SUPPLEMENTARY INFORMATION:

Throughout this document, “we,” “us,” and “our” refer to the EPA.

Table of Contents

I. Background

A. PM_2.5 NAAQS

B. San Joaquin Valley PM_2.5 Designations, Classifications, and SIP Revisions

II. Completeness Review of the 2024 San Joaquin Valley PM_2.5 Plan

III. Clean Air Act Requirements for an Extension of a Serious Area Attainment Date

IV. Review of the State's Request

A. Demonstration That Attainment by Serious Area Attainment Date Is Impracticable

B. Compliance With State Implementation Plan Requirements and Commitments

C. Demonstration That the Implementation Plan Includes the Most Stringent Measures

D. Demonstration of Attainment by the Most Expeditious Alternative Date Practicable

E. Application for an Attainment Date Extension

F. Other Factors That the EPA May Consider

V. Summary of Proposed Action and Request for Public Comment

VI. Statutory and Executive Order Reviews

I. Background

A. PM_2.5 NAAQS

Under section 109 of the Clean Air Act (CAA or “Act”), 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 they should be revised or whether new NAAQS should be established. On January 15, 2013, the EPA strengthened the primary annual NAAQS for PM_2.5 by lowering the level from 15.0 µg/m^[3] to 12.0 µg/m^[3] (“2012 annual PM_2.5 NAAQS”).^[1]

The EPA established the PM_2.5 NAAQS after considering substantial evidence from numerous health studies demonstrating that serious health effects are associated with exposures to PM_2.5 concentrations above these levels. Epidemiological studies have shown statistically significant correlations between elevated PM_2.5 levels and premature mortality. Other important health effects associated with PM_2.5 exposure include aggravation of respiratory and cardiovascular disease (as indicated by increased hospital admissions, emergency room visits, absences from school or work, and restricted activity dates), changes in lung function, and increased respiratory symptoms. Individuals particularly sensitive to PM_2.5 exposure include older adults, people with heart and lung disease, and children.^[2]

Sources can emit PM_2.5 directly into the atmosphere as a solid or liquid particle (primary PM_2.5 or direct PM_2.5), or PM_2.5 can form in the atmosphere (secondary PM_2.5) as a result of various chemical reactions from precursor emissions of nitrogen oxides (NO_X), sulfur oxides (SO_X ), volatile organic compounds (VOC), and ammonia.^[3]

( printed page 35438)

B. San Joaquin Valley PM_2.5 Designations, Classifications, and SIP Revisions

The San Joaquin Valley PM_2.5 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.^[4] The area is home to four million people and is the nation's leading agricultural region. Stretching over 250 miles from north to south and averaging 80 miles wide, it is partially enclosed by the Coast Mountain range to the west, the Tehachapi Mountains to the south, and the Sierra Nevada range to the east. 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 these plans. Authority for regulating sources in the San Joaquin Valley nonattainment area is split between the District, which has responsibility for regulating stationary and most area sources, and CARB, which has responsibility for regulating most mobile sources and some categories of consumer products.

Following promulgation of a new or revised NAAQS, the EPA is required under CAA section 107(d) to designate areas throughout the nation as attaining or not attaining the NAAQS. On January 15, 2015, the EPA designated and classified the San Joaquin Valley as “Moderate” nonattainment for the 2012 PM_2.5 NAAQS.^[5]

On May 10, 2019, CARB made two SIP submissions to address the CAA requirements associated with the 2012 annual PM_2.5 NAAQS in the San Joaquin Valley: the “2016 Moderate Area Plan for the 2012 PM_2.5 Standard” (“2016 PM_2.5 Plan”) and the “2018 Plan for the 1997, 2006, and 2012 PM_2.5 Standards” (“2018 PM_2.5 Plan”).^[6] On December 13, 2019, CARB submitted additional documents supporting the 2016 and 2018 PM_2.5 Plans that were inadvertently omitted from the May 10, 2019 SIP submission.^[7] The 2016 PM_2.5 Plan included a demonstration, to address the requirements of CAA section 189(a)(1)(B), that attainment of the 2012 annual PM_2.5 NAAQS by the December 31, 2021 Moderate area attainment date in the San Joaquin Valley was impracticable.^[8] The 2018 PM_2.5 Plan addressed the Serious area attainment plan requirements for the 2012 PM_2.5 NAAQS in anticipation of the reclassification of San Joaquin Valley from Moderate to Serious nonattainment for that PM_2.5 NAAQS. Lastly, in 2023, CARB submitted two additional SIP revisions addressing contingency measure requirements for the San Joaquin Valley for numerous standards including the 2012 annual PM_2.5 NAAQS.^[9] These SIP revisions are referred to herein as the “2023 Contingency Measure SIP Submittals.”

