[Federal Register Volume 81, Number 238 (Monday, December 12, 2016)]
[Proposed Rules]
[Pages 89407-89418]
[FR Doc No: 2016-29758]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R09-OAR-2016-0660; FRL-9956-27-Region 9]

Approval of California Air Plan; Owens Valley Serious Area Plan
for the 1987 24-Hour PM10 Standard

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
approve a state implementation plan (SIP) revision submitted by the
State of California and Great Basin Unified Air Pollution Control
District (GBUAPCD or ``District'') to meet Clean Air Act (CAA or
``Act'') requirements applicable to the Owens Valley PM10
nonattainment area (NA). The Owens Valley PM10 NA is located
in the southern portion of the Owens Valley in Inyo County, California.
It is classified as a Serious nonattainment area for the national
ambient air quality standards (NAAQS) for particulate matter of ten
microns or less (PM10). The submitted SIP revision is the
``Great Basin Unified Air Pollution Control District 2016 Owens Valley
Planning Area PM10 State Implementation Plan'' (``2016
PM10 Plan'' or ``Plan''). The GBUAPCD's obligation to submit
the 2016 PM10 Plan was triggered by the EPA's 2007 finding
that the Owens Valley PM10 NA had failed to meet its
December 31, 2006, deadline to attain the PM10 NAAQS. The
CAA requires a Serious PM10 nonattainment area that fails to
meet its attainment deadline to submit a plan providing for attainment
of the PM10 NAAQS and for an annual emission reduction in
PM10 of not less than five percent until attainment of the
PM10 NAAQS. The EPA is proposing to approve the 2016
PM10 Plan as meeting all relevant statutory and regulatory
requirements.

DATES: Any comments on this proposal must arrive by January 11, 2017.

ADDRESSES: Submit comments, identified by docket number EPA-R09-OAR-
2016-0660, at http://www.regualtions.gov, or via email to
<EMAIL_ADDRESS>For comments submitted at Regulations.gov,
follow the online instructions for submitting comments. Once submitted,
comments cannot be edited or removed from Regulations.gov. For either
manner of submission, the EPA may publish any comment received to its
public docket. Do not submit electronically any information you
consider to be Confidential Business Information (CBI) or other
information whose disclosure is restricted by statute. Multimedia

submissions (audio, video, etc.) must be accompanied by a written
comment. The written comment is considered the official comment and
should include discussion of all points you wish to make. The EPA will
generally not consider comments or comment contents located outside of
the primary submission (i.e., on the Web, cloud, or other file sharing
system). For additional submission methods, please contact the person
identified in the FOR FURTHER INFORMATION CONTACT section. For the
EPA's full public comment policy, information about CBI or multimedia
submissions, and general guidance on making effective comments, please
visit http://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Ginger Vagenas, EPA Region IX, 415-
972-3964<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION: Throughout this document, the terms ``we,''
``us,'' and ``our'' mean EPA.

Table of Contents

I. Background: PM10 Air Quality Planning in the Owens
Valley PM10 Nonattainment Area
    A. Planning History
    B. Description of the Owens Valley PM10 Nonattainment
Area
    C. Public Notice, Public Hearing, and Completeness Requirements
for SIP Submittals
    D. CAA Requirements for PM10 Serious Area Plans
II. Evaluation of the Owens Valley PM10 Plan's Compliance
With CAA Requirements
    A. Review of the Owens Valley PM10 Nonattainment Area
Emissions Inventories
    B. Demonstration of Attainment
    C. Five Percent Requirement
    D. BACM/BACT and Adopted Control Strategy
    E. Reasonable Further Progress/Quantitative Milestones
    F. Contingency Measures
    G. Transportation Conformity
III. Summary of the EPA's Proposed Action
IV. Statutory and Executive Order Reviews

I. Background: PM10 Air Quality Planning in the Owens Valley
PM10 Nonattainment Area

A. Planning History

    The NAAQS are standards for certain ambient air pollutants set by
the EPA to protect public health and welfare. PM10 is among
the ambient air pollutants for which the EPA has established health-
based standards. By penetrating deep in the lungs, PM10
causes adverse health effects including lung damage, increased
respiratory disease, and premature death. Children, the elderly, and
people with asthma and heart conditions are the most vulnerable.
    On July 1, 1987, the EPA revised the health-based national ambient
air quality standards, replacing the standards for total suspended
particulates with new standards applying only to PM10.\1\ At
that time, the EPA established two PM10 standards, annual
and 24-hour. Effective December 18, 2006, the EPA revoked the annual
PM10 standard but retained the 24-hour PM10
standard.\2\ The 24-hour PM10 standard of 150 micrograms per
cubic meter ([mu]g/m\3\) is attained when the expected number of days
with a 24-hour average concentration above 150 [mu]g/m\3\ per calendar
year averaged over a three-year period, as determined in accordance
with appendix K to 40 CFR part 50, is equal to or less than one.\3\
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    \1\ 52 FR 24672.
    \2\ 71 FR 61144 (October 17, 2006).
    \3\ 40 CFR 50.6 and 40 CFR part 50, appendix K.
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    On the date of enactment of the 1990 CAA Amendments, the Owens
Valley (along with many other areas meeting the qualifications of
section 107(d)(4)(B) of the amended Act) was designated nonattainment
by operation of law.\4\ The Owens Valley PM10 NA is located
in Inyo County in east-central California. The EPA codified the
boundaries of the Owens Valley PM10 NA at 40 CFR 81.305.
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    \4\ 56 FR 11101 (March 15, 1991).
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    Once an area is designated nonattainment for PM10,
section 188 of the CAA outlines the process for classifying the area as
Moderate or Serious and establishes the area's attainment deadline. In
accordance with section 188(a), at the time of designation, all
PM10 nonattainment areas, including the Owens Valley
PM10 NA, were initially classified as Moderate. A Moderate
PM10 nonattainment area can subsequently be reclassified as
Serious either before the applicable attainment date if the EPA
determines the area cannot practicably attain the PM10 NAAQS
by this attainment date, or after the passage of the applicable
Moderate area PM10 attainment date if the EPA determines
that the area has failed to attain the standard. In accordance with
section 188(b)(1) of the CAA, on February 8, 1993, the EPA determined
the Owens Valley PM10 NA could not practicably attain the
PM10 NAAQS by December 31, 1994 and reclassified the area as
Serious.\5\
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    \5\ 58 FR 3334 (January 8, 1993).
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    As a Serious area, the Owens Valley PM10 NA acquired a
new attainment deadline of no later than December 31, 2001. CAA section
188(c)(2). However, CAA section 188(e) authorizes the EPA to grant up
to a 5-year extension of that attainment deadline if certain conditions
are met by the state. In order to obtain the extension, the state must
make a SIP submission showing that: (1) Attainment by the applicable
attainment date would be impracticable; (2) the state complied with all
requirements and commitments pertaining to the area in the
implementation plan for the area; and (3) the plan for the area
includes the most stringent measures (MSM) that are included in the
implementation plan of any state or are achieved in practice in any
state and can feasibly be implemented in the specific area.
    In its 1998 Owens Valley PM10 Plan (submitted to the EPA
on September 10, 1998), California requested an attainment date
extension under CAA section 188(e) for the Owens Valley PM10
NA from December 31, 2001 to December 31, 2006. On September 3, 1999,
the EPA approved the Serious area 1998 PM10 Plan for the
Owens Valley PM10 NA as meeting the requirements for such
areas in CAA sections 189(b) and (c), including the requirements for
implementation of best available control measures (BACM) in section
189(b)(1)(B) and MSM in section 188(e). In the same action, the EPA
approved the submission with respect to the requirements of section
188(e) and granted California's request to extend the attainment date
for the area to December 31, 2006. This final action and the proposal
preceding it provide a more detailed discussion of the history of
PM10 planning in the Owens Valley PM10 NA.\6\
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    \6\ See 64 FR 34173 (June 25, 1999) and 64 FR 48305 (September
3, 1999).
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    On June 6, 2007, the EPA found that the Owens Valley
PM10 NA failed to attain the 24-hour PM10 NAAQS
by the applicable attainment date of December 31, 2006.\7\ Accordingly,
the State was required to submit a new plan meeting the requirements of
section 189(d) by December 31, 2007.
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    \7\ 72 FR 31183.
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    The Governing Board of the GBUAPCD adopted the ``2008 Owens Valley
PM10 Planning Area Demonstration of Attainment State
Implementation Plan'' (``2008 Plan'') on February 1, 2008. The 2008
Plan, which included a request for an attainment date extension, was
submitted by the State to the EPA on June 11, 2009. The 2008 Plan was
subsequently updated and superseded by the submittal of the 2016
PM10 Plan, which reiterates the request for an attainment
date extension and incorporates agreements reached between the GBUAPCD
and the City of

