Document ID: EPA-HQ-OAR-2020-0148-0001
Agency: epa
Document Type: Proposed Rule
Title: National Emission Standards for Hazardous Air Pollutants: Refractory Products Manufacturing Residual Risk and Technology Review
Posted Date: 2021-01-14T05:00Z

[Federal Register Volume 86, Number 9 (Thursday, January 14, 2021)]
[Proposed Rules]
[Pages 3079-3108]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-00137]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2020-0148; FRL-10018-66-OAR]
RIN 2060-AU67

National Emission Standards for Hazardous Air Pollutants: 
Refractory Products Manufacturing Residual Risk and Technology Review

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The U.S. Environmental Protection Agency (EPA) is proposing 
amendments to address the results of the residual risk and technology 
review (RTR) that the EPA is required to conduct in accordance with the 
Clean Air Act (CAA) with regard to the National Emissions Standards for 
Hazardous Air Pollutants (NESHAP) for Refractory Products 
Manufacturing. The EPA is proposing to find the risks due to emissions 
of air toxics from this source category under the current standards to 
be acceptable and that the standards provide an ample margin of safety 
to protect public health. We are proposing no revisions to the existing 
numerical emission limits based on these analyses; however, we are 
proposing new provisions for certain hazardous air pollutants (HAP). 
The EPA is also proposing to amend provisions addressing emissions 
during periods of startup, shutdown, and malfunction (SSM) and 
provisions addressing emissions during periods of scheduled 
maintenance; to amend provisions regarding electronic reporting of 
performance test results; and to make miscellaneous clarifying and 
technical corrections.

DATES: Comments.
    Comments must be received on or before March 1, 2021. 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 February 16, 2021.
    Public hearing. If anyone contacts us requesting a public hearing 
on or before January 19, 2021, we will hold a virtual public hearing. 
See SUPPLEMENTARY INFORMATION for information on requesting and 
registering for a public hearing.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OAR-2020-0148, by any of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov/ 
(our preferred method). Follow the online instructions for submitting 
comments.
     Email: a-and-r-docket@epa.gov. Include Docket ID No. EPA-
HQ-OAR-2020-0148 in the subject line of the message.
     Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-
2020-0148.
     Mail: U.S. Environmental Protection Agency, EPA Docket 
Center, Docket ID No. EPA-HQ-OAR-2020-0148, Mail Code 28221T, 1200 
Pennsylvania Avenue NW, Washington, DC 20460.
     Hand/Courier Delivery (by scheduled appointment only): EPA 
Docket Center, WJC West Building, Room 3334, 1301 Constitution Avenue 
NW, Washington, DC 20004. The Docket Center's hours of operation are 
8:30 a.m.-4:30 p.m., Monday-Friday (except federal holidays).
    Instructions: All submissions received must include the Docket ID 
No. for this rulemaking. Comments received may be posted without change 
to https://www.regulations.gov/, including any personal information 
provided. For detailed instructions on sending comments and additional 
information on the rulemaking process, see the SUPPLEMENTARY 
INFORMATION section of this document. Out of an abundance of caution 
for members of the public and

[[Page 3080]]

our staff, the EPA Docket Center and Reading Room are closed to the 
public, with limited exceptions, to reduce the risk of transmitting 
COVID-19. Our Docket Center staff will continue to provide remote 
customer service via email, phone, and webform. We encourage the public 
to submit comments via https://www.regulations.gov/ or email, as there 
may be a delay in processing mail and faxes. Hand deliveries and 
couriers may be received by scheduled appointment only. For further 
information on EPA Docket Center services and the current status, 
please visit us online at https://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: For questions about this proposed 
action, contact Ms. Paula Hirtz, Minerals and Manufacturing Group, 
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: (919) 541-2618; 
fax number: (919) 541-4991; and email address: hirtz.paula@epa.gov. For 
specific information regarding the risk modeling methodology, contact 
Mr. Chris Sarsony, Health and Environmental Impacts Division (C539-02), 
Office of Air Quality Planning and Standards, U.S. Environmental 
Protection Agency, Research Triangle Park, North Carolina 27711; 
telephone number: (919) 541-4843; fax number: (919) 541-0840; and email 
address: sarsony.chris@epa.gov.

SUPPLEMENTARY INFORMATION:
    Participation in virtual public hearing. Please note that the EPA 
is deviating from its typical approach for public hearings because the 
President has declared a national emergency. Due to the current Centers 
for Disease Control and Prevention (CDC) recommendations, as well as 
state and local orders for social distancing to limit the spread of 
COVID-19, the EPA cannot hold in-person public meetings at this time.
    To request a virtual public hearing, contact the public hearing 
team at (888) 372-8699 or by email at SPPDpublichearing@epa.gov. If 
requested, the virtual hearing will be held on January 29, 2021. The 
hearing will convene at 9:00 a.m. Eastern Time and will conclude at 
3:00 p.m. ET. The EPA may close a session 15 minutes after the last 
pre-registered speaker has testified if there are no additional 
speakers. The EPA will announce further details at https://www.epa.gov/stationary-sources-air-pollution/refractory-products-manufacturing-national-emissions-standards.
    Upon publication of this document in the Federal Register, the EPA 
will begin pre-registering speakers for the hearing, if a public 
hearing is requested. To register to speak at the virtual hearing, 
please use the online registration form available at https://www.epa.gov/stationary-sources-air-pollution/refractory-products-manufacturing-national-emissions-standards or contact the public 
hearing team at (888) 372-8699 or by email at 
SPPDpublichearing@epa.gov. The last day to pre-register to speak at the 
hearing will be January 26, 2021. Prior to the hearing, the EPA will 
post a general agenda that will list pre-registered speakers in 
approximate order at: https://www.epa.gov/stationary-sources-air-pollution/refractory-products-manufacturing-national-emissions-standards.
    The EPA will make every effort to follow the schedule as closely as 
possible on the day of the hearing; however, please plan for the 
hearings to run either ahead of schedule or behind schedule.
    Each commenter will have 5 minutes to provide oral testimony. The 
EPA encourages commenters to provide the EPA with a copy of their oral 
testimony electronically (via email) by emailing it to 
hirtz.paula@epa.gov. The EPA also recommends submitting the text of 
your oral testimony as written comments to the rulemaking docket.
    The EPA may ask clarifying questions during the oral presentations 
but will not respond to the presentations at that time. Written 
statements and supporting information submitted during the comment 
period will be considered with the same weight as oral testimony and 
supporting information presented at the public hearing.
    Please note that any updates made to any aspect of the hearing will 
be posted online at https://www.epa.gov/stationary-sources-air-pollution/refractory-products-manufacturing-national-emissions-standards. While the EPA expects the hearing to go forward as set forth 
above, please monitor our website or contact the public hearing team at 
(888) 372-8699 or by email at SPPDpublichearing@epa.gov to determine if 
there are any updates. The EPA does not intend to publish a document in 
the Federal Register announcing updates.
    If you require the services of a translator or a special 
accommodation such as audio description, please pre-register for the 
hearing with the public hearing team and describe your needs by January 
21, 2021. The EPA may not be able to arrange accommodations without 
advanced notice.
    Docket. The EPA has established a docket for this rulemaking. 
Docket ID No. EPA-HQ-OAR-2020-0148 has been established for 40 CFR part 
63, subpart SSSSS, Refractory Products Manufacturing. All documents in 
the docket are listed in https://www.regulations.gov/. Although listed, 
some information is not publicly available, e.g., Confidential Business 
Information (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. With the exception of such material, publicly available docket 
materials are available electronically in Regulations.gov.
    Instructions. Direct your comments to Docket ID No. EPA-HQ-OAR-
2020-0148. 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 https://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 electronically any information that you consider 
to be CBI or other information whose disclosure is restricted by 
statue. This type of information should be submitted by mail as 
discussed below.
    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://www.epa.gov/dockets/commenting-epa-dockets.
    The https://www.regulations.gov/ website allows you to submit your 
comment anonymously, 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 
https://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

[[Page 3081]]

recommends that you include your name and other contact information in 
the body of your comment and with any digital storage media 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 https://www.epa.gov/dockets.
    The EPA is temporarily suspending its Docket Center and Reading 
Room for public visitors, with limited exceptions, to reduce the risk 
of transmitting COVID-19. Our Docket Center staff will continue to 
provide remote customer service via email, phone, and webform. We 
encourage the public to submit comments via https://www.regulations.gov/ as there may be a delay in processing mail and 
faxes. Hand deliveries or couriers will be received by scheduled 
appointment only. For further information and updates on EPA Docket 
Center services, please visit us online at https://www.epa.gov/dockets.
    The EPA continues to carefully and continuously monitor information 
from the CDC, local area health departments, and our Federal partners 
so that we can respond rapidly as conditions change regarding COVID-19.
    Submitting CBI. Do not submit information containing CBI to the EPA 
through https://www.regulations.gov/ or email. Clearly mark the part or 
all of the information that you claim to be CBI. For CBI information on 
any digital storage media that you mail to the EPA, mark the outside of 
the digital storage media as CBI and then identify electronically 
within the digital storage media 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 directly 
to the public docket through the procedures outlined in Instructions 
above. If you submit any digital storage media that does not contain 
CBI, mark the outside of the digital storage media 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-2020-0148. Note that 
written comments containing CBI and submitted by mail may be delayed 
and no hand deliveries will be accepted.
    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
ASTM American Society for Testing and Materials
CAA Clean Air Act
CalEPA California EPA
CBI Confidential Business Information
CDX Central Data Exchange
CEDRI Compliance and Emissions Data Reporting Interface
CFR Code of Federal Regulations
ECHO Enforcement and Compliance History Online
EPA Environmental Protection Agency
ERPG emergency response planning guideline
ERT Electronic Reporting Tool
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
HQREL hazard quotient recommended exposure limit
IBR incorporation by reference
IRIS Integrated Risk Information System
kg kilogram
km kilometer
MACT maximum achievable control technology
mg/m3 milligrams per cubic meter
MIR maximum individual risk
NAAQS National Ambient Air Quality Standards
NEI National Emission Inventory
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
PDF portable document format
POM polycyclic organic matter
PRA Paperwork Reduction Act
RBLC Reasonably Available Control Technology/Best Available Control 
Technology/Lowest Achievable Emission Rate Clearinghouse
REL reference exposure level
RfC reference concentration
RTO regenerative thermal oxidizer
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
TRIM.FaTE Total Risk Integrated Methodology.Fate, Transport, and 
Ecological Exposure model
UF uncertainty factor
[micro]g/m3 micrograms per cubic meter
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?
II. Background
    A. What is the statutory authority for this action?
    B. What is the 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 and Decision-Making
    A. How do we consider risk in our decision-making?
    B. How do we perform the technology review?
    C. How do we estimate post-MACT risk posed by the source 
category?
IV. Analytical Results and Proposed Decisions
    A. What actions are we taking pursuant to CAA sections 112(d)(2) 
and (d)(3)?
    B. What are the results of the risk assessment and analyses?
    C. What are our proposed decisions regarding risk acceptability, 
ample margin of safety, and adverse environmental effect?
    D. What are the results and proposed decisions based on our 
technology review?
    E. What other actions are we proposing?
    F. 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 Regulations and Controlling 
Regulatory Costs
    C. Paperwork Reduction Act (PRA)
    D. Regulatory Flexibility Act (RFA)
    E. Unfunded Mandates Reform Act (UMRA)

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    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) and 
1 CFR part 51
    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?

    Refractory Products Manufacturing, the source category that is the 
subject of this proposal, is regulated under 40 CFR part 63, subpart 
SSSSS. The North American Industry Classification System (NAICS) codes 
for the refractory products industry are 327124 (clay) and 327125 
(nonclay). We estimate that three major source facilities engaged in 
refractory products manufacturing would be affected by this proposal. 
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. The Refractory 
Products Manufacturing source category was revised since 1992 when it 
originally appeared 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) and Documentation for Developing the Initial 
Source Category List, Final Report (see EPA-450/3-91-030, July 1992). 
At that time the source category was listed as Chromium Refractories 
Production and it was defined to include any facility engaged in 
producing chromium-containing refractories. Refractories were defined 
as heat-resistant materials used to build or line high-temperature 
industrial furnaces, and chromium-containing refractories were defined 
as refractories produced from chrome ore or chromic oxide along with 
other raw materials such as alumina, zirconia, silica, and magnesia. 
The category included, but was not limited to, facilities that 
manufacture magnesia-chrome, chrome-magnesite, chrome alumina, and 
chromic oxide refractories. Also included were facilities that 
manufactured either formed (bricks) or unformed (mortar, castables) 
chromium-containing refractories.
    The source category was renamed in 1999 to Refractories 
Manufacturing in the National Emission Standards for Hazardous Air 
Pollutants (NESHAP): Revision of Source Category List and Schedule for 
Standards Under Section 112 of the Clean Air Act (see 64 FR 3025, 
November 18, 1999). By that time the EPA had obtained information from 
nonchromium refractory manufacturing plants that confirmed they were 
major sources of HAP emissions. Because the production of nonchromium 
refractories at those facilities would not be covered by other source 
categories on the source category list, the EPA decided to expand the 
scope of the source category to include the nonchromium refractory 
manufacturing sources.
    The source category was subsequently renamed in 2002 to Refractory 
Products Manufacturing in the National Emission Standards for Hazardous 
Air Pollutants (NESHAP) for Refractory Products Manufacturing, proposed 
rule preamble (67 FR 42108, June 20, 2002). In this proposed action, 
the EPA revised and further clarified the source category as provided 
by section 112(c) of the CAA. The source category is defined to 
include, but is not limited to, any facility that manufactures 
refractory bricks and shapes that are produced using an organic HAP 
compound, pitch-impregnated refractory products, chromium refractory 
products, and fired clay refractory products.

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 
https://www.epa.gov/stationary-sources-air-pollution/refractory-products-manufacturing-national-emissions-standards. Following 
publication in the Federal Register, the EPA will post the Federal 
Register version of the proposal and key technical documents at these 
same websites. Information on the overall RTR program is available at 
https://www.epa.gov/stationary-sources-air-pollution/risk-and-technology-review-national-emissions-standards-hazardous.
    The proposed changes to the CFR that would be necessary to 
incorporate the changes proposed in this action are set out in an 
attachment to the memorandum titled Proposed Regulation Edits for 40 
CFR part 63, subpart SSSSS, available in the docket for this action 
(Docket ID No. EPA-HQ-OAR-2020-0148). The document includes the 
specific proposed amendatory language for revising the CFR and, for the 
convenience of interested parties, a redline version of the regulation. 
Following signature by the EPA Administrator, the EPA will also post a 
copy of this memorandum and the attachments to https://www.epa.gov/stationary-sources-air-pollution/refractory-products-manufacturing-national-emissions-standards.

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.).\1\ 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 those standards that are based on 
maximum achievable control technology (MACT) to determine whether 
additional standards are needed to 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 and revise the standards as necessary taking 
into account any ``developments in practices, processes, or control 
technologies.'' 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 titled CAA Section 112 Risk and Technology Reviews: 
Statutory Authority and Methodology, in the docket for this rulemaking 
(Docket ID No. EPA-HQ-OAR-2020-0148).
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    \1\ In addition, section 301 of the CAA provides general 
authority for the Administrator to ``prescribe such regulations as 
are necessary to carry out his functions'' under the CAA.
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    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

[[Page 3083]]

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)(2) 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.'' In certain instances, as provided in CAA section 
112(h), the EPA may set work practice standards in lieu of numerical 
emission standards. 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. 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 pursuant to CAA 
section 112(f). For source categories subject to MACT standards, 
section 112(f)(2) of the CAA requires the EPA to determine 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 approach 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 Residual 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 (DC 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) 
\2\ of approximately 1-in-10 thousand.'' (54 FR at 38045). If risks are 
unacceptable, the EPA must determine the emissions standards necessary 
to reduce risk 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 to protect public health 
``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 
or determine that the standards being reviewed provide an ample margin 
of safety without any revisions. 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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    \2\ 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.
---------------------------------------------------------------------------

    The 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 often than every 8 years. In 
conducting this review, which we call the ``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 section 112(d)(6). The EPA is required to 
address regulatory gaps, such as missing standards for listed air 
toxics known to be emitted from the source category. Louisiana 
Environmental Action Network (LEAN) v. EPA, 955 F.3d 1088 (DC Cir. 
2020).

