Clean Air Plans; 2012 Fine Particulate Matter Serious Nonattainment Area Requirements; San Joaquin Valley, California

Federal RegisterDec 29, 2021

Ask Donna

What actually matters in this document.

Text

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R09-OAR-2021-0884; FRL-9292-01-R9]

Clean Air Plans; 2012 Fine Particulate Matter Serious Nonattainment Area Requirements; San Joaquin Valley, California

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

The Environmental Protection Agency (EPA or “Agency”) proposes to approve portions of two state implementation plan (SIP) revisions submitted by the State of California to meet Clean Air Act (CAA or “Act”) requirements for the 2012 annual fine particulate matter (PM

2.5

) national ambient air quality standards (NAAQS or “standards”) in the San Joaquin Valley (SJV) Serious nonattainment area. Specifically, the EPA proposes to approve the State's Serious area plan for the 2012 annual PM

2.5

NAAQS, submitted May 10, 2019, for all Serious PM

2.5

area requirements (except contingency measures), including emissions inventories, best available control measures, demonstrations of attainment and reasonable further progress, quantitative milestones, and motor vehicle emission budgets. We may, however, reconsider this proposal if, based on new information or public comments, we find that the State has not satisfied the statutory criteria for a Serious area PM

2.5

attainment plan. The EPA also proposes to disapprove the portions of the State's Serious area plan, and the contingency provisions of a third SIP submission regarding residential wood burning, that pertain to the Serious area contingency measurement requirements for the 2012 annual PM

2.5

NAAQS.

DATES:

Any comments must arrive by January 28, 2022.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-R09-OAR-2021-0884, at

https://www.regulations.gov.

For comments submitted at

Regulations.gov

, follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from

Regulations.gov

. The EPA may publish any comment received to its public docket. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Multimedia submissions (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

https://www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT:

Rory Mays, Air Planning Office (AIR-2), EPA Region IX, (415) 972-3227,

mays.rory@epa.gov.

SUPPLEMENTARY INFORMATION:

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

Table of Contents

I. Background for Proposed Action

II. Summary and Completeness Review of Applicable SIP Submissions

A. San Joaquin Valley 2018 PM

2.5

Plan

B. Valley State SIP Strategy

C. Rule 4901 Contingency Provision

III. Clean Air Act Requirements for PM

2.5

Serious Area Plans

IV. Review of the San Joaquin Valley PM

2.5

Serious Area Plan

A. Emissions Inventory

B. PM

2.5

Precursors

C. Air Quality Modeling

D. Best Available Control Measures

E. Nonattainment New Source Review Requirements Under CAA Section 189(e)

F. Attainment Demonstration

G. Reasonable Further Progress and Quantitative Milestones

H. Contingency Measures

I. Motor Vehicle Emission Budgets

V. Summary of Proposed Actions and Request for Public Comment

VI. Statutory and Executive Order Reviews

I. Background for Proposed Action

On January 15, 2013, the EPA strengthened the primary annual NAAQS for particulate matter with a diameter of 2.5 microns or less (PM

2.5

) by lowering the level from 15.0 micrograms per cubic meter (µg/m

) to 12.0 µg/m

(“2012 annual PM

2.5

NAAQS”).

The EPA established these standards 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.

78 FR 3086 and 40 CFR 50.18. The EPA first established NAAQS for PM

2.5

on July 18, 1997 (62 FR 38652), including annual standards of 15.0 µg/m

based on a 3-year average of annual mean concentrations and 24-hour (daily) standards of 65 µg/m

based on a 3-year average of 98th percentile 24-hour concentrations (40 CFR 50.7) (“1997 PM

2.5

NAAQS”). In addition, on October 17, 2006, the EPA strengthened the 24-hour (daily) NAAQS for PM

2.5

by lowering the level from 65 µg/m

to 35 µg/m

(“2006 24-hour PM

2.5

NAAQS”). 71 FR 61144 and 40 CFR 50.13. Unless otherwise noted, all references to the PM

2.5

standards in this notice, including all instances of “2012 annual PM

2.5

NAAQS,” are to the 2012 primary annual NAAQS of 12.0 µg/m

codified at 40 CFR 50.18.

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 days), 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.

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 it can form in the atmosphere (“secondary PM

2.5

”) as a result of various chemical reactions among precursor pollutants such as nitrogen oxides (NO

), sulfur oxides (SO

), volatile organic compounds (VOC), and ammonia (NH

78 FR 3086, 3088.

EPA, Air Quality Criteria for Particulate Matter, No. EPA/600/P-99/002aF and EPA/600/P-99/002bF, October 2004.

Following promulgation of a new or revised NAAQS, the EPA is required by 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 SJV as Moderate nonattainment for the 2012 annual PM

2.5

NAAQS.

The EPA has approved the State's demonstration that it was impracticable to attain the 2012 annual PM

2.5

NAAQS by the outermost December 31, 2021 Moderate area attainment date and related plan elements addressing the Moderate area requirements for the 2012 annual PM

2.5

NAAQS, except for the contingency measure element, which the EPA disapproved.

In that same action, the EPA reclassified the SJV as a Serious nonattainment area for these NAAQS.

80 FR 2206 (codified at 40 CFR 81.305).

86 FR 67343 (November 26, 2021).

On December 27, 2021, the effective date of the SJV's reclassification as a Serious PM

2.5

nonattainment area, the SJV will become subject to a new statutory attainment date no later than the end of the tenth calendar year following designation (

i.e.,

December

31, 2025) and the 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.

As explained in the EPA's final reclassification action, the Serious area plan for the SJV 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 but no later than December 31, 2025, or by the most expeditious alternative date practicable and no later than December 31, 2030, in accordance with the requirements of CAA sections 189(b) and 188(e). As described in our final action reclassifying the SJV as a Serious PM

2.5

nonattainment area, California must adopt and submit a SIP submission addressing the Serious nonattainment area requirements for the 2012 annual PM

2.5

NAAQS within 18 months (

i.e.,

by June 27, 2023), for emissions inventories, BACM, and nonattainment new source review (NSR), and by December 31, 2023, for the attainment demonstration and related planning requirements.

Id. at 67347.

The SJV 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.

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. The CAA assigns primary responsibility to the state for developing plans to attain the NAAQS. Under State law, California divides this responsibility between the San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD or District) and the California Air Resources Board (CARB) in preparing attainment plans. Authority for regulating sources under state jurisdiction in the SJV 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.

For a precise description of the geographic boundaries of the SJV PM

2.5

nonattainment area, see 40 CFR 81.305.

II. Summary and Completeness Review of Applicable SIP Submissions

The EPA is proposing action on portions of three SIP revisions submitted by CARB to meet the Serious nonattainment area requirements for the 2012 annual PM

2.5

NAAQS in the SJV. Specifically, the EPA is proposing to act on those portions of the following two plan submissions that pertain to the Serious area requirements for the 2012 annual PM

2.5

NAAQS: The “2018 Plan for the 1997, 2006, and 2012 PM

2.5

Standards,” adopted by the SJVUAPCD on November 15, 2018, and by CARB on January 24, 2019 (“2018 PM

2.5

Plan”);

and the “San Joaquin Valley Supplement to the 2016 State Strategy for the State Implementation Plan,” adopted by CARB on October 25, 2018 (“Valley State SIP Strategy”).

The 2018 PM

2.5

Plan was developed jointly by CARB and the District.

We refer to the relevant portions of these SIP submissions collectively in this proposal as the “SJV PM

2.5

Plan” or “Plan.” The SJV PM

2.5

Plan addresses attainment plan requirements for multiple PM

2.5

NAAQS in the SJV, including the Serious area attainment plan requirements for the 2012 annual PM

2.5

NAAQS. CARB submitted the SJV PM

2.5

Plan to the EPA as a revision to the California SIP on May 10, 2019.

It became complete by operation of law on November 10, 2019.

Letter dated May 9, 2019, from Richard W. Corey, Executive Officer, CARB, to Mike Stoker, Regional Administrator, EPA Region IX. Previously, in separate rulemakings, the EPA has finalized action on the portions of the SJV PM

2.5

Plan that pertain to the 1997 annual PM

2.5

NAAQS, the 2006 24-hour PM

2.5

NAAQS, and the Moderate area plan for the 2012 annual PM

2.5

NAAQS. See 86 FR 67329 (November 26, 2021) (final rule regarding the 1997 annual PM

2.5

NAAQS); 85 FR 44192 (July 22, 2020) (final rule regarding the 2006 24-hour PM

2.5

NAAQS, except contingency measures); and 86 FR 67343 (final rule regarding the Moderate area plan for the 2012 annual PM

2.5

NAAQS and contingency measures for the 2006 24-hour PM

2.5

NAAQS). The EPA has also separately proposed action on the portions of the SJV PM

2.5

Plan that pertain to the 1997 24-hour PM

2.5

NAAQS. 86 FR 53150 (September 24, 2021).

We note that, with respect to plans previously required for the 1997, 2006, and 2012 PM

2.5

NAAQS, including the Moderate area plan only for the 2012 annual PM

2.5

NAAQS, the EPA had made findings of failure to submit effective January 7, 2019, that triggered sanctions clocks. 83 FR 62720 (December 6, 2018). Following the May 10, 2019 submission of the 2018 PM

2.5

Plan and Valley State SIP Strategy, the EPA affirmatively determined that the SIP submissions addressed the deficiency that was the basis for such findings, resulting in the termination of the associated sanctions clocks. Letter dated June 24, 2020, from Elizabeth Adams, Director, Air and Radiation Division, EPA Region IX, to Richard W. Corey, Executive Officer, CARB. However, neither the findings nor completeness determination applied to the Serious area plan for the 2012 annual PM

2.5

NAAQS as it was not yet required.

In addition, the EPA is proposing action on the portion of a third SIP submission that pertains to SJVUAPCD Rule 4901, as amended by the District on June 20, 2019, and submitted to the EPA on July 19, 2019 (“Rule 4901 Contingency Provision”). The EPA has already taken final action on the rule modification for this submission.

In this action we are evaluating the submission for purposes of addressing the contingency measures requirement in the SJV for the 2012 annual PM

2.5

NAAQS.

85 FR 44206 (July 22, 2020) (final approval of District Rule 4901); 85 FR 1131, 1132-33 (January 9, 2020) (proposed approval of District Rule 4901). Completeness review for this submission was conducted and described in that action. See also 86 FR 67329 (removing the contingency provision from the SIP).

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 adequate public notice was given and that an opportunity for a public hearing was provided consistent with the EPA's implementing regulations in 40 CFR 51.102.

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.

A. San Joaquin Valley 2018 PM

2.5

Plan

The following portions of the 2018 PM

2.5

Plan and related support documents address the Serious area requirements for the 2012 annual PM

2.5

NAAQS in the SJV: (i) Chapter 4 (“Attainment Strategy for PM

2.5

”); (ii) Chapter 7 (“Demonstration of Federal Requirements for the 2012 PM

2.5

Standard”);

(iii) numerous appendices to the 2018 PM

2.5

Plan; (iv) CARB's “Staff Report, Review of the San Joaquin Valley 2018 Plan for the 1997, 2006, and 2012 PM

2.5

Standards,” release date December 21, 2018 (“CARB

Staff Report”);

and (v) the State's and District's board resolutions adopting the 2018 PM

2.5

Plan (CARB Resolution 19-1 and SJVUAPCD Governing Board Resolution 18-11-16).

The SJVUAPCD Governing Board Resolution 18-11-16 includes emission reduction commitments on which the SJV PM

2.5

Plan relies.

Chapter 5 (“Demonstration of Federal Requirements for the 1997 PM

2.5

Standard”) and Chapter 6 (“Demonstration of Federal Requirements for the 2006 PM

2.5

Standard”) of the 2018 PM

2.5

Plan pertain to the 1997 PM

2.5

NAAQS and 2006 24-hour PM

2.5

NAAQS, respectively.

The CARB Staff Report includes CARB's review of, among other things, the 2018 PM

2.5

Plan's control strategy and attainment demonstration. Letter dated December 11, 2019, from Richard W. Corey, Executive Officer, CARB to Mike Stoker, Regional Administrator, EPA Region IX, transmitting the CARB Staff Report.

CARB Resolution 19-1, “2018 PM

2.5

State Implementation Plan for the San Joaquin Valley,” January 24, 2019, and SJVUAPCD Governing Board Resolution 18-11-16, “Adopting the [SJVUAPCD] 2018 Plan for the 1997, 2006, and 2012 PM

2.5

Standards,” November 15, 2018.

SJVUAPCD Governing Board Resolution 18-11-16, paragraph 6, 10-11.

The appendices to the 2018 PM

2.5

Plan, in order of their evaluation in this proposed rule, include: (i) App. B (“Emissions Inventory”); (ii) App. A (“Ambient PM

2.5

Data Analysis”); (iii) a plan precursor demonstration and clarifications, including App. G (“Precursor Demonstration”) and Attachment A (“Clarifying information for the San Joaquin Valley 2018 Plan regarding model sensitivity related to ammonia and ammonia controls”) to the CARB Staff Report; (iv) control strategy appendices, including App. C (“Stationary Source Control Measure Analyses”), App. D (“Mobile Source Control Measures Analyses”), and App. E (“Incentive-Based Strategy”); (v) modeling appendices, including App. J (“Modeling Emission Inventory”), App. K (“Modeling Attainment Demonstration”), and App. L (“Modeling Protocol”); (vi) App. H (“RFP, Quantitative Milestones, and Contingency”); and (vii) App. I (“New Source Review and Emission Reduction Credits”). The 2018 PM

2.5

Plan addresses motor vehicle emission budget requirements in the “Transportation Conformity” section of App. D (pages D-119 to D-131). The 2018 PM

2.5

Plan also includes an Executive Summary, Introduction (Ch. 1), chapters on “Air Quality Challenges and Trends” (Ch. 2) and “Health Impacts and Health Risk Reduction Strategy” (Ch. 3), and an appendix on “Public Education and Technology Advancement” (App. F).

The District provided public notice and opportunity for public comment prior to its November 15, 2018 public hearing on and adoption of the 2018 PM

2.5

Plan.

CARB also provided public notice and opportunity for public comment prior to its January 24, 2019 public hearing on and adoption of the 2018 PM

2.5

Plan.

The SIP submission includes proof of publication of notices for the respective public hearings. It also includes copies of the written and oral comments received during the State's and District's public review processes and the agencies' responses thereto.

Therefore, we reaffirm that the 2018 PM

2.5

Plan meets the procedural requirements for public notice and hearing in CAA sections 110(a) and 110(l) and 40 CFR 51.102. The 2018 PM

2.5

Plan became complete by operation of law on November 10, 2019, pursuant to CAA section 110(k)(1)(B).

SJVUAPCD, “Notice of Public Hearing for Adoption of Proposed 2018 PM

2.5

Plan for the 1997, 2006, and 2012 Standards,” October 16, 2018, and SJVUAPCD Governing Board Resolution 18-11-16.

CARB, “Notice of Public Meeting to Consider the 2018 PM

2.5

State Implementation Plan for the San Joaquin Valley,” December 21, 2018, and CARB Resolution 19-1.

CARB, “Board Meeting Comments Log,” March 29, 2019; J&K Court Reporting, LLC, “Meeting, State of California Air Resources Board,” January 24, 2019 (transcript of CARB's public hearing), and 2018 PM

2.5

Plan, App. M (“Summary of Significant Comments and Responses”).

B. Valley State SIP Strategy

CARB developed the “Revised Proposed 2016 State Strategy for the State Implementation Plan” (“2016 State Strategy”) to support attainment planning in the SJV and Los Angeles-South Coast Air Basin (“South Coast”) ozone nonattainment areas.

In its resolution adopting the 2016 State Strategy (CARB Resolution 17-7), the Board found that the 2016 State Strategy would achieve 6 tons per day (tpd) of NO

emission reductions and 0.1 tpd of direct PM

2.5

emission reductions in the SJV by 2025 from source categories under the regulatory authority of CARB. The resolution directed CARB staff to work with the SJVUAPCD to identify additional reductions from sources under District regulatory authority as part of a comprehensive plan to attain all of the PM

2.5

NAAQS for the SJV and to return to the Board with a commitment to achieve additional emission reductions from mobile sources.

The EPA has approved certain commitments made by CARB in the 2016 State Strategy for purposes of attaining the ozone NAAQS in the SJV and South Coast ozone nonattainment areas. See,

e.g.,

84 FR 3302 (February 12, 2019) and 84 FR 52005 (October 1, 2019).

CARB Resolution 17-7, “2016 State Strategy for the State Implementation Plan,” March 23, 2017, 6-7.

