Slade, S. Connors, R. van Diemen, M. Ferrat, E. Haughey, S. Luz, S.
Neogi, M. Pathak, J. Petzold, J. Portugal Pereira, P. Vyas, E.
Huntley, K. Kissick, M. Belkacemi, J. Malley, (eds.)].
    \20\ IPCC, 2019: IPCC Special Report on the Ocean and Cryosphere
in a Changing Climate [H.-O. P[ouml]rtner, D.C. Roberts, V. Masson-
Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, A.
Alegr[iacute]a, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer
(eds.)].
    \21\ IPCC, 2021: Summary for Policymakers. In: Climate Change
2021: The Physical Science Basis. Contribution of Working Group I to
the Sixth Assessment Report of the Intergovernmental Panel on
Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L.
Connors, C. P[eacute]an, S. Berger, N. Caud, Y. Chen, L. Goldfarb,
M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K.
Maycock, T. Waterfield, O. Yelek[ccedil]i, R. Yu and B. Zhou
(eds.)]. Cambridge University Press. In Press.
---------------------------------------------------------------------------

     The NAS 2016 Attribution of Extreme Weather Events in the
Context of Climate Change,\22\ 2017 Valuing Climate Damages: Updating
Estimation of the Social Cost of Carbon Dioxide,\23\ and 2019 Climate
Change and Ecosystems \24\ assessments.
---------------------------------------------------------------------------

    \22\ National Academies of Sciences, Engineering, and Medicine.
2016. Attribution of Extreme Weather Events in the Context of
Climate Change. Washington, DC: The National Academies Press.
https://dio.org/10.17226/21852.
    \23\ National Academies of Sciences, Engineering, and Medicine.
2017. Valuing Climate Damages: Updating Estimation of the Social
Cost of Carbon Dioxide. Washington, DC: The National Academies
Press. https://doi.org/10.17226/24651.
    \24\ National Academies of Sciences, Engineering, and Medicine.
2019. Climate Change and Ecosystems. Washington, DC: The National
Academies Press. https://doi.org/10.17226/25504.
---------------------------------------------------------------------------

     National Oceanic and Atmospheric Administration's (NOAA)
annual State of the Climate reports published by the Bulletin of the
American Meteorological Society,\25\ most recently in August of 2020.
---------------------------------------------------------------------------

    \25\ Blunden, J., and D.S. Arndt, Eds., 2020: State of the
Climate in 2019. Bull. Amer. Meteor. Soc, S1-S429, https://doi.org/10.1175/2020BAMSStateoftheClimate.1.
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     EPA Climate Change and Social Vulnerability in the United
States: A Focus on Six Impacts (2021).\26\
---------------------------------------------------------------------------

    \26\ EPA. 2021. Climate Change and Social Vulnerability in the
United States: A Focus on Six Impacts. U.S. Environmental Protection
Agency, EPA 430-R-21-003.
---------------------------------------------------------------------------

    The most recent information demonstrates that the climate is
continuing to change in response to the human-induced buildup of GHGs
in the atmosphere. These recent assessments show that atmospheric
concentrations of GHGs have risen to a level that has no precedent in
human history and that they continue to climb, primarily as a result of
both historic and current anthropogenic emissions, and that these
elevated concentrations endanger our health by affecting our food and
water sources, the air we breathe, the weather we experience, and our
interactions with the natural and built environments. For example,
atmospheric concentrations of one of these GHGs, CO2,
measured at Mauna Loa in Hawaii and at other sites around the world
reached 414 ppm in 2020 (nearly 50 percent higher than pre-industrial
levels),\27\ and has continued to rise at a rapid rate. Global average
temperature has increased by about 1.1 degrees Celsius ([deg]C) (2.0
degrees Fahrenheit ([deg]F)) in the 2011-2020 decade relative to 1850-
1900.\28\ The years 2014-2020 were the warmest seven years in the 1880-
2020 record, contributing to the warmest decade on record with a
decadal temperature of 0.82 [deg]C (1.48 [deg]F) above the 20th
century.\29\ \30\ The IPCC determined (with medium confidence) that
this past decade was warmer than any multi-century period in at least
the past 100,000 years.\31\ Global average sea level has risen by about
8 inches (about 21 centimeters (cm)) from 1901 to 2018, with the rate
from 2006 to 2018 (0.15 inches/year or 3.7 millimeters (mm)/year)
almost twice the rate over the 1971 to 2006 period, and three times the
rate of the 1901 to 2018 period.\32\ The rate of sea level rise over
the 20th century was higher than in any other century in at least the
last 2,800 years.\33\ Higher CO2 concentrations have led to
acidification of the surface ocean in recent decades to an extent
unusual in the past 2 million years, with negative impacts on marine
organisms that use calcium carbonate to build shells or skeletons.\34\
Arctic sea ice extent continues to decline in all months of the year;
the most rapid reductions occur in September (very likely almost a 13
percent decrease per decade between 1979 and 2018) and are
unprecedented in at least 1,000 years.\35\ Human-induced climate change
has led to heatwaves and heavy precipitation becoming more frequent and
more intense, along with increases in

agricultural and ecological droughts \36\ in many regions.\37\
---------------------------------------------------------------------------

    \27\ https://climate.nasa.gov/vital-signs/carbon-dioxide/.
    \28\ IPCC, 2021.
    \29\ NOAA National Centers for Environmental Information, State
of the Climate: Global Climate Report for Annual 2020, published
online January 2021, retrieved on February 10, 2021 from https://www.ncdc.noaa.gov/sotc/global/202013.
    \30\ Blunden, J., and D.S. Arndt, Eds., 2020: State of the
Climate in 2019. Bull. Amer. Meteor. Soc, S1-S429, https://doi.org/10.1175/2020BAMSStateoftheClimate.1.
    \31\ IPCC, 2021.
    \32\ IPCC, 2021.
    \33\ USGCRP, 2018: Impacts, Risks, and Adaptation in the United
States: Fourth National Climate Assessment, Volume II [Reidmiller,
D.R., C.W. Avery, D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K.
Maycock, and B.C. Stewart (eds.)]. U.S. Global Change Research
Program, Washington, DC, USA, 1515 pp. doi: 10.7930/NCA4.2018.
    \34\ IPCC, 2021.
    \35\ IPCC, 2021.
    \36\ These are drought measures based on soil moisture.
    \37\ IPCC, 2021.
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    The assessment literature demonstrates that modest additional
amounts of warming may lead to a climate different from anything humans
have ever experienced. The present-day CO2 concentration of
414 ppm is already higher than at any time in the last 2 million
years.\38\ If concentrations exceed 450 ppm, they would likely be
higher than any time in the past 23 million years:\39\ at the current
rate of increase of more than 2 ppm a year, this would occur in about
15 years. While GHGs are not the only factor that controls climate, it
is illustrative that 3 million years ago (the last time CO2
concentrations were this high) Greenland was not yet completely covered
by ice and still supported forests, while 23 million years ago (the
last time concentrations were above 450 ppm) the West Antarctic ice
sheet was not yet developed, indicating the possibility that high GHGs
concentrations could lead to a world that looks very different from
today and from the conditions in which human civilization has
developed. If the Greenland and Antarctic ice sheets were to melt
substantially, sea levels would rise dramatically--the IPCC estimated
that over the next 2,000 years, sea level will rise by 7 to 10 feet
even if warming is limited to 1.5 [deg]C (2.7 [deg]F), from 7 to 20
feet if limited to 2 [deg]C (3.6 [deg]F), and by 60 to 70 feet if
warming is allowed to reach 5 [deg]C (9 [deg]F) above preindustrial
levels.\40\ For context, almost all of the city of Miami is less than
25 feet above sea level, and the NCA4 stated that 13 million Americans
would be at risk of migration due to 6 feet of sea level rise.
Moreover, the CO2 being absorbed by the ocean has resulted
in changes in ocean chemistry due to acidification of a magnitude not
seen in 65 million years,\41\ putting many marine species--particularly
calcifying species--at risk.
---------------------------------------------------------------------------

    \38\ IPCC, 2021.
    \39\ IPCC, 2013.
    \40\ IPCC, 2021.
    \41\ IPCC, 2018.
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    The NCA4 found that it is very likely (greater than 90 percent
likelihood) that by mid-century, the Arctic Ocean will be almost
entirely free of sea ice by late summer for the first time in about 2
million years.\42\ Coral reefs will be at risk for almost complete (99
percent) losses with 1 [deg]C (1.8 [deg]F) of additional warming from
today (2 [deg]C or 3.6 [deg]F since preindustrial). At this
temperature, between 8 and 18 percent of animal, plant, and insect
species could lose over half of the geographic area with suitable
climate for their survival, and 7 to 10 percent of rangeland livestock
would be projected to be lost.\43\
---------------------------------------------------------------------------

    \42\ USGCRP, 2018.
    \43\ IPCC, 2018.
---------------------------------------------------------------------------

    Every additional increment of temperature comes with consequences.
For example, the half degree of warming from 1.5 to 2 [deg]C (0.9
[deg]F of warming from 2.7 [deg]F to 3.6 [deg]F) above preindustrial
temperatures is projected on a global scale to expose 420 million more
people to frequent extreme heatwaves, and 62 million more people to
frequent exceptional heatwaves (where heatwaves are defined based on a
heat wave magnitude index which takes into account duration and
intensity--using this index, the 2003 French heat wave that led to
almost 15,000 deaths would be classified as an ``extreme heatwave'' and
the 2010 Russian heatwave which led to thousands of deaths and
extensive wildfires would be classified as ``exceptional''). It would
increase the frequency of sea-ice-free Arctic summers from once in a
hundred years to once in a decade. It could lead to 4 inches of
additional sea level rise by the end of the century, exposing an
additional 10 million people to risks of inundation, as well as
increasing the probability of triggering instabilities in either the
Greenland or Antarctic ice sheets. Between half a million and a million
additional square miles of permafrost would thaw over several
centuries. Risks to food security would increase from medium to high
for several lower income regions in the Sahel, southern Africa, the
Mediterranean, central Europe, and the Amazon. In addition to food
security issues, this temperature increase would have implications for
human health in terms of increasing ozone concentrations, heatwaves,
and vector-borne diseases (for example, expanding the range of the
mosquitoes which carry dengue fever, chikungunya, yellow fever, and the
Zika virus, or the ticks which carry Lyme. babesiosis, or Rocky
Mountain Spotted Fever).\44\ Moreover, every additional increment in
warming leads to larger changes in extremes, including the potential
for events unprecedented in the observational record. Every additional
degree will intensify extreme precipitation events by about 7 percent.
The peak winds of the most intense tropical cyclones (hurricanes) are
projected to increase with warming. In addition to a higher intensity,
the IPCC found that precipitation and frequency of rapid
intensification of these storms has already increased, while the
movement speed has decreased, and elevated sea levels have increased
coastal flooding, all of which make these tropical cyclones more
damaging.\45\
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    \44\ IPCC, 2018.
    \45\ IPCC, 2021.
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    The NCA4 also evaluated a number of impacts specific to the U.S.
Severe drought and outbreaks of insects like the mountain pine beetle
have killed hundreds of millions of trees in the western U.S. Wildfires
have burned more than 3.7 million acres in 14 of the 17 years between
2000 and 2016, and Federal wildfire suppression costs were about a
billion dollars annually.\46\ The National Interagency Fire Center has
documented U.S. wildfires since 1983, and the ten years with the
largest acreage burned have all occurred since 2004.\47\ Wildfire smoke
degrades air quality increasing health risks, and more frequent and
severe wildfires due to climate change would further diminish air
quality, increase incidences of respiratory illness, impair visibility,
and disrupt outdoor activities, sometimes thousands of miles from the
location of the fire. Meanwhile, sea level rise has amplified coastal
flooding and erosion impacts, requiring the installation of costly pump
stations, flooding streets, and increasing storm surge damages. Tens of
billions of dollars of U.S. real estate could be below sea level by
2050 under some scenarios. Increased frequency and duration of drought
will reduce agricultural productivity in some regions, accelerate
depletion of water supplies for irrigation, and expand the distribution
and incidence of pests and diseases for crops and livestock. The NCA4
also recognized that climate change can increase risks to national
security, both through direct impacts on military infrastructure, but
also by affecting factors such as food and water availability that can
exacerbate conflict outside U.S. borders. Droughts, floods, storm
surges, wildfires, and other extreme events stress nations and people
through loss of life, displacement of populations, and impacts on
livelihoods.\48\
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    \46\ USGCRP, 2018
    \47\ NIFC (National Interagency Fire Center). 2021. Total
wildland fires and acres (1983-2020). Accessed August 2021.
www.nifc.gov/fireInfo/fireInfo_stats_totalFires.html.
    \48\ USGCRP, 2018.
---------------------------------------------------------------------------

    Some GHGs also have impacts beyond those mediated through climate
change. For example, elevated concentrations of carbon dioxide
stimulate plant growth (which can be positive in the case of beneficial
species, but negative in terms of weeds and invasive species, and can
also lead to a reduction in plant

micronutrients) \49\ and cause ocean acidification. Nitrous oxide
depletes the levels of protective stratospheric ozone.\50\
---------------------------------------------------------------------------

