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Proposed Rule2023-16158

Revisions to the Air Emissions Reporting Requirements

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Published

August 9, 2023

Issuing agencies

Environmental Protection Agency

Abstract

This action proposes changes to the EPA's Air Emissions Reporting Requirements (AERR). The proposed amendments may require changes to current regulations of State, local, and certain tribal air agencies; would require these agencies to report emissions data to the EPA using different approaches from current requirements; and would require owners/operators of some facilities to report additional emissions data. More specifically, the EPA is proposing to require certain sources report information regarding emission of hazardous air pollutants (HAP); certain sources to report criteria air pollutants, their precursors and HAP; and to require State, local, and certain tribal air agencies to report prescribed fire data. The proposed revisions would also define a new approach for optional collection by air agencies of such information on HAP by which State, local and certain tribal air agencies may implement requirements and report emissions on behalf of owners/operators. The proposed revisions would also make the requirements for point sources consistent for every year; phase in earlier deadlines for point source reporting; and add requirements for reporting fuel use data for certain sources of electrical generation associated with peak electricity demand. The proposed revisions include further changes for reporting on airports, rail yards, commercial marine vessels, locomotives, and nonpoint sources. For owners/operators of facilities that meet criteria described in this proposal, the proposed revisions would require reporting of performance test and performance evaluation data to the EPA for all tests conducted after the effective date provided in the final rulemaking. The EPA also proposes to clarify that information the EPA collects through the AERR is emission data that is not subject to confidential treatment.

Full Text

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<title>Federal Register, Volume 88 Issue 152 (Wednesday, August 9, 2023)</title>
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[Federal Register Volume 88, Number 152 (Wednesday, August 9, 2023)]
[Proposed Rules]
[Pages 54118-54222]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-16158]

[[Page 54117]]

Vol. 88

Wednesday,

No. 152

August 9, 2023

Part V

Environmental Protection Agency

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40 CFR Parts 2 and 51

Revisions to the Air Emissions Reporting Requirements; Proposed Rule

Federal Register / Vol. 88, No. 152 / Wednesday, August 9, 2023 /
Proposed Rules

[[Page 54118]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 2 and 51

[EPA-HQ-OAR-2004-0489; FRL-8604-02-OAR]
RIN 2060-AV41

Revisions to the Air Emissions Reporting Requirements

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: This action proposes changes to the EPA's Air Emissions
Reporting Requirements (AERR). The proposed amendments may require
changes to current regulations of State, local, and certain tribal air
agencies; would require these agencies to report emissions data to the
EPA using different approaches from current requirements; and would
require owners/operators of some facilities to report additional
emissions data. More specifically, the EPA is proposing to require
certain sources report information regarding emission of hazardous air
pollutants (HAP); certain sources to report criteria air pollutants,
their precursors and HAP; and to require State, local, and certain
tribal air agencies to report prescribed fire data. The proposed
revisions would also define a new approach for optional collection by
air agencies of such information on HAP by which State, local and
certain tribal air agencies may implement requirements and report
emissions on behalf of owners/operators. The proposed revisions would
also make the requirements for point sources consistent for every year;
phase in earlier deadlines for point source reporting; and add
requirements for reporting fuel use data for certain sources of
electrical generation associated with peak electricity demand. The
proposed revisions include further changes for reporting on airports,
rail yards, commercial marine vessels, locomotives, and nonpoint
sources. For owners/operators of facilities that meet criteria
described in this proposal, the proposed revisions would require
reporting of performance test and performance evaluation data to the
EPA for all tests conducted after the effective date provided in the
final rulemaking. The EPA also proposes to clarify that information the
EPA collects through the AERR is emission data that is not subject to
confidential treatment.

DATES: Comments on this proposed rule must be received on or before
October 18, 2023. Under the Paperwork Reduction Act, comments on the
information collection request must be received by the EPA and OMB on
or before September 8, 2023.
Public hearing: The EPA will hold a virtual public hearing on
August 30, 2023. See SUPPLEMENTARY INFORMATION for additional
information on the public hearing.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2004-0489, by one of the following methods:
<bullet> <a href="http://www.regulations.gov">www.regulations.gov</a>: Follow the online instructions for
submitting comments.
<bullet> Email: <a href="/cdn-cgi/l/email-protection#056428646b61287728616a666e6071456075642b626a73">[email&#160;protected]</a>. Fax: (202) 566-9744.
<bullet> Mail: Air Emissions Reporting Requirements Rule, Docket
No. EPA-HQ-OAR-2004-0489, Environmental Protection Agency, Mailcode:
2822T, 1200 Pennsylvania Ave. NW, Washington, DC 20460. Please include
two copies.
<bullet> Hand Delivery: Docket No. EPA-HQ-OAR-2004-0489, EPA Docket
Center, Public Reading Room, EPA West, Room 3334, 1301 Constitution
Ave. NW, Washington, DC 20460. Such deliveries are only accepted during
the Docket's normal hours of operation, and special arrangements should
be made for deliveries of boxed information.
Instructions: All submissions received must include the Docket ID
No. for this rulemaking. Comments received may be posted without change
to <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>, including any personal information
provided. For detailed instructions on sending comments and additional
information on the rulemaking process, see the ``Public Participation''
heading of the SUPPLEMENTARY INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT: Mr. Marc Houyoux, Office of Air
Quality Planning and Standards, Air Quality Assessment Division,
Emission Inventory and Analysis Group (C339-02), U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711; telephone number:
(919) 541-3649; email: <a href="/cdn-cgi/l/email-protection#256b606c7a6d404955654055440b424a53">[email&#160;protected]</a> (and include ``AERR'' on the
subject line).

SUPPLEMENTARY INFORMATION:
Organization of this document. The information in this preamble is
organized as follows:

Table of Contents

I. Public Participation
II. General Information
III. Background and Purpose of This Rulemaking
A. Point Sources
1. Proposed Point Source Revisions Affecting Both States and
Owners/Operators
2. Additional Proposed Point Source Revisions Affecting States
3. Additional Reporting by Owners/Operators
B. Nonpoint Sources
1. Nonpoint Online Survey and Activity Data Requirements
2. Commercial Marine Vessel and Locomotive Emissions
Requirements
3. Nonpoint Sources Reported by States and Indian Tribes
C. Fires
D. Mobile Sources
E. Other Changes
IV. Proposed Revisions to Emissions Reporting Requirements
A. Emissions Data Collection of Hazardous Air Pollutants for
Point Sources
1. EPA Needs HAP Emissions for Regulatory Purposes
2. EPA Needs Emissions for Risk Assessment
3. EPA Needs HAP Emissions for Air Quality Modeling
4. Proposed HAP Reporting Requirements
5. Collecting HAP Annual Emissions
6. State Application for Voluntary HAP Reporting Responsibility
7. Review and Revisions to HAP Reporting Responsibility
8. Expansion of Point Source Definition To Include HAP
9. Special Cases of Emissions Thresholds for Non-Major Sources
10. Pollutants To Be Required or Optional for Point Sources
11. Reporting Release Coordinates
12. Reduced HAP Reporting Requirements for Small Entities
13. Emissions Estimation Tool for Small Entities
14. Definition of Small Entities
15. Reporting HAP and CAP for the Same Emissions Processes
16. Option To Include PFAS as a Required Pollutant
B. Collection of Emissions From Point Sources Not Reported by
States
1. Facilities on Land Not Reporting Under the Current AERR
2. Facilities Within Federal Waters
C. Source Test Reporting
D. Reporting for Certain Small Generating Units
E. Provisions for Portable and Offshore Sources
F. Reporting Deadlines for Point Sources
1. Deadlines for States for Point Sources
2. Annual Emissions Deadlines for Owners/Operators of Point
Sources
3. Summary of Reporting Deadlines and Phase-In Years
G. Point Source Reporting Frequency
H. Clarification About Confidential Treatment of Data
I. Additional Point Source Reporting Revisions
1. Formalizing the Approach for Aircraft and Ground Support
Equipment
2. Formalizing the Approach for Rail Yards
3. New Requirements for Point Source Control Data
4. New Requirements for Point Source Throughput in Specific
Units of Measure
5. New Requirement for Including Title V Permit Identifier

[[Page 54119]]

6. New Requirement to Use the Best Available Emission Estimation
Method
7. New Requirement to Use the Source Test Reports for Emission
Rates
8. New Requirement To Identify Regulations That Apply to a
Facility
9. Existing Regulatory Requirements to be Required by EPA Data
Systems
10. Option for Reporting Two-Dimensional Fugitive Release Points
11. Changes to Reporting the North American Industrial
Classification System Code
12. Clarification About Definition of the Facility Latitude/
Longitude
13. Clarification to Use the Latest Reporting Codes for
Electronic Reporting
14. Clarification About Reporting Individual Pollutants or
Pollutant Groups
15. Clarification About How To Report HAP That Are Part of
Compounds
16. Requirement to Includes Certain Mobile Sources Within Point
Source Reports
17. Cross-Program Identifiers Option
18. New Requirements When Using Speciation Profiles To Calculate
Emissions
19. New Requirement for Small Entity Type
J. Nonpoint Activity Data Reporting and Nonpoint Survey
K. Nonpoint Year-Specific Data and Timing of Reporting
L. Nonpoint Reporting for Tribes and States With Counties
Overlapping Indian Country
M. Requirements for Prescribed Burning
N. Revisions to Requirements for Agricultural Fires and Optional
Reporting for Wildfires
O. Revisions for Onroad and Nonroad Emissions Reporting for
California
P. Clarifications for Reporting Emission Model Inputs for Onroad
and Nonroad Sources
Q. Definition of Actual Emissions
R. Provisions for State Implementation Plans
1. Point Source Thresholds
2. Detail Required by Emission Inventory Provisions of SIP
Implementation Rules
3. Emission Inventory Years
S. Summary of Expected Timing for Proposed Revisions
V. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulations and Regulatory Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Act
D. Unfunded Mandates Reform Act (UMRA)
E. Executive Order 13132: Federalism
F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
G. Executive Order 13045: Protection of Children From
Environmental Health and Safety Risks
H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
I. National Technology Transfer and Advancement Act
J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations
K. Determinations Under CAA Section 307(b)(1) and (d)

I. Public Participation

The EPA will hold a virtual public hearing on August 30, 2023. The
hearing will convene at 10:00 a.m. Eastern Time (ET) and will conclude
at 4:00 p.m. ET. The EPA may close the hearing 15 minutes after the
last pre-registered speaker has testified if there are no additional
speakers. The EPA will announce any further details at <a href="https://www.epa.gov/air-emissions-inventories/air-emissions-reporting-requirements-aerr">https://www.epa.gov/air-emissions-inventories/air-emissions-reporting-requirements-aerr</a>.
Upon publication of this document in the Federal Register, the EPA
will begin pre-registering speakers for the hearing. The EPA will
accept registrations on an individual basis. To register to speak at
the virtual public hearing, please follow the instructions at <a href="https://www.epa.gov/air-emissions-inventories/air-emissions-reporting-requirements-aerr">https://www.epa.gov/air-emissions-inventories/air-emissions-reporting-requirements-aerr</a> or contact the public hearing team at 919-541-3391 or
by email at <a href="/cdn-cgi/l/email-protection#662109020014031f482c07080f05032603160748010910">[email&#160;protected]</a>. The last day to pre-register to
speak at the hearing will be August 25, 2023. Prior to the hearing, the
EPA will post a general agenda that will list pre-registered speakers
in approximate order at <a href="https://www.epa.gov/air-emissions-inventories/air-emissions-reporting-requirements-aerr">https://www.epa.gov/air-emissions-inventories/air-emissions-reporting-requirements-aerr</a>.
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 4 minutes to provide oral testimony. The
EPA encourages commenters to provide the EPA with a copy of their 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.
Any updates made to any aspect of the hearing will be posted online
at <a href="https://www.epa.gov/air-emissions-inventories/air-emissions-reporting-requirements-aerr">https://www.epa.gov/air-emissions-inventories/air-emissions-reporting-requirements-aerr</a>. The EPA does not intend to publish a
document in the Federal Register announcing updates. While the EPA
expects the hearing to go forward as described in this section, please
monitor <a href="https://www.epa.gov/air-emissions-inventories/air-emissions-reporting-requirements-aerr">https://www.epa.gov/air-emissions-inventories/air-emissions-reporting-requirements-aerr</a> for any updates to the information
described in this document, including information about the public
hearing.
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 contact listed above and describe
your needs by August 16, 2023. The EPA may not be able to arrange
accommodations without advance notice.
Docket. The EPA has established a docket for this rulemaking under
Docket ID No. EPA-HQ-OAR-2004-0489. All documents in the docket are
listed in <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>. 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 either electronically in <a href="http://Regulations.gov">Regulations.gov</a> or in
hard copy at the EPA Docket Center, Room 3334, WJC West Building, 1301
Constitution Avenue NW, Washington, DC. The Public Reading Room is open
from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal
holidays. The telephone number for the Public Reading Room is (202)
566-1744, and the telephone number for the EPA Docket Center is (202)
566-1742.
Instructions. Direct your comments to Docket ID No. EPA-HQ-OAR-
2004-0489. 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 <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>, 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 to <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>
any information that you consider to be CBI or other information whose
disclosure is restricted by statute. This type of information should be
submitted as discussed in the Submitting CBI section of this document.
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

[[Page 54120]]

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 <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.
The <a href="https://www.regulations.gov/">https://www.regulations.gov/</a> 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
<a href="https://www.regulations.gov/">https://www.regulations.gov/</a>, your email address will be automatically
captured and included as part of the comment that is placed in the
public docket and made available on the internet. If you submit an
electronic comment, the EPA recommends that you include your name and
other contact information in the body of your comment and with any
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 <a href="https://www.epa.gov/dockets">https://www.epa.gov/dockets</a>.
Submitting CBI. Do not submit information containing CBI to the EPA
through <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>. Clearly mark the part or all the
information that you claim to be CBI. For CBI information on any
digital storage media that you mail to the EPA, note the docket ID,
mark the outside of the digital storage media as CBI, and 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 the Instructions section of this document. 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 and
note the docket ID. 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.
Our preferred method to receive CBI is for it to be transmitted
electronically using email attachments, File Transfer Protocol (FTP),
or other online file sharing services (e.g., Dropbox, OneDrive, Google
Drive). Electronic submissions must be transmitted directly to the
OAQPS CBI Office at the email address <a href="/cdn-cgi/l/email-protection#59363828292a3a3b30193c2938773e362f">[email&#160;protected]</a>, and as
described above, should include clear CBI markings and note the docket
ID. If assistance is needed with submitting large electronic files that
exceed the file size limit for email attachments, and if you do not
have your own file sharing service, please email <a href="/cdn-cgi/l/email-protection#98f7f9e9e8ebfbfaf1d8fde8f9b6fff7ee">[email&#160;protected]</a> to
request a file transfer link. If sending CBI information through the
postal service, please send it 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-2004-0489. The mailed CBI material should be double wrapped
and clearly marked. Any CBI markings should not show through the outer
envelope.

Expedited Comment Review

To expedite review of your comments by agency staff, you are
encouraged to send a courtesy copy of your comments, in addition to the
copy you submit to the official docket, to Mr. EPA-Anonymous, U.S. EPA,
Office of Air Quality Planning and Standards, Air Quality Assessment
Division, Emission Inventory and Analysis Group, Mail Code C339-02,
Research Triangle Park, NC 27711; telephone: (919) 541-3649; email:
<a href="/cdn-cgi/l/email-protection#014f44485e49646d71416471602f666e77">[email&#160;protected]</a> and include ``AERR'' on subject line.

II. General Information

Does this action apply to me?

Categories and entities potentially regulated by this action
include:

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Category NAICS code \a\ Examples of regulated entities
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State/local/tribal government........... 92411...................... State, territorial, and local government
air quality management programs. Tribal
governments are not affected, unless
they have sought and obtained treatment
in the same manner as a State under the
Clean Air Act and Tribal Authority Rule
and, on that basis, are authorized to
implement and enforce the Air Emissions
Reporting Requirements rule.
Major sources........................... Any........................ Owners/operators of facilities.
Other (than major) sources.............. ........................... Owners/operators of facilities of:
21xxxx, 22xxxx, 3xxxxx Industrial and manufacturing industries.
except for 311811.
4247xx..................... Petroleum and Petroleum Products Merchant
Wholesalers.
481xxx..................... Scheduled Air Transportation.
486xxx..................... Pipeline Transportation.
4883xx..................... Support Activities for Water
Transportation.
493xxx..................... Warehousing and Storage.
5417xx..................... Scientific Research and Development
Services.
54199x..................... Other Professional, Scientific, and
Technical Services.
56191x..................... Packaging and Labeling Services.
5622xx..................... Waste Treatment and Disposal.
5629xx..................... Waste Management and Remediation
Services.
61131x..................... Colleges, Universities, and Professional
Schools.
62211x..................... General Medical and Surgical Hospitals.
62231x..................... Specialty (except Psychiatric and
Substance Abuse) Hospitals.
811121..................... Automotive Body, Paint and Interior
Repair and Maintenance \b\.
8122xx..................... Death Care Services.
812332..................... Industrial Launderers.
92214x..................... Correctional Institutions.
927xxx..................... Space Research and Technology.

[[Page 54121]]

928xxx..................... National Security and International
Affairs.
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\a\ North American Industry Classification System.
\b\ Excluding small businesses for primary NAICS 811121.

This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be regulated by this
action. This table lists the types of entities that could potentially
be regulated by this action. Other types of entities not listed in the
table could also be regulated. To determine whether your entity could
be regulated by this proposed action, you should carefully examine the
proposed revisions to the applicability criteria found in Sec. 51.1 of
the proposed regulatory text within this action. If you have any
questions regarding the applicability of this action to a particular
entity, consult the person listed in the FOR FURTHER INFORMATION
CONTACT section.