CARB responded to this resolution by developing and adopting the “San Joaquin Valley Supplement to the 2016 State Strategy for the State Implementation Plan” (“Valley State SIP Strategy”) to support the 2018 PM

2.5

Plan. The State's May 10, 2019 SIP submission incorporates by reference the Valley State SIP Strategy as adopted by CARB on October 25, 2018, and submitted to the EPA on November 16, 2018.

Letter dated May 9, 2019, from Richard W. Corey, Executive Officer, CARB, to Mike Stoker, Regional Administrator, EPA Region IX, 2.

The Valley State SIP Strategy includes an Introduction (Ch. 1), a chapter on “Measures” (Ch. 2), and a “Supplemental State Commitment from the Proposed State Measures for the Valley” (Ch. 3). Much of the content of the Valley State SIP Strategy is reproduced in Chapter 4 (“Attainment Strategy for PM

2.5

”) of the 2018 PM

2.5

Plan.

The Valley State SIP Strategy also includes CARB Resolution 18-49, which, among other things, commits CARB to achieve specific amounts of NO

and PM

2.5

emission reductions by specific years, for purposes of attaining the PM

2.5

NAAQS in the SJV.

For example, Table 2 (proposed mobile source measures and schedule), Table 3 (emissions reductions from proposed mobile source measures), and Table 4 (summary of emission reduction measures) of the Valley State SIP Strategy correspond to tables 4-8, 4-9, and 4-7, respectively, of the 2018 PM

2.5

Plan, Chapter 4.

CARB Resolution 18-49, “San Joaquin Valley Supplement to the 2016 State Strategy for the State Implementation Plan,” October 25, 2018, 5.

CARB provided the required public notice and opportunity for public comment prior to its October 25, 2018 public hearing on and adoption of the Valley State SIP Strategy.

The SIP submission includes proof of publication of the public notice for this public hearing. It also includes copies of the written and oral comments received during the State's public review process and CARB's responses thereto.

Therefore, we reaffirm that the Valley State SIP Strategy meets the procedural requirements for public notice and hearing in CAA sections 110(a) and 110(l) and 40 CFR 51.102. The Valley State SIP Strategy became complete by operation of law on November 10, 2019, pursuant to CAA section 110(k)(1)(B).

CARB, “Notice of Public Meeting to Consider the San Joaquin Valley Supplement to the 2016 State Strategy for the State Implementation Plan,” September 21, 2018, and CARB Resolution 18-49.

CARB, “Board Meeting Comments Log,” November 2, 2018 and compilation of written comments; and J&K Court Reporting, LLC, “Meeting, State of California Air Resources Board,” October 25, 2018 (transcript of CARB's public hearing).

C. Rule 4901 Contingency Provision

Lastly, the 2018 PM

2.5

Plan addresses the contingency measure requirements for the 2012 annual PM

2.5

NAAQS by reference to, among other things, a District contingency measure, and

emissions estimates for the year following the attainment year for use in evaluating whether the emissions reductions from the contingency measure are sufficient.

With respect to the District contingency measure, the 2018 PM

2.5

Plan calls for the District to amend District Rule 4901 (“Wood Burning Fireplaces and Wood Burning Heaters”) to include a provision in the rule with a trigger that would activate the requirements of the contingency measure should the EPA issue a determination or final rulemaking that the SJV failed to meet a regulatory requirement necessitating implementation of a contingency measure.

2018 PM

2.5

Plan, App. H (revised February 11, 2020), H-24 to H-26.

In response to the commitment made in the 2018 PM

2.5

Plan, in June 2019 the District adopted amendments to Rule 4901, including a new provision (codified as section 5.7.3 of the amended rule) that is structured to function as a contingency measure. On July 19, 2019, CARB submitted the amended rule to the EPA for approval.

The EPA took final action to approve the amended Rule 4901 (including the new section 5.7.3) into the California SIP, but in our approval we noted that we were not evaluating the contingency measure in section 5.7.3 of revised Rule 4901 for compliance with all requirements of the CAA and the EPA's implementing regulations that apply to such measures.

Rather, we approved the new provision (section 5.7.3) into the SIP as part of our approval of the entire amended rule as SIP strengthening because the provision strengthens the rule by providing a possibility of additional curtailment days and thus potentially additional emissions reductions. We indicated that we would evaluate whether section 5.7.3, in conjunction with other submitted provisions, meets the statutory and regulatory requirements for contingency measures in a future action.

In this document, we are evaluating District Rule 4901, and in particular section 5.7.3, in the context of our action on the contingency measure element in the 2018 PM

2.5

Plan for the 2012 annual PM

2.5

NAAQS.

Letter dated July 19, 2019, from Richard W. Corey, Executive Officer, CARB, to Mike Stoker, Regional Administrator, EPA Region IX.

85 FR 44206 (July 22, 2020) (final approval of District Rule 4901); 85 FR 1131, 1132-33 (January 9, 2020) (proposed approval of District Rule 4901).

The EPA subsequently removed section 5.7.3 of Rule 4901 from the California SIP. 86 FR 67329 (final rule on 1997 annual PM

2.5

NAAQS portion of the SJV PM

2.5

Plan, including final disapproval of the contingency measures element for those NAAQS).

III. Clean Air Act Requirements for PM

2.5

Serious Area Plans

Upon reclassification of a Moderate nonattainment area as a Serious nonattainment area under subpart 4 of part D, title I of the CAA, the Act requires the state to make a SIP submission that addresses the following Serious nonattainment area requirements:

81 FR 58010, 58074-58075 (August 24, 2016).

(1) A comprehensive, accurate, current inventory of actual emissions from all sources of PM

2.5

and PM

2.5

precursors in the area (CAA section 172(c)(3));

(2) Provisions to assure that the best available control measures (BACM), including best available control technology (BACT), for the control of direct PM

2.5

and all PM

2.5

precursors shall be implemented no later than four years after the area is reclassified (CAA section 189(b)(1)(B)), unless the state elects to make an optional precursor demonstration that the EPA approves authorizing the state not to regulate one or more of these pollutants;

(3) A demonstration (including air quality modeling) that the plan provides for attainment as expeditiously as practicable but no later than the end of the tenth calendar year after designation as a nonattainment area (

i.e.,

December 31, 2025, for the SJV for the 2012 annual PM

2.5

NAAQS) (CAA sections 188(c)(2) and 189(b)(1)(A)(i));

(4) Plan provisions that require reasonable further progress (RFP) (CAA section 172(c)(2));

(5) Quantitative milestones which are to be achieved every three years until the area is redesignated attainment and which demonstrate RFP toward attainment by the applicable date (CAA section 189(c));

(6) Provisions to assure that control requirements applicable to major stationary sources of PM

2.5

also apply to major stationary sources of PM

2.5

precursors, except where the state demonstrates to the EPA's satisfaction that such sources do not contribute significantly to PM

2.5

levels that exceed the standard in the area (CAA section 189(e));

(7) Contingency measures to be implemented if the area fails to meet RFP or to attain by the applicable attainment date (CAA section 172(c)(9)); and

(8) A revision to the nonattainment new source review (NSR) program to lower the applicable “major stationary source”

thresholds from 100 tons per year (tpy) to 70 tpy (CAA section 189(b)(3)).

For any Serious area, the terms “major source” and “major stationary source” include any stationary source that emits or has the potential to emit at least 70 tons per year of PM

2.5

. CAA section 189(b)(3) and 40 CFR 51.165(a)(1)(iv)(A)(

)(

vii

) and (

viii

) (defining “major stationary source” in serious PM

2.5

nonattainment areas).

A state's Serious area plan must also satisfy the requirements for Moderate area plans in CAA section 189(a), to the extent the state has not already met those requirements in the Moderate area plan submitted for the area. In addition, the state's Serious area plan must meet the general requirements applicable to all SIP submissions under section 110 of the CAA, including the requirement to provide necessary assurances that the implementing agencies have adequate personnel, funding, and authority under section 110(a)(2)(E); and the requirements concerning enforcement provisions in section 110(a)(2)(C).

The EPA provided its preliminary views on the CAA's requirements for particulate matter plans under part D, title I of the Act in the following guidance documents: (1) “State Implementation Plans; General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990” (“General Preamble”);

(2) “State Implementation Plans; General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990; Supplemental” (“General Preamble Supplement”);

and (3) “State Implementation Plans for Serious PM-10 Nonattainment Areas, and Attainment Date Waivers for PM-10 Nonattainment Areas Generally; Addendum to the General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990” (“General Preamble Addendum”).

More recently, 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”), 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.

We discuss these regulatory requirements and interpretations of the Act as appropriate in our evaluation of the State's submissions below.

57 FR 13498 (April 16, 1992).

57 FR 18070 (April 28, 1992).

59 FR 41998 (August 16, 1994).

81 FR 58010.

IV. Review of the San Joaquin Valley PM

2.5

Serious Area Plan

A. Emissions Inventory

1. Requirements for Emissions Inventories

CAA section 172(c)(3) requires that each SIP include a comprehensive, accurate, current inventory of actual emissions from all sources of the relevant pollutant or pollutants in the nonattainment area. The EPA discussed the emissions inventory requirements that apply to PM

2.5

nonattainment areas, including Serious area requirements, in the PM

2.5

SIP Requirements Rule and codified these requirements in 40 CFR 51.1008.

The EPA has also issued guidance concerning emissions inventories for PM

2.5

nonattainment areas.

Id. at 58078-58079.

EPA, “Emissions Inventory Guidance for Implementation of Ozone and Particulate Matter National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations,” May 2017 (“Emissions Inventory Guidance”), available at

https://www.epa.gov/air-emissions-inventories/air-emissions-inventory-guidance-implementation-ozone-and-particulate.

The base year emissions inventory should provide a state's best estimate of actual emissions from all sources of the relevant pollutants in the area,

i.e.,

all emissions that contribute to the formation of a particular NAAQS pollutant. For the PM

2.5

NAAQS, the base year inventory must include direct PM

2.5

emissions, separately reported filterable and condensable PM

2.5

emissions,

and emissions of all chemical precursors to the formation of secondary PM

2.5

: Nitrogen oxides (NO

), sulfur dioxide (SO

), volatile organic compounds (VOC), and ammonia (NH

In addition, the emissions inventory base year for a Serious PM

2.5

nonattainment area must be one of the three years for which monitored data were used to reclassify the area to Serious, or another technically appropriate year justified by the state in its Serious area plan submission.

The Emissions Inventory Guidance identifies the types of sources for which the EPA expects states to provide condensable PM emission inventories. Emissions Inventory Guidance, section 4.2.1 (“Condensable PM Emissions”), 63-65.

40 CFR 51.1008.

40 CFR 51.1008(b)(1).

A state's SIP submission must include documentation explaining how it calculated emissions data for the inventory. In estimating mobile source emissions, a state should use the latest emissions models and planning assumptions available at the time it developed the submission. The latest EPA-approved version of California's mobile source emission factor model for estimating tailpipe, brake, and tire wear emissions from on-road mobile sources that was available during the State's and District's development of the SJV PM

2.5

Plan was EMFAC2014.

Following CARB's submission of the Plan, the EPA approved EMFAC2017, the latest revision to this motor vehicle emissions model for SIP purposes.

States are also required to use the EPA's “Compilation of Air Pollutant Emission Factors” (“AP-42”) road dust method for calculating re-entrained road dust emissions from paved roads.

80 FR 77337 (December 14, 2015). EMFAC is short for

ission

FAC

tor. The EPA announced the availability of the EMFAC2014 motor vehicle emissions model, effective on the date of publication in the

Federal Register

, for use in state implementation plan development and transportation conformity in California. We note that CARB's use of EMFAC2014 in developing the emission inventories for the Serious area plan for the 2012 annual PM

2.5

NAAQS preceded the requirement to adopt and submit such Serious area plan.

84 FR 41717 (August 15, 2019).

The EPA released an update to AP-42 in January 2011 that revised the equation for estimating paved road dust emissions based on an updated data regression that included new emission tests results. 76 FR 6328 (February 4, 2011). CARB used the revised 2011 AP-42 methodology in developing on-road mobile source emissions. “Miscellaneous Process Methodology 7.9 Entrained Road Travel, Paved Road Dust,” CARB, November 2016.

In addition to the base year inventory submitted to meet the requirements of CAA section 172(c)(3), the state must also submit a projected attainment year inventory and emissions projections for each RFP milestone year.

These future emissions projections are necessary components of the attainment demonstration required under CAA section 189(b)(1) and the demonstration of RFP required under section 172(c)(2).

Emissions projections for future years (which are referred to in the Plan as “forecasted inventories”) should account for, among other things, the ongoing effects of economic growth and adopted emissions control requirements. The state's SIP submission should include documentation to explain how it calculated the emissions projections. Where a state chooses to allow new major stationary sources or major modifications to use emission reductions credits (ERCs) that were generated through shutdown or curtailed emissions units occuring before the base year of an attainment plan, the projected emissions inventory used to develop the attainment demonstration must explicitly include the emissions from such previously shutdown or curtailed emissions units.

40 CFR 51.1008 and 51.1012. Also, see Emissions Inventory Guidance, section 3 (“SIP Inventory Requirements and Recommendations”).

40 CFR 51.1004, 51.1008, 51.1011, and 51.1012.

40 CFR 51.165(a)(3)(ii)(C)(

Summary of State's Submission

The State included summaries of the planning emissions inventories for direct PM

2.5

and all PM

2.5

precursors (NO

, SO

VOC,

and ammonia) and the documentation for the inventories for the SJV PM

2.5

nonattainment area in Appendix B (“Emissions Inventory”) and Appendix I (“New Source Review and Emission Reduction Credits”) of the 2018 PM

2.5

Plan. In addition, Appendix J (“Modeling Emission Inventory”) contains inventory documentation specific to the air quality modeling inventories. These portions of the 2018 PM

2.5

Plan contain annual average daily emission inventories for 2013 through 2028 projected from the 2012 actual emissions inventory,

including the 2013 base year, the 2019 and 2022 RFP milestone years, the 2025 Serious area attainment year, and a 2028 post-attainment RFP year. The State used both the annual average and the winter average daily inventories to evaluate emission sources for the 2012 annual PM

2.5

NAAQS in the 2018 PM

2.5

Plan.

The SJV PM

2.5

Plan generally uses “sulfur oxides” or “SO

” in reference to SO

as a precursor to the formation of PM

2.5

. We use SO

and SO

interchangeably throughout this notice.

The SJV PM

2.5

Plan generally uses “reactive organic gasses” or “ROG” in reference to VOC as a precursor to the formation of PM

2.5

. We use ROG and VOC interchangeably throughout this notice.

2018 PM

2.5

Plan, App. B, B-18.

Id. at App. B, B-19. The base year inventory is from CEIDARS and future year inventories were estimated using CEPAM, version 1.05.

The State selected 2013 for the base year emission inventory, building on the 2012 actual emissions inventory and considering available air quality data, trends, and field studies.

Specifically, the State worked with local air districts and selected 2012 for the actual emissions inventory as it aligned with the 2012 data collection year of the Multiple Air Toxics Exposure Study IV (MATES IV)

of the South Coast Air Quality Management District (SCAQMD) and to maintain consistency across various California air quality plans.

The State then projected the

2013 base year emissions inventory (also referred to as the planning emissions inventory), presented in Appendix B of the Plan, from that 2012 actual emission inventory. Regarding the modeling emissions inventory, developed from the base year emissions inventory, the State conducted its base case modeling using 2013 for several reasons: Analysis of air quality trends, adjusted for meteorology, that indicated 2013 as a year conducive to ozone and PM

2.5

formation; availability of research-grade measurements of two significant pollution episodes in the DISCOVER-AQ field study of January to February 2013; and the relatively high design values for 2013, making it a conservative choice for attainment modeling.

Id. at App. L, 11-12.

Additional information on the MATES IV study performed in 2012 is available at:

https://www.aqmd.gov/home/air-quality/air-quality-studies/health-studies/mates-iv.

SCAQMD performed the subsequent MATES V study in 2018 and issued the MATES V final report in August 2021. See

https://www.aqmd.gov/home/air-quality/air-quality-studies/health-studies/mates-v,

and “MATES V, Multiple Air Toxics Exposure Study in the South Coast AQMD, Final Report,” SCAQMD, August 2021.

2018 PM

2.5

Plan, App. B, B-18.

Id. at App. L, 12. The State presents further information in the “APPENDIX: San Joaquin Valley PM

2.5

SIP (2018)” of Appendix L, and highlights that 2013 was one of the worst years in the decade preceding 2018 for PM

2.5

pollution in the SJV, underscoring its use as a conservative base year for modeling attainment of the 2012 annual PM

2.5

NAAQS. 2018 PM

2.5

Plan, Ch. 7, 7-6.