    \49\ Ziska, L., A. Crimmins, A. Auclair, S. DeGrasse, J.F.
Garofalo, A.S. Khan, I. Loladze, A.A. P[eacute]rez de Le[oacute]n,
A.Showler, J. Thurston, and I. Walls, 2016: Ch. 7: Food Safety,
Nutrition, and Distribution. The Impacts of Climate Change on Human
Health in the United States: A Scientific Assessment. U.S. Global
Change Research Program, Washington, DC, 189-216. http://dx.doi.org/10.7930/J0ZP4417
    \50\ WMO (World Meteorological Organization), Scientific
Assessment of Ozone Depletion: 2018, Global Ozone Research and
Monitoring Project--Report No. 58, 588 pp., Geneva, Switzerland,
2018.
---------------------------------------------------------------------------

    As methane is the primary GHG addressed in this proposal, it is
relevant to highlight some specific trends and impacts specific to
methane. Concentrations of methane reached 1879 parts per billion (ppb)
in 2020, more than two and a half times the preindustrial concentration
of 722 ppb.\51\ Moreover, the 2020 concentration was an increase of
almost 13 ppb over 2019--the largest annual increase in methane
concentrations of the period since the early 1990s, continuing a trend
of rapid rise since a temporary pause ended in 2007.\52\ Methane has a
high radiative efficiency--almost 30 times that of carbon dioxide per
ppb (and therefore, 80 times as much per unit mass).\53\ In addition,
methane contributes to climate change through chemical reactions in the
atmosphere that produce tropospheric ozone and stratospheric water
vapor. Human emissions of methane are responsible for about one third
of the warming due to well-mixed GHGs, the second most important human
warming agent after carbon dioxide.\54\ Because of the substantial
emissions of methane, and its radiative efficiency, methane mitigation
is one of the best opportunities for reducing near term warming.
---------------------------------------------------------------------------

    \51\ Blunden et al., 2020.
    \52\ NOAA, https://gml.noaa.gov/webdata/ccgg/trends/ch4/ch4_annmean_gl.txt, accessed August 19th, 2021.
    \53\ IPCC, 2021.
    \54\ IPCC, 2021.
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    The tropospheric ozone produced by the reaction of methane in the
atmosphere has harmful effects for human health and plant growth in
addition to its climate effects.\55\ In remote areas, methane is an
important precursor to tropospheric ozone formation.\56\ Approximately
50 percent of the global annual mean ozone increase since preindustrial
times is believed to be due to anthropogenic methane.\57\ Projections
of future emissions also indicate that methane is likely to be a key
contributor to ozone concentrations in the future.\58\ Unlike
NOX and VOC, which affect ozone concentrations regionally
and at hourly time scales, methane emissions affect ozone
concentrations globally and on decadal time scales given methane's long
atmospheric lifetime when compared to these other ozone precursors.\59\
Reducing methane emissions, therefore, will contribute to efforts to
reduce global background ozone concentrations that contribute to the
incidence of ozone-related health effects.\60\ The benefits of such
reductions are global and occur in both urban and rural areas.
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    \55\ Nolte, C.G., P.D. Dolwick, N. Fann, L.W. Horowitz, V. Naik,
R.W. Pinder, T.L. Spero, D.A. Winner, and L.H. Ziska, 2018: Air
Quality. In Impacts, Risks, and Adaptation in the United States:
Fourth National Climate Assessment, Volume II [Reidmiller, D.R.,
C.W. Avery, D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K.
Maycock, and B.C. Stewart (eds.)]. U.S. Global Change Research
Program, Washington, DC, USA, pp. 512-538. doi: 10.7930/NCA4. 2018.
CH13
    \56\ U.S. EPA. 2013. ``Integrated Science Assessment for Ozone
and Related Photochemical Oxidants (Final Report).'' EPA-600-R-10-
076F. National Center for Environmental Assessment--RTP Division.
Available at http://www.epa.gov/ncea/isa/.
    \57\ Myhre, G., D. Shindell, F.-M. Br[eacute]on, W. Collins, J.
Fuglestvedt, J. Huang, D. Koch, J.-F. Lamarque, D. Lee, B. Mendoza,
T. Nakajima, A. Robock, G. Stephens, T. Takemura and H. Zhang, 2013:
Anthropogenic and Natural Radiative Forcing. In: Climate Change
2013: The Physical Science Basis. Contribution of Working Group I to
the Fifth Assessment Report of the Intergovernmental Panel on
Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor,
S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley
(eds.)]. Cambridge University Press, Cambridge, United Kingdom and
New York, NY, USA. Pg. 680.
    \58\ Ibid.
    \59\ Ibid.
    \60\ USGCRP, 2018.
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    These scientific assessments and documented observed changes in the
climate of the planet and of the U.S. present clear support regarding
the current and future dangers of climate change and the importance of
GHG mitigation.
2. VOC
    Many VOC can be classified as HAP (e.g., benzene),\61\ which can
lead to a variety of health concerns such as cancer and noncancer
illnesses (e.g., respiratory, neurological). Further, VOC are one of
the key precursors in the formation of ozone. Tropospheric, or ground-
level, ozone is formed through reactions of VOC and NOX in
the presence of sunlight. Ozone formation can be controlled to some
extent through reductions in emissions of the ozone precursors VOC and
NOX. Recent observational and modeling studies have found
that VOC emissions from oil and natural gas operations can impact ozone
levels.\62\ \63\ \64\ \65\ A significantly expanded body of scientific
evidence shows that ozone can cause a number of harmful effects on
health and the environment. Exposure to ozone can cause respiratory
system effects such as difficulty breathing and airway inflammation.
For people with lung diseases such as asthma and chronic obstructive
pulmonary disease (COPD), these effects can lead to emergency room
visits and hospital admissions. Studies have also found that ozone
exposure is likely to cause premature death from lung or heart
diseases. In addition, evidence indicates that long-term exposure to
ozone is likely to result in harmful respiratory effects, including
respiratory symptoms and the development of asthma. People most at risk
from breathing air containing ozone include children; people with
asthma and other respiratory diseases; older adults; and people who are
active outdoors, especially outdoor workers. An estimated 25.9 million
people have asthma in the U.S., including almost 7.1 million children.
Asthma disproportionately affects children, families with lower
incomes, and minorities, including Puerto Ricans, Native Americans/
Alaska Natives, and African Americans.\66\
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    \61\ Benzene Integrated Risk Information System (IRIS)
Assessment: https://cfpub.epa.gov/ncea/iris2/chemicalLanding.cfm?substance_nmbr=276.
    \62\ Benedict, K. B., Zhou, Y., Sive, B. C., Prenni, A. J.,
Gebhart, K. A., Fischer, E. V., . . . & Collett Jr, J. L. 2019.
Volatile organic compounds and ozone in Rocky Mountain National Park
during FRAPPE. Atmospheric Chemistry and Physics, 19(1), 499-521.
    \63\ Lindaas, J., Farmer, D. K., Pollack, I. B., Abeleira, A.,
Flocke, F., & Fischer, E. V. 2019. Acyl peroxy nitrates link oil and
natural gas emissions to high ozone abundances in the Colorado Front
Range during summer 2015. Journal of Geophysical Research:
Atmospheres, 124(4), 2336-2350.
    \64\ McDuffie, E. E., Edwards, P. M., Gilman, J. B., Lerner, B.
M., Dub[eacute], W. P., Trainer, M., . . . & Brown, S. S. 2016.
Influence of oil and gas emissions on summertime ozone in the
Colorado Northern Front Range. Journal of Geophysical Research:
Atmospheres, 121(14), 8712-8729.
    \65\ Tzompa[hyphen]Sosa, Z. A., & Fischer, E. V. 2021. Impacts
of emissions of C2[hyphen]C5 alkanes from the US oil and gas sector
on ozone and other secondary species. Journal of Geophysical
Research: Atmospheres, 126(1), e2019JD031935.
    \66\ National Health Interview Survey (NHIS) Data, 2011. http://www.cdc.gov/asthma/nhis/2011/data.htm.
---------------------------------------------------------------------------

    In the EPA's 2020 Integrated Science Assessment (ISA) for Ozone and
Related Photochemical Oxidants,\67\ the EPA estimates the incidence of
air pollution effects for those health endpoints above where the ISA
classified as either causal or likely-to-be-causal. In brief, the ISA
for ozone found short-term (less than one month) exposures to ozone to
be

causally related to respiratory effects, a ``likely to be causal''
relationship with metabolic effects and a ``suggestive of, but not
sufficient to infer, a causal relationship'' for central nervous system
effects, cardiovascular effects, and total mortality. The ISA reported
that long-term exposures (one month or longer) to ozone are ``likely to
be causal'' for respiratory effects including respiratory mortality,
and a ``suggestive of, but not sufficient to infer, a causal
relationship'' for cardiovascular effects, reproductive effects,
central nervous system effects, metabolic effects, and total mortality.
An example of quantified incidence of ozone health effects can be found
in the Regulatory Impact Analysis for the Final Revised Cross-State Air
Pollution Rule (CSAPR) Update.
---------------------------------------------------------------------------

    \67\ Integrated Science Assessment (ISA) for Ozone and Related
Photochemical Oxidants (Final Report). U.S. Environmental Protection
Agency, Washington, DC, EPA/600/R-20/012, 2020.
---------------------------------------------------------------------------

    Scientific evidence also shows that repeated exposure to ozone can
reduce growth and have other harmful effects on sensitive plants and
trees. These types of effects have the potential to impact ecosystems
and the benefits they provide.
3. SO2
    Current scientific evidence links short-term exposures to
SO2, ranging from 5 minutes to 24 hours, with an array of
adverse respiratory effects including bronchoconstriction and increased
asthma symptoms. These effects are particularly important for
asthmatics at elevated ventilation rates (e.g., while exercising or
playing).
    Studies also show an association between short-term exposure and
increased visits to emergency departments and hospital admissions for
respiratory illnesses, particularly in at-risk populations including
children, the elderly, and asthmatics.
    SO2 in the air can also damage the leaves of plants,
decrease their ability to produce food--photosynthesis--and decrease
their growth. In addition to directly affecting plants, SO2,
when deposited on land and in estuaries, lakes, and streams, can
acidify sensitive ecosystems resulting in a range of harmful indirect
effects on plants, soils, water quality, and fish and wildlife (e.g.,
changes in biodiversity and loss of habitat, reduced tree growth, loss
of fish species). Sulfur deposition to waterways also plays a causal
role in the methylation of mercury.\68\
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    \68\ U.S. EPA. Integrated Science Assessment (ISA) for Oxides of
Nitrogen and Sulfur Ecological Criteria (2008 Final Report). U.S.
Environmental Protection Agency, Washington, DC, EPA/600/R-08/082F,
2008.
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B. Oil and Natural Gas Industry and Its Emissions

    This section generally describes the structure of the Oil and
Natural Gas Industry, the interconnected production, processing,
transmission and storage, and distribution segments that move product
from well to market, and types of emissions sources in each segment and
the industry's emissions.
1. Oil and Natural Gas Industry--Structure
    The EPA characterizes the oil and natural gas industry's operations
as being generally composed of four segments: (1) Extraction and
production of crude oil and natural gas (``oil and natural gas
production''), (2) natural gas processing, (3) natural gas transmission
and storage, and (4) natural gas distribution.\69\ \70\ The EPA
regulates oil refineries as a separate source category; accordingly, as
with the previous oil and gas NSPS rulemakings, for purposes of this
proposed rulemaking, for crude oil, the EPA's focus is on operations
from the well to the point of custody transfer at a petroleum refinery,
while for natural gas, the focus is on all operations from the well to
the local distribution company custody transfer station commonly
referred to as the ``city-gate.'' \71\
---------------------------------------------------------------------------

    \69\ The EPA previously described an overview of the sector in
section 2.0 of the 2011 Background Technical Support Document to 40
CFR part 60, subpart OOOO, located at Docket ID Item No. EPA-HQ-OAR-
2010-0505-0045, and section 2.0 of the 2016 Background Technical
Support Document to 40 CFR part 60, subpart OOOOa, located at Docket
ID Item No. EPA-HQ-OAR-2010-0505-7631.
    \70\ While generally oil and natural gas production includes
both onshore and offshore operations, 40 CFR part 60, subpart OOOOa
addresses onshore operations.
    \71\ For regulatory purposes, the EPA defines the Crude Oil and
Natural Gas source category to mean (1) Crude oil production, which
includes the well and extends to the point of custody transfer to
the crude oil transmission pipeline or any other forms of
transportation; and (2) Natural gas production, processing,
transmission, and storage, which include the well and extend to, but
do not include, the local distribution company custody transfer
station. The distribution segment is not part of the defined source
category.
---------------------------------------------------------------------------

a. Production Segment
    The oil and natural gas production segment includes the wells and
all related processes used in the extraction, production, recovery,
lifting, stabilization, and separation or treatment of oil and/or
natural gas (including condensate). Although many wells produce a
combination of oil and natural gas, wells can generally be grouped into
two categories, oil wells and natural gas wells. Oil wells comprise two
types, oil wells that produce crude oil only and oil wells that produce
both crude oil and natural gas (commonly referred to as ``associated''
gas). Production equipment and components located on the well pad may
include, but are not limited to, wells and related casing heads; tubing
heads; ``Christmas tree'' piping, pumps, compressors; heater treaters;
separators; storage vessels; pneumatic devices; and dehydrators.
Production operations include well drilling, completion, and
recompletion processes, including all the portable non-self-propelled
apparatuses associated with those operations.
    Other sites that are part of the production segment include
``centralized tank batteries,'' stand-alone sites where oil,
condensate, produced water, and natural gas from several wells may be
separated, stored, or treated. The production segment also includes
gathering pipelines, gathering and boosting compressor stations, and
related components that collect and transport the oil, natural gas, and
other materials and wastes from the wells to the refineries or natural
gas processing plants.
    Of these products, crude oil and natural gas undergo successive,
separate processing. Crude oil is separated from water and other
impurities and transported to a refinery via truck, railcar, or
pipeline. As noted above, the EPA treats oil refineries as a separate
source category, accordingly, for present purposes, the oil component
of the production segment ends at the point of custody transfer at the
refinery.\72\
---------------------------------------------------------------------------

