Proposed Rule2024-25575
Air Plan Approval; Arizona; Yuma 2015 8-Hour Ozone Nonattainment Area; Redesignation Request and 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
November 5, 2024
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is proposing to approve the State of Arizona's request to redesignate the Yuma nonattainment area from nonattainment to attainment for the 8-hour national ambient air quality standards (NAAQS or "standard") for ozone promulgated in 2015 ("2015 ozone NAAQS"). The EPA is also proposing to approve the "SIP Revision: 2015 Ozone NAAQS, Yuma Redesignation Request and Maintenance Plan" ("Yuma Maintenance Plan" or "Plan") as a revision to the State Implementation Plan (SIP) for the State of Arizona. The Yuma Maintenance Plan includes, among other elements, an emissions inventory consistent with attainment, a maintenance demonstration, contingency provisions, and a motor vehicle emissions budget for the first ten-year maintenance period. With this proposed rulemaking, the EPA is beginning the adequacy process for the 2020, 2030, and 2037 motor vehicle emissions budgets. The EPA is proposing these actions because this SIP revision meets the applicable Clean Air Act (CAA or "the Act") requirements for maintenance plans and because the State has met the requirements under the Act for redesignation of a nonattainment area to attainment with respect to the Yuma 2015 ozone NAAQS nonattainment area ("Yuma area").
Full Text
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<title>Federal Register, Volume 89 Issue 214 (Tuesday, November 5, 2024)</title>
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[Federal Register Volume 89, Number 214 (Tuesday, November 5, 2024)]
[Proposed Rules]
[Pages 87828-87838]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-25575]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 52 and 81
[EPA-R09-OAR-2024-0339; FRL-12125-01-R9]
Air Plan Approval; Arizona; Yuma 2015 8-Hour Ozone Nonattainment
Area; Redesignation Request and Maintenance Plan
AGENCY: Environmental Protection Agency (EPA).
[[Page 87829]]
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
approve the State of Arizona's request to redesignate the Yuma
nonattainment area from nonattainment to attainment for the 8-hour
national ambient air quality standards (NAAQS or ``standard'') for
ozone promulgated in 2015 (``2015 ozone NAAQS''). The EPA is also
proposing to approve the ``SIP Revision: 2015 Ozone NAAQS, Yuma
Redesignation Request and Maintenance Plan'' (``Yuma Maintenance Plan''
or ``Plan'') as a revision to the State Implementation Plan (SIP) for
the State of Arizona. The Yuma Maintenance Plan includes, among other
elements, an emissions inventory consistent with attainment, a
maintenance demonstration, contingency provisions, and a motor vehicle
emissions budget for the first ten-year maintenance period. With this
proposed rulemaking, the EPA is beginning the adequacy process for the
2020, 2030, and 2037 motor vehicle emissions budgets. The EPA is
proposing these actions because this SIP revision meets the applicable
Clean Air Act (CAA or ``the Act'') requirements for maintenance plans
and because the State has met the requirements under the Act for
redesignation of a nonattainment area to attainment with respect to the
Yuma 2015 ozone NAAQS nonattainment area (``Yuma area'').
DATES: Written comments must arrive on or before December 5, 2024.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2024-0339 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 a disability
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: Andrew Ledezma, Planning and Analysis
Branch (AIR-2), Air and Radiation Division, EPA Region IX, 75 Hawthorne
Street, San Francisco, CA 94105, (415) 972-3985, or by email at
<a href="/cdn-cgi/l/email-protection#9ad6fffeffe0f7fbb4dbf4fee8ffeddaffeafbb4fdf5ec"><span class="__cf_email__" data-cfemail="08446d6c6d7265692649666c7a6d7f486d7869266f677e">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us,''
and ``our'' refer to the EPA.
Table of Contents
I. Background
A. The 2015 Ozone National Ambient Air Quality Standards
B. The Yuma Area and Regulatory Actions
C. CAA and Regulatory Requirements for Redesignations and
Maintenance Plans
II. Submissions From the State of Arizona To Redesignate the Yuma
Area to Attainment for the 2015 Ozone NAAQS
A. Summary of State Submissions
B. CAA Procedural Requirements for Adoption and Submission of
SIP Revisions
III. Evaluation of Arizona's Redesignation Request for the Yuma Area
A. Evaluation of Whether the Yuma Area Has Attained the 2015
Ozone NAAQS
B. The Area Must Have a Fully Approved SIP Meeting the
Requirements Applicable for the Purposes of Redesignation Under
Section 110 and Part D of the CAA
C. The Area Must Show That the Improvement in Air Quality Is Due
to Permanent and Enforceable Emissions Reductions
D. The Area Must Have a Fully Approved Maintenance Plan Under
CAA Section 175A
IV. Proposed Action and Request for Public Comment
V. Statutory and Executive Order Review
I. Background
A. The 2015 Ozone National Ambient Air Quality Standards
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 nonroad motor vehicles and engines, power plants and
industrial facilities, and smaller area sources such as lawn and garden
equipment and paints.
Scientific evidence indicates that adverse public health effects
occur following exposure to ozone, particularly in children and adults
with lung disease. Breathing air containing ozone can reduce lung
function and inflame airways, which can increase respiratory symptoms
and aggravate asthma or other lung diseases.\1\
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\1\ ``Fact Sheet--2008 Final Revisions to the National Ambient
Air Quality Standards for Ozone,'' dated March 2008.
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Under section 109 of the Act, the EPA promulgates NAAQS for
pervasive air pollutants, such as ozone. The NAAQS are concentration
levels the EPA has determined to be requisite to protect public health
and welfare. On February 8, 1979, the EPA established primary and
secondary NAAQS for ozone at 0.12 parts per million (ppm) averaged over
a 1-hour period.\2\ On July 18, 1997, the EPA revised the primary and
secondary standards for ozone to set the acceptable level of ozone in
the ambient air at 0.080 ppm averaged over an 8-hour period (``1997
ozone NAAQS'').\3\
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\2\ See 44 FR 8202 (February 8, 1979).
\3\ See 62 FR 38856. On April 30, 2004, the EPA designated and
classified areas of the country with respect to the 1997 ozone
NAAQS. See 69 FR 23858.
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In 2008, the EPA lowered the 8-hour ozone NAAQS to 0.075 ppm
(``2008 ozone NAAQS'') to revise the 1997 ozone NAAQS.\4\ Then, in
2015, the EPA lowered the primary and secondary 8-hour ozone NAAQS to
0.070 ppm (``2015 ozone NAAQS'' or ``standard'' \5\).\6\ Most recently,
in December 2020, the EPA finalized review of the ozone NAAQS,
retaining the form and level of the standards.\7\ As a result, no new
ozone area designations were triggered under the CAA, and therefore, no
new nonattainment area requirements will apply. This action pertains to
only the 2015 ozone NAAQS.
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\4\ 73 FR 16436 (March 27, 2008).
\5\ Since the primary and secondary 2015 ozone standards are the
same, we hereafter refer to them herein using the singular ``2015
ozone NAAQS'' or ``standard.''
\6\ 80 FR 65292 (October 26, 2015).
\7\ 85 FR 87256 (December 31, 2020). This proposed action
relates to the requirements for the 2015 ozone NAAQS. Information
regarding the December 31, 2020 retention of the prior 2015 ozone
NAAQS is provided for reference only.
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B. The Yuma Area and Regulatory Actions
Following promulgation of a new or revised NAAQS, the EPA is
required by the CAA to promulgate designations for areas throughout the
U.S. in accordance with section 107(a)(1) of the CAA. Effective August
3, 2018, the EPA
[[Page 87830]]
established the initial air quality designations for most areas in the
United States for the 2015 ozone NAAQS.\8\ The EPA designated the Yuma
area as ``Marginal'' nonattainment for the 2015 ozone NAAQS based on
monitoring data from 2014-2016. Areas classified as Marginal must
attain the NAAQS within three years of the effective date of the
nonattainment designation.\9\ The Yuma area covers 52 square miles in
the Sonoran Desert region of southwestern Arizona and is adjacent to
California and the international border with Mexico.\10\ In response to
the designation and classification of the Yuma area as a Marginal area,
Arizona submitted to the EPA revisions to its nonattainment new source
review (NNSR) program. The EPA approved the revisions and determined
that the NNSR program meets the applicable NNSR program requirements
for areas classified as Marginal nonattainment for the 2015 ozone
NAAQS.\11\ Arizona also submitted a plan titled ``Marginal Ozone Plan
for the Yuma Nonattainment Area'' and a technical supplement which
address the emissions inventory requirement in CAA section 182(a)(1)
and the emissions statement requirement in CAA section 182(a)(3). The
EPA approved the emissions inventory for the Yuma area on April 5,
2022,\12\ and the emissions statement on July 29, 2022.\13\
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\8\ 83 FR 25776 (June 4, 2018).
