[Federal Register Volume 81, Number 26 (Tuesday, February 9, 2016)]
[Proposed Rules]
[Pages 6936-6986]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-02325]



[[Page 6935]]

Vol. 81

Tuesday,

No. 26

February 9, 2016

Part II





Environmental Protection Agency





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40 CFR Parts 52 and 81





Approval and Disapproval of California Air Plan; San Joaquin Valley 
Serious Area Plan and Attainment Date Extension for the 1997 
PM<INF>2.5</INF> NAAQS; Proposed Rule

Federal Register / Vol. 81 , No. 26 / Tuesday, February 9, 2016 / 
Proposed Rules

[[Page 6936]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and Part 81

[EPA-R09-OAR-2015-0432; FRL-9942-00-Region 9]


Approval and Disapproval of California Air Plan; San Joaquin 
Valley Serious Area Plan and Attainment Date Extension for the 1997 
PM<INF>2.5</INF> NAAQS

AGENCY: U.S. Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve, conditionally approve, and disapprove state implementation 
plan (SIP) revisions submitted by California to address Clean Air Act 
(CAA or Act) requirements for the 1997 24-hour and annual fine 
particulate matter (PM<INF>2.5</INF>) national ambient air quality 
standards (NAAQS) in the San Joaquin Valley (SJV) Serious 
PM<INF>2.5</INF> nonattainment area. As part of this action, the EPA is 
proposing to grant extensions of the Serious area attainment dates for 
the 1997 24-hour and annual PM<INF>2.5</INF> NAAQS in the SJV to 
December 31, 2018 and December 31, 2020, respectively, based on a 
conclusion that the State has satisfied the statutory criteria for 
these extensions of the Serious area attainment date. The EPA is also 
proposing to approve inter-pollutant trading ratios for use in 
transportation conformity analyses.

DATES: Any comments must arrive by March 10, 2016.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2015-0432 at http://www.regulations.gov, or via email to 
<a href="/cdn-cgi/l/email-protection#a3cec2dad08dd1ccd1dae3c6d3c28dc4ccd5"><span class="__cf_email__" data-cfemail="bcd1ddc5cf92ced3cec5fcd9ccdd92dbd3ca">[email protected]</span></a>. For comments submitted at Regulations.gov, follow 
the online instructions for submitting comments. Once submitted, 
comments cannot be edited or removed from Regulations.gov. For either 
manner of submission, the EPA may publish any comment received to its 
public docket. Do not submit electronically any information you 
consider to be Confidential Business Information (CBI) or other 
information whose disclosure is restricted by statute. Multimedia 
submissions (audio, video, etc.) must be accompanied by a written 
comment. The written comment is considered the official comment and 
should include discussion of all points you wish to make. The EPA will 
generally not consider comments or comment contents located outside of 
the primary submission (i.e., on the Web, cloud, or other file sharing 
system). For additional submission methods, please contact the person 
identified in the FOR FURTHER INFORMATION CONTACT section. For the full 
EPA public comment policy, information about CBI or multimedia 
submissions, and general guidance on making effective comments, please 
visit http://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Rory Mays, Air Planning Office (AIR-
2), EPA Region 9, (415) 972-3227, <a href="/cdn-cgi/l/email-protection#365b574f45184459444f7653465718515940"><span class="__cf_email__" data-cfemail="bcd1ddc5cf92ced3cec5fcd9ccdd92dbd3ca">[email protected]</span></a>.

SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us'' and 
``our'' refer to the EPA.

Table of Contents

I. Background
II. Summary of the San Joaquin Valley 2015 PM<INF>2.5</INF> Plan
III. Completeness Review of the San Joaquin Valley 2015 
PM<INF>2.5</INF> Plan
IV. Clean Air Act Requirements for PM<INF>2.5</INF> Serious Area 
Plans
    A. PM<INF>2.5</INF> Serious Area Plan Requirements
    B. Implementation of Best Available Control Measures
    C. Implementation of Reasonably Available Control Measures
    D. Extension of the Serious Area Attainment Date Beyond 2015
V. Review of the San Joaquin Valley PM<INF>2.5</INF> Serious Area 
Plan and Extension Application
    A. Emissions Inventory
    B. Adequate Monitoring Network
    C. PM<INF>2.5</INF> Precursors
    D. Best Available Control Measures and Most Stringent Measures
    E. Extension of Serious Area Attainment Date Under CAA Section 
188(e)
    1. Application for an Attainment Date Extension
    2. Demonstration That Attainment by Serious Area Attainment Date 
Is Impracticable
    3. Compliance With All Requirements and Commitments in the 
Implementation Plan
    4. Demonstration That the Implementation Plan Includes the Most 
Stringent Measures
    5. Demonstration of Attainment by the Most Expeditious 
Alternative Date Practicable
    F. Reasonable Further Progress and Quantitative Milestones
    G. Contingency Measures
    H. Major Stationary Source Control Requirements Under CAA 
Section 189(e)
    I. Motor Vehicle Emission Budgets
VI. Summary of Proposed Actions and Request for Public Comment
VII. Statutory and Executive Order Reviews

I. Background

    On July 18, 1997, the EPA established new national ambient air 
quality standards (NAAQS) for particles less than or equal to 2.5 
micrometers ([mu]m) in diameter (PM<INF>2.5</INF>), including an annual 
standard of 15.0 micrograms per cubic meter ([mu]g/m\3\) based on a 3-
year average of annual mean PM<INF>2.5</INF> concentrations, and a 24-
hour (daily) standard of 65 [mu]g/m\3\ based on a 3-year average of 
98th percentile 24-hour PM<INF>2.5</INF> concentrations.\1\ The EPA 
established these standards after considering substantial evidence from 
numerous health studies demonstrating that serious health effects are 
associated with exposures to PM<INF>2.5</INF> concentrations above 
these levels.
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    \1\ 62 FR 36852 (July 18, 1997) and 40 CFR 50.7. Effective 
December 18, 2006, EPA strengthened the 24-hour PM<INF>2.5</INF> 
NAAQS by lowering the level to 35 [mu]g/m\3\. 71 FR 61144 (October 
17, 2006) and 40 CFR 50.13. Effective March 18, 2013, EPA 
strengthened the primary annual PM<INF>2.5</INF> NAAQS by lowering 
the level to 12.0 [mu]g/m\3\ while retaining the secondary annual 
PM<INF>2.5</INF> NAAQS at the level of 15.0 [mu]g/m\3\. 78 FR 3086 
(January 15, 2013) and 40 CFR 50.18. In this preamble, all 
references to the PM<INF>2.5</INF> NAAQS, unless otherwise 
specified, are to the 1997 24-hour standards (65 [mu]g/m\3\) and 
annual standards (15.0 [mu]g/m\3\) as codified in 40 CFR 50.7.
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    Epidemiological studies have shown statistically significant 
correlations between elevated PM<INF>2.5</INF> levels and premature 
mortality. Other important health effects associated with 
PM<INF>2.5</INF> exposure include aggravation of respiratory and 
cardiovascular disease (as indicated by increased hospital admissions, 
emergency room visits, absences from school or work, and restricted 
activity days), changes in lung function and increased respiratory 
symptoms, as well as new evidence for more subtle indicators of 
cardiovascular health. Individuals particularly sensitive to 
PM<INF>2.5</INF> exposure include older adults, people with heart and 
lung disease, and children.\2\
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    \2\ EPA, Air Quality Criteria for Particulate Matter, No. EPA/
600/P-99/002aF and EPA/600/P-99/002bF, October 2004.
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    PM<INF>2.5</INF> can be emitted directly into the atmosphere as a 
solid or liquid particle (primary PM<INF>2.5</INF> or direct 
PM<INF>2.5</INF>) or can be formed in the atmosphere as a result of 
various chemical reactions from precursor emissions of nitrogen oxides, 
sulfur oxides, volatile organic compounds, and ammonia (secondary 
PM<INF>2.5</INF>).\3\
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    \3\ 72 FR 20586, 20589 (April 25, 2007).
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    Following promulgation of a new or revised NAAQS, the EPA is 
required under Clean Air Act (CAA) section 107(d) to designate areas 
throughout the nation as attaining or not attaining the NAAQS. On 
January 5, 2005, the EPA published initial air quality designations for 
the 1997 annual and 24-hour PM<INF>2.5</INF> NAAQS, using air quality 
monitoring data for the three-year periods of 2001-2003 and 2002-
2004.\4\ These designations became effective April 5, 2005.\5\ The EPA 
designated the

[[Page 6937]]

San Joaquin Valley (SJV) area as nonattainment for both the 1997 annual 
PM<INF>2.5</INF> standard (15.0 [mu]g/m\3\) and the 1997 24-hour 
PM<INF>2.5</INF> standard (65 [mu]g/m\3\).\6\
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    \4\ 70 FR 944 (January 5, 2005).
    \5\ Id.
    \6\ 40 CFR 81.305. The 2001-2003 design values for the San 
Joaquin Valley were 21.8 [mu]g/m3 for the annual standard and 82 
[mu]g/m3 for the 24-hour standard. See EPA design value workbook 
dated August 12, 2014, worksheets ``Table 3a'' and ``Table 3b.''
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    The SJV PM<INF>2.5</INF> nonattainment area encompasses over 23,000 
square miles and includes all or part of eight counties: San Joaquin, 
Stanislaus, Merced, Madera, Fresno, Tulare, Kings, and the valley 
portion of Kern.\7\ The area is home to 4 million people and is the 
nation's leading agricultural region. Stretching over 250 miles from 
north to south and averaging 80 miles wide, it is partially enclosed by 
the Coast Mountain range to the west, the Tehachapi Mountains to the 
south, and the Sierra Nevada range to the east. The San Joaquin Valley 
Unified Air Pollution Control District (SJVUAPCD or District) has 
primary responsibility for developing plans to provide for attainment 
of the NAAQS in this area. The District works cooperatively with the 
California Air Resources Board (CARB) in preparing attainment plans. 
Authority for regulating sources under State jurisdiction in the SJV is 
split between the District, which has responsibility for regulating 
stationary and most area sources, and CARB, which has responsibility 
for regulating most mobile sources.
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    \7\ For a precise description of the geographic boundaries of 
the San Joaquin Valley PM<INF>2.5</INF> nonattainment area, see 40 
CFR 81.305.
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    Between 2007 and 2011, California made six SIP submissions to 
address nonattainment area planning requirements for the 1997 
PM<INF>2.5</INF> NAAQS in the SJV.\8\ We refer to these submissions 
collectively as the ``2008 PM<INF>2.5</INF> Plan.'' On November 9, 
2011, the EPA approved all elements of the 2008 PM<INF>2.5</INF> Plan 
except for the contingency measures, which the EPA disapproved.\9\ As 
part of that action and pursuant to CAA section 172(a)(2)(A), the EPA 
granted California's request for an extension of the attainment date 
for the SJV area to April 5, 2015.\10\ The EPA took these actions in 
accordance with the ``Clean Air Fine Particle Implementation Rule,'' 
which the EPA issued in April 2007 to assist states in their 
development of SIPs to meet the Act's attainment planning requirements 
for the 1997 PM<INF>2.5</INF> NAAQS (hereafter ``2007 PM<INF>2.5</INF> 
Implementation Rule'').\11\ In July 2013, the State submitted a revised 
PM<INF>2.5</INF> contingency measure plan for the SJV, which the EPA 
fully approved in May 2014.\12\
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    \8\ 76 FR 69896 at n. 2 (November 9, 2011).
    \9\ Id. at 69924.
    \10\ Id. Under CAA section 172(a)(2)(A), the attainment date for 
a nonattainment area is ``the date by which attainment can be 
achieved as expeditiously as practicable, but no later than five 
years from the date such area was designated nonattainment,'' except 
that EPA may extend the attainment date as appropriate for a period 
no greater than ten years from the date of designation as 
nonattainment, considering the severity of nonattainment and the 
availability and feasibility of pollution control measures. CAA 
section 172(a)(2)(A); see also 40 CFR 51.1004(a) and (b).
    \11\ 72 FR 20583 (April 25, 2007), codified at 40 CFR part 51, 
subpart Z. This rule was premised on EPA's prior interpretation of 
the Act as allowing for implementation of the PM<INF>2.5</INF> NAAQS 
solely pursuant to the general nonattainment area provisions of 
subpart 1 and not the more specific provisions for particulate 
matter nonattainment areas in subpart 4 of part D, title I of the 
Act.
    \12\ 79 FR 29327 (May 22, 2014).
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    On January 4, 2013, the U.S. Court of Appeals for the D.C. Circuit 
(``D.C. Circuit'') issued its decision in a challenge by the Natural 
Resources Defense Council (NRDC) to the EPA's 2007 PM<INF>2.5</INF> 
Implementation Rule.\13\ In NRDC, the court held that the EPA erred in 
implementing the 1997 PM<INF>2.5</INF> standards solely pursuant to the 
general implementation requirements of subpart 1, without also 
considering the requirements specific to nonattainment areas for 
particles less than or equal to 10 [mu]m in diameter (PM<INF>10</INF>) 
in subpart 4, part D of title I of the CAA. The court reasoned that the 
plain meaning of the CAA requires implementation of the 1997 
PM<INF>2.5</INF> standards under subpart 4 because PM<INF>2.5</INF> 
particles fall within the statutory definition of PM<INF>10</INF> and 
are thus subject to the same statutory requirements as PM<INF>10</INF>. 
The court remanded the rule, without vacatur, and instructed the EPA 
``to repromulgate these rules pursuant to Subpart 4 consistent with 
this opinion.'' \14\
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    \13\ Natural Resources Defense Council v. EPA, 706 F.3d 428 
(D.C. Cir. 2013) (``NRDC'').
    \14\ Id.
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    Consistent with the NRDC decision, on June 2, 2014, the EPA 
published a final rule classifying all areas designated nonattainment 
for the 1997 and/or 2006 PM<INF>2.5</INF> standards as ``moderate'' 
nonattainment under subpart 4.\15\ Because this rulemaking did not 
affect any action that the EPA had previously taken under section 
110(k) of the Act on a SIP for a PM<INF>2.5</INF> nonattainment area, 
the April 5, 2015 attainment date that the EPA had approved for the SJV 
area in November 2011 remained in effect.\16\ On April 7, 2015, the EPA 
published a final rule reclassifying the SJV area as ``serious'' 
nonattainment under subpart 4, based on the EPA's determination that 
the area could not practicably attain the 1997 PM<INF>2.5</INF> 
standards by the April 5, 2015 attainment date.\17\ This 
reclassification was based upon the EPA's evaluation of ambient air 
quality data from the 2003-2014 period, including the 2012-2014 design 
value, indicating that it was not practicable for certain monitoring 
sites within the SJV area to show PM<INF>2.5</INF> design values at or 
below the level of the 1997 PM<INF>2.5</INF> NAAQS by April 5, 
2015.\18\
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    \15\ 79 FR 31566 (June 2, 2014). As part of this rulemaking, EPA 
established a December 31, 2014 deadline for states to submit 
attainment-related and nonattainment new source review (NNSR) SIP 
elements required for PM<INF>2.5</INF> nonattainment areas pursuant 
to subpart 4. Id.
    \16\ Id. at 31569.
    \17\ 80 FR 18528 (April 7, 2015).
    \18\ Id. at 18529; see also proposed rule, 80 FR 1482 (January 
12, 2015). Air quality data for 2012-2014 indicated that the highest 
monitors in the SJV area had design values of 19.7 [mu]g/m\3\ for 
the annual standard and 71 [mu]g/m\3\ for the 24-hour standard.
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    As a consequence of its reclassification as a Serious 
PM<INF>2.5</INF> nonattainment area, the SJV area became subject to a 
new attainment date under CAA section 188(c)(2) and the requirement to 
submit a Serious area plan that satisfies the requirements of part D of 
title I of the Act, including the requirements of subpart 4, for the 
1997 PM<INF>2.5</INF> NAAQS.\19\ Under subpart 4, the attainment date 
for an area classified as Serious is as expeditiously as practicable, 
but no later than the end of the tenth calendar year following 
designation. As explained in the EPA's final reclassification action, 
the Serious area plan for SJV must include provisions to assure that 
the best available control measures (BACM) for the control of direct 
PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors shall be implemented 
no later than 4 years after the area is reclassified (CAA section 
189(b)(1)(B)), and a demonstration (including air quality modeling) 
that the plan provides for attainment as expeditiously as practicable 
but no later than December 31, 2015, which is the latest permissible 
attainment date under CAA section 188(c)(2).\20\
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    \19\ 80 FR 18258 at 18530-18532.
    \20\ Id.
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    Given the December 31, 2015 outermost attainment deadline for the 
SJV area under section 188(c)(2), the EPA noted its expectation that 
the State would adopt and submit a Serious area plan for the SJV well 
before the statutory SIP submission deadlines in CAA section 
189(b)(2).\21\ The EPA also noted that, in light of the available 
ambient air quality data and the short amount of time available before 
the December 31, 2015 attainment date, California may choose to submit 
a request for an extension of the Serious area attainment date pursuant 
to CAA

[[Page 6938]]

section 188(e) simultaneously with its submission of a Serious area 
plan for the area.\22\
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    \21\ Id. at 18531.
    \22\ Id.
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II. Summary of the San Joaquin Valley 2015 PM<INF>2.5</INF> Plan

    We are proposing action on two California SIP submissions that 
address the 1997 annual and 24-hour PM<INF>2.5</INF> NAAQS in the San 
Joaquin Valley. The first submission is the ``2015 Plan for the 1997 
PM<INF>2.5</INF> Standard,'' which the State submitted to the EPA on 
June 25, 2015.\23\ The second submission is the ``2018 Transportation 
Conformity Budgets for the San Joaquin Valley PM<INF>2.5</INF> SIP, 
Plan Supplement,'' which the State submitted to the EPA on August 13, 
2015.\24\ We refer to these SIP submissions collectively herein as the 
``2015 PM<INF>2.5</INF> Plan'' or ``the Plan.'' The 2015 
PM<INF>2.5</INF> Plan is a PM<INF>2.5</INF> Serious area plan for the 
SJV and includes a request to extend the applicable attainment dates 
for the annual and 24-hour PM<INF>2.5</INF> standards by five and three 
years, respectively, on the basis that attainment by December 31, 2015 
is impracticable, in accordance with CAA section 188(e).
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    \23\ Letter dated June 25, 2015, from Richard Corey, Executive 
Officer, California Air Resources Board, to Jared Blumenfeld, 
Regional Administrator, EPA Region 9, with enclosures.
    \24\ Letter dated August 13, 2015, from Richard Corey, Executive 
Officer, California Air Resources Board, to Jared Blumenfeld, 
Regional Administrator, EPA Region 9, with enclosures.
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    The first submission includes two sets of documents: The ``2015 
Plan for the PM<INF>2.5</INF> Standard,'' adopted by the SJVUAPCD 
Governing Board on April 16, 2015 and the ``Staff Report, ARB Review of 
San Joaquin Valley PM<INF>2.5</INF> State Implementation Plan,'' 
adopted by CARB on May 21, 2015 (``CARB Staff Report''). Both sets of 
documents include Appendices A and B. To distinguish between the two 
sets of appendices, we refer to those adopted by the SJVUAPCD Governing 
Board simply as ``Appendix A'' (``Ambient PM<INF>2.5</INF> Data 
Analysis'') and ``Appendix B'' (``Emission Inventory Tables''), and we 
refer to the additional appendices that accompany CARB's Staff Report 
as ``WOEA'' for Appendix A (``San Joaquin Valley PM<INF>2.5</INF> 
Weight of Evidence Analysis'') and ``CARB Staff Report, Appendix B'' 
for Appendix B (``San Joaquin Valley PM<INF>2.5</INF> SIP Additional 
Emission Reductions Towards Meeting Aggregate Commitment'').
    The 2015 PM<INF>2.5</INF> Plan includes an Executive Summary and a 
description of air quality standards and requirements applicable to the 
SJV (Chapter 1), PM<INF>2.5</INF> challenges and trends (Chapter 2, 
including a summary of the District's determination regarding air 
pollutant precursors to PM<INF>2.5</INF>), and health impacts and risk 
reduction strategy (Chapter 3).\25\ Chapter 4 presents the SJVUAPCD's 
request for an extension of the PM<INF>2.5</INF> Serious area 
attainment date; summary arguments for how the SJVUAPCD claims it has 
met the extension requirements of CAA section 188(e), including a 
demonstration that attainment of the 1997 PM<INF>2.5</INF> NAAQS by 
December 31, 2015 is impracticable; a demonstration, as detailed in 
Appendix F (``Attainment Demonstration (Provided by ARB)''), of 
attainment by the most expeditious alternative date practicable; and 
financial commitments to achieve further emission reductions by 
replacing heavy duty trucks and residential wood burning devices 
through the District's truck replacement incentive program and Burn 
Cleaner Incentive Program, respectively.
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    \25\ See 2015 PM<INF>2.5</INF> Plan, Appendix A, regarding 
trends.
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    Chapter 5, Appendix C (``BACM and MSM for Stationary and Area 
Sources''), and Appendix D (``BACM and MSM for Mobile Sources (Provided 
by ARB)'') provide analyses of District and State rules to address the 
statutory requirements for Best Available Control Measures (BACM) and 
Most Stringent Measures (MSM) and the District's calculation of de 
minimis thresholds for directly emitted PM<INF>2.5</INF> (direct 
PM<INF>2.5</INF>), nitrogen oxides (NO<INF>X</INF>), and sulfur oxides 
(SO<INF>X</INF>).
    Chapters 6 and 7 present the District's summary analysis to address 
the planning requirements for PM<INF>2.5</INF> Serious nonattainment 
areas under subparts 1 and 4 of part D, title I of the CAA, including 
the statutory requirements for extension requests under CAA section 
188(e). These include the District's analysis and demonstration, in 
Chapter 6, of its compliance with the requirements and commitments in 
the implementation plan for the 1997 PM<INF>2.5</INF> NAAQS, reasonably 
available control measures (RACM), reasonable further progress (RFP) 
and quantitative milestones, contingency measures, transportation 
conformity budgets for 2014, 2017, and 2020, and permitting of new and 
modified major stationary sources (i.e., nonattainment new source 
review (NSR)).\26\ Chapter 7 describes the State's and District's 
regulatory control strategy, incentive programs, technology advancement 
program, legislative strategy, and public outreach.\27\ Finally, 
Chapter 8 presents the District's commitments to evaluate opportunities 
for additional emission reductions in general, and specifically from 
three source categories: Flares, asphalt, and conservation management 
practices.
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    \26\ See also, 2015 PM<INF>2.5</INF> Plan, Appendix B and 
Appendix G (``New Source Review (NSR) and Emission Reduction Credits 
(ERCs)'').
    \27\ See also, 2015 PM<INF>2.5</INF> Plan, Appendix E 
(``Incentive and Other Non-regulatory Strategies'').
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    The additional documents adopted by CARB on May 21, 2015 supplement 
the analysis and demonstrations of those adopted by SJVUAPCD. In 
particular, the CARB Staff Report presents estimated emission 
reductions by 2018 and 2020 from specific District control measures; an 
accounting of how the State has complied with its control measure and 
emission reduction commitments in the 2008 PM<INF>2.5</INF> Plan; 
analysis of ammonia effects on reasonable further progress planning; 
and 2021 attainment year contingency reductions from specific 
measures.\28\ These additional documents also include the methodology 
and results for the attainment demonstration,\29\ a weight of evidence 
analysis for the attainment demonstration (WOEA), a discussion of 
additional emission reductions achieved towards the aggregate tonnage 
commitments of the 2008 PM<INF>2.5</INF> Plan (CARB Staff Report, 
Appendix B), and technical clarifications for the 2015 PM<INF>2.5</INF> 
Plan as a whole (Technical Clarifications).\30\ Finally, transportation 
conformity budgets for 2018 are presented in a supplemental SIP 
revision adopted July 23, 2015 and entitled ``Transportation Conformity 
Budgets for the San Joaquin Valley PM<INF>2.5</INF> SIP Plan 
Supplement.''
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    \28\ 2015 PM<INF>2.5</INF> Plan, ``Staff Report, ARB Review of 
San Joaquin Valley PM<INF>2.5</INF> State Implementation Plan,'' 
release date April 20, 2015, pp. 9, 17-22, 25-26, and 26-27, 
respectively.
    \29\ 2015 PM<INF>2.5</INF> Plan, ``Attainment Demonstration for 
the San Joaquin Valley 2015 PM<INF>2.5</INF> Plan for the Annual (15 
[micro]g/m\3\) and 24-hour (65 [micro]g/m\3\) Standards.''
    \30\ 2015 PM<INF>2.5</INF> Plan, ``Technical Clarifications to 
the 2015 San Joaquin Valley PM<INF>2.5</INF> State Implementation 
Plan.''
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    We present our evaluation of the 2015 PM<INF>2.5</INF> Plan in 
section V of this proposed rule. Given the overlap of some control and 
planning requirements between a PM<INF>2.5</INF> Serious area plan and 
a request for extension of the PM<INF>2.5</INF> Serious area attainment 
date, we generally address these requirements together rather than 
separately. For example, we address the BACM requirement for Serious 
area plans and the MSM requirement for extension requests together in 
section V.D. of this proposed rule. Similarly, we address the 
requirement for a Serious area attainment demonstration and the 
requirement to demonstrate attainment by the most expeditious 
alternative date practicable, for purposes of requesting an extension 
of the attainment date,

[[Page 6939]]

together in section V.E.5 of this proposed rule.

III. Completeness Review of the San Joaquin Valley 2015 
PM<INF>2.5</INF> Plan

    CAA sections 110(a)(1) and (2) and 110(l) require each state to 
provide reasonable public notice and opportunity for public hearing 
prior to the adoption and submission of a SIP or SIP revision to the 
EPA. To meet this requirement, every SIP submission should include 
evidence that adequate public notice was given and an opportunity for a 
public hearing was provided consistent with the EPA's implementing 
regulations in 40 CFR 51.102.
    Both the District and CARB satisfied applicable statutory and 
regulatory requirements for reasonable public notice and hearing prior 
to adoption and submission of the 2015 PM<INF>2.5</INF> Plan. The 
District conducted a public workshop, provided a public comment period, 
and held a public hearing prior to the adoption of the main SIP 
submission on April 16, 2015.\31\ CARB provided the required public 
notice and opportunity for public comment prior to its May 21, 2015 
public hearing and adoption of the main SIP submission.\32\ CARB then 
adopted its supplemental SIP submission pertaining to 2018 
transportation conformity motor vehicle emission budgets at its July 
23, 2015 Board meeting after reasonable public notice.\33\ Each 
submission includes proof of publication of notices for the respective 
public hearings. We find, therefore, that the 2015 PM<INF>2.5</INF> 
Plan meets the procedural requirements for public notice and hearing in 
CAA sections 110(a) and 110(l).
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    \31\ SJVUAPCD, ``Notice of Public Workshop [on] Draft Plan for 
the 1997 PM<INF>2.5</INF> Standard,'' March 2, 2015; SJVUAPCD, 
``Notice of Public Hearing [to] Adopt Proposed 2015 Plan for the 
1997 PM<INF>2.5</INF> Standard,'' March 17, 2015; and SJVUAPCD 
Governing Board Resolution 15-4-7A, ``In the Matter of Adopting the 
San Joaquin Valley Unified Air Pollution Control District 2015 Plan 
for the 1997 PM<INF>2.5</INF> Standard,'' April 16, 2015.
    \32\ CARB, ``Notice of Public Meeting to Consider Approval of 
the San Joaquin Valley PM<INF>2.5</INF> State Implementation Plan,'' 
April 20, 2015; and CARB Board Resolution 15-9, ``San Joaquin Valley 
PM<INF>2.5</INF> State Implementation Plan,'' May 21, 2015.
    \33\ CARB, ``Notice of Public Meeting to Consider the Approval 
of Transportation Conformity Budgets for the San Joaquin Valley 
PM<INF>2.5</INF> State Implementation Plan,'' June 19, 2015; and 
CARB Board Resolution 15-39, ``San Joaquin Valley PM<INF>2.5</INF> 
State Implementation Plan,'' July 23, 2015.
---------------------------------------------------------------------------

    CAA section 110(k)(1)(B) requires the EPA to determine whether a 
SIP submission is complete within 60 days of receipt. This section also 
provides that any plan that the EPA has not affirmatively determined to 
be complete or incomplete will become complete by operation of law six 
months after the date of submission. The EPA's SIP completeness 
criteria are found in 40 CFR part 51, Appendix V. The initial SIP 
submission, dated June 25, 2015, became complete by operation of law on 
December 25, 2015 and we find that the SIP submission pertaining to 
2018 transportation conformity motor vehicle emission budgets, dated 
August 13, 2015, satisfies the completeness criteria in 40 CFR part 51, 
appendix V.

IV. Clean Air Act Requirements for PM<INF>2.5</INF> Serious Area Plans

A. PM2.5 Serious Area Plan Requirements

    Upon reclassification of a Moderate nonattainment area as a Serious 
nonattainment area under subpart 4, the CAA requires the State to 
submit the following Serious area SIP elements: \34\
---------------------------------------------------------------------------

    \34\ 80 FR 18528, 18531 (April 7, 2015).
---------------------------------------------------------------------------

    1. A comprehensive, accurate, current inventory of actual emissions 
from all sources of PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors in 
the area (CAA section 172(c)(3));
    2. Provisions to assure that the best available control measures 
(BACM), including best available control technology (BACT), for the 
control of direct PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors 
shall be implemented no later than 4 years after the area is 
reclassified (CAA section 189(b)(1)(B));
    3. A demonstration (including air quality modeling) that the plan 
provides for attainment as expeditiously as practicable but no later 
than December 31, 2015, or where the State is seeking an extension of 
the attainment date under section 188(e), a demonstration that 
attainment by December 31, 2015 is impracticable and that the plan 
provides for attainment by the most expeditious alternative date 
practicable (CAA sections 188(c)(2) and 189(b)(1)(A));
    4. Plan provisions that require reasonable further progress (RFP) 
(CAA section 172(c)(2));
    5. Quantitative milestones which are to be achieved every 3 years 
until the area is redesignated attainment and which demonstrate RFP 
toward attainment by the applicable date (CAA section 189(c));
    6. Provisions to assure that control requirements applicable to 
major stationary sources of PM<INF>2.5</INF> also apply to major 
stationary sources of PM<INF>2.5</INF> precursors, except where the 
State demonstrates to the EPA's satisfaction that such sources do not 
contribute significantly to PM<INF>2.5</INF> levels that exceed the 
standard in the area (CAA section 189(e));
    7. Contingency measures to be implemented if the area fails to meet 
RFP or to attain by the applicable attainment date (CAA section 
172(c)(9)); and
    8. A revision to the nonattainment new source review (NSR) program 
to lower the applicable ``major stationary source'' \35\ thresholds 
from 100 tons per year (tpy) to 70 tpy (CAA section 189(b)(3)).
---------------------------------------------------------------------------

    \35\ For any Serious area, the terms ``major source'' and 
``major stationary source'' include any stationary source that emits 
or has the potential to emit at least 70 tons per year of 
PM<INF>10</INF> (CAA section 189(b)(3)).
---------------------------------------------------------------------------

    Serious area PM<INF>2.5</INF> plans must also satisfy the 
requirements for Moderate area plans in CAA section 189(a), to the 
extent those requirements have not already been satisfied in the 
Moderate area plan submitted for the area; the general requirements 
applicable to all SIP submissions under section 110 of the CAA; the 
requirement to provide necessary assurances that the implementing 
agencies have adequate personnel, funding and authority under section 
110(a)(2)(E); and the requirements concerning enforcement provisions in 
section 110(a)(2)(C).
    The EPA provided its preliminary views on the CAA's requirements 
for particulate matter plans under part D, title I of the Act in the 
following guidance documents: (1) ``State Implementation Plans; General 
Preamble for the Implementation of Title I of the Clean Air Act 
Amendments of 1990, 57 FR 13498 (April 16, 1992) (hereafter ``General 
Preamble''); (2) ``State Implementation Plans; General Preamble for the 
Implementation of Title I of the Clean Air Act Amendments of 1990; 
Supplemental,'' 57 FR 18070 (April 28, 1992) (hereafter 
``Supplement''); and (3) ``State Implementation Plans for Serious PM-10 
Nonattainment Areas, and Attainment Date Waivers for PM-10 
Nonattainment Areas Generally; Addendum to the General Preamble for the 
Implementation of Title I of the Clean Air Act Amendments of 1990,'' 59 
FR 41998 (August 16, 1994) (hereafter ``Addendum''). Additionally, in a 
proposed rule published March 23, 2015 (80 FR 15340), the EPA provided 
further interpretive guidance on the statutory SIP requirements that 
apply to areas designated nonattainment for the PM<INF>2.5</INF> 
standards (hereafter ``Proposed PM<INF>2.5</INF> Implementation 
Rule''). We discuss these preliminary interpretations of the Act as 
appropriate in our evaluation of the 2015 PM<INF>2.5</INF> Plan in 
section V of this proposed rule.

[[Page 6940]]

B. Implementation of Best Available Control Measures

    Section 189(b)(1)(B) of the Act requires for any serious 
PM<INF>2.5</INF> nonattainment area that the State submit provisions to 
assure that the best available control measures (BACM) for the control 
of PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors shall be 
implemented no later than four years after the date the area is 
reclassified as a serious area. The EPA defines BACM as, among other 
things, the maximum degree of emissions reduction achievable for a 
source or source category, which is determined on a case-by-case basis 
considering energy, environmental, and economic impacts.\36\ We 
generally consider BACM a control level that goes beyond existing RACM-
level controls, for example by expanding the use of RACM controls or by 
requiring preventative measures instead of remediation.\37\ Indeed, as 
implementation of BACM and BACT is required when a Moderate 
nonattainment area is reclassified as Serious due to its inability to 
attain the NAAQS through implementation of ``reasonable'' measures, it 
is logical that ``best'' control measures should represent a more 
stringent and potentially more costly level of control.\38\
---------------------------------------------------------------------------

    \36\ Addendum at 42010, 42013.
    \37\ Id. at 42011, 42013.
    \38\ Id. at 42009-42010.
---------------------------------------------------------------------------

    The EPA has historically provided an exemption from BACM and BACT 
for source categories that contribute only de minimis levels to ambient 
PM<INF>10</INF> concentrations in a Serious nonattainment area. The 
Addendum discusses the following steps for determining BACM:
    1. Develop a detailed emission inventory of the sources of 
PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors;
    2. Evaluate source category impacts;
    3. Evaluate alternative control techniques and their technological 
feasibility; and
    4. Evaluate the costs of control (i.e., economic feasibility).\39\
---------------------------------------------------------------------------

    \39\ Id. at 42012-42014.
---------------------------------------------------------------------------

    Once these analyses are complete, the State must use this 
information to develop enforceable control measures and submit them to 
the EPA for evaluation under CAA section 110. We use these steps as 
guidelines in our evaluation of the BACM measures and related analyses 
in the 2015 PM<INF>2.5</INF> Plan.

C. Implementation of Reasonably Available Control Measures

    When the EPA reclassifies a Moderate area to Serious under subpart 
4, the requirement to implement reasonably available control measures 
(RACM) in section 189(a)(1)(C) remains. Thus, a Serious area 
PM<INF>2.5</INF> plan must also provide for the implementation of RACM 
as expeditiously as practicable, to the extent that the RACM 
requirement has not been satisfied in the area's Moderate area 
plan.\40\
---------------------------------------------------------------------------

    \40\ EPA previously approved California's RACM demonstration for 
the 1997 PM<INF>2.5</INF> NAAQS in the SJV (76 FR 69896, November 9, 
2011). On May 20, 2015, the Ninth Circuit Court of Appeals remanded 
this final rule to EPA on the grounds that the California mobile 
source ``waiver measures'' upon which the plan relied were not 
federally enforceable components of the approved SIP. Committee for 
a Better Arvin v. EPA, 786 F.3d 1169 (9th Cir. 2015). On November 
12, 2015, the EPA proposed to approve the relevant waiver measures 
into the SIP and to thereby make them federally enforceable under 
the CAA. 80 FR 69915 (November 12, 2015). Final approval of these 
waiver measures would cure the deficiency in California's RACM 
demonstration for the 1997 PM<INF>2.5</INF> NAAQS in the SJV.
---------------------------------------------------------------------------

    However, the EPA does not normally conduct a separate evaluation to 
determine whether a Serious area plan's measures also meet the RACM 
requirements. As explained in the Addendum, we interpret the BACM 
requirement as generally subsuming the RACM requirement--i.e., if we 
determine that the measures are indeed the ``best available,'' we have 
necessarily concluded that they are ``reasonably available.''\41\ 
Therefore, a separate analysis to determine if the measures represent a 
RACM level of control is not necessary. A proposed approval of a Plan's 
provisions concerning implementation of BACM is also a proposed finding 
that the Plan provides for the implementation of RACM.
---------------------------------------------------------------------------

    \41\ Addendum at 42010.
---------------------------------------------------------------------------

D. Extension of the Serious Area Attainment Date Beyond 2015

    Under section 188(e) of the Act, a state may apply to the EPA for a 
single extension of the Serious area attainment date by up to 5 years, 
which the EPA may grant if the State satisfies certain conditions. 
Before the EPA may extend the attainment date for a Serious area under 
section 188(e), the State must: (1) Apply for an extension of the 
attainment date beyond the statutory attainment date; (2) demonstrate 
that attainment by the statutory attainment date is impracticable; (3) 
have complied with all requirements and commitments pertaining to the 
area in the implementation plan; (4) demonstrate to the satisfaction of 
the Administrator that the plan for the area includes the ``most 
stringent measures'' that are included in the implementation plan of 
any State or are achieved in practice in any State, and can feasibly be 
implemented in the area; and (5) submit a demonstration of attainment 
by the most expeditious alternative date practicable.\42\
---------------------------------------------------------------------------

    \42\ For a discussion of EPA's interpretation of the 
requirements of section 188(e), see Addendum at 42002 (August 16, 
1994); 65 FR 19964 (April 13, 2000) (proposed action on 
PM<INF>10</INF> Plan for Maricopa County, Arizona); 66 FR 50252 
(October 2, 2001) (proposed action on PM<INF>10</INF> Plan for 
Maricopa County, Arizona); 67 FR 48718 (July 25, 2002) (final action 
on PM<INF>10</INF> 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 PM<INF>10</INF> Plan for Maricopa County, 
Arizona but generally upholding EPA's interpretation of CAA section 
188(e)).
---------------------------------------------------------------------------

    In addition to establishing these preconditions for an extension of 
the Serious area attainment date, section 188(e) provides that the EPA 
may consider a number of factors in determining whether to grant an 
extension and the appropriate length of time for any such extension. 
These factors are: (1) The nature and extent of nonattainment in the 
area, (2) the types and numbers of sources or other emitting activities 
in the area (including the influence of uncontrollable natural sources 
and trans-boundary emissions from foreign countries), (3) the 
population exposed to concentrations in excess of the standard in the 
area, (4) the presence and concentrations of potentially toxic 
substances in the mix of particulate emissions in the area, and (5) the 
technological and economic feasibility of various control measures.\43\ 
Notably, neither the statutory requirements nor the discretionary 
factors identified in section 188(e) include the specific ambient air 
quality conditions in section 188(d)(2), which must be met for an area 
to qualify for an extension of a Moderate area attainment date.
---------------------------------------------------------------------------

    \43\ CAA section 188(e).
---------------------------------------------------------------------------

    The EPA has previously interpreted section 188(e) in approving an 
extension of the PM<INF>10</INF> Serious area attainment date for the 
Phoenix Metropolitan area in Maricopa County, Arizona.\44\ We propose 
to generally follow the steps provided in that rulemaking action for 
addressing the statutory requirements for an extension of the Serious 
area attainment date under section 188(e) as described below.
---------------------------------------------------------------------------

    \44\ See 65 FR 19964 (April 13, 2000) (proposed action on 
Maricopa County Serious Area Plan, annual PM<INF>10</INF> standard); 
66 FR 50252 (October 2, 2001) (proposed action on Maricopa County 
Serious Area Plan, 24-hour PM<INF>10</INF> standard); and 67 FR 
48718 (July 25, 2002) (final action on Maricopa County Serious Area 
Plan).
---------------------------------------------------------------------------

    Step 1: Demonstrate that attainment by the statutory Serious area 
attainment date is impracticable.
    Section 188(e) authorizes the EPA to grant a state request for an 
extension of the Serious area attainment date if,

[[Page 6941]]

among other things, attainment by the date established under section 
188(c) would be impracticable. In order to demonstrate 
impracticability, the plan must show that the implementation of BACM 
and BACT on relevant source categories will not bring the area into 
attainment by the statutory Serious area attainment date. For the SJV, 
the Serious area attainment date under section 188(c)(2) is December 
31, 2015.\45\ BACM, including BACT, is the required level of control 
for serious areas that must be in place before the Serious area 
attainment date. Therefore, we interpret the Act as requiring that a 
state provide for at least the implementation of BACM, including BACT, 
before it can claim impracticability of attainment by the statutory 
deadline. The statutory provision for demonstrating impracticability 
requires that the demonstration be based on air quality modeling.\46\
---------------------------------------------------------------------------

    \45\ Under CAA section 188(c)(2), the attainment date for a 
Serious area ``shall be as expeditiously as practicable but no later 
than the end of the tenth calendar year beginning after the area's 
designation as nonattainment . . . .'' EPA designated the SJV area 
as nonattainment for the 1997 PM<INF>2.5</INF> standards effective 
April 5, 2005 (70 FR 944, 956-957, January 5, 2005). Therefore, the 
latest permissible attainment date under section 188(c)(2), for 
purposes of the 1997 PM<INF>2.5</INF> standards in this area, is 
December 31, 2015.
    \46\ CAA section 189(b)(1)(A).
---------------------------------------------------------------------------

    This interpretation parallels our interpretation of the 
impracticability option for Moderate PM<INF>10</INF> nonattainment 
areas in section 189(a)(1)(B), under which implementation of a RACM/
RACT control strategy, at a minimum, is a prerequisite for approval of 
a Moderate area plan demonstrating impracticability of attainment by 
the Moderate area attainment date.\47\
---------------------------------------------------------------------------

    \47\ General Preamble at 13544; see also 65 FR 19964, 19968 
(April 13, 2000).
---------------------------------------------------------------------------

    Step 2: Comply with all requirements and commitments in the 
applicable implementation plan.
    A second precondition for an extension of the Serious area 
attainment under section 188(e) is a showing that the State has 
complied with all requirements and commitments pertaining to that area 
in the implementation plan. We interpret this criterion to mean that 
the State has implemented the control measures and commitments in the 
SIP revisions it has submitted to address the applicable requirements 
in CAA sections 172 and 189 for PM<INF>2.5</INF> nonattainment areas. 
For a Serious area attainment date extension request being submitted 
simultaneously with the initial Serious area attainment plan for the 
area, the EPA proposes to read section 188(e) not to require the area 
to have a fully approved Moderate area attainment plan and to allow for 
extension of the attainment date if the area has complied with all 
Moderate area requirements and commitments pertaining to that area in 
the State's submitted Moderate area implementation plan. This 
interpretation is based on the plain language of section 188(e), which 
requires the State to comply with all requirements and commitments 
pertaining to the area in the implementation plan.\48\
---------------------------------------------------------------------------

    \48\ The Ninth Circuit Court of Appeals upheld this 
interpretation of section 188(e) in Vigil v. Leavitt, 366 F.3d 1025, 
amended at 381 F.3d 826 (9th Cir. 2004).
---------------------------------------------------------------------------

    Step 3: Demonstrate the inclusion of the most stringent measures.
    A third precondition for an extension of the Serious area 
attainment under section 188(e) is for the State to demonstrate to the 
satisfaction of the Administrator that the plan for the area includes 
the most stringent measures that are included in the implementation 
plan of any state, or are achieved in practice in any state, and can 
feasibly be implemented in the area. The EPA has interpreted the term 
``most stringent measure'' (MSM) to mean the maximum degree of emission 
reduction that has been required or achieved from a source or source 
category in any other attainment plan or in practice in any other state 
and that can feasibly be implemented in the area seeking the 
extension.\49\ The Act does not specify an implementation deadline for 
MSM. Because the clear intent of section 188(e) is to minimize the 
length of any attainment date extension, we propose that the 
implementation of MSM should be as expeditiously as practicable.
---------------------------------------------------------------------------

    \49\ 65 FR 19964, 19968 (April 13, 2000); see also Addendum at 
42010.
---------------------------------------------------------------------------

    An MSM demonstration should follow a process similar to a BACM 
demonstration, but with one additional step, as follows:
    1. Develop a detailed emission inventory of the sources of 
PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors;
    2. Evaluate source category impacts;
    3. Identify the potentially most stringent measures in other 
implementation plans or used in practice in other states for each 
relevant source category and, for each measure, determine their 
technological and economic feasibility in the nonattainment area;
    4. Compare the potential MSM for each relevant source category to 
the measures, if any, already adopted for that source category in the 
Serious nonattainment area to determine whether such potential MSM 
would further reduce emissions; and
    5. Provide for the adoption and expeditious implementation of any 
MSM that is more stringent than existing measures or, in lieu of 
adoption, provide a reasoned justification for rejecting the potential 
MSM (i.e., provide an explanation as to why such measures cannot 
feasibly be implemented in the area).\50\
---------------------------------------------------------------------------

    \50\ 65 FR 19964, 19968 (April 13, 2000); see also Proposed 
PM<INF>2.5</INF> Implementation Rule at 15420 (March 23, 2015).
---------------------------------------------------------------------------

    The level of control required under the MSM standard may depend on 
how well other areas have chosen to control their sources. If a source 
category has not been well controlled in other areas then MSM could 
theoretically result in a low level of control. This contrasts with 
BACM which is determined independently of what other areas have done 
and depends only on what is the best level of control feasible for an 
area.\51\ On the other hand, given the strategy in the nonattainment 
provisions of the Act to offset longer attainment timeframes with more 
stringent emission control requirements, we interpret the MSM provision 
to assure that it results in additional controls beyond the set of 
measures adopted as BACM. Two ways to do this are (1) to require that 
more sources and source categories be subject to MSM analysis than to 
BACM analysis, that is, by expanding the applicability provisions in 
the MSM control requirements to cover more sources, and (2) to require 
reanalysis of any measures adopted in other areas that were rejected 
during the BACM analysis because they could not be implemented by the 
BACM implementation deadline to see if they are now feasible for the 
area given the longer attainment timeframe.\52\
---------------------------------------------------------------------------

    \51\ Id.
    \52\ 65 FR 19964, 19968-19969.
---------------------------------------------------------------------------

    Notably, the ``to the satisfaction of the Administrator'' qualifier 
on the MSM requirement indicates that Congress granted the EPA 
considerable discretion in determining whether a plan in fact includes 
MSM, recognizing that the overall intent of section 188(e) is that we 
grant as short an extension as practicable. For this reason, the EPA 
will apply greater scrutiny to the evaluation of MSM for source 
categories that contribute the most to the PM<INF>2.5</INF> problem in 
the SJV and less scrutiny to source categories that contribute little 
to the PM<INF>2.5</INF> problem.
    Step 4: Demonstrate attainment by the most expeditious alternative 
date practicable.
    Section 189(b)(1)(A) requires that the Serious area plan for the 
SJV area

[[Page 6942]]

demonstrate attainment, using air quality modeling, by the most 
expeditious date practicable after December 31, 2015. Because the 1997 
annual and 24-hour PM<INF>2.5</INF> standards are independent 
standards, section 189(b)(1)(A) requires a demonstration of attainment 
by the most expeditious date practicable for each standard.\53\
---------------------------------------------------------------------------

    \53\ Ober v. EPA, 84 F.3d 304 (9th Cir. 1996) (noting that the 
CAA requires independent treatment of the annual and 24-hour 
PM<INF>10</INF> standards in an implementation plan).
---------------------------------------------------------------------------

    Evaluation of a modeled attainment demonstration consists of two 
parts: Evaluation of the technical adequacy of the modeling itself and 
evaluation of the control measures that are relied on to demonstrate 
attainment. The EPA's determination of whether the plan provides for 
attainment by the most expeditious date practicable depends on whether 
the plan provides for implementation of BACM and BACT no later than the 
statutory implementation deadline, MSM as expeditiously as practicable, 
and any other technologically and economically feasible measures that 
will result in attainment as expeditiously as practicable.
    Step 5: Apply for an attainment date extension.
    Finally, the State must apply in writing to the EPA for an 
extension of a Serious area attainment date, and this request must 
accompany the modeled attainment demonstration showing attainment by 
the most expeditious alternative date practicable. Additionally, the 
State must provide the public reasonable notice and opportunity for a 
public hearing on the attainment date extension request before 
submitting it to the EPA, in accordance with the requirements for SIP 
revisions in CAA section 110.

