 108 of 236

and account for unplanned upsets and thus support the 

reasonableness of the standard as a whole.

Specifically, we are proposing the following rule changes:

 Add general duty requirements in 40 CFR §63.1506(a)(5) and 

§63.1520(a)(8) to replace General Provision requirements 

that reference vacated SSM provisions.

 Revise language in 40 CFR §63.1515 that references 

notifications for SSM events.

 Add paragraphs in 40 CFR §63.1520 concerning the reporting 

of malfunctions as part of the affirmative defense 

provisions.

 Add paragraph in 40 CFR §63.1516(d) regarding reporting of 

malfunctions and revised §63.1516(b)(1)(v) to remove 

reference to malfunction.

 Revise paragraph in 40 CFR §63.1510(s)(iv) to remove 

reference to malfunction.

 Add paragraphs in 40 CFR §63.1517 concerning the keeping of 

certain records relating to malfunctions as part of the 

affirmative defense provisions.

 Revise Appendix A to subpart RRR of part 63 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.
Page 109 of 236

2. Electronic reporting.

The EPA must have performance test data to conduct 

effective reviews of CAA sections 112 and 129 standards, as well 

as for many other purposes including compliance determinations, 

emissions factor development and annual emissions rate 

determinations. In conducting these required reviews, the EPA

has found it ineffective and time consuming, not only for us, 

but also for regulatory agencies and source owners and 

operators, to locate, collect, and submit performance test data 

because of varied locations for data storage and varied data 

storage methods. In recent years, though, stack testing firms 

have typically collected performance test data in electronic 

format, making it possible to move to an electronic data 

submittal system that would increase the ease and efficiency of 

data submittal and improve data accessibility.

Through this proposal the EPA is presenting a step to 

increase the ease and efficiency of data submittal and improve 

data accessibility. Specifically, the EPA is proposing that 

owners and operators of Secondary Aluminum Production facilities 

submit electronic copies of required performance test reports to 

the EPA’s WebFIRE database. The WebFIRE database was constructed 

to store performance test data for use in developing emissions 

factors. A description of the WebFIRE database is available at 

http://cfpub.epa.gov/oarweb/index.cfm?action=fire.main.
Page 110 of 236

As proposed above, data entry would be through an 

electronic emissions test report structure called the Electronic 

Reporting Tool. The ERT would generate an electronic report 

which would be submitted using the Compliance and Emissions Data 

Reporting Interface (CEDRI). The submitted report would be 

transmitted through EPA’s Central Data Exchange (CDX) network 

for storage in the WebFIRE database making submittal of data 

very straightforward and easy. A description of the ERT can be 

found at http://www.epa.gov/ttn/chief/ert/index.html and CEDRI 

can be accessed through the CDX website (www.epa.gov/cdx). The 

proposal to submit performance test data electronically to the 

EPA would apply only to those performance tests conducted using 

test methods that will be supported by the ERT. The ERT contains 

a specific electronic data entry form for most of the commonly 

used EPA reference methods. A listing of the pollutants and test 

methods supported by the ERT is available at 

http://www.epa.gov/ttn/chief/ert/index.html. We believe that 

industry would benefit from this proposed approach to electronic 

data submittal. Having these data, the EPA would be able to 

develop improved emissions factors, make fewer information 

requests and promulgate better regulations.

One major advantage of the proposed submittal of 

performance test data through the ERT is a standardized method 

to compile and store much of the documentation required to be 
Page 111 of 236

reported by this rule. Another advantage is that the ERT clearly 

states what testing information would be required. Another 

important proposed benefit of submitting these data to the EPA

at the time the source test is conducted is that it should 

substantially reduce the effort involved in data collection 

activities in the future. When the EPA has performance test data 

in hand, there will likely be fewer or less substantial data 

collection requests in conjunction with prospective required 

residual risk assessments or technology reviews. This would 

result in a reduced burden on both affected facilities (in terms 

of reduced manpower to respond to data collection requests) and 

the EPA (in terms of preparing and distributing data collection 

requests and assessing the results).

State, local and tribal agencies could also benefit from 

more streamlined and accurate review of electronic data 

submitted to them. The ERT would allow for an electronic review 

process rather than a manual data assessment making review and 

evaluation of the source provided data and calculations easier 

and more efficient. Finally, another benefit of the proposed 

data submittal to WebFIRE electronically is that these data 

would greatly improve the overall quality of existing and new 

emissions factors by supplementing the pool of emissions test 

data for establishing emissions factors and by ensuring that the 

factors are more representative of current industry operational 
Page 112 of 236

procedures. A common complaint heard from industry and 

regulators is that emissions factors are outdated or not 

representative of a particular source category. With timely 

receipt and incorporation of data from most performance tests, 

the EPA would be able to ensure that emissions factors, when 

updated, represent the most current range of operational 

practices. In summary, in addition to supporting regulation 

development, control strategy development and other air 

pollution control activities, having an electronic database 

populated with performance test data would save industry, state, 

local, tribal agencies and the EPA significant time, money and 

effort while also improving the quality of emissions inventories 

and, as a result, air quality regulations.

3. ACGIH Guidelines

Capture and Collection Requirements 

Subpart RRR specifies the ACGIH Industrial Ventilation 

Manual as the standard for acceptable capture and collection of 

emissions from a source with an add-on air pollution control 

device. See §63.1506(c)(1) and Table 3 to subpart RRR. The rule 

currently incorporates by reference “Chapters 3 and 5 of 

Industrial Ventilation: A Manual of Recommended Practice”, 

American Conference of Government Industrial Hygienists (ACGIH), 

23rd edition, 1998. Two issues have been raised with respect to 

the ACGIH Guidelines since inception of the rule.
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First the referenced version of the manual is no longer in 

print. Therefore we are proposing that the 23rd edition or the 

most recent 27th edition to the manual may be used. Further we 

are proposing to remove the specific chapter reference due to 

difference in the manual versions.

Second, the current rule requires that emissions capture 

and collection systems be designed consistent with the ACGIH 

industrial ventilation guidelines and that the methodologies of 

demonstrating compliance with capture and collection are 

consistent with ACGIH requirements. We are proposing that 

affected sources that are equipped with air pollution control 

devices must follow the ACGIH Guidelines, 23rd or 27th editions. 

Industry representatives point out that the manual contains 

“recommended” ventilation practices and assert that subpart RRR 

inappropriately requires compliance with the guidelines. For 

example, the guidance establishes design criteria for 

determining minimum hood dimensions and flow; however, industry 

representatives allege that the relevant equation is not 

appropriate for determining minimum flow requirements for 

“oversized” hoods that are used in the secondary aluminum 

production industry. The equations for sizing hoods in Chapter 3 

of the 23rd edition were said to over-predict the required flow 

rates. According to industry representatives, the ACGIH manual 

should be used only as a guideline for judging the effectiveness 
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of the hoods and that engineering evaluations of hoods can be 

performed similarly to those for other engineered processes. 

Also, there may be rules and ventilation guidelines developed by 

other professional organizations, governmental agencies or 

industry organizations that are appropriate and could be used.

Therefore, we are considering allowing other recognized 

design criteria and methodologies for the capture and collection 

of emissions in the demonstration of compliance, which will 

provide more flexibility to the industry. We are inviting 

comments on alternatives to the ACGIH guidelines or other 

suggestions for revising the rule to increase flexibility for 

the industry while ensuring that capture and collection systems 

are adequately designed and operated to insure that emissions 

are captured and fugitive emissions minimized. In particular, we 

would be interested in obtaining information on minimum face 

velocity, elimination of visible emissions, minimum pressure 

drop or other suitable parameter(s) to determine capture 

effectiveness.

4. Scrap Inspection Program for Group 1 Furnace without Add-on 

Air Pollution Control Device

Under the current subpart RRR NESHAP, the owner or operator 

of a group 1 furnace that is not equipped with an add-on air 

pollution control device must prepare a written monitoring plan 

describing the measures that will be taken to ensure continuous 
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compliance with all applicable emissions limits. One such 

measure is the inspection of scrap to determine the levels of 

contaminants in the scrap that will be charged to the furnace. 

Section 63.1510(p) lists the requirements for a scrap inspection 

program although this scrap inspection program is not mandatory. 

Because the Agency considers a well designed and implemented 

scrap inspection program important to ensuring that emissions 

are maintained at levels below the applicable emissions limits, 

we are interested in how we could improve the current scrap 

inspection provisions as well as how we would make the scrap 

inspection program more usable. Therefore, we are soliciting 

comments and information on what such a program should include. 

We are particularly interested in receiving comments and 

information from companies, organizations or individuals that

may have experience with scrap inspection programs and may have 

been involved in developing and implementing such programs.

5. Multiple Tests for Worst Case Scenarios

The existing rule currently allows testing to demonstrate 

compliance under a range of operating scenarios. Facilities that 

process a range of materials (such as dross, used beverage 

containers (UBC), etc.) may have different scenarios (production 

levels, range of charge materials, and reactive fluxing rates) 

that result in a range of emissions for the different regulated 

pollutants. For example, the scenario resulting in the highest 
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emissions of HCl may be while processing dross; the scenario 

resulting in the highest emissions of D/F formation may be while

processing UBC; and the scenario resulting in the highest 

emissions of PM is most likely UBC as well. The EPA is aware of 

concerns that under the original rule and subsequent amendments, 

there may be some uncertainty about different testing conditions 

that may be required for different HAP. We are proposing 

amendments to §63.1511 to clarify that performance tests under 

multiple scenarios may be required in order to reflect the 

emissions ranges for each regulated pollutant.

6. Lime Injection Rate Verification

The rule currently requires owners/operators to verify that 

continuous lime injection system maintains free-flowing lime in 

the hopper at all times and maintain the lime feeder setting at 

the same level established during the performance test. However 

the rule does not specifically require that the feeder setting 

be verified with a pound per hour (lb/hr) injection rate as 

established in the performance test. Due to continuous usage of 

the equipment, the feeder setting and injection rate may not 

correlate as they did during the performance test. Periodic 

verification of the actual injection rate in pounds per hour 

would ensure that the necessary amount of lime is reaching the 

baghouse and it would give a better indication of continuous 

compliance. We are proposing to revise §63.1510 by adding a 
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requirement for the verification of the lime injection rate in 

pounds per hour at least once per month. We are also proposing 

changes to clarify that for the purposes of monitoring the rate 

of lime injection, the lime injection feeder setting must be set 

no lower than that determined in the performance test; however, 

it may be set above that level.

7. Flux Monitoring

Flux monitoring provisions in §63.1510(j)(3)(ii) require 

the owner/operator to record, for each 15-minute block period 

during each operating cycle or time period used in the 

performance test during which reactive fluxing occurs, the time, 

weight and type of flux for each addition of solid reactive 

flux. Solid flux, however, may be added intermittently during 

the operating cycle dependent upon the needs of the furnace. We 

are proposing amendments to revise these monitoring requirements 

to clarify that solid flux should be tracked at each addition 

during the cycle or time period used in the performance test.

8. Cover Fluxes

Cover flux is defined in §63.1503 as “salt added to the 

surface of molten aluminum in a group 1 or group 2 furnace, 

without agitation of the molten aluminum for the purpose of 

preventing oxidation”. We have received information from 

industry and state agencies indicating that most furnaces are 

agitated. Rotary furnaces are constantly rotated until the metal 
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is tapped and reverberatory furnaces have a molten metal pump 

circulating aluminum from the hearth to the charge well 

providing agitation to melt the scrap. In order to avoid major 

source status, a few secondary aluminum facilities have claimed 

that they were using cover fluxes when they were actually using 

reactive fluxes which may lead to higher emissions. Other 

sources claiming to use a cover flux were using them in furnaces 

in which the melt was being agitated and, therefore, did not 

meet the definition of cover flux. To address this, we are 

proposing to clarify the definition of cover flux by adding to 

the definition the following: Any flux added to a rotary furnace 

or other furnace that uses a molten metal pump or other device 

to circulate the aluminum is not a cover flux. Any reactive flux 

cannot be a cover flux.

9. Capture and Collection System

Affected sources under the current rule that are controlled 

by an air pollution control device must use a capture and 

collection system meeting the guidelines of the ACGIH in order 

to minimize fugitive emissions and ensure that emissions are 

routed to the control device where the pollutants are removed 

from the exhaust gas stream. As part of efforts to clarify 

hooding and capture requirements we are proposing a definition 

for capture and collection systems, as follows: Capture and 

collection system means the system of hood(s), duct system and 
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fan used to collect a contaminant at or near its source, and for 

affected sources equipped with an air pollution control device,

transport the contaminated air to the air cleaning device.

10. Bale Breakers and Scrap Shredders

The current regulation exempts bale breakers from the 

requirements for aluminum scrap shredders and the definition of

shredders is intentionally broad. To clarify that a bale breaker 

is not a scrap shredder, we are proposing a definition for bale 

breaker. We are also proposing to clarify in the definition of 

aluminum scrap shredder that both high speed and low speed 

shredding devices are considered scrap shredders.

11. Bag Leak Detection Systems (BLDS)

The current requirements for BLDS in the rule cite a 1997 

guidance document on bag leak detection systems that operate on 

the triboelectric effect (when materials become electrically 

charged through contact and separation from another material).

BLDS currently in use operate digitally and are not addressed by 

the 1997 guidance. We are proposing to update §63.1510(f) to 

remove the reference to the 1997 guidance document and require 

that the manufacturer’s maintenance and operating instructions 

be followed at all times.

12. Sidewell Furnaces

The monitoring requirements for sidewell group 1 furnaces 

with uncontrolled hearths specify recording the level of molten 
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metal (above or below the arch between the sidewell and hearth) 

for each charge to the furnace. Because there are emission units 

that add charge continuously and emission units that add charge 

intermittently, the requirements to record levels during each 

charge can be problematic for some sources. Also, the only 

option for verifying the molten level is visual observation 

which may be difficult in some cases. To address these issues, 

we are proposing revisions to §63.1510(n) to require the 

monitoring to be done after each tap, rather than each charge. 

We are also proposing that where visual inspection of the molten 

metal level is not possible, physical measurement to determine 

the molten metal level in sidewell group 1 furnaces will be 

required. We are also proposing to add a definition of tap to 

mean the end of an operating cycle when processed molten 

aluminum is poured from a furnace.

13. Testing Representative Units

Section §63.1511 allows testing of a representative 

uncontrolled Group 1 furnace or in-line fluxer to determine the 

emission rate of other similar units. Some secondary aluminum 

facilities have conducted one test run on each of multiple 

emission units to comprise one test, rather than performing all 

test runs on the same unit. This is not the intent of the rule. 

We are proposing to amend §63.1511(f) to clarify that the three 

test runs must be conducted on the same unit.
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14. Initial Performance Tests

Section 63.1511(b) of the current rule requires a new 

source (i.e., a source that commences construction after 1999)

to conduct its initial performance tests for a new or modified 

source within 90 days of start-up to show compliance with 

emission limits and to establish its operating parameters. Other

MACT standards provide sources 180 days in which to conduct

their initial performance test. The General Provisions in §63.7 

set this time limit at 180 days. Because a period of 180 days to 

conduct testing would help the secondary aluminum industry avoid 

the cost of unnecessary repeat testing and it is consistent with 

the General Provisions, we are proposing to revise §63.1511 to 

allow 180 days to conduct an initial performance test.

15. Definitions of Scrap Dryer/Delacquering Kiln/Decoating Kiln 

and Aluminum Scrap Shredder

We are proposing revisions to the definition of scrap 

dryer/delacquering kiln/decoating kiln to clarify that thermal 

delaminating of aluminum scrap and mechanical granulation of the 

recovered metal are affected sources under Subpart RRR. Heat is 

used to separate foil from paper and plastic in scrap. These

sources operate chambers with a maximum temperature of 900

degrees Fahrenheit and with no melting of the recovered 

aluminum. Under the proposed definition, subsequent melting of 

recovered aluminum need not occur at the same facility that 
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conducts the recovery operation. We are also proposing to amend 

the definition of a scrap shredder to include granulation and 

shearing in addition to crushing, grinding, and breaking of

aluminum scrap into a more uniform size prior to processing or 

charging to a scrap dryer/delacquering kiln/decoating kiln or 

furnace.

16. Transporting Metal

We are addressing questions as to the applicability of the 

rule to pots that are used to transport metal to customers. The 

rule does not currently regulate these pots and we are proposing 

to amend the definition of Group 2 furnace to clarify the fact 

that the rule does not regulate these pots.

17. Specifications for Cleaning Processes

We considered whether to add specifications for cleaning 

processes such as those required for runaround scrap to ensure 

that scrap processed by certain methods qualifies as clean 

scrap. Specifications considered include minimum residence time 

and temperature for thermal drying process and minimum speed and 

residence time for centrifuging processes. We are not proposing 

these revisions in today’s action. However, we invite comments

on this issue and solicit information on appropriate 

specifications that could be applied to these processes to 

ensure that the cleaning process produces clean charge.