\9\ CAA section 181(a)(1), 40 CFR 51.1102 and 51.1103(a).
\10\ The Yuma nonattainment area is bounded on the north and
west by the Arizona state line, bounded on the south by the line of
latitude at 32[deg]39'20'' N, bounded on the east by the line of
longitude 114[deg]33'50'' W, and excluding the section 10, 11, and
12 of township T9S, R23W and any portion in Indian Country. See 40
CFR 81.303.
\11\ 89 FR 22963 (April 3, 2024).
\12\ 87 FR 19629 (April 5, 2022).
\13\ 87 FR 45657 (July 29, 2022).
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On October 7, 2022, the EPA determined that the Yuma area attained
the 2015 ozone NAAQS by August 3, 2021, the attainment deadline
specified by the Act, with a design value of 0.068 ppm.\14\ The EPA
relied on 2018-2020 quality-assured, certified ambient ozone data in
making the determination that the Yuma area had attained the NAAQS by
the applicable date.
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\14\ 87 FR 60897 (October 7, 2022). The design value for the
2015 ozone NAAQS is the fourth-highest daily maximum 8-hour average
concentration of ozone averaged over a three-year period. 40 CFR
part 50, appendix U.
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C. CAA and Regulatory Requirements for Redesignations and Maintenance
Plans
The CAA establishes the criteria that must be met for the EPA to
redesignate a nonattainment area to attainment for a given NAAQS.
Specifically, section 107(d)(3)(E) sets forth the following criteria:
(1) the EPA must determine that the area has attained the applicable
NAAQS; (2) the EPA must have a fully approved SIP for the area under
CAA section 110(k); (3) the EPA must determine that the improvement in
air quality is due to permanent and enforceable reductions in
emissions; (4) the EPA must have fully approved a maintenance plan for
the area as meeting the requirements of CAA section 175A; and, (5) the
State must have met all requirements applicable to the area under
section 110 and title I, part D (``part D'') of the CAA. Section 110
identifies a comprehensive list of elements that must be included in
SIPs, and part D establishes the SIP requirements for nonattainment
areas. Part D is divided into six subparts. The generally applicable
SIP requirements for nonattainment areas are found in subpart 1 of part
D, and the ozone-specific SIP requirements are found in subpart 2 of
part D. The EPA provided guidance on redesignations in a document
titled ``State Implementation Plans; General Preamble for the
Implementation of title I of the Clean Air Act Amendments of 1990,''
published in the Federal Register on April 16, 1992,\15\ and
supplemented on April 28, 1992 \16\ (collectively referred to herein as
the ``General Preamble''). The EPA issued additional guidance in two
memoranda: a September 4, 1992 memorandum from John Calcagni, titled
``Procedures for Processing Requests to Redesignate Areas to
Attainment'' (``Calcagni memo''); \17\ and a 1995 memorandum from Mary
D. Nichols, titled ``Part D New Source Review (part D NSR) Requirements
for Areas Requesting Redesignation to Attainment'' (``Nichols
memo'').\18\
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\15\ 57 FR 13498 (April 16, 1992).
\16\ 57 FR 18070 (April 28, 1992).
\17\ Memorandum dated September 4, 1992, from John Calcagni, Air
Quality Management Division, U.S. EPA, to Regional Air Directors,
Regions I-X, Subject: ``Procedures for Processing Requests to
Redesignate Areas to Attainment,'' available at <a href="https://www.epa.gov/sites/default/files/2016-03/documents/calcagni_memo_-_procedures_for_processing_requests_to_redesignate_areas_to_attainment_090492.pdf">https://www.epa.gov/sites/default/files/2016-03/documents/calcagni_memo_-_procedures_for_processing_requests_to_redesignate_areas_to_attainment_090492.pdf</a>.
\18\ Memorandum dated October 14, 1994, from Mary D. Nichols,
Assistant Administrator, U.S. EPA, to EPA Regional Air Directors,
Region I-X, Subject: ``Part D New Source Review (part D NSR)
Requirements for Areas Requesting Redesignation to Attainment,''
available at <a href="https://www.epa.gov/sites/default/files/2015-07/documents/101494m.pdf">https://www.epa.gov/sites/default/files/2015-07/documents/101494m.pdf</a>.
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The EPA's approval of a State's maintenance plan is one of the CAA
prerequisites for redesignation of a nonattainment area to attainment.
Section 175A of the CAA provides the general framework for a State's
maintenance plans. A State's initial 10-year maintenance plan must
provide for maintenance of the NAAQS for at least 10 years after
redesignation and include any additional control measures necessary to
ensure such maintenance. In addition, maintenance plans must contain
contingency provisions necessary to assure the prompt correction of a
violation of the NAAQS during the maintenance period. At a minimum,
these contingency provisions must include a requirement that a State
will implement all control measures contained in the nonattainment SIP
prior to redesignation. Because a State's maintenance plan submittals
are SIP revisions, the EPA is obligated under CAA section 110(k) to
approve them or disapprove them depending upon whether they meet the
applicable CAA requirements for such plans outlined above.
For the reasons described in section III of this proposal, the EPA
is proposing to approve the Yuma Maintenance Plan and approve Arizona's
request for redesignation of the Yuma area to attainment for the 2015
ozone NAAQS. The EPA's proposed approvals are based on our conclusion
that Arizona has satisfied all the criteria under CAA section
107(d)(3)(E).
II. Submissions From the State of Arizona To Redesignate the Yuma Area
to Attainment for the 2015 Ozone NAAQS
A. Summary of State Submissions
On December 27, 2023, the Arizona Department of Environmental
Quality (ADEQ) submitted to the EPA its redesignation request and the
Yuma Maintenance Plan as a revision to the Arizona SIP.\19\ This
document addresses all of the CAA section 107(d)(3)(E) requirements for
redesignating a nonattainment area to attainment for the NAAQS and
includes the required maintenance plan elements. The Yuma Maintenance
Plan is organized into eight chapters and two appendices. Appendix A of
the Plan provides technical support for the emissions inventory, and
appendix B of the Plan contains the procedural requirements and
authority to implement the Yuma Maintenance Plan.
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\19\ Letter dated December 27, 2023, from Hether Krause, Deputy
Assistant Director, ADEQ, to Martha Guzman, Regional Administrator,
EPA Region IX.
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[[Page 87831]]
B. CAA Procedural Requirements for Adoption and Submission of SIP
Revisions
CAA sections 110(a) and 110(l) require a State to provide
reasonable public notice and opportunity for public hearing prior to
the adoption and submission of a SIP revision to the EPA. To meet this
procedural requirement, a State must include evidence that it provided
adequate public notice and an opportunity for a public hearing,
consistent with the EPA's implementing regulations in 40 CFR 51.102.
ADEQ's December 27, 2023 SIP submittal includes documentation of
the public process conducted by ADEQ in its adoption the Yuma
Maintenance Plan.\20\ On November 15, 2023, ADEQ released a draft
version of the plan for public review and published a notice of public
meeting to be held on December 15, 2023, to consider the adoption of
the Yuma Maintenance Plan. ADEQ adopted the Yuma Maintenance Plan on
December 15, 2023, following a public hearing, as documented in the
public hearing presiding officer certification \21\ and public hearing
transcript.\22\ Based on the documentation in the December 27, 2023 SIP
submittal, ADEQ has satisfied the applicable statutory and regulatory
requirements for reasonable public notice and hearing prior to adoption
and submission of the Plan. Therefore, the submission of the Yuma
Maintenance Plan meets the procedural requirements for public notice
and hearing in CAA sections 110(a) and 110(l) and in 40 CFR 51.102.
