[Federal Register Volume 76, Number 135 (Thursday, July 14, 2011)]
[Proposed Rules]
[Pages 41562-41584]
[FR Doc No: 2011-17229]

Vol. 76

Thursday,

No. 135

July 14, 2011

Part II

Environmental Protection Agency

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40 CFR Part 52

Approval and Promulgation of Implementation Plans; California; 2007
South Coast PM2.5 Plan and 2007 State Strategy; Proposed Rules

Federal Register / Vol. 76 , No. 135 / Thursday, July 14, 2011 /
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R09-OAR-2009-0366; FRL-9435-1]

Approval and Promulgation of Implementation Plans; California;
2007 South Coast PM2.5 Plan and 2007 State Strategy

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to approve in part and disapprove in part
state implementation plan (SIP) revisions submitted by California to
provide for attainment of the 1997 fine particulate matter
(PM2.5) national ambient air quality standards in the Los
Angeles-South Coast area (South Coast). These SIP revisions are the
South Coast 2007 Air Quality Management Plan (South Coast 2007 AQMP)
(revised 2011) and South Coast-related provisions of the 2007 State
Strategy (revised 2009 and 2011). EPA is proposing to approve the
emissions inventories; air quality modeling; reasonably available
control measures/reasonably available control technology demonstration;
the reasonable further progress and attainment demonstrations; and the
transportation conformity motor vehicle emissions budgets. EPA is also
proposing to grant California's request to extend the attainment
deadline for the South Coast to April 5, 2015 and to approve
commitments to measures and reductions by the South Coast Air Quality
Management District and the California Air Resources Board. Finally, we
are proposing to disapprove the SIP's contingency measures and to
reject the assignment of 10 tpd of NOX reductions to the
federal government. This proposed rule amends EPA's November 22, 2010
proposed rule (75 FR 91294) on the South Coast PM2.5 plan
and 2007 State strategy.

DATES: Any comments must arrive by August 15, 2011.

ADDRESSES: Submit comments, identified by docket number EPA-R09-OAR-
2009-0366, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov.
Follow the online instructions.
     E-mail<EMAIL_ADDRESS>     Mail or deliver: Marty Robin, Office of Air Planning (AIR-
2), U.S. Environmental Protection Agency Region 9, 75 Hawthorne Street,
San Francisco, CA 94105.
    Instructions: All comments will be included in the public docket
without change and may be made available online at http://www.regulations.gov, including any personal information provided,
unless the comment includes Confidential Business Information (CBI) or
other information whose disclosure is restricted by statute.
Information that you consider CBI or otherwise protected should be
clearly identified as such and should not be submitted through http://www.regulations.gov or e-mail. The http://www.regulations.gov Web site
is an ``anonymous access'' system, and EPA will not know your identity
or contact information unless you provide it in the body of your
comment. If you send e-mail directly to EPA, your e-mail address will
be automatically captured and included as part of the public comment.
If EPA cannot read your comments due to technical difficulties and
cannot contact you for clarification, EPA may not be able to consider
your comment.
    Docket: The index to the docket for this action is available
electronically on the http://www.regulations.gov Web site and in hard
copy at EPA Region 9, 75 Hawthorne Street, San Francisco, California,
94105. While all documents in the docket are listed in the index, some
information may be publicly available only at the hard copy location
(e.g., copyrighted material), and some may not be publicly available at
either location (e.g., CBI). To inspect the hard copy materials, please
schedule an appointment during normal business hours with the contact
listed in the FOR FURTHER INFORMATION CONTACT section below.
    Copies of the SIP materials are also available for inspection at
the following locations:
     California Air Resources Board, 1001 I Street, Sacramento,
California 95812, and
     South Coast Air Quality Management District, 21865 E.
Copley Drive, Diamond Bar, California 91765.

The SIP materials are also electronically available at: http://aqmd.gov/aqmp/07aqmp/index.html and http://www.arb.ca.gov/planning/sip/sip.htm.

FOR FURTHER INFORMATION CONTACT: Wienke Tax, Air Planning Office (AIR-
2), U.S. Environmental Protection Agency, Region 9,<PHONE_NUMBER>,
<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us'' and
``our'' refer to EPA.

Table of Contents

I. The PM2.5 NAAQS and the South Coast PM2.5
Nonattainment Area
II. California's State Implementation Plan Submittals to Address
PM2.5 Attainment in the South Coast Nonattainment Area
    A. California's SIP Submittals
    1. 2007 South Coast AQMP
    2. CARB 2007 State Strategy
    3. CARB 2009 State Strategy Status Report
    4. Additional 2008 SIP Submittal Related to Motor Vehicle
Emissions Budgets
    5. CARB 2011 Progress Report
    6. Revisions to the 2007 PM2.5 and Ozone State
Implementation Plan for South Coast Air Basin and Coachella Valley
    B. CAA Procedural Requirements for SIP Submittals
III. EPA's 2010 Proposed Action on the South Coast PM2.5
SIP
IV. CAA and Regulatory Requirements for PM2.5 Attainment
SIPs
V. Review of the South Coast 2007 AQMP and the South Coast Portion
of the Revised 2007 State Strategy
    A. Emission Inventories
    1. Requirements for Emission Inventories
    2. Emission Inventories in the South Coast 2007 AQMP
    3. Proposed Action on the Emission Inventories
    B. Reasonably Available Control Measures (RACM)/Reasonably
Available Control Technology (RACT) and Adopted Control Strategy
    1. Requirement for RACM/RACT
    2. RACM/RACT Demonstration in the South Coast 2007 AQMP and the
2007 State Strategy
    a. District's RACM/RACT Analysis and Adopted Control Strategy
    b. CARB's RACM Analysis and Adopted Control Strategy
    c. The Local Jurisdiction's RACM Analysis
    3. Proposed Actions on RACM/RACT Demonstration and Adopted
Control Strategy
    C. Attainment Demonstration
    1. Requirements for Attainment Demonstration
    2. Air Quality Modeling in the South Coast 2007 AQMP
    3. PM2.5 Precursors Addressed in the South Coast 2007
AQMP
    4. Extension of the Attainment Date
    5. Attainment Demonstration
    a. Enforceable Commitments
    i. The Commitment Represents a Limited Portion of Required
Reductions
    ii. The State Is Capable of Fulfilling Its Commitment
    iii. The Commitment Is for a Reasonable and Appropriate Period
of Time
    b. Federal Reductions
    6. Proposed Action on the Attainment Demonstration
    D. Reasonable Further Progress Demonstration
    1. Requirements for Reasonable Further Progress
    2. Reasonable Further Progress Demonstration in the South Coast
2007 AQMP
    3. Proposed Action on the RFP Demonstration
    E. Contingency Measures
    1. Requirements for Contingency Measures
    2. Contingency Measures in the South Coast 2007 AQMP
    3. Proposed Action on the Contingency Measures
    F. Motor Vehicle Emissions Budgets for Transportation Conformity

    1. Requirements for Transportation Conformity
    2. Budgets in the South Coast 2007 AQMP and Additional 2008
Submittal
    3. EPA's 2008 Adequacy/Inadequacy Finding
    4. Updated Motor Vehicle Emissions Budgets in the 2011 Progress
Report and Additional Revisions
    5. Proposed Action on the Revised Updated Budgets in the 2011
Progress Report
    6. Proposed Action on the Trading Mechanism
VI. EPA's Proposed Actions and Consequences
    A. EPA's Proposed Approvals and Disapprovals
    B. CAA Consequences of a Final Disapproval
VII. Statutory and Executive Order Reviews

I. The PM2.5 NAAQS and the South Coast PM2.5
Nonattainment Area

    On July 18, 1997 (62 FR 36852), EPA established new national
ambient air quality standards (NAAQS) for PM2.5, particulate
matter with a diameter of 2.5 microns or less, including annual
standards of 15.0 micrograms per cubic meter ([mu]g/m\3\) based on a 3-
year average of annual mean PM2.5 concentrations, and 24-
hour (daily) standards of 65 [mu]g/m\3\ based on a 3-year average of
the 98th percentile of 24-hour concentrations. 40 CFR 50.7 EPA
established the standards based on substantial evidence from numerous
health studies demonstrating that serious health effects are associated
with exposures to PM2.5 concentrations above the levels of
these standards.
    Epidemiological studies have shown statistically significant
correlations between elevated PM2.5 levels and premature
mortality. Other important health effects associated with
PM2.5 exposure include aggravation of respiratory and
cardiovascular disease (as indicated by increased hospital admissions,
emergency room visits, absences from school or work, and restricted
activity days), changes in lung function and increased respiratory
symptoms, as well as new evidence for more subtle indicators of
cardiovascular health. Individuals particularly sensitive to
PM2.5 exposure include older adults, people with heart and
lung disease, and children. See, EPA, Air Quality Criteria for
Particulate Matter, No. EPA/600/P-99/002aF and EPA/600/P-99/002bF,
October 2004.
    PM2.5 can be emitted directly into the atmosphere as a
solid or liquid particle (``primary'' or ``direct PM2.5'')
or can be formed in the atmosphere as a result of various chemical
reactions from precursor emissions of nitrogen oxides (NOX),
sulfur oxides (SOX), volatile organic compounds (VOC) and
ammonia (NH3) (``secondary PM2.5''). See 72 FR
20586, 20589 (April 25, 2007).
    Following promulgation of a new or revised NAAQS, EPA is required
by Clean Air Act (CAA) section 107(d) to designate areas throughout the
United States as attaining or not attaining the NAAQS. On January 5,
2005, EPA published initial air quality designations for the 1997
PM2.5 NAAQS, based on air quality monitoring data for three-
year periods of 2001-2003 or 2002-2004 (70 FR 944). These designations
became effective on April 5, 2005.
    EPA designated the ``Los Angeles-South Coast Air Basin'' area
(South Coast nonattainment area), including Orange County, the
southwestern two-thirds of Los Angeles County, southwestern San
Bernardino County, and western Riverside County as nonattainment for
both the 1997 24-hour and the annual PM2.5 standards. The
South Coast PM2.5 nonattainment area is home to about 17
million people, has a diverse economic base, and contains one of the
highest-volume port areas in the world. For a precise description of
the geographic boundaries of the South Coast PM2.5
nonattainment area, see 40 CFR 81.305.\1\ The local air district with
primary responsibility for developing a plan to attain the
PM2.5 NAAQS in this area is the South Coast Air Quality
Management District (District or SCAQMD).
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    \1\ On October 17, 2006, EPA strengthened the 24-hour
PM2.5 NAAQS by lowering the level to 35 [mu]g/m\3\. At
the same time, we retained the level of the annual PM2.5
standard at 15.0 [mu]g/m\3\. 71 FR 61144. On November 13, 2009, EPA
designated areas, including the South Coast, with respect to the
revised 24-hour NAAQS. 74 FR 58688. California is now required to
submit an attainment plan for the 35 [mu]g/m\3\ standards by
December 14, 2012. In this preamble, all references to the
PM2.5 NAAQS, unless otherwise specified, are to the 1997
24-hour PM2.5 standards of 65 [mu]g/m\3\ and annual
standards of 15 [mu]g/m\3\ as codified in 40 CFR 50.7.
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    Ambient 24-hour PM2.5 levels in the South Coast are well
below the 1997 PM2.5 NAAQS. Ambient annual PM2.5
levels are improving but are still above the federal NAAQS. The design
value monitor at Mira Loma recorded a value of 16.8 [mu]g/m\3\ for the
2008-2010 period.\2\ In the South Coast, the levels and composition of
PM2.5 differ by geographic location, with higher
PM2.5 concentrations typically occurring in metropolitan Los
Angeles and in the inland valley areas of San Bernardino and
metropolitan Riverside Counties. The higher PM2.5
concentrations in Los Angeles County are mainly due to secondary
formation of particulates. See South Coast 2007 AQMP, page 2-13.
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    \2\ See the Air Quality Subsystem (AQS) Preliminary Design Value
Report dated April 21, 2011 in the docket for today's action. 16.8
[mu]g/m\3\ is the highest design value in the South Coast
nonattainment area. The design value is the three year average of
annual means of a single monitoring site. (see 40 CFR 50 Appendix N
Section 1(c)(1)). This design value is based on 2008 and 2009 data
that are complete, validated, and certified by the District and on
2010 data that are complete and validated but not yet certified by
the District.
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II. California's State Implementation Plan Submittals To Address
PM2.5 Attainment in the South Coast Nonattainment Area

A. California's SIP Submittals

    Designation of an area as nonattainment starts the process for a
state to develop and submit to EPA a State Implementation plan (SIP)
under title 1, part D of the CAA. This SIP must include, among other
things, a demonstration of how the NAAQS will be attained in the
nonattainment area as expeditiously as practicable, but no later than
the date required by the CAA. Under CAA section 172(b), a State has up
to three years after an area's designation to nonattainment to submit
its SIP to EPA. For the 1997 PM2.5 NAAQS, these
nonattainment SIPs were due no later than April 5, 2008.
    California has made six SIP submittals to address PM2.5
nonattainment in the South Coast nonattainment area. The two principal
ones are the District's 2007 PM2.5 Plan (South Coast 2007
AQMP) and the CARB's State Strategy for California's 2007 State
Implementation Plan (2007 State Strategy).
    In addition to these submittals, the District and State have also
submitted numerous rules that contribute to improving air quality in
the South Coast nonattainment area. See Appendices A and B of the
technical support document (TSD) for this proposal.
1. 2007 South Coast AQMP
    On November 28, 2007, the California Air Resources Board (CARB or
State) submitted the ``Final 2007 Air Quality Management Plan, June
2007.'' \3\ This

