Proposed Rule2022-27603
Air Plan Approval; Texas; Reasonable Further Progress Plan for the Dallas-Fort Worth Ozone Nonattainment Area
Primary source
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Published
December 20, 2022
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is supplementing a proposed approval published on October 9, 2020 ("October 2020 proposal"), for revisions to the Texas State Implementation Plan (SIP) to meet the Reasonable Further Progress (RFP) requirements for the Dallas-Fort Worth (DFW) serious nonattainment area for the 2008 ozone National Ambient Air Quality Standard (NAAQS). This proposal supplements the EPA's October 2020 proposal with respect to the substitution of emission reductions of nitrogen oxide (NO<INF>X</INF>) for emission reductions of volatile organic compounds (VOC), based on comments received during the public comment period for the October 2020 proposal. In the October 2020 proposal, the EPA proposed to approve the substitution of NO<INF>X</INF> emission reductions for VOC emission reductions but did not address how the substitution is consistent with the Clean Air Act (CAA). In this supplemental proposal, EPA is proposing to approve the substitution of NO<INF>X</INF> emission reductions for VOC emission reductions as consistent with section 182(c)(2)(C) of the CAA. The EPA is providing an opportunity for public comment on this supplemental proposal. The EPA is not reopening for comment the October 2020 proposal. Comments received on the October 2020 proposal and this supplemental proposal will be addressed in a final rule.
Full Text
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<title>Federal Register, Volume 87 Issue 243 (Tuesday, December 20, 2022)</title>
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[Federal Register Volume 87, Number 243 (Tuesday, December 20, 2022)]
[Proposed Rules]
[Pages 77770-77774]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-27603]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R06-OAR-2020-0161; FRL-10428-01-R6]
Air Plan Approval; Texas; Reasonable Further Progress Plan for
the Dallas-Fort Worth Ozone Nonattainment Area
AGENCY: Environmental Protection Agency (EPA).
ACTION: Supplemental notice of proposed rulemaking.
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SUMMARY: The Environmental Protection Agency (EPA) is supplementing a
proposed approval published on October 9, 2020 (``October 2020
proposal''), for revisions to the Texas State Implementation Plan (SIP)
to meet the Reasonable Further Progress (RFP) requirements for the
Dallas-Fort Worth (DFW) serious nonattainment area for the 2008 ozone
National Ambient Air Quality Standard (NAAQS). This proposal
supplements the EPA's October 2020 proposal with respect to the
substitution of emission reductions of nitrogen oxide (NO<INF>X</INF>)
for emission reductions of volatile organic compounds (VOC), based on
comments received during the public comment period for the October 2020
proposal. In the October 2020 proposal, the EPA proposed to approve the
substitution of NO<INF>X</INF> emission reductions for VOC emission
reductions but did not address how the substitution is consistent with
the Clean Air Act (CAA). In this supplemental proposal, EPA is
proposing to approve the substitution of NO<INF>X</INF> emission
reductions for VOC emission reductions as consistent with section
182(c)(2)(C) of the CAA. The EPA is providing an opportunity for public
comment on this supplemental proposal. The EPA is not reopening for
comment the October 2020 proposal. Comments received on the October
2020 proposal and this supplemental proposal will be addressed in a
final rule.
DATES: Written comments on this supplemental proposal must be received
on or before January 19, 2023.
ADDRESSES: Submit your comments, identified by Docket No. EPA-R06-OAR-
2020-0161, at <a href="https://www.regulations.gov">https://www.regulations.gov</a> or via email to
<a href="/cdn-cgi/l/email-protection#7e0e1f17191b501d1f0c0c171b3e1b0e1f50191108"><span class="__cf_email__" data-cfemail="0e7e6f67696b206d6f7c7c676b4e6b7e6f20696178">[email protected]</span></a>. Follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
<a href="http://Regulations.gov">Regulations.gov</a>. The EPA may publish any comment received to its public
docket. Do not submit electronically any information you consider to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Multimedia submissions (audio,
video, etc.) must be accompanied by a written comment. The written
comment is considered the official comment and should include
discussion of all points you wish to make. The EPA will generally not
consider comments or comment contents located outside of the primary
submission (i.e., on the web, cloud, or other file sharing system). For
additional submission methods, please contact Carrie Paige, 214-665-
6521, <a href="/cdn-cgi/l/email-protection#1767767e707239747665657e725772677639707861"><span class="__cf_email__" data-cfemail="99e9f8f0fefcb7faf8ebebf0fcd9fce9f8b7fef6ef">[email protected]</span></a>. For the full EPA public comment policy,
information about CBI or multimedia submissions, and general guidance
on making effective comments, please visit <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.
