Proposed Rule2021-16644
Air Plan Approval; Nevada; Revisions to Clark County Ozone Maintenance Plan
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
August 9, 2021
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is proposing to approve a revision to the State of Nevada's state implementation plan (SIP) for Clark County. The revision consists of an update to certain elements of the maintenance plan for the Clark County air quality planning area for the 1997 8-hour ozone national ambient air quality standards (NAAQS or "standards"), including certain emissions inventories and motor vehicle emissions budgets. The EPA is proposing to approve the SIP revision because the Clark County ozone maintenance plan, as revised, continues to provide for maintenance of the 1997 ozone NAAQS and will not interfere with attainment or reasonable further progress of the other NAAQS, and the motor vehicle emissions budgets meet the applicable transportation conformity requirements.
Full Text
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<title>Federal Register, Volume 86 Issue 150 (Monday, August 9, 2021)</title>
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[Federal Register Volume 86, Number 150 (Monday, August 9, 2021)]
[Proposed Rules]
[Pages 43461-43469]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-16644]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R09-OAR-2021-0368; FRL-8716-01-R9 ]
Air Plan Approval; Nevada; Revisions to Clark County Ozone
Maintenance Plan
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
approve a revision to the State of Nevada's state implementation plan
(SIP) for Clark County. The revision consists of an update to certain
elements of the maintenance plan for the Clark County air quality
planning area for the 1997 8-hour ozone national ambient air quality
standards (NAAQS or ``standards''), including certain emissions
inventories and motor vehicle emissions budgets. The EPA is proposing
to approve the SIP revision because the Clark County ozone maintenance
plan, as revised, continues to provide for maintenance of the 1997
ozone NAAQS and will not interfere with attainment or reasonable
further progress of the other NAAQS, and the motor vehicle emissions
budgets meet the applicable transportation conformity requirements.
DATES: Comments must be received on or before September 8, 2021.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2021-0368, at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. For comments submitted
at <a href="http://Regulations.gov">Regulations.gov</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 the person identified in
the FOR FURTHER INFORMATION CONTACT section. 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>. If you need assistance in a
language other than English or if you are a person with disabilities
who needs a reasonable accommodation at no cost to you, please contact
the person identified in the FOR FURTHER INFORMATION CONTACT section.
FOR FURTHER INFORMATION CONTACT: Karina O'Connor, Air Planning Office
(AIR-2), EPA Region IX, 75 Hawthorne Street, San Francisco, CA 94105;
By phone: (775) 434-8176 or by email at <a href="/cdn-cgi/l/email-protection#92fdf1fdfcfcfde0bcf9f3e0fbfcf3d2f7e2f3bcf5fde4"><span class="__cf_email__" data-cfemail="432c202c2d2d2c316d2822312a2d22032633226d242c35">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us,'' or
``our'' refer to the EPA.
Table of Contents
I. What action is the EPA proposing?
II. Background
A. NAAQS, SIPs, Designations, and Clark County
B. 2008 and 2015 Ozone NAAQS
C. Transportation Conformity and the 2018 Ozone Maintenance Plan
Revision
III. What did the State submit?
IV. Procedural Requirements for Adoption and Submittal of SIP
Revisions
V. The EPA's Evaluation of the 2020 Ozone Maintenance Plan Revision
A. Emission Inventories
B. Revised Motor Vehicle Emissions Budgets
C. CAA Section 110(l) Evaluation
VI. Proposed Action and Request for Public Comment
VII. Statutory and Executive Order Reviews
I. What action is the EPA proposing?
Under section 110(k) of the Clean Air Act (``Act'' or CAA), the EPA
is required to take action by approving, disapproving, or conditionally
approving, in whole or in part, SIPs and SIP revisions submitted by the
states. In today's action, the EPA is proposing to approve a SIP
revision titled ``Revision to Motor Vehicle Emissions Budgets for the
1997 Ozone NAAQS, Clark County, Nevada'' (August 2020) (herein,
referred to as the ``2020 Ozone Maintenance Plan Revision''), submitted
by the Nevada Division of Environmental Protection (NDEP) on September
30, 2020.\1\ The 2020 Ozone Maintenance Plan Revision updates certain
elements of the maintenance plan for Clark County for the 1997 ozone
NAAQS, including certain emissions inventories and the motor vehicle
emissions budgets (``budgets'' or MVEBs). The 2020 Ozone Maintenance
Plan Revision was prepared in response to the EPA's conditional
approval of the ``Revision to Motor Vehicle Emissions Budgets in Ozone
Redesignation Request and Maintenance Plan: Clark County,
[[Page 43462]]
Nevada'' (October 2018) (herein, referred to as the ``2018 Ozone
Maintenance Plan Revision'').\2\ The 2020 Ozone Maintenance Plan
Revision revises certain budgets from the 2018 Ozone Maintenance Plan
Revision to prevent interference with reasonable further progress or
attainment of the 2008 and 2015 ozone NAAQS. If the EPA takes final
action to approve the 2020 Ozone Maintenance Plan Revision, the revised
budgets will replace Clark County's existing budgets for the plan
horizon year (2022) for the 1997 ozone NAAQS. At that time, the
previously-approved budgets would no longer be applicable for
transportation conformity purposes, and the revised budgets would need
to be used beginning on the publication date of the EPA's final
approval in the Federal Register.\3\
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\1\ NDEP submitted the 2020 Ozone Maintenance Plan Revision
electronically on September 30, 2020, as an attachment to a
transmittal letter dated September 25, 2020.
\2\ 84 FR 44699 (August 27, 2019).
\3\ 40 CFR 93.118(f)(2)(v).
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II. Background
A. NAAQS, SIPs, Designations, and Clark County
Under section 109 of the CAA, the EPA promulgates NAAQS for
pervasive air pollutants, such as ozone. The NAAQS are concentration
levels that, the attainment and maintenance of which, the EPA has
determined to be requisite to protect public health and welfare. Under
CAA section 107(d), the EPA must designate all areas of the country as
attainment, nonattainment or unclassifiable for new or revised NAAQS.
Section 110 of the CAA requires states to develop and submit SIPs to
implement, maintain, and enforce the NAAQS. Once a nonattainment area
has attained the NAAQS, the state may request redesignation of the area
from nonattainment to attainment, and the EPA grants such requests if
the criteria in CAA section 107(d)(3)(E) are met, including the
approval of a maintenance plan (under CAA section 175A) that
demonstrates how the area will maintain the NAAQS for at least 10 years
after the redesignation. Such former nonattainment areas that have been
redesignated to attainment are referred to as ``maintenance areas.''