V. Review of the San Joaquin Valley PM<INF>2.5</INF> Serious Area Plan 
and Extension Application

A. Emissions Inventory

1. Requirements for Emissions Inventories
    CAA section 172(c)(3) requires that each SIP include a 
``comprehensive, accurate, current inventory of actual emissions from 
all sources of the relevant pollutant or pollutants in [the] area . . . 
.'' By requiring an accounting of actual emissions from all sources of 
the relevant pollutants in the area, this section provides for the base 
year inventory to include all emissions that contribute to the 
formation of a particular NAAQS pollutant. For the 1997 
PM<INF>2.5</INF> standards, this includes direct PM<INF>2.5</INF> as 
well as the main chemical precursors to the formation of secondary 
PM<INF>2.5</INF>: NO<INF>X</INF>, sulfur dioxide (SO<INF>2</INF>), 
volatile organic compounds (VOC), and ammonia (NH<INF>3</INF>). Primary 
PM<INF>2.5</INF> includes condensable and filterable particulate 
matter.
    A state must include in its SIP submission documentation explaining 
how the emissions data were calculated. In estimating mobile source 
emissions, a state should use the latest emissions models and planning 
assumptions available at the time the SIP is developed. States are also 
required to use the EPA's Compilation of Air Pollutant Emission Factors 
(AP-42) \54\ road dust method for calculating re-entrained road dust 
emissions from paved roads.\55\ The latest EPA-approved version of 
California's mobile source emission factor model is EMFAC2014.\56\
---------------------------------------------------------------------------

    \54\ EPA released an update to AP-42 in January 2011, which 
revised the equation for estimating paved road dust emissions based 
on an updated data regression that included new emission tests 
results.
    \55\ 76 FR 6328 (February 4, 2011).
    \56\ 80 FR 77337 (December 14, 2015).
---------------------------------------------------------------------------

    In addition to the base year inventory submitted to meet the 
requirements of CAA section 172(c)(3), the State must also submit 
future ``baseline inventories'' for the projected attainment year and 
each reasonable further progress (RFP) milestone year, and any other 
year of significance for meeting applicable CAA requirements.\57\ By 
``baseline inventories'' (also referred to as ``projected baseline 
inventories''), we mean projected emissions inventories for future 
years that account for, among other things, the ongoing effects of 
economic growth and adopted emissions control requirements. The SIP 
should include documentation to explain how the emissions projections 
were calculated.
---------------------------------------------------------------------------

    \57\ 40 CFR 51.1007(a), 51.1008(b), and 51.1009(f); see also 
U.S. EPA, ``Emissions Inventory Guidance for Implementation of Ozone 
[and Particulate Matter] National Ambient Air Quality Standards 
(NAAQS) and Regional Haze Regulations,'' available at http://www.epa.gov/sites/production/files/2014-10/documents/2014revisedeiguidance_0.pdf.
---------------------------------------------------------------------------

2. Emissions Inventories in the 2015 PM<INF>2.5</INF> Plan
    The planning inventories for direct PM<INF>2.5</INF> and all 
PM<INF>2.5</INF> precursors (NO<INF>X</INF>, SO<INF>X</INF>, VOC, and 
ammonia) for the SJV PM<INF>2.5</INF> nonattainment area together with 
documentation for the inventories are found in SJV Appendix B of the 
2015 PM<INF>2.5</INF> Plan. Annual average inventories and winter daily 
average inventories, representing conditions in the period November 
through April, are provided for the base year of 2012 and each baseline 
year from 2013 to 2020. The winter daily average inventory is useful to 
evaluate sources of emissions during the portion of the year when the 
vast majority of exceedances of the 1997 24-hour PM<INF>2.5</INF> NAAQS 
occur. Baseline inventories reflect all control measures adopted prior 
to January 2012. Growth factors used to project these baseline 
inventories are derived from data obtained from a number of sources 
such as the California Energy Commission (CEC), the Division of Oil, 
Gas, and Geothermal Resources (DOGGR), and the California Department of 
Finance, as well as studies commissioned by the SJV's metropolitan 
planning organizations.\58\
---------------------------------------------------------------------------

    \58\ 2015 PM<INF>2.5</INF> Plan, SJV Appendix B, pp. B-23 to B-
29.
---------------------------------------------------------------------------

    Each inventory includes emissions from point, area, on-road, and 
non-road sources. The inventories use EMFAC2014 for estimating on-road 
motor vehicle emissions.\59\ Re-entrained paved road dust emissions 
were calculated using the EPA's AP-42 road dust methodology.\60\
---------------------------------------------------------------------------

    \59\ Id. at B-31.
    \60\ Id. at B-27.
---------------------------------------------------------------------------

    Tables 1 and 2 provide a summary of the annual average and winter 
daily average inventories of direct PM<INF>2.5</INF> and 
PM<INF>2.5</INF> precursors for the base year of 2012. The District 
provides its reasons for selecting 2012 as the base year in Appendix B 
of the Plan.\61\ These inventories provide the basis for the control 
measure analysis and the RFP and attainment demonstrations in the 2015 
PM<INF>2.5</INF> Plan.
---------------------------------------------------------------------------

    \61\ Id. At B-20, B-21.

[[Page 6943]]



  Table 1--San Joaquin Valley Annual Average Emissions Inventory for Direct PM2.5 and PM2.5 Precursors for the
                                                 2012 Base Year
                                                   [Tons/day]
----------------------------------------------------------------------------------------------------------------
                                   Direct PM2.5         NOX             SOX             VOC           Ammonia
----------------------------------------------------------------------------------------------------------------
Stationary Sources..............             8.8            38.3             6.9            99.2            13.6
Area Sources....................            44.1             8.2             0.3           152.1           311.2
On-Road Mobile Sources..........             7.3           198.0             0.6            54.0             4.7
Off-Road Mobile Sources.........             5.9            87.7             0.2            35.3             0.0
    Total.......................            66.0           332.2             8.1           340.7           329.5
----------------------------------------------------------------------------------------------------------------
Source: 2015 PM2.5 Plan, Appendix B, Tables B-1 to B-5.


 Table 2--San Joaquin Valley Winter Daily Average Emissions Inventory for Direct PM2.5 and PM2.5 Precursors for
                                               the 2012 Base Year
                                                   [Tons/day]
----------------------------------------------------------------------------------------------------------------
                                   Direct PM2.5         NOX             SOX             VOC           Ammonia
----------------------------------------------------------------------------------------------------------------
Stationary Sources..............             8.5            34.6             6.6            98.7            13.5
Area Sources....................            40.7            11.7             0.5           156.5           291.8
On-Road Mobile Sources..........             7.3           204.1             0.6            55.6             4.7
Off-Road Mobile Sources.........             4.6            68.0             0.2            26.8             0.0
    Total.......................            61.0           318.5             7.9           337.5           310.0
----------------------------------------------------------------------------------------------------------------
Source: 2015 PM2.5 Plan, Appendix B, Tables B-1 to B-5.

3. EPA's Evaluation and Proposed Action
    The inventories in the 2015 PM<INF>2.5</INF> Plan are based on the 
most current and accurate information available to the State and 
District at the time the Plan and its inventories were being developed 
in 2014 and 2015, including the latest version of California's mobile 
source emissions model, EMFAC2014.\62\ The inventories comprehensively 
address all source categories in the SJV and were developed consistent 
with the EPA's inventory guidance. For these reasons, we are proposing 
to approve the 2012 base year emissions inventory in the 2015 
PM<INF>2.5</INF> Plan as meeting the requirements of CAA section 
172(c)(3). We are also proposing to find that the baseline inventories 
in the Plan provide an adequate basis for the BACM, MSM, 
impracticability, RFP, and attainment demonstrations in the 2015 
PM<INF>2.5</INF> Plan.
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    \62\ CARB submitted the EMFAC2014 model to the EPA on May 21, 
2015 and EPA recently approved that model for use in California 
SIPs. 80 FR 77337 (December 14, 2015).
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B. Adequate Monitoring Network

    We discuss the adequacy of the monitoring network in this preamble 
to support our finding that the plan appropriately evaluates the 
PM<INF>2.5</INF> challenges in the San Joaquin Valley. Reliable ambient 
data is necessary to validate the base year air quality modeling which 
in turn is necessary to assure sound attainment demonstrations.
    Section 110(a)(2)(B)(i) of the CAA requires states to establish and 
operate air monitoring networks to compile data on ambient air quality 
for all criteria pollutants. Our regulations in 40 CFR part 58 
establish specific requirements for operating air quality surveillance 
networks to measure ambient concentrations of PM<INF>2.5</INF>, 
including requirements for measurement methods, network design, quality 
assurance procedures, and in the case of large urban areas, the minimum 
number of monitoring sites designated as State and Local Air Monitoring 
Stations (SLAMS). A good spatial distribution of sites, correct siting, 
and quality-assured and quality-controlled data are the most important 
factors we consider when evaluating the monitoring network for air 
quality modeling.
    Under 40 CFR part 58, states are required to submit Annual Network 
Plans (ANPs) for ambient air monitoring networks for approval by the 
EPA. The most recent ANP, entitled ``2014 Air Monitoring Network 
Plan,'' summarizes the state of the ambient air monitoring network in 
the San Joaquin Valley as it operated from January 2013 through May 
2014.\63\ During this time, there were 20 monitoring sites operated by 
either the District or CARB that collected PM<INF>2.5</INF> data, 
including 14 monitors designated as SLAMS, ten monitors designated as 
special purpose monitors (SPMs), four supplemental speciation monitors, 
and eight non-regulatory monitors.\64\ On June 16, 2015, the EPA 
approved those portions of the State's and District's 2014 Air 
Monitoring Network Plan that pertain to the adequacy of the network for 
PM<INF>2.5</INF> monitoring purposes.\65\
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    \63\ SJVAPCD, ``2014 Air Monitoring Network Plan,'' January 28, 
2015.
    \64\ Id., Table 17, p. 25 and Table 19, p. 27.
    \65\ Letter dated June 16, 2015, from Meredith Kurpius, Manager, 
EPA Region 9, Air Quality Analysis Office, to Sheraz Gill, Director 
of Strategies and Incentives, SJVUAPCD.
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    Similarly, the District's previous ANP, entitled ``Annual Air 
Monitoring Network Plan, June 25, 2013,'' summarizes the state of the 
ambient air monitoring network in the San Joaquin Valley as it operated 
from January 2012 through March 2013.\66\ During this time, there were 
21 monitoring sites operated by either the District or CARB that 
collected PM<INF>2.5</INF> data, including 14 monitors designated as 
SLAMS, 12 monitors designated as special purpose monitors (SPMs), two 
supplemental speciation monitors, and eight non-regulatory 
monitors.\67\ On May 8, 2014, the EPA approved those portions of the 
State's and District's 2014 Air Monitoring Network Plan that pertain to 
the adequacy of the network for PM<INF>2.5</INF> monitoring 
purposes.\68\
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    \66\ SJVAPCD, ``Annual Air Monitoring Network Plan,'' June 25, 
2013.
    \67\ SJVAPCD, ``Annual Air Monitoring Network Plan,'' June 25, 
2013, Tables 15-17, pp. 25-32.
    \68\ Letter dated May 8, 2014, from Meredith Kurpius, Manager, 
EPA Region 9, Air Quality Analysis Office, to Sheraz Gill, Director 
of Strategies and Incentives, SJVUAPCD.
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    In sum, the PM<INF>2.5</INF> monitoring network operated by the 
District and CARB from January 2012 through May 2014 is adequate to 
support the air quality modeling in the 2015 PM<INF>2.5</INF> Plan.

[[Page 6944]]

C. PM<INF>2.5</INF> Precursors

1. Requirements for the Control of PM<INF>2.5</INF> Precursors
    The composition of PM<INF>2.5</INF> is complex and highly variable 
due in part to the large contribution of secondary PM<INF>2.5</INF> 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 
SO<INF>2</INF>, NO<INF>X</INF>, VOC, and ammonia to PM<INF>2.5</INF>, 
making them precursors to PM<INF>2.5</INF>.\69\ Formation of secondary 
PM<INF>2.5</INF> may also depend on atmospheric conditions, including 
solar radiation, temperature, and relative humidity, and the 
interactions of precursors with preexisting particles and with cloud or 
fog droplets.\70\
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    \69\ EPA, Air Quality Criteria for Particulate Matter (EPA/600/
P-99/002aF, October 2004), Chapter 3.
    \70\ EPA, Regulatory Impact Analysis for the Final Revisions to 
the National Ambient Air Quality Standards for Particulate Matter 
(EPA/452/R-12-005, December 2012), p. 2-1.
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    The 2007 PM<INF>2.5</INF> Implementation Rule contained rebuttable 
presumptions concerning the four PM<INF>2.5</INF> 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 SO<INF>2</INF> and NO<INF>X</INF> 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 . . . PM<INF>2.5</INF> 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 
PM<INF>2.5</INF> concentrations in the nonattainment area.\71\
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    \71\ 40 CFR 51.1002(c)(3), (4). See also 2007 PM<INF>2.5</INF> 
Implementation Rule, 72 FR 20586 at 20589-97 (April 25, 2007).
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    In NRDC, however, the DC Circuit remanded the EPA's 2007 
PM<INF>2.5</INF> Implementation Rule in its entirety, including the 
presumptions concerning VOC and ammonia in 40 CFR 51.1002.\72\ Although 
the court expressly declined to decide the specific challenge to these 
presumptions concerning precursors,\73\ the court cited CAA section 
189(e) \74\ to support its observation that ``[a]mmonia is a precursor 
to fine particulate matter, making it a precursor to both 
PM<INF>2.5</INF> and PM<INF>10</INF>'' and that ``[f]or a 
PM<INF>10</INF> nonattainment area governed by subpart 4, a precursor 
is presumptively regulated.'' \75\ Consistent with the NRDC decision, 
the EPA now interprets the Act to require that under subpart 4, a state 
must evaluate all PM<INF>2.5</INF> precursors for regulation unless, 
for any given PM<INF>2.5</INF> precursor, it demonstrates to the 
Administrator's satisfaction that such precursor does not contribute 
significantly to PM<INF>2.5</INF> levels which exceed the NAAQS in the 
nonattainment area.
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    \72\ NRDC v. EPA, 706 F.3d 428 (D.C. Cir. 2013).
    \73\ Id. at 437, n. 10.
    \74\ Section 189(e) of the CAA states that ``[t]he control 
requirements applicable under plans in effect under this part for 
major stationary sources of PM<INF>10</INF> shall also apply to 
major stationary sources of PM<INF>10</INF> precursors, except where 
the Administrator determines that such sources do not contribute 
significantly to PM<INF>10</INF> levels which exceed the standard in 
the area.''
    \75\ 706 F.3d at 436, n. 7 (D.C. Cir. 2013).
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    The provisions of subpart 4 do not define the term ``precursor'' 
for purposes of PM<INF>2.5</INF>, 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 
SO<INF>2</INF>, NO<INF>X</INF>, VOC, and ammonia as precursors to the 
formation of PM<INF>2.5</INF>. Accordingly, the attainment plan 
requirements of subpart 4 apply to emissions of all four precursor 
pollutants and direct PM<INF>2.5</INF> 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 PM<INF>10</INF> also apply to 
major stationary sources of PM<INF>10</INF> precursors, except where 
the Administrator determines that such sources do not contribute 
significantly to PM<INF>10</INF> levels that exceed the standard in the 
area. Section 189(e) contains the only express exception to the control 
requirements under subpart 4 (e.g., requirements for reasonably 
available control measures (RACM) and reasonably available control 
technology (RACT), best available control measures (BACM) and best 
available control technology (BACT), most stringent measures (MSM), and 
new source review (NSR)) for sources of direct PM<INF>2.5</INF> and 
PM<INF>2.5</INF> precursor emissions. Although section 189(e) 
explicitly addresses only major stationary sources, the EPA interprets 
the Act as authorizing it also to determine, under appropriate 
circumstances, that regulation of specific PM<INF>2.5</INF> 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 PM<INF>10</INF> precursors area-wide under CAA section 
172(c)(1) and subpart 4,\76\ a state may demonstrate in a SIP 
submission that control of a certain precursor pollutant is not 
necessary in light of its insignificant contribution to ambient 
PM<INF>10</INF> levels in the nonattainment area.\77\
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    \76\ General Preamble, 57 FR 13498 at 13539-42 (April 16, 1992).
    \77\ Courts have upheld this approach to the requirements of 
subpart 4 for PM<INF>10</INF>. See, e.g., Assoc. of Irritated 
Residents v. EPA, et al., 423 F.3d 989 (9th Cir. 2005).
---------------------------------------------------------------------------

    We are evaluating the 2015 PM<INF>2.5</INF> Plan in accordance with 
the presumption embodied within subpart 4 that all PM<INF>2.5</INF> 
precursors must be addressed in the State's evaluation of potential 
control measures, unless the State adequately demonstrates that 
emissions of a particular precursor or precursors do not contribute 
significantly to ambient PM<INF>2.5</INF> levels that exceed the 
PM<INF>2.5</INF> NAAQS in the nonattainment area. In reviewing any 
determination by the State to exclude a PM<INF>2.5</INF> precursor from 
the required evaluation of potential control measures, we consider both 
the magnitude of the precursor's contribution to ambient 
PM<INF>2.5</INF> concentrations in the nonattainment area and the 
sensitivity of ambient PM<INF>2.5</INF> concentrations in the area to 
reductions in emissions of that precursor.
2. Evaluation of Precursors in the 2015 PM<INF>2.5</INF> Plan
    In the 2015 PM<INF>2.5</INF> Plan, the State and District identify 
NO<INF>X</INF> and SO<INF>X</INF> as the precursors that are the focus 
of its control strategy to attain the 1997 PM<INF>2.5</INF> standards 
in the San Joaquin Valley.\78\ Although no technical demonstration is 
necessary to support a conclusion consistent with the statutory 
requirement to regulate specific PM<INF>2.5</INF> precursors under 
subpart 4, the 2015 PM<INF>2.5</INF> Plan nevertheless provides 
supporting evidence describing the effectiveness of NO<INF>X</INF> and 
SO<INF>X</INF> emission controls.\79\ By contrast, the 2015 
PM<INF>2.5</INF> Plan includes statements that further

[[Page 6945]]

reductions in VOC and ammonia emissions would not contribute to 
attainment of the 1997 PM<INF>2.5</INF> NAAQS in the area \80\ and 
provides CARB's and SJVUAPCD`s analyses to support these positions.
---------------------------------------------------------------------------

    \78\ This identification is made in the 2015 PM<INF>2.5</INF> 
Plan, WOEA, p. A-3. See also Chapter 2 (``PM<INF>2.5</INF> Trends 
and Challenges in the San Joaquin Valley''), for more regarding the 
State and District's analysis that NO<INF>X</INF> is a significant 
precursor (p. 2-8), and that VOC and ammonia are insignificant 
precursors (pp. 2-19 and 2-27, respectively).
    \79\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, p. 2-24 and Figure 
2-19, p. 2-26 (for NO<INF>X</INF>) and SJV Appendix A, p. A-47 (for 
SO<INF>X</INF>).
    \80\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, p. 2-19.
---------------------------------------------------------------------------

    CARB and the SJVUAPCD base these conclusions on various air quality 
monitoring and modeling studies, modeling done by CARB for the 2008 
PM<INF>2.5</INF> Plan and for the 2012 plan for attaining the 2006 
PM<INF>2.5</INF> standard in the SJV (``2012 PM<INF>2.5</INF> Plan''), 
and other technical information. We discuss below the technical bases 
provided in the 2015 PM<INF>2.5</INF> Plan to support these positions 
with respect to SO<INF>2</INF>, NO<INF>X</INF>, VOC, and ammonia, as 
well as EPA's analyses of this information. For more detail on EPA's 
analyses, please refer to section II of our ``General Technical Support 
Document for EPA's Proposed Rule on the 2015 PM<INF>2.5</INF> Plan for 
the San Joaquin Valley for the 1997 PM<INF>2.5</INF> NAAQS,'' January 
2016 (``General TSD'').
a. SO<INF>2</INF>
    The 2015 PM<INF>2.5</INF> Plan recognizes that emissions of 
SO<INF>2</INF> contribute significantly to ambient PM<INF>2.5</INF> 
levels in the San Joaquin Valley, and that ambient PM<INF>2.5</INF> 
concentrations are sensitive to reductions in SO<INF>2</INF>. It shows 
the measured contribution of SO<INF>2</INF> emissions to ambient 
PM<INF>2.5</INF> concentrations in pie charts portraying the 
contribution of various pollutant species. For 2010-2012, depending on 
location, the three-year annual average PM<INF>2.5</INF> chemical 
composition was 11-14% ammonium sulfate, while for 2011-2013, the 
three-year average high day PM<INF>2.5</INF> chemical composition was 
4-6% ammonium sulfate.\81\ The Plan further describes the formation of 
ammonium sulfate as SO<INF>X</INF>-limited, given that ammonia is about 
80 times more abundant than SO<INF>X</INF> for both annual and winter 
average emission inventories.\82\ The ammonium sulfate contribution 
levels are substantial, particularly with respect to the annual average 
concentration, although smaller than the contributions of some other 
PM<INF>2.5</INF> components (i.e., ammonium nitrate and organic 
matter).
---------------------------------------------------------------------------

    \81\ 2015 PM<INF>2.5</INF> Plan, WOEA, Figures 6 and 7, 
respectively, p. A-16. See also 2015 PM<INF>2.5</INF> Plan, Appendix 
F, Figure F-2, pp. F-8 to F-9, which shows how ammonium sulfate has 
decreased slightly at three of the four monitoring sites from the 
2004-2006 period to the 2011-2013 period.
    \82\ 2015 PM<INF>2.5</INF> Plan, WOEA, p. A-41. This is on a 
molar or mass-equivalent basis: there are 80 times as many ammonia 
molecules emitted as would be required to combine with all the 
emitted SO<INF>2</INF> molecules to form ammonium sulfate, 
accounting for the emissions in tons per day, the molecular masses, 
and the chemical formula for ammonium sulfate.
---------------------------------------------------------------------------

    Ambient PM<INF>2.5</INF> sensitivity to reductions of 
SO<INF>2</INF> emissions is also presented in the 2015 PM<INF>2.5</INF> 
Plan in the form of modeling results. The results from the sensitivity 
modeling are cited and discussed below in the NO<INF>X</INF> 
subsection. The 2015 PM<INF>2.5</INF> Plan infers from the modeling 
that there is an ambient PM<INF>2.5</INF> concentration decrease of 
0.08 [micro]g/m\3\ at the projected design value monitoring site in 
2019 (Bakersfield-California) per ton of SO<INF>2</INF> reduction in 
the SJV area.\83\ While the 2019 winter average emissions inventory for 
SO<INF>X</INF> (7.6 tpd) is much smaller than that for NO<INF>X</INF> 
(208.0 tpd) in the SJV, the 0.08 [micro]g/m\3\ PM<INF>2.5</INF> 
decrease per ton of emissions reduction is the same for SO<INF>2</INF> 
as it is for NO<INF>X</INF>.\84\ Even though the relatively small 
SO<INF>2</INF> contribution to ambient PM<INF>2.5</INF> concentrations 
may leave less scope for reductions, the sensitivity of ambient 
PM<INF>2.5</INF> to SO<INF>2</INF> emission reductions indicates that 
SO<INF>2</INF> emissions contribute significantly to PM<INF>2.5</INF> 
levels above the standards in the SJV area.
---------------------------------------------------------------------------

    \83\ 2015 PM<INF>2.5</INF> Plan, WOEA, p. A-27.
    \84\ Id. See also, 2015 PM<INF>2.5</INF> Plan, Appendix B, pp. 
B-8 and B-11.
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    Based on the technical analyses provided in the Plan, the EPA 
agrees with the State's and District's conclusion that SO<INF>2</INF> 
controls must be included in the evaluation of potential control 
measures for the 1997 PM<INF>2.5</INF> standards in the SJV, consistent 
with the requirements of subpart 4.
b. NO<INF>X</INF>
    The 2015 PM<INF>2.5</INF> Plan recognizes that emissions of 
NO<INF>X</INF> contribute significantly to ambient PM<INF>2.5</INF> 
levels in the San Joaquin Valley, and that ambient PM<INF>2.5</INF> 
concentrations are sensitive to reductions in NO<INF>X</INF>. The Plan 
discusses NO<INF>X</INF> in conjunction with ammonia, because these 
precursors react together to create ammonium nitrate, the largest 
component of ambient PM<INF>2.5</INF> particles by species in the 
SJV.\85\ The chemical products of ammonia and NO<INF>X</INF> (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 
PM<INF>2.5</INF>. The Plan provides several forms of evidence to 
indicate that reductions in NO<INF>X</INF> emissions are effective in 
reducing PM<INF>2.5</INF> concentrations exceeding the standard, and 
also that they are more effective than reductions in ammonia emissions. 
The evidence includes speciated data from ambient PM<INF>2.5</INF> 
monitors, model simulations of NO<INF>X</INF> emission reductions, 
historical trends, and the relative amounts of NO<INF>X</INF> and 
ammonia.
---------------------------------------------------------------------------

    \85\ 2015 PM<INF>2.5</INF> Plan, WOEA, Figures 6 and 7, p. A-16.
---------------------------------------------------------------------------

    The 2015 PM<INF>2.5</INF> Plan indicates that the ambient 
contribution of NO<INF>X</INF> to PM<INF>2.5</INF> levels in the SJV is 
substantial. According to available speciation data, ammonium nitrate 
is the largest chemical component of ambient PM<INF>2.5</INF> in the 
SJV, as measured in the southern (Bakersfield), central (Fresno), and 
northern (Modesto) portions of San Joaquin Valley. It comprises 38-41% 
of the 2010-2012 average annual PM<INF>2.5</INF> concentrations and 53-
64% of the 2011-2013 average peak 24-hour PM<INF>2.5</INF> 
concentrations, the highest percentages being observed in 
Bakersfield.\86\ Using the 2011-2013 annual average PM<INF>2.5</INF> 
design value of 17.3 [mu]g/m\3\ at the Bakersfield-Planz site,\87\ the 
ammonium nitrate concentration is approximately 7.1 [mu]g/m\3\. If only 
nitrate itself is considered (i.e., the nitrate part of the ammonium 
nitrate molecules), the contribution of NO<INF>X</INF> represents 5.5 
[mu]g/m\3\, which is approximately 31.8% of the annual average 
PM<INF>2.5</INF> concentration.\88\
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    \86\ Id.
    \87\ 2015 PM<INF>2.5</INF> Plan, Appendix A, p. A-9. The design 
value for the Bakersfield-Planz site for 2011-2013 is given as a 
rounded value of 17.0 [mu]g/m\3\ in Table A-6 in Appendix A of the 
Plan. For greater precision in estimating species contributions, we 
have used the unrounded value of 17.3 [mu]g/m\3\, which we 
calculated as the average of the 98th percentiles values for each 
year (14.5, 14.7, and 22.8) as listed in Appendix A, Table A-5. We 
used the Bakersfield-Planz site (the second highest 2011-2013 annual 
average) in lieu of the Madera-City site (highest average), 
consistent with the Plan's weight of evidence for the attainment 
demonstration. Similarly consistent with the attainment 
demonstration, this 17.3 [mu]g/m3 value excludes the data from May 
5, 2013 for Bakersfield-Planz. Section V.E.5 of this proposed rule 
has further discussion of these matters. For calculating the 
ammonium nitrate concentration, we used the 41% value from the 
Bakersfield pie chart in the 2015 PM<INF>2.5</INF> Plan, WOEA, 
Figure 6, p. A-16.
    \88\ The nitrate fraction of ammonia nitrate (5.5 [mu]g/m\3\) is 
calculated as molecular weight of nitrate (62) divided by the 
molecular weight of ammonium nitrate (80) and equals 77.5 percent.
---------------------------------------------------------------------------

    Similarly, using the 2011-2013 24-hour PM<INF>2.5</INF> design 
value of 64.6 [mu]g/m\3\ at the Bakersfield-California site,\89\ the 
24-hour average ammonium nitrate

[[Page 6946]]

concentration on peak PM<INF>2.5</INF> days is approximately 41.3 
[mu]g/m\3\. If only nitrate itself is considered (i.e., the nitrate 
part of the ammonium nitrate molecules), the contribution of 
NO<INF>X</INF> represents 32.0 [mu]g/m\3\, which is approximately 49.6% 
of the average peak 24-hour PM<INF>2.5</INF> concentration. Whether 
considered as ammonium nitrate or simply as nitrate, NO<INF>X</INF> is 
clearly a significant contributor to ambient PM<INF>2.5</INF> levels 
above the standard in the SJV.
---------------------------------------------------------------------------

    \89\ 2015 PM<INF>2.5</INF> Plan, Appendix A, p. A-8. The design 
value for Bakersfield-California (the high site for monitors with 
complete data for the three years) for 2011-2013 is given as a 
rounded value of 65 [mu]g/m\3\ in Table A-4 in Appendix A of the 
Plan. For greater precision in estimating species contributions, we 
have used the unrounded value of 64.6 [mu]g/m\3\, which we 
calculated as the average of the 98th percentiles values for each 
year (65.5, 56.4, and 71.8) as listed in Table A-3. For calculating 
the ammonium nitrate concentration, we used the 64% value from the 
Bakersfield pie chart in the 2015 PM<INF>2.5</INF> Plan, WOEA, 
Figure 7, p. A-16.
---------------------------------------------------------------------------

    In addition to this evidence concerning the contribution of 
NO<INF>X</INF> to PM<INF>2.5</INF> concentrations, the 2015 
PM<INF>2.5</INF> Plan provides evidence that ambient PM<INF>2.5</INF> 
concentrations are sensitive to NO<INF>X</INF> reductions (i.e., 
nitrate PM<INF>2.5</INF> concentrations decrease when NO<INF>X</INF> 
emissions are reduced). The evidence is from modeling, historical 
trends, and relative proportions of NO<INF>X</INF> and ammonia. The 
2015 PM<INF>2.5</INF> Plan provides evidence from past and current 
photochemical modeling simulations that ambient ammonium nitrate is 
sensitive to NO<INF>X</INF> reductions. The Plan describes past 
modeling studies that were documented in academic journals.\90\ In the 
various studies, when NO<INF>X</INF> emissions were reduced by 50%, 
ambient ammonium nitrate decreased by 25-50%, depending on the episode 
modeled and the geographic location.\91\ In addition, modeling for the 
2012 PM<INF>2.5</INF> Plan for the 2006 24-hour PM<INF>2.5</INF> NAAQS, 
whose results were relied on for the 2015 PM<INF>2.5</INF> Plan, also 
shows substantial sensitivity of ambient PM<INF>2.5</INF> 
concentrations to reductions in NO<INF>X</INF> emissions. The State 
modeled the effect of a 25% reduction in NO<INF>X</INF> emissions on 
ambient 24-hour PM<INF>2.5</INF> concentrations in 2019 and combined 
this with the emission mass (tons per day) to determine that the 
PM<INF>2.5</INF> concentrations would be reduced by 0.08 [mu]g/m3 at 
the Bakersfield-California site (the design value site for 2019) and 
decreases of a similar order of magnitude (i.e., 0.03 to 0.09 [mu]g/m3) 
at other monitors in the SJV.\92\
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    \90\ The academic journal papers are described in 2015 
PM<INF>2.5</INF> Plan, WOEA, Section 5 (``Secondary Ammonium Nitrate 
Formation''), pp. A-23-A-29.
    \91\ Chen, J., Lu, J., Avise, J.C., DaMassa, J.A., Kleeman, 
M.J., Kaduwela, A.P., 2014, Seasonal Modeling of PM<INF>2.5</INF> in 
California's San Joaquin Valley, Atmospheric Environment, 92, 182-
190, doi:10.1016/j.atmosenv.2014.04.030. Kleeman, M.J., Ying, Q., 
and Kaduwela, A., Control strategies for the reduction of airborne 
particulate nitrate in California's San Joaquin Valley, Atmospheric 
Environment, 2005, 39, 5325-5341. Liang, J., G[uuml]rer, 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. Livingstone, P.L. et. al., 2009, 
``Simulating PM Concentrations During a Winter Episode in a 
Subtropical Valley and Sensitivity Simulations and Evaluation 
methods'', Atmospheric Environment, 43: 5971-5977. doi:10.1016/
j.atmosenv.2009.07.033. Pun, B.K., Balmori R.T.F, and Seigneur, C., 
2009, Modeling wintertime particulate matter formation in Central 
California, Atmospheric Environment, 43, 402-409. Different models 
and emission inventories in these studies conducted over the years 
also contribute to the variation in results.
    \92\ 2015 PM<INF>2.5</INF> Plan, WOEA, Table B-2 (``Modeled 
PM<INF>2.5</INF> air quality benefit per ton of valley-wide 
precursor emission reductions''), p. A-27.
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    The 2015 PM<INF>2.5</INF> Plan provides additional (non-modeling) 
evidence on the effectiveness of NO<INF>X</INF> reductions. The 
historical downward trends of NO<INF>X</INF> emissions and of ambient 
nitrate concentrations are discussed in Chapter 2 and the weight of 
evidence analysis (WOEA) of the Plan.\93\ Annual average NO<INF>X</INF> 
emissions levels are plotted against ammonium nitrate concentrations at 
Bakersfield and Fresno, and in each case have decreased by about 35-40% 
from 2004 to 2012.\94\ This shows that NO<INF>X</INF> emissions and 
ammonium nitrate concentrations are correlated with one another. The 
conclusion that PM<INF>2.5</INF> nitrate concentrations are more 
limited by NO<INF>X</INF> emissions than by ammonia emissions is 
strengthened by the fact that this reduction in ambient ammonium 
nitrate occurred despite an increase in emissions of ammonia, the other 
precursor to ammonium nitrate, during the same period.\95\
---------------------------------------------------------------------------

    \93\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, pp. 2-8 and 2-9; and 
CARB's Staff Report, Appendix A (i.e., WOEA), pp. A-60 to A-61.
    \94\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, Figure 2-19, p. 2-
26; 2015 PM<INF>2.5</INF> Plan, CARB Staff Report, pp. 5-6; and 
WOEA, Figure 44, p. A-60.
    \95\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, p. 2-24.
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    The 2015 PM<INF>2.5</INF> Plan further describes the effectiveness 
of NO<INF>X</INF> controls by characterizing it as the ``limiting 
precursor'' in ammonium nitrate formation, based on the relative 
amounts of NO<INF>X</INF> and ammonia. Based on monitored 
concentrations and the emissions inventory, CARB and the SJVUAPCD 
conclude that NO<INF>X</INF> is the limiting precursor and briefly 
illustrates this concept in its WOEA.\96\ One molecule each of 
NO<INF>X</INF> and ammonia is required to form each molecule of 
ammonium nitrate. If NO<INF>X</INF> is in short supply relative to 
ammonia, then NO<INF>X</INF> is the limiting factor in ammonium nitrate 
formation.\97\
---------------------------------------------------------------------------

    \96\ 2015 PM<INF>2.5</INF> Plan, WOEA, section 5.b, pp. A-18 to 
A-19. See also 2015 p.m.2.5 Plan, Chapter 2, section 2.6, pp. 2-18 
to 2-27.
    \97\ As noted below in the ammonia subsection, the ``limiting 
precursor'' concept is not absolute, and must be used with caution. 
However, for NO<INF>X</INF> it does support evidence from the 
modeling results that NO<INF>X</INF> significantly contributes to 
exceedances of the 1997 PM<INF>2.5</INF> NAAQS.
---------------------------------------------------------------------------

    The WOEA analysis includes plots \98\ of ammonia and nitric acid 
(which contains nitrate) concentrations at two monitoring sites in the 
SJV (Angiola, a rural site, and Fresno, an urban site) that were 
measured during the winter 2000-2001 CRPAQS \99\ study and reported in 
Lurmann et al. (2006).\100\ CARB notes that in this study, ammonia 
concentrations are at least an order of magnitude larger than those of 
nitrate and notes Lurmann et al.'s conclusion that NO<INF>X</INF> is 
the limiting precursor. CARB and the SJVUAPCD did not, however, present 
more current information about ammonia concentrations.
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    \98\ 2015 PM<INF>2.5</INF> Plan, WOEA, Figures 11 and 12, pp. A-
21 to A-22.
    \99\ CRPAQS is the California Regional Particulate Air Quality 
Study. More information is available about CRPAQS at http://www.arb.ca.gov/airways/ccaqs.htm.
    \100\ Lurmann, F.W., Brown, S.G., McCarthy, M.C., and Roberts, 
P.T., December 2006, Processes Influencing Secondary Aerosol 
Formation in the San Joaquin Valley during Winter, Journal of Air 
and Waste Management Association, 56, 1679-1693.
---------------------------------------------------------------------------

    The WOEA also considers emissions inventories to support the 
argument that NO<INF>X</INF> is the limiting precursor. The WOEA 
normalized NO<INF>X</INF> emissions using the relative molecular 
weights of NO<INF>X</INF> and ammonia, in order to reflect the number 
of molecules of each available to react with each other.\101\ In 2012, 
the normalized amount of NO<INF>X</INF> available was 37-38% of the 
amount of ammonia for both annual and winter averages, while it is 
projected to be 21% of the amount of ammonia in 2020. This shows the 
scarcity of NO<INF>X</INF> relative to ammonia and implies that 
NO<INF>X</INF> is the limiting precursor in the formation of ammonium 
nitrate.
---------------------------------------------------------------------------

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

    Based on the range of technical analyses provided in the Plan and 
other information available to the EPA, we agree with the State's and 
District's conclusion that NO<INF>X</INF> controls must be included in 
the evaluation of potential control measures for the 1997 
PM<INF>2.5</INF> standards in the SJV, consistent with the requirements 
of subpart 4.
c. Ammonia
    The 2015 PM<INF>2.5</INF> Plan states that, based on modeling, 
emissions inventory, and monitoring studies, ``[b]ecause of [the] 
regional surplus in ammonia, even substantial ammonia emissions 
reductions yield a relatively small reduction in nitrate'' \102\ and 
``[a]mmonia emission reductions are approximately an order of magnitude 
less effective'' than NO<INF>X</INF> emission reductions in reducing 
ambient PM<INF>2.5</INF>

[[Page 6947]]

concentrations.\103\ To support this finding, CARB and the SJVUAPCD 
discuss the ambient contribution of ammonia to measured 
PM<INF>2.5</INF> levels in the SJV and the sensitivity of ambient 
PM<INF>2.5</INF> to ammonia reductions. The latter includes discussion 
of the relative abundance of NO<INF>X</INF> and ammonia, and of modeled 
simulations of further reductions in ammonia emissions.
---------------------------------------------------------------------------

    \102\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, p. 2-19.
    \103\ WOEA, p. A-29.
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    The Plan indicates that ammonia contributes to ambient 
concentrations of PM<INF>2.5</INF>, in the form of ammonium nitrate and 
ammonium sulfate. As noted above in our discussion of NO<INF>X</INF>, 
ammonium nitrate comprises 38-41% of the 2010-2012 average annual 
PM<INF>2.5</INF> concentrations and 53-64% of the 2011-2013 average 
peak 24-hour PM<INF>2.5</INF> concentrations, the highest percentages 
being observed in Bakersfield.\104\ Ammonium sulfate contributes an 
additional 11-14% of the 2010-2012 average annual PM<INF>2.5</INF> 
concentrations and 4-6% of the 2011-2013 average peak 24-hour 
PM<INF>2.5</INF> concentrations, with the highest percentages similarly 
being observed in Bakersfield.\105\
---------------------------------------------------------------------------

    \104\ 2015 PM<INF>2.5</INF> Plan, WOEA, Figures 6 and 7, p. A-
16.
    \105\ Id.
---------------------------------------------------------------------------

    Using the highest 2011-2013 annual average PM<INF>2.5</INF> design 
value of 17.3 [micro]g/m\3\ at the Bakersfield-Planz site, the ammonium 
nitrate concentration is approximately 7.1 [micro]g/m\3\ and the 
ammonium sulfate concentration is approximately 2.4 [micro]g/m\3\.\106\ 
If only ammonium is considered (i.e., the ammonium part of the ammonium 
nitrate and ammonium sulfate molecules), the contribution of ammonium 
represents 2.3 [micro]g/m\3\, or 13.0% of the annual average 
PM<INF>2.5</INF> concentration.\107\
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    \106\ See n. 87 supra. In addition, for calculating the ammonium 
sulfate concentration, we used the 14% ammonium sulfate values from 
the Bakersfield pie chart in the 2015 PM<INF>2.5</INF> Plan, WOEA, 
Figure 6, p. A-16.
    \107\ The ammonium fraction of ammonium nitrate (1.6 [micro]g/
m\3\) is calculated as the molecular weight of ammonium (18) divided 
by the molecular weight of ammonium nitrate (80), which is 22.5 
percent of the mass. The ammonium fraction of ammonium sulfate (0.7 
[micro]g/m\3\) is calculated as the molecular weight of the two 
ammonium molecules (36) divided by the molecular weight of ammonium 
sulfate (132), which is 27.3 percent of the mass.
---------------------------------------------------------------------------

    Similarly, using the 2011-2013 24-hour PM<INF>2.5</INF> design 
value of 64.6 [micro]g/m\3\ at the Bakersfield-California site, the 24-
hour average ammonium nitrate concentration on peak PM<INF>2.5</INF> 
days is approximately 41.3 [micro]g/m\3\ and the ammonium sulfate 
concentration is approximately 3.9 [micro]g/m\3\.\108\ If only ammonium 
itself is considered (i.e., the ammonium part of the ammonium nitrate 
and ammonium sulfate molecules), the contribution of ammonium 
represents 10.4 [micro]g/m\3\, which is approximately 16.0% of the 
average peak 24-hour PM<INF>2.5</INF> concentration.\109\
---------------------------------------------------------------------------

    \108\ See n. 89 supra. In addition, for calculating the ammonium 
sulfate concentration, we used the 6% ammonium sulfate values from 
the Bakersfield pie chart in the 2015 PM<INF>2.5</INF> Plan, WOEA, 
Figure 6, p. A-16.
    \109\ The ammonium fraction of ammonium nitrate (9.3 [micro]g/
m\3\) is calculated as the molecular weight of ammonium (18) divided 
by the molecular weight of ammonium nitrate (80), which is 22.5 
percent of the mass. The ammonium fraction of ammonium sulfate (1.1 
[micro]g/m\3\) is calculated as the molecular weight of the two 
ammonium molecules (36) divided by the molecular weight of ammonium 
sulfate (132), which is 27.3 percent of the mass.
---------------------------------------------------------------------------

    Ammonia emissions are essential to the formation of both of these 
components of the ambient particulate matter, and the EPA finds that 
these levels of contribution are a substantial fraction of the SJV's 
2011-2013 annual average design value of 17.3 [micro]g/m\3\, as 
measured at the Bakersfield-Planz site, and the 24-hour design value of 
64.6 [micro]g/m\3\, as measured at the Bakersfield-California site. 
This is evidence that emissions of ammonia contribute significantly to 
ambient PM<INF>2.5</INF> concentrations that exceed the 1997 
PM<INF>2.5</INF> NAAQS in the SJV.
    Next we examined information in the 2015 PM<INF>2.5</INF> Plan 
regarding the sensitivity of ambient PM<INF>2.5</INF> levels in the SJV 
to potential ammonia emission control. On this issue there is 
conflicting evidence. Based on evidence that ammonia appears not to be 
the limiting precursor for ammonium nitrate formation and that modeled 
ammonia reductions are ineffective relative to NO<INF>X</INF> 
reductions,\110\ CARB and the SJVUAPCD conclude that controls for 
ammonia are not warranted. However, the EPA's own evaluation of the 
modeling indicates that ammonia controls can be effective at reducing 
ambient PM<INF>2.5</INF> in some locations and can be more effective at 
certain times of year.
---------------------------------------------------------------------------

    \110\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, Section 2.6.2, pp. 
2-21 to 2-27 and WOEA, pp. A-23 to A-29.
---------------------------------------------------------------------------

    CARB and the SJVUAPCD 's evidence discussed above to support the 
argument that NO<INF>X</INF> is the limiting precursor for ammonia 
nitrate formation is also presented as evidence that ammonia is not the 
limiting precursor, and thus to argue that ambient PM<INF>2.5</INF> 
levels would not be sensitive to ammonia reductions.\111\ In the Plan, 
CARB and the SJVUAPCD state that there is both an abundance of ambient 
ammonia relative to ambient nitrate, and an abundance of ammonia 
emissions relative to NO<INF>X</INF> emissions. CARB and the SJVUAPCD 
also indicate that there is an abundance of gaseous ammonia relative to 
particulate ammonium at multiple locations during the 2000-2001 winter 
episode in the CRPAQS study,\112\ so that even under conditions 
favorable to ammonium nitrate formation, a substantial amount of 
unreacted ammonia remains.\113\ Based on these multiple pieces of 
evidence on the abundance of ammonia, CARB and the SJVUAPCD conclude 
that ammonia is not the limiting factor for ammonium nitrate formation 
and, thus, that reducing ammonia emissions would not reduce ambient 
PM<INF>2.5</INF> in the SJV.
---------------------------------------------------------------------------

    \111\ WOEA, pp. A-18 to A-22.
    \112\ WOEA, pp. A-22 and Figure 13, p. A-23.
    \113\ As noted above, NO<INF>X</INF> emissions have been 
decreasing and ammonia emissions increasing, so under the State's 
reasoning, this relationship would be expected to continue.
---------------------------------------------------------------------------

    CARB and the SJVUAPCD also considered air quality modeling analyses 
to evaluate the effectiveness of reducing ammonia as compared to other 
precursors, and to PM<INF>2.5</INF> decreases needed for attainment. 
Based on modeling a 25% reduction in ammonia emissions, holding direct 
PM<INF>2.5</INF> and other precursor emissions constant, the Plan 
states that per ton per day of ammonia emissions reduction, there would 
be a 0.005 to 0.010 [micro]g/m\3\ decrease in ambient PM<INF>2.5</INF> 
concentrations across the Valley, including a 0.008 [micro]g/m\3\ 
effect at the Bakersfield-California site.\114\ By comparing these 
sensitivities to the effect of a 25% reduction of NO<INF>X</INF> 
emissions, the Plan states that, on a per ton basis, reducing ammonia 
is only about 10% as effective as reducing NO<INF>X</INF>.\115\ Thus, 
based on this air quality modeling, CARB and the SJVUAPCD conclude that 
additional ammonia control is considerably less effective than 
NO<INF>X</INF> control.
---------------------------------------------------------------------------

    \114\ WOEA, Table 2, p. A-27.
    \115\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, p. 27.
---------------------------------------------------------------------------

    The State and District assume in the 2015 PM<INF>2.5</INF> Plan 
that additional ammonia control, as modeled, would provide limited 
benefit for attainment planning purposes. They also conclude, based 
upon the various forms of information and analyses described above, 
that ammonia emission reductions are much less effective than direct 
PM<INF>2.5</INF> or NO<INF>X</INF> emission reductions, and thus argue 
that ``[a]mmonia is not a significant precursor to PM<INF>2.5</INF> 
values in the Valley.'' \116\
---------------------------------------------------------------------------

    \116\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, p. 2-27.
---------------------------------------------------------------------------

    The EPA finds the modeling and other analyses presented and 
referred to in the 2015 PM<INF>2.5</INF> Plan to be credible, but the 
modeling analyses nonetheless show

[[Page 6948]]

that additional reductions in ammonia may reduce ambient 
PM<INF>2.5</INF> levels to varying degrees. In the various studies, 
when ammonia emissions were reduced by up to 50%, ambient ammonium 
nitrate decreased by a range of approximately 5-25%, depending on the 
episode modeled and the geographic location evaluated.\117\ Modeling 
conducted by ARB staff for the 2012 PM<INF>2.5</INF> Plan for attaining 
the 2006 24-hour PM<INF>2.5</INF> NAAQS indicated that for emissions 
reduction within Kern County, a one ton per day decrease in ammonia 
would lead to a 0.02 [micro]g/m\3\ improvement in the PM<INF>2.5</INF> 
24-hour design value.\118\ If this rate were to remain constant as 
ammonia emissions decrease, and if this same sensitivity applied to 
valley-wide reductions, it would mean that a 50% reduction in the 
ammonia emissions inventory (estimated in the 2015 PM<INF>2.5</INF> 
Plan at 329.5 tpd annual average in 2012) would be expected to reduce 
24-hour PM<INF>2.5</INF> concentrations by more than 3 [micro]g/m\3\, 
an amount that the EPA would not consider insignificant.
---------------------------------------------------------------------------

    \117\ WOEA, pp. A-24 to A-25.
    \118\ WOEA, p. A-29.
---------------------------------------------------------------------------

    The percentages for ammonia benefits are generally smaller than 
those for NO<INF>X</INF> reductions, but a range of modeling results 
show that reductions in ammonia emissions under certain circumstances 
can effectively help to reduce ambient PM<INF>2.5</INF>. The fact that 
all the modeling studies find at least some benefit from ammonia 
control shows that the concept of NO<INF>X</INF> as a ``limiting 
precursor'' in the formation of ammonium nitrate particles discussed 
above is not absolute. In addition, the test for determining whether 
emission reduction measures for a particular precursor must be 
evaluated for purposes of timely attainment should not be based 
exclusively on the control effectiveness of the precursor relative to 
other precursors, but must also consider whether emissions of the 
precursor ``contribute significantly'' to ambient PM<INF>2.5</INF> 
levels which exceed the PM<INF>2.5</INF> standards in the nonattainment 
area. In other words, the fact that control of NO<INF>X</INF> may be 
more important than the control of ammonia in relative terms does not 
mean that a state should not evaluate regulations for both as part of a 
comprehensive plan to attain the PM<INF>2.5</INF> NAAQS, and to do so 
expeditiously as required by the CAA.
    Taking into consideration a number of factors, the EPA does not 
agree with the conclusion in the Plan that the more than 100,000 annual 
tons of ammonia emissions from sources in the SJV area do not 
contribute significantly to PM<INF>2.5</INF> levels exceeding the 1997 
PM<INF>2.5</INF> NAAQS. First, the information provided by the State 
and District in the Plan shows that ammonia contributes to a large 
fraction of measured PM<INF>2.5</INF> concentrations in the SJV area, 
in the form of ammonium nitrate and, to a lesser extent, ammonium 
sulfate. Based on data presented in the 2015 PM<INF>2.5</INF> Plan, 
ammonia emissions, in the form of ammonium, are responsible for 
approximately 13% of the annual average concentration and 16% of the 
24-hour average at the design value site for the San Joaquin Valley.
    Second, modeled evidence submitted by the State and studies 
available to the EPA indicate that although ammonia control is less 
effective at reducing PM<INF>2.5</INF> concentrations compared to 
NO<INF>X</INF> control, reducing ammonia emissions in the SJV would 
reduce PM<INF>2.5</INF> by varying amounts throughout the nonattainment 
area. Studies indicate that reducing ammonia does not have a uniform 
effect across a large nonattainment area during all times of the year; 
ammonia reductions can be more effective at reducing PM<INF>2.5</INF> 
concentrations in specific locations during certain times of the year. 
Reductions in ammonia in conjunction with reductions of direct 
PM<INF>2.5,</INF> SO<INF>2</INF>, and NO<INF>X</INF> would help to 
provide for attainment of the PM<INF>2.5</INF> NAAQS in the SJV area.
    Finally, despite the fact that a broad range of emission reduction 
measures have been implemented to reduce emissions of direct 
PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors, the Plan also 
indicates that attainment by the statutory attainment date is 
impracticable. This underscores the continuing severity of the 
PM<INF>2.5</INF> nonattainment problem in the SJV and the need for a 
robust assessment of potential control measures (e.g., BACM and MSM) 
for direct PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors, including 
potential ammonia control measures which may be effective in reducing 
ambient PM<INF>2.5</INF> concentrations.
    Given the severity of the PM<INF>2.5</INF> nonattainment problem in 
the SJV, the high degree to which controls have already been applied to 
the emission of PM<INF>2.5</INF> and its precursor pollutants, the 
demonstration that attainment in the SJV by 2015 is impracticable, and 
the documentation in the 2015 PM<INF>2.5</INF> Plan showing that 
ammonia emissions are responsible for more than 2 [micro]g/m\3\ of the 
annual average PM<INF>2.5</INF> concentration at the Bakersfield-Planz 
site, and for more than 10 [micro]g/m\3\ of the peak day 24-hour 
average PM<INF>2.5</INF> concentration at the Bakersfield-California 
site, the EPA does not agree at this time with the conclusion in the 
Plan that ammonia emissions do not contribute significantly to 
PM<INF>2.5</INF> levels exceeding the PM<INF>2.5</INF> standards in the 
SJV.
    Although the Plan states that ammonia is not a significant 
precursor to ambient PM<INF>2.5</INF> levels, and that additional 
controls for ammonia are not necessary to attain the PM<INF>2.5</INF> 
standards in the SJV, the Plan nonetheless provides an evaluation of 
control measures currently implemented in the SJV that reduce ammonia 
emissions and other potential ammonia control measures. We discuss the 
State's ammonia control evaluation in section V.D. of this proposed 
rule.
d. VOC
    The 2015 PM<INF>2.5</INF> Plan states that VOCs are not a 
significant precursor to ambient PM<INF>2.5</INF> levels in the San 
Joaquin Valley and that further reductions in VOC emissions would not 
contribute to PM<INF>2.5</INF> attainment. To support this finding, 
CARB and the SJVUAPCD discuss the ambient contribution of VOC to 
measured PM<INF>2.5</INF> levels in the SJV, the indirect role of VOC 
in ammonium nitrate formation, and modeled simulations of further 
reductions in VOC emissions.
    There are two routes by which VOC can contribute to ambient 
PM<INF>2.5</INF>. 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 
NO<INF>X</INF> emissions to nitrate or SO<INF>X</INF> emissions to 
sulfate, leading to the formation of particulate ammonium nitrate or 
particulate ammonium sulfate. Chapter 2 of the 2015 PM<INF>2.5</INF> 
Plan discusses both roles of VOC in PM<INF>2.5</INF> formation,\119\ as 
does the Plan's weight of evidence analysis.\120\
---------------------------------------------------------------------------