    \72\ See 40 CFR part 60, subparts J and Ja, and 40 CFR part 63,
subparts CC and UUU.
---------------------------------------------------------------------------

    The separated, unprocessed natural gas is commonly referred to as
field gas and is composed of methane, natural gas liquids (NGL), and
other impurities, such as water vapor, H2S, CO2,
helium, and nitrogen. Ethane, propane, butane, isobutane, and pentane
are all considered NGL and often are sold separately for a variety of
different uses. Natural gas with high methane content is referred to as
``dry gas,'' while natural gas with significant amounts of ethane,
propane, or butane is referred to as ``wet gas.'' Natural gas typically
is sent to gas processing plants in order to separate NGLs for use as
feedstock for petrochemical plants, burned for space heating and
cooking, or blended into vehicle fuel.
b. Processing Segment
    The natural gas processing segment consists of separating certain
hydrocarbons (HC) and fluids from the natural gas to produce ``pipeline
quality'' dry natural gas. The degree and

location of processing is dependent on factors such as the type of
natural gas (e.g., wet or dry gas), market conditions, and company
contract specifications. Typically, processing of natural gas begins in
the field and continues as the gas is moved from the field through
gathering and boosting compressor stations to natural gas processing
plants, where the complete processing of natural gas takes place.
Natural gas processing operations separate and recover NGL or other
non-methane gases and liquids from field gas through one or more of the
following processes: oil and condensate separation, water removal,
separation of NGL, sulfur and CO2 removal, fractionation of
NGL, and other processes, such as the capture of CO2
separated from natural gas streams for delivery outside the facility.
c. Transmission and Storage Segment
    Once natural gas processing is complete, the resulting natural gas
exits the natural gas process plant and enters the transmission and
storage segment where it is transmitted to storage and/or distribution
to the end user.
    Pipelines in the natural gas transmission and storage segment can
be interstate pipelines, which carry natural gas across state
boundaries, or intrastate pipelines, which transport the gas within a
single state. Basic components of the two types of pipelines are the
same, though interstate pipelines may be of a larger diameter and
operated at a higher pressure. To ensure that the natural gas continues
to flow through the pipeline, the natural gas must periodically be
compressed, thereby increasing its pressure. Compressor stations
perform this function and are usually placed at 40- to 100-mile
intervals along the pipeline. At a compressor station, the natural gas
enters the station, where it is compressed by reciprocating or
centrifugal compressors.
    Another part of the transmission and storage segment are
aboveground and underground natural gas storage facilities. Storage
facilities hold natural gas for use during peak seasons. The main
difference between underground and aboveground storage sites is that
storage takes place in storage vessels constructed of non-earthen
materials in aboveground storage. Underground storage of natural gas
typically occurs in depleted natural gas or oil reservoirs and salt
dome caverns. One purpose of this storage is for load balancing
(equalizing the receipt and delivery of natural gas). At an underground
storage site, typically other processes occur, including compression,
dehydration, and flow measurement.
d. Distribution Segment
    The distribution segment provides the final step in delivering
natural gas to customers.\73\ The natural gas enters the distribution
segment from delivery points located along interstate and intrastate
transmission pipelines to business and household customers. The
delivery point where the natural gas leaves the transmission and
storage segment and enters the distribution segment is a local
distribution company's custody transfer station, commonly referred to
as the ``city-gate.'' Natural gas distribution systems consist of over
2 million miles of piping, including mains and service pipelines to the
customers. If the distribution network is large, compressor stations
may be necessary to maintain flow; however, these stations are
typically smaller than transmission compressor stations. Distribution
systems include metering stations and regulating stations, which allow
distribution companies to monitor the natural gas as it flows through
the system.
---------------------------------------------------------------------------

    \73\ The distribution segment is not included in the definition
of the Crude Oil and Natural Gas source category that is currently
regulated under 40 CFR part 60, subpart OOOOa.
---------------------------------------------------------------------------

2. Oil and Natural Gas Industry--Emissions
    The oil and natural gas industry sector is the largest source of
industrial methane emissions in the U.S.\74\ Natural gas is comprised
primarily of methane; every natural gas leak or intentional release
through venting or other industrial processes constitutes a release of
methane. Methane is a potent greenhouse gas; over a 100-year timeframe,
it is nearly 30 times more powerful at trapping climate warming heat
than CO2, and over a 20-year timeframe, it is 83 times more
powerful.\75\ Because methane is a powerful greenhouse gas and is
emitted in large quantities, reductions in methane emissions provide a
significant benefit in reducing near-term warming. Indeed, one third of
the warming due to GHGs that we are experiencing today is due to human
emissions of methane. Additionally, the Crude Oil and Natural Gas
sector emits, in varying concentrations and amounts, a wide range of
other health-harming pollutants, including VOCs, SO2,
NOX, H2S, CS2, and COS. The year 2016
modeling platform produced by U.S. EPA estimated about 3 million tons
of VOC are emitted by oil and gas-related sources.\76\
---------------------------------------------------------------------------

    \74\ H.R. Rep. No. 117-64, 4 (2021) (Report by the House
Committee on Energy and Commerce concerning H.J. Res. 34, to
disapprove the 2020 Policy Rule) (House Report).
    \75\ IPCC, 2021.
    \76\ https://www.epa.gov/sites/default/files/2020-11/documents/2016v1_emismod_tsd_508.pdf.
---------------------------------------------------------------------------

    Emissions of methane and these co-pollutants occur in every segment
of the Crude Oil and Natural Gas source category. Many of the processes
and equipment types that contribute to these emissions are found in
every segment of the source category and are highly similar across
segments. Emissions from the crude oil portion of the regulated source
category result primarily from field production operations, such as
venting of associated gas from oil wells, oil storage vessels, and
production-related equipment such as gas dehydrators, pig traps, and
pneumatic devices. Emissions from the natural gas portion of the
industry can occur in all segments. As natural gas moves through the
system, emissions primarily result from intentional venting through
normal operations, routine maintenance, unintentional fugitive
emissions, flaring, malfunctions, and system upsets. Venting can occur
through equipment design or operational practices, such as the
continuous and intermittent bleed of gas from pneumatic controllers
(devices that control gas flows, levels, temperatures, and pressures in
the equipment). In addition to vented emissions, emissions can occur
from leaking equipment (also referred to as fugitive emissions) in all
parts of the infrastructure, including major production and processing
equipment (e.g., separators or storage vessels) and individual
components (e.g., valves or connectors). Flares are commonly used
throughout each segment in the Oil and Natural Gas Industry as a
control device to provide pressure relief to prevent risk of explosions
and to destroy methane, which has a high global warming potential, and
convert it to CO2 which has a lower global warming
potential, and to also control other air pollutants such as VOC.
    ``Super-emitting'' events, sites, or equipment, where a small
proportion of sources account for a large proportion of overall
emissions, can occur throughout the Oil and Natural Gas Industry and
have been observed to occur in the equipment types and activities
covered by this proposed action. There are a number of definitions for
the term ``super-emitter.'' A 2018 National Academies of Sciences,
Engineering, and Medicine report \77\ on methane discussed three
categories of ``high-emitting'' sources:
---------------------------------------------------------------------------

    \77\ https://www.nap.edu/download/24987#.

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

     Routine or ``chronic'' high-emitting sources, which
regularly emit at higher rates relative to ``peers'' in a sample.
Examples include large facilities, or large emissions at smaller
facilities caused by poor design or operational practices.
     Episodic high-emitting sources, which are typically large
in nature and are generally intentional releases from known maintenance
events at a facility. Examples include gas well liquids unloading, well
workovers and maintenance activities, and compressor station or
pipeline blowdowns.
     Malfunctioning high-emitting sources, which can be either
intermittent or prolonged in nature and result from malfunctions and
poor work practices. Examples include malfunctioning intermittent
pneumatic controllers and stuck open dump valves. Another example is
well blowout events. For example, a 2018 well blowout in Ohio was
estimated to have emitted over 60,000 tons of methane.\78\
---------------------------------------------------------------------------

    \78\ Pandey et al. (2019). Satellite observations reveal extreme
methane leakage from a natural gas well blowout. PNAS December 26,
2019 116 (52) 26376-26381.
---------------------------------------------------------------------------

    Super-emitters have been observed at many different scales, from
site-level to component-level, across many research studies.\79\
Studies will often develop a study-specific definition such as a top
percentile of emissions in a study population (e.g., top 10 percent),
emissions exceeding a certain threshold (e.g., 26 kg/day), emissions
over a certain detection threshold (e.g., 1-3 g/s) or as facilities
with the highest proportional emission rate.\80\ For certain equipment
types and activities, the EPA's GHG emission estimates include the full
range of conditions, including ``super-emitters.'' For other
situations, where data are available, emissions estimates for abnormal
events are calculated separately and included in the Inventory of U.S.
Greenhouse Gas Emissions and Sinks (``GHGI'') (e.g., Aliso Canyon leak
event).\81\ Given the variability of practices and technologies across
oil and gas systems and the occurrence of episodic events, it is
possible that the EPA's estimates do not include all methane emissions
from abnormal events. The EPA continues to work through its stakeholder
process to review new data from the EPA's Greenhouse Gas Reporting
Program (``GHGRP'') petroleum and natural gas systems source category
(40 CFR part 98, subpart W, also referred to as ``GHGRP subpart W'')
and research studies to assess how emissions estimates can be improved.
Because lost gas, whether through fugitive emissions, unintentional gas
carry through, or intentional releases, represents lost earning
potential, the industry benefits from capturing and selling emissions
of natural gas (and methane). Limiting super-emitters through actions
included in this rule such as reducing fugitive emissions, using lower
emitting equipment where feasible, and employing best management
practices will not only reduce emissions but reduce the loss of revenue
from this valuable commodity.
---------------------------------------------------------------------------

    \79\ See for example, Brandt, A., Heath, G., Cooley, D. (2016)
Methane leaks from natural gas systems follow extreme distributions.
Environ. Sci. Technol., DOI: 10.1021/acs.est.6b04303; Zavala-Araiza,
D., Alvarez, R.A., Lyon, D.R., Allen, D.T., Marchese, A.J.,
Zimmerle, D.J., & Hamburg, S.P. (2017). Super-emitters in natural
gas infrastructure are caused by abnormal process conditions. Nature
communications, 8, 14012; Mitchell, A., et al. (2015), Measurements
of Methane Emissions from Natural Gas Gathering Facilities and
Processing Plants: Measurement Results. Environmental Science &
Technology, 49(5), 3219-3227; Allen, D., et al. (2014), Methane
Emissions from Process Equipment at Natural Gas Production Sites in
the United States: Pneumatic Controllers. Environmental Science &
Technology.
    \80\ Caulton et al. (2019). Importance of Super-emitter Natural
Gas Well Pads in the Marcellus Shale. Environ. Sci. Technol. 2019,
53, 4747-4754; Zavala-Araiza, D., Alvarez, R., Lyon, D, et al.
(2016). Super-emitters in natural gas infrastructure are caused by
abnormal process conditions. Nat Commun 8, 14012 (2017). https://www.nature.com/articles/ncomms14012; Lyon, et al. (2016). Aerial
Surveys of Elevated Hydrocarbon Emissions from Oil and Gas
Production Sites. Environ. Sci. Technol. 2016, 50, 4877-4886.
https://pubs.acs.org/doi/10.1021/acs.est.6b00705; and Zavala-Araiza
D, et al. (2015). Toward a functional definition of methane
superemitters: Application to natural gas production sites. 49
ENVTL. SCI. & TECH. 8167, 8168 (2015). https://pubs.acs.org/doi/10.1021/acs.est.5b00133.
    \81\ The EPA's emission estimates in the GHGI are developed with
the best data available at the time of their development, including
data from the Greenhouse Gas Reporting Program (GHGRP) in 40 CFR
part 98, subpart W, and from recent research studies. GHGRP subpart
W emissions data used in the GHGI are quantified by reporters using
direct measurements, engineering calculations, or emission factors,
as specified by the regulation. The EPA has a multi-step data
verification process for GHGRP subpart W data, including automatic
checks during data-entry, statistical analyses on completed reports,
and staff review of the reported data. Based on the results of the
verification process, the EPA follows up with facilities to resolve
mistakes that may have occurred.
---------------------------------------------------------------------------

    Below we provide estimated emissions of methane, VOC, and
SO2 from Oil and Natural Gas Industry operation sources.
    Methane emissions in the U.S. and from the Oil and Natural Gas
industry. Official U.S. estimates of national level GHG emissions and
sinks are developed by the EPA for the GHGI in fulfillment of
commitments under the United Nations Framework Convention on Climate
Change. The GHGI, which includes recent trends, is organized by
industrial sector. The oil and natural gas production, natural gas
processing, and natural gas transmission and storage sectors emit 28
percent of U.S. anthropogenic methane. Table 7 below presents total
U.S. anthropogenic methane emissions for the years 1990, 2010, and
2019.
    In accordance with the practice of the EPA GHGI, the EPA GHGRP, and
international reporting standards under the UN Framework Convention on
Climate Change, the 2007 IPCC Fourth Assessment Report value of the
methane 100-year GWP is used for weighting emissions in the following
tables. The 100-year GWP value of 25 for methane indicates that one ton
of methane has approximately as much climate impact over a 100-year
period as 25 tons of carbon dioxide. The most recent IPCC AR6
assessment has estimated a slightly larger 100-year GWP of methane of
almost 30 (specifically, either 27.2 or 29.8 depending on whether the
value includes the carbon dioxide produced by the oxidation of methane
in the atmosphere). As mentioned earlier, because methane has a shorter
lifetime than carbon dioxide, the emissions of a ton of methane will
have more impact earlier in the 100-year timespan and less impact later
in the 100-year timespan relative to the emissions of a 100-year GWP-
equivalent quantity of carbon dioxide: When using the AR6 20-year GWP
of 81, which only looks at impacts over the next 20 years, the total US
emissions of methane in 2019 would be equivalent to about 2140 MMT
CO2.

