Proposed Rule2026-22055
Air Plan Approval; California; Reasonable Further Progress Plan for the Coachella Valley Ozone Nonattainment Area
Primary source
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Published
October 29, 2026
Issuing agencies
Environmental Protection Agency
Abstract
The U.S. Environmental Protection Agency (EPA or "the Agency") is proposing to approve a state implementation plan (SIP) revision from the State of California to meet the Clean Air Act (CAA) "Extreme" nonattainment area requirements for the Riverside County (Coachella Valley), California ozone nonattainment area ("Coachella Valley") for the 2008 8-hour ozone national ambient air quality standards (NAAQS or "standards"). Specifically, the Agency is proposing to approve the reasonable further progress (RFP) demonstration and associated emissions inventory and motor vehicle emissions budgets ("budgets") for the Coachella Valley.
Full Text
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<title>Federal Register, Volume 91 Issue 208 (Thursday, October 29, 2026)</title>
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[Federal Register Volume 91, Number 208 (Thursday, October 29, 2026)]
[Proposed Rules]
[Pages 68059-68067]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-22055]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R09-OAR-2026-7129; FRL-13593-01-R9]
Air Plan Approval; California; Reasonable Further Progress Plan
for the Coachella Valley Ozone Nonattainment Area
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The U.S. Environmental Protection Agency (EPA or ``the
Agency'') is proposing to approve a state implementation plan (SIP)
revision from the State of California to meet the Clean Air Act (CAA)
``Extreme'' nonattainment area requirements for the Riverside County
(Coachella Valley), California ozone nonattainment area (``Coachella
Valley'') for the 2008 8-hour ozone national ambient air quality
standards (NAAQS or ``standards''). Specifically, the Agency is
proposing to approve the reasonable further progress (RFP)
demonstration and associated emissions inventory and motor vehicle
emissions budgets (``budgets'') for the Coachella Valley.
DATES: Written comments must arrive on or before November 30, 2026.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2026-7129 at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. For comments submitted at
<a href="http://Regulations.gov">Regulations.gov</a>, follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
<a href="http://Regulations.gov">Regulations.gov</a>. The EPA may publish any comment received to its public
docket. Do not submit electronically any information you consider to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Multimedia submissions (audio,
video, etc.) must be accompanied by a written comment. The written
comment is considered the official comment and should include
discussion of all points you wish to make. The EPA will generally not
consider comments or comment contents located outside of the primary
submission (i.e., on the web, cloud, or other file sharing system). For
additional submission methods, please contact the person identified in
the FOR FURTHER INFORMATION CONTACT section. For the full EPA public
comment policy, information about CBI or multimedia submissions, and
general guidance on making effective comments, please visit <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>. If you need assistance in a
language other than English or if you are a person with a disability
who needs a reasonable accommodation at no cost to you, please contact
the person identified in the FOR FURTHER INFORMATION CONTACT section.
FOR FURTHER INFORMATION CONTACT: Andrew Ledezma, EPA Region IX, 75
Hawthorne Street, San Francisco, CA 94105; telephone number: (415) 972-
3985; email address: <a href="/cdn-cgi/l/email-protection#dcb0b9b8b9a6b1bdf2bdb2b8aeb9ab9cb9acbdf2bbb3aa"><span class="__cf_email__" data-cfemail="b0dcd5d4d5caddd19ed1ded4c2d5c7f0d5c0d19ed7dfc6">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: Throughout this proposed rule, the use
[[Page 68060]]
of ``we,'' ``us,'' or ``our'' is intended to refer to the EPA. We use
multiple abbreviations and terms in this proposed rule. While this list
may not be exhaustive, for ease of reading and for reference purposes,
the EPA defines the following terms and acronyms here:
AERR--Air Emissions Reporting Requirements
EPA--Environmental Protection Agency
CAA--Clean Air Act
CARB--California Air Resources Board
CBI--Confidential Business Information
FHWA--Federal Highway Administration
FTA--Federal Transit Administration
NAA--Nonattainment Area
NAAQS--National Ambient Air Quality Standards
NO<INF>X</INF>--Oxides of Nitrogen
RACT--Reasonably Available Control Technology
RFP--Reasonable Further Progress
ROP--Rate of Progress
SCAQMD--South Coast Air Quality Management District
SRR--SIP Requirements Rule
TPD--Tons per Day
VMT--Vehicle Miles Traveled
VOC--Volatile Organic Compounds
Table of Contents
I. Executive Summary
A. What proposed action is the EPA taking?
B. What is the legal authority and what are the requirements?
II. Background
A. Ozone Standards, Area Designations, and SIPs
B. The Coachella Valley Nonattainment Area
C. CAA and Regulatory Requirements for 2008 8-Hour Ozone
Nonattainment Area SIPs
III. Clean Air Act Procedural Requirements for Adoption and
Submission of SIP Revisions
A. Summary of Submissions
B. Clean Air Act Procedural Requirements for Adoption and
Submission of SIP Revisions
IV. Evaluation of the 2022 Coachella Valley RFP Plan
A. Emissions Inventories
B. Reasonable Further Progress Demonstration
C. Motor Vehicle Emissions Budgets for Transportation Conformity
V. Proposed Action
VI. Statutory and Executive Order Reviews
I. Executive Summary
A. What proposed action is the EPA taking?
The EPA is proposing to approve the RFP demonstration and
associated emissions inventory and budgets for the Coachella Valley
2008 ozone NAAQS Extreme nonattainment area.
B. What is the legal authority and what are the requirements?
Under CAA section 109, the EPA promulgates NAAQS for criteria air
pollutants, such as ozone. In 2008, the EPA revised the ozone NAAQS by
setting the acceptable level of ozone in the ambient air at 0.075 parts
per million (ppm) averaged over an 8-hour period.