III. Background and Purpose of This Rulemaking

Background: The EPA promulgated the Air Emissions Reporting
Requirements (AERR, 73 FR 76539, December 17, 2008) to consolidate and
harmonize the emissions reporting requirements of the oxides of
nitrogen (NO<INF>X</INF>) State Implementation Plan (SIP) Call (73 FR
76558, December 17, 2008, as amended at 80 FR 8796, February 19, 2015;
84 FR 8443, March 8, 2019) and the Consolidated Emissions Reporting
Rule (CERR, 67 FR 39602, June 10, 2002) with the needs of the Clean Air
Interstate Rule (CAIR, 70 FR 25161, May 12, 2005). The EPA subsequently
promulgated revisions of Subpart A (80 FR 8787, February 19, 2015), to
align Subpart A with the revised National Ambient Air Quality Standard
(NAAQS) for Lead (Pb) (73 FR 66964, November 12, 2008) and the
associated Revisions to Lead Ambient Air Monitoring Requirements (75 FR
81126, December 27, 2010), and to reduce burden on States and local air
agencies by making minor technical corrections. On August 24, 2016, the
EPA further revised Subpart A (80 FR 58010) with the promulgation of
the particulate matter (PM) with an aerodynamic diameter less than or
equal to 2.5 microns (PM<INF>2.5</INF>) SIP Requirements Rule to update
the emissions reporting thresholds in Table 1 to Appendix A of this
subpart.
Under the current AERR, State, local, and some tribal agencies \1\
are required to report emissions of criteria air pollutants and
precursors (collectively, CAPs) to EPA. Required pollutants under the
current rule are carbon monoxide (CO), NO<INF>X</INF>, volatile organic
compounds (VOC), sulfur dioxide (SO<INF>2</INF>), ammonia
(NH<INF>3</INF>), PM<INF>2.5</INF>, PM with an aerodynamic diameter
less than or equal to 10 microns (PM<INF>10</INF>), and Pb. Further,
these agencies may optionally report emissions of HAP and other
pollutants. For simplicity in the remainder of this document, the term
``States'' will be used to denote all agencies that are currently
reporting or that could/would report under any revision to the AERR
(see 40 CFR 51.1(b) and (e) of this proposed action). Some facilities
must be reported as point sources (as defined by the current AERR at 40
CFR 51.50) based on potential-to-emit (PTE) reporting thresholds for
CAPs and an actual emissions reporting threshold for Pb. The current
AERR includes a lower set of point source reporting thresholds for
every third year and, thus, States are required to report more
facilities as point sources on these triennial inventory years. The
remaining requirements in the current rule are for the triennial
inventories only, for which stationary sources must be reported as
county total ``nonpoint'' sources. Agricultural burning is included as
a nonpoint source. States, except for California, must also provide
inputs to the MOtor Vehicle Emissions Simulator (MOVES), while
California must submit CAP emissions for onroad vehicles and nonroad
equipment. States are also encouraged to participate in voluntary
reporting of wildfire and prescribed burning activity data, such as the
location and size of burning.
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\1\ As prescribed by the Tribal Authority Rule (63 FR 7253,
February 12, 1998), codified at 40 CFR part 49, subpart A, tribes
may elect to seek treatment in the same manner as a state (TAS)
status and obtain approval to implement rules such as the AERR
through a Tribal Implementation Plan (TIP), but tribes are under no
obligation to do so. However, those tribes that have obtained TAS
status for this purpose are subject to the Subpart A requirements to
the extent allowed in their TIP. Accordingly, to the extent a tribal
government has applied for and received TAS status for air quality
control purposes and is subject to the Subpart A requirements under
its TIP, the use of the term State(s) in Subpart A shall include
that tribe.
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In addition to the annual and triennial reporting requirements in
the current rule, the AERR serves as the reference for the
NO<INF>X</INF> SIP Call (40 CFR part 51 Subpart G), Regional Haze
requirements (50 CFR part 51, subpart P), Ozone SIP Requirements Rules
(40 CFR part 51, subparts X, AA, and CC) and the PM<INF>2.5</INF> SIP
Requirements Rule (40 CFR part 51, subpart Z). These other rules point
to the AERR to define certain requirements related to emissions
inventories for SIPs, collectively known as SIP planning inventories.
Purpose: The proposed amendments in this action would ensure that
the EPA has sufficient information to identify and solve air quality
and exposure problems. The proposed amendments would also allow the EPA
to have information readily available that the Agency needs to protect
public health and perform other activities under the Clean Air Act (CAA
or ``the Act''). Further, the proposed amendments would ensure that
communities have the data needed to understand significant sources of
air pollution that may be impacting them--including potent carcinogens
and other highly toxic chemicals linked with a wide range of chronic
and acute health problems. The EPA has taken a systematic approach in
developing this proposed action to ensure that key emissions
information is collected in a streamlined way, while preventing
unnecessary impacts to small entities within the communities we seek to
inform and protect. The proposed amendments would continue EPA's
partnership with States in a way that also respects the cooperative
federalism framework provided by the CAA.
Authority: Pursuant to its authority under sections 110, 172, and
the various NAAQS-specific sections of the CAA, the EPA has required
the preparation of SIPs to include inventories containing information
about criteria pollutant emissions and their precursors (e.g., VOC).
The EPA codified these inventory requirements in Subpart Q of 40 CFR
part 51 in 1979 and amended them in 1987. The 1990 Amendments to the
CAA revised many of the CAA provisions related to the attainment of the
NAAQS and the protection of visibility in Class I areas. These
revisions established new periodic emission inventory requirements
applicable to certain areas that were designated nonattainment for
certain pollutants. For example, section 182(a)(3)(A) required States
to submit an emission inventory every 3 years for Moderate ozone
nonattainment areas beginning in 1993. Similarly, section 187(a)(5)
required States to submit an

[[Page 54122]]

inventory every 3 years for Moderate CO nonattainment areas.
The EPA promulgated the original AERR in 2008 with the intent of
streamlining various reporting requirements including those of CAA
section 182(a)(3)(A) for ozone nonattainment areas and section
187(a)(5) for CO nonattainment areas, those under the NO<INF>X</INF>
SIP Call (40 CFR 51.122), and the annual reporting requirements of the
CERR. The original AERR and its subsequent 2015 revision stem from
these various CAA authorities in sections 110, 114, 172, 182, 187, 189,
and 301(a). Likewise, the authority for the EPA to amend the reporting
requirements for CAPs, as proposed in this action, stems from these
same CAA provisions that the EPA relied upon to promulgate the original
AERR and amend it in the past. The EPA is not reopening any aspects of
the AERR except for those where we are proposing revisions or taking
comment as described in this preamble and the accompanying draft
regulatory text revisions.
This proposed action would additionally require that owners/
operators of certain point sources report certain information on HAP to
support the EPA and State needs for HAP data. Sections 114(a)(1) and
301(a) of the CAA provide the authority for the HAP reporting
requirements contained in this proposed action. These provisions
authorize the EPA to collect data routinely from owners/operators of
emissions sources and other entities for the purpose of carrying out
the provisions of the Act.
Section 114(a)(1) of the CAA authorizes the Administrator to, among
other things, require certain persons (explained below) on a one-time,
periodic, or continuous basis to keep records, make reports, undertake
monitoring, sample emissions, or provide such other information as the
Administrator may reasonably require. The EPA may require this
information of any person who (i) owns or operates an emission source,
(ii) manufactures emission control or process equipment, (iii) the
Administrator believes may have information necessary for the purposes
set forth in CAA section 114(a), or (iv) is subject to any requirement
of the Act (except for manufacturers subject to certain Title II
requirements). The information may be required for the purposes of: (1)
developing an implementation plan such as those under sections 110 or
111(d), (2) developing an emission standard under sections 111, 112, or
129, (3) determining if any person is in violation of any standard or
requirement of an implementation plan or emissions standard, or (4)
``carrying out any provision'' of the Act (except for a provision of
Title II with respect to manufacturers of new motor vehicles or new
motor vehicle engines).\2\
---------------------------------------------------------------------------

\2\ Although there are exclusions in CAA section 114(a)(1)
regarding certain Title II requirements applicable to manufacturers
of new motor vehicle and motor vehicle engines, section 208
authorizes the gathering of information related to those areas.
---------------------------------------------------------------------------

The scope of the persons potentially subject to a section 114(a)(1)
information request (e.g., a person ``who the Administrator believes
may have information necessary for the purposes set forth in'' section
114(a)) and the reach of the phrase ``carrying out any provision'' of
the Act are quite broad. The EPA's authority to request information
extends to persons not otherwise subject to CAA requirements and may be
used for purposes relevant to any provision of the Act. It is
appropriate for the EPA to gather the emissions data required by this
proposed action because such information is relevant to EPA's ability
to carry out a wide variety of CAA provisions, as illustrated by the
following description of the uses of such emissions data by EPA.
The EPA's need for CAP emissions data is well documented by the
existing records for the various past AERR rulemaking actions that are
located in the docket for this proposed action. Since the prior AERR
promulgation, the EPA has recognized a gap in the current AERR approach
to collect CAP emissions from all relevant facilities. The current AERR
imposes a requirement on States to ``inventory emission sources located
on nontribal lands and report this information to EPA.'' 40 CFR 51.1
(emphasis added). First, the phrase ``nontribal lands'' is not defined
and may lead to confusion. Further, data from sources located within
the geographic scope of Indian country (as defined by 18 U.S. C. 1151)
are relevant for many purposes, including regional and national
analyses to support the implementation of the Regional Haze Program and
NAAQS for ozone and PM<INF>2.5.</INF> To address this explicit data
gap, the EPA proposes, based on the authority provided by CAA section
114(a), to require reporting directly from certain facilities to the
EPA. Specifically, the EPA is proposing that facilities located within
Indian country for which the relevant tribe does not have Treatment as
a State (TAS) status or approval to submit emissions through a Tribal
Implementation Plan (TIP), and which are outside the geographic scope
of the relevant State's implementation planning authority,\3\ will
report directly to EPA.
---------------------------------------------------------------------------

\3\ EPA is using the phrase ``implementation planning
authority'' in this context to reflect the fact that in some cases,
States may administer approved SIPs in certain areas of Indian
country. For instance, in Oklahoma Dept. of Envtl. Quality v. EPA,
740 F.3d 185 (D.C. Cir. 2014), the D.C. Circuit held that States
have initial CAA implementation planning authority in non-
reservation areas of Indian country until displaced by a
demonstration of tribal jurisdiction over such an area. Under the
D.C. Circuit's decision, the CAA does not provide authority to
States to implement SIPs in Indian reservations. However, there are
also uncommon circumstances where another federal statute provides
authority for a particular State to administer an approved
implementation plan in certain areas of Indian country, which may
include certain Indian reservations.
---------------------------------------------------------------------------

The EPA's need for HAP emissions data stems from CAA requirements
that the EPA is expected to meet. For example, the EPA has many
authorities and obligations for air toxic regulatory development under
the many provisions of CAA section 112, including technology reviews
pursuant to CAA section 112(d)(6), and risk reviews under CAA section
112(f)(2). EPA's implementation of these provisions is additionally
informed by federal policy on environmental justice, including
Executive Order 12898, which overlays environmental justice
considerations for the EPA to assess as part of such work. HAP
emissions data also would be useful in further refining chemical
speciation to better meet the Agency's responsibilities under CAA Part
D that require air quality modeling using emissions data to support
NAAQS implementation. VOC chemical speciation is a critical part of
such modeling and can be informed by emissions of HAP VOC. The EPA is
additionally authorized (and in some cases, obligated) to assess the
risks of pollutants, which requires an understanding of both toxicity
and exposure. The EPA Office of Air and Radiation (OAR) prioritizes
chemicals to nominate for toxicity assessment under EPA's Integrated
Risk Information System (IRIS) program in part based on their potential
for exposure and hazard. HAP emissions data are used to support these
prioritization efforts. Finally, the EPA implements compliance and
enforcement programs per CAA sections 113 and 114(a), (b), and (d), and
HAP emissions data would support prioritization of those compliance and
enforcement efforts. This discussion is not a comprehensive listing of
all the possible ways the HAP information collected under this proposed
action would assist the EPA in carrying out any provision of the CAA.
Rather it illustrates how the information request

[[Page 54123]]

fits within the parameters of EPA's CAA authority.
The EPA has also identified that many air emissions sources
operating in Federal waters are not subject to emissions reporting
under this subpart. The CAA section 328 provides the EPA the authority
to ``establish requirements to control air pollution from Outer
Continental Shelf sources located offshore of the States along the
Pacific, Artic, and Atlantic Coasts, and along the United States Gulf
Coast off the State of Florida eastward of longitude 87 degrees and 30
minutes (``OCS sources'') to attain and maintain Federal and State
ambient air quality standards and to comply with the provisions of part
C of subchapter I of [the CAA].'' To support the Agency in carrying out
this function under the CAA, including data gathering for OCS sources,
the EPA is proposing revisions to this subpart for owners/operators of
such sources to report emissions data to EPA.

A. Point Sources

With this action, the EPA proposes amendments that would ensure HAP
emissions data are collected consistently for the benefit of
communities across the country. Currently, the availability and detail
of HAP emissions data vary across States, which creates a situation
where some communities have incomplete or less accurate information
than others, while still facing the same or greater potential risks. To
accomplish this within the authorities provided by the CAA, the EPA
proposes new requirements on owners/operators under CAA Part A to
report HAP emissions directly to EPA. Consistent with provisions of the
current version of the AERR, the EPA proposes to retain State reporting
of CAPs under CAA Part D, retain voluntary State reporting of HAP, and
proposes an approach by which a State may report HAP emissions on
behalf of sources in that State. As part of these proposed revisions,
the EPA is proposing changes to the AERR-specific definition of point
sources that would address which sources would be required to report
based on HAP emissions.
To reduce the possibility of redundant or conflicting HAP emissions
reports coming to the EPA from both States and owners/operators of
facilities, this action proposes that States may elect to assume an
owner/operator's responsibility for HAP reporting, provided that the
State receives EPA approval that its HAP reporting rules satisfy the
proposed requirements that would otherwise need to be met by owners/
operators. Requirements for owners/operators would continue unless and
until the EPA approves the State program, at which point it would
become a State's responsibility (i.e., State reporting would no longer
be voluntary for that State). In such cases, the requirement for
owners/operators to report directly to the EPA under this proposed
action would be suspended provided that the State continued to have the
responsibility and obligation to report the source's emissions.
Owners/operators already report HAP to many States. To allow for
the EPA and States to streamline reporting for owners/operators, the
EPA proposes to require owners/operators to report to the EPA using the
Combined Air Emissions Reporting System (CAERS). This emissions
collection system has been developed by the EPA to streamline reporting
from owners/operators to multiple EPA and State programs. While this
proposed amendment would add reporting requirements on owners/
operators, CAERS can offset and even reduce total burden by providing
owners/operators a way to report to the National Emissions Inventory
(NEI), Toxics Release Inventory (TRI), as well as State programs. The
EPA plans future enhancements to CAERS to share emissions data with the
Greenhouse Gas (GHG) Reporting Program (GHGRP) and the Consolidated
Emissions Data Reporting Interface (CEDRI), which will help owners/
operators further streamline their reporting requirements.
This proposed action does not require States to use CAERS, but the
EPA expects its use would help streamline emissions reporting efforts
for facilities, prevent duplication of effort, and lessen burden on
States for maintaining their own emissions collection systems. The EPA
proposes that if the EPA approves a State for HAP reporting under the
proposed option for doing so, a State would be able to continue using
their existing emissions reporting forms and approaches provided that
such approaches were updated to reflect any new AERR requirements.
Depending on choices made by a State, owners/operators would either
report to the EPA using CAERS, to the State using CAERS or a State
system, or to CAERS for HAP and to a State system for pollutants
required by the State.
The EPA is aware that some current State regulations have more
stringent HAP reporting requirements than those proposed in this
action. Similarly, EPA anticipates that future State regulations could
be more stringent as well. A State could require reporting by owners/
operators of facilities and for pollutants that would not otherwise be
regulated based on this proposed action. If that occurs, a State that
is approved to report HAP would be obligated only to report to the EPA
those facilities and pollutants that would be required by this proposed
action.
The proposed amendments would also rely on reporting by owners/
operators directly to the EPA to ensure data for all pollutants are
submitted by facilities that are outside the State's implementation
planning authority. Most facilities of this type are located within
Indian country and within Federal waters. Under the current AERR,
emissions from these facilities are only reported to the EPA if a tribe
chooses to do so, either voluntarily or through a formal TIP in which
the tribe has accepted the AERR reporting requirements. The EPA also
collects data from the Bureau of Ocean Energy Management (BOEM) for
certain offshore facilities within their jurisdiction. In the current
AERR, States do not report emissions data from federally permitted
facilities within Indian country or elsewhere that are not regulated by
a State. The current AERR and this proposed revision defines certain
facilities as ``point sources'' to ensure that the EPA has detailed
data on individual facilities when needed. The proposed amendments
would ensure that point source facilities and their emissions are
reported to the EPA either via the State where appropriate or by
owners/operators. This requirement would apply regardless of whether a
facility is located within Indian country, offshore, or other
locations.
A summary of requirements and major impacts compared to the current
rule are described in three sections below: (1) proposed point source
revisions affecting both States and owners/operators, (2) proposed
point source revisions affecting States, and (3) proposed point source
revisions affecting owners/operators.
1. Proposed Point Source Revisions Affecting Both States and Owners/
Operators
The EPA proposes to require owners/operators of certain facilities
(i.e., ``point sources'' as defined by the proposed action) to report
annual actual emissions of HAP directly to the EPA for the NEI, and the
EPA proposes an option for States to accept the reporting
responsibility on behalf of owners/operators within their State. Even
for owners/operators who also must report emissions to the TRI program,
this proposed action would require additional sub-facility details
necessary for air quality modeling that, in turn, would allow the EPA
to assess local-