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\20\ ADEQ submitted a signed version of its ``Notice of Public
Hearing'' published online, and in print in The Arizona Republic on
November 14 and 15, 2023 and in the Yuma Sun on November 14, 2023.
\21\ ADEQ submitted a signed version of the ``Public hearing
presiding officer certification,'' which certifies that ADEQ
conducted public hearing on December 15, 2023.
\22\ ADEQ submitted a written transcript of the public hearing
conducted on December 15, 2023, in which the Yuma Maintenance Plan
was adopted.
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On June 23, 2024, the Yuma Maintenance Plan became complete by
operation of law pursuant to CAA section 110(k)(1)(B).\23\
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\23\ For more information regarding the completeness criteria as
per CAA section 110(k)(1)(A) and 40 CFR part 51, appendix V, see the
completeness checklist in the Yuma Maintenance Plan, v-viii.
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III. Evaluation of Arizona's Redesignation Request for the Yuma Area
A. Evaluation of Whether the Yuma Area Has Attained the 2015 Ozone
NAAQS
1. Statutory and Regulatory Requirements
Pursuant to section 107(d)(3)(E)(i) of the CAA, for a nonattainment
area to be redesignated to attainment, the EPA must determine that the
area has attained the relevant NAAQS. The EPA interprets this
requirement to mean that the area must have an attaining design value
based on the most recently available and quality-assured air quality
monitoring data, collected in accordance with the requirements of 40
CFR part 58.\24\ These requirements include quality assurance
procedures for monitor operation and data handling, siting parameters
for instruments or instrument probes, and minimum ambient air quality
monitoring network requirements.\25\ State, local, or Tribal agencies
that operate air monitoring sites in accordance with 40 CFR part 58
must enter the ambient air quality data from these sites in the EPA Air
Quality System (AQS) database.\26\ These monitoring agencies certify
annually that these data are accurate to the best of their knowledge,
taking into consideration the quality assurance findings.\27\
Accordingly, the EPA relies primarily on AQS data when determining the
attainment status of an area.
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\24\ 57 FR 13948 at 13563 (April 12, 1992).
\25\ 40 CFR 58.2(a).
\26\ 40 CFR 58.16. AQS is the EPA's national repository of
ambient air quality data.
\27\ 40 CFR 58.15(a).
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In accordance with 40 CFR part 50, appendix U, the EPA's finding of
attainment of the 2015 ozone NAAQS must be based upon complete,
certified data gathered at monitoring sites in the nonattainment area
in accordance with 40 CFR part 58 and entered into AQS.\28\ Under 40
CFR 50.19 and in accordance with part 50, appendix U, an area meets the
2015 ozone NAAQS when the design value at each eligible monitoring site
within the area is less than or equal to 0.070 ppm, based on the
calculations set forth in 40 CFR part 50, appendix U.\29\
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\28\ 40 CFR part 50, appendix U, section 3.
\29\ The 2015 ozone NAAQS design value is the annual fourth-
highest daily maximum 8-hour average ozone concentration, averaged
over three years.
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To have a valid design value showing attainment of the ozone
standard at a given monitoring site, the ambient air quality data must
meet data completeness or substitution requirements for each year under
consideration. The completeness requirements are met when at least 90
percent of the days in the ozone season are complete,\30\ on average,
for the three-year period, with a minimum of at least 75 percent of the
complete days within the ozone monitoring period in any one year.\31\
When computing whether the minimum data completeness requirements have
been met, meteorological or ambient data may be sufficient to
demonstrate that meteorological conditions on missing days were not
conducive to concentrations above the level of the 2015 ozone NAAQS.
Missing days assumed less than the level of the 2015 ozone NAAQS are
counted for the purpose of meeting the minimum data completeness
requirements, subject to the approval of the Regional
Administrator.\32\
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\30\ Ozone season refers to seasons of the year that are
conducive to ozone formation, identified on a state-by-state basis
per 40 CFR part 58, appendix D 4.1(i), table D-3. The Yuma
Maintenance Plan identifies their high ozone season as April to
September. Yuma Maintenance Plan, 9.
\31\ 40 CFR part 50, appendix U, section 4.b.
\32\ 40 CFR part 50, appendix U, section 4.c.
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2. Monitoring Network Review, Quality Assurance, and Data Completeness
ADEQ is the governmental agency with the authority and
responsibilities under the State's laws for collecting ambient air
quality data in the Yuma area. As a result, ADEQ submits annual
monitoring network plans to the EPA.\33\ These plans document the
status of ADEQ's air monitoring network, as required under 40 CFR
58.10. The EPA reviews these annual network plans for compliance with
the specific requirements in 40 CFR part 58. With respect to ozone, we
have found that the annual network plans submitted by ADEQ met these
requirements under 40 CFR part 58, including the minimum monitoring
requirements.\34\ Yuma Supersite (AQS ID No. 04-027-8011) is the only
ozone monitor in the Yuma area.
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\33\ We have included in the docket for this rulemaking, EPA
reviews of ADEQ annual network plans and the correspondence
transmitting this review, e.g., from Dena Vallano, Manager,
Monitoring and Analysis Section, EPA Region IX, to Daniel
Czecholinski, Air Division Director, ADEQ.
\34\ See e.g., ``Arizona Air Monitoring Network Plan for the
Year 2023,'' Tables 2.1-10 and 2.1-11, ``Minimum Monitoring
Requirements for O3.''
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In accordance with 40 CFR 58.15, ADEQ certifies annually that the
previous years' ambient concentration and quality assurance data are
completely submitted to AQS and that
[[Page 87832]]
the ambient concentration data are accurate, taking into consideration
the quality assurance findings.\35\ Along with the certification
letters, ADEQ submits a summary of the precision and accuracy data for
all ambient air quality data.\36\ The EPA's evaluations of the relevant
quality assurance data are reflected in the associated AQS design value
reports.\37\ These reports include a certification evaluation and
concurrence (``Cert&Eval'') flag indicating the overall quality of the
corresponding monitoring data. Over the period of 2021-2023, the
associated Cert&Eval flag in the design value report was ``Y'' for the
monitoring site in the Yuma area,\38\ meaning that ``[t]he certifying
agency has submitted a certification letter, and EPA has no unresolved
reservations about data quality (after reviewing the letter, the
attached summary reports, the amount of quality assurance data
submitted to AQS, the quality statistics, and the highest reported
concentrations).'' \39\
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\35\ We have included in our docket ADEQ's annual data
certifications for 2020-2022. Annual data certification requirements
can be found at 40 CFR 58.15.
\36\ 40 CFR 58.15(c).
\37\ AQS, Design Value Report (AMP480), dated February 21, 2024.
\38\ In 2021, the one-point quality control check requirement
was not met. ADEQ did not complete the required number of checks
throughout the year. However, according to 40 CFR part 58, appendix
A, section 1.2.3, failure to conduct or pass a required check or
procedure, or a series of required checks or procedures, does not by
itself invalidate data for regulatory decision making.
\39\ AQS, Design Value Report (AMP480), dated February 21, 2024.
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The Yuma area Design Value Report also included a validity
indicator (``Y'') that reflects whether the design value is valid
(i.e., calculated using data that meet the applicable completeness
criteria). For the purposes of this proposal, we reviewed the data for
the 2021-2023 period for completeness and determined that the ozone
data collected by ADEQ met the completeness criterion at the ozone
monitoring site in the Yuma area.\40\
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\40\ Id.