18. HF Emissions Compliance Provisions
Page 123 of 236

The current subpart RRR standards applicable to major 

sources contain limits for HCl emissions from group 1 furnaces 

and require operators to conduct performance tests for HCl 

emissions. The EPA stated in the subpart RRR NESHAP that HCl 

would serve as a surrogate for all acid gases, including HF. 

Where chlorine-containing fluxes were used along with fluorinecontaining fluxes, lime-injected fabric filters would 

effectively control HCl and HF so that determining compliance 

with the HCl limit was considered sufficient, and a separate 

compliance measure for HF was not required.

In this rulemaking, we are proposing to modify the 

compliance provisions in subpart RRR to ensure that HF emissions 

from group 1 furnaces without add-on control devices are 

addressed consistent with the intent of the promulgated 

standards. Specifically, a secondary aluminum facility with an 

uncontrolled Group 1 furnace may use fluorine-containing fluxes 

without using chlorine-containing fluxes, and would not be 

required under the current rule to test the furnace for HF, so 

any HF emissions would be neither controlled nor accounted for 

in any HCl testing. 

We are proposing to require owners and operators of 

uncontrolled group 1 furnaces to test for both HF and HCl. We 

are proposing that the limits for HF from these furnaces would 

be 0.4 lb/ton of feed, equivalent to the existing subpart RRR 
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limits for HCl from Group 1 furnaces. Our reasoning is that 

secondary aluminum facilities use chlorine-containing and 

fluorine-containing fluxes to perform the same function of 

enabling the removal of impurities (such as magnesium) from 

aluminum. They are also chemically similar, in that both are 

halogens. Therefore, if an uncontrolled Group 1 furnace has a 

given mass of impurities to be removed from the aluminum, the 

owner/operator may either use a chlorine-containing or fluorinecontaining flux, and based on the information currently 

available to EPA, we propose that uncontrolled Group 1 furnaces 

be subject to testing for HF and an associated HF emission limit 

that is the same as the currently applicable HCl emission limit. 

We are proposing that EPA Method 26A be used, which is capable 

of measuring HCl and HF. The testing requirement for HF would 

coincide with HCl testing at the next scheduled performance test 

after the effective date of the final rule. As an alternative to 

testing for HF, we are proposing that the owner or operator may 

choose to determine the rate of reactive flux addition for an 

affected source, and may assume that, for the purposes of 

demonstrating compliance with the SAPU emission limit, all 

fluorine in the reactive fluxes added to the source are emitted 

as HCl or HF. This alternative is already available for 

operators using chlorine-containing reactive fluxes. 
Page 125 of 236

Based on information received from industry, we estimate 

that approximately 199 group 1 furnaces at approximately 29 

secondary aluminum production facilities are uncontrolled. These 

furnaces are already required to be tested to determine HCl 

emissions at least once every five years. Therefore, the only 

additional costs for these sources would be the laboratory 

analysis for HF. We estimate these costs to be approximately 

$1,000 per test. We expect that only furnaces that use fluorinecontaining fluxes would potentially test for HF. Approximately 

55 furnaces at eight facilities use fluorine-containing fluxes. 

Therefore, the total cost of this proposed rule revision is 

approximately $55,000 every 5 years, or approximately $11,000 

per year. More information is available in the Cost Estimates

for 2012 Proposed Rule Changes to Secondary Aluminum NESHAP

which is available in the docket for this proposed rule.

19. Requirements for Uncontrolled Furnaces that Do Not Presently 

Comply with ACGIH Ventilation Guidelines

Section 63.1506(c)(1) requires that, for each affected 

source or emission unit equipped with an add-on air pollution 

control device, the owner or operator must design and install a 

system for the capture and collection of emissions to meet the 

engineering standards for minimum exhaust rates as published by 

the ACGIH in chapters 3 and 5 of “Industrial Ventilation: A 

Manual of Recommended Practice.” However, there are no similar 
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requirements for furnaces that are not equipped with an add-on 

air pollution control device. Furnaces that are uncontrolled for 

fugitive emissions do not account for fugitive emissions that 

escape during testing for example through open doors and 

therefore underestimate emissions during performance testing.

Accordingly, we are proposing that owner/operators with 

uncontrolled affected sources either: (1) construct hooding for 

testing that meets the ACGIH guidelines, and include emissions 

captured by that hooding in the compliance determination, or (2) 

assume a capture efficiency of 66.67 percent (i.e., multiply 

stack test results by a factor of 1.5) to account for emissions 

not captured. The basis for this proposed requirement is further 

discussed in the Draft Technical Support Document for the 

Secondary Aluminum Production Source Category included in the 

docket for this rule. If the source fails to demonstrate 

compliance using the 66.67 percent capture efficiency approach, 

we are proposing that the owner/operator retest with hoods 

meeting the ACGIH guidelines within 180 days. These proposed 

requirements would be implemented at the next scheduled 

performance test after the effective date of the final rule. We

recognize that there may be situations (e.g., various furnace 

configurations) where constructing hooding may be problematic. 

Therefore, we are seeking comments and information on these 

proposed requirements and regarding other possible approaches 
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that could be applied, such as emissions monitoring to address 

these unmeasured fugitive emissions. We also seek comments and 

information on work practices that could be applied during 

compliance testing that would minimize the escape of these

fugitive emissions, including approaches that could be adapted 

for different furnace configurations, and to ensure that the 

vast majority of emissions from these units are accounted for 

during compliance testing.

We estimate that there are 107 uncontrolled furnaces that 

would be required to either install hooding that meets ACGIH 

guidelines for testing or to assume the 66.67 percent capture 

efficiency. We estimate that the capital cost of constructing 

the appropriate hooding would be $57,000 per affected furnace, 

resulting in a total capital cost of up to $6,099,000 for the 

source category (conservatively assuming that all these furnaces 

choose the hooding option), and an annualized cost of up to 

$1,220,000 (again based on the conservative assumption that all 

facilities choose the option of constructing hooding). 

20. Clarify the Possible Number of New SAPUs

The rule currently states that there can be only one 

existing SAPU at an aluminum plant but is not clear on whether 

there can be more than one new SAPU. We are proposing revisions 

to clarify that more than one new SAPU is allowed under the 

rule.
Page 128 of 236

21. Aluminum Scrap Containing Anodizing Dyes or Sealants

The current definition of “clean charge” does not clearly 

indicate the status of anodized aluminum. Some anodized aluminum 

parts contain dyes and/or sealants that contain organic 

materials. Therefore, we propose to amend the definition of 

“clean charge” to indicate that clean charge does not include 

anodized material that contains dyes or sealants that contain 

organic material.

22. Afterburner Residence Time

Currently, the standard contains the following definition: 

“Residence time means, for an afterburner, the duration of time 

required for gases to pass through the afterburner combustion 

zone. Residence time is calculated by dividing the afterburner 

combustion zone volume in cubic feet by the volumetric flow rate 

of the gas stream in actual cubic feet per second.”

At some secondary aluminum facilities, the ductwork has 

been included as part of the combustion chamber to increase the 

calculated residence time and meet the requirements to qualify 

for alternative limits in §63.1505(e). While this interpretation 

may not be consistent with the current definition, it can be 

shown that in some afterburners, the temperature in the duct 

work is adequate for D/F destruction, which would justify the 

inclusion of the duct work in the calculation of residence time. 
Page 129 of 236

We found that the basis for the residence time requirements 

for sweat furnaces and delacquering kilns in §63.1505 did 

include the refractory lined duct up to the thermocouple 

measurement location. Therefore, we are proposing to amend the 

definition of residence time as follows, “Residence time means, 

for an afterburner, the duration of time required for gases to 

pass through the afterburner combustion zone. Residence time is 

calculated by dividing the afterburner combustion zone volume in 

cubic feet by the volumetric flow rate of the gas stream in 

actual cubic feet per second. The combustion zone volume 

includes the reaction chamber of the afterburner in which the 

waste gas stream is exposed to the direct combustion flame and 

the complete refractory lined portion of the furnace stack up to 

the measurement thermocouple.”

23. SAPU Feed/Charge Rate

There has been confusion over the interpretation of certain

SAPU requirements such that a SAPU emission limit should be 

calculated based on feed/charge rates during performance test.

Our interpretation has always been that allowable emissions are 

calculated on a daily basis using feed/charge throughput, which 

can change daily. Because of the confusion over the appropriate 

method, we are proposing clarifications that will make it clear 

that the daily throughput, and not the throughput at the time of 

the performance test, is used in the calculation of allowable 
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emissions in each emissions unit (group 1 furnace or in-line

fluxer) within the SAPU. Consistent with the existing rule, area 

sources of HAP would not be required to calculate, or comply with 

a SAPU emission limit for PM or HCl. The owner or operator would 

be required to demonstrate compliance with these limits and these 

calculated SAPU emission limits would be used to establish 

compliance in accordance with the procedures in §63.1513. 

24. Changing Furnace Classification

The current subpart RRR regulatory text does not explicitly

address whether and under what conditions a secondary aluminum 

production furnace may change its classification between group 1 

furnace with add-on air pollution control device (APCD) (i.e., 

group 1 controlled furnace), group 1 furnace without add-on APCD 

(i.e., group 1 uncontrolled furnace), and group 2 furnace. This 

has led to uncertainty for facilities when considering available 

compliance options. The EPA proposes a new section 63.1514 that 

would allow an owner/operator to change a furnace’s 

classification (also called an operating mode), as long as the 

change and new operating mode are fully compliant with all

substantive and procedural requirements of the subpart RRR. The 

proposed procedures include limits on the frequency with which 

furnace operating modes can be changed. Practical implementation 

and enforcement of requirements such as SAPU compliance, 

Operation, Maintenance and Monitoring (OM&M) plans, and labeling 
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require that furnace operating modes are not in a state of 

constant change. Therefore, we are proposing that a change in 

furnace operating mode and reversion to the previous operating

mode occurs no more frequently than once every 6 months, with an 

exception for control device maintenance requiring shutdown. 

Furnaces equipped with APCDs that meet the requirements for 

changing furnace classifications would be permitted to change 

operating mode and revert to the previous operating mode without 

restriction on frequency in cases where an APCD was shut down 

for planned maintenance activities such as bag replacement.

These proposed revisions specify the emissions testing that 

would be required to change furnace operating modes; operating 

requirements, such as labeling, flux use, scrap charging for the 

furnace before, during, and after changing; and recordkeeping

requirements. These proposed revisions will provide industry 

with the flexibility to efficiently operate furnaces in response 

to changes in the availability of feed materials and other 

operational conditions. While providing increased flexibility, 

it is also important that EPA maintain its compliance oversight 

of these affected sources to ensure furnace operations are 

compliant with the rule. Therefore, EPA is proposing certain 

limitations on how and when furnaces can change from one 

operating mode to another. For example, when a furnace is 

changed from a group 1 furnace to a group 2 furnace, we are 
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proposing that performance testing be conducted when the furnace 

is changed to the group 2 mode to verify that the furnace is not 

emitting HAP at levels above the relevant limits as a result of 

any HAP-containing feed or flux left in the furnace. We are also 

proposing requirements for this scenario to confirm that HAP 

emissions are sufficiently low to ensure that the furnace, while 

operating as a group 2 furnace, is performing as a group 2 

furnace, that is, with little or no HAP emissions. To ensure 

that furnaces have had sufficient throughput (or time) in their 

new operating mode such that performance tests are 

representative of their new operating mode, the proposed 

amendments would require waiting periods of one or more chargeto-tap cycles or 24 operating hours before conducting 

performance testing. For alternate operating modes we are 

proposing that the testing be required in order to demonstrate 

that the furnace remains compliant with all applicable emission 

limits. Major sources would be required to repeat the required 

tests at least once every 5 years. When following the 

substantive and procedural requirements of this rule, some

owners/operators may be able to turn off associated air 

pollution control devices. Because of this increased 

flexibility, we estimate an annual savings of $1,100,000, based 

on an estimate of controls for 50 furnaces being turned off for 

6 months per year. We estimate additional testing costs of 
Page 133 of 236

$500,000 per year. Therefore, we estimate the net cost to be 

negative $600,000 per year (a savings of $600,000 per year). We 

solicit comment on our estimates of avoided costs and testing 

costs.

25. Dross Only Versus Dross/Scrap Furnaces

Dross only furnaces at area sources are not subject to 

subpart RRR D/F emission limitations and therefore are not 

subject to the MACT operating parameter limitations. Industry 

representatives have inquired about the requirements for a 

furnace processing scrap on some occasions and then dross at 

other times.

We note that dross only furnaces are defined as furnaces 

that only process dross. A furnace that processes scrap may be a 

group 1 furnace or a group 2 furnace. Operators of group 1 

furnaces have the option of conducting performance tests under 

different operating conditions to establish operating parameters 

applicable to different combinations of types of charge and 

fluxing rates. We have added language to clarify this in the 

proposed amendments. We note that dross is not clean charge, as 

defined in the rule, and thus any group 1 furnace processing 

dross is subject to limitations on emissions of D/F, and other 

requirements for group 1 furnaces processing other than clean 

charge.

26. Annual Hood Inspections
Page 134 of 236

Industry representatives have stated that our 

interpretation that annual hood inspections include an annual 

hood flow measurement represents an unnecessary cost burden for 

each regulated facility. Industry representatives recommended 

that flow testing should only be required after modifications to 

the hood, furnace, and/or controls that could negatively impact 

the capture and, only then if they cannot be demonstrated by 

alternate engineering calculations or operating parameters. They 

contend that due to stringent OM&M protocols, it should be 

sufficient to certify that there have been no changes, with 

possible verification of flow by visual inspections of hoods and 

ductwork for leaks and possible verification of fan amperage. We 

disagree that these measures alone are sufficient to verify that 

flow is sufficient and that annual hood flow measurement 

represents an unnecessary cost burden. We are proposing to 

codify in the rule our existing interpretation that annual hood 

inspections include flow rate measurements. These flow rate 

measurements supplement the effectiveness of the required visual 

inspection for leaks (which may be difficult or uncertain for 

certain sections of ductwork), to reveal the presence of 

obstructions in the ductwork, confirm that fan efficiency has 

not declined, and provide a measured value for air flow.

27. Applicability of Rule to Area Sources
Page 135 of 236

While the emissions standards that apply to area sources 

are evident in the current rule, the applicable operating, 

monitoring, and recordkeeping and reporting requirements are 

less clear. In general, the intent of the rule is to subject 

area sources to standards for D/F with corresponding monitoring, 

testing, reporting, and recordkeeping. We are proposing 

amendments that would clarify which of the operating, monitoring 

and other requirements apply to area sources. 

28. Altering Parameters during Testing with New Sources of Scrap

Currently, the rule requires that when a process parameter 

or add-on air pollution control device operating parameter 

deviates from the value or range established during a 

performance test, the owner or operator must initiate corrective 

action. However, when the owner or operator is conducting 

performance testing with a new type of scrap, it may be 

necessary to deviate from the previously established values. The 

rule was not intended to prevent owners/operators from 

establishing new or revised operating parameters, if necessary 

to process different types of scrap. Accordingly, we are 

modifying the rule to allow deviations from the values and 

ranges in the OM&M plan during performance testing only, 

provided that the site-specific test plan documents the intent 

to establish new or revised parametric limits. 

29. Controlled Furnaces that are Temporarily Idled
Page 136 of 236

Currently, the rule does not specify if an owner or 

operator may discontinue the operation of its control device if 

a furnace is not in use, but is not completely empty or shut 

down. Industry has requested that the EPA provide allowances for 

control devices to be turned off while the furnaces are not in 

operation or being charged with aluminum scrap or fluxing 

agents. This typically occurs over the weekend and accounts for 

unnecessary electrical and operating costs. Accordingly, we are 

modifying the rule to allow for the discontinued use of control 

devices for these furnaces that will remain idle for 24 hours or 

longer.

30. Annual Compliance Certification for Area Sources

Because area sources that are subject to subpart RRR are 

exempt from the obligation to obtain a permit under 40 CFR part 

70 or 71, it was not clear how area sources certified their 

annual compliance. To clarify that area sources are required to 

certify their annual compliance, we are proposing clarifying 

language to §63.1516(c).

E. Compliance dates

We are proposing that existing facilities must comply with 

all changes proposed in this action 90 days after promulgation 

of the final rule. All new or reconstructed facilities must 

comply with all requirements in the final rule upon startup.

V. Summary of Cost, Environmental, and Economic Impacts
Page 137 of 236

A. What are the affected sources?

We estimate that there are 161 secondary aluminum 

production facilities that will be affected by this proposed 

rule, of which 53 are major sources of HAPs, and 108 are area 

sources. We estimate that 10 secondary aluminum facilities have 

co-located primary aluminum operations. The affected sources at 

secondary aluminum production facilities include new and 

existing scrap shredders, thermal chip dryers, scrap 

dryer/delacquering kiln/decoating kilns, group 2 furnaces, sweat 

furnaces, dross-only furnaces, rotary dross cooler and secondary 

aluminum processing units containing group 1 furnaces and inline fluxers.