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

1. Source Category Description
    The NESHAP for the Refractory Products Manufacturing source 
category was promulgated on April 16, 2003 (68 FR 18730), and is 
codified at 40 CFR part 63, subpart SSSSS. Minor amendments were made 
to the NESHAP related to the SSM provisions on April 20, 2006 (71 FR 
20471). The Refractory Products Manufacturing NESHAP applies to each 
new, reconstructed, and existing affected source located at a 
refractory products manufacturing facility that is a major source of 
HAP emissions, is located at a major source of HAP emissions, or is 
part of a major source of HAP emissions. The affected sources include 
the following: shape dryers, curing ovens, and kilns that are used to 
manufacture refractory products that use organic HAP; shape preheaters, 
pitch working tanks, defumers, and coking ovens that are used to 
produce pitch-impregnated refractory products; kilns that are used to 
manufacture chromium refractory products; and kilns that are used to 
manufacture clay refractory products. A refractory products 
manufacturing facility is a plant site that manufactures refractory 
products, such as refractory bricks, refractory shapes, monolithics, 
kiln furniture, crucibles, and other materials used for lining furnaces 
and other high temperature process units. Refractory products 
manufacturing facilities typically process raw material by crushing, 
grinding, and screening; mixing the processed raw materials with 
binders and other additives; forming the refractory mix into shapes; 
and drying and firing the shapes.
    Based on our search of the 2017 National Emission Inventory (NEI) 
(www.epa.gov/air-emissions-inventories/national-emissions-inventory-nei) and the EPA's Enforcement and Compliance History Online (ECHO) 
database (echo.epa.gov) and a review of active air emissions permits, 
we estimate that three major source facilities are subject to the 
Refractory Products Manufacturing

[[Page 3084]]

NESHAP. The three facilities that are subject to the Refractory 
Products Manufacturing NESHAP are listed in Appendix 1 to the 
memorandum titled Technology Review for the Refractory Products 
Manufacturing Source Category, in the Refractory Products Manufacturing 
Docket (Docket ID No. EPA-HQ-OAR-2020-0148).
2. HAP Emission Sources
    The EPA estimated that a total of 167 refractory products 
manufacturing plants were operating in the U.S. in 2002. As a result of 
a comprehensive information collection request (ICR) that was sent out 
to the refractory products manufacturing industry at that time, the EPA 
found only eight of the 167 plants to be major sources of HAP and 
subject to the Refractory Products Manufacturing NESHAP (67 FR 42130, 
June 20, 2002). At that time, the EPA identified the primary sources of 
HAP emissions at most refractory products manufacturing plants to be 
the thermal process units used to manufacture the refractory products 
(67 FR 42130, June 20, 2002). These included the following:
     Shape dryers, curing ovens, and kilns used to produce clay 
and nonclay (organic resin-bonded) refractory products; and
     shape preheaters, pitch working tanks, defumers, and 
coking ovens used to produce pitch-bonded and pitch-impregnated 
refractory products.
    In addition to these types of thermal process units at major 
sources, we identified other types of thermal process units at area 
source refractory products manufacturing plants not subject to the 
NESHAP. These area sources included those plants that manufactured 
refractory products from refractory ceramic fiber using a melting 
furnace and plants that manufactured refractory products with a fused-
cast process using an electric arc furnace. (67 FR 42112, June 20, 
2002)
    Both HAP and criteria pollutants were identified as emissions from 
the thermal process units. The primary HAP emitted from refractory 
products manufacturing operations were identified as polycylic organic 
matter (POM), phenol, hydrochloric acid (HCl), hydrofluoric acid (HF), 
and ethylene glycol. POM emissions accounted for about 60 percent of 
the total annual HAP emissions, phenol accounted for 13 percent, HF for 
10 percent, HCl for 7 percent and ethylene glycol for 7 percent. (68 FR 
18744, April 16, 2003). The HAP emissions vary and depend on the raw 
materials used, the type of resin or additives used, and the type of 
thermal process unit used. The criteria pollutants emitted from 
refractory products manufacturing facilities include particulate matter 
(PM), sulfur dioxide (SO2), carbon monoxide (CO), nitrogen 
oxides and volatile organic compounds.
    The NESHAP groups refractory product manufacturing processes into 
four subcategories: Clay refractories, nonclay refractories, chromium 
refractories (nonclay), and pitch-impregnated refractories (nonclay).
    A clay refractory product is defined as a refractory product that 
contains at least 10 percent uncalcined clay by weight prior to firing 
in a kiln. In this definition, the term ``clay'' means any of the 
following six classifications of clay defined by the U.S. Geological 
Survey (USGS): Ball clay, bentonite, common clay and shale, fire clay, 
fuller's earth, and kaolin. When clay is used as a raw material, HF and 
HCl emissions are emitted from kilns during firing due to the presence 
of chlorides and fluorides in the clay.
    Nonclay refractories use raw materials such as alumina, magnesium 
oxide, and silicon carbide and typically require phenolic resins and 
other additives to hold the raw materials together. The phenolic resins 
and additives are needed to bind the raw materials and can result in 
organic HAP emissions from the curing ovens and kilns.
    Kilns that are used to fire chromium refractory products can emit 
particulate chromium and other HAP metals. A chromium refractory 
product is a refractory product that contains at least 1 percent 
chromium by weight. The 2002 proposal (67 FR 42122) also identified 
inorganic HAP emissions from chromium refractory products kilns, which 
included hexavalent chromium, other chromium compounds, and other 
nonvolatile HAP metals.
    Pitch-bonded and pitch-impregnated processes employ the use of coal 
tar and petroleum pitch, resulting in the emissions of POM from the 
curing and coking ovens, kilns, defumers, pitch working tanks, and 
shape preheaters.
    In this action, the EPA estimates that a total of approximately 120 
refractory products manufacturing plants are currently operating in the 
U.S. and three are major sources subject to the Refractory Products 
Manufacturing NESHAP. The three major sources manufacture clay and 
nonclay refractory products and can be grouped into the clay and 
nonclay subcategories. We also identified the same primary sources of 
HAP emissions at these refractory products manufacturing plants as the 
thermal process units used to manufacture the refractory products, 
including the shape dryers, curing ovens, and kilns used to produce 
clay and nonclay (organic resin-bonded) refractory products. The three 
major sources currently operating in the U.S. do not produce chromium, 
pitch-bonded, or pitch-impregnated products. Consequently, the thermal 
process units associated with these types of refractories (i.e., shape 
preheaters, pitch working tanks, defumers, and coking ovens used to 
produce pitch-bonded and pitch-impregnated refractory products) are not 
used in the production of refractory products by the three major source 
facilities, and the HAP associated with these thermal process units are 
not emitted by the three major source facilities, except for trace 
amounts of POM. The primary HAP identified for the three major source 
facilities in this action are HCl and HF. Trace amounts of benzene, 
bis(2-ethylhexyl) phthalate, POM, and phenol are also reported to be 
emitted by these facilities from the phenolic resins and additives.
3. NESHAP Requirements for Control of HAP
    The EPA estimated that the Refractory Products Manufacturing NESHAP 
requirements would reduce the emissions of HAP from the source category 
by 137 tpy (68 FR 18730, April 16, 2003). The Refractory Products 
Manufacturing NESHAP specifies emission limits, operating limits, and 
work practice standards for existing affected thermal process sources 
and for new and reconstructed affected thermal process sources that 
emit organic HAP according to refractory product type.
    Existing and new nonclay refractories thermal process sources have 
two options for meeting a total hydrocarbon (THC) limit, to either (1) 
meet a THC concentration limit of 20 parts per million by volume, dry 
basis (ppmvd), corrected to 18 percent oxygen, or (2) reduce the THC 
mass emissions by at least 95 percent. Compliance with the THC emission 
limit is calculated differently for continuous and batch thermal 
process sources. For continuous process sources of organic HAP, 
compliance is based on meeting the THC emission limit as a 3-hour block 
average, and for batch process sources, compliance is based on meeting 
the THC emission limit as the average of 3-hour peak THC emission 
periods over two test runs.
    Existing clay refractories and existing and new chromium refractory 
products kilns are required to use natural gas or equivalent fuel to 
limit metal HAP. Existing clay refractory product kilns must use 
natural gas to limit HF and HCl emissions. Natural gas or equivalent 
fuel must be used as the kiln fuel at all

[[Page 3085]]

times except during periods of natural gas curtailment or other times 
when natural gas is not available.
    New clay refractory product kilns are required to meet numeric 
limits for HF and HCl. For new continuous clay refractory product 
kilns, the HF limit is 0.038 pounds per ton (lb/ton) of uncalcined clay 
processed or a reduction in HF mass emissions by at least 90 percent 
and an HCl limit of 0.18 lb/ton of product or a reduction of 
uncontrolled HCl emissions by at least 30 percent. For new batch clay 
refractory product kilns, the NESHAP requires a reduction in HF 
emissions by at least 90 percent and a reduction in HCl emissions by at 
least 30 percent.
    The NESHAP also establishes operating limits for thermal process 
sources and control devices, which are based on operating parameters 
established during performance testing. For thermal process sources 
emitting organic HAP, the NESHAP requires operating limits on the 
organic HAP processing rate and the operating temperature of the 
control devices (thermal and catalytic oxidizers). For new clay 
refractory products kilns, operating limits are specified for control 
devices, such as dry limestone absorber, dry lime injection fabric 
filters, dry lime scrubber/fabric filters, and wet scrubbers. The 
NESHAP also requires an operation, maintenance and monitoring (OM&M) 
plan for each continuous parameter monitoring system (CPMS).
    The NESHAP also establishes work practice standards for thermal 
process sources associated with pitch-bonded and pitch-impregnated 
refractory product operations. As stated above, these refractory 
products are not manufactured by the three major sources currently 
operating in the U.S.

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

    For the risk modeling portion of this RTR, the EPA used industry-
supplied data and data from the 2017 NEI. The NEI is a database that 
contains information about sources that emit criteria air pollutants, 
their precursors, and HAP. The database includes estimates of annual 
air pollutant emissions from point, nonpoint, and mobile sources in the 
50 states, the District of Columbia, Puerto Rico, and the U.S. Virgin 
Islands. The EPA collects this information and releases an updated 
version of the NEI database every 3 years. The NEI includes the data 
necessary for conducting risk modeling, including annual HAP emissions 
estimates from individual emission points at facilities and the 
associated emission release parameters. We used NEI emissions and data 
supplied by the three major source facilities as the primary data to 
develop the model input files for the risk assessment for this source 
category. Detailed information on the development of the modeling file 
for the Refractory Products Manufacturing source category can be found 
in the memorandum titled Emissions Data Used to Develop the Refractory 
Products Manufacturing Risk and Technology Review (RTR) Risk Modeling 
Input Files, in Appendix 1 to the Residual Risk Assessment for the 
Refractory Products Manufacturing Source Category in Support of the 
2020 Risk and Technology Review Proposed Rule (hereafter referred to as 
the Refractory Products Risk Assessment Report), in the Refractory 
Products Manufacturing Docket (Docket ID No. EPA-HQ-OAR-2020-0148).
    For both the risk modeling and technology review portions of this 
RTR, we gathered additional data from the facilities, including stack 
test reports and operating permits regarding emission points, air 
pollution control devices, and process operations. We collected permits 
and supporting documentation directly from state permitting authorities 
or through state-maintained online databases. We contacted facility 
representatives directly to confirm and clarify the sources of 
emissions that were reported in the NEI. No formal ICR was conducted 
for this action.
    The EPA's ECHO database was used to identify facilities that were 
potentially subject to the NESHAP. The ECHO database provides 
integrated compliance and enforcement information for approximately 
800,000 regulated facilities nationwide. Using the search feature in 
ECHO, the EPA identified facilities that could potentially be subject 
to the NESHAP. We then reviewed operating permits for these facilities 
to confirm that they were major sources of HAP with emission sources 
subject to the NESHAP that is the subject of this action.
    For the technology review, we reviewed various information sources 
regarding emission sources that are currently regulated by the 
Refractory Products Manufacturing NESHAP to support the technology 
review. The information sources included the Reasonably Available 
Control Technology/Best Available Control Technology/Lowest Achievable 
Emission Rate Clearinghouse (RBLC); state regulations; facility 
operating permits; regulatory actions, including technology reviews 
promulgated for other similar NESHAP subsequent to the Surface Coating 
of Metal Cans NESHAP; and discussions with individual refractory 
product manufacturing facilities. As a result of the technology review, 
we are proposing additional control measures based on the best 
practices of one facility in the source category. Additional 
information about the data collection activities for the technology 
review and the technology review results are discussed in section IV.D 
of this preamble and in the technology review memorandum titled 
Technology Review for the Refractory Products Manufacturing Source 
Category, July 2020 (hereafter referred to as the Refractory Products 
Technology Review Memo), available in Docket ID No. EPA-HQ-OAR-2020-
0148.

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

    We also reviewed the NESHAP for other similar source categories 
that were promulgated after the Refractory Products Manufacturing 
NESHAP as part of the technology review for this source category. We 
reviewed the regulatory requirements and/or technical analyses 
associated with these later regulatory actions to identify any 
practices, processes, and control technologies considered in those 
rulemakings that could be applied to emission sources in the Refractory 
Products Manufacturing source category, as well as the costs, non-air 
impacts, and energy implications associated with the use of those 
technologies. We also reviewed information available in industry trade 
publications such as the Refractories World Forum. These publications 
provided information on trends in refractory technologies that can 
affect emissions from the Refractory Products Manufacturing source 
category. This literature review did not identify industry trends that 
would affect emissions from the sources subject to this NESHAP. 
Additional details regarding our review of these information sources 
are contained in the memorandum, Technology Review for Refractory 
Products Manufacturing NESHAP, available in Docket ID No. EPA-HQ-OAR-
2020-0148.

III. Analytical Procedures and Decision-Making

    In this section, we describe the analyses performed to support the 
proposed decisions for the RTRs 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

[[Page 3086]]

under CAA section 112(f)(2), we apply a two-step approach 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). 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 emissions of HAP 
that are carcinogens 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.\3\ The assessment also provides estimates of the distribution 
of cancer risk within the exposed populations, cancer incidence, and an 
evaluation of the potential for an adverse environmental effect. The 
scope of the EPA's risk analysis is consistent with the explanation in 
EPA's response to comments on our policy under the Benzene NESHAP:
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    \3\ 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 HAP 
exposure concentration to the noncancer dose-response value; the HI 
is the sum of HQs for HAP that affect the same target organ or organ 
system.

    The policy chosen by the Administrator permits consideration of 
multiple measures of health risk. Not only can the MIR figure be 
considered, but also incidence, the presence of 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 his 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 his judgment, believes are 
---------------------------------------------------------------------------
appropriate to determining what will ``protect the public health.''

(54 FR at 38057). Thus, the level of the MIR is only one factor to be 
weighed in determining acceptability of risk. 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 an MIR less than the presumptively acceptable level 
is unacceptable in the light of other health risk factors.'' Id. at 
38045. In other words, risks that include an MIR above 100-in-1 million 
may be determined to be acceptable, and risks with an MIR below that 
level may be determined to be unacceptable, depending on all of the 
available health information. Similarly, with regard to the ample 
margin of safety analysis, the EPA stated in the Benzene NESHAP that 
the: ``EPA believes the relative weight of the many factors that can be 
considered in selecting an ample margin of safety can only be 
determined for each specific source category. This occurs mainly 
because technological and economic factors (along with the health-
related factors) vary from source category to source category.'' 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 the HAP risk 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 risk, 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 an 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.'' \4\
---------------------------------------------------------------------------

    \4\ Recommendations of the SAB Risk and Technology Review 
Methods Panel are provided in their report, which is available at: 
http://yosemite.epa.gov/sab/sabproduct.nsf/
4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf.
---------------------------------------------------------------------------

    In response to the SAB recommendations, the EPA incorporates 
cumulative risk analyses into its RTR risk assessments. The Agency (1) 
Conducts facility-wide assessments, which include source category 
emission points, as well as other emission points within the 
facilities; (2) combines exposures from multiple sources in the same 
category that could affect the same individuals; and (3) for some 
persistent and bioaccumulative pollutants, analyzes the ingestion route 
of exposure. In addition, the RTR risk assessments consider aggregate 
cancer risk from all carcinogens and aggregated noncancer HQs for all 
noncarcinogens affecting the same target organ or target organ system.
    Although we are interested in placing source category and facility-
wide HAP risk in the context of total HAP risk from all sources 
combined in the vicinity of each source, we are concerned about the 
uncertainties of doing so. Estimates of total HAP risk from emission 
sources other than those that we have studied in depth during this RTR 
review would have significantly greater associated uncertainties than 
the source category or

[[Page 3087]]

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 primarily 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, we analyze their 
technical feasibility, estimated costs, energy implications, and non-
air environmental impacts. We also consider the emission reductions 
associated with applying each development. This analysis informs our 
decision of whether it is ``necessary'' to revise the emissions 
standards. In addition, we consider 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 
the NESHAP (i.e., the 2003 Refractory Products Manufacturing NESHAP), 
we review a variety of data sources in our investigation of potential 
practices, processes, or controls. We also review the NESHAP and the 
available data to determine if there are any unregulated emissions of 
HAP within the source category and evaluate this data for use in 
developing new emission standards. See sections II.C and II.D of this 
preamble for information on the specific data sources that were 
reviewed as part of the technology review.

