The EPA Region 9 Regional Administrator, Jared Blumenfeld, signed the following proposed rule on January 28, 2016, and 

EPA is submitting it for publication in the Federal Register (FR). While we have taken steps to ensure the accuracy of this 

Internet version of the rule, it is not the official version of the rule for purposes of compliance. Please refer to the official 

version in a forthcoming FR publication, which will appear on the Government Printing Office’s FDsys website 

(http://fdsys.gpo.gov/fdsys/search/home.action) and on Regulations.gov (http://www.regulations.gov) in Docket No. EPAR09-OAR-2015-0432.

Billing Code: 6560-50-P 

1 

ENVIRONMENTAL PROTECTION AGENCY 

40 CFR Part 52 and Part 81 

[EPA-R09-OAR-2015-0432; FRL- ] 

Approval and Disapproval of California Air Plan; San Joaquin Valley Serious Area Plan and 

Attainment Date Extension for the 1997 PM2.5 NAAQS 

AGENCY: U.S. Environmental Protection Agency. 

ACTION: Proposed rule. 

SUMMARY: The Environmental Protection Agency (EPA) is proposing to approve, conditionally 

approve, and disapprove state implementation plan (SIP) revisions submitted by California to address 

Clean Air Act (CAA or Act) requirements for the 1997 24-hour and annual fine particulate matter 

(PM2.5) national ambient air quality standards (NAAQS) in the San Joaquin Valley (SJV) Serious PM2.5

nonattainment area. As part of this action, the EPA is proposing to grant extensions of the Serious area 

attainment dates for the 1997 24-hour and annual PM2.5 NAAQS in the SJV to December 31, 2018 and 

December 31, 2020, respectively, based on a conclusion that the State has satisfied the statutory criteria 

for these extensions of the Serious area attainment date. The EPA is also proposing to approve interpollutant trading ratios for use in transportation conformity analyses. 

DATES: Any comments must arrive by [Federal Register Office: insert date 30 days after date of 

publication in the Federal Register]. 

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-OAR-2015-0432 at 

http://www.regulations.gov, or via email to mays.rory@epa.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. For either manner of submission, the EPA may 
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

2 

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 

http://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Rory Mays, Air Planning Office (AIR-2), EPA 

Region 9, (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 

II. Summary of the San Joaquin Valley 2015 PM2.5 Plan 

III. Completeness Review of the San Joaquin Valley 2015 PM2.5 Plan 

IV. Clean Air Act Requirements for PM2.5 Serious Area Plans 

A. PM2.5 Serious Area Plan Requirements 

B. Implementation of Best Available Control Measures 

C. Implementation of Reasonably Available Control Measures 

D. Extension of the Serious Area Attainment Date Beyond 2015 
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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V. Review of the San Joaquin Valley PM2.5 Serious Area Plan and Extension Application 

A. Emissions Inventory 

B. Adequate Monitoring Network 

C. PM2.5 Precursors 

D. Best Available Control Measures and Most Stringent Measures 

E. Extension of Serious Area Attainment Date Under CAA Section 188(e) 

1. Application for an Attainment Date Extension 

2. Demonstration that Attainment by Serious Area Attainment Date is Impracticable 

3. Compliance with all Requirements and Commitments in the Implementation Plan 

4. Demonstration that the Implementation Plan Includes the Most Stringent Measures 

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

F. Reasonable Further Progress and Quantitative Milestones 

G. Contingency Measures 

H. Major Stationary Source Control Requirements under CAA Section 189(e) 

I. Motor Vehicle Emission Budgets 

VI. Summary of Proposed Actions and Request for Public Comment 

VII. Statutory and Executive Order Reviews 

I. Background 

On July 18, 1997, the EPA established new national ambient air quality standards (NAAQS) for 

particles less than or equal to 2.5 micrometers (μm) in diameter (PM2.5), including an annual standard of 

15.0 micrograms per cubic meter (μg/m3) based on a 3-year average of annual mean PM2.5

concentrations, and a 24-hour (daily) standard of 65 μg/m3 based on a 3-year average of 98th percentile 
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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24-hour PM2.5 concentrations.1 The EPA established these standards after considering substantial 

evidence from numerous health studies demonstrating that serious health effects are associated with 

exposures to PM2.5 concentrations above these levels. 

Epidemiological studies have shown statistically significant correlations between elevated PM2.5

levels and premature mortality. Other important health effects associated with PM2.5 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, as well as new evidence for more subtle indicators of 

cardiovascular health. Individuals particularly sensitive to PM2.5 exposure include older adults, people 

with heart and lung disease, and children.2

PM2.5 can be emitted directly into the atmosphere as a solid or liquid particle (primary PM2.5 or 

direct PM2.5) or can be formed in the atmosphere as a result of various chemical reactions from 

precursor emissions of nitrogen oxides, sulfur oxides, volatile organic compounds, and ammonia 

(secondary PM2.5).3

 

Following promulgation of a new or revised NAAQS, the EPA is required under Clean Air Act 

(CAA) section 107(d) to designate areas throughout the nation as attaining or not attaining the NAAQS.

On January 5, 2005, the EPA published initial air quality designations for the 1997 annual and 24-hour

PM2.5 NAAQS, using air quality monitoring data for the three-year periods of 2001–2003 and 2002–

 

1

 62 FR 36852 (July 18, 1997) and 40 CFR 50.7. Effective December 18, 2006, EPA strengthened the 24-hour PM2.5 NAAQS 

by lowering the level to 35 μg/m3

. 71 FR 61144 (October 17, 2006) and 40 CFR 50.13. Effective March 18, 2013, EPA 

strengthened the primary annual PM2.5 NAAQS by lowering the level to 12.0 μg/m3

 while retaining the secondary annual 

PM2.5 NAAQS at the level of 15.0 μg/m3. 78 FR 3086 (January 15, 2013) and 40 CFR 50.18. In this preamble, all references 

to the PM2.5 NAAQS, unless otherwise specified, are to the 1997 24-hour standards (65 μg/m3) and annual standards (15.0 

μg/m3

) as codified in 40 CFR 50.7. 

2

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

3

 72 FR 20586, 20589 (April 25, 2007). 
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

5 

2004.4 These designations became effective April 5, 2005.5 The EPA designated the San Joaquin Valley 

(SJV) area as nonattainment for both the 1997 annual PM2.5 standard (15.0 μg/m3) and the 1997 24-hour 

PM2.5 standard (65 μg/m3

).6 

The SJV PM2.5 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.7 The area is home to 4 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 San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD or 

District) has primary responsibility for developing plans to provide for attainment of the NAAQS in this 

area. The District works cooperatively with the California Air Resources Board (CARB) in preparing 

attainment plans. Authority for regulating sources under State jurisdiction in the 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. 

Between 2007 and 2011, California made six SIP submissions to address nonattainment area 

planning requirements for the 1997 PM2.5 NAAQS in the SJV.8

 We refer to these submissions 

collectively as the “2008 PM2.5 Plan.” On November 9, 2011, the EPA approved all elements of the 

2008 PM2.5 Plan except for the contingency measures, which the EPA disapproved.9 As part of that 

 

4

 70 FR 944 (January 5, 2005). 

5

Id. 

6

 40 CFR 81.305. The 2001-2003 design values for the San Joaquin Valley were 21.8 μg/m3 for the annual standard and 82 

μg/m3 for the 24-hour standard. See EPA design value workbook dated August 12, 2014, worksheets “Table 3a” and “Table 

3b.” 

7

 For a precise description of the geographic boundaries of the San Joaquin Valley PM2.5 nonattainment area, see 40 CFR 

81.305. 

8

 76 FR 69896 at n. 2 (November 9, 2011). 

9

Id. at 69924. 
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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action and pursuant to CAA section 172(a)(2)(A), the EPA granted California’s request for an extension

of the attainment date for the SJV area to April 5, 2015.10 The EPA took these actions in accordance 

with the “Clean Air Fine Particle Implementation Rule,” which the EPA issued in April 2007 to assist 

states in their development of SIPs to meet the Act’s attainment planning requirements for the 1997 

PM2.5 NAAQS (hereafter “2007 PM2.5 Implementation Rule”).11 In July 2013, the State submitted a 

revised PM2.5 contingency measure plan for the SJV, which the EPA fully approved in May 2014.12

On January 4, 2013, the U.S. Court of Appeals for the D.C. Circuit (“D.C. Circuit”) issued its 

decision in a challenge by the Natural Resources Defense Council (NRDC) to the EPA’s 2007 PM2.5

Implementation Rule.13 In NRDC, the court held that the EPA erred in implementing the 1997 PM2.5

standards solely pursuant to the general implementation requirements of subpart 1, without also 

considering the requirements specific to nonattainment areas for particles less than or equal to 10 μm in 

diameter (PM10) in subpart 4, part D of title I of the CAA. The court reasoned that the plain meaning of 

the CAA requires implementation of the 1997 PM2.5 standards under subpart 4 because PM2.5 particles 

fall within the statutory definition of PM10 and are thus subject to the same statutory requirements as 

PM10. The court remanded the rule, without vacatur, and instructed the EPA “to repromulgate these rules 

pursuant to Subpart 4 consistent with this opinion.”

14

 

10 Id. Under CAA section 172(a)(2)(A), the attainment date for a nonattainment area is “the date by which attainment can be 

achieved as expeditiously as practicable, but no later than five years from the date such area was designated nonattainment,” 

except that EPA may extend the attainment date as appropriate for a period no greater than ten years from the date of 

designation as nonattainment, considering the severity of nonattainment and the availability and feasibility of pollution 

control measures. CAA section 172(a)(2)(A); see also 40 CFR 51.1004(a) and (b). 

11 72 FR 20583 (April 25, 2007), codified at 40 CFR part 51, subpart Z. This rule was premised on EPA’s prior interpretation 

of the Act as allowing for implementation of the PM2.5 NAAQS solely pursuant to the general nonattainment area provisions 

of subpart 1 and not the more specific provisions for particulate matter nonattainment areas in subpart 4 of part D, title I of 

the Act. 

12 79 FR 29327 (May 22, 2014). 

13 Natural Resources Defense Council v. EPA, 706 F.3d 428 (D.C. Cir. 2013) (“NRDC”). 

14 Id. 
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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Consistent with the NRDC decision, on June 2, 2014, the EPA published a final rule classifying 

all areas designated nonattainment for the 1997 and/or 2006 PM2.5 standards as “moderate” 

nonattainment under subpart 4.15 Because this rulemaking did not affect any action that the EPA had 

previously taken under section 110(k) of the Act on a SIP for a PM2.5 nonattainment area, the April 5, 

2015 attainment date that the EPA had approved for the SJV area in November 2011 remained in 

effect.16 On April 7, 2015, the EPA published a final rule reclassifying the SJV area as “serious” 

nonattainment under subpart 4, based on the EPA’s determination that the area could not practicably 

attain the 1997 PM2.5 standards by the April 5, 2015 attainment date.17 This reclassification was based 

upon the EPA’s evaluation of ambient air quality data from the 2003-2014 period, including the 2012–

2014 design value, indicating that it was not practicable for certain monitoring sites within the SJV area 

to show PM2.5 design values at or below the level of the 1997 PM2.5 NAAQS by April 5, 2015.18 

As a consequence of its reclassification as a Serious PM2.5 nonattainment area, the SJV area 

became subject to a new attainment date under CAA section 188(c)(2) and the requirement to submit a 

Serious area plan that satisfies the requirements of part D of title I of the Act, including the requirements 

of subpart 4, for the 1997 PM2.5 NAAQS.19 Under subpart 4, the attainment date for an area classified as 

Serious is as expeditiously as practicable, but no later than the end of the tenth calendar year following 

designation. As explained in the EPA’s final reclassification action, the Serious area plan for SJV must 

include provisions to assure that the best available control measures (BACM) for the control of direct

 

15 79 FR 31566 (June 2, 2014). As part of this rulemaking, EPA established a December 31, 2014 deadline for states to 

submit attainment-related and nonattainment new source review (NNSR) SIP elements required for PM2.5 nonattainment 

areas pursuant to subpart 4. Id. 

16 Id. at 31569. 

17 80 FR 18528 (April 7, 2015). 

18 Id. at 18529; see also proposed rule, 80 FR 1482 (January 12, 2015). Air quality data for 2012-2014 indicated that the 

highest monitors in the SJV area had design values of 19.7 μg/m3

 for the annual standard and 71 μg/m3 for the 24-hour 

standard. 

19 80 FR 18258 at 18530-18532. 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

8 

PM2.5 and PM2.5 precursors shall be implemented no later than 4 years after the area is reclassified (CAA 

section 189(b)(1)(B)), and a demonstration (including air quality modeling) that the plan provides for

attainment as expeditiously as practicable but no later than December 31, 2015, which is the latest 

permissible attainment date under CAA section 188(c)(2).20

Given the December 31, 2015 outermost attainment deadline for the SJV area under section 

188(c)(2), the EPA noted its expectation that the State would adopt and submit a Serious area plan for

the SJV well before the statutory SIP submission deadlines in CAA section 189(b)(2).21 The EPA also 

noted that, in light of the available ambient air quality data and the short amount of time available before 

the December 31, 2015 attainment date, California may choose to submit a request for an extension of 

the Serious area attainment date pursuant to CAA section 188(e) simultaneously with its submission of a 

Serious area plan for the area.22

II. Summary of the San Joaquin Valley 2015 PM2.5 Plan 

We are proposing action on two California SIP submissions that address the 1997 annual and 24-

hour PM2.5 NAAQS in the San Joaquin Valley. The first submission is the “2015 Plan for the 1997 

PM2.5 Standard,” which the State submitted to the EPA on June 25, 2015.23 The second submission is the 

“2018 Transportation Conformity Budgets for the San Joaquin Valley PM2.5 SIP, Plan Supplement,” 

which the State submitted to the EPA on August 13, 2015.24 We refer to these SIP submissions 

collectively herein as the “2015 PM2.5 Plan” or “the Plan.” The 2015 PM2.5 Plan is a PM2.5 Serious area 

plan for the SJV and includes a request to extend the applicable attainment dates for the annual and 24-

 

20 Id. 

21 Id. at 18531. 

22 Id. 

23 Letter dated June 25, 2015, from Richard Corey, Executive Officer, California Air Resources Board, to Jared Blumenfeld, 

Regional Administrator, EPA Region 9, with enclosures. 

24 Letter dated August 13, 2015, from Richard Corey, Executive Officer, California Air Resources Board, to Jared 

Blumenfeld, Regional Administrator, EPA Region 9, with enclosures. 
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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hour PM2.5 standards by five and three years, respectively, on the basis that attainment by December 31, 

2015 is impracticable, in accordance with CAA section 188(e). 

The first submission includes two sets of documents: the “2015 Plan for the PM2.5 Standard,” 

adopted by the SJVUAPCD Governing Board on April 16, 2015 and the “Staff Report, ARB Review of 

San Joaquin Valley PM2.5 State Implementation Plan,” adopted by CARB on May 21, 2015 (“CARB 

Staff Report”). Both sets of documents include Appendices A and B. To distinguish between the two 

sets of appendices, we refer to those adopted by the SJVUAPCD Governing Board simply as “Appendix 

A” (“Ambient PM2.5 Data Analysis”) and “Appendix B” (“Emission Inventory Tables”), and we refer to 

the additional appendices that accompany CARB’s Staff Report as “WOEA” for Appendix A (“San 

Joaquin Valley PM2.5 Weight of Evidence Analysis”) and “CARB Staff Report, Appendix B” for 

Appendix B (“San Joaquin Valley PM2.5 SIP Additional Emission Reductions Towards Meeting

Aggregate Commitment”). 

The 2015 PM2.5 Plan includes an Executive Summary and a description of air quality standards 

and requirements applicable to the SJV (Chapter 1), PM2.5 challenges and trends (Chapter 2, including a 

summary of the District’s determination regarding air pollutant precursors to PM2.5), and health impacts 

and risk reduction strategy (Chapter 3).25 Chapter 4 presents the SJVUAPCD’s request for an extension 

of the PM2.5 Serious area attainment date; summary arguments for how the SJVUAPCD claims it has 

met the extension requirements of CAA section 188(e), including a demonstration that attainment of the

1997 PM2.5 NAAQS by December 31, 2015 is impracticable; a demonstration, as detailed in Appendix F 

(“Attainment Demonstration (Provided by ARB)”), of attainment by the most expeditious alternative 

date practicable; and financial commitments to achieve further emission reductions by replacing heavy 

 

25 See 2015 PM2.5 Plan, Appendix A, regarding trends. 
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

10 

duty trucks and residential wood burning devices through the District’s truck replacement incentive 

program and Burn Cleaner Incentive Program, respectively. 

Chapter 5, Appendix C (“BACM and MSM for Stationary and Area Sources”), and Appendix D 

(“BACM and MSM for Mobile Sources (Provided by ARB)”) provide analyses of District and State 

rules to address the statutory requirements for Best Available Control Measures (BACM) and Most 

Stringent Measures (MSM) and the District’s calculation of de minimis thresholds for directly emitted 

PM2.5 (direct PM2.5), nitrogen oxides (NOx), and sulfur oxides (SOx). 

Chapters 6 and 7 present the District’s summary analysis to address the planning requirements 

for PM2.5 Serious nonattainment areas under subparts 1 and 4 of part D, title I of the CAA, including the 

statutory requirements for extension requests under CAA section 188(e). These include the District’s 

analysis and demonstration, in Chapter 6, of its compliance with the requirements and commitments in 

the implementation plan for the 1997 PM2.5 NAAQS, reasonably available control measures (RACM), 

reasonable further progress (RFP) and quantitative milestones, contingency measures, transportation 

conformity budgets for 2014, 2017, and 2020, and permitting of new and modified major stationary 

sources (i.e., nonattainment new source review (NSR)).26 Chapter 7 describes the State’s and District’s 

regulatory control strategy, incentive programs, technology advancement program, legislative strategy,

and public outreach.27 Finally, Chapter 8 presents the District’s commitments to evaluate opportunities 

for additional emission reductions in general, and specifically from three source categories: flares, 

asphalt, and conservation management practices. 

 

26 See also, 2015 PM2.5 Plan, Appendix B and Appendix G (“New Source Review (NSR) and Emission Reduction Credits 

(ERCs)”). 

27 See also, 2015 PM2.5 Plan, Appendix E (“Incentive and Other Non-regulatory Strategies”). 
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

11 

The additional documents adopted by CARB on May 21, 2015 supplement the analysis and 

demonstrations of those adopted by SJVUAPCD. In particular, the CARB Staff Report presents 

estimated emission reductions by 2018 and 2020 from specific District control measures; an accounting 

of how the State has complied with its control measure and emission reduction commitments in the 2008 

PM2.5 Plan; analysis of ammonia effects on reasonable further progress planning; and 2021 attainment 

year contingency reductions from specific measures.28 These additional documents also include the 

methodology and results for the attainment demonstration,29 a weight of evidence analysis for the 

attainment demonstration (WOEA), a discussion of additional emission reductions achieved towards the 

aggregate tonnage commitments of the 2008 PM2.5 Plan (CARB Staff Report, Appendix B), and 

technical clarifications for the 2015 PM2.5 Plan as a whole (Technical Clarifications).30 Finally, 

transportation conformity budgets for 2018 are presented in a supplemental SIP revision adopted July 

23, 2015 and entitled “Transportation Conformity Budgets for the San Joaquin Valley PM2.5 SIP Plan 

Supplement.” 

We present our evaluation of the 2015 PM2.5 Plan in section V of this proposed rule. Given the

overlap of some control and planning requirements between a PM2.5 Serious area plan and a request for 

extension of the PM2.5 Serious area attainment date, we generally address these requirements together 

rather than separately. For example, we address the BACM requirement for Serious area plans and the 

MSM requirement for extension requests together in section V.D. of this proposed rule. Similarly, we 

address the requirement for a Serious area attainment demonstration and the requirement to demonstrate

 

28 2015 PM2.5 Plan, “Staff Report, ARB Review of San Joaquin Valley PM2.5 State Implementation Plan,” release date April 

20, 2015, pp. 9, 17-22, 25-26, and 26-27, respectively. 

29 2015 PM2.5 Plan, “Attainment Demonstration for the San Joaquin Valley 2015 PM2.5 Plan for the Annual (15 μg/m3

) and 

24-hour (65 μg/m3) Standards.” 

30 2015 PM2.5 Plan, “Technical Clarifications to the 2015 San Joaquin Valley PM2.5 State Implementation Plan.” 
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

12 

attainment by the most expeditious alternative date practicable, for purposes of requesting an extension 

of the attainment date, together in section V.E.5 of this proposed rule. 

III. Completeness Review of the San Joaquin Valley 2015 PM2.5 Plan 

CAA sections 110(a)(1) and (2) and 110(l) require each state to provide reasonable public notice 

and opportunity for public hearing prior to the adoption and submission of a SIP or SIP revision to the 

EPA. To meet this requirement, every SIP submission should include evidence that adequate public 

notice was given and an opportunity for a public hearing was provided consistent with the EPA’s 

implementing regulations in 40 CFR 51.102. 

Both the District and CARB satisfied applicable statutory and regulatory requirements for 

reasonable public notice and hearing prior to adoption and submission of the 2015 PM2.5 Plan. The 

District conducted a public workshop, provided a public comment period, and held a public hearing 

prior to the adoption of the main SIP submission on April 16, 2015.31 CARB provided the required 

public notice and opportunity for public comment prior to its May 21, 2015 public hearing and adoption

of the main SIP submission.32 CARB then adopted its supplemental SIP submission pertaining to 2018 

transportation conformity motor vehicle emission budgets at its July 23, 2015 Board meeting after 

reasonable public notice.33 Each submission includes proof of publication of notices for the respective 

public hearings. We find, therefore, that the 2015 PM2.5 Plan meets the procedural requirements for 

public notice and hearing in CAA sections 110(a) and 110(l). 

 

31 SJVUAPCD, “Notice of Public Workshop [on] Draft Plan for the 1997 PM2.5 Standard,” March 2, 2015; SJVUAPCD, 

“Notice of Public Hearing [to] Adopt Proposed 2015 Plan for the 1997 PM2.5 Standard,” March 17, 2015; and SJVUAPCD 

Governing Board Resolution 15-4-7A, “In the Matter of Adopting the San Joaquin Valley Unified Air Pollution Control 

District 2015 Plan for the 1997 PM2.5 Standard,” April 16, 2015. 

32 CARB, “Notice of Public Meeting to Consider Approval of the San Joaquin Valley PM2.5 State Implementation Plan,” 

April 20, 2015; and CARB Board Resolution 15-9, “San Joaquin Valley PM2.5 State Implementation Plan,” May 21, 2015. 

33 CARB, “Notice of Public Meeting to Consider the Approval of Transportation Conformity Budgets for the San Joaquin 

Valley PM2.5 State Implementation Plan,” June 19, 2015; and CARB Board Resolution 15-39, “San Joaquin Valley PM2.5

State Implementation Plan,” July 23, 2015. 
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

13 

CAA section 110(k)(1)(B) requires the EPA to determine whether a SIP submission is complete 

within 60 days of receipt. This section also provides that any plan that the EPA has not affirmatively

determined to be complete or incomplete will become complete by operation of law six months after the 

date of submission. The EPA’s SIP completeness criteria are found in 40 CFR part 51, Appendix V. The 

initial SIP submission, dated June 25, 2015, became complete by operation of law on December 25, 

2015 and we find that the SIP submission pertaining to 2018 transportation conformity motor vehicle 

emission budgets, dated August 13, 2015, satisfies the completeness criteria in 40 CFR part 51, 

appendix V. 

IV. Clean Air Act Requirements for PM2.5 Serious Area Plans 

A. PM2.5 Serious Area Plan Requirements 

Upon reclassification of a Moderate nonattainment area as a Serious nonattainment area under 

subpart 4, the CAA requires the State to submit the following Serious area SIP elements:34

1. A comprehensive, accurate, current inventory of actual emissions from all sources of PM2.5 and 

PM2.5 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 PM2.5 and PM2.5 precursors shall be 

implemented no later than 4 years after the area is reclassified (CAA section 189(b)(1)(B)); 

3. A demonstration (including air quality modeling) that the plan provides for attainment as 

expeditiously as practicable but no later than December 31, 2015, or where the State is seeking 

an extension of the attainment date under section 188(e), a demonstration that attainment by 

 

34 80 FR 18528, 18531 (April 7, 2015). 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

14 

December 31, 2015 is impracticable and that the plan provides for attainment by the most 

expeditious alternative date practicable (CAA sections 188(c)(2) and 189(b)(1)(A)); 

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

5. Quantitative milestones which are to be achieved every 3 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 PM2.5

also apply to major stationary sources of PM2.5 precursors, except where the State demonstrates 

to the EPA’s satisfaction that such sources do not contribute significantly to PM2.5 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”35 thresholds from 100 tons per year (tpy) to 70 tpy (CAA section 

189(b)(3)). 

Serious area PM2.5 plans must also satisfy the requirements for Moderate area plans in CAA 

section 189(a), to the extent those requirements have not already been satisfied in the Moderate area 

plan submitted for the area; the general requirements applicable to all SIP submissions under section 110 

of the CAA; 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). 

 

35 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 PM10 (CAA section 189(b)(3)). 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

15 

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, 57 FR 

13498 (April 16, 1992) (hereafter “General Preamble”); (2) “State Implementation Plans; General 

Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990; Supplemental,” 

57 FR 18070 (April 28, 1992) (hereafter “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,” 59 FR 41998 (August 16, 1994) (hereafter “Addendum”). Additionally, in a 

proposed rule published March 23, 2015 (80 FR 15340), the EPA provided further interpretive guidance 

on the statutory SIP requirements that apply to areas designated nonattainment for the PM2.5 standards 

(hereafter “Proposed PM2.5 Implementation Rule”). We discuss these preliminary interpretations of the 

Act as appropriate in our evaluation of the 2015 PM2.5 Plan in section V of this proposed rule. 

B. Implementation of Best Available Control Measures 

Section 189(b)(1)(B) of the Act requires for any serious PM2.5 nonattainment area that the State 

submit provisions to assure that the best available control measures (BACM) for the control of PM2.5

and PM2.5 precursors shall be implemented no later than four years after the date the area is reclassified 

as a serious area. The EPA defines BACM as, 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.36 We generally consider BACM a control 

level that goes beyond existing RACM-level controls, for example by expanding the use of RACM 

 

36 Addendum at 42010, 42013. 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

16 

controls or by requiring preventative measures instead of remediation.37 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.38 

The EPA has historically provided an exemption from BACM and BACT for source categories 

that contribute only de minimis levels to ambient PM10 concentrations in a Serious nonattainment area. 

The Addendum discusses the following steps for determining BACM: 

1. Develop a detailed emission inventory of the sources of PM2.5 and PM2.5 precursors; 

2. Evaluate source category impacts; 

3. Evaluate alternative control techniques and their technological feasibility; and 

4. Evaluate the costs of control (i.e., economic feasibility).39 

 Once these analyses are complete, the State must use this information to develop enforceable 

control measures and submit them to the EPA for evaluation under CAA section 110. We use these steps 

as guidelines in our evaluation of the BACM measures and related analyses in the 2015 PM2.5 Plan. 

C. Implementation of Reasonably Available Control Measures 

When the EPA reclassifies a Moderate area to Serious under subpart 4, the requirement to 

implement reasonably available control measures (RACM) in section 189(a)(1)(C) remains. Thus, a 

Serious area PM2.5 plan must also provide for the implementation of RACM as expeditiously as 

practicable, to the extent that the RACM requirement has not been satisfied in the area’s Moderate area 

plan.40

 

37 Id. at 42011, 42013. 

38 Id. at 42009-42010. 

39 Id. at 42012-42014. 

40 EPA previously approved California’s RACM demonstration for the 1997 PM2.5 NAAQS in the SJV (76 FR 69896, 

November 9, 2011). On May 20, 2015, the Ninth Circuit Court of Appeals remanded this final rule to EPA on the grounds 
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

17 

However, the EPA does not normally conduct a separate evaluation to determine whether a 

Serious area plan’s measures also meet the RACM requirements. As explained in the Addendum, we 

interpret the BACM requirement as generally subsuming the RACM requirement – i.e., if we determine 

that the measures are indeed the “best available,” we have necessarily concluded that they are 

“reasonably available.”41 Therefore, a separate analysis to determine if the measures represent a RACM 

level of control is not necessary. A proposed approval of a Plan’s provisions concerning implementation 

of BACM is also a proposed finding that the Plan provides for the implementation of RACM. 

D. Extension of the Serious Area Attainment Date Beyond 2015 

Under section 188(e) of the Act, a state may apply to the EPA for a single extension of the 

Serious area attainment date by up to 5 years, which the EPA may grant if the State satisfies certain 

conditions. Before the EPA may extend the attainment date for a Serious area under section 188(e), the

State must: (1) apply for an extension of the attainment date beyond the statutory attainment date; (2) 

demonstrate that attainment by the statutory attainment date is impracticable; (3) have complied with all 

requirements and commitments pertaining to the area in the implementation plan; (4) demonstrate to the

satisfaction of the Administrator that the plan for the area includes the “most stringent measures” that 

are included in the implementation plan of any State or are achieved in practice in any State, and can

feasibly be implemented in the area; and (5) submit a demonstration of attainment by the most 

expeditious alternative date practicable.42

 

that the California mobile source “waiver measures” upon which the plan relied were not federally enforceable components 

of the approved SIP. Committee for a Better Arvin v. EPA, 786 F.3d 1169 (9th Cir. 2015). On November 12, 2015, the EPA 

proposed to approve the relevant waiver measures into the SIP and to thereby make them federally enforceable under the 

CAA. 80 FR 69915 (November 12, 2015). Final approval of these waiver measures would cure the deficiency in California’s 

RACM demonstration for the 1997 PM2.5 NAAQS in the SJV. 

41 Addendum at 42010. 

42 For a discussion of EPA’s interpretation of the requirements of section 188(e), see Addendum at 42002 (August 16, 1994); 

65 FR 19964 (April 13, 2000) (proposed action on PM10 Plan for Maricopa County, Arizona); 66 FR 50252 (October 2, 

2001) (proposed action on PM10 Plan for Maricopa County, Arizona); 67 FR 48718 (July 25, 2002) (final action on PM10

Plan for Maricopa County, Arizona); and Vigil v. EPA, 366 F.3d 1025, amended at 381 F.3d 826 (9th Cir. 2004) (remanding 
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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In addition to establishing these preconditions for an extension of the Serious area attainment 

date, section 188(e) provides that the EPA may consider a number of factors in determining whether to 

grant an extension and the appropriate length of time for any such extension. These factors are: (1) the 

nature and extent of nonattainment in the area, (2) the types and numbers of sources or other emitting

activities in the area (including the influence of uncontrollable natural sources and trans-boundary 

emissions from foreign countries), (3) the population exposed to concentrations in excess of the standard 

in the area, (4) the presence and concentrations of potentially toxic substances in the mix of particulate 

emissions in the area, and (5) the technological and economic feasibility of various control measures.43

Notably, neither the statutory requirements nor the discretionary factors identified in section 188(e)

include the specific ambient air quality conditions in section 188(d)(2), which must be met for an area to 

qualify for an extension of a Moderate area attainment date. 

The EPA has previously interpreted section 188(e) in approving an extension of the PM10

Serious area attainment date for the Phoenix Metropolitan area in Maricopa County, Arizona.44 We 

propose to generally follow the steps provided in that rulemaking action for addressing the statutory 

requirements for an extension of the Serious area attainment date under section 188(e) as described 

below. 

Step 1: Demonstrate that attainment by the statutory Serious area attainment date is 

impracticable. 

 

EPA action on PM10 Plan for Maricopa County, Arizona but generally upholding EPA’s interpretation of CAA section 

188(e)). 

43 CAA section 188(e). 

44 See 65 FR 19964 (April 13, 2000) (proposed action on Maricopa County Serious Area Plan, annual PM10 standard); 66 FR 

50252 (October 2, 2001) (proposed action on Maricopa County Serious Area Plan, 24-hour PM10 standard); and 67 FR 48718 

(July 25, 2002) (final action on Maricopa County Serious Area Plan). 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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Section 188(e) authorizes the EPA to grant a state request for an extension of the Serious area 

attainment date if, among other things, attainment by the date established under section 188(c) would be 

impracticable. In order to demonstrate impracticability, the plan must show that the implementation of

BACM and BACT on relevant source categories will not bring the area into attainment by the statutory 

Serious area attainment date. For the SJV, the Serious area attainment date under section 188(c)(2) is

December 31, 2015.45 BACM, including BACT, is the required level of control for serious areas that 

must be in place before the Serious area attainment date. Therefore, we interpret the Act as requiring

that a state provide for at least the implementation of BACM, including BACT, before it can claim 

impracticability of attainment by the statutory deadline. The statutory provision for demonstrating 

impracticability requires that the demonstration be based on air quality modeling.46

This interpretation parallels our interpretation of the impracticability option for Moderate PM10

nonattainment areas in section 189(a)(1)(B), under which implementation of a RACM/RACT control 

strategy, at a minimum, is a prerequisite for approval of a Moderate area plan demonstrating 

impracticability of attainment by the Moderate area attainment date.47

Step 2: Comply with all requirements and commitments in the applicable implementation plan. 

A second precondition for an extension of the Serious area attainment under section 188(e) is a 

showing that the State has complied with all requirements and commitments pertaining to that area in 

the implementation plan. We interpret this criterion to mean that the State has implemented the control 

measures and commitments in the SIP revisions it has submitted to address the applicable requirements 

 

45 Under CAA section 188(c)(2), the attainment date for a Serious area “shall be as expeditiously as practicable but no later 

than the end of the tenth calendar year beginning after the area’s designation as nonattainment....” EPA designated the SJV 

area as nonattainment for the 1997 PM2.5 standards effective April 5, 2005 (70 FR 944, 956-957, January 5, 2005). Therefore, 

the latest permissible attainment date under section 188(c)(2), for purposes of the 1997 PM2.5 standards in this area, is 

December 31, 2015. 

46 CAA section 189(b)(1)(A). 

47 General Preamble at 13544; see also 65 FR 19964, 19968 (April 13, 2000). 
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in CAA sections 172 and 189 for PM2.5 nonattainment areas. For a Serious area attainment date 

extension request being submitted simultaneously with the initial Serious area attainment plan for the

area, the EPA proposes to read section 188(e) not to require the area to have a fully approved Moderate 

area attainment plan and to allow for extension of the attainment date if the area has complied with all 

Moderate area requirements and commitments pertaining to that area in the State’s submitted Moderate 

area implementation plan. This interpretation is based on the plain language of section 188(e), which 

requires the State to comply with all requirements and commitments pertaining to the area in the 

implementation plan.48

Step 3: Demonstrate the inclusion of the most stringent measures. 

A third precondition for an extension of the Serious area attainment under section 188(e) is for 

the State to demonstrate to the satisfaction of the Administrator that the plan for the area includes the 

most stringent measures that are included in the implementation plan of any state, or are achieved in 

practice in any state, and can feasibly be implemented in the area. The EPA has interpreted the term 

“most stringent measure” (MSM) to mean the maximum degree of emission reduction that has been 

required or achieved from a source or source category in any other attainment plan or in practice in any 

other state and that can feasibly be implemented in the area seeking the extension.49 The Act does not 

specify an implementation deadline for MSM. Because the clear intent of section 188(e) is to minimize 

the length of any attainment date extension, we propose that the implementation of MSM should be as 

expeditiously as practicable. 

 

48 The Ninth Circuit Court of Appeals upheld this interpretation of section 188(e) in Vigil v. Leavitt, 366 F.3d 1025, amended 

at 381 F.3d 826 (9th Cir. 2004). 

49 65 FR 19964, 19968 (April 13, 2000); see also Addendum at 42010. 
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An MSM demonstration should follow a process similar to a BACM demonstration, but with one 

additional step, as follows: 

1. Develop a detailed emission inventory of the sources of PM2.5 and PM2.5 precursors; 

2. Evaluate source category impacts; 

3. Identify the potentially most stringent measures in other implementation plans or used in 

practice in other states for each relevant source category and, for each measure, determine 

their technological and economic feasibility in the nonattainment area; 

4. Compare the potential MSM for each relevant source category to the measures, if any, 

already adopted for that source category in the Serious nonattainment area to determine 

whether such potential MSM would further reduce emissions; and 

5. Provide for the adoption and expeditious implementation of any MSM that is more stringent 

than existing measures or, in lieu of adoption, provide a reasoned justification for rejecting 

the potential MSM (i.e., provide an explanation as to why such measures cannot feasibly be 

implemented in the area).50

 

 The level of control required under the MSM standard may depend on how well other areas have 

chosen to control their sources. If a source category has not been well controlled in other areas then

MSM could theoretically result in a low level of control. This contrasts with BACM which is 

determined independently of what other areas have done and depends only on what is the best level of 

control feasible for an area.51 On the other hand, given the strategy in the nonattainment provisions of 

the Act to offset longer attainment timeframes with more stringent emission control requirements, we 

interpret the MSM provision to assure that it results in additional controls beyond the set of measures 

 

50 65 FR 19964, 19968 (April 13, 2000); see also Proposed PM2.5 Implementation Rule at 15420 (March 23, 2015). 

51 Id. 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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adopted as BACM. Two ways to do this are (1) to require that more sources and source categories be 

subject to MSM analysis than to BACM analysis, that is, by expanding the applicability provisions in 

the MSM control requirements to cover more sources, and (2) to require reanalysis of any measures 

adopted in other areas that were rejected during the BACM analysis because they could not be 

implemented by the BACM implementation deadline to see if they are now feasible for the area given 

the longer attainment timeframe.52

 Notably, the “to the satisfaction of the Administrator” qualifier on the MSM requirement 

indicates that Congress granted the EPA considerable discretion in determining whether a plan in fact 

includes MSM, recognizing that the overall intent of section 188(e) is that we grant as short an extension 

as practicable. For this reason, the EPA will apply greater scrutiny to the evaluation of MSM for source 

categories that contribute the most to the PM2.5 problem in the SJV and less scrutiny to source categories 

that contribute little to the PM2.5 problem. 

Step 4: Demonstrate attainment by the most expeditious alternative date practicable. 

Section 189(b)(1)(A) requires that the Serious area plan for the SJV area demonstrate attainment, 

using air quality modeling, by the most expeditious date practicable after December 31, 2015. Because 

the 1997 annual and 24-hour PM2.5 standards are independent standards, section 189(b)(1)(A) requires a 

demonstration of attainment by the most expeditious date practicable for each standard.53

Evaluation of a modeled attainment demonstration consists of two parts: evaluation of the 

technical adequacy of the modeling itself and evaluation of the control measures that are relied on to

demonstrate attainment. The EPA’s determination of whether the plan provides for attainment by the 

 

52 65 FR 19964, 19968-19969. 

53 Ober v. EPA, 84 F.3d 304 (9th Cir. 1996) (noting that the CAA requires independent treatment of the annual and 24-hour 

PM10 standards in an implementation plan). 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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most expeditious date practicable depends on whether the plan provides for implementation of BACM 

and BACT no later than the statutory implementation deadline, MSM as expeditiously as practicable, 

and any other technologically and economically feasible measures that will result in attainment as 

expeditiously as practicable. 

Step 5: Apply for an attainment date extension. 

Finally, the State must apply in writing to the EPA for an extension of a Serious area attainment 

date, and this request must accompany the modeled attainment demonstration showing attainment by the 

most expeditious alternative date practicable. Additionally, the State must provide the public reasonable 

notice and opportunity for a public hearing on the attainment date extension request before submitting it 

to the EPA, in accordance with the requirements for SIP revisions in CAA section 110. 

V. Review of the San Joaquin Valley PM2.5 Serious Area Plan and Extension Application 

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] area . . . .” 

By requiring an accounting of actual emissions from all sources of the relevant pollutants in the area, 

this section provides for the base year inventory to include all emissions that contribute to the formation 

of a particular NAAQS pollutant. For the 1997 PM2.5 standards, this includes direct PM2.5 as well as the 

main chemical precursors to the formation of secondary PM2.5: NOx, sulfur dioxide (SO2), volatile 

organic compounds (VOC), and ammonia (NH3). Primary PM2.5 includes condensable and filterable 

particulate matter. 

A state must include in its SIP submission documentation explaining how the emissions data 

were calculated. In estimating mobile source emissions, a state should use the latest emissions models
This document is a prepublication version, signed by Jared Blumenfeld, Regional Administrator, EPA Region 9 on January 28, 

2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

24 

and planning assumptions available at the time the SIP is developed. States are also required to use the 

EPA’s Compilation of Air Pollutant Emission Factors (AP–42)54 road dust method for calculating reentrained road dust emissions from paved roads.55 The latest EPA-approved version of California’s 

mobile source emission factor model is EMFAC2014.56 

In addition to the base year inventory submitted to meet the requirements of CAA section 

172(c)(3), the State must also submit future “baseline inventories” for the projected attainment year and 

each reasonable further progress (RFP) milestone year, and any other year of significance for meeting 

applicable CAA requirements.57 By “baseline inventories” (also referred to as “projected baseline 

inventories”), we mean projected emissions inventories for future years that account for, among other 

things, the ongoing effects of economic growth and adopted emissions control requirements. The SIP 

should include documentation to explain how the emissions projections were calculated. 

2. Emissions Inventories in the 2015 PM2.5 Plan 

The planning inventories for direct PM2.5 and all PM2.5 precursors (NOx, SOx, VOC, and 

ammonia) for the SJV PM2.5 nonattainment area together with documentation for the inventories are 

found in SJV Appendix B of the 2015 PM2.5 Plan. Annual average inventories and winter daily average 

inventories, representing conditions in the period November through April, are provided for the base 

year of 2012 and each baseline year from 2013 to 2020. The winter daily average inventory is useful to

evaluate sources of emissions during the portion of the year when the vast majority of exceedances of 

 

54 EPA released an update to AP-42 in January 2011, which revised the equation for estimating paved road dust emissions 

based on an updated data regression that included new emission tests results. 

55 76 FR 6328 (February 4, 2011). 

56 80 FR 77337 (December 14, 2015). 

57 40 CFR 51.1007(a), 51.1008(b), and 51.1009(f); see also U.S. EPA, “Emissions Inventory Guidance for Implementation of 

Ozone [and Particulate Matter] National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations,” 

available at http://www.epa.gov/sites/production/files/2014-10/documents/2014revisedeiguidance_0.pdf. 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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the 1997 24-hour PM2.5 NAAQS occur. Baseline inventories reflect all control measures adopted prior 

to January 2012. Growth factors used to project these baseline inventories are derived from data 

obtained from a number of sources such as the California Energy Commission (CEC), the Division of 

Oil, Gas, and Geothermal Resources (DOGGR), and the California Department of Finance, as well as 

studies commissioned by the SJV’s metropolitan planning organizations.58

Each inventory includes emissions from point, area, on-road, and non-road sources. The 

inventories use EMFAC2014 for estimating on-road motor vehicle emissions.59 Re-entrained paved road 

dust emissions were calculated using the EPA’s AP-42 road dust methodology.60

Tables 1 and 2 provide a summary of the annual average and winter daily average inventories of 

direct PM2.5 and PM2.5 precursors for the base year of 2012. The District provides its reasons for 

selecting 2012 as the base year in Appendix B of the Plan.61 These inventories provide the basis for the 

control measure analysis and the RFP and attainment demonstrations in the 2015 PM2.5 Plan. 

