Proposed Rule2023-14687
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
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Published
July 14, 2023
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is proposing to approve portions of state implementation plan (SIP) revisions submitted by the State of California to meet Clean Air Act (CAA or "Act") requirements for the 1997 annual fine particulate matter (PM<INF>2.5</INF>) national ambient air quality standards (NAAQS or "standards") in the San Joaquin Valley PM<INF>2.5</INF> nonattainment area. Specifically, the EPA is proposing to approve those portions of the submitted SIP revisions as they pertain to the Serious nonattainment area and CAA section 189(d) requirements for the 1997 annual PM<INF>2.5</INF> NAAQS, except for the requirement for contingency measures. In addition, the EPA is proposing to approve 2020 and 2023 motor vehicle emissions budgets and the trading mechanism for use in transportation conformity analyses for the 1997 annual PM<INF>2.5</INF> NAAQS. The EPA will accept comments on this proposed rule during a 30-day public comment period.
Full Text
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<title>Federal Register, Volume 88 Issue 134 (Friday, July 14, 2023)</title>
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[Federal Register Volume 88, Number 134 (Friday, July 14, 2023)]
[Proposed Rules]
[Pages 45276-45323]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-14687]
[[Page 45275]]
Vol. 88
Friday,
No. 134
July 14, 2023
Part II
Environmental Protection Agency
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40 CFR Part 52
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; Proposed Rule
Federal Register / Vol. 88, No. 134 / Friday, July 14, 2023 /
Proposed Rules
[[Page 45276]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R09-OAR-2023-0263; FRL-10941-01-R9]
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
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
approve portions of state implementation plan (SIP) revisions submitted
by the State of California to meet Clean Air Act (CAA or ``Act'')
requirements for the 1997 annual fine particulate matter
(PM<INF>2.5</INF>) national ambient air quality standards (NAAQS or
``standards'') in the San Joaquin Valley PM<INF>2.5</INF> nonattainment
area. Specifically, the EPA is proposing to approve those portions of
the submitted SIP revisions as they pertain to the Serious
nonattainment area and CAA section 189(d) requirements for the 1997
annual PM<INF>2.5</INF> NAAQS, except for the requirement for
contingency measures. In addition, the EPA is proposing to approve 2020
and 2023 motor vehicle emissions budgets and the trading mechanism for
use in transportation conformity analyses for the 1997 annual
PM<INF>2.5</INF> NAAQS. The EPA will accept comments on this proposed
rule during a 30-day public comment period.
DATES: Any comments on this proposal must be received by August 14,
2023.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2023-0263 at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. For comments submitted at
<a href="http://Regulations.gov">Regulations.gov</a>, follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
<a href="http://Regulations.gov">Regulations.gov</a>. The EPA may publish any comment received to its public
docket. Do not submit electronically any information you consider to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Multimedia submissions (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 <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>. If you need assistance in a
language other than English or if you are a person with a disability
who needs a reasonable accommodation at no cost to you, please contact
the person identified in the FOR FURTHER INFORMATION CONTACT section.
FOR FURTHER INFORMATION CONTACT: Ashley Graham, Geographic Strategies
and Modeling Section (AIR-2-2), EPA Region IX, 75 Hawthorne Street, San
Francisco, CA 94105, (415) 972-3877, or by email at
<a href="/cdn-cgi/l/email-protection#274055464f464a0946544f4b425e556742574609404851"><span class="__cf_email__" data-cfemail="8deaffece5ece0a3ecfee5e1e8f4ffcde8fdeca3eae2fb">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us,''
and ``our'' refer to the EPA.
Table of Contents
I. Background for Proposed Action
A. PM<INF>2.5</INF> NAAQS
B. San Joaquin Valley PM<INF>2.5</INF> Designations,
Classifications, and SIP Revisions
II. Summary and Completeness Review of the San Joaquin Valley
PM<INF>2.5</INF> Plan
A. 2018 PM<INF>2.5</INF> Plan and 15 [micro]g/m\3\ SIP Revision
B. Procedural Requirements for SIPs and SIP Revisions
III. Clean Air Act Requirements for PM<INF>2.5</INF> Serious Area
Plans and for Serious PM<INF>2.5</INF> Areas That Fail To Attain
A. Requirements for PM<INF>2.5</INF> Serious Area Plans
B. Requirements for Serious PM<INF>2.5</INF> Areas That Fail To
Attain
IV. Review of the San Joaquin Valley PM<INF>2.5</INF> Plan for the
1997 Annual PM<INF>2.5</INF> NAAQS
A. Emissions Inventories
B. PM<INF>2.5</INF> Precursors
C. Attainment Plan Control Strategy
D. Attainment Demonstration and Modeling
E. Reasonable Further Progress and Quantitative Milestones
F. Motor Vehicle Emission Budgets
G. Nonattainment New Source Review Requirements Under CAA
Section 189(e)
V. Environmental Justice Considerations
VI. CAA Section 110(a)(2)(E)(i) ``Necessary Assurances'' and Title
VI of the Civil Rights Act of 1964
VII. Summary of Proposed Action and Request for Public Comment
VIII. Statutory and Executive Order Reviews
I. Background for Proposed Action
A. PM<INF>2.5</INF> NAAQS
Under section 109 of the CAA, the EPA has established NAAQS for
certain pervasive air pollutants (referred to as ``criteria
pollutants'') and conducts periodic reviews of the NAAQS to determine
whether the EPA should revise or establish new NAAQS to protect public
health.
On July 18, 1997, the EPA revised the NAAQS for particulate matter
by establishing new NAAQS for particles with an aerodynamic diameter
less than or equal to a nominal 2.5 micrometers (PM<INF>2.5</INF>).\1\
The EPA established primary and secondary annual and 24-hour standards
for PM<INF>2.5</INF>.\2\ The EPA set the annual primary and secondary
standards at 15.0 micrograms per cubic meter ([mu]g/m\3\) based on a
three-year average of annual mean PM<INF>2.5</INF> concentrations, and
set the 24-hour primary and secondary standards at 65 [mu]g/m\3\ based
on the three-year average of the 98th percentile of 24-hour
PM<INF>2.5</INF> concentrations at each monitoring site within an
area.\3\ Collectively, we refer herein to the 1997 annual and 24-hour
PM<INF>2.5</INF> NAAQS as the ``1997 PM<INF>2.5</INF> NAAQS'' or ``1997
PM<INF>2.5</INF> standards.''
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\1\ 62 FR 38652.
\2\ For a given air pollutant, ``primary'' NAAQS are those
determined by the EPA as requisite to protect the public health,
allowing an adequate margin of safety, and ``secondary'' standards
are those determined by the EPA as requisite to protect the public
welfare from any known or anticipated adverse effects associated
with the presence of such air pollutant in the ambient air. See CAA
section 109(b).
\3\ 40 CFR 50.7.
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On October 17, 2006, the EPA revised the level of the 24-hour
PM<INF>2.5</INF> NAAQS to 35 [mu]g/m\3\,\4\ and on January 15, 2013,
the EPA revised the level of the primary annual PM<INF>2.5</INF> NAAQS
to 12.0 [mu]g/m\3\.\5\ Even though the EPA lowered the 24-hour and
annual PM<INF>2.5</INF> NAAQS, the 1997 24-hour PM<INF>2.5</INF> NAAQS
remain in effect and the 1997 primary annual PM<INF>2.5</INF> NAAQS
remains in effect in areas designated nonattainment for that NAAQS.\6\
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\4\ 71 FR 61144.
\5\ 78 FR 3086.
\6\ 40 CFR 50.13(d).
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The EPA established each of the PM<INF>2.5</INF> NAAQS after
considering substantial evidence from numerous health studies
demonstrating that serious health effects are associated with exposures
to PM<INF>2.5</INF> concentrations above these levels. Epidemiological
studies have shown statistically significant correlations between
elevated PM<INF>2.5</INF> levels and premature mortality. Other
important health effects associated with PM<INF>2.5</INF> 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 dates), changes
in lung function and increased respiratory
[[Page 45277]]
symptoms, and new evidence for more subtle indicators of cardiovascular
health. Individuals particularly sensitive to PM<INF>2.5</INF> exposure
include older adults, people with heart and lung disease, and
children.\7\
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\7\ 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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PM<INF>2.5</INF> can be particles emitted by sources directly into
the atmosphere as a solid or liquid particle (``primary
PM<INF>2.5</INF>'' or ``direct PM<INF>2.5</INF>''), or can be particles
that form in the atmosphere as a result of various chemical reactions
from PM<INF>2.5</INF> precursor emissions emitted by sources
(``secondary PM<INF>2.5</INF>''). The EPA has identified the precursors
of PM<INF>2.5</INF> to be oxides of nitrogen (``NO<INF>X</INF>''),
sulfur oxides (``SO<INF>X</INF>''), volatile organic compounds
(``VOC''), and ammonia.\8\
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\8\ For example, see 72 FR 20586, 20589 (April 25, 2007).
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B. San Joaquin Valley PM<INF>2.5</INF> Designations, Classifications,
and SIP Revisions
Following promulgation of a new or revised NAAQS, the EPA is
required under CAA section 107(d) to designate areas throughout the
nation as attainment, nonattainment, or unclassifiable for the NAAQS.
Effective April 5, 2005, the EPA established the initial air quality
designations for the 1997 annual and 24-hour PM<INF>2.5</INF> NAAQS,
using air quality monitoring data for the three-year periods of 2001-
2003 and 2002-2004.\9\ The EPA designated the San Joaquin Valley as
nonattainment for both the 1997 annual PM<INF>2.5</INF> NAAQS (15.0
[micro]g/m\3\) and the 1997 24-hour PM<INF>2.5</INF> NAAQS (65
[micro]g/m\3\).\10\
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\9\ 70 FR 944 (January 5, 2005).
\10\ 40 CFR 81.305.
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The San Joaquin Valley PM<INF>2.5</INF> nonattainment area
encompasses over 23,000 square miles and includes all or part of eight
counties: San Joaquin, Stanislaus, Merced, Madera, Fresno, Tulare,
Kings, and the valley portion of Kern.\11\ The area is home to four
million people and is one of the nation's leading agricultural regions.
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. Under State law, the San Joaquin Valley Unified Air Pollution
Control District (SJVUAPCD or ``District'') has primary responsibility
for developing plans to provide for attainment of the NAAQS in this
area. The District works cooperatively with the California Air
Resources Board (CARB) in preparing attainment plans. Authority for
regulating sources under State jurisdiction in the San Joaquin Valley
is split under State law between the District, which has responsibility
for regulating stationary and most area sources, and CARB, which has
responsibility for regulating most mobile sources.
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\11\ For a precise description of the geographic boundaries of
the San Joaquin Valley nonattainment area, see 40 CFR 81.305.
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At the time of the initial designations for the 1997
PM<INF>2.5</INF> NAAQS, the EPA interpreted the CAA to require
implementation of the NAAQS under the general nonattainment plan
requirements of subpart 1.\12\ Under subpart 1, states were required to
submit nonattainment plan SIP submissions within three years of the
effective date of designations, that, among other things, provided for
implementation of reasonably available control measures (RACM),
reasonable further progress (RFP), contingency measures, and a modeled
attainment demonstration showing attainment of the NAAQS as
expeditiously as practicable but no later than five years from the
designation (in this instance, no later than April 5, 2010) unless the
state justified an attainment date extension of up to five years.\13\
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\12\ 72 FR 20586.
\13\ CAA sections 172(a)(2), 172(c)(1), 172(c)(2), and
172(c)(9).
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Between 2007 and 2011, California submitted six nonattainment plan
and supporting SIP revisions to address nonattainment area planning
requirements for the 1997 PM<INF>2.5</INF> NAAQS in the San Joaquin
Valley,\14\ which we refer to collectively as the ``2008
PM<INF>2.5</INF> Plan.'' On November 9, 2011, the EPA approved the
portions of the 2008 PM<INF>2.5</INF> Plan, as revised in 2009 and
2011, that addressed attainment of the 1997 PM<INF>2.5</INF> NAAQS in
the San Joaquin Valley nonattainment area, except for the attainment
contingency measures, which we disapproved.\15\ We also granted the
State's request to extend the attainment deadline for the 1997
PM<INF>2.5</INF> NAAQS in the San Joaquin Valley to April 5, 2015.\16\
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\14\ 76 FR 69896, n. 2 (November 9, 2011).
\15\ Id. at 69924.
\16\ Id.
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Following a January 4, 2013 decision of the U.S. Court of Appeals
for the D.C. Circuit remanding the EPA's 2007 implementation rule for
the 1997 PM<INF>2.5</INF> NAAQS,\17\ the EPA published a final rule on
June 2, 2014, classifying the San Joaquin Valley as a ``Moderate''
nonattainment area for the 1997 PM<INF>2.5</INF> NAAQS under subpart 4,
part D of title I of the Act.\18\ In that action, the EPA acknowledged
that states must meet both subpart 1 and subpart 4 requirements in
nonattainment plan SIP submissions for the 1997 24-hour and annual
PM<INF>2.5</INF> NAAQS and provided states with additional time to
supplement or withdraw and resubmit any pending nonattainment plan SIP
submissions.
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\17\ Natural Resources Defense Council v. EPA, 706 F.3d. 428
(D.C. Cir. 2013) (``NRDC''). In NRDC, the court held that the EPA
erred in implementing the 1997 PM<INF>2.5</INF> standards solely
pursuant to the general implementation requirements of subpart 1,
without also considering the requirements specific to nonattainment
areas for particles less than or equal to 10 [micro]m in diameter
(PM<INF>10</INF>) in subpart 4, part D of title I of the CAA. The
court reasoned that the plain meaning of the CAA requires
implementation of the 1997 PM<INF>2.5</INF> standards under subpart
4 because PM<INF>2.5</INF> falls within the statutory definition of
PM<INF>10</INF> and is thus subject to the same statutory
requirements as PM<INF>10</INF>. The court remanded the rule,
without vacatur, and instructed the EPA ``to repromulgate these
rules pursuant to Subpart 4 consistent with this opinion.''
\18\ 79 FR 31566.
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Effective May 7, 2015, the EPA reclassified the San Joaquin Valley
as a ``Serious'' nonattainment area for the 1997 PM<INF>2.5</INF> NAAQS
based on our determination that the State could not practicably attain
these NAAQS in the San Joaquin Valley nonattainment area by the latest
statutory Moderate area attainment date, i.e., April 5, 2015.\19\ Upon
reclassification as a Serious area, the State became subject to the
requirement of CAA section 188(c)(2) to attain the 1997
PM<INF>2.5</INF> NAAQS as expeditiously as practicable but no later
than ten years after designation, i.e., by no later than December 31,
2015. California submitted its Serious area plan for the 1997
PM<INF>2.5</INF> NAAQS for the San Joaquin Valley in two submissions
dated June 25, 2015, and August 13, 2015, including a request under
section 188(e) to extend the attainment date for the 1997 24-hour
PM<INF>2.5</INF> NAAQS by three years (to December 31, 2018) and to
extend the attainment date for the 1997 annual PM<INF>2.5</INF> NAAQS
by five years (to December 31, 2020). On February 9, 2016, the EPA
proposed to approve most of the Serious area plan and to grant the
State's request for extensions of the December 31, 2015 attainment
date.\20\ However, on October 6, 2016, after considering public
comments, the EPA denied California's request for these extensions of
the attainment dates.\21\ Consequently, on November 23, 2016, the EPA
determined that the San Joaquin Valley had failed to attain the 1997
24-hour and annual PM<INF>2.5</INF> NAAQS
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by the December 31, 2015 Serious area attainment date.\22\ This
determination triggered a requirement for California to submit a new
SIP submission for the 1997 24-hour and annual PM<INF>2.5</INF> NAAQS
for the San Joaquin Valley that satisfies the requirements of CAA
section 189(d). The statutory deadline for this additional SIP
submission was December 31, 2016. The EPA did not finalize the actions
proposed on February 9, 2016, with respect to the submitted Serious
area plan.\23\
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\19\ 80 FR 18528 (April 7, 2015).
\20\ 81 FR 6936. California's request for extension of the
Serious Area attainment date for the San Joaquin Valley accompanied
its Serious Area attainment plan for the 1997 PM<INF>2.5</INF> NAAQS
and related motor vehicle emission budgets, submitted June 25, 2015
and August 13, 2015, respectively.
\21\ 81 FR 69396.
\22\ 81 FR 84481.
\23\ 81 FR 69396, 69400.
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On December 6, 2018, the EPA determined that California had failed
to submit a complete section 189(d) attainment plan for the 1997 24-
hour and annual PM<INF>2.5</INF> NAAQS, among other required SIP
submissions for the San Joaquin Valley, by the statutory deadlines.\24\
This finding, which became effective on January 7, 2019, triggered
clocks under CAA section 179(a) for the application of emissions offset
sanctions 18 months after the finding, and highway funding sanctions 6
months thereafter, unless the EPA affirmatively determined that the
State made a complete SIP submission addressing the identified failure
to submit deficiencies.\25\ The finding also triggered the obligation
under CAA section 110(c) for the EPA to promulgate a federal
implementation plan no later than two years after the finding, unless
the State has submitted, and the EPA has approved, the required SIP
submission.\26\
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\24\ 83 FR 62720.
\25\ Id. at 62723.
\26\ Id.
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On May 10, 2019, CARB submitted the ``2018 Plan for the 1997, 2006,
and 2012 PM<INF>2.5</INF> Standards,'' adopted by the SJVUAPCD on
November 15, 2018, and by CARB on January 24, 2019 (``2018
PM<INF>2.5</INF> Plan'').\27\ The 2018 PM<INF>2.5</INF> Plan addresses
the Serious area nonattainment plan and CAA section 189(d) requirements
for the 1997 24-hour and annual PM<INF>2.5</INF> NAAQS, among other
requirements for the 2006 and 2012 PM<INF>2.5</INF> NAAQS.\28\ The 2018
PM<INF>2.5</INF> Plan incorporates by reference the ``San Joaquin
Valley Supplement to the 2016 State Strategy for the State
Implementation Plan'' (``Valley State SIP Strategy''), a related plan
adopted by CARB on October 25, 2018, and submitted to the EPA with the
2018 PM<INF>2.5</INF> Plan on May 10, 2019.\29\ CARB clarified in its
submittal letter that the 2018 PM<INF>2.5</INF> Plan superseded past
submissions to the EPA that the agency had not yet acted on for the
1997 PM<INF>2.5</INF> NAAQS, including the 2015 Serious area attainment
plan submissions.\30\ On June 24, 2020, the EPA issued a letter finding
these submissions complete and terminating the sanctions clocks under
CAA section 179(a).\31\
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\27\ Letter dated May 9, 2019, from Richard Corey, Executive
Officer, CARB, to Mike Stoker, Regional Administrator, EPA Region 9.
\28\ The EPA previously acted on those portions of the 2018
PM<INF>2.5</INF> Plan that pertain to the 2006 24-hour
PM<INF>2.5</INF> NAAQS (except for contingency measures) (85 FR
44192, July 22, 2020), and Moderate area planning requirements for
the 2012 annual PM<INF>2.5</INF> NAAQS and 2006 24-hour
PM<INF>2.5</INF> NAAQS contingency measures (86 FR 67343, November
26, 2021). On December 29, 2021, the EPA proposed action on those
portions of the plan that pertain to the Serious area requirements
for the 2012 annual PM<INF>2.5</INF> NAAQS (86 FR 74310). On October
5, 2022, the EPA issued a supplemental proposal with respect to the
Serious area requirements for the 2012 PM<INF>2.5</INF> NAAQS (87 FR
60494), and on October 27, 2022, California withdrew those portions
of the plan that pertained to those requirements (letter dated
October 27, 2022, from Steven S. Cliff, Executive Officer, CARB, to
Martha Guzman, Regional Administrator, EPA Region IX).
\29\ Id.
\30\ The 2015 Serious area attainment plan submissions include
the ``2015 Plan for the 1997 Standard'' (submitted by CARB on June
25, 2015) and motor vehicle emission budgets (submitted by CARB
August 13, 2015)
\31\ Letter dated June 24, 2020, from Elizabeth J. Adams,
Director, Air and Radiation Division, EPA Region IX, to Richard
Corey, Executive Officer, CARB, Subject: ``RE: Completeness Finding
for State Implementation Plan (SIP) Submissions for San Joaquin
Valley for the 1997, 2006, and 2012 Fine Particulate Matter
(PM<INF>2.5</INF>) National Ambient Air Quality Standards (NAAQS)
and Termination of Clean Air Act (CAA) Sanction Clocks.''
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On January 28, 2022, the EPA approved those portions of the 2018
PM<INF>2.5</INF> Plan that pertain to the 1997 24-hour PM<INF>2.5</INF>
NAAQS, except for the contingency measure element, which the EPA
disapproved.\32\ As part of that action, the EPA also finalized a
determination that the San Joaquin Valley attained the 1997 24-hour
PM<INF>2.5</INF> NAAQS by the applicable attainment date of December
31, 2020 and that therefore the requirement for contingency measures no
longer applies in the San Joaquin Valley nonattainment area for the
1997 24-hour PM<INF>2.5</INF> NAAQS.\33\ Because the EPA found that the
State has satisfied its planning obligations for the San Joaquin Valley
with respect to the 1997 24-hour PM<INF>2.5</INF> NAAQS, this proposed
action addresses only the requirements for the 1997 annual
PM<INF>2.5</INF> NAAQS.
