Document ID: EPA-HQ-OAR-2013-0495-12746
Agency: epa
Document Type: Rule
Title: Pollutant-Specific Significant Contribution Finding for Greenhouse Gas Emissions from New, Modified, and Reconstructed Stationary Sources: Electric Utility Generating Units, and Process for Determining Significance of Other New Source Performance Standards Source Categories
Posted Date: 2021-01-13T05:00Z

[Federal Register Volume 86, Number 8 (Wednesday, January 13, 2021)]
[Rules and Regulations]
[Pages 2542-2558]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-00389]

=======================================================================
-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 60

[EPA-HQ-OAR-2013-0495; FRL-10019-30-OAR]
RIN 2060-AT56

Pollutant-Specific Significant Contribution Finding for 
Greenhouse Gas Emissions From New, Modified, and Reconstructed 
Stationary Sources: Electric Utility Generating Units, and Process for 
Determining Significance of Other New Source Performance Standards 
Source Categories

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: In this final action, the U.S. Environmental Protection Agency 
(EPA) is finalizing a significant contribution finding (SCF) for 
purposes of regulating source categories for greenhouse gas (GHG) 
emissions, under section 111(b) of the Clean Air Act (CAA) for electric 
generating units (EGUs), and in doing so, reaffirming that EGUs remain 
a listed source category. The EPA has reached that conclusion by 
articulating a framework under which source categories are considered 
to contribute

[[Page 2543]]

significantly to dangerous air pollution due to their GHG emissions if 
the amount of those emissions exceeds 3 percent of total U.S. GHG 
emissions. The EPA is applying the 3-percent threshold to the EGU 
source category to demonstrate that GHG emissions from the EGU source 
category would contribute significantly to dangerous air pollution. 
While EGU GHG emissions exceed this threshold by a sufficient magnitude 
to warrant an SCF without more ado, the EPA has also, for completeness, 
analyzed EGU emissions under a secondary criteria framework, which also 
demonstrates the propriety of the SCF.

DATES: The final rule is effective on March 15, 2021.

ADDRESSES: The EPA has established a docket for this action under 
Docket ID No. EPA-HQ-OAR-2013-0495. All documents in the docket are 
listed on the https://www.regulations.gov/ website. Although listed, 
some information is not publicly available, e.g., Confidential Business 
Information or other information whose disclosure is restricted by 
statute. Certain other material, such as copyrighted material, is not 
placed on the internet and will be publicly available only in hard copy 
form. With the exception of such material, publicly available docket 
materials are available electronically through https://www.regulations.gov/. 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 COVID-19. Our Docket Center staff will continue to provide 
remote customer service via email, phone, and webform. For further 
information on EPA Docket Center services and the current status, 
please visit us online at https://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: For questions about this final action, 
contact Mr. Christopher Werner, Sector Policies and Programs Division 
(D243-01), Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Research Triangle Park, North Carolina 
27711; telephone number: (919) 541-5133; fax number: (919) 541-4991; 
and email address: werner.christopher@epa.gov.

SUPPLEMENTARY INFORMATION: 
    Preamble acronyms and abbreviations. The EPA uses multiple acronyms 
and terms in this preamble. While this list may not be exhaustive, to 
ease the reading of this preamble and for reference purposes, the EPA 
defines the following terms and acronyms here:

AEO Annual Energy Outlook
BSER best system of emission reduction
[deg]C degrees Celsius
CAA Clean Air Act
CFR Code of Federal Regulations
CH4 methane
CO carbon monoxide
CO2 carbon dioxide
D.C. Cir. United States Court of Appeals for the District of 
Columbia Circuit
DOE Department of Energy
EGU electric utility generating unit
EIA U.S. Energy Information Administration
EPA Environmental Protection Agency
[deg]F degrees Fahrenheit
GHG greenhouse gas
HAP hazardous air pollutant(s)
HFC hydrofluorocarbon
km kilometers
M million
N2O nitrous oxide
NAICS North American Industry Classification System
NGCC natural gas combined cycle
NOX nitrogen oxides
NSPS new source performance standards
OMB Office of Management and Budget
PC pulverized coal
PFC perfluorocarbon
PM particulate matter
SF6 sulfur hexafluoride
SO2 sulfur dioxide
U.S. United States
U.S.C. United States Code

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

I. General Information
    A. Does this action apply to me?
    B. Where can I get a copy of this document and other related 
information?
    C. Judicial Review
II. Executive Summary
    A. What is the purpose of this regulatory action?
    B. What is the summary of the major provisions in this action?
    C. What are the costs and benefits?
III. Summary of Previous Rulemaking Actions
IV. Pollutant-Specific Significant Contribution Finding (SCF)
    A. Background
    B. What is a Significant Contribution Finding (SCF)?
    C. Primary Criteria for Determining Significance
    D. Secondary Criteria for Determining Significance
    E. Significant Contribution Finding for EGUs
V. Summary of Cost, Environmental, and Economic Impacts
    A. What are the affected facilities?
    B. What are the air quality impacts?
    C. What are the energy impacts?
    D. What are the cost impacts?
    E. What are the economic impacts?
    F. What are the benefits?
VI. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Executive Order 13771: Reducing Regulations and Controlling 
Regulatory Costs
    C. Paperwork Reduction Act (PRA)
    D. Regulatory Flexibility Act (RFA)
    E. Unfunded Mandates Reform Act (UMRA)
    F. Executive Order 13132: Federalism
    G. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    H. Executive Order 13045: Protection of Children From 
Environmental Health Risks and Safety Risks
    I. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    J. National Technology Transfer and Advancement Act (NTTAA)
    K. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
    L. Congressional Review Act (CRA)

I. General Information

A. Does this action apply to me?

    Categories and entities potentially impacted by this rule include 
sources subject to new source performance standards (NSPS) requirements 
under section 111 of the CAA. While this rule informs all NSPS source 
categories, the EPA is finalizing a SCF specific to electric generating 
units regulated under 40 CFR part 60, subpart TTTT. The North American 
Industry Classification System (NAICS) code for the industrial, federal 
government, and state/local government electric generating units is 
221112. The NAICS code for tribal government electric generating units 
is 921150.

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

    In addition to being available in the docket, an electronic copy of 
this final action is available on the internet. Following signature by 
the EPA Administrator, the EPA will post a copy of this final action at 
https://www.epa.gov/stationary-sources-air-pollution/nsps-ghg-emissions-new-modified-and-reconstructed-electric-utility. Following 
publication in the Federal Register, the EPA will post the Federal 
Register version of the final rule and key technical documents at this 
same website.

C. Judicial Review

    Under section 307(b)(1) of the Clean Air Act (CAA), judicial review 
of this final rule is available only by filing a petition for review in 
the United States Court of Appeals for the District of Columbia Circuit 
(the D.C. Circuit) by March 15, 2021. Moreover, under

[[Page 2544]]

section 307(b)(2) of the CAA, the requirements established by this 
final rule may not be challenged separately in any civil or criminal 
proceedings brought by the EPA to enforce these requirements. The 
Administrator has determined that this action is subject to section 
307(d) of the CAA (42 U.S.C. 7607(d)(1)(V)). Section 307(d)(7)(B) of 
the CAA further provides that ``[o]nly an objection to a rule or 
procedure which was raised with reasonable specificity during the 
period for public comment (including any public hearing) may be raised 
during judicial review.'' This section also provides a mechanism for 
the EPA to convene a proceeding for reconsideration ``[i]f the person 
raising an objection can demonstrate to the EPA that it was 
impracticable to raise such objection within [the period for public 
comment] or if the grounds for such objection arose after the period 
for public comment, (but within the time specified for judicial review) 
and if such objection is of central relevance to the outcome of the 
rule.'' Any person seeking to make such a demonstration to us should 
submit a Petition for Reconsideration to the Office of the 
Administrator, U.S. Environmental Protection Agency, Room 3000, WJC 
South Building, 1200 Pennsylvania Ave. NW, Washington, DC 20460, with a 
copy to both the person(s) listed in the preceding FOR FURTHER 
INFORMATION CONTACT section, and the Associate General Counsel for the 
Air and Radiation Law Office, Office of General Counsel (Mail Code 
2344A), U.S. Environmental Protection Agency, 1200 Pennsylvania Ave. 
NW, Washington, DC 20460.

II. Executive Summary

A. What is the purpose of this regulatory action?

    In Executive Order 13783 (Promoting Energy Independence and 
Economic Growth), all executive departments and agencies, including the 
EPA, were directed to ``immediately review existing regulations that 
potentially burden the development or use of domestically produced 
energy resources and appropriately suspend, revise, or rescind those 
that unduly burden the development of domestic energy resources beyond 
the degree necessary to protect the public interest or otherwise comply 
with the law.'' \1\ Moreover, the Executive Order directed the EPA to 
undertake this process of review with regard to the ``Standards of 
Performance for Greenhouse Gas Emissions from New, Modified, and 
Reconstructed Stationary Sources: Electric Utility Generating Units,'' 
80 FR 64510 (October 23, 2015) (2015 Rule).
---------------------------------------------------------------------------

    \1\ Executive Order 13783, Section 1(c), 82 FR 16093, March 31, 
2017.
---------------------------------------------------------------------------

    In a document signed the same day as Executive Order 13783 and 
published in the Federal Register at 82 FR 16330 (April 4, 2017), the 
EPA announced that, consistent with the Executive Order, it was 
initiating a review of the 2015 Rule and providing notice of a 
forthcoming proposed rulemaking consistent with the Executive Order. 
After due deliberation, the EPA issued a proposed rulemaking, ``Review 
of Standards of Performance for Greenhouse Gas Emissions From New, 
Modified, and Reconstructed Stationary Sources: Electric Utility 
Generating Units--Proposed Rule,'' 83 FR 65424 (December 20, 2018) 
(2018 Proposal). Here the EPA is finalizing a rulemaking with respect 
to whether GHG emissions from EGUs contribute significantly to 
dangerous air pollution, in reliance on a methodology articulated 
herein for determining whether GHG emissions from other NSPS source 
categories contribute significantly to dangerous air pollution. Any 
action regarding the proposal to revise the standards of performance, 
including the underlying determinations of the BSER, for new, 
reconstructed, and modified coal-fired EGUs, including certain 
technical issues, is beyond the scope of this final rule and comments 
received on the 2018 Proposal will be addressed in a separate future 
action.

B. What is the summary of the major provisions in this action?

    The EPA is finalizing a pollutant-specific SCF for GHG emissions 
from EGUs. That finding is based on an emissions threshold framework 
for determining significance, as well as secondary criteria to be 
applied in certain circumstances, for other NSPS source categories.

C. What are the costs and benefits?

    In 2015, the EPA promulgated ``Standards of Performance for 
Greenhouse Gas Emissions From New, Modified, and Reconstructed 
Stationary Sources: Electric Utility Generating Units,'' 80 FR 64510 
(October 23, 2015) (2015 Rule). When the EPA promulgated the 2015 Rule, 
it took note of both utility announcements and U.S. Energy Information 
Administration (EIA) modeling and, based on that information, concluded 
that even in the absence of this rule, (1) existing and anticipated 
economic conditions are such that few, if any, coal-fired EGUs will be 
built in the foreseeable future, and that (2) utilities and project 
developers are expected to choose new generation technologies 
(primarily natural gas combined cycle (NGCC)) that would meet the final 
standards and also renewable generating sources that are not affected 
by these final standards. See 80 FR 64515 (October 23, 2015). The EPA, 
therefore, projected that the 2015 Rule would ``result in negligible 
CO2 emission changes, quantified benefits, and costs by 2022 
as a result of the performance standards for newly constructed EGUs.'' 
Id. The Agency went on to say that it had been ``notified of few power 
sector new source performance standards (NSPS) modifications or 
reconstructions.'' Based on that additional information, the EPA said 
it ``expects that few EGUs will trigger either the modification or the 
reconstruction provisions'' of the 2015 Rule. Id. at 64516.
    The EPA has concluded that the projections described in the 2015 
Rule remain generally correct.\2\ In the period of analysis,\3\ the EPA 
expects there to be few, if any, newly constructed, reconstructed, or 
modified sources that will trigger the provisions the EPA is 
promulgating in this action. Consequently, the EPA projects that there 
will be no significant changes in carbon dioxide (CO2) 
emissions or in compliance costs as a result of this final rule.
---------------------------------------------------------------------------

    \2\ In the reference case for the most recent Annual Energy 
Outlook (AEO2020), the EIA projected no additions of new planned or 
unplanned coal capacity through 2050 (www.eia.gov/aeo2020; Table 9. 
Electricity Generating Capacity).
    \3\ Standards developed under the NSPS program must, by 
statutory requirement, be reviewed, at least, every 8 years.
---------------------------------------------------------------------------

III. Summary of Previous Rulemaking Actions

    On December 20, 2018, the EPA published a proposal to revise 
certain parts of the 2015 Rule; ``Review of Standards of Performance 
for Greenhouse Gas Emissions From New, Modified, and Reconstructed 
Stationary Sources: Electric Utility Generating Units.'' 83 FR 65424 
(2018 Proposal). The majority of that proposal was dedicated to the 
issue of the best system of emission reduction (BSER) for newly 
constructed, modified, and reconstructed coal-fired EGUs. Comments 
received on that issue are not being addressed in this rule and will be 
addressed in any future EPA action. In that proposal, the EPA solicited 
comment on whether to make a pollutant-specific significant 
contribution determination for GHG emissions from EGUs, 83 FR 65432 n. 
25, which is the subject of this action.