In 1997, the EPA replaced the 1-hour ozone \4\ NAAQS at a level of
0.12 parts per million (ppm) with an 8-hour ozone NAAQS at a level of
0.08 ppm (herein, the ``1997 ozone NAAQS'').\5\ In 2004, the EPA
designated a portion of Clark County as a ``Subpart 1'' nonattainment
area for the 1997 ozone NAAQS.\6\ In 2011, the EPA determined that the
Clark County 8-hour ozone nonattainment area had attained the 1997 8-
hour ozone NAAQS, based on complete, quality-assured, and certified
ambient air monitoring data that showed the area monitored attainment
of the 1997 ozone NAAQS for the 2007-2009 monitoring period.\7\
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\4\ Ground-level ozone pollution is formed from the reaction of
volatile organic compounds (VOC) and oxides of nitrogen
(NO<INF>X</INF>) in the presence of sunlight. These two pollutants,
referred to as ozone precursors, are emitted by many types of
sources, including on-and off-road motor vehicles and engines, power
plants and industrial facilities, and smaller area sources such as
lawn and garden equipment and paints.
\5\ 62 FR 38856 (July 18, 1997) and 40 CFR 50.10.
\6\ 69 FR 23858 (April 30, 2004) and 69 FR 55956 (September 17,
2004). The Clark County ozone nonattainment area for the 1997 ozone
NAAQS includes a significant portion of the unincorporated portions
of central and southern Clark County, as well as the cities of Las
Vegas, Henderson, North Las Vegas, and Boulder City. The ``Subpart
1'' classification meant that the area was subject solely to the
general nonattainment area requirements under subpart 1 of part D
(of title I) of the CAA rather than to the requirements under both
subparts 1 and the ozone-specific requirements under subpart 2.
Several years later, in response to litigation over the designations
for the 1997 ozone NAAQS, the EPA revised the classification of the
Clark County ozone nonattainment area from ``Subpart 1'' to
``Subpart 2/Marginal.'' 77 FR 28424 (May 14, 2012).
\7\ 76 FR 17343 (March 29, 2011).
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In light of ambient monitoring data showing that the Clark County
ozone nonattainment area had attained the 1997 ozone NAAQS, NDEP
submitted a request to redesignate the Clark County ozone area from
nonattainment to attainment and submitted the ``Ozone Redesignation
Request and Maintenance Plan, Clark County, Nevada (March 2011)''
(herein, the ``2011 Ozone Maintenance Plan'') to the EPA for approval
as a revision to the Clark County portion of the Nevada SIP. Prepared
by the Clark County Department of Air Quality and Environmental
Management (currently named ``Department of Environment and
Sustainability'' (DES)),\8\ the 2011 Ozone Maintenance Plan includes
the required elements for maintenance plans, including an attainment
inventory, maintenance demonstration, monitoring network, verification
of continued attainment, contingency plan, and budgets.\9\ The 2011
Ozone Maintenance Plan demonstrates maintenance of the 1997 ozone NAAQS
through year 2022 by reference to emissions inventories developed for
years 2015 and 2022 that show emissions of volatile organic compounds
(VOC) and oxides of nitrogen (NO<INF>X</INF>) in those years would not
exceed the level of the corresponding emissions of the 2008 attainment
inventory. The 2011 Ozone Maintenance Plan established budgets for
NO<INF>X</INF> and VOC for years 2008, 2015, and 2022. The budgets were
derived from the on-road motor vehicle emissions estimates prepared
using the EPA's then-current on-road vehicle emissions model,
MOBILE6.2, and the most recent vehicle mix and activity data available
from the Regional Transportation Commission of Southern Nevada. In
2013, the EPA approved the 2011 Ozone Maintenance Plan and redesignated
the Clark County ozone nonattainment area to attainment for the 1997
ozone NAAQS.\10\
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\8\ In the State of Nevada, NDEP is the Governor's designee for
adoption and submittal of SIPs and SIP revisions to the EPA. In
Clark County, the Clark County DES is responsible under state law
for regulation of most types of stationary sources within the county
and for development of local air quality plans. Once adopted by the
Clark County Board of County Commissioners, such county plans are
forwarded to NDEP for adoption and submittal to the EPA as revisions
to the Nevada SIP.
\9\ Under the EPA's transportation conformity rule, at 40 CFR
93.101, budgets are defined as the portions of the total allowable
emissions that are allocated to on-road vehicle use that, together
with emissions from other sources in the area, will provide for RFP,
attainment or maintenance. The budgets serve as a ceiling on
emissions from an area's planned transportation system.
\10\ 78 FR 1149 (January 8, 2013).
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Through adoption of the 2011 Ozone Maintenance Plan, Clark County
DES committed to maintaining an ambient air quality monitoring network
to verify the continued attainment of the 1997 ozone NAAQS in the Clark
County ozone maintenance area.\11\ At the present time, 10 monitoring
sites continuously monitor ambient concentrations of ozone within the
maintenance area. Since 2008, i.e., the year used for the attainment
inventory in the 2011 Ozone Maintenance Plan, ambient ozone
concentrations in Clark County have decreased. As shown in Table 1, 8-
hour ozone design values have decreased from 0.082 ppm in 2008 to 0.073
ppm in 2019.\12\ In more recent years, the design value has remained
relatively steady, varying little from year to year. Table 1 shows that
Clark County has maintained the 1997 ozone NAAQS through the first
seven years (2013 through 2019) of the first maintenance period.
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\11\ 2011 Ozone Maintenance Plan, 6-11.
\12\ Under EPA regulations at 40 CFR 50.10 and appendix I, the
1997 ozone NAAQS is attained at a site when the 3-year average of
the annual fourth-highest daily maximum 8-hour average ozone
concentration is less than or equal to 0.08 ppm. This 3-year average
is referred to as the design value. When the design value is less
than or equal to 0.084 ppm (based on the rounding convention in 40
CFR part 50, appendix I) at each monitoring site within the area,
then the area is meeting the 1997 ozone NAAQS. The highest design
value among the various ozone monitoring sites represents the design
value for the area.