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\32\ 87 FR 4503 (January 28, 2022).
\33\ Id at 4506.
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On July 22, 2021, the EPA proposed to partially approve and
partially disapprove portions of the 2018 PM<INF>2.5</INF> Plan that
address attainment of the 1997 annual PM<INF>2.5</INF> NAAQS in the San
Joaquin Valley nonattainment area.\34\ The EPA proposed to approve the
2013 base year emissions inventories and disapprove the attainment
demonstration and related elements, including the comprehensive
precursor demonstration, five percent annual emissions reductions
demonstration, best available control measures (BACM) demonstration,
RFP demonstration, quantitative milestones, and motor vehicle emission
budgets established for 2017, 2020, and 2023. We proposed to disapprove
the attainment demonstration and related elements because certified air
quality data were available that established that the San Joaquin
Valley area did not attain the 1997 annual PM<INF>2.5</INF> NAAQS by
December 31, 2020, as projected in the 2018 PM<INF>2.5</INF> Plan. The
EPA also proposed to disapprove the contingency measures element
because of several identified deficiencies, including that the measure
did not address the potential for failures to meet RFP, to meet a
quantitative milestone, or to submit a quantitative milestone
report.\35\ On November 26, 2021, the EPA finalized the partial
approval and partial disapproval of the 2018 PM<INF>2.5</INF> Plan for
the 1997 annual PM<INF>2.5</INF> NAAQS as proposed.\36\
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\34\ 86 FR 38652.
\35\ Id. at 38669.
\36\ 86 FR 67329.
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As a result of the November 26, 2021 disapprovals, California was
required to develop and submit a revised attainment plan for the San
Joaquin Valley area that addresses the applicable CAA requirements,
including the Serious area plan requirements and the requirements of
CAA section 189(d), for the 1997 annual PM<INF>2.5</INF> NAAQS. In
accordance with sections 179(d)(3) and 172(a)(2) of the CAA, the
revised plan must demonstrate attainment of these NAAQS as
expeditiously as practicable and no later than 5 years from the date of
the EPA's prior determination that the area failed to attain (i.e., by
November 23, 2021), except that the EPA may extend the attainment date
to a date no later than 10 years from the date of this determination
(i.e., to November 23, 2026), ``considering the severity of
nonattainment and the availability and feasibility of pollution control
measures.'' \37\
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\37\ 81 FR 84481, 84482 (final EPA action determining that the
San Joaquin Valley had failed to attain the 1997 PM<INF>2.5</INF>
NAAQS by the December 31, 2015, Serious area attainment date).
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On November 8, 2021, CARB submitted the ``Attainment Plan Revision
for the 1997 Annual PM<INF>2.5</INF> Standard'' (``15 [micro]g/m\3\ SIP
Revision''), adopted by the SJVUAPCD on August 19, 2021, and adopted by
CARB on September 23, 2021.\38\ In the letter
[[Page 45279]]
accompanying the submission, CARB clarifies that the 15 [micro]g/m\3\
SIP Revision amends the 2018 PM<INF>2.5</INF> Plan and addresses all
CAA requirements for the 1997 annual PM<INF>2.5</INF> NAAQS except for
contingency measures, which CARB stated it will address at a later
date.\39\
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\38\ Letter dated November 8, 2021, from Richard W. Corey,
Executive Officer, CARB, to Deborah Jordan, Acting Regional
Administrator, EPA Region 9. The 15 [micro]g/m\3\ SIP Revision was
developed jointly by CARB and the District.
\39\ Id. at 1.
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II. Summary and Completeness Review of the San Joaquin Valley PM2.5
Plan
We are proposing action on those portions of the 15 [micro]g/m\3\
SIP Revision, 2018 PM<INF>2.5</INF> Plan, and Valley State SIP Strategy
that pertain to the 1997 annual PM<INF>2.5</INF> NAAQS. Herein, we
refer to these three submissions collectively as the ``SJV
PM<INF>2.5</INF> Plan'' or ``Plan.'' The SJV PM<INF>2.5</INF> Plan
addresses Serious area nonattainment plan and CAA section 189(d)
requirements for the 1997 annual PM<INF>2.5</INF> NAAQS in the San
Joaquin Valley, including the State's demonstration that the area will
attain the 1997 annual PM<INF>2.5</INF> NAAQS by December 31, 2023.
A. 2018 PM<INF>2.5</INF> Plan and 15 [micro]g/m\3\ SIP Revision
CARB and the District describe the 15 [micro]g/m\3\ SIP Revision as
an ``administrative revision'' to the 2018 PM<INF>2.5</INF> Plan that
``has been prepared as a streamlined document that utilizes the
existing emissions inventory, air quality analysis and modeling from
the 2018 PM<INF>2.5</INF> Plan.'' \40\ In its submission of the 15
[micro]g/m\3\ SIP Revision to the EPA, the State included a redline
strikeout version highlighting the updates that were made relative to
the 2018 PM<INF>2.5</INF> Plan submitted on May 10, 2019, as well as
final versions of those sections that were revised relative to the 2018
PM<INF>2.5</INF> Plan.
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\40\ 15 [micro]g/m\3\ SIP Revision, p. 5.
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The State updated the following portions of the 2018
PM<INF>2.5</INF> Plan and resubmitted them to the EPA as the 15
[micro]g/m\3\ SIP Revision to address both the Serious area
requirements in CAA section 189(b) and the CAA section 189(d)
requirements for the 1997 annual PM<INF>2.5</INF> NAAQS in the San
Joaquin Valley: (i) Chapter 4 (``Attainment Strategy for
PM<INF>2.5</INF>''); (ii) Chapter 5 (``Demonstration of Federal
Requirements for 1997 PM<INF>2.5</INF> Standards''); (iii) Appendix D
(``Mobile Source Control Measure Analyses''); (iv) Appendix H (``RFP,
Quantitative Milestones, and Contingency''); and (v) Appendix K
(``Modeling Attainment Demonstration''). The November 8, 2021 submittal
package also included CARB's ``Staff Report, Proposed SIP Revision for
the 15 ug/m3 Annual PM<INF>2.5</INF> Standard for the San Joaquin
Valley,'' release date August 13, 2021 (``August 2021 Staff
Report''),\41\ and the State's and District's board resolutions
adopting the 15 [micro]g/m\3\ SIP Revision (CARB Resolution 21-21 and
SJVUAPCD Governing Board Resolution 21-08-13).\42\
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\41\ CARB's August 2021 Staff Report includes CARB's review of,
among other things, the control strategy in the 15 [micro]g/m\3\ SIP
Revision and assessment of the differences between the emissions
inventories in the Plan and updated inventories more recently
developed by CARB.
\42\ CARB Resolution 21-21, ``San Joaquin Valley State
Implementation Plan Revision for the 15 [mu]g/m\3\ Annual
PM<INF>2.5</INF> Standard,'' September 23, 2021, and SJVUAPCD
Governing Board Resolution 21-08-13, ``Adopting the San Joaquin
Valley Unified Air Pollution Control District Proposed Attainment
Plan Revision For the 1997 Annual PM<INF>2.5</INF> Standard,''
August 19, 2021.
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The portions of the Plan that address the requirements for the 1997
annual PM<INF>2.5</INF> NAAQS and that the State did not revise
relative to the 2018 PM<INF>2.5</INF> Plan include: (i) Appendix A
(``Ambient PM<INF>2.5</INF> Data Analysis''); (ii) Appendix B
(``Emissions Inventory''); (iii) Appendix C (``Stationary Source
Control Measure Analyses''); (iv) Appendix G (``Precursor
Demonstration''); (v) Appendix I (``New Source Review and Emission
Reduction Credits''); (vi) Appendix J (``Modeling Emission
Inventory''); and (vii) Appendix L (``Modeling Protocol''). The May 10,
2019 submittal package also included CARB's ``Staff Report, Review of
the San Joaquin Valley 2018 Plan for the 1997, 2006, and 2012
PM<INF>2.5</INF> Standards,'' release date December 21, 2018
(``December 2018 Staff Report''); \43\ and the State's and District's
board resolutions adopting the 2018 PM<INF>2.5</INF> Plan (CARB
Resolution 19-1 and SJVUAPCD Governing Board Resolution 18-11-16).\44\
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\43\ Letter dated December 11, 2019, from Richard Corey,
Executive Officer, CARB, to Mike Stoker, Regional Administrator, EPA
Region 9, transmitting the December 2018 Staff Report. The December
2018 Staff Report includes CARB's review of, among other things, the
2018 PM<INF>2.5</INF> Plan's control strategy and attainment
demonstration.
\44\ CARB Resolution 19-1, ``2018 PM<INF>2.5</INF> State
Implementation Plan for the San Joaquin Valley,'' January 24, 2019,
and SJVUAPCD Governing Board Resolution 18-11-16, ``Adopting the
[SJVUAPCD] 2018 Plan for the 1997, 2006, and 2012 PM<INF>2.5</INF>
Standards,'' November 15, 2018.
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As noted above, the 2018 PM<INF>2.5</INF> Plan incorporates by
reference the Valley State SIP Strategy. For the purposes of this
action, the relevant portions of the Valley State SIP Strategy are the
mobile source control measure commitments associated with the
quantitative milestones for the 1997 annual PM<INF>2.5</INF> NAAQS.
B. Procedural Requirements for SIPs and SIP Revisions
CAA sections 110(a)(1) and (2) and 110(l) require each state to
provide reasonable public notice and opportunity for public hearing
prior to the adoption and submission of a SIP or SIP revision to the
EPA. To meet this requirement, every SIP submission should include
evidence that the State provided adequate public notice and an
opportunity for a public hearing consistent with the EPA's implementing
regulations in 40 CFR 51.102.
Both the District and CARB satisfied the applicable statutory and
regulatory requirements for reasonable public notice and hearing prior
to adoption and submission of the 2018 PM<INF>2.5</INF> Plan and 15
[micro]g/m\3\ SIP Revision. The District provided public notice and
opportunity for public comment prior to its November 15, 2018 public
hearing on and adoption of the 2018 PM<INF>2.5</INF> Plan.\45\ CARB
also provided public notice and opportunity for public comment prior to
its January 24, 2019 public hearing on and adoption of the 2018
PM<INF>2.5</INF> Plan.\46\ Subsequently, the District provided public
notice and opportunity for public comment prior to its August 19, 2021
public hearing on and adoption of the 15 [micro]g/m\3\ SIP
Revision.\47\ CARB also provided public notice and opportunity for
public comment prior to its September 23, 2021 public hearing on and
adoption of the 15 [micro]g/m\3\ SIP Revision.\48\ The SIP submissions
include proof of publication of notices for the respective public
hearings. They also include copies of the written and oral comments
received during the State's and District's public review processes and
the agencies' responses thereto.<SUP>49 50</SUP> Therefore, we find
that the
[[Page 45280]]
2018 PM<INF>2.5</INF> Plan and 15 [micro]g/m\3\ SIP Revision meet the
procedural requirements for public notice and hearing in CAA sections
110(a) and 110(l) and 40 CFR 51.102.
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\45\ SJVUAPCD, ``Notice of Public Hearing for Adoption of
Proposed 2018 PM<INF>2.5</INF> Plan for the 1997, 2006, and 2012
Standards,'' October 16, 2018, and SJVUAPCD Governing Board
Resolution 18-11-16.
\46\ CARB, ``Notice of Public Meeting to Consider the 2018
PM<INF>2.5</INF> State Implementation Plan for the San Joaquin
Valley,'' December 21, 2018, and CARB Resolution 19-1.
\47\ SJVUAPCD, ``Notice of Public Hearing: Adopt Attainment Plan
Revision for the 1997 Annual PM<INF>2.5</INF> Standard,'' July 20,
2021, and SJVUAPCD Governing Board Resolution 21-08-13.
\48\ CARB, ``Notice of Public Meeting to Hear an Update on the
2018 PM<INF>2.5</INF> State Implementation Plan for the San Joaquin
Valley and Consider a State Implementation Plan Revision for the 15
[micro]g/m\3\ Annual PM<INF>2.5</INF> Standard,'' September 23,
2021, and CARB Resolution 21-21.
\49\ CARB, ``Board Meeting Comments Log,'' March 29, 2019; J&K
Court Reporting, LLC, ``Meeting, State of California Air Resources
Board,'' January 24, 2019 (transcript of CARB's public hearing), and
2018 PM<INF>2.5</INF> Plan, Appendix M (``Summary of Significant
Comments and Responses'').
\50\ CARB, ``Board Meeting Comments Log,'' September 23, 2021;
J&K Court Reporting, LLC, ``Videoconference Meeting, State of
California Air Resources Board,'' September 23, 2021 (transcript of
CARB's public hearing).
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CAA section 110(k)(1)(B) requires the EPA to determine whether a
SIP submission is complete within 60 days of receipt. This section also
provides that any plan that the EPA has not affirmatively determined to
be complete or incomplete will become complete by operation of law six
months after the date of submission. The EPA's SIP completeness
criteria are found in 40 CFR part 51, Appendix V.
We have reviewed the 15 [micro]g/m\3\ SIP Revision for completeness
and find that it meets the completeness criteria in 40 CFR part 51
Appendix V. On May 8, 2022, the 15 [micro]g/m\3\ SIP Revision was
deemed complete by operation of law under CAA section 110(k)(1)(B). The
2018 PM<INF>2.5</INF> Plan and Valley State SIP Strategy became
complete by operation of law on November 10, 2019, and the EPA
subsequently issued a letter making an affirmative completeness finding
and terminating the sanctions clocks under CAA section 179(a) on June
24, 2020.\51\
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\51\ Letter dated June 24, 2020, from Elizabeth J. Adams,
Director, Air and Radiation Division, EPA Region IX, to Richard
Corey, Executive Officer, CARB, Subject: ``RE: Completeness Finding
for State Implementation Plan (SIP) Submissions for San Joaquin
Valley for the 1997, 2006, and 2012 Fine Particulate Matter
(PM<INF>2.5</INF>) National Ambient Air Quality Standards (NAAQS)
and Termination of Clean Air Act (CAA) Sanction Clocks.''
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III. Clean Air Act Requirements for PM2.5 Serious Area Plans and for
Serious PM2.5 Areas That Fail To Attain
A. Requirements for PM<INF>2.5</INF> Serious Area Plans
Upon reclassification of a Moderate nonattainment area as a Serious
nonattainment area under subpart 4 of part D, title I of the CAA, the
Act requires the state to make a SIP submission that addresses the
following Serious nonattainment area requirements: \52\
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\52\ 40 CFR 51.1003(b)(1); 81 FR 58010, 58074-58075 (August 24,
2016).
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1. A comprehensive, accurate, current inventory of actual emissions
from all sources of PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors in
the area (CAA section 172(c)(3));
2. Provisions to assure that BACM, including best available control
technology (BACT), for the control of direct PM<INF>2.5</INF> and
PM<INF>2.5</INF> precursors shall be implemented no later than four
years after the area is reclassified (CAA section 189(b)(1)(B)), unless
the state elects to make an optional precursor demonstration that the
EPA approves authorizing the state not to regulate one or more of these
pollutants;
3. A demonstration (including air quality modeling) that the plan
provides for attainment as expeditiously as practicable but no later
than the end of the tenth calendar year after designation as a
nonattainment area (i.e., December 31, 2015, for the San Joaquin Valley
for the 1997 PM<INF>2.5</INF> NAAQS);
4. Plan provisions that require RFP (CAA section 172(c)(2));
5. Quantitative milestones that are to be achieved every three
years until the area is redesignated attainment and that demonstrate
RFP toward attainment by the applicable date (CAA section 189(c));
6. Provisions to assure that control requirements applicable to
major stationary sources of PM<INF>2.5</INF> also apply to major
stationary sources of PM<INF>2.5</INF> precursors, except where the
state demonstrates to the EPA's satisfaction that such sources do not
contribute significantly to PM<INF>2.5</INF> levels that exceed the
standard in the area (CAA section 189(e));
7. Contingency measures to be implemented if the area fails to meet
RFP or to attain by the applicable attainment date (CAA section
172(c)(9)); and
8. A revision to the nonattainment new source review (NSR) program
to lower the applicable ``major stationary source'' \53\ thresholds
from 100 tons per year (tpy) to 70 tpy (CAA section 189(b)(3)).
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\53\ For any Serious area, the terms ``major source'' and
``major stationary source'' include any stationary source that emits
or has the potential to emit at least 70 tons per year of
PM<INF>2.5</INF>. CAA section 189(b)(3) and 40 CFR
51.165(a)(1)(iv)(A)(1)(vii) and (viii) (defining ``major stationary
source'' in Serious PM<INF>2.5</INF> nonattainment areas).
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A state's Serious area plan must also satisfy the requirements for
Moderate area plans in CAA section 189(a), to the extent the state has
not already met those requirements in the Moderate area plan submitted
for the area. In addition, the Serious area plan must meet the general
requirements applicable to all SIP submissions under section 110 of the
CAA, including the requirement to provide necessary assurances that the
implementing agencies have adequate personnel, funding, and authority
under section 110(a)(2)(E); and the requirements concerning enforcement
provisions in section 110(a)(2)(C).
B. Requirements for Serious PM2.5 Areas That Fail To Attain
In the event that a Serious area fails to attain the
PM<INF>2.5</INF> NAAQS by the applicable attainment date, CAA section
189(d) requires that ``the State in which such area is located shall,
after notice and opportunity for public comment, submit within 12
months after the applicable attainment date, plan revisions which
provide for attainment of the . . . standard . . .'' An attainment plan
under section 189(d) must, among other things, demonstrate expeditious
attainment of the NAAQS within the time period provided under CAA
section 179(d)(3) and provide for annual reductions in emissions of
direct PM<INF>2.5</INF> or a PM<INF>2.5</INF> plan precursor pollutant
within the area of not less than five percent per year from the most
recent emissions inventory for the area until attainment.\54\
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\54\ CAA section 189(d), 40 CFR 51.1004(a)(3), 40 CFR
51.1010(c).
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In addition to the requirement to submit control measures providing
for a five percent reduction in emissions of certain pollutants on an
annual basis, the EPA interprets CAA section 189(d) as requiring a
state to submit an attainment plan that includes the same basic
statutory plan elements that are required for other attainment
plans.\55\ Specifically, a state must submit to the EPA its plan to
meet the requirements of CAA section 189(d) in the form of a complete
attainment plan submission that includes the following elements: \56\
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\55\ 81 FR 58010, 58098.
\56\ 40 CFR 51.1003(c)(1).
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1. A comprehensive, accurate, current inventory of actual emissions
from all sources of PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors in
the area;
2. A Serious area plan control strategy that ensures that BACM,
including BACT, for the control of direct PM<INF>2.5</INF> and
PM<INF>2.5</INF> precursors are implemented in the area, unless the
state elects to make an optional precursor demonstration that the EPA
approves authorizing the state not to regulate one or more of these
pollutants;
3. Additional measures (beyond those already adopted in previous
nonattainment plan SIP submissions for the area as RACM/RACT, BACM/
BACT, and most stringent measures (MSM) (if applicable) \57\) that
provide for attainment of the NAAQS as expeditiously as practicable
and, from the date of such submission until attainment, demonstrate
that the plan will, at a minimum, achieve an annual five percent
reduction in emissions of direct PM<INF>2.5</INF> or any
PM<INF>2.5</INF> plan precursor;
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\57\ MSM is applicable if the EPA has previously granted an
extension of the attainment date under CAA section 188(e) for the
nonattainment area and NAAQS at issue.
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4. A demonstration (including air quality modeling) that the plan
provides
[[Page 45281]]
for attainment of the NAAQS at issue as expeditiously as practicable;
5. Plan provisions that require RFP;
6. Quantitative milestones that the state is to meet every three
years until the area is redesignated attainment and that demonstrate
RFP toward attainment by the applicable date;
7. Contingency measures to be implemented if the state fails to
meet any requirement concerning RFP or quantitative milestones or to
attain the NAAQS at issue by the applicable attainment date; and
8. Provisions to assure that control requirements applicable to
major stationary sources of PM<INF>2.5</INF>, also apply to major
stationary sources of PM<INF>2.5</INF> precursors, except where the
state demonstrates to the EPA's satisfaction that such sources do not
contribute significantly to PM<INF>2.5</INF> levels that exceed the
NAAQS at issue in the area.
A state's section 189(d) plan submission must demonstrate
attainment as expeditiously as practicable, and no later than 5 years
from the date of the EPA's determination that the area failed to
attain, except that the Administrator may extend the attainment date to
no later than 10 years from the failure to attain determination,
consistent with sections 179(d)(3) and 172(a)(2) of the CAA.\58\
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\58\ 81 FR 84481, 84482.
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A state with a Serious PM<INF>2.5</INF> nonattainment area that
fails to attain the NAAQS by the applicable Serious area attainment
date must also address any statutory requirements applicable to
Moderate and Serious nonattainment area plans under CAA sections 172
and 189 of the CAA to the extent that those requirements have not
already been met.\59\ Because the EPA has not previously approved a SIP
submission for the San Joaquin Valley as meeting the subpart 4 RACM
Moderate area planning requirements under CAA section 189 for the 1997
annual PM<INF>2.5</INF> NAAQS, the EPA is evaluating relevant portions
of the SJV PM<INF>2.5</INF> Plan for compliance with this requirement.