Table 1. San Joaquin Valley Annual Average Emissions Inventory for Direct PM2.5 and PM2.5

Precursors for the 2012 Base Year (tons/day) 

Direct 

PM2.5

NOx SOx VOC Ammonia 

Stationary Sources 8.8 38.3 6.9 99.2 13.6

Area Sources 44.1 8.2 0.3 152.1 311.2

On-Road Mobile 

Sources 7.3 198.0 0.6 54.0 4.7

Off-Road Mobile 

Sources 5.9 87.7 0.2 35.3 0.0

Total 66.0 332.2 8.1 340.7 329.5

Source: 2015 PM2.5 Plan, Appendix B, Tables B-1 to B-5. 

 

58 2015 PM2.5 Plan, SJV Appendix B, pp. B-23 to B-29.

59 Id. at B-31. 

60 Id. at B-27. 

61 Id. At B-20, B-21. 
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Table 2. San Joaquin Valley Winter Daily Average Emissions Inventory for Direct PM2.5 and 

PM2.5 Precursors for the 2012 Base Year (tons/day) 

Direct 

PM2.5

NOx SOx VOC Ammonia 

Stationary Sources 8.5 34.6 6.6 98.7 13.5

Area Sources 40.7 11.7 0.5 156.5 291.8

On-Road Mobile 

Sources 7.3 204.1 0.6 55.6 4.7

Off-Road Mobile 

Sources 4.6 68.0 0.2 26.8 0.0

Total 61.0 318.5 7.9 337.5 310.0

Source: 2015 PM2.5 Plan, Appendix B, Tables B-1 to B-5. 

3. EPA’s Evaluation and Proposed Action 

The inventories in the 2015 PM2.5 Plan are based on the most current and accurate information 

available to the State and District at the time the Plan and its inventories were being developed in 2014 

and 2015, including the latest version of California’s mobile source emissions model, EMFAC2014.62

The inventories comprehensively address all source categories in the SJV and were developed consistent

with the EPA’s inventory guidance. For these reasons, we are proposing to approve the 2012 base year 

emissions inventory in the 2015 PM2.5 Plan as meeting the requirements of CAA section 172(c)(3). We 

are also proposing to find that the baseline inventories in the Plan provide an adequate basis for the

BACM, MSM, impracticability, RFP, and attainment demonstrations in the 2015 PM2.5 Plan. 

B. Adequate Monitoring Network 

We discuss the adequacy of the monitoring network in this preamble to support our finding that 

the plan appropriately evaluates the PM2.5 challenges in the San Joaquin Valley. Reliable ambient data is 

 

62 CARB submitted the EMFAC2014 model to the EPA on May 21, 2015 and EPA recently approved that model for use in 

California SIPs. 80 FR 77337 (December 14, 2015). 
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necessary to validate the base year air quality modeling which in turn is necessary to assure sound 

attainment demonstrations. 

Section 110(a)(2)(B)(i) of the CAA requires states to establish and operate air monitoring 

networks to compile data on ambient air quality for all criteria pollutants. Our regulations in 40 CFR

part 58 establish specific requirements for operating air quality surveillance networks to measure 

ambient concentrations of PM2.5, including requirements for measurement methods, network design, 

quality assurance procedures, and in the case of large urban areas, the minimum number of monitoring 

sites designated as State and Local Air Monitoring Stations (SLAMS). A good spatial distribution of 

sites, correct siting, and quality-assured and quality-controlled data are the most important factors we 

consider when evaluating the monitoring network for air quality modeling. 

Under 40 CFR part 58, states are required to submit Annual Network Plans (ANPs) for ambient 

air monitoring networks for approval by the EPA. The most recent ANP, entitled “2014 Air Monitoring 

Network Plan,” summarizes the state of the ambient air monitoring network in the San Joaquin Valley as

it operated from January 2013 through May 2014.63 During this time, there were 20 monitoring sites 

operated by either the District or CARB that collected PM2.5 data, including 14 monitors designated as 

SLAMS, ten monitors designated as special purpose monitors (SPMs), four supplemental speciation 

monitors, and eight non-regulatory monitors.64 On June 16, 2015, the EPA approved those portions of 

the State’s and District’s 2014 Air Monitoring Network Plan that pertain to the adequacy of the network 

for PM2.5 monitoring purposes.65

 

63 SJVAPCD, “2014 Air Monitoring Network Plan,” January 28, 2015. 

64 Id., Table 17, p. 25 and Table 19, p. 27. 

65 Letter dated June 16, 2015, from Meredith Kurpius, Manager, EPA Region 9, Air Quality Analysis Office, to Sheraz Gill, 

Director of Strategies and Incentives, SJVUAPCD.
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Similarly, the District’s previous ANP, entitled “Annual Air Monitoring Network Plan, June 25, 

2013,” summarizes the state of the ambient air monitoring network in the San Joaquin Valley as it 

operated from January 2012 through March 2013.66 During this time, there were 21 monitoring sites 

operated by either the District or CARB that collected PM2.5 data, including 14 monitors designated as 

SLAMS, 12 monitors designated as special purpose monitors (SPMs), two supplemental speciation 

monitors, and eight non-regulatory monitors.67 On May 8, 2014, the EPA approved those portions of the 

State’s and District’s 2014 Air Monitoring Network Plan that pertain to the adequacy of the network for 

PM2.5 monitoring purposes.68

In sum, the PM2.5 monitoring network operated by the District and CARB from January 2012 

through May 2014 is adequate to support the air quality modeling in the 2015 PM2.5 Plan. 

C. PM2.5 Precursors 

1. Requirements for the Control of PM2.5 Precursors 

The composition of PM2.5 is complex and highly variable due in part to the large contribution of 

secondary PM2.5 to total fine particle mass in most locations, and to the complexity of secondary particle 

formation processes. A large number of possible chemical reactions, often non-linear in nature, can 

convert gaseous SO2, NOx, VOC, and ammonia to PM2.5, making them precursors to PM2.5.

69 Formation 

of secondary PM2.5 may also depend on atmospheric conditions, including solar radiation, temperature, 

and relative humidity, and the interactions of precursors with preexisting particles and with cloud or fog 

droplets.70

 

66 SJVAPCD, “Annual Air Monitoring Network Plan,” June 25, 2013. 

67 SJVAPCD, “Annual Air Monitoring Network Plan,” June 25, 2013, Tables 15-17, pp. 25-32. 

68 Letter dated May 8, 2014, from Meredith Kurpius, Manager, EPA Region 9, Air Quality Analysis Office, to Sheraz Gill, 

Director of Strategies and Incentives, SJVUAPCD.

69 EPA, Air Quality Criteria for Particulate Matter (EPA/600/P-99/002aF, October 2004), Chapter 3. 

70 EPA, Regulatory Impact Analysis for the Final Revisions to the National Ambient Air Quality Standards for Particulate 

Matter (EPA/452/R-12-005, December 2012), p. 2-1. 
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The 2007 PM2.5 Implementation Rule contained rebuttable presumptions concerning the four 

PM2.5 precursors applicable to attainment plans and control measures related to those plans. See 40 CFR 

51.1002(c). Although the rule included presumptions that states should address SO2 and NOx emissions 

in their attainment plans, it also included presumptions that regulation of VOCs and ammonia was not 

necessary. Specifically, in 40 CFR 51.1002(c), the EPA provided, among other things, that a state was 

“not required to address VOC [and ammonia] as . . . PM2.5 attainment plan precursor[s] and to evaluate 

sources of VOC [and ammonia] emissions in the state for control measures,” unless the state or the EPA

provided an appropriate technical demonstration showing that emissions from sources of these pollutants 

“significantly contribute” to PM2.5 concentrations in the nonattainment area.71

In NRDC, however, the D.C. Circuit remanded the EPA’s 2007 PM2.5 Implementation Rule in its 

entirety, including the presumptions concerning VOC and ammonia in 40 CFR 51.1002.72 Although the 

court expressly declined to decide the specific challenge to these presumptions concerning precursors,73

the court cited CAA section 189(e)74 to support its observation that “[a]mmonia is a precursor to fine 

particulate matter, making it a precursor to both PM2.5 and PM10” and that “[f]or a PM10 nonattainment 

area governed by subpart 4, a precursor is presumptively regulated.”75 Consistent with the NRDC 

decision, the EPA now interprets the Act to require that under subpart 4, a state must evaluate all PM2.5

precursors for regulation unless, for any given PM2.5 precursor, it demonstrates to the Administrator’s 

satisfaction that such precursor does not contribute significantly to PM2.5 levels which exceed the 

NAAQS in the nonattainment area. 

 

71 40 CFR 51.1002(c)(3), (4). See also 2007 PM2.5 Implementation Rule, 72 FR 20586 at 20589-97 (April 25, 2007). 

72 NRDC v. EPA, 706 F.3d 428 (D.C. Cir. 2013). 

73 Id. at 437, n. 10. 

74 Section 189(e) of the CAA states that “[t]he control requirements applicable under plans in effect under this part for major 

stationary sources of PM10 shall also apply to major stationary sources of PM10 precursors, except where the Administrator 

determines that such sources do not contribute significantly to PM10 levels which exceed the standard in the area.” 

75 706 F.3d at 436, n. 7 (D.C. Cir. 2013). 
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The provisions of subpart 4 do not define the term “precursor” for purposes of PM2.5, nor do they 

explicitly require the control of any specifically identified particulate matter (PM) precursor. The 

statutory definition of “air pollutant,” 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.” CAA section 302(g). The EPA has 

identified SO2, NOx, VOC, and ammonia as precursors to the formation of PM2.5. Accordingly, the 

attainment plan requirements of subpart 4 apply to emissions of all four precursor pollutants and direct 

PM2.5 from all types of stationary, area, and mobile sources, except as otherwise provided in the Act 

(e.g., CAA section 189(e)). 

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

direct PM10 also apply to major stationary sources of PM10 precursors, except where the Administrator 

determines that such sources do not contribute significantly to PM10 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) and reasonably available control 

technology (RACT), best available control measures (BACM) and best available control technology 

(BACT), most stringent measures (MSM), and new source review (NSR)) for sources of direct PM2.5

and PM2.5 precursor emissions. 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 PM2.5 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, area, and mobile sources of PM10 precursors area-wide under CAA section 172(c)(1) 
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31 

and subpart 4,76 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 PM10 levels in the nonattainment 

area.77

We are evaluating the 2015 PM2.5 Plan in accordance with the presumption embodied within 

subpart 4 that all PM2.5 precursors must be addressed in the State’s evaluation of potential control 

measures, unless the State adequately demonstrates that emissions of a particular precursor or precursors 

do not contribute significantly to ambient PM2.5 levels that exceed the PM2.5 NAAQS in the 

nonattainment area. In reviewing any determination by the State to exclude a PM2.5 precursor from the 

required evaluation of potential control measures, we consider both the magnitude of the precursor’s 

contribution to ambient PM2.5 concentrations in the nonattainment area and the sensitivity of ambient 

PM2.5 concentrations in the area to reductions in emissions of that precursor. 

2. Evaluation of Precursors in the 2015 PM2.5 Plan 

In the 2015 PM2.5 Plan, the State and District identify NOx and SOx as the precursors that are the 

focus of its control strategy to attain the 1997 PM2.5 standards in the San Joaquin Valley.78 Although no 

technical demonstration is necessary to support a conclusion consistent with the statutory requirement to 

regulate specific PM2.5 precursors under subpart 4, the 2015 PM2.5 Plan nevertheless provides supporting 

evidence describing the effectiveness of NOx and SOx emission controls.79 By contrast, the 2015 PM2.5

Plan includes statements that further reductions in VOC and ammonia emissions would not contribute to 

 

76 General Preamble, 57 FR 13498 at 13539-42 (April 16, 1992). 

77 Courts have upheld this approach to the requirements of subpart 4 for PM10. See, e.g., Assoc. of Irritated Residents v. EPA, 

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

78 This identification is made in the 2015 PM2.5 Plan, WOEA, p. A-3. See also Chapter 2 (“PM2.5 Trends and Challenges in 

the San Joaquin Valley”), for more regarding the State and District’s analysis that NOx is a significant precursor (p. 2-8), and 

that VOC and ammonia are insignificant precursors (pp. 2-19 and 2-27, respectively). 

79 2015 PM2.5 Plan, Chapter 2, p. 2-24 and Figure 2-19, p. 2-26 (for NOx) and SJV Appendix A, p. A-47 (for SOx). 
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attainment of the 1997 PM2.5 NAAQS in the area80 and provides CARB’s and SJVUAPCD ‘s analyses 

to support these positions. 

CARB and the SJVUAPCD base these conclusions on various air quality monitoring and 

modeling studies, modeling done by CARB for the 2008 PM2.5 Plan and for the 2012 plan for attaining 

the 2006 PM2.5 standard in the SJV (“2012 PM2.5 Plan”), and other technical information. We discuss 

below the technical bases provided in the 2015 PM2.5 Plan to support these positions with respect to SO2, 

NOx, VOC, and ammonia, as well as EPA’s analyses of this information. For more detail on EPA’s 

analyses, please refer to section II of our “General Technical Support Document for EPA’s Proposed 

Rule on the 2015 PM2.5 Plan for the San Joaquin Valley for the 1997 PM2.5 NAAQS,” January 2016 

(“General TSD”). 

a. SO2

The 2015 PM2.5 Plan recognizes that emissions of SO2 contribute significantly to ambient PM2.5

levels in the San Joaquin Valley, and that ambient PM2.5 concentrations are sensitive to reductions in 

SO2. It shows the measured contribution of SO2 emissions to ambient PM2.5 concentrations in pie charts 

portraying the contribution of various pollutant species. For 2010-2012, depending on location, the 

three-year annual average PM2.5 chemical composition was 11-14% ammonium sulfate, while for 2011-

2013, the three-year average high day PM2.5 chemical composition was 4-6% ammonium sulfate.81 The 

Plan further describes the formation of ammonium sulfate as SOx-limited, given that ammonia is about 

80 times more abundant than SOx for both annual and winter average emission inventories.82 The 

 

80 2015 PM2.5 Plan, Chapter 2, p. 2-19. 

81 2015 PM2.5 Plan, WOEA, Figures 6 and 7, respectively, p. A-16. See also 2015 PM2.5 Plan, Appendix F, Figure F-2, pp. F8 to F-9, which shows how ammonium sulfate has decreased slightly at three of the four monitoring sites from the 2004-2006 

period to the 2011-2013 period. 

82 2015 PM2.5 Plan, WOEA, p. A-41. This is on a molar or mass-equivalent basis: there are 80 times as many ammonia 

molecules emitted as would be required to combine with all the emitted SO2 molecules to form ammonium sulfate, 

accounting for the emissions in tons per day, the molecular masses, and the chemical formula for ammonium sulfate. 
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33 

ammonium sulfate contribution levels are substantial, particularly with respect to the annual average 

concentration, although smaller than the contributions of some other PM2.5 components (i.e., ammonium 

nitrate and organic matter). 

Ambient PM2.5 sensitivity to reductions of SO2 emissions is also presented in the 2015 PM2.5

Plan in the form of modeling results. The results from the sensitivity modeling are cited and discussed 

below in the NOx subsection. The 2015 PM2.5 Plan infers from the modeling that there is an ambient 

PM2.5 concentration decrease of 0.08 μg/m3 at the projected design value monitoring site in 2019 

(Bakersfield-California) per ton of SO2 reduction in the SJV area.83 While the 2019 winter average 

emissions inventory for SOx (7.6 tpd) is much smaller than that for NOx (208.0 tpd) in the SJV, the 0.08 

μg/m3 PM2.5 decrease per ton of emissions reduction is the same for SO2 as it is for NOx.

84 Even though 

the relatively small SO2 contribution to ambient PM2.5 concentrations may leave less scope for 

reductions, the sensitivity of ambient PM2.5 to SO2 emission reductions indicates that SO2 emissions 

contribute significantly to PM2.5 levels above the standards in the SJV area. 

Based on the technical analyses provided in the Plan, the EPA agrees with the State’s and 

District’s conclusion that SO2 controls must be included in the evaluation of potential control measures 

for the 1997 PM2.5 standards in the SJV, consistent with the requirements of subpart 4. 

b. NOx 

The 2015 PM2.5 Plan recognizes that emissions of NOx contribute significantly to ambient PM2.5

levels in the San Joaquin Valley, and that ambient PM2.5 concentrations are sensitive to reductions in 

NOx. The Plan discusses NOx in conjunction with ammonia, because these precursors react together to 

 

83 2015 PM2.5 Plan, WOEA, p. A-27. 

84 Id. See also, 2015 PM2.5 Plan, Appendix B, pp. B-8 and B-11. 
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create ammonium nitrate, the largest component of ambient PM2.5 particles by species in the SJV.85 The 

chemical products of ammonia and NOx (ammonium and nitrate) combine in a 1:1 molecular ratio, but 

as discussed below, this ratio does not mean that emissions controls for the two precursor pollutants 

would be equally effective at reducing ambient PM2.5. The Plan provides several forms of evidence to 

indicate that reductions in NOx emissions are effective in reducing PM2.5 concentrations exceeding the 

standard, and also that they are more effective than reductions in ammonia emissions. The evidence 

includes speciated data from ambient PM2.5 monitors, model simulations of NOx emission reductions, 

historical trends, and the relative amounts of NOx and ammonia.

The 2015 PM2.5 Plan indicates that the ambient contribution of NOx to PM2.5 levels in the SJV is 

substantial. According to available speciation data, ammonium nitrate is the largest chemical component 

of ambient PM2.5 in the SJV, as measured in the southern (Bakersfield), central (Fresno), and northern 

(Modesto) portions of San Joaquin Valley. It comprises 38-41% of the 2010-2012 average annual PM2.5

concentrations and 53-64% of the 2011-2013 average peak 24-hour PM2.5 concentrations, the highest 

percentages being observed in Bakersfield.86 Using the 2011-2013 annual average PM2.5 design value of 

17.3 μg/m3 at the Bakersfield-Planz site,87 the ammonium nitrate concentration is approximately 7.1 

μg/m3. If only nitrate itself is considered (i.e., the nitrate part of the ammonium nitrate molecules), the 

 

85 2015 PM2.5 Plan, WOEA, Figures 6 and 7, p. A-16. 

86 Id. 

87 2015 PM2.5 Plan, Appendix A, p. A-9. The design value for the Bakersfield-Planz site for 2011-2013 is given as a rounded 

value of 17.0 μg/m3 in Table A-6 in Appendix A of the Plan. For greater precision in estimating species contributions, we 

have used the unrounded value of 17.3 μg/m3

, which we calculated as the average of the 98th percentiles values for each year 

(14.5, 14.7, and 22.8) as listed in Appendix A, Table A-5. We used the Bakersfield-Planz site (the second highest 2011-2013 

annual average) in lieu of the Madera-City site (highest average), consistent with the Plan’s weight of evidence for the 

attainment demonstration. Similarly consistent with the attainment demonstration, this 17.3 μg/m3 value excludes the data 

from May 5, 2013 for Bakersfield-Planz. Section V.E.5 of this proposed rule has further discussion of these matters. For 

calculating the ammonium nitrate concentration, we used the 41% value from the Bakersfield pie chart in the 2015 PM2.5

Plan, WOEA, Figure 6, p. A-16. 
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contribution of NOx represents 5.5 μg/m3, which is approximately 31.8% of the annual average PM2.5

concentration.88

Similarly, using the 2011-2013 24-hour PM2.5 design value of 64.6 μg/m3

 at the BakersfieldCalifornia site,89 the 24-hour average ammonium nitrate concentration on peak PM2.5 days is 

approximately 41.3 μg/m3. If only nitrate itself is considered (i.e., the nitrate part of the ammonium 

nitrate molecules), the contribution of NOx represents 32.0 μg/m3

, which is approximately 49.6% of the 

average peak 24-hour PM2.5 concentration. Whether considered as ammonium nitrate or simply as 

nitrate, NOx is clearly a significant contributor to ambient PM2.5 levels above the standard in the SJV. 

In addition to this evidence concerning the contribution of NOx to PM2.5 concentrations, the 2015 

PM2.5 Plan provides evidence that ambient PM2.5 concentrations are sensitive to NOx reductions (i.e., 

nitrate PM2.5 concentrations decrease when NOx emissions are reduced). The evidence is from modeling, 

historical trends, and relative proportions of NOx and ammonia. The 2015 PM2.5 Plan provides evidence 

from past and current photochemical modeling simulations that ambient ammonium nitrate is sensitive 

to NOx reductions. The Plan describes past modeling studies that were documented in academic 

journals.90 In the various studies, when NOx emissions were reduced by 50%, ambient ammonium 

nitrate decreased by 25-50%, depending on the episode modeled and the geographic location.91 In 

 

88 The nitrate fraction of ammonia nitrate (5.5 μg/m3

) is calculated as molecular weight of nitrate (62) divided by the 

molecular weight of ammonium nitrate (80) and equals 77.5 percent. 

89 2015 PM2.5 Plan, Appendix A, p. A-8. The design value for Bakersfield-California (the high site for monitors with 

complete data for the three years) for 2011-2013 is given as a rounded value of 65 μg/m3 in Table A-4 in Appendix A of the 

Plan. For greater precision in estimating species contributions, we have used the unrounded value of 64.6 μg/m3, which we 

calculated as the average of the 98th percentiles values for each year (65.5, 56.4, and 71.8) as listed in Table A-3. For 

calculating the ammonium nitrate concentration, we used the 64% value from the Bakersfield pie chart in the 2015 PM2.5

Plan, WOEA, Figure 7, p. A-16. 

90 The academic journal papers are described in 2015 PM2.5 Plan, WOEA, Section 5 (“Secondary Ammonium Nitrate

Formation”), pp. A-23-A-29. 

91 Chen, J., Lu, J., Avise, J.C., DaMassa, J.A., Kleeman, M.J., Kaduwela, A.P., 2014, Seasonal Modeling of PM2.5 in 

California’s San Joaquin Valley, Atmospheric Environment, 92, 182-190, doi:10.1016/j.atmosenv.2014.04.030. Kleeman, 

M.J., Ying, Q., and Kaduwela, A., Control strategies for the reduction of airborne particulate nitrate in California's San 

Joaquin Valley, Atmospheric Environment, 2005, 39, 5325-5341. Liang, J., Gürer, K., Allen, P.D., Zhang, K.M., Ying, Q., 
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36 

addition, modeling for the 2012 PM2.5 Plan for the 2006 24-hour PM2.5 NAAQS, whose results were 

relied on for the 2015 PM2.5 Plan, also shows substantial sensitivity of ambient PM2.5 concentrations to 

reductions in NOx emissions. The State modeled the effect of a 25% reduction in NOx emissions on 

ambient 24-hour PM2.5 concentrations in 2019 and combined this with the emission mass (tons per day) 

to determine that the PM2.5 concentrations would be reduced by 0.08 μg/m3 at the BakersfieldCalifornia site (the design value site for 2019) and decreases of a similar order of magnitude (i.e., 0.03 to 

0.09 μg/m3) at other monitors in the SJV.92

The 2015 PM2.5 Plan provides additional (non-modeling) evidence on the effectiveness of NOx

reductions. The historical downward trends of NOx emissions and of ambient nitrate concentrations are 

discussed in Chapter 2 and the weight of evidence analysis (WOEA) of the Plan.93 Annual average NOx

emissions levels are plotted against ammonium nitrate concentrations at Bakersfield and Fresno, and in

each case have decreased by about 35-40% from 2004 to 2012.94 This shows that NOx emissions and 

ammonium nitrate concentrations are correlated with one another. The conclusion that PM2.5 nitrate 

concentrations are more limited by NOx emissions than by ammonia emissions is strengthened by the 

fact that this reduction in ambient ammonium nitrate occurred despite an increase in emissions of 

ammonia, the other precursor to ammonium nitrate, during the same period.95 

 

Kleeman, M., Wexler, A., and Kaduwela, A., 2006, A photochemical model investigation of an extended winter PM episode 

observed in Central California: Model Performance Evaluation, Proceedings of the 5th Annual CMAQ Models-3 User’s 

Conference, Chapel Hill, NC. Livingstone, P.L. et. al., 2009, “Simulating PM Concentrations During a Winter Episode in a 

Subtropical Valley and Sensitivity Simulations and Evaluation methods”, Atmospheric Environment, 43: 5971-5977. 

doi:10.1016/j.atmosenv.2009.07.033. Pun, B.K., Balmori R.T.F, and Seigneur, C., 2009, Modeling wintertime particulate 

matter formation in Central California, Atmospheric Environment, 43, 402-409. Different models and emission inventories in 

these studies conducted over the years also contribute to the variation in results. 

92 2015 PM2.5 Plan, WOEA, Table B-2 (“Modeled PM2.5 air quality benefit per ton of valley-wide precursor emission 

reductions”), p. A-27. 

93 2015 PM2.5 Plan, Chapter 2, pp. 2-8 and 2-9; and CARB’s Staff Report, Appendix A (i.e., WOEA), pp. A-60 to A-61. 

94 2015 PM2.5 Plan, Chapter 2, Figure 2-19, p. 2-26; 2015 PM2.5 Plan, CARB Staff Report, pp. 5-6; and WOEA, Figure 44, p. 

A-60. 

95 2015 PM2.5 Plan, Chapter 2, p. 2-24. 
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The 2015 PM2.5 Plan further describes the effectiveness of NOx controls by characterizing it as 

the “limiting precursor” in ammonium nitrate formation, based on the relative amounts of NOx and 

ammonia. Based on monitored concentrations and the emissions inventory, CARB and the SJVUAPCD 

conclude that NOx is the limiting precursor and briefly illustrates this concept in its WOEA.96 One 

molecule each of NOx and ammonia is required to form each molecule of ammonium nitrate. If NOx is 

in short supply relative to ammonia, then NOx is the limiting factor in ammonium nitrate formation.97

 

The WOEA analysis includes plots98 of ammonia and nitric acid (which contains nitrate) 

concentrations at two monitoring sites in the SJV (Angiola, a rural site, and Fresno, an urban site) that 

were measured during the winter 2000-2001 CRPAQS99 study and reported in Lurmann et al. (2006).100

CARB notes that in this study, ammonia concentrations are at least an order of magnitude larger than 

those of nitrate and notes Lurmann et al.’s conclusion that NOx is the limiting precursor. CARB and the 

SJVUAPCD did not, however, present more current information about ammonia concentrations. 

The WOEA also considers emissions inventories to support the argument that NOx is the limiting 

precursor. The WOEA normalized NOx emissions using the relative molecular weights of NOx and 

ammonia, in order to reflect the number of molecules of each available to react with each other.101 In 

2012, the normalized amount of NOx available was 37-38% of the amount of ammonia for both annual 

and winter averages, while it is projected to be 21% of the amount of ammonia in 2020. This shows the 

 

96 2015 PM2.5 Plan, WOEA, section 5.b, pp. A-18 to A-19. See also 2015 PM2.5 Plan, Chapter 2, section 2.6, pp. 2-18 to 2-

27. 

97 As noted below in the ammonia subsection, the “limiting precursor” concept is not absolute, and must be used with 

caution. However, for NOx it does support evidence from the modeling results that NOx significantly contributes to 

exceedances of the 1997 PM2.5 NAAQS. 

98 2015 PM2.5 Plan, WOEA, Figures 11 and 12, pp. A-21 to A-22. 

99 CRPAQS is the California Regional Particulate Air Quality Study. More information is available about CRPAQS at 

http://www.arb.ca.gov/airways/ccaqs.htm. 

100 Lurmann, F.W., Brown, S.G., McCarthy, M.C., and Roberts, P.T., December 2006, Processes Influencing Secondary 

Aerosol Formation in the San Joaquin Valley during Winter, Journal of Air and Waste Management Association, 56, 1679-

1693. 

101 WOEA, Table 1, p. A-20. 
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38 

scarcity of NOx relative to ammonia and implies that NOx is the limiting precursor in the formation of 

ammonium nitrate.

Based on the range of technical analyses provided in the Plan and other information available to 

the EPA, we agree with the State’s and District’s conclusion that NOx controls must be included in the 

evaluation of potential control measures for the 1997 PM2.5 standards in the SJV, consistent with the 

requirements of subpart 4. 

c. Ammonia 

The 2015 PM2.5 Plan states that, based on modeling, emissions inventory, and monitoring 

studies, “[b]ecause of [the] regional surplus in ammonia, even substantial ammonia emissions reductions 

yield a relatively small reduction in nitrate”102 and “[a]mmonia emission reductions are approximately 

an order of magnitude less effective” than NOx emission reductions in reducing ambient PM2.5

concentrations.103 To support this finding, CARB and the SJVUAPCD discuss the ambient contribution 

of ammonia to measured PM2.5 levels in the SJV and the sensitivity of ambient PM2.5 to ammonia 

reductions. The latter includes discussion of the relative abundance of NOx and ammonia, and of 

modeled simulations of further reductions in ammonia emissions. 

The Plan indicates that ammonia contributes to ambient concentrations of PM2.5, in the form of 

ammonium nitrate and ammonium sulfate. As noted above in our discussion of NOx, ammonium nitrate 

comprises 38-41% of the 2010-2012 average annual PM2.5 concentrations and 53-64% of the 2011-2013 

average peak 24-hour PM2.5 concentrations, the highest percentages being observed in Bakersfield.104

Ammonium sulfate contributes an additional 11-14% of the 2010-2012 average annual PM2.5

 

102 2015 PM2.5 Plan, Chapter 2, p. 2-19. 

103 WOEA, p. A-29. 

104 2015 PM2.5 Plan, WOEA, Figures 6 and 7, p. A-16. 
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concentrations and 4-6% of the 2011-2013 average peak 24-hour PM2.5 concentrations, with the highest 

percentages similarly being observed in Bakersfield.

105

Using the highest 2011-2013 annual average PM2.5 design value of 17.3 μg/m3

 at the 

Bakersfield-Planz site, the ammonium nitrate concentration is approximately 7.1 μg/m3 and the 

ammonium sulfate concentration is approximately 2.4 μg/m3.

106 If only ammonium is considered (i.e., 

the ammonium part of the ammonium nitrate and ammonium sulfate molecules), the contribution of 

ammonium represents 2.3 μg/m3, or 13.0% of the annual average PM2.5 concentration.107

Similarly, using the 2011-2013 24-hour PM2.5 design value of 64.6 μg/m3

 at the BakersfieldCalifornia site, the 24-hour average ammonium nitrate concentration on peak PM2.5 days is 

approximately 41.3 μg/m3 and the ammonium sulfate concentration is approximately 3.9 μg/m3.

108 If 

only ammonium itself is considered (i.e., the ammonium part of the ammonium nitrate and ammonium 

sulfate molecules), the contribution of ammonium represents 10.4 μg/m3

, which is approximately 16.0%

of the average peak 24-hour PM2.5 concentration.109

Ammonia emissions are essential to the formation of both of these components of the ambient 

particulate matter, and the EPA finds that these levels of contribution are a substantial fraction of the 

SJV’s 2011-2013 annual average design value of 17.3 μg/m3, as measured at the Bakersfield-Planz site, 

 

105 Id. 

106 See n. 87 supra. In addition, for calculating the ammonium sulfate concentration, we used the 14% ammonium sulfate 

values from the Bakersfield pie chart in the 2015 PM2.5 Plan, WOEA, Figure 6, p. A-16. 

107 The ammonium fraction of ammonium nitrate (1.6 μg/m3

) is calculated as the molecular weight of ammonium (18) 

divided by the molecular weight of ammonium nitrate (80), which is 22.5 percent of the mass. The ammonium fraction of 

ammonium sulfate (0.7 μg/m3) is calculated as the molecular weight of the two ammonium molecules (36) divided by the 

molecular weight of ammonium sulfate (132), which is 27.3 percent of the mass.

108 See n. 89 supra. In addition, for calculating the ammonium sulfate concentration, we used the 6% ammonium sulfate 

values from the Bakersfield pie chart in the 2015 PM2.5 Plan, WOEA, Figure 6, p. A-16. 

109 The ammonium fraction of ammonium nitrate (9.3 μg/m3

) is calculated as the molecular weight of ammonium (18) 

divided by the molecular weight of ammonium nitrate (80), which is 22.5 percent of the mass. The ammonium fraction of 

ammonium sulfate (1.1 μg/m3) is calculated as the molecular weight of the two ammonium molecules (36) divided by the 

molecular weight of ammonium sulfate (132), which is 27.3 percent of the mass.
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and the 24-hour design value of 64.6 μg/m3, as measured at the Bakersfield-California site. This is 

evidence that emissions of ammonia contribute significantly to ambient PM2.5 concentrations that exceed 

the 1997 PM2.5 NAAQS in the SJV. 

Next we examined information in the 2015 PM2.5 Plan regarding the sensitivity of ambient PM2.5

levels in the SJV to potential ammonia emission control. On this issue there is conflicting evidence. 

Based on evidence that ammonia appears not to be the limiting precursor for ammonium nitrate 

formation and that modeled ammonia reductions are ineffective relative to NOx reductions,110 CARB 

and the SJVUAPCD conclude that controls for ammonia are not warranted. However, the EPA’s own 

evaluation of the modeling indicates that ammonia controls can be effective at reducing ambient PM2.5 in 

some locations and can be more effective at certain times of year. 

CARB and the SJVUAPCD ’s evidence discussed above to support the argument that NOx is the 

limiting precursor for ammonia nitrate formation is also presented as evidence that ammonia is not the 

limiting precursor, and thus to argue that ambient PM2.5 levels would not be sensitive to ammonia 

reductions.111 In the Plan, CARB and the SJVUAPCD state that there is both an abundance of ambient 

ammonia relative to ambient nitrate, and an abundance of ammonia emissions relative to NOx emissions. 

CARB and the SJVUAPCD also indicate that there is an abundance of gaseous ammonia relative to 

particulate ammonium at multiple locations during the 2000-2001 winter episode in the CRPAQS 

study,112 so that even under conditions favorable to ammonium nitrate formation, a substantial amount 

of unreacted ammonia remains.113 Based on these multiple pieces of evidence on the abundance of 

ammonia, CARB and the SJVUAPCD conclude that ammonia is not the limiting factor for ammonium 

 

110 2015 PM2.5 Plan, Chapter 2, Section 2.6.2, pp. 2-21 to 2-27 and WOEA, pp. A-23 to A-29. 

111 WOEA, pp. A-18 to A-22. 

112 WOEA, pp. A-22 and Figure 13, p. A-23. 

113 As noted above, NOx emissions have been decreasing and ammonia emissions increasing, so under the State’s reasoning, 

this relationship would be expected to continue. 
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nitrate formation and, thus, that reducing ammonia emissions would not reduce ambient PM2.5 in the 

SJV. 

CARB and the SJVUAPCD also considered air quality modeling analyses to evaluate the 

effectiveness of reducing ammonia as compared to other precursors, and to PM2.5 decreases needed for 

attainment. Based on modeling a 25% reduction in ammonia emissions, holding direct PM2.5 and other 

precursor emissions constant, the Plan states that per ton per day of ammonia emissions reduction, there 

would be a 0.005 to 0.010 μg/m3 decrease in ambient PM2.5 concentrations across the Valley, including 

a 0.008 μg/m3

 effect at the Bakersfield-California site.114 By comparing these sensitivities to the effect 

of a 25% reduction of NOx emissions, the Plan states that, on a per ton basis, reducing ammonia is only 

about 10% as effective as reducing NOx.

115 Thus, based on this air quality modeling, CARB and the 

SJVUAPCD conclude that additional ammonia control is considerably less effective than NOx control. 

The State and District assume in the 2015 PM2.5 Plan that additional ammonia control, as 

modeled, would provide limited benefit for attainment planning purposes. They also conclude, based 

upon the various forms of information and analyses described above, that ammonia emission reductions 

are much less effective than direct PM2.5 or NOx emission reductions, and thus argue that “[a]mmonia is 

not a significant precursor to PM2.5 values in the Valley.”116 

The EPA finds the modeling and other analyses presented and referred to in the 2015 PM2.5 Plan 

to be credible, but the modeling analyses nonetheless show that additional reductions in ammonia may 

reduce ambient PM2.5 levels to varying degrees. In the various studies, when ammonia emissions were 

reduced by up to 50%, ambient ammonium nitrate decreased by a range of approximately 5-25%, 

 

114 WOEA, Table 2, p. A-27. 

115 2015 PM2.5 Plan, Chapter 2, p. 27. 

116 2015 PM2.5 Plan, Chapter 2, p. 2-27. 
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depending on the episode modeled and the geographic location evaluated.117 Modeling conducted by 

ARB staff for the 2012 PM2.5 Plan for attaining the 2006 24-hour PM2.5 NAAQS indicated that for 

emissions reduction within Kern County, a one ton per day decrease in ammonia would lead to a 0.02 

μg/m3 improvement in the PM2.5 24-hour design value.118 If this rate were to remain constant as 

ammonia emissions decrease, and if this same sensitivity applied to valley-wide reductions, it would 

mean that a 50% reduction in the ammonia emissions inventory (estimated in the 2015 PM2.5 Plan at 

329.5 tpd annual average in 2012) would be expected to reduce 24-hour PM2.5 concentrations by more 

than 3 μg/m3

, an amount that the EPA would not consider insignificant. 

The percentages for ammonia benefits are generally smaller than those for NOx reductions, but a 

range of modeling results show that reductions in ammonia emissions under certain circumstances can 

effectively help to reduce ambient PM2.5. The fact that all the modeling studies find at least some benefit 

from ammonia control shows that the concept of NOx as a “limiting precursor” in the formation of 

ammonium nitrate particles discussed above is not absolute. In addition, the test for determining whether 

emission reduction measures for a particular precursor must be evaluated for purposes of timely 

attainment should not be based exclusively on the control effectiveness of the precursor relative to other 

precursors, but must also consider whether emissions of the precursor “contribute significantly” to 

ambient PM2.5 levels which exceed the PM2.5 standards in the nonattainment area. In other words, the 

fact that control of NOx may be more important than the control of ammonia in relative terms does not 

mean that a state should not evaluate regulations for both as part of a comprehensive plan to attain the 

PM2.5 NAAQS, and to do so expeditiously as required by the CAA. 

 

117 WOEA, pp. A-24 to A-25. 

118 WOEA, p. A-29. 
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Taking into consideration a number of factors, the EPA does not agree with the conclusion in the 

Plan that the more than 100,000 annual tons of ammonia emissions from sources in the SJV area do not 

contribute significantly to PM2.5 levels exceeding the 1997 PM2.5 NAAQS. First, the information 

provided by the State and District in the Plan shows that ammonia contributes to a large fraction of 

measured PM2.5 concentrations in the SJV area, in the form of ammonium nitrate and, to a lesser extent, 

ammonium sulfate. Based on data presented in the 2015 PM2.5 Plan, ammonia emissions, in the form of 

ammonium, are responsible for approximately 13% of the annual average concentration and 16% of the 

24-hour average at the design value site for the San Joaquin Valley. 

Second, modeled evidence submitted by the State and studies available to the EPA indicate that 

although ammonia control is less effective at reducing PM2.5 concentrations compared to NOx control, 

reducing ammonia emissions in the SJV would reduce PM2.5 by varying amounts throughout the 

nonattainment area. Studies indicate that reducing ammonia does not have a uniform effect across a 

large nonattainment area during all times of the year; ammonia reductions can be more effective at 

reducing PM2.5 concentrations in specific locations during certain times of the year. Reductions in 

ammonia in conjunction with reductions of direct PM2.5, SO2, and NOx would help to provide for 

attainment of the PM2.5 NAAQS in the SJV area. 

Finally, despite the fact that a broad range of emission reduction measures have been 

implemented to reduce emissions of direct PM2.5 and PM2.5 precursors, the Plan also indicates that 

attainment by the statutory attainment date is impracticable. This underscores the continuing severity of 

the PM2.5 nonattainment problem in the SJV and the need for a robust assessment of potential control 

measures (e.g., BACM and MSM) for direct PM2.5 and PM2.5 precursors, including potential ammonia 

control measures which may be effective in reducing ambient PM2.5 concentrations. 
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Given the severity of the PM2.5 nonattainment problem in the SJV, the high degree to which 

controls have already been applied to the emission of PM2.5 and its precursor pollutants, the 

demonstration that attainment in the SJV by 2015 is impracticable, and the documentation in the 2015 

PM2.5 Plan showing that ammonia emissions are responsible for more than 2 μg/m3 of the annual 

average PM2.5 concentration at the Bakersfield-Planz site, and for more than 10 μg/m3 of the peak day 

24-hour average PM2.5 concentration at the Bakersfield-California site, the EPA does not agree at this 

time with the conclusion in the Plan that ammonia emissions do not contribute significantly to PM2.5

levels exceeding the PM2.5 standards in the SJV. 

Although the Plan states that ammonia is not a significant precursor to ambient PM2.5 levels, and 

that additional controls for ammonia are not necessary to attain the PM2.5 standards in the SJV, the Plan 

nonetheless provides an evaluation of control measures currently implemented in the SJV that reduce 

ammonia emissions and other potential ammonia control measures. We discuss the State’s ammonia 

control evaluation in section V.D. of this proposed rule. 

d. VOC 

The 2015 PM2.5 Plan states that VOCs are not a significant precursor to ambient PM2.5 levels in 

the San Joaquin Valley and that further reductions in VOC emissions would not contribute to PM2.5

attainment. To support this finding, CARB and the SJVUAPCD discuss the ambient contribution of 

VOC to measured PM2.5 levels in the SJV, the indirect role of VOC in ammonium nitrate formation, and 

modeled simulations of further reductions in VOC emissions. 