    \119\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, pp. 2-20 to 2-21.
    \120\ WOEA, section 5.d (``Role of VOC in ammonium nitrate 
formation''), pp. A-30 to A-39, and section 6 (``Secondary Organic 
Aerosol Formation''), pp. A-39 to A-40.
---------------------------------------------------------------------------

    For the direct contribution of VOC to PM<INF>2.5</INF>, the 2015 
PM<INF>2.5</INF> Plan states that modeling for annual average 
PM<INF>2.5</INF> for the 2008 PM<INF>2.5</INF> Plan found that 
anthropogenic SOA were about 3-5% of total organic aerosol, and that 
SOA were mainly formed during the summer from non-anthropogenic 
sources.\121\ The SJVUAPCD states that the winter anthropogenic 
contribution that is of interest for the 1997 24-hour PM<INF>2.5</INF> 
NAAQS would necessarily be lower because less SOA forms at winter 
temperatures, which are lower than temperatures for the annual average. 
CARB and the SJVUAPCD also cite a

[[Page 6949]]

study by Chen et al.\122\ for the winter 2000-2001 CRPAQS episode. This 
study found that the SOA portion of total organic aerosol had a maximum 
value of 4.26 [micro]g/m\3\ with concentrations at Bakersfield of 2.28 
[micro]g/m\3\ and at Fresno of 2.46 [micro]g/m\3\, which represent 4% 
and 6% of the total organic aerosol at those locations. These locations 
typically represent the highest PM<INF>2.5</INF> concentrations for the 
southern and central portions of the San Joaquin Valley.
---------------------------------------------------------------------------

    \121\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, p. 2-20.
    \122\ Chen, J., Ying, Q., and Kleeman, M.J., 2010, Source 
apportionment of wintertime secondary organic aerosol during the 
California regional PM<INF>10</INF>/PM<INF>2.5</INF> air quality 
study, Atmospheric Environment, 44(10), 1331-1340.
---------------------------------------------------------------------------

    Applying this roughly 5% SOA proportion to the organic carbon 
portion of the measured 2011-2013 peak day 24-hour average 
PM<INF>2.5</INF> composition shows that, by mass, SOA is about 0.9% of 
total ambient PM<INF>2.5</INF> at Bakersfield-California and 1.5% of 
ambient PM<INF>2.5</INF> at Fresno.\123\ The EPA notes that because 
anthropogenic SOA is only a portion of the total SOA, the portion due 
to controllable anthropogenic sources would be even less. CARB and the 
SJVUAPCD conclude that these modeling studies show that SOA is not a 
substantial component of peak day (i.e., winter) 24-hour ambient 
PM<INF>2.5</INF> concentrations in the SJV and that the potential for 
reducing ambient PM<INF>2.5</INF> through VOC emission reductions is 
very limited. We do not have comparable information at this time to 
evaluate whether or not SOA is a substantial component of annual 
average PM<INF>2.5</INF> concentrations.
---------------------------------------------------------------------------

    \123\ The contribution of Organic Matter to 2011-2013 peak day 
24-hour PM<INF>2.5</INF> levels was 18 percent at Bakersfield and 30 
percent at Fresno (see WOEA, Figure 7, p. A-16). Five percent of 
these proportions gives 0.90 percent SOA at Bakersfield and 1.5 
percent SOA at Fresno. As a fraction of the 2013 design values of 
64.6 [micro]g/m\3\ at Bakersfield-California and 63.5 [micro]g/m\3\ 
at Fresno-Winery, these percentages give SOA contributions of 0.58 
[micro]g/m\3\ at Bakersfield-California and 0.95 [micro]g/m\3\ at 
Fresno-Winery.
---------------------------------------------------------------------------

    For the indirect contribution of VOC to PM<INF>2.5</INF>, nitrate 
formation via daytime photochemistry, CARB and the SJVUAPCD assert that 
this route is also not a substantial contributor, based on modeled 
sensitivity to VOC reductions. For one such study there were relatively 
low modeled concentrations of ozone, which did not appear consistent 
with nitrate formation via daytime oxidant (ozone) photochemistry, 
which would be expected to have elevated ozone levels.\124\ The Plan 
reviews essentially the same studies that the State relied on in the 
2008 PM<INF>2.5</INF> Plan for attainment of the 1997 PM<INF>2.5</INF> 
standards,\125\ except for one additional 2014 study by Chen et. 
al.\126\ The EPA's review of these studies and of the 2008 
PM<INF>2.5</INF> Plan's examination of the studies is covered in the 
technical support document (TSD) for the EPA's final action on the 2008 
PM<INF>2.5</INF> Plan (``2008 PM<INF>2.5</INF> Plan TSD'').\127\ The 
2014 Chen et. al. paper presented results of modeling the 1st and 4th 
quarters of 2007 using the CMAQ model (the same period and model that 
was used for the 2008 PM<INF>2.5</INF> Plan), and also of modeling the 
winter 2000 CRPAQS episode using the UCD/CIT (University of California, 
Davis/California Institute of Technology) model. The paper explored the 
sensitivity of PM<INF>2.5</INF> to reductions of the various 
precursors. The CMAQ modeling showed that reducing anthropogenic VOC 
actually increases PM<INF>2.5</INF> design values, while the UCD/CIT 
modeling showed that it has a negligible effect. NO<INF>X</INF> vs. VOC 
isopleth diagrams from the paper are reproduced in the 2015 
PM<INF>2.5</INF> Plan, and illustrate these effects.\128\
---------------------------------------------------------------------------

    \124\ 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.
    \125\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, pp. 2-20 to 2-21; 
WOEA, p. A-3, and section 5.d, pp. A-30 to A-39.
    \126\ Chen, J., Lu, J., Avise, J.C., DaMassa, J.A., Kleeman, 
M.J., Kaduwela, A.P., 2014, Seasonal Modeling of PM<INF>2.5</INF> in 
California's San Joaquin Valley, Atmospheric Environment, 92, 182-
190, doi: 10.1016/j.atmosenv.2014.04.030.
    \127\ EPA Region 9, ``Technical Support Document and Responses 
to Comments Final Rule on the San Joaquin Valley 2008 
PM<INF>2.5</INF> State Implementation Plan,'' September 30, 2011, 
section II.C.
    \128\ WOEA, p. A-37 to A-38, Figs. 23 and 24. PM<INF>2.5</INF> 
increases when VOC decreases, for any given level of NO<INF>X</INF>.
---------------------------------------------------------------------------

    The findings from those reviews remain the same for the current 
Plan: Past modeling studies vary on whether controlling VOC reduces 
PM<INF>2.5</INF>, but the most reliable ones show VOC control has 
little benefit, or even a disbenefit. As detailed in the EPA's 2008 
PM<INF>2.5</INF> Plan TSD and in the Plan's WOEA,\129\ the studies for 
which VOC control showed a benefit at some times and places are less 
reliable because they used unrealistic emissions levels, unrealistic 
control scenarios, or the effect occurred at PM<INF>2.5</INF> 
concentrations no longer reached in the SJV. The WOEA also suggests 
that, in this context of indirect PM<INF>2.5</INF> formation from VOC, 
the model boundary conditions have sufficient ozone flowing in from 
outside the SJV area,\130\ implying that VOC reductions would have 
little effect on ambient PM<INF>2.5</INF> levels exceeding the standard 
in the SJV.
---------------------------------------------------------------------------

    \129\ WOEA, p. A-3, and section 5.d, pp. A-30 to A-39.
    \130\ WOEA, p. A-38. See also, Kleeman, M.K., Ying, Q., and 
Kaduwela, A., 2005, Control strategies for the reduction of airborne 
particulate nitrate in California's San Joaquin Valley, Atmospheric 
Environment, 39: 5325-5341 September 2005. doi: 10.1016/
j.atmosenv.2005.05.044; cited in Plan Modeling Protocol.p.F-36). A 
similar statement is made in the 2014 Chen et al. paper, citing Qi 
Ying, Jin Lu, Michael Kleeman, Modeling air quality during the 
California Regional PM<INF>10</INF>/PM<INF>2.5</INF> Air Quality 
Study (CPRAQS) using the UCD/CIT source-oriented air quality model--
Part III. Regional source apportionment of secondary and total 
airborne particulate matter, Atmospheric Environment, Volume 43, 
Issue 2, January 2009, Pages 419-430, ISSN 1352-2310, DOI: 10.1016/
j.atmosenv.2008.08.033. The Chen paper actually cites ``Part I'' of 
the Ying paper, not this Part III. However, none of these papers 
gives the basis for the statement that background ozone is the 
dominant nitrate oxidant.
---------------------------------------------------------------------------

    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 PM<INF>2.5</INF> concentrations.
    The modeling for the prior 2012 PM<INF>2.5</INF> Plan, which 
indicates a disbenefit from controlling VOC at important geographic 
locations, adds to the evidence from past studies, and is incorporated 
into the 2015 PM<INF>2.5</INF> Plan. This is shown by negative 
PM<INF>2.5</INF> sensitivities (that is, decreased VOC emissions result 
in increased PM<INF>2.5</INF> levels) for multiple locations.\131\ In 
addition, a diagram of model PM<INF>2.5</INF> response at the 
Bakersfield-California site to various combinations of NO<INF>X</INF> 
and VOC reductions show graphically that VOC reductions increase 
PM<INF>2.5</INF>, for any given level of NO<INF>X</INF>.\132\ For other 
monitoring sites, such as Fresno and Angiola, these NO<INF>X</INF> vs. 
VOC diagrams show mixed effects on PM<INF>2.5</INF>, albeit generally 
of small magnitude, depending on the level of ambient PM<INF>2.5</INF> 
as VOC emissions are reduced.
---------------------------------------------------------------------------

    \131\ WOEA, Table 2, p. A-27 (see VOC columns for Bakersfield, 
Visalia, and Corcoran).
    \132\ WOEA, Figure 18, p. A-28. This diagram shows the model 
PM<INF>2.5</INF> response at the Bakersfield-California site to 
reductions in various combinations of precursors. Subfigure ``b)'' 
shows NO<INF>X</INF> reductions plotted against VOC reductions. For 
a given level of NO<INF>X</INF>, in decreasing VOC by moving 
leftward along a horizontal line (representing constant 
NO<INF>X</INF>), one crosses the lines of constant PM<INF>2.5</INF> 
(isopleths) into regions of increased PM<INF>2.5.</INF> The 2012 
PM<INF>2.5</INF> Plan presents similar diagrams for the various 
monitoring sites. 2012 PM<INF>2.5</INF> Plan, Chapter 4, Figures 4-
15 through 4-2334, pp. 4-31 to 4-40.
---------------------------------------------------------------------------

    The 2015 PM<INF>2.5</INF> Plan includes additional VOC vs. 
NO<INF>X</INF> isopleth diagrams from a 2005 Kleeman et al. paper.\133\ 
The key ones show that the effect of reducing VOC for all sources 
increases total PM<INF>2.5</INF> nitrate for any

[[Page 6950]]

given level of NO<INF>X</INF> emissions.\134\ The Plan states that the 
VOC disbenefit occurs because reducing VOCs can reduce the organic 
nitrate ``sink'' that makes nitrate unavailable, thus freeing it for 
ammonium nitrate formation.\135\
---------------------------------------------------------------------------

    \133\ Kleeman, M.K., Ying, Q., and Kaduwela, A., 2005, ``Control 
strategies for the reduction of airborne particulate nitrate in 
California's San Joaquin Valley'', Atmospheric Environment, 39: 
5325-5341 September 2005. doi: 10.1016/j.atmosenv.2005.05.044. This 
paper was discussed in our TSD for the 2008 PM<INF>2.5</INF> Plan, 
though the 2008 PM<INF>2.5</INF> Plan did not include the diagrams.
    \134\ WOEA, upper left quadrant of Figures 19 to 21, pp. A-32 to 
A-34.
    \135\ WOEA, pp. A-31, citing. Z. Meng, D. Dabdub, and J. H. 
Seinfeld, ``Chemical Coupling Between Atmospheric Ozone and 
Particulate Matter'', Science 277, 116 (1997); DOI: 10.1126/
science.277.5322.116. The Meng paper cites the organic nitrate sink 
as a possibility in PM chemistry. The Plan provides no direct 
evidence that this reaction is important in the SJV, though it is 
plausible.
---------------------------------------------------------------------------

    In sum, the information provided by the State and District in the 
Plan indicates that: (a) Wintertime levels of secondary organic aerosol 
measured in the SJV are low and therefore the direct products of VOC 
emissions do not contribute significantly to PM<INF>2.5</INF> levels 
above the standard in the SJV; and (b) wintertime reductions in VOC 
emissions in the SJV, when PM<INF>2.5</INF> concentrations are high, 
would not reduce ambient PM<INF>2.5</INF> levels, and therefore the 
indirect products of VOC emissions also do not contribute significantly 
to PM<INF>2.5</INF> 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 PM<INF>2.5</INF> levels that 
exceed the 1997 PM<INF>2.5</INF> NAAQS in the SJV nonattainment area.
e. Recommendations for Further Analyses
    The EPA believes that several precursor issues warrant further 
explanation and exploration in future PM<INF>2.5</INF> plans. For 
ammonia, an explanation should be provided for the apparent conflict 
between NO<INF>X</INF> as a ``limiting'' precursor for ammonium nitrate 
formation and modeling that nevertheless shows some benefits from 
ammonia emission reductions. In the 2012 PM<INF>2.5</INF> Plan, ammonia 
reductions for Kern County alone were simulated along with reductions 
for the area as a whole. Further exploration of the effect of more 
specific localized controls would inform decisions on whether ammonia 
controls should be part of the control strategy in the next 
PM<INF>2.5</INF> plan.
    For VOC, the apparent conflict between different past modeling 
studies on whether VOC emission reductions are beneficial or not also 
should be more fully explained. As mentioned above, and discussed 
further in the EPA's TSD for the 2012 PM<INF>2.5</INF> Plan,\136\ those 
studies showing a VOC benefit can be discounted on various grounds, but 
there does not appear to be a full explanation of the chemistry 
differences seen. Differences between the models used, their chemical 
mechanisms, their emissions and meteorological inputs, and the episodes 
they are applied to all cause differences in study results. Without a 
fuller reconciliation of those results, it is difficult to know whether 
or not chemistry sensitive to VOC reductions could still be operating 
today in the SJV. Also mentioned above, the Plan's WOEA asserts that 
background ozone levels are sufficient to provide the oxidants needed 
for nitrate formation, even without the VOC-mediated generation of 
ozone within the SJV.\137\ But little support has been provided for 
this assertion, other than similar assertions in a few journal papers. 
More concrete evidence on this issue should be provided in future 
plans.
---------------------------------------------------------------------------

    \136\ EPA Region 9, ``Technical Support Document, Proposed 
Action on the San Joaquin Valley 2012 PM<INF>2.5</INF> State 
Implementation Plan and 2014 Supplemental Document and Proposed 
Reclassification of the San Joaquin Valley as Serious Nonattainment 
for the 2006 PM<INF>2.5</INF> Standard,'' December 2014.
    \137\ WOEA, p. A-38.
---------------------------------------------------------------------------

    A related issue is why a VOC disbenefit occurs. One explanation is 
that VOC can remove nitrate via a ``sink'' reaction to organic 
nitrates, so reducing VOC frees nitrate to form PM<INF>2.5</INF>. This 
explanation is provided in a journal paper posing the nitrate sink as a 
possibility in PM chemistry. While this is plausible, no evidence has 
been provided from any studies during the ten years since the paper was 
published that this particular phenomenon is actually occurring in the 
SJV modeling or atmosphere. Some of these issues may be resolved 
through better documentation and explanation in the SIP submission of 
what is already known; others may require quantitative examination of 
particular chemical pathways in the modeling or ambient measurements.
    Evaluation of the available research and its implications for the 
effectiveness of various precursor emissions controls would also be 
useful as part of the next plan. This research includes projects funded 
by the San Joaquin Valley-wide Air Pollution Study Agency, including 
``Improve emission estimates for urban ammonia sources,'' ``Update of 
CRPAQS conceptual model and synthesis of results,'' and ``Develop 
Improvements to the PM<INF>2.5</INF> Inventory to Better Reconcile with 
Ambient Measurements.'' The CARB Staff Report refers to several recent 
field studies relevant for the SJV, including ARCTAS-CARB, CalNex2010, 
and DISCOVER-AQ, all of which should be examined for their implications 
for the SJV's atmospheric chemistry and the effectiveness of various 
precursor emissions controls.
    Some results from the CalNex study are already available in a 
Synthesis document.\138\ While CalNex was conducted during the summer 
of 2010, some of its findings may be relevant for PM<INF>2.5</INF> 
formation in the SJV, even though such formation is greatest in winter. 
Finding I2b (pp. 63-64) suggests that the SJV ammonia inventory is 
underestimated by a factor of three; if confirmed, this may have 
implications for modeling, the effectiveness of ammonia controls, and 
the amount of NO<INF>X</INF> used in the Plan to offset the ammonia 
inventory increases. Finding I3 (p. 65) highlights ammonia reactions 
with carboxylic acids and the resulting enhancement of secondary 
organic aerosol (SOA); the importance of this pathway in modeling 
winter PM<INF>2.5</INF> may need to be explored. Several other findings 
relate to SOA. Finding L2 (p. 75) stated significant SOA formation at 
night at Bakersfield. Finding N2 (p. 86) stated SOA as 72% of 
Bakersfield ultra-fine particulate matter (i.e., PM less than 1 
micrometer in diameter) (this contrasts with the 5% of PM<INF>2.5</INF> 
used in the Plan), and also stated that SOA dominated daytime particle 
growth. Findings W3a and W3b (p. 129) stated the importance of 
anthropogenic VOC as the main SOA precursor, and nitrate as a VOC 
oxidant. While many of these findings may be relevant mostly for summer 
conditions, their implications for chemical pathways and controls in 
winter should be examined.
---------------------------------------------------------------------------

    \138\ Synthesis of Policy Relevant Findings from the CalNex 2010 
Field Study (California Research at the Nexus of Air Quality and 
Climate Change): Final Report to the Research Division of the 
California Air Resources Board, David D. Parrish, NOAA Earth System 
Research Laboratory, March 27, 2014. Available at http://www.esrl.noaa.gov/csd/projects/calnex/.
---------------------------------------------------------------------------

3. Proposed Action
    Based on a review of the information provided in the 2015 
PM<INF>2.5</INF> Plan and other information available to the EPA, we 
propose to determine that at this time VOC emissions do not contribute 
significantly to ambient PM<INF>2.5</INF> levels which exceed the 1997 
annual and 24-hour PM<INF>2.5</INF> NAAQS in the SJV and, therefore, 
that VOCs may be excluded from the State's evaluation of potential 
control measures for purposes of these standards in this area. 
Consistent with the statutory requirements under subpart 4, all other 
PM<INF>2.5</INF> precursors (i.e., NO<INF>X</INF>, SO<INF>2</INF>, and 
ammonia) must be included in the State's evaluation of potential 
control measures for the 1997 PM<INF>2.5</INF> NAAQS in the SJV area, 
including nonattainment NSR provisions to

[[Page 6951]]

implement the requirements of subpart 4.\139\ We discuss the State's 
evaluation of potential control measures for NO<INF>X</INF>, 
SO<INF>2</INF>, and ammonia, as well as direct PM<INF>2.5</INF>, in 
section V.D. of this proposed rule.
---------------------------------------------------------------------------

    \139\ Absent a demonstration to EPA's satisfaction that major 
stationary sources of ammonia emissions do not contribute 
significantly to ambient PM<INF>2.5</INF> 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 PM<INF>2.5</INF>, 
including nonattainment NSR requirements. We intend to evaluate the 
adequacy of the District's nonattainment NSR program for 
PM<INF>2.5</INF> upon submission of the NSR SIP revision due May 7, 
2016, which is the date 12 months after EPA's reclassification of 
the SJV as Serious nonattainment for the 1997 PM<INF>2.5</INF> NAAQS 
became effective. 80 FR 18528 (April 7, 2015).
---------------------------------------------------------------------------

D. Best Available Control Measures and Most Stringent Measures

    As discussed in section IV.B of this proposed rule, section 
189(b)(1)(B) of the Act requires for any serious PM<INF>2.5</INF> 
nonattainment area that the State submit provisions to assure that the 
best available control measures (BACM) for reducing emissions of 
PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors will be implemented no 
later than four years after the date the area is reclassified as a 
serious area. Because the EPA reclassified the SJV area as Serious 
nonattainment for the 1997 PM<INF>2.5</INF> NAAQS effective May 7, 
2015, the date four years after reclassification is May 7, 2019. In 
this case, however, the Serious area attainment date for the SJV area 
under section 188(c) is no later than December 31, 2015, and to qualify 
for an extension of this date under section 188(e) the State must, 
among other things, demonstrate attainment by the most expeditious 
alternative date practicable. Given these circumstances, we are 
evaluating the Plan's control strategy for implementation of BACM as 
expeditiously as practicable.\140\
---------------------------------------------------------------------------

    \140\ CAA section 189(b)(1)(B) establishes an outermost deadline 
(``no later than four years after the date the area is 
reclassified'') and does not preclude an earlier implementation 
deadline for BACM where necessary to satisfy the attainment 
requirements of the Act.
---------------------------------------------------------------------------

    In addition, before the EPA may extend the attainment date for a 
Serious nonattainment area under CAA section 188(e), the State must, 
among other things, demonstrate to the satisfaction of the 
Administrator that the plan for the area includes the most stringent 
measures that are included in the implementation plan of any State or 
are achieved in practice in any State, and can feasibly be implemented 
in the area (MSM). As discussed above, we have established a process 
for evaluating BACM in serious area plans and a similar process for 
evaluating MSM. Because of the substantial overlap in the source 
categories and controls evaluated for BACM and those evaluated for MSM, 
we present our evaluation of the 2015 PM<INF>2.5</INF> Plan's 
provisions for including MSM alongside our evaluation of the Plan's 
provisions for implementing BACM for each identified source category. 
We provide a more detailed evaluation of many of the District's control 
measures for stationary and area sources in our ``Technical Support 
Document for the EPA's Evaluation of Fine Particulate Matter Best 
Available Control Measures and Most Stringent Measures for the San 
Joaquin Valley Air Pollution Control District,'' January 2016 (``SJV 
Rules TSD'').
1. Identifying the Sources of PM<INF>2.5</INF> and PM<INF>2.5</INF> 
Precursors
    The first step in determining BACM and MSM is to develop a detailed 
emissions inventory of the sources of direct PM<INF>2.5</INF> and 
PM<INF>2.5</INF> precursors that can be used with modeling to determine 
the effects of these sources on ambient PM<INF>2.5</INF> levels. The 
EPA's past guidance on Serious area plans in the Addendum suggested 
that the second step is to use modeling to identify those source 
categories that have a greater than de minimis impact on ambient 
PM<INF>2.5</INF> concentrations.\141\
---------------------------------------------------------------------------

    \141\ Addendum at 42012.
---------------------------------------------------------------------------

    As discussed in section V.A of this proposed rule, Appendix B of 
the 2015 PM<INF>2.5</INF> Plan contains the planning inventories for 
direct PM<INF>2.5</INF> and all PM<INF>2.5</INF> precursors 
(NO<INF>X</INF>, SO<INF>2</INF>, VOC, and ammonia) for the SJV 
PM<INF>2.5</INF> nonattainment area together with documentation to 
support these inventories. The District used available speciation data 
to identify de minimis thresholds, also referred to in the Plan as 
``significant emission levels,'' for direct PM<INF>2.5,</INF> 
NO<INF>X</INF>, and SO<INF>X</INF>.\142\ Based on these thresholds, 
which are described in Chapter 5 of the Plan, the District identified 
the following six source categories as emission sources in the SJV that 
emit pollutants at levels exceeding its selected de minimis thresholds 
(i.e., ``significant'' source categories):
---------------------------------------------------------------------------

    \142\ 2015 PM<INF>2.5</INF> Plan, Chapter 5, section 5.4 (``De 
Minimis Thresholds for Determining Significant Source Categories'').
---------------------------------------------------------------------------

    1. Open Burning;
    2. Glass Melting Furnaces;
    3. Agricultural Conservation Management Practices;
    4. Commercial Charbroiling;
    5. Wood Burning Fireplaces and Wood Burning Heaters; and
    6. Paved and Unpaved Roads.\143\
---------------------------------------------------------------------------

    \143\ Id. at Table 5-2 (``Valley Source Category De Minimis 
Determinations (using 2012 data)'').
---------------------------------------------------------------------------

    CARB identified most mobile source categories as ``significant'' 
and identified only several (e.g., cargo handling equipment, 
motorcycles, recreational boats, off-road recreational vehicles and 
commercial harbor craft) as de minimis source categories.\144\
---------------------------------------------------------------------------

    \144\ 2015 PM<INF>2.5</INF> Plan at Appendix D.
---------------------------------------------------------------------------

    Separately in Appendix C and Appendix D of the Plan, however, both 
CARB and the District identified all of the sources of direct 
PM<INF>2.5</INF>, NO<INF>X</INF>, SO<INF>X</INF> and ammonia in the SJV 
that are subject to State or District emission control measures and 
provided their evaluations of these regulations for compliance with 
BACM and MSM requirements. Table 3 identifies the source categories in 
SJV that are under State and District jurisdiction, each source 
category's 2012 emissions of direct PM<INF>2.5</INF>, NO<INF>X</INF>, 
and SO<INF>X</INF> in tons per day (tpd), and, for each source 
category, the regulations that the State and District have relied on in 
the Plan to satisfy BACM and MSM requirements.

                     Table 3--2015 PM2.5 Plan--Source Categories Evaluated for BACM and MSM
----------------------------------------------------------------------------------------------------------------
                                                                Rule No.    2012 PM2.5    2012 NOX     2012 SOX
                       Source category                         (if any) *     (tpd)        (tpd)        (tpd)
----------------------------------------------------------------------------------------------------------------
                        Stationary and Area Source Categories under District Jurisdiction
----------------------------------------------------------------------------------------------------------------
Open Burning................................................         4103         2.27         1.61         0.05
Reduction of Animal Matter..................................         4104         0.03         0.00         0.00
Prescribed Burning and Hazard Reduction Burning.............         4106         0.76         0.07         0.03
Particulate Matter Emissions from the Incineration of                4203         0.00         0.00         0.00
 Combustible Refuse.........................................
Cotton Gins.................................................         4204         0.22         0.00         0.00
Fuel Burning Equipment......................................         4301          N/A          N/A          N/A

[[Page 6952]]

 
Boilers, Steam Generators, and Process Heaters Greater than     4306/4320         1.27         1.93         0.60
 5.0 MMBtu/hr...............................................
Boilers, Steam Generators, and Process Heaters--2.0 to 5.0           4307         0.32         0.49         0.15
 MMBtu......................................................
Boilers, Steam Generators, and Process Heaters--0.075 to             4308         0.61         0.92         0.28
 less than 2.0 MMBtu........................................
Dryers, Dehydrators, and Ovens..............................         4309         0.85         0.20         0.47
Flares......................................................         4311         0.16         0.56         0.33
Lime Kilns..................................................         4313         0.00         0.00         0.00
Solid Fuel Fired Boilers, Steam Generators, and Process              4352         0.62         2.69         0.56
 Heaters....................................................
Glass Melting Furnaces......................................         4354         0.33         6.04         1.96
Conservation Management Practices...........................         4550
    <bullet> Tilling Dust...................................  ...........         5.17         0.00         0.00
    <bullet> Harvest Operations Dust........................  ...........         7.28         0.00         0.00
    <bullet> Dust from Ag Lands (non-pasture)...............  ...........         6.15         0.00         0.00
    <bullet> Dust from Pasture Lands........................  ...........         1.09         0.00         0.00
Commercial Charbroiling.....................................         4692         2.84         0.00         0.00
Internal Combustion Engines.................................         4702         0.49        13.06         0.12
Stationary Gas Turbines.....................................         4703         1.22         3.09         0.22
Sulfuric Acid Mist..........................................         4802         0.00         0.00         0.75
Wood Burning Fireplaces and Wood Burning Heaters............         4901         4.48         0.50         0.08
Residential Water Heaters...................................         4902         0.21         2.21         0.06
Natural Gas-Fired, Fan-Type Central Furnaces................         4905         0.20         2.46         0.06
General Requirements........................................         8011          N/A          N/A          N/A
Construction, Demolition, Excavation, Extraction, and Other          8021         1.46         0.00         0.00
 Earthmoving Activities.....................................
Bulk Materials..............................................         8031         0.04         0.00         0.00
Carryout and Trackout (emission included in Paved and                8041          N/A          N/A          N/A
 Unpaved Roads, Rule 8061, below)...........................
Open Areas..................................................         8051         0.34         0.00         0.00
Paved and Unpaved Roads.....................................         8061         7.59         0.00         0.00
Unpaved Vehicle/Equipment Traffic Areas.....................         8071         0.59         0.00         0.00
Agricultural Sources........................................         8081         1.21         0.00         0.00
Lawn and Garden Equipment...................................       SC 001         0.04         0.58         0.00
Energy Efficiency...........................................       SC 002          N/A          N/A          N/A
Fireworks...................................................       SC 003          N/A          N/A          N/A
Sand and Gravel Operations..................................       SC 004         0.09         0.00         0.00
Asphalt/Concrete Operations (Mineral Processes).............       SC 005         0.82         0.20         0.36
Almond Hulling/Shelling Operations..........................       SC 006         0.38         0.00         0.00
Pistachio Hulling/Shelling Operations (emissions included in       SC 007          N/A          N/A          N/A
 Almond Hulling/Shelling above).............................
Agricultural Material Screening/Shaking Operations                 SC 008          N/A          N/A          N/A
 (emissions included in other control categories)...........
Tub Grinding (emissions included in IC engines, Rule 4702,         SC 009          N/A          N/A          N/A
 fugitive emissions accounted for in stationary and area
 inventory).................................................
Abrasive Blasting...........................................       SC 010         0.33         0.00         0.00
----------------------------------------------------------------------------------------------------------------
                                Mobile Source Categories under State Jurisdiction
----------------------------------------------------------------------------------------------------------------
Light- and Medium-Duty Vehicles.............................         (**)          1.9         32.2        (***)
Heavy-Duty Vehicles.........................................         (**)          4.8        138.6        (***)
Off-Road Vehicles and Engines (excludes Cargo Handling               (**)          1.1         19.2        (***)
 Equipment).................................................
Farm Equipment..............................................         (**)          2.9         50.4        (***)
Cargo Handling Equipment....................................         (**)          0.0          0.1        (***)
Other Mobile Sources........................................         (**)  ...........  ...........        (***)
    <bullet> Motorcycles....................................  ...........          0.0          1.0
    <bullet> Recreational Boats.............................  ...........          0.4          1.6
    <bullet> Off-Road Recreational Vehicles.................  ...........          0.0          0.1
    <bullet> Commercial Harbor Craft........................  ...........          0.0          0.7
----------------------------------------------------------------------------------------------------------------
Source: 2015 PM2.5 Plan, Chapter 5, Table 5-2; Appendix C (``BACM and MSM for Stationary Sources''); and
  Appendix D (``BACM and MSM for Mobile Sources''), except as otherwise noted.
* ``SC'' refers to a source category that is subject to either several District rules or none.
** See 2015 PM2.5 Plan, Appendix D for a discussion of the State measures that cover these mobile source
  categories.
*** See 2015 PM2.5 Plan, Appendix B (Emissions Inventory) for SOX emission levels.

    With respect to ammonia, the District states in Appendix C of the 
2015 PM<INF>2.5</INF> Plan that ammonia is an ``insignificant'' 
PM<INF>2.5</INF> precursor in the SJV but also provides an analysis of 
several SIP-approved District regulations that control ammonia 
emissions.\145\ We provide our evaluation of these regulations below 
and further in the EPA's SJV Rules TSD.
---------------------------------------------------------------------------

    \145\ 2015 PM<INF>2.5</INF> Plan, Appendix C, at pp. C-239 to C-
280.
---------------------------------------------------------------------------

    Because the State and District have evaluated a much larger set of 
emission sources than those identified as ``significant'' sources in 
the Plan, and because the District's evaluation of de minimis 
thresholds entirely excludes consideration of ammonia emission

[[Page 6953]]

sources, the EPA is not proposing any action with respect to the 
District's selected de minimis thresholds for BACM and MSM purposes. 
Instead, based on the Plan's more comprehensive evaluation of State and 
District regulations that apply to stationary, area, and mobile sources 
of direct PM<INF>2.5,</INF> NO<INF>X</INF>, SO<INF>X</INF> and ammonia 
in the SJV, we propose to find that the 2015 PM<INF>2.5</INF> Plan 
appropriately identifies all emission sources and source categories 
that must be subject to evaluation for potential control measures 
consistent with the requirements of subpart 4.
2. Identification and Implementation of BACM and MSM
    As part of its process for identifying candidate BACM and MSM and 
considering the technical and economic feasibility of additional 
control measures, CARB and the District reviewed the EPA's guidance 
documents on BACM, guidance documents on control measures for direct 
PM<INF>2.5</INF>, NO<INF>X</INF>, and SO<INF>X</INF> emission sources, 
and control measures implemented in other ozone and PM<INF>2.5</INF> 
nonattainment areas in California and other states. The State's and 
District's evaluations of potential BACM and MSM for each source 
category identified in Table 3 above is found in Appendix C and 
Appendix D of the 2015 PM<INF>2.5</INF> Plan. In the following 
sections, we review key components of the State's and District's 
demonstrations concerning BACM and MSM for sources of direct 
PM<INF>2.5</INF>, NO<INF>X</INF>, SO<INF>X</INF> and ammonia emissions 
in the SJV. We provide a more detailed evaluation of the District's 
regulations in the EPA's SJV Rules TSD, together with recommendations 
for improvements to these rules.
    Based on our evaluation of these State and District demonstrations, 
we propose to determine that the 2015 PM<INF>2.5</INF> Plan provides 
for the implementation of BACM and MSM for sources of direct 
PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors as expeditiously as 
practicable, in accordance with the requirements of CAA sections 
189(b)(1)(B) and 188(e).
a. District Measures for Stationary and Area Sources
    The District's BACM and MSM process is described in the 2015 
PM<INF>2.5</INF> Plan, Chapter 5, section 5.3 (``BACM/MSM Evaluation 
Process'') and in Appendix C. The District followed a process similar 
to that used by Arizona in the Maricopa County PM<INF>10</INF> Serious 
Area Plan, the only other air quality plan in the nation that includes 
a BACM and MSM demonstration for purposes of requesting an attainment 
date extension under CAA section 188(e).\146\
---------------------------------------------------------------------------

    \146\ 65 FR 19964 (April 13, 2000) (proposed action on Maricopa 
County Serious Area Plan); 66 FR 50252 (October 2, 2001) (proposed 
action on Maricopa County Serious Area Plan); and 67 FR 48718 (July 
25, 2002) (final action on Maricopa County Serious Area Plan).
---------------------------------------------------------------------------

    For each identified source category, the District first identified 
potential control measures included in SIPs for other areas, addressed 
in federal regulations or guidance (e.g., control technique guidelines 
(CTGs), alternative control techniques (ACTs), or new source 
performance standards (NSPSs)), or addressed in state or local 
regulations or guidance (e.g., Air Toxic Control Measures (ATCMs).\147\ 
The District evaluated these identified potential control measures to 
determine whether implementation of the measures would be 
technologically and economically feasible in the SJV.\148\ In addition, 
the District considered other available control options (beyond those 
included in other SIPs or identified in federal/state regulations or 
guidance), such as measures that the State or District have previously 
considered ``beyond RACT'' and measures that have been implemented in 
practice in other areas. The District also evaluated these potential 
control measures to determine whether their implementation would be 
technologically and economically feasible in the SJV. The EPA's SJV 
Rules TSD provides a more detailed evaluation of many of these District 
regulations and our recommendations for rule improvements.
---------------------------------------------------------------------------

    \147\ 2015 PM<INF>2.5</INF> Plan, Chapter 5; and Appendix C, pp. 
C-4 to C-6.
    \148\ Id.
---------------------------------------------------------------------------

Open Burning
    SJVUAPCD Rule 4103 (``Open Burning''), as amended April 15, 2010, 
is designed to minimize impacts of smoke and other air pollutants from 
open burning of agricultural waste and other materials.\149\ The rule 
restricts the type of materials that may be burned and establishes 
other conditions and procedures for open burning in conjunction with 
the District's Smoke Management Program.\150\ The EPA approved this 
rule into the California SIP on January 4, 2012.\151\
---------------------------------------------------------------------------

    \149\ See generally SJVUAPCD Rule 4103, as amended April 15, 
2010; see also 2015 PM<INF>2.5</INF> Plan, Appendix C at pp. C-14 to 
C-15.
    \150\ Id.
    \151\ 77 FR 214 (January 4, 2012).
---------------------------------------------------------------------------

    The District compared Rule 4103 to several other open burning rules 
implemented in other parts of California and found no other rules more 
stringent as a whole than those in Rule 4103. According to the 
District, although the South Coast Air Quality Management District 
(SCAQMD) implements a rule that restricts burning on residential wood 
combustion (RWC) curtailment days (Rule 444) and District Rule 4103 
does not contain the same restriction, in practice the District 
currently bans all burning on RWC curtailment days through 
implementation of its Smoke Management Program, which specifically 
allocates allowable burn acreage for 103 geographic zones based on 
local meteorology.\152\ We note that a restriction on burning on RWC 
curtailment days by itself may not consistently reduce wintertime 
PM<INF>2.5</INF> emission levels as it could shift more waste burning 
activity to days with more favorable meteorology.
---------------------------------------------------------------------------

    \152\ 2015 PM<INF>2.5</INF> Plan, Appendix C at pp. C-8 to C-10.
---------------------------------------------------------------------------

    Sections 41855.5 and 41855.6 of the California Health and Safety 
Code require the District to prohibit open burning of specific crop 
categories unless the District determines either that there is no 
economically feasible alternative means of eliminating the waste or 
that there is no long-term federal or state funding commitment for the 
continued operation of biomass facilities in the SJV or for the 
development of alternatives to burning.\153\ The District has 
considered the technical and economic feasibility of alternatives to 
burning several times in the last several years and concluded that such 
alternatives are not feasible for selected crop categories at this 
time.\154\
---------------------------------------------------------------------------

    \153\ California Health & Safety Code, sections 41855.5 and 
41855.6.
    \154\ 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-8 to C-15.
---------------------------------------------------------------------------

Boilers, Steam Generators, and Process Heaters Greater Than 5.0 MMBtu/
hr
    SJVUAPCD Rule 4306 (``Boilers, Steam Generators, and Process 
Heaters--Phase 3''), as amended October 16, 2008, establishes 
NO<INF>X</INF> emission limits ranging from 5 to 30 ppm and related 
operational requirements for gaseous fuel- or liquid fuel-fired 
boilers, steam generators, and process heaters with total rated heat 
input greater than 5 million Btu per hour (MMBtu/hr).\155\ The EPA 
approved Rule 4306 into the California SIP on January 13, 2010.\156\ 
SJVUAPCD Rule 4320 (``Advanced Emission Reduction Options for Boilers, 
Steam Generators, and Process Heaters Greater Than 5.0 MMBtu/hr''), as 
adopted October 16, 2008, establishes more stringent NO<INF>X</INF> 
emission limits (5 to 12 ppm) and

[[Page 6954]]

related operational requirements for these units but allows sources to 
pay an emission fee in lieu of compliance with the NO<INF>X</INF> 
emission limits.\157\ The EPA approved Rule 4320 into the California 
SIP on March 25, 2011 but determined that this rule, as approved, may 
not be credited for attainment planning purposes because the fee 
provision renders the NO<INF>X</INF> emission limits 
unenforceable.\158\
---------------------------------------------------------------------------

    \155\ See generally SJVUAPCD Rule 4306, as amended October 16, 
2008; see also 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-35.
    \156\ 75 FR 1715 (January 13, 2010).
    \157\ See generally SJVUAPCD Rule 4320, as adopted October 16, 
2008; see also 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-35.
    \158\ 76 FR 16696 (March 25, 2011).
---------------------------------------------------------------------------

    The District compared both Rule 4306 and Rule 4320 to several other 
analogous rules implemented in other parts of California, including the 
Sacramento metropolitan area, the South Coast, and the Bay Area.\159\ 
According to the District, the NO<INF>X</INF> emission limits in Rule 
4306 are generally within the same range as, and in some cases are more 
stringent than, those contained in analogous rules implemented by these 
other California agencies, except that the SCAQMD implements a rule 
containing NO<INF>X</INF> emission limits that are potentially more 
stringent for units of certain sizes (SCAQMD Rule 1146, as amended 
November 1, 2013).\160\
---------------------------------------------------------------------------

    \159\ 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-38.
    \160\ Id.
---------------------------------------------------------------------------

    SCAQMD Rule 1146 establishes a 5 ppm NO<INF>X</INF> emission limit 
for larger units (i.e., those with heated rate inputs above 75 MMBtu/
hr), whereas Rule 4320 establishes a 7 ppm limit and Rule 4306 
establishes a 9 ppm limit for such units.\161\ SCAQMD Regulation XX 
(``Regional Clean Air Incentives Market'' or ``RECLAIM'') also applies 
to units within the same range of sizes as Rule 4320 but allows sources 
to comply with emission caps by purchasing RECLAIM Trading 
Credits.\162\ We do not have information about the rated heat input of 
the units subject to RECLAIM in the South Coast area and therefore 
cannot conclude that the lower NO<INF>X</INF> emission limits for 
larger boilers in SCAQMD Rule 1146 are technically and economically 
feasible for implementation in the SJV at this time.
---------------------------------------------------------------------------

    \161\ Compare SCAQMD Rule 1146 (as amended November 1, 2013) at 
section (c)(1)(F) to SJVUAPCD Rule 4320 at Table 1, category B.a and 
SJVUAPCD Rule 4306 at Table 1, category B; see also 2015 
PM<INF>2.5</INF> Plan, Appendix C, p. C-38.
    \162\ RECLAIM is a market incentive program designed to allow 
facilities flexibility in achieving emission reduction requirements 
for NO<INF>X</INF> and SO<INF>X</INF> through, among other things, 
add-on controls, equipment modifications, reformulated products, 
operational changes, shutdowns, and the purchase of excess emission 
reductions. See SCAQMD Rule 2000, section (a).
---------------------------------------------------------------------------

    The District also considered the technical and economic feasibility 
of alternative NO<INF>X</INF> and PM<INF>2.5</INF> control techniques 
for this source category, such as low temperature oxidation and 
EM<INF>X</INF> system for NO<INF>X</INF> control, and alternative 
fuels, electrostatic precipitators (ESP) and wet scrubbers for direct 
PM<INF>2.5</INF> control.\163\ Based on its consideration of the 
technical constraints and costs associated with each of these control 
options, the District concluded that these additional controls are not 
feasible for implementation in the SJV at this time.\164\
---------------------------------------------------------------------------

    \163\ 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-39.
    \164\ 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-42.
---------------------------------------------------------------------------

    Although the NO<INF>X</INF> emission limits in Rule 4320 do not 
satisfy the Act's enforceability requirements because of the option to 
pay an emission fee, we note that the requirement to pay the emission 
fee itself is an enforceable requirement and that the fee provision 
appears to function effectively as a pollution deterrent.\165\
---------------------------------------------------------------------------

    \165\ See section 3.b.5 of the EPA's SJV Rules TSD.
---------------------------------------------------------------------------

Flares
    SJVUAPCD Rule 4311 (``Flares''), as amended June 18, 2009, 
establishes specific operational and administrative requirements to 
limit emissions of NO<INF>X</INF>, SO<INF>X</INF>, and VOCs from the 
operation of flares.\166\ Under Rule 4311, for each refinery flare and 
other flare with a capacity above 5 MMBtu/hr, the operator must submit 
a flare minimization plan (FMP) to the District describing relevant 
equipment and preventative measures and demonstrating that the operator 
appropriately minimized flaring activity.\167\ The EPA approved Rule 
4311 into the California SIP on November 3, 2011.\168\
---------------------------------------------------------------------------

    \166\ See generally SJVUAPCD Rule 4311, as amended June 18, 
2009; see also 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-63.
    \167\ Id.
    \168\ 76 FR 68106 (November 3, 2011).
---------------------------------------------------------------------------

    The District compared Rule 4311 with several other analogous rules 
implemented in other parts of California, including the South Coast, 
Bay Area, Ventura County, and Santa Barbara, all of which require 
regulated sources to submit FMPs to the local districts.\169\ According 
to the District, most flares in the SJV occur in the oil and gas 
production industry and operate as emergency control devices, unlike 
many flares in the South Coast area and the Bay Area, which are 
significantly larger and operate as part of the refinery process.\170\ 
Because of wide variation in flaring operations in the SJV, the 
District concludes that requirements to submit details FMPs, as in Rule 
4311, are the most effective means of reducing NO<INF>X</INF> and 
SO<INF>X</INF> emissions from flaring.\171\
---------------------------------------------------------------------------

    \169\ 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-73.
    \170\ Id.
    \171\ Id.
---------------------------------------------------------------------------

    The District also considered the technical and economic feasibility 
of alternative control techniques for flares, such as maximum monthly 
flared gas targets and requirements to capture gas before it is 
flared.\172\ Based on its consideration of the technical constraints 
and costs associated with these control options, the District concluded 
that these additional controls are not feasible for implementation in 
the SJV at this time.\173\
---------------------------------------------------------------------------

    \172\ 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-82.
    \173\ 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-84.
---------------------------------------------------------------------------

    Chapter 8 of the 2015 PM<INF>2.5</INF> Plan includes a commitment 
by the District to conduct a comprehensive review of submitted FMPs to 
identify effective flare minimization practices; to evaluate the 
technical and economic feasibility of implementing new and additional 
flare minimization practices at affected facilities; to have a draft 
report available for public review and comment by December 1, 2015; to 
develop a final report by March 31, 2016 after addressing public 
comments on these evaluations; and upon completion of these analyses, 
to work closely with affected operators to ``evaluate and implement, 
when feasible, the most effective flare minimization practices through 
the FMP submittal and approval process under Rule 4311.'' \174\ The 
District issued its draft report of FMPs on December 3, 2015, starting 
a 30-day public comment period.\175\
---------------------------------------------------------------------------

    \174\ Id. at Chapter 8, Section 8.1 (pg. 8-2).
    \175\ SJVUAPCD, ``Draft Further Study, Rule 4311 Flare 
Minimization Plans, 2015,'' December 3, 2015.
---------------------------------------------------------------------------

Solid Fuel-Fired Boilers
    SJVUAPCD Rule 4352 (``Solid Fuel-Fired Boilers, Steam Generators, 
and Process Heaters''), as amended December 15, 2011, establishes 
NO<INF>X</INF> emission limits and related operational requirements for 
boilers, steam generators, and process heaters that burn municipal 
solid waste (MSW), biomass, and other solid fuels.\176\ Specifically, 
the rule establishes NO<INF>X</INF> emission limits of 165 ppmv for 
units burning MSW, 90 ppmv for units burning biomass, and 65 ppmv for 
units burning other solid fuels.\177\ The EPA approved this rule into 
the California SIP on November 6, 2012.\178\
---------------------------------------------------------------------------

    \176\ See generally SJVUAPCD Rule 4352, as amended December 15, 
2011; see also 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-87.
    \177\ Id.
    \178\ 77 FR 66548 (November 6, 2012).
---------------------------------------------------------------------------

    According to the District, the NO<INF>X</INF> emission limits in 
Rule 4352 have been lowered significantly over time and are