                                    Table 7--U.S. Methane Emissions by Sector
                          [Million metric tons carbon dioxide equivalent (MMT CO2 EQ.)]
----------------------------------------------------------------------------------------------------------------
                             Sector                                    1990            2010            2019
----------------------------------------------------------------------------------------------------------------
Oil and Natural Gas Production, and Natural Gas Processing and               189             176             182
 Transmission and Storage.......................................
Landfills.......................................................             177             124             114
Enteric Fermentation............................................             165             172             179

Coal Mining.....................................................              96              82              47
Manure Management...............................................              37              55              62
Other Oil and Gas Sources.......................................              46              17              15
Wastewater Treatment............................................              20              19              18
Other Methane Sources \82\......................................              46              47              42
                                                                 -----------------------------------------------
    Total Methane Emissions.....................................             777             692             660
----------------------------------------------------------------------------------------------------------------
Emissions from the Inventory of United States Greenhouse Gas Emissions and Sinks: 1990-2019 (published April 14,
  2021), calculated using GWP of 25. Note: Totals may not sum due to rounding.

    Table 8 below presents total methane emissions from natural gas
production through transmission and storage and petroleum production,
for years 1990, 2010, and 2019, in MMT CO2 Eq. (or million
metric tons CO2 Eq.) of methane.
---------------------------------------------------------------------------

    \82\ Other sources include rice cultivation, forest land,
stationary combustion, abandoned oil and natural gas wells,
abandoned coal mines, mobile combustion, composting, and several
sources emitting less than 1 MMT CO2 Eq. in 2019.

                     Table 8--U.S. Methane Emissions From Natural Gas and Petroleum Systems
                                                  [MMT CO2 EQ.]
----------------------------------------------------------------------------------------------------------------
                             Sector                                    1990            2010            2019
----------------------------------------------------------------------------------------------------------------
Natural Gas Production..........................................              63              97              94
Natural Gas Processing..........................................              21              10              12
Natural Gas Transmission and Storage............................              57              30              37
Petroleum Production............................................              48              39              38
----------------------------------------------------------------------------------------------------------------
Emissions from the Inventory of United States Greenhouse Gas Emissions and Sinks: 1990-2019 (published April 14,
  2021), calculated using GWP of 25. Note: Totals may not sum due to rounding.

    Global GHG Emissions. For additional background information and
context, we used 2018 World Resources Institute Climate Watch data to
make comparisons between U.S. oil and natural gas production and
natural gas processing and transmission and storage emissions and the
emissions inventories of entire countries and regions.\83\ The U.S.
methane emissions from oil and natural gas production and natural gas
processing and transmission and storage constitute 0.4 percent of total
global emissions of all GHGs (48,601 MMT CO2 Eq.) from all sources.\84\
Ranking U.S. emissions of methane from oil and natural gas production
and natural gas processing and transmission and storage against total
GHG emissions for entire countries (using 2018 Climate Watch data),
shows that these emissions are comparatively large as they exceed the
national-level emissions totals for all GHGs and all anthropogenic
sources for Colombia, the Czech Republic, Chile, Belgium, and over 160
other countries. What that means is that the U.S. emits more of a
single GHG--methane--from a single sector--the oil and gas sector--than
the total combined GHGs emitted by 164 out of 194 total countries.
Furthermore, U.S. emissions of methane from oil and natural gas
production and natural gas processing and transmission and storage are
greater than the sum of total emissions of 64 of the lowest-emitting
countries and territories, using the 2018 Climate Watch data set.
---------------------------------------------------------------------------

    \83\ The Climate Watch figures presented here come from the PIK
PRIMAP-hist dataset included on Climate Watch. The PIK PRIMAP-hist
dataset combines the United Nations Framework Convention on Climate
Change (UNFCCC) reported data where available and fills gaps with
other sources. It does not include land use change and forestry but
covers all other sectors. https://www.climatewatchdata.org/ghg-emissions?end_year=2018&source=PIK&start_year=1990.
---------------------------------------------------------------------------

    As illustrated by the domestic and global GHGs comparison data
summarized above, the collective GHG emissions from the Crude Oil and
Natural Gas source category are significant, whether the comparison is
domestic (where this sector is the largest source of methane emissions,
accounting for 28 percent of U.S. methane and 3 percent of total U.S.
emissions of all GHGs), global (where this sector, accounting for 0.4
percent of all global GHG emissions, emits more than the total national
emissions of over 160 countries, and combined emissions of over 60
countries), or when both the domestic and global GHG emissions
comparisons are viewed in combination. Consideration of the global
context is important. GHG emissions from U.S. Oil and Natural Gas
production and natural gas processing and transmission and storage will
become globally well-mixed in the atmosphere, and thus will have an
effect on the U.S. regional climate, as well as the global climate as a
whole for years and indeed many decades to come. No single GHG source
category dominates on the global scale. While the Crude Oil and Natural
Gas source category, like many (if not all) individual GHG source
categories, could appear small in comparison to total emissions, in
fact, it is a very important contributor in terms of both absolute
emissions, and in comparison to other source categories globally or
within the U.S.
    The IPCC AR6 assessment determined that ``From a physical science
perspective, limiting human-induced global warming to a specific level
requires limiting cumulative CO2 emissions, reaching at
least net zero CO2 emissions, along with strong reductions
in other GHG emissions.'' The report also singled out the importance of
``strong and sustained CH4 emission reductions'' in part due
to the short lifetime of methane leading to the near-term cooling from
reductions in methane emissions, which can offset the warming that will
result due to reductions in emissions of cooling aerosols such as
SO2. Therefore, reducing methane emissions globally is an
important facet in any strategy to limit warming. In the oil and gas
sector,

methane reductions are highly achievable and cost-effective using
existing and well-known solutions and technologies that actually result
in recovery of saleable product.
    VOC and SO2 emissions in the U.S. and from the oil and
natural gas industry. Official U.S. estimates of national level VOC and
SO2 emissions are developed by the EPA for the National
Emissions Inventory (NEI), for which States are required to submit
information under 40 CFR part 51, subpart A. Data in the NEI may be
organized by various data points, including sector, NAICS code, and
Source Classification Code. Tables 9 and 10 below present total U.S.
VOC and SO2 emissions by sector, respectively, for the year
2017, in kilotons (kt) (or thousand metric tons). The oil and natural
gas sector represents the top anthropogenic U.S. sector for VOC
emissions after removing the biogenics and wildfire sectors in Table 9
(about 20% of the total VOC emitting by anthropogenic sources). About
2.5 percent of the total U.S. anthropogenic SO2 comes from
the oil and natural gas sector.

                  Table 9--U.S. VOC Emissions by Sector
                                  [kt]
------------------------------------------------------------------------
                         Sector                                2017
------------------------------------------------------------------------
Biogenics--Vegetation and Soil..........................          25,823
Fires--Wildfires........................................           4,578
Oil and Natural Gas Production, and Natural Gas                    2,504
 Processing and Transmission............................
Fires--Prescribed Fires.................................           2,042
Solvent--Consumer and Commercial Solvent Use............           1,610
Mobile--On-Road non-Diesel Light Duty Vehicles..........           1,507
Mobile--Non-Road Equipment--Gasoline....................           1,009
Other VOC Sources \85\..................................           4,045
                                                         ---------------
    Total VOC Emissions.................................          43,118
------------------------------------------------------------------------
Emissions from the 2017 NEI (released April 2020). Note: Totals may not
  sum due to rounding.

                 Table 10--U.S. SO2 Emissions by Sector
                                  [kt]
------------------------------------------------------------------------
                         Sector                                2017
------------------------------------------------------------------------
Fuel Combustion--Electric Generation--Coal..............           1,319
Fuel Combustion--Industrial Boilers, Internal Combustion             212
 Engines--Coal..........................................
Mobile--Commercial Marine Vessels.......................             183
Industrial Processes--Not Elsewhere Classified..........             138
Fires--Wildfires........................................             135
Industrial Processes--Chemical Manufacturing............             123
Oil and Natural Gas Production and Natural Gas                        65
 Processing and Transmission............................
Other SO2 Sources \86\..................................             551
                                                         ---------------
    Total SO2 Emissions.................................           2,726
------------------------------------------------------------------------
Emissions from the 2017 NEI (released April 2020). Note: Totals may not
  sum due to rounding.

    Table 11 below presents total VOC and SO2 emissions from
oil and natural gas production through transmission and storage, for
the year 2017, in kt. The contribution to the total anthropogenic VOC
emissions budget from the oil and gas sector has been increasing in
recent NEI cycles. In the 2017 NEI, the oil and gas sector makes up
about 25 percent of the total VOC emissions from anthropogenic sources.
The SO2 emissions have been declining in just about every
anthropogenic sector, but the oil and gas sector is an exception where
SO2 emissions have been slightly increasing or remaining
steady in some cases in recent years.
---------------------------------------------------------------------------

    \85\ Other sources include remaining sources emitting less than
1,000 kt VOC in 2017.
    \86\ Other sources include remaining sources emitting less than
100 kt SO2 in 2017.

   Table 11--U.S. VOC and SO2 Emissions From Natural Gas and Petroleum
                                 Systems
                                  [kt]
------------------------------------------------------------------------
                 Sector                         VOC             SO2
------------------------------------------------------------------------
Oil and Natural Gas Production..........           2,478              41
Natural Gas Processing..................              12              23
Natural Gas Transmission and Storage....              14               1
------------------------------------------------------------------------
Emissions from the 2017 NEI, (published April 2020), in kt (or thousand
  metric tons). Note: Totals may not sum due to rounding.

