[Federal Register Volume 83, Number 86 (Thursday, May 3, 2018)]
[Proposed Rules]
[Pages 19499-19520]
[FR Doc No: 2018-09200]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2017-0358; FRL-9977-29-OAR]
RIN 2060-AT66

National Emission Standards for Hazardous Air Pollutants for
Friction Materials Manufacturing Facilities; Residual Risk and
Technology Review

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing
amendments to the National Emission Standards for Hazardous Air
Pollutants (NESHAP) for the Friction Materials Manufacturing Facilities
source category. The proposed amendments address the results of the
residual risk and technology reviews (RTRs) conducted as required under
the Clean Air Act (CAA). The proposed amendments also address the
startup, shutdown, and malfunction (SSM) provisions of the rule and
update the reporting and recordkeeping requirements.

DATES: Comments. Comments must be received on or before June 18, 2018.
Under the Paperwork Reduction Act (PRA), comments on the information
collection provisions are best assured of consideration if the Office
of Management and Budget (OMB) receives a copy of your comments on or
before June 4, 2018.
    Public Hearing. If a public hearing is requested by May 8, 2018,
then we will hold a public hearing on May 18, 2018 at the location
described in the ADDRESSES section. The last day to pre-register in
advance to speak at the public hearing will be May 16, 2018.

ADDRESSES: Comments. Submit your comments, identified by Docket ID No.
EPA-HQ-OAR-2017-0358, at http://www.regulations.gov. Follow the online
instructions for submitting comments. Once submitted, comments cannot
be edited or removed from Regulations.gov. Regulations.gov is our
preferred method of receiving comments. However, other submission
methods are accepted. To ship or send mail via the United States Postal
Service, use the following address: U.S. Environmental Protection
Agency, EPA Docket Center, Docket ID No. EPA-HQ-OAR-2017-0358, Mail
Code 28221T, 1200 Pennsylvania Avenue NW, Washington, DC 20460. Use the
following Docket Center address if you are using express mail,
commercial delivery, hand delivery, or courier: EPA Docket Center, EPA
WJC West Building, Room 3334, 1301 Constitution Avenue NW, Washington,
DC 20004. Delivery verification signatures will be available only
during regular business hours.
    Do not submit electronically any information you consider to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. See section I.C of this preamble
for instructions on submitting CBI.
    For additional submission methods, the full EPA public comment
policy, information about CBI or multimedia submissions, and general
guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets. The EPA may publish any
comment received to its public docket. Multimedia submissions (audio,
video, etc.) must be accompanied by a written comment. The written
comment is considered the official comment and should include
discussion of all points you wish to make. The EPA will generally not
consider comments or comment contents located outside of the primary
submission (i.e., on the Web, cloud, or other file sharing system). For
additional submission methods, the full EPA public comment policy,
information about CBI or multimedia submissions, and general guidance
on making effective comments, please visit https://www2.epa.gov/dockets/commenting-epa-dockets.
    Public Hearing. If a public hearing is requested, it will be held
at EPA's Headquarters, EPA WJC East Building, 1201 Constitution Avenue
NW, Washington, DC 20004. If a public hearing is requested, then we
will provide details about the public hearing on our website at:
https://www.epa.gov/stationary-sources-air-pollution/friction-materials-manufacturing-facilities-national-emission. The EPA does not
intend to publish another document in the Federal Register announcing
any updates on the request for a public hearing. Please contact Aimee
St. Clair at<PHONE_NUMBER> or by email at [email protected] to
request a public hearing, to register to speak at the public hearing,
or to inquire as to whether a public hearing will be held.
    The EPA will make every effort to accommodate all speakers who
arrive and register. If a hearing is held at a U.S. government
facility, individuals planning to attend should be prepared to show a
current, valid state- or federal-approved picture identification to the
security staff in order to gain access to the meeting room. An expired
form of identification will not be permitted. Please note that the Real
ID Act, passed by Congress in 2005, established new requirements for
entering federal facilities. If your driver's license is issued by a
noncompliant state, you must present an additional form of
identification to enter a federal facility. Acceptable alternative
forms of identification include: Federal employee badge, passports,
enhanced driver's licenses, and military identification cards.
Additional information on the Real ID Act is available at https://www.dhs.gov/real-id-frequently-asked-questions. In

addition, you will need to obtain a property pass for any personal
belongings you bring with you. Upon leaving the building, you will be
required to return this property pass to the security desk. No large
signs will be allowed in the building, cameras may only be used outside
of the building, and demonstrations will not be allowed on federal
property for security reasons.

FOR FURTHER INFORMATION CONTACT: For questions about this proposed
action, contact Korbin Smith, Sector Policies and Programs Division
(D243-04), Office of Air Quality Planning and Standards, U.S.
Environmental Protection Agency, Research Triangle Park, North Carolina
27711; telephone number:<PHONE_NUMBER>; fax number:<PHONE_NUMBER>;
and email address: [email protected]. For specific information
regarding the risk modeling methodology, contact James Hirtz, Health
and Environmental Impacts Division (C539-02), Office of Air Quality
Planning and Standards, U.S. Environmental Protection Agency, Research
Triangle Park, North Carolina 27711; telephone number:<PHONE_NUMBER>;
fax number:<PHONE_NUMBER>; and email address: [email protected]. For
information about the applicability of the NESHAP to a particular
entity, contact Sara Ayres, Office of Enforcement and Compliance
Assurance, U.S. Environmental Protection Agency, EPA WJC South Building
(Mail Code 2227A), 1200 Pennsylvania Avenue NW, Washington, DC 20460;
telephone number:<PHONE_NUMBER>; and email address:
[email protected].

SUPPLEMENTARY INFORMATION:
    Docket. The EPA has established a docket for this rulemaking under
Docket ID No. EPA-HQ-OAR-2017-0358. All documents in the docket are
listed in the 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 Regulations.gov or in
hard copy at the EPA Docket Center, Room 3334, EPA WJC West Building,
1301 Constitution Avenue 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.
    Instructions. Direct your comments to Docket ID No. EPA-HQ-OAR-
2017-0358. The EPA's policy is that all comments received will be
included in the public docket without change and may be made available
online at http://www.regulations.gov, including any personal
information provided, unless the comment includes information claimed
to be 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. This
type of information should be submitted by mail as discussed in section
I.C of this preamble. 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
not include special characters or 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/dockets.
    Preamble Acronyms and Abbreviations. We use multiple acronyms and
terms in this preamble. While this list may not be exhaustive, to ease
the reading of this preamble and for reference purposes, the EPA
defines the following terms and acronyms here:

AEGL acute exposure guideline level
AERMOD air dispersion model used by the HEM-3 model
CAA Clean Air Act
CalEPA California EPA
CBI Confidential Business Information
CFR Code of Federal Regulations
CIIT Chemical Industry Institute of Toxicology
EPA Environmental Protection Agency
ERPG Emergency Response Planning Guideline
FMM friction materials manufacturing
HAP hazardous air pollutant(s)
HCl hydrochloric acid
HEM-3 Human Exposure Model, Version 1.1.0
HF hydrogen fluoride
HI hazard index
HQ hazard quotient
IRIS Integrated Risk Information System
km kilometer
MACT maximum achievable control technology
mg/m\3\ milligrams per cubic meter
MIR maximum individual risk
NAICS North American Industry Classification System
NAS National Academy of Sciences
NESHAP national emission standards for hazardous air pollutants
NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OMB Office of Management and Budget
PB-HAP hazardous air pollutants known to be persistent and bio-
accumulative in the environment
ppm parts per million
REL reference exposure level
RFA Regulatory Flexibility Act
RfC reference concentration
RfD reference dose
RTR residual risk and technology review
SAB Science Advisory Board
SSM startup, shutdown, and malfunction
TOSHI target organ-specific hazard index
tpy tons per year
TTN Technology Transfer Network
UF uncertainty factor
UMRA Unfunded Mandates Reform Act
URE unit risk estimate
VCS voluntary consensus standards

    Organization of This Document. The information in this preamble is
organized as follows:

I. General Information
    A. Does this action apply to me?
    B. Where can I get a copy of this document and other related
information?
    C. What should I consider as I prepare my comments for the EPA?
II. Background
    A. What is the statutory authority for this action?
    B. What is this source category and how does the current NESHAP
regulate its HAP emissions?
    C. What data collection activities were conducted to support
this action?
    D. What other relevant background information and data are
available?
III. Analytical Procedures
    A. How do we consider risk in our decision-making?
    B. How do we perform the technology review?
    C. How did we estimate post-MACT risks posed by the source
category?
IV. Analytical Results and Proposed Decisions
    A. What are the results of the risk assessment and analyses?
    B. What are our proposed decisions regarding risk acceptability,
ample margin of safety, and adverse environmental effects?
    C. What are the results and proposed decisions based on our
technology review?

    D. What other actions are we proposing?
    E. What compliance dates are we proposing?
V. Summary of Cost, Environmental, and Economic Impacts
    A. What are the affected sources?
    B. What are the air quality impacts?
    C. What are the cost impacts?
    D. What are the economic impacts?
    E. What are the benefits?
VI. Request for Comments
VII. Submitting Data Corrections
VIII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Executive Order 13771: Reducing Regulation and Controlling
Regulatory Costs
    C. Paperwork Reduction Act (PRA)
    D. Regulatory Flexibility Act (RFA)
    E. Unfunded Mandates Reform Act (UMRA)
    F. Executive Order 13132: Federalism
    G. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
    H. Executive Order 13045: Protection of Children From
Environmental Health Risks and Safety Risks
    I. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
    J. National Technology Transfer and Advancement Act (NTTAA)
    K. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations

I. General Information

A. Does this action apply to me?

    Table 1 of this preamble lists the NESHAP and associated regulated
industrial source categories that are the subject of this proposal.
Table 1 is not intended to be exhaustive, but rather provides a guide
for readers regarding the entities that this proposed action is likely
to affect. The proposed standards, once promulgated, will be directly
applicable to the affected sources. Federal, state, local, and tribal
government entities would not be affected by this proposed action. As
defined in the Initial List of Categories of Sources Under Section
112(c)(1) of the Clean Air Act Amendments of 1990 (see 57 FR 31576,
July 16, 1992), the Friction Materials Manufacturing Facilities source
category, which for the remainder of this document will be referred to
as Friction Materials Manufacturing or FMM, was initially defined as
any facility engaged in the manufacture or remanufacture of friction
products, including automobile brake linings and disc pads. Hazardous
air pollutants (HAP) are emitted from solvents added during the
proportioning and mixing of raw materials and the solvents contained in
the adhesives used to bond the linings to the brake shoes. Most HAP
emissions occur during heated processes such as curing, bonding and
debonding processes. The 1992 initial list of identified HAP from
friction products facilities were phenol, toluene, methyl chloroform,
and methyl ethyl (which is no longer listed as a HAP (see 70 FR 75059,
December 19, 2005)). In 2002, the source category definition was
amended (see 67 FR 64497, October 18, 2002) to define a FMM facility as
a facility that manufactures friction materials using a solvent-based
process. Friction materials are used in the manufacture of products
used to accelerate or decelerate objects. Products that use friction
materials include, but are not limited to, disc brake pucks, disc brake
pads, brake linings, brake shoes, brake segments, brake blocks, brake
discs, clutch facings, and clutches.

