
[Federal Register Volume 88, Number 243 (Wednesday, December 20, 2023)]
[Proposed Rules]
[Pages 87988-88012]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-27686]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R09-OAR-2023-0477; FRL-11532-01-R9]


Clean Air Plans; Contingency Measures for the Fine Particulate 
Matter Standards; San Joaquin Valley, California

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve two state implementation plan (SIP) submissions under the Clean 
Air Act (CAA) that address the contingency measures requirements for 
the 1997 annual, 2006 24-hour, and 2012 annual fine particulate matter 
(PM2.5) national ambient air quality standards (NAAQS or 
``standards'') for the San Joaquin Valley PM2.5 
nonattainment area. The two SIP submissions include the area's 
contingency measure plan element and two specific contingency measures 
that would apply to residential wood burning heaters and fireplaces and 
non-agricultural, rural open areas. A third contingency measure, 
applicable to light-duty on-road motor vehicles, is the subject of a 
separate action by the EPA, but the related emissions reductions from 
the third measure are accounted for in this proposed rule. The EPA is 
proposing approval of the SIP submissions because the Agency has

[[Page 87989]]

determined that they are in accordance with the applicable requirements 
for such SIP submissions under the CAA and EPA implementation 
regulations for the PM2.5 NAAQS. The proposed approval, if 
finalized, would incorporate the two contingency measures into the 
federally enforceable SIP. The EPA will accept comments on this 
proposed rule during a 30-day public comment period.

DATES: Comments must be received by January 19, 2024.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2023-0477 at https://www.regulations.gov. For comments submitted at 
Regulations.gov, follow the online instructions for submitting 
comments. Once submitted, comments cannot be edited or removed from 
Regulations.gov. 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 (e.g., 
audio or video) 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 https://www.epa.gov/dockets/commenting-epa-dockets. 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: Rory Mays, Planning and Analysis 
Branch (AIR-2), Air and Radiation Division, EPA Region IX, 75 Hawthorne 
Street, San Francisco, CA 94105. By phone: (415) 972-3227 or by email 
at [email protected].

SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us,'' 
and ``our'' refer to the EPA.

Table of Contents

I. Background for Proposed Action
    A. Standards, Designations, Classifications, and Plans
    B. Findings and Contingency Measure Disapprovals
II. Summary of SIP Submissions and Evaluation for Compliance With 
SIP Revision Procedural Requirements
    A. Summary of SIP Submissions
    B. Evaluation for Compliance With SIP Revision Procedural 
Requirements
III. Contingency Measure Requirements, Guidance, and Legal Precedent
    A. Statutory and Regulatory Requirements
    B. Draft Revised Contingency Measure Guidance
IV. EPA Review of San Joaquin Valley Contingency Measures
    A. Residential Wood Burning Contingency Measure
    1. Background and Regulatory History
    2. Summary of State Submission
    3. EPA Evaluation
    B. Rural Open Areas Contingency Measure
    1. Background and Regulatory History
    2. Summary of State Submission
    3. EPA Evaluation
    C. Smog Check Contingency Measure
V. EPA Review of San Joaquin Valley PM2.5 Contingency 
Measure Plan Element
    A. Background and Regulatory History
    B. Summary of State Submission
    1. General Considerations
    2. Contingency Measure Feasibility Analyses
    3. Conclusion
    C. EPA Evaluation
    1. General Considerations
    2. Contingency Measure Feasibility Analyses
    3. Conclusion
VI. Environmental Justice Considerations
VII. Proposed Action and Request for Public Comment
VIII. Incorporation by Reference
IX. Statutory and Executive Order Reviews

I. Background for Proposed Action

A. Standards, Designations, Classifications, and Plans

    Under section 109 of the Clean Air Act (CAA or ``Act''), the EPA 
has established national ambient air quality standards (NAAQS or 
``standards'') for certain pervasive air pollutants (referred to as 
``criteria pollutants'') and conducts periodic reviews of the NAAQS to 
determine whether they should be revised or whether new NAAQS should be 
established. To date, the EPA has established NAAQS for particulate 
matter, ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide and 
lead. Under CAA section 110, states have primary responsibility for 
meeting the NAAQS within the state, and must submit an implementation 
plan that specifies the manner in which the state will attain and 
maintain the NAAQS. These implementation plans are referred to as 
``state implementation plans'' or ``SIPs.''
    Periodically, states must make SIP submissions of different types 
to meet additional CAA requirements. For example, after the EPA 
promulgates a new or revised NAAQS, under CAA section 110(a)(1) and 
(2), states are required to adopt and submit to the EPA a state 
implementation plan that provides for implementation, maintenance, and 
enforcement of the NAAQS. Such plans are referred to as 
``infrastructure SIPs.'' Similarly, after the EPA promulgates 
designations for a new or revised NAAQS, states with designated 
nonattainment areas must make SIP submissions that meet additional 
requirements for such nonattainment areas, under CAA section 172(c) 
and, in the case of the PM2.5 NAAQS, CAA sections 188 and 
189. This type of SIP submission is referred to as an ``attainment 
plan.''
    Under CAA section 110(k), the EPA is charged with evaluation of 
each SIP submission submitted by states for compliance with applicable 
CAA requirements, and for approval or disapproval (in whole or in part) 
of the submission. The EPA evaluates SIP submissions and takes action 
to approve, disapprove, or conditionally approve them through notice-
and-comment rulemaking published in the Federal Register. Where 
appropriate, the EPA may act on specific parts of a SIP submission in 
separate rulemaking actions.
    In 1997, the EPA promulgated new NAAQS for fine particulate matter, 
using particles with an aerodynamic diameter less than or equal to a 
nominal 2.5 micrometers (``PM2.5'') as the indicator.\1\ The 
EPA established primary and secondary annual and 24-hour standards for 
PM2.5. The EPA set the 1997 annual PM2.5 NAAQS, 
both primary and secondary standards, at 15.0 micrograms per cubic 
meter ([mu]g/m\3\), based on a 3-year average of annual mean 
PM2.5 concentrations. The EPA set the 1997 24-hour 
PM2.5 NAAQS, both primary and secondary standards, at 65 
[mu]g/m\3\, based on the 3-year average of the 98th percentile of 24-
hour PM2.5 concentrations. Collectively, we refer herein to 
the 1997 24-hour and annual PM2.5 NAAQS as the ``1997 
PM2.5 NAAQS.'' In 2006, the EPA promulgated a new, more 
stringent 24-hour NAAQS for PM2.5 by lowering the primary 
and secondary standards level from 65 [mu]g/m\3\ to 35 [mu]g/m\3\ 
(referred to herein as the ``2006 24-hour PM2.5 NAAQS'').\2\ 
In 2012, the EPA promulgated a new, more stringent annual NAAQS for 
PM2.5 by lowering the primary standards level from 15.0 
[mu]g/m\3\ to 12.0 [mu]g/m\3\ (herein referred to as the ``2012 annual 
PM2.5

[[Page 87990]]

NAAQS'').\3\ Each iteration of the PM2.5 NAAQS remains in 
effect, and states with designated nonattainment areas for each of them 
are obligated to meet applicable attainment plan requirements for them.
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    \1\ 62 FR 38652 (July 18, 1997) and 40 CFR 50.7.
    \2\ 71 FR 61144 (October 17, 2006) and 40 CFR 50.13.
    \3\ 78 FR 3086 (January 15, 2013) and 40 CFR 50.18.
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    The EPA established each of these NAAQS after considering 
substantial evidence from numerous health studies demonstrating that 
serious health effects are associated with exposures to 
PM2.5 concentrations above these levels. Epidemiological 
studies have shown statistically significant correlations between 
elevated PM2.5 levels and premature mortality. Other 
important health effects associated with PM2.5 exposure 
include aggravation of respiratory and cardiovascular disease (as 
indicated by increased hospital admissions, emergency room visits, 
absences from school or work, and restricted activity days), changes in 
lung function, and increased respiratory symptoms. Individuals 
particularly sensitive to PM2.5 exposure include older 
adults, people with heart and lung disease, and children.\4\ 
PM2.5 can be particles emitted by sources directly into the 
atmosphere as a solid or liquid particle (``primary PM2.5'' 
or ``direct PM2.5''), or can be particles that form in the 
atmosphere as a result of various chemical reactions involving 
PM2.5 precursor emissions emitted by sources (``secondary 
PM2.5''). The EPA has identified the precursors of 
PM2.5 to be oxides of nitrogen (``NOX''), sulfur 
oxides (``SOX''), volatile organic compounds (VOCs), and 
ammonia.\5\
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    \4\ 78 FR 3086, 3088.
    \5\ EPA, Air Quality Criteria for Particulate Matter, No. EPA/
600/P-99/002aF and EPA/600/P-99/002bF, October 2004.
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    Following promulgation of a new or revised NAAQS, the EPA is 
required under CAA section 107(d) to designate areas throughout the 
Nation as attaining or not attaining the NAAQS. As noted previously, 
for areas the EPA has designated nonattainment, states are required 
under the CAA to submit attainment plan SIP submissions. These SIP 
submissions must provide for, among other elements, reasonable further 
progress (RFP) towards attainment of the NAAQS, attainment of the NAAQS 
no later than the applicable attainment date, and implementation of 
contingency measures to take effect if the state fails to meet RFP or 
to attain the NAAQS by the applicable attainment date.
    The San Joaquin Valley is located in the southern half of 
California's Central Valley and includes all of San Joaquin, 
Stanislaus, Merced, Madera, Fresno, Tulare, and Kings Counties, and the 
valley portion of Kern County.\6\ The area is home to four million 
people and is the Nation's leading agricultural region. Stretching over 
250 miles from north to south and averaging 80 miles wide, it is 
partially enclosed by the Coast Mountain range to the west, the 
Tehachapi Mountains to the south, and the Sierra Nevada range to the 
east. In 2005, the EPA designated the San Joaquin Valley as 
nonattainment for the 1997 annual PM2.5 NAAQS and 
nonattainment for the 1997 24-hour PM2.5 NAAQS.\7\
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    \6\ For a precise description of the geographic boundaries of 
the San Joaquin Valley nonattainment area, see 40 CFR 81.305.
    \7\ 70 FR 944 (January 5, 2005), codified at 40 CFR 81.305.
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    The local air district with primary responsibility for developing 
attainment plan SIP submissions for the PM2.5 NAAQS in this 
area is the San Joaquin Valley Unified Air Pollution Control District 
(SJVUAPCD or ``District''). Once the District adopts the regional plan, 
the District submits the plan to the California Air Resources Board 
(CARB) for adoption as part of the California SIP. CARB is the State 
agency responsible for adopting and revising the California SIP and for 
submitting the SIP and SIP revisions to the EPA. Generally speaking, 
under California law, CARB is responsible for regulation of mobile 
sources while the local air districts are responsible for regulation of 
stationary sources.
    Originally, the EPA designated areas for the 1997 annual and 24-
hour PM2.5 NAAQS under subpart 1 (of part D of title I of 
the CAA), i.e., without specifying the classifications of nonattainment 
required by subpart 4. Later, in response to a court decision,\8\ the 
EPA classified nonattainment areas for the 1997 annual and 24-hour 
PM2.5 NAAQS, consistent with the classifications set forth 
in subpart 4. With respect to San Joaquin Valley, in 2014, the EPA 
classified the San Joaquin Valley as a ``Moderate'' nonattainment 
area,\9\ and then in 2015, reclassified the area as a ``Serious'' 
nonattainment area for the 1997 annual and 24-hour PM2.5 
NAAQS.\10\
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    \8\ In Natural Resources Defense Council v. EPA, 706 F.3d 428 
(D.C. Cir. 2013), the U.S. Court of Appeals for D.C. Circuit 
concluded that the EPA erred in implementing the 1997 
PM2.5 NAAQS solely pursuant to the general implementation 
requirements of subpart 1, without also considering the requirements 
specific to PM10 nonattainment areas in subpart 4, part D 
of title I of the CAA.
    \9\ 79 FR 31566 (June 2, 2014).
    \10\ 80 FR 18528 (April 7, 2015).
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    In 2016, the EPA determined that the San Joaquin Valley had failed 
to attain the 1997 annual and 24-hour PM2.5 NAAQS by the 
applicable ``Serious'' area attainment date.\11\ As a result, the State 
of California was required, under CAA section 189(d), to submit a new 
SIP submission that, among other elements, provides for expeditious 
attainment of the 1997 annual and 24-hour PM2.5 NAAQS and 
for a minimum five percent annual reduction in the emissions of direct 
PM2.5 or a PM2.5 plan precursor pollutant in the 
San Joaquin Valley (herein, referred to as a ``Five Percent Plan''). 
The Five Percent Plan for the 1997 annual and 24-hour PM2.5 
NAAQS was due no later than December 31, 2016.\12\
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    \11\ 81 FR 84481 (November 23, 2016).
    \12\ Id. at 84482.
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    With respect to the 2006 24-hour PM2.5 NAAQS, the EPA 
initially designated San Joaquin Valley as nonattainment under subpart 
1 (i.e., without classification) \13\ but, in 2014, in response to the 
court decision referred to previously, the EPA classified the area as 
Moderate.\14\ In 2016, the EPA reclassified San Joaquin Valley as a 
Serious nonattainment area for the 2006 24-hour PM2.5 NAAQS 
based on the EPA's determination that the area could not practicably 
attain these NAAQS by the applicable attainment date of December 31, 
2015.\15\ The EPA established an August 21, 2017 deadline for 
California to adopt and submit a SIP submission addressing the Serious 
nonattainment area requirements for the 2006 24-hour PM2.5 
NAAQS.\16\
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    \13\ 74 FR 58688 (November 13, 2009).
    \14\ 79 FR 31566.
    \15\ 81 FR 2993 (January 20, 2016).
    \16\ Id. at 3000.
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    With respect to the 2012 annual PM2.5 NAAQS, the EPA 
designated San Joaquin Valley as a Moderate nonattainment area in 
2015.\17\ Under CAA section 189 and the EPA's PM2.5 SIP 
Requirements Rule,\18\ the deadline for the state to submit an 
attainment plan SIP submission addressing the Moderate nonattainment 
area requirements for the 2012 annual PM2.5 NAAQS is 18 
months from the effective date of the designation of the area.\19\ The 
effective date of the designation of the San Joaquin Valley as a 
Moderate nonattainment area for the 2012 annual PM2.5 NAAQS 
was April 15, 2015, and thus, the deadline for a SIP submission 
addressing the Moderate area requirements was October 15, 2016.
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    \17\ 80 FR 2206 (January 15, 2015).
    \18\ 81 FR 58010 (August 24, 2016); codified at 40 CFR part 51, 
subpart Z.
    \19\ 40 CFR 51.1003(a).

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[[Page 87991]]

B. Findings and Contingency Measure Disapprovals

    In the wake of these EPA actions, CARB and the District worked 
together to prepare a comprehensive SIP submission to address the 
nonattainment area requirements for the 1997, 2006, and 2012 
PM2.5 NAAQS for San Joaquin Valley, but did not meet the 
various SIP submission deadlines. In late 2018, the EPA issued a 
finding of failure to submit to the State for the required attainment 
plan SIP submissions for the 1997 annual and 24-hour PM2.5 
NAAQS, the 2006 24-hour PM2.5 NAAQS, and the 2012 annual 
PM2.5 NAAQS for the San Joaquin Valley.\20\ The EPA's 
finding of failure to submit was effective January 7, 2019. Under CAA 
section 110(c), the EPA is obligated to promulgate a Federal 
Implementation Plan (FIP) within two years of a finding that a state 
has failed to make a required SIP submission, unless the state submits 
a SIP submission that corrects the deficiency, and the EPA approves 
that SIP submission, before the EPA promulgates such FIP.\21\ In this 
case, the finding of failure to submit established a deadline of 
January 7, 2021, for the EPA to promulgate a FIP to address all 
applicable attainment plan requirements for the 1997 annual and 24-hour 
PM2.5 NAAQS, the 2006 24-hour PM2.5 NAAQS, and 
2012 annual PM2.5 NAAQS for San Joaquin Valley, for which 
the EPA had not received and approved an adequate SIP submission from 
the State.
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    \20\ 83 FR 62720 (December 6, 2018).
    \21\ The finding of failure to submit also started an 18-month 
new source review (NSR) offset sanction clock and a 24-month highway 
sanction clock for the State of California. CAA section 179(a) and 
40 CFR 52.31.
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    To address a portion of current FIP obligation, the EPA recently 
proposed a FIP to address the contingency measures requirements for the 
San Joaquin Valley for the 1997 annual, 2006 24-hour, and 2012 annual 
PM2.5 NAAQS.\22\ In short, the proposed contingency measure 
FIP includes two specific contingency measures, one of which would 
extend certain wood-burning curtailment restrictions Valley-wide and 
another which would extend certain fugitive dust requirements to 
certain open areas that are not currently subject to control 
requirements.
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    \22\ 88 FR 53431 (August 8, 2023).
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    On May 10, 2019, CARB submitted two SIP submissions to address the 
nonattainment area requirements for all four of the relevant 
PM2.5 NAAQS for the San Joaquin Valley, including the 
contingency measure requirement.\23\ On November 8, 2021, CARB 
submitted a third SIP submission to amend the portions of the May 10, 
2019 SIP submissions that pertain to the 1997 annual PM2.5 
NAAQS.\24\ As discussed in the following paragraph, the EPA has 
previously taken a series of actions on these SIP submissions to 
address different nonattainment area requirements for each of the 
NAAQS. In this proposed action, we are focused only on the contingency 
measure requirements.
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    \23\ The SIP revisions submitted on May 10, 2019, include the 
``2016 Moderate Area Plan for the 2012 PM2.5 Standard'' 
(``2016 PM2.5 Plan'') and the ``2018 Plan for the 1997, 
2006, and 2012 PM2.5 Standards'' (``2018 PM2.5 
Plan''), which incorporates by reference the ``San Joaquin Valley 
Supplement to the 2016 State Strategy for the State Implementation 
Plan'' (``Valley State SIP Strategy''). On February 11, 2020, CARB 
submitted a revised version of Appendix H (``RFP, Quantitative 
Milestones, and Contingency'') that replaces the version submitted 
with the 2018 PM2.5 Plan on May 10, 2019. The EPA found 
the SIP submissions complete in a letter dated June 24, 2020, from 
Elizabeth J. Adams, Director, EPA Region IX, to Richard W. Corey, 
Executive Officer, CARB. The EPA's completeness determination 
terminated the NSR offsets and highway sanctions started by the 
December 6, 2018 finding of failure to submit but did not affect the 
FIP obligation.
    \24\ The SIP revision submitted on November 8, 2021, is titled 
``Attainment Plan Revision for the 1997 Annual PM2.5 
Standard'' (``15 [mu]g/m\3\ SIP Revision'').
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    In 2020, the EPA approved the portion of the SIP submissions 
related to the 2006 24-hour PM2.5 NAAQS, but deferred action 
on the contingency measure element.\25\ In 2021, the EPA approved the 
portion of the SIP submissions related to the Moderate area 
requirements for the 2012 annual PM2.5 NAAQS except for the 
contingency measure element, which the EPA disapproved.\26\ The EPA 
also disapproved the previously-deferred contingency measure element 
for the 2006 24-hour PM2.5 NAAQS.\27\ In another 2021 
action, the EPA disapproved the portion of the SIP submissions related 
to the 1997 annual PM2.5 NAAQS except for the emissions 
inventory, which the Agency approved.\28\ In 2022, the EPA approved the 
portion of the SIP submission related to the 1997 24-hour 
PM2.5 NAAQS, with the exception of the contingency measure 
element.\29\ In our action on the SIP submission related to the 1997 
24-hour PM2.5 NAAQS, we disapproved the contingency measure 
element, but also found that the contingency measure requirement was 
moot for that particular PM2.5 NAAQS because of the EPA's 
concurrent determination of attainment by the applicable attainment 
date for San Joaquin Valley for the 1997 24-hour PM2.5 
NAAQS.\30\
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    \25\ 85 FR 44192 (July 22, 2020).
    \26\ 86 FR 67343 (November 26, 2021).
    \27\ Id.
    \28\ 86 FR 67329 (November 26, 2021).
    \29\ 87 FR 4503 (January 28, 2022).
    \30\ Id.
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    In July 2023, the EPA proposed approval of the portions of the 
three SIP submissions that pertain to the 1997 annual PM2.5 
NAAQS in the San Joaquin Valley nonattainment area.\31\ More recently, 
we took action to finalize our approval of the SIP submissions for the 
1997 annual PM2.5 NAAQS, as proposed; however, our recent 
action on various elements of the San Joaquin Valley PM2.5 
plan for the 1997 annual PM2.5 NAAQS did not address the 
contingency measures requirements for that particular PM2.5 
NAAQS.\32\
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    \31\ 88 FR 45276 (July 14, 2023).
    \32\ EPA, ``Air Quality State Implementation Plans; Approvals 
and Promulgations: California; 1997 Annual Fine Particulate Matter 
Serious and Clean Air Act Section 189(d) Nonattainment Area 
Requirements; San Joaquin Valley, CA,'' Final rule, signed December 
5, 2023.
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    With respect to contingency measure elements, the State's May 10, 
2019 PM2.5 SIP submissions for San Joaquin Valley relied 
upon contingency provisions included in District Rule 4901 (``Wood 
Burning Fireplaces and Wood Burning Heaters''), specifically section 
5.7.3 of the rule, and a demonstration that the emissions reductions 
from the contingency measure would be sufficient to meet the 
contingency measure SIP requirements of CAA section 172(c)(9) if the 
reductions were viewed together with ``surplus'' \33\ emissions 
reductions from already-implemented measures.\34\ We disapproved the 
contingency measure elements for San Joaquin Valley for the 1997 
annual, 2006 24-hour, and 2012 annual PM2.5 NAAQS because 
the contingency provision (i.e., section 5.7.3) in Rule 4901 did not 
address the potential for State failures to meet RFP, to meet a 
quantitative milestone, or to submit a quantitative milestone report. 
In addition, the contingency measure provision of Rule 4901 was not 
structured to achieve any additional emissions reductions if the EPA 
were to find that the monitoring locations in the ``hot spot'' counties 
(i.e., Fresno, Kern, or Madera) are the only counties in the San 
Joaquin Valley that are violating the PM2.5 NAAQS as of the 
attainment date.\35\ In addition, the contingency