[[Page 6955]]

at least as stringent as analogous requirements implemented in other 
parts of California. The District compared the provisions of Rule 4352 
to potentially more stringent requirements implemented in Sacramento 
County, the South Coast area, and the Bay Area, but these comparisons 
are of limited value because no affected facilities are subject to the 
Sacramento Metropolitan Air Quality Management District's (SMAQMD) 
rule, and no sources are currently complying with the 40 ppmv limit in 
the SCAQMD's or Bay Area Air Quality Management District's (BAAQMD's) 
rules.\179\ Nonetheless, we note that three other air districts in 
California implement regulations that apply to active biomass-fueled 
units: Yolo-Solano Air Quality Management District (YSAQMD), El Dorado 
County Air Quality Management District (EDAQMD) and Placer County Air 
Pollution Control District (PCAPCD). The NO<INF>X</INF> emission limits 
in these regulations are all within the same range as SJVAPCD's limit 
of 90 ppm corrected to 3% O<INF>2</INF> on a 24-hour block 
average.\180\
---------------------------------------------------------------------------

    \179\ 2015 PM<INF>2.5</INF> Plan, Appendix C at p. C-89.
    \180\ SJV Rules TSD at Section 3.d.2. See also 77 FR 66548 
(November 6, 2012).
---------------------------------------------------------------------------

    The District also considered the technical and economic feasibility 
of alternative control techniques for this source category, such as 
selective catalytic reduction (SCR) for NO<INF>X</INF> control and ESPs 
or baghouses for direct PM<INF>2.5</INF> control.\181\ Based on its 
consideration of the costs associated with SCR retrofits at units 
burning biomass, MSW, or other solid fuels, the District concluded that 
SCR for these units is not economically feasible for sources in the SJV 
at this time.\182\ With respect to direct PM<INF>2.5</INF> control, the 
District states that sources subject to Rule 4352 are subject to permit 
limits that require the best feasible controls.\183\
---------------------------------------------------------------------------

    \181\ 2015 PM<INF>2.5</INF> Plan, Appendix C at pp. C-91 to C-
101.
    \182\ 2015 PM<INF>2.5</INF> Plan, Appendix C at pp. C-95--C-96 
and C-98.
    \183\ Id.
---------------------------------------------------------------------------

    We note that biomass- and MSW-fired units provide an environmental 
benefit by diverting these wastes from landfills and reducing open 
burning.
Glass Melting Furnaces
    SJVUAPCD Rule 4354 (``Glass Melting Furnaces''), as amended May 19, 
2011, establishes NO<INF>X</INF>, VOC, SO<INF>X</INF>, and 
PM<INF>10</INF> emission limits and related operational requirements 
for glass melting furnaces.\184\ Specifically, the rule establishes 
NO<INF>X</INF> emission limits of 1.5 to 3.7 lb. NO<INF>X</INF>/ton 
glass, depending on glass product and averaging time, and 
SO<INF>X</INF> emission limits of 0.9 to 1.7 lb. SO<INF>X</INF>/ton 
glass.\185\ The EPA approved Rule 4354 into the California SIP on 
January 31, 2013.\186\
---------------------------------------------------------------------------

    \184\ See generally SJVUAPCD Rule 4354, as amended May 19, 2011; 
see also 2015 PM<INF>2.5</INF> Plan, Appendix C at pp. C-102.
    \185\ SJVUAPCD Rule 4354, as amended May 19, 2011, at pp. 5 and 
7.
    \186\ 78 FR 6740 (January 31, 2013).
---------------------------------------------------------------------------

    According to the District, the NO<INF>X</INF> emission limits in 
Rule 4354 require implementation of oxy-fuel firing or SCR systems, 
which are the best available NO<INF>X</INF> control techniques, and are 
at least as stringent as analogous requirements implemented in the 
South Coast and Bay Area.\187\
---------------------------------------------------------------------------

    \187\ 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-102.
---------------------------------------------------------------------------

    We are not aware of prohibitory rules for glass melting furnaces in 
other areas that are more stringent than Rule 4354. We note that the 
SCAQMD has found a 1.2 lb./ton NO<INF>X</INF> emission limit feasible 
through a Best Available Retrofit Control Technology (BARCT) 
determination under its RECLAIM program, but absent information about 
how affected sources in the South Coast area have complied with the 
available compliance options under RECLAIM, it is not clear that these 
lower NO<INF>X</INF> emission levels are technically and economically 
feasible for implementation in the SJV.
Conservation Management Practices
    SJVUAPCD Rule 4550 (``Conservation Management Practices''), as 
adopted August 19, 2004, establishes requirements for owners and 
operators of agricultural sites to implement conservation management 
practices (CMPs) to control PM<INF>10</INF> emissions from on-field 
crop and animal feeding operations.\188\ Under the rule, each owner/
operator of an agricultural site must select and implement a CMP for 
each category of operations, including unpaved roads and unpaved 
vehicle/equipment traffic areas, and submit a CMP application to the 
District for its review and approval.\189\ The EPA approved this rule 
into the California SIP on February 14, 2006.\190\
---------------------------------------------------------------------------

    \188\ See generally SJVUAPCD Rule 4550, as adopted August 19, 
2004; see also 2015 PM<INF>2.5</INF> Plan, Appendix C at pp. C-106.
    \189\ Id.
    \190\ 71 FR 7683 (February 14, 2006).
---------------------------------------------------------------------------

    According to the District, Rule 4550 is the most stringent rule of 
its kind.\191\ The District compared the provisions of Rule 4550 to 
analogous requirements implemented by air agencies in other parts of 
California (Imperial County, South Coast, and Sacramento County) and in 
Arizona, and found no requirements more stringent than those in Rule 
4550.\192\ We note that it is difficult to directly compare the 
requirements among these rules because of the widely varying rule 
structures and operations of the affected agricultural sites.
---------------------------------------------------------------------------

    \191\ 2015 PM<INF>2.5</INF> Plan, Appendix C at pp. C-114.
    \192\ Id.
---------------------------------------------------------------------------

    The District also considered the technical and economic feasibility 
of additional control options for this source category, such as misting 
to reduce PM<INF>10</INF> emissions from disking activity and the use 
of new almond harvesting equipment.\193\ As to misting, the District 
found that the available information was not sufficient to demonstrate 
that this control technique would achieve its minimum standard of a 10% 
reduction in PM<INF>10</INF> emissions, so the District did not add 
this measure to the CMP list.\194\ As to the use of newer almond 
harvesting equipment, the District noted, based on a 2010-2011 study, 
that newer equipment would achieve significant PM<INF>10</INF> emission 
reductions but found it was not necessary to revise the CMP list given 
use of newer almond harvesting equipment is already listed under an 
existing CMP category.\195\ Finally, the District considered adding 
windblown dust controls to Rule 4550 but determined that such controls 
would not substantially impact PM<INF>2.5</INF> design values in the 
SJV because windblown dust events typically occur during the spring and 
fall seasons whereas the District asserts that PM<INF>2.5</INF> values 
are driven by winter-time concentrations; PM<INF>2.5</INF> values 
recorded during winter stagnation periods are usually much higher than 
those recorded during wind events; and the geologic component of peak 
PM<INF>2.5</INF> concentration is a fraction of the mass formed by 
secondary processes and other sources.\196\
---------------------------------------------------------------------------

    \193\ 2015 PM<INF>2.5</INF> Plan, Appendix C at pp. C-111.
    \194\ 2015 PM<INF>2.5</INF> Plan, Appendix C at pp. C-112.
    \195\ Id.
    \196\ 2015 PM<INF>2.5</INF> Plan, Appendix C at pp. C-110.
---------------------------------------------------------------------------

    Chapter 8 of the 2015 PM<INF>2.5</INF> Plan includes a commitment 
by the District to reevaluate Rule 4550, in close coordination with 
stakeholders (including agricultural industry representatives, CARB, 
and the EPA), for additional feasible control options; to have a draft 
report available for public review and comment by May 31, 2016; and to 
develop a final report by October 15, 2016 after addressing public 
comments on these evaluations.\197\
---------------------------------------------------------------------------

    \197\ Id. at Chapter 8, Section 8.3 (pg. 8-3).
---------------------------------------------------------------------------

Commercial Charbroiling
    SJVUAPCD Rule 4692 (``Commercial Charbroiling''), as amended 
September 17, 2009, establishes control

[[Page 6956]]

requirements to reduce PM<INF>10</INF> (of which PM<INF>2.5</INF> is a 
component) and VOC emissions from chain-driven charbroilers.\198\ 
Specifically, the rule requires that chain-driven charbroilers be 
equipped and operated with a catalytic oxidizer with a control 
efficiency of at least 83% for PM<INF>10</INF> emissions and 86% for 
VOC emissions.\199\ The EPA approved Rule 4692 into the California SIP 
on November 3, 2011.\200\
---------------------------------------------------------------------------

    \198\ See generally SJVUAPCD Rule 4692, as amended September 17, 
2009; see also 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-115.
    \199\ Id.
    \200\ 76 FR 68103 (November 3, 2011).
---------------------------------------------------------------------------

    The District compared the requirements in Rule 4692 to analogous 
requirements for chain-driven charbroilers implemented by the SCAQMD, 
Ventura County Air Pollution Control District (VCAPCD), and BAAQMD and 
found no requirements in these rules more stringent than those 
contained in Rule 4692, with one exception in the BAAQMD rule.\201\ 
With respect to under-fired charbroilers (UFCs), the District found 
that no cost-effective control techniques have been demonstrated to 
date given technical challenges associated with controlling emissions 
from UFCs, which operate differently from chain-driven 
charbroilers.\202\ Although the BAAQMD has adopted a rule that 
establishes control requirements for both chain-driven and under-fired 
charbroilers, according to the District, a significant portion of the 
UFCs in the BAAQMD are not subject to the rule's requirements for UFCs 
because they fall below the rule's applicability thresholds.\203\ The 
District also stated that the BAAQMD has been unable to enforce its UFC 
requirements because no control technologies have been certified.\204\
---------------------------------------------------------------------------

    \201\ 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-116 to C-
117.
    \202\ Id.
    \203\ Id.
    \204\ Id. at p. C-116.
---------------------------------------------------------------------------

    The District also considered the technical and economic feasibility 
of alternative control techniques for UFCs, such as catalytic 
oxidizers, high efficiency particulate-arresting filtration system, 
ESPs, and wet scrubbers.\205\ Based on its consideration of the 
technical difficulties and costs associated with installing these 
control devices at UFCs, the District concluded that these control 
techniques are not technically and economically feasible for sources in 
the SJV at this time.\206\ The District also stated, however, that it 
expects to begin testing some of these additional control options in 
mid-2015. The District's Governing Board approved $750,000 for its 
Restaurant Charbroiler Technology Partnership program, which would fund 
particulate emission control technology demonstration projects for 
under-fired charbroilers at restaurants in the SJV.\207\
---------------------------------------------------------------------------

    \205\ Id. at pp. C-117, C-118.
    \206\ 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-117 to C-
119.
    \207\ SJVUAPCD Governing Board, Meeting Minutes of June 18, 2015 
Governing Board Meeting, pp. 7-8.
---------------------------------------------------------------------------

    As part of the 2015 PM<INF>2.5</INF> Plan, the SJVUAPCD submitted a 
commitment to amend Rule 4692 in 2016 to add requirements for UFCs, 
with an anticipated compliance date of 2017.\208\ The Plan relies on 
this commitment for a portion of the direct PM<INF>2.5</INF> emission 
reductions needed to attain the 1997 PM<INF>2.5</INF> NAAQS.\209\
---------------------------------------------------------------------------

    \208\ 2015 PM<INF>2.5</INF> Plan, Appendix C at p. C-119 and 
SJVUAPCD Governing Board Resolution 15-4-7A (April 16, 2015) at 
paragraph 7.
    \209\ 2015 PM<INF>2.5</INF> Plan, CARB Staff Report, p. 9. See 
also 2015 PM<INF>2.5</INF> Plan, Chapter 7, section 7.1.2, p. 7-6, 
and Appendix C, section C.16, pp. C-115 to C-119, which describe the 
charbroiling rule revision commitment in the context of the 2015 
PM<INF>2.5</INF> Plan.
---------------------------------------------------------------------------

Internal Combustion Engines
    SJVUAPCD Rule 4702 (``Internal Combustion Engines''), as amended 
November 14, 2013, establishes NO<INF>X</INF>, CO, VOC, and 
SO<INF>X</INF> emission limits and related operational requirements for 
internal combustion (IC) engines.\210\ The rule contains separate 
emission limits for spark-ignited IC engines used in agricultural 
operations (SI AO engines), spark-ignited IC engines used in non-
agricultural operations (SI non-AO engines), and compression-ignited IC 
engines.\211\ The EPA proposed to approve this rule into the California 
SIP on December 2, 2015.\212\ The EPA approved a previous version of 
this rule into the California SIP on January 10, 2008.\213\
---------------------------------------------------------------------------

    \210\ See generally SJVUAPCD Rule 4702, as amended November 14, 
2013; see also 2015 PM<INF>2.5</INF> Plan, Appendix C at p. C-120.
    \211\ Id.
    \212\ 80 FR 75442 (December 2, 2015).
    \213\ 73 FR 1819 (January 10, 2008).
---------------------------------------------------------------------------

    For SI non-AO engines, Rule 4702 establishes NO<INF>X</INF> 
emission limits ranging from 25 to 75 ppmv.\214\ According to the 
District, these NO<INF>X</INF> emission limits are at least as 
stringent as many analogous control requirements implemented in the Bay 
Area, Sacramento Metro, and Ventura County areas.\215\ We also note 
that Rule 4702 limits are at least as stringent as analogous 
requirements in the Feather River, Placer County, Mojave Desert, and 
San Diego areas.\216\
---------------------------------------------------------------------------

    \214\ SJVUAPCD Rule 4702, as amended November 14, 2013, at Table 
1.
    \215\ 2015 PM<INF>2.5</INF> Plan, Appendix C at pp. C-122 to C-
123.
    \216\ Feather River AQMD Rule 3.22; Placer County APCD Rule 242; 
Mojave Desert AQMD Rule 1160; and San Diego APCD Rule 69.4.1.
---------------------------------------------------------------------------

    Some of the emission limits for SI non-AO engines in Rule 4702 are, 
however, less stringent than those implemented in the South Coast, El 
Dorado, and Antelope Valley areas for similar engines. Specifically, 
the SCAQMD has adopted an 11 ppmv limit for all IC engines; \217\ El 
Dorado has adopted a 25 ppmv limit for SI ``rich-burn'' engines and a 
65 ppmv limit for SI ``lean-burn'' engines (except those used 
exclusively in agricultural operations); \218\ and Antelope Valley has 
adopted a 36 ppmv limit for IC engines (except those used exclusively 
in agricultural operations).\219\ The District considered the technical 
and economic feasibility of alternative control techniques for SI non-
AO engines that would lower the emission levels for certain engines to 
11, 25, and 65 ppmv, but found that for reasons of both technical and 
economic feasibility, NO<INF>X</INF> emission limits lower than those 
in Rule 4702 are generally not feasible for implementation in the SJV 
at this time.\220\
---------------------------------------------------------------------------

    \217\ SCAQMD Rule 1110.2, as amended February 1, 2008.
    \218\ El Dorado County AQMD Rule 233, as amended June 2, 2006.
    \219\ Antelope Valley AQMD Rule 1110.2, as amended January 21, 
2003.
    \220\ See section 3.h (Internal Combustion Engines) of the EPA's 
SJV Rules TSD, which provides a more detailed discussion of the 
District's technical and economic feasibility analyses.
---------------------------------------------------------------------------

    For SI AO engines, Rule 4702 establishes NO<INF>X</INF> emission 
limits ranging from 90 to 150 ppmv.\221\ These NO<INF>X</INF> emission 
limits are more stringent than analogous control requirements 
implemented in the Sacramento Metro, Placer County, El Dorado, and 
Antelope Valley areas, which exempt AO engines from control 
requirements altogether, and are equivalent to analogous control 
requirements implemented in the Mojave Desert area.\222\ The SCAQMD, 
however, has adopted an 11 ppmv limit for all IC engines,\223\ and the 
BAAQMD has adopted NO<INF>X</INF> emission limits ranging from 25-70 
ppmv for all spark-ignited IC engines.\224\ Thus, Rule 4702's

[[Page 6957]]

requirements for SI AO engines are at least as stringent as most but 
not all analogous requirements implemented in other parts of 
California.
---------------------------------------------------------------------------

    \221\ SJVUAPCD Rule 4702, as amended November 14, 2013, at Table 
3.
    \222\ SMAQMD Rule 412, as amended June 1, 1995; Placer County 
APCD Rule 242, as adopted April 10, 2003; El Dorado County AQMD Rule 
233, as amended June 2, 2006; Antelope Valley AQMD Rule 1110.2, as 
amended January 21, 2003; and Mojave Desert AQMD Rule 1160.1, as 
adopted January 23, 2012.
    \223\ SCAQMD Rule 1110.2, as amended February 1, 2008.
    \224\ Bay Area AQMD Regulation 9, Rule 8, as amended July 25, 
2007.
---------------------------------------------------------------------------

    The District considered the technical and economic feasibility of 
alternative control techniques for SI AO engines that would lower their 
emission levels and found that for reasons of both technical and 
economic feasibility, NO<INF>X</INF> emission limits lower than those 
in Rule 4702 are generally not feasible for implementation within SJV's 
agricultural industry at this time.\225\ We note that the SCAQMD, like 
SJVUAPCD, has provided economic incentive grants for agricultural 
engine retrofits and replacement in recognition of unique economic and 
technical circumstances in the agricultural industry.\226\
---------------------------------------------------------------------------

    \225\ See section 3.h (Internal Combustion Engines) of the EPA's 
SJV Rules TSD.
    \226\ SCAQMD Final Staff Report for Rule 1110.2, May 2005, 
Appendix B: Incentive Funding Available for Agricultural Engine 
Emission Reductions.
---------------------------------------------------------------------------

    Finally, for compression-ignited IC engines (both those used in 
agricultural operations and those used in non-agricultural operations), 
Rule 4702 requires that all certified engines meet the EPA's Tier 3 and 
Tier 4 emission standards for nonroad diesel engines and that non-
certified engines meet the same standards or a numerical NO<INF>X</INF> 
emission limit based on engine size.\227\
---------------------------------------------------------------------------

    \227\ SJVUAPCD Rule 4702, as amended November 14, 2013, at Table 
4.
---------------------------------------------------------------------------

Stationary Gas Turbines
    SJVUAPCD Rule 4703 (``Stationary Gas Turbines''), as amended 
September 20, 2007, establishes NO<INF>X</INF> emission limits ranging 
from 5 to 25 ppm and related operational requirements for all 
stationary gas turbines with greater than 0.3 MW capacity.\228\ These 
units operate primarily in the oil and gas production and utility 
industries, with some also operating in manufacturing and government 
facilities.\229\ The EPA approved this rule into the California SIP on 
October 21, 2009.\230\
---------------------------------------------------------------------------

    \228\ SJVUAPCD Rule 4703, as amended September 20, 2007, at 
Table 5-3.
    \229\ 2015 PM<INF>2.5</INF> Plan, Appendix C at p. C-142.
    \230\ 74 FR 53888 (October 21, 2009).
---------------------------------------------------------------------------

    According to the District, the NO<INF>X</INF> emission limits in 
Rule 4703 are more stringent than analogous control requirements 
implemented in many other parts of California, including the Sacramento 
Metro area, South Coast, and Ventura County.\231\ The District 
considered the technical and economic feasibility of alternative 
control techniques to reduce emissions further, such as the 
installation of SCR or installation of entirely new turbine systems, 
and concluded that these options are extremely expensive and not 
economically feasible.\232\ The District also considered the potential 
for installation of EMx system for NO<INF>X</INF> control and concluded 
that this technology requires further testing before it will be 
generally available for implementation in the SJV.\233\
---------------------------------------------------------------------------

    \231\ 2015 PM<INF>2.5</INF> Plan, Appendix C at p. C-144.
    \232\ Id.
    \233\ Id.
---------------------------------------------------------------------------

Wood Burning Fireplaces and Wood Burning Heaters
    SJVUAPCD Rule 4901 (``Wood Burning Fireplaces and Wood Burning 
Heaters''), as amended September 18, 2014, is designed to limit 
emissions of PM, including PM<INF>2.5</INF> and PM<INF>10</INF>, and 
other pollutants generated by the use of wood burning fireplaces, wood 
burning heaters, and outdoor wood burning devices. The rule establishes 
requirements for the sale/transfer, operation, and installation of wood 
burning devices and on the advertising of wood for sale within the 
SJV.\234\ The EPA proposed to approve this rule into the SIP on 
September 30, 2015.\235\
---------------------------------------------------------------------------

    \234\ See generally SJVUAPCD Rule 4901, as amended September 18, 
2014.
    \235\ 80 FR 58637 (September 30, 2015). Also, EPA approved a 
previous version of Rule 4901, as adopted October 16, 2008, into the 
SIP on November 10, 2009 (74 FR 57907).
---------------------------------------------------------------------------

    Rule 4901 includes a mandatory two-tiered curtailment program. 
During a Level One Episodic Wood Burning Curtailment, which is declared 
when the PM<INF>2.5</INF> concentration is forecasted to be between 20-
65 [micro]g/m\3\, operation of wood burning fireplaces and unregistered 
wood burning heaters is prohibited, but properly operated wood burning 
heaters that meet certification requirements and have a current 
registration with the District may be used. During a Level Two Episodic 
Wood Burning Curtailment, which is declared when the PM<INF>2.5</INF> 
concentration is forecasted to be above 65 [micro]g/m\3\ or the 
PM<INF>10</INF> concentration is forecasted to be above 135 [micro]g/
m3, operation of any wood burning device is prohibited.\236\
---------------------------------------------------------------------------

    \236\ SJVUAPCD Rule 4901, as amended September 18, 2014, at 
paragraph 5.6.
---------------------------------------------------------------------------

    According to SJVAPCD, Rule 4901 is at least as stringent as 
analogous rules in other areas, including the South Coast, Bay Area, 
Sacramento Metro area, Washoe County, Nevada, and Washington 
State.\237\ We note that SCAQMD Rule 445 includes a mandatory 
curtailment of all devices when the 24-hour average PM<INF>2.5</INF> 
concentration is forecasted above 30 [micro]g/m\3\, and SMAQMD Rule 421 
bans operation of all wood burning devices when ambient 
PM<INF>2.5</INF> concentrations are above 35 [micro]g/m\3\. According 
to the District, however, the small increase in emissions from 
registered clean burning devices when concentrations are between 20-65 
[micro]g/m\3\ in the SJV will be more than offset by the decrease in 
emissions from dirty devices when concentrations are between 20-30 
[micro]g/m\3\, which will reduce the build-up of emissions during long 
periods of stagnation experienced in the wintertime in the Valley.\238\
---------------------------------------------------------------------------

    \237\ 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-156.
    \238\ Rule 4901 Staff Report, p. 19.
---------------------------------------------------------------------------

    Rule 4901 incorporates all elements outlined in the EPA's 
Strategies for Reducing Wood Smoke \239\ and includes comparable 
provisions available in other analogous rules. We are not aware of more 
stringent measures for reducing residential wood smoke that are 
technically and economically feasible for implementation in the SJV. 
Our Technical Support Document to support our separate proposal on Rule 
4901 contains a more detailed discussion of this rule in comparison to 
analogous rules implemented elsewhere.\240\
---------------------------------------------------------------------------

    \239\ ``Strategies for Reducing Residential Wood Smoke,'' EPA-
456/B-13-001, March 2013.
    \240\ U.S. EPA Region 9, ``Technical Support Document for EPA's 
Proposed Rulemaking for the California State Implementation Plan 
(SIP), San Joaquin Valley Unified Air Pollution Control District 
Rule 4901 Wood Burning Fireplaces and Wood Burning Heaters,'' August 
2015. See also section 3.f (Conservation Management Practices) of 
the EPA's SJV Rules TSD.
---------------------------------------------------------------------------

Paved and Unpaved Roads
    SJVUAPCD Rule 8061 (``Paved and Unpaved Roads''), as amended August 
19, 2004, is designed to limit fugitive dust emissions generated from 
paved and unpaved roads. The rule establishes control measures and 
design criteria for existing public and private paved or unpaved roads, 
road construction projects, and road modification projects, such as 
requirements to stabilize unpaved roads by applying water, a uniform 
layer of washed gravel, chemical/organic dust stabilizers/suppressants, 
paving, or any other method demonstrated to effectively limit visible 
dust to 20% opacity.\241\ The EPA approved this rule into the SIP on 
February 17, 2006.\242\
---------------------------------------------------------------------------

    \241\ SJVUAPCD Rule 8061, as amended August 19, 2004, at section 
5.2.1.
    \242\ 71 FR 8461 (February 17, 2006).
---------------------------------------------------------------------------

    The District compared Rule 8061 to SCAQMD Rule 1156 (``Further 
Reductions of Particulate Emissions from Cement Manufacturing 
Facilities''); SCAQMD Rule 1157 (``PM-10 Emission Reductions from 
Aggregate and Related Operations''); SMAQMD Rule 403 (``Fugitive 
Dust''); VCAPCD Rule 55 (``Fugitive Dust''); Clark County

[[Page 6958]]

Department of Air Quality Section 91 (``Fugitive Dust from Unpaved 
Roads, Unpaved Alleys, and Unpaved Easement Roads''), and Section 93 
(``Fugitive Dust from Paved Roads and Street Sweeping 
Equipment'').\243\ Based on these evaluations, SJVUAPCD concluded that 
no other areas implemented requirements more stringent than those 
already in Rule 8061.
---------------------------------------------------------------------------

    \243\ 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-194 to C-
197.
---------------------------------------------------------------------------

    The District also considered the feasibility of requiring control 
measures on paved and unpaved roads with less than 26 annual average 
daily trips (AADT). Such a measure would require more road owners/
operators to implement control measures to reduce fugitive emissions 
from paved and unpaved roads. SJVUAPCD's analysis of the emission 
inventory indicates that the majority of the particulate emissions 
attributable to unpaved roads are from roads with more than 26 AADT. 
Because these roads are already subject to the mitigation requirements 
of Rule 8061, the District concluded that the remaining emissions from 
unpaved roads with less than 26 AADT provide very little opportunity 
for additional emissions reductions. Additionally, the District noted 
that emissions from unpaved roads are lowest in the winter months, when 
exceedances of the 24-hour PM<INF>2.5</INF> standard tend to occur. For 
these reasons, SJVUAPCD concluded that additional control measures for 
paved and unpaved road with less than 26 AADT would not achieve 
emission reductions.\244\
---------------------------------------------------------------------------

    \244\ Id. at p. C-196.
---------------------------------------------------------------------------

Asphalt/Concrete Operations
    SJVUAPCD Rule 4101 (``Visible Emissions''), as amended February 17, 
2005, establishes limits on opacity, which is often used as an 
indicator of PM emissions. SJVUAPCD Rule 4309 (``Dryers, Dehydrators, 
and Ovens''), as amended December 15, 2005, establishes NO<INF>X</INF> 
and CO emission limits for dryers, dehydrators and ovens firing gaseous 
or liquid fuel with a total rated heat input of at least 5.0 MMBtu/hr. 
Under Rule 4309, asphalt/concrete manufacturing plants that operate 
equipment of this size are subject to NO<INF>X</INF> emission limits of 
4.3 ppm (gaseous fuel) and 12.0 ppm (liquid fuel).\245\ The EPA 
approved Rule 4101 into the California SIP on August 11, 2005 \246\ and 
approved Rule 4309 into the California SIP on May 30, 2007.\247\
---------------------------------------------------------------------------

    \245\ SJVUAPCD Rule 4309, as adopted December 15, 2005, at p. 5.
    \246\ 70 FR 46770 (August 11, 2005).
    \247\ 72 FR 29886 (May 30, 2007).
---------------------------------------------------------------------------

    According to the District, there are no state regulations that 
apply to this source category and no analogous rules in the Bay Area, 
Sacramento Metro, or Ventura County areas.\248\ The District evaluated 
analogous rules implemented in the South Coast and found no 
requirements more stringent than those in SJVUAPCD Rule 4101 and Rule 
4309.\249\ We are not aware of more stringent control requirements for 
visible emissions or NO<INF>X</INF> emissions in other California 
districts for asphalt plants.
---------------------------------------------------------------------------

    \248\ 2015 PM<INF>2.5</INF> Plan at Appendix C, pp. C-219, C-
220.
    \249\ Id. (citing SCAQMD Rule 1157 and Rule 403).
---------------------------------------------------------------------------

    The District also considered the technical and economic feasibility 
of using warm mix asphalt (WMA), a newer substance which is produced at 
temperatures 25 to 90 degrees (Fahrenheit) lower than hot mix asphalt 
(HMA) and which results in lower emissions because it requires less 
fuel to heat the asphalt. Although the use of WMA has grown steadily in 
the U.S., the District concluded that use of WMA at asphalt production 
facilities in the SJV is not technically and economically feasible at 
this time given the high costs of, and technical difficulties 
associated with, converting equipment.\250\
---------------------------------------------------------------------------

    \250\ Id. at pp. C-221, C-225.
---------------------------------------------------------------------------

    Chapter 8 of the 2015 PM<INF>2.5</INF> Plan includes a commitment 
by the District to evaluate and promote the use of WMA in the SJV, in 
close coordination with stakeholders (including asphalt plant 
operators, Caltrans, city and county planning agencies, CARB, and the 
EPA); to have a draft report available for public review and comment by 
December 1, 2015; and to develop a final report by March 31, 2016, 
after addressing public comments. As part of this evaluation, the 
District committed to (1) evaluate opportunities to further encourage 
transportation and county agencies to continue transitioning from HMA 
to WMA as feasible, (2) to explore the potential feasibility of 
additional control measures and the granting of mitigation credits for 
WMA usage through the District's Indirect Source Review (ISR) program, 
and (3) to consider outreach and education opportunities for 
encouraging project developers and construction managers to increase 
the use of WMA.\251\ The District issued its draft report on WMA on 
December 1, 2015, starting a 30-day public comment period.\252\
---------------------------------------------------------------------------

    \251\ Id. at Chapter 8, Section 8.2, p. 8-3.
    \252\ SJVUAPCD, ``Draft Further Study, Warm Mix Asphalt,'' 
December 1, 2015.
---------------------------------------------------------------------------

Confined Animal Facilities (CAFs)
    SJVUAPCD Rule 4570 (``Confined Animal Facilities''), as amended 
October 21, 2010, applies to large dairy, poultry, beef cattle feeding 
and swine CAFs and requires operators of such facilities to implement 
measures to control VOC emissions for each major stage of operation, 
e.g., feeding, silage, milking (dairy), housing, waste management, and 
waste storage/application.\253\ According to the District, although 
Rule 4570 was developed to limit VOC emissions, the work practice 
standards contained in the rule also reduce ammonia emissions--for 
example through mitigation measures for nutritional management, 
increased cleaning and removal of manure and litter from housing areas, 
and land incorporation of manure and litter.\254\ The EPA approved Rule 
4570 into the California SIP on January 17, 2012.\255\
---------------------------------------------------------------------------

    \253\ See generally Rule 4570, as amended October 21, 2010; see 
also 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-240.
    \254\ 2015 PM<INF>2.5</INF> Plan at Appendix C, p. C-241.
    \255\ 77 FR 2228 (January 17, 2012).
---------------------------------------------------------------------------

    The District compared the requirements of Rule 4570 with those in 
analogous prohibitory rules implemented in other areas, including the 
South Coast, Bay Area, Sacramento Metro, Ventura County, Imperial 
County, and the State of Idaho, and concluded that Rule 4570 is more 
stringent than all of these rules.\256\ For example, Rule 4570 contains 
applicability thresholds that are more stringent than those in 
analogous rules implemented in the South Coast (Rule 233) and Idaho 
(Rule 58.01.01).\257\ We note that it is difficult to directly compare 
the requirements among these rules because of the widely varying rule 
structures and operations of confined animal facilities.
---------------------------------------------------------------------------

    \256\ 2015 PM<INF>2.5</INF> Plan at Appendix C, pp. C-236 to C-
267.
    \257\ Id.
---------------------------------------------------------------------------

    The District also considered the technical and economic feasibility 
of alternative control techniques for CAFs, including episodic 
application of sodium bisulfate (SBS) on manure at dairies, which 
converts a greater fraction of ammonia to non-volatile ammonium.\258\ 
Given the costs of SBS application and its potential adverse impacts on 
worker safety and health, cattle health, and water quality, the 
District concluded that SBS application this control option is not 
technically and economically feasible for implementation in the SJV at 
this time.\259\ The District also evaluated the use of covers to reduce 
ammonia from

[[Page 6959]]

lagoons and solid manure storage piles and found no definitive evidence 
that such techniques would reduce ammonia emissions. To the contrary, 
the District stated, several studies indicated that anaerobic lagoon 
covers might increase ammonia emissions.\260\
---------------------------------------------------------------------------

    \258\ Id. at pg. C-267.
    \259\ Id.
    \260\ Email dated June 25, 2015, from Sheraz Gill, SJVUAPCD to 
Andy Steckel, EPA, re: Requested Information, and attachments.
---------------------------------------------------------------------------

Compost Operations
    SJVUAPCD Rule 4565 (``Biosolids, Animal Manure, and Poultry Litter 
Operations''), as adopted March 15, 2007, establishes requirements for 
facilities that landfill, land apply, compost, or co-compost biosolids, 
animal manure, or poultry litter.\261\ SJVUAPCD Rule 4566 (``Organic 
Material Composting''), as adopted August 18, 2011, establishes 
requirements for facilities that stockpile and compost greenwaste and 
foodwaste materials.\262\ According to the District, although both of 
these rules were designed to control VOC emissions, both rules 
establish work practice standards that have the co-benefit of reducing 
ammonia emissions.\263\ The EPA approved Rules 4565 and 4566 into the 
California SIP on January 17, 2012 \264\ and November 29, 2012,\265\ 
respectively.
---------------------------------------------------------------------------

    \261\ See generally SJVUAPCD Rule 4565, as adopted March 15, 
2007; see also 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-276.
    \262\ See generally SJVUAPCD Rule 4566, as adopted August 18, 
2011; see also 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-272.
    \263\ 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-272 and C-
276.
    \264\ 77 FR 2228 (January 17, 2012).
    \265\ 77 FR 71129 (November 29, 2012).
---------------------------------------------------------------------------

    The District compared the requirements of Rule 4565 and Rule 4566 
with those in an analogous prohibitory rule implemented in the South 
Coast area (Rule 1133.2) and found that the SCAQMD rule requires in-
vessel composting with 70% to 80% control efficiency for existing and 
new facilities, respectively, while SJVUAPCD Rule 4565 requires 10% to 
80% control efficiency based on annual throughput.\266\ According to 
the District, however, the lower control efficiencies required by 
SJVUAPCD Rule 4565 are appropriate because in-vessel composting is not 
cost-effective for smaller or medium-sized facilities, and SCAQMD does 
not regulate any facilities of the size that is subject to the 80% 
control requirement.\267\ Moreover, the District states that Rule 4565 
contains a more stringent applicability threshold (100 tpy of 
biosolids, animal manure or poultry litter) compared to the 
applicability threshold in SCAQMD Rule 1133.2 (1,000 tpy VOC).\268\
---------------------------------------------------------------------------

    \266\ 2015 PM<INF>2.5</INF> Plan, Appendix C at pp. C-272, C-
273.
    \267\ Id.
    \268\ Id.
---------------------------------------------------------------------------

    The District also considered the technical and economic feasibility 
of alternative control techniques for compost operations, including 
finished compost covers and water systems, but found that these control 
techniques are not technically and economically feasible for compost 
operations in the SJV at this time.\269\ The District also noted that 
it has funded a project through its Technology Advancement Program that 
could potentially reduce ammonia and other emissions at large 
greenwaste and/or foodwaste composting facilities--specifically, an 
``extended aerated stack pile (eASP) method'' which substitutes diesel-
powered loaders with electronic conveyor systems to build piles, uses 
solar-powered blowers to replace diesel-powered windrow turners, and 
uses finished compost biofilter covers.\270\ According to the District, 
the study authors note that this demonstration project is the first 
test of this technology and recommend further testing and evaluation to 
assure results on an industry-wide basis.\271\ We note that there are 
other environmental benefits associated with composting operations, 
including diversion of material from landfills, which should be 
considered in evaluating the feasibility of additional controls for 
this source category.
---------------------------------------------------------------------------

    \269\ Id. at pp. C-275 to C-276 and C-279.
    \270\ 2015 PM<INF>2.5</INF> Plan, Appendix E, p. E-15.
    \271\ Id.
---------------------------------------------------------------------------

b. State Measures for Mobile Sources
    CARB's BACM and MSM demonstration for mobile sources is in Appendix 
D of the 2015 PM<INF>2.5</INF> Plan. CARB has primary responsibility 
for reducing emissions in California from new and existing on-road and 
off-road engines and vehicles, motor vehicle fuels, and consumer 
products. Given the need for significant emissions reductions from 
mobile sources to meet the NAAQS in California nonattainment areas, 
CARB has been a leader in the development of stringent control measures 
for on-road and off-road mobile sources, fuels and consumer 
products.\272\
---------------------------------------------------------------------------

    \272\ The Plan does not address CARB's consumer products program 
because it is primarily designed to reduce emissions of VOCs, which 
the State has excluded from its control strategy for attaining the 
PM<INF>2.5</INF> NAAQS in the SJV.
---------------------------------------------------------------------------

    Under the Clean Air Act, the EPA is charged with establishing 
national emission limits for mobile sources. States are generally 
preempted from establishing such limits except for California, which 
can establish these limits subject to EPA waiver or authorization under 
CAA section 209 (referred to herein as ``waiver measures''). Over the 
years, the EPA has issued waivers (for on-road vehicles and engines 
measures) or authorizations (for non-road vehicle and engine measures) 
\273\ for many mobile source regulations adopted by CARB.\274\ 
California attainment and maintenance plans, including the 2015 
PM<INF>2.5</INF> Plan for the SJV, rely on emissions reductions from 
implementation of the waiver measures through the use of emissions 
models such as EMFAC2014.
---------------------------------------------------------------------------

    \273\ California regulations use the term ``off-road'' to refer 
to ``nonroad'' vehicles and engines.
    \274\ The Clean Air Act assigns mobile source regulation to EPA 
through title II of the Act and assigns stationary source regulation 
and SIP development responsibilities to the states. In so doing, the 
CAA preempts various types of state regulation of mobile sources as 
set forth in section 209(a) (preemption of state emissions standards 
for new motor vehicles and engines), section 209(e) (preemption of 
state emissions standards for nonroad vehicles and engines), and 
section 211(c)(4)(A) [preemption of state fuel requirements for 
motor vehicles, i.e., other than California's motor vehicle fuel 
requirements--see section 211(c)(4)(B)]. For certain types of mobile 
source standards, the State of California may request a waiver or 
authorization for state emission standards.
     CAA section 209(b)(1) and (e)(2) give California unique 
authority under the CAA to regulate emissions from new motor 
vehicles and nonroad engines, except for locomotives and engines 
used in farm and construction equipment less than 175 horsepower. To 
exercise its authority, California must obtain a waiver from EPA 
demonstrating that the standards, in the aggregate, are at least as 
protective of public health and welfare as applicable federal 
standards. Additionally, EPA must grant a waiver unless California's 
``protectiveness determination'' is arbitrary and capricious; 
California does not need the standards to meet compelling and 
extraordinary conditions; or California's standards and accompanying 
enforcement procedures are not consistent with CAA Sec.  202(a). EPA 
has previously stated that consistency with section 202(a) requires 
that California's standards must be technologically feasible within 
the lead time provided, giving due consideration of costs. See, 
e.g., 74 FR 32767 (July 8, 2009) regarding the greenhouse gas 
waiver. Once a waiver is granted, compliance with California's new 
motor vehicle or engine standards is treated as compliance with 
applicable federal standards. In the absence of a waiver, the 
applicable federal mobile source standards apply.
---------------------------------------------------------------------------

    Historically, California has not submitted, and the EPA has not 
required that California submit, its mobile source rules that have been 
granted a waiver or authorization by the EPA for inclusion in the 
California SIP. However, a recent decision by the Ninth Circuit Court 
of Appeals held that the EPA's longstanding practice in this regard was 
at odds with the CAA requirement that state and local emissions limits 
relied upon to meet the NAAQS be enforceable by the EPA or private 
citizens through

[[Page 6960]]

adoption and approval of such limits in the SIP.\275\
---------------------------------------------------------------------------

    \275\ Committee for a Better Arvin v. EPA, 786 F.3d 1169 (9th 
Cir. 2015).
---------------------------------------------------------------------------

    In response to the Court's ruling, CARB has submitted its mobile 
source control rules that have been granted waivers or authorizations 
but have not been included in the SIP, and, in a separate rulemaking, 
the EPA has proposed to approve these rules into the SIP.\276\ Upon the 
EPA's final approval of these rules into the SIP, which the EPA intends 
to complete before or concurrent with final action on the 2015 
PM<INF>2.5</INF> Plan, the measures will be enforceable by the EPA or 
private citizens under the CAA.
---------------------------------------------------------------------------

    \276\ 80 FR 69915 (November 12, 2015).
---------------------------------------------------------------------------

    In addition to waiver measures, CARB has adopted operational 
requirements for in-use vehicles, rules that limit the amounts of 
pollutants allowed in transportation fuels, and incentive programs that 
provide funding to replace or retrofit older, dirtier vehicles and 
equipment with cleaner technologies.\277\
---------------------------------------------------------------------------

    \277\ 2015 PM<INF>2.5</INF> Plan, Appendix D, pp. D-9 to D-11.
---------------------------------------------------------------------------

    The EPA previously determined that California's mobile source 
control programs constituted BACM for PM<INF>10</INF> purposes in the 
San Joaquin Valley.\278\ Since then, the State has adopted additional 
mobile source control measures including the Advanced Clean Cars 
program, heavy-duty vehicle idling rules, revisions to the State's 
vehicle inspection and maintenance (I/M) program, in-use rules for on-
road and non-road diesel vehicles, and emissions standards for non-road 
equipment, farm and cargo handling equipment, and recreational 
vehicles.\279\
---------------------------------------------------------------------------

    \278\ 69 FR 5412 at 5419 (February 4, 2004).
    \279\ 2015 PM<INF>2.5</INF> Plan, Appendix D, pages D-4 to D-19.
---------------------------------------------------------------------------

    CARB's BACM and MSM analysis provides a discussion of the measures 
adopted and implemented for each of the identified source categories. 
We discuss each of these mobile source categories below.
Light and Medium Duty Vehicles
    This category includes light-duty passenger cars, light-duty 
trucks, and medium-duty trucks. The source category's emissions are 
32.2 tpd NO<INF>X</INF> and 1.9 tpd direct PM<INF>2.5</INF>.\280\
---------------------------------------------------------------------------

    \280\ 2015 PM<INF>2.5</INF> Plan, Appendix D, p. D-5.
---------------------------------------------------------------------------

    CARB has a long history of adopting programs for reducing emissions 
from this source category. Light-duty and medium-duty motor vehicles 
are currently subject to California's ``Low-Emission Vehicle III'' (LEV 
III) standards as well as a ``Zero Emission Vehicle'' (ZEV) 
requirement. The LEV III standards are consistent, or harmonized, with 
the subsequently adopted national Tier 3 standards for the same 
vehicles. California's ZEV program, however, does not have a national 
counterpart and results in additional emissions reductions as it phases 
in a requirement that 15% of new light-duty vehicle sales consist of 
ZEV or partial ZEV.\281\ Taken as a whole, California's standards for 
light and medium-duty vehicles are more stringent than the federal 
standards.
---------------------------------------------------------------------------

    \281\ 78 FR 2112 at 2119 (January 9, 2013).
---------------------------------------------------------------------------

    California has also adopted regulations for gasoline fuel 
(California Reformulated Gasoline or CaRFG) which reduce emissions from 
light-duty and medium-duty vehicles. On July 10, 2009, the EPA approved 
the CaRFG regulations into the California SIP.\282\
---------------------------------------------------------------------------

    \282\ 74 FR 33196 (July 10, 2009).
---------------------------------------------------------------------------

Heavy-Duty Vehicles
    This category includes heavy-duty gas and diesel trucks, heavy-duty 
gas and diesel urban buses, school buses and motor homes. The emissions 
from this category are 130.6 tpd NO<INF>X</INF> and 4.8 tpd direct 
PM<INF>2.5</INF>.\283\
---------------------------------------------------------------------------

    \283\ 2015 PM<INF>2.5</INF> Plan, Appendix D, p. D-8.
---------------------------------------------------------------------------

    California has the most stringent heavy-duty vehicle emissions 
control measures in the nation, including engine standards for diesel 
and gasoline vehicles, idling requirements, certification procedures, 
on-board diagnostic requirements, and verification measures for 
emissions control devices. Many of these control measures are subject 
to the CAA waiver process and have also been submitted for inclusion in 
the SIP.\284\
---------------------------------------------------------------------------

    \284\ 2015 PM<INF>2.5</INF> Plan, Appendix D, p. D-8 to D-12. 
See also 80 FR 69915 (November 12, 2015).
---------------------------------------------------------------------------

    California has also adopted many in-use requirements to help reduce 
emissions from the vehicles already on the road, which may remain in 
use for many years. The most recently adopted in-use requirement is the 
Cleaner In-Use Heavy-Duty Trucks measure (``Truck and Bus Regulation 
and Drayage Truck Regulation''), which became effective in 2011 and the 
EPA approved into the SIP in 2012.\285\ The Truck and Bus Regulation 
and Drayage Truck Regulation are designed to reduce emissions of diesel 
particulate matter, NO<INF>X</INF>, and other pollutants from in-use 
trucks and buses and establish, among other things, phased-in PM 
control requirements from 2014 through 2023.
---------------------------------------------------------------------------

    \285\ 77 FR 20308, April 4, 2012.
---------------------------------------------------------------------------

    Finally, California has adopted regulations for diesel fuel that 
further reduce emissions from heavy-duty trucks. The EPA approved these 
diesel fuel regulations into the California SIP on July 10, 2009.\286\
Off-Road Vehicles and Engines
    This category includes off-road compression ignition (diesel) 
engines and equipment, small spark ignition (gasoline) off-road engines 
and equipment less than 25 horsepower (hp) (e.g., lawn and garden 
equipment), off-road large gasoline engines and equipment greater than 
25 hp (e.g., forklifts, portable generators), and airport ground 
service equipment. The emissions from this category total 19.2 tpd 
NO<INF>X</INF> and 1.1 tpd direct PM<INF>2.5</INF>.\287\
---------------------------------------------------------------------------

    \287\ 2015 PM<INF>2.5</INF> Plan, Appendix D, pp. D-12 to D-14.
---------------------------------------------------------------------------

    As it has done for the on-road categories discussed above, CARB has 
adopted stringent new emissions standards subject to EPA authorization 
under CAA section 209(e) and in-use measures or requirements for this 
source category (e.g., incentives for early introduction of cleaner 
engines and equipment and requirements to limit vehicle idling). CARB 
has been regulating off-road equipment since the 1990s and its new 
engine standards for off-road vehicles and engines are generally as 
stringent as the corresponding federal standards. For larger off-road 
equipment, which can have a slow turnover rate, CARB adopted an in-use 
off-road regulation in 2007 that requires owners of off-road equipment 
in the construction and other industries to retrofit or replace older 
engines/equipment with newer, cleaner models. The off-road regulation 
also imposes idling limitations.\288\
---------------------------------------------------------------------------

    \288\ Id.
---------------------------------------------------------------------------

Farm Equipment
    The farm equipment category includes agricultural equipment such as 
tractors, harvesting equipment and sprayers. The category's emissions 
are 50.4 tpd NO<INF>X</INF> and 2.9 tpd PM<INF>2.5</INF>. CARB has 
adopted standards identical to the EPA's standards for this off-road 
engine category. CARB notes also that State, District, and federal 
incentive funds have resulted in the replacement of over 3,000 pieces 
of agricultural equipment earlier than required by state and federal 
regulations.\289\
---------------------------------------------------------------------------

    \289\ 2015 PM<INF>2.5</INF> Plan, Appendix D, pp. D-15.
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Other Mobile Source Categories
    Other mobile source categories identified by CARB in the Plan 
include cargo handling equipment, motorcycles, recreational boats, off-
road recreational vehicles and commercial harbor craft. The emissions 
from all of these

[[Page 6961]]

categories total 3.5 tpd NO<INF>X</INF> and 0.5 tpd direct 
PM<INF>2.5</INF>. Although CARB considers these categories 
``insignificant'' for BACM purposes in the 2015 PM<INF>2.5</INF> Plan, 
CARB provided a discussion of the emission standards and other measures 
it has adopted to control emissions from these categories.\290\
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    \290\ 2015 PM<INF>2.5</INF> Plan, Appendix D, pp. D-15 to D-18.
---------------------------------------------------------------------------

c. Local Jurisdiction Transportation Control Measures (TCMs)
    TCMs are, in general, measures designed to reduce emissions from 
on-road motor vehicles through reductions in vehicle miles traveled or 
traffic congestion. TCMs can reduce PM<INF>2.5</INF> emissions in both 
the on-road motor vehicle exhaust and paved road dust source categories 
by reducing vehicle miles traveled (VMT) and vehicle trips. They can 
also reduce vehicle exhaust emissions by relieving congestion. EPA 
guidance states that where mobile sources contribute significantly to 
PM<INF>2.5</INF> violations, ``the state must, at a minimum, address 
the transportation control measures listed in CAA section 108(f) to 
determine whether such measures are achievable in the area considering 
energy, environmental and economic impacts and other costs.'' \291\
---------------------------------------------------------------------------

    \291\ Addendum at 42013.
---------------------------------------------------------------------------

    The current efforts by the SJV's eight local jurisdiction 
metropolitan planning organizations (MPO) \292\ to implement cost-
effect transportation control measures (TCM) are described in Chapter 
6.5.6 of the 2015 PM<INF>2.5</INF> Plan.\293\ The Plan includes a 
discussion of the on-going implementation of a broad range of TCMs in 
the Valley. There is also a discussion of the MPOs' Congestion 
Management and Air Quality (CMAQ) funding policy, which is a 
standardized process across the Valley for distributing 20% of the CMAQ 
funds to projects that meet a minimum cost-effectiveness.\294\
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    \292\ These eight MPOs represent the eight counties in the San 
Joaquin Valley air basin: The San Joaquin Council of Governments, 
the Stanislaus Council of Governments, the Merced County Association 
of Governments, the Madera County Transportation Commission, the 
Council of Fresno County Governments, Kings County Association of 
Governments, the Tulare County Association of Governments and Kern 
Council of Governments.
    \293\ 2015 PM<INF>2.5</INF> Plan, Chapter 6.5.6, p. 6-19.
    \294\ For an example of the CMAQ funding policy implemented by 
the eight SJV MPOs, see ``Resolution To Adopt The Local Cost-
Effectiveness Congestion Mitigation And Air Quality (CMAQ) Program 
Policy,'' San Joaquin Council Of Governments (SJCOG), R-08-03, July 
26, 2007,'' and ``Exhibit A, Local Cost-Effectiveness CMAQ Policy,'' 
SJCOG.
---------------------------------------------------------------------------

    Each Valley MPO is required to update its Regional Transportation 
Plan (RTP) at least once every four years.\295\ The RTP is a long-term 
regional transportation plan that provides a vision for transportation 
investments throughout the Valley. To further illustrate the eight SJV 
MPOs' commitment to the implementation of TCMs, the RTPs contain a host 
of improvements to the regional multimodal transportation system 
including: Active transportation (e.g., biking and walking), 
transportation demand management, transportation system management, 
transit, passenger rail, goods movement, aviation and airport ground 
access, highways, arterials, and operations and maintenance. Included 
within these transportation system improvements are TCM projects that 
reduce vehicle use or change traffic flow or congestion conditions, 
such as: Improved transit, high occupancy vehicle lanes, traffic flow 
improvements, park and ride lots, ridesharing/trip reduction programs, 
and bicycle/pedestrian facilities.\296\ These projects are listed in 
each MPO's conformity analysis for the 2014 RTP and 2015 Federal 
Transportation Improvement Program (FTIP).\297\ The FTIP is a four-year 
spending plan that lists every transportation project that will receive 
federal funds or that is subject to a federally required action, such 
as a review and approval of environmental documents.
---------------------------------------------------------------------------

    \295\ 23 CFR 450.322(c)
    \296\ See, e.g., Fresno Council of Government's Conformity 
Analysis for 2014 RTP and Sustainable Community Strategy, adopted 
June 26, 2014, Appendix D, Timely Implementation Documentation for 
Transportation Control Measures. The 2014 RTP is combined with the 
Sustainable Communities Strategy to integrate land use and 
transportation planning to achieve, where feasible, regional 
greenhouse gas (GHG) targets set by the CARB pursuant to Senate Bill 
375, which identifies specific GHG reduction goals for each of 
California's MPOs in 2020 and 2035.
    \297\ Id.
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    The SJV has a long history of adopting and then enhancing programs 
to reduce emissions from on-road motor vehicles by reducing vehicle 
miles traveled, vehicle trips, and/or congestion. For example, Rule 
9410 (``Employer Based Trip Reduction'' or ``eTRIP''), requires larger 
employers to establish an Employer Trip Reduction Implementation Plan 
to encourage employees to reduce single-occupancy vehicle trips, thus 
reducing emissions, including PM<INF>2.5</INF> and NO<INF>X</INF>, 
associated with work commutes.\298\ The MPOs implement public outreach 
programs to encourage people to reduce driving, programs to improve 
bicycling and pedestrian travel, and an extensive program to 
synchronize traffic lights.
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    \298\ EPA, Final rule, ``Approval and Promulgation of 
Implementation Plans; California; San Joaquin Valley Unified Air 
Pollution Control District; Employer Based Trip Reduction 
Programs,'' pre-publication notice signed December 11, 2015; see 
also 80 FR 51153 (August 24, 2015) (proposed rule).
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    In our approval of California's Serious area plan for the 1987 
PM<INF>10</INF> NAAQS in the SJV \299\ (``2003 PM<INF>10</INF> Plan''), 
we determined that the measures in the ``Regional Transportation 
Planning Agency Commitments for Implementation Document'' (April 2002) 
\300\ satisfied the PM<INF>10</INF> BACM requirement for TCMs.\301\ In 
May 2003, the San Joaquin Valley MPO Executive Directors committed to 
conduct feasibility analyses as part of each successive RTP in support 
of the 2003 PM<INF>10</INF> Plan. The MPOs retained this commitment in 
the PM<INF>10</INF> maintenance plan for the SJV area adopted September 
20, 2007.\302\ In accordance with their commitment and in preparation 
for their 2014 RTPs, the MPOs reviewed several PM<INF>10</INF> Plans 
adopted in other areas since 2009.\303\ From their reviews, the MPOs 
concluded no additional on-road fugitive dust controls measures were 
available for consideration. In consultation with CARB and the 
District, however, the MPOs considered priority funding allocations in 
the 2014 RTPs for PM<INF>10</INF> and NO<INF>X</INF> emission reduction 
projects for the measures listed below.
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    \299\ SJVUAPCD, ``2003 PM<INF>10</INF> Plan, San Joaquin Valley 
Plan to Attain Federal Standards for Particulate Matter of 10 
Microns and Smaller,'' submitted August 19, 2003 as amended by 
subsequent submission of December 30, 2003.
    \300\ SJVUAPCD, ``Regional Transportation Planning Agency 
Commitments for Implementation Document,'' April 2002.
    \301\ 69 FR 30006 at 30020, 30035 (May 26, 2004).
    \302\ SJVUAPCD, ``2007 PM<INF>10</INF> Maintenance Plan and 
Request for Redesignation,'' submitted November 16, 2007. Chapter 7, 
p. 21.
    \303\ PM<INF>10</INF> Plans reviewed included: Puerto Rico, 
Municipality of Guaynabo, PM<INF>10</INF> Limited Maintenance Plan; 
Nogales, AZ, PM<INF>10</INF> Attainment Demonstration; Coso 
Junction, CA, PM<INF>10</INF> Maintenance Plan, May 17, 2010; 
Sacramento, CA, PM<INF>10</INF> Implementation/Maintenance Plan, 
October 28, 2010; Truckee Meadows, NV, PM<INF>10</INF> Maintenance 
Plan, May 2009; and Eagle River, AK, PM<INF>10</INF> Maintenance 
Plan, adopted August 2010.