    Table 1--NESHAP and Industrial Source Categories Affected by This
                             Proposed Action
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    Source  category              NESHAP              NAICS code \1\
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Industry................  Friction Materials      33634, 327999, 333613.
                           Manufacturing.
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\1\ North American Industry Classification System.

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

    In addition to being available in the docket, an electronic copy of
this action is available on the internet. Following signature by the
EPA Administrator, the EPA will post a copy of this proposed action at
http://www.epa.gov/stationary-sources-air-pollution/friction-materials-manufacturing-facilities-national-emission. Following publication in
the Federal Register, the EPA will post the Federal Register version of
the proposal and key technical documents at this same website.
Information on the overall RTR program is available at http://www3.epa.gov/ttn/atw/rrisk/rtrpg.html.
    A redline version of the regulatory language that incorporates the
proposed changes in this action is available in the docket for this
action (Docket ID No. EPA-HQ-OAR-2017-0358).

C. 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 comments that includes information claimed
as CBI, you must submit a copy of the comments that does not contain
the information claimed as CBI 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 Code of Federal Regulations (CFR) part 2. Send or deliver
information identified as CBI only to the following address: OAQPS
Document Control Officer (C404-02), OAQPS, U.S. Environmental
Protection Agency, Research Triangle Park, North Carolina 27711,
Attention Docket ID No. EPA-HQ-OAR-2017-0358.

II. Background

A. What is the statutory authority for this action?

    The statutory authority for this action is provided by sections 112
and 301 of the CAA, as amended (42 U.S.C. 7401 et seq.). Section 112 of
the CAA establishes a two-stage regulatory process to develop standards
for emissions of HAP from stationary sources. Generally, the first
stage involves establishing technology-based standards and the second
stage involves evaluating these standards that are based on maximum
achievable control technology (MACT) to determine whether additional
standards are needed to further address any remaining risk associated
with HAP emissions. This second stage is commonly referred to as the
``residual risk review.'' In addition to the residual risk review, the
CAA also requires the EPA to review standards set under CAA section 112
every 8 years to determine if there are ``developments in practices,
processes, or control technologies'' that may be appropriate to
incorporate into the standards. This review is commonly referred to as
the ``technology review.'' When the two reviews are combined into a
single rulemaking, it is commonly referred to as the ``risk and
technology review.'' The discussion that follows identifies the most
relevant statutory sections and briefly explains the contours of the
methodology used to

implement these statutory requirements. A more comprehensive discussion
appears in the document, CAA Section 112 Risk and Technology Reviews:
Statutory Authority and Methodology, which is in the docket for this
rulemaking.
    In the first stage of the CAA section 112 standard setting process,
the EPA promulgates technology-based standards under CAA section 112(d)
for categories of sources identified as emitting one or more of the HAP
listed in CAA section 112(b). Sources of HAP emissions are either major
sources or area sources, and CAA section 112 establishes different
requirements for major source standards and area source standards.
``Major sources'' are those that emit or have the potential to emit 10
tons per year (tpy) or more of a single HAP or 25 tpy or more of any
combination of HAP. All other sources are ``area sources.'' For major
sources, CAA section 112(d) provides that the technology-based NESHAP
must reflect the maximum degree of emission reductions of HAP
achievable (after considering cost, energy requirements, and non-air
quality health and environmental impacts). These standards are commonly
referred to as MACT standards. CAA section 112(d)(3) also establishes a
minimum control level for MACT standards, known as the MACT ``floor.''
The EPA must also consider control options that are more stringent than
the floor. Standards more stringent than the floor are commonly
referred to as beyond-the-floor standards. In certain instances, as
provided in CAA section 112(h), the EPA may set work practice standards
where it is not feasible to prescribe or enforce a numerical emission
standard. For area sources, CAA section 112(d)(5) gives the EPA
discretion to set standards based on generally available control
technologies or management practices (GACT standards) in lieu of MACT
standards.
    The second stage in standard-setting focuses on identifying and
addressing any remaining (i.e., ``residual'') risk according to CAA
section 112(f). Section 112(f)(2) of the CAA requires the EPA to
determine for source categories subject to MACT standards whether
promulgation of additional standards is needed to provide an ample
margin of safety to protect public health or to prevent an adverse
environmental effect. Section 112(d)(5) of the CAA provides that this
residual risk review is not required for categories of area sources
subject to GACT standards. Section 112(f)(2)(B) of the CAA further
expressly preserves the EPA's use of the two-step process for
developing standards to address any residual risk and the Agency's
interpretation of ``ample margin of safety'' developed in the
``National Emissions 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 EPA notified Congress in the Risk Report that the Agency intended
to use the Benzene NESHAP approach in making CAA section 112(f)
residual risk determinations (EPA-453/R-99-001, p. ES-11). The EPA
subsequently adopted this approach in its residual risk determinations
and the United States Court of Appeals for the District of Columbia
Circuit (the Court) upheld the EPA's interpretation that CAA section
112(f)(2) incorporates the approach established in the Benzene NESHAP.
See NRDC v. EPA, 529 F.3d 1077, 1083 (D.C. Cir. 2008).
    The approach incorporated into the CAA and used by the EPA to
evaluate residual risk and to develop standards under CAA section
112(f)(2) is a two-step approach. 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)
\1\ of approximately [1-in-10 thousand] [i.e., 100-in-1 million].'' 54
FR 38045, September 14, 1989. If risks are unacceptable, the EPA must
determine the emissions standards necessary to bring risks to an
acceptable level without considering costs. In the second step of the
approach, the EPA considers whether the emissions standards provide 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. The EPA must
promulgate emission standards necessary to provide an ample margin of
safety to protect public health. After conducting the ample margin of
safety analysis, we consider whether a more stringent standard is
necessary to prevent, taking into consideration costs, energy, safety,
and other relevant factors, an adverse environmental effect.
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    \1\ Although defined as ``maximum individual risk,'' MIR refers
only to cancer risk. MIR, one metric for assessing cancer risk, is
the estimated risk if an individual were exposed to the maximum
level of a pollutant for a lifetime.
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    CAA section 112(d)(6) separately requires the EPA to review
standards promulgated under CAA section 112 and revise them ``as
necessary (taking into account developments in practices, processes,
and control technologies)'' no less frequently than every 8 years. In
conducting this so-called ``technology review,'' the EPA is not
required to recalculate the MACT floor. Natural Resources Defense
Council (NRDC) v. EPA, 529 F.3d 1077, 1084 (DC Cir. 2008). Association
of Battery Recyclers, Inc. v. EPA, 716 F.3d 667 (DC Cir. 2013). The EPA
may consider cost in deciding whether to revise the standards pursuant
to CAA 112(d)(6).

B. What is this source category and how does the current NESHAP
regulate its HAP emissions?

    Only facilities that are major sources of HAP emissions are subject
to the FMM NESHAP; area sources of HAP are not subject to the rule. The
NESHAP for this source category is codified in 40 CFR part 63, subpart
QQQQQ. The HAP emitted by FMM include formaldehyde, methanol, hexane,
and phenol. Formaldehyde has the potential to cause chronic cancer and
noncancer health effects. The other three HAP are noncarcinogenic and
have the potential for chronic and acute noncancer health effects. In
2017, there were two FMM facilities that were subject to the NESHAP.
    The affected sources at FMM facilities are the solvent mixing
operations as defined in 40 CFR 63.9565. Solvent Mixing Operations are
subject to 40 CFR part 63, subpart QQQQQ, emission limits. Current
emission limits address large and small solvent mixers. New,
reconstructed, and existing large solvent mixers must limit HAP solvent
emissions to the atmosphere to no more than 30 percent of that which
would otherwise be emitted in the absence of solvent recovery and/or
solvent substitution, based on a 7-day block average (see 40 CFR
63.9500(a)). New, reconstructed, and existing small solvent mixers must
limit HAP solvent emissions to the atmosphere to no more than 15
percent of that which would otherwise be emitted in the absence of
solvent recovery and/or solvent substitution, based on a 7-day block
average (see 40 CFR 63.9500(b)).

C. What data collection activities were conducted to support this
action?

    There are two FMM facilities subject to 40 CFR part 63, subpart
QQQQQ. The EPA visited both facilities during the development of the
NESHAP. We visited Railroad Friction Products Corporation (RFPC) in
Maxton, NC, in August 2016, and Knowlton Technologies, LLC, in
Watertown, NY,

in November 2016. During the visits, we discussed quantity and size of
solvent mixers at each site and associated emission points, process
controls, monitors, unregulated emissions, and other aspects of
facility operations. We attached a questionnaire to the site visit
letter and discussed the questionnaire during both site visits. We used
the information provided by the facilities to help create the modeling
file, as well as profile the sector. The site visit reports are
documented in the following memoranda, which are available in the
docket for this action: ``Site Visit Report-Railroad Friction
Products'' and ``Site Visit Report-Knowlton Technologies, LLC.''

D. What other relevant background information and data are available?

    The EPA used information from the Reasonably Available Control
Technology (RACT), Best Available Control Technology (BACT), and Lowest
Achievable Emission Rate (LAER) Clearinghouse (RBLC) database, reviewed
title V permits for each FMM facility, and reviewed regulatory actions
related to emissions controls at similar sources that could be
applicable to FMM. The EPA reviewed the RBLC to identify potential
additional control technologies. No additional control technologies
applicable to FMM were found using the RBLC; see sections III.C and
IV.C of this preamble and the memorandum, ``Technology Review for the
Friction Materials Manufacturing Facilities Source Category,'' which is
available in the docket for this action, for further details on this
source of information.

III. Analytical Procedures

    In this section, we describe the analyses performed to support the
proposed decisions for the RTR and other issues addressed in this
proposal.

A. How do we consider risk in our decision-making?

    As discussed in section II.A of this preamble and in the Benzene
NESHAP, in evaluating and developing standards under CAA section
112(f)(2), we apply a two-step process to determine whether or not
risks are acceptable and to determine if the standards provide an ample
margin of safety to protect public health. As explained in the Benzene
NESHAP, ``the first step judgment on acceptability cannot be reduced to
any single factor'' and, thus, ``[t]he Administrator believes that the
acceptability of risk under section 112 is best judged on the basis of
a broad set of health risk measures and information.'' 54 FR 38046,
September 14, 1989. Similarly, with regard to the ample margin of
safety determination, ``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 Benzene NESHAP approach provides flexibility regarding factors
the EPA may consider in making determinations and how the EPA may weigh
those factors for each source category. The EPA conducts a risk
assessment that provides estimates of the MIR posed by the HAP
emissions from each source in the source category, the hazard index (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.\2\ The assessment
also provides estimates of the distribution of cancer risks within the
exposed populations, cancer incidence, and an evaluation of the
potential for adverse environmental effects. The scope of the EPA's
risk analysis is consistent with the EPA's response to comment on our
policy under the Benzene NESHAP where the EPA explained that:
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    \2\ The MIR is defined as the cancer risk associated with a
lifetime of exposure at the highest concentration of HAP where
people are likely to live. The HQ is the ratio of the potential
exposure to the HAP to the level at or below which no adverse
chronic noncancer effects are expected; the HI is the sum of HQs for
HAP that affect the same target organ or organ system.