Docket: The index to the docket for this action is available
electronically at <a href="http://www.regulations.gov">www.regulations.gov</a>. While all documents in the
docket are listed in the index, some information may not be publicly
available due to docket file size restrictions or content (e.g., CBI).
FOR FURTHER INFORMATION CONTACT: Carrie Paige, EPA Region 6 Office,
Infrastructure & Ozone Section, 214-
[[Page 77771]]
665-6521, <a href="/cdn-cgi/l/email-protection#f484959d9391da979586869d91b4918495da939b82"><span class="__cf_email__" data-cfemail="5525343c32307b363427273c30153025347b323a23">[email protected]</span></a>. Out of an abundance of caution for
members of the public and our staff, the EPA Region 6 office may be
closed to the public to reduce the risk of transmitting COVID-19. The
EPA Region 6 office encourages the public to submit comments via
<a href="https://www.regulations.gov">https://www.regulations.gov</a>. Please call or email the contact listed
above if you need alternative access to material indexed but not
provided in the docket.
SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us,''
and ``our'' refers to the EPA.
I. Background
On May 13, 2020, the Texas Commission on Environmental Quality
(TCEQ or State) submitted to EPA a SIP revision addressing RFP
requirements for the 2008 8-hour ozone NAAQS for the two serious ozone
nonattainment areas in Texas--the DFW and Houston-Galveston-Brazoria
(HGB) areas. On October 9, 2020 (85 FR 64084), we published a proposed
rule to approve those portions of the May 13, 2020, Texas SIP revision
addressing the DFW RFP requirements.\1\ In this supplemental proposal,
we refer to the May 13, 2020, Texas SIP revision as ``the RFP
submittal'' and we refer to our October 9, 2020, proposed action and
Technical Support Document (TSD) as ``the October 2020 proposal.'' \2\
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\1\ We addressed the RFP for the HGB serious ozone nonattainment
area in a separate rulemaking. See 86 FR 24717 (May 10, 2021).
\2\ The RFP submittal and our October 2020 proposal are provided
in the docket for this action.
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In our October 2020 proposal, we provided information on ozone
formation, the ozone standards, area designations, related SIP revision
requirements under the CAA, and the EPA's implementing regulations for
the 2008 ozone standards, referred to as the 2008 Ozone SIP
Requirements Rule (``2008 Ozone SRR'').\3\ The DFW Area, comprising
Collin, Dallas, Denton, Ellis, Johnson, Kaufman, Parker, Rockwall,
Tarrant, and Wise counties was classified as Serious nonattainment for
the 2008 ozone standards and as such was subject to the serious area
requirements, one of which was to demonstrate reasonable further
progress in reducing VOC.\4\ In demonstrating RFP, NO<INF>X</INF>
emission reductions may be substituted for VOC reductions with the
appropriate justification.
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\3\ See 80 FR 12264 (March 6, 2015).
\4\ The EPA's recent final determination that the DFW Serious
nonattainment area failed to attain the 2008 ozone NAAQS by the
area's attainment date is outside the scope of this action. 87 FR
60926 (October 7, 2022).
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Comments on our October 2020 proposal were required to be received
by November 9, 2020. We received relevant adverse comments on our
proposal that included, among other comments, that our proposal did not
address how the substitution of NO<INF>X</INF> emission reductions for
VOC emission reductions in the DFW RFP is consistent with the CAA.
Thus, we are addressing the NO<INF>X</INF> substitution in this
supplemental proposal action. All comments received on our October 2020
proposal and this supplemental proposal will be addressed in the final
action.