In addition, simultaneously with submission of the 2018 PM

2.5

Plan, the State submitted the Moderate area plan for the SJV for the 2012 annual PM

2.5

NAAQS, adopted by the District in 2016, that similarly used 2013 for the base year emissions inventory (“2016 PM

2.5

Plan”). In that plan, the State included a modeling demonstration that it would be impracticable for the SJV to attain the 2012 annual PM

2.5

NAAQS by the outermost Moderate area attainment date of December 31, 2021.

The modeling demonstration used three overlapping design value periods covering 2010-2014 and the 2013 base year emissions inventory to model the ambient air quality in 2021.

2016 PM

2.5

Plan, Ch. 2, section 2.3 (“Summary of Modeling Results”) and App. A (“Air Quality Modeling”). The EPA has summarized the State's impracticability demonstration in greater detail in our proposed rule on the 2016 PM

2.5

Plan. 86 FR 49100, 49113 (September 1, 2021).

The State developed base year inventories in the 2018 PM

2.5

Plan for stationary sources using actual emissions reports made by facility operators. The State developed the base year emissions inventories for area sources using the most recent models and methodologies available at the time the State was developing the 2018 PM

2.5

Plan.

The 2018 PM

2.5

Plan includes background, methodology, and inventories of condensable and filterable PM

2.5

emissions from stationary point and non-point combustion sources that are expected to generate condensable PM

2.5

It provides filterable and condensable emissions estimates, expressed as annual PM

2.5

emissions (tons per year), for all of the identified source categories for the years relevant for the 2012 annual PM

2.5

NAAQS Serious area plan requirements, including the 2013 base year, the 2019 and 2022 RFP years, the 2025 Serious area attainment year, and a 2028 post-attainment RFP year.

2018 PM

2.5

Plan, App. B, section B.2 (“Emissions Inventory Summary and Methodology”).

Id. at App. B, B-42 to B-44.

CARB used EMFAC2014, which was the EPA-approved model at the time CARB developed and submitted the inventories, to estimate on-road motor vehicle emissions based on transportation activity data from the 2014 Regional Transportation Plans adopted by the transportation planning agencies in the SJV.

Re-entrained paved road dust emissions were calculated using a CARB methodology consistent with the EPA's AP-42 road dust methodology.

CARB also provided emissions inventories for non-road equipment, including aircraft, trains, recreational boats, construction equipment, and farming equipment, among others. CARB uses a suite of category-specific models to estimate non-road emissions for many categories and, where a new model was not available, used the OFFROAD2007 model.

Id. at App. B, B-37. We note that the vehicle miles traveled data used in the 2018 PM

2.5

Plan's emissions inventory is from the final 2017 Federal Transportation Improvement Program from each of the SJV's eight metropolitan planning organizations.

Id. at App. B, B-28.

Id. at App. B, B-38 through B-40. The EPA regulations refer to “non-road” vehicles and engines whereas CARB regulations refer to “Other Mobile Sources” or “off-road” vehicles and engines. These terms refer to the same types of vehicles and engines. We refer herein to such vehicles and engines as “non-road” sources.

CARB developed the emissions forecasts by applying growth and control profiles to the base year inventory. CARB's mobile source emissions projections take into account predicted activity rates and vehicle fleet turnover by vehicle model year and adopted controls.

In the 2018 PM

2.5

Plan, the District provides for use of pre-base year ERCs as offsets by accounting for such ERCs in the projected emissions inventory for the 2025 attainment year.

The Plan identifies growth factors, control factors, and estimated offset use between 2013 and 2025, for direct PM

2.5

, NO

, SO

, and VOC emissions by source category and lists all pre-base year ERCs issued by the District for PM

, SO

, and VOC emissions by facility.

Id. at App. B, B-19.

Id. at App. I, I-1 through I-5.

Particulate matter with a diameter of 10 microns or less.

2018 PM

2.5

Plan, App. I, tables I-1 through I-5.

Table 1 provides a summary of the 2018 PM

2.5

Plan's winter (24-hour) average inventories in tpd of direct PM

2.5

and PM

2.5

precursor emissions for the 2013 base year. Table 2 provides a summary of the 2018 PM

2.5

Plan's annual average inventories of direct PM

2.5

and PM

2.5

precursor emissions for the 2013 base year. For purposes of this proposal, these annual average inventories provide bases primarily for our evaluation of the precursor demonstration, control measure analysis, attainment demonstration, RFP demonstration, and motor vehicle emissions budgets (“budgets”) in the 2018 PM

2.5

Plan with respect to the Serious area attainment plan requirements for the 2012 annual PM

2.5

NAAQS.

Table 1—San Joaquin Valley Winter Average Emissions Inventory for Direct PM

2.5

and PM

2.5

Precursors for the 2013 Base Year

[tpd]

Category

Direct PM

2.5

VOC

Ammonia

Stationary Sources

8.8

38.6

7.2

87.1

13.9

Area Sources

41.5

8.1

0.3

153.4

310.9

On-Road Mobile Sources

6.4

183.1

0.6

49.8

4.4

Non-Road Mobile Sources

5.8

87.4

0.3

33.8

0.0

Totals

62.5

317.2

8.5

324.1

329.2

Source: 2018 PM

2.5

Plan, Appendix B, tables B-1 through B-5.

Totals reflect disaggregated emissions and may not add exactly as shown here due to rounding.

EPA Evaluation and Proposed Action

The inventories in the 2018 PM

2.5

Plan include the latest version of California's mobile source emissions model, EMFAC2014, that the EPA had approved at the time the State made the SIP submissions, and the EPA's most recent AP-42 methodology for paved road dust. The inventories comprehensively address all source categories in the SJV PM

2.5

nonattainment area and are consistent with the EPA's inventory guidance.

In accordance with 40 CFR 51.1008(b)(1), the EPA has evaluated the State's justification for using 2013 for the base year emissions inventory as a technically appropriate inventory year for the 2012 annual PM

2.5

NAAQS Serious area plan for the SJV. In particular, the State describes the technical bases for the selection of 2013 for the modeling emissions inventory, explaining that 2013 was conducive to PM

2.5

formation in the SJV; the important DISCOVER-AQ field study measured two significant pollution episodes in the SJV in January to February 2013; and the 2013 design values (across monitoring sites) were relatively high in comparison to other recent years,

making it a conservative choice for future air quality projections for RFP and attainment of the 2012 annual PM

2.5

NAAQS. We agree that these points make 2013 both a conservative year for modeling future air quality and one that aligns the comprehensive, accurate, and recent emissions inventory at the time the State developed and submitted the 2018 PM

2.5

Plan with empirical data from the DISCOVER-AQ field study.

EPA design value workbook dated May 24, 2021, “pm25_designvalues_2018_2020_final_05_24_21.xlsx,” worksheets “Table3a.”

The EPA's approval of the State's demonstration that it was impracticable to attain the 2012 annual PM

2.5

NAAQS by 2021 and reclassification of the SJV to Serious for the 2012 annual PM

2.5

NAAQS was based foremost on the State's modeled demonstration.

While we also considered the 2018-2020 design values (across monitoring sites) as part of our evaluation, such ambient air quality data was not available in 2017-2018 when CARB and the District were developing the 2018 PM

2.5

Plan.

86 FR 67343, 67345. See also, 86 FR 49100, 49117-49118 (proposed rule on State's Moderate area plan).

Therefore, the EPA proposes to find the State's justification for selecting 2013 for the base year emissions inventory to be technically appropriate, consistent with 40 CFR 51.1008(b)(1). Furthermore, the 2013 base year represents actual annual average emissions of all sources within the nonattainment area. Direct PM

2.5

and PM

2.5

precursors are included in the inventories, and filterable and condensable direct PM

2.5

emissions are identified separately.

With respect to future year baseline projections, we have reviewed the growth and control factors estimated by the State and propose to find them acceptable and thus conclude that the future baseline emissions projections in the 2018 PM

2.5

Plan reflect appropriate calculation methods and the latest planning assumptions at the time the State and District were developing the Plan and its emissions inventory. Also, as a general matter, the EPA will approve a SIP submission that takes emissions reduction credit for a control measure only where the EPA has approved the measure as part of the SIP. Thus, for example, to take credit for the emissions reductions from newly adopted or amended District rules for stationary and area sources, the related rules must be approved by the EPA into the SIP.

In our rulemaking on the State's attainment plan for the 2006 24-hour PM

2.5

NAAQS in the SJV, we reviewed the baseline measures identified as 2018 PM

2.5

Plan baseline controls to ensure that the measures that are relied upon in the plan are submitted and approved as part of the California SIP.

We reaffirm that the stationary and area source baseline measures in the 2018 PM

2.5

Plan are approved into the SIP and support the emissions reductions for future years in the SJV, with two exceptions discussed in section IV.F.3.a of the proposed rule that would not materially affect the attainment demonstration in the Plan. With respect to mobile sources, the EPA has acted in recent years to approve CARB mobile source regulations into the state-wide portion of the California SIP.

We therefore propose to find that the future year baseline projections in the 2018 PM

2.5

Plan are properly supported by SIP-approved stationary, area, and mobile source measures.

EPA Region IX, “Technical Support Document, General Evaluation, San Joaquin Valley PM

2.5

Plan for the 2006 PM

2.5

NAAQS,” February 2020 (“EPA's General Evaluation TSD”). Table V-A of EPA's General Evaluation TSD shows District rules with post-2013 compliance dates that are reflected in the future year baseline inventories of the 2018 PM

2.5

Plan, along with information on the EPA's approval of these rules.

See,

e.g.,

81 FR 39424 (June 16, 2016), 82 FR 14447 (March 21, 2017), and 83 FR 23232 (May 18, 2018).

The baseline emissions projections in the 2018 PM

2.5

Plan assume implementation of CARB's zero emissions vehicle (ZEV) sales mandate and greenhouse gas (GHG) standards, based on the EMFAC2014 model that was the current EPA-approved model available at the time of the SIP's development and the assumptions that were available at that time. On September 27, 2019, the U.S. Department of Transportation and the EPA (the Agencies) issued the joint action known as the “Safer Affordable Fuel-Efficient (SAFE) Vehicles Rule Part One: One National Program” (“SAFE I”) that, among other things, withdrew the EPA's 2013 waiver of preemption of CARB's ZEV sales mandate and vehicle GHG standards. 84 FR 51310 (September 27, 2019). See also proposed SAFE rule at 83 FR 42986 (August 24, 2018). On April 30, 2020 (85 FR 24174), the Agencies issued a notice of final rulemaking for the “The Safer Affordable Fuel-Efficient (SAFE) Vehicles Rule for Model Years 2021-2026 Passenger Cars and Light Trucks” (“SAFE II”), establishing the federal fuel economy and GHG vehicle emissions standards based on the

August 2018 SAFE proposal. The effect of both SAFE final rules (SAFE I and SAFE II) on the on-road vehicle mix in the SJV nonattainment area and on the resulting vehicular emissions is expected to be minimal during the timeframe addressed in this SIP revision. Therefore, we anticipate the SAFE final rules would not materially change the demonstration of attainment of the 2012 annual PM

2.5

NAAQS in the SJV by the Serious area attainment date of December 31, 2025.

For these reasons, we are proposing to approve the 2013 base year emissions inventory in the 2018 PM

2.5

Plan as meeting the requirements of CAA section 172(c)(3) and 40 CFR 51.1008. We are also proposing to find that the future year baseline inventories in the 2018 PM

2.5

Plan satisfy the requirements of 40 CFR 51.1008(b)(2) and 51.1012(a)(2) and provide an adequate basis for the control measure, attainment, and RFP demonstrations for the 2012 annual PM

2.5

NAAQS in the 2018 PM

2.5

Plan.

B. PM

2.5

Precursors

Requirements for Control of PM

2.5

Precursors

The provisions of subpart 4 of part D, title I of the CAA do not define the term “precursor” for purposes of PM

2.5

, nor do they explicitly require the control of any specifically identified PM precursor. The statutory definition of “air pollutant” in CAA section 302(g), however, provides that the term “includes any precursors to the formation of any air pollutant, to the extent the Administrator has identified such precursor or precursors for the particular purpose for which the term `air pollutant' is used.” The EPA has identified NO

, SO

, VOC, and ammonia as precursors to the formation of PM

2.5

Accordingly, the attainment plan requirements of subpart 4 apply to emissions of all four precursor pollutants and direct PM

2.5

from all types of stationary, area, and mobile sources, except as otherwise provided in the Act (

e.g.,

in CAA section 189(e)).

81 FR 58010, 58018.

Section 189(e) of the Act requires that the control requirements for major stationary sources of direct PM

(which includes PM

2.5

) also apply to major stationary sources of PM

precursors, except where the Administrator determines that such sources do not contribute significantly to PM

levels that exceed the standard in the area. Section 189(e) contains the only express exception to the control requirements under subpart 4 (

e.g.,

requirements for reasonably available control measures (RACM), reasonably available control technology (RACT), BACM, BACT, most stringent measures (MSM), and nonattainment NSR). Although section 189(e) explicitly addresses only major stationary sources, the EPA interprets the Act as authorizing it also to determine, under appropriate circumstances, that regulation of specific PM

2.5

precursors from other source categories in a given nonattainment area is not necessary. For example, under the EPA's longstanding interpretation of the control requirements that apply to stationary and mobile sources of PM

precursors in the nonattainment area under CAA section 172(c)(1) and subpart 4,

a state may demonstrate in a SIP submission that control of a certain precursor pollutant is not necessary in light of its insignificant contribution to ambient PM

levels in the nonattainment area.

General Preamble, 13539-13542.

Courts have upheld this approach to the requirements of subpart 4 for PM

. See,

e.g., Assoc. of Irritated Residents

EPA, et al.,

423 F.3d 989 (9th Cir. 2005).

Under the PM

2.5

SIP Requirements Rule, a state may elect to submit to the EPA a “comprehensive precursor demonstration” for a specific nonattainment area to show that emissions of a particular precursor from all existing sources located in the nonattainment area do not contribute significantly to PM

2.5

levels that exceed the standard in the area.

If the EPA determines that the contribution of the precursor to PM

2.5

levels in the area is not significant and approves the demonstration, the state is not required to control emissions of the relevant precursor from existing sources in the attainment plan.

40 CFR 51.1006(a)(1).

Id.

In addition, in May 2019, the EPA issued the “PM

2.5

Precursor Demonstration Guidance” (“PM

2.5

Precursor Guidance”), which provides recommendations to states for analyzing nonattainment area PM

2.5

emissions and developing such optional precursor demonstrations, consistent with the PM

2.5

SIP Requirements Rule.

The EPA developed recommended contribution thresholds to help assess whether a precursor significantly contributes to PM

2.5

levels above the NAAQS. The thresholds are based on the size of PM

2.5

differences that are distinguishable statistically in monitored data. If the chemical component of PM

2.5

ambient concentrations corresponding to emissions of a precursor (

e.g.,

the concentration of sulfate, which corresponds to SO

emissions) is below the threshold, that is evidence that the precursor does not significantly contribute. If the precursor fails this concentration-based test, the State can use a sensitivity-based test, in which the modeled sensitivity or response of ambient PM

2.5

concentrations to changes in emissions of the precursor is estimated and then compared to the threshold. In addition to comparing the concentration or modeled response to the threshold, the State can consider other information in assessing whether the precursor significantly contributes. The EPA's recommended annual average contribution threshold for the annual PM

2.5

NAAQS is 0.2 μg/m

“PM

2.5

Precursor Demonstration Guidance,” EPA-454/R-19-004, May 2019, including Memo dated May 30, 2019, from Scott Mathias, Acting Director, Air Quality Policy Division and Richard Wayland, Director, Air Quality Assessment Division, Office of Air Quality Planning and Standards (OAQPS), EPA to Regional Air Division Directors, Regions 1-10, EPA. The PM

2.5

Precursor Guidance builds upon the draft version of the guidance, released on November 17, 2016 (“Draft PM

2.5

Precursor Guidance”), which CARB referenced in developing its precursor demonstration in the SJV PM

2.5

Plan. “PM

2.5

Precursor Demonstration Guidance, Draft for Public Review and Comments,” EPA-454/P-16-001, November 17, 2016, including Memo dated November 17, 2016, from Stephen D. Page, Director, OAQPS, EPA to Regional Air Division Directors, Regions 1-10, EPA.

2.5

Precursor Guidance, 17.

We are evaluating the 2018 PM

2.5

Plan with respect to the Serious area attainment plan requirements in accordance with the presumption embodied within subpart 4 that the State must address all PM

2.5

precursors in its evaluation of potential control measures, unless the State adequately demonstrates that emissions of a particular precursor or precursors do not contribute significantly to ambient PM

2.5

levels that exceed the PM

2.5

NAAQS in the nonattainment area. In reviewing any determination by the State to exclude a PM

2.5

precursor from the required evaluation of potential control measures, we consider both the magnitude of the precursor's contribution to ambient PM

2.5

concentrations in the nonattainment area and the sensitivity of ambient PM

2.5

concentrations in the area to reductions in emissions of that precursor in accordance with the PM

2.5

Precursor Guidance.