There are two routes by which VOC can contribute to ambient PM2.5. The first is through various 

chemical reactions leading to the formation of Secondary Organic Aerosols (SOA). The second is 

through photochemical reactions that create oxidants such as ozone and the hydroxyl radical (OH), 

which in turn oxidize NOx emissions to nitrate or SOx emissions to sulfate, leading to the formation of 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

45 

particulate ammonium nitrate or particulate ammonium sulfate. Chapter 2 of the 2015 PM2.5 Plan 

discusses both roles of VOC in PM2.5 formation,119 as does the Plan’s weight of evidence analysis.120

For the direct contribution of VOC to PM2.5, the 2015 PM2.5 Plan states that modeling for annual 

average PM2.5 for the 2008 PM2.5 Plan found that anthropogenic SOA were about 3-5% of total organic 

aerosol, and that SOA were mainly formed during the summer from non-anthropogenic sources.121 The 

SJVUAPCD states that the winter anthropogenic contribution that is of interest for the 1997 24-hour 

PM2.5 NAAQS would necessarily be lower because less SOA forms at winter temperatures, which are 

lower than temperatures for the annual average. CARB and the SJVUAPCD also cite a study by Chen et 

al.122 for the winter 2000-2001 CRPAQS episode. This study found that the SOA portion of total organic 

aerosol had a maximum value of 4.26 μg/m3 with concentrations at Bakersfield of 2.28 μg/m3 and at 

Fresno of 2.46 μg/m3

, which represent 4% and 6% of the total organic aerosol at those locations. These 

locations typically represent the highest PM2.5 concentrations for the southern and central portions of the 

San Joaquin Valley. 

Applying this roughly 5% SOA proportion to the organic carbon portion of the measured 2011-

2013 peak day 24-hour average PM2.5 composition shows that, by mass, SOA is about 0.9% of total 

ambient PM2.5 at Bakersfield-California and 1.5% of ambient PM2.5 at Fresno.123 The EPA notes that 

because anthropogenic SOA is only a portion of the total SOA, the portion due to controllable 

 

119 2015 PM2.5 Plan, Chapter 2, pp. 2-20 to 2-21. 

120 WOEA, section 5.d (“Role of VOC in ammonium nitrate formation”), pp. A-30 to A-39, and section 6 (“Secondary 

Organic Aerosol Formation”), pp. A-39 to A-40. 

121 2015 PM2.5 Plan, Chapter 2, p. 2-20. 

122 Chen, J., Ying, Q., and Kleeman, M.J., 2010, Source apportionment of wintertime secondary organic aerosol during the 

California regional PM10/PM2.5 air quality study, Atmospheric Environment, 44(10), 1331-1340. 

123 The contribution of Organic Matter to 2011-2013 peak day 24-hour PM2.5 levels was 18 percent at Bakersfield and 30 

percent at Fresno (see WOEA, Figure 7, p. A-16). Five percent of these proportions gives 0.90 percent SOA at Bakersfield 

and 1.5 percent SOA at Fresno. As a fraction of the 2013 design values of 64.6 μg/m3 at Bakersfield-California and 63.5 

μg/m3 at Fresno-Winery, these percentages give SOA contributions of 0.58 μg/m3 at Bakersfield-California and 0.95 μg/m3 at 

Fresno-Winery. 
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anthropogenic sources would be even less. CARB and the SJVUAPCD conclude that these modeling 

studies show that SOA is not a substantial component of peak day (i.e., winter) 24-hour ambient PM2.5

concentrations in the SJV and that the potential for reducing ambient PM2.5 through VOC emission 

reductions is very limited. We do not have comparable information at this time to evaluate whether or 

not SOA is a substantial component of annual average PM2.5 concentrations. 

For the indirect contribution of VOC to PM2.5, nitrate formation via daytime photochemistry, 

CARB and the SJVUAPCD assert that this route is also not a substantial contributor, based on modeled 

sensitivity to VOC reductions. For one such study there were relatively low modeled concentrations of 

ozone, which did not appear consistent with nitrate formation via daytime oxidant (ozone) 

photochemistry, which would be expected to have elevated ozone levels.124 The Plan reviews essentially 

the same studies that the State relied on in the 2008 PM2.5 Plan for attainment of the 1997 PM2.5

standards,125 except for one additional 2014 study by Chen et. al.126 The EPA’s review of these studies 

and of the 2008 PM2.5 Plan’s examination of the studies is covered in the technical support document 

(TSD) for the EPA’s final action on the 2008 PM2.5 Plan (“2008 PM2.5 Plan TSD”).127 The 2014 Chen et. 

al. paper presented results of modeling the 1st and 4th quarters of 2007 using the CMAQ model (the 

same period and model that was used for the 2008 PM2.5 Plan), and also of modeling the winter 2000 

CRPAQS episode using the UCD/CIT (University of California, Davis/California Institute of 

Technology) model. The paper explored the sensitivity of PM2.5 to reductions of the various precursors. 

The CMAQ modeling showed that reducing anthropogenic VOC actually increases PM2.5 design values, 

 

124 Pun, B.K., Balmori R.T.F, and Seigneur, C., 2009, Modeling Wintertime Particulate Matter Formation in Central 

Californiaǁ, Atmospheric Environment, 43: 402-409. doi: 10.1016/j.atmosenv.2008.08.040 

125 2015 PM2.5 Plan, Chapter 2, pp. 2-20 to 2-21; WOEA, p. A-3, and section 5.d, pp. A-30 to A-39. 

126 Chen, J., Lu, J., Avise, J.C., DaMassa, J.A., Kleeman, M.J., Kaduwela, A.P., 2014, Seasonal Modeling of PM2.5 in 

California’s San Joaquin Valley, Atmospheric Environment, 92, 182-190, doi:10.1016/j.atmosenv.2014.04.030. 

127 EPA Region 9, “Technical Support Document and Responses to Comments Final Rule on the San Joaquin Valley 2008 

PM2.5 State Implementation Plan,” September 30, 2011, section II.C. 
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while the UCD/CIT modeling showed that is has a negligible effect. NOx vs. VOC isopleth diagrams 

from the paper are reproduced in the 2015 PM2.5 Plan, and illustrate these effects.128

The findings from those reviews remain the same for the current Plan: past modeling studies 

vary on whether controlling VOC reduces PM2.5, but the most reliable ones show VOC control has little 

benefit, or even a disbenefit. As detailed in the EPA’s 2008 PM2.5 Plan TSD and in the Plan’s WOEA,129

the studies for which VOC control showed a benefit at some times and places are less reliable because 

they used unrealistic emissions levels, unrealistic control scenarios, or the effect occurred at PM2.5

concentrations no longer reached in the SJV. The WOEA also suggests that, in this context of indirect

PM2.5 formation from VOC, the model boundary conditions have sufficient ozone flowing in from 

outside the SJV area,130 implying that VOC reductions would have little effect on ambient PM2.5 levels 

exceeding the standard in the SJV. 

The overall conclusion is that the effect of reducing VOC emissions is somewhat uncertain, but 

in general produces little benefit or even a disbenefit in PM2.5 concentrations. 

The modeling for the prior 2012 PM2.5 Plan, which indicates a disbenefit from controlling VOC 

at important geographic locations, adds to the evidence from past studies, and is incorporated into the 

2015 PM2.5 Plan. This is shown by negative PM2.5 sensitivities (that is, decreased VOC emissions result 

in increased PM2.5 levels) for multiple locations.131 In addition, a diagram of model PM2.5 response at the 

 

128 WOEA, p. A-37 to A-38, Figs 23 and 24. PM2.5 increases when VOC decreases, for any given level of NOx. 

129 WOEA, p. A-3, and section 5.d, pp. A-30 to A-39. 

130 WOEA, p. A-38. See also, Kleeman, M.K., Ying, Q., and Kaduwela, A., 2005, Control strategies for the reduction of 

airborne particulate nitrate in California's San Joaquin Valley, Atmospheric Environment, 39: 5325-5341 September 2005. 

doi:10.1016/j.atmosenv.2005.05.044; cited in Plan Modeling Protocol.p.F-36). A similar statement is made in the 2014 Chen 

et al. paper, citing Qi Ying, Jin Lu, Michael Kleeman, Modeling air quality during the California Regional PM10/PM2.5 Air 

Quality Study (CPRAQS) using the UCD/CIT source-oriented air quality model - Part III. Regional source apportionment of 

secondary and total airborne particulate matter, Atmospheric Environment, Volume 43, Issue 2, January 2009, Pages 419-

430, ISSN 1352-2310, DOI: 10.1016/j.atmosenv.2008.08.033. The Chen paper actually cites “Part I” of the Ying paper, not 

this Part III. However, none of these papers gives the basis for the statement that background ozone is the dominant nitrate 

oxidant. 

131 WOEA, Table 2, p. A-27 (see VOC columns for Bakersfield, Visalia, and Corcoran). 
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Bakersfield-California site to various combinations of NOx and VOC reductions show graphically that 

VOC reductions increase PM2.5, for any given level of NOx.

132 For other monitoring sites, such as 

Fresno and Angiola, these NOx vs. VOC diagrams show mixed effects on PM2.5, albeit generally of 

small magnitude, depending on the level of ambient PM2.5 as VOC emissions are reduced. 

The 2015 PM2.5 Plan includes additional VOC vs. NOx isopleth diagrams from a 2005 Kleeman 

et al. paper.133 The key ones show that the effect of reducing VOC for all sources increases total PM2.5

nitrate for any given level of NOx emissions. 134 The Plan states that the VOC disbenefit occurs because 

reducing VOCs can reduce the organic nitrate “sink” that makes nitrate unavailable, thus freeing it for 

ammonium nitrate formation.135

In sum, the information provided by the State and District in the Plan indicates that: a) 

wintertime levels of secondary organic aerosol measured in the SJV are low and therefore the direct

products of VOC emissions do not contribute significantly to PM2.5 levels above the standard in the SJV; 

and b) wintertime reductions in VOC emissions in the SJV, when PM2.5 concentrations are high, would 

not reduce ambient PM2.5 levels, and therefore the indirect products of VOC emissions also do not 

contribute significantly to PM2.5 levels above the standard in the SJV. Based on this information, we 

 

132 WOEA, Figure 18, p. A-28. This diagram shows the model PM2.5 response at the Bakersfield-California site to reductions 

in various combinations of precursors. Subfigure “b)” shows NOx reductions plotted against VOC reductions. For a given 

level of NOx, in decreasing VOC by moving leftward along a horizontal line (representing constant NOx), one crosses the 

lines of constant PM2.5 (isopleths) into regions of increased PM2.5. The 2012 PM2.5 Plan presents similar diagrams for the 

various monitoring sites. 2012 PM2.5 Plan, Chapter 4, Figures 4-15 through 4-2334, pp. 4-31 to 4-40. 

133 Kleeman, M.K., Ying, Q., and Kaduwela, A., 2005, “Control strategies for the reduction of airborne particulate nitrate in 

California's San Joaquin Valley”, Atmospheric Environment, 39: 5325-5341 September 2005. 

doi:10.1016/j.atmosenv.2005.05.044. This paper was discussed in our TSD for the 2008 PM2.5 Plan, though the 2008 PM2.5

Plan did not include the diagrams. 

134 WOEA, upper left quadrant of Figures 19 to 21, pp. A-32 to A-34. 

135 WOEA, pp. A-31, citing. Z. Meng, D. Dabdub, and J. H. Seinfeld, "Chemical Coupling Between Atmospheric Ozone and 

Particulate Matter", Science 277, 116 (1997); DOI: 10.1126/science.277.5322.116. The Meng paper cites the organic nitrate 

sink as a possibility in PM chemistry. The Plan provides no direct evidence that this reaction is important in the SJV, though 

it is plausible. 
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propose to determine that, at this time, VOC emissions do not contribute significantly to ambient PM2.5

levels that exceed the 1997 PM2.5 NAAQS in the SJV nonattainment area. 

e. Recommendations for Further Analyses 

The EPA believes that several precursor issues warrant further explanation and exploration in 

future PM2.5 plans. For ammonia, an explanation should be provided for the apparent conflict between 

NOx as a “limiting” precursor for ammonium nitrate formation and modeling that nevertheless shows 

some benefits from ammonia emission reductions. In the 2012 PM2.5 Plan, ammonia reductions for Kern 

County alone were simulated along with reductions for the area as a whole. Further exploration of the 

effect of more specific localized controls would inform decisions on whether ammonia controls should 

be part of the control strategy in the next PM2.5 plan. 

For VOC, the apparent conflict between different past modeling studies on whether VOC 

emission reductions are beneficial or not also should be more fully explained. As mentioned above, and

discussed further in the EPA’s TSD for the 2012 PM2.5 Plan,136 those studies showing a VOC benefit can 

be discounted on various grounds, but there does not appear to be a full explanation of the chemistry 

differences seen. Differences between the models used, their chemical mechanisms, their emissions and 

meteorological inputs, and the episodes they are applied to all cause differences in study results. Without 

a fuller reconciliation of those results, it is difficult to know whether or not chemistry sensitive to VOC 

reductions could still be operating today in the SJV. Also mentioned above, the Plan’s WOEA asserts 

that background ozone levels are sufficient to provide the oxidants needed for nitrate formation, even

without the VOC-mediated generation of ozone within the SJV.137 But little support has been provided 

 

136 EPA Region 9, “Technical Support Document, Proposed Action on the San Joaquin Valley 2012 PM2.5 State 

Implementation Plan and 2014 Supplemental Document and Proposed Reclassification of the San Joaquin Valley as Serious 

Nonattainment for the 2006 PM2.5 Standard,” December 2014. 

137 WOEA, p. A-38. 
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for this assertion, other than similar assertions in a few journal papers. More concrete evidence on this 

issue should be provided in future plans. 

A related issue is why a VOC disbenefit occurs. One explanation is that VOC can remove nitrate 

via a “sink” reaction to organic nitrates, so reducing VOC frees nitrate to form PM2.5. This explanation 

is provided in a journal paper posing the nitrate sink as a possibility in PM chemistry. While this is

plausible, no evidence has been provided from any studies during the ten years since the paper was 

published that this particular phenomenon is actually occurring in the SJV modeling or atmosphere. 

Some of these issues may be resolved through better documentation and explanation in the SIP 

submission of what is already known; others may require quantitative examination of particular 

chemical pathways in the modeling or ambient measurements. 

Evaluation of the available research and its implications for the effectiveness of various 

precursor emissions controls would also be useful as part of the next plan. This research includes 

projects funded by the San Joaquin Valley-wide Air Pollution Study Agency, including “Improve 

emission estimates for urban ammonia sources,” “Update of CRPAQS conceptual model and synthesis 

of results,” and “Develop Improvements to the PM2.5 Inventory to Better Reconcile with Ambient 

Measurements.” The CARB Staff Report refers to several recent field studies relevant for the SJV, 

including ARCTAS-CARB, CalNex2010, and DISCOVER-AQ, all of which should be examined for 

their implications for the SJV’s atmospheric chemistry and the effectiveness of various precursor 

emissions controls. 
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Some results from the CalNex study are already available in a Synthesis document.138 While 

CalNex was conducted during the summer of 2010, some of its findings may be relevant for PM2.5

formation in the SJV, even though such formation is greatest in winter. Finding I2b (pp. 63-64) suggests 

that the SJV ammonia inventory is underestimated by a factor of three; if confirmed, this may have 

implications for modeling, the effectiveness of ammonia controls, and the amount of NOx used in the 

Plan to offset the ammonia inventory increases. Finding I3 (p. 65) highlights ammonia reactions with 

carboxylic acids and the resulting enhancement of secondary organic aerosol (SOA); the importance of 

this pathway in modeling winter PM2.5 may need to be explored. Several other findings relate to SOA. 

Finding L2 (p. 75) stated significant SOA formation at night at Bakersfield. Finding N2 (p. 86) stated

SOA as 72% of Bakersfield ultra-fine particulate matter (i.e., PM less than 1 micrometer in diameter) 

(this contrasts with the 5% of PM2.5 used in the Plan), and also stated that SOA dominated daytime 

particle growth. Findings W3a and W3b (p. 129) stated the importance of anthropogenic VOC as the 

main SOA precursor, and nitrate as a VOC oxidant. While many of these findings may be relevant 

mostly for summer conditions, their implications for chemical pathways and controls in winter should be 

examined. 

3. Proposed Action 

Based on a review of the information provided in the 2015 PM2.5 Plan and other information 

available to the EPA, we propose to determine that at this time VOC emissions do not contribute 

significantly to ambient PM2.5 levels which exceed the 1997 annual and 24-hour PM2.5 NAAQS in the 

SJV and, therefore, that VOCs may be excluded from the State’s evaluation of potential control 

 

138 Synthesis of Policy Relevant Findings from the CalNex 2010 Field Study (California Research at the Nexus of Air Quality 

and Climate Change): Final Report to the Research Division of the California Air Resources Board, David D. Parrish, NOAA 

Earth System Research Laboratory, March 27, 2014. Available at http://www.esrl.noaa.gov/csd/projects/calnex/. 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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measures for purposes of these standards in this area. Consistent with the statutory requirements under 

subpart 4, all other PM2.5 precursors (i.e., NOx, SO2, and ammonia) must be included in the State’s 

evaluation of potential control measures for the 1997 PM2.5 NAAQS in the SJV area, including 

nonattainment NSR provisions to implement the requirements of subpart 4.139 We discuss the State’s 

evaluation of potential control measures for NOx, SO2, and ammonia, as well as direct PM2.5, in section 

V.D. of this proposed rule. 

D. Best Available Control Measures and Most Stringent Measures 

As discussed in section IV.B of this proposed rule, section 189(b)(1)(B) of the Act requires for 

any serious PM2.5 nonattainment area that the State submit provisions to assure that the best available 

control measures (BACM) for reducing emissions of PM2.5 and PM2.5 precursors will be implemented no 

later than four years after the date the area is reclassified as a serious area. Because the EPA reclassified 

the SJV area as Serious nonattainment for the 1997 PM2.5 NAAQS effective May 7, 2015, the date four 

years after reclassification is May 7, 2019. In this case, however, the Serious area attainment date for the 

SJV area under section 188(c) is no later than December 31, 2015, and to qualify for an extension of this 

date under section 188(e) the State must, among other things, demonstrate attainment by the most 

expeditious alternative date practicable. Given these circumstances, we are evaluating the Plan’s control 

strategy for implementation of BACM as expeditiously as practicable.140

 

139 Absent a demonstration to EPA’s satisfaction that major stationary sources of ammonia emissions do not contribute 

significantly to ambient PM2.5 levels that exceed the NAAQS in the SJV area, under CAA section 189(e) major stationary 

sources of ammonia are subject to the control requirements that apply to major stationary sources of direct PM2.5, including 

nonattainment NSR requirements. We intend to evaluate the adequacy of the District’s nonattainment NSR program for PM2.5

upon submission of the NSR SIP revision due May 7, 2016, which is the date 12 months after EPA’s reclassification of the 

SJV as Serious nonattainment for the 1997 PM2.5 NAAQS became effective. 80 FR 18528 (April 7, 2015). 

140 CAA section 189(b)(1)(B) establishes an outermost deadline (“no later than four years after the date the area is 

reclassified”) and does not preclude an earlier implementation deadline for BACM where necessary to satisfy the attainment 

requirements of the Act. 
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In addition, before the EPA may extend the attainment date for a Serious nonattainment area 

under CAA section 188(e), the State must, among other things, demonstrate to the satisfaction of the 

Administrator that the plan for the area includes the most stringent measures that are included in the

implementation plan of any State or are achieved in practice in any State, and can feasibly be 

implemented in the area (MSM). As discussed above, we have established a process for evaluating 

BACM in serious area plans and a similar process for evaluating MSM. Because of the substantial 

overlap in the source categories and controls evaluated for BACM and those evaluated for MSM, we 

present our evaluation of the 2015 PM2.5 Plan’s provisions for including MSM alongside our evaluation 

of the Plan’s provisions for implementing BACM for each identified source category. We provide a 

more detailed evaluation of many of the District’s control measures for stationary and area sources in

our “Technical Support Document for the EPA’s Evaluation of Fine Particulate Matter Best Available 

Control Measures and Most Stringent Measures for the San Joaquin Valley Air Pollution Control 

District,” January 2016 (“SJV Rules TSD”). 

1. Identifying the Sources of PM2.5 and PM2.5 Precursors 

 The first step in determining BACM and MSM is to develop a detailed emissions inventory of 

the sources of direct PM2.5 and PM2.5 precursors that can be used with modeling to determine the effects 

of these sources on ambient PM2.5 levels. The EPA’s past guidance on Serious area plans in the 

Addendum suggested that the second step is to use modeling to identify those source categories that 

have a greater than de minimis impact on ambient PM2.5 concentrations.141

 As discussed in section V.A of this proposed rule, Appendix B of the 2015 PM2.5 Plan contains 

the planning inventories for direct PM2.5 and all PM2.5 precursors (NOx, SO2, VOC, and ammonia) for 

 

141 Addendum at 42012. 
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the SJV PM2.5 nonattainment area together with documentation to support these inventories. The District 

used available speciation data to identify de minimis thresholds, also referred to in the Plan as 

“significant emission levels,” for direct PM2.5, NOx, and SOx.

142 Based on these thresholds, which are 

described in Chapter 5 of the Plan, the District identified the following six source categories as emission 

sources in the SJV that emit pollutants at levels exceeding its selected de minimis thresholds (i.e., 

“significant” source categories): 

1. Open Burning; 

2. Glass Melting Furnaces; 

3. Agricultural Conservation Management Practices; 

4. Commercial Charbroiling; 

5. Wood Burning Fireplaces and Wood Burning Heaters; and 

6. Paved and Unpaved Roads.143

CARB identified most mobile source categories as “significant” and identified only several (e.g., 

cargo handling equipment, motorcycles, recreational boats, off-road recreational vehicles and 

commercial harbor craft) as de minimis source categories.144 

Separately in Appendix C and Appendix D of the Plan, however, both CARB and the District 

identified all of the sources of direct PM2.5, NOx, SOx and ammonia in the SJV that are subject to State 

or District emission control measures and provided their evaluations of these regulations for compliance 

with BACM and MSM requirements. Table 3 identifies the source categories in SJV that are under State 

and District jurisdiction, each source category’s 2012 emissions of direct PM2.5, NOx, and SOx in tons 

per day (tpd), and, for each source category, the regulations that the State and District have relied on in 

the Plan to satisfy BACM and MSM requirements. 

Table 3. 2015 PM2.5 Plan – Source Categories Evaluated for BACM and MSM 

 

142 2015 PM2.5 Plan, Chapter 5, section 5.4 (“De Minimis Thresholds for Determining Significant Source Categories”).

143 Id. at Table 5-2 (“Valley Source Category De Minimis Determinations (using 2012 data)”). 

144 2015 PM2.5 Plan at Appendix D. 
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Source Category Rule Number

(if any) * 

2012 PM2.5

(tpd) 

2012 NOx

(tpd) 

2012 SOx

(tpd) 

Stationary and Area Source Categories under District Jurisdiction 

Open Burning 4103 2.27 1.61 0.05 

Reduction of Animal Matter 4104 0.03 0.00 0.00 

Prescribed Burning and Hazard Reduction 

Burning 

4106 0.76 0.07 0.03 

Particulate Matter Emissions from the 

Incineration of Combustible Refuse 

4203 0.00 0.00 0.00 

Cotton Gins 4204 0.22 0.00 0.00 

Fuel Burning Equipment 4301 N/A N/A N/A 

Boilers, Steam Generators, and Process 

Heaters Greater than 5.0 MMBtu/hr 

4306/4320 1.27 1.93 0.60 

Boilers, Steam Generators, and Process 

Heaters—2.0 to 5.0 MMBtu 

4307 0.32 0.49 0.15 

Boilers, Steam Generators, and Process 

Heaters—0.075 to less than 2.0 MMBtu 

4308 0.61 0.92 0.28 

Dryers, Dehydrators, and Ovens 4309 0.85 0.20 0.47 

Flares 4311 0.16 0.56 0.33 

Lime Kilns 4313 0.00 0.00 0.00 

Solid Fuel Fired Boilers, Steam Generators, 

and Process Heaters 

4352 0.62 2.69 0.56 

Glass Melting Furnaces 4354 0.33 6.04 1.96 

Conservation Management Practices 

• Tilling Dust 

• Harvest Operations Dust 

• Dust from Ag Lands (non-pasture) 

• Dust from Pasture Lands 

4550 

5.17 

7.28 

6.15 

1.09 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

0.00 

Commercial Charbroiling 4692 2.84 0.00 0.00 

Internal Combustion Engines 4702 0.49 13.06 0.12 

Stationary Gas Turbines 4703 1.22 3.09 0.22 

Sulfuric Acid Mist 4802 0.00 0.00 0.75 
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Source Category Rule Number

(if any) * 

2012 PM2.5

(tpd) 

2012 NOx

(tpd) 

2012 SOx

(tpd) 

Wood Burning Fireplaces and Wood Burning 

Heaters 

4901 4.48 0.50 0.08 

Residential Water Heaters 4902 0.21 2.21 0.06 

Natural Gas-Fired, Fan-Type Central Furnaces 4905 0.20 2.46 0.06 

General Requirements 8011 N/A N/A N/A 

Construction, Demolition, Excavation, 

Extraction, and Other Earthmoving Activities 

8021 1.46 0.00 0.00 

Bulk Materials 8031 0.04 0.00 0.00 

Carryout and Trackout (emission included in 

Paved and Unpaved Roads, Rule 8061, below) 

8041 N/A N/A N/A 

Open Areas 8051 0.34 0.00 0.00 

Paved and Unpaved Roads 8061 7.59 0.00 0.00 

Unpaved Vehicle/Equipment Traffic Areas 8071 0.59 0.00 0.00 

Agricultural Sources 8081 1.21 0.00 0.00 

Lawn and Garden Equipment SC 001 0.04 0.58 0.00 

Energy Efficiency SC 002 N/A N/A N/A 

Fireworks SC 003 N/A N/A N/A 

Sand and Gravel Operations SC 004 0.09 0.00 0.00 

Asphalt/Concrete Operations (Mineral 

Processes) 

SC 005 0.82 0.20 0.36 

Almond Hulling/Shelling Operations SC 006 0.38 0.00 0.00 

Pistachio Hulling/Shelling Operations 

(emissions included in Almond 

Hulling/Shelling above) 

SC 007 N/A N/A N/A 

Agricultural Material Screening/Shaking 

Operations (emissions included in other 

control categories) 

SC 008 N/A N/A N/A 

Tub Grinding (emissions included in IC 

engines, Rule 4702, fugitive emissions 

accounted for in stationary and area inventory) 

SC 009 N/A N/A N/A 

Abrasive Blasting SC 010 0.33 0.00 0.00 

Mobile Source Categories under State Jurisdiction 

Light- and Medium-Duty Vehicles ** 1.9 32.2 *** 
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Source Category Rule Number

(if any) * 

2012 PM2.5

(tpd) 

2012 NOx

(tpd) 

2012 SOx

(tpd) 

Heavy-Duty Vehicles ** 4.8 138.6 *** 

Off-Road Vehicles and Engines (excludes 

Cargo Handling Equipment) 

** 1.1 19.2 *** 

Farm Equipment ** 2.9 50.4 *** 

Cargo Handling Equipment ** 0.0 0.1 *** 

Other Mobile Sources 

• Motorcycles 

• Recreational Boats 

• Off-Road Recreational Vehicles 

• Commercial Harbor Craft 

** 

0.0 

0.4 

0.0 

0.0 

1.0 

1.6 

0.1 

0.7 

*** 

Source: 2015 PM2.5 Plan, Chapter 5, Table 5-2; Appendix C (“BACM and MSM for Stationary 

Sources”); and Appendix D (“BACM and MSM for Mobile Sources”), except as otherwise noted. 

* “SC” refers to a source category that is subject to either several District rules or none. 

** See 2015 PM2.5 Plan, Appendix D for a discussion of the State measures that cover these mobile 

source categories. 

*** See 2015 PM2.5 Plan, Appendix B (Emissions Inventory) for SOx emission levels. 

With respect to ammonia, the District states in Appendix C of the 2015 PM2.5 Plan that ammonia 

is an “insignificant” PM2.5 precursor in the SJV but also provides an analysis of several SIP-approved 

District regulations that control ammonia emissions.

145 We provide our evaluation of these regulations 

below and further in the EPA’s SJV Rules TSD. 

Because the State and District have evaluated a much larger set of emission sources than those 

identified as “significant” sources in the Plan, and because the District’s evaluation of de minimis 

thresholds entirely excludes consideration of ammonia emission sources, the EPA is not proposing any 

action with respect to the District’s selected de minimis thresholds for BACM and MSM purposes. 

Instead, based on the Plan’s more comprehensive evaluation of State and District regulations that apply 

to stationary, area, and mobile sources of direct PM2.5, NOx, SOx and ammonia in the SJV, we propose 

 

145 2015 PM2.5 Plan, Appendix C, at pp. C-239 to C-280. 
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to find that the 2015 PM2.5 Plan appropriately identifies all emission sources and source categories that 

must be subject to evaluation for potential control measures consistent with the requirements of subpart 

4. 

2. Identification and Implementation of BACM and MSM 

As part of its process for identifying candidate BACM and MSM and considering the technical 

and economic feasibility of additional control measures, CARB and the District reviewed the EPA’s 

guidance documents on BACM, guidance documents on control measures for direct PM2.5, NOx, and 

SOx emission sources, and control measures implemented in other ozone and PM2.5 nonattainment areas 

in California and other states. The State’s and District’s evaluations of potential BACM and MSM for 

each source category identified in Table 3 above is found in Appendix C and Appendix D of the 2015 

PM2.5 Plan. In the following sections, we review key components of the State’s and District’s 

demonstrations concerning BACM and MSM for sources of direct PM2.5, NOx, SOx and ammonia 

emissions in the SJV. We provide a more detailed evaluation of the District’s regulations in the EPA’s

SJV Rules TSD, together with recommendations for improvements to these rules. 

Based on our evaluation of these State and District demonstrations, we propose to determine that 

the 2015 PM2.5 Plan provides for the implementation of BACM and MSM for sources of direct PM2.5

and PM2.5 precursors as expeditiously as practicable, in accordance with the requirements of CAA 

sections 189(b)(1)(B) and 188(e). 

a. District Measures for Stationary and Area Sources 

The District’s BACM and MSM process is described in the 2015 PM2.5 Plan, Chapter 5, section 

5.3 (“BACM/MSM Evaluation Process”) and in Appendix C. The District followed a process similar to 

that used by Arizona in the Maricopa County PM10 Serious Area Plan, the only other air quality plan in 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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the nation that includes a BACM and MSM demonstration for purposes of requesting an attainment date 

extension under CAA section 188(e).146

For each identified source category, the District first identified potential control measures 

included in SIPs for other areas, addressed in federal regulations or guidance (e.g., control technique 

guidelines (CTGs), alternative control techniques (ACTs), or new source performance standards 

(NSPSs)), or addressed in state or local regulations or guidance (e.g., Air Toxic Control Measures 

(ATCMs).147 The District evaluated these identified potential control measures to determine whether 

implementation of the measures would be technologically and economically feasible in the SJV.148 In 

addition, the District considered other available control options (beyond those included in other SIPs or 

identified in federal/state regulations or guidance), such as measures that the State or District have

previously considered “beyond RACT” and measures that have been implemented in practice in other 

areas. The District also evaluated these potential control measures to determine whether their 

implementation would be technologically and economically feasible in the SJV. The EPA’s SJV Rules 

TSD provides a more detailed evaluation of many of these District regulations and our recommendations 

for rule improvements. 

Open Burning 

SJVUAPCD Rule 4103 (“Open Burning”), as amended April 15, 2010, is designed to minimize 

impacts of smoke and other air pollutants from open burning of agricultural waste and other materials.149

The rule restricts the type of materials that may be burned and establishes other conditions and 

 

146 65 FR 19964 (April 13, 2000) (proposed action on Maricopa County Serious Area Plan); 66 FR 50252 (October 2, 2001) 

(proposed action on Maricopa County Serious Area Plan); and 67 FR 48718 (July 25, 2002) (final action on Maricopa 

County Serious Area Plan). 

147 2015 PM2.5 Plan, Chapter 5; and Appendix C, pp. C-4 to C-6. 

148 Id. 

149 See generally SJVUAPCD Rule 4103, as amended April 15, 2010; see also 2015 PM2.5 Plan, Appendix C at pp. C-14 to 

C-15. 
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procedures for open burning in conjunction with the District’s Smoke Management Program.150 The 

EPA approved this rule into the California SIP on January 4, 2012.151

The District compared Rule 4103 to several other open burning rules implemented in other parts 

of California and found no other rules more stringent as a whole than those in Rule 4103. According to

the District, although the South Coast Air Quality Management District (SCAQMD) implements a rule 

that restricts burning on residential wood combustion (RWC) curtailment days (Rule 444) and District 

Rule 4103 does not contain the same restriction, in practice the District currently bans all burning on 

RWC curtailment days through implementation of its Smoke Management Program, which specifically 

allocates allowable burn acreage for 103 geographic zones based on local meteorology.152 We note that a 

restriction on burning on RWC curtailment days by itself may not consistently reduce wintertime PM2.5

emission levels as it could shift more waste burning activity to days with more favorable meteorology. 

Sections 41855.5 and 41855.6 of the California Health and Safety Code require the District to 

prohibit open burning of specific crop categories unless the District determines either that there is no 

economically feasible alternative means of eliminating the waste or that there is no long-term federal or 

state funding commitment for the continued operation of biomass facilities in the SJV or for the 

development of alternatives to burning.153 The District has considered the technical and economic 

feasibility of alternatives to burning several times in the last several years and concluded that such

alternatives are not feasible for selected crop categories at this time.154

Boilers, Steam Generators, and Process Heaters Greater than 5.0 MMBtu/hr 

 

150 Id. 

151 77 FR 214 (January 4, 2012). 

152 2015 PM2.5 Plan, Appendix C at pp. C-8 to C-10.

153 California Health & Safety Code, sections 41855.5 and 41855.6. 

154 2015 PM2.5 Plan, Appendix C, pp. C-8 to C-15. 
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SJVUAPCD Rule 4306 (“Boilers, Steam Generators, and Process Heaters – Phase 3”), as 

amended October 16, 2008, establishes NOx emission limits ranging from 5 to 30 ppm and related 

operational requirements for gaseous fuel- or liquid fuel-fired boilers, steam generators, and process

heaters with total rated heat input greater than 5 million Btu per hour (MMBtu/hr).155 The EPA approved 

Rule 4306 into the California SIP on January 13, 2010.156 SJVUAPCD Rule 4320 (“Advanced Emission 

Reduction Options for Boilers, Steam Generators, and Process Heaters Greater Than 5.0 MMBtu/hr”), 

as adopted October 16, 2008, establishes more stringent NOx emission limits (5 to 12 ppm) and related 

operational requirements for these units but allows sources to pay an emission fee in lieu of compliance 

with the NOx emission limits.157 The EPA approved Rule 4320 into the California SIP on March 25, 

2011 but determined that this rule, as approved, may not be credited for attainment planning purposes 

because the fee provision renders the NOx emission limits unenforceable.158

The District compared both Rule 4306 and Rule 4320 to several other analogous rules 

implemented in other parts of California, including the Sacramento metropolitan area, the South Coast,

and the Bay Area.159 According to the District, the NOx emission limits in Rule 4306 are generally 

within the same range as, and in some cases are more stringent than, those contained in analogous rules 

implemented by these other California agencies, except that the SCAQMD implements a rule containing 

NOx emission limits that are potentially more stringent for units of certain sizes (SCAQMD Rule 1146, 

as amended November 1, 2013).160

 

155 See generally SJVUAPCD Rule 4306, as amended October 16, 2008; see also 2015 PM2.5 Plan, Appendix C, p. C-35.

156 75 FR 1715 (January 13, 2010). 

157 See generally SJVUAPCD Rule 4320, as adopted October 16, 2008; see also 2015 PM2.5 Plan, Appendix C, p. C-35. 

158 76 FR 16696 (March 25, 2011). 

159 2015 PM2.5 Plan, Appendix C, p. C-38. 

160 Id. 
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SCAQMD Rule 1146 establishes a 5 ppm NOx emission limit for larger units (i.e., those with 

heated rate inputs above 75 MMBtu/hr), whereas Rule 4320 establishes a 7 ppm limit and Rule 4306 

establishes a 9 ppm limit for such units.161 SCAQMD Regulation XX (“Regional Clean Air Incentives 

Market” or “RECLAIM”) also applies to units within the same range of sizes as Rule 4320 but allows 

sources to comply with emission caps by purchasing RECLAIM Trading Credits.162 We do not have 

information about the rated heat input of the units subject to RECLAIM in the South Coast area and 

therefore cannot conclude that the lower NOx emission limits for larger boilers in SCAQMD Rule 1146 

are technically and economically feasible for implementation in the SJV at this time. 

The District also considered the technical and economic feasibility of alternative NOx and PM2.5

control techniques for this source category, such as low temperature oxidation and EMx system for NOx

control, and alternative fuels, electrostatic precipitators (ESP) and wet scrubbers for direct PM2.5

control.163 Based on its consideration of the technical constraints and costs associated with each of these 

control options, the District concluded that these additional controls are not feasible for implementation 

in the SJV at this time.164

 

Although the NOx emission limits in Rule 4320 do not satisfy the Act’s enforceability 

requirements because of the option to pay an emission fee, we note that the requirement to pay the 

emission fee itself is an enforceable requirement and that the fee provision appears to function 

effectively as a pollution deterrent.165

 

161 Compare SCAQMD Rule 1146 (as amended November 1, 2013) at section (c)(1)(F) to SJVUAPCD Rule 4320 at Table 1, 

category B.a and SJVUAPCD Rule 4306 at Table 1, category B; see also 2015 PM2.5 Plan, Appendix C, p. C-38.

162 RECLAIM is a market incentive program designed to allow facilities flexibility in achieving emission reduction 

requirements for NOx and SOx through, among other things, add-on controls, equipment modifications, reformulated 

products, operational changes, shutdowns, and the purchase of excess emission reductions. See SCAQMD Rule 2000, section 

(a). 

163 2015 PM2.5 Plan, Appendix C, p. C-39. 

164 2015 PM2.5 Plan, Appendix C, p. C-42. 

165 See section 3.b.5 of the EPA’s SJV Rules TSD. 
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Flares 

SJVUAPCD Rule 4311 (“Flares”), as amended June 18, 2009, establishes specific operational 

and administrative requirements to limit emissions of NOx, SOx, and VOCs from the operation of 

flares.166 Under Rule 4311, for each refinery flare and other flare with a capacity above 5 MMBtu/hr, the 

operator must submit a flare minimization plan (FMP) to the District describing relevant equipment and

preventative measures and demonstrating that the operator appropriately minimized flaring activity.167

The EPA approved Rule 4311 into the California SIP on November 3, 2011.168

The District compared Rule 4311 with several other analogous rules implemented in other parts 

of California, including the South Coast, Bay Area, Ventura County, and Santa Barbara, all of which 

require regulated sources to submit FMPs to the local districts.169 According to the District, most flares 

in the SJV occur in the oil and gas production industry and operate as emergency control devices, unlike 

many flares in the South Coast area and the Bay Area, which are significantly larger and operate as part 

of the refinery process.170 Because of wide variation in flaring operations in the SJV, the District 

concludes that requirements to submit details FMPs, as in Rule 4311, are the most effective means of 

reducing NOx and SOx emissions from flaring.171

The District also considered the technical and economic feasibility of alternative control 

techniques for flares, such as maximum monthly flared gas targets and requirements to capture gas 

before it is flared.172 Based on its consideration of the technical constraints and costs associated with 

 

166 See generally SJVUAPCD Rule 4311, as amended June 18, 2009; see also 2015 PM2.5 Plan, Appendix C, p. C-63. 

167 Id. 

168 76 FR 68106 (November 3, 2011). 

169 2015 PM2.5 Plan, Appendix C, p. C-73. 

170 Id. 

171 Id. 

172 2015 PM2.5 Plan, Appendix C, p. C-82. 
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these control options, the District concluded that these additional controls are not feasible for 

implementation in the SJV at this time.173 

Chapter 8 of the 2015 PM2.5 Plan includes a commitment by the District to conduct a 

comprehensive review of submitted FMPs to identify effective flare minimization practices; to evaluate

the technical and economic feasibility of implementing new and additional flare minimization practices

at affected facilities; to have a draft report available for public review and comment by December 1, 

2015; to develop a final report by March 31, 2016 after addressing public comments on these 

evaluations; and upon completion of these analyses, to work closely with affected operators to “evaluate 

and implement, when feasible, the most effective flare minimization practices through the FMP 

submittal and approval process under Rule 4311.”174 The District issued its draft report of FMPs on 

December 3, 2015, starting a 30-day public comment period.175

Solid Fuel-Fired Boilers 

SJVUAPCD Rule 4352 (“Solid Fuel-Fired Boilers, Steam Generators, and Process Heaters”), as 

amended December 15, 2011, establishes NOx emission limits and related operational requirements for 

boilers, steam generators, and process heaters that burn municipal solid waste (MSW), biomass, and 

other solid fuels.176 Specifically, the rule establishes NOx emission limits of 165 ppmv for units burning 

MSW, 90 ppmv for units burning biomass, and 65 ppmv for units burning other solid fuels.177 The EPA 

approved this rule into the California SIP on November 6, 2012.178

 

173 2015 PM2.5 Plan, Appendix C, p. C-84. 

174 Id. at Chapter 8, Section 8.1 (pg. 8-2). 

175 SJVUAPCD, “Draft Further Study, Rule 4311 Flare Minimization Plans, 2015,” December 3, 2015. 

176 See generally SJVUAPCD Rule 4352, as amended December 15, 2011; see also 2015 PM2.5 Plan, Appendix C, p. C-87. 

177 Id. 

178 77 FR 66548 (November 6, 2012). 
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According to the District, the NOx emission limits in Rule 4352 have been lowered significantly 

over time and are at least as stringent as analogous requirements implemented in other parts of 

California. The District compared the provisions of Rule 4352 to potentially more stringent requirements 

implemented in Sacramento County, the South Coast area, and the Bay Area, but these comparisons are 

of limited value because no affected facilities are subject to the Sacramento Metropolitan Air Quality

Management District’s (SMAQMD) rule, and no sources are currently complying with the 40 ppmv 

limit in the SCAQMD’s or Bay Area Air Quality Management District’s (BAAQMD’s) rules. 179 

Nonetheless, we note that three other air districts in California implement regulations that apply to active 

biomass-fueled units: Yolo-Solano Air Quality Management District (YSAQMD), El Dorado County 

Air Quality Management District (EDAQMD) and Placer County Air Pollution Control District 

(PCAPCD). The NOx emission limits in these regulations are all within the same range as SJVAPCD’s 

limit of 90 ppm corrected to 3% O2 on a 24-hour block average.180

The District also considered the technical and economic feasibility of alternative control 

techniques for this source category, such as selective catalytic reduction (SCR) for NOx control and 

ESPs or baghouses for direct PM2.5 control.181 Based on its consideration of the costs associated with 

SCR retrofits at units burning biomass, MSW, or other solid fuels, the District concluded that SCR for

these units is not economically feasible for sources in the SJV at this time.182 With respect to direct 

PM2.5 control, the District states that sources subject to Rule 4352 are subject to permit limits that 

require the best feasible controls.183

 

179 2015 PM2.5 Plan, Appendix C at p. C-89.