Effective December 27, 2021, the EPA approved all of the 2012 annual PM_2.5 Moderate area requirements included in the 2016 PM_2.5 Plan except for contingency measures and, pursuant to CAA section 188(b)(1), reclassified the area as a Serious nonattainment area for the 2012 annual PM_2.5 NAAQS.^[10] The EPA took final action to approve the 2023 Contingency Measure SIP Submittals as satisfying the Moderate contingency measure requirement for the San Joaquin Valley 2012 annual PM_2.5 nonattainment area on October 4, 2024.^[11]

Upon reclassification as a Serious PM_2.5 nonattainment area, the San Joaquin Valley area became subject to a new statutory attainment date of as expeditiously as practicable but no later than the end of the tenth calendar year following designation ( i.e., December 31, 2025) and a requirement to submit a Serious area plan satisfying the requirements of CAA title I, part D, including the requirements of subpart 4, for the 2012 annual PM_2.5 NAAQS.^[12] As explained in the EPA's final reclassification action, the Serious area plan for the San Joaquin Valley must include, among other things, provisions to assure that, under CAA section 189(b)(1)(B), the best available control measures (BACM) for the control of direct PM_2.5 and PM_2.5 precursors shall be implemented no later than four years after the area is reclassified and a demonstration (including air quality modeling) that the plan provides for attainment as expeditiously as practicable and no later than the applicable attainment date. The EPA also noted that California may choose to submit a request for an extension of the December 31, 2025 Serious area attainment date pursuant to CAA section 188(e).^[13] Our final action on the 2016 PM_2.5 Plan's Moderate area requirements and reclassification of the nonattainment area to Serious noted that the submitted 2018 PM_2.5 Plan included Serious area planning elements for the 2012 annual PM_2.5 NAAQS and stated that the EPA would evaluate and act on those elements through subsequent rulemakings as appropriate.^[14]

The EPA initially proposed to approve the 2012 annual PM_2.5 Serious area planning requirements in the 2018 PM_2.5 Plan except for contingency measures.^[15] However, based on comments received on the proposed approval and a Ninth Circuit Court of Appeals decision on a San Joaquin Valley PM_2.5 rulemaking for the 2006 24-hour PM_2.5 NAAQS, the EPA reconsidered and proposed to disapprove the District's 2012 PM_2.5 Serious area plan for certain elements.^[16] Following the EPA's reproposal to disapprove the Serious area elements in the 2018 PM_2.5 Plan, CARB withdrew the portions of the 2018 PM_2.5 Plan addressing the 2012 annual PM_2.5 Serious area requirements.^[17]

On November 21, 2023, CARB submitted the “Initial SIP Requirements for the 2012 Annual PM_2.5 Standard,” which addressed Serious area requirements for the San Joaquin Valley 2012 annual PM_2.5 nonattainment area, including emissions inventory and BACM requirements.^[18] On August 22, ( printed page 35439) 2024, CARB submitted the “2024 Plan for the 2012 Annual PM_2.5 Standard” (“2024 San Joaquin Valley PM_2.5 Plan” or “Plan”), adopted by SJVUAPCD on June 20, 2024, and by CARB on July 25, 2024.^[19] The 2024 San Joaquin Valley PM_2.5 Plan addresses the Serious area nonattainment plan requirements for the 2012 annual PM_2.5 NAAQS in the San Joaquin Valley nonattainment area and includes a request under CAA section 188(e) for an extension of the Serious area attainment date for the area for these NAAQS from December 31, 2025, to December 31, 2030.

II. Completeness Review of the 2024 San Joaquin Valley PM _2.5 Plan

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. CARB and the District have satisfied applicable statutory and regulatory requirements for reasonable public notice and hearing prior to adoption and submittal of the 2024 San Joaquin Valley PM_2.5 Plan. The District provided a public comment period for the Plan and held a public hearing on June 20, 2024, and CARB provided a public comment period and held a public hearing prior to the adoption of the Plan on July 25, 2024. The Plan includes notices of CARB's and the District's public hearings as evidence that the hearings were properly noticed.^[20] Thus, our review indicates that the 2024 San Joaquin Valley PM_2.5 Plan meets the procedural requirements of CAA sections 110(a) and 110(l).

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. The 2024 San Joaquin Valley PM_2.5 Plan became complete by operation of law on February 22, 2025.