C. How do we estimate post-MACT risk posed by the source category?

    In this section, we provide a complete description of the types of 
analyses that we generally perform during the risk assessment process. 
In some cases, we do not perform a specific analysis because it is not 
relevant. For example, in the absence of emissions of HAP known to be 
persistent and bioaccumulative in the environment (PB-HAP), we would 
not perform a multipathway exposure assessment. Where we do not perform 
an analysis, we state that we do not and provide the reason. While we 
present all of our risk assessment methods, we only present risk 
assessment results for the analyses actually conducted (see section 
IV.B of this preamble).
    The EPA conducts 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 risk 
within the exposed populations, cancer incidence, and an evaluation of 
the potential for an adverse environmental effect. The seven sections 
that follow this paragraph describe how we estimated emissions and 
conducted the risk assessment. The docket for this rulemaking contains 
the following document which provides more information on the risk 
assessment inputs and models: Residual Risk Assessment for the 
Refractory Products Manufacturing Source Category in Support of the 
2020 Risk and Technology Review Proposed Rule. The methods used to 
assess risk (as described in the seven primary steps below) are 
consistent with those described by the EPA in the document reviewed by 
a panel of the EPA's SAB in 2009; \5\ and described in the SAB review 
report issued in 2010. They are also consistent with the key 
recommendations contained in that report.
---------------------------------------------------------------------------

    \5\ U.S. EPA. 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, June 2009. EPA-452/R-09-006. https://www3.epa.gov/airtoxics/rrisk/rtrpg.html.
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1. How did we estimate actual emissions and identify the emissions 
release characteristics?
    The actual emissions and the emission release characteristics for 
one of the three major source facilities were obtained primarily from 
the 2017 NEI. The actual emissions and the emission release 
characteristics for the other two facilities were developed by the EPA 
based on data provided by the facilities and refractory emission 
factors. Additional information on the development of the modeling file 
for each facility, including the development of the actual emissions 
estimates and emissions release characteristics, can be found in the 
memorandum titled Emissions Data Used to Develop the Refractory 
Products Manufacturing Risk and Technology Review (RTR) Risk Modeling 
Input Files, found in Appendix 1 to the Refractory Products Risk 
Assessment Report, available in Docket ID No. EPA-HQ-OAR-2020-0148.
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 allowed under the MACT standards are referred 
to as the ``MACT-allowable'' emissions. We discussed the consideration 
of both MACT-allowable and actual emissions in the final Coke Oven 
Batteries RTR (70 FR 1992, 1998 through 1999, April 15, 2005) and in 
the proposed and final Hazardous Organic NESHAP RTR (71 FR 34421, 
34428, June 14, 2006, and 71 FR 76603, 76609, December 21, 2006, 
respectively). In those actions, we noted that assessing the risk at 
the MACT-allowable level is inherently reasonable since that risk 
reflects 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.)
    For Refractory Products Manufacturing sources with compliance test 
data, we determined allowable emissions by calculating a multiplier for 
each emission source. Based on the data in compliance test reports, we 
calculated the multipliers by comparing actual emissions and control 
efficiencies to the applicable Refractory Products

[[Page 3088]]

Manufacturing NESHAP emission limit. For some sources compliance was 
determined by comparing the concentration of THCs to the emission limit 
of 20 ppmvd, corrected to 18 percent oxygen, and the emissions were 
measured at the outlet of the control device. For other sources, 
compliance was determined by comparing the THC control efficiency to 
the THC control efficiency requirement of 95 percent, and the emissions 
were measured at the inlet and outlet of the control device 
accordingly. For sources without compliance test data, we assumed the 
actual and the allowable emissions were equal. Additional information 
on the development of the allowable emissions can be found in the 
memorandum titled Emissions Data Used to Develop the Refractory 
Products Manufacturing Risk and Technology Review (RTR) Risk Modeling 
Input Files, found in Appendix 1 to the Refractory Products Risk 
Assessment Report, available in Docket ID No. EPA-HQ-OAR-2020-0148.
3. How do we conduct dispersion modeling, determine inhalation 
exposures, and estimate individual and population inhalation risk?
    Both long-term and short-term inhalation exposure concentrations 
and health risk from the source category addressed in this proposal 
were estimated using the Human Exposure Model (HEM-3).\6\ 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 risk 
using the exposure estimates and quantitative dose-response 
information.
---------------------------------------------------------------------------

    \6\ For more information about HEM-3, go to https://www.epa.gov/fera/risk-assessment-and-modeling-human-exposure-model-hem.
---------------------------------------------------------------------------

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.\7\ 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 U.S. and Puerto Rico. A 
second library of U.S. Census Bureau census block \8\ 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 
risk. These are discussed below.
---------------------------------------------------------------------------

    \7\ 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).
    \8\ A census block is the smallest geographic area for which 
census statistics are tabulated.
---------------------------------------------------------------------------

b. Risk From Chronic Exposure to HAP
    In developing the risk assessment for chronic exposures, we use the 
estimated annual average ambient air concentrations of each HAP emitted 
by each source in the source category. The HAP air concentrations at 
each nearby census block centroid located within 50 km of the facility 
are a surrogate for the chronic inhalation exposure concentration for 
all the people who reside in that census block. 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.
    For each facility, we calculate the MIR as the cancer risk 
associated with a continuous lifetime (24 hours per day, 7 days per 
week, 52 weeks per year, 70 years) exposure to the maximum 
concentration at the centroid of each inhabited census block. We 
calculate individual cancer risk by multiplying the estimated lifetime 
exposure to the ambient concentration of each HAP (in micrograms per 
cubic meter ([mu]g/m\3\)) by its unit risk estimate (URE). The URE is 
an upper-bound estimate of an individual's incremental risk 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. The pollutant-specific dose-response values 
used to estimate health risk are available at https://www.epa.gov/fera/dose-response-assessment-assessing-health-risks-associated-exposure-hazardous-air-pollutants.
    To estimate individual lifetime cancer risks associated with 
exposure to HAP emissions from each facility in the source category, we 
sum the risks for each of the carcinogenic HAP \9\ emitted by the 
modeled facility. We estimate cancer risk at every census block within 
50 km of every facility in the source category. The MIR is the highest 
individual lifetime cancer risk estimated for any of those census 
blocks. In addition to calculating the MIR, we estimate the 
distribution of individual cancer risks for the source category by 
summing the number of individuals within 50 km of the sources whose 
estimated risk falls within a specified risk range. We also estimate 
annual cancer incidence by multiplying the estimated lifetime cancer 
risk at each census block by the number of people residing in that 
block, summing results for all of the census blocks, and then dividing 
this result by a 70-year lifetime.
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    \9\ The EPA's 2005 Guidelines for Carcinogen Risk Assessment 
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 risk of these individual compounds to obtain the cumulative 
cancer risk 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 https://yosemite.epa.gov/sab/sabproduct.nsf/214C6E915 BB04E148525 
70CA007A682C/$File/ecadv02001.pdf.
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    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 or target organ 
system to obtain a TOSHI. The HQ is the estimated exposure divided by 
the chronic noncancer dose-response

[[Page 3089]]

value, which is a value selected from one of several sources. The 
preferred chronic noncancer dose-response value is the EPA RfC, defined 
as ``an estimate (with uncertainty spanning perhaps an order of 
magnitude) of a continuous inhalation exposure to the human population 
(including sensitive subgroups) that is likely to be without an 
appreciable risk of deleterious effects during a lifetime'' (https://iaspub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&vocabName=IRIS%20Glossary). In cases where an RfC 
from the EPA's IRIS 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 a value 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 (https://www.atsdr.cdc.gov/mrls/index.asp); (2) the 
CalEPA Chronic Reference Exposure Level (REL) (https://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. The pollutant-specific dose-
response values used to estimate health risks are available at https://www.epa.gov/fera/dose-response-assessment-assessing-health-risks-associated-exposure-hazardous-air-pollutants.
c. 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. As part of our efforts to continually improve our 
methodologies to evaluate the risks that HAP emitted from categories of 
industrial sources pose to human health and the environment,\10\ we 
revised our treatment of meteorological data to use reasonable worst-
case air dispersion conditions in our acute risk screening assessments 
instead of worst-case air dispersion conditions. This revised treatment 
of meteorological data and the supporting rationale are described in 
more detail in Residual Risk Assessment for Refractory Products 
Manufacturing Source Category in Support of the 2020 Risk and 
Technology Review Proposed Rule, and in Appendix 5 of the report: 
Technical Support Document for Acute Risk Screening Assessment. This 
revised approach has been used in this proposal and in all other RTR 
rulemakings proposed on or after June 3, 2019.
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    \10\ See, e.g., U.S. EPA. Screening Methodologies to Support 
Risk and Technology Reviews (RTR): A Case Study Analysis (Draft 
Report, May 2017. https://www.epa.gov/stationary-sources-air-pollution/risk-and-technology-review-national-emissions-standards-hazardous).
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    To assess the potential acute risk to the maximally exposed 
individual, we use the peak hourly emission rate for each emission 
point,\11\ reasonable worst-case air dispersion conditions (i.e., 99th 
percentile), and the point of highest off-site exposure. Specifically, 
we assume that peak emissions from the source category and reasonable 
worst-case air dispersion conditions co-occur and that a person is 
present at the point of maximum exposure.
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    \11\ 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 factor (either a 
category-specific factor or a default factor of 10) to account for 
variability. This is documented in Residual Risk Assessment for 
Refractory Products Manufacturing Source Category in Support of the 
2020 Risk and Technology Review Proposed Rule, and in Appendix 5 of 
the report: Technical Support Document for Acute Risk Screening 
Assessment. Both are available in the docket for this rulemaking.
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    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 concentration 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.'' \12\ 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.\13\ 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 nonsensory effects. However, the effects are not 
disabling and are transient and reversible upon cessation of 
exposure.'' The document also notes that ``Airborne concentrations 
below AEGL-1 represent exposure levels that can produce mild and 
progressively increasing but transient and nondisabling odor, taste, 
and sensory irritation or certain asymptomatic, nonsensory effects.'' 
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.
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    \12\ 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 https://oehha.ca.gov/air/general-info/oehha-acute-8-hour-and-chronic-reference-exposure-level-rel-summary.
    \13\ National Academy of Sciences, 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).
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    ERPGs are ``developed for emergency planning and are intended as 
health-based guideline concentrations for single exposures to 
chemicals.'' \14\ 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

[[Page 3090]]

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.
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    \14\ 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.
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    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 estimated acute emissions by 
determining acute multipliers, which we then multiplied by the actual 
emissions. The acute multipliers for all sources were based on data 
from compliance tests for the specific sources, when available. For the 
batch processes, which were tested for 8 to 18 hours, we determined the 
acute multiplier by calculating mass emissions for each hour of the 
test and then taking the ratio of the maximum hourly emission rate to 
the average hourly emission rate. For sources that were tested for 
three 1-hour test runs, we determined the acute multiplier as the ratio 
of the mass emissions for the highest test run to the three-run 
average. The acute emissions were converted from ton per hour to ton 
per year for the risk modeling input file using 8,760 hours per year. 
If compliance test results were not available, we applied source 
specific acute multipliers developed for other similar sources to 
estimate the acute emissions. Additional information on the development 
of the acute emissions can be found in the memorandum titled Emissions 
Data Used to Develop the Refractory Products Manufacturing Risk and 
Technology Review (RTR) Risk Modeling Input Files, found in Appendix 1 
to the Refractory Products Risk Assessment Report, available in Docket 
ID No. EPA-HQ-OAR-2020-0148.
    In our acute inhalation screening risk assessment, acute impacts 
are deemed negligible for HAP for which acute HQs are less than or 
equal to 1, and no further analysis is performed for these HAP. In 
cases where an acute HQ from the screening step is greater than 1, we 
assess the site-specific data to ensure that the acute HQ is at an off-
site location.
4. How do we conduct the multipathway exposure and risk screening 
assessment?
    The EPA conducts 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 determine 
whether any sources in the source category emit any HAP known to be 
persistent and bioaccumulative in the environment, as identified in the 
EPA's Air Toxics Risk Assessment Library (see Volume 1, Appendix D, at 
https://www.epa.gov/fera/risk-assessment-and-modeling-air-toxics-risk-assessment-reference-library).
    For the Refractory Products Manufacturing source category, we 
identified PB-HAP emissions of arsenic, cadmium, POM, mercury (divalent 
mercury and methyl mercury) and lead, so we proceeded to the next step 
of the evaluation. Except for lead, the human health risk screening 
assessment for PB-HAP consists of three progressive tiers. In a Tier 1 
screening assessment, we determine whether the magnitude of the 
facility-specific emissions of PB-HAP warrants further evaluation to 
characterize human health risk through ingestion exposure. To 
facilitate this step, we evaluate emissions against previously 
developed screening threshold emission rates for several PB-HAP that 
are based on a hypothetical upper-end screening exposure scenario 
developed for use in conjunction with the EPA's Total Risk Integrated 
Methodology Fate, Transport, and Ecological Exposure (TRIM.FaTE) model. 
The PB-HAP with screening threshold emission rates are arsenic 
compounds, cadmium compounds, chlorinated dibenzodioxins and furans, 
mercury compounds, and POM. Based on the EPA estimates of toxicity and 
bioaccumulation potential, these pollutants represent a conservative 
list for inclusion in multipathway risk assessments for RTR rules. (See 
Volume 1, Appendix D at https://www.epa.gov/sites/production/files/2013-08/documents/volume_1_reflibrary.pdf.) In this assessment, we 
compare the facility-specific emission rates of these PB-HAP to the 
screening threshold emission rates for each PB-HAP to assess the 
potential for significant human health risks via the ingestion pathway. 
We call this application of the TRIM.FaTE model the Tier 1 screening 
assessment. The ratio of a facility's actual emission rate to the Tier 
1 screening threshold emission rate is a ``screening value (SV).''
    We derive the Tier 1 screening threshold emission rates for these 
PB-HAP (other than lead compounds) to correspond to a maximum excess 
lifetime cancer risk of 1-in-1 million (i.e., for arsenic compounds, 
polychlorinated dibenzodioxins and furans, and POM) or, for HAP that 
cause noncancer health effects (i.e., cadmium compounds and mercury 
compounds), a maximum HQ of 1. If the emission rate of any one PB-HAP 
or combination of carcinogenic PB-HAP in the Tier 1 screening 
assessment exceeds the Tier 1 screening threshold emission rate for any 
facility (i.e., the SV is greater than 1), we conduct a second 
screening assessment, which we call the Tier 2 screening assessment. 
The Tier 2 screening assessment separates the Tier 1 combined fisher 
and farmer exposure scenario into fisher, farmer, and gardener 
scenarios that retain upper-bound ingestion rates.
    In the Tier 2 screening assessment, the location of each facility 
that exceeds a Tier 1 screening threshold emission rate is used to 
refine the assumptions associated with the Tier 1 fisher and farmer 
exposure scenarios at that facility. A key assumption in the Tier 1 
screening assessment is that a lake and/or farm is located near the 
facility. As part of the Tier 2 screening assessment, we use a USGS 
database to identify actual waterbodies within 50 km of each facility 
and assume the fisher only consumes fish from lakes within that 50 km 
zone. We also examine the differences between local meteorology near 
the facility and the meteorology used in the Tier 1 screening 
assessment. We then adjust the previously-developed Tier 1 screening 
threshold emission rates for each PB-HAP for each facility based on an 
understanding of how exposure concentrations estimated for the 
screening scenario change with the use of local meteorology and USGS 
lakes database.
    In the Tier 2 farmer scenario, we maintain an assumption that the 
farm is located within 0.5 km of the facility and that the farmer 
consumes meat, eggs, dairy, vegetables, and fruit produced near the 
facility. We may further refine the Tier 2 screening analysis by 
assessing a gardener scenario to characterize a range of exposures, 
with the gardener scenario being more plausible in RTR evaluations. 
Under the gardener scenario, we assume the gardener consumes home-
produced eggs, vegetables, and fruit products at the same ingestion 
rate as the farmer. The Tier 2 screen continues to rely on