[[Page 43463]]
Table 1--Eight-Hour Ozone Design Values for the Clark County Ozone
Maintenance Area, 2008-2020
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Design value
Year (ppm)
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2008.................................................... 0.082
2009.................................................... 0.078
2010.................................................... 0.076
2011.................................................... 0.075
2012.................................................... 0.076
2013.................................................... 0.077
2014.................................................... 0.078
2015.................................................... 0.075
2016.................................................... 0.075
2017.................................................... 0.074
2018.................................................... 0.076
2019.................................................... 0.073
2020.................................................... 0.074
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Source: The EPA's 2017 and 2020 Ozone Design Values Reports at <a href="https://www.epa.gov/air-trends/air-quality-design-values#report">https://www.epa.gov/air-trends/air-quality-design-values#report</a>. Note that
design values reported for a given year reflect data from that year
and the two previous years, e.g., the design value for 2008 reflects
data from 2006-2008.
B. 2008 and 2015 Ozone NAAQS
In 2008, the EPA lowered the ozone NAAQS to a level of 0.075 ppm,
8-hour average (herein, the ``2008 ozone NAAQS''),\13\ and in 2012, the
EPA designated all of the hydrographic areas within the State of Nevada
as ``Unclassifiable/Attainment'' for the 2008 ozone NAAQS.\14\ Because
all the hydrographic areas located entirely, or partially, within Clark
County were designated as unclassifiable/attainment for the 2008 ozone
NAAQS, no reasonable further progress (RFP) or attainment SIP revision
was required for any portion of the county.
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\13\ 73 FR 16436 (March 27, 2008) and 40 CFR 50.15.
\14\ 77 FR 30088 (May 21, 2012). Hydrographic areas are those
that are shown on the State of Nevada Division of Water Resources'
map titled ``Water Resources and Inter-basin Flows'' (September
1971).
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In 2015, the EPA further lowered the ozone NAAQS to 0.070 ppm, 8-
hour average (herein the ``2015 ozone NAAQS'').\15\ In 2018, the EPA
designated the Las Vegas Valley portion of Clark County as a
``Marginal'' nonattainment area for the 2015 ozone NAAQS, effective
August 3, 2018.\16\ The nonattainment area designation for Las Vegas
Valley for the 2015 ozone NAAQS triggered the requirement for certain
SIP revisions under CAA section 182(a) and the EPA's related SIP
Requirements Rule promulgated at 40 CFR part 51, subpart CC.
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\15\ 80 FR 65292 (October 26, 2015) and 40 CFR 50.19.
\16\ 83 FR 25776 (June 4, 2018).
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C. Transportation Conformity and the 2018 Ozone Maintenance Plan
Revision
The EPA's transportation conformity rule at 40 CFR part 93, subpart
A establishes the criteria and procedures that metropolitan planning
organizations (MPOs) and the U.S. Department of Transportation (DOT)
must use to determine whether transportation activities conform to the
SIP. Transportation conformity applies to areas that are designated
nonattainment and those former nonattainment areas that have been
redesignated to attainment and have a CAA section 175A maintenance plan
(``maintenance areas''), but does not apply to areas designated as
attainment or unclassifiable.\17\ In Clark County, the area's MPO, the
Regional Transportation Commission of Southern Nevada (RTC), and DOT
are the relevant transportation agencies that must determine the
conformity of transportation plans and transportation improvement plans
(TIPs) within Clark County.
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\17\ CAA section 176(c)(5).
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Under our transportation conformity rule, the latest approved or
adequate emissions budgets for a previous ozone NAAQS (i.e., the 2008
or the 1997 ozone NAAQS) must be used in conformity determinations for
the 2015 ozone NAAQS until emission budgets are established and found
adequate or are approved for the 2015 ozone NAAQS. Because the latest
approved or adequate emissions budgets for a previous ozone NAAQS for
Clark County are the approved budgets for the 1997 8-hour ozone NAAQS,
the RTC and DOT must use these budgets for conformity determinations
for the 2015 ozone NAAQS \18\ until they are replaced by updated
budgets for the 2015 ozone NAAQS.
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\18\ The EPA's guidance ``Transportation Conformity Guidance for
the South Coast II Court Decision'' (November 2018, EPA-20-B-18-
050), explains that while conformity requirements continue to apply
for the revoked 1997 ozone NAAQS, conformity can be demonstrated
without a regional emissions analysis for the 1997 ozone standard.
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In 2018, NDEP submitted the 2018 Ozone Maintenance Plan Revision as
a revision to the Clark County portion of the Nevada SIP. The 2018
Ozone Maintenance Plan Revision includes revisions to the attainment
inventory, the maintenance demonstration, and budgets in the 2011 Ozone
Maintenance Plan to reflect updated emissions models, vehicle mix and
speed data, and transportation activity projections. The 2018 Ozone
Maintenance Plan Revision revised the budgets for NO<INF>X</INF> and
VOC for years 2008, 2015, and 2022. The revised budgets were derived
from the on-road motor vehicle emissions estimates prepared using the
most recent version of the EPA's on-road vehicle emissions model
available at the time (MOVES2014a) and updated planning variables
(e.g., vehicle miles traveled projections and population forecasts)
from the RTC. The 2018 Ozone Maintenance Plan Revision was developed so
that the RTC and DOT would have updated budgets available to use for
transportation conformity determinations with respect to the 2015 ozone
NAAQS until budgets developed specifically for the 2015 ozone NAAQS are
adopted and found to be adequate or approved. In 2019, the EPA
conditionally approved the 2018 Ozone Maintenance Plan Revision as a
revision of the Clark County portion of the Nevada SIP.\19\
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\19\ 84 FR 44699 (August 27, 2019).
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In so doing, we found that the 2011 Ozone Maintenance Plan, as
revised by the updated attainment inventory and maintenance
demonstration in the 2018 Ozone Maintenance Plan Revision, continues to
provide for maintenance of the 1997 ozone NAAQS, and upon fulfillment
of the commitments made by NDEP and Clark County DES to reduce the
safety margin allocations for the budgets, will not interfere with RFP
or attainment of the other NAAQS in Clark County. In conditionally
approving the 2018 Ozone Maintenance Plan Revision, the EPA also found
adequate and conditionally approved the updated NO<INF>X</INF> and VOC
budgets for 2008, 2015, and 2022 for the 1997 ozone NAAQS based on our
conclusion that the updated budgets meet the applicable transportation
conformity requirements. The approval was conditional because it is
based on commitments by Clark County DES and NDEP to submit an
additional SIP revision to reduce the safety margin allocations for the
budgets in the 2018 Ozone Maintenance Plan Revision within one year of
this final conditional approval.
In September 2020, NDEP submitted the 2020 Ozone Maintenance Plan
Revision to the EPA in fulfillment of the commitments made by Clark
County DES and NDEP in connection with the EPA's conditional approval
of the 2018 Ozone Maintenance Plan Revision. The 2020 Ozone Maintenance
Plan Revision is the subject to today's proposed action.
