fossil-fired electrical generation available in 2022. We solicit
comment on whether we have identified all of the EGUs relying on
paragraph (2) of the definition of ``startup'', as well as their
associated retirement dates as reported to the Department of Energy's
EIA. Commenters, particularly owners or operators of affected EGUs,
should provide us with corrected information as, or if, necessary.
Despite comments from EGU owners or operators and their industry
representatives opposing use of paragraph (1) of the definition of
``startup'', the owners or operators of coal- and oil-fired EGUs that
generated over 98 percent of electricity in 2022 have made the
requisite adjustments, whether through greater clean fuel capacity,
better tuned equipment, better trained staff, a more efficient or
better design structure, or a combination of factors, to be able to
meet the requirements of paragraph (1) of the definition of
``startup.''

    Consistent with the MACT emission standard setting requirement for
using the average of the best performing 12 percent of sources to
establish emission standards, we propose to remove the alternative work
practice standards, i.e., those contained in paragraph (2) of the
definition of ``startup'', from the rule. As demonstrated by the
majority of EGUs currently relying on the work practice standards in
paragraph (1) of the definition of ``startup'', we believe such a
change is achievable by all EGUs; further, we expect such a change
would result in little to no additional expenditure since the
additional recordkeeping and reporting provisions associated with the
work practice standards of paragraph (2) of the definition of
``startup'' were more expensive than the requirements of paragraph (1)
of the definition of ``startup.'' We solicit comment on our proposal to
remove the work practice standards of paragraph (2) of the definition
of ``startup.''
2. Removing Non-Hg Metals Limits
    The current MATS rule contains individual and total non-Hg metals
emissions limits, as well as fPM emission limits. Those fPM emission
limits serve as alternative emission limits because fPM was found to be
a surrogate for either individual or total non-Hg metals emissions. As
explained and used above to quantify individual and total non-Hg metals
reductions from our proposed fPM emission limit revision, the
relationship between individual and total non-Hg metals and fPM was
determined by EGU fuel type and control device using data collected by
the 2010 ICR.\53\ While EGU owners or operators have the ability to use
individual or total non-Hg metals emissions as the compliance method
for the 358 EGUs when this action takes effect and with generation of
at least 25 MW,\54\ we are aware of just one owner or operator who
provides non-Hg metals data--both individual and total--along with fPM
data for compliance purposes for one waste coal-fired EGU with
generating capacity of 46.1 MW. Given that owners or operators of the
other EGUs applicable to MATS have chosen to demonstrate compliance
with only the fPM emission limit, we propose to remove the non-Hg
metals emission limits--both individual and total--from MATS. Removal
of the non-Hg metals emission limits renders the LEE option for non-Hg
metals (individual and total) obsolete and the EPA is proposing to
remove those standards as well. Removal of the non-Hg metals emissions
limits simplifies the compliance determination path for EGU owners or
operators and reduces the amount of regulatory text, making the rule
clearer yet continuing to ensure that non-Hg metals emissions remain
below limits on an ongoing basis, particularly when the fPM is measured
as proposed with PM CEMS, given that non-Hg metals emissions provided
for one EGU are obtained via quarterly stack testing. We solicit
comment on the number of EGUs that currently rely on non-Hg metals
emissions measurement for MATS compliance purposes; to the extent that
other EGU owners or operators rely on non-Hg metals emissions for
compliance purposes, please be sure to identify each EGU, its nameplate
generating capacity, its anticipated or announced retirement date (if
applicable), and its Office of Regulatory Information Systems (ORIS)
Code. We solicit comment on our proposal to remove the non-Hg metals
emission limits from all existing MATS-affected EGUs.
---------------------------------------------------------------------------

    \53\ See Emission Factor Development for RTR Risk Modeling
Dataset for Coal- and Oil-fired EGUs, available at https://www.regulations.gov at Docket ID No. EPA-HQ-OAR-2018-0794-0010.
    \54\ Data obtained from the Emissions and Generation Resource
Integrated Database (eGRID), available at https://www.epa.gov/egrid.
---------------------------------------------------------------------------

    If we were to change our position by deciding against removing the
non-Hg metals emission limits from MATS and if our proposal to revise
the fPM emission limits was accepted, we would develop non-Hg emission
limits by multiplying the revised fPM emission limit by each individual
(or total) non-Hg PM ratio identified in the aforementioned Emission
Factor Development for RTR Risk Modeling Dataset for Coal- and Oil-
fired EGUs memorandum.\55\ The resulting values would become the
individual non-Hg metals emission limits; their sum would become the
total non-Hg metals emission limit. We solicit comment on our proposed
approach to develop non-Hg metals emission limits in the event that our
preferred approach--removing the non-Hg metals emission limits--is not
selected. Note that should our proposed approach to remove non-Hg
metals emission limits from MATS not be finalized, we would need to
adjust the compliance determination method because the current
quarterly emissions testing would not be consistent with the continuous
monitoring and compliance determination method afforded by acceptance
of our proposal to require use of PM CEMS for compliance with the fPM
emission limit. At least one CEMS manufacturer offers a multi-metals
instrument that would be suitable or could be adjusted to account for
appropriate detection levels for ongoing compliance purposes. In
addition, were our proposal to remove non-Hg metals from the rule not
finalized, very frequent emissions testing, perhaps on the order of
weekly, might be able to provide more information on compliance status.
While not continuous, as provided by CEMS, such information would be
more frequent than provided by the quarterly emissions testing required
by the rule. We solicit comment on appropriate means to determine
compliance with non-Hg metals emission limits, provided our proposed
approach--removal of non-Hg metals emission limits--is not finalized.
Please include in your comments information related to the frequency of
collected data, the continuity of data supplied by your suggested means
of compliance, and initial and ongoing annual costs of your suggested
means of compliance.
---------------------------------------------------------------------------

    \55\ See https://www.regulations.gov at Docket ID No. EPA-HQ-
OAR-2018-0794-0010.
---------------------------------------------------------------------------

3. Removing Use of PM CPMS for Compliance Determinations
    Use of PM CPMS for compliance purposes appears to be limited to
four EGUs at one site in South Carolina, and these EGUs account for
less than 0.5 percent of all EGUs in operation. According to submitted
reports, each of the EGUs relies on an instrument (Sick Maihak RWE-200)
which provides a milliamp signal that is used to develop an ongoing
operating limit; this instrument is advertised by its maker to be able
to serve as a PM CEMS with little to no modification, meaning that the
instrument can provide direct measurement of fPM in terms of the
emission standard--pounds per million BTU. Given that PM CPMS use costs
more than PM CEMS use, that PM CPMS does not provide continuous values
in terms of the emission standard, that PM CPMS is rarely in use among
EGUs, and that the existing PM CPMS can be used as PM CEMS, we propose
to remove the ability to use PM CPMS for compliance purposes in MATS.
The EPA solicits comment on the use of PM CPMS for compliance purposes;
to the extent there are other EGU owners or operators using PM CPMS,
commenters should identify each EGU, along with its ORIS code and MW
nameplate capacity, as well as the PM CPMS manufacturer and model in
use. The EPA also solicits comment on the proposal to replace PM CPMS
with PM CEMS for compliance use in MATS; when providing comments,
please provide detailed costs--including initial instrument cost,
installation cost, and operating and maintenance costs--as well as a
description of ongoing

operating activities from those EGUs with existing PM CPMS used for
compliance purposes.