[[Page 3091]]

the high-end food intake assumptions that were applied in Tier 1 for 
local fish (adult female angler at 99th percentile fish consumption 
\15\) and locally grown or raised foods (90th percentile consumption of 
locally grown or raised foods for the farmer and gardener scenarios 
\16\). If PB-HAP emission rates do not result in a Tier 2 SV greater 
than 1, we consider those PB-HAP emissions to pose risks below a level 
of concern. If the PB-HAP emission rates for a facility exceed the Tier 
2 screening threshold emission rates, we may conduct a Tier 3 screening 
assessment.
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    \15\ Burger, J. 2002. Daily consumption of wild fish and game: 
Exposures of high end recreationists. International Journal of 
Environmental Health Research, 12:343-354.
    \16\ U.S. EPA. Exposure Factors Handbook 2011 Edition (Final). 
U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-09/
052F, 2011.
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    There are several analyses that can be included in a Tier 3 
screening assessment, depending upon the extent of refinement 
warranted, including validating that the lakes are fishable, locating 
residential/garden locations for urban and/or rural settings, 
considering plume-rise to estimate emissions lost above the mixing 
layer, and considering hourly effects of meteorology and plume-rise on 
chemical fate and transport (a time-series analysis). If necessary, the 
EPA may further refine the screening assessment through a site-specific 
assessment.
    In evaluating the potential multipathway risk from emissions of 
lead compounds, rather than developing a screening threshold emission 
rate, we compare maximum estimated chronic inhalation exposure 
concentrations to the level of the current National Ambient Air Quality 
Standard (NAAQS) for lead.\17\ Values below the level of the primary 
(health-based) lead NAAQS are considered to have a low potential for 
multipathway risk.
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    \17\ In doing so, the EPA notes that the legal standard for a 
primary NAAQS--that a standard is requisite to protect public health 
and provide an adequate margin of safety (CAA section 109(b))--
differs from the CAA section 112(f) standard (requiring, among other 
things, that the standard provide an ``ample margin of safety to 
protect public health''). However, the primary lead NAAQS is a 
reasonable measure of determining risk acceptability (i.e., the 
first step of the Benzene NESHAP analysis) since it is designed to 
protect the most susceptible group in the human population--
children, including children living near major lead emitting 
sources. 73 FR 67002/3; 73 FR 67000/3; 73 FR 67005/1. In addition, 
applying the level of the primary lead NAAQS at the risk 
acceptability step is conservative, since that primary lead NAAQS 
reflects an adequate margin of safety.
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    For further information on the multipathway assessment approach, 
see the Refractory Products Risk Assessment Report, which is available 
in the docket for this action.
5. How do we conduct the environmental risk screening assessment?
a. Adverse Environmental Effect, Environmental HAP, and Ecological 
Benchmarks
    The EPA conducts a screening assessment to examine the potential 
for an adverse environmental effect 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, POM, mercury (both 
inorganic mercury and methyl mercury), and lead compounds. The acid 
gases included in the screening assessment are HCl and 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, are 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 (NOAEL). 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 Refractory Products 
Risk Assessment Report, 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 facilities in the Refractory Products 
Manufacturing source category emitted any of the environmental HAP. For 
the Refractory Products Manufacturing source category, we identified 
emissions of arsenic, cadmium, HCl, HF, lead, mercury (divalent mercury 
and methyl mercury), and POM. Because one or more of the environmental 
HAP evaluated are emitted by at least one facility in the source 
category, we proceeded to the second step of the evaluation.
c. PB-HAP Methodology
    The environmental screening assessment includes six PB-HAP, arsenic 
compounds, cadmium compounds, dioxins/furans, POM, mercury (both 
inorganic mercury and methyl mercury), and lead compounds. With the 
exception of lead, the environmental risk screening assessment for PB-
HAP consists of three tiers. The first tier of the environmental risk 
screening assessment uses the same health-protective conceptual model 
that is used for the Tier 1 human health screening assessment. 
TRIM.FaTE model simulations were used to back-calculate Tier 1 
screening threshold emission rates. The screening threshold emission 
rates represent the emission rate in tons of pollutant per year that 
results in media concentrations at the facility that equal the relevant 
ecological benchmark. To assess emissions from each facility in the 
category, the reported emission rate for each PB-HAP was compared to 
the Tier 1 screening threshold emission rate for that PB-HAP for each 
assessment endpoint and effect level. If emissions from a facility do 
not exceed the Tier 1 screening threshold emission rate, the facility 
``passes'' the screening assessment, and, therefore, is not evaluated 
further under the screening approach. If emissions from a facility 
exceed the Tier 1 screening

[[Page 3092]]

threshold emission rate, we evaluate the facility further in Tier 2.
    In Tier 2 of the environmental screening assessment, the screening 
threshold emission rates are adjusted to account for local meteorology 
and the actual location of lakes in the vicinity of facilities that did 
not pass the Tier 1 screening assessment. For soils, we evaluate the 
average soil concentration for all soil parcels within a 7.5-km radius 
for each facility and PB-HAP. For the water, sediment, and fish tissue 
concentrations, the highest value for each facility for each pollutant 
is used. If emission concentrations from a facility do not exceed the 
Tier 2 screening threshold emission rate, the facility ``passes'' the 
screening assessment and typically is not evaluated further. If 
emissions from a facility exceed the Tier 2 screening threshold 
emission rate, we evaluate the facility further in Tier 3.
    As in the multipathway human health risk assessment, in Tier 3 of 
the environmental screening assessment, we examine the suitability of 
the lakes around the facilities to support life and remove those that 
are not suitable (e.g., lakes that have been filled in or are 
industrial ponds), adjust emissions for plume-rise, and conduct hour-
by-hour time-series assessments. If these Tier 3 adjustments to the 
screening threshold emission rates still indicate the potential for an 
adverse environmental effect (i.e., facility emission rate exceeds the 
screening threshold emission rate), we may elect to conduct a more 
refined assessment using more site-specific information. If, after 
additional refinement, the facility emission rate still exceeds the 
screening threshold emission rate, the facility may have the potential 
to cause an adverse environmental effect.
    To evaluate the potential for an adverse environmental effect from 
lead, we compared the average modeled air concentrations (from HEM-3) 
of lead around each facility in the source category to the level of the 
secondary NAAQS for lead. The secondary lead NAAQS is a reasonable 
means of evaluating environmental risk because it is set to provide 
substantial protection against adverse welfare effects which can 
include ``effects on soils, water, crops, vegetation, man-made 
materials, animals, wildlife, weather, visibility and climate, damage 
to and deterioration of property, and hazards to transportation, as 
well as effects on economic values and on personal comfort and well-
being.''
d. Acid Gas Environmental Risk Methodology
    The environmental screening assessment for acid gases evaluates the 
potential phytotoxicity and reduced productivity of plants due to 
chronic exposure to HF and HCl. The environmental risk screening 
methodology for acid gases is a single-tier screening assessment that 
compares modeled ambient air concentrations (from AERMOD) to the 
ecological benchmarks for each acid gas. To identify a potential 
adverse environmental effect (as defined in section 112(a)(7) of the 
CAA) from emissions of HF and HCl, we evaluate the following metrics: 
The size of the modeled area around each facility that exceeds the 
ecological benchmark for each acid gas, in acres and square kilometers; 
the percentage of the modeled area around each facility that exceeds 
the ecological benchmark for each acid gas; and the area-weighted 
average SV around each facility (calculated by dividing the area-
weighted average concentration over the 50-km modeling domain by the 
ecological benchmark for each acid gas). For further information on the 
environmental screening assessment approach, see Appendix 9 of the 
Refractory Products Risk Assessment Report, which is available in the 
docket for this action.
6. How do 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 compiled from the 2017 NEI. The source category records 
of that NEI dataset were removed, evaluated, and updated as described 
in section II.C of this preamble: What data collection activities were 
conducted to support this action? Once a quality assured source 
category dataset was available, it was placed back with the remaining 
records from the NEI for that facility. The facility-wide file was then 
used to analyze 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, the 
modeled source category risks were compared to the facility-wide risks 
to determine the portion of the 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 Refractory 
Products Risk Assessment Report, 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 do 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 
health and environmentally protective. 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 Refractory Products Risk 
Assessment Report, which is available in the docket for this action. If 
a multipathway site-specific assessment was performed for this source 
category, a full discussion of the uncertainties associated with that 
assessment can be found in Appendix 11 of that document, Site-Specific 
Human Health Multipathway Residual Risk Assessment Report.
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 reflect short-term fluctuations based on actual emissions 
testing data. The estimates of peak hourly emission

[[Page 3093]]

rates for the acute effects screening assessment were also based on 
actual emissions testing data.
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 risk 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 Guidelines for Carcinogen Risk Assessment; 
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'' (the EPA's 2005 
Guidelines for Carcinogen Risk Assessment, pages 1 through 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.\18\ 
That is, they represent a ``plausible upper limit to the true value of 
a quantity'' (although this is usually not a true statistical 
confidence limit). In some circumstances, the true risk could be as low 
as zero; however, in other circumstances the risk could be greater.\19\ 
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,\20\ 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.
---------------------------------------------------------------------------

    \18\ IRIS glossary (https://ofmpub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&glossaryName=IRIS%20Glossary).
    \19\ 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.
    \20\ See A Review of the Reference Dose and Reference 
Concentration Processes, U.S. EPA, December 2002, and Methods for 
Derivation of Inhalation Reference Concentrations and Application of 
Inhalation Dosimetry, U.S. EPA, 1994.
---------------------------------------------------------------------------

    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 we make every effort 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

[[Page 3094]]

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 a 
person. In the acute screening assessment that we conduct under the RTR 
program, we assume that peak emissions from the source category and 
reasonable worst-case air dispersion conditions (i.e., 99th percentile) 
co-occur. We then include the additional assumption that a person is 
located at this point at the same time. Together, these assumptions 
represent a reasonable worst-case actual exposure scenario. In most 
cases, it is unlikely that a person would be located at the point of 
maximum exposure during the time when peak emissions and reasonable 
worst-case air dispersion conditions occur simultaneously.
f. Uncertainties in the Multipathway and Environmental Risk Screening 
Assessments
    For each source category, we generally rely on site-specific levels 
of PB-HAP or environmental HAP emissions to determine whether a refined 
assessment of the impacts from multipathway exposures is necessary or 
whether it is necessary to perform an environmental screening 
assessment. This determination is based on the results of a three-
tiered screening assessment that relies on the outputs from models--
TRIM.FaTE and AERMOD--that estimate environmental pollutant 
concentrations and human exposures for five PB-HAP (dioxins, POM, 
mercury, cadmium, and arsenic) and two acid gases (HF and HCl). For 
lead, we use AERMOD to determine ambient air concentrations, which are 
then compared to the secondary NAAQS standard for lead. Two important 
types of uncertainty associated with the use of these models in RTR 
risk assessments and inherent to any assessment that relies on 
environmental modeling are model uncertainty and input uncertainty.\21\
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    \21\ In the context of this discussion, the term ``uncertainty'' 
as it pertains to exposure and risk encompasses both variability in 
the range of expected inputs and screening results due to existing 
spatial, temporal, and other factors, as well as uncertainty in 
being able to accurately estimate the true result.
---------------------------------------------------------------------------

    Model uncertainty concerns whether the model adequately represents 
the actual processes (e.g., movement and accumulation) that might occur 
in the environment. For example, does the model adequately describe the 
movement of a pollutant through the soil? This type of uncertainty is 
difficult to quantify. However, based on feedback received from 
previous EPA SAB reviews and other reviews, we are confident that the 
models used in the screening assessments are appropriate and state-of-
the-art for the multipathway and environmental screening risk 
assessments conducted in support of RTRs.
    Input uncertainty is concerned with how accurately the models have 
been configured and parameterized for the assessment at hand. For Tier 
1 of the multipathway and environmental screening assessments, we 
configured the models to avoid underestimating exposure and risk. This 
was accomplished by selecting upper-end values from nationally 
representative datasets for the more influential parameters in the 
environmental model, including selection and spatial configuration of 
the area of interest, lake location and size, meteorology, surface 
water, soil characteristics, and structure of the aquatic food web. We 
also assume an ingestion exposure scenario and values for human 
exposure factors that represent reasonable maximum exposures.
    In Tier 2 of the multipathway and environmental screening 
assessments, we refine the model inputs to account for meteorological 
patterns in the vicinity of the facility versus using upper-end 
national values, and we identify the actual location of lakes near the 
facility rather than the default lake location that we apply in Tier 1. 
By refining the screening approach in Tier 2 to account for local 
geographical and meteorological data, we decrease the likelihood that 
concentrations in environmental media are overestimated, thereby 
increasing the usefulness of the screening assessment. In Tier 3 of the 
screening assessments, we refine the model inputs again to account for 
hour-by-hour plume-rise and the height of the mixing layer. We can also 
use those hour-by-hour meteorological data in a TRIM.FaTE run using the 
screening configuration corresponding to the lake location. These 
refinements produce a more accurate estimate of chemical concentrations 
in the media of interest, thereby reducing the uncertainty with those 
estimates. The assumptions and the associated uncertainties regarding 
the selected ingestion exposure scenario are the same for all three 
tiers.
    For the environmental screening assessment for acid gases, we 
employ a single-tiered approach. We use the modeled air concentrations 
and compare those with ecological benchmarks.
    For all tiers of the multipathway and environmental screening 
assessments, our approach to addressing model input uncertainty is 
generally cautious. We choose model inputs from the upper end of the 
range of possible values for the influential parameters used in the 
models, and we assume that the exposed individual exhibits ingestion 
behavior that would lead to a high total exposure. This approach 
reduces the likelihood of not identifying high risks for adverse 
impacts.
    Despite the uncertainties, when individual pollutants or facilities 
do not exceed screening threshold emission rates (i.e., screen out), we 
are confident that the potential for adverse multipathway impacts on 
human health is very low. On the other hand, when individual pollutants 
or facilities do exceed screening threshold emission rates, it does not 
mean that impacts are significant, only that we cannot rule out that 
possibility and that a refined assessment for the site might be 
necessary to obtain a more accurate risk characterization for the 
source category.
    The EPA evaluates the following HAP in the multipathway and/or 
environmental risk screening assessments, where applicable: Arsenic, 
cadmium, dioxins/furans, lead, mercury (both inorganic and methyl 
mercury), POM, HCl, and HF. These HAP represent pollutants that can 
cause adverse impacts either through direct exposure to HAP in the air 
or through exposure to HAP that are deposited

[[Page 3095]]

from the air onto soils and surface waters and then through the 
environment into the food web. These HAP represent those HAP for which 
we can conduct a meaningful multipathway or environmental screening 
risk assessment. For other HAP not included in our screening 
assessments, the model has not been parameterized such that it can be 
used for that purpose. In some cases, depending on the HAP, we may not 
have appropriate multipathway models that allow us to predict the 
concentration of that pollutant. The EPA acknowledges that other HAP 
beyond these that we are evaluating may have the potential to cause 
adverse effects and, therefore, the EPA may evaluate other relevant HAP 
in the future, as modeling science and resources allow.