III. Clean Air Act Requirements for an Extension of a Serious Area Attainment Date

Under section 188(e) of the Act, a State may apply to the EPA for a single extension of the Serious area attainment date by up to five years, which the EPA may grant if the State satisfies certain conditions. Before the EPA may extend the attainment date for a Serious area under CAA section 188(e), the State must:

(1) Demonstrate that attainment by the Serious area attainment date is impracticable;

(2) Demonstrate that it has complied with all requirements and commitments pertaining to the area in the implementation plan;

(3) Demonstrate to the satisfaction of the Administrator that the plan for the area includes the “most stringent measures” (MSM) that are included in the implementation plan of any state or are achieved in practice in any state and can feasibly be implemented in the area;

(4) Submit a modeled attainment demonstration showing attainment of the NAAQS in the area by the most expeditious alternative date practicable; and

(5) Apply for an extension of the attainment date beyond the Serious area attainment date.^[21]

A State must seek an extension of the Serious area attainment date at the same time it submits the Serious area attainment plan if the State cannot demonstrate attainment by the otherwise applicable statutory attainment date.^[22]

The EPA established regulatory requirements and provided further interpretive guidance on the statutory SIP requirements that apply to areas designated nonattainment for the PM_2.5 standards in an August 24, 2016 final rule entitled “Fine Particulate Matter National Ambient Air Quality Standards: State Implementation Plan Requirements” (“PM_2.5 SIP Requirements Rule”). Under the EPA's regulations at 40 CFR 51.1005(b)(2), a State seeking an extension of the Serious area attainment date under CAA section 188(e) must also submit a Serious area attainment plan that meets the following requirements:

(1) Base year and attainment projected emissions inventory requirements in 40 CFR 51.1008(b);

(2) The MSM requirement in 40 CFR 51.1005(b)(1)(iii) and 51.1010(b), and best available control measures not previously submitted;

(3) Attainment demonstration and modeling requirements in 40 CFR 51.1011 and 40 CFR 51.1005(b)(1)(i);

(4) Reasonable further progress (RFP) requirements in 40 CFR 51.1012;

(5) Quantitative milestone requirements in 40 CFR 51.1013;

(6) Contingency measure requirements in 40 CFR 51.1014; and

(7) Nonattainment new source review plan requirements pursuant to 40 CFR 51.165.^[23]

In addition to establishing specific preconditions for an extension of the Serious area attainment date, CAA section 188(e) provides that the EPA may consider a number of factors in determining whether to grant an extension and the appropriate length of time for any such extension. These factors are: (1) the nature and extent of nonattainment in the area, (2) the types and numbers of sources or other emitting activities in the area (including the influence of uncontrollable natural sources and trans-boundary emissions from foreign countries), (3) the population exposed to concentrations in excess of the standard in the area, (4) the presence and concentrations of potentially toxic substances in the mix of particulate emissions in the area, and (5) the technological and economic feasibility of various control measures.^[24] Notably, neither the statutory requirements nor the discretionary factors identified in CAA section 188(e) include the specific ambient air quality conditions in CAA section 188(d)(2) that must be met for an area to qualify for an extension of a Moderate area attainment date.

The EPA is evaluating the State's request for an extension of the Serious area attainment date in accordance with these statutory criteria and regulatory requirements, as further described below.

1. Demonstrate That Attainment by the Serious Area Attainment Date Is Impracticable

Section 188(e) of the Act authorizes the EPA to grant a State request for an extension of the Serious area attainment date if, among other things, attainment by the date established under CAA section 188(c) would be impracticable. In order to demonstrate impracticability, ( printed page 35440) EPA guidance has stated that the plan must show that the implementation of BACM and best available control technology (BACT) (and additional feasible measures) on relevant source categories will not bring the area into attainment by the statutory Serious area attainment date.^[25] For the San Joaquin Valley, the Serious area attainment date for the 2012 annual PM_2.5 NAAQS under CAA section 188(c)(2) is December 31, 2025.^[26]

The EPA has defined BACM in the PM_2.5 SIP Requirements Rule to mean “any technologically and economically feasible control measure that can be implemented in whole or in part within 4 years after the date of reclassification of a Moderate PM_2.5 nonattainment area to Serious and that generally can achieve greater permanent and enforceable emissions reductions in direct PM_2.5 emissions and/or emissions of PM_2.5 plan precursors from sources in the area than can be achieved through the implementation of RACM on the same source(s). BACM includes BACT.” ^[27]

Consistent with longstanding EPA guidance,^[28] the preamble to the PM_2.5 SIP Requirements Rule discusses the following steps for determining BACM and BACT:

(1) Develop a comprehensive emissions inventory of the sources of PM_2.5 and PM_2.5 precursors;

(2) Identify potential control measures;

(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.^[29]

The EPA allows consideration of factors such as physical plant layout, energy requirements, needed infrastructure, and workforce type and habits when considering technological feasibility. For purposes of evaluating economic feasibility, the EPA allows consideration of 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.^[30]