Plan was adopted by the District on June 1, 2007 and submitted to CARB
on October 24, 2007.\4\ The South Coast 2007 AQMP includes a
PM2.5 attainment demonstration for the South Coast. In order
to meet relevant CAA requirements for the PM2.5 NAAQS, the
South Coast 2007 AQMP includes base and projected year PM2.5
emissions inventories for the South Coast nonattainment area; air
quality monitoring data; short-, medium- and long-term District control
measures; a summary of CARB's control measures; transportation control
measures (TCMs); a demonstration of reasonable further progress (RFP);
a modeled attainment demonstration; a demonstration of reasonably
available control measures/reasonably available control technology
(RACM/RACT); contingency measures for the 1997 PM2.5 RFP and
for attainment for the South Coast PM2.5 nonattainment area;
and a request to extend the attainment date for the 1997
PM2.5 NAAQS to April 5, 2015, although all controls
necessary for attainment by that date will be in place by the
attainment year of 2014.\5\ The South Coast 2007 AQMP submittal also
includes District Governing Board Resolution 07-9 adopting the final
South Coast 2007 AQMP.
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    \3\ The South Coast 2007 AQMP is the first South Coast Plan to
address PM2.5. We have previously acted on numerous South
Coast air quality plans for ozone, PM-10, carbon monoxide, and
NO2, such as the 1997/1999 AQMP. We approved the ozone
portion of the 1997 South Coast AQMP, as amended in 1999, on April
10, 2000 (see 65 FR 18903). Our most recent action on a SIP
addressing the CAA requirements for the South Coast ozone
nonattainment area was our partial approval and partial disapproval
of the 2003 AQMP (see 74 FR 10176, March 10, 2009). Our 2009 final
action was challenged in the Ninth Circuit Court of Appeals, which
published an opinion remanding certain aspects of EPA's action for
further action consistent with the opinion. See Association of
Irritated Residents v. EPA, 632 F.3d 584 (9th Cir. 2011). The issues
in dispute relate to the consequences of an EPA disapproval of a SIP
submittal, the adequacy of EPA's evaluation of a particular control
measure from the 2003 State Strategy, and the rationale for EPA's
approval of the State's submittal as meeting the requirements of CAA
section 182(d)(1)(A) (TCMs to offset growth in emissions from growth
in VMT) in the South Coast. EPA has sought rehearing on some of the
issues, and the mandate in this case has not yet been issued pending
action by the court on the petition for rehearing.
    \4\ See letter, James N. Goldstene, Executive Officer, CARB, to
Jared Blumenfeld, Regional Administrator, EPA Region 9, September
15, 2010, with enclosures.
    \5\ While the applicable attainment date for PM2.5
areas with a full five-year extension is April 5, 2015, reductions
must be implemented by 2014 to achieve attainment by that date. See
40 CFR 51.1007(b). We, therefore, refer to 2014 as the attainment
year and April 5, 2015 as the attainment date.
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2. CARB 2007 State Strategy
    To demonstrate attainment, the South Coast 2007 AQMP relies in part
on measures in the 2007 State Strategy. The 2007 State Strategy was
adopted on September 27, 2007 and submitted to EPA on November 16,
2007.\6\ It discusses CARB's overall approach to addressing, in
conjunction with local plans, attainment of both the 1997
PM2.5 and 8-hour ozone NAAQS not only in the South Coast
nonattainment area but also in California's other nonattainment areas
such as the San Joaquin Valley and the Sacramento area. It also
includes CARB's commitments to propose 15 defined State measures \7\
and to obtain specific amounts of aggregate emissions reductions of
direct PM2.5, NOX, VOC and SOX in the
South Coast from sources under the State's jurisdiction, primarily on-
and off-road motor vehicles and engines.
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    \6\ See CARB Resolution No. 07-28, September 27, 2007 with
attachments and letter from James N. Goldstene, Executive Officer,
CARB, to Wayne Nastri, Regional Administrator, EPA Region 9,
November 16, 2007 with enclosures.
    \7\ The 2007 State Strategy also includes measures to be
implemented by the California Bureau of Automotive Repair (Smog
Check improvements) and the California Department of Pesticide
Regulation (VOC reductions from pesticide use). See 2007 State
Strategy, p. 64-65 and CARB Resolution 7-28, Attachment B, p. 8.
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3. CARB 2009 State Strategy Status Report
    On August 12, 2009, CARB submitted the ``Status Report on the State
Strategy for California's 2007 State Implementation Plan (SIP) and
Proposed Revision to the SIP Reflecting Implementation of the 2007
State Strategy'', dated March 24, 2009, adopted April 24, 2009 (``2009
State Strategy Status Report''),\8\ which updates the 2007 State
Strategy to reflect its implementation during 2007 and 2008.
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    \8\ See CARB Resolution No. 09-34, April 24, 2009 and letter,
James N. Goldstene, Executive Officer, CARB to Wayne Nastri,
Regional Administrator, EPA Region 9, August 12, 2009 with
enclosures. Only pages 11-27 of the 2009 State Strategy Status
Report are submitted as a SIP revision. The balance of the report is
for informational purposes only. See Attachment A to CARB Resolution
No. 09-34.
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    In today's proposal, we are evaluating only those portions of the
South Coast 2007 AQMP and 2007 State Strategy and its revisions
(including the 2011 revisions described below) that are relevant for
attainment of the 1997 PM2.5 standards in the South Coast
nonattainment area.
4. Additional 2008 SIP Submittal Related to Motor Vehicle Emissions
Budgets
    In addition to the SIP submittals for the 1997 PM2.5
NAAQS mentioned above, on April 4, 2008, the District Governing Board
approved an alternative approach for transportation conformity motor
vehicle emission budgets for the South Coast nonattainment area. This
new approach was based on the 2007 SIP baseline emissions reflecting
only the regulations adopted as of October 2006 for all milestone years
up to the attainment year. The CARB Governing Board approved Resolution
08-27 itemizing the modifications to the South Coast nonattainment area
transportation conformity emission budgets. The revised motor vehicle
emissions budgets were submitted as an amendment to the California SIP
on April 30, 2008 and were amended as part of the 2011 Progress Report
discussed below. We are acting on the budgets as amended in 2011 today.
5. CARB 2011 Progress Report
    On May 18, 2011, CARB submitted the ``Progress Report on
Implementation of PM2.5 State Implementation Plans (SIP) for
the South Coast and San Joaquin Valley Air Basins and Proposed SIP
Revisions'', dated March 29, 2011, and adopted April 28, 2011 (``2011
Progress Report'').\9\ This submittal, which updates both the 2007
State Strategy and the South Coast 2007 AQMP, shows that both CARB and
the District have made significant progress in meeting their
commitments to adopt measures and to reduce emissions. More
specifically, it updates CARB's rulemaking calendar in the 2007 State
Strategy to reflect the current status of CARB's adopted
PM2.5 measures and to change the expected action dates for
several measures. It also updates the RFP demonstration, contingency
measures, and transportation conformity motor vehicle emissions budgets
in the South Coast 2007 AQMP to reflect rule adoption, changes to
activity and emissions factors for certain source categories, and the
impact on projected emissions levels in the South Coast nonattainment
area of the recent economic recession.\10\
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    \9\ See CARB Board Resolution 11-24, May 18, 2011 and letter,
James N. Goldstene, Executive Officer, CARB to Jared Blumenfeld,
Regional Administrator, EPA Region 9, May 19, 2011 with enclosures.
Only Appendices B, C and D of the 2011 Progress Report are submitted
as a SIP revision. The balance of the report is for informational
purposes only.
    \10\ On June 20, 2011, CARB posted to its Web site technical
revisions to the updated motor vehicle emissions budgets (budgets)
in the 2011 Progress Report. See http://www.arb.ca.gov/planning/sip/2007sip/2007sip.htm. We discuss these revisions in the section on
budgets below.
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6. Revisions to the 2007 PM2.5 and Ozone State
Implementation Plan for South Coast Air Basin and Coachella Valley
    Also, on May 19, 2011, CARB submitted a SIP revision entitled
``Revisions to the 2007 PM2.5 and Ozone State Implementation
Plan for South Coast Air Basin and Coachella Valley (SIP Revisions)''.
These SIP revisions provide revised control measure commitments, a
revised rule implementation schedule, and a partial backstop for the 10
tpd NOX federal assignment for the South Coast 2007
AQMP.\11\ For the purposes of today's

proposal, we will refer to this SIP revision as ``2011 Progress Report,
Appendix F'', since it was included as an Appendix to the 2011 Progress
Report submitted on May 18, 2011.
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    \11\ See letter, Lynn Terry, Deputy Executive Officer, CARB, to
Jared Blumenfeld, Regional Administrator, EPA Region 9, dated May
19, 2011, and enclosed ARB Board Resolution 11-24.
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    In today's proposal, we are only evaluating those portions of the
South Coast 2007 AQMP and the 2007 State Strategy and its revisions
that are relevant for attainment of the PM2.5 standards in
the South Coast nonattainment area.
    Future references in this proposal to the AQMP and the 2007 State
Strategy will be to the AQMP as revised in 2011 and the Strategy as
revised in 2009 and 2011, respectively, unless otherwise noted.

B. CAA Procedural Requirements for SIP Submittals

    CAA sections 110(a)(1) and (2) and 110(l) require a state to
provide reasonable public notice and opportunity for public hearing
prior to the adoption and submittal of a SIP or SIP revision. To meet
this requirement, every SIP submittal should include evidence that
adequate public notice was given and an opportunity for a public
hearing was provided consistent with EPA's implementing regulations in
40 CFR 51.102.
    Both the District and CARB have satisfied applicable statutory and
regulatory requirements for reasonable public notice and hearing prior
to adoption and submittal of the South Coast 2007 AQMP. The District
conducted public workshops, provided public comment periods, and held
public hearings prior to the adoption of the South Coast 2007 AQMP on
June 1, 2007 (District Governing Board Resolution No. 07-9). CARB
provided the required public notice and opportunity for public comment
prior to its September 27, 2007 public hearing on the plan. See CARB
Resolution No. 07-41.
    CARB conducted public workshops, provided public comment periods,
and held a public hearing prior to the adoption of the 2007 State
Strategy on September 27, 2007. (CARB Resolution No. 07-28). CARB also
provided the required public notice, opportunity for public comment,
and a public hearing prior to its April 24, 2009 adoption of the 2009
State Strategy Status Report. CARB also provided the required public
notice, opportunity for public comment, and a public hearing prior to
its April 28, 2011 adoption of the 2011 Progress Report. See CARB
Resolution 09-34 and CARB Executive Order S-11-010.
    The SIP submittals include proof of publication for notices of the
District and CARB public hearings, as evidence that all hearings were
properly noticed. We find, therefore, that the four submittals that
comprise the South Coast PM2.5 Plan meet the procedural
requirements of CAA sections 110(a) and 110(l).
    CAA section 110(k)(1)(B) requires EPA to determine whether a SIP
submittal is complete within 60 days of receipt. This section also
provides that any plan that EPA has not affirmatively determined to be
complete or incomplete will become complete 6 months after the date of
submittal by operation of law. EPA's SIP completeness criteria are
found in 40 CFR part 51, Appendix V.
    The South Coast 2007 AQMP became complete by operation of law on
May 28, 2008. The November 16, 2007 submission of the 2007 State
Strategy and the 2009 revisions to the Strategy became complete by
operation of law on May 16, 2008 and February 12, 2010, respectively.
We determined that the 2011 Progress Report was complete on June 13,
2011.\12\
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    \12\ See letter, Deborah Jordan, EPA Region 9, to James
Goldstene, CARB, dated June 13, 2011 in the docket for today's
action.
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III. EPA's 2010 Proposed Action on the South Coast PM2.5 SIP

    This is the second time EPA has proposed action on California's SIP
to address attainment of the 1997 PM2.5 standards in the
South Coast nonattainment area. On November 22, 2010 (75 FR 71294), EPA
proposed to approve in part and disapprove in part the 2007 South Coast
PM2.5 plan and the related portions of the 2007 State
Strategy as amended in 2009.
    Specifically, we proposed to approve the emissions inventories as
meeting the applicable requirements of the CAA and the PM2.5
implementation rule in 40 CFR part 51, subpart Z. We proposed to
approve the District's and CARB's commitments to specific measures and
specific aggregate emissions reductions in these SIP revisions because
their approval would strengthen the SIP. We also proposed to approve
the air quality modeling.
    We previously proposed to disapprove the attainment demonstration
as not meeting the applicable requirements of the CAA and the
PM2.5 implementation rule because it relied too extensively
on enforceable commitments to reduce emissions in place of fully-
adopted and submitted rules. Based on this proposed disapproval, we
also proposed to disapprove the RACM/RACT and RFP demonstrations. We
also proposed to disapprove the related contingency measures and
transportation conformity motor vehicle emissions budgets for the RFP
milestone years 2009 and 2012 and the attainment year of 2014. Finally,
we proposed not to grant the State's request to extend the attainment
date for the PM2.5 NAAQS in the South Coast nonattainment
area to April 5, 2015.
    During the comment period for the November 2010 proposal, we
received four comment letters from the public as well as comment
letters from CARB and the District. Subsequent to the close of the
comment period, CARB adopted and submitted revisions to the South Coast
2007 AQMP and 2007 State Strategy. After considering information
contained in the comment letters and these supplemental SIP submittals,
we have substantially amended our November 2010 proposed action as
described below. EPA will consider all significant comments submitted
in response to both its November 2010 proposal and today's proposal
before taking final action on the South Coast 2007 AQMP. However, EPA
strongly encourages those who submitted comments on the November 2010
proposal to submit revised comments reflecting today's amended proposal
during the comment period on this amended proposal.

