E.O. 12866 Secondary Aluminum Proposal 2060-AQ40 12-30-11

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:

Add work practice standards for periods of startup and shutdown for some
processes;

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 furnaces
designations;

Add rule requirements regarding testing of uncontrolled furnaces;

Add rule requirements for testing hydrogen fluoride in addition to
hydrogen chloride in furnaces that use fluorine-containing fluxes;

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-OAR-2010-0544.

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-HQ-OAR-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
EPA-HQ-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 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 CD-ROM 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. All documents in the docket are
listed in the http:// HYPERLINK "http://www.regulations.gov"
www.regulations.gov  index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, is not placed on the Internet and will be
publicly available only in hard copy. Publicly available docket
materials are available either electronically in
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: 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:

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

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

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

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:

  TOC \n \h \z \t "_Level 2-GHG Preamble,2,_Level 1-GHG Preamble,1"   
HYPERLINK \l "_Toc311142794"  I. General Information 

  HYPERLINK \l "_Toc311142795"  A. What is the statutory authority for
this action? 

  HYPERLINK \l "_Toc311142796"  B. Does this action apply to me? 

  HYPERLINK \l "_Toc311142797"  C. Where can I get a copy of this
document and other related information? 

  HYPERLINK \l "_Toc311142798"  D. What should I consider as I prepare
my comments for the EPA? 

  HYPERLINK \l "_Toc311142799"  II. Background 

  HYPERLINK \l "_Toc311142800"  A. What is this source category and how
did the MACT standard regulate its HAP emissions? 

  HYPERLINK \l "_Toc311142801"  B. What data collection activities were
conducted to support this action? 

  HYPERLINK \l "_Toc311142802"  III. Analyses Performed 

  HYPERLINK \l "_Toc311142803"  A. How did we estimate risks posed by
the source category? 

  HYPERLINK \l "_Toc311142804"  B. How did we consider the risk results
in making decisions for this proposal? 

  HYPERLINK \l "_Toc311142805"  C. How did we perform the technology
review? 

  HYPERLINK \l "_Toc311142806"  D. What other issues are we addressing
in this proposal? 

  HYPERLINK \l "_Toc311142807"  IV. Analytical Results and Proposed
Decisions 

  HYPERLINK \l "_Toc311142808"  A. What are the results of the risk
assessments? 

  HYPERLINK \l "_Toc311142809"  B. What are our proposed decisions
regarding risk acceptability and ample margin of safety? 

  HYPERLINK \l "_Toc311142810"  C. What are the results and proposed
decisions based on our technology review? 

  HYPERLINK \l "_Toc311142811"  D. What other actions are we proposing? 

  HYPERLINK \l "_Toc311142812"  E. Compliance dates 

  HYPERLINK \l "_Toc311142813"  V. Summary of Cost, Environmental, and
Economic Impacts 

  HYPERLINK \l "_Toc311142814"  A. What are the affected sources? 

  HYPERLINK \l "_Toc311142815"  B. What are the air quality impacts? 

  HYPERLINK \l "_Toc311142816"  C. What are the cost impacts? 

  HYPERLINK \l "_Toc311142817"  D. What are the economic impacts? 

  HYPERLINK \l "_Toc311142818"  E. What are the benefits? 

  HYPERLINK \l "_Toc311142819"  VI. Request for Comments 

  HYPERLINK \l "_Toc311142820"  VII. Submitting Data Corrections 

  HYPERLINK \l "_Toc311142821"  VIII. Statutory and Executive Order
Reviews 

  HYPERLINK \l "_Toc311142822"  A. Executive Order 12866: Regulatory
Planning and Review and Executive Order 13563: Improving Regulation and
Regulatory Review .

  HYPERLINK \l "_Toc311142823"  B. Paperwork Reduction Act. 

  HYPERLINK \l "_Toc311142824"  C. Regulatory Flexibility Act. 

  HYPERLINK \l "_Toc311142825"  D. Unfunded Mandates Reform Act. 

  HYPERLINK \l "_Toc311142826"  E. Executive Order 13132: Federalism. 

  HYPERLINK \l "_Toc311142827"  F. Executive Order 13175: Consultation
and Coordination with Indian Tribal Governments. 

  HYPERLINK \l "_Toc311142828"  G. Executive Order 13045: Protection of
Children from Environmental Health Risks and Safety Risks. 

  HYPERLINK \l "_Toc311142829"  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 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
technology-based standards must reflect the maximum degree of emission
reductions of HAP achievable (after considering cost, energy
requirements and non-air quality health and environmental impacts) and
are commonly referred to as maximum achievable control technology (MACT)
standards.

MACT standards must require the maximum degree of 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 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 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 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 effect 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
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: 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 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–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 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 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) 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 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 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
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, 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 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 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. 

Crushing, shredding and grinding operations are used to reduce the size
of scrap aluminum. Particulate matter (PM) and HAP metals 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 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 emits 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
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/ 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
dross-only 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, subpart RRR. The
rule was amended at 67 FR 79807, 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).  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
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

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% O2b

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

10	lb/ton of feed

lb/ton of feed

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
in-line fluxers)	PMe

 

	HClf

 

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 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
lime-injected 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 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
HAP-speciated metal and organic HAP emissions. Therefore, responses to
the nine-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. 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, 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?

	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 2010; 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

	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 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 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 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. 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
internal point locations and populations provides the basis of human
exposure calculations (Census, 2000). In addition, for each census
block, the census library includes the elevation and controlling hill
height, which are also used in dispersion calculations. A third library
of pollutant unit risk factors and other health benchmarks is used to
estimate health risks. These risk factors and health benchmarks are the
latest values recommended by the EPA for HAP and other toxic air
pollutants. These values are available at  HYPERLINK
"http://www.epa.gov/ttn/atw/toxsource/summary.html"
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
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) 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 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 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 dose-response
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://
HYPERLINK "http://www.oehha.ca.gov/air/pdf/acuterel.pdf"
www.oehha.ca.gov/air/pdf/acuterel.pdf ) is defined as “the
concentration level at or below which no adverse health effects are
anticipated for a specified exposure duration.” 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:// HYPERLINK
"http://www.epa.gov/opptintr/aegl/pubs/" www.epa.gov/opptintr/aegl/pubs/
sop.pdf), “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 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 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 ( HYPERLINK
"http://www.aiha.org/1documents/committees/ERPSOPs2006.pdf"
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.” 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 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 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. 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 one-hour 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 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 worst-case 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 response to a key
recommendation from the SAB’s peer review of the EPA’s RTR risk
assessment methodologies, 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). 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 reasonable, 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 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 HAP-emitting 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 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

	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 multiplication 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, 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. 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, 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 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.

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, 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 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). In some circumstances, the true risk could be as low as zero;
however, in other circumstances, the risk could also be greater. 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 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, e.g., factors of 10 or 3, used in the absence of
compound-specific data; where data are available, UF may also be
developed using compound-specific information. When data are limited,
more assumptions are needed and more UF are used. Thus, there may be a
greater tendency to overestimate 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
(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 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.

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 PB-HAP emissions to determine
whether a full assessment of the multipathway and environmental effects
is necessary. 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 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) of
approximately 1 in 10 thousand [i.e., 100 in 1 million]” (54 at FR
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 (75 FR
65068, October 21, 2010, and 75 FR 80220, December 21, 2010), the EPA
also presented and considered additional measures of health information,
such as estimates of the risks associated with the maximum level of
emissions which might be allowed by the current MACT standards (see,
e.g., 75 FR 65068, October 21, 2010, and 75 FR 80220, December 21,
2010). 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.

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).

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 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 non-cancer 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 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.”  

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 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 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 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 industry-supported 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 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). 