Los Angeles, and is the subject of this action.\8\
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    \8\ See Chapter 8 of the 2016 PM10 Plan and letter
from Phillip L. Kiddoo, Air Pollution Control Officer, GBUAPCD to
Elizabeth Adams, Acting Air Division Director, U.S. EPA, Region 9,
dated October 26, 2016.
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B. Description of the Owens Valley PM10 Nonattainment Area

    Owens Lake is located in Inyo County in east central California in
the southern portion of the Owens Valley. It is part of a chain of
lakes formed over 140,000 thousand years ago.\9\ In 1913, the Los
Angeles Department of Water and Power (LADWP) completed an aqueduct
system and began diverting the waters of the Owens River to the City of
Los Angeles. By 1930, these diversions from the Owens River had drained
the Owens Lake almost completely dry.\10\
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    \9\ 2016 PM10 Plan, p. 7.
    \10\ Id., p. 8.
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    Strong winds blowing over the surface of the dry, alkaline bed of
the Owens Lake have produced among the highest measured concentrations
of PM10 ever recorded, including a monitored reading that
exceeded 12,000 [mu]g/m\3\--more than 80 times over the federal 24-hour
standard.\11\ Past data from the EPA's approval of the 1998
PM10 Plan indicated that during days when violations were
recorded, 94 percent of the PM10 concentrations came from
the Owens Lake bed and another five percent came from re-entrained
Owens Lake dust already deposited in the area.\12\ Since our approval
of the 1998 PM10 Plan, PM10 emissions occurring
directly from the Owens Lake bed and those attributable to re-entrained
Owens Lake dust deposited in the two-kilometer area surrounding the
Owens Lake bed, particularly the Keeler and Olancha Dunes, have
declined. Despite this reduction, the predominant source of
PM10 emissions contributing to nonattainment in the Owens
Valley PM10 NA continues to be the dry Owens Lake bed and
the two-kilometer perimeter surrounding it.\13\
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    \11\ Id., p. S-2.
    \12\ 64 FR 34173 at 34174.
    \13\ 2016 PM10 Plan, page S-4, Table S-2, and Chapter
8.
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    Approximately 40,000 permanent residents live in the area affected
by the Owens Lake PM10 emissions.\14\ Some of these
residents are members of four Tribes: The Lone Pine Paiute/Shoshone
Tribe, the Fort Independence Tribe, the Big Pine Tribe, and the Bishop
Tribe. Residents and visitors to the area suffer the adverse health
effects from high PM10 concentrations.\15\
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    \14\ Id. at S-2.
    \15\ Id.
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    As noted previously, the State of California and the GBUAPCD
submitted a PM10 Plan in 1998 that the EPA approved in
1999.\16\ The EPA recognized in approving the 1998 PM10 Plan
that the Owens Valley PM10 NA presented one of the most
challenging air quality problems nationally, requiring a reduction of
PM10 concentrations from almost 4000 [mu]g/m\3\ to the 24-
hour NAAQS of 150 [mu]g/m\3\. The EPA also recognized that while the
origin of the PM10 problem was well understood--the draining
of Owens Lake by the City of Los Angeles in the early part of this
century and continued LADWP withdrawals from the Owens River--the
solution to the problem remained controversial.\17\ The EPA's
evaluation of the 1998 PM10 Plan noted the unique
complexities of the Owens Valley PM10 planning process,
including the competing authorities and responsibilities of the GBUAPCD
to protect Owens Valley residents from the harmful effects of air
pollution and those of the City of Los Angeles to provide its residents
with an adequate water supply.\18\
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    \16\ 64 FR 48305.
    \17\ 64 FR 34173 at 34174.
    \18\ Id.
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    Historically, there have been significant disputes between the
GBUAPCD and the City of Los Angeles concerning the appropriateness,
location, and extent of control measures to reduce PM10
emissions from the Owens Lake bed and surrounding areas, which
interfered with the adoption of a fully approvable plan. The legal
history between the GBUAPCD and the City of Los Angeles is described in
some detail in the EPA's proposed approval of the 1998 PM10
Plan and in the 2016 PM10 Plan.\19\ In summary, California
legislation followed by litigation in state and federal courts resulted
in a series of agreements requiring the City of Los Angeles to
implement a variety of control measures to mitigate PM10
emissions from the dry Owens Lake bed. The most recent iteration of
these agreements, reached after extensive negotiations, is the 2014
Stipulated Judgment between the City of Los Angeles and the
GBUAPCD.\20\ It is our understanding that the 2014 Stipulated Judgment
resolves all disputes between the District and the City of Los Angeles
and it appears to clearly articulate the responsibilities of both
parties, providing certainty and eliminating the risk of further
litigation regarding the Owens Lake bed controls required for
attainment and contingency measures. The 2014 Stipulated Judgment adds
to and incorporates prior agreements between the parties and
constitutes the foundation for the 2016 PM10 Plan that we
are proposing to approve in this action.\21\
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    \19\ 2016 PM10 Plan, pp. 9-12.
    \20\ Id., Appendix II-1.
    \21\ Id., p.12 (``The judgment requires the City of Los Angeles
to implement the dust control measures ordered in 2011 and 2012 and
provides for additional dust control measures up to 53.4 square
miles in total for all ordered dust control areas.'')
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    The EPA is proposing to approve the 2016 PM10 Plan
because it meets the CAA requirements for Serious area plans. As was
true of the 1998 PM10 Plan, this 2016 PM10 Plan
is an important blueprint for clean air in one of the most unique and
challenging PM10 nonattainment areas in the United
States.\22\ Successful implementation will require continued joint
efforts by the GBUAPCD and the City of Los Angeles.\23\
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    \22\ In 2016, the EPA bestowed its Clean Air Excellence Award
for Regulatory and Policy Innovations on the GBUAPCD in recognition
of the District's development of leading methods to identify
pollution source areas, analyze particulate emissions, and determine
suitable pollution control measures. The EPA noted the Owens Lake
project constitutes the world's largest PM10 emission
control project and has led to annual air pollution reductions of
75,000 tons. See the EPA's Web site: https://www.epa.gov/caaac/clean-air-excellence-awards.
    \23\ In 2016, the EPA bestowed its Clean Air Excellence Award
for Regulatory and Policy Innovations on the GBUAPCD in recognition
of the District's development of leading methods to identify
pollution source areas, analyze particulate emissions, and determine
suitable pollution control measures. The EPA noted the Owens Lake
project constitutes the world's largest PM10 emission
control project and has led to annual air pollution reductions of
75,000 tons. See the EPA's Web site: https://www.epa.gov/caaac/clean-air-excellence-awards.
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    The establishment of controls on the lake bed has resulted in
significant improvements to air quality in the Owens Valley. Between
1993 and 2014, the number of NAAQS exceedances decreased substantially
at monitors located in the Owens Valley PM10 NA. For
example, the peak three-year average number of exceedances at the Dirty
Socks monitor declined from 41 to 9 in 2014, at the Keeler monitor from
20 to 8, and at the Shell Cut monitor from 19 to 5.\24\ As shown in
Table 1, the 2016 PM10 Plan demonstrates that
PM10 design concentrations are predicted to be below the
NAAQS when all required controls are implemented by the City of Los
Angeles and the GBUAPCD.\25\ Through the continued efforts of the
GBUAPCD and the City of Los Angeles, the 2016 PM10 Plan
demonstrates attainment of the 24-hour PM10 NAAQS within the
attainment year of 2017.
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    \24\ 2016 PM10 Plan, Appendix III-2, Table 1.
    \25\ Id., Table 7-5.

