Jared Blumenfeld, Regional Administrator, EPA Region 9 signed the following proposed rule on December 29, 

2014, 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 proposed rule, it is not the official version for purposes of public comment. 

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. EPA-R09-OAR-2014-0636.

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52 and Part 81

[EPA-R09-OAR-2014-0636; FRL- ]

Approval and Promulgation of Implementation Plans; Designation of Areas for Air Quality 

Planning Purposes; California; San Joaquin Valley Moderate Area Plan and 

Reclassification as Serious Nonattainment for the 2006 PM2.5 NAAQS 

AGENCY: U.S. Environmental Protection Agency.

ACTION: Proposed rule.

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

implementation plan (SIP) revisions submitted by California to address Clean Air Act (CAA or 

Act) requirements for the 2006 24-hour fine particulate matter (PM2.5) national ambient air 

quality standard (NAAQS) in the San Joaquin Valley (SJV) Moderate PM2.5 nonattainment area.

These SIP revisions are the 2012 PM2.5 Plan, submitted March 4, 2013, and the Supplement, 

submitted November 6, 2014. The EPA is also proposing to disapprove interpollutant trading 

ratios identified in these SIP submittals for nonattainment new source review permitting 

purposes. Finally, the EPA is proposing to reclassify the SJV area, including Indian country 

within it, as a Serious nonattainment area for the 2006 PM2.5 NAAQS based on EPA’s 

determination that the area cannot practicably attain this standard by the applicable Moderate 

area attainment date of December 31, 2015. Upon final reclassification as a Serious area,

California will be required to submit a Serious area plan including a demonstration that the plan 

provides for attainment of the 2006 PM2.5 NAAQS in the SJV area by the applicable Serious area 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

2

attainment date, which is no later than December 31, 2019, or by the most expeditious alternative 

date practicable, in accordance with the requirements of part D of title I of the CAA.

DATES: Any comments must arrive by [Federal Register Office: insert date 45 days after

date of publication in the Federal Register].

ADDRESSES: Submit comments, identified by docket number EPA-R09-OAR-2014-0636, by 

one of the following methods:

 Federal eRulemaking Portal: www.regulations.gov. Follow the on-line instructions.

 E-mail: tax.wienke@epa.gov.

 Mail or deliver: Wienke Tax, Office of Air Planning (AIR-2), U.S. Environmental 

Protection Agency Region 9, 75 Hawthorne Street, San Francisco, CA 94105.

Instructions: All comments will be included in the public docket without change and may be 

made available online at www.regulations.gov, including any personal information provided, 

unless the comment includes Confidential Business Information (CBI) or other information 

whose disclosure is restricted by statute. Information that you consider CBI or otherwise 

protected should be clearly identified as such and should not be submitted through 

www.regulations.gov or e-mail. The www.regulations.gov website is an “anonymous access” 

system, and the EPA will not know your identity or contact information unless you provide it in 

the body of your comment. If you send e-mail directly to the EPA, your e-mail address will be 

automatically captured and included as part of the public comment. If the EPA cannot read your 

comments due to technical difficulties and cannot contact you for clarification, the EPA may not 

be able to consider your comment.

Docket: The index to the docket (docket number EPA-R09-OAR-2014-0636) for this proposed 

rule is available electronically on the www.regulations.gov website and in hard copy at EPA 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

3

Region 9, 75 Hawthorne Street, San Francisco, California, 94105. While all documents in the 

docket are listed in the index, some information may be publicly available only at the hard copy 

location (e.g., copyrighted material), and some may not be publicly available at either location 

(e.g., CBI). To inspect the hard copy materials, please schedule an appointment during normal 

business hours with the contact listed in the FOR FURTHER INFORMATION CONTACT

section below.

FOR FURTHER INFORMATION CONTACT: Wienke Tax, Air Planning Office (AIR-2), 

U.S. Environmental Protection Agency, Region 9, (415) 947-4192, tax.wienke@epa.gov

SUPPLEMENTARY INFORMATION: Throughout this document, “we,” “us” and “our” 

refer to the EPA.

Table of Contents

I. Background for Proposed Actions

II. Clean Air Act Requirements for Moderate PM2.5 Nonattainment Area Plans

III. Clean Air Act Procedural Requirements for SIP Submittals

IV. Review of the San Joaquin Valley 2012 PM2.5 Plan and Supplement

A. Emissions Inventory

B. Air Quality Modeling

C. PM2.5 Precursors 

D. Reasonably Available Control Measures/Reasonably Available Control Technology

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

F. Adopted Control Strategy

G. Demonstration that Attainment by the Moderate Area Attainment Date is Impracticable

H. Reasonable Further Progress and Quantitative Milestones
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

4

I. Contingency Measures

J. Interpollutant Trading Ratios for Nonattainment New Source Review Permits

K. Motor Vehicle Emission Budgets

V. Reclassification as Serious Nonattainment and Serious Area SIP Requirements

A. Reclassification as Serious and Applicable Attainment Date

B. Clean Air Act Requirements for Serious PM2.5 Nonattainment Area Plans

C. Statutory Deadline for Submittal of the Serious Area Plan

VI. Reclassification of Indian Country

VII. Summary of Proposed Actions and Request for Public Comment

VIII. Statutory and Executive Order Reviews

I. Background for Proposed Actions

On October 17, 2006, the EPA revised the 24-hour national ambient air quality standard 

(NAAQS or standard) for PM2.5, particulate matter with a diameter of 2.5 microns or less, to 

provide increased protection of public health by lowering its level from 65 micrograms per cubic 

meter (μg/m3) to 35 μg/m3(40 CFR 50.13).

1 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. Individuals particularly sensitive to PM2.5 exposure include 

 

1 See 71 FR 61224 (October 17, 2006). The EPA set the first NAAQS for PM2.5 on July 18, 1997 (62 FR 36852), 

including annual standards of 15.0 μg/m3 based on a 3-year average of annual mean PM2.5 concentrations and 24-

hour (daily) standards of 65 μg/m3 based on a 3-year average of 98th percentile 24-hour concentrations (40 CFR 

50.7). In 2012, the EPA revised the annual standard to lower its level to 12 μg/m3(78 FR 3086, January 15, 2013, 

codified at 40 CFR 50.18). Unless otherwise noted, all references to the PM2.5 standard in this notice are to the 2006 

24-hour standard of 35 μg/m3 codified at 40 CFR 50.13.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

5

older adults, people with heart and lung disease, and children (78 FR 3086 at 3088, January 15, 

2013). 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 among precursor pollutants such as nitrogen oxides, sulfur oxides, volatile organic 

compounds, and ammonia (“secondary PM2.5”).2

Following promulgation of a new or revised NAAQS, the EPA is required by CAA section 

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

November 13, 2009, the EPA designated the SJV as nonattainment for the 2006 PM2.5 standard 

of 35 μg/m3(74 FR 58688, November 13, 2009). This designation became effective on 

December 14, 2009 (40 CFR 81.305). The SJV area is also designated nonattainment for the 

1997 annual and 24-hour PM2.5 standards.

3

The SJV PM2.5 nonattainment area is home to 4 million people and is the nation’s leading 

agricultural region. Stretching over 250 miles from north to south, 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. It 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. For a precise description of the geographic boundaries of the San Joaquin Valley PM2.5

nonattainment area, see 40 CFR 81.305. 

The local air district with primary responsibility for developing plans to attain the NAAQS in 

the area is the San Joaquin Valley Air Pollution Control District (SJVAPCD or District). The 

 

2 See 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.

3 See 70 FR 944 (January 5, 2005) and 40 CFR 81.305. In June 2008, California submitted the 2008 PM2.5 Plan to 

provide for attainment of the 1997 PM2.5 standards in the SJV. In November 2011, the EPA approved all but the 

contingency measures in the 2008 PM2.5 Plan (76 FR 69896, November 9, 2011). In July 2013, the State submitted a 

revised contingency measure plan, which the EPA approved in May 2014 (79 FR 29327, May 22, 2014).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

6

District works cooperatively with the California Air Resources Board (CARB) in preparing these 

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.

Ambient 24-hour PM2.5 NAAQS design value levels in the San Joaquin Valley are among the 

highest recorded in the United States for the 2011-2013 period.4 Exceedances of the 24-hour 

PM2.5 standard occur almost exclusively during the late fall and winter months from October to 

March, when ambient PM2.5 is dominated by ammonium nitrate (a secondary particulate formed 

from nitrogen oxides (NOx) and ammonia emissions) and directly-emitted particulates, such as 

wood smoke. During the winter, the SJV experiences extended periods of stagnant weather with 

cold foggy conditions which encourage wood burning and are conducive to the formation of 

ammonium nitrate (2012 PM2.5, Appendix G, pp. 7 to 9).

II. Clean Air Act Requirements for PM2.5 Moderate Nonattainment Area Plans

In April 2007, the EPA issued the Clean Air Fine Particle Implementation Rule (“2007 PM2.5

Implementation Rule”) to assist states with the development of SIPs to meet the Act’s attainment 

planning requirements for the 1997 PM2.5 standards (72 FR 20583, April 25, 2007, codified at 40 

CFR part 51, subpart Z). This rule was premised on the EPA’s prior interpretation of the Act as 

allowing for implementation of the PM2.5 NAAQS solely pursuant to the general nonattainment 

area provisions in subpart 1 of part D, title I of the CAA (“subpart 1”) and not the more specific 

provisions for particulate matter nonattainment areas in subpart 4 of part D, title I of the Act

 

4 See U.S. EPA, 2013 Design Value Reports, PM2.5 Detailed Information Updated 8/24/14, available at 

http://www.epa.gov/airtrends/values.html (“PM25_DesignValues_20112013_FINAL_08_28_14”) (hereafter “2013 

PM2.5 Design Value Reports”). “Design values” are the 3-year average NAAQS metrics that are compared to the 

NAAQS levels to determine when a monitoring site meets or does not meet the NAAQS. See 40 CFR part 50 

Appendix N, Section 1.0(c).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

7

(“subpart 4”). Among other things, the 2007 PM2.5 Implementation Rule included nationally 

applicable presumptions regarding the need to evaluate and potentially control emissions of 

certain PM2.5 precursors.5

In March 2012, the EPA issued a guidance document to aid states in preparing SIPs to meet 

the Act’s attainment planning requirements for the 2006 24-hour PM2.5 standard.

6 The 2012 

guidance was based, in large part, on the requirements in the 2007 PM2.5 Implementation Rule,

which the EPA based solely upon the statutory requirements of subpart 1.

California had three years from the effective date of SJV’s designation as nonattainment for 

the 2006 PM2.5 standard to submit a SIP for the SJV that addressed the applicable requirements 

of the Act.

7 On December 20, 2012, the District adopted the 2012 PM2.5 Plan to provide for 

attainment of the 2006 PM2.5 standard. On January 24, 2013, CARB adopted the Plan as an 

element of the California SIP and submitted it to the EPA on March 4, 2013.

On January 4, 2013, several weeks after the District’s adoption of the Plan, the U.S. Court of 

Appeals for the D.C. Circuit issued its decision in a challenge to the EPA’s 2007 PM2.5

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

 

5 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 (40 CFR 51.1002(c)(3), (4) and 72 FR 20586 at 20589-97 (April 25, 

2007)).

6 See Memorandum, dated March 2, 2012 (withdrawn June 6, 2013), from Stephen D. Page, Director, Office of Air 

Quality Planning and Standards, to EPA Regional Air Directors, Regions I-X re: “Implementation Guidance for the 

2006 24-Hour Fine Particle (PM2.5) National Ambient Air Quality Standards (NAAQS)” (“2012 Guidance”) 

Available at: http://epa.gov/ttn/naaqs/pm/pm25_guide.html.

7 See CAA section 172(b) and 40 CFR 51.1002(a).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

8

particulate matter nonattainment areas in subpart 4.

8 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 2007 PM2.5 Implementation Rule in its entirety, 

including the presumptions concerning VOC and ammonia in 40 CFR 51.1002, and instructed 

the EPA “to repromulgate these rules pursuant to Subpart 4 consistent with this opinion.”

Consistent with the NRDC decision, on June 2, 2014 (79 FR 31566), the EPA published a 

final rule classifying all areas currently designated nonattainment for the 1997 and/or 2006 PM2.5

standards as “Moderate” under subpart 4 and establishing a deadline of December 31, 2014 for 

states to submit any attainment-related and nonattainment new source review (NNSR) SIP 

elements required for these areas pursuant to subpart 4. The EPA provided its rationale for these 

actions in both the proposed and final classification/deadline rule.9

On September 18, 2014, the District adopted the “Supplemental Document, Clean Air Act 

Subpart 4: The 2012 PM2.5 Plan for the 2006 PM2.5 Standard and District Rule 2201 (New and 

Modified Stationary Source Review)” (“Supplement”) as a revision to the 2012 PM2.5 Plan. The 

District adopted the Supplement to address subpart 4 requirements for the 2006 PM2.5 standard to 

the extent that these requirements were not adequately addressed in the 2012 PM2.5 Plan. CARB 

submitted the Supplement to the EPA on November 6, 2014. The Supplement includes 

information on the implementation of reasonably available controls for ammonia sources in the

SJV and the District’s demonstration that attainment by the Moderate area attainment date of 

 

8 The NRDC decision also remanded the EPA’s 2008 final rule to implement the nonattainment New Source Review 

(NNSR) permitting requirements for PM2.5 (73 FR 28231, May 16, 2008) which, like the 2007 PM2.5

Implementation Rule, was premised on the requirements of subpart 1. Today’s proposal does not address

requirements for NNSR programs other than the requirements concerning PM2.5 precursors in CAA section 189(e), 

which we discuss in Section IV.C below, and PM2.5 interpollutant trading ratios, which we discuss in Section IV.J 

below.

9 See 79 FR 69806, 69809 (November 21, 2013) and 79 FR 31566, 31568 (June 2, 2014).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

9

December 31, 2015 is impracticable (“impracticability demonstration”). As a consequence of the 

NRDC decision, we are reviewing the 2012 PM2.5 Plan and Supplement for compliance with the 

applicable requirements of both subpart 1 and subpart 4. 

The EPA has longstanding guidance interpreting the subpart 4 requirements for particulate 

matter nonattainment areas (see “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) (“General Preamble”) and “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) (“Addendum”)). The General Preamble at 13538

discusses the relationship of subpart 1 and subpart 4 SIP requirements, and notes that SIPs for 

moderate nonattainment areas must meet the general provisions in subpart 1 to the extent that 

these provisions are not otherwise “subsumed by, or integrally related to, the more specific 

[subpart 4] requirements.” Some subpart 1 provisions have no subpart 4 equivalent (e.g., the 

emission inventories (CAA section 172(c)(3)) and contingency measures (CAA section 

172(c)(9)) and for these provisions, subpart 1 continues to govern. Other provisions of subpart 1 

are subsumed or superseded by more specific requirements in subpart 4 (e.g., certain provisions 

concerning attainment dates).

Because the 2012 PM2.5 Plan was initially developed and submitted to meet the requirements 

of subpart 1 and the 2007 PM2.5 Implementation Rule, certain elements of the Plan address 

provisions of subpart 1 rather than the applicable provisions of subpart 4. Specifically, these 

elements are the State’s request for an attainment date extension from 2014 to 2019 under CAA 

section 172(a)(2)(A); the demonstration of attainment by 2019; those portions of the reasonably 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

10

available control measure (RACM) demonstration that show there are no section 172(c)(1) 

RACM that would expedite attainment from 2019 to 2018; the transportation conformity motor 

vehicle emission budgets for 2019; and the contingency measures for failure to attain. We are not

proposing any action on these specific SIP elements at this time. 

As part of this proposal, the EPA is proposing to determine that the SJV cannot practicably 

attain the 2006 PM2.5 standard by the Moderate area attainment date of December 31, 2015 and 

to reclassify the area from Moderate to Serious nonattainment under subpart 4. Should the EPA 

finalize this proposal to reclassify the SJV area as a Serious area, the State will be required to 

adopt and submit a new plan addressing the Serious area requirements in subpart 4. We discuss 

these Serious area requirements in more detail in section V. below.

III. Clean Air Act Procedural Requirements for SIP Submittals

We are proposing action on two California SIP submittals. The first is the “2012 PM2.5 Plan,”

which the State submitted to EPA on March 4, 2013 (hereafter “2012 PM2.5 Plan” or “the 

Plan”)

10 and the second is the “Supplemental Document, Clean Air Act Subpart 4: The 2012 

PM2.5 Plan for the 2006 PM2.5 Standard and District Rule 2201 (New and Modified Stationary 

Sources),” which the State submitted to EPA on November 6, 2014 (hereafter “the 

Supplement”).11

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 submittal of a SIP or SIP 

revision. To meet this requirement, every SIP submittal should include evidence that adequate 

 

10 See Letter dated March 4, 2013, from James N. Goldstene, Executive Officer, California Air Resources Board, to 

Jared Blumenfeld, Regional Administrator, EPA Region 9, with enclosures.

11 See Letter dated November 6, 2014, from James N. Goldstene, Executive Officer, California Air Resources 

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

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

11

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 submittal of the 2012 PM2.5 Plan. The 

District conducted public workshops, provided public comment periods, and held a public 

hearing prior to the adoption of the Plan on December 20, 2012.

12 CARB provided the required 

public notice and opportunity for public comment prior to its January 24, 2013 public hearing on 

the Plan.

13 The SIP submittal includes proof of publication of notices for these public hearings. 

We find, therefore, that the 2012 PM2.5 Plan meets the procedural requirements for public notice 

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

The District adopted the Supplement after reasonable public notice and hearing.14 CARB 

adopted the Supplement for submittal as a SIP revision at its October 24, 2014 Board meeting

after reasonable public notice.

15

CAA section 110(k)(1)(B) requires the EPA to determine whether a SIP submittal 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 submittal. The EPA’s SIP completeness criteria are found in 40 

CFR part 51, Appendix V.

 

12 See 2012 PM2.5 Plan, p. ES-6 and SJVAPCD Governing Board Resolution 2012-12-19, “In the Matter of 

Adopting the San Joaquin Valley Unified Air Pollution Control District 2012 PM2.5 Plan,” December 20, 2012.

13 See CARB Resolution 13-2, “San Joaquin Valley PM2.5 State Implementation Plan,” January 24, 2013.

14 See Notice of Public Hearing to Adopt Supplemental Document to the 2012 PM2.5 Plan for the 2006 PM2.5 

Standard and New Source Review Rule to address Clean Air Act Subpart 4 requirements, available at 

http://www.valleyair.org/Air_Quality_Plans/docs/NPH_SD_PM25Plan_09_2014.pdf.

15 See CARB, Notice of Public Meeting to Consider the Supplemental Document for the San Joaquin Valley 24-

Hour PM2.5 SIP, September 23, 2014, and CARB Board Resolution 14-37, October 24, 2014.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

12

The March 4, 2013 submittal of the 2012 PM2.5 Plan became complete by operation of law 

on September 4, 2014. We find that the Supplement satisfies the completeness criteria in 40 CFR 

part 51, appendix V (see our Technical Support Document at section I.B).

IV. Review of the San Joaquin Valley 2012 PM2.5 Plan and Supplement

We summarize our evaluation of the 2012 PM2.5 Plan and Supplement below. Our detailed 

evaluation can be found in the Technical Support Document (TSD) for this proposal which is 

available online at www.regulations.gov in docket number EPA-R09-OAR-2014-0636, on EPA 

Region 9’s website at www.epa.gov/region9/air/sjv-pm25/index.html, or from the EPA contact 

listed at the beginning of this notice.

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 2006 24-hour PM2.5

standard, this includes direct PM2.5 as well as the main chemical precursors to the formation of 

secondary PM2.5: NOx, SO2, VOC, and ammonia (NH3). Primary PM2.5 includes condensable and 

filterable particulate matter.

A state should include in its SIP submittal documentation explaining how the emissions data 

were calculated. In estimating mobile source emissions, a state should use the latest emissions 

models and planning assumptions available at the time the SIP is developed. California is 

required to use EMFAC2011 to estimate tailpipe and brake and tire wear emissions of PM2.5, 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

13

NOx, SO2, and VOC from on-road mobile sources (78 FR 14533, March 6, 2013). States are 

required to use the EPA’s AP–42 road dust method for calculating re-entrained road dust 

emissions from paved roads (76 FR 6328, February 4, 2011).

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. 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 explaining how the 

emissions projections were calculated. 

2. Emissions Inventories in the 2012 PM2.5 Plan

The planning inventories for direct PM2.5 and all PM2.5 precursors (NOx, SO2, VOC, and

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

are found in Appendix B of the 2012 PM2.5 Plan. Winter daily average inventories, representing 

conditions in the period November through April, are provided for the base year 2007 and the 

baseline year of 2012 and each baseline year from 2014 to 2019. A winter inventory is used 

because exceedances of the 35 μg/m3 PM2.5 standard in the SJV occur mostly during the winter 

months (p. 3-4 and Appendix G, p. G-6). 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 

and Department of Finance as well as studies commissioned by the SJV’s metropolitan planning 

organizations (pp. B-21 to B-30).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

14

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

inventories use EMFAC2011 for estimating on-road motor vehicle emissions (p. B-26). After

EMFAC2011 was released in 2011, new information on statewide diesel fuel usage and 

economic forecasts became available to the State. For the 2012 PM2.5 Plan, CARB adjusted 

EMFAC2011 emissions estimates for heavy-duty trucks to reflect this new information (p. B26). The EPA allowed the use of these adjustment factors in transportation conformity 

determinations in the SJV.16 Re-entrained paved road dust emissions were calculated using the 

EPA’s AP-42 road dust methodology (Appendix B, p. B-25).