<bullet> Paving or Stabilizing Unpaved Roads and Alleys
<bullet> Curbing, Paving, or Stabilizing Shoulders on Paved Roads
<bullet> Frequent Routine Sweeping or Cleaning of Paved Roads (i.e., 
funding allocation for the purchase of PM<INF>10</INF> efficient street 
sweepers for member jurisdictions); and
<bullet> Repave or Overlay Paved Roads with Rubberized Asphalt.\304\
---------------------------------------------------------------------------

    \304\ See, e.g., Fresno Council of Government's Conformity 
Analysis for 2014 RTP and Sustainable Community Strategy, adopted 
June 26, 2014, Chapter 4, Section E, p. 42.

    In their implementation of the Congestion Mitigation and Air 
Quality (CMAQ) Improvement Program, the SJV MPOs evaluate and 
prioritize the

[[Page 6962]]

reduction of PM<INF>10</INF> emissions in the CMAQ scoring criteria. 
The MPOs continue to implement the adopted San Joaquin Valley CMAQ 
Policy, which was included in the District's plan for the 1997 ozone 
NAAQS \305\ and the 2008 PM<INF>2.5</INF> Plan. The CMAQ policy 
includes a standardized process for distributing 20% of the CMAQ funds 
to projects that meet a minimum cost effectiveness beginning in fiscal 
year 2011. This policy focuses on achieving the most cost effective 
emissions reductions, while maintaining flexibility to meet local 
needs. The 2015 FTIP includes a listing of all transportation-related 
projects requiring federal funding or other approval by the federal 
transportation agencies. The aggregate funding allocated \306\ for TCMs 
in the eight SJV 2015 FTIPs includes:
---------------------------------------------------------------------------

    \305\ SJVUAPCD, ``2007 Ozone Plan,'' April 30, 2007, which EPA 
approved on March 1, 2012. (78 FR 12652).
    \306\ Source: 2015 PM<INF>2.5</INF> Plan, Chapter 6, Figure 6-2 
Illustration of Valley MPO Funding for Sample TCM Categories, p. 6-
20. The funding in the 2015 FTIPs covers the federal fiscal years 
(i.e., October 1-September 30) 2014/2015 through 2017/2018. An 
example 2015 FTIP, the 2015 Federal Transportation Improvement 
Program, Fresno Council of Governments, is included in the docket 
for today's action and available at http://www.fresnocog.org/sites/default/files/publications/FTIP/2015_FTIP/FINAL_2015_FTIP_8-13-14.pdf.

<bullet> Improved transit; ($928,000,000)
<bullet> traffic flow improvements ($499,381,000)
<bullet> park and ride lots; ($2,666,346)
<bullet> ridesharing/trip reduction programs; ($7,630,000)
<bullet> bicycle/pedestrian facilities ($6,650,000)
3. Conclusion
    Based on all of these evaluations, we propose to find that the 2015 
PM<INF>2.5</INF> Plan provides for the implementation of BACM and MSM 
for sources of direct PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors 
as expeditiously as practicable, in accordance with the requirements of 
CAA sections 189(b)(1)(B) and 188(e).

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

    Section 188(e) of the Act allows the EPA to extend the attainment 
date for a serious area for up to five years if attainment by the 
applicable date is impracticable. However, before we may grant an 
extension of the attainment date, the State must first:
    (1) Apply to the EPA for an extension of the PM<INF>2.5</INF> 
attainment date beyond 2015,
    (2) demonstrate that attainment by 2015 is impracticable,
    (3) have complied with all requirements and commitments applying to 
the area in its implementation plan,
    (4) demonstrate to our satisfaction that its serious area plan 
includes the most stringent measures that are achieved in practice in 
any state and are feasible for the area, and
    (5) submit SIP revisions containing a demonstration of attainment 
by the most expeditious alternative date practicable.
    We evaluate the 2015 PM<INF>2.5</INF> Plan's compliance with each 
of these requirements below.
1. Application for an Attainment Date Extension
    As discussed in section IV.D of this proposed rule, for the SJV, 
the Serious area attainment date for the 1997 PM<INF>2.5</INF> NAAQS 
under CAA section 188(c)(2) is December 31, 2015. The first criterion 
of an extension of the attainment date beyond this statutory attainment 
date is that the State must apply for such extension. In the 2015 
PM<INF>2.5</INF> Plan, CARB and SJVUAPCD submit a complete application 
for an extension of the Serious area attainment date for the SJV to 
December 31, 2020 for the 1997 annual PM<INF>2.5</INF> standard and to 
December 31, 2018 for the 1997 24-hour PM<INF>2.5</INF> standard.\307\
---------------------------------------------------------------------------

    \307\ 2015 PM<INF>2.5</INF> Plan: CARB Resolution 15-9, May 21, 
2015 (submitting the Plan to EPA as a SIP revision); SJVAPCD, 
Governing Board Resolution 15-4-7A, paragraph 1 (adopting the 2015 
PM<INF>2.5</INF> Plan); and Chapter 4, p. 4-1.
---------------------------------------------------------------------------

2. Demonstration That Attainment by Serious Area Attainment Date Is 
Impracticable
    Despite the implementation of BACM as expeditiously as practicable, 
as discussed in section V.D. above, the 2015 PM<INF>2.5</INF> Plan 
shows that attainment by the Serious area attainment date is 
impracticable. We discuss below the air quality data that support the 
State's and District's demonstration of impracticability.
    Chapter 4, Section 4.1 of the 2015 PM<INF>2.5</INF> Plan presents 
data showing that the SJV area cannot attain the 1997 PM<INF>2.5</INF> 
annual and 24-hour standards by December 31, 2015.\308\ Specifically, 
the District provided ambient PM<INF>2.5</INF> air quality data from 
monitoring sites in the SJV, including 2013 measured concentrations and 
2014 measured and estimated concentrations, and then calculated the 
maximum 2015 annual average and 24-hour concentrations for each 
monitoring site that would result in a 3-year average PM<INF>2.5</INF> 
concentration of 15.0 [micro]g/m\3\ (i.e., annual design value), and 3-
year average 98th percentile concentration of 65 [micro]g/m\3\ (i.e., 
24-hour design value), at each monitoring site. The District states 
that several of the maximum allowable 2015 concentrations are so low, 
and in one instance a negative number, that attaining the standards by 
December 31, 2015 is impracticable.\309\ A separate analysis is 
presented for the annual and 24-hour standards and we have evaluated 
each with respect to demonstrating impracticability of attaining the 
1997 PM<INF>2.5</INF> NAAQS.
---------------------------------------------------------------------------

    \308\ 2015 PM<INF>2.5</INF> Plan, Chapter 4, pp. 4-1 to 4-5.
    \309\ Id. at pp. 4-3 to 4-5.
---------------------------------------------------------------------------

    The annual average value for a given year is calculated using the 
quarterly average concentrations for that year, while the 24-hour value 
for a given year is calculated using the 98th percentile of 24-hour 
average concentrations for that year.\310\ At the time the District 
compiled monitoring data for this purpose in January 2015, actual 
PM<INF>2.5</INF> measurements were available for 2013 and most of 2014 
from the EPA's Air Quality System (AQS) database. For the remainder of 
the 2014 data, preliminary monitoring measurements were used for the 
latter portion of 2014 and, for four of the 16 monitors used in the 
analysis, the District used 2013 4th quarter data for the 2014 4th 
quarter data, since the 2014 filter data from those monitors were not 
yet available.\311\
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    \310\ 40 CFR 50, Appendix N, sections 4.4 and 4.5, respectively.
    \311\ 2015 PM<INF>2.5</INF> Plan, Chapter 4, Table 4-1, p. 4-4.
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Impracticability of Attaining the 1997 Annual PM<INF>2.5</INF> Standard 
by December 31, 2015
    According to the District, the maximum 2015 annual average 
concentration at the Bakersfield-Planz site (which recorded the area's 
highest annual average in 2013, and is estimated to have the highest 
annual average in 2014) that will enable the site to show a design 
value at or below 15.0 [micro]g/m\3\ for 2015 is negative 2.4 [micro]g/
m\3\.\312\ In addition, the District calculates that the Hanford, 
Visalia-Church, and Bakersfield-California monitoring sites (which are 
in the three southern-most counties in the SJV) would have to each 
average under 10 [micro]g/m\3\, and states that such concentrations are 
unlikely given historical PM<INF>2.5</INF> concentrations in the 
SJV.\313\ Based on these preliminary data and analyses, the 2015 
PM<INF>2.5</INF> Plan concludes that it is impracticable for the 
Hanford, Visalia-Church, Bakersfield-California, and Bakersfield-Planz 
monitoring sites, to show an annual PM<INF>2.5</INF> NAAQS design value 
at or below 15.0 [micro]g/m\3\ by December 31, 2015.
---------------------------------------------------------------------------

    \312\ Id.
    \313\ Id. at p. 4-4.
---------------------------------------------------------------------------

    The EPA independently evaluated 2013 and 2014 PM<INF>2.5</INF> air 
quality data

[[Page 6963]]

that had been uploaded to AQS as of June 30, 2015, and as of January 
20, 2016, to assess the District's representations.\314\ Table 4 shows 
the annual average PM<INF>2.5</INF> concentrations that were recorded 
in 2013 and 2014 and that the EPA estimated for 2015 at selected 
monitoring sites. The average annual concentrations in 2013 and 2014 
were higher than in 2012, and in several cases the 2013 and 2014 values 
were significantly higher than the 2012 value, especially at the 
Bakersfield-Planz monitoring site, whose annual average concentrations 
for 2013 and 2014 were each over 20 [micro]g/m\3\.\315\ Based on the 
annual average concentrations observed in 2013 and 2014, the EPA 
calculated the maximum annual average concentration for seven 
monitoring sites that would enable each site to show a 2015 annual 
average PM<INF>2.5</INF> design value at or below 15.04 [micro]g/
m\3\.\316\
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    \314\ See Section III (``Analysis of Practicability of 
Attainment'') and Appendix A (``Data Worksheets for Analysis of 
Practicability of Attainment'') of the EPA's General TSD.
    \315\ The 2015 PM<INF>2.5</INF> Plan cites weather conditions 
associated with the extreme drought in California, including low 
precipitation, high stagnation, and strong inversions, among the 
reasons for the high PM<INF>2.5</INF> concentrations observed in the 
winter of 2013-2014. See 2015 PM<INF>2.5</INF> Plan, Chapter 4, pp. 
4-2 to 4-3 and 4-5.
    \316\ The small differences between the District's and EPA's 
calculations of ``maximum 2015'' values are due to EPA's use of 
certified, rather than preliminary, 2014 data and different rounding 
conventions. EPA's calculations of maximum 2015 values are based on 
the rounding convention in 40 CFR part 50, appendix N, which 
provides that intermediate calculations are not rounded, and that a 
design value with a decimal lower than 15.05 [micro]g/m\3\ is 
rounded down to 15.0 [micro]g/m\3\. See 40 CFR part 50, appendix N, 
section 4.3. In computing the maximum 2015 concentration consistent 
with attainment and consistent with 2013 and 2014 annual mean 
concentrations, EPA did not round the 2013 and 2014 means in the 
intermediate steps of the calculation, and used 15.04 [micro]g/m\3\ 
as the highest design value consistent with the standard. In 
contrast, the calculations presented in the 2015 PM<INF>2.5</INF> 
Plan rounded the 2013 and 2014 means to one decimal place initially, 
and used 15.00 [micro]g/m\3\ as the highest attaining design value.
---------------------------------------------------------------------------

    The EPA found that four monitoring sites located in the three 
southern-most counties of the SJV would have to have 2015 annual mean 
concentrations 35% or more below their corresponding historical lows in 
order to attain by the end of 2015.\317\ The most extreme example is 
the Bakersfield-Planz Rd. monitoring site, which would require 
approximately 95% below the previously recorded low.
---------------------------------------------------------------------------

    \317\ See section III and Appendix A of the EPA's General TSD.

  Table 4--2013 and 2014 Annual Average PM2.5 Concentrations (in [micro]g/m\3\) for Selected Sites in SJV and Calculation of Annual Average Maximum To
                                                                     Attain in 2015
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                  EPA Estimate for   Lowest recorded
                                                                     Annual          Annual       max. 2015 annual    annual average    Max. 2015% below
                                                                   average  in     average  in    average allowed    1999-2014 (year)   lowest  recorded
                                                                    2013 \a\        2014 \a\       to attain \b\           \b\          annual  average
--------------------------------------------------------------------------------------------------------------------------------------------------------
Hanford........................................................           18.18           17.47               9.47       14.79 (2012)                 36
Visalia........................................................           18.90           17.88               8.34       13.58 (2010)                 39
Bakersfield-California.........................................           19.95           18.55               6.62       13.03 (2012)                 49
Bakersfield-Planz..............................................           22.79           21.61               0.72       14.45 (2011)                 95
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ 2014 AQS Design Value Report, AMP480.
\b\ See Appendix A of the EPA's General TSD.

    In sum, air quality data for the 2013-2014 period indicate that it 
is not practicable for the Hanford, Visalia-Church, Bakersfield-
California, and Bakersfield-Planz monitoring sites to show an annual 
PM<INF>2.5</INF> NAAQS design value at or below 15.0 [micro]g/m\3\ by 
December 31, 2015. While our analyses resulted in slightly different 
numbers for the maximum annual average concentrations allowed to attain 
for 2015, they are consistent with the analysis and conclusion in the 
2015 PM<INF>2.5</INF> Plan that attainment is impracticable at these 
sites. As such, we propose to determine that the SJV area cannot 
practicably attain the 1997 annual PM<INF>2.5</INF> NAAQS by the 
applicable attainment date of December 31, 2015.
Impracticability of Attaining the 1997 24-Hour PM<INF>2.5</INF> 
Standard by December 31, 2015
    According to the District, the maximum 2015 24-hour average 
PM<INF>2.5</INF> concentration at the Bakersfield-Planz site (which 
recorded the area's highest 24-hour average in 2013 and was estimated 
to have recorded the highest 24-hour average concentration in 2014) 
that will enable the site to show a design value at or below 65 
[micro]g/m\3\ for 2015 is 15.9 [micro]g/m\3\.\318\ In addition, the 
District states that other monitoring sites in the southern portion of 
the SJV would have to record improbably low 2015 average 
concentrations, of which the lowest are the Hanford and Bakersfield-
California sites at 44.6 [micro]g/m\3\ and 44.4 [micro]g/m\3\, 
respectively.\319\ Based on these preliminary data and analyses, the 
2015 PM<INF>2.5</INF> Plan concludes that it is not possible for the 
Bakersfield-Planz monitoring site, and extremely unlikely for the 
Hanford and Bakersfield-California sites, to show a 24-hour 
PM<INF>2.5</INF> NAAQS design value at or below 65 [micro]g/m\3\ by 
December 31, 2015.
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    \318\ 2015 PM<INF>2.5</INF> Plan, Chapter 4, Table 4-2, p. 4-5.
    \319\ Id.
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    As with the annual standard, the EPA independently evaluated 2013 
and 2014 PM<INF>2.5</INF> air quality data available in AQS as of June 
30, 2015, and as of January 20, 2016, to assess the District's 
representations.\320\ Table 5 shows the 98th percentile 24-hour average 
PM<INF>2.5</INF> concentrations that were recorded in 2013 and 2014 and 
the maximum concentrations allowed to attain that the EPA estimated for 
2015 at selected monitoring sites. The 98th percentile 24-hour 
concentrations in 2013 and 2014 were higher than in 2012, and in some 
cases the 2013 and 2014 values were significantly higher than the 2012 
value, especially at the Bakersfield-Planz monitoring site, whose 98th 
percentile concentration for 2013 was over 95 [micro]g/m\3\.\321\ Based 
on the 98th percentile values observed in 2013 and 2014, the EPA 
calculated the maximum 98th percentile 24-hour concentration for six 
monitoring sites that would enable the site to show a 2015 24-hour 
PM<INF>2.5</INF> design value at or below 65.4 [micro]g/m\3\.
---------------------------------------------------------------------------

    \320\ See section III and Appendix A of the EPA's General TSD.
    \321\ The 2015 PM<INF>2.5</INF> Plan cites weather conditions 
associated with the extreme drought in California, including low 
precipitation, high stagnation, and strong inversions, among the 
reasons for the high PM<INF>2.5</INF> concentrations observed in the 
winter of 2013-2014. See 2015 PM<INF>2.5</INF> Plan, Chapter 4, pp. 
4-2 to 4-3 and 4-5.
---------------------------------------------------------------------------

    The EPA found that the Bakersfield-Planz monitoring site would have 
to have a 2015 annual mean concentration recorded at 44% below its

[[Page 6964]]

corresponding historical low in order to attain by the end of 
2015.\322\
---------------------------------------------------------------------------

    \322\ See Appendix A of the EPA's General TSD.

       Table 5--2013 and 2014 24-Hour PM2.5 Concentrations (in [micro]g/m\3\) for Selected Sites in SJV and Calculation of Maximum 98th Percentile
                                                                 Concentrations for 2015
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                  EPA estimate for
                                                                      98th            98th        max. 2015  98th    Lowest recorded   Max. 2015%  below
                                                                  Percentile in   Percentile in      percentile      98th percentile    lowest  recorded
                                                                    2013 \a\        2014 \a\     allowed to attain  1999-2014  (year)   annual  average
                                                                                                        \b\                \b\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Hanford........................................................            67.6            81.9               46.7        48.3 (2012)                  3
Bakersfield-California.........................................            71.8            79.9               44.5        53.3 (2010)                 17
Bakersfield-Planz..............................................            96.7            76.7               22.8        40.6 (2012)                 44
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ 2014 AQS Design Value Report, AMP480.
\b\ Appendix A of the EPA's General TSD.

    For these three sites, the EPA's analysis largely confirms the 
analysis presented in the 2015 PM<INF>2.5</INF> Plan of the maximum 
98th percentile concentration allowed for the SJV to attain the 1997 
24-hour PM<INF>2.5</INF> standard by December 31, 2015 (e.g., EPA 
estimated maximum is 22.8 [micro]g/m\3\ at Bakersfield-Planz compared 
to District estimated maximum of 15.9 [micro]g/m\3\, both of which are 
well below the historic low). For the Bakersfield-California site, the 
estimated maximum 98th percentile concentrations are 17% below the 
historic low, which is quite low, while the estimated maximum 98th 
percentile concentration at Hanford site is not drastically different 
than its historic low. However, such values would appear very unlikely 
given the 98th percentile values in 2013 and 2014 and do not alter the 
clear impracticability of attaining the 1997 24-hour PM<INF>2.5</INF> 
standard at the Bakersfield-Planz site.
    In sum, air quality data for the 2013-2014 period indicate that it 
is not practicable for the Bakersfield-Planz monitoring site to show an 
annual PM<INF>2.5</INF> NAAQS design value at or below 15.0 [micro]g/
m\3\ by December 31, 2015. While our analysis resulted in slightly 
different numbers for the maximum annual average concentrations for 
2015, they are consistent with the Plan's analysis and conclusion that 
attainment is impracticable at this site. As such, we propose to 
determine that the SJV area cannot practicably attain the 1997 24-hour 
PM<INF>2.5</INF> NAAQS by the applicable attainment date of December 
31, 2015.
3. Compliance With All Requirements and Commitments in the 
Implementation Plan
    We interpret this criterion to mean that the State has implemented 
the control measures and commitments in the plan revisions it has 
submitted to address the applicable requirements in CAA sections 172 
and 189 for PM<INF>2.5</INF> nonattainment areas. For a Serious area 
attainment date extension request being submitted simultaneously with 
the initial Serious area attainment plan for the area, the EPA proposes 
to read section 188(e) not to require the area to have a fully approved 
Moderate area attainment plan and to allow for extension of the 
attainment date if the area has complied with all Moderate area 
requirements and commitments pertaining to that area in the State's 
submitted Moderate area implementation plan. This interpretation is 
based on the plain language of section 188(e), which requires the State 
to comply with ``all requirements and commitments pertaining to [the] 
area in the implementation plan.'' \323\
---------------------------------------------------------------------------

    \323\ The Ninth Circuit Court of Appeals upheld this 
interpretation of section 188(e) in Vigil v. Leavitt, 366 F.3d 1025, 
amended at 381 F.3d 826 (9th Cir. 2004).
---------------------------------------------------------------------------

    Between 2007 and 2011, California made six SIP submissions to 
address nonattainment area planning requirements for the 1997 
PM<INF>2.5</INF> NAAQS in the SJV,\324\ which we refer to collectively 
as the ``2008 PM<INF>2.5</INF> Plan.'' On November 9, 2011, the EPA 
approved all elements of the 2008 PM<INF>2.5</INF> Plan except for the 
contingency measures, which the EPA disapproved.\325\ As part of this 
action, the EPA approved, among other things, commitments by CARB and 
the SJVUAPCD to take specific actions with respect to identified 
control measures and to achieve specific amounts of NO<INF>X</INF>, 
SO<INF>X</INF>, and direct PM<INF>2.5</INF> emission reductions by 
2014.\326\ In July 2013, the State submitted a revised PM<INF>2.5</INF> 
contingency measure plan for the SJV, which the EPA fully approved in 
May 2014.\327\
---------------------------------------------------------------------------

    \324\ 76 FR 69896 at n. 2 (November 9, 2011).
    \325\ Id. at 69924.
    \326\ Id. at 69926 (codified at 40 CFR 52.220(c)(356)(ii)(B)(2), 
52.220(c)(392)(ii)(A)(2), and 52.220(c)(395)(ii)(A)(2)).
    \327\ 79 FR 29327 (May 22, 2014).
---------------------------------------------------------------------------

    On May 20, 2015, the Ninth Circuit Court of Appeals issued its 
decision in a challenge to the EPA's November 9, 2011 action on the 
2008 PM<INF>2.5</INF> Plan.\328\ In Committee for a Better Arvin et. al 
v. EPA, 786 F.3d 1169 (9th Cir. 2015) (CBA), the court held that the 
EPA violated the CAA by approving the 2008 PM<INF>2.5</INF> Plan even 
though the plan did not include certain state-adopted mobile source 
emission standards on which the plan relied to achieve its emission 
reduction goals.\329\ The CBA court remanded the EPA's action on the 
2008 PM<INF>2.5</INF> Plan for further proceedings consistent with the 
decision but did not vacate the EPA's action.\330\ Thus, absent an EPA 
rulemaking to withdraw or revise the EPA's November 2011 approval of 
the control measure and emission reduction commitments in the 2008 
PM<INF>2.5</INF> Plan, all of these commitments remain enforceable 
components of the California SIP.\331\
---------------------------------------------------------------------------

    \328\ Committee for a Better Arvin et al v. EPA, 786 F.3d 1169 
(9th Cir. 2015).
    \329\ Id.
    \330\ Id.
    \331\ As a consequence of the CBA decision, EPA recently 
proposed to withdraw its May 2014 approval of the District's 
PM<INF>2.5</INF> contingency measure submission and to disapprove 
this submission in its entirety. 80 FR 49190 (August 17, 2015). Upon 
EPA's final withdrawal of this action and disapproval of the 
PM<INF>2.5</INF> contingency measure submission, the measures and 
commitments in this submission will no longer be required components 
of the California SIP.
---------------------------------------------------------------------------

    The specific State and District commitments that the EPA approved 
into the California SIP as part of the 2008 PM<INF>2.5</INF> Plan are 
as follows:
    (1) A commitment by the District to ``adopt and implement the rules 
and measures in the 2008 PM<INF>2.5</INF> Plan'' in accordance with the 
timetable specified in Table 6-2 of the 2008 PM<INF>2.5</INF> Plan, as

[[Page 6965]]

amended June 17, 2010, and to submit these rules and measures to CARB 
for transmittal to the EPA as SIP revisions; \332\
---------------------------------------------------------------------------

    \332\ 40 CFR 52.220(c)(392)(ii)(A)(2), SJVUAPCD Governing Board 
Resolution No. 08-04-10 (April 30, 2008), and SJVUAPCD Governing 
Board Resolution No. 10-06-18 (June 17, 2010); see also 76 FR 69896 
at 69921, Table 1 (November 9, 2011).
---------------------------------------------------------------------------

    (2) A commitment by CARB to propose specific measures identified in 
Appendix B of the ``Progress Report on Implementation of 
PM<INF>2.5</INF> State Implementation Plans (SIP) for the South Coast 
and San Joaquin Valley Air Basins and Proposed SIP Revisions,'' dated 
April 28, 2011 (2011 Progress Report), in accordance with the timetable 
specified therein; \333\
---------------------------------------------------------------------------

    \333\ 40 CFR 52.220(c)(395)(ii)(A)(2), CARB Resolution No. 07-
28, Attachment B (September 27, 2007), CARB Resolution No. 09-34 
(April 24, 2009), and CARB Resolution No. 11-24 (April 28, 2011); 
see also 76 FR 69896 at 69921-69922, Table 2 (November 9, 2011).
---------------------------------------------------------------------------

    (3) A commitment by the District to achieve a total of 8.97 tpd of 
NO<INF>X</INF> emission reductions, 6.7 tpd of direct PM<INF>2.5</INF> 
emission reductions, and 0.92 tpd of SO<INF>X</INF> emission reductions 
by 2014 as described in Table 6-3a, Table 6-3b, and Table 6-3c, 
respectively, of the 2008 PM<INF>2.5</INF> Plan; and
    (4) A commitment by CARB to achieve a total of 17.1 tons per day 
(tpd) of NO<INF>X</INF> emission reductions and 2.3 tpd of direct 
PM<INF>2.5</INF> emission reductions by 2014 as described in CARB 
Resolution No. 07-28, Attachment B, as amended in 2009 and 2011.\334\
---------------------------------------------------------------------------

    \334\ 40 CFR 52.220(c)(356)(ii)(B)(2).
---------------------------------------------------------------------------

    As of November 9, 2011, the date of the EPA's final action on the 
2008 PM<INF>2.5</INF> Plan, CARB and the District had each satisfied 
substantial portions of these control measure and emission reduction 
commitments. Specifically, the District had adopted 12 of the 13 
measures that it had committed to adopt and implement as part of its 
control strategy for attaining the PM<INF>2.5</INF> standards, leaving 
one additional measure that was scheduled for adoption in 2014 (Rule 
4905 (``Natural Gas-Fired, Fan Type Residential Central 
Furnaces'').\335\ CARB had proposed action on six of the seven measures 
that it had committed to propose for Board consideration as part of its 
PM<INF>2.5</INF> control strategy for the SJV, leaving one additional 
measure that was scheduled for proposal in 2013 (``New Emissions 
Standards for Recreational Boats'').\336\ Finally, together CARB and 
the District had achieved all of the SO<INF>X</INF> emission reduction 
commitments and substantial portions of the direct PM<INF>2.5</INF> and 
NO<INF>X</INF> emission reduction commitments through implementation of 
State and District control strategy measures, leaving 3.0 tpd of direct 
PM<INF>2.5</INF> emission reductions and 12.9 tpd of NO<INF>X</INF> 
emission reductions yet to be achieved by the beginning of 2014.\337\
---------------------------------------------------------------------------

    \335\ 76 FR 69896 at 69921, Table 1 (``San Joaquin Valley Air 
Pollution Control District 2008 PM<INF>2.5</INF> Plan Specific Rule 
Commitments'').
    \336\ 76 FR 69896 at 69922, Table 2 (November 9, 2011) (``2007 
State Strategy Defined Measures Schedule for Consideration and 
Current Status'').
    \337\ Id. at 69923, Table 4 (``Reductions Needed for Attainment 
Remaining as Commitments Based on SIP-Creditable Measures'').
---------------------------------------------------------------------------

    The CARB Staff Report for the 2015 PM<INF>2.5</INF> Plan \338\ 
contains the State's demonstration that both CARB and the District have 
satisfied the commitments in the 2008 PM<INF>2.5</INF> Plan that 
remained outstanding as of November 9, 2011, as follows. First, on 
January 22, 2015, the District adopted Rule 4905 and on April 7, 2015, 
CARB submitted this rule to the EPA as a revision to the California 
SIP.\339\ Second, on February 19, 2015, CARB proposed for Board 
consideration, and the Board adopted, new emission standards for 
recreational boats entitled ``Evaporative Emissions Control 
Requirements for Spark-Ignited Watercraft.'' \340\ These State and 
District rulemaking actions satisfied the last remaining commitments 
concerning specific control measures in the 2008 PM<INF>2.5</INF> Plan.
---------------------------------------------------------------------------

    \338\ 2015 PM<INF>2.5</INF> Plan, CARB Staff Report, pp. 17-22 
and Appendix B.
    \339\ CARB Staff Report, Table 7, p. 19 and letter dated April 
7, 2015, from Richard Corey, Executive Officer, CARB, to Jared 
Blumenfeld, Regional Administrator, EPA Region 9 (transmitting air 
district regulations to EPA as California SIP revisions).
    \340\ CARB Staff Report, Table 8, p. 20; see also http://www.arb.ca.gov/regact/2015/simw2015/simw2015.htm.
---------------------------------------------------------------------------

    With respect to the outstanding emission reduction commitments 
(also called ``aggregate commitments''), Tables 9 and 10 of the CARB 
Staff Report, as amended by CARB's Technical Clarifications, identify 
nine specific State and District control measures that, according to 
CARB, achieved emission reductions beyond those already credited toward 
the 2008 PM<INF>2.5</INF> Plan and that satisfy the State's remaining 
2014 emission reduction obligations. These measures are identified in 
Table 6.

   Table 6--2008 PM2.5 Plan Aggregate Commitment--State and District-
                           Identified Measures
------------------------------------------------------------------------
                                             2014 Emission reductions
                                               (annual average tpd)
                 Measure                 -------------------------------
                                                NOX        Direct PM2.5
------------------------------------------------------------------------
Rule 4320 (Advanced Emission Reduction               1.8             0.0
 Options for Boilers, Steam Generators,
 and Process Heaters Greater than 5.0
 MMBtu/hr)..............................
Rule 9510 (Indirect Source Review)......             1.0             0.1
Woodstove Replacements..................             0.0             0.1
District Funded Incentive-Based Emission             1.5             0.1
 Reduction Measures.....................
Rule 9410 (Employer Based Trip                       0.3             0.0
 Reduction).............................
Rule 4901 (Wood Burning Fireplaces and               0.0             1.3
 Wood Burning Heaters)..................
State Funded Incentive-Based Emission                7.8             0.2
 Reduction Measures.....................
CARB Cleaner In-Use Heavy Duty Trucks               11.5             0.1
 Measure................................
CARB Portable Equipment Registration                 2.5             0.2
 Program (PERP) and Portable Engine ATCM
                                         -------------------------------
    Total Emission Reductions...........            26.4             2.1
------------------------------------------------------------------------
Source: CARB Staff Report, pp. 21, 22 and Technical Clarifications, pp.
  2 to 4.

    We have reviewed the State's demonstration with respect to each of 
these nine measures and, for the reasons provided below, we propose to 
find that all but one may be credited toward the State's outstanding 
2014 emission reduction obligations.
    First, with respect to SJVUAPCD's Rule 4320 (``Advanced Emission 
Reduction Options for Boilers, Steam Generators, and Process Heaters 
Greater than 5.0 MMBtu/hr''), also called the ``AERO Rule,'' the EPA 
approved this rule as adopted October 2008 into the

[[Page 6966]]

California SIP on March 25, 2011 \341\ but did not credit the rule with 
any emission reductions as part of the attainment demonstration in the 
2008 PM<INF>2.5</INF> Plan.\342\ In the proposal to approve this rule 
into the SIP, the EPA stated that because this rule allows regulated 
entities to pay a fee in lieu of meeting NO<INF>X</INF> emission 
limits, the State would need to demonstrate that the fee provisions 
achieve emission reductions that are quantifiable, surplus, 
enforceable, and permanent consistent with EPA guidance before relying 
on this rule for credit in an attainment plan.\343\
---------------------------------------------------------------------------

    \341\ 76 FR 16696 (March 25, 2011).
    \342\ 2008 PM<INF>2.5</INF> Plan TSD at pp. 93-94, Table F-4 
(September 30, 2011); see also CARB Staff Report, Appendix B at p. 
B-7 and Table B-8.
    \343\ 75 FR 68294 at 68295 (November 5, 2010).
---------------------------------------------------------------------------

    In the CARB Staff Report, the State explained that it now has 
documentation showing that operators of 472 of the units subject to 
Rule 4320 chose to pay fees and that operators of the remaining 692 
units subject to the rule chose to retrofit their equipment to comply 
with the NO<INF>X</INF> emission limits in the rule.\344\ CARB also 
explained that, based on these enforceable emission limits, the 
District estimated that the operators of the 692 units that did not pay 
fees had achieved 1.8 tpd of actual NO<INF>X</INF> emission reductions 
by the beginning of 2014, based on an operating capacity of 50% or 
75%.\345\ We find this documentation adequate to credit Rule 4320 with 
1.8 tpd of NO<INF>X</INF> emission reductions toward the State's 
outstanding 2014 emission reduction obligation.
---------------------------------------------------------------------------

    \344\ CARB Staff Report, Appendix B at p. B-7.
    \345\ Id. at p. B-8, Table B-8.
---------------------------------------------------------------------------

    Second, with respect to SJVUAPCD's Rule 9510 (``Indirect Source 
Review''), the EPA approved this rule as adopted December 2005 into the 
California SIP on May 9, 2011 \346\ but did not credit the rule with 
any emission reductions as part of the attainment demonstration in the 
2008 PM<INF>2.5</INF> Plan.\347\ In the final rule to approve Rule 9510 
into the SIP, the EPA identified a number of concerns about the 
enforceability of the rule's provisions, e.g., provisions that allow 
project developers to pay a fee instead of implementing on-site 
pollution mitigation plans, and noted that the State would need to 
resolve these enforceability issues before relying on this rule for 
credit in an attainment plan.\348\
---------------------------------------------------------------------------

    \346\ 76 FR 26609 (May 9, 2011).
    \347\ 2008 PM<INF>2.5</INF> Plan TSD at pp. 100-101; see also 
CARB Staff Report, Appendix B at pp. B-6 and B-7.
    \348\ 76 FR 26609 at 26612-26613 (May 9, 2011).
---------------------------------------------------------------------------

    In the CARB Staff Report, the State explained that it now has 
documentation of the number of projects that have complied with the 
rule through on-site mitigation (instead of payment of a fee) and the 
associated reductions in on-site emissions of NO<INF>X</INF> and 
PM<INF>10</INF>.\349\ The project information provided in Appendix B-2 
of the CARB Staff Report, however, is not adequate for the EPA to 
determine what types of mitigation plans were implemented, to verify 
that those plans were implemented as proposed, or to estimate the 
associated emission reductions. Furthermore, it is unclear whether the 
District or any other state or local agency is authorized to enforce 
these mitigation plans. We find this documentation insufficient to 
credit Rule 9510 with any emission reductions toward the State's 
outstanding 2014 emission reduction obligation.
---------------------------------------------------------------------------

    \349\ CARB Staff Report at p. B-6, B-7 (referencing list of 
projects in Appendix B-2).
---------------------------------------------------------------------------

    Third, with respect to wood stove replacements, the CARB Staff 
Report explains that the District implements a voluntary wood stove 
replacement program that provides funding for residents to replace less 
efficient wood stoves with more efficient gas-burning devices.\350\ 
CARB also notes that the District has provided a list of wood stoves 
replaced through this program as of December 31, 2013, together with 
documentation of the calculation methodologies and related emission 
factors that it used to calculate the direct PM<INF>2.5</INF> emission 
reductions achieved by these wood stove replacements.\351\ All wood 
stoves are installed by a District contracted retailer, with pre- and 
post-installation photographs provided to the District. Old wood or 
pellet inserts/stoves are removed and surrendered to a licensed 
recycling/dismantling facility within 60 days of installation.\352\ We 
find this documentation adequate to credit the District's wood stove 
replacement program with 0.1 tpd of direct PM<INF>2.5</INF> emission 
reductions toward the State's outstanding 2014 emission reduction 
obligation.
---------------------------------------------------------------------------

    \350\ Id. at pp. B-5.
    \351\ Id. at pp. B-5, B-6 and Appendix B-1.
    \352\ See SJVAPCD Burn Cleaner Voucher Guidelines, dated 
December 2014, available at: http://valleyair.org/grants/documents/burncleaner/2014/BC_Guidelines.pdf; and SJVAPCD Burn Cleaner Voucher 
Application--Phase 1, dated December 2014, available at: http://valleyair.org/grants/documents/burncleaner/2014/BC_VoucherApp.pdf.
---------------------------------------------------------------------------

    Fourth, with respect to District-funded incentive programs, CARB 
provided a list of stationary and portable agricultural engines and 
off-road agricultural equipment that were repowered, retrofitted with 
controls, or replaced with newer equipment through incentive funds 
disbursed by the District pursuant to the Carl Moyer Memorial Air 
Quality Standards Attainment Program (Carl Moyer Program). 
Specifically, the CARB Staff Report documents the State's bases for 
concluding that a total of 824 incentive projects implemented in the 
SJV between January 2009 and December 2013 in accordance with specified 
portions of the Carl Moyer Program Guidelines have achieved a total of 
1.8 tons per day (tpd) of NO<INF>X</INF> emission reductions and 0.1 
tpd of PM<INF>2.5</INF> emission reductions in the SJV, which may be 
credited toward the State's 2014 emission reduction commitment.\353\ 
The EPA previously reviewed the identified portions of the Carl Moyer 
Program Guidelines and found that they adequately address the EPA's 
recommended integrity elements for economic incentive programs.\354\ We 
find this documentation sufficient to credit these District-funded 
projects with 1.8 tpd of NO<INF>X</INF> emission reductions and 0.1 tpd 
of direct PM<INF>2.5</INF> emission reductions toward the State's 
outstanding 2014 emission reduction obligation.
---------------------------------------------------------------------------

    \353\ CARB Staff Report, pp. B-9 to B-12; Technical 
Clarifications at 2-4; and Revised Appendix B-3.
    \354\ The specified portions of the guidelines that apply to the 
identified projects are contained in The Carl Moyer Program 
Guidelines, Approved Revision 2005; The Carl Moyer Program 
Guidelines, Approved Revision 2008; and The Carl Moyer Program 
Guidelines, Approved Revision 2011. See CARB Staff Report at Table 
B-10. EPA has reviewed these portions of the Carl Moyer Program 
Guidelines and found that they adequately address EPA's recommended 
integrity elements for economic incentive programs. 79 FR 29327 (May 
22, 2014); see also 80 FR 51147 (August 24, 2015).
---------------------------------------------------------------------------

    Fifth, with respect to SJVUAPCD's Rule 9410 (``Employer Based Trip 
Reduction''), CARB submitted this rule as adopted December 2009 to the 
EPA as a revision to the California SIP on May 17, 2010, and on 
December 11, 2015, the EPA fully approved the rule into the SIP.\355\ 
Accordingly, the emission reductions that the State and District have 
attributed to this rule (0.3 tpd of NO<INF>X</INF> emission reductions) 
are creditable toward the State's outstanding 2014 emission reduction 
obligation. As part of the EPA's proposed action on Rule 9410, the EPA 
evaluated the District's estimates of emission reductions achieved by 
the rule and found the District's calculations to be technically sound 
and

[[Page 6967]]

generally consistent with the planning assumptions in the 2008 
PM<INF>2.5</INF> Plan.\356\
---------------------------------------------------------------------------

    \355\ EPA, Final rule, ``Approval and Promulgation of 
Implementation Plans; California; San Joaquin Valley Unified Air 
Pollution Control District; Employer Based Trip Reduction 
Programs,'' pre-publication notice signed December 11, 2015.
    \356\ 80 FR 51153 (August 24, 2015).
---------------------------------------------------------------------------

    Sixth, with respect to SJVUAPCD's Rule 4901 (``Wood Burning 
Fireplaces and Wood Burning Heaters''), the EPA approved this rule as 
adopted October 2008 into the California SIP on November 10, 2009 \357\ 
and credited the rule with 1.08 tpd of direct PM<INF>2.5</INF> emission 
reductions in 2014 as part of the attainment demonstration in the 2008 
PM<INF>2.5</INF> Plan.\358\ In the CARB Staff Report, the State 
explained that it now has documentation of additional direct 
PM<INF>2.5</INF> emission reductions achieved by this rule based on an 
updated methodology for calculating emission reductions from its 
curtailment program. Specifically, the District reviewed ambient air 
quality data for a more recent period (2009-2013) to determine the 
number of ``No Burn'' days that would have been required under the 
mandatory curtailment level (30 [micro]g/m\3\) in the October 2008 
version of Rule 4901. This updated air quality data resulted in a 
larger number of ``No Burn'' days compared to the District's prior 
calculation, which was based on 2006 air quality data.\359\ We find 
this documentation adequate to credit Rule 4901 with 1.3 tpd of direct 
PM<INF>2.5</INF> emission reductions toward the State's outstanding 
2014 emission reduction obligation.
---------------------------------------------------------------------------

    \357\ 74 FR 57907 (November 10, 2009).
    \358\ 2008 PM<INF>2.5</INF> Plan TSD at p. 93, Table F-4 
(September 30, 2011); see also 76 FR 69896 at 69921, Table 1 
(November 9, 2011).
    \359\ 2015 PM<INF>2.5</INF> Plan, Technical Clarifications, p. 
1; and CARB Staff Report, Appendix B, p. B-7.
---------------------------------------------------------------------------

    Seventh, with respect to State Funded Incentive-Based Emission 
Reduction Measures, CARB submitted the ``Report on Reductions Achieved 
from Incentive-based Emission Reduction Measures in the San Joaquin 
Valley'' (Emission Reduction Report) to the EPA as a revision to the 
California SIP on November 17, 2014,\360\ and on August 24, 2015, the 
EPA proposed to fully approve this report into the SIP.\361\ As part of 
this proposal, the EPA evaluated the State's demonstration that 
specified portions of the Carl Moyer Program and Prop 1B Program 
guidelines adequately address the EPA's recommended integrity elements 
for economic incentive programs and that the identified projects funded 
pursuant to these guidelines achieved 7.8 tpd of NO<INF>X</INF> 
emission reductions and 0.2 tpd of direct PM<INF>2.5</INF> emission 
reductions by the beginning of 2014.\362\ Upon final approval of this 
demonstration into the California SIP, these emission reductions would 
be creditable toward the State's 2014 emission reduction obligation. 
Thus, final action by the EPA to fully approve the Emission Reduction 
Report before or concurrent with our final action on the 2015 
PM<INF>2.5</INF> Plan would suffice to credit these state-funded 
projects with 7.8 tpd of NO<INF>X</INF> emission reductions and 0.2 tpd 
of direct PM<INF>2.5</INF> emission reductions toward the State's 
outstanding 2014 emission reduction obligation.
---------------------------------------------------------------------------

    \360\ CARB Staff Report, Appendix B at p. B-2.
    \361\ 80 FR 51147 (August 24, 2015).
    \362\ Id.
---------------------------------------------------------------------------

    Eighth, with respect to CARB's Cleaner In-Use Heavy Duty Trucks 
measure (also called the Truck and Bus Regulation and Drayage Truck 
Regulation), the EPA approved these rules as adopted September 2011 
into the California SIP on April 4, 2012 \363\ and credited the rules 
with 1.1 tpd of NO<INF>X</INF> emission reductions and 1.7 tpd of 
direct PM<INF>2.5</INF> emission reductions in 2014 as part of the 
attainment demonstration in the 2008 PM<INF>2.5</INF> Plan.\364\ In the 
CARB Staff Report, the State explained that it now has documentation of 
additional NO<INF>X</INF> and direct PM<INF>2.5</INF> emission 
reductions achieved by these rules by the beginning of 2014, based on 
current compliance reports indicating that diesel particulate filters 
(DPFs) are more efficient than original estimates and that a larger 
than expected number of truck and bus owners had purchased new vehicles 
(which are cleaner than retrofits) rather than installing retrofit 
DPFs.\365\ We find this documentation adequate to credit CARB's Cleaner 
In-Use Heavy Duty Trucks measure with 11.5 tpd of NO<INF>X</INF> 
emission reductions and 0.1 tpd of direct PM<INF>2.5</INF> emission 
reductions toward the State's outstanding 2014 emission reduction 
obligation.
---------------------------------------------------------------------------

    \363\ 77 FR 20308 (April 4, 2012).
    \364\ 2008 PM<INF>2.5</INF> Plan TSD, Table F-8, p. 99 
(September 30, 2011).
    \365\ CARB Staff Report, Appendix B, pp. B-2 to B-4.
---------------------------------------------------------------------------

    Finally, with respect to CARB's Portable Equipment Registration 
Program (PERP) and Portable Engine Airborne Toxic Control Measure 
(Portable Engine ATCM), CARB adopted these programs in 1997 and 2004, 
respectively, to reduce pollution by requiring the removal of 
uncertified engines from the registered fleet of nonroad engines 
operating in California.\366\ The EPA did not credit either of these 
programs with emission reductions as part of the attainment 
demonstration in the 2008 PM<INF>2.5</INF> Plan.\367\ On December 6, 
2012, the EPA granted California's request for authorization under CAA 
section 209(e)(2) to implement both the PERP and the Portable Engine 
ATCM.\368\ On August 14, 2015, CARB submitted these measures to the EPA 
for SIP approval and on November 12, 2015, the EPA proposed to approve 
both measures as revisions to the California SIP.\369\ Upon final 
approval of these measures into the SIP, their requirements will be 
federally enforceable and the associated emission reductions will be 
creditable for attainment planning purposes in the SJV. Thus, final 
action by the EPA to fully approve the PERP and the Portable Engine 
ATCM before or concurrent with our final action on the 2015 
PM<INF>2.5</INF> Plan would suffice to credit these measures with 2.5 
tpd of NO<INF>X</INF> emission reductions and 0.2 tpd of 
PM<INF>2.5</INF> reductions toward the State's outstanding 2014 
emission reduction obligation.
---------------------------------------------------------------------------

    \366\ Id. at pp. B-4, B-5 and Technical Clarifications, p. 3.
    \367\ 2008 PM<INF>2.5</INF> Plan TSD, Table F-8, p. 99 
(September 30, 2011).
    \368\ 77 FR 72846 and 77 FR 72851 (December 6, 2012).
    \369\ Letter dated August 14, 2015, from Richard W. Corey, 
Executive Officer, California Air Resources Board, to Jared 
Blumenfeld, Regional Administrator, EPA Region 9, with attachments. 
80 FR 69915 (November 12, 2015).
---------------------------------------------------------------------------

    According to the CARB Staff Report, implementation of these control 
measures resulted in NO<INF>X</INF> emission reductions that exceeded 
the State's outstanding NO<INF>X</INF> commitment by 13.9 tpd by the 
beginning of 2014.\370\ Citing air quality modeling conducted as part 
of the 2008 PM<INF>2.5</INF> Plan, CARB stated that a reduction of 9 
tpd of NO<INF>X</INF> emissions provides an air quality improvement 
equivalent to a 1 tpd reduction in directly emitted PM<INF>2.5</INF>. 
On this basis, CARB concluded that an 8.1 tpd portion of the 13.9 tpd 
of surplus NO<INF>X</INF> reductions achieved through implementation of 
the identified State and District measures adequately covered the small 
shortfall (0.9 tpd) in required reductions of direct 
PM<INF>2.5</INF>.\371\
---------------------------------------------------------------------------

    \370\ CARB Staff Report at pp. 21, 22.
    \371\ Id.
---------------------------------------------------------------------------

    Table 7 identifies the State and District measures that the EPA is 
proposing to credit toward the State's outstanding 2014 emission 
reduction obligations, the amount of SIP-creditable emission reductions 
for each measure, and the 9:1 NO<INF>X</INF> for PM<INF>2.5</INF> 
trading ratio \372\ calculation that the EPA is proposing to accept for 
this purpose. The total amount of SIP-creditable NO<INF>X</INF> 
emission reductions associated with the identified control measures 
(25.4 tpd) exceeds the State's outstanding NO<INF>X</INF> emission 
reduction commitment (12.9

[[Page 6968]]

tpd) by 12.5 tpd.\373\ We believe the technical bases for a 9:1 
NO<INF>X</INF> for PM<INF>2.5</INF> trading ratio are generally sound 
and have therefore used this trading ratio to credit the State with 1 
additional tpd of PM<INF>2.5</INF> emission reduction (based on 9 tpd 
of ``excess'' NO<INF>X</INF> emission reductions) toward its 
outstanding 2014 commitment. In evaluating the interpollutant trading 
used for the aggregate commitments (as well as for Reasonable Further 
Progress and for Motor Vehicle Emissions Budgets for conformity), the 
EPA considered the regulatory basis for allowing interpollutant 
trading, 24-hour and annual averaging times, the pollutant trading 
direction, the geographical extent of emissions, the conservativeness 
and the numerical stability of the ratio, and the geographical 
variation of the trading ratio. For further discussion of our 
evaluation of the 9:1 NO<INF>X</INF> to PM<INF>2.5</INF> trading ratio 
for purposes of the aggregate commitment, please see section IV.C of 
the EPA's ``Technical Support Document for EPA's Evaluation of 
Interpollutant Trading Ratios For Fine Particulate Matter Emissions in 
the San Joaquin Valley Air Pollution Control District,'' January 2016 
(``Interpollutant Trading Ratios TSD'').
---------------------------------------------------------------------------

    \372\ We use ``trading ratio'' in this action to refer to the 
extent to which reductions of one pollutant are substituted for 
necessary reductions of another pollutant.
    \373\ As explained in this section, we find CARB's documentation 
insufficient to credit Rule 9510 with any emission reductions toward 
the State's outstanding 2014 emission reduction obligation and, 
therefore, do not entirely agree with CARB's conclusion that it 
achieved 13.9 tpd of NO<INF>X</INF> emission reductions in excess of 
its outstanding commitments. The difference between the 25.4 tpd of 
NO<INF>X</INF> emission reductions achieved by the control measures 
identified in Table 7 and the State's outstanding 12.9 tpd 
NO<INF>X</INF> emission reduction commitment is 12.5 tpd of 
``excess'' NO<INF>X</INF> emission reductions.