IV. Analytical Results and Proposed Decisions

A. What actions are we taking pursuant to CAA sections 112(d)(2) and 
(d)(3)?

    In this action, we are proposing standards for previously 
unregulated HAP for existing sources in the clay and nonclay refractory 
subcategories pursuant to CAA sections 112(d)(2) and (3).\22\ For 
existing clay refractory sources, we are proposing a MACT floor limit 
for (non-mercury) metal HAP and a MACT floor limit for mercury (in 
addition to the existing NESHAP work practice standard to use natural 
gas as fuel for existing clay refractory sources). For existing nonclay 
refractory sources, we are proposing a work practice standard to use 
natural gas as fuel to limit metal HAP emissions as provided in CAA 
section 112(h) in lieu of a numerical emissions standard (in addition 
to the existing NESHAP THC limit for existing nonclay refractory 
sources).
---------------------------------------------------------------------------

    \22\ The EPA not only has authority under CAA sections 112(d)(2) 
and (3) to set MACT standards for previously unregulated HAP 
emissions at any time, but is required to address any previously 
unregulated HAP emissions as part of its periodic review of MACT 
standards under CAA section 112(d)(6). LEAN v. EPA, 955 F3d at 1091-
1099.
---------------------------------------------------------------------------

    The results and proposed decisions based on the analyses performed 
pursuant to CAA sections 112(d)(2) and (3) are presented below.
1. Clay Refractory Products
a. Background
    For existing clay refractory sources, the 2002 Refractory Products 
Manufacturing NESHAP proposal preamble identifies the primary HAP 
emissions as HF and HCl from the manufacture of clay products. The 
NESHAP requires control of HF/HCl with a work practice to use natural 
gas as a clean fuel replacement for coal, fuel oil, and waste-derived 
fuels that were used in kilns and ovens at that time. More recent 
available data in emission test reports for these sources reviewed for 
this action confirm trace (but measurable) amounts of (non-mercury) 
metal HAP and mercury emissions. Based on this data, we are proposing 
MACT floor limits for these HAP for new and existing clay refractory 
sources. We propose to set a limit for mercury and a limit for PM as a 
surrogate for (non-mercury) metal HAP. We are setting a limit for PM as 
a surrogate for (non-mercury) metal HAP because the metal HAP are 
contained in the PM and the control techniques that would be used to 
control PM will equally control (non-mercury) metal HAP. We have used 
PM as a surrogate for (non-mercury) metal HAP for other rules with 
similar processes (e.g., Portland Cement Manufacturing, Lime 
Manufacturing, Clay Ceramics Manufacturing).
b. Proposed MACT Standards
    Pursuant to CAA section 112(d)(3), we are proposing MACT floor 
limits of 9.5 pounds per hour for PM and 18 micrograms per dry standard 
cubic meter ([micro]g/dscm), corrected to 18 percent oxygen, for 
mercury from each existing kiln that is used to produce clay refractory 
products. Because there are fewer than 30 kilns used to produce clay 
refractory products in the source category, CAA section 112(d)(3)(B) 
directs the EPA to base the MACT floor on the best performing five 
sources for which the EPA has data. For the clay refractory kiln 
subcategory, we had data for only two clay refractory kilns, so we 
considered all sources for which we had data as the best performing 
sources in the subcategory. To calculate the limits, we used the test 
data from the two clay refractory kilns to calculate the average 
emissions for each kiln. We then determined upper prediction limits 
(UPLs) that incorporate the potential variability in future 
measurements to develop the PM and mercury standards.
    Pursuant to CAA section 112(d)(3) requirements for new sources, the 
standard for new sources shall not be less stringent than the emission 
control that is achieved in practice by the best controlled similar 
source. We are proposing MACT floor limits of 3.1 pounds per hour for 
PM and 6.1 [micro]g/dscm, corrected to 18 percent oxygen, for mercury 
from each new kiln that is used to produce clay refractory products. 
These limits were derived using the same test data as the existing 
source limits but are based on the UPL determinations for the best-
performing kiln rather than both existing kilns for which we have data.
    The EPA's MACT analyses use the UPL approach to identify the 
average emission limitation achieved by the best performing sources. 
The EPA uses this approach because it incorporates the average 
performance of the best performing sources as well as the variability 
of the performance during testing conditions. The UPL represents the 
value which one can expect the mean of a specified number of future 
observations (e.g., 3-run average) to fall below for the specified 
level of confidence (99 percent), based upon the results from the same 
population. In other words, the UPL estimates what the upper bound of 
future values will be based upon present or past background data. The 
UPL approach encompasses all the data point-to-data point variability 
in the collected data, as derived from the dataset to which it is 
applied. For more details regarding how these limits were derived, see 
the technical memorandum titled Development of Proposed Standards and 
Impacts for the Refractory Products Manufacturing NESHAP, located in 
the docket for this rule.
    To demonstrate compliance with the emission limits, the EPA is 
proposing initial and repeat 5-year performance testing for the 
regulated pollutants, continuous parameter monitoring, and daily 
visible emissions (VE) checks. Owners and operators whose clay 
refractory products kilns are equipped with a fabric filter to reduce 
PM (as a surrogate for metal HAP) have the option of demonstrating 
compliance using a bag leak detection system instead of daily VE 
checks.
c. Consideration of Beyond-the-Floor Options
    The EPA also evaluated the beyond-the-floor option of requiring all 
existing sources to meet the proposed new source MACT standards for 
mercury and PM (as a surrogate for total (non-mercury) metal HAP). We 
assume an uncontrolled kiln would need a fabric filter for control of 
PM and an activated carbon injection and fabric filter system for 
control of mercury to meet the new source standards. For the total 
(non-mercury) metal HAP beyond-the-floor option, we estimate the total 
capital cost would be $1.74 million, the annual cost would be $649,000, 
and the control would achieve (non-mercury) metal HAP reductions of 
0.015 tpy, for a cost effectiveness of $42.7 million per ton of (non-
mercury) metal HAP removed. For the mercury beyond-the-floor option, we 
estimate the total capital cost would be $1.84 million, the annual cost 
would be

[[Page 3096]]

$740,000, and the control would achieve mercury reductions of 0.0023 
tpy, for a cost effectiveness of $321 million per ton of mercury 
removed.
    We conclude that the costs of the controls are not reasonable 
relative to the level of emission reduction achieved for either the 
mercury or total (non-mercury) metal HAP beyond-the-floor options. In 
addition, these controls would create additional solid waste, as there 
would be a need to dispose of the collected metal-contaminated dust. 
Therefore, we are not proposing beyond-the-floor limits for mercury or 
total non-mercury metal HAP and are proposing standards based on the 
MACT floor. See the technical memorandum titled Development of Proposed 
Standards and Impacts for the Refractory Products Manufacturing NESHAP, 
located in the docket for this rule, for details regarding the 
derivation of the cost and emission estimates for the beyond-the-floor 
option.
2. Nonclay Refractory Products That Use Organic HAP
    For existing nonclay refractory sources, the 2002 Refractory 
Products Manufacturing NESHAP proposal preamble identifies organic HAP 
as the primary emissions from the manufacture of nonclay products that 
include organic resin binders. The NESHAP requires control of organic 
HAP with a THC limit for these sources. Sources currently employ the 
use of thermal oxidizers, regenerative thermal oxidizers, and catalytic 
oxidizers to meet the THC limit. However, the NESHAP does not require 
sources to use natural gas as fuel for sources in this subcategory 
because metal HAP emissions were determined to be below measurable 
quantities due to the use of purified nonclay raw materials. Available 
HAP data for these sources in the 2017 NEI were found to be outdated 
and not reflective of current operating conditions. The 2017 NEI 
included measurable PM emissions for these existing nonclay refractory 
sources, and the PM would be expected to have trace amounts of metal 
HAP; however, we have no emission stack test data to indicate 
measurable emissions of metal HAP for these existing nonclay refractory 
sources.\23\ Therefore, we are proposing a work practice standard to 
use natural gas as fuel for existing nonclay refractory sources to 
limit metal HAP emissions in lieu of a numerical emissions standard as 
the MACT floor level of control in accordance with CAA section 112(h). 
Because we expect HAP metals to be emitted in unmeasurable quantities 
based on the purified raw materials used and we have no emission stack 
test data to indicate measurable emissions of metal HAP for these 
existing nonclay refractory sources, we could not identify a beyond the 
floor measure that would obtain further emission reductions.
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    \23\ Thus, while we believe that there are metal HAP emissions, 
the lack of data showing measurable emissions leads the EPA to 
conclude that the application of measurement methodology to this 
class of sources is not practicable due to technological and 
economic limitations. See CAA 112(h)(2)(B).
---------------------------------------------------------------------------

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

    As described in section III of this preamble, for the Refractory 
Products Manufacturing source category, we conducted a risk assessment 
for all HAP emitted. We present results of the risk assessment briefly 
below and in more detail in the Refractory Products Risk Assessment 
Report, in the Docket for this action (Docket ID No. EPA-HQ-OAR-2020-
0148).
1. Chronic Inhalation Risk Assessment Results
    Table 1 below provides a summary of the results of the inhalation 
risk assessment for the source category. For more detail about the 
MACT-allowable emission levels, see Appendix 1 to the Refractory 
Products Risk Assessment Report, in the Docket for this action.

                              Table 1--Refractory Products Manufacturing Source Category Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                           Maximum individual     Estimated population      Estimated annual         Maximum chronic         Maximum
                                            cancer risk (in 1     at increased risk of      cancer incidence       noncancer TOSHI \1\   screening acute
                                                million)             cancer >=1-in-1        (cases per year)    ------------------------   noncancer HQ
                                        ------------------------         million        ------------------------                               \2\
            Risk assessment                                     ------------------------                          Based on    Based on  ----------------
                                          Based on    Based on    Based on    Based on    Based on    Based on     actual     allowable
                                           actual     allowable    actual     allowable    actual     allowable   emissions   emissions  Based on actual
                                          emissions   emissions   emissions   emissions   emissions   emissions                             emissions
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Category........................         0.7         0.7           0           0      0.0003      0.0003        0.04        0.04    HQREL = 0.09
Whole Facility.........................         0.7  ..........           0  ..........      0.0004  ..........        0.04  ..........  ...............
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The target organ specific hazard index (TOSHI) is the sum of the chronic noncancer HQs for substances that affect the same target organ or organ
  system.
\2\ The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop HQ values.

    The results of the inhalation risk modeling, as shown above, 
indicate that the maximum individual cancer risk based on actual and 
allowable emissions (lifetime) is 0.7-in-1 million (driven by trace 
amounts of chromium, arsenic, nickel, and cadmium emissions from tunnel 
kilns) and the total estimated annual cancer incidence (national) from 
these facilities based on actual and allowable emission levels is 
0.0003 excess cancer cases per year or one case every 3,333 years. The 
maximum chronic noncancer TOSHI value based on actual and allowable 
emissions is 0.04 (driven by HF from tunnel kilns).
2. Screening Level Acute Risk Assessment Results
    Table 1 of this preamble shows the acute risk results for the 
Refractory Products Manufacturing source category. The screening 
analysis for acute impacts was based on an estimate of acute emissions 
developed for each emissions source using compliance test report data 
and engineering calculations. The maximum screening acute noncancer HQ 
value (off-facility site) is 0.09 (driven by HF). For more detailed 
acute risk screening results, refer to the Refractory Products Risk 
Assessment Report, in the Docket for this action.
3. Multipathway Risk Screening Results
    The emissions data for Refractory Products Manufacturing source 
category indicate that five PB-HAP are emitted by sources within this 
source category: Arsenic, cadmium, POM, mercury (divalent mercury and 
methyl mercury), and lead. The cadmium emissions from these facilities 
did not exceed the Tier 1 multipathway SV of 1 for cancer or noncancer. 
The arsenic, methyl mercury, and POM emissions exceeded the Tier 1 
multipathway SV of 1 for cancer. Therefore, a Tier 2 screening

[[Page 3097]]

assessment was conducted for arsenic, menthyl mercury and POM. 
Emissions of arsenic, POM, and methyl mercury from these facilities did 
not exceed the Tier 2 multipathway SV of 1 for cancer. The Tier 2 
noncancer screening assessment resulted in an SV less than 1 for 
mercury emissions.
    An exceedance of a screening threshold emission rate or SV in any 
of the tiers cannot be equated with a risk value or an HQ (or HI). 
Rather, it represents a high-end estimate of what the risk or hazard 
may be. For example, an SV of 2 for a non-carcinogen can be interpreted 
to mean that we are confident that the HQ would be lower than 2. 
Similarly, a Tier 2 cancer SV of 5 means that we are confident that the 
risk is lower than 5-in-1 million. Our confidence comes from the 
conservative, or health-protective, assumptions encompassed in the 
screening tiers: we choose inputs from the upper end of the range of 
possible values for the influential parameters used in the screening 
tiers, and we assume that the exposed individual exhibits ingestion 
behavior that would lead to a high total exposure. Based upon the 
results of this screening assessment no further screening or site-
specific assessments were conducted for this source category.
    In evaluating the potential for multipathway effects from emissions 
of lead, modeled maximum annual-average lead concentrations were 
compared to the NAAQS for lead (0.15 [micro]g/m3). Results of this 
analysis confirmed that the NAAQS for lead would not be exceeded by any 
facility.
4. Environmental Risk Screening Results
    As described in section III.A of this preamble, we conducted an 
environmental risk screening assessment for the Refractory Products 
Manufacturing source category for the following pollutants: Arsenic, 
cadmium, HCl, HF, lead, mercury (divalent mercury and methyl mercury), 
and POM.
    In the Tier 1 screening analysis for PB-HAP (other than lead, which 
was evaluated differently), arsenic, cadmium, divalent mercury, and POM 
had no Tier 1 exceedances for any ecological benchmark. Methyl mercury 
emissions at one facility had a Tier 1 exceedance for the surface soil 
NOAEL (avian ground insectivores) by a maximum SV of 2. A Tier 2 
screening assessment was performed for methyl mercury. Methyl mercury 
had no Tier 2 exceedances for any ecological benchmark.
    For lead, we did not estimate any exceedances of the secondary lead 
NAAQS.
    For HCl and HF, the average modeled concentration around each 
facility (i.e., the average concentration of all off-site data points 
in the modeling domain) did not exceed any ecological benchmark. In 
addition, each individual modeled concentration of HCl (i.e., each off-
site data point in the modeling domain) was below the ecological 
benchmarks for all facilities. For HF, the maximum facility SV (based 
on the average concentration of all off-site data points over the 
modeling domain) was well below 1 (0.007) and the maximum area that 
exceeded the ecological benchmark was only 0.002 percent of the modeled 
area.
    Based on the results of the environmental risk screening analysis, 
we do not expect an adverse environmental effect as a result of HAP 
emissions from this source category.
5. Facility-Wide Risk Results
    As shown in Table 1 of this document, the maximum facility-wide 
cancer MIR is 0.7-in-1 million, driven by chromium, arsenic, nickel, 
and cadmium emissions from tunnel kilns. The total estimated cancer 
incidence from the whole facility is 0.0004 excess cancer cases per 
year, or one excess case in every 2,500 years. No people were estimated 
to have cancer risks above 1-in-1 million from exposure to HAP emitted 
from both MACT and non-MACT sources at the three facilities in this 
source category. The maximum facility-wide TOSHI for the source 
category is estimated to be 0.04, driven by HF emissions from tunnel 
kilns.
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 Refractory Products 
Manufacturing source category across different demographic groups 
within the populations living near facilities.\24\
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    \24\ 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 the minority 
population is significantly lower within 5 km of the facilities than 
the national percentage (18 percent versus 38 percent). This difference 
is accounted for by smaller population percentages around the 
facilities for all minority demographic groups. Specifically, African 
American (6 percent versus 12 percent nationally), Native American (0.1 
percent versus 0.8 percent nationally), Other and Multiracial (5 
percent versus 7 percent nationally), and Hispanic or Latino (6 percent 
versus 18 percent nationally). In addition, the percentage of the 
population living within 5 km of facilities in the source category is 
lower than the corresponding national percentage for the demographic 
groups, ``Over 25 Without a HS Diploma'' (10 percent versus 14 percent 
nationally) and ``Below the Poverty Level'' (11 percent versus 14 
percent nationally). When examining the risk levels of those exposed to 
emissions from Refractory Products Manufacturing 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 titled Risk and Technology Review--
Analysis of Demographic Factors for Populations Living Near Refractory 
Products Manufacturing Source Category Operations, September 2020 
(hereafter referred to as the Refractory Products Manufacturing 
Demographic Analysis Report), in the docket for this action.