                              Table 1--Decline in Owens Valley PM10 Concentrations
                                                  [[mu]g/m\3\]
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                                                                                Hybrid model 2017
                        Monitoring site                           July 2009-June 2014      design concentration
                                                                      maximum PM10             predictions
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Dirty Socks...................................................                    1,437                       93
Flat Rock.....................................................                      871                       94
Keeler........................................................                    2,994                       67
Lizard Tail...................................................                    4,571                      142
Mill Site.....................................................                      754                      125
North Beach...................................................                    1,536                       67
Olancha.......................................................                      779                       41
Shell Cut.....................................................                    2,149                      105
Stanley.......................................................                      286                       39
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Source: 2016 PM10 Plan, Tables 7-1 and 7-5.

C. Public Notice, Public Hearing, and Completeness Requirements for SIP
Submittals

    CAA section 110(a)(1) and (2) and 110(l) require each state to
provide reasonable public notice and opportunity for public hearing
prior to the adoption and submission of a SIP or SIP revision to the
EPA. To meet this requirement, every SIP submission should include
evidence that adequate public notice was given and an opportunity for a
public hearing was provided consistent with the EPA's implementing
regulations in 40 CFR 51.102.
    Both the GBUAPCD and the California Air Resources Board (CARB)
satisfied applicable statutory and regulatory requirements for
reasonable public notice and hearing prior to adoption of the 2016
PM10 Plan. The District provided a public comment period and
conducted a public hearing on April 13, 2016, before its Board adopted
the 2016 PM10 Plan.\26\ CARB provided the required public
notice and opportunity for public comment prior to its May 19, 2016
public hearing.\27\ The submission provides proof of publication of
notices for the respective public hearings. We find, therefore, that
the 2016 PM10 Plan meets the procedural requirements for
public notice and hearing in CAA sections 110(a) and 110(l).
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    \26\ Id., Chapter 13--Declaration of Clerk of the Board and
Resolutions Certifying the EIR and Approving the SIP.
    \27\ State of California Air Resources Board Resolution 16-3,
May 19, 2016.
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    CAA section 110(k)(1)(B) requires the EPA to determine whether a
SIP submission is complete within 60 days of receipt. This section of
the CAA also provides that any plan that the EPA has not affirmatively
determined to be complete will become complete by operation of law six
months after the date of submission. The EPA's completeness criteria
are found in 40 CFR part 51, Appendix V. The EPA determined the SIP
submission dated June 9, 2016, to be complete on November 21, 2016.\28\
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    \28\ See letter from Elizabeth Adams, Acting Air Division
Director, U.S. EPA Region 9 to Richard Corey, Executive Officer,
California Air Resource Board.
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D. CAA Requirements for PM10 Serious Area Plans

    As a Serious PM10 nonattainment area that failed to meet
its applicable attainment date of December 31, 2006, the Owens Valley
PM10 NA is subject to CAA sections 188 and 189. Section 188
establishes attainment dates for Serious PM10 nonattainment
areas. However, when an area such as the Owens Valley PM10
NA fails to attain the PM10 NAAQS within the time prescribed
in section 188, a new attainment date may be approved. The new
attainment date is established by section 179(d)(3), which establishes
that the attainment date applicable to the revision required under
paragraph (1) of section 179(d) shall be the same as provided in the
provisions of section 172 of the CAA. That section of the statute
requires the area attain as expeditiously as practicable, but no later
than five years from the date of designation.\29\ It also includes a
provision that allows the EPA to extend the attainment date for up to
an additional five years (i.e., a period of no greater than 10 years)
to the extent the Administrator determines appropriate, considering the
severity of nonattainment and the availability and feasibility of
pollution control measures.\30\
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    \29\ In accordance with CAA section 179(d)(3) and 172(a)(2)(A),
the attainment deadline applicable to an area that misses the
Serious area attainment date is as soon as practicable, but no later
than five years from the publication date of the nonattainment
finding notice. The EPA's finding that the Owens Valley
PM10 NA failed to attain by the Serious area
nonattainment date was published on June 6, 2007.
    \30\ 42 U.S.C. 7502(a)(2)(A). See also Ass'n of Irritated
Residents v. United States EPA, 423 F.3d 989, 993-94 (9th Cir.
2015).
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    Section 189(d) provides that the state shall submit within 12
months after the applicable attainment date, plan revisions that
provide for attainment of the PM10 air quality standard and,
from the date of such submission until attainment, for an annual
reduction of PM10 or PM10 precursor emissions
within the area of not less than five percent of the amount of such
emissions as reported in the most recent inventory prepared for the
area.
    The general planning and control requirements for all nonattainment
plans are found in CAA sections 110 and 172. More specific planning and
control requirements relevant to the PM10 NAAQS are found in
Part D, Subpart 4, in CAA sections 188 and 189, as noted above. The EPA
has issued a General Preamble \31\ and Addendum to the General Preamble
\32\ to provide guidance to states for meeting the CAA's requirements
for the PM10 NAAQS. The General Preamble mainly addresses
the requirements for moderate nonattainment areas and the Addendum
addresses requirements for Serious nonattainment areas. The EPA has
also issued other guidance documents related to PM10 plans
that are discussed and cited below. The specific PM10 plan
requirements addressed by this proposed action are summarized below.
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    \31\ ``State Implementation Plans; General Preamble for the
Implementation of Title I of the Clean Air Act Amendments of 1990,''
57 FR 13498 (April 16, 1992) (General Preamble) and 57 FR 18070
(April 28, 1992).
    \32\ ``State Implementation Plans for Serious PM10
Nonattainment Areas, and Attainment Date Waivers for PM10
Nonattainment Areas Generally; Addendum to the General Preamble for
the Implementation of Title I of the Clean Air Act Amendments of
1990,'' 59 FR 41998 (August 16, 1994) (Addendum).