E. What compliance dates are we proposing, and what is the rationale
for the proposed compliance dates?

    The EPA is proposing to revise the fPM emission limit for existing
coal-fired EGUs and the Hg emission limit for lignite-fired EGUs. The
EPA is proposing up to 3 years after the effective date for EGUs
subject to MATS to meet these new emission limits. However, the EPA
solicits comment on whether more than 1 year is needed to comply
considering the potential need to upgrade control systems. In addition,
the EPA is proposing that affected EGUs demonstrate compliance with the
fPM emission limit using PM CEMS, removing the alternative compliance
options. Sources must demonstrate that compliance has been achieved, by
conducting the required performance tests, and other activities as
specified in 40 CFR part 63, subpart UUUUU, including a minimum
sampling collection time of 3 hours per run, no later than 3 years
after the promulgation date. To demonstrate initial compliance using PM
CEMS, the initial performance test consists of 30-boiler operating
days. If the PM CEMS is certified prior to the compliance date, the
test begins with the first operating day on or after that date. If the
PM CEMS is not certified prior to the compliance date, the test begins
with the first operating day after certification testing is
successfully completed. Continuous compliance with the revised fPM
emission limit is required to be demonstrated on a 30-boiler operating
day rolling average basis, defined in 40 CFR 63.10021(b), as the
arithmetic average emissions rates over the last continuous 30 days
provided the boiler was operating. The EPA proposes to remove the use
of PM CPMS for compliance determinations and the non-Hg metal emission
limits--both individual and total--3 years after the promulgation date.
The EPA considers 3 years to be as expedient as can be required
considering the potential need to upgrade or replace monitoring
systems. The EPA solicits comment on whether 3 years is an appropriate
amount of time for EGUs to upgrade or replace monitoring systems, and
whether quarterly stack testing should continue to apply for EGUs that
have a binding commitment to permanently cease operations in the near
term. Additionally, the EPA proposes to remove fPM and the total and
individual non-Hg HAP metals from the LEE program no later than 3 years
after the promulgation date to align with the proposed compliance
method of PM CEMS. Lastly, the EPA is proposing to remove the
alternative work practice standard in paragraph (2) of the definition
of ``startup.'' The EPA proposes that affected sources must utilize
paragraph (1) of the definition of ``startup'' as specified in 40 CFR
part 63, subpart UUUUU, no later than 180 days after the effective
date.

VI. Summary of Cost, Environmental, and Economic Impacts

    In accordance with E.O. 12866 and 13563, the guidelines of OMB
Circular A-4, and EPA's Guidelines for Preparing Economic Analyses,\56\
the EPA prepared an RIA for this proposal. The RIA analyzes the
benefits and costs associated with the projected emissions reductions
under the proposed requirements, a less stringent set of requirements,
and a more stringent set of requirements to inform the EPA and the
public about these projected impacts.
---------------------------------------------------------------------------

    \56\ U.S. EPA (2014). Guidelines for Preparing Economic
Analyses. U.S. EPA. Washington, DC, U.S. Environmental Protection
Agency, Office of Policy, National Center for Environmental
Economics.
---------------------------------------------------------------------------

    We start this section of the preamble describing how the RIA for
this proposed rule structured the proposed and less and more stringent
regulatory options in the RIA. The proposed regulatory option in the
RIA includes the proposed revision to the fPM standard to 0.010 lb/
MMBtu, in which fPM is a surrogate for non-Hg metal HAP, the proposed
revision to the Hg standard for lignite-fired EGUs to 1.2 lb/TBtu, the
proposal to require PM CEMS to demonstrate compliance, and the removal
of the startup definition number two. The more stringent regulatory
option examined in the RIA tightens the proposed revision to the fPM
standard to 0.006 lb/MMBtu. The other three proposed amendments are not
changed in the more stringent regulatory option examined in the RIA.
Finally, the less stringent regulatory option examined in the RIA
assumed the fPM and Hg limits remain unchanged and examines just the
proposed PM CEMS requirement and removal of startup definition number
two.

A. What are the affected sources?

    The EPA estimates that there are 302 coal- and 56 oil-fired EGUs
that will be subject to the MATS rule by the compliance date.

B. What are the air quality impacts?

    The EPA estimated emissions reductions under the proposed rule for
the years 2028, 2030, and 2035 based upon IPM projections. The EPA also
used IPM to estimate emissions reductions for the more stringent
regulatory option examined in the RIA. The less stringent regulatory
option presented in the RIA has no quantified emissions reductions
associated with the proposed requirements for PM CEMS and the removal
of startup definition number two that constitute the less stringent
regulatory option presented in the RIA.
    The emissions reduction estimates presented in the RIA include
reductions in pollutants directly targeted by this rule, such as Hg,
and changes in other pollutants emitted from the power sector as a
result of the compliance actions projected under this proposed rule.
Table 10 presents the projected emissions reductions under the proposed
rule.

       Table 10--Projected EGU Emissions in the Baseline and Under the Proposed Rule: 2028, 2030, and 2035
----------------------------------------------------------------------------------------------------------------
                                                                               Emissions reductions
                                                                 -----------------------------------------------
                              Year                                                Less stringent  More stringent
                                                                   Proposed rule    regulatory      regulatory
                                                                                option          option
----------------------------------------------------------------------------------------------------------------
                                                    Hg (lbs.)
----------------------------------------------------------------------------------------------------------------
2028............................................................            62.0             0.0           208.0
2030............................................................            67.0             0.0           169.0
2035............................................................            82.0             0.0           168.0
----------------------------------------------------------------------------------------------------------------

                                               PM (thousand tons)
----------------------------------------------------------------------------------------------------------------
2028............................................................             0.4             0.0             2.6
2030............................................................             0.4             0.0             1.5
2035............................................................             0.8             0.0             1.3
----------------------------------------------------------------------------------------------------------------
                                               SO (thousand tons)
----------------------------------------------------------------------------------------------------------------
2028............................................................             0.9             0.0            11.6
2030............................................................             0.5             0.0             0.3
2035............................................................             1.5             0.0             8.8
----------------------------------------------------------------------------------------------------------------
                                         Ozone-season NO (thousand tons)
----------------------------------------------------------------------------------------------------------------
2028............................................................             0.2             0.0             7.2
2030............................................................             0.4             0.0             5.1
2035............................................................             3.2             0.0             5.6
----------------------------------------------------------------------------------------------------------------
                                            Annual NO (thousand tons)
----------------------------------------------------------------------------------------------------------------
2028............................................................             0.4             0.0            18.1
2030............................................................             0.8             0.0             9.5
2035............................................................             3.4             0.0             8.7
----------------------------------------------------------------------------------------------------------------
                                               HCl (thousand tons)
----------------------------------------------------------------------------------------------------------------
2028............................................................             0.0             0.0             0.2
2030............................................................             0.0             0.0             0.1
2035............................................................             0.0             0.0             0.1
----------------------------------------------------------------------------------------------------------------
                                            CO (million metric tons)
----------------------------------------------------------------------------------------------------------------
2028............................................................             0.2             0.0            21.9
2030............................................................             0.8             0.0             8.7
2035............................................................             4.6             0.0             2.9
----------------------------------------------------------------------------------------------------------------

    Section 3 of the RIA presents a detailed discussion of the
emissions projections under the regulatory options as described in the
RIA. Section 3 also describes the compliance actions that are projected
to produce the emissions reductions in Table 10. Please see section
VI.E of this preamble and section 4 of the RIA for detailed discussions
of the projected health, welfare, and climate benefits of these
emissions reductions.

