6560-50-P
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 98
[EPA-HQ-OAR-2019-0424; FRL-x-x]
RIN 2060-AU35
Revisions and Confidentiality Determinations for Data Elements Under the Greenhouse Gas Reporting Rule; Proposed Rule
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
SUMMARY: The Environmental Protection Agency (EPA) is proposing to amend specific provisions in the Greenhouse Gas Reporting Rule to improve the quality and consistency of the data collected under the rule, streamline and improve implementation, and clarify or propose minor updates to certain provisions that have been the subject of questions from reporting entities. These proposed changes include revisions to improve the existing calculation, recordkeeping, and reporting requirements of Part 98 by incorporating updates to existing emissions estimation methodologies and providing for collection of additional data to understand new source categories or new emission sources for specific sectors. The proposed changes would improve understanding of the sector-specific processes or other factors that influence greenhouse gas emissions rates, improve verification of collected data, and complement or inform other EPA programs. The EPA is also proposing revisions that would improve implementation of the Greenhouse Gas Reporting Rule such as updates to applicability estimation methodologies, providing flexibility for or simplifying calculation and monitoring methodologies, streamlining recordkeeping and reporting, and other minor technical corrections or clarifications. This action also proposes to establish and amend confidentiality determinations for the reporting of certain data elements to be added or substantially revised in these proposed amendments. Further, this action includes a request for comment to solicit information that may aid in potential future revisions to the Greenhouse Gas Reporting Rule.
DATES: Comments. Comments must be received on or before [INSERT DATE 60 DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER]. Under the Paperwork Reduction Act (PRA), comments on the information collection provisions are best assured of consideration if the Office of Management and Budget (OMB) receives a copy of your comments on or before [INSERT DATE 60 DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER].
Public Hearing. The EPA does not plan to conduct a public hearing unless requested. If anyone contacts us requesting a public hearing on or before [INSERT DATE 5 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER], we will hold a virtual public hearing. See SUPPLEMENTARY INFORMATION for information on requesting and registering for a public hearing.
ADDRESSES: Comments. You may submit your comments, identified by Docket Id. No. EPA-HQ-OAR-2019-0424, by any of the following methods:
Federal eRulemaking Portal: https://www.regulations.gov (our preferred method). Follow the online instructions for submitting comments.
Mail: U.S. Environmental Protection Agency, EPA Docket Center, Air and Radiation Docket, Mail Code 28221T, 1200 Pennsylvania Avenue NW, Washington, DC 20460.
Hand Delivery or Courier (by scheduled appointment only): EPA Docket Center, WJC West Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004. The Docket Center's hours of operations are 8:30 a.m.-4:30 p.m., Monday-Friday (except federal holidays).
Instructions: All submissions received must include the Docket Id. No. for this proposed rulemaking. Comments received may be posted without change to https://www.regulations.gov/, including any personal information provided. Out of an abundance of caution for members of the public and our staff, the EPA Docket Center and Reading Room are closed to the public, with limited exceptions, to reduce the risk of transmitting Coronavirus 2019 (COVID-19). Our Docket Center staff will continue to provide remote customer service via email, phone, and webform. We encourage the public to submit comments via https://www.regulations.gov/ or email, as there may be a delay in processing mail and faxes. Hand deliveries and couriers may be received by scheduled appointment only. For further information on EPA Docket Center services and the current status, please visit us online at https://www.epa.gov/dockets.
Once submitted, comments cannot be edited or withdrawn. The EPA may publish any comment received to its public docket. Do not submit electronically any information you consider to be confidential business information (CBI) or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission (i.e., on the web, cloud, or other file sharing system). For additional submission methods, the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.
FOR FURTHER INFORMATION CONTACT: Jennifer Bohman, Climate Change Division, Office of Atmospheric Programs (MC-6207A), Environmental Protection Agency, 1200 Pennsylvania Ave., NW, Washington, DC 20460; telephone number:<PHONE_NUMBER>; e-mail address<EMAIL_ADDRESS>For technical information, please go to the Greenhouse Gas Reporting Program (GHGRP) website, https://www.epa.gov/ghgreporting. To submit a question, select Help Center, followed by "Contact Us."
Worldwide Web (WWW). In addition to being available in the docket, an electronic copy of this proposal will also be available through the WWW. Following the Administrator's signature, a copy of this proposed rule will be posted on the EPA's GHGRP website at https://www.epa.gov/ghgreporting.
SUPPLEMENTARY INFORMATION:
Participation in virtual public hearing. Please note that the EPA is deviating from its typical approach for public hearings because the President has declared a national emergency. Due to the current Centers for Disease Control and Prevention (CDC) recommendations, as well as state and local orders for social distancing to limit the spread of COVID-19, the EPA cannot hold in-person public meetings at this time.
To request a hearing, please contact the person listed in the following FOR FURTHER INFORMATION CONTACT section by [INSERT DATE 5 DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER]. If requested, the virtual hearing will be held on [INSERT DATE 15 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. The hearing will convene at 9:00 a.m. Eastern Time (ET) and will conclude at 3:00 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 provide further information about the hearing on its website (https://www.epa.gov/ghgreporting) if a hearing is requested.
Upon publication of this document in the Federal Register (FR), the EPA will begin pre-registering speakers for the hearing, if a hearing is requested. To register to speak at the virtual hearing, please use the online registration form available at https://www.epa.gov/ghgreporting. If you have questions regarding registration, consult the person listed in the preceding FOR FURTHER INFORMATION CONTACT section. The last day to pre-register to speak at the hearing will be [INSERT DATE 12 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. Prior to the hearing, the EPA will post a general agenda that will list pre-registered speakers in approximate order at: https://www.epa.gov/ghgreporting.
The EPA will make every effort to follow the schedule as closely as possible on the day of the hearing; however, please plan for the hearings to run either ahead of schedule or behind schedule.
Each commenter will have 5 minutes to provide oral testimony. The EPA encourages commenters to provide the EPA with a copy of their oral testimony electronically (via email) by emailing it to<EMAIL_ADDRESS>The EPA also recommends submitting the text of your oral testimony as written comments to the rulemaking docket.
The EPA may ask clarifying questions during the oral presentations but will not respond to the presentations at that time. Written statements and supporting information submitted during the comment period will be considered with the same weight as oral testimony and supporting information presented at the public hearing.
Please note that any updates made to any aspect of the hearing will be posted online at https://www.epa.gov/ghgreporting. While the EPA expects the hearing to go forward as set forth above, please monitor our website or contact us by email at<EMAIL_ADDRESS>to determine if there are any updates. The EPA does not intend to publish a document in the Federal Register announcing updates.
If you require the services of a translator or a special accommodation such as audio description, please pre-register for the hearing with the public hearing team and describe your needs by [INSERT DATE 7 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. The EPA may not be able to arrange accommodations without advanced notice.
Regulated Entities. These proposed revisions would affect certain entities that must submit annual greenhouse gas (GHG) reports under the GHGRP (40 CFR part 98). These are proposed amendments to existing regulations. If finalized, these amended regulations would also affect owners or operators of certain suppliers and direct emitters of GHGs. Regulated categories and entities include, but are not limited to, those listed in Table 1 of this preamble:
Table 1. Examples of Affected Entities by Category
                                   Category
                                     NAICS
                        Examples of affected facilities
General Stationary Fuel Combustion Sources
.........
Facilities operating boilers, process heaters, incinerators, turbines, and internal combustion engines.

211
Extractors of crude petroleum and natural gas.

321

Manufacturers of lumber and wood products.

322
Pulp and paper mills.

325
Chemical manufacturers.

324
Petroleum refineries, and manufacturers of coal products.

316, 326, 339
Manufacturers of rubber and miscellaneous plastic products.

331
Steel works, blast furnaces.

332
Electroplating, plating, polishing, anodizing, and coloring.

336
Manufacturers of motor vehicle parts and accessories.

221
Electric, gas, and sanitary services.

622
Health services.

611
Educational services.
Electric Power Generation
2211
Generation facilities that produce electric energy.
Ammonia Manufacturing
325311
Anhydrous and aqueous ammonia manufacturing facilities.
Cement Production
327310
Portland cement manufacturing plants.
Electronics Manufacturing
334111
Microcomputers manufacturing facilities.

334413
Semiconductor, photovoltaic (PV) (solid-state) device manufacturing facilities.

334419
Liquid crystal display (LCD) unit screens manufacturing facilities; Microelectromechanical (MEMS) manufacturing facilities.
Ferroalloy Production
331110
Ferroalloys manufacturing facilities.
Fluorinated Greenhouse Gas Production
325120
Industrial gases manufacturing facilities.
Glass Production
327211
Flat glass manufacturing facilities.

327213
Glass container manufacturing facilities.

327212
Other pressed and blown glass and glassware manufacturing facilities.
Hydrogen Production
325120
Hydrogen manufacturing facilities.
Iron and Steel Production
333110
Integrated iron and steel mills, steel companies, sinter plants, blast furnaces, basic oxygen process furnace (BOPF) shops.
Lime Manufacturing
327410
Calcium oxide, calcium hydroxide, dolomitic hydrates manufacturing facilities.
Miscellaneous Uses of Carbonate
Facilities included elsewhere
Petroleum and Natural Gas Systems
486210

Pipeline transportation of natural gas.

221210
Natural gas distribution facilities.

211120
Crude petroleum extraction.

211130
Natural gas extraction.
Petrochemical Production
325110
Ethylene dichloride manufacturing facilities.

325199
Acrylonitrile, ethylene oxide, methanol manufacturing facilities.

325110
Ethylene manufacturing facilities.

325180
Other basic inorganic chemical manufacturing.
Petroleum Refineries
324110
Petroleum refineries.
Silicon Carbide Production
327910
Silicon carbide abrasives manufacturing facilities.
Electrical Equipment Use
221121
Electric bulk power transmission and control facilities.
Underground Coal Mines
212113
Underground anthracite coal mining operations.

212112
Underground bituminous coal mining operations.
Zinc Production
331419
Primary zinc refining facilities

331492
Zinc dust recycling facilities, recovering from scrap and/or alloying purchased metals.

311411
Frozen fruit, juice, and vegetable manufacturing facilities.

311421
Fruit and vegetable canning facilities.
Municipal Solid Waste Landfills

562212
Solid waste landfills.

221320
Sewage treatment facilities.
Suppliers of Coal-based Liquid Fuels
211130
Coal liquefaction at mine sites.
Suppliers of Natural Gas and Natural Gas Liquids
221210
Natural gas distribution facilities.

211112
Natural gas liquid extraction facilities.
Suppliers of Petroleum Products
324110
Petroleum refineries.
Suppliers of Carbon Dioxide
325120
Industrial gas manufacturing facilities.
Suppliers of Industrial Greenhouse Gases
325120
Industrial greenhouse gas manufacturing facilities.
Electrical Equipment Manufacture or Refurbishment
33531
Power transmission and distribution switchgear and specialty transformers manufacturing facilities.
Carbon Dioxide Enhanced Oil Recovery Projects
211
Oil and gas extraction projects using carbon dioxide enhanced oil recovery.
Calcium Carbide Production
325180
Other basic inorganic chemical manufacturing.
Coke Calcining
324199
All other petroleum and coal products manufacturing
Glyoxal, Glyoxylic Acid, and Caprolactam Production
325199
All other basic organic chemical manufacturing.
Ceramics Manufacturing
327110
Pottery, ceramics, and plumbing fixture manufacturing.