Summary of State's Submission

The State's precursor demonstration and conclusions are found in Chapter 7 (“Demonstration of Federal Requirements for 2012 PM

2.5

Standard”) and Appendix G (“Precursor Demonstration”) of the 2018 PM

2.5

Plan. CARB also provides clarifying information on its precursor assessment, including an Attachment A to its letter transmitting the 2018 PM

2.5

Plan to the

EPA

and further clarifications in five email transmittals.

Letter dated May 9, 2019, from Richard W. Corey, Executive Officer, CARB, to Michael Stoker, Regional Administrator, EPA Region IX, Attachment A (“Clarifying information for the San Joaquin Valley 2018 Plan regarding model sensitivity related to ammonia and ammonia controls”).

Email dated June 20, 2019, “RE: SJV model disbenefit from SO

reduction,” from Jeremy Avise, CARB, to Scott Bohning, EPA Region IX, with attachment (“CARB's June 2019 Precursor Clarification”); email dated September 19, 2019, “FW: SJV species responses,” from Jeremy Avise, CARB, to Scott Bohning, EPA Region IX, with attachments (“CARB's September 2019 Precursor Clarification”); email dated October 18, 2019, from Laura Carr, CARB, to Scott Bohning, Jeanhee Hong, and Rory Mays, EPA Region IX, with attachment “Clarifying Information on Ammonia” (“CARB's October 2019 Precursor Clarification”); email dated April 19, 2021, from Laura Carr, CARB, to Rory Mays, EPA Region IX, Subject: “Ammonia update,” with attachment “Update on Ammonia in the San Joaquin Valley” (“CARB's April 19, 2021 Precursor Clarification”); and email dated April 26, 2021, from Laura Carr, CARB, to Scott Bohning, EPA Region IX, Subject: “RE: Ammonia update,” with attachment “Ammonia in San Joaquin Valley” (“CARB's April 26, 2021, Precursor Clarification”).

The State estimates that anthropogenic emissions of NO

, ammonia, SO

, and VOC will decrease by 64 percent (%), 1%, 6%, and 9%, respectively, between 2013 and 2025.

The 2018 PM

2.5

Plan provides both concentration-based and sensitivity-based analyses of precursor contributions to ambient PM

2.5

concentrations in the SJV. Based on these analyses, the State concludes that emissions of NO

(as well as direct PM

2.5

) contribute significantly to ambient PM

2.5

levels that exceed the PM

2.5

NAAQS in the SJV but ammonia, SO

, and VOC do not contribute significantly to such exceedances.

2018 PM

2.5

Plan, Ch. 7, 7-5 and Table 7-2. We also note that a copy of the contents of the 2018 PM

2.5

Plan, App. G appears in the CARB Staff Report, App. C4 (“Precursor Demonstrations for Ammonia, SO

, and ROG”).

We summarize the State's analyses and conclusions for ammonia, SO

, and VOC in the following paragraphs. For a more detailed summary of the precursor demonstration in the Plan, please refer to two EPA technical support documents (TSDs): The first covers all the precursors and the second one specifically addresses ammonia. The first TSD is the EPA's “Technical Support Document, EPA Evaluation of PM

2.5

Precursor Demonstration, San Joaquin Valley PM

2.5

Plan for the 2006 PM

2.5

NAAQS,” February 2020 (“EPA's PM

2.5

Precursor TSD”), which provides the EPA's summary of the State's precursor analyses for all four PM

2.5

precursors. Most of our analysis in the EPA's PM

2.5

Precursor TSD is applicable to the portion of the Plan pertaining to the Serious area plan for the 2012 annual PM

2.5

NAAQS. For example, the State's precursor demonstration used 2015 annual average concentration data for its concentration-based analysis, examined both 24-hour and annual average sensitivities of ambient PM

2.5

concentrations to reductions in each precursor in 2013, 2020, and 2024, and presented information on research studies and emission trends that are relevant for assessing the sensitivity of both 24-hour average and annual average ambient PM

2.5

concentrations to emission reductions of each PM

2.5

precursor. Our evaluation of such factors, as described in the EPA's PM

2.5

Precursor TSD, is similarly applicable for the 2012 annual PM

2.5

NAAQS.

With respect to ammonia emission reductions, the EPA's PM

2.5

Precursor TSD summarizes the State's analysis of 24-hour average sensitivity of ambient PM

2.5

concentrations across monitoring sites and years (see Table 2 of the EPA's PM

2.5

Precursor TSD). The EPA's second TSD, “Technical Support Document, EPA Evaluation of Ammonia Precursor Demonstration, San Joaquin Valley Moderate Area PM

2.5

Plan for the 2012 PM

2.5

NAAQS,” August 2021 (“EPA's Ammonia Precursor TSD”), summarizes the annual average sensitivity of ambient PM

2.5

concentrations to ammonia emission reductions (see Table 2 of the EPA's Ammonia Precursor TSD) and provides further summary and context with respect to the State's ammonia precursor demonstration for the 2012 annual PM

2.5

NAAQS.

For ammonia, SO

, and VOC, CARB assesses the 2015 annual average concentration of each precursor in ambient PM

2.5

at Bakersfield, for which the necessary speciated PM

2.5

data was available and where the highest PM

2.5

design values have been recorded in most years, and compares those concentrations to the recommended annual average contribution threshold of 0.2 μg/m

CARB concludes that the 2015 annual average contributions of ammonia, SO

, and VOC are 5.2 μg/m

, 1.6 μg/m

and 6.2 μg/m

, respectively.

2018 PM

2.5

Plan, App. G, 3. The 2018 PM

2.5

Plan presents a graphical representation of annual average ambient PM

2.5

components (

i.e.,

crustal particulate matter, elemental carbon, organic matter, ammonium sulfate, and ammonium nitrate) for 2011-2013 for Bakersfield, Fresno, and Modesto. 2018 PM

2.5

Plan, Ch. 3, 3-3 to 3-4.

For ammonia, SO

, and VOC, the State modeled the sensitivity of ambient PM

2.5

to 30% and 70% reductions in anthropogenic emissions of each precursor pollutant for modeled years 2013, 2020, and 2024. The year 2013 is the 2018 PM

2.5

Plan's base year; 2020 is the modeled attainment year for the 1997 PM

2.5

NAAQS; and 2024 is the modeled attainment year for the 2006 24-hour PM

2.5

NAAQS. For the 2012 annual PM

2.5

NAAQS, the modeled attainment year is 2025, but the State did not conduct precursor sensitivity modeling for that additional year. Instead the State assumed that 2024 and 2025 would have very similar results;

and results for 2024 were used as a proxy for those of 2025. Emissions totals for those two years are within 0.2% of each other for all pollutants, except that NO

emissions are 3% lower in 2025.

Depending on the analysis year and percentage precursor emission reduction, the sensitivity of ambient PM

2.5

to reductions in annual average precursor emissions ranges from 0.08 μg/m

to 2.30 μg/m

for ammonia; from -0.05 μg/m

to 0.15 μg/m

for SO

; and from -0.50 μg/m

to 0.40 μg/m

for VOC.

Id. at Ch. 7, 7-7, and App. G, 10.

2018 PM

2.5

Plan, App. B. As discussed below, the lower NO

emissions in 2025 compared to 2024 mean that the PM

2.5

response to ammonia reductions would be lower than those stated in the Plan's precursor demonstration; using 2024 results is more conservative than using 2025 results.

Id. at App. G, tables 2 through 7 for ammonia, tables 8 and 9 for SO

, and tables 10 through 15 for VOC.

For ammonia, the modeled sensitivity of ambient PM

2.5

levels to a 30% or 70% emission reduction exceeds 0.2 μg/m

in certain years at specific monitoring sites. As discussed in section IV.B.3.a of this proposed rule, for the 30% reduction results for 2024, upon which the State primarily relied, 2 out of 15 monitoring sites have responses above the threshold and the ambient PM

2.5

response declines substantially from 2020 to 2024, with the decline being generally larger for the sites with the highest projected PM

2.5

levels. In contrast, for SO

and VOC, the modeled sensitivity of ambient PM

2.5

levels to a 30% or 70% emission reduction in either precursor is below 0.2 μg/m

in all model scenarios except one, including a disbenefit (

i.e.,

ambient PM

2.5

levels increase when precursor emissions are reduced) at some monitoring sites for both precursors. For 2013, the State's modeling shows an ambient PM

2.5

change greater than 0.2 μg/m

at 7 out of 15 monitoring sites in response to a 70% VOC emission reduction. According to the State, however, such sensitivity results do not reflect the current atmospheric chemistry in the SJV given the projected emission reductions from 2013 to 2024 for all four PM

2.5

precursors, especially for VOC and NO

, as further described in this proposed rule.

The State supplemented the sensitivity analysis, particularly for ammonia, with consideration of additional information such as emission trends, the appropriateness of future year versus base year sensitivity, available emission controls, and the severity of nonattainment.

These factors were identified in the then-available Draft PM

2.5

Precursor Guidance, as well as in the final PM

2.5

Precursor Guidance, as factors that may be relevant to a sensitivity-based contribution analysis.

Id. at App. G, 5.

2.5

Precursor Guidance, 18-19 (consideration of additional information), 31 (available emission controls), and 35-36 (appropriateness of future year versus base year sensitivity).

The State notes that a 53% reduction in (baseline) NO

emissions is projected to occur between 2013 and 2024,

so the conditions in the early years will not persist and the future year is more representative of the Valley's ambient conditions than earlier years. The 2018 PM

2.5

Plan's precursor demonstration also presents a review of District agricultural rules that control VOC emissions and also provide ammonia co-benefits. The State concludes that a 30% reduction is a reasonable upper bound on the ammonia reductions to model. Finally, the 2018 PM

2.5

Plan's precursor demonstration presents extensive support for the State's conclusion regarding an ambient excess of ammonia relative to NO

i.e.,

that particulate ammonium nitrate formation is NO

-limited, and will become increasingly NO

-limited as NO

reductions increase into the future.

2018 PM

2.5

Plan, App. G, 8.

EPA Evaluation and Proposed Action

The EPA has evaluated the State's precursor demonstration in the 2018 PM

2.5

Plan, as well as other relevant information available to the EPA, consistent with the PM

2.5

SIP Requirements Rule and the recommendations in the PM

2.5

Precursor Guidance. Based on this evaluation, the EPA agrees with the State's conclusion that NO

emissions contribute significantly to ambient PM

2.5

levels that exceed the 2012 annual PM

2.5

NAAQS in the SJV and that NO

emission sources, therefore, remain subject to control requirements under subparts 1 and 4 of part D, title I of the Act. Additionally, for the reasons provided in the following paragraphs, the EPA proposes to approve the State's comprehensive precursor demonstrations for ammonia, SO

, and VOC based on a conclusion that emissions of these precursor pollutants do not contribute significantly to ambient PM

2.5

levels that exceed the 2012 annual PM

2.5

NAAQS in the SJV.

The State based its analyses on the latest available data and studies concerning ambient PM

2.5

formation in the SJV from precursor emissions. For the required concentration-based analysis, the State assessed the absolute annual average contribution of each precursor to ambient PM

2.5

(

i.e.,

in 2015). Given that the absolute concentrations in 2015 were above the EPA's recommended contribution thresholds for both the 24-hour and annual average PM

2.5

NAAQS, the State proceeded to a sensitivity-based analysis, consistent with the PM

2.5

SIP Requirements Rule.

For the sensitivity-based analysis, the State performed its analyses based on the EPA's recommended approach—

i.e.,

for each modeled year and level of precursor emissions reduction (in percentages), the State estimated the ambient PM

2.5

response using the procedure recommended in the PM

2.5

Precursor Guidance, and compared the result to the EPA's recommended contribution threshold. In particular, the State considered the EPA's recommended range of emission reductions (30% to 70%) for the 2013 base year, 2020 (an interim year), and the 2024 future year, and quantified the estimated response of ambient PM

2.5

concentrations to precursor emission changes in the SJV.

The State's emissions projections in the 2018 PM

2.5

Plan show that baseline emissions of each of these precursors will decrease from the 2013 base year to both 2021 and 2025. These decreases are included in the State's modeled projections of ambient PM

2.5

levels in the SJV for purposes of demonstrating attainment and RFP. The State's sensitivity analyses are consistent with these projections, in accordance with the EPA's recommendations in the PM

2.5

Precursor Guidance.

2.5

Precursor Guidance, 35.

In the subsections that follow, we summarize our evaluation of the State's precursor demonstrations for ammonia, SO

, and VOC for purposes of the 2012 annual PM

2.5

NAAQS in the SJV.

(a) Ammonia Precursor Demonstration

In the 2018 PM

2.5

Plan, CARB estimates the ambient PM

2.5

response to both a 30% and a 70% emissions reduction in 2013, 2020, and 2024. We have evaluated CARB's sensitivity-based contribution analyses for 2013, 2020, and 2024 (in the 2018 PM

2.5

Plan) and CARB's determination that 2024 results are representative of conditions in the SJV for purposes of a sensitivity-based analysis, as discussed in the following paragraphs. The EPA's PM

2.5

Precursor Guidance explicitly provides for consideration of a future year, such as the attainment year.

We consider it appropriate for the State to take into account additional information as part of its evaluation of whether the ammonia contribution is significant and to rely on the responses to the 30% modeled ammonia emissions reduction in its precursor demonstration for ammonia. The State primarily relied on the 30% reduction results after concluding that 30% was a reasonable upper bound on potential ammonia reductions, based on past research on ammonia emissions and potential control options for agricultural sources. The EPA agrees that this is a reasonable upper bound on ammonia emissions reductions to use in the precursor demonstration, as discussed in EPA's approval of the precursor demonstration for the 2006 24-hour PM

2.5

NAAQS.

We provide a detailed evaluation of the State's precursor demonstration for ammonia emissions in the EPA's Ammonia Precursor TSD.

Id.

85 FR 17382 (March 27, 2020), 17395; EPA's PM

2.5

Precursor TSD, 13.

The precursor demonstration in the 2018 PM

2.5

Plan indicates that the ambient response to a 30% ammonia emission reduction would exceed the EPA's recommended contribution threshold of 0.2 μg/m

for 14 out of 15 monitoring sites in the 2013 analysis year, and at 9 out of 15 for the 2020 analysis year. For the 2024 analysis year, 2 of the 15 sites would exceed the contribution threshold, Madera and Hanford. In absolute terms, the ambient PM

2.5

response declines from 0.24 μg/m

in 2020 to 0.12 μg/m

in 2024 at Bakersfield-Planz, the highest concentration site. The Madera and Hanford responses decline, respectively, from 0.36 to 0.21 μg/m

, and from 0.42 to 0.26 μg/m

. The average response over all monitoring sites declines from 0.23 μg/m

to 0.14 μg/m

, with the decline being generally larger for the sites with the highest projected PM

2.5

levels.

While the Madera and Hanford responses to ammonia reductions are above the contribution threshold, additional information about these locations leads the EPA to give these responses lower weight in the overall assessment of whether ammonia contributes significantly to PM

2.5

levels. The State notes that the 2013 base year Madera monitored concentrations are

biased high,

which would lead to model estimates of the response to ammonia reductions that are biased high (because for model projections, relative responses of the model to emissions changes are applied to monitored concentrations). While the State did not discuss the evidence for this in detail in its 2018 PM

2.5

Plan, it is consistent with an analysis of Madera measured concentrations that the State provided in a prior PM

2.5

plan for the SJV.

The EPA has previously discussed that the Madera data for the limited period of 2011 to 2013 are not representative for purposes of an attainment demonstration.

2018 PM

2.5

Plan, App. G, 14.

“Assessment of the Representativeness of 2011 PM

2.5

Beta Attenuation Monitor Data from Madera,” in “Staff Report, ARB Review of San Joaquin Valley PM

2.5

State Implementation Plan,” adopted by CARB on May 21, 2015, App. A, “Weight of Evidence Analysis.”

81 FR 6936, 6971 (February 9, 2016). The conclusion that 2011-2013 Madera data was biased high was based on it not fitting the north-south concentration gradient historically seen in relations to other monitors, a comparison to data from a second monitor at the same site, and the return to the historic pattern after adjustments were made to instrument operation after checking its zero point. The data is considered valid in the EPA's Air Quality System (AQS) for purposes of assessing whether the NAAQS is met. However, the EPA considered it to be anomalously high for that period, and not representative for use in modeling. Adjusted substituted data from nearby monitors had concentrations about 10% lower, and were accepted by the EPA for the demonstration of attainment of the 1997 annual PM

2.5

NAAQS.