C. What are the cost impacts?

    The power industry's compliance costs are represented in this
analysis as the change in electric power generation costs between the
baseline and policy scenarios. In simple terms, these costs are an
estimate of the increased power industry expenditures required to
implement the proposed requirements. The compliance cost estimates were
developed with EPA's Power Sector Modeling Platform v6 using IPM, a
state-of-the-art, peer-reviewed dynamic, deterministic linear
programming model of the contiguous U.S. electric power sector. IPM
provides forecasts of least cost capacity expansion, electricity
dispatch, and emission control strategies while meeting electricity
demand and various environmental, transmission, dispatch, and
reliability constraints. IPM's least-cost dispatch solution is designed
to ensure generation resource adequacy, either by using existing
resources or through the construction of new resources. IPM addresses
reliable delivery of generation resources for the delivery of
electricity between the 78 IPM regions, based on current and planned
transmission capacity, by setting limits to the ability to transfer
power between regions using the bulk power transmission system. The
model includes state-of-the-art estimates of the cost and performance
of air pollution control technologies with respect to Hg and other HAP
controls.
    We estimate the present value (PV) of the projected compliance
costs over the 2028 to 2037 period, as well as estimate the equivalent
annual value (EAV) of the flow of the compliance costs over this
period. All dollars are in 2019 dollars. Consistent with Executive
Order 12866 guidance, we estimate the PV and EAV using 3 and 7 percent
discount rates. Table 11 presents the estimates of compliance costs
across the regulatory options examined in the RIA.

        Table 11--Projected Compliance Costs of the Proposed Rule, Less Stringent Alternative, and More Stringent Alternative, 2028 Through 2037
                                                         [Millions 2019$, discounted to 2023] a
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         3% Discount rate                                7% Discount rate
                                                         -----------------------------------------------------------------------------------------------
                                                             Proposed     Less stringent  More stringent     Proposed     Less stringent  More stringent
--------------------------------------------------------------------------------------------------------------------------------------------------------
Present Value (PV)......................................             330             -45           4,600             230             -31           3,400
Equivalent Annualized Value (EAV).......................              38            -5.2             540              33            -4.5             490
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Values have been rounded to two significant figures.

    The PV of the compliance costs for the proposal, discounted at the
3 percent rate, is estimated to be about $330 million, with an EAV of
about $38 million. At the 7 percent discount rate, the PV of the
compliance costs of the proposal is estimated to be about $230 million,
with an EAV of about $33 million. For a detailed description of these
compliance cost projections, please see section 3 of the RIA, which is
available in the docket for this action.

D. What are the economic impacts?

    This proposed action has energy market implications. The power
sector analysis supporting this action indicates that there are
important power sector impacts that are worth noting, although they are
small relative to recent market-driven changes in the sector and
compared to some other EPA air regulatory actions for EGUs.
    There are several small national changes in energy prices projected
to result from the proposed revisions to the MATS rule. Retail
electricity prices are projected to increase in the contiguous U.S. by
an average of less than 0.1 percent in 2028, 2030, and 2035. In 2035,
the delivered natural gas price is anticipated to increase by less than
0.1 percent in response to the proposed rule. There are several other
types of energy impacts associated with the proposed revisions to MATS.
Some coal-fired capacity, about 500 MW (less than 1 percent of
operational coal capacity), is projected to become uneconomic to
maintain by 2028. Coal production for use in the power sector is not
projected to change significantly by 2028.
    The short-term estimates for employment needed to design,
construct, and install the control equipment in the 3-year period
before the compliance date are also provided using an approach that
estimates employment impacts for the environmental protection sector
based on projected changes from IPM on the number and scale of
pollution controls and labor intensities in relevant sectors. Finally,
some of the other types of employment impacts that will be ongoing are
estimated using IPM outputs and labor intensities, as reported in
section 5 of the RIA.

E. What are the benefits?

    Pursuant to E.O. 12866, the RIA for this action analyzes the
benefits associated with the projected emissions reductions under this
proposal to inform the EPA and the public about these projected
impacts. This proposed rule is projected to reduce emissions of Hg and
non-Hg metal HAP, PM2.5, SO2, NOX, and
CO2 nationwide. The potential impacts of these emissions
reductions are discussed in detail in section 4 of the RIA.
    The projected reductions in Hg emissions should reduce the
bioconcentration of methylmercury in fish in nearby waterbodies.
Subsistence fishing is associated with vulnerable populations,
including minorities and those of low socioeconomic status.
Methylmercury exposure to subsistence fishers from lignite-fired units
is below the current reference dose (RfD) for methylmercury
neurodevelopmental toxicity. The EPA considers exposures at or below
the RfD are unlikely to be associated with appreciable risk of
deleterious effects across the population. However, no RfD defines an
exposure level corresponding to zero risk; moreover, the RfD does not
represent a bright line above which individuals are at risk of adverse
effects. In addition, there was no evidence of a threshold for
methylmercury-related neurotoxicity within the range of exposures in
the Faroe Islands study which served as the primary basis for the
RfD.\57\ Reductions in Hg emissions from lignite-fired facilities
should further reduce exposure to methylmercury for subsistence fisher
sub-populations located in the vicinity of these facilities. The
projected reductions in non-Hg metal HAP may lead to reduced exposure
to carcinogenic metal HAP for residential populations near these
facilities, which should help the EPA maintain an ample margin of
safety. Furthermore, there is the potential for reductions in Hg and
non-Hg HAP emissions to enhance ecosystem services and improve
ecological outcomes, both of which can have positive economic effects
although it is difficult to estimate these benefits and consequently
they have not been included in the set of quantified benefits.
---------------------------------------------------------------------------

    \57\ U.S. EPA. 2001. IRIS Summary for Methylmercury. U.S.
Environmental Protection Agency, Washington, DC. (USEPA, 2001).
---------------------------------------------------------------------------

    The proposed rule is expected to reduce emissions of direct
PM2.5, NOX, and SO2 nationally
throughout the year. Because NOX and SO2 are also
precursors to secondary formation of ambient PM2.5, reducing
these emissions would reduce human exposure to ambient PM2.5
throughout the year and would reduce the incidence of PM2.5-
attributable health effects. This proposed rule is also expected to
reduce ozone-season NOX emissions nationally. In the
presence of sunlight, NOX and volatile organic compounds
(VOCs) can undergo a chemical reaction in the atmosphere to form ozone.
Reducing NOX emissions in most locations reduces human
exposure to ozone and the incidence of ozone-related health effects,
though the degree to which ozone is reduced will depend in part on
local concentration levels of VOCs.
    The health effect endpoints, effect estimates, benefit unit-values,
and how they were selected, are described in the TSD titled Estimating
PM2.5- and Ozone-Attributable Health Benefits, which is referenced in
the RIA for this action. Our approach for updating the endpoints and to
identify suitable epidemiologic studies, baseline incidence rates,
population demographics, and valuation estimates is summarized in
section 4 of the RIA. This proposed rule is projected to reduce
PM2.5 and ozone concentrations, producing a projected PV of
monetized health benefits of about $1.9 billion, with an EAV of about
$220 million discounted at 3 percent.
    Because of projected changes in dispatch under the proposed
requirements, the proposed rule is also projected to reduce
CO2 emissions. The EPA estimated the climate benefits from