A. An Overview of Ozone Chemistry and NO<INF>X</INF> Substitution
Effects
As explained in our October 2020 proposal, ground-level ozone is
formed when VOC and NO<INF>X</INF> react in the presence of
sunlight.\5\ However, rather than varying directly with emissions of
its precursors, ozone changes in a nonlinear fashion with the
concentrations of its precursors. As described in EPA's Health Risk and
Exposure Assessment for Ozone,\6\ NO<INF>X</INF> emissions lead to both
the formation and destruction of ozone, depending on the local
concentrations of NO<INF>X</INF>, VOC, and radicals such as the
hydroxyl (OH) and hydroperoxy (HO<INF>2</INF>) radicals. In areas
dominated by fresh emissions of NO<INF>X</INF>, these radicals are
removed via the production of nitric acid (HNO<INF>3</INF>), which
lowers the ozone formation rate. In addition, the depletion of ozone by
reaction with NO<INF>X</INF> is called ``titration'' and is often found
in downtown metropolitan areas, especially near busy streets and roads,
and in power plant emission plumes.\7\ This ``titration'' results in
ozone concentrations that can be much lower than in surrounding areas.
Titration is usually confined to areas close to strong NO<INF>X</INF>
sources, and the NO<INF>2</INF> formed can lead to ozone formation
later and further downwind. Consequently, ozone response to reductions
in NO<INF>X</INF> emissions is complex and may include ozone decreases
at some times and locations and increases in ozone at other times and
locations. In areas with low NO<INF>X</INF> concentrations, such as
those found in remote continental areas and rural and suburban areas
downwind of urban centers, the net production of ozone typically varies
directly with NO<INF>X</INF> concentrations and increases with
increasing NO<INF>X</INF> emissions.
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\5\ VOC and NO<INF>X</INF> are also referred to as ozone
precursors.
\6\ EPA, Health Risk and Exposure Assessment (HREA) for Ozone
Final Report, August 2014. Available at <a href="https://www.epa.gov/naaqs/ozone-o3-standards-risk-and-exposure-assessments-review-completed-2015">https://www.epa.gov/naaqs/ozone-o3-standards-risk-and-exposure-assessments-review-completed-2015</a>.
\7\ Oxides of nitrogen (NO<INF>X</INF>) can be in the form of
nitric oxide (NO), nitrite (NO<INF>2</INF>), etc. Ozone
(O<INF>3</INF>) is a highly reactive gas that decays to ordinary
oxygen (O<INF>2</INF>). When O<INF>3</INF> reacts with
NO<INF>X</INF>, the result oxidizes the NO<INF>X</INF>, i.e., the
molecule of oxygen (O) moves from the O<INF>3</INF> to the
NO<INF>X</INF>. For example, O<INF>3</INF> + NO forms NO<INF>2</INF>
+ O<INF>2</INF>. This reaction can also move in the opposite
direction, to form ozone.
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In general, the rate of ozone production is limited by either the
concentration of VOC or NO<INF>X</INF>. Ozone formation resulting from
these two precursors relies on the relative sources of OH and
NO<INF>X</INF>. When OH radicals are abundant and are not depleted by
reaction with NO<INF>X</INF> and/or other species, ozone production is
referred to as being ``NO<INF>X</INF>-limited.'' \8\ In this situation,
ozone concentrations are most effectively reduced by lowering
NO<INF>X</INF> emissions, rather than lowering emissions of VOCs. When
the abundance of OH and other radicals is limited either through low
production or reactions with NO<INF>X</INF> and other species, ozone
production is sometimes called ``VOC-limited'' or ``NO<INF>X</INF>-
saturated'' and ozone is most effectively reduced by lowering VOCs.
However, even in NO<INF>X</INF>-saturated conditions, very large
decreases in NO<INF>X</INF> emissions can cause the ozone formation
regime to become NO<INF>X</INF>-limited. Consequently, reductions in
NO<INF>X</INF> emissions (when large), can make further emissions
reductions more effective at reducing ozone. Between the
NO<INF>X</INF>-limited and NO<INF>X</INF>-saturated extremes there is a
transitional region, where ozone is less sensitive to marginal changes
in either NO<INF>X</INF> or VOCs. In rural areas and downwind of urban
areas, ozone production is generally NO<INF>X</INF>-limited. However,
across urban areas with high populations, conditions may vary.