III. What did the State submit?
On August 18, 2020, the Clark County Board of County Commissioners
adopted the 2020 Ozone Maintenance Plan Revision and forwarded the plan
to NDEP for adoption and submittal to the
[[Page 43464]]
EPA.\20\ On September 30, 2020, NDEP submitted the 2020 Ozone
Maintenance Plan Revision to the EPA as a revision to the Clark County
portion of the Nevada SIP.\21\ The 2020 Ozone Maintenance Plan Revision
also includes a technical support document (appendix A of the plan
revision) and documentation of the public review process (appendix B of
the plan revision).
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\20\ Clark County Board of County Commissioners Meeting, Meeting
Summary, October 16, 2018, 14 and 15.
\21\ Letter dated September 25, 2020, from Greg Lovato,
Administrator, NDEP to Elizabeth Adams, Director, Air Division, EPA
Region IX, (submitted electronically on September 30, 2020 with
enclosures).
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Through the 2020 Ozone Maintenance Plan Revision, Clark County DES
is updating the emissions projections for the ozone maintenance plan
horizon year of 2022 based on the latest available emissions models,
vehicle mix and speed data, and transportation activity projections and
is revising the budgets for 2022 to reflect the updated projections for
that year and to include a reduced safety margin compared to the
corresponding budgets from the 2018 Ozone Maintenance Plan Revision.
The 2020 Ozone Maintenance Plan Revision also presents a new emissions
inventory for year 2017 that provides the basis to evaluate the new
budgets with respect to continued attainment of the 2008 ozone NAAQS
and progress towards attainment of the 2015 ozone NAAQS in Las Vegas
Valley.
IV. Procedural Requirements for Adoption and Submittal of SIP Revisions
Sections 110(a)(1) and (2) and 110(l) of the CAA require a state to
provide reasonable public notice and opportunity for public hearing
prior to the adoption and submittal of a SIP or SIP revision. To meet
this requirement, every SIP submittal should include evidence that
adequate public notice was given and an opportunity for a public
hearing was provided consistent with the EPA's implementing regulations
in 40 CFR 51.102.
The Clark County Board of County Commissioners and NDEP have
satisfied applicable statutory and regulatory requirements for
reasonable public notice and public hearing prior to adoption and
submittal of the 2020 Ozone Maintenance Plan Revision. In the September
30, 2020 SIP submittal,\22\ Clark County DES provided evidence of the
required public notice and opportunity for public comment prior to the
August 18, 2020 public hearing and adoption of the 2020 Ozone
Maintenance Plan Revision. Therefore, we find that the submittal of the
2020 Ozone Maintenance Plan Revision meets the procedural requirements
for public notice and hearing in CAA sections 110(a) and 110(l) and 40
CFR 51.102.
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\22\ Appendix B provides evidence that reasonable notice of a
public hearing was provided to the public and that a public hearing
was conducted prior to adoption. Specifically, notice of the
availability of, and opening of a 30-day comment period on the draft
ozone maintenance plan revision was published on June 25, 2020, on
the County's webpage. No comments were submitted.
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V. The EPA's Evaluation of the 2020 Ozone Maintenance Plan Revision
Clark County DES and NDEP submitted the 2020 Ozone Maintenance Plan
Revision to fulfill commitments made in connection with the EPA's
conditional approval of the 2018 Ozone Maintenance Plan Revision to
reduce the safety margin allocations in the budgets to ensure that the
Clark County ozone SIP will not interfere with RFP or attainment of the
2008 and 2015 ozone NAAQS consistent with CAA section 110(l). As
described further below, we have reviewed the 2020 Ozone Maintenance
Plan Revision for compliance with the relevant requirements for
maintenance plans under CAA section 175A and for noninterference under
CAA section 110(l), and we have evaluated the budgets in the 2020 Ozone
Maintenance Plan Revision for compliance with the budget adequacy
criteria in 40 CFR 93.118(e).
A. Emissions Inventories
The 2020 Ozone Maintenance Plan Revision includes inventories of
emissions of ozone precursors (VOC and NO<INF>X</INF>) for years 2017
and 2022. The 2017 inventory provides estimates of actual emissions
that occurred in that year. Clark County DES selected 2017 as the base
year for the 2020 Ozone Maintenance Plan Revision for the following
reasons: It is the most recent year for which National Emissions
Inventory \23\ (NEI) emissions estimates were available at the time the
plan was being developed; it is an attainment year for the 2008 ozone
NAAQS; and it is the base year for SIP planning purposes for the 2015
ozone NAAQS. Clark County DES used the 2017 inventory to revise the
2022 emissions inventory from the 2018 Ozone Maintenance Plan Revision
based on the latest methods and planning assumptions.
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\23\ The NEI is a comprehensive and detailed estimate of air
emissions of criteria pollutants, criteria precursors, and hazardous
air pollutants from air emissions sources. The NEI is released every
three years based primarily upon data provided by State, Local, and
Tribal air agencies for sources in their jurisdictions and
supplemented by data developed by the EPA.
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As a general matter, base year emissions inventories must be (1)
consistent with the EPA's most recent guidance on emissions inventories
available at the time, (2) comprehensive, including emissions from
stationary point sources, area sources, nonroad mobile sources, and on-
road mobile sources, and (3) based on actual ``ozone season data''
(i.e., summertime) emissions.\24\
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\24\ In Clark County, Nevada, the highest ambient ozone
concentrations generally occur during the months of the year when
the highest temperatures occur--typically from May through
September. For SIP planning purposes, Clark County has selected
weekdays in the month of July as the basis to estimate typical
summertime weekday emissions.
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The 2017 year inventory in the 2020 Ozone Maintenance Plan Revision
is comprehensive in that it includes estimates of summertime average
weekday VOC and NO<INF>X</INF> emissions from all of the relevant
source categories, which the plan divides among point sources,\25\
nonpoint sources,\26\ commercial aviation, federal aviation (i.e.,
Nellis Air Force Base), on-road mobile, nonroad mobile, and biogenic
\27\ sources.\28\ For comparison, the 2018 Ozone Maintenance Plan
Revision did not include a 2017 inventory, but emissions for 2017 can
be interpolated from 2015 and 2022 emissions. Appendix A to the 2020
Ozone Maintenance Plan Revision contains source-specific descriptions
of emission calculation procedures and sources of input data used for
the update.