[[Page 2545]]

IV. Pollutant-Specific Significant Contribution Finding (SCF)

A. Background

    CAA section 111(b)(1)(A) states that ``[The Administrator] shall 
include a category of sources in such list if in his judgment it 
causes, or contributes significantly to, air pollution which may 
reasonably be anticipated to endanger public health or welfare.''
    In the 2015 Rule, the EPA promulgated standards for GHG (measured 
CO2 emissions) from fossil fuel-fired steam generating EGUs 
and combustion turbines, a pollutant that the Administrator had not 
considered when he listed the categories of those sources--fossil fuel-
fired steam generators \4\ and stationary gas turbines.\5\ See 80 FR 
64510. Similarly, in 2016, the EPA promulgated an NSPS for GHG 
(measured by methane (CH4) emissions) from oil and gas 
sources, a pollutant that the Administrator had not considered when he 
listed the category for those sources--the Crude Oil and Natural Gas 
Production source category.\6\ See 81 FR 35824 (June 3, 2016) (2016 Oil 
& Gas Rule).
---------------------------------------------------------------------------

    \4\ See ``List of Categories of Stationary Sources,'' 36 FR 5931 
(March 31, 1971) (listing source category); ``Standards of 
Performance for New Stationary Sources,'' 36 FR 24376 (December 31, 
1971) (promulgating NSPS for source category).
    \5\ See ``Standards of Performance for New Stationary Sources; 
Gas Turbines,'' 44 FR 52792 (September 10, 1979) (listing and 
promulgating NSPS for source category).
    \6\ See ``Priority List and Additions to the List of Categories 
of Stationary Sources,'' 49 FR 49222 (August 21, 1979) (listing 
source category); ``Standards of Performance for New Stationary 
Sources; Equipment Leaks of VOC From Onshore Natural Gas Processing 
Plants,'' 50 FR 26124 (June 23, 1985), and ``Standards of 
Performance for New Stationary Sources; Onshore Natural Gas 
Processing SO2 Emissions,'' 50 FR 40160 (October 1, 1985) 
(promulgating standards of performance).
---------------------------------------------------------------------------

    In each rule, the EPA interpreted CAA section 111(b) to require 
that an SCF and endangerment finding be made only with respect to the 
source category, at the time the EPA lists the category, and to 
authorize the EPA to promulgate NSPS for GHG, as long as the EPA 
provides a rational basis for doing so. However, in each rule, the EPA 
acknowledged that some stakeholders had argued that the EPA first 
needed to make a pollutant-specific SCF, that is, a finding that GHG 
from the source category contributes significantly to dangerous air 
pollution. In each rule, the EPA stated that it disagreed with those 
stakeholders, but nevertheless, in the alternative, did make a 
pollutant-specific SCF for GHG, supported by the same reasons that the 
EPA had used to determine that it had a rational basis to regulate GHG. 
See 80 FR 64529 through 64531 (2015 EGU Rule); 81 FR 35840 through 
35843 (2016 Oil & Gas Rule).
    In the 2018 Proposal, in which the EPA proposed to revise the 2015 
Rule, the EPA solicited comment on whether to adopt the interpretation 
that it was required to make an SCF for GHG from the EGU source 
category before it could promulgate an NSPS for CO2. Some 
commenters stated that the EPA must make pollutant-specific findings of 
endangerment and significant contribution in order to establish an NSPS 
for that pollutant. These commenters explained that in their view, CAA 
section 111(b)(1)(A) requires the EPA to make two specific findings: 
(1) The specific ``air pollution'' to be regulated is ``reasonably . . 
. anticipated to endanger public health or welfare;'' and (2) the 
specific source category ``causes or contributes significantly to'' 
that air pollution. Commenters asserted that CAA section 111(b)(1)(A) 
is not ambiguous in this respect, and, therefore, the Agency's 
interpretation in the 2015 Rule directly contradicts the plain language 
of that section.
    Other commenters stated that the EPA's approach in the 2015 Rule, 
that it needs to determine only that it has a rational basis to 
regulate GHGs emitted by this source category as a prerequisite to 
regulation, is sound. They said in the context of CAA section 111, the 
SCF and endangerment finding are made with respect to the source 
category, and not as to specific pollutants. These commenters supported 
the conclusion in the 2015 Rule that the EPA possesses authority to 
regulate GHG emissions from fossil fuel-fired EGUs under CAA section 
111 because there was no new evidence calling into question its 
determination that GHG air pollution may reasonably be anticipated to 
endanger public health and welfare and fossil fuel-fired EGUs have a 
high level of GHG emissions. The commenters stated that these 
considerations hew closely to the statutory factors that inform the 
decision whether to list a source category in the first place--namely, 
whether the category ``causes, or contributes significantly to, air 
pollution which may reasonably be anticipated to endanger public health 
or welfare,'' under CAA section 111(b)(1)(A). The commenters added that 
this approach, which closely parallels the listing analysis but does 
not require a formal endangerment finding or SCF, is legally sound. 
They also added that the statute is clear that a formal endangerment 
finding is required to initially list a sector to be regulated under 
CAA section 111; but it is also clear that such a finding is not 
required before regulating additional harmful pollutants from a 
previously-listed sector.\7\
---------------------------------------------------------------------------

    \7\ Some commenters on the 2018 Proposal also said that, in the 
2009 Endangerment Finding, the EPA specifically defined air 
pollution, as referred to in section 202(a) of the CAA, to be the 
mix of six well-mixed, long-lived, and directly emitted GHGs: 
CO2, CH4, N2O, HFCs, PFCs, and 
SF6. 74 FR 66497. They commented that the EPA needs to 
make, but has never made, a separate finding that CO2 
alone is reasonably anticipated to endanger the public health or 
welfare. The Agency disagrees with commenters. The air pollutant 
that the 2015 Rule regulates is GHG, and that air pollutant 
contributes to the same GHG air pollution that was addressed by the 
Endangerment Finding. The standards of performance adopted in the 
2015 Rule take the form of an emission limitation on only one 
constituent gas of this air pollutant, CO2. See 40 CFR 
60.5515(a) (``The pollutants regulated by this subpart are 
greenhouse gases. The greenhouse gas standard in this subpart is in 
the form of a limitation on emission of carbon dioxide.''). This is 
reasonable, given that CO2 is the constituent gas emitted 
in the largest volume by the source category and for which there are 
available controls that are technically feasible and cost effective. 
There is no requirement that standards of performance address each 
component of an air pollutant. CAA section 111(b)(1)(B) requires the 
EPA to establish ``standards of performance'' for listed source 
categories, and the definition of ``standard of performance'' in CAA 
section 111(a)(1) does not specify which air pollutants must be 
controlled. Moreover, as the EPA noted in the 2015 Rule, the 
information considered in the 2009 Endangerment Finding and its 
supporting record, together with additional discussion of GHG 
impacts in the 2015 Rule, makes clear that GHG air pollution may 
reasonably be anticipated to endanger public health or welfare. See 
80 FR 64517, 64530 and 31. Because the 2015 Rule followed the same 
approach as in the 2009 findings and regulated the same pollutant as 
contributing to the same air pollution (to reiterate, both the air 
pollutant and the air pollution are GHG as the group of six well-
mixed gases, including CO2), it was not necessary to 
evaluate CO2 separately. The EPA took the same position 
in the 2016 Oil & Gas Rule in response to a similar comment 
concerning CH4. See 81 FR 35843.
---------------------------------------------------------------------------

    Similarly, in a 2019 proposal to revise the 2016 Oil & Gas Rule, 
the EPA solicited comment on whether to adopt the interpretation that 
it was required to make an SCF for GHG from the Oil and Gas source 
category before it could promulgate a CH4 NSPS. Recently, 
the EPA completed the final rule to revise the 2016 Oil & Gas Rule, 
``Oil and Natural Gas Sector: Emission Standards for New, 
Reconstructed, and Modified Sources Review: Final Rule,'' 85 FR 57018 
(September 14, 2020) (2020 Oil & Gas Rule). There, the EPA determined 
that a pollutant-specific SCF is required. In addition, the EPA further 
determined that the pollutant-specific SCF in the 2016 Oil & Gas Rule 
was invalid on grounds, in part, that the EPA had not established a 
threshold or criteria by which to determine whether an amount of 
emissions contributes significantly to dangerous air pollution, and to 
distinguish from an amount of emissions that simply contributes to 
dangerous air pollution. The EPA stated

[[Page 2546]]

that section 111(b) of the CAA requires, or at least authorizes, a 
pollutant-specific SCF, and such an SCF must be based on defined 
criteria or thresholds. Id. at 57033-40.

B. What is a Significant Contribution Finding (SCF)?

1. Significant Contribution Finding and Key Comments Received
    CAA section 111 directs the EPA to regulate, through a multi-step 
process, air pollutants from categories of stationary sources. CAA 
section 111(b)(1)(A) requires the initial action, which is that the 
Administrator must ``publish . . . a list of categories of stationary 
sources. He shall include a category of sources in such list if in his 
judgment it causes, or contributes significantly to, air pollution 
which may reasonably be anticipated to endanger public health or 
welfare.'' Therefore, the first action that the EPA must take, 
specified in CAA section 111(b)(1)(A), is to list a source category for 
regulation on the basis of a determination that the category 
contributes significantly to dangerous air pollution. This provision 
makes clear that although Congress designed CAA section 111 to apply 
broadly to source categories of all types wherever located, Congress 
also imposed a constraint: The EPA is authorized to regulate only 
sources that it finds cause or contribute significantly to air 
pollution that the EPA finds to be dangerous. Because CAA section 
111(b)(1)(A) refers to air pollution, the EPA's determination that a 
source category should be listed for regulation can be based on all 
pollutants emitted by the category (i.e., collective contribution), or 
for a specific pollutant.
    After the EPA lists a source category, CAA section 111(b)(1)(B) 
then directs the EPA to propose regulations ``establishing Federal 
standards of performance'' for new sources within the source category, 
to allow public comment, and to ``promulgate . . . such standards with 
such modifications as he deems appropriate.'' CAA section 111(a)(1) 
defines the term ``standard of performance'' as ``a standard for 
emissions of air pollutants which [the Administrator is required to 
determine through a specified methodology].'' These provisions read 
together make clear that the standards of performance that CAA section 
111(b)(1)(A) directs the Administrator to promulgate must concern air 
pollutants emitted from the sources in the source category. However, 
industrial sources of the type subject to CAA section 111(b)(1)(A) 
invariably emit more than one air pollutant, and neither CAA section 
111(b)(1)(B) nor CAA section 111(a)(1), by their terms, specifies for 
which of those air pollutants the EPA must promulgate standards of 
performance.
    In the past, the EPA has interpreted CAA section 111(b)(1)(B) to 
authorize it to promulgate standards of performance for any air 
pollutant that the EPA identified in listing the source category and 
any additional air pollutant for which the EPA has identified a 
rational basis for regulation. 81 FR 35843 (2016 Oil & Gas Rule); 80 FR 
64510 (2015 Rule). Inherent in this approach is the recognition that 
CAA section 111(b)(1)(A) does not, by its terms, necessarily require 
the EPA to promulgate standards of performance for all air pollutants 
emitting from the source category. The EPA could list a source category 
on grounds that it emits numerous air pollutants that, taken together, 
significantly contribute to air pollution that may reasonably be 
anticipated to endanger public health or welfare, and proceed to 
regulate each of those pollutants, without ever finding that each (or 
any) of those air pollutants by itself causes or contributes 
significantly to--or, in terms of the text of other provisions, causes 
or contributes to--air pollution that may reasonably be anticipated to 
endanger public health or welfare.
    As described in the 2020 Oil and Gas Policy Rule, CAA section 
111(b)(1)(A) does not provide or suggest any criteria to define the 
rational basis approach, the EPA has not articulated any criteria in 
its previous applications in the EGU CO2 NSPS and the 2016 
40 CFR part 60, subpart OOOOa rules, and in instances before those 
rules in which the EPA has relied on the ``rational basis'' approach, 
the EPA has done so to justify not setting a standard for a given 
pollutant, rather than to justify setting such a standard. 85 FR 77037, 
December 1, 2020. Thus, the rational basis test allows the EPA 
virtually unfettered discretion in determining which air pollutants to 
regulate. As a result, the rational basis standard creates the 
possibility that the EPA could seek to promulgate NSPS for pollutants 
that may be emitted in relatively minor amounts.
    In contrast, CAA section 111(b)(1)(A) is clear that the EPA may 
list a source category for regulation only if the EPA determines that 
the source category ``causes or contributes significantly'' (emphasis 
added) to dangerous air pollution. As described in the 2020 Oil and Gas 
Policy Rule, in light of the stringency of this statutory requirement 
for listing a source category, it would be unreasonable to interpret 
CAA section 111(b)(1)(B) to allow the Agency to regulate air pollutants 
from the source category merely by making an administrative 
determination under the open-ended and undefined rational basis test. 
The EPA, therefore, determined it is logical to interpret CAA section 
111(b)(1)(B) to require that the Agency apply the same degree of rigor 
in determining which air pollutants to regulate as it does in 
determining which source categories to list for regulation, and, 
therefore, must make a pollutant-specific SCF. Id.
    Requiring a pollutant-specific SCF necessitates the establishment 
of a clearer framework for assessing which air pollutants merit 
regulatory attention that will require sources to bear control costs. 
The establishment of such a framework or criteria promotes regulatory 
certainty for stakeholders and consistency in the EPA's identification 
of which air pollutants to regulate and reduces the risk that air 
pollutants that do not merit regulation will nevertheless become 
subject to regulation due to an unduly vague standard.
    As previously described, CAA section 111(b)(1)(B) requires the EPA 
to establish an NSPS for a source category listed under CAA section 
111(b)(1)(A). For a source category previously listed under CAA section 
111(b)(1)(A), in order to subsequently promulgate an NSPS for a 
pollutant that the EPA did not evaluate the source category for at the 
time of listing, the EPA must make a pollutant-specific SCF for the 
reasons described above. As part of making an SCF, the EPA concluded in 
the 2020 Oil and Gas Policy Rule that, ``a standard or an established 
set of a criteria, or perhaps both, are necessary to identify what is 
significant and what is not.'' 85 FR 57039. The EPA did not finalize or 
take a position in the 2020 Oil and Gas Policy Rule on potential 
criteria, stating that it was deferring the identification of such 
criteria to a future rulemaking. Id. CAA section 111(b) itself does not 
specify what the criteria for a pollutant-specific SCF.
    The ``contributes significantly'' provision in CAA section 
111(b)(1)(A) is ambiguous as to what level of contribution is 
considered to be significant. See 84 FR 50267 and 50268, September 24, 
2019 (citing EPA v. EME Homer City Generation, L.P., 572 U.S. 489 
(2014) (holding that a similar provision in CAA section 
110(a)(2)(D)(i), often termed the ``good neighbor'' provision, is 
ambiguous)). Accordingly, the EPA has authority to interpret that 
provision. Id. at 50268. As noted above, the EPA reads CAA section 
111(b)(1)(B) in light of CAA sections 111(b)(1)(A) and 111(a)(1) to 
incorporate the ``contributes significantly'' standard in