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\8\ See EPA's Integrated Science Assessment (ISA) for Ozone and
Related Photochemical Oxidants, Final Report, February 2013, section
3.2.4, posted at <a href="https://www.epa.gov/naaqs/ozone-o3-standards-integrated-science-assessments-review-completed-2015">https://www.epa.gov/naaqs/ozone-o3-standards-integrated-science-assessments-review-completed-2015</a>.
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CAA section 182(c)(2)(C) requires serious and above ozone
nonattainment areas to make reasonable progress in reducing VOC, and
also grants the EPA discretion to define the conditions under which
NO<INF>X</INF> reductions may be substituted for or combined with VOC
reductions ``in order to maximize the reduction in ozone air
pollution'' and does not further specify the conditions that represent
an ``equivalent'' reduction in ozone. For instance, it does not require
a specific concentration test at every monitor or at specific locations
within an area. No such requirement appears in the CAA's other
provisions governing the RFP demonstration, which define specific
percentage reductions aimed at ensuring timely attainment of the NAAQS,
or in the
[[Page 77772]]
EPA's 1993 NO<INF>X</INF> Substitution Guidance, which describes a
recommended procedure for states to utilize NO<INF>X</INF>
substitution.\9\ We interpret CAA section 182(c)(2)(C) and these
supporting authorities as properly reflecting Congress's intent to
allow NO<INF>X</INF> reductions to be considered within an RFP
demonstration so long as these reductions are at least as effective as
using VOC reductions in reducing ozone.
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\9\ EPA's NO<INF>X</INF> Substitution Guidance is posted in the
docket for this rulemaking and at <a href="https://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2_old/19931201_oaqps_nox_substitution_guidance.pdf">https://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2_old/19931201_oaqps_nox_substitution_guidance.pdf</a>.
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B. Ozone Chemistry in the DFW Area
The dynamics of ozone formation in the DFW area, including the
proportion of VOC to NO<INF>X</INF> (``VOC: NO<INF>X</INF> ratio''),
are described in Appendix D of the DFW Serious Area Attainment
Demonstration SIP Revision for the 2008 Ozone NAAQS.\10\ Appendix D is
the conceptual model for the DFW area, providing details on ozone
transport, as well as trends and formation.
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\10\ Henceforth referred to as ``Appendix D'' and posted in the
docket for this action.
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The highest levels of ozone typically occur north and northwest of
the Dallas urban core, e.g., at the Denton Airport South and Grapevine
Fairway monitors -- these monitors are often downwind during the ozone
season, as surface winds during this time are predominately from the
south and southeast.\11\ The Grapevine Fairway monitor, northwest of
the Dallas urban core, was the ``controlling'' monitor in 2018 and
2020; the Dallas North monitor, north of the Dallas urban core, was the
controlling monitor in 2019; and the Pilot Point monitor, north-
northwest of the Dallas urban core, was the controlling monitor in
2021.\12\ The controlling monitor is the monitor with the highest ozone
design value (DV) in the nonattainment area. The DV is the annual
fourth highest daily maximum 8-hour average ozone concentration and is
the metric to determine compliance with the 2008 ozone NAAQS. Thus, the
controlling monitor determines the ozone DV for the nonattainment area.
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\11\ A map showing the location of the 20 ozone monitors in the
DFW area is posted in the docket for this action.
\12\ The TCEQ posts the annual fourth highest daily maximum 8-
hour average ozone concentrations. See <a href="https://www.tceq.texas.gov/cgi-bin/compliance/monops/8hr_attainment.pl">https://www.tceq.texas.gov/cgi-bin/compliance/monops/8hr_attainment.pl</a>.