In addition, as discussed above, the EPA has not previously approved a
SIP submission for the San Joaquin Valley as meeting the Serious area
planning requirements under CAA section 189(b)(1) for the 1997 annual
PM<INF>2.5</INF> NAAQS. Some Serious area planning requirements operate
on a timeline that is based on the outermost statutory Serious area
attainment date of the end of the tenth calendar year following the
area's designation to nonattainment. Because section 189(d) requires a
state to address any applicable Serious area requirements that the
state has not already met in the area, and the section 189(d)
obligations do not come into effect until an area has failed to attain
the NAAQS by the Serious area attainment date, the EPA is evaluating
any previously unmet Serious area planning obligations based on the
current, applicable attainment date appropriate under section 189(d),
and not the original Serious area attainment date.\60\
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\59\ 81 FR 58010, 58098.
\60\ See, e.g., 86 FR 53150 (September 24, 2021) and 87 FR 4503
(January 28, 2022) (proposed and final actions evaluating a
previously unmet Serious area planning obligation based on the
applicable attainment date under section 189(d), not the original
Serious area attainment date).
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The EPA provided its preliminary 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''); \61\ (2) ``State
Implementation Plans; General Preamble for the Implementation of Title
I of the Clean Air Act Amendments of 1990; Supplemental''; \62\ 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'').\63\ More recently, in an August 24, 2016 final rule
entitled, ``Fine Particulate Matter National Ambient Air Quality
Standards: State Implementation Plan Requirements'' (``PM<INF>2.5</INF>
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 the
PM<INF>2.5</INF> NAAQS.\64\ We discuss these regulatory requirements
and interpretations of the Act as appropriate in our evaluation of the
SJV PM<INF>2.5</INF> Plan that follows.
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\61\ 57 FR 13498 (April 16, 1992).
\62\ 57 FR 18070 (April 28, 1992).
\63\ 59 FR 41998 (August 16, 1994).
\64\ 81 FR 58010.
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IV. Review of the San Joaquin Valley PM2.5 Plan for the 1997 Annual
PM2.5 NAAQS
The EPA is evaluating the SJV PM<INF>2.5</INF> Plan against the
Serious area requirements for the 1997 annual PM<INF>2.5</INF> NAAQS
and the section 189(d) requirements for the 1997 annual
PM<INF>2.5</INF> NAAQS, as laid out in Section III of this document.
Many requirements for both a Serious area plan and a section 189(d)
plan are structured around the relevant statutory attainment date. The
latest statutory Serious area attainment date for the San Joaquin
Valley area was December 31, 2015.\65\ On November 23, 2016, the EPA
determined that the area failed to attain by the Serious area
attainment date.
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\65\ As discussed in Section I.B of this proposal, California
submitted its Serious area plan for the 1997 annual PM<INF>2.5</INF>
NAAQS in two submissions dated June 25, 2015 and August 13, 2015,
including a request under section 188(e) to extend the attainment
date for the 1997 annual PM<INF>2.5</INF> NAAQS by five years (to
December 31, 2020). On October 6, 2016, the EPA denied the request
for an extension, but did not finalize action on the Serious area
plan submissions. Accordingly, the Serious area attainment date
remained unchanged: as expeditiously as practicable but no later
than December 31, 2015.
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For the purposes of the section 189(d) requirements, the attainment
date is the date by which a state can attain the NAAQS as expeditiously
as practicable, but no later than 5 years from the publication date of
the final determination of failure to attain, except that the EPA may
extend the attainment date to a date no later than 10 years from the
date of the determination (i.e., to November 23, 2026), ``considering
the severity of nonattainment and the availability and feasibility of
pollution control measures.'' \66\ The SJV PM<INF>2.5</INF> Plan
projects that attainment will be achieved by December 31, 2023,
approximately seven years after the determination of failure to attain.
The EPA is proposing to approve the SJV PM<INF>2.5</INF> Plan's
attainment date in this action.
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\66\ CAA section 172(a)(2) and 179(d)(3); 81 FR 84481, 84482.
The determination of failure to attain published on November 23,
2016.
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When the State submitted the 2018 PM<INF>2.5</INF> Plan in 2019,
the State withdrew its previous Serious area plan that it had developed
to meet the December 31, 2015 Serious area attainment date. Because the
State submitted the 2018 PM<INF>2.5</INF> Plan and subsequent 15
[micro]g/m\3\ SIP Revision after the EPA's finding that the area had
failed to attain by the applicable Serious area attainment date, the
State could not demonstrate that the area would attain by the Serious
area attainment date, nor could it address other requirements based on
this attainment date, such as RFP and quantitative milestones, because
many of the relevant dates had already passed. As described in Section
III of this document, in a section 189(d) plan, a state must address
any statutory requirements applicable to Moderate and Serious
nonattainment area plans to the extent that it has not already met
those requirements, but the EPA
[[Page 45282]]
believes that it should base this evaluation on the current applicable
attainment date under section 189(d). For example, it would be
illogical to require a state to submit a Serious area modeled
attainment demonstration that provided for attainment by December 31,
2015, after the EPA has already determined based on monitoring data
that the state failed to attain by such date.
For the purposes of our evaluation of the Serious area plan
requirements, although the State is required to submit a Serious area
plan and it must structure such a plan based on the Serious area
attainment date, it would serve no purpose to evaluate the SJV
PM<INF>2.5</INF> Plan against the now-passed Serious area attainment
date by which the area has already failed to attain. For example, RFP
and quantitative milestones normally are dependent upon the attainment
date. Accordingly, because the State must still meet all Serious area
plan requirements, even if doing so later in conjunction with the
section 189(d) plan and its later attainment date, we will evaluate the
State's compliance with the Serious area plan requirements in light of
the later section 189(d) attainment date, as appropriate. Where the
State in the SJV PM<INF>2.5</INF> Plan applies the section 189(d)
attainment date to a Serious area requirement, we will note the
statutory Serious area timeline and accept the submission in
fulfillment of the State's Serious area plan obligation but evaluate
the submission in light of the section 189(d) attainment date.
A. Emissions Inventories
1. Statutory and Regulatory Requirements
CAA section 172(c)(3) requires that each SIP include a
comprehensive, accurate, current inventory of actual emissions from all
sources of the relevant pollutant or pollutants in the nonattainment
area. The EPA discussed the emissions inventory requirements that apply
to PM<INF>2.5</INF> nonattainment areas in the PM<INF>2.5</INF> SIP
Requirements Rule and codified these requirements in 40 CFR
51.1008.\67\ The EPA has also issued guidance concerning emissions
inventories for PM<INF>2.5</INF> nonattainment areas.\68\
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\67\ 81 FR 58010, 58098-58099.
\68\ ``Emissions Inventory Guidance for Implementation of Ozone
and Particulate Matter National Ambient Air Quality Standards
(NAAQS) and Regional Haze Regulations,'' U.S. EPA, May 2017
(``Emissions Inventory Guidance''), available at <a href="https://www.epa.gov/air-emissions-inventories/air-emissions-inventory-guidance-implementation-ozone-and-particulate">https://www.epa.gov/air-emissions-inventories/air-emissions-inventory-guidance-implementation-ozone-and-particulate</a>.
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The base year emissions inventory for a Serious area attainment
plan or a CAA section 189(d) plan must provide a state's best estimate
of actual emissions from all sources of the relevant pollutants in the
area, i.e., all emissions that contribute to the formation of a
particular NAAQS pollutant. For the PM<INF>2.5</INF> NAAQS, the base
year inventory must include direct PM<INF>2.5</INF> emissions,
separately reported filterable and condensable PM<INF>2.5</INF>
emissions,\69\ and emissions of all chemical precursors to the
formation of secondary PM<INF>2.5</INF>, i.e., nitrogen oxides
(NO<INF>X</INF>), sulfur dioxide (SO<INF>2</INF>), volatile organic
compounds (VOC), and ammonia.\70\
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\69\ The Emissions Inventory Guidance identifies the types of
sources for which the EPA expects states to provide condensable PM
emissions inventories. Emissions Inventory Guidance, Section 4.2.1
(``Condensable PM Emissions''), pp. 63-65.
\70\ 40 CFR 51.1008(b)(1) and (c)(1).
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The emissions inventory base year for a Serious area attainment
plan must be one of the three years for which monitoring data were used
to reclassify the area to Serious, or another technically appropriate
year justified by the state in its Serious area SIP submission.\71\ The
emissions inventory base year for a Serious PM<INF>2.5</INF>
nonattainment area subject to CAA section 189(d) must be one of the
three years for which the EPA used monitored data to determine that the
area failed to attain the PM<INF>2.5</INF> NAAQS by the applicable
Serious area attainment date, or another technically appropriate year
justified by the state in its Serious area SIP submission.\72\
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\71\ 40 CFR 51.1008(b)(1).
\72\ 40 CFR 51.1008(c)(1).
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A state's SIP submission must include documentation explaining how
it calculated emissions data for the inventory. In estimating mobile
source emissions, a state should use the latest emissions models and
planning assumptions available at the time the SIP is developed.
In addition to the base year inventory submitted to meet the
requirements of CAA section 172(c)(3), the state must also submit a
projected attainment year inventory and emissions projections for each
RFP milestone year.\73\ These future emissions projections are
necessary components of the attainment demonstrations required under
CAA sections 189(b)(1) and 189(d) and the demonstration of RFP required
under section 172(c)(2).\74\ Emissions projections for future years
(referred to in the Plan as ``forecasted inventories'') should account
for, among other things, the ongoing effects of economic growth and
adopted emissions control requirements. The state's SIP submission
should include documentation to explain how the state calculated the
emissions projections. Where a state chooses to allow new major
stationary sources or major modifications to use emissions reduction
credits (ERCs) that were generated through shutdown or curtailed
emissions units occuring before the base year of an attainment plan,
the projected emissions inventory used to develop the attainment
demonstration must explicitly include the emissions from such
previously shutdown or curtailed emissions units.\75\
---------------------------------------------------------------------------
\73\ 40 CFR 51.1008 and 51.1012. See also Emissions Inventory
Guidance, Section 3 (``SIP Inventory Requirements and
Recommendations'').
\74\ 40 CFR 51.1004, 51.1008, 51.1011, and 51.1012.
\75\ 40 CFR 51.165(a)(3)(ii)(C)(1).
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2. Summary of the State's Submission
The State included summaries of the planning emissions inventories
for direct PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors
(NO<INF>X</INF>, SO<INF>X</INF>,\76\ VOC,\77\ and ammonia) and the
documentation for the inventories for the San Joaquin Valley
PM<INF>2.5</INF> nonattainment area in Appendix B (``Emissions
Inventory'') and Appendix I (``New Source Review and Emission Reduction
Credits'') of the 2018 PM<INF>2.5</INF> Plan. In addition, Appendix J
(``Modeling Emission Inventory'') of the 2018 PM<INF>2.5</INF> Plan
contains inventory documentation specific to the air quality modeling
inventories.
---------------------------------------------------------------------------
\76\ The SJV PM<INF>2.5</INF> Plan generally uses ``sulfur
oxides'' or ``SO<INF>X</INF>'' in reference to SO<INF>2</INF> as a
precursor to the formation of PM<INF>2.5</INF>. We use
SO<INF>X</INF> and SO<INF>2</INF> interchangeably throughout this
document.
\77\ The SJV PM<INF>2.5</INF> Plan generally uses ``reactive
organic gasses'' or ``ROG'' in reference to VOC as a precursor to
the formation of PM<INF>2.5</INF>. We use ROG and VOC
interchangeably throughout this document.
---------------------------------------------------------------------------
CARB and District staff worked together to develop the emissions
inventories for the San Joaquin Valley PM<INF>2.5</INF> nonattainment
area. The District worked with operators of the stationary facilities
in the nonattainment area to develop the stationary source emissions
estimates. The responsibility for developing emissions estimates for
area sources such as agricultural burning and paved road dust was
shared by the District and CARB. CARB staff developed the emissions
inventories for both on-road and non-road mobile sources.\78\
---------------------------------------------------------------------------
\78\ The EPA regulations refer to ``non-road'' vehicles and
engines whereas CARB regulations refer to ``Other Mobile Sources''
or ``off-road'' vehicles and engines. These terms refer to the same
types of vehicles and engines. We refer herein to such vehicles and
engines as ``non-road'' sources.
---------------------------------------------------------------------------
The SJV PM<INF>2.5</INF> Plan includes winter (24-hour) average and
annual average daily emissions inventories for the 2013 base year,
which CARB derived from the 2012 emissions inventory, and
[[Page 45283]]
estimated emissions for forecasted years from 2017 through 2028, as
developed as part of the 2018 PM<INF>2.5</INF> Plan for the attainment
and RFP demonstrations for the 1997, 2006, and 2012 PM<INF>2.5</INF>
NAAQS.\79\ In this proposal, we are evaluating those winter average and
annual average emissions inventories necessary to support the Serious
area and CAA section 189(d) nonattainment plans for the 1997 annual
PM<INF>2.5</INF> NAAQS, i.e., the 2013 base year inventory, forecasted
inventories for the RFP milestone years of 2017, 2020, 2023 (attainment
year), and 2026 (post-attainment milestone year), and additional
forecasted emissions inventories for 2018, 2019, 2021, and 2022 to
support the five percent annual emissions reduction demonstration as
required by CAA section 189(d). Each inventory includes emissions from
stationary, area, on-road, and non-road sources.
---------------------------------------------------------------------------
\79\ 2018 PM<INF>2.5</INF> Plan, Appendix B, pp. B-18 to B-19.
The winter average daily planning inventory corresponds to the
months of November through April, when daily ambient
PM<INF>2.5</INF> concentrations are typically highest. The base year
inventory is from the California Emissions Inventory Development and
Reporting System and future year inventories were estimated using
the California Emission Projection Analysis Model (CEPAM), 2016 SIP
Baseline Emission Projections, version 1.05.
---------------------------------------------------------------------------
The State selected 2013 for the base year emissions inventory,
building on the 2012 actual emissions inventory and considering
available air quality data, trends, and field studies.\80\
Specifically, the State worked with local air districts and selected
2012 for the actual emissions inventory as it aligned with the 2012
data collection year of the Multiple Air Toxics Exposure Study IV
(MATES IV) \81\ of the South Coast Air Quality Management District
(SCAQMD) and to maintain consistency across various California air
quality plans.\82\ The State then projected the 2013 base year
emissions inventory (also referred to as the planning emissions
inventory), presented in Appendix B of the 2018 PM<INF>2.5</INF> Plan,
from that 2012 actual emissions inventory. The State developed the
modeling emissions inventory from the base year emissions inventory,
and conducted its base case modeling using 2013 for several reasons:
Analysis of air quality trends, adjusted for meteorology, that
indicated 2013 as a year conducive to ozone and PM<INF>2.5</INF>
formation; availability of research-grade measurements of two
significant pollution episodes in the DISCOVER-AQ field study of
January to February 2013; and the relatively high design values for
2013, making it a conservative choice for attainment modeling.\83\
---------------------------------------------------------------------------
\80\ 2018 PM<INF>2.5</INF> Plan, Appendix L, pp. 11-12.
\81\ Additional information on the MATES IV study performed in
2012 is available at: <a href="https://www.aqmd.gov/home/air-quality/air-quality-studies/health-studies/mates-iv">https://www.aqmd.gov/home/air-quality/air-quality-studies/health-studies/mates-iv</a>. SCAQMD performed the
subsequent MATES V study in 2018 and issued the MATES V final report
in August 2021. See <a href="https://www.aqmd.gov/home/air-quality/air-quality-studies/health-studies/mates-v">https://www.aqmd.gov/home/air-quality/air-quality-studies/health-studies/mates-v</a>, and ``MATES V, Multiple Air
Toxics Exposure Study in the South Coast AQMD, Final Report,''
SCAQMD, August 2021.
\82\ 2018 PM<INF>2.5</INF> Plan, Appendix B, p. B-18
\83\ 2018 PM<INF>2.5</INF> Plan, Appendix L, p. 12. The State
presents further information in the ``APPENDIX: San Joaquin Valley
PM<INF>2.5</INF> SIP (2018)'' of Appendix L and highlights that 2013
was one of the worst years in the decade preceding 2018 for
PM<INF>2.5</INF> pollution in the San Joaquin Valley, underscoring
its use as a conservative base year for attainment modeling.
---------------------------------------------------------------------------
CARB developed the base year inventories for stationary sources
using actual emissions reports from facility operators. The State
developed the base year emissions inventory for area sources using the
most recent models and methodologies available at the time the State
was developing the 2018 PM<INF>2.5</INF> Plan.\84\ The Plan also
includes background, methodology, and inventories of condensable and
filterable PM<INF>2.5</INF> emissions from stationary point and non-
point combustion sources that are expected to generate condensable
PM<INF>2.5</INF>.\85\
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\84\ 2018 PM<INF>2.5</INF> Plan, Appendix B, Section B.2
(``Emissions Inventory Summary and Methodology'').
\85\ Id. at B-42 to B-44.
---------------------------------------------------------------------------
CARB used EMFAC2014 to estimate on-road motor vehicle emissions
based on transportation activity data from the 2017 Transportation
Improvement Plan (2017 TIP) adopted by the transportation planning
agencies in the San Joaquin Valley.\86\ EMFAC2014 was the latest EPA-
approved version of California's mobile source emission factor model
for estimating tailpipe, brake, and tire wear emissions from on-road
mobile sources that was available during the State's and District's
development of the emissions inventories in the 2018 PM<INF>2.5</INF>
Plan.\87\ Re-entrained paved road dust emissions were calculated using
a CARB methodology consistent with the EPA's AP-42 road dust
methodology.\88\ CARB also provided emissions inventories for non-road
equipment, including aircraft, trains, recreational boats, construction
equipment, and farming equipment, among others. CARB uses a suite of
category-specific models to estimate non-road emissions for many
categories and, where a new model was not available, used the
OFFROAD2007 model.\89\
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\86\ 2018 PM<INF>2.5</INF> Plan, Appendix D, p. D-123.
\87\ 80 FR 77337 (December 14, 2015). EMFAC is short for
Emission FACtor. The EPA announced the availability of the EMFAC2014
model, effective on the date of publication in the Federal Register,
for use in state implementation plan development and transportation
conformity in California. Upon that action, EMFAC2014 was required
to be used for all new regional emissions analyses and CO,
PM<INF>10</INF>, and PM<INF>2.5</INF> hot-spot analyses that were
started on or after December 14, 2017, which was the end of the
grace period for using the prior mobile source emissions model,
EMFAC2011. On August 15, 2019, the EPA approved EMFAC2017, a
revision to the mobile source emissions model (84 FR 41717). The
grace period for new regional emissions analyses began on August 15,
2019, and ended on August 16, 2021, while the grace period for hot-
spot analyses began on August 15, 2019, and ended on August 17,
2020. Id. at 41720. On November 15, 2022, the EPA approved
EMFAC2021, a subsequent revision to the mobile source emissions
model (87 FR 68483). The grace period for new regional emissions
analyses began on November 15, 2022, and ends on November 15, 2024,
while the grace period for hot-spot analyses began on November 15,
2022, and ends on November 15, 2023. Id. at 68487-68488.
\88\ 2018 PM<INF>2.5</INF> Plan, Appendix B, p. B-28. AP-42 has
been published since 1972 as the primary source of the EPA's
emission factor information and is available at <a href="https://www.epa.gov/air-emissions-factors-and-quantification/ap-42-compilation-air-emissions-factors">https://www.epa.gov/air-emissions-factors-and-quantification/ap-42-compilation-air-emissions-factors</a>. It contains emission factors and process
information for more than 200 air pollution source categories. A
source category is a specific industry sector or group of similar
emitting sources. The emission factors have been developed and
compiled from source test data, material balance studies, and
engineering estimates. The EPA released an update to AP-42 in
January 2011 that revised the equation for estimating paved road
dust emissions based on an updated data regression that included new
emissions tests results. 76 FR 6328 (February 4, 2011). CARB used
the revised 2011 AP-42 methodology in developing on-road mobile
source emissions; see <a href="https://www.arb.ca.gov/ei/areasrc/fullpdf/full7-9_2016.pdf">https://www.arb.ca.gov/ei/areasrc/fullpdf/full7-9_2016.pdf</a>.
\89\ 2018 PM<INF>2.5</INF> Plan, Appendix B, pp. B-38 through B-
40. The EPA regulations refer to ``non-road'' vehicles and engines
whereas CARB regulations refer to ``Other Mobile Sources'' or ``off-
road'' vehicles and engines. These terms refer to the same types of
vehicles and engines. We refer herein to such vehicles and engines
as ``non-road'' sources.
---------------------------------------------------------------------------
CARB developed the emissions forecasts by applying growth and
control profiles to the base year inventory. CARB's mobile source
emissions projections take into account predicted activity rates and
vehicle fleet turnover by vehicle model year and adopted controls.\90\
In addition, the Plan states that the District is providing for use of
pre-base year ERCs as offsets by accounting for such ERCs in the
projected 2025 emissions inventory.\91\ The 2018 PM<INF>2.5</INF> Plan
identifies growth factors, control factors, and estimated offset use
between 2013 and 2025 for direct PM<INF>2.5</INF>, NO<INF>X</INF>,
SO<INF>X</INF>, and VOC emissions by source category and lists all pre-
base year ERCs issued by the District for PM<INF>10</INF>,
NO<INF>X</INF>, SO<INF>X</INF>, and VOC emissions, by facility.\92\
---------------------------------------------------------------------------
\90\ Id. at B-18 and B-19.