IV. Statutory Background and Regulatory History

A. Statutory Background of CAA Sections 111(b), 111(d) and General
Implementing Regulations

    The EPA's authority for this rule is CAA section 111, which governs
the establishment of standards of performance for stationary sources.
This section requires the EPA to list source categories to be
regulated, establish standards of performance for air pollutants
emitted by new sources in that source category, and establish EG for
States to establish standards of performance for certain pollutants
emitted by existing sources in that source category.
    Specifically, CAA section 111(b)(1)(A) requires that a source
category be included on the list for regulation if, ``in [the EPA
Administrator's] judgment it causes, or contributes significantly to,
air pollution which may reasonably be anticipated to endanger public
health or welfare.'' This determination is commonly referred to as an
``endangerment finding'' and that phrase encompasses both of the
``causes or contributes significantly to'' component and the ``endanger
public health or welfare'' component of the determination. Once a
source category is listed, CAA section 111(b)(1)(B) requires that the
EPA propose and then promulgate ``standards of performance'' for new
sources in such source category. CAA section 111(a)(1) defines a
``standard of performance'' as ``a standard for emissions of air
pollutants which reflects the degree of emission limitation achievable
through the application of the best system of emission reduction which
(taking into account the cost of achieving such reduction and any non-
air quality health and environmental impact and energy requirements)
the Administrator determines has been adequately demonstrated.'' As
long recognized by the D.C. Circuit, ``[b]ecause Congress did not
assign the specific weight the Administrator should accord each of
these factors, the Administrator is free to exercise his discretion in
this area.'' New York v. Reilly, 969 F.2d 1147, 1150 (D.C. Cir. 1992).
See also Lignite Energy Council v. EPA, 198 F.3d 930, 933 (D.C. Cir.
1999) (``Lignite Energy Council'') (``Because section 111 does not set
forth the weight that be [sic] should assigned to each of these
factors, we have granted the agency a great degree of discretion in
balancing them'').
    In determining whether a given system of emission reduction
qualifies as ``the best system of emission reduction . . . adequately
demonstrated,'' or ``BSER,'' CAA section 111(a)(1) requires that the
EPA take into account, among other factors, ``the cost of achieving
such reduction.'' As described in the proposal \87\ for the 2016 Rule
(85 FR 35824, June 3, 2016), the U.S. Court of Appeals for the District
of Columbia Circuit (the D.C. Circuit) has stated that in light of this
provision, the EPA may not adopt a standard the cost of which would be
``exorbitant,'' \88\ ``greater than the industry could bear and
survive,'' \89\ ``excessive,'' \90\ or ``unreasonable.'' \91\ These
formulations appear to be synonymous, and for convenience, in this
rulemaking, as in previous rulemakings, we will use reasonableness as
the standard, so that a control technology may be considered the ``best
system of emission reduction . . . adequately demonstrated'' if its
costs are reasonable, but cannot be considered the BSER if its costs
are unreasonable. See 80 FR 64662, 64720-21 (October 23, 2015).
---------------------------------------------------------------------------

    \87\ 80 FR 56593, 56616 (September 18, 2015).
    \88\ Lignite Energy Council, 198 F.3d at 933.
    \89\ Portland Cement Ass'n v. EPA, 513 F.2d 506, 508 (D.C. Cir.
1975).
    \90\ Sierra Club v. Costle, 657 F.2d 298, 343 (D.C. Cir. 1981).
    \91\ Id.
---------------------------------------------------------------------------

    CAA section 111(a) does not provide specific direction regarding
what metric or metrics to use in considering costs, affording the EPA
considerable discretion in choosing a means of cost consideration.\92\
In this rulemaking, we evaluated whether a control cost is reasonable
under a number of approaches that we find appropriate for assessing the
types of controls at issue. For example, in evaluating controls for
reducing VOC and methane emissions from new sources, we considered a
control's cost effectiveness under both a ``single pollutant cost-
effectiveness'' approach and a ``multipollutant cost-effectiveness''
approach, in order to appropriately take into account that the systems
of emission reduction considered in this rule typically achieve
reductions in multiple pollutants at once and secure a multiplicity of
climate and public health benefits.\93\ We also evaluated costs at a
sector level by assessing the projected new capital expenditures
required under the proposal (compared to overall new capital
expenditures by the sector) and the projected compliance costs
(compared to overall annual revenue for the sector) if the rule were to
require such controls. For a detailed discussion of these cost
approaches, please see section IX of the proposal preamble.
---------------------------------------------------------------------------

    \92\ See, e.g., Husqvarna AB v. EPA, 254 F.3d 195, 200 (D.C.
Cir. 2001) (where CAA section 213 does not mandate a specific method
of cost analysis, the EPA may make a reasoned choice as to how to
analyze costs).
    \93\ We believe that both the single and multipollutant
approaches are appropriate for assessing the reasonableness of the
multipollutant controls considered in this action. The EPA has
considered similar approaches in the past when considering multiple
pollutants that are controlled by a given control option. See e.g.,
80 FR 56616-56617; 73 FR 64079-64083 and EPA Document ID Nos. EPA-
HQ-OAR-2004-0022-0622, EPA-HQ-OAR-2004-0022-0447, EPA-HQ-OAR-2004-
0022-0448.
---------------------------------------------------------------------------

    As defined in CAA section 111(a), the ``standard of performance''
that the EPA develops, based on the BSER, is expressed as a performance
level (typically, a rate-based standard). CAA section 111(b)(5)
precludes the EPA from prescribing a particular technological system
that must be used to comply with a standard of performance. Rather,
sources can select any measure or combination of measures that will
achieve the standard.
    CAA section 111(h)(1) authorizes the Administrator to promulgate
``a design, equipment, work practice, or operational standard, or
combination thereof'' if in his or her judgment, ``it is not feasible
to prescribe or enforce a standard of performance.'' CAA section
111(h)(2) provides the circumstances under which prescribing or
enforcing a standard of performance is ``not feasible,'' such as, when
the pollutant cannot be emitted through a conveyance designed to emit
or capture the pollutant, or when there is no practicable measurement
methodology for the particular class of sources.\94\ CAA section
111(b)(1)(B) requires the EPA to ``at least every 8 years review and,
if appropriate, revise'' performance standards unless the
``Administrator determines that such review is not appropriate in light
of readily available information on the efficacy'' of the standard.
---------------------------------------------------------------------------

    \94\ The EPA notes that design, equipment, work practice or
operational standards established under CAA section 111(h) (commonly
referred to as ``work practice standards'') reflect the ``best
technological system of continuous emission reduction'' and that
this phrasing differs from the ``best system of emission reduction''
phrase in the definition of ``standard of performance'' in CAA
section 111(a)(1). Although the differences in these phrases may be
meaningful in other contexts, for purposes of evaluating the sources
and systems of emission reduction at issue in this rulemaking, the
EPA has applied these concepts in an essentially comparable manner.
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    As mentioned above, once the EPA lists a source category under CAA
section 111(b)(1)(A), CAA section 111(b)(1)(B) provides the EPA
discretion to determine the pollutants and sources to be regulated. In
addition, concurrent with the 8-year review (and though not a mandatory
part of the 8-year review), the EPA may examine whether to add
standards for pollutants or emission

sources not currently regulated for that source category.
    Once the EPA establishes NSPS in a particular source category, the
EPA is required in certain circumstances to issue EG to reduce
emissions from existing sources in that same source category.
Specifically, CAA section 111(d) requires that the EPA prescribe
regulations to establish procedures under which States submit plans to
establish, implement, and enforce standards of performance for existing
sources for certain air pollutants to which a Federal NSPS would apply
if such existing source were a new source. The EPA addresses this CAA
requirement both through its promulgation of general implementing
regulations for section 111(d) as well as specific EG. The EPA first
published general implementing regulations in 1975, 40 FR 53340
(November 17, 1975) (codified at 40 CFR part 60, subpart B), and has
revised its section 111(d) implementing regulations several times, most
recently on July 8, 2019, 84 FR 32520 (codified at 40 CFR part 60,
subpart Ba).\95\ In accordance with CAA section 111(d), States are
required to submit plans pursuant to these regulations to establish
standards of performance for existing sources for any air pollutant:
(1) The emission of which is subject to a Federal NSPS; and (2) which
is neither a pollutant regulated under CAA section 108(a) (i.e.,
criteria pollutants such as ground-level ozone and particulate matter,
and their precursors, like VOC) \96\ or a HAP regulated under CAA
section 112. See also definition of ``designated pollutant'' in 40 CFR
60.21a(a). The EPA's general implementing regulations use the term
``designated facility'' to identify those existing sources that may be
subject to regulation under this provision of CAA section 111(d). See
40 CFR 60.21a(b).
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    \95\ Subpart Ba provides for the applicability of its provisions
upon final publication of an EG if such EG is published after July
8, 2019. Sec.  60.20a(a). The EPA acknowledges that the D.C. Circuit
has vacated certain timing provisions within subpart Ba. Am. Lung
Assoc. v. EPA, 985 F.3d 914 (D.C. Cir. 2021), petition for cert.
pending, No. 20-1778 (filed June 23, 2001) (Am. Lung Assoc.).
However, the court did not vacate the applicability provision,
therefore subpart Ba applies to any EG finalized from this proposal.
The Agency plans to undertake rulemaking to address the provisions
vacated under the court's decision in the near future.
    \96\ VOC are not listed as CAA section 108(a) pollutants, but
they are regulated precursors to photochemical oxidants (e.g.,
ozone) and particulate matter (PM), both of which are listed CAA
section 108(a) pollutants, and VOC therefore fall within the CAA
108(a) exclusion. Accordingly, promulgation of NSPS for VOC does not
trigger the application of CAA section 111(d).
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    While States are authorized to establish standards of performance
for designated facilities, there is a fundamental obligation under CAA
section 111(d) that such standards of performance reflect the degree of
emission limitation achievable through the application of the BSER, as
determined by the Administrator. This obligation derives from the
definition of ``standard of performance'' under CAA section 111(a)(1),
which makes no distinction between new-source and existing-source
standards. The EPA identifies the degree of emission limitation
achievable through application of the BSER as part of its EG. See 40
CFR 60.22a(b)(5). While standards of performance must generally reflect
the degree of emission limitation achievable through application of the
BSER, CAA section 111(d)(1) also requires that the EPA regulations
permit the States, in applying a standard of performance to a
particular source, to take into account the source's remaining useful
life and other factors.
    After the EPA issues final EG per the requirements under CAA
section 111(d) and 40 CFR part 60, subpart Ba, States are required to
submit plans that establish standards of performance for the designated
facilities as defined in the EPA's guidelines and that contain other
measures to implement and enforce those standards. The EPA's final EG
issued under CAA section 111(d) do not impose binding requirements
directly on sources, but instead provide requirements for States in
developing their plans and criteria for assisting the EPA when judging
the adequacy of such plans. Under CAA section 111(d), and the EPA's
implementing regulations, a State must submit its plan to the EPA for
approval, the EPA will evaluate the plan for completeness in accordance
with enumerated criteria, and then will act on that plan via a
rulemaking process to either approve or disapprove the plan in whole or
in part. If a State does not submit a plan, or if the EPA does not
approve a State's plan because it is not ``satisfactory,'' then the EPA
must establish a Federal plan for that State.\97\ If EPA approves a
State's plan, the provisions in the state plan become federally
enforceable against the designated facility responsible for compliance
in the same manner as the provisions of an approved State
implementation plan under CAA section 110. If no designated facility is
located within a State, the State must submit to the EPA a letter
certifying to that effect in lieu of submitting a State plan. See 40
CFR 60.23a(b).
---------------------------------------------------------------------------

    \97\ CAA section 111(d)(2)(A).
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    Designated facilities located in Indian country would not be
addressed by a State's CAA section 111(d) plan. Instead, an eligible
Tribe that has one or more designated facilities located in its area of
Indian country \98\ would have the opportunity, but not the obligation,
to seek authority and submit a plan that establishes standards of
performance for those facilities on its Tribal lands.\99\ If a Tribe
does not submit a plan, or if the EPA does not approve a Tribe's plan,
then the EPA has the authority to establish a Federal plan for that
Tribe.\100\
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    \98\ The EPA is aware of many oil and natural gas operations
located in Indian Country.
    \99\ See 40 CFR part 49, subpart A.
    \100\ CAA section 111(d)(2)(A).
---------------------------------------------------------------------------

B. What is the regulatory history and litigation background of NSPS and
EG for the oil and natural gas industry?
1. 1979 Listing of Source Category
    Subsequent to the enactment of the CAA of 1970, the EPA took action
to develop standards of performance for new stationary sources as
directed by Congress in CAA section 111. By 1977, the EPA had
promulgated NSPS for a total of 27 source categories, while NSPS for an
additional 25 source categories were then under development.\101\
However, in amending the CAA that year, Congress expressed
dissatisfaction that the EPA's pace was too slow. Accordingly, the 1977
CAA Amendments included a new subsection (f) in section 111, which
specified a schedule for the EPA to list additional source categories
under CAA section 111(b)(1)(A) and prioritize them for regulation under
CAA section 111(b)(1)(B).
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    \101\ See 44 FR 49222 (August 21, 1979).
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    In 1979, as required by CAA section 111(f), the EPA published a
list of source categories, which included ``Crude Oil and Natural Gas
Production,'' for which the EPA would promulgate standards of
performance under CAA section 111(b). See Priority List and Additions
to the List of Categories of Stationary Sources, 44 FR 49222 (August
21, 1979) (``1979 Priority List''). That list included, in the order of
priority for promulgating standards, source categories that the EPA
Administrator had determined, pursuant to CAA section 111(b)(1)(A),
contribute significantly to air pollution that may reasonably be
anticipated to endanger public health or welfare. See 44 FR 49223
(August 21, 1979); see also 49 FR 2636-37 (January 20, 1984).