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1. Emissions Inventories
    CAA section 172(c)(3) requires that an attainment plan include a
comprehensive, accurate, and current inventory of actual emissions from
all sources of the relevant pollutants.
2. Attainment Demonstration and Five Percent Requirement
    For Serious PM10 nonattainment areas that do not attain
the PM10 NAAQS by the applicable attainment date, CAA
section 189(d) requires the state to submit plan revisions that provide
for attainment of the NAAQS and provide for an annual five percent
reduction in PM10 or PM10 precursor emissions for
each year from the date of submission until attainment.\33\ Section
189(d) specifies that the state must submit these plan revisions within
12 months of the applicable attainment date that the area failed to
meet.
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    \33\ The EPA has previously determined that PM10
precursors are not significant contributors to PM10
levels in the Owens Valley PM10 NA. See 64 FR 34173 at
34716 (June 25, 1999). In that rulemaking notice, the EPA noted that
the contribution from secondary aerosols is insignificant. Inventory
information submitted by the GBUAPCD in association with the 2016
PM10 Plan also demonstrates that precursors do not
contribute significantly to PM10 levels that exceed the
standard. See section II.D.2.b of this notice.
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3. Best Available Control Measures for Sources of PM10
    CAA section 189(b)(1)(B) requires provisions to assure that BACM,
including the best available control technology (BACT) for stationary
sources, for the control of PM10 shall be implemented no
later than four years after the date a nonattainment area is
reclassified as Serious.
    When a Moderate area is reclassified to Serious, the requirements
to implement reasonably available control measures (RACM), 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 (RACT), in CAA sections 172(c)(1) and 189(a)(1)(C)
remain applicable. Thus, a Serious area PM10 plan must also
provide for the implementation of RACM and RACT to the extent that the
RACM and RACT requirements have not been satisfied in the area's
Moderate area plan.
    CAA section 189(e) requires that control requirements applicable to
major stationary sources of PM10 shall also apply to major
stationary sources of PM10 precursors, except where the
Administrator determines that such sources do not contribute
significantly to PM10 levels that exceed the standards in
the area.
4. Reasonable Further Progress and Quantitative Milestones
    CAA section 172(c)(2) requires that implementation plans
demonstrate reasonable further progress (RFP) as defined in section
171(1). Section 171(1) defines RFP as such annual incremental
reductions in emissions of the relevant air pollutant as are required
by part D of title I or may reasonably be required by the Administrator
for the purpose of ensuring attainment of the applicable national
ambient air quality standard by the applicable date. The general RFP
requirement of section 172(c)(2) applies to SIP submissions necessary
to meet CAA section 189(d) for the PM10 NAAQS.
    In addition, CAA section 189(c)(1), which is specifically
applicable to the PM10 NAAQS, requires that an
implementation plan contain quantitative milestones that will be
achieved every three years and that will demonstrate that RFP is being
met.
5. Contingency Measures
    CAA section 172(c)(9) requires that implementation plans provide
for the implementation of specific measures to be undertaken if the
area fails to make RFP or to attain the NAAQS by the attainment date
applicable under part D of title I. Such measures are to take effect in
any such case without further action by the State or the Administrator.
The contingency measure requirement of CAA section 179(c)(9) applies to
the SIP submissions necessary to meet CAA section 189(d) for the
PM10 NAAQS.
6. Transportation Conformity and Motor Vehicle Emissions Budgets
    Transportation conformity is required by CAA section 176(c). Our
conformity rule (40 CFR part 93, subpart A) requires that
transportation plans, programs, and projects conform to state air
quality implementation plans and establishes the criteria and
procedures for determining whether or not they do so. Conformity to a
SIP means that transportation activities will not produce new air
quality violations, worsen existing violations, or delay timely
attainment of the NAAQS or any interim milestone. Once a SIP that
contains motor vehicle emissions budgets has been submitted to the EPA,
and the EPA has found them adequate, these budgets are used for
determining conformity (i.e., emissions from planned transportation
activities must be less than or equal to the budgets).

II. Evaluation of the Owens Valley PM10 Plan's Compliance
With CAA Requirements

A. Review of the Owens Valley PM10 Nonattainment Area Emissions
Inventories

    The 2016 PM10 Plan includes PM10 emissions
inventories for the Owens Valley PM10 NA for the years 1999
through 2019. For the most part, the emissions data presented in the
Plan were derived from the CARB 2012 and 2015 emission inventories for
Inyo County and apportioned to the Owens Valley PM10 NA
using factors such as population, roadway miles, and land area.\34\ The
GBUAPCD calculated fugitive windblown dust emissions using a
combination of modeling and data collected at monitors located around
the Owens Lake bed. The unpaved road dust emissions were calculated
using the GBUAPCD's emission factors. These calculations are included
in Tables 3 and 4 of Appendix IV-1 of the 2016 PM10 Plan.
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    \34\ An overview of the 2016 PM10 Plan emissions
inventory is provided here. For detailed results and a complete
discussion of the methodologies used to produce the emissions
inventories, see the following sections of the 2016 PM10
Plan: Summary, S.1; Chapter 4, ``PM10 Emissions Inventory
and Determination of Significant Sources;'' and Appendix IV-1,
``2016 SIP Inventory.''
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    The District has also provided an inventory of emissions of
PM10 precursors (i.e., sulfur oxides, nitrogen oxides,
volatile organic compounds, and ammonia) for a 2015 exceedance day.\35\
In this inventory, ammonia emission estimates ``were derived from Inyo
County emissions that were queried from the USEPA's 2014 National
Emissions Inventory.'' Estimates for the other precursors ``were
derived from Inyo County emissions that were queried from the CARB
CEPAM Standard Emissions Tool (2013 Almanac).'' In all cases, emissions
were apportioned to the Owens Valley PM10 NA using various
factors.\36\ The EPA previously determined that PM10
precursors are not significant contributors to PM10 levels
in the Owens Valley PM10 NA.\37\ At that time, the EPA noted
that the contribution from secondary aerosols is insignificant. The EPA
proposes to find again that precursors do not play a significant part
in the PM10 problem in the Owens

Valley PM10 NA. We discuss this in more detail in Section
II.D., below.
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    \35\ See attachment to letter from Phillip L. Kiddoo, Air
Pollution Control Officer, GBUAPCD to Elizabeth Adams, Acting Air
Division Director, U.S. EPA, Region 9, dated October 26, 2016.
    \36\ Id. The metrics used to ratio emissions from Inyo County to
the Owens Valley PM10 NA are specified in the attachment.
    \37\ See 64 FR 34173 at 34716 (June 25, 1999).
---------------------------------------------------------------------------