Requirements for an emissions inventory for nonattainment areas are
specified in CAA section 172(c)(3). CAA section 172(c)(3) requires that
each nonattainment plan SIP submission include a ``comprehensive,
accurate, current inventory of actual emissions from all sources of the
relevant pollutant or pollutants in [the] area.''
Requirements for RFP for ozone nonattainment areas are specified in
CAA sections 172(c)(2), 182(b)(1), and 182(c)(2)(B). CAA section
172(c)(2) requires that plans for nonattainment areas provide for RFP,
which is defined as such annual incremental reductions in emissions of
the relevant air pollutant as are required under part D (``Plan
Requirements for Nonattainment Areas'') or that may reasonably be
required by the EPA for the purpose of ensuring attainment of the
applicable NAAQS by the applicable attainment date. CAA section
182(b)(1) specifically requires that ozone nonattainment areas that are
classified as ``Moderate'' or above demonstrate a 15 percent reduction
in volatile organic compounds (VOC) over an initial six-year period.
Requirements for conformity are specified in CAA section 176(c).
CAA section 176(c) requires Federal actions in nonattainment and
maintenance areas to conform to the SIP's goals of eliminating or
reducing the severity and number of violations of the NAAQS and
achieving timely attainment of the standards.
II. Background
A. Ozone Standards, Area Designations, and SIPs
Ground-level ozone pollution is formed from the reaction of VOC and
oxides of nitrogen (NO) in the presence of sunlight.\1\ These two
pollutants, referred to as ozone precursors, are emitted by many types
of sources, including on-and off-road motor vehicles and engines, power
plants and industrial facilities, and smaller area sources such as lawn
and garden equipment and paints.
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\1\ The State of California typically refers to reactive organic
gases (ROG) in its ozone-related submissions since VOC in general
can include both reactive and unreactive gases. However, since ROG
and VOC inventories pertain to common chemical species (e.g.,
benzene, xylene), we refer to this set of gases as VOC in this
proposed rule.
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Under CAA section 109, the EPA promulgates NAAQS for criteria air
pollutants, such as ozone. The Agency promulgated NAAQS for ozone in
1979 and 1997.\2\ In 2008, the EPA revised the ozone NAAQS by setting
the acceptable level of ozone in the ambient air at 0.075 ppm averaged
over an 8-hour period.\3\ Although the Agency further revised the 8-
hour ozone NAAQS to 0.070 ppm in 2015,\4\ this action relates to the
requirements for the 2008 ozone NAAQS.
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\2\ The ozone NAAQS promulgated in 1979 was 0.12 parts per
million (ppm) averaged over a 1-hour period. See 44 FR 8202 (Feb. 8,
1979). The ozone NAAQS promulgated in 1997 was 0.08 ppm averaged
over an 8-hour period. See 62 FR 38856 (July 18, 1997).
\3\ See 73 FR 16436 (Mar. 27, 2008).
\4\ See 80 FR 65292 (Oct. 26, 2015).
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Following promulgation of a new or revised NAAQS, the EPA is
required under CAA section 107(d) to designate areas of the country as
attaining or not attaining the NAAQS. Ozone nonattainment areas are
further classified under CAA section 181 according to the severity of
the ozone pollution problem, with classifications ranging from
``Marginal'' to ``Extreme.'' State planning and emissions control
requirements for ozone are determined, in part, by the nonattainment
area's classification. In 2012, the EPA designated the Coachella Valley
as nonattainment for the 2008 ozone NAAQS and the area was classified
as ``Severe-15.'' \5\
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\5\ 77 FR 30088 (May 21, 2012).
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In 2020, the EPA approved portions of two SIP revisions, the
``Final 2016 Air Quality Management Plan'' and the ``2018 Updates to
the California State Implementation Plan,'' for the Coachella Valley
area.\6\ Collectively, we referred to the relevant portions of the two
SIP revisions as the ``2016 Coachella Valley Ozone SIP.'' The 2016
Coachella Valley Ozone SIP addressed ozone nonattainment area
requirements, including the requirements for an emissions inventory,
emissions statement rule, attainment demonstration, RFP, reasonably
available control measures, contingency measures, and budgets. The
Agency approved the 2016 Coachella Valley Ozone SIP as meeting all the
applicable Severe-15 ozone nonattainment area requirements except for
the contingency measure requirements, for which the EPA deferred
action.
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\6\ 85 FR 57714 (Sep. 16, 2020).
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On March 8, 2023, the EPA granted a request from California to
reclassify the
[[Page 68061]]
Coachella Valley as Extreme for the 2008 ozone NAAQS.\7\ The SIP
revisions that are the subject of today's proposed action address
specific Extreme nonattainment area requirements that apply to the
Coachella Valley for the 2008 ozone NAAQS.
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\7\ 88 FR 14291 (Mar. 8, 2023).
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B. The Coachella Valley Nonattainment Area
The Coachella Valley is located within Riverside County, and its
boundaries generally align with the Riverside County portion of the
Salton Sea Air Basin.\8\ The Coachella Valley is downwind from the
South Coast Air Basin and is subject to significant transport of ozone
from that area; both ozone nonattainment areas are regulated by the
South Coast Air Quality Management District (SCAQMD or ``District'').
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\8\ For a precise description of the geographic boundaries of
the Coachella Valley, see 40 CFR 81.305.
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C. CAA and Regulatory Requirements for 2008 8-Hour Ozone Nonattainment
Area SIPs
States must implement the 2008 ozone standards under Title 1, part
D of the CAA, which includes CAA sections 171 through 179B of subpart 1
(``Nonattainment Areas in General'') and CAA sections 181 through 185
of subpart 2 (``Additional Provisions for Ozone Nonattainment Areas'').