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\25\ The 2020 Ozone Maintenance Plan Revision uses the term,
``point sources,'' to refer to those stationary source facilities
that are required to report their emissions to Clark County DES or
NDEP.
\26\ The 2020 Ozone Maintenance Plan Revision uses the term,
``nonpoint sources,'' to refer to those stationary and area sources
that fall below point source reporting levels and that are too
numerous or small to identify individually.
\27\ For the 2020 Ozone Maintenance Plan Revision, ``biogenic
sources'' include the following: Agricultural crops; lawn grass;
forests that produce isoprene, monoterpene, alpha-pinene, and other
VOC emissions; and soils that generate trace amounts of
NO<INF>X</INF>.
\28\ See Table 2-1 in the 2020 Ozone Maintenance Plan Revision.
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Table 2 below compares the 2017 inventory from the 2020 Ozone
Maintenance Plan Revision with the corresponding interpolated inventory
from the 2018 Ozone Maintenance Plan Revision. As shown in Table 2, the
change in the 2017 inventory in the 2020 Ozone Maintenance Plan
Revision is primarily due to the update to the on-road mobile source
category and the nonroad source category as well as a change in the
methodology for biogenic emissions.
[[Page 43465]]
Table 2--2017 Clark County Ozone Precursor Emission Inventory
[County-wide, average summer weekday, tons per day]
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NOX emissions VOC emissions
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Source category 2020 Ozone 2018 Ozone 2020 Ozone 2018 Ozone
maintenance maintenance maintenance maintenance
plan revision plan revision plan revision plan revision
----------------------------------------------------------------------------------------------------------------
Point source.................................... 12.40 11.79 2.95 2.51
Nonpoint source................................. 7.651 5.68 62.56 59.94
Commercial aviation............................. 11.47 13.38 1.73 2.75
Federal aviation................................ 0.50 1.77 0.24 1.04
On-road mobile.................................. 46.96 53.65 29.47 28.49
Nonroad mobile.................................. 37.45 24.78 28.25 30.36
Biogenic........................................ 2.43 5.00 362.61 132.00
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Total....................................... 118.86 116.06 487.81 257.09
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Sources: 2018 Ozone Maintenance Plan Revision, interpolated values from Tables 2-1 and 2-2; 2020 Ozone
Maintenance Plan Revision, Tables 2-1 and 2-2.
With respect to on-road mobile source emissions, Clark County DES
updated the emissions estimates using MOVES2014b, RTC travel demand
modeling, and highway performance monitoring system data from the
Nevada Department of Transportation.\29\ Clark County DES also selected
the inventory mode, rather than the emission rate mode used in the 2018
Ozone Maintenance Plan Revision, with MOVES2014b emissions factors and
projected emissions for 2022 from 2017 rather than 2015. Generally, on-
road mobile source emissions estimates made using MOVES2014b are
similar to MOVES2014a. With respect to nonroad emissions sources, the
change in the 2017 emissions inventory is largely due to the use of the
nonroad module of MOVES2014b that was released in August 2018. Clark
County DES used default estimates from MOVES2014b for Clark County and
the most significant changes were in the two largest sectors:
construction and lawn/garden, which increased and decreased,
respectively. Overall, nonroad emissions are higher for NO<INF>X</INF>
but lower for VOC using MOVES2014b compared to using the nonroad module
of MOVES2014a.
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\29\ 2020 Ozone Maintenance Plan Revision, Appendix A, 4-12.
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Biogenic emissions for Clark County were developed using the EPA's
Biogenic Emission Inventory System \30\ (BEIS) version 3.61, which
replaced the Emissions of Gasses and Aerosols from Nature (MEGAN) model
used by Clark County DES for the 2011 Ozone Maintenance Plan \31\ and
the 2018 Ozone Maintenance Plan Revision. The BEIS model allows for
interactions between air quality and meteorology. In 2017, the EPA
updated the BEIS v3.61 to include the biogenic emissions landcover
database version 5 (BELD5) and the newer version of the forest
inventory and analysis version 8.0. This updated model improved the
biogenic VOC emissions estimates. Clark County DES used the updated
BEIS model, which is part of SMOKE 4.7 (Sparse Matrix Operator Kerner
Emissions) model, to generate the biogenic emissions for Clark
County.\32\ The results show a slight decrease in NO<INF>X</INF> and
large increase in VOC biogenic emissions relative to the corresponding
emissions estimates from the 2011 Ozone Maintenance Plan and 2018 Ozone
Maintenance Plan Revision.
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\30\ <a href="https://www.epa.gov/air-emissions-modeling/biogenic-emission-inventory-system-beis">https://www.epa.gov/air-emissions-modeling/biogenic-emission-inventory-system-beis</a>.
\31\ 2011 Ozone Maintenance Plan, 6-4.
\32\ 2020 Ozone Maintenance Plan Revision, 14.
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Based on our review of the emissions inventories (and related
documentation) from the 2020 Ozone Maintenance Plan Revision, we find
that the inventories for 2017 are comprehensive, that the methods and
assumptions used by Clark County DES to develop the 2017 emission
inventory are reasonable, and that the inventories reasonably estimate
actual ozone season emissions in 2017. Moreover, we find that the 2017
emissions inventories in the plan reflect the latest planning
assumptions and emissions models available at the time the 2020 Ozone
Maintenance Plan Revision was developed.
To provide the basis for the comparison of future emissions with
the updated 2017 emissions, Clark County DES updated the 2022 emissions
inventories using the same approaches as described above for the 2017
emissions inventory. Clark County DES allocated the same amount of
emissions reductions credits (ERCs), for use in connection with the new
major stationary source permitting program, for 2022 as had been
allocated for that year in the 2018 Ozone Maintenance Plan Revision.
With respect to transportation conformity safety margins, as described
further in section V.B of this document, the Clark County DES
significantly reduced the safety margins that had been included in
budgets for the 2018 Ozone Maintenance Plan Revision. Table 3 below
compares the NO<INF>X</INF> and VOC emissions inventories,
respectively, for 2022 from the 2020 Ozone Maintenance Plan Revision
with the corresponding values from the 2018 Ozone Maintenance Plan
Revision.