327120
Clay building material and refractories manufacturing.

Table 1 of this preamble is not intended to be exhaustive, but rather provides a guide for readers regarding facilities likely to be affected by this proposed action. Other types of facilities than those listed in the table could also be subject to reporting requirements. To determine whether you would be affected by this proposed action, you should carefully examine the applicability criteria found in 40 CFR part 98, subpart A (General Provisions) and each source category. Many facilities that are affected by 40 CFR part 98 have greenhouse gas emissions from multiple source categories listed in Table 1 of this preamble.
Acronyms and Abbreviations. The following acronyms and abbreviations are used in this document.
AGA	American Gas Association
AIM	American Innovation and Manufacturing Act of 2020
AMLD	Advanced Mobile Leak Detection
ANOVA	analysis of variance
ANSI	American National Standards Institute
API	American Petroleum Institute
ASTM	American Society for Testing and Materials
BAMM	best available monitoring methods
BEF	by-product emission factor
BOEM	Bureau of Ocean Energy Management
BOPF	basic oxygen process furnace
C&D	construction and demolition
CAA	Clean Air Act
CARB 	California Air Resources Board
CBI	confidential business information
CBP	U.S. Customs and Border Protection
CCUS	carbon capture, utilization, and sequestration
CDA	clean dry air
CDC	Centers for Disease Control and Prevention
CEMS	continuous emission monitoring system
CFR	Code of Federal Regulations
CGA	cylinder gas audit
CF4	perfluoromethane
CH4	methane
CKD	cement kiln dust
CO2	carbon dioxide
CO2e	carbon dioxide equivalent
CO	carbon monoxide
COF2	carbonic difluoride
COVID-19	Coronavirus 2019
CSA	CSA Group
CVD	chemical vapor deposition
DAC	direct air capture
DCU	delayed coking unit
DOC	degradable organic carbon
DOT	Department of Transportation
DRE	destruction or removal efficiency
e-GGRT	electronic Greenhouse Gas Reporting Tool
EAF	electric arc furnace
EDC	ethylene dichloride
EF	emission factor
EG	emission guidelines
EIA	Energy Information Administration
EOR	enhanced oil recovery
EPA	U.S. Environmental Protection Agency
EREF	Environmental Research and Education Foundation
ET	Eastern time
FAQ	frequently asked question
FR	Federal Register
F-GHG	fluorinated greenhouse gas
F-HTFs	fluorinated heat transfer fluids
FTIR	Fourier Transform Infrared
GCS	gas collection system
GHG	greenhouse gas
GHGRP	Greenhouse Gas Reporting Program
GIE	gas-insulated equipment
GIS	geographic information systems
GOR	gas-to-oil ratio
GRI 	Gas Research Institute
GWP	global warming potential
HCFC	hydrochlorofluorocarbons
HFC	hydrofluorocarbons
HHV	high heating value
HTS	Harmonized Tariff System
HVAE	high voltage anode effect
IAI	International Aluminium Institute
ICR	Information Collection Request
IPCC	Intergovernmental Panel on Climate Change
IRC	Internal Revenue Code
IRS	Internal Revenue Service
ISBN	International Standard Book Number
ISO	International Standards Organization
IVT	Inputs Verification Tool
k	first order decay rate
kg	kilograms
LCA	life cycle analysis
LCD	liquid crystal display
LDC	local distribution company
LNG	liquified natural gas
LVAE	low voltage anode effect
MCF	moisture correction factor
MDEA	methyl diethanolamine
MEA	monoethanolamine
MEMS	microelectromechanical systems
mmBtu/hr	million British thermal units per hour
MMscf	million standard cubic feet
MRV	monitoring, reporting, and verification plan
MSHA	Mine Safety and Health Administration
MSW	municipal solid waste
mtCO2e	metric tons carbon dioxide equivalent
N2O	nitrous oxide
NAICS	North American Industry Classification System
NGL	natural gas liquids
NSPS	New Source Performance Standards
OAR	Office of Air and Radiation
OEM	original equipment manufacturer
OGI	optical gas imaging
OMB	Office of Management and Budget
OMP	operations management plan
PCA	Portland Cement Association
PFC	perfluorocarbon
PRA	Paperwork Reduction Act
ppmv	parts per million by volume
PV	photovoltaic
QA/QC	quality assurance/quality control
QMS	Quadrupole Mass Spectroscopy
RFA	Regulatory Flexibility Act
RMA	Rubber Manufacturers Association
RPC	remote plasma cleaning
RY	reporting year
scfh	standard cubic feet per hour
SF6	sulfur hexafluoride
SIA	Semiconductor Industry Association
SIC	Standard Industrial Classification System
SSM	startup, shutdown, and malfunction
TBD	to be determined
TFI	The Fertilizer Institute
TSCA	Toxic Substances Control Act
TSD	technical support document
UIC	underground injection control
U.S.	United States
UMRA	Unfunded Mandates Reform Act of 1995
USGS	U.S. Geological Survey
USTMA	U.S. Tire Manufacturers Association
VCM	vinyl chloride monomer
VOC	volatile organic compound
WMO	World Meteorological Organization
WWW	World Wide Web

TABLE OF CONTENTS
I. Background
A. How is this preamble organized?
B. Executive Summary
C. Background on this Proposed Rule
D. Legal Authority

II. Overview and Rationale for Proposed Amendments to 40 CFR Part 98 and 40 CFR Part 9
A. Revisions to Improve the Quality of Data Collected under Part 98 and Other Minor Revisions or Clarifications
B. Revisions to Streamline and Improve Implementation of Part 98
C. Revisions to 40 CFR Part 9

III. Proposed Amendments to Part 98
A. Subpart A  --  General Provisions
B. Subpart C  --  General Stationary Fuel Combustion Sources
C. Subpart G  --  Ammonia Manufacturing
D. Subpart H  --  Cement Production
E. Subpart I  --  Electronics Manufacturing
F. Subpart N  --  Glass Production
G. Subpart P  --  Hydrogen Production
H. Subpart Q  --  Iron and Steel Production
I. Subpart S  --  Lime Manufacturing
J. Subpart W  --  Petroleum and Natural Gas Systems
K. Subpart X  --  Petrochemical Production
L. Subpart Y  --  Petroleum Refineries
M.	Subpart BB  --  Silicon Carbide Production
N. Subpart DD  --  Electrical Transmission and Distribution Equipment Use
O. Subpart FF  --  Underground Coal Mines
P. Subpart GG  --  Zinc Production
Q. Subpart HH  --  Municipal Solid Waste Landfills
R. Subpart NN  --  Suppliers of Natural Gas and Natural Gas Liquids
S. Subpart OO  --  Suppliers of Industrial Greenhouse Gases
T. Subpart PP  --  Suppliers of Carbon Dioxide
U. Subpart SS  --  Electrical Equipment Manufacturers or Refurbishment
V. Subpart UU  --  Injection of Carbon Dioxide
W. Subpart VV  --  Geologic Sequestration of Carbon Dioxide with Enhanced Oil Recovery Using ISO 27916
IV. Additional Requests for Comment
A. Energy Consumption
B. Ceramics Manufacturing
C. Calcium Carbide Production
D. Glyoxal, Glyoxylic acid, and Caprolactam Production
E. Coke Calcining
F. CO2 Utilization
G. Aluminum Production

V. Schedule for the Proposed Amendments

VI. Proposed Confidentiality Determinations for Certain Data Reporting Elements
A. Overview and Background
B. Proposed Confidentiality Determinations
C. Proposed Reporting Determinations for Inputs to Emissions Equations
D. Request for Comments on Proposed Category Assignments, Confidentiality Determinations, or Determinations of Inputs to be Reported