180 SJV Rules TSD at Section 3.d.2. See also 77 FR 66548 (November 6, 2012).

181 2015 PM2.5 Plan, Appendix C at pp. C-91 to C-101. 

182 2015 PM2.5 Plan, Appendix C at pp. C-95 – C-96 and C-98. 

183 Id. 
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We note that biomass- and MSW-fired units provide an environmental benefit by diverting these 

wastes from landfills and reducing open burning. 

Glass Melting Furnaces 

SJVUAPCD Rule 4354 (“Glass Melting Furnaces”), as amended May 19, 2011, establishes NOx, 

VOC, SOx, and PM10 emission limits and related operational requirements for glass melting furnaces.184

Specifically, the rule establishes NOx emission limits of 1.5 to 3.7 lb. NOx/ton glass, depending on glass 

product and averaging time, and SOx emission limits of 0.9 to 1.7 lb. SOx/ton glass.185 The EPA 

approved Rule 4354 into the California SIP on January 31, 2013.186

 According to the District, the NOx emission limits in Rule 4354 require implementation of oxyfuel firing or SCR systems, which are the best available NOx control techniques, and are at least as 

stringent as analogous requirements implemented in the South Coast and Bay Area.187

 

We are not aware of prohibitory rules for glass melting furnaces in other areas that are more 

stringent than Rule 4354. We note that the SCAQMD has found a 1.2 lb./ton NOx emission limit feasible 

through a Best Available Retrofit Control Technology (BARCT) determination under its RECLAIM 

program, but absent information about how affected sources in the South Coast area have complied with 

the available compliance options under RECLAIM, it is not clear that these lower NOx emission levels 

are technically and economically feasible for implementation in the SJV. 

Conservation Management Practices

SJVUAPCD Rule 4550 (“Conservation Management Practices”), as adopted August 19, 2004, 

establishes requirements for owners and operators of agricultural sites to implement conservation 

 

184 See generally SJVUAPCD Rule 4354, as amended May 19, 2011; see also 2015 PM2.5 Plan, Appendix C at pp. C-102. 

185 SJVUAPCD Rule 4354, as amended May 19, 2011, at pp. 5 and 7. 

186 78 FR 6740 (January 31, 2013). 

187 2015 PM2.5 Plan, Appendix C, p. C-102.
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management practices (CMPs) to control PM10 emissions from on-field crop and animal feeding 

operations.188 Under the rule, each owner/operator of an agricultural site must select and implement a 

CMP for each category of operations, including unpaved roads and unpaved vehicle/equipment traffic 

areas, and submit a CMP application to the District for its review and approval.189 The EPA approved 

this rule into the California SIP on February 14, 2006.190

According to the District, Rule 4550 is the most stringent rule of its kind.191 The District 

compared the provisions of Rule 4550 to analogous requirements implemented by air agencies in other 

parts of California (Imperial County, South Coast, and Sacramento County) and in Arizona, and found 

no requirements more stringent than those in Rule 4550.192 We note that it is difficult to directly 

compare the requirements among these rules because of the widely varying rule structures and 

operations of the affected agricultural sites. 

The District also considered the technical and economic feasibility of additional control options 

for this source category, such as misting to reduce PM10 emissions from disking activity and the use of 

new almond harvesting equipment.193 As to misting, the District found that the available information 

was not sufficient to demonstrate that this control technique would achieve its minimum standard of a 

10% reduction in PM10 emissions, so the District did not add this measure to the CMP list.194 As to the 

use of newer almond harvesting equipment, the District noted, based on a 2010-2011 study, that newer 

equipment would achieve significant PM10 emission reductions but found it was not necessary to revise 

the CMP list given use of newer almond harvesting equipment is already listed under an existing CMP 

 

188 See generally SJVUAPCD Rule 4550, as adopted August 19, 2004; see also 2015 PM2.5 Plan, Appendix C at pp. C-106. 

189 Id. 

190 71 FR 7683 (February 14, 2006). 

191 2015 PM2.5 Plan, Appendix C at pp. C-114.

192 Id. 

193 2015 PM2.5 Plan, Appendix C at pp. C-111. 

194 2015 PM2.5 Plan, Appendix C at pp. C-112. 
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category.195 Finally, the District considered adding windblown dust controls to Rule 4550 but 

determined that such controls would not substantially impact PM2.5 design values in the SJV because 

windblown dust events typically occur during the spring and fall seasons whereas the District asserts 

that PM2.5 values are driven by winter-time concentrations; PM2.5 values recorded during winter 

stagnation periods are usually much higher than those recorded during wind events; and the geologic 

component of peak PM2.5 concentration is a fraction of the mass formed by secondary processes and 

other sources.196

Chapter 8 of the 2015 PM2.5 Plan includes a commitment by the District to reevaluate Rule 4550, 

in close coordination with stakeholders (including agricultural industry representatives, CARB, and the 

EPA), for additional feasible control options; to have a draft report available for public review and 

comment by May 31, 2016; and to develop a final report by October 15, 2016 after addressing public 

comments on these evaluations.197

Commercial Charbroiling

SJVUAPCD Rule 4692 (“Commercial Charbroiling”), as amended September 17, 2009, 

establishes control requirements to reduce PM10 (of which PM2.5 is a component) and VOC emissions 

from chain-driven charbroilers.198 Specifically, the rule requires that chain-driven charbroilers be 

equipped and operated with a catalytic oxidizer with a control efficiency of at least 83% for PM10

emissions and 86% for VOC emissions.199 The EPA approved Rule 4692 into the California SIP on 

November 3, 2011.200

 

195 Id.

196 2015 PM2.5 Plan, Appendix C at pp. C-110.

197 Id. at Chapter 8, Section 8.3 (pg. 8-3). 

198 See generally SJVUAPCD Rule 4692, as amended September 17, 2009; see also 2015 PM2.5 Plan, Appendix C, p. C-115. 

199 Id.

200 76 FR 68103 (November 3, 2011). 
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The District compared the requirements in Rule 4692 to analogous requirements for chain-driven 

charbroilers implemented by the SCAQMD, Ventura County Air Pollution Control District (VCAPCD), 

and BAAQMD and found no requirements in these rules more stringent than those contained in Rule 

4692, with one exception in the BAAQMD rule.201 With respect to under-fired charbroilers (UFCs), the 

District found that no cost-effective control techniques have been demonstrated to date given technical 

challenges associated with controlling emissions from UFCs, which operate differently from chaindriven charbroilers.202 Although the BAAQMD has adopted a rule that establishes control requirements 

for both chain-driven and under-fired charbroilers, according to the District, a significant portion of the 

UFCs in the BAAQMD are not subject to the rule’s requirements for UFCs because they fall below the 

rule’s applicability thresholds.203 The District also stated that the BAAQMD has been unable to enforce 

its UFC requirements because no control technologies have been certified.204

 The District also considered the technical and economic feasibility of alternative control 

techniques for UFCs, such as catalytic oxidizers, high efficiency particulate-arresting filtration system, 

ESPs, and wet scrubbers.205 Based on its consideration of the technical difficulties and costs associated 

with installing these control devices at UFCs, the District concluded that these control techniques are not 

technically and economically feasible for sources in the SJV at this time.206 The District also stated, 

however, that it expects to begin testing some of these additional control options in mid-2015. The 

District’s Governing Board approved $750,000 for its Restaurant Charbroiler Technology Partnership 

 

201 2015 PM2.5 Plan, Appendix C, pp. C-116 to C-117.

202 Id. 

203 Id. 

204 Id. at p. C-116. 

205 Id. at pp. C-117, C-118. 

206 2015 PM2.5 Plan, Appendix C, pp. C-117 to C-119. 
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program, which would fund particulate emission control technology demonstration projects for under-fired 

charbroilers at restaurants in the SJV.207

 

 As part of the 2015 PM2.5 Plan, the SJVUAPCD submitted a commitment to amend Rule 4692 in 

2016 to add requirements for UFCs, with an anticipated compliance date of 2017.208 The Plan relies on 

this commitment for a portion of the direct PM2.5 emission reductions needed to attain the 1997 PM2.5

NAAQS.209

Internal Combustion Engines

SJVUAPCD Rule 4702 (“Internal Combustion Engines”), as amended November 14, 2013, 

establishes NOx, CO, VOC, and SOx emission limits and related operational requirements for internal 

combustion (IC) engines.210 The rule contains separate emission limits for spark-ignited IC engines used 

in agricultural operations (SI AO engines), spark-ignited IC engines used in non-agricultural operations 

(SI non-AO engines), and compression-ignited IC engines.211 The EPA proposed to approve this rule 

into the California SIP on December 2, 2015.212 The EPA approved a previous version of this rule into 

the California SIP on January 10, 2008.213

For SI non-AO engines, Rule 4702 establishes NOx emission limits ranging from 25 to 75 

ppmv.214 According to the District, these NOx emission limits are at least as stringent as many analogous 

 

207 SJVUAPCD Governing Board, Meeting Minutes of June 18, 2015 Governing Board Meeting, pp. 7-8. 

208 2015 PM2.5 Plan, Appendix C at p. C-119 and SJVUAPCD Governing Board Resolution 15-4-7A (April 16, 2015) at 

paragraph 7. 

209 2015 PM2.5 Plan, CARB Staff Report, p. 9. See also 2015 PM2.5 Plan, Chapter 7, section 7.1.2, p. 7-6, and Appendix C, 

section C.16, pp. C-115 to C-119, which describe the charbroiling rule revision commitment in the context of the 2015 PM2.5

Plan. 

210 See generally SJVUAPCD Rule 4702, as amended November 14, 2013; see also 2015 PM2.5 Plan, Appendix C at p. C120. 

211 Id. 

212 80 FR 75442 (December 2, 2015). 

213 73 FR 1819 (January 10, 2008). 

214 SJVUAPCD Rule 4702, as amended November 14, 2013, at Table 1. 
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control requirements implemented in the Bay Area, Sacramento Metro, and Ventura County areas.215

We also note that Rule 4702 limits are at least as stringent as analogous requirements in the Feather 

River, Placer County, Mojave Desert, and San Diego areas.216 

Some of the emission limits for SI non-AO engines in Rule 4702 are, however, less stringent 

than those implemented in the South Coast, El Dorado, and Antelope Valley areas for similar engines. 

Specifically, the SCAQMD has adopted an 11 ppmv limit for all IC engines217; El Dorado has adopted a 

25 ppmv limit for SI “rich-burn” engines and a 65 ppmv limit for SI “lean-burn” engines (except those 

used exclusively in agricultural operations);218 and Antelope Valley has adopted a 36 ppmv limit for IC 

engines (except those used exclusively in agricultural operations).219 The District considered the 

technical and economic feasibility of alternative control techniques for SI non-AO engines that would 

lower the emission levels for certain engines to 11, 25, and 65 ppmv, but found that for reasons of both 

technical and economic feasibility, NOx emission limits lower than those in Rule 4702 are generally not 

feasible for implementation in the SJV at this time.

220

For SI AO engines, Rule 4702 establishes NOx emission limits ranging from 90 to 150 ppmv.221

These NOx emission limits are more stringent than analogous control requirements implemented in the 

Sacramento Metro, Placer County, El Dorado, and Antelope Valley areas, which exempt AO engines 

from control requirements altogether, and are equivalent to analogous control requirements implemented

 

215 2015 PM2.5 Plan, Appendix C at pp. C-122 to C-123.

216 Feather River AQMD Rule 3.22; Placer County APCD Rule 242; Mojave Desert AQMD Rule 1160; and San Diego 

APCD Rule 69.4.1. 

217 SCAQMD Rule 1110.2, as amended February 1, 2008. 

218 El Dorado County AQMD Rule 233, as amended June 2, 2006. 

219 Antelope Valley AQMD Rule 1110.2, as amended January 21, 2003. 

220 See section 3.h (Internal Combustion Engines) of the EPA’s SJV Rules TSD, which provides a more detailed discussion of 

the District’s technical and economic feasibility analyses. 

221 SJVUAPCD Rule 4702, as amended November 14, 2013, at Table 3. 
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in the Mojave Desert area.222 The SCAQMD, however, has adopted an 11 ppmv limit for all IC 

engines,223 and the BAAQMD has adopted NOx emission limits ranging from 25-70 ppmv for all sparkignited IC engines.224 Thus, Rule 4702’s requirements for SI AO engines are at least as stringent as most 

but not all analogous requirements implemented in other parts of California. 

The District considered the technical and economic feasibility of alternative control techniques 

for SI AO engines that would lower their emission levels and found that for reasons of both technical 

and economic feasibility, NOx emission limits lower than those in Rule 4702 are generally not feasible 

for implementation within SJV’s agricultural industry at this time.225 We note that the SCAQMD, like 

SJVUAPCD, has provided economic incentive grants for agricultural engine retrofits and replacement in 

recognition of unique economic and technical circumstances in the agricultural industry.226

Finally, for compression-ignited IC engines (both those used in agricultural operations and those 

used in non-agricultural operations), Rule 4702 requires that all certified engines meet the EPA’s Tier 3 

and Tier 4 emission standards for nonroad diesel engines and that non-certified engines meet the same 

standards or a numerical NOx emission limit based on engine size.227

Stationary Gas Turbines

 SJVUAPCD Rule 4703 (“Stationary Gas Turbines”), as amended September 20, 2007, 

establishes NOx emission limits ranging from 5 to 25 ppm and related operational requirements for all 

stationary gas turbines with greater than 0.3 MW capacity.228 These units operate primarily in the oil and 

 

222 SMAQMD Rule 412, as amended June 1, 1995; Placer County APCD Rule 242, as adopted April 10, 2003; El Dorado 

County AQMD Rule 233, as amended June 2, 2006; Antelope Valley AQMD Rule 1110.2, as amended January 21, 2003; 

and Mojave Desert AQMD Rule 1160.1, as adopted January 23, 2012. 

223 SCAQMD Rule 1110.2, as amended February 1, 2008. 

224 Bay Area AQMD Regulation 9, Rule 8, as amended July 25, 2007. 

225 See section 3.h (Internal Combustion Engines) of the EPA’s SJV Rules TSD. 

226 SCAQMD Final Staff Report for Rule 1110.2, May 2005, Appendix B: Incentive Funding Available for Agricultural 

Engine Emission Reductions. 

227 SJVUAPCD Rule 4702, as amended November 14, 2013, at Table 4. 

228 SJVUAPCD Rule 4703, as amended September 20, 2007, at Table 5-3. 
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gas production and utility industries, with some also operating in manufacturing and government 

facilities.229 The EPA approved this rule into the California SIP on October 21, 2009.230

 According to the District, the NOx emission limits in Rule 4703 are more stringent than 

analogous control requirements implemented in many other parts of California, including the 

Sacramento Metro area, South Coast, and Ventura County.231 The District considered the technical and 

economic feasibility of alternative control techniques to reduce emissions further, such as the installation 

of SCR or installation of entirely new turbine systems, and concluded that these options are extremely

expensive and not economically feasible.232 The District also considered the potential for installation of 

EMx system for NOx control and concluded that this technology requires further testing before it will be 

generally available for implementation in the SJV.233

Wood Burning Fireplaces and Wood Burning Heaters

SJVUAPCD Rule 4901 (“Wood Burning Fireplaces and Wood Burning Heaters”), as amended 

September 18, 2014, is designed to limit emissions of PM, including PM2.5 and PM10, and other 

pollutants generated by the use of wood burning fireplaces, wood burning heaters, and outdoor wood 

burning devices. The rule establishes requirements for the sale/transfer, operation, and installation of 

wood burning devices and on the advertising of wood for sale within the SJV.234 The EPA proposed to 

approve this rule into the SIP on September 30, 2015.235

 

229 2015 PM2.5 Plan, Appendix C at p. C-142. 

230 74 FR 53888 (October 21, 2009). 

231 2015 PM2.5 Plan, Appendix C at p. C-144. 

232 Id. 

233 Id. 

234 See generally SJVUAPCD Rule 4901, as amended September 18, 2014. 

235 80 FR 58637 (September 30, 2015). Also, EPA approved a previous version of Rule 4901, as adopted October 16, 2008, 

into the SIP on November 10, 2009 (74 FR 57907). 
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Rule 4901 includes a mandatory two-tiered curtailment program. During a Level One Episodic 

Wood Burning Curtailment, which is declared when the PM2.5 concentration is forecasted to be between 

20-65 μg/m3

, operation of wood burning fireplaces and unregistered wood burning heaters is prohibited, 

but properly operated wood burning heaters that meet certification requirements and have a current 

registration with the District may be used. During a Level Two Episodic Wood Burning Curtailment, 

which is declared when the PM2.5 concentration is forecasted to be above 65 μg/m3 or the PM10

concentration is forecasted to be above 135 μg/m3, operation of any wood burning device is 

prohibited.236 

According to SJVAPCD, Rule 4901 is at least as stringent as analogous rules in other areas, 

including the South Coast, Bay Area, Sacramento Metro area, Washoe County, Nevada, and Washington 

State.237 We note that SCAQMD Rule 445 includes a mandatory curtailment of all devices when the 24-

hour average PM2.5 concentration is forecasted above 30 μg/m3, and SMAQMD Rule 421 bans operation 

of all wood burning devices when ambient PM2.5 concentrations are above 35 μg/m3

. According to the 

District, however, the small increase in emissions from registered clean burning devices when 

concentrations are between 20-65 μg/m3 in the SJV will be more than offset by the decrease in emissions 

from dirty devices when concentrations are between 20-30 μg/m3, which will reduce the build-up of 

emissions during long periods of stagnation experienced in the wintertime in the Valley.238

Rule 4901 incorporates all elements outlined in the EPA’s Strategies for Reducing Wood 

Smoke239 and includes comparable provisions available in other analogous rules. We are not aware of 

more stringent measures for reducing residential wood smoke that are technically and economically 

 

236 SJVUAPCD Rule 4901, as amended September 18, 2014, at paragraph 5.6. 

237 2015 PM2.5 Plan, Appendix C, pp. C-156. 

238 Rule 4901 Staff Report, p. 19. 

239 “Strategies for Reducing Residential Wood Smoke,” EPA-456/B-13-001, March 2013. 
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feasible for implementation in the SJV. Our Technical Support Document to support our separate 

proposal on Rule 4901 contains a more detailed discussion of this rule in comparison to analogous rules 

implemented elsewhere.240

Paved and Unpaved Roads 

SJVUAPCD Rule 8061 (“Paved and Unpaved Roads”), as amended August 19, 2004, is 

designed to limit fugitive dust emissions generated from paved and unpaved roads. The rule establishes

control measures and design criteria for existing public and private paved or unpaved roads, road 

construction projects, and road modification projects, such as requirements to stabilize unpaved roads by 

applying water, a uniform layer of washed gravel, chemical/organic dust stabilizers/suppressants, 

paving, or any other method demonstrated to effectively limit visible dust to 20% opacity.241 The EPA 

approved this rule into the SIP on February 17, 2006.242

The District compared Rule 8061 to SCAQMD Rule 1156 (“Further Reductions of 

Particulate Emissions from Cement Manufacturing Facilities”); SCAQMD Rule 1157 (“PM-10 

Emission Reductions from Aggregate and Related Operations”); SMAQMD Rule 403 (“Fugitive Dust”); 

VCAPCD Rule 55 (“Fugitive Dust”); Clark County Department of Air Quality Section 91 (“Fugitive 

Dust from Unpaved Roads, Unpaved Alleys, and Unpaved Easement Roads”), and Section 93 (“Fugitive 

Dust from Paved Roads and Street Sweeping Equipment”).243 Based on these evaluations, SJVUAPCD 

concluded that no other areas implemented requirements more stringent than those already in Rule 8061.

 

240 U.S. EPA Region 9, “Technical Support Document for EPA’s Proposed Rulemaking for the California State

Implementation Plan (SIP), San Joaquin Valley Unified Air Pollution Control District Rule 4901 Wood Burning Fireplaces 

and Wood Burning Heaters,” August 2015. See also section 3.f (Conservation Management Practices) of the EPA’s SJV 

Rules TSD. 

241 SJVUAPCD Rule 8061, as amended August 19, 2004, at section 5.2.1. 

242 71 FR 8461 (February 17, 2006). 

243 2015 PM2.5 Plan, Appendix C, pp. C-194 to C-197. 
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 The District also considered the feasibility of requiring control measures on paved and unpaved 

roads with less than 26 annual average daily trips (AADT). Such a measure would require more road 

owners/operators to implement control measures to reduce fugitive emissions from paved and unpaved 

roads. SJVUAPCD’s analysis of the emission inventory indicates that the majority of the particulate 

emissions attributable to unpaved roads are from roads with more than 26 AADT. Because these roads 

are already subject to the mitigation requirements of Rule 8061, the District concluded that the 

remaining emissions from unpaved roads with less than 26 AADT provide very little opportunity for 

additional emissions reductions. Additionally, the District noted that emissions from unpaved roads are 

lowest in the winter months, when exceedances of the 24-hour PM2.5 standard tend to occur. For these 

reasons, SJVUAPCD concluded that additional control measures for paved and unpaved road with less 

than 26 AADT would not achieve emission reductions.244

Asphalt/Concrete Operations

SJVUAPCD Rule 4101 (“Visible Emissions”), as amended February 17, 2005, establishes limits 

on opacity, which is often used as an indicator of PM emissions. SJVUAPCD Rule 4309 (“Dryers, 

Dehydrators, and Ovens”), as amended December 15, 2005, establishes NOx and CO emission limits for 

dryers, dehydrators and ovens firing gaseous or liquid fuel with a total rated heat input of at least 5.0 

MMBtu/hr. Under Rule 4309, asphalt/concrete manufacturing plants that operate equipment of this size 

are subject to NOx emission limits of 4.3 ppm (gaseous fuel) and 12.0 ppm (liquid fuel).245 The EPA 

approved Rule 4101 into the California SIP on August 11, 2005246 and approved Rule 4309 into the 

California SIP on May 30, 2007.247

 

244 Id. at p. C-196. 

245 SJVUAPCD Rule 4309, as adopted December 15, 2005, at p. 5. 

246 70 FR 46770 (August 11, 2005). 

247 72 FR 29886 (May 30, 2007). 
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According to the District, there are no state regulations that apply to this source category and no 

analogous rules in the Bay Area, Sacramento Metro, or Ventura County areas.248 The District evaluated 

analogous rules implemented in the South Coast and found no requirements more stringent than those in 

SJVUAPCD Rule 4101 and Rule 4309.249 We are not aware of more stringent control requirements for 

visible emissions or NOx emissions in other California districts for asphalt plants. 

The District also considered the technical and economic feasibility of using warm mix asphalt 

(WMA), a newer substance which is produced at temperatures 25 to 90 degrees (Fahrenheit) lower than 

hot mix asphalt (HMA) and which results in lower emissions because it requires less fuel to heat the 

asphalt. Although the use of WMA has grown steadily in the U.S., the District concluded that use of 

WMA at asphalt production facilities in the SJV is not technically and economically feasible at this time 

given the high costs of, and technical difficulties associated with, converting equipment.250

Chapter 8 of the 2015 PM2.5 Plan includes a commitment by the District to evaluate and promote 

the use of WMA in the SJV, in close coordination with stakeholders (including asphalt plant operators,

Caltrans, city and county planning agencies, CARB, and the EPA); to have a draft report available for 

public review and comment by December 1, 2015; and to develop a final report by March 31, 2016, 

after addressing public comments. As part of this evaluation, the District committed to (1) evaluate 

opportunities to further encourage transportation and county agencies to continue transitioning from 

HMA to WMA as feasible, (2) to explore the potential feasibility of additional control measures and the 

granting of mitigation credits for WMA usage through the District’s Indirect Source Review (ISR) 

program, and (3) to consider outreach and education opportunities for encouraging project developers 

 

248 2015 PM2.5 Plan at Appendix C, pp. C-219, C-220. 

249 Id. (citing SCAQMD Rule 1157 and Rule 403). 

250 Id. at pp. C-221, C-225. 
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and construction managers to increase the use of WMA.251 The District issued its draft report on WMA 

on December 1, 2015, starting a 30-day public comment period.252

Confined Animal Facilities (CAFs)

SJVUAPCD Rule 4570 (“Confined Animal Facilities”), as amended October 21, 2010, applies to 

large dairy, poultry, beef cattle feeding and swine CAFs and requires operators of such facilities to 

implement measures to control VOC emissions for each major stage of operation, e.g., feeding, silage, 

milking (dairy), housing, waste management, and waste storage/application.253 According to the District, 

although Rule 4570 was developed to limit VOC emissions, the work practice standards contained in the 

rule also reduce ammonia emissions – for example through mitigation measures for nutritional 

management, increased cleaning and removal of manure and litter from housing areas, and land 

incorporation of manure and litter.254 The EPA approved Rule 4570 into the California SIP on January 

17, 2012.255

The District compared the requirements of Rule 4570 with those in analogous prohibitory rules 

implemented in other areas, including the South Coast, Bay Area, Sacramento Metro, Ventura County, 

Imperial County, and the State of Idaho, and concluded that Rule 4570 is more stringent than all of these 

rules.256 For example, Rule 4570 contains applicability thresholds that are more stringent than those in 

analogous rules implemented in the South Coast (Rule 233) and Idaho (Rule 58.01.01).257 We note that 

it is difficult to directly compare the requirements among these rules because of the widely varying rule 

structures and operations of confined animal facilities. 

 

251 Id. at Chapter 8, Section 8.2, p. 8-3. 

252 SJVUAPCD, “Draft Further Study, Warm Mix Asphalt,” December 1, 2015. 

253 See generally Rule 4570, as amended October 21, 2010; see also 2015 PM2.5 Plan, Appendix C, pp. C-240. 

254 2015 PM2.5 Plan at Appendix C, p. C-241. 

255 77 FR 2228 (January 17, 2012). 

256 2015 PM2.5 Plan at Appendix C, pp. C-236 to C-267. 

257 Id. 
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The District also considered the technical and economic feasibility of alternative control 

techniques for CAFs, including episodic application of sodium bisulfate (SBS) on manure at dairies, 

which converts a greater fraction of ammonia to non-volatile ammonium.258 Given the costs of SBS 

application and its potential adverse impacts on worker safety and health, cattle health, and water 

quality, the District concluded that SBS application this control option is not technically and 

economically feasible for implementation in the SJV at this time.259 The District also evaluated the use 

of covers to reduce ammonia from lagoons and solid manure storage piles and found no definitive 

evidence that such techniques would reduce ammonia emissions. To the contrary, the District stated, 

several studies indicated that anaerobic lagoon covers might increase ammonia emissions.260

Compost Operations

SJVUAPCD Rule 4565 (“Biosolids, Animal Manure, and Poultry Litter Operations”), as adopted 

March 15, 2007, establishes requirements for facilities that landfill, land apply, compost, or co-compost 

biosolids, animal manure, or poultry litter.261 SJVUAPCD Rule 4566 (“Organic Material Composting”), 

as adopted August 18, 2011, establishes requirements for facilities that stockpile and compost 

greenwaste and foodwaste materials.262 According to the District, although both of these rules were 

designed to control VOC emissions, both rules establish work practice standards that have the co-benefit 

of reducing ammonia emissions.263 The EPA approved Rules 4565 and 4566 into the California SIP on 

January 17, 2012264 and November 29, 2012,265 respectively.

 

258 Id. at pg. C-267. 

259 Id. 

260 E-mail dated June 25, 2015, from Sheraz Gill, SJVUAPCD to Andy Steckel, EPA, re: Requested Information, and 

attachments. 

261 See generally SJVUAPCD Rule 4565, as adopted March 15, 2007; see also 2015 PM2.5 Plan, Appendix C, pp. C-276. 

262 See generally SJVUAPCD Rule 4566, as adopted August 18, 2011; see also 2015 PM2.5 Plan, Appendix C, pp. C-272. 

263 2015 PM2.5 Plan, Appendix C, pp. C-272 and C-276. 

264 77 FR 2228 (January 17, 2012). 

265 77 FR 71129 (November 29, 2012). 
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The District compared the requirements of Rule 4565 and Rule 4566 with those in an analogous 

prohibitory rule implemented in the South Coast area (Rule 1133.2) and found that the SCAQMD rule 

requires in-vessel composting with 70% to 80% control efficiency for existing and new facilities, 

respectively, while SJVUAPCD Rule 4565 requires 10% to 80% control efficiency based on annual 

throughput.266 According to the District, however, the lower control efficiencies required by 

SJVUAPCD Rule 4565 are appropriate because in-vessel composting is not cost-effective for smaller or 

medium-sized facilities, and SCAQMD does not regulate any facilities of the size that is subject to the 

80% control requirement.267 Moreover, the District states that Rule 4565 contains a more stringent 

applicability threshold (100 tpy of biosolids, animal manure or poultry litter) compared to the 

applicability threshold in SCAQMD Rule 1133.2 (1,000 tpy VOC).268

The District also considered the technical and economic feasibility of alternative control 

techniques for compost operations, including finished compost covers and water systems, but found that

these control techniques are not technically and economically feasible for compost operations in the SJV 

at this time.269 The District also noted that it has funded a project through its Technology Advancement 

Program that could potentially reduce ammonia and other emissions at large greenwaste and/or 

foodwaste composting facilities – specifically, an “extended aerated stack pile (eASP) method” which 

substitutes diesel-powered loaders with electronic conveyor systems to build piles, uses solar-powered

blowers to replace diesel-powered windrow turners, and uses finished compost biofilter covers.270

According to the District, the study authors note that this demonstration project is the first test of this 

 

266 2015 PM2.5 Plan, Appendix C at pp. C-272, C-273. 

267 Id. 

268 Id. 

269 Id. at pp. C-275 to C-276 and C-279. 

270 2015 PM2.5 Plan, Appendix E, p. E-15.
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technology and recommend further testing and evaluation to assure results on an industry-wide basis.271

We note that there are other environmental benefits associated with composting operations, including 

diversion of material from landfills, which should be considered in evaluating the feasibility of 

additional controls for this source category. 

b. State Measures for Mobile Sources 

CARB’s BACM and MSM demonstration for mobile sources is in Appendix D of the 2015 

PM2.5 Plan. CARB has primary responsibility for reducing emissions in California from new and 

existing on-road and off-road engines and vehicles, motor vehicle fuels, and consumer products. Given 

the need for significant emissions reductions from mobile sources to meet the NAAQS in California 

nonattainment areas, CARB has been a leader in the development of stringent control measures for onroad and off-road mobile sources, fuels and consumer products.272

 

Under the Clean Air Act, the EPA is charged with establishing national emission limits for 

mobile sources. States are generally preempted from establishing such limits except for California, 

which can establish these limits subject to EPA waiver or authorization under CAA section 209 (referred 

to herein as “waiver measures”). Over the years, the EPA has issued waivers (for on-road vehicles and 

engines measures) or authorizations (for non-road vehicle and engine measures)273 for many mobile 

source regulations adopted by CARB.274 California attainment and maintenance plans, including the 

 

271 Id. 

272 The Plan does not address CARB’s consumer products program because it is primarily designed to reduce emissions of 

VOCs, which the State has excluded from its control strategy for attaining the PM2.5 NAAQS in the SJV. 

273 California regulations use the term “off-road” to refer to “nonroad” vehicles and engines. 

274 The Clean Air Act assigns mobile source regulation to EPA through title II of the Act and assigns stationary source 

regulation and SIP development responsibilities to the states. In so doing, the CAA preempts various types of state regulation 

of mobile sources as set forth in section 209(a)(preemption of state emissions standards for new motor vehicles and engines), 

section 209(e) (preemption of state emissions standards for nonroad vehicles and engines), and section 211(c)(4)(A) 

[preemption of state fuel requirements for motor vehicles, i.e., other than California’s motor vehicle fuel requirements – see

section 211(c)(4)(B)]. For certain types of mobile source standards, the State of California may request a waiver or 

authorization for state emission standards. 
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2015 PM2.5 Plan for the SJV, rely on emissions reductions from implementation of the waiver measures 

through the use of emissions models such as EMFAC2014. 

 Historically, California has not submitted, and the EPA has not required that California submit, 

its mobile source rules that have been granted a waiver or authorization by the EPA for inclusion in the 

California SIP. However, a recent decision by the Ninth Circuit Court of Appeals held that the EPA’s 

longstanding practice in this regard was at odds with the CAA requirement that state and local emissions 

limits relied upon to meet the NAAQS be enforceable by the EPA or private citizens through adoption 

and approval of such limits in the SIP.275

In response to the Court’s ruling, CARB has submitted its mobile source control rules that have 

been granted waivers or authorizations but have not been included in the SIP, and, in a separate 

rulemaking, the EPA has proposed to approve these rules into the SIP.276 Upon the EPA’s final approval 

of these rules into the SIP, which the EPA intends to complete before or concurrent with final action on 

the 2015 PM2.5 Plan, the measures will be enforceable by the EPA or private citizens under the CAA. 

 

 CAA section 209(b)(1) and (e)(2) give California unique authority under the CAA to regulate emissions from new 

motor vehicles and nonroad engines, except for locomotives and engines used in farm and construction equipment less than 

175 horsepower. To exercise its authority, California must obtain a waiver from EPA demonstrating that the standards, in the 

aggregate, are at least as protective of public health and welfare as applicable federal standards. Additionally, EPA must grant 

a waiver unless California’s ‘‘protectiveness determination’’ is arbitrary and capricious; California does not need the 

standards to meet compelling and extraordinary conditions; or California’s standards and accompanying enforcement 

procedures are not consistent with CAA §202(a). EPA has previously stated that consistency with section 202(a) requires that 

California’s standards must be technologically feasible within the lead time provided, giving due consideration of costs. See, 

e.g., 74 FR 32767 (July 8, 2009) regarding the greenhouse gas waiver. Once a waiver is granted, compliance with 

California’s new motor vehicle or engine standards is treated as compliance with applicable federal standards. In the absence 

of a waiver, the applicable federal mobile source standards apply. 

275 Committee for a Better Arvin v. EPA, 786 F.3d 1169 (9th Cir. 2015). 

276 80 FR 69915 (November 12, 2015). 
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In addition to waiver measures, CARB has adopted operational requirements for in-use vehicles, 

rules that limit the amounts of pollutants allowed in transportation fuels, and incentive programs that 

provide funding to replace or retrofit older, dirtier vehicles and equipment with cleaner technologies.

277

 

The EPA previously determined that California’s mobile source control programs constituted 

BACM for PM10 purposes in the San Joaquin Valley.278 Since then, the State has adopted additional 

mobile source control measures including the Advanced Clean Cars program, heavy-duty vehicle idling 

rules, revisions to the State’s vehicle inspection and maintenance (I/M) program, in-use rules for on-road 

and non-road diesel vehicles, and emissions standards for non-road equipment, farm and cargo handling 

equipment, and recreational vehicles.279 

CARB’s BACM and MSM analysis provides a discussion of the measures adopted and 

implemented for each of the identified source categories. We discuss each of these mobile source 

categories below. 

Light and Medium Duty Vehicles 

This category includes light-duty passenger cars, light-duty trucks, and medium-duty trucks. The 

source category’s emissions are 32.2 tpd NOx and 1.9 tpd direct PM2.5.

280

CARB has a long history of adopting programs for reducing emissions from this source category. 

Light-duty and medium-duty motor vehicles are currently subject to California’s “Low-Emission 

Vehicle III” (LEV III) standards as well as a “Zero Emission Vehicle” (ZEV) requirement. The LEV III 

standards are consistent, or harmonized, with the subsequently adopted national Tier 3 standards for the 

 

277 2015 PM2.5 Plan, Appendix D, pp. D-9 to D-11. 

278 69 FR 5412 at 5419 (February 4, 2004). 

279 2015 PM2.5 Plan, Appendix D, pages D-4 to D-19. 

280 2015 PM2.5 Plan, Appendix D, p. D-5. 
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same vehicles. California’s ZEV program, however, does not have a national counterpart and results in 

additional emissions reductions as it phases in a requirement that 15% of new light-duty vehicle sales

consist of ZEV or partial ZEV.281 Taken as a whole, California’s standards for light and medium-duty 

vehicles are more stringent than the federal standards. 

California has also adopted regulations for gasoline fuel (California Reformulated Gasoline or 

CaRFG) which reduce emissions from light-duty and medium-duty vehicles. On July 10, 2009, the EPA 

approved the CaRFG regulations into the California SIP.282

 

Heavy-Duty Vehicles 

This category includes heavy-duty gas and diesel trucks, heavy-duty gas and diesel urban buses, 

school buses and motor homes. The emissions from this category are 130.6 tpd NOx and 4.8 tpd direct 

PM2.5.

283

California has the most stringent heavy-duty vehicle emissions control measures in the nation, 

including engine standards for diesel and gasoline vehicles, idling requirements, certification 

procedures, on-board diagnostic requirements, and verification measures for emissions control devices.

Many of these control measures are subject to the CAA waiver process and have also been submitted for 

inclusion in the SIP.284

California has also adopted many in-use requirements to help reduce emissions from the vehicles 

already on the road, which may remain in use for many years. The most recently adopted in-use 

requirement is the Cleaner In-Use Heavy-Duty Trucks measure (“Truck and Bus Regulation and 

 

281 78 FR 2112 at 2119 (January 9, 2013). 

282 74 FR 33196 (July 10, 2009). 

283 2015 PM2.5 Plan, Appendix D, p. D-8. 

284 2015 PM2.5 Plan, Appendix D, p. D-8 to D-12. See also 80 FR 69915 (November 12, 2015). 
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85 

Drayage Truck Regulation”), which became effective in 2011 and the EPA approved into the SIP in 

2012.285 The Truck and Bus Regulation and Drayage Truck Regulation are designed to reduce emissions 

of diesel particulate matter, NOx, and other pollutants from in-use trucks and buses and establish, among 

other things, phased-in PM control requirements from 2014 through 2023. 

Finally, California has adopted regulations for diesel fuel that further reduce emissions from 

heavy-duty trucks. The EPA approved these diesel fuel regulations into the California SIP on July 10, 

2009.286

Off-Road Vehicles and Engines 

 This category includes off-road compression ignition (diesel) engines and equipment, small 

spark ignition (gasoline) off-road engines and equipment less than 25 horsepower (hp) (e.g., lawn and 

garden equipment), off-road large gasoline engines and equipment greater than 25 hp (e.g., forklifts, 

portable generators), and airport ground service equipment. The emissions from this category total 19.2 

tpd NOx and 1.1 tpd direct PM2.5.

287

 As it has done for the on-road categories discussed above, CARB has adopted stringent new 

emissions standards subject to EPA authorization under CAA section 209(e) and in-use measures or 

requirements for this source category (e.g., incentives for early introduction of cleaner engines and 

equipment and requirements to limit vehicle idling). CARB has been regulating off-road equipment 

since the 1990s and its new engine standards for off-road vehicles and engines are generally as stringent 

as the corresponding federal standards. For larger off-road equipment, which can have a slow turnover 

 

285 77 FR 20308, April 4, 2012. 

287 2015 PM2.5 Plan, Appendix D, pp. D-12 to D-14. 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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rate, CARB adopted an in-use off-road regulation in 2007 that requires owners of off-road equipment in

the construction and other industries to retrofit or replace older engines/equipment with newer, cleaner 

models. The off-road regulation also imposes idling limitations.288

 

Farm Equipment 

 The farm equipment category includes agricultural equipment such as tractors, harvesting 

equipment and sprayers. The category’s emissions are 50.4 tpd NOx and 2.9 tpd PM2.5. CARB has 

adopted standards identical to the EPA’s standards for this off-road engine category. CARB notes also 

that State, District, and federal incentive funds have resulted in the replacement of over 3,000 pieces of 

agricultural equipment earlier than required by state and federal regulations.289

Other Mobile Source Categories 

Other mobile source categories identified by CARB in the Plan include cargo handling 

equipment, motorcycles, recreational boats, off-road recreational vehicles and commercial harbor craft. 

The emissions from all of these categories total 3.5 tpd NOx and 0.5 tpd direct PM2.5. Although CARB 

considers these categories “insignificant” for BACM purposes in the 2015 PM2.5 Plan, CARB provided a 

discussion of the emission standards and other measures it has adopted to control emissions from these

categories.290 

c. Local Jurisdiction Transportation Control Measures (TCMs) 

TCMs are, in general, measures designed to reduce emissions from on-road motor vehicles 

through reductions in vehicle miles traveled or traffic congestion. TCMs can reduce PM2.5 emissions in 

both the on-road motor vehicle exhaust and paved road dust source categories by reducing vehicle miles

 

288 Id.

289 2015 PM2.5 Plan, Appendix D, pp. D-15. 

290 2015 PM2.5 Plan, Appendix D, pp. D-15 to D-18. 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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traveled (VMT) and vehicle trips. They can also reduce vehicle exhaust emissions by relieving 

congestion. EPA guidance states that where mobile sources contribute significantly to PM2.5 violations, 

“the state must, at a minimum, address the transportation control measures listed in CAA section 108(f) 

to determine whether such measures are achievable in the area considering energy, environmental and 

economic impacts and other costs.”291 

The current efforts by the SJV’s eight local jurisdiction metropolitan planning organizations 

(MPO)292 to implement cost-effect transportation control measures (TCM) are described in Chapter 

6.5.6 of the 2015 PM2.5 Plan.293 The Plan includes a discussion of the on-going implementation of a 

broad range of TCMs in the Valley. There is also a discussion of the MPOs’ Congestion Management 

and Air Quality (CMAQ) funding policy, which is a standardized process across the Valley for 

distributing 20% of the CMAQ funds to projects that meet a minimum cost-effectiveness.294 

Each Valley MPO is required to update its Regional Transportation Plan (RTP) at least once 

every four years.295 The RTP is a long-term regional transportation plan that provides a vision for 

transportation investments throughout the Valley. To further illustrate the eight SJV MPOs’ 

commitment to the implementation of TCMs, the RTPs contain a host of improvements to the regional 

multimodal transportation system including: active transportation (e.g., biking and walking), 

transportation demand management, transportation system management, transit, passenger rail, goods 

movement, aviation and airport ground access, highways, arterials, and operations and maintenance. 

 

291 Addendum at 42013. 

292 These eight MPOs represent the eight counties in the San Joaquin Valley air basin: the San Joaquin Council of 

Governments, the Stanislaus Council of Governments, the Merced County Association of Governments, the Madera County 

Transportation Commission, the Council of Fresno County Governments, Kings County Association of Governments, the 

Tulare County Association of Governments and Kern Council of Governments. 

293 2015 PM2.5 Plan, Chapter 6.5.6, p. 6-19. 

294 For an example of the CMAQ funding policy implemented by the eight SJV MPOs, see “Resolution To Adopt The Local 

Cost-Effectiveness Congestion Mitigation And Air Quality (CMAQ) Program Policy,” San Joaquin Council Of Governments 

(SJCOG), R-08-03, July 26, 2007,” and “Exhibit A, Local Cost-Effectiveness CMAQ Policy,” SJCOG. 