To assist States in developing effective plans to address ozone
nonattainment problems, the EPA has issued a SIP Requirements Rule for
the 2008 ozone standards (``2008 Ozone SRR'') that addresses
implementation of the 2008 standards, including attainment dates,
requirements for emissions inventories, and RFP demonstrations, as well
as the transition from the 1997 ozone standards to the 2008 ozone
standards and associated anti-backsliding requirements.\9\ The 2008
Ozone SRR is codified at 40 CFR part 51, subpart AA. We discuss the CAA
and regulatory requirements for the elements of 2008 ozone plans
relevant to this proposal in more detail in section IV of this
document.
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\9\ See 80 FR 12264 (Mar. 6, 2015).
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The EPA's 2008 Ozone SRR was challenged, and on February 16, 2018,
the U.S. Court of Appeals for the D.C. Circuit (``D.C. Circuit'')
published its decision in South Coast Air Quality Management District
v. EPA \10\ (``South Coast II'') \11\ vacating portions of the 2008
Ozone SRR. The only aspect of the South Coast II decision that affects
this proposed action is the vacatur of the alternative baseline year
for RFP plans. More specifically, the 2008 Ozone SRR required States to
develop the baseline emissions inventory for RFP plans using emissions
data for the most recent calendar year for which States submit a
triennial inventory to the Agency under subpart A (``Air Emissions
Reporting Requirements'') of 40 CFR part 51, which for the 2008 ozone
NAAQS was 2011. However, the 2008 Ozone SRR allowed States to use an
alternative year, between 2008 and 2012, for the baseline emissions
inventory provided that the State demonstrated why the alternative
baseline year was appropriate. In the South Coast II decision, the D.C.
Circuit vacated the provisions of the 2008 Ozone SRR that allowed
States to use an alternative baseline year for demonstrating RFP.
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\10\ South Coast Air Quality Management District v. EPA, 882
F.3d 1138 (D.C. Cir. 2018).
\11\ The term ``South Coast II'' is used in reference to the
2018 court decision to distinguish it from a decision published in
2006 also referred to as ``South Coast.'' The earlier decision
involved a challenge to the EPA's Phase 1 implementation rule for
the 1997 ozone standard. South Coast Air Quality Management Dist. v.
EPA, 472 F.3d 882 (D.C. Cir. 2006).
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III. Clean Air Act Procedural Requirements for Adoption and Submission
of SIP Revisions
A. Summary of Submissions
On December 7, 2022, the California Air Resources Board (CARB)
submitted the ``Coachella Valley 75 ppb 8-Hour Ozone Reasonable Further
Progress State Implementation Plan'' (``2022 Coachella Valley RFP
Plan'' or ``Plan'') as a revision to the California SIP, along with a
request to reclassify the Coachella Valley to Extreme with respect to
the 2008 ozone NAAQS.\12\ On March 8, 2023, the EPA took action to
reclassify the Coachella Valley to Extreme for the 2008 ozone
NAAQS.\13\ Today's proposed action addresses only the RFP demonstration
and associated emissions inventories and budgets in the 2022 Coachella
Valley RFP Plan for the 2008 ozone NAAQS.
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\12\ See letter dated Dec. 6, 2022, from Steven S. Cliff,
Executive Officer, CARB, to Martha Guzman, Regional Administrator,
EPA Region 9.
\13\ 88 FR 14291 (Mar. 8, 2023).
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CARB's submission consists of documents prepared by the District
(i.e., the 2022 Coachella Valley RFP Plan, District submittal cover
letter, and District governing board resolution) and by CARB (i.e., the
CARB Staff Report and Appendices and CARB board resolution adopting the
2022 Coachella Valley RFP Plan as a SIP revision).\14\ The Plan
addresses the Extreme area nonattainment requirements for RFP and the
associated emissions inventory and budgets for the Coachella Valley.
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\14\ See four enclosures to the Dec. 6, 2022 letter from CARB to
EPA Region 9: (I) District submission, including a letter from Wayne
Nastri, Executive Officer, SCAQMD, to Steven S. Cliff, Ph.D.,
Executive Officer, CARB, and four attachments titled: (1) the
District Governing Board Package, (2) Final Request to Reclassify
Coachella Valley for the 2008 8-Hour Ozone Standard and Related SIP
Elements Required to Update the Motor Vehicle Emissions Budgets, (3)
Approved Governing Board Resolution, and (4) Proof of Publication
for Notice of Public Hearing; (II) CARB Evidence of Public Notice
and Transcript; (III) CARB Staff Report; and (IV) CARB Resolution
22-18 to adopt the Coachella Valley RFP Plan.
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B. Clean Air Act Procedural Requirements for Adoption and Submission of
SIP Revisions
CAA sections 110(a)(1) and (2) and 110(l) require a State to
provide reasonable public notice and opportunity for public hearing
prior to the adoption and submission of a SIP or SIP revision. To meet
these procedural requirements, 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.
The District Governing Board adopted the 2022 Coachella Valley RFP
Plan on November 4, 2022, following a public comment period and
hearing. CARB adopted the 2022 Coachella Valley RFP Plan as a revision
to the California SIP on November 17, 2022, following a public hearing.
The District and CARB have satisfied the applicable statutory and
regulatory requirements for reasonable public notice and hearing prior
to the adoption and submission of the 2022 Coachella Valley RFP Plan.
Therefore, we find that the Plan meets the procedural requirements for
public notice and hearing in CAA sections 110(a) and 110(l) and 40 CFR
51.102.
IV. Evaluation of the 2022 Coachella Valley RFP Plan
A. Emissions Inventories
1. Statutory and Regulatory Requirements
CAA section 172(c)(3) requires that each nonattainment plan SIP
submission include a ``comprehensive, accurate, current inventory of
actual emissions from all sources of the relevant pollutant or
pollutants in [the] area.'' The accounting required by this section
provides a ``base year'' inventory that serves as the starting point
for attainment demonstration air quality modeling, for assessing RFP,
and for determining the need for additional SIP control measures. EPA
regulations require that the base year be consistent
[[Page 68062]]
with the baseline year for the RFP demonstration, which is the most
recent calendar year for which a complete triennial inventory is
required to be submitted to the Agency under the Air Emissions
Reporting Requirements (AERR).\15\
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\15\ See 2008 Ozone SRR at 40 CFR 51.1115(a) and the Air
Emissions Reporting Requirements at 40 CFR part 51, subpart A.