[[Page 87992]]

measure elements did not provide sufficient justification as to why the 
one adopted contingency measure (in Rule 4901) would suffice to meet 
the CAA requirements for contingency measures for the PM2.5 
NAAQS for San Joaquin Valley notwithstanding the fact that the one 
measure would not achieve one year's worth of RFP, as recommended in 
longstanding EPA guidance.36 37
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    \33\ In this context, ``surplus'' refers to emissions reductions 
not otherwise relied upon for RFP or attainment demonstrations.
    \34\ See 86 FR 38652, 38668-38669 (July 22, 2021); 86 FR 49100, 
49123-49124 and 49132-49133 (September 1, 2021).
    \35\ See 86 FR 38652, 38669-38670 (proposed disapproval of the 
contingency measure element for the 1997 annual PM2.5 
NAAQS); and 86 FR 49100, 49124-49125 (proposed disapproval of the 
contingency measure element for the 2012 annual PM2.5 
NAAQS) and 49133-49134 (proposed disapproval of the contingency 
measure element for the 2006 24-hour PM2.5 NAAQS) 
(September 1, 2021). The proposed disapprovals were finalized at 86 
FR 67329 (1997 annual PM2.5 NAAQS); 86 FR 67343 (2012 
annual PM2.5 NAAQS and 2006 24-hour PM2.5 
NAAQS).
    \36\ Id.
    \37\ 81 FR 58010, 58066. See also 57 FR 13498, 13511, 13543-
13544 (April 16, 1992), and 59 FR 41998, 42014-42015 (August 16, 
1994).
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    In our final rules disapproving the contingency measure elements 
for San Joaquin Valley for the 1997 annual, 2006 24-hour, and 2012 
annual PM2.5 NAAQS, we indicated that the disapprovals would 
begin an 18-month clock for imposition of the offset sanction in CAA 
section 179(b)(2) and a 24-month clock for imposition of the highway 
funding sanction in CAA section 179(b)(1) unless the State submits, and 
the EPA approves, a SIP revision that corrects the deficiencies that we 
identified in our final actions prior to implementation of the 
sanctions.\38\
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    \38\ 86 FR 67329, 67341 (1997 annual PM2.5 NAAQS); 86 
FR 67343, 67346-67347 (2012 annual PM2.5 NAAQS and 2006 
24-hour PM2.5 NAAQS).
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II. Summary of SIP Submissions and Evaluation for Compliance With SIP 
Revision Procedural Requirements

A. Summary of SIP Submissions

    On June 8, 2023, CARB submitted the ``PM2.5 Contingency 
Measure State Implementation Plan Revision (May 18, 2023)'' (herein 
referred to as the ``SJV PM2.5 Contingency Measure SIP'') to 
the EPA as a revision to the California SIP.\39\ Also on June 8, 2023, 
CARB submitted revisions to Rule 4901 that add PM2.5 NAAQS 
contingency provisions that we refer to herein as the ``Residential 
Wood Burning Contingency Measure.'' The District adopted the SJV 
PM2.5 Contingency Measure SIP and Residential Wood Burning 
Contingency Measure on May 18, 2023, and submitted them to CARB for 
adoption and submission to the EPA as SIP revisions. The District 
adopted the SJV PM2.5 Contingency Measure SIP and 
Residential Wood Burning Contingency Measure to correct the 
deficiencies identified by the EPA in the November 26, 2021 
disapprovals of the contingency measure elements for the 1997 annual, 
2006 24-hour, and 2012 annual PM2.5 NAAQS and the previously 
adopted contingency provisions of Rule 4901. In this document, we are 
proposing action on both the SJV PM2.5 Contingency Measure 
SIP and the Residential Wood Burning Contingency Measure.
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    \39\ CARB adopted the SJV PM2.5 Contingency Measure 
SIP and Residential Wood Burning Contingency Measure as SIP 
revisions on June 7, 2023, through Executive Order S-23-010 and 
submitted the SIP revisions to the EPA electronically on June 8, 
2023, as attachments to a letter dated June 7, 2023, from Steven S. 
Cliff, Ph.D., Executive Officer, CARB to Martha Guzman, Regional 
Administrator, EPA Region IX.
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    The June 8, 2023 SIP submission includes the two specific SIP 
revisions (i.e., the SJV PM2.5 Contingency Measure SIP and 
the Residential Wood Burning Contingency Measure), as well as 
supporting material including the resolutions of adoption, CARB 
evaluation and completeness forms, and evidence of public notice and 
hearing. The SJV PM2.5 Contingency Measure SIP includes a 
general discussion of contingency measures and related requirements and 
guidance, context for this particular SIP revision, and feasibility 
analyses developed by the District and CARB to identify potential 
contingency measures for the PM2.5 NAAQS for the San Joaquin 
Valley. (In our evaluation of the latter, we refer to the State's 
feasibility analyses herein as infeasibility demonstrations.) The SJV 
PM2.5 Contingency Measure SIP includes appendices that 
provide further detailed information and documentation for, among other 
things, the emissions reductions estimated for the Residential Wood 
Burning Contingency Measure. The District also attached excerpts from 
certain previously submitted SIPs to provide support for the 
conclusions drawn by the District and CARB with respect to the 
infeasibility of adopting additional contingency measures for the San 
Joaquin Valley. The June 8, 2023 SIP submission of the SJV 
PM2.5 Contingency Measure SIP and Residential Wood Burning 
Contingency Measure was deemed administratively complete by operation 
of law on December 8, 2023, consistent with CAA section 110(k)(1).\40\
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    \40\ In addition, see EPA Region IX SIP Completeness Checklist, 
October 13, 2023.
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    Through adoption of the SJV PM2.5 Contingency Measure 
SIP, the District committed to evaluating revisions to a specific 
fugitive dust rule, District Rule 8051 (``Open Areas''), for potential 
as a second contingency measure for the PM2.5 NAAQS for the 
SJV.\41\ On September 21, 2023, the District adopted revisions to Rule 
8051 to add contingency provisions that we refer to herein as the 
``Rural Open Areas Contingency Measure.'' The District adopted the 
Rural Open Areas Contingency Measure to supplement the SJV 
PM2.5 Contingency Measure SIP by providing additional 
emissions reductions for the San Joaquin Valley if triggered by one of 
the contingency events. On October 16, 2023, CARB submitted the Rural 
Open Areas Contingency Measure to the EPA as a revision to the 
California SIP.\42\ In this document, we are also proposing action on 
the Rural Open Areas Contingency Measure.
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    \41\ SJV PM2.5 Contingency Measure SIP, pp. 31-32.
    \42\ CARB adopted the Rural Open Areas Contingency Measure as a 
SIP revision on October 13, 2023, through Executive Order S-23-014 
and submitted the SIP revision to the EPA electronically on October 
16, 2023, as an attachment to a letter dated October 13, 2023, from 
Steven S. Cliff, Ph.D., Executive Officer, CARB to Martha Guzman, 
Regional Administrator, EPA Region IX.
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    The October 16, 2023 SIP submission includes the SIP revision 
itself (i.e., the Rural Open Areas Contingency Measure) as well as 
supporting material including the resolutions of adoption, CARB 
evaluation and completeness forms, and evidence of public notice and 
hearing. The EPA has reviewed the October 16, 2023 SIP submission of 
the Rural Open Areas Contingency Measure and finds it to be 
administratively complete for the purposes of CAA section 110(k)(1), 
effective upon publication of this proposed rule.\43\
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    \43\ EPA Region IX SIP Completeness Checklist, October 18, 2023.
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B. Evaluation for Compliance With SIP Revision Procedural Requirements

    Under CAA section 110(l), SIP revisions must be adopted by the 
state, and the state must provide for reasonable public notice and 
hearing prior to adoption. Pursuant to 40 CFR 51.102, states must 
provide at least 30-days' notice of any public hearing to be held on a 
proposed SIP revision. States must provide the opportunity to submit 
written comments and allow the public the opportunity to request a 
public hearing within that period.\44\
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    \44\ In addition to establishing procedural requirements for SIP 
revisions, CAA section 110(l) prohibits the EPA from approving any 
SIP revision that would interfere with any applicable requirement 
for reasonable further progress (RFP) or attainment or any other 
applicable requirement of the CAA. In this instance, the Residential 
Wood Burning Contingency Measure and the Rural Open Areas 
Contingency Measure would provide emissions reductions beyond those 
needed for RFP and attainment of the NAAQS in San Joaquin Valley 
and, thus, would not interfere with the RFP and attainment 
demonstrations for the area.

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[[Page 87993]]

    The District adopted the SJV PM2.5 Contingency Measure 
SIP and the Residential Wood Burning Contingency Measure on May 18, 
2023, through Resolution No. 2023-5-7, following a public hearing held 
on the same day. Prior to adoption, the District published notice of 
the May 18, 2023 public hearing in newspapers of general circulation in 
each of the eight counties that comprise the San Joaquin Valley, and 
provided more than 30 days for submission of written comments. CARB 
subsequently adopted the SJV PM2.5 Contingency Measure SIP 
and the Residential Wood Burning Contingency Measure as a revision to 
the SIP on June 7, 2023, through Executive Order S-23-010. CARB then 
submitted the SJV PM2.5 Contingency Measure SIP and the 
Residential Wood Burning Contingency Measure to the EPA on June 8, 
2023, as an attachment to a transmittal letter dated June 7, 2023.
    The District adopted the Rural Open Areas Contingency Measure on 
September 21, 2023, through Resolution No. 2023-9-9, following a public 
hearing held on the same day. Prior to adoption, the District published 
notice of the September 21, 2023 public hearing in newspapers of 
general circulation in each of the eight counties that comprise the San 
Joaquin Valley, and provided more than 30 days for submission of 
written comments. CARB subsequently adopted the Rural Open Areas 
Contingency Measure as a revision to the SIP on October 13, 2023, 
through Executive Order S-23-014. CARB then submitted the Rural Open 
Areas Contingency Measure to the EPA on October 16, 2023, as an 
attachment to a transmittal letter dated October 13, 2023.
    Based on the materials provided in the June 8, 2023 and October 16, 
2023 SIP submissions, we propose to find that the District and the CARB 
have met the procedural requirements for adoption and submission of SIP 
revisions under CAA section 110(l) and 40 CFR 51.102.

III. Contingency Measure Requirements, Guidance, and Legal Precedent

    The EPA first provided its views on the CAA's requirements for 
particulate matter plans under part D, title I of the Act in the 
following guidance documents: (1) ``State Implementation Plans; General 
Preamble for the Implementation of Title I of the Clean Air Act 
Amendments of 1990'' (``General Preamble''); \45\ (2) ``State 
Implementation Plans; General Preamble for the Implementation of Title 
I of the Clean Air Act Amendments of 1990; Supplemental''; \46\ and (3) 
``State Implementation Plans for Serious PM-10 Nonattainment Areas, and 
Attainment Date Waivers for PM-10 Nonattainment Areas Generally; 
Addendum to the General Preamble for the Implementation of Title I of 
the Clean Air Act Amendments of 1990'' (``General Preamble 
Addendum'').\47\ More recently, in the PM2.5 SIP 
Requirements Rule, the EPA established regulatory requirements and 
provided further interpretive guidance on the statutory SIP 
requirements that apply to areas designated nonattainment for all 
PM2.5 NAAQS.\48\
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    \45\ 57 FR 13498 (April 16, 1992).
    \46\ 57 FR 18070 (April 28, 1992).
    \47\ 59 FR 41998 (August 16, 1994).
    \48\ 81 FR 58010.
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A. Statutory and Regulatory Requirements

    Under CAA section 172(c)(9), states required to make an attainment 
plan SIP submission must include contingency measures to be implemented 
if the area fails to meet RFP (``RFP contingency measures'') or fails 
to attain the NAAQS by the applicable attainment date (``attainment 
contingency measures''). Under the PM2.5 SIP Requirements 
Rule, states must include contingency measures that provide that the 
state will implement them following a determination by the EPA that the 
state has failed: (1) to meet any RFP requirement in the approved SIP; 
(2) to meet any quantitative milestone (QM) in the approved SIP; (3) to 
submit a required QM report; or (4) to attain the applicable 
PM2.5 NAAQS by the applicable attainment date.\49\ 
Contingency measures must be fully adopted rules or control measures 
that are ready to be implemented quickly upon failure to meet RFP or 
failure of the area to meet the relevant NAAQS by the applicable 
attainment date.\50\ In general, we expect all actions needed to effect 
full implementation of the measures to occur within 60 days after the 
EPA notifies the state of a failure to meet RFP or to attain.\51\ 
Moreover, we expect the additional emissions reductions from the 
contingency measures to be achieved within a year of the triggering 
event.\52\
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    \49\ 40 CFR 51.1014(a).
    \50\ 81 FR 58010, 58066 and General Preamble Addendum, 42015.
    \51\ 81 FR 58010, 58066. See also General Preamble 13512, 13543-
13544, and General Preamble Addendum, 42014-42015.
    \52\ General Preamble, 13511.
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    The purpose of contingency measures is to continue progress in 
reducing emissions while a state revises its SIP to meet the missed RFP 
requirement or to correct ongoing nonattainment. Neither the CAA nor 
the EPA's implementing regulations establish a specific level of 
emission reductions that implementation of contingency measures must 
achieve, but the EPA recommends that contingency measures should 
provide for emission reductions equivalent to approximately one year of 
reductions needed for RFP in the nonattainment area.\53\ For 
PM2.5 NAAQS SIP planning purposes, the EPA recommends that 
RFP should be calculated as the overall level of reductions needed to 
demonstrate attainment divided by the number of years from the base 
year to the attainment year.\54\ As part of the attainment plan SIP 
submission, the EPA expects states to explain the amount of anticipated 
emissions reductions that the contingency measures will achieve. In the 
event that a state is unable to identify and adopt contingency measures 
that will provide for approximately one year's worth of emissions 
reductions, then EPA recommends that the state provide a reasoned 
justification why the smaller amount of emissions reductions is 
appropriate.\55\
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    \53\ 81 FR 58010, 58066. See also General Preamble, 13511, 
13543-13544, and General Preamble Addendum, 42014-42015.
    \54\ 81 FR 58010, 58066.
    \55\ 81 FR 58010, 58067.
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    To satisfy the contingency measure requirements of 40 CFR 51.1014, 
the contingency measures adopted as part of a PM2.5 NAAQS 
attainment plan must consist of control measures for the area that are 
not otherwise required to meet other attainment plan requirements 
(e.g., to meet reasonably available control measure (RACM)/reasonably 
available control technology (RACT) requirements). By definition, 
contingency measures are measures that are over and above what a state 
must adopt and impose to meet RFP and to provide for attainment by the 
applicable attainment date.
    Contingency measures serve the purpose of providing additional 
emission reductions during the period after a failure to meet RFP or 
failure to attain as the state prepares a new SIP submission to rectify 
the problem. Accordingly, contingency measures must provide such 
additional emission reductions during an appropriate period and must 
specify the timeframe within which their requirements would become 
effective following any of the EPA determinations specified in 40 CFR 
51.1014(a).

[[Page 87994]]

    In addition, to comply with CAA section 172(c)(9), contingency 
measures must be both conditional and prospective, so that they will go 
into effect and achieve emission reductions only in the event of a 
future triggering event such as a failure to meet RFP or a failure to 
attain. In a 2016 decision called Bahr v. EPA,\56\ the Ninth Circuit 
Court of Appeals held that CAA section 172(c)(9) does not allow EPA 
approval of already-implemented control measures as contingency 
measures. Thus, already-implemented measures cannot serve as 
contingency measures under CAA section 172(c)(9). For purposes of the 
PM2.5 NAAQS, a state must develop, adopt, and submit one or 
more contingency measures to be triggered upon a failure to meet any 
RFP requirement, failure to meet a quantitative milestone requirement, 
or failure to attain the NAAQS by the applicable attainment date, 
regardless of the extent to which already-implemented measures would 
achieve surplus emission reductions beyond those necessary to meet RFP 
or quantitative milestone requirements and beyond those predicted to 
achieve attainment of the NAAQS.
---------------------------------------------------------------------------

    \56\ Bahr v. EPA, 836 F.3d 1218, 1235-1237 (9th Cir. 2016). See 
also Sierra Club v. EPA, 21 F.4th 815, 827-28 (D.C. Cir. 2021).
---------------------------------------------------------------------------

    In a recent decision on the EPA's approval of a SIP contingency 
measure element for the ozone NAAQS, the Ninth Circuit Court of Appeals 
held that, under the EPA's current guidance, the surplus emissions 
reductions from already-implemented measures cannot be relied upon to 
justify the approval of a contingency measure that would achieve far 
less than one year's worth of RFP as sufficient by itself to meet the 
contingency measure requirements of CAA sections 172(c)(9) and 
182(c)(9) for the nonattainment area.\57\
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    \57\ Assoc. of Irritated Residents v. EPA, 10 F.4th 937, 946-47 
(9th Cir. 2021) (``AIR v. EPA'' or ``AIR'').
---------------------------------------------------------------------------

B. Draft Revised Contingency Measure Guidance

    In March 2023, the EPA published notice of availability announcing 
a new draft guidance addressing the contingency measures requirement of 
section 172(c)(9), entitled ``Draft: Guidance on the Preparation of 
State Implementation Plan Provisions that Address the Nonattainment 
Area Contingency Measure Requirements for Ozone and Particulate Matter 
(DRAFT--3/17/23--Public Review Version)'' (herein referred to as the 
``Draft Revised Contingency Measure Guidance'') and opportunity for 
public comment.\58\ The principal differences between the draft revised 
guidance and existing guidance on contingency measures relate to the 
EPA's recommendations concerning the specific amount of emission 
reductions that implementation of contingency measures should achieve, 
and the timing for when the emissions reductions from the contingency 
measures should occur. The Draft Revised Contingency Measure Guidance 
also provides recommended procedures for developing a demonstration, if 
applicable, that the area lacks sufficient feasible measures to achieve 
one year's worth of reductions, building on existing guidance that the 
state provide a reasoned justification why the smaller amount of 
emissions reductions is appropriate.
---------------------------------------------------------------------------

    \58\ 88 FR 17571 (March 23, 2023). The Draft Revised Contingency 
Measure Guidance is available at https://www.epa.gov/air-quality-implementation-plans/draft-contingency-measures-guidance.
---------------------------------------------------------------------------

    Under the Draft Revised Contingency Measure Guidance, the 
recommended level of emissions reductions that contingency measures 
should achieve would represent one year's worth of ``progress'' as 
opposed to one year's worth of RFP.\59\ One year's worth of 
``progress'' is calculated by determining the average annual reductions 
between the base year emissions inventory and the projected attainment 
year emissions inventory, determining what percentage of the base year 
emissions inventory this amount represents, then applying that 
percentage to the projected attainment year emissions inventory to 
determine the amount of reductions needed to ensure ongoing progress if 
contingency measures are triggered.
---------------------------------------------------------------------------

    \59\ Draft Revised Contingency Measure Guidance, p. 22.
---------------------------------------------------------------------------

    With respect to the time period within which reductions from 
contingency measures should occur, the EPA previously recommended that 
contingency measures take effect within 60 days of being triggered, and 
that the resulting emission reductions generally occur within one year 
of the triggering event. Under the Draft Revised Contingency Measure 
Guidance, in instances where there are insufficient contingency 
measures available to achieve the recommended amount of emissions 
reductions within one year of the triggering event, the EPA believes 
that contingency measures that provide reductions within up to two 
years of the triggering event would be appropriate to consider towards 
achieving the recommended amount of emissions reductions. The Draft 
Revised Contingency Measure Guidance does not alter the 60-day 
recommendation for the contingency measures to take initial effect.
    If, after adequately evaluating additional control measures, the 
state is unable to identify contingency measures that would provide 
approximately one year's worth of emissions reductions, the Draft 
Revised Contingency Measure Guidance recommends that the state should 
provide a reasoned justification (referred to herein as an 
``infeasibility demonstration'') that explains and documents how it has 
evaluated all existing and potential control measures relevant to the 
appropriate source categories and pollutants in the nonattainment area 
and has reached reasonable conclusions regarding whether such measures 
are feasible.\60\
---------------------------------------------------------------------------

    \60\ Draft Revised Contingency Measure Guidance, p. 29.
---------------------------------------------------------------------------

    As explained in the Draft Revised Contingency Measure Guidance, 
while the EPA notes that CAA section 172(c)(9) and section 182(c)(9) do 
not explicitly provide for consideration of whether specific measures 
are feasible, the Agency believes that it is reasonable to infer that 
the statute does not require control measures regardless of any 
technological or cost constraints whatsoever.\61\ It is more reasonable 
to interpret the contingency measure requirement not to require air 
agencies to adopt and impose infeasible measures. The statutory 
provisions applicable to other nonattainment area plan control measure 
requirements, including RACM/RACT (for ozone and PM), best available 
control measure (BACM)/best available control technology (BACT) (for 
PM), and most stringent measures (MSM) (for PM), allow air agencies to 
exclude certain control measures that are deemed unreasonable or 
infeasible (depending on the requirement). For example, the MSM 
provision in CAA section 188(e) requires plans to include ``the most 
stringent measures that are included in the implementation plan of any 
state or are achieved in practice in any state, and can feasibly be 
implemented in the area.'' The EPA considers it reasonable to conclude 
that Congress similarly did not expect air agencies to satisfy the 
contingency measure requirement with infeasible measures. Thus, the EPA 
anticipates that a demonstrated lack of feasible measures would be a 
reasoned justification for adopting contingency measures that only 
achieve a lesser amount of emission reductions.
---------------------------------------------------------------------------

    \61\ Id.