295 23 CFR 450.322(c) 
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Included within these transportation system improvements are TCM projects that reduce vehicle use or 

change traffic flow or congestion conditions, such as: improved transit, high occupancy vehicle lanes,

traffic flow improvements, park and ride lots, ridesharing/trip reduction programs, and 

bicycle/pedestrian facilities.296 These projects are listed in each MPO’s conformity analysis for the 2014 

RTP and 2015 Federal Transportation Improvement Program (FTIP).297 The FTIP is a four-year 

spending plan that lists every transportation project that will receive federal funds or that is subject to a 

federally required action, such as a review and approval of environmental documents. 

The SJV has a long history of adopting and then enhancing programs to reduce emissions from 

on-road motor vehicles by reducing vehicle miles traveled, vehicle trips, and/or congestion. For 

example, Rule 9410 (“Employer Based Trip Reduction” or “eTRIP”), requires larger employers to 

establish an Employer Trip Reduction Implementation Plan to encourage employees to reduce singleoccupancy vehicle trips, thus reducing emissions, including PM2.5 and NOx, associated with work 

commutes.298 The MPOs implement public outreach programs to encourage people to reduce driving, 

programs to improve bicycling and pedestrian travel, and an extensive program to synchronize traffic 

lights. 

In our approval of California’s Serious area plan for the 1987 PM10 NAAQS in the SJV299

(“2003 PM10 Plan”), we determined that the measures in the “Regional Transportation Planning Agency 

 

296 See, e.g., Fresno Council of Government’s Conformity Analysis for 2014 RTP and Sustainable Community Strategy, 

adopted June 26, 2014, Appendix D, Timely Implementation Documentation for Transportation Control Measures. The 2014 

RTP is combined with the Sustainable Communities Strategy to integrate land use and transportation planning to achieve, 

where feasible, regional greenhouse gas (GHG) targets set by the CARB pursuant to Senate Bill 375, which identifies 

specific GHG reduction goals for each of California’s MPOs in 2020 and 2035. 

297 Id.

298 EPA, Final rule, “Approval and Promulgation of Implementation Plans; California; San Joaquin Valley Unified Air 

Pollution Control District; Employer Based Trip Reduction Programs,” pre-publication notice signed December 11, 2015; see 

also 80 FR 51153 (August 24, 2015) (proposed rule). 

299 SJVUAPCD, “2003 PM10 Plan, San Joaquin Valley Plan to Attain Federal Standards for Particulate Matter of 10 Microns 

and Smaller,” submitted August 19, 2003 as amended by subsequent submission of December 30, 2003. 
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Commitments for Implementation Document” (April 2002)300 satisfied the PM10 BACM requirement for 

TCMs.301 In May 2003, the San Joaquin Valley MPO Executive Directors committed to conduct 

feasibility analyses as part of each successive RTP in support of the 2003 PM10 Plan. The MPOs 

retained this commitment in the PM10 maintenance plan for the SJV area adopted September 20, 

2007.302 In accordance with their commitment and in preparation for their 2014 RTPs, the MPOs 

reviewed several PM10 Plans adopted in other areas since 2009.303 From their reviews, the MPOs 

concluded no additional on-road fugitive dust controls measures were available for consideration. In 

consultation with CARB and the District, however, the MPOs considered priority funding allocations in 

the 2014 RTPs for PM10 and NOx emission reduction projects for the measures listed below. 

• Paving or Stabilizing Unpaved Roads and Alleys 

• Curbing, Paving, or Stabilizing Shoulders on Paved Roads 

• Frequent Routine Sweeping or Cleaning of Paved Roads (i.e., funding allocation for the purchase 

of PM10 efficient street sweepers for member jurisdictions); and 

• Repave or Overlay Paved Roads with Rubberized Asphalt.304

In their implementation of the Congestion Mitigation and Air Quality (CMAQ) Improvement 

Program, the SJV MPOs evaluate and prioritize the reduction of PM10 emissions in the CMAQ scoring 

criteria. The MPOs continue to implement the adopted San Joaquin Valley CMAQ Policy, which was 

 

300 SJVUAPCD, “Regional Transportation Planning Agency Commitments for Implementation Document,” April 2002. 

301 69 FR 30006 at 30020, 30035 (May 26, 2004). 

302 SJVUAPCD, “2007 PM10 Maintenance Plan and Request for Redesignation,” submitted November 16, 2007. Chapter 7, p. 

21. 

303 PM10 Plans reviewed included: Puerto Rico, Municipality of Guaynabo, PM10 Limited Maintenance Plan; Nogales, AZ, 

PM10 Attainment Demonstration; Coso Junction, CA, PM10 Maintenance Plan, May 17, 2010; Sacramento, CA, PM10

Implementation/Maintenance Plan, October 28, 2010; Truckee Meadows, NV, PM10 Maintenance Plan, May 2009; and Eagle 

River, AK, PM10 Maintenance Plan, adopted August 2010. 

304 See, e.g., Fresno Council of Government’s Conformity Analysis for 2014 RTP and Sustainable Community Strategy, 

adopted June 26, 2014, Chapter 4, Section E, p. 42.
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included in the District’s plan for the 1997 ozone NAAQS305 and the 2008 PM2.5 Plan. The CMAQ 

policy includes a standardized process for distributing 20% of the CMAQ funds to projects that meet a 

minimum cost effectiveness beginning in fiscal year 2011. This policy focuses on achieving the most 

cost effective emissions reductions, while maintaining flexibility to meet local needs. The 2015 FTIP 

includes a listing of all transportation-related projects requiring federal funding or other approval by the 

federal transportation agencies. The aggregate funding allocated306 for TCMs in the eight SJV 2015 

FTIPs includes: 

• improved transit; ($928,000,000) 

• traffic flow improvements ($499,381,000) 

• park and ride lots; ($2,666,346) 

• ridesharing/trip reduction programs; ($7,630,000) 

• bicycle/pedestrian facilities ($6,650,000) 

3. Conclusion 

Based on all of these evaluations, we propose to find that the 2015 PM2.5 Plan provides for the 

implementation of BACM and MSM for sources of direct PM2.5 and PM2.5 precursors as expeditiously 

as practicable, in accordance with the requirements of CAA sections 189(b)(1)(B) and 188(e). 

E. Extension of Serious Area Attainment Date under CAA Section 188(e) 

 

305 SJVUAPCD, “2007 Ozone Plan,” April 30, 2007, which EPA approved on March 1, 2012. (78 FR 12652). 

306 Source: 2015 PM2.5 Plan, Chapter 6, Figure 6-2 Illustration of Valley MPO Funding for Sample TCM Categories, p. 6-20. 

The funding in the 2015 FTIPs covers the federal fiscal years (i.e., October 1 – September 30) 2014/2015 through 2017/2018. 

An example 2015 FTIP, the 2015 Federal Transportation Improvement Program, Fresno Council of Governments, is 

included in the docket for today’s action and available at 

http://www.fresnocog.org/sites/default/files/publications/FTIP/2015_FTIP/FINAL_2015_FTIP_8-13-14.pdf. 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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 Section 188(e) of the Act allows the EPA to extend the attainment date for a serious area for up 

to five years if attainment by the applicable date is impracticable. However, before we may grant an 

extension of the attainment date, the State must first: 

1) apply to the EPA for an extension of the PM2.5 attainment date beyond 2015, 

2) demonstrate that attainment by 2015 is impracticable, 

3) have complied with all requirements and commitments applying to the area in its implementation 

plan, 

4) demonstrate to our satisfaction that its serious area plan includes the most stringent measures that 

are achieved in practice in any state and are feasible for the area, and 

5) submit SIP revisions containing a demonstration of attainment by the most expeditious 

alternative date practicable. 

We evaluate the 2015 PM2.5 Plan’s compliance with each of these requirements below. 

1. Application for an Attainment Date Extension 

As discussed in section IV.D of this proposed rule, for the SJV, the Serious area attainment date 

for the 1997 PM2.5 NAAQS under CAA section 188(c)(2) is December 31, 2015. The first criterion of an 

extension of the attainment date beyond this statutory attainment date is that the State must apply for 

such extension. In the 2015 PM2.5 Plan, CARB and SJVUAPCD submit a complete application for an 

extension of the Serious area attainment date for the SJV to December 31, 2020 for the 1997 annual 

PM2.5 standard and to December 31, 2018 for the 1997 24-hour PM2.5 standard.307

2. Demonstration that Attainment by Serious Area Attainment Date is Impracticable 

 

307 2015 PM2.5 Plan: CARB Resolution 15-9, May 21, 2015 (submitting the Plan to EPA as a SIP revision); SJVAPCD, 

Governing Board Resolution 15-4-7A, paragraph 1 (adopting the 2015 PM2.5 Plan); and Chapter 4, p. 4-1. 
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Despite the implementation of BACM as expeditiously as practicable, as discussed in section 

V.D. above, the 2015 PM2.5 Plan shows that attainment by the Serious area attainment date is 

impracticable. We discuss below the air quality data that support the State’s and District’s demonstration 

of impracticability. 

Chapter 4, Section 4.1 of the 2015 PM2.5 Plan presents data showing that the SJV area cannot 

attain the 1997 PM2.5 annual and 24-hour standards by December 31, 2015.308 Specifically, the District 

provided ambient PM2.5 air quality data from monitoring sites in the SJV, including 2013 measured 

concentrations and 2014 measured and estimated concentrations, and then calculated the maximum 2015 

annual average and 24-hour concentrations for each monitoring site that would result in a 3-year average 

PM2.5 concentration of 15.0 μg/m3

 (i.e., annual design value), and 3-year average 98th percentile 

concentration of 65 μg/m3 (i.e., 24-hour design value), at each monitoring site. The District states that 

several of the maximum allowable 2015 concentrations are so low, and in one instance a negative 

number, that attaining the standards by December 31, 2015 is impracticable.309 A separate analysis is 

presented for the annual and 24-hour standards and we have evaluated each with respect to 

demonstrating impracticability of attaining the 1997 PM2.5 NAAQS. 

The annual average value for a given year is calculated using the quarterly average 

concentrations for that year, while the 24-hour value for a given year is calculated using the 98th

percentile of 24-hour average concentrations for that year.310 At the time the District compiled 

monitoring data for this purpose in January 2015, actual PM2.5 measurements were available for 2013 

and most of 2014 from the EPA’s Air Quality System (AQS) database. For the remainder of the 2014 

 

308 2015 PM2.5 Plan, Chapter 4, pp. 4-1 to 4-5. 

309 Id. at pp. 4-3 to 4-5. 

310 40 CFR 50, Appendix N, sections 4.4 and 4.5, respectively. 
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data, preliminary monitoring measurements were used for the latter portion of 2014 and, for four of the 

16 monitors used in the analysis, the District used 2013 4th quarter data for the 2014 4th quarter data, 

since the 2014 filter data from those monitors were not yet available.311

Impracticability of Attaining the 1997 Annual PM2.5 Standard by December 31, 2015 

According to the District, the maximum 2015 annual average concentration at the BakersfieldPlanz site (which recorded the area’s highest annual average in 2013, and is estimated to have the 

highest annual average in 2014) that will enable the site to show a design value at or below 15.0 μg/m3 

for 2015 is negative 2.4 μg/m3.

312 In addition, the District calculates that the Hanford, Visalia-Church, 

and Bakersfield-California monitoring sites (which are in the three southern-most counties in the SJV)

would have to each average under 10 μg/m3, and states that such concentrations are unlikely given 

historical PM2.5 concentrations in the SJV.313 Based on these preliminary data and analyses, the 2015 

PM2.5 Plan concludes that it is impracticable for the Hanford, Visalia-Church, Bakersfield-California, 

and Bakersfield-Planz monitoring sites, to show an annual PM2.5 NAAQS design value at or below 15.0 

μg/m3

 by December 31, 2015. 

The EPA independently evaluated 2013 and 2014 PM2.5 air quality data that had been uploaded 

to AQS as of June 30, 2015, and as of January 20, 2016, to assess the District’s representations.314 Table 

4 shows the annual average PM2.5 concentrations that were recorded in 2013 and 2014 and that the EPA 

estimated for 2015 at selected monitoring sites. The average annual concentrations in 2013 and 2014 

were higher than in 2012, and in several cases the 2013 and 2014 values were significantly higher than

 

311 2015 PM2.5 Plan, Chapter 4, Table 4-1, p. 4-4. 

312 Id. 

313 Id. at p. 4-4. 

314 See Section III (“Analysis of Practicability of Attainment”) and Appendix A (“Data Worksheets for Analysis of 

Practicability of Attainment”) of the EPA’s General TSD. 
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the 2012 value, especially at the Bakersfield-Planz monitoring site, whose annual average concentrations 

for 2013 and 2014 were each over 20 μg/m3.

315 Based on the annual average concentrations observed in 

2013 and 2014, the EPA calculated the maximum annual average concentration for seven monitoring 

sites that would enable each site to show a 2015 annual average PM2.5 design value at or below 15.04 

μg/m3

.

316

The EPA found that four monitoring sites located in the three southern-most counties of the SJV 

would have to have 2015 annual mean concentrations 35% or more below their corresponding historical 

lows in order to attain by the end of 2015.317 The most extreme example is the Bakersfield-Planz Rd. 

monitoring site, which would require approximately 95% below the previously recorded low. 

Table 4. 2013 and 2014 Annual Average PM2.5 Concentrations (in μg/m3) for Selected Sites in SJV 

and Calculation of Annual Average Maximum to Attain in 2015 

Annual 

Average in 

2013a

Annual 

Average in 

2014a

EPA Estimate 

for Max. 2015 

Annual 

Average 

Allowed to 

Attain b

Lowest 

Recorded 

Annual 

Average 

1999-2014 

(year) b

Max. 2015 % 

Below Lowest 

Recorded 

Annual 

Average 

Hanford 18.18 17.47 9.47 14.79 (2012) 36% 

Visalia 18.90 17.88 8.34 13.58 (2010) 39% 

Bakersfield –

California 19.95 18.55 6.62 13.03 (2012) 49% 

 

315 The 2015 PM2.5 Plan cites weather conditions associated with the extreme drought in California, including low 

precipitation, high stagnation, and strong inversions, among the reasons for the high PM2.5 concentrations observed in the 

winter of 2013-2014. See 2015 PM2.5 Plan, Chapter 4, pp. 4-2 to 4-3 and 4-5. 

316 The small differences between the District’s and EPA’s calculations of “maximum 2015” values are due to EPA’s use of 

certified, rather than preliminary, 2014 data and different rounding conventions. EPA’s calculations of maximum 2015 values 

are based on the rounding convention in 40 CFR part 50, appendix N, which provides that intermediate calculations are not 

rounded, and that a design value with a decimal lower than 15.05 μg/m3

 is rounded down to 15.0 μg/m3. See 40 CFR part 50, 

appendix N, section 4.3. In computing the maximum 2015 concentration consistent with attainment and consistent with 2013 

and 2014 annual mean concentrations, EPA did not round the 2013 and 2014 means in the intermediate steps of the 

calculation, and used 15.04 μg/m3

 as the highest design value consistent with the standard. In contrast, the calculations 

presented in the 2015 PM2.5 Plan rounded the 2013 and 2014 means to one decimal place initially, and used 15.00 μg/m3

 as 

the highest attaining design value. 

317 See section III and Appendix A of the EPA’s General TSD. 
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Bakersfield –

Planz 22.79 21.61 0.72 14.45 (2011) 95% 

a 2014 AQS Design Value Report, AMP480. 

b See Appendix A of the EPA’s General TSD. 

In sum, air quality data for the 2013-2014 period indicate that it is not practicable for the 

Hanford, Visalia-Church, Bakersfield-California, and Bakersfield-Planz monitoring sites to show an 

annual PM2.5 NAAQS design value at or below 15.0 μg/m3

 by December 31, 2015. While our analyses 

resulted in slightly different numbers for the maximum annual average concentrations allowed to attain

for 2015, they are consistent with the analysis and conclusion in the 2015 PM2.5 Plan that attainment is 

impracticable at these sites. As such, we propose to determine that the SJV area cannot practicably attain 

the 1997 annual PM2.5 NAAQS by the applicable attainment date of December 31, 2015. 

Impracticability of Attaining the 1997 24-Hour PM2.5 Standard by December 31, 2015 

According to the District, the maximum 2015 24-hour average PM2.5 concentration at the 

Bakersfield-Planz site (which recorded the area’s highest 24-hour average in 2013 and was estimated to

have recorded the highest 24-hour average concentration in 2014) that will enable the site to show a 

design value at or below 65 μg/m3 for 2015 is 15.9 μg/m3

.

318 In addition, the District states that other 

monitoring sites in the southern portion of the SJV would have to record improbably low 2015 average 

concentrations, of which the lowest are the Hanford and Bakersfield-California sites at 44.6 μg/m3 and 

44.4 μg/m3

, respectively.319 Based on these preliminary data and analyses, the 2015 PM2.5 Plan 

concludes that it is not possible for the Bakersfield-Planz monitoring site, and extremely unlikely for the 

Hanford and Bakersfield-California sites, to show a 24-hour PM2.5 NAAQS design value at or below 65 

μg/m3 by December 31, 2015. 

 

318 2015 PM2.5 Plan, Chapter 4, Table 4-2, p. 4-5. 

319 Id.
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As with the annual standard, the EPA independently evaluated 2013 and 2014 PM2.5 air quality 

data available in AQS as of June 30, 2015, and as of January 20, 2016, to assess the District’s 

representations.320 Table 5 shows the 98th percentile 24-hour average PM2.5 concentrations that were 

recorded in 2013 and 2014 and the maximum concentrations allowed to attain that the EPA estimated 

for 2015 at selected monitoring sites. The 98th percentile 24-hour concentrations in 2013 and 2014 were 

higher than in 2012, and in some cases the 2013 and 2014 values were significantly higher than the 2012 

value, especially at the Bakersfield-Planz monitoring site, whose 98th percentile concentration for 2013 

was over 95 μg/m3

.

321 Based on the 98th percentile values observed in 2013 and 2014, the EPA 

calculated the maximum 98th percentile 24-hour concentration for six monitoring sites that would enable 

the site to show a 2015 24-hour PM2.5 design value at or below 65.4 μg/m3. 

The EPA found that the Bakersfield-Planz monitoring site would have to have a 2015 annual 

mean concentration recorded at 44% below its corresponding historical low in order to attain by the end 

of 2015.322

Table 5. 2013 and 2014 24-hour PM2.5 Concentrations (in μg/m3

) for Selected Sites in SJV and 

Calculation of Maximum 98th Percentile Concentrations for 2015 

98th Percentile 

in 2013a

98th

Percentile in 

2014a

EPA Estimate 

for Max. 

2015 98th

Percentile 

Allowed to 

Attain b

Lowest 

Recorded 98th

Percentile 

1999-2014 

(year) b

Max. 2015 % 

Below Lowest 

Recorded 

Annual 

Average 

Hanford 67.6 81.9 46.7 48.3 (2012) 3% 

Bakersfield –

California 71.8 79.9 44.5 53.3 (2010) 17% 

 

320 See section III and Appendix A of the EPA’s General TSD. 

321 The 2015 PM2.5 Plan cites weather conditions associated with the extreme drought in California, including low 

precipitation, high stagnation, and strong inversions, among the reasons for the high PM2.5 concentrations observed in the 

winter of 2013-2014. See 2015 PM2.5 Plan, Chapter 4, pp. 4-2 to 4-3 and 4-5. 

322 See Appendix A of the EPA’s General TSD. 
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Bakersfield –

Planz 96.7 76.7 22.8 40.6 (2012) 44% 

a 2014 AQS Design Value Report, AMP480. 

b Appendix A of the EPA’s General TSD. 

For these three sites, the EPA’s analysis largely confirms the analysis presented in the 2015 

PM2.5 Plan of the maximum 98th percentile concentration allowed for the SJV to attain the 1997 24-hour 

PM2.5 standard by December 31, 2015 (e.g., EPA estimated maximum is 22.8 μg/m3 at BakersfieldPlanz compared to District estimated maximum of 15.9 μg/m3

, both of which are well below the historic 

low). For the Bakersfield-California site, the estimated maximum 98th percentile concentrations are 17% 

below the historic low, which is quite low, while the estimated maximum 98th percentile concentration at 

Hanford site is not drastically different than its historic low. However, such values would appear very 

unlikely given the 98th percentile values in 2013 and 2014 and do not alter the clear impracticability of 

attaining the 1997 24-hour PM2.5 standard at the Bakersfield-Planz site. 

In sum, air quality data for the 2013-2014 period indicate that it is not practicable for the 

Bakersfield-Planz monitoring site to show an annual PM2.5 NAAQS design value at or below 15.0 μg/m3

by December 31, 2015. While our analysis resulted in slightly different numbers for the maximum 

annual average concentrations for 2015, they are consistent with the Plan’s analysis and conclusion that 

attainment is impracticable at this site. As such, we propose to determine that the SJV area cannot 

practicably attain the 1997 24-hour PM2.5 NAAQS by the applicable attainment date of December 31, 

2015. 

3. Compliance with All Requirements and Commitments in the Implementation Plan 

We interpret this criterion to mean that the State has implemented the control measures and 

commitments in the plan revisions it has submitted to address the applicable requirements in CAA 

sections 172 and 189 for PM2.5 nonattainment areas. For a Serious area attainment date extension request 

being submitted simultaneously with the initial Serious area attainment plan for the area, the EPA 
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proposes to read section 188(e) not to require the area to have a fully approved Moderate area attainment 

plan and to allow for extension of the attainment date if the area has complied with all Moderate area

requirements and commitments pertaining to that area in the State’s submitted Moderate area 

implementation plan. This interpretation is based on the plain language of section 188(e), which requires 

the State to comply with “all requirements and commitments pertaining to [the] area in the 

implementation plan.”323

Between 2007 and 2011, California made six SIP submissions to address nonattainment area 

planning requirements for the 1997 PM2.5 NAAQS in the SJV,324 which we refer to collectively as the 

“2008 PM2.5 Plan.” On November 9, 2011, the EPA approved all elements of the 2008 PM2.5 Plan except 

for the contingency measures, which the EPA disapproved.325 As part of this action, the EPA approved, 

among other things, commitments by CARB and the SJVUAPCD to take specific actions with respect to 

identified control measures and to achieve specific amounts of NOx, SOx, and direct PM2.5 emission 

reductions by 2014.326 In July 2013, the State submitted a revised PM2.5 contingency measure plan for 

the SJV, which the EPA fully approved in May 2014.327

On May 20, 2015, the Ninth Circuit Court of Appeals issued its decision in a challenge to the 

EPA’s November 9, 2011 action on the 2008 PM2.5 Plan.328 In Committee for a Better Arvin et. al v. 

EPA, 786 F.3d 1169 (9th Cir. 2015) (CBA), the court held that the EPA violated the CAA by approving 

the 2008 PM2.5 Plan even though the plan did not include certain state-adopted mobile source emission 

 

323 The Ninth Circuit Court of Appeals upheld this interpretation of section 188(e) in Vigil v. Leavitt, 366 F.3d 1025, 

amended at 381 F.3d 826 (9th Cir. 2004). 

324 76 FR 69896 at n. 2 (November 9, 2011). 

325 Id. at 69924. 

326 Id. at 69926 (codified at 40 CFR 52.220(c)(356)(ii)(B)(2), 52.220(c)(392)(ii)(A)(2), and 52.220(c)(395)(ii)(A)(2)). 

327 79 FR 29327 (May 22, 2014). 

328 Committee for a Better Arvin et al v. EPA, 786 F.3d 1169 (9th Cir. 2015).
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standards on which the plan relied to achieve its emission reduction goals.329 The CBA court remanded 

the EPA’s action on the 2008 PM2.5 Plan for further proceedings consistent with the decision but did not 

vacate the EPA’s action.330 Thus, absent an EPA rulemaking to withdraw or revise the EPA’s November 

2011 approval of the control measure and emission reduction commitments in the 2008 PM2.5 Plan, all 

of these commitments remain enforceable components of the California SIP.331

 

The specific State and District commitments that the EPA approved into the California SIP as 

part of the 2008 PM2.5 Plan are as follows: 

(1) A commitment by the District to “adopt and implement the rules and measures in the 2008 

PM2.5 Plan” in accordance with the timetable specified in Table 6-2 of the 2008 PM2.5 Plan, 

as amended June 17, 2010, and to submit these rules and measures to CARB for transmittal 

to the EPA as SIP revisions;332

(2) A commitment by CARB to propose specific measures identified in Appendix B of the 

“Progress Report on Implementation of PM2.5 State Implementation Plans (SIP) for the South 

Coast and San Joaquin Valley Air Basins and Proposed SIP Revisions,” dated April 28, 2011 

(2011 Progress Report), in accordance with the timetable specified therein;333

 

329 Id. 

330 Id. 

331 As a consequence of the CBA decision, EPA recently proposed to withdraw its May 2014 approval of the District’s PM2.5

contingency measure submission and to disapprove this submission in its entirety. 80 FR 49190 (August 17, 2015). Upon 

EPA’s final withdrawal of this action and disapproval of the PM2.5 contingency measure submission, the measures and 

commitments in this submission will no longer be required components of the California SIP. 

332 40 CFR 52.220(c)(392)(ii)(A)(2), SJVUAPCD Governing Board Resolution No. 08-04-10 (April 30, 2008), and 

SJVUAPCD Governing Board Resolution No. 10-06-18 (June 17, 2010); see also 76 FR 69896 at 69921, Table 1 (November 

9, 2011). 

333 40 CFR 52.220(c)(395)(ii)(A)(2), CARB Resolution No. 07-28, Attachment B (September 27, 2007), CARB Resolution 

No. 09-34 (April 24, 2009), and CARB Resolution No. 11-24 (April 28, 2011); see also 76 FR 69896 at 69921-69922, Table 

2 (November 9, 2011). 
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(3) A commitment by the District to achieve a total of 8.97 tpd of NOx emission reductions, 6.7 

tpd of direct PM2.5 emission reductions, and 0.92 tpd of SOx emission reductions by 2014 as 

described in Table 6-3a, Table 6-3b, and Table 6-3c, respectively, of the 2008 PM2.5 Plan; 

and 

(4) A commitment by CARB to achieve a total of 17.1 tons per day (tpd) of NOx emission 

reductions and 2.3 tpd of direct PM2.5 emission reductions by 2014 as described in CARB 

Resolution No. 07-28, Attachment B, as amended in 2009 and 2011.334 

As of November 9, 2011, the date of the EPA’s final action on the 2008 PM2.5 Plan, CARB and 

the District had each satisfied substantial portions of these control measure and emission reduction 

commitments. Specifically, the District had adopted 12 of the 13 measures that it had committed to 

adopt and implement as part of its control strategy for attaining the PM2.5 standards, leaving one 

additional measure that was scheduled for adoption in 2014 (Rule 4905 (“Natural Gas-Fired, Fan Type 

Residential Central Furnaces”).335 CARB had proposed action on six of the seven measures that it had 

committed to propose for Board consideration as part of its PM2.5 control strategy for the SJV, leaving 

one additional measure that was scheduled for proposal in 2013 (“New Emissions Standards for 

Recreational Boats”).336 Finally, together CARB and the District had achieved all of the SOx emission 

reduction commitments and substantial portions of the direct PM2.5 and NOx emission reduction 

commitments through implementation of State and District control strategy measures, leaving 3.0 tpd of

 

334 40 CFR 52.220(c)(356)(ii)(B)(2). 

335 76 FR 69896 at 69921, Table 1 (“San Joaquin Valley Air Pollution Control District 2008 PM2.5 Plan Specific Rule 

Commitments”). 

336 76 FR 69896 at 69922, Table 2 (November 9, 2011) (“2007 State Strategy Defined Measures Schedule for Consideration 

and Current Status”). 
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direct PM2.5 emission reductions and 12.9 tpd of NOx emission reductions yet to be achieved by the 

beginning of 2014.337

The CARB Staff Report for the 2015 PM2.5 Plan338 contains the State’s demonstration that both 

CARB and the District have satisfied the commitments in the 2008 PM2.5 Plan that remained outstanding 

as of November 9, 2011, as follows. First, on January 22, 2015, the District adopted Rule 4905 and on 

April 7, 2015, CARB submitted this rule to the EPA as a revision to the California SIP.339 Second, on 

February 19, 2015, CARB proposed for Board consideration, and the Board adopted, new emission 

standards for recreational boats entitled “Evaporative Emissions Control Requirements for Spark-Ignited 

Watercraft.”340 These State and District rulemaking actions satisfied the last remaining commitments 

concerning specific control measures in the 2008 PM2.5 Plan. 

With respect to the outstanding emission reduction commitments (also called “aggregate 

commitments”), Tables 9 and 10 of the CARB Staff Report, as amended by CARB’s Technical 

Clarifications, identify nine specific State and District control measures that, according to CARB, 

achieved emission reductions beyond those already credited toward the 2008 PM2.5 Plan and that satisfy 

the State’s remaining 2014 emission reduction obligations. These measures are identified in Table 6. 

Table 6. 2008 PM2.5 Plan Aggregate Commitment – State and District-Identified Measures 

Measure 

2014 Emission Reductions (Annual 

Average tpd) 

NOx Direct PM2.5

Rule 4320 (Advanced Emission Reduction Options for 

Boilers, Steam Generators, and Process Heaters Greater 

than 5.0 MMBtu/hr) 

1.8 0.0 

 

337 Id. at 69923, Table 4 (“Reductions Needed for Attainment Remaining as Commitments Based on SIP-Creditable 

Measures”).

338 2015 PM2.5 Plan, CARB Staff Report, pp. 17-22 and Appendix B.

339 CARB Staff Report, Table 7, p. 19 and letter dated April 7, 2015, from Richard Corey, Executive Officer, CARB, to Jared 

Blumenfeld, Regional Administrator, EPA Region 9 (transmitting air district regulations to EPA as California SIP revisions).

340 CARB Staff Report, Table 8, p. 20; see also http://www.arb.ca.gov/regact/2015/simw2015/simw2015.htm. 
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Rule 9510 (Indirect Source Review) 1.0 0.1 

Woodstove Replacements 0.0 0.1 

District Funded Incentive-Based Emission Reduction 

Measures 1.5 0.1 

Rule 9410 (Employer Based Trip Reduction) 0.3 0.0 

Rule 4901 (Wood Burning Fireplaces and Wood Burning

Heaters) 0.0 1.3 

State Funded Incentive-Based Emission Reduction 

Measures 7.8 0.2 

CARB Cleaner In-Use Heavy Duty Trucks Measure 

11.5 0.1 

CARB Portable Equipment Registration Program (PERP)

and Portable Engine ATCM 2.5 0.2 

Total Emission Reductions 26.4 2.1 

Source: CARB Staff Report, pp. 21, 22 and Technical Clarifications, pp. 2 to 4. 

We have reviewed the State’s demonstration with respect to each of these nine measures and, for 

the reasons provided below, we propose to find that all but one may be credited toward the State’s 

outstanding 2014 emission reduction obligations. 

First, with respect to SJVUAPCD’s Rule 4320 (“Advanced Emission Reduction Options for 

Boilers, Steam Generators, and Process Heaters Greater than 5.0 MMBtu/hr”), also called the “AERO 

Rule,” the EPA approved this rule as adopted October 2008 into the California SIP on March 25, 

2011341 but did not credit the rule with any emission reductions as part of the attainment demonstration 

in the 2008 PM2.5 Plan.342 In the proposal to approve this rule into the SIP, the EPA stated that because 

this rule allows regulated entities to pay a fee in lieu of meeting NOx emission limits, the State would 

 

341 76 FR 16696 (March 25, 2011). 

342 2008 PM2.5 Plan TSD at pp. 93-94, Table F-4 (September 30, 2011); see also CARB Staff Report, Appendix B at p. B-7 

and Table B-8. 
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need to demonstrate that the fee provisions achieve emission reductions that are quantifiable, surplus, 

enforceable, and permanent consistent with EPA guidance before relying on this rule for credit in an 

attainment plan.343

In the CARB Staff Report, the State explained that it now has documentation showing that 

operators of 472 of the units subject to Rule 4320 chose to pay fees and that operators of the remaining 

692 units subject to the rule chose to retrofit their equipment to comply with the NOx emission limits in 

the rule.344 CARB also explained that, based on these enforceable emission limits, the District estimated 

that the operators of the 692 units that did not pay fees had achieved 1.8 tpd of actual NOx emission 

reductions by the beginning of 2014, based on an operating capacity of 50% or 75%.345 We find this 

documentation adequate to credit Rule 4320 with 1.8 tpd of NOx emission reductions toward the State’s 

outstanding 2014 emission reduction obligation. 

Second, with respect to SJVUAPCD’s Rule 9510 (“Indirect Source Review”), the EPA approved 

this rule as adopted December 2005 into the California SIP on May 9, 2011346 but did not credit the rule 

with any emission reductions as part of the attainment demonstration in the 2008 PM2.5 Plan.347 In the 

final rule to approve Rule 9510 into the SIP, the EPA identified a number of concerns about the 

enforceability of the rule’s provisions, e.g., provisions that allow project developers to pay a fee instead 

of implementing on-site pollution mitigation plans, and noted that the State would need to resolve these 

enforceability issues before relying on this rule for credit in an attainment plan.348

 

343 75 FR 68294 at 68295 (November 5, 2010). 

344 CARB Staff Report, Appendix B at p. B-7. 

345 Id. at p. B-8, Table B-8. 

346 76 FR 26609 (May 9, 2011). 

347 2008 PM2.5 Plan TSD at pp. 100-101; see also CARB Staff Report, Appendix B at pp. B-6 and B-7. 

348 76 FR 26609 at 26612-26613 (May 9, 2011). 
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In the CARB Staff Report, the State explained that it now has documentation of the number of 

projects that have complied with the rule through on-site mitigation (instead of payment of a fee) and the 

associated reductions in on-site emissions of NOx and PM10.

349 The project information provided in 

Appendix B-2 of the CARB Staff Report, however, is not adequate for the EPA to determine what types 

of mitigation plans were implemented, to verify that those plans were implemented as proposed, or to 

estimate the associated emission reductions. Furthermore, it is unclear whether the District or any other 

state or local agency is authorized to enforce these mitigation plans. We find this documentation 

insufficient to credit Rule 9510 with any emission reductions toward the State’s outstanding 2014 

emission reduction obligation. 

Third, with respect to wood stove replacements, the CARB Staff Report explains that the District 

implements a voluntary wood stove replacement program that provides funding for residents to replace 

less efficient wood stoves with more efficient gas-burning devices.350 CARB also notes that the District 

has provided a list of wood stoves replaced through this program as of December 31, 2013, together 

with documentation of the calculation methodologies and related emission factors that it used to 

calculate the direct PM2.5 emission reductions achieved by these wood stove replacements.351 All wood 

stoves are installed by a District contracted retailer, with pre- and post- installation photographs 

provided to the District. Old wood or pellet inserts/stoves are removed and surrendered to a licensed 

recycling/dismantling facility within 60 days of installation.352 We find this documentation adequate to 

 

349 CARB Staff Report at p. B-6, B-7 (referencing list of projects in Appendix B-2). 

350 Id. at pp. B-5. 

351 Id. at pp. B-5, B-6 and Appendix B-1. 

352 See SJVAPCD Burn Cleaner Voucher Guidelines, dated December 2014, available at: 

http://valleyair.org/grants/documents/burncleaner/2014/BC_Guidelines.pdf; and SJVAPCD Burn Cleaner Voucher 

Application – Phase 1, dated December 2014, available at: 

http://valleyair.org/grants/documents/burncleaner/2014/BC_VoucherApp.pdf
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credit the District’s wood stove replacement program with 0.1 tpd of direct PM2.5 emission reductions 

toward the State’s outstanding 2014 emission reduction obligation. 

Fourth, with respect to District-funded incentive programs, CARB provided a list of stationary 

and portable agricultural engines and off-road agricultural equipment that were repowered, retrofitted

with controls, or replaced with newer equipment through incentive funds disbursed by the District 

pursuant to the Carl Moyer Memorial Air Quality Standards Attainment Program (Carl Moyer Program). 

Specifically, the CARB Staff Report documents the State’s bases for concluding that a total of 824 

incentive projects implemented in the SJV between January 2009 and December 2013 in accordance 

with specified portions of the Carl Moyer Program Guidelines have achieved a total of 1.8 tons per day

(tpd) of NOx emission reductions and 0.1 tpd of PM2.5 emission reductions in the SJV, which may be 

credited toward the State’s 2014 emission reduction commitment.353 The EPA previously reviewed the 

identified portions of the Carl Moyer Program Guidelines and found that they adequately address the 

EPA’s recommended integrity elements for economic incentive programs.354 We find this 

documentation sufficient to credit these District-funded projects with 1.8 tpd of NOx emission reductions 

and 0.1 tpd of direct PM2.5 emission reductions toward the State’s outstanding 2014 emission reduction 

obligation. 

Fifth, with respect to SJVUAPCD’s Rule 9410 (“Employer Based Trip Reduction”), CARB 

submitted this rule as adopted December 2009 to the EPA as a revision to the California SIP on May 17,

 

353 CARB Staff Report, pp. B-9 to B-12; Technical Clarifications at 2-4; and Revised Appendix B-3. 

354 The specified portions of the guidelines that apply to the identified projects are contained in The Carl Moyer Program 

Guidelines, Approved Revision 2005; The Carl Moyer Program Guidelines, Approved Revision 2008; and The Carl Moyer 

Program Guidelines, Approved Revision 2011. See CARB Staff Report at Table B-10. EPA has reviewed these portions of 

the Carl Moyer Program Guidelines and found that they adequately address EPA’s recommended integrity elements for 

economic incentive programs. 79 FR 29327 (May 22, 2014); see also 80 FR 51147 (August 24, 2015). 
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2010, and on December 11, 2015, the EPA fully approved the rule into the SIP.355 Accordingly, the 

emission reductions that the State and District have attributed to this rule (0.3 tpd of NOx emission 

reductions) are creditable toward the State’s outstanding 2014 emission reduction obligation. As part of 

the EPA’s proposed action on Rule 9410, the EPA evaluated the District’s estimates of emission 

reductions achieved by the rule and found the District’s calculations to be technically sound and 

generally consistent with the planning assumptions in the 2008 PM2.5 Plan.356 

Sixth, with respect to SJVUAPCD’s Rule 4901 (“Wood Burning Fireplaces and Wood Burning 

Heaters”), the EPA approved this rule as adopted October 2008 into the California SIP on November 10, 

2009357 and credited the rule with 1.08 tpd of direct PM2.5 emission reductions in 2014 as part of the 

attainment demonstration in the 2008 PM2.5 Plan.358 In the CARB Staff Report, the State explained that

it now has documentation of additional direct PM2.5 emission reductions achieved by this rule based on

an updated methodology for calculating emission reductions from its curtailment program. Specifically,

the District reviewed ambient air quality data for a more recent period (2009-2013) to determine the 

number of “No Burn” days that would have been required under the mandatory curtailment level (30 

μg/m3) in the October 2008 version of Rule 4901. This updated air quality data resulted in a larger 

number of “No Burn” days compared to the District’s prior calculation, which was based on 2006 air 

quality data.359 We find this documentation adequate to credit Rule 4901 with 1.3 tpd of direct PM2.5

emission reductions toward the State’s outstanding 2014 emission reduction obligation. 

 

355 EPA, Final rule, “Approval and Promulgation of Implementation Plans; California; San Joaquin Valley Unified Air 

Pollution Control District; Employer Based Trip Reduction Programs,” pre-publication notice signed December 11, 2015.

356 80 FR 51153 (August 24, 2015). 

357 74 FR 57907 (November 10, 2009). 

358 2008 PM2.5 Plan TSD at p. 93, Table F-4 (September 30, 2011); see also 76 FR 69896 at 69921, Table 1 (November 9, 

2011). 

359 2015 PM2.5 Plan, Technical Clarifications, p. 1; and CARB Staff Report, Appendix B, p. B-7. 
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Seventh, with respect to State Funded Incentive-Based Emission Reduction Measures, CARB 

submitted the “Report on Reductions Achieved from Incentive-based Emission Reduction Measures in 

the San Joaquin Valley” (Emission Reduction Report) to the EPA as a revision to the California SIP on 

November 17, 2014,360 and on August 24, 2015, the EPA proposed to fully approve this report into the 

SIP.361 As part of this proposal, the EPA evaluated the State’s demonstration that specified portions of 

the Carl Moyer Program and Prop 1B Program guidelines adequately address the EPA’s recommended 

integrity elements for economic incentive programs and that the identified projects funded pursuant to

these guidelines achieved 7.8 tpd of NOx emission reductions and 0.2 tpd of direct PM2.5 emission 

reductions by the beginning of 2014.362 Upon final approval of this demonstration into the California 

SIP, these emission reductions would be creditable toward the State’s 2014 emission reduction 

obligation. Thus, final action by the EPA to fully approve the Emission Reduction Report before or 

concurrent with our final action on the 2015 PM2.5 Plan would suffice to credit these state-funded 

projects with 7.8 tpd of NOx emission reductions and 0.2 tpd of direct PM2.5 emission reductions toward 

the State’s outstanding 2014 emission reduction obligation. 

Eighth, with respect to CARB’s Cleaner In-Use Heavy Duty Trucks measure (also called the 

Truck and Bus Regulation and Drayage Truck Regulation), the EPA approved these rules as adopted 

September 2011 into the California SIP on April 4, 2012363 and credited the rules with 1.1 tpd of NOx

emission reductions and 1.7 tpd of direct PM2.5 emission reductions in 2014 as part of the attainment 

demonstration in the 2008 PM2.5 Plan.364 In the CARB Staff Report, the State explained that it now has 

 

360 CARB Staff Report, Appendix B at p. B-2. 

361 80 FR 51147 (August 24, 2015).

362 Id. 

363 77 FR 20308 (April 4, 2012). 

364 2008 PM2.5 Plan TSD, Table F-8, p. 99 (September 30, 2011). 
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documentation of additional NOx and direct PM2.5 emission reductions achieved by these rules by the

beginning of 2014, based on current compliance reports indicating that diesel particulate filters (DPFs) 

are more efficient than original estimates and that a larger than expected number of truck and bus 

owners had purchased new vehicles (which are cleaner than retrofits) rather than installing retrofit 

DPFs.365 We find this documentation adequate to credit CARB’s Cleaner In-Use Heavy Duty Trucks 

measure with 11.5 tpd of NOx emission reductions and 0.1 tpd of direct PM2.5 emission reductions 

toward the State’s outstanding 2014 emission reduction obligation. 