    The emissions inventories provided in the Plan show that fugitive
dust emissions resulting from wind erosion on the exposed Owens Lake
bed, off-lake deposits of lake bed dust such as the Keeler Dunes, and
open desert are by far the largest sources of PM10 in the
Owens Valley PM10 NA. Other, much smaller sources of
windblown dust include small mining facilities and the Lone Pine
Landfill. The remaining sources of PM10 within the Owens
Valley PM10 NA include wood stoves, fireplaces, unpaved and
paved road dust, and vehicle tailpipe emissions. The District also
notes that prescribed burning is a source of PM10 in the
nonattainment area. There are no large industrial sources of
PM10 in the Owens Valley PM10 NA.
    The GBUAPCD also grouped emissions into three location-based
categories: ``lake bed emissions,'' ``near-lake emissions,'' and
``remaining Owens Valley NA emissions.'' Emissions originating from the
lake bed are included in the lake bed category. The near-lake category
consists of emissions generated within a two-kilometer zone surrounding
the lake bed and includes fugitive windblown dust emissions from paved
and unpaved roads and open desert, emissions from other sources within
two kilometers of the lake bed such as the Lone Pine Dump, and the
Keeler and Olancha dunes. Emissions generated outside the two-kilometer
zone are grouped in the remaining Owens Lake NA emissions category. The
``Owens Lake Subarea'' encompasses the lake bed and the near-lake
emissions. Emissions from unpaved roads and open desert areas generated
within the two-kilometer zone surrounding the lake were used in the
District's analysis of which sources contribute significantly to
nonattainment, thereby allowing the District to factor in the impact of
the distance between emission sources and affected monitors.
    Table 2 provides a summary of the annual emissions forecast for all
PM10 emission source categories in the Owens Valley
PM10 NA for 2006, 2007, and for 2016 through 2019 (tons per
year).
---------------------------------------------------------------------------

    \38\ Values presented represent the emissions at the end of the
calendar year, after all scheduled controls are in place.
    \39\ Includes PM10 emissions from Lone Pine Landfill,
which equal on average approximately 60 tons per year.
    \40\ Emissions assumed constant over time.
    \41\ Miscellaneous sources include: Manufacturing and
industrial, service and commercial, mineral processes, metal
processes, residential fuel combustion, construction and demolition,
paved and unpaved road dust (activity related), windblown dust from
agricultural lands, managed burning and disposal, on-road mobile,
and wildfires.

                                                  Table 2--Summary of PM10 Annual Emissions in the OVPA
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        Near-lake emissions            Remaining Owens Valley NA emissions
                                                              ------------------------------------------------------------------------------
                                                    Lake bed                                           Windblown
                  Year end \38\                    emissions      Keeler      Olancha    2-km buffer      dust      Windblown      Misc.        Total
                                                                  Dunes        Dunes      (excluding    unpaved     dust open     sources
                                                                                dunes) \39\     roads     desert \40\      \41\
--------------------------------------------------------------------------------------------------------------------------------------------------------
2006............................................          789        5,324        6,395        4,217          416       19,617          854       37,613
2007............................................        7,448        4,476        5,011        3,143          416       19,617          854       40,964
2016............................................        1,222          172        1,506        1,358          416       19,617          747       25,038
2017............................................          355           41        1,093        1,180          416       19,617          747       23,450
2018............................................          355           41          798        1,053          416       19,617          747       23,027
2019............................................          355           41          586          962          416       19,617          750       22,726
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: 2016 PM10 Plan, Table 4-3.

    The EPA is proposing to find that the 2016 PM10 Plan's
emissions inventories for 2006 through 2019 are comprehensive,
accurate, and current inventories of actual emissions from all sources
in the Owens Valley PM10 NA and that these emissions
inventories meet the requirements of section 172(c)(3) of the CAA and
EPA guidance.\42\ The GBUAPCD has provided a 2006 base year and future
year emissions inventories to 2019, comprehensively addressing all
source categories in the Owens Valley PM10 NA. Consequently,
we are proposing to find that the emissions inventories provided by the
GBUAPCD meet the requirements of section 172(c)(3) and provide an
adequate basis for the attainment demonstration as well as for the BACM
and RFP demonstrations.
---------------------------------------------------------------------------

    \42\ Emissions Inventory Guidance for Implementation of Ozone
and Particulate Matter National Ambient Air Quality Standards
(NAAQS) and Regional Haze Regulations. U.S. EPA, September 29, 2016
(draft).
---------------------------------------------------------------------------

B. Demonstration of Attainment

    The 2016 PM10 Plan must provide a detailed demonstration
(including air quality modeling) that the specified control strategy
will reduce PM10 emissions so that the 24-hour NAAQS will be
attained as soon as practicable but no later than June 6, 2017,
assuming final approval of the attainment deadline extension discussed
above. CAA section 189(b)(1)(A).
1. Attainment Deadline
    In 2007, the EPA notified the GBUAPCD that it had failed to attain
the PM10 NAAQS by the attainment date at the end of
2006.\43\ The GBUAPCD has requested that the EPA extend the attainment
date for the Owens Valley PM10 NA for an additional 10
years.\44\ The EPA is proposing to approve the requested attainment
date extension because, considering the severity of nonattainment and
the availability and feasibility of pollution control measures, the EPA
believes such an extension to June 6, 2017 is warranted based on
various factors, including the following.
---------------------------------------------------------------------------

    \43\ See 72 FR 31183 (June 6, 2007).
    \44\ As discussed above, CAA section 188 and 179 allow up to a
10-year extension of the attainment date after the EPA issues a
finding that a Serious PM10 nonattainment area has failed
to attain the NAAQS. CAA section 172(a) authorizes the EPA to extend
the attainment deadline to the extent it deems appropriate for a
period of no greater than 10 years from the publication of the
nonattainment finding, considering the severity of nonattainment and
the availability and feasibility of pollution control measure.
---------------------------------------------------------------------------

    First, the EPA acknowledges the severity of the PM10
problem. As discussed above, prior to the application of controls, the
Owens Valley PM10 NA experienced dust storms of
unprecedented magnitude that originated from the dry Owens Lake bed
under certain meteorological conditions. The magnitude of these dust
storms from the dry lake bed were unique within California and the
United States.
    Second, the factors creating the dry Owens Lake bed, specifically
the diversion of water in the early 20th century to the City of Los
Angeles, resulted in complex legal and technical

agreements for installation of control measures that were untested in
kind and scope. Since approval of the 1998 PM10 Plan, the
GBUAPCD and City of Los Angeles have worked consistently to refine and
optimize the complex set of control measures leading to substantial
reductions of PM10 from the dry Owens Lake bed and
surrounding near-lake sources. The culmination of decades of work on
this problem by the GBUAPCD and the City of Los Angeles is the
Stipulated Judgment leading to the District's adoption and the EPA's
approval of Rule 433 into the SIP in 2016.\45\ Rule 433 will ensure
that the mitigation measures leading to the final reductions in
PM10 will occur and lead to attainment of the NAAQS.
---------------------------------------------------------------------------