Table 3--2022 Clark County Ozone Precursor Emission Inventory
[County-wide, average summer weekday, tons per day]
----------------------------------------------------------------------------------------------------------------
NOX emissions VOC emissions
---------------------------------------------------------------
Source category 2020 Ozone 2018 Ozone 2020 Ozone 2018 Ozone
maintenance maintenance maintenance maintenance
plan revision plan revision plan revision plan revision
----------------------------------------------------------------------------------------------------------------
Point source.................................... 12.09 12.26 3.12 2.72
[[Page 43466]]
Nonpoint source................................. 7.57 5.04 62.58 59.49
Commercial aviation............................. 13.08 17.42 1.73 2.95
Federal aviation................................ 1.97 2.26 0.82 0.95
On-road mobile.................................. 29.16 27.02 20.92 17.12
Nonroad mobile.................................. 24.93 17.50 26.71 28.52
Biogenic........................................ 2.43 5.00 362.61 132.00
Emission reduction credits...................... 22.23 22.23 0.43 0.43
Transportation conformity safety margins........ 3.00 59.72 3.00 35.84
---------------------------------------------------------------
Total....................................... 116.46 168.45 484.92 280.02
----------------------------------------------------------------------------------------------------------------
Sources: 2018 Ozone Maintenance Plan Revision, Tables 2-1, 2-2 and 3-1; 2020 Ozone Maintenance Plan Revision,
Tables 2-1, 2-2 and 3-1.
As shown in Table 3, emissions for 2022 in the 2020 Ozone
Maintenance Plan Revision are similar to the corresponding emissions in
the 2018 Ozone Maintenance Plan Revision except for biogenic emissions.
Similar to the comparison of the emission inventories for the year
2017, differences are again primarily due to the updates to the on-road
mobile source category, the nonroad source category, and the change in
the methodology for biogenic emissions. The on-road mobile source
emission estimates in the 2020 Ozone Maintenance Plan Revision reflect
the most recent published data concerning vehicle registration data,
vehicle miles traveled (VMT) temporal distribution, VMT mix profiles,
vehicle speeds, and travel demand forecasts from RTC.\33\
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\33\ Key references used by Clark County DES include Eastern
Research Group's ``Clark County On-Road Vehicle Classification
Study,'' final report, June 29, 2018, and the Coordinating Research
Council's ``Improvement of Default Inputs for MOVES and SMOKE-MOVES,
final report, February 2017.
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Based on our review of the methods, assumptions, and data sources,
as described in Appendix A to the 2020 Ozone Maintenance Plan Revision,
we find that the Clark County DES estimates for 2017 and 2022 for the
various source categories to be based on the best available emissions
models and data sources, and thus to provide a reasonable basis upon
which to evaluate whether the area will continue to maintain the 1997
ozone NAAQS through 2022 and whether the revised budgets for 2022 in
the 2020 Ozone Maintenance Plan Revision would interfere with RFP or
attainment of the 2008 and 2015 ozone NAAQS.
B. Revised Motor Vehicle Emissions Budgets
Section 176(c) of the CAA requires federal actions in nonattainment
and maintenance areas to conform to the SIP's goals of eliminating or
reducing the severity and number of violations of the NAAQS and
achieving timely attainment of the standards. Conformity to the SIP's
goals means that such actions will not: (1) Cause or contribute to
violations of a NAAQS, (2) worsen the severity of an existing
violation, or (3) delay timely attainment of any NAAQS or any interim
milestone.
Under the transportation conformity rule, MPOs in nonattainment and
maintenance areas coordinate with state and local air quality and
transportation agencies, the EPA, the Federal Highway Administration,
and the Federal Transit Administration to demonstrate that an area's
regional transportation plans and TIPs conform to the applicable SIP.
This demonstration is typically done by showing that estimated
emissions from existing and planned highway and transit systems are
less than or equal to the budgets contained in all control strategy or
maintenance SIPs. Budgets are generally established for specific years
and specific pollutants or precursors. Ozone maintenance plans should
identify budgets for on-road emissions of ozone precursors
(NO<INF>X</INF> and VOC) in the area for the last year of the
maintenance period. Budgets may also be specified for additional years
during the maintenance period.
For budgets to be approvable, they must meet the EPA's adequacy
criteria (40 CFR 93.118(e)(4) and (5)) and comply with all pertinent
SIP requirements. With respect to maintenance plans, to meet these
requirements, the budgets must be consistent with the maintenance plan
and reflect all the motor vehicle control measures contained in the
maintenance demonstration.\34\ The EPA's process for determining
adequacy of a budget consists of three basic steps: (1) Providing
public notification of a SIP submission; (2) providing the public the
opportunity to comment on the budget during a public comment period;
and, (3) making a finding of adequacy or inadequacy.\35\ We will
complete the adequacy review of the budgets in the 2020 Ozone
Maintenance Plan Revision concurrent with our final action on the 2020
Ozone Maintenance Plan Revision. The EPA is not required under its
transportation conformity rule to find budgets adequate prior to
proposing approval of them.\36\
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\34\ 40 CFR 93.118(e)(4)(iii), (iv) and (v). For more
information on the transportation conformity requirements and
applicable policies on budgets, please visit our transportation
conformity website at: <a href="http://www.epa.gov/otaq/stateresources/transconf/index.htm">http://www.epa.gov/otaq/stateresources/transconf/index.htm</a>.
\35\ 40 CFR 93.118(f)(2).
\36\ Under the transportation conformity regulations, the EPA
may review the adequacy of submitted motor vehicle emission budgets
simultaneously with the EPA's approval or disapproval of the
submitted implementation plan. 40 CFR 93.118(f)(2).
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The 2020 Ozone Maintenance Plan Revision includes revised budgets
for VOC and NO<INF>X</INF> for the last year of the initial maintenance
period, i.e., 2022.\37\ The revised budgets from the 2020 Ozone
Maintenance Plan Revision are shown in Table 4 below and compared with
the corresponding budgets from the approved 2018 Ozone Maintenance
[[Page 43467]]
Plan Revision. As noted in section V.A of this document, Clark County
DES developed the revised budgets using the latest emissions model
(MOVES2014b) available at the time the 2020 Ozone Maintenance Plan
Revision was being developed, and the most recent travel activity
projections provided by the Nevada Department of Transportation and
RTC. Therefore, we find that the revised budgets reflect the most
recent planning forecasts and are based on the most recent emission
factor data and approved calculation methods.
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\37\ The 2020 Ozone Maintenance Plan Revision does not revise
the 2015 budgets from the 2018 Ozone Maintenance Plan Revision that
also included large safety margins; however, we note that, given the
passage of time, the 2015 budgets from the 2018 Ozone Maintenance
Plan Revision will no longer be used for conformity determinations
and thus the failure to reduce the safety margins of the 2015
budgets in the 2018 Ozone Maintenance Plan Revision is acceptable.