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The DFW area is the fourth largest metropolitan area in the United
States with about 7.5 million residents.\13\ Ozone precursor emissions
(both NO<INF>X</INF> and VOC) in the DFW area and particularly the
urban core of Dallas and Fort Worth have historically been dominated by
mobile source emissions.\14\ In recent years however, only the
NO<INF>X</INF> emissions in the DFW area are dominated by mobile
sources and VOC emissions are dominated by area sources.\15\ Appendix D
mentions that the highest average NO<INF>X</INF> concentrations have
been measured at the Dallas Hinton Street ozone monitor, located in the
Dallas urban core near several busy roadways. Monitors located to the
south and southeast of Dallas County, in areas that are relatively
rural, have measured the lowest NO<INF>X</INF> concentrations.
NO<INF>X</INF> concentrations in the DFW area have declined since the
mid-1980s and NO<INF>X</INF> concentrations at the Dallas Hinton Street
monitor showed a 50 percent (%) decrease from 2003 through 2013. We
believe that NO<INF>X</INF> emissions have continued to decrease since
2013, as seen in the more recent and lower emission inventories for the
DFW area cited earlier (81 FR 88124 and 87 FR 56891). Appendix D
mentions that reductions in NO<INF>X</INF> concentrations outside the
DFW urban core are not as large as those observed close to its center,
which suggests that the measured decreases may be a result of
reductions in NO<INF>X</INF> emissions from mobile sources. Decreases
in VOC concentration have also been measured in the DFW area but are
not as dramatic as the decreases in NO<INF>X</INF> emissions.
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\13\ U.S. Census Bureau, 2020 census data for the 10 counties
comprising the DFW area. See <a href="https://www.census.gov/library/visualizations/interactive/2020-population-and-housing-state-data.html">https://www.census.gov/library/visualizations/interactive/2020-population-and-housing-state-data.html</a>.
\14\ For example, see the approved emission inventories at 73 FR
58475 (October 7, 2008).
\15\ See the emission inventories approved at 79 FR 67068
(November 12, 2014), 81 FR 88124 (December 7, 2016), and 87 FR 56891
(September 16, 2022).
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The TCEQ uses analyses in Appendix D to conclude that monitors to
the northwest and on the edges of the DFW area are transitional or
NO<INF>X</INF>-limited, indicating that NO<INF>X</INF> controls would
be more effective at controlling ozone in these areas. Monitors to the
northwest include the Denton Airport South, Grapevine Fairway, Keller,
and Eagle Mountain Lake, and monitors on the edges of the DFW area
include Pilot Point, Parker County, Granbury, Cleburne Airport, Italy,
Corsicana Airport, Kaufman, Rockwall Heath, and Greenville. Of these
monitors, only the Grapevine Fairway, Pilot Point, and Cleburne Airport
monitors had ozone DVs above 75 ppb from 2018 through 2021.
Of the 20 ozone monitors in the DFW area, 15 have ozone DVs at or
below 75 ppb from 2018 through 2021 and thus, are not relevant to the
discussion on NO<INF>X</INF> substitution since these monitors are not
violating the 2008 ozone NAAQS. Four of the five monitors with ozone
DVs above 75 ppb (Frisco, Dallas North, Grapevine Fairway, and Pilot
Point) are north and northwest (and typically downwind) from the Dallas
urban core and thus, consistent with our earlier discussion on ozone
chemistry and the TCEQ's analyses in Appendix D, we would expect
NO<INF>X</INF> controls to be more effective than VOC controls for
reducing ozone at these monitors. The fifth monitor with ozone DVs
above 75 ppb is the Cleburne Airport monitor, which, as noted earlier,
is on the edge of the DFW area and is south-southwest of the DFW urban
core. While surface winds during the ozone season are predominately
from the south and southeast, it is not unusual for surface winds to
flow from the northeast (and thus, flow downwind from the DFW urban
core) on days when the Cleburne Airport monitor exceeds the ozone
standard.\16\ Therefore, consistent with our earlier discussion on
ozone chemistry and the TCEQ's analyses in Appendix D, we would expect
NO<INF>X</INF> controls to be more effective than VOC controls for
controlling ozone at this monitor, too.
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\16\ See the 2014-2016 back trajectory analyses from the
Cleburne Airport monitor provided in the Dallas-Fort Worth and
Houston-Galveston-Brazoria Nonattainment Areas Final Area
Designations for the 2015 Ozone National Ambient Air Quality
Standards Technical Support Document, Figure 6b on page 18. Figure
6b shows winds predominantly from the northeast on days when the
Cleburne Airport monitor exceeded the 2015 ozone NAAQS. This TSD is
posted at <a href="https://www.regulations.gov/document/EPA-HQ-OAR-2017-0548-0403">https://www.regulations.gov/document/EPA-HQ-OAR-2017-0548-0403</a>.