VII. Impacts of the Proposed Amendments

VIII. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Act (RFA)
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 Risks and Safety Risks
H. Executive Order 13211: Actions 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. Determination under CAA Section 307(d)
I. Background
A. How is this preamble organized?
The first section of this preamble contains background information regarding the origin of the proposed amendments. This section also discusses the EPA's legal authority under the Clean Air Act (CAA) to promulgate (including subsequent amendments to) the Greenhouse Gas Reporting Rule, codified at 40 CFR part 98 (hereinafter referred to as "Part 98"), and the EPA's legal authority to make confidentiality determinations for new or revised data elements required by these amendments or for existing data elements for which a confidentiality determination has not previously been proposed. Section II of this preamble describes the types of amendments included in this proposed rulemaking and includes the rationale for each type of proposed change. Section III of this preamble is organized by Part 98 subpart and contains detailed information on the proposed revisions to Part 98 and the rationale for the proposed amendments in each section. Section IV of this preamble discusses additional requests for comments related to potentially expanding or adding new source categories and other potential future amendments to the GHG Reporting Rule. Section V of this preamble discusses when the proposed revisions to Part 98 would apply to reporters. Section VI of this preamble discusses the proposed confidentiality determinations for new or substantially revised (i.e., requiring additional or different data to be reported) data reporting elements, as well as for certain existing data elements for which a determination has not been previously established. Section VII of this preamble discusses the impacts of the proposed amendments. Section VIII of this preamble describes the statutory and executive order requirements applicable to this action.
B. Executive Summary
The EPA is proposing amendments to Part 98 to implement improvements to the GHGRP. After more than 10 years of implementation of the program, the EPA has assessed the data collected, emissions, and trends established from annual reports in each industrial sector required to report. In this review, the EPA has evaluated the requirements of the GHGRP to identify areas of improvement, such as where the rule may be modified to reflect the EPA's current understanding of United States (U.S.) GHG emission trends, or to improve data collection and reporting where additional data may be necessary to better understand emissions from specific sectors or inform future policy decisions. The EPA has subsequently identified improvements to the calculation, monitoring, and reporting requirements that would incorporate new data or updated scientific knowledge; reflect new emissions sources; improve analysis and verification of collected data; provide additional data to complement or inform other EPA programs; or streamline calculation, monitoring, or reporting to provide flexibility or increase the efficiency of data collection.
The proposed amendments include improvements to requirements that would enhance the quality of the data collected, clarify elements of the rule, and streamlining changes. The types of proposed amendments that would improve the quality of the data collected under the rule include revisions to update emission factors to more accurately reflect industry emissions; refinements to existing emissions calculation methodologies to reflect an improved understanding of emissions sources and end uses of GHGs; providing for collection of additional data to understand new source categories or new emission sources for specific sectors; additions or modifications to reporting requirements in order to eliminate data gaps and improve verification of emissions estimates; revisions that address prior commenter concerns or clarify requirements, and editorial corrections that would improve the public's understanding of the rule.
The types of streamlining changes that the EPA is proposing include revisions to applicability for certain industry sectors to account for changes in usage of certain GHGs or where the current applicability estimation methodology may overestimate emissions; revisions that provide flexibility for or simplify monitoring and calculation methods; and revisions to streamline reported data elements or recordkeeping where the current requirements are redundant, where reported data are not currently useful for verification or analysis, or for which continued collection of the data at the same frequency would not likely provide new insights or knowledge of the industry sector, emissions, or trends at this time.
This action also includes a request for comment related to potentially expanding existing categories or including additional new source categories to the Greenhouse Gas Reporting Rule. In these cases, the EPA is seeking additional information to better inform our consideration of proposing these new source categories to the GHGRP. Therefore, the EPA is specifically requesting comment related to the potential expanded or new source categories described in this section. The EPA is also requesting comment on potential future amendments to add new calculation, monitoring, and reporting requirements for the aluminum production source category. If the Agency becomes comfortable that the information available is sufficient to support a rule revision, the EPA may consider undertaking a future action to revise or add source categories or to incorporate updated calculation and reporting requirements.
Further, this action includes a proposal to update 40 CFR part 9 in accordance with the publication requirements of the PRA to include the OMB control number issued under the PRA for the information collection request (ICR) for the GHGRP.
Finally, this action proposes to establish and/or revise confidentiality determinations for the reporting of certain data elements added or revised in these proposed amendments, and for certain existing data elements for which no confidentiality determination has been previously proposed, or for which we are proposing to amend a previously established confidentiality determination.
Most of the changes that are proposed are not anticipated to significantly increase the recordkeeping and reporting burden associated with the GHGRP. The proposed changes are anticipated to improve the quality of the data reported under the program. Some of the proposed revisions could potentially increase burden in cases where the proposed amendments add or revise reporting requirements. The estimated incremental costs include an average burden of $1,424,775 per year beginning in reporting year (RY) 2023.
The EPA anticipates that the proposed changes may take effect on January 1, 2023 and would apply beginning with reports submitted for RY2023, which are required to be submitted to the EPA by April 1, 2024.
C. Background
The GHG Reporting Rule was published in the Federal Register (FR) on October 30, 2009 (74 FR 56260) (hereafter referred to as the 2009 Final Rule). The 2009 Final Rule became effective on December 29, 2009 and requires reporting of GHGs from various facilities and suppliers, consistent with the 2008 Consolidated Appropriations Act. The EPA issued additional rules in 2010 finalizing the requirements for subpart T (Magnesium Production), subpart FF (Underground Coal Mines), subpart II (Industrial Wastewater Treatment), and subpart TT (Industrial Waste Landfills) (75 FR 39736, July 12, 2010); subpart W (Petroleum and Natural Gas Systems) (75 FR 74458, November 30, 2010); subpart I (Electronics Manufacturing), subpart L (Fluorinated Gas Production), subpart DD (Electrical Transmission and Distribution Equipment Use), subpart QQ (Importers and Exporters of Fluorinated GHGs Contained in Pre- Charged Equipment or Closed-Cell Foams), and subpart SS (Electrical Equipment Manufacture or Refurbishment) (75 FR 74774, December 1, 2010); and subpart RR (Geologic Sequestration of Carbon Dioxide) and subpart UU (Injection of Carbon Dioxide) (75 FR 75060, December 1, 2010). Following the promulgation of these subparts, the EPA finalized several technical and clarifying amendments to these and other subparts under the GHGRP (75 FR 79092, December 17, 2010; 76 FR 22825, April 25, 2011; 76 FR 36339, June 22, 2011; 76 FR 59533, September 27, 2011; 76 FR 59542, September 27, 2011; 76 FR 73866, November 29, 2011; 76 FR 80554, December 23, 2011; 77 FR 10373, February 22, 2012; 77 FR 48072, August 13, 2012; 77 FR 51477, August 24, 2012; 78 FR 25392, May 1, 2013; 78 FR 68162, November 13, 2013; 78 FR 71904, November 29, 2013; 79 FR 63750, October 24, 2014; 79 FR 70352, November 25, 2014; 79 FR 73750, December 11, 2014; 80 FR 64262, October 22, 2015; and 81 FR 86490, November 30, 2016). The amendments generally added or revised requirements in the existing subparts of Part 98, including revisions that were intended to improve clarity and consistency across the calculation, monitoring, and data reporting requirements. The EPA finalized additional amendments (81 FR 89188, December 6, 2016) to streamline implementation of the rule, to improve the quality and consistency of the data collected under the rule, and to clarify or provide updates to certain provisions that have been the subject of questions from reporting entities. The EPA is proposing additional amendments and requesting comment in a continuation of the effort to improve the GHGRP.
D. Legal Authority
The EPA is proposing these rule amendments under its existing CAA authority provided in CAA section 114. As stated in the preamble to the 2009 Final Rule (74 FR 56260), CAA section 114(a)(1) provides the EPA broad authority to require the information proposed to be gathered by this rule because such data would inform and are relevant to the EPA's carrying out of a wide variety of CAA provisions. See the preambles to the proposed GHG Reporting Rule (74 FR 16606, October 10, 2009) and the 2009 Final Rule for further information.
II. Overview and Rationale for Proposed Amendments to 40 CFR Part 98 and 40 CFR Part 9
Since 2010, the GHGRP has been a reliable and high-quality source of GHG data. The data collected under Part 98 is used to inform the EPA's understanding of the relative emissions and distribution of emissions from specific industries, the factors that influence GHG emission rates, and to inform policy options and potential regulations. The data published under the GHGRP also serves to enable key stakeholders to understand, track, and compare greenhouse gas emissions and identify and take action on emission reduction opportunities. Further, the data collected under the GHGRP has also been used to inform other regulations, for example, proposed New Source Performance Standards (NSPS) and Emission Guidelines for the oil and gas industry and for municipal solid waste (MSW) landfills under 40 CFR part 60.
Throughout the life of the GHGRP, the EPA has made several improvements to the rule to address data gaps, reflect updates to scientific information, or to incorporate improvements to calculation, monitoring, or measurement methodologies. For example, in 2013, the EPA finalized technical amendments including changes to applicability, improvements to calculation methods, and updated reporting requirements, as well as amendments to incorporate new data from the Intergovernmental Panel on Climate Change (IPCC) on estimated global warming potentials (GWPs) (78 FR 71904, November 29, 2013). More recently, the EPA finalized edits to the petroleum and natural gas systems source category to address potential gaps in coverage, improve methods, and ensure high quality data reporting (81 FR 86490, November 30, 2016). The EPA last updated the GHGRP in 2016, when it implemented revisions to streamline and improve implementation of the rule and to improve the quality of the data collected, including expanding monitoring and reporting requirements that were necessary to improve verification and served to improve the accuracy of the data used to inform the Inventory of U.S. Greenhouse Gas Emissions and Sinks (hereafter referred to as the "U.S. GHG Inventory") (81 FR 89188, December 9, 2016).
The EPA has also continuously conducted outreach to stakeholders through various means, including responding to questions from reporters, engaging through compliance assistance webinars, soliciting feedback via a public testing process, interacting with reporters during the verification of submitted data, and soliciting comments during rulemakings. Thus, the EPA has subsequently identified, proposed, and finalized several technical and clarifying amendments to various subparts under the GHGRP to enhance the quality of the data reported, improve our understanding of GHG emission sources and trends, and improve implementation, particularly where we have identified changes to industry processes, emissions trends, types of emissions sources, or new data or scientific knowledge that would allow us to better understand the quantity and distribution of U.S. GHG emissions.
The EPA recently evaluated the requirements of the GHGRP to identify areas of improvement, such as where the rule may be modified to reflect the EPA's current understanding of U.S. GHG emission trends, or to improve data collection and reporting where additional data may be necessary to better understand emissions from specific sectors or inform future policy decisions. The proposed amendments include improvements to the calculation, monitoring, and reporting requirements that would incorporate updates to existing emissions estimation methodologies; implement requirements to collect additional data to understand new source categories or new emission sources for specific sectors; improve the EPA's understanding of the sector-specific processes or other factors that influence GHG emission rates and improve verification of collected data; and provide additional data to complement or inform other EPA programs. We are also proposing revisions that clarify or update provisions that have been unclear. The proposed amendments include:
Amendments to update emission factors to incorporate new measurement data that more accurately reflects industry emissions;
Revisions to refine existing emissions calculation methodologies to reflect an improved understanding of emissions sources and end uses of GHGs, or to incorporate more recent research on GHG emissions or formation;
Revisions to specific sectors to expand reporting to include new source categories or new emission sources, in order to improve the accuracy and completeness of the data provided by the GHGRP;
Adding or modifying reporting requirements to eliminate data gaps and improve verification of emissions estimates; and
Revisions that address prior commenter concerns or provide additional information for reporters to better or more fully understand their compliance obligations, that clarify requirements that reporters have previously found vague to ensure that accurate data are being collected, and editorial corrections or harmonizing changes that would improve the public's understanding of the rule.
The EPA is also soliciting additional comment on potentially expanding existing subparts or adding other new subparts to collect data for several new source categories, as well as requesting comment on potential future amendments to add new calculation, monitoring, and reporting requirements for the aluminum production source category, as discussed in section IV of this preamble.
The EPA has also identified additional areas in the GHGRP where revisions to Part 98 could be streamlined. Through this notice, the EPA is proposing several amendments to revise specific provisions in Part 98 that would streamline calculation, monitoring, or reporting to provide flexibility or increase the efficiency of data collection. The types of revisions we are proposing would simplify requirements while maintaining the quality of the data collected under Part 98, where continued collection of information assists in evaluation and support of EPA programs and policies. The proposed revisions include:
Revisions to applicability for certain industry sectors without the 25,000 metric tons carbon dioxide equivalent (mtCO2e) per year reporting threshold to account for changes in usage of certain GHGs, or where the current applicability estimation methodology may overestimate emissions;
Providing flexibility for and simplifying monitoring and calculation methods where further monitoring and data collection would not likely significantly improve our understanding of emission sources at this time, or where we currently allow similar less burdensome methodologies for other sources; and
Revisions to streamline reported data elements or recordkeeping where the current requirements are redundant or where reported data are not currently useful for verification or analysis, or for which continued collection of the data at the same frequency would not likely provide new insights or knowledge of the industry sector, emissions, or trends at this time.