2. 1985 NSPS for VOC and SO2 Emissions From Natural Gas
Processing Units
    On June 24, 1985 (50 FR 26122), the EPA promulgated NSPS for the
Crude Oil and Natural Gas source category that addressed VOC emissions
from equipment leaks at onshore natural gas processing plants (40 CFR
part 60, subpart KKK). On October 1, 1985 (50 FR 40158), the EPA
promulgated additional NSPS for the source category to regulate
SO2 emissions from onshore natural gas processing plants (40
CFR part 60, subpart LLL).
3. 2012 NSPS OOOO Rule and Related Amendments
    In 2012, pursuant to its duty under CAA section 111(b)(1)(B) to
review and, if appropriate, revise the 1985 NSPS, the EPA published the
final rule, ``Standards of Performance for Crude Oil and Natural Gas
Production, Transmission and Distribution,'' 77 FR 49490 (August 16,
2012) (40 CFR part 60, subpart OOOO) (``2012 NSPS OOOO''). The 2012
rule updated the SO2 standards for sweetening units and the
VOC standards for equipment leaks at onshore natural gas processing
plants. In addition, it established VOC standards for several oil and
natural gas-related operations emission sources not covered by 40 CFR
part 60, subparts KKK and LLL, including natural gas well completions,
centrifugal and reciprocating compressors, certain natural gas operated
pneumatic controllers in the production and processing segments of the
industry, and storage vessels in the production, processing, and
transmission and storage segments.
    In 2013, 2014, and 2015 the EPA amended the 2012 NSPS OOOO rule in
order to address implementation of the standards. ``Oil and Natural Gas
Sector: Reconsideration of Certain Provisions of New Source Performance
Standards,'' 78 FR 58416 (September 23, 2013) (``2013 NSPS OOOO'')
(concerning storage vessel implementation); ``Oil and Natural Gas
Sector: Reconsideration of Additional Provisions of New Source
Performance Standards,'' 79 FR 79018 (December 31, 2014) (``2014 NSPS
OOOO'') (concerning well completion); ``Oil and Natural Gas Sector:
Definitions of Low Pressure Gas Well and Storage Vessel,'' 80 FR 48262
(August 12, 2015) (``2015 NSPS OOOO'') (concerning low pressure gas
wells and storage vessels).
    The EPA received petitions for both judicial review and
administrative reconsiderations for the 2012, 2013, and 2014 NSPS OOOO
rules. The EPA denied reconsideration for some issues, see
``Reconsideration of the Oil and Natural Gas Sector: New Source
Performance Standards; Final Action,'' 81 FR 52778 (August 10, 2016),
and, as noted below, granted reconsideration for other issues. As
explained below, all litigation related to NSPS OOOO is currently in
abeyance.
4. 2016 NSPS OOOOa Rule and Related Amendments
    Regulatory action. On June 3, 2016, the EPA published a final rule
titled ``Oil and Natural Gas Sector: Emission Standards for New,
Reconstructed, and Modified Sources; Final Rule,'' at 81 FR 35824 (40
CFR part 60, subpart OOOOa) (``2016 Rule'' or ``2016 NSPS
OOOOa'').102 103 The 2016 NSPS OOOOa rule established NSPS
for sources of GHGs and VOC emissions for certain equipment, processes,
and operations across the Oil and Natural Gas Industry, including in
the transmission and storage segment. 81 FR at 35832. The EPA explained
that the 1979 listing identified the source category broadly enough to
include that segment and, in the alternative, if the listing had
limited the source category to the production and processing segments,
the EPA affirmatively expanded the source category to include the
transmission and storage segment on grounds that operations in those
segments are a sequence of functions that are interrelated and
necessary for getting the recovered gas ready for distribution. 81 FR
at 35832. In addition, because this rule was the first time that the
EPA had promulgated NSPS for GHG emissions from the Crude Oil and
Natural Gas source category, the EPA predicated those NSPS on a
determination that it had a rational basis to regulate GHG emissions
from the source category. 81 FR at 35843. In response to comments, the
EPA explained that it was not required to make an additional pollutant-
specific finding that GHG emissions from the source category contribute
significantly to dangerous air pollution, but in the alternative, the
EPA did make such a finding, relying on the same information that it
relied on when determining that it had a rational basis to promulgate a
GHGs NSPS. 81 FR at 35843.
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    \102\ The June 3, 2016, rulemaking also included certain final
amendments to 40 CFR part 60, subpart OOOO, to address issues on
which the EPA had granted reconsideration.
    \103\ The EPA review which resulted in the 2016 NSPS OOOOa rule
was instigated by a series of directives from then-President Obama
targeted at reducing GHGs, including methane: The President's
Climate Action Plan (June 2013); the President's Climate Action
Plan: Strategy to Reduce Methane Emissions (``Methane Strategy'')
(March 2014); and the President's goal to address, propose and set
standards for methane and ozone-forming emissions from new and
modified sources in the sector (January 2015, https://obamawhitehouse.archives.gov/the-press-office/2015/01/14/fact-sheet-Administration-takes-steps-forward-climate-action-plan-anno-1).
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    Specifically, the 2016 NSPS OOOOa addresses the following emission
sources:
     Sources that were unregulated under the 2012 NSPS OOOO
(hydraulically fractured oil well completions, pneumatic pumps, and
fugitive emissions from well sites and compressor stations);
     Sources that were regulated under the 2012 NSPS OOOO for
VOC emissions, but not for GHG emissions (hydraulically fractured gas
well completions and equipment leaks at natural gas processing plants);
and
     Certain equipment that is used across the source category,
of which the 2012 NSPS OOOO regulated emissions of VOC from only a
subset (pneumatic controllers, centrifugal compressors, and
reciprocating compressors, with the exception of those compressors
located at well sites).
    On March 12, 2018 (83 FR 10628), the EPA finalized amendments to
certain aspects of the 2016 NSPS OOOOa requirements for the collection
of fugitive emission components at well sites and compressor stations,
specifically (1) the requirement that components on a delay of repair
must conduct repairs during unscheduled or emergency vent blowdowns,
and (2) the monitoring survey requirements for well sites located on
the Alaska North Slope.
    Petitions for judicial review and to reconsider. Following
promulgation of the 2016 NSPS OOOOa rule, several states and industry
associations challenged the rule in the D.C. Circuit. The Administrator
also received five petitions for reconsideration of several provisions
of the final rule. Copies of the petitions are posted in Docket ID No.
EPA-HQ-OAR-2010-0505.\104\ As noted below, the EPA granted
reconsideration as to several issues raised with respect to the 2016
NSPS OOOOa rule and finalized certain modifications discussed in the
next section. As explained below, all litigation challenging the 2016
NSPS OOOOa rule is currently stayed.
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    \104\ See Docket ID Item Nos.: EPA-HQ-OAR-2010-0505-7682, EPA-
HQ-OAR-2010-0505-7683, EPA-HQ-OAR-2010-0505-7684, EPA-HQ-OAR-2010-
0505-7685, EPA-HQ-OAR-2010-0505-7686.
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5. 2020 Policy and Technical Rules
    Regulatory action. In September 2020, the EPA published two final
rules to amend 2012 NSPS OOOO and 2016 NSPS OOOOa. The first is titled,
``Oil

and Natural Gas Sector: Emission Standards for New, Reconstructed, and
Modified Sources Review.'' 85 FR 57018 (September 14, 2020). Commonly
referred to as the 2020 Policy Rule, it first rescinded the regulations
applicable to the transmission and storage segment on the basis that
the 1979 listing limited the source category to the production and
processing segments and that the transmission and storage segment is
not ``sufficiently related'' to the production and processing segments,
and therefore cannot be part of the same source category. 85 FR at
57027, 57029. In addition, the 2020 Policy Rule rescinded methane
requirements for the industry's production and processing segments on
two separate bases. The first was that such standards are redundant to
VOC standards for these segments. 85 FR at 57030. The second was that
the rule interpreted section 111 to require, or at least authorize the
Administrator to require, a pollutant-specific ``significant
contribution finding'' (SCF) as a prerequisite to a NSPS for a
pollutant, and to require that such finding be supported by some
identified standard or established set of criteria for determining
which contributions are ``significant.'' 85 FR at 57034. The rule went
on to conclude that the alternative significant-contribution finding
that the EPA made in the 2016 Rule for GHG emissions was flawed because
it accounted for emissions from the transmission and storage segment
and because it was not supported by criteria or a threshold. 85 FR at
57038.\105\
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    \105\ Following the promulgation of the 2020 Policy Rule, the
EPA promulgated a final rule that identified a standard or criteria
for determining which contributions are ``significant,'' which the
D.C. Circuit vacated. ``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.'' 86 FR 2542 (Jan. 13,
2021), vacated by California v. EPA, No. 21-1035 (D.C. Cir.) (Order,
April 5, 2021, Doc. #1893155).
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    Published on September 15, 2020, the second of the two rules is
titled, ``Oil and Natural Gas Sector: Emission Standards for New,
Reconstructed, and Modified Sources Reconsideration.'' Commonly
referred to as the 2020 Technical Rule, this second rule made further
amendments to the 2016 NSPS OOOOa following the 2020 Policy Rule to
eliminate or reduce certain monitoring obligations and to address a
range of issues in response to administrative petitions for
reconsideration and other technical and implementation issues brought
to the EPA's attention since the 2016 NSPS OOOOa rulemaking.
Specifically, the 2020 Technical Rule exempted low-production well
sites from fugitives monitoring (previously required semiannually),
required semiannual monitoring at gathering and boosting compressor
stations (previously quarterly), streamlined recordkeeping and
reporting requirements, allowed compliance with certain equivalent
State requirements as an alternative to NSPS fugitive requirements,
streamlined the application process to request the use of new
technologies to monitor for fugitive emissions, addressed storage tank
batteries for applicability determination purposes and finalized
several technical corrections. Because the 2020 Technical Rule was
issued the day after the EPA's rescission of methane regulations in the
2020 Policy Rule, the amendments made in the 2020 Technical Rule
applied only to the requirements to regulate VOC emissions from this
source category. The 2020 Policy Rule amended 40 CFR part 60, subparts
OOOO and OOOOa, as finalized in 2016. The 2020 Technical Rule amended
the 40 CFR part 60, subpart OOOOa, as amended by the 2020 Policy Rule.
    Petitions to reconsider. The EPA received three petitions for
reconsideration of the 2020 rulemakings. Two of the petitions sought
reconsideration of the 2020 Policy Rule. As discussed below, on June
30, 2021, the President signed into law S.J. Res. 14, a joint
resolution under the CRA disapproving the 2020 Policy Rule, and as a
result, the petitions for reconsideration on the 2020 Policy Rule are
now moot. All three petitions sought reconsideration of certain
elements of the 2020 Technical Rule.
    Litigation. Several States and non-governmental organizations
challenged the 2020 Policy Rule as well as the 2020 Technical Rule. All
petitions for review regarding the 2020 Policy Rule were consolidated
into one case in the D.C. Circuit. State of California, et al. v. EPA,
No. 20-1357. On August 25, 2021, after the enactment of the joint
resolution of Congress disapproving the 2020 Policy Rule (explained in
section VIII below), the court granted petitioners motion to
voluntarily dismiss their cases. Id. ECF Dkt #1911437. All petitions
for review regarding the 2020 Technical Rule were consolidated into a
different case in the D.C. Circuit. Environmental Defense Fund, et al.
v. EPA, No. 20-1360 (D.C. Cir.). On February 19, 2021, the court issued
an order granting a motion by the EPA to hold in abeyance the
consolidated litigation over the 2020 Technical Rule pending EPA's
rulemaking actions in response to E.O. 13990 and pending the conclusion
of EPA's potential reconsideration of the 2020 Technical Rule. Id. ECF
Dkt #1886335.
    As mentioned above, the EPA received petitions for judicial review
regarding the 2012, 2013, and 2014 NSPS OOOO rules as well as the 2016
NSPS OOOOa rule. The challenges to the 2012 NSPS OOOO rule (as amended
by the 2013 NSPS OOOO and 2014 NSPS OOOO rules) were consolidated.
American Petroleum Institute v. EPA, No. 13-1108 (D.C. Cir.). The
majority of those cases were further consolidated with the consolidated
challenges to the 2016 NSPS OOOOa rule. West Virginia v. EPA, No. 16-
1264 (D.C. Cir.), see specifically ECF Dkt #1654072. As such, West
Virginia v. EPA includes challenges to the 2012 NSPS OOOO rule (as
amended by the 2013 NSPS OOOO and 2014 NSPS OOOO rules) as well as
challenges to the 2016 NSPS OOOOa rule.\106\ On December 10, 2020, the
court granted a joint motion of the parties in West Virginia v. EPA to
hold that case in abeyance until after the mandate has issued in the
case regarding challenges to the 2020 Technical Rule. West Virginia v.
EPA, ECF Dkt #1875192.
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    \106\ When the EPA issued the 2016 NSPS OOOOa rule, a challenge
to the 2012 NSPS OOOO rule for failing to regulate methane was
severed and assigned to a separate case, NRDC v. EPA, No. 16-1425
(D.C. Cir.), pending judicial review of the 2016 NSPS OOOOa in
American Petroleum Institute v. EPA, No. 13-1108 (D.C. Cir.).
---------------------------------------------------------------------------

C. Congressional Review Act (CRA) Joint Resolution of Disapproval

    On June 30, 2021, the President signed into law a joint resolution
of Congress, S.J. Res. 14, adopted under the CRA,\107\ disapproving the
2020 Policy Rule.\108\ By the terms of the CRA, the signing into law of
the CRA joint resolution of disapproval means that the 2020 Policy Rule
is ``treated as though [it] had never taken effect.'' 5 U.S.C. 801(f).
As a result, the VOC and methane standards for the transmission and
storage segment, as well as the methane standards for the production
and processing segments--all of which had been rescinded in the 2020
Policy Rule--remain in effect. In addition, the EPA's authority and
obligation to require the States to regulate existing sources of
methane in the Crude Oil and

Natural Gas source category under section 111(d) of the CAA also
remains in effect.
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    \107\ The Congressional Review Act was adopted in Subtitle E of
the Small Business Regulatory Enforcement Fairness Act of 1996.
    \108\ ``Oil and Natural Gas Sector: Emission Standards for New,
Reconstructed, and Modified Sources Review,'' 85 FR 57018 (Sept. 14,
2020) (``2020 Policy Rule'').
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    The CRA resolution did not address the 2020 Technical Rule;
therefore, those amendments remain in effect with respect to the VOC
standards for the production and processing segments in effect at the
time of its enactment. As part of this rulemaking, in sections VIII and
X the EPA discusses the impact of the CRA resolution, and identifies
and proposes appropriate changes to reinstate the regulatory text that
had been rescinded by the 2020 Policy Rule and to resolve any
discrepancies in the regulatory text between the 2016 NSPS OOOOa Rule
and 2020 Technical Rule.