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[[Page 87995]]

IV. EPA Review of San Joaquin Valley Contingency Measures

    We provide our review of two specific contingency measures--the 
Residential Wood Burning Contingency Measure and the Rural Open Areas 
Contingency Measure--in sections IV.A and IV.B of this document, 
respectively. As noted previously, we are reviewing and proposing 
approval of a third contingency measure, the Smog Check Contingency 
Measure,\62\ in a separate rulemaking; \63\ however, we provide a 
summary of the Smog Check Contingency Measure in section IV.C for 
informational purposes. Because we are proposing approval of the 
contingency measures, we take into account the measures' anticipated 
emission reductions in our evaluation of the SJV PM2.5 
Contingency Measure SIP, which we present in section V of this proposed 
rule.
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    \62\ CARB, ``California Smog Check Contingency Measure State 
Implementation Plan Revision,'' release date September 15, 2023, 
(``Smog Check Contingency Measure'').
    \63\ EPA, ``Air Plan Revision; California; Motor Vehicle 
Inspection and Maintenance Program Contingency Measure,'' Proposed 
rule, published in this Federal Register.
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A. Residential Wood Burning Contingency Measure

1. Background and Regulatory History
    Residential wood burning includes wood-burning heaters (i.e., 
woodstoves, pellet stoves, and wood-burning fireplace inserts), which 
are used primarily for heat generation, and wood-burning fireplaces, 
which are used primarily for aesthetic purposes. All of these devices 
emit direct PM2.5 and NOX. However, wood-burning 
heaters, that are certified under the EPA's New Source Performance 
Standards (NSPS) emit lower levels of PM2.5 compared to 
wood-burning fireplaces and non-certified heaters when properly 
installed, operated, and maintained.
    Residential wood-burning is included within the ``Residential Fuel 
Combustion'' emissions inventory category within the 2018 
PM2.5 Plan's emissions inventories. In the 2018 
PM2.5 Plan, the District estimates emissions of 2.82 tons 
per day (tpd) of PM2.5 and 0.42 tpd NOX (annual 
average) specifically from residential wood burning for each year from 
2017 onward. However, these estimates do not account for the effect of 
2019 amendments to Rule 4901, discussed in the following section of 
this document.
    Rule 4901 (``Wood Burning Fireplaces and Wood Burning Heaters'') 
establishes requirements for the sale/transfer, operation, and 
installation of wood-burning devices and on the advertising of wood for 
sale intended for burning in a wood-burning fireplace, wood-burning 
heater, or outdoor wood-burning device within the San Joaquin Valley. 
One of the most effective ways to reduce wintertime smoke is a 
curtailment program that restricts use of wood-burning heaters and 
fireplaces on days that are conducive to buildup of PM concentrations 
(i.e., days where ambient PM2.5 and/or PM10 
concentrations are forecast to be above a particular level, known as a 
``curtailment threshold'').
    Rule 4901 includes a tiered mandatory curtailment program that 
establishes different curtailment thresholds based on the type of 
devices (i.e., registered clean-burning devices \64\ vs. unregistered 
devices) and different counties (i.e., hot spot vs. non-hot spot). 
During a Level One Episodic Wood Burning Curtailment, operation of 
wood-burning fireplaces and other unregistered wood-burning heaters or 
devices is prohibited, but properly operated, registered wood-burning 
heaters may be used.\65\ During a Level Two Episodic Wood Burning 
Curtailment, operation of any wood-burning device is prohibited.\66\ 
However, the rule includes an exemption from the curtailment provisions 
for (1) locations where piped natural gas service is not available and 
(2) residences for which a wood-burning fireplace or wood-burning 
heater is the sole available source of heat.\67\
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    \64\ In order to be registered, a device must either be 
certified under the NSPS at time of purchase or installation and at 
least as stringent as Phase II requirements or be a pellet-fueled 
wood burning heater exempt from EPA certification requirements at 
the time of purchase or installation (Rule 4901, section 5.9.1). The 
rule includes requirements for documentation and inspection to 
verify compliance with these standards (Rule 4901, sections 5.9.2 
and 5.10).
    \65\ Rule 4901, section 5.7.1.
    \66\ Rule 4901, section 5.7.2.
    \67\ Rule 4901, section 5.7.4.
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    In order to implement the curtailment program under Rule 4901, the 
District develops daily air quality forecasts, based on EPA and CARB 
guidance, which include a projection of the maximum PM2.5 
concentration in each county for the following day.\68\ District staff 
then compare this maximum county PM2.5 concentration 
forecast with the curtailment thresholds in Rule 4901. If a county's 
PM2.5 forecast exceeds the applicable threshold, then the 
District's Air Pollution Control Officer declares a curtailment for the 
county for the following day.
---------------------------------------------------------------------------

    \68\ Email dated October 9, 2019, from Jon Klassen, SJVUAPCD to 
Meredith Kurpius, EPA Region IX, Subject: ``RE: Info to support Rule 
4901.''
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    In 2019, the District lowered the curtailment thresholds in Madera, 
Fresno, and Kern counties, which the District identified as ``hot 
spot'' counties, because they were ``either new areas of gas utility or 
areas deemed to have persistently poor air quality.'' \69\ Table 1 
presents the residential curtailment thresholds in Rule 4901, as 
revised in 2019.
---------------------------------------------------------------------------

    \69\ 2018 PM2.5 Plan, Appendix J, 60.

  Table 1--Residential Wood Burning Curtailment Thresholds in Rule 4901
                          [As amended in 2019]
------------------------------------------------------------------------
                                                         Non-hot spot
                                                         counties (San
      Episodic wood burning        Hot spot counties       Joaquin,
       curtailment levels          (Madera, Fresno,       Stanislaus,
                                       and Kern)      Merced, Kings, and
                                                            Tulare)
------------------------------------------------------------------------
Level One (No Burning Unless      12 [mu]g/m\3\.....  20 [mu]g/m\3\.
 Registered).
Level Two (No Burning for All)..  35 [mu]g/m\3\.....  65 [mu]g/m\3\.
------------------------------------------------------------------------

    The 2019 revision by the District also added a provision to the 
rule to operate as a contingency measure, which would lower the 
curtailment thresholds for any county that failed to attain the 
applicable standards to levels consistent with current thresholds for 
hot spot counties. However, the EPA disapproved this provision because 
it did not meet all of the CAA requirements for contingency 
measures.\70\ Specifically, it did not address three of the four 
required triggers for contingency measures in 40 CFR 51.1014(a) and was 
not structured to achieve any additional emissions reductions if the 
EPA found that the monitoring locations in the ``hot spot''

[[Page 87996]]

counties (i.e., Fresno, Kern, or Madera) were the only counties in the 
San Joaquin Valley that are violating the applicable PM2.5 
NAAQS as of the attainment date.\71\ In addition, with respect to the 
1997 annual PM2.5 NAAQS in particular, the EPA also 
disapproved the contingency provision in Rule 4901 because the EPA was 
concurrently disapproving the RFP and attainment demonstrations and, 
thus, was unable to determine whether the emissions reductions from the 
contingency provision were in fact surplus to the reductions that would 
be needed to provide for RFP and attainment for the 1997 annual 
PM2.5 NAAQS in the SJV.\72\ Accordingly, the SIP-approved 
version of Rule 4901 does not include any contingency provision.
---------------------------------------------------------------------------

    \70\ 86 FR 67329, 67338 (for the 1997 annual PM2.5 
NAAQS) and 86 FR 67343, 67345 (for the 2006 24-hour PM2.5 
NAAQS and 2012 annual PM2.5 NAAQS).
    \71\ Id. See also 86 FR 38652, 38669 (proposed rule on 
contingency measures element for the 1997 annual PM2.5 
NAAQS) and 86 FR 49100, 49125 and 49133-49134 (proposed rule on 
contingency measures element for the 2012 annual PM2.5 
NAAQS and 2006 24-hour PM2.5 NAAQS, respectively).
    \72\ 86 FR 67329, 67338.
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2. Summary of State Submission
    On May 18, 2023, the District amended the contingency measure in 
section 5.7.3 of Rule 4901, and CARB submitted the amended rule as part 
of the June 8, 2023 SIP Submission. The contingency measure would be 
triggered by a final determination by the EPA that the District failed 
to meet one or more of the following triggering events for the 
applicable PM2.5 NAAQS:
    (1) Any Reasonable Further Progress requirement;
    (2) Any quantitative milestone;
    (3) Submission of a quantitative milestone report; or
    (4) Attainment of the applicable PM2.5 NAAQS by the 
applicable attainment date.
    Following the first such triggering event, the measure would lower 
the thresholds for the non-hot spot counties to the current thresholds 
for hot spot counties (i.e., from 20 [mu]g/m\3\ to 12 [mu]g/m\3\ for 
unregistered devices; and from 65 [mu]g/m\3\ to 35 [mu]g/m\3\ for 
registered devices). Following the second such event, the measure would 
further lower the threshold for unregistered devices in all counties of 
the San Joaquin Valley from 12 [mu]g/m\3\ to 11 [mu]g/m\3\.
    The District estimates that the Residential Wood Burning 
Contingency Measure for the first triggering event would achieve annual 
average emissions reductions of 0.5793 tpd direct PM2.5 and 
0.0817 tpd NOX in the SJV and the second triggering event 
would achieve additional reductions of 0.1078 tpd direct 
PM2.5 and 0.0148 tpd NOX.\73\
---------------------------------------------------------------------------

    \73\ SJV PM2.5 Contingency Measure SIP, p. C-15.
---------------------------------------------------------------------------

3. EPA Evaluation
    Through the revisions adopted by the District to Rule 4901 on May 
18, 2023, the District has corrected the deficiencies in the 
contingency provision of Rule 4901 that we identified in our November 
26, 2021 final actions. Namely, the contingency provision in the rule 
(section 5.7.3) has been revised to address all the determinations for 
which contingency measures are required under 40 CFR 51.1014(a) and has 
been revised to achieve emissions reductions under all circumstances, 
i.e., if triggered by one of the specific EPA determinations. In 
addition, we find that the contingency provision in section 5.7.3 of 
Rule 4901 is surplus to the RFP and attainment demonstrations for the 
annual 1997 PM2.5 NAAQS based on the conclusions in our 
recent final action approving the RFP and attainment demonstrations in 
the State's 15 [mu]g/m\3\ SIP Revision.\74\
---------------------------------------------------------------------------

    \74\ EPA, ``Air Quality State Implementation Plans; Approvals 
and Promulgations: California; 1997 Annual Fine Particulate Matter 
Serious and Clean Air Act Section 189(d) Nonattainment Area 
Requirements; San Joaquin Valley, CA,'' Final rule, signed December 
5, 2023.
---------------------------------------------------------------------------

    In our previous actions, we found that the contingency provision in 
Rule 4901 met the other specific criteria used to evaluate contingency 
measures.\75\ Specifically, the contingency provision in Rule 4901 (the 
Residential Wood Burning Contingency Measure) is structured to be both 
conditional and prospective, to be implemented quickly following a 
triggering event (i.e., within 60 days) and to be implemented without 
significant further action by the State or the EPA. The revisions to 
section 5.7.3 of Rule 4901 that were adopted on May 18, 2023 do not 
affect those features of the contingency provision, and thus we propose 
to re-affirm those findings in this proposed rule.
---------------------------------------------------------------------------

    \75\ See, e.g., 86 FR 38652, 38669.
---------------------------------------------------------------------------

    We also note that the contingency provisions do not require the 
replacement or installation of an emissions control device and can 
therefore achieve emission reductions upon the rule taking effect. For 
example, if the EPA were to determine that the San Joaquin Valley 
failed to attain a given PM2.5 NAAQS, effective in July of a 
given year, the more stringent curtailment thresholds would take effect 
in September of that year, prior to the seasonal start of the No Burn 
Day program on November 1st. Thus, the emission reductions from the 
Residential Wood Burning Contingency Measure would be achieved within 
one year of the triggering event. Based on our review of the 
contingency provisions, as revised, we propose to re-affirm those 
findings.
    Contingency measures must also be designed to provide emissions 
reductions (if triggered) that are not otherwise required to meet other 
attainment plan requirements and not relied upon to demonstrate RFP and 
attainment. In this regard, we note that none of the SJV plans for the 
1997 annual, 2006 24-hour, and 2012 annual PM2.5 NAAQS 
relied upon the contingency provision in Rule 4901 to meet any plan 
element (other than the contingency measure element) and that none of 
the plans relied on the related emissions reductions from the 
contingency provision to provide for RFP or attainment. Based on our 
previous approvals of the San Joaquin Valley plans for the 2006 24-hour 
PM2.5 NAAQS in 2020 and 2012 annual PM2.5 NAAQS 
in 2021,\76\ and the recent approval of the San Joaquin Valley plan for 
the 1997 annual PM2.5 NAAQS, including the various plan 
elements such as the BACM, RFP, and attainment demonstrations, we find 
that the Residential Wood Burning Contingency Measure is not otherwise 
required for these PM2.5 NAAQS and that the associated 
emissions reductions would be surplus to the PM2.5-related 
RFP and attainment needs of the San Joaquin Valley.
---------------------------------------------------------------------------

    \76\ 85 FR 44192 and 86 FR 67343.
---------------------------------------------------------------------------

    Therefore, for the reasons provided in the preceding paragraphs, we 
propose to approve Rule 4901, as revised, because we find that the 
Residential Wood Burning Contingency Measure set forth in section 5.7.3 
of the rule now meets all the applicable requirements for a contingency 
measure for the San Joaquin Valley for the 1997 annual, 2006 24-hour, 
and 2012 annual PM2.5 NAAQS.
    Lastly, we reviewed the emissions reduction estimates for the 
Residential Wood Burning Contingency Measure that were prepared by the 
District and included in Appendix C (``Emission Reduction Analysis for 
Rule 4901'') of the SJV PM2.5 Contingency Measure SIP and 
find the estimates to be reasonable and adequately documented. As 
described in Appendix C of the SJV PM2.5 Contingency Measure 
SIP, the District has estimated the reductions from the two triggering 
events provided for in the Residential Wood Burning Contingency Measure 
by taking into account many different factors, such as the number of 
fireplaces and wood stoves in the individual counties within

[[Page 87997]]

the San Joaquin Valley, the different types of wood stoves (registered 
and unregistered, certified and uncertified), and the number of 
additional curtailment days under various scenarios, among other 
factors. Taking into account these various factors, the District 
estimates the Residential Wood Burning Contingency Measure would 
achieve annual average emissions reductions of 0.5793 tpd direct 
PM2.5 and 0.0817 tpd NOX in the SJV following the 
first triggering event and additional reductions of 0.1078 tpd direct 
PM2.5 and 0.0148 tpd NOX following the second 
triggering event.
    Because we are proposing to find that the Residential Wood Burning 
Contingency Measure meets the requirements for individual contingency 
measures, the associated emissions reductions can be taken into account 
by the EPA when determining whether CARB and the District have met the 
requirements for the San Joaquin Valley as a whole with respect to the 
contingency measure SIP requirements of CAA section 172(c)(9) and 40 
CFR 51.1014 for PM2.5 nonattainment areas. Section V of this 
document presents our evaluation of the SJV PM2.5 
Contingency Measure SIP for compliance with these requirements for the 
San Joaquin Valley for the 1997 annual, 2006 24-hour, and 2012 annual 
PM2.5 NAAQS, and, as part of that evaluation, we have taken 
into account the District's estimates of emissions reductions from the 
Residential Wood Burning Contingency Measure.

B. Rural Open Areas Contingency Measure

1. Background and Regulatory History
    In areas where there is open, uncovered land, a natural crust will 
form and minimize dust emissions. However, activities such as 
earthmoving activities, material dumping, weed abatement, and vehicle 
traffic will disturb otherwise naturally stable land and allow 
windblown fugitive dust emissions to occur.
    The District adopted fugitive dust control requirements in 
Regulation VIII (containing the 8000 series rules) on November 15, 
2001, to address RACM/RACT and BACM/BACT attainment plan requirements 
for the 1987 p.m.10 NAAQS.\77\ The EPA found that new 
provisions in Regulation VIII ``significantly strengthened'' the prior 
existing rules by tightening standards, covering more activities, and 
adding more requirements to control dust-producing activities.\78\ 
Subsequently, the District adopted amendments to Regulation VIII on 
August 19, 2004, and September 16, 2004, that the EPA approved into the 
San Joaquin Valley portion of the California SIP in 2006.\79\ More 
recently the EPA has reviewed Regulation VIII for RACM/RACT, BACM/BACT, 
and MSM requirements in acting on the San Joaquin Valley plan for the 
2006 24-hour PM2.5 NAAQS.\80\
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    \77\ Regulation VIII includes eight rules. Rule 8011 (``General 
Requirements'') provides definitions and the general requirements on 
which the seven other rules rely. In turn, those seven rules apply 
to different sources of fugitive windblown dust based on activity 
type. They include Rule 8021 (``Construction, Demolition, 
Excavation, Extraction, and Other Earthmoving Activities''), Rule 
8031 (``Bulk Materials''), Rule 8041 (``Carryout and Trackout''), 
Rule 8051 (``Open Areas''), Rule 8061 (``Paved and Unpaved Roads''), 
Rule 8071 (Unpaved Vehicle/Equipment Traffic Area''), and Rule 8081 
(``Agricultural Sources''). In this proposed rule, the EPA proposes 
to approve Rule 8051, as amended to include a contingency provision, 
as a revision to the California SIP.
    \78\ 67 FR 15345, 15346-15447 (April 1, 2002) (proposed rule on 
2001 version of Regulation VIII).
    \79\ 71 FR 8461 (February 17, 2006).
    \80\ See, e.g., 85 FR 17382, 17431 (March 27, 2020) (proposal on 
BACM/BACT and MSM for the 2006 24-hour PM2.5 NAAQS); and 
EPA Region IX, ``Technical Support Document, EPA Evaluation of BACM/
MSM, San Joaquin Valley PM2.5 Plan for the 2006 
PM2.5 NAAQS,'' February 2020.
---------------------------------------------------------------------------

    Among the rules of Regulation VIII, Rule 8051 (``Open Areas'') 
applies to vacant portions of residential and commercial lots and 
contiguous parcels and the 2004 amendments added applicability 
thresholds for rural and urban areas required to meet both the 
conditions for a stabilized surface (defined in Rule 8011) and a 20% 
opacity standard. Rule 8051 applies to any open area having 0.5 acres 
or more within urban areas, or 3.0 acres or more within rural areas, 
that contains at least 1,000 square feet of disturbed surface area.\81\ 
In addition, under Rule 8051, upon evidence of vehicle trespass, 
owners/operators must apply a measure(s) that effectively prevents 
access to the lot. Rule 8051 does not apply to agricultural areas, 
which are subject to other fugitive dust controls such as those under 
Rule 4550 (``Conservation Management Practices'') and Rule 8081 
(``Agricultural Sources'').
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    \81\ Rule 8051, section 2.1.
---------------------------------------------------------------------------

2. Summary of State Submission
    On September 21, 2023, the District adopted a new contingency 
measure in section 7.0 of District Rule 8051 (referred to herein as the 
``Rural Open Areas Contingency Measure''), and CARB submitted Rule 
8051, as amended, to include the Rural Open Areas Contingency Measure, 
as a supplement to the SJV PM2.5 Contingency Measure SIP. 
The Rural Open Areas Contingency Measure would be triggered by a final 
determination by the EPA that the District failed to meet one or more 
of the following triggering events for the applicable PM2.5 
NAAQS:
    (1) Any Reasonable Further Progress requirement;
    (2) Any quantitative milestone;
    (3) Submission of a quantitative milestone report; or
    (4) Attainment of the applicable PM2.5 NAAQS by the 
applicable attainment date.
    The Rural Open Areas Contingency Measure would lower the 
applicability threshold for rural open areas from 3.0 acres to 1.0 
acres, thereby reducing windblown fugitive dust, including the direct 
PM2.5 portion of such dust emissions. The State estimates 
that the newly subject total acreage would be 18,816 acres. The Rural 
Open Areas Contingency Measure would be effective 60 days after an EPA 
determination under 40 CFR 51.1014(a) that triggers contingency 
measures. At such time, Rule 8051 would require any rural open area 
having 1.0 acre or more and containing at least 1,000 square feet of 
disturbed surface area (notwithstanding exemptions in section 4.0 of 
the rule) to meet section 5.0 of the rule, which requires that:

    Whenever open areas are disturbed or vehicles are used in open 
areas, an owner/operator shall implement one or a combination of 
control measures indicated in Table 8051-1 to comply with the 
conditions of a stabilized surface at all times and to limit VDE to 
20% opacity. In addition to the requirements of this rule, a person 
shall comply with all other applicable requirements of Regulation 
VIII.\82\
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    \82\ VDE is Visible Dust Emissions.