We are also proposing changes to the rule related to affirmative defense
for exceedance 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 sources and 103 area
sources were modeled due to the other sources’ lack of equipment with
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 Facilities Modeled	Maximum

Individual

Cancer Risk

(in 1 million)1	Estimated Population

at increased Risk of cancer ≥ 1 in 1 Million	Estimated Annual

Cancer

Incidence (cases per year)	Maximum

Chronic Non-cancer

TOSHI2	Worst-case Maximum Refined Screening Acute Non-cancer HQ3

	Based on Actual Emissions Level	Based on Allowable Emissions Level

	Based on Actual Emissions Level	Based on Allowable Emissions 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	0.004	-

Facility-wide Major Source	20	-	62,000	0.006	0.9	-	-

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.

	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
(handling clean charge only). 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. 

	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
0.0006 cases per year and the chronic non-cancer TOSHI value is
calculated to be 0.9.

	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 as high as 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 0.004 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 Risk
Assessment Document Appendix 4 for a more detailed discussion of
screening emission rates). Results of this worst-case screen estimate
that actual POM emissions from 20 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
effects; whereas emission levels above this worst-case screening level
only indicate the potential for multipathway-related health 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 are significant -
only that we cannot rule out the possibility that they might be
significant.

	With respect to the potential for adverse environmental effects from
non PB-HAP, we note that for both major and area 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 as high as 1 in 1 million due to actual emissions and as high
as 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
chronic or acute non-cancer health 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 worst-case screening levels. However, we note that this is
a worst-case 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 worst-case 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 risk, based on the low level of risk identified for the
source category, a facilitywide 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 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-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 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 that are based on ACI injection
technology.  

	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 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.

	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 cost-effective
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. 

	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 lime-injected 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, these technologies do not clearly reduce HAP
emissions relative to technologies that were available at the time of
promulgation of the Secondary Aluminum Production NESHAP in 2000. 

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. 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 D/F emission test data for the one operating U.S.
multichamber furnace are not lower than all other Group 1 furnaces
handling other than clean charge and are not lower than all delacquering
kiln emission test data. Based on available information it is not clear
that this technology would reduce HAP emissions relative to technologies
that are already used by other facilities in the U.S. Overall, based on
our analyses, we conclude that it would not be appropriate to require
other facilities in the U.S. to use this technology at this time.   

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 emissions reductions that can be achieved at secondary
aluminum production facilities using this technology. We therefore
conclude that catalytic filtration systems are not yet a demonstrated
technology that can be broadly applied to the secondary aluminum
production source category at this time.

We also evaluated the potential to lower D/F emissions under the
technology review by lowering the emissions limits which would likely
result in the broader use of activated carbon injection technology.
Under this analysis, we evaluated the exact 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 $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
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. After considering the costs and the
small reductions that would be achieved, we have decided not to propose
either of these options that are based on ACI injection technology under
section 112(d)(6) of the CAA.  

Overall, based on our technology review, we determined that the
developments in practices, processes and control technologies identified
do not clearly reduce emissions relative to technologies that were
available at the time of promulgation of the Secondary Aluminum
Production NESHAP in 2000. We did not identify any feasible and cost
effective options to further reduce emissions as part of technology
review. Therefore, we are not proposing any revisions to the NESHAP as
part of our technology review. Additional details regarding these
analyses can be found in the following technical document for this
action 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. 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 NESAHP in March 2000 (65 FR 15689), individual
representatives from state regulatory agencies, EPA regional offices and
industry have submitted recommendations to the Agency 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(q), 63.1520) 
Addresses vacated General Provision (GP) requirements.

Deletes references to vacated GP sections.

Adds work practices for periods of startup and shutdown for certain
affected sources. 

Adds definition for affirmative defense. Adds affirmative defense
requirements 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. Capture and Collection Requirements (63.1506(c)(1))	Requires use of
the 2003, or later, ACGIH manual. 

Requests comments on methods other than ACGIH manual to ensure capture
and collection.

4. Scrap Inspection Program for Group 1 Furnace without Add-on Air
Pollutions Control Devices (63.1510(p))	Considering a requirement to
require a scrap inspection program.

Current requirement is optional.

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 worst case 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.

10. Bale Breakers (63.1503)	Adds a definition of a bale breaker to
clarify that the 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/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.

16. Transporting metal (63.1503)	Clarifies definition of Group 2
furnaces 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 appropriated cleaning
procedures.

18. Measurements of HF in Addition to HCl (63.1503, 63.1505,
63.1511(c)(9), 63.1513)	Revises definition of HCl to account for HF;
adds definition of HF.

Revises emissions standards for HCl to include HF; combined HF and HCl
emissions limit same as HCl.

Requires EPA Method 26A for measurement of HF and HCl.

Revises compliance equations.

19. Uncontrolled furnaces that do not Comply with ACGIH Hooding
Guidelines (63.1512(e)(4))	Requires owner/operators with 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.”Industrial Ventilation: A Manual of Recommended Practice”, 23rd
Edition (63.1506(c)(1))	Allows use of the 23rd or later editions, and
takes out references to chapters 3 and 5.

21. Clarify the possible Number of SAPUs (63.1503)	Revises “SAPU”
definition to clarify there can be more than 1 new SAPU.

22. Aluminum Scrap Containing Anodizing Dyes or Sealants (63.1503)
Clarifies “clean charge” definition to exclude anodized material
coated with dyes or sealants that contain organic material.

23. Afterburner Residence Time (63.1503)	Clarifies “residence time”
definition to include refractory lined ductwork up to the control
thermocouple.

24. SAPU Feed/Charge Rate (63.1505(k))	Clarifies that daily throughput
must be used to calculate allowable emissions within the SAPU.

25. Changing Furnace Designations (63.1514)	Allows owners/operators to
switch furnace designations.

Specifies requirements for switching.

26. ACGIH Hooding Requirements	Invites comments on alternatives to the
currently required ACGIH guidelines. 

27. 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.

28. Annual Hood Inspections (63.1510(d)(2))	Clarifies that annual hood
inspections include flow rate measurements.

29. Applicability of Rule to Area Sources (63.1506(a), 63.1510(a))
Clarifies which operating, monitoring and other standards apply to area
sources.

30. Altering Parameters during Testing with New Scrap Streams
(63.1511(b)(1))	Clarifies that owners/operators can deviate from
established parametric limits during performance testing being done to
establish new parametric limits.

31. 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.



1. Startup, shutdown and malfunctions

We are proposing to amend the provisions of the subpart RRR NESHAP
regarding compliance with the emissions limits during periods of
startup, shutdown, and malfunction (SSM). These proposed revisions are
necessary to remove references in the subpart RRR NESHAP to certain
requirements of the General Provisions to part 63 regarding HAP
emissions during SSM periods. These General Provision requirements were
vacated by a recent court decision.

We are proposing to revise the subpart RRR NESAHP to require certain
affected sources to comply with work practice standards during periods
of startup and shutdown and numerical emissions limits at all other
times. Specifically, we are proposing several revisions to subpart RRR
including revising Table 1 to indicate that certain requirements of the
General Provisions pertaining to SSM do not apply. For reasons discussed
below, we are also proposing to promulgate an affirmative defense to
civil penalties for exceedances of emissions standards caused by
malfunctions, as well as criteria for establishing the affirmative
defense. These changes would go into effect upon the effective date of
the final rule.

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 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, for the reasons explained below, the
EPA is proposing different standards for startup and shutdown periods
for some types of process units. However, for other processes, for the
reasons explained below, we are not proposing different standards for
those periods.