    \45\ Because some of the controls required in the 2016
PM10 Plan are required to be installed prior the end of
2017, this leaves open the possibility that some of the required
controls will not be completed by June of 2017. We do not believe
this will be an impediment to reaching attainment due to the
seasonal nature of PM10 emissions in the Owens Lake NA,
which are generally elevated in the winter and spring months.
---------------------------------------------------------------------------

    For these reasons, the EPA concurs that an extension of the
attainment deadline to June 6, 2017 is warranted.
2. PM10 Attainment Demonstration Approaches
    A key part of a PM10 attainment plan is the attainment
demonstration. This is a demonstration by the state that the existing
and planned emission control measures, in this case, the controls that
have been incorporated into Rule 433 and the Keeler Dunes Project, are
sufficient to result in attainment of the PM10 NAAQS by the
required attainment date (i.e., 2017). Under CAA section 189(b)(1)(A),
the attainment demonstration for a Serious nonattainment area must
include air quality modeling. Please see the EPA's accompanying
Technical Support Document (TSD), located in the docket for this
action, for our detailed analysis of the air quality modeling
supporting the District's demonstration of attainment. In summary, the
EPA's preferred PM10 attainment demonstration approach is
dispersion modeling, with receptor modeling or emissions inventory
approaches as adjuncts. However, emissions from fugitive dust sources
such as the dry Owens Lake bed are uncertain and variable in comparison
with the typical industrial point sources to which dispersion modeling
is usually applied. Also, in a fugitive dust-dominated area there are
few if any chemical differences between the various emitting source
regions within the area, so receptor modeling is of limited use.
Therefore, emissions inventory-based modeling approaches have been used
in fugitive dust and other PM10 nonattainment areas. These
include the ``rollback'' of monitored concentrations in proportion to
emissions, sometimes in conjunction with a dispersion model in order to
account for the spatial and temporal variation of emissions and their
various distances from the monitor(s). In all of the approaches,
projected emissions reductions due to control measures are applied to
the emission source contributions, and attainment is demonstrated if
the resulting concentrations are below the NAAQS.\46\
---------------------------------------------------------------------------

    \46\ Monitored concentrations meet the 24-hour PM10
NAAQS when the ``design value,'' the expected number of daily
exceedances of the NAAQS level of 150 [mu]g/m\3\, is no more than
one per year, 40 CFR 50.6. However, for a modeled attainment
demonstration, when five years of meteorology are modeled, the 6th
highest concentration is used as the ``design concentration'' to
compare to the NAAQS level; at most five exceedances of that level
are acceptable for attainment, one per modeled year. Guideline on
Air Quality Models, 40 CFR 51 Appendix W, section <IP_ADDRESS>, ``Design
Concentrations for SO2, PM10, CO, Pb, and
NO2'' The design concentration is sometimes referred to
as the ``design value,'' but strictly speaking, the PM10
design value is the expected number of exceedances per year.
---------------------------------------------------------------------------

3. Modeling in Submittal
    The District used a hybrid modeling approach combining the CALPUFF
(``California Puff'') dispersion model \47\ with a monitored component.
CALPUFF is used to model the effect of emissions from sources on the
Owens Lake bed and the Keeler Dunes. The monitored component is used to
represent the effect of other sources off the lake bed (``out-of-
network''), which are not otherwise included in the CALPUFF modeling;
it is a time-varying background concentration that declines over time
as lake bed emissions are controlled. The District's hybrid model and
its inputs are discussed in more detail in our TSD.
---------------------------------------------------------------------------

    \47\ Model code and documentation are available at no cost for
download from http://www.src.com/calpuff/calpuff1.htm.
---------------------------------------------------------------------------

    The District's model performance evaluation \48\ of the hybrid
model, which checked model predictions against monitored observations
during the five-year period of July 2009 to June 2014, showed a high
correlation between them and acceptable model performance.
---------------------------------------------------------------------------

    \48\ 2016 PM10 Plan, Appendix VII-1: Air Quality
Modeling Report, sec. 5.
---------------------------------------------------------------------------

    The attainment demonstration also examined the effect of the
controls through implementation of Rule 433 and controls on the Keeler
Dunes that would be in place by the end of 2017, the attainment year.
Each of the five meteorology years was modeled, and for a given
receptor the highest sixth-high concentration taken as the design
concentration. The design concentration results for each monitor site
for 2014 through 2019 are shown in Table 7-5 of the 2016
PM10 Plan. For 2017, the highest design concentration is 142
[mu]g/m\3\ and all concentrations are less than 150 [mu]g/m\3\,
demonstrating attainment of the PM10 NAAQS.
4. Evaluation of Modeled Attainment Demonstration
    The dry Owens Lake bed presents a unique situation for which
unconventional modeling approaches may be appropriate. The EPA has
consulted with the District and CARB on the modeling approach numerous
times over the past decade, including during the year prior to the
current Plan submittal. As discussed in detail in our TSD and in the
summary below, the District's air quality modeling analysis is
appropriate for this area.
a. Model Emissions Input
    The District's Dust Identification (ID) Program, described in
detail in the TSD, provides estimates of PM10 emissions
based on real-time measurements at numerous locations. It provides a
level of detail and accuracy that is unique, and is a considerable
refinement over standard emission factors, and even over locale-
specific emission factors that account for soil type and wind speed. It
provides a strong foundation for the emission estimates needed for a
modeled attainment demonstration.
b. Model Choice
    The District's method for estimating PM10 emission
factors (i.e., back-calculation from monitored concentrations, also
discussed in detail in the TSD), depends on good characterization of
source-receptor relationships (emitting source square and monitor
receptor) to determine which particular emitting areas are contributing
to a given monitored concentration. A Lagrangian puff model like
CALPUFF, which allows PM10 emissions to follow a realistic
curved trajectory between the source area and the monitor and allows
different wind direction to vary by location at any given time, is
appropriate for this demonstration. CALPUFF is preferable to a steady-
state Gaussian model like AERMOD, which has ``straight-line''
trajectories along a single wind direction within any given hour for
all sources.

c. Modeling Domain and Background Concentration
    The District's monitoring and modeling network is focused on the
lake bed and the immediately surrounding area. In order for the
attainment demonstration to account for all the PM10
emission sources contributing to NAAQS violations, off-lake sources
must be adequately represented in the background concentration that is
added to the model prediction. The District's procedure for determining
background concentration is discussed in detail in the TSD. The EPA
finds the District's reasoning and supporting documentation for the
assumptions convincing.
d. Modeling Receptors
    By default, a grid of model receptors is used to cover much of a
nonattainment area, to ensure that the NAAQS is attained everywhere in
the area. In the 2016 PM10 Plan, receptors are placed only
along the lake bed shoreline, and further, only at monitor locations.
As stated in the 2016 PM10 Plan, the monitoring sites were
chosen to be downwind of the largest PM10 source areas, i.e.
the lake bed, and so are representative of the highest expected
impacts.\49\ Because concentrations necessarily decline with distance
from a non-buoyant source like fugitive dust, the EPA agrees that the
highest PM10 concentrations would be expected at the
shoreline.
---------------------------------------------------------------------------

    \49\ Id., p. 62 sec.7.1.
---------------------------------------------------------------------------

5. The EPA's Proposed Action
    In summary, the attainment demonstration is based on a unique
modeling approach that incorporates real-world measurements and is
well-suited to the special conditions at Owens Lake. The EPA is
proposing to find that the attainment demonstration in the 2016
PM10 Plan is approvable.