this proposed rule using estimates of the social cost of greenhouse
gases (SC-GHG), specifically the social cost of carbon (SC-
CO2). The SC-CO2 is the monetary value of the net
harm to society associated with a marginal increase in CO2
emissions in a given year, or the benefit of avoiding that increase. In
principle, SC-CO2 includes the value of all climate change
impacts (both negative and positive), including (but not limited to)
changes in net agricultural productivity, human health effects,
property damage from increased flood risk natural disasters, disruption
of energy systems, risk of conflict, environmental migration, and the
value of ecosystem services. The SC-CO2, therefore, reflects
the societal value of reducing emissions of the gas in question by one
metric ton and is the theoretically appropriate value to use in
conducting benefit-cost analyses of policies that affect CO2
emissions. In practice, data and modeling limitations naturally
restrain the ability of SC-CO2 estimates to include all the
important physical, ecological, and economic impacts of climate change,
such that the estimates are a partial accounting of climate change
impacts and will therefore, tend to be underestimates of the marginal
benefits of abatement. The EPA and other Federal agencies began
regularly incorporating SC-GHG estimates in their benefit-cost analyses
conducted under E.O. 12866 \58\ since 2008, following a Ninth Circuit
Court of Appeals remand of a rule for failing to monetize the benefits
of reducing CO2 emissions in a rulemaking process.
---------------------------------------------------------------------------

    \58\ Benefit-cost analyses have been an integral part of
executive branch rulemaking for decades. Presidents since the 1970s
have issued executive orders requiring agencies to conduct analysis
of the economic consequences of regulations as part of the
rulemaking development process. E.O. 12866, released in 1993 and
still in effect today, requires that for all economically
significant regulatory actions, an agency provide an assessment of
the potential costs and benefits of the regulatory action, and that
this assessment include a quantification of benefits and costs to
the extent feasible.
---------------------------------------------------------------------------

    We estimate the global social benefits of CO2 emission
reductions expected from the proposed rule using the SC-GHG estimates
presented in the February 2021 TSD: Social Cost of Carbon, Methane, and
Nitrous Oxide Interim Estimates under E.O. 13990. These SC-GHG
estimates are interim values developed under E.O. 13990 for use in
benefit-cost analyses until updated estimates of the impacts of climate
change can be developed based on the best available climate science and
economics. We have evaluated the SC-GHG estimates in the TSD and have
determined that these estimates are appropriate for use in estimating
the global social benefits of CO2 emission reductions
expected from this proposed rule. After considering the TSD, and the
issues and studies discussed therein, the EPA finds that these
estimates, while likely an underestimate, are the best currently
available SC-GHG estimates. These SC-GHG estimates were developed over
many years using a transparent process, peer-reviewed methodologies,
the best science available at the time of that process, and with input
from the public. As discussed in section 4.4 of the RIA, these interim
SC-CO2 estimates have a number of limitations, including
that the models used to produce them do not include all of the
important physical, ecological, and economic impacts of climate change
recognized in the climate-change literature and that several modeling
input assumptions are outdated. As discussed in the February 2021 TSD,
the Interagency Working Group on the Social Cost of Greenhouse Gases
(IWG) finds that, taken together, the limitations suggest that these
SC-CO2 estimates likely underestimate the damages from
CO2 emissions. The IWG is currently working on a
comprehensive update of the SC-GHG estimates (under E.O. 13990) taking
into consideration recommendations from the National Academies of
Sciences, Engineering and Medicine, recent scientific literature,
public comments received on the February 2021 TSD and other input from
experts and diverse stakeholder groups. The EPA is participating in the
IWG's work. In addition, while that process continues, the EPA is
continuously reviewing developments in the scientific literature on the
SC-GHG, including more robust methodologies for estimating damages from
emissions, and looking for opportunities to further improve SC-GHG
estimation going forward. Most recently, the EPA has developed a draft
updated SC-GHG methodology within a sensitivity analysis in the RIA of
the EPA's November 2022 supplemental proposal for oil and gas standards
that is currently undergoing external peer review and a public comment
process. See section 4.4 of the RIA for more discussion of this effort.
    Table 12 presents the estimated PV and EAV of the projected health
and climate benefits across the regulatory options examined in the RIA
in 2019 dollars discounted to 2023. The table includes benefit
estimates for the less and more stringent regulatory options examined
in the RIA for this proposal.

            Table 12--Projected Benefits of the Proposed Rule, Less Stringent Alternative, and More Stringent Alternative, 2028 Through 2037
                                                         [Millions 2019$, discounted to 2023] a
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Present value (PV)
                                                         -----------------------------------------------------------------------------------------------
                                                                         3% Discount rate                              7% Discount rate \d\
                                                         -----------------------------------------------------------------------------------------------
                                                             Proposed     Less stringent  More stringent     Proposed     Less stringent  More stringent
--------------------------------------------------------------------------------------------------------------------------------------------------------
Health Benefits \c\.....................................           1,900             0.0          11,000           1,200             0.0           7,100
Climate Benefits \d\....................................           1,400             0.0           3,200       \d\ 1,400         \d\ 0.0       \d\ 3,200
                                                         -----------------------------------------------------------------------------------------------
    Benefits \e\........................................           3,300             0.0          14,000           2,600             0.0          10,000
--------------------------------------------------------------------------------------------------------------------------------------------------------

                                                                                Equal annualized value (EAV) \b\
                                                         -----------------------------------------------------------------------------------------------
                                                                         3% Discount rate                              7% Discount rate \d\
                                                         -----------------------------------------------------------------------------------------------
                                                             Proposed     Less stringent  More stringent     Proposed     Less stringent  More stringent
--------------------------------------------------------------------------------------------------------------------------------------------------------
Health Benefits \c\.....................................             220             0.0           1,300             170             0.0           1,000
Climate Benefits \d\....................................             170             0.0             380         \d\ 170         \d\ 0.0         \d\ 380
                                                         -----------------------------------------------------------------------------------------------

    Benefits \e\........................................             390             0.0           1,700             330             0.0           1,400
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Values have been rounded to two significant figures. Rows may not appear to sum correctly due to rounding.
\b\ The EAV of benefits are calculated over the 10-year period from 2028 to 2037.
\c\ The projected monetized benefits include those related to public health associated with reductions in PM2.5 and ozone concentrations. The projected
  health benefits are associated with several point estimates and are presented at real discount rates of 3 and 7 percent.
\d\ Climate benefits are based on reductions in CO2 emissions and are calculated using four different estimates of the social cost of carbon dioxide (SC-
  CO2): model average at 2.5 percent, 3 percent, and 5 percent discount rates; 95th percentile at 3 percent discount rate. For the presentational
  purposes of this table, we show the climate benefits associated with the average SC-CO2 at a 3 percent discount rate, but the Agency does not have a
  single central SC-CO2 point estimate. Climate benefits in this table are discounted using a 3 percent discount rate to obtain the PV and EAV estimates
  in the table. We emphasize the importance and value of considering the benefits calculated using all four SC-CO2 estimates. Section 4.4 of the RIA
  presents estimates of the projected climate benefits of this proposal using all four rates. We note that consideration of climate benefits calculated
  using discount rates below 3 percent, including 2 percent and lower, is warranted when discounting intergenerational impacts.
\e\ Several categories of benefits remain unmonetized and are thus not directly reflected in the quantified benefit estimates in the table. Non-
  monetized benefits include benefits from reductions in Hg and non-Hg metal HAP emissions and from the increased transparency and accelerated
  identification of anomalous emission anticipated from requiring CEMS.