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

1. Risk Acceptability
    As noted in section III.A of this preamble, we weigh all health 
risk factors in our risk acceptability determination, including the 
cancer MIR, the number of persons in various cancer and noncancer risk 
ranges, cancer incidence, the maximum noncancer TOSHI, the maximum 
acute noncancer HQ, the extent of noncancer risks, the distribution of 
cancer and noncancer risks in the exposed population, and risk 
estimation uncertainties (54 FR 38044, September 14, 1989).
    For the Refractory Products Manufacturing source category, the risk 
analysis indicates that cancer risk due to actual emissions or 
allowable emissions is 0.7-in-1 million. The risks are considerably 
less than 100-in-1 million, which is the presumptive upper limit of 
acceptable risk. The risk analysis also

[[Page 3098]]

shows we did not identify a potential for adverse chronic noncancer 
health effects. The acute noncancer risks based on actual emissions are 
low at an HQ of less than 1 (based on the REL) for HF. Therefore, we 
find there is little potential concern of acute noncancer health 
impacts from actual emissions. In addition, the risk assessment 
indicates no significant potential for multipathway health effects.
    Considering all of the health risk information and factors 
discussed above, including the uncertainties discussed in section 
III.C.7 of this preamble, we propose to find that the risks from the 
Refractory Products Manufacturing source category are acceptable.
3. Ample Margin of Safety Analysis
    We are proposing that the risks from the Refractory Products 
Manufacturing source category are acceptable. There are no individuals 
in the exposed population with lifetime cancer risks above 1-in-1 
million as a result of actual or allowable emissions from this 
category. In addition, in our risk analysis we did not identify a 
potential for adverse chronic noncancer, acute noncancer, or 
multipathway health effects. Therefore, we are proposing that the 
current standards provide an ample margin of safety to protect public 
health.
4. Adverse Environmental Effect
    The emissions data for the Refractory Products Manufacturing source 
category indicate that the following environmental HAP are emitted by 
this category: Arsenic, cadmium, HCl, HF, lead, mercury (divalent 
mercury and methyl mercury), and POM. The screening-level evaluation of 
the potential for adverse environmental effects associated with 
emissions of these environmental HAP from the Refractory Products 
Manufacturing source category indicated that there are no exceedances 
of Tier 2 SVs for PB-HAP, no exceedances of the average modeled 
concentration around each facility (i.e., the average concentration of 
all off-site data points in the modeling domain) for acid gases, and 
for lead we did not estimate any exceedances of the secondary lead 
NAAQS. In addition, we are unaware of any adverse environmental effects 
caused by HAP emitted by this source category. Therefore, we do not 
expect there to be an adverse environmental effect as a result of HAP 
emissions from this source category, and taking into consideration 
costs, energy, safety, and other relevant factors, we are proposing 
that it is not necessary to set a more stringent standard to prevent an 
adverse environmental effect.

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

    As described in section III.B of this preamble, our technology 
review focused on identifying developments in practices, processes, and 
control technologies for the Refractory Products source category. We 
reviewed various information sources regarding emission sources that 
are currently regulated by the Refractory Products Manufacturing NESHAP 
to support the technology review. The information sources included the 
following: The RBLC; state regulations; facility operating permits; 
regulatory actions, including technology reviews promulgated for other 
similar NESHAP subsequent to the Surface Coating of Metal Cans NESHAP; 
and discussions with individual refractory product manufacturing 
facilities.
    A brief discussion of our review of these various information 
sources follows. Based on our review of facility operating permits and 
discussions with individual refractory product manufacturing 
facilities, we identified an advance in practice that we are proposing 
under CAA section 112(d)(6) in this action.
    Our search of the RBLC database for improvements in refractory 
products manufacturing technologies did not identify any new 
developments in practices, processes, or control technologies for the 
Refractory Products Manufacturing source category under CAA section 
112(d)(6).
    We also reviewed requirements for other similar source categories. 
During development of the Refractory Products Manufacturing NESHAP, we 
identified two other source categories that operate kilns that are 
similar in design and operation to kilns that manufacture clay 
refractory products: The Clay Ceramics Manufacturing Industry and the 
Brick and Structural Clay Products Manufacturing Industry. Since the 
promulgation of the Refractory Products Manufacturing NESHAP, the 
NESHAP for these two other source categories were vacated, and new 
NESHAP for Brick and Structural Clay Products Manufacturing Industry 
and NESHAP for Clay Ceramics Manufacturing Industry were promulgated on 
October 26, 2015 (80 FR 65470). However, the control devices have not 
changed since the promulgation of the Refractory Products Manufacturing 
NESHAP. Therefore, no developments in practices, processes, and control 
technologies were identified in the NESHAP for Brick and Structural 
Clay Products Manufacturing Industry and NESHAP for Clay Ceramics 
Manufacturing Industry that were not considered during the Refractory 
Products Manufacturing NESHAP development.
    We also contacted representatives for the three major source 
facilities subject to the Refractory Products Manufacturing NESHAP and 
the industry trade association, The Refractories Institute, and asked 
them to identify facility-specific developments in practices, 
processes, and control technologies. Two of the three facilities 
indicated they had not made changes in raw materials or manufacturing 
practices and processes because such changes would detrimentally affect 
their products. One facility had installed a wet scrubber to control 
opacity/particulate matter (a surrogate for metal HAP) emitted by its 
tunnel kilns used to manufacture both clay and nonclay refractory 
products. Since wet scrubbers were previously considered during the 
Refractory Products Manufacturing NESHAP development, we did not 
consider this to be a development in control technology.
    We also conducted a review of the state operating permits for the 
three major source facilities that are subject to the Refractory 
Products Manufacturing NESHAP and three synthetic area source 
refractory facilities to determine whether any are using technologies 
that exceed the MACT level of control or are using technologies that 
were not considered during the development of the original NESHAP. We 
found the HAP control devices described in the permits were considered 
and included in the 2003 Refractory Products Manufacturing NESHAP for 
the relevant refractory products. Therefore, the permit review did not 
identify any new developments in processes or control technologies for 
the refractory manufacturing source category under CAA section 
112(d)(6).
    Based on our review of facility operating permits and discussions 
with individual refractory product manufacturing facilities, we 
identified an advance in practice that we are proposing in this action. 
The current NESHAP has a work practice standard that applies during 
periods of scheduled maintenance of emission controls for continuous 
kilns during bypass periods. We are proposing to limit the provision to 
THC emission controls and add additional requirements to reflect the 
best practices for one facility as part of the technology review 
required by CAA section 112(d)(6). In addition to the best practices, 
we are proposing an additional reporting requirement. We

[[Page 3099]]

are aware of only one major source facility that uses this provision 
and will be affected by these proposed requirements.
    To comply with current NESHAP work practice standard, the owner or 
operator must request approval from the Administrator to bypass the 
control device, minimize THC emissions during the period when the kiln 
is operating and the control device is out of service, and minimize the 
amount of time that the kiln is operating and the control device is out 
of service. Approval from the Administrator must be requested in 
advance for each scheduled maintenance event of the control device if 
the bypass of the control device is required to conduct the 
maintenance. The procedures for minimizing the THC emissions during the 
time the control device is out of service and the amount of time the 
control device is out of service for maintenance must be included in 
the facility's OM&M plan, and records of the maintenance performed are 
also required.
    Consistent with the demonstrated best practices for one facility, 
we are proposing a revision to the existing requirements to limit the 
number of hours bypass of the emission controls can occur to no more 
than 750 hours per kiln per year. If the control being bypassed is for 
THC control, the facility is also required to manufacture products with 
lower HAP binder and limit production to no more than five cars with 
higher THC binder levels during these periods, Therefore, we are also 
proposing to require sources to schedule the manufacture of product 
with binder percentages at the lower end of the range produced (i.e., 
below the typical average of product binder content) and the number of 
kiln cars with products for which the mass fraction of organic HAP in 
the resins, binders, and additives greater than the average must not 
exceed five for the year on a 12-month rolling basis, consistent with 
the best practices of the facility. Based on 2017 raw material and 
production data provided by the facility, we estimate that if the 
regenerative thermal oxidizer was offline for all 750 hours allowed by 
the permit for maintenance, the HAP emissions during that 750 hours 
would be about 61 pounds per year. This estimate is considered 
conservative because it does not take into account any HAP emission 
reductions that were achieved by implementing the best practices 
described in this paragraph for periods when the control device is 
offline (scheduling products with low HAP binder and limiting higher 
THC binder levels to five cars).
    Finally, we are also proposing to add new reporting requirements 
for these periods. We are proposing to require reporting of the THC 
emissions and other information for control device maintenance and 
bypass periods in semi-annual compliance reports (in addition to the 
current NESHAP provision to document the planned maintenance procedures 
in the OM&M plan and to maintain records of continuous kiln 
maintenance). Reporting of this information in the semi-annual 
compliance reports will help to ensure compliance with the revised 
requirements that we are proposing.
    As part of the technology review, we also identified previously 
unregulated HAP, and are proposing new standards under CAA sections 
112(d)(2) and (3), as described in section IV.A, above. Additional 
information supporting the revised standard is provided in the 
memorandum titled Technology Review for the Refractory Products 
Manufacturing NESHAP, available in the docket for this action.

E. What other actions are we proposing?

    In addition to the proposed actions described above, we are 
proposing additional revisions to the NESHAP. We are proposing 
revisions to the SSM provisions of the MACT rule in order to ensure 
that they are consistent with the decision in Sierra Club v. EPA, 551 
F. 3d 1019 (D.C. Cir. 2008), in which the court vacated two provisions 
that exempted sources from the requirement to comply with otherwise 
applicable CAA section 112(d) emission standards during periods of SSM. 
We also are proposing various other changes to require electronic 
submittal of notification of compliance status (NOCS) reports, 
performance test and performance evaluation reports for refractory 
products manufacturing facilities, new test methods and incorporation 
by reference (IBR) of alternative test methods, and making technical 
and editorial revisions. Our analyses and proposed changes related to 
these issues are discussed in the sections below.
1. SSM
a. Proposed Elimination of the SSM Exemption
    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, 
which appears at 40 CFR 63.9792(a)(1). 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 11 of 40 CFR part 63, 
subpart SSSSS (Applicability of General Provisions to Subpart SSSSS, 
hereafter referred to as the ``General Provisions table to subpart 
SSSSS''). For example, we are proposing to eliminate the incorporation 
of the General Provisions' requirement that the source develop an SSM 
plan. Further, we 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 
seeking comment on the specific proposed deletions and revisions and 
also whether additional provisions should be revised to achieve the 
stated goal.
    In proposing these rule amendments, the EPA has taken into account 
startup and shutdown periods and, for the reasons explained below, is 
not proposing alternate standards for those periods. Nonclay refractory 
sources employ the use of continuous and periodic kilns that use air 
pollution control devices, including thermal oxidizers, regenerative 
thermal oxidizers, and catalytic oxidizers, to meet the THC limit in 
the rule. Facility representatives for these sources indicated that 
startups and shutdowns of the kilns and air pollution control devices 
are part of normal operations and they experience no difficulties in 
meeting the existing THC emission limit during these periods. 
Therefore, alternative standards are not needed.
    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, process, 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

[[Page 3100]]

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 operations 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 standards would be difficult, if not 
impossible, given the myriad different types of malfunctions that can 
occur across all sources in the category and given the difficulties 
associated with predicting or accounting for the frequency, degree, and 
duration of various malfunctions that might occur. 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 RTR, the EPA established a 
work practice standard for unique types of malfunctions that result in 
releases from pressure relief devices or emergency flaring events 
because we had information to determine that such work practices 
reflected the level of control that applies to the best performing 
sources (80 FR 75178, 75211 through 75214, December 1, 2015). The EPA 
will consider whether circumstances warrant setting 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(d) standards as a result of a malfunction event, the EPA 
will 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 will also consider whether the source's failure to comply with 
the CAA section 112(d) standard was, in fact, sudden, infrequent, not 
reasonably preventable, and was not instead caused, in part, by poor 
maintenance or careless operation. 40 CFR 63.2 (Definition of 
malfunction).
    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).
b. 40 CFR 63.9792(b) General Duty
    We are proposing to revise the General Provisions table to subpart 
SSSSS (Table 11) entry for 40 CFR 63.6(e)(1)(i) by changing the ``yes'' 
in column 4 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 63.9792(b) 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

[[Page 3101]]

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 for 40 CFR 
63.9792(b) does not include that language from 40 CFR 63.6(e)(1)(i).
    We are also proposing to revise the General Provisions table to 
subpart SSSSS (Table 11) entry for 40 CFR 63.6(e)(1)(ii) by changing 
the ``yes'' in column 4 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 63.9792(b).
c. SSM Plan
    We are proposing to revise the General Provisions table to subpart 
SSSSS (Table 11) entry for 40 CFR 63.6(e)(3) by changing the ``yes'' in 
column 4 to a ``no.'' Generally, these paragraphs require development 
of an SSM plan and specify SSM recordkeeping and reporting requirements 
related to the SSM plan. We are also proposing to remove from 40 CFR 
part 63, subpart SSSSS, the current provisions requiring the SSM plan 
at 40 CFR 63.9792(c). 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.
d. Compliance With Standards
    We are proposing to revise the General Provisions table to subpart 
SSSSS (Table 11) entry for 40 CFR 63.6(f)(1) by changing the ``yes'' in 
column 4 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 the standards in this rule to apply at all times.
e. 40 CFR 63.9800 Performance Testing
    We are proposing to revise the General Provisions table to subpart 
SSSSS (Table 11) entry for 40 CFR 63.7(e)(1) by changing the entry in 
column 4 to a ``no.'' Section 63.7(e)(1) describes performance testing 
requirements. The EPA is instead proposing to add a performance testing 
requirement at 40 CFR 63.9800(d). The performance testing requirements 
we are proposing to add differ from the General Provisions performance 
testing provisions in several respects. The regulatory text does not 
include the language in 40 CFR 63.7(e)(1) that restated the SSM 
exemption and language that precluded startup and shutdown periods from 
being considered ``representative'' for purposes of performance 
testing. The proposed performance testing provisions will also not 
allow performance testing during startup or shutdown. As in 40 CFR 
63.7(e)(1), performance tests conducted under this subpart should not 
be conducted during malfunctions because conditions during malfunctions 
are often not representative of normal operating conditions. Section 
63.7(e) requires that the owner or operator maintain records of the 
process information necessary to document operating conditions during 
the test and include in such records an explanation to support that 
such conditions represent normal operation. The EPA is proposing to add 
language clarifying that the owner or operator must make such records 
available to the Administrator.
f. Monitoring
    We are proposing to revise the General Provisions table to subpart 
SSSSS (Table 11) entry for 40 CFR 63.8(c)(1) by changing the ``yes'' in 
column 4 to a ``no.'' The cross-references to the general duty and SSM 
plan requirements in 40 CFR 63.8(c)(1) 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)) and that set out the requirements 
of a quality control program for monitoring equipment (40 CFR 63.8(d)). 
Further, we are proposing to revise 40 CFR 63.9804(a)(13) and 
63.9808(b) to add requirements to maintain the monitoring equipment at 
all times in accordance with 40 CFR 63.9792(b) and keep the parts 
readily available for routine repairs of the monitoring equipment, 
consistent with the requirements in 40 CFR 63.8(c)(1)(ii).
g. 40 CFR 63.9816 Recordkeeping
    We are proposing to revise the General Provisions table to subpart 
SSSSS (Table 11) entry for 40 CFR 63.10(b)(2)(i) by changing the 
``yes'' in column 4 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 to subpart 
SSSSS (Table 11) entry for 40 CFR 63.10(b)(2)(ii) by changing the 
``yes'' in column 4 to a ``no.'' Section 63.10(b)(2)(ii) describes the 
recordkeeping requirements during a malfunction, requiring a record of 
``the occurrence and duration of each malfunction.'' A similar record 
is already required in 40 CFR 63.9816(c)(5), which requires a record of 
``the date, time, and duration of each deviation,'' which the EPA is 
retaining. The regulatory text in 40 CFR 63.9816(c)(5) differs from the 
General Provisions 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; whereas 40 CFR 63.9816(c)(5) applies 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.'' 
For this reason, the EPA is proposing to add to 40 CFR 63.9816(c)(5) a 
requirement that sources also 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 emission limit 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 (e.g., process throughput, 
rate, operating temperature, organic HAP content, and control device 
efficiencies). 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 to subpart 
SSSSS (Table 11) entry for 40 CFR

[[Page 3102]]