[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
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appropriate to determining what will `protect the public health'.

See 54 FR 38057, September 14, 1989. Thus, 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 one in 10
thousand should ordinarily be the upper end of the range of
acceptability. As risks increase above this benchmark, they become
presumptively less acceptable under CAA section 112, and would be
weighed with the other health risk measures and information in making
an overall judgment on acceptability. Or, the Agency may find, in a
particular case, that a risk that includes MIR less than the
presumptively acceptable level is unacceptable in the light of other
health risk factors.'' Id. at 38045. Similarly, with regard to the
ample margin of safety analysis, the EPA stated in the Benzene NESHAP
that: ``EPA believes the relative weight of the many factors that can
be considered in selecting an ample margin of safety can only be
determined for each specific source category. This occurs mainly
because technological and economic factors (along with the health-
related factors) vary from source category to source category.'' Id. at
38061. We also consider the uncertainties associated with the various
risk analyses, as discussed earlier in this preamble, in our
determinations of acceptability, and ample margin of safety.
    The EPA notes that it has not considered certain health information
to date in making residual risk determinations. 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
under review, mobile source emissions, natural source emissions,
persistent environmental pollution, or atmospheric transformation in
the vicinity of the sources in the category.
    The EPA 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. We recognize
that such consideration may be particularly important when assessing
noncancer risks, where pollutant-specific exposure health reference
levels (e.g., reference concentrations (RfCs)) are based on the
assumption that thresholds exist for adverse health effects. For
example, the EPA recognizes that, although exposures attributable to
emissions from a source category or facility alone may not indicate the
potential for increased risk of adverse noncancer 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 noncancer health effects. In May 2010, the Science
Advisory Board (SAB) advised the EPA ``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.'' \3\
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    \3\ 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/4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-
007-unsigned.pdf) are outlined in a memorandum to this rulemaking
docket from David Guinnup titled EPA's Actions in Response to the
Key Recommendations of the SAB Review of RTR Risk Assessment
Methodologies.
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    In response to the SAB recommendations, the EPA is incorporating
cumulative risk analyses into its RTR risk assessments, including those
reflected in this proposal. The Agency is (1) conducting facility-wide
assessments, which include source category emission points, as well as
other emission points within the facilities; (2) combining exposures
from multiple sources in the same category that could affect the same
individuals; and (3) for some persistent and bioaccumulative
pollutants, analyzing the ingestion route of exposure. In addition, the
RTR risk assessments have always considered aggregate cancer risk from
all carcinogens and aggregate noncancer HI from all non-carcinogens
affecting the same target organ system.
    Although we are interested in placing source category and facility-
wide HAP risks in the context of total HAP risks from all sources
combined in the vicinity of each source, we are concerned about the
uncertainties of doing so. Because of the contribution to total HAP
risk from emission sources other than those that we have studied in
depth during this RTR review, such estimates of total HAP risks would
have significantly greater associated uncertainties than the source
category or facility-wide estimates. Such aggregate or cumulative
assessments would compound those uncertainties, making the assessments
too unreliable.

B. How do we perform the technology review?

    Our technology review focuses on the identification and evaluation
of developments in practices, processes, and control technologies that
have occurred since the MACT standards were promulgated. Where we
identify such developments, in order to inform our decision of whether
it is ``necessary'' to revise the emissions standards, we analyze the
technical feasibility of applying these developments and the estimated
costs, energy implications, and non-air environmental impacts, and we
also consider the emission reductions. In addition, we considered the
appropriateness of applying controls to new sources versus retrofitting
existing sources. For this exercise, we consider 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 original MACT
standards;
     Any improvements in add-on control technology or other
equipment (that were identified and considered during development of
the original MACT standards) that could result in additional emissions
reduction;
     Any work practice or operational procedure that was not
identified or considered during development of the original MACT
standards;
     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 original MACT
standards; and
     Any significant changes in the cost (including cost
effectiveness) of applying controls (including controls the EPA
considered during the development of the original MACT standards).
    In addition to reviewing the practices, processes, and control
technologies that were considered at the time we originally developed
(or last updated) the NESHAP, we reviewed a variety of data sources in
our investigation of potential practices, processes, or controls to
consider. Among the sources we reviewed were the NESHAP for various
industries that were promulgated since the MACT standards being
reviewed in this action. 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 be applied to emission sources in the FMM 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 information from other sources, such as state and/or local
permitting agency databases and industry-supported databases.

C. How did we estimate post-MACT risks posed by the source category?

    The EPA conducted a risk assessment that provides estimates of the
MIR for cancer posed by the HAP emissions from each source in the
source category, the HI for chronic exposures to HAP with the potential
to cause noncancer health effects, and the HQ for acute exposures to
HAP with the potential to cause noncancer health effects. The
assessment also provides estimates of the distribution of cancer risks
within the exposed populations, cancer incidence, and an evaluation of
the potential for adverse environmental effects. The seven sections
that follow this paragraph describe how we estimated emissions and
conducted the risk assessment. The docket for this action contains the
following document which provides more information on the risk
assessment inputs and models: Residual Risk Assessment for the Friction
Materials Manufacturing Source Category in Support of the February 2018
Risk and Technology Review Proposed Rule. The methods used to assess
risks (as described in the seven primary steps below) are consistent
with those peer-reviewed by a panel of the EPA's SAB in 2009 and
described in their peer review report issued in 2010; \4\ they are also
consistent with the key recommendations contained in that report.
---------------------------------------------------------------------------

    \4\ 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.
---------------------------------------------------------------------------

1. How did we estimate actual emissions and identify the emissions
release characteristics?
    Solvent mixers are the primary emission source at FMM facilities.
Actual emissions for RFPC, which utilizes a solvent recovery system,
are estimated using mass balance calculations from the solvent storage
tanks. All solvent not recovered is assumed to be emitted.
    Potential HAP emissions at Knowlton Technologies, LLC, are captured
by a permanent total enclosure and ducted to a boiler for destruction.
The potential HAP emissions at Knowlton come from resins/solvents used
in the saturator process line, including the resin kitchen. Annual
potential emissions of formaldehyde, methanol, and phenol were
calculated by using the annual purchasing total of resins/solvents that
contain HAP, multiplied by the maximum percent of HAP contained in the
resin/solvent to provide a conservative estimate of potential

emissions. The potential emissions are controlled by a permanent total
enclosure with a capture efficiency of 100 percent, which routes the
potential emissions to a boiler. Data from emissions testing conducted
in January 2003 were used to determine the boiler destruction
efficiencies for a select group of organic compounds, including
formaldehyde, methanol, and phenol. Pollutant-specific boiler control
efficiencies were used to calculate post control device emissions to
the atmosphere. Additional details on the data and methods used to
develop actual emissions estimates for the risk modeling are provided
in the memorandum, ``Development of the Risk Modeling Dataset,'' which
is available in the docket for this action.
2. How did we estimate MACT-allowable emissions?
    The available emissions data in the RTR emissions dataset include
estimates of the mass of HAP emitted during a specified annual time
period. These ``actual'' emission levels are often lower than the
emission levels allowed under the requirements of the current MACT
standards. The emissions level allowed to be emitted by the MACT
standards is referred to as the ``MACT-allowable'' emissions level. We
discussed the use of both MACT-allowable and actual emissions in the
final Coke Oven Batteries RTR (70 FR 19998-19999, April 15, 2005) and
in the proposed and final Hazardous Organic NESHAP RTRs (71 FR 34428,
June 14, 2006, and 71 FR 76609, December 21, 2006, respectively). In
those actions, we noted that assessing the risks at the MACT-allowable
level is inherently reasonable since these risks reflect the maximum
level facilities could emit and still comply with national emission
standards. 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 approach. (54 FR 38044,
September 14, 1989.)
    For FMM, we calculated allowable emissions differently for each
facility. For RFPC, we determined that allowable emissions are equal to
actual emissions because the facility uses both solvent recovery and
solvent substitution to comply with the MACT standard. Solvent
substitution credits the facility for 100-percent recovery on every
batch that doesn't require the use of a HAP solvent. Batch operations
using solvent substitution, thus credited for 100-percent recovery, are
then averaged with the batches using solvent recovery, to calculate the
facility-wide average recovery percentage. That is to say, if the
facility ran 10 batches using solvent substitution, credited as 100-
percent recovery, and 10 batches using solvent recovery, which achieved
50-percent recovery of the HAP solvent used, the facility would have an
average of 75-percent recovery. These calculations show why using the
method of calculating allowable emissions by setting them equal to the
minimum requirements to comply with the rule (70- percent recovery)
does not accurately quantify this source category. The resulting
emissions if each facility calculated each batch to emit at 70-percent
would result in actual emissions exceeding allowable emissions due to
the credited solvent substitution. As a result, we have decided to set
actual emissions equal to allowable emissions to better quantify
facility emissions. Allowable emissions for Knowlton Technologies, LLC,
were calculated by setting the destruction efficiency at 70-percent to
comply with the MACT standard instead of the >99-percent currently
estimated by the facility. By setting the destruction efficiency to 70-
percent, we can estimate the amount of HAP released if the facility
were to meet the minimum requirements for compliance with the MACT
standard. Additional details on the data and methods used to develop
MACT-allowable emissions for the risk modeling are provided in the
memorandum, ``Development of the Risk Modeling Dataset,'' which is
available in the docket for this action.
3. How did we conduct dispersion modeling, determine inhalation
exposures, and estimate individual and population inhalation risks?
    Both long-term and short-term inhalation exposure concentrations
and health risks from the source category addressed in this proposal
were estimated using the Human Exposure Model (HEM-3). 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 kilometers (km) of the modeled sources,
and (3) estimating individual and population-level inhalation risks
using the exposure estimates and quantitative dose-response
information.
a. Dispersion Modeling
    The air dispersion model AERMOD, used by the HEM-3 model, is one of
the EPA's preferred models for assessing air pollutant concentrations
from industrial facilities.\5\ 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 (2016) of
hourly surface and upper air observations from 824 meteorological
stations, selected to provide coverage of the United States and Puerto
Rico. A second library of United States Census Bureau census block \6\
internal point locations and populations provides the basis of human
exposure calculations (U.S. Census, 2010). 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-specific dose-response values is used to estimate health
risks. These dose-response values are the latest values recommended by
the EPA for HAP. They are available at https://www.epa.gov/fera/dose-response-assessment-assessing-health-risks-associated-exposure-hazardous-air-pollutants and are discussed in more detail later in this
section.
---------------------------------------------------------------------------