[[Page 54124]]

scale community impacts and devise solutions for high-risk areas.
For States, the proposed requirement for direct facility reporting
would provide a new option not currently available under the current
AERR. States may opt to use HAP data provided by the EPA through CAERS
to inform their communities instead of promulgating or revising their
own rules to collect that data. Alternatively, a State may opt to
create or revise its own HAP emissions reporting requirements to comply
with the proposed requirements of this action. Regarding CAP, States
would be required to report CAP for all facilities with emissions
greater than or equal to CAP reporting thresholds within their
implementation planning authority.
This action also proposes new point source reporting requirements
for States and owners/operators of facilities within Indian country to
report daily activity data (i.e., fuel use or heat input) for certain
small generating units operated to help meet electricity needs on high
electricity demand days (HEDDs). The EPA describes a proposed
requirement and several alternatives for which small generating units
would need to report, with the goal of improving characterization of
emissions associated with HEDDs. The emissions from the small
generating units can be significant when deployed synchronously by many
facilities and can contribute to ozone formation. To allow the EPA and
States to have the necessary data to improve characterization of these
emissions sources and associated air quality events, the proposed
amendments would require States to report daily fuel use or heat input
for certain units. These proposed changes differ from the current AERR
because they require daily activity data for a specific type of
equipment at facilities, whereas the current AERR only requires annual
emissions values or, if these small generating units are not located at
a point source, no emissions reports. Under this proposed action,
owners/operators of facilities within Indian country would also need to
meet the same activity reporting requirements as States.
The EPA is also proposing that the definition of point sources
would use the same emissions reporting thresholds for every year, such
that States and owners/operators would report emissions for the same
sources every year starting with the 2026 inventory year. This
contrasts with the current requirements that use higher reporting
thresholds for every 2 out of 3 years. This proposed requirement would
allow communities, States, and the EPA to have the latest emissions
data from all facilities, know whether facilities have installed
emissions controls or taken other measures to reduce emissions, and be
notified as soon as possible when emissions have changed. This proposed
requirement would also ensure that States and the EPA have the most up-
to-date emissions data to make informed, timely decisions for
regulatory and other actions.
This proposed action would additionally distinguish portable
facilities from mobile sources operated solely for the functioning of
one or more stationary facilities (such as mines) and would clarify
requirements for both types of sources. The current AERR does not
address these types of sources specifically, and as a result, while the
EPA has expected these sources to be included in emissions reports as
part of the current ``all emissions'' clause of the existing 40 CFR
51.15(a)(1), the EPA has not always received portable facility
emissions or data about mobile sources operating at facilities. To
improve data quality related to such sources, the EPA proposes to
include portable facilities in the AERR-specific definition of point
sources that are subject to emissions reporting. The EPA also proposes
that mobile sources operating solely for the function of one or more
stationary facilities would need to be reported with the facilities'
emissions reports. This would impact both States and owners/operators
of facilities that are reporting directly to EPA. The EPA additionally
seeks comment on an option for how the EPA could define portable
sources for reporting under this subpart.
The current AERR has ambiguous statements regarding confidential
data that, in the past, have been misinterpreted by States when
reporting emissions. This proposed action would clarify the AERR
definition of confidential data by specifically referencing provisions
of the Act and existing law that define ``emissions data,'' identifying
components such as load, operating conditions, and process data, and
clarifying that such data cannot be treated as confidential by the
States or by owners/operators when such data would be required to be
reported by this proposed action.
The EPA also proposes to add additional required data fields for
point source reporting, which would affect both States and owners/
operators of facilities. First, the EPA proposes to require
identification of all federally enforceable regulations that apply to
each unit at certain facilities for the purpose of providing a
repository documenting the regulations a facility has determined apply
to its units. Such a repository would support streamlining of various
aspects of the EPA and State activities. Second, the EPA proposes to
require Title V permit numbers for major sources. Third, this action
proposes to require a summed activity level for fuel use from
combustion sources at each facility using standard units of measure for
the purpose of preventing double counting with nonpoint emissions.
States have the option to provide that summed data across all
facilities for which they report emissions but would need to collect
that data annually from their facilities to comply with this
requirement. Finally, the EPA proposes to include several new fields to
require States and facilities to better specify their control devices
and impacts of those controls on reducing emissions.
This action also proposes to add a requirement for location
information (i.e., latitude and longitude) for stack and fugitive
release points, which has previously been voluntary. The release point
locations are essential to correctly model and estimate risk associated
with HAP. The current AERR requires only a single facility-wide
location. Both States and owners/operators would be impacted by this
proposed revision.
2. Additional Proposed Point Source Revisions Affecting States
The EPA proposes a new approach for States to provide emissions
data for aircraft, ground support equipment (GSE), and rail yards for
triennial inventory years. Many States have voluntarily provided this
information for past triennial inventories, with the EPA providing
landing and takeoff (LTO) data for aircraft and emissions for rail
yards for State review and comment. This action proposes to require
States to treat these sources as point sources and to either (1) report
aircraft activity data (i.e., LTO data) for some or all aircraft and
emissions from rail yards, (2) report emissions for some or all
aircraft, GSE, and some or all rail yards, or (3) comment on and/or
accept EPA's activity data and emissions estimates.
The EPA also proposes a clarification that offshore facilities
(e.g., oil platforms) within State waters be reported by States when
such facilities meet the proposed point source reporting thresholds
included in this action. The current AERR does not specifically
indicate whether offshore facilities should be included or not, but the
current AERR does require States to report ``all stationary sources.''
Under the current rule, however, the EPA has not consistently received
emissions data

[[Page 54125]]

from States for these sources. Since the NEI is intended to be a
complete dataset of all emissions sources, these omissions prevented
complete information from being available to coastal communities and
EPA. Therefore, this action proposes to include stationary and portable
(e.g., floating drill rig) offshore sources (excluding commercial
marine vessel emissions) in State waters as point sources that would be
reported to the EPA when such sources meet the proposed emissions
reporting thresholds in this action.
3. Additional Reporting by Owners/Operators
Under the current AERR, use of the phrase ``nontribal lands'' in 40
CFR 51.1 may cause confusion in attempting to identify the geographic
areas within a State's borders for which the State should report
emissions data. Further, the Agency does not, under the current AERR,
receive emissions data from facilities located within Indian
reservations except in a few cases where the relevant Indian tribe has
an approved TIP or the tribe chooses to report voluntarily. This is
consistent with the intended scope of reporting under the current AERR.
Similarly, owners/operators of facilities operating in Federal waters
are not subject to reporting. This proposal would ensure that emissions
from facilities that meet the AERR emissions reporting thresholds would
be reported to the EPA by owners/operators when States do not report
them.
The EPA additionally proposes to require owners/operators of
facilities to report the results of stack tests and performance
evaluations (generally, called ``source tests'') electronically to the
CEDRI system when not otherwise reported to EPA. Source tests are
activities that demonstrate emissions and emission rates of air
pollutants from stationary sources though prescribed methods.
``Electronic source test reporting'' is using CEDRI to transfer the
results of the tests through the internet. The EPA needs these data to
develop and improve emissions factors. Many stakeholders including
States and industry have previously asked the EPA to improve its
emissions factors. Likewise, in 2006, EPA's Inspector General urged the
EPA to improve both emissions factor quality and quantity in its report
``EPA Can Improve Emissions Factors Development and Management.'' \4\
To implement those recommendations, the EPA created the CEDRI and
WebFIRE data systems; however, calculations to create revised emissions
factors depend on test data measured at sources. By requiring reporting
of these data to CEDRI, the EPA will be able to use the data systems as
planned to develop and improve the emissions factors.
---------------------------------------------------------------------------

\4\ See <a href="https://www.epa.gov/office-inspector-general/report-epa-can-improve-emissions-factors-development-and-management">https://www.epa.gov/office-inspector-general/report-epa-can-improve-emissions-factors-development-and-management</a>.
---------------------------------------------------------------------------

B. Nonpoint Sources

The EPA proposes to revise emissions reporting by States for
nonpoint sources (as defined in the AERR at 40 CFR 51.50) to improve
data quality, consistency, and transparency for triennial reporting.
These proposed revisions are based on an evolution of voluntary
approaches that have been implemented under the current AERR and
evaluated by the EPA while implementing the last several triennial
NEIs. If finalized, this proposed action would make mandatory those
currently voluntary approaches that support collaboration between
States and the EPA on nonpoint source emissions to make the needed
improvements.
1. Nonpoint Online Survey and Activity Data Requirements
The EPA is proposing to add a requirement for States to complete an
online survey about their planned submissions for nonpoint sources so
that the EPA could anticipate the States' intentions for accepting EPA
data or reporting their own data. Currently implemented on a voluntary
basis, this survey greatly assists States and the EPA in the quality
assurance (QA) that compares what States submitted to the EPA to what
States intended to submit. The nonpoint survey also provides States a
way to indicate for each emissions sector whether they accept the EPA
estimates.
The EPA is also proposing to add a requirement for States to report
input data for EPA's nonpoint emissions tools and spreadsheet
(hereafter referenced as ``tools''). This would allow States to meet
nonpoint source reporting requirements by reviewing, commenting on, or
editing EPA-provided nonpoint tool inputs. As part of this proposed
changed, the EPA proposes that for sources with EPA tools, States can
optionally report emissions, but if they chose to report emissions,
States would need to include documentation of those emissions. These
proposed changes differ from the current rule, which does not require
the survey, emission tool inputs, or documentation, but rather requires
States to report emissions. These proposed revisions should reduce
burden for States when they accept EPA's data or report input data to
nonpoint emissions calculation tools, rather than calculating and
reporting emissions themselves. Furthermore, the EPA would be better
equipped to perform QA in situations where State data differ from EPA
tool default estimates and evaluate the cause and reasonableness of
differences between State and EPA emissions estimates.
2. Commercial Marine Vessel and Locomotive Emissions Requirements
For commercial marine vessel and underway (i.e., moving) locomotive
emissions, the EPA proposes to add a clarifying statement about
treating such sources as nonpoint sources for submission to the EPA
under the AERR. The EPA also proposes to require States to report
emissions data associated with EPA's standardized emissions calculation
methods. States would be required to either (a) report annual emissions
and documentation, (b) provide comment on EPA-provided data, or (c)
accept EPA-provided data.
3. Nonpoint Sources Reported by States and Indian Tribes
The EPA intends to retain the current requirement for States to
report emissions for nonpoint sources for which the EPA does not have
emissions estimation tools. However, the EPA proposes to add a
documentation requirement for such sources, which is not included in
the current AERR. Consistent with the current rule, this proposed
requirement would be limited to CAP emissions, but States may also
voluntarily submit HAP emissions for these sources.
Regarding how States and Indian tribes should report nonpoint
sources, the EPA proposes to add a requirement for States to include
total activity input \5\ (including Indian country) when reporting
nonpoint data unless a State determines that an Indian tribe reports
nonpoint tool inputs for Indian country that overlaps with a State's
counties. In the latter case, the EPA proposes that a State would
exclude the activity and/or emissions within Indian country from the
county total data reported to avoid double counting. The EPA also
proposes to add a requirement that any Indian tribe that reports
nonpoint tool inputs and/or emissions for nonpoint sources would report
that data separately for

[[Page 54126]]

each county that overlaps the tribe's Indian country.
---------------------------------------------------------------------------

\5\ Activity data varies depending on the emissions calculation
approach and, therefore, the emissions source. Examples of nonpoint
activity data include solvent usage for printing, number and type of
wells for oil and gas production, vehicle miles traveled for road
dust, and fuel consumption for nonpoint industrial, commercial, and
institutional boilers.
---------------------------------------------------------------------------

C. Wildland Fires

The EPA proposes to require States \6\ to report activity data for
certain prescribed fires on State, certain tribal land (i.e., for
tribes with TAS), private, or military lands for the purpose of data
quality and completeness, specifically excluding prescribed fires that
occur on non-military Federal lands. Non-military Federal lands are not
included in this requirement due to the public availability of
prescribed burn activity data and based on continuing discussions at
the Congressionally mandated Wildland Fire Mitigation and Management
Commission and Wildland Fire Leadership Council which are developing
approaches for greater prescribed fire activity data tracking
systems.\7\ States would report fire activity data (e.g., acres burned)
on a day-specific basis for each broadcast and understory burn
affecting 50 acres or more. Similarly, States would report prescribed
fire activity data for a pile burn affecting 25 acres or more,
including fires with both pile and broadcast or understory burning
activity. EPA is committed to helping communities and our Federal,
State, local, and tribal partners to manage the health impacts of smoke
from wildland fires including prescribed fires. EPA and these partners
view the use of prescribed fire as an important tool for reducing
wildfire risk and the severity of wildfires and wildfire smoke. This
proposal would help gather information needed to estimate emissions
from prescribed burning with a goal of improving the accuracy of
emissions estimates for these activities. The EPA also proposes to add
a requirement that, for the purposes of data reported to EPA, man-made
grassland fires are considered prescribed fires and not agricultural
fires, land clearance burns, or construction fires.
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\6\ ``States'' is previously defined in Section III of this
preamble to include delegated local agencies and certain tribes.
\7\ The Bipartisan Infrastructure Law provides funding for a
significant increase in fuels and wildfire preparedness on Federal,
Tribal, State, and private lands to reduce wildfire risk. As part of
the funding, effort is being made to develop more information of
prescribed fire use from these same entities.
---------------------------------------------------------------------------

Additionally, the EPA proposes to remove the requirement for States
to report data for agricultural fires, which would make such reporting
voluntary rather than mandatory. Furthermore, this action proposes that
if States voluntarily report agricultural fire emissions, States would
report that data as day-specific event sources rather than as annual/
county total nonpoint sources.

D. Mobile Sources

The proposed revisions would clarify how States other than
California can meet the current requirement to report onroad and
nonroad emissions model inputs by submitting only select inputs.
California would not be impacted by this proposed clarification because
this proposed action would retain the current requirement for
California (at 40 CFR 51.15(b)(3)) to submit emissions data from its
own mobile models rather than model inputs. This proposed action would
establish the following minimum model inputs to be reported: a county
database checklist, vehicle miles traveled, and vehicle population.
Additionally, the EPA proposes a list of other mobile model inputs that
States can optionally provide and proposes to remove certain inputs
from being submitted in any situation.
The EPA also proposes to add a requirement for California to
provide documentation regarding the onroad and nonroad emissions data
they submit, which would describe the inputs, modeling, post-processing
of data, and quality assurance performed by California to create the
emissions submitted to EPA.

E. Other Changes

The EPA proposes additional changes that impact all source
categories. First, this action proposes to add a definition of ``actual
emissions'' that would apply specifically to this subpart A of Part 51
(to the AERR). The proposed definition would clarify the relationship
between the term ``actual emissions'' and other emissions terms
including emissions from periods of startup, shutdown, and malfunction
(SSM). Second, this proposed action would provide language to better
address the relationship of the requirements of this subpart to the
requirements of the NO<INF>X</INF> SIP Call, Regional Haze
requirements, Ozone SIP Requirements Rules, and the PM<INF>2.5</INF>
SIP Requirements Rule.

IV. Proposed Revisions to Emissions Reporting Requirements

A. Emissions Data Collection of Hazardous Air Pollutants for Point
Sources

1. The EPA Needs HAP Emissions for Regulatory Purposes
The CAA HAP list includes organic and inorganic substances that
Congress identified as HAP in the 1990 CAA Amendments, which Congress
and EPA have revised by further legislation and administrative action.
These HAP are associated with a wide variety of adverse health effects,
including, but not limited to cancer, neurological effects,
reproductive effects, and developmental effects. See the Health Effects
Notebook for Hazardous Air Pollutants.\8\ As explained in this section,
HAP emissions data are used extensively throughout EPA's regulatory and
informational programs to protect public health and inform communities
of potential risks from these pollutants.
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\8\ U.S. EPA, Health Effects Notebook for Hazardous Air
Pollutants, <a href="https://www.epa.gov/haps/health-effects-notebook-hazardous-air-pollutants">https://www.epa.gov/haps/health-effects-notebook-hazardous-air-pollutants</a>.
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The EPA has significant evidence that the current voluntary
reporting program from States is insufficient to meet these needs, even
when augmented by air data collection under the TRI. This evidence is
provided by EPA's work to meet the requirements of CAA 112(f)(2) for
Residual Risk analysis and to promulgate numerous regulatory actions.
Historically, to ensure that the EPA had sufficient emissions data to
complete its work, some of these regulatory actions have required
extensive one-time data collection efforts. Such intermittent data
collections require affected entities to take additional time and incur
additional costs due to the often hurried, non-routine, nature of the
requests. Consistent with the Paperwork Reduction Act, each of these
data collections allows owners/operators to review a draft, comment on
it, and then they are ultimately required to comply with a one-off
collection. This sporadic approach results in owners/operators having
to re-engage in an ad-hoc process with new requirements and
instructions each time the EPA asks for information via the Federal
Register and otherwise; it's an unpredictable stop-and-go process that
requires a certain amount of ``start-up'' costs (time and resources)
from owners/operators to understand and respond to each new request
that may be quite different from the last.
Complete, predictable, and routine HAP reporting would
significantly lessen the need for these intermittent data collections,
thus reducing the burden to owners/operators to react to such
intermittent, one-off collections. EPA would have data about all of the
units, processes, release points, and controls at facilities and their
associated emissions, so that EPA would not need to implement future ad
hoc efforts to gather such information. The data collection proposed
here would allow owners/operators to streamline collection and
reporting by having a