IV. CAA and Regulatory Requirements for PM2.5 Attainment
SIPs

    EPA is implementing the PM2.5 NAAQS under Title 1, part
D, subpart 1 of the CAA, which includes section 172, ``Nonattainment
plan provisions.'' Section 172(a)(2) establishes the attainment date
for a PM2.5 nonattainment area ``as expeditiously as
practicable'' but no later than five years after the area's designation
as nonattainment. This section also allows EPA to grant up to a five-
year extension of an area's attainment date based on the severity of
the area's nonattainment and the availability and feasibility of
controls. EPA designated the South Coast as a nonattainment area
effective April 5, 2005, and thus the applicable attainment date is no
later than April 5, 2010 or, should EPA grant a full five-year
extension, no later than April 5, 2015.
    Section 172(c) contains the general statutory planning requirements
applicable to all nonattainment areas, including the requirements for
emissions inventories, RACM/RACT, attainment demonstrations, RFP
demonstrations, and contingency measures.
    On April 25, 2007, EPA issued the Clean Air Fine Particle
Implementation

Rule for the 1997 PM2.5 NAAQS. 72 FR 20586, codified at 40
CFR part 51, subpart Z (PM2.5 implementation rule). The
PM2.5 implementation rule and its preamble address the
statutory planning requirements for emissions inventories, RACM/RACT,
attainment demonstrations including air quality modeling requirements,
RFP demonstrations, and contingency measures. This rule also addresses
other matters such as which PM2.5 precursors must be
addressed by the State in its PM2.5 attainment SIP,
applicable attainment dates, and the requirement for mid-course
reviews.\13\ We will discuss each of these CAA and regulatory
requirements for attainment plans in more detail below.
---------------------------------------------------------------------------

    \13\ In June 2007, a petition to the EPA Administrator was filed
on behalf of several public health and environmental groups
requesting reconsideration of four provisions in the
PM2.5 implementation rule. See EarthJustice, Petition for
Reconsideration, ``In the Matter of Final Clean Air Fine Particle
Implementation Rule,'' June 25, 2007. These provisions are (1) the
presumption that compliance with the Clean Air Interstate Rule
satisfies the NOX and SO2 RACT requirements
for electric generating units; (2) the deferral of the requirement
to establish emission limits for condensable particulate matter
(CPM) until January 1, 2011; (3) revisions to the criteria for
analyzing the economic feasibility of RACT; and (4) the use of out-
of-area emissions reductions to demonstrate RFP. These provisions
are found in the PM2.5 implementation rule and preamble
at 20623-20628, 40 CFR 51.1002(c), 20619-20620, and 20636,
respectively. On May 13, 2010, EPA granted the petition with respect
to the fourth issue. Letter, Gina McCarthy, EPA, to David Baron and
Paul Cort, EarthJustice, May 13, 2010. On April 25, 2011, EPA
granted the petition with respect to the first and third issues, but
denied the petition with respect to the second issue given that the
deferral period for CPM emissions limits had already ended. Letter,
Lisa P. Jackson, EPA, to Paul Cort, EarthJustice, April 25, 2011.
EPA intends to publish in the Federal Register notice that will
announce the granting of the latter petition with respect to certain
issues and to initiate a notice and comment process to consider
proposed changes to the 2007 PM2.5 implementation rule.
    Neither the District nor the State relied on the first, third,
or fourth of these provisions in preparing the South Coast 2007 AQMP
or 2007 State Strategy. The District has deferred CPM limits in its
rules. This limited deferral does not affect the South Coast 2007
AQMP's RACM/RACT and expeditious attainment demonstrations. EPA will
evaluate any rule adopted or revised by the District after January
1, 2011 to assure that it appropriately addresses CPM.
---------------------------------------------------------------------------

V. Review of the South Coast 2007 AQMP and the South Coast Portion of
the 2007 State Strategy

    We summarize our evaluation of the South Coast PM2.5
plan's compliance with applicable CAA and EPA regulatory requirements
below. Our detailed evaluation can be found in the TSD for this
proposal, which is available on line at http://www.regulations.gov in
docket number EPA-R09-OAR-2009-0366, or from the EPA contact listed at
the beginning of this notice.

A. Emissions Inventories

1. Requirements for Emissions Inventories
    CAA section 172(c)(3) requires states to submit a plan revision
that includes ``comprehensive, accurate, current inventory of actual
emissions from all sources of the relevant pollutant.'' The
PM2.5 implementation rule requires states to include direct
PM2.5 emissions and emissions of all PM2.5
precursors in this inventory, even if it has determined that control of
any of these precursors is not necessary for expeditious attainment. 40
CFR 51.1008(a)(2) and 72 FR 20586, at 20648. Direct PM2.5
includes condensable particulate matter. See 40 CFR 51.1000.
PM2.5 precursors are NOX, SO2, VOC,
and ammonia (NH3).\14\ Id. The inventories should meet the
data requirements of EPA's Consolidated Emissions Reporting Rule
(codified at 40 CFR part 51 subpart A) and include any additional
inventory information needed to support the SIP's attainment
demonstration and (where applicable) RFP demonstration. 40 CFR
51.1008(a)(1) and (2).
---------------------------------------------------------------------------

    \14\ The District controls sulfur oxides (SOX), which
includes SO2, and considers the two terms interchangeable
for emissions purposes. We will use SOX in this notice.
---------------------------------------------------------------------------

    Baseline emissions inventories are required for the attainment
demonstration and for meeting RFP requirements. As determined on the
date of designation, the base year for these inventories should be the
most recent calendar year for which a complete inventory was required
to be submitted to EPA. The emission inventory for calendar year 2002
or other suitable year should be used for attainment planning and RFP
plans for areas initially designated nonattainment for the
PM2.5 NAAQS in 2005. 40 CFR 51.1008(b).
    EPA has provided additional guidance for PM2.5 emission
inventories in ``Emissions Inventory Guidance for Implementation of
Ozone and Particulate Matter NAAQS and Regional Haze Regulations,''
November 2005 (EPA-454/R-05-001).
2. Emissions Inventories in the South Coast 2007 AQMP
    The base year and future year baseline planning inventories for
direct PM2.5 and all PM2.5 precursors for the
South Coast nonattainment area together with additional documentation
for the inventories are found in Appendix III of the South Coast 2007
AQMP. Average annual day baseline inventories are provided for the
plan's base year of 2002 (the reference year for the RFP demonstration)
as well as 2005, 2008, 2010, 2011, and 2014. The base year and baseline
inventories incorporate reductions from federal, state, and District
measures adopted prior to 2007. South Coast 2007 AQMP, page 3-1. The
District also provided both summer and winter planning inventories for
PM2.5 and PM2.5 precursors. South Coast 2007
AQMP, Appendix III, page III-1-23.
    Table 1 is a summary of the average annual day inventories for
directly-emitted PM2.5 and for the PM2.5
precursors NOX, VOC, and SOX for the base year of
2002 from the South Coast 2007 AQMP (derived from Appendix A, Table A-
2). It is these inventories that provide the basis for the control
measure analysis and the RFP and attainment demonstrations in the South
Coast 2007 AQMP.

 Table 1--South Coast Nonattainment Area Emissions Inventory Summary for PM2.5 and PM2.5 Precursors for the 2002
                                                  Baseline Year
                               [Annual average day emissions in tons per day] \a\
----------------------------------------------------------------------------------------------------------------
                                                                                NH3 \b\
          Emissions inventory category            NOX  2002    VOC  2002    PM2.5 2002    SOX 2002       2005
----------------------------------------------------------------------------------------------------------------
Stationary/Areawide Sources....................           93          302           60           22           75
On-road Mobile Sources.........................          628          362           18            4           29
Off-road Mobile Sources........................          372          180           21           27          n/a
                                                ----------------------------------------------------------------

    Total......................................         1093          844           99           53          104
----------------------------------------------------------------------------------------------------------------
\a\ Source: 2007 AQMP, pp. 3-9 and 3-14, Tables 3-1A and 3-3A. Numbers may not add due to rounding. Ammonia
  emissions estimates were updated to 2005 by SCAQMD.
\b\ NH3 numbers were not provided for 2002.

    As a starting point for the South Coast 2007 AQMP's inventories,
the District used CARB's inventory for the year 2002. An example of
this inventory and CARB's documentation for its inventories can be
found in Appendices A and F, respectively, of the 2007 State Strategy.
The 2002 inventory for the South Coast nonattainment area was projected
to future years using CARB's California Emission Forecasting and
Planning Inventory System (CEFIS). South Coast 2007 AQMP, Appendix III,
page III-1-1. Both base year and baseline inventories use the current
version of California's mobile source emissions model approved by EPA
for use in SIPs, EMFAC2007, for estimating on-road motor vehicle
emissions. 73 FR 3464 (January 18, 2008). Off-road inventories were
developed using the CARB off-road model. Ammonia emissions estimates
were provided separately by the District.\15\
---------------------------------------------------------------------------

    \15\ Electronic mail from Kathy Hsiao, SCAQMD to Wienke Tax, EPA
Region 9, ``RE: NH3 numbers for SCAB,'' dated October 29, 2010.
---------------------------------------------------------------------------

    When CARB submitted the 2011 Progress Report, the revised
attainment demonstration for the South Coast was based on the 2002
baseline inventory. This is consistent with the baseline inventory in
the 2007 AQMP, as well as the base year for the RFP demonstration. It
is also the year recommended by EPA guidance.\16\
---------------------------------------------------------------------------

    \16\ See 72 FR 20586, at 20647.
---------------------------------------------------------------------------

3. Proposed Action on the Emission Inventories
    The inventories in the South Coast 2007 AQMP are based on the most
current and accurate information available to the State and District at
the time the Plan was developed and submitted (including using the
latest EPA-approved version of California's mobile source emissions
model, EMFAC2007), address comprehensively all source categories in the
South Coast nonattainment area, and are consistent with EPA's inventory
guidance. For these reasons, EPA is proposing to approve the 2002 base
year emissions inventory in the South Coast 2007 AQMP as meeting the
requirements of CAA section 172(c)(3) and 40 CFR 51.1008(a)(1) and to
find that the baseline inventories in the South Coast 2007 AQMP provide
an adequate basis for the RACM/RACT, RFP, and attainment
demonstrations. We provide more detail on our review of the base year
inventory as well as the projected year inventories in section II.A. of
the TSD.
    Since late 2007, California has experienced an economic recession
that has greatly reduced current levels of economic activity in the
State's construction and goods movement sectors. The recession has
resulted in lowered projected future levels of activity in this sector.
2011 Progress Report, Appendix E. As a result, projected emission
levels from these categories are now substantially lower than the
levels projected for 2008 and later in the Plan as submitted in 2007.
At this time, California is addressing these recession impacts on
future economic activity through adjustments to the baseline
inventories for specific source categories. See 2011 Progress Report,
Appendix E, page 2. There are no recession-related adjustments to the
2002 base year inventory in the South Coast 2007 AQMP.
    CARB also made technical changes to the inventories for diesel
trucks, buses, and certain categories of off-road mobile source engines
as part of its December 2010 rulemaking amending the In-Use On-Road
Truck and Bus Rule and the In-Use Off-Road Engine rule. Id. The State
estimates that these changes collectively reduce the 2002 base year
total inventory in the South Coast by 4 percent for NOX and
5 percent for PM2.5.\17\ These changes are small given the
normal and unavoidable uncertainties in all emissions inventories, and
therefore, do not change our basis for proposing to approve the base
year inventory or to find the baseline inventories adequate for SIP
planning purposes. We discuss the impact of these changes on the plan's
RFP and attainment demonstrations later in this notice.
---------------------------------------------------------------------------

    \17\ See Attachment 1 to the letter, Lynn Terry, Deputy
Executive Officer, CARB, to Elizabeth Adams, Deputy Director, Air
Division, US EPA Region 9, dated May 18, 2011 (``CARB Progress
Report supplement''), in the docket for today's proposal.
---------------------------------------------------------------------------

    We note that the District and CARB are currently working on
revisions to the South Coast AQMP to address the 2006 24-hour
PM2.5 standards. These revisions are due to EPA in December
2012 and will include the most current inventory information that is
available.