    \5\ 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).
    \6\ A census block is the smallest geographic area for which
census statistics are tabulated.
---------------------------------------------------------------------------

b. Risk From Chronic Exposure to HAP That May Cause Cancer
    In developing the risk assessment for chronic exposures, we used
the estimated annual average ambient air concentrations of each 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, 52 weeks per
year, for a 70-year period) exposure to the maximum concentration at
the centroid of inhabited census blocks. Individual cancer risks were
calculated by multiplying the estimated lifetime exposure to the
ambient concentration of each HAP (in micrograms per cubic meter) by
its unit risk estimate (URE). The URE 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 UREs from
the EPA's Integrated Risk Information System (IRIS). For carcinogenic
pollutants without IRIS values, we look to other reputable sources of
cancer dose-response values, often using California EPA (CalEPA) UREs,
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.
    In 2004, the EPA determined that the Chemical Industry Institute of
Toxicology (CIIT) cancer dose-response value for formaldehyde (5.5 x
10-9 milligrams per cubic meter (mg/m\3\)) was based on
better science than the 1991 IRIS dose-response value (1.3 x
10-5 per mg/m\3\) and, we switched from using the IRIS value
to the CIIT value in risk assessments supporting regulatory actions.
Based on subsequent published research, however, the EPA changed its
determination regarding the CIIT model, and, in 2010, the EPA returned
to using the 1991 IRIS value. The National Academy of Sciences (NAS)
completed its review of the EPA's draft assessment in April of 2011
(http://www.nap.edu/catalog.php?record id=13142), and the EPA has been
working on revising the formaldehyde assessment. The EPA will follow
the NAS Report recommendations and will present results obtained by
implementing the biologically based dose response (BBDR) model for
formaldehyde. The EPA will compare these estimates with those currently
presented in the External Review draft of the assessment and will
discuss their strengths and weaknesses. As recommended by the NAS
committee, appropriate sensitivity and uncertainty analyses will be an
integral component of implementing the BBDR model. The draft IRIS
assessment will be revised in response to the NAS peer review and
public comments and the final assessment will be posted on the IRIS
database. In the interim, we will present findings using the 1991 IRIS
value as a primary estimate and may also consider other information as
the science evolves.
    To estimate incremental individual lifetime cancer risks associated
with emissions from the facilities in the source category, the EPA
summed the risks for each of the carcinogenic HAP \7\ emitted by the
modeled sources. Cancer incidence and the distribution of individual
cancer risks for the population within 50 km of the sources were also
estimated for the source category by summing individual risks. A
distance of 50 km is consistent with both the analysis supporting the
1989 Benzene NESHAP (54 FR 38044, September 14, 1989) and the
limitations of Gaussian dispersion models, including AERMOD.
---------------------------------------------------------------------------

    \7\ The EPA classifies carcinogens as: Carcinogenic to humans,
likely to be carcinogenic to humans, and suggestive evidence of
carcinogenic potential. These classifications also coincide with the
terms ``known carcinogen, probable carcinogen, and possible
carcinogen,'' respectively, which are the terms advocated in the
EPA's Guidelines for Carcinogen Risk Assessment, published in 1986
(51 FR 33992, September 24, 1986). In August 2000, the document,
Supplemental Guidance for Conducting Health Risk Assessment of
Chemical Mixtures (EPA/630/R-00/002), was published as a supplement
to the 1986 document. Copies of both documents can be obtained from
https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=20533&CFID=70315376&CFTOKEN=71597944. 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 the EPA's National Air Toxics Assessment
(NATA) titled NATA--Evaluating the National-scale Air Toxics
Assessment 1996 Data--an SAB Advisory, available at http://
yosemite.epa.gov/sab/sabproduct.nsf/
214C6E915BB04E14852570CA007A682C/$File/ecadv02001.pdf.
---------------------------------------------------------------------------

c. Risk From Chronic Exposure to HAP That May Cause Health Effects
Other Than Cancer
    To assess the risk of noncancer health effects from chronic
exposure to HAP, we calculate either an HQ or a target organ-specific
hazard index (TOSHI). We calculate an HQ when a single noncancer HAP is
emitted. Where more than one noncancer HAP is emitted, we sum the HQ
for each of the HAP that affects a common target organ system to obtain
a TOSHI. The HQ is the estimated exposure divided by the chronic
noncancer dose-response value, which is a value selected from one of
several sources. The preferred chronic noncancer dose-response value is
the EPA RfC (https://iaspub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&vocabName=IRIS%20Glossary), 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.'' In cases where an RfC from
the EPA's IRIS database is not available or where the EPA determines
that using a value other than the RfC is appropriate, the chronic
noncancer dose-response value can be obtained from the following
prioritized sources, which define their dose-response values similarly
to the EPA: (1) The Agency for Toxic Substances and Disease Registry
(ATSDR) Minimum Risk Level (http://www.atsdr.cdc.gov/mrls/index.asp);
(2) the CalEPA Chronic Reference Exposure Level (REL) (http://oehha.ca.gov/air/crnr/notice-adoption-air-toxics-hot-spots-program-guidance-manual-preparation-health-risk-0); 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.
d. Risk From Acute Exposure to HAP That May Cause Health Effects Other
Than Cancer
    For each HAP for which appropriate acute inhalation dose-response
values are available, the EPA also assesses the potential health risks
due to acute exposure. For these assessments, the EPA makes
conservative assumptions about emission rates, meteorology, and
exposure location. We use the peak hourly emission rate,\8\ worst-case
dispersion conditions, and, in accordance with our mandate under
section 112 of the CAA, the point of highest off-site exposure to
assess the potential risk to the maximally exposed individual.
---------------------------------------------------------------------------

    \8\ In the absence of hourly emission data, we develop estimates
of maximum hourly emission rates by multiplying the average actual
annual emissions rates by a default factor (usually 10) to account
for variability. This is documented in Residual Risk Assessment for
the Friction Materials Manufacturing Facilities Source Category in
Support of the March 2018 Risk and Technology Review Proposed Rule
and in Appendix 5 of the report: Analysis of Data on Short-term
Emission Rates Relative to Long-term Emission Rates. Both are
available in the docket for this rulemaking.
---------------------------------------------------------------------------

    To characterize the potential health risks associated with
estimated acute inhalation exposures to a HAP, we generally use
multiple acute dose-response values, including acute RELs, acute
exposure guideline levels (AEGLs), and emergency response planning
guidelines (ERPG) for 1-hour exposure durations), if available, to
calculate acute HQs. The acute HQ is calculated by dividing the
estimated acute exposure by the acute dose-response value. For each HAP
for which acute dose-response values are available, the EPA calculates
acute HQs.
    An acute REL is defined as ``the concentration level at or below
which no adverse health effects are anticipated for a specified
exposure duration. '' \9\

Acute RELs are based on the most sensitive, relevant, adverse health
effect reported in the peer-reviewed medical and toxicological
literature. They are designed to protect the most sensitive individuals
in the population through the inclusion of margins of safety. Because
margins of safety are incorporated to address data gaps and
uncertainties, exceeding the REL does not automatically indicate an
adverse health impact. AEGLs represent threshold exposure limits for
the general public and are applicable to emergency exposures ranging
from 10 minutes to 8 hours.\10\ They are guideline levels for ``once-
in-a-lifetime, short-term exposures to airborne concentrations of
acutely toxic, high-priority chemicals.'' Id. at 21. The AEGL-1 is
specifically defined as ``the airborne concentration (expressed as ppm
(parts per million) or mg/m\3\ (milligrams per cubic meter)) of a
substance above which it is predicted that the general population,
including susceptible individuals, could experience notable discomfort,
irritation, or certain asymptomatic non-sensory effects. However, the
effects are not disabling and are transient and reversible upon
cessation of exposure.'' Airborne concentrations below AEGL-1 represent
exposure levels that can produce mild and progressively increasing, but
transient and non-disabling odor, taste, and sensory irritation or
certain asymptomatic, non-sensory effects.'' Id. AEGL-2 are defined as
``the airborne concentration (expressed as parts per million or
milligrams per cubic meter) 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.'' Id.
---------------------------------------------------------------------------

    \9\ CalEPA issues acute RELs as part of its Air Toxics Hot Spots
Program, and the 1-hour and 8-hour values are documented in Air
Toxics Hot Spots Program Risk Assessment Guidelines, Part I, The
Determination of Acute Reference Exposure Levels for Airborne
Toxicants, which is available at http://oehha.ca.gov/air/general-info/oehha-acute-8-hour-and-chronic-reference-exposure-level-rel-summary.
    \10\ NAS, 2001. Standing Operating Procedures for Developing
Acute Exposure Levels for Hazardous Chemicals, page 2. Available at
https://www.epa.gov/sites/production/files/2015-09/documents/sop_final_standing_operating_procedures_2001.pdf. Note that the
National Advisory Committee for Acute Exposure Guideline Levels for
Hazardous Substances ended in October 2011, but the AEGL program
continues to operate at the EPA and works with the National
Academies to publish final AEGLs, (https://www.epa.gov/aegl).
---------------------------------------------------------------------------

    ERPGs are developed for emergency planning and are intended as
health-based guideline concentrations for single exposures to
chemicals.'' \11\ Id. at 1. The ERPG-1 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.'' Id. at 2. Similarly, the ERPG-
2 is defined as ``the maximum airborne concentration below which it is
believed that nearly all individuals could be exposed for up to one
hour without experiencing or developing irreversible or other serious
health effects or symptoms which could impair an individual's ability
to take protective action.'' Id. at 1.
---------------------------------------------------------------------------

    \11\ ERPGS Procedures and Responsibilities. March 2014. American
Industrial Hygiene Association. Available at: https://www.aiha.org/get-involved/AIHAGuidelineFoundation/EmergencyResponsePlanningGuidelines/Documents/ERPG%20Committee%20Standard%20Operating%20Procedures%20%20-%20March%202014%20Revision%20%28Updated%2010-2-2014%29.pdf.
---------------------------------------------------------------------------

    An acute REL for 1-hour exposure durations is typically lower than
its corresponding AEGL-1 and ERPG-1. Even though their definitions are
slightly different, AEGL-1s are often the same as the corresponding
ERPG-1s, and AEGL-2s are often equal to ERPG-2s. The maximum HQs from
our acute inhalation screening risk assessment typically result when we
use the acute REL for a HAP. In cases where the maximum acute HQ
exceeds 1, we also report the HQ based on the next highest acute dose-
response value (usually the AEGL-1 and/or the ERPG-1).
    For this source category, we used the default multiplication factor
of 10. While we don't anticipate large variations in hourly emissions,
we took a conservative approach to determine if the default
multiplication factor would result in high risk. Upon modeling the
emissions using the multiplication factor of 10, we determined that
risk was still below 1-in-1 million. Due to the low risk results,
further research to justify a lower multiplication factor was not
necessary.
    In our acute inhalation screening risk assessment, acute impacts
are deemed negligible for HAP where acute HQs are less than or equal to
1 (even under the conservative assumptions of the screening
assessment), and no further analysis is performed for these HAP. In
cases where an acute HQ from the screening step is greater than 1, we
consider additional site-specific data to develop a more refined
estimate of the potential for acute impacts of concern. For this source
category, we did not have to perform any refined acute assessments.
4. How did we conduct the multipathway exposure and risk screening
assessment?
    The EPA conducted a tiered screening assessment examining the
potential for significant human health risks due to exposures via
routes other than inhalation (i.e., ingestion). We first determined
whether any sources in the source category emitted any HAP known to be
persistent and bioaccumulative in the environment (PB-HAP), as
identified in the EPA's Air Toxics Risk Assessment Library (available
at http://www2.epa.gov/fera/risk-assessment-and-modeling-air-toxics-risk-assessment-reference-library).
    For the FMM source category, we did not identify emissions of any
PB-HAP. Because we did not identify PB-HAP emissions, no further
evaluation of multipathway risk was conducted for this source category.
5. How did we conduct the environmental risk screening assessment?
a. Adverse Environmental Effects, Environmental HAP, and Ecological
Benchmarks
    The EPA conducts a screening assessment to examine the potential
for adverse environmental effects as required under section
112(f)(2)(A) of the CAA. Section 112(a)(7) of the CAA defines ``adverse
environmental effect'' as ``any significant and widespread adverse
effect, which may reasonably be anticipated, to wildlife, aquatic life,
or other natural resources, including adverse impacts on populations of
endangered or threatened species or significant degradation of
environmental quality over broad areas.''
    The EPA focuses on eight HAP, which are referred to as
``environmental HAP,'' in its screening assessment: Six PB-HAP and two
acid gases. The PB-HAP included in the screening assessment are arsenic
compounds, cadmium compounds, dioxins/furans, polcyclic organic matter,
mercury (both inorganic mercury and methyl mercury), and lead
compounds. The acid gases included in the screening assessment are
hydrochloric acid (HCl) and hydrogen fluoride (HF).
    HAP that persist and bioaccumulate are of particular environmental
concern because they accumulate in the soil, sediment, and water. The
acid gases, HCl and HF, were included due to their well-documented
potential to cause direct damage to terrestrial plants. In the
environmental risk screening assessment, we evaluate the following