[[Page 54127]]

consistent set of data to report routinely through a standardized
approach.
While this ongoing collection of emissions data may ultimately have
an overall higher burden on owners/operators as compared to sporadic
one-time requests, this burden is at least partially offset by the
reduction in intermittent, one-off collections. EPA would have data
about all of the units, processes, release points, and controls at
facilities and their associated emissions.
Further, the EPA predicts that the burden associated with the
collection requirements proposed here will lessen over time. The EPA
recognizes that, just like for one-time data collections, owners/
operators will incur a ``start-up'' cost of time and resources to
initially understand and comply with the revised AERR requirements.
However, as owners/operators continue to comply year after year, this
``start-up'' burden associated with compliance will diminish because
owners/operators will already know the regulations. When a standardized
data reporting requirement is known in advanced, it provides
respondents the opportunity to plan ahead to most efficiently use their
resources to obtain the information to provide in the report. This
diminishing effect does not occur with one-time collections where each
new collection re-triggers those ``start-up'' costs. The EPA predicts
that the AERR approach will be more efficient in the long run. Lastly,
even if the approach proposed here imposes a burden that is
comparatively higher than an approach of continuous one-time
collections, the EPA finds that the incremental burden is justified by
all the benefits associated with this proposal that one-time
collections do not afford.
In addition to the reviews required under CAA 112(f)(2), CAA
112(d)(6) requires that the EPA must complete technology reviews every
8 years for the source categories regulated under CAA 112. Having
current HAP emissions data to support this ongoing technology review
requirement will facilitate future technology reviews, including both
(a) reviewing and, if appropriate, revising the current standards for
HAP that are regulated from the source category and (b) establishing
standards for any unregulated HAP emissions, as required under the
decision in Louisiana Environmental Action Network v. EPA, 955 F3d 1088
(D.C. Cir 2020) (``LEAN''). The LEAN decision clarified EPA's
obligation to set standards for all HAP emitted from all emissions
points for each category of major sources when EPA conducts a
technology review and identifies a pollutant for which no MACT standard
had been set.
Further, the EPA Office of Inspector General (OIG) has identified
that EPA has inadequate emissions data and is late on RTR assessments.
In its 2007 report, ``Improvements in Air Toxics Emissions Data Needed
to Conduct Residual Risk Assessments,'' \9\ OIG recommended that EPA
``establish requirements for State reporting of air toxics emissions
data and compliance monitoring information.'' In its report, OIG also
indicated that EPA's planned activities in response to the OIG report
``do not sufficiently address the problems identified, and we consider
the issues unresolved.'' More recently, in 2022, OIG issued the report
``The EPA Needs to Develop a Strategy to Complete Overdue Residual Risk
and Technology Reviews and to meet the Statutory Deadlines for Upcoming
Reviews.'' \10\ While this report focuses on the time it takes for EPA
to complete a review, rather than availability of emissions data, it is
clear from the timetable for conducting these reviews included in the
report that collecting emissions data is a limiting factor. The
timeline provided shows that the time to ``collect supplemental
information'' is between 0 to 28 months. This supplemental information
includes identifying the facilities associated with a source category
and collecting their emissions inventory data. The data that EPA
proposes to collect here would help address the findings of both OIG
reports.
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\9\ U.S. EPA Office of Inspector General, ``Improvements in Air
Toxics Emissions Data Needed to Conduct Residual Risk Assessments,''
Report No. 08-P-0020, October 31. 2007, <a href="https://www.epa.gov/office-inspector-general/report-improvements-air-toxics-emissions-data-needed-conduct-residual-risk">https://www.epa.gov/office-inspector-general/report-improvements-air-toxics-emissions-data-needed-conduct-residual-risk</a>.
\10\ U.S. EPA Office of Inspector General, ``The EPA Needs to
Develop a Strategy to Complete Overdue Residual Risk and Technology
Reviews and to Meet the Statutory Deadlines for Upcoming Reviews,''
Report No. 22-E-0026, March 30, 2022, <a href="https://www.epa.gov/office-inspector-general/report-epa-needs-develop-strategy-complete-overdue-residual-risk-and-0">https://www.epa.gov/office-inspector-general/report-epa-needs-develop-strategy-complete-overdue-residual-risk-and-0</a>.
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Under CAA 112(c)(5), the EPA has the authority to review the list
of section 112 source categories and list new source categories and
subcategories according to the statutory criteria. More current and
extensive HAP emissions data would allow the EPA to better identify
additional source categories and subcategories for listing.
Furthermore, once a new HAP is listed, the EPA would need information
about which sources are emitting it in order to develop and/or review
regulations to address the additional HAP.
Executive Order (E.O.) 12898 (59 FR 7629, February 16, 1994)
directs Federal agencies, to the greatest extent practicable and
permitted by law, to make environmental justice part of their mission
by identifying and addressing, as appropriate, the disproportionately
high and adverse human health or environmental effects of their
programs, policies, and activities on minority populations (people of
color) and low-income populations. Part of the impact of EPA's
regulatory actions on communities is to improve air quality by reducing
emissions of HAP and other pollutants with local impacts. Under the
current voluntary HAP emissions reporting program, some States submit
extensive HAP data, while other States submit few or no HAP data. While
the TRI air data provide some additional information on the HAP
emitted, the facility-level resolution does not provide quantitative or
qualitative details about the types of stack and fugitive releases and
respective emissions totals necessary for accurate risk modeling. Thus,
analysis quality suffers in communities without detailed data. EPA's
proposal to collect these data would help to close the gap in
understanding impacts of HAP and other pollutants on communities and
will therefore assist the EPA with fulfilling the goals of Executive
Order 12898.
2. The EPA Needs HAP Emissions for Risk Assessment
To be able to assess risks, the EPA develops information about
pollutant toxicity and characterizes pollutant hazards under the IRIS
program. Given the huge number of chemicals released to the air, it is
necessary to prioritize which pollutants are investigated by the IRIS
program. OAR uses information on emissions and exposures to help inform
priorities for IRIS nominations, which requires detailed HAP data and
release parameters that are not sufficiently available under the
current voluntary program.
The EPA has developed nationwide risk information for all
pollutants with the National Air Toxics Assessment (NATA) program. NATA
has been available approximately every 3 years since 2002 (starting
with the 1996 inventory year) and has been cited in countless
publications. More recently, as part of the air toxics strategy of the
Office of Air Quality Planning and Standards (OAQPS), the NATA program
has been replaced and enhanced by EPA's new AirToxScreen,\11\ which
will provide annually updated risk and emissions information for use by
EPA, States, and the public. AirToxScreen

[[Page 54128]]

supports more efficient implementation of numerous other programs and
provides risk information for communities through EJSCREEN and an EPA
website. As highlighted in the ``Our Nation's Air'' 2022 Trends
Report,\12\ identifying areas of concern impacted by air toxics
emissions is critical to EPA's mission to protect human health and the
environment and that sharing the latest air toxics emissions data and
risk are part of this effort. When EPA has more complete, current, and
high-quality emissions data, this supports improved completeness and
quality of this risk information.
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\11\ U.S. EPA Air Toxics Screening Assessment, <a href="https://www.epa.gov/AirToxScreen">https://www.epa.gov/AirToxScreen</a>.
\12\ U.S. EPA Our Nation's Air Trends though 2021, <a href="https://gispub.epa.gov/air/trendsreport/2022/#home">https://gispub.epa.gov/air/trendsreport/2022/#home</a>.
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For compliance purposes, EPA also uses the raw emissions data to
confirm that facilities are in the proper regulatory category to ensure
that their inspection frequency is correctly matched to their emissions
footprint. EPA staff compares NEI data to ambient data from nearby air
monitors to find discrepancies between the two. If a monitor is picking
up high pollutant concentration levels for a HAP and no nearby
facilities are reporting emissions of that HAP, EPA may find a
reporting issue or illegal manufacturing and follow up with an
inspection. EPA inspectors can search the EPA's Enforcement and
Compliance History Online (ECHO) database \13\ (that includes NEI data)
by emissions processes to help identify facilities of interest by
industry. EPA also uses AirToxScreen and its predecessor NATA for
prioritization of compliance and enforcement resources. Within EPA,
compliance staff have access to the ECHO Clean Air Tracking Tool
(ECATT), which includes data from many sources including AirToxScreen.
This tool integrates several data sources to facilitate analysis,
including searching for facilities based on cancer risk and respiratory
hazard index. Likewise, the EPA regional offices and States use risk
data to determine communities and facilities for review. The current
voluntary HAP data collection approach has provided some of the
information needed for this evaluation; however, a more comprehensive
HAP emissions collection program would further enhance the
prioritization by supporting more complete and more detailed risk and
emissions data than are currently available.
---------------------------------------------------------------------------

\13\ EPA Enforcement and Compliance History Online (ECHO),
<a href="https://echo.epa.gov/">https://echo.epa.gov/</a>.
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Another use of risk information enabled by HAP emissions data is
the siting of ambient monitors. HAP emissions and risk data are used by
the EPA and States to prioritize ambient monitor locations. These
ambient monitors in turn inform communities about air quality in their
local areas as well as support the evaluation of models that further
improve available information to EPA, States, and communities.
In addition to supporting risk assessments, the data that EPA is
proposing to collect provides foundational information about air
emissions for other purposes across the government. For example,
collecting data on air pollutants that are known cancer drivers will
advance core public health goals, including the President's Cancer
Moonshot Initiative which has the goal of preventing cancer through
reducing environmental exposures to carcinogens.
3. The EPA Needs HAP Emissions for Air Quality Modeling
HAP emissions data not only inform the regulatory and programmatic
activities dealing primarily with these pollutants, but also provide
benefits to modeling needs for implementation of the NAAQS. Under CAA
sections 110, 172, 182(b) through (e), and 189(a) and (b), the EPA and
States have requirements to use air quality modeling to help bring into
attainment nonattainment areas that violate the NAAQS ambient air
pollutant thresholds. Increasingly, the science suggests that some HAP
play important roles in air chemistry leading to formation of ozone and
secondary organic aerosol (SOA), a component of PM<INF>2.5</INF>.\14\
For example, HAP such as formaldehyde, acetaldehyde, 1,3-butadiene,
naphthalene, and chlorine contribute to ozone formation while other HAP
such as toluene, xylenes, benzene, and ethyl benzene are important for
SOA formation. In addition, some lower volatility or semi-volatile
compounds that contribute to SOA formation are HAP, such as naphthalene
and benzo(a)pyrene. Having more complete HAP data will be beneficial to
improving modeling and understanding of ozone and PM<INF>2.5</INF>
concentrations and SOA formation. The HAP data can provide the
additional details needed to improve air quality modeling needed for
NAAQS purposes.
---------------------------------------------------------------------------

\14\ Carter, W. Updated Maximum Incremental Reactivity Scale and
Hydrocarbon Bin Reactivities for Regulatory Applications, College of
Engineering Center for Environmental Research and Technology,
University of California, Riverside, January 28, 20210.
Ng, N.L., Kroll, J.H., Chan, A.W.H., Chhabra, P.S., Flagan,
R.C., and Seinfeld, J.H.: Secondary organic aerosol formation from
m-xylene, toluene, and benzene, Atmos. Chem. Phys., 7, 3909-3922,
<a href="https://doi.org/10.5194/acp-7-3909-2007">https://doi.org/10.5194/acp-7-3909-2007</a>, 2007.
Chan, A.W.H., Kautzman, K.E., Chhabra, P.S., Surratt, J.D.,
Chan, M.N., Crounse, J.D., K[uuml]rten, A., Wennberg, P.O., Flagan,
R.C., and Seinfeld, J.H.: Secondary organic aerosol formation from
photooxidation of naphthalene and alkylnaphthalenes: implications
for oxidation of intermediate volatility organic compounds (IVOCs),
Atmos. Chem. Phys., 9, 3049-3060, <a href="https://doi.org/10.5194/acp-9-3049-2009">https://doi.org/10.5194/acp-9-3049-2009</a>, 2009.
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As part of NAAQS implementation, the CAA specifically identifies
VOCs as a precursor to ozone, and VOC is additionally a precursor to
PM<INF>2.5.</INF> Thus, emissions and anticipated reductions of VOC are
inputs used for certain air quality modeling. VOC is a large group of
individual compounds, some of which are HAP and knowledge of those
detailed HAP compounds can be beneficial to air quality models that
rely on the components of VOC for model chemistry. Currently, the EPA
and States must make assumptions about the composition of VOC for each
source using other data called speciation profiles, which are costly to
collect, are not available for each source type, and can become
outdated quickly as new technologies and industrial chemical
formulations are used. In addition, new photochemical modeling chemical
mechanisms are being developed that provide better resolution to HAP
species. For example, the Community Regional Atmospheric Chemistry
Multiphase Mechanism (CRACMM) explicitly simulates 1,3-butadiene and
toluene and can also represent polycyclic organic matter and xylenes
better than prior, commonly used chemical mechanisms. While the use of
speciation profiles is useful, VOC speciation for modeling could be
significantly improved with complete and accurate HAP emissions that
provide details about the component VOC HAP.
As with VOCs, PM<INF>2.5</INF> is a NAAQS pollutant and is
currently collected from States by the AERR. PM<INF>2.5</INF> is also a
large group of individual compounds, some of which are HAP. Individual
HAP metals are included in this group, and some of these metals are
required specifically in the most recent chemical formulations used in
air quality models. In addition, as with VOCs, having more detail about
PM<INF>2.5</INF> components would allow for increased confidence in
EPA's air quality modeling results.
The EPA estimates costs and benefits as part of Regulatory Impact
Analyses (RIAs) for rulemaking to support implementation of Executive
Order 12866. That benefit analysis can include the ancillary benefits
of HAP reductions, even when regulations are specific to NAAQS
implementation. For

[[Page 54129]]

example, the RIA accompanying the revision of an ambient standard and
revisions to national mobile source standards can describe ancillary
benefits of HAP reductions, even when those regulations are being put
in place to reduce VOC or PM<INF>2.5</INF> emissions. A complete and
integrated HAP emissions inventory would enhance EPA's ability to
estimate the ancillary benefits of HAP reductions, and thereby help
lead to better informed decision-making.
4. Proposed HAP Reporting Requirements
In previous rulemakings, the EPA has considered, but never
finalized, mandatory HAP reporting to collect emissions inventories. On
May 23, 2000, the EPA proposed to collect HAP emissions data (CERR; 65
FR 33268). However, the CERR proposed rule did not specify any details
about how the EPA would collect that data, or even which pollutants the
EPA would require to be reported. The EPA did not finalize any
mandatory reporting for HAP due to comments received on the proposed
rule arguing that ``EPA should not include HAP reporting requirements
in the final rule until the specific HAP reporting requirements were
proposed'' (67 FR 39602, June 10, 2002).
In response to the original AERR proposed rule (71 FR 69; January
2, 2006), several commenters encouraged the EPA to include a specific
requirement in the rule for reporting HAP emissions data for title V
facilities. Another commenter encouraged the EPA to include
requirements for reporting of HAP from all emission sources. One
commenter noted that States were attempting to provide HAP data to the
EPA by relying on data collected from facilities largely on a voluntary
basis, and that collection would improve if the EPA required HAP
reporting. However, the EPA did not include HAP in the final AERR rule
at that time. The EPA cited the existing voluntary program, stating
that we believed it would be possible to continue developing and
improving national level HAP inventories using a voluntary approach. We
also explained that we intended to closely monitor the participation of
State agencies in this effort and that, should the need arise, we would
revisit the issue.
Furthermore, while the EPA has numerous regulations on industrial
facilities through the National Emission Standards for Hazardous Air
Pollutants (NESHAP) and other similar standards, these regulations do
not typically require the reporting emissions of annual HAP. Rather,
they largely require reporting of compliance information such as stack
test results. In many cases, these stack tests are not required to be
tests for HAP but instead can be tests of a surrogate pollutant such as
filterable PM<INF>2.5</INF>. The result of the test does not estimate
annual emissions but rather provides an emission rate of one or more
pollutants from the source. As a result, even for these well-regulated
industries, the EPA lacks annual HAP except when it is voluntarily
reported or collected for the TRI.
With this action, the EPA is proposing to require the reporting of
HAP from point sources, as defined by the AERR, which can be both major
sources and non-major sources. For purposes of the AERR, certain non-
major sources can be point sources that would be subject to the
proposed reporting requirements. These can include CAA section
112(c)(3) area sources and sources that do not have a source category
listing. Non-major sources would need to emit at or above the proposed
thresholds in order to be subject to these proposed reporting
requirements. For CAP and HAP major sources, the EPA proposes a
requirement to report all HAP, which is defined by pollutants listed in
CAA 112(b)(1), 42 U.S.C. 7412(b)(1) and 40 CFR 63.64(a). The EPA also
proposes a requirement to report certain HAP from non-major sources
\15\ when annual actual emissions exceed a reporting threshold
promulgated by the Agency (as described in section IV.A.8 of this
preamble and as listed in the proposed Table 1B to Appendix A of
Subpart A). In addition to these requirements, this proposal includes
maintaining the current voluntary pollutant reporting by States and
industry for additional facilities and/or additional HAP for non-major
sources and voluntary GHG reporting by States. Finally, while the
proposal for mandatory HAP reporting is organized within the AERR
structure for convenience and to limit burden via streamlining, the HAP
reporting requirements are able to stand on their own separate from the
CAP reporting requirements.
---------------------------------------------------------------------------

\15\ Non-major sources are stationary sources that do not meet
the major source thresholds for criteria pollutants and HAP. Major
sources require Title V permits. Criteria for these sources are
provided at <a href="https://www.epa.gov/title-v-operating-permits/who-has-obtain-title-v-permit">https://www.epa.gov/title-v-operating-permits/who-has-obtain-title-v-permit</a>.
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Requirements for HAP reporting are being proposed for two
overarching reasons in addition to the other reasons discussed
throughout this notice. First, the EPA has monitored the collection and
reporting of HAP information from States and has found that the
voluntary approach has not sufficiently provided the EPA with the point
source HAP data it needs. States report to the EPA between 1 and 148
HAP per year from point sources. This proposed action would collect
information on all 188 HAP from major sources and significant emissions
of HAP from non-major sources. Collecting information on all HAP from
major sources supports requirements of CAA section 112, which includes
a definition at CAA 112(a)(1) of major HAP sources based on total HAP
emissions, and which directs EPA at CAA 112(d)(1) to promulgate
regulations establishing emission standards that CAA 112(d)(2) requires
the maximum degree of reduction in emissions for all of the HAP subject
to section 112 of the Act that are emitted from source categories of
major sources.
For the 2017 NEI,\16\ 76 out of 85 State/local/tribal agencies
reported point source HAP to EPA. These 76 agencies reported an average
of 79 such pollutants. The EPA has found these voluntary reports to be
insufficient and, therefore, they have been unable to meet EPA's needs
for implementing CAA section 112. Because the section 112 regulatory
work requires the most detailed HAP emissions data, we can reasonably
conclude that the data for other HAP analysis products and needs
described above are similarly incomplete. While the EPA has
increasingly used TRI air emissions data to help fill reporting gaps
for some uses of the NEI (e.g., national totals), these data do not
have the sufficient detail necessary for detailed risk modeling and
other assessment needs previously described.
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\16\ U.S. EPA, 2017 National Emissions Inventory, <a href="https://www.epa.gov/air-emissions-inventories/2017-national-emissions-inventory-nei-data">https://www.epa.gov/air-emissions-inventories/2017-national-emissions-inventory-nei-data</a>.
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Second, the EPA now has a proven infrastructure through CAERS to
support centralized collection of detailed emissions data from
facilities and to provide flexibility in reporting from either
facilities or States. CAERS can implement the requirements of this
proposed rule without undue burden on facilities or States by: (1)
avoiding duplicative reporting requirements, (2) supporting consistency
of data across programs, and (3) supporting States, locals, and Indian
tribes that collect HAP data.
Using CAERS, the EPA is currently working to connect the CEDRI
source test data collection with the estimation of emissions data
included in this proposal. This proposal does not require any new
monitoring or source testing, rather the EPA is proposing that owners/
operators use the ``best available'' estimation techniques (see section
IV.I.6 of this preamble for more details). Through planned CAERS