C. Five Percent Requirement

    Section 189(d) of the CAA requires a state with a Serious
PM10 nonattainment area that fails to attain the
PM10 NAAQS by the applicable attainment deadlines to submit
within 12 months after the attainment applicable attainment date, a
plan showing an annual five percent reduction in emissions of
PM10 in the area from the date of the submission until
attainment, based on the most recent inventory.
    Table 4-3 in the 2016 PM10 Plan provides a summary of
the annual emissions forecast for sources of emissions in the
nonattainment area for the years 1999 through 2019. The inventory
values are derived using a combination of modeling data, monitoring
results, CARB emissions inventories and control measure
efficiencies.\50\
---------------------------------------------------------------------------

    \50\ Id., at 34-35.
---------------------------------------------------------------------------

    The 2016 PM10 Plan includes a demonstration of annual
five percent reductions in Chapter 8. As noted, fugitive windblown
emissions, ``which are tied to meteorology and are highly irregular
year-to-year,'' \51\ account for most of the emissions in the Owens
Valley PM10 NA.\52\ To accommodate this variability for a
more stable and realistic assessment of reductions, the District used a
three-year rolling average to calculate the annual reductions. Using
average annual emissions from 2005-2007 (62,734 tpy) as the starting
point for the required five percent per year reductions, the District
is required to reduce emissions by 31,367 tons per year by the
attainment year (2017) to 32,367 tons per year. The GBUAPCD projects
three-year annual average emissions in 2017 to be 24,783 tons per year,
which exceeds the required amount of required reductions by 7,584 tons
per year. Figure 8-1 in the 2016 PM10 Plan illustrates
emissions trends for various sources in the nonattainment area from
1999 through 2019 along with the three-year average total, and compares
these values with a five percent reduction line.\53\
---------------------------------------------------------------------------

    \51\ For example, emissions totaled 109,635 tons in 2005,
dropped to 37,613 tons in 2006, then rose to 73,999 tons in 2009
before beginning to consistently decline. Emissions in 2010 totaled
70,343 tons and by 2017 when attainment will be reached, emissions
are projected to be 23,450 tons per year. 2016 PM10 Plan,
Table 4-3.
    \52\ Id., p. 81.
    \53\ The EPA believes the use of 2007 as the baseline for five
percent reductions is reasonable and consistent with Congress'
intent. Section 189(d) states that plans are due within 12 months of
the missed attainment deadline and that the plans should provide for
annual five percent reductions from the date of the submission until
attainment. The attainment deadline for the Owens Valley
PM10 NA was December 31, 2006. 64 FR 48305 (September 3,
1999). Accordingly, a submittal to fulfill section 189(d) was due by
December 31, 2007. Arguably, some of the reductions in the RFP
demonstration occurred outside the literal time frame specified by
Congress (i.e., ``the date of the submission'' of the Plan) because
the 2016 PM10 Plan was not submitted until June 9, 2016.
The EPA believes that it is appropriate and consistent with
Congress's intent for expeditious attainment of the NAAQS that we
consider reductions that occurred prior to the submittal of the 2016
PM10 Plan.
---------------------------------------------------------------------------

    Although annual emissions increase in the first few years of the
planning period, a steady decline begins in 2009.\54\ The average
emissions reductions catch up with the five percent per year reduction
target in 2013, and subsequently exceed the required reductions beyond
the projected attainment year. The EPA recognizes the unprecedented
challenges faced by the District in achieving this target. In light of
the unique nature of the source of emissions in the Owens Valley
PM10 NA, the groundbreaking technical efforts needed to
characterize and control emissions from the lake bed, and the
unavoidable delays in implementing controls on the lake bed caused by
litigation, and in recognition of the achievement of reductions beyond
those required under CAA section 189(d) after 2013, we are proposing to
approve the five percent demonstration in the 2016 PM10
Plan.
---------------------------------------------------------------------------

    \54\ The District notes that a substantial portion of the total
reductions achieved beginning in 2006 and forecast through 2017
occur from 2010 to 2014 with the implementation of the 2008 SIP
Control Areas and Phase 8 Control Area, which are described in
Sections <IP_ADDRESS> and <IP_ADDRESS> of the Plan. 2016 PM10 Plan,
p. 85.
---------------------------------------------------------------------------

D. BACM/BACT and Adopted Control Strategy

1. Background
    Section 189(b)(1)(B) of the CAA requires areas designated as
Serious nonattainment for PM10 to implement BACM and BACT
\55\ on all significant sources of direct PM10 and
PM10 precursors. The CAA does not define a BACM-level of
control for specific sources. In our guidance for Serious
PM10 nonattainment area plans, the EPA defined BACM to be,
among other things, the maximum degree of emission reduction achievable
from a source or source category which is determined on a case-by-case
basis, considering energy, economic and environmental impacts.\56\
Consistent with the General Preamble Addendum, a BACM analysis should
include the following elements for the Owens Valley PM10 NA:

    \55\ BACT, which applies to stationary sources, is a subset of
BACM.
    \56\ See 59 FR 41998, 42010 (August 16, 1994).
---------------------------------------------------------------------------

     Preparation of an inventory of PM10 sources;
     Identification of source categories having a greater than
de minimis impact on ambient PM10 concentrations;
     Comparative analysis of the controls implemented in the
Owens Valley PM10 NA and BACM in other Serious nonattainment
areas for significant source categories; and
     Evaluation of reducing emissions from a particular source
category and costs associated with controls.
2. Analysis
    The GBUAPCD BACM analysis, which addresses the four elements
described in the General Preamble Addendum,\57\ is summarized below.
The GBUAPCD's Rule 433 contains the BACM control measures for the Owens

Lake bed. The EPA approved Rule 433 into the SIP on November 10,
2016.\58\ In addition, the GBUAPCD is directly implementing controls at
the Keeler Dunes as discussed further below.
---------------------------------------------------------------------------

    \57\ 2016 PM10 Plan, page 38.
    \58\ Acting Regional Administrator Alexis Strauss signed the
EPA's final action approving Rule 433 on November 10, 2016. It will
be published in the Federal Register in the near future.
---------------------------------------------------------------------------

a. Inventory
    The emissions inventories included in the 2016 PM10 Plan
and in additional information submitted on October 26, 2016 are
summarized and evaluated in section II.A, above. As noted previously,
the EPA is proposing to find that the 2016 PM10 Plan's
emissions inventories for 2006 through 2019 are comprehensive,
accurate, and current inventories of actual emissions from all sources
in the Owens Valley PM10 NA and that these emissions
inventories meet the requirements of Section 172(c)(3) of the CAA and
the EPA.
b. Identification of Source Categories
    The General Preamble Addendum provides that BACM are required for
all categories of sources in Serious areas unless the State adequately
demonstrates a particular source category does not contribute
significantly to nonattainment of the NAAQS. A source category is
presumed to contribute significantly to a violation of the 24-hour
PM10 NAAQS if its PM10 impact at the location of
expected violation would exceed 5 [mu]g/m\3\.\59\
---------------------------------------------------------------------------