2. Comply With All Requirements and Commitments in the Applicable Implementation Plan

A second precondition for an extension of the Serious area attainment date under CAA section 188(e) is a showing that the State has complied with all requirements and commitments pertaining to that area in the implementation plan. We interpret this criterion to mean that the state has implemented the control measures and commitments in the SIP revisions it has submitted to address the applicable requirements in CAA sections 172 and 189 for that particular PM_2.5 nonattainment area, in this case the San Joaquin Valley nonattainment area for the 2012 annual PM_2.5 NAAQS.^[31] For a Serious area attainment date extension request being submitted simultaneously with the initial Serious area attainment plan for the area, the EPA interprets CAA section 188(e) not to require the area to have a fully approved Moderate area attainment plan and to allow for extension of the attainment date if the area has complied with all Moderate area requirements and commitments pertaining to that area in the State's submitted Moderate area implementation plan.^[32] This interpretation is based on the plain language of CAA section 188(e), which requires the State to comply with all requirements and commitments pertaining to the area in the implementation plan.^[33]

3. Demonstrate the Inclusion of the Most Stringent Measures

A third precondition for an extension of the Serious area attainment under CAA section 188(e) is for the State to demonstrate to the satisfaction of the Administrator that the plan for the area includes the MSM that are included in the implementation plan of any state, or are achieved in practice in any state, and can feasibly be implemented in the area. The EPA has defined the term MSM as “any permanent and enforceable control measure that achieves the most stringent emissions reductions in direct PM_2.5 emissions and/or emissions of PM_2.5 plan precursors from among those control measures which are either included in the SIP for any other NAAQS, or have been achieved in practice in any state, and that can feasibly be implemented in the relevant PM_2.5 NAAQS nonattainment area.” ^[34] The EPA has interpreted the Act to require implementation of MSM as expeditiously as practicable and no later than one year before the extended Serious area attainment date identified by the State in its extension request.^[35]

An MSM demonstration must satisfy the requirements of the PM_2.5 SIP Requirements Rule as described in the preamble to the rule, as follows: ^[36]

(1) Update the emissions inventory to identify all sources of direct PM_2.5 and PM_2.5 precursor emissions in the nonattainment area;

(2) Identify all potential MSM to reduce emissions from sources of direct PM_2.5 and PM_2.5 plan precursors that are approved into any state implementation plan or used in practice in any state;

(3) Compare the potential MSM for each relevant source category to the measures, if any, already adopted for that source category in the nonattainment area to determine whether such potential MSM would further reduce emissions and, where the State chooses to reject a measure from further consideration, demonstrate that it is not technologically or economically feasible to implement the measure in whole or in part within five years after ( printed page 35441) the applicable attainment date for the area; and

(4) Adopt and implement all potential MSM identified through this process that collectively will achieve attainment as expeditiously as practicable and no later than five years after the applicable attainment date, except those measures for which the state has provided reasoned justification for rejection, based on technological or economic feasibility.

Notably, the “to the satisfaction of the Administrator” qualifier on the MSM requirement is an explicit grant by Congress to the EPA of discretion to determine whether a plan includes MSM.

4. Submit a Demonstration of Attainment by the Most Expeditious Alternative Date Practicable

Section 189(b)(1)(A) of the Act requires that the State submit a demonstration of attainment, including air quality modeling, by the most expeditious date practicable after the statutory Serious area attainment date.^[37] Section 188(e) of the CAA states that the threshold requirement is submission of such a demonstration.^[38] Accordingly, the EPA must evaluate whether the submission containing the extension request also includes such a demonstration.

5. Apply for an Attainment Date Extension

Finally, the State must apply in writing to the EPA for an extension of a Serious area attainment date, and this request must accompany the submission of the modeled attainment demonstration showing attainment by the most expeditious alternative date practicable. Additionally, the State must provide the public reasonable notice and opportunity for a public hearing on the attainment date extension request before submitting it to the EPA in accordance with the requirements for SIP revisions in CAA section 110.

IV. Review of the State's Request

In this section of the preamble, we present our evaluation of the State's request to extend the Serious area attainment date from December 31, 2025, to December 31, 2030, under CAA section 188(e).

A. Demonstration That Attainment by Serious Area Attainment Date Is Impracticable

The 2024 San Joaquin Valley PM_2.5 Plan includes a demonstration, based on air quality modeling, that even with the implementation of BACM and BACT for all appropriate sources, attainment by December 31, 2025, is not practicable. The impracticability demonstration is described in Chapter 5.2.1 of the Plan and references the modeling information provided in Appendix J of the Plan. The BACM/BACT demonstration is included in Appendices C (for District measures) and D (for State measures) of the Plan. Because of the substantial overlap in the source categories and controls evaluated for BACM and those evaluated for MSM, the BACM demonstration is discussed alongside our evaluation of the Plan's MSM demonstration in section IV.C of this document.