Table 1 provides a summary of the winter daily average inventories of direct PM2.5 and PM2.5

precursors for the base year of 2007. These inventories provide the basis for the control measure 

analysis and the RFP and attainment demonstrations in the 2012 PM2.5 Plan.

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

Precursors for the 2007 Base Year (winter daily average in tons)

Direct 

PM2.5

NOx SO2 VOC Ammonia

Stationary Sources 9.4 45.6 10.4 96.2 19.8

Area Sources 62.5 19.0 0.8 213.2 342.2

On-Road Mobile 

Sources 9.1 296.5 0.6 67.3 5.3

Off-Road Mobile 

Sources 6.1 103.9 1.0 38.0 0.0

Total 87.1 465.1 12.8 414.8 367.3

Source: 2012 PM2.5 Plan, Appendix B, Tables B-1 to B-5.

3. Evaluation and Proposed Action

The inventories in the 2012 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 

 

16 Letter dated January 14, 2014, Matthew Lakin, Chief, Air Planning Office, EPA-Region 9 to John Taylor, Branch 

Chief, Transportation Planning Branch, CARB; Subject: Use of San Joaquin Valley Heavy Duty Diesel Vehicle 

Recession Adjustment Methodology.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

15

developed in 2011 and 2012, including the latest EPA-approved version of California’s mobile 

source emissions model, EMFAC2011. 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 2007 base year emissions inventory in the 2012 

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 RACM, RFP, and 

impracticability demonstrations. 

B. Air Quality Modeling

1. Requirements for Air Quality Modeling 

CAA section 189(a)(1)(B) requires each state in which a Moderate area is located to submit a 

plan that includes a demonstration either (i) that the plan will provide for attainment by the 

applicable attainment date, or (ii) that attainment by that date is impracticable. The 2012 PM2.5

Plan and Supplement include a demonstration that attainment by the Moderate area attainment 

date is impracticable. 

Air quality modeling is used to establish emissions attainment targets, the combination of 

emissions of PM2.5 and PM2.5 precursors that the area can accommodate and still attain the 

standard, and to assess whether the proposed control strategy will result in attainment of the 

standard. Air quality modeling is performed for a base year and compared to air quality 

monitoring data collected during that year in order to determine model performance. Once the 

model performance is determined to be acceptable, future year changes to the emissions 

inventory are simulated with the model to determine the relationship between emissions 

reductions and changes in ambient air quality. To project future design values, the model 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

16

response to emission reductions, in the form of Relative Response Factors (RRFs), is applied to 

monitored design values from the base year.

For demonstrating attainment, the EPA’s recommendations for model input preparation, 

model performance evaluation, use of the model output for the attainment demonstration, and 

modeling documentation are described in Guidance on the Use of Models and Other Analyses for 

Demonstrating Attainment of Air Quality Goals for Ozone, PM2.5, and Regional Haze, EPA454/B-07-002, April 2007 (“Modeling Guidance”), as amended by “Update to the 24 Hour PM2.5

NAAQS Modeled Attainment Test,” Memorandum dated June 28, 2011, from Tyler Fox, Air 

Quality Modeling Group, OAQPS, EPA to Regional Air Program Managers, EPA (“Modeling 

Guidance Update”).17 The EPA has not issued modeling guidance specific to impracticability 

demonstrations but believes that a state seeking to make such a demonstration generally should 

provide air quality modeling similar to that required for an attainment demonstration. The main 

difference is that for an impracticability demonstration, the model’s projected design value on 

the required attainment date would be above the NAAQS, despite full implementation of the SIP 

control strategy including all reasonably available control measures (RACM). Alternatively, a 

model projection could show that the implementation of the SIP control strategy (including

RACM) results in attainment of the standard, but that this is achieved only after the applicable 

attainment date. We are using the latter alternative in evaluating the 2012 PM2.5 Plan, since its 

modeling focuses on an attainment year of 2019, instead of 2015, which is the Moderate area 

attainment year for this area under subpart 4 (CAA section188(c)(1)).18

 

17 The EPA Modeling Guidance and Modeling Guidance Update are available on EPA’s SCRAM web site, web 

page: http://www.epa.gov/scram001/guidance_sip.htm; direct links: 

http://www.epa.gov/scram001/guidance/guide/final-03-pm-rh-guidance.pdf and 

http://www.epa.gov/ttn/scram/guidance/guide/Update_to_the_24-hour_PM25_Modeled_Attainment_Test.pdf.

18 The District developed the Plan to address the requirements of subpart 1 as interpreted in the 2007 PM2.5 

Implementation Rule (prior to the D.C. Circuit’s remand of this rule in NRDC) which authorized the EPA to extend 

the attainment date as appropriate for a period no greater than 10 years from the date of designation, considering the 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

17

The EPA recommends that states prepare modeling protocols as part of their modeled 

attainment demonstrations (Guidance, p. 133). The Guidance (at pp. 133-134) describes the 

topics to be addressed in this modeling protocol. A modeling protocol should detail and 

formalize the procedures for conducting all phases of the modeling analysis, such as describing 

the background and objectives, creating a schedule and organizational structure, developing the 

input data, conducting model performance evaluations, interpreting modeling results, describing 

procedures for using the model to demonstrate whether proposed strategies are sufficient to 

attain the applicable standard, and producing documentation to be submitted for EPA Regional 

Office review and approval prior to actual modeling.

In addition to a modeled attainment demonstration, which focuses on locations with an air 

quality monitor, EPA’s Guidance describes an Unmonitored Area Analysis (UAA). This analysis 

is intended to ensure that a control strategy leads to reductions in PM2.5 at other locations that 

have no monitor but that might have base year and future baseline (projection year) ambient 

PM2.5 levels exceeding the standard.

Finally, as discussed below, the Modeling Guidance recommends supplemental air quality 

analyses. These may be used as part of a Weight of Evidence analysis (WOEA), which assesses 

attainment by considering evidence other than the main air quality modeling attainment test. 

While supplemental analyses can increase confidence in the reliability of the modeling, they are 

less important for evaluating the impracticability demonstration per se. That is, the level of rigor 

in the modeling analyses supporting the Plan’s conclusion that attainment will occur by 2019 is 

less important when the object is to demonstrate that attainment is not practicable by 2015. 

 

severity of nonattainment and the availability and feasibility of pollution control measures (see CAA section 

172(a)(2)(A) and 40 CFR 51.1004). Because the SJV areas was designated nonattainment effective December 14, 

2009 (74 FR 58688 (November 13, 2009), the date “10 years from the date of designation” would be December 14, 

2019.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

18

Supplemental analyses to support a demonstration of attainment by the end of 2019 will be 

necessary in a new Serious area plan. 

2. Air Quality Modeling in the 2012 PM2.5 Plan 

A brief description of the modeling in 2012 PM2.5 Plan and our evaluation of it follows. More 

detailed information about the modeling is available in section II.B. of the TSD. 

CARB and the District jointly performed the air quality modeling for the 2012 PM2.5 Plan. 

The modeling analysis uses the Community Multiscale Air Quality (CMAQ) photochemical 

model, developed by the EPA.19 It incorporates routinely available meteorological and air quality 

data collected during 2007. The MM5 (Mesoscale Model version 5) was used to prepare 

meteorological input for CMAQ. Air Quality modeling was performed only for the first and 

fourth quarters (Q1 and Q4) of 2007 which is sufficient for modeling the 2006 24-hour PM2.5

standard in the SJV because the high 24-hour PM2.5 concentrations occur only during the colder 

part of the year. Only the top 10 percent of modeled days is required for projecting the 98th 

percentile-based design values into the future. (Modeling Guidance Update, p. B-1) The 2012 

PM2.5 Plan’s modeling protocol is contained in Appendix F and includes descriptions of the 

photochemical modeling. Additional description of the photochemical modeling is also covered 

in the Weight of Evidence Analysis (”WOEA”).20 The protocol was reviewed by the EPA and a 

number of academic experts, and covers all of the topics recommended in the Guidance, 

 

19 The 2012 PM2.5 Plan also included receptor modeling source apportionment analyses, using both the Chemical 

Mass Balance (CMB) model and the Positive Matrix Factorization (PMF) model. These models distinguish the 

ambient PM2.5 contributions of several broad emissions source categories based on how they match the chemical 

species components of PM2.5 measurements. These results generally corroborated results from the photochemical 

modeling, but were not themselves part of the attainment demonstration.

20 The WOEA is Appendix B to the “[CARB] Staff Report, Proposed Revision to the PM2.5 State Implementation 

Plan (SIP) for the San Joaquin Valley,” Release Date: January 11, 2013 (“Staff Report”), which can be found in the 

docket for this proposed rule. Appendix G to the 2012 PM2.5 Plan also contains a weight of evidence analysis which 

is identical to the one in the CARB Staff Report except for the two additional appendices 5 and 6. 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

19

including thorough discussions of past modeling results and emission inventory preparation 

procedures. 

The air quality modeling and results are summarized in Chapter 4 of the Plan (section 4.5, p. 

4-22) and in the WOEA (section 10, p. 62). The Plan’s meteorological model and air quality 

model performance statistics and graphics are available from the CARB web site (“Meteorology 

and Air Quality Modeling for the 2012 24-Hour PM2.5 Plan for the San Joaquin Valley”, 

http://arb.ca.gov/eos/SIP_Modeling_PM25/24hr_PM25_ModelingPage.htm). The air quality 

model performance appears to be quite good, with bias within the criteria for acceptance, and 

usually within the original performance goals; performance is very good for total PM2.5 and for 

nitrate, the largest component of PM2.5; however, time series plots show that some high PM2.5

periods were underestimated.

The 2012 PM2.5 Plan included a UAA in Appendix 6 of the Weight of Evidence Analysis in 

Appendix G of the Plan (p.G-175). (ARB Staff Report Appendix B is identical to Plan Appendix 

G, except that it does not include the latter’s Appendices 5 and 6).

3. Evaluation of the Air Quality Modeling in the 2012 PM2.5 Plan

The modeling showed that existing State and District control measures are not sufficient to 

attain the 2006 PM2.5 standard by 2019 at all monitoring sites in the SJV. Modeling of the 

additional measures in the Plan (additional direct PM2.5 reductions from residential wood burning 

and from commercial charbroiling) showed attainment at all sites by 2019. Id.

Given the extensive discussion of modeling procedures, tests, and performance analyses 

called for in the Modeling Protocol and the good model performance, the EPA finds that the 

modeling is adequate for purposes of supporting the RACM demonstration, the RFP 

demonstration, and the demonstration of impracticability in the 2012 PM2.5 Plan and 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

20

Supplement. To satisfy the statutory requirements for a serious area attainment demonstration, 

however, the State will need to address documentation gaps outlined in the TSD (section II.B. of 

the TSD).

While the State included a UAA in the Plan, it makes no difference for the impracticability 

demonstration we are concerned with here. Any unmonitored peaks with concentrations higher 

than at the monitors would merely strengthen the case for attainment being impracticable by the 

required date. A demonstration that attainment is impracticable at monitor locations is sufficient 

to meet the requirements of section 189(a)(1)(B)(ii). The EPA finds that the supplemental 

analyses presented in the WOEA are useful in a weight of evidence analysis, and support the 

demonstration of the impracticability of attainment by 2015.

We note finally that existing ambient air quality monitoring data also support the modeled 

demonstration that attainment of the 2006 PM2.5 standard by December 31, 2015 is 

impracticable. Compliance with the 2006 24-hour PM2.5 standard is assessed using the three-year 

average of the yearly 98th percentile concentrations. The most recent monitored PM2.5

concentrations show that compliance with the 2006 standard is not possible by the end of 2015. 

See discussion in section II.F.3 of the TSD and section V.A. of this proposal. 

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 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

21

PM2.5, making them precursors to PM2.5.

21 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.22

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. 40 CFR 51.1002(c)(3), (4); see also 2007 

PM2.5 Implementation Rule, 72 FR 20586 at 20589-97 (April 25, 2007).

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. 

See NRDC v. EPA, 706 F.3d 428 (D.C. Cir. 2013). Although the court expressly declined to 

decide the specific challenge to these presumptions (see 706 F.3d at 437, n. 10 (D.C. Cir. 2013)), 

the court cited CAA section 189(e)23 to support its observation that “[a]mmonia is a precursor to 

 

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

22 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.

23 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.”
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

22

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.” 706 F.3d at 

436, n. 7 (citing CAA section 189(e)). Consistent with the NRDC decision, EPA now interprets 

the Act to require that under subpart 4, a state must evaluate all PM2.5 precursors for regulation

unless it provides a demonstration adequate to rebut the presumption for a particular precursor in 

a particular nonattainment area.

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 presumptively 

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 RACM and RACT, best available control 

measures (BACM) and best available control technology (BACT), most stringent measures, and 

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 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

23

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) and subpart 4

(see General Preamble, 57 FR 13498 at 13539-42), a state may demonstrate in a SIP submittal

that control of a certain precursor pollutant is not necessary in light of its insignificant 

contribution to ambient PM10 levels in the nonattainment area.24

We are evaluating the SJV 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 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 SJV PM2.5 Plan and Supplement

In the 2012 PM2.5 Plan, the State and District identify NOx, and SOx as the precursors that it 

must control in order to attain the 2006 PM2.5 standard in the San Joaquin Valley within 10 years

of the area’s designation as nonattainment for the PM2.5 NAAQS (i.e., by 2019).

25 Although no 

 

24 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).

25 This identification is made in the 2012 PM2.5 Plan, Appendix G, “PM2.5 Weight of Evidence Analysis” 

(“WOEA”) at pp. iv and 66, and in the CARB, “Staff Report, Proposed Revision to the PM2.5 State Implementation 

Plan (SIP) for the San Joaquin Valley,” Release Date: January 11, 2013 (“Staff Report”) at p. 9, which can be found 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

24

technical demonstration is necessary to support a conclusion consistent with the regulatory 

presumptions under subpart 4, the Plan nevertheless provides supporting evidence describing the 

need for NOx and SOx controls. The Plan states that further reductions in VOC and ammonia 

emissions would not contribute to attainment of the PM2.5 standard in the area and provides 

analyses to support this position. In the following, we discuss the technical basis that the District 

provided in the Plan to support its positions with respect to SO2, NOx, VOC, and ammonia.

a. SO2

The 2012 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. 

The 2012 PM2.5 Plan shows the measured contribution of SO2 emissions to ambient PM2.5

concentrations in pie charts portraying the contribution of various pollutant species. Depending 

on time period and location, the ammonium sulfate contribution is 6 to 9 percent,26 and the 

corresponding contribution of just the sulfate part of the ammonium sulfate molecules is 4 to 7 

percent of ambient PM2.5. The Plan’s “Weight of Evidence Analysis” (“WOEA”) also gives the 

ammonium sulfate portion of the 2007 design value concentration, 4.7 μg/m3at Bakersfield.27

The corresponding sulfate-only portion is 3.4 μg/m3. These contribution levels are substantial, 

although smaller than the contributions of some other components.

 

in the docket for this proposed rule. The WOEA is also included as Appendix B to the Staff Report.

26 2009-2010 peak day average in 2012 PM2.5 Plan Appendix A, Figures A-29 and A-30, p. A-52; 2009-2011 peak 

day average in WOEA Figure 7, p. 10.

27 WOEA at Table 5, p. 63
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

25

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

form of modeling results. The results from the sensitivity modeling is cited and discussed below 

in the NOx subsection. The SO2-specific results are that a 25% reduction in Valley-wide SO2

emissions would result in a 0.18 μg/m3decrease in ambient PM2.5 concentrations at the design 

value monitoring site, Bakersfield-California. It can also be inferred from the modeling that there 

is an ambient PM2.5 decrease of 0.08 μg/m3per ton of SO2 reduction (WOEA, Tables 6 and 7, p. 

65). The 0.18 μg/m3 PM2.5 decrease for a 25% SO2 reduction is considerably lower than the 3.75 

μg/m3decrease that would result from a 25% NOx reduction, but the 0.08 μg/m3 PM2.5 decrease 

per ton of emissions reduction is the same for SO2 as it is for NOx. The reason the 25% NOx 

reduction provides a larger reduction in ambient PM2.5 levels than a 25% SO2 reduction is 

simply that the NOx emission inventory for the area is much larger than the SO2 inventory. The 

2007 winter planning inventory for SO2 is just 12.8 tpd, whereas for NOx it is 465.1 tpd, more 

than 35 times larger (see 2012 PM2.5 Plan at Appendix B, Emission Inventory, grand totals in 

tables B-3 for SO2 and B-2 for NOx.) Even though the relatively small SO2 contribution to 

ambient PM2.5 concentrations leaves little 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.

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 2006 PM2.5 standard in the SJV, consistent with the requirements of subpart 4.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

26

b. NOx

The 2012 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 create ammonium nitrate, the largest component of ambient PM2.5

particles by species in the SJV.28 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 lines 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 ambient 

contributions, model simulations of NOx emission reductions, historical trends, and the relative 

amounts of NOx and ammonia.

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

substantial. Ammonium nitrate is the largest chemical component of ambient PM2.5 in the SJV, 

comprising 65 percent of the 2009-2011 average peak 24-hour PM2.5 concentration at 

Bakersfield (WOEA, p. 10). Using the 2009-2011 24-hour PM2.5 design value of 61.8 μg/m3,

29

the ammonium nitrate concentration on peak PM2.5 days is approximately 40.2 μg/m3. If only 

nitrate itself is considered (i.e., the nitrate part of the ammonium nitrate molecules), the 

 

28 2012 PM2.5 Plan Appendix A, Figures A-30 and A-29, p. A-52

29 See 2012 PM2.5 Plan, p. A-10. The design value for Bakersfield-California for 2009-2011 is given as a rounded 

value of 62 μg/m3 in Table A-5 in Appendix A of the Plan. For greater precision in estimating species contributions, 

we have used the unrounded value of 61.8 μg/m3calculated as the average of the 98th percentiles values for each 

year (66.7, 53.3, and 65.5) as listed in Table A-4.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

27

contribution of NOx represents approximately 50.3 percent of the 2009-2011 average peak 24-

hour PM2.5 concentration at Bakersfield, which is an ambient contribution of 31.1 μg/m3.

30

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 on the contribution of NOx to PM2.5 concentrations, the Plan 

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

PM2.5 concentrations go down when NOx emissions are reduced). The evidence is from 

modeling, historical trends, and relative proportions of NOx and ammonia. The 2012 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.

31 In the various studies, when NOx emissions were 

reduced by 50 percent, ambient ammonium nitrate decreased by 25 to 50 percent, depending on 

the episode modeled and the geographic location.32 Modeling for the 2012 PM2.5 Plan also shows 

substantial sensitivity of ambient PM2.5 concentrations to reductions in NOx emissions. In the 

Plan, the State modeled a 25 percent reduction in NOx emissions and showed a decrease in 

Bakersfield PM2.5 concentrations of 3.75 μg/m3, a 6 percent decrease in the 2009-2011 design 

 

30 The nitrate fraction of ammonia nitrate is calculated as molecular weight of nitrate (62) divided by the molecular 

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

31 The academic journal papers and are described in Appendix F, section 2.7 (p. 28), and in WOEA, section 5.c (p. 

64).

32 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., 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. 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.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

28

value of 61.8 μg/m3 and similar levels of ambient decreases at other monitors (WOEA, Table 6, 

p. 65). 

The 2012 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 4 and the WOEA of the Plan33. Daily NOx emissions 

levels and winter nitrate concentrations appear correlated over time on an annual basis. Both 

have decreased by about a third during the period 2004 to 2011. This is evidence that existing

NOx controls are effective at reducing ammonium nitrate. The evidence is strengthened by the 

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

the other precursor to ammonium nitrate, during the same period (Plan p. 4-8).

The 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, the Plan concludes

that NOx is the limiting precursor. The limiting precursor concept is illustrated briefly in Chapter 

4 and described more fully in the WOEA34. One molecule of 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.35

The WOEA includes plots (Figures 16 and 17, p. 19) of ammonia and nitric acid (which 

contains nitrate) concentrations at two monitoring sites in the SJV (Angiola and Fresno) that 

 

332012 PM2.5 Plan, Chapter 4, p. 4-8 and Figure 4-7, p. 4-10; more detail in WOEA section 9, p. 58, Figures 49 – 52

34 Chapter 4, Figures 4-4 and 4-5 (Plan, p. 4-9); WOEA, section 5b, p. 16. See also CARB Staff Report, p. E-3.

35 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 PM2.5 exceedances.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

29

were measured during the winter 2000-2001 CRPAQS36 study and reported in Lurmann et al.