B. Reasonably Available Control Measures (RACM)/Reasonably Available
Control Technology (RACT) and Adopted Control Strategy

1. Requirements for RACM/RACT
    CAA section 172(c)(1) requires that each attainment plan ``provide
for the implementation of all reasonably available control measures as
expeditiously as practicable (including such reductions in emissions
from existing sources in the area as may be obtained through the
adoption, at a minimum, of reasonably available control technology),
and shall provide for attainment of the national primary ambient air
quality standards.'' EPA defines RACM as measures that a State finds
are both reasonably available and contribute to attainment as
expeditiously as practicable in its nonattainment area. Thus, what
constitutes RACM/RACT in a PM2.5 attainment plan is closely
tied to that plan's expeditious attainment demonstration. 40 CFR
51.1010; 72 FR 20586 at 20612. States are required to evaluate RACM/
RACT for direct PM2.5 and all of its attainment plan
precursors. 40 CFR 51.1002(c).
    Consistent with subpart 1 of Part D of the CAA, EPA is requiring a
combined approach to RACM and RACT for PM2.5 attainment
plans. Subpart 1, unlike subparts 2 and 4, does not identify specific
source categories for which EPA must issue control technology documents
or guidelines for what constitutes RACT, or identify specific source
categories for State and EPA evaluation during attainment plan
development. 72 FR 20586 at 20610. Rather, under subpart 1, EPA
considers

RACT to be part of an area's overall RACM obligation. Because of the
variable nature of the PM2.5 problem in different
nonattainment areas, EPA determined not only that states should have
flexibility with respect to RACT and RACM controls but also that in
areas needing significant emission reductions to attain the standards,
RACT/RACM controls on smaller sources may be necessary to reach
attainment as expeditiously as practicable. 72 FR 20586 at 20612,
20615. Thus, under the PM2.5 implementation rule, RACT and
RACM are those reasonably available measures that contribute to
attainment as expeditiously as practicable in the specific
nonattainment area. 40 CFR 51.1010; 72 FR 20586 at 20612.
    The PM2.5 implementation rule requires that attainment
plans include the list of measures the state considered and information
sufficient to show that a state met all requirements for the
determination of what constitutes RACM/RACT in its specific
nonattainment area. 40 CFR 51.1010. In addition, the rule requires that
the state, in determining whether a particular emissions reduction
measure or set of measures must be adopted as RACM/RACT, consider the
cumulative impact of implementing the available measures and adopt as
RACM/RACT any potential measures that are reasonably available
considering technological and economic feasibility if, considered
collectively, they would advance the attainment date by one year or
more. Id. Any measures that are necessary to meet these requirements
that are not already either federally promulgated, part of the state's
SIP, or otherwise creditable in SIPs must be submitted in enforceable
form as part of a state's attainment plan for the area. 72 FR 20586 at
20614.
    A more comprehensive discussion of the RACM/RACT requirement for
PM2.5 attainment plans and EPA's guidance for it can be
found in the PM2.5 implementation rule preamble at 72 FR
20586, at 20609-20633 and in section II.D. of the TSD for this
proposal.
2. RACM/RACT Demonstration in the South Coast 2007 AQMP and the 2007
State Strategy
    For the South Coast 2007 AQMP and the 2007 State Strategy, the
District, CARB and the local agency (through the South Coast's
metropolitan planning organization (MPO), the Southern California
Association of Governments (SCAG)), each undertook a process to
identify and evaluate potential reasonably available control measures
that could contribute to expeditious attainment of the PM2.5
standards in the South Coast nonattainment area. These RACM/RACT
analyses address control measures for sources of direct
PM2.5, NOX, SOX, and VOC, which are
the State's selected attainment plan precursors for the 1997
PM2.5 standards in the South Coast (see section V.C.3
below). We describe each agency's efforts below.
a. District's RACM/RACT Analysis and Adopted Control Strategy
    The District's RACM/RACT analysis, which focuses on stationary and
area source controls, is described in Chapter 6 and Appendix VI of the
South Coast 2007 AQMP.
    Since the 1970s, the District has adopted stationary source control
rules that have resulted in significant improvement of air quality in
the South Coast nonattainment area. When command and control rules were
no longer within the limitations of economic efficiency, the District
began using economic incentive approaches with programs such as the
Surplus Off-Road Opt-In for NOX (SOON) program and the Carl
Moyer program.18 19 While the District still relies on
command and control regulations, the District's control strategies are
now supplemented by market incentive and compliance flexibility
approaches where appropriate. These regulations and strategies have
yielded significant emissions reductions from sources under the
District's jurisdiction. In developing the South Coast 2007 AQMP, the
District conducted a process to identify RACM for the South Coast that
involved public meetings to solicit input, evaluation of EPA suggested
RACM and RACT, and evaluation of other air agencies' regulations. See
South Coast 2007 AQMP, Appendix VI.
---------------------------------------------------------------------------

    \18\ The Carl Moyer Memorial Air Quality Standards Attainment
Program (``Carl Moyer Program'') provides incentive grants for
engines, equipment and other sources of pollution that are cleaner
than required, providing early or extra emission reductions.
Eligible projects include cleaner on-road, off-road, marine,
locomotive and stationary agricultural pump engines. The program
achieves near-term reductions in emissions of NOX, PM,
and VOC or reactive organic gas (ROG) which are necessary for
California to meet its clean air commitments under the SIP.
    \19\ The SOON program provides funding assistance to applicable
fleets for the purchase of commercially-available low-emission
heavy-duty engines to achieve near-term reduction of NOX
emissions from in-use off-road diesel vehicles. All large fleets
with a total statewide equipment horsepower (hp) over 20,000 hp must
apply for funding. Fleets below 20,000 hp may voluntarily
participate in this program.
---------------------------------------------------------------------------

    To determine which measures would be feasible for the South Coast,
the District looked at measures implemented in other nonattainment
areas' plans (including the San Joaquin Valley, the San Francisco Bay
Area, Sacramento, Ventura, Dallas-Fort Worth, the Houston-Galveston
area, and by the Lake Michigan Air Directors Consortium, or LADCO), and
held meetings with CARB, technical experts, local government
representatives, and the public during development of the South Coast
2007 AQMP. The District sponsored an AQMP summit, which generated 200
potential control measures. In addition, the District reviewed the list
of control measures suggested for consideration in EPA's
PM2.5 implementation rule. The District also reevaluated all
82 District rules and regulations. The District then screened the
identified measures and rejected those that affected few or no sources
in the South Coast, had already been adopted as rules, or were in the
process of being adopted. The District evaluated the remaining measures
using baseline inventories, available control technologies, and
potential emission reductions as well as whether the measure could be
implemented on a schedule that would contribute to attainment of the
PM2.5 standard assuming a 2015 deadline. South Coast 2007
AQMP, Appendix VI.
    In general, EPA proposes to find that the District's current rules
and regulations are equivalent to, or more stringent than, those
developed by other air districts with respect to emissions of
PM2.5 and PM2.5 precursors. The District is
exploring several options for reducing emissions further. These include
the feasibility of lowering emission limits and increasing levels of
control in order to promote cleaner stationary source technologies;
lowering the VOC content of coatings and solvents; establishing
standards and test methods for generic equipment and lowering release
or leak thresholds; improving leak detection, repair, inspection and
maintenance; and adding best management practices to rules.
    Based on its RACM/RACT evaluation for stationary and area sources
under its jurisdiction, the District developed 37 stationary source
control measures which comprised all measures included in other
districts' AQMPs, as well as some new innovative measures. The District
determined that the few available measures that District staff did not
include would not advance the attainment date or contribute to RFP due
to the insignificant or unquantifiable emissions reductions that they
would potentially generate. See South Coast 2007 AQMP, Appendix VI,
page VI-7. Since submittal of the AQMP in 2007, the District has
completed action on the majority of

these rules and submitted them to EPA for approval into the SIP.
    From October 2002 through June 2006, the District adopted
approximately 17 rules to address its commitment to achieve the
reductions committed to in the 2003 AQMP for the South Coast. These
rules included controls on VOC emissions from refineries and chemical
plants, co-composting operations, architectural coatings, solvent
cleaning operations, oil and gas production wells, and livestock waste.
Many of the adopted rules achieved more estimated reductions in VOC,
NOX and SOX than were expected in the 2003 AQMP.
A summary of these rules, which are included in the baseline emissions
estimates for the South Coast 2007 AQMP, is provided in Table 1-2 of
the South Coast 2007 AQMP. See South Coast 2007 AQMP, Chapter 1, Table
1-2 and Chapter 4, page 4-6, and Table B-1 in Appendix B of the TSD for
today's action.
    In addition to the rules adopted for the 2003 AQMP, the District
has also made new commitments in its South Coast 2007 AQMP to achieve
further reductions from VOC, NOX, SOX and direct
PM2.5 sources in the South Coast area. The District
committed to adopt and submit measures that will achieve the following
additional emissions reductions: 10.8 tpd NOX, 10.4 tpd VOC,
2.9 tpd direct PM2.5 and 2.9 tpd SOX.\20\ See
2011 Progress Report, Appendix E, Table 1. The District expects to meet
its emissions reductions commitments for each of the pollutants by
adopting new control measures and programs found in the Table 4-2A of
the South Coast 2007 AQMP (see South Coast 2007 AQMP, page 4-10 and
CARB Staff Report on South Coast 2007 AQMP, p. 18), as updated in the
2011 Progress Report, Appendix E, Tables 2 through 5 and from
additional actions summarized in the CARB Staff Report on the South
Coast 2007 AQMP (see CARB Staff Report on South Coast 2007 AQMP, p.
17). The new control measures and additional actions are estimated to
achieve more of the District's emission reduction commitments. They
include new rules to regulate lubricants, consumer products, non-
RECLAIM ovens, dryers and furnaces, space heaters, facility
modernizations, livestock waste, residential wood burning, and
commercial cooking. The South Coast 2007 AQMP also identifies 22
measures (beyond the new control measures and additional actions just
discussed) for further review, which may also yield additional
reductions towards the District's commitments. As discussed above, the
District's commitment is to achieve the estimated total tonnage
reductions of each pollutant because specific control measures and
actions as adopted may provide more or less reductions than estimated
in the South Coast 2007 AQMP.
---------------------------------------------------------------------------

    \20\ CARB uses the term ROG (reactive organic gases) where we
use the term VOC (volatile organic compounds). We will use the term
VOC in this notice to refer to both ROG and VOC.
---------------------------------------------------------------------------

    Finally, EPA notes that since the adoption of the South Coast 2007
AQMP, the District has already adopted and submitted many of the rules
in the South Coast 2007 AQMP that help fulfill the District's
enforceable commitments for additional emission reductions of
NOX, VOC, direct PM2.5 and SOX in the
South Coast area. Table 3 below summarizes the status of these new
rules.

                          Table 2--South Coast
           [Annual average day emissions in tons per day] \a\
------------------------------------------------------------------------
                                           SIP commitment by 2014
            Pollutant             --------------------------------------
                                    Commitment    Achieved     Balance
------------------------------------------------------------------------
VOC..............................         10.4        14.4         +4.0
NOX..............................         10.8         7.60        -3.2
PM2.5............................          2.9         1.00        -1.9
SOX..............................          2.9         4.01        +1.11
------------------------------------------------------------------------
Source: 2011 Progress Report, Appendix F, Table 1. The ``Achieved''
  column in Table 2 reflects District rules submitted to EPA. Table 3
  reflects emissions reductions EPA can credit towards the attainment
  demonstration.

          Table 3--Status of District Short- and Intermediate-Term Control Measures Credited in South Coast 2007 AQMP Attainment Demonstration
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Emissions reduction
           Control measure              Rule No.               Title               commitment in South     Emissions reductions         SIP status
                                                                                Coast 2007 AQMP           achieved \a\
--------------------------------------------------------------------------------------------------------------------------------------------------------
BCM-03..............................          445  Woodburning fireplaces and    1.0 tpd PM2.5..........  1.0 tpd PM2.5; 0.44     74 FR 27716, 6/11/09.
                                                    wood stoves.                                           tpd VOC; 0.06 tpd
                                                                                NOX; 0.01 tpd SOX.
BCM-05..............................         1138  Underfired charbroilers.....  1.1 tpd PM2.5..........  ......................  66 FR 36170, 7/11/
                                                                                2001.
CTS-01..............................         1144  Metalworking fluids and       1.9 tpd VOC............  3.9 tpd VOC...........  75 FR 40726, 07/14/10.
                                                    direct-contact lubricants.
CMB-01..............................         1147  NOX reductions from           3.5 tpd NOX............  3.5 tpd NOX...........  75 FR 46845, 08/04/10.
                                                    miscellaneous sources.
CMB-02..............................         2002  Further SOX reductions from   2.9 tpd SOX............  4.0 tpd SOX...........  76 FR 30896, 5/27/11.
                                                    RECLAIM.
FUG-02..............................          461  Emissions Reductions from     3.7 tpd VOC............  VOC reductions          71 FR 18216, 4/11/06.
                                                    Gasoline Transfer and                                  substituted by Rule
                                                    Dispensing Facilities.                                 1143.
FUG-04..............................         1149  Storage Tank and Pipeline     None...................  0.04 tpd VOC..........  74 FR 67821, 12/21/09.
                                                    Cleaning and Degassing.
CMB-03..............................         1111  Further NOX reductions from   0.8 tpd NOX............  0.01 tpd NOX..........  75 FR 46845, 8/4/10.
                                                    space heaters.