[[Page 54130]]

enhancements, owners/operators would be able to pull in their source
test data more easily, to facilitate this approach for using the best
available data to estimate emissions. If a source is already required
to report compliance information, such as stack testing, due to an
existing requirement separate from the AERR, such as a NESHAP, then
this proposal is that the owner/operator would use that existing
information, if appropriate, for purposes of estimating annual
emissions reported under the AERR. Similarly, if the source already
generates certain data for the TRI, then EPA is proposing that the
source utilize that existing data for purposes of the AERR.
5. Collecting HAP Annual Emissions
Based on the numerous needs for HAP data described above, the EPA
is considering how to obtain the HAP emissions data that the Agency
needs to carry out the requirements of the CAA, while also seeking to
minimize burden on States, by investigating whether HAP emissions
should be reported by States, by owners/operators of facilities, or by
some combination. The EPA's primary proposal would use a combined
approach for reporting HAP emissions. First, this action proposes that
owners/operators of facilities would be required to report facility
inventory data and HAP emissions directly to the EPA via CAERS. This
proposed approach would include reporting by facilities both within
States and within Indian country. Second, this action proposes an
option that would allow a State to report HAP data to the EPA on behalf
of the owners/operators of facilities in the State. However, to
implement this option, the EPA also proposes that States choosing to
report HAP emissions on behalf of sources would be required to receive
EPA approval for State regulations that implement HAP reporting
requirements. For a State to receive approval, State regulations would
need to meet any finalized requirements based on this proposed action
(e.g., by reporting at least the same information from the same sources
on the schedule required for owners/operators). State regulations could
include additional HAP reporting requirements that exceed the EPA
requirements. Additional details on the approach for transfer of
responsibility from owners/operators to States is proposed below.
The current AERR supports voluntary reporting of HAP by States. To
date, the EPA has observed the benefit of State oversight given the
States' authority to issue and manage permits and associated emissions
limits. The EPA also recognizes the additional burden that would be
placed on States if they were required to report HAP, especially for
those States that are not already requiring such reporting from
sources. Further, States that are already collecting HAP data may need
to revise their current reporting rules and/or develop new collection
mechanisms for HAP if their current programs are not meeting any final
HAP reporting requirements that are promulgated in this rulemaking.
This burden could include managing reports from more facilities,
maintaining more data, and implementing a more complex annual
collection process than a program that requires CAPs alone. The EPA
recognizes that States will have differing capacities to include HAP
emissions collection as an additional responsibility.
In formulating this proposal, the EPA is considering the
significant differences between CAA Part D, with many emission data
provisions required of States, as compared to other provisions in CAA
Part A under which the EPA has regulated HAP. The current AERR requires
emissions reporting only for CAPs but does not specifically include a
requirement for States to have reporting rules in place. This is
because for CAPs, the CAA has set up a coregulator paradigm by which
State emissions reporting rules are reviewed and approved by the EPA as
part of infrastructure and other SIPs. In this way, the EPA can ensure
that State regulations meet the various emissions reporting
requirements of the AERR. The CAA does not provide a similar paradigm
for HAP emissions data collection. Thus, EPA's proposed solution
addresses these differences to provide an implementation that aligns
with the Act.
Another consideration is the available technical methods by which
the EPA can gather data from States and/or from owners/operators. Under
the current AERR, States submit data through the Central Data Exchange
(CDX) to the Emissions Inventory System (EIS), and that approach is
expected to continue under this proposed action. In addition, the EPA
and States have developed CAERS as one approach for supporting State
collection of emissions in a way that can reduce the burden on some
owners/operators of facilities for shared reporting of emissions to the
TRI program.
The EPA is considering that some owners/operators of facilities are
already obligated to report HAP to the TRI, though with less detail
than is needed by the EPA for risk assessment and other purposes cited
in this proposal. Because CAERS offers owners/operators a means to
report air emissions to States, NEI, and TRI, EPA's experience leads
the Agency to anticipate that CAERS would ultimately lessen the
reporting burden on owners/operators. The EPA is aware that facility
definitions occasionally differ among the TRI program, the NEI, and the
State programs. Ongoing work by the EPA is expected to address the
challenges posed by differing facility definitions across emissions
collection programs, which is related to the Cross-Program Identifiers
Option described in section IV.I.17 of this preamble.
The EPA is also considering that there are numerous State HAP
emissions collection programs with differing requirements. Comparing
such programs reveals that they collect different data fields, have
different emissions reporting thresholds, and collect different
pollutants. Companies that operate facilities in multiple States and
report emissions data from a central part of the company could have to
comply with numerous different requirements depending on the State.
Additionally, the EPA is considering that owners/operators would face
additional challenges if a State required owners/operators to report
HAP, but the State requirements did not match EPA requirements. In this
case, owners/operators could be faced with the burden to report
differently both to the State and to EPA. Indeed, this situation
already exists with respect to State HAP requirements and EPA
requirements for TRI reporting.
By proposing CAERS as the reporting system for owners/operators of
facilities, the EPA also provides States a choice about the degree to
which the State will take on additional burden. States may choose to
participate voluntarily in review of HAP data provided by owners/
operators to the EPA rather than implement their own reporting
requirements. States may alternatively choose to implement HAP
reporting regulations that match (or go beyond) EPA's requirements.
This proposed action does not eliminate the possibility that
industry may face a duplicative reporting requirement for the State.
States are free to use a data collection approach of their choice and
implement regulations that meet State needs. For example, if a State
chooses for owners/operators of facilities to continue to report to a
State system and those facilities are also required to report HAP to
the EPA via CAERS, then duplication could exist. This duplication could
take the form of requiring the same HAP emissions data be reported via
two separate collection

[[Page 54131]]

mechanisms to both the State and to EPA. This proposal provides
mechanisms to avoid duplicative reporting requirements, but the Agency
is aware that it may not completely eliminate the possibility of
duplicative requirements because it provides States choices in how they
comply with the proposed requirements. The EPA seeks comments on how we
might reduce or eliminate the possibility of duplicative requirements.
While CAERS provides a way to help eliminate the possibility of
duplicative burden on owners/operators, the EPA is not proposing to
require that CAERs be used by States at this time. To avoid duplicative
reporting burden for the owners/operators of facilities for which the
associated State is collecting HAP emissions, a State would need to
choose to participate in CAERS using one of the supported approaches.
First, a State may choose to have owners/operators report data through
CAERS to the EPA and then use CAERS to review and/or transfer the data
to the State's own data system. Second, a State may choose to work with
the EPA to build a direct connection between the State's data system
and CAERS, so that data transfers can happen even more easily. Third, a
State may choose to adopt CAERS as their emissions data reporting
system.
The EPA is considering the additional complexity that would be
created under a requirement in which owners/operators reported HAP
directly to the EPA while States reported CAPs to EPA. Furthermore, the
EPA expects additional complexity because some State requirements
would, as they do under the current AERR, collect more facilities and/
or pollutants than EPA requirements that may be finalized under this
proposed action. To be able to support this complexity, CAERS would
share the ``facility inventory'' among EPA, States, and owners/
operators to provide the collection of facilities and their components
for which emissions are reported. These components include units,
processes, release points, control devices and associated
identification codes and parameters. The EPA is aware that often the
identification codes for the components of the facility inventory are
different between the State and the facility reporting the data. Thus,
the EPA and State implementation of any finalized data collection
approach would consider and address these challenges. The EPA requests
comments that offer suggested approaches for sharing facility inventory
data between the EPA and States.
The EPA is considering whether it would be feasible to allow States
to report only some of the required HAP, while sources retain the
obligation to report the remaining HAP. EPA's experience suggests that
such an approach would be too complicated to implement because it would
require EPA and States to track reporting responsibility individually
for the hundreds of required pollutants. The approach proposed by the
EPA provides for a simpler tracking approach with just two categories
of pollutants: ``CAP'' and ``HAP.'' This straightforward approach helps
ensure that the EPA and States will know whether the State or owner/
operator is expected to report HAP for a given facility and inventory
year. The approach also allows the EPA to administer the reporting
program more robustly, including assessing completeness of data
submissions and compliance with the proposed requirements. This
proposed approach also makes it easier for owners/operators and States
to know which party is responsible for reporting each pollutant to EPA.
The current AERR includes voluntary reporting of HAP, air toxics,
and greenhouse gases. As just described, the EPA proposes that the HAP
reporting would become mandatory under any final version of this
proposed action and proposes to retain voluntary reporting by States as
an option in other cases. For example, States would be able to continue
to report any pollutant for facilities not required to report for HAP
under any final action. Additionally, for any point sources, States
would be able to report any other pollutant not required by any final
version of this proposed action, such as other air toxics that are not
HAP (e.g., Tert-butyl Acetate) and greenhouse gases, provided that the
pollutant is supported by EPA's electronic collection approach.
In addition to the proposed policies just described, the EPA is
considering an alternative (Alternative A1) that would not collect data
directly from owners/operators of facilities within the geographic
scope of a State's implementation planning authority but would only
collect such data from States. Such an approach would reduce
complexity, but also would not provide States flexibility in their
implementation approach and would cause additional burden for all
States if the EPA finalizes mandatory HAP reporting. To implement such
an option, the EPA would change the proposed regulation as follows:
remove owner/operator requirements of proposed Sec. 51.25(a), remove
the HAP reporting application of proposed Sec. 51.1(d), and modify
proposed Sec. 51.15(a)(2) to eliminate the qualifier ``if the EPA has
approved a HAP reporting application as per Sec. 51.1(d)(2) of this
subpart.'' The EPA requests that commenters provide input on
Alternative A1.
In addition, the EPA is considering a second alterative
(Alternative A2) of relying only on owner/operator reporting for HAP
and not including an option for States to report on behalf of owners/
operators. The existing state-reporting paradigm in the current AERR is
a valuable approach that would continue under this alternative for CAPs
to ensure the collection and sharing of data needed for NAAQS
implementation under CAA Part D. For HAP, the EPA recognizes the
benefit of States' roles in collection of HAP emissions and, for that
reason, has proposed to include State reporting as an option. To
implement Alternative A2, the EPA would remove the HAP reporting
application of the proposed Sec. 51.1(d) and remove the proposed Sec.
51.15(a)(2). In addition, under this alternative, States would continue
to report Pb for point sources meeting any of the CAP emissions
reporting thresholds (including Pb), while owners/operators would
report Pb for other sources that do not meet the CAP Pb reporting
threshold but are otherwise subject to the proposed Pb reporting
requirements as a HAP.
Because the primary proposed approach would require owners/
operators to report to the EPA using CAERS, the EPA anticipates that
some States will choose to participate in the CAERS program. In
addition, the EPA has already received notifications from States of
their intent to adopt CAERS in some form, and the EPA recognizes a need
for managing that process so that the EPA and States will have
sufficient time to transition to CAERS in advance of emissions data
collection. To address these considerations, the EPA proposes that
States voluntarily adopting one of the CAERS workflows notify the EPA
within 2 months before the beginning of the first inventory year for
which a State intends to use the CAERS workflow. For example, for the
2024 inventory year, a State would notify the EPA by November 1, 2023.
This timing would allow the EPA and the State about 16 months to
integrate the States' needs and data to CAERS in preparation for the
start of the CAERS reporting period for that inventory year by February
of the year after the inventory year.\17\ For

[[Page 54132]]

example, for the 2024 inventory year, the EPA would make available
CAERS no later than February 28, 2025, for owners/operators to report
emissions data. While such a notification is included in the proposed
rule as a recommendation (i.e., ``should'') rather than a requirement,
if a State does not notify the EPA in advance of that date, the EPA may
not be able to accommodate the State for CAERS use until the following
inventory year.
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\17\ The availability of each CAERS release to date has been
during February of each year, with CAERS opening for reporting for
the 2022 inventory year on February 6, 2023.
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6. State Application for Voluntary HAP Reporting Responsibility
With HAP emissions reporting by either owners/operators or by
States for a particular inventory year, it is necessary that this
proposed action include provisions to ensure that EPA, States, and
owners/operators all know which party is expected to report HAP
emissions to EPA. Under this proposal, a State could choose to report
for all owners/operators within the State who would have to report HAP.
This proposed approach allows for States that already report HAP to
continue to do so, but also avoids a burden increase for other States
while making CAERS available to further reduce burden for States
reporting HAP.
A clear and documented transfer of responsibility from owners/
operators to a State is necessary when a State elects to report HAP,
and the EPA is considering how best to ensure that the State
regulations provide an adequate substitute for its own requirements in
this situation. Similarly, this proposed action includes an approach to
transfer responsibility from a State back to sources in the event a
State no longer meets the requirements or intends to stop reporting on
behalf of owners/operators.
The EPA is considering how States should document their intent to
meet this proposed action's HAP reporting requirements. One approach
under consideration could be to have States simply notify the EPA of
their intent, and if the State did not fulfill a reporting requirement,
require the facility to report any missing data to EPA. This approach
has the benefit of more flexibility, but implementation would be very
challenging because it would not be clear which party would be
obligated to report which data. Further, turning to owners/operators to
report when States have missed the requirement would delay the data
transmission to EPA.
To provide the EPA with evidence of a State's intent and to ensure
a clear transfer of responsibility from an owner/operator to a State,
the EPA proposes to require that a State choosing to report on behalf
of its owners/operators adopt EPA's requirements, or the equivalent,
into the State's regulations. This proposed action also specifies the
process for the transfer to occur, including State submittal of its HAP
emission collection program to the EPA for approval. When a State
submits its program, the submittal would reference the State regulation
and explain how it meets all provisions of EPA HAP reporting
requirements. Without a sufficient State regulation, the EPA would not
be able to approve a State to report HAP emissions on behalf of owners/
operators. The EPA recognizes sufficient time is required for changes
to State regulations, which informs the proposal of 2026 as the first
inventory year that would require HAP reporting by owners/operators
within States.
The EPA proposes that the geographic scope of a State regulation
requiring HAP emissions data should be consistent with those lands
covered by the State's Infrastructure SIP (EPA understands this scope
to be synonymous with the relevant State's implementation planning
authority). This proposed approach stems from the current structure of
the AERR and this proposal's approach to continue States' reporting of
CAP emissions data for sources located within this geographic scope.
The intent is to create clarity regarding which parts of a State's
geographic boundaries would be included for HAP reporting by the State
under this proposal, and the EPA's understanding of the State's
authority would generally be the same for sources of CAP and HAP
emissions. Once a State is approved to report HAP emissions on behalf
of the owners/operators of facilities located within the geographic
scope of the State's implementation planning authority, then the State
becomes the responsible party for complying with the requirements of
the AERR for those sources; the EPA would no longer consider those
owners/operators to be the party responsible for compliance.
To formalize the transfer of responsibility for reporting after the
completion of the process described above, the EPA would issue a letter
to the State indicating that the State is approved to submit HAP
reports on behalf of owners/operators. Further, to provide a means for
owners/operators to determine whether their State has assumed the
responsibility for reporting, the EPA would post that letter on a
website that would be maintained for the purpose of communicating which
States are responsible to report HAP on behalf of owners/operators for
each inventory year.
The EPA additionally proposes to require a State seeking approval
to submit its HAP collection program to the EPA by March 31 of the
first inventory year for which the State intends to report emissions
(e.g., by March 31, 2026, for the 2026 inventory year). This timing is
designed to be at least one year in advance of the deadline proposed
for owners/operators to report emissions directly to EPA. It provides
sufficient time for the EPA to review the State application, the State
to revise the application if needed, and the EPA to act on the State
submittal. A State could still submit after this deadline but doing so
would likely mean that the transfer of authority would not happen in
time for the next reporting period. A delayed application would simply
delay when the State could start reporting if approved. Once the EPA
provides HAP reporting approval, the State would be obligated to
fulfill the HAP reporting requirements for subsequent inventory years.
While the EPA will make every effort to review applications in time for
the desired inventory reporting year, there is no guarantee that the
EPA will complete the review in time to meet the States' wishes.
The EPA would notify States as expeditiously as possible regarding
EPA's response to the State's application, any needed adjustments, and
post final decisions on the EPA Air Emissions Inventories website. This
website publication would ideally be made by December 15 of the
inventory year, but the date could be earlier or later than that
depending on circumstances. This target date is intended to provide
sufficient time for owners/operators to adjust plans and obtain
training for any new reporting systems. Since States start collecting
data within months of this date, the EPA expects States would have
already made updates to their data collection system to comply with
their new regulatory requirements in advance of this date in
anticipation of approval.
7. Review and Revisions to HAP Reporting Responsibility
The EPA proposes to require an EPA review of previously issued HAP
reporting approval when: (1) a State or the EPA revises emissions
reporting requirements for any emissions data element affecting HAP
(including the facility inventory); or (2) the EPA is made aware of any
discrepancies between EPA requirements and either (a) what a State
requires from facilities

[[Page 54133]]

or (b) what a State has reported or intends to report. A State or the
EPA could initiate a review by informing the other party that such a
review is necessary. Any revised submissions by a State on its HAP
collection program would need to meet the same March 31 deadline as for
initial applications. A review of a State HAP reporting program could
result in a revocation of approval to report.
The EPA proposes that HAP reporting approval for a State would
continue to apply for subsequent inventory years unless the EPA revokes
the reporting approval and transfers responsibility back to owners/
operators. As with reporting approval, this revocation would be made
via letter from the EPA to the state. The letter would be posted on the
same website previously described to document which entities have
reporting responsibility for which inventory years.
In addition, the EPA proposes an approach for how a State, having
previously been approved to report on behalf of owners/operators, could
elect to revert HAP data reporting back to owners/operators. To
initiate such a transfer, the EPA proposes that a State would need to
notify the EPA in writing no later than November 1st of the year before
the inventory year. For example, if the State intended for reporting to
revert to owners/operators for the 2027 inventory year, the State would
be required to notify the EPA by November 1, 2026. This timing would
allow the EPA sufficient time to update CAERS to incorporate the
additional owners/operators and their facilities. While the EPA will
make every effort to review requests to revert responsibility to
owners/operators in time for the desired inventory reporting year,
there is no guarantee that the EPA will complete the review in time to
meet the State's wishes. If approved by EPA, a request to revert
responsibility to owners/operators would result in a revocation letter
as described above.
8. Expansion of Point Source Definition To Include HAP
The current AERR defines point sources for reporting to the EPA by
States based on Table 1 to Appendix A of this subpart using PTE
reporting thresholds for CAPs. To implement collection of HAP
emissions, the EPA would need to determine criteria to specify which
facilities would need to be reported by States and owners/operators as
point sources for HAP. For the reasons discussed in this section, the
EPA is proposing at 40 CFR 51.50 to expand the AERR-specific definition
of point sources to ensure the appropriate facilities would be included
for HAP reporting purposes.
EPA first evaluated using the current AERR's CAP PTE reporting
thresholds to define point sources. The EPA is not proposing this
approach because there is no reasonable expectation that using these
reporting thresholds to define point sources for HAP reporting would
capture all sources with significant HAP emissions from a public health
perspective. Such an approach could result in an incomplete reporting
approach that would limit EPA's ability to obtain all needed HAP data.
For example, hexavalent chromium is a component of PM<INF>2.5</INF>, so
using the current AERR PTE threshold for PM<INF>2.5</INF> would result
in a 100 tons per year (tpy) PTE threshold for chromium. However,
hexavalent chromium has been shown to cause significant public health
risks at levels less than 100 pounds.\18\ Given this example and others
like it, using the current AERR emissions reporting thresholds would be
insufficient to fulfill the goals of this proposed action. By contrast,
the EPA expects that two remaining approaches would provide EPA
emissions data to support our public health mission: (1) collecting
data from all facilities emitting any level of HAP or (2) setting
specific HAP facility-wide emissions levels above which owners/
operators would need to report.
---------------------------------------------------------------------------