(2006).

37 The Plan notes that 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. 

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 (p. 18, Table 1). In 2000, the amount of NOx available was only about two-thirds the 

amount of ammonia; in 2011 NOx was only one-third of ammonia. This shows the 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 EPA, the EPA agrees with the State’s and District’s conclusion that NOx controls must be 

included in the evaluation of potential control measures for the 2006 PM2.5 standard in the SJV, 

consistent with the requirements of subpart 4.

c. Ammonia

The 2012 PM2.5 Plan and Supplement state that “[b]ecause of the regional surplus in 

ammonia, even substantial ammonia emissions reductions yield a relatively small reduction in 

nitrate” (Plan p. 4-8) and that “ammonia reductions would not significantly contribute to the 

 

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

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

37 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.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

30

Valley’s attainment of the 2006 PM2.5 standard” (Plan p. 4-11). To support this finding, the Plan 

and Supplement 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 the NOx discussion, ammonium 

nitrate contributes 65 percent of the 2009-2011 average peak PM2.5 ambient levels at Bakersfield. 

Ammonium sulfate contributes an additional 7 percent (p. G-10; WOEA, p. 10). Thus, 

ammonium nitrate and ammonium sulfate together account for a total of 72 percent of the peak 

24-hour PM2.5 concentrations, or 44.5 μg/m3, and ammonia emissions are essential to the 

formation of both of these components of the ambient particulate matter. If only the ammonium 

portion of these molecules is considered, the corresponding figures are 16.6 percent of peak 

PM2.5 ambient levels, or 10.3 μg/m3.

38 This level of contribution is a substantial fraction of the 

SJV’s 2009-2011 design value of 61.8 μg/m3, and indicates that emissions of ammonia 

contribute significantly to ambient PM2.5 concentrations that exceed the 24-hour PM2.5 standard 

in the SJV.

Next we examine information in the Plan regarding the sensitivity of ambient PM2.5 levels in 

the SJV to ammonia emission control. On this issue there is conflicting evidence. Based on 

evidence that ammonia is not the limiting precursor and that modeled ammonia reductions are 

 

38 The ammonium fraction of ammonia nitrate is calculated as molecular weight of ammonium (18) divided by the 

molecular weight of ammonium nitrate (80) and equals 23.5 percent. The ammonium fraction of ammonia sulfate is 

calculated as molecular weight of ammonium portion (36) divided by the molecular weight of ammonium sulfate 

(132) and equals 27.3 percent.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

31

relatively ineffective, the Plan concludes that controls for ammonia are not warranted. However, 

a detailed evaluation of the modeling shows that ammonia controls can be effective at reducing 

ambient PM2.5 in some locations.

The Plan’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 so ambient PM2.5 would not be sensitive to ammonia reductions (WOEA, 

p. 16 - 20). The Plan notes that there is both an abundance of ambient ammonia relative to 

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

also indicates 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 (WOEA, p. 20 

and Figure 18). This abundance suggests that even under conditions favorable to ammonium 

nitrate formation, a substantial amount of unreacted ammonia remains. Based on these multiple 

pieces of evidence on the abundance of ammonia, the Plan concludes that ammonia is not the 

limiting factor for ammonium nitrate formation and, thus, that reducing ammonia emissions 

would not reduce ambient PM2.5 in the SJV. 

The 2012 PM2.5 Plan 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. Modeling for the 2012 PM2.5 Plan indicated that a 25 percent reduction in 

ammonia emissions resulted in a 0.55 μg/m3decrease in ambient PM2.5 (WOEA, p. 65, Table 6). 

This benefit is roughly one-seventh the corresponding benefit for a 25 percent reduction in NOx.

Id. Restating the inventory reduction percentages in terms of tons per day reductions, the Plan 

notes that reducing ammonia emissions by one ton per day is only about 10 percent as effective 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

32

as reducing one ton per day of NOx (Plan p. 4-11). Thus, based on this air quality modeling, the 

Plan concludes that additional ammonia control is considerably less effective than NOx control. 

The Plan also notes that, assuming the same rate of improvement in ambient PM2.5 

concentration per ton of ammonia reduced, it would take a 34 percent reduction in ammonia 

emissions to decrease ambient PM2.5 by 1 μg/m3, the amount that would have been needed to 

advance projected attainment by one year from 2019 to 2018. The Plan considers this to be “an 

infeasible amount, since there are no control strategies that exist or have been identified which 

could achieve such large reductions” (Plan, p. 4-11). 

The Plan assumes that additional ammonia control, as modeled, would provide limited 

benefit for attainment planning purposes. The Plan concludes, based upon the various 

information and analyses described above, that “ammonia reductions would not significantly 

contribute to the Valley’s attainment of the 2006 PM2.5 standard” (Plan p. 4-11), and therefore 

additional control measures should not be evaluated. 

After reviewing the information discussed above, EPA believes that the information provided 

by the State and District in the Plan and Supplement shows that ammonia contributes to a large 

fraction of measured PM2.5 concentrations in the SJV area, in the form of ammonium nitrate and 

ammonium sulfate. Additionally, modeling analyses submitted by the State and studies available 

to EPA indicate that although ammonia control is generally less effective at reducing PM2.5

concentrations when compared to NOx control, it remains true that reducing ammonia emissions 

in the SJV would reduce PM2.5 by varying amounts throughout the nonattainment area. 

Moreover, reductions in ammonia in conjunction with reductions of SO2 and NOx would help to 

provide for attainment of the NAAQS in the SJV.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

33

While EPA finds the modeling and other analyses presented in the 2012 PM2.5 plan to be 

credible, the fact remains that the modeling analyses 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 percent, ambient ammonium nitrate decreased by 5 to 25 

percent, depending on the episode modeled and the geographic location evaluated. (WOEA, p. 

64) These percentages for ammonia benefits are generally smaller than those for NOx reductions, 

but these modeling results show that reductions in ammonia emissions under certain 

circumstances can effectively reduce ambient PM2.5. The fact that all the modeling studies, 

including the modeling done for the current Plan, find at least some benefit from ammonia 

control shows that the concept of a “limiting precursor” 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 exclusively based on the 

control effectiveness of the precursor relative to other precursors, but should also consider 

whether emissions of the precursor “contribute significantly” to ambient PM2.5 levels which 

exceed the PM2.5 standard in the nonattainment area. 

Regarding the Plan’s statement that it would take a 34 percent reduction in ammonia 

emissions to decrease ambient PM2.5 by 1 μg/m3, the amount needed to advance attainment by 

one year from 2019 to 2018, EPA notes that the test for advancing the attainment date is based 

not on an evaluation of control measures for a single pollutant but rather on an evaluation of 

potential control measures for direct PM2.5 and all PM2.5 precursors from all types of sources in 

the nonattainment area. We also note that the appropriate inquiry in this context is whether 

reasonably available control measures would advance attainment by one year from 2015 to 2014 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

34

(not from 2019 to 2018), given under subpart 4 the applicable attainment date for the SJV area 

for the 2006 PM2.5 NAAQS is December 31, 2015.

In summary, the information provided by the State and District in the Plan and Supplement 

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. Additionally, 

modeled evidence submitted by the State and studies available to 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 some amount in parts of the 

Valley. Given the severity of the PM2.5 nonattainment problem in the SJV, the demonstration that 

attainment in SJV by 2015 is impracticable, and the documentation in the 2012 PM2.5 Plan 

showing that ammonia emissions are responsible for more than 10 μg/m3of ambient PM2.5

concentrations in the SJV area, EPA does not agree with the statement in the Plan that additional 

ammonia controls need not be evaluated to satisfy CAA requirements for the 2006 PM2.5

standard in the SJV. 

While stating that additional ammonia reductions are not necessary, the State nevertheless 

provided in the Supplement an evaluation of ammonia control measures currently implemented 

in the SJV and other potential ammonia control measures. We discuss the State’s ammonia 

control evaluation in section D, below (“Reasonably Available Control Measures/Reasonably 

Available Control Technology”).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

35

d. VOC

The 2012 PM2.5 Plan states that further reductions in VOC emissions would not contribute to 

PM2.5 attainment in the San Joaquin Valley. To support this finding, the Plan discusses the 

ambient contribution of VOC to measured PM2.5 levels in the Valley, 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, leading to the formation of 

particulate ammonium nitrate. The Plan’s Chapter 4 (p. 4-12) discussed both routes in section 

4.4.2. The WOEA discusses SOA in section 6 (WOEA, p. 32) and the oxidant route in section 5d 

(WOEA, p. 24).

For the direct contribution of VOC to PM2.5, SOA, the 2012 PM2.5 Plan states that modeling 

for annual average PM2.5 for the 2008 PM2.5 Plan found that anthropogenic SOA were about 3 to 

5 percent of total organic aerosol, and that SOA were mainly formed during the summer from 

nonanthropogenic sources. The winter anthropogenic contribution that is of interest for the 24-

hour PM2.5 standard would necessarily be lower, since SOA formation is less at winter 

temperatures, which are lower than the annual average. The Plan also cites a study by Chen et 

al.39 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 Fresno and 

 

39 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.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

36

Bakersfield of 2.46 and 2.28 μg/m3, respectively, which represent 6 percent and 4 percent of the 

total organic aerosol at those locations. Applying this roughly 5 percent SOA proportion to the 

organic carbon portion of the measured 2009-2011 winter PM2.5 composition shows that SOA is 

around 0.9 percent of total ambient PM2.5 at Bakersfield, and 1.5 percent of ambient PM2.5 at

Fresno.40 Because anthropogenic SOA is only a portion of the total, the portion due to 

controllable anthropogenic sources would be even less. These modeling studies show that SOA 

is not a substantial component of ambient PM2.5 in the SJV and that the potential for reducing 

ambient PM2.5 through VOC emission reductions is very limited.

For the indirect contribution of VOC to PM2.5, nitrate formation via daytime photochemistry, 

it appears 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.

41 The Plan reviews the 

same studies that the State relied on in the 2008 PM2.5 Plan for attainment of the 1997 PM2.5

standards (Plan Modeling Protocol, p.F-31). The EPA’s review of these studies and of the 2008 

PM2.5 Plan’s examination of them is covered in the TSD for the EPA’s final action on the 2008 

PM2.5 Plan.42 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 

 

40 The contribution of Organic Matter to 2009-2011 peak day PM2.5 levels was 17 percent at Bakersfield and 29 

percent at Fresno (see Staff Report, Appendix B, p. 10 [pdf.52], Figure 6. Five percent of these gives 0.85 percent 

SOA at Bakersfield and 1.45 percent at Fresno. As a fraction of the 2007 design values of 66 μg/m3at Bakersfield 

and 63 μg/m3at Fresno, these give SOA contributions of 0.56 and 0.91 μg/m3at Bakersfield and Fresno, 

respectively.

41 Pun, B.K., Balmori R.T.F, and Seigneur, C., 2009, Modeling Wintertime Particulate Matter Formation in Central 

California‖, Atmospheric Environment, 43: 402-409. doi: 10.1016/j.atmosenv.2008.08.040

42 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. 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

37

show VOC control has little benefit, or even a disbenefit. As detailed in that previous TSD and in 

the Plan’s Modeling Protocol, 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 

Protocol also suggested that there is sufficient background ozone flowing in from outside the 

SJV area to perform the oxidizing role, even in the absence of oxidants generated from VOC

emissions within the SJV,43 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.

Added to this evidence from past studies is the 2012 Plan’s current modeling, which

indicates a disbenefit from controlling VOC at important geographic locations. This is shown by 

negative PM2.5 sensitivities (that is, decreased VOC emissions result in increased PM2.5 levels) 

for multiple locations.44 In addition, diagrams of model PM2.5 response at Bakersfield to various 

combinations of NOx and VOC reductions show graphically that VOC reductions increase 

PM2.5, for any given level of NOx.

45 For all the monitoring sites, these NOx vs. VOC diagrams

show either no decrease or an actual increase in PM2.5 as VOC emissions are reduced. The 

 

43 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)

44 See VOC columns of WOEA Tables 6 and 7 (p. 65) for Bakersfield, Visalia, Corcoran, and Merced.

45 WOEA Figure 54 (p. 67) shows the model PM2.5 response at Bakersfield 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 Plan presents similar diagrams in Chapter 4, Figures 

4-15 through 4-23 (pp. 4-31ff) for the various monitoring sites.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

38

current modeling provides strong evidence that additional VOC reductions would not decrease 

ambient PM2.5 concentrations in the SJV.

In sum, the information provided by the State and District in the Plan and Supplement shows

that: a) wintertime levels of secondary organic aerosol measured in the SJV are low and 

therefore the direct products of VOC emissions do not directly 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 directly contribute significantly to PM2.5 levels 

above the standard in the SJV. Based on this information, we propose to determine that at this 

time VOC emissions do not contribute significantly to ambient PM2.5 levels that exceed the 2006 

PM2.5 standard in the SJV nonattainment area. 

3. Proposed Action

Based on a review of the information provided by the District and other information available 

to EPA, we propose to determine that at this time VOC emissions do not contribute significantly 

to ambient PM2.5 levels which exceed the 2006 PM2.5 standard in the SJV and, therefore, that

VOCs may be excluded from the State’s evaluation of potential control measures for purposes of 

this standard in this area. Consistent with the regulatory presumptions under subpart 4, all other 

PM2.5 precursors (NOx, SO2, and ammonia) must be included in the State’s evaluation of 

potential control measures for the 2006 PM2.5 standard in the SJV area, including NNSR 

provisions to implement the requirements of subpart 4.

46 We discuss the State’s evaluation of 

 

46 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 NNSR requirements. We intend to evaluate the adequacy of SJV’s NNSR program for PM2.5

purposes in a separate rulemaking. 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

39

potential control measures for NOx, SO2, and ammonia, as well as direct PM2.5, in section D

(“Reasonably Available Control Measures/Reasonably Available Control Technology”).

D. Reasonably Available Control Measures/Reasonably Available Control Technology

1. Requirements for RACM/RACT

CAA section 172(c) under subpart 1 describes the general attainment plan requirement for 

RACM and RACT, requiring that attainment plan submissions “provide for the implementation 

of all reasonably available control measures as expeditiously as practicable (including such 

reductions in emissions from existing sources in the area as may be obtained through the 

adoption, at a minimum, of reasonably available control technology) and shall provide for 

attainment” of the NAAQS. The attainment planning requirements specific to PM2.5 under 

subpart 4 likewise impose upon states an obligation to develop attainment plans that require

RACM on sources of direct PM2.5 and those PM2.5 precursors determined to be subject to the 

RACM/RACT requirement. CAA section 189(a)(1)(C) requires that Moderate area PM2.5 SIPs 

contain provisions to assure that RACM are implemented by no later than 4 years after 

designation of the area. The EPA reads CAA sections 172(c)(1) and 189(a)(1)(C) together to 

require that attainment plans for Moderate nonattainment areas must provide for the 

implementation of RACM and RACT for existing sources of PM2.5 and PM2.5 precursors in the 

nonattainment area as expeditiously as practicable but no later than 4 years after designation.47

As part of the RACM/RACT analysis, all available controls should be evaluated, and reasonable 

controls should be adopted.

 

47 This interpretation is consistent with guidance provided in the General Preamble at 13540.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

40

The terms RACM and RACT are not specifically defined in the Act, nor do the provisions of 

subpart 4 specify how states are to meet the RACM and RACT requirements. In longstanding 

guidance, however, the EPA has interpreted the RACM requirement to include any potential 

control measure for a point, area, on-road and non-road emission source that is technologically 

and economically feasible (General Preamble at 13540) and is not “absurd, unenforceable, or 

impracticable” (General Preamble at 13560). The EPA has historically defined RACT as the 

lowest emission limitation that a particular stationary source is capable of meeting by the 

application of control technology (e.g., devices, systems, process modifications, or other 

apparatus or techniques that reduce air pollution) that is reasonably available considering 

technological and economic feasibility. See General Preamble at 13541 and 57 FR 18070, 

18073-74 (April 28, 1992). 

The EPA recommends that states use the following process to identify RACM/RACT:

1. Develop a comprehensive list of available control measures for all source categories in 

the nonattainment area. In developing this list, the state should identify existing control 

measures currently being implemented in the area and also include any control measures 

suggested in public comments. 

2. Remove from the list any measure that is unreasonable because emissions from the 

affected source or source category are insignificant (i.e., de minimis). The state should 

appropriately document any determination that a source or source category is 

insignificant. 

3. Evaluate each remaining available control measure for its “reasonableness,” considering 

technological and economic feasibility and any potentially adverse impacts. The state 

should provide a reasoned justification if it rejects a listed control measure as 

unreasonable. 

4. Include in its submitted Moderate area attainment plan, in enforceable form, each control

measure found to be reasonable unless the measure is already either federally 

promulgated, part of the state’s SIP, or otherwise creditable in SIPs. In areas that 

demonstrate attainment by the Moderate area attainment date, the state may justify 

rejection of an otherwise reasonable measure by demonstrating that the measure would 

not, individually or collectively with other reasonable measures being rejected, advance 

attainment by one year or more. For areas that demonstrate that attainment by the 

Moderate area attainment date is impracticable, the state must provide for the 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

41

implementation of all available control measures that are technologically and 

economically feasible.

See General Preamble at 13540-13544.

An evaluation of technological feasibility should include consideration of factors such as

a source’s process and operating conditions, raw materials, physical plant layout, and non-air 

quality and energy impacts (e.g., increased water pollution, waste disposal, and energy 

requirements) (57 FR 18070, 18073).

An evaluation of economic feasibility should include consideration of factors such as cost 

per ton of pollution reduced (cost-effectiveness), capital costs, and annualized cost (57 FR 

18070, 18074). Absent other indications, the EPA presumes that it is reasonable for similar 

sources to bear similar costs of emissions reductions. Economic feasibility of RACM and RACT 

is thus largely informed by evidence that other sources in a source category have in fact applied 

the control technology, process change, or measure in question in similar circumstances. Id.

2. RACM/RACT Analysis in the 2012 PM2.5 Plan

The 2012 PM2.5 Plan’s RACM/RACT evaluation for direct PM2.5, NOx and SO2 sources 

is summarized in section 9.2 (p. 9-3) and detailed in Appendices C (“Mobile Source Control 

Strategies”) and D (“Stationary and Area Source Control Strategy Evaluation”). RACM for 

ammonia sources is discussed in Attachment A of the Supplement. The Plan includes a short 

discussion of the District’s current VOC control measures (p. 5-17 and Supplement, p. 13) but 

includes no detailed evaluation of them. The treatment of VOCs is thus consistent with the 

District’s determination that additional VOC controls are not necessary in the SJV area for 

purposes of attaining the PM2.5 NAAQS.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

42

The evaluation of potential controls in the 2012 PM2.5 Plan is presented by source 

category. For stationary and area source categories, the evaluation is broken down by the current 

District rule or rules that apply to that source category. The evaluation also addresses a number 

of source categories that are not currently subject to emission controls (e.g., fireworks). See 2012 

Plan, Appendix D, p. D-163.

The following information is provided in Appendix D for each stationary or area source 

category or District rule or, for ammonia sources, in Attachment A to the Supplement:

 a description of the sources within the category or sources subject to the rule;

 base year (2007), current year (2012), and projected baseline year emissions (for every 

year from 2014 to 2019) in the source category or affected by the rule;

 a discussion of the current rule requirements and/or listing and discussion of existing 

rules, regulations, or other control efforts that address the source category; and

 identification and discussion of potential new controls, including in many cases, a 

discussion of the technological and economic feasibility of the new controls. Rules 

adopted by other agencies (including the EPA, South Coast AQMD, and Bay Area 

AQMD) are discussed and compared to existing SJV rules. Measures proposed by the 

public for the source category/rule are also identified and discussed. In addition, nonregulatory approaches to reducing emissions in each stationary and area source category 

are discussed, including the use of incentives, opportunities for technology advancement 

programs, policy initiatives, and education/outreach programs. 

The following information is provided in Appendix C for each major on- and off-road 

mobile source category:

 A description of the type of sources in the category;

 base year (2007), current year (2012), and projected baseline year emissions (for every 

year from 2014 to 2019) in the source category;

 a discussion of the current rule requirements and/or listing and discussion of existing 

rules, regulations, or other control efforts that address the source category; and

 identification and discussion of potential new controls. Measures proposed by the public 

for the source category/rule are also identified and discussed with the majority of this 

discussion presented in the responses to comments in Appendix I, pp. I-10 to I-13.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

43

Through this evaluation process, the District identified 5 new control measures for adoption. 

The 2012 PM2.5 plan includes enforceable commitments to adopt these measures. See 2012 PM2.5

Plan, section 5.3.1 (p. 5-21) and Table 2 below.

Table 2. SJVAPCD 2012 PM2.5 Plan Specific Rule Amendment Commitments

District 

Rule 

Number 

Measure Number & 

Description

Amend 

Date

Comply 

Date Rule Amendment Commitment

4308

Boilers, Steam 

Generators, and 

Process Heaters 

0.075 to <2 

MMBtu/hr

2013 2015

Lower the NOx emission limit for instantaneous water 

heaters in the size range of 0.075–0.4 MMBtu/hr from the 

current level of 55 ppmv to 20 ppmv.