Finally, with respect to CARB’s Portable Equipment Registration Program (PERP) and Portable 

Engine Airborne Toxic Control Measure (Portable Engine ATCM), CARB adopted these programs in 

1997 and 2004, respectively, to reduce pollution by requiring the removal of uncertified engines from 

the registered fleet of nonroad engines operating in California.366 The EPA did not credit either of these 

programs with emission reductions as part of the attainment demonstration in the 2008 PM2.5 Plan.367 On 

December 6, 2012, the EPA granted California’s request for authorization under CAA section 209(e)(2) 

to implement both the PERP and the Portable Engine ATCM.368 On August 14, 2015, CARB submitted 

these measures to the EPA for SIP approval and on November 12, 2015, the EPA proposed to approve 

both measures as revisions to the California SIP.369 Upon final approval of these measures into the SIP, 

their requirements will be federally enforceable and the associated emission reductions will be creditable 

for attainment planning purposes in the SJV. Thus, final action by the EPA to fully approve the PERP 

and the Portable Engine ATCM before or concurrent with our final action on the 2015 PM2.5 Plan would 

 

365 CARB Staff Report, Appendix B, pp. B-2 to B-4. 

366 Id. at pp. B-4, B-5 and Technical Clarifications, p. 3.

367 2008 PM2.5 Plan TSD, Table F-8, p. 99 (September 30, 2011). 

368 77 FR 72846 and 77 FR 72851 (December 6, 2012). 

369 Letter dated August 14, 2015, from Richard W. Corey, Executive Officer, California Air Resources Board, to Jared 

Blumenfeld, Regional Administrator, EPA Region 9, with attachments. 80 FR 69915 (November 12, 2015). 
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suffice to credit these measures with 2.5 tpd of NOx emission reductions and 0.2 tpd of PM2.5 reductions 

toward the State’s outstanding 2014 emission reduction obligation. 

According to the CARB Staff Report, implementation of these control measures resulted in NOx

emission reductions that exceeded the State’s outstanding NOx commitment by 13.9 tpd by the 

beginning of 2014.370 Citing air quality modeling conducted as part of the 2008 PM2.5 Plan, CARB 

stated that a reduction of 9 tpd of NOx emissions provides an air quality improvement equivalent to a 1 

tpd reduction in directly emitted PM2.5. On this basis, CARB concluded that an 8.1 tpd portion of the 

13.9 tpd of surplus NOx reductions achieved through implementation of the identified State and District 

measures adequately covered the small shortfall (0.9 tpd) in required reductions of direct PM2.5.

371

Table 7 identifies the State and District measures that the EPA is proposing to credit toward the 

State’s outstanding 2014 emission reduction obligations, the amount of SIP-creditable emission 

reductions for each measure, and the 9:1 NOx for PM2.5 trading ratio372 calculation that the EPA is 

proposing to accept for this purpose. The total amount of SIP-creditable NOx emission reductions 

associated with the identified control measures (25.4 tpd) exceeds the State’s outstanding NOx emission 

reduction commitment (12.9 tpd) by 12.5 tpd.373 We believe the technical bases for a 9:1 NOx for PM2.5

trading ratio are generally sound and have therefore used this trading ratio to credit the State with 1 

additional tpd of PM2.5 emission reduction (based on 9 tpd of “excess” NOx emission reductions) toward 

its outstanding 2014 commitment. In evaluating the interpollutant trading used for the aggregate 

 

370 CARB Staff Report at pp. 21, 22. 

371 Id. 

372 We use “trading ratio” in this action to refer to the extent to which reductions of one pollutant are substituted for necessary 

reductions of another pollutant. 

373 As explained in this section, we find CARB’s documentation insufficient to credit Rule 9510 with any emission reductions 

toward the State’s outstanding 2014 emission reduction obligation and, therefore, do not entirely agree with CARB’s 

conclusion that it achieved 13.9 tpd of NOx emission reductions in excess of its outstanding commitments. The difference 

between the 25.4 tpd of NOx emission reductions achieved by the control measures identified in Table 7 and the State’s 

outstanding 12.9 tpd NOx emission reduction commitment is 12.5 tpd of “excess” NOx emission reductions. 
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110 

commitments (as well as for Reasonable Further Progress and for Motor Vehicle Emissions Budgets for 

conformity), the EPA considered the regulatory basis for allowing interpollutant trading, 24-hour and 

annual averaging times, the pollutant trading direction, the geographical extent of emissions, the 

conservativeness and the numerical stability of the ratio, and the geographical variation of the trading 

ratio. For further discussion of our evaluation of the 9:1 NOx to PM2.5 trading ratio for purposes of the 

aggregate commitment, please see section IV.C of the EPA’s “Technical Support Document for EPA’s 

Evaluation of Interpollutant Trading Ratios For Fine Particulate Matter Emissions in the San Joaquin 

Valley Air Pollution Control District,” January 2016 (“Interpollutant Trading Ratios TSD”). 

Table 7. 2008 PM2.5 Plan Aggregate Commitment – EPA Proposed Emission Reduction Credits 

for Measures in CARB Compliance Demonstration 

Measure 

2014 Emission Reductions (Annual 

Average tpd) 

NOx Direct PM2.5

Rule 4320 (Advanced Emission Reduction Options for 

Boilers, Steam Generators, and Process Heaters Greater 

than 5.0 MMBtu/hr) 

1.8 0.0 

Rule 9510 (Indirect Source Review) 0.0 0.0 

Woodstove Replacements 0.0 0.1 

District Funded Incentive-Based Emission Reduction 

Measures 1.5 0.1 

Rule 9410 (Employer Based Trip Reduction) 0.3 0.0 

Rule 4901 (Wood Burning Fireplaces and Wood Burning

Heaters) 0.0 1.3 

State Funded Incentive-Based Emission Reduction 

Measures 7.8 0.2 

CARB Cleaner In-Use Heavy Duty Trucks Measure 

11.5 0.1 

CARB Portable Equipment Registration Program (PERP)

and Portable Engine ATCM 2.5 0.2 

Total SIP-Creditable Emission Reductions from State

and District Measures 

25.4 2.0 
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NOx to PM2.5 Emissions Equivalence (9:1) -9.0 1.0 

Total Emission Reductions Achieved 16.4 3.0 

In sum, the CARB Staff Report demonstrates that implementation of State and District measures 

achieved a total of 16.4 tpd of NOx emission reductions and 3.0 tpd of direct PM2.5 emission reductions 

that have not previously been credited as part of the attainment demonstration in the 2008 PM2.5 Plan 

and that may, therefore, be credited toward the State’s outstanding obligation to achieve 12.9 tpd of NOx

emission reductions and 3.0 tpd of direct PM2.5 emission reductions by the beginning of 2014. 

Based on these evaluations, we propose to determine that California has complied with all 

requirements and commitments pertaining to the SJV area in the implementation plan. 

4. Demonstration that the Implementation Plan Includes the Most Stringent Measures 

We interpret this criterion to mean that the State must demonstrate to the EPA’s satisfaction that 

its serious area plan includes the most stringent measures that are included in the implementation plan of 

any state, or achieved in practice in any state, and can feasibly be implemented in the area. 

As discussed above in section V.D, because of the substantial overlap in the source categories 

and controls evaluated for BACM and those evaluated for MSM, we present our evaluation of the 2015 

PM2.5 Plan’s provisions for including MSM alongside our evaluation of the Plan’s provisions for 

implementing BACM for each identified source category. For the reasons provided in section V.D and 

further in the EPA’s SJV Rules TSD, we propose to determine that the 2015 PM2.5 Plan provides for the 

implementation of MSM for sources of direct PM2.5 and PM2.5 precursors as expeditiously as 

practicable, in accordance with the requirement in CAA section 188(e). 

5. Demonstration of Attainment by the Most Expeditious Alternative Date Practicable 
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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 PM2.5 NAAQS by the 

applicable attainment date or, where the State is seeking an extension of the attainment date under 

section 188(e), a demonstration that attainment by that date is impracticable and that the plan provides 

for attainment by the most expeditious alternative date practicable. We discuss below our evaluation of 

the modeling approach in the Plan, the State’s basis for excluding one 24-hour data point from the 

modeling analysis, and the control strategy in the Plan for attaining the 1997 annual and 24-hour PM2.5

NAAQS by the most expeditious alternative dates practicable. 

Evaluation of Air Quality Modeling Approach and Results 

The EPA’s PM2.5 modeling guidance374 (“Modeling Guidance” and “Modeling Guidance 

Update”) recommends that a photochemical model, such as CAMx or CMAQ, be used to simulate a 

base case, with meteorological and emissions inputs reflecting a base case year, to replicate 

concentrations monitored in that year. The model application to the base case year undergoes a 

performance evaluation to ensure that it satisfactorily agrees with concentrations monitored in that year. 

The model may then be used to simulate emissions occurring in other years required for a plan, namely 

the base year (which may differ from the base case year) and future year.375 The modeled response to the 

emission changes between those years is used to calculate Relative Response Factors (RRFs), which are 

applied to the design value in the base year to estimate the projected design value in the future year for 

 

374 “Guidance on the Use of Models and Other Analyses for Demonstrating Attainment of Air Quality Goals for Ozone, 

PM2.5, and Regional Haze,” EPA-454/B-07-002, April 2007 (“Modeling Guidance”); and “Update to the 24 Hour PM2.5

NAAQS Modeled Attainment Test,” Memorandum from Tyler Fox, Air Quality Modeling Group, OAQPS, EPA to Regional 

Air Program Managers, EPA, June 28, 2011 (“Modeling Guidance Update”). 

375 In this section, we use the terms “base case,” “base year” or “baseline,” and “future year” as described in section 3.5 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. See Modeling Guidance at pp. 33-34. Note that CARB sometimes uses “base year” synonymously with “base 

case” and “reference year” instead of “base year.” 
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comparison against the NAAQS. Separate RRFs are estimated for each chemical species component of 

PM2.5, and for each quarter of the year, to reflect their differing responses to seasonal meteorological 

conditions and emissions. Since each species is handled separately, before applying an RRF the base 

year design value must be speciated using available chemical species measurements, that is, each day’s

measured PM2.5 comprising the design value must be split into its species components. The Modeling 

Guidance provides additional detail on the recommended approach.376

The attainment demonstration in the 2015 PM2.5 Plan is based on modeling performed for the 

2008 PM2.5 Plan, but that modeling is used in a streamlined way, by employing scaling. The attainment 

demonstration approach in the 2015 PM2.5 Plan is covered in its Chapter 4 (“Classification and 

Attainment”) and Appendix F (“Attainment Demonstration”), with several further details in Appendix A 

(“Weight of Evidence Analysis”) of the CARB Staff Report. For the modeling used in this Plan, the base

case year was 2000, the base year was 2012, and the future years were 2018 and 2020 for the 24-hour 

and annual PM2.5 standards, respectively. CARB scaled the results from modeling performed for the 

2008 PM2.5 Plan, assuming the same relative response to emission changes applies in the time frame for 

the current Plan. Starting from the RRFs from the 2008 PM2.5 Plan, which reflect the emission changes 

from the base year to the future year in that plan (2005 to 2014), CARB scaled those RRFs to reflect the 

current 2015 PM2.5 Plan’s base year to future year emission changes (2012 to 2020 for the annual 

standard, and 2012 to 2018 for the 24-hour standard). 

The formula in the 2015 PM2.5 Plan377 for scaling an RRF is based on the definition of an RRF as 

(modeled future concentration) / (modeled base year concentration), and on the assumption that the 

modeled percent change in concentration per percent change in emissions is the same for the 2015 PM2.5

 

376 Modeling Guidance Update at 43 ff. 

377 2015 PM2.5 Plan, Chapter 4, p. 4-8, and Appendix F, p. F-4. 
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Plan as it was for the 2008 PM2.5 Plan. As shown in section IV.A of the EPA’s General TSD for this 

action, these assumptions lead to the Plan formula. Since the RRF includes the modeled effect of 

emission changes, accounting for their temporal and spatial distribution and their chemistry, the scaling 

approach used in the 2015 PM2.5 Plan differs from a simple “rollback” scaling (which would merely 

assume that the percent concentration change is identical to the percent emissions change). 

CARB’s procedure for using emissions from the two plans in the RRF scaling formula differed 

to some extent between the two plans due to data availability, even though ideally they would be treated 

in the same way. The reason the scaling is being done rather than new modeling is that modeling 

inventories were not available for the base and future years of the 2015 PM2.5 Plan. Only the planning 

inventories are available; they cover all the source categories, but do not reflect the allocation of the 

emissions to all the grid squares in the modeling domain and to all the hours of the year, a considerable 

undertaking necessary for input to the model. Absent the future modeling inventories, the most 

consistent way to perform the scaling would be to use planning inventories from both the new and old 

plans. Because the scaling is done for each chemical species, the inventories used should also be 

speciated using the same procedure, by applying speciation profiles for the various emission source 

categories. Unfortunately, the old speciation profiles for the 2008 PM2.5 Plan were not available, so the 

planning inventory from the 2008 PM2.5 Plan could not be speciated in the same way as the 2015 PM2.5

Plan planning inventory could. Therefore, CARB used the modeling inventory from the 2008 PM2.5

Plan, which did have a speciation procedure comparable to that available for the 2015 PM2.5 Plan 

planning inventory. In sum, in calculating the RRF scaling factors, CARB used the modeling inventory 
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115 

to compute percent emission changes for the 2008 PM2.5 Plan and used the planning inventory for 

emission changes for the 2015 PM2.5 Plan.378, 379

CARB’s modeling domain is somewhat larger than the SJV nonattainment area, so emission 

totals differ between the modeling inventory and the planning inventory. But we expect that percent 

changes are comparable because both the modeling inventories and planning inventories reflect 

emissions from the same types of sources and in similar proportions. The inventories also reflect similar 

controls, for example statewide motor vehicle emissions controls, where motor vehicles are the main 

source of NOx. We also expect the ratios of the percent changes, i.e., the RRF scaling factors 

themselves, to be comparable given discrepancies between the modeling and planning inventories would 

typically be similar for the two plans used in the ratio, and hence canceled out to an extent. 

The 2015 PM2.5 Plan provided several bases to support the use of a scaling approach premised on 

the 2008 PM2.5 Plan model response. The base case in the previous modeling was based on extensive 

measurements during the 2000 CRPAQS study,380 and the underlying meteorological conditions leading 

to high PM2.5 concentrations in the 2000-2001 winter were similar to those in the 2013-2014 winter, 

including persistent pressure ridges, surface inversions, cool temperatures, and low winds.381 Also, the 

2004-2006 PM2.5 species composition data that CARB used for speciating PM2.5 concentrations in the 

2008 PM2.5 Plan show a similar composition to 2011-2013 speciation measurements that CARB used in 

 

378 2015 PM2.5 Plan, Appendix F, p. F-4. 

379 Modeling the ambient PM2.5 components of elemental carbon (EC) and organic carbon (OC) and geological material 

requires emissions for those, derived from speciation profiles of the various emission source categories. The RRF scaling also 

requires separate EC and OC emissions. But planning inventories, such as that available for the 2008 plan, generally report 

only direct PM2.5 emissions, the total of these species. 

380 2000 California Regional Particulate Air Quality Study (CRPAQS); descriptive documents available on CARB’s “Central 

California Air Quality Studies” web site at http://www.arb.ca.gov/airways. 

381 2015 PM2.5 Plan, Appendix F, p. F-4, and WOEA, p. A-5. 
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the 2015 PM2.5 Plan to speciate design values prior to applying RRFs, as seen in composition pie charts 

for Bakersfield, Fresno, Modesto, and Visalia.382

These observations indicate that the 2013 PM2.5 design values for the current 2015 PM2.5 Plan 

would respond in a way similar to the 2008 PM2.5 Plan modeling. An alternative would have been to use 

modeling from the 2012 PM2.5 Plan, which had a 2007 meteorology and emissions base case, which is 

more recent than that in the 2008 PM2.5 Plan. However, it modeled only the first and fourth quarters, the 

only quarters needed to address the 24-hour NAAQS; the 2008 PM2.5 Plan modeled the entire year, and 

so was suitable for assessing both the 24-hour and the annual PM2.5 NAAQS. 

CARB calculated an RRF from the scaling formula using the concentration of each PM2.5

chemical species, with emissions from the corresponding precursor. CARB used percent changes in 

emissions of NOx, SOx, Organic Carbon (OC), Elemental Carbon (EC), and other (direct PM2.5 less OC 

and EC), to scale the RRF for the corresponding ambient PM2.5 component: nitrate (NO3

-

), sulfate (SO4

-

2

), OC, EC, and geological material (also called “other” or “dust”). For the ammonium component, 

which is present in ammonium nitrate and ammonium sulfate, a choice must be made as to which 

precursor emissions, either NOx or SO2, should be used in scaling ammonia; CARB used NOx. 

This is in line with information in the Plan indicating that ammonium nitrate formation responds 

far more to NOx emission changes than to ammonia changes. The Plan also noted that sulfate is a much 

smaller ambient component than nitrate, so that ammonium scales more with NOx than with SO2.

383

Conceivably some combination of precursor emissions could have been used for scaling ammonium, but 

that would require a plausibility argument about how to reflect the actual chemistry involved, a 

 

382 2015 PM2.5 Plan, Appendix F, Attachment A, p. F-8 to F-10. 

383 2015 PM2.5 Plan, Appendix F, p. F-5. 
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complication that would obscure both the relative simplicity of direct scaling and the more 

comprehensive consideration of chemistry already present in the modeling being scaled. Another point 

about the choice of NOx is that ammonium concentrations were independent of ammonia emissions, 

since the latter was not used, and so inherently cannot respond to increases or decreases of ammonia that 

occur during the planning period. 

As discussed in section V.C of this notice, modeling for the 2012 PM2.5 Plan showed that there is 

a small ambient response to ammonia changes. Additionally, annual average ammonia emissions in the 

planning inventory increase by 8.6% from 2012 to 2020, which suggests that the ammonium 

contribution to projected design values may be higher than stated in the Plan. However, this is of little 

concern since the pre-scaled RRFs for ammonium, nitrate, and sulfate were based on actual modeling 

for the 2008 PM2.5 Plan; they take into account the atmospheric chemistry and the ambient effects due to 

ammonia changes during 2005-2014, when the annual average ammonia emissions increased by 18.1%. 

Aside from the RRFs themselves, the procedure that CARB followed in the 2015 PM2.5 Plan for 

projecting design values is consistent with the recommendations in the Modeling Guidance. The steps 

included using daily speciation data and the SANDWICH approach384 to split daily measured PM2.5

concentrations into their chemical components, taking quarterly averages (of all days for the annual 

standard, and of the highest 10% or so of days for the 24-hour standard), applying RRFs to get future 

component concentrations, summing to total PM2.5, and finally averaging over quarters and years to 

estimate the future design value. 

 

384 Sulfate, Adjusted Nitrate, Derived Water, Inferred Carbonaceous mass material balance approach: Modeling Guidance, p. 

47; Frank, N., 2006: “Retained Nitrate, Hydrated Sulfates, and Carbonaceous Mass in Federal Reference Method Fine 

Particulate Matter for Six Eastern U.S. Cities,” J. Air Waste Management Assoc., 56, 500-511. 
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Two aspects of the Plan’s approach to modeling differ from the Modeling Guidance 

recommendations. First, for the 24-hour PM2.5 NAAQS, the RRFs were applied to a single high value 

per quarter to represent the potential 98th percentile, as opposed to applying RRFs to multiple high 

individual days in each quarter, and then choosing the 98th percentile. The former approach is consistent 

with the original Modeling Guidance, before it was updated to the latter approach by the June 28, 2011

Modeling Guidance Update.385 The latter approach is intended to allow for the shifting of high days 

between quarters as emission controls are applied: a day that has a concentration in the top 10% in the 

autumn may more strongly respond to controls and no longer be in the top 10%, while a summer day 

may respond less to controls and end up being in the post-control top 10%. Because winter PM2.5

concentrations are significantly higher than those in the other seasons, such shifting is very unlikely to 

be an issue in the SJV. 

Second, the Modeling Guidance recommends that RRFs be applied to the average of three threeyear design values386 (e.g. using data in 2010-2012, 2011-2013, and 2012-2014), whereas the Plan used 

just the single 2013 design value (2011-2013 data). The 2011-2013 period for the 2013 design value is 

centered on the Plan’s 2012 base year, as the Modeling Guidance recommends. One reason for the 

longer period in EPA’s recommendation is that the additional averaging provides some stability in the 

estimate. 

Although the Plan’s procedure is not entirely consistent with EPA guidance, we find it 

acceptable in this context given the time constraints imposed by EPA’s April 2015 reclassification of the 

SJV area387 and the available modeling analyses. Despite the presence of scaling at a key step, CARB’s 

 

385 Modeling Guidance, p. 58 and Modeling Guidance Update, p. B-2 (Steps 1, 4, and 5). 

386 Modeling Guidance, p.22; and Modeling Guidance Update, p. B-1. 

387 80 FR 18528 at 18530 (April 7, 2015) (noting unusually short timeframe for State’s development and submission of a plan 

to provide for attainment of the 1997 PM2.5 NAAQS by the Serious area attainment date, which is December 31, 2015). 
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119 

approach remains a modeled attainment demonstration as required by section 189(b)(1)(A) of the Act. It

relies on photochemical modeling that EPA reviewed and approved388 for the 2008 PM2.5 Plan, and 

which remains sufficiently representative of PM2.5 formation in the SJV. 

Three other considerations give some reassurance of the acceptability of a scaling approach. 

First, EPA’s 2014 draft modeling guidance explicitly recognizes that “there may be plausible alternative 

means of calculating the relative response factors [RRFs] that can differ from the approaches 

recommended.”389 While this 2014 draft guidance does not specifically address the alternative of scaled 

RRFs, it indicates, as does the Modeling Guidance, that alternatives to the recommended procedures are

acceptable where adequately supported. Second, even the recommended RRF procedure involves model 

sensitivity derived from one period being applied to another: RRFs are computed using a single year’s 

modeled response to emissions changes, but are assumed to be applicable to all five years composing the 

average over three design values. This consideration makes the 2015 PM2.5 Plan’s application of the 

model response from one period to another analogous to the application more broadly envisioned by the 

Modeling Guidance. 

Finally, while scaling itself is relatively crude, the scaling of RRFs is less so. The procedure is 

not a simple scaling of an emission total, but reflects the geographic and temporal distribution of the 

emissions sources and the emission changes, since it is based on modeling. The pattern of emission 

changes during the span of the 2015 PM2.5 Plan does not exactly match the changes modeled for the 

span of the 2008 PM2.5 Plan, but many of the emission reductions continue the effect of existing controls 

 

388 “Technical Support Document for the Proposed Action on the San Joaquin Valley 2008 PM2.5 Plan and the San Joaquin 

Valley Portions of the Revised 2007 State Strategy,” EPA Region 9, November 8, 2010, for proposed approval in 75 FR 

74518 (November 30, 2010); final approval was in 76 FR 69896 (November 9, 2011). 

389 “Modeling Guidance for Demonstrating Attainment of Air Quality Goals for Ozone, PM2.5, and Regional Haze”, DRAFT 

December 2014, EPA OAQPS, p. 99. 
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on the same types of sources, so the patterns of the emissions changes are unlikely to be very different. 

For example, continued vehicle NOx emission reductions occur over much the same roadway network 

and direct PM2.5 reductions from controls on wood burning are largely achieved from the same 

residential areas. 

Late in EPA’s review process, EPA and CARB found that the scaling factor for EC had been 

applied to the RRF for OC and the product used as the RRF for EC, and vice versa.390 Because the 

original RRFs for OC were larger than those for EC, and remained so after scaling, applying the smaller 

EC scaled RRFs to OC made the projected OC concentration smaller than it should have been. 

Conversely, projected EC was larger than it should have been. Because OC has a larger ambient 

contribution than EC, the OC effect dominates. The net result of the EC-OC reversal is that the projected 

design values for the attainment demonstration were underestimated. CARB estimates that the 2020 

annual design value for Madera increased from the 2015 PM2.5 Plan’s original 15.0 μg/m3

 to a corrected 

value of 16.2 μg/m3,

391 which is above the 1997 annual PM2.5 NAAQS. 

However, CARB presents compelling reasons for discounting this high Madera projected 2020 

annual design value. The starting point for the scaled modeling projection is the 2013 design value – the 

average of annual means during 2011-2013. The 2011 monitoring data included within that 2013 design 

value appears anomalous, as documented in the WOEA at Appendix A2 (“Assessment of the 

Representativeness of 2011 PM2.5 Beta Attenuation Monitor Data from Madera”) and Attachment B to 

CARB’s Technical Clarifications of August 12, 2015 (“Attachment B”). We refer herein to figures and 

tables in Appendix A2 of the WOEA as “S.R. App. A2, Figure 2.” 

 

390 Letter from K. Magliano, CARB to K. Drake, EPA Region 9, August 12, 2015. See also, Memo to file, “Call with 

California Air Resources Board regarding letter about reversal of elemental and organic carbon,” S. Bohning, EPA Region 9, 

September 18, 2015. 

391 Id., Attachment A (“Revised San Joaquin Valley PM2.5 Design Values”). 
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EPA’s regulations require that monitoring data for comparison to the NAAQS be collected using 

specific equipment and procedures to ensure accuracy and reliability.392 For each NAAQS, the default 

monitoring equipment and the procedures for operating it are termed the Federal Reference Method 

(FRM); an alternative approach, termed a Federal Equivalent Method (FEM) may also be used if it is 

demonstrated to give results comparable to an FRM monitor. The Met One Beta Attenuation Monitor 

(BAM) 1020 is an example of an FEM that provides continuous hourly PM2.5 concentrations compared 

to the FRM’s 24-hour average PM2.5 concentrations. This is useful for a number of purposes, including 

real-time forecasting for deciding when to issue public advisories and wood burning restrictions, as well 

as for evaluating air quality model performance. BAMs are deployed at multiple sites in the SJV, 

including Madera (the “Madera-City” site, AQS ID 06-039-2010).393

 

As described in the S.R. App. A2, 2011 was the first full year of data collected by the Madera 

BAM, and the concentrations were unexpectedly high in comparison with other monitoring sites, 

including both BAMs and FRM monitor sites. During 2011-2013, annual concentrations at Madera were 

some 30% higher than at Fresno, and as much as 100% higher during the summer, historically the 

season with the lowest PM2.5.

394 This was unexpected because historically there has been a north-tosouth increasing gradient of concentrations, with northern sites like Stockton and Merced at the low end, 

and southern sites like those in Bakersfield at the high end, and with central sites like Fresno somewhere 

in between.395 This gradient is consistent with the greater potential for ventilation at the northern end of 

the SJV, nearest the opening to the ocean at the Golden Gate, and the lower ventilation at the southern 

 

392 40 CFR parts 53 and 58. 

393 2015 PM2.5 Plan, Chapter 4, Table 4-3 (“Projected 2020 Annual and 2018 24-hour Design Values”), p.4-9. 

394 S.R. App. A2, Figures 3 and 4, and Tables 1 and 2.

395 S.R. App. A2, Figure 2. 
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end, surrounded by mountains. Madera and Fresno concentrations are highly correlated,396 suggesting 

common meteorological influences at the two sites, as opposed to additional emission sources 

contributing at Madera. 

Various checks on the monitor and its operation were made over time without affecting the high 

readings, but in April 2014, adjustments were made as a result of checking the zero point of the 

instrument using outdoor air, rather than indoor air (both are permissible; outdoor air could be more 

representative of the conditions the instrument normally operates under).397 After that time, Madera 

concentrations shifted to lower values,398 conformed better to the known north-south gradient,

399 and 

tracked closely with the monitored data from the Merced-Coffee Road site about 30 miles to the North, 

which is expected given the two monitors’ proximity to one another and similar geographic 

conditions.400 They also agreed better with measurements at a new FRM installed in July 2014 at the 

Madera site.401 ARB concluded that the 2011 “BAM data at Madera appear to be biased high due to 

sampling artifacts... not representative of air quality in the central portion of the Valley”.402

The 2015 PM2.5 Plan nevertheless included the 2011 Madera data and 2013 design value in the 

attainment demonstration, because up until recently the issue appeared to be moot, as despite the high

starting point concentration the modeling predicted a 2020 annual concentration of 15.0 μg/m3, which 

attains the 1997 annual PM2.5 NAAQS. The discovery of the EC-OC reversal described above brings the 

issue to the fore because there is no room for the increase it causes in the 2020 Madera design value.

 

396 S.R. App. A2, Figure 3. 

397 “BAM 1020 Particulate Monitor Operation Manual, BAM-1020-9800 Rev K”, Met One Instruments, Inc. 2008;

Memorandum from Tim Hanley, Office of Air Quality Planning and Standards, EPA to Met One BAM Users, “RE: Zero 

Tests on the Met One BAM 1020,” October 5, 2012. 

398 S.R. App. A2, Figure 8. 

399 S.R. App. A2, Figure 9. 

400 Letter from K. Magliano, CARB to A. Steckel, EPA Region 9, August 12, 2015, Attachment B, p. 2. 

401 S.R. App. A2, Figures 12 and 13. 

402 S.R. App. A2, p.A2-9. 
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The fact that 2011-2013 Madera BAM concentrations are higher than values at the Fresno FRM 

and other sites does not in itself prove they are incorrect; it is conceivable that unknown sources were 

contributing there. Also, the later agreement between the lower Madera BAM and FRM concentrations 

could be explained as sources that are now emitting less, or that are contributing less at the monitor due 

to different wind patterns. Nevertheless, the mismatch with the historical gradient pattern, the 

unexpectedly but only temporarily high readings that declined after an adjustment in operation, and the 

current lower FRM readings do suggest that the 2011 Madera concentrations were anomalous. EPA 

believes that the 2011-2013 readings at the Madera site are not known to be representative of air quality 

for Madera and not sufficiently certain to drive the SJV control strategy, or to invalidate the conclusion 

of the attainment demonstration that the SJV will attain the 1997 annual NAAQS in 2020. 

CARB explored two alternative scenarios to estimate annual average, ambient PM2.5 values in 

2020 for the Madera site.403 Under the first scenario, CARB substituted the 2014 design value of 15.8 

μg/m3 at the Madera site for its 2013 design value and estimated that the 2020 Madera design value 

would be 14.1 μg/m3. For the second scenario, CARB substituted the annual 2011 data from the 

Merced-Coffee Road site, adjusted upward to reflect the typically slightly higher values at Madera, 

resulting in an estimated 2020 Madera design value of 14.9 μg/m3. Both scenarios are reasonable 

alternatives to estimating the 2020 Madera design value for the SJV attainment planning purposes for 

the 1997 annual PM2.5 NAAQS. Accordingly, the Bakersfield-Planz site, which would have a corrected 

2020 design value of 15.0 μg/m3, would become the design value monitor for the SJV, as would be 

expected under the historic observation of a north-to-south increasing gradient of concentrations.404

 

403 Letter from K. Magliano, CARB to A. Steckel, EPA Region 9, August 12, 2015, Attachment B, pp. 3-4. 

404 Note that if the unexpectedly high concentrations seen in 2011-2013 are due to real phenomena affecting air quality, then 

they would be expected to occur again at some point in the intervening years between now and the projected attainment year 
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EPA accepts the scaled modeling approach of the attainment demonstration in the 2015 PM2.5

Plan, which was the product of extended discussion between EPA, ARB, and SJVUAPCD. Based on our 

review of the modeling approach and results, we propose to conclude that the 2015 PM2.5 Plan 

adequately demonstrates that the SJV area will attain the 1997 annual PM2.5 NAAQS by December 31, 

2020 and attain the 1997 24-hour PM2.5 NAAQS by December 31, 2018. We recommend that CARB

reassess the status of the modeled attainment of the 1997 24-hour and annual PM2.5 NAAQS as part of 

the new modeling required for SIP revisions addressing the 2006 and 2012 PM2.5 NAAQS. 

Evaluation of Bakersfield-Planz Data Exclusion for May 5, 2013 

As described in the 2015 PM2.5 Plan, the State and District based the attainment demonstration 

on ambient measurements during 2011-2013.405 The 24-hour PM2.5 concentration of 167.3 μg/m3

measured at the Bakersfield-Planz monitoring site (AQS ID: 06-029-0016) on May 5, 2013 was not 

included in the attainment demonstration analyses due to its unrepresentativeness for purposes of 

attainment planning for the SJV as a whole. Therefore, the modeled projections for the 2020 annual 

PM2.5 design values and 2018 24-hour design values406 and the discussion of the modeling results in 

Appendix F, section F.4 of the Plan are based on data that exclude the May 5, 2013 24-hour data point 

from the Bakersfield-Planz monitoring site. 

The Plan provides an assessment of the representativeness of this data for purposes of inclusion 

in the attainment demonstration analyses407 and concludes that: 

 

of 2020. If they do occur again, then they would influence the monitored attainment status at that time, and hence any request 

for SJV to be designated attainment. 

405 2015 PM2.5 Plan, Appendix F, p F-4. 

406 2015 PM2.5 Plan, Appendix F, Table F-1. 

407 2015 PM2.5 Plan, Appendix F, Attachment B: Assessment of the Representativeness of the PM2.5 Value Recorded at the 

Bakersfield-Planz Monitoring Site on May 5, 2013. 
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“In summary, comparison of the 167.3 μg/m3 concentration measured on May 5, 2013, to values 

typical for this season as well as comparison to values measured throughout the Valley on the same day, 

combined with the record high fugitive dust and elemental species concentrations, indicate that the 

monitor was impacted by microscale sources that are not representative of the neighborhood spatial 

scale the monitor is intended to represent. Therefore, this value is not included in modeling analysis for 

the San Joaquin Valley 2015 PM2.5 Plan.” 

The assessment provided in the Plan408 based this conclusion on: (1) representativeness of 

Bakersfield-Planz PM2.5 data;409 (2) potential fugitive dust sources affecting the Bakersfield-Planz 

site;410 and (3) meteorology at the Bakersfield-Planz site.411

Information provided regarding the representativeness of Bakersfield-Planz data included 

analyses of San Joaquin Valley seasonal PM2.5 concentrations412 and elemental species composition.413

The assessment provided PM2.5 data on the highest concentrations throughout the Valley since 2000 and 

shows that the May 5, 2013 Bakersfield-Planz value was unusually high compared to historical trends 

since 2000. Further, this data point was also unusually high compared to other sites in the San Joaquin 

Valley on the same day.414 The species composition analyses show that the primary content of the 

particulate matter was fugitive dust and that the level of the dust was over four times higher than the 

next highest value observed in the entire California network based on 14 years of available data. In 

addition, total elemental species and other chemical species were found to be unusually high. 

 

408 2015 PM2.5 Plan, Appendix F, Attachment B. 

409 2015 PM2.5 Plan, Appendix F, Attachment B, Section B. 

410 2015 PM2.5 Plan, Appendix F, Attachment B, Section C. 

411 2015 PM2.5 Plan, Appendix F, Attachment B, Section D. 

412 2015 PM2.5 Plan, Appendix F, pp. F-11 to F-13. 

413 Id., pp. F-13 to F-14. 

414 Id., pp. F-12 to F-13. 
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The State and District’s assessment of potential fugitive dust sources affecting the BakersfieldPlanz site was based on an evaluation of aerial photos to identify sources and field investigation by 

District enforcement staff.415 The assessment found no documented dust violations at any nearby sources 

and identify the likely source of the dust was from the open areas immediately adjacent to the monitor, 

suggesting a localized microscale impact. 

The third part of the assessment evaluated meteorology at the Bakersfield-Planz Monitoring 

Site.416 Wind speeds on May 5, 2013 were compared to other days in May 2013 and also to other high 

wind days at the Bakersfield-Planz site. The wind speeds were in excess of 25 mph for over eight hours

on May 5, 2013. The meteorology indicates that Bakersfield-Planz experienced a high wind event on 

May 5, 2013 that was unusual in terms of wind speed and duration. 

Overall, EPA agrees with the evidence provided that the Bakersfield-Planz monitor was affected 

by an unusual high wind dust event on May 5, 2013 that resulted in anomalous PM2.5 concentrations on 

that day. EPA believes that it is appropriate to omit this data point from the attainment demonstration 

based on EPA’s 2013 guidance on exceptional events.417 Regarding the inclusion of event-affected data 

for attainment demonstrations, EPA’s 2013 guidance says: 

“An air agency incorporating the event-related concentration in a design value used for a 

prospective attainment demonstration might seem to need more emission reductions to attain the 

NAAQS by its attainment deadline than is actually the case. The EPA plans to more formally address 

this topic on a pollutant/NAAQS basis, the first of which will be ozone guidance in the preamble of a 

soon-to-be-proposed rulemaking on SIP requirements for areas designated nonattainment for the 2008 

 

415 Id., pp. F-14 to F-16. 

416 Id., pp. F-17 to F-18. 

417 Memorandum from Steven D. Page, Director Office of Air Quality Planning and Standards, to Regional Air Directors, IX, “Interim Guidance to Implement Requirements for the Treatment of Air Quality Monitoring Data Influenced by 

Exceptional Events,” May 10, 2013 (“2013 Exceptional Events Guidance”). 
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ozone NAAQS. Until the planned guidance for a pollutant and NAAQS of interest is issued, air agencies 

should consult with their EPA regional office if they face this situation.”418 

EPA reviewed PM2.5 data in AQS for the SJV since 2010 and identified four days flagged with 

high wind exceptional event requests for exclusion. These PM2.5 high wind dust events do not appear to 

be recurring events and their inclusion in the attainment demonstration therefore would not accurately

reflect the effect of controls during more typical conditions at the Bakersfield-Planz monitoring site.

419

Based on these reviews, EPA agrees with the State’s and District’s assertion that the May 5, 2013 

concentrations at Bakersfield-Planz were due to an unusual PM2.5 high wind dust event that would not 

be appropriate to include in the attainment demonstration. 

In addition to EPA’s 2013 guidance on exceptional events, EPA also considered the monitoring 

requirements for PM2.5. In particular, 40 CFR Part 58, Appendix D, section 4.71(b) specifies for PM2.5: 

“The required monitoring stations or sites must be sited to represent area-wide air quality. These 

sites can include sites collocated at PAMS. These monitoring stations will typically be at neighborhood 

or urban-scale; however, micro-or middle-scale PM2.5 monitoring sites that represent many such 

locations throughout a metropolitan area are considered to represent area-wide air quality.” 

Based on the information provided in the Plan, EPA agrees that the Bakersfield-Planz 

concentrations on May 5, 2013 appear to have been affected by a localized event; therefore, it was 

neither representative of neighborhood scale concentrations, nor occurring at many locations. EPA 

agrees with the State and District that the May 5, 2013 concentrations at Bakersfield-Planz were not 

representative of area-wide, typical PM2.5 concentrations in San Joaquin Valley. 

 

418 Id.

419EPA also reviewed PM10 data in AQS for the SJV since 2010 and identified eight days flagged with high wind exceptional 

event request for exclusion, which indicate that PM10 high wind dust events recur and should be subject to reasonable 

controls in accordance with the 2013 Exceptional Events Guidance. 
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Based on the technical analyses provided in the Plan and EPA guidance and requirements as 

cited in this section, EPA agrees with the State and District that the May 5, 2013 Bakersfield-Planz 24-

hour PM2.5 data point resulted from a localized, anomalous event that can be omitted from the 

attainment demonstration analyses. 

Evaluation of Control Strategy 

The attainment control strategy in the 2015 PM2.5 Plan consists of State and District baseline 

measures that continue to achieve emission reductions and four additional control measures that the 

District either recently revised or, in one case, has committed to revise in 2016. With respect to baseline 

measures for stationary and area sources, the District identified the source categories under its 

jurisdiction and their projected emission levels in Appendix B, section B.2.2 (“Emissions Inventory 

Documentation”) and described each of the District measures that apply to these source categories in 

section B.2.2.3 of the Plan (“Control Profiles”).420 All but one of the 55 District control measures listed 

in section B.2.2.3 of the Plan have been approved into the California SIP. 421

With respect to mobile sources, the State identified the source categories and described the 

EMFAC2014 emission factor model used to project their future emission levels in Appendix B, sections 

B.2.2.4 through B.2.2.7 of the Plan.422 As explained in section V.D of this proposed rule, in a separate 

rulemaking, EPA is proposing to approve CARB’s submitted waiver measures into the SIP and intends 

to finalize that rulemaking before taking final action on the 2015 PM2.5 Plan. 

 

420 2015 PM2.5 Plan, Appendix B, pp. B-23 to B-31. See also, within this section, Table B-8 (“District Rules Included in the 

SIP Inventory”). 

421 See EPA Region 9’s website for information on District control measures that have been approved into the California SIP, 

available at: 

http://yosemite.epa.gov/r9/r9sips.nsf/Agency?ReadForm&count=500&state=California&cat=San+Joaquin+Valley+Unified+

APCD-Agency-Wide+Provisions. Of the District measures identified in Appendix B of the Plan, only Rule 4691 (“Vegetable 

Oil Processing Operations”), which limits VOC emissions from vegetable oil processing operations, is not currently approved 

into the California SIP. EPA approved a previous version of this rule (Rule 461.2) into the SIP on January 18, 1994 (59 FR 

2535). 

422 2015 PM2.5 Plan, Appendix B, pp. B-31 to B-35. 
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Table 8 below summarizes the emission reductions needed in the SJV to attain the 1997 24-hour 

and annual PM2.5 NAAQS by the end of 2018 and 2020, respectively. 

Table 8. Summary of Direct PM2.5 and NOx Emission Reductions Needed for the 2015 PM2.5 Plan 

Attainment Demonstration 

24-hour Standard 

Attainment by 2018 (tpd 

annual average) 

Annual Standard 

Attainment by 2020 (tpd 

winter average) 

 PM2.5 NOx PM2.5 NOx

A 2012 emissions inventory a 61.0 318.5 66.0 332.2

B

Emissions inventory after baseline 

measures 57.7 213.9 62.8 206.9

C

Emissions inventory needed to 

attain 54.4 213.7 60.8 206.5

D

Total emission reductions needed 

by attainment year (A - C) 6.6 104.8 5.2 125.7

Source: 2015 PM2.5 Plan, CARB Staff Report, Tables 1 and 2, p. 9, except as otherwise noted. 

a

 2015 PM2.5 Plan, Appendix B, Tables B-1 and B-2. 

The Plan identifies four District measures that will achieve additional emission reductions 

beyond baseline measures and contribute to expeditious attainment of the 1997 PM2.5 NAAQS.423 First, 

Rule 4308 (“Boilers, Steam Generators, and Process Heaters 0.075 to <2 MMBtu/hr”), as amended 

November 14, 2013, limits NOx emissions from boilers, steam generators, and process heaters sized 

between 0.075 and 2 MMBtu/hr and is projected to achieve 0.0007 tpd of NOx emission reductions by 

2018 and 0.0011 tpd of NOx emission reductions by 2020.424 EPA approved this rule into the California 

SIP on February 12, 2015.425

Second, the District has committed to amend Rule 4692 (“Commercial Charbroiling”) in 2016 to 

add requirements for under-fired charbroilers, with an anticipated compliance date in 2017.426 Rule 

 

423 2015 PM2.5 Plan, CARB Staff Report, Tables 1 and 2, p. 9. 