V. Related Emissions Reduction Efforts

    This section summarizes related State actions and other Federal
actions regulating oil and natural gas emissions sources and summarizes
industry and voluntary efforts to reduce climate change. The proposed
NSPS OOOOb and EG OOOOc include specific measures that build on the
experience and knowledge the Agency and industry have gained through
voluntary programs, as well as the leadership of the States in
pioneering new regulatory programs. The proposed NSPS OOOOb and EG
OOOOc consists of reasonable, proven, cost-effective technologies and
practices that reflect the evolutionary nature of the Oil and Natural
Gas Industry and proactive regulatory and voluntary efforts. The EPA
intends that the requirements proposed in this document will spur all
industry stakeholders in all parts of the country to apply these
readily available and cost-effective measures.

A. Related State Actions and Other Federal Actions Regulating Oil and
Natural Gas Sources

    The EPA recognizes that several States and other Federal agencies
currently regulate the Oil and Natural Gas Industry. The EPA also
recognizes that these State and other Federal agency regulatory
programs have matured since the EPA began implementing its 2012 NSPS
and subsequent 2016 NSPS. The EPA further acknowledges the technical
innovations that the Oil and Natural Gas Industry has made during the
past decade; this industry is fast-paced and constantly changing based
on the latest technology. The EPA commends these efforts and recognizes
States for their innovative standards, alternative compliance options,
and implementation strategies. The EPA recognizes that any one effort
will not be enough to address the increasingly dangerous impacts of
climate change on public health and welfare and believes that
consistent Federal regulation of the Crude Oil and Natural Gas source
category plays an important role. To have a meaningful impact on
climate change and its impact to human health and the environment, a
multifaceted approach needs to be taken to ensure methane reductions
will be realized. The EPA also recognizes that States and other Federal
agencies regulate in accordance with their own authorities and within
their own respective jurisdictions, and collectively do not fully
address the range of sources and emission reduction measures contained
in this proposal. Direct Federal regulation of methane from new sources
combined with the approved State plans that are consistent with the
EPA's EG for existing sources will bring national consistency to level
the regulatory playing field, help promote technological innovation,
and reduce both climate- and other health-harming pollution from a
large number of sources that are either currently unregulated or where
additional cost-effective reductions can be obtained. The EPA is
committed to working within its authority to provide opportunities to
align its programs with other existing State and Federal programs to
reduce unnecessary regulatory redundancy where appropriate.
    Among assessing various studies and emissions data, the EPA
reviewed many current and proposed State regulatory programs to
identify potential regulatory options that could be considered for
BSER.\109\ For example, the EPA reviewed California, Colorado, and
Canadian regulations, as well as a pending proposed rule in New Mexico,
that require non-emitting pneumatic devices at certain facilities and
in certain circumstances. The EPA also examined California, Colorado,
New Mexico (proposed), Pennsylvania, Wyoming, and the Bureau of Land
Management (BLM) standards for liquids unloading events. Some of these
States have led the way in regulating emissions sources that were not
yet subject to requirements under the NSPS OOOOa. For example, Colorado
requires the use of best management practices to minimize hydrocarbon
emissions and the need for well venting associated with downhole well
maintenance and liquids unloading, unless venting is necessary for
safety. Other States, such as New Mexico, are evaluating similar
requirements. Other States have requirements for emission sources
currently regulated under NSPS OOOOa that are more stringent. For
example, California and Colorado require continuous bleed natural gas-
driven pneumatic controllers be non-emitting, with specified
exceptions. We recognize that, in some cases, the EPA's proposed NSPS
and/or EG may be more stringent than existing programs and, in other
cases, may be less stringent than existing programs. After careful
review and consideration of State regulatory programs in place and
proposed State regulations, we are proposing NSPS and EG that, when
implemented, will reduce emissions of harmful air pollutants, promote
gas capture and beneficial use, and provide opportunity for flexibility
and expanded transparency in order to yield a consistent and
accountable national program that provides a clear path for States and
other Federal agencies to further partner to ensure their programs work
in conjunction with each other.
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    \109\ The NSPS OOOOb and EG TSD provides a high-level summary of
the state programs that the agency assessed for purposes of this
proposal.
---------------------------------------------------------------------------

    As an example of how the EPA strives to work with sources in States
that have overlapping regulations for the Oil and Natural Gas Industry,
the 2020 Technical Rule included approval of certain State programs as
alternatives to certain requirements in the Federal NSPS. Subject to
certain caveats, the EPA deemed certain fugitive emissions standards
for well sites and compressor stations located in specific States
equivalent to the NSPS in an effort to reduce any regulatory burden
imposed by duplicative State and Federal regulations. See 40 CFR
60.5399a. The EPA worked extensively with States and reviewed many
details of many State programs in this effort. Further, the 2020
Technical Rule amended 40 CFR part 60, subpart OOOOa, to incorporate a
process that allows other States not already listed in 40 CFR 60.5399a
to request approval of their fugitive monitoring program as an
alternative to the NSPS. The EPA is proposing to include a similar
request and approval process in NSPS OOOOb. Further, the EPA plans to
work closely with States as they develop their State plans pursuant to
the EG to look for opportunities to reduce unnecessary administrative
burden imposed by redundant and duplicative regulatory requirements and
help States that want to establish more stringent standards.
    In addition to States, certain Federal agencies also regulate
aspects of the oil and natural gas industry pursuant to their own
authorities and have other established programs affecting the industry.
The EPA believes that Federal regulatory actions and efforts will
provide other environmental co-

benefits, but the EPA recognizes itself to be the Federal agency that
has primary responsibility to protect human health and the environment
and has been given the unique responsibility and authority by Congress
to address the suite of harmful air pollutants associated with this
source category. The EPA further believes that to have a meaningful
impact to address the dangers of climate change, it is going to require
an ``all hands-on deck'' effort across all States and all Federal
agencies. The EPA has maintained an ongoing dialogue with its Federal
partners during the development of this proposed rule to minimize any
potential regulatory conflicts and to minimize confusion and regulatory
burden on the part of owners and operators. The below description
summarizes other agencies' regulations and other established Federal
programs.
    The U.S. Department of the Interior (DOI) regulates the extraction
of oil and gas from Federal lands. Bureaus within the DOI include BLM
and the Bureau of Ocean Energy Management (BOEM). The BLM manages the
Federal Government's onshore subsurface mineral estate--about 700
million acres (30 percent of the U.S.)--for the benefit of the American
public. The BLM maintains an oil and gas leasing program pursuant to
the Mineral Leasing Act, the Mineral Leasing Act for Acquired Lands,
the Federal Land Management and Policy Act, and the Federal Oil and Gas
Royalty Management Act. Pursuant to a delegation of Secretarial
authority, the BLM also oversees oil and gas operations on many Indian/
Tribal leases. The BLM's oil and gas operating regulations are found in
43 CFR part 3160. An oil and gas operator's general environmental and
safety obligations are found at 43 CFR 3162.5. The BLM does not
directly regulate emissions for the purposes of air quality. However,
BLM does regulate venting and flaring of natural gas for the purposes
of preventing waste. The governing Resource Management Plan may require
lessees to follow State and the EPA emissions regulations. An operator
may be required to control/mitigate emissions as a condition of
approval (COA) on a drilling permit. The need for such a COA is
determined by the environmental review process. The BLM's rules
governing the venting and flaring of gas are contained in NTL-4A, which
was issued in 1980. Under NTL-4A, limitations on royalty-free venting
and flaring constitute the primary mechanism for addressing the surface
waste of gas. In 2016, the BLM replaced NTL-4A with a new rule
governing venting and flaring (``Waste Prevention Rule''). In addition
to restricting royalty-free flaring, the rule set emissions standards
for tanks and pneumatic equipment and established LDAR requirements. In
2020, a U.S. District Court of Wyoming largely vacated that rule,
thereby reinstating NTL-4A. More detailed information can be found at
the BLM's website: https://www.blm.gov/programs/energy-and-minerals/oil-and-gas/operations-and-production/methane-and-waste-prevention-rule.
    The BOEM manages the development of U.S. Outer Continental Shelf
(offshore) energy and mineral resources. BOEM has air quality
jurisdiction in the Gulf of Mexico \110\ and the North Slope Borough of
Alaska.\111\ BOEM also has air jurisdiction in Federal waters on the
Outer Continental Shelf 3-9 miles offshore (depending on State) and
beyond. The Outer Continental Shelf Lands Act (OCSLA) section 5(a)(8)
states, ``The Secretary of the Interior is authorized to prescribe
regulations `for compliance with the national ambient air quality
standards pursuant to the CAA . . . to the extent that activities
authorized under [the Outer Continental Shelf Lands Act] significantly
affect the air quality of any State.' '' The EPA and States have the
air jurisdiction onshore and in State waters, and the EPA has air
jurisdiction offshore in certain areas. More detailed information can
be found at BOEM's website: https://www.boem.gov/.
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    \110\ The CAA gave BOEM air jurisdiction west of 87.5[deg]
longitude in the Gulf of Mexico region.
    \111\ The Consolidated Appropriations Act of 2012 gave BOEM air
jurisdiction in the North Slope Borough of Alaska.
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    The U.S. Department of Transportation (DOT) manages the U.S.
transportation system. Within DOT, the Pipeline and Hazardous Materials
Safety Administration (PHMSA) is responsible for regulating and
ensuring the safe and secure transport of energy and other hazardous
materials to industry and consumers by all modes of transportation,
including pipelines. While PHMSA regulatory requirements for gas
pipeline facilities have focused on human safety, which has attendant
environmental co-benefits, the ``Protecting our Infrastructure of
Pipelines and Enhancing Safety Act of 2020'' (Pub. L. 116-260, Division
R; ``PIPES Act of 2020''), which was signed into law on December 27,
2020, revised PHMSA organic statutes to emphasize the centrality of
environmental safety and protection of the environment in PHMSA
decision making. For example, the PHMSA's Office of Pipeline Safety
ensures safety in the design, construction, operation, maintenance, and
incident response of the U.S.' approximately 2.6 million miles of
natural gas and hazardous liquid transportation pipelines. When
pipelines are maintained, the likelihood of environmental releases like
leaks are reduced.\112\ In addition, the PIPES Act of 2020 contains
several provisions that specifically address the minimization of
releases of natural gas from pipeline facilities, such as a mandate
that the Secretary of Transportation promulgate regulations related to
gas pipeline LDAR programs. More detailed information can be found at
PHMSA's website: https://www.phmsa.dot.gov/.
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    \112\ See Final Report on Leak Detection Study to PHMSA.
December 10, 2012. https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/technical-resources/pipeline/16691/leak-detection-study.pdf.
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    The U.S. Department of Energy (DOE) develops oil and natural gas
policies and funds research on advanced fuels and monitoring and
measurement technologies. Specifically, the Advanced Research Projects
Agency-Energy (ARPA-E) program advances high-potential, high-impact
energy technologies that are too early for private-sector investment.
APRA-E awardees are unique because they are developing entirely new
technologies. More detailed information can be found at ARPA-E's
website: https://arpa-e.energy.gov/. Also, the U.S. Energy Information
Administration (EIA) compiles data on energy consumption, prices,
including natural gas, and coal. More detailed information can be found
at the EIA's website: https://www.eia.gov/.
    The U.S. Federal Energy Regulatory Commission (FERC) is an
independent agency that regulates the interstate transmission of
electricity, natural gas,\113\ and oil.\114\ FERC also reviews
proposals to build liquefied natural gas terminals and interstate
natural gas pipelines as well as licensing hydropower projects. The
Commission's responsibilities for the crude oil industry include the
following: Regulation of rates and practices of oil pipeline companies
engaged in interstate transportation; establishment of equal service
conditions to provide shippers with equal access to pipeline
transportation; and establishment of reasonable rates for transporting
petroleum and petroleum products by pipeline. The Commission's
responsibilities for the natural gas industry include the following:
Regulation of pipeline, storage, and

liquefied natural gas facility construction; regulation of natural gas
transportation in interstate commerce; issuance of certificates of
public convenience and necessity to prospective companies providing
energy services or constructing and operating interstate pipelines and
storage facilities; regulation of facility abandonment, establishment
of rates for services; regulation of the transportation of natural gas
as authorized by the Natural Gas Policy Act and OCSLA; and oversight of
the construction and operation of pipeline facilities at U.S. points of
entry for the import or export of natural gas. FERC has no jurisdiction
over construction or maintenance of production wells, oil pipelines,
refineries, or storage facilities. More detailed information can be
found at FERC's website: https://www.ferc.gov/.
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    \113\ https://www.ferc.gov/industries-data/natural-gas.
    \114\ https://www.ferc.gov/industries-data/oil.
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B. Industry and Voluntary Actions To Address Climate Change