There are some processes that are part of the secondary aluminum
production source category for which startup or shutdown has no
relevance or for which the standard is already in the form of a work
practice (e.g., scrap shredders, in-line fluxers, group 2 furnaces and
rotary dross coolers). For most units subject to the current rule,
emissions limits for PM, D/F, HCl, and THC during normal operations are
expressed using a normalized format of mass of pollutant per unit of
feed (e.g., lb/ton of feed) or charge. Because aluminum feed and
production are reduced or halted during startup and shutdown,
determining compliance with such an emission limit format without any
feed materials is mathematically unrealistic. To apply a numerical
emissions limit during startup and shutdown operations would require
that we have data not yet available to us in order to address a suitable
emissions limit format.

We considered whether performance testing and enforcement of numeric
emission limits would be practical during periods of startup and
shutdown. The EPA determined that there are a number of significant
technical challenges associated with emissions measurements of PM and
HAP emissions during periods of startup and shutdown that make
establishing and complying with numerical emissions limits technically
and economically impractical. 

The group 1 furnaces, dryers and kilns used in the secondary aluminum
process are heated during periods of startup through slow feeding of
natural gas with no scrap or other feed materials. During these periods,
many stack gas characteristics including temperature, flow rate,
pollutant and flow stratification, and stack gas molecular weight and
moisture content of the gas change far more dramatically and rapidly
than they would during normal operating conditions. An emissions tester
must account for these changing parameters with near-constant
measurements and adjustment during each test run and also conduct
multiple, sequential test runs in order to produce representative
values. The durations of these startup or shutdown periods are variable
depending on the state of the refractory or other equipment. These
periods could be on the order of 36 hours to multiple days in duration
(e.g., to cure new refractory) requiring many more than three test runs
to collect a representative measurement. During a shutdown, the period
over which process exhaust flow rate would change from full load
conditions to zero could range from less than a day to longer. Such
transient and variable conditions would make the conduct of multiple
test runs meeting the isokinetic or other proportional sampling
requirements physically problematic. 

In terms of staff scheduling, multiple test crews would have to be
on-site ready to begin testing at the beginning of a startup or shutdown
period. Further, test crews must be prepared to stop and restart
measurements to coincide with process difficulties that can occur
particularly during startup. Scheduling such testing to coincide with
the beginning of less predictable shutdown periods would require having
testing crews on-site nearly full time. These staff resource issues
would dramatically increase the cost of testing to deal with startup and
shutdown periods. 

In addition to the technical problems of collecting representative
samples in stratified stack conditions, sampling for PM, HCl, and D/F
must be isokinetic and sampling for THC concentrations must be
proportional in order to assure representative results. Maintaining
isokinetic or other proportional sampling when stack gas flows range
from zero to nearly full load conditions during either startup or
shutdown with measurement equipment commonly applied for this type of
testing would be an extremely difficult measurement challenge and very
likely lead to unacceptable test runs. 

For these technical and economic reasons, we have determined that
conducting manual emissions testing during secondary aluminum startup or
shutdown periods for dryers, kilns, sweat furnaces, dross-only furnaces
and group 1 furnaces is impracticable in the context of section
112(h)(2)(B) of the Clean Air Act. As a result, we have established a
separate work practice standard for emissions of PM, HCl, D/F, and THC
during periods of startup and shutdown for these portions of the
secondary aluminum manufacturing process. The EPA proposes in this rule
to require sources to meet a work practice standard for many processes
involved in secondary aluminum production. Work practice standards will
define the beginning and end of startup and shutdown periods and require
certain operating procedures designed to minimize emissions of THC, PM,
HCl, and D/F for each scenario anticipated. 

For purposes of this rule, startup begins upon usage of natural gas or
other clean fuel to ignite a dryer, kiln, sweat furnace, dross-only
furnace or group 1 furnace from a cold start. Under the proposed work
practice provisions for startup, the operator must engage and operate
any associated exhaust fans, capture hoods and air pollution control
devices whenever fuel is fired in the device. At the point that feed is
introduced into the dryer, kiln, sweat furnace, dross-only furnace or
group 1 furnace, startup ends and the process is in its normal operating
mode and subject to the numerical emission limits. 

Similarly for shutdown conditions, when an operator halts the
introduction of scrap or charge to and has removed all product (e.g.,
tapped a furnace) from an operating dryer, kiln, sweat furnace,
dross-only furnace or group 1 furnace, the shutdown phase has begun
during which the work practice provisions apply and the numerical
emission limits do not apply. During equipment shutdown, any associated
exhaust fans, capture hoods and air pollution control devices must be
engaged and operating until the kiln, furnace or dryer exhaust gas
temperature falls below 200ºF at which point shutdown ends.

The continued operation of the existing control devices and emission
capture systems will, in conjunction with the detailed proposed work
practices described above, be consistent with maximum achievable control
technology and will be adequate, along with all the other standards
described above, to ensure that risks will be acceptable and the rule
will provide an ample margin of safety.

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” 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 countless types of malfunctions that can occur
across all sources in the category and 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 data gathering
necessary to solve a problem. We generally defer to an 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 non-malfunctioning 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, 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 an exceedance of the relevant emission standard. (See,
e.g., State Implementation Plans: Policy Regarding Excessive Emissions
During Malfunctions, Startup, and Shutdown (Sept. 20, 1999); Policy on
Excess Emissions During Startup, Shutdown, Maintenance, and Malfunctions
(Feb. 15, 1983)). The EPA is therefore proposing to add to the final
rule an affirmative defense to civil penalties for exceedances of
emission limits that are caused by malfunctions. See 40 CFR 63.1503
(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 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 (40 CFR 22.24). The criteria ensure that the
affirmative defense is available only where the event that causes an
exceedance of the emission limit meets the narrow definition of
malfunction in 40 CFR 63.2 (sudden, infrequent, not reasonably
preventable and not caused by poor maintenance and or careless
operation). For example, to successfully assert the affirmative defense,
the source must prove by a preponderance of the evidence that excess
emissions “[w]ere caused by a sudden, 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) to prevent future malfunctions. For
example, the source must prove by a preponderance of the evidence that
“[r]epairs were made as expeditiously as possible when the applicable
emission limitations were being exceeded…” and that “[a]ll
possible steps were taken to minimize the impact of the excess emissions
on ambient air quality, the environment and human health….” In any
judicial or administrative proceeding, the Administrator may challenge
the assertion of the affirmative defense and, if the respondent has not
met its burden of proving all of the requirements in the affirmative
defense, appropriate penalties may be assessed in accordance with
Section 113 (see also 40 CFR 22.27).

The EPA included an affirmative defense in the final 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 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), 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 requiring the reporting of
malfunctions as part of the affirmative defense provisions.

Add paragraphs in 40 CFR §63.1517 requiring the keeping of certain
records during 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.

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.

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 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 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.

Records must be maintained in a form suitable and readily available for
expeditious review, according to §63.10(b)(1). Electronic recordkeeping
and reporting is available for many records and is the form considered
most suitable for expeditious review if available. Electronic
recordkeeping and reporting is encouraged in this proposal and some
records and reports are required to be kept in electronic format.

3. Capture and Collection Requirements 

The current MACT rule uses the ACGIH Industrial Ventilation Manual as
the standard for acceptable capture and collection of emissions from a
source. Since the inception of the rule, several different methodologies
of demonstrating compliance with capture and collection requirements
have been accepted by the EPA. We are proposing that facilities must
follow the ACGIH guidelines published in 2003 or, as an alternative that
facilities can follow any updated versions published by ACGIH since that
time. Nevertheless, we are considering allowing other acceptable
methodologies for demonstration of compliance, which will provide more
flexibility to the industry. We invite comments on other acceptable
methodologies in addition to the ACGIH guidelines and how the secondary
aluminum NESHAP could be revised to better characterize hooding
requirements that would be adequate to ensure good capture of emissions.
We are requesting information on minimum face velocity, elimination of
visible emissions, minimum pressure drop or other parameter(s) that may
be used to demonstrate adequate capture.