Table 26 in Appendix J of the plan presents modeled 2030 annual PM_2.5 design values. The results of the District's modeling are summarized in table 1 of this document.

The results of the District's modeling indicate that, even with the implementation of the control strategy in the 2024 San Joaquin Valley PM_2.5 Plan according to the implementation schedules in Chapter 4 of the Plan, the San Joaquin Valley area will narrowly attain the 2012 annual PM_2.5 NAAQS by 2030. The District's demonstration of attainment in the San Joaquin Valley by 2030 relies in part on measures that will be implemented between the end of 2025 and 2030; these measures account for over 4.3 tons per day of NO_X emissions reductions and 0.2 tons per day of direct PM_2.5 emissions reductions between the end of 2025 and 2030.^[39] Accounting for the timing of these emissions reductions and the narrow margin by which the nonattainment area is projected to attain in 2030, the ( printed page 35442) District's modeling supports the conclusion that attainment of the 2012 annual PM_2.5 NAAQS by the current December 31, 2025 attainment date is impracticable.

In addition to the information in the San Joaquin Valley PM_2.5 Plan, we have reviewed recent PM_2.5 monitoring data from the San Joaquin Valley. These data show that annual average PM_2.5 levels in the San Joaquin Valley continue to be above the 12.0 µg/m³ level of the 2012 annual PM_2.5 NAAQS in 2023 or 2024 at seven monitoring sites. Furthermore, based on monitored ambient PM_2.5 air quality data from 2023 and 2024, we determined that the maximum 2025 annual average concentration that would result in an attaining 2025 design value ( i.e., a 3-year average PM_2.5 concentration of 12.04 µg/m³ ) for each monitoring site with annual averages in 2023 and 2024 above the 2012 PM_2.5 NAAQS, and we compared these concentrations to the lowest recorded annual average PM_2.5 concentrations at the site. This comparison is shown in table 2 below.

The EPA found that three monitoring sites in the San Joaquin Valley Air Basin would need to have 2025 annual mean concentrations 19 percent or more below their corresponding historical lows in order to attain by the end of 2025. The most extreme example is the Bakersfield-Airport (Planz) monitoring site, which would require concentrations approximately 35 percent below the lowest previously recorded concentration at this site. Considering the District's assertion that the control strategy in the 2024 San Joaquin Valley PM_2.5 Plan includes all BACM and MSM, there is no indication that the control strategy could achieve such steep reductions so quickly.

In sum, the District's air quality modeling projections for 2030, which account for the implementation of controls according to the implementation schedules submitted in the Plan, and monitored air quality data from 2023 and 2024 indicate that it is impracticable for the San Joaquin Valley nonattainment area to show attainment of the 2012 annual PM_2.5 NAAQS by December 31, 2025. Thus, our review of the impracticability demonstration and related information in the Plan as well as monitoring data from the San Joaquin Valley nonattainment area indicate that the area could not practicably attain the 2012 annual PM_2.5 NAAQS by the applicable attainment date of December 31, 2025.

B. Compliance With State Implementation Plan Requirements and Commitments

We interpret this criterion to mean that the State has implemented the control measures and commitments in the plan revisions it has submitted to address the applicable requirements in CAA sections 172 and 189 for the relevant PM_2.5 NAAQS for the nonattainment area.^[40] For the San Joaquin Valley for the 2012 annual PM_2.5 NAAQS, the State has submitted, and the EPA has approved into the California SIP, the control measure requirements and commitments in the 2016 PM_2.5 Plan that pertained to the Moderate area planning requirements for the 2012 annual PM_2.5 NAAQS. In the remainder of this section, we describe the State's and District's implementation of those control measures.

As discussed in section I of this document, CARB submitted the 2016 PM_2.5 Plan to the EPA on May 10, 2019. On November 26, 2021, the EPA approved all but the contingency measure element of the submitted SIP revision as meeting all applicable Moderate area requirements for the 2012 annual PM_2.5 NAAQS.^[41] The EPA approved the 2012 annual PM_2.5 Moderate area contingency measure element for the San Joaquin Valley on October 4, 2024.^[42]

The 2024 San Joaquin Valley PM_2.5 plan addresses compliance with the applicable 2016 PM_2.5 Plan Moderate area planning requirements and commitments for the 2012 annual PM_2.5 NAAQS in Chapter 5.2.2 of the Plan. While the 2016 PM_2.5 Plan includes an evaluation of potential control measures for adoption as RACM, RACT, or additional reasonable measures, the District did not identify any feasible control measures beyond those that had already been adopted and implemented, and thus the District did not include any commitments for additional measures for purposes of meeting the Moderate area planning requirements. Given that the EPA has fully approved the Moderate area planning requirements for the area and that there are no outstanding commitments or other obligations relating to those requirements, our review indicates that the State has complied with all requirements and commitments in the plan revisions it has submitted to address the applicable requirements in CAA sections 172 and 189 for the 2012 annual PM_2.5 NAAQS for the San Joaquin Valley nonattainment area. ( printed page 35443)