[[Page 2547]]

connection with promulgating NSPS for particular air pollutants. The 
EPA has concluded that to allow the EPA to distinguish between a 
contribution and a significant contribution to dangerous pollution, 
some type of (reasonably explained and intelligible) standard and/or 
established set of criteria that can be consistently applied is 
necessary.
    A supporting basis for this conclusion can be found by looking at 
the EPA's interpretation of the similarly worded ``contribute 
significantly'' provisions of CAA section 189(e), concerning major 
stationary sources of particulate matter with a diameter of 10 
micrometers or less (PM10). This provision requires that the 
control requirements applicable to major stationary sources of 
PM10 also apply to major stationary sources of 
PM10 precursors ``except where the Administrator determines 
that such sources [of precursors] do not contribute significantly to 
PM10 levels which exceed the standard in the area.'' As the 
EPA noted in the 2019 Oil and Gas Policy Rule proposal, in CAA section 
189(e), Congress intended that, in order to be subject to regulation, 
the emissions must have a greater impact than a simple contribution not 
characterized as a significant contribution. However, Congress did not 
quantify how much greater. Therefore, the EPA developed criteria for 
identifying whether the impact of a particular precursor would 
``contribute significantly'' to a NAAQS exceedance. 84 FR 50268. These 
criteria included numerical thresholds. Id. The EPA concluded similarly 
that, under CAA section 111(b), a standard or an established set of a 
criteria, or perhaps both, are necessary to identify what is 
significant and what is not.
    These criteria help ensure that the EPA's decision-making is well-
reasoned and consistent. The EPA considers it particularly important to 
develop a set of criteria and/or a standard in order to determine when 
a significant contribution occurs, in order, as noted above, to 
distinguish it from a simple contribution. A contribution can be 
greater or lesser and remain a contribution, but a significant 
contribution determination necessarily involves a judgment about the 
degree of the contribution that rises to the level of significance. For 
such a judgment to be meaningful (and, of critical importance, to be 
understood by regulated parties and by the public), the Agency must 
identify the criteria it will use to determine significance.
2. Other Comments Received on the EPA's Basis for Regulating GHG 
Emissions from EGUs
    Comment: Commenters stated that the EPA must make the specific 
pollutant findings of endangerment and significant contribution that 
are required in listing a source category in order to establish a NSPS 
for that pollutant. Commenters stated they are not arguing that the EPA 
could not or should not make these findings. Rather, that the Clean Air 
Act (CAA) requires the EPA to make two specific findings: (i) The 
specific ``air pollution'' to be regulated is ``reasonably . . . 
anticipated to endanger public health or welfare''; and (ii) the 
specific source category ``causes or contributes significantly to'' 
that endangering air pollution. CAA section 111(b)(1)(A). The 
commenters said section 111(b)(1)A) is not ambiguous at all in this 
respect, and therefore the Agency's interpretation in the 2015 Rule 
directly contradicts the plain language of this section. Additionally, 
they said that in the 2009 Endangerment Finding, the EPA specifically 
defined air pollution, as referred to in section 202(a) of the CAA, to 
be the mix of six long-lived and directly emitted GHGs: CO2, 
CH4, N2O, HFCs, PFCs, and SF6 (74 FR 
66497, December 15, 2009). They commented that the EPA did not make a 
separate finding then, or now, that CO2 alone is a danger to 
the public health or welfare and the EPA has argued that because 
CO2 is the ``dominant anthropogenic GHG,'' it is not 
required to ``make an endangerment finding with respect to a particular 
pollutant.'' (Id). They argued that this view does not satisfy the 
statutory standard and said the GHG endangerment determination in 
section 111(b)(1)(A) is fundamentally different than that in section 
202(a) and other CAA sections, in part because it: (i) Is source-
category based; and (ii) requires a finding of significance.
    These commenters stated that in the 2015 Rule, the EPA made three 
arguments as to why it believed it had met its statutory obligations. 
The commenters stated that none of these arguments are correct as a 
legal matter for the following primary reasons: (1) The EPA was wrong 
in claiming that new CO2-specific findings were unnecessary, 
as the 2015 Rule was for a new category of electric utility generating 
unit (EGUs) emitting CO2--a specific pollutant for which an 
endangerment finding had not been made. EPA's prior listings of ``steam 
generators'' and ``stationary gas turbines'' covered only emissions of 
NOX, SO2, and particulate matter. Because EPA's 
findings in earlier listings addressed different pollutants, those 
listings triggered and authorized only regulation of NOX, 
SO2, and particulate matter. Cf. Nat'l Asphalt Pavement 
Ass'n v. Train, 539 F.2d 775 (D.C. Cir. 1976). EPA has asserted the 
authority to regulate under section 111 any pollutant for which EPA 
believes it has a ``rational basis'' to regulate (see 83 FR 65432; 80 
FR 64530). But this ``rational basis'' standard is not the one 
authorized by section 111; the endangerment and significant 
contribution standard governs section 111 regulation. EPA cannot 
rewrite the statute to circumvent the endangerment and significant 
contribution standard that Congress prescribed for section 111 
regulation.; (2) the EPA cannot rely on its 2009 finding regarding GHG 
emissions from automobiles which determined that ``six well-mixed 
GHGs'' in the ``aggregate'' endanger public health or welfare, as this 
``combined mix'' is different air pollutant than the single pollutant 
controlled here (CO2 alone). EPA has never found that 
CO2 alone endangers public health or welfare, much less that 
CO2 from fossil fuel-fired steam generating units (as 
opposed to motor vehicles) has that effect; and (3) the EPA's attempt 
to rely on ``information and conclusions'' contained in the 2015 Rule 
does not satisfy the CAA. Simply identifying the evidence that might 
support a finding is not the same as completing the administrative 
process of distilling and analyzing that data in the context of the 
Agency's statutory obligations and its failure to make the requisite 
findings of endangerment and significant contribution in the 2015 Rule 
violated the CAA. They said the CAA grants the EPA narrowly bounded 
authority to regulate stationary sources that emit pollutants that may 
reasonably be anticipated to endanger public health or welfare for 
those pollutants which led to the endangerment finding and to which the 
source category significantly contributes. The CAA does not grant the 
Agency unlimited authority to regulate any pollutant emitted by that 
source. Accordingly, before the EPA finalizes the 2018 Proposal, it 
must make a specific and supportable finding that CO2 
emissions from fossil fuel-fired EGUs pose a danger to public health 
and welfare. They said the EPA should reject its ill-founded ``rational 
basis test'' for imposing performance standards without endangerment 
and contribution findings. The Agency's rational basis test is not in 
the CAA. They argued that section 111 never uses the term and the case 
law on which the EPA relied for

[[Page 2548]]