MCS-01..............................       1110.2  Liquid and gaseous fuels--    .......................  0.6 tpd NOX; 0.3 tpd    74 FR 18995, 4/27/09.
                                                    stationary ICEs.                                       VOC.
FLX-02..............................  ...........  Refinery pilot program......  0.7 tpd VOC; 0.4 tpd     VOC reductions          ......................
                                                                                PM2.5.                   substituted by Rule
                                                                                1143.
MOB-05..............................         2251  AB923 LDV high emitter        0.8 tpd VOC; 0.4 tpd     ......................  No rule associated
                                                    program.                      NOX.                                             with this measure.
MOB-06..............................  ...........  AB923 MDV high emitter        0.5 tpd VOC; 0.5 tpd     ......................  No rule associated
                                                    program.                      NOX.                                             with this measure.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                         Measures Proposed for EPA Action or Soon to be Proposed for EPA Action
--------------------------------------------------------------------------------------------------------------------------------------------------------
MCS-05..............................         1127  Livestock waste.............  0.8 tpd VOC.
MCS-01..............................         1146  NOX from industrial,          1.2 tpd NOX; 0.4 tpd     ......................  Proposed limited
                                                    institutional, & commercial   PM2.5; 2.0 tpd VOC.                              approval/limited
                                                    boilers, steam generators,                                                     disapproval signed
                                                    and process heaters.                                                           June 21, 2011.
MCS-01..............................       1146.1  NOX from small ind, inst, &   .......................  ......................  Proposed limited
                                                    comm'l boilers, steam gens,                                                    approval/limited
                                                    and proc. Htrs.                                                                disapproval signed
                                                                                June 21, 2011.
CTS-04..............................         1143  Consumer Paint Thinners and   2.1 tpd VOC............  9.7 tpd VOC...........  Proposed approval
                                                    Multi-Purpose Solvents.                                                        signed June 23, 2011.
--------------------------------------------------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------
                             SIP Commitment vs. SIP-Creditable Emissions Reductions
----------------------------------------------------------------------------------------------------------------
SIP commitment--PM2.5................  2.9 tpd..............  Total SIP-creditable PM2.5    1.2 tpd.
                                                               reductions.
SIP commitment--NOX..................  10.8 tpd.............  Total SIP-creditable NOX      4.2 tpd.
                                                               reductions.
SIP commitment--VOC..................  10.4 tpd.............  Total SIP-creditable VOC      14.4 tpd.
                                                               reductions.
SIP commitment--SOX..................  2.9 tpd..............  Total SIP-creditable SOX      4.01 tpd.
                                                               reductions.
----------------------------------------------------------------------------------------------------------------
\a\ From 2011 Progress Report, Appendix F, Tables 2-5. EPA can only credit rules that have been adopted,
  submitted to EPA, and approved for credit in the SIP.

b. CARB's RACM Analysis and Adopted Control Strategy
    Source categories for which CARB has primary responsibility for
reducing emissions in California include most new and existing on- and
off-road engines and vehicles, motor vehicle fuels, and consumer
products.
    Given the need for significant emissions reductions from mobile and
area sources to meet the NAAQS in California nonattainment areas, the
State of California has been a leader in the development of some of the
most stringent control measures nationwide for on-road and off-road
mobile sources and the fuels that power them. In addition, California
has unique authority under CAA section 209 (subject to a waiver by EPA)
to adopt and implement new emission standards for many categories of
on-road vehicles and engines, and new and in-use off-road vehicles and
engines.
    California's emissions standards have reduced new car emissions by
99 percent and new truck emissions by 90 percent from uncontrolled
levels. 2007 State Strategy, p. 37. The State is also working with EPA
on goods movement activities and is implementing programs to reduce
emissions from ship auxiliary engines, locomotives, harbor craft and
new cargo handling equipment. In addition, the State has standards for
lawn and garden equipment, recreational vehicles and boats, and other
off-road sources that require newly manufactured equipment to be 80-98%
cleaner than their uncontrolled counterparts. Id. Finally, the State
has adopted many measures that focus on achieving reductions from in-
use mobile sources that include more stringent inspection and
maintenance (I/M) or ``Smog Check'' requirements, truck and bus idling
restrictions, and various incentive programs.
    Appendix A of the TSD includes a list of all measures adopted by
CARB between 1990 and the beginning of 2007. These measures, reductions
from which are reflected in the Plan's baseline inventories, fall into
two categories: Measures that are subject to a waiver of Federal pre-
emption under CAA section 209 (section 209 waiver measures or waiver
measures) and those for which the State is not required to obtain a
waiver (non-waiver measures). EPA allows emission reduction credit for
measures that are granted a waiver from Federal preemption through the
CAA section 209 waiver process. See section II.F.4.a.i. of the TSD and
EPA's final approval of the San Joaquin Valley 1-Hour Ozone Plan at 75
FR 10420, 10424 (March 8, 2010). Generally, the State's baseline non-
waiver measures have been approved by EPA into the SIP and are fully
creditable for meeting CAA requirements. See TSD, Appendix A.
    CARB developed its proposed 2007 State Strategy after an extensive
public consultation process to identify potential SIP measures.\21\
From this process, CARB identified and committed to propose 15 new
defined measures. These measures focus on cleaning up the in-use fleet
as well as increasing the stringency of emissions standards for a
number of engine categories, fuels, and consumer products. Many, if not
most, of these measures are being proposed for

adoption for the first time anywhere in the nation. They build on
CARB's already comprehensive program described above that addresses
emissions from all types of mobile sources through both regulations and
incentive programs. See Appendix A of the TSD. Table 4 below lists the
defined measures in the 2007 State Strategy and their current adoption
and approval status. Table 5 provides the State's current estimate of
the emissions reductions in the South Coast nonattainment area from
these measures.
---------------------------------------------------------------------------

    \21\ More information on this public process including
presentations from the workshops and symposium that preceded the
adoption of the 2007 State Strategy can be found at http://www.arb.ca.gov/planning/sip/2007sip/2007sip.htm.

       Table 4--2007 State Strategy Defined Measures Scheduled for
          Consideration and Current Status (Updated April 2011)
------------------------------------------------------------------------
                                 Expected action
         State measure                 year            Current status
------------------------------------------------------------------------
                 Defined Measures in 2007 State Strategy
------------------------------------------------------------------------
Smog Check Improvements.......  2007-2009........  Elements approved 75
                                                    FR 38023 (July 1,
                                                    2010). \22\
Expanded Vehicle Retirement     2007.............  Adopted CARB June
 (AB118).                                           2009; Bureau of
                                                    Automotive Repair
                                                    September 2010.
Modifications to Reformulated   2007.............  Approved, 75 FR 26653
 Gasoline Program.                                  (May 2, 2010).
Cleaner In-use Heavy Duty       2007, 2008, 2010.  Proposed approval
 Trucks.                                            signed June 29,
                                                    2011.
Auxiliary Ship Cold Ironing     2007-2008........  Adopted December
 and Other Clean Technologies.                      2007.
Cleaner Main Ship Engines and   Fuel: 2008-2011..  Proposed approval
 Fuels.                         Engines: 2008....   signed June 29,
                                                    2011.
Port Truck Modernization......  2007, 2008, 2010.  Adopted December 2007
                                                    and December 2008.
Accelerated Introduction of     2008.............  Implementation 2012.
 Cleaner Locomotives.
Clean Up Existing Harbor        2007, 2010.......  Adopted November
 Crafts.                                            2007, revised June
                                                    2010.
Cleaner In-Use Off-Road         2007, 2010.......  Waiver action
 Engines.                                           pending.
New Emissions Standards for     2013.............  Partial adoption,
 Recreational Boats.                                July 2008;
                                                    additional action
                                                    expected 2013.
Expanded Off-Road Recreational  2013.............  Adopted November
 Vehicle Emissions Standards.                       2008; additional
                                                    action expected
                                                    2013.
Enhanced Vapor Recovery for     2008.              .....................
 Above Ground Storage Tanks.
Additional evaporative          2009, 2013.        .....................
 emissions standards.
Consumer Products Program (I    2008, 2009, 2011.  Phase I approved
 and II).                                           November 4, 2009, 74
                                                    FR 57074; Phase II
                                                    approved May 12,
                                                    2011, 76 FR 27613.
------------------------------------------------------------------------
Sources: 2009 State Strategy Update, p. 23 and 2011 Progress Report,
  Table 1, p. 8. Additional information from http://www.ca.arb.gov.

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

    \22\ California Assembly Bill 2289, passed in 2010, requires the
Bureau of Automotive Repair to direct older vehicles to high
performing auto technicians and test stations for inspection and
certification effective 2013. Reductions shown for the SmogCheck
program in the 2011 Progress Report do not include reductions from
AB 2289 improvements. See CARB Progress Report supplement,
attachment 5.

   Table 5--Currently Creditable Emissions Reductions From Defined Measures in the 2007 State Strategy for the
                             South Coast, as Revised April 2011 (Tons per Day 2014)
----------------------------------------------------------------------------------------------------------------
                                                                 Direct
                        State measure                            PM2.5         NOX          VOC          SOX
----------------------------------------------------------------------------------------------------------------
Smog Check Improvements (BAR)...............................          0.3          2.6          8.6          0
Cleaner In-Use Heavy-Duty Trucks............................          2.6         18.6          3.3          0
Cleaner In-Use Off-Road Equipment (> 25 hp).................          0            0.5          0.1          0
Ship Auxiliary Engine Cold Ironing & Clean Tech.............          0.1          8.1          0.2          0.3
Cleaner Main Ship Engines and Fuel--Main Engines............          3.5         17.6          0.5         37
Clean Up Existing Harbor Craft..............................          0.2          4.1          0.1          0
----------------------------------------------------------------------------------------------------------------
Source: 2011 Progress Report, Appendix E, pp. 2 and 3. Only defined measures with direct PM2.5, VOC, SOX and/or
  NOX, reductions in the South Coast are shown here.

    In addition to the State's commitments to propose defined new
measures, the 2007 State Strategy includes an enforceable commitment
for emissions reductions sufficient, in combination with existing
measures and the District's commitments, to attain the PM2.5
NAAQS in the South Coast nonattainment area by the requested attainment
date of April 5, 2015. For the South Coast, these emission reductions
commitments are to achieve 152 tpd of NOX, 46 tpd of VOC, 9
tpd of direct PM2.5, and 20 tpd of SOX (see 2007
State Strategy, p. 63 and CARB Resolution 07-28, Attachment B, p. 6).
The nature of this commitment is described in the State Strategy as
follows:

    ``The total emission reductions from the new measures necessary
to attain the federal standards are an enforceable State commitment
in the SIP. While the proposed State Strategy includes estimates of
the emission reductions from each of the individual new measures, it
is important to note that the commitment of the State Strategy is to
achieve the total emission reductions necessary to attain the
federal standards, which would be the aggregate of all existing and
proposed new measures combined. Therefore, if a particular measure
does not get its expected emission reductions, the State still
commits to achieving the total aggregate emission reductions,
whether this is realized through additional reductions from the new
measures or from alternative control measures or incentive programs.
If actual emission decreases occur in any air basin for which
emission reduction commitments have been

made that are greater than the projected emissions reductions from
the adopted measures in the State Strategy, the actual emission
decreases may be counted toward meeting ARB's total emission
reduction commitments.''