Sections II.A and II.B of this preamble describe the above changes in more detail and provide rationale for the changes included in each category. Additional details for the specific amendments proposed for each subpart are included in section III of this preamble. We are seeking public comment only on the proposed revisions and issues specifically identified in this document for the identified subparts. We expect to deem any comments received addressing other aspects of 40 CFR part 98 to be outside of the scope of this proposed rulemaking.
Finally, we are also proposing a technical amendment to 40 CFR part 9 to update the table that lists the OMB control numbers issued under the PRA to include the ICR for Part 98. This amendment is described in section II.C of this preamble.
A. Revisions to Improve the Quality of Data Collected under Part 98 and Other Minor Revisions or Clarifications
The data collected under Part 98 are used to inform the EPA's understanding of the relative emissions and distribution of emissions from specific industries, the factors that influence GHG emission rates, and to inform policy options and potential regulations. Following several years of implementation and outreach, the EPA has identified certain areas of the rule where updates to emissions factors or other default factors; improvements to calculation methodologies; collection of additional data on GHG emissions, emissions sources, or end uses; additions or revisions to data elements or other reporting requirements; and other technical amendments, clarifications, and corrections would enhance the quality and accuracy of the data collected under the GHGRP. These proposed changes include consideration of comments raised by stakeholders in prior rulemakings that would more closely align rule requirements with the processes conducted at specific facilities, consideration of data gaps identified in collected data where additional data would improve verification of data reported to the GHGRP, and consideration of additional data needed to help better understand changing industry emission trends. Overall, these proposed changes would provide a more comprehensive, nationwide GHG emissions profile reflective of the origin and distribution of GHG emissions in the United States and would more accurately inform EPA policy options for potential regulatory or non-regulatory CAA programs. The EPA additionally uses the data from the GHGRP, which would include data from these proposed changes, to improve estimates used in the U.S. GHG Inventory.
In some cases, we are proposing to redefine certain industry sectors to include additional GHGs not previously reported, or to add emissions estimations methodologies and include reporting of GHGs from newly identified sources of emissions in certain industry sectors, to better account for changes in industry emission trends. The proposed amendments reflect adjustments to the rule where we have identified changes in the type and scope of GHGs emitted or supplied, such as certain sectors that have implemented alternative equipment technology, switched to use of GHGs with a lower GWP, or that have implemented new end uses for GHGs that are emitted or supplied. In other cases, we have identified gaps in the current coverage of the GHGRP that leave out potentially significant emission sources, for example, large, atypical release events at oil and gas facilities such as wellhead leaks. The proposed amendments would also add a new source category that would provide additional data on amounts of CO2 that are geologically sequestered in association with EOR operations. Many of the revisions proposed in this action would better capture the changing landscape of greenhouse gas emissions and provide for more complete coverage of U.S. GHG emission sources. Such changes are necessary for the EPA to continue to analyze the relative emissions and distribution of emissions from specific industries and to improve the overall quality of the data collected under the GHGRP. These changes would also complement other EPA regulations, such as NSPS and emission guidelines (EG) for the oil and gas industry and would also be used to inform and improve future policy decisions.
The specific changes that we are proposing, as described in this section, are described in detail for each subpart in sections III.A through III.W of this preamble.
1. Updates to Emission Factors to Improve Accuracy of Reported Data
In order to improve the accuracy of the data collected under the GHGRP, we are proposing to revise emission factors where we have received improved measurement data or feedback from stakeholders. Some of the calculation methodologies provided in the GHGRP rely on the use of emission factors, and the use of emissions or default factors decreases the need for additional monitoring or measurements from individual facilities. The proposed rule includes revisions to emission factors in a number of source categories, where we have received or identified updated measurement data. For example, we are proposing several updates to the emission factors and default destruction and removal efficiency values in subpart I (Electronics Manufacturing). The proposed emission factors are based on review of newly submitted data from the 2017 and 2020 technology assessment reports submitted with RY2016 and RY2019 annual reports, as well as consideration of new emission factors available in the 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (hereafter "2019 Refinement"). We are also proposing updates to the emission factor calculation methods that are used to calculate utilization and by-product emission rates submitted in the technology assessment report under subpart I, in order to ensure that emission factors are developed in a consistent manner across facilities and over time and to allow the EPA to compare emission factors across the industry and track trends in industry emission rates.
In some cases, the proposed emission factors would improve reported data by better reflecting recent industry trends. For example, based on input from stakeholders, we are proposing updated emission factors for the modeling of methane (CH4) generation from waste disposed at landfills in subpart HH (Municipal Waste Landfills). The updated emission factors reflect an industry trend of increased disposal of inert materials that do not contribute to CH4 generation. The EPA received data from stakeholders in the waste industry following comments received during the expert and public review period for the U.S. GHG Inventory, which uses directly reported emissions values from subpart HH to estimate national CH4 emissions from MSW landfills throughout the entire United States. The proposed change will update default factors and will result in more accurate estimates of landfill emissions and pose no additional reporting burden.
We are also proposing to update the default biogenic fraction for tire combustion in subpart C (General Stationary Fuel Combustion) and the emission factors for natural gas pneumatic devices and for equipment leaks from natural gas distribution sources (including pipeline mains and services, below grade transmission-distribution transfer stations, and below grade metering-regulating stations) and equipment at onshore petroleum and natural gas production and onshore petroleum and natural gas gathering and boosting facilities in subpart W (Petroleum and Natural Gas Systems). The proposed emission factors are more representative of GHG emissions sources and would improve the overall accuracy of the data collected under the GHGRP and would ultimately benefit stakeholders who rely on GHGRP data to understand the sources and magnitude of GHGs from specific facilities, as well as improve the quality of data used to inform future policy or regulation.
2. Improvements to Existing Emissions Estimation Methodologies
We are proposing several revisions to modify calculation equations to incorporate refinements to methodologies based on an improved understanding of emission sources. In some cases, we have become aware of discrepancies between assumptions in the current emission estimation methods and the processes or activities conducted at specific facilities, where the proposed revisions would reduce reporter errors. In other cases, we are proposing to revise the emissions estimation methodologies to incorporate recent studies on GHG emissions or formation that reflect updates to scientific understanding of GHG emissions sources. The proposed changes will improve the quality and accuracy of the data collected under the GHGRP, increase our understanding of the relative distribution of GHGs that are emitted, and better reflect GHG end uses or where GHGs are bound in products.
For example, for subpart I, we are proposing several edits to the stack testing methodology, including adding new equations and a table of default weighting factors to calculate the fraction of fluorinated input gases and by-products exhausted from tools with abatement systems; revising equations that calculate the weighted average DREs for individual fluorinated greenhouse gases (F-GHGs) across process types; requiring that all stacks be tested if the stack test method is used; and updating a set of equations that will more accurately account for emissions when pre-control emissions of a F-GHG approach or exceed the consumption of that gas during the test period.
For other subparts, including subparts G (Ammonia Manufacturing), P (Hydrogen Production), and S (Lime Manufacturing), we are proposing revisions to the calculation methodology to allow for subtraction of carbon dioxide (CO2) that is captured and bound in other products (e.g., urea or methanol) from calculated and reported emissions. The proposed changes, by removing the CO2 that is not directly emitted from these facilities from the calculation methodology, would provide a more accurate estimate of the direct sector emissions and would provide consistency in our approach across the GHGRP.
For subpart Y (Petroleum Refineries), we are proposing to amend the calculation methodology for delayed coking units (DCUs), which uses a steam generation model to estimate emissions. The proposed changes are targeted to address issues identified during verification of reported data, where we have noticed that the activities conducted at certain facilities do not comport with some of the underlying assumptions of the steam generation model. The proposed changes will modify the current equation to more accurately estimate emissions and to be more universally applicable to these facilities.
Additional details of these types of proposed changes are discussed in section III of this preamble.
3. Revisions to Address Potential Gaps in Reporting of Emissions Data for Specific Sectors
We are proposing several amendments to include reporting of additional emissions or emissions sources for specific sectors to address potential gaps in reporting. We are also proposing to improve the existing rule requirements by proposing new or revised calculation, monitoring, or reporting requirements that would help us to better understand and track emissions in specific sectors; establish requirements for a new source category for quantifying geologic sequestration of CO2 in association with EOR operations; and identify end uses of GHGs that are not currently accounted for in existing reporting, for consideration in future policy development. Such data would continue to inform, and are relevant to, the EPA's carrying out a wide variety of CAA provisions. For example, identifying new emissions or new emission sources from direct emitters could inform decisions about whether and how to use section 111 of the CAA to establish NSPS for various source categories emitting GHGs. The data may also inform the EPA's implementation of section 103(g) of the CAA regarding improvements in nonregulatory strategies and technologies for preventing or reducing air pollutants. The data published under the GHGRP serves to enable the Agency and stakeholders to understand, track, and compare greenhouse gas emissions and identify emission reduction opportunities. Over the last 10 years, the collection of these data has allowed the Agency and relevant stakeholders to identify changes in industry and emissions trends, such as transitions in equipment technology or use of alternative lower-GWP greenhouses gases, that may be beneficial for informing other EPA programs under the CAA. The amendments we are proposing are intended to address data gaps that have been identified in the implementation of the program or from review of improved scientific assessments and would allow the EPA to better characterize U.S. GHG emissions. The improved data would subsequently better inform other agency policies and programs under the CAA.
For example, we are proposing several revisions to subparts DD (Electrical Transmission and Distribution Equipment Use) and SS (Electrical Equipment Manufacture or Refurbishment) to improve the quality of the data collected from these industrial sectors. Currently, these subparts include "all electric transmission and distribution equipment and servicing inventory" used within an electric power system, and related manufacturing and refurbishing processes, that use or include sulfur hexafluoride (SF6) and perfluorocarbons (PFCs). At the time of the 2010 final rule, SF6 was the most commonly used insulating gas in the electrical power industry, and PFCs were occasionally used as dielectrics and heat transfer fluids in power transformers. During the implementation of the reporting program, electrical power systems equipment manufacturers and fluorinated greenhouse gas suppliers have introduced alternative technologies and replacements for SF6 with lower GWPs, including fluorinated gas mixtures. We are proposing to revise the existing calculation, monitoring, and reporting requirements of these subparts to require reporting of additional F-GHGs, in order to better track emissions from equipment using alternative gases that are not currently accounted for.
Additionally, we have become aware of potentially significant sources of emissions in specific industry sectors for which there are no current emission estimation methods within Part 98. For example, under subpart I, we are proposing a calculation methodology to estimate emissions of perfluoromethane (CF4) from hydrocarbon-based emissions control systems. The proposed changes reflect recent studies that have shown that direct reaction between molecular fluorine (F2) and hydrocarbons to form CF4 can occur in hydrocarbon-fueled combustion emissions control systems, and we are proposing to incorporate calculations from the 2019 Refinement to account for the formation and emission of CF4 from this potentially significant emissions source.
For subpart W, we are proposing to add calculation methodologies and requirements to report GHG emissions for several additional sources. We are proposing to add a new emissions source, referred to as "other large release events," to capture abnormal emission events that are not accurately accounted for using existing methods in subpart W. This additional source would cover events such as storage wellhead leaks, well blowouts, and other large, atypical release events and would apply to all types of facilities subject to subpart W. Reporters would calculate GHG emissions using measurement data or engineering estimates of the amount of gas released and measurement data, if available, or process knowledge (best available data) to estimate the composition of the released gas. We are also proposing to require reporting of existing emission sources by additional industry segments. For example, we are proposing to require liquified natural gas (LNG) import/export facilities to begin calculating and reporting emissions from acid gas removal vents.
In other cases, we are proposing changes to improve our understanding of end-uses of GHGs and to better understand GHG supply. For subpart OO (Suppliers of Industrial Greenhouse Gases), we are proposing to require suppliers of nitrous oxide (N2O), saturated PFCs, and SF6 to identify the end uses for which the N2O, SF6, or PFC is used, and the quantities of N2O, SF6, or each PFC transferred to each end use. This requirement would help to inform the development of GHG policies and programs by providing information on N2O, SF6, and PFC uses and their relative importance, where the GWP-weighted quantities of these compounds that are supplied annually to the U.S. economy are relatively large, and where the identities and magnitudes of the uses of these compounds are less well understood.
The EPA is also proposing revisions to incorporate a new source category to add calculation and reporting requirements for quantifying geologic sequestration of CO2 in association with EOR operations. The proposed requirements would be included under a new subpart VV and would apply to reporters that choose to use the International Standards Organization (ISO) standard designated as CSA Group (CSA)/American National Standards Institute (ANSI) ISO 27916:2019, Carbon Dioxide Capture, Transportation and Geological Storage -- Carbon Dioxide Storage Using Enhanced Oil Recovery (CO2-EOR) (hereafter referred to as "CSA/ANSI ISO 27916:2019") as a means of quantifying geologic sequestration. We are proposing to add this new source category because collecting additional information from these sources would improve our knowledge on the amounts of CO2 that are geologically sequestered in association with EOR operations and allow the Agency to better track and document the flow of CO2 through the economy to better inform EPA policy and programs under the CAA. The proposed requirements are discussed in section III.W of this preamble.