this test addresses agency authority under a different statute, the 
Administrative Procedure Act (APA). The APA does not define the scope 
of the EPA's authority to undertake this rulemaking.
    Commenters added that as a textual matter, the endangerment 
requirement modifies, and relates back to, ``air pollution,'' not 
``sources'': The provision requires the EPA to determine whether a 
source causes or contributes significantly to ``air pollution which may 
reasonably be anticipated to endanger public health or welfare.'' 42 
United States Code (U.S.C.) section 7411(b)(1)(A). Only after the EPA 
determines that a pollutant poses a threat to ``public health or 
welfare'' must it inquire whether the particular category of sources 
``contributes significantly'' to that pollution. Id. The idea that an 
endangerment finding is ``one and done'' on a source level also cannot 
be squared with the surrounding statutory requirements. Section 
111(b)(1)(B) provides that the EPA may issue performance standards 
after a source category is listed pursuant to section 111(b)(1)(A). Id. 
section 7411(b)(1)(B). Yet by definition, a ``standard of performance'' 
is tied to specific pollutants for which an endangerment finding has 
been made. Id. section 7411 (a)(1) (defining a ``standard of 
performance'' as ``a standard for emissions of air pollutants). 
Commenters said that as such, the approach in the 2015 Rule would give 
the EPA unfettered authority to regulate any air pollutant emitted by a 
source regardless of whether it endangers health or welfare and the 
2015 Rule's approach of mixing and matching elements of endangerment 
findings would allow the EPA to impose stringent regulations on sources 
that do not ``contribute significantly'' to emissions of a pollutant. 
In summary, the commenters argued that if the EPA ``retain[s]'' the 
``statutory interpretation'' of section 111 as set out in the 2015 
Rule, 83 FR 65432 n. 25, it will once again be setting standards beyond 
the scope of its authority and it may be that the EPA can make the 
findings section 111(b)(1)(A) requires for CO2 emissions 
from fossil-fuel-fired electricity generating units, but unless and 
until the EPA makes those determinations under the proper legal 
standard, the Proposed Rule will rest on a flawed foundation.
    Commenters stated that the previous endangerment findings the EPA 
listed in the 2015 Rule did not relate to ``fossil fuel-fired 
electricity generating units.'' (80 FR 64527 nn.86 & 87). Rather, one 
related to ``steam generators,'' (36 FR 5931, March 31, 1971,--cited at 
80 FR 64527 n.86), and the other to ``stationary gas turbines,'' (42 FR 
53657. October 3, 1977,--cited at 80 FR 64527 n.87). The commenters 
stated that this failing should prevent the EPA's ability to move 
forward with proposed regulation because the Agency has not issued the 
required endangerment finding for the specific source category, it 
becomes irrelevant whether it may rely on that (nonexistent) finding to 
justify setting standards of performance for different emissions from 
sources in the category.
    Commenters stated that in the 2016 subpart OOOOa rulemaking, the 
EPA established NSPS for CH4 without making an endangerment 
finding for CH4 emissions from oil and gas sources. 
Commenters and other industry groups filed comments pointing out the 
EPA's omission in failing to make a section 111(b) endangerment finding 
for the new pollutant subject to regulation under NSPS. By imposing 
NSPS requirements for a new pollutant without first establishing that 
that pollutant ``may reasonably be anticipated to endanger public 
health or welfare'' (i.e., making an endangerment finding), commenters 
urged the EPA to reject and withdraw the interpretation that the EPA 
may skip the endangerment finding step in this context. The commenters 
further urged the EPA to clarify that a statutory prerequisite for 
regulation of a new pollutant under the NSPS program is an endangerment 
finding for that particular pollutant. Finally, and as a separate 
matter, the commenters urged the EPA to revisit the legal underpinnings 
for the subpart OOOOa standards as the commenters asserted the EPA did 
not follow the statutory prerequisites for the adoption of such 
standards. According to the commenters, those standards are illegal as 
being outside of the agency's authority, and as such should now be 
withdrawn.
    Other commenters stated that the EPA's previous approach in the 
2015 Rule to determining that it has a rational basis to regulate GHGs 
emitted by this source category is sound. The Agency has correctly not 
reopened this approach, nor has it proposed any alternatives to it. 
They said in the context of section 111, the endangerment finding is 
made with respect to the source category, and not as to specific 
pollutants (80 FR 64530). It would be unlawful for the Agency to 
finalize any alternative approach. In 2015, the EPA concluded that it 
possesses authority to regulate GHG emissions from fossil fuel-fired 
EGUs under section 111 for two reasons: (1) There was no new evidence 
calling into question its determination that ``GHG air pollution may 
reasonably be anticipated to endanger public health and welfare''; and 
(2) fossil fuel-fired EGUs have a ``high level of GHG emissions.'' 
These considerations hew closely to the statutory factors that inform 
the decision whether to list a source category in the first place--
namely, whether the category ``causes, or contributes significantly to, 
air pollution which may reasonably be anticipated to endanger public 
health or welfare.'' In fact, in 2015 the Agency confirmed that, even 
if it were required to issue endangerment and significant contribution 
findings under this provision in order to regulate GHGs emitted by 
EGUs, the same information that underpinned its rational basis 
conclusion would support such findings (80 FR 64530). This approach, 
which closely parallels the listing analysis but does not require 
formal endangerment or cause-or-contribute findings, is legally sound. 
The statute is clear that a formal endangerment finding is required to 
initially list a sector to be regulated under section 111--and is also 
clear that such a finding is not required before regulating additional 
harmful pollutants from a previously-listed sector. Because Congress 
did not provide specific criteria for regulating additional pollutants 
from a source category that is already listed under section 111, it is 
reasonable to look to the statutory factors that trigger regulation 
initially when deciding whether to require reductions of other 
pollutants. They said the statutory factors for listing a source 
category--the endangerment and cause-or-contribute findings--provide a 
floor for when EPA must regulate an additional pollutant from a listed 
source category under the rational basis inquiry. It would be 
irrational to fail to regulate an additional pollutant simply because a 
source category was already listed, if the same evidence regarding that 
pollutant would have triggered a formal listing of that source category 
had the source category not previously been listed. Thus, it would be 
arbitrary for the agency to decline to regulate a pollutant on the 
basis of considerations wholly unrelated to the harms that pollutant 
poses or the quantities in which it is emitted from a particular source 
category.
    Other commenters also stated that any effort to reverse the EPA's 
decision to regulate CO2 from power plants would require, 
among other things, that the EPA fully contend with each step of the 
statutory and legal analysis of section 111 it undertook in the 2015 
Rule, and

[[Page 2549]]

explain why each of them has become invalid. They said promulgating a 
final rule contrary to the 2015 Rule without the requisite record-
based, factual analysis and reasoned explanation would yield ``an 
unexplained inconsistency in agency policy'' that is arbitrary, 
capricious, and unlawful. Commenters stated that that while the most 
comprehensive approach to sensible GHG regulation remains through 
congressional action, and while the CAA is far from the perfect tool 
for regulating GHGs, it is preferable to protracted legal battles and 
to the potential patchwork of judicial and regulatory outcomes. As a 
result, the Agency should retain the existing endangerment finding. 
They said that if the EPA fails to regulate GHG emissions from new 
coal-fired EGUs it would be wholly unreasonable and contrary to the 
endangerment finding.
    Response: The EPA addressed the substance of these comments in a 
lengthy discussion in ``Oil and Natural Gas Sector: Emission Standards 
for New, Reconstructed, and Modified Sources Review: Final Rule,'' 85 
FR 57018, 57033-40, 57052-58 (September 14, 2020). That discussion is 
incorporated by reference here. That discussion further elaborates the 
rationale for EPA's determination that a pollutant-specific significant 
contribution determination is appropriate, and EPA's related 
determinations. That discussion also responds in full to the comments 
on the present rule.
    It should be noted that in the 2015 Rule, EPA combined the steam 
generating source category and combustion turbine source category into 
a single source category for purposes of GHG emission regulation, 80 FR 
64510, 64521-32 (October 23, 2015), and determined, in the alternative, 
that GHG emissions from the combined source category contribute 
significantly to dangerous air pollution. Id. at 64531. In today's 
rulemaking, the EPA is not revising the source category determination 
in the 2015 Rule and, by the same token, the significant contribution 
finding that EPA is making in the present rulemaking for GHG emissions 
concerns emissions from the same, combined source category.
    Comment: Commenters stated that if the Endangerment Finding is 
overturned, the electric power sector could be broadly exposed to tort 
and nuisance suits brought by citizens and states--as was the case 
prior to the EPA regulation of GHGs (e.g., American Electric Power Co. 
v. Connecticut, 564 U.S. 610 (2011)). Accordingly, these efforts would 
create more uncertainty about the future of GHG regulations applicable 
to new EGUs--uncertainty that likely would not be resolved for years 
and could undermine any potential for generation owners and operators 
to consider new coal-based generation as a viable option. They said as 
a result, the Agency should retain the existing endangerment finding.
    Response: The Agency has not proposed to overturn the existing 
Endangerment Finding and is not overturning it in this final rule.
    Comment: Commenters stated that to the extent that emissions of 
CO2 from new, modified, or reconstructed electric utility 
generating units are to be subjected by the EPA to regulation under the 
CAA, the proper path would be to regulate such emissions as part of a 
broader effort to regulate CO2 emissions from ``numerous or 
diverse'' sources under sections 108-110 of the CAA. Alternatively, if 
the EPA is adamant in engaging in regulating such emissions under 
section 111(b), at the very least the EPA must complete a specific 
endangerment finding for CO2 emissions from such facilities 
under the applicable criteria set forth in section 111(b), which the 
EPA has failed to do to date. Either way, commenters stated that the 
proposed rule amendment is beyond the legal authority of the CAA.
    Response: EPA is making a pollutant-specific significant 
contribution finding in this action.
    Comment: Commenters quoted the NSPS proposal as stating that ``the 
Agency will consider comments on the correctness of the EPA's 
interpretations and determinations, and whether there are alternative 
interpretations that may be permissible, either as a general matter or 
specifically as applied to GHG emissions'' (83 FR 65242, 65432 n.25). 
Commenters then stated that they filed a petition in 2017 contending 
that the EPA should commence a new rulemaking on the subject of the 
Agency's 2009 endangerment finding. They provided the following 
arguments of the 2017 petition: (1) There had been no statistically 
significant atmospheric warming despite a continued increase in 
atmospheric CO2 levels; (2) changes in global temperatures 
in recent decades were far from unusual; (3) new balloon and satellite 
data showed that the atmosphere was far less sensitive to 
CO2 forcing than the climate models had predicted; and (4) 
there was mounting evidence that the EPA's GHG rules would have no 
discernible climate impact. For these reasons, they said there was a 
need to reexamine both the three lines of evidence for the EPA's 
endangerment finding as well as its underlying rationale. Regarding the 
proposal, the commenters stated that in addition to their still pending 
petition, they are providing new evidence for why the Agency should 
proceed with this petition and with similar petitions pending before 
it. They submitted references (titles, weblinks, and synopses) to nine 
research papers published since filing their initial petition which 
they argue add additional support. They stated that given the points 
and data outlined in this newer research, in addition to those set 
forth in their 2017 petition, the EPA should commence a new proceeding 
to reexamine its 2009 endangerment finding.
    Response: The Agency is retaining the existing endangerment 
finding. The submitted material is out of scope for this rulemaking. 
With regards to the claim that EPA was soliciting comments on this 
subject, the footnote quoted by the commenters goes on to specifically 
outline examples of the kind of comments referred to: This further 
elaboration made clear that EPA was not soliciting comments on the 
science of climate change but rather regarding interpretation of 
statutory language and legal opinion as to whether the Agency would 
need to make an endangerment finding for previously listed source 
categories (``For example, the Agency will consider comments on the 
issue of whether it is correct to interpret the ``endangerment 
finding'' as a finding that is only made once for each source category 
at the time that the EPA lists the source category or whether the EPA 
must make a new endangerment finding each time the Agency regulates an 
additional pollutant by an already-listed source category. Further, the 
EPA will consider comments on the issue of whether GHG emissions are 
different in salient respects from traditional emissions such that it 
would be appropriate to conduct a new ``endangerment finding'' with 
respect to GHG emissions from a previously listed source category. In 
addition, the EPA solicits comment on whether the Agency does have a 
rational basis for regulating CO2 emissions from new coal-
fired electric utility steam generating units and whether it would have 
a rational basis for declining to do so at this time'' 83 FR 65242, 
65432 n.25).
    Comment: Commenters also said that the Agency suggestion in 
footnote 25 of the Proposal is unreasonable in that the Agency seems to 
presume that it might not be appropriate to regulate GHGs from new 
coal-fired power plants because the Agency projects that few such 
plants will be built in coming years. They said this approach asks the

[[Page 2550]]