CARB Resolution 07-28 (September 27, 2007), Appendix B, p. 3.
c. The Local Jurisdiction's RACM Analysis
    The local jurisdiction's RACM analysis was conducted by the
metropolitan planning organization (MPO) for the South Coast region,
the Southern California Association of Governments (SCAG). This
analysis, which focused on transportation control measures (TCMs), and
the results of this analysis are described in Appendix IV-C of the
South Coast 2007 AQMP. The TCMs in the South Coast 2007 AQMP are
derived from TCM projects in the 2006 SCAG Regional Transportation
Improvement Program (RTIP). This analysis, described beginning on page
49 of Appendix IV-C of the South Coast 2007 AQMP, resulted in extensive
local government commitments to implement programs to reduce auto
travel and improve traffic flow. South Coast 2007 AQMP page 6-6 and
Appendix IV-C. SCAG also provided reasoned justifications for any
measures that it did not adopt. Attachment A to Appendix IV-C contains
an extensive list of TCMs in process and newly programmed TCMs. The
enforceable commitment from SCAG and the transportation agencies was to
fund and implement projects in the first two years of the 2006 Regional
Transportation Improvement Program (RTIP).
3. Proposed Actions on RACM/RACT Demonstration and Adopted Control
Strategy
    We propose to find that there are, at this time, no additional
reasonably available measures that individually or collectively would
advance attainment of the PM2.5 NAAQS in the South Coast
nonattainment area by one year or more. This proposal is based on our
review of potential RACM/RACT in the revised 2007 South Coast AQMP and
the 2007 State Strategy; the District's and State's adopted control
strategies, including their commitments to adopt measures and their
progress in meeting those commitments; and our proposed concurrence
(discussed below in section V.C.3) with the State's determination that
SOX, NOX, and VOC are, and ammonia is not,
attainment plan precursors per 40 CFR 51.1002(c). Therefore, we propose
to find that the relevant portions of the South Coast 2007 AQMP and the
2007 State Strategy provide for the implementation of RACM/RACT as
required by CAA section 172(c)(1) and 40 CFR 51.1010.
    Because they will strengthen the California SIP, we are also
proposing to approve, the District's commitments to adopt and implement
specific control measures on the schedule identified in Tables 2-5 of
Appendix E in the 2011 Progress Report, to the extent that these
commitments have not yet been fulfilled, and to achieve specific
aggregate emissions reductions of direct PM2.5,
NOX, VOC and SOX by specific years as given in
Table 1 of the 2011 Progress Report (and Table 2 in today's proposal).
    We are also proposing to approve CARB's commitments to propose
certain defined measures, as given on Table B-1 in Appendix B of the
2011 Progress Report, and to achieve total aggregate emissions
reductions necessary to attain the 1997 PM2.5 standards in
the South Coast nonattainment area, whether these reductions are
realized from the new measures, alternative control measures, incentive
programs, or other actual emissions decreases. See CARB Resolution 07-
28 (September 27, 2007), Appendix B, p. 3. This commitment is to
aggregate emissions reductions of 152 tpd of NOX, 46 tpd of
VOC, 9 tpd of direct PM2.5, and 20 tpd of SOX in
the South Coast by 2014 (see page 20 of the 2009 State Strategy Status
Report).

C. Attainment Demonstration

1. Requirements for Attainment Demonstration
    CAA section 172 requires a State to submit a plan for each of its
nonattainment areas that demonstrates attainment of the applicable
ambient air quality standard as expeditiously as practicable but no
later than the specified attainment date. Under the PM2.5
implementation rule, this demonstration should consist of four parts:
    (1) Technical analyses that locate, identify, and quantify sources
of emissions that are contributing to violations of the
PM2.5 NAAQS;
    (2) Analyses of future year emissions reductions and air quality
improvement resulting from already-adopted national, State, and local
programs and from potential new State and local measures to meet the
RACT, RACM, and RFP requirements in the area;
    (3) Adopted emissions reduction measures with schedules for
implementation; and
    (4) Contingency measures required under section 172(c)(9) of the
CAA.

See 40 CFR 51.1007; 72 FR 20586, at 20605.

    The requirements for the first two parts are described in the
sections on emissions inventories and RACM/RACT above and in the
sections on air quality modeling, PM2.5 precursors,
extension of attainment date, and attainment demonstrations that follow
immediately below. Requirements for the third and fourth parts are
described in the sections on the control strategy and the contingency
measures, respectively.
2. Air Quality Modeling in the South Coast 2007 AQMP
    The procedures for modeling attainment of the PM2.5
NAAQS as part of an attainment SIP are contained in EPA's ``Guidance on
the Use of Models and Other Analyses for Demonstrating Attainment of
Air Quality Goals for the 8-Hour Ozone and PM2.5 NAAQS and
Regional Haze.'' (Guidance).\23\ A brief description of the modeling
used to support South Coast's attainment demonstration follows. For
more detailed information about the modeling, please refer to the TSD
associated with this rulemaking, which can be found in the docket for
today's action.
---------------------------------------------------------------------------

    \23\ The guidance is available at http://www.epa.gov/ttn/scram/guidance_sip.htm and in the docket for today's action.
---------------------------------------------------------------------------

    Air quality modeling is used to establish emission attainment
targets, a combination of emissions of PM2.5 and
PM2.5 precursors that the nonattainment area can accommodate
without exceeding the NAAQS, and to assess whether the proposed control
strategy will result in attainment of the NAAQS by the applicable
attainment date. Air quality modeling is performed for a base year and
compared to air quality monitoring data to determine model performance.
Once the performance is determined to be acceptable, future year
emission inventory changes are simulated to determine the relationship
between emission reductions and changes in ambient air quality
throughout the nonattainment area.
    The attainment demonstration for the South Coast nonattainment area
is based on the CAMx model using the ``one atmosphere'' approach
comprised of the carbon bond IV (CB-IV) gas phased chemistry and a
static two-mode particle size aerosol.\24\ CAMx annual average
PM2.5 modeling simulations were generated for 2005 and 2014
baseline emissions scenarios and for a 2014 controlled emissions
scenario by

the District. District staff compared the base year model output to
speciated particulate data measured in 2005 as part of the Multiple Air
Toxics III (MATES-III) program. Model specifications, such as boundary
conditions, domain size, and resolution, meet EPA criteria and are
discussed in the TSD. Model performance for total mass (the sum of
specific individual species), as well as for specific individual
species, is adequate and is discussed in the TSD.
---------------------------------------------------------------------------

    \24\ CAMx is the Comprehensive Air Quality Model with
extensions, an Eulerian photochemical dispersion model that allows
for integrated ``one-atmosphere'' assessments of gaseous and
particulate air pollution (ozone, PM2.5, PM10,
air toxics) over many scales ranging from sub-urban to continental.
---------------------------------------------------------------------------

    The District's attainment analysis follows EPA's guideline
technique of applying component-specific relative response factors
(RRF) to monitored data throughout the South Coast nonattainment area.
A RRF is the ratio of the model's future to current (baseline)
predictions at a monitor. Future PM2.5 concentrations are
estimated at existing monitoring sites by multiplying a modeled RRF at
the grid cell locations of each monitor by the observation-based,
monitor-specific, ``baseline'' design value. A separate RRF is
calculated for each of the PM2.5 precursors. Future
PM2.5 design values were estimated by District staff at
existing monitoring sites throughout the South Coast nonattainment area
by multiplying modeled RRFs for each monitor times the observed
``component-specific design value.'' The future PM2.5 design
values were then compared to the annual and 24-hour NAAQS to
demonstrate attainment at each site. The maximum 2014 predicted
PM2.5 annual design value is 15.0 [mu]g/m\3\ or lower.\25\
---------------------------------------------------------------------------

    \25\ See 40 CFR part 50 Appendix N, 4.1(a). A predicted design
value of 15.04 [mu]g/m\3\ or lower is considered modeled attainment
of the annual standard.
---------------------------------------------------------------------------

    The District also performed the recommended unmonitored area
analysis and it indicated that there were no additional nonattainment
problems in unmonitored areas. The future PM2.5 design
values were also compared to the 24-hour PM2.5 NAAQS to
demonstrate attainment at each site. The maximum predicted 2014 24-hour
PM2.5 design value at any site is 56.6 [mu]g/m\3\; this is
lower than the 24-hour PM2.5 NAAQS of 65 [mu]g/m\3\. EPA
guidance also recommends the use of supplemental data analyses to
support the air quality modeling. The District used air quality trends
and emission inventory trends as ``weight of evidence'' to support the
air quality modeling for the attainment demonstration.
    The District used its air quality modeling to establish emissions
reduction targets to be used in developing the control strategy for the
nonattainment SIP. Once a proposed control strategy was developed, the
District then used the photochemical modeling to verify that the
projected emissions reductions would result in attainment of the 1997
PM2.5 standards throughout the South Coast nonattainment
area by the target attainment date of 2014. The estimated carrying
capacities for the South Coast nonattainment area are included in Table
6.26 27
---------------------------------------------------------------------------

    \26\ ``Carrying capacity'' is defined as the maximum level of
emissions that enable the attainment and maintenance of an ambient
air quality standard for a pollutant. (see South Coast 2007 AQMP,
page 5-27.)
    \27\ The CARB Staff Report for the South Coast 2007 AQMP
presents a slightly different emissions carrying capacity which
relies more heavily on reductions of primary PM2.5 and
less heavily on reductions of precursors to PM2.5. The
Staff Report's emission carrying capacity estimates are
PM2.5--86 tons/day, NOX--460 tons/day,
SOX--20 tons/day, and VOC--474 tons/day (see CARB Staff
Report on the South Coast AQMP, page ES-3).

   Table 6--Emissions Carrying Capacity Estimates for the South Coast
                 Nonattainment Area for PM2.5 Attainment
                 [Tons/day, based on planning inventory]
------------------------------------------------------------------------
      PM2.5               NOX                SOX               VOC
------------------------------------------------------------------------
          87                454                 19               469
------------------------------------------------------------------------

    We are proposing to approve the air quality modeling demonstration
in the South Coast 2007 AQMP as meeting the requirements of the CAA
consistent with EPA guidance. We provide further discussion in the TSD.
Effect of Inventory Changes on the Air Quality Modeling and Attainment
Demonstrations
    As discussed above in section V.A., CARB has recently updated the
inventories for several mobile source categories for both the base and
future years as well as revised the economic forecasts on which the
future inventories were based. Ideally, new attainment demonstration
modeling would be performed to evaluate the effect of these updates and
revisions; however, remodeling is a substantial undertaking and would
not necessarily change the basic conclusions of the existing attainment
demonstration analysis.
    Relative to emissions in the South Coast 2007 AQMP, the decreases
in the base year 2002 emissions inventory due to the inventory updates
are about 4 percent for NOX and 5 percent for direct
PM2.5 emissions. CARB Progress Report supplement, Attachment
1. For the 2014 attainment target year, the decreases in the projected
2014 baseline due to both methodology changes (e.g., changes to
construction equipment emissions factors) and the revised economic
forecasts are 10 percent for NOX, 2 percent for direct
PM2.5, 2 percent for VOC, and a 30 percent increase for
SOX.\28\ The effect of the revisions in the target year as
compared to the base year are about the same for direct
PM2.5, and somewhat larger for NOX. The overall
effect of the inventory revisions is thus to increase the emission
reductions from base year to attainment year, in a relative sense.
Likewise, the revisions would tend to make the relative reduction
factors (factors used to scale the modeling results) lower, decreasing
the projected PM2.5 concentrations in the attainment year
and effectively making the attainment demonstration over-estimate the
level of emissions reductions needed to attain. Based on model
sensitivity results provided by CARB, EPA estimates that ambient
concentrations would be slightly lower in the attainment year due to
the emission inventory revisions. EPA therefore concludes that the
attainment demonstration remains valid, despite the emission inventory
changes.
---------------------------------------------------------------------------

    \28\ By 2014, SOX emissions reach the attainment
target due to adopted State and District rules.
---------------------------------------------------------------------------

3. PM2.5 Precursors Addressed in the South Coast 2007 AQMP
    EPA recognizes NOX, SO2, VOCs, and ammonia as
the main precursor gases associated with the formation of secondary
PM2.5 in the ambient air. These gas-phase PM2.5
precursors undergo chemical reactions in the atmosphere to form
secondary particulate matter. Formation of secondary PM2.5
depends on numerous factors including the concentrations of precursors;
the concentrations of other gaseous reactive species; atmospheric
conditions including solar radiation, temperature, and relative
humidity; and the interactions of precursors with preexisting particles
and with cloud or fog droplets. 72 FR 20586, at 20589.
    As discussed previously, a state must submit emissions inventories
for each of the four PM2.5 precursor pollutants. 72 FR
20586, at 20589 and 40 CFR 51.1008(a)(1). However, the overall
contribution of different precursors to PM2.5 formation and
the effectiveness of alternative potential control measures will vary
by area. Thus, the precursors that a state should regulate to attain
the PM2.5 NAAQS could also vary to some extent from area to
area. 72 FR 20586, at 20589.

