SUPPLEMENTARY INFORMATION:

Throughout this proposed rule, the use ( printed 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_X —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.

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.

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]

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.

On March 8, 2023, the EPA granted a request from California to reclassify the ( printed 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.

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”).

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.

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.

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.

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.

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 ( printed 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]

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_X 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]

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_X 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_X 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.

Table 1 of this document provides a summary of the Coachella Valley 2011 base year VOC and NO_X emissions inventories, grouped by major source category.

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_X emissions inventories for RFP baseline and milestone years, grouped by major source category.

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.

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_X for a typical ozone season weekday and that CARB has provided adequate documentation explaining how the ( printed 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_X reductions for VOC reductions to meet the CAA section 172(c)(2) and 182(c)(2)(B) RFP requirements.^[23]

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]

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.

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_X 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.

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]

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_X and VOC) in the area for each RFP milestone year (and the attainment year, if the plan demonstrates attainment).^[29]

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]

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]

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_X and VOC for each county in the ( printed page 68066) nonattainment area are provided in Table 5 of this document.

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.

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.

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.

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 ( see42 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:

• Is not a significant regulatory action subject to review by the Office of Management and Budget underExecutive Order 12866 (58 FR 51735, Oct. 4, 1993);
• Is not anExecutive Order 14192 (90 FR 9065, Feb. 6, 2025) regulatory action because this action is not significant under Executive Order 12866;
• Does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
• Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.);
• Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);
• Does not have federalism implications as specified in Executive ( printed page 68067) Order 13132 (64 FR 43255, Aug. 10, 1999);
• Is not subject toExecutive Order 13045 (62 FR 19885, Apr. 23, 1997) because it proposes to approve a State program;
• Is not a significant regulatory action subject toExecutive Order 13211 (66 FR 28355, May 22, 2001); and
• Is not subject to requirements of section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requirements would be inconsistent with the 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).

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

91 FR 68059