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Finally, the EPA conducts regular technical system audits (TSAs)
where we review and inspect State and local ambient air monitoring
programs to assess compliance with applicable regulations concerning
the collection, analysis, validation, and reporting of ambient air
quality data. For the purposes of this proposal, we reviewed the
findings from the EPA's 2021 TSA of ADEQ's ambient air monitoring
program.\41\ In Finding 4 of the 2021 TSA, the EPA noted that ADEQ did
not report all valid measurement quality checks to AQS as required by
the CFR. ADEQ conducted nightly zero/precision/span checks on its ozone
analyzers with certified transfer standards but did not report these to
AQS. In the past, the rationale for not reporting these checks was that
the stability was not tracked or was questionable given the limited
time for the zero/precision/span to occur, (i.e., 11:45 p.m.-12:15
a.m.). To address this finding, as of October 2023, ADEQ has begun to
submit nightly ozone precision checks to AQS. The EPA did not recommend
invalidating any data from the monitoring site in the Yuma area based
on this TSA.
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\41\ Technical Systems Audit of the Ambient Air Monitoring
Program: Arizona Department of Environmental Quality, February 8-12,
2021; Final Report dated April 2022 (``2021 TSA''). The 2021 TSA is
attached to its transmittal letter dated April 7, 2022, from
Elizabeth J. Adams, EPA Region IX, to Bradley Busby, Manager, ADEQ.
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In summary, based on the EPA's reviews of the relevant monitoring
network plans, certifications, quality assurance data, and the 2021
TSA, we propose to find that the ozone data collected in the Yuma area
are suitable for determining whether the area has attained the 2015 8-
hour ozone NAAQS based on the most recent certified data available in
AQS.
3. Evaluation of Attainment
Table 1 shows the calculated 2015 ozone design values at the Yuma
Supersite monitor (AQS ID No. 04-027-8011). The data show that the
monitor in the Yuma area met the 2015 ozone NAAQS in the 2020-2022
period. In addition, preliminary data for 2024 shows that the Yuma
Supersite monitor is attaining the 2015 ozone NAAQS.\42\
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\42\ See ``AQS Quicklook Report,'' dated October 1, 2024,
available in the docket for this proposed rule. At the Yuma
Supersite, available data for 2024 on includes the first and second
quarter of the year (January through June). Based on that first and
second quarter, the fourth-highest 8-hour ozone concentration so far
in 2014 is 0.068 ppm.
Table 1--Yuma Supersite Monitor (AQS ID No. 04-027-8011) Design Value
for the 2015 Ozone NAAQS From 2008-2022
[Parts per million (ppm)] \a\
------------------------------------------------------------------------
Year Design value
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2010.................................................... 0.073
2011.................................................... 0.073
2012.................................................... 0.077
2013.................................................... 0.076
2014.................................................... 0.077
2015.................................................... 0.076
2016.................................................... 0.074
2017.................................................... 0.072
2018.................................................... 0.071
2019.................................................... 0.071
2020.................................................... 0.068
2021.................................................... 0.067
2022.................................................... 0.068
2023.................................................... 0.070
------------------------------------------------------------------------
\a\ Source: AQS, Design Value Report, dated May 1, 2024.
Consequently, based upon three complete, quality assured and
certified data from 2021-2023, the EPA proposes to determine that the
Yuma area has attained and continues to attain the 2015 ozone NAAQS.
B. The Area Must Have a Fully Approved SIP Meeting the Requirements
Applicable for the Purposes of Redesignation Under Section 110 and Part
D of the CAA
Sections 107(d)(3)(E)(ii) and (v) of the CAA require the EPA to
determine that the area has a fully approved applicable SIP under CAA
section 110(k) that meets all applicable requirements under section 110
and part D for the purposes of redesignation. We interpret the
references to the ``applicable implementation plan'' and ``applicable
requirements'' in section 107(d)(3)(E)(ii) and in 107(d)(3)(E)(v),
respectively, to mean that a SIP must be fully approved only with
respect to requirements that are applicable for purposes of
redesignation. The CAA section 110 and part D requirements that are
linked to a particular nonattainment area's designation and
classification (except those directly related to attainment) are the
relevant measures to evaluate in reviewing a redesignation request.
Requirements that apply regardless of the designation of an area of a
State are not applicable requirements for the purpose of redesignation,
and the State will remain subject to these requirements after the
nonattainment area is redesignated to attainment.\43\ The EPA may rely
on prior SIP approvals in
[[Page 87833]]
approving a redesignation request \44\ as well as any additional
measure or element it may approve in conjunction with a redesignation
action.\45\
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\43\ See the Calcagni memo; memorandum dated September 17, 1993,
from Michael Shapiro, Acting Assistant Administrator for Air and
Radiation, Subject: ``State Implementation Plan (SIP) Requirements
for Areas Submitting Requests for Redesignation to Attainment of the
Ozone and Carbon Monoxide (CO) National Ambient Air Quality
Standards (NAAQS) on or after November 15, 1992,''; 60 FR 12459,
12465-66 (March 7, 1995) (redesignation of Detroit-Ann Arbor,
Michigan); 68 FR 25418, 25424-25427 (May 12, 2003) (redesignation of
St. Louis, Missouri); and Sierra Club v. EPA, 375 F.3d 537, 541 (7th
Cir. 2004) (upholding EPA's redesignation rulemaking applying this
interpretation).
\44\ Calcagni memo, 3; Wall v. EPA, 265 F.3d 426, 438 (6th Cir.
2001).
\45\ Calcangi memo, 3; 68 FR 25418, 25426 (May 12, 2003).
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1. State Implementation Plan Requirements Under Section 110
The general SIP elements and requirements set forth in CAA section
110(a)(2) include, but are not limited to, the following: (1) submittal
of a SIP that has been adopted by the State after reasonable public
notice and hearing; (2) provisions for establishment and operation of
appropriate procedures needed to monitor ambient air quality; (3)
implementation of a source permitting program; (4) provisions for the
implementation of part C requirements for prevention of significant
deterioration (PSD); (5) provisions for the implementation of part D
requirements for nonattainment new source review permit programs; (6)
provisions for air pollution modeling; and (7) provisions for public
and local agency participation in planning and emission control rule
development.
On numerous occasions, Arizona has submitted, and the EPA has
approved provisions addressing the basic CAA section 110 provisions.
The Arizona SIP contains enforceable emissions limitations, requires
monitoring, compiling, and analyzing of ambient air quality data;
requires preconstruction review of new or modified stationary sources;
provides for adequate funding, staff, and associated resources
necessary to implement its requirements; and provides the necessary
assurances that the State maintains responsibility for ensuring that
the CAA requirements are satisfied in the event that local or regional
agencies are unable to meet their CAA obligations. Most recently, on
September 4, 2024, the EPA finalized a partial approval and partial
disapproval of SIP revisions submitted by the State of Arizona with
respect to the requirements of CAA section 110(a)(2) for the 2015 ozone
NAAQS.\46\ Specifically, the EPA partially disapproved the SIP
revisions for CAA requirements in sections 110(a)(2)(C) (program for
enforcement of control measures and regulation of new stationary
sources), 110(a)(2)(D)(i)(II) (interference with maintenance of the
NAAQS in any other State, or ``prong 3''), 110(a)(2)(D)(ii) (interstate
pollution abatement, CAA section 126), and 110(a)(2)(J) (PSD and
visibility protection). The deficiencies are adequately addressed by
existing Federal implementation plans.
---------------------------------------------------------------------------
\46\ 89 FR 71830 (September 4, 2024).
---------------------------------------------------------------------------
In conclusion, we find that there are no outstanding or disapproved
applicable SIP submittals that prevent redesignation of the Yuma area
for the 2015 ozone NAAQS. Therefore, we propose to conclude that the
State has met all SIP requirements for the Yuma area that are
applicable for purposes of redesignation under section 110 of the CAA.
2. State Implementation Plan Requirements Under Part D
Part D of the CAA establishes the plan requirements for
nonattainment areas. Section 172(c) in subpart 1 of part D sets forth
the basic requirements of air quality plans for States with
nonattainment areas that are required to submit plans on a schedule
pursuant to CAA section 172(b). Subpart 2 of part D, which includes
section 182 of the CAA, establishes specific requirements for ozone
nonattainment areas depending on the areas' nonattainment
classifications. The Yuma area is classified as Marginal nonattainment
for the 2015 ozone NAAQS, and thus, the area is subject to the subpart
1 requirements contained in CAA sections 172(c) and 176, as well as CAA
section 182(c). A thorough discussion of the requirements contained in
sections 172(c) and 182(c) can be found in the ``General Preamble for
Implementation of Title I of the Clean Air Act Amendments of 1990.''