\91\ 2018 PM<INF>2.5</INF> Plan, Appendix I, pp. I-1 to I-5.
\92\ Id. at tables I-1 to I-5.
---------------------------------------------------------------------------
Table 1 provides a summary of the winter (24-hour) average
inventories in tons per day (tpd) of direct PM<INF>2.5</INF> and
PM<INF>2.5</INF> precursors for the 2013 base year. Table 2 provides a
summary of annual
[[Page 45284]]
average inventories of direct PM<INF>2.5</INF> and PM<INF>2.5</INF>
precursors for the 2013 base year. For the purposes of this proposal,
these annual average inventories provide the bases for our evaluation
of the precursor demonstration, control measure analysis, attainment
demonstration, RFP demonstration, and the motor vehicle emission
budgets (``budgets'') in the SJV PM<INF>2.5</INF> Plan with respect to
the Serious area and CAA section 189(d) requirements for the 1997
annual PM<INF>2.5</INF> NAAQS.
Table 1--San Joaquin Valley Winter Average Emissions Inventory for Direct PM2.5 and PM2.5 Precursors for the
2013 Base Year
[tpd]
----------------------------------------------------------------------------------------------------------------
Direct PM2.5
Category NOX SOX VOC Ammonia
----------------------------------------------------------------------------------------------------------------
Stationary Sources.............. 8.5 35.0 6.9 86.6 13.9
Area Sources.................... 41.4 11.5 0.5 156.8 291.5
On-Road Mobile Sources.......... 6.4 188.7 0.6 51.1 4.4
Non-Road Mobile Sources......... 4.4 65.3 0.3 27.4 0.0
-------------------------------------------------------------------------------
Totals \a\.................. 60.8 300.5 8.4 321.9 309.8
----------------------------------------------------------------------------------------------------------------
Source: 2018 PM2.5 Plan, Appendix B, tables B-1 to B-5.
\a\ Totals reflect disaggregated emissions and may not add exactly as shown here due to rounding.
Table 2--San Joaquin Valley Annual Average Emissions Inventory for Direct PM2.5 and PM2.5 Precursors for the
2013 Base Year
[tpd]
----------------------------------------------------------------------------------------------------------------
Direct PM2.5
Category NOX SOX VOC Ammonia
----------------------------------------------------------------------------------------------------------------
Stationary Sources.............. 8.8 38.6 7.2 87.1 13.9
Area Sources.................... 41.5 8.1 0.3 153.4 310.9
On-Road Mobile Sources.......... 6.4 183.1 0.6 49.8 4.4
Non-Road Mobile Sources......... 5.8 87.4 0.3 33.8 0.0
-------------------------------------------------------------------------------
Totals \a\.................. 62.5 317.2 8.5 324.1 329.2
----------------------------------------------------------------------------------------------------------------
Source: 2018 PM2.5 Plan, Appendix B, tables B-1 to B-5.
\a\ Totals reflect disaggregated emissions and may not add exactly as shown here due to rounding.
CARB explains in its August 2021 Staff Report that although it has
updated the emissions inventories since development of the 2018
PM<INF>2.5</INF> Plan, the 15 [micro]g/m\3\ SIP Revision ``uses the
same inventory as the one in the 2018 PM<INF>2.5</INF> Plan, which it
amends, for consistency.'' To support this approach, CARB included in
its August 2021 Staff Report comparisons between the estimated annual
NO<INF>X</INF> and PM<INF>2.5</INF> emissions in the 2013 base year
inventory developed using EMFAC2014 with those developed using the more
recent EPA-approved version of EMFAC, EMFAC2017. CARB subsequently
provided similar comparisons for the 2020 RFP and 2023 attainment
years, as well as comparisons with emissions derived using
EMFAC2021.\93\ Table 3 shows the comparisons between on-road mobile
source emissions derived using EMFAC2014, EMFAC2017, and EMFAC2021 for
NO<INF>X</INF> and PM<INF>2.5</INF> in 2013, 2020, and 2023.
---------------------------------------------------------------------------
\93\ Email dated March 29, 2022, from Nesamani Kalandiyur, CARB,
to Karina O'Connor et al., EPA Region IX, Subject: ``RE: EMFAC
Discussion,'' (``March 2022 EMFAC Clarification''). The email also
includes model results for the 2026 post-attainment milestone year.
CARB initially released EMFAC2021 v1.0.0 on January 15, 2021. CARB
released an updated version, EMFAC2021 v1.0.1, on April 30, 2021,
and the EPA approved the use of EMFAC2021 for use in SIP development
on November 15, 2022 (87 FR 68483).
Table 3--On-Road Mobile Source NOX and Direct PM2.5 Emissions Derived Using EMFAC2014, EMFAC2017, and EMFAC2021
[tpd]
--------------------------------------------------------------------------------------------------------------------------------------------------------
NOX Direct PM2.5
-----------------------------------------------------------------------------------------------
2013 2020 2023 2013 2020 2023
--------------------------------------------------------------------------------------------------------------------------------------------------------
EMFAC2014............................................... 183.1 96.9 57.9 6.5 3.4 3.2
EMFAC2017............................................... 170.0 89.3 61.2 6.8 4.0 3.3
EMFAC2021............................................... 193.5 84.4 54.9 6.1 2.3 1.8
EMFAC2017/EMFAC2014..................................... 93% 92% 106% 106% 116% 105%
EMFAC2021/EMFAC2014..................................... 106% 87% 95% 95% 66% 56%
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: CARB's March 2022 EMFAC Clarification.
CARB determined that PM<INF>2.5</INF> emissions estimates for 2013
derived using EMFAC2017 are approximately six percent higher than
estimates derived using EMFAC2014, and that NO<INF>X</INF> emissions
estimates for 2013
[[Page 45285]]
derived using EMFAC2017 are seven percent lower than the emissions
estimates derived using EMFAC2014. On-road PM<INF>2.5</INF> and
NO<INF>X</INF> estimates derived using EMFAC2021 are five percent lower
and six percent higher, respectively, in 2013 as compared with
estimates from EMFAC2014. In the 2023 attainment year, on-road
PM<INF>2.5</INF> and NO<INF>X</INF> emissions estimates derived using
EMFAC2017 are approximately 5 percent and 6 percent higher,
respectively, than estimates derived using EMFAC2014, whereas on-road
PM<INF>2.5</INF> and NO<INF>X</INF> emissions estimates derived using
EMFAC2021 are approximately 44 percent and 5 percent lower,
respectively, than in EMFAC2014.
Based on these model results, CARB concludes that the differences
in emissions derived using the different EMFAC model versions are not
significant enough to affect the modeled attainment demonstration in
the 15 [micro]g/m\3\ SIP Revision.
3. The EPA's Review of the State's Submission
As part of our July 22, 2021 proposed and November 26, 2021 final
rules,\94\ we reviewed the emissions inventories in the 2018
PM<INF>2.5</INF> Plan that pertain to the 1997 annual PM<INF>2.5</INF>
NAAQS and the emissions inventory estimation methodologies used by
California for consistency with CAA requirements and the EPA's
guidance. We found that the inventories were based on the most current
and accurate information available to the State and District at the
time they were developing the 2018 PM<INF>2.5</INF> Plan and
inventories, including the latest version of California's mobile source
emissions model that had been approved by the EPA at the time,
EMFAC2014. We also found that the inventories comprehensively address
all source categories in the San Joaquin Valley PM<INF>2.5</INF>
nonattainment area and are consistent with the EPA's inventory
guidance. In our November 26, 2021 final action, we approved the 2013
base year emissions inventories in the 2018 PM<INF>2.5</INF> Plan as
meeting the requirements of CAA section 172(c)(3) and 40 CFR 51.1008
for purposes of both the Serious area and the CAA section 189(d)
attainment plans for the 1997 annual PM<INF>2.5</INF> NAAQS.\95\
---------------------------------------------------------------------------
\94\ 86 FR 38652 and 86 FR 67329.
\95\ 86 FR 67329, 67341.
---------------------------------------------------------------------------
For purposes of evaluating the 15 [micro]g/m\3\ SIP Revision, we
have reviewed the additional information comparing the emissions
derived using EMFAC2014, EMFAC2017, and EMFAC2021 that was provided by
CARB in its August 2021 Staff Report and subsequent email transmittal.
The State modeled reductions of direct PM<INF>2.5</INF> and
NO<INF>X</INF> on-road mobile emissions and calculated the sensitivity
of the PM<INF>2.5</INF> design value per tpd of emissions.\96\ The EPA
used those sensitivity results with the EMFAC emissions estimates to
assess the effects of the various EMFAC model version results on the
attainment demonstration in the Plan. We are proposing to find that
although NO<INF>X</INF> and PM<INF>2.5</INF> emissions estimates in the
2023 attainment year are slightly higher in EMFAC2017 than in
EMFAC2014, the effect on PM<INF>2.5</INF> concentrations is small
enough that the attainment demonstration in the 15 [micro]g/m\3\ SIP
Revision remains valid.\97\ Furthermore, more up-to-date emissions
information from EMFAC2021 indicates lower emissions of NO<INF>X</INF>
and PM<INF>2.5</INF> in the attainment year, indicating that the
attainment modeling results derived using EMFAC2014 are conservative
and that the 2023 attainment year design values are expected to be
lower than those modeled in the Plan.
---------------------------------------------------------------------------
\96\ 15 [micro]g/m\3\ SIP Revision, Appendix D, p. D-125.
Transportation Conformity Budgets, Emissions Trading Mechanism,
Table 21. These sensitivity simulations used the same modeling base
case as the attainment demonstration for the 15 [micro]g/m\3\ SIP
Revision.
\97\ Spreadsheet ``EMFAC update effect on annual 1997
PM<INF>2.5</INF> NAAQS attainment demonstration,'' EPA Region IX,
May 1, 2023.
---------------------------------------------------------------------------
With respect to future year emissions projections in the 15
[micro]g/m\3\ SIP Revision, we have reviewed the growth and control
factors and are proposing to find them acceptable and thus conclude
that the future baseline emissions projections in the SJV
PM<INF>2.5</INF> Plan, which reflect ongoing emissions reductions from
existing (i.e., ``baseline'') control measures as discussed in Section
IV.C.2.a, reflect appropriate calculation methods and the latest
planning assumptions. Also, as a general matter, the EPA will approve a
SIP submission that takes emissions reduction credit for a control
measure only where the EPA has approved the measure as part of the SIP.
Thus, for example, to take credit for the emissions reductions from
newly adopted or amended District rules for stationary sources, the
related rules must be approved by the EPA into the SIP. Table 2 of the
EPA's ``Technical Support Document, San Joaquin Valley PM<INF>2.5</INF>
Plan Revision for the 1997 Annual PM<INF>2.5</INF> NAAQS,'' April 2023
(``EPA's 1997 Annual PM<INF>2.5</INF> TSD'') shows District rules with
post-2013 compliance dates that are reflected in the future year
baseline inventories, along with information on the EPA's approval of
these rules, and shows that stationary source emissions reductions
assumed by the SJV PM<INF>2.5</INF> Plan for future years are supported
by rules approved as part of the California SIP for the San Joaquin
Valley. With respect to mobile sources, the EPA has taken action in
recent years to approve CARB mobile source regulations into the state-
wide portion of the California SIP. We therefore find that the future
year baseline projections in the SJV PM<INF>2.5</INF> Plan are properly
supported by SIP-approved stationary and mobile source measures.
For these reasons, we are proposing to find that the 2013 base year
emissions inventories in the SJV PM<INF>2.5</INF> Plan for the 1997
annual PM<INF>2.5</INF> NAAQS continue to satisfy the requirements of
CAA section 172(c)(3) and 40 CFR 51.1008 for purposes of both the
Serious area and the CAA section 189(d) attainment plans. We are also
proposing to find that the forecasted inventories in the Plan for the
years 2017, 2018, 2019, 2020, 2023, and 2026 provide an adequate basis
for the BACM, RFP, and the modeled attainment demonstration analyses in
the SJV PM<INF>2.5</INF> Plan.
B. PM2.5 Precursors
1. Statutory and Regulatory Requirements
Under subpart 4 of part D, title I of the CAA and the
PM<INF>2.5</INF> SIP Requirements Rule, each state containing a
PM<INF>2.5</INF> nonattainment area must evaluate all PM<INF>2.5</INF>
precursors for regulation unless, for any given PM<INF>2.5</INF>
precursor, the state demonstrates to the Administrator's satisfaction
that such precursor does not contribute significantly to
PM<INF>2.5</INF> levels that exceed the NAAQS in the nonattainment
area.\98\ The provisions of subpart 4 do not define the term
``precursor'' for purposes of PM<INF>2.5</INF>, nor do they explicitly
require the control of any specifically identified PM precursor. The
statutory definition of ``air pollutant,'' in CAA section 302(g),
however, provides that the term ``includes any precursors to the
formation of any air pollutant, to the extent the Administrator has
identified such precursor or precursors for the particular purpose for
which the term `air pollutant' is used.'' \99\ The EPA has identified
NO<INF>X</INF>, SO<INF>2</INF>, VOC, and ammonia as precursors to the
formation of PM<INF>2.5</INF>.\100\ Accordingly, the attainment plan
requirements of subpart 4 apply to emissions of all four precursor
pollutants and direct PM<INF>2.5</INF> from all types of stationary,
area, and mobile
[[Page 45286]]
sources, except as otherwise provided in the Act (e.g., in CAA section
189(e)).
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\98\ 81 FR 58010, 58017-58020.
\99\ CAA section 302(g).
\100\ 81 FR 58010, 58015.
---------------------------------------------------------------------------
Section 189(e) of the Act requires that the control requirements
for major stationary sources of direct PM<INF>10</INF> (which includes
PM<INF>2.5</INF>) also apply to major stationary sources of
PM<INF>10</INF> precursors, except where the Administrator determines
that such sources do not contribute significantly to PM<INF>10</INF>
levels that exceed the standard in the area. Section 189(e) contains
the only express exception to the control requirements under subpart 4
(e.g., requirements for RACM, RACT, BACM, BACT, MSM, and nonattainment
new source review (NSR)). Although section 189(e) explicitly addresses
only major stationary sources, the EPA interprets the Act as
authorizing it also to determine, under appropriate circumstances, that
regulation of specific PM<INF>2.5</INF> precursors from other source
categories in a given nonattainment area is not necessary.\101\ For
example, under the EPA's longstanding interpretation of the control
requirements that apply to stationary and mobile sources of
PM<INF>10</INF> precursors in nonattainment areas under CAA section
172(c)(1) and subpart 4,\102\ a state may demonstrate in a SIP
submission that control of a certain precursor pollutant is not
necessary because it does not contribute significantly to ambient
PM<INF>10</INF> levels in the nonattainment area and is not needed for
attainment.\103\
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\101\ Id. at 58018-58019.
\102\ General Preamble, 13539-13542.
\103\ Courts have upheld this approach to the requirements of
subpart 4 for PM<INF>10</INF>. See, e.g., Assoc. of Irritated
Residents v. EPA, et al., 423 F.3d 989 (9th Cir. 2005).
---------------------------------------------------------------------------
Under the PM<INF>2.5</INF> SIP Requirements Rule, a state may elect
to submit to the EPA a ``comprehensive precursor demonstration'' for a
specific nonattainment area to show that emissions of a particular
precursor from all existing sources located in the nonattainment area
do not contribute significantly to PM<INF>2.5</INF> levels that exceed
the standard in the area.\104\ If the EPA determines that the
contribution of the precursor to PM<INF>2.5</INF> levels in the area is
not significant and approves the demonstration, the state is not
required to control emissions of the relevant precursor from existing
sources in the attainment plan.\105\
---------------------------------------------------------------------------
\104\ 40 CFR 51.1006(a)(1).
\105\ Id. A state may also perform a separate, ``NNSR precursor
demonstration'' to evaluate the sensitivity of PM<INF>2.5</INF>
levels in the nonattainment area to an increase in emissions of a
particular precursor and determine if new major stationary sources
and major modifications of a precursor would contribute
significantly to PM<INF>2.5</INF> levels that exceed the standard in
the nonattainment area. 40 CFR 51.1006(a)(3).
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In addition, in May 2019, the EPA issued the ``PM<INF>2.5</INF>
Precursor Demonstration Guidance'' (``PM<INF>2.5</INF> Precursor
Guidance''),\106\ which provides recommendations to states for
analyzing nonattainment area PM<INF>2.5</INF> emissions and developing
such optional precursor demonstrations, consistent with the
PM<INF>2.5</INF> SIP Requirements Rule. The EPA developed recommended
contribution thresholds to help assess whether a precursor
significantly contributes to PM<INF>2.5</INF> levels above the NAAQS.
The thresholds are based on the size of PM<INF>2.5</INF> concentration
increases that are statistically indistinguishable from the inherent
variability in the measured atmospheric concentrations.\107\ If the
chemical component of PM<INF>2.5</INF> ambient concentrations
corresponding to emissions of a precursor (e.g., the concentration of
sulfate, which corresponds to SO<INF>2</INF> emissions) is below the
threshold, that is evidence that the precursor does not significantly
contribute. If the precursor is above the threshold in this
concentration-based test, the State can use a sensitivity-based test,
in which the modeled sensitivity or response of ambient
PM<INF>2.5</INF> concentrations to changes in emissions of the
precursor is estimated and then compared to the threshold. The EPA's
recommended annual average contribution threshold for purposes of the
2012 annual PM<INF>2.5</INF> NAAQS is 0.2 [micro]g/m\3\.\108\ The
PM<INF>2.5</INF> Precursor Guidance explains that this threshold
represents a percentage of the 2012 annual NAAQS and that ``[d]ifferent
thresholds may be applicable to other levels and/or forms of the NAAQS
(either past or future).'' \109\ In addition to comparing the
concentration or modeled response to the threshold, the State can
consider other information in assessing whether the precursor
significantly contributes.
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\106\ ``PM<INF>2.5</INF> Precursor Demonstration Guidance,''
EPA-454/R-19-004, May 2019, including memorandum dated May 30, 2019,
from Scott Mathias, Acting Director, Air Quality Policy Division and
Richard Wayland, Director, Air Quality Assessment Division, Office
of Air Quality Planning and Standards (OAQPS), EPA to Regional Air
Division Directors, Regions 1-10, EPA. The PM<INF>2.5</INF>
Precursor Guidance builds upon the draft version of the guidance,
released on November 17, 2016 (``Draft PM<INF>2.5</INF> Precursor
Guidance''), which CARB referenced in developing its precursor
demonstration in the SJV PM<INF>2.5</INF> Plan. ``PM<INF>2.5</INF>
Precursor Demonstration Guidance, Draft for Public Review and
Comments,'' EPA-454/P-16-001, November 17, 2016, including
memorandum dated November 17, 2016, from Stephen D. Page, Director,
OAQPS, EPA to Regional Air Division Directors, Regions 1-10, EPA.
\107\ PM<INF>2.5</INF> Precursor Guidance, p. 15.
\108\ Id. at 17.
\109\ Id. at fn. 20.
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As explained in the PM<INF>2.5</INF> Precursor Guidance, and
consistent with the PM<INF>2.5</INF> SIP Requirements Rule (40 CFR
51.1010(a)(2)(ii), 51.1006(a)(1)(ii)), the EPA may require an air
agency to identify and evaluate potential control measures for a
precursor to determine the potential emissions reductions achievable,
in support of a precursor demonstration that relies on a sensitivity
analysis.\110\ The guidance states that such evaluation is particularly
important for an area in which the PM<INF>2.5</INF> response to a 30
percent reduction in precursor emissions is close to the contribution
threshold. In the case of a nonattainment area classified as Serious,
this analysis would include identification and evaluation of measures
that would constitute BACM/BACT level control for such pollutant.\111\
Consistent with these regulations, the EPA requested that the State
identify and evaluate potential control measures for ammonia to
determine the potential emissions reductions achievable for purposes of
the 1997 annual PM<INF>2.5</INF> NAAQS.
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\110\ Id. at 31.
\111\ Id.
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We are evaluating the SJV PM<INF>2.5</INF> Plan in accordance with
the presumption embodied within subpart 4, that states must address all
PM<INF>2.5</INF> precursors in the evaluation of potential control
measures unless the state adequately demonstrates that emissions of a
particular precursor or precursors do not contribute significantly to
ambient PM<INF>2.5</INF> levels that exceed the PM<INF>2.5</INF> NAAQS
in the nonattainment area. In reviewing any determination by a state to
exclude a PM<INF>2.5</INF> precursor from the required evaluation of
potential control measures, we consider both the magnitude of the
precursor's contribution to ambient PM<INF>2.5</INF> concentrations in
the nonattainment area and, where the state has conducted sensitivity-
based analyses, the sensitivity of ambient PM<INF>2.5</INF>
concentrations in the area to reductions in emissions of that precursor
in accordance with the PM<INF>2.5</INF> Precursor Guidance.