wrong question. The question should be whether there is a rational 
basis to regulate GHGs from power plants--not just new coal-fired 
plants. This is because, once new sources are regulated under section 
111(b), the obligation to regulate existing sources under section 
111(d) is triggered. If new sources in a source category could not be 
regulated under section 111(b), no sources in the category could be 
regulated. Commenters further stated that the EPA cannot reverse its 
position merely by asking for comments on whether it should adopt a new 
position diametrically opposed to both current law and the position it 
maintains in the Proposed Rule.
    Commenters stated that using footnote 25 as a means of requesting 
public comment is misleading and violates administrative procedures. 
They said that it appears that the EPA is seeking rationale or 
justification to under the legal basis for this rule while claiming 
that is retaining its legal basis. The EPA cannot have it both ways: 
either EPA is using its legal basis, or it is looking for alternatives. 
If it is looking for alternatives, then EPA has not met its 
responsibilities under the Administrative Procedures Act for fair 
notice of the nature and scope of this rulemaking.
    Commenters stated that in the endangerment finding footnote of the 
2018 Proposal (83 FR 65432 n 25), the EPA suggests that it may consider 
whether it would have a rational basis to decline to regulate given 
that ``no more than a few new coal-fired EGUs can be expected to be 
built.'' The commenters said this suggestion is not legally or 
factually sound and does not provides a valid reason not to regulate 
GHGs from fossil fuel-fired EGUs under section 111. They said the 
statute is unambiguous: The EPA must consider pollution from both new 
and existing sources when deciding whether to regulate a pollutant 
within a source category. To the extent that the statute contains any 
ambiguity, a decision not to regulate based solely on projected levels 
of emissions from new sources would be disallowed as an impermissible 
construction. They argued that section 111(b) unambiguously expresses 
Congress's concern with pollution emitted from a source category as a 
whole, not just new sources and 111(b) directs the Administrator to 
base decisions about whether to list a source category on an analysis 
of the entire category, including existing sources. Section 
111(b)(1)(A) does not distinguish between ``new'' and ``existing'' 
sources but rather conveys Congress's directive to address pollution 
across the source category.
    The commenters also stated that Footnote 25 of the proposal raises 
the prospect that, on the question of regulating a pollutant from a 
listed source category, Congress inexplicably intended for the EPA to 
consider pollution from new sources only, irrespective of the harm 
caused by pollution from existing sources--and even though Congress 
directed the EPA to consider the air pollution from the sector as a 
whole, that plain language should be ignored. They said the Agency 
presents no support for this theory, which is contrary to both the 
clear terms and the evident objective of the statute. The commenters 
argued that Footnote 25's suggested interpretation disregards statutory 
language in other ways as well. For example, section 111(b)(1) provides 
that the Administrator ``shall include a category of sources in such 
list if in his judgment it causes, or contributes significantly to, air 
pollution which may reasonably be anticipated to endanger public health 
or welfare.'' (42 U.S.C. 7411(b)(1)(A)). Yet as of the date of when the 
EPA determines to list a source category, there are no ``new'' sources 
in existence. Section 111(a)(2) provides: ``The term ``new source'' 
means any stationary source, the construction or modification of which 
is commenced after the publication of regulations (or, if earlier, 
proposed regulations) prescribing a standard of performance under this 
section which will be applicable to such source.'' (Id. section 
7411(a)(2)). They said under section 111, listing precedes promulgation 
of standards. So, when the EPA decides whether to list a category, by 
definition it has not yet proposed section 111 standards for that 
category and because it has not proposed such standards, no sources 
qualify as ``new'' sources under section 111(a)(2). Basing a decision 
not to list (and therefore not to regulate) a source category solely on 
the absence of emissions from as yet nonexistent ``new'' sources--while 
ignoring sources that already exist and are emitting pollutants that 
threaten harm to public health and welfare--is not a tenable reading of 
the statutory language.
    Response: In this rule, EPA takes the position that GHG emissions 
from new and existing EGUs contribute significantly to dangerous air 
pollution. While EPA proposed to retain the position that it stated in 
the 2015 Rule that a pollutant-specific significant contribution 
finding is not required, it solicited comment on whether such a finding 
is required, and that comment solicitation provided adequate notice.
    Comment: Commenters stated that though the EPA notes that it is not 
proposing to revisit its 2009 endangerment finding for greenhouse 
gases, the proposed NSPS revisions request comment on whether recent 
and projected power sector trends present a rational basis to decline 
to regulate CO2 emissions from the power sector. The 
suggested comment area, presented in footnote 25, cites power sector 
trend projections from the Energy Information Administration's (EIA's) 
2018 Annual Energy Outlook and findings from the EPA's proposed 
Affordable Clean Energy (ACE) rule as potential support for this 
position. Commenters also stated that the EIA's 2018 Annual Energy 
Outlook does not indicate that power sector CO2 emissions 
will decline significantly in the future. Instead, the estimates 
referenced by the EPA in the proposal project that CO2 
emissions from the power sector will remain the single largest sector-
based source of CO2 emissions over the long term, totaling 
1.72 billion tons in 2020, 1.71 billion tons in 2030, and 1.78 billion 
tons in 2050. Commenters said though the EPA found that the 
transportation sector overtook the power sector as the largest sector-
based source of GHG emissions in 2017, the 2018 Annual Energy Outlook 
projects that power sector emissions will regain the top ranking in 
2026 and maintain a lead over the transportation sector by growing 
modestly through 2050. Commenters stated while newer EIA projections 
that were unavailable at the time of the EPA's proposal indicate 
slightly lower power sector CO2 emissions, EIA still 
projects significant and sustained power sector GHG emissions through 
2050, not a steady decline. Commenters said a report from the Rhodium 
Group based on preliminary EIA data for 2018 and released a few weeks 
after the EPA's proposal estimates that power sector-related GHG 
emissions increased 3.4 percent in 2018, breaking a three-year trend of 
decreases. Commenters added still more recent EPA data reveals the same 
pattern. Commenters stated preliminary 2018 emissions data compiled by 
EPA's Clean Air Markets Division (CAMD), also released after the 
proposed NSPS revisions were published in the Federal Register, show 
power sector CO2 emissions rising from 1.92 billion tons in 
2017 to 1.93 billion tons in 2018. Commenters said prior to the 2018 
release, EPA's CAMD data had shown flat or declining CO2 
emissions for every year since 2013.
    Commenters stated it would be unlawful and arbitrary for the EPA to 
use declining power sector emissions as

[[Page 2551]]

reason for not regulating. They argued that even if power sector 
emissions are declining--which is not at all clear--they are far higher 
than levels necessary to keep CO2 concentrations from rising 
further, let alone to achieve the necessary net-zero balance. 
CO2 pollution accumulates in the atmosphere, where it 
lingers for centuries, such that a year-to-year decline in emissions 
does not prevent atmospheric concentrations from continuing to rise, 
exacerbating the impacts of climate change. ``[T]he urgency of reducing 
emissions now,'' (80 FR 64520) which the EPA acknowledged in the 2015 
Rule, has only increased in recent years. Commenters said reliance on 
recent emission trends is even more unfounded because U.S. climate 
pollution significantly increased in 2018, including a 1.9 percent 
increase in power sector carbon pollution. Even before the 2018 data 
were available, U.S. Energy Information Administration (EIA) had 
recognized long-term market and economic uncertainty, which could 
potentially drive some shift back to coal generation. EIA projections 
now show that the general trend toward declining carbon pollution from 
the power sector is likely to flatten out in the early 2020s. 
Commenters stated standards that even if pollution levels were 
declining more steadily, that would not authorize the EPA to ignore its 
obligation to protect the public from what will continue to be a major 
threat to public health and the environment. The CAA is not concerned 
merely with whether pollution levels are currently below their historic 
peak. To the contrary, the Agency must ensure that pollution is 
controlled to the degree the statute requires--i.e., in accordance with 
a standard of performance that reflects the best system of emission 
reduction (BSER) (42 U.S.C. 7411(a)(1)).
    The commenters also said that there may be other reasons why a 
developer would be willing to pay a premium to build a new coal-fired 
plant that the models do not consider (80 FR 64559-64562). Thus, it is 
unreasonable not to establish standards of performance on the 
assumption that coal-fired power plants will never again be built (or 
modified). They said that the Agency does not even consider the fact 
that the source category includes not only new sources but also 
existing sources that undergo certain ``modifications,'' and that such 
modified sources have significant CO2 emissions.
    Commenters said that by asking whether the Agency has a rational 
basis for regulating CO2 emissions from new coal-fired EGUs 
``in light of'' the projections cited in footnote 25, the EPA is 
setting itself up to conduct continual market evaluations for all the 
EPA regulations for which regulation is premised on a similar type of 
prerequisite determination. An interpretation of section 111 that leads 
to that result is unreasonable and impractical. They said that there is 
no indication in the CAA that Congress intended the Agency to undertake 
a continual market assessment of this nature.
    Commenters stated that the endangerment finding footnote of the 
2018 Proposal (83 FR 65432 footnote 25) contains a fatal factual 
deficiency in that it suggests that the rational basis finding might be 
reversed because ``no more than a few new coal-fired EGUs can be 
expected to be built, which raises questions about whether new coal-
fired EGUs contribute significantly to atmospheric CO2 
levels.'' The commenters said that not only does this suggestion 
disregard the EPA's 2015 acknowledgment that ``the CO2 
emissions from even a single new coal-fired power plant may amount to 
millions of tons each year,'' but it entirely ignores natural gas-fired 
power plants, which are also included in the source category. In making 
the 2015 determination, the EPA specifically observed that ``the 
CO2 emissions from even a single natural gas combined cycle 
(NGCC) unit may amount to one million or more tons per year.'' They 
said natural gas-fired power plants continue to be built at a steady 
clip as evidenced by the first ten months of 2018 in which 14.9 
gigawatts (GW) of natural gas-fired EGU capacity was added to the grid. 
New gas plants must be accounted for and by failing to do so, the 
Agency would forfeit any ``rational connection between the facts found 
and the choice made,'' and would fail to provide ``a reasoned 
explanation . . . for disregarding facts and circumstances that 
underlay . . . the prior policy.'' Each of those flaws would render the 
decision arbitrary and capricious. Commenters said that even if the EPA 
legally could regulate CO2 emissions from new natural gas 
plants without regulating CO2 emissions from new coal-fired 
power plants, the EPA should not do so because such partial regulation 
would provide an inadvertent subsidy to new coal-fired plants.
    Response: In this rule, the EPA is determining that GHG emissions 
from EGUs contribute significantly to dangerous air pollution and is 
promulgating revised standards of performance for EGU GHG emissions. To 
the extent it is useful or necessary in this rulemaking for the EPA to 
further address whether long-term emission trends, or related 
considerations, are relevant for a significant contribution 
determination, the EPA does so elsewhere in this document.

C. Primary Criteria for Determining Significance

    In this section, the EPA describes criteria for determining when 
GHG emissions from a source category contribute significantly to 
dangerous air pollution in response to comments submitted on this rule. 
The EPA indicated in the 2020 Oil and Gas Policy Rule that it would 
finalize these criteria in a separate rulemaking. 85 FR 57039.
1. GHG Emissions
    The criteria discussed herein only apply to GHG in the context of 
the EPA's SCF under CAA section 111(b)(1)(B). This action does not 
discuss criteria for pollutants other than GHGs. Under this framework, 
the EPA is determining that the quantity of GHG emissions from a source 
category is the primary criterion in determining significance for 
purposes of regulation of GHGs from a source category under CAA section 
111(b). Gross GHG emissions are important for this set of pollutants 
because GHGs are global long-lived pollutants and do not have the 
local, near-term ramifications found with other pollutants (e.g., 
criteria pollutants). Unlike other pollutants where both the location 
and quantity of pollution emissions are factors in determining the 
impact of the emissions, GHGs' impact (i.e., climate change) is based 
on a cumulative global loading and the location of emissions is not 
nearly as important a factor as it is for assessing local, near-term 
impacts associated with criteria pollutants. It is for this reason 
that, when the EPA is assessing GHGs impact in contributing 
significantly to air pollution which may reasonably be anticipated to 
endanger public health and welfare, the quantity of emissions should be 
the primary criterion that the EPA should evaluate.
    The GHG emissions are the best, but not necessarily only, indicator 
of significance because the quantity of emissions emitted from a source 
category correlates directly with impacts. Calculations using the Model 
for the Assessment of Greenhouse Gas Induced Climate Change (MAGICC 
model) to investigate the impact of including or eliminating a single 
sector's emissions from 2020 through 2100 have shown that the magnitude 
of emissions from that single sector is very close to being linearly 
related to the projected temperature change in 2100 resulting from 
eliminating that sector's emissions. This is consistent with the

[[Page 2552]]

results of a number of peer reviewed publications in the past decade: 
e.g., Matthews et al. found that the temperature change is roughly 
proportional to the total quantity of CO2 emissions over a 
wide range of potential scenarios.\8\
---------------------------------------------------------------------------

    \8\ H. Damon Matthews, Nathan P. Gillett, Peter A. Stott & 
Kirsten Zickfeld, The Proportionality of Global Warming to 
Cumulative Carbon Emissions. Nature 459, 829-832 (2009), available 
at https://www.nature.com/articles/nature08047.
---------------------------------------------------------------------------

    A threshold of GHG emissions from the source category compared to 
the rest of the U.S. GHG emissions (i.e., the percent of total U.S. GHG 
emissions) can be used to demonstrate significance. Emissions can be 
large enough from a source category that the evaluation of GHG 
emissions in isolation is sufficient for making a finding of 
significance for the source category. Conversely, the EPA believes that 
some source categories are sufficiently small in GHG emissions that a 
finding of insignificance can be made by only evaluating the GHG 
emissions from the source category. For many source categories, the 
evaluation of GHG emissions alone will be sufficient for determining 
whether there is significant contribution.
    It should be noted that under section 111(b)(1)(A), the EPA is 
required to make a significance finding on a category-by-category 
basis. That provision requires the Administrator to list ``a category 
of sources'' for regulation if he determines that ``it causes or 
contributes significantly to'' dangerous air pollution. Section 
111(b)(1)(A) (emphasis. added). As a result, the text of 111(b)(1)(A) 
compels or is at least best read to require the EPA to make the 
significance determination for a particular source category on the 
basis of the emissions (or other relevant attributes) of that 
particular source category. In contrast, the EPA may not combine source 
categories that individually would not meet the significance criteria 
and determine that, when combined, the source categories do meet the 
significance criteria.\9\
---------------------------------------------------------------------------

    \9\ By the same token, as the EPA explained in the 2020 Oil & 
Gas Rule, there are limits to the EPA's ability to expand a source 
category to include other sources. As the EPA stated in that rule, 
``the authority to revise the scope of a source category must be 
exercised within reasonable boundaries and cannot be employed in a 
way that results in an unreasonable expansion of an existing source 
category. . . . [T]he EPA is not authorized to expand the scope of a 
listed source category to cover a new set of sources that are not 
sufficiently related to the sources in the pre-existing category. . 
. '' 85 FR 57027.
---------------------------------------------------------------------------

2. Using a Threshold in Significance Determination
    Under this framework, the EPA is determining a threshold for the 
evaluation of significance of GHG emissions from source categories. The 
use of a clear threshold provides certainty regarding the EPA's process 
and allows the regulated entities to have insight into how the EPA will 
make determinations on significance for their respective source 
category. The threshold introduced in this rulemaking is a reflection 
of the EPA's best understanding of the landscape of the U.S. GHG 
emissions from stationary sources. The EPA is introducing a methodology 
to evaluate significance with respect to the U.S. GHG emissions that 
can be applied for any source category, and that application of the 
methodology is only being directly applied to the EGU source category 
in this action as further introduction of this approach. It is 
important to note that a significance determination for the U.S. GHG 
emissions will be needed before the EPA may regulate any other source 
category under CAA section 111(b) for GHG emissions.
    As Table 1, below, makes clear, there are at least two natural 
breakpoints between groups of emitting source categories. The first 
natural breakpoint is between EGUs and all other source categories. 
EGUs stand out as by far the largest stationary source of the U.S. GHG 
emissions, emitting over 25 percent of all the U.S. GHG emissions. 
Based on available data, the next largest source category, Oil and 
Natural Gas, emits just under 3 percent of U.S. GHG emissions. Two 
other source categories, Boilers and Petroleum Refineries, also fall 
between 2.5 percent and 3.0 percent of U.S. emissions. Between 1.5 
percent and 2.5 percent of U.S. GHG emissions there is another natural 
breakpoint and all of the remaining source categories fall below 1.5 
percent of the U.S. GHG emissions. Note that source category emissions 
in Table 1 are an estimate of what the Agency currently understands 
about the emissions from CAA section 111 source categories. If the EPA 
were to do a rulemaking and a significance determination for a specific 
source category, the EPA would do a thorough analysis of the available 
and attributable GHG emissions data to ensure appropriate 
determinations and assessments.