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A new analysis published by EPA authors looks at ozone formation
regimes in 2007 and 2016 in ozone nonattainment areas, including the
DFW area.\17\ Details for DFW are included in the supplemental
information of that paper which suggests that: (1) day-of-week analysis
points to the DFW area as a whole being NO<INF>X</INF>-limited in 2016
but the controlling monitor being ``transitional,'' and (2)
photochemical model sensitivity analysis (i.e., model predictions of
how ozone will change with emissions perturbations) predicts that in
2016 all locations in the DFW area were NO<INF>X</INF>-limited on
average across days with ozone levels above 70 ppb (there could be some
variability among those days). The controlling monitor in 2016 was the
Denton Airport South monitor, northwest of the Dallas
[[Page 77773]]
urban core, with an ozone DV of 80 ppb.\18\
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\17\ Reference: Koplitz, S; Simon, H; Henderson, B; Liljegren,
J; Tonnesen, G; Whitehill, A; and Wells, B. Changes in Ozone
Chemical Sensitivity in the United States from 2007 to 2016. ACS
Environ. Au 2022, 2, 206-222. See also <a href="https://doi.org/10.1021/acsenvironau.1c00029">https://doi.org/10.1021/acsenvironau.1c00029</a>. This article and the supplemental information
are in the docket for this action.
\18\ The ozone DV at the Denton Airport South monitor was at or
below 75 ppb from 2018 through 2021.
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An analysis of ozone and NO<INF>X</INF> for each day of the week
for 1997-2013 is also provided in Appendix D. In the scientific
literature, day-of-week analysis has been used to infer ozone chemical
regimes.\19\ In many urban areas, NO<INF>X</INF> concentrations
decrease on weekends while VOC concentrations remain fairly constant
due to shifts in heavy-duty diesel vehicle patterns throughout the
week. All other conditions being equal, if ozone concentrations
decrease in parallel with these lower weekend NO<INF>X</INF> values
that suggests a location has NO<INF>X</INF>-limited ozone formation
regime. Conversely higher weekend ozone concentrations suggest a VOC-
limited ozone formation regime. The analysis presented in Appendix D
finds that on Sundays, ozone and NO<INF>X</INF> concentrations were
significantly lower compared to other days of the week and on Fridays,
ozone and NO<INF>X</INF> concentrations were higher compared to other
days of the week. Appendix D notes that the highest NO<INF>X</INF>
concentrations (on Fridays) are also when traffic (on-road mobile
source activity) is at its peak. Appendix D further presents site-level
ozone concentrations by day-of-week and shows that the highest ozone
concentrations occur mid-week at both an urban core site (Dallas Hinton
Street) and at one of the controlling monitors (Grapevine Fairway)
suggesting NO<INF>X</INF>-limited conditions in these locations. The
analysis in Appendix D reviewed the number of days with ozone
concentrations greater than 75 ppb (``high ozone days'') for each day
of the week at all monitoring sites in the DFW area and found that
fewer high ozone days occur on Sundays compared to other days of the
week. Sunday had 85 high ozone days and Monday had the second lowest
number of high ozone days--103. High ozone days occur most often on
Fridays, with 137 days. While the day-of-week analysis is for years
1997-2013, NO<INF>X</INF> reductions in the DFW area since 2013 are
expected to result in more NO<INF>X</INF>-limited conditions than would
have been present during the period of this analysis.
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\19\ Please see the list of references provided in the docket
for this action.
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From 2018 through 2021, 15 of the 20 monitors in the DFW area
recorded ozone DVs at or below 75 ppb and five monitors had ozone DVs
above 75 ppb: Pilot Point, Grapevine Fairway, Dallas North, Frisco, and
Cleburne Airport. The TCEQ's analyses in Appendix D indicate that
NO<INF>X</INF> controls would be more effective at controlling ozone in
these monitor locations. The TCEQ's findings here are consistent with
our understanding of ozone chemistry and recent analysis of ozone
formation regimes described earlier. Therefore, we find the TCEQ's use
of NO<INF>X</INF> substitution in the DFW area reasonable, especially
where the DFW monitors have DVs above 75 ppb from 2018 through 2021.