C. Demonstration That the Implementation Plan Includes the Most Stringent Measures

Before the EPA may extend the attainment date for a Serious nonattainment area under CAA section 188(e), the State must, among other things, demonstrate to the satisfaction of the Administrator that the plan for the area includes the most stringent measures (MSM) that are included in the implementation plan of any state, or are achieved in practice in any state, and can feasibly be implemented in the area. The State must implement MSM as expeditiously as practicable and no later than the beginning of the year containing the attainment date identified by the State in its extension request, i.e., in this case, by January 1, 2030.^[43] We interpret this criterion to mean that the State must demonstrate to the EPA's satisfaction that its Serious area plan includes the most stringent measures that are included in the implementation plan of any state, or achieved in practice in any state, and can feasibly be implemented in the area. The requirements that a State's MSM evaluation must satisfy are established in the PM_2.5 SIP Requirements Rule and are described in section III.C of this document.

The 2024 San Joaquin Valley PM_2.5 Plan discusses the Plan's control strategy, including compliance with the BACM and MSM requirements, in Appendices C and D, including analyses by the District and CARB, respectively, of source categories under their respective jurisdictions. Emissions inventories identifying sources of emissions of direct PM_2.5 and PM_2.5 precursors ^[44] in the San Joaquin Valley are described and included in Appendix B of the Plan. The evaluations of CARB and District measures each include the components of BACM and MSM evaluations as outlined in the PM_2.5 SIP Requirements Rule, generally: (1) an emissions inventory identifying sources of emissions of direct PM_2.5 and applicable precursors; (2) identifying potential control measures for the sources identified in step 1; (3) assessing the stringency and feasibility of the control measures identified in step 2; and (4) adoption and implementation of the feasible control measures identified in step 3.^[45]

CARB's demonstration includes descriptions of CARB's key mobile source programs and regulations and a comprehensive evaluation of on-road and non-road mobile source regulatory actions taken by CARB and other states. Based on its review, CARB determined that its control program for sources under its jurisdiction satisfies BACM and MSM requirements.

The District followed a similar process to identify candidate BACM/MSM measures that are technologically and economically feasible for stationary and area sources under its jurisdiction. The District structured its evaluation around its existing control program; for each existing District rule, the District identified the affected sources and associated emissions of direct PM_2.5 and NO_X, identified potential opportunities for further emissions reductions by comparing the District rule to Federal and State rules and regulations and rules in other California air districts (as well as potential new technologies not yet required in other areas, in some instances) and evaluated technological and economic feasibility of each potential emissions reduction opportunity. For most source categories, the District found that its existing control measures provide the maximum degree of emission reduction required or implemented in any other area. For all identified potential emission reduction opportunities, the District concluded that the potential measure was infeasible due to economic and/or technological considerations. Thus, the District concluded that, for all sources of direct PM_2.5 or PM_2.5 precursors in the San Joaquin Valley nonattainment area, the District's existing control program provides for the maximum degree of emission reduction that has been required or achieved in other areas that can feasibly be implemented in the nonattainment area and therefore meets or exceeds BACM and MSM requirements.

Based upon our review, the EPA has determined that the 2024 San Joaquin Valley PM_2.5 Plan contains the required elements of BACM and MSM evaluations as defined in the PM_2.5 SIP Requirements Rule. The emissions inventory identifies all sources of emissions of direct PM_2.5 and applicable PM_2.5 precursors. For the source categories identified in the emissions inventory for the nonattainment area, CARB and the District followed EPA guidance to identify potential measures from other areas' control requirements for similar sources, the EPA's technical support documents from rulemakings on SJVUAPCD control measure SIP submittals, potential control measures identified in previous SJVUAPCD plan submittals, the EPA's menu of control measures, and EPA guidance documents.

Our review indicates that CARB and the District conducted thorough analyses of emissions sources in the nonattainment area and potential control measures for those sources. We note that EPA last approved SJVUAPCD's control program as satisfying BACM and MSM in our final rule granting a CAA section 188(e) attainment date extension for the San Joaquin Valley 2006 PM_2.5 nonattainment area on July 22, 2020.^[46] Parts of EPA's analysis were challenged and ultimately upheld in the Ninth Circuit Court of Appeals.^[47] The EPA is not aware of more stringent and feasible measures implemented in other areas of the country beyond those included in the 2024 San Joaquin Valley PM_2.5 Plan. Based on our evaluation of the current submission, as supported by the analysis conducted in our previous 2020 evaluation, our review of the 2024 San Joaquin Valley PM_2.5 Plan indicates that the Plan includes the requisite BACM demonstration and includes the MSM that are included in the implementation plan of any state, or are achieved in practice in any state, and can feasibly be implemented in the area.