For the 2018 PM

2.5

Plan precursor demonstration, Madera's ambient PM

2.5

response in 2024 to a 30% ammonia emissions reduction was 0.21 μg/m

, just 5% above EPA's recommended contribution threshold of 0.2 μg/m

. Because the 2024 modeling starting point was a base design value using monitored concentrations from 2010-2014, if more typical Madera concentrations were used, it is likely that the 2024 Madera response to ammonia reductions would be below the contribution threshold. Moreover, given the NO

emission reductions that are projected to continue from 2024 to 2025, the EPA expects that PM

2.5

sensitivity to ammonia reductions would decrease from the 0.21 μg/m

unadjusted value in 2024 to a lower value in 2025, likely decreasing even the unadjusted, biased-high value to below the threshold.

There is also information suggesting that the Hanford response to ammonia reductions may be lower than indicated in the State's 2018 PM

2.5

Plan precursor demonstration. An independent study using aircraft and surface data from the winter 2013 DISCOVER-AQ

campaign, a key period in the 2018 PM

2.5

Plan's 2013 base year, found that the Community Multiscale Air Quality (CMAQ) model underestimated ammonia at Hanford by roughly a factor of five; Hanford is just outside a region with high ammonia emissions in the model (western Tulare County).

If the model's ammonia concentrations were higher to better match observations, then there would be relatively more ammonia per NO

; ammonia then would be less of a limiting factor for particulate ammonium nitrate formation and the model response to ammonia reductions would be lower. This phenomenon is described more fully below.

NASA, “Deriving Information on Surface conditions from COlumn and VERtically Resolved Observations Relevant to Air Quality,” described at

https://www.nasa.gov/mission_pages/discover-aq/index.html.

Kelly, J.T.

et al.

2018, “Modeling NH

over the San Joaquin Valley during the 2013 DISCOVER-AQ campaign,” Journal of Geophysical Research: Atmospheres, 123, 4727-4745,

https://doi.org/10.1029/2018JD028290

at 4733. The paper notes that, despite the ammonia underestimation, model performance was good for particulate ammonium nitrate and the ammonium nitrate was not sensitive to the ammonia underestimate since its formation was NO

-limited.

The 2018 PM

2.5

Plan did not include an evaluation of model performance for ammonia per se (just for particulate ammonium), but in supplemental transmittals

CARB described the results of two analyses confirming the likely underestimation of ammonia. CARB compared CMAQ model predictions of ammonia with the 2013 DISCOVER-AQ aircraft measurements and found that ammonia was underpredicted, and noted that this would result in the PM

2.5

response to ammonia reductions being overpredicted. CARB also compared 2017 satellite measurements of ammonia with CMAQ model predictions and found that modeled ammonia concentrations were half of the magnitude of the satellite observations at some locations, and the modeled average in the SJV was about 25% less than observed. CARB concluded that the model tends to overpredict the sensitivity of ammonium nitrate formation to ammonia emission reductions. CARB also speculated that the underprediction could be partly be explained by the underestimation of ammonia emissions using current methodologies.

If modeled ammonia concentrations were closer to observations,

e.g.,

via increased emissions in the model, then the modeled response to ammonia precursor reductions would be lower than shown in the 2018 PM

2.5

Plan's precursor demonstration. An increase in modeled ambient ammonia (such as via a larger emissions estimate) would also make the model response more consistent with the evidence from the ambient measurement studies that are discussed next.

CARB's April 19, 2021, Precursor Clarification and CARB's April 26, 2021, Precursor Clarification.

As discussed in EPA's Ammonia Precursor TSD, there is evidence that ammonia emisions are underestimated, based on comparsons between satellite measurements and what would be expected from emissions inventories.

As additional information for assessing the contribution of ammonia to PM

2.5

, the State discussed evidence from multiple ambient measurement studies.

The studies suggest a very low ambient sensitivity to ammonia, based on measured excess ammonia relative to NO

, the abundance of particulate nitrate relative to gaseous NO

, and the large abundance of ammonia relative to nitric acid. The studies all conclude that there is a large amount of ammonia left over after reacting with NO

, so that ammonia emission reductions would be expected mainly to reduce the amount of ammonia excess, rather than to reduce the particulate amonium nitrate. These ambient studies provide strong evidence independent of the modeling that PM

2.5

would respond only weakly to ammonia emissions reductions.

2018 PM

2.5

Plan, 6-7, and App. G, G-9 to G-10; the CARB 2018 Staff Report, App. C, 12-15; and Submittal Letter, Attachment A. These studies are also discussed in the EPA's PM

2.5

Precursor TSD.

Another consideration is that the PM

2.5

benefit of ammonia emission reductions is projected to decline steeply over time. In selecting the analysis year for a precursor demonstration, we believe it is appropriate to consider changes in atmospheric chemistry that may occur between the base or current year and the attainment year because the changes may ultimately affect the nonattainment area's progress toward expeditious attainment. The PM

2.5

Precursor Guidance explicitly states that a future year may be used, and that there are a multitude of considerations in choosing the analysis year.

The “anticipated growth or loss of sources . . . or trends in ambient speciation data and precursor emissions”

are among the “facts and circumstances of the area”

100

to consider in determining the significance of a precursor. The Guidance states that a future year could be more appropriate if it better represents the period that sources will operate in. As discussed in more detail below, the 2024 model results better

represent the period that ammonia sources will operate in, because of the steep decline in NO

emissions projected to occur by 2024 and 2025. We consider it reasonable for the State to focus on the ambient PM

2.5

response to ammonia emission reductions in 2024, rather than an earlier year, as the modeled response in 2024 in the SJV better reflects the potential benefit of ammonia control measures for purposes of expeditious attainment of the 2012 annual PM

2.5

NAAQS.

2.5

Precursor Guidance, 35.

Id. at 18.

100

2.5

SIP Requirements Rule, 40 CFR 51.1006(a)(1)(ii).

The State's precursor demonstration in the 2018 PM

2.5

Plan shows that ambient sensitivity to ammonia emission reductions in the SJV declines steeply over time. Between 2020 and 2024, the modeled response to a 30% ammonia emission reduction declines by 50% at the Bakersfield-Planz monitoring site, which has the highest projected PM

2.5

level, and by 37% averaged over all monitoring sites.

101

As noted above, in absolute terms, the ambient PM

2.5

response declines from 0.24 μg/m

in 2020 to 0.12 μg/m

in 2024 at Bakersfield-Planz, which has the highest projected PM

2.5

design value, and from 0.23 μg/m

to 0.14 μg/m

as averaged over all monitoring sites, with the decline being generally larger for the sites with the highest projected PM

2.5

levels. Thus, between 2020 and 2024, the number of sites at which modeled sensitivity exceeds the 0.2 μg/m

threshold declines from 9 out of 15 down to 1 or 2 out of 15.

102

As discussed above, ammonia sensitivity declines because of the shifting atmospheric chemistry caused by NO

emissions decreases. NO

emissions are projected to decrease 27% between 2020 and 2024 due to baseline measures (

e.g.,

existing motor vehicle controls). The decreased NO

emissions will make ammonia more abundant relative to NO

, and even less of a limiting factor on PM

2.5

formation. In other words, the model response in the future year 2024 gives a more realistic assessment of the potential effect of ammonia controls than past or current conditions. Between 2024 and 2025, the attainment year, NO

emissions are projected to decrease by an additional 3.5% from 2024 levels,

103

so that the response to ammonia reductions in the attainment year would be lower than the 2024 results reported in the Plan.

101

Extrapolating the 2018 PM

2.5

Plan results to 2025, the percent declines are 55% and 40%, respectively, which are larger still than those for 2024.

102

2018 PM

2.5

Plan, App. G, tables 4 and 5, G-11. As discussed above, the response for the Madera site is likely below the contribution threshold since its monitored concentrations are biased high.

103

Annual average NO

emissions are projected to decrease from 148.9 tpd in 2024 to 143.7 tpd in 2025. 2018 PM

2.5

Plan, App. B, Table B-2.

Finally, based on the 2024 sensitivity results,

104

if ammonia emissions were reduced by 30%, the area's projected 12.0 μg/m

design value, occurring at the Bakersfield-Planz monitoring site, would be reduced by 0.12 μg/m

, which would not be considered significant (it is below the EPA's recommended threshold of 0.2 μg/m

104

2018 PM

2.5

Plan, App. G, tables 5 and 7, 11-12. The response to 2025 ammonia reductions would be lower than the values stated in the text, due to the effect of declining NO

emissions.

In sum, we conclude that the State quantified the sensitivity of ambient PM

2.5

levels to reductions in ammonia emissions using appropriate modeling technique; the modeled response to ammonia reductions is likely lower than reported; and the State's choice of 2024 and 2025 as the reference points for purposes of evaluating the sensitivity of ambient PM

2.5

levels to ammonia emission reductions is well-supported. Based on all of these considerations, the EPA proposes to approve the State's demonstration that ammonia emissions do not contribute significantly to ambient PM

2.5

levels that exceed the 2012 annual PM

2.5

NAAQS in the SJV.

(b) SO

Precursor Demonstration

In the 2018 PM

2.5

Plan, CARB estimated the 2013 ambient PM

2.5

response to a 30% SO

emission reduction to range from −0.01 μg/m

to 0.07 μg/m

and estimated the ambient PM

2.5

response to a 70% SO

emission reduction to range from −0.05 μg/m

to 0.15 μg/m

105

The State also provides an emissions trend chart that shows SO

emissions to be steady at approximately 8 tpd from 2013 through 2024. Given that the relative levels of estimated SO

and ammonia emissions over that timeframe remain similar, the State concludes that the 2013 sensitivities are also representative of future years.

106

The State also provides the ambient PM

2.5

responses in 2013, 2020, and 2024 to 30% and 70% reductions in SO

emissions, all of which are below the 0.2 μg/m

contribution threshold.

107

105

Id. at App. G, 15-16, tables 8 and 9.

106

2018 PM

2.5

Plan, App. G, 15. The State includes modeling of 30% and 70% reductions of SO

only for 2013, finding that the sensitivity of ambient PM

2.5

to such changes were below the EPA's recommended threshold, and that the 2020 and 2024 results would differ little from 2013 due to the similarity of emissions conditions over time. App. G, 17. CARB's September 2019 Precursor Clarification provides the 2020 and 2024 sensitivity results, which are indeed very close to those for 2013.

107

CARB's September 2019 Precursor Clarification.

We note that the 2018 PM

2.5

Plan's sensitivity estimates for 2013 are well below that threshold for both the 30% and 70% emission reduction scenarios and even negative for certain monitoring sites. Given those results and the steady SO

emission levels over 2013 to 2025 (as opposed to increases), the EPA agrees with the State's conclusion that the 2013 modeled sensitivities provide a sufficient basis for the SO

precursor demonstration. The supplemental results provided by the State for 2020 and 2024 support this conclusion.

Therefore, on the basis of these modeled ambient PM

2.5

responses to SO

emission reductions in the SJV, and the facts and circumstances of the area, the EPA proposes to approve the State's demonstration that SO

emissions do not contribute significantly to ambient PM

2.5

levels that exceed the 2012 annual PM

2.5

NAAQS in the SJV.

In the 2018 PM

2.5

Plan, the State found that the ambient PM

2.5

response to VOC emission reductions were generally below the EPA's recommended contribution threshold of 0.2 μg/m

, and predicted an increase in ambient PM

2.5

levels in response to VOC reductions (

i.e.,

a disbenefit) at 2 out of 15 monitoring sites in 2020, and 11 out of 15 sites in 2024. Only for a 70% emission reduction for the 2013 base year did the State predict the ambient PM

2.5

response to be above the threshold at a majority of sites.

108

2018 PM

2.5

Plan, App. G, 18-19, tables 10 and 11.

We note that the 2018 PM

2.5

Plan's sensitivity estimates for 2020 and 2024 are well below that threshold for both the 30% and 70% emission reduction scenarios, and even negative for certain monitoring sites. The State also provides an emissions trend chart that shows VOC emissions are projected to decrease by about 30 tpd, or 9% between 2013 and 2020 as well as between 2013 and 2024, and concludes that 2013 sensitivity results are not representative into the future and that the 2020 and 2024 results are representative.

109

Finally, the State concludes that VOC emissions do not contribute significantly to PM

2.5

levels that exceed the 2012 annual PM

2.5

NAAQS.

109

Id. at App. G, 19-20.

The EPA has evaluated and agrees with the State's determination in the 2018 PM

2.5

Plan that the projected 2024 year is more representative of conditions in the SJV for sensitivity-based analyses and that VOC reductions in 2024 would mostly result in a

disbenefit to ambient PM

2.5

levels, seen at 11 of 15 monitoring sites. The EPA agrees that the 9% VOC emissions decrease from 2013 to 2024 supports reliance on the 2024 modeling results. Furthermore, there is projected to be a large decrease in NO

emissions over this period, as described in section IV.B.2 of this proposed rule, that affects the atmospheric chemistry with respect to ambient PM

2.5

formation from VOC emissions. The 9% VOC emission reductions and the vast majority of NO

emissions reductions are expected to result from baseline measures already in effect. Therefore, we conclude that it is reasonable to rely on future year 2024 modeled responses to VOC reductions. The EPA also concludes that the State provided a reasonable explanation for the VOC reduction disbenefit and evidence that it occurs in the SJV; as discussed in the EPA's PM

2.5

Precursor TSD, VOC reductions led to less peroxyacetyl nitrate formation, and so to greater availability of nitrate to form particulate ammonium nitrate.

110

EPA's PM

2.5

Precursor TSD, 22.

For these reasons, we propose to approve the State's demonstration that VOC emissions do not contribute significantly to ambient PM

2.5

levels that exceed the 2012 annual PM

2.5

NAAQS in the SJV.

C. Air Quality Modeling

1. Requirements for Air Quality Modeling

Section 189(b)(1)(A) of the CAA requires that each Serious area plan include a demonstration (including air quality modeling) that the plan provides for attainment of the PM

2.5

NAAQS by the applicable attainment date. As noted in sections I and II of this proposed rule, the outermost statutory Serious area attainment date for the 2012 annual PM

2.5

NAAQS in the SJV is December 31, 2025.

The PM

2.5

SIP Requirements Rule explains that Serious area plans under CAA section 189(b) must include a demonstration (including air quality modeling) that the control strategy provides for attainment of the PM

2.5

NAAQS as expeditiously as practicable.

111

For purposes of determining the attainment date that is as expeditious as practicable, the state must conduct future year modeling that takes into account emissions growth, known controls (including any controls that were previously determined to be RACM/RACT or BACM/BACT), and any other emissions controls that are needed for expeditious attainment of the NAAQS.

111

40 CFR 51.1011(b)(1); 81 FR 58010, 58087.

The EPA's PM

2.5

modeling guidance

112

(“Modeling Guidance” and “Modeling Guidance Update”) recommends that states use a photochemical model, such as the CMAQ model, to simulate a base case, with meteorological and emissions inputs reflecting a base case year to replicate concentrations monitored in that year. The Modeling Guidance recommends the following procedures for states to use in attainment demonstrations. The model should undergo a performance evaluation to ensure that it satisfactorily reproduces the concentrations monitored in the base case year. The model may then be used to simulate emissions occurring in other years required for an attainment plan, namely the base year (which may differ from the base case year) and future year.

113

The Modeling Guidance recommends that the modeled response to the emission changes between the base and future years be used to calculate relative response factors (RRFs). The modeled RRFs are then applied to the monitored design value in the base year to estimate the projected design value in the future year, which can be compared against the NAAQS. In the recommended procedure, the RRFs are calculated for each chemical species component of PM

2.5

, and for each quarter of the year, to reflect their differing responses to seasonal meteorological conditions and emissions. Because each species is handled separately, before applying an RRF, the base year PM

2.5

design value must first be split into its species components, using available chemical species measurements. The Modeling Guidance provides additional detail on the recommended approach.

114

112

Memorandum dated November 29, 2018, from Richard Wayland, Air Quality Assessment Division, OAQPS, EPA, to Regional Air Division Directors, EPA, Subject: “Modeling Guidance for Demonstrating Air Quality Goals for Ozone, PM

2.5

, and Regional Haze,” (“Modeling Guidance”), and Memorandum dated June 28, 2011, from Tyler Fox, Air Quality Modeling Group, OAQPS, EPA, to Regional Air Program Managers, EPA, Subject: “Update to the 24 Hour PM

2.5

NAAQS Modeled Attainment Test,” (“Modeling Guidance Update”).