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A state may choose to allocate all or a portion of the safety
margin \38\ under the EPA transportation conformity rule so long as
such margins are explicitly quantified in the applicable plan and are
shown to be consistent with attainment or maintenance of the NAAQS
(whichever is relevant to the particular plan).\39\ For the 2020 Ozone
Maintenance Plan Revision, Clark County DES allocated a 3 tons per day
(tpd) safety margin for NO<INF>X</INF> and VOC in 2022 to the projected
on-road emissions estimates for NO<INF>X</INF> and VOC.
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\38\ In this context, ``safety margin'' means the amount by
which the total projected emissions from all sources of a given
pollutant are less than the total emissions that would satisfy the
applicable requirements for reasonable further progress, attainment
or maintenance. With respect to the 2020 Ozone Maintenance Plan
Revision, the safety margin is the difference between the projected
emissions in 2022 of NO<INF>X</INF> and VOC and the actual emissions
of NO<INF>X</INF> and VOC in the 2008 attainment year as updated in
the 2018 Ozone Maintenance Plan Revision. The anthropogenic
emissions (i.e., excluding biogenic emissions) of NO<INF>X</INF> and
VOC in 2008 were approximately 178 tons per day (tpd) and 157 tpd,
respectively. The 2020 Ozone Maintenance Plan Revision continues to
provide for maintenance of the 1997 ozone NAAQS because the
anthropogenic emissions of NO<INF>X</INF> and VOC in 2022 (including
the ERCs and transportation conformity safety margins) would be
approximately 114 tpd and 122 tpd, respectively, which is
substantially less than the emissions in the attainment year (2008)
for the 1997 ozone NAAQS.
\39\ See 40 CFR 93.124(a).
Table 4--Clark County Year 2022 Ozone Motor Vehicle Emission Budgets
[County-wide, average summer weekday, tpd]
----------------------------------------------------------------------------------------------------------------
2018 Ozone maintenance plan 2020 Ozone maintenance plan
revision revision
Source category ---------------------------------------------------------------
NOX VOC NOX VOC
----------------------------------------------------------------------------------------------------------------
On-Road Mobile.................................. 27.02 17.12 29.16 20.92
Transportation Conformity Safety Margins........ 59.72 35.84 3.00 3.00
Budgets......................................... 86.74 52.96 32.16 23.92
----------------------------------------------------------------------------------------------------------------
Sources: 2018 Ozone Maintenance Plan Revision, Table 3-1; 2020 Ozone Maintenance Plan Revision, Table 3-1.
As documented in a April 20, 2021 memorandum to the docket for this
rulemaking, we find that the budgets in the 2020 Ozone Maintenance Plan
Revision meet each adequacy criterion.\40\ In short, we reviewed the
budgets in the 2020 Ozone Maintenance Plan Revision and found that they
are consistent with the revised maintenance demonstration from the 2018
Ozone Maintenance Plan Revision; are based on control measures that
have already been adopted and implemented; and meet all other
applicable statutory and regulatory requirements including the adequacy
criteria in 40 CFR 93.1118(e)(4) and (5). Therefore, we are proposing
to approve the 2022 budgets in the 2020 Ozone Maintenance Plan
Revision. If we finalize our approval of the revised budgets in the
2020 Ozone Maintenance Plan Revision, as proposed, they will replace
the corresponding budgets for the 1997 ozone NAAQS from the 2018 Ozone
Maintenance Plan Revision that we previously found adequate and
conditionally approved for use in transportation conformity
determinations.
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\40\ Memorandum dated April 20, 2021, from Karina O'Connor, Air
Planning Office, EPA Region IX, ``Adequacy Documentation for Plan
Motor Vehicle Emission Budgets in August 2020 Clark County Revision
to Ozone Maintenance Plan.'' This memorandum has been uploaded to
the docket (EPA-R09-OAR-2021-0368) for this rulemaking.
---------------------------------------------------------------------------
C. CAA Section 110(l) Evaluation
In relevant part, CAA section 110(l) provides that the EPA shall
not approve a SIP revision that would interfere with any applicable
requirement concerning attainment or RFP of any of the NAAQS or any
other applicable requirement of the CAA. The 2018 Ozone Maintenance
Plan Revision established budgets that are larger than those that were
previously approved from the 2011 Ozone Maintenance Plan. Thus,
approval of the 2018 Ozone Maintenance Plan Revision accommodated a
higher level of VOC and NO<INF>X</INF> emissions from on-road mobile
source emissions than would otherwise be allowed under the previous
budgets. In our approval of the 2018 Ozone Maintenance Plan Revision,
we evaluated the higher level of VOC and NO<INF>X</INF> emissions with
respect to the potential for interference with RFP and attainment of
the NAAQS for which VOC and NO<INF>X</INF> are precursors, namely, the
2008 and 2015 ozone NAAQS.\41\
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\41\ As a general matter, VOC and NO<INF>X</INF> are also
considered precursors for course particulate matter
(PM<INF>10</INF>) and fine particulate matter (PM<INF>2.5</INF>). In
our conditional approval of the 2018 Ozone Maintenance Plan
Revision, we concluded that the revised budgets, even with the
substantial safety margins, would not interfere with attainment or
maintenance of the PM<INF>10</INF> or PM<INF>2.5</INF> NAAQS. 84 FR
33035, at 33043-33044 (July 11, 2019) (proposed rule), finalized at
84 FR 44699 (August 27, 2019). Clark County is designated as
attainment for the PM<INF>10</INF> NAAQS and unclassifiable/
attainment for the PM<INF>2.5</INF> NAAQS. 40 CFR 81.329. In this
document, we are proposing approval of budgets that have been
revised to substantially reduce the safety margins, and thus, the
potential for interference with attainment or maintenance of the
PM<INF>10</INF> or PM<INF>2.5</INF> NAAQS is even less than it was
previously. As such, we find that approval of the 2020 Ozone
Maintenance Plan Revision would not interfere with attainment or
maintenance of the PM<INF>10</INF> or PM<INF>2.5</INF> NAAQS in
Clark County.
---------------------------------------------------------------------------
In our conditional approval of the 2018 Ozone Maintenance Plan
Revision, we determined that if the 2018 Ozone Maintenance Plan
Revision were revised to reduce the safety margin allocations to the
budgets such that total estimated emissions in 2022 (with the
allocations) would not exceed actual emissions in year 2017, then the
updated budgets would not interfere with reasonable further progress or
attainment of the 2008 and 2015 ozone NAAQS.