( printed page 35444)

D. Demonstration of Attainment by the Most Expeditious Alternative Date Practicable

Section 188(e) of the Act states that at the time of its application for an extension of an attainment deadline, the State must submit a demonstration of attainment by the most expeditious alternative date practicable and that the EPA may not approve the extension until such a demonstration has been submitted. Section 189(b)(1)(A)(ii) of the CAA also provides that a State seeking an extension of the attainment date under CAA section 188(e) must submit a demonstration that the plan provides for attainment by the most expeditious alternative date practicable.

For the purpose of the CAA section 188(e) requirement that the District submit a demonstration that the plan provides for attainment by the most expeditious alternative date practicable, the EPA's review of the submission indicates that the submission contains the requisite demonstration. Chapter 5.2.4.2 and Appendix J of the 2024 San Joaquin Valley PM_2.5 Plan contain the State's demonstration that the implementation of all feasible control measures in the San Joaquin Valley, as required in the Plan, will provide for attainment of the 2012 annual PM_2.5 NAAQS in the San Joaquin Valley as expeditiously as practicable, i.e., by December 31, 2030. Furthermore, the District cites Appendix G of the Plan as validating the assertion in the Plan that the San Joaquin Valley will attain the standard as expeditiously as practicable.^[48] Appendix G addresses the reasonable further progress, quantitative milestone, and contingency measure requirements and includes an evaluation of potential control measures for consideration as contingency measures. As a result of this evaluation, the District concludes that the District and CARB are currently implementing the most stringent measures feasible, and no opportunities exist for additional measures beyond those adopted in the Plan, supporting the District's position that the San Joaquin Valley could not practicably attain the 2012 annual PM_2.5 NAAQS sooner than December 31, 2030, as projected in the attainment demonstration in the Plan. In addition, the RFP demonstration in Appendix G reports the most expeditious timeline by which the San Joaquin Valley can achieve emissions reductions from the implementation of BACM and MSM in light of factors such as the timeline required for the development, adoption, and implementation of the rules included in the Plan, supporting the District's position that the San Joaquin Valley could not practicably attain the 2012 annual PM_2.5 NAAQS sooner than December 31, 2030, as projected in the attainment demonstration in the Plan.

While the EPA will evaluate this analysis in a future rulemaking action, for the purpose of the CAA section 188(e) extension prerequisite that a complete submission from the State must contain the requisite demonstration under CAA section 189(b)(1)(A)(ii), our review of the 2024 San Joaquin Valley PM_2.5 Plan indicates that the State has made such a submission.

E. Application for an Attainment Date Extension

As discussed in section I.B of this document, the Serious area attainment date for the San Joaquin Valley for the 2012 annual PM_2.5 NAAQS under CAA section 188(c)(2) is December 31, 2025. The remaining criterion for an extension of the attainment date beyond this statutory attainment date is that the State must apply for such extension. In the 2024 San Joaquin Valley PM_2.5 Plan, CARB and SJVUAPCD submitted a complete application for an extension of the Serious area attainment date for the San Joaquin Valley to December 31, 2030, for the 2012 annual PM_2.5 NAAQS.^[49] In accordance with the requirements of the PM_2.5 SIP Requirements Rule in 40 CFR 51.1005(b)(1), the State's submission includes demonstrations that attainment by the Serious area attainment date is impracticable, that the State has complied with all requirements and commitments in the applicable SIP, and that the plan includes MSM. Additionally, in accordance with 40 CFR 51.1005(b)(2), the 2024 San Joaquin Valley PM_2.5 Plan contains all of the required components of a Serious area plan accompanying a request for extension of the attainment date under CAA section 188(e), as follows: (1) base year and attainment projected emissions inventories, (2) provisions to implement MSM and BACM, (3) a modeled attainment demonstration, (4) RFP provisions, (5) quantitative milestone provisions, (6) contingency measure provisions, and (7) nonattainment new source review plan provisions.^[50] As discussed in section II of this document, the EPA previously found that the State provided the public reasonable notice and an opportunity for a public hearing on the 2024 San Joaquin Valley PM_2.5 Plan, including the attainment date extension request, before submitting it to the EPA, in accordance with the requirements for SIP revisions in CAA section 110.