2. Summary of the State's Submission
The State presents some results and conclusions from its
PM<INF>2.5</INF> precursor sensitivity analysis in Chapter 5
(``Demonstration of Federal Requirements for 1997 PM<INF>2.5</INF>
Standards''), Section 5.3.1 (``Summary of Modeling Results'') of the 15
[micro]g/m\3\ SIP Revision, and presents the full
[[Page 45287]]
precursor demonstration in Appendix G (``Precursor Demonstration'') of
the 2018 PM<INF>2.5</INF> Plan.\112\ CARB presents additional modeling
results in Appendix K (``Modeling Attainment Demonstration'') of the 15
[micro]g/m\3\ SIP Revision. CARB also provided clarifying information
on its precursor assessment, including an Attachment A to its letter
transmitting the 2018 PM<INF>2.5</INF> Plan to the EPA \113\ and
further clarifications in five email transmittals.\114\ CARB's December
2018 Staff Report and August 2021 Staff Report contain additional
discussion of the role of ammonia in the formation of ammonium nitrate
and the role of VOC in the formation of ammonium nitrate and secondary
organic aerosol.\115\ Lastly, on March 30, 2023, CARB transmitted to
the EPA a technical supplement titled ``Ammonia: Supplemental
Information for EPA in Support of 15 [micro]g/m\3\ Annual
PM<INF>2.5</INF> Standard, March 2023'' (``March 2023 Ammonia
Supplement'') in which CARB and the District ``clarify CARB's
assessment of ammonia as a precursor to fine particulate matter
(PM<INF>2.5</INF>) for the 15 [micro]g/m\3\ annual standard by
summarizing information previously submitted to EPA and providing new
detailed control measure analysis'' \116\ to assess potential ammonia
emissions reductions achievable in the San Joaquin Valley through the
implementation of best available controls.
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\112\ Appendix G was not changed relative to the 2018
PM<INF>2.5</INF> Plan for the 15 [micro]g/m\3\ SIP Revision.
\113\ Letter dated May 9, 2019, from Richard Corey, Executive
Officer, CARB, to Michael Stoker, Regional Administrator, EPA Region
9, Attachment A (``Clarifying information for the San Joaquin Valley
2018 Plan regarding model sensitivity related to ammonia and ammonia
controls'').
\114\ Email dated June 20, 2019, from Jeremy Avise, CARB, to
Scott Bohning, EPA Region IX, Subject: ``RE: SJV model disbenefit
from SO<INF>X</INF> reduction,'' with attachment (``CARB's June 2019
Precursor Clarification''); email dated September 19, 2019, from
Jeremy Avise, CARB, to Scott Bohning, EPA Region IX, Subject: ``FW:
SJV species responses,'' with attachments (``CARB's September 2019
Precursor Clarification''); email dated October 18, 2019, from Laura
Carr, CARB, to Scott Bohning, Jeanhee Hong, and Rory Mays, EPA
Region IX, Subject: ``Clarifying information on ammonia,'' with
attachment ``Clarifying Information on Ammonia'' (``CARB's October
2019 Precursor Clarification''); email dated April 19, 2021, from
Laura Carr, CARB, to Rory Mays, EPA Region IX, Subject: ``Ammonia
update,'' with attachment ``Update on Ammonia in the San Joaquin
Valley'' (``CARB's April 19, 2021 Precursor Clarification''); and
email dated April 26, 2021, from Laura Carr, CARB, to Scott Bohning,
EPA Region IX, Subject: ``RE: Ammonia update,'' with attachment
``Ammonia in San Joaquin Valley'' (``CARB's April 26, 2021 Precursor
Clarification'').
\115\ December 2018 Staff Report, Appendix C, pp. 9-16, and
August 2021 Staff Report, pp. 8-9 and Attachment 1. Attachment 1 is
identical to the attachment to CARB's April 19, 2021 Precursor
Clarification.
\116\ Letter dated March 29, 2023, from Steven S. Cliff,
Executive Officer, CARB, to Martha Guzman, Regional Administrator,
EPA Region 9, with enclosures.
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The SJV PM<INF>2.5</INF> Plan provides both concentration-based and
sensitivity-based analyses of precursor contributions to ambient
PM<INF>2.5</INF> concentrations in the San Joaquin Valley. For the
concentration-based analysis, CARB assessed the 2015 annual average
concentration of each precursor in ambient PM<INF>2.5</INF> at
Bakersfield, for which the necessary speciated PM<INF>2.5</INF> data
are available and where the highest PM<INF>2.5</INF> design values have
been recorded in most years. CARB concludes that the 2015 annual
average contributions of ammonia, SO<INF>X</INF>, and VOC are 5.2
[micro]g/m\3\, 1.6 [micro]g/m\3\, and 6.2 [micro]g/m\3\, respectively.
Given that these levels are above the EPA's recommended contribution
threshold, the State proceeded with a sensitivity-based analysis.
CARB's sensitivity-based analysis used the same Community
Multiscale Air Quality (CMAQ) modeling platform as that used for the
Plan's attainment demonstration, described in Section IV.D. of this
proposal. The State modeled the sensitivity of ambient PM<INF>2.5</INF>
concentration in the San Joaquin Valley to 30 percent and 70 percent
reductions in anthropogenic emissions of each precursor pollutant for
modeled years 2013, 2020, and 2024. The year 2013 is the 2018
PM<INF>2.5</INF> Plan's base year; 2020 is the modeled attainment year
for the 1997 24-hour PM<INF>2.5</INF> NAAQS and former modeled
attainment year for the 1997 annual PM<INF>2.5</INF> NAAQS; and 2024 is
the modeled attainment year for the 2006 24-hour PM<INF>2.5</INF>
NAAQS. For the 1997 annual PM<INF>2.5</INF> NAAQS, the revised modeled
attainment year is 2023, but the State did not conduct precursor
sensitivity modeling for that additional year. Instead, the State
assumed that 2023 and 2024 would have very similar results; \117\ and
results for 2024 were used as a proxy for those in 2023.
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\117\ 15 [micro]g/m\3\ SIP Revision, Chapter 5, p. 5-8, and
March 2023 Ammonia Supplement, fn. 35.
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In Appendix G of the 2018 PM<INF>2.5</INF> Plan, the State compared
its sensitivity modeling results to the recommended annual average
contribution threshold of 0.2 [micro]g/m\3\ in the PM<INF>2.5</INF>
Precursor Guidance. As discussed in Section IV.B.1, the 0.2 [micro]g/
m\3\ contribution threshold was derived based on the level of the 2012
annual PM<INF>2.5</INF> NAAQS (i.e., 12.0 [micro]g/m\3\). In the March
2023 Ammonia Supplement, the State explains that adjusting the
contribution threshold to the level of the 1997 annual PM<INF>2.5</INF>
NAAQS (i.e., 15.0 [micro]g/m\3\) results in a contribution threshold of
0.25 [micro]g/m\3\ and presents an updated evaluation of the modeled
concentration-based and sensitivity-based analyses for ammonia using
the 0.25 [micro]g/m\3\ threshold.\118\
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\118\ The State did not provide an updated analysis using the
0.25 [micro]g/m\3\ threshold for SO<INF>X</INF> or VOC.
---------------------------------------------------------------------------
In collaboration with the District, the State supplemented the
sensitivity analysis, particularly for ammonia, with consideration of
additional information such as emissions trends, the appropriateness of
future year versus base year sensitivity, the severity of
nonattainment, and a detailed controls analysis.\119\ These factors
were identified in the then-available Draft PM<INF>2.5</INF> Precursor
Guidance, as well as in the final PM<INF>2.5</INF> Precursor Guidance,
as factors that may be relevant to a sensitivity-based contribution
analysis.\120\
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\119\ 2018 PM<INF>2.5</INF> Plan, Appendix G, pp. 8-10, and
March 2023 Ammonia Supplement, pp. 13-96.
\120\ PM<INF>2.5</INF> Precursor Guidance, pp. 18-19
(consideration of additional information), p. 31 (available emission
controls), and pp. 35-36 (appropriateness of future year versus base
year sensitivity).
---------------------------------------------------------------------------
Taken together, these analyses led CARB to conclude that
NO<INF>X</INF> remains a plan precursor but that ammonia,
SO<INF>X</INF>, and VOC do not contribute significantly to ambient
PM<INF>2.5</INF> levels that exceed the PM<INF>2.5</INF> NAAQS in the
San Joaquin Valley. We summarize the State's analysis and conclusions
below. For a more detailed summary of the precursor demonstration in
the Plan, please refer to the EPA's ``Technical Support Document, EPA
Evaluation of PM<INF>2.5</INF> Precursor Demonstration, San Joaquin
Valley PM<INF>2.5</INF> Plan for the 2006 PM<INF>2.5</INF> NAAQS,''
February 2020 (``EPA's February 2020 Precursor TSD'').
a. Ammonia
For the ammonia analysis presented in Appendix G of the 2018
PM<INF>2.5</INF> Plan, the State compared the annual precursor
contributions to 0.2 [micro]g/m\3\, the contribution threshold
recommended for the 2012 annual PM<INF>2.5</INF> NAAQS in the
PM<INF>2.5</INF> Precursor Guidance. The State supplemented this
analysis in the March 2023 Ammonia Supplement by comparing the annual
ammonia contributions to the 0.25 [micro]g/m\3\ threshold it derived
for the 1997 annual PM<INF>2.5</INF> NAAQS. For a modeled 30 percent
ammonia emissions reduction, the ambient PM<INF>2.5</INF> responses in
2013 ranged from 0.20 to 0.72 [micro]g/m\3\ across 15 monitoring sites,
with all of the sites at or above the 0.2 [micro]g/m\3\ contribution
threshold and all but two of the sites above the 0.25 [micro]g/m\3\
contribution threshold. PM<INF>2.5</INF> responses in 2020 ranged from
0.12 to 0.42 [micro]g/m\3\, with nine sites above the 0.2 [micro]g/m\3\
contribution threshold and four sites
[[Page 45288]]
above the 0.25 [micro]g/m\3\ contribution threshold. Responses in 2024
ranged from 0.08 to 0.26 [micro]g/m\3\, with two sites above the 0.2
[micro]g/m\3\ contribution threshold and one site above the 0.25
[micro]g/m\3\ contribution threshold. For a modeled 70 percent ammonia
emissions reduction, the ambient PM<INF>2.5</INF> responses were above
both thresholds at all 15 sites for all three modeled years.
The State based its ammonia precursor determination on the
sensitivity analysis for the future years, using a 30 percent ammonia
emissions reduction. This was supported by its assessment of research
studies and the Plan's projected emissions reductions, and its
assessment of available emissions controls. As explained in the
PM<INF>2.5</INF> Precursor Guidance, precursor responses may be above
the recommended contribution threshold and yet not contribute
significantly to levels that exceed the standard in the area.\121\
Therefore, the State considered additional information to examine
whether the identified PM<INF>2.5</INF> responses constituted a
significant contribution to ambient PM<INF>2.5</INF> in the San Joaquin
Valley. The additional information included emissions trends, support
for the State's reliance on modeling results for a 30 percent ammonia
emissions reduction, as well as conclusions from research studies.
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\121\ PM<INF>2.5</INF> Precursor Guidance, p. 18.
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The State estimates that NO<INF>X</INF> emissions in the San
Joaquin Valley are projected to decrease by 53 percent from 2013 to
2024, while ammonia emissions are projected to remain relatively flat,
thereby increasing the relative abundance of ammonia.\122\ Based on the
Plan's emission reduction projections combined with the research study
conclusions, the State relies on the modeled responses for the 2024
future year, rather than the 2013 base year, stating that the future
year NO<INF>X</INF> emissions are more representative of San Joaquin
Valley emissions conditions.\123\ The State references the Draft
PM<INF>2.5</INF> Precursor Guidance, which notes that it may be
appropriate to model future conditions that are more representative of
current atmospheric conditions and those conditions expected closer to
the attainment date.\124\ The State concludes that this in fact applies
to the San Joaquin Valley.\125\
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\122\ March 2023 Ammonia Supplement, pp. 14-15.
\123\ Id. at 15 and 17.
\124\ Id. at 13 (referencing Draft PM<INF>2.5</INF> Precursor
Guidance, p. 33). See also PM<INF>2.5</INF> Precursor Guidance, p.
35.
\125\ Id. at 15.
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The State also describes previous research studies that support its
conclusion that ammonium nitrate PM<INF>2.5</INF> formation in the San
Joaquin Valley is NO<INF>X</INF>-limited rather than ammonia-
limited.\126\ For example, based on aircraft-borne measurements during
the 2013 DISCOVER-AQ campaign,\127\ the State concluded that ammonium
nitrate formation is NO<INF>X</INF>-limited based on the large amount
of ``excess ammonia,'' which is defined as the amount of measured
ammonia left over if all the nitrate and sulfate present were to
combine with available ammonia to form particulate.\128\ CARB's
December 2018 Staff Report describes these conclusions in more detail
and lists results from multiple other recent studies with similar
conclusions.\129\ The studies suggest a very low ambient sensitivity to
ammonia, based on measured excess ammonia relative to NO<INF>X</INF>,
the abundance of particulate nitrate relative to gaseous
NO<INF>X</INF>, and the large abundance of ammonia relative to nitric
acid. The studies all conclude that there is a large amount of ammonia
left over after reacting with NO<INF>X</INF>, so that ammonia emission
reductions would be expected mainly to reduce the amount of ammonia
excess, rather than to reduce the particulate amonium nitrate.
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\126\ 2018 PM<INF>2.5</INF> Plan, Appendix G, pp. 9-10; December
2018 Staff Report, Appendix C, pp. 12-15; and Attachment A to CARB's
May 9, 2019, submittal letter.
\127\ Deriving Information on Surface conditions from COlumn and
VERtically Resolved Observations Relevant to Air Quality,'' <a href="https://www.nasa.gov/mission_pages/discover-aq/index.html">https://www.nasa.gov/mission_pages/discover-aq/index.html</a>.
\128\ 2018 PM<INF>2.5</INF> Plan, Appendix G, Figure 2.
\129\ December 2018 Staff Report, Appendix C, p. 12; and
Attachment A to CARB's May 9, 2019 submittal letter. These studies
are also discussed in the EPA's February 2020 Precursor TSD.
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CARB also describes the results of two studies indicating that
ammonia concentrations may be underestimated in modeling of the
DISCOVER-AQ early 2013 study period, which would result in the response
to ammonia reductions being overpredicted.\130\ CARB conducted its own
analysis comparing 2017 satellite observations with CMAQ model
predictions and found that modeled ammonia concentrations were half of
the magnitude of the satellite observations at some locations and that
the modeled valley-wide average was approximately 25 percent less than
observed. Taken together, CARB concludes that these studies provide
evidence that PM<INF>2.5</INF> would respond only weakly to ammonia
emissions reductions.
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\130\ CARB's April 19, 2021 Precursor Clarification; CARB's
April 26, 2021 Precursor Clarification. The modeling used for the
attainment demonstration has enough excess ammonia to correctly
predict ammonium nitrate and ammonium sulfate PM<INF>2.5</INF>
concentrations, but likely less of an excess than indicated from
ambient measurements of ammonia itself.
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Finally, the State and District provided additional information,
both in the SJV PM<INF>2.5</INF> Plan and in the March 2023 Ammonia
Supplement, to support its conclusion that 30 percent is a reasonable
upper bound on the ammonia reductions that are practically available,
and as a basis for its reliance on the modeling results for a 30
percent ammonia emissions reduction. This information includes a review
of ammonia emission reductions achieved nationwide from 2011 to 2017 as
summarized in the EPA's PM<INF>2.5</INF> Precursor Guidance,\131\ an
evaluation of the main ammonia source categories in the San Joaquin
Valley,\132\ a summary of existing control measures in the San Joaquin
Valley that affect ammonia from these sources,\133\ a review of
existing control measures implemented by other air districts,\134\ and
an evaluation of additional mitigation options for ammonia sources in
the Valley.\135\ We briefly summarize the State's analyses and
conclusions for relying on a 30 percent upper bound in the following
paragraphs. For a more detailed summary of the State's ammonia control
measure analysis, please refer to the EPA's 1997 annual
PM<INF>2.5</INF> TSD.\136\
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\131\ March 2023 Ammonia Supplement, p. 11. See also
PM<INF>2.5</INF> Precursor Guidance, Section 4.1.1.
\132\ March 2023 Ammonia Supplement, pp. 20-25.
\133\ Id. at 25, and 2018 PM<INF>2.5</INF> Plan, Appendix C,
Section C-25.
\134\ March 2023 Ammonia Supplement, pp. 26-27, and 2018
PM<INF>2.5</INF> Plan, Appendix C, Section C-25.
\135\ March 2023 Ammonia Supplement, pp. 28-96.
\136\ EPA, Technical Support Document, ``San Joaquin Valley
PM<INF>2.5</INF> Plan Revision for the 1997 annual PM<INF>2.5</INF>
NAAQS,'' April 2023.
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First, CARB and the District reason that trends in ammonia
emissions provided in the PM<INF>2.5</INF> Precursor Guidance, which
show a national increase of 0.8 percent in ammonia emissions between
2011-2017, are indicative of a lack of controls on ammonia sources
nationwide.\137\ The March 2023 Ammonia Supplement includes a
comparison of the guidance trends in ammonia with trends in
NO<INF>X</INF> and SO<INF>2</INF> over the same period, which decreased
by 63.6 percent and 31.8 percent, respectively, which CARB and the
District attribute to control measures to reduce emissions of these
pollutants. The State acknowledges that new controls for ammonia are
being researched but states that the recent emissions trends suggest
that a 30 percent reduction in ammonia is a conservative upper bound on
what is achievable. To further support that statement, the District and
State
[[Page 45289]]
collaborated on an evaluation of potential control measures to reduce
ammonia emissions in the San Joaquin Valley for the March 2023 Ammonia
Supplement.
---------------------------------------------------------------------------
\137\ March 2023 Ammonia Supplement, p. 11.
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The first step in the control measure evaluation was to
characterize the key sources of ammonia in the Valley. The three main
sources of ammonia emissions identified in the Plan are: (1) confined
animal facilities (CAFs); (2) agricultural fertilizers; and (3)
composting operations, which together account for 94 percent of the
Valley's ammonia emissions.\138\ CAFs are subject to District Rule 4570
(``Confined Animal Facilities''), and composting operations are subject
to District Rule 4565 (``Biosolids, Animal Manure, and Poultry Litter
Operations'') and District Rule 4566 (``Organic Material Composting
Operations''). Although these District rules explicitly apply only to
VOC emissions from these sources, the State concludes that these rules
have also resulted in significant reductions in ammonia emissions.\139\
Appendix C of the 2018 PM<INF>2.5</INF> Plan cites a number of
scientific studies that address the correlation between VOC and ammonia
emissions from these emission sources.\140\ Given that CAFs and
agricultural fertilizers account for 92 percent of the ammonia
emissions inventory in the San Joaquin Valley,\141\ and that ammonia
emissions from composting operations account for only 2 percent of the
ammonia emissions inventory and have already been reduced through
District Rules 4565 and 4566, the ammonia control measure evaluation
focused primarily on potential controls for CAFs and agricultural
fertilizers.
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\138\ Id. at 20.
\139\ Id. at 26 and 96.
\140\ 2018 PM<INF>2.5</INF> Plan, Appendix C, Section C-25.
\141\ March 2023 Ammonia Supplement, Figure 4.
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For CAFs, the District provides an inventory of the types of
facilities operating in the Valley subject to Rule 4570 and the
corresponding ammonia emissions from each facility type.\142\ For dairy
cattle, which accounts for an estimated 67.2 percent of ammonia
emissions from CAFs, the District assessed how the different CAF
operations contribute to the overall ammonia inventory. For example,
the District estimates that 56.6 percent of dairy cattle ammonia
emissions are from housing dairy cattle in corrals/pens, 11.1 percent
of emissions are from lagoons and storage ponds, and 12.0 percent of
emissions occur during land application of liquid manure.\143\
---------------------------------------------------------------------------
\142\ Id. at Figure 5 and Table 7.
\143\ Id. at Figure 7.
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Next, the District discusses ammonia mitigation measures that are
already being implemented in the Valley. The District discusses in
detail in Appendix C of the 2018 PM<INF>2.5</INF> Plan how Rule 4570 is
structured (e.g., to address varying types of CAFs); the five main CAF
operations/emission sources: feeding, housing (including distinctions
for housing configurations), solid waste, liquid waste, and land
application of manure; the control menu requirements for each of those
five operations; and research papers that estimate ammonia emission
reductions from some of the measures.\144\ The District explains that
some of the measures in Rule 4570 are required to be implemented but
that the rule also requires additional measures to be selected from a
menu of options.\145\ The menu-based approach is intended to allow
facilities flexibility to select measures that are the most practical
and effective for their design and operation given the District's
findings of variability within the industry.\146\
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\144\ 2018 PM<INF>2.5</INF> Plan, Appendix C, pp. C-312 to C-
323.
\145\ Id. and March 2023 Ammonia Supplement, pp. 25-26.
\146\ Id.