four exposure media: Terrestrial soils, surface water bodies (includes
water-column and benthic sediments), fish consumed by wildlife, and
air. Within these four exposure media, we evaluate nine ecological
assessment endpoints, which are defined by the ecological entity and
its attributes. For PB-HAP (other than lead), both community-level and
population-level endpoints are included. For acid gases, the ecological
assessment evaluated is terrestrial plant communities.
    An ecological benchmark represents a concentration of HAP that has
been linked to a particular environmental effect level. For each
environmental HAP, we identified the available ecological benchmarks
for each assessment endpoint. We identified, where possible, ecological
benchmarks at the following effect levels: Probable effect levels,
lowest-observed-adverse-effect level, and no-observed-adverse-effect
level. In cases where multiple effect levels were available for a
particular PB-HAP and assessment endpoint, we use all of the available
effect levels to help us to determine whether ecological risks exist
and, if so, whether the risks could be considered significant and
widespread.
    For further information on how the environmental risk screening
assessment was conducted, including a discussion of the risk metrics
used, how the environmental HAP were identified, and how the ecological
benchmarks were selected, see Appendix 9 of the Residual Risk
Assessment for the Friction Materials Manufacturing Source Category in
Support of the Risk and Technology Review February 2018 Proposed Rule,
which is available in the docket for this action.
b. Environmental Risk Screening Methodology
    For the environmental risk screening assessment, the EPA first
determined whether any of the FMM facilities emitted any of the
environmental HAP. For the FMM source category, we did not identify
emissions of any of the seven environmental HAP included in the screen.
Because we did not identify environmental HAP emissions, no further
evaluation of environmental risk was conducted.
6. How did we conduct facility-wide assessments?
    To put the source category risks in context, we 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 other words, we examine the HAP emissions not only from the
source category emission points of interest, but also emissions of HAP
from all other emission sources at the facility for which we have data.
    For this source category, we conducted the facility-wide assessment
using a dataset that the EPA compiled from the 2014 National Emissions
Inventory (NEI). We used the NEI data for the facility and did not
adjust any category or ``non-category'' data. Therefore, there could be
differences in the dataset from that used for the source category
assessments described in this preamble. We analyzed risks due to the
inhalation of HAP that are emitted ``facility-wide'' for the
populations residing within 50 km of each facility, consistent with the
methods used for the source category analysis described above. For
these facility-wide risk analyses, we made a reasonable attempt to
identify the source category risks, and these risks were compared to
the facility-wide risks to determine the portion of facility-wide risks
that could be attributed to the source category addressed in this
proposal. We also specifically examined the facility that was
associated with the highest estimate of risk and determined the
percentage of that risk attributable to the source category of
interest. The Residual Risk Assessment for the Friction Materials
Manufacturing Source Category in Support of the Risk and Technology
Review February 2018 Proposed Rule, available through the docket for
this action, provides the methodology and results of the facility-wide
analyses, including all facility-wide risks and the percentage of
source category contribution to facility-wide risks.
7. How did we consider uncertainties in risk assessment?
    Uncertainty and the potential for bias are inherent in all risk
assessments, including those performed for this proposal. Although
uncertainty exists, we believe that our approach, which used
conservative tools and assumptions, ensures that our decisions are
protective of health and the environment. A brief discussion of the
uncertainties in the RTR emissions dataset, dispersion modeling,
inhalation exposure estimates, and dose-response relationships follows
below. Also included are those uncertainties specific to our acute
screening assessments, multipathway screening assessments, and our
environmental risk screening assessments. A more thorough discussion of
these uncertainties is included in the Residual Risk Assessment for the
FMM Source Category in Support of the Risk and Technology Review
February 2018 Proposed Rule, which is available in the docket for this
action.
a. Uncertainties in the RTR Emissions Dataset
    Although the development of the RTR emissions dataset involved
quality assurance/quality control processes, the accuracy of emissions
values will vary depending on the source of the data, the degree to
which data are incomplete or missing, the degree to which assumptions
made to complete the datasets are accurate, errors in emission
estimates, and other factors. The emission estimates considered in this
analysis generally are annual totals for certain years, and they 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 an
emission adjustment factor applied to the average annual hourly
emission rates, which are intended to account for emission fluctuations
due to normal facility operations.
b. Uncertainties in Dispersion Modeling
    We recognize there is uncertainty in ambient concentration
estimates associated with any model, including the EPA's recommended
regulatory dispersion model, AERMOD. In using a model to estimate
ambient pollutant concentrations, the user chooses certain options to
apply. For RTR assessments, we select some model options that have the
potential to overestimate ambient air concentrations (e.g., not
including plume depletion or pollutant transformation). We select other
model options that have the potential to underestimate ambient impacts
(e.g., not including building downwash). Other options that we select
have the potential to either under- or overestimate ambient levels
(e.g., meteorology and receptor locations). On balance, considering the
directional nature of the uncertainties commonly present in ambient
concentrations estimated by dispersion models, the approach we apply in
the RTR assessments should yield unbiased estimates of ambient HAP
concentrations. We also note that the selection of meteorology dataset
location could have an impact on the risk estimates. As we continue to
update and expand our library of meteorological station data used in
our risk assessments, we expect to reduce this variability.
c. Uncertainties in Inhalation Exposure Assessment
    Although every effort is made to identify all of the relevant
facilities and

emission points, as well as to develop accurate estimates of the annual
emission rates for all relevant HAP, the uncertainties in our emission
inventory likely dominate the uncertainties in the exposure assessment.
Some uncertainties in our exposure assessment include human mobility,
using the centroid of each census block, assuming lifetime exposure,
and assuming only outdoor exposures. For most of these factors, there
is neither an under nor overestimate when looking at the maximum
individual risks or the incidence, but the shape of the distribution of
risks may be affected. With respect to outdoor exposures, actual
exposures may not be as high if people spend time indoors, especially
for very reactive pollutants or larger particles. For all factors, we
reduce uncertainty when possible. For example, with respect to census-
block centroids, we analyze large blocks using aerial imagery and
adjust locations of the block centroids to better represent the
population in the blocks. We also add additional receptor locations
where the population of a block is not well represented by a single
location.
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 are generally expressed quantitatively,
and others are generally expressed in qualitative terms. We note, as a
preface to this discussion, a point on dose-response uncertainty that
is stated in the EPA's 2005 Cancer Guidelines; namely, that ``the
primary goal of EPA actions is protection of human health; accordingly,
as an Agency policy, risk assessment procedures, including default
options that are used in the absence of scientific data to the
contrary, should be health protective'' (EPA's 2005 Cancer Guidelines,
pages 1-7). This is the approach followed here as summarized in the
next paragraphs.
    Cancer UREs 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).\12\ In some circumstances, the true risk could be as low as
zero; however, in other circumstances the risk could be greater.\13\
Chronic noncancer RfC and reference dose (RfD) values represent chronic
exposure levels that are intended to be health-protective levels. To
derive dose-response values that are intended to be ``without
appreciable risk,'' the methodology relies upon an uncertainty factor
(UF) approach (U.S. EPA, 1993 and 1994) which considers uncertainty,
variability, and gaps in the available data. The UFs are applied to
derive dose-response values that are intended to protect against
appreciable risk of deleterious effects.
---------------------------------------------------------------------------

    \12\ IRIS glossary (https://ofmpub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&glossaryName=IRIS%20Glossary).
    \13\ 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.
---------------------------------------------------------------------------

    Many of the UFs used to account for variability and uncertainty in
the development of acute dose-response values are quite similar to
those developed for chronic durations. 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 dose-
response value at another exposure duration (e.g., 1 hour). Not all
acute dose-response 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 dose-response value or values
being exceeded. Where relevant to the estimated exposures, the lack of
acute dose-response values at different levels of severity should be
factored into the risk characterization as potential uncertainties.
    Uncertainty also exists in the selection of ecological benchmarks
for the environmental risk screening assessment. We established a
hierarchy of preferred benchmark sources to allow selection of
benchmarks for each environmental HAP at each ecological assessment
endpoint. We searched for benchmarks for three effect levels (i.e., no-
effects level, threshold-effect level, and probable effect level), but
not all combinations of ecological assessment/environmental HAP had
benchmarks for all three effect levels. Where multiple effect levels
were available for a particular HAP and assessment endpoint, we used
all of the available effect levels to help us determine whether risk
exists and whether the risk could be considered significant and
widespread.
    Although every effort is made to identify appropriate human health
effect dose-response values for all pollutants emitted by the sources
in this risk assessment, some HAP emitted by this source category are
lacking dose-response assessments. Accordingly, these pollutants cannot
be included in the quantitative risk assessment, which could result in
quantitative estimates understating HAP risk. To help to alleviate this
potential underestimate, where we conclude similarity with a HAP for
which a dose-response value is available, we use that value as a
surrogate for the assessment of the HAP for which no value is
available. To the extent use of surrogates indicates appreciable risk,
we may identify a need to increase priority for an IRIS assessment for
that substance. We additionally note that, generally speaking, HAP of
greatest concern due to environmental exposures and hazard are those
for which dose-response assessments have been performed, reducing the
likelihood of understating risk. Further, HAP not included in the
quantitative assessment are assessed qualitatively and considered in
the risk characterization that informs the risk management decisions,
including consideration of HAP reductions achieved by various control
options.
    For a group of compounds that are unspeciated (e.g., glycol
ethers), we conservatively use the most protective dose-response value
of an individual compound in that group to estimate risk. Similarly,
for an individual compound in a group (e.g., ethylene glycol diethyl
ether) that does not have a specified dose-response value, we also
apply the most protective dose-response value from the other compounds
in the group to estimate risk.
e. Uncertainties in Acute Inhalation Screening Assessments
    In addition to the uncertainties highlighted above, there are
several factors specific to the acute exposure assessment that the EPA
conducts as part of the risk review under section 112 of the CAA. 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 the presence of humans
at the location of the maximum concentration. In the acute screening
assessment that we conduct under the RTR program, we assume that peak
emissions from the source category and worst-case meteorological
conditions co-occur, thus, resulting in maximum ambient concentrations.
These two events are unlikely to occur at the same time, making these
assumptions conservative. We then include the additional

assumption that a person is located at this point during this same time
period. For this source category, these assumptions would tend to be
worst-case actual exposures as it is unlikely that a person would be
located at the point of maximum exposure during the time when peak
emissions and worst-case meteorological conditions occur
simultaneously.