63.10(b)(2)(iv) and (v) by changing the ``yes'' in column 4 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 in 40 CFR 63.10(b)(2)(iv) 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 63.9816(c)(5). When applicable, 
the provision in 40 CFR 63.10(b)(2)(v) 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.
    We are proposing to revise the General Provisions table to subpart 
SSSSS (Table 11) entry for 40 CFR 63.10(b)(2)(vi) by changing the 
``yes'' in column 4 to a ``no.'' The provision requires sources to 
maintain records during continuous monitoring system (CMS) 
malfunctions. Section 63.9816(c)(5) covers records of periods of 
deviation from the standard, including instances where a CMS is 
inoperative or out-of-control.
    We are proposing to revise the General Provisions table to subpart 
SSSSS (Table 11) entry for 40 CFR 63.10(c)(15) by changing the ``yes'' 
in column 4 to a ``no.'' When applicable, the provision allows an owner 
or operator to use the affected source's SSM plan or records kept to 
satisfy the recordkeeping requirements of the SSM plan, specified in 40 
CFR 63.6(e), to also satisfy the requirements of 40 CFR 63.10(c)(10) 
through (12). The EPA is proposing to eliminate this requirement 
because SSM plans would no longer be required, and, therefore, 40 CFR 
63.10(c)(15) no longer serves any useful purpose for affected units.
    We are proposing to remove the requirement in 40 CFR 63.9816(a)(2) 
that deviation records specify whether deviations from a standard 
occurred during a period of SSM. This revision is being proposed due to 
the proposed removal of the SSM exemption and because, as discussed 
above in this section, we are proposing that deviation records must 
specify the cause of each deviation, which could include a malfunction 
period as a cause. We are also proposing to remove the requirement to 
report the SSM records in 40 CFR 63.6(e)(3)(iii) through (v) by 
deleting 40 CFR 63.9816(a)(2).
h. 40 CFR 63.9814 Reporting
    We are proposing to revise the General Provisions table to subpart 
SSSSS (Table 11) entry for 40 CFR 63.10(d)(5) by changing the ``yes'' 
in column 4 to a ``no.'' Section 63.10(d)(5) describes the reporting 
requirements for SSM. To replace the General Provisions reporting 
requirement, the EPA is proposing to remove the immediate SSM report 
from Table 10 referenced at 40 CFR 63.9814(a) and add reporting 
requirements to 40 CFR 63.9814(d) and (e). The replacement language 
differs from the General Provisions requirement in that it eliminates 
the SSM report 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. For deviations from 
an applicable emission limitation that occur at an affected source 
where a CPMS is not used to demonstrate compliance, 40 CFR 63.9814(d) 
already requires that the semi-annual compliance report must contain 
the number, duration, and the cause of such events (including unknown 
cause, if applicable). We are proposing that the report also include 
the date and time of each deviation, a list of the affected source or 
equipment, an estimate of the quantity of each regulated pollutant 
emitted over any emission limit for which the source failed to meet the 
standard, and a description of the method used to estimate the 
emissions. Similarly, for deviations from an applicable emission 
limitation that occur at an affected source where a CPMS is used to 
demonstrate compliance, we are retaining the current requirements in 40 
CFR 63.9814(e) to report the date, time, and cause of each deviation. 
We are proposing that the report must also contain the number and 
duration of deviations, a list of the affected sources 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.
    Regarding the proposed new requirement discussed above to estimate 
the quantity of each regulated pollutant emitted over any emission 
limit 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 (e.g., process throughput, rate, 
operating temperature, organic HAP content, and control device 
efficiencies). The EPA is proposing this requirement to ensure that the 
EPA has 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 plans would no longer be required. The proposed amendments, 
therefore, eliminate the requirement in Table 10 to 40 CFR part 63, 
subpart SSSSS to report whether the source deviated from its SSM plan, 
including required actions to communicate with the Administrator, and 
the cross-reference to 40 CFR 63.10(d)(5)(ii) 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.
    Section 63.10(d)(5)(ii) describes an immediate report for SSM when 
a source failed to meet an applicable standard but did not follow the 
SSM plan. We will no longer require owners and operators to report when 
actions taken during an SSM event were not consistent with an SSM plan, 
because plans would no longer be required.
    We are proposing to remove the requirement in 40 CFR 63.9814(e)(5) 
that deviation reports must specify whether deviation from an operating 
limit occurred during a period of SSM. We are also proposing to remove 
the requirements in 40 CFR 63.9814(e)(8) to break down the total 
duration of deviations into the startup and shutdown categories. As 
discussed above in this section, we are proposing to require reporting 
of the cause of each deviation. Further, the startup and shutdown 
categories no longer apply because these periods are proposed to be 
considered normal operation.
2. Electronic Reporting Requirements
    The EPA is proposing that owners and operators of refractory 
products manufacturing facilities submit electronic copies of NOCS 
required by 40 CFR 63.7(b) and (c), 40 CFR 63.8(f)(4), and 40 CFR 63.9 
(b) through (e) and (h), and 40 CFR 63.9812, and performance test 
results and performance evaluation results required

[[Page 3103]]

by 40 CFR 63.9(h) and 40 CFR 63.9800, and 40 CFR 63.9814 through the 
EPA's Central Data Exchange (CDX) using the Compliance and Emissions 
Data Reporting Interface (CEDRI). A description of the electronic data 
submission process is provided in the memorandum, Electronic Reporting 
Requirements for New Source Performance Standards (NSPS) and National 
Emission Standards for Hazardous Air Pollutants (NESHAP) Rules, 
available in the docket for this action. The proposal requires that all 
NOCS be submitted as portable document format (PDF) files and uploaded 
to CEDRI. For performance test and performance evaluation results the 
proposal requires test results that use test methods supported by the 
EPA's Electronic Reporting Tool (ERT) listed on the ERT website \25\ at 
the time of the test be submitted in the format generated through the 
use of the ERT or an electronic file consistent with the xml schema on 
the ERT website. Performance test results using test methods that are 
not supported by the ERT at the time of the test are required to 
submitted as a PDF file using the attachment module of the ERT.
---------------------------------------------------------------------------

    \25\ https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert.
---------------------------------------------------------------------------

    Additionally, the EPA has identified two broad circumstances in 
which electronic reporting extensions may be provided. These 
circumstances are (1) outages of the EPA's CDX or CEDRI that preclude 
an owner or operator from accessing the system and submitting required 
reports and (2) force majeure events, which are defined as events that 
will be or have been caused by circumstances beyond the control of the 
affected facility, its contractors, or any entity controlled by the 
affected facility that prevent an owner or operator from complying with 
the requirement to submit a report electronically. Examples of force 
majeure events are acts of nature, acts of war or terrorism, or 
equipment failure or safety hazards beyond the control of the facility. 
The EPA is providing these potential extensions to protect owners and 
operators from noncompliance in cases where they cannot successfully 
submit a report by the reporting deadline for reasons outside of their 
control. In both circumstances, the decision to accept the claim of 
needing additional time to report is within the discretion of the 
Administrator, and reporting should occur as soon as possible.
    The electronic submittal of the reports addressed in this proposed 
rulemaking will increase the usefulness of the data contained in those 
reports, is in keeping with current trends in data availability and 
transparency, will further assist in the protection of public health 
and the environment, will improve compliance by facilitating the 
ability of regulated facilities to demonstrate compliance with 
requirements and by facilitating the ability of delegated state, local, 
tribal, and territorial air agencies and the EPA to assess and 
determine compliance, and will ultimately reduce burden on regulated 
facilities, delegated air agencies, and the EPA. Electronic reporting 
also eliminates paper-based, manual processes, thereby saving time and 
resources, simplifying data entry, eliminating redundancies, minimizing 
data reporting errors, and providing data quickly and accurately to the 
affected facilities, air agencies, the EPA, and the public. Moreover, 
electronic reporting is consistent with the EPA's plan \26\ to 
implement Executive Order 13563 and is in keeping with the EPA's 
Agency-wide policy \27\ developed in response to the White House's 
Digital Government Strategy.\28\ For more information on the benefits 
of electronic reporting, see the memorandum, Electronic Reporting 
Requirements for New Source Performance Standards (NSPS) and National 
Emission Standards for Hazardous Air Pollutants (NESHAP) Rules, 
referenced earlier in this section.
---------------------------------------------------------------------------

    \26\ EPA's Final Plan for Periodic Retrospective Reviews, August 
2011. Available at: https://www.regulations.gov/document?D=EPA-HQ-OA-2011-0156-0154.
    \27\ E-Reporting Policy Statement for EPA Regulations, September 
2013. Available at: https://www.epa.gov/sites/production/files/2016-03/documents/epa-ereporting-policy-statement-2013-09-30.pdf.
    \28\ Digital Government: Building a 21st Century Platform to 
Better Serve the American People, May 2012. Available at: https://obamawhitehouse.archives.gov/sites/default/files/omb/egov/digital-government/digital-government.html.
---------------------------------------------------------------------------

3. Incorporation by Reference Under 1 CFR Part 51
    The EPA is proposing regulatory text that includes IBR. In 
accordance with requirements of 1 CFR 51.5, the EPA is proposing to 
incorporate by reference the following documents described in the 
amendments to 40 CFR 63.14:
     ANSI/ASME PTC 19.10-1981, ``Flue and Exhaust Gas Analyses 
[Part 10, Instruments and Apparatus],'' issued August 31, 1981, IBR 
proposed for Table 4 to 40 CFR part 63, subpart SSSSS. This document 
specifies methods, apparatus, and calculations which are used to 
determine quantitatively, the gaseous constituents of the exhausts 
including oxygen and carbon dioxide resulting from station combustions 
sources.
     ASTM D6348-12e1, ``Standard Test Method for Determination 
of Gaseous Compounds by Extractive Direct Interface Fourier Transform 
Infrared (FTIR) Spectroscopy,'' Approved February 1, 2012, IBR proposed 
for Table 4 to 40 CFR part 63, subpart SSSSS.
     ASTM D6784-16, ``Standard Test Method for Elemental, 
Oxidized, Particle-Bound and Total Mercury in Flue Gas Generated from 
Coal-Fired Stationary Sources (Ontario Hydro Method),'' (Approved March 
1, 2016), IBR proposed for Table 4 to 40 CFR part 63, subpart SSSSS.
     EPA-454/R-98-015, Office of Air Quality Planning and 
Standards (OAQPS), ``Fabric Filter Bag Leak Detection Guidance,'' 
September 1997, IBR proposed for 40 CFR 63.9804(f). This document 
provides guidance on the use of triboelectric monitors as fabric filter 
bag leak detectors. The document includes fabric filter and monitoring 
system descriptions; guidance on monitor selection, installation, 
setup, adjustment, and operation; and quality assurance procedures.
    The EPA has made, and will continue to make, the EPA document 
generally available electronically through https://www.regulations.gov/ 
and/or in hard copy at the appropriate EPA office (see the ADDRESSES 
section of this preamble for more information). The ANSI/ASME document 
is available from the American Society of Mechanical Engineers (ASME) 
at http://www.asme.org; by mail at Three Park Avenue, New York, NY 
10016-5990; or by telephone at (800) 843-2763. The ASTM methods are 
available from ASTM International at http://www.astm.org; by mail at 
100 Barr Harbor Drive, Post Office Box C700, West Conshohocken, PA 
19428-2959; or by telephone at (610) 832-9585.
4. Technical and Editorial Changes
    The following lists additional proposed changes that address 
technical and editorial corrections:
     Revise 40 CFR 63.9824 and Table 4 to subpart SSSSS of part 
63 to clarify the location in 40 CFR part 60 of applicable EPA test 
methods; and
     Revise 40 CFR 63.9814 and 40 CFR 63.9816 to include the 
requirements to record and report information on failures to meet the 
applicable standard.

F. What compliance dates are we proposing?

    We are proposing that affected sources that commence construction 
or reconstruction after January 14, 2021, must comply with all 
requirements of

[[Page 3104]]

the subpart, including the amendments being proposed, no later than the 
effective date of the final rule or upon startup, whichever is later. 
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).
    We are proposing that affected sources that commence construction 
or reconstruction on or before January 14, 2021, must comply with the 
all requirements of the subpart, including the amendments being 
proposed, no later than the dates described below. We are also 
proposing that existing nonclay affected sources must comply with the 
requirement to use natural gas as fuel, or an equivalent fuel, as the 
kiln fuel (except during periods of natural gas curtailment or supply 
interruption) immediately upon the effective date of the final rule.
    Also, we are proposing that existing affected sources must comply 
with the following two amendments no later than 181 days after the 
effective date of the final rule (i.e., 181 days after the date of 
publication of the final rule in the Federal Register). First, for 
existing affected sources, we are proposing a requirement that 
notifications, performance test results, and performance evaluation 
results be electronically submitted. Second, for existing affected 
sources with continuous kilns using THC emission control devices, we 
are proposing improvements to the existing work practice standard as a 
result of the CAA section 112(d)(6) technology review i.e., limit the 
number of hours for bypass of the control device to conduct scheduled 
maintenance to 750 hours per year per kiln, schedule the manufacture of 
product with binder percentages at the lower end of the range during 
periods of control device bypass, and report THC emissions in the semi-
annual compliance report. Existing affected facilities would have to 
continue to meet the current requirements of 40 CFR part 63, subpart 
SSSSS, until the applicable compliance date of the amended rule (i.e., 
181 days after the date of publication of the final rule in the Federal 
Register).
    Finally, we are proposing that affected clay refractory product 
sources that commenced construction or reconstruction on or before 
January 14, 2021 must meet new limits for PM/metal HAP and mercury no 
later than 1 year after the effective date of the final rule. The EPA 
determined that a 1-year compliance date allows sufficient time for 
notification and testing to demonstrate initial compliance with the new 
PM/metal HAP and mercury limits.
    We are proposing the immediate compliance date for the removal of 
the SSM exemptions in 40 CFR 63.6(f)(1) in accordance with the SSM 
court decision. For other SSM changes, excluding the revised 
requirements for the SSM described above (40 CFR 63.6(f)(1)), our 
experience with similar industries further shows that this sort of 
regulated facility generally requires a time period of 181 days to read 
and understand the amended rule requirements; make any necessary 
adjustments; to read and understand the rule and adjust computer 
systems, evaluate whether changes are needed, and to update their OM&M 
plan to reflect the revised requirements.
    We also determined that an immediate compliance date is practicable 
for the natural gas requirement and is based on current practices and 
other information provided by the facilities.
    We are proposing the 181-day compliance date for electronic 
reporting and the scheduled maintenance work practice to require 
facilities to implement these changes as expeditiously as practicable. 
For electronic reporting, our experience with similar industries that 
are required to convert reporting mechanisms to install necessary 
hardware and software, become familiar with the process of submitting 
performance test results electronically through the EPA's CEDRI, test 
these new electronic submission capabilities, and reliably employ 
electronic reporting shows that a time period of a minimum of 90 days, 
and, more typically, 180 days, is generally necessary to successfully 
accomplish these revisions. For the scheduled maintenance work 
practice, we expect facilities would also need this time to seek 
approval from the Administrator before taking the control device on the 
affected kiln out of service for scheduled maintenance and update their 
operation, maintenance, and monitoring plan to reflect the revised 
requirements.
    For the new PM/metal HAP and mercury requirements, we determined 
the 1-year compliance date would provide existing clay sources with 
sufficient time to plan and schedule facility resources to meet the 
notification and compliance demonstration testing requirements 
associated with the new limits.
    We solicit comment on these proposed compliance periods, 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 any of the 
revised requirements. We note that information provided may result in 
changes to the proposed compliance dates.

V. Summary of Cost, Environmental, and Economic Impacts

A. What are the affected sources?

    Currently, three major sources subject to the Refractory Products 
Manufacturing NESHAP are operating in the United States. The NESHAP 
applies to each new, reconstructed, and existing affected source 
located at a refractory products manufacturing facility that is a major 
source of HAP emissions, is located at a major source of HAP emissions, 
or is part of a major source of HAP emissions. A refractory products 
manufacturing facility is a plant site that manufactures refractory 
products, such as refractory bricks, refractory shapes, monolithics, 
kiln furniture, crucibles, and other materials used for lining furnaces 
and other high temperature process units. Refractory products 
manufacturing facilities typically process raw material by crushing, 
grinding, and screening; mixing the processed raw materials with 
binders and other additives; forming the refractory mix into shapes; 
and drying and firing the shapes. The NESHAP lists the affected sources 
for four subcategories across the industry as the shape dryers, curing 
ovens, and kilns that are used to manufacture refractory products that 
use organic HAP; shape preheaters, pitch working tanks, defumers, and 
coking ovens that are used to produce pitch-impregnated refractory 
products; kilns that are used to manufacture chromium refractory 
products; and kilns that are used to manufacture clay refractory 
products. The three major sources currently operating in the U.S. can 
be grouped into two of the subcategories and use curing ovens and kilns 
that are used to manufacture nonclay refractory products that use 
organic HAP and kilns that are used to manufacture clay refractory 
products.