    In the PM2.5 implementation rule, EPA did not make a
finding that all potential PM2.5 precursors must be
controlled in each specific nonattainment area. See 72 FR 20586, at
20589. Instead, for the reasons explained in the rule's preamble, a
state must evaluate control measures for sources of SO2 in
addition to sources of direct PM2.5 in all nonattainment
areas. 40 CFR 51.1002(c) and (c)(1). A state must also evaluate control
measures for sources of NOX unless the State and/or EPA
determine that control of NOX emissions would not
significantly reduce PM2.5 concentrations in the specific
nonattainment area. 40 CFR 51.1002(c)(2). In contrast, EPA has
determined in the PM2.5 implementation rule that a state
does not need to address controls for sources of VOC and ammonia unless
the state and/or EPA make a technical demonstration that controls on
such sources would significantly contribute to reducing
PM2.5 concentrations in the specific nonattainment area at
issue. 40 CFR 51.1002(c)(3) and (4). Such a demonstration is required
``if the administrative record related to development of its SIP shows
that the presumption is not technically justified for that area.'' 40
CFR 51.1002(c)(5).
    ``Significantly contributes'' in this context means that a
significant reduction in emissions of the precursor from sources in the
area would be projected to provide a significant reduction in
PM2.5 concentrations in the area. 72 FR 20586 at 20590.
Although EPA did not establish a quantitative test for determining what
constitutes a significant change, EPA noted that even relatively small
reductions in PM2.5 levels are estimated to result in
worthwhile public health benefits. Id.
    EPA further explained that a technical demonstration to reverse the
presumption for NOX, VOC, or ammonia in any area could
consider the emissions inventory, speciation data, modeling
information, or other special studies such as monitoring of additional
compounds, receptor modeling, or special monitoring studies. 72 FR
20586 at 20596-20597. These factors could indicate that the emissions
or ambient concentration contributions of a precursor, or the
sensitivity of ambient concentrations to changes in precursor
emissions, differs for a specific nonattainment area from the
presumption EPA established for that precursor in the PM2.5
implementation rule.
    In the South Coast nonattainment area, PM2.5 can be
directly emitted, such as from road dust, diesel soot, combustion
products, and other sources (``primary particles''), or formed through
atmospheric chemical reactions of precursor chemicals (``secondary
particles''). Examples of secondary particles include sulfates,
nitrates, and complex carbon compounds formed from reactions of
NOX, SOX, VOC, and ammonia. The attainment
demonstration for the South Coast PM2.5 nonattainment area
addresses ammonium nitrate and ammonium sulfate because they represent
a dominant fraction of PM2.5 components in this area and are
formed through secondary reactions of the precursors NOX,
SOX, VOC and ammonia. The District's analysis indicates that
SOX reductions followed by directly-emitted PM2.5
and NOX reductions provide the greatest ambient
PM2.5 reductions. VOC reductions can also contribute to
improving ambient PM2.5 concentrations and will occur
concurrently as a result of the District's 8-hour ozone NAAQS
strategy.\29\ The PM2.5 implementation rule allows States or
EPA to evaluate which PM2.5 precursors should be precursors
for regulatory purposes in a particular nonattainment area, based on
the facts and circumstances of such area. SCAQMD has elected to
consider VOCs as regulatory precursors for the purpose of this SIP,
based on their modeling analysis, which considered the sensitivity of
PM2.5 formation to VOC emission reduction. EPA agrees that
the District's determination to consider VOC as a precursor for this
SIP is appropriate in this nonattainment area.
---------------------------------------------------------------------------

    \29\ See page 5-17 of Chapter 5 of the South Coast 2007 AQMP. We
approved the South Coast RACT SIP on December 18, 2008 (see 73 FR
76947) as complying with the relevant CAA requirements for RACT SIPs
for 8-hour ozone.
---------------------------------------------------------------------------

    Starting in 2011, the PM2.5 implementation rule requires
that states must also address condensable particulate matter (CPM),
including estimates of CPM in emissions inventories, modeling, and
control strategies.
4. Extension of the Attainment Date
    CAA section 172(a)(2) provides that an area's attainment date
``shall be the date by which attainment can be achieved as
expeditiously as practicable, but no later than 5 years from the date
such area was designated nonattainment * * *, except that the
Administrator may extend the attainment date to the extent the
Administrator determines appropriate, for a period no greater than 10
years from the date of designation as nonattainment considering the
severity of nonattainment and the availability and feasibility of
pollution control measures.''
    Because the effective date of designations for the 1997
PM2.5 standards was April 5, 2005 (70 FR 944), the initial
attainment date for PM2.5 nonattainment areas is as
expeditiously as practicable but not later than April 5, 2010. For any
areas that are granted a full five-year attainment date extension under
section 172, the attainment date would be no later than April 5, 2015.
    Section 51.1004 of the PM2.5 implementation rule
addresses the attainment date requirement. Section 51.1004(b) requires
a State to submit an attainment demonstration justifying its proposed
attainment date and provides that EPA will approve an attainment date
when we approve that demonstration.
    States that request an extension of the attainment date under CAA
section 172(a)(2) must provide sufficient information to show that
attainment by April 5, 2010 is impracticable due to the severity of the
nonattainment problem in the area and the lack of available and
feasible control measures to provide for faster attainment. 40 CFR
51.1004(b). States must also demonstrate that all RACM and RACT for the
area are being implemented to bring about attainment of the standard by
the most expeditious alternative date practicable for the area. 72 FR
20586, at 20601.
    For urban areas nationwide, the South Coast nonattainment area has
the second highest average annual mean PM2.5 concentration
(ranking only behind the San Joaquin Valley in California for the 1997
PM2.5 standards). Annual PM2.5 concentrations
recorded over the last few years at the Mira Loma monitoring site
continue to exceed the 1997 PM2.5 NAAQS.\30\ The
PM2.5 problem in the South Coast is complex, caused by both
direct PM2.5 and secondary PM2.5, and compounded
by the topographical and meteorological conditions for the area that
are very conducive to the formation and concentration of
PM2.5 particles. South Coast 2007 AQMP, chapter 4.
---------------------------------------------------------------------------

    \30\ See footnote 2.
---------------------------------------------------------------------------

    As discussed in section V.B.2. above, the District's strategy for
attaining the PM2.5 standard relies on reductions of
directly-emitted PM2.5 as well as the PM2.5
precursor pollutants NOX, VOC, and SOX. The South
Coast nonattainment area needs significant reductions in
PM2.5, NOX, VOC, and SOX to
demonstrate attainment. Further reducing these pollutants is
challenging, because the State and District have already adopted
stringent control measures for most

sources of direct PM2.5, NOX, VOC, and
SOX emissions. Moreover, attainment in the South Coast
nonattainment area depends on emissions reductions that offset the
emissions increases associated with projected increases in population,
economic growth, and goods movement.
    The direct PM2.5 reductions are achieved primarily from
open burning and residential wood combustion control measures. These
types of control measures present special implementation challenges
(e.g., the large number of individuals subject to regulation and the
difficulty of applying conventional technological control solutions).
NOX reductions come largely from District rules for fuel
combustion sources, and from the State's mobile source rules. VOC
reductions come from District rules governing the petroleum industry,
as well as consumer products rules at both the State and local level.
SOX reductions identified in the plan come from District
rules such as RECLAIM, and State measures related to ships.
    Because of the necessity of obtaining additional emissions
reductions from these source categories in the South Coast
nonattainment area and the need to conduct significant public outreach
if applicable control approaches are to be effective, EPA agrees with
the District and CARB that the South Coast 2007 AQMP reflects
expeditious implementation of the programs during the 2008-2014 time
frame. EPA also agrees that the implementation schedule for enhanced
stationary source controls is expeditious, taking into account the time
necessary for purchase and installation of the required control
technologies. The District's control strategies are discussed in
greater detail in Chapter 4 of the South Coast 2007 AQMP, and in
section V.B.2 above.
    In addition, the State has adopted standards for many categories of
on-road and off-road vehicles and engines, gasoline and diesel fuels,
as well as improvements to California's vehicle inspection and
maintenance program, and programs requiring the retrofitting and
replacement of in-use trucks, buses, and off-road equipment. The State
is implementing these rules and programs as expeditiously as
practicable, and it is not feasible to accelerate the schedule for new
emissions standards under the State and Federal mobile source control
programs.
    EPA also expects that CARB and the District will continue to
investigate opportunities to accelerate progress as new control
opportunities arise, and that the agencies will promptly adopt and
expeditiously implement any new measures found to be feasible in the
future.
    As discussed in section V.B.3 above, we are proposing to approve
the RACM/RACT demonstration in the South Coast 2007 AQMP. As discussed
below in section V.C.6., we are also proposing to approve the
attainment demonstration in the SIP. Based on these proposed approvals,
EPA is proposing to grant an extension of the attainment date for the
1997 PM2.5 standards in the South Coast to April 5, 2015
pursuant to CAA section 172(b)(2) and 40 CFR 51.1004(b).
5. Attainment Demonstration
    Table 7 below summarizes the reductions that are relied on in the
South Coast 2007 AQMP to demonstrate attainment by April 5, 2015.

Table 7--Summary of Emissions Reduction Progress for South Coast's PM2.5 Attainment Demonstration (Tons per Day,
                                            tpd), Updated April 2011
----------------------------------------------------------------------------------------------------------------
                                                        NOX             VOC        Direct PM2.5         SOX
----------------------------------------------------------------------------------------------------------------
2002 baseline (2011 SIP Revision, p. 9..........            1093             844              99              53
2014 attainment targets (ARB staff Report for                460             474              86              20
 South Coast 2007 AQMP) *.......................
2014 baseline (2011 SIP Revision, Appendix E, p.             589             518              95              61
 2) **..........................................
2014 remaining emissions after ``adopted                     530             485              87              20
 controls'' (2011 SIP Revision, Appendix E, p.
 2) ***.........................................
Remaining emissions reduction/enforceable               70 (11%)         11 (3%)          1 (8%)            0 0%
 commitment ****................................
----------------------------------------------------------------------------------------------------------------
* The attainment targets have not changed from the November 22, 2010 proposal.
** The 2014 baseline is revised to reflect new estimates which take into account the impact of the economic
  recession on and changes in inventory methodologies for diesel trucks, goods movement and construction
  equipment. See 2011 Progress Report, Appendix E, page 2, ``South Coast Air Basin 2014 Progress to Date on ARB
  Rules'' table, ``New 2014 Baseline'' numbers.
*** The 2014 remaining emissions number is what remains after crediting the reductions from ``adopted
  controls.'' By ``adopted controls'' we mean State or district control measures that EPA has approved or
  proposed to approve into the SIP, or state mobile source measures that are subject to a CAA section 209
  waiver. See section V.B.2.b of this notice. In separate actions, EPA has recently proposed to approve several
  of the measures listed in the 2011 Progress Report SIP Revision, Appendix E tables (e.g., CARB's diesel truck
  rules and the Ocean-going Vessels fuel rule).
**** This row reflects the State's aggregate emissions reduction commitment, including the 10 tpd NOX federal
  assignment. See 2011 Progress Report, p. 5.

    As shown in this table, the majority of the emissions reductions
that the State projects are needed for PM2.5 attainment in
the South Coast by April 5, 2015 come from baseline reductions. These
baseline reductions include not only the benefit of numerous adopted
District and State measures which generally have been approved by EPA
either through the SIP process or the CAA section 209 waiver process
but also the effect of the recent economic recession and revised
emission factors and activity data on projected future inventories. See
2011 Progress Report, Appendix E and Appendices A and B of the TSD. The
remaining reductions needed for attainment are to be achieved by the
District's and CARB's commitments to reduce emissions in the South
Coast nonattainment area. Since the submittal of the South Coast 2007
AQMP and the 2007 State Strategy, SCAQMD and CARB have adopted measures
(summarized in Table 8 below) that can be credited towards reducing the
aggregate emissions reductions in the enforceable commitments.
a. Enforceable Commitments
    As shown above, measures already adopted by the District and CARB
(both prior to and as part of the South Coast 2007 AQMP) provide the
majority of emissions reductions the State projects are needed to
demonstrate attainment. The balance of the needed reductions is in the
form of enforceable commitments by the District and CARB.
    The CAA allows approval of enforceable commitments that are limited
in scope where circumstances exist that warrant the use of such
commitments in place of adopted

measures.\31\ Once EPA determines that circumstances warrant
consideration of an enforceable commitment, EPA considers three factors
in determining whether to approve the CAA requirement that relies on
the enforceable commitment: (a) Does the commitment address a limited
portion of the CAA requirement; (b) is the state capable of fulfilling
its commitment; and (c) is the commitment for a reasonable and
appropriate period of time.\32\
---------------------------------------------------------------------------

    \31\ Commitments approved by EPA under section 110(k)(3) of the
CAA are enforceable by EPA and citizens under, respectively,
sections 113 and 304 of the CAA. In the past, EPA has approved
enforceable commitments and courts have enforced these actions
against states that failed to comply with those commitments: See,
e.g., American Lung Ass'n of N.J. v. Kean, 670 F. Supp. 1285 (D.N.J.
1987), aff'd, 871 F.2d 319 (3rd Cir. 1989); NRDC, Inc. v. N.Y. State
Dept. of Env. Cons., 668 F. Supp. 848 (S.D.N.Y. 1987); Citizens for
a Better Env't v. Deukmejian, 731 F. Supp. 1448, recon. granted in
par, 746 F. Supp. 976 (N.D. Cal. 1990); Coalition for Clean Air v.
South Coast Air Quality Mgt. Dist., No. CV 97-6916-HLH, (C.D. Cal.
Aug. 27, 1999). Further, if a state fails to meet its commitments,
EPA could make a finding of failure to implement the SIP under CAA
Section 179(a), which starts an 18-month period for the State to
correct the non-implementation before mandatory sanctions are
imposed. CAA section 110(a)(2)(A) provides that each SIP ``shall
include enforceable emission limitations and other control measures,
means or techniques * * * as well as schedules and timetables for
compliance, as may be necessary or appropriate to meet the
applicable requirement of the Act.'' Section 172(c)(6) of the Act,
which applies to nonattainment SIPs, is virtually identical to
section 110(a)(2)(A). The language in these sections of the CAA is
quite broad, allowing a SIP to contain any ``means or techniques''
that EPA determines are ``necessary or appropriate'' to meet CAA
requirements, such that the area will attain as expeditiously as
practicable, but no later than the designated date. Furthermore, the
express allowance for ``schedules and timetables'' demonstrates that
Congress understood that all required controls might not have to be
in place before a SIP could be fully approved.
    \32\ The U.S. Court of Appeals for the Fifth Circuit upheld
EPA's interpretation of CAA sections 110(a)(2)(A) and 172(c)(6) and
the Agency's use and application of the three factor test in
approving enforceable commitments in the 1-hour ozone SIP for
Houston-Galveston. BCCA Appeal Group et al. v. EPA et al., 355 F.3d
817 (5th Cir. 2003).
---------------------------------------------------------------------------