\47\
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\47\ 57 FR 13498 (April 16, 1992).
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CAA requirements for ozone nonattainment areas are cumulative in
that ``Extreme'' areas must also meet the applicable requirements for
the four lesser classifications: Marginal, ``Moderate,'' ``Serious,''
and ``Severe.'' Because the Yuma area was classified as Marginal
nonattainment for ozone, the area is only required to meet the
applicable Marginal ozone requirements.\48\ Since its classification as
a Marginal nonattainment area, the State has adopted and the EPA has
approved into the Arizona SIP the following Marginal area requirements
for the Yuma area with respect to the 2015 ozone NAAQS: emissions
inventories,\49\ emissions statements,\50\ and nonattainment new source
review programs.\51\
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\48\ The requirements can be found in CAA section 182(a).
\49\ 87 FR 19629 (April 5, 2022).
\50\ 87 FR 45657 (July 29, 2022).
\51\ 89 FR 22963 (April 3, 2024).
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In conclusion, we find that the Yuma area has a fully approved SIP
under CAA section 110(k) that satisfies the criterion for redesignation
under sections 107(d)(3)(E)(ii) and (v) of the CAA.
C. The Area Must Show That the Improvement in Air Quality Is Due to
Permanent and Enforceable Emissions Reductions
To approve a redesignation to attainment, section 107(d)(3)(E)(iii)
of the CAA requires the EPA to determine that the improvement in air
quality is due to emissions reductions that are permanent and
enforceable, and that the improvement results from the implementation
of the applicable SIP, applicable Federal air pollution control
regulations, and other permanent and enforceable regulations. Under
this criterion, a State must be able to reasonably attribute the
improvement in air quality to permanent and enforceable emissions
reductions. Attainment resulting from temporary reductions in emissions
(e.g., reduced production or shutdown due to temporary adverse economic
conditions) or unusually favorable meteorology would not qualify as an
air quality improvement due to permanent and enforceable emissions
reductions.\52\
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\52\ Calcagni memo, 4.
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ADEQ found that the Yuma area has demonstrated that the observed
air quality improvements with respect to the 2015 ozone NAAQS are due
to enforceable emissions reductions through the implementation of
Federal vehicle standards, engine standards, and rules for boilers,
reciprocating internal combustion engines, and electrical utility
generation units. ADEQ found that, within the Yuma area, Federal
regulations have been the primary measures contributing to permanent
and enforceable emissions reductions, leading to attainment of the
NAAQS.\53\
---------------------------------------------------------------------------
\53\ Yuma Maintenance Plan, 28-32.
---------------------------------------------------------------------------
The Federal motor vehicle program and Federal fuel standards for
sulfur content in diesel have contributed to attainment of the 2015
ozone NAAQS in the Yuma area by reducing VOC and NO<INF>X</INF>.\54\
Federal tier 2 and 3 motor vehicle standards implemented from 2004 to
2014 helped to reduce on-road mobile source VOC and NO<INF>X</INF>
emissions in the Yuma area through increasingly stringent emissions
standards. Federal sulfur content standards for diesel fuel were
implemented in conjunction with the Federal motor vehicle program
standards. Sulfur occurs naturally in gasoline and interferes with the
operation of catalytic converters on vehicles, which results in higher
NO<INF>X</INF>
[[Page 87834]]
emissions. Lower sulfur content fuel has reduced sulfur dioxide
(SO<INF>2</INF>) emissions and allowed pollution control equipment to
operate more effectively to reduce emissions of other pollutants as
well.
---------------------------------------------------------------------------
\54\ Yuma Maintenance Plan, 28-31.
---------------------------------------------------------------------------
Federal nonroad and stationary standards also contributed to
attainment of the 2015 ozone NAAQS. Nonroad spark-ignition and
recreational engine standards implemented between 2003 and 2020 have
contributed to a 72 percent reduction in VOCs and an 80 percent
reduction in NO<INF>X</INF>.\55\ The boiler and reciprocating internal
combustion engines national emissions standards for hazardous air
pollutants (NESHAPs), as well as the utility mercury and air toxics
standards (MATS) and new source performance standards (NSPS) rules for
electricity generating units also have contributed to VOC and
NO<INF>X</INF> reductions in the Yuma area.\56\ Taken together, these
Federal programs contributed to VOC and NO<INF>X</INF> emissions
reductions in the Yuma area.
---------------------------------------------------------------------------
\55\ Id.
\56\ Id.
---------------------------------------------------------------------------
With respect to the connection between the emissions reductions and
the improvement in air quality, we also conclude that the air quality
improvement in the Yuma area is due to permanent and enforceable
emissions reductions and not the result of temporary or impermanent
factors such as local economic downturn, temporary emissions
reductions, or unusual or extreme weather patterns. Our conclusion is
based on the observation that the ozone design value for the Yuma area
has been below 0.070 ppm, the level of the 2015 ozone NAAQS, since
2020.\57\ In sum, ambient ozone concentrations in the Yuma area have
been consistently below the NAAQS since 2020 and have not been subject
to large swings and disparate observations that might result from a
sudden facility closure or an extreme weather pattern.
---------------------------------------------------------------------------
\57\ Yuma Maintenance Plan, Figure 2-2.
---------------------------------------------------------------------------
In conclusion, we find that the improvement in ambient air quality
in the Yuma area is due to permanent and enforceable reductions in
emissions of VOC and NO<INF>X</INF>, resulting from control measures
such as (1) Federal vehicle standards and (2) stationary source control
measures. Therefore, we propose to find that Arizona has satisfied the
criterion for redesignation set forth at CAA section 107(d)(3)(E)(iii).
D. The Area Must Have a Fully Approved Maintenance Plan Under CAA
Section 175A
Section 107(d)(3)(E)(iv) of the CAA requires, as a pre-condition to
being redesignated from nonattainment to attainment, that the
Administrator has fully approved a maintenance plan for the area as
meeting the requirements of section 175A of the Act.
Section 175A of the CAA sets forth the elements of a maintenance
plan for areas seeking redesignation from nonattainment to attainment.
The maintenance plan is a SIP revision that provides for maintenance of
the relevant NAAQS in the area for at least 10 years after
redesignation. The Calcagni memo, dated September 4, 1992, provides
additional guidance on the required content of a maintenance plan.
A maintenance plan should address the following five areas: the
attainment emissions inventory, maintenance demonstration, monitoring
network, verification of continued attainment, and a contingency plan.
The attainment emissions inventory identifies the emissions level in
the area that is sufficient to attain the 2015 ozone NAAQS based on
emissions during a three-year period which had no monitored violations.
To demonstrate maintenance of the 2015 ozone NAAQS, ADEQ has projected
the attainment emissions inventory through the first maintenance period
and ensured that it was less than or equal to the inventory at the time
of attainment. A maintenance plan must also include provisions for
continued operation of an appropriate air quality monitoring network.
The State must show how it will track and verify the progress of the
maintenance plan. Finally, the maintenance plan must include a list of
potential contingency measures which ensure prompt correction of any
violation of the 2015 ozone NAAQS. Based on our review and evaluation
of the Yuma Maintenance Plan, as described in the following sections,
we are proposing to approve the Plan as meeting the requirements of CAA
section 175A.
1. Attainment Inventories and Projected Future Inventories
A maintenance plan should include an ``attainment emissions
inventory'' of ozone precursors in the area to identify a level of
emissions sufficient to attain the NAAQS.\58\ The attainment emissions
inventory should be consistent with the EPA's most recent guidance on
emissions inventories for nonattainment areas available at the time it
was developed and should represent emissions during the timeframe
associated with the ambient air quality monitoring data showing
attainment of the NAAQS. The attainment inventory will generally be the
actual inventory during the time period that the area attained the
standard. The EPA has provided guidance for developing ozone emissions
inventories in ``Emissions Inventory Guidance for Implementation of
Ozone and Particulate Matter National Ambient Air Quality Standards
(NAAQS) and Regional Haze Regulations''.\59\
---------------------------------------------------------------------------
\58\ Calcagni memo, 8-9.