  Table 7--2008 PM2.5 Plan Aggregate Commitment--EPA Proposed Emission
     Reduction Credits for Measures in CARB Compliance Demonstration
------------------------------------------------------------------------
                                             2014 emission reductions
                                               (annual average tpd)
                 Measure                 -------------------------------
                                                NOX        Direct PM2.5
------------------------------------------------------------------------
Rule 4320 (Advanced Emission Reduction               1.8             0.0
 Options for Boilers, Steam Generators,
 and Process Heaters Greater than 5.0
 MMBtu/hr)..............................
Rule 9510 (Indirect Source Review)......             0.0             0.0
Woodstove Replacements..................             0.0             0.1
District Funded Incentive-Based Emission             1.5             0.1
 Reduction Measures.....................
Rule 9410 (Employer Based Trip                       0.3             0.0
 Reduction).............................
Rule 4901 (Wood Burning Fireplaces and               0.0             1.3
 Wood Burning Heaters)..................
State Funded Incentive-Based Emission                7.8             0.2
 Reduction Measures.....................
CARB Cleaner In-Use Heavy Duty Trucks               11.5             0.1
 Measure................................
CARB Portable Equipment Registration                 2.5             0.2
 Program (PERP) and Portable Engine ATCM
                                         -------------------------------
    Total SIP-Creditable Emission                   25.4             2.0
     Reductions from State and District
     Measures...........................
NOX to PM2.5 Emissions Equivalence (9:1)            -9.0             1.0
                                         -------------------------------
    Total Emission Reductions Achieved..            16.4             3.0
------------------------------------------------------------------------

    In sum, the CARB Staff Report demonstrates that implementation of 
State and District measures achieved a total of 16.4 tpd of 
NO<INF>X</INF> emission reductions and 3.0 tpd of direct 
PM<INF>2.5</INF> emission reductions that have not previously been 
credited as part of the attainment demonstration in the 2008 
PM<INF>2.5</INF> Plan and that may, therefore, be credited toward the 
State's outstanding obligation to achieve 12.9 tpd of NO<INF>X</INF> 
emission reductions and 3.0 tpd of direct PM<INF>2.5</INF> emission 
reductions by the beginning of 2014.
    Based on these evaluations, we propose to determine that California 
has complied with all requirements and commitments pertaining to the 
SJV area in the implementation plan.
4. Demonstration That the Implementation Plan Includes the Most 
Stringent Measures
    We interpret this criterion to mean that the State must demonstrate 
to the EPA's satisfaction that its serious area plan includes the most 
stringent measures that are included in the implementation plan of any 
state, or achieved in practice in any state, and can feasibly be 
implemented in the area.
    As discussed above in section V.D, because of the substantial 
overlap in the source categories and controls evaluated for BACM and 
those evaluated for MSM, we present our evaluation of the 2015 
PM<INF>2.5</INF> Plan's provisions for including MSM alongside our 
evaluation of the Plan's provisions for implementing BACM for each 
identified source category. For the reasons provided in section V.D and 
further in the EPA's SJV Rules TSD, we propose to determine that the 
2015 PM<INF>2.5</INF> Plan provides for the implementation of MSM for 
sources of direct PM<INF>2.5</INF> and PM<INF>2.5</INF> precursors as 
expeditiously as practicable, in accordance with the requirement in CAA 
section 188(e).
5. Demonstration of Attainment by the Most Expeditious Alternative Date 
Practicable
    Section 189(b)(1)(A) of the CAA requires that each Serious area 
plan include a demonstration (including air quality modeling) that the 
plan provides for attainment of the PM<INF>2.5</INF> NAAQS by the 
applicable attainment date or, where the State is seeking an extension 
of the attainment date under section 188(e), a demonstration that 
attainment by that date is impracticable and that the plan provides for 
attainment by the most expeditious alternative date practicable. We 
discuss below our evaluation of the modeling approach in the Plan, the 
State's basis for excluding one 24-hour data point from the modeling 
analysis, and the control strategy in the Plan for attaining the 1997 
annual and 24-hour PM<INF>2.5</INF> NAAQS by the most expeditious 
alternative dates practicable.
Evaluation of Air Quality Modeling Approach and Results
    The EPA's PM<INF>2.5</INF> modeling guidance \374\ (``Modeling 
Guidance'' and

[[Page 6969]]

``Modeling Guidance Update'') recommends that a photochemical model, 
such as CAMx or CMAQ, be used to simulate a base case, with 
meteorological and emissions inputs reflecting a base case year, to 
replicate concentrations monitored in that year. The model application 
to the base case year undergoes a performance evaluation to ensure that 
it satisfactorily agrees with concentrations monitored in that year. 
The model may then be used to simulate emissions occurring in other 
years required for a plan, namely the base year (which may differ from 
the base case year) and future year.\375\ The modeled response to the 
emission changes between those years is used to calculate Relative 
Response Factors (RRFs), which are applied to the design value in the 
base year to estimate the projected design value in the future year for 
comparison against the NAAQS. Separate RRFs are estimated for each 
chemical species component of PM<INF>2.5</INF>, and for each quarter of 
the year, to reflect their differing responses to seasonal 
meteorological conditions and emissions. Since each species is handled 
separately, before applying an RRF the base year design value must be 
speciated using available chemical species measurements, that is, each 
day's measured PM<INF>2.5</INF> comprising the design value must be 
split into its species components. The Modeling Guidance provides 
additional detail on the recommended approach.\376\
---------------------------------------------------------------------------

    \374\ ``Guidance on the Use of Models and Other Analyses for 
Demonstrating Attainment of Air Quality Goals for Ozone, 
PM<INF>2.5</INF>, and Regional Haze,'' EPA-454/B-07-002, April 2007 
(``Modeling Guidance''); and ``Update to the 24 Hour 
PM<INF>2.5</INF> NAAQS Modeled Attainment Test,'' Memorandum from 
Tyler Fox, Air Quality Modeling Group, OAQPS, EPA to Regional Air 
Program Managers, EPA, June 28, 2011 (``Modeling Guidance Update'').
    \375\ In this section, we use the terms ``base case,'' ``base 
year'' or ``baseline,'' and ``future year'' as described in section 
3.5 of the EPA's Modeling Guidance. The ``base case'' modeling 
simulates measured concentrations for a given time period, using 
emissions and meteorology for that same year. The modeling ``base 
year'' (which can be the same as the base case year) is the 
emissions starting point for the plan and for projections to the 
future year, both of which are modeled for the attainment 
demonstration. See Modeling Guidance at pp. 33-34. Note that CARB 
sometimes uses ``base year'' synonymously with ``base case'' and 
``reference year'' instead of ``base year.''
    \376\ Modeling Guidance Update at 43 ff.
---------------------------------------------------------------------------

    The attainment demonstration in the 2015 PM<INF>2.5</INF> Plan is 
based on modeling performed for the 2008 PM<INF>2.5</INF> Plan, but 
that modeling is used in a streamlined way, by employing scaling. The 
attainment demonstration approach in the 2015 PM<INF>2.5</INF> Plan is 
covered in its Chapter 4 (``Classification and Attainment'') and 
Appendix F (``Attainment Demonstration''), with several further details 
in Appendix A (``Weight of Evidence Analysis'') of the CARB Staff 
Report. For the modeling used in this Plan, the base case year was 
2000, the base year was 2012, and the future years were 2018 and 2020 
for the 24-hour and annual PM<INF>2.5</INF> standards, respectively. 
CARB scaled the results from modeling performed for the 2008 
PM<INF>2.5</INF> Plan, assuming the same relative response to emission 
changes applies in the time frame for the current Plan. Starting from 
the RRFs from the 2008 PM<INF>2.5</INF> Plan, which reflect the 
emission changes from the base year to the future year in that plan 
(2005 to 2014), CARB scaled those RRFs to reflect the current 2015 
PM<INF>2.5</INF> Plan's base year to future year emission changes (2012 
to 2020 for the annual standard, and 2012 to 2018 for the 24-hour 
standard).
    The formula in the 2015 PM<INF>2.5</INF> Plan \377\ for scaling an 
RRF is based on the definition of an RRF as (modeled future 
concentration)/(modeled base year concentration), and on the assumption 
that the modeled percent change in concentration per percent change in 
emissions is the same for the 2015 PM<INF>2.5</INF> Plan as it was for 
the 2008 PM<INF>2.5</INF> Plan. As shown in section IV.A of the EPA's 
General TSD for this action, these assumptions lead to the Plan 
formula. Since the RRF includes the modeled effect of emission changes, 
accounting for their temporal and spatial distribution and their 
chemistry, the scaling approach used in the 2015 PM<INF>2.5</INF> Plan 
differs from a simple ``rollback'' scaling (which would merely assume 
that the percent concentration change is identical to the percent 
emissions change).
---------------------------------------------------------------------------

    \377\ 2015 PM<INF>2.5</INF> Plan, Chapter 4, p. 4-8, and 
Appendix F, p. F-4.
---------------------------------------------------------------------------

    CARB's procedure for using emissions from the two plans in the RRF 
scaling formula differed to some extent between the two plans due to 
data availability, even though ideally they would be treated in the 
same way. The reason the scaling is being done rather than new modeling 
is that modeling inventories were not available for the base and future 
years of the 2015 PM<INF>2.5</INF> Plan. Only the planning inventories 
are available; they cover all the source categories, but do not reflect 
the allocation of the emissions to all the grid squares in the modeling 
domain and to all the hours of the year, a considerable undertaking 
necessary for input to the model. Absent the future modeling 
inventories, the most consistent way to perform the scaling would be to 
use planning inventories from both the new and old plans. Because the 
scaling is done for each chemical species, the inventories used should 
also be speciated using the same procedure, by applying speciation 
profiles for the various emission source categories. Unfortunately, the 
old speciation profiles for the 2008 PM<INF>2.5</INF> Plan were not 
available, so the planning inventory from the 2008 PM<INF>2.5</INF> 
Plan could not be speciated in the same way as the 2015 
PM<INF>2.5</INF> Plan planning inventory could. Therefore, CARB used 
the modeling inventory from the 2008 PM<INF>2.5</INF> Plan, which did 
have a speciation procedure comparable to that available for the 2015 
PM<INF>2.5</INF> Plan planning inventory. In sum, in calculating the 
RRF scaling factors, CARB used the modeling inventory to compute 
percent emission changes for the 2008 PM<INF>2.5</INF> Plan and used 
the planning inventory for emission changes for the 2015 
PM<INF>2.5</INF> Plan.<SUP>378 379</SUP>
---------------------------------------------------------------------------

    \378\ 2015 PM<INF>2.5</INF> Plan, Appendix F, p. F-4.
    \379\ Modeling the ambient PM<INF>2.5</INF> components of 
elemental carbon (EC) and organic carbon (OC) and geological 
material requires emissions for those, derived from speciation 
profiles of the various emission source categories. The RRF scaling 
also requires separate EC and OC emissions. But planning 
inventories, such as that available for the 2008 plan, generally 
report only direct PM<INF>2.5</INF> emissions, the total of these 
species.
---------------------------------------------------------------------------

    CARB's modeling domain is somewhat larger than the SJV 
nonattainment area, so emission totals differ between the modeling 
inventory and the planning inventory. But we expect that percent 
changes are comparable because both the modeling inventories and 
planning inventories reflect emissions from the same types of sources 
and in similar proportions. The inventories also reflect similar 
controls, for example statewide motor vehicle emissions controls, where 
motor vehicles are the main source of NO<INF>X</INF>. We also expect 
the ratios of the percent changes, i.e., the RRF scaling factors 
themselves, to be comparable given discrepancies between the modeling 
and planning inventories would typically be similar for the two plans 
used in the ratio, and hence canceled out to an extent.
    The 2015 PM<INF>2.5</INF> Plan provided several bases to support 
the use of a scaling approach premised on the 2008 PM<INF>2.5</INF> 
Plan model response. The base case in the previous modeling was based 
on extensive measurements during the 2000 CRPAQS study,\380\ and the 
underlying meteorological conditions leading to high PM<INF>2.5</INF> 
concentrations in the 2000-2001 winter were similar to those in the 
2013-2014 winter, including persistent pressure ridges, surface 
inversions, cool temperatures,

[[Page 6970]]

and low winds.\381\ Also, the 2004-2006 PM<INF>2.5</INF> species 
composition data that CARB used for speciating PM<INF>2.5</INF> 
concentrations in the 2008 PM<INF>2.5</INF> Plan show a similar 
composition to 2011-2013 speciation measurements that CARB used in the 
2015 PM<INF>2.5</INF> Plan to speciate design values prior to applying 
RRFs, as seen in composition pie charts for Bakersfield, Fresno, 
Modesto, and Visalia.\382\
---------------------------------------------------------------------------

    \380\ 2000 California Regional Particulate Air Quality Study 
(CRPAQS); descriptive documents available on CARB's ``Central 
California Air Quality Studies'' Web site at http://www.arb.ca.gov/airways.
    \381\ 2015 PM<INF>2.5</INF> Plan, Appendix F, p. F-4, and WOEA, 
p. A-5.
    \382\ 2015 PM<INF>2.5</INF> Plan, Appendix F, Attachment A, p. 
F-8 to F-10.
---------------------------------------------------------------------------

    These observations indicate that the 2013 PM<INF>2.5</INF> design 
values for the current 2015 PM<INF>2.5</INF> Plan would respond in a 
way similar to the 2008 PM<INF>2.5</INF> Plan modeling. An alternative 
would have been to use modeling from the 2012 PM<INF>2.5</INF> Plan, 
which had a 2007 meteorology and emissions base case, which is more 
recent than that in the 2008 PM<INF>2.5</INF> Plan. However, it modeled 
only the first and fourth quarters, the only quarters needed to address 
the 24-hour NAAQS; the 2008 PM<INF>2.5</INF> Plan modeled the entire 
year, and so was suitable for assessing both the 24-hour and the annual 
PM<INF>2.5</INF> NAAQS.
    CARB calculated an RRF from the scaling formula using the 
concentration of each PM<INF>2.5</INF> chemical species, with emissions 
from the corresponding precursor. CARB used percent changes in 
emissions of NO<INF>X</INF>, SO<INF>X</INF>, Organic Carbon (OC), 
Elemental Carbon (EC), and other (direct PM<INF>2.5</INF> less OC and 
EC), to scale the RRF for the corresponding ambient PM<INF>2.5</INF> 
component: Nitrate (NO<INF>3</INF><SUP>-</SUP>), sulfate 
(SO<INF>4</INF><SUP>-2</SUP>), OC, EC, and geological material (also 
called ``other'' or ``dust''). For the ammonium component, which is 
present in ammonium nitrate and ammonium sulfate, a choice must be made 
as to which precursor emissions, either NO<INF>X</INF> or 
SO<INF>2</INF>, should be used in scaling ammonia; CARB used 
NO<INF>X</INF>.
    This is in line with information in the Plan indicating that 
ammonium nitrate formation responds far more to NO<INF>X</INF> emission 
changes than to ammonia changes. The Plan also noted that sulfate is a 
much smaller ambient component than nitrate, so that ammonium scales 
more with NO<INF>X</INF> than with SO<INF>2</INF>.\383\ Conceivably 
some combination of precursor emissions could have been used for 
scaling ammonium, but that would require a plausibility argument about 
how to reflect the actual chemistry involved, a complication that would 
obscure both the relative simplicity of direct scaling and the more 
comprehensive consideration of chemistry already present in the 
modeling being scaled. Another point about the choice of NO<INF>X</INF> 
is that ammonium concentrations were independent of ammonia emissions, 
since the latter was not used, and so inherently cannot respond to 
increases or decreases of ammonia that occur during the planning 
period.
---------------------------------------------------------------------------

    \383\ 2015 PM<INF>2.5</INF> Plan, Appendix F, p. F-5.
---------------------------------------------------------------------------

    As discussed in section V.C of this notice, modeling for the 2012 
PM<INF>2.5</INF> Plan showed that there is a small ambient response to 
ammonia changes. Additionally, annual average ammonia emissions in the 
planning inventory increase by 8.6% from 2012 to 2020, which suggests 
that the ammonium contribution to projected design values may be higher 
than stated in the Plan. However, this is of little concern since the 
pre-scaled RRFs for ammonium, nitrate, and sulfate were based on actual 
modeling for the 2008 PM<INF>2.5</INF> Plan; they take into account the 
atmospheric chemistry and the ambient effects due to ammonia changes 
during 2005-2014, when the annual average ammonia emissions increased 
by 18.1%.
    Aside from the RRFs themselves, the procedure that CARB followed in 
the 2015 PM<INF>2.5</INF> Plan for projecting design values is 
consistent with the recommendations in the Modeling Guidance. The steps 
included using daily speciation data and the SANDWICH approach \384\ to 
split daily measured PM<INF>2.5</INF> concentrations into their 
chemical components, taking quarterly averages (of all days for the 
annual standard, and of the highest 10% or so of days for the 24-hour 
standard), applying RRFs to get future component concentrations, 
summing to total PM<INF>2.5</INF>, and finally averaging over quarters 
and years to estimate the future design value.
---------------------------------------------------------------------------

    \384\ Sulfate, Adjusted Nitrate, Derived Water, Inferred 
Carbonaceous mass material balance approach: Modeling Guidance, p. 
47; Frank, N., 2006: ``Retained Nitrate, Hydrated Sulfates, and 
Carbonaceous Mass in Federal Reference Method Fine Particulate 
Matter for Six Eastern U.S. Cities,'' J. Air Waste Management 
Assoc., 56, 500-511.
---------------------------------------------------------------------------

    Two aspects of the Plan's approach to modeling differ from the 
Modeling Guidance recommendations. First, for the 24-hour 
PM<INF>2.5</INF> NAAQS, the RRFs were applied to a single high value 
per quarter to represent the potential 98th percentile, as opposed to 
applying RRFs to multiple high individual days in each quarter, and 
then choosing the 98th percentile. The former approach is consistent 
with the original Modeling Guidance, before it was updated to the 
latter approach by the June 28, 2011 Modeling Guidance Update.\385\ The 
latter approach is intended to allow for the shifting of high days 
between quarters as emission controls are applied: a day that has a 
concentration in the top 10% in the autumn may more strongly respond to 
controls and no longer be in the top 10%, while a summer day may 
respond less to controls and end up being in the post-control top 10%. 
Because winter PM<INF>2.5</INF> concentrations are significantly higher 
than those in the other seasons, such shifting is very unlikely to be 
an issue in the SJV.
---------------------------------------------------------------------------

    \385\ Modeling Guidance, p. 58 and Modeling Guidance Update, p. 
B-2 (Steps 1, 4, and 5).
---------------------------------------------------------------------------

    Second, the Modeling Guidance recommends that RRFs be applied to 
the average of three three-year design values \386\ (e.g. using data in 
2010-2012, 2011-2013, and 2012-2014), whereas the Plan used just the 
single 2013 design value (2011-2013 data). The 2011-2013 period for the 
2013 design value is centered on the Plan's 2012 base year, as the 
Modeling Guidance recommends. One reason for the longer period in EPA's 
recommendation is that the additional averaging provides some stability 
in the estimate.
---------------------------------------------------------------------------

    \386\ Modeling Guidance, p. 22; and Modeling Guidance Update, p. 
B-1.
---------------------------------------------------------------------------

    Although the Plan's procedure is not entirely consistent with EPA 
guidance, we find it acceptable in this context given the time 
constraints imposed by EPA's April 2015 reclassification of the SJV 
area \387\ and the available modeling analyses. Despite the presence of 
scaling at a key step, CARB's approach remains a modeled attainment 
demonstration as required by section 189(b)(1)(A) of the Act. It relies 
on photochemical modeling that EPA reviewed and approved \388\ for the 
2008 PM<INF>2.5</INF> Plan, and which remains sufficiently 
representative of PM<INF>2.5</INF> formation in the SJV.
---------------------------------------------------------------------------

    \387\ 80 FR 18528 at 18530 (April 7, 2015) (noting unusually 
short timeframe for State's development and submission of a plan to 
provide for attainment of the 1997 PM<INF>2.5</INF> NAAQS by the 
Serious area attainment date, which is December 31, 2015).
    \388\ ``Technical Support Document for the Proposed Action on 
the San Joaquin Valley 2008 PM<INF>2.5</INF> Plan and the San 
Joaquin Valley Portions of the Revised 2007 State Strategy,'' EPA 
Region 9, November 8, 2010, for proposed approval in 75 FR 74518 
(November 30, 2010); final approval was in 76 FR 69896 (November 9, 
2011).
---------------------------------------------------------------------------

    Three other considerations give some reassurance of the 
acceptability of a scaling approach. First, EPA's 2014 draft modeling 
guidance explicitly recognizes that ``there may be plausible 
alternative means of calculating the relative response factors [RRFs] 
that can differ from the approaches recommended.'' \389\ While this 
2014 draft guidance does not

[[Page 6971]]

specifically address the alternative of scaled RRFs, it indicates, as 
does the Modeling Guidance, that alternatives to the recommended 
procedures are acceptable where adequately supported. Second, even the 
recommended RRF procedure involves model sensitivity derived from one 
period being applied to another: RRFs are computed using a single 
year's modeled response to emissions changes, but are assumed to be 
applicable to all five years composing the average over three design 
values. This consideration makes the 2015 PM<INF>2.5</INF> Plan's 
application of the model response from one period to another analogous 
to the application more broadly envisioned by the Modeling Guidance.
---------------------------------------------------------------------------

    \389\ ``Modeling Guidance for Demonstrating Attainment of Air 
Quality Goals for Ozone, PM<INF>2.5</INF>, and Regional Haze'', 
DRAFT December 2014, EPA OAQPS, p. 99.
---------------------------------------------------------------------------

    Finally, while scaling itself is relatively crude, the scaling of 
RRFs is less so. The procedure is not a simple scaling of an emission 
total, but reflects the geographic and temporal distribution of the 
emissions sources and the emission changes, since it is based on 
modeling. The pattern of emission changes during the span of the 2015 
PM<INF>2.5</INF> Plan does not exactly match the changes modeled for 
the span of the 2008 PM<INF>2.5</INF> Plan, but many of the emission 
reductions continue the effect of existing controls on the same types 
of sources, so the patterns of the emissions changes are unlikely to be 
very different. For example, continued vehicle NO<INF>X</INF> emission 
reductions occur over much the same roadway network and direct 
PM<INF>2.5</INF> reductions from controls on wood burning are largely 
achieved from the same residential areas.
    Late in EPA's review process, EPA and CARB found that the scaling 
factor for EC had been applied to the RRF for OC and the product used 
as the RRF for EC, and vice versa.\390\ Because the original RRFs for 
OC were larger than those for EC, and remained so after scaling, 
applying the smaller EC scaled RRFs to OC made the projected OC 
concentration smaller than it should have been. Conversely, projected 
EC was larger than it should have been. Because OC has a larger ambient 
contribution than EC, the OC effect dominates. The net result of the 
EC-OC reversal is that the projected design values for the attainment 
demonstration were underestimated. CARB estimates that the 2020 annual 
design value for Madera increased from the 2015 PM<INF>2.5</INF> Plan's 
original 15.0 [micro]g/m\3\ to a corrected value of 16.2 [micro]g/
m\3\,\391\ which is above the 1997 annual PM<INF>2.5</INF> NAAQS.
---------------------------------------------------------------------------

    \390\ Letter from K. Magliano, CARB to K. Drake, EPA Region 9, 
August 12, 2015. See also, Memo to file, ``Call with California Air 
Resources Board regarding letter about reversal of elemental and 
organic carbon,'' S. Bohning, EPA Region 9, September 18, 2015.
    \391\ Id., Attachment A (``Revised San Joaquin Valley 
PM<INF>2.5</INF> Design Values'').
---------------------------------------------------------------------------

    However, CARB presents compelling reasons for discounting this high 
Madera projected 2020 annual design value. The starting point for the 
scaled modeling projection is the 2013 design value--the average of 
annual means during 2011-2013. The 2011 monitoring data included within 
that 2013 design value appears anomalous, as documented in the WOEA at 
Appendix A2 (``Assessment of the Representativeness of 2011 
PM<INF>2.5</INF> Beta Attenuation Monitor Data from Madera'') and 
Attachment B to CARB's Technical Clarifications of August 12, 2015 
(``Attachment B''). We refer herein to figures and tables in Appendix 
A2 of the WOEA as ``S.R. App. A2, Figure 2.''
    EPA's regulations require that monitoring data for comparison to 
the NAAQS be collected using specific equipment and procedures to 
ensure accuracy and reliability.\392\ For each NAAQS, the default 
monitoring equipment and the procedures for operating it are termed the 
Federal Reference Method (FRM); an alternative approach, termed a 
Federal Equivalent Method (FEM) may also be used if it is demonstrated 
to give results comparable to an FRM monitor. The Met One Beta 
Attenuation Monitor (BAM) 1020 is an example of an FEM that provides 
continuous hourly PM<INF>2.5</INF> concentrations compared to the FRM's 
24-hour average PM<INF>2.5</INF> concentrations. This is useful for a 
number of purposes, including real-time forecasting for deciding when 
to issue public advisories and wood burning restrictions, as well as 
for evaluating air quality model performance. BAMs are deployed at 
multiple sites in the SJV, including Madera (the ``Madera-City'' site, 
AQS ID 06-039-2010).\393\
---------------------------------------------------------------------------

    \392\ 40 CFR parts 53 and 58.
    \393\ 2015 PM<INF>2.5</INF> Plan, Chapter 4, Table 4-3 
(``Projected 2020 Annual and 2018 24-hour Design Values''), p.4-9.
---------------------------------------------------------------------------

    As described in the S.R. App. A2, 2011 was the first full year of 
data collected by the Madera BAM, and the concentrations were 
unexpectedly high in comparison with other monitoring sites, including 
both BAMs and FRM monitor sites. During 2011-2013, annual 
concentrations at Madera were some 30% higher than at Fresno, and as 
much as 100% higher during the summer, historically the season with the 
lowest PM<INF>2.5</INF>.\394\ This was unexpected because historically 
there has been a north-to-south increasing gradient of concentrations, 
with northern sites like Stockton and Merced at the low end, and 
southern sites like those in Bakersfield at the high end, and with 
central sites like Fresno somewhere in between.\395\ This gradient is 
consistent with the greater potential for ventilation at the northern 
end of the SJV, nearest the opening to the ocean at the Golden Gate, 
and the lower ventilation at the southern end, surrounded by mountains. 
Madera and Fresno concentrations are highly correlated,\396\ suggesting 
common meteorological influences at the two sites, as opposed to 
additional emission sources contributing at Madera.
---------------------------------------------------------------------------

    \394\ S.R. App. A2, Figures 3 and 4, and Tables 1 and 2.
    \395\ S.R. App. A2, Figure 2.
    \396\ S.R. App. A2, Figure 3.
---------------------------------------------------------------------------

    Various checks on the monitor and its operation were made over time 
without affecting the high readings, but in April 2014, adjustments 
were made as a result of checking the zero point of the instrument 
using outdoor air, rather than indoor air (both are permissible; 
outdoor air could be more representative of the conditions the 
instrument normally operates under).\397\ After that time, Madera 
concentrations shifted to lower values,\398\ conformed better to the 
known north-south gradient,\399\ and tracked closely with the monitored 
data from the Merced-Coffee Road site about 30 miles to the North, 
which is expected given the two monitors' proximity to one another and 
similar geographic conditions.\400\ They also agreed better with 
measurements at a new FRM installed in July 2014 at the Madera 
site.\401\ ARB concluded that the 2011 ``BAM data at Madera appear to 
be biased high due to sampling artifacts . . . not representative of 
air quality in the central portion of the Valley''.\402\
---------------------------------------------------------------------------

    \397\ ``BAM 1020 Particulate Monitor Operation Manual, BAM-1020-
9800 Rev K'', Met One Instruments, Inc. 2008; Memorandum from Tim 
Hanley, Office of Air Quality Planning and Standards, EPA to Met One 
BAM Users, ``RE: Zero Tests on the Met One BAM 1020,'' October 5, 
2012.
    \398\ S.R. App. A2, Figure 8.
    \399\ S.R. App. A2, Figure 9.
    \400\ Letter from K. Magliano, CARB to A. Steckel, EPA Region 9, 
August 12, 2015, Attachment B, p. 2.
    \401\ S.R. App. A2, Figures 12 and 13.
    \402\ S.R. App. A2, p.A2-9.
---------------------------------------------------------------------------

    The 2015 PM<INF>2.5</INF> Plan nevertheless included the 2011 
Madera data and 2013 design value in the attainment demonstration, 
because up until recently the issue appeared to be moot, as despite the 
high starting point concentration the modeling predicted a 2020 annual 
concentration of 15.0 [micro]g/m\3\, which attains the 1997 annual 
PM<INF>2.5</INF> NAAQS. The discovery of the EC-OC reversal described 
above brings the issue to the fore because there is no

[[Page 6972]]

room for the increase it causes in the 2020 Madera design value.
    The fact that 2011-2013 Madera BAM concentrations are higher than 
values at the Fresno FRM and other sites does not in itself prove they 
are incorrect; it is conceivable that unknown sources were contributing 
there. Also, the later agreement between the lower Madera BAM and FRM 
concentrations could be explained as sources that are now emitting 
less, or that are contributing less at the monitor due to different 
wind patterns. Nevertheless, the mismatch with the historical gradient 
pattern, the unexpectedly but only temporarily high readings that 
declined after an adjustment in operation, and the current lower FRM 
readings do suggest that the 2011 Madera concentrations were anomalous. 
EPA believes that the 2011-2013 readings at the Madera site are not 
known to be representative of air quality for Madera and not 
sufficiently certain to drive the SJV control strategy, or to 
invalidate the conclusion of the attainment demonstration that the SJV 
will attain the 1997 annual NAAQS in 2020.
    CARB explored two alternative scenarios to estimate annual average, 
ambient PM<INF>2.5</INF> values in 2020 for the Madera site.\403\ Under 
the first scenario, CARB substituted the 2014 design value of 15.8 
[micro]g/m\3\ at the Madera site for its 2013 design value and 
estimated that the 2020 Madera design value would be 14.1 [micro]g/
m\3\. For the second scenario, CARB substituted the annual 2011 data 
from the Merced-Coffee Road site, adjusted upward to reflect the 
typically slightly higher values at Madera, resulting in an estimated 
2020 Madera design value of 14.9 [micro]g/m\3\. Both scenarios are 
reasonable alternatives to estimating the 2020 Madera design value for 
the SJV attainment planning purposes for the 1997 annual 
PM<INF>2.5</INF> NAAQS. Accordingly, the Bakersfield-Planz site, which 
would have a corrected 2020 design value of 15.0 [micro]g/m\3\, would 
become the design value monitor for the SJV, as would be expected under 
the historic observation of a north-to-south increasing gradient of 
concentrations.\404\
---------------------------------------------------------------------------

    \403\ Letter from K. Magliano, CARB to A. Steckel, EPA Region 9, 
August 12, 2015, Attachment B, pp. 3-4.
    \404\ Note that if the unexpectedly high concentrations seen in 
2011-2013 are due to real phenomena affecting air quality, then they 
would be expected to occur again at some point in the intervening 
years between now and the projected attainment year of 2020. If they 
do occur again, then they would influence the monitored attainment 
status at that time, and hence any request for SJV to be designated 
attainment.
---------------------------------------------------------------------------

    EPA accepts the scaled modeling approach of the attainment 
demonstration in the 2015 PM<INF>2.5</INF> Plan, which was the product 
of extended discussion between EPA, ARB, and SJVUAPCD. Based on our 
review of the modeling approach and results, we propose to conclude 
that the 2015 PM<INF>2.5</INF> Plan adequately demonstrates that the 
SJV area will attain the 1997 annual PM<INF>2.5</INF> NAAQS by December 
31, 2020 and attain the 1997 24-hour PM<INF>2.5</INF> NAAQS by December 
31, 2018. We recommend that CARB reassess the status of the modeled 
attainment of the 1997 24-hour and annual PM<INF>2.5</INF> NAAQS as 
part of the new modeling required for SIP revisions addressing the 2006 
and 2012 PM<INF>2.5</INF> NAAQS.
Evaluation of Bakersfield-Planz Data Exclusion for May 5, 2013
    As described in the 2015 PM<INF>2.5</INF> Plan, the State and 
District based the attainment demonstration on ambient measurements 
during 2011-2013.\405\ The 24-hour PM<INF>2.5</INF> concentration of 
167.3 [micro]g/m\3\ measured at the Bakersfield-Planz monitoring site 
(AQS ID: 06-029-0016) on May 5, 2013 was not included in the attainment 
demonstration analyses due to its unrepresentativeness for purposes of 
attainment planning for the SJV as a whole. Therefore, the modeled 
projections for the 2020 annual PM<INF>2.5</INF> design values and 2018 
24-hour design values \406\ and the discussion of the modeling results 
in Appendix F, section F.4 of the Plan are based on data that exclude 
the May 5, 2013 24-hour data point from the Bakersfield-Planz 
monitoring site.
---------------------------------------------------------------------------

    \405\ 2015 PM<INF>2.5</INF> Plan, Appendix F, p F-4.
    \406\ 2015 PM<INF>2.5</INF> Plan, Appendix F, Table F-1.
---------------------------------------------------------------------------

    The Plan provides an assessment of the representativeness of this 
data for purposes of inclusion in the attainment demonstration analyses 
\407\ and concludes that:
---------------------------------------------------------------------------

    \407\ 2015 PM<INF>2.5</INF> Plan, Appendix F, Attachment B: 
Assessment of the Representativeness of the PM<INF>2.5</INF> Value 
Recorded at the Bakersfield-Planz Monitoring Site on May 5, 2013.
---------------------------------------------------------------------------

    ``In summary, comparison of the 167.3 [micro]g/m\3\ concentration 
measured on May 5, 2013, to values typical for this season as well as 
comparison to values measured throughout the Valley on the same day, 
combined with the record high fugitive dust and elemental species 
concentrations, indicate that the monitor was impacted by microscale 
sources that are not representative of the neighborhood spatial scale 
the monitor is intended to represent. Therefore, this value is not 
included in modeling analysis for the San Joaquin Valley 2015 
PM<INF>2.5</INF> Plan.''
    The assessment provided in the Plan \408\ based this conclusion on: 
(1) Representativeness of Bakersfield-Planz PM<INF>2.5</INF> data; 
\409\ (2) potential fugitive dust sources affecting the Bakersfield-
Planz site; \410\ and (3) meteorology at the Bakersfield-Planz 
site.\411\
---------------------------------------------------------------------------

    \408\ 2015 PM<INF>2.5</INF> Plan, Appendix F, Attachment B.
    \409\ 2015 PM<INF>2.5</INF> Plan, Appendix F, Attachment B, 
Section B.
    \410\ 2015 PM<INF>2.5</INF> Plan, Appendix F, Attachment B, 
Section C.
    \411\ 2015 PM<INF>2.5</INF> Plan, Appendix F, Attachment B, 
Section D.
---------------------------------------------------------------------------

    Information provided regarding the representativeness of 
Bakersfield-Planz data included analyses of San Joaquin Valley seasonal 
PM<INF>2.5</INF> concentrations \412\ and elemental species 
composition.\413\ The assessment provided PM<INF>2.5</INF> data on the 
highest concentrations throughout the Valley since 2000 and shows that 
the May 5, 2013 Bakersfield-Planz value was unusually high compared to 
historical trends since 2000. Further, this data point was also 
unusually high compared to other sites in the San Joaquin Valley on the 
same day.\414\ The species composition analyses show that the primary 
content of the particulate matter was fugitive dust and that the level 
of the dust was over four times higher than the next highest value 
observed in the entire California network based on 14 years of 
available data. In addition, total elemental species and other chemical 
species were found to be unusually high.
---------------------------------------------------------------------------

    \412\ 2015 PM<INF>2.5</INF> Plan, Appendix F, pp. F-11 to F-13.
    \413\ Id., pp. F-13 to F-14.
    \414\ Id., pp. F-12 to F-13.
---------------------------------------------------------------------------

    The State and District's assessment of potential fugitive dust 
sources affecting the Bakersfield-Planz site was based on an evaluation 
of aerial photos to identify sources and field investigation by 
District enforcement staff.\415\ The assessment found no documented 
dust violations at any nearby sources and identify the likely source of 
the dust was from the open areas immediately adjacent to the monitor, 
suggesting a localized microscale impact.
---------------------------------------------------------------------------

    \415\ Id., pp. F-14 to F-16.
---------------------------------------------------------------------------

    The third part of the assessment evaluated meteorology at the 
Bakersfield-Planz Monitoring Site.\416\ Wind speeds on May 5, 2013 were 
compared to other days in May 2013 and also to other high wind days at 
the Bakersfield-Planz site. The wind speeds were in excess of 25 mph 
for over eight hours on May 5, 2013. The meteorology indicates that 
Bakersfield-Planz experienced a high wind event on May

[[Page 6973]]

5, 2013 that was unusual in terms of wind speed and duration.
---------------------------------------------------------------------------

    \416\ Id., pp. F-17 to F-18.
---------------------------------------------------------------------------

    Overall, EPA agrees with the evidence provided that the 
Bakersfield-Planz monitor was affected by an unusual high wind dust 
event on May 5, 2013 that resulted in anomalous PM<INF>2.5</INF> 
concentrations on that day. EPA believes that it is appropriate to omit 
this data point from the attainment demonstration based on EPA's 2013 
guidance on exceptional events.\417\ Regarding the inclusion of event-
affected data for attainment demonstrations, EPA's 2013 guidance says:
---------------------------------------------------------------------------

    \417\ Memorandum from Steven D. Page, Director Office of Air 
Quality Planning and Standards, to Regional Air Directors, I-X, 
``Interim Guidance to Implement Requirements for the Treatment of 
Air Quality Monitoring Data Influenced by Exceptional Events,'' May 
10, 2013 (``2013 Exceptional Events Guidance'').
---------------------------------------------------------------------------

    ``An air agency incorporating the event-related concentration in a 
design value used for a prospective attainment demonstration might seem 
to need more emission reductions to attain the NAAQS by its attainment 
deadline than is actually the case. The EPA plans to more formally 
address this topic on a pollutant/NAAQS basis, the first of which will 
be ozone guidance in the preamble of a soon-to-be-proposed rulemaking 
on SIP requirements for areas designated nonattainment for the 2008 
ozone NAAQS. Until the planned guidance for a pollutant and NAAQS of 
interest is issued, air agencies should consult with their EPA regional 
office if they face this situation.'' \418\
---------------------------------------------------------------------------

    \418\ Id.
---------------------------------------------------------------------------

    EPA reviewed PM<INF>2.5</INF> data in AQS for the SJV since 2010 
and identified four days flagged with high wind exceptional event 
requests for exclusion. These PM<INF>2.5</INF> high wind dust events do 
not appear to be recurring events and their inclusion in the attainment 
demonstration therefore would not accurately reflect the effect of 
controls during more typical conditions at the Bakersfield-Planz 
monitoring site.\419\ Based on these reviews, EPA agrees with the 
State's and District's assertion that the May 5, 2013 concentrations at 
Bakersfield-Planz were due to an unusual PM<INF>2.5</INF> high wind 
dust event that would not be appropriate to include in the attainment 
demonstration.
---------------------------------------------------------------------------

    \419\ EPA also reviewed PM<INF>10</INF> data in AQS for the SJV 
since 2010 and identified eight days flagged with high wind 
exceptional event request for exclusion, which indicate that 
PM<INF>10</INF> high wind dust events recur and should be subject to 
reasonable controls in accordance with the 2013 Exceptional Events 
Guidance.
---------------------------------------------------------------------------

    In addition to EPA's 2013 guidance on exceptional events, EPA also 
considered the monitoring requirements for PM<INF>2.5</INF>. In 
particular, 40 CFR part 58, Appendix D, section 4.71(b) specifies for 
PM<INF>2.5</INF>:
    ``The required monitoring stations or sites must be sited to 
represent area-wide air quality. These sites can include sites 
collocated at PAMS. These monitoring stations will typically be at 
neighborhood or urban-scale; however, micro-or middle-scale 
PM<INF>2.5</INF> monitoring sites that represent many such locations 
throughout a metropolitan area are considered to represent area-wide 
air quality.''
    Based on the information provided in the Plan, EPA agrees that the 
Bakersfield-Planz concentrations on May 5, 2013 appear to have been 
affected by a localized event; therefore, it was neither representative 
of neighborhood scale concentrations, nor occurring at many locations. 
EPA agrees with the State and District that the May 5, 2013 
concentrations at Bakersfield-Planz were not representative of area-
wide, typical PM<INF>2.5</INF> concentrations in San Joaquin Valley.
    Based on the technical analyses provided in the Plan and EPA 
guidance and requirements as cited in this section, EPA agrees with the 
State and District that the May 5, 2013 Bakersfield-Planz 24-hour 
PM<INF>2.5</INF> data point resulted from a localized, anomalous event 
that can be omitted from the attainment demonstration analyses.
Evaluation of Control Strategy
    The attainment control strategy in the 2015 PM<INF>2.5</INF> Plan 
consists of State and District baseline measures that continue to 
achieve emission reductions and four additional control measures that 
the District either recently revised or, in one case, has committed to 
revise in 2016. With respect to baseline measures for stationary and 
area sources, the District identified the source categories under its 
jurisdiction and their projected emission levels in Appendix B, section 
B.2.2 (``Emissions Inventory Documentation'') and described each of the 
District measures that apply to these source categories in section 
B.2.2.3 of the Plan (``Control Profiles'').\420\ All but one of the 55 
District control measures listed in section B.2.2.3 of the Plan have 
been approved into the California SIP.\421\
---------------------------------------------------------------------------

    \420\ 2015 PM<INF>2.5</INF> Plan, Appendix B, pp. B-23 to B-31. 
See also, within this section, Table B-8 (``District Rules Included 
in the SIP Inventory'').
    \421\ See EPA Region 9's Web site for information on District 
control measures that have been approved into the California SIP, 
available at: http://yosemite.epa.gov/r9/r9sips.nsf/Agency?ReadForm&count=500&state=California&cat=San+Joaquin+Valley+Unified+APCD-Agency-Wide+Provisions. Of the District measures 
identified in Appendix B of the Plan, only Rule 4691 (``Vegetable 
Oil Processing Operations''), which limits VOC emissions from 
vegetable oil processing operations, is not currently approved into 
the California SIP. EPA approved a previous version of this rule 
(Rule 461.2) into the SIP on January 18, 1994 (59 FR 2535).
---------------------------------------------------------------------------

    With respect to mobile sources, the State identified the source 
categories and described the EMFAC2014 emission factor model used to 
project their future emission levels in Appendix B, sections B.2.2.4 
through B.2.2.7 of the Plan.\422\ As explained in section V.D of this 
proposed rule, in a separate rulemaking, EPA is proposing to approve 
CARB's submitted waiver measures into the SIP and intends to finalize 
that rulemaking before taking final action on the 2015 PM<INF>2.5</INF> 
Plan.
---------------------------------------------------------------------------

    \422\ 2015 PM<INF>2.5</INF> Plan, Appendix B, pp. B-31 to B-35.
---------------------------------------------------------------------------

    Table 8 below summarizes the emission reductions needed in the SJV 
to attain the 1997 24-hour and annual PM<INF>2.5</INF> NAAQS by the end 
of 2018 and 2020, respectively.

     Table 8--Summary of Direct PM2.5 and NOX Emission Reductions Needed for the 2015 PM2.5 Plan Attainment
                                                  Demonstration
----------------------------------------------------------------------------------------------------------------
                                                  24-hour Standard Attainment by   Annual Standard Attainment by
                                                     2018 (tpd annual average)       2020 (tpd winter average)
                                                 ---------------------------------------------------------------
                                                       PM2.5            NOX            PM2.5            NOX
----------------------------------------------------------------------------------------------------------------
A 2012 emissions inventory \a\..................            61.0           318.5            66.0           332.2
B Emissions inventory after baseline measures...            57.7           213.9            62.8           206.9
C Emissions inventory needed to attain..........            54.4           213.7            60.8           206.5
D Total emission reductions needed by attainment             6.6           104.8             5.2           125.7
 year (A--C)....................................
----------------------------------------------------------------------------------------------------------------
Source: 2015 PM2.5 Plan, CARB Staff Report, Tables 1 and 2, p. 9, except as otherwise noted.
\a\ 2015 PM2.5 Plan, Appendix B, Tables B-1 and B-2.