    Table 8051-1 contains the following control measures for open 
---------------------------------------------------------------------------
areas:

    A. Open Areas:
    Implement, apply, maintain, and reapply if necessary, at least 
one or a combination of the following control measures to comply at 
all times with the conditions for a stabilized surface and limit VDE 
to 20% opacity as defined in Rule 8011:
    A1. Apply and maintain water or dust suppressant(s) to all 
unvegetated areas; and/or
    A2. Establish vegetation on all previously disturbed areas; and/
or
    A3. Pave, apply and maintain gravel, or apply and maintain 
chemical/organic stabilizers/suppressant(s).
    B. Vehicle Use in Open Areas:
    Upon evidence of trespass, prevent unauthorized vehicle access 
by:
    Posting `No Trespassing' signs or installing physical barriers 
such as fences, gates, posts, and/or other appropriate barriers to 
effectively prevent access to the area.

    The Rural Open Areas Contingency Measure is narrowed by the 
addition of

[[Page 87998]]

a new exemption in section 4.2 of Rule 8051 that exempts owners or 
operators of rural parcels between 1.0 acres to 3.0 acres that 
implement fire prevention activities required by a Federal, State, or 
local agency by mowing or cutting (if three inches or more of stubble 
remains after moving or cutting) or discing (if no more than two passes 
are made).
    The District estimates that the Rural Open Burning Contingency 
Measure would achieve annual average emissions reductions of 0.008 tpd 
direct PM2.5.\83\
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    \83\ SJVUAPCD, Final Draft Staff Report, ``Proposed Amendments 
to Rule 8051 (Open Areas),'' September 21, 2023, p. B-7.
---------------------------------------------------------------------------

3. EPA Evaluation
    As discussed further in the EPA's technical support document that 
documents our evaluation of amended Rule 8051,\84\ we find that the 
Rural Open Areas Contingency Measure now included as section 7.0 of 
Rule 8051 meets the applicable requirements for contingency measures. 
First, we note that the expansion of the control requirements to rural 
parcels between one (1.0) to three (3.0) acres under section 7.0 of 
Rule 8051 is conditional and prospective by design and is not required 
to meet existing control requirements (i.e., RACM or BACM) \85\ nor 
relied upon by the area as part of the area's PM2.5 RFP or 
attainment demonstrations. Moreover, the exemption for owners or 
operators of certain rural parcels of 1.0 to 3.0 acres in size from the 
requirements of the rule that would otherwise be included if the Rural 
Open Areas Contingency Measure were triggered is narrowly drawn and 
limited such that the exemption will have essentially no impact on the 
emissions reductions expected from implementation of the Rural Open 
Areas Contingency Measure. This is because the exemption applies only 
to owners and operators acting in response to a Federal, State, or 
local agency that is requiring implementation of fire prevention 
activities and is further limited by specifying the methods that must 
be followed to be covered by the exemption.
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    \84\ EPA Region IX, ``Technical Support Document for EPA's 
Rulemaking for the California State Implementation Plan, San Joaquin 
Valley Air Pollution Control District Rule 8051 (`Open Areas'),'' 
December 2023.
    \85\ As noted previously, the RACM and BACM demonstrations that 
the EPA has approved for the 1997 annual, 2006 24-hour, and the 2012 
annual PM2.5 NAAQS included review of Regulation VIII, 
including Rule 8051. See 85 FR 44192, 86 FR 67343, and EPA, ``Air 
Quality State Implementation Plans; Approvals and Promulgations: 
California; 1997 Annual Fine Particulate Matter Serious and Clean 
Air Act Section 189(d) Nonattainment Area Requirements; San Joaquin 
Valley, CA,'' Final rule, signed December 5, 2023.
---------------------------------------------------------------------------

    Second, the Rural Open Areas Contingency Measure includes a trigger 
mechanism (``. . . final determination by EPA that the District has 
failed to meet any of the following elements for any of the 
PM2.5 NAAQS . . .'') that addresses all of the specific 
types of determinations listed in 40 CFR 51.1014(a). Third, the Rural 
Open Areas Contingency Measure specifies a schedule for timely 
implementation (``Upon 60 days after the issuance of a final 
determination . . .''). While the extension of the control requirements 
to rural parcels between 1.0 to 3.0 acres under section 7.0 is self-
executing (i.e., does not require additional rulemaking), the District 
will need as a practical matter to provide notice to the affected 
owners/operators that the contingency measure has been triggered. 
However, we do not find that providing such notice constitutes 
``further action'' by the state for the purposes of CAA section 
172(c)(9). Lastly, given the nature of the controls required under Rule 
8051 (such as watering, establishing vegetation, applying gravel, or 
fencing (if needed)), we find that the associated emissions reductions 
from implementation of the Rural Open Areas Contingency Measure can be 
achieved within a year of the triggering event.
    Therefore, for the reasons provided in the preceding paragraphs, we 
propose to approve Rule 8051, as revised, because we find that the 
Rural Open Areas Contingency Measure meets all the applicable 
requirements for a contingency measure for the San Joaquin Valley for 
the 1997 annual, 2006 24-hour, and 2012 annual PM2.5 NAAQS.
    We have also reviewed the emissions reduction estimates for the 
Rural Open Areas Contingency Measure that were prepared by the District 
and included in Appendix B (``Emission Reduction and Cost Effectiveness 
Analysis for Proposed Amendments to Rule 8051 (Open Areas)'') of the 
Final Draft Staff Report and find the estimates to be reasonable and 
adequately documented. As documented in Appendix B of the Final Draft 
Staff Report, the District took into account county-specific parcel 
size data, among other relevant factors to develop the emissions 
reduction estimate of 0.008 tpd of direct PM2.5 for the 
Rural Open Areas Contingency Measure.\86\
---------------------------------------------------------------------------

    \86\ SJVUAPCD, Final Draft Staff Report, ``Proposed Amendments 
to Rule 8051 (Open Areas),'' September 21, 2023, p. B-7. The 
District's estimate compares favorably with the EPA's own estimate 
of 0.01 tpd for essentially the same contingency measure in EPA's 
proposed PM2.5 contingency measure FIP for San Joaquin 
Valley. 88 FR 53431, 53444.
---------------------------------------------------------------------------

    Because we are proposing to find that the Rural Open Areas 
Contingency Measure meets the requirements for individual contingency 
measures, the associated emissions reductions can be taken into account 
by the EPA when determining whether CARB and District have met the 
requirements for the San Joaquin Valley as a whole with respect to the 
contingency measure requirements of CAA section 172(c)(9) and 40 CFR 
51.1014 for PM2.5 nonattainment areas. Section V of this 
document presents our evaluation of the SJV PM2.5 
Contingency Measure SIP for compliance with these requirements for the 
San Joaquin Valley for the 1997 annual, 2006 24-hour, and 2012 annual 
PM2.5 NAAQS, and, as part of that evaluation, we have taken 
into account the District's estimates of emissions reductions from the 
Rural Open Areas Contingency Measure.

C. Smog Check Contingency Measure

    The general purpose of motor vehicle inspection and maintenance (I/
M) programs is to reduce emissions from in-use motor vehicles in need 
of repairs and thereby contribute to state and local efforts to improve 
air quality and to attain the NAAQS. California has operated an I/M 
program, also known as the ``Smog Check'' program, in certain areas of 
the state for over 30 years. Under the current California Smog Check 
program, certain vehicles are exempt from the biennial inspection 
requirement, including vehicles eight or fewer model years old.
    On November 13, 2023, CARB submitted a third contingency measure 
for San Joaquin Valley for the PM2.5 NAAQS, which we refer 
to herein as the Smog Check Contingency Measure. Under the Smog Check 
Contingency Measure, CARB would, within 30 days of the effective date 
of an EPA determination that an applicable triggering event has 
occurred for San Joaquin Valley for the PM2.5 NAAQS, 
transmit a letter to the California Bureau of Automotive Repair and 
Department of Motor Vehicles that, in effect, would narrow the newer 
vehicle exemption from eight or fewer model years old to seven or fewer 
model years old throughout the San Joaquin Valley.\87\ CARB estimates 
that the Smog Check Contingency Measure would, after the first 
triggering event and adjusting slightly for the effect on foregone 
emission reductions from Carl Moyer

[[Page 87999]]

funding,\88\ achieve annual average emission reductions of 0.113 tpd 
NOX for the 1997 annual PM2.5 NAAQS, 0.116 tpd 
NOX for the 2006 24-hour PM2.5 NAAQS, and 0.083 
tpd NOX for the 2012 annual PM2.5 NAAQS in the 
San Joaquin Valley.\89\
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    \87\ Smog Check Contingency Measure, section 4. The Smog Check 
Contingency Measure is structured to further narrow the newer 
vehicle exemption by another year upon a second triggering event.
    \88\ The Carl Moyer Program distributes incentive grants to fund 
the incremental cost of cleaner-than-required engines, equipment, 
and other technology. The slight adjustment to emission reductions 
mentioned results from a decrease in funding to the Carl Moyer 
program. If the contingency measure were triggered, fewer vehicles 
would be exempt from the Smog Check program, and thus fewer vehicles 
would be subject to the Smog Check abatement fee (which is only 
assessed on vehicles exempted from Smog Check testing). That fee 
provides funding to the Carl Moyer Program. For more information on 
the program, see https://ww2.arb.ca.gov/carl-moyer-program-apply.
    \89\ Smog Check Contingency Measure, Table 28 and Table 31.
---------------------------------------------------------------------------

    In a separate proposed rule published in this Federal Register, we 
are proposing to approve the Smog Check Contingency Measure and, 
therefore, its associated emissions reductions can be taken into 
account by the EPA when determining whether the State and District have 
met the contingency measure requirements of CAA section 172(c)(9) and 
40 CFR 51.1014 for PM2.5 nonattainment areas for the San 
Joaquin Valley as a whole. Section V of this document presents our 
evaluation of the SJV PM2.5 Contingency Measure SIP for 
compliance with these requirements for the San Joaquin Valley for the 
1997 annual, 2006 24-hour, and 2012 annual PM2.5 NAAQS, and 
as part of that evaluation, we have taken into account CARB's estimates 
of emissions reductions from the Smog Check Contingency Measure.

V. EPA Review of San Joaquin Valley PM2.5 Contingency Measure Plan 
Element

A. Background and Regulatory History

    In light of the nonattainment designation for San Joaquin Valley 
for the PM2.5 NAAQS, the State of California was required 
under CAA section 172(c)(9) and 40 CFR 51.1014 to adopt and submit a 
SIP revision providing for implementation of contingency measures to 
take effect in the San Joaquin Valley if the EPA determines that the 
area has failed to meet an RFP requirement, failed to submit a 
quantitative milestone report, failed to meet a quantitative milestone, 
or failed to attain the PM2.5 NAAQS by the applicable 
attainment date.
    In 2019, as discussed in section I.B of this document, CARB 
submitted a SIP revision that included contingency measure plan 
elements for San Joaquin Valley for the 1997 annual and 24-hour, 2006 
24-hour, and 2012 annual PM2.5 NAAQS. The contingency 
measure plan elements relied on an earlier version of the Residential 
Wood Burning Contingency Measure and justified reliance on that single 
measure notwithstanding the fact that the measure alone would not 
achieve emissions reductions equivalent to one year's worth of RFP by 
reference to larger planning context for the area and related surplus 
emissions reductions expected to be achieved from already-implemented 
control measures.
    In 2021, the EPA disapproved the contingency measure plan elements 
for the applicable PM2.5 NAAQS because the plan elements did 
not include a contingency measure that addressed all four triggering 
events for the PM2.5 NAAQS under 40 CFR 51.1014; that would 
ensure that emissions reductions would be achieved, once triggered; or, 
for the 1997 annual PM2.5 NAAQS, that would be surplus to 
the area's needs for RFP and attainment.\90\ We proposed disapproval of 
the contingency measure elements before the Ninth Circuit's Assoc. of 
Irritated Residents (AIR) v. EPA decision \91\ was published and, thus, 
did not identify the contingency measure elements' reliance on surplus 
emissions reductions from already-implemented measures (to justify 
adoption of a single contingency measure which would not, on its own, 
achieve one year's worth of RFP) as a specific deficiency.
---------------------------------------------------------------------------

    \90\ 86 FR 38652, 38669-38670; and 86 FR 49100, 49124-49125 and 
49133-49134.
    \91\ In AIR v. EPA, the Ninth Circuit held that, under the EPA's 
current guidance, the surplus emissions reductions from already-
implemented measures cannot be relied upon to justify the approval 
of a contingency measure that would achieve far less than one year's 
worth of RFP as sufficient by itself to meet the contingency measure 
requirements of CAA sections 172(c)(9) and 182(c)(9) for the 
nonattainment area. 10 F.4th at 946-47.
---------------------------------------------------------------------------

B. Summary of State Submission

    In response to the disapprovals of the previous contingency measure 
elements, the District and CARB prepared the SJV PM2.5 
Contingency Measure SIP, which CARB adopted as part of the California 
SIP and submitted for EPA approval on June 8, 2023. In the SJV 
PM2.5 Contingency Measure SIP, the District and CARB present 
their evaluation of potential contingency measures, amendments to the 
previous contingency provisions in the District's residential wood 
burning rule (i.e., the Residential Wood Burning Contingency Measure), 
a commitment to evaluate potential contingency provisions for Rule 8051 
(``Open Areas''), analysis of one year's worth of emission reductions, 
and infeasibility demonstrations for rejecting other potential 
contingency measures. In light of the AIR v. EPA decision, the District 
and CARB do not justify the selection of the contingency measures on 
the basis of surplus emissions reductions from already-implemented 
measures, as had been the case previously, but rather ``due to a 
scarcity of available, qualifying measures,'' and the time period in 
which emission reductions should occur.\92\ Subsequent to the 
submission of the SJV PM2.5 Contingency Measure SIP, the 
District and CARB have supplemented the contingency measure elements 
for the applicable PM2.5 NAAQS with the adoption and 
submission of two additional contingency measures--the Rural Open Areas 
Contingency Measure and the Smog Check Contingency Measure.
---------------------------------------------------------------------------

    \92\ SJV PM2.5 Contingency Measure SIP, p. 5.
---------------------------------------------------------------------------

1. General Considerations
    ``General Considerations,'' for the purposes of this proposed 
action, includes identification of the relevant pollutants, the use of 
contingency measures for more than one triggering event and for more 
than one NAAQS, and the magnitude of emissions reductions. Contingency 
measure feasibility analyses are addressed in a separate subsection.
a. PM2.5 and PM2.5 Precursors
    CARB and the District have concluded, based on CARB modeling, that 
sulfur oxides (SOX), volatile organic compounds (VOCs), and 
ammonia are not significant precursors for PM2.5 formation 
in the San Joaquin Valley. Therefore, their contingency measure 
submissions address sources of direct PM2.5 and 
NOX emissions.

b. Using Same Contingency Measures for More Than One Triggering Event, 
NAAQS

    The contingency measures that CARB and the District rely upon in 
the SJV PM2.5 Contingency Measure SIP are not limited to one 
PM2.5 NAAQS, but rather cover all three of the 1997 annual, 
2006 24-hour, and 2012 annual PM2.5 NAAQS (i.e., the same 
set of contingency measures has been submitted to address the 
contingency measure requirements for more than one PM2.5 
NAAQS).
c. Magnitude of Emissions Reductions
    To evaluate the sufficiency of the Residential Wood Burning 
Contingency Measure with respect to the magnitude of emissions 
reductions that the contingency measures should achieve, the SJV 
PM2.5 Contingency Measure SIP

[[Page 88000]]

includes calculations of one year's worth of RFP for the relevant 
PM2.5 NAAQS for the San Joaquin Valley. To do this, the 
District calculated the change in annual average emission reductions 
from the base year to the attainment year for the 1997 annual 
PM2.5 NAAQS (from 2013 to 2023) and 2006 24-hour 
PM2.5 NAAQS (from 2013 to 2024), and the outermost Moderate 
area RFP year for the 2012 annual PM2.5 NAAQS (from 2013 to 
2022), and divided those by the number of years between the base year 
and applicable attainment or RFP year. The State's estimates of one 
year's worth of RFP in the SJV PM2.5 Contingency Measure SIP 
are as follows: 0.44 tpd direct PM2.5 and 16.7 tpd 
NOX (for the 1997 annual PM2.5 NAAQS); 0.58 tpd 
direct PM2.5 and 18.4 tpd NOX (for the 2006 24-
hour PM2.5 NAAQS); and 0.46 tpd direct PM2.5 and 
15.3 tpd NOX (for the 2012 annual PM2.5 
NAAQS).\93\
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    \93\ SJV PM2.5 Contingency Measure SIP, pp. 5-6; see 
``Step 1b'' emissions estimates in the ``Step 1'' table for one 
year's worth of RFP.
---------------------------------------------------------------------------

    Per the EPA's Draft Revised Contingency Measure Guidance, the SJV 
PM2.5 Contingency Measure SIP also includes estimates of one 
year's worth of progress that were made by calculating one year's worth 
of RFP as a percentage of the base year emissions inventory and 
applying that percentage to the attainment year emissions inventory for 
the 1997 annual and 2006 24-hour PM2.5 NAAQS, and to the 
outermost Moderate area RFP year for the 2012 annual PM2.5 
NAAQS. The estimates of one year's worth of progress in the SJV 
PM2.5 Contingency Measure SIP are as follows: 0.41 tpd 
direct PM2.5 and 7.91 tpd NOX (for the 1997 
annual PM2.5 NAAQS); 0.52 tpd direct PM2.5 and 
6.66 tpd NOX (for the 2006 24-hour PM2.5 NAAQS); 
and 0.43 tpd direct PM2.5 and 8.65 tpd NOX (for 
the 2012 annual PM2.5 NAAQS).\94\
---------------------------------------------------------------------------

    \94\ SJV PM2.5 Contingency Measure SIP, pp. 5-6; see 
the ``Step 3'' table for one year's worth of progress.
---------------------------------------------------------------------------

    CARB and the District present their comparison of emission 
reductions from the Residential Wood Burning Contingency Measure to 
those needed for one year's worth of progress in Table 17 of the SJV 
PM2.5 Contingency Measure SIP.\95\ They conclude that this 
contingency measure would achieve emission reductions of 0.69 tpd 
direct PM2.5 and 0.1 tpd NOX (including 
reductions following both first and second triggering events) and that 
such reductions would exceed those needed for one year's worth of 
progress for direct PM2.5 but would fall short of those 
needed for one year's worth of progress for NOX.
---------------------------------------------------------------------------