\59\ ``Emissions Inventory Guidance for Implementation of Ozone
and Particulate Matter National Ambient Air Quality Standards and
Regional Haze Regulations,'' EPA-454/B-17-002, May 2017.
---------------------------------------------------------------------------
ADEQ selected 2020 as the base year for the attainment inventory in
the Yuma Maintenance Plan. The Yuma area attained the 2015 ozone NAAQS
in 2020, and therefore, the emissions inventory from 2020 represents
emissions levels consistent with continued attainment (i.e.,
maintenance) of the NAAQS. We consider the selection of the 2020 base
year inventory to be appropriate given that it was the most recent
emissions inventory associated with the reporting schedule required
under the Air Emissions Reporting Requirements rule at the time of
development of the Plan.
Table 2 presents the VOC and NO<INF>X</INF> emissions estimates
contained in the Yuma Maintenance Plan for 2020 and presents the Plan's
projected emissions inventories of ozone precursors for an interim year
(2030) and the maintenance plan's horizon year (2037).\60\
---------------------------------------------------------------------------
\60\ The maintenance plan horizon year refers to the final year
of the maintenance period covered by the plan.
[[Page 87835]]
Table 2--Yuma Area 2020 and Projected 2030 and 2037 VOC and NOX Ozone Season Day Emissions
[Pounds per day] \a\
--------------------------------------------------------------------------------------------------------------------------------------------------------
2020 2030 2037
Emissions source -----------------------------------------------------------------------------------------------
VOC NOX VOC NOX VOC NOX
--------------------------------------------------------------------------------------------------------------------------------------------------------
Point................................................... 104 1,662 1,384 4,628 1,384 4,628
Nonpoint................................................ 5,754 1,410 6,281 1,556 6,738 1,660
Mobile--Nonroad......................................... 1,792 1,620 1,720 923 1,754 782
Mobile--On-road......................................... 8,939 5,412 4,908 2,747 4,222 2,390
-----------------------------------------------------------------------------------------------
Total \b\........................................... 16,589 10,104 14,293 9,854 14,098 9,460
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Source: Yuma Maintenance Plan, 43.
\b\ Emissions have been added to the Mobile--On-road emissions source category to account for safety margins added to proposed motor vehicle emissions
budget. See the Yuma Maintenance Plan, page 50.
The data shown in Table 3 in this document is based on the EPA's
2020 national emissions inventory (NEI). The inventory addresses point
sources,\61\ nonpoint sources,\62\ nonroad mobile sources,\63\ and on-
road mobile sources. Appendix A to the Yuma Maintenance Plan contains
source-specific descriptions of emissions calculation procedures and
sources of input data.
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\61\ For the Yuma Maintenance Plan, ``point sources'' include
rock crusher/screener plants, electricity generation facilities,
paper mills, gas filling stations, and vapor extraction units.
\62\ For the Yuma Maintenance Plan, ``nonpoint sources'' include
biogenic emissions, dry cleaning, surface coating, residential and
industrial fuel combustion, and open burning.
\63\ For the Yuma Maintenance Plan, ``Mobile--Nonroad sources''
includes agricultural, commercial, lawn and garden, pleasure craft,
railroad, and recreational nonroad mobile sources.
---------------------------------------------------------------------------
The EPA has reviewed the emissions inventory submitted by ADEQ and
proposes to conclude that the Plan's inventory is based on reasonable
assumptions and methodologies, and that the inventory is comprehensive,
current, accurate, and consistent with applicable CAA provisions and
the Calcagni memo. Therefore, we are proposing that the inventory is
acceptable for use in demonstrating maintenance of the 2015 ozone
NAAQS.
2. Maintenance Demonstration
Section 175A(a) of the CAA requires that the maintenance plan
``provide for the maintenance of the national primary ambient air
quality standard for such air pollutant in the area concerned for at
least 10 years after the redesignation.'' A State may generally
demonstrate maintenance of the NAAQS by either showing that future
emissions of a pollutant or its precursors will not exceed the level of
the attainment inventory, or by conducting modeling that shows that the
future mix of sources and emissions rates will not cause a violation of
the NAAQS.\64\ Assumptions concerning emissions rates in maintenance
demonstrations should generally reflect permanent, enforceable
measures.\65\ Therefore, the analysis should assume that sources are
operating at permitted levels (or historic peak levels), unless
evidence is presented that such an assumption is unrealistic.\66\
---------------------------------------------------------------------------
\64\ Calcagni memo, 9-11.
\65\ Calcagni memo, 9.
\66\ Id. at 4. See also, memorandum dated November 30, 1993,
from Kent D. Berry, Acting Director, Air Quality Management
Division, EPA, Subject: ``Use of Actual Emissions in Maintenance
Demonstrations for Ozone and Carbon Monoxide (CO) Nonattainment
Areas.''
---------------------------------------------------------------------------
The Yuma Maintenance Plan demonstrates maintenance of the 2015
ozone NAAQS for a ten-year period beginning in 2027. ADEQ used the 2020
NEI and the Motor Vehicle Emission Simulator (MOVES) version 3.1 as the
baseline to develop growth factors for point, nonpoint, mobile on-road,
and mobile nonroad sources. For point sources, ADEQ used permitted
potential to emit (PTE) levels of emissions, except for the Arizona
Public Service (APS) Yucca Power Plant. ADEQ argues that, for the APS
Yucca Power Plant, permitted PTE is calculated by assuming the facility
would burn fuel oil at maximum capacity, overestimating emissions from
the facility. ADEQ argues that the facility runs primarily on natural
gas and burns little fuel oil each year.\67\ Therefore, ADEQ used
historic high emissions from 2018 for the baseline. We agree that this
method for estimating emissions from APS Yucca Power Plant is
consistent with EPA guidance. For nonpoint sources, ADEQ used the 2020
NEI held constant, or multiplied by a projection factor based on
population.\68\ ADEQ used MOVES 3.1 to model future on-road emissions,
using Arizona Department of Transportation vehicle registration data
and MOVES defaults.\69\ ADEQ used the EPA defaults for Yuma County and
applied a population allocation factor to apportion the county-wide
nonroad mobile source emissions to the Yuma nonattainment area. ADEQ
also used MOVES to model future nonroad mobile source emissions.
---------------------------------------------------------------------------
\67\ For the year 2018, the APS Yucca Power Plant utilized 99.3
percent natural gas and 0.7 percent fuel oil. For a demonstration
and justification for this estimation method, see the Yuma
Maintenance Plan, appendix A, section A8.1, A-54.
\68\ Yuma Maintenance Plan, appendix A, A-41, A-42.
\69\ Yuma Maintenance Plan, appendix A, A-42-A-50.
---------------------------------------------------------------------------
Table 2 compares the VOC and NO<INF>X</INF> emissions estimated for
the Yuma area for 2020 with those projected for 2030 and 2037 by source
category. The projected VOC and NO<INF>X</INF> emissions show that VOC
and NO<INF>X</INF> emissions are projected to remain below the
attainment levels throughout the 10-year period following
redesignation.
3. Monitoring Network
Once an area has been redesignated, the State should continue to
operate an appropriate air quality monitoring network in accordance
with 40 CFR part 58 to verify the attainment status of the area.\70\
Data collected by the monitoring network are also needed to determine
if the contingency provisions of the maintenance plan are triggered.
ADEQ currently operates one ozone monitor (the Yuma Supersite monitor)
in the Yuma area.
---------------------------------------------------------------------------
\70\ Calcagni memo, 11.
---------------------------------------------------------------------------
In the Yuma Maintenance Plan \71\ ADEQ indicates its intention to
continue operation of an air quality monitoring network to verify
continued attainment of the 2015 ozone NAAQS.\72\ We approved ADEQ's
State and Local Air Monitoring Stations (SLAMS) air quality network in
their annual monitoring network plan for year 2023
[[Page 87836]]
on October 30, 2023, prior to ADEQ's submittal of the Yuma Maintenance
Plan.\73\ We find ADEQ's commitment for continued ambient ozone
monitoring set forth in the Yuma Maintenance Plan to be acceptable for
the purpose of verifying continued maintenance in the Yuma area.