[[Page 6974]]

    The Plan identifies four District measures that will achieve 
additional emission reductions beyond baseline measures and contribute 
to expeditious attainment of the 1997 PM<INF>2.5</INF> NAAQS.\423\ 
First, Rule 4308 (``Boilers, Steam Generators, and Process Heaters 
0.075 to <2 MMBtu/hr''), as amended November 14, 2013, limits 
NO<INF>X</INF> emissions from boilers, steam generators, and process 
heaters sized between 0.075 and 2 MMBtu/hr and is projected to achieve 
0.0007 tpd of NO<INF>X</INF> emission reductions by 2018 and 0.0011 tpd 
of NO<INF>X</INF> emission reductions by 2020.\424\ EPA approved this 
rule into the California SIP on February 12, 2015.\425\
---------------------------------------------------------------------------

    \423\ 2015 PM<INF>2.5</INF> Plan, CARB Staff Report, Tables 1 
and 2, p. 9.
    \424\ 2015 PM<INF>2.5</INF> Plan, Chapter 7, p. 7-3 and CARB 
Staff Report at p. 9.
    \425\ 80 FR 7803 (February 12, 2015).
---------------------------------------------------------------------------

    Second, the District has committed to amend Rule 4692 (``Commercial 
Charbroiling'') in 2016 to add requirements for under-fired 
charbroilers, with an anticipated compliance date in 2017.\426\ Rule 
4692, as approved into the SIP on November 3, 2011, regulates emissions 
from chain-driven charbroilers but does not regulate under-fired 
charbroilers.\427\ The District projects that its anticipated revisions 
to Rule 4692 to regulate under-fired charbroilers will achieve an 
additional 0.4 tpd of direct PM<INF>2.5</INF> emission reductions in 
2018 and 2020.\428\ EPA recently proposed to approve this commitment 
into the California SIP.\429\
---------------------------------------------------------------------------

    \426\ 2015 PM<INF>2.5</INF> Plan, Chapter 7, section 7.1.2, p. 
7-6 and SJVUAPCD Governing Board Resolution 15-4-7A (April 16, 2015) 
at paragraph 7.
    \427\ 76 FR 68103 (November 3, 2011).
    \428\ 2015 PM<INF>2.5</INF> Plan, Chapter 7 at p. 7-6.
    \429\ 80 FR 1816 at 1833 and 1844 (January 13, 2015).
---------------------------------------------------------------------------

    Emission reductions of 0.4 tpd of direct PM<INF>2.5</INF> represent 
6.1% of the total PM<INF>2.5</INF> emission reductions needed to attain 
the 1997 24-hour standard by 2018 and 7.7% of the total 
PM<INF>2.5</INF> emission reductions needed to attain the 1997 annual 
standard by 2020.\430\ These are limited portions of the total 
PM<INF>2.5</INF> emission reductions needed for expeditious attainment 
of the 1997 PM<INF>2.5</INF> standards in the SJV. Based on the 
District's history of timely meeting similar rule commitments (see 
section V.E.3 of this preamble), we find that the District is capable 
of fulfilling this commitment. We also find that the commitment to 
adopt the amended rule by 2016 is for a reasonable and appropriate 
timeframe given the need for PM<INF>2.5</INF> emission reductions to 
attain by 2018 and 2020. Accordingly, we propose to approve this rule 
commitment as part of the control strategy in the 2015 PM<INF>2.5</INF> 
Plan. For a more detailed discussion of this commitment and the 
District's evaluations to date, see the EPA's SJV Rules TSD.
---------------------------------------------------------------------------

    \430\ 2015 p.m.2.5 Plan, CARB Staff Report, Tables 1 and 2, p. 
9, and Appendix B (``Emissions Inventory''), Tables B-1 and B-2.
---------------------------------------------------------------------------

    Third, the District projects that Rule 4901 (``Wood Burning 
Fireplaces and Wood Burning Heaters''), as amended September 18, 2014, 
will achieve 2.9 tpd of direct PM<INF>2.5</INF> emission reductions by 
2018 and 1.6 tpd of direct PM<INF>2.5</INF> emission reductions by 
2020. Specifically, the District's 2014 rule amendment to lower the 
rule's ``no burn threshold'' from 30 [micro]g/m\3\ to 20 [micro]g/m\3\ 
(24-hour average ambient PM<INF>2.5</INF> concentration) for non-EPA 
certified, non-District registered wood burning devices is projected to 
achieve a winter 24-hour average of 2.2 tpd of direct PM<INF>2.5</INF> 
emission reductions by 2018 and an annual average of 1.1 tpd of direct 
PM<INF>2.5</INF> emission reductions by 2020.\431\ The 2015 
PM<INF>2.5</INF> Plan relies on Rule 4901 for an additional 0.7 tpd of 
direct PM<INF>2.5</INF> emission reductions (winter 24-hour average) by 
2018 and an additional 0.5 tpd of direct PM<INF>2.5</INF> emission 
reductions (annual average) by 2020 resulting from homeowners replacing 
high-emitting fireplaces and stoves with low-emitting, EPA-certified 
devices.\432\ The EPA recently proposed to approve Rule 4901 into the 
California SIP.\433\
---------------------------------------------------------------------------

    \431\ The District calculated these estimates using its 
estimates of direct PM<INF>2.5</INF> emission reductions for the 
120-day wood burning season covered by the rule and ratios of 120/
365 days and 120/180 days for the annual average and winter (24-
hour) average emission reductions, respectively. See SJVUAPCD, 
``Final Staff Report for Amendments to the District's Residential 
Wood Burning Program,'' Appendix B, (``Emission Reduction Analysis 
Amendments to Residential Wood Burning Program'') at B-12, September 
18, 2014.
    \432\ The 0.7 tpd and 0.5 tpd emission reduction estimates 
assume that 14% of devices subject to Rule 4901 will be replaced by 
2018 and that 20% of such devices will be replaced by 2020, 
respectively. For a more detailed discussion of these emission 
reduction estimates, see the EPA's SJV Rules TSD.
    \433\ 80 FR 58637 (September 30, 2015).
---------------------------------------------------------------------------

    Finally, the District projects that Rule 4905 (``Natural Gas-Fired, 
Fan-Type Residential Central Furnaces''), as amended January 22, 2015, 
will achieve 0.2 tpd of NO<INF>X</INF> emission reductions by 2018 and 
0.4 tpd of NO<INF>X</INF> emission reductions by 2020.\434\ This rule 
includes a mitigation fee option that allows manufacturers to sell non-
compliant furnaces for 36-month transition periods ranging from 2015 to 
2021, depending on unit type.\435\ Based on information in the 
District's staff report on Rule 4905, the District estimates emission 
reductions of 0.105 tpd of NO<INF>X</INF> per year from three of the 
four types of units, which have compliance dates ranging from April 1, 
2015 through October 1, 2016.\436\
---------------------------------------------------------------------------

    \434\ 2015 p.m.2.5 Plan, CARB Staff Report, Tables 1 and 2, p. 
9.
    \435\ SJVUAPCD, ``Final Staff Report Amendments to Rule 4905 
(Natural Gas-Fired, Fan-Type Central Furnaces,'' January 22, 2015, 
p. 9. See also EPA's proposed rule on Rule 4905. 80 FR 68484 
(November 5, 2015).
    \436\ SJVUAPCD Rule 4905 as amended January 22, 2015, Table 1 
(``NO<INF>X</INF> Emission Limits and Compliance Schedule''). See 
also, SJVUAPCD, ``Final Staff Report Amendments to Rule 4905 
(Natural Gas-Fired, Fan-Type Central Furnaces,'' January 22, 2015, 
Appendix B, pp. B-9.
---------------------------------------------------------------------------

    The EPA recently proposed to approve Rule 4905 into the California 
SIP.\437\ Because the sale of non-compliant units is allowed to varying 
degrees in 2018 by manufacturers paying mitigation fees, we propose to 
credit Rule 4905 with 0.035 tpd of NO<INF>X</INF> emission reductions 
in 2018 rather than the 0.105 tpd of emission reductions identified in 
the District's staff report for the rule. The amount we propose to not 
credit (i.e., 0.16 tpd of NO<INF>X</INF>) represents only 0.2% of the 
total winter average NO<INF>X</INF> reduction from 2012 to 2018.\438\ 
Using the 24-hour PM<INF>2.5</INF> sensitivity of 0.08 [micro]g/m\3\ 
per ton of NO<INF>X</INF> emission reduction at the projected 2018 
design value site of Bakersfield-California St., as modeled for the 
2012 PM<INF>2.5</INF> Plan,\439\ this would result in an ambient 24-
hour PM<INF>2.5</INF> concentration increase of about 0.013 [micro]g/
m\3\.\440\ This represents a minimal effect on ambient PM<INF>2.5</INF> 
levels and, therefore, does not undermine the Plan's demonstration of 
attainment of the 1997 24-hour PM<INF>2.5</INF> standard by December 
31, 2018.
---------------------------------------------------------------------------

    \437\ 80 FR 68484 (November 5, 2015).
    \438\ Percent of total winter average NO<INF>X</INF> emission 
reductions = 0.16 tpd/104.8 tpd = 0.2%.
    \439\ 2015 PM<INF>2.5</INF> Plan, WOEA, Table B-2 (``Modeled 
PM<INF>2.5</INF> air quality benefit per ton of valley-wide 
precursor emission reductions''), p. A-27.
    \440\ Increase in ambient 24-hour PM<INF>2.5</INF> concentration 
= (0.08 [micro]g/m\3\/ton of NO<INF>X</INF> emission reduction) * 
(0.16 tpd) = 0.013 [micro]g/m\3\.
---------------------------------------------------------------------------

    In sum, the attainment demonstration in the 2015 PM<INF>2.5</INF> 
Plan relies on numerous State and District baseline regulations and 
four additional District measures that EPA has either approved or 
proposed to approve into the California SIP, all of which collectively 
are projected to achieve emission reductions sufficient for the SJV 
area to attain the 1997 24-hour PM<INF>2.5</INF> standard by 2018 and 
the 1997 annual PM<INF>2.5</INF> standard by 2020. Table 9 provides a 
summary of the emission reductions from the four additional District 
measures that we propose to credit toward the Plan's attainment control 
strategy.

[[Page 6975]]



 Table 9--Summary of EPA Proposed Emission Reduction Credits for Additional District Control Measures Needed for
                                  the 2015 PM2.5 Plan Attainment Demonstration
----------------------------------------------------------------------------------------------------------------
                                                   Annual Standard Attainment by  24-hour Standard Attainment by
                                                     2020 (tpd annual average)       2018 (tpd winter average)
            District control measure             ---------------------------------------------------------------
                                                       PM2.5            NOX            PM2.5            NOX
----------------------------------------------------------------------------------------------------------------
Rule 4308.......................................             0.0          0.0011             0.0          0.0007
Rule 4692.......................................             0.4             0.0             0.4             0.0
Rule 4901.......................................             1.6             0.0             2.9             0.0
Rule 4905.......................................             0.0             0.4             0.0           0.035
----------------------------------------------------------------------------------------------------------------
Source: 2015 PM2.5 Plan, CARB Staff Report, Tables 1 and 2, p. 9.

Conclusion
    As discussed above, the 2015 PM<INF>2.5</INF> Plan's air quality 
modeling demonstrates that the SJV will attain the 1997 24-hour 
PM<INF>2.5</INF> standard of 65 [micro]g/m\3\ by December 31, 2018 and 
the 1997 annual PM<INF>2.5</INF> standard of 15.0 [micro]g/m\3\ by 
December 31, 2020. This demonstration is based on expeditious 
implementation of the State's and District's BACM and MSM control 
strategy for stationary, area, and mobile sources in the 2015 
PM<INF>2.5</INF> Plan, together with the District's commitment to 
achieve additional PM<INF>2.5</INF> emission reductions from under-
fired charbroilers through amendments to Rule 4692. Based on these 
evaluations, we propose to determine that the 2015 PM<INF>2.5</INF> 
Plan provides for attainment of the 1997 24-hour and annual 
PM<INF>2.5</INF> standards by the most expeditious alternatives dates 
practicable, consistent with the requirements of CAA sections 
189(b)(1)(A).

F. Reasonable Further Progress and Quantitative Milestones

1. Requirements for Reasonable Further Progress and Quantitative 
Milestones
    CAA section 172(c)(2) requires nonattainment area plans to provide 
for reasonable further progress (RFP). In addition, CAA section 189(c) 
requires PM<INF>2.5</INF> nonattainment area SIPs to include 
quantitative milestones to be achieved every three years until the area 
is redesignated to attainment and which demonstrate reasonable further 
progress (RFP), as defined in CAA section 171(1). Section 171(1) 
defines RFP as ``such annual incremental reductions in emissions of the 
relevant air pollutant as are required by [Part D] or may reasonably be 
required by the Administrator for the purpose of ensuring attainment of 
the applicable [NAAQS] by the applicable date.'' Neither subpart 1 nor 
subpart 4 of part D, title I of the Act requires that a set percentage 
of emissions reductions be achieved in any given year for purposes of 
satisfying the RFP requirement.
    RFP has historically been met by showing annual incremental 
emission reductions sufficient generally to maintain at least linear 
progress toward attainment by the applicable deadline.\441\ As 
discussed in EPA guidance in the Addendum, requiring linear progress in 
reductions of direct PM<INF>2.5</INF> and any individual precursor in a 
PM<INF>2.5</INF> plan may be appropriate in situations where:
---------------------------------------------------------------------------

    \441\ Addendum at 42015.
---------------------------------------------------------------------------

    <bullet> the pollutant is emitted by a large number and range of 
sources,
    <bullet> the relationship between any individual source or source 
category and overall air quality is not well known,
    <bullet> a chemical transformation is involved (e.g., secondary 
particulate significantly contributes to PM<INF>2.5</INF> levels over 
the standard), and/or
    <bullet> the emission reductions necessary to attain the 
PM<INF>2.5</INF> standard are inventory-wide.\442\
---------------------------------------------------------------------------

    \442\ Id.
---------------------------------------------------------------------------

    The Addendum states that requiring linear progress may be less 
appropriate in other situations, such as:
    <bullet> where there are a limited number of sources of direct 
PM<INF>2.5</INF> or a precursor,
    <bullet> where the relationships between individual sources and air 
quality are relatively well defined, and/or
    <bullet> where the emission control systems utilized (e.g., at 
major point sources) will result in swift and dramatic emission 
reductions.
    In nonattainment areas characterized by any of these latter 
conditions, RFP may be better represented as step-wise progress as 
controls are implemented and achieve significant reductions soon 
thereafter. For example, if an area's nonattainment problem can be 
attributed to a few major sources, EPA guidance indicates that ``RFP 
should be met by `adherence to an ambitious compliance schedule' which 
is likely to periodically yield significant emission reductions of 
direct PM<INF>2.5</INF> or a PM<INF>2.5</INF> precursor.'' \443\
---------------------------------------------------------------------------

    \443\ Addendum at 42015.
---------------------------------------------------------------------------

    Plans for PM<INF>2.5</INF> nonattainment areas should include 
detailed schedules for compliance with emission regulations in the area 
and provide corresponding annual emission reductions to be realized 
from each milestone in the schedule.\444\ In reviewing an attainment 
plan under subpart 4, EPA evaluates whether the annual incremental 
emission reductions to be achieved are reasonable in light of the 
statutory objective of timely attainment. Although early implementation 
of the most cost-effective control measures is often appropriate, 
states should consider both cost-effectiveness and pollution reduction 
effectiveness when developing implementation schedules for their 
control measures and may implement measures that are more effective at 
reducing PM<INF>2.5</INF> earlier to provide greater public health 
benefits.\445\
---------------------------------------------------------------------------

    \444\ Addendum at 42016.
    \445\ Id.
---------------------------------------------------------------------------

    Section 189(c) requires that attainment plans include quantitative 
milestones in order to demonstrate RFP. The purpose of the quantitative 
milestones is to allow periodic evaluation of the area's progress 
towards attainment of the NAAQS through the RFP requirements. Thus, the 
EPA determines an area's compliance with RFP in conjunction with 
determining its compliance with the quantitative milestone requirement. 
Because RFP is an annual emission reduction requirement and the 
quantitative milestones are to be achieved every three years, when a 
state demonstrates compliance with the quantitative milestone 
requirement, it will demonstrate that RFP has been achieved during each 
of the relevant three years. Quantitative milestones should provide an 
objective means to evaluate progress toward attainment meaningfully, 
e.g., through imposition of emission controls in the attainment plan 
and the requirement to quantify those required emission reductions. The 
CAA also requires milestone reports (due 90 days after each milestone), 
and these reports should include calculations and any assumptions made 
concerning how RFP

[[Page 6976]]

has been met, e.g., through quantification of emission reductions to 
date.\446\
---------------------------------------------------------------------------

    \446\ Id. at 42016, 42017.
---------------------------------------------------------------------------

    The CAA does not specify the starting point for counting the three-
year periods for quantitative milestones under CAA section 189(c). In 
the General Preamble and Addendum, EPA interpreted the CAA to require 
that the starting point for the first three-year period be the due date 
for the Moderate area plan submission.\447\ In keeping with this 
historical approach, EPA is proposing to establish December 31, 2014 as 
the starting point for the first 3-year period under CAA section 189(c) 
for the 1997 PM<INF>2.5</INF> standards in the SJV. This date was the 
due date established in the EPA's June 2, 2014 Deadline and 
Classification Rule for the State's submission of any additional 
attainment-related SIP elements necessary to satisfy the subpart 4 
Moderate area requirements for the 1997 PM<INF>2.5</INF> standards in 
the SJV area.\448\ December 31, 2017 and December 31, 2020 would then 
be the milestone dates that the Serious Area plan must address, at 
minimum. The EPA believes that establishing December 31, 2017 as the 
first quantitative milestone date is an appropriate means for 
implementing the requirements of subpart 4 prospectively.
---------------------------------------------------------------------------

    \447\ General Preamble at 13539, Addendum at 42016.
    \448\ 79 FR 31566 (June 2, 2014) (final rule establishing 
subpart 4 moderate area classifications and deadline for related SIP 
submissions) (``Classification and Deadline Rule''). Although the 
Classification and Deadline Rule did not affect any action that EPA 
had previously taken under CAA section 110(k) on a SIP for a 
PM<INF>2.5</INF> nonattainment area, EPA noted that states may need 
to submit additional SIP elements to fully comply with the 
applicable requirements of subpart 4, even for areas with previously 
approved PM<INF>2.5</INF> attainment plans, and that the deadline 
for any such additional plan submissions was December 31, 2014. Id. 
at 31569.
---------------------------------------------------------------------------

2. RFP Demonstration and Quantitative Milestones in the 2015 
PM<INF>2.5</INF> Plan
    The RFP demonstration and quantitative milestones appear in Chapter 
6, section 6.3 (pp. 6-6 to 6-8) of the 2015 PM<INF>2.5</INF> Plan. 
Further discussion of the RFP demonstration, particularly with respect 
to ammonia, and the establishment of dates, content, and a reporting 
commitment for quantitative milestones, appears in CARB's Staff Report 
(pp. 25-26). In addition, by letter dated December 15, 2015, CARB's 
Executive Officer committed to submit a SIP revision to supplement the 
quantitative milestone portion of the 2015 PM<INF>2.5</INF> Plan by 
December 31, 2016 (``QM Letter'').\449\
---------------------------------------------------------------------------

    \449\ Letter from R. Corey, Executive Officer, CARB to J. 
Blumenfeld, Regional Administrator, U.S. EPA Region 9, December 15, 
2015.
---------------------------------------------------------------------------

    The Plan estimates that emissions of direct PM<INF>2.5</INF>, 
NO<INF>X</INF>, and SO<INF>X</INF> will decline from the 2012 base year 
to 2020 and states that emissions of each of these pollutants will 
remain below the levels needed to show ``generally linear progress'' 
from 2012 to 2020, the year that the Plan projects to be the earliest 
practicable attainment date for the 1997 annual PM<INF>2.5</INF> 
standard.\450\ The Plan's emissions inventory shows that direct 
PM<INF>2.5</INF>, NO<INF>X</INF>, and SO<INF>X</INF> are emitted by a 
large number and range of sources in the SJV and the emission 
reductions needed for these pollutants are inventory wide.\451\ The 
District followed the procedures in the 2007 PM<INF>2.5</INF> 
Implementation Rule to calculate 2014 and 2017 RFP targets (or 
``benchmark'' emission levels) for direct PM<INF>2.5</INF>, 
NO<INF>X</INF>, and SO<INF>X</INF> and then concluded that projected 
emission levels for each pollutant, based on its adopted control 
strategy, would be below those targets in both milestone years.\452\
---------------------------------------------------------------------------

    \450\ 2015 PM<INF>2.5</INF> Plan, Chapter 6, Table 6-8 (``RFP 
Target Demonstration (2014 and 2017)''), p. 6-8.
    \451\ 2015 PM<INF>2.5</INF> Plan, Appendix B.
    \452\ 2015 PM<INF>2.5</INF> Plan, pp. 6-6 to 6-8.
---------------------------------------------------------------------------

    The BACM control strategy that provides the basis for these 
emissions projections is described in Chapters 5 and 7 and Appendices C 
and D of the Plan. For stationary and area sources, the Plan highlights 
several rules that are projected to contribute to attainment of the 
PM<INF>2.5</INF> standards.\453\ For example, Rule 4354 (``Glass 
Melting Furnaces'') controls emissions of NO<INF>X</INF>, 
SO<INF>X</INF>, and PM from industrial glass manufacturing--the largest 
source of SO<INF>X</INF> emissions in the San Joaquin Valley--and its 
emissions projections are presented in Appendix C as part of the Plan's 
BACM and MSM analysis.\454\ Similarly, Rule 4901 (``Wood Burning 
Fireplaces and Wood Burning Heaters'') controls emissions from 
residential wood burning and addresses the largest combustion source of 
direct PM<INF>2.5</INF>.\455\ Measures to control dust sources of 
direct PM<INF>2.5</INF> are also presented in the Plan's BACM and MSM 
analyses and reflected in the Plan's baseline emission projections. 
Examples of such measures include Rule 4550 (``Conservation Management 
Practices'') \456\ and Rule 8061 (``Paved and Unpaved Roads'').\457\ 
For mobile sources, the Plan lists numerous CARB regulations and 
discusses the key regulations that limit the emission of direct 
PM<INF>2.5</INF> and NO<INF>X</INF> from on-road and non-road mobile 
sources.\458\ For instance, the regulations that apply to the two 
largest sources of NO<INF>X</INF> in the San Joaquin Valley--heavy, 
heavy-duty diesel trucks and farm equipment--are discussed in Appendix 
C and their emission projections are presented in the Plan's emissions 
inventory.\459\
---------------------------------------------------------------------------

    \453\ 2015 PM<INF>2.5</INF> Plan, Chapter 7, Section 7.1.1, pp. 
7-2 to 7-6.
    \454\ 2015 PM<INF>2.5</INF> Plan, Chapter 7, pp. 7-3 to 7-4 and 
Appendix C, p. C-102.
    \455\ 2015 PM<INF>2.5</INF> Plan, Chapter 7, p. 7-4 and Appendix 
C, p. C-157.
    \456\ 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-108.
    \457\ 2015 PM<INF>2.5</INF> Plan, Appendix C, p. C-194.
    \458\ 2015 PM<INF>2.5</INF> Plan, Chapter 7, Section 7.1.3, pp. 
7-6 to 7-13.
    \459\ 2015 PM<INF>2.5</INF> Plan, Appendix D, pp. D-8 to D-12 
(for heavy heavy duty trucks) and D-15 (for farm equipment) and 
Appendix B, p. B-7.
---------------------------------------------------------------------------

    With respect to ammonia, the 2015 PM<INF>2.5</INF> Plan projects an 
increase in annual average ammonia emissions from 329.5 tpd in 2012 to 
358.0 tpd in 2020.\460\ The Plan states that both NO<INF>X</INF> and 
ammonia participate in forming ammonium nitrate (i.e., secondary 
PM<INF>2.5</INF>) but that NO<INF>X</INF> emission reductions are an 
order of magnitude more effective at reducing ambient PM<INF>2.5</INF> 
than ammonia reductions.\461\ Based on the relative insensitivity of 
ambient PM<INF>2.5</INF> levels to ammonia reductions compared to 
NO<INF>X</INF> reductions, the Plan states that ammonia is not a 
significant precursor to ambient PM<INF>2.5</INF> in the SJV \462\ and 
thus that an RFP demonstration for ammonia is not required.\463\ The 
Plan also states that NO<INF>X</INF> emission levels are projected to 
be well below the levels needed to show generally linear progress 
toward attainment. The CARB Staff Report provides additional analysis 
by converting the increase in ammonia emissions into ``NO<INF>X</INF> 
equivalent'' emission levels (using a ``NO<INF>X</INF> equivalency'' 
calculation method) and demonstrating that the ``NO<INF>X</INF> 
equivalent'' emissions level continues to show linear progress toward 
attainment from 2012 to 2020.\464\
---------------------------------------------------------------------------

    \460\ 2015 PM<INF>2.5</INF> Plan, Appendix B, p. B-19.
    \461\ Id. See also, 2015 PM<INF>2.5</INF> Plan, Chapter 2, p. 2-
27, which concludes the District's analysis of the relationship 
between ammonia emissions and ambient PM<INF>2.5</INF> levels by 
stating that ``ammonia reductions at the Bakersfield-California site 
are only. . . 10% as effective as NO<INF>X</INF> reductions.''
    \462\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, section 2.6 
(``Insignificant Precursors to PM<INF>2.5</INF> Concentrations in 
the Valley'').
    \463\ 2015 PM<INF>2.5</INF> Plan, CARB Staff Report, p. 26.
    \464\ 2015 PM<INF>2.5</INF> Plan, CARB Staff Report, pp. 25-26.
---------------------------------------------------------------------------

    The NO<INF>X</INF> equivalency method used in the Plan relies on 
the sensitivity of ambient PM<INF>2.5</INF> levels to decreases in 
ammonia emissions compared to decreases in NO<INF>X</INF> emissions, as 
modeled at the Bakersfield-California monitoring site. The Plan states 
that in the San Joaquin Valley ammonia emission reductions are only 10% 
as effective as NO<INF>X</INF> emission reductions, with a

[[Page 6977]]

relative sensitivity factor of 0.1.\465\ Stated alternatively, this is 
a 1:10 NO<INF>X</INF> for ammonia trading ratio, i.e., it takes 1 tpd 
of NO<INF>X</INF> emissions to match the ambient effect of 10 tpd of 
ammonia in this area. The State calculates the change in ammonia 
emissions from the base year (2012) to each RFP milestone year \466\ 
(2014 and 2017), and multiplies it by the trading ratio to calculate a 
NO<INF>X</INF> increase equivalent to the ammonia increase, which the 
State then adds to the NO<INF>X</INF> emissions inventory for each RFP 
milestone year to calculate the total NO<INF>X</INF> decrease and 
ammonia increase expressed as ``NO<INF>X</INF> equivalent'' emission 
levels.\467\ The CARB Staff Report states that the total NO<INF>X</INF> 
equivalent emissions levels are below the linear reductions in 
NO<INF>X</INF> necessary to demonstrate RFP and, therefore, that the 
RFP requirement is met, despite the projected increase in the ammonia 
inventory.
---------------------------------------------------------------------------

    \465\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, p. 2-27. Note that 
Bakersfield-California is projected to be the design value monitor 
for the SJV in 2018 with respect to the 1997 24-hour 
PM<INF>2.5</INF> standard. 2015 PM<INF>2.5</INF> Plan, Appendix F, 
Table F-1 (``Projected 2018 and 2020 Design Values''), p. F-7.
    \466\ We use ``RFP milestone year'' to mean each year for which 
the Plan provides an RFP analysis and related emissions projections.
    \467\ That is, (NO<INF>X</INF> emissions) <INF>2017</INF> + 
[(NH<INF>3</INF> emissions) <INF>2017</INF>-(NH<INF>3</INF> 
emissions) <INF>2012</INF>] * 0.1 = (total NO<INF>X</INF> equivalent 
emissions) <INF>2017</INF>. Using values from the 2015 
PM<INF>2.5</INF> Plan, the 17.5 tpd increase in ammonia emissions 
from 2012 to 2017 is equivalent to a 1.8 tpd increase in 
NO<INF>X</INF> emissions, as follows: 235.7 + [347.0-329.5]*0.1 = 
237.5 tpd. See CARB Staff Report, p. 26, Table 12.
---------------------------------------------------------------------------

    Control measures for ammonia sources are described in Appendix C of 
the Plan. For example, ammonia controls resulting from Rule 4570 
(``Confined Animal Facilities''), Rule 4565 (``Biosolids, Animal 
Manure, and Poultry Litter Operations''), and Rule 4566 (``Organic 
Material Composting'') are discussed at length in section C.41 of 
Appendix C and their emission projections are presented collectively 
under farming operations in the Plan's emissions inventory.\468\ We 
discuss these control measures more fully in section V.D of this 
preamble (``Best Available Control Measures and Most Stringent 
Measures'') and in the EPA's SJV Rules TSD.
---------------------------------------------------------------------------

    \468\ 2015 PM<INF>2.5</INF> Plan, Appendix C, Section C.41, pp. 
C-240 to C-281 and Appendix B, p. B-17.
---------------------------------------------------------------------------

    With respect to quantitative milestones, the CARB Staff Report 
states that the Plan identifies RFP emissions levels for direct 
PM<INF>2.5</INF>, NO<INF>X</INF>, and SO<INF>X</INF> for 2014 and 2017 
that show generally linear progress towards attaining the annual 
standard in 2020, and that ``[t]hese emission levels for 2017 along 
with the 2020 attainment emission levels serve as the quantitative 
milestones required under the Act.'' \469\ CARB addresses the projected 
increase in ammonia emissions over the planning period by evaluating 
those emissions in light of the atmospheric response to NO<INF>X</INF> 
and ammonia emissions in the San Joaquin Valley area and concluding 
that ``the combined emission levels of NO<INF>X</INF> and ammonia that 
are projected to occur through the 2020 attainment year provide for the 
required generally linear air quality progress.'' \470\ The CARB Staff 
Report also states California's commitment to provide letters to EPA 
``reporting that the emission inventory milestones have been met and 
the status of any emission reduction commitments,'' and to provide 
these letters by March 31, 2018 for the 2017 milestone and by March 31, 
2021 for the 2020 milestone.\471\
---------------------------------------------------------------------------

    \469\ 2015 PM<INF>2.5</INF> Plan, CARB Staff Report, p. 26.
    \470\ Id.
---------------------------------------------------------------------------

    Additionally, the QM Letter contains the State's commitment to 
submit, by December 31, 2016, a SIP revision that supplements the 
quantitative milestone portion of the 2015 PM<INF>2.5</INF> Plan by 
identifying specific quantitative milestones to be achieved by the 2017 
RFP milestone year and 2020 attainment year that demonstrate reasonable 
further progress toward timely attainment of the PM<INF>2.5</INF> 
NAAQS. The QM Letter states that this SIP revision will include the 
following milestones to track implementation of control measures and 
emissions levels at each milestone year: (1) A list of measures in the 
Plan's BACM/BACT and MSM control strategy and key implementation 
requirements through 2017 and 2020, including compliance milestones for 
the State's Truck and Bus Rule and the District's residential wood 
burning rule (Rule 4901), (2) compliance with the State's and 
District's enforceable commitments in the Plan by the 2017 milestone 
date, and (3) updated emissions inventories for both 2017 and 
2020.\472\ The QM Letter also states that the SIP revision will 
identify appropriate air quality quantitative milestones for 2017 and 
2020 designed to evaluate air quality progress resulting from 
implementation of the Plan's control strategy, including an assessment 
of monitored ambient PM<INF>2.5</INF> concentrations and other 
variables affecting ambient PM<INF>2.5</INF> concentrations in each of 
those years.\473\
---------------------------------------------------------------------------

    \472\ QM Letter, pp. 1-2.
    \473\ Id., p. 2.
---------------------------------------------------------------------------

3. Evaluation and Proposed Actions
Reasonable Further Progress Demonstration
    With respect to direct PM<INF>2.5</INF>, NO<INF>X</INF>, and 
SO<INF>2</INF>, we agree that ``generally linear progress'' is an 
appropriate measure of RFP for the 1997 PM<INF>2.5</INF> NAAQS in the 
SJV area given that, as the Plan documents, direct PM<INF>2.5</INF>, 
NO<INF>X</INF>, and SO<INF>X</INF> are emitted by a large number and 
range of sources in the SJV, the emission reductions needed for these 
pollutants are inventory wide,\474\ and secondary particulates 
contribute significantly to ambient PM<INF>2.5</INF> levels in the SJV 
area.\475\
---------------------------------------------------------------------------

    \474\ 2015 PM<INF>2.5</INF> Plan, Appendix B.
    \475\ 2015 PM<INF>2.5</INF> Plan, Chapter 5, Section 5.4.1 
(``Significance Determination Approach'').
---------------------------------------------------------------------------

    The 2015 PM<INF>2.5</INF> Plan documents the State's conclusion 
that all BACM, BACT, and MSM for these pollutants are being implemented 
as expeditiously as practicable and identifies projected levels of 
direct PM<INF>2.5</INF>, NO<INF>X</INF>, and SO<INF>X</INF> emissions 
in 2014 and 2017 that reflect full implementation of the State's and 
District's BACM/BACT and MSM control strategy for these 
pollutants.\476\ For example, Rule 4550 (``Conservation Management 
Practices'') was adopted in 2004 and its requirements to control 
PM<INF>10</INF> emissions (including PM<INF>2.5</INF>) from on-field 
crop and animal feeding operations are fully implemented.\477\ These 
operations represent the largest dust sources of direct 
PM<INF>2.5</INF> in the San Joaquin Valley.\478\ More recently, 
SJVUAPCD revised Rule 4901 (``Wood Burning Fireplaces and Wood Burning 
Heaters'') in September 2014 by strengthening the District's 
curtailment program for residential wood burning, thereby further 
limiting emissions from San Joaquin Valley's largest combustion source 
of direct PM<INF>2.5</INF>.\479\ These rule amendments provide part of 
the incremental emission reductions of direct PM<INF>2.5</INF> from the 
2014 to 2017 RFP milestone years and through the 2018 and 2020 
attainment years.\480\
---------------------------------------------------------------------------

    \476\ 2015 PM<INF>2.5</INF> Plan, Chapter 6, Section 6.3, and 
Appendix B. See also our discussion of BACM/BACT in section V.D of 
this proposed rule.
    \477\ 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-106 to C-
107.
    \478\ 2015 PM<INF>2.5</INF> Plan, Chapter 5, Table 5-2, pp. 5-7 
to 5-8. See also 2015 PM<INF>2.5</INF> Plan, Appendix B, p. B-2,
    \479\ 2015 PM<INF>2.5</INF> Plan, Chapter 7, p. 7-4 and Appendix 
C, p. C-156. See also 2015 PM<INF>2.5</INF> Plan, Appendix B, p. B-
2.
    \480\ 2015 PM<INF>2.5</INF> Plan, CARB Staff Report, p. 9.

---------------------------------------------------------------------------

[[Page 6978]]

    The Truck and Bus Regulation and Drayage Truck Regulation became 
effective in 2011 and have rolling compliance deadlines based on truck 
engine model year. These and other regulations applicable to heavy duty 
diesel trucks will continue to reduce emissions of diesel particulate 
matter and NO<INF>X</INF> through the RFP and attainment planning 
years.\481\ For instance, model year 1994 and 1995 heavy heavy duty 
diesel truck engines must be upgraded to meet the 2010 model year truck 
engine emission standards by 2016, and model year 1996-1999 engines 
must by upgraded by January 1, 2020.\482\ The emission reductions from 
these rules represent the largest portion of the NO<INF>X</INF> 
emission reductions upon which the Plan's attainment and RFP 
demonstrations rely.\483\ With respect to SO<INF>X</INF> emissions, 
Rule 4354 (``Glass Melting Furnaces'') was amended in May 2011, 
establishing SO<INF>X</INF> emission limits with compliance deadlines 
through January 1, 2014.\484\ This rule will achieve emission 
reductions through the 2017 RFP milestone year and 2018 and 2020 
attainment years. As explained in section V.D of this preamble, we are 
proposing to find that the State and District are implementing these 
BACM, BACT and MSM provisions for the 1997 PM<INF>2.5</INF> NAAQS as 
expeditiously as practicable.
---------------------------------------------------------------------------

    \481\ 2015 PM<INF>2.5</INF> Plan, Chapter 7, p. 7-9 to 7-10 and 
Appendix D, pp. D-8 to D-11.
    \482\ Title 13, California Code of Regulations, Section 2025 
(``Regulation to Reduce Emissions of Diesel Particulate Matter, 
Oxides of Nitrogen and Other Criteria Pollutants, from In-Use Heavy-
Duty Diesel-Fueled Vehicles''), paragraphs (e), (f), and (g), 
effective December 14, 2011. See also EPA's final rule approving 
CARB's Truck and Bus Rule. 77 FR 20308 at 20309-20310 (April 4, 
2012).
    \483\ 2015 PM<INF>2.5</INF> Plan, Appendix B, p. B-7.
    \484\ 2015 PM<INF>2.5</INF> Plan, Chapter 7, pp, 7-3 to 7-4.
---------------------------------------------------------------------------

    Additionally, the method used to calculate RFP target (or 
``benchmark'') emission levels for direct PM<INF>2.5</INF>, 
NO<INF>X</INF>, and SO<INF>2</INF> is generally consistent with the 
method provided in the 2007 PM<INF>2.5</INF> Implementation Rule (40 
CFR 51.1009(f)). We note that the 2015 PM<INF>2.5</INF> Plan calculates 
the 2014 and 2017 RFP benchmark emission levels using 2020 attainment 
emissions levels that are not consistent with the attainment targets 
presented in CARB's Staff Report.\485\ We have, however, re-calculated 
the RFP benchmark emissions levels for these years using the attainment 
targets found in the CARB Staff Report,\486\ as shown in Table 10 
below. The EPA's calculations indicate that the Plan's projected 2014 
and 2017 emission levels for direct PM<INF>2.5</INF>, NO<INF>X</INF>, 
and SO<INF>X</INF> are below the RFP benchmark emission levels for 
these years.\487\
---------------------------------------------------------------------------

    \485\ 2015 PM<INF>2.5</INF> Plan, Chapter 6, Table 6-6, p. 6-7 
vs. CARB Staff Report, p. 9.
    \486\ 2015 PM<INF>2.5</INF> Plan, CARB Staff Report, Table 1, p. 
9.
    \487\ For example, the 2017 RFP benchmark for direct 
PM<INF>2.5</INF> should account for five years' worth of annual 
incremental reductions and is calculated as (2012 emission 
inventory)-(annual increment reduction)*5 = 66.0 tpd-(0.65 tpd/yr)*5 
= 62.75 tpd. The projected emissions inventory for direct 
PM<INF>2.5</INF> in 2017 is 62.5 tpd, which is less than this RFP 
benchmark.

                                             Table 10--EPA Calculation of 2015 PM2.5 Plan RFP Demonstration
                                                             [tpd, based on annual averages]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                               2012            2020           Annual                           2014                            2017
                                             Emissions      Attainment      incremental      2014 RFP        Projected       2017 RFP        Projected
                                           inventory \a\     target b      reduction \c\     Benchmark     emissions \d\     Benchmark     emissions \d\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Direct PM2.5............................            66.0            60.8            0.65            64.7            63.3           62.75            62.5
NOX.....................................           332.2           206.5           15.71          300.78           284.2          253.63           235.7
SOX.....................................             8.1             7.8            0.04            8.03             7.4            7.91             7.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ 2015 PM2.5 Plan, Chapter 6, Table 6-6, p. 6-7.
\b\ 2015 PM2.5 Plan, CARB Staff Report, Table 1, p. 9.
\c\ Annual incremental reduction = (2012 emissions inventory-2020 attainment target)/(2020-2012).
\d\ 2015 PM2.5 Plan, Chapter 6, Table 6-8, p. 6-8.

    With respect to ammonia, the 2015 PM<INF>2.5</INF> Plan shows an 
8.6% increase in total ammonia emissions during the 2012 to 2020 
period.\488\ Unlike the wide range of sources emitting direct 
PM<INF>2.5</INF>, NO<INF>X</INF>, and SO<INF>2</INF> in the Valley, 
emissions of ammonia are almost entirely from three source categories: 
confined animal facilities (CAFs), fertilizer application, and 
composting, with more than half of all emissions coming from CAFs.\489\ 
Collectively, these three categories emit 95% of all ammonia emissions 
in the 2012 annual average base year inventory.\490\
---------------------------------------------------------------------------

    \488\ 2015 PM<INF>2.5</INF> Plan, Appendix B, Table B-5.
    \489\ In the inventories provided in Appendix B of the Plan, 
emissions from these sources are found in the categories ``Farming 
Operations'', ``Pesticides/Fertilizers'', and ``Other (Waste 
Disposal)'', respectively.
    \490\ 2015 PM<INF>2.5</INF> Plan, Appendix B, Table B-5 
(``Ammonia''), pp. B-16 to B-19. The three categories comprising 
this 95% of emissions in the ammonia emission inventory are Other 
(Waste Disposal), Pesticides/Fertilizers, and Farming Operations.
---------------------------------------------------------------------------

    Several District measures already in the SIP for the SJV area 
control ammonia emissions from two of these source categories. District 
Rule 4570 (``Confined Animal Facilities'') required implementation of 
control measures to reduce VOCs in 2008 and required full compliance by 
affected sources by mid-2012.\491\ Many of the VOC control measures 
have an ammonia co-benefit, and the District estimates a 100 tpd 
reduction in ammonia from this rule, which have been accounted for in 
the emissions inventory of the 2015 PM<INF>2.5</INF> Plan.\492\ The 
Plan also indicates that implementation of District Rule 4565 
(``Biosolids, Animal Manure, and Poultry Litter Operations''), adopted 
March 15, 2007,\493\ and Rule 4566 (``Organic Material Composting 
Operations''), adopted August 18, 2011,\494\ resulted in some ammonia 
reductions, but these reductions are not reflected in the base year or 
baseline inventories. As discussed in section V.D of this proposed 
rule, we are proposing to determine that each of these measures 
implements BACM and MSM for the control of ammonia as a precursor to 
PM<INF>2.5</INF> in the San Joaquin Valley for purposes of the 1997 
PM<INF>2.5</INF> NAAQS.
---------------------------------------------------------------------------

    \491\ 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-240 to C-
243.
    \492\ 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-240 to C-
241. See also, Memo to file, ``Call with California Air Resources 
Board regarding VOC and ammonia emissions inventory,'' R. Mays, EPA 
Region 9, September 30, 2015.
    \493\ 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-276.
    \494\ 2015 PM<INF>2.5</INF> Plan, Appendix C, pp. C-272 to C-
273.
---------------------------------------------------------------------------

    The statement in the Plan that ammonia is an insignificant 
precursor in the SJV area is based on the State's analysis of the 
relative sensitivity of ambient PM<INF>2.5</INF> levels to changes in 
ammonia emissions as compared to NO<INF>X</INF> emissions. The State 
relies in part on information previously presented in

[[Page 6979]]

the 2012 PM<INF>2.5</INF> Plan for the 2006 24-hour PM<INF>2.5</INF> 
standard to justify a NO<INF>X</INF> for ammonia trading ratio of 0.1. 
The 2012 PM<INF>2.5</INF> Plan contains modeling results and states 
that ``reductions in ammonia are approximately nine times less 
effective than NO<INF>X</INF>.'' \495\ The 2012 PM<INF>2.5</INF> Plan 
also gives ammonia and NO<INF>X</INF> sensitivities (ambient 
PM<INF>2.5</INF> changes in [mu]g/m\3\ per tpd of emission reductions), 
based on modeling of the ambient effect of a 25% area-wide reduction in 
each pollutant.\496\ The ratios of these sensitivities give an ammonia-
NO<INF>X</INF> relative sensitivity ratio, or NO<INF>X</INF> for 
ammonia trading ratio, of 0.10 for the Bakersfield-California site, and 
0.11 (about 1/9) for the Bakersfield-Planz site.\497\
---------------------------------------------------------------------------

    \495\ 2012 PM<INF>2.5</INF> Plan, Appendix G (``Weight of 
Evidence Analysis''), p. 64.
    \496\ 2012 PM<INF>2.5</INF> Plan, Appendix G, Table 7, p. 65.
    \497\ The difference between these two figures is about 0.1% 
when carried through in the calculation of the NO<INF>X</INF> 
equivalent of ammonia.
---------------------------------------------------------------------------

    The 2015 PM<INF>2.5</INF> Plan similarly reflects the State's 
conclusion that ammonia emission reductions are about 10% as effective 
as NO<INF>X</INF> reductions in decreasing ambient PM<INF>2.5</INF> 
concentrations.\498\ We have reviewed the modeling analysis from which 
the State and District derived the 0.1 NO<INF>X</INF> for ammonia 
trading ratio and propose to find that this ratio is a reasonable 
estimate of the sensitivity of ambient PM<INF>2.5</INF> to ammonia 
reductions relative to NO<INF>X</INF> reductions, at least for the 
Bakersfield-California and Bakersfield-Planz monitoring sites for which 
the analysis was performed. For further discussion of our evaluation of 
this trading ratio for purposes of the Plan's RFP demonstration, see 
section IV.A of the EPA's Interpollutant Trading Ratios TSD.
---------------------------------------------------------------------------

    \498\ 2015 PM<INF>2.5</INF> Plan, Chapter 2, pp. 2-27 (stating 
that ``ammonia reductions at the Bakersfield-California site are . . 
. only 10% as effective as NO<INF>X</INF> reductions''); see also 
CARB Staff Report, p. 26 and Table 12 (expressing NO<INF>X</INF> and 
ammonia emissions combined as ``NO<INF>X</INF> equivalent'' emission 
levels).
---------------------------------------------------------------------------

    The Bakersfield-California site is projected to be the design value 
site for the 1997 24-hour PM<INF>2.5</INF> standard in 2018,\499\ which 
addresses the requirement of 40 CFR 51.1009(h) that an equivalent 
method for demonstrating RFP must do so at the design value monitoring 
site within the nonattainment area. As discussed in section V.E.5 of 
this proposed rule, although the State had initially projected the 
Madera site to be the design value site for the 1997 annual 
PM<INF>2.5</INF> standard in 2020, based on weight of evidence, it now 
appears the Bakersfield-Planz site will most likely be the design value 
site for the annual PM<INF>2.5</INF> standard in 2020. Either way, the 
0.1 ammonia-NO<INF>X</INF> relative sensitivity factor is adequate for 
the RFP demonstration because it is derived from modeling analyses that 
account for emission projections at both of these Bakersfield 
monitoring sites.
---------------------------------------------------------------------------

    \499\ 2015 PM<INF>2.5</INF> Plan, Appendix F, Table F-1 
(``Projected 2018 and 2020 Design Values''), p. F-7.
---------------------------------------------------------------------------

    Taking the ammonia emissions increases into account, the 
NO<INF>X</INF> equivalent emission levels presented in the Plan \500\ 
for the 2014 and 2017 RFP milestone years fall below the benchmark RFP 
NO<INF>X</INF> emissions levels for those same years.\501\ In essence, 
the substantial reduction of NO<INF>X</INF> emissions that is projected 
to result from the Plan's control strategy (i.e., 37.8% reduction) from 
2012 to 2020 \502\ appears to more than offset the increase in ammonia 
emissions (i.e., 8.6% increase) that is projected to occur during that 
same period.\503\ More specifically, as shown in Table 11, taking into 
account the increase in ammonia emissions during the 2012 to 2020 
period, the NO<INF>X</INF> equivalent emission levels projected in the 
Plan for the 2014 and 2017 RFP milestone years are 5-6% lower than the 
levels representing generally linear NO<INF>X</INF> emission reductions 
for those same years, thus showing NO<INF>X</INF> emission reductions 
at a rate faster than the benchmark scenario.
---------------------------------------------------------------------------

    \500\ 2015 PM<INF>2.5</INF> Plan, CARB Staff Report, p. 26.
    \501\ This approach is consistent with the regulatory option of 
40 CFR 51.1009(g)(2) that the RFP plan demonstrate emission levels 
that are ``projected to result in a generally equivalent improvement 
in air quality by the milestone year as would be achieved under the 
benchmark RFP plan.''
    \502\ 2015 PM<INF>2.5</INF> Plan, Appendix B, Table B-2, p. B-8 
and CARB Staff Report, p. 9. Emissions of NO<INF>X</INF> are project 
to decrease from 332.2 tpd in 2012 to 206.5 tpd in 2020 (i.e., a 
decrease of 125.7 tpd or 37.8%).
    \503\ 2015 PM<INF>2.5</INF> Plan, Appendix B, Table B-5, p. B-
19. Emissions of ammonia are project to increase 329.5 tpd in 2012 
to 358.0 tpd in 2020 (i.e., an increase of 28.5 tpd or 8.6%).

 Table 11--Comparison of NOX Equivalent Emissions to RFP Linear Emissions Level for NOX for RFP Milestone Years
                                               [tpd, except row G]
----------------------------------------------------------------------------------------------------------------
                                                                               2012         2014         2017
----------------------------------------------------------------------------------------------------------------
A.........................................  NOX Emissions................        332.2        284.2        235.7
B.........................................  Ammonia Emissions............        329.5        336.2        347.0
C.........................................  NOX equivalent of ammonia      ...........          0.7          1.8
                                             increase.
D.........................................  Total NOX Equivalent           ...........        284.9        237.5
                                             Emissions (A+C).
E.........................................  RFP Linear Level for NOX.....  ...........        300.9        253.9
F.........................................  Total NOX Equivalent Emission  ...........         16.0         16.4
                                             Reductions Beyond RFP Linear
                                             Level (E-D).
G.........................................  % Below RFP Linear Level (F/   ...........         5.3%         6.5%
                                             E).
----------------------------------------------------------------------------------------------------------------
Source: 2015 PM2.5 Plan, CARB Staff Report, Table 12, p. 26.