113

In this section, we use the terms “base case,” “base year” or “baseline,” and “future year” as described in section 2.3 of the EPA's Modeling Guidance. The “base case” modeling simulates measured concentrations for a given time period, using emissions and meteorology for that same year. The modeling “base year” (which can be the same as the base case year) is the emissions starting point for the plan and for projections to the future year, both of which are modeled for the attainment demonstration. Modeling Guidance, 37-38. Note that CARB sometimes uses “base year” synonymously with “base case” and “reference year” instead of “base year.”

114

Modeling Guidance, section 4.4, “What is the Modeled Attainment Tests for the Annual Average PM

2.5

NAAQS.”

2. Summary of State's Submission

The 2018 PM

2.5

Plan includes a modeled demonstration projecting that the SJV will attain the 2012 annual PM

2.5

NAAQS by December 31, 2025. The Plan's primary discussion of the photochemical modeling appears in Appendix K (“Modeling Attainment Demonstration”) of the 2018 PM

2.5

Plan. The State briefly summarizes the area's air quality problem in Chapter 2.2 (“Air Quality Challenges and Trends”) and summarizes the modeling results in Chapter 7.4 (“Attainment Demonstration and Modeling”) of the 2018 PM

2.5

Plan. The State provides a conceptual model of PM

2.5

formation in the SJV as part of the modeling protocol in Appendix L (“Modeling Protocol”). Appendix J (“Modeling Emission Inventory”) describes emission input preparation procedures. The State presents additional relevant information in Appendix C (“Weight of Evidence Analysis”) of the CARB 2018 Staff Report, which includes ambient trends and other data in support of the demonstration of attainment by 2025.

3. EPA Evaluation and Conclusion

CARB's air quality modeling approach investigated the many interconnected facets of modeling ambient PM

2.5

in the SJV, including model input preparation, model performance evaluation, use of the model output for the numerical NAAQS attainment test, and modeling documentation. Specifically, this required the development and evaluation of a conceptual model, modeling protocol, episode (

i.e.,

base year) selection, modeling domain, CMAQ model selection, initial and boundary condition procedures, meteorological model choice and performance, modeling emissions inventory preparation procedures, model performance, attainment test procedure, and adjustments to baseline air quality for modeling. These analyses are generally consistent with the EPA's recommendations in the Modeling Guidance.

The model performance evaluation in section 5.2 (“CMAQ Model Evaluation”) of Appendix K of the 2018 PM

2.5

Plan included statistical and graphical measures of model performance.

The EPA's evaluation of the modeling for the 2012 annual PM

2.5

NAAQS incorporates the evaluation that the EPA previously did for other NAAQS in the

2018 PM

2.5

Plan. The EPA previously evaluated and approved the modeling conducted for the 2006 24-hour PM

2.5

NAAQS as part of the 2018 PM

2.5

Plan; see the EPA's “Technical Support Document, EPA Evaluation of Air Quality Modeling, San Joaquin Valley PM

2.5

Plan for the 2006 PM

2.5

NAAQS,” February 2020 (“EPA's 2006 NAAQS Modeling TSD”) accompanying that action for details.

115

The conclusions in the EPA's 2006 NAAQS Modeling TSD focused on the 2006 24-hour PM

2.5

NAAQS; in this notice we extend the evaluation with information specific to the 2012 annual PM

2.5

NAAQS.

115

The model performance is discussed further in section J (“Air Quality Model Performance”) of the EPA's 2006 NAAQS Modeling TSD.

Most aspects of the 2018 PM

2.5

Plan modeling and the EPA's evaluation of it are the same for the 24-hour and the annual averaging times, and the EPA has found them adequate. These include the modeling protocol, choice of model, meteorological modeling, modeling emissions inventory, choice of model, modeling domain, and procedures for model performance evaluation. One aspect that differs between the 24-hour and annual averaging times is the specific calculation procedure for estimating a future design value. In the procedure recommended in the Modeling Guidance for both averaging times, the model is used to calculate RRFs, the ratio of modeled future concentrations to base year concentrations, and the RRF is applied to monitored base year concentrations; this is done for each monitor, PM

2.5

species, and calendar quarter. But for the 24-hour averaging time, the recommended procedure uses the highest individual concentration days in each quarter, whereas for the annual average, it uses the average of all days in each quarter. For the current action on the 2018 PM

2.5

Plan, the EPA considers that the State procedures

116

for estimating future design values for the 2012 annual PM

2.5

NAAQS generally followed the EPA's recommendations and are adequate.

116

2018 PM

2.5

Plan, App. K, 18.

Another modeling aspect that can differ between 24-hour and annual average is the focus of the model performance evaluation on the respective averaging times. For the 24-hour average, it is especially important that modeled concentrations on the highest days are comparable to those on the highest monitored days because calculation of the design value for the 24-hour PM

2.5

NAAQS uses the 98th percentile concentrations. For the annual average, peak concentrations continue to be important, but lower concentration days are also important because all days are included in the average. Under- and over-predictions on non-peak days may average out and have little overall effect on the modeled annual concentration, but systematic underprediction on non-peak days could lead to model underprediction of the annual average concentration. This problem of model bias is mitigated by the use of the model in a relative sense as recommended in the Modeling Guidance. In the RRF, model bias “cancels out” to a degree since it would be present in both its numerator (future year) and its denominator (base year). Applying the RRF to monitored base year concentration in this way anchors the final model prediction to real-world concentrations. Further, the Modeling Guidance recommends that RRFs be calculated on a quarterly basis, to better account for emissions sources and atmospheric chemistry that differ between the seasons.

The 2018 PM

2.5

Plan did not include a separate model performance evaluation for the 24-hour and annual PM

2.5

averaging times; the State used statistical and graphical analyses applicable to both. The EPA evaluated the modeling for the 2012 annual PM

2.5

NAAQS using that same information, much of which has already been discussed in the EPA's 2006 NAAQS Modeling TSD. For the most part, in the EPA's 2006 NAAQS Modeling TSD, the EPA did not distinguish between the two averaging times either, but drew conclusions for the 24-hour averaging time rather than the annual averaging time. That TSD did note a relatively large negative normalized bias (underprediction) in the ammonium and nitrate performance statistics

117

for the 2nd quarter for monitoring sites in Bakersfield, Fresno, and Visalia; and we add here that the 3rd quarter has similar negative bias. Underprediction of total PM

2.5

in the 2nd and 3rd quarters is also evident in time series plots for most monitoring sites, though by only a small amount for several monitoring sites.

118

The RRF procedure removes much of this bias, so the underprediction in the model performance evaluation does not translate into an underpredicted 2025 design value. The EPA's 2006 NAAQS Modeling TSD noted that because those quarters have projected concentrations that are less than half of those in the 1st and 4th, this may have a small influence on annual average concentrations. It has still less influence on the 24-hour average, because peak 24-hour concentrations typically occur in winter,

i.e.,

in the 1st and 4th quarters. For example, the worst quarterly underprediction for nitrate was a for quarter 3, and occurred when quarterly total PM

2.5

concentration was 9.4 μg/m

. By contrast, for quarter 1 nitrate had a small overprediction, and occurred when quarterly total PM

2.5

concentration was 21.1 μg/m

. That is, nitrate predictions have more bias during the quarters with low PM

2.5

concentrations. This is apparent from the Plan's “bugle” plot for the four monitors with speciated data.

119

Large (negative) values of bias in nitrate predictions occur for the lowest quarterly nitrate concentrations. For the higher concentrations that most affect the annual average, nitrate fractional bias has a mixture of positive and negative values. For total PM

2.5

, fractional bias has a similar seasonal pattern to that of nitrate, with underprediction during quarter 2 and quarter 3 when quarterly PM

2.5

concentration values are in the 5-10 μg/m

range, and small bias when quarterly concentrations are in the 20-30 μg/m

range. For the overall annual average, performance is good relative to that seen in other modeling studies with lower values of bias and error for multiple performance statistics for nitrate, as well as for the other PM

2.5

species and total PM

2.5

120

117

Id. at App. K, 48

ff,

tables 20 through 23.

118

Id. at App. K, 131

ff,

Supplemental materials, Figures S.41-S.52.

119

Id. at App. K, 53, Figure 13.

120

Id. at App. K, 54, Figure 14.

The high PM

2.5

concentration days are generally captured by the model, even though some are underpredicted in December at certain monitoring sites such as Fresno. Overall, the modeled site maxima are comparable to the measurements. Also, the frequency of high and low days generally matches observations so the annual as well as the daily model performance is acceptable.

The EPA evaluated, in our rulemaking with respect to the 2006 24-hour PM

2.5

NAAQS in the SJV, the State's choice of model and the extensive discussion in the 2018 PM

2.5

Plan about modeling procedures, tests, and performance analyses.

121

We consider the State's analyses consistent with the EPA's guidance on modeling for PM

2.5

attainment planning purposes. Based on these reviews, we propose to find that the modeling in the 2018 PM

2.5

Plan is adequate for the purposes of supporting

the State's RFP demonstration and the attainment demonstration.

121

For a more detailed summary of the State's air quality modeling in the 2018 PM

2.5

Plan with respect to the 2006 24-hour PM

2.5

NAAQS, rather than the 2012 annual PM

2.5

NAAQS, please refer to the EPA's 2006 NAAQS Modeling TSD.

D. Best Available Control Measures

1. Statutory and Regulatory Requirements

Section 189(b)(1)(B) of the Act requires for any serious PM

2.5

nonattainment area that the state submit provisions to assure that the best available control measures (BACM) for the control of PM

2.5

and PM

2.5

precursors shall be implemented no later than four years after the date the area is reclassified as a Serious area. The EPA has defined BACM in the PM

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 best available control technology (BACT).”

122

40 CFR 51.1000 (definitions). In longstanding guidance, the EPA has similarly defined BACM to mean, “among other things, the maximum degree of emissions reduction achievable for a source or source category, which is determined on a case-by-case basis considering energy, environmental, and economic impacts.” General Preamble Addendum, 42010, 42013.

The EPA generally considers BACM a control level that goes beyond existing RACM-level controls, for example by expanding the use of RACM controls or by requiring preventative measures instead of remediation.

123

Indeed, as implementation of BACM and BACT is required when a Moderate nonattainment area is reclassified as Serious due to its inability to attain the NAAQS through implementation of “reasonable” measures, it is logical that “best” control measures should represent a more stringent and potentially more costly level of control.

124

If RACM and RACT level controls of emissions have been insufficient to reach attainment, the CAA contemplates the implementation of more stringent controls, controls on more sources, or other adjustments to the control strategy necessary to attain the NAAQS in the area.

123

81 FR 58010, 58081 and General Preamble Addendum, 42011, 42013.

124

Id. and General Preamble Addendum, 42009-42010.

Consistent with longstanding guidance provided in the General Preamble Addendum, the preamble to the PM

2.5

SIP Requirements Rule discusses the following steps for determining BACM and BACT:

1. Develop a comprehensive emission 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.

125

81 FR 58010, 58083-58085.

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.

126

40 CFR 51.1010(a)(3) and 81 FR 58010, 58041-58042.

Once these analyses are complete, the state must use this information to develop enforceable control measures and submit them to the EPA for evaluation as SIP provisions to meet the basic requirements of CAA section 110 and any other applicable substantive provisions of the Act. The EPA is using these steps as guidelines in the evaluation of the BACM and BACT measures and related analyses in the SJV PM

2.5

Plan.

2. Summary of State's Submission

As discussed in section IV.A of this proposed rule, Appendix B of the 2018 PM

2.5

Plan contains the planning inventories for direct PM

2.5

and all PM

2.5

precursors (NO

, SO

, VOC, and ammonia) for the SJV nonattainment area together with documentation to support these inventories. Each inventory includes emissions from stationary, area, on-road, and non-road emission sources, and the State specifically identifies the condensable component of direct PM

2.5

for relevant stationary and area source categories. As discussed in section IV.B of this proposed rule concerning precursors, the State's analysis indicates that the Plan should control emissions of PM

2.5

and NO

in order to reach attainment. Accordingly, the State evaluated potential controls for those pollutants in the analysis of what is necessary to meet the BACM (including BACT) requirements.

For stationary and area sources, the District identifies the sources of direct PM

2.5

and NO

in the SJV that are subject to District emission control measures and provides its evaluation of these regulations for compliance with BACM requirements in Appendix C of the 2018 PM

2.5

Plan. As part of its process for identifying candidate BACM and considering the technical and economic feasibility of additional control measures, the District reviewed the EPA's guidance documents on BACM, additional guidance documents on control measures for direct PM

2.5

and NO

emission sources, and control measures implemented in other ozone and PM

2.5

nonattainment areas in California and other states.

127

Based on these analyses, the District concludes that all best available control measures for stationary and area sources are in place in the SJV for NO

and directly emitted PM

2.5

for purposes of meeting the BACM/BACT requirement for the 2012 annual PM

2.5

NAAQS.

127

2018 PM

2.5

Plan, Ch. 4, section 4.3.1.

For mobile sources, CARB identifies the sources of direct PM

2.5

and NO

in the SJV that are subject to the State's emission control measures and provides its evaluation of these regulations for compliance with BACM requirements in Appendix D of the 2018 PM

2.5

Plan. Appendix D describes CARB's process for determining BACM, including identification of the sources of direct PM

2.5

and NO

in the SJV, identification of potential control measures for such sources, assessment of the stringency and feasibility of the potential control measures, and adoption and implementation of feasible control measures.

128

CARB further discusses its current mobile source control program and additional mobile source measures in the Valley State SIP Strategy. Appendix D of the 2018 PM

2.5

Plan also describes the current efforts of the eight local jurisdiction metropolitan planning organizations (MPOs) to implement cost-effective transportation control measures (TCMs) in the SJV.

129

Based on these analyses, CARB concludes that all best available control measures for mobile sources are in place in the SJV for NO

and directly emitted PM

2.5

for purposes of meeting the BACM/BACT requirement for the 2012 annual PM

2.5

NAAQS.

128

Id. at App. D, Ch. II.

129

Id. at App. D, D-127 and D-128.

3. EPA Evaluation and Proposed Action

The first step in determining BACM is to develop a comprehensive emissions inventory of the sources of direct PM

2.5

and relevant PM

2.5

precursors that can be used with modeling to determine the effects of these sources on ambient PM

2.5

levels. Based on our review of the emission inventories provided in Appendix B of the 2018 PM

2.5

Plan and the State's and District's identification of the sources subject to control in Appendix C and Appendix D, the EPA proposes to find that the Plan appropriately identifies all sources of direct PM

2.5

and NO

that are subject to evaluation for potential control consistent with the requirements of subpart 4 of part D, title I of the Act.

The remaining steps are to identify potential control measures for each source category, determine whether available control measures or technologies are technologically and economically feasible for implementation in the area, and determine the earliest date by which those control measures or technologies found to be feasible can be implemented, in whole or in part.

130

81 FR 58010, 58083-58085. The EPA's recommended steps for a BACM demonstration are substantively similar to the required steps for an MSM demonstration in 40 CFR 51.1010(b).

We provide an evaluation of many of the District's control measures for stationary sources and area sources in section III of the EPA's “Technical Support Document, EPA Evaluation, San Joaquin Valley Serious Area Plan for the 2012 Annual PM

2.5

NAAQS,” December 2021 (“EPA's 2012 Annual PM

2.5

TSD”).

Mobile source categories for which CARB has primary responsibility for reducing emissions in California include most new and existing on- and non-road engines and vehicles and motor vehicle fuels. The SJV PM

2.5

Plan's BACM demonstration provides a general description of CARB's key mobile source programs and regulations and a comprehensive table listing on-road and non-road mobile source regulatory actions taken by CARB since 1985.

131

2018 PM

2.5

Plan, App. D, Table 17.

Appendix D of the 2018 PM

2.5

Plan describes the current efforts of the eight local jurisdiction MPOs to implement cost-effective TCMs in the SJV.

132

TCMs are projects that reduce air pollutants from transportation sources by reducing vehicle use, traffic congestion, or vehicle miles traveled. The eight MPOs in the SJV currently implement TCMs as part of the Congestion Mitigation and Air Quality cost effectiveness policy adopted by the eight local jurisdiction MPOs and in the development of each Regional Transportation Plan (RTP). The Congestion Mitigation and Air Quality policy, which is included in a number of the District's prior attainment plan submissions for the ozone and PM

2.5

NAAQS, provides a standardized process for distributing 20% of the Congestion Mitigation and Air Quality funds to projects that meet a minimum cost effectiveness threshold beginning in fiscal year 2011. The MPOs revisited the minimum cost effectiveness standard during the development of their 2018 RTPs and 2019 Federal Transportation Improvement Program and concluded that they were implementing all reasonable transportation control measures.

133

Appendix D of the District's “2016 Ozone Plan for 2008 8-Hour Ozone Standard,” adopted June 16, 2016, contains a listing of adopted TCMs for the SJV.

134

132

Id. at App. D, D-127 and D-128.

133

Id. at App. D, D-127.