1. 2008 Ozone NAAQS
As noted in Section II.B of this document, in 2012, the EPA
designated all the hydrographic areas within the State of Nevada as
unclassifiable/attainment for the 0.075 ppm 2008 ozone NAAQS based on
ambient ozone concentration data for years 2009-2011.\42\ After the
original designation, the 8-hour ozone design values within Clark
County exceeded the 2008 ozone
[[Page 43468]]
NAAQS for a few years but, since 2015, the design values have generally
returned to attainment levels for the 2008 ozone NAAQS. As shown in
Table 1, the design value in year 2017 was 0.074 ppm, which is
consistent with attainment of the 0.075 ppm 2008 ozone NAAQS. Thus,
emissions of VOC and NO<INF>X</INF> in 2017 represent conditions under
which Clark County meets the 2008 ozone NAAQS.
---------------------------------------------------------------------------
\42\ Letter dated December 9, 2011, from Jared Blumenfeld,
Regional Administrator, EPA Region IX, to Brian Sandoval, Governor,
State of Nevada.
---------------------------------------------------------------------------
In recognition of the need to avoid interference with attainment of
the 2008 ozone NAAQS and progress toward attainment of the 2015 ozone
NAAQS, NDEP and Clark County DES committed to submit a SIP revision to
reduce the safety margin allocations to the 2022 budgets such that
total estimated emissions in 2022 (with the allocations) would not
exceed actual emissions in year 2017, a year in which Clark County was
attaining the 2008 ozone NAAQS.
As shown in Table 2 of this document, the 2020 Ozone Maintenance
Plan Revision estimates year 2017 emissions in Clark County to be
approximately 119 tpd of NO<INF>X</INF> and 488 tpd of VOC. In 2022, as
shown in Table 3 of this document, the 2020 Ozone Maintenance Plan
Revision estimates year 2022 emissions in Clark County to be
approximately 116 tpd of NO<INF>X</INF> and 485 tpd of VOC, including
the allocated ERCs for stationary sources and transportation conformity
safety margins for on-road mobile sources. As such, ozone precursor
emissions in year 2022 under the 2020 Ozone Maintenance Plan Revision
would be less than those in 2017, a year in which Clark County was
attaining the 2008 ozone NAAQS. As such, we find that the 2020 Ozone
Maintenance Plan Revision would not interfere with attainment of the
2008 ozone NAAQS in Clark County.
2. 2015 Ozone NAAQS
In 2018, the EPA designated the Las Vegas Valley (i.e.,
hydrographic area #212) as a Marginal nonattainment area for the 0.070
ppm 2015 ozone NAAQS based on ambient ozone concentration data for
years 2015-2017.\43\ The 2017 ozone design value is 0.074 ppm. To
attain the 0.070 ppm 2015 ozone NAAQS by the applicable Marginal area
attainment date, i.e., by August 3, 2021, VOC and NO<INF>X</INF>
emissions must decrease relative to those in 2017. NDEP and Clark
County DES committed to revise the 2018 Ozone Maintenance Plan Revision
and the associated safety margins for the budgets so that, the total
projected emissions (with the reduced safety margin allocations) in
year 2022 would be less than the actual emissions estimated for year
2017, the base year for implementation of the 2015 ozone NAAQS.
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\43\ EPA, ``Nevada, Las Vegas Nonattainment Area, Final Area
Designations for the 2015 Ozone National Ambient Air Quality
Standards, Technical Support Document (TSD).''
---------------------------------------------------------------------------
With respect to the 2015 ozone NAAQS, we are finding that ozone
precursor emissions in year 2022 under the 2020 Ozone Maintenance Plan
Revision would be less than those in 2017, the base year for
implementation of the 2015 ozone NAAQS. As such, we find that the 2020
Ozone Maintenance Plan Revision would not interfere with RFP towards
attainment of the 2015 ozone NAAQS.
VI. Proposed Action and Request for Public Comment
For the reasons discussed herein, under CAA section 110(k)(3), the
EPA is proposing to approve the 2020 Ozone Maintenance Plan Revision
submitted by NDEP on September 30, 2020, as a revision for the Clark
County portion of the Nevada SIP. We are proposing to approve the 2020
Ozone Maintenance Plan Revision because we find that the 2011 Ozone
Maintenance Plan, as revised by the 2018 Ozone Maintenance Plan
Revision, and as further revised by the 2020 Ozone Maintenance Plan
Revision, continues to provide for maintenance of the 1997 ozone NAAQS
and will not interfere with RFP or attainment of the other NAAQS in
Clark County. The EPA is also proposing to approve the updated budgets
for 2022 for the 1997 ozone NAAQS (shown in Table 4 of this document)
based on our conclusion that the updated budgets meet the applicable
transportation conformity and other CAA requirements.
If the EPA takes final action to approve the 2020 Ozone Maintenance
Plan Revision as proposed, the revised budgets will replace the
corresponding approved budgets from the 2018 Ozone Maintenance Plan
Revision, and RTC and DOT must use the revised budgets for future
transportation conformity determinations for the 2015 ozone NAAQS until
motor vehicle emissions budgets for that ozone NAAQS are found adequate
or are approved.\44\
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\44\ In addition, if we finalize this action as proposed, we
will be removing the conditional approval regulatory text found at
40 CFR 52.1475(a).
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The EPA is soliciting public comments on the issues discussed in
this document. We will accept comments from the public on this proposal
for the next 30 days. We will consider these comments before taking
final action.
VII. Statutory and Executive Order Reviews
Under the Clean Air Act, 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 Clean Air Act.
Accordingly, this proposed action merely proposes to approve a state
plan as meeting federal requirements and does not impose additional
requirements beyond those imposed by state law. For that reason, this
proposed 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 (Public Law 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 Clean Air Act; and
<bullet> Does not provide the EPA with the discretionary authority
to address disproportionate human health or environmental effects with
practical, appropriate, 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 the EPA or an Indian tribe
has demonstrated that a tribe has jurisdiction. The Las Vegas
[[Page 43469]]
Tribe of Paiute Indians of the Las Vegas Indian Colony has areas of
Indian country geographically located within the Clark County 1997
ozone maintenance area. 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, Intergovernmental regulations, Nitrogen dioxide, Ozone,
Reporting and recordkeeping requirements, Volatile organic compounds.
Authority: 42 U.S.C. 7401 et seq.
Dated: July 19, 2021.
Deborah Jordan,
Acting Regional Administrator, EPA Region IX.
[FR Doc. 2021-16644 Filed 8-6-21; 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.