              Table 1--Examination of GHG Emissions From Large Stationary Sources of GHG Emissions
----------------------------------------------------------------------------------------------------------------
                                                                                                Percent of U.S.
                                                                                                 GHG emissions
                                        Emissions in that range   Source categories affected    from stationary
    % of total U.S. GHG emissions            (MMT CO2e) *           at different thresholds     sources covered
                                                                                                    at given
                                                                                                 threshold  (%)
----------------------------------------------------------------------------------------------------------------
Above 25%............................  >1670 MMT...............  EGUs (1778 MMT/27% of total                  43
                                                                  US GHG Emissions, 3.6% of
                                                                  Global emissions).
3% to 25%............................  200 MMT-1670 MMT........  No categories identified....                 43
2.5% to 3.0%.........................  167-200 MMT.............  Oil/Gas Production and                       56
                                                                  Processing; [supcaret]
                                                                  Refineries; Boilers.
2.0% to 2.5%.........................  134-167 MMT.............  No categories identified....                 56
1.5% to 2.0%.........................  100-134 MMT.............  No categories identified....                 56
1.0% to 1.5%.........................  67-100 MMT..............  Landfills; I Iron and Steel.                 60
----------------------------------------------------------------------------------------------------------------
* MMT CO2e = Million metric tons of carbon dioxide equivalent
[supcaret] Note that the oil and gas production and processing GHG emissions are very close to the 3% value and
  thus there is a possibility that this source category may be above the threshold in the near term.
I Note that the Landfills source category has already been regulated under CAA section 111 and the level of the
  emissions in Table 1. reflects reductions in GHG emissions as a result of that regulation as a co-benefit.

    The EPA is introducing a threshold of 3 percent of U.S. GHG 
emissions to evaluate a source category's emissions to determine 
significance for purposes of CAA section 111(b). The EPA is also 
determining that source categories that

[[Page 2553]]

are less than this value (i.e., 3 percent or less) are necessarily 
insignificant without consideration of any other factors. The reasoning 
for choosing this threshold is presented later in this document.
    The EPA acknowledges that, when interpreting other CAA provisions, 
the EPA has used different thresholds to define ``significant 
contribution,'' but it is appropriate to select a threshold based on 
the nature of the problem being addressed. For example, to address the 
problem of interstate transport under CAA section 111(a)(2)(D)(i)(I)--
which concerns criteria pollutants, i.e., pollutants that affect the 
NAAQS--the EPA selected a threshold of 1 percent based on analysis of 
air quality modeling specific to the criteria pollutant at issue. 76 FR 
48208, 48236 (August 8, 2011) (Cross-State Air Pollution Rule (CSAPR)). 
For criteria pollutants, both the location and quantity of emissions 
are factors in determining their impact. In contrast, the impact of 
GHGs (e.g., climate change) is based on a cumulative global loading, 
and the location of emissions is not nearly as important a factor as it 
is for assessing local impacts associated with criteria pollutants. 
Because GHGs do not have the local near-term impacts that criteria 
pollutants tend to have, a larger value is appropriate to use in 
determining significance as it still addresses the health and welfare 
impacts of GHG emissions without specifically evaluating local near-
term impacts, which is analytically unreasonable to do given the global 
nature of GHGs. While the 3 percent threshold will be applied against 
domestic emissions, source categories exceeding that threshold 
represent a much smaller fraction of global GHG emissions.\10\
---------------------------------------------------------------------------

    \10\ The EPA recognizes that in the 2016 Oil & Gas Rule, it 
determined that GHG emissions from the oil and natural gas source 
category contribute significantly to dangerous air pollution, in 
part, on the grounds that those emissions exceeded the total amount 
of emissions from various foreign countries. 81 FR 35824, 35840 
(June 3, 2016). The EPA believes that its current approach of 
identifying a threshold for significance based on a percentage of 
U.S. emissions is better reasoned than the 2016 Oil & Gas Rule's 
approach of drawing comparisons to the absolute emissions of other 
countries.
---------------------------------------------------------------------------

    By determining a threshold, the EPA is setting a clear indication 
of how source categories will be evaluated for significance based on 
GHG emissions. For those source categories that are below the 3 percent 
threshold, the EPA would make a determination (through future 
rulemaking) of insignificance. This means that if a source category 
collectively emits 3 percent or less of the total U.S. GHG emissions, 
it will be considered to be insignificant. For those source categories 
that are above the threshold, a more detailed evaluation of other 
criteria can be used to make a determination of significance. This is 
described in section IV.D below. It is important for the EPA to make 
this clear indication as it allows source categories and the general 
public a level of transparency as to how the EPA will be evaluating 
source categories for significance. The threshold in this action will 
provide a degree of certainty regarding whether a source category will 
later be found significant or insignificant based on the threshold.\11\
---------------------------------------------------------------------------

    \11\ The EPA does not currently have a comprehensive inventory 
of the U.S. GHG emissions for all of the NSPS source categories. For 
the EPA to make determinations of significance for a source 
category, a more comprehensive emissions profile of a source 
category should be used. The EPA will make determinations of 
significance for other source categories in the future.
---------------------------------------------------------------------------

    After evaluating the two natural break points in GHG emissions, the 
EPA determined that 3 percent of the U.S. GHG emissions was the best 
threshold for determining significance. As noted above, there is 
currently only one source category above this threshold, EGUs, and the 
evaluation of significance for the EGU source category has been a topic 
explored and discussed by the Agency in great detail over the course of 
the last decade.\12\ Just below the 3 percent threshold are three 
source categories: Oil and Natural Gas, Petroleum Refineries, and 
Industrial-Commercial-Institutional Steam Generating Units (i.e., 
``Boilers''). There are no other source categories with GHG emissions 
between 1.5 percent and the 3 percent. By using a threshold of 3 
percent of the U.S. GHG emissions (i.e., only including EGUs above the 
threshold), the EPA will effectively be covering 43 percent of the U.S. 
stationary source GHG emissions via regulation of a single source 
category. If the EPA were to instead set a threshold between the other 
identified breakpoint--between 1.5 percent and 2.5 percent of U.S. GHG 
emissions--the EPA observes that this threshold would lead to a 
relatively modest increase in the stationary source U.S. GHG emissions 
that would be regulated of an additional 13 percent (for a total of 56 
percent of U.S. stationary source GHG emissions).\13\ In addition, 
regulation of the additional source categories that comprise 13 percent 
of U.S. emissions would eliminate only a portion of those emissions. 
With an even lower threshold of significance set at 1.0 percent of U.S. 
GHG emissions, there would be significantly more source categories 
covered (about 10 based on the EPA estimates) above the threshold but 
likely would include an even more modest increase in stationary source 
GHGs that would cover 60 percent of U.S. stationary source GHGs. Under 
this framework, the EPA is basing a decision to apply a threshold of 3 
percent on the relative contribution of regulating source categories 
that contribute significantly to the overall impact of climate change. 
To that end, the temperature impact associated with the hypothetical 
elimination of all source categories above a 3 percent threshold 
corresponds to a hypothetical global mean temperature reduction of 
0.049 degrees Celsius ([deg]C) (approximately 0.1 degree Fahrenheit, 
the calculated effect in 2100 of removing 1,780 million metric tons 
(MMT) of CO2 emissions each year from 2020 through 2100) 
from source categories above that threshold (i.e., just EGUs). 
Eliminating the next largest source category (i.e., Oil and Gas 
Processing and Production) would only generate an additional 
hypothetical global mean temperature reduction of less than 0.01[deg]C 
and even smaller source categories correspondingly contribute less to 
global temperature. The EPA is making the decision that the threshold 
for a significance determination for U.S. GHG emissions to be in the 
form of a percentage. A percentage is a metric that measures the 
relative contribution to the whole and, in this action, the EPA 
believes that it is appropriate to measure and evaluate significant 
contribution of U.S. GHG emissions as a relative contribution to the 
whole of GHG emissions in the U.S. The EPA is determining that a 
threshold in the form of a percentage is both reasonable and more 
appropriate for making the significance determination in this rule 
based on a percent's relative nature. This is important because the 
trajectory of U.S. GHG emissions is trending down. As overall emissions 
decrease over the course of time, a source category's relative 
contribution to GHGs may not have changed or may have even increased 
based on GHG reductions in other source categories and sectors. A 
relative percentage threshold recognizes that the EPA may later 
determine a source category is significant based on these 
circumstances, because a source category's emissions may eventually 
exceed the threshold even though it is currently below the threshold.

[[Page 2554]]

Accordingly, a percentage threshold allows the EPA, over time, to 
always focus on the source categories with the potential to have the 
greatest impact. The framework on which EPA bases its decision today 
is, therefore, amenable to future use, which augurs in favor of the 
framework's use to make today's finding.
---------------------------------------------------------------------------

    \12\ See 79 FR 34960 and 80 FR 64510.
    \13\ Note that one of those ``next three largest'' source 
categories is oil and natural gas. In the recently finalized policy 
package, the EPA found that regulation of GHGs from this source 
category is unnecessary as it is currently being controlled by 
regulation of volatile organic compounds. See 85 FR 57018, 57030 
(September 14, 2020).
---------------------------------------------------------------------------

    The EPA is introducing in this action that a threshold in the form 
of a percentage is both reasonable and more appropriate for making a 
significance determination for GHGs based on a percent's relative 
nature. A tonnage threshold is a static metric that would not change 
over time. As previously described, the trajectory of U.S. GHG 
emissions is trending down. As emissions decrease over the course of 
time, it is likely that source categories that were once above any 
static threshold will fall below such a threshold. Even though a source 
category may reduce overall U.S. GHG emissions, that source category's 
relative contribution to GHGs may not have changed or may have even 
increased based on GHG reductions in other source categories and 
sectors. Additionally, if emissions do decrease over time, the use of a 
tonnage threshold potentially results in no source category meeting the 
criteria for significance, even if collectively the U.S.GHG emissions 
continue to pose a danger to public health or welfare.
    It should be noted that the U.S. GHG emissions of the EGU source 
category are more than an order of magnitude larger than the emissions 
threshold in the framework, representing 43 percent of U.S. stationary 
source GHG emissions. The EPA believes that it is possible for source 
categories with GHG emissions substantially larger than the threshold 
to be deemed significant on the basis of the primary criterion alone 
(i.e., magnitude of emissions) and without consideration of the 
secondary criteria described elsewhere in this notice.
3. Tiers of Source Categories Based on GHG Emissions
    As noted previously, the primary criterion in evaluating the 
significance of a source category is, again, the relative magnitude of 
the U.S. GHG emissions. The EPA believes that NSPS source categories 
may be grouped into three tiers on the basis of magnitude of the U.S. 
GHG emissions, as follows:

    (1) Source category with GHG emissions substantially above the 
threshold. This source category has emissions of a large enough 
magnitude that a determination of significance can be made on the 
basis of the magnitude of emissions alone. As discussed later in 
this document, this tier is comprised solely of the EGUs source 
category; in other words, EGUs do not require consideration of the 
secondary criteria in order to determine significance.
    (2) Source categories with an intermediate magnitude of the U.S. 
GHG emissions (i.e., those with emissions above the threshold but 
less than the quantity emitted by the EGU source category). For 
source categories with emissions above the threshold, evaluation of 
the magnitude of the U.S. GHG emissions is inconclusive. Rather, a 
significance determination requires an examination of the source 
category's magnitude of emissions combined with a more detailed look 
at the secondary criteria discussed elsewhere in this document.
    (3) Source categories with a small magnitude of GHG emissions 
(i.e., those with emissions below the threshold). Source categories 
with a small magnitude of emissions will be deemed insignificant 
based on evaluation of the primary criterion alone, without detailed 
consideration of any secondary criteria.