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As a first step in assessing whether there are additional feasible
control measures for CAFs that are not yet being implemented in the
Valley, the District evaluated other district CAF rules with
requirements comparable to those in Rule 4570.\147\ The District
reviewed CAF rules implemented by the South Coast Air Quality
Management District (AQMD), Bay Area AQMD, Ventura County Air Pollution
Control District (APCD), Sacramento Metropolitan AQMD, Imperial County
APCD, and the State of Idaho.\148\ The District also points to
comparisons between Rule 4570 and two additional sets of requirements
imposed by Butte County APCD and Yakima Regional Clean Air Agency, as
conducted for the ``2016 Plan for the 2008 8-hour Ozone Standard.''
\149\ Based on comparisons between specific requirements, the State
concludes that Rule 4570 is more stringent than other district rules
and no additional requirements are currently being implemented in other
areas.\150\
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\147\ March 2023 Ammonia Supplement, pp. 26-27.
\148\ 2018 PM<INF>2.5</INF> Plan, Appendix C, Section C-25.
\149\ March 2023 Ammonia Supplement, p. 27.
\150\ Id.
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The second step in the control measure analysis was to review
scientific research studies on mitigating ammonia emissions from CAFs.
In Appendix A of the March 2023 Ammonia Supplement, the District
provides a list of research studies and potential ammonia control
measures it considered. For each of the 46 mitigation measures
identified in the literature, the State provides a narrative detailing
its evaluation of the feasibility of implementation of the measure in
the San Joaquin Valley.\151\ The State's analysis covers a broad range
of CAF activities, including animal feeding and housing, and the
storage, handling, and land application of manure. The analysis also
addresses a number of other mitigation options, such as pasture and
range land management, land use changes, and planting a tree shelter
belt near CAFs.\152\ Based on these evaluations, the State identified
three measures that could provide further reductions in ammonia
emissions in the San Joaquin Valley. These measures include 1) reducing
the crude protein content in feed for beef finishing cattle, 2)
incorporating solid manure into the soil within 24-hours, and 3) adding
acidifying amendments to poultry litter and manure.\153\ Based on
control efficiencies cited in the literature, the District estimates
that the total emissions reductions achievable from these measures is
6.6 tons per day (tpd), which is approximately two percent of the 2023
inventory. For those measures it found to be infeasible in the San
Joaquin Valley, the District includes a narrative explaining its
conclusion.
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\151\ Id. at 28-85.
\152\ Id. at 86-88.
\153\ Id. at 88-89.
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Regarding fertilizer application, the State provides an estimate of
111.2 tpd of ammonia emissions in 2023.\154\ In the 2018
PM<INF>2.5</INF> Plan, the District describes key research assessing
nitrogen in California, as well as regulations adopted by the
California Water Resources Control Board, including orders adopted by
the Central Valley Regional Water Quality Control Board (e.g., a
Nutrient Management Plan), the Irrigated Lands Regulatory Program
(e.g., a Nitrogen Management Plan), and other individual orders on
agricultural operations not subject to those programs.\155\ These
orders subject agricultural operators, including dairies, bovine
feedlots, poultry operations, and crop farmers to ``waste discharge
requirements that protect both surface water and groundwater.'' \156\
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\154\ Id. at 89.
\155\ 2018 PM<INF>2.5</INF> Plan, Appendix C, pp. C-339 to C-
343.
\156\ Id. at C-341.
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In the March 2023 Ammonia Supplement, the State supplemented its
prior analysis by explaining how various state agencies are engaged in
fertilizer use and application and discussing its efforts to identify
any
[[Page 45290]]
existing rules or regulations in the nation controlling ammonia
emissions from this source category.\157\ CARB states that it has not
identified any measures that are being implemented to reduce ammonia
and thus, again turns to scientific research studies on ammonia
mitigation measures to assess the potential emissions reductions that
could be achieved from fertilizer application. The measures identified
in the literature for reducing ammonia emissions from fertilizer
application include optimizing fertilizer use, adding a urease
inhibitor, mixing and injecting fertilizer into the soil quickly, and
applying fertilizer during optimal weather conditions. Based on its
review, the State finds that several of the strategies identified in
the literature are consistent with strategies recommended by the
California Department of Food and Agriculture Fertilizer Research and
Education Program as part of its Irrigation and Nitrogen Management
training program, which includes overviews of the ``4 R's'' of nitrogen
management: ``Right source'' of nitrogen at the ``right rate,'' ``right
time,'' and ``right place.'' \158\ However, the State concludes that
more research is needed to explore the feasibility and effectiveness of
requiring some of the identified strategies in California, due in part
to the warmer and dryer climate conditions in the San Joaquin Valley
compared to, for example, the European climate in which many of the
research studies were conducted, and due to the need to explore any
potential adverse consequences. Thus, the State concludes that
additional reductions in ammonia from fertilizer application are not
feasible at this time.\159\
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\157\ March 2023 Ammonia Supplement, pp. 89-92.
\158\ Id. at 92.
\159\ Id. at 96.
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For composting operations and other ammonia sources, the District
notes that it currently regulates ammonia emissions from composting
though Rules 4565 and 4566 and states that these rules have reduced
ammonia emissions by 44 percent. Given that composting amounts to only
two percent of the total ammonia emissions, the District did not
provide any further evaluation for this source category. For the
remaining ammonia sources in the Valley covered under ``other'' source
category, which amounts to 6 percent of the total inventory, the
District notes that ammonia emissions are primarily from mobile sources
and fuel combustion, which it asserts are also already controlled. The
District concludes that no additional reductions are available from
composting operations or other ammonia sources.\160\
---------------------------------------------------------------------------
\160\ Id.
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Taken together, the State estimates that ammonia emissions could be
reduced by 6.6 tpd in the San Joaquin Valley through three additional
mitigation measures for CAFs, which would amount to a total ammonia
reduction of 2 percent. Based on this analysis, the State concludes
that ammonia control measures achieving even the low end of the modeled
range (i.e., 30 percent) are not feasible for implementation in the San
Joaquin Valley, and that it is therefore reasonable to treat a 30
percent ammonia reduction as a conservative upper bound on the
reductions that are achievable, and to base the analysis in the
precursor demonstration on the model response to a 30 percent
reduction.
In summary, the State's sensitivity analysis presents a range of
PM<INF>2.5</INF> responses to ammonia emissions reductions in multiple
modeled years. The State describes in the Plan its bases for finding
that the 2024 future year sensitivity results better represent
conditions in the San Joaquin Valley than the 2013 base year, and for
finding a 30 percent ammonia reduction to be a reasonable upper bound
on the ammonia emissions reductions available for assessing the ammonia
contribution. Based on these analyses of the modeled response to
ammonia reductions below the threshold, additional ambient evidence,
and the amount of reductions available from controls, the State
concludes that ammonia does not contribute significantly to ambient
PM<INF>2.5</INF> levels above the 1997 annual PM<INF>2.5</INF> NAAQS in
the San Joaquin Valley.
b. SO<INF>X</INF>
For SO<INF>X</INF>, the State compares the annual precursor
contributions to the contribution threshold of 0.2 [micro]g/m\3\
recommended for the 2012 annual PM<INF>2.5</INF> NAAQS in the
PM<INF>2.5</INF> Precursor Guidance. For modeled SO<INF>X</INF>
emissions reductions of 30 percent and 70 percent, the ambient
PM<INF>2.5</INF> responses in 2013 ranged from -0.05 [micro]g/m\3\ to
0.15 [micro]g/m\3\ across 15 monitoring sites, which all fall below the
0.20 [micro]g/m\3\ contribution threshold.\161\ The response was below
zero in select cases, indicating an increase, rather than a decrease,
in ambient PM<INF>2.5</INF> in response to SO<INF>X</INF> emissions
reductions (i.e., a disbenefit). For 2020, the responses to 30 percent
and 70 percent emissions reductions ranged from -0.01 [micro]g/m\3\ to
0.16 [micro]g/m\3\ while for 2024, the responses ranged from 0.01
[micro]g/m\3\ to 0.08 [micro]g/m\3\; these are also all below the 0.2
[micro]g/m\3\ contribution threshold.\162\
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\161\ 2018 PM<INF>2.5</INF> Plan, Appendix G, tables 8 and 9.
\162\ CARB's September 2019 Precursor Clarification, 2020
analysis tables 7 and 8, and 2024 analysis tables 7 and 8.
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To explain the SO<INF>X</INF> emissions reduction disbenefit that
is observed in some cases, CARB refers to the non-linearity of
inorganic aerosol thermodynamics, as described in a study by West et
al.\163\ The paper discusses how, under certain conditions, reducing
SO<INF>X</INF> could free ammonia to combine with nitrate, increasing
overall PM<INF>2.5</INF> mass. To investigate this issue further, CARB
conducted simulations with the ISORROPIA inorganic aerosol
thermodynamic equilibrium model used within the CMAQ model and provided
clarifications to the EPA.\164\ In essence, CARB states that for some
conditions typical of San Joaquin Valley, ISORROPIA switches to a
different chemical regime in which the disbenefit occurs. CARB states
that it is not known how well this model behavior reflects the actual
atmosphere, but CARB accepts the results because it is a well-known and
widely used chemical model.
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\163\ 15 [micro]g/m\3\ SIP Revision, Appendix K, Section 5.7
(``PM<INF>2.5</INF> Precursor Sensitivity Analysis''); and West,
J.J., Ansari, A.S., Pandis, S.N., 1999, Marginal PM<INF>2.5</INF>:
Nonlinear aerosol mass response to sulfate reductions in the eastern
United States, Journal of the Air & Waste Management Association,
49, 1415-1424. <a href="https://doi.org/10.1080/10473289.1999.10463973">https://doi.org/10.1080/10473289.1999.10463973</a>.
\164\ CARB's June 2019 Precursor Clarification.
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The State also provides an emissions trend chart that shows that
SO<INF>X</INF> emissions are approximately constant at 8 tpd from 2013
through 2024. Given that the relative levels of estimated
SO<INF>X</INF> and ammonia emissions over the timeframe remain similar,
the State concludes that 2013 sensitivities are also representative of
future years.\165\
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\165\ 2018 PM<INF>2.5</INF> Plan, Appendix G, p. 15. The State
includes modeling of 30 percent and 70 percent reductions of
SO<INF>X</INF> for 2013 only, finding that the sensitivity of
ambient PM<INF>2.5</INF> to such changes were below the EPA's
recommended threshold, and that the 2020 and 2024 results would
differ little from 2013 due to the similarity of emissions
conditions over time. Appendix G, p. 17. CARB's September 2019
Precursor Clarification provides the 2020 and 2024 sensitivity
results, which are indeed very close to those for 2013.
---------------------------------------------------------------------------
Based on the small modeled response of ambient PM<INF>2.5</INF> to
SO<INF>X</INF> emissions reductions, the constant SO<INF>X</INF>
emissions over time, and its scientific understanding of sulfate
interactions with other molecules in the air, the State concludes that
SO<INF>X</INF> does not contribute significantly to ambient
PM<INF>2.5</INF> levels that exceed the 1997 annual
[[Page 45291]]
PM<INF>2.5</INF> NAAQS in the San Joaquin Valley.
c. VOC
For VOC, CARB compared the annual precursor contributions to the
EPA's recommended contribution threshold for the 2012 PM<INF>2.5</INF>
NAAQS of 0.2 [micro]g/m\3\. For a modeled 30 percent VOC emissions
reduction, the ambient PM<INF>2.5</INF> responses in 2013 ranged from
0.01 [micro]g/m\3\ to 0.16 [micro]g/m\3\ across 15 monitoring sites,
with all sites below the 0.2 [micro]g/m\3\ contribution threshold.\166\
The 2020 and 2024 responses ranged from -0.07 [micro]g/m\3\ to 0.06
[micro]g/m\3\, with all monitoring sites below the 0.2 [micro]g/m\3\
contribution threshold for both years. For a modeled 70 percent VOC
emissions reduction, the PM<INF>2.5</INF> responses in 2013 ranged from
0.05 [micro]g/m\3\ to 0.40 [micro]g/m\3\, including responses at or
above the 0.2 [micro]g/m\3\ contribution threshold at 8 of the 15
sites. However, for 2020 and 2024 all responses were below the 0.2
[micro]g/m\3\ contribution threshold; 2020 responses ranged from -0.10
[micro]g/m\3\ to 0.16 [micro]g/m\3\ and the 2024 responses ranged from
-0.18 [micro]g/m\3\ to 0.08 [micro]g/m\3\. The negative responses to
VOC reductions represent an increase in PM<INF>2.5</INF> levels, i.e.,
a disbenefit. The 2024 results show a disbenefit at 11 of the 15 sites
for both the 30 percent and the 70 percent VOC emissions reductions
scenarios.
---------------------------------------------------------------------------
\166\ 2018 PM<INF>2.5</INF> Plan, Appendix G, Table 10.
---------------------------------------------------------------------------
CARB then considered additional information to assess whether these
PM<INF>2.5</INF> responses constituted a significant contribution to
ambient PM<INF>2.5</INF> in the San Joaquin Valley, including emissions
trends and an assessment of the modeled disbenefit of VOC emissions
reductions. VOC emissions are projected to decrease approximately 30
tpd (or 9 percent) from 2013 to 2024, with approximately 28 out of the
30 tpd reduction taking place by 2020.\167\ The State concludes that
the formation of ambient PM<INF>2.5</INF> from VOC may therefore differ
in base and future years and that the sensitivity analysis for 2013,
which showed some contributions above 0.2 [micro]g/m\3\, is not
representative of current or future conditions.
---------------------------------------------------------------------------
\167\ Id. at p. 19 and Figure 5.
---------------------------------------------------------------------------
CARB explained the modeled disbenefit of VOC reductions as follows:
emissions of VOC and NO<INF>X</INF> react in the atmosphere to form
organic nitrate species, such as peroxyacetyl nitrate, meaning that
some portion of the NO<INF>X</INF> emissions is not available to react
with ammonia to form ammonium nitrate particulate matter. In other
words, VOC emissions can be a ``sink'' for NO<INF>X</INF> emissions.
Reducing VOC emissions therefore reduces the formation of organic
nitrates, so the sink is smaller and nitrate molecules are freed to
react with ammonia to form particulate ammonium nitrate.\168\ The State
further explored the VOC disbenefit based on a 2016 CARB modeling
assessment provided in Appendix A (``Air Quality Modeling'') of the
``2016 Moderate Area Plan for the 2012 PM<INF>2.5</INF> Standard'' for
the San Joaquin Valley (``2016 PM<INF>2.5</INF> Plan''), which CARB
submitted to the EPA as a SIP revision on May 10, 2019.\169\
---------------------------------------------------------------------------
\168\ 15 [micro]g/m\3\ SIP Revision, Appendix K, pp. 81-82
(citing Meng, Z., D. Dabdub, D., Seinfeld, J.H., Chemical Coupling
Between Atmospheric Ozone and Particulate Matter, Science 277, 116
(1997). DOI: 10.1126/science.277.5322.116).
\169\ 2016 PM<INF>2.5</INF> Plan, Appendix A, p. A-57. See also
15 [micro]g/m\3\ SIP Revision, Appendix K, Section 5.7
(``PM<INF>2.5</INF> Precursor Sensitivity Analysis'').
---------------------------------------------------------------------------
Based on its sensitivity-based analysis of VOC emissions
reductions, VOC emissions trends, and the scientific understanding of
VOC chemistry in the San Joaquin Valley, CARB concludes that VOC
emissions do not contribute significantly to PM<INF>2.5</INF> levels
that exceed the 1997 annual PM<INF>2.5</INF> NAAQS in the San Joaquin
Valley.
3. The EPA's Review of the State's Submission
The EPA has evaluated the State's precursor demonstration in the
SJV PM<INF>2.5</INF> Plan, consistent with the PM<INF>2.5</INF> SIP
Requirements Rule and the recommendations in the PM<INF>2.5</INF>
Precursor Guidance. The State did not present a precursor demonstration
for NO<INF>X</INF>, and indeed stated that controlling it is essential
for the attainment strategy; \170\ NO<INF>X</INF> emission sources,
therefore, remain subject to control requirements under subparts 1 and
4 of part D, title I of the Act. For the reasons provided in the
following paragraphs, the EPA proposes to approve the State's
comprehensive demonstrations for ammonia, SO<INF>X</INF>, and VOC based
on a conclusion that emissions of these precursor pollutants do not
contribute significantly to ambient PM<INF>2.5</INF> levels that exceed
the 1997 annual PM<INF>2.5</INF> NAAQS in the San Joaquin Valley. For
further discussion of the EPA's evaluation of the precursor
demonstration, please see the EPA's February 2020 Precursor TSD, which
provides the EPA's summary of the State's precursor analyses for all
four PM<INF>2.5</INF> precursors.\171\
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\170\ 2018 Plan Appendix G, p. 2.
\171\ Much of the analysis in the EPA's February 2020 Precursor
TSD is applicable to SJV PM<INF>2.5</INF> Plan for the 1997 annual
PM<INF>2.5</INF> NAAQS. For example, the State's precursor
demonstration used 2015 annual average concentration data for its
concentration-based analysis, examined annual average sensitivities
of ambient PM<INF>2.5</INF> concentrations to reductions in each
precursor in 2013, 2020, and 2024, and presented information on
research studies and emission trends that are relevant for assessing
the sensitivity of annual average ambient PM<INF>2.5</INF>
concentrations to emission reductions of each PM<INF>2.5</INF>
precursor. Our evaluation of such factors is similarly applicable
for the 1997 annual PM<INF>2.5</INF> NAAQS and we expand on such
evaluation for purposes of those NAAQS specifically herein.
---------------------------------------------------------------------------
The State based its analyses on the latest available data and
studies concerning ambient PM<INF>2.5</INF> formation in the San
Joaquin Valley from precursor emissions. For the required
concentration-based analysis, the State assessed the absolute annual
average contribution of each precursor to ambient PM<INF>2.5</INF> in
2015. Given that the absolute concentrations in 2015 were above the
EPA's recommended contribution thresholds for both the 2006 24-hour and
2012 annual average NAAQS, the State proceeded with a sensitivity-based
analysis, consistent with the recommendations in the PM<INF>2.5</INF>
SIP Requirements Rule.
For the sensitivity-based analysis, the State performed its
analyses based on the EPA's recommended approach--i.e., for each
modeled year and level of precursor emissions reduction (in
percentages), the State estimated the ambient PM<INF>2.5</INF> response
using the procedure recommended in the PM<INF>2.5</INF> Precursor
Guidance. In particular, the State considered the EPA's recommended
range of emissions reductions (30 percent to 70 percent) for the 2013
base year, 2020 interim year, and 2024 future year, and quantified the
estimated response of ambient PM<INF>2.5</INF> concentrations to
precursor emission changes in the San Joaquin Valley.
The State's emissions projections in the 2018 PM<INF>2.5</INF> Plan
show that baseline emissions of each of these precursors will decrease
from the 2013 base year to the 2023 attainment year. These decreases
are included in the State's modeled projections of ambient
PM<INF>2.5</INF> levels in the San Joaquin Valley for purposes of
demonstrating attainment and RFP. The State's sensitivity analyses are
consistent with these projections, in accordance with the EPA's
recommendations in the PM<INF>2.5</INF> Precursor Guidance.\172\
---------------------------------------------------------------------------
\172\ PM<INF>2.5</INF> Precursor Guidance, p. 35.
---------------------------------------------------------------------------
The EPA is proposing to find that such quantification and CARB's
consideration of additional information provide an informed basis on
which to make a determination as to whether ammonia, SO<INF>X</INF>,
and VOC contribute significantly to ambient PM<INF>2.5</INF> levels
that exceed the 1997 annual PM<INF>2.5</INF> NAAQS in the San Joaquin
Valley.\173\ If we
[[Page 45292]]
finalize this proposal to approve the State's precursor demonstrations,
the State will not be required to implement BACM/BACT level controls
for sources of ammonia, SO<INF>X</INF>, and VOC for purposes of the SJV
PM<INF>2.5</INF> Plan for 1997 annual PM<INF>2.5</INF> NAAQS that is
the subject of this proposed action. Under 40 CFR 51.1006(b), such
precursor demonstration approval would apply only to this attainment
plan. For any new PM<INF>2.5</INF> attainment plan that the State is
required to submit in accordance with 40 CFR 51.1003 for purposes of
any PM<INF>2.5</INF> NAAQS, the State will be required to submit an
updated precursor demonstration if it seeks to exempt sources of a
particular precursor from control requirements in that attainment plan.
In the subsections that follow, we summarize our evaluation of the
State's precursor demonstrations for each of these three precursor
pollutants.
---------------------------------------------------------------------------
\173\ The State did not evaluate the 2015 Serious area
attainment year. Because the year has passed and the area failed to
attain by the Serious area attainment date, we will evaluate the
precursor analysis for the Serious area plan based on the current
section 189(d) projected attainment date of December 31, 2023.
---------------------------------------------------------------------------
a. Ammonia
We have evaluated CARB's sensitivity-based contribution analyses
for 2013, 2020, and 2024 in the 2018 PM<INF>2.5</INF> Plan and
supplemental materials provided by the State, as well as CARB's
determination that the 2024 results are representative of conditions in
the San Joaquin Valley for purposes of a sensitivity-based analysis for
the 1997 annual PM<INF>2.5</INF> NAAQS. The EPA's PM<INF>2.5</INF>
Precursor Guidance explicitly provides for consideration of a future
year, and we are proposing to find that the State provided sufficient
justification for relying on modeling results for 2024.\174\
---------------------------------------------------------------------------
\174\ PM<INF>2.5</INF> Precursor Guidance, p. 35.