II. NO<INF>X</INF> Substitution in the TX RFP SIP for the DFW Area
As described here and in our October 2020 proposal, the DFW serious
nonattainment area for the 2008 ozone NAAQS had an attainment date of
July 20, 2021.\20\ The attainment year ozone season is the ozone season
immediately preceding a nonattainment area's maximum attainment date
(see 40 CFR 51.1100(h)). Therefore, pursuant to CAA section 182(c)(2)
and 40 CFR 51.1110, the RFP submittal for the DFW serious nonattainment
area must demonstrate emissions reductions within the nonattainment
area of three percent per year from January 1, 2018, to the end of the
attainment year and thus, a nine percent reduction in emissions is
required from January 1, 2018, through December 31, 2020. In addition,
because the State has already satisfied the 15 percent VOC emissions
reduction requirement for the DFW area,\21\ all 10 counties in the DFW
Serious nonattainment area may substitute NO<INF>X</INF> reductions for
VOC, consistent with the 2008 Ozone SRR (see 80 FR 12264, 12271), 40
CFR 51.1110, and EPA's NO<INF>X</INF> Substitution Guidance.
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\20\ See 84 FR 44238, (August 23, 2019). The EPA's final
determination that the DFW area did not meet the July 20, 2021,
attainment date for the 2008 ozone NAAQS is outside the scope of
this action (see 87 FR 60926).
\21\ See 81 FR 88124 (December 7, 2016).
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The RFP submittal for the DFW area provides the required nine
percent reductions as eight percent NO<INF>X</INF> emissions reductions
and one percent VOC emissions reductions. As noted earlier, Appendix D
describes the highest levels of NO<INF>X</INF> in the urban core and
the highest concentrations of ozone recorded at monitors downwind of
the urban core, predominantly in the north and northwest portions of
the DFW area. Appendix D also describes a transitional regime in the
DFW urban core and at the Eagle Mountain Lake monitor however, the
monitors in the DFW urban core and the Eagle Mountain Lake monitor have
ozone DVs at or below 75 ppb from 2018 through 2021 and thus, are not
relevant to the discussion on NO<INF>X</INF> substitution. Appendix D
also describes, consistent with EPA's discussion on ozone chemistry
elsewhere in this action, that monitors to the north, northwest, and on
the edges of the DFW area are transitional or NO<INF>X</INF>-limited.
As mentioned earlier, four of the five monitors that recorded
violations of the 2008 ozone NAAQS between 2018 and 2021 are north and
northwest of the Dallas urban core: Pilot Point, Grapevine Fairway,
Dallas North, and Frisco. The fifth monitor--the Cleburne Airport
monitor--is on the south-southwest edge of the DFW area. Finally, the
State's review of ozone and NO<INF>X</INF> for each day of the week
links levels of NO<INF>X</INF> with ozone levels, indicating that
decreasing levels of NO<INF>X</INF> would result in decreasing levels
of ozone. Because ambient NO<INF>X</INF> and ozone data indicate those
areas of DFW with the highest ozone values are NO<INF>X</INF>-limited,
and because there are no violating monitors in the DFW areas described
as VOC-limited, we agree with Texas that reductions in NO<INF>X</INF>
are at least as effective in reducing ozone as VOC reductions. In
addition, based on the EPA's analysis referenced earlier \22\ and the
TCEQ's day-of-the-week analyses of NO<INF>X</INF> concentrations and
ozone levels, we would also expect NO<INF>X</INF> reductions at the DFW
urban core monitors to be at least as effective in reducing ozone as
VOC reductions. Therefore, we find that the State's use of
NO<INF>X</INF> substitution is warranted and appropriately implemented,
and we propose to approve the NO<INF>X</INF> substitution provided in
the RFP submittal for the DFW serious nonattainment area for the 2008
ozone NAAQS.