B. What are the air quality impacts?

No reductions are being proposed to numerical emissions 

limits. The proposed amendments include requirements that 

affected sources comply with the numerical emissions limits at 

all times including periods of startup and shutdown to help

ensure that emissions from those affected sources are minimized. 

The proposed amendments would help to clarify the existing 

provisions and would help to improve compliance. The proposed 

amendment to limit and require testing of HF emissions for 

uncontrolled group 1 furnaces is not expected to significantly 

reduce HF emissions but will help to ensure that HF emissions 

remain low. We believe that the proposed revisions would result 
Page 138 of 236

in little or no emissions reductions. Therefore, no air quality 

impacts are expected.

C. What are the cost impacts?

We estimate the total cost of the proposed amendments to be 

up to approximately $611,000 per year. We estimate that 56 

unique facilities are affected and that the cost per facility 

ranges from negative $36,000 per year for a facility changing 

furnace operating modes to $112,000 per year for a facility 

installing hooding for testing. Our estimate includes an 

annualized cost of up to $1,200,000 for installing uncontrolled 

furnace testing hooding that meets ACGIH requirements, assuming 

that 107 furnaces choose that option (rather than assuming a 67 

percent capture efficiency for their existing furnace exhaust 

system). Our estimate also includes an annualized cost of 

$11,000 for testing for HF on uncontrolled furnaces that are 

already testing for HCl. Finally, we estimate cost savings of 

$600,000 per year for furnaces that change furnace operating 

modes and turn off their control devices. Our estimate is based 

on 50 furnaces turning off their controls for approximately 6 

months every year. This savings is net of the cost of testing to 

demonstrate that these furnaces remain in compliance with 

emission limits after their control devices have been turned 

off. The estimated costs are explained further in the Cost 
Page 139 of 236

Estimates for 2012 Proposed Rule Changes to Secondary Aluminum 

NESHAP, which is available in the docket.

D. What are the economic impacts?

We performed an economic impact analysis for the proposed

modifications in this rulemaking. That analysis estimates total 

annualized costs of approximately $0.6 million at 28 facilities 

and cost to sales ratios of less than 0.02 percent for the 

Secondary Aluminum Production source category. For more 

information, please refer to the Economic Impact Analysis for 

the Proposed Secondary Aluminum NESHAP that is available in the 

public docket for this proposed rulemaking.

E. What are the benefits?

We do not anticipate any significant reductions in HAP 

emissions as a result from these proposed amendments. However, 

we think that the proposed amendments would help to improve the 

clarity of the rule, which can help to improve compliance and 

help to ensure that emissions are kept to a minimum. Certain 

provisions may also provide operational flexibility to the 

industry at no increase in HAP emissions.

VI. Request for Comments

We are soliciting comments on all aspects of this proposed 

action. In addition to general comments on this proposed action, 

we are also interested in any additional data that may help to 

reduce the uncertainties inherent in the risk assessments and 
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other analyses. We are specifically interested in receiving 

corrections to the site-specific emissions profiles used for 

risk modeling. Such data should include supporting documentation 

in sufficient detail to allow characterization of the quality 

and representativeness of the data or information. Section VII 

of this preamble provides more information on submitting data.

VII. Submitting Data Corrections

The site-specific emissions profiles used in the source 

category risk 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 that 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
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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

Delete Comment Describes the reason for deletion

Emissions Calculation Method 

Code For Revised Emissions

Code description of the method 

used to derive emissions. For 

example, CEM, material balance, 

stack test, etc.

Emissions Process Group

Enter the general type of 

emissions process associated with 

the specified emissions 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 Emissions Release 

Point Type

Enter revised Emissions Release 

Point Type here

REVISED End Date Enter revised End Date here

REVISED Exit Gas Flow Rate Enter revised Exit Gas Flow Rate 

here (ft3/sec)
Page 142 of 236

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 

emissions 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)

Year Closed Enter date facility stopped 

operations

2. Fill in the commenter information fields for each 

suggested revision (i.e., commenter name, commenter 
Page 143 of 236

organization, commenter email address, commenter phone number, 

and revision comments).

3. Gather documentation for any suggested emissions 

revisions (e.g., performance test reports, material balance 

calculations).

4. Send the entire downloaded file with suggested revisions 

in Microsoft® Access format and all accompanying documentation 

to Docket ID Number EPA-HQ-OAR-2010-0544 (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 RTR 

Web Page at: http://www.epa.gov/ttn/atw/rrisk/rtrpg.html.

VIII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and 

Executive Order 13563: Improving Regulation and Regulatory 

Review.

Under Executive Order 12866 (58 FR 51735, October 4, 1993), 

this action is a significant regulatory action because it raises 
Page 144 of 236

novel legal and policy issues. Accordingly, the EPA submitted 

this action to the Office of Management and Budget (OMB) for 

review under Executive Orders 12866 and 13563 (76 FR 3821, 

January 21, 2011) 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 the EPA has been assigned the EPA ICR number 

2453.01. The information collection requirements are not 

enforceable until OMB approves them. The information 

requirements are based on notification, recordkeeping, and 

reporting requirements in the NESHAP General Provisions (40 CFR 

part 63, subpart A), which are mandatory for all operators 

subject to national emissions standards. These recordkeeping and 

reporting requirements are specifically authorized by CAA 

section 114 (42 U.S.C. 7414). All information submitted to the 

EPA pursuant to the recordkeeping and reporting requirements for 

which a claim of confidentiality is made is safeguarded 

according to agency policies set forth in 40 CFR part 2, subpart 

B.
Page 145 of 236

We are proposing new paperwork requirements to the 

Secondary Aluminum Production source category in the form of 

reporting for furnace changes in classification and affirmative 

defense and recordkeeping with regard to verification of lime 

injection rates and change in furnace classifications. New 

monitoring requirements under the proposed revisions include 

testing for HF, and testing related to furnace classification 

changes.

For this proposed rule, the EPA is adding affirmative 

defense to the estimate of burden in the ICR. To provide the 

public with an estimate of the relative magnitude of the burden 

associated with an assertion of the affirmative defense position 

adopted by a source, the EPA has provided administrative 

adjustments to this ICR to show what the notification, 

recordkeeping and reporting requirements associated with the 

assertion of the affirmative defense might entail. The EPA’s 

estimate for the required notification, reports and records for 

any individual incident, including the root cause analysis, 

totals $3,142 and is based on the time and effort required of a 

source to review relevant data, interview plant employees, and 

document the events surrounding a malfunction that has caused a 

violation of an emissions limit. The estimate also includes time 

to produce and retain the record and reports for submission to 

the EPA. The EPA provides this illustrative estimate of this 
Page 146 of 236

burden because these costs are only incurred if there has been a 

violation and a source chooses to take advantage of the 

affirmative defense.

Given the variety of circumstances under which malfunctions 

could occur, as well as differences among sources' operation and 

maintenance practices, we cannot reliably predict the severity 

and frequency of malfunction-related excess emissions events for 

a particular source. It is important to note that the EPA has no 

basis currently for estimating the number of malfunctions that 

would qualify for an affirmative defense. Current historical 

records would be an inappropriate basis, as source owners or 

operators previously operated their facilities in recognition 

that they were exempt from the requirement to comply with 

emissions standards during malfunctions. Of the number of excess 

emissions events reported by source operators, only a small 

number would be expected to result from a malfunction (based on 

the definition above), and only a subset of excess emissions 

caused by malfunctions would result in the source choosing to 

assert the affirmative defense. Thus we believe the number of 

instances in which source operators might be expected to avail 

themselves of the affirmative defense will be extremely small. 

With respect to the Secondary Aluminum Production source 

category, we estimate the annual recordkeeping and reporting 
Page 147 of 236

burden after the effective date of the proposed rule for 

affirmative defense to be 30 hours at a cost of $3,142.

We expect to gather information on such events in the 

future and will revise this estimate as better information 

becomes available. We estimate 161 regulated entities are 

currently subject to subpart RRR. The annual monitoring, 

reporting and recordkeeping burden for this collection (averaged 

over the first 3 years after the effective date of the 

standards) for these amendments to subpart RRR is estimated to 

be $1,876,521 per year. This includes 1,725 labor hours per year 

at a total labor cost of $165,521 per year, and total non-labor 

capital and operation and maintenance (O&M) costs of $1,711,000

per year. The total burden for the Federal government (averaged 

over the first 3 years after the effective date of the standard) 

is estimated to be 271 labor hours per year at an annual cost of 

$12,231. 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 the EPA's regulations in 40 CFR are listed in 40 CFR 

part 9. When these ICRs are approved by OMB, the agency will 

publish a technical amendment to 40 CFR part 9 in the Federal 

Register to display the OMB control numbers for the approved 
Page 148 of 236

information collection requirements contained in the final 

rules.

To comment on the agency's need for this information, the 

accuracy of the provided burden estimates, and any suggested 

methods for minimizing respondent burden, the EPA has 

established a public docket for this rule, which includes this 

ICR, under Docket ID number EPA-HQ-OAR-2010-0544. Submit any 

comments related to the ICR to the EPA and OMB. See the

ADDRESSES section at the beginning of this notice for where to 

submit comments to the 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 the EPA. Since OMB is required to make a 

decision concerning the ICR between 30 and 60 days after [INSERT 

THE DATE OF PUBLICATION OF THIS PROPOSED RULE IN THE FEDERAL 

REGISTER], a comment to OMB is best assured of having its full 

effect if OMB receives it by [INSERT THE DATE 30 DAYS AFTER THE 

DATE OF 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 
Page 149 of 236

Administrative Procedure Act or any other statute unless the 

agency certifies that the rule will not have a significant 

economic impact on a substantial number of small entities. Small 

entities include small businesses, small organizations, and 

small governmental jurisdictions.

For purposes of assessing the impacts of this proposed rule 

on small entities, small entity is defined as: (1) a small 

business 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-forprofit enterprise that is independently owned and operated and 

is not dominant in its field. For this source category, which 

has the NAICS code 331314, the SBA small business size standard 

is 750 employees according to the SBA small business standards 

definitions. 

After considering the economic impacts of these proposed 

changes on small entities, I certify that this action will not 

have a significant economic impact on a substantial number of 

small entities. We determined in the economic and small business 

analysis that, using the results from the cost memorandum, 28 

entities will incur costs associated with the proposed rule. Of 

these 28 entities, nine of them are small. Of these nine, all of 
Page 150 of 236

them are estimated to experience a negative cost (i.e., a cost 

savings) as a result of the rule according to our analysis. For 

more information, please refer to the Economic and Small 

Business Analysis that is in the docket.

Although this proposed rule will not have a significant 

economic impact on a substantial number of small entities, the 

EPA nonetheless has tried to reduce the impact of this rule on 

small entities. To reduce the impacts, we are correcting certain 

provisions of the rule as well as proposing revisions to help 

clarify the rule’s intent. We have also proposed new provisions 

that increase industry’s flexibility as to how they operate 

group 1 furnaces. 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 

result in expenditures of $100 million or more for State, local, 

and tribal governments, in aggregate, or the private sector in 

any 1 year. Thus, this proposed rule is not subject to the 

requirements of sections 202 or 205 of the UMRA.
Page 151 of 236

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. Thus, Executive Order 13132 

does not apply to this proposed rule.

In the spirit of Executive Order 13132, and consistent with 

the EPA policy to promote communications between the EPA and 

State and local governments, the EPA specifically solicits 

comment on this proposed rule from State and local officials.

F. Executive Order 13175: Consultation and Coordination with 

Indian Tribal Governments.

This proposed rule does not have tribal implications, as 

specified in Executive Order 13175 (65 FR 67249, November 9, 

2000). There are no secondary aluminum production facilities 
Page 152 of 236

that are owned or operated by tribal governments. Thus, 

Executive Order 13175 does not apply to this action.

The 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.

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. Moreover, the 

agency does not believe the environmental health risks or safety 

risks addressed by this action present a disproportionate risk 

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 

of energy. 

I. National Technology Transfer and Advancement Act.

Section 12(d) of the National Technology Transfer and 

Advancement Act of 1995 (“NTTAA”), Public Law No. 104-113 (15 

U.S.C. 272 note), directs the EPA to use voluntary consensus 
Page 153 of 236

standards (VCS) in its regulatory activities unless to do so 

would be inconsistent with applicable law or otherwise 

impractical. VCS are technical standards (e.g., materials 

specifications, test methods, sampling procedures, business 

practices) that are developed or adopted by voluntary consensus 

standards bodies. NTTAA directs the EPA to provide Congress, 

through OMB, explanations when the agency decides not to use 

available and applicable VCS.

This proposed rulemaking does not involve use of any new 

technical 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 

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.

The EPA has determined that this proposed rule will not 

have disproportionately high and adverse human health or 
Page 154 of 236

environmental effects on minority, low income, or indigenous 

populations because we have concluded that the existing rules 

adequately protect human health with an ample margin of safety 

and the proposed amendments do not decrease the level of 

protection provided to human health or the environment. Our 

analyses show that adverse environmental effects, human health 

multi-pathway effects and acute and chronic noncancer health 

impacts are unlikely. Our additional analysis of facilitywide 

risks for major sources showed that the maximum facilitywide 

cancer risks are within the range of acceptable risks and that 

the maximum chronic noncancer risks are unlikely to cause health 

impacts. Because our residual risk assessment determined that 

there was minimal residual risk associated with the emissions 

from facilities in this source category, a demographic risk 

analysis was not necessary for this category. 

However, the Agency reviewed this rule to determine if 

there is an overrepresentation of minority, low income, or 

indigenous populations near the sources such that they may 

currently face disproportionate risks from pollutants that could 

be mitigated by this rulemaking. This demographic distribution 

analysis only gives some indication of the prevalence of subpopulations that may be exposed to HAP pollution from the 

sources affected by this rulemaking; it does not identify the 

demographic characteristics of the most highly affected 
Page 155 of 236

individuals or communities, nor does it quantify the level of 

risk faced by those individuals or communities. 

The demographic distribution analysis shows that while most 

demographic categories are below or within 10 percent of their 

corresponding national averages, the African American percentage 

within 3 miles of any source affected by this rulemaking exceeds 

the national average by 3 percentage points (16 percent versus 

13 percent), or +23 percent. The area source sector-wide 

analysis of near source populations reveals that several 

demographic categories exceed 10 percent of their corresponding 

national averages: Minority by +16 percentage points (44% vs. 

28%), or +57%; Hispanic or Latino by +17 percentage points (34% 

vs. 17%), or +100%; Without a High School Diploma by +6 

percentage points (16% vs. 10%), or +60%, and; Below National 

Poverty Line: +7 percentage points (21% vs. 14%), or +50%. The 

facility-level demographic analysis results and the details 

concerning their development are presented in the OAQPS 

Environmental Justice Analytical Team Report, Secondary Aluminum 

– Area Sources, and OAQPS Environmental Justice Analytical Team 

Report, Secondary Aluminum – Major Sources, copies of which are 

available in the docket for this action (EPA–HQ–OAR–2010-0544).
Page 156 of 236

National Emissions Standards for Hazardous Air Pollutants: 

Secondary Aluminum Production

List of Subjects in 40 CFR Part 63

Environmental protection, Air pollution control, Hazardous 

substances, Incorporation by reference, Reporting and 

recordkeeping requirements.

____________________________

Dated:

____________________________

Lisa P. Jackson,

Administrator.
Page 157 of 236

For the reasons stated in the preamble, part 63 of title 

40, chapter I, of the Code of Federal Regulations is proposed to 

be 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 63.1501 is amended by adding paragraph (d) to read as 

follows:

§63.1501 Dates.

* * * * *

(d) The owner or operator of an existing affected source 

must comply with the following requirements of this subpart by 

[DATE 90 DAYS FROM PUBLICATION OF THE FINAL RULE IN THE FEDERAL 

REGISTER]: §63.1505(a), (i)(4), (k), (k)(1),(k)(2), (k)(3); 

§63.1506 (a)(1), (a)(5), (c)(1),(g)(5), (k)(3), (m)(4),(n)(1); 

§63.1510 (a), (b), (b)(5),(b)(9), (d)(2), (f)(1)(ii), (i)(4),

(j)(4), (n)(1), (o)(1), (o)(1)(ii), (s)(2)(iv), (t), (t)(2)(i),

(t)(2)(ii), (t)(4), (t)(5); §63.1511(a), (b), (b)(1), (b)(6),

(c)(9), (f)(6), (g)(5); §63.1512(e)(1), (e)(2),(e)(3), (e)(4),

(e)(5), (h)(1), (h)(2), (j), (j)(1)(I, (j)(2)(i), (o)(1), (p),

(p)(2); §63.1513(b), (b)(1), (e)(1), (e)(2), (e)(3); §63.1514; 

§63.1516(a), (b), (b) (1)(v), (b)(2)(iii), (b)(3), (c),(d); 

§63.1517(b)(16)(i), (b)(18), (c); §63.1520.
Page 158 of 236

* * * * *

3. Section 63.1502 is amended by revising paragraph (a)(1) and 

adding paragraph (a)(3) to read as follows:

§63.1502 Incorporation by reference.