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The EPA has issued guidance on the development of base year and
future year emissions inventories for ozone and other pollutants.\16\
Emissions inventories for ozone must include emissions of VOC and
NO<INF>X</INF> and represent emissions for a typical ozone season
weekday.\17\ States should include documentation explaining how they
calculated emissions data. In estimating mobile source emissions,
States should use the latest emissions models and planning assumptions
available at the time they develop the SIP submission.\18\
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\16\ See ``Emissions Inventory Guidance for Implementation of
Ozone and Particulate Matter National Ambient Air Quality Standards
(NAAQS) and Regional Haze Regulations'' (``EI Guidance''), EPA-454/
B-17-002, May 2017.
\17\ 40 CFR 51.1115(a) and (c), and 40 CFR 51.1100(bb) and (cc).
\18\ See 80 FR 12264, 12290 (Mar. 6, 2015).
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2. Summary of the State's Submission
The 2022 Coachella Valley RFP Plan includes a 2011 base year
emissions inventory based on actual emissions to meet the requirements
of CAA sections 172(c)(3) and 182(a)(1). The Plan also includes
projected inventories for the years 2017, 2020, 2023, 2026, 2029, and
the Coachella Valley's 2031 Extreme attainment year to meet the
requirements of CAA section 182(c)(2)(B).
This inventory includes VOC and NO<INF>X</INF> emissions because
these pollutants are the precursors to ozone formation and includes
emissions across all source categories during an ozone season day as
defined in 40 CFR 51.1100(cc). 40 CFR 51.1115(c) requires emissions
values included in the base year inventory to be actual ozone season
day emissions as defined by 40 CFR 51.1100(q). While the Coachella
Valley has a year-round ozone season, the 2022 Coachella Valley RFP
Plan identifies summer, defined as May through October, as the time
when the highest concentrations of ozone occur.
A description of the base year and projected year emissions
inventories can be found in Chapter 5 of the Plan. The complete
emissions inventory and documentation are found in Appendix I (``Summer
Planning Emissions Inventory by Major Source Category''), and Appendix
II (``Emissions Inventory Methodology for the 2008 8-Hour Ozone Extreme
Area Plan Using CEPAM 2022 v1.01'') of the Plan.
VOC and NO<INF>X</INF> emissions can be grouped into two general
source categories: emissions from stationary sources and emissions from
mobile sources. Stationary sources can be further divided into
``point'' and ``area'' sources. Point sources typically refer to
permitted facilities that have one or more identified and fixed pieces
of equipment and emissions point. Per the AERR, permitted facilities
were required to report their actual emissions to the District by the
facility operators through the calendar year 2011. Stationary area
sources are many smaller point sources and include sources that have
internal combustion engines and gasoline dispensing facilities (gas
stations). These sources are not inventoried individually; their
emissions are estimated as a group and reported as a single source
category. Area sources consist of widespread and numerous smaller
emission sources, such as small permitted facilities and households.
The mobile source category can be divided into two major
subcategories: ``on-road'' and ``off-road'' mobile sources. On-road
mobile sources include light-duty automobiles; light-duty, medium-duty,
and heavy-duty trucks; and motorcycles. Off-road mobile sources include
aircraft, locomotives, construction equipment, mobile equipment, and
recreational vehicles.
CARB and the District worked together to develop the emissions
inventories for the 2022 Coachella Valley RFP Plan. Data were provided
by CARB, the California Department of Transportation, the Department of
Motor Vehicles, the Department of Pesticide Regulation, the California
Energy Commission, and regional transportation agencies to develop
estimates of mobile and area source emissions. The emission estimates
for point sources reflect reported emissions, whereas estimates for
mobile and area sources are based on projections obtained through use
of emissions models and methodologies along with actual activity data
for 2011 (e.g., vehicle miles traveled). The District applied different
methodologies to estimate over sixty different types of individual
stationary sources. CARB and the District also reviewed the growth
profiles for point and area source categories and updated them as
necessary to ensure that the emission projections were based on data
that reflect historical trends, current conditions, and recent economic
and demographic forecasts.
CARB provided emission estimates for stationary sources, including
nonagricultural diesel engines, agricultural irrigation pumps,
laundering (dry cleaning), degreasing (solvents), oil and gas
production, and gasoline dispensing facilities. CARB and the District
estimated emissions for area sources, including consumer products,
pesticides/fertilizers, fireplaces, farming operations, and other
sources using models and associated methodologies.
CARB developed the emissions inventories for mobile sources. CARB
estimated on-road mobile sources emissions, which include passenger
vehicles, buses, and trucks, using their EMFAC2017 model.\19\ They
calculated on-road emissions by applying EMFAC2017 emission factors to
the transportation activity data provided by the Southern California
Association of Governments (SCAG) from their adopted 2020 Regional
Transportation Plan. CARB estimated off-road mobile source emissions
using either newer category-specific models or, where a new model was
not available, the OFFROAD2007 model.
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\19\ The EPA approved EMFAC2017 for use in SIP development and
transportation conformity in California at 84 FR 41717 (Aug. 15,
2019). While EMFAC2017 is not the most recently approved model in
California, it was the most recently approved model when this SIP
was developed.
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Table 1 of this document provides a summary of the Coachella Valley
2011 base year VOC and NO<INF>X</INF> emissions inventories, grouped by
major source category.