4. Scrap Inspection Program for Group 1 Furnace without Add-on Air
Pollutions Control Devices

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 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. However, 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 considering
adding a requirement in the final rule that all owners and operators
with uncontrolled group 1 furnaces develop and implement a scrap
inspection program similar to the existing optional requirements in
section 63.1510(p). We are requesting comments 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 rule currently allows testing to demonstrate compliance under a
“worst-case” scenario. Facilities that process a range of materials
(including dross, used beverage containers (UBC), etc.) may have
different “worst-case” scenarios (highest production levels, range
of charge materials, and highest reactive fluxing rate) for the
different pollutants. For example, the worst-case scenario for HCl may
be while processing dross; the worst-case scenario for D/F formation may
be while processing UBC; and the worst-case scenario for PM is most
likely UBC as well. The original rule and subsequent amendments did not
make it clear that different testing conditions 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 worst-case for each regulated pollutant.

6. Lime Injection Rate Verification

The rule currently requires owners/operators to verify that the
continuous lime injection system maintain 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 requirement for the
verification of the lime injection rate in pounds per hour at least once
per month.

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 bath. 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 indicating that most furnaces are agitated. Rotary
furnaces are constantly rotated until the metal 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. Other sources claiming to be using a
cover flux are using them in furnaces in which the melt is being
agitated and, therefore, does not meet the definition of cover flux. To
address this, we are proposing to clarify the definition of 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 fan used
to collect a contaminant at or near its source and transport the
contaminated air to the air cleaning device.

10. Bale Breakers

	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 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 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 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.

13. Testing Representative Units

Section §63.1511 allows testing of a representative emissions unit to
estimate emissions from 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.

14. Initial Performance Tests

Section 63.1511(b) of the current rule requires a source 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. If a furnace is equipped with a baghouse, the
temperature of the gas flow at the baghouse inlet must be determined.
The inlet temperature is significantly affected by ambient air
temperatures. Exhaust gases going to the baghouse control system usually
include more ambient air than furnace exhaust gas, because a substantial
amount of ambient air is necessary to achieve adequate capture
efficiency. The high ratio of ambient air to furnace gas in the control
system means that the ambient air temperature often controls the
baghouse inlet temperature. When a facility conducts an initial
performance test in colder months (in order to meet the 90-day window in
the MACT standard), it must frequently retest in warmer months because
they cannot maintain the baghouse inlet temperature established during a
cold month.

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/Decoating Kiln and Scrap
Shredder

We are proposing revisions to the definition of scrap
dryer/delacquering/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. The sources in question operate chambers
with a maximum temperature of 900 degrees Fahrenheit and with no melting
of the recovered aluminum. Subsequent melting of recovered aluminum need
not occur at the same facility that conducts the recovery operation. We
are also proposing to amend the definition of a scrap shredder to
include granulation in addition to crushing, grinding, shearing 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 any of 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. Measurements of HF in Addition to HCl

The current standard contains limits for HCl emissions, and requires
operators to conduct performance tests for HCl emissions. The EPA’s
original intent was that HCl would serve as a surrogate for all acid
gases, including HF and chlorine. Where fluorine fluxes were used along
with chlorine-containing fluxes, lime coated fabric filters would
effectively control HF as well as HCl so that measuring HF was not
considered necessary. However, a facility that exclusively used
fluorine-containing fluxes would not be required to test for HF, and if
testing for HCl would have very low HCl emissions. 

Therefore, we are proposing amendments to clarify the conditions under
which testing must be conducted for both HF and HCl. We are still
confident that, where fluorine flux is used, lime coated fabric filter
will effectively remove HF as well as HCl. However, in instances where
there is no add-on control device and fluorine fluxes are used, we are
proposing that testing for HF be conducted. Where testing for HF and HCl
must be conducted, we are proposing that EPA Method 26A, which is
capable of measuring HCl and HF, be the measurement method used. We are
also proposing that the emission limit for the combined HCl and HF
measurements be equal to the current HCl limit, on the basis that the
best performing facilities used to establish the current standard did
not use any fluorine-containing fluxes. Testing for HF as well as HCl
would be required at the next scheduled performance test. As an
alternative to testing for HF and HCl, 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 chlorine and
fluorine in the reactive fluxes added to the source are emitted as HCl
or HF. 

We estimate that approximately 20 facilities that are major sources use
fluorine-containing fluxes. Since most of these facilities also use
fluxes containing chlorine, they are required to determine HCl emissions
at least once every five years. Therefore, the only additional costs
would be the laboratory analysis for HF. We estimate these costs to be
approximately $1,000 per test and that there are approximately 70
uncontrolled furnaces at major sources that use fluorine-containing
fluxes, and would be required to test every 5 years. Therefore, the
total cost of this proposed rule revision is estimated to be $14,000 per
year for the entire industry.

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 American Council of Government
Hygienists in chapters 3 and 5 of “Industrial Ventilation: A Manual of
Recommended Practice(23rd Edition).” However, there are no similar
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 during testing that
escape 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. 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 requirements would be implemented at
the next scheduled performance test. 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 comments and information
regarding other possible approaches 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 these fugitive
emissions, including approaches that could be adapted for different
furnace configurations, and 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 install hooding that meets ACGIH guidelines for testing or
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.	“Industrial Ventilation: A Manual of Recommended Practice”, 23rd
Edition

	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. This version of the manual is no longer in print. Therefore we are
proposing that the 23rd or later editions to the manual may be used.

21. 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.

22. 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 is coated with dyes
or sealants that contain organic material.

23. 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 streams 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. 

	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.” 

24. SAPU Feed/Charge Rate

		Some enforcement officials have interpreted the 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 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. 

25. Changing Furnace Designations

	The rule currently does not address whether a facility may change
furnace operating modes between group 1 controlled and group 1
uncontrolled, or between group 1 and group 2. The EPA sees no reason not
to allow owner/operators to change a furnace operating mode, as long as
the change is fully compliant with the substantive and procedural
requirements of the rule. Because the rule does not expressly provide
for such changes, we are proposing new provisions in §63.1516 that
specify how owners/operators can switch furnace operating modes. The
proposed amendments would apply to the following situations: 1)
switching from a controlled group 1 furnace handling other than clean
charge to an uncontrolled group 1 furnace handling other than clean
charge, 2) switching from a controlled group 1 furnace processing other
than clean charge to an uncontrolled clean charge group 1 furnace, 3)
switching from a group 1 controlled or uncontrolled furnace to a group 2
furnace, and 4) switching from a group 1 controlled or uncontrolled
furnace to a group 2 furnace, for furnaces capable of completely
removing furnace content between batches. This would include furnaces
with a sidewell. The proposed revisions specify the emissions testing
that would be required to switch furnace designation; operating
requirements, such as labeling, flux use, and scrap charging for the
furnace before, during, and after switching; and requirements for
records to be kept. The proposed revisions also would limit changes in
furnace operating mode to occur no more frequently than once every 6
months, except situations wherein control device maintenance is being
performed. When following the substantive and procedural requirements of
this rule, the owners/operators would be able to turn off associated air
pollution control devices. Because of this, 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 $500,000 per year. Therefore, we estimate the net cost to be
-$600,000 per year (a savings of $600,000 per year). 

26.	ACGIH Hooding Requirements

	The current rule requires that emissions capture and collection systems
be designed consistent with the ACGIH industrial ventilation guidelines.
Industry representatives point out that the manual contains
“recommended” ventilation practices and that EPA has inappropriately
required compliance with the guidelines. For example, the guidance
establish a design criteria for determining minimum hood dimensions and
flow; however, the relevant equation is not appropriate for determining
minimum flow requirements for “oversized” hoods that are used in the
secondary aluminum 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 of the hoods and that
engineering evaluations of hoods can be performed similarly to those for
other engineered processes. Also, there may be other rules and
ventilation guidelines that are appropriate and could be used.

	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. 