(a) * * *

(1) “Industrial Ventilation: A Manual of Recommended 

Practice,” American Conference of Governmental Industrial 

Hygienists, (23rd edition, 1998), IBR approved for §63.1506(c), 

and

* * * * *

(3) “Industrial Ventilation: A Manual of Recommended 

Practice,” American Conference of Governmental Industrial 

Hygienists, (27rd edition, 2010), IBR approved for §63.1506(c).

* * * * *

4. Section 63.1503 is amended by:

a. Adding, in alphabetical order, new definitions of 

“affirmative defense,” “bale breaker,” “capture and collection 

system,” “HF” and “Tap”; and

b. Revising the definitions of “aluminum scrap shredder,” 

“clean charge,” “cover flux,” “Group 2 furnace,” “HCl,” 

“residence time,” “scrap dryer/delacquering kiln/decoating kiln”

and “secondary aluminum processing unit (SAPU).” 

§63.1503 Definitions.
Page 159 of 236

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.

Aluminum scrap shredder means a high speed or low speed 

unit that crushes, grinds, granulates, shears or breaks aluminum 

scrap into a more uniform size prior to processing or charging 

to a scrap dryer/delacquering kiln/decoating kiln, or furnace. A 

bale breaker is not an aluminum scrap shredder.

Bale breaker means a device used to break apart a bale of 

aluminum scrap for further processing. Bale breakers are not 

used to crush, grind, granulate, shear or break aluminum scrap 

into more uniform size pieces.

Capture and collection system means the system of hood(s), 

duct system and fan used to collect a contaminant at or near its 

source, and for affected sources equipped with an air pollution 

control device, transport the contaminated air to the air 

cleaning device.

Clean charge means furnace charge materials, including 

molten aluminum; T-bar; sow; ingot; billet; pig; alloying 

elements; aluminum scrap known by the owner or operator to be 

entirely free of paints, coatings, and lubricants; 

uncoated/unpainted aluminum chips that have been thermally dried 
Page 160 of 236

or treated by a centrifugal cleaner; aluminum scrap dried at 343 

°C (650 °F) or higher; aluminum scrap delacquered/decoated at 

482 °C (900 °F) or higher, and runaround scrap. Anodized 

aluminum that contains dyes or sealants with organic compounds 

is not clean charge.

Cover flux means salt added to the surface of molten 

aluminum in a group 1 or group 2 furnace, without agitation of 

the molten aluminum, for the purpose of preventing oxidation. 

Any flux added to a rotary furnace or other furnace that uses a 

molten metal pump or other device to circulate the aluminum is 

not a cover flux. Any reactive flux cannot be a cover flux.

Group 2 furnace means a furnace of any design that melts, 

holds, or processes only clean charge and that performs no 

fluxing or performs fluxing using only nonreactive, non-HAPcontaining/non-HAP-generating gases or agents. Pots used to 

transport metal to customers are not furnaces.

HCl means hydrogen chloride.

HF means hydrogen fluoride.

Residence time means, for an afterburner, the duration of 

time required for gases to pass through the afterburner

combustion zone. Residence time is calculated by dividing the 

afterburner combustion zone volume in cubic feet by the 

volumetric flow rate of the gas stream in actual cubic feet per 

second. The combustion zone volume includes the reaction chamber 
Page 161 of 236

of the afterburner in which the waste gas stream is exposed to 

the direct combustion flame and the complete refractory lined 

portion of the furnace stack up to the measurement thermocouple.

Scrap dryer/delacquering kiln/decoating kiln means a unit 

used primarily to remove various organic contaminants such as 

oil, paint, lacquer, ink, plastic, and/or rubber from aluminum 

scrap (including used beverage containers) prior to melting, or 

that separates aluminum foil from paper and plastic in scrap.

Secondary aluminum processing unit (SAPU). An existing SAPU 

means all existing group 1 furnaces and all existing in-line 

fluxers within a secondary aluminum production facility. Each 

existing group 1 furnace or existing in-line fluxer is 

considered an emission unit within a secondary aluminum 

processing unit. A new SAPU means any combination of individual 

group 1 furnaces and in-line fluxers within a secondary aluminum 

processing facility which either were constructed or 

reconstructed after February 11, 1999, or have been permanently 

redesignated as new emission units pursuant to §63.1505(k)(6). 

Each of the group 1 furnaces or in-line fluxers within a new 

SAPU is considered an emission unit within that secondary 

aluminum processing unit. A secondary aluminum production 

facility may have more than one new SAPU.

Tap means the end of an operating cycle when processed 

molten aluminum is poured from a furnace.
Page 162 of 236

* * * * *

5. Section 63.1505 is amended by: 

a. Revising paragraph (a);

b. Revising paragraph (i)(4); 

c. Revising paragraph (k); 

d. Revising paragraph (k)(1)

e. Revising paragraph (k)(2);and

f. Revising paragraph (k)(3) to read as follows:

§63.1505 Emission standards for affected sources and emission 

units.

(a) Summary. (1) The owner or operator of a new or existing 

affected source must comply at all times with each applicable 

limit in this section, including periods of startup and 

shutdown. Table 1 to this subpart summarizes the emission 

standards for each type of source.

(2) For a new or existing affected sources subject to an 

emissions limit in paragraphs (b) through (j) of this section 

expressed in units of pounds per ton of feed, or μg TEQ or ng 

TEQ per Mg of feed, calculate your emissions during periods of 

startup and shutdown by dividing your measured emissions in 

lb/hr or μg/hr or ng/hr by the appropriate feed rate in tons/hr

or Mg/hr from your most recent or current performance test.

* * * * *

(i) * * *
Page 163 of 236

(4) 0.20 kg of HF per Mg (0.40 lb of HF per ton) of 

feed/charge from an uncontrolled group 1 furnace and 0.20 kg of 

HCl per Mg (0.40 lb of HCl per ton) of feed/charge or, if the 

furnace is equipped with an add-on air pollution control device, 

10 percent of the uncontrolled HCl emissions, by weight, for a 

group 1 furnace at a secondary aluminum production facility that 

is a major source. 

* * * * *

(k) Secondary aluminum processing unit. On and after the 

compliance date established by §63.1501, the owner or operator 

must comply with the emission limits calculated using the 

equations for PM, HCl and HF in paragraphs (k)(1) and (2) of 

this section for each secondary aluminum processing unit at a 

secondary aluminum production facility that is a major source. 

The owner or operator must comply with the emission limit 

calculated using the equation for D/F in paragraph (k)(3) of 

this section for each secondary aluminum processing unit at a 

secondary aluminum production facility that is a major or area 

source.

(1) The owner or operator must not discharge or allow to be 

discharged to the atmosphere any 3-day, 24-hour rolling average 

emissions of PM in excess of:
Page 164 of 236

 

 

(Eq.1)

T

L T

L n

i 1

ti

n

i 1

ti ti

C

PM

PM 











Where,

LtiPM= The PM emission limit for individual emission unit i in 

paragraph (i)(1) and (2) of this section for a group 1 furnace 

or in paragraph (j)(2) of this section for an in-line fluxer;

Tti= The mass of feed/charge for 24 hours for individual emission 

unit i; and

LcPM= The daily PM emission limit for the secondary aluminum 

processing unit which is used to calculate the 3-day, 24-hour PM 

emission limit applicable to the SAPU.

Note: In-line fluxers using no reactive flux materials cannot be 

included in this calculation since they are not subject to the 

PM limit.

(2) The owner or operator must not discharge or allow to be 

discharged to the atmosphere any 3-day, 24-hour rolling average 

emissions of HCl or HF in excess of:

 

 

(Eq. 2)

T

L T

L n

i 1

ti

n

i 1

tiHCl/HF ti

cHCl/HF













Where,

LtiHCl/HF= The HCl emission limit for individual emission unit i in 

paragraph (i)(4) of this section for a group 1 furnace or in 
Page 165 of 236

paragraph (j)(1) of this section for an in-line fluxer; or the 

HF emission limit for individual emission unit i in paragraph 

(i)(4) of this section for an uncontrolled group 1 furnace; and

LcHCl/HF= The daily HCl or HF emission limit for the secondary 

aluminum processing unit which is used to calculate the 3-day, 

24-hour HCl or HF emission limit applicable to the SAPU.

Note: Only uncontrolled group 1 furnaces are included in this HF 

limit calculation and in-line fluxers using no reactive flux 

materials cannot be included in this calculation since they are 

not subject to the HCl limits.

(3) The owner or operator must not discharge or allow to be 

discharged to the atmosphere any 3-day, 24-hour rolling average 

emissions of D/F in excess of:

 

 

(Eq. 3)

T

L T

L n

i 1

ti

n

i 1

tiD/F ti

cD/F













Where,

LtiD/F= The D/F emission limit for individual emission unit i in 

paragraph (i)(3) of this section for a group 1 furnace; and

LcD/F= The daily D/F emission limit for the secondary aluminum 

processing unit which is used to calculate the 3-day, 24-hour 

D/F emission limit applicable to the SAPU.

Note: Clean charge furnaces cannot be included in this 

calculation since they are not subject to the D/F limit.
Page 166 of 236

* * * * *

6. Section 63.1506 is amended by: 

a. By revising paragraph (a)(1); 

b. By adding paragraph (a)(5); 

c. By revising paragraph (c)(1); 

d. By revising paragraph (g)(5); 

e. By revising paragraph (k)(3); 

f. By revising paragraph (m)(4); and

g. By revising paragraph (n)(1) to read as follows:

§63.1506 Operating requirements.

(a) * * *

(1) On and after the compliance date established by 

§63.1501, the owner or operator must operate all new and 

existing affected sources and control equipment according to the 

requirements in this section. The affected sources, and their 

associated control equipment, listed in §63.1500(c)(1)through(4) 

of this subpart that are located at a secondary aluminum 

production facility that is an area source are subject to the 

operating requirements of paragraphs (b), (c), (d), (f), (g), 

(h), (m), (n), and (p) of this section.

* * * * *

(5) 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 
Page 167 of 236

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.

* * * * *

(c) * * *

(1) Design and install a system for the capture and 

collection of emissions to meet the engineering standards for 

minimum exhaust rates as published by the American Conference of 

Governmental Industrial Hygienists in “Industrial Ventilation: A 

Manual of Recommended Practice” 23rd or 27th edition (ACGIH 

Guidelines) (incorporated by reference in §63.1502 of this 

subpart);

* * * * *

(g) * * *

(5) For a continuous injection device, maintain freeflowing lime in the hopper to the feed device at all times and 

maintain the lime feeder setting at or above the level 

established during the performance test.

* * * * *

(k) * * *
Page 168 of 236

(3) For a continuous injection system, maintain freeflowing lime in the hopper to the feed device at all times and 

maintain the lime feeder setting at or above the level 

established during the performance test.

* * * * *

(m) * * *

(4) For a continuous lime injection system, maintain freeflowing lime in the hopper to the feed device at all times and 

maintain the lime feeder setting at or above the level 

established during the performance test.

* * * * *

(n) * * *

(1) Maintain the total reactive chlorine flux injection 

rate and fluorine flux addition rate for each operating cycle or 

time period used in the performance test at or below the average 

rate established during the performance test.

* * * * *

7. Section 63.1510 is amended by: 

a. Revising paragraph (a); 

b. Revising paragraph (b); 

c. Revising paragraph (b)(5);

d. Adding paragraph (b)(9);

e. Revising paragraph (d)(2); 

f. Revising paragraph (f)(1)(ii); 
Page 169 of 236

g. Adding paragraph (i)(4); 

h. Revising paragraph (j)(4); 

i. Revising paragraph (n)(1); 

j. Revising paragraph (o)(1); 

k. Revising paragraph (o)(1)(ii); 

l. Revising paragraph (s)(2)(iv);

m. Revising paragraph (t); 

n. Adding paragraph (t)(2)(i);

o. Adding paragraph (t)(2)(ii); 

p. Revising paragraph (t)(4); and 

q. Revising paragraph (t)(5)to read as follows:

§63.1510 Monitoring requirements.

(a) Summary. On and after the compliance date established 

by §63.1501, the owner or operator of a new or existing affected 

source or emission unit must monitor all control equipment and 

processes according to the requirements in this section. 

Monitoring requirements for each type of affected source and 

emission unit are summarized in Table 3 to this subpart. Area 

sources are subject to monitoring requirements for those 

affected sources listed in §63.1500(c)(1)-(4)of this subpart, 

and associated control equipment as required by paragraphs (b)

through (k), (n) through (q), and (s) through (w) of this 

section, including but not limited to:
Page 170 of 236

(1) The operation, maintenance and monitoring plan required 

in paragraph (b) of this section pertaining to each affected 

source listed in §63.1500(c)(1)-(4) of this subpart,

(2) The labeling requirements described in paragraph (c) of 

this section pertaining to group 1 furnaces processing other 

than clean charge, and scrap dryer/delacquering kiln/decoating 

kilns,

(3) The requirements for capture and collection described

in paragraph (d) of this section for each controlled affected 

source listed in §63.1500(c)(1)-(4) of this subpart,

(4) The feed charge weight monitoring requirements 

described in paragraph (e) of this section applicable to group 1 

furnaces processing other than clean charge, scrap 

dryer/delacquering kiln/decoating kilns and thermal chip dryers,

(5) The bag leak detection system requirements described in 

paragraph (f) of this section applicable to all bag leak 

detection systems installed on fabric filters and lime injected 

fabric filters used to control each affected source listed in 

§63.1500(c)(1)-(4) of this subpart,

(6) The requirements for afterburners described in 

paragraph (g) of this section applicable to sweat furnaces, 

thermal chip dryers, and scrap dryer/delacquering kiln/decoating 

kilns,
Page 171 of 236

(7) The requirements for monitoring fabric filter inlet 

temperature described in paragraph (h) of this section for all 

lime injected fabric filters used to control group 1 furnaces 

processing other than clean charge, sweat furnaces and scrap 

dryer/delacquering kiln/decoating kilns,

(8) The requirements for monitoring lime injection 

described in paragraph (i) of this section applicable to all 

lime injected fabric filters used to control emissions from 

group 1 furnaces processing other than clean charge, thermal 

chip dryers, sweat furnaces and scrap dryer/delacquering 

kiln/decoating kilns,

(9) The requirements for monitoring total reactive flux 

injection described in paragraph (j) of this section for all 

group 1 furnaces processing other than clean charge, 

(10) The requirements described in paragraph (k) of this 

section for thermal chip dryers,

(11) The requirements described in paragraph (n) of this 

section for controlled group 1 sidewell furnaces processing 

other than clean charge,

(12) The requirements described in paragraph (o) of this 

section for uncontrolled group 1 sidewell furnaces processing 

other than clean charge,
Page 172 of 236

(13) The requirements described in paragraph (p) of this 

section for scrap inspection programs for uncontrolled group 1 

furnaces,

(14) The requirements described in paragraph (q) of this 

section for monitoring scrap contamination level for 

uncontrolled group 1 furnaces,

(15) The requirements described in paragraph (s) of this 

section for secondary aluminum processing units, limited to 

compliance with limits for emissions of D/F from group 1 

furnaces processing other than clean charge,

(16) The requirements described in paragraph (t) of this 

section for secondary aluminum processing units limited to 

compliance with limits for emissions of D/F from group 1 

furnaces processing other than clean charge,

(17) The requirements described in paragraph (u) of this 

section for secondary aluminum processing units limited to 

compliance with limits for emissions of D/F from group 1 

furnaces processing other than clean charge,

(18) The requirements described in paragraph (v) of this 

section for alternative lime addition monitoring methods 

applicable to lime coated fabric filters used to control 

emissions from group 1 furnaces processing other than clean 

charge, thermal chip dryers, sweat furnaces and scrap 

dryer/delacquering kiln/decoating kilns, and
Page 173 of 236

(19) The requirements described in paragraph (w) of this 

section for approval of alternate methods for monitoring group 1 

furnaces processing other than clean charge, thermal chip 

dryers, scrap dryer/delacquering kiln/decoating kilns and sweat 

furnaces and associated control devices for the control of D/F 

emissions.