\18\ See Chromium Electroplating NESHAP rule: <a href="https://www.epa.gov/stationary-sources-air-pollution/chromium-electroplating-national-emission-standards-hazardous-air">https://www.epa.gov/stationary-sources-air-pollution/chromium-electroplating-national-emission-standards-hazardous-air</a> proposal
results (FR 65068, October 21, 2010), which found a maximum
individual risk of 70-in-1 million from 33 lbs of hexavalent
chromium emissions.
---------------------------------------------------------------------------

To evaluate the approach of collecting data from all facilities
emitting any level of HAP, the EPA considered the practical
implications of collecting HAP data from all sources, specifically
looking at the number of facilities that would be affected from certain
common activities based on the 2017 Economic Census.\19\ Some examples
of emissions sectors with many facilities that emit some level of HAP
include restaurants (583,400), gas stations (112,600), and automotive
repair and maintenance (162,000). Under the current AERR, EPA requires
reporting of about 12,400 facilities as point sources. Further, States
voluntarily submitted about 49,500 point sources for the 2017 NEI and
about 59,800 for the 2020 NEI. If EPA now proposed to collect emissions
from all facilities emitting any HAP, such a vast expansion could
overwhelm both the States' and the EPA's abilities to manage the
efforts effectively.
---------------------------------------------------------------------------

\19\ U.S. Census Bureau, 2017 SUSB Annual Data Tables by
Establishment Industry, <a href="https://www.census.gov/data/tables/2017/econ/susb/2017-susb-annual.html">https://www.census.gov/data/tables/2017/econ/susb/2017-susb-annual.html</a>, May 2021, Excel file
``us_state_naics_detailedsizes_2017.xlsx''.
---------------------------------------------------------------------------

Further, an expansion to all facilities emitting any level of any
HAP may cause undue burden on facilities that each emit a very small
amount of HAP. At this time, the EPA estimates emissions from such
sources as nonpoint sources on a county-wide basis. For example, for
gas stations, the EPA estimates nonpoint emissions using the MOVES
model for Stage II refueling from storage tanks to vehicles and data
consistent with MOVES for Stage I refueling from tankers to storage
tanks.\20\ For commercial cooking occurring at restaurants, EPA
purchases data about the number of restaurants in each county and uses
other data about food usage along with emission factors to estimate
emissions.
---------------------------------------------------------------------------

\20\ U.S. EPA, 2020 National Emissions Inventory, Technical
Support Document, March 2023, EPA Document number EPA-454/R-23-001,
<a href="https://www.epa.gov/air-emissions-inventories/2020-national-emissions-inventory-nei-technical-support-document-tsd">https://www.epa.gov/air-emissions-inventories/2020-national-emissions-inventory-nei-technical-support-document-tsd</a>.
---------------------------------------------------------------------------

Based on these examples, the EPA does not now intend to require all
emitters of HAP to report emissions at any level. In addition to the
burden on the many small establishments, EPA and State resources would
be diverted away from focusing on the more critical emitters due to the
sheer volume of owners/operators that could be required to report
without a more tailored approach. Such a tailored approach is
consistent with CAA section 112, which provides the EPA with
flexibility in setting requirements for area sources, which emit HAP at
less than major source levels. So, it is appropriate for the EPA to
consider how best to gather data about HAP emissions at those levels.
The EPA is proposing to set new reporting thresholds for HAP, above
which owners/operators of facilities would need to report emissions.
The EPA is considering the following factors in defining reporting
thresholds: (1) existing thresholds such as the major source definition
and reporting thresholds for the TRI; (2) which pollutants should be
reported; (3) the degree of human health impact on communities caused
by differences in toxicity of pollutants; and (4) a desire to focus
data collection efforts on facilities with the potential to cause
significant and ongoing impacts while avoiding less beneficial
reporting by many small, lower impact facilities. Each of these
considerations is described in the paragraphs below.
Factor 1: For existing thresholds, CAA section 112 provides the
definition of HAP major sources as the potential to

[[Page 54134]]

emit 10 tpy of any HAP or 25 tpy of any combination of HAP. The EPA
must also address emissions of all HAP in its actions to regulate major
sources. In addition, major sources are already well versed in the
regulatory requirements under which they operate, and many of these
sources also must report to the TRI program. For these reasons, a
logical and reasonable approach for a minimum requirement would be that
major sources would report all HAP to be consistent with the regulatory
programs and requirements that the EPA seeks to meet.
In addition to the emissions thresholds associated with the major
source definition, the EPA is considering reporting thresholds set with
the requirements for TRI. That program has reporting criteria based on
the number of full-time employees; primary NAICS; chemicals a facility
manufactures, processes, or otherwise uses; and activity levels. As a
result, the TRI reporting thresholds are not based on facility air
emissions; therefore, those thresholds have less relevance for this
proposed action. For many reasons including emissions controls that
reduce emissions, the amount of a HAP emitted to air is very different
from the amount manufactured, processed, or otherwise used by a
facility. For this reason, the TRI program's reporting thresholds are
not being proposed as the primary approach for setting reporting
thresholds for non-major sources under this subpart. A benefit to this
approach is that any data that would be collected under this action
would likely include sources not reporting to the TRI program and would
fill gaps in the agency's data collection.
Factor 2: The EPA also is considering which pollutants should be
reported. As previously described, a policy under which major sources
to report all HAP is most supportive of EPA's needs for HAP data. For
sources other than major sources (also known as ``area sources'' under
CAA section 112 and hereafter referred to as ``non-major'' sources),
the EPA is considering both whether to require air toxics \21\ other
than listed HAP and which HAP (or other) pollutants should be reported.
---------------------------------------------------------------------------

\21\ Although it has become common practice to use the terms
``air toxics'' and ``hazardous air pollutant'' interchangeably, air
toxics is a broad term that includes all compounds of some
recognized toxicity and is not limited to those HAP identified by
the CAA and EPA HAP listings. For example, a more extensive listing
of air toxics is included by TRI-listed chemicals, available via the
TRI website at <a href="https://www.epa.gov/toxics-release-inventory-tri-program/tri-listed-chemicals">https://www.epa.gov/toxics-release-inventory-tri-program/tri-listed-chemicals</a>.
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Regarding air toxics other than listed HAP, the EPA is considering
two possible approaches: (1) requiring air toxics that are already
required by States and (2) requiring air toxics that are required by
the TRI program. Either of these approaches would provide additional
detailed data for the EPA to analyze air toxic emissions in the context
of listing new HAP. Both approaches also would constrain reporting to
pollutants that are already being collected, which would have a lower
burden than other conceivable approaches. In the case of an approach
based on TRI air toxics (called chemicals by the TRI program),
additional burden beyond a State-based approach would be incurred by
owners/operators because those owners/operators are currently reporting
facility total data to TRI and would have to report more detailed data
to the NEI. On the other hand, if an owner/operator is already
reporting to TRI, then the incremental effort for such a facility is
lower when compared to a facility not reporting air toxics data at all,
because the aggregated information is currently collected and reported.
For the first approach (i.e., requiring States to report additional
air toxics that they already collect), the EPA observes that such data
are largely being submitted voluntarily under the current AERR.
Furthermore, since different States collect different air toxics, it
would be challenging for the EPA and owners/operators to keep track of
State requirements to ensure compliance with a Federal rule that relied
on State rules for defining what pollutants were required by that
State. In addition, EPA's need for other (non-HAP) air toxics data is
not currently as significant as the need for HAP data because the use
of the additional air toxics is largely limited to consideration of
listing new HAP. Also, this more limited need for the data is already
met to some degree by the facility total data from TRI and from
voluntary reporting by some States. Based on these considerations, the
EPA is not proposing to use State requirements to set the required
pollutants for reporting by owners/operators (i.e., beyond the HAP
proposed for collection).
EPA is also considering using the required TRI chemicals to
determine which pollutants should be reported under the AERR. As
described above, this proposed action envisions that States could apply
for approval to report HAP on behalf of the owners/operators of
facilities who would otherwise report emissions data directly to EPA.
If the EPA implemented a requirement that all chemicals required by TRI
would also need to be reported to the NEI, States choosing to report
HAP would need to revise their emissions reporting rules not only to
collect HAP, but to also collect the additional air toxics as well.
Given the more limited need for other air toxics data besides HAP at
this time (i.e., primarily for considering listing as HAP), EPA's
current assessment is that the additional burden on States that choose,
on behalf of owners/operators, to report all air toxics reported to TRI
is not warranted in these proposed revisions.
Another aspect of this factor is that some pollutants may be added
to or removed from the list of HAP over time. For major sources, any
new HAP would be required to be reported and any exempted HAP would no
longer be required if a policy requiring all HAP were to be finalized
based on this proposed action. For non-major sources, however, a newly
identified HAP would require an emissions reporting threshold to be set
through future regulatory revisions.
Factor 3: The EPA is also considering the degree of human health
impact on communities as a factor in setting emissions reporting
thresholds. The focus of such reporting thresholds is to ensure that
non-major sources that have significant potential health impacts are
included in the emissions reporting. A reasonable approach for all
pollutants and facility types is to consider estimated risk based on
the available NEI HAP emissions that have been voluntarily reported by
States or included from the TRI program. To develop and assess risk-
based reporting thresholds, the EPA used the data available from the
2017 AirToxScreen.\22\ EPA understands that there are limitations to be
considered when looking at these results, including data gaps due to
voluntary HAP reporting and TRI data available only for certain
facilities. These limitations are described as part of the AirToxScreen
limitations website \23\ as well as the technical documentation
available with the latest AirToxScreen results.\24\ Given these
limitations, the EPA has developed an approach that would use the
available data in a way to lessen any impacts of incomplete data.
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\22\ The EPA 2017 AirToxScreen, <a href="https://www.epa.gov/AirToxScreen">https://www.epa.gov/AirToxScreen</a>.
\23\ U.S. EPA, AirToxScreen Limitations website, <a href="https://www.epa.gov/AirToxScreen/airtoxscreen-limitations">https://www.epa.gov/AirToxScreen/airtoxscreen-limitations</a>.
\24\ U.S. EPA, AirToxScreen Technical Support Documentation,
<a href="https://www.epa.gov/AirToxScreen/airtoxscreen-technical-support-document">https://www.epa.gov/AirToxScreen/airtoxscreen-technical-support-document</a>.
---------------------------------------------------------------------------

The approach taken to develop the proposed reporting thresholds is
fully documented in a separate Technical Support Document (TSD) \25\
and is

[[Page 54135]]

briefly summarized here. First, the EPA modeled air quality pollutant
concentrations around facilities and post-processed those results to
use only concentrations no closer than 100 meters from each emission
point within the facility. This 100-meter approach avoids overly high
concentrations that can occur within the ``fence lines'' of facilities.
``Fence line'' is a phrase used to denote the outer perimeter boundary
of the land on which a facility operates. Typically, members of the
public would not be exposed to concentrations that exist within the
fence line. Both major and non-major facilities can vary in land
coverage, and this approach is an approximation that assumes that 100-
meters is an adequate distance between an emission point and the
associated fence line for purpose of this analysis. In doing so, EPA
has avoided including high concentrations of HAP that can occur within
the fence line of major and non-major sources and instead focuses on
concentrations to which the public would more typically be exposed. In
this analysis, about 95 percent of the distances between emission
release points and the associated location of maximum risk from the
release point was between 100 and 2500 meters, and the remainder were
even farther away. The EPA used the resulting modeled concentrations to
compute cancer risk estimates using pollutant-specific unit risk
estimates (UREs) \26\ and other health impacts (e.g., respiratory,
neurological) with the reference concentration (RfC) for the most
impacted organ system. Generally, the EPA used the same UREs and RfCs
to calculate cancer risk and non-cancer hazard index (HI) as are
currently used in other EPA regulatory actions, and the TSD provides
exceptions to that general approach.
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\25\ U.S. EPA, Technical Support Document: Revisions to the Air
Emissions Reporting Requirements (Proposal), April 2023, available
in the docket for this proposal.
\26\ For assessments of HAP, the EPA generally uses UREs from
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
EPA guidelines and have undergone a peer review process like that
used by the EPA, we may use such dose-response values in place of,
or in addition to, other values, if appropriate.
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Using the cancer risk and HI estimates, the EPA calculated the
level of emissions (``adjusted emissions'') that would be needed to
cause one in a million risk and/or a 0.5 HI for each release point and
HAP at all facilities in the 2017 data. This calculation is possible
because the cancer risk and HI results from the modeling performed can
be scaled linearly based on emissions. To guard against including
release points and pollutants that contribute very minor risk to the
overall facility risk, the EPA excluded any release point/pollutant
combination that contributed to less than 20 percent of the cancer risk
and HI in the 2017 modeled estimates for the associated facility.\27\
The emissions scaling approach allows for the large variety of stacks
and fugitive releases with varied parameters to contribute to the
information with which the EPA could develop emissions reporting
thresholds. Dropping the release point/pollutant combinations that
contributed less than 20 percent of the cancer risk and HI also removes
the smaller sources from the data, which avoids including in the
analysis those types of emissions within facilities that may be less
consequential to overall cancer risk and HI at those facilities. Rather
than rely on a single facility or selected facilities, the approach
provides for a distribution of possible emissions reporting thresholds
so that the EPA can ensure that emissions reporting thresholds are both
robustly based on available data and not overly low causing undue
burden.
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\27\ More information on EPA's approach to set risk-based
emissions reporting thresholds is available in Section 3 of the TSD
for this proposal. Section 3.1 of the TSD further addresses issue of
dropping some data values as part of establishing proposed
thresholds.
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The EPA evaluated several approaches for using the distributions of
adjusted emissions to set an emissions reporting threshold. Ultimately,
the EPA settled on the 10th percentile of the adjusted emissions.
Before arriving at this conclusion, the EPA evaluated the distributions
of adjusted emissions data by using histograms. Both the raw data and
log-transformed data were evaluated. While a handful of the log-
transformed distributions approximated a normal distribution, most of
the distributions had a significant high value bias or low value bias.
Because most histograms did not appear normally distributed, the EPA
has chosen not to use an approach that would rely on standard deviation
from the median of adjusted emissions. The EPA also evaluated using the
median values of the distributions of adjusted emissions to set an
emissions reporting threshold, but these median values were often
several orders of magnitude higher than emissions levels estimated to
cause significant risks based on the 2017 Air Toxics Data Update.
In reviewing the range of values from the distributions of adjusted
emissions, the EPA determined that the 10th percentile of the adjusted
emissions provided a reasonable reporting threshold for each pollutant.
Percentiles below that level too often approached the minimum emissions
levels causing risk in the 2017 Air Toxics Update, and percentiles
above that level may not be rigorous enough to ensure that the EPA
collects sufficient data to be protective of human health.
The EPA is also considering how to collect data from non-major
facilities that have the potential to cause significant and ongoing
impacts without requiring many smaller, lower impact facilities to
report. As illustrated by the previous example of gas stations, some
emissions sectors tend to have many small individual sources that can
be included in the NEI as county total emissions rather than be
included as point sources. To tailor reporting for non-major sources to
specific industries, the EPA analyzed the available 2017 NEI HAP
emissions data to assess the contribution of emissions from each NAICS
code to the total point source emissions for each pollutant. The EPA
applied a threshold of 1 percent contribution by NAICS grouped to the
first 4 digits of the NAICS code for each pollutant. The EPA set this 1
percent threshold to be a conservative approach to identify NAICS-
pollutant combinations for consideration in any proposed policy
approaches before further reviewing each NAICS for relevance in
supporting objectives of this proposed action. By merging the 4-digit
NAICS with the full list of NAICS codes, the EPA created a short-list
of NAICS-pollutant combinations of interest.
The EPA further excluded a NAICS-pollutant combination if: (1) the
NAICS is not currently widely reported as point sources by States for
other reasons and either (2) the NAICS is in an agricultural production
sector or a retail sector more likely to contribute emissions from many
small sources that would better be captured as nonpoint emissions, or
(3) the NAICS is in a service sector (e.g., advertising) that is not
expected to include significant pollutant emissions. Some NAICS were
specifically included when they were used for activities that emit
significant amounts of high-risk pollutants such as ethylene oxide or
hexavalent chromium. With this approach, the EPA is attempting to
strike an appropriate balance between the agency's need for information
with the burden that reporting requirements impose on owners/operators
and/or States. While the EPA utilized its technical discretion to
exclude these NAICS-pollutant combinations at this time, the agency
recognizes that it may be appropriate to revisit these exclusions in
the future.