---------------------------------------------------------------------------
We also consider it appropriate for the State to take into account
additional information as part of its evaluation of whether the ammonia
contribution is significant and to rely on the responses to the 30
percent modeled ammonia emissions reduction in its precursor
demonstration for ammonia. The modeled PM<INF>2.5</INF> response to the
30 percent reduction is only marginally above the contribution
threshold at a single monitoring site in 2024, and the EPA has evidence
from the State and elsewhere that the response was overestimated, as
discussed below. Together these suggest that ammonia does not
contribute significantly to ambient PM<INF>2.5</INF> levels. However,
because the response is so close to the threshold at a 30 percent
reduction, such a conclusion strongly depends on the emission reduction
benefit of potential controls being 30 percent or less; larger
reductions could give responses above the threshold. Therefore, per 40
CFR 51.1010(a)(2)(ii), the EPA required an analysis of potential
controls to aid the EPA in its evaluation of the precursor
demonstration, which the State provided in the March 2023 Ammonia
Supplement. The response of ambient PM<INF>2.5</INF> to an actual
assessment of the benefit from potential controls could then be used by
the State to determine whether controlling ammonia would significantly
affect PM<INF>2.5</INF> levels.
The State relied on the 2024 modeled ambient PM<INF>2.5</INF>
responses to a 30 percent reduction in ammonia after concluding that 30
percent was a reasonable upper bound on potential ammonia reductions,
based on past research on ammonia emissions and its evaluation of
potential control options. Based on the EPA's review of the State's
rationale, including its ammonia control measure analysis, the EPA
agrees that the reductions that the State could achieve through
additional available BACM/BACT level controls on ammonia sources would
be below 30 percent, and thus that the PM<INF>2.5</INF> response to the
ammonia emission reductions available would be below the contribution
threshold at all sites for purposes of this plan, as discussed in the
following paragraphs.\175\
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\175\ Note that the task for the State is not to show whether
controls could reduce ammonia by 30 percent, though that is the
focus of the State's March 2023 Ammonia Supplement. The SIP
requirements rule and the PM<INF>2.5</INF> Precursor Guidance do not
establish potential reductions of 30 percent as a ``bright line''
test for determining precursor significance. Rather, information
from the control evaluation is to be used in conjunction with other
information to determine whether ammonia reductions are effective in
reducing PM<INF>2.5</INF> levels, and so whether ammonia contributes
significantly to PM<INF>2.5</INF>.
---------------------------------------------------------------------------
The State compared the ammonia modeled sensitivity results in
Appendix G of the 2018 PM<INF>2.5</INF> Plan to the 0.2 [micro]g/m\3\
contribution threshold recommended by the EPA for the 2012 annual
PM<INF>2.5</INF> NAAQS in the PM<INF>2.5</INF> Precursor Guidance.
However, in the March 2023 Ammonia Supplement, the State also compared
the model results against the 0.25 [micro]g/m\3\ contribution threshold
it calculated based on the level of the 1997 annual PM<INF>2.5</INF>
NAAQS. We find that the State's use of a 0.25 [micro]g/m\3\ threshold
is consistent with the recommendations in the PM<INF>2.5</INF>
Precursor Guidance,\176\ and is appropriate for purposes of evaluating
the modeling results for the 1997 annual PM<INF>2.5</INF> NAAQS, given
the EPA's method of calculating the threshold and the level of the 1997
annual PM<INF>2.5</INF> NAAQS (15.0 [micro]g/m\3\).
---------------------------------------------------------------------------
\176\ PM<INF>2.5</INF> Precursor Guidance, fn. 20.
---------------------------------------------------------------------------
The precursor demonstration in the SJV PM<INF>2.5</INF> Plan
indicates that the ambient response to a 30 percent ammonia emission
reduction would exceed the 0.25 [micro]g/m\3\ contribution threshold
for 13 out of 15 monitoring sites in the 2013 analysis year, and at 4
out of 15 for the 2020 analysis year. For the 2024 analysis year, 1 of
the 15 sites (Hanford) would exceed the contribution threshold. In
absolute terms, the ambient PM<INF>2.5</INF> response declines from
0.24 [micro]g/m\3\ in 2020 to 0.12 [micro]g/m\3\ in 2024 at
Bakersfield-Planz, the highest concentration site. The Hanford
responses decline from 0.42 [micro]g/m\3\ in 2020 to 0.26 [micro]g/m\3\
in 2024. The average response over all monitoring sites declines from
0.23 [micro]g/m\3\ to 0.14 [micro]g/m\3\, with the decline being
generally larger for the sites with the highest projected
PM<INF>2.5</INF> levels.
While the 2024 Hanford modeled response to a 30 percent ammonia
reduction is above the contribution threshold, additional information
about this location leads the EPA to give the response lower weight in
the overall assessment of whether ammonia contributes significantly to
PM<INF>2.5</INF> levels. An independent study using aircraft and
surface data from the winter 2013 DISCOVER-AQ \177\ campaign, a key
period in the SJV PM<INF>2.5</INF> Plan's 2013 model base case, found
that the CMAQ model underestimated ammonia at Hanford by roughly a
factor of five; Hanford is just outside a region with high ammonia
emissions in the model (western Tulare County).\178\ If the modeled
ammonia concentrations were higher to better match observations, there
would be relatively more ammonia per NO<INF>X</INF> and the model
response to ammonia reductions would be lower. This is consistent with
CARB's conclusions regarding ammonia as described earlier.
---------------------------------------------------------------------------
\177\ NASA, ``Deriving Information on Surface conditions from
Column and VERtically Resolved Observations Relevant to Air
Quality,'' described at <a href="https://www.nasa.gov/mission_pages/discover-aq/index.html">https://www.nasa.gov/mission_pages/discover-aq/index.html</a>.
\178\ Kelly, J.T. et al. 2018, ``Modeling
NH<INF>4</INF>NO<INF>3</INF> over the San Joaquin Valley during the
2013 DISCOVER-AQ campaign,'' Journal of Geophysical Research:
Atmospheres, 123, pp. 4727-4745, <a href="https://doi.org/10.1029/2018JD028290">https://doi.org/10.1029/2018JD028290</a> at 4733. The paper notes that, despite the ammonia
underestimation, model performance was good for particulate ammonium
nitrate and the ammonium nitrate was not sensitive to the ammonia
underestimate since its formation was NO<INF>X</INF>-limited.
---------------------------------------------------------------------------
In choosing which year's modeled response to ammonia to rely on,
the EPA considered the State's point that the PM<INF>2.5</INF> benefit
of ammonia emission reductions is projected to decline steeply over
time. We believe it is appropriate to consider changes in
[[Page 45293]]
atmospheric chemistry that may occur between the base or current year
and the attainment year because the changes may ultimately affect the
nonattainment area's progress toward expeditious attainment. The
PM<INF>2.5</INF> Precursor Guidance explicitly states that a future
year may be used, and that there are a multitude of considerations in
choosing the analysis year.\179\ The ``anticipated growth or loss of
sources . . . or trends in ambient speciation data and precursor
emissions'' \180\ are among the ``facts and circumstances of the area''
\181\ to consider in determining the significance of a precursor. The
Guidance states that a future year could be more appropriate if it
better represents the period that sources will operate in. As discussed
in more detail below, the 2024 model results better represent the
period that ammonia sources will operate in than 2013 and 2020 because
of the steep decline in NO<INF>X</INF> emissions projected to occur by
2023 and 2024. We consider it reasonable for the State to focus on the
ambient PM<INF>2.5</INF> response to ammonia emission reductions in
2024, rather than 2013 or 2020, as the modeled response in 2024 in the
San Joaquin Valley better reflects the potential benefit of ammonia
control measures for purposes of expeditious attainment of the 1997
annual PM<INF>2.5</INF> NAAQS.
---------------------------------------------------------------------------
\179\ PM<INF>2.5</INF> Precursor Guidance, p. 35.
\180\ Id. at 18.
\181\ PM<INF>2.5</INF> SIP Requirements Rule, 40 CFR
51.1006(a)(1)(ii).
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The State's precursor demonstration in the SJV PM<INF>2.5</INF>
Plan shows that ambient sensitivity to ammonia emissions reductions in
the San Joaquin Valley declines steeply over time. Between 2020 and
2024, the modeled response to a 30 percent ammonia emissions reduction
declines by 50 percent at the Bakersfield-Planz monitoring site, which
has the highest projected PM<INF>2.5</INF> level, and by 37 percent
averaged over all monitoring sites. As noted above, in absolute terms,
the ambient PM<INF>2.5</INF> response declines from 0.24 [micro]g/m\3\
in 2020 to 0.12 [micro]g/m\3\ in 2024 at Bakersfield-Planz, and from
0.23 [micro]g/m\3\ to 0.14 [micro]g/m\3\ as averaged over all
monitoring sites, with the decline being generally larger for the sites
with the highest projected PM<INF>2.5</INF> levels. Thus, between 2020
and 2024, the number of sites at which modeled sensitivity exceeds the
0.25 [micro]g/m\3\ threshold for the 1997 annual PM<INF>2.5</INF> NAAQS
declines from 4 out of 15 down to 1 out of 15.\182\ As discussed
earlier, ammonia sensitivity declines because of the shifting
atmospheric chemistry caused by NO<INF>X</INF> emissions decreases.
NO<INF>X</INF> emissions are projected to decrease by 27 percent
between 2020 and 2024 due to baseline measures (e.g., existing motor
vehicle controls), with 91 percent of those emissions reductions
occurring between 2020 and 2023.\183\ That is, NO<INF>X</INF> emissions
in 2023 are 24 percent lower than NO<INF>X</INF> emissions in 2020 and
3 percent higher than NO<INF>X</INF> emissions in 2024. Thus,
conditions in 2024 are anticipated to be much more similar to those in
2023 compared to 2020. The decreased NO<INF>X</INF> emissions will make
ammonia more abundant relative to NO<INF>X</INF>, and even less of a
limiting factor on PM<INF>2.5</INF> formation. In other words, the
model response in the future year 2024 gives a more realistic
assessment of the potential effect of ammonia controls than past
conditions.\184\
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\182\ 2018 PM<INF>2.5</INF> Plan, Appendix G, tables 4 and 5.
\183\ NO<INF>X</INF> emissions in 2020, 2023, and 2024 are 203.3
tpd, 153.6 tpd, and 148.9 tpd, respectively.
\184\ Since precursor sensitivity modeling results were not
available for the specific year of 2023, the EPA estimated the 2023
PM<INF>2.5</INF> response to a 30 percent ammonia reduction using
the modeling results for 2020 and 2024. As for the 2024 modeled
sensitivities, we found that Hanford was the only site that would be
above the 0.25 [micro]g/m\3\ contribution threshold for 2023, with a
response of 0.27 [micro]g/m\3\. Thus, the results of this exercise
do not change our conclusions. Spreadsheet ``Estimated 2023 annual
PM<INF>2.5</INF> sensitivity to ammonia reductions.xlsx,'' EPA
Region IX, June 26, 2023.
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Additionally, the ambient studies described by the State and in
independent research studies provide strong evidence that
PM<INF>2.5</INF> would respond only weakly to ammonia emissions
reductions. As described above, those include a large measured excess
of ammonia relative to the amount of nitrate available to interact with
it to form PM<INF>2.5</INF>, and satellite and aircraft measurements
indicating a larger amount of ammonia than is derived in model
predictions. This evidence reflects actual measurements of the
atmosphere, independent of uncertainties in the modeling and
independent of estimates of ammonia and other emissions that are input
to the model.
Finally, the EPA has reviewed the additional information provided
by the State to support its assertion that 30 percent is a reasonable
upper bound on the ammonia reductions that could be achieved in the San
Joaquin Valley and the State's reliance on the 30 percent sensitivity
modeling results for the precursor demonstration for the 1997 annual
PM<INF>2.5</INF> NAAQS. The EPA proposes to find that the additional
information adequately supports the conclusion that potential ammonia
controls would yield less than a 30 percent reduction, such that the
resulting decrease in ambient PM<INF>2.5</INF> concentration would be
below the contribution threshold. As discussed in Section IV.B.1 of
this document, the PM<INF>2.5</INF> Precursor Guidance indicates that
the EPA may require air agencies to identify and evaluate potential
emissions controls in support of a precursor demonstration that relies
on a sensitivity analysis, particularly for an area in which the
PM<INF>2.5</INF> response to a 30 percent reduction in precursor
emissions is close to the contribution threshold. For the San Joaquin
Valley, the modeled response to a single site, Hanford, is just above
the 0.25 [micro]g/m\3\ threshold for the 1997 annual PM<INF>2.5</INF>
NAAQS at 0.26 [micro]g/m\3\. Furthermore, several analyses show ambient
ammonia concentrations are underestimated at Hanford and so we believe
that the 2024 modeled response of 0.26 [micro]g/m\3\ is likely
overestimated. Supporting that conclusion is the evidence of the large
ambient excess of ammonia relative to nitrate, which suggests that the
actual PM<INF>2.5</INF> response to reductions in ammonia emissions
would be very small, and less than the response seen in the modeling.
Thus, we conclude that in the San Joaquin Valley, the PM<INF>2.5</INF>
response to a 30 percent reduction in ammonia emissions is close to the
contribution threshold and that the State's approach to evaluate
additional information in support of the precursor demonstration
sensitivity analysis, including additional potential ammonia control
measures, is consistent with the EPA's recommendations in the
PM<INF>2.5</INF> Precursor Guidance and responsive to the EPA's request
for such additional information and analysis.
As discussed in Section IV.B.2.a of this document, the State began
its analysis to identify and evaluate potential emissions controls for
ammonia by characterizing key ammonia source categories in the Valley
(i.e., CAFs, agricultural fertilizers, and composting operations), and
identifying existing rules that have resulted in ammonia emission
reductions from these sources. Specifically, the State discusses the
ammonia control effectiveness of a number of existing rules designed to
reduce VOC emissions from these sources.\185\ While there are no
ammonia-specific controls in place for these source categories, the EPA
agrees with the District's information indicating that some of the
management practices in the District's rules to reduce VOC emissions
also reduce ammonia
[[Page 45294]]
emissions by limiting ammonia formation and volatilization.\186\
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\185\ 2018 PM<INF>2.5</INF> Plan, Appendix C, pp. C-311 to C-
358.
\186\ For example, see 2018 PM<INF>2.5</INF> Plan, Appendix C,
p. C-313 (for CAFs).
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Regarding the analysis for CAFs, we find that the District provided
a thorough evaluation of potential ammonia mitigation measures by CAF
type and activity through its comparison of the applicability and
requirements of Rule 4570 with comparable rules that are being
implemented in other air districts and its review of scientific
research studies. In considering the technical feasibility of each
identified measure, the District assessed factors such as how the
measure compares with requirements already being implemented under
District Rule 4570, the compatibility of the measure with the types of
CAFs operating in the Valley (considering, for example, CAF size and
common practices employed), compatibility of the measure with the
climate conditions in the Valley, and any cobenefits and/or undesirable
consequences of implementing the measure.
Based on its evaluation, the District determined that several
measures identified in the literature are already required in the San
Joaquin Valley by Rule 4570 (e.g., washing floors and other soiled
areas in livestock facilities), or by other State regulations (e.g.,
requirements to carefully time manure application as required by the
California Regional Water Quality Control Board).<SUP>187 188</SUP> For
measures that the District identified as feasible for implementation in
the San Joaquin Valley, the District provided information detailing how
it estimated the potential ammonia emission reductions that could be
achieved based on control efficiencies cited in the literature. For
measures that the State determined to be infeasible in the San Joaquin
Valley, the District provided a narrative justification for its
conclusion.
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\187\ March 2023 Ammonia Supplement, pp. 47-49.
\188\ Id. at 77.
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Reasons for concluding that a particular measure is infeasible
included that the measure is not conducive to the type, size, or
standard practices of CAFs operating in the Valley; the measure is not
compatible with the hot, dry, drought climate conditions in the Valley;
the measure is not economically feasible; or that the measure would
have undesirable consequences (e.g., adverse effects on water quality,
reduced dairy cattle milk production). The District also concluded that
more research is needed to examine the technical and/or economic
feasibility of implementing some of the measures in the Valley
specifically. For those measures that the District found to be
economically infeasible (e.g., biofilters and wet scrubbers,
oxygenation of liquid manure lagoons), it provided detailed cost
analyses to support its assertion.\189\ Based on our review of the
District's controls analysis for CAFs, we find that the District
provided a robust analysis of its Rule 4570 and a thorough review of 46
possible mitigation measures for reducing ammonia emissions from CAFs
in the San Joaquin Valley.
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\189\ Id. at 59-60 and Appendix B.
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For fertilizer application, the State emphasizes that it has not
identified any SIP-approved requirements that are being implemented in
other areas. Thus, it describes regulations adopted by other California
State agencies to control fertilizer application, such as regulations
adopted by the California Water Resources Board, and otherwise focuses
its review on several research studies on reducing ammonia emissions
from synthetic fertilizer application. Based on its review of
mitigation options in the literature, the State concludes that some of
the mitigation strategies are already required by current State
regulations, and that further research is needed to explore the
feasibility and effectiveness of those measures that are not currently
in practice.
Regarding State regulations that are currently in place to control
fertilizer application, we generally agree with the State that those
regulations are likely to enhance the retention of nitrogen from manure
and nitrogen-based chemical fertilizers in the San Joaquin Valley and
to limit the loss of nitrogen as pollution to water and air, thereby
potentially reducing ammonia emissions. Additionally, as discussed
earlier, District Rules 4570 and 4565 have provisions that reduce
ammonia emissions by addressing the land application of manure from
CAFs and of biosolids, animal manure, and poultry litter from
composting operations. The EPA believes that the State's review of both
existing ammonia mitigation measures and the research literature is an
appropriate and thorough method for identifying potential measures. We
also believe it reasonable that the State concludes that several of the
specific mitigation strategies identified in the literature, such as
optimizing fertilizer use, are already being implemented in the San
Joaquin Valley due to these current State regulations and co-benefits
such as reduced cost to farmers, and that more research is needed to
assess the feasibility of other additional measures identified. Based
on our review, and the fact that the State did not identify any ammonia
mitigation measures for fertilizer application being implemented in
other areas, we conclude that the State's overall conclusions are
reasonable.
For composting and other sources, the District notes that
significant ammonia reductions are already being achieved by existing
rules, including a 44 percent reduction from composting operations from
Rules 4565 and 4566, and reductions from mobile source and fuel
combustion measures. As discussed earlier, the EPA agrees that Rules
4565 and 4566 have reduced ammonia emissions in the Valley. We also
agree that the State's stringent controls for on-road mobile sources
have resulted in ammonia reductions from those sources. While the State
continues to work to reduce emissions from mobile sources to reduce
NO<INF>X</INF> and other pollutants in the Valley, since on-road mobile
sources account for approximately one percent of the ammonia emissions
inventory,\190\ any ammonia reductions achievable through additional
on-road mobile source controls would be small. The District states that
it did not identify any additional potential mitigation measures for
these source categories.
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\190\ 2018 PM<INF>2.5</INF> Plan, Appendix B, Table B-5.
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While we generally find that the State provided a robust review of
existing regulations and potential additional mitigation measures in
the research literature, we note that a limitation of the District's
analysis is that there remains some uncertainty as to how much
reduction is currently being achieved by State and District rules and
thus if some incremental additional reduction may be available. For
fertilizer application specifically, the District does not attempt to
quantify or otherwise substantiate the scale of ammonia emission
reductions from existing regulations, nor their enforceability, which
confounds the prospects for quantifying how much additional reductions
may be available. Furthermore, while the District provides a detailed
controls analysis for CAFs, with regard to Rule 4570, as the EPA has
previously noted,\191\ the State has not sufficiently substantiated its
calculation of the 100 tpd of ammonia emission reductions attributed to
Rule 4570. In the 2018 PM<INF>2.5</INF> Plan, the State references an
analysis from 2006 that relied on a different baseline emissions
inventory, but has not supplemented this analysis, or reconciled it
with more recent
[[Page 45295]]
emissions inventory data.\192\ While the EPA agrees that meaningful
ammonia reductions have been achieved from Rule 4570, there remains
some uncertainty as to the precise magnitude of those reductions.
Notwithstanding this uncertainty, as discussed in more detail below,
given the scarcity of additional feasible measures identified by the
State, and the scale of potential additional emissions reductions
available in the context of the sensitivity of PM<INF>2.5</INF> to
ammonia reductions in the nonattainment area for the 1997 annual
PM<INF>2.5</INF> NAAQS, we find that the controls analysis provided by
the State is sufficient to support its conclusion that that ammonia
emissions do not contribute significantly to ambient PM<INF>2.5</INF>
levels that exceed the 1997 annual PM<INF>2.5</INF> NAAQS in the San
Joaquin Valley.
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\191\ 81 FR 69396, 69397-69398 (October 6, 2016) and 87 FR
60494, 60503-60504 (October 5, 2022).
\192\ 2018 PM<INF>2.5</INF> Plan, Appendix C, pp. C-311 to C-339
and SJVUAPCD, ``Final Draft Staff Report, Proposed Re-Adoption of
Rule 4570 (Confined Animal Facilities),'' June 18, 2009, at Appendix
F, ``Ammonia Reductions Analysis for Proposed Rule 4570 (Confined
Animal Facilities),'' June 15, 2006 (discussing various assumptions
underlying the District's calculation of ammonia emission factors
without identifying relevant emissions inventories).