(b) Operation, maintenance, and monitoring (OM&M) plan. The 

owner or operator must prepare and implement for each new or 

existing affected source and emission unit, a written operation, 

maintenance, and monitoring (OM&M) plan. The owner or operator 

of an existing affected source must submit the OM&M plan to the 

responsible permitting authority no later than the compliance 

date established by §63.1501(a). The owner or operator of any 

new affected source must submit the OM&M plan to the responsible 

permitting authority within 90 days after a successful initial 

performance test under §63.1511(b), or within 90 days after the 

compliance date established by §63.1501(b) if no initial 

performance test is required. The plan must be accompanied by a 

written certification by the owner or operator that the OM&M 

plan satisfies all requirements of this section and is otherwise 

consistent with the requirements of this subpart. The owner or 

operator must comply with all of the provisions of the OM&M plan 

as submitted to the permitting authority, unless and until the 

plan is revised in accordance with the following procedures. If 
Page 174 of 236

the permitting authority determines at any time after receipt of 

the OM&M plan that any revisions of the plan are necessary to 

satisfy the requirements of this section or this subpart, the 

owner or operator must promptly make all necessary revisions and 

resubmit the revised plan. If the owner or operator determines 

that any other revisions of the OM&M plan are necessary, such 

revisions will not become effective until the owner or operator 

submits a description of the changes and a revised plan 

incorporating them to the permitting authority. The owner or 

operator must not begin operating under the revised plan until 

approval is received or until after 60 days, whichever is 

sooner. Each plan must contain the following information:

* * * * *

(5) Procedures for monitoring process and control device

parameters, including lime injection rates, procedures for annual 

inspections of afterburners, and if applicable, the procedure to be 

used for determining charge/feed (or throughput) weight if a 

measurement device is not used.

* * * * *

(9) Procedures to be followed when changing furnace 

classification under the provisions of §63.1514.

* * * * *

(d) * * *
Page 175 of 236

(2) Inspect each capture/collection and closed vent system 

at least once each calendar year to ensure that each system is 

operating in accordance with the operating requirements in 

§63.1506(c) and record the results of each inspection. This 

inspection shall include a volumetric flow rate measurement 

taken at a location in the ductwork downstream of the hoods 

which will be representative of the actual volumetric flow rate 

without the interference of leaks, the introduction of ambient 

air for cooling, or other ducts manifolded from other hoods. The 

measurement shall be performed using EPA Reference Methods 1 and 

2 in appendix A to 40 CFR part 60. 

* * * * *

(f) * * *

(1) * * *

(ii) Each bag leak detection system must be installed, 

calibrated, operated, and maintained according to the 

manufacturer’s operating instructions. 

* * * * *

(i) * * *

(4) At least once per month, verify that the lime injection 

rate in pound per hour (lb/hr) is no less than 90 percent of the 

lime injection rate used to demonstrate compliance during your 

performance test.

(j) * * *
Page 176 of 236

(4) Calculate and record the total reactive flux injection 

rate for each operating cycle or time period used in the 

performance test using the procedure in §63.1512(o). For solid 

flux that is added intermittently, record the amount added for 

each operating cycle or time period used in the performance test 

using the procedures in §63.1512(o). 

* * * * *

(n) * * *

(1) Record in an operating log for each tap of a sidewell 

furnace whether the level of molten metal was above the top of 

the passage between the sidewell and hearth during reactive flux 

injection, unless the furnace hearth was also equipped with an 

add-on control device. If visual inspection of the molten metal 

level is not possible, the molten metal level must be determined 

using physical measurement methods.

(2) Submit a certification of compliance with the 

operational standards in §63.1506(m)(6) for each 6-month 

reporting period. Each certification must contain the 

information in §63.1516(b)(2)(iii).

(o) * * *

(1) The owner or operator must develop, in consultation 

with the responsible permitting authority, a written sitespecific monitoring plan. The site-specific monitoring plan must 

be submitted to the permitting authority as part of the OM&M 
Page 177 of 236

plan. The site-specific monitoring plan must contain sufficient 

procedures to ensure continuing compliance with all applicable 

emission limits and must demonstrate, based on documented test 

results, the relationship between emissions of PM, HCl (and, for 

uncontrolled group 1 furnaces, HF), and D/F and the proposed 

monitoring parameters for each pollutant. Test data must 

establish the highest level of PM, HCl (and, for uncontrolled 

group 1 furnaces, HF), and D/F that will be emitted from the 

furnace. This may be determined by conducting performance tests 

and monitoring operating parameters while charging the furnace 

with feed/charge materials containing the highest anticipated 

levels of oils and coatings and fluxing at the highest 

anticipated rate. If the permitting authority determines that 

any revisions of the site-specific monitoring plan are necessary 

to meet the requirements of this section or this subpart, the 

owner or operator must promptly make all necessary revisions and 

resubmit the revised plan to the permitting authority.

* * * * *

(ii) The permitting authority will review and approve or 

disapprove a proposed plan, or request changes to a plan, based 

on whether the plan contains sufficient provisions to ensure 

continuing compliance with applicable emission limits and 

demonstrates, based on documented test results, the relationship 

between emissions of PM, HCl (for uncontrolled group 1 furnaces, 
Page 178 of 236

HF) and D/F and the proposed monitoring parameters for each 

pollutant. Test data must establish the highest level of PM, HCl

(for uncontrolled group 1 furnaces, HF) and D/F that will be 

emitted from the furnace. Subject to permitting agency approval 

of the OM&M plan, this may be determined by conducting 

performance tests and monitoring operating parameters while 

charging the furnace with feed/charge materials containing the 

highest anticipated levels of oils and coatings and fluxing at 

the highest anticipated rate.

* * * * *

(s) * * *

(2) * * *

(iv) The inclusion of any periods of startup or shutdown in 

emission calculations.

* * * * *

(t) Secondary aluminum processing unit. Except as provided 

in paragraph (u) of this section, the owner or operator must 

calculate and record the 3-day, 24-hour rolling average 

emissions of PM, HCl (for uncontrolled group 1 furnaces, HF) and

D/F for each secondary aluminum processing unit on a daily 

basis. To calculate the 3-day, 24-hour rolling average, the 

owner or operator must:

* * * * *

(2) * * *
Page 179 of 236

(i) Where no performance test has been conducted, for a 

particular emission unit, because the owner of operator has, 

with the approval of the permitting authority, chosen to 

determine the emission rate of an emission unit by testing a 

representative unit, in accordance with §63.1511(f), the owner 

of operator shall use the emission rate determined from the 

representative unit in the SAPU emission rate calculation 

required in §63.1510(t)(4).

(ii) If the owner or operator has not conducted performance 

tests for HCl and HF for an uncontrolled group 1 furnace or for 

HCL for an in-line fluxer, in accordance with the provisions of 

§63.1512(d)(3), (e)(3), or (h)(2), the calculation required in 

§63.1510(t)(4) to determine SAPU-wide HCl and HF emissions shall 

be made under the assumption that all chlorine-containing 

reactive flux added to the emission unit is emitted as HCl and 

all fluorine-containing reactive flux added to the emission unit 

is emitted as HF.

* * * * *

(4) Compute the 24-hour daily emission rate using Equation

4:

 

 

(Eq. 4)

T

T ER

E n

i 1

i

n

i 1

i i

day













Where,
Page 180 of 236

Eday= The daily PM, HCl, D/F and, for uncontrolled group 1 

furnaces, HF emission rate for the secondary aluminum processing 

unit for the 24-hour period;

Ti= The total amount of feed, or aluminum produced, for 

emission unit i for the 24-hour period (tons or Mg);

ERi= The measured emission rate for emission unit i as 

determined in the performance test (lb/ton or μg/Mg of 

feed/charge); and

n = The number of emission units in the secondary aluminum 

processing unit.

(5) Calculate and record the 3-day, 24-hour rolling average 

for each pollutant each day by summing the daily emission rates 

for each pollutant over the 3 most recent consecutive days and 

dividing by 3. The SAPU is in compliance with an applicable 

emission limit if the 3-day, 24-hour rolling average for each 

pollutant is no greater than the applicable SAPU emission limit 

determined in accordance with §63.1505(k)(1)-(3).

* * * * *

8. Section 63.1511 is amended by: 

a. By revising paragraph (a);

b. By revising paragraph (b);

c. By revising paragraph (b)(1); 

d. By adding paragraph (b)(6); 

e. By revising paragraph (c)(9); 
Page 181 of 236

f. By adding paragraph (f)(6); and

g. By adding paragraph (g)(5) to read as follows:

§63.1511 Performance test/compliance demonstration general 

requirements.

(a) Site-specific test plan. Prior to conducting any 

performance test required by this subpart, the owner or operator 

must prepare a site-specific test plan which satisfies all of 

the requirements, and must obtain approval of the plan pursuant 

to the procedures, set forth in §63.7(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.

(b) Initial performance test. Following approval of the 

site-specific test plan, the owner or operator must demonstrate 

initial compliance with each applicable emission, equipment, 

work practice, or operational standard for each affected source 

and emission unit, and report the results in the notification of 

compliance status report as described in §63.1515(b). The owner 

or operator of any existing affected source for which an initial 

performance test is required to demonstrate compliance must 

conduct this initial performance test no later than the date for 
Page 182 of 236

compliance established by §63.1501(a). The owner or operator of 

any new affected source for which an initial performance test is 

required must conduct this initial performance test within 180 

days after the date for compliance established by §63.1501(b). 

Except for the date by which the performance test must be 

conducted, the owner or operator must conduct each performance 

test in accordance with the requirements and procedures set 

forth in §63.7(c). Owners or operators of affected sources 

located at facilities which are area sources are subject only to 

those performance testing requirements pertaining to D/F. Owners 

or operators of sweat furnaces meeting the specifications of 

§63.1505(f)(1) are not required to conduct a performance test.

(1) The performance tests must be conducted with the scrap 

containing the highest level of contamination, at the highest 

rate of production and using the highest reactive fluxing rate 

while an air pollution control device is operating. Any 

subsequent performance tests for the purposes of establishing 

new or revised parametric limits shall be allowed upon preapproval from the permitting authorities as specified in the 

site-specific test plan. These new parametric settings shall be 

used to demonstrate compliance for the period being tested.

* * * * *

(6) Apply paragraphs (b)(1) through (5) of this section for 

each pollutant separately if a different production rate, charge 
Page 183 of 236

material or, if applicable, reactive fluxing rate would apply 

and thereby result in a higher expected emissions rate for that 

pollutant.

(c) * * *

(9) Method 26A for the concentration of HCl and HF. Where a 

lime-injected fabric filter is used as the control device to 

comply with the 90 percent reduction standard, the owner or 

operator must measure the fabric filter inlet concentration of 

HCl at a point before lime is introduced to the system. 

* * * * *

(f) * * *

(6) All 3 separate runs of a performance test must be 

conducted on the same unit.

(g) * * *

(5) If the owner or operator wants to conduct a new 

performance test and establish different operating parameter 

values, they must meet the requirements in paragraphs (g)(1) 

through (4) of this section and submit a revised site specific 

test plan and receive approval in accordance with paragraph (a) 

of this section.

* * * * *

9. Section 63.1512 is amended by: 

a. By revising paragraph (e)(1);

b. By revising paragraph (e)(2); 
Page 184 of 236

c. By revising paragraph (e)(3); 

d. By adding paragraphs (e)(4); 

e. By adding paragraphs (e)(5); 

f. By revising paragraph (h)(1); 

g. By revising paragraph (h)(2); 

h. By revising paragraph (j); 

i. By revising paragraph (j)(1)(i); 

j. By revising paragraph (j)(2)(i); 

k. By revising paragraph (o)(1); 

l. By revising paragraph (p); and

m. By revising paragraph (p)(2)to read as follows:

§63.1512 Performance test/compliance demonstration requirements 

and procedures.

* * * * *

(e) * * *

(1) If the group 1 furnace processes other than clean 

charge material, the owner or operator must conduct emission 

tests to measure emissions of PM, HCl, HF, and D/F.

(2) If the group 1 furnace processes only clean charge, the 

owner or operator must conduct emission tests to simultaneously 

measure emissions of PM , HCl and HF. A D/F test is not 

required. Each test must be conducted while the group 1 furnace 

(including a melting/holding furnace) processes only clean 

charge.
Page 185 of 236

(3) The owner or operator may choose to determine the rate 

of reactive flux addition to the group 1 furnace and assume, for 

the purposes of demonstrating compliance with the SAPU emission 

limit, that all reactive flux added to the group 1 furnace is 

emitted. Under these circumstances, the owner or operator is not 

required to conduct an emission test for HCl or HF.

(4) When testing an existing uncontrolled furnace, the 

owner or operator must comply with the requirements of either

paragraph (e)(4)(i) or paragraph (e)(4)(ii) of this section at 

the next required performance test.

(i) Install hooding that meets ACGIH Guidelines, or

(ii) Assume a 67 percent capture efficiency for the furnace 

exhaust (i.e., multiply emissions measured at the furnace 

exhaust outlet by 1.5) if hooding does not meet ACGIH 

Guidelines. If the source fails to demonstrate compliance using 

the 67 percent capture efficiency assumption, the owner or 

operator must re-test with a hood that meets the ACGIH 

Guidelines within 90 days, or petition the permitting authority 

that such hoods are impracticable and propose testing procedures 

that will minimize fugitive emissions.

(5) When testing a new uncontrolled furnace the owner or 

operator must either: 

(i) Install hooding that meets ACGIH Guidelines, or 
Page 186 of 236

(ii) Petition the permitting authority that such hoods are 

impracticable and propose testing procedures that will minimize 

fugitive emissions.

* * * * *

(h) * * *

(1) The owner or operator of an in-line fluxer that uses 

reactive flux materials must conduct a performance test to 

measure emissions of HCl and PM or otherwise demonstrate 

compliance in accordance with paragraph (h)(2) of this section. 

If the in-line fluxer is equipped with an add-on control device, 

the emissions must be measured at the outlet of the control 

device.

(2) The owner or operator may choose to limit the rate at 

which reactive flux is added to an in-line fluxer and assume, 

for the purposes of demonstrating compliance with the SAPU 

emission limit, that all chlorine in the reactive flux added to 

the in-line fluxer is emitted as HCl. Under these circumstances, 

the owner or operator is not required to conduct an emission 

test for HCl. If the owner or operator of any in-line flux box 

which has no ventilation ductwork manifolded to any outlet or 

emission control device chooses to demonstrate compliance with 

the emission limits for HCl by limiting use of reactive flux and 

assuming that all chlorine in the flux is emitted as HCl, 

compliance with the HCl limit shall also constitute compliance 
Page 187 of 236

with the emission limit for PM, and no separate emission test 

for PM is required. In this case, the owner or operator of the 

unvented in-line flux box must utilize the maximum permissible 

PM emission rate for the in-line flux boxes when determining the 

total emissions for any SAPU which includes the flux box.

* * * * *

(j) Secondary aluminum processing unit. The owner or 

operator must conduct performance tests as described in 

paragraphs (j)(1) through (3) of this section. The results of 

the performance tests are used to establish emission rates in 

lb/ton of feed/charge for PM, HCl and HF and μg TEQ/Mg of 

feed/charge for D/F emissions from each emission unit. These 

emission rates are used for compliance monitoring in the 

calculation of the 3-day, 24-hour rolling average emission rates 

using the equation in §63.1510(t). A performance test is 

required for:

(1) * * *

(i) Emissions of HCl or HF (for the emission limits); or

* * * * *

(2) * * *

(i) Emissions of HCl or HF (for the emission limits); or

* * * * *

(o) * * *
Page 188 of 236

(1) Continuously measure and record the weight of gaseous 

or liquid reactive flux injected for each 15 minute period 

during the HCl, HF and D/F tests, determine and record the 15-

minute block average weights, and calculate and record the total 

weight of the gaseous or liquid reactive flux for the 3 test 

runs;

* * * * *

(p) * * *

(2) Record the feeder setting and lime injection rate for 

the 3 test runs. If the feed rate setting and lime injection 

rates vary during the runs, determine and record the average 

feed rate and lime injection rate from the 3 runs.

* * * * *

10. Section 63.1513 is amended by: 

a. By revising paragraph (b)

b. By revising paragraph (b)(1); 

c. By revising paragraph (e)(1);

d. By revising paragraph (e)(2); and 

e. By revising paragraph (e)(3)to read as follows:

§63.1513 Performance test/compliance demonstration requirements 

and procedures.

* * * * *
Page 189 of 236

(b) PM, HCl, HF and D/F emission limits. (1) Use Equation 7 

of this section to determine compliance with an emission limit 

for PM, HCl or HF:

(Eq. 7)

P

C Q K

E

  l  Where:

E = Emission rate of PM, HCl or HF, kg/Mg (lb/ton) of feed;

C = Concentration of PM, HCl or HF, g/dscm (gr/dscf);

Q = Volumetric flow rate of exhaust gases, dscm/hr (dscf/hr);

K1= Conversion factor, 1 kg/1,000 g (1 lb/7,000 gr); and

P = Production rate, Mg/hr (ton/hr).