The proposed changes would improve the overall quality and completeness of the data collected by the GHGRP, and would be useful for informing future policy decisions, such as opportunities to reduce emissions. The EPA is also soliciting additional comment on potential collection of data under other new source categories, as discussed in section IV of this preamble.
4. Revisions to Reporting Requirements to Improve Verification and the Accuracy of the Data Collected
The EPA is proposing several revisions to existing reporting requirements to improve the quality of the data that are currently reported, or to collect more useful data that would improve verification of reported data. Such revisions would better characterize U.S. GHG emissions and trends and would better enable the EPA to obtain data that is of sufficient quality that it can be used to support a range of future climate change policies and regulations, including but not limited to information relevant to carrying out provisions involving research, evaluating and setting standards, endangerment determinations, or informing EPA non-regulatory programs.
For example, we are proposing revisions to the reporting of unit level information under subpart C. Currently, individual unit information (i.e., the unit type and the maximum rated heat input capacity) is only required to be reported for specific individual unit reporting configurations. The individual unit information allows the EPA to aggregate emissions according to unit type and size and provides a better understanding of the emissions from specific unit types. To improve verification and analysis of reported data, the EPA is proposing to require reporting of certain unit level information for each unit in an aggregation of units or common pipe configuration, excluding units less than 10 million British thermal units per hour (mmBtu/hr).
Under subpart H (Cement Production) and subpart S, we are proposing to collect additional data elements where the EPA has little data on which to build verification checks. For these subparts, we are proposing to collect annual averages of chemical composition input data on a facility-basis. The proposed data elements would assist the EPA in verification of continuous emission monitoring systems (CEMS) facility emissions. Because CEMS facilities typically include combustion and process emissions that are vented through the same stack, process and combustion emissions are usually mixed and indifferentiable. By collecting average chemical composition data, the EPA would be able to compare and differentiate process emissions from CEMS facilities. Such additions to reporting would improve the accuracy of the emissions data and render such information more valuable and useful.
For subpart W, we are proposing to add or revise reporting requirements to better understand and characterize the emissions for several emission sources. For example, we are proposing to collect additional information from facilities with liquids unloadings to differentiate between manual and automated unloadings.
Additionally, under subpart GG (Zinc Production), the EPA is proposing that facilities report the total amount of electric arc furnace (EAF) dust annually consumed by all Waelz kilns at the facility. In this case, because the amount of EAF dust consumed in Waelz kilns is strongly correlated with CO2 emissions, the proposed data element would serve as a useful data validation point and could potentially be used for the future development of an emission factor.
The proposed revisions to add new reporting requirements would also extend the usefulness of GHGRP data to improve the EPA's ability to carry out other CAA programs. For example, we are proposing under subpart HH to require MSW landfills to report data on the landfill CH4 emissions that are destroyed versus sent to landfill gas energy projects. This information would additionally help inform the development of GHG policies and programs by providing information on the amount of recovered CH4 that is beneficially used in energy recovery projects and would inform the EPA, as well as state and local government officials, on progress towards renewable energy targets, and would also be useful to other stakeholders. As discussed in prior amendments, the GHGRP is also intended to supplement and complement the U.S. GHG Inventory and other EPA programs by advancing the understanding of emission processes and monitoring methodologies for particular source categories or sectors. The GHGRP also provides data from individual facilities and suppliers above certain thresholds, which can additionally be used to improve the assumptions and emissions values used in the U.S. GHG Inventory (see 81 FR 2546, January 15, 2016). The facility, unit, and process level GHG emissions data for industrial sources collected under the GHGRP does not replace the system in place to produce the top-down U.S. GHG Inventory, but can be additionally used to improve the accuracy of the U.S. GHG Inventory by confirming the national statistics and emission estimation methodologies. Therefore, the EPA periodically reviews the data from the GHGRP to consider whether there are data that are useful to the GHGRP and that would also improve the accuracy of the data included in the U.S. GHG Inventory or improve our ability to inform the development of GHG policies and programs. We are proposing several amendments that would improve the data collected by the GHGRP, and subsequently, would provide data that would benefit and support the U.S. GHG Inventory. For example, we are proposing to revise the current requirements for subpart N (Glass Production) facilities to require reporting the annual quantities of glass produced by glass type. In general, the emissions profile of a specific glass type is relatively consistent with the composition of the glass, based on the major raw materials (limestone, dolomite, and soda ash). Collecting data on annual production by glass type would improve verification for the GHGRP by allowing the EPA to compare emissions by glass types produced and would also provide useful information to improve analysis of this sector in the U.S. GHG Inventory.
5. Technical Amendments, Clarifications, and Corrections
We are proposing other technical amendments, corrections, and clarifications that would improve understanding of the rule. These revisions primarily include revisions of requirements to better reflect the EPA's intent or editorial changes. Some of these proposed changes result from consideration of questions raised by reporters through the GHGRP Help Desk or electronic Greenhouse Gas Reporting Tool (e-GGRT) and are intended to resolve uncertainties in the regulatory text. For example, we are proposing amendments in several subparts that would clarify requirements that have led to reporter uncertainty, such as reported data elements that may be unclear and misread by reporters. In several cases, these provisions may have introduced uncertainty into the rule and resulted in reporting that is inconsistent with the rule requirements. The proposed clarifications would reduce the uncertainty associated with certain reported data elements and increase the likelihood that reporters will submit accurate reports the first time. For example, we are proposing a revision to subpart Y to resolve the potential discrepancy between the flare emission calculations at 40 CFR 98.253(b), which requires that all gas discharged through the flare stack must be included in the calculations except for pilot gas, and the requirements at 40 CFR 98.253(b)(1)(iii), which excludes startup, shutdown, and malfunction (SSM) events less than 500,000 standard cubic feet per day (scf/day) from Equation Y-3. As another example, under subpart W, the EPA is proposing to clarify the calculation of emissions from open thief hatches on atmospheric storage tanks that use vapor recovery systems and flares, by revising 40 CFR 98.233(j)(4) and (5) to specify how to account for those emissions. The EPA's intent is that reporters should be including emissions from open thief hatches, but the current rule does not provide explicit provisions for them. We are also proposing to revise 40 CFR 98.236(j)(1) to clarify reporting of emissions from atmospheric storage tanks with vapor recovery systems and flares. These proposed clarifications and corrections would also reduce the burden associated with reporting, data verification, and EPA review. Additional details of these types of proposed changes are discussed in section III of this preamble.
Other minor changes being proposed include correction edits to fix typos, minor clarifications such as adding a missing word, harmonizing changes to match other proposed revisions, reordering of paragraphs so that a larger number of paragraphs need not be renumbered, and others as reflected in the draft proposed redline regulatory text in the docket for this rulemaking (Docket Id. No. EPA-HQ-OAR-2019-0424).
B. Revisions to Streamline and Improve Implementation of Part 98
Since 2010, the EPA has collected data through the GHGRP to assess industry emissions, and has, through review of annually submitted data, gained substantial knowledge of the types, quantities, and distribution of emissions across industry sectors. Through this process, the EPA has engaged in stakeholder outreach, solicited feedback, responded to questions from reporters, and identified site specific scenarios or issues that could impact the quality of the data reported. In a recent review of the requirements of the program, we have identified several areas of Part 98 that could be revised or simplified to reduce technical challenges associated with implementation or improve the efficiency of the requirements, while maintaining the quality of the data collected. We are subsequently proposing several revisions that would streamline the calculation, monitoring, and reporting burden associated with the rule.
The specific changes that we are proposing that are intended to streamline Part 98, as described in this section, are described in detail for each subpart in sections III.A through III.W of this preamble.
1. Revisions to Applicability for Certain Industry Sectors
We are proposing to change the applicability criteria for three subparts to account for changes in usage of certain GHGs, or where the current applicability estimation methodology may overestimate emissions. The proposed changes would improve the estimation methodologies used to determine applicability for specific subparts and more accurately focus GHGRP and reporter resources on coverage of large industrial emitters within these sectors; such changes are in keeping with our goal to maximize coverage and collection of GHG emissions data from each sector while excluding small emitters.
Currently, any facility that contains a source category listed in Table A-3 of subpart A of Part 98 (General Provisions) is subject to reporting under Part 98 (referred to as "all-in" source categories because reporting applies regardless of other source category or stationary fuel combustion emissions at the facility). Table A-3 defines a few of the "all-in" source categories using thresholds that use metrics other than mtCO2e of emissions. A facility that contains a source category listed in Table A-4 of subpart A of Part 98 must report only if estimated annual emissions from all applicable source categories in Tables A-3 and Table A-4 of Part 98 are 25,000 mtCO2e or more (referred to as "threshold" source categories). The EPA has used the "threshold" approach where a source category contains emitters with a range in emissions quantity and the EPA wants to capture those facilities within the source category with larger total emissions from multiple process units or collocated source categories that emit significant levels of GHGs collectively, and not burden smaller emitters with a reporting obligation. The EPA has used the "all-in" approach for industries for which all facilities are emitters of a similar quantity or to gather data on certain industries to identify the parameters that influence GHG emissions from the source category.
The EPA used alternative metrics for some subparts in Table A-3 for a variety of reasons. In some cases, the metric provides a more straightforward way for facilities within that source category to evaluate their applicability. For example, for subpart DD (Electrical Transmission and Distribution Equipment), the metric is based on the total nameplate capacity of SF6 and PFC-containing equipment and was approximated as equivalent to the 25,000 metric tons of CO2 threshold. To ensure that the GHGRP data collected better reflects the current electrical power system industry, we are proposing to remove the existing nameplate capacity threshold, and instead provide a calculation method for facilities to estimate total annual GHG emissions for comparison to the 25,000 metric tons of CO2 threshold. These changes align with proposed changes to redefine the source category to include equipment containing "fluorinated GHGs (F-GHGs), including but not limited to sulfur-hexafluoride (SF6) or and perfluorocarbons (PFCs)", and reflect that some facilities within the industry sector have begun to use lower GWP F-GHGs, which is not reflected when using only the nameplate capacity of the equipment to determine applicability. The proposed changes would establish an updated comparison to the threshold and would account for additional fluorinated gases (including F-GHG mixtures) used in industry.
Similarly, we are proposing to revise the threshold for subpart SS (Electrical Equipment Manufacture or Refurbishment), which is based on total annual purchases of SF6 and PFCs. As with subpart DD, we are proposing to revise the existing requirements of subpart SS to require reporting of additional F-GHGs beyond SF6 and PFCs, and we are proposing to revise the subpart SS threshold to align with these changes. The proposed changes would continue to be based on the total annual purchases of F-GHGs but would establish a calculation method for comparison to the 25,000 metric tons of CO2 threshold, and would better account for the additional fluorinated gases (including F-GHG mixtures) reported by industry.
We are also proposing revisions to provide a second option for an alternative calculation methodology, that is consumption-based, that reporters subject to subpart I (Electronics Manufacturing) could use to determine whether they meet the emissions threshold for reporting applicability. For subpart I (Electronics Manufacturing), the current provisions of 40 CFR 98.91 require facilities to estimate whether the 25,000 mtCO2e threshold is met based on emissions estimates assuming the facility operates at its annual manufacturing capacity, which may result in significant over-estimation of emissions. The capacity-based methodology has required reporting by some electronics manufacturing facilities that use smaller amounts of F-GHGs. For subpart I, the method for determining the applicability was chosen to reduce the burden on low-emitting facilities by providing a simplified method to estimate emissions for the purpose of assessing applicability. However, for subpart I, the applicability threshold provisions may currently require certain lower-emitting facilities to report where the capacity-based estimation methodology overestimates emissions. We are proposing to revise the applicability estimation methodology in subpart I to provide a second option for an alternative calculation method using a gas-consumption basis, and to use updated emission factors, so that facilities may choose instead to use a separate method that more accurately calculates potential facility emissions.
We are proposing to revise the applicability of these subparts to more accurately estimate facility emissions and to more accurately focus GHGRP and reporter resources on the collection of data for the larger industrial emitters within these sectors. These changes would continue to maximize coverage of GHG emissions data from the sector while excluding small emitters. The proposed revisions would also adjust the applicability provisions for each of these subparts for consistency across Part 98. The proposed changes to subparts I, DD, and SS are described in sections III.E, III.N, and III.U of this preamble.
2. Revisions to Streamline Monitoring and Calculation Methodologies
We are proposing revisions to provide flexibility for or simplify some calculation methods or monitoring requirements. We are proposing options to revise monitoring requirements in instances where we currently allow a less burdensome methodology for similar emissions sources; or where continuing to collect the data on the same frequency would be unlikely to provide significantly different values.
In some cases, we are proposing amendments that would add flexibility to the calculation methods to add less burdensome options that would correspond with a decrease in actual data collection. These types of proposed changes would simplify monitoring for reporters without impacting the quality of the data reported. For example, for subpart Y (Petroleum Refineries), we are proposing to allow the use of mass spectrometer analyzers to determine gas composition and molecular weight without the use of a gas chromatograph. The proposed revisions would allow reporters to use the same analyzers used for process control or for compliance with continuous sampling required under the National Emissions Standards for Hazardous Air Pollutants from Petroleum Refineries (40 CFR part 63, subpart CC) to comply with the GHGRP requirements in subpart Y. Currently, these reporters must conduct separate periodic sampling of these gas streams for analysis using gas chromatography to comply with GHGRP requirements in subpart Y, and the proposed revisions would provide flexibility for and reduce burden for these reporters.