B. What are the air quality impacts?

    At the current level of control, the estimated emissions of HAP 
from the Refractory Products Manufacturing source category are 
approximately 40 tpy. The proposed amendments require that all three 
major sources in the Refractory Products Manufacturing source category 
comply with the relevant emission standards at all times,

[[Page 3105]]

including periods of SSM. The proposed amendments also limit the number 
of hours a continuous kiln control device can be bypassed during 
scheduled maintenance and require minimizing emissions of THC during 
bypass periods. We were unable to quantify the emissions that occur 
during periods of SSM or the specific emissions reductions that would 
occur as a result of this action. However, eliminating the SSM 
exemption has the potential to reduce emissions by requiring facilities 
to meet the applicable standard during SSM periods. Requiring the use 
of natural gas as kiln fuel also ensures a reduction in metal HAP 
emissions from combustion of coal, fuel oil, or waste-derived fuels.
    Indirect or secondary air emissions impacts are impacts that would 
result from the increased electricity usage associated with the 
operation of control devices (e.g., increased secondary emissions of 
criteria pollutants from power plants). Energy impacts consist of the 
electricity and steam needed to operate control devices and other 
equipment. The proposed amendments would have no effect on the energy 
needs of the affected facilities in either of the two source categories 
and would, therefore, have no indirect or secondary air emissions 
impacts.

C. What are the cost impacts?

    We estimate that each facility in this source category will 
experience costs as a result of these proposed amendments. Estimates 
for reporting and recordkeeping costs for each facility are associated 
with the electronic reporting requirements, elimination of the SSM 
exemption, and scheduled maintenance of continuous kiln control 
devices. The costs associated with the electronic reporting 
requirements are attributed to submittal of notifications and semi-
annual compliance reports using CEDRI and include time for becoming 
familiar with CEDRI. The costs associated with the revised SSM 
requirements were estimated for re-evaluating previously developed SSM 
record systems. The costs associated with recordkeeping to document the 
frequency and duration of scheduled maintenance of control devices for 
continuous kilns were also estimated. The recordkeeping and reporting 
costs are presented in section VIII.C of this preamble.
    We also estimated the costs associated with the proposed new 
compliance testing requirements for the clay refractory sources in this 
action. Two of the major source refractories manufacture clay 
refractory and are required to conduct periodic compliance testing for 
PM/metal HAP and mercury once every 5 years. One clay refractory source 
has two continuous kilns and the other has two continuous kilns and 
three batch kilns. The costs associated with conducting the combined 
PM/metal HAP and mercury test for each continuous kiln stack is 
estimated to be about $23,600. The costs associated with conducting the 
combined PM/metal HAP and mercury test for each batch kiln stack is 
estimated to be about $31,800. We also assumed that tests for 
additional stacks at the same facility would be conducted in the same 
trip, so the additional cost is less due to reduced travel costs. The 
total costs for the two facilities to test the seven kilns in a single 
year would be $115,300. In addition to the testing costs, each facility 
performing the testing will have an additional $6,800 in reporting 
costs per facility in the year in which the test occurs.
    For kilns that meet the limits without any controls, owners or 
operators are required to conduct VE monitoring to demonstrate 
compliance. One of the continuous kilns is controlled with a wet 
scrubber, but the other six kilns are expected to need to conduct VE 
monitoring. We estimate that the monitoring will cost $3,740 per year 
per stack, for a total of $22,400 per year.
    For further information on the potential testing and monitoring 
costs, see the memorandum titled Development of Proposed Standards and 
Impacts for the Refractory Products Manufacturing NESHAP, located in 
the docket for this action.

D. What are the economic impacts?

    The economic impact analysis is designed to inform decision makers 
about the potential economic consequences of the compliance costs 
outlined in section V.C of this preamble. To assess the maximum 
potential impact, the largest cost expected to be experienced in any 
one year is compared to the total sales for the ultimate owner of the 
affected facilities to estimate the total burden for each owner. For 
these proposed amendments, the total cost of testing, monitoring, and 
recordkeeping and reporting is estimated to be $158,140. The total 
annual costs associated with the requirements range from 0.00008 to 
0.18 percent of annual sales revenue per ultimate owner. These costs 
are not expected to result in a significant market impact, regardless 
of whether they are passed on to customers or absorbed by the firms.
    The EPA also prepared a small business screening assessment to 
determine whether any of the identified affected facilities are small 
entities, as defined by the U.S. Small Business Administration. One of 
the facilities affected by these amendments is a small entity. However, 
the annual cost associated with the requirements is 0.18 percent of 
annual sales revenue for the owner of that facility. Therefore, there 
are no significant economic impacts on a substantial number of small 
entities from these amendments.

E. What are the benefits?

    As stated above in section V.C of this preamble, we were unable to 
quantify the specific emissions reductions associated with eliminating 
the SSM exemption, although this proposed change has the potential to 
reduce emissions of volatile organic HAP.
    Because these proposed amendments are not considered economically 
significant, as defined by Executive Order 12866, we did not monetize 
the benefits of reducing these emissions. This does not mean that there 
are no benefits associated with the potential reduction in volatile 
organic HAP from this rule.

VI. Request for Comments

    We solicit comments on 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 improvements to the 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 project website at https://www.epa.gov/stationary-sources-air-pollution/refractory-products-manufacturing-national-emissions-standards. 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 ``improved'' data that you have, if 
available. When you submit data, we request that you provide 
documentation of the basis for the revised values to support your 
suggested changes. To submit comments on the data

[[Page 3106]]

downloaded from the project 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-2020-0148 (through the method described in the 
ADDRESSES section of this preamble).
    5. If you are providing comments on a single facility or multiple 
facilities, you need only submit one file for all facilities. 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 project website at https://www.epa.gov/stationary-sources-air-pollution/refractory-products-manufacturing-national-emissions-standards .

VIII. Statutory and Executive Order Reviews

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

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is not a significant regulatory action and was, 
therefore, not submitted to OMB for review.

B. Executive Order 13771: Reducing Regulations and Controlling 
Regulatory Costs

    This action is not expected to be an Executive Order 13771 
regulatory action because this action is not significant under 
Executive Order 12866.

C. Paperwork Reduction Act (PRA)

    The information collection activities in this proposal have been 
submitted for approval to OMB under the PRA. The ICR document that the 
EPA prepared has been assigned EPA ICR number 2040.08. You can find a 
copy of the ICR in the docket for this rule, and it is briefly 
summarized here.
    As part of the RTR for the Refractory Products Manufacturing 
NESHAP, the EPA is not proposing to revise the existing emission limit 
requirements but is adding new emission limit requirements for existing 
clay refractory sources and is adding new work practices for existing 
nonclay refractory sources. The EPA is also proposing to revise the SSM 
provisions of the rule and proposing the use of electronic data 
reporting for future performance test data submittals, notifications, 
and reports. This information is being collected to assure compliance 
with 40 CFR part 63, subpart SSSSS.
    Respondents/affected entities: Facilities manufacturing refractory 
products.
    Respondent's obligation to respond: Mandatory (40 CFR part 63, 
subpart SSSSS).
    Estimated number of respondents: In the 3 years after the 
amendments are final, approximately three respondents per year would be 
subject to the NESHAP and no additional respondents are expected to 
become subject to the NESHAP during that period.
    Frequency of response: The total number of responses is 21 per 
year.
    Total estimated burden: The average annual burden to the three 
refractory products manufacturing facilities over the 3 years if the 
amendments are finalized is estimated to be 230 hours (per year). The 
average annual burden to the Agency over the 3 years after the 
amendments are final is estimated to be 202 hours (per year). Burden is 
defined at 5 CFR 1320.3(b).
    Total estimated cost: The average annual cost to the refractory 
products manufacturing facilities is $27,100 in labor costs in the 
first 3 years after the amendments are final. The average annual 
capital and operation and maintenance cost is $69,900. The total 
average annual Agency cost over the first 3 years after the amendments 
are final is estimated to be $9,990.
    An agency may not conduct or sponsor, and a person is not required 
to respond to, a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for the 
EPA's regulations in 40 CFR are listed in 40 CFR part 9.
    Submit your comments on the Agency's need for this information, the 
accuracy of the provided burden estimates, and any suggested methods 
for minimizing respondent burden to the EPA using the docket identified 
at the beginning of this rule. You may also send your ICR-related 
comments to OMB's Office of Information and Regulatory Affairs via 
email to OIRA_submission@omb.eop.gov, Attention: Desk Officer for the 
EPA. Since OMB is required to make a decision concerning the ICR 
between 30 and 60 days after receipt, OMB must receive comments no 
later than February 16, 2021. The EPA will respond to any ICR-related 
comments in the final rule.

D. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. The 
annualized costs associated with the proposed requirements in this 
action for the affected small entities is described in section V.D. 
above.

E. Unfunded Mandates Reform Act (UMRA)

    This action does not contain an unfunded mandate of $100 million or 
more as described in UMRA, 2 U.S.C. 1531-1538, and does not 
significantly or uniquely affect small governments. The action imposes 
no enforceable duty on any state, local, or tribal governments or the 
private sector.

F. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government.

G. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    This action does not have tribal implications as specified in 
Executive Order 13175. No tribal facilities are known to be engaged in 
any of the industries that would be affected by this action. In 
addition, the EPA conducted a proximity analysis for this source 
category and found that no refractory products manufacturing facilities 
are located within 50 miles of tribal lands. Thus, Executive Order 
13175 does not apply to this action.

H. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    This action is not subject to Executive Order 13045 because it is 
not economically significant as defined in Executive Order 12866, and 
because the EPA does not believe the environmental health or safety 
risks addressed by this action present a disproportionate risk to 
children. This action's health and risk assessments are contained in 
sections

[[Page 3107]]

III.A, IV.B, and IV.C of this preamble and are further documented in 
the Refractory Products Manufacturing Docket.

I. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use

    This action is not subject to Executive Order 13211 because it is 
not a significant regulatory action under Executive Order 12866.

J. National Technology Transfer and Advancement Act (NTTAA) and 1 CFR 
Part 51

    This action involves technical standards. Therefore, the EPA 
conducted searches for the Refractory Products Manufacturing RTR 
through the Enhanced National Standards Systems Network Database 
managed by the American National Standards Institute (ANSI). We also 
contacted voluntary consensus standards (VCS) organizations and 
accessed and searched their databases. We conducted searches for EPA 
Methods 1, 1A, 2, 2A, 2C, 2D, 2F, 2G, 3, 3A, 3B, 4, 5, 25, 25A, 26, 
26A, and 29 of 40 CFR part 60, and EPA Methods 311 and 320 of 40 CFR 
part 63, appendix A. No applicable VCS were identified for EPA Methods 
1A, 2A, 2D, 2F, 2G, 5A, 5B, 5D, and 5F.
    The EPA is incorporating by reference the VCS ANSI/ASME PTC 19.10-
1981, ``Flue and Exhaust Gas Analyses.'' This method determines 
quantitatively the gaseous constituents of exhausts resulting from 
stationary combustion sources. The manual procedures (but not 
instrumental procedures) of VCS ANSI/ASME PTC 19.10-1981--Part 10 may 
be used as an alternative to EPA Method 3B for measuring the oxygen or 
carbon dioxide content of the exhaust gas. The gases covered in ANSI/
ASME PTC 19.10-1981 are oxygen, carbon dioxide, CO, nitrogen, 
SO2, sulfur trioxide, nitric oxide, nitrogen dioxide, 
hydrogen sulfide, and hydrocarbons, however the use in this rule is 
only applicable to oxygen and carbon dioxide and is an acceptable 
alternative to the manual portion only and not the instrumental 
portion.
    The EPA is incorporating by reference the VCS ASTM D6348-12e1, 
``Determination of Gaseous Compounds by Extractive Direct Interface 
Fourier Transform (FTIR) Spectroscopy,'' as an acceptable alternative 
to EPA Method 320. ASTM D6348-03(2010) was determined to be equivalent 
to EPA Method 320 with caveats. ASTM D6348-12e1 is a revised version of 
ASTM D6348-03(2010) and includes a new section on accepting the results 
from the direct measurement of a certified spike gas cylinder, but 
lacks the caveats placed on the ASTM D6348-03(2010) version. The VCS 
ASTM D6348-12e1, ``Determination of Gaseous Compounds by Extractive 
Direct Interface Fourier Transform (FTIR) Spectroscopy,'' is an 
extractive FTIR field test method used to quantify gas phase 
concentrations of multiple analytes from stationary source effluent and 
is an acceptable alternative to EPA Method 320 at this time with 
caveats requiring inclusion of selected annexes to the standard as 
mandatory. When using ASTM D6348-12e1, the following conditions must be 
met:
    (1) The test plan preparation and implementation in the Annexes to 
ASTM D6348-03, Sections A1 through A8 are mandatory; and
    (2) In ASTM D6348-03, Annex A5 (Analyte Spiking Technique), the 
percent (%) R must be determined for each target analyte (Equation 
A5.5).
    In order for the test data to be acceptable for a compound, percent 
R must be 70 percent >= R <= 130 percent. If the %R value does not meet 
this criterion for a target compound, the test data is not acceptable 
for that compound and the test must be repeated for that analyte (i.e., 
the sampling and/or analytical procedure should be adjusted before a 
retest). The percent R value for each compound must be reported in the 
test report, and all field measurements must be corrected with the 
calculated percent R value for that compound by using the following 
equation:

Reported Results = ((Measured Concentration in Stack))/(%R) x 100.

    Finally, the EPA is incorporating by reference the VCS ASTM D6784-
16), ``Standard Test Method for Elemental, Oxidized, Particle-Bound and 
Total Mercury in Flue Gas Generated from Coal-Fired Stationary Sources 
(Ontario Hydro Method),'' as an acceptable alternative to EPA Method 29 
(portion for mercury only) as a method for measuring elemental, 
oxidized, particle-bound, and total mercury concentrations ranging from 
approximately 0.5 to 100 micrograms per normal cubic meter. This test 
method describes equipment and procedures for obtaining samples from 
effluent ducts and stacks, equipment and procedures for laboratory 
analysis, and procedures for calculating results. VCS ASTM D6784-16 
allows for additional flexibility in the sampling and analytical 
procedures for the earlier version of the same standard VCS ASTM D6784-
02 (Reapproved 2008).

K. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    The EPA believes that this action does not have disproportionately 
high and adverse human health or environmental effects on minority 
populations, low-income populations, and/or indigenous peoples, as 
specified in Executive Order 12898 (59 FR 7629, February 16, 1994).
    The documentation for this decision is contained in section IV.B of 
this preamble and the technical report titled Risk and Technology 
Review--Analysis of Demographic Factors for Populations Living Near 
Refractory Products Manufacturing Source Category Operations, September 
2020, available in the Refractory Products Manufacturing Docket, 
respectively.
    As discussed in section IV.B of this preamble, we performed a 
demographic analysis for each source category, which is an assessment 
of risks to individual demographic groups, of the population close to 
the facilities (within 50 km and within 5 km). In this analysis, we 
evaluated the distribution of HAP-related cancer risks and noncancer 
hazards from the Refractory Products Manufacturing source category 
across different social, demographic, and economic groups within the 
populations living near operations identified as having the highest 
risks.
    The results of the Refractory Products Manufacturing source 
category demographic analysis indicate that no one is exposed to a 
cancer risk at or above 1-in-1 million and no one is exposed to a 
chronic noncancer HI greater than 1.
    The proximity results (irrespective of risk) indicate that the 
population percentages for ``ages 18 to 64'' and ``ages 65 and up'' 
demographic categories located within 5 km of refractory products 
manufacturing facilities and ``ages 65 and up'' demographic categories 
located within 50 km of refractory products manufacturing facilities 
are slightly higher than their respective nationwide percentages.
    We do not expect this proposal to achieve significant reductions in 
HAP emissions. The EPA anticipates that this action does not have 
disproportionately high and adverse human health or environmental 
effects on minority populations, low-income populations, and/or 
indigenous peoples, as specified in Executive Order 12898 (59 FR 7629, 
February 16, 1994) because it does not significantly affect the level 
of protection provided to human health or the environment. The 
documentation

[[Page 3108]]

for this decision is contained in section IV of this preamble and the 
technical report titled Risk and Technology Review--Analysis of 
Demographic Factors for Populations Living Near Refractory Products 
Manufacturing Source Category Operations, September 2020, which are 
available in the Refractory Products Manufacturing Docket, 
respectively.

List of Subjects in 40 CFR Part 63

    Environmental protection, Air pollution control, Hazardous 
substances, Incorporation by reference, Reporting and recordkeeping 
requirements.

Andrew Wheeler,
Administrator.
[FR Doc. 2021-00137 Filed 1-13-21; 8:45 am]
BILLING CODE 6560-50-P