    This proposed rule is projected to reduce PM2.5 and
ozone concentrations, producing a projected PV of monetized health
benefits of about $1.9 billion, with an EAV of about $220 million
discounted at 3 percent. The projected PV of monetized climate benefits
of the proposal are estimated to be about $1.4 billion, with an EAV of
about $170 million using the SC-CO2 discounted at 3 percent.
Thus, this proposed rule would generate a PV of monetized benefits of
$3.3 billion, with an EAV of $390 million discounted at a 3 percent
rate.
    At a 7 percent discount rate, this proposed rule is expected to
generate projected PV of monetized health benefits of $1.2 billion,
with an EAV of about $170 million discounted at 7 percent. Climate
benefits remain discounted at 3 percent in this benefits analysis and
are estimated to be about $1.4 billion, with an EAV of about $170
million using the SC-CO2. Thus, this proposed rule would
generate a PV of monetized benefits of $2.6 billion, with an EAV of
$330 million discounted at a 7 percent rate. The potential benefits
from reducing Hg and non-Hg metal HAP were not monetized and are
therefore not directly reflected in the monetized benefit-cost
estimates associated with this proposal. Potential benefits from the
increased transparency and accelerated identification of anomalous
emission anticipated from requiring CEMS were also not monetized in
this analysis and are therefore also not directly reflected in the
monetized benefit-cost comparisons. We nonetheless consider these
impacts in our evaluation of the net benefits of the rule and find, if
we were able to monetize these beneficial impacts, the proposal would
have greater net benefits than shown in Table 12.

F. What analysis of environmental justice did we conduct?

    Executive Order 12898 directs the EPA to identify the populations
of concern who are most likely to experience unequal burdens from
environmental harms; specifically, minority populations, low-income
populations, and Indigenous peoples.\59\ Additionally, Executive Order
13985 is intended to advance racial equity and support underserved
communities through federal government actions.\60\ The EPA defines
environmental justice (EJ) as the fair treatment and meaningful
involvement of all people regardless of race, color, national origin,
or income, with respect to the development, implementation, and
enforcement of environmental laws, regulations, and policies. The EPA
further defines the term fair treatment to mean that ``no group of
people should bear a disproportionate burden of environmental harms and
risks, including those resulting from the negative environmental
consequences of industrial, governmental, and commercial operations or
programs and policies.'' \61\ In recognizing that minority and low-
income populations often bear an unequal burden of environmental harms
and risks, the EPA continues to consider ways of protecting them from
adverse public health and environmental effects of air pollution.
---------------------------------------------------------------------------

    \59\ 59 FR 7629, February 16, 1994.
    \60\ 86 FR 7009, January 20, 2021.
    \61\ https://www.epa.gov/environmentaljustice.
---------------------------------------------------------------------------

    The EPA's EJ technical guidance \62\ states that ``[t]he analysis
of potential EJ concerns for regulatory actions should address three
questions:
---------------------------------------------------------------------------

    \62\ U.S. Environmental Protection Agency (EPA), 2015. Guidance
on Considering Environmental Justice During the Development of
Regulatory Actions.
---------------------------------------------------------------------------

    1. Are there potential EJ concerns associated with environmental
stressors affected by the regulatory action for population groups of
concern in the baseline?
    2. Are there potential EJ concerns associated with environmental
stressors affected by the regulatory action for population groups of
concern for the regulatory option(s) under consideration?
    3. For the regulatory option(s) under consideration, are potential
EJ concerns created or mitigated compared to the baseline?''
    To address these questions in the EPA's first quantitative EJ
analysis in the context of a MATS rule, the EPA developed a unique
analytical approach that considers the purpose and specifics of the
proposed rulemaking, as well as the nature of known and potential
disproportionate and adverse exposures and impacts. However, due to
data limitations, it is possible that our analysis failed to identify
disparities that may exist, such as potential EJ characteristics (e.g.,
residence of historically red lined areas), environmental impacts
(e.g., other ozone metrics), and more granular spatial resolutions
(e.g., neighborhood scale) that were not evaluated. Also due to data
and resource limitations, we discuss HAP and climate EJ impacts of this
action qualitatively (sections 6.3 and 6.6 of the RIA).
    For this proposed rule, we employ two types of analysis to respond
to the previous three questions: proximity analyses and exposure
analyses. Both types of analyses can inform whether there are potential
EJ concerns for population groups of concern in the

baseline (question 1).\63\ In contrast, only the exposure analyses,
which are based on future air quality modeling, can inform whether
there will be potential EJ concerns after implementation of the
regulatory options under consideration (question 2) and whether
potential EJ concerns will be created or mitigated compared to the
baseline (question 3). While the exposure analysis can respond to all
three questions, several caveats should be noted. For example, the air
pollutant exposure metrics are limited to those used in the benefits
assessment. For ozone, that is the maximum daily 8-hour average,
averaged across the April through September warm season (AS-MO3) and
for PM2.5 that is the annual average. This ozone metric
likely smooths potential daily ozone gradients and is not directly
relatable to the NAAQS, whereas the PM2.5 metric is more
similar to the long term PM2.5 standard. The air quality
modeling estimates are also based on state level emission data paired
with facility-level baseline emissions and provided at a resolution of
12 km\2\. Additionally, here we focus on air quality changes due to
this proposed rulemaking and infer post-policy exposure burden impacts.
---------------------------------------------------------------------------

    \63\ The baseline for proximity analyses is current population
information, whereas the baseline for ozone exposure analyses are
the future years in which the regulatory options will be implemented
(e.g., 2023 and 2026).
---------------------------------------------------------------------------