In some cases, we are proposing to clarify and streamline calculation methodologies where there is uncertainty regarding the use of the calculation method. For example, for subpart W (Petroleum and Natural Gas Systems), we are proposing to revise the definition of the Onshore Natural Gas Processing industry segment so that reporters have more certainty regarding the industry segment and calculation methods that are applicable from the beginning of the year. The current definition of the Onshore Natural Gas Processing industry segment includes processing plants that fractionate gas liquids and processing plants that do not fractionate gas liquids but have an annual average throughput of 25 million standard cubic feet (MMscf) per day or greater. Processing plants that do not fractionate gas liquids and have an annual average throughput of less than 25 MMscf per day may be part of a facility in the Onshore Petroleum and Natural Gas Gathering and Boosting industry segment. Processing plants that do not fractionate gas liquids and generally operate close to the 25 MMscf per day threshold do not know until the end of the year whether they will be above or below the threshold, so they must be prepared to report under whichever industry segment is ultimately applicable. The two potentially applicable segments report emissions from different sources and with different calculation methods. For example, facilities in the Onshore Natural Gas Processing industry segment are not required to report emissions from atmospheric storage tanks and are required to measure leaks from individual compressors, while facilities in the Onshore Petroleum and Natural Gas Gathering and Boosting industry segment are required to report emissions from atmospheric storage tanks but may use emission factors to calculate emissions from compressors rather than conducting measurements. Therefore, we are revising the Onshore Natural Gas Processing industry segment definition in 40 CFR 98.230(a)(3) to remove the 25 MMscf per day threshold and more closely align subpart W with the definitions of natural gas processing in other rules (e.g., 40 CFR part 60, subpart OOOOa). This proposed revision to the Onshore Natural Gas Processing industry segment definition would make it clear to reporters whether a processing plant would be classified as an Onshore Natural Gas Processing facility or as part of an Onshore Petroleum and Natural Gas Gathering and Boosting facility, and the applicable segment would not have the potential to change from one year to the next simply based on the facility throughput.
Additional details of these types of proposed changes may be found in section III of this preamble.
3. Revisions to Streamline or Revise Recordkeeping and Reporting Requirements
Other proposed revisions to the rule include changes that would streamline the rule, such as revising certain reporting and recordkeeping requirements that are redundant or no longer being used, or that would remove duplicative reporting across EPA programs. For example, for subpart C (General Stationary Fuel Combustion Sources), we are proposing to amend certain provisions in 40 CFR 98.36 that require facilities with the aggregation of units or common pipe configuration types to report the total annual CO2 mass emissions from the combustion of all fossil fuels combined. In this case, the reported configuration-level annual CO2 emissions from all fossil fuels does not factor into any subpart- or facility-level total CO2 emission calculations and is not integrated into e-GGRT's programmed "roll up" of emissions. Because we can adequately verify reports and interpret and analyze the reported data without these data elements, they are currently redundant and would not likely provide new insights or knowledge of the industry sector, emissions, or trends at this time.
In some cases, we are proposing to correct inconsistencies in the current rule. Under subpart Y, we are proposing a change to correct an inconsistency introduced by the amendments to the DCU calculations published on December 9, 2016 (81 FR 89188). Although the prior amendments removed the option to calculate CH4 emissions from DCUs using the process vent method, the associated recordkeeping requirements for the process vent method were inadvertently not removed from the rule. Therefore, we are therefore proposing to remove the associated recordkeeping requirements.
For subpart W, we are proposing to revise reporting requirements related to atmospheric pressure fixed roof storage tanks receiving hydrocarbon liquids that follow the methodology specified in 40 CFR 98.233(j)(3) and Equation W-15. The calculation methodology uses population emission factors and the count of applicable separators, wells, or non-separator equipment to determine the annual total volumetric GHG emissions at standard conditions. The associated reporting requirements in 40 CFR 98.236(j)(2)(i)(E) through (F) require reporters to delineate the counts used in Equation W-15. Based on feedback from reporters, the EPA has determined that the reporting requirements are inconsistent with the language used in the calculation methodology and are not inclusive of all equipment to be included. Therefore, we are proposing to revise the reporting requirements to better align the requirement with the calculation methodology and streamline the requirements for all facilities reporting atmospheric storage tanks emissions using the methodology in 40 CFR 98.233(j)(3).
In some cases, we are streamlining reporting by removing duplicative reporting elements within or across GHGRP subparts. For example, we are proposing to eliminate duplicative reporting between subpart NN (Suppliers of Natural Gas and Natural Gas Liquids) and subpart W where both subparts require similar data elements to be reported to e-GGRT. For instance, for natural gas liquids (NGL) fractionators, both subpart W (under the Onshore Natural Gas Processing segment) and subpart NN require reporting of the volume of natural gas received and the volume of NGL received. The proposed amendments would limit the reporting of these data elements to facilities that do not report under subpart NN, thus removing the duplicative requirements from subpart W for facilities that report to both subparts. This will streamline reporting and reduce the burden on reporters.
We are also proposing to reduce the frequency of reporting information that we anticipate will not change on a frequent basis, such as the data collected for technology assessment reports under subpart I (Electronics Manufacturing). Based on the data collected in the initial technology assessment reports (currently required by 40 CFR 98.96(y)), we do not anticipate significant variations in these data elements within a three-year period going forward, as discussed in section III.E.2 of this preamble. Further, we are proposing several significant improvements to the technology assessment reports that will improve the usefulness and quality of the data provided in the reports. The proposed improvements would allow the EPA to collect these data less frequently while continuing to provide the EPA with updates to the gases and technologies used in semiconductor manufacturing.
Additional details of these types of proposed changes may be found in section III of this preamble.
C. Revisions to 40 CFR Part 9
The EPA is proposing a related change to update 40 CFR part 9 to include the OMB control number issued under the PRA for the ICR for the GHGRP. The OMB control numbers for EPA regulations in Title 40 of the CFR (after appearing in the Federal Register) are listed in 40 CFR part 9 and are included on the related collection instrument or form, if applicable. The EPA is proposing to amend the table in 40 CFR part 9 to list the OMB approval number under which the ICR for activities in the existing Part 98 regulations that were previously approved by OMB have been consolidated. The prior approvals are included in OMB No. 2060-0629; OMB No. 2060-0629 has not previously been added to 40 CFR part 9 due to an oversight. This listing of the OMB control number and the subsequent codification in the CFR would correct this oversight and satisfy the display requirements of the PRA and OMB's implementing regulations at 5 CFR part 1320. III. Proposed Amendments to Part 98
This section summarizes the specific substantive amendments proposed for each subpart, as generally described in section II of this preamble.
A. Subpart A  --  General Provisions
1. Proposed Revisions to Improve the Quality of Data Collected for Subpart A
In this action, we are proposing several revisions to subpart A of Part 98 (General Provisions). For the reasons described in section II.A.5 of this preamble, we are proposing to clarify in 40 CFR 98.2(i)(1) and (2) that the provision to allow cessation of reporting or "off-ramping," due to meeting either the 15,000 mtCO2e level or the 25,000 mtCO2e level for the number of years specified in 40 CFR 98.2(i), is based on the CO2e reported, calculated in accordance with 40 CFR 98.3(c)(4)(i) (i.e., the annual emissions report value as specified in that provision). The proposed changes clarify that reporters must rely on the emissions estimation methodologies used to report emissions and their annual emissions report totals to determine their ability to off-ramp. We are also proposing to clarify the off-ramp provisions at 40 CFR 98.2(i)(1) and (2) to specify that after an owner or operator off-ramps, the owner or operator must use Equation A-1 and follow the requirements of 40 CFR 98.2(b)(4) in subsequent years to determine if emissions exceed the 25,000 mtCO2e applicability threshold and whether the facility or supplier must resume reporting. The requirements of 40 CFR 98.2(b) are different from the requirements of 40 CFR 98.3(c) in that the applicability determination requires more flexible calculation methods (e.g., facilities may use any subpart C tier to estimate combustion emissions on 40 CFR 98.2(b), whereas they must follow the applicable subpart C tier to calculate combustion emissions under 40 CFR 98.3(c)). The proposed revisions make clear that reporters who have previously off-ramped would continue to follow the emission estimation methods used for determination of applicability to determine if they must resume reporting.
We are also proposing to revise 40 CFR 98.2(f)(1) to clarify how to calculate GHG quantities for comparison to the 25,000 mtCO2e threshold for importers and exporters of industrial greenhouse gases; the proposed changes specify that the calculation must include the fluorinated heat transfer fluids (F-HTFs) that are imported or exported during the year. In the December 9, 2016 final rule, 2015 Revisions and Confidentiality Determinations for Data Elements Under the Greenhouse Gas Reporting Rule (81 FR 89234), the EPA expanded the definition of the source category for importers and exporters of industrial greenhouse gases to include facilities that destroy 25,000 mtCO2e or more of industrial F-GHGs or F-HTFs annually, and entities that produce, import, or export F-HTFs that are not also F-GHGs. It was our intent that suppliers of F-HTFs be subject to the same thresholds. However, we inadvertently neglected to update 40 CFR 98.2(f) to include F-HTFs in the calculation requirements. Similarly, we are proposing to add a new paragraph (k) to 40 CFR 98.2, specifying how to calculate the quantities of F-GHGs and F-HTFs destroyed for purposes of comparing them to the 25,000 mtCO2e threshold for stand-alone industrial F-GHG or F-HTF destruction facilities. This paragraph was inadvertently omitted when the rule was revised to cover stand-alone destruction facilities in 2016. The proposed changes would clarify that imported, exported, and destroyed F-HTFs and F-GHGs must be calculated and included when determining applicability.
We are also proposing new paragraph 40 CFR 98.4(n) that would apply in lieu of 40 CFR 98.4(h) for changes in the owner or operator of a facility in the four industry segments in subpart W (Petroleum and Natural Gas Systems) that have unique definitions of facility: Onshore Petroleum and Natural Gas Production; Onshore Petroleum and Natural Gas Gathering and Boosting; Natural Gas Distribution; and Onshore Natural Gas Transmission Pipeline. For these industry segments, particularly Onshore Petroleum and Natural Gas Production and Onshore Petroleum and Natural Gas Gathering and Boosting, asset transactions between owners and operators can involve only some emission sources at the facility rather than the entire facility. In those cases, reporters have submitted numerous questions to the e-GGRT Help Desk requesting guidance regarding which owner or operator should report for the year in which the transaction occurred as well as which owner or operator is responsible for submitting revisions and responding to questions from the EPA regarding previous annual GHG reports. To address some of these questions, the EPA previously developed Frequently Asked Questions (FAQ) Q749. However, neither the FAQ nor the existing requirements in subpart A explicitly explain the responsibilities for the situations for which reporters have requested guidance.
Therefore, the EPA is proposing to add specific provisions to subpart A that would define which owner or operator is responsible for current and future reporting years' reports and clarify how to determine responsibility for revisions to annual reports for reporting years prior to owner or operator changes for specific industry segments in subpart W, beginning with RY2023 reports. The provisions would also specify when an owner or operator should submit an annual report using an e-GGRT identifier assigned to an existing facility and when an owner or operator should register a new facility in e-GGRT. As described in more detail in this section, the provisions would vary based upon whether the selling owner or operator will retain any emission sources, the number of purchasing owners or operators, and whether the purchasing owners or operators already report to the GHGRP in the same industry segment and basin or state (as applicable). The proposed provisions would apply in lieu of 40 CFR 98.4(h) for these industry segments. These proposed revisions are expected to improve data quality as described in section II.A.4 of this preamble by ensuring that the EPA receives a more complete data set, and they are also expected to improve understanding of the rule, as described in section II.A.5 of this preamble.
We expect all the transactions will fall into one of four general categories, and we are proposing provisions that would define the responsibilities for reporting for each of those general categories. First, if the entire facility is sold to a single purchaser and the purchasing owner or operator does not already report to the GHGRP in that industry segment (and basin or state, as applicable), then we are proposing that the facility's certificate of representation must be updated within 90 days of the transaction to reflect the new owner or operator. In other words, the e-GGRT identifier and associated facility within e-GGRT would be transferred from the seller to the purchaser. The purchasing owner or operator would be responsible for submitting the facility's annual report for the entire reporting year in which the acquisition occurred (i.e., the owner or operator as of December 31 would be responsible for the report for that entire reporting year) and each reporting year thereafter. In addition, because the definitions of facility for each of these segments encompass all of the emission sources in a particular geographic area (i.e., basin, state, or nation), the purchasing owner or operator would include any previously owned applicable emission sources in the same geographic area as part of the purchased facility beginning with the reporting year in which the acquisition occurred.
Second, if the entire facility is sold to a single purchaser and the purchasing owner or operator already reports to the GHGRP in that industry segment (and basin or state, as applicable), then we are proposing that the purchasing owner or operator would merge the acquired facility with their existing facility for purposes of reporting under the GHGRP. In other words, the acquired facility would become part of the purchaser's existing facility under the GHGRP and emissions for the combined facility would be reported under the e-GGRT identifier for the purchaser's existing facility. The purchaser would update the acquired facility's certificate of representation within 90 days of the transaction to reflect the new owner or operator. The purchaser would then follow the provisions of 40 CFR 98.2(i)(6) to notify the EPA that the purchased facility has merged with their existing facility and would provide the e-GGRT identifier for the merged, or reconstituted, facility. Finally, the purchaser would be responsible for submitting the merged facility's annual report for the entire reporting year in which the acquisition occurred (i.e., the owner or operator as of December 31 would be responsible for the report for that entire reporting year) and each reporting year thereafter.