134

Id. and SJVUAPCD, “2016 Ozone Plan for 2008 8-Hour Ozone Standard” (adopted June 16, 2016), App. D, Attachment D, tables D-10 to D-17.

We have reviewed the State's and District's analysis and determination in the SJV PM

2.5

Plan that their baseline mobile, stationary, and area source control measures meet the requirements for BACM for sources of direct PM

2.5

and applicable PM

2.5

plan precursors (

i.e.,

) for purposes of the 2012 annual PM

2.5

NAAQS. In our review, we considered our evaluation of the State's and District's rules in connection with our approval of the demonstrations for BACM (including BACT) and MSM for the 2006 24-hour PM

2.5

NAAQS.

135

We conclude that the evaluation processes followed by CARB and the District in the SJV PM

2.5

Plan to identify potential BACM were generally consistent with the requirements of the PM

2.5

SIP Requirements Rule, the State's and District's evaluation of potential measures is appropriate, and the State and District have provided reasoned justifications for their rejection of potential measures based on technological or economic infeasibility. We also agree with the District's conclusion that the eight MPOs are implementing all reasonable TCMs in the SJV and propose to find that these TCMs implement BACM for transportation sources.

135

85 FR 44192. The EPA provides a more detailed evaluation of many of the District's control measures for stationary and area sources in two supporting documents: The EPA's “Technical Support Document, EPA Evaluation of BACM/MSM, San Joaquin Valley PM

2.5

Plan for the 2006 PM

2.5

NAAQS,” February 2020; and the EPA's “Response to Comments Document for the EPA's Final Action on the San Joaquin Valley Serious Area Plan for the 2006 PM

2.5

NAAQS,” June 2020.

For the foregoing reasons, we propose to find that the SJV PM

2.5

Plan provides for the implementation of BACM for sources of direct PM

2.5

and NO

as expeditiously as practicable in accordance with the requirements of CAA section 189(b)(1)(B), and in satisfaction of the Serious area plan requirements for the 2012 annual PM

2.5

NAAQS.

E. Nonattainment New Source Review Requirements Under CAA Section 189(e)

Section 189(e) of the CAA specifically requires that the control requirements applicable to major stationary sources of direct PM

2.5

also apply to major stationary sources of PM

2.5

precursors, except where the Administrator determines that such sources do not contribute significantly to PM

2.5

levels that exceed the standards in the area.

136

The control requirements applicable to major stationary sources of direct PM

2.5

in a Serious PM

2.5

nonattainment area include, at minimum, the requirements of a nonattainment NSR permit program meeting the requirements of CAA sections 172(c)(5) and 189(b)(3). The publication of our final action to reclassify the SJV area as Serious nonattainment for the 2012 annual PM

2.5

NAAQS established a deadline of June 27, 2023, for the State to submit nonattainment NSR SIP revisions addressing the requirements of CAA sections 189(b)(3) and 189(e) of the Act for the 2012 annual PM

2.5

NAAQS.

137

136

General Preamble, 13539 and 13541-13542.

137

86 FR 67343, 67347.

California submitted nonattainment NSR SIP revisions to address the subpart 4 requirements for the Serious area attainment plan for SJV on November 20, 2019.

138

We will act on that submission through a separate rulemaking, as appropriate.

138

Letter dated November 15, 2019, from Richard W. Corey, Executive Officer, CARB, to Michael Stoker, Regional Administrator, EPA Region IX.

F. Attainment Demonstration

1. Requirements for Attainment Demonstration

Section 189(b)(1)(A) of the CAA requires that each Serious area plan include a demonstration (including air quality modeling) that the plan provides for attainment of the relevant PM

2.5

NAAQS by the applicable attainment date. The PM

2.5

SIP Requirements Rule explains that Serious area attainment plans under CAA sections 189(b) must include a demonstration (including air quality modeling) that the control

strategy provides for attainment of the PM

2.5

NAAQS as expeditiously as practicable.

139

For purposes of determining the attainment date that is as expeditious as practicable, the state must conduct future year modeling that takes into account emissions growth, known controls (including any controls determined to be RACM, RACT, and additional reasonable measures, and BACM, BACT, and additional feasible measures), and any other emissions controls that are needed for expeditious attainment of the NAAQS.

140

The regulatory requirements for Serious area plans are codified at 40 CFR 51.1010 (control strategy requirements) and 40 CFR 51.1011(b) (attainment demonstration and modeling requirements).

139

40 CFR 51.1011(b)(1); 81 FR 58010, 58087-58088.

140

40 CFR 51.1010(a); 81 FR 58010, 58089-58090.

2. Summary of State's Submission

The SJV PM

2.5

Plan includes a modeled demonstration projecting attainment of the 2012 annual PM

2.5

NAAQS in the SJV by December 31, 2025, based on emission reductions from implementation of baseline control measures and the development, adoption, and implementation of additional control measures to meet specific enforceable commitments. We have summarized the State's air quality modeling for demonstrating attainment in section IV.C.2 of this proposed rule. Table 3 shows the 2013 base year and 2025 projected future year annual PM

2.5

design values at monitoring sites in the SJV. As recommended by the EPA's guidance, the 2013 base year design value for modeling purposes is a weighted average of three monitored design values (for 2010-2012, 2011-2013, and 2012-2014), to minimize the influence of year-to-year variability. The highest 2025 projected design value is 12.0 μg/m

at the Bakersfield-Planz and Madera monitoring sites, consistent with demonstrating attainment of the 12.0 μg/m

level of the 2012 annual PM

2.5

NAAQS.

141

As discussed in section IV.B.3.a of this proposed rule, the State notes that Madera concentrations are biased high. 2018 PM

2.5

Plan, App. G, 14.

Table 3—Base Year and Projected Attainment Year Annual PM

2.5

Design Values at Monitoring Sites in the San Joaquin Valley

Monitoring site

2013 Base

design value

(μg/m

)

2025 Projected

design value

(μg/m

)

Bakersfield-Planz

17.2

12.0

Madera

16.9

12.0

Hanford

16.5

10.5

Visalia

16.2

11.5

Clovis

16.1

11.4

Bakersfield-California

16.0

11.0

Fresno-Garland

15.0

10.4

Turlock

14.9

11.1

Fresno-Hamilton & Winery

14.2

10.0

Stockton

13.1

10.6

Merced-S. Coffee

13.1

9.6

Modesto

13.0

9.9

Merced-M Street

11.0

8.6

Manteca

10.1

8.0

Tranquility

7.7

5.5

Source: 2018 PM

2.5

Plan, Table 7-3.

The SJV PM

2.5

Plan's control strategy to reduce emissions from sources of NO

and direct PM

2.5

is presented in Chapter 4 (“Attainment Strategy for PM

2.5

”)

142

and related supporting information in the Plan's control strategy appendices, including Appendix C (“Stationary Source Control Measure Analyses”), Appendix D (“Mobile Source Control Measures Analyses”), and Appendix E (“Incentive-Based Strategy”). Most of the projected emission reductions are achieved by baseline measures—

i.e.,

the combination of State and District measures adopted prior to the State's and District's adoption of the Plan—that will achieve ongoing emission reductions from the 2013 base year to the 2025 projected attainment year.

142

Consistent with the State and District's determination that ammonia, SO

, and VOC do not contribute significantly to PM

2.5

levels exceeding the NAAQS in the SJV, the Plan's control strategy focuses on reductions in emissions of direct PM

2.5

and NO

. CARB Staff Report, 12. Nonetheless, the Plan projects the following annual average emission reductions from the 2013 base year to 2025: 0.5 tpd reductions in SO

(5.9%), 30.0 tpd reductions in VOC (9.3%), and 4.9 tpd reductions in ammonia (1.5%). 2018 PM

2.5

Plan, App. B, tables B-3, B-4, and B-5.

The remainder of the emission reductions are to be achieved by additional measures to meet enforceable commitments, including potential regulatory and incentive-based measures and, as necessary, substitute measures.

143

In the Valley State SIP Strategy and the 2018 PM

2.5

Plan, CARB and the District, respectively, included commitments to take action on specific measures by specific years or to develop substitute measures (referred to as “control measure commitments”) and to achieve specified amounts of NO

and direct PM

2.5

emission reductions by certain dates (referred to as “aggregate tonnage commitments”).

144

We refer to these complementary commitments herein as “aggregate commitments.”

143

In this proposed rule, the term “substitute measures” means additional control measures that were not identified in CARB and the District's original control measure commitments in adopting the Valley State SIP Strategy and the 2018 PM

2.5

Plan, respectively. The “substitute” aspect primarily relates to emission reductions (

i.e.,

providing emission reductions where any adopted measure achieves less emission reductions than originally estimated, and/or providing emission reductions in lieu of any originally planned measure that is not adopted). They are also sometimes referred to as “alternative measures” in the SJV PM

2.5

Plan and adopting resolutions.

144

CARB Resolution 18-49 and SJVUAPCD Governing Board Resolution 18-11-16, paragraph 6.

CARB's control measure commitments include 12 regulatory measures and 3 incentive-based measures with implementation anticipated to start no later than 2024.

145

The District's control measure commitments include nine regulatory measures and three incentive-based measures with implementation anticipated to start no later than 2024.

146

We provide further detail on CARB and the District's control measure commitments both in sections IV.F.3.b and IV.F.3.c of this proposed rule and in section IV.A of the EPA's 2012 Annual PM

2.5

TSD.

145

Valley State SIP Strategy, Table 7. The schedule of proposed SIP measures in Table 7 includes two additional CARB measures: The second phase of the Advanced Clean Cars Program (“ACC 2”) and the “Cleaner In-Use Agricultural Equipment” measures. However, these measures are not scheduled for implementation until 2026 and 2030, respectively, which is after the January 1, 2025 implementation deadline under 40 CFR 51.1011(b)(5) for control measures necessary for attainment by December 31, 2025. Therefore, we are not reviewing these measures as part of the control strategy to attain the 2012 annual PM

2.5

NAAQS in the SJV.

146

2018 PM

2.5

Plan, Ch. 4, tables 4-3 and 4-5.

CARB's aggregate tonnage commitments are “to achieve the aggregate emissions reductions outlined in the Valley State SIP Strategy of 32 tpd of NO

and 0.9 tpd of PM

2.5

emissions reductions in the San Joaquin Valley by 2024 and 2025.”

147

The Valley State SIP Strategy explains that CARB's overall commitment is to “achieve the total emission reductions necessary to attain the federal air quality standards, reflecting the combined reductions from the existing control strategy and new measures” and that “if a particular measure does not get its expected emissions reductions, the State is still committed to achieving the total aggregate emission reductions.”

148

147

CARB Resolution 18-49.

148

2018 PM

2.5

Plan, Ch. 4, 4-29.

The District's aggregate tonnage commitments are to “achieve the aggregate emissions reductions of 1.88 tpd of NO

and 1.3 tpd of PM

2.5

by 2024/2025” through adoption and implementation of these measures or, if the total emission reductions from these rules or measures are less than these amounts, “to adopt, submit, and implement substitute rules and measures that achieve equivalent reductions in emissions of direct PM

2.5

or PM

2.5

precursors” in the same implementation timeframes.

149

SJVUAPCD Governing Board Resolution 18-11-16, paragraph 6.

CARB and the District's aggregate tonnage commitments sum to 33.88 tpd NO

and 2.2 tpd direct PM

2.5

emission reductions. We provide further detail on CARB and the District's aggregate tonnage commitments in sections IV.F.3.b and IV.F.3.d of this proposed rule and in section IV.B of the EPA's 2012 Annual PM

2.5

TSD.

We note that the SJV PM

2.5

Plan generally relies on annual average emission inventory and control strategy estimates, consistent with the annual average form of the 2012 annual PM

2.5

NAAQS. Table 4 provides a summary of the 2013 base year emissions and the reductions from baseline measures, additional State measures, and additional District measures that the Plan projects will result in attainment of the 2012 annual PM

2.5

NAAQS in the SJV by December 31, 2025.

150

Emission reductions from baseline measures are calculated as the sum of all stationary, area, and mobile source emission reductions from 2013 to 2025 in App. B of the 2018 PM

2.5

Plan.

Table 4—Summary of the SJV PM

2.5

Plan's Annual Average Emission Reductions To Attain the 2012 Annual PM

2.5

NAAQS by December 31, 2025

(tpd)

% of 2013

base year NO

emissions

Direct PM

2.5

(tpd)

% of 2013-

base year PM

2.5

emissions

2013 Base Year Emissions

317.2

62.5

Baseline Measure Emission Reductions (2013-2025)

173.5

54.7

4.2

6.7

Additional CARB Measures

10.1

0.9

1.4

Additional District Measures

1.88

0.6

1.3

2.1

Total 2013-2025 Emission Reductions (B+C+D)

207.38

65.4

6.4

10.2

Source: 2018 PM

2.5

Plan, Appendix B, tables B-1 and B-2, and Ch. 4, tables 4-3 and 4-7.

3. EPA Evaluation and Proposed Action

The EPA must make several findings in order to approve the modeled attainment demonstration in an attainment plan SIP submission. First, we must find that the attainment demonstration's technical bases, including the emissions inventories and air quality modeling, are adequate. As discussed in section IV.A of this proposed rule, the EPA proposes to approve the emissions inventories on which the State based the SJV PM

2.5

Plan's attainment demonstration and related provisions. Furthermore, as discussed in section IV.C of this proposed rule, the EPA has evaluated the State's choice of model and the extensive discussion in the Modeling Protocol about modeling procedures, tests, and performance analyses. We consider the analyses consistent with the EPA's guidance on modeling for PM

2.5

attainment planning purposes. Based on these reviews, we propose to find that the modeling in the Plan is adequate for the purposes of supporting the RFP demonstration and demonstration of attainment by 2025, and thus propose to approve the air quality modeling. For further detail, see the EPA's February 2020 Modeling TSD.

Second, we must find that the attainment plan SIP submission provides for expeditious attainment through the timely implementation of the control strategy, including RACM, BACM, and any other emission controls that are needed for expeditious attainment. In the EPA's final rule on the SJV Moderate area plan for the 2012 annual PM

2.5

NAAQS, the EPA approved the State's demonstration of RACM (including RACT) and additional reasonable measures for all sources of direct PM

2.5

and NO

, under CAA section 189(a)(1)(C) and 40 CFR 51.1009 for purposes of the 2012 annual PM

2.5

NAAQS.

151

As discussed in section IV.C of this proposed rule, the EPA now proposes to approve the SJV PM

2.5

Plan's demonstration of BACM (including BACT) under CAA section 189(b)(1)(B).

151

Our approval of the State's demonstration of RACM and additional reasonable measures was informed by the State's control stringency demonstrations in both the Moderate area plan (2016 PM

2.5

Plan) and the Serious area plan (2018 PM

2.5

Plan) for the 2012 annual PM

2.5

NAAQS in the SJV. 86 FR 49100, 49115-49116.

Third, the EPA must find that the emissions reductions that are relied on

for attainment in the SIP submission are creditable. As discussed in subsections IV.F.3.a through IV.F.3.e of this proposed rule, the SJV PM

2.5

Plan relies principally on already adopted and approved rules to achieve the emissions reductions needed to attain the 2012 annual PM

2.5

NAAQS in the SJV by December 31, 2025. The balance of the reductions that the State has modeled to achieve attainment by this date is currently represented by enforceable commitments that account for 13.8% of the NO

and 8.0% of the direct PM

2.5

emissions reductions needed for attainment.

The EPA may accept enforceable commitments in lieu of adopted control measures in attainment demonstrations when the circumstances warrant it and the commitments meet three criteria the EPA has established for this purpose. The EPA is proposing to find that circumstances here warrant the consideration of enforceable commitments and that the three criteria are met: (1) The commitments constitute a limited portion of the required emissions reductions, (2) both the State and the District have demonstrated their capability to meet their commitments, and (3) the commitments are for an appropriate timeframe. We therefore propose to approve the State's reliance on these enforceable commitments in its attainment demonstration.

Based on these evaluations, we propose to determine that the SJV PM

2.5

Plan provides for attainment of the 2012 annual PM

2.5

NAAQS by December 31, 2025, consistent with the requirements of CAA sections 189(b)(1)(A). We present the basis for this proposed determination in subsections IV.F.3.a through IV.F.3.e of this proposal and provide further detail of our evaluation of baseline measures and the additional measures and aggregate commitments in sections II and IV, respectively, of the EPA's 2012 Annual PM

2.5

TSD. In the following subsections we first address the baseline measures that are in effect in the SJV; we then describe the control measure and aggregate tonnage commitments submitted with the Plan; next, we evaluate progress that the State and District have made since submission of the Plan, on both the control measures and the aggregate tonnage commitments; finally we apply the three-factor test for reliance on enforceable commitments to demonstrate attainment.