    \95\ SJV PM2.5 Contingency Measure SIP, Table 17.
---------------------------------------------------------------------------

    Noting the direct PM2.5 surplus, CARB and the District 
then trade the surplus direct PM2.5 emission reductions at a 
ratio of 6:1 (i.e., 6 tpd NOX for each excess 1 tpd direct 
PM2.5),\96\ based on analyses in their 2021 ``Progress 
Report and Technical Submittal for the 2012 PM2.5 Standard 
San Joaquin Valley'' (``2021 Progress Report'').\97\ CARB and the 
District note that direct PM2.5 emission reductions are a 
more efficient and cost-effective way to reduce ambient 
PM2.5 in the San Joaquin Valley than NOX emission 
reductions.\98\ The report presented analysis of the relative effect of 
reducing 30% direct PM2.5 (annual average) emissions versus 
30% NOX (annual average) emissions on ambient annual average 
PM2.5 concentrations (as modeled for 2024) at each 
regulatory monitoring site in the San Joaquin Valley using data from 
the precursor sensitivity analyses in the 2018 PM2.5 
Plan.\99\ CARB and the District examined several methods for 
calculating the ratio based on varying combinations of monitoring 
sites. They concluded that 6:1 was a conservative ratio as it was less 
than the average ratio for the two sites with the highest modeled 
(annual average) ambient PM2.5 concentrations in 2025 
(6.1:1), the average ratio of sites with modeled 2025 concentrations 
over 11.00 [mu]g/m\3\ (6.4:1), and the average ratio of sites with a 
2020 design value over 12 [mu]g/m\3\ (6.6:1).\100\ They also conclude 
that a ratio of 6:1 would be conservative as it was less than the 8.1:1 
ratio for the modeled design value for the Bakersfield-Planz site 
(i.e., the site with the highest modeled 2025 concentration).
---------------------------------------------------------------------------

    \96\ SJV PM2.5 Contingency Measure SIP, pp. 73-74.
    \97\ CARB and SJVUAPCD, ``Progress Report and Technical 
Submittal for the 2012 PM2.5 Standard San Joaquin 
Valley,'' October 19, 2021 (``2021 Progress Report''). See pages 34-
38 for the State's ``PM2.5 Precursor Sensitivity Modeling 
Analysis and Trading Ratios.'' Transmitted to the EPA by letter 
dated October 20, 2021, from Richard W. Corey, Executive Officer, 
CARB, to Deborah Jordan, Acting Regional Administrator, EPA Region 
IX.
    \98\ 2021 Progress Report, p. 34.
    \99\ See Appendix K (``Modeling Attainment Demonstration'') of 
the 2018 PM2.5 Plan, including Table 14 (annual average 
modeled emissions inventory) and Table 49 (precursor sensitivity 
analysis for annual average ambient PM2.5 concentration 
in 2024).
    \100\ At the time, the modeled 2025 PM2.5 
concentrations corresponded to the attainment year in the State's 
Serious area plan for the 2012 annual PM2.5 NAAQS, which 
was later withdrawn on October 27, 2022. Letter dated October 27, 
2022, from Steven S. Cliff, Executive Officer, CARB, to Martha 
Guzman, Regional Administrator, EPA Region IX.
---------------------------------------------------------------------------

    Applying this 6:1 trading ratio, CARB and the District estimate 
that, after achieving the full one year's worth of progress for direct 
PM2.5 emission reductions, the shortfall of NOX 
emissions for one year's worth of progress would be as follows: 6.13 
tpd (compared to 7.91 tpd for the 1997 annual PM2.5 NAAQS), 
5.54 tpd (compared to 6.66 tpd for the 2006 24-hour PM2.5 
NAAQS), and 6.99 tpd (compared to 8.65 tpd for the 2012 annual 
PM2.5 NAAQS).\101\ The NOX equivalent emissions 
reductions equate to a range of 17% to 23% of one year's worth of 
progress for NOX.
---------------------------------------------------------------------------

    \101\ SJV PM2.5 Contingency Measure SIP, p. 74.
---------------------------------------------------------------------------

    In light of the shortfall of NOX emissions reductions, 
the SJV PM2.5 Contingency Measure SIP includes feasibility 
analyses by the District for stationary and area sources and by CARB 
for mobile sources to justify the reliance on a contingency measure 
that would not provide for one year's worth of progress (i.e., for 
NOX). We summarize the feasibility analyses prepared by the 
District and CARB in the following section of this document.
2. Contingency Measure Feasibility Analyses
    The District states that it has already implemented rules for 
sources that meet or go beyond federal requirements and that few 
measures remain to explore as contingency measures. The District 
describes the relative stringency of their stationary and area source 
measures by noting the EPA's 2020 approval of the State's demonstration 
of BACM and MSM for the 2006 24-hour PM2.5 NAAQS; highlights 
the District's tighter limits for certain industrial sources compared 
to the EPA's national emission limits to address the interstate 
transport of air pollution; and describes the numerous regulatory 
measures and incentive-based measures adopted since and in fulfillment 
of the 2018 PM2.5 Plan.\102\
---------------------------------------------------------------------------

    \102\ SJV PM2.5 Contingency Measure SIP, section 4.1 
(``Stringency of District's Regulatory Program''). See also 87 FR 
20036 (April 6, 2022) (proposed rule for the interstate transport 
FIP for the 2015 ozone NAAQS); and 88 FR 36654 (June 5, 2023) (final 
rule for interstate transport FIP for the 2015 ozone NAAQS).
---------------------------------------------------------------------------

    More specifically, the District analyzed the wide range of 
stationary and area sources for contingency measure opportunities, 
including identification of potential control measures, analysis of the 
technological and economic feasibility of such measures, assessment of 
the time required to develop and implement such measures within 60 days 
and achieve emission reductions within one to two years, and discussion 
of whether the District could adopt such measures

[[Page 88001]]

and secure EPA approval prior to the EPA promulgating a contingency 
measure FIP for PM2.5 in the San Joaquin Valley. For the 
potential control measures identified through this process, the 
District further analyzed possible contingency measures for wood 
burning fireplaces and wood burning heaters, rural open areas, 
commercial charbroiling, almond harvesting, and oil and gas production 
combustion equipment. Based on this analysis, the District adopted the 
Residential Wood Burning Contingency Measure and concluded that the 
other possible contingency measures were infeasible or untimely but 
committed to further evaluate the rural open areas rule as a potential 
contingency measure. Subsequently, the District fulfilled the Agency's 
commitment to further evaluate the rural open areas rule and adopted 
the Rural Open Areas Contingency Measure to supplement the SJV 
PM2.5 Contingency Measure SIP.
    In turn, CARB states that its mobile source control programs often 
set the standard for other states to follow and that more than half of 
mobile source NOX emissions in the San Joaquin Valley are 
from primarily federally regulated sources, which limit opportunities 
for contingency measures that would achieve one year's worth of 
progress in emission reductions. CARB further notes that a relatively 
limited portion (of NOX) emissions are regulated by local 
air districts in California and that, even if discounting the emission 
reductions needed for contingency measures by primarily federally 
regulated emission sources, additional control measures to achieve the 
one year's worth of emission reductions are scarce or nonexistent.
    CARB states that if such measures were identified, they would be 
adopted to improve air quality and help attain the NAAQS, rather than 
held in reserve as contingency measures, and that control measures to 
achieve large emission reductions often take longer than two years to 
implement--beyond the one- to two-year timeframe for achieving emission 
reductions for contingency purposes. For example, CARB states that the 
three largest NOX reduction measures committed to in the 
2022 State SIP Strategy \103\ rely on accelerated turnover of engines 
and trucks and shifting to zero-emission equipment, which is limited by 
infrastructure and equipment options. CARB further states that a 
central difficulty in considering contingency measures is that CARB has 
already committed to zero emission standards where feasible and as 
expeditiously as possible to fulfill goals established in California 
Executive Order N-79-20 for mobile sources ranging from light-duty cars 
by 2035 to heavy-duty trucks by 2045.\104\
---------------------------------------------------------------------------

    \103\ CARB, ``2022 State Strategy for the State Implementation 
Plan,'' adopted September 22, 2022, Chapter 5 (``State SIP 
Measures'').
    \104\ Executive Department, State of California, Executive Order 
N-79-20, September 23, 2020.
---------------------------------------------------------------------------

    More specifically, CARB analyzed all sources under its authority to 
identify potential contingency measures using three criteria, per CAA 
requirements, court decisions, and the EPA's Draft Revised Contingency 
Measure Guidance. First, CARB assessed whether the measure could be 
implemented within 60 days of a triggering event and emission 
reductions achieved within one to two years. Second, CARB assessed the 
technological and economic feasibility of implementing the measure, 
particularly within the one- to two-year timeframe. Third, CARB 
evaluated whether it could adopt the measure and secure EPA approval by 
the September 30, 2024 consent decree deadline for the EPA to 
promulgate a FIP or alternatively approve contingency measure SIP 
submissions meeting the contingency measure requirements.
    Regarding mobile source contingency measures, CARB describes 
several challenges that limit the control measure options that would 
meet contingency measure requirements. For new engine standards, CARB 
states that engine manufacturers need lead time to ``design, plan, 
certify, manufacture, and deploy cleaner engines.'' For fleet 
regulations, CARB states that manufacturing must be mature to provide 
sufficient supply and that owners and operators must ``plan, purchase, 
and deploy new, often zero-emission, equipment'' that may involve 
changes to business operations and infrastructure. Based on the time 
required for implementing such measures, CARB concludes that new engine 
standards and fleet regulations are not appropriate for contingency 
measures.
    Furthermore, CARB states that its regulations are technology-
forcing, which requires time for industry to plan, develop, and 
implement new technologies, and that it is driving mobile sources to 
zero-emissions where feasible to achieve criteria, air toxic, and 
climate pollutant goals. Similarly, CARB argues that the technology-
forcing and zero-emission-based nature of its mobile source regulations 
reduce or eliminate opportunities for contingency measure emission 
reductions. Lastly, CARB states that its full rulemaking process for 
most mobile source measures takes about five years to develop and 
adopt, which would not be possible prior to the September 30, 2024 
consent decree deadline for the EPA to promulgate a FIP, or approve 
contingency measure SIP submissions meeting the contingency measure 
requirements.
    CARB concludes that there are no feasible mobile source contingency 
measures for the 1997 annual, 2006 24-hour, and 2012 annual 
PM2.5 NAAQS (as of the April 2023 public notice for the SJV 
PM2.5 Contingency Measure SIP) yet continued to assess 
opportunities for feasible contingency measures. Per a June 2023 
commitment letter by CARB's Executive Officer, and as further described 
in section IV.C of this proposed rule, CARB has since completed the 
development of and adopted the state-wide Smog Check Contingency 
Measure that complements the District contingency measures for 
residential wood burning and rural open areas.
3. Conclusion
    Based on achieving the full one year's worth of progress for direct 
PM2.5 emission reductions, a portion of one year's worth of 
progress for NOX emission reductions, and their contingency 
measure feasibility analyses, CARB and the District conclude that the 
SJV PM2.5 Contingency Measure SIP, and related infeasibility 
demonstrations, and the Residential Wood Burning Contingency Measure 
fulfill the contingency measure requirements for the PM2.5 
NAAQS.\105\
---------------------------------------------------------------------------

    \105\ SJV PM2.5 Contingency Measure SIP, p. 74. As 
noted previously, the SJV PM2.5 Contingency Measure SIP 
has been supplemented with two additional contingency measures 
(i.e., the Rural Open Areas Contingency Measure and the Smog Check 
Contingency Measure).
---------------------------------------------------------------------------

C. EPA Evaluation

    We propose to find that CARB and the District have corrected the 
specific deficiencies that we identified in the previously submitted 
contingency measure elements for the applicable PM2.5 NAAQS 
and that were the bases for our previous disapprovals of the 
contingency measure element. Our proposed conclusion in this regard 
recognizes that the revised contingency measure plan elements for the 
applicable PM2.5 NAAQS (SJV PM2.5 Contingency 
Measure SIP) now includes contingency measures (Residential Wood 
Burning Contingency Measure, Rural Open Areas Contingency Measure, and 
the Smog Check Contingency Measure) that address all four triggering 
events for the PM2.5 NAAQS under 40

[[Page 88002]]

CFR 51.1014, that have been structured to ensure emissions reductions, 
once triggered, and that are surplus to the RFP and attainment needs of 
the San Joaquin Valley for the 1997 annual PM2.5 NAAQS.\106\
---------------------------------------------------------------------------

    \106\ With respect to the contingency measures being surplus to 
the RFP and attainment needs of the San Joaquin Valley for the 1997 
annual PM2.5 NAAQS, we are relying on the recent approval 
of the RFP and attainment demonstrations in the State's 15 [mu]g/
m\3\ SIP Revision.
---------------------------------------------------------------------------

1. General Considerations
    As stated previously, ``General Considerations,'' for the purposes 
of this proposed action, includes identification of the relevant 
pollutants, the use of contingency measures for more than one 
triggering event and for more than one NAAQS, and the magnitude of 
emissions reductions. We present our evaluation of the State's 
contingency measure feasibility analyses in a separate subsection.
a. PM2.5 and PM2.5 Plan Precursors
    Under the CAA, states are required to regulate not only direct 
emissions of PM2.5 in an attainment plan, but also all 
PM2.5 precursors. Under the EPA's PM2.5 SIP 
Requirements Rule, states must identify, adopt, and implement control 
measures, including control technologies, on sources of direct 
PM2.5 emissions and sources of emissions of PM2.5 
plan precursors located in PM2.5 nonattainment areas.\107\ 
PM2.5 plan precursors are those PM2.5 precursors 
(which are sulfur dioxide (SO2), NOX, VOCs, and 
ammonia) that the state must regulate in the applicable attainment 
plan.\108\ A state may elect to submit to the EPA precursor 
demonstrations for a specific nonattainment area in order to establish 
that regulation of one or more precursors is not necessary for 
attainment in the nonattainment area at issue.\109\ If the EPA approves 
a comprehensive precursor demonstration that shows that emissions of a 
particular precursor does not contribute significantly to 
PM2.5 levels that exceed the NAAQS in an area, then the 
state is not required to control emissions of the relevant precursor 
from existing sources in the current attainment plan.\110\ Accordingly, 
the state would not need to address the precursor in order to meet 
attainment plan requirements, including RFP, in QMs and associated QM 
reports, or be required to adopt contingency measures to reduce the 
precursor at issue.\111\
---------------------------------------------------------------------------

    \107\ See generally 40 CFR 51.1009(a) and 40 CFR 51.1010(a).
    \108\ 40 CFR 51.1000.
    \109\ 40 CFR 51.1006(a).
    \110\ 40 CFR 51.1006(a)(1)(iii).
    \111\ 40 CFR 51.1009(a)(4)(i).
---------------------------------------------------------------------------

    For the San Joaquin Valley, as noted in section V.B.1 of this 
proposed rule, CARB and the District have concluded, based on CARB 
modeling, that SOX, VOCs, and ammonia are not significant 
precursors for PM2.5 formation in the San Joaquin 
Valley.\112\ The EPA has considered, and approved, the State's 
precursor demonstrations with respect to the 1997 annual, 2006 24-hour, 
and the 2012 annual PM2.5 NAAQS in taking action on the SIP 
submissions applicable to each NAAQS.\113\ Therefore, we agree with 
CARB and the District that the contingency measure submissions for the 
1997 annual, 2006 24-hour, and 2012 annual PM2.5 NAAQS must 
address sources of direct PM2.5 and NOX emissions 
but do not need to address sources of SOX, VOCs, or ammonia.
---------------------------------------------------------------------------

    \112\ See, e.g., SJV PM2.5 Contingency Measure SIP, 
Appendix G (Appendix C from the 2018 PM2.5 Plan), p. C-
12.
    \113\ EPA, ``Air Quality State Implementation Plans; Approvals 
and Promulgations: California; 1997 Annual Fine Particulate Matter 
Serious and Clean Air Act Section 189(d) Nonattainment Area 
Requirements; San Joaquin Valley, CA,'' Final rule, signed December 
5, 2023; 85 FR 17382, 17390-17396, finalized at 85 FR 44192; 86 FR 
49100, 49107-49112, finalized at 86 FR 67343.
---------------------------------------------------------------------------

    For the 2006 24-hour PM2.5 NAAQS, the EPA approved the 
comprehensive precursor demonstration that established that 
SO2, VOCs, and ammonia emissions do not contribute 
significantly to PM2.5 levels that exceed the 2006 24-hour 
PM2.5 NAAQS in the San Joaquin Valley.\114\ In 2020, a 
petition for review before the Ninth Circuit Court of Appeals 
challenged the EPA's approval of the portions of the 2019 SIP 
submissions related to the 2006 24-hour PM2.5 NAAQS. In 
2021, the Court vacated the approval of aggregate commitments to the 
extent such commitments relied on inadequately funded incentive-based 
control measures and remanded to the EPA for further consideration of 
the aggregate commitments, and for further proceedings consistent with 
the decision, but denied the petition in all other respects.\115\ The 
EPA's approval of the comprehensive precursor demonstration was not the 
subject of the court challenge. In light of the current circumstances 
surrounding these precursor demonstrations, the EPA agrees that direct 
PM2.5 and NOX are the appropriate pollutants for 
which contingency measures are required in the San Joaquin Valley for 
the 2006 24-hour PM2.5 NAAQS.
---------------------------------------------------------------------------

    \114\ 85 FR 17382, 17390-17396, finalized at 85 FR 44192.
    \115\ Medical Advocates for Healthy Air v. EPA, No. 20-72780, 
Memorandum, Dkt. #58-1 (9th Cir. Apr. 13, 2022).
---------------------------------------------------------------------------

b. Using Same Contingency Measures for More Than One Triggering Event, 
NAAQS
    Under CAA section 172(c)(9), SIPs must provide for the 
implementation of specific contingency measures if the area fails to 
meet RFP or to attain the NAAQS by the applicable attainment date. For 
PM2.5, there are four potential triggering events: failure 
to meet any RFP requirement, failure to submit a QM report, failure to 
meet a QM, and failure to attain the NAAQS by the applicable attainment 
date.\116\
---------------------------------------------------------------------------

    \116\ 40 CFR 51.1014(a).
---------------------------------------------------------------------------

    To meet the contingency measure requirement, states may adopt 
different measures for different triggering events but are not required 
to do so. If the state adopts the same set of contingency measures for 
all the triggering events, however, then the contingency measures may 
all be implemented by earlier-occurring triggering events leaving no 
contingency measures for potential later-occuring events. In that case, 
if a state has no remaining approved contingency measures, then the EPA 
believes that states must adopt and submit additional contingency 
measures to be available for potential later-occuring triggering 
events. The potential for states to have used all approved contingency 
measures, and thus to lack contingency measures for potential later-
triggering events is compounded by the reliance on the same set of 
contingency measures for more than one iteration of the 
PM2.5 NAAQS. Accordingly, while the EPA might approve a SIP 
that relies on the same contingency measures for multiple potential 
triggering events, a SIP that does so may be subject to the need for 
future revision each time a triggering event occurs.
    As noted previously, CARB and the District have submitted three 
contingency measures, each of which covers all three of the 1997 
annual, 2006 24-hour, and 2012 annual PM2.5 NAAQS (i.e., the 
same set of contingency measures has been submitted to address the 
contingency measure requirements for more than one PM2.5 
NAAQS). In addition, each of the contingency measures addresses each of 
the four potential triggering events: failure to meet any RFP 
requirement, failure to submit a QM report, failure to meet a QM, and 
failure to attain the NAAQS by the applicable attainment date.\117\ As 
noted previously, states may adopt different measures for different 
triggering events and different NAAQS, but we do not believe that 
states are

[[Page 88003]]

required to do so, and thus, we find that the State's reliance on the 
same set of contingency measures for more than one triggering event and 
more than one NAAQS to be acceptable.
---------------------------------------------------------------------------

    \117\ 40 CFR 51.1014(a).
---------------------------------------------------------------------------

    In this instance, two of the three contingency measures--the 
Residential Wood Burning Contingency Measure and the Smog Check 
Contingency Measure--include provisions that would separately be 
implemented after a second triggering event.\118\ Under section 5.7.3 
of Rule 4901, upon a first triggering event, the No Burn (i.e., 
curtailment) thresholds for the five non-hot spot counties (Kings, 
Merced, San Joaquin, Stanislaus, and Tulare) would be lowered to match 
the tighter No Burn thresholds for the three hot spot counties (Fresno, 
Madera, and Kern) (i.e., to 35 [mu]g/m\3\ for registered devices and to 
12 [mu]g/m\3\ for unregistered devices). Upon a subsequent triggering 
event (i.e., in response to a separate, later determination by the 
EPA), the No Burn threshold for unregistered fireplaces and woodstoves 
for all eight counties would be lowered from 12 [mu]g/m\3\ to 11 [mu]g/
m\3\.
---------------------------------------------------------------------------