4692 Commercial 

Charbroiling 2016 2017 Add requirements for under-fired charbroilers

4901

Wood Burning 

Fireplaces and Wood 

Burning Heaters

2016 2016/

2017

1. Lower the threshold level for calling wood-burning 

curtailments from 30 μg/m3 to ≥20 μg/m3 

2. Review the meteorological conditions that lead to 

elevated PM2.5, to prevent the buildup of PM2.5 that may 

lead to a potential exceedance day 

3. Consider expanding the wood burning season to include 

October and/or March 

4. Analyze the feasibility of allowing the use of the 

cleanest certified wood burning devices at specified 

curtailment levels.

4905

Natural Gas-Fired, 

Fan Type Residential 

Central Furnaces 

2014 2015

Lower the NOx emission limits for residential furnaces and 

examine the possibility of incorporating NOx limits for 

natural gas-fired, fan-type, commercial central furnaces 

into the rule

9610 SIP Creditability of 

Incentives 2013 2013 Establish appropriate mechanisms for the District to take SIP credit for eligible incentive programs

Source: 2012 PM2.5 Plan, p. 5-21, Table 5-3, and section 5.3.1.

The District also identified a number of source categories for which existing information is 

inadequate to determine the feasibility of additional controls. These categories and the additional 

controls to be studied are discussed in section 5.3.3. (p. 5-24). The schedule for these studies is 

given in Table 5-4 (p. 5-24).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

44

The Plan also includes descriptions of the District’s incentive programs (Chapter 6); its 

technology advancement program (Chapter 7), and its public outreach program (Chapter 8). 

The efforts by the SJV’s eight metropolitan planning organizations (MPO)48 to implement 

cost-effect transportation control measures (TCM) are described in Appendix C, section C-11-4 

(p. C-33). While no additional TCMs were identified by the MPOs, 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 percent of the CMAQ funds 

to projects that meet a minimum cost-effectiveness. During the comment period for the 2012 

PM2.5 Plan, a number of TCMs were suggested by the public for consideration. See Appendix I, 

pp. I-10 to I-13. The feasibility of these measures is discussed in the District’s responses to 

comments. Id.

The Supplement identifies three categories of ammonia (NH3) emission sources in the SJV, 

which are estimated to account for 96% of ammonia air emissions in the Valley – farming 

operations, including confined animal facilities (239.2 tpd), evaporation from agricultural 

fertilizers (66.1 tpd), and composting solid waste operations (20.5 tpd) (see Supplement at 11). 

Information presented in the Supplement then compares District rules for confined animal 

facility (CAF) and composting operations to analogous requirements in other areas and discusses 

water quality measures for agricultural fertilizer application that may also reduce air emissions 

(see generally Supplement at Attachment A).

 

48 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 the Kern Council of Governments.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

45

Farming operations: The Supplement states that the control measures in SIP-approved Rule 

4570 (Confined Animal Facilities, adopted 2010)

49 have a secondary benefit of limiting NH3

emissions and have reduced ammonia emissions by more than 100 tpd (see Supplement at A-2, 

citing Staff Report for June 2009 re-adoption of Rule 4570 (June 2009) at Appendix F). Rule 

4570 is a work practice rule that requires farmers to implement management practices (e.g., feed 

according to NRCS guidelines, remove manure from corrals at least four times per year) for 

different components of the CAF operation, such as feeding, milking parlors, housing/bedding, 

manure management and land application. Rule 4570 applies to livestock operations, including 

dairy, beef, poultry and swine, above certain size thresholds. The District assumes in its RACM 

analysis that, for most control measures, the ammonia control efficiencies are the same as the 

VOC control efficiencies. The District compares Rule 4570 to livestock rules in seven other 

California air districts, including the South Coast Air Quality Management District (SCAQMD), 

Bay Area Air Quality Management District (BAAQMD), and the Sacramento Metropolitan Air 

Quality Management District (SMAQMD). Based on a review of the number of work practices 

required by the other California rules, the District concludes that Rule 4570 is at least as 

stringent as the air quality rules for livestock operations in these other areas. In cases where the 

work practice standards in other rules may be more stringent than the requirements in Rule 4570, 

the District considers these measures beyond RACT or the emissions differences not significant 

(see, e.g., Supplement at A-7, noting frequency of mitigation requirements in South Coast Rule 

223, adopted June 2, 2006).

 

49 See 77 FR 2228 (January 17, 2012) (final rule approving Rule 4570 into the California SIP).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

46

The Supplement also compares Rule 4570 to the Idaho Department of Environmental 

Quality’s (IDEQ) dairy ammonia permit by rule, adopted in 2009 (Idaho rule).50 While Rule 

4570 is based on implementing a certain number of BMPs in specific categories, the Idaho rule is 

based on a “points” system, where each BMP is assigned a certain number of points based on 

control effectiveness. The District states that Rule 4570 is more stringent than the Idaho rule 

based on Rule 4570’s lower applicability threshold (e.g., 500 milking cows v. 1,638 cows 

(@1,400 lbs) for free stall/flush dairies), more stringent requirements and greater number of 

required mitigation measures (see Supplement at A-25 and A-29). The District also states that 

Rule 4570 is more stringent regarding temporary suspension and substitution of mitigation 

measures, and contains more stringent testing, monitoring and recordkeeping requirements. It 

also states that Rule 4570 is more stringent because it provides specific mitigation measures for 

various operations at dairies, while the Idaho rule is based on what the District characterizes as 

an “arbitrary” point system that does not guarantee a specific degree of control (see Supplement 

at A-24 to A-29).51

Fertilizer application: The Supplement identifies fertilizer application to crops as the second 

largest source of ammonia emissions in the Valley and suggests that research to identify 

maximum efficiency of nitrogen use for various crop types could lead to a reduction of excess 

nitrogen in the soil that is susceptible to leaching and volatilization. The Supplement also refers 

 

50 The Idaho rule requires dairy farms above specified threshold numbers of cows or animal units to register 

with Idaho DEQ and to implement industry best management practices (BMPs) to control ammonia emissions. A list 

of BMPs is contained in the rule. Each BMP is assigned a point value based on relative effectiveness in reducing 

ammonia. Dairy farms must employ BMPs totaling 27 points. See Idaho Administrative Procedure Act (IDAPA) 

58.01.01 Sections 760-764: Rules for the Control of Ammonia from Dairy Farms (adopted March 30, 2007; 

amended May 8, 2009).

51 Citing IDEQ’s technical documentation for the Idaho rule, the Supplement states that the Idaho rule’s point 

system is “arbitrary” and that overall ammonia emission reductions from the rule may not be substantial given the 

flexibility in the rule and the absence of a direct correlation between the points required and the amount of emission 

reductions achieved (see Supplement at A-25). 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

47

to a “Regional Board General Order” issued by the Central Valley Regional Water Quality 

Control Board as a control measure that has “significantly reduced losses of nitrogen compounds 

to the environment, including leaching of nitrogen compounds to groundwater and air emissions 

such as ammonia and nitrous oxide” (Supplement at A-25 to A-27).52 The Supplement does not, 

however, identify any state or local air pollution control measure that limits ammonia emissions 

from fertilizer application operations.

Composting: The District compares its two SIP-approved composting rules, Rule 4566 

(Organic Water Materials, adopted in 2011)

53 and Rule 4565 (Biosolids, Animal Manure, and 

Poultry Litter Operations, adopted in 2007),54 to analogous rules adopted by the SCAQMD, Rule 

1133.3 (Emission Reductions from Greenwaste Composting Operations, adopted in 2011) and 

Rule 1133.2 (Emission Reductions from Co-Composting Operations, adopted in 2003). For this 

analysis, the District assumes that ammonia control efficiencies achieved by these rules are the 

same as the VOC control efficiencies. In its comparison of Rule 4566 with SCAQMD Rule 

1133.3, the District acknowledges that Rule 1133.3 has a much lower size threshold for 

implementing most stringent controls (80% control efficiency) but notes that neither SCAQMD 

nor the District currently has any facilities that trigger the most stringent controls. Therefore, the 

District states that, in practice, the controls are equivalent. In its comparison of Rule 4565 with 

SCAQMD Rule 1133.2, the District finds that the controls in Rule 4565 are generally more 

stringent than Rule 1133.2 for small facilities but less stringent than Rule 1133.2 for large 

 

52 See Reissued Waste Discharge Requirements General Order for Existing Milk Cow Dairies, California 

Regional Water Quality Control Board Central Valley Region Order R5-2013-0122, October 3, 2013, available at 

http://www.waterboards.ca.gov/centralvalley/board_decisions/adopted_orders/general_orders/r5-2013-0122.pdf

53 See 77 FR 71129 (November 29, 2012) (final rule approving Rule 4566 into California SIP).

54 See 77 FR 2228 (January 17, 2012) (final rule approving Rule 4565 into California SIP).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

48

facilities. The Supplement states that the most stringent measures in Rule 1133.2 are not costeffective for facilities in the Valley. 

3. Evaluation and Proposed Action

The process followed by the District in the 2012 PM2.5 Plan and Supplement to identify 

RACM/RACT is generally consistent with the EPA’s recommendations in the General Preamble. 

The process included compiling a comprehensive list of potential controls measures for sources 

of direct PM2.5, NOx, SO2, and ammonia in the SJV. This list included measures suggested in 

public comments on the Plan. See 2012 PM2.5 Plan, Appendices C, D, and I. No source 

categories were identified as insignificant except by implication for a few source categories of 

ammonia which collectively contributed less than 5 percent to the base year ammonia inventory 

(Supplement, p. A-1.) As part of this process, the District evaluated potential controls for all 

relevant source categories for economic and technological feasibility and provided justifications 

for the rejection of certain identified measures. Id. After completing this evaluation, the District 

included enforceable commitments to adopt and expeditiously implement those measures it 

found to be reasonable. See 2012 PM2.5 Plan, Table 5-3, p. 21 and Table D-1 above. Since 

submittal of the 2012 PM2.5 Plan in March 2013, the District has adopted all but two of these 

measures. One measure, amendments to Rule 4905 (Natural Gas-Fired, Fan Type Residential 

Central Furnaces) is scheduled for adoption this winter. The second measure, amendments to 

Rule 4692 (Commercial Charbroiling), is not scheduled until 2016. Research and development of 

cost-effective control technology are currently underway for certain measures in Rule 4692, the 

addition of PM2.5 emission limits for under-fired charbroilers (Plan, p. 5-22 and Supplement, p. 

8).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

49

We have reviewed the District’s determination in the 2012 PM2.5 Plan that its stationary and 

area source control measures represent RACM/RACT for direct PM2.5, NOx, and SO2. As 

discussed in Section II.C. of the TSD, the EPA is proposing to determine that at this time, VOCs 

do not contribute significantly to ambient PM2.5 levels that exceed the 2006 PM2.5 standard in the 

SJV and that a VOC control evaluation therefore is not necessary for purposes of this standard in 

this area. 55 In our review, we relied mainly on our previous evaluations of the District’s rules in 

connection with our approval of the SJV RACT SIP for the 1997 8-hour ozone standard, our 

comments on the 2012 PM2.5 Plan, and our comments on the District’s RACT SIP for the 2008 

8-hour ozone standard.56 We also reviewed measures suggested by the public in comments on 

the 2012 PM2.5 Plan. Based on this review, we believe that the District’s rules provide for the 

 

55 VOC sources in the San Joaquin Valley are currently subject to a broad range of controls measures adopted 

by the District and CARB as part of their strategy to attain the ozone standards in the area. The SJV is currently 

designated nonattainment and classified as extreme for the 1-hour ozone standard and for both the 1997 and 2008 8-

hour ozone standards. See 40 CFR § 81.305. Extreme ozone nonattainment areas are required by CAA section 

172(c)(1) to implement RACM for VOC sources and by section 182(b)(2) to the implement RACT for all major 

sources of VOC and certain other sources of VOC. A major source of VOC in an extreme ozone nonattainment area 

is a source that emits or has the potential to emit 10 tons per year or more of VOC (CAA section 182(e)) which is 

much lower than the 100 tpy threshold for major stationary sources in Moderate PM2.5 nonattainment areas (CAA 

section 302(j)). In 2012, the EPA approved the RACM demonstration in SJV’s SIP for attainment of the 1997 8-

hour ozone standard (77 FR 12652, 12670 (March 1, 2012)) and found that the State had met the section 182(b)(2) 

RACT control requirement for the 1997 8-hour ozone standards (limited approval, 77 FR 1417 (January 10, 2012); 

final corrective rule approval, 77 FR 71129 (November 29, 2012)).

As noted in the General Preamble, Congress recognized that PM precursors may be otherwise controlled and 

expressly recommended that the EPA consider other provisions of the CAA in addressing precursors (General 

Preamble at 13542, n. 22). Accordingly, the General Preamble provides that a state may demonstrate in a SIP 

submittal that control of VOC under other CAA requirements relieves it from the need to adopt additional controls 

for VOC as a precursor under section 189(e). Id. at 13542. 

56 See 77 FR 1417 (January 10, 2012); EPA Region 9, Technical Support Document for EPA’s Notice of 

Proposed Rulemaking for the California State Implementation Plan -EPA’s Evaluation of San Joaquin Valley 

Unified Air Pollution Control District’s Reasonably Available Control Technology (RACT) Demonstration for 

Ozone State Implementation Plan (SIP), Adopted April 16, 2009 (dated August 29, 2011); letter dated October 19, 

2012, from Kerry Drake, Associate Director, Air Division EPA-Region 9 to Samir Sheikh, SJVAPCD; and letter 

dated June 4, 2014, from Andrew Steckel, Chief, Rules Office, EPA Region 9 to Errol Villegas, Planning Manager, 

SJVAPCD.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

50

implementation of RACM/RACT for stationary and area sources of direct PM2.5, NOx, and 

SO2.

57

We have also reviewed the District’s analysis of current and potentially available ammonia 

controls for the three largest sources of ammonia emissions in the SJV: CAF operations, 

agricultural fertilizer application, and composting operations. Collectively these sources account 

for 96 percent of total base year (2007) ammonia emissions.58 See 2012 PM2.5 Plan, Appendix B, 

Table B-5.

Farming Operations and Composting: The District adopted Rule 4565, Rule 4566 and Rule 

4570 primarily to control VOC emissions, and EPA has determined that the control requirements 

in each of these rules represent RACT-level controls for VOCs. See 77 FR 2228 (January 17, 

2012) (final rule approving Rule 4565 and Rule 4570 into California SIP) and 77 FR 71129 

(November 29, 2012) (final rule approving Rule 4566 into California SIP). Although the 

Supplement does not provide a detailed analysis of the extent to which these rules also reduce

ammonia emissions, the District’s general conclusion that the work practice standards in these 

rules reduce ammonia emissions appears to be factually correct. The District’s evaluation of Rule 

4565, Rule 4566 and Rule 4570 generally supports a conclusion that these SIP-approved rules 

 

57 A full list of the District’s rules, including cites to our most recent final or proposed rulemaking on each can 

be found in Appendix B to the TSD. 

58 The balance of the ammonia inventory is spread among a number of source categories from electric utilities 

to gasoline-powered on-road vehicles. The largest of these sources, at 6.3 tpd in 2007 (1.7 percent of the total 

ammonia inventory), is the area source category “Other (Miscellaneous Processes).” See 2012 PM2.5 Plan, Appendix 

B, Table B-5. Ammonia emissions in this category are from domestic sources including pets, untreated human waste 

(e.g., diapers), and perspiration. See ENVIRON International Corporation, “Final Work Plan California Regional 

PM10/PM2.5 Air Quality Study - Ammonia Emissions Improvement Projects in Support of CRPAQS Aerosol 

Modeling and Data Analyses: Draft Ammonia Inventory Development,” April 13, 2001, p. 2-16, found at 

http://www.arb.ca.gov/ei/areasrc/nh3environworkplan.pdf.

We note that two of the remaining source categories (open burning and residential woodburning at a combined 

2.9 tpd in 2007) are covered by SIP-approved rules that prohibit and/or curtail burning and therefore also reduce 

ammonia emissions from these sources. 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

51

for CAFs and composting operations are as stringent as analogous rules implemented in other 

California districts.

With respect to the Idaho rule, because it is based on a point system and Rule 4570 is based 

on numbers of BMPs for different components of the CAF operation, it is difficult to compare 

the requirements in these two rules directly. Both rules contain options for controlling ammonia 

emissions in different parts of the CAF operation, but Rule 4570 may be more prescriptive in 

requiring a certain number of BMPs for each component, while the Idaho rule does not set a 

specific number of BMPs and instead requires that the points associated with the selected BMPs 

total to at least 27. It appears that in some respects Rule 4570 has more stringent provisions than 

the Idaho rule (e.g., rule applicability threshold, and provisions for temporary 

suspension/substitution, testing and records retention). On the other hand, the Idaho rule contains 

options (e.g., chemical amendments, lagoon nitrification/de-nitrification systems, lagoon covers, 

tunnel ventilation with biofilter, incorporation of manure within 24 hours of land application) 

that do not appear to be included in Rule 4570. It is not clear whether these control options are 

commonly implemented in Idaho or reasonably available or appropriate for use in the SJV.

In the absence of specific information regarding more stringent ammonia air emission control 

measures that may be technologically and economically feasible for implementation in the SJV 

area, we find the District’s evaluation of Rule 4565, Rule 4566 and Rule 4570 in comparison to 

analogous rules adopted elsewhere is adequate to demonstrate that the District is implementing 

all available control measures for ammonia emissions from CAFs and composting operations 

that are technologically and economically feasible for implementation in the SJV at this time. 

We note, however, that the District’s analyses of these rules appear to rest on certain 

assumptions concerning ammonia emissions reductions that are not supported by specific 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

52

documentation or analyses (e.g., assumptions concerning ammonia control efficiencies based on 

VOC control efficiencies). The point system in the Idaho rule appears to be based upon detailed 

scientific studies on the ammonia control efficiencies of the identified BMPs,59 some of which 

may be available for implementation in the SJV. We note also that the timing of the NRDC 

decision in early 2013 may have constrained the State’s and District’s ability to fully evaluate 

additional ammonia control measures as part of a RACM/RACT control strategy ahead of the 

applicable Moderate area attainment date (December 31, 2015). Taking these unique 

circumstances into account, we find the District’s ammonia control evaluation adequate for 

RACM/RACT purposes at this time but recommend that the State and District conduct a more 

thorough evaluation of all available ammonia control measures for farming and composting 

operations as part of its development of a Serious area plan. Specifically, we encourage the 

District to revisit its control evaluation for CAFs and composting operations at its earliest 

opportunity, both to specifically consider the ammonia control efficiencies and cost effectiveness 

of Rule 4565, Rule 4566 and Rule 4570, and to address any additional control options that may 

be technologically and economically feasible for implementation in the SJV, e.g., the BMPs 

identified in the Idaho rule and other control options identified by EPA or by citizens during the 

District’s rulemaking processes. 

Fertilizer application: Although certain water pollution control and other requirements 

contained in the “Regional Board General Order” cited in the Supplement may indirectly reduce 

ammonia emissions to the air from fertilizer application operations, these requirements have not 

 

59 IDEQ’s technical documentation indicates that under the Idaho rule, BMP points are awarded based on a 

detailed assessment of each BMP’s relative effectiveness in controlling ammonia emissions. See IDEQ, “Scientific 

Basis for the Control of Ammonia from Dairy Farms Best Management Practices,” July 18, 2006, available at 

http://www.deq.idaho.gov/media/635665-58_0101_0502_scientific_basis_final.pdf.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

53

been approved into the SIP for purposes of attainment of the NAAQS and therefore cannot 

provide a basis for approval of a RACM demonstration under the CAA. We are not aware, 

however, of ammonia air emission control measures that have been adopted and implemented for 

fertilizer application operations elsewhere. In the absence of information regarding air emission 

control measures for agricultural fertilizer application that may be technologically and 

economically feasible for implementation in the SJV area, we find the District’s analysis in the 

Supplement acceptable for RACM purposes at this time. We note also that the timing of the 

NRDC decision in early 2013 may have constrained the State’s and District’s ability to fully

evaluate additional ammonia control measures as part of a RACM/RACT control strategy ahead 

of the applicable Moderate area attainment date (December 31, 2015). Taking these unique 

circumstances into account, we find the District’s ammonia control evaluation adequate for 

RACM/RACT purposes at this time, but we encourage the District to revisit its control 

evaluation for fertilizer application at its earliest opportunity to specifically evaluate the technical 

and economic feasibility of potential air pollution control measures that may reduce ammonia 

emissions from fertilizer application in the SJV.