27.	Dross Only Versus Dross/Scrap Furnaces

	The EPA’s current interpretation of the existing rule is that dross
only furnaces at area sources are not subject to D/F emission
limitations and therefore 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 point out that dross only furnaces have been 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, 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.

28. Annual Hood Inspections

    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. They
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 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
changes to the rule to clarify 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.

29.	Applicability of Rule to Area Sources

	While the emissions standards that apply to area sources is 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 standards apply to area sources. 

30.	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. It was
never our intent 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,
provided that the site-specific test plan documents the intent to
establish new or revised parametric limits. 

31.	Controlled Furnaces that are Temporarily Idled 

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.

E. Compliance dates

We are proposing that existing facilities must comply with all changes
proposed in this action upon promulgation of the final rule. All new or
reconstructed facilities must comply with all requirements in this rule
upon startup.

V. Summary of Cost, Environmental, and Economic Impacts

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. 

B. What are the air quality impacts?

No reductions are being proposed to numerical emissions limits. The
proposed amendments will add work practices for periods of startup and
shutdown to help ensure that emissions from affected sources continue to
be 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 using fluorine fluxes 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 in little or no
emissions reductions. Therefore, no air quality impacts are expected.

C. What are the cost impacts?

We estimate that there will be minor cost impacts associated with these
proposed requirements. We estimate the total cost of the proposed
amendments to be up to approximately $614,000 per year. 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 $14,000 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 switch
furnace categories 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.

 D. What are the economic impacts?

Because there are only minor cost impacts, we do not expect economic
impacts.

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 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

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)

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 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 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.

We are proposing new paperwork requirements to the Secondary Aluminum
Production source category in the form of [To be completed on
development of supporting statement]

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 an exceedance 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 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 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
$1,384,821 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 $1,219,300 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 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 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-for-profit 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. Of the 31
entities affected by this proposed rule, ten of them are small. Of these
ten, only one is estimated to experience a positive cost as a result of
the rule, and that one small entity will have an impact that is an
annualized cost of less than 0.01 percent of its sales. 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. The proposed rule
imposes no enforceable duties on any State, local or tribal governments
or the private sector. Thus, this proposed rule is not subject to the
requirements of sections 202 or 205 of the UMRA.

This proposed rule is also not subject to the requirements of section
203 of UMRA because it contains no regulatory requirements that might
significantly or uniquely affect small governments because it contains
no requirements that apply to such governments nor does it impose
obligations upon them.

E. Executive Order 13132: Federalism.

This proposed rule does not have federalism implications. It will not
have substantial direct effects on the States, on the relationship
between the national government and the States, or on the distribution
of power and responsibilities among the various levels of government, as
specified in Executive Order 13132. None of the facilities subject to
this action are owned or operated by State governments, and, because no
new requirements are being promulgated, nothing in this proposed rule
will supersede State regulations. Thus, Executive Order 13132 does not
apply to this proposed rule.

In the spirit of Executive Order 13132, and consistent with 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 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. Nevertheless, the public is
invited to submit comments or identify peer-reviewed studies and data
that assess effects of early life exposure to HAP from Secondary
Aluminum sources.

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 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.

EPA has determined that this proposed rule will not have
disproportionately high and adverse human health or environmental
effects on minority, low income, indigenous populations because it
increases the level of environmental protection for all affected
populations without having any disproportionately high and adverse human
health or environmental effects on any population, including any
minority, low income or indigenous populations.

These proposed standards may improve public health and welfare, now and
in the future, by limiting HAP emissions that may contribute to adverse
environmental and human health impacts. The control of HAP emissions
associated with the rule are expected to benefit all populations living
near the sources affected by this rule. 

Additionally, the Agency has 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
analysis only gives some indication of the prevalence of sub-populations
that may be exposed HAP pollution from the sources affected by this
rulemaking; it does not identify the demographic characteristics of the
most highly affected individuals or communities, nor does it quantify
the level of risk faced by those individuals or communities. 

The major source demographic 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).

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.

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 63.1502 is amended by revising paragraph (a)(1) 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. Section 63.1503 is amended by:

a. Adding, in alphabetical order, new definitions of “affirmative
defense,” “bale breaker,” “capture and collection system,”
“HCl/HF” and “HF”; and

	b. Revising the definitions of “aluminum scrap shredder,”
“chips,” “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.

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 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,
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
transport the contaminated air to the air cleaning device.

Chips means small, uniformly-sized, unpainted pieces of aluminum scrap,
typically below 1 1/4 inches in any dimension, primarily generated by
turning, milling, boring, and machining of aluminum parts.

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 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-HAP-containing/non-HAP-generating
gases or agents. Pots used to transport metal to customers are not
furnaces.

HCl means, for the purposes of this subpart, emissions of hydrogen
chloride that serve as a surrogate measure of the total emissions of the
HAPs hydrogen chloride, hydrogen fluoride and chlorine. For an
uncontrolled group 1 furnace that uses a flux that contains fluorine,
HCl means the combined emissions of hydrogen chloride and hydrogen
fluoride.

HCl/HF means the combined emissions of HCl and HF from an uncontrolled
group 1 furnace that uses one or more fluxes containing chlorine and/or
fluorine.

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 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.

*	*	*	*	*

4. Section 63.1505 is amended by: 

a. By revising paragraph (d)(1)(iv); 

b. By revising paragraph (e)(1)(iv); 

c. By revising paragraph (i)(4); 

d. By revising paragraph (j)(1); 

e. By revising paragraph (k); 

f. By revising paragraph (k)(1); 

g. By revising paragraph (k)(2); and 

h. By revising paragraph (k)(3)to read as follows:

§63.1505 Emission standards for affected sources and emission units.

*	*	*	*	*

(d) *		*	*

	(1) *		*	*

(iv) 0.40 kg of HCl/HF per Mg (0.80 lb per ton) of feed/charge from a
scrap dryer/delacquering kiln/decoating kiln at a secondary aluminum
production facility that is a major source.

*	*	*	*	*

(e) *		*	*

	(1) *		*	* 

(iv) 0.75 kg of HCl/HF per Mg (1.50 lb per ton) of feed/charge from a
scrap dryer/delacquering kiln/decoating kiln at a secondary aluminum
production facility that is a major source.

*	*	*	*	*

(i) *		*	*

	(4) 0.20 kg of HCl/HF per Mg (0.40 lb of HCl/HF 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/HF emissions, by weight, for
a group 1 furnace at a secondary aluminum production facility that is a
major source. 

*	*	*	*	*

(j) * 	*	*

	(1) 0.02 kg of HCl/HF per Mg (0.04 lb of HCl/HF per ton) of
feed/charge;

*	*	*	*	*

 (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 and HCl/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:

 

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/HF
in excess of:

 

Where,

LtiHCl /HF= The HCl/HF emission limit for individual emission unit i in
paragraph (i)(4) of this section for a group 1 furnace or in paragraph
(j)(1) of this section for an in-line fluxer; and

LcHCl /HF= The daily HCl/HF emission limit for the secondary aluminum
processing unit  which is used to calculate the 3-day, 24-hour HCl/HF
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 HCl/HF
limit.

(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:

 

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.

*	*	*	*	*

5. 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); 

g. By revising paragraph (n)(1); and 

h. By adding paragraph (q)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), (p), and (q) 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 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 the “Industrial Ventilation: A Manual of Recommended
Practice” 23rd edition or later (ACGIH Guidelines) (incorporated by
reference in §63.1502 of this subpart);

*	*	*	*	*

(g) *	*	*

(5) For a continuous injection device, maintain free-flowing 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) *	*	*

(3) For a continuous injection system, maintain free-flowing 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 free-flowing 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.

*	*	*	*	*

(q) Work practices for periods of startup and shutdown. During periods
of startup and shutdown the owner or operator must meet the requirements
listed in (q)(1) through (7) of this section.