Third, if the selling owner or operator retains some of the emission sources and sells the other emission sources of the seller's facility to one or more purchasing owners or operators, we are proposing that the selling owner or operator would continue to report under subpart W for the retained emission sources unless and until that facility meets one of the criteria in 40 CFR 98.2(i) and complies with those provisions. Each purchasing owner or operator that does not already report to the GHGRP in that industry segment (and basin or state, as applicable) would begin reporting as a new facility for the entire reporting year beginning with the reporting year in which the acquisition occurred. The new facility would include the acquired applicable emission sources as well as any previously owned applicable emission sources. Each purchasing owner or operator that already reports to the GHGRP in that industry segment (and basin or state, as applicable) would add the acquired applicable emission sources to their existing facility for purposes of reporting under subpart W and would be responsible for submitting the annual report for their entire facility, including the acquired emission sources, for the entire reporting year beginning with the reporting year in which the acquisition occurred.
Fourth, if the selling owner or operator does not retain any of the emission sources and sells all of the facility's emission sources to more than one purchasing owner or operator, we are proposing that the selling owner or operator for the existing facility would notify the EPA within 90 days of the transaction that all of the facility's emission sources were acquired by multiple purchasers. The purchasing owners or operators would begin submitting annual reports for the acquired emission sources for the reporting year in which the acquisition occurred following the same provisions as in the third scenario. In other words, each owner or operator would either begin reporting their acquired applicable emission sources as a new facility or add the acquired applicable emission sources to their existing facility.
Finally, for all of these types of transactions, we are proposing one set of provisions to clarify responsibility for annual GHG reports for reporting years prior to the reporting year in which the acquisition occurred. This set of proposed provisions would apply to annual GHG reports for facilities where these types of transactions occur after the effective date of the final amendments, if adopted. In other words, if the effective date of the final amendments is January 1, 2023, as described in section V of this preamble, then for ownership transactions that occur on or after January 1, 2023, we are proposing that the proposed requirements for the current and future reporting years described in the previous paragraphs would apply. In addition, the proposed provisions for annual GHG reports for reporting years prior to the transaction would also apply. For example, if an ownership transaction occurs on June 30, 2025, then the selling owner or operator and purchasing owner or operator would follow the applicable provisions previously described in this section for the RY2025 report and for future reporting years. We are also proposing that the provisions described in the next paragraph would apply for RY2024 and prior years' reports.
Specifically, we are proposing that as part of each ownership transaction described previously in this section, the selling owner or operator and purchasing owner or operator would agree upon the entity that would be responsible for revisions to annual GHG reports for previous reporting years. That entity would then select a representative for each facility that would respond to any EPA questions regarding GHG reports for previous reporting years and would submit corrected versions of GHG reports for previous reporting years as needed. If that individual is not the designated representative for the facility, the individual would need to be appointed as the alternate designated representative or an agent for the facility. In many situations, particularly for the first two categories of transactions described in this section, the EPA expects that the purchaser would agree to select a representative to address revisions to previous years' annual GHG reports. In addition, there may be cases in which the selling owner or operator's company will no longer be operating after the transaction, so it may be appropriate for one of the purchasing owners or operators to select that representative. In other situations, the parties may determine that it is appropriate for the seller to select the representative to address revisions to annual GHG reports for reporting years prior to the reporting year in which the acquisition occurred. Alternatively, parties to the transaction may agree on another independent party that would act as the representative regarding annual GHG reports for previous reporting years, such as a consultant. The EPA expects that the decision regarding the responsible entity would be made as part of the acquisition agreement or ownership transfer contract between the selling owner or operator and purchasing owner or operator and that if the entity responsible for revisions to annual GHG reports is not the selling owner or operator, copies of the records required to be retained per 40 CFR 98.3(g) and (h) would be transferred to the responsible entity at that time.
We are also proposing to amend 40 CFR 98.1(c) to clarify that the terms "owner" and "operator" used in subpart A have the same meaning as the terms "gathering and boosting system owner or operator" and "onshore natural gas transmission pipeline owner or operator" for the Onshore Petroleum and Natural Gas Gathering and Boosting and Onshore Natural Gas Transmission Pipeline industry segments of subpart W, respectively. This paragraph was inadvertently not amended when those two industry segments and the industry segment-specific definitions of owner or operator were added to subpart W (80 FR 64275, October 22, 2015), and this proposed amendment would correct that oversight.
In addition, we are proposing to revise 40 CFR 98.3(h)(4) to limit the total number of days a reporter can request to extend the time period for resolving a substantive error either by submitting a revised report or providing information demonstrating that the previously submitted report does not contain the substantive error. According to 40 CFR 98.3(h) a substantive error may either be identified by the EPA or discovered by the facility itself. If discovered by the facility, a revised report correcting the error must be submitted within 45 days. If identified by the EPA, once the facility is notified of the error, the facility must either resubmit the corrected report or provide information demonstrating that the previously submitted report does not contain the identified substantive error within 45 days. The rule also states that if requested in either case, the EPA may provide reasonable extensions to the 45-day period, including an automatically granted extension of 30 days. Additional extensions may be granted if the facility submits a request that is received prior to the expiration of the automatic 30-day extension. The current rule states that the Administrator will approve the additional extension request if the request demonstrates that it is not practicable to collect and process the data needed to resolve potential reporting errors within 75 days. However, since the GHGRP was implemented, we have encountered instances where a facility has repeatedly requested an extension of the time period by which they must either submit a revised report or provide information that the previously submitted report does not contain a substantive error. As such, the EPA cannot verify the facility's report in a timely manner. To avoid such instances in the future, we are proposing to add to 40 CFR 98.3(h)(4) that the Administrator will only approve extension requests for a total of 180 days from the initial notification of a substantive error. We expect that 180 days is a reasonable amount of time for a facility to examine company records, gather additional data, and/or perform recalculations to submit a revised report or provide the necessary information such that the report may be verified.
The EPA is also proposing revisions to two terms consistent with the proposed amendments for reporting for glycol dehydrators with an annual average daily natural gas throughput greater than or equal to 0.4 MMscf per day described in section III.J of this preamble. The EPA is proposing to amend the definition of "dehydrator vent emissions" in 40 CFR 98.6 to confirm that dehydrator emissions reporting should include emissions from both the dehydrator still vent, and if applicable, the dehydrator flash vent. Additionally, the EPA is proposing to amend the definition of "vapor recovery system" in 40 CFR 98.6 to clarify that routing emissions from a dehydrator vent to the regenerator firebox/fire tubes does not qualify as vapor recovery. The EPA has noted significant variability in the dehydrator emissions values reported over the past several years, with values ranging from extremely high to almost negligible emissions, which indicates that there are likely inconsistencies in how these terms are being interpreted among subpart W reporters. In making these clarifying edits, the EPA expects to improve the quality of the emissions data reported and alleviate any confusion surrounding the applicability of these terms.
As a corollary to proposed amendments to subpart W to remove desiccant dehydrators as an emissions source, we are proposing to remove the definition of "desiccant" and to revise the definition of "dehydrator" in 40 CFR 98.6. The definition of "desiccant" would no longer be needed if the emission calculation and reporting requirements for desiccant dehydrators are removed from subpart W, as discussed in section III.J of this preamble. Similarly, the definition of "dehydrator" would no longer need to include a reference to desiccant. Thus, we are proposing to revise the definition of "dehydrator" to indicate that a dehydrator is "a device in which a liquid absorbent (e.g., ethylene glycol, diethylene glycol, or triethylene glycol) directly contacts a natural gas stream to absorb water vapor."
We are proposing revisions to 40 CFR 98.6 to add a definition for "Direct air capture" and amend the definition of "Carbon dioxide stream". These proposed changes are being made in conjunction with other proposed revisions to subpart PP of Part 98 (Suppliers of Carbon Dioxide) and are discussed in section III.T of this preamble.
In addition, we are proposing two harmonizing changes to 40 CFR 98.7 to incorporate by reference American Society for Testing and Materials (ASTM) method E415-17, Standard Test Method for Analysis of Carbon and Low-Alloy Steel by Spark Atomic Emission Spectrometry (2017) for subpart Q (Iron and Steel Production) and CSA/ANSI ISO  27916:2019, Carbon Dioxide Capture, Transportation and Geological Storage  -- Carbon Dioxide Storage Using Enhanced Oil Recovery (CO2-EOR) for proposed subpart VV (Geologic Sequestration of Carbon Dioxide with Enhanced Oil Recovery Using ISO 27916). These proposed changes are further described in sections III.H and III.W of this preamble.
Lastly, we are proposing two updates to Table A-1, the list of GWPs used in the GHGRP, to revise GWPs that, based on recent information, overestimate the atmospheric impacts of certain compounds by a large margin (i.e., by factor of 2,000). We are not proposing any other updates to the Table A-1 GWPs. First, we are proposing to adopt a chemical-specific GWP for carbonic difluoride (COF2). Emissions of COF2 of 1-2 metric tons per year have been reported under the GHGRP from fluorinated gas production. (Carbonic difluoride is also used in the electronics industry as an etching agent and surface treatment, although emissions of COF2 from electronics manufacturing have not been reported under the GHGRP). No peer-reviewed, chemical-specific GWP was available for COF2 in 2014, when we last updated the set of GWPs in Table A-1 (79 FR 73750, December 11, 2014). It is therefore currently classified as an "Other fluorinated GHG" and is assigned a default GWP of 2,000 under the GHGRP. However, the World Meteorological Organization (WMO) recently published an atmospheric lifetime, radiative efficiency, and GWP for COF2 in its Scientific Assessment of Ozone Depletion (2018). Like the IPCC Assessment Reports upon which the GWPs in Table A-1 are based, the WMO Scientific Assessments include regularly updated international reviews of the scientific findings on the impacts of trace gases in the atmosphere, including their atmospheric lifetimes and radiative efficiencies. According to the 2018 WMO Scientific Assessment, COF2 has a lifetime of approximately seven days, and 20-year and 100-year GWPs of less than one. The 2018 WMO Scientific Assessment listed the 100-year GWP of COF2 as "<1," so we calculated and are proposing a precise GWP for COF2 of 0.14 using the atmospheric lifetime and radiative efficiency provided in the 2018 WMO Scientific Assessment. (The method we used to calculate the GWP of COF2 was the method we used to calculate precise GWPs for low-GWP compounds in the most recent update to GHGRP GWPs (79 FR 73750, December 11, 2014)). This recent information supports that including a chemical-specific GWP for COF2 of 0.14 would reflect its atmospheric impacts far more accurately than the currently applied GHGRP default GWP of 2,000.
Second, we are proposing to expand one of the F-GHG groups to which a default GWP of 1 is applied to include additional unsaturated fluorocarbons. The ninth F-GHG group in Table A-1 to subpart A currently includes unsaturated PFCs, unsaturated HFCs, unsaturated hydrochlorofluorocarbons (HCFCs), unsaturated halogenated ethers, unsaturated halogenated esters, fluorinated aldehydes, and fluorinated ketones. We are proposing to add unsaturated bromofluorocarbons, unsaturated chlorofluorocarbons, unsaturated bromochlorofluorocarbons, unsaturated hydrobromofluorocarbons, and unsaturated hydrobromochlorofluorocarbons to this set. These F-GHGs do not have chemical-specific GWPs in Table A-1, and facilities and suppliers that currently report these F-GHGs generally classify them as "Other fluorinated GHGs," which are assigned a default GWP of 2,000. However, two lines of evidence indicate that unsaturated bromofluorocarbons, unsaturated chlorofluorocarbons, unsaturated bromochlorofluorocarbons, unsaturated hydrobromofluorocarbons, and unsaturated hydrobromochlorofluorocarbons are likely to have GWPs near 1. First, like many of the types of compounds currently included in the ninth F-GHG group, they are unsaturated (i.e., they include double and triple bonds between carbon atoms), and unsaturated GHGs in general tend to have very short atmospheric lifetimes and GWPs near or below 1. Second, evaluations of individual unsaturated chlorofluorocarbons and unsaturated bromofluorocarbons have all found very short atmospheric lifetimes and (where assessed) low GWPs for these compounds. The 2018 WMO Scientific Assessment provides atmospheric lifetimes for three unsaturated chlorofluorocarbons and four unsaturated bromofluorocarbons, and it provides an atmospheric lifetime and a 100-year GWP for one unsaturated bromochlorofluorocarbon (4-bromo-3-chloro-3,4,4-trifluoro-1-butene). All of the atmospheric lifetimes are under 8 days, and the 100-year GWP is listed as "<1." Therefore, the EPA's assessment is that, due to their short atmospheric lifetimes, unsaturated bromofluorocarbons, unsaturated chlorofluorocarbons, unsaturated bromochlorofluorocarbons, unsaturated hydrobromofluorocarbons, and unsaturated hydrobromochlorofluorocarbons are likely to have a GWP near 1 (the default GWP for the ninth F-GHG group) rather than 2,000 (the default GWP for "Other Fluorinated GHGs"). The EPA is proposing to add these additional unsaturated fluorocarbons to the ninth F-GHG group to result in more accurate estimation of the reported mtCO2e.
We are proposing to incorporate a harmonizing change based on the addition of a new source category for quantifying geologic sequestration in association with EOR operations. Specifically, we are proposing to add the  new subpart, subpart VV (Geologic Sequestration of Carbon Dioxide with Enhanced Oil Recovery Using ISO 27916), in Table A-3 to subpart A.
As discussed in section III.W of this preamble, facilities that conduct EOR currently have the option to either report basic information on CO2 received under subpart UU (Injection of Carbon Dioxide), or report CO2 sequestered under subpart RR (Geologic Sequestration of Carbon Dioxide). Facilities that conduct EOR are not required to report under subpart RR unless the owner or operator chooses to opt-in to subpart RR, or the well is permitted as a Underground Injection Control (UIC) Class VI well. We are proposing that facilities that use the standard Carbon Dioxide Capture, Transportation and Geological Storage  -- Carbon Dioxide Storage Using Enhanced Oil Recovery (CO2-EOR) (CSA/ANSI ISO 27916:2019) for quantifying geologic sequestration of CO2 in association with EOR operations would similarly have the option to report under the proposed subpart VV instead of subpart UU. Facilities that conduct EOR would therefore have two options to report amounts of CO2 that are geologically sequestered: subpart RR or subpart VV.