* * * * *

(e) * * *

(1) Use Equation 9 to compute the mass-weighted PM 

emissions for a secondary aluminum processing unit. Compliance 

is achieved if the mass-weighted emissions for the secondary 

aluminum processing unit (EcPM) is less than or equal to the 

emission limit for the secondary aluminum processing unit (LcPM) 

calculated using Equation 1 in §63.1505(k).

 

 

(Eq. 9)

T

E n

i 1

ti

n

i 1

cPM













Eti Tti PM

Where,

EcPM= The mass-weighted PM emissions for the secondary aluminum 

processing unit;
Page 190 of 236

EtiPM= Measured PM emissions for individual emission unit, or 

group of co-controlled emission units, i;

Tti= The average feed rate for individual emission unit i during 

the operating cycle or performance test period, or the sum of 

the average feed rates for all emission units in the group of 

co-controlled emission unit i; and

n= The number of individual emission units, and groups of cocontrolled emission units in the secondary aluminum processing 

unit.

(2) Use Equation 10 to compute the aluminum mass-weighted 

HCl or HF emissions for the secondary aluminum processing unit. 

Compliance is achieved if the mass-weighted emissions for the 

secondary aluminum processing unit (EcHCl/HF) is less than or equal 

to the emission limit for the secondary aluminum processing unit 

(LcHCl/HF) calculated using Equation 2 in §63.1505(k).

 

 

(Eq.10)

T

T

E n

i 1

ti

n

i 1

/ ti

cHCl/HF













EtiHCl HF

Where,

EcHCl/HF= The mass-weighted HCl or HF emissions for the secondary 

aluminum processing unit; and

EtiHCl/HF= Measured HCl or HF emissions for individual emission 

unit, or group of co-controlled emission units i.
Page 191 of 236

(3) Use Equation 11 to compute the aluminum mass-weighted 

D/F emissions for the secondary aluminum processing unit. 

Compliance is achieved if the mass-weighted emissions for the 

secondary aluminum processing unit is less than or equal to the 

emission limit for the secondary aluminum processing unit (LcD/F) 

calculated using Equation 3 in §63.1505(k).

 

 

(Eq.11)

T

E T

E n

i 1

ti

n

i 1

ti ti

cD/F

D/F













Where,

EcD/F= The mass-weighted D/F emissions for the secondary aluminum 

processing unit; and

EtiD/F= Measured D/F emissions for individual emission unit, or 

group of co-controlled emission units i.

* * * * *

11. Section 63.1514 is revised to read as follows:

§63.1514 Change of Furnace Classification.

The requirements of this section are in addition to the 

other requirement of this subpart that apply to group 1 and 

group 2 furnaces.

(a) Changing from a group 1 controlled furnace processing 

other than clean charge to group 1 uncontrolled furnace 

processing other than clean charge. 
Page 192 of 236

An owner or operator wishing to change operating modes must 

conduct performance tests to demonstrate to the regulatory

authority that compliance can be achieved under both modes. 

Operating parameters relevant to each mode of operation must be 

established during the performance test. 

(1) Operators of major sources must conduct performance 

tests for PM, HCl and D/F, according to the procedures in 

§63.1512(d) with the capture system and control device operating 

normally. Performance tests must be repeated at least once every 

5 years to demonstrate compliance for each operating mode.

(i) The performance tests must be conducted with the scrap 

containing the highest level of contamination expected to be 

processed, at the highest throughput expected and using the 

highest rate of reactive flux injection expected to be processed 

in controlled mode.

(ii)Parameters for capture, flux rate, and lime injection 

must be established during these tests.

(iii) The emission factors for this mode of operation, for 

use in the demonstration of compliance with the emission limits 

for SAPUs specified in §63.1505(k) must be determined.

(2) Operators of major sources must conduct additional

performance tests for PM, HCl, HF and D/F, according to the 

procedures in §63.1512(e) without operating a control device.
Page 193 of 236

Performance tests must be repeated at least once every 5 years 

to demonstrate compliance with each operating mode.

(i) Testing under this paragraph may be conducted at any 

time after the furnace has completed 1 or more charge to tap 

cycles, or 24 operating hours with scrap of the highest level of 

contamination expected to be processed in uncontrolled mode.

(ii) Testing under this paragraph must be conducted with 

furnace emissions captured in accordance with the provisions of 

§63.1512(e)(4) and directed to the stack or vent tested.

(iii) Parameters for capture and flux rate must be 

established during these tests.

(iv) The emission factors for this mode of operation, for 

use in the demonstration of compliance with the emission limits 

for SAPUs specified in §63.1505(k) must be determined.

(3) Operators of area sources must conduct performance 

tests for D/F, according to the procedures in §63.1512(d) with

the capture system and control device operating normally.

(i) The performance tests must be conducted with the scrap 

containing the highest level of contamination expected to be 

processed, at the highest throughput expected to be processes 

and using the highest rate of reactive flux expected to be

injected in controlled mode.

(ii) Parameters for capture, flux rate, and lime injection 

must be established during these tests.
Page 194 of 236

(iii) The emission factors for this mode of operation, for 

use in the demonstration of compliance with the emission limits 

for SAPUs specified in §63.1505(k) must be determined.

(4) Operators of area sources must conduct performance 

tests for D/F, according to the procedures in §63.1512(e) 

without operating a control device.

(i) Testing under this paragraph may be conducted at any 

time after the furnace has completed 1 or more charge to tap 

cycles, or 24 operating hours with scrap of the highest level of 

contamination expected to be processed in uncontrolled mode.

(ii) Testing under this paragraph must be conducted with 

furnace emissions captured in accordance with the provisions of 

§63.1506(c) and directed to the stack or vent tested.

(iii) Parameters for capture and flux rate must be 

established during these tests. In addition, the number of 

cycles of furnace operation with scrap of the highest level of 

contamination expected to be processed in uncontrolled mode that 

elapsed prior to the performance test(s) conducted in 

uncontrolled mode is established as a parameter.

(iv) The D/F emission factor for this mode of operation, 

for use in the demonstration of compliance with the emission 

limits for SAPUs specified in §63.1505(k) must be determined.

(5) To change modes of operation from uncontrolled to 

controlled, the owner or operator must, before charging scrap to 
Page 195 of 236

the furnace that exceeds the contaminant level established for 

uncontrolled mode,

(i) Change the label on the furnace to reflect controlled 

operation,

(ii) Direct the furnace emissions to the control device, 

and

(iii) Begin lime addition to the control device at the rate 

established for controlled mode.

(6) To change modes of operation from controlled to 

uncontrolled, the owner or operator must, before turning off or 

bypassing the control device,

(i) Change the label on the furnace to reflect controlled 

operation, 

(ii) Charge scrap with a level of contamination no greater 

than that used in the performance test for uncontrolled furnaces 

for the number of charge to tap cycles that elapsed with scrap 

of a contamination level no higher than that used in the 

uncontrolled mode performance test(s), and

(iii) Decrease the flux addition rate to no higher than the 

flux addition rate used in the uncontrolled mode performance 

test.

(7) In addition to the recordkeeping requirements of 

§63.1517, the owner or operator must maintain records of the 

nature of each mode change (controlled to uncontrolled, or 
Page 196 of 236

uncontrolled to controlled), the time the change is initiated, 

and the time the exhaust gas is diverted from control device to 

bypass or bypass to control device. 

(b) Changing from a group 1 controlled furnace processing 

other than clean charge to a group 1 uncontrolled furnace 

processing clean charge. An owner or operator wishing to operate 

under controlled mode with other than clean charge and 

uncontrolled mode with clean charge must conduct performance 

tests to demonstrate to the delegated regulatory authority that 

compliance can be achieved in both modes. Operating parameters 

relevant to each mode of operation must be established during 

the performance test. 

(1) Operators of major sources must conduct performance 

tests for PM, HCl and D/F, according to the procedures in 

§63.1512 with the capture system and control device operating 

normally. Performance tests must be repeated at least once every 

5 years to demonstrate compliance for each operating mode.

(i) The performance tests must be conducted with the scrap 

containing the highest level of contamination expected to be 

processed, at the highest throughput expected to be processed 

and using the highest rate of reactive flux injection expected 

in controlled mode.

(ii) Parameters for capture, flux rate, and lime injection 

must be established during these tests.
Page 197 of 236

(iii) The emission factors for this mode of operation, for 

use in the demonstration of compliance with the emission limits 

for SAPUs specified in §63.1505(k) must be determined.

(2) Operators of major sources must conduct performance 

tests for PM, HCl and D/F, according to the procedures in 

§63.1512 without operating a control device. Performance tests 

must be repeated at least once every 5 years to demonstrate 

compliance for each operating mode.

(i) Testing under this paragraph may be conducted at any 

time after the furnace has completed 1 or more charge to tap 

cycles with clean charge.

(ii) Testing under this paragraph must be conducted with 

furnace emissions captured in accordance with the provisions of 

§63.1506(c) and directed to the stack or vent tested.

(iii) Parameters for capture and flux rate must be 

established during these tests.

(iv) Emissions of D/F during this test must not exceed 1.5 

μg TEQ/Mg of feed/charge processed, or this mode of operation is 

not allowed.

(v) The emission factors for PM, HCl and HF for this mode 

of operation, for use in the demonstration of compliance with 

the emission limits for SAPUs specified in §63.1505(k) must be 

determined.
Page 198 of 236

(3) Operators of area sources must conduct additional

performance tests for D/F, according to the procedures in 

§63.1512 with the capture system and control device operating 

normally.

(i) The performance tests must be conducted with the scrap 

containing the highest level of contamination expected to be 

processed, at the highest throughput expected to be processed 

and using the highest rate of reactive flux injection expected 

in controlled mode.

(ii) Parameters for capture, flux rate, and lime injection 

must be established during these tests.

(iii) The D/F emission factor for this mode of operation, 

for use in the demonstration of compliance with the emission 

limits for SAPUs specified in §63.1505(k) must be determined.

(4) Operators of area sources must conduct additional

performance tests for D/F, according to the procedures in 

§63.1512(e) without operating a control device.

(i) Testing may be conducted at any time after the furnace 

has completed 1 or more charge to tap cycles with scrap of the 

highest level of contamination expected to be processed in 

uncontrolled mode at the highest throughput expected to be 

processed in uncontrolled mode.
Page 199 of 236

(ii) Testing under this paragraph must be conducted with 

furnace emissions captured in accordance with the provisions of 

§63.1506(c) and directed to the stack or vent tested.

(iii) Parameters for flux rate must be established during 

these tests. In addition the number of cycles of furnace 

operation with scrap of the highest level of contamination 

expected to be processed in uncontrolled mode that elapsed prior 

to the performance test(s) conducted in uncontrolled mode is 

established as a parameter.

(iv) The D/F emission factor for this mode of operation, 

for use in the demonstration of compliance with the emission 

limits for SAPUs specified in §63.1505(k) must be determined.

(5) To change modes of operation from uncontrolled to 

controlled, the owner or operator must, before charging scrap to 

the furnace that exceeds the contaminant level established for 

uncontrolled mode,

(i) Change the label on the furnace to reflect controlled 

operation,

(ii)Direct the furnace emissions to the control device, and

(iii) Begin lime addition to the control device at the rate 

established for controlled mode.

(6) To change modes of operation from controlled to 

uncontrolled, the owner or operator must, before turning off or 

bypassing the control device,
Page 200 of 236

(i) Change the label on the furnace to reflect controlled 

operation, 

(ii) Charge clean charge for the number of charge to tap 

cycles that elapsed before the uncontrolled mode performance 

test was conducted, and

(iii) Decrease the flux addition rate to no higher than the 

flux addition rate used in the uncontrolled mode performance 

test.

(7) In addition to the recordkeeping requirements of 

§63.1517, the owner or operator must maintain records of the 

nature of each mode change (controlled to uncontrolled, or 

uncontrolled to controlled), the time the furnace operating mode 

change is initiated, and the time the exhaust gas is diverted 

from control device to bypass or bypass to control device. 

(c) Changing from a group 1 controlled or uncontrolled 

furnace to a group 2 furnace. An owner or operator wishing to 

change operating modes must conduct additional performance tests 

to demonstrate to the delegated regulatory authority that 

compliance can be achieved under group 1 mode and establish the 

number of cycles of operation with clean charge and no reactive 

flux addition necessary to elapse before changing to group 2 

mode. Operating parameters relevant to group 1 operation must be 

established during the performance test. 
Page 201 of 236

(1) Operators of major sources must conduct additional 

performance tests for PM, HCl, HF and D/F, according to the 

procedures in §63.1512. Controlled group 1 furnaces must conduct 

performance tests with the capture system and control device 

operating normally. Performance tests must be repeated at least 

once every 5 years to demonstrate compliance for each operating 

mode.

(i) The performance tests must be conducted with scrap 

containing the highest level of contamination expected to be 

processed, at the highest throughput expected to be processed 

and using the highest rate of reactive flux expected to be 

injected in controlled mode.

(ii) Parameters for throughput, capture, flux rate, and 

lime injection must be established during these tests.

(iii) The emission factors for this mode of operation, for 

use in the demonstration of compliance with the emission limits 

for SAPUs specified in §63.1505(k) must be determined.

(2) While in compliance with the operating requirements of 

§63.1506(o) for group 2 furnaces, operators of major sources 

must conduct additional performance tests for PM, HCl, HF and 

D/F, according to the procedures in §63.1512(e) without 

operating a control device. Performance tests must be repeated 

at least once every 5 years to demonstrate compliance for each 

operating mode.
Page 202 of 236

(i) Testing under this paragraph may be conducted at any 

time after the furnace has completed 1 or more charge-to-tap 

cycles, or 24 operating hours with clean charge, and without 

reactive flux addition.

(ii) Testing under this paragraph must be conducted with 

furnace emissions captured in accordance with the provisions of 

§63.1506(c) and directed to the stack or vent tested.

(iii) Owners or operators must demonstrate that emissions 

are no greater than:

(A) 1.5 μg D/F (TEQ) per ton of feed/charge,

(B) 0.04 lb HCl or HF per ton of feed/charge, and

(C) 0.04 lb PM per ton of feed/charge.

(iv) The number of charge-to-tap cycles, or operating hours 

elapsed before the group 2 furnace performance tests were 

conducted is established as an operating parameter to be met 

before changing to group 2 mode.

(3) Operators of area sources must conduct an additional

performance test for D/F, according to the procedures in 

§63.1512. Controlled group 1 furnaces must conduct performance 

tests with the capture system and control device operating 

normally.

(i) The performance test must be conducted with the scrap 

containing the highest level of contamination expected to be 

processed, at the highest throughput expected to be processed 
Page 203 of 236

and using the highest rate of reactive flux expected to be 

injected in group 1 mode.

(ii) Parameters for throughput, flux rate, and lime 

injection must be established during these tests.

(iii) If the furnace is equipped with a control device 

parameter(s) for capture must be established.

(iv) The D/F emission factor for this mode of operation, 

for use in the demonstration of compliance with the emission 

limits for SAPUs specified in §63.1505(k) must be determined.

(4) While in compliance with the operating standards of 

§63.1506(o) for group 2 furnaces, operators of area sources must 

conduct an additional performance test for D/F, according to the 

procedures in §63.1512(e), without operating a control device.

(i) Testing under this paragraph may be conducted at any 

time after the furnace has completed 1 or more charge-to-tap 

cycles, or 24 operating hours with clean charge, and without 

reactive flux addition.

(ii) Testing under this paragraph must be conducted with 

furnace emissions captured in accordance with the provisions of 

§63.1506(c) and directed to the stack or vent tested.

(iii) Owners or operators must demonstrate that emissions 

are no greater than 1.5 μg D/F (TEQ) per ton of feed/charge.

(iv) The number of charge-to-tap cycles, or operating hours 

elapsed before the group 2 furnace performance tests were 
Page 204 of 236

conducted is established as an operating parameter to be met 

before changing to group 2 mode.

(5) To change modes of operation from a group 1 furnace to 

a group 2 furnace, the owner or operator must 

(i) discontinue addition of other than clean charge;

(ii) discontinue addition of reactive flux;

(iii) change the label on the furnace to reflect group 2 

operation;

(iv) and if the furnace is equipped with a control device, 

allow the number of cycles of operation established in paragraph 

(c) of this section to elapse before turning off the control 

device or diverting emissions from the control device. In 

addition control device parameters related to lime addition, 

capture, and inlet temperature must be maintained during this 

period.

(6) To change mode of operation from a group 2 furnace to 

group 1 furnace, the owner or operator must change the label to 

reflect group 1 operation. If a control device is required for 

group 1 operation, the owner or operator must direct the 

emissions to the control device and maintain control device 

parameters related to lime addition, capture, and inlet 

temperature.