Mobile Sources: Finally, we have reviewed the analysis of current and potentially available 

controls for both on and off-road mobile sources in Chapter 5 and Appendix C. As we have 

noted in previous actions on SJV plans,60 California is a leader in the development and 

implementation of stringent control measures for on-road and off-road mobile sources. Its 

current program addresses the full range of mobile sources in the SJV through regulatory 

programs for both new and in use vehicles and through incentive grant programs. See 2012 PM2.5

 

60 The proposed approvals of the SJV 2007 [8-hour] Ozone Plan at 76 FR 57846, 57852 (September 16, 2011) and 

the 2008 PM2.5 Plan at 76 FR 41338, 41345 (July 13, 2011) include discussions of California’s control programs for 

mobile sources.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

54

Plan, Table 5-2 and Appendix A of the TSD. The District has also adopted measures to reduce 

emissions from mobile sources including its indirect source review rule (Rule 9510) and 

employer trip reduction rule (Rule 9410) and has a well-funded incentive grants program focused 

on mobile sources. See Chapter 6. The MPOs also have a program to fund cost-effective TCMs. 

See Appendix C, p. C-33. Overall, we believe that the State, District, and MPO programs provide 

for the implementation of RACM for PM2.5 and its precursors from mobile sources in the SJV.

For the foregoing reasons, we propose to find that the 2012 PM2.5 Plan and Supplement 

provide for the implementation of all RACM/RACT that can be implemented prior to the 

applicable Moderate area attainment date as required by CAA sections 189(a)(1)(C) and 

172(c)(1) and to approve the RACM/RACT demonstration in the Plan.

61

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

CAA section 189(e) specifically requires that the control requirements applicable to major 

stationary sources of direct PM2.5

62 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 standard in the area (General Preamble at 13539 and 13541 to 42).

The Supplement contains a discussion of the District’s Rule 2201 (New and Modified Stationary 

Source Review Rule) (Supplement at 17-20) and three potential major stationary sources of 

ammonia operating in the SJV (Supplement at A-39 to A-41). The EPA is not proposing to act 

 

61 The 2012 PM2.5 Plan is the latest in a series of air quality plans and control strategies that the District and CARB 

have adopted to provide for attainment of the NAAQS in the SJV. These plans include the 2003 PM10 Plan 

(approved 69 FR 30005 (May 26, 2004)); the 2004 Extreme [1-hour] Ozone Attainment Plan (approved 

75 FR 10420 (March 8, 2010), approval withdrawn 77 FR 70376 (November 26, 2012)); the 2007 [8-hour] Ozone 

Plan (approved 77 FR 12652 (March 1, 2012)); the 2008 PM2.5 SIP (approved 76 FR 69896 (November 9, 2011)); 

and the 2009 RACT SIP (limited approval January 10, 2012 (77 FR 1417); last corrective rule approval November 

29, 2012 (77 FR 71129)). 

62 The control requirements applicable to major stationary sources of direct PM2.5 in a Moderate area include, at 

minimum, the requirements of a nonattainment new source review (NNSR) permit program meeting the 

requirements of CAA section 172(c)(5) (see CAA 189(a)(1)(A)).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

55

on these components of the Plan at this time and will do so in a separate rulemaking to address 

the control requirements specific to major stationary sources of direct PM2.5 and PM2.5 precursors 

under section 189(e) in the SJV.

F. Adopted Control Strategy

1. Requirements for Control Strategies and Enforceable Commitments

CAA section 110(a)(2)(A) provides that each SIP “shall include enforceable emission 

limitations and other control measures, means or techniques... as well as schedules and 

timetables for compliance, as may be necessary or appropriate to meet the applicable 

requirement of the Act.” Section 172(c)(6) of the Act, which applies to nonattainment SIPs, is 

virtually identical to section 110(a)(2)(A).63 Measures necessary to meet RACM/RACT 

requirements should also be adopted by the State in an enforceable form (General Preamble at 

13541).

Generally, the EPA will approve a State plan that takes emissions reduction credit for a 

control measure only where the EPA has approved the measure as part of the SIP, or in the case 

of certain on-road and nonroad measures, where the EPA has issued the related waiver of 

preemption or authorization under CAA section 209(b) or section 209(e). The EPA has, 

however, approved enforceable commitments that are limited in scope where circumstances exist 

that warrant the use of such commitments in place of adopted measures. Commitments approved 

by the EPA under CAA section 110(k)(3) are enforceable by the EPA and citizens under 

CAA sections 113 and 304, respectively. In the past, the EPA has approved enforceable 

 

63 The language in sections 110(a)(2)(A) and 172(c)(6) is quite broad, allowing a SIP to contain any enforceable 

“means or techniques” that EPA determines are “necessary or appropriate” to meet CAA requirements, such that the 

area will attain as expeditiously as practicable, but no later than the designated date. Furthermore, the express 

allowance for “schedules and timetables” demonstrates that Congress understood that all required controls might not 

have to be in place before a SIP could be fully approved.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

56

commitments and courts have enforced actions against states that failed to comply with them.64

Additionally, if a state fails to meet its commitments, the EPA could make a finding of failure to 

implement the SIP under CAA section 179(a)(4), which starts an 18-month period for the state to 

correct the non-implementation before mandatory sanctions are imposed.

Once the EPA determines that circumstances warrant use of an enforceable commitment, the 

EPA considers three factors in determining whether to approve the use of an enforceable 

commitment to meet a CAA requirement: (a) does the commitment address a limited portion of 

the CAA-required program; (b) is the state capable of fulfilling its commitment; and (c) is the 

commitment for a reasonable and appropriate period of time.65

2. Control Strategy in the 2012 PM2.5 Plan 

For purposes of evaluating the 2012 PM2.5 Plan, we have divided the measures relied on to 

satisfy the applicable control requirements into two categories: baseline measures and control 

strategy measures.

As the term is used here, baseline measures are federal, State, and District rules and 

regulations adopted prior to January 2012 (i.e., prior to the development of 2012 PM2.5 Plan) that 

continue to achieve emissions reductions through the current attainment year of 2015 and 

beyond.66 The Plan describes many of these measures in Chapter 5, Section 5.1.1 and 5.1.2 and 

in Appendices C and D. Reductions from these measures are incorporated into the baseline 

 

64 E.g., American Lung Ass'n of N.J. v. Kean, 670 F. Supp. 1285 (D.N.J. 1987), aff'd, 871 F.2d 319 (3rd Cir. 1989); 

NRDC, Inc. v. N.Y. State Dept. of Env. Cons., 668 F. Supp. 848 (S.D.N.Y. 1987); Citizens for a Better Env't v. 

Deukmejian, 731 F. Supp. 1448, recon. granted in par, 746 F. Supp. 976 (N.D. Cal. 1990); Coalition for Clean Air v.

South Coast Air Quality Mgt. Dist., No. CV 97-6916-HLH, (C.D. Cal. Aug. 27, 1999).

65 The U.S. Court of Appeals for the Fifth Circuit upheld the EPA's interpretation of CAA section 110(a)(2)(A) and 

172(c)(6) and the Agency's use and application of the three factor test in approving enforceable commitments in the 

Houston-Galveston ozone SIP in BCCA Appeal Group et al. v. EPA et al., 355 F.3d 817 (5th Cir. 2003).

66 These measures are typically rules that have compliance dates that occur after the adoption date of a plan and 

mobile source measures that achieve reductions as older engines are replaced through attrition (e.g., through fleet 

turnover).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

57

inventory and, for the most part, not individually quantified. According to the Plan, these 

measures provide all the emissions reductions projected to occur between the base year of 2007 

and the current attainment year of 2015 and, based on the model-predicted level of emission 

reductions needed to meet the 2006 PM2.5 standard in the SJV in 2019, most of the direct PM2.5, 

NOx, SO2, and ammonia reductions needed to meet the PM2.5 standard. See Table F-1 in the TSD

and Appendices A and B in the TSD.

Control strategy measures are the new rules, rule revisions, commitments, and other 

measures that provide the additional increment of emissions reductions needed beyond the 

baseline measures to provide for attainment (when applicable), to demonstrate RFP, to meet the 

RACM/RACT requirement, or to provide for contingency measures.

For the Plan, the District identified and committed to adopt, submit, and implement 

amendments to four District prohibitory rules as well as to adopt and submit a rule to provide a 

process for quantifying emission reductions from the use of incentive funds (Rule 9610) (2012 

PM2.5 Plan, p. 5-21, Table 5-3 and SJV Governing Board Resolution 2012-12-19, p. 4). The 

District also committed to achieve an aggregate reduction of 1.9 tpd of direct PM2.5 by 2019 (id).

These commitments and their current status are shown in Table 3 below.67

Table 3. San Joaquin Valley Air Pollution Control District

2012 PM2.5 Plan Specific Rule Amendment Commitments

District 

Rule # 

Measure 

Number & 

Description

Amendment 

Date

Compliance 

Date

Emission 

Reductions

Status of the 

Amended Rule

4308

Boilers, Steam 

Generators, 

and Process 

Heaters 0.075 

2013 2015 TBD

Adopted 

November 14, 

2013; submitted 

May 13, 2014.

 

67 The current status of each commitment is presented for informational purposes only. We are not at this time 

proposing to make any finding regarding the District’s compliance with these commitments. 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

58

Table 3. San Joaquin Valley Air Pollution Control District

2012 PM2.5 Plan Specific Rule Amendment Commitments

District 

Rule # 

Measure 

Number & 

Description

Amendment 

Date

Compliance 

Date

Emission 

Reductions

Status of the 

Amended Rule

to <2 

MMBtu/hr

4692 Commercial 

Charbroiling 2016 2017 0.4 tpd PM2.5

Adoption 

scheduled for 

2016

4901

Wood Burning 

Fireplaces and 

Wood Burning 

Heaters

2016 2016/2017 1.5 tpd of 

PM2.5

Adopted 

September 18,

2014

4905

Natural GasFired, Fan 

Type 

Residential 

Central 

Furnaces 

2014 2015 TBD

Adoption 

scheduled for 

January 22, 2015

9610

SIP 

Creditability of 

Incentives

2013 2013 TBD

Adopted June 20, 

2013; proposed 

for approval May 

19, 2014 (79 FR 

28650)

Source: 2012 PM2.5 Plan, p. 5-21, Table 5-3. 

3. Evaluation and Proposed Actions

As discussed above, the Plan provides for the vast majority of the emissions reductions 

necessary for attainment to be achieved by baseline measures. These reductions come from a 

combination of District, State, and federal stationary and mobile source measures. Over the past 

two decades, the District has adopted or revised almost 40 prohibitory rules that limit emissions 

of NOx, SO2 and/or particulate matter from stationary and area sources in the SJV area (see 

Appendix B of the TSD). All but a few of these rule are currently SIP approved and as such their 

emissions reductions are fully creditable in attainment-related SIPs. California has also adopted 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

59

standards for many categories of on- and off-road vehicles and engines as well as standards for 

gasoline and diesel fuels (2012 PM2.5 Plan, Chapter 5).

The State’s mobile source measures fall into two categories: measures for which the State has 

obtained or has applied to obtain a waiver of federal pre-emption or authorization under CAA 

section 209 (“section 209 waiver measures” or “waiver measures”) and those for which the State 

is not required to obtain a waiver or authorization (“non-waiver measures” or “SIP measures”). 

We believe that credit for emissions reductions from implementation of California mobile source 

rules that are subject to CAA section 209 waivers or authorizations (i.e., “waiver measures”) is 

appropriate notwithstanding the fact that such rules are not approved as part of the California 

SIP. Historically, the EPA has granted credit for the waiver measures because of special 

Congressional recognition, in establishing the waiver process in the first place, of the pioneering 

California motor vehicle control program and because amendments to the CAA (in 1977) 

expanded the flexibility granted to California in order “to afford California the broadest possible 

discretion in selecting the best means to protect the health of its citizens and the public welfare”

(H.R. Rep. No. 294, 95th Congr., 1st Sess. 301-2 (1977)). In allowing California to take credit 

for the waiver measures notwithstanding the fact that the underlying rules are not part of the 

California SIP, the EPA treated the waiver measures similarly to the Federal motor vehicle 

control requirements, which the EPA has always allowed States to credit in their SIPs without 

submitting the program as a SIP revision.

Credit for Federal measures, including those that establish on-road and nonroad standards, 

notwithstanding their absence in the SIP, is justified by reference to CAA section 110(a)(2)(A), 

which establishes the following content requirements for SIPs: “* * * enforceable emission 

limitations and other control measures, means, or techniques (including economic incentives 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

60

such as fees, marketable permits, and auctions of emissions rights), * * *, as may be necessary or 

appropriate to meet the applicable requirements of this chapter.” (emphasis added). Federal 

measures are permanent, independently enforceable (by the EPA and citizens), and quantifiable 

without regard to whether they are approved into a SIP, and thus the EPA has never found such 

measures to be “necessary or appropriate” for inclusion in SIPs to meet the applicable 

requirements of the CAA. Section 209 of the CAA establishes a process under which the EPA

allows California's waiver measures to substitute for Federal measures, and like the Federal 

measures for which they substitute, the EPA has historically found, and continues to find, based 

on considerations of permanence, enforceability, and quantifiability, that such measures are not 

“necessary or appropriate” for California to include in its SIP to meet the applicable CAA 

requirements.

First, with respect to permanence, we note that, to maintain a waiver, CARB's on-road 

waiver measures can be relaxed only to a level of aggregate equivalence to the Federal Motor 

Vehicle Control Program (FMVCP). (CAA section 209(b)(1)). In this respect, the FMVCP acts 

as a partial backstop to California's on-road waiver measures (i.e., absent a waiver, the FMVCP 

would apply in California). Likewise, Federal nonroad vehicle and engine standards act as a 

partial backstop for corresponding California nonroad waiver measures. (CAA section 

209(e)(2)(A)). The constraints of the waiver process thus serve to limit the extent to which 

CARB can relax the waiver measures for which there are corresponding EPA standards, and 

thereby serve an anti-backsliding function similar in substance to those established for SIP 

revisions in CAA sections 110(l) and 193. Meanwhile, the growing convergence between 

California and EPA mobile source standards diminishes the difference in the emissions 

reductions reasonably attributed to the two programs and strengthens the role of the Federal 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

61

program in serving as an effective backstop to the State program. In other words, with the 

harmonization of EPA mobile source standards with the corresponding State standards, the 

Federal program is becoming essentially a full backstop to most parts of the California program.

Second, as to enforceability, we note that the waiver process itself bestows enforceability 

onto California to enforce the on-road or nonroad standards for which the EPA has issued the 

waiver or authorization. CARB has as long a history of enforcement of vehicle/engine emissions 

standards as the EPA, and CARB's enforcement program is equally as rigorous as the 

corresponding EPA program. The history and rigor of CARB's enforcement program lends 

assurance to California SIP revisions that rely on the emissions reductions from CARB's rules in 

the same manner as the EPA's mobile source enforcement program lends assurance to other 

states’ SIPs in their reliance on emissions reductions from the FMVCP. While it is true that 

citizens and the EPA are not authorized to enforce California waiver measures under the Clean 

Air Act (i.e., because they are not in the SIP), citizens and the EPA are authorized to enforce 

EPA standards in the event that vehicles operate in California without either California or EPA 

certification.

As to quantifiability, the EPA's historical practice has been to give SIP credit for motorvehicle-related waiver measures by allowing California to include motor vehicle emissions 

estimates made by using California's EMFAC (and its predecessors) motor vehicle emissions 

factor model in SIP inventories. The EPA verifies the emissions reductions from motor-vehiclerelated waiver measures through review and approval of EMFAC, which is updated from time to 

time by California to reflect updated methods and data, as well as newly-established emissions 

standards. (Emissions reductions from the EPA's motor vehicle standards are reflected in an 

analogous model known as MOVES.) The EMFAC model is based on the motor vehicle 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

62

emissions standards for which California has received waivers from the EPA but accounts for 

vehicle deterioration and many other factors. The motor vehicle emissions estimates themselves 

combine EMFAC results with vehicle activity estimates, among other considerations. See the 

1982 Bay Area Air Quality Plan, and the related EPA rulemakings approving the plan (see 48 FR 

5074, February 3, 1983, for the proposed rule and 48 FR 57130, December 28, 1983, for the final 

rule) as an example of how the waiver measures have been treated historically by the EPA in

California SIP actions. The 2012 PM2.5 Plan was developed using a version of the EMFAC 

model referred to as EMFAC2011, which the EPA has approved for use in SIP development in 

California (78 FR 14533, March 6, 2013). Thus, the emissions reductions that are from the 

California on-road "waiver measures" and that are estimated through use of EMFAC are as 

verifiable as are the emissions reductions relied upon by states other than California in 

developing their SIPs based on estimates of motor vehicle emissions made through the use of the 

MOVES model.

Moreover, the EPA's waiver (and authorization) review and approval process is analogous to 

the SIP approval process. First, CARB adopts its emissions standards following notice and 

comment procedures at the state level, and then submits the rules to the EPA as part of its waiver 

request. When the EPA receives new waiver or authorization requests from CARB, the EPA

publishes a notice of opportunity for public hearing and comment and then publishes a decision 

in the Federal Register following the public comment period. Once again, in substance, the 

process is similar to that for SIP approval and supports the argument that one hurdle (the 

waiver/authorization process) is all Congress intended for California standards, not two 

(waiver/authorization process plus SIP approval process). Second, just as SIP revisions are not 

effective until approved by the EPA, changes to CARB's rules (for which a waiver or 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

63

authorization has been granted) are not effective until the EPA grants a new waiver or 

authorization, unless the changes are "within the scope" of a prior waiver or authorization and no 

new waiver or authorization is needed. Third, both types of final actions by the EPA-- i.e., final 

actions on California requests for waivers or authorizations and final actions on state submittals 

of SIPs and SIP revisions--may be challenged under CAA section 307(b)(1) in the appropriate 

United States Court of Appeals.

For additional explanation of the EPA’s long-standing practice of allowing credit for 

California “waiver measures” notwithstanding the fact that the measures are not approved into 

the SIP, please see the EPA’s responses to comments challenging this practice in the following 

final rules: 77 FR 12652, at 12655-12658, March 1, 2012 (final action on San Joaquin Valley 

1997 8-Hour Ozone SIP); 77 FR 12674, at 12677-12682, March 1, 2012 (final action on South 

Coast 1997 8-Hour Ozone SIP); 76 FR 69896, at 69906-69910, November 9, 2011 (final action 

on San Joaquin Valley 1997 PM2.5 SIP); 76 FR 69928, at 69930-69932, November 9, 2011 (final 

action on South Coast 1997 PM2.5 SIP).

In addition to baseline measures, which according to the District will achieve the vast 

majority of the direct PM2.5, NOx, and SOx emission reductions needed to attain the 2006 PM2.5

standard in the SJV, the Plan also contains District commitments to adopt several amendments to 

its rules by specific dates and to achieve specified amounts of emissions reductions by 2019 

(2012 PM2.5 Plan, p. 5-21, Table 5-3 and SJV Governing Board Resolution 2012-12-19, p. 4; see 

also Table 2 above).

As discussed above, we generally consider three factors in determining whether to approve 

the use of an enforceable commitment to meet a CAA requirement. In this case, however, the 

2012 PM2.5 Plan does not rely on either the rule amendment commitments or the emission 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

64

reduction commitments in the impracticability demonstration, RACM demonstration, RFP 

demonstration, or quantitative milestones, or to meet any other CAA requirement; therefore, we 

do not need to apply this three factor test before proposing to approve the District’s 

commitments into the SIP. Approval of these commitments will strengthen the SIP and 

contribute to the SIP’s purpose of “eliminating or reducing the severity and number of violations 

of the [PM2.5 NAAQS] and achieving expeditious attainment of such standards.” (CAA section 

176(c)(1)(A)). For these reasons, the EPA proposes to approve the SJVAPCD Governing Board 

District’s commitments as given in p. 5-21, Table 5-3 of the 2012 PM2.5 Plan and on page 4 of 

SJV Governing Board Resolution 2012-12-19.

G. Demonstration that Attainment by the Moderate Area Attainment Date is Impracticable

1. Requirements for Attainment/Impracticability of Attainment Demonstrations

CAA section 189(a)(1)(B) requires that each Moderate area attainment plan include a 

demonstration that the plan provides for attainment by the latest applicable Moderate area 

deadline or, alternatively, that attainment by the latest applicable attainment date is

impracticable. A demonstration that the plan provides for attainment must be based on air quality 

modeling, and the EPA generally recommends that a demonstration of impracticability also be 

based on air quality modeling consistent with the EPA’s modeling guidance (General Preamble 

at 13538).

68 Id.

CAA section 188(c) states, in relevant part, that the Moderate area attainment date “shall be 

as expeditiously as practicable but no later than the end of the sixth calendar year after the area’s 

designation as nonattainment....” For the San Joaquin Valley, which was initially designated as 

nonattainment for the 2006 PM2.5 NAAQS effective December 14, 2009, the applicable 

 

68 For more information on the applicable air quality modeling requirements, please see section IV.B. above. 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

65

Moderate area attainment date under section 188(c) is as expeditiously as practicable, but no 

later than December 31, 2015.

In SIP submissions to demonstrate impracticability, the state should document that its 

required control strategy in the attainment plan represents the application of RACM/RACT to 

existing sources. The EPA believes it is reasonable to require adoption of all available control

measures that are technologically and economically feasible in areas that do not demonstrate

timely attainment. The impracticability demonstration will then be based on a showing that the 

area cannot attain by the applicable date, notwithstanding implementation of the required 

controls.