    Exposure analysis results are provided in two formats: aggregated
and distributional. The aggregated results provide an overview of
potential ozone exposure differences across populations at the
national- and state-levels, while the distributional results show
detailed information about ozone concentration changes experienced by
everyone within each population.
    In section 6 of the RIA we utilize the two types of analysis to
address the three EJ questions by quantitatively evaluating: (1) the
proximity of affected facilities to populations of potential EJ concern
(section 6.4); and (2) the potential for disproportionate ozone and
PM2.5 concentrations in the baseline and concentration
changes after rule implementation across different demographic groups
(section 6.5). Each of these analyses depends on mutually exclusive
assumptions, was performed to answer separate questions, and is
associated with unique limitations and uncertainties.
    Baseline demographic proximity analyses can be relevant for
identifying populations that may be exposed to local environmental
stressors, such as local NO2 and SO2 emitted from
affected sources in this proposed rule, traffic, or noise. The baseline
analysis indicates that on average the populations living within 10 km
of coal plants potentially subject to the proposed or alternate
filterable PM standards have a higher percentage of people living below
two times the poverty level than the national average. In addition, on
average the percentage of the Native American population living within
10 km of lignite plants potentially subject to proposed Hg standard is
higher than the national average. Relating these results to EJ question
1, we conclude that there may be potential EJ concerns associated with
directly emitted pollutants that are affected by the regulatory action
(e.g., SO2) for certain population groups of concern in the
baseline (question 1). However, as proximity to affected facilities
does not capture variation in baseline exposure across communities, nor
does it indicate that any exposures or impacts will occur, these
results should not be interpreted as a direct measure of exposure or
impact.
    As HAP exposure results generated as part of the 2020 Residual Risk
analysis were below both the presumptive acceptable cancer risk
threshold and noncancer health benchmarks and this proposed regulation
should further reduce exposure to HAP, there are no `disproportionate
and adverse effects' of potential EJ concern. Therefore, we did not
perform a quantitative EJ assessment of HAP risk.
    This proposed rule is also expected to reduce emissions of direct
PM2.5, NOX, and SO2 nationally
throughout the year. Because NOX and SO2 are also
precursors to secondary formation of ambient PM2.5 and
NOX is a precursor to ozone formation, reducing these
emissions would impact human exposure. Quantitative ozone and
PM2.5 exposure analyses can provide insight into all three
EJ questions, so they are performed to evaluate potential
disproportionate impacts of this rulemaking. Even though both the
proximity and exposure analyses can potentially improve understanding
of baseline EJ concerns (question 1), the two should not be directly
compared. This is because the demographic proximity analysis does not
include air quality information and is based on current, not future,
population information.
    The baseline analysis of ozone and PM2.5 concentration
burden responds to question 1 from EPA's EJ Technical Guidance document
more directly than the proximity analyses, as it evaluates a form of
the environmental stressor targeted by the regulatory action. Baseline
ozone and PM2.5 analyses show that certain populations, such
as Hispanics, Asians, those linguistically isolated, those less
educated, and children may experience somewhat higher ozone and
PM2.5 concentrations compared to the national average.
Therefore, also in response to question 1, there likely are potential
EJ concerns associated with ozone and PM2.5 exposures
affected by the regulatory action for population groups of concern in
the baseline. However, these baseline exposure results have not been
fully explored and additional analyses are likely needed to understand
potential implications. Due to the small magnitude of the exposure
changes across population demographics associated with the rulemaking
relative to the magnitude of the baseline disparities, we infer that
post-policy EJ ozone and PM2.5 concentration burdens are
likely to remain after implementation of the regulatory action or
alternative under consideration (question 2).
    Question 3 asks whether potential EJ concerns will be created or
mitigated as compared to the baseline. Due to the very small magnitude
of differences across demographic population post-policy ozone and
PM2.5 exposure impacts, we do not find evidence that
potential EJ concerns related to ozone and PM2.5
concentrations will be created or mitigated as compared to the
baseline.\64\
---------------------------------------------------------------------------

    \64\ Please note, exposure results should not be extrapolated to
other air pollutant. Detailed EJ analytical results can be found in
Section 6 of the RIA.
---------------------------------------------------------------------------

    Prior to this proposed rule, the EPA initiated a public outreach
effort to gather input from stakeholder groups likely to be interested
in this proposed rule. Specifically, the EPA presented on a National EJ
call on September 20, 2022, to share information about the proposed
rule and solicit feedback about potential EJ considerations. The
webinar was attended by individuals representing state governments,
federally recognized tribes, environmental non-governmental
organizations, higher education institutions, industry, and the
EPA.\65\
---------------------------------------------------------------------------

    \65\ This does not constitute the EPA's tribal consultation
under E.O. 13175, which is described in section VIII.F of this
proposed rule.

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

    In addition to the engagement conducted prior to this proposed
rule, the EPA is providing the public, including those communities
disproportionately impacted by the burdens of pollution, opportunities
to engage in the EPA's public comment period for this proposed rule,
including by hosting a public hearing. This public hearing will occur
according to the schedule identified in the SUPPLEMENTARY INFORMATION
under the heading entitled Participation in virtual public hearing of
this proposed rule.

VII. Request for Comments

    We solicit comments on this proposed action. In addition to general
comments on this proposed action, we are also interested in additional
data that may improve the analyses. We are specifically interested in
receiving any information regarding developments in practices,
processes, and control technologies that reduce HAP emissions. We are
also interested in comments on any reliance interests stakeholders may
have that would be affected by this proposed action.

VIII. Statutory and Executive Order Reviews

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

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

    This action was submitted to the OMB for review under section
3(f)(1) of Executive Order 12866. Any changes made in response to
recommendations received as part of review under Executive Order 12866
have been documented in the docket. The EPA prepared an analysis of the
potential costs and benefits associated with this action. This
analysis, ``Regulatory Impact Analysis for the Proposed National
Emission Standards for Hazardous Air Pollutants: Coal- and Oil-Fired
Electric Utility Steam Generating Units Review of the Residual Risk and
Technology Review'' (Ref. EPA-452/R-23-002), is available in the docket
and is briefly summarized in section VI of this preamble and here.
    Table 13 presents the estimated PV and EAV of the projected health
benefits, climate benefits, compliance costs, and net benefits of the
proposed rule in 2019 dollars discounted to 2023. The estimated
monetized net benefits are the projected monetized benefits minus the
projected monetized costs of the proposed rule. Table 13 also presents
results for the less stringent and more stringent alternatives that are
examined in the RIA for this proposal.
    Under E.O. 12866, the EPA is directed to consider all of the costs
and benefits of its actions, not just those that stem from the
regulated pollutant. Accordingly, the projected monetized benefits of
the proposal include health benefits associated with projected
reductions in fine particulate matter (PM2.5) and ozone
concentration. The projected monetized benefits also include climate
benefits due to reductions in CO2 emissions. The projected
health benefits are associated with several point estimates and are
presented at real discount rates of 3 and 7 percent. The projected
climate benefits in this table are based on estimates of the SC-
CO2 at a 3 percent discount rate and are discounted using a
3 percent discount rate to obtain the PV and EAV estimates in the
table. The power industry's compliance costs are represented in this
analysis as the change in electric power generation costs between the
baseline and policy scenarios. In simple terms, these costs are an
estimate of the increased power industry expenditures required to
implement the proposed requirements and represent the EPA's best
estimate of the social cost of the proposed rulemaking.

     Table 13--Projected Monetized Benefits, Compliance Costs, and Net Benefits of the Proposed Rule, Less Stringent Alternative, and More Stringent
                                                             Alternative, 2028 Through 2037
                                                        [Millions 2019$, discounted to 2023] \a\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Present value (PV)
                                                         -----------------------------------------------------------------------------------------------
                                                                         3% Discount rate                              7% Discount rate \d\
                                                         -----------------------------------------------------------------------------------------------
                                                             Proposed     Less stringent  More stringent     Proposed     Less stringent  More stringent
--------------------------------------------------------------------------------------------------------------------------------------------------------
Health Benefits \c\.....................................           1,900             0.0          11,000           1,200             0.0           7,100
Climate Benefits \d\....................................           1,400             0.0           3,200       \d\ 1,400         \d\ 0.0       \d\ 3,200
Compliance Costs........................................             330             -45           4,600             230             -31           3,400
                                                         -----------------------------------------------------------------------------------------------
    Net Benefits \e\....................................           3,000              45           9,800           2,400              31           6,900
--------------------------------------------------------------------------------------------------------------------------------------------------------

                                                                                Equal Annualized Value (EAV) \b\
                                                         -----------------------------------------------------------------------------------------------
                                                                         3% Discount rate                              7% Discount rate \d\
                                                         -----------------------------------------------------------------------------------------------
                                                             Proposed     Less stringent  More stringent     Proposed     Less stringent  More stringent
--------------------------------------------------------------------------------------------------------------------------------------------------------
Health Benefits \c\.....................................             220             0.0           1,300             170             0.0           1,000
Climate Benefits \d\....................................             170             0.0             380         \d\ 170         \d\ 0.0         \d\ 380
Compliance Costs........................................              38            -5.2             540              33            -4.5             490
                                                         -----------------------------------------------------------------------------------------------
    Net Benefits \e\....................................             350             5.2           1,100             300             4.5             900
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Values have been rounded to two significant figures. Rows may not appear to sum correctly due to rounding.
\b\ The EAV of costs and benefits are calculated over the 10-year period from 2028 to 2037.
\c\ The projected monetized benefits include those related to public health associated with reductions in PM2.5 and ozone concentrations. The projected
  health benefits are associated with several point estimates and are presented at real discount rates of 3 and 7 percent.