(d) Changing from a group 1 controlled or uncontrolled 

furnace to group 2 furnace, for tilting reverberatory furnaces 
Page 205 of 236

capable of completely removing furnace contents between batches. 

An owner or operator of a tilting reverberatory furnace capable 

of completely removing furnace contents between batches, wishing 

to change operating modes, must conduct additional performance 

tests to demonstrate that compliance can be achieved under group 

1 mode. Operating parameters relevant to group 1 operation must 

be established during the performance test. 

(1) Operators of major sources must conduct additional

performance tests for PM, HCl, HF and D/F, according to the 

procedures in §63.1512. Controlled group 1 furnaces must conduct 

performance tests with the capture system and control device 

operating normally. The performance tests must be conducted with 

the scrap containing the highest level of contamination expected 

to be processed, at the highest throughput expected to be 

processed and using the highest rate of reactive flux expected 

to be injected in controlled mode. Performance tests must be 

repeated at least once every 5 years to demonstrate compliance 

for each operating mode.

(i) Parameters for throughput, capture, flux rate, and lime 

injection must be established during these tests.

(ii) The emission factors for this mode of operation, for 

use in the demonstration of compliance with the emission limits 

for SAPUs specified in §63.1505(k) must be determined.
Page 206 of 236

(2) Operators of area sources must conduct an additional

performance test for D/F, according to the procedures in 

§63.1512. Operators of controlled group 1 furnaces must conduct 

performance tests with the capture system and control device 

operating normally. Performance tests must be repeated at least 

once every 5 years to demonstrate compliance for each operating 

mode.

(i) The performance test must be conducted with the scrap 

containing the highest level of contamination expected to be 

processed, at the highest throughput expected to be processed 

and using the highest rate of reactive flux injection expected 

in group 1 mode.

(ii) Parameters for throughput, flux rate, and lime 

injection must be established during these tests.

(iii) If the furnace is equipped with a control device 

parameter(s) for capture must be established.

(iv) The D/F emission factor for this mode of operation, 

for use in the demonstration of compliance with the emission 

limits for SAPUs specified in §63.1505(k) must be determined.

(3) To change modes from group 1 to group 2 the operator 

must:

(i) Completely remove all aluminum from the furnace;

(ii) Change the furnace label;

(iii) Use only clean charge; and
Page 207 of 236

(iv) Use no reactive flux;

(4) To change modes from group 2 to group 1 the owner or 

operator must, before charging other than clean charge and 

before adding reactive flux to the furnace;

(i) Change the label on the furnace to reflect group 1 

operation,

(ii) Direct the furnace emissions to the control device, if 

any, and,

(iii) Begin lime addition to the control device, if any.

(5) In addition to the recordkeeping requirements of 

§63.1517, the owner or operator must maintain records of the 

nature of each mode change (group 1 to group 2, or group 2 to 

group 1), the time the change is initiated, and, if the furnace 

is equipped with a control device, the time the exhaust gas is 

diverted from control device to bypass or bypass to control 

device. 

(e) Frequency of changing furnace operating mode. Changing

furnace operating mode and reversion to the previous mode, as 

provided in paragraphs (a) through (d) of this section may not 

be done more frequently than once every 6 months, except that 

controlled furnaces may change operating modes (and revert to 

prechange operating mode) without restriction on frequency, when 

the air pollution control device must be shut down for planned 

maintenance.
Page 208 of 236

* * * * *

12. Section 63.1515 is amended by removing paragraph (b)(10).

13. Section 63.1516 is amended by: 

a. By removing and reserving paragraph (a); 

b. By revising paragraph (b);

c. By removing and reserving paragraph (b)(1)(v);

d. By revising paragraph (b)(2)(iii);

e. By adding paragraph (b)(3); 

f. By revising paragraph (c); and

g. By adding paragraph(d)to read as follows:

§63.1516 Reports.

(a) [Reserved]

(b) Excess emissions/summary report. The owner or operator 

of a major or area source must submit semiannual reports 

according to the requirements in §63.10(e)(3). Except, the owner 

or operator must submit the semiannual reports within 60 days 

after the end of each 6-month period instead of within 30 days 

after the calendar half as specified in §63.10(e)(3)(v). When no 

deviations of parameters have occurred, the owner or operator 

must submit a report stating that no excess emissions occurred 

during the reporting period.

* * * * *

(2) * * *
Page 209 of 236

(iii) For each sidewell group 1 furnace with add-on air 

pollution control devices: “Each furnace was operated such that 

the level of molten metal remained above the top of the passage 

between the sidewell and hearth during reactive fluxing, and 

reactive flux, except for cover flux, was added only to the 

sidewell or to a furnace hearth equipped with an add-on air 

pollution control device for PM, HCl, HF and D/F emissions 

during this reporting period.”

* * * * *

(3) * * *

(i) Within 60 days after the date of completing each 

performance test (defined in §63.2) as required by this subpart 

you must transmit the results of the performance tests required 

by this subpart to EPA’s WebFIRE database by using the 

Compliance and Emissions Data Reporting Interface (CEDRI) that 

is accessed through EPA’s Central Data Exchange 

(CDX)(www.epa.gov/cdx). Performance test data must be submitted 

in the file format generated through use of EPA’s Electronic 

Reporting Tool (ERT) (see 

http://www.epa.gov/ttn/chief/ert/index.html). Only data 

collected using test methods on the ERT website are subject to 

this requirement for submitting reports electronically to 

WebFIRE. Owners or operators who claim that some of the 

information being submitted for performance tests is 
Page 210 of 236

confidential business information (CBI) must submit a complete 

ERT file including information claimed to be CBI on a compact 

disk or other commonly used electronic storage media (including, 

but not limited to, flash drives) to EPA. The electronic media 

must be clearly marked as CBI and mailed to U.S. EPA/OAPQS/CORE 

CBI Office, Attention: WebFIRE Administrator, MD C404-02, 4930 

Old Page Rd., Durham, NC 27703. The same ERT file with the CBI 

omitted must be submitted to EPA via CDX as described earlier in 

this paragraph. At the discretion of the delegated authority, 

you must also submit these reports, including the confidential 

business information, to the delegated authority in the format 

specified by the delegated authority.

(ii) All reports required by this subpart not subject to 

the requirements in paragraphs (1)(i) and (ii) of this section 

must be sent to the Administrator at the appropriate address 

listed in §63.13. The Administrator or the delegated authority 

may request a report in any form suitable for the specific case 

(e.g., by commonly used electronic media such as Excel 

spreadsheet, on CD or hard copy). The Administrator retains the 

right to require submittal of reports subject to paragraph 

(1)(i) and (ii) of this section in paper format.

(c) Annual compliance certifications. For the purpose of 

annual certifications of compliance required by 40 CFR part 70 

or 71, the owner or operator of a major or area source subject 
Page 211 of 236

to this subpart must certify continuing compliance based upon, 

but not limited to, the following conditions:

* * * * *

(d) If there was a malfunction during the reporting period, 

the owner or operator must submit a report that includes 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 

§§63.1506(a)(5) and 63.1520(a)(8), including actions taken to 

correct a malfunction.

* * * * *

14. Section 63.1517 is amended by: 

a. By revising paragraph (b)(16)(i); 

b. By adding paragraph (b)(18); and

c. By adding paragraph (c)to read as follows:

§63.1517 Records.

* * * * *

(b) * * *

(16) * * *

(i) [Reserved};

* * * * *
Page 212 of 236

(18) For each malfunction for which the owner or operator 

chooses to claim coverage under the affirmative defense 

provisions, the owner or operator must maintain the following 

records;

(i) Records of the occurrence and duration of each 

malfunction of operation (i.e., process equipment) or the air 

pollution control equipment and monitoring equipment.

(ii) Records of actions taken during periods of malfunction 

to minimize emissions in accordance with §§63.1506(a)(5) and 

63.1520(a)(8), including corrective actions to restore 

malfunctioning process and air pollution control and monitoring 

equipment to its normal or usual manner of operation.

(c) All reports required by this subpart not subject to the 

requirements in paragraph (b) of this section must be sent to 

the Administrator at the appropriate address listed in §63.13. 

If acceptable to both the Administrator and the owner or 

operator of a source, these reports may be submitted on 

electronic media. The Administrator retains the right to require 

submittal of reports subject to paragraph (b) of this section in 

paper format.

* * * * *

15. Section 63.1520 is revised to read as follows: 

§63.1520 Affirmative defense for violation of emission limit 

during malfunction.
Page 213 of 236

In response to an action to enforce the standards set forth 

in this subpart, you may assert an affirmative defense to a 

claim for civil penalties for violations of such standards that 

are caused by malfunction, as defined at §63.2. Appropriate 

penalties may be assessed, however, if you fail to meet your 

burden of proving all of the requirements in the affirmative 

defense. The affirmative defense shall not be available for 

claims for injunctive relief.

(a) To establish the affirmative defense in any action to 

enforce such a limit, 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, 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.

(iv) Were not part of a recurring pattern indicative of 

inadequate design, operation, or maintenance; and
Page 214 of 236

(2) Repairs were made as expeditiously as possible when the 

applicable emission limitations were being exceeded. Off-shift 

and overtime labor were used, to the extent practicable to make 

these repairs; and

(3) The frequency, amount and duration of the excess 

emissions (including any bypass) were minimized to the maximum 

extent practicable during periods of such emissions; and

(4) If the excess emissions resulted from a bypass of 

control equipment or a process, then the bypass was unavoidable 

to prevent loss of life, 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, consistent with safety and good 

air pollution control practices; 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 affected source was operated in a 

manner consistent with good practices for minimizing emissions; 

and
Page 215 of 236

(9) A written root cause analysis has been prepared, the 

purpose of which is to determine, correct, and eliminate the 

primary causes of the malfunction and the excess emissions 

resulting from the malfunction event at issue. The analysis 

shall also specify, using best monitoring methods and 

engineering judgment, the amount of excess emissions that were 

the result of the malfunction.

(b) Reports. The owner or operator seeking to assert an 

affirmative defense shall submit a written report to the 

Administrator within 45 days of the initial occurrence of the 

violation of the standards in this subpart, which may be the end 

of any applicable averaging period, to demonstrate, with all 

necessary supporting documentation, that it has met the 

requirements set forth in paragraph (a) of this section. The 

owner or operator may seek an extension of this deadline for up 

to 30 additional days by submitting a written request to the 

Administrator before the expiration of the 45 day period. Until 

a request for an extension has been approved by the 

Administrator, the owner or operator is subject to the 

requirement to submit such report within 45 days of the initial 

occurrence of the violation.

* * * * *

16. Table 1 to Subpart RRR of part 63 is amended to read as 

follows:
Page 216 of 236

Table 1 to Subpart RRR – Emission standards for New and Existing 

Affected Sources 

Affected source/Emission 

unit

Pollutant Limit Units

All new and existing 

affected sources and 

emission units that are 

controlled with a PM addon control device and that 

choose to monitor with a 

COM; and all new and 

existing aluminum scrap 

shredders that choose to 

monitor with a COM or to 

monitor visible emissions

Opacity 10 Percent

New and existing aluminum 

scrap shredder

PM 0.01 Gr/dscf

New and existing thermal 

chip dryer

THC 0.8 lb/ton of feed

D/Fa 2.5 ug TEQ/Mg of feed

New and existing scrap 

dryer/delacquering 

kiln/decoating kiln

or

PM 0.08 lb/ton of feed

HCl 0.8 lb/ton of feed

THC 0.06 lb/ton of feed

D/Fb 0.25 ug TEQ/Mg of feed

Alternative limits if 

afterburner has a design 

residence time of at least 

1 second and operates at a 

temperature of at least 

1400 F

PM 0.3 lb/ton of feed

HCl 1.5 lb/ton of feed

THC 0.2 lb/ton of feed

D/Fa 5 ug TEQ/Mg of feed

New or existing sweat 

furnace

D/Fa 0.8 ng TEQ/dscm @ 11% 

O2b

New or existing dross-only 

furnace

PM 0.3 lb/ton of feed

New or existing in-line 

fluxer 

HCL 0.04 lb/ton of feed

PM 0.01 lb/ton of feed

New and existing in-line 

fluxer with no reactive 

fluxing

No 

limit

work practice: no 

reactive fluxing
Page 217 of 236

New and existing rotary 

dross cooler

PM 0.04 gr/dscf

New and existing clean 

furnace (Group 2)

No 

limit

Work practices: 

clean charge only 

and no reactive 

fluxing

New and existing group 1 

melting/holding furnace 

(processing only clean 

charge)c

PM 0.8 lb/ton of feed

HCL 0.4 lb/ton of feed

HF 0.4 lb/ton of feed

or

10 percent of the HCl

upstream of the addon control device

New and existing group 1 

furnacec

PM 0.4 lb/ton of feed

HCL 0.4 lb/ton of feed

HF 0.4 lb/ton of feed

or

10 percent of the HCl 

upstream of the addon control device

D/Fb 15 ug/TEQ/Mg of feed

New and existing group 1 

furnace with clean charge 

onlyc

PM 0.4 lb/ton of feed

HCL 0.4 lb/ton of feed

HF 0.4 lb/ton of feed

or

10 percent of the HCl

upstream of the addon control device

D/Fa No 

limit

Clean charge only

New and existing secondary 

aluminum processing unita,d

(consists of all existing 

group 1 furnaces and 

existing in-line flux 

boxes at the facility, or 

all simultaneously 

constructed new group 1 

PMe

 

 

(Eq. 1)

T

L T

L n

i 1

ti

n

i 1

ti ti

C

PM

PM 










Page 218 of 236

furnaces and new in-lie 

fluxers)

HCl or HFf

 

 

(Eq. 2)

T

L T

L n

i 1

ti

n

i 1

tiHCl/HF ti

cHCl/HF













D/Fg

 

 

(Eq. 3)

T

L T

L n

i 1

ti

n

i 1

tiD/F ti

cD/F













a D/F limit applies to a unit at a major or area source.

b Sweat furnaces equipped with afterburners meeting the specifications 

of §63.1505(f)(1) are not required to conduct a performance test.

d These limits are also used to calculate the limits applicable to 

secondary aluminum processing units.

d Equation definitions: LiPM = the PM emission limit for individual 

emission unit i in the secondary aluminum processing unit [kg/Mg 

(lb/ton) of feed]; Ti = the feed rate for individual emission unit i in 

the secondary aluminum processing unit; LtPM = the overall PM emission 

limit for the secondary aluminum processing unit [kg/Mg (lb/Ton of 

feed)]; LiHCL/HF = the HCL or HF emission limit for individual emission 

unit i in the secondary aluminum processing unit [kg/Mg (lb/Ton) of 

feed]; LtHCl/HF = the overall HCl or HF emission limit for the secondary 

aluminum processing unit [kg/Mg (lb/ton) of feed]; LiD/F = the D/F 

emission limit for individual emission unit i [μg TEQ/Mg (gr TEQ/ton) 

of feed]; LtD/F = the overall D/F emission limit for the secondary 

aluminum processing unit [μg TEQ/Mg (gr TEQ/Ton) of feed]; n = the 

number of units in the secondary aluminum processing unit. (Need to 

check. These are slightly different that what is in the text of the 

rule)

e In-line fluxers using no reactive flux materials cannot be included 

in this calculation since they are not subject to the PM limit.

f In-line fluxers using no reactive flux materials cannot be included 

in this calculation since they are not subject to the HCL and HF

limits.

g Clean charge furnaces cannot be included in this calculation since 

they are not subject to the D/F limit.

* * * * *

17. Table 2 to Subpart RRR of part 63 is amended by:

a. Revising the entry All affected sources and emission units 

with an add-on air pollution control device;
Page 219 of 236

b. Revising the entry Scrap dryer/delacquering kiln/decoating 

kiln with afterburner and lime-injected fabric filter;

c. Revising the entry In-line fluxer with lime-injected fabric 

filter (including those that are part of a secondary aluminum 

processing unit);

d. Revising entry Group 1 furnace with lime-injected fabric 

filter (including those that are part of a secondary of aluminum 

processing unit);

e. Adding the entry Thermal chip dryer, scrap 

dryer/delacquering kiln/decoating kiln, sweat furnace, dross-only 

furnace, and group 1 furnace; and

f. Adding footnote d to Table 2 to read as follows:

Table 2 to Subpart RRR of Part 63—Summary of Operating 

Requirements for New and Existing Affected Sources and Emission 

Units

Affected 

source/emission unit

Monitor 

type/operation/process

Operating 

requirements

 * * * * * * *

All affected sources 

and emission units 

with an add-on air 

pollution control 

device

Emission capture and 

collection system

Design and install 

in accordance with 

Industrial 

Ventilation: A 

Handbook of 

Recommended 

Practice, 23rd or 

27th edition; 

operate in 

accordance with 

OM&M plan.b
Page 220 of 236

 * * * * * * *

Scrap 

dryer/delacquering 

kiln/decoating kiln 

with afterburner and 

lime-injected fabric 

filter

Afterburner operating 

temperature

Maintain average 

temperature for 

each 3-hr period 

at or above 

average operating 

temperature during 

the performance 

test.