---------------------------------------------------------------------------
\71\ Yuma Maintenance Plan, 43.
\72\ Although the Yuma Maintenance Plan is not explicit in this
regard, we presume that ADEQ's intention to continue operation of a
monitoring network indicates the agency's intention to do so
consistent with the EPA's monitoring requirements in 40 CFR part 58
(``Ambient Air Quality Surveillance'').
\73\ The EPA's requirements for annual review of monitoring
networks are no longer codified at 40 CFR 58.20(d) but are now found
at 40 CFR 58.10.
---------------------------------------------------------------------------
4. Verification of Continued Attainment
Each State should ensure that it has the legal authority to
implement and enforce all measures necessary to maintain the NAAQS.\74\
---------------------------------------------------------------------------
\74\ Calcagni memo, 11.
---------------------------------------------------------------------------
ADEQ has the legal authority to implement and enforce the
requirements of the Yuma Maintenance Plan under title 49 of the Arizona
Revised Statutes, ``The Environment.'' This includes the authority to
adopt, implement, and enforce any emissions control contingency
measures determined to be necessary to correct 2015 ozone NAAQS
violations. To verify continued attainment, ADEQ committed to the
continued operation of an ozone monitoring network that meets the EPA
air quality surveillance requirements. In addition, ADEQ committed to
track the progress of the maintenance plan through continued
development and submission of periodic emissions inventories to the EPA
and review of the inventory to determine whether changes could affect
maintenance of the 2015 ozone NAAQS. These methods are sufficient for
the purpose of verifying continued attainment.
5. Contingency Provisions
Section 175A(d) of the CAA requires that maintenance plans contain
contingency provisions, as the EPA deems necessary, to promptly correct
any violations of the NAAQS that occur after redesignation of the area.
Such provisions must include a requirement that the State will
implement all measures with respect to the control of the air pollutant
concerned that were contained in the SIP prior to the area being
redesignated to attainment. These contingency provisions are
distinguished from contingency measures required for nonattainment
areas under CAA section 172(c)(9) in that they are not required to be
fully adopted measures that will take effect without further action by
the State for the maintenance plan to be approved. The contingency
provisions of a maintenance plan are, however, an enforceable part of
the SIP and should ensure that contingency measures are adopted
expeditiously once the Plan's contingency provisions are triggered by a
specified event. Thus, a State should identify the specific indicators
or triggers that will be used to determine when the contingency
measures need to be implemented. Next, the maintenance plan should
clearly identify the measures to be adopted, include a schedule and
procedure for adoption and implementation of the measures, and contain
a specific timeline for action by a State.
As required by section 175A of the CAA, ADEQ has adopted a
contingency plan to address possible future ozone air quality
problems.\75\ ADEQ identifies two triggers: a warning level response
and action level response. The warning level response would be
triggered if an annual 4th high monitored concentration is above the
level of the 2015 ozone NAAQS. This would initiate an analysis to
determine whether the high ozone concentrations indicate a trend
towards high ozone levels. The study would include an assessment of
meteorological conditions and an assessment of whether actual emissions
have deviated significantly from the emissions projections contained in
the maintenance plan, along with an evaluation of which source sectors
are responsible for emissions increases. The action level response
would be triggered if a certified design value exceeds the level of the
2015 ozone NAAQS. Within 18 months of the certified design value
exceedance, ADEQ commits to identify and implement necessary control
measures.
---------------------------------------------------------------------------
\75\ Yuma Maintenance Plan, 45-47.
---------------------------------------------------------------------------
Potential contingency measures listed in the maintenance plan are
those emissions controls or other measures that ADEQ may choose to
adopt and implement in response to the contingency trigger. The
contingency plan lists the following potential contingency provisions
that will be considered for adoption and implementation by the
applicable State agency, while the Plan indicates that the list is not
considered to be exhaustive:
<bullet> Anti-idling control program for mobile sources, targeting
diesel vehicles;
<bullet> Diesel exhaust retrofits;
<bullet> Traffic flow improvements;
<bullet> Park and ride facilities; and
<bullet> Rideshare/carpool program.
Upon our review of the Plan, we find that the contingency
provisions in the Yuma Maintenance Plan clearly identify specific
contingency measures, contain sufficient tracking and triggering
mechanisms to determine when contingency provisions are needed, contain
an adequate description of the process of recommending and implementing
contingency measures, and contain specific timelines for action. Thus,
we conclude that the contingency provisions of the Yuma Maintenance
Plan are adequate to ensure prompt correction of a violation and
therefore comply with section 175A(d) of the Act.
6. 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 expeditious attainment of the standards. Conformity to the
SIP's goals means that such actions will not: (1) cause or contribute
to violations of the NAAQS, (2) worsen the severity of an existing
violation, (3) or delay timely attainment of any NAAQS or any interim
milestone.
Actions involving Federal Highway Administration (FHWA) or Federal
Transit Administration (FTA) funding or approval are subject to the
EPA's transportation conformity rule, codified in 40 CFR part 93,
subpart A. Under this rule, regional transit authorities in
nonattainment and maintenance areas coordinate with State and local air
quality and transportation agencies, the EPA, FHWA, and FTA to
demonstrate that an area's regional transportation plans and
transportation improvement programs 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 motor vehicle emissions budgets (``budgets'') contained in
submitted or approved control strategy SIPs and maintenance plans.\76\
---------------------------------------------------------------------------
\76\ Control strategy SIPs refer to reasonable further progress
(RFP) and attainment demonstration SIPs. 40 CFR 93.101.
---------------------------------------------------------------------------
These control strategy SIPs and maintenance plans typically set
budgets for criteria pollutants and/or their precursors to address
pollution from cars and trucks. Budgets are generally established for
specific years and specific pollutants or precursors. Maintenance plan
submittals should identify budgets for transportation related VOC and
NO<INF>X</INF> emissions in the last year of the maintenance period.
For budgets in a maintenance plan to be approvable, they must meet,
at a minimum, the EPA's adequacy criteria.\77\ To meet these
requirements,
[[Page 87837]]
the budgets must be consistent, when considered with emissions from all
other sources, with maintenance of the NAAQS and reflect all the motor
vehicle control measures relied upon for the maintenance demonstration.
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
budgets during a public comment period; and (3) making a finding of
adequacy. The process for determining the adequacy of a submitted
budget is codified at 40 CFR 93.118(f). The EPA can notify the public
by either posting an announcement that the EPA has received SIP budgets
on the EPA's adequacy website,\78\ or via a Federal Register notice of
proposed rulemaking when the EPA reviews the adequacy of a maintenance
plan budget simultaneously with its review and action on the SIP
submittal itself.\79\
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\77\ 40 CFR 93.118(e)(4) and (5). For more information on the
transportation conformity requirement and applicable policies on
budgets, which can be found at <a href="https://www.ecfr.gov/current/title-40/chapter-I/subchapter-C/part-93">https://www.ecfr.gov/current/title-40/chapter-I/subchapter-C/part-93</a>.
\78\ See the EPA adequacy website: <a href="https://www.epa.gov/state-and-local-transportation/state-implementation-plans-sip-submissions-currently-under-epa">https://www.epa.gov/state-and-local-transportation/state-implementation-plans-sip-submissions-currently-under-epa</a>.
\79\ See the EPA memorandum dated July 15, 2024, titled:
``Adequacy Documentation for Motor Vehicle Emissions Budgets in the
Yuma Maintenance Plan.''
---------------------------------------------------------------------------
The Yuma Maintenance Plan contains VOC and NO<INF>X</INF> budgets
for 2020, 2030, and 2037. Any and all comments on the approvability of
the budgets should be submitted during the comment period stated in the
Dates section of this document.
The EPA proposes to approve the 2020, 2030, and 2037 budgets in the
Yuma Maintenance Plan for transportation conformity purposes. If the
EPA issues a final action to approve the budgets, these budgets must be
used in future transportation conformity determinations for the Yuma
area for the 2015 ozone standard.