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Based on its analysis, the State concludes that significant ammonia
reductions have already been achieved in the San Joaquin Valley through
existing State regulations and standard practices, and that the
potential additional ammonia emissions reductions achievable through
the implementation of additional best available controls is two percent
of the total ammonia emissions in the San Joaquin Valley. This value is
well below the lower end (i.e., 30 percent) of the ammonia reductions
that the State modeled for analytical purposes for its sensitivity-
based analysis. While there remains some uncertainty as to the ammonia
reductions that are currently being achieved by existing rules and
standard practices, and thus the additional reductions that could be
achieved by those rules and practices, we believe the State has
provided sufficient evidence to support its assertion that the
additional available reductions are less than 30 percent.
Specifically, the District has made a convincing case that
significant ammonia reductions have already been achieved through
District Rule 4570 and that few additional mitigation measures could
provide only modest further reductions from CAFs, which account for 58
percent of the total ammonia inventory. Similarly, the State has
provided support for its assertion that additional reductions are not
feasible from the fertilizer, composting, and other smaller source
categories through its analysis of potential fertilizer controls, in
particular, in addition to information regarding controls that are
already in place for these source categories.\193\ Based on our review
of the analysis, we conclude that the potential reduction from
available controls would be well below 30 percent. Given that the
State's modeled sensitivities of PM<INF>2.5</INF> concentrations to a
30 percent ammonia reduction are approximately at or below the
threshold used for identifying an impact that is significant for the
1997 annual PM<INF>2.5</INF> NAAQS, and that potential reductions would
be below 30 percent, the EPA agrees that the response of
PM<INF>2.5</INF> to an ammonia reduction of a percentage smaller than
30 percent would be below the contribution threshold, indicating that
ammonia does not contribute significantly to ambient PM<INF>2.5</INF>
concentrations for purposes of the SJV PM<INF>2.5</INF> Plan for the
1997 annual PM<INF>2.5</INF> NAAQS.
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\193\ The State has not provided an estimate of the reductions
that are currently being achieved for the fertilizer category, which
accounts for 34 percent of the total ammonia emissions inventory.
Nevertheless, even if ammonia emissions from fertilizers could be
reduced by a very high percentage (e.g., 70 percent), that would
correspond to a smaller percentage reduction of the total ammonia
emissions. Such conservatively high reductions from fertilizers
added to the potential ammonia reductions from CAFs identified by
the State would still amount to less than a 30 percent reduction of
the total ammonia emissions.
---------------------------------------------------------------------------
In summary, we conclude that the State quantified the sensitivity
of ambient PM<INF>2.5</INF> levels to reductions in ammonia emissions
using appropriate modeling techniques, the modeled response to ammonia
reductions is likely lower than reported, and the State's choice of
2024 as the reference point for purposes of evaluating the sensitivity
of ambient PM<INF>2.5</INF> levels to ammonia emissions reductions is
well-supported. The State also provided strong evidence to support its
conclusion that additional controls on ammonia sources would achieve
ammonia emissions reductions well below 30 percent, including its
estimate, following review of the measures the State and District
consider feasible, that the reductions available are approximately 2
percent. Since the modeled ambient PM<INF>2.5</INF> response to a 30
percent ammonia reduction is only marginally above the contribution
threshold at a single monitoring site, that response may be
overestimated, and potential reductions are below 30 percent, the
PM<INF>2.5</INF> response to additional ammonia controls would be below
the contribution threshold. Based on these considerations, the EPA
proposes to approve the State's demonstration that ammonia emissions do
not contribute significantly to ambient PM<INF>2.5</INF> levels that
exceed the 1997 annual PM<INF>2.5</INF> NAAQS in the San Joaquin
Valley.
We note that this proposed determination is specific to the facts
and circumstances of this particular plan--including but not limited to
the specific level of the 1997 annual PM<INF>2.5</INF> NAAQS and the
proportional modeling response needed to be considered significant, the
State's modeling indicating that ammonia levels the San Joaquin Valley
are at or below the contribution threshold for the 1997 annual
PM<INF>2.5</INF> NAAQS, the unique atmospheric conditions in the Valley
in which the PM<INF>2.5</INF> response to reductions in ammonia
emissions would be relatively small<INF>,</INF> the demonstration that
the potential reductions from additional control measures that are not
currently being implemented would be below 30 percent, and the current
limited research in key areas of ammonia controls--and that it does not
pre-determine the outcome of significance determinations of precursors
in the future.
b. SO<INF>X</INF>
For SO<INF>X</INF>, the 2018 PM<INF>2.5</INF> Plan's sensitivity
estimates for 2013 are well below the EPA's recommended threshold for
both the 30 percent and 70 percent emission reduction scenarios and are
even negative for some monitoring sites. Given those results and the
steady SO<INF>X</INF> emission levels over 2013 to 2023 (as opposed to
increases), the EPA agrees with the State's conclusion that the 2013
modeled sensitivities provide a sufficient basis for the SO<INF>X</INF>
precursor demonstration. The supplemental results provided by the State
for 2020 and 2024 support this conclusion.
Therefore, based on these modeled ambient PM<INF>2.5</INF>
responses to SO<INF>X</INF> emissions reductions in the San Joaquin
Valley, and on the facts and circumstances of the area, the EPA
proposes to approve the State's demonstration that SO<INF>X</INF>
emissions do not contribute significantly to ambient PM<INF>2.5</INF>
levels that exceed the 1997 annual PM<INF>2.5</INF> NAAQS in the San
Joaquin Valley. We note that this proposed determination is specific to
the facts and circumstances of this particular plan and that it does
not pre-determine the outcome of significance determinations of
precursors in the future.
c. VOC
For VOC, the State found that the ambient PM<INF>2.5</INF> response
to VOC emissions reductions were generally
[[Page 45296]]
below the EPA's recommended contribution threshold of 0.2 [mu]g/m\3\,
and predicted an increase in ambient PM<INF>2.5</INF> levels in
response to VOC reductions (i.e., a disbenefit) at 2 out of 15
monitoring sites in 2020, and at 11 out 15 sites in 2024. Only for a 70
percent emissions reduction for the 2013 base year did the State
predict the ambient PM<INF>2.5</INF> response to be above the threshold
at a majority of sites.\194\
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\194\ 2018 PM<INF>2.5</INF> Plan, Appendix G, tables 10 and 11.
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The EPA has evaluated and agrees with the State's determination in
the 2018 PM<INF>2.5</INF> Plan that the modeling for future years is
more representative of conditions in the San Joaquin Valley than the
2013 modeling for sensitivity-based analyses and the State's resulting
conclusion that the contribution from VOC emissions is not significant.
The EPA agrees that the 8.6 percent decrease in VOC emissions from 2013
to 2020 and the 9.2 percent projected decrease from 2013 to 2024 favors
reliance on the future year modeling results. Furthermore, there is a
large decrease in NO<INF>X</INF> emissions over this period, as
discussed in Section IV.B.2 of this proposed rule, that affects the
atmospheric chemistry with respect to ambient PM<INF>2.5</INF>
formation from VOC emissions. The 9.2 percent VOC emissions reductions
and the vast majority of NO<INF>X</INF> emissions reductions are
expected to result from baseline measures already in effect. Therefore,
we conclude that it is reasonable to rely on future year 2020 or 2024
modeled responses to VOC emissions reductions. The EPA also concludes
that the State provided a reasonable explanation for the VOC emissions
reduction disbenefit and evidence that it occurs in the San Joaquin
Valley.
For these reasons, we propose to approve the State's demonstration
that VOC emissions do not contribute significantly to ambient
PM<INF>2.5</INF> levels that exceed the 1997 annual PM<INF>2.5</INF>
NAAQS in the San Joaquin Valley. We note that this proposed
determination is specific to the facts and circumstances of this
particular plan and that it does not pre-determine the outcome of
significance determinations of precursors in the future.
C. Attainment Plan Control Strategy
1. Statutory and Regulatory Requirements
Section 189(b)(1)(B) of the Act requires for any Serious
PM<INF>2.5</INF> nonattainment area that the state submit provisions to
assure that best available control measures (BACM), including controls
that reflect best available control technology (BACT), for the control
of PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors shall be
implemented no later than four years after the date the area is
reclassified as a Serious area. The EPA has defined BACM in the
PM<INF>2.5</INF> SIP Requirements Rule to mean ``any technologically
and economically feasible control measure that can be implemented in
whole or in part within four years after the date of reclassification
of a Moderate PM<INF>2.5</INF> nonattainment area to Serious and that
generally can achieve greater permanent and enforceable emissions
reductions in direct PM<INF>2.5</INF> emissions and/or emissions of
PM<INF>2.5</INF> plan precursors from sources in the area than can be
achieved through the implementation of RACM on the same source(s). BACM
includes best available control technology (BACT).'' \195\
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\195\ 40 CFR 51.1000 (definitions). In longstanding guidance,
the EPA has similarly defined BACM to mean, ``among other things,
the maximum degree of emissions reduction achievable for a source or
source category, which is determined on a case-by-case basis
considering energy, environmental, and economic impacts.'' General
Preamble Addendum, 42010, 42013.
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Because the 2015 Serious area attainment date has passed, and the
EPA found that the area failed to attain by the Serious area attainment
date, we are evaluating the submission for compliance with the BACM/
BACT requirements now, in conjunction with the State's SIP submission
intended to meet both the Serious area and section 189(d) plan
requirements.
The EPA generally considers BACM a control level that goes beyond
existing RACM-level controls, for example by expanding the use of RACM
controls or by requiring preventative measures instead of
remediation.\196\ Indeed, because states are required to implement BACM
and BACT when a Moderate nonattainment area is reclassified as Serious
due to its inability to attain the NAAQS through implementation of
``reasonable'' measures, it is logical that ``best'' control measures
should represent a more stringent and potentially more technologically
advanced or more costly level of control.\197\ If RACM and RACT level
controls of emissions have been insufficient to reach attainment, then
the CAA title I, part D, subpart 4 provisions for PM<INF>2.5</INF>
nonattainment plans contemplate the implementation of more stringent
controls, controls on more sources, or other adjustments to the control
strategy are necessary to attain the NAAQS in the area. Thus, BACM/BACT
determinations are to be ``generally independent'' of attainment for
purposes of implementing the PM<INF>2.5</INF> NAAQS.\198\
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\196\ 81 FR 58010, 58081 and General Preamble Addendum, 42011,
42013.
\197\ Id. and General Preamble Addendum, 42009-42010.
\198\ PM<INF>2.5</INF> SIP Requirements Rule, 58081-58082. See
also, General Preamble Addendum, 42011.
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Under the PM<INF>2.5</INF> SIP Requirements Rule, those control
measures that otherwise meet the definition of BACM/BACT but ``can only
be implemented in whole or in part beginning four years after
reclassification'' are referred to as ``additional feasible measures.''
\199\ In accordance with the requirements of CAA section 172(c)(6), a
Serious area plan must include any additional feasible measures to
control emissions of direct PM<INF>2.5</INF> and PM<INF>2.5</INF>
precursors that are necessary and appropriate to provide for attainment
of the relevant NAAQS as expeditiously as practicable and no later than
the applicable attainment date.\200\
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\199\ 40 CFR 51.1000, 40 CFR 51.1010(a)(4)(ii).
\200\ Because the Serious area attainment year has passed and
the area failed to attain by the Serious area attainment date, we
will evaluate the BACM/BACT and additional feasible measure analysis
for the Serious area plan with respect to the current section 189(d)
projected attainment date of December 31, 2023.
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Consistent with longstanding guidance provided in the General
Preamble Addendum, the preamble to the PM<INF>2.5</INF> SIP
Requirements Rule discusses the following steps for states to follow to
identify and select emission controls needed to meet the BACM/BACT and
additional feasible measures requirements of 40 CFR 51.1010:
(1) Develop a comprehensive emissions inventory of all sources of
PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors from major and non-
major stationary point sources, area sources, and mobile sources;
(2) Identify potential control measures for all sources or source
categories of emissions of PM<INF>2.5</INF> and relevant
PM<INF>2.5</INF> plan precursors;
(3) Determine whether an available control measure or technology is
technologically feasible;
(4) Determine whether an available control measure or technology is
economically feasible; and
(5) Determine the earliest date by which a control measure or
technology can be implemented in whole or in part.\201\
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\201\ 81 FR 58010, 58083-58085.
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The EPA allows states to consider factors such as a source's
processes and operating procedures, raw materials, physical plant
layout, and potential environmental effects such as increased water
pollution, waste disposal, and energy requirements when considering
technological feasibility.\202\ For purposes of evaluating economic
[[Page 45297]]
feasibility, the EPA allows states to consider factors such as the
capital costs, operating and maintenance costs, and cost effectiveness
(i.e., cost per ton of pollutant reduced by a measure or technology)
associated with the measure or control.\203\ For any potential control
measure identified through the process described above that is
eliminated from consideration, states are required to provide detailed
written justification for doing so on the basis of technological or
economic feasibility, including how its criteria for determining such
feasibility are more stringent than those used for determining RACM/
RACT.\204\
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\202\ 40 CFR 51.1010(a)(3)(i).
\203\ 40 CFR 51.1010(a)(3)(ii).
\204\ 40 CFR 51.1010(a)(3)(iii).
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Once these analyses are complete, the state must use this
information to develop enforceable control measures for all relevant
source categories in the nonattainment area and submit them to the EPA
for evaluation as SIP provisions to meet the basic requirements of CAA
section 110 and any other applicable substantive provisions of the Act.
The EPA is using these steps as guidelines in the evaluation of the
BACM and BACT measures and related analyses in the SJV PM<INF>2.5</INF>
Plan. Furthermore, because the EPA has not previously taken action to
approve the California SIP as meeting the subpart 4 Moderate area
planning requirements under CAA section 189 for the 1997 annual
PM<INF>2.5</INF> NAAQS for the San Joaquin Valley area, the EPA is
reviewing the SJV PM<INF>2.5</INF> Plan for compliance with those
requirements.\205\
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\205\ The EPA does not normally conduct a separate evaluation to
determine whether a Serious area plan's measures also meet the RACM
requirements. As explained in the General Preamble Addendum, we
interpret the BACM requirement as generally subsuming the RACM
requirement--i.e., if we determine that the measures are indeed the
``best available,'' we have necessarily concluded that they are
``reasonably available.'' (General Preamble Addendum, 42010).
Therefore, a separate analysis to determine if the measures
represent a RACM level of control is not necessary. A proposed
approval of a Plan's provisions concerning implementation of BACM is
also a proposed finding that the Plan provides for the
implementation of RACM.
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The overarching requirement for the CAA section 189(d) attainment
control strategy is that it provides for attainment of the NAAQS as
expeditiously as practicable.\206\ The control strategy must include
any additional measures (beyond those already adopted in previous
nonattainment plans for the area as RACM/RACT or BACM/BACT) that are
needed for the area to attain expeditiously. This includes reassessing
any measures previously rejected during the development of any Moderate
area or Serious area attainment plan control strategy.\207\ The state
must also demonstrate that it will, at a minimum, achieve an annual
five percent reduction in emissions of direct PM<INF>2.5</INF> or any
PM<INF>2.5</INF> plan precursor from sources in the area, based on the
most recent emissions inventory for the area.\208\
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\206\ 81 FR 58010, 58100.
\207\ 40 CFR 50.1010(c)(2)(ii).
\208\ CAA section 189(d) and 40 CFR 51.1010(c).
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In the PM<INF>2.5</INF> SIP Requirements Rule, the EPA clarified
its interpretation of the statutory language in CAA section 189(d)
requiring a state to submit a new attainment plan to achieve annual
reductions ``from the date of such submission until attainment,'' to
mean annual reductions beginning from the due date of such submission
until the new projected attainment date for the area based on the new
or additional control measures identified to achieve at least five
percent emissions reductions annually.\209\ This interpretation is
intended to make clear that even if a state is late in submitting its
CAA section 189(d) plan, the area must still achieve its annual five
percent emissions reductions beginning from the date by which the state
was required to make its CAA section 189(d) submission, not by some
later date. Because the deadline for California to submit a section
189(d) plan for the 1997 annual PM<INF>2.5</INF> NAAQS in the San
Joaquin Valley was December 31, 2016, one year after the December 31,
2015 attainment date for these NAAQS under CAA section 188(c)(2), the
starting point for the five percent emissions reduction requirement
under section 189(d) for this area is 2017.
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\209\ 81 FR 58010, 58101.
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2. Summary of the State's Submission and the EPA's Evaluation and
Proposed Action
a. Control Strategy
i. Baseline Measures
The control strategy in the SJV PM<INF>2.5</INF> Plan is based
largely on ongoing emissions reductions from baseline control measures,
which amount to approximately 98.2 percent of total NO<INF>X</INF>
emissions reductions and 93.3 percent of total direct PM<INF>2.5</INF>
emissions reductions modeled to result in attainment of the 1997 annual
PM<INF>2.5</INF> NAAQS in the San Joaquin Valley.<SUP>210 211</SUP> As
we use the term here, baseline measures are State and District
regulations adopted prior to the development of the 2018
PM<INF>2.5</INF> Plan that continue to achieve emissions reductions
through the projected 2023 attainment year for the 1997 annual
PM<INF>2.5</INF> NAAQS and beyond. The State describes these baseline
measures in the 15 [mu]g/m\3\ SIP Revision in Chapter 4 (``Attainment
Strategy for PM<INF>2.5</INF>'') \212\ and Appendix D (``Mobile Source
Control Measure Analyses''), and in Appendix C (``Stationary Source
Control Measure Analyses'') of the 2018 PM<INF>2.5</INF> Plan. The
State incorporates reductions generated by these baseline measures into
the projected baseline inventories, and reductions resulting from
District measures are individually quantified in Appendix C. Table 4
provides a summary of the 2013 base year emissions and the reductions
from baseline measures, additional State measures, and additional
District measures that the Plan projects will result in attainment of
the 1997 annual PM<INF>2.5</INF> NAAQS in the San Joaquin Valley by
December 31, 2023.
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\210\ Because the 2015 Serious area attainment date has passed,
and the EPA found that the area failed to attain by the Serious area
attainment date, we are evaluating the control strategy for the
Serious area requirements based on the timeline associated with the
current section 189(d) projected attainment date of December 31,
2023.
\211\ The EPA calculated these percentages as follows: annual
average baseline NO<INF>X</INF> reductions from 2013 to 2023 are
163.6 tpd of 166.6 tpd modeled to result in attainment (98.2
percent) and annual average baseline direct PM<INF>2.5</INF>
reductions are 4.2 tpd of 4.5 tpd modeled to result in attainment
(93.3 percent). 2018 PM<INF>2.5</INF> Plan, Appendix B; and 15
[mu]g/m\3\ SIP Revision, Chapter 4 and Appendix K.
\212\ 15 [mu]g/m\3\ SIP Revision, Chapter 4, Table 4-2.
Table 4--Summary of the SJV PM2.5 Plan's Annual Average Emission Reductions To Attain the 1997 Annual PM2.5
NAAQS by December 31, 2023
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% of 2013 base Direct PM2.5 % of 2013 base
NOX (tpd) year NOX (tpd) year PM2.5
emissions emissions
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A............................. 2013 Base Year 317.2 .............. 62.5 ..............
Emissions.
B............................. Baseline Measure 163.6 51.6 4.2 6.7
Emissions
Reductions
(2013-2023).
C............................. Additional CARB 3.0 0.9 0.1 0.2
Measures.
[[Page 45298]]
D............................. Additional 0.0 0.0 0.2 0.3
District
Measures.
E............................. Total 2013-2023 166.6 52.5 4.5 7.2
Emissions
Reductions
(B+C+D).
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Source: 2018 PM2.5 Plan, Appendix B, tables B-1 and B-2; and 15 [mu]g/m\3\ SIP Revision, Appendix K, Table 32.
In the SJV PM<INF>2.5</INF> Plan, the State explains that mobile
sources emit over 85 percent of the NO<INF>X</INF> emissions in the San
Joaquin Valley and that CARB has adopted and amended regulations to
reduce public exposure to emissions from diesel vehicles and engines,
which include direct PM<INF>2.5</INF> and NO<INF>X</INF>, from ``fuel
sources, freight transport sources like heavy-duty diesel trucks,
transportation sources like passenger cars and buses, and non-road
sources like large construction equipment.'' \213\
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\213\ 15 [mu]g/m\3\ SIP Revision, Chapter 4, p. 4-9. For CARB's
BACM analysis for mobile source measures, see 15 [mu]g/m\3\ SIP
Revision, Appendix D, including analyses for on-road light-duty
vehicles and fuels (starting on page D-17), on-road heavy-duty
vehicles and fuels (starting on page D-35), and non-road sources
(starting on page D-64).
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Given the need for substantial emissions reductions from mobile and
area sources to meet the NAAQS in California nonattainment areas, the
State of California has developed stringent control measures for on-
road and non-road mobile sources and the fuels that power them.
California has unique authority under CAA section 209 (subject to a
waiver by the
[…truncated; see source link]Indexed from Federal Register on July 14, 2023.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.