We are proposing to include the new subpart VV in Table A-3 to subpart A. In addition, we are proposing that this new subpart would not include a reporting threshold for applicability. The EPA previously promulgated subparts RR and UU with no threshold (i.e., as "all-in" source categories in Table A-3 to subpart A) due to variability in CO2 injection amounts from year to year and based on limited knowledge of which EOR reporters that are not required to report under subpart RR would choose to report geologic sequestration (see 75 FR 18454, April 10, 2010 and 75 FR 75070, December 1, 2010). The facilities affected by the proposed subpart include facilities that are currently reporting under subpart UU and that do not currently report amounts of CO2 sequestered. The EPA is proposing no threshold for the proposed subpart VV so that all EOR facilities that quantify CO2 sequestration using the CSA/ANSI ISO 27916:2019 standard and that do not report under subpart RR would have the option to either report under the proposed subpart VV, or would otherwise continue to report under subpart UU. For these reasons, we do not anticipate that the new subpart would increase the number of facilities subject to the GHGRP. Further, it is difficult to predict how many injection facilities would choose to report using the ISO standard in lieu of continuing to report under subpart UU. Therefore, we are proposing that subpart VV would be an "all-in" reporting subpart in order to allow the Agency to continue to comprehensively track all CO2 that is injected underground, and to remain consistent with the "all-in" requirements for EOR or injection facilities that currently report under subparts RR or UU. Reporters who choose to report under this subpart would be required to meet the requirements of 40 CFR 98.2(a)(1). However, as proposed in new 40 CFR 98.480(c), facilities subject only to new subpart VV would not be required to report emissions under subpart C or any other subpart listed in 40 CFR 98.2(a)(1) or (a)(2), consistent with the requirements for the existing facilities under subpart UU.
Additionally, we are proposing that facilities subject to proposed subpart VV would not be required to meet the off-ramp requirements of 40 CFR 98.2(i). Instead, once a facility opts-in to proposed subpart VV, the owner or operator must continue for each year thereafter to comply with all requirements of the subpart, including the requirement to submit annual reports, until the facility demonstrates termination of the CO2-EOR project following the requirements of CSA/ANSI ISO 27916:2019. The EPA is proposing that the operator notify the Administrator of its intent to cease reporting and provide a copy of the CO2-EOR project termination documentation prepared for CSA/ANSI ISO 27916:2019. See section III.W of this preamble for additional details on the proposed revisions.
2. Proposed Amendments to Streamline and Improve Implementation for Subpart A
For the reasons described in sections II.B.1, III.N, and III.U of this preamble, we are proposing harmonizing edits in subpart A of Part 98 to revise the rule applicability for subparts DD (Electrical Transmission and Distribution Equipment Use) and subpart SS (Electrical Equipment Manufacture or Refurbishment). The proposed applicability threshold for subparts DD and SS would be based on total emissions equivalent to the 25,000 mtCO2e or more per year, rather than the current threshold levels that are based on the total nameplate capacity of the equipment or the annual consumption, respectively. For subpart DD, we are proposing to revise Table A-3 such that the threshold is based on total estimated emissions from F-GHGs, as determined under 40 CFR 98.301 (subpart DD), that are equivalent to 25,000 mtCO2e or more per year. For subpart SS, we are proposing to revise Tables A-3 and Tables A-4 such that: (1) subpart SS would be removed from Table A-3; and (2) Table A-4 would be revised to specify that subpart SS facilities would be included in 40 CFR 98.2(a)(2) and Table A-4, as determined under the requirements of 40 CFR 98.451 (subpart SS), which provide estimation methods for total estimated emissions from F-GHGs for comparison to a threshold equivalent to 25,000 mtCO2e or more per year. Refer to sections III.N and III.U of this preamble for a detailed discussion of these proposed changes and how the proposed new thresholds would be implemented. The proposed revisions are intended to harmonize Tables A-3 and A-4 with the proposed changes described in sections II.B.1, III.N, and III.U of this preamble, which would update the threshold to be consistent with the threshold set for the majority of subparts and would account for additional fluorinated gases (including F-GHG mixtures) reported by industry, and for subpart DD, would also streamline the reporting requirements to focus Agency resources on the substantial emission sources within the sector by excluding facilities or operations that may report emissions that are consistently and substantially below 25,000 mtCO2e per year (see section IV.C ("Rationale for Selection of Thresholds") of the preamble to the 2009 Proposed Rule (74 FR 16467, April 10, 2009)).
B. Subpart C  --  General Stationary Fuel Combustion Sources
1. Proposed Revisions to Improve the Quality of Data Collected for Subpart C
We are proposing several amendments to improve the quality of the data collected under subpart C of Part 98 (General Stationary Fuel Combustion Sources). This section describes the specific changes proposed.
First, for the reasons provided in section II.A.2 of this preamble, we are proposing to modify the Tier 3 calculation methodology in subpart C. Reporters to subpart C may use the Tier 3 methodology provided in 40 CFR 98.33(a)(3) for determining annual CO2 emissions from combustion units. The Tier 3 methodology requires a calculation based on annual fuel use, measured carbon content, and for gaseous fuels, measured molecular weight. For gaseous fuels, Equation C-5 at 40 CFR 98.33(a)(3)(iii) requires that the carbon content and molecular weight be in units of kilogram (kg) C/kg fuel and kg/kg-mole, respectively, and be determined using the same procedures as specified for high heating value (HHV) at 40 CFR 98.33(a)(2)(ii). However, when using Equation C-2b at 40 CFR 98.33(a)(2)(ii)(A) in this manner, the fuel carbon content is on a mass basis (i.e., kg C/kg fuel) while the fuel flow is on a volumetric basis (i.e., scf), resulting in a weighting factor that is potentially problematic because the units of measure are not in equivalent terms, i.e., the average annual carbon content should be in mass terms (i.e., kg C/kg fuel). When using Equation C-2b for calculating an annual flow-weighted molecular weight, a similar situation occurs. This has been the case since the 2009 Final Rule (74 FR 56397).
To address this matter, the EPA is proposing to modify the Tier 3 calculation methodology in 40 CFR 98.33(a)(3)(iii) to provide new Equations C-5a and C-5b for calculating a weighted annual average carbon content and a weighted annual average molecular weight. respectively. These new proposed equations incorporate the molar volume conversion factor at standard conditions (as defined at 40 CFR 98.6) and for annual average carbon content, the measured molecular weight of the fuel, in order to convert the fuel flow to the appropriate units of measure. This proposed change will correct the calculation method for Tier 3 gaseous fuels. The EPA does not expect a significant change in reported emissions because the change to the values for carbon content and molecular weight is expected to be minimal under the proposed calculation methods. Additionally, some reporters have previously exercised the option to manually override the calculated emission values with their own calculated values to address this issue when it has been identified.
We are also proposing several revisions to rule provisions pertaining to the calculation of biogenic emissions from tire combustion to improve the existing calculation methodology. First, for the reasons described in section II.A.2 of this preamble, the EPA is proposing to revise the calculation methods that must be used to determine the total annual CO2 emissions under 40 CFR 98.33(e)(3)(iv)(A) when determining the biogenic CO2 emissions of MSW or tires under 40 CFR 98.33(e)(3)(iv). Currently, 40 CFR 98.33(e)(3)(iv) provides procedures in certain circumstances to estimate the annual biogenic CO2 emissions in the combustion of MSW or tires, which start with requiring that the Tier 1 calculation method be used to determine the total annual CO2 emissions from MSW or tires under 40 CFR 98.33(e)(3)(iv)(A). The value determined under 40 CFR 98.33(e)(3)(iv)(A) is then multiplied by the applicable default biogenic fraction specified at 40 CFR 98.33(e)(3)(iv)(B) to determine the total biogenic CO2 emissions. At the same time, 40 CFR 98.33(a) provides four calculation methodologies, Tier 1 through 4, and an alternative methodology for certain units subject to 40 CFR part 75, for calculating CO2 emission for fuel combustion. In certain circumstances, a reporter may be required under 40 CFR 98.33(a) to calculate CO2 emissions from combustion of MSW or tires using Tiers 2 or 3 for the purposes of annual reporting, but then must also calculate the total CO2 emissions using Tier 1 under 40 CFR 98.33(e)(3)(iv)(A) for the purpose of determining and reporting the biogenic CO2 emissions from combustion of MSW or tires under 40 CFR 98.33(e)(3)(iv). This has previously resulted in some confusion for reporters where total CO2 emissions are calculated twice using different tiers, one tier for one aspect of annual reporting and another tier for biogenic calculation and reporting, and a redundancy in calculation of total CO2 emissions by reporters. This has also resulted in some confusion when comparing the calculated total CO2 emissions under 40 CFR 98.33(a) to the estimated total biogenic CO2 emissions under 40 CFR 98.33(e)(3)(iv), since they are based on different calculation methodologies. The EPA is proposing to revise 40 CFR 98.33(e)(3)(iv)(A) so that total annual CO2 emissions will be calculated using the applicable methodology in paragraphs 40 CFR 98.33(a)(1) through (a)(3) for units using Tier 1 through 3 for purposes of 40 CFR 98.33(a), and using the Tier 1 calculation methodology in paragraph 40 CFR 98.33(a)(1) for units using the Tier 4 or Part 75 for purposes of 40 CFR 98.33(a), when determining the biogenic component of MSW or tires under 40 CFR 98.33(e)(3)(iv).
The EPA is proposing two additional substantive revisions to the procedures for calculating and reporting emissions of biogenic CO2 from the combustion of tires. First, for the reasons discussed in section II.A.1 of this preamble, we are proposing to update a default factor that is used to determine biogenic CO2 emissions from the combustion of tires. Separately reporting the biogenic CO2 emissions (i.e., specifying which emissions are biogenic) from the combustion of tires is currently optional, but if a reporter elects to do so, then 40 CFR 98.33(e)(3) specifies the calculation procedure. Under 40 CFR 98.33(e)(3), if tires provide more than 10 percent of the annual heat input to a unit and the owner or operator elects to separately report the biogenic CO2 emissions from the combustion of tires, then the owner or operator must conduct testing using ASTM method D6866-16, Standard Test Methods for Determining the Biobased Content of Solid, Liquid, and Gaseous Samples Using Radiocarbon Analysis (2016) and ASTM method D7459-08, Standard Practice for Collection of Integrated Samples for the Speciation of Biomass (Biogenic) and Fossil-Derived Carbon Dioxide Emitted from Stationary Emissions Sources (2016) to determine the biogenic fraction of CO2. But if tires provide 10 percent or less of the annual heat input, then reporters have the option to separately report the biogenic CO2 emissions by multiplying the total CO2 emissions by a default factor of 0.20. The 0.20 factor is based on information from the Rubber Manufacturers Association (RMA) that was based on most current data available at the time of the publication of the GHG Reporting Rule revisions in the Federal Register on December 17, 2010 (75 FR 79092) (hereafter referred to as the 2010 Final Rule) and represented an arithmetic average of the natural rubber content (i.e., composition) of passenger and commercial tires sold and thus available for combustion. Since publication of the 2010 Final Rule, we have received a memorandum from the U.S. Tire Manufacturers Association (USTMA, formerly RMA) that based on updated data, the weighted average composition of natural rubber in tires is now 24 percent.[,] The proposed default value was calculated by weighting the average rubber content, average weight, and shipment percentage of both light duty vehicle and commercial vehicle scrap tires, which is more accurate than would result from using the arithmetic average. In addition to the comments and information provided by the USTMA, the Portland Cement Association (PCA) provided supporting information from one of its member companies, Mitsubishi Cement. Operational data (total count and weight of tires combusted) and analytical data (percent of biogenic carbon based on ASTM D6866-20) from 2020 was provided. The EPA reviewed these data and determined that they support the USTMA's recommended 0.24 default biogenic fraction for tires. We are therefore proposing to revise 40 CFR 98.33(e)(3)(iv)(B) to update the default biogenic fraction to 0.24.
Second, for the reasons described in section II.A.3 of this preamble, we are proposing that all units that combust tires must separately report biogenic CO2 emissions. The separate reporting of biogenic CO2 from tires was made optional in the 2010 Final Rule (75 FR 79100). For that rulemaking, we received no public comments on the proposal to make separate biogenic CO2 emissions reporting optional for the combustion of tires, and the proposal was finalized without modification. In the final rule preamble, however, we stated: "No comments were received on the proposal to make biogenic CO2 emissions reporting optional for the combustion of tires, and the proposal has been finalized without modification. However, tire-derived fuel has a biomass component, and perhaps it should be treated in the same manner as MSW, which is also partly biogenic. A number of units that are subject to Part 98 combust tires as the primary fuel or as a secondary fuel. Therefore, we are considering whether these units should be required to separately account for their biogenic CO2 emissions. However, before making this mandatory we intend to open it to notice and comment in a future rulemaking" (75 FR 79109). In conjunction with this change, we are proposing to remove the restriction in 40 CFR 98.33(e)(3)(iv) that the default factor may only be used to estimate the annual biogenic CO2 emissions from the combustion of tires if the combustion of tires represents "no more than 10 percent annual heat input to a unit." Following the 2010 Final Rule, reporters that chose to optionally report biogenic CO2 emissions from tire combustion were required to use quarterly flue-gas testing using ASTM methods, except that small units (i.e., units in which tires provide no more than 10 percent of the annual heat input to a unit) could alternatively use the default factor. The proposal to remove the current restriction allowing only small units to use the default factor (i.e., allowing the use of the default factor for all units that combust tires), when combined with the proposed requirement to report biogenic CO2 emissions from tire combustion, would result in a more accurate characterization of emissions from larger units since no units that combust tires alone or in conjunction with fossil fuels have reported, for RY2015 through RY2018, biogenic CO2 emissions that were calculated using the quarterly flue-gas testing results. Therefore, the proposed addition of reporting of biogenic CO2 emissions for tire combustion should require no additional monitoring or data collection and could be reported with minimal additional reporting burden. The EPA is proposing that this change would only be finalized if the proposed requirement to report biogenic CO2 emissions from tire combustion is also finalized. Additionally, we are proposing another change that would only be finalized if the proposed requirement to report biogenic CO2 emissions from tire combustion is also finalized. Specifically, 40 CFR 98.33(b)(1)(vii) currently allows units that combust MSW and/or tires to use Tier 1 if the combined heat input from both fuels is not greater than 10 percent of the heat input to the unit but also provides that, if a reporter choose the option to not report biogenic CO2 from tire combustion, the 10 percent threshold applies only to the MSW fuel. If the proposed mandatory reporting of biogenic CO2 from tire combustion is finalized, we are proposing that the additional provision in 40 CFR 98.33(b)(1)(vii) on how to apply the threshold to only MSW fuel would be deleted, since it would no longer be applicable. This may result in fewer facilities being able to use Tier 1 to calculate MSW and/or tire CO2 emissions since the tire heat input would now always be included in conjunction with the MSW heat input to compare to the 10 percent threshold.