The new budgets, if approved in the final rulemaking, will be
effective on the date of publication of the EPA's final rulemaking in
the Federal Register. The applicable VOC and NO<INF>X</INF> budgets for
the Yuma nonattainment area are defined in Table 3.
Table 3--Proposed Motor Vehicle Emissions Budgets for the Yuma Area
[Pounds per ozone season day]
------------------------------------------------------------------------
Budget year VOC NOX
------------------------------------------------------------------------
2020.................................................. 8,939 5,412
2030.................................................. 4,908 2,747
2037.................................................. 4,222 2,390
------------------------------------------------------------------------
Source: Yuma Maintenance Plan, Table 7-1.
The budgets are the on-road mobile source VOC and NO<INF>X</INF>
emissions for the Yuma area for 2020, 2030, and 2037. The budgets are
compatible with the 2020, 2030, and 2037 on-road mobile source VOC and
NO<INF>X</INF> emissions included in Yuma's 2020, 2030 and 2037
emissions inventories, as summarized in Table 2. The derivation of the
budget is thoroughly discussed in appendix A to the Yuma Maintenance
Plan.
We evaluated the budgets against our adequacy criteria in 40 CFR
93.118(e)(4) and (5) as part of our review of the budget's
approvability and expect to complete the adequacy review of the budgets
concurrent with our final action on the Yuma Maintenance Plan. The EPA
is not required under its transportation conformity rule to find
budgets adequate prior to proposing approval of them. In this notice,
the EPA is announcing that the adequacy process for these budgets
begins, and the public has 30 days to comment on their adequacy, per
the transportation conformity rule at 40 CFR 93.118(f)(2)(i) and (ii).
ADEQ developed budgets for 2020, 2030 and 2037 using on-road motor
vehicle emission estimates using the EPA's MOVES3 model fleet data from
Arizona Motor Vehicle Division registration data, and travel demand
modeling from the Yuma Metropolitan Planning Organization (YMPO). As
documented in a separate memorandum \80\ included in the docket for
this rulemaking, we preliminarily conclude that the budgets in the Yuma
Maintenance Plan meet each adequacy criterion. While adequacy and
approval are two separate actions, reviewing the budgets in terms of
the adequacy criteria informs the EPA's decision to propose to approve
the budgets. We have completed our detailed review and are proposing to
approve the demonstration of maintenance for the 2015 ozone area
through the year 2037. We have also reviewed the budgets in the Yuma
Maintenance Plan and found that they are consistent with the
maintenance demonstration for which we are proposing approval, are
clearly identified and precisely quantified, 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 93.118(e)(4) and (5). The EPA is proposing
to approve the budgets for 2020, 2030, and 2037 as part of our approval
of the Yuma Maintenance Plan. Once the EPA finalizes the adequacy
process or approves the budgets as proposed (whichever occurs first,
noting that finalization of the adequacy process and approval of the
budgets may also occur concurrently per 40 CFR 93.118(f)(2)(iii)), the
budgets must be used by YMPO for transportation conformity
determinations for the Yuma area.
---------------------------------------------------------------------------
\80\ See the EPA memorandum dated July 15, 2024, titled:
``Adequacy Documentation for Motor Vehicle Emissions Budgets in the
Yuma Maintenance Plan.''
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IV. Proposed Action and Request for Public Comment
Under CAA section 110(k)(3), and for the reasons set forth in this
document, the EPA is proposing to approve the Yuma Maintenance Plan
submitted by ADEQ on December 27, 2023, as a revision to the Arizona
SIP,\81\ and to redesignate the Yuma nonattainment area to attainment
for the 2015 ozone NAAQS. We are proposing to approve the maintenance
demonstration and contingency provisions as meeting all applicable
requirements for maintenance plans and related contingency provisions
in CAA section 175A, and the budgets for 2020, 2030 and 2037 (shown in
Table 4) for transportation conformity purposes as we find they meet
all applicable criteria for such budgets including the adequacy
criteria under 40 CFR 93.118(e). We are soliciting comments on these
proposed actions. We will accept comments from the public for 30 days
following publication of this proposal in the Federal Register and will
consider any relevant comments before taking final action.
---------------------------------------------------------------------------
\81\ Yuma Maintenance Plan (submitted electronically December
27, 2023).
---------------------------------------------------------------------------
V. Statutory and Executive Order Review
Under the CAA, redesignation of an area to attainment and the
accompanying approval of a maintenance plan under section 107(d)(3)(E)
are actions that affect the status of a geographical area and do not
impose any additional regulatory requirements on sources beyond those
imposed by State law. A redesignation to attainment does not in and of
itself create any new requirements, but rather results in the
applicability of requirements contained in the CAA for areas that have
been redesignated to attainment. Moreover, the Administrator is
required to approve a SIP submission that complies with the provisions
of the CAA 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
review State choices, and approve those choices if they meet
[[Page 87838]]
the criteria of the CAA. Accordingly, this action merely approves State
law 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 (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 Clean Air Act; and
<bullet> Will not have disproportionately high and adverse human
health or environmental effects on minority populations, low-income
populations and/or indigenous peoples, as specified in Executive Order
12898 (59 FR 7629, February 16, 1994), as discussed in section VI of
this proposal.
The EPA has identified Tribal areas within the Yuma area covered by
this rulemaking that would be potentially affected by this proposed
action. Specifically, the Cocopah Tribe of Arizona and the Quechan
Tribe of the Fort Yuma Indian Reservation are located within the
boundaries of the Yuma area.
The EPA has concluded that the final rule may have Tribal
implications for these tribes for the purposes of transportation
conformity only, as this document sets motor vehicle emissions budgets
for ozone precursors for the Yuma area, which includes some Tribal
roads. The EPA has communicated with the potentially affected tribes
located within the boundaries of the Yuma nonattainment area.\82\
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\82\ Letter dated June 4, 2024, from Matthew Lakin, Director,
EPA Region IX to Sherry Cordova, Chairwoman, Cocopah Tribe of
Arizona, Subject: ``Invitation to Consult on a Redesignation Request
and Maintenance Plan from the State of Arizona for the 2015 Ozone
National Ambient Air Quality Standards (NAAQS),'' and letter dated
June 4, 2024 from Matt Lakin, Director, EPA Region IX to Jordan
Joaquin, President, Quechan Tribe of the Fort Yuma Indian
Reservation, Subject: ``Invitation to Consult on a Redesignation
Request and Maintenance Plan from the State of Arizona for the 2015
Ozone National Ambient Air Quality Standards (NAAQS).''
---------------------------------------------------------------------------
Executive Order 12898 (Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations, 59 FR 7629,
Feb. 16, 1994) directs Federal agencies to identify and address
``disproportionately high and adverse human health or environmental
effects'' of their actions on communities with environmental justice
(EJ) concerns to the greatest extent practicable and permitted by law.
EPA defines EJ as ``the fair treatment and meaningful involvement of
all people regardless of race, color, national origin, or income with
respect to the development, implementation, and enforcement of
environmental laws, regulations, and policies.'' 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.''
The air agency did not evaluate environmental justice
considerations as part of its SIP submittal; the CAA and applicable
implementing regulations neither prohibit nor require such an
evaluation. EPA did not perform an EJ analysis and did not consider EJ
in this action. Due to the nature of the action being taken here, this
action is expected to have a neutral to positive impact on the air
quality of the affected area. Consideration of EJ is not required as
part of this action, and there is no information in the record
inconsistent with the stated goal of E.O. 12898 of achieving
environmental justice for communities with EJ concerns.
List of Subjects
40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Nitrogen dioxide, Reporting and recordkeeping requirements,
Sulfur Dioxide, Volatile organic compounds.
40 CFR Part 81
Environmental Protection, Air pollution control.
Authority: 42 U.S.C. 7401 et seq.
Dated: October 29, 2024.
Martha Guzman Aceves,
Regional Administrator, Region IX.
[FR Doc. 2024-25575 Filed 11-4-24; 8:45 am]
BILLING CODE 6560-50-P
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</html>Indexed from Federal Register on November 5, 2024.
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.