IV. Analytical Results and Proposed Decisions

A. What are the results of the risk assessment and analyses?

1. Inhalation Risk Assessment Results
    The inhalation risk modeling performed to estimate risks based on
actual and allowable emissions relied primarily on emissions data
gathered through questionnaires provided during two recent site visits
conducted by the EPA. The EPA discussed specific FMM processes with
authorized representatives of both facilities, including quantity and
size of solvent mixers at each site and associated emission points,
process controls, monitors, unregulated emissions, and other aspects of
facility operations.
    The results of the chronic baseline inhalation cancer risk
assessment indicate that, based on estimates of current actual and
allowable emissions under 40 CFR part 63, subpart QQQQQ, the MIR posed
by the source category is less than 1-in-1 million. The total estimated
cancer incidence based on actual emission levels is 0.000005 excess
cancer cases per year, or 1 case every 200,000 years. The total
estimated cancer incidence based on allowable emission levels is
0.00004 excess cancer cases per year, or 1 case every 25,000 years. Air
emissions of formaldehyde contributed 100 percent to this cancer
incidence. The population exposed to cancer risks greater than or equal
to 1-in-1 million considering actual and allowable emissions is 0 (see
Table 2 of this preamble).

                            Table 2--Inhalation Risk Assessment Summary for Friction Materials Manufacturing Source Category
                                                             [40 CFR part 63, subpart QQQQQ]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                              Cancer  MIR (in 1 million)                             Population      Population
                                    ----------------------------------------------     Cancer       with risk  of   with risk  of       Max  chronic
                                                                                incidence        1-in-1          10-in-1         noncancer  HI
                                        Based on  actual      Based on allowable     (cases per      million  or     million  or        (actuals and
                                           emissions              emissions             year)           more            more            allowables)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Category....................  < 1 (formaldehyde)...  < 1 (formaldehyde)...        0.000005               0               0  HI < 1
Whole Facility.....................  5 (hexavalent          .....................          0.0005           2,300               0  HI < 1
                                      chromium).
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The maximum modeled chronic noncancer HI (TOSHI) values for the
source category based on actual and allowable emissions are estimated
to be 0.01 and 0.02, respectively, with n-hexane emissions from large
solvent mixers accounting for 100 percent of the HI.
1. Acute Risk Results
    Our screening analysis for worst-case acute impacts based on actual
emissions indicates no pollutants exceeding an HQ value of 1 based upon
the REL. The acute hourly multiplier utilized a default factor of 10
for all emission processes.
2. Multipathway Risk Screening Results
    We did not identify any PB-HAP emissions from this source category.
Therefore, we estimate that there is no multipathway risk from HAP
emissions from this source category.
3. Environmental Risk Screening Results
    We did not identify any PB-HAP or acid gas emissions from this
source category. We are unaware of any adverse environmental effect
caused by emissions of HAP that are emitted by the FMM source category.
Therefore, we do not expect an adverse environmental effect as a result
of HAP emissions from this source category.
4. Facility-Wide Risk Results
    Considering facility-wide emissions at the two plants, the MIR is
estimated to be 5-in-1 million driven by hexavalent chromium emissions,
and the chronic noncancer TOSHI value is calculated to be <1 driven by
emissions of nickel and hexavalent chromium (see Table 2 of this
preamble). The above cancer and noncancer risks are driven by emissions
from a miscellaneous industrial process that was not able to be
classified.
    Approximately 2,300 people are estimated to have cancer risks
greater than or equal to 1-in-1 million considering whole facility
emissions from the two facilities in the source category (see Table 2
of this preamble).
6. What demographic groups might benefit from this regulation?
    To examine the potential for any environmental justice issues that
might be associated with the source category, we performed a
demographic analysis, which is an assessment of risks to individual
demographic groups of the populations living within 5 km and within 50
km of the facilities. In the analysis, we evaluated the distribution of
HAP-related cancer and noncancer risks from the FMM source category
across different demographic groups within the populations living near
the two facilities.\14\
---------------------------------------------------------------------------

    \14\ Demographic groups included in the analysis are: White,
African American, Native American, other races and multiracial,
Hispanic or Latino, children 17 years of age and under, adults 18 to
64 years of age, adults 65 years of age and over, adults without a
high school diploma, people living below the poverty level, people
living two times the poverty level, and linguistically isolated
people.
---------------------------------------------------------------------------

    Results of the demographic analysis indicate that, for 3 of the 11
demographic groups, Native American, ages 0-17, and below the poverty
level, the percentage of the population living within 5 km of
facilities in the source category is greater than the corresponding
national percentage for the same demographic groups. When examining the
risk levels of those exposed to emissions from FMM facilities, we find
that no one is exposed to a cancer risk at or above 1-in-1 million or
to a chronic noncancer TOSHI greater than 1.
    The methodology and the results of the demographic analysis are
presented in a technical report, ``Risk and Technology Review--Analysis
of Socio-Economic Factors for Populations Living Near Friction
Materials Manufacturing Facilities,'' available in the docket for this
action.

B. What are our proposed decisions regarding risk acceptability, ample
margin of safety, and adverse environmental effects?

1. Risk Acceptability
    As noted in section II.A of this preamble, the EPA sets standards
under CAA section 112(f)(2) using ``a two-step standard-setting
approach, with an analytical first step to determine an `acceptable
risk' that considers all health information, including risk estimation
uncertainty, and includes a presumptive limit on MIR of approximately
1-in-10 thousand.'' (54 FR 38045, September 14, 1989).
    In this proposal, the EPA estimated risks based on actual and
allowable emissions from the FMM source category. As discussed above,
we consider our analysis of risk from allowable emissions to be
conservative in the sense of possibly over-estimating HAP emissions and
their associated risks.
    The inhalation cancer risk to the individual most exposed to
emissions from sources in the FMM source category is less than 1-in-1
million, based on actual emissions. The estimated incidence of cancer
due to inhalation exposure is 0.000005 excess cancer cases per year, or
1 case in 200,000 years, based on actual emissions. For allowable
emissions, we also estimate that the inhalation cancer risk to the
individual most exposed to emissions from sources in this source
category is less than 1-in-1 million. The estimated incidence of cancer
due to inhalation exposure is 0.00004 excess cancer cases per year, or
one case in every 25,000 years, based on allowable emissions.
    The Agency estimates that the maximum chronic noncancer TOSHI from
inhalation exposure is 0.01 due to actual emissions and 0.02 due to
allowable emissions. The screening assessment of worst-case acute
inhalation impacts from worst-case 1-hour emissions indicates that no
HAP exceed an acute HQ of 1.
    Since no PB-HAP are emitted by this source category, a multipathway
risk assessment was not warranted. We did not identify emissions of any
of the seven environmental HAP included in our environmental risk
screening assessment, and we are unaware of any adverse environmental
effects caused by HAP emitted by this source category. Therefore, we do
not expect an adverse environmental effect as a result of HAP emissions
from this source category.
    In determining whether risk is acceptable, the EPA considered all
available health information and risk estimation uncertainty, as
described above. The results indicate that both the actual and
allowable inhalation cancer risks to the individual most exposed are
less than 1-in-1 million, well below the presumptive limit of
acceptability of 100-in-1 million. The maximum chronic noncancer TOSHI
due to inhalation exposures is less than 1 for actual and allowable
emissions. Finally, the evaluation of acute noncancer risks was
conservative and showed that acute risks are below a level of concern.
    Taking into account this information, the EPA proposes that the
risk remaining after implementation of the existing MACT standards for
the FMM source category is acceptable.
2. Ample Margin of Safety Analysis
    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,
considering 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 and would be necessary to provide an
ample margin of safety to protect public health.
    Our risk analysis indicated the risks from the FMM source category
are low for both cancer and noncancer health effects, and, therefore,
any risk reductions from further available control options would result
in minimal health benefits. The options identified include a permanent
total enclosure and incinerator (PTEI), which is currently used at
Knowlton Technologies, LLC, (Knowlton uses a boiler to function as an
incinerator for HAP) and a non-solvent process/reformulation, which is
used at RFPC. A combination of the two technologies is not considered
to be a realistic control option because a PTEI would not add any
additional HAP control if a non-solvent process is used. Therefore, we
did not analyze such a combined technology option. We also note that
non-solvent process/reformulation is not yet demonstrated for all
products, and, therefore, cannot be broadly assumed to be feasible to
require. The estimated capital cost to install a PTEI at RFPC using a
solvent condenser is $1,612,105, and the estimated annual cost to
operate the system is $837,745. We estimate that the PTEI option would
achieve a HAP reduction of 228 tons, with a cost effectiveness of
$3,700 dollars per ton. The resultant risk reduction would be minimal
because the estimated risks are already below levels of concern. A
detailed cost breakdown can be found in the memorandum, ``Calculated
Cost of PTEI,'' which is located in the docket for this rulemaking.
    Cost estimates for installing and operating a non-solvent process/
reformulation are based on costs received from RFPC. The mixer and
downstream material processing equipment's estimated total capital
investment was $2,073,430. Annual cost of operation is approximately
$125,000 for electrical cost and $75,000 for maintenance. For more
information, see the memorandum, ``Email Correspondence for the Cost of
Non-Solvent Mixer RFPC,'' which is available in the docket for this
rulemaking. We do not have information that this technology could be
applied to other production lines with specific product formulations
and performance requirements, and, therefore, we determined that this
is not a broadly applicable control that is appropriate for
consideration under ample margin of safety. We do note, however, that
if the technology could be applied to other productions lines, the
resultant risk reduction would be minimal because the estimated risks
are already below levels of concern for the industry.
    Due to the low level of current risk, the minimal risk reductions
that could be achieved with the various control options that we
evaluated, and the substantial costs associated with each of the
additional control options, as well as the natural progression of
industry to move away from HAP containing solvents as acceptable non-
HAP formulations are developed, we are proposing that additional
emission controls are not necessary to provide an ample margin of
safety.
3. Adverse Environmental Effects
    We did not identify emissions of any of the seven environmental HAP
included in our environmental risk screening, and we are unaware of any
adverse environmental effects caused by HAP emitted by this source
category. Therefore, we do not expect adverse environmental effects as
a result of HAP emissions from this source category and we are
proposing that it is not necessary to set a more stringent standard to
prevent, taking into consideration costs, energy, safety, and other
relevant factors, an adverse environmental effect.