424 2015 PM2.5 Plan, Chapter 7, p. 7-3 and CARB Staff Report at p. 9. 

425 80 FR 7803 (February 12, 2015). 

426 2015 PM2.5 Plan, Chapter 7, section 7.1.2, p. 7-6 and SJVUAPCD Governing Board Resolution 15-4-7A (April 16, 2015) 

at paragraph 7. 
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4692, as approved into the SIP on November 3, 2011, regulates emissions from chain-driven 

charbroilers but does not regulate under-fired charbroilers.427 The District projects that its anticipated 

revisions to Rule 4692 to regulate under-fired charbroilers will achieve an additional 0.4 tpd of direct 

PM2.5 emission reductions in 2018 and 2020.428 EPA recently proposed to approve this commitment into 

the California SIP.429

Emission reductions of 0.4 tpd of direct PM2.5 represent 6.1% of the total PM2.5 emission 

reductions needed to attain the 1997 24-hour standard by 2018 and 7.7% of the total PM2.5 emission 

reductions needed to attain the 1997 annual standard by 2020.430 These are limited portions of the total 

PM2.5 emission reductions needed for expeditious attainment of the 1997 PM2.5 standards in the SJV. 

Based on the District’s history of timely meeting similar rule commitments (see section V.E.3 of this 

preamble), we find that the District is capable of fulfilling this commitment. We also find that the 

commitment to adopt the amended rule by 2016 is for a reasonable and appropriate timeframe given the 

need for PM2.5 emission reductions to attain by 2018 and 2020. Accordingly, we propose to approve this 

rule commitment as part of the control strategy in the 2015 PM2.5 Plan. For a more detailed discussion of 

this commitment and the District’s evaluations to date, see the EPA’s SJV Rules TSD. 

Third, the District projects that Rule 4901 (“Wood Burning Fireplaces and Wood Burning 

Heaters”), as amended September 18, 2014, will achieve 2.9 tpd of direct PM2.5 emission reductions by 

2018 and 1.6 tpd of direct PM2.5 emission reductions by 2020. Specifically, the District’s 2014 rule 

amendment to lower the rule’s “no burn threshold” from 30 μg/m3

 to 20 μg/m3 (24-hour average 

ambient PM2.5 concentration) for non-EPA certified, non-District registered wood burning devices is 

 

427 76 FR 68103 (November 3, 2011). 

428 2015 PM2.5 Plan, Chapter 7 at p. 7-6. 

429 80 FR 1816 at 1833 and 1844 (January 13, 2015). 

430 2015 PM2.5 Plan, CARB Staff Report, Tables 1 and 2, p. 9, and Appendix B (“Emissions Inventory”), Tables B-1 and B2. 
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projected to achieve a winter 24-hour average of 2.2 tpd of direct PM2.5 emission reductions by 2018 and 

an annual average of 1.1 tpd of direct PM2.5 emission reductions by 2020.431 The 2015 PM2.5 Plan relies 

on Rule 4901 for an additional 0.7 tpd of direct PM2.5 emission reductions (winter 24-hour average) by 

2018 and an additional 0.5 tpd of direct PM2.5 emission reductions (annual average) by 2020 resulting 

from homeowners replacing high-emitting fireplaces and stoves with low-emitting, EPA-certified 

devices.432 The EPA recently proposed to approve Rule 4901 into the California SIP.433

Finally, the District projects that Rule 4905 (“Natural Gas-Fired, Fan-Type Residential Central 

Furnaces”), as amended January 22, 2015, will achieve 0.2 tpd of NOx emission reductions by 2018 and 

0.4 tpd of NOx emission reductions by 2020.434 This rule includes a mitigation fee option that allows 

manufacturers to sell non-compliant furnaces for 36-month transition periods ranging from 2015 to 

2021, depending on unit type.435 Based on information in the District’s staff report on Rule 4905, the 

District estimates emission reductions of 0.105 tpd of NOx per year from three of the four types of units, 

which have compliance dates ranging from April 1, 2015 through October 1, 2016.436

The EPA recently proposed to approve Rule 4905 into the California SIP.437 Because the sale of 

non-compliant units is allowed to varying degrees in 2018 by manufacturers paying mitigation fees, we 

 

431 The District calculated these estimates using its estimates of direct PM2.5 emission reductions for the 120-day wood 

burning season covered by the rule and ratios of 120/365 days and 120/180 days for the annual average and winter (24-hour) 

average emission reductions, respectively. See SJVUAPCD, “Final Staff Report for Amendments to the District’s Residential 

Wood Burning Program,” Appendix B, (“Emission Reduction Analysis Amendments to Residential Wood Burning 

Program”) at B-12, September 18, 2014. 

432 The 0.7 tpd and 0.5 tpd emission reduction estimates assume that 14% of devices subject to Rule 4901 will be replaced by 

2018 and that 20% of such devices will be replaced by 2020, respectively. For a more detailed discussion of these emission 

reduction estimates, see the EPA’s SJV Rules TSD. 

433 80 FR 58637 (September 30, 2015). 

434 2015 PM2.5 Plan, CARB Staff Report, Tables 1 and 2, p. 9. 

435 SJVUAPCD, “Final Staff Report Amendments to Rule 4905 (Natural Gas-Fired, Fan-Type Central Furnaces,” January 22, 

2015, p. 9. See also EPA’s proposed rule on Rule 4905. 80 FR 68484 (November 5, 2015). 

436 SJVUAPCD Rule 4905 as amended January 22, 2015, Table 1 (“NOx Emission Limits and Compliance Schedule”). See 

also, SJVUAPCD, “Final Staff Report Amendments to Rule 4905 (Natural Gas-Fired, Fan-Type Central Furnaces,” January 

22, 2015, Appendix B, pp. B-9. 

437 80 FR 68484 (November 5, 2015). 
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propose to credit Rule 4905 with 0.035 tpd of NOx emission reductions in 2018 rather than the 0.105 tpd 

of emission reductions identified in the District’s staff report for the rule. The amount we propose to not 

credit (i.e., 0.16 tpd of NOx) represents only 0.2% of the total winter average NOx reduction from 2012 

to 2018.438 Using the 24-hour PM2.5 sensitivity of 0.08 μg/m3 per ton of NOx emission reduction at the 

projected 2018 design value site of Bakersfield-California St., as modeled for the 2012 PM2.5 Plan,439

this would result in an ambient 24-hour PM2.5 concentration increase of about 0.013 μg/m3

.

440 This 

represents a minimal effect on ambient PM2.5 levels and, therefore, does not undermine the Plan’s 

demonstration of attainment of the 1997 24-hour PM2.5 standard by December 31, 2018. 

In sum, the attainment demonstration in the 2015 PM2.5 Plan relies on numerous State and 

District baseline regulations and four additional District measures that EPA has either approved or 

proposed to approve into the California SIP, all of which collectively are projected to achieve emission 

reductions sufficient for the SJV area to attain the 1997 24-hour PM2.5 standard by 2018 and the 1997 

annual PM2.5 standard by 2020. Table 9 provides a summary of the emission reductions from the four 

additional District measures that we propose to credit toward the Plan’s attainment control strategy. 

Table 9. Summary of EPA Proposed Emission Reduction Credits for Additional District Control 

Measures Needed for the 2015 PM2.5 Plan Attainment Demonstration 

District Control Measure 

Annual Standard 

Attainment by 2020 (tpd 

annual average) 

24-hour Standard 

Attainment by 2018 (tpd 

winter average) 

PM2.5 NOx PM2.5 NOx

Rule 4308 0.0 0.0011 0.0 0.0007

Rule 4692 0.4 0.0 0.4 0.0

Rule 4901 1.6 0.0 2.9 0.0

Rule 4905 0.0 0.4 0.0 0.035

 

438 Percent of total winter average NOx emission reductions = 0.16 tpd/104.8 tpd = 0.2%. 

439 2015 PM2.5 Plan, WOEA, Table B-2 (“Modeled PM2.5 air quality benefit per ton of valley-wide precursor emission 

reductions”), p. A-27. 

440 Increase in ambient 24-hour PM2.5 concentration = (0.08 μg/m3

/ton of NOx emission reduction) * (0.16 tpd) = 0.013 

μg/m3. 
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Source: 2015 PM2.5 Plan, CARB Staff Report, Tables 1 and 2, p. 9. 

Conclusion 

As discussed above, the 2015 PM2.5 Plan’s air quality modeling demonstrates that the SJV will 

attain the 1997 24-hour PM2.5 standard of 65 μg/m3 by December 31, 2018 and the 1997 annual PM2.5

standard of 15.0 μg/m3 by December 31, 2020. This demonstration is based on expeditious 

implementation of the State’s and District’s BACM and MSM control strategy for stationary, area, and 

mobile sources in the 2015 PM2.5 Plan, together with the District’s commitment to achieve additional 

PM2.5 emission reductions from under-fired charbroilers through amendments to Rule 4692. Based on 

these evaluations, we propose to determine that the 2015 PM2.5 Plan provides for attainment of the 1997 

24-hour and annual PM2.5 standards by the most expeditious alternatives dates practicable, consistent 

with the requirements of CAA sections 189(b)(1)(A).

F. Reasonable Further Progress and Quantitative Milestones 

1. Requirements for Reasonable Further Progress and Quantitative Milestones 

CAA section 172(c)(2) requires nonattainment area plans to provide for reasonable further 

progress (RFP). In addition, CAA section 189(c) requires PM2.5 nonattainment area SIPs to include 

quantitative milestones to be achieved every three years until the area is redesignated to attainment and 

which demonstrate reasonable further progress (RFP), as defined in CAA section 171(1). Section 171(1) 

defines RFP as “such annual incremental reductions in emissions of the relevant air pollutant as are 

required by [Part D] or may reasonably be required by the Administrator for the purpose of ensuring 

attainment of the applicable [NAAQS] by the applicable date.” Neither subpart 1 nor subpart 4 of part 

D, title I of the Act requires that a set percentage of emissions reductions be achieved in any given year 

for purposes of satisfying the RFP requirement. 
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RFP has historically been met by showing annual incremental emission reductions sufficient 

generally to maintain at least linear progress toward attainment by the applicable deadline.441 As 

discussed in EPA guidance in the Addendum, requiring linear progress in reductions of direct PM2.5 and 

any individual precursor in a PM2.5 plan may be appropriate in situations where: 

• the pollutant is emitted by a large number and range of sources, 

• the relationship between any individual source or source category and overall air quality is not 

well known, 

• a chemical transformation is involved (e.g., secondary particulate significantly contributes to 

PM2.5 levels over the standard), and/or 

• the emission reductions necessary to attain the PM2.5 standard are inventory-wide.442

The Addendum states that requiring linear progress may be less appropriate in other situations, 

such as: 

• where there are a limited number of sources of direct PM2.5 or a precursor, 

• where the relationships between individual sources and air quality are relatively well defined, 

and/or 

• where the emission control systems utilized (e.g., at major point sources) will result in swift and 

dramatic emission reductions. 

In nonattainment areas characterized by any of these latter conditions, RFP may be better 

represented as step-wise progress as controls are implemented and achieve significant reductions soon 

thereafter. For example, if an area’s nonattainment problem can be attributed to a few major sources, 

EPA guidance indicates that “RFP should be met by ‘adherence to an ambitious compliance schedule’ 

 

441 Addendum at 42015. 

442 Id.
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which is likely to periodically yield significant emission reductions of direct PM2.5 or a PM2.5

precursor.”443

Plans for PM2.5 nonattainment areas should include detailed schedules for compliance with 

emission regulations in the area and provide corresponding annual emission reductions to be realized 

from each milestone in the schedule.444 In reviewing an attainment plan under subpart 4, EPA evaluates 

whether the annual incremental emission reductions to be achieved are reasonable in light of the 

statutory objective of timely attainment. Although early implementation of the most cost-effective 

control measures is often appropriate, states should consider both cost-effectiveness and pollution 

reduction effectiveness when developing implementation schedules for their control measures and may 

implement measures that are more effective at reducing PM2.5 earlier to provide greater public health 

benefits.445

Section 189(c) requires that attainment plans include quantitative milestones in order to 

demonstrate RFP. The purpose of the quantitative milestones is to allow periodic evaluation of the 

area’s progress towards attainment of the NAAQS through the RFP requirements. Thus, the EPA 

determines an area’s compliance with RFP in conjunction with determining its compliance with the 

quantitative milestone requirement. Because RFP is an annual emission reduction requirement and the 

quantitative milestones are to be achieved every three years, when a state demonstrates compliance with 

the quantitative milestone requirement, it will demonstrate that RFP has been achieved during each of 

the relevant three years. Quantitative milestones should provide an objective means to evaluate progress 

toward attainment meaningfully, e.g., through imposition of emission controls in the attainment plan and 

 

443 Addendum at 42015. 

444 Addendum at 42016. 

445 Id.
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the requirement to quantify those required emission reductions. The CAA also requires milestone 

reports (due 90 days after each milestone), and these reports should include calculations and any 

assumptions made concerning how RFP has been met, e.g., through quantification of emission 

reductions to date.446

The CAA does not specify the starting point for counting the three-year periods for quantitative 

milestones under CAA section 189(c). In the General Preamble and Addendum, EPA interpreted the 

CAA to require that the starting point for the first three-year period be the due date for the Moderate 

area plan submission.447 In keeping with this historical approach, EPA is proposing to establish 

December 31, 2014 as the starting point for the first 3-year period under CAA section 189(c) for the 

1997 PM2.5 standards in the SJV. This date was the due date established in the EPA’s June 2, 2014 

Deadline and Classification Rule for the State’s submission of any additional attainment-related SIP 

elements necessary to satisfy the subpart 4 Moderate area requirements for the 1997 PM2.5 standards in 

the SJV area.448 December 31, 2017 and December 31, 2020 would then be the milestone dates that the 

Serious Area plan must address, at minimum. The EPA believes that establishing December 31, 2017 as 

the first quantitative milestone date is an appropriate means for implementing the requirements of 

subpart 4 prospectively. 

2. RFP Demonstration and Quantitative Milestones in the 2015 PM2.5 Plan 

 

446 Id. at 42016, 42017. 

447 General Preamble at 13539, Addendum at 42016. 

448 79 FR 31566 (June 2, 2014) (final rule establishing subpart 4 moderate area classifications and deadline for related SIP 

submissions) (“Classification and Deadline Rule”). Although the Classification and Deadline Rule did not affect any action 

that EPA had previously taken under CAA section 110(k) on a SIP for a PM2.5 nonattainment area, EPA noted that states may 

need to submit additional SIP elements to fully comply with the applicable requirements of subpart 4, even for areas with 

previously approved PM2.5 attainment plans, and that the deadline for any such additional plan submissions was December 

31, 2014. Id. at 31569. 
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The RFP demonstration and quantitative milestones appear in Chapter 6, section 6.3 (pp. 6-6 to 

6-8) of the 2015 PM2.5 Plan. Further discussion of the RFP demonstration, particularly with respect to 

ammonia, and the establishment of dates, content, and a reporting commitment for quantitative 

milestones, appears in CARB’s Staff Report (pp. 25-26). In addition, by letter dated December 15, 2015, 

CARB’s Executive Officer committed to submit a SIP revision to supplement the quantitative milestone 

portion of the 2015 PM2.5 Plan by December 31, 2016 (“QM Letter”).449

The Plan estimates that emissions of direct PM2.5, NOx, and SOx will decline from the 2012 base 

year to 2020 and states that emissions of each of these pollutants will remain below the levels needed to 

show “generally linear progress” from 2012 to 2020, the year that the Plan projects to be the earliest

practicable attainment date for the 1997 annual PM2.5 standard.450 The Plan’s emissions inventory shows 

that direct PM2.5, NOx, and SOx are emitted by a large number and range of sources in the SJV and the 

emission reductions needed for these pollutants are inventory wide.451 The District followed the 

procedures in the 2007 PM2.5 Implementation Rule to calculate 2014 and 2017 RFP targets (or 

“benchmark” emission levels) for direct PM2.5, NOx, and SOx and then concluded that projected 

emission levels for each pollutant, based on its adopted control strategy, would be below those targets in 

both milestone years.452 

The BACM control strategy that provides the basis for these emissions projections is described 

in Chapters 5 and 7 and Appendices C and D of the Plan. For stationary and area sources, the Plan 

highlights several rules that are projected to contribute to attainment of the PM2.5 standards.453 For 

 

449 Letter from R. Corey, Executive Officer, CARB to J. Blumenfeld, Regional Administrator, U.S. EPA Region 9, December 

15, 2015. 

450 2015 PM2.5 Plan, Chapter 6, Table 6-8 (“RFP Target Demonstration (2014 and 2017)”), p. 6-8. 

451 2015 PM2.5 Plan, Appendix B. 

452 2015 PM2.5 Plan, pp. 6-6 to 6-8. 

453 2015 PM2.5 Plan, Chapter 7, Section 7.1.1, pp. 7-2 to 7-6. 
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example, Rule 4354 (“Glass Melting Furnaces”) controls emissions of NOx, SOx, and PM from 

industrial glass manufacturing – the largest source of SOx emissions in the San Joaquin Valley – and its 

emissions projections are presented in Appendix C as part of the Plan’s BACM and MSM analysis.454

Similarly, Rule 4901 (“Wood Burning Fireplaces and Wood Burning Heaters”) controls emissions from 

residential wood burning and addresses the largest combustion source of direct PM2.5.

455 Measures to 

control dust sources of direct PM2.5 are also presented in the Plan’s BACM and MSM analyses and 

reflected in the Plan’s baseline emission projections. Examples of such measures include Rule 4550 

(“Conservation Management Practices”)456 and Rule 8061 (“Paved and Unpaved Roads”).457 For mobile 

sources, the Plan lists numerous CARB regulations and discusses the key regulations that limit the 

emission of direct PM2.5 and NOx from on-road and non-road mobile sources.458 For instance, the 

regulations that apply to the two largest sources of NOx in the San Joaquin Valley – heavy, heavy-duty 

diesel trucks and farm equipment – are discussed in Appendix C and their emission projections are 

presented in the Plan’s emissions inventory.459

With respect to ammonia, the 2015 PM2.5 Plan projects an increase in annual average ammonia 

emissions from 329.5 tpd in 2012 to 358.0 tpd in 2020.460 The Plan states that both NOx and ammonia 

participate in forming ammonium nitrate (i.e., secondary PM2.5) but that NOx emission reductions are an 

order of magnitude more effective at reducing ambient PM2.5 than ammonia reductions.461 Based on the 

 

454 2015 PM2.5 Plan, Chapter 7, pp. 7-3 to 7-4 and Appendix C, p. C-102. 

455 2015 PM2.5 Plan, Chapter 7, p. 7-4 and Appendix C, p. C-157. 

456 2015 PM2.5 Plan, Appendix C, p. C-108. 

457 2015 PM2.5 Plan, Appendix C, p. C-194. 

458 2015 PM2.5 Plan, Chapter 7, Section 7.1.3, pp. 7-6 to 7-13. 

459 2015 PM2.5 Plan, Appendix D, pp. D-8 to D-12 (for heavy heavy duty trucks) and D-15 (for farm equipment) and 

Appendix B, p. B-7. 

460 2015 PM2.5 Plan, Appendix B, p. B-19. 

461 Id. See also, 2015 PM2.5 Plan, Chapter 2, p. 2-27, which concludes the District’s analysis of the relationship between 

ammonia emissions and ambient PM2.5 levels by stating that “ammonia reductions at the Bakersfield-California site are 

only... 10% as effective as NOx reductions.” 
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relative insensitivity of ambient PM2.5 levels to ammonia reductions compared to NOx reductions, the 

Plan states that ammonia is not a significant precursor to ambient PM2.5 in the SJV462 and thus that an 

RFP demonstration for ammonia is not required.463 The Plan also states that NOx emission levels are 

projected to be well below the levels needed to show generally linear progress toward attainment. The 

CARB Staff Report provides additional analysis by converting the increase in ammonia emissions into 

“NOx equivalent” emission levels (using a “NOx equivalency” calculation method) and demonstrating

that the “NOx equivalent” emissions level continues to show linear progress toward attainment from 

2012 to 2020.464

The NOx equivalency method used in the Plan relies on the sensitivity of ambient PM2.5 levels to 

decreases in ammonia emissions compared to decreases in NOx emissions, as modeled at the 

Bakersfield-California monitoring site. The Plan states that in the San Joaquin Valley ammonia emission 

reductions are only 10% as effective as NOx emission reductions, with a relative sensitivity factor of 

0.1.465 Stated alternatively, this is a 1:10 NOx for ammonia trading ratio, i.e., it takes 1 tpd of NOx

emissions to match the ambient effect of 10 tpd of ammonia in this area. The State calculates the change 

in ammonia emissions from the base year (2012) to each RFP milestone year466 (2014 and 2017), and 

multiplies it by the trading ratio to calculate a NOx increase equivalent to the ammonia increase, which

the State then adds to the NOx emissions inventory for each RFP milestone year to calculate the total 

 

462 2015 PM2.5 Plan, Chapter 2, section 2.6 (“Insignificant Precursors to PM2.5 Concentrations in the Valley”). 

463 2015 PM2.5 Plan, CARB Staff Report, p. 26. 

464 2015 PM2.5 Plan, CARB Staff Report, pp. 25-26. 

465 2015 PM2.5 Plan, Chapter 2, p. 2-27. Note that Bakersfield-California is projected to be the design value monitor for the 

SJV in 2018 with respect to the 1997 24-hour PM2.5 standard. 2015 PM2.5 Plan, Appendix F, Table F-1 (“Projected 2018 and 

2020 Design Values”), p. F-7. 

466 We use “RFP milestone year” to mean each year for which the Plan provides an RFP analysis and related emissions 

projections. 
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NOx decrease and ammonia increase expressed as “NOx equivalent” emission levels.467 The CARB Staff 

Report states that the total NOx equivalent emissions levels are below the linear reductions in NOx

necessary to demonstrate RFP and, therefore, that the RFP requirement is met, despite the projected 

increase in the ammonia inventory. 

Control measures for ammonia sources are described in Appendix C of the Plan. For example, 

ammonia controls resulting from Rule 4570 (“Confined Animal Facilities”), Rule 4565 (“Biosolids, 

Animal Manure, and Poultry Litter Operations”), and Rule 4566 (“Organic Material Composting”) are 

discussed at length in section C.41 of Appendix C and their emission projections are presented 

collectively under farming operations in the Plan’s emissions inventory.468

 We discuss these control 

measures more fully in section V.D of this preamble (“Best Available Control Measures and Most 

Stringent Measures”) and in the EPA’s SJV Rules TSD. 

With respect to quantitative milestones, the CARB Staff Report states that the Plan identifies 

RFP emissions levels for direct PM2.5, NOx, and SOx for 2014 and 2017 that show generally linear 

progress towards attaining the annual standard in 2020, and that “[t]hese emission levels for 2017 along 

with the 2020 attainment emission levels serve as the quantitative milestones required under the Act.”469

CARB addresses the projected increase in ammonia emissions over the planning period by evaluating 

those emissions in light of the atmospheric response to NOx and ammonia emissions in the San Joaquin 

Valley area and concluding that “the combined emission levels of NOx and ammonia that are projected 

to occur through the 2020 attainment year provide for the required generally linear air quality 

 

467That is, (NOx emissions) 2017 + [(NH3 emissions) 2017 – (NH3 emissions) 2012] * 0.1 = (total NOx equivalent emissions) 2017. 

Using values from the 2015 PM2.5 Plan, the 17.5 tpd increase in ammonia emissions from 2012 to 2017 is equivalent to a 1.8 

tpd increase in NOx emissions, as follows: 235.7 + [347.0 – 329.5]*0.1 = 237.5 tpd. See CARB Staff Report, p. 26, Table 12. 

468 2015 PM2.5 Plan, Appendix C, Section C.41, pp. C-240 to C-281 and Appendix B, p. B-17. 

469 2015 PM2.5 Plan, CARB Staff Report, p. 26. 
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progress.”470 The CARB Staff Report also states California’s commitment to provide letters to EPA 

“reporting that the emission inventory milestones have been met and the status of any emission 

reduction commitments,” and to provide these letters by March 31, 2018 for the 2017 milestone and by 

March 31, 2021 for the 2020 milestone.471

Additionally, the QM Letter contains the State’s commitment to submit, by December 31, 2016, 

a SIP revision that supplements the quantitative milestone portion of the 2015 PM2.5 Plan by identifying 

specific quantitative milestones to be achieved by the 2017 RFP milestone year and 2020 attainment 

year that demonstrate reasonable further progress toward timely attainment of the PM2.5 NAAQS. The 

QM Letter states that this SIP revision will include the following milestones to track implementation of 

control measures and emissions levels at each milestone year: (1) a list of measures in the Plan’s 

BACM/BACT and MSM control strategy and key implementation requirements through 2017 and 2020, 

including compliance milestones for the State’s Truck and Bus Rule and the District’s residential wood

burning rule (Rule 4901), (2) compliance with the State’s and District’s enforceable commitments in the

Plan by the 2017 milestone date, and (3) updated emissions inventories for both 2017 and 2020.472 The 

QM Letter also states that the SIP revision will identify appropriate air quality quantitative milestones 

for 2017 and 2020 designed to evaluate air quality progress resulting from implementation of the Plan’s 

control strategy, including an assessment of monitored ambient PM2.5 concentrations and other variables 

affecting ambient PM2.5 concentrations in each of those years.473

3. Evaluation and Proposed Actions 

Reasonable Further Progress Demonstration 

 

470 Id. 

472 QM Letter, pp. 1-2. 

473 Id., p. 2. 
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With respect to direct PM2.5, NOx, and SO2, we agree that “generally linear progress” is an 

appropriate measure of RFP for the 1997 PM2.5 NAAQS in the SJV area given that, as the Plan 

documents, direct PM2.5, NOx, and SOx are emitted by a large number and range of sources in the SJV, 

the emission reductions needed for these pollutants are inventory wide,474 and secondary particulates 

contribute significantly to ambient PM2.5 levels in the SJV area.475

The 2015 PM2.5 Plan documents the State’s conclusion that all BACM, BACT, and MSM for 

these pollutants are being implemented as expeditiously as practicable and identifies projected levels of 

direct PM2.5, NOx, and SOx emissions in 2014 and 2017 that reflect full implementation of the State’s 

and District’s BACM/BACT and MSM control strategy for these pollutants.476 For example, Rule 4550 

(“Conservation Management Practices”) was adopted in 2004 and its requirements to control PM10

emissions (including PM2.5) from on-field crop and animal feeding operations are fully implemented.477

These operations represent the largest dust sources of direct PM2.5 in the San Joaquin Valley.478 More 

recently, SJVUAPCD revised Rule 4901 (“Wood Burning Fireplaces and Wood Burning Heaters”) in 

September 2014 by strengthening the District’s curtailment program for residential wood burning, 

thereby further limiting emissions from San Joaquin Valley’s largest combustion source of direct 

PM2.5.

479 These rule amendments provide part of the incremental emission reductions of direct PM2.5

from the 2014 to 2017 RFP milestone years and through the 2018 and 2020 attainment years.480

 

474 2015 PM2.5 Plan, Appendix B. 

475 2015 PM2.5 Plan, Chapter 5, Section 5.4.1 (“Significance Determination Approach”). 

476 2015 PM2.5 Plan, Chapter 6, Section 6.3, and Appendix B. See also our discussion of BACM/BACT in section V.D of this 

proposed rule. 

477 2015 PM2.5 Plan, Appendix C, pp. C-106 to C-107. 

478 2015 PM2.5 Plan, Chapter 5, Table 5-2, pp. 5-7 to 5-8. See also 2015 PM2.5 Plan, Appendix B, p. B-2, 

479 2015 PM2.5 Plan, Chapter 7, p. 7-4 and Appendix C, p. C-156. See also 2015 PM2.5 Plan, Appendix B, p. B-2. 

480 2015 PM2.5 Plan, CARB Staff Report, p. 9. 
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The Truck and Bus Regulation and Drayage Truck Regulation became effective in 2011 and 

have rolling compliance deadlines based on truck engine model year. These and other regulations 

applicable to heavy duty diesel trucks will continue to reduce emissions of diesel particulate matter and 

NOx through the RFP and attainment planning years.481 For instance, model year 1994 and 1995 heavy 

heavy duty diesel truck engines must be upgraded to meet the 2010 model year truck engine emission 

standards by 2016, and model year 1996-1999 engines must by upgraded by January 1, 2020.482 The 

emission reductions from these rules represent the largest portion of the NOx emission reductions upon 

which the Plan’s attainment and RFP demonstrations rely.483 With respect to SOx emissions, Rule 4354 

(“Glass Melting Furnaces”) was amended in May 2011, establishing SOx emission limits with 

compliance deadlines through January 1, 2014.484 This rule will achieve emission reductions through the 

2017 RFP milestone year and 2018 and 2020 attainment years. As explained in section V.D of this 

preamble, we are proposing to find that the State and District are implementing these BACM, BACT 

and MSM provisions for the 1997 PM2.5 NAAQS as expeditiously as practicable. 

Additionally, the method used to calculate RFP target (or “benchmark”) emission levels for 

direct PM2.5, NOx, and SO2 is generally consistent with the method provided in the 2007 PM2.5

Implementation Rule (40 CFR 51.1009(f)). We note that the 2015 PM2.5 Plan calculates the 2014 and 

2017 RFP benchmark emission levels using 2020 attainment emissions levels that are not consistent 

with the attainment targets presented in CARB’s Staff Report.485 We have, however, re-calculated the 

 

481 2015 PM2.5 Plan, Chapter 7, p. 7-9 to 7-10 and Appendix D, pp. D-8 to D-11. 

482 Title 13, California Code of Regulations, Section 2025 (‘‘Regulation to Reduce Emissions of Diesel Particulate Matter, 

Oxides of Nitrogen and Other Criteria Pollutants, from In-Use Heavy-Duty Diesel-Fueled Vehicles’’), paragraphs (e), (f), 

and (g), effective December 14, 2011. See also EPA’s final rule approving CARB’s Truck and Bus Rule. 77 FR 20308 at 

20309-20310 (April 4, 2012). 

483 2015 PM2.5 Plan, Appendix B, p. B-7. 

484 2015 PM2.5 Plan, Chapter 7, pp, 7-3 to 7-4. 

485 2015 PM2.5 Plan, Chapter 6, Table 6-6, p. 6-7 vs. CARB Staff Report, p. 9. 
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RFP benchmark emissions levels for these years using the attainment targets found in the CARB Staff 

Report,486 as shown in Table 10 below. The EPA’s calculations indicate that the Plan’s projected 2014 

and 2017 emission levels for direct PM2.5, NOx, and SOx are below the RFP benchmark emission levels 

for these years.487

Table 10. EPA Calculation of 2015 PM2.5 Plan RFP Demonstration (tpd, based on annual 

averages) 

2012 

Emissions 

Inventory a

2020 

Attainment 

Target b

Annual 

Incremental 

Reduction c

2014 RFP 

Benchmark 

2014 

Projected 

Emissions d

2017 RFP 

Benchmark 

2017 

Projected 

Emissions d

Direct 

PM2.5

66.0 60.8 0.65 64.7 63.3 62.75 62.5 

NOx 332.2 206.5 15.71 300.78 284.2 253.63 235.7 

SOx 8.1 7.8 0.04 8.03 7.4 7.91 7.6 

a

 2015 PM2.5 Plan, Chapter 6, Table 6-6, p. 6-7. 

b

 2015 PM2.5 Plan, CARB Staff Report, Table 1, p. 9. 

c

 Annual incremental reduction = (2012 emissions inventory – 2020 attainment target) / (2020 – 2012). 

d

 2015 PM2.5 Plan, Chapter 6, Table 6-8, p. 6-8. 

With respect to ammonia, the 2015 PM2.5 Plan shows an 8.6% increase in total ammonia 

emissions during the 2012 to 2020 period.488 Unlike the wide range of sources emitting direct PM2.5, 

NOx, and SO2 in the Valley, emissions of ammonia are almost entirely from three source categories: 

confined animal facilities (CAFs), fertilizer application, and composting, with more than half of all 

emissions coming from CAFs.489 Collectively, these three categories emit 95% of all ammonia 

emissions in the 2012 annual average base year inventory.490

 

486 2015 PM2.5 Plan, CARB Staff Report, Table 1, p. 9. 

487 For example, the 2017 RFP benchmark for direct PM2.5 should account for five years’ worth of annual incremental 

reductions and is calculated as (2012 emission inventory) – (annual increment reduction)*5 = 66.0 tpd – (0.65 tpd/yr)*5 = 

62.75 tpd. The projected emissions inventory for direct PM2.5 in 2017 is 62.5 tpd, which is less than this RFP benchmark. 

488 2015 PM2.5 Plan, Appendix B, Table B-5. 

489 In the inventories provided in Appendix B of the Plan, emissions from these sources are found in the categories “Farming 

Operations”, “Pesticides/Fertilizers”, and “Other (Waste Disposal)”, respectively. 

490 2015 PM2.5 Plan, Appendix B, Table B-5 (“Ammonia”), pp. B-16 to B-19. The three categories comprising this 95% of 

emissions in the ammonia emission inventory are Other (Waste Disposal), Pesticides/Fertilizers, and Farming Operations. 
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Several District measures already in the SIP for the SJV area control ammonia emissions from 

two of these source categories. District Rule 4570 (“Confined Animal Facilities”) required 

implementation of control measures to reduce VOCs in 2008 and required full compliance by affected 

sources by mid-2012.491 Many of the VOC control measures have an ammonia co-benefit, and the 

District estimates a 100 tpd reduction in ammonia from this rule, which have been accounted for in the

emissions inventory of the 2015 PM2.5 Plan.492 The Plan also indicates that implementation of District 

Rule 4565 (“Biosolids, Animal Manure, and Poultry Litter Operations”), adopted March 15, 2007,493

and Rule 4566 (“Organic Material Composting Operations”), adopted August 18, 2011,494 resulted in 

some ammonia reductions, but these reductions are not reflected in the base year or baseline inventories. 

As discussed in section V.D of this proposed rule, we are proposing to determine that each of these 

measures implements BACM and MSM for the control of ammonia as a precursor to PM2.5 in the San 

Joaquin Valley for purposes of the 1997 PM2.5 NAAQS. 

 The statement in the Plan that ammonia is an insignificant precursor in the SJV area is based on 

the State’s analysis of the relative sensitivity of ambient PM2.5 levels to changes in ammonia emissions 

as compared to NOx emissions. The State relies in part on information previously presented in the 2012 

PM2.5 Plan for the 2006 24-hour PM2.5 standard to justify a NOx for ammonia trading ratio of 0.1. The 

2012 PM2.5 Plan contains modeling results and states that “reductions in ammonia are approximately 

nine times less effective than NOx.”495 The 2012 PM2.5 Plan also gives ammonia and NOx sensitivities 

(ambient PM2.5 changes in μg/m3 per tpd of emission reductions), based on modeling of the ambient 

 

491 2015 PM2.5 Plan, Appendix C, pp. C-240 to C-243. 

492 2015 PM2.5 Plan, Appendix C, pp. C-240 to C-241. See also, Memo to file, “Call with California Air Resources Board 

regarding VOC and ammonia emissions inventory,” R. Mays, EPA Region 9, September 30, 2015. 

493 2015 PM2.5 Plan, Appendix C, pp. C-276. 

494 2015 PM2.5 Plan, Appendix C, pp. C-272 to C-273. 

495 2012 PM2.5 Plan, Appendix G (“Weight of Evidence Analysis”), p. 64. 
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effect of a 25% area-wide reduction in each pollutant.496 The ratios of these sensitivities give an 

ammonia-NOx relative sensitivity ratio, or NOx for ammonia trading ratio, of 0.10 for the BakersfieldCalifornia site, and 0.11 (about 1/9) for the Bakersfield-Planz site.497

 

The 2015 PM2.5 Plan similarly reflects the State’s conclusion that ammonia emission reductions 

are about 10% as effective as NOx reductions in decreasing ambient PM2.5 concentrations.498 We have 

reviewed the modeling analysis from which the State and District derived the 0.1 NOx for ammonia 

trading ratio and propose to find that this ratio is a reasonable estimate of the sensitivity of ambient 

PM2.5 to ammonia reductions relative to NOx reductions, at least for the Bakersfield-California and 

Bakersfield-Planz monitoring sites for which the analysis was performed. For further discussion of our

evaluation of this trading ratio for purposes of the Plan’s RFP demonstration, see section IV.A of the 

EPA’s Interpollutant Trading Ratios TSD. 

The Bakersfield-California site is projected to be the design value site for the 1997 24-hour 

PM2.5 standard in 2018,499 which addresses the requirement of 40 CFR 51.1009(h) that an equivalent 

method for demonstrating RFP must do so at the design value monitoring site within the nonattainment 

area. As discussed in section V.E.5 of this proposed rule, although the State had initially projected the 

Madera site to be the design value site for the 1997 annual PM2.5 standard in 2020, based on weight of 

evidence, it now appears the Bakersfield-Planz site will most likely be the design value site for the 

annual PM2.5 standard in 2020. Either way, the 0.1 ammonia-NOx relative sensitivity factor is adequate 

 

496 2012 PM2.5 Plan, Appendix G, Table 7, p. 65. 

497 The difference between these two figures is about 0.1% when carried through in the calculation of the NOx equivalent of 

ammonia. 

498 2015 PM2.5 Plan, Chapter 2, pp. 2-27 (stating that “ammonia reductions at the Bakersfield-California site are ... only 10% 

as effective as NOx reductions”); see also CARB Staff Report, p. 26 and Table 12 (expressing NOx and ammonia emissions 

combined as “NOx equivalent” emission levels). 

499 2015 PM2.5 Plan, Appendix F, Table F-1 (“Projected 2018 and 2020 Design Values”), p. F-7. 
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for the RFP demonstration because it is derived from modeling analyses that account for emission 

projections at both of these Bakersfield monitoring sites. 

Taking the ammonia emissions increases into account, the NOx equivalent emission levels 

presented in the Plan500 for the 2014 and 2017 RFP milestone years fall below the benchmark RFP NOx

emissions levels for those same years.501 In essence, the substantial reduction of NOx emissions that is 

projected to result from the Plan’s control strategy (i.e., 37.8% reduction) from 2012 to 2020502 appears 

to more than offset the increase in ammonia emissions (i.e., 8.6% increase) that is projected to occur 

during that same period.503 More specifically, as shown in Table 11, taking into account the increase in 

ammonia emissions during the 2012 to 2020 period, the NOx equivalent emission levels projected in the 

Plan for the 2014 and 2017 RFP milestone years are 5-6% lower than the levels representing generally 

linear NOx emission reductions for those same years, thus showing NOx emission reductions at a rate 

faster than the benchmark scenario. 

Table 11. Comparison of NOx Equivalent Emissions to RFP Linear Emissions Level for NOx for 

RFP Milestone Years 

 (tpd, except row G) 2012 2014 2017 

A NOx Emissions 332.2 284.2 235.7

B Ammonia Emissions 329.5 336.2 347.0

C NOx equivalent of ammonia increase 0.7 1.8

D Total NOx Equivalent Emissions (A+C) 284.9 237.5

E RFP Linear Level for NOx 300.9 253.9

 

500 2015 PM2.5 Plan, CARB Staff Report, p. 26. 

501 This approach is consistent with the regulatory option of 40 CFR 51.1009(g)(2) that the RFP plan demonstrate emission 

levels that are “projected to result in a generally equivalent improvement in air quality by the milestone year as would be 

achieved under the benchmark RFP plan.” 

502 2015 PM2.5 Plan, Appendix B, Table B-2, p. B-8 and CARB Staff Report, p. 9. Emissions of NOx are project to decrease 

from 332.2 tpd in 2012 to 206.5 tpd in 2020 (i.e., a decrease of 125.7 tpd or 37.8%). 

503 2015 PM2.5 Plan, Appendix B, Table B-5, p. B-19. Emissions of ammonia are project to increase 329.5 tpd in 2012 to 

358.0 tpd in 2020 (i.e., an increase of 28.5 tpd or 8.6%). 
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F Total NOx Equivalent Emission Reductions 

Beyond RFP Linear Level (E-D) 

16.0 16.4

G % Below RFP Linear Level (F/E) 5.3% 6.5%

Source: 2015 PM2.5 Plan, CARB Staff Report, Table 12, p. 26. 

As discussed in section V.C of this proposed rule, we are proposing to determine that VOCs do 

not contribute significantly to ambient PM2.5 levels that exceed the 1997 PM2.5 standards in the SJV and, 

accordingly, that no RFP demonstration for VOCs is necessary for purposes of the 1997 PM2.5 standards 

in this area. 

In sum, the 2015 PM2.5 Plan demonstrates that emissions of direct PM2.5, NOx and SOx will be 

reduced at rates representing generally linear progress toward attainment, and that the increase in 

ammonia emissions over the 2012-2020 planning period will be more than offset by substantial NOx

emission reductions exceeding the amounts necessary to show generally linear progress toward 

attainment. The Plan also demonstrates that all BACM, BACT and MSM that provide the bases for the 

direct PM2.5, NOx, SOx, and ammonia emissions projections in the RFP analysis in the Plan are being 

implemented as expeditiously as practicable. Accordingly, we propose to determine that the Plan 

requires the annual incremental reductions in emissions of direct PM2.5 and relevant PM2.5 precursors 

that are necessary for the purpose of ensuring attainment of the 1997 24-hour and annual PM2.5 standards 

by 2018 and 2020, respectively, in accordance with the requirements of CAA sections 171(1) and 

172(c)(2). 

Quantitative Milestones 

Although the RFP emission levels identified in the Plan for the 2017 and 2020 milestone years 

represent generally linear progress toward attainment by 2018 and 2020, the Plan as originally submitted 

in June 2015 does not identify an objective means for evaluating the area’s compliance with these 

emission targets or progress toward attainment, other than through 2017 and 2020 emissions levels and 
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CARB’s commitment to report on the “status of any emission reduction commitments” in the Plan. We 

note that the Plan contains only one emission reduction commitment: to adopt amendments to District 

Rule 4692 (“Commercial Charbroiling”) in 2016 and to achieve 0.4 tpd of direct PM2.5 emission 

reductions through implementation of this amended rule or a substitute rule achieving equivalent 

emission reductions.504 Such a milestone would not provide an adequate means to evaluate progress 

toward attainment of the PM2.5 NAAQS in the SJV, consistent with RFP requirements. 