Table 1--Base Year Summer Average VOC and NOX Emissions in the 2022 Coachella Valley RFP Plan
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2011
Source category -------------------------------------------------
VOC (tpd) NOX (tpd)
----------------------------------------------------------------------------------------------------------------
Stationary and Area Sources................................... 5.9 1.0
[[Page 68063]]
On-Road Mobile Sources........................................ 5.6 19.0
Other Mobile Sources.......................................... 4.8 7.5
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Total..................................................... 16.3 27.5
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Source: 2022 Coachella Valley RFP Plan, Figures 5-1 and 5-2, and Appendix I.
For the purposes of the RFP demonstration, CARB developed projected
inventories from the 2011 base year. These inventories form the basis
of the RFP demonstration calculations and motor vehicle emissions
budgets that are discussed in sections IV.B and IV.C of this document.
In this section, we describe and evaluate the inventory projections to
determine whether they are appropriate for use in these SIP elements.
Stationary and area source emissions estimates were projected from
the base year using the California Emission Projection Analysis Model
(CEPAM 2022v1.01) and reflect expected growth trends for each source
category and emissions reductions due to adopted control measures.
Growth profiles for point and area sources are derived from surrogates,
such as economic activity, fuel usage, population, and housing units,
that best reflect the expected growth trends for each specific source
category.
Mobile sources were projected using the same model as was used for
the base year calculations, i.e., EMFAC2017. The EMFAC model predicts
activity rates and vehicle fleet turnover by vehicle model year. The
EMFAC model allows local inputs for certain parameters. In this case,
local vehicle activity inputs were provided by SCAG. Off-road mobile
sources are forecasted using a category-specific model, or, where a
category-specific model is not available, using CARB's OFFROAD2007
model.
Tables 2 and 3 of this document provide summaries of the Coachella
Valley VOC and NO<INF>X</INF> emissions inventories for RFP baseline
and milestone years, grouped by major source category.
Table 2--Summer Average VOC Emissions
[tpd]
----------------------------------------------------------------------------------------------------------------
Source category 2011 2023 2031
----------------------------------------------------------------------------------------------------------------
Stationary and Area Sources..................................... 5.9 6.8 7.6
On-Road Vehicles................................................ 5.6 2.6 2.2
Other Mobile.................................................... 4.8 3.3 3.1
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Total....................................................... 16.3 12.7 12.8
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Source: 2022 Coachella Valley RFP Plan, Figure 5-2 and Appendix I.
Table 3--Summer Average NOX Emissions
[tpd]
----------------------------------------------------------------------------------------------------------------
Source category 2011 2023 2031
----------------------------------------------------------------------------------------------------------------
Stationary and Area Sources..................................... 1 1.6 1.4
On-Road Vehicles................................................ 19 6 5.7
Other Mobile.................................................... 7.5 7.1 6.8
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Total....................................................... 27.5 14.6 13.9
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Source: 2022 Coachella Valley RFP Plan, Figure 5-1 and Appendix I.
For future-year projections, the EPA will approve a State plan that
takes emissions reduction credit for a control measure only if the
Agency has approved the measure as part of the SIP. Thus, to take
credit for the emissions reductions from newly adopted or amended CARB
and District rules for mobile and stationary sources, the related rules
must be approved by the EPA into the SIP. Appendix II of the 2022
Coachella Valley RFP Plan describes the CARB rules that were
incorporated into the on- and off-road future year inventories, along
with the calculation methodology by source category.\20\ Table 1 in
Appendix II of the 2022 Coachella Valley RFP Plan shows District rules
that were incorporated in the future year inventories, along with
information on the EPA's approval of these rules.
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\20\ Appendix II to the 2022 Coachella Valley RFP Plan, pages
II-4--II-9.
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3. The EPA's Review of the State's Submission
We have reviewed the base year and milestone year emissions
inventories in the 2022 Coachella Valley RFP Plan for the Coachella
Valley 2008 ozone nonattainment area for consistency with CAA
requirements and EPA guidance. First, we note that the inventories
include estimates for VOC and NO<INF>X</INF> for a typical ozone season
weekday and that CARB has provided adequate documentation explaining
how the
[[Page 68064]]
emissions are calculated. Second, we find that the 2011 base year
emissions inventories in the Plan reflect appropriate emissions models
and methodologies and therefore represent comprehensive, accurate, and
current inventories of actual emissions during that year. Further, we
find that CARB and the District have used the most recent planning and
activity assumptions, emissions models, and methodologies in developing
the RFP baseline and milestone year emissions inventories in the Plan.
Therefore, the EPA is proposing to approve the 2011 emissions
inventory as meeting the requirements for a base year inventory set
forth in CAA section 182(a)(1) and 40 CFR 51.1115. The projected
inventories start with the 2011 baseline and project out to 2031. The
Agency is proposing to find these inventories appropriate for use in
developing the RFP demonstration (see section IV.B of this document)
and the motor vehicle emissions budgets (see section IV.C of this
document) for the Coachella Valley for the 2008 ozone standards.
B. Reasonable Further Progress Demonstration
1. Statutory and Regulatory Requirements
Requirements for RFP for ozone nonattainment areas are specified in
CAA sections 172(c)(2), 182(b)(1), and 182(c)(2)(B). CAA section
172(c)(2) requires that plans for nonattainment areas provide for RFP,
which is defined as such annual incremental reductions in emissions of
the relevant air pollutant as are required under part D (``Plan
Requirements for Nonattainment Areas'') or that may reasonably be
required by the EPA for the purpose of ensuring attainment of the
applicable NAAQS by the applicable attainment date. CAA section
182(b)(1) specifically requires that ozone nonattainment areas that are
classified as Moderate or above demonstrate a 15 percent reduction in
VOC between the years of 1990 and 1996. The Agency has typically
referred to CAA section 182(b)(1) as the rate of progress (ROP)
requirement. For ozone nonattainment areas classified as Serious or
higher, CAA section 182(c)(2)(B) requires reductions averaged over each
consecutive 3-year period, beginning 6 years after the baseline year
until the attainment date, of at least 3 percent of baseline emissions
per year. The provisions in CAA section 182(c)(2)(B)(ii) allow an
amount less than 3 percent of such baseline emissions each year if the
State demonstrates to the EPA that the plan includes all measures that
can feasibly be implemented in the area in light of technological
achievability.