D. Secondary Criteria for Determining Significance

    As described above, the EPA is determining that the U.S. GHG 
emissions from a source category are the primary and most important 
criterion for making a determination of significance for a source 
category. However, there may be instances where the U.S. GHG emissions 
from a source category do not give a comprehensive enough picture to 
make a determination of significance. The threshold that the EPA has 
described above in Section IV.B would provide a clear indication that 
the U.S. GHG emissions from source categories below that threshold are 
necessarily insignificant. However, under this framework, for any 
source category that is above that threshold, there are other source-
category specific considerations that should be evaluated in addition 
to GHG emissions when making a determination of significance.\14\ For 
that reason, the EPA will consider other, secondary, criteria in the 
evaluation of significance for certain source categories. These other 
criteria are described in the subsequent subsections. It is important 
for the EPA to consider secondary criteria in the evaluation of 
significance for certain source categories because the criteria provide 
unique context to the source category beyond the information provided 
by the magnitude of the source category's GHG emissions.
---------------------------------------------------------------------------

    \14\ Although there is no source category other than EGUs above 
the 3% threshold, because the threshold is a percentage and as 
previously described, other source categories may move into this 
tier as overall GHG emissions decrease and other source category 
emissions increase.
---------------------------------------------------------------------------

1. Evaluation and Context of GHG Emissions
    Under the introduced framework, the evaluation of the magnitude of 
the U.S. GHG emissions from a source category is a substantial 
indicator of whether a source category is significant, but in the 
specific instance of source categories that have greater GHG emissions 
than the threshold, an evaluation based on the magnitude of the U.S. 
GHG emissions may be inconclusive. Within the introduced framework, 
there are other emissions-based metrics that must be evaluated to 
clarify and make a significance determination for these source 
categories.
a. Source Category Trends
    An important criterion that can help illuminate and contextualize a 
significance determination is an evaluation of the trends in emissions 
and number of designated facilities within a source category. 
Primarily, the EPA is evaluating whether a source category is on a 
trajectory of the U.S. GHG emission decline. If the source category, as 
a whole, is decreasing its GHG emissions, an explanation for why it is 
on the decline may aid in making a significance determination. In one 
scenario, if the source category is decreasing emissions because the 
source category is declining in production or other output (e.g., due 
to decreasing demand for goods or other market conditions, due to 
relocation overseas, or due to the cumulative effect of regulations), 
it may lend towards an insignificance determination as the emissions 
are already declining and expected to continue to decline even without 
further regulation. In a separate scenario, if a source category's GHG 
emissions are declining due to increased efficiency and updated 
technology, it may lend towards a determination of significance. This 
would allow the EPA the ability to regulate the source category in 
order to ensure that efficiency and technology improvements become 
standard across the source category through both an NSPS (111(b) 
regulation) for new, modified and reconstructed sources and an emission 
guidelines (111(d) regulation) for existing sources.
    In a scenario in which the EPA were to find a source category to be 
growing in either emissions or number of designated facilities (or 
both), it could lend towards that source category being found to be 
significant. This would allow EPA to regulate and mitigate emissions 
from new, modified and/or reconstructed designated facilities

[[Page 2555]]

within that source category under CAA section 111(b) (i.e., via a 
NSPS).
    If the EPA were to evaluate the trend in the number of designated 
facilities and emissions of a source category, it might show a static 
number of existing facilities with a constant or slightly increasing 
quantity of the U.S. GHG emissions. In this scenario, there may be 
little utility in determining significance for that source category and 
consequentially developing a NSPS as there are little to no emissions 
that would be subject to such a standard. However, creating a NSPS for 
a source category and pollutant is a necessary predicate to regulating 
existing sources under CAA section 111(d). Hence, in the scenario of a 
static number of existing facilities, a finding of significance for the 
source category may be warranted as it would allow eventual regulation 
of a group of existing source categories. Under this framework, the EPA 
expects the prospect of regulating a source category under CAA section 
111(d) for existing sources to be a compelling reason for determining 
significance.
b. Source Category Emissions With Global Context
    Another important criterion that the EPA considers, as a secondary 
factor, is the relative contribution of GHG emissions from the U.S. in 
a specific source category compared to worldwide emissions of similar 
sources. As previously described, Section 111(b)(1)(A) of the CAA 
states that the Administrator shall include source categories that 
contribute significantly to endangerment of health and welfare. When 
evaluating a global pollutant such as GHGs, the EPA views the impact of 
domestic emissions from domestic sources as a more germane 
consideration when determining whether a pollutant contributes 
significantly to endangerment of health or welfare. Because every ton 
of GHG contributes to the global problem, a domestic ton will still 
have some impact in the U.S. Accordingly, it is reasonable for the EPA 
to evaluate whether a source category is well-regulated internationally 
and whether the U.S. emissions from that sector make up a relatively 
large share of GHG emissions on a worldwide scale, as such evaluation 
in turn would inform whether U.S. emissions are significantly 
contributing to domestic impacts. If the emissions from the U.S. are 
comparatively a large contribution to source category/sector emissions 
worldwide, it may lend towards a finding of significance for the source 
category based on the U.S.'s substantial global contribution to the 
source category. If, however they are relatively small, it would 
suggest less benefit from the EPA regulation of that source category.
    The EPA also considers, as one of the secondary criteria, an 
evaluation of whether a source category is vulnerable to being trade 
exposed (i.e. whether the source category is constrained in the 
sources' ability to pass through carbon costs due to actual or 
potential international competition). The EPA evaluates whether 
regulation of the source category would create a financial incentive 
for that source category/industry to move into, or increase production 
in, another country. This could be manifested as either a shift in 
production to facilities internationally or a complete closure of 
existing designated facilities in the U.S. It is not the EPA's 
intention in regulating source categories to drive production from the 
U.S. to other countries, and there is an environmental concern in 
pushing industries to other international locations. This concern is 
based on the potential for these new international emissions to 
increase compared to the corresponding displaced U.S. emissions.\15\ 
While this is always a concern for the EPA in the regulation of 
industry within the U.S., it even more pronounced with the 
consideration of GHG emissions. As discussed, previously, the U.S. GHG 
emissions are a global pollutant that also have domestic impacts. As 
such, if a smaller quantity of domestic GHG emissions would be 
displaced, due to a regulation, by a greater quantity of international 
GHG emissions it may support a finding of insignificance for a given 
source category. This would occur if the U.S. sources are already 
significantly lower emitting in GHG emissions than sources in other 
countries. It should also be noted that source categories whose sources 
in the U.S. make up a relatively smaller proportion of the world's 
emissions from corresponding international sectors may be particularly 
vulnerable to being trade exposed as there is likely a greater 
international capacity to absorb the displaced U.S. production.
---------------------------------------------------------------------------

    \15\ If U.S. production shifted overseas to a jurisdiction that 
has laxer environmental regulations, for a global pollutant such as 
mercury or GHGs, there could be both increased local environmental 
and health impacts at the new overseas location and domestic impacts 
to the U.S. resulting from the increased U.S. GHG emissions.
---------------------------------------------------------------------------

    Given the global nature of GHG emissions, assessing and 
understanding the estimated potential net emissions impact of GHG 
control technologies provides useful context in which to consider the 
significance of a given set of GHG emissions In addition, there may 
also be value in evaluating and considering the technology with the 
associated source category (i.e., intrinsic to the process of the 
source category)--a prime example of reductions associated with this 
evaluation might be assessing the likely impacts of efficiency 
improvements. From a public welfare and human health perspective, 
targeting source categories that provide the largest overall possible 
scope for emissions reductions could be an intrinsic part of 
determining the significance of a given magnitude of emissions. Thus, 
the EPA is determining that it is appropriate in a given instance to 
consider feasible technologies (including efficiency improvements) for 
further context in the Agency's determination of significance of a 
source category's overall emissions. Here, the magnitude of GHG 
emissions from EGUs coupled with the reductions available through 
efficiency improvements supports the EPA's determination of 
significance.
d. Temporal Evaluation of Criteria
    As introduced in this framework, the evaluation of the secondary 
criteria is not intended to be performed in isolation. Rather, the EPA 
considers the weight of evidence of all the factors (both primary and 
secondary) to make an informed and comprehensive decision as to whether 
a source category that exceeds the 3-percent threshold contributes 
significantly to the U.S. GHG emissions. The consideration of criteria 
also has a temporal consideration to a significance determination. A 
source category's determination can be reevaluated in the future as the 
status and criteria described here may have changed for that source 
category. For example, the technology to adequately regulate GHGs from 
a source category may not be readily available at this time, but in the 
future that technology may become more broadly available causing the 
EPA to then make a SCF.

E. Significant Contribution Finding for EGUs

    As noted above, the Agency is finalizing a determination that GHG 
emissions from EGUs \16\ contribute significantly to dangerous air 
pollution. The primary criterion in determining

[[Page 2556]]

whether to make a SCF is the magnitude of GHG emissions from a given 
source category. It is readily apparent that EGUs emit a uniquely large 
amount of GHGs compared to all other categories of stationary sources. 
The EPA made this clear in the 2015 Rule, quoted above, and reiterated 
it in the 2020 Oil & Gas Rule: ``the unique CO2 emissions 
profile of fossil fuel-fired EGUs should be noted: the volume of 
emissions from EGUs dwarfs the amount of GHG emissions from every other 
source category.'' 85 FR 57039, n.49.
---------------------------------------------------------------------------

    \16\ For this purpose, EGUs include the affected sources in the 
combined source category for boilers and turbines. In the 2015 Rule, 
the EPA ``combine[d] the two categories of EGUs--steam generators 
and combustion turbines--into a single category of fossil fuel-fired 
EGUs for purposes of promulgating standards of performance for 
CO2 emissions.'' 80 FR 64529 (2015 Rule).
---------------------------------------------------------------------------

    Although GHG emissions from EGUs have fallen since the EPA 
promulgated the 2015 Rule, they still remain uniquely large among 
stationary source categories. The EPA's Inventory of U.S. Greenhouse 
Gas Emissions \17\ indicates that, as of 2018, the Electric Power 
sector directly emitted 1,778.5 MMT of GHGs.\18\ This amount was more 
than twice the amount of GHGs emitted by all other industrial sources 
combined and more than all other industrial, commercial, and 
residential stationary combustion sources combined.\19\ In addition, 
direct GHG emissions from EGUs account for approximately 27 percent of 
total U.S. GHG emissions and 43 percent of U.S. stationary source 
emissions. The direct GHG emissions from EGUs account for approximately 
4 percent of total worldwide GHG emissions and are greater than the 
emissions of all but four countries.\20\ These facts confirm that at 
current emission levels, EGUs have measurable impacts on both the U.S. 
contribution to GHG emissions and the worldwide total GHG emissions and 
continue to be uniquely large stationary source emitters of GHGs. It 
should be noted that if domestic EGUs no longer emitted any GHG 
emissions, there would be a measurable impact on worldwide GHG 
emissions and between 2020 and 2100, there would be a reduction in the 
projected increase in global temperatures by 0.049 degrees Celsius 
([deg] C).
---------------------------------------------------------------------------

    \17\ See Table 3-9, Inventory of U.S. Greenhouse Gas Emissions 
and Sinks: 1990-2018, Report 430-R-20-002, April 13, 2020, https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2018.
    \18\ The global warming potential (GWP) of a greenhouse gas is 
defined as the ratio of the accumulated radiative forcing within a 
specific time horizon relative to that of the reference gas 
CO2. Total GHG emissions are the GWP-weighted emissions 
of all GHG emissions and reported in million metric tons of 
CO2 equivalent (MMT CO2e.).
    \19\ See Table 3-9, Inventory of U.S. Greenhouse Gas Emissions 
and Sinks: 1990-2018, Report 430-R-20-002, April 13, 2020, https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2018.
    \20\ In 2016, worldwide GHG emissions were estimated to have 
been 49.4 gigaton (Gt) CO2e. The GHG emissions of China, 
India, Russia, and Indonesia are 11,577, 3,235, 2,391, and 2,229 MMT 
CO2e respectively. https://www.wri.org/blog/2020/02/greenhouse-gas-emissions-by-country-sector.
---------------------------------------------------------------------------