2. Impracticability Demonstration in the 2012 PM2.5 Plan

The 2012 PM2.5 Plan and Supplement include a demonstration, based on air quality modeling 

that even with the implementation of all reasonably available control measures for all appropriate 

sources, attainment by December 31, 2015 is not practicable. See 2012 PM2.5 Plan, section 9.1 

and Supplement, section 2.1. This demonstration is specific to Kern County (in particular the 

California Street-Bakersfield monitor) because the air quality modeling performed for the 2012 

PM2.5 Plan showed that this area would be the last to attain the 2006 PM2.5 standard. Id. The 

demonstration is summarized in Table 4 below. 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

66

Table 4. Impracticability of Attainment Demonstration, Kern County (tons per winter day)

Year 2015

Baseline NOx inventory 58.6

New control measures 0

NOx inventory after new controls 58.6

NOx emissions level needed for attainment 46.8

Shortfall in NOx emissions reductions needed for attainment 11.8

Baseline direct PM2.5 inventory 11.5

New control measures 0

Direct PM2.5 inventory after new controls 11.5

Direct PM2.5 level needed for attainment 11.1

Shortfall in direct PM2.5 emissions reductions needed for 

attainment

0.4

Baseline SO2 inventory 1.8

New control measures 0

SO2 inventory after new controls 1.8

SO2 emissions level needed for PM2.5 attainment 1.8

Shortfall in SO2 emission reductions needed for attainment 0

Source: 2014 Supplement, p. 6.

3. Evaluation and Proposed Action

The impracticability demonstration in the 2012 PM2.5 Plan is based on air quality modeling

which is generally consistent with applicable EPA guidance. We find the modeling adequate to 

support the impracticability demonstration in the Plan. See section VI.B.

We have also evaluated the RACM/RACT demonstration and find that it provides for the 

expeditious implementation of all RACM/RACT that may feasibly be implemented at this time, 

consistent with the requirements of CAA sections 172(c)(1) and 189(a)(1)(C) for the 2006 PM2.5

NAAQS in the SJV. See section IV.D. 

Finally, we have evaluated the demonstration in the 2012 PM2.5 Plan that the implementation 

of the State/District’s SIP control strategy, including RACM/RACT measures, is insufficient to 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

67

bring the San Joaquin Valley into attainment by December 31, 2015 and agree that attainment by 

that date is thus impracticable.

In addition to the information in the 2012 PM2.5 Plan and Supplement, we have reviewed 

recent PM2.5 monitoring data from the San Joaquin Valley. These data show that 24-hour PM2.5

levels in the SJV, with a current design value (2011-2013) of 65 μg/m3, continue to be well 

above the 35 μg/m3level of the 2006 PM2.5 standard, and the recent trends in the Valley’s 24-

hour PM2.5 levels are not consistent with a projection of attainment by the end of 2015.69 

Based on this evaluation, we propose to approve the State’s demonstration in the 2012 PM2.5

Plan and Supplement that attainment of the 2006 PM2.5 NAAQS by the Moderate area attainment 

date in the SJV is impracticable, consistent with the requirements of CAA section 

189(a)(1)(B)(ii). Based on this proposal, we also propose to reclassify the SJV as Serious 

nonattainment, which would trigger requirements for the State to submit a Serious area plan 

consistent with the requirements of subparts 1 and 4 of part D, title I of the Act (see Section V).

H. 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 3 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 

 

69 See Memorandum dated December 15, 2014 from Elfego Felix and Scott Bohning, U.S. EPA, Region 9 Air 

Quality Analysis Office, to San Joaquin Valley Reclassification Docket, Subject: Practicability of SJV 2015 

attainment of the 2006 24-hour PM NAAQS (“Felix-Bohning Memo”) and U.S. EPA, 2013 Design Value Reports, 

PM2.5 Detailed Information Updated 8/24/14, available at http://www.epa.gov/airtrends/values.html

(“PM25_DesignValues_20112013_FINAL_08_28_14).”
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

68

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.

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 

(Addendum at 42015). 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. Id. 

The EPA’s guidance in the Addendum recommends that requiring linear progress is 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 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

69

compliance schedule’ which is likely to periodically yield significant emission reductions of 

direct PM2.5 or a PM2.5 precursor” (Addendum at 42015).

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 (Addendum at 42016). 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. We believe that it 

is appropriate to require early implementation of the most cost-effective control measures while 

phasing in the more expensive control measures (Id.). 

Section 189(c) provides that the quantitative milestones submitted by a state for an area also 

must be consistent with RFP for the area. 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 3 years, when a state demonstrates compliance with the quantitative milestone 

requirement, it will demonstrate that RFP has been achieved during each of the relevant 3 years. 

Quantitative milestones should consist of elements that allow progress to be quantified or 

measured objectively. Specifically, states should identify and submit quantitative milestones 

providing for the amount of emission reductions adequate to achieve the NAAQS by the 

applicable attainment date (Addendum at 42016). 

The CAA does not specify the starting point for counting the 3-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 3-year period be the due date for the 

Moderate area plan submittal (General Preamble at 13539, Addendum at 42016). In keeping with 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

70

this historical approach, the 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 2006 PM2.5 standard in the 

SJV. This date is the due date for the state’s submittal of attainment-related SIPs necessary to 

satisfy the subpart 4 Moderate area requirements applicable to the SJV area.70 Accordingly, the 

first quantitative milestone date for the SJV area would be December 31, 2017 (3 years after 

December 31, 2014). Following reclassification of the SJV area as Serious for the 2006 PM2.5

standard, later milestones would be addressed by the Serious area plan (Addendum at 42016).

2. RFP Demonstration and Quantitative Milestones in the 2012 PM2.5 Plan

The RFP demonstration is in Chapter 9, section 9.3 (pp. 9-4 to 9-7) of the 2012 PM2.5 Plan. 

The District included this same demonstration and provided a brief discussion of quantitative 

milestones in section 4 (p. 14) of the Supplement. The demonstration addresses direct PM2.5, 

NOx, and SO2 and uses the 2007 winter daily average inventory as the base year inventory and 

the 2019 winter daily average baseline inventory as the attainment year inventory. The 2012 

PM2.5 Plan does not explicitly provide an RFP demonstration for ammonia but does include a 

base year ammonia inventory as well as 2014, 2017, and 2019 ammonia baseline inventories, 

which account for reductions from existing ammonia control measures. (2012 PM2.5 Plan at 

Appendix B).

The Plan shows that emissions of direct PM2.5, NOx and SOx will decline from the 2007 base 

year through 2015 and states that emissions will remain below the levels needed to show 

“generally linear progress” from 2007 to 2019 – the year that the Plan projects to be the earliest 

 

70 Subpart 4 requires states to submit attainment plans within 18 months after nonattainment designations (CAA 

189(a)(2)). Due to unusual circumstances, however, the EPA has by rule created a later attainment plan submission 

date for the 2006 PM2.5 NAAQS in order to provide states and the EPA an opportunity to address the requirements 

for attainment plans consistent with a court decision. See 79 FR 31566 (June 2, 2014).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

71

practicable attainment date (2012 PM2.5 Plan, section 9.3). Direct PM2.5, NOx and SO2 are 

emitted by a large number and range of sources in the SJV and the emission reductions needed 

for these pollutants are inventory wide (2012 PM2.5 Plan, Appendix B). The District followed the 

procedures in the 2007 PM2.5 Implementation Rule (40 CFR § 51.1009(f)) to calculate its RFP 

targets for 2014 and 2017 in both the 2012 PM2.5 Plan71 and the Supplement. (2012 PM2.5 Plan, 

pp. 9-5 to 9-7 and Supplement at 14). It then showed that projected emission levels based on its 

adopted control strategy would be below those targets in both milestone years. Id. With respect 

to quantitative milestones, the Supplement states that the Plan “identifies target emissions levels 

for generally linear progress that can serve as the quantitative milestones for subpart 4” and that 

the adopted control strategy in the Plan meets these quantitative milestones. Supplement at 14 

(citing 2012 PM2.5 Plan at Table 9-4).

3. Evaluation and Proposed Actions

We are deferring action on the quantitative milestones described on pg. 14 of the Supplement

but we are evaluating the Plan with respect to the RFP requirement. Because the District’s 

methodology for calculating “RFP target emission levels” and evaluating “generally linear 

progress” is premised on a 2019 attainment date, these evaluations are not consistent with the 

requirements of the Act.72 The Plan demonstrates, however, that all RACM/RACT are being 

implemented as expeditiously as practicable and identifies projected emission levels for 2014 

and 2017 that reflect full implementation of the State’s and District’s RACM/RACT control 

strategy for the area. See 2012 PM2.5 Plan, section 9.3 and Appendix B; see also discussion in 

 

71 The 2012 PM2.5 Plan was developed and adopted by the District in accordance with the methodology for 

calculating RFP targets in the 2007 PM2.5 Implementation Rule, prior to the D.C. Circuit’s decision in NRDC

remanding this rule. 

72 Under subpart 4, the latest permissible attainment date for a Moderate PM2.5 nonattainment area is the end of the 

sixth calendar year after the area’s designation as nonattainment. CAA 188(c)(1). Because the SJV area was 

designated nonattainment for the 2006 PM2.5 NAAQS effective December 2009, the area is currently subject to a 

Moderate area attainment date no later than December 31, 2015.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

72

Section II.D (“Reasonably Available Control Measures / Reasonably Available Control 

Technology”). In an area that cannot practicably attain the PM2.5 standard by the applicable 

Moderate area attainment date, we believe it is reasonable to find that full implementation of a 

control strategy that satisfies the Moderate area control requirements (i.e., RACM/RACT at a

minimum) represents reasonable further progress toward attainment. We propose, therefore, to 

approve the RFP demonstration for direct PM2.5, NOx and SO2 as meeting the requirements of 

CAA section 172(c)(2). 

The 2012 PM2.5 Plan also shows a substantial reduction in total ammonia emissions in the 

period 2007 to 2012 with emissions increasing each following year but still remaining below 

2007 base year levels in 2015 and 2019. See Appendix B, Table B-5. Unlike the wide range of 

sources emitting PM2.5, NOx and SO2 in the Valley, emissions of ammonia are almost entirely 

from three source categories: CAF, fertilizer application, and composting, with more than twothirds of all emissions coming from CAF.73 Collectively, these three categories emit 96 percent 

of all ammonia emissions in the 2007 base year inventory.

Reductions in ammonia emissions from CAF between 2007 and 2012 resulted from the 

implementation of District Rule 4570 “Confined Animal Operations,” which required 

implementation of control measures to reduce ammonia in 2008 and required full compliance by

affected sources by mid-2012. Although emissions in this category increase after 2012 due to 

continuing growth in the Valley’s dairy industry, overall emissions in 2015 and 2019 remain 

below the 2007 base year level. The implementation of the District’s Rule 4655 “Organic 

Material Composting Operations” (adopted August 18, 2011) beginning in 2012 most likely 

 

73 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. 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

73

resulted in some ammonia reductions (Supplement, p. A-27), but these reductions are not 

included in the base year or baseline inventories. As discussed in the Supplement (p. A-25), 

ammonia emissions from manure fertilizer application by dairies may be reduced as a co-benefit 

from the Central Valley Regional Water Quality Control Board’s requirements for reducing 

nitrate in ground water adopted in 2007. However, because these reductions are not quantified 

and the control requirements are not in the SIP, no reductions from these controls are included in 

the inventories at this time. 

As discussed above, generally linear reduction in emissions on a yearly basis may not be 

necessary for RFP where there are a limited number of sources of a precursor and where the 

emission control systems utilized will result in swift emission reductions. Both of these 

considerations are relevant for ammonia emissions in the San Joaquin Valley. In such cases, the 

EPA believes that RFP can be shown by adherence to an ambitious compliance schedule

(Addendum at 42015). In this case all ammonia reductions included in the 2012 PM2.5 Plan were 

achieved through the implementation of controls before the Plan was adopted. We believe that 

this represents an ambitious compliance schedule. Additionally, despite the growth in total 

ammonia emissions in the Valley after 2012, the District’s implementation of its existing 

RACM/RACT control strategy for ammonia emissions is projected to result in total ammonia 

emissions that are lower in the Moderate area attainment year of 2015 and in 2019 than in the 

base year of 2007 (Table 5 below). We propose, therefore, to conclude that the 2012 PM2.5 Plan 

provides for RFP for ammonia as required by CAA section 172(c)(2).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

74

Table 5. Ammonia Emissions by Year (winter daily average in tons)

2007 2012 2014 2015 2017 2019

A Farming Operations (CAF) 264.5 225.4 234.6 239.2 248.4 257.6

B Pesticide/Fertilizers 68.4 66.9 66.3 66.1 65.5 64.9

C

Other (Waste Disposal) 

(Composting) 17.9 19.3 20.1 20.5 21.3 22.2

D All other sources 16.5 15.0 15.0 14.9 15.2 15.4

E Total ammonia emissions 367.3 326.6 336.0 340.7 350.4 360.1

Source: 2012 PM2.5 Plan, Appendix B, Table B-5.

We are proposing to determine that VOCs do not contribute significantly to ambient PM2.5

levels that exceed the 2006 PM2.5 standard in the SJV and that a VOC control evaluation 

therefore is not necessary for RFP or quantitative milestones for purposes of the 2006 PM2.5

standard in the SJV (see section II.C. of the TSD). CAA section 171(1) defines RFP as “such 

annual incremental reductions in emissions of the relevant air pollutant ...that may reasonably be 

required by the Administrator for the purpose of ensuring attainment of the applicable [NAAQS] 

by the applicable date.” Based on our proposal to determine that VOCs do not contribute 

significantly to ambient PM2.5 levels that exceed the standard, we propose to conclude that no 

RFP demonstration or quantitative milestones are necessary for purposes of the 2006 PM2.5

standard in the SJV. 

In evaluating RFP, we are relying in part on the Plan’s analysis of both adopted control

measures and additional control measures for wood burning and charbroiling to be adopted in 

future years, which the Plan indicates will collectively bring the SJV into attainment of the 2006 

PM2.5 standard by the end of 2019. We are not, however, proposing to approve this 

demonstration of attainment by 2019 for any purpose at this time. Following reclassification of 

the SJV area to Serious nonattainment for the 2006 PM2.5 standard, the SJV area will be subject 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

75

to Serious Area planning requirements under subpart 4 and will need to reevaluate and 

strengthen its SIP control strategy as necessary to meet the Serious area requirement for best 

available control measures (BACM) and Best Available Control Technology (BACT), among 

other requirements. The State will also need to demonstrate attainment as expeditiously as 

practicable, but no later than December 31, 2019, and provide a revised RFP demonstration, both 

taking into consideration the implementation of the Serious Area control strategy. Today, we are 

proposing to approve most of the 2012 PM2.5 Plan and Supplement for the limited purpose of 

satisfying the statutory control requirements that apply to Moderate areas demonstrating that

attainment by the Moderate Area attainment date under subpart 4 is impracticable (see Section 

II.D. of the TSD). 

I. Contingency Measures

1. Requirements for Contingency Measures

Under CAA section 172(c)(9), PM2.5 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. Where the SIP includes a demonstration that attainment by the applicable 

attainment date is impracticable, the state need only submit contingency measures to be 

implemented if an area fails to meet RFP.

74

 

74 The EPA does not interpret the requirement for failure-to-attain contingency measures to apply to Moderate PM2.5

nonattainment areas that cannot practicably attain the NAAQS by the statutory attainment date. Rather, the EPA 

believes it is appropriate for the state to identify and adopt attainment contingency measures as part of the Serious 

area attainment plan that it will develop once the EPA reclassifies the area (Addendum at 42015).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

76

The purpose of contingency measures is to continue progress in reducing emissions while the 

SIP is being revised to meet the missed RFP milestone or correct continuing nonattainment.

The principle requirements for contingency measures are:

 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 

standard by its attainment date.

 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 the EPA notifies 

the state of a failure.

 The contingency measures should consist of other control measures for the area that are 

not relied on to demonstrate attainment or 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.

(General Preamble at 13543 and Addendum at 42014).

Contingency measures can include Federal, state and local measures already scheduled for 

implementation or already implemented. The CAA requires contingency measures that provide 

for additional emissions reductions that are not relied on to demonstrate RFP or attainment and 

thus not included in these demonstrations. In other words, contingency measures are intended to 

achieve reductions over and beyond those relied on in the RFP and attainment demonstrations. 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

77

Nothing in the CAA precludes a state from implementing such measures before they are 

triggered. EPA has approved numerous SIPs under this interpretation. 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).

2. Contingency Measures in the 2012 PM2.5 Plan

Contingency measures for failure to meet RFP milestones are described in Section 9-4 of the 

Plan. The Supplement also discusses the RFP contingency measures in section 5.

3. Evaluation and Proposed Action

We are deferring action on the RFP contingency measures in the 2012 PM2.5 Plan and 

Supplement. We note that once SJV is reclassified to Serious, the State will be obligated to 

demonstrate that its SIP provides for the implementation of BACM and BACT and for 

attainment as expeditiously as practicable, and no later than 2019. As part of this demonstration, 

the State will need to revise its RFP demonstration to establish new RFP targets, quantitative 

milestones, and RFP contingency measures for the 2006 PM2.5 NAAQS. 

Because we are proposing to approve the State’s demonstration that attainment by the 

applicable Moderate area attainment date of December 31, 2015 is impracticable in the SJV and 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

78

to reclassify the area to Serious, contingency measures for failure to attain are not required as 

part of this Moderate area plan. Upon reclassification of the SJV area as a Serious area, 

California will be required to adopt failure-to-attain contingency measures as part of the Serious 

area attainment plan for the 2006 PM2.5 NAAQS.

J. Interpollutant Trading Ratios for Nonattainment New Source Review Permits

The CAA’s Nonattainment New Source Review (NNSR) permitting provisions require that 

emissions from new or modified major stationary sources proposing to construct or modify in a 

nonattainment area be “offset” by reductions from the same or other sources in the area (CAA 

section 173(c)). This “offset” requirement ensures that progress toward attaining the NAAQS is 

maintained while still allowing for the construction and modification of major stationary sources. 

Generally, the pollutant emitted at the new or modified source must be offset by reductions of 

the same pollutant. Under certain circumstances, however, the EPA may allow for

“interpollutant” offsets – i.e., increased emissions of one pollutant (or a precursor to that 

pollutant) may be offset by reductions in a different precursor to the pollutant, or emissions of a 

certain precursor may be offset by reductions in the pollutant to which it is a precursor.

Where a state intends to provide for such interpollutant trading, the state must provide a 

technical demonstration that shows the net air quality benefits of the interpollutant trade in the 

PM2.5 nonattainment area, to ensure the trade does not jeopardize the attainment demonstration 

or progress toward attainment of the NAAQS. We refer to the rate of emission reduction in tons 

per day (tpd) that would offset the ambient effect of a 1 tpd increase in new source emissions as

an “interpollutant trading (IPT) ratio” or an “interpollutant equivalency ratio”. In a July 2011

policy memorandum (“IPT memo”), EPA stated that “any ratio involving PM2.5 precursors 

submitted to the EPA for approval for use in a state's interpollutant offset program for PM2.5
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

79

nonattainment areas must be accompanied by a technical demonstration that shows the net air 

quality benefits of such ratio for the PM2.5 nonattainment area in which it will be applied.”75 The 

IPT memo provides general guidance on developing interpollutant offset ratios, which includes 

sensitivity simulations with a photochemical model when PM2.5 precursors are involved. In 

rough terms, the memorandum describes the process for calculating a ratio as taking the modeled 

impact in micrograms per cubic meter (μg/m3) per tpd of the pollutant whose emissions are to be 

offset, and dividing by the μg/m3impact per tpd of the offsetting pollutant, i.e. the ratio of the 

sensitivities of ambient PM2.5 levels to emission changes in the pollutants.

76

The 2012 PM2.5 Plan includes proposed interpollutant trading ratios for use in the District’s 

NSR program. (Appendix H, p. H-3). The proposed ratios are 5.3 tpd of NOx emission reductions 

to offset 1 tpd of direct PM2.5 emission increase and 4.1 tpd of SOx emission reductions to offset 

1 tpd of direct PM2.5 emission increase. Id. Attachment 1 to Appendix H includes a description of 

the approach used for determining these ratios. The 2012 PM2.5 Plan refers to “EPA’s preferred 

method” for estimating ratios (pp. H-4 and H-88). As discussed above, however, the EPA has 

provided only general guidance and has not identified a preferred method. The method described 

in the Plan does use the general concept in the EPA’s IPT memo for computing a ratio of 

modeled sensitivities, but it contains internal inconsistencies and an insufficient rationale for the 

specific approach used to develop the ratios.

 

75 Memorandum, dated July 21, 2011, Gina McCarthy, Assistant Administrator, to Regional Air Division Directors, 

Regions 1-10, Subject: Revised Policy to Address Reconsideration of Interpollutant Trading Provisions for Fine 

Particles (PM2.5) (“IPT memo”).