    Separate from regulatory requirements, some owners or operators of
facilities in the Oil and Natural Gas Industry choose to participate in
voluntary initiatives. Specifically, over 100 oil and natural gas
companies participate in the EPA Natural Gas STAR and Methane Challenge
partnership programs. Owners or operators also participate in a growing
number of voluntary programs unaffiliated with the EPA voluntary
programs. The EPA is aware of at least 19 such initiatives.\115\ Firms
might participate in voluntary environmental programs for a variety of
reasons, including attracting customers, employees, and investors who
value more environmental-responsible goods and services; finding
approaches to improve efficiency and reduce costs; and preparing for or
helping inform future regulations.\116\ \117\
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    \115\ Highwood Emissions Management (2021). ``Voluntary
Emissions Reduction Initiatives for Responsibly Sourced Oil and
Gas.'' Available for download at: https://highwoodemissions.com/research/.
    \116\ Borck, J.C. and C. Coglianese (2009). ``Voluntary
Environmental Programs: Assessing Their Effectiveness.'' Annual
Review of Environment and Resources 34(1): 305-324.
    \117\ Brouhle, K., C. Griffiths, and A. Wolverton. (2009).
``Evaluating the role of EPA policy levers: An examination of a
voluntary program and regulatory threat in the metal-finishing
industry.'' Journal of Environmental Economics and Management.
57(2): 166-181.
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    The EPA's Natural Gas STAR Program started in 1993 and seeks to
achieve methane emission reductions through implementation of cost-
effective best practices and technologies. Partner companies document
their voluntary emission reduction activities and can report their
accomplishments to the EPA annually. Natural Gas STAR includes over 90
partners across the natural gas value chain. Through 2019 partner
companies report having eliminated nearly 1.7 trillion cubic feet of
methane emissions since 1993.
    The EPA's Methane Challenge Program was launched in 2016 and
expands on the Natural Gas STAR Program with ambitious, quantifiable
commitments and detailed, transparent reporting and partner
recognition. Annually Methane Challenge partners submit facility-level
reports that characterize the methane emission sources at their
facilities and detail voluntary actions taken to reduce methane
emissions. The EPA emphasizes the importance of transparency with the
publication of these facility-level data. Although this program
includes nearly 70 companies from all segments of the industry, most
partners operate in the transmission and distribution segments.
    Other voluntary programs for the oil and natural gas industry are
administered by diverse organizations, including trade associations and
non-profits. While the field of voluntary initiatives continues to
grow, it is difficult to understand the present, and potential future,
impact these initiatives will have on reducing methane emissions as the
majority of these initiatives publish aggregated program-level data.
The EPA recognizes the voluntary efforts of industry in reducing
methane emissions beyond what is required by current regulations and in
significantly expanding the understanding of methane mitigation
measures. While progress has been made, there is still considerable
remaining need to further reduce methane emissions from the Industry.

VI. Environmental Justice Considerations, Implications, and Stakeholder
Outreach

    To better inform this proposed rulemaking, the EPA assessed the
characteristics of populations living near sources affected by the rule
and conducted extensive outreach to overburdened and underserved
communities and to environmental justice organizations. During our
engagement with communities, concerns were raised regarding health
effects of air pollutants, implications of climate change on lifestyle
changes, water quality, or extreme heat events, and accessibility to
data and information regarding sources near their homes. The EPA then
considered this input along with other stakeholder input in designing
the proposed rule. For example, one key issue identified through
stakeholder input is the use of cutting-edge technologies for methane
detection that can allow for rapid detection of high-emitting sources.
As described below, the EPA is proposing to allow the use of such
technologies in this rule, alongside a rigorous fugitive emissions
monitoring program that is based on traditional OGI technology. Another
key concern the Agency heard is addressing large emission sources
faster, which, in addition to seeking more information on new detection
technologies, the EPA is proposing to address with more frequent
monitoring at sites with more emissions. The EPA also heard that
adjacent communities are concerned about health impacts, and the EPA is
proposing rigorous guidelines for pollution sources at existing
facilities, methane standards for storage vessels, strengthened and
expanded standards for pneumatic controllers, and standards for liquids
unloading events that will further reduce emissions of those
pollutants. These are just a few examples of how this proposed rule
provides benefits to communities; section XII provides a full
explanation and rationale of the proposed actions.
    E.O. 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 FR 7629 (February 16, 1994). Additionally, E.O.
13985 was signed in 2021 to advance racial equity and support
underserved communities--including people of color and others who have
been historically underserved, marginalized, and adversely affected by
persistent poverty and inequality--through Federal Government actions.
86 FR 7009 (January 20, 2021). With respect to climate change, E.O.
14008, titled ``Tackling Climate Change at Home and Abroad,'' was
signed on January 27, 2021, stating that climate considerations shall
be an essential element of United States foreign policy and national
security, working in partnership with foreign governments, States,
territories, and local governments, and communities potentially
impacted by climate change. 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'' (https://www.epa.gov/environmentaljustice). 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
emitted from sources within the Oil and Natural Gas Industry that are
addressed in this proposed rulemaking.

A. Environmental Justice and the Impacts of Climate Change

    In 2009, under the Endangerment and Cause or Contribute Findings
for Greenhouse Gases Under Section 202(a) of the Clean Air Act
(``Endangerment Finding'', 74 FR 66496), the Administrator considered
how climate change threatens the health and welfare of the U.S.
population.\118\ As part of that consideration, she also considered
risks to minority and low-income individuals and communities, finding
that certain parts of the U.S. population may be especially vulnerable
based on their characteristics or circumstances. These groups include
economically and socially disadvantaged communities, including those
that have been historically marginalized or overburdened; individuals
at vulnerable lifestages, such as the elderly, the very young, and
pregnant or nursing women; those already in poor health or with
comorbidities; the disabled; those experiencing homelessness, mental
illness, or substance abuse; and/or Indigenous or minority populations
dependent on one or limited resources for subsistence due to factors
including but not limited to geography, access, and mobility.
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    \118\ Earlier studies and reports can be found at https://www.epa.gov/cira/social-vulnerability-report.
---------------------------------------------------------------------------

    Scientific assessment reports produced over the past decade by the
USGCRP,\119\ \120\ the IPCC,\121\ \122\ \123\ \124\ the National
Academies of Science, Engineering, and Medicine,\125\ \126\ and the EPA
\127\ add more evidence that the impacts of climate change raise
potential EJ concerns. These reports conclude that less-affluent,
traditionally marginalized and predominantly non-White communities can
be especially vulnerable to climate change impacts because they tend to
have limited resources for adaptation, are more dependent on climate-
sensitive resources such as local water and food supplies, or have less
access to social and information resources. Some communities of color,
specifically populations defined jointly by ethnic/racial
characteristics and geographic location (e.g., African-American, Black,
and Hispanic/Latino communities; Native Americans, particularly those
living on Tribal lands and Alaska Natives), may be uniquely vulnerable
to climate change health impacts in the U.S., as discussed below. In
particular, the 2016 scientific assessment on the Impacts of Climate
Change on Human Health \128\ found with high confidence that
vulnerabilities are place- and time-specific, lifestages and ages are
linked to immediate and future health impacts, and social determinants
of health are linked to greater extent and severity of climate change-
related health impacts.
---------------------------------------------------------------------------

    \119\ USGCRP, 2018: Impacts, Risks, and Adaptation in the United
States: Fourth National Climate Assessment, Volume II [Reidmiller,
D.R., C.W. Avery, D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K.
Maycock, and B.C. Stewart (eds.)]. U.S. Global Change Research
Program, Washington, DC, USA, 1515 pp. doi: 10.7930/NCA4.2018.
    \120\ USGCRP, 2016: The Impacts of Climate Change on Human
Health in the United States: A Scientific Assessment. Crimmins, A.,
J. Balbus, J.L. Gamble, C.B. Beard, J.E. Bell, D. Dodgen, R.J.
Eisen, N. Fann, M.D. Hawkins, S.C. Herring, L. Jantarasami, D.M.
Mills, S. Saha, M.C. Sarofim, J. Trtanj, and L. Ziska, Eds. U.S.
Global Change Research Program, Washington, DC, 312 pp. http://dx.doi.org/10.7930/J0R49NQX.
    \121\ Oppenheimer, M., M. Campos, R. Warren, J. Birkmann, G.
Luber, B. O'Neill, and K. Takahashi, 2014: Emergent risks and key
vulnerabilities. In: Climate Change 2014: Impacts, Adaptation, and
Vulnerability. Part A: Global and Sectoral Aspects. Contribution of
Working Group II to the Fifth Assessment Report of the
Intergovernmental Panel on Climate Change [Field, C.B., V.R. Barros,
D.J. Dokken, K.J. Mach, M.D. Mastrandrea, T.E. Bilir, M. Chatterjee,
K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N.
Levy, S. MacCracken, P.R. Mastrandrea, and L.L. White (eds.)].
Cambridge University Press, Cambridge, United Kingdom and New York,
NY, USA, pp. 1039-1099.
    \122\ Porter, J.R., L. Xie, A.J. Challinor, K. Cochrane, S.M.
Howden, M.M. Iqbal, D.B. Lobell, and M.I. Travasso, 2014: Food
security and food production systems. In: Climate Change 2014:
Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral
Aspects. Contribution of Working Group II to the Fifth Assessment
Report of the Intergovernmental Panel on Climate Change [Field,
C.B., V.R. Barros, D.J. Dokken, K.J. Mach, M.D. Mastrandrea, T.E.
Bilir, M. Chatterjee, K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma,
E.S. Kissel, A.N. Levy, S. MacCracken, P.R. Mastrandrea, and L.L.
White (eds.)]. Cambridge University Press, Cambridge, United Kingdom
and New York, NY, USA, pp. 485-533.
    \123\ Smith, K.R., A. Woodward, D. Campbell-Lendrum, D.D.
Chadee, Y. Honda, Q. Liu, J.M. Olwoch, B. Revich, and R. Sauerborn,
2014: Human health: impacts, adaptation, and co-benefits. In:
Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A:
Global and Sectoral Aspects. Contribution of Working Group II to the
Fifth Assessment Report of the Intergovernmental Panel on Climate
Change [Field, C.B., V.R. Barros, D.J. Dokken, K.J. Mach, M.D.
Mastrandrea, T.E. Bilir, M. Chatterjee, K.L. Ebi, Y.O. Estrada, R.C.
Genova, B. Girma, E.S. Kissel, A.N. Levy, S. MacCracken, P.R.
Mastrandrea, and L.L. White (eds.)]. Cambridge University Press,
Cambridge, United Kingdom and New York, NY, USA, pp. 709-754.
    \124\ IPCC, 2018: Global Warming of 1.5 [deg]C. An IPCC Special
Report on the impacts of global warming of 1.5 [deg]C above pre-
industrial levels and related global greenhouse gas emission
pathways, in the context of strengthening the global response to the
threat of climate change, sustainable development, and efforts to
eradicate poverty [Masson-Delmotte, V., P. Zhai, H.-O. P[ouml]rtner,
D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C.
P[eacute]an, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X.
Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, and T.
Waterfield (eds.)]. In Press.
    \125\ National Research Council. 2011. America's Climate
Choices. Washington, DC: The National Academies Press. https://doi.org/10.17226/12781.
    \126\ National Academies of Sciences, Engineering, and Medicine.
2017. Communities in Action: Pathways to Health Equity. Washington,
DC: The National Academies Press. https://doi.org/10.17226/24624.
    \127\ EPA. 2021. Climate Change and Social Vulnerability in the
United States: A Focus on Six Impacts. U.S. Environmental Protection
Agency, EPA 430-R-21-003.
    \128\ USGCRP, 2016: The Impacts of Climate Change on Human
Health in the United States: A Scientific Assessment.
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    Per the NCA4, ``Climate change affects human health by altering
exposures to heat waves, floods, droughts, and other extreme events;
vector-, food- and waterborne infectious diseases; changes in the
quality and safety of air, food, and water; and stresses to mental
health and well-being.'' \129\ Many health conditions such as
cardiopulmonary or respiratory illness and other health impacts are
associated with and exacerbated by an increase in GHGs and climate
change outcomes, which is problematic as these diseases occur at higher
rates within vulnerable communities. Importantly, negative public
health outcomes include those that are physical in nature, as well as
mental, emotional, social, and economic.
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    \129\ Ebi, K.L., J.M. Balbus, G. Luber, A. Bole, A. Crimmins, G.
Glass, S. Saha, M.M. Shimamoto, J. Trtanj, and J.L. White-Newsome,
2018: Human Health. In Impacts, Risks, and Adaptation in the United
States: Fourth National Climate Assessment, Volume II [Reidmiller,
D.R., C.W. Avery, D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K.
Maycock, and B.C. Stewart (eds.)]. U.S. Global Change Research
Program, Washington, DC, USA, pp. 539-571. doi: 10.7930/
NCA4.2018.CH14.
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    The scientific assessment literature, including the aforementioned
reports, demonstrates that there are myriad ways

in which these populations may be affected at the individual and
community levels. Outdoor workers, such as construction or utility
workers and agricultural laborers, who are frequently part of already
at-risk groups, are exposed to poor air quality and extreme