(a) Baseline Measures

Baseline measures will provide the majority of emissions reductions needed to attain the 2012 annual PM

2.5

NAAQS in the SJV, amounting to approximately 83.7% of the total NO

emission reductions and 65.6% of the total direct PM

2.5

emission reductions necessary to attain.

152

The EPA calculated these percentages as follows: Annual average baseline NO

reductions from 2013 to 2025 are 173.5 tpd of 207.38 tpd modeled to result in attainment (83.7%) and annual average baseline direct PM

2.5

reductions are 4.1 tpd of 6.3 tpd modeled to result in attainment (65.1%). 2018 PM

2.5

Plan, Ch. 4 and App. B.

In the 2018 PM

2.5

Plan, the State explains that mobile sources emit over 85% of the NO

in the SJV and that CARB has adopted and amended regulations to reduce public exposure to diesel particulate matter, which includes direct PM

2.5

, and NO

, from “fuel sources, freight transport sources like heavy-duty diesel trucks, transportation sources like passenger cars and buses, and non-road sources like large construction equipment.”

153

2018 PM

2.5

Plan, Ch. 4, 4-9 and Valley State SIP Strategy, 4. For CARB's analysis of its mobile source measures for BACM and MSM, see 2018 PM

2.5

Plan, App. D, including analyses for on-road light-duty vehicles and fuels (starting page D-17), on-road heavy-duty vehicles and fuels (starting page D-35), and non-road sources (starting page D-64).

Given the need for substantial emissions reductions from mobile and area sources to meet the NAAQS in California nonattainment areas, the State of California has developed stringent control measures for on-road and non-road mobile sources and the fuels that power them. California has unique authority under CAA section 209 (subject to a waiver by the EPA) to adopt and implement new emissions standards for many categories of on-road vehicles and engines and new and in-use non-road vehicles and engines. The EPA has approved multiple mobile source regulations for which waivers or authorizations have been issued as revisions to the California SIP.

154

See,

e.g.,

81 FR 39424, 82 FR 14447, and 83 FR 23232.

CARB's mobile source program extends beyond regulations that are subject to the waiver or authorization process set forth in CAA section 209 to include standards and other requirements to control emissions from in-use heavy-duty trucks and buses, gasoline and diesel fuel specifications, and many other types of mobile sources. Generally, these regulations have also been submitted and approved as revisions to the California SIP.

155

See,

e.g.,

the EPA's approval of standards and other requirements to control emissions from in-use heavy-duty diesel trucks, 77 FR 20308 (April 4, 2012), and revisions to the California on-road reformulated gasoline and diesel fuel regulations, 75 FR 26653 (May 12, 2010).

As to stationary sources, in the 2018 PM

2.5

Plan, the State explains that stringent regulations adopted for prior attainment plans continue to reduce emissions of NO

and direct PM

2.5

156

Specifically, Table 4-1 of the 2018 PM

2.5

Plan (“District Rules Reducing PM and NO

Emissions in the Valley”) identifies 33 District measures that limit NO

and direct PM

2.5

emissions.

157

The EPA has approved each of the identified measures into the California SIP,

158

with two exceptions.

156

2018 PM

2.5

Plan, Ch. 4, 4-3. For the District's analysis of its stationary source measures for BACM and MSM, see 2018 PM

2.5

Plan, App. C.

157

Id. at Ch. 4, Table 4-1.

158

See EPA Region IX's website for information on District control measures that have been approved into the California SIP, available at:

https://www.epa.gov/sips-ca/epa-approved-san-joaquin-valley-unified-air-district-regulations-california-sip.

First, the District amended Rule 4905 (“Natural Gas-fired, Fan-type, Residential Central Furnaces”) on June 21, 2018, to extend the period during which manufacturers may pay emission fees in lieu of meeting the rule's NO

emission limits.

159

CARB submitted the amended rule to the EPA on November 21, 2018. However, the District amended Rule 4905 once more on October 15, 2020, to further extend the period during which manufacturers of weatherized furnaces may pay emission fees in lieu of meeting the rule's NO

emission limits.

160

CARB submitted the rule as amended October 15, 2020, to the EPA on December 30, 2020, and simultaneously withdrew the rule as amended June 21, 2018.

161

The EPA has not yet proposed any action on this submission.

159

SJVUAPCD, Final Draft Staff Report, “Proposed Amendments to Rule 4905 (Natural Gas-fired, Fan-type Central Furnaces),” 2.

160

SJVUAPCD, “Item Number X: Adopt Proposed Amendments to Rule 4905 (Natural Gas-Fired, Fan-Type Furnaces),” October 15, 2020, 3, including Final Draft Staff Report, “Proposed Amendments to Rule 4905 (Natural Gas-Fired, Fan-Type Furnaces).”

161

Letter dated December 28, 2020, from Richard W. Corey, Executive Officer, CARB, to John Busterud, Regional Administrator, EPA Region IX.

The EPA approved a prior version of Rule 4905 into the California SIP on March 29, 2016.

162

As part of that rulemaking, the EPA noted that because of the option in Rule 4905 to pay mitigation fees in lieu of compliance with emission limits, emission reductions associated with the rule's emission limits would not be creditable in any attainment plan without additional documentation.

163

Until the District submits the necessary documentation to credit emission reductions achieved by Rule 4905

toward an attainment control strategy, this rule is not creditable for SIP purposes. The 2018 PM

2.5

Plan indicates that the District attributed annual average emission reductions of 0.31 tpd NO

between 2013 and 2025 to Rule 4905.

164

These emission reductions would not materially affect the attainment demonstration in the SJV PM

2.5

Plan.

162

81 FR 17390 (March 29, 2016) (approving Rule 4905 as amended January 22, 2015).

163

EPA Region IX, “Technical Support Document for EPA's Proposed Rulemaking for the California State Implementation Plan (SIP), San Joaquin Valley Unified Air Pollution Control District's Rule 4905, Natural Gas-Fired, Fan-Type Central Furnaces,” October 5, 2015, n. 8.

164

2018 PM

2.5

Plan, App. C, C-290.

Second, the 2018 PM

2.5

Plan lists Rule 4203 (“Particulate Matter Emissions from Incineration of Combustible Refuse”) as a baseline measure. This rule has not been approved into the California SIP.

165

Appendix C of the 2018 PM

2.5

Plan indicates, however, that the emissions inventory for incineration of combustible refuse is 0.00 tpd of NO

and 0.00 tpd direct PM

2.5

from 2013 through 2025.

166

Thus, although the District included this rule as a baseline measure, there are no meaningful reductions associated with this rule that would affect the attainment demonstration in the SJV PM

2.5

Plan.

165

The EPA does not have any pending SIP submission for Rule 4203.

166

2018 PM

2.5

Plan, App. C, C-46.

In sum, although Table 4-1 of the 2018 PM

2.5

Plan identifies two baseline measures that are not creditable for SIP purposes at this time, we conclude that the total emission reductions attributed to these two measures in the future baseline inventories would not materially affect the attainment demonstration in the Plan.

(b) Additional Measures and Aggregate Commitments

The SJV PM

2.5

Plan identifies a series of additional CARB and District commitments to achieve emission reductions through additional control measures beyond baseline measures that will contribute to expeditious attainment of the 2012 annual PM

2.5

NAAQS. As discussed in section IV.F.2 of this proposed rule, for mobile sources, CARB's commitment identifies a list of 12 State regulatory measures and 3 incentive-based measures that CARB has committed to propose to its Board for consideration by specific years.

167

For stationary sources, the District's commitment identifies a list of nine regulatory measures and three incentive-based measures that the District has committed to propose to its Board for consideration by specific years.

168

The Plan contains CARB and the District's estimates of the emission reductions that would be achieved by each of these additional measures, if adopted.

169

167

CARB Resolution 18-49, Attachment A and Valley State SIP Strategy, Table 7 (“State Measures and Schedule for the San Joaquin Valley”).

168

SJVUAPCD Governing Board Resolution 18-11-16 and 2018 PM

2.5

Plan, Table 4-4 (“Proposed Regulatory Measures”) and Table 4-5 (“Proposed Incentive-Based Measures”).

169

2018 PM

2.5

Plan, Ch. 4, Table 4-3 (”Emission Reductions from District Measures”) and Table 4-9 (”San Joaquin Valley Expected Emission Reductions from State Measures”) and Valley State SIP Strategy, Table 8 (“San Joaquin Valley Expected Emission Reductions from State Measures”).

CARB's commitments are contained in CARB Resolution 18-49 (October 25, 2018) and the Valley State SIP Strategy and consist of two parts: A control measure commitment and a tonnage commitment. First, CARB has committed to “begin the measure's public process and bring to the Board for consideration the list of proposed SIP measures outlined in the

Valley State SIP Strategy

and included in Attachment A, according to the schedule set forth.”

170

By email dated November 12, 2019, CARB confirmed that it intended to begin the public process on each measure by discussing the proposed regulation or program at a public meeting (workshop, working group, or Board hearing) or in a publicly-released document and to then propose the regulation or program to its Board.

171

Second, CARB has committed “to achieve the aggregate emissions reductions outlined in the

Valley State SIP Strategy

of 32 tpd of NO

and 0.9 tpd of PM

2.5

emissions reductions in the San Joaquin Valley by 2024 and 2025.”

172

173

170

CARB Resolution 18-49, 5.

171

Email dated November 12, 2019, from Sylvia Vanderspek, CARB to Anita Lee, EPA Region IX, “RE: SJV PM

2.5

information” (attaching “Valley State SIP Strategy Progress”) and CARB Staff Report, 14.

172

CARB Resolution 18-49, 5.

173

Valley State SIP Strategy, 7.

The District's commitments are contained in SJVUAPCD Governing Board Resolution 18-11-16 (November 15, 2018) and Chapter 4 of the 2018 PM

2.5

Plan and similarly consist of two parts: A control measure commitment and a tonnage commitment. First, the District has committed to “take action on the rules and measures committed to in Chapter 4 of the Plan by the dates specified therein, and to submit these rules and measures, as appropriate, to CARB within 30 days of adoption for transmittal to EPA as a revision to the [SIP].”

174

By email dated November 12, 2019, the District confirmed that it intended to take action on the listed rules and measures by beginning the public process on each measure,

i.e.,

discussing the proposed regulation or program at a public meeting, including a workshop, working group, or Board hearing, or in a publicly-released document, and then proposing the rule or measure to the SJVUAPCD Governing Board.

175

Second, the District has committed to “achieve the aggregate emissions reductions of 1.88 tpd of NO

and 1.3 tpd of PM

2.5

or PM

2.5

precursors” in the same implementation timeframes.

176

174

SJVUAPCD Governing Board Resolution 18-11-16, 10-11.

175

Email dated November 12, 2019, from Jon Klassen, SJVUAPCD to Wienke Tax, EPA Region IX, “RE: follow up on aggregate commitments in SJV PM

2.5

plan” (attaching “District Progress in Implementing Commitments with 2018 PM

2.5

Plan”).

176

SJVUAPCD Governing Board Resolution 18-11-16, 10-11.

In October 2021, CARB and the District provided the “Progress Report and Technical Submittal for the 2012 PM

2.5

Standard San Joaquin Valley” (2021 Progress Report) to describe their progress to date in developing and adopting the additional measures identified in their control measure commitments. The 2021 Progress Report provides status updates on the substance of each measure and the timing of board consideration for both adopted and remaining control measure commitments.

177

It also provides a side-by-side comparison of the original emission reduction estimates in the SJV PM

2.5

Plan for each control measure commitment and updated emission reduction estimates for each based on technical analyses for adopted measures and draft measures and/or

documentation in development for forthcoming regulations.

178

177

“Progress Report and Technical Submittal for the 2012 PM

2.5

Standard San Joaquin Valley,” October 19, 2021. Transmitted to the EPA by letter dated October 20, 2021, from Richard W. Corey, Executive Officer, CARB, to Deborah Jordan, Acting Regional Administrator, EPA Region IX. See sections of 2021 Progress Report entitled “Progress in Implementing District Measures” and “Progress in Implementing CARB Measures.”

178

2021 Progress Report, tables 2 and 3.

Together, as of December 2021, CARB and the District together have adopted 18 measures of the 27 control measure commitments in the SJV PM

2.5

Plan and have begun the public process on 5 of the remaining control measure commitments. For CARB's portion, CARB has adopted 10 of the 15 measures in its commitment (including one incentive-based measure) and begun the public process on 3 of its remaining 5 measures. The adopted measures include, for example, the Heavy-Duty Vehicle Inspection and Maintenance Program (“Heavy-Duty I/M”), the California Heavy-Duty Low-NO

Engine Standard, the Small Off-Road Engines (SORE) regulation, and the Accelerated Turnover of Agricultural Equipment Incentive Projects (“Agricultural Equipment Incentive Measure”). For the District's portion of the control measure commitments, the District has adopted 8 of the 12 measures in its commitment (including one incentive-based measure) and begun the public process on two of the remaining four measures. The adopted measures include, for example, amendments to Rule 4311 (“Flares”), Rule 4702 (“Internal Combustion Engines”), and Rule 4901 (“Woodburning Fireplaces and Wood Burning Heaters”) (Hot-spot strategy), and the Residential Wood Burning Devices Incentive Projects measure.

Accordingly, the EPA considers that, although CARB and the District have not met the commitment deadlines for several measures, as discussed further in this proposed rule, they have nonetheless made substantial progress in developing and adopting the regulatory measures listed in their respective control measure commitments. We provide further detail on CARB and the District's control measure commitments in section IV.A of the EPA's 2012 Annual PM

2.5

TSD (including tables IV-A and IV-B regarding CARB and the District's control measure commitments, respectively).

Regarding the remaining nine measures not yet proposed for board consideration, we note that one measure, Rule 4550 (“Conservation Management Practices”), has an action year of 2022 in the 2018 PM

2.5

Plan (

i.e.,

it is not yet due for board consideration) and that four regulatory measures and four incentive-based measures are overdue.

The four overdue regulatory measures are: The Zero-Emission Airport Ground Support Equipment measure; the Zero-Emission Off-Road Forklift Regulation Phase 1 measure; the Low-emission Diesel Fuel Requirement; and Rule 4692 (“Commercial Under-fired Charbroiling (Hot-spot Strategy)”). While they have not proposed these measures to their respective boards, CARB and the District timely began the public process on each of the four measures. CARB anticipates board consideration of the diesel fuel measures in 2022 and the forklift measure as early as 2022 and continues to develop the airport ground support equipment measure. The District adopted the “Commercial Underfired Charbroiling Emission Reduction Strategy” on December 17, 2020, and continues to evaluate potential amendments to Rule 4692 in the near future.

179

Id. at 8-9, 20-22, and tables 2 and 3.

The four overdue incentive-based control measures are for the Accelerated Turnover of Trucks and Buses Incentive Projects, the Accelerated Turnover of Off-road Equipment Incentive Projects, the Agricultural Operation Internal Combustion Engines Incentive Projects, and the Commercial Under-fired Charbroiling Incentive Projects. CARB and the District continue to invest in reducing emissions from these sources, as well as other incentive programs not named among the 27 control measure commitments, such as those for nut harvesting and landscape maintenance equipment.

180

However, while CARB and the District have discussed the proposed programs at certain board hearings,

181

the EPA is not aware that CARB or the District have started public process for the four incentive-based control measure commitments as enforceable measures to be submitted for inclusion as control measures in the California SIP.

180

CARB, “Long-Term Heavy-Duty Investment Strategy, Including Fiscal Year 2020-21 Three-Year Recommendations for Low Carbon Transportation Investments,” (App. D to CARB's “Proposed Fiscal Year 2021-22 Funding Plan for Clean Transportation Incentives”), release date October 8, 2021; and SJVUAPCD, “Comprehensive Annual Financial Report, Fiscal Year Ended June 30, 2020,” release date December 23, 2020. See also, 2021 Progress Report, 3 and 15.

181

For example, CARB staff discussed the Accelerated Turnover of Trucks and Buses Incentive Measure at its annual 2020 update to the CARB Board. CARB presentation, “Update on the 2018 PM

2.5

SIP for the San Joaquin Valley,” October 22, 2020. District staff discussed and adopted an emission reductions strategy for commercial under-fired charbroiling, including incentives, in December 2020. SJVUAPCD, “Item Number 11: Adopt Proposed Commercial Under-Fired Charbroiling Emission Reduction Strategy,” December 17, 2020.

Notwithstanding being overdue in presenting these incentive-based measures for board consideration, CARB and the District state that they continue to assess and/or prepare the formal documen

This text is long and has been trimmed here. Open the source document for the complete record.

This is a copy of a public record, reproduced as it was published. It is not legal advice, and it may not be the version a court would rely on. Check the official source before you cite it.