 Afterburner operation Operate in 

accordance with 

OM&M plan.b

 Bag leak detector or Initiate 

corrective action 

within 1-hr of 

alarm and complete 

in accordance with 

the OM&M plan;b

operate such that 

alarm does not 

sound more than 5% 

of operating time 

in 6-month period.

 COM Initiate 

corrective action 

within 1-hr of a 

6-minute average 

opacity reading of 

5% or more and 

complete in 

accordance with 

the OM&M plan.b

 Fabric filter inlet 

temperature

Maintain average 

fabric filter 

inlet temperature 

for each 3-hr 

period at or below 

average 

temperature during 

the performance 

test +14 °C (+25 

°F).

 Lime injection rate Maintain free-
Page 221 of 236

flowing lime in 

the feed hopper or 

silo at all times 

for continuous 

injection systems; 

maintain feeder 

setting at level 

established during 

the performance 

test for 

continuous 

injection systems.

 * * * * * * *

In-line fluxer with 

lime-injected fabric 

filter (including 

those that are part 

of a secondary 

aluminum processing 

unit)

Bag leak detector or Initiate 

corrective action 

within 1-hr of 

alarm and complete 

in accordance with 

the OM&M plan;b

operate such that 

alarm does not 

sound more than 5% 

of operating time 

in 6-month period.

 COM Initiate 

corrective action 

within 1-hr of a 

6-minute average 

opacity reading of 

5% or more and 

complete in 

accordance with 

the OM&M plan.b

 Lime injection rate Maintain freeflowing lime in 

the feed hopper or 

silo at all times 

for continuous 

injection systems; 

maintain feeder 

setting at level 

established during 

performance test 

for continuous 
Page 222 of 236

injection systems.

 Reactive flux injection 

rate

Maintain reactive 

flux injection 

rate at or below 

rate used during 

the performance 

test for each 

operating cycle or 

time period used 

in the performance 

test.

 * * * * * * *

Group 1 furnace with 

lime-injected fabric 

filter (including 

those that are part 

of a secondary of 

aluminum processing 

unit).

Bag leak detector or Initiate 

corrective action 

within 1-hr of 

alarm; operate 

such that alarm 

does not sound 

more than 5% of 

operating time in 

6-month period; 

complete 

corrective action 

in accordance with 

the OM&M plan.b

 COM Initiate 

corrective action 

within 1-hr of a 

6-minute average 

opacity reading of 

5% or more; 

complete 

corrective action 

in accordance with 

the OM&M plan.b

 Fabric filter inlet 

temperature

Maintain average 

fabric filter 

inlet temperature 

for each 3-hour 

period at or below 

average 

temperature during 

the performance 
Page 223 of 236

test +14 °C (+25 

°F).

 Reactive flux injection 

rate

Maintain reactive 

flux injection 

rate (kg/Mg) 

(lb/ton) at or 

below rate used 

during the 

performance test 

for each furnace 

cycle.

 Lime injection rate Maintain freeflowing lime in 

the feed hopper or 

silo at all times 

for continuous 

injection systems; 

maintain feeder 

setting at level 

established at 

performance test 

for continuous 

injection systems.

 Maintain molten aluminum 

level

Operate sidewell 

furnaces such that 

the level of 

molten metal is 

above the top of 

the passage 

between sidewell 

and hearth during 

reactive flux 

injection, unless 

the hearth is also 

controlled.

 Fluxing in sidewell 

furnace hearth

Add reactive flux 

only to the 

sidewell of the 

furnace unless the 

hearth is also 

controlled.

 * * * * * * *
Page 224 of 236

Furnaces that will be 

idle for at least 24 

hours and will burn clean 

fuel only, will not 

receive new charge, flux 

or alloying material

Associated fans, 

hoods and APCD may 

be temporarily 

turned off.

Before charging 

resumes, all 

associated fans, 

hoods and APCD 

must be turned on 

and operated 

continuously.

 * * * * * * *

dAPCD – Air pollution control device.

* * * * *

18. Table 3 to Subpart RRR of part 63 is amended by:

a. Revising the entry All affected sources and emission units 

with an add-on air pollution control device;

b. Revising the entry Aluminum scrap shredder with fabric 

filter;

c. Revising the entry Scrap dryer/delacquering kiln/decoating 

kiln with afterburner and lime-injected fabric filter;

d. Revising entry Dross-only furnace with fabric filter;

e. Revising the entry Rotary dross cooler with fabric filter;

f. Revising the entry In-line fluxer with lime-injected fabric 

filter;

g. Revising the entry Group 1 furnace with lime-injected fabric 

filter;

h. Removing footnote c to Table 3; and 
Page 225 of 236

i. Revising footnote d to Table 3 to read as follows:

Table 3 to Subpart RRR of Part 63—Summary of Monitoring 

Requirements for New and Existing Affected Sources and Emission 

Units

Affected 

source/Emission unit

Monitor 

type/Operation/Process

Monitoring 

requirements

 * * * * * * *

All affected sources 

and emission units 

with an add-on air 

pollution control 

device

Emission capture and 

collection system

Annual inspection of 

all emission capture, 

collection, and 

transport systems to 

ensure that systems 

continue to operate 

in accordance with 

ACGIH standards.

Inspection includes 

volumetric flow rate 

measurements.

 * * * * * * *

Aluminum scrap 

shredder with fabric 

filter

Bag leak detector or Install and operate 

in accordance with 

manufacturer’s 

operating 

instructions.

 COM or Design and install in 

accordance with PS–1; 

collect data in 

accordance with 

subpart A of 40 CFR 

part 63; determine 

and record 6-minute 

block averages.

 VE Conduct and record 

results of 30-minute 

daily test in 

accordance with 
Page 226 of 236

Method 9.

 * * * * * * *

Scrap 

dryer/delacquering 

kiln/decoating kiln 

with afterburner and 

lime-injected fabric 

filter

Afterburner operating 

temperature.

Continuous 

measurement device to 

meet specifications 

in §63.1510(g)(1); 

record temperature 

for each 15-minute 

block; determine and 

record 3-hr block 

averages.

 Afterburner operation Annual inspection of 

afterburner internal 

parts; complete 

repairs in accordance 

with the OM&M plan.

 Bag leak detector or Install and operate 

in accordance with 

manufacturer’s 

operating 

instructions.

 COM Design and Install in 

accordance with PS–1; 

collect data in 

accordance with 

subpart A of 40 CFR 

part 63; determine 

and record 6-minute 

block averages.

 Lime injection rate For continuous 

injection systems, 

inspect each feed 

hopper or silo every 

8 hours to verify 

that lime is free 

flowing; record 

results of each 

inspection. If 

blockage occurs, 

inspect every 4 hours 

for 3 days; return to 

8-hour inspections if 

corrective action 
Page 227 of 236

results in no further 

blockage during 3-day 

period, record feeder 

setting daily.

Verify monthly that 

lime injection rate 

is no less than 90 

percent of the rate 

used during the 

compliance 

demonstration test.

 Fabric filter inlet 

temperature.

Continuous 

measurement device to 

meet specifications 

in §63.1510(h)(2); 

record temperatures 

in 15-minute block 

averages; determine 

and record 3-hr block 

averages.

 * * * * * * *

Dross-only furnace 

with fabric filter

Bag leak detector or Install and operate 

in accordance with 

manufacturer’s 

operating 

instructions.

 COM Design and install in 

accordance with PS–1; 

collect data in 

accordance with 

subpart A of 40 CFR 

part 63; determine 

and record 6-minute 

block averages.

 Feed/charge material Record identity of 

each feed/charge; 

certify charge 

materials every 6 

months.

 * * * * * * *

Rotary dross cooler 

with fabric filter

Bag leak detector or Install and operate 

in accordance with 
Page 228 of 236

manufacturer’s 

operating 

instructions.

 COM Design and install in 

accordance with PS–1; 

collect data in 

accordance with 

subpart A of 40 CFR 

part 63; determine 

and record 6-minute 

block averages.

 * * * * * * *

In-line fluxer with 

lime-injected fabric 

filter

Bag leak detector or Install and operate 

in accordance with 

manufacturer’s 

operating 

instructions.

 COM Design and install in 

accordance with PS–1; 

collect data in 

accordance with 

subpart A of 40 CFR 

part 63; determine 

and record 6-minute 

block averages

 Reactive flux 

injection rate

Weight measurement 

device accuracy of 

±1%b; calibrate 

according to 

manufacturer's 

specifications or at 

least once every 6 

months; record time, 

weight and type of 

reactive flux added 

or injected for each 

15-minute block 

period while reactive 

fluxing occurs; 

calculate and record 

total reactive flux 

injection rate for 

each operating cycle 
Page 229 of 236

or time period used 

in performance test; 

or

Alternative flux 

injection rate 

determination 

procedure per 

§63.1510(j)(5). For 

solid flux added 

intermittently, 

record the amount 

added for each 

operating cycle or 

time period used in 

the performance test.

 Lime injection rate For continuous 

injection systems, 

record feeder setting 

daily and inspect 

each feed hopper or 

silo every 8 hrs to 

verify that lime is 

free-flowing; record 

results of each 

inspection. If 

blockage occurs, 

inspect every 4 hrs 

for 3 days; return to 

8-hour inspections if 

corrective action 

results in no further 

blockage during 3-day 

period.d

Verify monthly that 

the lime injection 

rate is no less than 

90 percent of the 

rate used during the 

compliance 

demonstration test.

 * * * * * * *

Group 1 furnace with 

lime-injected fabric 

filter

Bag leak detector or Install and operate 

in accordance with 

manufacturer’s 

operating 
Page 230 of 236

instructions.

 COM Design and install in 

accordance with PS–1; 

collect data in 

accordance with 

subpart A of 40 part 

CFR 63; determine and 

record 6-minute block 

averages.

 Lime injection rate For continuous 

injection systems, 

record feeder setting 

daily and inspect 

each feed hopper or 

silo every 8 hours to 

verify that lime is 

free-flowing; record 

results of each 

inspection. If 

blockage occurs, 

inspect every 4 hours 

for 3 days; return to 

8-hour inspections if 

corrective action 

results in no further 

blockage during 3-day 

period.d

Verify monthly that 

the lime injection 

rate is no less than 

90 percent of the 

rate used during the 

compliance 

demonstration test.

 Reactive flux 

injection rate

Weight measurement 

device accuracy of 

±1%b; calibrate every 

3 months; record 

weight and type of 

reactive flux added 

or injected for each 

15-minute block 

period while reactive 

fluxing occurs; 

calculate and record 
Page 231 of 236

total reactive flux 

injection rate for 

each operating cycle 

or time period used 

in performance test; 

or Alternative flux 

injection rate 

determination 

procedure per 

§63.1510(j)(5). For 

solid flux added

intermittently, 

record the amount 

added for each 

operating cycle or 

time period used in 

the performance test.

 Fabric filter inlet 

temperature

Continuous 

measurement device to 

meet specifications 

in §63.1510(h)(2); 

record temperatures 

in 15-minute block 

averages; determine 

and record 3-hour 

block averages.

 Maintain molten 

aluminum level in 

sidewell furnace

Maintain aluminum 

level operating log; 

certify every 6 

months. If visual 

inspection of molten 

metal level is not 

possible, use 

physical measurement 

methods.

 * * * * * * *

Group 1 furnace 

without add-on 

controls

Fluxing in sidewell 

furnace hearth

Maintain flux 

addition operating 

log; certify every 6 

months.

 Reactive flux 

injection rate

Weight measurement 

device accuracy of 

+1%b; calibrate 
Page 232 of 236

according to 

manufacturers 

specifications or at 

least once every six 

months; record weight 

and type of reactive 

flux added or 

injected for each 15-

minute block period 

while reactive 

fluxing occurs; 

calculate and record 

total reactive flux 

injection rate for 

each operating cycle 

or time period used 

in performance test.

For solid flux added 

intermittently, 

record the amount 

added for each 

operating cycle or 

time period used in 

the performance test.

 OM&M plan (approved by

permitting agency)

Demonstration of 

site-specific 

monitoring procedures 

to provide data and 

show correlation of 

emissions across the 

range of charge and 

flux materials and 

furnace operating 

parameters.

 Feed material 

(melting/holding 

furnace)

Record type of 

permissible 

feed/charge material; 

certify charge 

materials every 6 

months.

 * * * * * * *

c Permitting agency may approve other alternatives including load cells for 

lime hopper weight, sensors for carrier gas pressure, or HCl monitoring 

devices at fabric filter outlet.
Page 233 of 236

* * * * *

19. Appendix A to Subpart RRR of part 63 is amended by:

a. Removing entry 63.6(e)(1)-(2);

b. Adding entries 63.6(e)(1)(i) and 63.6(e)(1)ii);

c. Adding entry 63.6(e)(2);

d. Revising entry 63.6(e)(3)

e. Removing entry 63.6(f);

f. Adding entries 63.6(f)(1) and 63.6(f)(2);

g. Removing entries 63.6((h);

h. Adding entries 63.6(h)(1) and 63.6(h)(2);

i. Removing entries 63.7((e);

j. Adding entries 63.7(e)(1) and 63.7(e)(2);

k. Removing entries 63.8((c)(1)-(3);

l. Adding entries 63.8(c)(1)(i), 63.8(c)(1)(ii), 

63.8(c)(1)(iii), 63.8(c)(1)(iv) and 63.7(e)(2)-(3);

m. Removing entries 63.10((b);

n. Adding entries 63.10(b)(1), 63.10(b)(2)(i),(ii), (iv) 

and (v), and 63.10(b)(2)(iii;

o. Revising entry 63.10(c)(10)-(13); 

p. Revising entry 63.10(d)(4)-(5); and

q. Revising entries 63.14 to read as follows:

Appendix A to Subpart RRR of Part 63 – Applicability of General 

Provisions 40 CFR 63, Subpart RRR

Citation Requirement Applies to RRR Comment
Page 234 of 236

 * * * * * * *

63.6(e)(1)(i) No. See §63.1506(a)(5) 

for general duty 

requirement. Any 

other cross

reference to 

§63.6(3)(1)(i) in 

any other general 

provision 

incorporated by 

reference shall be 

treated as a cross 

reference to 

§63.1506(a)(5).

63.6(e)(1)(ii) No.

 * * * * * * *

63.6(e)(2)) Yes.

 * * * * * * *

§63.6(e)(3) Startup, Shutdown 

Plan

No.

 * * * * * * *

§63.6(f)(1) Compliance with 

Emission Standards

No.

§63.6(f)(2) Compliance with 

Emission Standards

Yes.

 * * * * * * *

§63.6(h)(1) Compliance with 

Opacity/VE 

Standards

No.

§63.6(h)(2)- Compliance with 

Opacity/VE 

Standards

Yes.

 * * * * * * *

§63.7(e)(1) Conduct of Tests No. See 63.1511(a).

§63.7(e)(2) Conduct of Tests Yes.
Page 235 of 236

 * * * * * * *

63.8(c)(1)(i) No See 63.1506(a)(5)

for general duty 

requirement.

63.8(c)(1)(ii) Yes.

§63.8(c)(1)(iii) CMS Operation and 

Maintenance

NO.

 * * * * * * *

§63.8(d)(3) Quality Control Yes, except for 

last sentence, 

which refers to 

an SSM plan. 

SSM plans are 

not required.

 * * * * * * *

§63.10(b)(1) General 

Requirements

Yes See 63.1517

includes additional 

requirements

 * * * * * * *

§63.10(b)(2)(i), 

(ii), (iv) and (v)

General 

Requirements

No See 63.1517(b)(18)

for recordkeeping 

of occurrence and 

duration of 

malfunctions and 

recordkeeping of 

actions taken 

during malfunction

§63.10(b)(2)(iii)

and (vi) to (ix)

General 

Requirements

Yes See 63.1517 

includes additional 

requirements

 * * * * * * *

§63.10(c)(10)-(11) No. See 63.1517(b)(18)

for recordkeeping 

of malfunctions.

 * * * * * * *

§63.10(c)(15) General 

Requirements

No
Page 236 of 236

 * * * * * * *

§63.10(d)(4)–(5) Progress 

Reports/Startup, 

Shutdown, and 

Malfunction Reports

No.

 * * * * * * *

§63.14 Incorporation by 

Reference

Yes ACGIH Industrial 

Ventilation Manual 

for 

capture/collection 

systems; and 

Interim Procedures 

for Estimating Risk 

Associated with 

Exposure to 

Mixtures of 

Chlorinated 

Dibenzofurans (CDDs 

and CDFs) and 1989 

Update 

(incorporated by 

reference in 

§63.1502).

 * * * * * * *