    Because EGUs represent by far the largest stationary source of GHGs 
from combustion of fossil fuels, the EPA believes that this is the most 
appropriate place for the EPA, states, and sources to devote resources 
to reducing GHGs from stationary sources. Indeed, this uniquely large 
magnitude of emissions is the reason over the last 8 years, the Agency 
has devoted significant effort to determine how to best reduce GHGs 
from EGUs. Because EGUs are a relatively large U.S. source of emissions 
in an overall large pool of international EGU sources, regulation over 
time could help produce practices and technologies that have 
application to EGUs worldwide.
    It is noteworthy that GHG emissions from EGUs are approximately an 
order of magnitude greater than the estimated emissions of the second 
largest stationary source category of GHGs attributed to combustion, 
industrial boilers. Because the magnitude of GHG emissions from EGUs is 
large compared to other stationary sources, this makes them clearly 
significant even without detailed consideration of other factors. As 
mentioned earlier, the EPA is also introducing a framework under which 
a source category that emits above a threshold of 3 percent of U.S. 
stationary source GHG emissions may contribute significantly to 
dangerous GHG air pollution. For those source categories above that 
threshold, the EPA is also determining that consideration of certain 
secondary criteria may, collectively, also inform the evaluation of 
whether a source category should be considered to significantly 
contribute. However, within this framework, that analysis of secondary 
criteria is not necessary in the case of EGUs, due to the 
overwhelmingly large emissions of the source category; it is clear that 
controlling GHG emissions from the EGU source category will be 
necessary to appropriately address dangerous air pollution. This 
conclusion is consistent with the EPA's 2018 Proposal where the Agency 
explained that if the EPA was required to evaluate significance, EGUs 
would be considered significant.
1. Secondary Criteria
    The EPA is determining that the uniquely large GHG emissions from 
EGUs makes a finding of significant contribution and regulation 
appropriate by itself. Under the introduced framework, while the EPA 
does not think it is necessary to consider secondary criteria because 
of the uniquely large emissions from the EGU source category, as 
explained below, the EPA would make the same determination even if it 
did consider those criteria.
a. Source Category Trends
    As mentioned earlier, an important criterion is the evaluation of 
the trends in emissions and number of designated facilities within a 
source category, such that the EPA can evaluate whether a source 
category is on a trajectory of U.S. GHG emission decline.
    While electricity demand is projected to increase the U.S., due to 
the increased use of less carbon intensive generation technologies and 
more efficient generation, GHG emissions from the power sector are 
projected to remain relatively steady for the foreseeable future. 
However, EGUs are projected to remain the single largest stationary 
source of GHG emissions, and while the Agency expects few, if any, new 
coal-fired EGUs will be built to meet the demand for electricity, coal-
fired EGUs are expected to continue to supply electricity and emit 
significant GHG emissions for the foreseeable future.\21\ The EGU 
source category also includes stationary combustion turbines. The EPA 
expects new simple cycle and combined cycle combustion turbine EGUs 
will be built in the future and that the existing fleet of combustion 
turbines will continue to operate.\22\ Therefore, efficient generation 
technology could eventually become standard for all new and existing 
EGUs. Consequently, the EPA would consider the source category trends 
as supporting the regulation of GHG emissions from EGUs.
---------------------------------------------------------------------------

    \21\ According to Table 8 of the Annual Energy Outlook (AEO) 
2020, while coal fired generation will decline between 2019 and 2025 
from 959 billion kWh to 709 billion kWh, generation from coal-fired 
EGUs is projected to subsequently remain relatively steady through 
2050.
    \22\ According to Table 8 of the AEO 2020, natural gas fired 
generation is projected to increase from 1,322 billion kWh to 1,629 
billion kWh.
---------------------------------------------------------------------------

b. Source Category Emissions With Global Context
    The EPA is also determining that it can consider, as a secondary 
criterion, the relative contribution of GHG emissions from the U.S. in 
the specific source category compared to worldwide emissions of similar 
sources. Accordingly, the EPA evaluates whether a source category is 
well-regulated internationally and whether the U.S. emissions from that 
sector make up a relatively large share of global GHG emissions, as 
such evaluation in turn would inform whether U.S. emissions are 
significantly contributing to

[[Page 2557]]

domestic impacts. In this instance, this criteria points towards a 
finding of significance given that U.S. EGUs make up a sizeable portion 
(13 percent of the emissions) from EGUs worldwide.\23\
---------------------------------------------------------------------------

    \23\ U.S. EGU emissions from the Inventory of U.S. Greenhouse 
Gas Emissions and Sinks: 1990-2018, Report 430-R-20-002, April 13, 
2020, https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2018. Worldwide EGU emissions from the 
International Energy Agency estimates IEA (2020), CO2 
Emissions from Fuel Combustion, https://www.iea.org/subscribe-to-data-services/co2-emissions-statistics.
---------------------------------------------------------------------------

    As mentioned earlier in this notice, the EPA is also introducing 
that one of the secondary criteria is an evaluation of whether a source 
category is vulnerable to being trade exposed (i.e., whether the source 
category is constrained in its ability to absorb regulatory costs due 
to actual or potential international competition). Concerns about 
international competition would not impact the Agency's decision to 
regulate EGUs because electricity must be transported over power lines 
and it is not as easy to relocate or shift production locations as it 
is for other source categories. The ability to locate generation in 
Mexico and Canada and transmit the power to the U.S. is limited because 
of constraints on existing transmission lines and the expense to build 
additional transmission capacity. The only additional transmission 
capacity currently being considered is for electricity generated from 
hydroelectric power in Canada to supply power to New England. Since 
this electricity has a low carbon intensity, it would not contribute to 
an overall increase in GHG emissions. Furthermore, the emission 
standards in this rule will not increase the costs of electricity from 
a new coal-fired EGU such that it might be financially advantageous to 
locate new production internationally to countries with less stringent 
regulations. If international competition were a concern, the Agency 
would compare the forecast GHG emissions from international sources (in 
this case, EGUs in Canada and Mexico) against the forecast GHG 
emissions from domestic sources (in this case domestic EGUs) in both 
the absence of and implementation of the NSPS. In addition, since few, 
if any, new coal-fired EGUs are forecast to be built in the U.S., the 
standards in this final rule will not impact electricity prices to end 
users to an extent that other industries would be incentivized to 
relocate internationally due to increased electricity costs. Therefore, 
domestic reductions in GHG emissions from regulating EGUs will not be 
offset by increased international GHG emissions. In contrast, for 
source categories that supply raw materials to other domestic source 
categories, the impact of international competition on those source 
categories and the resultant GHG impacts could be considered when 
determining an appropriate NSPS. It is conceivable that an overly 
stringent NSPS could result in an increase in global GHG emissions, if 
the increase in international emissions is greater than the reduction 
in domestic emissions.

V. Summary of Cost, Environmental, and Economic Impacts

A. What are the affected facilities?

    This rule takes final action affecting fossil fuel-fired EGUs. 
These EGUs take two forms that are relevant for present purposes: Steam 
generating units (utility boilers and gasification units) and 
stationary combustion turbines. Fossil fuel-fired steam generating 
units can burn natural gas, oil, or coal. However, coal is the dominant 
fuel for electric utility steam generating units. Coal-fired steam 
generating units are primarily either PC or fluidized bed (FB) steam 
generating units.\24\ At a PC steam generating unit, the coal is 
crushed (pulverized) into a powder to increase its surface area. The 
coal powder is then blown into a steam generating unit and burned. In a 
fossil fuel-fired steam generating unit using FB combustion, the solid 
fuel is burned in a layer of heated particles suspended in flowing air. 
Power can also be generated from coal or other fuels using gasification 
technology. An Integrated Gasification Combined Cycle (IGCC) unit 
gasifies coal or petroleum coke to form a synthetic gas (or syngas) 
composed of carbon monoxide (CO) and hydrogen (H2), which 
can be combusted in a combined cycle system to generate power. 
Stationary combustion turbines include both fossil fuel-fired simple 
cycle and combined cycle combustion turbine EGUs.
---------------------------------------------------------------------------

    \24\ Fossil fuel-fired utility steam generating units (i.e., 
boilers) are most often operated using coal as the primary fuel. 
However, some utility boilers use natural gas and/or fuel oil as the 
primary fuel.
---------------------------------------------------------------------------

B. What are the air quality impacts?

    The EPA does not anticipate that this final rule for fossil-fuel-
fired EGUs will result in significant CO2 emission changes.

C. What are the energy impacts?

    This final rule for fossil-fuel-fired EGUs is not anticipated to 
have an effect on the supply, distribution, or use of energy.

D. What are the cost impacts?

    The EPA does not believe that this final rule for fossil-fuel-fired 
EGUs will have compliance costs associated with it.

E. What are the economic impacts?

    The EPA does not anticipate that this final rule for fossil-fuel-
fired EGUs will result in economic or employment impacts. Likewise, the 
EPA believes this rule will not have any impacts on the price of 
electricity, employment or labor markets, or the U.S. economy.

F. What are the benefits?

    The EPA does not anticipate emission changes resulting from the 
final rule for fossil-fuel-fired EGUs.

VI. Statutory and Executive Order Reviews

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

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

    This action is a significant regulatory action that was submitted 
to the Office of Management and Budget (OMB) for review because it 
raises novel legal or policy issues. Any changes made in response to 
OMB recommendations have been documented in the docket.

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

    This action is not expected to be an Executive Order 13771 
regulatory action. There are no quantified cost estimates for this 
final rule because the EPA does not anticipate this action to result in 
costs or cost savings.

C. Paperwork Reduction Act (PRA)

    This action does not impose any new information collection burden 
under the PRA. OMB has previously approved the information collection 
activities contained in the existing parts 75 and 98 regulations and 
has assigned OMB control numbers 2060-0626 and 2060-0629, respectively.

D. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. In 
making this determination, the impact of concern is any significant 
adverse economic impact on small entities. An agency may certify that a 
rule will not have a significant economic impact on a

[[Page 2558]]

substantial number of small entities if the rule relieves regulatory 
burden, has no net burden, or otherwise has a positive economic effect 
on the small entities subject to the rule. The EPA expects there to be 
few, if any, new, modified, or reconstructed coal-fired EGUs. As such, 
this final rule would not impose significant requirements on those 
sources, including any that are owned by small entities. The EPA has, 
therefore, concluded that this action will have no net regulatory 
burden for all directly regulated small entities.

E. Unfunded Mandates Reform Act (UMRA)

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

F. Executive Order 13132: Federalism

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

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

    This action does not have tribal implications, as specified in 
Executive Order 13175. It would neither impose substantial direct 
compliance costs on tribal governments, nor preempt Tribal law. The EPA 
is aware of three coal-fired EGUs located in Indian Country but is not 
aware of any EGUs owned or operated by tribal entities. The EPA notes 
that this action would affect only existing sources such as the three 
coal-fired EGUs located in Indian Country if those EGUs were to take 
actions constituting modifications or reconstructions as defined under 
the EPA's NSPS regulations. However, as previously stated, the EPA 
expects there to be few, if any, new, reconstructed, or modified EGUs. 
Thus, Executive Order 13175 does not apply to this action.
    Consistent with the EPA Policy on Consultation and Coordination 
with Indian Tribes, the EPA offered consultation with tribal officials 
during the development of this action; however, the Agency did not 
receive a request for consultation. The EPA held meetings with tribal 
environmental staff during the public comment period to inform them of 
the content of the proposed rule and to encourage them to submit 
comments on the proposed rule.

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

    The EPA interprets Executive Order 13045 as applying only to those 
regulatory actions that concern health or safety risks that the EPA has 
reason to believe may disproportionately affect children, per the 
definition of ``covered regulatory action'' in section 2-202 of the 
Executive Order. This action is not subject to Executive Order 13045 
because it does not concern an environmental health or safety risk.

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

    This action is not a ``significant energy action'' because it is 
not likely to have a significant adverse effect on the supply, 
distribution, or use of energy and has not otherwise been designated as 
a significant energy action by the Administrator of the Office of 
Information and Regulatory Affairs (OIRA). This final action is not 
anticipated to have impacts on emissions, costs, or energy supply 
decisions for the affected electric utility industry.

J. National Technology Transfer and Advancement Act (NTTAA)

    This rulemaking does not involve technical standards.

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

    The EPA believes that this action does not have disproportionately 
high and adverse human health or environmental effects on minority 
populations, low-income populations, and/or indigenous peoples, as 
specific in Executive Order 12898 (59 FR 7629, February 16, 1994), 
because it does not affect the level of protection provided to human 
health or the environment. As previously stated, the EPA expects that 
few, if any, coal-fired EGUs would be affected by this action.

L. Congressional Review Act (CRA)

    This action is subject to the CRA, and the EPA will submit a rule 
report to each House of the Congress and to the Comptroller General of 
the United States. This action is not a ``major rule'' as defined by 5 
U.S.C. 804(2).

Andrew Wheeler,
Administrator.
[FR Doc. 2021-00389 Filed 1-12-21; 8:45 am]
BILLING CODE 6560-50-P