\d\ Climate benefits are based on reductions in CO2 emissions and are calculated using four different estimates of the social cost of carbon dioxide (SC-
  CO2): model average at 2.5 percent, 3 percent, and 5 percent discount rates; 95th percentile at 3 percent discount rate. For the presentational
  purposes of this table, we show the climate benefits associated with the average SC-CO2 at a 3 percent discount rate, but the Agency does not have a
  single central SC-CO2 point estimate. Climate benefits in this table are discounted using a 3 percent discount rate to obtain the PV and EAV estimates
  in the table. We emphasize the importance and value of considering the benefits calculated using all four SC-CO2 estimates. Section 4.4 of the RIA
  presents estimates of the projected climate benefits of this proposal using all four rates. We note that consideration of climate benefits calculated
  using discount rates below 3 percent, including 2 percent and lower, is warranted when discounting intergenerational impacts.
\e\ Several categories of benefits remain unmonetized and are thus not directly reflected in the quantified benefit estimates in the table. Non-
  monetized benefits include benefits from reductions in Hg and non-Hg metal HAP emissions and from the increased transparency and accelerated
  identification of anomalous emission anticipated from requiring CEMS.

    As shown in Table 13, this proposed rule is projected to reduce
PM2.5 and ozone concentrations, producing a projected PV of
monetized health benefits of about $1.9 billion, with an EAV of about
$220 million discounted at 3 percent. The proposed rule is also
projected to reduce greenhouse gas emissions in the form of
CO2, producing a projected PV of monetized climate benefits
of about $1.4 billion, with an EAV of about $170 million using the SC-
CO2 discounted at 3 percent. The PV of the projected
compliance costs are $330 million, with an EAV of about $38 million
discounted at 3 percent. Combining the projected benefits with the
projected compliance costs yields a net benefit PV estimate of $3
billion and EAV of $350 million.
    At a 7 percent discount rate, this proposed rule is expected to
generate projected PV of monetized health benefits of $1.2 billion,
with an EAV of about $170 million. Climate benefits remain discounted
at 3 percent in this net benefits analysis. Thus, this proposed rule
would generate a PV of monetized benefits of $2.6 billion, with an EAV
of $340 million discounted at a 7 percent rate. The PV of the projected
compliance costs are $230 million, with an EAV of $33 million
discounted at 7 percent. Combining the projected benefits with the
projected compliance costs yields a net benefit PV estimate of $2.4
billion and an EAV of $300 million.
    The potential benefits from reducing Hg and non-Hg metal HAP were
not monetized and are therefore not directly reflected in the monetized
benefit-cost estimates associated with this proposal. Potential
benefits from the increased transparency and accelerated identification
of anomalous emission anticipated from requiring CEMS requiring were
also not monetized in this analysis and are therefore also not directly
reflected in the monetized benefit-cost comparisons. We nonetheless
consider these impacts in our evaluation of the net benefits of the
rule and find, if we were able to monetize these beneficial impacts,
the proposal would have greater net benefits than shown in Table 13.

B. Paperwork Reduction Act (PRA)

    OMB has previously approved the information collection activities
contained in the existing regulations and has assigned OMB control
number 2060-0567. The information collection activities in this
proposed rule, which are a revision to the existing approved
information collection activities, have been submitted for approval to
the OMB under the PRA. The ICR document that the EPA prepared has been
assigned EPA ICR number 2137-12. You can find a copy of the ICR in the
docket for this rule, and it is briefly summarized here.
    The information collection activities in this proposed rule include
continuous emission monitoring, performance testing, notifications and
periodic reports, recording information, monitoring and the maintenance
of records. The information generated by these activities will be used
by the EPA to ensure that affected facilities comply with the emission
limits and other requirements. Records and reports are necessary to
enable delegated authorities to identify affected facilities that may
not be in compliance with the requirements. Based on reported
information, delegated authorities will decide which units and what
records or processes should be inspected. The recordkeeping
requirements require only the specific information needed to determine
compliance. These recordkeeping and reporting requirements are
specifically authorized by CAA section 114 (42 U.S.C. 7414).
    Respondents/affected entities: The respondents are owners or
operators of coal- and oil-fired EGUs. The NAICS codes for the coal-
and oil-fired EGU industry are 221112, 221122, and 921150.
    Respondent's obligation to respond: Mandatory per 42 U.S.C. 7414 et
seq.
    Estimated number of respondents: 187 per year.
    Frequency of response: The frequency of responses varies depending
on the burden item. Responses include daily calibrations, quarterly
inspections, and semiannual compliance reports.
    Total estimated burden: 443,000 hours (per year). Burden is defined
at 5 CFR 1320.3(b).
    Total estimated cost: $100,100,000 (per year), includes $49,600,000
annualized capital or operation & maintenance costs.
    An agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for the
EPA's regulations in 40 CFR are listed in 40 CFR part 9.
    Submit your comments on the EPA's need for this information, the
accuracy of the provided burden estimates and any suggested methods for
minimizing respondent burden to the EPA using the docket identified at
the beginning of this rule. The EPA will respond to any ICR-related
comments in the final rule. You may also send your ICR-related comments
to OMB's Office of Information and Regulatory Affairs using the
interface at https://www.reginfo.gov/public/do/PRAMain. Find this
particular information collection by selecting ``Currently under
Review--Open for Public Comments'' or by using the search function. OMB
must receive comments no later than June 23, 2023.

C. Regulatory Flexibility Act (RFA)

    The EPA certifies that this proposed action will not have a
significant economic impact on a substantial number of small entities
under the Regulatory Flexibility Act (RFA). The EPA chose to examine
the projected impacts of a more stringent regulatory option than
proposed on small entities in order to present a scenario of ``maximum
cost impact.'' As projected cost impacts of the proposed rule is
dominated by cost impacts of the more stringent alternative also
examined in the RIA, a no SISNOSE conclusion for the more stringent
option can be extended to the proposed rule and less stringent option.
    In 2028, the EPA identified 26 potentially affected small entities
operating 41 units at 27 facilities, and of these 26, only two small
entities may experience compliance cost increases greater than 1
percent of revenue under the proposed rule, and three small entities
may experience such increases under the more stringent alternative.

Details of this analysis are presented in section 5 of the RIA, which
is in the public docket.