    \118\ We note that the contingency provisions in Rule 8051 would 
be fully implemented following a first triggering event.
---------------------------------------------------------------------------

    Similarly, under the Smog Check Contingency Measure, upon a first 
triggering event, the Smog Check exemption would be lowered from eight 
or fewer model years old to seven or fewer model years old. Upon a 
subsequent triggering event (i.e., in response to a separate, later 
determination by the EPA), the Smog Check exemption would be lowered 
from seven or fewer model years old to six or fewer model years old.
    Therefore, after a first triggering event, the State would have two 
remaining SIP-approved contingency measures that are not yet triggered 
as it develops a SIP revision to meet the missed RFP requirement or to 
correct ongoing nonattainment. The EPA believes that the State would 
need to assess whether those two remaining contingency measures were 
sufficient to meet the contingency measure requirements in that future 
time and, if necessary, adopt and submit additional contingency 
measures to be available for potential later-occuring triggering 
events.
c. Magnitude of Emissions Reductions
    As noted previously, neither the CAA nor the EPA's implementing 
regulations establish a specific level of emission reductions that 
implementation of contingency measures must achieve, but the EPA has 
recommended in existing guidance that contingency measures should 
provide for emission reductions equivalent to approximately one year of 
reductions needed for RFP in the nonattainment area.
    Using the longstanding approach, contingency measures should 
provide for emissions reductions of approximately one year's worth of 
RFP for each of the relevant PM2.5 NAAQS. Under the approach 
described in the EPA's Draft Revised Contingency Measure Guidance, the 
EPA has suggested that contingency measures provide for emissions 
reductions of approximately one year's worth of progress for each of 
the relevant PM2.5 NAAQS rather than one year's worth of 
RFP.
    We have reviewed the calculations in the SJV PM2.5 
Contingency Measure SIP, as summarized in section V.B.1 of this 
proposed rule, and find that the State properly calculated one year's 
worth of RFP (as an interim step in calculating one year's worth of 
progress) and one year's worth of progress for each of the relevant 
PM2.5 NAAQS in the San Joaquin Valley.\119\ We have also 
reviewed the calculations in the SJV PM2.5 Contingency 
Measure SIP used to compare the emissions reductions from the 
Residential Wood Burning Contingency Measure with one year's worth of 
progress and generally find them to be acceptable with the exception 
that the calculation includes the emissions reductions from both 
triggering events in the evaluation. Only the emissions reductions from 
the first trigger should be used because there is no assurance that the 
additional emissions reductions from the second triggering event will 
provide emissions reductions in the year or two following the first 
triggering event.
---------------------------------------------------------------------------

    \119\ With respect to the 2012 PM2.5 NAAQS, we agree 
with the calculation of one year's worth of progress in the SJV 
PM2.5 Contingency Measure SIP that is based on the 
outermost RFP milestone year, rather than the attainment year, 
because, as an area for which an impracticability demonstration has 
been approved, the attainment year has not yet been established.
---------------------------------------------------------------------------

    We recognize that the calculations in the SJV PM2.5 
Contingency Measure SIP relied upon an interpollutant trading ratio of 
6:1 (i.e., 6 tpd NOX for each excess 1 tpd direct 
PM2.5) to convert ``excess'' PM2.5 emissions 
reductions to equivalent NOX emissions reductions. The 
technical basis of the interpollutant trading ratio of 6:1 was provided 
in the State's 2021 Progress Report to the EPA to support the State's 
Serious area attainment demonstration for the 2012 annual 
PM2.5 NAAQS. Specifically, the State analyzed the relative 
effect of reducing 30% direct PM2.5 (annual average) 
emissions versus 30% NOX (annual average) emissions on 
ambient annual average PM2.5 concentrations (as modeled for 
2024) at each regulatory monitoring site in the San Joaquin Valley 
using data from the precursor sensitivity analyses in the 2018 
PM2.5 Plan.\120\ While the 2021 Progress Report was 
nominally for only the 2012 annual PM2.5 NAAQS and 
corresponded to the modeled 2025 attainment year in the State's Serious 
area plan for the 2012 annual PM2.5 NAAQS (later withdrawn 
on October 27, 2022), we note that the control strategy in the 2018 
PM2.5 Plan was built upon annual average emissions 
inventories (e.g., for demonstrating RFP) and applied in common to the 
1997, 2006, and 2012 PM2.5 NAAQS. Later, the 15 [mu]g/m\3\ 
SIP Revision for the 1997 annual PM2.5 NAAQS retained the 
annual average emissions inventory basis for the control strategy to 
attain that NAAQS and continued to rely on the State's precursor 
sensitivity analyses. In other words, there is a common foundation on 
which CARB and the District selected the 6:1 ratio.
---------------------------------------------------------------------------

    \120\ See Appendix K (``Modeling Attainment Demonstration'') of 
the 2018 PM2.5 Plan, including Table 14 (annual average 
modeled emissions inventory) and Table 49 (precursor sensitivity 
analysis for annual average ambient PM2.5 concentration 
in 2024).
---------------------------------------------------------------------------

    As previously discussed, CARB and the District examined several 
methods for calculating the ratio based on varying combinations of 
monitoring sites. They concluded that 6:1 was a conservative ratio as 
it was less than the average ratio for the two sites (in Fresno and 
Kern Counties) with the highest modeled (annual average) ambient 
PM2.5 concentrations in 2025 (6.1:1), the average ratio of 
the six sites (in Fresno, Kern, Stanislaus, and Tulare Counties) with 
modeled 2025 concentrations over 11.00 [mu]g/m\3\ (6.4:1), and the 
average ratio of the six sites (in Fresno, Kern, Kings, and Tulare 
Counties) with a 2020 design value over 12 [mu]g/m\3\ (6.6:1).\121\
---------------------------------------------------------------------------

    \121\ 2021 Progress Report, Table 7 (``Base and Projected 2025 
Annual Average Design Values Used to Select/Prioritize Sites for 
Calculating an Average Trading Ratio''). At the time, the modeled 
2025 concentrations corresponded to the attainment year in the 
State's Serious area plan for the 2012 annual PM2.5 
NAAQS, which was later withdrawn on October 27, 2022.
---------------------------------------------------------------------------

    We have reviewed the State's technical basis for the 6:1 
interpollutant trading ratio and find that it is a reasonable ratio for 
purposes of estimating the NOX equivalent of excess direct 
PM2.5 emission reductions for purposes of contingency 
measures in the San Joaquin Valley for the 1997 annual, 2006 24-hour, 
and 2012 annual PM2.5 NAAQS. First, the annual average 
emissions inventory and integrated

[[Page 88004]]

nature of attainment planning for the three NAAQS provides a common 
emissions and control strategy basis for the ratios. Second, the ratios 
are based on whole emissions inventories (rather than, for example, 
only on-road emissions inventories that might be relevant to motor 
vehicle emission budgets) and modeling for a near-term year (2025), 
given that these contingency measures would be triggered no sooner than 
2024.
    Third, by examining several methods that involve averaging across 
two to six sites, including two methods that include both hot spot and 
non-hot spot counties, the State provides robustness in the ratio 
(i.e., may better reflect the effect of emission reductions from the 
three contingency measures across sites in the San Joaquin Valley). The 
inclusion of non-hot spot counties in two of the averaging methods is 
important in that, upon a first triggering event, the Residential Wood 
Burning Contingency Measure--which is the contingency measure that 
would achieve emission reductions in excess of one year's worth of 
direct PM2.5 emission reductions--would lower the No Burn 
(i.e., curtailment) thresholds for the five non-hot spot counties 
(Kings, Merced, San Joaquin, Stanislaus, and Tulare) to match the 
tighter No Burn thresholds for the three hot spot counties (Fresno, 
Madera, and Kern). Fourth, we agree with CARB and the District that the 
selected 6:1 ratio is conservative relative to the slightly higher 
average ratios of 6.1:1, 6.4:1, and 6.6:1 from the methods that select 
sites with relatively high modeled concentrations, and relative to the 
ratio of 8.1:1 at the modeled 2025 high site of Bakersfield-Planz.\122\
---------------------------------------------------------------------------

    \122\ We note that the interpollutant trading ratio of 6:1 
compares favorably with the interpollutant trading ratios that the 
EPA used recently in the Agency's proposed San Joaquin Valley 
PM2.5 contingency measure FIP. We provide our evaluation 
of the interpollutant trading ratio in the SJV PM2.5 
Contingency Measure SIP relative to the corresponding ratios in our 
proposed FIP in a Memorandum to File from Rory Mays and Scott 
Bohning, EPA Region IX, Subject: ``Comparison of California and EPA 
Interpollutant Trading Ratios for Trading Excess Direct 
PM2.5 Emission Reductions to NOX Equivalent 
Emission Reductions for PM2.5 Contingency Measure 
Purposes in the San Joaquin Valley,'' December 2023.
---------------------------------------------------------------------------

    The SJV PM2.5 Contingency Measure SIP calculated the 
emissions reductions only from the Residential Wood Burning Contingency 
Measure because that was the only adopted contingency measure at the 
time, but the District and CARB have since supplemented the submission 
with two additional contingency measures--the Rural Open Areas 
Contingency Measure and the Smog Check Contingency Measure. As 
described in sections IV.A and IV.B of this proposed rule, the EPA 
proposes to approve the Residential Wood Burning Continency Measure and 
the Rural Open Areas Contingency Measure and, in a separate rulemaking 
action, we are proposing to approve the Smog Check Contingency Measure. 
Table 2 summarizes the estimated emissions reductions from these 
contingency measures, as evaluated by the EPA.

          Table 2--Annual Average Emissions Reductions From District and CARB Contingency Measures, tpd
----------------------------------------------------------------------------------------------------------------
                                                  1997 Annual PM2.5    2006 24-hour PM2.5     2012 Annual PM2.5
                                                        NAAQS                 NAAQS                 NAAQS
              Contingency measure              -----------------------------------------------------------------
                                                  Direct                Direct                Direct
                                                  PM2.5       NOX       PM2.5       NOX       PM2.5       NOX
----------------------------------------------------------------------------------------------------------------
District: Residential Wood Burning (first          0.5793     0.0817     0.5793     0.0817     0.5793     0.0817
 triggering event)............................
District: Non-agricultural Rural Open Areas...      0.008  .........      0.008  .........      0.008  .........
CARB: Smog Check (first triggering event).....  .........      0.117  .........      0.120  .........      0.086
CARB: Effect of Moyer Program funding decrease  .........    (0.004)  .........    (0.004)  .........    (0.003)
 in the San Joaquin Valley if Smog Check
 Contingency Measure triggered................
                                               -----------------------------------------------------------------
    Total.....................................     0.5873     0.1947     0.5873     0.1977     0.5873     0.1647
----------------------------------------------------------------------------------------------------------------

    Table 3 presents the estimated emissions reductions as percentages 
of one year's worth of RFP and one year's worth of progress both with 
and without trading between direct PM2.5 and NOX 
emissions. As noted previously in this proposed rule, one year's worth 
of RFP is the longstanding recommendation by the EPA to states 
regarding the magnitude of emissions reductions that contingency 
measures should be capable of achieving. One year's worth of progress 
is the new recommendation described in the EPA's Draft Revised 
Contingency Measure Guidance. In addition, we are proposing to approve 
the State's trading ratio of 6:1 (i.e., 6 tpd NOX for each 
excess 1 tpd direct PM2.5) and to trade excess direct 
PM2.5 emission reductions, as evaluated by the EPA, to 
substitute for a portion of the shortfall in NOX emission 
reductions compared to one year's worth of RFP and one year's worth of 
progress.\123\ We apply this trading ratio in our calculations for all 
three PM2.5 NAAQS considered in this proposed rule.
---------------------------------------------------------------------------

    \123\ While this trading would not make up the entire shortfall 
in NOX emission reductions, it gives a sense for the 
magnitude of the relative ambient effect of the excess direct 
PM2.5 emission reductions towards meeting one year's 
worth of RFP or one year's worth of progress.

    Table 3--EPA Evaluation of District and CARB Contingency Measures as Percentage of One Year's Worth (OYW) of RFP and One Year's Worth of Progress
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                          One year's worth of RFP                    One year's worth of progress
                                                              ------------------------------------------------------------------------------------------
             PM2.5 NAAQS                     Pollutant          Reductions    % OYW  (no      % OYW  (with    Reductions    % OYW  (no     % OYW  (with
                                                                  target       trading)       trading) \a\      target       trading)      trading) \a\
--------------------------------------------------------------------------------------------------------------------------------------------------------
1997 Annual.........................  Direct PM2.5...........         0.44             132             100          0.41             142             100
                                      NOX....................         16.7             1.2             6.3           7.9             2.5            15.7
2006 24-hour........................  Direct PM2.5...........         0.58             101             100          0.52             112             100
                                      NOX....................         18.4             1.1             1.3           6.7             3.0             8.8
2012 Annual.........................  Direct PM2.5...........         0.46             129             100          0.43             138             100

[[Page 88005]]

 
                                      NOX....................         15.3             1.1             6.3           8.7             1.9            13.1
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The EPA has calculated % OYW (With Trading) for NOX based on the 6:1 ratio presented in the SJV PM2.5 Contingency Measure SIP.

    As shown in Table 2, the sum of the emissions reductions from the 
three contingency measures is approximately 0.5873 tpd direct 
PM2.5 and ranges from 0.1647 tpd to 0.1977 tpd 
NOX, depending on the particular PM2.5 NAAQS. 
Without taking into account the substitution principle, these 
reductions would exceed one year's worth of RFP for direct 
PM2.5 and provide a portion of one year's worth of RFP for 
NOX for the 1997 annual PM2.5 NAAQS, 2006 24-hour 
PM2.5 NAAQS, and the 2012 annual PM2.5 NAAQS, as 
shown in Table 3. With respect to one year's worth of progress, these 
reductions would similarly exceed one year's worth of progress for 
direct PM2.5 and provide a portion of one year's worth of 
progress for NOX for all three PM2.5 NAAQS, as 
shown in Table 3.
    Taking into account the substitution principle, under which, in 
this case, excess direct PM2.5 emissions are substituted for 
a shortfall in NOX emissions, the reductions would amount to 
100% of one year's worth of RFP for direct PM2.5 and the 
following amounts of one year's worth of RFP for NOX for 
each NAAQS: 1997 annual PM2.5 NAAQS (6.3%), 2006 24-hour 
PM2.5 NAAQS (1.3%), and 2012 annual PM2.5 NAAQS 
(6.3%). Similarly, the reductions would amount to 100% of one year's 
worth of progress for direct PM2.5 and the following amounts 
of one year's worth of progress for NOX for each NAAQS: 1997 
annual PM2.5 NAAQS (15.7%), 2006 24-hour PM2.5 
NAAQS (8.8%), and 2012 annual PM2.5 NAAQS (13.1%).
    While our estimates of the emissions from the contingency measures 
relative to one year's worth of RFP or progress differ in some respects 
from those contained in the SJV PM2.5 Contingency Measure 
SIP, our conclusion is the same as the conclusion drawn by the District 
and CARB, namely, that the emissions reductions would provide for one 
year's worth of RFP or progress for direct PM2.5 but would 
provide only a portion of one year's worth of RFP or progress for 
NOX. Thus, we would expect the State to provide a ``reasoned 
justification'' to support approval of the contingency measures as 
meeting the requirements under CAA section 172(c)(9) and 40 CFR 51.1014 
for the nonattainment area even though the contingency measures would 
not provide for the magnitude of emissions reductions recommended by 
the EPA to comply with the requirements. The District and CARB have 
included their reasoned justifications in the form of feasibility 
analyses included as chapters 4 and 5 of the SJV PM2.5 
Contingency Measure SIP, respectively. We provide our review of the 
feasibility analyses in the following section of this document.
2. Contingency Measure Feasibility Analyses
    The EPA has reviewed the State's infeasibility demonstrations for 
not adopting contingency measures beyond the residential wood burning, 
rural open areas, and Smog Check contingency measures, including both 
the process used by the State and its assessment specific to a wide 
range of stationary, area, and mobile source categories.\124\ Notably, 
in connection with the EPA's proposed contingency measure FIP for the 
San Joaquin Valley, the EPA recently prepared a detailed evaluation of 
source categories and measures that we considered as potential 
additional contingency measures but determined to be infeasible or 
otherwise unsuitable for contingency measures. See ``EPA Source 
Category and Control Measure Assessment and Reasoned Justification 
Technical Support Document, Proposed Contingency Measures Federal 
Implementation Plan for the Fine Particulate Matter Standards for San 
Joaquin Valley, California,'' July 2023 (``EPA's Reasoned Justification 
TSD''). We have relied heavily on that TSD given its breadth and depth, 
as well as the expertise of EPA Region IX staff, to review the State's 
infeasibility demonstration, understand where the State's and the EPA's 
analyses draw largely similar conclusions, and identify those source 
categories where the control measure analyses differ. As described in 
the following paragraphs, the EPA proposes to find that the State's 
infeasibility demonstrations adequately justify the contingency 
measures selected by the State to meet the contingency measure 
requirement under CAA section 172(c)(9) and 40 CFR 51.1014 for the San 
Joaquin Valley for the 1997 annual, 2006 24-hour, and 2012 annual 
PM2.5 NAAQS.
---------------------------------------------------------------------------

    \124\ Our summaries of the infeasibility demonstrations are 
found in section V.B.2 of this document.
---------------------------------------------------------------------------

    In terms of process, both CARB and the District identified and 
evaluated existing and potential control measures using components of 
the process recommended in the EPA's Draft Revised Contingency Measures 
Guidance,\125\ even if not necessarily in the same sequence as those 
recommended by the EPA. As described in section V.B.2 of this proposed 
rule, for the wide range of stationary and area sources under its 
jurisdiction, the District described their ongoing stationary source 
regulatory efforts, identified potential control measures as candidate 
contingency measures, and analyzed the technological and/or economic 
feasibility of each candidate measure, including the feasibility of 
implementing such measures within 60 days and achieving the resulting 
emission reductions within one to two years.\126\ The District also 
provided more in-depth analysis of potential control measures for five 
source categories, ultimately adopting measures for two source 
categories (wood burning fireplaces and wood burning heaters and rural 
open areas) and providing a reasoned justification for not adopting 
such measures for the other three source categories (commercial 
charbroiling, almond harvesting, and oil and gas production combustion 
equipment). We find that the District employed a reasonable process to 
identify and assess the feasibility and suitability of potential 
control measures as contingency measures for stationary and area 
sources in the San Joaquin Valley.
---------------------------------------------------------------------------

    \125\ EPA's Draft Contingency Measure Guidance, section 4 
(``Reasoned Justification for Less Than [One Year's Worth] of 
Progress'').
    \126\ SJV PM2.5 Contingency Measure SIP, pp. 9-11.
---------------------------------------------------------------------------

    Similarly, as described in section V.B.2 of this proposed rule, 
CARB identified potential mobile source control measures, assessed 
whether

[[Page 88006]]

each candidate measure could be implemented within 60 days of a 
triggering event and emission reductions achieved within one to two 
years, and then analyzed their technological and/or economic 
feasibility.\127\ Regarding timing of emission reductions from mobile 
sources, CARB concludes that new engine standards and fleet regulations 
are not appropriate for contingency measures given the time needed for 
manufacturers to design, develop, and deploy cleaner engines or 
equipment at scale, especially for zero-emission equipment.
---------------------------------------------------------------------------

    \127\ SJV PM2.5 Contingency Measure SIP, section 5.3 
(``Measure Analysis''); and Smog Check Contingency Measure, Appendix 
A (``Infeasibility Analysis'').
---------------------------------------------------------------------------

    As described in the EPA's Reasoned Justification TSD,\128\ as a 
general matter, new mobile source engine or vehicle emission standards 
require significant lead time (more than two years) to allow 
manufacturers time to retool factories to produce compliant engines or 
vehicles. Retrofit or replacement requirements also require significant 
lead time to allow owners and operators to manage the process of 
retrofitting or replacing old engines or vehicles. Therefore, we agree 
with CARB that such mobile source control measures would not achieve 
emission reductions within one to two years of a contingency measure 
triggering event. Overall, we find that the CARB employed a reasonable 
process to identify and assess the feasibility and suitability of 
potential control measures as contingency measures for mobile sources 
in the San Joaquin Valley and in California more broadly.\129\
---------------------------------------------------------------------------