(1) Use natural gas or other clean fuels such as propane, kerosene or
number 2 fuel oil during startup, which begins when a dryer, kiln, sweat
furnace, dross-only furnace, or group 1 furnace begins ignition and
equipment warming.

(2) All associated exhaust fans, capture hoods, and air pollution
control devices must be engaged and operated whenever fuel is fired to
the affected sources listed in (q)(1) of this section.

(3) Startup ends at the point that scrap or charge materials are
introduced into the affected sources listed in (q)(1) of this section
and the process is considered to be in normal operating mode.

(4) Shutdown begins when an owner or operator halts the introduction of
scrap or charge into and removes all scrap or charge from the affected
sources listed in (q)(1).

(5) During shutdown, any associated exhaust fans, capture hoods, and air
pollution control devices must remain engaged and operating until the
temperature of the exhaust gases fall below 200 °F at which point
shutdown ends. If a furnace will be partially shutdown at the end of a
cycle for at least 24 hours and will burn clean fuel only, will not
receive new charge, will not receive flux, and will not receive alloying
materials, then the applicable exhaust fans, capture hoods, and air
pollution control devices may be temporarily turned off. Before any new
charge is added to the furnace, the applicable exhaust fans, capture
hoods, and air pollution control devices must be engaged and operated.
Any molten aluminum remaining in the furnace must be covered to reduce
the likelihood of emissions from the furnace while the furnace is idle.
When the furnace resumes operation, it must operate in its current
furnace operating mode.

(6) For the affected sources listed in (q)(1) of this section, the owner
or operator must comply with all applicable emissions standards in
§63.1505 at all time except for startup and shutdown periods.

(7) The owner or operator must develop a written plan that describes the
procedures to be followed for operating and maintaining the affected
sources listed in (q)(1) of this section during periods of startup and
shutdown. Submit the plan to the applicable permitting authority for
approval within [INSERT DATE 90 DAYS AFTER THE EFFECTIVE DATE OF THIS
RULE].

*	*	*	*	*

6. Section 63.1510 is amended by: 

a. By revising paragraph (a); 

b. By revising paragraph (b); 

c. By revising paragraph (b)(5); 

d. By revising paragraph (d)(2); 

e. By revising paragraph (f)(1)(ii); 

f. By adding paragraph (i)(4); 

g. By revising paragraph (j)(4); 

h. By revising paragraph (n)(1); 

i. By revising paragraph (o)(1); 

j. By revising paragraph (o)(1)(ii); 

k. By revising paragraph (t); 

l. By adding paragraph (t)(2)(i);

m. By adding paragraph (t)(2)(ii); 

n. By revising paragraph (t)(4); and 

o. By 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:

(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 detector requirements described in paragraph (f) of
this section applicable to all bag leak detectors 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,

(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, thermal chip dryers, 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,

(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
secondary aluminum processing units, limited to only 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 only 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 only 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

(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, and 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 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.

*	*	*	*	*

(d) *	*	*

(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
lb/hr is no less than 90 percent of the lime injection rate used to
demonstrate compliance during your performance test.

*	*	*	*	*

(j) *	*	*

(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 that
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 site-specific monitoring
plan. The site-specific monitoring plan must be submitted to the
permitting authority as part of the OM&M 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, HCl/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, HCl/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, D/F and, for
uncontrolled group 1 furnaces, HCl/HF and the proposed monitoring
parameters for each pollutant. Test data must establish the highest
level of PM, HCl, D/F and, for uncontrolled group 1 furnaces, HCl/HF
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.

*	*	*	*	*

(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, D/F and, for 
uncontrolled group 1 furnaces, HCl/HF 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) *	*	*

(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 a performance test for
HCl/HF for a group 1 furnace or in-line fluxer, in accordance with the
provisions of  §63.1512(d)(3), §63.1512(e)(3), or §63.1512(h)(2), the
calculation required in §63.1510(t)(4) to determine SAPU wide HCl/HF
emissions shall be made under the assumption that all reactive flux
added to the emission unit is emitted as HCl or HF. 

*	*	*	*	*

 (4) Compute the 24-hour daily emission rate using Equation 4:

 

Where,

Eday= The daily PM, HCl, D/F and, for uncontrolled group 1 furnaces,
HCl/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).

*	*	*	*	*

7. 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); 

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 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 expected to be processed, at the
highest rate of production expected to be processed and using the
highest reactive fluxing rate expected to be processed in controlled
mode. Any subsequent performance tests for the purposes of establishing
new or revised parametric limits shall be allowed upon pre-approval 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 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. Test to measure HCl and HF must be conducted
at the next required performance test.

*	*	*	*	*

(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.

*	*	*	*	*

8. Section 63.1512 is amended by: 

a. By revising paragraph (c); 

b. By revising paragraph (d)(3); 

c. By revising paragraph (e)(1);

d. By revising paragraph (e)(2); 

e. By revising paragraph (e)(3); 

f. By adding paragraphs (e)(4); 

g. By adding paragraphs (e)(5); 

h. By revising paragraph (h)(1); 

i. By revising paragraph (h)(2); 

j. By revising paragraph (j); 

k. By revising paragraph (j)(1);  

l. By revising paragraph (j)(2); 

m. By revising paragraph (j)(3) 

n. By revising paragraph (n)(1); 

o. By revising paragraph (o)(1); 

p. By revising paragraph (p); and

q. By revising paragraph (p)(2)to read as follows:

§63.1512 Performance test/compliance demonstration requirements and
procedures.

*	*	*	*	*

(c) Scrap dryer/delacquering kiln/decoating kiln. The owner or operator
must conduct performance tests to measure emissions of THC, D/F, HCl/HF,
and PM at the outlet of the control device.

*	*	*	*	*

(d) *	*	*

(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/HF.

*	*	*	*	*

(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 and HF and HCl/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.

(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 HF
or HCl.

(4) When testing an existing uncontrolled furnace, the owner or operator
must either:

(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 and

(iii) Comply with the requirements of paragraphs (e)(4)(i) and (ii) of
this section at the next required performance test.

(5) When testing a new uncontrolled furnace the owner or operator must
either: 

(i) Install hooding that meets ACGIH Guidelines, or 

(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/HF
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
chlorine flux is added to an in-line fluxer and assume, for the purposes
of demonstrating compliance with the SAPU emission limit, that all
chlorine/fluorine in the reactive flux added to the in-line fluxer is
emitted as HCl/HF. Under these circumstances, the owner or operator is
not required to conduct an emission test for HCl/HF. 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 limit for HCl/HF by limiting
use of reactive chlorine/fluorine flux and assuming that all
chlorine/fluorine in the flux is emitted as HCl/HF, compliance with the
HCl/HF limit shall also constitute compliance 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/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/HF (for the emission limit); or

(ii) The mass flow rate of HCl/HF at the inlet to and outlet from the
control device (for the percent reduction standard).

*	*	*	*	*

 (2) *	*	*

(i) Emissions of HCl/HF (for the emission limit); or

(ii) The mass flow rate of HCl/HF at the inlet to and outlet from the
control device (for the percent reduction standard).

*	*	*	*	*

 (3) Each in-line fluxer to measure emissions of PM and HCl/HF.

*	*	*	*	*

(n) *	*	*

(1) Continuously measure and record the temperature at the inlet to the
lime-injected fabric filter every 15 minutes during the HCl/HF and D/F
performance tests;

*	*	*	*	*

(o) *	*	*

(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) Lime injection. The owner or operator of an affected source or
emission unit using a lime-injected fabric filter system must use these
procedures during the HCl/HF and D/F tests to establish an operating
parameter value for the feeder setting and lime injection rate for each
operating cycle or time period used in the performance test.

*	*	*	*	*

 (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.

*	*	*	*	*

9. 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.