F. Other Factors That the EPA May Consider

Finally, as noted section III of this document, CAA section 188(e) lists five additional factors that the EPA may consider in deciding whether to grant an attainment date extension and the length for such extension. These factors include: (1) the nature and extent of the nonattainment problem; (2) the types and numbers of sources or other emitting activities in the area (including the influence of uncontrollable natural sources and international transport); (3) the population exposed to concentrations in excess of the standard; (4) the presence and concentration of potentially toxic substances in the mix of particulate emissions in the area; and (5) the technological and economic feasibility of various control measures. In evaluating these factors, we have focused on the nature and extent of the nonattainment area problem and the technological and economic feasibility of additional control measures.

The San Joaquin Valley Air Basin has made significant progress towards improving air quality and meeting the NAAQS despite the Valley's vast population and the unique meteorological and topographical factors that result in the highest levels of ambient PM_2.5 levels on an annual basis in the country.^[51] In the years prior to the adoption of the 2024 San Joaquin Valley PM_2.5 Plan, CARB and the District developed and implemented several comprehensive plans ( e.g., the 2016 PM_2.5 Plan and 2018 PM_2.5 Plan) to provide for attainment of PM_2.5 and ozone NAAQS. These plans have resulted in the adoption and implementation of many new rules and amendments to existing rules across source categories. These regulations and strategies have yielded significant reductions from sources under the ( printed page 35445) State's and District's jurisdictions. As a result of these already-adopted State and District measures, sources in the San Joaquin Valley nonattainment area are already subject to the most stringent rules in the country, leaving fewer viable opportunities to reduce emissions in light of the extreme technological and economic challenges present in the nonattainment area, as demonstrated by the controls analysis in the 2024 San Joaquin Valley PM_2.5 Plan.^[52] The State and District continue to pursue new opportunities to achieve further reductions in direct PM_2.5 and PM_2.5 precursor emissions, as outlined in the Plan; ^[53] however, the EPA acknowledges the scarcity of additional controls and the timeline needed to develop, adopt, and implement such measures. These factors generally support a longer time frame for attainment.

V. Summary of Proposed Action and Request for Public Comment

For the reasons discussed in this proposed rulemaking, the EPA is proposing to grant the State's request for an extension of the Serious area attainment date from December 31, 2025, to December 31, 2030, based on a conclusion that the State has satisfied the requirements for such an extension in section 188(e) of the Act.

The EPA is soliciting public comments on the issues discussed in this document. We will accept comments from the public on this proposal for the next 30 days.

VI. Statutory and Executive Order Reviews

Additional information about these statutes and Executive Orders can be found at https://www.epa.gov/​laws-regulations/​laws-and-executive-orders.

A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review

This action is not a significant regulatory action and was therefore not submitted to the Office of Management and Budget (OMB) for review.

B. Executive Order 14192: Unleashing Prosperity Through Deregulation

This action is not expected to be an Executive Order 14192 regulatory action because this action is not significant under Executive Order 12866.

C. Paperwork Reduction Act (PRA)

This action does not impose an information collection burden under the PRA because this action does not impose additional requirements beyond those imposed by State law.

D. Regulatory Flexibility Act (RFA)

I certify that this action will not have a significant economic impact on a substantial number of small entities under the RFA. This action will not impose any requirements on small entities beyond those imposed by State law.

E. Unfunded Mandates Reform Act (UMRA)

This action does not contain any unfunded mandate as described in UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect small governments. This action does not impose additional requirements beyond those imposed by State law. Accordingly, no additional costs to State, local, or Tribal governments, or to the private sector, will result from this action.

F. Executive Order 13132: Federalism

This action does not have federalism implications. It will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.

G. Executive Order 13175: Coordination With Indian Tribal Governments

This action does not have Tribal implications, as specified in Executive Order 13175, because 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, and will not impose substantial direct costs on Tribal governments or preempt Tribal law. Thus, Executive Order 13175 does not apply to this action.

H. Executive Order 13045: Protection of Children From Environmental Health Risks and Safety Risks

The EPA interprets Executive Order 13045 as applying only to those regulatory actions that concern environmental health or safety risks that the EPA has reason to believe may disproportionately affect children, per the definition of “covered regulatory action” in section 2-202 of the Executive Order. Therefore, this action is not subject to Executive Order 13045 because it merely proposes to approve a State request for an attainment date extension as meeting Federal requirements. Furthermore, the EPA's Policy on Children's Health does not apply to this action.

I. Executive Order 13211: Actions That Significantly Affect Energy Supply, Distribution, or Use

This action is not subject to Executive Order 13211 because it is not a significant regulatory action under Executive Order 12866.

J. National Technology Transfer and Advancement Act (NTTAA)

Section 12(d) of the NTTAA directs the EPA to use voluntary consensus standards in its regulatory activities unless to do so would be inconsistent with applicable law or otherwise impractical. The EPA believes that this action is not subject to the requirements of section 12(d) of the NTTAA because application of those requirements would be inconsistent with the CAA.

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

91 FR 35437