76 If 1 tpd of pollutant A is to be offset by R tpd of pollutant B, and the sensitivity of PM2.5 to emissions in μg/m3 per 

tpd are respectively SA and SB, then the pollutant and its offset have an equal ambient PM2.5 effect in μg/m3 when 

SA*1= SB*R so R = SA/SB.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

80

An internal inconsistency of the approach used is that dividing the pollutant sensitivities 

provided in the sensitivity table gives ratios that do not match those provided in the trading ratio 

table (Appendix H, Tables 1 and 2, p. H-87). For example, for Fresno – 1st Street site, the 

sensitivities given are 0.14 μg/m3per tpd of direct PM2.5, and 0.03 for NOx; the ratio of these is 

4.7, but the corresponding trading ratio given is 4.0. Overall the differences in ratios range from 

+17 percent to -17 percent. These discrepancies may be a result of rounding within the sensitivity 

table, but there is not enough documentation to make this determination. Another inconsistency 

is that the interpollutant ratios provided in Appendix H do not match those provided in the 

WOEA (Staff Report Appendix B). For example, the WOEA sensitivities for BakersfieldCalifornia site imply that the NOx:PM2.5 and SOx:PM2.5 ratios are both 4.25,77 but the 

corresponding Appendix H ratios are given as 7.0 and 5.2. This discrepancy may be due to 

different modeling runs having been used to establish the ratios, but this is not explained.

The specifics of the Plan’s approach pose several difficulties. The Plan states that the 

sensitivity simulations used 50 percent reductions in emissions from “NSR source categories” (p. 

H-86). The latter is not defined. If “NSR source categories” are major stationary sources, then a 

50 percent reduction in the overall category would be far larger than any likely emission increase 

or offset. It is not clear that the response of the model to this large a change is representative of 

the ambient effects that would occur from an actual interpollutant trade or for the aggregate of 

trades expected to occur. The Plan states that a 50 percent reduction in annual average emissions 

was used, but it is not clear why this is appropriate for a NAAQS based on a 24-hour average.

The Plan provides no rationale for why a 50 percent reduction is appropriate to use for assessing 

 

77 For example, NOx:PM2.5 ratio = PM2.5 sensitivity / NOx sensitivity = 0.34/0.08 = 4.25 (Table 7, CARB Staff 

Report App. B., p.65).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

81

interpollutant ratios, including consideration of the robustness of the ratios under alternative 

reduction percentages. 

Another issue is that in general, the ambient effect of a trade will depend on the location of 

both the new source and the offset, since transport and atmospheric chemistry depend on 

location. The Plan implicitly recognizes this by providing ratios for multiple monitor locations,

ranging from 3.4 to 8.1. However, the Plan then averages the ratios together, which would seem 

to guarantee that the final ratio does not reflect any actual trade or impacts at any particular 

location. A scheme in which the ratio varied by general geographic zone of source and of offset 

would better address the effect of actual trades. Alternatively, the use of the maximum of the 

available ratios would have provided a conservative analysis. The Plan’s approach examined 

only design values and only at monitor locations, employing the same general procedure used for 

the attainment demonstration, i.e., the application of RRFs to monitored concentrations. It is not 

clear why this approach is appropriate for deriving interpollutant trading ratios for NSR. Trades 

will affect all concentrations, not just the 98th percentile and not just their three-year average as 

used in design value calculations. They will also affect all locations, not just those with monitors. 

The procedure used does not employ information about concentrations away from monitors that 

are available from the modeling; these concentrations show the outcome of a trade at 

unmonitored locations, but are not reflected in the procedure. 

A more general concern with the Plan procedure is that it does not provide an overall 

rationale for the methodology grounded in the statutory purpose of NSR offsets. The CAA 

requires that emissions from new or modified major stationary sources be sufficiently offset “so 

as to represent. . . reasonable further progress” toward attainment of the NAAQS (CAA 

173(a)(1)(A)), and the EPA’s implementing regulations require that emission offsets provide a 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

82

“net air quality benefit in the affected area” (40 CFR part 51, Appendix S, sec. IV. A.). The Plan 

does not explain how this requirement is satisfied when interpollutant trading is used. As 

mentioned above, the justification for an interpollutant ratio requires a technical demonstration 

that the new source emission increase and the offset are equivalent in their ambient effect. 

However, the precise sense in which changes in precursor emissions must be “equivalent” has 

not been defined; equivalency could be defined in terms of the maximum concentration from the 

model, the average over time and space of modeled concentrations above the NAAQS, or some 

other metric. The criteria for assessing equivalency should be provided with a rationale grounded 

in the underlying goals of NSR offsetting.

Given these inadequacies in the technical demonstration and related documentation for the 

PM2.5 NSR interpollutant trading ratios provided in Appendix H of the 2012 PM2.5 Plan, we are 

proposing to disapprove these interpollutant trading ratios for NSR purposes.

K. Motor Vehicle Emission Budgets

1. Requirements for Motor Vehicle Emissions Budgets

CAA section 176(c) requires Federal actions in nonattainment and maintenance areas to 

conform to the SIP’s goals of eliminating or reducing the severity and number of violations of 

the NAAQS and achieving 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 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

83

(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 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 (40 CFR § 93.118(e)(4)(v)).

PM2.5 plans should identify budgets for direct PM2.5 and all 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 tailpipe, 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. (40 CFR § 93.102(b) and § 93.122(f) and the conformity rule preamble at 69 FR 

40004, 40031–40036 (July 1, 2004)). 

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. 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

84

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 

submitted SIP to apply for conformity purposes before the SIP 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 submittal must meet the conformity adequacy requirements of 

40 CFR § 93.118(e)(4). The criteria for determining adequacy of submitted motor vehicle 

emissions budgets are provided at 40 CFR § 93.118(e)(4) and (5). The transportation conformity 

rule, however, does allow submitted motor vehicle emissions budgets that have been found 

adequate to replace approved budgets if the EPA has limited the duration of its approval to last 

only until it finds replacement budgets adequate (40 CFR § 93.118(e)(1)).

2. Motor Vehicle Emissions Budgets in the 2012 PM2.5 Plan

The 2012 PM2.5 Plan includes budgets for direct PM2.5 and NOx for the RFP years of 2014 

and 2017 and the projected attainment year of 2019. (2012 PM2.5 Plan, Appendix C, section 

C.11). The SJV has eight separate county-based MPOs; therefore, separate budgets are provided 

for each MPO as well as a total for the nonattainment area as a whole. The budgets reflect winter 

daily average emissions and are calculated using EMFAC2011, the currently approved emission 

model for California (78 FR 14533 (March 6, 2013)).78 Winter annual day emissions are used in 

 

78 After EMFAC2011 was released in 2011, new information on statewide diesel fuel usage and economic forecasts 

became available to the State. For the 2012 PM2.5 Plan, CARB adjusted EMFAC2011 emissions estimates for 

heavy-duty trucks to reflect this new information (p. B-26). The EPA allowed the use of these adjustment factors in 

transportation conformity determinations in the SJV. See footnote 14 of this notice.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

85

the Plan and the budgets because SJV’s exceedances of the 24-hour PM2.5 standard occur almost 

exclusively during the winter months (2012 PM2.5 Plan, p. 3-4 and Appendix G, p. 7).

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 Valley (Appendix C, 

section C.11.2.). The Plan states it does not include budgets for SO2 because on-road mobile 

exhaust estimates of SOx are less than 1 ton per day Valley-wide in 2014 and 2017, which equates to 

less than 10 percent of the total SOx emissions inventory for those years (id.). Additionally, the Plan

states that it does not include budgets for VOC because VOC emissions do not contribute 

significantly to the formation of secondary PM2.5 in the SJV (id.). The Plan does not specifically 

address ammonia emissions for MVEB purposes but shows that ammonia emissions from onroad mobile sources contribute just over 1 percent of the total ammonia inventory in 2014 and 

2017 (see Plan at Appendix B, Table B-5). 

The truck activity estimates in EMFAC2011 used to develop the budgets in the 2012 PM2.5

Plan are consistent with those used by CARB in its 2010 revisions to the In-Use Truck and Bus 

Rule. Since the 2010 updates, new economic data (e.g., statewide diesel fuel usage, truck sales) 

has become available which suggests that truck emissions will be lower in future years in the San 

Joaquin Valley than currently estimated in EMFAC2011. In order to account for this reduction in 

emissions from trucks in the budgets, results from EMFAC2011 are scaled by year-specific 

factors (SJV PM2.5 Plan, Appendix C, section C.11.3 and Table C-1). The MPOs will also use 

these scaling factors in their conformity determinations.79 Reductions from certain State and 

 

79 On January 14, 2014, we approved the use of these scaling factors by the SJV MPOs in the regional emissions 

analyses in their transportation conformity determinations. See letter dated January 14, 2014, Matthew Lakin, Chief, 

Air Planning Office, EPA-Region 9 to John Taylor, Branch Chief, Transportation Planning Branch, CARB; Subject: 

Use of San Joaquin Valley Heavy Duty Diesel Vehicle Recession Adjustment Methodology.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

86

local control measures are not included in the on-road emission inventories generated from 

EMFAC2011 and must be subtracted from EMFAC2011 inventories used as the basis for the 

motor vehicle emissions budgets and the attainment demonstration.

On October 7, 2014, we received a letter from CARB stating that it intends to revise the 

previously-submitted 2014 and 2017 budgets to remove reductions resulting from 

implementation of the Carl Moyer and Proposition IB incentive grant programs but intends to 

make no other revisions to the budgets. The letter provided the proposed revised budgets. (Table 

6 below). These changes make the budgets consistent with the attainment demonstration. The 

letter also stated that CARB would be taking the revised budgets to its Board in November 2014

for approval and an additional letter from CARB requested in the interim that the EPA consider 

these budgets under the Agency’s parallel processing procedures for SIP submittals.80,81

Table 6. 2006 PM2.5 Standard MVEB for the San Joaquin Valley

(winter daily average in tons)

County

2014 2017

PM2.5 NOx PM2.5 NOx

Fresno 1.0 31.6 0.9 25.2

Kern (SJV) 1.2 43.2 1.0 34.4

Kings 0.2 8.8 0.2 7.2

Madera 0.3 8.7 0.2 7.0

Merced 0.5 17.2 0.4 13.7

San Joaquin 0.7 20.0 0.6 15.9

Stanislaus 0.5 15.1 0.5 12.0

Tulare 0.5 14.3 0.4 10.7

Total* 4.9 159.0 4.2 126.0

 

80 Letter from Richard Corey, Executive Officer, CARB, to Jared Blumenfeld, Regional Administrator, Region 9, 

dated October 7, 2014. 

81 Letter from Richard Corey, Executive Officer, CARB, to Jared Blumenfeld, Regional Administrator, Region 9, 

dated November 6, 2014, requesting parallel processing of the motor vehicle emissions budgets in the 2012 PM2.5 

Plan. 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

87

Source: Letter, Richard Corey, Executive Officer, CARB, to Jared Blumenfeld, Regional Administrator, 

Region 9, dated October 7, 2014, Attachment, Table C-4.

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

Attachment, Letter, Richard Corey, Executive Officer, CARB, to Jared Blumenfeld, Regional 

Administrator, Region 9, dated October 7, 2014, with Attachment, revised Table C-4, “Transportation 

Conformity Budgets” to 2012 PM2.5 Plan.

The 2012 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:PM2.5 ratio of 8:1. (Appendix C, 

section C.11.3 and Table C-2). 

3. Evaluation and Proposed Actions 

We have evaluated the revised budgets against our adequacy criteria in 40 CFR 93.118(e)(4) 

as part of our review of the budgets’ approvability (see section II.I (Table I-3) in the TSD for this 

proposal) and expect to have completed the adequacy review of these budgets before or 

concurrent with our final action on the 2012 PM2.5 Plan.

82 We posted the budgets on EPA’s 

adequacy review web page at http://www.epa.gov/otaq/stateresources/transconf/currsips.htm

from October 23, 2014 to November 24, 2014 and did not receive any comments on them.

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. 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 transportation-related emissions of VOC, SO2, and ammonia emissions are

 

82 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).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

88

not significant contributors to the PM2.5 nonattainment problem in the SJV area and, accordingly, 

that MVEBs for these pollutants are not necessary.

For the reasons discussed in section IV.G., above, we are proposing to approve the State’s 

demonstration that it is impracticable to attain the 2006 PM2.5 standard in the San Joaquin Valley 

by the applicable Moderate area attainment date of December 31, 2015 and proposing to 

reclassify the area as Serious. Because the 2012 PM2.5 Plan does not demonstrate attainment, we 

do not address in this proposal any budgets for the attainment year of 2015 or 2019. 

For reasons discussed in section IV.H. above, we are proposing to approve the RFP 

demonstration for 2014 and 2017 in the 2012 PM2.5 Plan. The budgets, as given in Table 6

above, are consistent with the demonstration, are clearly identified and precisely quantified, and 

meet all other applicable statutory and regulatory requirements including meeting the adequacy 

criteria in 93.118(e)(4). For these reasons, the EPA proposes to approve the budgets listed in 

Table 6 above. We provide a more detailed discussion in Section II.H of the TSD, which can be 

found in the docket for today’s action.

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. (Letter, 

James N. Goldstene, Executive Officer, California Air Resources Board, to Jared Blumenfeld, 

Regional Administrator, EPA Region 9, March 4, 2013). The transportation conformity rule 

allows us to limit the approval of budgets. (40 CFR § 93.118(e)(1)). However, we can consider a 

state’s request to limit an approval of its MVEB only if the request includes the following 

elements:

o An acknowledgement and explanation as to why the budgets under consideration have 

become outdated or deficient; 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

89

o A commitment to update the budgets as part of a comprehensive SIP update; and 

o 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.

(67 FR 69141 (November 15, 2002) (limiting our prior approval of MVEB in certain California 

SIPs)).

Because CARB’s request does not include all of these elements, we cannot address it at this 

time. Once CARB has adequately addressed them, we intend to review the information and take 

appropriate action. If we propose to limit the duration of our approval of the MVEB in the 2012 

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 standards (76 FR 69896, 69923 (November 9, 2011)). These budgets will continue to 

apply for the 2006 24-hour standard until we finalize our approval of the budgets in the 2012 

PM2.5 Plan or find these budgets adequate. The budgets approved in 2011, however, will 

continue to apply in the SJV for determining transportation conformity for the 1997 PM2.5 annual 

and 24-hour standards.

As noted above, the State included a trading mechanism to be used in transportation 

conformity analyses that would use the proposed budgets in the 2012 Plan83 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:PM2.5 ratio of 8:1. 

To ensure that the trading mechanism does not impact the ability to meet the NOx budget, the 

 

83 The budgets and the trading program approved in 2011 will continue to apply in the SJV for determining 

transportation conformity for the 1997 PM2.5 annual standard.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

90

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 

agency 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 air quality modeling used to develop the 8:1 NOx:PM2.5 ratio and,

while we are not proposing to take any action on it, we find that it is a reasonable method to use 

to develop ratios for transportation conformity purposes. We note that the ratio the State is 

proposing to use for transportation conformity purposes is derived from air quality modeling that 

evaluated the effect of reductions in local Kern County NOx and PM2.5 levels on ambient 

concentrations at the California Avenue-Bakersfield site (2012 PM2.5 Plan, Appendix G, p. 68). 

The air quality modeling that the State performed to evaluate the effectiveness of regional 

(nonattainment wide) NOx and PM2.5 reductions on ambient concentrations showed NOx:PM2.5

ratios that range from a high of 4.7 at the Stockton monitor to a low of 2.8 at the Corcoran 

monitor. See 2012 PM2.5 Plan, Appendix G, p. 65. Because the 8:1 trading ratio is more stringent 

than any determined by the regional modeling, we are proposing to approve its use to trade 

excess NOx reductions for PM2.5 increases. We are not, however, proposing to approve its use to 

trade excess PM2.5 reductions for NOx increases, as this would result in under-control of NOx. 

We believe that the 2012 PM2.5 Plan includes an approvable 8:1 NOx:PM2.5 ratio trading 

mechanism for determining transportation conformity for the 2006 PM2.5 standard. We therefore

propose to approve the trading mechanism as described on p. C-32 in Appendix C of the 2012 

PM2.5 Plan as enforceable components of the transportation conformity program in the SJV for 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

91

the 2006 PM2.5 standard with the condition that trades are limited to substituting excess 

reductions in NOx for increases in PM2.5.

V. Reclassification as Serious Nonattainment and Serious Area SIP Requirements

A. Reclassification as Serious and Applicable Attainment Date

Section 188 of the Act outlines the process for classification of PM2.5 nonattainment areas 

and establishes the applicable attainment dates. Under the plain meaning of the terms of section 

188(b)(1) of the Act, the EPA has general authority to reclassify at any time before the 

applicable attainment date any area that the EPA determines cannot practicably attain the 

standard by such date. Accordingly, section 188(b)(1) of the Act is a general expression of 

delegated rulemaking authority. In addition, subparagraphs (A) and (B) of section 188(b)(1) 

mandate that the EPA reclassify “appropriate” PM10 nonattainment areas at specified time frames 

(i.e., by December 31, 1991 for the initial PM10 nonattainment areas, and within 18 months after 

the SIP submittal due date for subsequent nonattainment areas). These subparagraphs do not 

restrict the EPA’s general authority but simply specify that, at a minimum, it must be exercised 

at certain times.84

We have reviewed the impracticability demonstration in the Plan and Supplement and 

believe the State has adequately demonstrated that the San Joaquin Valley nonattainment area 

cannot practicably attain the 2006 PM2.5 standard by the applicable attainment date of December 

31, 2015 (see section IV.G, above). We have also reviewed recent PM2.5 monitoring data for the 

San Joaquin Valley available in the EPA’s Air Quality System (AQS) database. These data show 

that 24-hour PM2.5 levels in the SJV continue to be well above 35 μg/m3, the level of the 2006 

PM2.5 standard, and the recent trends in the Valley’s 24-hour PM2.5 levels are not consistent with 

 

84 For a general discussion of EPA’s interpretation of the reclassification provisions in section 188(b)(1) of the Act,

see the General Preamble, 57 FR 13498 at 13537-38 (April 16, 1992).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

92

a projection of attainment by the end of 2015 (see Table 7 below and Figure III-1 and Table III-1 

in the TSD). 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 29, 2014. We have taken steps to ensure the 

accuracy of this version, but it is not the official version.

93

Table 7: 24-Hour PM2.5 NAAQS Design Values1in μg/m3for Monitors in the SJV 

Site AQS ID 2005 2006 2007 2008 2009 2010 2011 2012 2013

Bakersfield

– Planz 60290016 54 60 68 70 70 65 55 47 60

– CA Ave 60290014 58 62 66 66 68 62 62 58 65

-- Golden State Hwy 60290010 60 64 69 64 66 64 n/a n/a n/a

Corcoran 60310004 55 58 61 52 53 49 46 43 49

Hanford 60311004 n/a n/a n/a n/a n/a n/a n/a 54 60

Visalia 61072002 55 56 58 57 59 51 47 47 56

Fresno

– Pacific 60195025 57 59 61 52 50 43 48 53 63

- Garland 60190011 60 58 63 58 60 54 58 592 622

Clovis 60195001 55 56 58 54 53 47 54 54 58

Tranquility 60192009 n/a n/a n/a n/a n/a n/a n/a 31 30

Madera 60392010 n/a n/a n/a n/a n/a n/a n/a 51 52

Merced

– M Street 60472510 45 45 48 50 51 45 39 40 49

- Coffee 60470003 n/a n/a n/a n/a n/a n/a 43 41 42

Turlock 60990006 n/a n/a n/a n/a n/a 55 51 49 53

Modesto 60990005 49 51 55 54 55 49 50 44 51

Manteca 60772010 n/a n/a n/a n/a n/a n/a n/a 38 37

Stockton 60771002 40 41 45 51 50 44 38 36 45

Source: U.S. EPA, 2013 Design Value Reports, PM2.5 Detailed Information Updated 8/24/14, available at http://www.epa.gov/airtrends/values.html

(“PM25_DesignValues_20112013_FINAL_08_28_14”). The term “n/a” means monitoring data is not available or does not meet minimum data completeness 

requirements (40 CFR part 50, appendix N).

1 The 24-hour design value for each monitor is based on the 3-year average of annual 98th percentile 24-hour PM2.5 concentrations. See 40 CFR part 50 appendix 

N. For example, the 24-hour design value for 2013 is the average of the 98th percentile PM2.5 concentrations for 2011, 2012, and 2013. The 2006 24-hour PM2.5

NAAQS is attained when the design value is 35 μg/m3 or less.

2 The Garland site was approved for replaced operation of the First Street site (AQS ID: 60190008) beginning with data collected in calendar year 2012. The 

design value reported represents a combined site record with the existing Garland site and old First Street site which ceased operation in early 2012.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

94

In accordance with section 188(b)(1) of the Act, the EPA is proposing to reclassify the 

SJV area from Moderate to Serious nonattainment for the 2006 24-hour PM2.5 standard of 35

μg/m3, based on the EPA’s determination that the SJV area cannot practicably attain this 

standard by the applicable attainment date of December 31, 2015.