In the 2008 Ozone SRR, the EPA provided that areas classified as
Moderate or higher will have met the ROP requirements of CAA section
182(b)(1) if the area has a fully approved 15 percent ROP plan for the
1-hour or 1997 8-hour ozone NAAQS.\21\ For such areas, the Agency
interprets the RFP requirements of CAA section 172(c)(2) to require
areas classified as Moderate to provide a 15 percent emissions
reduction of ozone precursors within 6 years of the baseline year.
Areas classified as Serious or higher must meet the RFP requirements of
CAA section 182(c)(2)(B) by providing for an 18 percent reduction of
ozone precursors in the first 6-year period, and an average ozone
precursor emissions reduction of 3 percent per year for all remaining
3-year periods thereafter.\22\ The 2008 Ozone SRR allows substitution
of NO<INF>X</INF> reductions for VOC reductions to meet the CAA section
172(c)(2) and 182(c)(2)(B) RFP requirements.\23\
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\21\ 80 FR 12264, 12271 (Mar. 6, 2015).
\22\ Id.
\23\ Id.; 40 CFR 51.1110(a)(2)(i)(C) and 40 CFR
51.1110(a)(2)(ii)(B).
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Except as specifically provided in CAA sections 182(b)(1)(C) and
(D), emissions reductions from all SIP-approved, federally promulgated,
or otherwise SIP creditable measures that occur after the baseline year
are creditable for purposes of demonstrating that the RFP targets are
met.\24\ Because the EPA has determined that the passage of time has
caused the effect of certain exclusions to be de minimis, the RFP
demonstration is no longer required to calculate and specifically
exclude reductions from measures related to motor vehicle exhaust or
evaporative emissions promulgated by January 1, 1990; regulations
concerning Reid vapor pressure promulgated by November 15, 1990;
measures to correct previous RACT requirements; and measures required
to correct previous inspection and maintenance programs.\25\
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\24\ 40 CFR 51.1110(a)(5).
\25\ 40 CFR 51.1110(a)(7).
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The 2008 Ozone SRR requires the RFP baseline year to be the most
recent calendar year for which a complete triennial inventory was
required to be submitted to the EPA. For the purposes of developing RFP
demonstrations for the 2008 ozone NAAQS, the applicable triennial
inventory year is 2011. As discussed previously, the 2008 Ozone SRR
provides States with the option to use an alternative baseline year for
RFP, but that provision of the 2008 Ozone SRR was vacated by the D.C.
Circuit in the South Coast II decision.
2. Summary of the State's Submission
The 2022 Coachella Valley RFP Plan includes an RFP demonstration
developed using updated emissions estimates for the baseline,
milestone, and attainment years, and updated emissions estimates
relying on a 2011 baseline year.\26\ The RFP demonstration is
reproduced in Table 4 of this document.
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\26\ See the RFP demonstration in the 2022 Coachella Valley RFP
Plan, Chapter 6, starting on page 6-1.
Table 4--Reasonable Further Progress Demonstration in the 2022 Coachella Valley RFP Plan
----------------------------------------------------------------------------------------------------------------
VOC (tpd)
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2011 2017 2020 2023 2026 2029 2031
----------------------------------------------------------------------------------------------------------------
Baseline VOC.............................. 16.27 13.48 13.16 12.75 12.72 12.75 12.81
Transportation Conformity Rounding Margin. 0 0 0 0.05 0.09 0.04 0.05
Baseline VOC + Rounding Margin............ 16.27 13.48 13.16 12.80 12.81 12.79 12.86
Required % Change Since 2011 Target VOC ........ 18% 27% 36% 45% 54% 60%
Level....................................
Required tpd Reductions Since 2011........ ........ 2.93 4.39 5.85 7.32 8.78 9.76
Target VOC Level.......................... ........ 13.34 11.88 10.42 8.95 7.49 6.51
Apparent Shortfall (-)/Surplus(+) in VOC.. ........ -0.14 -1.28 -2.38 -3.86 -5.31 -6.35
Apparent Shortfall (-)/Surplus(+) in VOC, ........ -1% -8% -15% -24% -33% -39%
%........................................
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[[Page 68065]]
NOX (tpd)
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2011 2017 2020 2023 2026 2029 2031
----------------------------------------------------------------------------------------------------------------
Baseline NOX.............................. 27.49 19.45 17.42 14.64 14.19 14.00 13.95
Transportation Conformity Rounding Margin. 0 0 0 0.01 0.01 0.09 0
Baseline NOX + Rounding Margin............ 27.49 19.45 17.42 14.65 14.20 14.09 13.95
Change in NOX tpd Since 2011.............. ........ 8.04 10.07 12.84 13.30 13.41 13.54
Change in NOX Since 2011, %............... ........ 29% 37% 47% 48% 49% 49%
NOX Reductions Since 2011 Used for VOC ........ 1% 8% 15% 24% 33% 39%
Substitution in This Milestone Year, %...
Apparent Shortfall (-)/Surplus (+) in NOX, ........ 28% 29% 32% 25% 16% 10%
%........................................
RFP Shortfall (-), If Any................. ........ 0% 0% 0% 0% 0% 0%
RFP Met?.................................. ........ YES YES YES YES YES YES
----------------------------------------------------------------------------------------------------------------
Source: 2022 Coachella Valley RFP Plan, Table 6-1.