    \128\ EPA's Reasoned Justification TSD, pp. 143-144.
    \129\ We note that the EPA's Reasoned Justification TSD contains 
additional information that presents a comprehensive summary of the 
emissions inventories for direct PM2.5 and NOX 
in the San Joaquin Valley, as well as consideration of past 
recommendations of new control measures or improvements to existing 
control measures by the EPA and community and environmental groups 
(whether for purposes of RACM/RACT, BACM/BACT, MSM, attainment and 
RFP demonstrations, or contingency measures).
---------------------------------------------------------------------------

    Beyond the analytical components employed by CARB and the District 
that mirror those recommended by the EPA, CARB and the District also 
evaluated whether they could develop, adopt, and secure EPA approval of 
SIP submissions, including additional contingency measures, meeting the 
contingency measure requirements, prior to the September 30, 2024 
consent decree deadline for the EPA to promulgate a contingency 
measures FIP for San Joaquin Valley for the 1997 annual, 2006 24-hour 
and 2012 PM2.5 NAAQS.\130\ The EPA finds that such 
considerations, while important in the broader context of environmental 
regulation and sanctions in the San Joaquin Valley, are not appropriate 
for evaluating the feasibility or suitability of potential control 
measures as contingency measures. Even absent final guidance from the 
EPA, states are required to adopt and submit contingency measures 
within the timelines established by the CAA in response to EPA actions, 
including disapproval of prior contingency measure submissions, as was 
the case here, effective December 27, 2021.\131\ In this instance, 
however, neither CARB nor the District relied upon the inability to 
adopt contingency measures and secure EPA approval by the consent 
decree deadline as the sole justification for not adopting additional 
contingency measures for any of the relevant source categories.
---------------------------------------------------------------------------

    \130\ SJV PM2.5 Contingency Measure SIP, pp. 12-25 
and pp. 57-58.
    \131\ 86 FR 67329 and 86 FR 67343.
---------------------------------------------------------------------------

    In addition, in certain instances, the District states that the 
robust public process necessary to develop and adopt control measures 
would take more than two years,\132\ while CARB states that a state-
wide regulatory measure typically needs five years to develop and 
adopt,\133\ and therefore fall outside the one to two-year timeframe 
recommended in the EPA's Draft Revised Contingency Measures Guidance. 
While we certainly appreciate the importance of robust public process 
in developing control measures, inclusive of public process 
requirements in the CAA and the Administrative Procedures Act, the EPA 
finds that such timing considerations are not appropriate for assessing 
the feasibility of potential control measures as contingency measures. 
As previously noted, states are required to adopt and submit 
contingency measures within the timelines established by the CAA in 
response to EPA actions, including disapproval of prior contingency 
measure submissions.
---------------------------------------------------------------------------

    \132\ SJV PM2.5 Contingency Measure SIP, section 4.2 
(``District Feasibility Analysis'').
    \133\ SJV PM2.5 Contingency Measure SIP, 57.
---------------------------------------------------------------------------

    For each of the stationary and area source categories examined, the 
EPA agrees with the District's determination that additional control 
measures cannot feasibly reduce emissions within one to two years. We 
first describe those source categories where we agree with the bases 
presented by the District. Then we discuss those source categories 
where the basis of the EPA's conclusion differs from that of the 
District, even while the conclusion itself is the same--that the 
additional control measure evaluated cannot feasibly reduce emissions 
within one to two years.
    The District's analyses and conclusions were substantially the same 
as those of the EPA for the following source categories: open burning 
and prescribed/hazard burning (Rules 4103 and 4106), cotton gins (Rule 
4204), fuel burning equipment (Rule 4301), flares (Rule 4311), lime 
kilns (Rule 4313; none operate in the San Joaquin Valley), solid fuel-
fired boilers, steam generators, and process heaters (Rule 4352), glass 
melting furnaces (Rule 4354), asphalt paving and maintenance (Rule 
4641; a VOC rule), internal combustion engines (Rule 4702), stationary 
gas turbines (Rule 4703), residential wood burning (Rule 4901, 
excluding the Residential Wood Burning Contingency Measure submitted as 
amendments to the rule), and fugitive dust (Regulation VIII, excluding 
the Rural Open Areas Contingency Measure submitted as amendments to 
Rule 8051).\134\
---------------------------------------------------------------------------

    \134\ We note that, in responding to comments received during 
the public review of the SJV PM2.5 Contingency Measure 
SIP and Residential Wood Burning Contingency Measure, the District 
states that, while there are limited opportunities for contingency 
measures, the District ``will consider additional wood burning 
curtailments as part of control measure analyses for upcoming 
[SIPs].'' SJV PM2.5 Contingency Measure SIP, Appendix J 
(``Comments and Responses''), p. J-4. See also EPA's Reasoned 
Justification TSD, section G.1 (``Residential Fuel Combustion'').
---------------------------------------------------------------------------

    We note that the candidate control measures evaluated for certain 
sources, such as internal combustion engines, stationary gas turbines, 
boilers, steam generators, and process heaters, would require 
installation of costly and engineering-intensive devices (e.g., oxy-
fuel fired furnaces and natural gas furnaces equipped with selective 
catalytic reduction (SCR) for glass melting). As described in the EPA's 
Reasoned Justification TSD, while these technologies may be available 
and feasible in some contexts, we found that it would be 
technologically infeasible for these measures to be implemented and 
achieve meaningful emission reductions within one to two years.\135\ 
Thus, we agree with the District's determinations that such measures 
would be technologically infeasible in the context of contingency 
measures at this time.
---------------------------------------------------------------------------

    \135\ See, e.g., EPA's Reasoned Justification TSD, pp. 9-22 (the 
EPA's evaluation of contingency measures for boilers, steam 
generators, and process heaters).
---------------------------------------------------------------------------

    We note that the EPA's Reasoned Justification TSD does not present 
an evaluation of potential contingency measures specifically related to 
District Rules 4301, 4309, and 4352 and, thus,

[[Page 88007]]

we provide our review and evaluation in this document. With respect to 
fuel burning equipment (Rule 4301), the SJV PM2.5 
Contingency Measure SIP notes that the District has adopted more 
stringent NOX requirements for specific types of fuel 
burning equipment that supersede Rule 4301.\136\ Potential contingency 
measures for emission sources related to Rule 4301 are covered in the 
EPA's evaluation of Rules 4306, 4307, 4308, 4309, 4320, and 4352. Our 
assessments of Rules 4309 and 4352 are contained in the following 
paragraphs.
---------------------------------------------------------------------------

    \136\ SJV PM2.5 Contingency Measure SIP, pp. 13-14.
---------------------------------------------------------------------------

    With respect to dryers, dehydrators, and ovens (related to Rule 
4309), the District considered controls such as low NOX 
burners and determined that such technology could not feasibly be 
implemented within the two-year timeframe for contingency measures for 
this category, includes further discussion in appendices F and G of the 
SJV PM2.5 Contingency Measure SIP (i.e., copies of the 
stationary and area source control evaluations for the 2022 Ozone Plan 
\137\ and the 2018 PM2.5 Plan, respectively), and states 
that, in certain applications (e.g., dehydrators for onions), may have 
an adverse effect on food product quality.\138\ We have reviewed the 
District's infeasibility demonstration and agree that emissions 
reductions for this category could not feasibly be achieved within one 
to two years, and are therefore not suitable for contingency measures. 
As discussed in Appendix F of the SJV PM2.5 Contingency 
Measure SIP, South Coast Air Quality Management District (AQMD) has 
recently revised and divided its rules for comparable sources, 
including amendments to NOX limits, that are difficult to 
compare to Rule 4309 given their distinct applicability and provisions 
(e.g., whether limits are differentiated by operating temperature). The 
EPA recommends that the District continue to evaluate dryers, 
dehydrators, and ovens for opportunities to further reduce 
NOX emissions (and, as applicable, PM2.5 
emissions) in developing subsequent plans.
---------------------------------------------------------------------------

    \137\ SJVUAPCD, ``2022 Plan for the 2015 8-hour Ozone 
Standard,'' adopted December 15, 2022.
    \138\ SJV PM2.5 Contingency Measure SIP, p. 16.
---------------------------------------------------------------------------

    With respect to Rule 4352, the State's submittal notes that the 
District adopted amendments to Rule 4352 in December 2021, and District 
analysis associated with the 2021 amendments to Rule 4352 found that 
all control alternatives that would further reduce emissions require 
technology that had prohibitively high capital costs and were not cost 
effective,\139\ and have not been widely implemented at facilities 
subject to Rule 4352. Given these reasons and given that the emission 
limits included in the 2021 amendments to Rule 4352 are lower than 
those of other districts' rules, we agree with the District's 
conclusion with respect to Rule 4352.
---------------------------------------------------------------------------

    \139\ SJVUAPCD, ``Appendix C, Cost Effectiveness Analysis for 
Proposed Amendments to Rule 4352 (Solid Fuel Fired Boilers, Steam 
Generators, and Process Heaters,'' December 16, 2021.
---------------------------------------------------------------------------

    For several other source categories, the EPA finds that the 
contingency measure analyses by the District and the EPA differ in 
certain respects that warrant further discussion. Notwithstanding these 
differences, both the District's analyses and the EPA's analyses 
supporting our recent contingency measure FIP proposal support the 
conclusion that the measures evaluated cannot feasibly reduce emissions 
within one to two years. We discuss each of these cases in the 
paragraphs that follow.
    With respect to residential water heaters (Rule 4902) and 
residential furnaces (Rule 4905), the District evaluated a contingency 
measure option to adopt electrification requirements (i.e., requiring 
newly purchased furnaces and water heaters to be zero-emission units) 
earlier than a commitment by CARB to develop a state-wide building 
electrification measure that would achieve emission reductions starting 
in 2030.\140\ The District deemed this contingency measure option 
infeasible, citing the lead time necessary for manufacturers to design 
and produce electric units, the need for collaboration with energy and 
building code regulators, consistency with State and local efforts, 
consideration of housing cost and affordability impacts, and equity 
considerations for low-income and environmental justice 
communities.\141\ While we note that certain aspects of these factors 
do not necessarily align with the feasibility criteria outlined in the 
EPA's Draft Revised Contingency Measures Guidance,\142\ the EPA 
determined that the building electrification contingency measure option 
would not be feasible because we expect that it would result in 
negligible emissions reductions within two years after trigger,\143\ 
consistent with the District's suggestion that the attrition-based 
nature of implementation of this contingency measure option deem the 
measure infeasible. The EPA also recommended that the District consider 
developing control measures or programs that would incentivize the 
early replacement of existing gas space and water heaters with electric 
appliances, as such actions could significantly reduce emissions from 
this significant source category in the longer-term future.
---------------------------------------------------------------------------

    \140\ SJV PM2.5 Contingency Measure SIP, 20-22.
    \141\ For further discussion of these factors, see CARB, ``2022 
State Strategy for the State Implementation Plan,'' adopted 
September 22, 2022, pp. 101-103 (``Proposed Measures: Residential 
and Commercial Buildings'').
    \142\ EPA's Draft Revised Contingency Measures Guidance, pp. 35-
38.
    \143\ EPA's Reasoned Justification TSD, pp. 43-51.
---------------------------------------------------------------------------

    With respect to commercial charbroiling (Rule 4692), the District 
noted that particulate matter control devices are required to be 
installed and operated on chain-driven commercial charbroilers under 
Rule 4692. The District evaluated a contingency measure option 
involving the requirement of particulate matter controls on underfired 
charbroilers. The District's evaluation includes a detailed cost 
analysis, concluding that underfired charbroiler contingency measure 
option is infeasible based on high costs of installation and 
maintenance, technological infeasibility considerations, lack of 
availability of specialized staff at restaurants, control equipment 
fire safety certification concerns, and the lack of demonstrated 
controls in areas that have adopted underfired charbroiling control 
measures.\144\ The District also described ongoing and upcoming efforts 
to advance underfired charbroiler emissions control technology and 
demonstrate its performance in practice. The EPA's evaluation did not 
present cost information to conclude that an underfired charbroiling 
contingency measure would be economically infeasible, and we did not 
include the same considerations regarding lack of availability of 
specialized staff at restaurants and other technological feasibility 
concerns presented by the District. However, the EPA determined that an 
underfired charbroiling contingency measure would be infeasible based 
on fire safety certification concerns and lack of demonstrated 
implementation of controls.\145\ In addition to recommending that the 
District and CARB collaborate with control technology manufacturers and 
industry to develop effective methods for reducing the commercial 
cooking industry's impact on public health, the EPA strongly encouraged 
the District to expand its Restaurant Charbroiler

[[Page 88008]]

Technology Partnership program beyond hot spot counties.
---------------------------------------------------------------------------

    \144\ SJV PM2.5 Contingency Measure SIP, pp. 32-41.
    \145\ EPA's Reasoned Justification TSD, pp. 131-136.
---------------------------------------------------------------------------

    With respect to conservation management practices (Rule 4550), the 
District describes its commitment in the 2018 PM2.5 Plan to 
evaluate emission reduction opportunities for sources in this category 
(e.g., emission reductions from fallowed lands and promotion of 
selection of conservation tillage as a conservation management practice 
[CMP]), explaining that rule development is ongoing and describing Rule 
4550 as an ``on-the-way'' measure.\146\ We acknowledge the ongoing 
efforts by the District to pursue emission reductions from these 
sources,\147\ although we note that the District's use of the ``on-the-
way'' term differs from its usage in the Draft Revised Contingency 
Measures Guidance, where the EPA defines ``on-the-way'' measures as 
``the control measures in the nonattainment plan that will be 
implemented during the upcoming planning period'' (i.e., adopted 
measures whose implementation is forthcoming in the near-term).\148\ 
However, the EPA conducted its own evaluation of Rule 4550, finding 
that Rule 4550 contains conservation management practice options that 
are comparable with the rules identified in other jurisdictions and 
generally contain the same control measures required in other 
jurisdictions.\149\
---------------------------------------------------------------------------

    \146\ SJV PM2.5 Contingency Measure SIP, pp. 23-24.
    \147\ See, e.g., SJVUAPCD, ``Public Workshop for Potential 
Amendments to District Rule 4550 (Conservation Management 
Practices),'' November 7, 2022 (workshop presentation).
    \148\ EPA's Draft Revised Contingency Measure Guidance, p. 32.
    \149\ EPA's Reasoned Justification TSD, pp. 86-90.
---------------------------------------------------------------------------

    The District also presented an evaluation of dust emissions from 
almond harvesting, concluding that a contingency measure requiring the 
replacement of conventional harvesting technology with low dust 
harvesting technology would be infeasible based on long lead times 
needed to meet significant increased demand generated by such a 
measure, prohibitively high cost of equipment, and the need to conduct 
additional research to better understand the changing landscape in 
harvesting techniques and associated emissions.\150\ The EPA's 
evaluation determined that such a measure would be infeasible based 
only on the timing of emissions reductions; while the EPA presented 
cost effectiveness information for low dust almond harvesters,\151\ the 
EPA did not determine that a low dust harvester replacement contingency 
measure would be economically infeasible, nor did we determine that any 
work needed to understand the emissions profile of low dust nut 
harvesters would disqualify a potential low dust harvester replacement 
contingency measure.\152\
---------------------------------------------------------------------------

    \150\ SJV PM2.5 Contingency Measure SIP, pp. 41-43.
    \151\ EPA's Reasoned Justification TSD, chapter V.
    \152\ EPA's Reasoned Justification TSD, p. 95.
---------------------------------------------------------------------------

    With respect to oil and gas production combustion equipment 
(related to District Rules 4306 and 4320), the District evaluated 
numerous control options including direct control of PM2.5 
(e.g., electrostatic precipitators or venturi scrubbers), 
electrification of oilfield steam generators, and solar powered 
oilfield steam generators.\153\ For each of these options, the District 
provided technological and/or economic feasibility considerations 
deeming each option infeasible as a contingency measure. The District 
also evaluated lower emission limits for boilers and steam 
generators.\154\ In this evaluation, the District explained that the 
EPA has determined that Rule 4306 meets MSM requirements and that Rule 
4320 goes beyond MSM by establishing even lower emissions limits. The 
District noted that equipment operators are already in the process of 
investing in and installing technology to meet the recently amended 
Rule 4320 limits and suggests that the time needed to plan and prepare 
for installation of control equipment to meet lower limits would exceed 
the one- to two-year timeline for a contingency measure to achieve 
emissions reductions. The District also claims numerous technological 
feasibility considerations associated with lowering emission limits for 
this category. While the District describes a ``lack of EPA recognized 
SIP-creditable emissions reductions from Rule 4320'' due to the 
technology advancing nature of Rule 4320,\155\ the EPA would recognize 
SIP-creditable emission reductions for this category if provided with 
the appropriate information such as records of the number of units 
complying with Rule 4320 NOX emission limits and their 
associated emissions.\156\
---------------------------------------------------------------------------

    \153\ SJV PM2.5 Contingency Measure SIP, pp. 44-47.
    \154\ SJV PM2.5 Contingency Measure SIP, pp. 47-49.
    \155\ SJV PM2.5 Contingency Measure SIP, p. 49.
    \156\ See also, EPA Region IX, ``Technical Support Document for 
EPA's Notice of Proposed Rulemaking for the California State 
Implementation Plan, San Joaquin Valley Unified Air Pollution 
Control District's Rule 4320, Advanced Emission Reduction Options 
for Boilers, Steam Generators, and Process Heaters Greater than 5.0 
MMBtu/hr),'' August 19, 2010, p. 8.
---------------------------------------------------------------------------

    The EPA's evaluation focused on lowering emission limits for 
boilers and steam generators, including identification of lower 
emission limits adopted by the South Coast AQMD for oilfield steam 
generators than those adopted in Rule 4306. While the EPA's evaluation 
does not claim that control requirements required to meet the lower 
limits would be technologically infeasible altogether (in light of the 
lower limits adopted by South Coast AQMD), we determined that it would 
be technologically infeasible to meet the lower limits within the two-
year timeframe for contingency measures due to the likely requirement 
that affected units would need to install SCR to meet the lower limits.
    The District also included evaluations for boilers, steam 
generators, and process heaters in general covered by District Rules 
4307 and 4308.\157\ The District's assessments for these rules focus on 
economic and technological feasibility, citing dollar per ton cost 
effectiveness values for numerous control options and adding 
technological feasibility concerns for SCONOx/EMx units. The EPA's 
evaluation for boilers in general does not provide cost effectiveness 
values to suggest that lower emission limits for boilers, steam 
generators, and process heaters are economically infeasible. However, 
as described in the EPA's evaluation, we expect that units required to 
meet lower limits than those already adopted in Rules 4307 and 4308 
would require installation of SCR, which cannot be feasibly achieved 
within the two-year timeframe for contingency measures.\158\
---------------------------------------------------------------------------

    \157\ SJV PM2.5 Contingency Measure SIP, pp. 14-16.
    \158\ EPA's Reasoned Justification TSD, pp. 9-22.
---------------------------------------------------------------------------

    Similar to our evaluation of the District's feasibility analysis, 
we have evaluated CARB's feasibility analysis, in part, by comparing 
the bases and conclusions of the State's analysis against those 
presented in the EPA's Reasoned Justification TSD.\159\ Both CARB and 
the EPA note the importance of mobile source emissions in the San 
Joaquin Valley, particularly given that the large majority of 
NOX emissions are from mobile sources, and describe the 
breadth of control measures considered by CARB to reduce direct 
PM2.5 and NOX emissions for broader CAA purposes 
in the San Joaquin Valley. These include new vehicle and engine 
emission standards, for both on-road and non-road applications, which 
generally apply to manufacturers and

[[Page 88009]]

achieve emission reductions through vehicle turnover; retrofit or 
replacement requirements for existing vehicles and fleets; and 
inspection and maintenance (I/M) program requirements, such as those 
implemented under California's Smog Check program for light-duty 
passenger cars and trucks, and those entering implementation under 
California's Heavy-Duty I/M program. We agree that the adopted measures 
and on-going development of mobile sources measures by CARB, including 
zero-emission standards, further constrain the opportunities for 
additional emission reductions via contingency measures.\160\
---------------------------------------------------------------------------

    \159\ EPA's Reasoned Justification TSD, section H (``Mobile 
Sources'').
    \160\ EPA's Reasoned Justification TSD, pp. 139-142. See also, 
SJV PM2.5 Contingency Measure SIP, pp. 53-56; and Smog 
Check Contingency Measure, pp. 8-10.
---------------------------------------------------------------------------