In the QM Letter, however, CARB committed to adopt and submit, no later than December 31, 

2016, a revision to the 2015 PM2.5 Plan that identifies specific milestones demonstrating progress toward 

attainment of the 24-hour PM2.5 standard by December 31, 2018 and the annual PM2.5 standard by 

December 31, 2020. The QM Letter describes the specific components of this SIP revision that CARB 

will adopt and submit by December 31, 2016, including milestones to track implementation of specific 

SIP control measures and commitments, and air quality milestones to be achieved by the 2017 RFP 

milestone year and 2020 attainment year. Two of the control measures identified in the QM Letter are 

responsible for a significant portion of the NOx and direct PM2.5 emission reductions necessary for RFP 

and attainment: CARB’s Truck and Bus Rule and the District’s residential wood burning rule (Rule 

4901). Emissions from heavy heavy duty trucks and residential wood burning are the largest combustion 

sources of NOx and direct PM2.5 in San Joaquin Valley, and the Truck and Bus Rule and Rule 4901 

achieve the largest amounts of NOx and direct PM2.5 emission reductions, respectively, identified in the 

Plan’s attainment demonstration.505 The District’s commitment in the Plan to amend Rule 4692 

 

504 2015 PM2.5 Plan, Chapter 7, p. 7-6, and SJVUAPCD Governing Board Resolution 15-4-7A, paragraph 7. 

505 For stationary and area sources, “Residential Fuel Combustion” is the largest combustion source of direct PM2.5 in San 

Joaquin Valley (e.g., 9.4 tpd of the total 2012 winter average emissions of 61.0 tpd) and CARB’s Staff Report identifies Rule 

4901 as achieving the largest portion of the direct PM2.5 emission reductions for attaining 1997 PM2.5 NAAQS (e.g., 2.9 tpd 

of the Plan’s 6.6 tpd total winter average emission reductions from 2012 to 2018). 2015 PM2.5 Plan, Appendix B, p. B-2 and 

CARB Staff Report, p. 9. For all sources, “Heavy Heavy Duty Diesel Trucks (HHDV)” are the largest source of NOx in the 

San Joaquin Valley (e.g., 120.5 tpd of the total 2012 annual average emissions of 332.2 tpd) and the Plan estimates that the 
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(“Commercial Charbroiling”) in 2016 and to achieve 0.4 tpd of direct PM2.5 emission reductions through 

implementation of this amended rule or a substitute rule achieving equivalent emission reductions506

also accounts for a portion of the direct PM2.5 emission reductions necessary for RFP and attainment in 

the Plan.507 These implementation milestones, together with the updated emission inventories and air 

quality milestones for 2017 and 2020 that the State has also committed to identify as quantitative 

milestones in the SIP revision, would provide an objective means to evaluate the area’s progress in 

achieving not only the incremental emissions reductions but also the incremental air quality 

improvements necessary to attain the 24-hour and annual PM2.5 NAAQS by 2018 and 2020, 

respectively. 

 Under section 110(k)(4) of the Act, EPA may conditionally approve a plan revision based on a 

commitment by the State to adopt specific enforceable measures by a date certain but not later than 1 year 

after the date of the plan approval. Based on CARB’s commitments to submit the specific SIP revisions 

identified in the QM Letter by December 31, 2016, as discussed above, we propose to conditionally 

approve the quantitative milestone component of the 2015 PM2.5 Plan. 

We note that, consistent with the requirements of CAA section 189(c)(2) as interpreted in 

longstanding EPA policy, each of the milestone reports due March 31, 2018 (for the December 31, 2017 

milestone date) and March 31, 2021 (for the December 31, 2020 milestone date) should include technical 

 

largest emission reductions of NOx during the attainment planning period, for which the Truck and Bus Rule is a significant 

driver, will result from this source category (e.g., 59.2 tpd of the 125.7 tpd annual average emission reductions from 2012 to 

2020). 2015 PM2.5 Plan, Appendix B, p. B-7 and CARB Staff Report, p. 9. 

506 2015 PM2.5 Plan, Chapter 7, p. 7-6, and SJVUAPCD Governing Board Resolution 15-4-7A, paragraph 7. 

507 The Plan estimates that the amendments to Rule 4692 will achieve 0.4 tpd of the Plan’s 5.2 tpd total annual average 

emission reductions of direct PM2.5 from 2012 to 2020. 2015 PM2.5 Plan, CARB Staff Report, p. 9. 
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support sufficient to document completion statistics for appropriate milestones, e.g., calculations and any 

assumptions made concerning emission reductions to date.508

G. Contingency Measures 

1. Requirements for Contingency Measures 

Under CAA section 172(c)(9), PM2.5 attainment plans must include contingency measures to be 

implemented if an area fails to meet RFP (“RFP contingency measures”) or fails to attain the PM2.5

standards by the applicable attainment date (“attainment contingency measures”). Under subpart 4, 

however, the EPA interprets section 172(c)(9) in light of the specific requirements for particulate matter 

nonattainment areas. Section 189(b)(1)(A) differentiates between attainment plans that provide for 

timely attainment and those that demonstrate that attainment is impracticable. The 2015 PM2.5 Plan is a 

Serious area plan that demonstrates attainment of the 1997 24-hour PM2.5 NAAQS by December 31, 

2018 and attainment of the 1997 annual PM2.5 NAAQS by December 31, 2020, and thus, must include

contingency measures for RFP and attainment. 

The purpose of contingency measures is to continue progress in reducing emissions while a state 

revises its SIP to meet the missed RFP requirement or to correct continuing nonattainment. The principle 

requirements for contingency measures are:509

• Contingency measures must be fully adopted rules or control measures that are ready to be 

implemented quickly upon failure to meet RFP or failure of the area to meet the relevant 

NAAQS by the applicable attainment date. 

 

508 Addendum at 42017. 

509 General Preamble at 13543-13544 and Addendum at 42014-42015. 
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• The SIP should contain trigger mechanisms for the contingency measures, specify a schedule for 

implementation, and indicate that the measures will be implemented without further action by the 

State or by the EPA. In general, we expect all actions needed to affect full implementation of the 

measures to occur within 60 days after EPA notifies the State of a failure. 

• The contingency measures should consist of other control measures for the area that are not 

already relied upon to demonstrate attainment (e.g., to meet RACM/RACT, BACM/BACT, or 

MSM requirements) or to meet RFP. 

• The measures should provide for emissions reductions equivalent to approximately one year of 

reductions needed for RFP calculated as the overall level of reductions needed to demonstrate 

attainment divided by the number of years from the base year to the attainment year. 

Finally, we note that contingency measures can include federal, state, and local measures that are 

already scheduled for implementation or already implemented that provide for additional emissions 

reductions that are not relied on to demonstrate RFP or attainment. In other words, contingency 

measures are intended to achieve reductions over and beyond those relied on in the RFP and attainment 

demonstrations. Nothing in the CAA precludes a state from implementing such measures before they are 

triggered by a failure to meet RFP or a failure to attain by the applicable attainment date. EPA has 

approved numerous SIPs under this interpretation.510

 

2. Contingency Measures in the 2015 PM2.5 Plan 

 

510 See, for example, 62 FR 15844 (April 3, 1997) (direct final rule approving Indiana ozone SIP revision); 62 FR 66279 

(December 18, 1997) (final rule approving Illinois ozone SIP revision); 66 FR 30811 (June 8, 2001) (direct final rule 

approving Rhode Island ozone SIP revision); 66 FR 586 (January 3, 2001) (final rule approving District of Columbia, 

Maryland, and Virginia ozone SIP revisions); and 66 FR 634 (January 3, 2001) (final rule approving Connecticut ozone SIP 

revision); see also LEAN v. EPA, 382 F.3d 575 (5th Cir. 2004) (upholding contingency measures that were previously 

required and implemented where they were in excess of the attainment demonstration and RFP SIP). 
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The 2015 PM2.5 Plan addresses the contingency measure requirement in Chapter 6, section 6.4 

(“Contingency Measures”) of the Plan and in the CARB Staff Report, pages 26-27. Chapter 6, section 

6.4 addresses contingency measure requirements for the 2014 and 2017 RFP milestone years and for the 

2020 attainment year by discussing emission reductions to be achieved by already adopted measures, 

voluntary incentive programs, and inter-pollutant trading between PM2.5 and NOx for the 2020 

attainment year. The CARB Staff Report, p. 26-27, provides a brief statement on contingency measures 

for the 2018 attainment year for the 24-hour PM2.5 NAAQS and identifies several additional control 

measures to address the 2020 attainment year for the annual PM2.5 NAAQS. Chapter 6 states that a 

year’s worth of annual average emission reductions needed to demonstrate RFP (“One year’s worth of 

RFP”) is calculated by taking the overall level of emission reductions needed to demonstrate attainment 

and dividing it by the number of years between the base year and attainment year.511 Table 6-9 of the 

Plan (Contingency Emissions Reductions Target (tpd)) is reproduced below: 

 Contingency Need = “One year’s worth of RFP” 

Direct PM2.5 0.4 

NOx 15.7 

SOx 0 

Source: 2015 PM2.5 Plan, Chapter 6, Section 6.4, Table 6-9. 

Chapter 6 of the Plan identifies emission reductions to be achieved by the control strategy in the 

Plan in 2014 and 2017 that the District considers “surplus” to those reductions necessary to demonstrate 

RFP. The District states that these emission reductions are thus available to meet the contingency 

measure requirement.512 Table 6-10 of the Plan (Reductions Surplus to RFP for Contingency (tpd)), 

 

511 2015 PM2.5 Plan, Chapter 6, Section 6.4, p. 6-9, Table 6-9. 
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reproduced below, identifies the PM2.5 and NOx emission reductions in 2014 and 2017 that the District 

considers “surplus” to RFP requirements: 

Year 2014 2017 

RFP target 

emissions 

level 

Projected 

emissions 

inventory 

Contingency RFP target 

emissions 

level 

Projected 

emissions 

inventory 

Contingency 

PM2.5 65.2 63.3 1.9 64.0 62.5 1.5 

NOx 300.9 284.2 16.7 253.9 235.7 18.2 

Source: 2015 PM2.5 Plan, Chapter 6, Section 6.4, Table 6-10. 

For the 2020 attainment year, the Plan provides estimates of emission reductions projected in 

2021 from a combination of adopted state and local measures, including District Rules 4901, 4306, 

4308, and 4905 for direct PM2.5 and NOx and mobile source measures for several source categories for 

NOx.

513 Table 6-11 of the Plan identifies 1.6 tpd of direct PM2.5 and 12.0 tpd of NOx emission reductions 

as reductions that are available to meet the 2020 attainment contingency measure requirement. In order

to address a shortfall of needed NOx emission reductions, the District relies on inter-pollutant trading of 

direct PM2.5 emission reductions for NOx emission reductions at a ratio of 1:9 and, based on this 

analysis, concludes that there are sufficient emission reductions to meet the attainment contingency 

requirement.514 

The CARB Staff Report also addresses contingency measures for the 2020 attainment year. It 

identifies additional direct PM2.5 and NOx emission reductions to be achieved by the following control 

measures: ARB mobile source measures, the Portable Equipment Registration Program (PERP) and 

Airborne Toxic Control Measure (ATCM), Indirect Source Review (ISR) on-site mitigation (i.e., 

District Rule 9510), and the AERO515 rule (i.e., District Rule 4320). Based on these analyses, CARB 

 

513 2015 PM2.5 Plan, Chapter 6, Section 6.4, p. 6-11, Table 6-11.

514 2015 PM2.5 Plan, p. 6-12, Table 6-12. 

515 AERO stands for Advanced Emission Reduction Options for Boilers, Steam Generators, and Process Heaters Greater 

Than 5.0 MMBtu/hr. 
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concludes that the SIP control strategy achieves emission reductions sufficient to meet the attainment

contingency measure requirement for the annual PM2.5 NAAQS. 

Finally, for the 2018 attainment year for the 24-hour PM2.5 NAAQS, the CARB Staff Report 

states that “additional reductions in 2019 provide 0.2 tpd of PM2.5 and 10 tpd of NOx reductions” but 

does not identify the control measures that achieve these emission reductions.516 

3. EPA’s Evaluation of the 2015 PM2.5 Plan’s Contingency Measures 

The contingency measures portion of the 2015 PM2.5 Plan contains several deficiencies. 

First, the Plan incorrectly calculates one year’s worth of RFP emission reductions. Although 

Chapter 6 of the Plan correctly describes the required steps for calculating one year’s worth of annual 

average emission reductions needed to demonstrate RFP, the actual calculation in the Plan is based on 

2020 baseline emission reductions estimates517 rather than the attainment targets of 60.8 tpd of direct 

PM2.5 and 206.5 tpd NOx.

518 EPA recalculated one year’s worth of RFP emission reductions based on 

the attainment emission levels presented in the Plan, as shown in Table 12 below. 

Table 12. EPA’s Calculation of “One Year’s Worth of RFP” Using Attainment Emissions Levels 

 

Calculation of “One Year’s Worth of RFP” Using Attainment 

Emissions Levels (tpd) 

2012 Base Year 

Emissions (tpd) 

2020 Attainment 

Emissions (tpd) 

Total Emission 

Reduction (tpd) 

One Year’s Worth of RFP 

Emission Reductions (tpd) 

Direct PM2.5 66.0 60.8 5.2 0.65 

NOx 332.2 206.5 125.7 15.7 

SOx 8.1 7.8 0.3 0.0 

 

516 2015 PM2.5 Plan, CARB Staff Report, p. 27. 

517 See 2015 PM2.5 Plan, Chapter 6, Section 6.3, Table 6-6, Total Reductions Necessary to Reach Attainment (tpd). The 

“Attainment Emissions Level” used in Table 6-6 of the Plan reflect the projected emission inventory levels found in 

Appendix B Emission Inventory Tables, and does not reflect the attainment target levels identified by the CARB Staff 

Report, section II.B. Attainment Emission Levels, Table 1. 

518 CARB Staff Report, section II.B. Attainment Emission Levels, p. 9. 
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Source: 2015 PM2.5 Plan, Chapter 6, Section 6.4, Table 6-6 and CARB Staff Report, p. 9. 

Thus, according to EPA’s calculation, one year’s worth of RFP is 0.65 tpd of direct PM2.5, 15.7 

tpd of NOx and 0.0 tpd of SOx. The NOx and SOx values are essentially identical to the values identified 

in Chapter 6 of the Plan (and reproduced in Table 6-9 above), but EPA’s calculation of the direct PM2.5

emission reductions representing one year’s worth of RFP is significantly higher than the value 

identified in Chapter 6 of Plan. Consequently, the Plan significantly underestimates the direct PM2.5 

emission reductions necessary to satisfy contingency measure requirements. 

Second, the 2015 PM2.5 Plan does not provide an adequate basis for the State’s and District’s 

conclusion that the emission reductions identified for contingency measure purposes are in fact 

“surplus” to the reductions needed to demonstrate RFP and timely attainment (e.g., for RACM/RACT, 

BACM/BACT, or MSM). Section 6.4.2 of the Plan states that regulatory emission reductions to be 

achieved by 2014 and 2017 exceed the minimum emission reductions needed to demonstrate RFP in 

those years but does not provide a basis for the District’s conclusion that the identified emission 

reductions are not relied on to satisfy RFP requirements. Similarly, the Plan provides no support for 

either the District’s conclusion that “additional PM2.5 and NOx reductions occurring between 2020 and 

2021 can serve as attainment contingencies” or the State’s conclusion that “[f]or the interim 24-hour 

2018 attainment deadline, additional reductions in 2019 provide for 0.2 tpd of PM2.5 and 10 tpd of NOx

reductions.”519 

Third, two of the control measures identified in the CARB Staff Report as contingency measures 

– SJVUAPCD Rule 4320 (AERO Rule) and SJVUAPCD Rule 9510 (ISR On-Site Mitigation) – are not 

creditable for SIP purposes at this time. Rule 4320 (AERO Rule) is not SIP-creditable because it 

 

519 2015 PM2.5 Plan, Chapter 6, Section 6.4.2 and CARB Staff Report, p. 27. 
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contains provisions that allow owners and operators to pay a fee in lieu of complying with the rule’s 

emission limits and which render the NOx emission limits in the rule unenforceable.520 Rule 9510 (ISR 

On-Site Mitigation) is not SIP-creditable because it likewise contains provisions that allow project 

developers to pay fees instead of implementing on-site pollution mitigation plans.521 

Fourth, the contingency measure portion of the 2015 PM2.5 Plan indicates that the District is 

relying on “SIP-creditable incentive-based emissions reductions” to address contingency measure 

requirements but does not identify the specific incentive grant programs expected to provide the 

requisite emission reductions, nor does it provide the documentation and related enforceable 

commitments necessary to support a SIP submission that relies on incentive programs for SIP emission 

reduction credit.522

 

Finally, the contingency measure portion of the 2015 PM2.5 Plan does not discuss ammonia 

emissions or provide any basis for a conclusion that contingency measures for purposes of ammonia are 

not necessary to satisfy the statutory requirements. 

In sum, the 2015 PM2.5 Plan does not contain or identify SIP-creditable measures that are surplus 

to RFP and attainment needs and that are sufficient to achieve at least one year’s worth of emission 

reductions for each of the RFP and attainment years identified in the Plan. Accordingly, we propose to

disapprove the contingency measure portion of the 2015 PM2.5 Plan for failure to satisfy the 

requirements of CAA section 172(c)(9). 

H. Major Stationary Source Control Requirements Under CAA Section 189(e) 

 

520 75 FR 68294 (November 5, 2010) and 76 FR 16696 (March 25, 2011).

521 76 FR 26609 at 26612-26613 (May 9, 2011). 

522 The CAA requires that emission reductions resulting from incentive programs be “quantifiable, surplus, enforceable and 

permanent” in order to qualify for emission reduction credit in a SIP. See, e.g., “Improving Air Quality with Economic 

Incentive Programs,” U.S. EPA, Office of Air and Radiation, January 2001; see also 80 FR 19020 (April 9, 2015) (final 

action on SJVUAPCD Rule 9610). 
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Section 189(e) of the Act specifically requires that the control requirements applicable to major 

stationary sources of direct PM2.5 also apply to major stationary sources of PM2.5 precursors, except 

where the Administrator determines that such sources do not contribute significantly to PM2.5 levels that 

exceed the standards in the area.523 The control requirements applicable to major stationary sources of 

direct PM2.5 in a Serious PM2.5 nonattainment area include, at minimum, the requirements of a 

nonattainment new source review (NNSR) permit program meeting the requirements of CAA sections 

172(c)(5) and 189(b)(3).524 As part of our April 7, 2015 final action to reclassify the SJV area as Serious 

nonattainment for the 1997 PM2.5 standards, we established a May 7, 2016 deadline for the State to 

submit NNSR SIP revisions addressing the requirements of CAA sections 189(b)(3) and 189(e) of the 

Act.525 

California has not yet submitted the NNSR SIP revisions required to satisfy the subpart 4 

requirements for Serious nonattainment areas because they are not yet due. Accordingly, we are not 

proposing any action with respect to these requirements at this time. CARB submitted amendments to 

the SJVUAPCD’s NNSR rules in 2011 to address the 1997 PM2.5 NAAQS to ensure that new and 

modified major sources of PM2.5 undergo pre-construction review, and the EPA approved these NNSR 

SIP revisions on September 17, 2014.526

I. Motor Vehicle Emission Budgets 

1. Requirements for Motor Vehicle Emissions Budgets

Section 176(c) of the CAA requires federal actions in nonattainment and maintenance areas to 

conform to the SIP's goals of eliminating or reducing the severity and number of violations of the 

 

523 General Preamble at 13539 and 13541-42. 

524 CAA section 189(b)(1) (requiring that Serious area plans include provisions submitted to meet the requirements for 

Moderate areas in section 189(a)(1)). 

525 80 FR 18528 at 18533 (April 7, 2015). 

526 79 FR 55637 (September 17, 2014). 
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NAAQS and achieving expeditious attainment of the standards. Conformity to the SIP's goals means 

that such actions will not: (1) cause or contribute to violations of a NAAQS, (2) worsen the severity of 

an existing violation, or (3) delay timely attainment of any NAAQS or any interim milestone. 

Actions involving Federal Highway Administration (FHWA) or Federal Transit Administration 

(FTA) funding or approval are subject to the EPA's transportation conformity rule, codified at 40 CFR 

part 93, subpart A. Under this rule, metropolitan planning organizations (MPOs) in nonattainment and 

maintenance areas coordinate with state and local air quality and transportation agencies, EPA, FHWA, 

and FTA to demonstrate that an area's regional transportation plans (RTP) and transportation 

improvement programs (TIP) conform to the applicable SIP. This demonstration is typically done by 

showing that estimated emissions from existing and planned highway and transit systems are less than or 

equal to the motor vehicle emissions budgets (budgets) contained in all control strategy SIPs. An 

attainment, maintenance, or RFP SIP should include budgets for the attainment year, each required RFP 

milestone year, or the last year of the maintenance plan, as appropriate. Budgets are generally 

established for specific years and specific pollutants or precursors and must reflect all of the motor

vehicle control measures contained in the attainment and RFP demonstrations.527

PM2.5 plans should identify budgets for direct PM2.5, NOx and all other PM2.5 precursors whose 

on-road emissions are determined to significantly contribute to PM2.5 levels in the area for each RFP 

milestone year and the attainment year, if the plan demonstrates attainment. All direct PM2.5 SIP budgets 

should include direct PM2.5 motor vehicle emissions from tailpipes, brake wear, and tire wear. A state 

must also consider whether re-entrained paved and unpaved road dust or highway and transit 

construction dust are significant contributors and should be included in the direct PM2.5 budget.528

 

527 40 CFR 93.118(e)(4)(v). 

528 40 CFR 93.102(b) and 93.122(f); see also conformity rule preamble at 69 FR 40004, 40031-40036 (July 1, 2004). 
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Transportation conformity trading mechanisms are allowed under 40 CFR 93.124 where a SIP 

establishes appropriate mechanisms for such trades. The basis for the trading mechanism is the SIP 

attainment modeling which established the relative contribution of each PM2.5 precursor pollutant. 

In general, only budgets in approved SIPs can be used for transportation conformity purposes. 

However, section 93.118(e) of the transportation conformity rule allows budgets in a SIP submission to

apply for conformity purposes before the SIP submission is approved under certain circumstances. First, 

there must not be any other approved SIP budgets that have been established for the same time frame, 

pollutant, and CAA requirement. Second, the EPA must find that the submitted SIP budgets are 

adequate for transportation conformity purposes. To be found adequate, the submission must meet the 

conformity adequacy requirements of 40 CFR 93.118(e)(4) and (5). The transportation conformity rule 

does, however, allow for replacement of previously approved budgets by submitted motor vehicle 

emissions budgets that the EPA has found adequate, if the EPA has limited the duration of its prior 

approval to the period before it finds replacement budgets adequate.529

2. Motor Vehicle Emissions Budgets in the 2015 PM2.5 Plan 

The 2015 PM2.5 Plan includes budgets for direct PM2.5 and NOX for 2014 and 2017 (RFP 

milestone years), 2018 (projected attainment year for the 1997 24-hour NAAQS), and 2020 (projected 

attainment year for the 1997 annual NAAQS).530 The budgets were calculated using EMFAC2014, 

CARB’s latest version of the EMFAC model for estimating emissions from on-road vehicles operating 

in California.531 The SJV has eight separate county-based MPOs; therefore, separate budgets are 

 

529 40 CFR 93.118(e)(1). 

530 2015 PM2.5 Plan, Chapter 6, Section 6.5.4 (for 2014, 2017, and 2020 budgets) and 2018 Transportation Conformity 

Budgets for the San Joaquin Valley PM2.5 SIP Plan Supplement,” dated June 19, 2015, and adopted by ARB Board on July 

23, 2015, p. 4. 

531 EMFAC is short for EMission FACtor. EPA announced the availability of the EMFAC2014 model for use in state 

implementation plan development and transportation conformity in California on December 14, 2015. EPA's approval of the 

EMFAC2014 emissions model for SIP and conformity purposes was effective on the date of publication of the notice in the 
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provided for each MPO as well as a total for the nonattainment area as a whole. The budgets for 2014, 

2017, and 2020 reflect annual daily average emissions, and the budgets for 2018 reflect winter daily 

average emissions. Winter average day emissions are used for the 2018 budgets because SJV's 

exceedances of the PM2.5 24-hour NAAQS occur almost exclusively during the winter months and are 

linked with the District’s 2018 attainment demonstration for the 24-hour PM2.5 NAAQS. Annual average 

day emissions are used for the 2014 and 2017 budgets because the District has determined that annual 

average day budgets are the more protective of the two budgets options (i.e., annual versus 24-hour 

NAAQS) for the RFP milestone years when both standards apply, as is the case for the 2015 PM2.5 Plan. 

Annual average day emissions are used for the 2020 budgets because those emissions are linked with the

District’s attainment demonstration for the annual PM2.5 NAAQS. 

The direct PM2.5 budgets include tailpipe, brake wear, and tire wear emissions but exclude paved 

road, unpaved road, and road construction dust based on the District's conclusion that these source 

categories are insignificant contributors to PM2.5 levels in the SJV.532 The Plan does not include budgets 

for SO2, VOC, and ammonia. Under 40 CFR 93.102(b)(2)(v), the State is not required to include budgets 

for VOC, sulfur dioxide (SO2) and/or ammonia (NH3) unless EPA or the State has made a finding that 

transportation-related emissions of any of these precursors within the nonattainment area are a 

significant contributor to the PM2.5 nonattainment problem. The District considered on-road SO2, VOC, 

and ammonia emissions and concluded that it is not necessary to control on-road SO2, VOC, and 

ammonia emissions to attain the NAAQS. The District states in the Plan that on-road mobile exhaust 

estimates of SOx are less than 1 ton per day Valley-wide in the budget years; VOC emissions do not 

 

Federal Register. EMFAC2014 must be used for all new regional emissions analyses and CO, PM10 and PM2.5 hot-spot 

analyses that are started on or after December 14, 2017, which is the end of the grace period for EMFAC2014. 

532 Plan at Chapter 6, Section 6.5.3. 
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162 

contribute significantly to the formation of secondary PM2.5 in the SJV; and on-road mobile exhaust 

estimates of ammonia are less than 1 ton per day Valley-wide in the budget years.533

Table 13. MVEBs for the San Joaquin Valley for 1997 PM2.5 Standard

County 

2014 2017 2018 2020 

Annual average, 

tpd 

Annual average, 

tpd 

Winter average, 

tpd 

Annual average, 

tpd 

PM2.5 NOX PM2.5 NOX PM2.5 NOX PM2.5 NOX

Fresno 1.2 41.2 1.0 31.2 0.9 29.9 0.9 25.3 

Kern (SJV) 1.0 36.5 0.8 28.0 0.8 27.7 0.8 23.3 

Kings 0.2 7.6 0.2 5.7 0.1 5.5 0.1 4.8 

Madera 0.2 7.8 0.2 5.8 0.2 5.5 0.2 4.7 

Merced 0.4 13.9 0.3 10.7 0.3 10.3 0.3 8.9 

San Joaquin 0.7 19.6 0.6 14.9 0.6 14.4 0.6 11.9 

Stanislaus 0.5 15.6 0.4 11.9 0.4 11.4 0.4 9.6 

Tulare 0.5 14.9 0.4 11.9 0.4 10.3 0.4 9.6 

Totals a 4.8 157.0 3.8 119.0 3.6 115.0 3.5 96.8 

Sources: 2015 PM2.5 Plan, Chapter 6, p. 6-16; and Transportation Conformity Budgets for the 

San Joaquin Valley PM2.5 SIP, Plan Supplement, dated June 19, 2015, and adopted by ARB 

Board on July 23, 2015. 

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

rounding.

The 2015 PM2.5 Plan also includes a proposed trading mechanism for transportation conformity 

analyses that would allow future decreases in NOX emissions from on-road mobile sources to offset any 

on-road increases in PM2.5, using a NOX to PM2.5 ratio of 9:1.534 The State is proposing to use the same 

9:1 ratio that was in the 2008 PM2.5 Plan and approved by the EPA.535 

 

533 Id. 

534 2015 PM2.5 Plan, Chapter 6, p. 6-17. 

535 76 FR 69896 (November 9, 2011). 
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Using the same Community Multiscale Air Quality modeling application536 underlying the 

attainment demonstrations in the prior SJV 2008 PM2.5 Plan and the current 2015 PM2.5 Plan, CARB 

previously developed an equivalency ratio between emission reductions of direct PM2.5 and of NOX. For 

each pollutant, CARB modeled the ambient effect of a 10% reduction of emissions over the modeling 

domain. The concentration change per emission change gave a precursor effectiveness value for NOX

and an effectiveness value for direct PM2.5. The ratio of these two effectiveness values provided the 

NOX:PM2.5 trading ratio. 

To ensure that the trading mechanism does not affect the ability of the SJV to meet the NOX

budget, the NOX emission reductions available to supplement the PM2.5 budget would only be those 

remaining after the NOX budget has been met. Each MPO responsible for demonstrating transportation 

conformity must clearly document the calculations used in the trading, along with any additional 

reductions of NOx or PM2.5 emissions in the conformity analysis. 

3. Evaluation and Proposed Actions 

We have evaluated the budgets against our adequacy criteria in 40 CFR 93.118(e)(4) and (5) as 

part of our review of the budgets' approvability (see section V in the EPA’s General TSD for this 

proposal) and will complete the adequacy review of these budgets concurrent with our final action on 

the 2015 PM2.5 Plan.537 On September 18, 2015, the EPA announced the availability of the 2015 PM2.5

Plan with MVEBs and a 30-day public comment period. This announcement was posted on EPA's 

 

536 The EPA approved this air quality modeling as part of its approval of the attainment demonstration in the SJV PM2.5 Plan. 

See 76 FR 41338, 41349 and 76 FR 69896, 69924. 

537 Under the Transportation Conformity regulations, the EPA may review the adequacy of submitted motor vehicle emission 

budgets simultaneously with the EPA's approval or disapproval of the submitted implementation plan. 40 CFR 93.118(f)(2). 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

164 

Adequacy Web site at: http://www.epa.gov/otaq/stateresources/transconf/reg9sips.htm#ca. The comment 

period for this notification ended on October 19, 2015. 

Based on the information about re-entrained road dust in the Plan and in accordance with 40 

CFR 93.102(b)(3), we propose to concur with the District's finding that re-entrained road dust emissions 

from paved roads, unpaved roads, and road construction are not significant contributors to the PM2.5

nonattainment problem in the Valley and that these emissions therefore do not need to be addressed in 

the MVEBs (see discussion in section V.A.2 of this proposed rule). Additionally, based on the 

information about VOC, SO2, and ammonia emissions in the Plan and in accordance with 40 CFR 

93.102(b)(2)(v), we propose to find that it is not necessary to establish motor vehicle emissions budgets 

for transportation-related emissions of VOC, SO2, and ammonia to attain the 1997 PM2.5 standards in the 

SJV. 

For the reasons discussed in section V.E.2 of this proposed rule, we are proposing to approve the 

State's demonstration that it is impracticable to attain the 1997 PM2.5 NAAQS in the SJV by the 

applicable Serious area attainment date of December 15, 2015 and proposing to extend the attainment 

dates to December 31, 2018 and December 31, 2020 for the 24-hour and annual NAAQS, respectively. 

For the reasons discussed in sections V.E.v and V.F of this proposed rule, we are proposing to 

approve the RFP and attainment demonstrations in the 2015 PM2.5 Plan. The budgets, as given in Table 

13 of this proposed rule, are consistent with these demonstrations, are clearly identified and precisely 

quantified, and meet all other applicable statutory and regulatory requirements including the adequacy

criteria in 93.118(e)(4) and (5). For these reasons, the EPA proposes to approve the budgets listed in

Table 13 above. We provide a more detailed discussion in section V of the EPA’s General TSD, which 

can be found in the docket for today's action. 
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CARB has requested that we limit the duration our approval of the budgets only until the 

effective date of the EPA's adequacy finding for any subsequently submitted budgets.538 The 

transportation conformity rule allows us to limit the approval of budgets.539 However, we will consider a 

state's request to limit an approval of its MVEB only if the request includes the following elements:540

• An acknowledgement and explanation as to why the budgets under consideration have become 

outdated or deficient; 

• A commitment to update the budgets as part of a comprehensive SIP update; and 

• A request that the EPA limit the duration of its approval to the time when new budgets have been 

found to be adequate for transportation conformity purposes. 

Because CARB's request does not include all of these elements, we cannot at this time propose to 

limit the duration of our approval of the submitted budgets until new budgets have been found adequate. 

In order to limit the approval, we would need the information described above in order to determine 

whether such limitation is reasonable and appropriate in this case. Once CARB has adequately 

addressed that information, we intend to review it and take appropriate action. If we propose to limit the 

duration of our approval of the MVEB in the 2015 PM2.5 Plan, we will provide the public an opportunity 

to comment. The duration of the approval of the budgets, however, would not be limited until we 

complete such a rulemaking. 

We have previously approved motor vehicle emissions budgets for the 1997 annual and 24-hour 

PM2.5 NAAQS.541 These budgets will continue to apply for the 1997 PM2.5 NAAQS in the SJV area until 

we finalize our approval of the budgets in the 2015 PM2.5 Plan or find them adequate. 

 

538 Letter, Richard W. Corey, Executive Officer, California Air Resources Board, to Jared Blumenfeld, Regional 

Administrator, EPA Region 9, June 25, 2015. 

539 40 CFR 93.118(e)(1). 

540 67 FR 69141 (November 15, 2002), limiting our prior approval of MVEB in certain California SIPs. 

541 76 FR 69896, 69923 (November 9, 2011). 
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As noted above, the State included a trading mechanism to be used in transportation conformity 

analyses that would use the proposed budgets in the 2015 PM2.5 Plan as allowed for under 40 CFR 

93.124. This trading mechanism would allow future decreases in NOX emissions from on-road mobile 

sources to offset any on-road increases in PM2.5, using a NOX for PM2.5 ratio of 9:1. To ensure that the 

trading mechanism does not affect the ability to meet the NOX budget, the Plan provides that the NOX

emission reductions available to supplement the PM2.5 budget would only be those remaining after the 

NOX budget has been met. The Plan also provides that each MPO responsible for demonstrating 

transportation conformity shall clearly document the calculations used in the trading, along with any 

additional reductions of NOX or PM2.5 emissions in the conformity analysis. 

The EPA has reviewed the trading mechanism as described on page 6-17 in section 6.5.5 of 

Chapter 6 the 2015 PM2.5 Plan and finds it is appropriate for transportation conformity purposes in the 

San Joaquin Valley for the 1997 PM2.5 NAAQS. We note that the 9:1 NOX for PM2.5 ratio the State is 

proposing to use for transportation conformity purposes in the 2015 Plan is the same as previously 

approved by EPA in its action on the SJV 2008 PM2.5 Plan.542 We therefore propose to approve the 

trading mechanism with a NOX for PM2.5 trading ratio of 9:1 as enforceable components of the 

transportation conformity program for the SJV for the 1997 PM2.5 NAAQS. For further discussion of our 

evaluation of the 9:1 NOx for PM2.5 trading ratio for purposes of the Plan’s motor vehicle emission 

budgets, please see section IV.B of the EPA’s Interpollutant Trading Ratios TSD. 

VI. Summary of Proposed Actions and Request for Public Comment 

Under CAA sections 110(k)(3) and 110(k)(4), the EPA is proposing to approve, conditionally 

approve, and disapprove SIP revisions submitted by California to address the Act’s Serious area 

 

542 76 FR 69896 (November 9, 2011). 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

167 

planning requirements for the 1997 PM2.5 NAAQS in the San Joaquin Valley nonattainment area. 

Specifically, the EPA is proposing to approve the following elements of the 2015 PM2.5 Plan: 

1. the 2012 base year emissions inventories as meeting the requirements of CAA section 

172(c)(3); 

2. the best available control measures/best available control technology demonstration as 

meeting the requirements for RACM/RACT and BACM/BACT in CAA sections 172(c)(1), 

189(a)(1)(C), and 189(b)(1)(B); 

3. the attainment demonstration as meeting the requirements of CAA sections 172(c)(1) and 

189(b)(1)(A); 

4. the reasonable further progress demonstration as meeting the requirements of CAA section 

172(c)(2); 

5. the State’s application for an extension of the Serious area attainment date to December 31, 

2018 for the 1997 24-hour PM2.5 NAAQS and to December 31, 2020 for the 1997 annual PM2.5

NAAQS, as meeting the requirements of CAA section 188(e); 

6. the District’s commitment to amend and implement revisions to Rule 4692 (“Commercial 

Charbroiling”) for under-fired charbroilers in accordance with the schedule provided on page 7-6 of the 

2015 PM2.5 Plan to achieve the emissions reductions identified therein, as adopted in SJVUAPCD 

Governing Board Resolution 15-4-7A; and 

7. the 2014, 2017, 2018, and 2020 motor vehicle emissions budgets, as shown in Table 13 of this 

proposed rule, because they are derived from approvable attainment and RFP demonstrations and meet 

the requirements of CAA section 176(c) and 40 CFR part 93, subpart A. 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

168 

EPA is also proposing to approve the interpollutant trading mechanism provided in the 2015 

PM2.5 Plan for use in transportation conformity analyses, in accordance with 40 CFR 93.124, with the 

condition that trades are limited to substituting excess reductions in NOx emissions for direct PM2.5

emission reductions. 

Under CAA section 110(k)(4), the EPA is proposing to conditionally approve the quantitative 

milestones identified in the 2015 PM2.5 Plan because they do not fully satisfy the requirement for 

quantitative milestones in section 189(c) of the Act. Section 110(k)(4) authorizes the EPA to 

conditionally approve a plan revision based on a commitment by the State to adopt specific enforceable

measures by a date certain but not later than one year after the date of the plan approval. In this instance, 

the enforceable measures that the State must submit are enforceable quantitative milestones that enable 

the EPA to determine whether the area is meeting its reasonable further progress goals as contemplated

in the attainment plan and, if the area is not doing so, that enable the EPA to require the State to submit 

plan revisions to correct the deficiency. On December 15, 2015, CARB submitted a letter committing to 

submit a SIP revision containing specific quantitative milestones no later than December 31, 2016. If we 

finalize this proposed conditional approval, CARB must adopt and submit the SIP revisions it has 

committed to submit by December 31, 2016. If CARB fails to comply with this commitment, this 

conditional approval will convert to a disapproval and start an 18-month clock for sanctions under CAA

section 179(a)(2) and a two-year clock for a federal implementation plan (FIP) under CAA section 

110(c)(1). 

Finally, under CAA section 110(k)(3), the EPA is proposing to disapprove the contingency 

measure portion of the 2015 PM2.5 Plan because it does not fully satisfy the requirement for contingency 

measures in section 172(c)(9) of the Act. If we finalize the proposed disapproval, the offset sanction in 

CAA section 179(b)(2) would apply in the SJV PM2.5 nonattainment area 18 months after the effective 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

169 

date of final disapproval and the highway funding sanctions in CAA section 179(b)(1) would apply in 

the area 6 months after the offset sanction is imposed. Neither sanction would apply if California 

submits and the EPA approves, prior to the implementation of the sanctions, SIP revisions that correct

the deficiencies identified in the EPA’s final action. Additionally, the disapproval action would trigger 

an obligation on the EPA to promulgate a federal implementation plan unless California corrects the 

deficiencies, and the EPA approves the related plan revisions, within two years of the final action. 

We will accept comments from the public on these proposals for the next 30 days. The deadline 

and instructions for submission of comments are provided in the “Date” and “Addresses” sections at the

beginning of this preamble. 

VII. Statutory and Executive Order Reviews 

Additional information about these statutes and Executive Orders can be found at 

http://www2.epa.gov/laws-regulations/laws-and-executive-orders. 

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

Regulation and Regulatory Review 

This action is not a significant regulatory action and was therefore not submitted to the Office of 

Management and Budget (OMB) for review. 

B. Paperwork Reduction Act (PRA)

This action does not impose an information collection burden under the PRA because this action 

does not impose additional requirements beyond those imposed by state law. 

C. Regulatory Flexibility Act (RFA)
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

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I certify that this action will not have a significant economic impact on a substantial number of 

small entities under the RFA. This action will not impose any requirements on small entities beyond 

those imposed by state law. 

D. Unfunded Mandates Reform Act (UMRA)

This action does not contain any unfunded mandate as described in UMRA, 2 U.S.C. 1531–

1538, and does not significantly or uniquely affect small governments. This action does not impose 

additional requirements beyond those imposed by state law. Accordingly, no additional costs to State, 

local, or tribal governments, or to the private sector, will result from this action. 

E. Executive Order 13132: Federalism 

This action does not have federalism implications. It will not have substantial direct effects on 

the states, on the relationship between the national government and the states, or on the distribution of 

power and responsibilities among the various levels of government. 

F. Executive Order 13175: Coordination with Indian Tribal Governments

This action does not have tribal implications, as specified in Executive Order 13175, because the 

SIP is not approved to apply on any Indian reservation land or in any other area where the EPA or an 

Indian tribe has demonstrated that a tribe has jurisdiction, and will not impose substantial direct costs on 

tribal governments or preempt tribal law. Thus, Executive Order 13175 does not apply to this action. 

G. Executive Order 13045: Protection of Children from Environmental Health Risks and Safety Risks

The EPA interprets Executive Order 13045 as applying only to those regulatory actions that 

concern environmental health or safety risks that the EPA has reason to believe may disproportionately

affect children, per the definition of “covered regulatory action” in section 2-202 of the Executive Order. 
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2016. We have taken steps to ensure the accuracy of this version, but it is not the official version. 

171 

This action is not subject to Executive Order 13045 because it does not impose additional requirements

beyond those imposed by state law. 

H. Executive Order 13211: Actions that Significantly Affect Energy Supply, Distribution, or Use 

This action is not subject to Executive Order 13211, because it is not a significant regulatory 

action under Executive Order 12866. 

I. National Technology Transfer and Advancement Act (NTTAA)

Section 12(d) of the NTTAA directs the EPA to use voluntary consensus standards in its 

regulatory activities unless to do so would be inconsistent with applicable law or otherwise impractical. 

The EPA believes that this action is not subject to the requirements of section 12(d) of the NTTAA 

because application of those requirements would be inconsistent with the CAA. 

J. Executive Order 12898: Federal Actions to Address Environmental Justice in Minority Populations 

and Low-Income Population

The EPA lacks the discretionary authority to address environmental justice in this rulemaking. 

List of Subjects in 40 CFR Part 52

Environmental protection, Air pollution control, Ammonia, Incorporation by reference,

Intergovernmental relations, Nitrogen dioxide, Particulate matter, Reporting and recordkeeping 

requirements, Sulfur dioxide, Volatile organic compounds. 

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

___January 28, 2016.______ ___//signed//____________ 

Dated: Jared Blumenfeld, 

 Regional Administrator, 

Region 9.