The RFP demonstration calculates future year VOC targets from the
2011 baseline, consistent with CAA section 182(c)(2)(B)(i), which
requires reductions of ``at least 3 percent of baseline emissions each
year.'' The 2022 Coachella Valley RFP Plan substitutes NO<INF>X</INF>
reductions for VOC reductions \27\ beginning in milestone year 2017,
pursuant to CAA section 182(c)(2)(C). CARB concludes that the RFP
demonstration in the 2022 Coachella Valley RFP Plan meets the
applicable requirements for each milestone year as well as the
attainment year.
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\27\ NO<INF>X</INF> substitution is permitted under EPA
regulations. See 40 CFR 51.1110(a)(2)(i)(C) and 40 CFR
51.1110(a)(2)(ii)(B); and 80 FR 12264, 12271 (Mar. 6, 2015).
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3. The EPA's Review of the State's Submission
As discussed in section IV.A of this document, we are proposing to
find that the baseline year and RFP milestone year emissions
inventories are acceptable for use in the RFP demonstration. We have
reviewed the calculations in Table 6-1 of the 2022 Coachella Valley RFP
Plan and presented in Table 4 of this document and propose to find that
the State has used an appropriate calculation method to demonstrate
RFP. For these reasons, we are proposing to determine that the State
has demonstrated RFP in each milestone year and the attainment year,
consistent with applicable CAA requirements and EPA guidance. We
therefore propose to approve the RFP demonstrations under CAA sections
172(c)(2), 182(b)(1) and 182(c)(2)(B) and 40 CFR 51.1110(a)(2)(ii).
C. Motor Vehicle Emissions Budgets for Transportation Conformity
1. Statutory and Regulatory Requirements
CAA section 176(c) requires Federal actions in nonattainment and
maintenance areas to conform to the SIP's goals of eliminating or
reducing the severity and number of violations of the NAAQS and
achieving timely attainment of the standards. Conformity to the SIP's
goals means that such actions will not: (1) cause or contribute to
violations of a NAAQS; (2) worsen the severity of an existing
violation; or (3) delay timely attainment of any NAAQS or any interim
milestone.\28\
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\28\ CAA section 176(c)(1)(B)(i).
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Actions involving Federal Highway Administration (FHWA) or Federal
Transit Administration (FTA) funding or approval are subject to the
EPA's transportation conformity rule, codified at 40 CFR part 93,
subpart A. Under this rule, MPOs in nonattainment and maintenance areas
coordinate with State and local air quality and transportation
agencies, the EPA, the FHWA, and the FTA to demonstrate that an area's
regional transportation plans and transportation improvement programs
conform to the applicable SIP. This demonstration is typically done by
showing that estimated emissions from existing and planned highway and
transit systems are less than or equal to the motor vehicle emissions
budgets (``budgets'') contained in all control strategy SIPs. Budgets
are generally established for specific years and specific pollutants or
precursors. Ozone plans should identify budgets for on-road emissions
of ozone precursors (i.e., NO<INF>X</INF> and VOC) in the area for each
RFP milestone year (and the attainment year, if the plan demonstrates
attainment).\29\
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\29\ See 40 CFR 93.102(b)(2)(i).
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For budgets to be approvable, they must meet, at a minimum, the
EPA's adequacy criteria at 40 CFR 93.118(e)(4). To meet these
requirements, the budgets must be consistent with the attainment and
RFP requirements and reflect all of the motor vehicle control measures
contained in the attainment and RFP demonstrations.\30\ The Agencies'
process for determining adequacy of a budget consists of three basic
steps: (1) providing public notification of a SIP submission; (2)
providing the public the opportunity to comment on the budget during a
public comment period; and (3) making a finding of adequacy.\31\
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\30\ See 40 CFR 93.118(e)(4)(iii), (iv) and (v).
\31\ See 40 CFR 93.118(f)(2).
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2. Summary of the State's Submission
The 2022 Coachella Valley RFP Plan includes budgets for the 2023,
2026, and 2029 RFP milestone years, and the 2031 attainment year. In
March 2023, the EPA found the budgets adequate for transportation
conformity purposes.\32\
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\32\ See 88 FR 18314 (Mar. 28, 2023).
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The budgets in the 2022 Coachella Valley RFP Plan were calculated
using updated vehicle miles traveled (VMT) estimates from SCAG's
``Connect SoCal 2020 Regional Transportation Plan/Sustainable
Communities Strategy'' (``2020 RTP/SCS'') and EMFAC2017, CARB's latest
approved version of the EMFAC model for estimating emissions from on-
road vehicles operating in California at the time of SIP development,
and reflect average summer weekday emissions consistent with the RFP
milestone years and the 2031 attainment year for the 2008 ozone NAAQS.
The conformity budgets for NO<INF>X</INF> and VOC for each county in
the
[[Page 68066]]
nonattainment area are provided in Table 5 of this document.
Table 5--Budgets in the Coachella Valley RFP Plan
[Summer average tons per day]
----------------------------------------------------------------------------------------------------------------
Year VOC (tpd) NOX (tpd)
----------------------------------------------------------------------------------------------------------------
2023.......................................................... 2.7 6.0
2026.......................................................... 2.5 5.8
2029.......................................................... 2.3 5.8
2031.......................................................... 2.2 5.7
----------------------------------------------------------------------------------------------------------------
Source: 2022 Coachella Valley RFP Plan, Table 7-1.
3. The EPA's Review of the State's Submission
The EPA previously found the budgets in the 2022 Coachella Valley
RFP Plan to be adequate based on our adequacy criteria in 40 CFR
93.118(e)(4) and (5).\33\ On December 21, 2022, the Agency announced
the availability of the 2022 Coachella Valley RFP Plan and related
budgets on the EPA's transportation conformity website, requesting
comments by January 20, 2023.\34\ The Agency received no comments from
the public. By letter dated March 17, 2023, the EPA determined that the
2023, 2026, 2029, and 2031 budgets were adequate for transportation
conformity purposes.\35\ On March 28, 2023, we published a notice of
adequacy in the Federal Register.\36\ Since the effective date of our
adequacy finding, April 12, 2023, the U.S. Department of Transportation
and the applicable metropolitan transportation organization, SCAG, have
been using the adequate budgets for transportation conformity
determinations for the area. The Agency is not required under its
transportation conformity rule to find motor vehicle emissions budgets
adequate prior to proposing approval of them, but in this instance, we
completed the adequacy review of these motor vehicle emissions budgets
prior to our proposed action on the 2022 Coachella Valley RFP Plan.