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

    In order to fulfill our obligations under CAA section 112(d)(6), we
conducted a technology review to identify developments in practices,
processes, and control technologies that reduce HAP emissions and to
consider whether the current standards should be revised to reflect any
such developments. In conducting our technology review, we utilized the
RBLC database, reviewed title V permits for each FMM facility, and
reviewed regulatory actions related to emissions controls at similar
sources that could be applicable to FMM.
    After reviewing information from the sources above, we identified
the following developments in control technologies for further
evaluation: PTEI, and non-solvent process/reformulation, i.e., the same
options we considered for possible ample margin of safety options,
discussed above. After identifying options for reducing emissions from
FMM, we then evaluated the feasibility, costs, and emissions reductions
associated with each of the technologies. Additional information about
this determination is documented in the memorandum, ``Technology Review
for the Friction Materials Manufacturing Source Category,'' which is
available in the docket for this action.
    We evaluated the cost of installing a PTEI at RFPC (currently
operating a solvent recovery system). The total capital investment for
installing a PTEI is described in the Ample Margin of Safety Analysis
(section IV.B.2) above. Overall, the estimated cost effectiveness of
installing and operating a PTEI is approximately $3,700 per ton of
hexane reduced. Furthermore, use of an incinerator would result in
increased energy usage and nitrogen oxide emissions. Considering the
associated cost per ton of hexane reduction and increased nitrogen
oxide emissions associated with the operation of an incinerator, we did
not find potentially requiring this technology to be cost effective or
necessary under CAA section 112(d)(6).
    RFPC is also in the process of removing HAP solvent from its
production process. It is accomplishing this through the utilization of
a non-solvent process/reformulation. This process change would
eventually eliminate the need for HAP solvents and their associated
emissions. The ability to use a non-solvent process/reformulation
depends primarily on each facility's ability to successfully
reformulate products while still meeting the required specifications.
Therefore, a change that may be used successfully to reduce HAP
emissions at one facility may not work for another facility or for all
products at the same facility. We do not consider this process change
to be a feasible regulatory alternative or necessary under CAA section
112(d)(6).
    Based on the results of the technology review, we conclude, and
propose to find, that changes to the FMM emissions limits pursuant to
CAA section 112(d)(6) are not necessary. We solicit comment on our
proposed decision.

D. What other actions are we proposing?

    In addition to the proposed determinations described above, we are
proposing some revisions to the rule. We are proposing revisions to the
SSM provisions of the MACT rule in order to ensure that they are
consistent with the Court's decision in Sierra Club v. EPA, 551 F. 3d
1019 (D.C. Cir. 2008), which vacated two provisions that exempted
sources from the requirement to comply with otherwise applicable CAA
section 112(d) emission standards during periods of SSM.
1. Startup, Shutdown, and Malfunction Requirements
    In its 2008 decision in Sierra Club v. EPA, 551 F.3d 1019 (D.C.
Cir. 2008), the Court vacated portions of two provisions in the EPA's
CAA section 112 regulations governing the emissions of HAP during
periods of SSM. Specifically, the Court vacated the SSM exemption
contained in 40 CFR 63.6(f)(1) and 40 CFR 63.6(h)(1), holding that
under section 302(k) of the CAA, emissions standards or limitations
must be continuous in nature and that the SSM exemption violates the
CAA's requirement that some CAA section 112 standards apply
continuously.
    We are proposing the elimination of the SSM exemption in this rule.
Consistent with Sierra Club v. EPA, we are proposing standards in this
rule that apply at all times. We are also proposing several revisions
to Table 1 to 40 CFR part 63, subpart QQQQQ (the General Provisions
Applicability Table), as explained in more detail below. 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 and revise certain recordkeeping and
reporting requirements related to the SSM exemption as further
described below.
    The EPA has attempted to ensure that the provisions we are
proposing to eliminate are inappropriate, unnecessary, or redundant in
the absence of the SSM exemption. We are specifically seeking comment
on whether we have successfully done so.
    In proposing to make the current standards in the rule applicable
during SSM periods, the EPA has taken into account startup and shutdown
periods and, for the reasons explained below, has not proposed
alternate standards for those periods. The two FMM facilities subject
to this rulemaking run their associated control technologies during all
periods of operation, including startup and shutdown, allowing them to
comply with the emissions standards at all times. The EPA has no reason
to believe that emissions are significantly different during periods of
startup and shutdown from those during normal operations.
    Periods of startup, normal operations, and shutdown are all
predictable and routine aspects of a source's operations. Malfunctions,
in contrast, are neither predictable nor routine. Instead they are, by
definition, sudden, infrequent, and not reasonably preventable failures
of emissions control, processes, or monitoring equipment. (40 CFR 63.2)
(definition of malfunction). The EPA interprets CAA section 112 as not
requiring emissions that occur during periods of malfunction to be
factored into development of CAA section 112 standards and this reading
has been upheld as reasonable by the Court in U.S. Sugar Corp. v. EPA,
830 F.3d 579, 606-610 (2016). Under CAA 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 CAA section 112 that directs the
Agency to consider malfunctions in determining the level ``achieved''
by the best performing sources when setting emission standards. As the
Court has recognized, the phrase ``average emissions limitation
achieved by the best performing 12 percent of'' sources ``says nothing
about how the performance of the best units is to be calculated.''
Nat'l Ass'n of Clean Water Agencies v. EPA, 734 F.3d 1115, 1141 (D.C.
Cir. 2013). While the EPA accounts for variability in setting emissions
standards, nothing in CAA section 112 requires the Agency to consider
malfunctions as part of that analysis. The EPA is not required to treat
a malfunction in the same manner as the type of variation in
performance that occurs during routine operation of a source. A
malfunction is a failure of

the source to perform in a ``normal or usual manner'' and no statutory
language compels the EPA to consider such events in setting CAA section
112 standards.
    As the Court recognized in U.S. Sugar Corp, accounting for
malfunctions in setting numerical or work practice standards would be
difficult, if not impossible, given the myriad different types of
malfunctions that can occur across all sources in a category and given
the difficulties associated with predicting or accounting for the
frequency, degree, and duration of various malfunctions that might
occur. Id. at 608 (``the EPA would have to conceive of a standard that
could apply equally to the wide range of possible boiler malfunctions,
ranging from an explosion to minor mechanical defects. Any possible
standard is likely to be hopelessly generic to govern such a wide array
of circumstances.''). 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, emissions during a malfunction event can be significantly
higher than emissions at any other time of source operation. For
example, if an air pollution control device with 99-percent removal
goes off-line as a result of a malfunction (as might happen if, for
example, the bags in a baghouse catch fire) and the emission unit is a
steady state type unit that would take days to shut down, the source
would go from 99-percent control to zero control until the control
device was repaired. The source's emissions during the malfunction
would be 100 times higher than during normal operations. As such, the
emissions over a 4-day malfunction period would exceed the annual
emissions of the source during normal operations. As this example
illustrates, accounting for malfunctions could lead to standards that
are not reflective of (and significantly less stringent than) levels
that are achieved by a well-performing non-malfunctioning source. It is
reasonable to interpret CAA section 112 to avoid such a result. The
EPA's approach to malfunctions is consistent with CAA section 112 and
is a reasonable interpretation of the statute.
    Although no statutory language compels the EPA to set standards for
malfunctions, the EPA has the discretion to do so where feasible. For
example, in the Petroleum Refinery Sector Risk and Technology Review,
the EPA established a work practice standard for unique types of
malfunction that result in releases from pressure relief devices or
emergency flaring events because the EPA had information to determine
that such work practices reflected the level of control that applies to
the best performing sources. 80 FR 75178, 75211-14 (December 1, 2015).
The EPA will consider whether circumstances warrant setting work
practice standards for a particular type of malfunction and, if so,
whether the EPA has sufficient information to identify the relevant
best performing sources and establish a standard for such malfunctions.
We also encourage commenters to provide any such information.
    In the event that a source fails to comply with the applicable CAA
section 112 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 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).
    If the EPA determines in a particular case that an enforcement
action against a source for violation of an emission standard is
warranted, the source can raise any and all defenses in that
enforcement action and the federal district court will determine what,
if any, relief is appropriate. The same is true for citizen enforcement
actions. Similarly, the presiding officer in an administrative
proceeding can consider any defense raised and determine whether
administrative penalties are appropriate.
    In summary, the EPA interpretation of the CAA and, in particular,
CAA section 112 is reasonable and encourages practices that will avoid
malfunctions. Administrative and judicial procedures for addressing
exceedances of the standards fully recognize that violations may occur
despite good faith efforts to comply and can accommodate those
situations. U.S. Sugar Corp. v. EPA, 830 F.3d 579, 606-610 (2016).
2. 40 CFR 63.9505 General Compliance Requirements
    We are proposing to revise the General Provisions table (Table 1 to
40 CFR part 63, subpart QQQQQ) entry for 40 CFR 63.6(e)(1)(i) by
changing the ``yes'' in column ``Applies to subpart QQQQQ?'' to a
``no.'' Section 63.6(e)(1)(i) describes the general duty to minimize
emissions. Some of the language in that section is no longer necessary
or appropriate in light of the elimination of the SSM exemption. We are
proposing instead to add general duty regulatory text at 40 CFR 63.9505
that reflects the general duty to minimize emissions while eliminating
the reference to periods covered by an SSM exemption. The current
language in 40 CFR 63.6(e)(1)(i) characterizes what the general duty
entails during periods of SSM. With the elimination of the SSM
exemption, there is no need to differentiate between normal operations,
startup and shutdown, and malfunction events in describing the general
duty. Therefore, the language the EPA is proposing at 40 CFR 63.9505(a)
and (c) does not include that language from 40 CFR 63.6(e)(1).
    We are also proposing to revise the General Provisions table (Table
1 to 40 CFR part 63, subpart QQQQQ) entry for 40 CFR 63.6(e)(1)(ii) by
changing the ``yes'' in column ``Applies to subpart QQQQQ?'' to a
``no.'' Section 63.6(e)(1)(ii) imposes requirements that are not
necessary with the elimination of the SSM exemption or are redundant
with the general duty requirement being added at 40 CFR 63.9505.
3. SSM Plan
    We are proposing to revise the General Provisions table (Table 1 to
40 CFR part 63, subpart QQQQQ) entry for 40 CFR 63.6(e)(3) by changing
the ``yes'' in column ``Applies to subpart QQQQQ?'' to a ``no.''
Generally, these paragraphs require development of an SSM plan and
specify SSM recordkeeping and reporting requirements related to the SSM
plan. As noted, the EPA is proposing to remove the SSM exemptions.
Therefore,