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\22\ Koplitz, S; Simon, H; Henderson, B; Liljegren, J; Tonnesen,
G; Whitehill, A; and Wells, B. Changes in Ozone Chemical Sensitivity
in the United States from 2007 to 2016. ACS Environ. Au 2022, 2,
206-222. This article and the supplemental information are in the
docket for this action.
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III. Environmental Justice Considerations
Executive Order 12898 (Federal Actions to Address Environmental
Justice in Minority Populations and Low-Income Populations, 59 FR 7629,
February 16, 1994) directs Federal agencies to identify and address
``disproportionately high and adverse human health or environmental
effects'' of their actions on minority populations and low-income
populations to the greatest extent practicable and permitted by law.
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,
[[Page 77774]]
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.'' \23\ For this proposed action, the EPA
conducted screening analyses using the EJScreen (Version 2.1) tool. We
conducted the analyses for the purpose of providing information to the
public, not as a basis of our proposed action. The EJScreen analysis
reports are available in the docket for this rulemaking. The EPA found,
based on the EJScreen analyses, that this proposed action will not have
disproportionately high or adverse human health or environmental
effects on communities with EJ concerns, as the RFP is an accounting of
ozone precursor emission reductions throughout the 10-county DFW
nonattainment area.
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\23\ See <a href="https://www.epa.gov/environmentaljustice/learn-about-environmental-justice">https://www.epa.gov/environmentaljustice/learn-about-environmental-justice</a>.
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IV. Supplemental Proposed Action
The EPA is supplementing our October 2020 proposal addressing
revisions to the Texas SIP to meet the RFP requirements for the DFW
serious nonattainment area for the 2008 ozone NAAQS. In this
supplemental proposal, we are proposing to approve the substitution of
NO<INF>X</INF> emission reductions for VOC emission reductions as
consistent with section 182(c)(2)(C) of the CAA. The EPA is providing
an opportunity for public comment on this supplemental proposal.
However, we are not reopening for comment our October 2020 proposal.
The EPA will address all comments received on our October 2020 proposal
and on this supplemental proposal in our final action.
V. Statutory and Executive Order Reviews
Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the Act and applicable
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in
reviewing SIP submissions, the EPA's role is to approve state choices,
provided that they meet the criteria of the CAA. Accordingly, this
action merely proposes to approve state law as meeting Federal
requirements and does not impose additional requirements beyond those
imposed by state law. For that reason, this action:
<bullet> Is not a ``significant regulatory action'' subject to
review by the Office of Management and Budget under Executive Orders
12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21,
2011);
<bullet> Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
<bullet> Is certified as not having a significant economic impact
on a substantial number of small entities under the Regulatory
Flexibility Act (5 U.S.C. 601 et seq.);
<bullet> Does not contain any unfunded mandate or significantly or
uniquely affect small governments, as described in the Unfunded
Mandates Reform Act of 1995 (Pub. L. 104-4);
<bullet> Does not have federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
<bullet> Is not an economically significant regulatory action based
on health or safety risks subject to Executive Order 13045 (62 FR
19885, April 23, 1997);
<bullet> Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001);
<bullet> Is not subject to requirements of section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272
note) because application of those requirements would be inconsistent
with the CAA; and
<bullet> Does not provide EPA with the discretionary authority to
address, as appropriate, disproportionate human health or environmental
effects, using practicable and legally permissible methods, under
Executive Order 12898 (59 FR 7629, February 16, 1994).
In addition, the SIP is not approved to apply on any Indian
reservation land or in any other area where EPA or an Indian tribe has
demonstrated that a tribe has jurisdiction. In those areas of Indian
country, the proposed rule does not have tribal implications and will
not impose substantial direct costs on tribal governments or preempt
tribal law as specified by Executive Order 13175 (65 FR 67249, November
9, 2000).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Nitrogen dioxide, Ozone, Volatile organic compounds.
Authority: 42 U.S.C. 7401 et seq.
Dated: December 15, 2022.
Earthea Nance,
Regional Administrator, Region 6.
[FR Doc. 2022-27603 Filed 12-19-22; 8:45 am]
BILLING CODE 6560-50-P
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This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.