*	*	*	*	*

(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 or HCl/HF:

 Where:

E = Emission rate of PM or HCl/HF, kg/Mg (lb/ton) of feed;

C = Concentration of PM or HCl, 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).

 

Where,

EcPM= The mass-weighted PM emissions for the secondary aluminum
processing unit;

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 co-controlled
emission units in the secondary aluminum processing unit.

(2) Use Equation 10 to compute the aluminum mass-weighted HCl/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).

 

Where,

EcHCl/HF= The mass-weighted HCl and HF emissions for the secondary
aluminum processing unit; and

EtiHCl/HF= Measured HCl/HF emissions for individual emission unit, or
group of co-controlled emission units i.

(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).

 

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.

*	*	*	*	*

10. Section 63.1514 is revised to read as follows:

§63.1514 Change of Furnace Classification.

(a) Changing from a group 1 controlled furnace processing other than
clean charge to group 1 uncontrolled furnace processing other than clean
charge.  

An owner or operator wishing to change operating modes must conduct
performance tests to demonstrate to the delegated permitting 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/HF and 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 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.

(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 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.

(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 switch 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 switch 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
switch (controlled to uncontrolled, or uncontrolled to controlled), the
time the switch 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 and to 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
permitting 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/HF and 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 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.

(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 and HCl/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.

(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 at the expected to be processed in uncontrolled mode at
the highest throughput 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 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 switch 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 switch 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 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
switch (controlled to uncontrolled, or uncontrolled to controlled), the
time the switch 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 permitting 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
switching to group 2 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.

(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 to be processed 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 standards 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.

(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/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 switching to
group 2 mode.

(3) Operators of area sources must conduct 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 and using the highest rate of
reactive flux injection expected to be processed 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 conducted is
established as an operating parameter to be met before switching to
group 2 mode.

(d) Changing from a group 1 controlled or uncontrolled furnace to group
2 furnace, for tilting reverberatory furnaces 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
injection expected to be processed in controlled 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.

(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.

(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 to be processed 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 switch modes between group 1 and group 2, the operator must

(i) Completely remove all aluminum from the furnace;

(ii) Change the furnace label;

(iii) Use only clean charge; and

(iv) Use no reactive flux;

(4)To switch modes between group 2 and group 1, the owner or operator
must, before charging other than clean charge or 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
switch (group 1 to group 2, or group 2 to group 1), the time the switch
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 switching furnace status. Switching furnace status as
provided in paragraphs (a) through (c) of this section may not be done
more frequently than once every 6 months unless necessary to perform
maintenance on the furnace.

*	*	*	*	*

11. Section 63.1515 is amended by removing paragraph (b)(10).

12. Section 63.1516 is amended by: 

a. By removing and reserving paragraph (a); 

b. By revising paragraph (b)(2)(iii); 

c. By adding paragraph (b)(3); 

d. By revising paragraph (c); and

e. By adding paragraph(d)to read as follows:

§63.1516 Reports.

*	*	*	*	*

(a) [Reserved]

(b) *	*	*

(2) *	*	*

(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 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 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. 

*	*	*	*	*

13. Section 63.1517 is amended by: 

a. By revising paragraph( b)(3); 

b. By revising paragraph (b)(10); 

c. By revising paragraph (b)(16)(i); 

d. By adding paragraph (b)(18); and

e. By adding paragraph (c)to read as follows:

§63.1517 Records.

*	*	*	*	*

(b) *	*	*

(3) For each scrap dryer/delacquering kiln/decoating kiln and group 1
furnace, subject to D/F and HCl/HF emission standards with emissions
controlled by a lime-injected fabric filter, records of 15-minute block
average inlet temperatures for each lime-injected fabric filter,
including any period when the 3-hour block average temperature exceeds
the compliant operating parameter value +14 °C (+25 °F), with a brief
explanation of the cause of the excursion and the corrective action
taken.

*	*	*	*	*

 (10) Operating logs for each group 1 sidewell furnace with add-on air
pollution control devices documenting conformance with operating
standards for maintaining the level of molten metal above the top of the
passage between the sidewell and hearth during reactive flux injection
and for adding reactive flux only to the sidewell or a furnace hearth
equipped with a control device for PM, HCl/HF, and D/F emissions.

*	*	*	*	*

 (16) *	*	*

(i) Startup and shutdown plan;

*	*	*	*	*

 (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.

*	*	*	*	*

14. Section 63.1520 is revised to read as follows: 

§63.1520 Affirmative defense for exceedance of emission limit during
malfunction.

In response to an action to enforce the standards set forth in this
subpart, you may assert an affirmative defense to a claim for civil
penalties for exceedances 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

(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

(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) Notification. The owner or operator of the affected source
experiencing an exceedance of its emission limit(s) during a
malfunction, shall notify the Administrator by telephone or facsimile
transmission as soon as possible, but no later than two business days
after the initial occurrence of the malfunction, if it wishes to avail
itself of an affirmative defense to civil penalties for that
malfunction. The owner or operator seeking to assert an affirmative
defense, shall also submit a written report to the Administrator within
45 days of the initial occurrence of the exceedance of the standards in
this subpart to demonstrate, with all necessary supporting
documentation, that it has met the requirements set forth in paragraph
(e) 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 exceedance.

*	*	*	*	*

15. Table 1 to Subpart RRR is amended to read as follows:

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 add-on 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 kilnh

or	PM	0.08	lb/ton of feed

	HCl/HF	0.8	lb/ton of feed

	THC	0.06	lb/ton of feed

	D/Fa	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	0.08
lb/ton of feed

	HCl/HF	0.8	lb/ton of feed

	THC	0.06	lb/ton of feed

	D/Fa	0.25	ug TEQ/Mg of feed

New or existing sweat furnaceh	D/Fa	0.8	ng TEQ/dscm @ 11% O2 b

New or existing dross-only furnaceh	PM	0.3	lb/ton of feed

New or existing in-line fluxer footnote	HCL/HF	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

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, h 	PM	0.8	lb/ton of feed

	HCL/HF	0.4	lb/ton of feed



or



	10	percent of the HCl upstream of the add-on control device

New and existing group 1 furnacec, h	PM	0.4	lb/ton of feed

	HCL/HF	0.4	lb/ton of feed



or



	10	percent of the HCl upstream of the add-on control device

	D/Fa	15	ug/TEQ/Mg of feed

New and existing group 1 furnace with clean charge onlyh	PM	0.4	lb/ton
of feed

	HCL/HF	0.4	lb/ton of feed



or



	10	percent of the HCl upstream of the add-on control device

	D/Fa	No limit	Clean charge only

New and existing group 1 furnace, uncontrolled for HCl/HF, and using
flux containing fluorineh	Combined HCl and HF	0.40	lb/ton of feed

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
in-lie fluxers)

PMe



	



HCl/HF





	D/Fg



	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 uniti 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/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/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/HF limit.

g Clean charge furnaces cannot be included in this calculation since
they are not subject to the D/F limit.

h During periods of startup and shutdown, affected source is not subject
to numerical emissions limits but must be operated according to the work
practice provisions in section §63.1506(q).

*	*	*	*	*

16. Appendix A to Subpart RRR is amended 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

§63.1(a)(1)–(4)	General Applicability	Yes.

	§63.1(a)(5)

No	[Reserved].

§63.1(a)(6)–(8)

Yes.

	§63.1(a)(9)

No	[Reserved].

§63.1(a) (10)–(14)

Yes.

	§63.1(b)	Initial Applicability Determination	Yes	EPA retains approval
authority.

§63.1(c)(1)	Applicability After Standard Established	Yes.

	§63.1(c)(2)

Yes	§63.1500(e) exempts area sources subject to this subpart from the
obligation to obtain Title V operating permits.

§63.1(c)(3)

No	[Reserved].