D. Unfunded Mandates Reform Act of 1995 (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. In light of the interest in this rule among
governmental entities, the EPA initiated consultation with governmental
entities. The EPA invited the following 10 national organizations
representing state and local elected officials to a virtual meeting on
September 22, 2022: (1) National Governors Association, (2) National
Conference of State Legislatures, (3) Council of State Governments, (4)
National League of Cities, (5) U.S. Conference of Mayors, (6) National
Association of Counties, (7) International City/County Management
Association, (8) National Association of Towns and Townships, (9)
County Executives of America, and (10) Environmental Council of States.
These 10 organizations representing elected state and local officials
have been identified by the EPA as the ``Big 10'' organizations
appropriate to contact for purpose of consultation with elected
officials. Also, the EPA invited air and utility professional groups
who may have state and local government members, such as the
Association of Air Pollution Control Agencies, National Association of
Clean Air Agencies, and others to participate in the meeting. The
purpose of the consultation was to provide general background on the
review of the MATS RTR, answer questions, and solicit input from state
and local governments. Subsequent to the September 22, 2022, meeting,
the EPA received a letter from the American Public Power Association
(APPA). The EPA opened a non-rulemaking docket for public input on the
EPA's efforts to reduce greenhouse gas emissions from new and existing
fossil fuel-fired EGUs. The APPA letter was submitted to the non-
rulemaking docket. See Docket ID No. EPA-HQ-OAR-2022-0723-0016. In that
letter, APPA stated that they were not able to identify any new cost-
effective technologies to reduce HAP emissions and that many of the
current technologies used are state-of-the-art controls that continue
to reduce HAP emissions. In addition, APPA stated there have been no
developments in the emission control practices or processes available
to control HAP emissions during startup and shutdown periods. Also,
APPA stated that they support the continuation of the 30-day rolling
average to assure compliance with MATS emission requirements to allow
for hourly variability caused by unit operation and load requirements,
including startup and shutdown events.

E. 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.
    The EPA believes, however, that this action may be of interest to
state and/or local governments. Consistent with the EPA's policy to
promote communication between the EPA and state and local governments,
the EPA consulted with representatives of state and local governments
in the process of developing the proposed amendments to permit them to
have meaningful and timely input into its development. The EPA's
consultation regarded planned actions for the review of the MATS RTR.
The EPA met with 10 national organizations representing state and local
elected officials to provide general background on the review of the
MATS RTR, answer questions, and solicit input from state and local
governments. The UMRA discussion in this preamble includes a
description of the consultation. In the spirit of E.O. 13132, and
consistent with EPA policy to promote communications between state and
local governments, the EPA specifically solicits comment on this
proposed action from state and local officials.

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

    This action does not have tribal implications as specified in
Executive Order 13175. The Executive order defines tribal implications
as ``actions that have substantial direct effects on one or more Indian
tribes, on the relationship between the Federal Government and Indian
tribes.'' The amendments proposed in this action would not have a
substantial direct effect on one or more tribes, change the
relationship between the Federal Government and tribes, or affect the
distribution of power and responsibilities between the Federal
Government and Indian tribes. Thus, Executive Order 13175 does not
apply to this action.
    Although this action does not have tribal implications as specified
in Executive Order 13175, the EPA consulted with tribal officials
during the development of this action. On September 1, 2022, the EPA
sent a letter to all federally recognized Indian tribes initiating
consultation to obtain input on this proposal. The EPA did not receive
any requests from consultation from Indian tribes. The EPA also
participated in the September 2022 National Tribal Air Association EPA
Air Policy Update Call to solicit input on this proposed action.

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

    This proposed rule is a ``[c]overed regulatory action'' under
Executive Order 13045 because it is a significant regulatory action as
described in section 3(f)(1) of Executive Order 12866, and the EPA
believes that, even though the residual risk assessment showed all
modeled exposures to HAP to be below thresholds for public health
concern, the rule should reduce HAP exposure by reducing emissions of
Hg and non-Hg HAP with the potential to reduce HAP exposure to
vulnerable populations including children. Accordingly, we have
evaluated the potential for environmental health or safety effects from
exposure to HAP on children. The results of this evaluation are
contained in the RIA and are available in the docket for this action.
The EPA believes that the PM2.5-related, ozone-related, and
CO2-related benefits projected under this proposed rule will
further improve children's health. Specifically, the PM2.5
and ozone EJ exposure analyses in section 6 of the RIA suggests that
nationally, children (ages 0-17) will experience at least as great a
reduction in annual PM2.5 and ozone exposures as adults
(ages 18-64) will experience in 2028, 2030 and 2035 under all
regulatory alternatives of this rulemaking.

H. 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. For 2028, the compliance year for the
proposed standards, the EPA projects a less than 0.1 percent change in
retail electricity prices on average across the contiguous U.S., a less
than 0.1 percent reduction in coal-fired electricity generation, and a
less than 0.1 percent increase in natural gas-fired electricity

generation. The EPA does not project a significant change in utility
power sector delivered natural gas prices in 2028. Details of the
projected energy effects are presented in section 3 of the RIA, which
is in the public docket.

I. National Technology Transfer and Advancement Act (NTTAA)

    This rulemaking does not involve technical standards.

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

    Executive Order 12898 (59 FR 7629, February 16, 1994) directs
federal agencies, to the greatest extent practicable and permitted by
law, to make EJ part of their mission by identifying and addressing, as
appropriate, disproportionately high and adverse human health or
environmental effects of their programs, policies, and activities on
minority populations (people of color and/or Indigenous peoples) and
low-income populations.
    HAP risks were below both the presumptive acceptable cancer risk
threshold and the RfD, and this proposed regulation will likely further
reduce exposure to HAP. As such, the EPA believes that this action does
not result in disproportionate and adverse effects on people of color,
low-income populations, and/or Indigenous peoples.
    The EPA believes that PM2.5 and ozone exposures that
exist prior to this action result in disproportionate and adverse human
health or environmental effects on people of color, low-income
populations and/or Indigenous peoples. Specifically, baseline
PM2.5 and ozone and exposure analyses show that certain
populations, such as Hispanics, Asians, those linguistically isolated,
those less educated, and children may experience disproportionately
higher ozone and PM2.5 exposures as compared to the national
average. The EPA believes that this action is not likely to change
existing disproportionate PM2.5 and ozone exposure impacts
on people of color, low-income populations and/or Indigenous peoples.
American Indians may also experience disproportionately higher ozone
concentrations than the reference group. We do not find evidence that
potential EJ concerns related to ozone or PM2.5 exposures
will be meaningfully exacerbated or mitigated in the regulatory
alternatives under consideration as compared to the baseline due to the
small magnitude of ozone and PM2.5 concentration changes
associated with this rule relative to baseline disparities and the very
small differences in the distributional analyses of post-policy ozone
and PM2.5 exposure impacts. Importantly, the action
described in this rule is expected to lower ozone and PM2.5
in certain areas, and thus mitigate some pre-existing health risks
across all populations evaluated.
    The documentation for these analyses is contained in section VI.F
of this this proposed rule and in section 6, Environmental Justice
Impacts of the RIA, which is in the public docket.

List of Subjects in 40 CFR Part 63

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

Michael S. Regan,
Administrator.
[FR Doc. 2023-07383 Filed 4-21-23; 8:45 am]
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