[[Page 54136]]

To understand the impact of any potential reporting thresholds, the
EPA has estimated the number of additional non-major sources from the
2017 NEI that would have been included for mandatory HAP reporting had
the EPA compiled the 2017 NEI using HAP reporting thresholds based on
the 10th percentile thresholds and NAICS selection approach described
above in addition to special threshold adjustments proposed in section
IV.A.9. This analysis showed that about 115,000 non-major sources could
be added to reporting requirements that currently affect about 13,400
major sources. In making these estimates, the EPA has made numerous
assumptions that would tend to overestimate the number of facilities
that would need to report, to provide conservative estimates for
purposes of burden estimates. The EPA estimates the actual number of
facilities to be lower. More information on this analysis is available
in the TSD for this proposal.
Additionally, while owners/operators and States would be newly
required to report for more facilities, States voluntarily reported HAP
for the 2017 NEI (and therefore collected HAP from owners/operators
largely via State requirements) for about 59,000 facilities, which is
about 46% of the approximately 129,500 facilities EPA estimates would
report under this proposal rule. As a result, the incremental burden
increase of EPA's HAP collection approach would be lower than if all
facilities needed to be newly reported under the proposed AERR
revisions. In the cases in which a State does not choose to report HAP
on behalf of owners/operators under this proposal, the HAP reporting
requirements for such facilities could change in two possible ways.
First, the reporting requirements could shift from being a State
requirement to an EPA requirement for owners/operators of facilities
within States that use CAERS in some way or that eliminate their State
reporting rule. Second, the reporting requirements could become
duplicative for owners/operators within States that choose to not use
CAERS in any way and retain their State reporting rule. For those
pollutants owners/operators are already reporting to the State, there
is little increase in burden. For those additional pollutants (if any)
that would be required under this proposed rule, owners/operators will
have an incremental burden for those additional pollutants but would
not need to learn about emissions reports in general. Further, the
expected increase in facilities and burden needs to be considered in
light of the need by EPA, States, and the public for data that allows
for better understanding and reducing public health risks to
communities. While the current AERR voluntary HAP collection program
gathers a lot of data, the voluntary data does not necessarily have
those pollutants that EPA's analysis shows are most important at those
facilities and does not include all the facilities that the analysis
shows should be collected to inform risk assessments and other EPA
analyses.
Based on these considerations, this action proposes to expand the
definition of point sources at 40 CFR 51.50 to mean a stationary or
portable facility that (1) is a major source under 40 CFR part 70 for
any pollutant, or (2) has PTE or annual actual emissions of pollutants
greater than or equal to the reporting thresholds in Table 1A to
Appendix A of this subpart, or (3) has a primary NAICS code listed in
Table 1C to Appendix A of this subpart and annual actual emissions of
pollutants greater than or equal to the HAP reporting thresholds
(presented in Table 1B to Appendix A of this subpart). Additionally,
the EPA is proposing as part of this definition that, in assessing
whether emissions levels exceed reporting thresholds, all provisions of
this subpart related to emissions estimation approaches would apply,
including Sec. Sec. 51.5 and 51.10 of this subpart.
To further clarify the definition of point sources based in part on
primary NAICS (situation #3 in the paragraph above), the EPA
additionally proposes a definition of primary NAICS. The EPA proposes
that primary NAICS means the NAICS code that most accurately describes
the facility or supplier's primary product/activity/service and that
the ``primary product/activity/service'' is the principal source of
revenue for the facility or supplier. This definition is being proposed
so that the AERR can be consistent with the non-regulatory definition
of primary NAICS used by the U.S. Census bureau. This proposed
definition would serve for purposes of this subpart for both
identifying point sources and reporting primary NAICS.
To set the point source definition, the EPA is proposing to expand
the current Table 1 to Appendix A of Subpart A of Part 51 into four
tables (Tables 1A through 1D of Subpart A of Part 51). Table 1A
provides the proposed point source reporting thresholds for CAPs, which
the EPA proposes would remain unchanged. Table 1B provides the proposed
HAP initial reporting thresholds for non-major sources. Table 1C
provides a proposed list of primary NAICS for non-major sources, and
Table 1D provides a proposed list of individual compounds to be
reported for groups of chemicals with a single reporting threshold from
Table 1B. More information on Table 1D is provided in section IV.I.14
of this preamble.
9. Special Cases of Emissions Thresholds for Non-Major Sources
The risk-based analysis above was not completed for five
situations, which are covered in this section: (1) mercury compounds,
(2) pollutants included in the 2017 NEI but without URE or RfC, (3)
revisions or publication of new URE or RfC, (4) a special case for
dioxins/furans, and (5) the treatment of Pb as both a CAP and HAP.
The risk-based approach was insufficient for mercury compounds
because they have multi-pathway (air, water, soil) effects that were
not captured by the analysis described above.\28\ Without further
evaluation to consider a more inclusive approach, the above approach
may set too high a reporting threshold for mercury. It is important to
ensure complete mercury reporting from sources because, in addition to
using mercury data for risk analysis, the EPA reports trends in total
national mercury emissions based on international agreements such as
the Minamata Convention on Mercury and the Convention on Long-Range
Transboundary Air Pollution. Evaluation of the available 2017 NEI data
shows that the reporting threshold resulting from the mercury HI in the
approach from section IV.A.8 of this preamble (0.15-ton) would require
reporting for only 22 out of about 16,000 sources of mercury currently
compiled in the 2017 NEI. Based on the 2017 emissions data to capture
95 percent of the mass of mercury nationally, a reporting threshold of
0.0026 tons (5.2 lbs) would be needed. To capture 99 percent of those
known values, a reporting threshold of 0.0003 tons (0.6 lbs) would be
needed.
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\28\ Like mercury, other HAP can be persistent/bioaccumulative
(PB-HAP) pollutants that have multipathway effects. Other examples
include arsenic, cadmium, dioxins/furans, lead, and PAHs. For this
proposal, EPA considered only the inhalation pathway for all PB-HAP
pollutants. The inhalation-based thresholds for the PB-HAP, except
mercury, were deemed appropriate for this proposal, but EPA could
consider multipathway effects in other future rulemaking efforts
that could result in different emissions reporting thresholds.
---------------------------------------------------------------------------

The EPA also is considering that mercury emissions in its divalent
form is the portion of mercury emissions of most concern.
Unfortunately, sources often have little information about the form of
the mercury emitted. Measuring

[[Page 54137]]

divalent mercury is much more difficult than simply measuring the total
mercury emitted.
Based on these considerations, the EPA is proposing a mercury
reporting threshold of 0.0026 tons (5.2 lbs), which is based on the
value that captures 95 percent of currently best available data about
mercury from point sources. Irrespective of the form(s) of mercury
reported, the reporting threshold is proposed to be based on total
mercury. The proposed reporting threshold is about two orders of
magnitude lower than the incomplete HI-based approach described above,
which the EPA proposes is reasonable given what is known about multi-
pathway exposures for mercury. The EPA additionally proposes that
mercury would be reported in its more specific forms when such data are
available, but that total mercury would be reported when more specific
forms are not available.
The EPA considered how to set a default emissions reporting
threshold for all remaining pollutants without an URE or RfC. Without
risk data to use to inform such an approach, EPA has proposed to use
the major source threshold of 10 tons/year for a single pollutant. For
the third special case, the EPA is considering that it may be useful to
have a mechanism by which the Agency would revise reporting thresholds
for pollutants in the case that a significant revision to an existing
URE or RfC becomes available following new scientific findings that
could significantly impact EPA's understanding of risk posed by such a
pollutant. One example of this situation is provided by ethylene oxide
(EtO), when the EPA determined EtO was a much more potent carcinogen
than previously realized.\29\ Rather than being able to rely on an
existing requirement to collect data more quickly as is being proposed
here, the EPA needed to collect data ad-hoc from 2019 through to 2022
to obtain additional emissions data about these facilities. The data
collection process took additional time, delaying a response that could
have more quickly addressed public health concerns. This delay would
have been avoided if emissions data reporting requirements had, at that
time, included a provision such as the one the EPA is now considering.
---------------------------------------------------------------------------

\29\ U.S. EPA, Evaluation of the Inhalation Carcinogenicity of
Ethylene Oxide (Final Report), EPA/635/R-16/350F, 2016.
---------------------------------------------------------------------------

The EPA has a tiered, prioritized list of appropriate chronic
health benchmark values and, in general, the list prioritization places
greater weight on the EPA-derived health benchmarks than those from
other agencies.\30\ The EPA has a prioritization process aimed at
incorporating the best available science with respect to dose-response
information for air toxics. This information is obtained from various
sources and prioritized according to (1) conceptual consistency with
EPA risk assessment guidelines and (2) level of peer review received.
Where the EPA lacks dose-response information with higher priority
(e.g., IRIS), the Agency uses other information sources, such as from
the Agency for Toxic Substances and Disease Registry (ATSDR) and the
California EPA. To ensure the EPA could collect emissions data for HAP
that receive updated health benchmarks that meet the EPA criteria and
would receive prioritization, it would be necessary to adjust the
health-based emissions reporting thresholds included in this proposal.
---------------------------------------------------------------------------

\30\ The health benchmark review process is described at <a href="https://www.epa.gov/iris/basic-information-about-integrated-risk-information-system#process">https://www.epa.gov/iris/basic-information-about-integrated-risk-information-system#process</a>.
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The EPA occasionally identifies new health benchmarks for
pollutants that do not have them or revises the available benchmarks to
reflect a new understanding of a HAP's increased or decreased toxicity.
When the available toxicity information about pollutants changes in the
future, the EPA expects that it will propose updated emissions
reporting thresholds, take comment, and potentially issue final
revisions to the HAP emissions reporting thresholds of this subpart. At
this time, EPA plans to conduct such revisions in the future via very
targeted rulemaking to amend just those HAP emissions reporting
thresholds where the toxicity information has changed.
To streamline future actions associated with any revised health
benchmarks, the EPA proposes that it may use the following formulas to
develop updates for the point source HAP reporting thresholds of this
subpart. For changes to UREs, the updated reporting threshold would be
calculated using the formula: Updated reporting threshold = (reporting
threshold in AERR x URE in 2022)/updated URE, where the ``reporting
threshold in AERR'' refers to the reporting thresholds provided in the
proposed Table 1B to Appendix A of this subpart. For changes to RfCs,
the updated reporting threshold would be calculated using the formula:
Updated reporting threshold = (reporting threshold in AERR x revised
RfC)/RfC in 2022.
Further, the EPA proposes that only those HAP reporting thresholds
that the EPA publishes in the Federal Register (after notice and
comment) 6 months before the end of an inventory year would apply for
reporting emissions for that inventory year. For example, any reporting
threshold published before July 1, 2027, would be relevant for
emissions reporting of 2027 emissions, with those reports being due in
2028. This timing may not leave sufficient time for States to revise
their HAP reporting regulations if they are reporting on behalf of
owners/operators. Thus, the EPA recommends that States should consider
the possibility of drafting their HAP reporting requirements such that
they would refer to Table 1B to Appendix A of this subpart rather than
list the same thresholds in their own rules. The EPA additionally
proposes to publish any updates to emissions reporting thresholds on
its Air Emissions Inventories website to help States and owners/
operators to be able to find the new reporting thresholds more easily.
Some pollutant reporting thresholds included for non-major sources
in the proposed Table 1B to Appendix A of this subpart are listed as 10
tpy, which is the major source threshold. If a point source had
emissions of 10 tons, then it would presumably be subject to these
proposed reporting requirements based on its status as a HAP major
source, which would eliminate the need for including such reporting
thresholds in the table. However, to support the possibility that an
emission reporting threshold could be updated based on changes to a
pollutant's URE or RfC, the 10-ton reporting threshold would be
retained in the proposed Table 1B to Appendix A of this subpart to
provide the ``reporting threshold in AERR'' value needed for the
updated reporting threshold calculations proposed above. Additionally,
including those pollutants in Tables 1B and 1D allows for a more
comprehensive list of pollutants to inform owners/operators and States
of EPA's expectations and so that the pollutant group relationships
listed in Table 1D can be provided.
The fourth special case is dioxins/furans. These pollutants were
not included in the risk-based approach described above since they were
not included in the 2017 NEI and were not a part of the risk modeling
work on which the approach relied. Given the extremely high toxicity of
some dioxins/furan pollutants (called congeners), the EPA is
considering the approach taken by the TRI program. In addition, while
dioxins/furans are not listed as a group on the published list of HAP,
these HAP are often treated as a group for various purposes. For
example, the TRI program

[[Page 54138]]

sets a reporting threshold for these compounds in the aggregate of 0.1
gram manufactured, processed, or otherwise used. For TRI reporting,
when owners/operators report dioxins/furans, they must submit the mass
of each of the congeners of dioxins/furans.
The EPA proposes the non-major reporting threshold for reporting
dioxins/furans would be based on the TRI reporting threshold of 1.1 E-
07 tons (~0.1 gram) and would apply to the sum of dioxins/furans mass.
To meet this requirement, owners/operators would need to sum the mass
of the individual congeners. By proposing this threshold for the AERR,
the EPA is aligning the thresholds as best as possible to reduce
complexity and burden. The EPA's proposed approach for the AERR is a
less stringent threshold than the TRI threshold because facilities that
manufacture, process, or otherwise use dioxins/furans would likely not
emit all of that material to the air. As such, the EPA is not adding
any burden on facilities to recognize that they may need to report to
the AERR, but rather to estimate their dioxin/furan emissions at the
additional level of detail proposed in the AERR as compared to the
facility total emissions reported to TRI.
Finally, with respect to the Pb reporting threshold, the EPA is
considering that Pb has a role for both CAP reporting and HAP
reporting, since it falls under both NAAQS and air toxics provisions of
the CAA. The EPA is not proposing to change CAP reporting thresholds
(including Pb) in Table 1A to Appendix A of this subpart and is not
proposing to change the current AERR requirement to report all CAP
emissions if any CAP is above the PTE reporting thresholds (or Pb
actual emissions threshold). The EPA approach for risk-based reporting
thresholds described in section IV.A.8 results in a 0.074 tpy Pb
reporting threshold. The EPA is considering that if it were to modify
the CAP reporting threshold for Pb to be 0.074 tpy, this would have the
effect of requiring reporting for all CAPs at facilities with Pb
exceeding the 0.074 tpy threshold. The EPA does not intend to require
CAP emissions (other than Pb) as point source for such small emissions
levels. Based on these considerations, the EPA is proposing to retain
the 0.5 tpy actual emissions reporting threshold for CAP reporting and
additionally propose a Pb reporting threshold of 0.074 tpy actual
emissions for purposes of HAP reporting.
Under the proposed approach, all States would continue to report Pb
for point sources as required based on the CAP reporting thresholds.
States that optionally report HAP on behalf of owners/operators would
also report Pb for sources based on the HAP reporting threshold, and
any other HAP from those facilities that would be required by this
proposed action, and any other pollutants, including CAPs, that the
State chooses to report. In States that do not report HAP on behalf of
facilities, owners/operators would themselves be responsible for
reporting Pb directly to the EPA for any facility that emits over the
HAP reporting threshold (0.074 tpy) and that does not exceed the CAP
reporting thresholds (for any CAP) and thus would not be required to be
reported by a State.
Under the current AERR, some States voluntarily report Pb emissions
for sources below the required reporting thresholds for CAPs. Thus,
under the proposed approach, it is possible that the EPA could receive
Pb data from both a State and an owner/operator for the same facility.
In this case, the EPA would need to select one of these data values to
include in the NEI. If an owner/operator is required to report (and
does report) Pb emissions data for a facility (i.e., the State is not
approved to report on their behalf), but the State also voluntarily
submits that data for the same facility, then the EPA will use the data
from the owner/operator. The EPA would plan to note any difference
between the emissions submitted by the State and the owner/operator in
quality review materials provided to both parties.
10. Pollutants To Be Required or Optional for Point Sources
The EPA is considering which pollutants would be reported by
owners/operators of facilities once a facility has been determined to
be a point source. This action does not propose changes to which CAPs
would be reported. With the proposed revision to require HAP, the EPA
is considering how to handle cases in which a facility is required to
report HAP but does not exceed the reporting threshold for CAPs. The
term ``incidental CAPs'' will be used hereafter to refer to CAP
emissions that would be reported only because a facility is a point
source due to its HAP emissions. This situation is exemplified by a
facility that emits one ton of nickel per year (exceeding the proposed
Ni reporting threshold of 0.0021 tpy) but does not exceed the 100 tpy
potential-to-emit reporting threshold for PM<INF>2.5</INF>. An ideal
policy should include a mechanism to prevent the discrepancy that would
result when the facility reports the nickel emissions of one ton and
zero PM<INF>2.5</INF> emissions, since nickel is a part of
PM<INF>2.5</INF>.
To address this issue, the EPA is proposing to require reporting of
incidental CAPs by owners/operators that report HAP for point sources,
and by States when a State has been approved to report HAP on behalf of
owners/operators. To support this requirement, the EPA is additionally
proposing the definition of incidental CAPs to mean ``a criteria
pollutant or precursor emitted from a facility that meets the point
source reporting definition due to emissions of HAP but has emissions
of criteria pollutants and precursors below reporting thresholds for
those pollutants.'' To inform this proposed approach, the EPA is
considering whether a voluntary approach or a requirement would work
best and the nature of any requirement.
Under a voluntary approach, owners/operators or States would not be
required to report incidental CAPs, but such emissions could be
reported voluntarily. This would impose a lower burden but may create
inconsistencies in the NEI data at the facility level when CAP data are
not voluntarily reported (as described by the example provided above
about a facility reporting nickel without reporting PM<INF>2.5</INF>).
To address any such inconsistencies, the EPA could augment the NEI by
summing any HAP reported without associated CAPs. For example, if a
facility were to report 1 ton of nickel, 0.2 tons of cadmium, and 0.3
tons of antimony as their only PM HAP, then the EPA could sum these
values to include 1.5 tons of PM<INF>2.5</INF> in the NEI. While
avoiding inconsistency, this approach would create partial data for
PM<INF>2.5</INF> that would appear to be complete, and thus could cause
confusion that would be better to avoid by estimating or collecting
total PM<INF>2.5</INF>.
The EPA also is considering the possibility of using the required
throughput (activity) data reported by owners/operators for the HAP to
estimate the CAP emissions on behalf of owners/operators. This approach
slightly reduces burden as compared to the proposed approach of
requiring incidental CAP, though it complicates the NEI process and
adds annual emissions data to the NEI after owners/operators have
already submitted. In the past, the EPA has found that if owners/
operators or States do not submit complete emissions, they can be
surprised by EPA's additions to their data prior to NEI publication.
Further, there is no guarantee that all sources of the incidental CAP
at a facility also have emissions of HAP, making any estimate by the
EPA based on throughput data used to estimate HAP potentially
incomplete. In EPA's experience, these disadvantages are better
avoided.