    With respect to contingency measure requirements, CARB examined 
potential controls across the wide range of mobile source categories, 
including on-road light-duty passenger cars, trucks, and motorcycles; 
medium- and heavy-duty trucks and buses and transportation 
refrigeration units; commercial harbor craft, recreational boats, and 
ocean going vessels; off-road industrial, construction, and mining 
equipment; airport ground equipment, port and rail operations, and 
locomotives; lawn and garden equipment; and space and water heaters. 
The potential controls considered include pulling forward compliance 
dates and/or phase-in requirements; setting more stringent standards 
(often atop recently tightened standards) through mechanisms such as 
emission standards, emissions caps, thresholds for compliance, testing 
frequency, making optional standards required, or percentage of sales 
requirements; and removing exemptions and/or compliance options. In 
virtually all cases, CARB found that control measures beyond those 
already adopted or in development to fulfill commitments (e.g., under 
the 2022 State SIP Strategy) were not technologically feasible.\161\ In 
all cases (except the adopted Smog Check Contingency Measure), CARB 
found that the measures were not suitable for contingency measures due 
to lead time to develop, certify, adopt, and/or implement measures that 
could not be implemented within 60 days of a triggering event and 
achieve emission reductions within one year of the triggering event.
---------------------------------------------------------------------------

    \161\ There were three measures that CARB indicated as 
technologically feasible. One is the Smog Check Contingency Measure 
that CARB has adopted and submitted to the EPA. A second was a 
different Smog Check measure that would add requirements for only 
high mileage vehicles; however, CARB found that the compliance 
burden would disproportionately fall on low-income populations and 
disadvantaged communities. SJV PM2.5 Contingency Measures 
SIP, p. 59. The third was to increase the testing frequency under 
the Heavy-Duty I/M program; however, CARB found that the compliance 
burden would disproportionately fall on small businesses and low-
income populations. SJV PM2.5 Contingency Measure SIP, p. 
62 and Appendix A, p. 49. In the latter two cases, CARB also found 
that, even if the measure were technologically feasible, the 
measures could not be effectuated within the timeframe necessary for 
contingency measures.
---------------------------------------------------------------------------

    We have reviewed CARB's specific control measure analyses and agree 
that such potential control measures are not feasible within the 
timeframe necessary for contingency measures and, in many cases, are 
not technologically feasible to the extent that they build upon on-the-
books and on-the-way measures that are technology- or market-forcing. 
Consistent with our evaluation presented in the EPA's Reasoned 
Justification TSD,\162\ the EPA has not identified any engine or 
vehicle emission standards for consideration as contingency measures. 
Beyond the wide range of source types and control approaches examined 
by CARB, the EPA also examined a handful of potential additional 
controls and concluded that they too were not suitable as contingency 
measures, including expansion of Enhanced I/M requirements to areas 
currently subject to Basic I/M or Partial Enhanced I/M requirements in 
the San Joaquin Valley,\163\ provisions to expand the applicability of 
and add requirements to District Rule 9510 (``Indirect Source 
Review''),\164\ and additional transportation control measures.\165\ 
Therefore, we propose to find that CARB's infeasibility demonstration 
adequately justifies the contingency measures selected by CARB for the 
San Joaquin Valley for the 1997 annual, 2006 24-hour and 2012 annual 
PM2.5 NAAQS.
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    \162\ EPA's Reasoned Justification TSD, pp. 138-144.
    \163\ EPA's Reasoned Justification TSD, section IV.E. In 
addition, CARB noted in its comment letter on the EPA's proposed 
contingency measure FIP that, under the I/M measure evaluated by the 
EPA, 50% of the vehicles that would be newly subject to Enhanced I/M 
would be in disadvantaged communities whereas only 35% of San 
Joaquin Valley population live in such disadvantaged communities. 
Letter dated September 22, 2023, from Steven S. Cliff, Ph.D., 
Executive Officer, CARB to Martha Guzman, Regional Administrator, 
EPA Region IX. In other words, the compliance burden would 
disproportionately fall on low-income populations and disadvantaged 
communities.
    \164\ EPA's Reasoned Justification TSD, section IV.B.
    \165\ EPA's Reasoned Justification TSD, pp. 144-146.
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3. Conclusion
    Based on our review and proposed approval of the three contingency 
measures submitted by the State that would achieve the full one year's 
worth of emission reductions for direct PM2.5 and a portion 
of one year's worth of emission reductions for NOX (whether 
using the longstanding RFP method or the new progress method) and our 
review of and proposed finding that the State's infeasibility 
demonstrations adequately justify the selection of the three 
contingency measures, we propose to approve the SJV PM2.5 
Contingency Measures SIP, the Residential Wood Burning Contingency 
Measure, the Rural Open Areas Contingency Measure, and the Smog Check 
Contingency Measure (as applied to the San Joaquin Valley) as meeting 
the contingency measure requirements of CAA section 172(c)(9) and 40 
CFR 51.1014 for the 1997 annual, 2006 24-hour, and 2012 annual 
PM2.5 NAAQS in the San Joaquin Valley.

VI. Environmental Justice Considerations

    Executive Order 12898 (59 FR 7629, February 16, 1994) requires that 
federal agencies, to the greatest extent practicable and permitted by 
law, identify and address disproportionately high and adverse human 
health or environmental effects of their actions on minority and low-
income populations.\166\ To identify environmental burdens and 
susceptible populations in underserved communities in the San Joaquin 
Valley nonattainment area and to better understand the context of our 
proposed action on these communities, we conducted a screening-level 
analysis for PM2.5 in the San Joaquin Valley using the EPA's 
environmental justice (EJ) screening and mapping tool 
(``EJSCREEN'').\167\ The results of this analysis are being provided 
for informational and transparency purposes.
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    \166\ 59 FR 7629 (February 16, 1994).
    \167\ EJSCREEN provides a nationally consistent dataset and 
approach for combining environmental and demographic indicators. 
EJSCREEN is available at https://www.epa.gov/ejscreen/what-ejscreen. 
The EPA used EJSCREEN to obtain environmental and demographic 
indicators representing each of the eight counties in the San 
Joaquin Valley. We note that the indicators for Kern County are for 
the entire county. While the indicators might have slightly 
different numbers for the San Joaquin Valley portion of the county, 
most of the county's population is in the San Joaquin Valley 
portion, and thus the differences would be small. These indicators 
are included in EJSCREEN reports that are available in the 
rulemaking docket for this action.
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    Our screening-level analysis indicates that all eight counties in 
the San Joaquin

[[Page 88010]]

Valley score above the national average for the EJSCREEN ``Demographic 
Index'' (i.e., ranging from 48% in Stanislaus County to 61% in Tulare 
County, compared to 36% nationally).168 169 The Demographic 
Index is the average of an area's percent minority and percent low 
income populations, i.e., the two populations explicitly named in 
Executive Order 12898.\170\ All eight counties also score above the 
national average for demographic indices of ``linguistically isolated 
population'' and ``population with less than high school education.''
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    \168\ EPA Region IX, ``EJSCREEN Analysis for the Eight Counties 
of the San Joaquin Valley Nonattainment Area,'' August 2022.
    \169\ By comparison, the eight counties score above the State 
average for the EJSCREEN ``Demographic Index'' (i.e., ranging from 
52% in Stanislaus County to 71% in Tulare County, compared to 47% in 
California).
    \170\ EJSCREEN reports environmental indicators (e.g., air 
toxics cancer risk, Pb paint exposure, and traffic proximity and 
volume) and demographic indicators (e.g., people of color, low 
income, and linguistically isolated populations). The score for a 
particular indicator measures how the community of interest compares 
with the state, the EPA region, or the national average. For 
example, if a given location is at the 95th percentile nationwide, 
this means that only five percent of the U.S. population has a 
higher value than the average person in the location being analyzed. 
EJSCREEN also reports EJ indexes, which are combinations of a single 
environmental indicator with the EJSCREEN Demographic Index. For 
additional information about environmental and demographic 
indicators and EJ indexes reported by EJSCREEN, see EPA, ``EJSCREEN 
Environmental Justice Mapping and Screening Tool--EJSCREEN Technical 
Documentation,'' section 2 (September 2019).
---------------------------------------------------------------------------

    With respect to pollution, all eight counties (Fresno, Kern, Kings, 
Madera, Merced, San Joaquin, Stanislaus, and Tulare) score at or above 
the 97th percentile nationally for the PM2.5 index and seven 
of the eight counties in the San Joaquin Valley score at or above the 
90th percentile nationally for the PM2.5 EJ index (i.e., 
each county except Stanislaus County, which scores at the 87th 
percentile nationally), which is a combination of the Demographic Index 
and the PM2.5 index.\171\ Most counties also scored above 
the 80th percentile for each of 11 additional EJ indices included in 
the EPA's EJSCREEN analysis. In addition, several counties scored above 
the 90th percentile for certain EJ indices, including, for example, the 
Ozone EJ Index (Fresno, Kern, Madera, Merced, and Tulare Counties), the 
National Air Toxics Assessment (NATA) Respiratory Hazard EJ Index 
(Madera and Tulare Counties), and the Wastewater Discharge Indicator EJ 
Index (Merced, San Joaquin, Stanislaus, and Tulare Counties).\172\
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    \171\ By comparison, two counties score at or above the 97th 
percentile in California for the PM2.5 index and five 
counties score at or above the 80th percentile in California for the 
PM2.5 EJ index (rather than seven of eight counties that 
score at or above the 90th percentile nationally).
    \172\ Notably, Tulare County scores above the 90th percentile on 
six of the 12 EJ indices in the EPA's EJSCREEN analysis, including 
the PM2.5 EJ Index, which is the highest count among all 
San Joaquin Valley counties.
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    We have considered the geographic scope of each of the contingency 
measures that the EPA proposes to approve herein on PM2.5 
concentrations in each county of the San Joaquin Valley, as well as 
other environmental considerations that pertain to applicable pollutant 
(i.e., combustion PM2.5, dust PM2.5, or 
NOX) and the applicable source category or categories.
    For residential wood burning, upon a first triggering event, the 
Rule 4901 contingency measure would lower the No Burn (i.e., 
curtailment) thresholds for the five non-hot spot counties (Kings, 
Merced, San Joaquin, Stanislaus, and Tulare) to match the tighter No 
Burn thresholds for the three hot spot counties (Fresno, Madera, and 
Kern). A prominent effect of this change would be to provide similar 
protections to people in the two southern-most non-hot spot counties 
that record among the highest year-to-year PM2.5 design 
values in the San Joaquin Valley (i.e., Kings County, including 
Corcoran and Hanford monitoring sites, and Tulare County, including 
Visalia monitoring site).\173\ Were No Burn days to be called in Kings 
or Tulare County according to the more stringent thresholds, we also 
anticipate there would be smaller but still beneficial effect in the 
adjacent Fresno or Kern Counties, depending on the meteorology of the 
day. Upon a second triggering event, the Rule 4901 contingency measure 
would further lower the curtailment threshold for unregistered devices 
in all eight counties of the San Joaquin Valley. This would provide 
further protections to people throughout the area, including both hot-
spot and non-hot spot counties, including those that record among the 
highest year-to-year PM2.5 design values in the San Joaquin 
Valley.\174\
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    \173\ For example, the certified 2020-2022 PM2.5 
design value for Visalia (AQS Site ID 061072003) is 18.4 [mu]g/m\3\ 
for the 2012 annual PM2.5 NAAQS and 65 [mu]g/m\3\ for the 
2006 24-hour PM2.5 NAAQS. EPA design value workbook dated 
May 23, 2023, ``PM25_DesignValues_2020_2022_FINAL_05_23_23.xlsx,'' 
worksheets ``Table5a. Site Status Ann'' and ``Table5b.Site Status 
24hr.'' The certified design value includes all available data; no 
data flagged for exceptional events have been excluded. The EPA's 
Air Quality System (AQS) contains ambient air pollution data 
collected by federal, state, local, and tribal air pollution control 
agencies from thousands of monitors. More information is available 
at https://www.epa.gov/aqs.
    \174\ For example, the certified 2020-2022 PM2.5 
design value for Bakersfield-Airport (Planz) (AQS Site ID 060290016) 
is 18.8 [mu]g/m\3\ for the 2012 annual PM2.5 NAAQS and 61 
[mu]g/m\3\ for the 2006 24-hour PM2.5 NAAQS. EPA design 
value workbook dated May 23, 2023, 
``PM25_DesignValues_2020_2022_FINAL_05_23_23.xlsx,'' worksheets 
``Table5a. Site Status Ann'' and ``Table5b.Site Status 24hr.'' The 
certified design value includes all available data; no data flagged 
for exceptional events have been excluded.
---------------------------------------------------------------------------

    Where these direct PM2.5 emission reductions from 
combustion occur, we also note that they do not require further 
chemical transformation in the atmosphere to form PM2.5 
(i.e., the benefit is immediate) and, as they include fine particulate 
matter under one micron and toxic air chemicals, the reduction of such 
sub-micron particles would similarly reduce exposure of all residents 
in these areas, including minority and low-income populations to these 
environmental stressors. These reductions would also specifically 
reduce emissions on the winter days with the highest ambient 
PM2.5 levels.
    For open areas, the Rule 8051 contingency measure, if triggered, 
would lower the applicability threshold for the rural open area 
requirements of Rule 8051 (i.e., for parcels having at least 1,000 
square feet of disturbed soil) from 3.0 acres to 1.0 acre. Based on our 
analysis of land use to date, such rural open areas are found in all 
counties of the San Joaquin Valley, though with some variation from 
county to county consistent with overall land use types (e.g., San 
Joaquin County has the smallest proportion of rural open areas, while 
Madera County has the highest proportion of rural open areas). 
Furthermore, there is variation in the number of rural open areas that 
would be newly subject to the rule, i.e., those between 1.0 to 3.0 
acres in size (e.g., Kern County has the most total rural open area 
acreage from parcels between 1.0 to 3.0 acres in size, while Tulare 
County has the least). Given the overall land use and emission 
factors,\175\ and assuming roughly equal levels of activity in each 
county (i.e., soil disturbances over 1,000 square feet), we anticipate 
that the proposed contingency measure would provide air quality 
benefits in all counties of the San Joaquin Valley, with most air 
quality benefits occuring in Fresno, Kern, Kings, and Madera Counties.
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    \175\ For further discussion of the land use and emission 
factors for open areas in the San Joaquin Valley, see EPA Region IX, 
``Technical Support Document, Proposed Contingency Measures Federal 
Implementation Plan for the Fine Particulate Matter Standards for 
San Joaquin Valley, California,'' July 2023, section III.E.
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    Given that Rule 8051 for open areas was originally introduced as a 
PM10 control measure, we anticipate that the proposed 
measure would provide co-benefits to limiting PM10 levels in 
the San Joaquin Valley, with the same

[[Page 88011]]

geographical distribution as discussed herein for direct 
PM2.5 emission reductions.\176\
---------------------------------------------------------------------------

    \176\ We also note that environmental and community groups have 
recommended that fugitive dust sources in the San Joaquin Valley be 
subject to specific requirements rather than having the option to 
select from a menu of control requirements in Rule 8011 (where the 
definition for open areas is found). Letter dated May 18, 2022, from 
Tom Frantz, Association of Irritated Residents, et al., to Michael 
S. Regan, EPA Administrator, Attachment B, 7. The proposed measure 
would not alter the existing structure but rather tighten the 
applicability threshold for rural open areas.
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    Lastly, we anticipate that the Smog Check Contingency Measure 
(discussed in more detail in our separate proposed rule),\177\ if 
triggered, would reduce NOX and VOC emissions from light-
duty vehicles throughout the San Joaquin Valley. Such emission 
reductions would provide air quality benefits in all counties of the 
San Joaquin Valley and especially along roadways with the highest 
vehicle miles traveled, including the major freeways (e.g., California 
Highway 99) and urban areas (e.g., Bakersfield, Fresno, Stockton, 
Visalia) that intersect minority populations and low-income populations 
throughout the San Joaquin Valley.
---------------------------------------------------------------------------

    \177\ EPA, ``Air Plan Revision; California; Motor Vehicle 
Inspection and Maintenance Program Contingency Measure,'' Proposed 
rule, published in this Federal Register.
---------------------------------------------------------------------------

VII. Proposed Action and Request for Public Comment

    For the reasons described in sections IV and V of this document, 
and under CAA section 110(k)(3), the EPA proposes to approve two SIP 
revisions submitted by CARB on June 8, 2023, and October 16, 2023, for 
the San Joaquin Valley to address the contingency measure SIP 
requirements for San Joaquin Valley for the 1997 annual, 2006 24-hour, 
and 2012 annual PM2.5 NAAQS. The SIP submissions include the 
contingency measure plan element for San Joaquin Valley for the 
relevant PM2.5 NAAQS (referred to herein as the ``SJV 
PM2.5 Contingency Measure SIP'') and two specific 
contingency measures, referred to herein as the Residential Wood 
Burning Contingency Measure and the Rural Open Areas Contingency 
Measure. We are proposing to approve the SJV PM2.5 
Contingency Measure SIP as meeting the applicable requirements of CAA 
section 172(c)(9) and 40 CFR 51.1014 for San Joaquin Valley for the 
applicable PM2.5 NAAQS based on the infeasibility 
demonstrations that are provided in the submission and based on our 
proposed approval of the contingency measures. The Residential Wood 
Burning Contingency Measure and the Rural Open Areas Contingency 
Measure are included in amendments to SJVUAPCD Rule 4901 (``Wood 
Burning Fireplaces and Wood Burning Heaters'') and Rule 8051 (``Open 
Areas''), respectively. We are proposing to approve the two specific 
contingency measures because they meet the requirements under CAA 
section 172(c)(9) and 40 CFR 51.1014 for such measures. We will accept 
comments from the public on this proposal until January 19, 2024.
    If we finalize this action as proposed, our action will resolve the 
disapproval of the contingency measure plan elements for San Joaquin 
Valley for the 1997 annual, 2006 24-hour, and 2012 annual 
PM2.5 NAAQS, and our action will be codified through 
revisions to 40 CFR 52.220, ``Identification of plan--in part'' and 40 
CFR 52.237, ``Part D Disapproval.'' In conjunction with our final 
approval into the SIP of the submitted amended versions of SJVUAPCD 
Rules 4901 and 8051, we would remove from the SIP the previously 
approved versions of SJVUAPCD Rules 4901 and 8051. Lastly, if we 
finalize our action as proposed, our FIP obligation arising from our 
December 6, 2018 finding of failure to submit will be terminated, and 
thus, we will no longer be obligated to finalize our August 8, 2023 
proposed contingency measure FIP for San Joaquin Valley.

VIII. Incorporation by Reference

    In this rulemaking, the EPA is proposing to include in a final EPA 
rule regulatory text that includes incorporation by reference. In 
accordance with requirements of 1 CFR 51.5, the EPA is proposing to 
incorporate by reference SJVUAPCD Rule 4901 (``Wood Burning Fireplaces 
and Wood Burning Heaters''), amended May 18, 2023, and Rule 8051 
(``Open Areas''), amended September 21, 2023, identified and discussed 
in sections IV.A and IV.B of this preamble and that include revisions 
to meet the contingency measure requirements under part D of title I of 
the CAA. The EPA has made, and will continue to make, these materials 
available through https://www.regulations.gov and at the EPA Region IX 
Office (please contact the person identified in the FOR FURTHER 
INFORMATION CONTACT section of this preamble for more information).

IX. 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 and related measures as meeting Federal requirements and does not 
impose additional requirements beyond those imposed by state law. For 
that reason, this proposed action:
     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 14094 (88 FR 21879, April 11, 2023);
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     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.);
     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);
     Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not subject to Executive Order 13045 (62 FR 19885, 
April 23, 1997) because it proposes to approve a state program;
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001); and
     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.
    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. In those areas of 
Indian country, the 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).
    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 minority populations and low-income 
populations to the

[[Page 88012]]

greatest extent practicable and permitted by law. The EPA defines 
environmental justice (EJ) as ``the fair treatment and meaningful 
involvement of all people regardless of race, color, national origin, 
or income with respect to the development, implementation, and 
enforcement of environmental laws, regulations, and policies.'' The EPA 
further defines the term fair treatment to mean that ``no group of 
people should bear a disproportionate burden of environmental harms and 
risks, including those resulting from the negative environmental 
consequences of industrial, governmental, and commercial operations or 
programs and policies.''
    The EPA performed an environmental justice analysis, as is 
described in section VI of this proposed rule, titled ``Environmental 
Justice Considerations.'' The analysis was done for the purpose of 
providing additional context and information about this rulemaking to 
the public, not as a basis of the 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. In addition, 
there is no information in the record upon which this decision is based 
inconsistent with the stated goal of E.O. 12898 of achieving 
environmental justice for people of color, low-income populations, and 
Indigenous peoples.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Ammonia, 
Incorporation by reference, Intergovernmental relations, Nitrogen 
dioxide, Particulate matter, Reporting and recordkeeping requirements, 
Sulfur dioxide, Volatile organic compounds.

    Authority: 42 U.S.C. 7401 et seq.

    Dated: December 12, 2023.
Martha Guzman Aceves,
Regional Administrator, Region IX.
[FR Doc. 2023-27686 Filed 12-19-23; 8:45 am]
BILLING CODE 6560-50-P