    With respect to the South Coast 2007 AQMP and 2007 State Strategy,
circumstances warrant the consideration of enforceable commitments as
part of the attainment demonstration for the South Coast nonattainment
area. As shown in Table 7 above, the majority of emission reductions
that are needed to demonstrate attainment and RFP in the South Coast
nonattainment area come from rules and regulations that were adopted
prior to the AQMP's submittal in November 2007, i.e., they come from
the baseline measures.
    As a result of these already-adopted State and District measures,
most sources in the South Coast nonattainment area were already subject
to stringent rules prior to the development of the 2007 State Strategy
and the South Coast 2007 AQMP, leaving fewer and more technologically
challenging opportunities to reduce emissions. In the South Coast 2007
AQMP and the 2009 revisions to the 2007 State Strategy, the District
and CARB identified potential control measures that could achieve the
additional emissions reductions needed for attainment. However, the
timeline needed to develop, adopt, and implement these measures went
well beyond the April 5, 2008 \33\ CAA deadline to submit the
PM2.5 plan. As discussed above and below, since 2007, the
District and State have made progress in adopting measures to meet
their commitments, but have not yet completely fulfilled them. Given
these circumstances, the 2007 AQMP and the 2007 State Strategy's
reliance on enforceable commitments is warranted. We now consider the
three factors EPA uses to determine whether the use of enforceable
commitments in lieu of adopted measures to meet CAA planning
requirements is approvable.
---------------------------------------------------------------------------

    \33\ The 2007 State Strategy and the South Coast 2007 AQMP were
developed to address both the 1997 PM2.5 NAAQS and the
1997 8-hour ozone NAAQS. The 8-hour ozone SIPs were due in November
2007, and the development and adoption of these plans was timed to
coordinate with this submittal date. 2007 State Strategy, p. 1, and
South Coast 2007 AQMP, p. ES-3.
---------------------------------------------------------------------------

i. The Commitment Represents a Limited Portion of Required Reductions
    For the first factor, we look to see if the commitment addresses a
limited portion of a statutory requirement, such as the amount of
emissions reductions needed in a nonattainment area.
    As shown in Table 7, the remaining portion of the enforceable
commitments in the South Coast 2007 AQMP and the revised 2007 State
Strategy are 70 tpd NOX, 11 tpd VOC and 1 tpd direct
PM2.5 after accounting for measures that are either approved
or proposed for approval and revisions to the future year baseline
inventories resulting from changes to the plan's economic forecasts and
other factors. When compared to the total reductions needed by 2014 for
PM2.5 attainment in the South Coast nonattainment area on a
per-pollutant basis, these remaining commitments represent
approximately 11 percent of the NOX reductions, 3 percent of
the VOC reductions and 8 percent of the direct PM2.5
reductions needed to attain the 1997 PM2.5 standards in the
South Coast nonattainment area.
    We find that the reductions remaining as enforceable commitments in
the 2007 AQMP and the 2007 State Strategy represent a limited portion
of the total emissions reductions needed to meet the statutory
requirement for attainment in the South Coast nonattainment area and
therefore satisfy the first factor. Overall, the level of reductions
remaining as commitments is approximately within the 10 percent range
that EPA has historically accepted in approving attainment
demonstrations.\34\
---------------------------------------------------------------------------

    \34\ See, for example, our approval of the SJV PM10
Plan at 69 FR 30005 (May 26, 2004), the SJV 1-hour ozone plan at 75
FR 10420 (March 8, 2010), and the Houston-Galveston 1-hour ozone
plan at 66 FR 57160 (November 14, 2001).
---------------------------------------------------------------------------

ii. The State is Capable of Fulfilling Its Commitment
    For the second factor, we consider whether the State and District
are capable of fulfilling their commitments. As discussed above, CARB
has adopted and submitted a 2009 State Strategy Status Report and a
2011 Progress Report, which update and revise the 2007 State Strategy.
These reports show that CARB has made significant progress in meeting
its enforceable commitments for the South Coast and several other
nonattainment areas in California. Additional ongoing programs that
address locomotives, recreational boats, and other measures have yet to
be quantified but are expected to reduce NOX and direct
PM2.5 emissions in the South Coast by 2014. See 2011
Progress Report, Appendix E, page 2.
    The District has already exceeded its commitment for reducing VOC
and SOX emissions and is working to meet the commitment to
reduce NOX and directly emitted PM2.5. See Tables
2 and 3. The District is also continuing to work to identify and adopt
additional measures that will reduce emissions.
    Beyond the rules discussed above, both CARB and the District have
well-funded incentive grant programs to reduce emissions from the on-
and off-road engine fleets. Reductions from several of these programs
have yet to be quantified and/or credited in the attainment
demonstration. Finally, we note that the South Coast has experienced
significant improvements in its PM2.5 air quality in the
past few years.
    Given the evidence of the State's and District's efforts to date
and their continuing efforts to reduce emissions, we find that the
State and District are capable of meeting their enforceable commitments
to achieve the necessary reductions needed to attain the 1997
PM2.5 standards in the South Coast nonattainment area by its
proposed attainment date of April 5, 2015.

iii. The Commitment is for a Reasonable and Appropriate Period of Time
    For the third and final factor, we consider whether the commitment
is for a reasonable and appropriate period of time.
    In order to meet the commitments to reduce emissions to the levels
needed to attain the 1997 PM2.5 standards in the South Coast
nonattainment area, the South Coast 2007 AQMP and the 2007 State
Strategy included ambitious rule development, adoption, and
implementation schedules, which both the District and CARB have
substantially met. See 2011 Progress Report, p. 9. EPA considers these
schedules to provide sufficient time to achieve by 2014 the few
remaining reductions needed to attain by the proposed attainment date
of April 5, 2015. We, therefore, conclude that the third factor is
satisfied.
b. Federal Reductions
    As discussed in our November 2010 proposal and as shown in Table 7,
the South Coast 2007 AQMP assigns 10 tons per day of NOX
reductions to the Federal government. However, because the CAA does not
authorize a State to assign responsibility to the Federal government
for meeting SIP requirements, we cannot accept the 10 tpd
NOX emissions reductions emissions reductions the District
and State assigned to the Federal government in the South Coast 2007
AQMP.
    The District has further addressed the federal assignment by
committing to an additional reduction of 1 tpd NOX (see 2011
Progress Report, Appendix F, p. 5 and SCAQMD Governing Board Resolution
11-9, March 4, 2011). In addition, CARB has committed to achieve the
remaining portion of the federal assignment in the 2011 Progress Report
and includes it in the remaining commitment of 70 tpd of
NOX. (See 2011 Progress Report, p. 5, and CARB Executive
Order S-11-010.) As we stated in our November 2010 proposal, we are not
accepting the 10 tpd NOX federal assignment as the CAA does
not allow for such assignment. We are proposing, however, to approve
the State's and District's commitments to achieve the emissions
reductions previously attributed to the federal government.
6. Proposed Action on the Attainment Demonstration
    In order to approve a SIP's attainment demonstration, EPA must make
several findings and approve the plan's proposed attainment date.
    First, we must find that the demonstration's technical bases,
including the emissions inventories and air quality modeling, are
adequate. As discussed above in section V.A and V.C.2, we are proposing
to approve both the emissions inventories and the air quality modeling
on which the South Coast 2007 AQMP's attainment demonstration and other
provisions are based.
    Second, we must find that the SIP submittal provides for
expeditious attainment through the implementation of all RACM and RACT.
As discussed above in section V.B, we are proposing to approve the
RACM/RACT demonstration in the South Coast 2007 AQMP.
    Third, EPA must find that the emissions reductions that are relied
on for attainment are creditable. As discussed in section V.C.5, the
South Coast 2007 AQMP relies principally on adopted and approved/waived
rules to achieve the emissions reductions needed to attain the 1997
PM2.5 standards in the South Coast nonattainment area by
April 5, 2015. The balance of the reductions is currently in the form
of enforceable commitments that account for 11% of the NOX,
8% of the direct PM2.5, and 3% of the VOC emission
reductions needed from 2002 levels for attainment. See Table 7.
    EPA has previously accepted enforceable commitments in lieu of
adopted control measures in attainment demonstrations when
circumstances warrant it and the commitments meet three criteria. As
discussed above in section V.C.5, we find that circumstances here
warrant the consideration of enforceable commitments and that the three
criteria are met: (1) Both the State and the District have demonstrated
their capability to meet their commitments, (2) the commitments
constitute a limited portion of the required emissions reductions, and
(3) the commitments are for an appropriate timeframe. Based on these
conclusions, we propose to allow the State to rely on these limited
enforceable commitments in its attainment demonstration.
    Finally, for a PM2.5 nonattainment area that cannot
attain within five years of its designation as nonattainment, EPA must
grant an extension of the attainment date in order to approve the
attainment demonstration for the area. As discussed above in section
V.C.4, we propose to determine that a five-year extension of the
attainment date is appropriate given the nonattainment problem in the
South Coast nonattainment area and the availability and feasibility of
control measures and, therefore, to grant the State's request to extend
the attainment date in the South Coast nonattainment area to April 5,
2015. For the foregoing reasons, we are proposing to approve the
attainment demonstration in the South Coast 2007 AQMP.

D. Reasonable Further Progress Demonstration

1. Requirements for Reasonable Further Progress
    CAA Section 172(c)(2) requires that plans for nonattainment areas
shall provide for reasonable further progress (RFP). RFP is defined in
section 171(1) as ``such annual incremental reductions in emissions of
the relevant air pollutant as are required by this part or may
reasonably be required by the Administrator for the purpose of ensuring
attainment of the applicable [NAAQS] by the applicable date.''
    The PM2.5 implementation rule requires submittal of an
RFP plan at the same time as the attainment demonstration for any area
for which the State seeks an extension of the attainment date beyond
2010. For areas for which the state requests an attainment date
extension to 2015, such as the South Coast nonattainment area, the RFP
plan must demonstrate that in the applicable milestone years of 2009
and 2012, emissions in the area will be at a level consistent with
generally linear progress in reducing emissions between the base year
and the attainment year. 40 CFR 51.1009(d). States may demonstrate this
by showing that emissions for each milestone year are roughly
equivalent to benchmark emission levels for direct PM2.5
emissions and each PM2.5 attainment plan precursor addressed
in the attainment plan. The steps for determining the benchmark
emissions levels to demonstrate generally linear progress are given in
the PM2.5 implementation rule in 40 CFR 51.1009(f).
    The RFP plan must describe the control measures that provide for
meeting the reasonable further progress milestones for the area, the
timing of implementation of those measures, and the expected reductions
in emissions of direct PM2.5 and PM2.5 attainment
plan precursors. 40 CFR 51.1009(c).
2. Reasonable Further Progress Demonstration in the South Coast 2007
AQMP
    CARB provided an updated and revised RFP demonstration for the
South Coast nonattainment area in Appendix C of the 2011 Progress
Report.

The demonstration addresses direct PM2.5, NOX,
VOC and SOX and uses the 2002 annual average day inventory
as the base year inventory and 2014 as the attainment year. The revised
South Coast PM2.5 RFP demonstration is summarized Table 8
below.
    As discussed above, the District's modeling demonstration indicated
that for attainment of the 1997 PM2.5 NAAQS, SOX
reductions are the most effective, followed by direct PM2.5,
and then NOX and VOC. Therefore, the District's proposed
control strategy maximizes reductions of direct PM2.5 and
SOX to the extent possible.

                                        Table 8--Revised RFP Calculations
                                          [Tons per average annual day]
----------------------------------------------------------------------------------------------------------------
                                                        NOX             VOC        Direct PM2.5         SOX
----------------------------------------------------------------------------------------------------------------
2002 baseline inventory (tpd)...................            1093             844              99              53
Annual percentage change needed to show linear              4.87             3.7            1.01            5.35
 progress (%)...................................
Annual emissions reduction representing 1 year's            52.8            30.8             1.1             2.8
 worth of RFP...................................
----------------------------------------------------------------------------------------------------------------
                                                      2009
----------------------------------------------------------------------------------------------------------------
Benchmark emissions level (tpd).................             724             628              91              34
Revised projected controlled level (tpd)........             677             563              89              43
Emissions above/below benchmark emissions level              -47             -65              -2               9
 (tpd)\a\.......................................
Percent above/below benchmark emissions level...             -6%            -10%             -2%            +26%
----------------------------------------------------------------------------------------------------------------
                                                      2012
----------------------------------------------------------------------------------------------------------------
Benchmark emissions level (tpd).................             566             534              88              26
Revised projected controlled emissions level                 582             514              89              26