    As discussed in section V.C of this proposed rule, we are proposing 
to determine that VOCs do not contribute significantly to ambient 
PM<INF>2.5</INF> levels that exceed the 1997 PM<INF>2.5</INF> standards 
in the SJV and, accordingly, that no RFP demonstration for VOCs is 
necessary for purposes of the 1997 PM<INF>2.5</INF> standards in this 
area.
    In sum, the 2015 PM<INF>2.5</INF> Plan demonstrates that emissions 
of direct PM<INF>2.5</INF>, NO<INF>X</INF> and SO<INF>X</INF> will be 
reduced at rates representing generally linear progress toward 
attainment, and that the increase in ammonia emissions over the 2012-
2020 planning period will be more than offset by substantial 
NO<INF>X</INF> emission reductions exceeding the amounts necessary to 
show generally linear progress toward attainment. The Plan also 
demonstrates that all BACM, BACT and MSM that provide the bases for the 
direct PM<INF>2.5</INF>, NO<INF>X</INF>, SO<INF>X</INF>, and ammonia 
emissions projections in the RFP analysis in the Plan are being 
implemented as expeditiously as practicable. Accordingly, we propose to 
determine that the Plan requires the annual incremental reductions in 
emissions of direct PM<INF>2.5</INF> and relevant PM<INF>2.5</INF> 
precursors that are necessary for the purpose of ensuring attainment of 
the 1997 24-hour and annual PM<INF>2.5</INF>

[[Page 6980]]

standards by 2018 and 2020, respectively, in accordance with the 
requirements of CAA sections 171(1) and 172(c)(2).
Quantitative Milestones
    Although the RFP emission levels identified in the Plan for the 
2017 and 2020 milestone years represent generally linear progress 
toward attainment by 2018 and 2020, the Plan as originally submitted in 
June 2015 does not identify an objective means for evaluating the 
area's compliance with these emission targets or progress toward 
attainment, other than through 2017 and 2020 emissions levels and 
CARB's commitment to report on the ``status of any emission reduction 
commitments'' in the Plan. We note that the Plan contains only one 
emission reduction commitment: To adopt amendments to District Rule 
4692 (``Commercial Charbroiling'') in 2016 and to achieve 0.4 tpd of 
direct PM<INF>2.5</INF> emission reductions through implementation of 
this amended rule or a substitute rule achieving equivalent emission 
reductions.\504\ Such a milestone would not provide an adequate means 
to evaluate progress toward attainment of the PM<INF>2.5</INF> NAAQS in 
the SJV, consistent with RFP requirements.
---------------------------------------------------------------------------

    \504\ 2015 PM<INF>2.5</INF> Plan, Chapter 7, p. 7-6, and 
SJVUAPCD Governing Board Resolution 15-4-7A, paragraph 7.
---------------------------------------------------------------------------

    In the QM Letter, however, CARB committed to adopt and submit, no 
later than December 31, 2016, a revision to the 2015 PM<INF>2.5</INF> 
Plan that identifies specific milestones demonstrating progress toward 
attainment of the 24-hour PM<INF>2.5</INF> standard by December 31, 
2018 and the annual PM<INF>2.5</INF> standard by December 31, 2020. The 
QM Letter describes the specific components of this SIP revision that 
CARB will adopt and submit by December 31, 2016, including milestones 
to track implementation of specific SIP control measures and 
commitments, and air quality milestones to be achieved by the 2017 RFP 
milestone year and 2020 attainment year. Two of the control measures 
identified in the QM Letter are responsible for a significant portion 
of the NO<INF>X</INF> and direct PM<INF>2.5</INF> emission reductions 
necessary for RFP and attainment: CARB's Truck and Bus Rule and the 
District's residential wood burning rule (Rule 4901). Emissions from 
heavy heavy duty trucks and residential wood burning are the largest 
combustion sources of NO<INF>X</INF> and direct PM<INF>2.5</INF> in San 
Joaquin Valley, and the Truck and Bus Rule and Rule 4901 achieve the 
largest amounts of NO<INF>X</INF> and direct PM<INF>2.5</INF> emission 
reductions, respectively, identified in the Plan's attainment 
demonstration.\505\ The District's commitment in the Plan to amend Rule 
4692 (``Commercial Charbroiling'') in 2016 and to achieve 0.4 tpd of 
direct PM<INF>2.5</INF> emission reductions through implementation of 
this amended rule or a substitute rule achieving equivalent emission 
reductions \506\ also accounts for a portion of the direct 
PM<INF>2.5</INF> emission reductions necessary for RFP and attainment 
in the Plan.\507\ These implementation milestones, together with the 
updated emission inventories and air quality milestones for 2017 and 
2020 that the State has also committed to identify as quantitative 
milestones in the SIP revision, would provide an objective means to 
evaluate the area's progress in achieving not only the incremental 
emissions reductions but also the incremental air quality improvements 
necessary to attain the 24-hour and annual PM<INF>2.5</INF> NAAQS by 
2018 and 2020, respectively.
---------------------------------------------------------------------------

    \505\ For stationary and area sources, ``Residential Fuel 
Combustion'' is the largest combustion source of direct 
PM<INF>2.5</INF> in San Joaquin Valley (e.g., 9.4 tpd of the total 
2012 winter average emissions of 61.0 tpd) and CARB's Staff Report 
identifies Rule 4901 as achieving the largest portion of the direct 
PM<INF>2.5</INF> emission reductions for attaining 1997 
PM<INF>2.5</INF> NAAQS (e.g., 2.9 tpd of the Plan's 6.6 tpd total 
winter average emission reductions from 2012 to 2018). 2015 
PM<INF>2.5</INF> Plan, Appendix B, p. B-2 and CARB Staff Report, p. 
9. For all sources, ``Heavy Heavy Duty Diesel Trucks (HHDV)'' are 
the largest source of NO<INF>X</INF> in the San Joaquin Valley 
(e.g., 120.5 tpd of the total 2012 annual average emissions of 332.2 
tpd) and the Plan estimates that the largest emission reductions of 
NO<INF>X</INF> during the attainment planning period, for which the 
Truck and Bus Rule is a significant driver, will result from this 
source category (e.g., 59.2 tpd of the 125.7 tpd annual average 
emission reductions from 2012 to 2020). 2015 PM<INF>2.5</INF> Plan, 
Appendix B, p. B-7 and CARB Staff Report, p. 9.
    \506\ 2015 PM<INF>2.5</INF> Plan, Chapter 7, p. 7-6, and 
SJVUAPCD Governing Board Resolution 15-4-7A, paragraph 7.
    \507\ The Plan estimates that the amendments to Rule 4692 will 
achieve 0.4 tpd of the Plan's 5.2 tpd total annual average emission 
reductions of direct PM<INF>2.5</INF> from 2012 to 2020. 2015 
PM<INF>2.5</INF> Plan, CARB Staff Report, p. 9.
---------------------------------------------------------------------------

    Under section 110(k)(4) of the Act, EPA may conditionally approve a 
plan revision based on a commitment by the State to adopt specific 
enforceable measures by a date certain but not later than 1 year after 
the date of the plan approval. Based on CARB's commitments to submit 
the specific SIP revisions identified in the QM Letter by December 31, 
2016, as discussed above, we propose to conditionally approve the 
quantitative milestone component of the 2015 PM<INF>2.5</INF> Plan.
    We note that, consistent with the requirements of CAA section 
189(c)(2) as interpreted in longstanding EPA policy, each of the 
milestone reports due March 31, 2018 (for the December 31, 2017 
milestone date) and March 31, 2021 (for the December 31, 2020 milestone 
date) should include technical support sufficient to document 
completion statistics for appropriate milestones, e.g., calculations 
and any assumptions made concerning emission reductions to date.\508\
---------------------------------------------------------------------------

    \508\ Addendum at 42017.
---------------------------------------------------------------------------

G. Contingency Measures

1. Requirements for Contingency Measures
    Under CAA section 172(c)(9), PM<INF>2.5</INF> attainment plans must 
include contingency measures to be implemented if an area fails to meet 
RFP (``RFP contingency measures'') or fails to attain the 
PM<INF>2.5</INF> standards by the applicable attainment date 
(``attainment contingency measures''). Under subpart 4, however, the 
EPA interprets section 172(c)(9) in light of the specific requirements 
for particulate matter nonattainment areas. Section 189(b)(1)(A) 
differentiates between attainment plans that provide for timely 
attainment and those that demonstrate that attainment is impracticable. 
The 2015 PM<INF>2.5</INF> Plan is a Serious area plan that demonstrates 
attainment of the 1997 24-hour PM<INF>2.5</INF> NAAQS by December 31, 
2018 and attainment of the 1997 annual PM<INF>2.5</INF> NAAQS by 
December 31, 2020, and thus, must include contingency measures for RFP 
and attainment.
    The purpose of contingency measures is to continue progress in 
reducing emissions while a state revises its SIP to meet the missed RFP 
requirement or to correct continuing nonattainment. The principle 
requirements for contingency measures are: \509\
---------------------------------------------------------------------------

    \509\ General Preamble at 13543-13544 and Addendum at 42014-
42015.
---------------------------------------------------------------------------

    <bullet> Contingency measures must be fully adopted rules or 
control measures that are ready to be implemented quickly upon failure 
to meet RFP or failure of the area to meet the relevant NAAQS by the 
applicable attainment date.
    <bullet> The SIP should contain trigger mechanisms for the 
contingency measures, specify a schedule for implementation, and 
indicate that the measures will be implemented without further action 
by the State or by the EPA. In general, we expect all actions needed to 
affect full implementation of the measures to occur within 60 days 
after EPA notifies the State of a failure.
    <bullet> The contingency measures should consist of other control 
measures for the area that are not already relied upon to

[[Page 6981]]

demonstrate attainment (e.g., to meet RACM/RACT, BACM/BACT, or MSM 
requirements) or to meet RFP.
    <bullet> The measures should provide for emissions reductions 
equivalent to approximately one year of reductions needed for RFP 
calculated as the overall level of reductions needed to demonstrate 
attainment divided by the number of years from the base year to the 
attainment year.
    Finally, we note that contingency measures can include federal, 
state, and local measures that are already scheduled for implementation 
or already implemented that provide for additional emissions reductions 
that are not relied on to demonstrate RFP or attainment. In other 
words, contingency measures are intended to achieve reductions over and 
beyond those relied on in the RFP and attainment demonstrations. 
Nothing in the CAA precludes a state from implementing such measures 
before they are triggered by a failure to meet RFP or a failure to 
attain by the applicable attainment date. EPA has approved numerous 
SIPs under this interpretation.\510\
---------------------------------------------------------------------------

    \510\ See, for example, 62 FR 15844 (April 3, 1997) (direct 
final rule approving Indiana ozone SIP revision); 62 FR 66279 
(December 18, 1997) (final rule approving Illinois ozone SIP 
revision); 66 FR 30811 (June 8, 2001) (direct final rule approving 
Rhode Island ozone SIP revision); 66 FR 586 (January 3, 2001) (final 
rule approving District of Columbia, Maryland, and Virginia ozone 
SIP revisions); and 66 FR 634 (January 3, 2001) (final rule 
approving Connecticut ozone SIP revision); see also LEAN v. EPA, 382 
F.3d 575 (5th Cir. 2004) (upholding contingency measures that were 
previously required and implemented where they were in excess of the 
attainment demonstration and RFP SIP).
---------------------------------------------------------------------------

2. Contingency Measures in the 2015 PM<INF>2.5</INF> Plan
    The 2015 PM<INF>2.5</INF> Plan addresses the contingency measure 
requirement in Chapter 6, section 6.4 (``Contingency Measures'') of the 
Plan and in the CARB Staff Report, pages 26-27. Chapter 6, section 6.4 
addresses contingency measure requirements for the 2014 and 2017 RFP 
milestone years and for the 2020 attainment year by discussing emission 
reductions to be achieved by already adopted measures, voluntary 
incentive programs, and inter-pollutant trading between 
PM<INF>2.5</INF> and NO<INF>X</INF> for the 2020 attainment year. The 
CARB Staff Report, p. 26-27, provides a brief statement on contingency 
measures for the 2018 attainment year for the 24-hour PM<INF>2.5</INF> 
NAAQS and identifies several additional control measures to address the 
2020 attainment year for the annual PM<INF>2.5</INF> NAAQS. Chapter 6 
states that a year's worth of annual average emission reductions needed 
to demonstrate RFP (``One year's worth of RFP'') is calculated by 
taking the overall level of emission reductions needed to demonstrate 
attainment and dividing it by the number of years between the base year 
and attainment year.\511\ Table 6-9 of the Plan (Contingency Emissions 
Reductions Target (tpd)) is reproduced below:
---------------------------------------------------------------------------

    \511\ 2015 PM<INF>2.5</INF> Plan, Chapter 6, Section 6.4, p. 6-
9, Table 6-9.

------------------------------------------------------------------------
                                                        Contingency Need
                                                         = ``One year's
                                                         worth of RFP''
------------------------------------------------------------------------
Direct PM2.5..........................................               0.4
NOX...................................................              15.7
SOX...................................................               0
------------------------------------------------------------------------
Source: 2015 PM2.5 Plan, Chapter 6, Section 6.4, Table 6-9.

    Chapter 6 of the Plan identifies emission reductions to be achieved 
by the control strategy in the Plan in 2014 and 2017 that the District 
considers ``surplus'' to those reductions necessary to demonstrate RFP. 
The District states that these emission reductions are thus available 
to meet the contingency measure requirement.\512\ Table 6-10 of the 
Plan (Reductions Surplus to RFP for Contingency (tpd)), reproduced 
below, identifies the PM<INF>2.5</INF> and NO<INF>X</INF> emission 
reductions in 2014 and 2017 that the District considers ``surplus'' to 
RFP requirements:

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                               2014                                            2017
                                                         -----------------------------------------------------------------------------------------------
                          Year                              RFP target       Projected                      RFP target       Projected
                                                             emissions       emissions      Contingency      emissions       emissions      Contingency
                                                               level         inventory                         level         inventory
--------------------------------------------------------------------------------------------------------------------------------------------------------
PM2.5...................................................            65.2            63.3             1.9            64.0            62.5             1.5
NOX.....................................................           300.9           284.2            16.7           253.9           235.7            18.2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: 2015 PM2.5 Plan, Chapter 6, Section 6.4, Table 6-10.

    For the 2020 attainment year, the Plan provides estimates of 
emission reductions projected in 2021 from a combination of adopted 
state and local measures, including District Rules 4901, 4306, 4308, 
and 4905 for direct PM<INF>2.5</INF> and NO<INF>X</INF> and mobile 
source measures for several source categories for NO<INF>X</INF>.\513\ 
Table 6-11 of the Plan identifies 1.6 tpd of direct PM<INF>2.5</INF> 
and 12.0 tpd of NO<INF>X</INF> emission reductions as reductions that 
are available to meet the 2020 attainment contingency measure 
requirement. In order to address a shortfall of needed NO<INF>X</INF> 
emission reductions, the District relies on inter-pollutant trading of 
direct PM<INF>2.5</INF> emission reductions for NO<INF>X</INF> emission 
reductions at a ratio of 1:9 and, based on this analysis, concludes 
that there are sufficient emission reductions to meet the attainment 
contingency requirement.\514\ The CARB Staff Report also addresses 
contingency measures for the 2020 attainment year. It identifies 
additional direct PM<INF>2.5</INF> and NO<INF>X</INF> emission 
reductions to be achieved by the following control measures: ARB mobile 
source measures, the Portable Equipment Registration Program (PERP) and 
Airborne Toxic Control Measure (ATCM), Indirect Source Review (ISR) on-
site mitigation (i.e., District Rule 9510), and the AERO \515\ rule 
(i.e., District Rule 4320). Based on these analyses, CARB concludes 
that the SIP control strategy achieves emission reductions sufficient 
to meet the attainment contingency measure requirement for the annual 
PM<INF>2.5</INF> NAAQS.
---------------------------------------------------------------------------

    \513\ 2015 PM<INF>2.5</INF> Plan, Chapter 6, Section 6.4, p. 6-
11, Table 6-11.
    \514\ 2015 PM<INF>2.5</INF> Plan, p. 6-12, Table 6-12.
    \515\ AERO stands for Advanced Emission Reduction Options for 
Boilers, Steam Generators, and Process Heaters Greater Than 5.0 
MMBtu/hr.
---------------------------------------------------------------------------

    Finally, for the 2018 attainment year for the 24-hour 
PM<INF>2.5</INF> NAAQS, the CARB Staff Report states that ``additional 
reductions in 2019 provide 0.2 tpd of PM<INF>2.5</INF> and 10 tpd of 
NO<INF>X</INF> reductions'' but does not identify the control measures 
that achieve these emission reductions.\516\
---------------------------------------------------------------------------

    \516\ 2015 PM<INF>2.5</INF> Plan, CARB Staff Report, p. 27.
---------------------------------------------------------------------------

3. EPA's Evaluation of the 2015 PM<INF>2.5</INF> Plan's Contingency 
Measures
    The contingency measures portion of the 2015 PM<INF>2.5</INF> Plan 
contains several deficiencies.
    First, the Plan incorrectly calculates one year's worth of RFP 
emission

[[Page 6982]]

reductions. Although Chapter 6 of the Plan correctly describes the 
required steps for calculating one year's worth of annual average 
emission reductions needed to demonstrate RFP, the actual calculation 
in the Plan is based on 2020 baseline emission reductions estimates 
\517\ rather than the attainment targets of 60.8 tpd of direct 
PM<INF>2.5</INF> and 206.5 tpd NO<INF>X</INF>.\518\ EPA recalculated 
one year's worth of RFP emission reductions based on the attainment 
emission levels presented in the Plan, as shown in Table 12 below.
---------------------------------------------------------------------------

    \517\ See 2015 PM<INF>2.5</INF> Plan, Chapter 6, Section 6.3, 
Table 6-6, Total Reductions Necessary to Reach Attainment (tpd). The 
``Attainment Emissions Level'' used in Table 6-6 of the Plan reflect 
the projected emission inventory levels found in Appendix B Emission 
Inventory Tables, and does not reflect the attainment target levels 
identified by the CARB Staff Report, section II.B. Attainment 
Emission Levels, Table 1.
    \518\ CARB Staff Report, section II.B. Attainment Emission 
Levels, p. 9.

          Table 12--EPA's Calculation of ``One Year's Worth of RFP'' Using Attainment Emissions Levels
----------------------------------------------------------------------------------------------------------------
                                                                    Calculation of ``One Year's Worth of RFP''
                                                                      Using Attainment Emissions Levels (tpd)
                                                                 -----------------------------------------------
                                                  2012 Base year                                    One year's
                                                     emissions         2020       Total emission   worth of RFP
                                                       (tpd)        Attainment       reduction       emission
                                                                     emissions         (tpd)        reductions
                                                                       (tpd)                           (tpd)
----------------------------------------------------------------------------------------------------------------
Direct PM2.5....................................            66.0            60.8             5.2            0.65
NOX.............................................           332.2           206.5           125.7            15.7
SOX.............................................             8.1             7.8             0.3             0.0
----------------------------------------------------------------------------------------------------------------
Source: 2015 PM2.5 Plan, Chapter 6, Section 6.4, Table 6-6 and CARB Staff Report, p. 9.

    Thus, according to EPA's calculation, one year's worth of RFP is 
0.65 tpd of direct PM<INF>2.5</INF>, 15.7 tpd of NO<INF>X</INF> and 0.0 
tpd of SO<INF>X</INF>. The NO<INF>X</INF> and SO<INF>X</INF> values are 
essentially identical to the values identified in Chapter 6 of the Plan 
(and reproduced in Table 6-9 above), but EPA's calculation of the 
direct PM<INF>2.5</INF> emission reductions representing one year's 
worth of RFP is significantly higher than the value identified in 
Chapter 6 of Plan. Consequently, the Plan significantly underestimates 
the direct PM<INF>2.5</INF> emission reductions necessary to satisfy 
contingency measure requirements.
    Second, the 2015 PM<INF>2.5</INF> Plan does not provide an adequate 
basis for the State's and District's conclusion that the emission 
reductions identified for contingency measure purposes are in fact 
``surplus'' to the reductions needed to demonstrate RFP and timely 
attainment (e.g., for RACM/RACT, BACM/BACT, or MSM). Section 6.4.2 of 
the Plan states that regulatory emission reductions to be achieved by 
2014 and 2017 exceed the minimum emission reductions needed to 
demonstrate RFP in those years but does not provide a basis for the 
District's conclusion that the identified emission reductions are not 
relied on to satisfy RFP requirements. Similarly, the Plan provides no 
support for either the District's conclusion that ``additional 
PM<INF>2.5</INF> and NO<INF>X</INF> reductions occurring between 2020 
and 2021 can serve as attainment contingencies'' or the State's 
conclusion that ``[f]or the interim 24-hour 2018 attainment deadline, 
additional reductions in 2019 provide for 0.2 tpd of PM<INF>2.5</INF> 
and 10 tpd of NO<INF>X</INF> reductions.'' \519\
---------------------------------------------------------------------------

    \519\ 2015 PM<INF>2.5</INF> Plan, Chapter 6, Section 6.4.2 and 
CARB Staff Report, p. 27.
---------------------------------------------------------------------------

    Third, two of the control measures identified in the CARB Staff 
Report as contingency measures--SJVUAPCD Rule 4320 (AERO Rule) and 
SJVUAPCD Rule 9510 (ISR On-Site Mitigation)--are not creditable for SIP 
purposes at this time. Rule 4320 (AERO Rule) is not SIP-creditable 
because it contains provisions that allow owners and operators to pay a 
fee in lieu of complying with the rule's emission limits and which 
render the NO<INF>X</INF> emission limits in the rule 
unenforceable.\520\ Rule 9510 (ISR On-Site Mitigation) is not SIP-
creditable because it likewise contains provisions that allow project 
developers to pay fees instead of implementing on-site pollution 
mitigation plans.\521\
---------------------------------------------------------------------------

    \520\ 75 FR 68294 (November 5, 2010) and 76 FR 16696 (March 25, 
2011).
    \521\ 76 FR 26609 at 26612-26613 (May 9, 2011).
---------------------------------------------------------------------------

    Fourth, the contingency measure portion of the 2015 
PM<INF>2.5</INF> Plan indicates that the District is relying on ``SIP-
creditable incentive-based emissions reductions'' to address 
contingency measure requirements but does not identify the specific 
incentive grant programs expected to provide the requisite emission 
reductions, nor does it provide the documentation and related 
enforceable commitments necessary to support a SIP submission that 
relies on incentive programs for SIP emission reduction credit.\522\ 
Finally, the contingency measure portion of the 2015 PM<INF>2.5</INF> 
Plan does not discuss ammonia emissions or provide any basis for a 
conclusion that contingency measures for purposes of ammonia are not 
necessary to satisfy the statutory requirements.
---------------------------------------------------------------------------

    \522\ The CAA requires that emission reductions resulting from 
incentive programs be ``quantifiable, surplus, enforceable and 
permanent'' in order to qualify for emission reduction credit in a 
SIP. See, e.g., ``Improving Air Quality with Economic Incentive 
Programs,'' U.S. EPA, Office of Air and Radiation, January 2001; see 
also 80 FR 19020 (April 9, 2015) (final action on SJVUAPCD Rule 
9610).
---------------------------------------------------------------------------

    In sum, the 2015 PM<INF>2.5</INF> Plan does not contain or identify 
SIP-creditable measures that are surplus to RFP and attainment needs 
and that are sufficient to achieve at least one year's worth of 
emission reductions for each of the RFP and attainment years identified 
in the Plan. Accordingly, we propose to disapprove the contingency 
measure portion of the 2015 PM<INF>2.5</INF> Plan for failure to 
satisfy the requirements of CAA section 172(c)(9).

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

    Section 189(e) of the Act specifically requires that the control 
requirements applicable to major stationary sources of direct 
PM<INF>2.5</INF> also apply to major stationary sources of 
PM<INF>2.5</INF> precursors, except where the Administrator determines 
that such sources do not contribute significantly to PM<INF>2.5</INF> 
levels that exceed the standards in the area.\523\ The control 
requirements applicable to major stationary sources of direct 
PM<INF>2.5</INF> in a Serious PM<INF>2.5</INF> nonattainment area 
include, at minimum, the requirements of a nonattainment new source 
review (NNSR) permit program meeting the requirements of CAA sections 
172(c)(5)

[[Page 6983]]

and 189(b)(3).\524\ As part of our April 7, 2015 final action to 
reclassify the SJV area as Serious nonattainment for the 1997 
PM<INF>2.5</INF> standards, we established a May 7, 2016 deadline for 
the State to submit NNSR SIP revisions addressing the requirements of 
CAA sections 189(b)(3) and 189(e) of the Act.\525\
---------------------------------------------------------------------------

    \523\ General Preamble at 13539 and 13541-42.
    \524\ CAA section 189(b)(1) (requiring that Serious area plans 
include provisions submitted to meet the requirements for Moderate 
areas in section 189(a)(1)).
    \525\ 80 FR 18528 at 18533 (April 7, 2015).
---------------------------------------------------------------------------

    California has not yet submitted the NNSR SIP revisions required to 
satisfy the subpart 4 requirements for Serious nonattainment areas 
because they are not yet due. Accordingly, we are not proposing any 
action with respect to these requirements at this time. CARB submitted 
amendments to the SJVUAPCD's NNSR rules in 2011 to address the 1997 
PM<INF>2.5</INF> NAAQS to ensure that new and modified major sources of 
PM<INF>2.5</INF> undergo pre-construction review, and the EPA approved 
these NNSR SIP revisions on September 17, 2014.\526\
---------------------------------------------------------------------------

    \526\ 79 FR 55637 (September 17, 2014).
---------------------------------------------------------------------------

I. Motor Vehicle Emission Budgets

1. Requirements for Motor Vehicle Emissions Budgets
    Section 176(c) of the CAA requires federal actions in nonattainment 
and maintenance areas to conform to the SIP's goals of eliminating or 
reducing the severity and number of violations of the NAAQS and 
achieving expeditious attainment of the standards. Conformity to the 
SIP's goals means that such actions will not: (1) Cause or contribute 
to violations of a NAAQS, (2) worsen the severity of an existing 
violation, or (3) delay timely attainment of any NAAQS or any interim 
milestone.
    Actions involving Federal Highway Administration (FHWA) or Federal 
Transit Administration (FTA) funding or approval are subject to the 
EPA's transportation conformity rule, codified at 40 CFR part 93, 
subpart A. Under this rule, metropolitan planning organizations (MPOs) 
in nonattainment and maintenance areas coordinate with state and local 
air quality and transportation agencies, EPA, FHWA, and FTA to 
demonstrate that an area's regional transportation plans (RTP) and 
transportation improvement programs (TIP) conform to the applicable 
SIP. This demonstration is typically done by showing that estimated 
emissions from existing and planned highway and transit systems are 
less than or equal to the motor vehicle emissions budgets (budgets) 
contained in all control strategy SIPs. An attainment, maintenance, or 
RFP SIP should include budgets for the attainment year, each required 
RFP milestone year, or the last year of the maintenance plan, as 
appropriate. Budgets are generally established for specific years and 
specific pollutants or precursors and must reflect all of the motor 
vehicle control measures contained in the attainment and RFP 
demonstrations.\527\
---------------------------------------------------------------------------

    \527\ 40 CFR 93.118(e)(4)(v).
---------------------------------------------------------------------------

    PM<INF>2.5</INF> plans should identify budgets for direct 
PM<INF>2.5</INF>, NO<INF>X</INF> and all other PM<INF>2.5</INF> 
precursors whose on-road emissions are determined to significantly 
contribute to PM<INF>2.5</INF> levels in the area for each RFP 
milestone year and the attainment year, if the plan demonstrates 
attainment. All direct PM<INF>2.5</INF> SIP budgets should include 
direct PM<INF>2.5</INF> motor vehicle emissions from tailpipes, brake 
wear, and tire wear. A state must also consider whether re-entrained 
paved and unpaved road dust or highway and transit construction dust 
are significant contributors and should be included in the direct 
PM<INF>2.5</INF> budget.\528\
---------------------------------------------------------------------------

    \528\ 40 CFR 93.102(b) and 93.122(f); see also 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 
PM<INF>2.5</INF> precursor pollutant.
    In general, only budgets in approved SIPs can be used for 
transportation conformity purposes. However, section 93.118(e) of the 
transportation conformity rule allows budgets in a SIP submission to 
apply for conformity purposes before the SIP submission is approved 
under certain circumstances. First, there must not be any other 
approved SIP budgets that have been established for the same time 
frame, pollutant, and CAA requirement. Second, the EPA must find that 
the submitted SIP budgets are adequate for transportation conformity 
purposes. To be found adequate, the submission must meet the conformity 
adequacy requirements of 40 CFR 93.118(e)(4) and (5). The 
transportation conformity rule does, however, allow for replacement of 
previously approved budgets by submitted motor vehicle emissions 
budgets that the EPA has found adequate, if the EPA has limited the 
duration of its prior approval to the period before it finds 
replacement budgets adequate.\529\
---------------------------------------------------------------------------

    \529\ 40 CFR 93.118(e)(1).
---------------------------------------------------------------------------

2. Motor Vehicle Emissions Budgets in the 2015 PM<INF>2.5</INF> Plan
    The 2015 PM<INF>2.5</INF> Plan includes budgets for direct 
PM<INF>2.5</INF> and NO<INF>X</INF> for 2014 and 2017 (RFP milestone 
years), 2018 (projected attainment year for the 1997 24-hour NAAQS), 
and 2020 (projected attainment year for the 1997 annual NAAQS).\530\ 
The budgets were calculated using EMFAC2014, CARB's latest version of 
the EMFAC model for estimating emissions from on-road vehicles 
operating in California.\531\ The SJV has eight separate county-based 
MPOs; therefore, separate budgets are provided for each MPO as well as 
a total for the nonattainment area as a whole. The budgets for 2014, 
2017, and 2020 reflect annual daily average emissions, and the budgets 
for 2018 reflect winter daily average emissions. Winter average day 
emissions are used for the 2018 budgets because SJV's exceedances of 
the PM<INF>2.5</INF> 24-hour NAAQS occur almost exclusively during the 
winter months and are linked with the District's 2018 attainment 
demonstration for the 24-hour PM<INF>2.5</INF> NAAQS. Annual average 
day emissions are used for the 2014 and 2017 budgets because the 
District has determined that annual average day budgets are the more 
protective of the two budgets options (i.e., annual versus 24-hour 
NAAQS) for the RFP milestone years when both standards apply, as is the 
case for the 2015 PM<INF>2.5</INF> Plan. Annual average day emissions 
are used for the 2020 budgets because those emissions are linked with 
the District's attainment demonstration for the annual PM<INF>2.5</INF> 
NAAQS.
---------------------------------------------------------------------------

    \530\ 2015 PM<INF>2.5</INF> Plan, Chapter 6, Section 6.5.4 (for 
2014, 2017, and 2020 budgets) and 2018 Transportation Conformity 
Budgets for the San Joaquin Valley PM2.5 SIP Plan Supplement,'' 
dated June 19, 2015, and adopted by ARB Board on July 23, 2015, p. 
4.
    \531\ EMFAC is short for EMission FACtor. EPA announced the 
availability of the EMFAC2014 model for use in state implementation 
plan development and transportation conformity in California on 
December 14, 2015. EPA's approval of the EMFAC2014 emissions model 
for SIP and conformity purposes was effective on the date of 
publication of the notice in the Federal Register. EMFAC2014 must be 
used for all new regional emissions analyses and CO, PM<INF>10</INF> 
and PM<INF>2.5</INF> hot-spot analyses that are started on or after 
December 14, 2017, which is the end of the grace period for 
EMFAC2014.
---------------------------------------------------------------------------

    The direct PM<INF>2.5</INF> 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 PM<INF>2.5</INF> levels in 
the SJV.\532\ The Plan does not include budgets for SO<INF>2,</INF> 
VOC, and ammonia. Under 40 CFR 93.102(b)(2)(v), the State

[[Page 6984]]

is not required to include budgets for VOC, sulfur dioxide 
(SO<INF>2</INF>) and/or ammonia (NH3) unless EPA or the State has made 
a finding that transportation-related emissions of any of these 
precursors within the nonattainment area are a significant contributor 
to the PM<INF>2.5</INF> nonattainment problem. The District considered 
on-road SO<INF>2,</INF> VOC, and ammonia emissions and concluded that 
it is not necessary to control on-road SO<INF>2,</INF> VOC, and ammonia 
emissions to attain the NAAQS. The District states in the Plan that on-
road mobile exhaust estimates of SO<INF>X</INF> are less than 1 ton per 
day Valley-wide in the budget years; VOC emissions do not contribute 
significantly to the formation of secondary PM<INF>2.5</INF> in the 
SJV; and on-road mobile exhaust estimates of ammonia are less than 1 
ton per day Valley-wide in the budget years.\533\
---------------------------------------------------------------------------

    \532\ Plan at Chapter 6, Section 6.5.3.
    \533\ Id.

                                           Table 13--MVEBs for the San Joaquin Valley for 1997 PM2.5 Standard
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            2014                      2017                      2018                      2020
                                                 -------------------------------------------------------------------------------------------------------
                     County                         Annual average,  tpd      Annual average,  tpd      Winter average,  tpd      Annual average,  tpd
                                                 -------------------------------------------------------------------------------------------------------
                                                     PM2.5         NOX         PM2.5         NOX         PM2.5         NOX         PM2.5         NOX
--------------------------------------------------------------------------------------------------------------------------------------------------------
Fresno..........................................          1.2         41.2          1.0         31.2          0.9         29.9          0.9         25.3
Kern (SJV)......................................          1.0         36.5          0.8         28.0          0.8         27.7          0.8         23.3
Kings...........................................          0.2          7.6          0.2          5.7          0.1          5.5          0.1          4.8
Madera..........................................          0.2          7.8          0.2          5.8          0.2          5.5          0.2          4.7
Merced..........................................          0.4         13.9          0.3         10.7          0.3         10.3          0.3          8.9
San Joaquin.....................................          0.7         19.6          0.6         14.9          0.6         14.4          0.6         11.9
Stanislaus......................................          0.5         15.6          0.4         11.9          0.4         11.4          0.4          9.6
Tulare..........................................          0.5         14.9          0.4         11.9          0.4         10.3          0.4          9.6
Totals \a\......................................          4.8        157.0          3.8        119.0          3.6        115.0          3.5         96.8
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sources: 2015 PM2.5 Plan, Chapter 6, p. 6-16; and Transportation Conformity Budgets for the San Joaquin Valley PM2.5 SIP, Plan Supplement, dated June
  19, 2015, and adopted by ARB Board on July 23, 2015.
\a\ Totals reflect disaggregated emissions and may not add exactly as shown here due to rounding.

    The 2015 PM<INF>2.5</INF> Plan also includes a proposed trading 
mechanism for transportation conformity analyses that would allow 
future decreases in NO<INF>X</INF> emissions from on-road mobile 
sources to offset any on-road increases in PM<INF>2.5</INF>, using a 
NO<INF>X</INF> to PM<INF>2.5</INF> ratio of 9:1.\534\ The State is 
proposing to use the same 9:1 ratio that was in the 2008 
PM<INF>2.5</INF> Plan and approved by the EPA.\535\
---------------------------------------------------------------------------

    \534\ 2015 PM<INF>2.5</INF> Plan, Chapter 6, p. 6-17.
    \535\ 76 FR 69896 (November 9, 2011).
---------------------------------------------------------------------------

    Using the same Community Multiscale Air Quality modeling 
application \536\ underlying the attainment demonstrations in the prior 
SJV 2008 PM<INF>2.5</INF> Plan and the current 2015 PM<INF>2.5</INF> 
Plan, CARB previously developed an equivalency ratio between emission 
reductions of direct PM<INF>2.5</INF> and of NO<INF>X</INF>. For each 
pollutant, CARB modeled the ambient effect of a 10% reduction of 
emissions over the modeling domain. The concentration change per 
emission change gave a precursor effectiveness value for NO<INF>X</INF> 
and an effectiveness value for direct PM<INF>2.5</INF>. The ratio of 
these two effectiveness values provided the 
NO<INF>X</INF>:PM<INF>2.5</INF> trading ratio.
---------------------------------------------------------------------------

    \536\ The EPA approved this air quality modeling as part of its 
approval of the attainment demonstration in the SJV PM<INF>2.5</INF> 
Plan. See 76 FR 41338, 41349 and 76 FR 69896, 69924.
---------------------------------------------------------------------------

    To ensure that the trading mechanism does not affect the ability of 
the SJV to meet the NO<INF>X</INF> budget, the NO<INF>X</INF> emission 
reductions available to supplement the PM<INF>2.5</INF> budget would 
only be those remaining after the NO<INF>X</INF> budget has been met. 
Each MPO responsible for demonstrating transportation conformity must 
clearly document the calculations used in the trading, along with any 
additional reductions of NO<INF>X</INF> or PM<INF>2.5</INF> emissions 
in the conformity analysis.
3. Evaluation and Proposed Actions
    We have evaluated the budgets against our adequacy criteria in 40 
CFR 93.118(e)(4) and (5) as part of our review of the budgets' 
approvability (see section V in the EPA's General TSD for this 
proposal) and will complete the adequacy review of these budgets 
concurrent with our final action on the 2015 PM<INF>2.5</INF> 
Plan.\537\ On September 18, 2015, the EPA announced the availability of 
the 2015 PM<INF>2.5</INF> Plan with MVEBs and a 30-day public comment 
period. This announcement was posted on EPA's Adequacy Web site at: 
http://www.epa.gov/otaq/stateresources/transconf/reg9sips.htm#ca. The 
comment period for this notification ended on October 19, 2015.
---------------------------------------------------------------------------

    \537\ Under the Transportation Conformity regulations, the EPA 
may review the adequacy of submitted motor vehicle emission budgets 
simultaneously with the EPA's approval or disapproval of the 
submitted implementation plan. 40 CFR 93.118(f)(2).
---------------------------------------------------------------------------

    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 PM<INF>2.5</INF> nonattainment problem in the 
Valley and that these emissions therefore do not need to be addressed 
in the MVEBs (see discussion in section V.A.2 of this proposed rule). 
Additionally, based on the information about VOC, SO<INF>2,</INF> and 
ammonia emissions in the Plan and in accordance with 40 CFR 
93.102(b)(2)(v), we propose to find that it is not necessary to 
establish motor vehicle emissions budgets for transportation-related 
emissions of VOC, SO<INF>2</INF>, and ammonia to attain the 1997 
PM<INF>2.5</INF> standards in the SJV.
    For the reasons discussed in section V.E.2 of this proposed rule, 
we are proposing to approve the State's demonstration that it is 
impracticable to attain the 1997 PM<INF>2.5</INF> NAAQS in the SJV by 
the applicable Serious area attainment date of December 15, 2015 and 
proposing to extend the attainment dates to December 31, 2018 and 
December 31, 2020 for the 24-hour and annual NAAQS, respectively.
    For the reasons discussed in sections V.E.v and V.F of this 
proposed rule, we are proposing to approve the RFP and attainment 
demonstrations in the 2015 PM<INF>2.5</INF> Plan. The budgets, as given 
in

[[Page 6985]]

Table 13 of this proposed rule, are consistent with these 
demonstrations, are clearly identified and precisely quantified, and 
meet all other applicable statutory and regulatory requirements 
including the adequacy criteria in 93.118(e)(4) and (5). For these 
reasons, the EPA proposes to approve the budgets listed in Table 13 
above. We provide a more detailed discussion in section V of the EPA's 
General TSD, which can be found in the docket for today's action.
    CARB has requested that we limit the duration our approval of the 
budgets only until the effective date of the EPA's adequacy finding for 
any subsequently submitted budgets.\538\ The transportation conformity 
rule allows us to limit the approval of budgets.\539\ However, we will 
consider a state's request to limit an approval of its MVEB only if the 
request includes the following elements: \540\
---------------------------------------------------------------------------

    \538\ Letter, Richard W. Corey, Executive Officer, California 
Air Resources Board, to Jared Blumenfeld, Regional Administrator, 
EPA Region 9, June 25, 2015.
    \539\ 40 CFR 93.118(e)(1).
    \540\ 67 FR 69141 (November 15, 2002), limiting our prior 
approval of MVEB in certain California SIPs.
---------------------------------------------------------------------------

    <bullet> An acknowledgement and explanation as to why the budgets 
under consideration have become outdated or deficient;
    <bullet> A commitment to update the budgets as part of a 
comprehensive SIP update; and
    <bullet> A request that the EPA limit the duration of its approval 
to the time when new budgets have been found to be adequate for 
transportation conformity purposes.
    Because CARB's request does not include all of these elements, we 
cannot at this time propose to limit the duration of our approval of 
the submitted budgets until new budgets have been found adequate. In 
order to limit the approval, we would need the information described 
above in order to determine whether such limitation is reasonable and 
appropriate in this case. Once CARB has adequately addressed that 
information, we intend to review it and take appropriate action. If we 
propose to limit the duration of our approval of the MVEB in the 2015 
PM<INF>2.5</INF> 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 PM<INF>2.5</INF> NAAQS.\541\ These budgets will 
continue to apply for the 1997 PM<INF>2.5</INF> NAAQS in the SJV area 
until we finalize our approval of the budgets in the 2015 
PM<INF>2.5</INF> Plan or find them adequate.
---------------------------------------------------------------------------

    \541\ 76 FR 69896, 69923 (November 9, 2011).
---------------------------------------------------------------------------

    As noted above, the State included a trading mechanism to be used 
in transportation conformity analyses that would use the proposed 
budgets in the 2015 PM<INF>2.5</INF> Plan as allowed for under 40 CFR 
93.124. This trading mechanism would allow future decreases in 
NO<INF>X</INF> emissions from on-road mobile sources to offset any on-
road increases in PM<INF>2.5</INF>, using a NO<INF>X</INF> for 
PM<INF>2.5</INF> ratio of 9:1. To ensure that the trading mechanism 
does not affect the ability to meet the NO<INF>X</INF> budget, the Plan 
provides that the NO<INF>X</INF> emission reductions available to 
supplement the PM<INF>2.5</INF> budget would only be those remaining 
after the NO<INF>X</INF> budget has been met. The Plan also provides 
that each MPO responsible for demonstrating transportation conformity 
shall clearly document the calculations used in the trading, along with 
any additional reductions of NO<INF>X</INF> or PM<INF>2.5</INF> 
emissions in the conformity analysis.
    The EPA has reviewed the trading mechanism as described on page 6-
17 in section 6.5.5 of Chapter 6 the 2015 PM<INF>2.5</INF> Plan and 
finds it is appropriate for transportation conformity purposes in the 
San Joaquin Valley for the 1997 PM<INF>2.5</INF> NAAQS. We note that 
the 9:1 NO<INF>X</INF> for PM<INF>2.5</INF> ratio the State is 
proposing to use for transportation conformity purposes in the 2015 
Plan is the same as previously approved by EPA in its action on the SJV 
2008 PM<INF>2.5</INF> Plan.\542\ We therefore propose to approve the 
trading mechanism with a NO<INF>X</INF> for PM<INF>2.5</INF> trading 
ratio of 9:1 as enforceable components of the transportation conformity 
program for the SJV for the 1997 PM<INF>2.5</INF> NAAQS. For further 
discussion of our evaluation of the 9:1 NO<INF>X</INF> for 
PM<INF>2.5</INF> trading ratio for purposes of the Plan's motor vehicle 
emission budgets, please see section IV.B of the EPA's Interpollutant 
Trading Ratios TSD.
---------------------------------------------------------------------------

    \542\ 76 FR 69896 (November 9, 2011).
---------------------------------------------------------------------------

VI. Summary of Proposed Actions and Request for Public Comment

    Under CAA sections 110(k)(3) and 110(k)(4), the EPA is proposing to 
approve, conditionally approve, and disapprove SIP revisions submitted 
by California to address the Act's Serious area planning requirements 
for the 1997 PM<INF>2.5</INF> NAAQS in the San Joaquin Valley 
nonattainment area. Specifically, the EPA is proposing to approve the 
following elements of the 2015 PM<INF>2.5</INF> Plan:
    1. The 2012 base year emissions inventories as meeting the 
requirements of CAA section 172(c)(3);
    2. the best available control measures/best available control 
technology demonstration as meeting the requirements for RACM/RACT and 
BACM/BACT in CAA sections 172(c)(1), 189(a)(1)(C), and 189(b)(1)(B);
    3. the attainment demonstration as meeting the requirements of CAA 
sections 172(c)(1) and 189(b)(1)(A);
    4. the reasonable further progress demonstration as meeting the 
requirements of CAA section 172(c)(2);
    5. the State's application for an extension of the Serious area 
attainment date to December 31, 2018 for the 1997 24-hour 
PM<INF>2.5</INF> NAAQS and to December 31, 2020 for the 1997 annual 
PM<INF>2.5</INF> NAAQS, as meeting the requirements of CAA section 
188(e);
    6. the District's commitment to amend and implement revisions to 
Rule 4692 (``Commercial Charbroiling'') for under-fired charbroilers in 
accordance with the schedule provided on page 7-6 of the 2015 
PM<INF>2.5</INF> Plan to achieve the emissions reductions identified 
therein, as adopted in SJVUAPCD Governing Board Resolution 15-4-7A; and
    7. the 2014, 2017, 2018, and 2020 motor vehicle emissions budgets, 
as shown in Table 13 of this proposed rule, because they are derived 
from approvable attainment and RFP demonstrations and meet the 
requirements of CAA section 176(c) and 40 CFR part 93, subpart A.
    EPA is also proposing to approve the interpollutant trading 
mechanism provided in the 2015 PM<INF>2.5</INF> Plan for use in 
transportation conformity analyses, in accordance with 40 CFR 93.124, 
with the condition that trades are limited to substituting excess 
reductions in NO<INF>X</INF> emissions for direct PM<INF>2.5</INF> 
emission reductions.
    Under CAA section 110(k)(4), the EPA is proposing to conditionally 
approve the quantitative milestones identified in the 2015 
PM<INF>2.5</INF> Plan because they do not fully satisfy the requirement 
for quantitative milestones in section 189(c) of the Act. Section 
110(k)(4) authorizes the EPA to conditionally approve a plan revision 
based on a commitment by the State to adopt specific enforceable 
measures by a date certain but not later than one year after the date 
of the plan approval. In this instance, the enforceable measures that 
the State must submit are enforceable quantitative milestones that 
enable the EPA to determine whether the area is meeting its reasonable 
further progress goals as contemplated in the attainment plan and, if 
the area is not doing so, that enable the EPA to require the State to

[[Page 6986]]

submit plan revisions to correct the deficiency. On December 15, 2015, 
CARB submitted a letter committing to submit a SIP revision containing 
specific quantitative milestones no later than December 31, 2016. If we 
finalize this proposed conditional approval, CARB must adopt and submit 
the SIP revisions it has committed to submit by December 31, 2016. If 
CARB fails to comply with this commitment, this conditional approval 
will convert to a disapproval and start an 18-month clock for sanctions 
under CAA section 179(a)(2) and a two-year clock for a federal 
implementation plan (FIP) under CAA section 110(c)(1).
    Finally, under CAA section 110(k)(3), the EPA is proposing to 
disapprove the contingency measure portion of the 2015 PM<INF>2.5</INF> 
Plan because it does not fully satisfy the requirement for contingency 
measures in section 172(c)(9) of the Act. If we finalize the proposed 
disapproval, the offset sanction in CAA section 179(b)(2) would apply 
in the SJV PM<INF>2.5</INF> nonattainment area 18 months after the 
effective date of final disapproval and the highway funding sanctions 
in CAA section 179(b)(1) would apply in the area 6 months after the 
offset sanction is imposed. Neither sanction would apply if California 
submits and the EPA approves, prior to the implementation of the 
sanctions, SIP revisions that correct the deficiencies identified in 
the EPA's final action. Additionally, the disapproval action would 
trigger an obligation on the EPA to promulgate a federal implementation 
plan unless California corrects the deficiencies, and the EPA approves 
the related plan revisions, within two years of the final action.
    We will accept comments from the public on these proposals for the 
next 30 days. The deadline and instructions for submission of comments 
are provided in the ``Date'' and ``Addresses'' sections at the 
beginning of this preamble.

VII. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive Orders 
can be found at http://www2.epa.gov/laws-regulations/laws-and-executive-orders.

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

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

B. Paperwork Reduction Act (PRA)

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

C. Regulatory Flexibility Act (RFA)

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

D. Unfunded Mandates Reform Act (UMRA)

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

E. Executive Order 13132: Federalism

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

F. Executive Order 13175: Coordination With Indian Tribal Governments

    This action does not have tribal implications, as specified in 
Executive Order 13175, because the SIP is not approved to apply on any 
Indian reservation land or in any other area where the EPA or an Indian 
tribe has demonstrated that a tribe has jurisdiction, and will not 
impose substantial direct costs on tribal governments or preempt tribal 
law. Thus, Executive Order 13175 does not apply to this action.

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

    The EPA interprets Executive Order 13045 as applying only to those 
regulatory actions that concern environmental health or safety risks 
that the EPA has reason to believe may disproportionately affect 
children, per the definition of ``covered regulatory action'' in 
section 2-202 of the Executive Order. This action is not subject to 
Executive Order 13045 because it does not impose additional 
requirements beyond those imposed by state law.

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

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

I. National Technology Transfer and Advancement Act (NTTAA)

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

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Population

    The EPA lacks the discretionary authority to address environmental 
justice in this rulemaking.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Ammonia, 
Incorporation by reference, Intergovernmental relations, Nitrogen 
dioxide, Particulate matter, Reporting and recordkeeping requirements, 
Sulfur dioxide, Volatile organic compounds.

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

    Dated: January 28, 2016.
Jared Blumenfeld,
Regional Administrator, Region 9.
[FR Doc. 2016-02325 Filed 2-8-16; 8:45 am]
 BILLING CODE 6560-50-P


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