affected units will be subject to an emission standard during such
events. The applicability of a standard during such events will ensure
that sources have ample incentive to plan for and achieve compliance,
and, thus, the SSM plan requirements are no longer necessary.
4. Compliance With Standards
    We are proposing to revise the General Provisions table (Table 1 to
40 CFR part 63, subpart QQQQQ) entry for 40 CFR 63.6(f)(1) by changing
the ``yes'' in column ``Applies to subpart QQQQQ?'' to a ``no.'' The
current language of 40 CFR 63.6(f)(1) exempts sources from non-opacity
standards during periods of SSM. As discussed above, the Court in
Sierra Club vacated the exemptions contained in this provision and held
that the CAA requires that some CAA section 112 standards apply
continuously. Consistent with Sierra Club, the EPA is proposing to
revise standards in this rule to apply at all times.
5. Monitoring
    We are proposing to revise the General Provisions table (Table 1 to
40 CFR part 63, subpart QQQQQ) entry for 40 CFR 63.8(c)(1)(i) and (iii)
by changing the ``yes'' in column ``Applies to subpart QQQQQ?'' to a
``no.'' The cross-references to the general duty and SSM plan
requirements in those paragraphs are not necessary in light of other
requirements of 40 CFR 63.8 that require good air pollution control
practices (40 CFR 63.8(c)(1)).
6. 40 CFR 63.9545 What records must I keep?
    We are proposing to revise the General Provisions table (Table 1 to
40 CFR part 63, subpart QQQQQ) entry for 40 CFR 63.10(b)(2)(i) by
changing the ``yes'' in column ``Applies to subpart QQQQQ?'' to a
``no.'' Section 63.10(b)(2)(i) describes the recordkeeping requirements
during startup and shutdown. These recording provisions are no longer
necessary because the EPA is proposing that recordkeeping and reporting
applicable to normal operations will apply to startup and shutdown. In
the absence of special provisions applicable to startup and shutdown,
such as a startup and shutdown plan, there is no reason to retain
additional recordkeeping for startup and shutdown periods.
    We are proposing to revise the General Provisions table (Table 1 to
40 CFR part 63, subpart QQQQQ) entry for 40 CFR 63.10(b)(2)(ii) by
changing the ``yes'' in column ``Applies to subpart QQQQQ?'' to a
``no.'' Section 63.10(b)(2)(ii) describes the recordkeeping
requirements during a malfunction. The EPA is proposing to add such
requirements to 40 CFR 63.9545. The regulatory text we are proposing to
add differs from the General Provisions it is replacing in that the
General Provisions requires the creation and retention of a record of
the occurrence and duration of each malfunction of process, air
pollution control, and monitoring equipment. The EPA is proposing that
this requirement apply to any failure to meet an applicable standard
and is requiring that the source record the date, time, and duration of
the failure rather than the ``occurrence.'' The EPA is also proposing
to add to 40 CFR 63.9545 a requirement that sources keep records that
include a list of the affected source or equipment and actions taken to
minimize emissions, an estimate of the quantity of each regulated
pollutant emitted over the standard for which the source failed to meet
the standard, and a description of the method used to estimate the
emissions. Examples of such methods would include product-loss
calculations, mass balance calculations, measurements when available,
or engineering judgment based on known process parameters. The EPA is
proposing to require that sources keep records of this information to
ensure that there is adequate information to allow the EPA to determine
the severity of any failure to meet a standard, and to provide data
that may document how the source met the general duty to minimize
emissions when the source has failed to meet an applicable standard.
    We are proposing to revise the General Provisions table (Table 1 to
40 CFR part 63, subpart QQQQQ) entry for 40 CFR 63.10(b)(2)(iv) by
changing the ``yes'' in column ``Applies to subpart QQQQQ?'' to a
``no.'' When applicable, the provision requires sources to record
actions taken during SSM events when actions were inconsistent with
their SSM plan. The requirement is no longer appropriate because SSM
plans will no longer be required. The requirement previously applicable
under 40 CFR 63.10(b)(2)(iv)(B) to record actions to minimize emissions
and record corrective actions is now applicable by reference to 40 CFR
63.9545(a)(2).
    We are proposing to revise the General Provisions table (Table 1 to
40 CFR part 63, subpart QQQQQ) entry for 40 CFR 63.10(b)(2)(v) by
changing the ``yes'' in column ``Applies to subpart QQQQQ?'' to a
``no.'' When applicable, the provision requires sources to record
actions taken during SSM events to show that actions taken were
consistent with their SSM plan. The requirement is no longer
appropriate because SSM plans will no longer be required.
7. 40 CFR 63.9540 What reports must I submit and when?
    We are proposing to revise the General Provisions table (Table 1 to
40 CFR part 63, subpart QQQQQ) entry for 40 CFR 63.10(d)(5) by changing
the ``yes'' in column ``Applies to subpart QQQQQ?'' to a ``no.''
Section 63.10(d)(5) describes the reporting requirements for startups,
shutdowns, and malfunctions. To replace the General Provisions
reporting requirement, the EPA is proposing to add reporting
requirements to 40 CFR 63.9540(b)(4). The replacement language differs
from the General Provisions requirement in that it eliminates periodic
SSM reports as a stand-alone report. We are proposing language that
requires sources that fail to meet an applicable standard at any time
to report the information concerning such events in the semi-annual
compliance report already required under this rule. We are proposing
that the report must contain the number, date, time, duration, and the
cause of such events (including unknown cause, if applicable), a list
of the affected source(s) or equipment, an estimate of the quantity of
each regulated pollutant emitted over any emission limit, and a
description of the method used to estimate the emissions.
    Examples of such methods would include product-loss calculations,
mass balance calculations, measurements when available, or engineering
judgment based on known process parameters. The EPA is proposing this
requirement to ensure that there is adequate information to determine
compliance, to allow the EPA to determine the severity of the failure
to meet an applicable standard, and to provide data that may document
how the source met the general duty to minimize emissions during a
failure to meet an applicable standard.
    We will no longer require owners or operators to determine whether
actions taken to correct a malfunction are consistent with an SSM plan,
because such plans will no longer be required. The proposed amendments,
therefore, eliminate the cross reference to 40 CFR 63.10(d)(5)(i) that
contains the description of the previously required SSM report format
and submittal schedule from this section. These specifications are no
longer necessary because the events will be reported in otherwise
required reports with similar format and submittal requirements.
    We are proposing to revise the General Provisions table (Table 1 to
40

CFR part 63, subpart QQQQQ) entry for 40 CFR 63.10(d)(5)(ii) by
changing the ``yes'' in column ``Applies to subpart QQQQQ?'' to a
``no.'' Section 63.10(d)(5)(ii) describes an immediate report for
startup, shutdown, and malfunctions when a source fails to meet an
applicable standard, but does not follow the SSM plan. We will no
longer require owners and operators to report when actions taken during
a startup, shutdown, or malfunction were not consistent with an SSM
plan, because such plans will no longer be required.

E. What compliance dates are we proposing?

    The EPA is proposing that existing affected sources and affected
sources that commenced construction or reconstruction on or before May
3, 2018 must comply with all of the amendments no later than 180 days
after the effective date of the final rule. (The final action is not
expected to be a ``major rule'' as defined by 5 U.S.C. 804(2), so the
effective date of the final rule will be the promulgation date as
specified in CAA section 112(d)(10)). For existing sources, we are
proposing a change that would impact ongoing compliance requirements
for 40 CFR part 63, subpart QQQQQ. As discussed elsewhere in this
preamble, we are proposing to change the requirements for SSM by
removing the exemption from the requirements to meet the standard
during SSM periods and by removing the requirement to develop and
implement an SSM plan. Our experience with similar industries shows
that this sort of regulated facility generally requires a time period
of 180 days to read and understand the amended rule requirements; to
evaluate their operations to ensure that they can meet the standards
during periods of startup and shutdown as defined in the rule and make
any necessary adjustments; and to update their operations to reflect
the revised requirements. From our assessment of the timeframe needed
for compliance with the revised requirements, the EPA considers a
period of 180 days to be the most expeditious compliance period
practicable, and, thus, is proposing that existing affected sources be
in compliance with this regulation's revised requirements within 180
days of the regulation's effective date. We solicit comment on this
proposed compliance period, and we specifically request submission of
information from sources in this source category regarding specific
actions that would need to be undertaken to comply with the proposed
amended requirements and the time needed to make the adjustments for
compliance with them. We note that information provided may result in
changes to the proposed compliance date. Affected sources that commence
construction or reconstruction after May 3, 2018 must comply with all
requirements of the subpart, including the amendments being proposed,
no later than the effective date of the final rule or upon startup,
whichever is later. All affected facilities would have to continue to
meet the current requirements of subpart QQQQQ until the applicable
compliance date of the amended rule.

V. Summary of Cost, Environmental, and Economic Impacts

A. What are the affected sources?

    We anticipate that two FMM facilities currently operating in the
United States will be affected by these proposed amendments. The basis
of our estimate of affected facilities are provided in the memorandum,
``Identification of Major Sources for the NESHAP for Friction Materials
Manufacturing,'' which is available in the docket for this action. We
are not currently aware of any planned or potential new or
reconstructed FMM facilities.

B. What are the air quality impacts?

    We do not anticipate that the proposed amendments to this subpart
will impact air quality.

C. What are the cost impacts?

    The two existing FMM facilities that would be subject to the
proposed amendments would incur a net cost savings due to revised
recordkeeping and reporting requirements. Nationwide annual net cost
savings associated with the proposed requirements are estimated to be
$7,358 in 2016 dollars. For further information on the costs and cost
savings associated with the requirements being proposed, see the
memorandum, ``FMM Economic Impacts Memo,'' and the document, ``Friction
Materials Manufacturing 2018 Supporting Statement,'' which are both
available in the docket for this action. We solicit comment on these
estimated cost impacts.

D. What are the economic impacts?

    As noted earlier, the nationwide annual net cost savings associated
with the revised recordkeeping and reporting requirements are estimated
to be $7,358 per year. The equivalent annualized value (in 2016
dollars) of these net cost savings over 2019 through 2027 is $6,461 per
year when costs are discounted at a 7-percent rate, and $7,381 per year
when costs are discounted at a 3-percent rate. This cost savings is not
expected to result in changes to business operations, or result in a
significant price change of products.

E. What are the benefits?

    As discussed above, we do not anticipate the proposed amendments to
this subpart to impact air quality.

VI. Request for Comments

    We solicit comments on all aspects of this proposed action. In
addition to general comments on this proposed action, we are also
interested in additional data that may improve the risk assessments and
other analyses. We are specifically interested in receiving any
information that improves the quality and quantity of data used in 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 and instructions are available for
download on the RTR website at http://www3.epa.gov/ttn/atw/rrisk/rtrpg.html. The data files include detailed information for each HAP
emissions release point for the facilities 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 available ``improved'' data. When you
submit data, we request that you provide documentation of the basis for
any revised values. To submit comments on the data downloaded from the
RTR website, complete the following steps:
    1. Within this downloaded file, enter suggested revisions to the
data fields appropriate for that information.
    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[supreg] Access format and all accompanying documentation to
Docket ID No. EPA-HQ-OAR-2017-0358 (through the

method described in the ADDRESSES section of this preamble).
    5. Whether you are providing comments on a single facility or
multiple facilities, you need only submit one file. The file should
contain all suggested changes for all sources at that facility (or
facilities). We request that all data revision comments be submitted in
the form of updated Microsoft[supreg] Excel files that are generated by
the Microsoft[supreg] Access file. These files are provided on the RTR
website at http://www3.epa.gov/ttn/atw/rrisk/rtrpg.html.

VIII. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive Orders
can be found at http://www2.epa.gov/laws-regulations/laws-and-executive-orders.

A. Executive Order 12866: Regulatory Planning and Review and Executive