Under section 188(c)(2) of the Act, 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....” The SJV area was designated nonattainment for the 

2006 PM2.5 standard effective December 14, 2009.85 Therefore, upon final reclassification of the 

SJV area as a Serious nonattainment area, the latest permissible attainment date under section 

188(c)(2) of the Act, for purposes of the 2006 PM2.5 standard in this area, will be December 31, 

2019. 

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

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

conditions. Before 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 

 

85 See 74 FR 58688 (November 13, 2009).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

95

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.86

B. Clean Air Act Requirements for Serious PM2.5 Nonattainment Area Plans

Upon reclassification as a Serious nonattainment area for the 2006 PM2.5 NAAQS, California 

will be required to submit additional SIP revisions to satisfy the statutory requirements that apply 

to Serious PM2.5 nonattainment areas, including the requirements of subpart 4 of part D, title I of 

the Act.

The Serious area SIP elements that California will be required to submit are as follows:

1. provisions to assure that the best available control measures (BACM), including best 

available control technology (BACT) for stationary sources, 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));

2. a demonstration (including air quality modeling) that the plan provides for attainment 

as expeditiously as practicable but no later than December 31, 2019, or where the 

state is seeking an extension of the attainment date under section 188(e), a 

demonstration that attainment by December 31, 2019 is impracticable and that the 

plan provides for attainment by the most expeditious alternative date practicable and 

no later than December 31, 2024 (CAA sections 188(c)(2) and 189(b)(1)(A)); 

3. plan provisions that require reasonable further progress (RFP) (CAA 172(c)(2));

 

86 For a discussion of EPA’s interpretation of the requirements of section 188(e), see “State Implementation Plans 

for Serious PM10 Nonattainment Areas, and Attainment Date Waivers for PM10 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”) at 42002; 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 EPA action on 

PM10 Plan for Maricopa County, Arizona but generally upholding EPA’s interpretation of CAA section 188(e)).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

96

4. 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)); 

5. 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));

6. 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));

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”87 thresholds from 100 tons per year (tpy) to 70 

tpy (CAA section 189(b)(3)).

The EPA is currently developing a proposed rulemaking to provide guidance to states on 

the attainment planning requirements in subparts 1 and 4 of part D, title I of the Act that apply to 

areas designated nonattainment for PM2.5. In the interim, EPA encourages the State to review the 

General Preamble and Addendum for guidance on how to implement these statutory 

requirements in the SJV PM2.5 nonattainment area.88

 

87 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)).

88 See generally the General Preamble, 57 FR 13498 (April 16, 1992) and Addendum, 59 FR 41998 (August 16, 

1994).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

97

C. Statutory Deadline for Submittal of the Serious Area Plan

Section 189(b)(2) of the Act states, in relevant part, that the state must submit the 

required BACM provisions “no later than 18 months after reclassification of the area as a Serious 

Area” and must submit the required attainment demonstration “no later than 4 years after 

reclassification of the area to Serious.” Thus, if a final reclassification of the area to Serious 

becomes effective in early 2015, the Act provides the state with up to 18 months after this date 

(i.e., until late 2016) to submit a BACM demonstration and up to 4 years after this date (i.e., until 

early 2019) to submit a Serious area attainment demonstration. Given the December 31, 2019

Serious area attainment date for the 2006 PM2.5 standard in this area under CAA section 

188(c)(2), EPA expects the State to adopt and submit a Serious area attainment demonstration

for the 2006 PM2.5 standard well before the statutory SIP submittal deadline in section 189(b)(2).

The Act does not specify a deadline for the State’s submittal of nonattainment NSR 

program revisions to lower the “major stationary source” threshold from 100 tons per year (tpy) 

to 70 tpy (CAA section 189(b)(3)) following reclassification of a Moderate PM2.5 nonattainment 

area as Serious nonattainment under subpart 4. Pursuant to EPA’s gap-filling authority in CAA 

section 301(a) and to effectuate the statutory control requirements in section 189 of the Act, the 

EPA proposes to require the State to submit these nonattainment NSR SIP revisions no later than 

12 months from the effective date of final reclassification of the SJV area as Serious 

nonattainment for the 2006 PM2.5 standard. We believe this timeframe will give the State 

sufficient time to make these relatively straightforward revisions to its nonattainment NSR SIP 

while assuring that new or modified major sources locating in the SJV area will be subject to the 

lower statutory major source thresholds expeditiously. We are requesting comment on this 

proposed 12-month timeframe for submission of the nonattainment NSR SIP revisions. We note 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

98

that nonattainment NSR SIP revisions that satisfy the requirement in CAA section 189(b)(3) for 

purposes of the 1997 PM2.5 standards may also satisfy this requirement for the 2006 PM2.5

standard.

VI. Reclassification of Indian Country

Eight Indian tribes are located within the boundaries of the San Joaquin Valley PM2.5

nonattainment area. These tribes are listed in Table 8 below. 

Table 8. Indian Tribes Located in San Joaquin Valley Pm2.5 Nonattainment Area

Big Sandy Rancheria of Mono Indians (including the Big Sandy Rancheria)

Cold Springs Rancheria of Mono Indians (including the Cold Springs Rancheria) 

North Fork Rancheria of Mono Indians (including the North Fork Rancheria)

Picayune Rancheria of Chukchansi Indians (including the Picayune Rancheria)

Santa Rosa Rancheria Tachi Yokut Tribe (including the Santa Rosa Rancheria)

Table Mountain Rancheria (including the Table Mountain Rancheria)

Tule River Indian Tribe (including the Tule River Reservation)

Tejon Indian Tribe

We have considered the relevance of our proposal to reclassify the SJV nonattainment area as 

Serious for the 2006 PM2.5 standard to each tribe located within the SJV area. We believe that the 

same facts and circumstances that support the proposal for the non-Indian country lands also 

support the proposal for Indian country89 located within the SJV nonattainment area. The EPA is 

therefore proposing to exercise our authority under CAA section 188(b)(1) to reclassify areas of 

Indian country geographically located in the SJV nonattainment area. Section 188(b)(1) broadly 

authorizes the EPA to reclassify a nonattainment area – including any Indian country located 

 

89 “Indian country” as defined at 18 U.S.C. 1151 refers to: “(a) all land within the limits of any Indian reservation 

under the jurisdiction of the United States Government, notwithstanding the issuance of any patent, and, including 

rights-of-way running through the reservation, (b) all dependent Indian communities within the borders of the 

United States whether within the original or subsequently acquired territory thereof, and whether within or without 

the limits of a state, and (c) all Indian allotments, the Indian titles to which have not been extinguished, including 

rights-of-way running through the same.”
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

99

within such an area – that EPA determines cannot practicably attain the relevant standard by the 

applicable attainment date. 

Elevated PM2.5 levels are a pervasive pollution problem throughout the SJV area. Directlyemitted PM2.5 and its precursor pollutants (NOx, SO2, VOC, and ammonia) are emitted 

throughout a nonattainment area and can be transported throughout that nonattainment area. 

Therefore, boundaries for nonattainment areas are drawn to encompass both areas with direct 

sources of the pollution problem as well as nearby areas in the same airshed. Initial 

classifications of nonattainment areas are coterminous with, that is, they match exactly, their 

boundaries. The EPA believes this approach best ensures public health protection from the 

adverse effects of PM2.5 pollution. Therefore, it is generally counterproductive from an air 

quality and planning perspective to have a disparate classification for a land area located within 

the boundaries of a larger nonattainment area, such as the areas of Indian country contained 

within the SJV PM2.5 nonattainment area. Moreover, violations of the 2006 PM2.5 standard, 

which are measured and modeled throughout the nonattainment area, as well as shared 

meteorological conditions, would dictate the same conclusion. Furthermore, emissions increases 

in portions of a PM2.5 nonattainment area that are left classified as Moderate could counteract the 

effects of efforts to attain the standard within the overall area because less stringent requirements 

would apply in those Moderate portions relative to those that would apply in the portions of the 

area reclassified to Serious. 

Uniformity of classification throughout a nonattainment area is thus a guiding principle and 

premise when an area is being reclassified. Equally, if the EPA believes it is likely that a given 

nonattainment area will not attain the PM2.5 standard by the applicable attainment date, then it 

may be an additional reason why it is appropriate to maintain a uniform classification within the 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

100

area and thus to reclassify the Indian country together with the balance of the nonattainment area. 

In this particular case, we are proposing to determine, based on the State’s demonstration and 

current ambient air quality trends, that the SJV nonattainment area cannot practicably attain the 

2006 PM2.5 standards by the applicable Moderate area attainment date of December 31, 2015. 

In light of the considerations outlined above that support retention of a uniformly-classified 

PM2.5 nonattainment area, and our finding that is impracticable for the area to attain by the 

applicable attainment date, we propose to reclassify the areas of Indian country within the San 

Joaquin Valley nonattainment area to Serious for the 2006 PM2.5 standard.

The effect of reclassification would be to lower the applicable “major source” threshold for 

purposes of the nonattainment new source review program and the Title V operating permit 

program from its current level of 100 tpy to 70 tpy (CAA sections 189(b)(3) and 501(2)(B)) thus 

subjecting more new or modified stationary sources to these requirements. The reclassification 

may also lower the de minimis threshold under the CAA’s General Conformity requirements (40 

CFR part 93, subpart B) from 100 tpy to 70 tpy. Under the General Conformity requirements, 

Federal agencies bear the responsibility of determining conformity of actions in nonattainment 

and maintenance areas that require Federal permits, approvals, or funding. Such permits, 

approvals or funding by Federal agencies for projects in these areas of Indian country may be 

more difficult to obtain because of the lower de minimis thresholds. 

Given the potential implications of the reclassification, the EPA has contacted tribal officials 

to invite government-to-government consultation on this rulemaking effort.90 The EPA 

 

90 We sent letters to seven tribal officials regarding government-to-government consultation on September 30, 

2014.. EPA inadvertently did not send a letter to the Tejon Indian Tribe, therefore, we sent a letter to the chairperson 

of the Tejon Indian Tribe inviting government to government consultation on our proposed reclassification of the 

SJV PM2.5 nonattainment area on December 18, 2014. All eight letters can be found in the docket for today’s 

action.
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

101

specifically solicits additional comment on this proposed rule from tribal officials. We note that 

although eligible tribes may opt to seek EPA approval of relevant tribal programs under the 

CAA, none of the affected tribes will be required to submit an implementation plan to address 

this reclassification.

VII. Summary of Proposed Actions and Request for Public Comment

Under CAA section 110(k)(3), the EPA is proposing to approve the following elements of 

the 2012 PM2.5 Plan and Supplement submitted by California to address the CAA’s Moderate 

area planning requirements for the 2006 PM2.5 NAAQS in the San Joaquin Valley nonattainment 

area:

1. the 2007 base year emissions inventories as meeting the requirements of CAA section 

172(c)(3);

2. the reasonably available control measures/reasonably available control technology 

demonstration as meeting the requirements of CAA sections 172(c)(1) and 189(a)(1)(C);

3. the reasonable further progress demonstration as meeting the requirements of CAA section 

172(c)(2);

4. the demonstration that attainment by the Moderate area attainment date of December 31, 

2015 is impracticable as meeting the requirements of CAA section 189(a)(1)(B)(ii); and

5. SJVUAPCD's commitments to adopt and implement specific rules and measures in 

accordance with the schedule provided in Chapter 5 of the 2012 PM2.5 Plan to achieve the 

emissions reductions shown therein, and to submit these rules and measures to ARB within 30 

days of adoption for transmittal to EPA as a revision to the SIP, as stated on p. 4 of SJVUAPCD 

Governing Board Resolution 2012-12-19. 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

102

In addition, the EPA is proposing to approve the 2014 and 2017 motor vehicle emissions 

budgets as shown in Table 6 above because they are derived from an approvable RFP 

demonstration and meet the requirements of CAA section 176(c) and 40 CFR part 93, subpart A, 

provided the State completes its public review process and adopts and submits these budgets in 

final form prior to our final action on the Plan and Supplement. The EPA is also proposing to 

approve, in accordance with 40 CFR 93.124, the trading mechanism as described on p. C-32 in 

Appendix C of the 2012 PM2.5 Plan as an enforceable component of the transportation 

conformity program for the SJV for the 2006 PM2.5 standard, with the condition that trades are 

limited to substituting excess reductions in NOx for increases in PM2.5.

The EPA is proposing to disapprove the PM2.5 interpollutant trading ratios provided in 

Appendix H of the 2012 PM2.5 Plan for NNSR permitting purposes. Under section 179(a) of the 

CAA, final disapproval of a SIP submittal that addresses a requirement of part D, title I of the 

Act or is required in response to a finding of substantial inadequacy as described in CAA section 

110(k)(5) (SIP Call) starts a sanctions clock. The NNSR interpollutant trading ratios provided in 

the 2012 PM2.5 Plan were not submitted to meet either of these requirements. Therefore, if we 

take final action to disapprove this component of the Plan, no sanctions will be triggered. 

Disapproval of a SIP element also triggers the requirement under CAA section 110(c) for EPA to 

promulgate a FIP no later than 2 years from the date of the disapproval unless the State corrects 

the deficiency, and the Administrator approves the plan or plan revision, before the 

Administrator promulgates such FIP. Disapproval of these NNSR interpollutant trading ratios, 

however, would not create any deficiency in the plan and therefore would not trigger the 

obligation on EPA to promulgate a FIP under section 110(c).
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

103

Finally, pursuant to CAA section 188(b)(1), the EPA is proposing to reclassify the San 

Joaquin Valley PM2.5 nonattainment area, including the Indian country within it, as Serious

nonattainment for the 2006 PM2.5 standard based on the Agency’s determination that the SJV 

area cannot practicably attain the 2006 PM2.5 standard by the Moderate area attainment date of 

December 31, 2015. Upon final reclassification as a Serious nonattainment area, California will 

be required to submit, within 18 months after the effective date of reclassification, provisions to 

assure that BACM shall be implemented no later than 4 years after the date of reclassification 

and to submit, within 4 years after the effective date of reclassification, a Serious area plan that 

satisfies the requirements of part D of title I of the Act, including a demonstration that the plan 

provides for attainment of the 2006 PM2.5 standard as expeditiously as practicable but no later 

than December 31, 2019, or by the most expeditious alternative date practicable and no later than 

December 31, 2024, in accordance with the requirements of CAA sections 189(b) and 188(e).

In addition, because the EPA is proposing to similarly reclassify areas of Indian country 

within the SJV PM2.5 nonattainment area as Serious nonattainment for the 2006 PM2.5 standard, 

consistent with our proposed reclassification of the surrounding non-Indian country lands, EPA 

has invited consultation with interested tribes concerning this issue. We note that although 

eligible tribes may seek the EPA’s approval of relevant tribal programs under the CAA, none of 

the affected tribes will be required to submit an implementation plan to address this 

reclassification.

We will accept comments from the public on these proposals for the next 45 days. The 

deadline and instructions for submission of comments are provided in the “Date” and 

“Addresses” sections at the beginning of this preamble.

VIII. Statutory and Executive Order Reviews
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

104

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 it 

does not contain any information collection activities. 

C. Regulatory Flexibility Act (RFA)

I certify that this action will not have a significant economic impact on a substantial 

number of small entities under the RFA. This action will not impose any requirements on small 

entities. This proposed action would approve State law as meeting Federal requirements and 

would not impose additional requirements beyond those imposed by State law. Additionally, the 

proposed rule would reclassify the SJV nonattainment area as Serious nonattainment for the 

2006 PM2.5 NAAQS, and would not itself regulate small entities.

D. Unfunded Mandates Reform Act (UMRA)

This action does not contain an unfunded mandate of $100 million or more as described 

in UMRA, and does not significantly or uniquely affect small governments. This proposed action 

would approve State law as meeting Federal requirements and would not impose additional 

requirements beyond those imposed by State law. Additionally, the proposed action would 

reclassify the SJV nonattainment area as Serious nonattainment for the 2006 PM2.5 NAAQS, and 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

105

would not itself impose any federal intergovernmental mandate. The proposed action would not 

require any tribes to submit implementation plans.

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

Executive Order 13175, entitled “Consultation and Coordination with Indian Tribal 

Governments” (65 FR 67249, November 9, 2000), requires EPA to develop an accountable 

process to ensure “meaningful and timely input by tribal officials in the development of 

regulatory policies that have tribal implications.” “Policies that have Tribal implications” is 

defined in the Executive Order to include regulations that have “substantial direct effects on one 

or more Indian tribes, on the relationship between the Federal government and the Indian tribes, 

or on the distribution of power and responsibilities between the Federal government and Indian 

Tribes.”

Eight Indian tribes are located within the boundaries of the SJV nonattainment area for 

the 2006 PM2.5 NAAQS: the Big Sandy Rancheria of Mono Indians of California, the Cold 

Springs Rancheria of Mono Indians of California, the North Fork Rancheria of Mono Indians of 

California, the Picayune Rancheria of Chukchansi Indians of California, the Santa Rosa 

Rancheria of the Tachi Yokut Tribe, the Table Mountain Rancheria of California, the Tejon 

Indian Tribe, and the Tule River Indian Tribe of the Tule River Reservation.

EPA’s proposed approvals of the SIP elements submitted by California to address the 

2006 PM2.5 standard in the SJV would not have tribal implications because the SIP is not 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

106

approved to apply on any Indian reservation land or in any other area where EPA or an Indian 

tribe has demonstrated that a tribe has jurisdiction. In those areas of Indian country, the 

proposed SIP approvals do not have tribal implications and will not impose substantial direct 

costs on tribal governments or preempt tribal law as specified by Executive Order 13175 (65 FR 

67249, November 9, 2000).

The EPA has concluded that the proposed reclassification might have tribal implications 

for the purposes of Executive Order 13175, but would not impose substantial direct costs upon 

the tribes, nor would it preempt Tribal law. We note that none of the tribes located in the SJV 

nonattainment area has requested eligibility to administer programs under the CAA. The 

proposed reclassification would affect the EPA’s implementation of the new source review 

program because of the lower “major source” threshold triggered by reclassification (70 tons per 

year for direct PM2.5 and precursors to PM2.5). The proposed reclassification may also affect new 

or modified stationary sources proposed in these areas that require Federal permits, approvals, or 

funding. Such projects are subject to the requirements of EPA’s General Conformity rule, and 

Federal permits, approvals, or funding for the projects may be more difficult to obtain because of 

the lower de minimis thresholds triggered by reclassification. 

Given the potential implications, the EPA contacted tribal officials during the process of 

developing this proposed rule to provide an opportunity to have meaningful and timely input into 

its development. On September 30, 2014, we sent letters to leaders of the seven tribes with areas 

of Indian country in the SJV nonattainment area inviting government-to-government consultation 

on the rulemaking effort. We requested that the tribal leaders, or their designated consultation 

representatives, provide input or request government-to-government consultation by October 27, 

2014. We did not receive a response from any of the seven tribes. As noted above, the EPA 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

107

inadvertently did not send a letter to the Tejon Indian Tribe at the time we sent letters to the other 

seven tribes. We contacted the chairperson of the Tejon Indian Tribe on December 18, 2014 to 

offer them an opportunity for government-to-government consultation. We intend to continue 

communicating with all eight tribes located within the boundaries of the SJV nonattainment area 

for the 2006 PM2.5 NAAQS as we move forward in developing a final rule. EPA specifically 

solicits additional comment on this proposed rule from tribal officials.

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. This proposed action is not subject to Executive Order 13045 

because it would only approve a state air quality plan implementing a federal standard and 

reclassify the SJV nonattainment area as Serious nonattainment for the 2006 PM2.5 NAAQS, 

triggering Serious area planning requirements under the CAA. This proposed action does not 

establish an environmental standard intended to mitigate health or safety risks. 

H. Executive Order 13211, Actions that Significantly Affect Energy Supply, 

Distribution, or Use

This proposed 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

This rulemaking does not involve technical standards. 
This document is a prepublication version signed by EPA Regional Administrator Jared Blumenfeld on December 

29, 2014. We have taken steps to ensure the accuracy of this version, but it is not the official version.

108

J. Executive Order 12898: Federal Actions to Address Environmental Justice in 

Minority Populations and Low-Income Population

EPA has determined that this action will not have potential disproportionately high and 

adverse human health or environmental effects on minority or low-income populations because it 

does not affect the level of protection provided to human health or the environment. This 

proposed action would only approve a state air quality plan implementing a federal standard and 

reclassify the SJV nonattainment area as Serious nonattainment for the 2006 PM2.5 NAAQS, 

triggering additional Serious area planning requirements under the CAA.

List of Subjects in 40 CFR Part 52

Environmental protection, Air pollution control, incorporation by reference, Intergovernmental 

relations, Oxides of nitrogen, Particulate matter, Reporting and recordkeeping requirements, 

Volatile organic compounds.

List of Subjects in 40 CFR Part 81

Air pollution control, Incorporation by reference

AUTHORITY: 42 U.S.C. 7401 et seq. -

_______________________ _____________________________________

Dated: Jared Blumenfeld,

Regional Administrator,

EPA Region 9