[[Page 54139]]

A requirement to report incidental CAPs has the advantages of
collecting additional CAP emissions data for a more detailed NEI and
boosting consistency between emissions of HAP and their associated CAPs
(like VOC and PM<INF>2.5</INF>). Such a requirement would also have the
disadvantage of additional burden on owners/operators to estimate and
report more pollutants.
In considering a requirement to report incidental CAPs, the EPA is
considering two possibilities for implementation: (1) States could be
required to report CAP emissions of such sources rather than owners/
operators, consistent with the overall CAP reporting approach taken in
the AERR or (2) owners/operators could be required to report CAPs
directly to the EPA consistent with the HAP reporting requirement. To
implement the first approach, all States would need to modify their
State regulations to update the definition of which sources would
report CAPs to include HAP reporting thresholds. Such a modification
would be necessary under the first approach, regardless of whether the
State intends to be responsible for reporting HAP emissions on behalf
of owners/operators. This poses a significant disadvantage.
The EPA is proposing the second approach listed above for owners/
operators to report incidental CAPs. This approach does not require
States to modify their CAP reporting regulations and still allows
States to report incidental CAPs if they report HAP emissions. Under
the proposed approach, the State HAP submission application and
approval process described in section IV.A.6 of this preamble would,
therefore, also include the reporting by States of incidental CAPs
associated with such facilities. The proposed approach also works well
with the requirement for owners/operators to report emissions using
CAERS, because CAERS assists owners/operators with emissions factors
for both HAP and CAPs associated with their emissions processes and
provides other advantages to streamline reporting. Additionally, the
EPA plans that future versions of CAERS would have the direct access to
the source tests reported to CEDRI to support use of source test data
for estimation of incidental CAP. The EPA expects the source test data
to be useful for this, because of the frequent approach taken by NESHAP
rules to collect a surrogate pollutant report, such as filterable
PM<INF>2.5</INF>, to ensure compliance with HAP emissions limits. Thus,
the incremental burden for a facility reporting to the EPA directly via
CAERS to report incidental CAPs would be lower than if CAERS were not
required. Since some such facilities may not already be regulated for
CAPs by States, some may be less likely to have source testing or other
emissions factor data. In these cases, owners/operators could simply
use the default emissions factors provided by the EPA in CAERS when
available.
Based on these considerations, the EPA proposes that owners/
operators would be required to report incidental CAPs associated with
HAP being reported when they are required to report HAP but would not
otherwise be required to report CAP (i.e., they are not a major source
for CAP). This requirement would impact reporting emissions for HAP
major sources and for non-major sources when required to report HAP.
If applying to the EPA to report HAP on behalf of owners/operators,
a State would need to consider the incidental CAP requirement when
designing any updated emissions collection regulations. The proposed
Table 1B to Appendix A of this subpart includes which criteria
pollutants are associated with each HAP and would determine the CAPs
expected to comply with this propose incidental CAP reporting
requirement. This approach has the advantages previously noted and, in
addition, it solves the same collection and consistency challenge for
States by providing a framework for any States that choose to report
HAP on behalf of owners/operators.
In addition to incidental CAPs, the EPA is considering which HAP
would be reported by owners/operators of facilities that meet the point
source definition. As described above, this action proposes that
owners/operators of HAP and CAP major sources report all HAP. This
proposed requirement would be consistent with EPA's obligations under
the Act to regulate all pollutants from such HAP major sources and
includes CAP major sources to have available to the agency a complete
suite of pollutants from all large emitters.
For non-major sources, the EPA proposes that owners/operators would
be required to report only those HAP that are greater than EPA's HAP
reporting thresholds, initial values for which are presented in the
proposed Table 1B to Appendix A of this subpart. To identify this
proposed approach for non-major sources, the EPA compared this proposed
approach to an alternative by which owners/operators of non-major
sources would report all HAP when any one HAP has emissions greater
than or equal to the proposed reporting thresholds. To choose an
approach, the EPA is weighing the additional burden associated with
reporting all HAP relative to the importance of additional data that
would be collected if all HAP were required.
To understand the effects of this proposed action, the EPA
evaluated the relative impact of the HAP pollutant requirements. The
incidental CAP impact is expected to be small because it would add just
one or two pollutants per facility and the requirement could be met
using emissions factors. Thus, the incremental CAP impact was not
separately analyzed from the total HAP impact. The EPA used the 2017
NEI data to estimate the number of additional combinations of
facilities and HAP pollutants as a surrogate to estimate incremental
burden from each policy choice relative to the option of reporting all
HAP for HAP major sources. Table 1 below provides these results by
including a ``burden'' factor calculated using the estimated number of
facility-pollutant combinations associated with a policy option divided
by the estimated number of facility-pollutant combinations associated
with all pollutants from the identified HAP major facilities.
These relative burden estimates are imperfect because they rely on
the 2017 NEI that is known to be incomplete (since HAP reporting is
currently voluntary), but they still represent the best data available
to the EPA at the time the analysis was performed. To compare the
burden between the proposed non-major approach and the alternative non-
major approach, the EPA counted the number of records in the 2017 NEI
with HAP emissions. In the proposed case, the EPA included only those
records associated with the HAP at a facility for HAP exceeding the
proposed thresholds. For the alternative case, the EPA included all HAP
records at a facility when any HAP exceeded the proposed thresholds.
Based on these counts, the EPA estimates a 40% increase in burden
associated with the alterative that the EPA is not proposing.
The EPA has considered whether a 40% burden increase to collect
additional HAP data (below risk-based reporting thresholds) from non-
major sources would be warranted. In considering this, the EPA has been
unable to identify a reason to collect those additional HAP (unlike for
major sources, which as noted starting in section IV.A.4 of this
preamble, the Act directs EPA to consider all HAP). While the data
would certainly be more complete under the alternative approach, the
risk-based reporting thresholds that the EPA is proposing would provide
substantially more data

[[Page 54140]]

than the Agency currently has. Rather than impose additional burden,
the EPA is proposing to require that owners/operators of non-major
sources would report emissions only when those emissions are greater
than or equal to the HAP reporting thresholds, presented in Table 1B to
Appendix A of this subpart, but subject to revision as described above.
The EPA urges commenters to provide comment to it regarding any factors
the Agency may have missed in selecting the proposed approach.
In addition to the burden of the various policy options for HAP
emissions reporting, the EPA evaluated the distribution of sources
across communities for informational purposes.\31\ The results in Table
1 provide three types of areas where facilities emit pollutants in
amounts that classify those sources as major sources or levels of HAP
for non-major sources that meet the proposed reporting thresholds of
this action. Table 1 illustrates the demographic make-up of the
populations located within 5 km of the facilities that would be
required to report under the proposed policy options. The demographics
are based on indicators from the Bureau of Census' 5-year American
Community Survey (ACS).\32\ The column ``Nationwide'' represents the
nationwide average percent demographics for comparison. The following
three columns ``CAP Major,'' ``HAP Major,'' and ``Non-Major,''
represent the average percent demographics of the populations living
within 5 km of the facilities in each group of facilities. For this
analysis, the EPA used a 5-km distance to try to capture the
appropriate demographics for near-field exposures. Based on previous
air dispersion modeling of HAP emissions from over 1,600 facilities in
22 source categories, the average distance of the maximum individual
cancer risk (MIR) is about 2 km from the facility. A distance of 5 km
was chosen because it captures 95 percent of MIR locations for these
1,600 facilities. Section 6 of the TSD provides additional details.
Regarding race and ethnicity, the data show that on average, the
populations living around facilities affected by this action are above
the percent national average. While the national average population for
African Americans is 12 percent, the percentage of this demographic
group near facilities is between 15 and 17 percent, depending on the
facility type. Similarly, the Hispanic/Latino population average is 19
percent, and the percentage of this demographic near facilities is 22
to 23 percent. For the Other Multiracial population, the average
nationally is 8 percent while the percentage of this demographic near
facilities is 9 to 10 percent. In addition, the populations living
around facilities affected by this action are above the percent
national average for ``Below Poverty Level,'' ``Over 25 and without a
High School Diploma,'' and ``Linguistically Isolated.'' Since the
reporting thresholds are largely based on risk contribution, these
results show that owners/operators will report HAP from facilities
emitting at levels contributing to risk in both low-income areas an in
communities with a higher minority population than average.
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\31\ This analysis was completed prior to a few minor revisions
to the NAICS list and emissions thresholds (added 5622xx for Waste
Treatment and Disposal and 62231x for Specialty Hospitals). No
facilities are in the 2017 NEI used in this analysis for 62231x. The
EPA also revised the cobalt threshold after this analysis was done.
The EPA has reprocessed the facility analysis and about 2,000
facilities were added since the EJ analysis was completed. The EPA
believes that the results of the analysis are still highly
representative of the proposed reporting criteria because the
analysis included more than 17,700 facilities.
\32\ U.S. Census Bureau American Community Survey Data, <a href="https://www.census.gov/programs-surveys/acs/data.html">https://www.census.gov/programs-surveys/acs/data.html</a>.

Table 1--Percent of Population by Demographic for Populations Nationwide and Within 5 km of CAP Major
Facilities, HAP Major Facilities, and Non-Major Facilities
----------------------------------------------------------------------------------------------------------------
HAP major:
CAP major: population Non-major:
population within 5 km of population
Demographic group Nationwide within 5 km of 7,552 within 5 km of
4,067 facilities 6,096
facilities (including HAP/ facilities
CAP major)
----------------------------------------------------------------------------------------------------------------
Total Population \a\............................ 328,016,242 69,683,592 117,946,858 93,000,649
----------------------------------------------------------------------------------------------------------------
Race and Ethnicity by Percent
----------------------------------------------------------------------------------------------------------------
White........................................... 60 50 52 52
African American................................ 12 17 16 15
Native American................................. 0.7 0.4 0.4 0.4
Hispanic or Latino (includes white and nonwhite) 19 23 22 23
\b\............................................
Other and Multiracial........................... 8 9 9 10
----------------------------------------------------------------------------------------------------------------
Income by Percent
----------------------------------------------------------------------------------------------------------------
Below Poverty Level............................. 13 16 16 15
Above Poverty Level............................. 87 84 84 85
----------------------------------------------------------------------------------------------------------------
Education by Percent
----------------------------------------------------------------------------------------------------------------
Over 25 and without a High School Diploma....... 12 14 14 14
Over 25 and with a High School Diploma.......... 88 86 86 86
----------------------------------------------------------------------------------------------------------------

[[Page 54141]]

Linguistically Isolated by Percent
----------------------------------------------------------------------------------------------------------------
Linguistically Isolated......................... 5 8 7 7
----------------------------------------------------------------------------------------------------------------
\a\ The nationwide population and all demographic percentages are based on the Census' 2015-2019 American
Community Survey 5-year block group averages and include Puerto Rico. The total population count within 5 km
of all facilities is based on the 2010 Decennial Census block populations.
\b\ To avoid double counting, the ``Hispanic or Latino'' category is treated as a distinct demographic category
for these analyses. A person who identifies as Hispanic or Latino is counted as Hispanic/Latino for this
analysis, regardless of what race this person may have also identified as in the Census.

Table 2 below provides the estimated number of known facilities
from the 2017 NEI expected to be impacted by these proposed HAP
reporting requirements for which the average percent of the population
within 5 km exceeds the national average for different demographics.
These results show that a significant number of the known facilities
for which the proposed action could collect better data are located
near areas of interest for environmental justice issues.

Table 2--Number of Facilities for Which the Population Within 5 km Exceeds the National Average for Different
Facility Categories and Different Demographics.
----------------------------------------------------------------------------------------------------------------
HAP major
CAP major facilities Non-major
Demographic group \a\ facilities (includes HAP/ facilities
CAP major)
----------------------------------------------------------------------------------------------------------------
Total Number of Facilities...................................... 4,067 7,552 6,096
----------------------------------------------------------------------------------------------------------------
Race and Ethnicity
----------------------------------------------------------------------------------------------------------------
White........................................................... 2,393 4,878 4,306
African American................................................ 958 2,608 1,231
Native American................................................. 731 1,287 1,664
Hispanic or Latino (includes white and nonwhite) \b\............ 974 1,657 1,396
Other and Multiracial........................................... 679 1,088 1,014
----------------------------------------------------------------------------------------------------------------
Income
----------------------------------------------------------------------------------------------------------------
Below Poverty Level............................................. 1,812 4,082 2,649
----------------------------------------------------------------------------------------------------------------
Education
----------------------------------------------------------------------------------------------------------------
Over 25 and without a High School Diploma....................... 1,793 3,959 2,606
----------------------------------------------------------------------------------------------------------------
Linguistically Isolated
----------------------------------------------------------------------------------------------------------------
Linguistically Isolated......................................... 811 1,338 1,012
----------------------------------------------------------------------------------------------------------------
\a\ Demographic data are based on the Census' 2015-2019 American Community Survey 5-year block group averages
and include Puerto Rico. The total population count within 5 km of all facilities is based on the 2010
Decennial Census block populations.
\b\ To avoid double counting, the ``Hispanic or Latino'' category is treated as a distinct demographic category
for these analyses. A person who identifies as Hispanic or Latino is counted as Hispanic/Latino for this
analysis, regardless of what race this person may have also identified as in the Census.

11. Reporting Release Coordinates
In conjunction with the proposed requirements to report HAP
emissions, the EPA is considering the need for accurate location
information of HAP emissions releases to be able to perform
appropriately detailed assessments of risk using models. The EPA
estimates concentrations and associated risk from HAP emitted from
facilities using the AERMOD modeling system \33\ and uses HAP emissions
in other models for various analyses. These models rely on emissions
data as input, and the most complete modeling approaches include
emissions at the many individual release points that can exist at
facilities. Large facilities can have hundreds of individual release
locations, and the proximity of those releases to people and
communities is an important aspect of proper risk estimation for
populations. Emission releases are

[[Page 54142]]

compiled in the NEI as either stack releases or fugitive releases.
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\33\ AERMOD modeling system home page, EPA, <a href="https://www.epa.gov/scram/air-quality-dispersion-modeling-preferred-and-recommended-models#aermod">https://www.epa.gov/scram/air-quality-dispersion-modeling-preferred-and-recommended-models#aermod</a>.
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The EPA proposes a requirement that owners/operators and States
reporting emissions data directly to the EPA would report release point
locations that are distinct from the facility location. This proposed
requirement would apply for both stack locations and fugitive release
locations. To arrive at this proposed approach, the EPA is considering
a variety of factors described in this section.
Stack and fugitive releases in the NEI are already required to be
reported by the current AERR. In addition, stack parameters such as
height, release diameter, exit gas temperature, and exit gas velocity
are also required so that models can simulate the buoyancy of emissions
plumes and dispersion in surrounding areas. For fugitive releases, the
current AERR also requires parameters to characterize the shape of the
fugitive release as 2- or 3-dimensional, the width, length, and height
of the emissions release, and the orientation of the release shape. In
both cases, however, the current AERR does not require that release
point locations be specific to each release point. Rather, it allows
States to report only the overall facility location, and, in that case,
the EPA uses the facility location to set default release point
locations for that facility when States do not provide specific release
point locations.
The current AERR approach was promulgated in 2015 (80 FR 8787,
February 19, 2015). In that final rulemaking, the EPA changed the
requirement for States to provide X Stack Coordinate (longitude) and Y
Stack Coordinate (latitude) only at the facility location, rather than
for the stack locations. In that final action, the EPA explained that
``most states do not have accurate location values for each individual
release point within a facility; instead, they frequently report the
same locations for all stacks within a facility'' (80 FR 8792, February
19, 2015). In addition, the EPA stated that ``the vast majority of
facilities are geographically small enough that such a simplification
does not reduce the usefulness of the data and we encourage States to
optionally report individual stack locations to add accuracy beyond the
single facility center location. The EPA may also add such individual
stack locations where the agency believes it has accurate data'' (80 FR
8792).
The context of that AERR revision was within the requirements for
collecting CAP emissions. The primary use of the NEI for CAP pollutants
is for Eulerian grid modeling such as the Community Multiscale Air
Quality (CMAQ) modeling system,\34\ for which emissions sources are
mapped to grid cells for modeling. These grid cells are typically 4- or
12-km, which is the context for the statement made in the 2015 AERR
revision that ``the vast majority of facilities are geographically
small enough that such a simplification does not reduce the usefulness
of the data'' (80 FR 8792). For the case of such grid modeling, using a
single facility-wide latitude/longitude for stacks would at worst,
misplace some of the emissions from a facility into a neighboring grid
cell when a facility size is such that it crosses a grid cell boundary.
Given other modeling uncertainties of Eulerian grid modeling, this
additional uncertainty would not be a concern for most modeling
applications in the relatively few cases where it occurred. In cases
that need more locational detail, the EPA could revise the inventory to
correct any release point locational inaccuracies caused by the current
AERR's approach to the release point coordinate requirements. The EPA
received no comments regarding this revision during the comment period
for the June 20, 2013, proposed rule (78 FR 37164).
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\34\ Community Multiscale Air Quality Modeling System home page,
U.S. EPA, <a href="https://www.epa.gov/cmaq">https://www.epa.gov/cmaq</a>.
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In the context of the HAP emissions reporting requirements proposed
in this action, the EPA is revisiting the requirement for accurate
release point locations. The EPA's experience with risk modeling using
HAP emissions inventories has been that using default facility
locations for all release points provides lower quality results than
when models use more detailed data. Using imprecise locations can
provide inaccurate risk information that could overstate or understate
cancer risk significantly. Research has concluded that improved
locational data and release parameters can reduce uncertainty in a risk
assessment by up to 2 orders of magnitude.\35\ These modeling results
are especially sensitive to the distance between the residential
receptor and the emission sources, especially for facilities that have
a large industrial footprint.
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\35\ Jing, Q., Venkatram, A., Princevac, M., Pankratz, D.,
Wenjun., Q., Modeling Dispersion of Buoyant Emissions from a Low
Level Source in an Urban Area, American Meteorological Society, The
Conference Exchange, 2010. See also <a href="https://ams.confex.com/ams/pdfpapers/160624.pdf">https://ams.confex.com/ams/pdfpapers/160624.pdf</a>.
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Because risk is very related to proximity of the source to
populations, when a large facility has emissions releases that border
neighborhoods, the risk can be greatly understated if EPA were to use a
single central facility-wide location. The EPA's modeling guidance for
urban air toxics modeling \36\ explains that ``each source will need to
be classified as a point, area, volume, or line source,'' and that
``building the source inventory usually begins with mapping the
locations of emissions sources.'' Also in the guidance, subsections in
Section 1.3 indicate how modelers should define each of the different
types of release points and specify ``location of the source'' (point
source characterization), ``location, geometry, and relative height''
(for 2-dimensional release points, called ``area sources'' in the
guidance). Likewise, Section 7.2 of the ``Air Toxics Assessment
Reference Library, Volume 2, Facility-Specific Assessment'' \37\
explains that model inputs needed by the Human Exposure Model (HEM)
require ``the geographical location (latitude and longitude) of each
source being simulated (with ``source'' in this context being each
release point at a facility) and states that ``the model requires that
coordinate data be obtained for each emission source in the analysis,
and that each emission source is modeled individually.''
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\36\ Dispersion Modeling of Toxic Pollutants in Urban Areas and
Appendices, U.S. EPA, Document No. 454-R-99-021, July 1, 1999;
<a href="https://www.epa.gov/scram/air-modeling-guidance-air-toxics-modeling">https://www.epa.gov/scram/air-modeling-guidance-air-toxics-modeling</a>.
\37\ Air Toxics Risk Assessment Reference Library, U.S. EPA,
<a href="https://www.epa.gov/fera/air-toxics-risk-assessment-reference-library-volumes-1-3">https://www.epa.gov/fera/air-toxics-risk-assessment-reference-library-volumes-1-3</a>.
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As further evidence of this need, EPA has previously found it
necessary to collect limited sets of this data from certain industries
to support modeled risk analysis for the Risk and Technology Review
(RTR) program required by CAA sections 112(f)(2) and 112(d)(6).\38\
These one-time requests included collection of

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