§63.1(c)(4)–(5)

Yes.

	§63.1(d)

No	[Reserved].

§63.1(e)	Applicability of Permit Program	Yes.

	§63.2	Definitions	Yes	Additional definitions in §63.1503.

§63.3	Units and Abbreviations	Yes

	§63.4(a)(1)–(3)	Prohibited Activities	Yes.

	§63.4(a)(4)

No	[Reserved]

§63.4(a)(5)

Yes.

	§63.4(b)–(c)	Circumvention/ Severability	Yes.

	§63.5(a)	Construction and Reconstruction—Applicability	Yes.

	§63.5(b)(1)	Existing, New, Reconstructed Sources—Requirements	Yes.

	§63.5(b)(2)

No	[Reserved].

§63.5(b)(3)–(6)

Yes.

	§63.5(c)

No	[Reserved].

§63.5(d)	Application for Approval of Construction/ Reconstruction	Yes.

	§63.5(e)	Approval of Construction/ Reconstruction	Yes.

	§63.5(f)	Approval of Construction/Reconstruction Based on State Review
Yes.

	§63.6(a)	Compliance with Standards and Maintenance—Applicability
Yes.

	§63.6(b)(1)–(5)	New and Reconstructed Sources—Dates	Yes.

	§63.6(b)(6)

No	[Reserved].

§63.6(b)(7)

Yes.

	§63.6(c)(1)	Existing Sources Dates	Yes	§63.1501 specifies dates.

§63.6(c)(2)

Yes.

	§63.6(c)(3)–(4)

No	[Reserved].

§63.6(c)(5)

Yes.

	§63.6(d)

No	[Reserved].

63.6(e)(1)(i)

No	See 63.1506(A)(5) and 63.1520(a)(8) for general duty requirement.

63.6(e)(1)(ii)

No

	63.6(e)(1)(iii)

Yes

	§63.6(e)(2)	Operation & Maintenance Requirements	Yes	§63.1510
requires plan.

§63.6(e)(3)	Startup, Shutdown Plan	No	Startup and Shutdown Plan Only

§63.6(f)	Compliance with Emission Standards	Yes.

	§63.6(g)	Alternative Standard	No

	§63.6(h)	Compliance with Opacity/VE Standards	Yes.

	§63.6(i)(1)–(14)	Extension of Compliance	Yes.

	§63.6(i)(15)

No	[Reserved].

§63.6(i)(16)

Yes.

	§63.6(j)	Exemption from Compliance	Yes.

	§63.7(a)–(h)	Performance Test Requirements-Applicability and Dates
Yes	Except §63.1511 establishes dates for initial performance tests.

§63.7(b)	Notification	Yes.

	§63.7(c)	Quality Assurance/Test Plan	Yes.

	§63.7(d)	Testing Facilities	Yes.

	§63.7(e)	Conduct of Tests	Yes.

	§63.7(f)	Alternative Test Method	Yes.

	§63.7(g)	Data Analysis	Yes.

	§63.7(h)	Waiver of Tests	Yes.

	§63.8(a)(1)	Monitoring Requirements—Applicability	Yes.

	§63.8(a)(2)

Yes.

	§63.8(a)(3)

No	[Reserved]

§63.8(a)(4)

Yes

	§63.8(b)	Conduct of Monitoring	Yes.

	63.8(c)(1)(i)

No	See 63.843(f) and 63.844(f) for general duty requirement.

§63.8(c)(1)(ii)–(3)	CMS Operation and Maintenance	Yes.

	§63.8(c)(4)–(8)

Yes.

	§63.8(d)	Quality Control	Yes.

	§63.8(e)	CMS Performance Evaluation	Yes.

	§63.8(f)(1)–(5)	Alternative Monitoring Method	No	§63.1510(w)
includes provisions for monitoring alternatives.

§63.8(f)(6)	Alternative to RATA Test	Yes.

	§63.8(g)(1)	Data Reduction	Yes.

	§63.8(g)(2)

No	§63.1512 requires five 6-minute averages for an aluminum scrap
shredder.

§63.8(g)(3)–(5)

Yes.

	§63.9(a)	Notification Requirements—Applicability	Yes.

	§63.9(b)	Initial Notifications	Yes.

	§63.9(c)	Request for Compliance Extension	Yes.

	§63.9(d)	New Source Notification for Special Compliance Requirements
Yes.

	63.9(e)	Notification of Performance Test	Yes.

	§63.9(f)	Notification of VE/Opacity Test	Yes.

	§63.9(g)	Additional CMS Notifications	Yes.

	§63.9(h)(1)–(3)	Notification of Compliance Status	Yes	Except
§63.1515 establishes dates for notification of compliance status
reports.

§63.9(h)(4)

No	[Reserved].

§63.9(h)(5)–(6)

Yes.

	§63.9(i)	Adjustment of Deadlines	Yes.

	§63.9(j)	Change in Previous Information	Yes.

	§63.10(a)	Recordkeeping/Reporting—Applicability	Yes.

	§63.10(b)	General Requirements	Yes	§63.1517 includes additional
requirements. See 63.1517(x),(y) and (z) for recordkeeping of occurrence
and duration of malfunctions and recordkeeping of actions taken during
malfunction.

§63.10(c)(1)	Additional CMS Recordkeeping	Yes.

	§63.10(c)(2)–(4)

No	[Reserved].

§63.10(c)(5)

Yes.

	§63.10(c)(6)

Yes.

	§63.10(c)(7)–(8)

Yes.

	§63.10(c)(9)

No	[Reserved].

§63.10(c)(10)–(13)

Yes.	See 63.1517(e)(4)(xvi) and (xvii)for recordkeeping of malfunctions.

§63.10(c)(14)

Yes.

	§63.10(d)(1)	General Reporting Requirements	Yes.

	§63.10(d)(2)	Performance Test Results	Yes.

	§63.10(d)(3)	Opacity or VE Observations	Yes.

	§63.10(d)(4)–(5)	Progress Reports/Startup, Shutdown, and Malfunction
Reports	Yes.

	§63.10(e)(1)–(2)	Additional CMS Reports	Yes.

	§63.10(e)(3)	Excess Emissions/CMS Performance Reports	Yes	Reporting
deadline given in §63.1516.

§63.10(e)(4)	COMS Data Reports	Yes.

	§63.10(f)	Recordkeeping/Reporting Waiver	Yes.

	§63.11(a)–(b)	Control Device Requirements	No	Flares not applicable.

§63.12(a)–(c)	State Authority and Delegations	Yes.	EPA retains
authority for applicability determinations.

§63.13	Addresses	Yes.

	§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).

§63.15	Availability of Information/Confidentiality	Yes.

	

 “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.

 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.

 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.

 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).

 A census block is generally the smallest geographic area for which
census statistics are tabulated.   

 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/214C6E915BB04E14852570CA007A6
82C/$File/ecadv02001.pdf.

 NAS, 2001. Standing Operating Procedures for Developing Acute Exposure
Levels for Hazardous Chemicals, page 2.

 ERP Committee Procedures and Responsibilities. November 1, 2006.
American Industrial Hygiene Association.

 See http://www.tceq.state.tx.us/compliance/field_ops/eer/index.html or
docket to access the source of these data.

 The SAB peer review of RTR Risk Assessment Methodologies is available
at:
http://yosemite.epa.gov/sab/sabproduct.nsf/4AB3966E263D943A8525771F00668
381/$File/EPA-SAB-10-007-unsigned.pdf.

 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.

 U.S. EPA. National-Scale Air Toxics Assessment for 1996. (EPA
453/R–01–003; January 2001; page 85.)

 IRIS glossary (http://www.epa.gov/NCEA/iris/help_gloss.htm).

 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.

 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.

 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.

 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/4AB3966E263D943A8525771F00668
381/$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.

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