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\33\ 88 FR 18314.
\34\ The EPA maintains a website that lists motor vehicle
emissions budgets the EPA is reviewing or has reviewed for adequacy.
See the EPA adequacy review web page: <a href="https://www.epa.gov/state-and-local-transportation/adequacy-review-state-implementation-plan-sip-submissions-conformity">https://www.epa.gov/state-and-local-transportation/adequacy-review-state-implementation-plan-sip-submissions-conformity</a>.
\35\ Letter dated Mar. 17, 2023, from Elizabeth J. Adams, Air
and Radiation Division Director, EPA Region 9, to Steven S. Cliff,
Executive Officer, CARB.
\36\ 88 FR 18314.
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The EPA is proposing to approve the 2023, 2026, 2029, and 2031
budgets in the 2022 Coachella Valley RFP Plan for transportation
conformity purposes because we find that the budgets are consistent
with the emission control measures in the SIP and RFP demonstration for
the 2008 ozone NAAQS,\37\ and that the RFP demonstration and budgets
rely on the same base year and projected emissions inventories
calculated using EMFAC2017 and vehicle activity data from SCAG's 2020
RTP/SCS.
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\37\ Because the EPA has not approved an Extreme area attainment
demonstration for the Coachella Valley for the 2008 ozone NAAQS, the
EPA is not assessing the consistency of the budgets with respect to
an attainment demonstration as part of this action. An attainment
demonstration was not included in the 2022 Coachella Valley RFP
Plan.
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The 2022 Coachella Valley RFP Plan budgets as shown in Table 5 of
this document are consistent with the RFP demonstration, are clearly
and precisely quantified, and meet all other applicable statutory and
regulatory requirements, including the adequacy criteria in 40 CFR
93.118(e)(4) and (5). For these reasons, the EPA proposes to approve
the budgets in Table 5 of this document. If we finalize approval of the
budgets in the 2022 Coachella Valley RFP Plan as proposed, they will
replace the budgets previously found adequate for use in conformity
determinations by transportation agencies in the Coachella Valley.
V. Proposed Action
For the reasons discussed in this proposed rulemaking, under CAA
section 110(k)(3), the EPA is proposing to approve as a revision to the
California SIP the Extreme area RFP demonstration and associated
emissions inventory and budgets for the Coachella Valley with respect
to the 2008 ozone NAAQS. This proposed rulemaking does not address any
other Extreme area requirements for the Coachella Valley with respect
to the 2008 ozone NAAQS. CARB submitted other 2008 ozone NAAQS Extreme
area elements for the Coachella Valley on October 30, 2024,\38\ and we
plan to act on this submittal at a later date.
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\38\ Letter dated Oct. 29, 2024, from Steven S. Cliff, Executive
Officer, CARB, to Martha Guzman, Regional Administrator, EPA Region
9.
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The EPA is soliciting public comments on this proposed action,
including our rationale and any other pertinent matters related to the
issues discussed herein. We will accept comments from the public on
this proposal for the next 30 days and will consider comments before
taking final action.
VI. Statutory and Executive Order Reviews
Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the Act and applicable
Federal regulations (see 42 U.S.C. 7410(k); 40 CFR 52.02(a)). Thus, in
reviewing SIP submissions, the EPA's role is to approve State choices,
provided that they meet the criteria of the CAA. Accordingly, this
action merely proposes to approve a State plan as meeting Federal
requirements and does not impose additional requirements beyond those
imposed by State law. For that reason, this proposed action:
<bullet> Is not a significant regulatory action subject to review
by the Office of Management and Budget under Executive Order 12866 (58
FR 51735, Oct. 4, 1993);
<bullet> Is not an Executive Order 14192 (90 FR 9065, Feb. 6, 2025)
regulatory action because this action is not significant under
Executive Order 12866;
<bullet> Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
<bullet> Is certified as not having a significant economic impact
on a substantial number of small entities under the Regulatory
Flexibility Act (5 U.S.C. 601 et seq.);
<bullet> Does not contain any unfunded mandate or significantly or
uniquely affect small governments, as described in the Unfunded
Mandates Reform Act of 1995 (Pub. L. 104-4);
<bullet> Does not have federalism implications as specified in
Executive
[[Page 68067]]
Order 13132 (64 FR 43255, Aug. 10, 1999);
<bullet> Is not subject to Executive Order 13045 (62 FR 19885, Apr.
23, 1997) because it proposes to approve a State program;
<bullet> Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001); and
<bullet> Is not subject to requirements of section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272
note) because application of those requirements would be inconsistent
with the CAA.
In addition, the SIP is not approved to apply on any Indian
reservation land or in any other area where the EPA or an Indian Tribe
has demonstrated that a Tribe has jurisdiction. In those areas of
Indian country, the proposed rule does not have Tribal implications and
will not impose substantial direct costs on Tribal governments or
preempt Tribal law as specified by Executive Order 13175 (65 FR 67249,
Nov. 9, 2000).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Nitrogen oxides, Ozone,
Reporting and recordkeeping requirements, Volatile organic compounds.
Authority: 42 U.S.C. 7401 et seq.
Dated: October 19, 2026.
Michael Martucci,
Acting Regional Administrator, EPA Region IX.
[FR Doc. 2026-22055 Filed 10-28-26; 8:45 am]
BILLING CODE 6560-50-P
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This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.