    \59\ 59 FR 41998, 42011.
---------------------------------------------------------------------------

    To determine which sources contribute significantly to
PM10 violations and are therefore subject to BACM level
controls, the GBUAPCD selected a day on which measured levels of
particulate approached the level of the standard and the predominant
source of emissions was characterized as ``non-lake.'' The District
noted that its choice is conservative because it ``produces a small de
minimis emissions level and makes it feasible for non-lake sources to
be considered significant.'' \60\ By dividing the threshold value for a
significant contribution (i.e., 5 [mu]g/m\3\) by ambient level of
PM10 on the chosen day (150.1 [mu]g/m\3\), Great Basin
calculated a de minimis factor of 3.33 percent.
---------------------------------------------------------------------------

    \60\ 2016 PM10 Plan, page S-3.
---------------------------------------------------------------------------

    The GBUAPCD provided an inventory of sources of precursor emissions
that we used to determine if sources of precursors contribute
significantly to ambient levels of PM10 exceeding the
standard in the Owens Valley PM10 NA. Because of the gaseous
nature of precursor emissions, these compounds would have the potential
for long distance transport, so emissions from the entire nonattainment
area are considered. Adding together emissions of PM10 from
within the near-lake area on a near exceedance day and precursor
emissions from throughout the nonattainment area results in a total of
535.37 tons per day of emissions. Multiplying this number by 3.33
percent yields a de minimis threshold of 17.8 tons per day.
    In determining whether sources of precursors contribute
significantly to PM10 levels, we made two conservative
assumptions. First, we assumed that all precursor emissions would
result in the formation of PM10. Second, we compared the
total emissions for all precursors (i.e., 4.7 tons per day), rather
than emissions of each precursor from each source category, to the de
minimis threshold of 17.8 tons per day. Given total precursor emissions
are far below the de minimis threshold, we conclude precursors do not
contribute significantly to PM10 levels in the Owens Valley.
    To determine which sources of direct PM10 are
significant, the District multiplied the near-exceedance day
PM10 emissions inventory (530.65 tons per day \61\) by the
de minimis factor, yielding a de minimis emissions threshold of 17.7
tons per day.\62\
---------------------------------------------------------------------------

    \61\ This number does not include precursor emissions, which is
acceptable because precursors do not significantly contribute and
excluding precursor emissions results in a slightly lower (more
conservative) threshold for significance.
    \62\ 2016 PM10 Plan, p. 4.
---------------------------------------------------------------------------

    Table 3 below summarizes the sources of PM10 emissions
in the Owens Lake subarea, on the analyzed day.\63\
---------------------------------------------------------------------------

    \63\ The GBUAPCD notes that ``monitoring and modeling analyses
indicate that emissions from off-lake sources more than two
kilometers away do not have an impact on achieving attainment'' and
cites a similar approach taken in the ``Five Percent Plan for
PM10 for the Maricopa County Nonattainment Area.'' Id.
Page 56.

      Table 3--PM10 Exceedance Day Inventory for Owens Lake Subarea
                              [2 km buffer]
------------------------------------------------------------------------
                                                        2015  (tons per
                       Category                            day) \64\
------------------------------------------------------------------------
Fugitive Windblown Dust from Exposed Lake Beds.......              45.30
Fugitive Windblown Dust from Keeler Dunes............             169.20
Fugitive Windblown Dust from Olancha Dunes...........             312.00
Other sources within the Owens Lake Subarea,                        4.15
 including mineral processing, paved and unpaved road
 dust, and the Lone Pine Landfill \65\...............
                                                      ------------------
    Total............................................             530.65
------------------------------------------------------------------------

    Using the 17.7 tons per day threshold, the GBUAPCD identified three
significant PM10 source categories in the OVPA:
---------------------------------------------------------------------------

    \64\ Id. Table S-2.
    \65\ BACT, which applies to stationary sources, is generally not
applicable within the Owens Valley PM10 NA where all
PM10 sources except for wind erosion from the dry Owens
Lake bed and the dune systems are de minimis.
---------------------------------------------------------------------------

     Fugitive windblown dust from exposed lake bed.
     Fugitive windblown dust from Keeler Dunes.
     Fugitive windblown dust from Olancha Dunes.
    Based on this analysis, the District focused its BACM demonstration
on the controls required on the lake bed and on the Keeler Dunes.\66\
According to the GBUAPCD, the Olancha dunes are primarily natural. If
PM10 violations are attributed to these dunes, the
violations will be treated as natural events and a Natural Events
Action Plan will be developed and implemented in accordance with the
EPA's guidance and rules on Exceptional Events.\67\ Further, emissions
from the Olancha Dunes are expected to be reduced by

about 2090 tons per year as the result of lake bed controls, which will
reduce sand migration from nearby areas and allow redeposited lake bed
particulate to winnow away until emissions are those of a natural dune
system.\68\
---------------------------------------------------------------------------

    \66\ The GBUAPCD has investigated the history and morphology of
the Keeler Dunes and determined that the drying of the Owens Lake
bed resulted in the expansion of the pre-existing, natural dune
area. 2016 PM10 Plan, page 61.
    \67\ Id. See Appendix V-1, ``OVPA 2016 SIP BACM Assessment,''
Appendix E, ``2013 GBUAPCD Board Order No. 130916-01,'' p. 7.
    \68\ Id., pp. 34 and 56.
---------------------------------------------------------------------------

c. Comparative Analysis
    To fulfill the requirement for a comparative analysis, the GBUAPCD
searched for requirements for analogous lake bed and dune sources in
other PM10 nonattainment areas including Imperial County,
the San Joaquin Valley, Maricopa County (Phoenix area), the South
Coast, and Clark County (Las Vegas area). However, the District was
unable to identify any analogous active controls for these kinds of
sources in other areas. The District concludes that ``these measures
are unique in the US and are, by definition, the most stringent
requirements for these sources.'' \69\ A description of the lake bed
and dune controls follows.
---------------------------------------------------------------------------

    \69\ Id. See Appendix V-1, ``OVPA 2016 SIP BACM Assessment,'' p.
22.
---------------------------------------------------------------------------

i. Lake Bed Controls
    Lake bed controls are set forth in the GBUAPCD's Rule 433, which is
included in the 2016 PM10 Plan. The EPA has approved Rule
433 into the SIP in a separate action.\70\ Rule 433 requires the
control measures described in Chapter 6 of the 2016 PM10
Plan and summarized in our TSD to be implemented by the City of Los
Angeles on various portions of the dry Owens Lake bed.\71\ In brief,
Rule 433 requires the City of Los Angeles to conduct shallow flooding
through application of water, install managed vegetation or a gravel
blanket, or in some cases use tillage with a brine back-up. These
control measures typically result in a 99 to 100 percent control
efficiency. Beginning in 2001, lake bed controls have been constructed
in phases as modeling and empirical evidence have demonstrated the need
for additional controls. Rule 433 requires ongoing implementation of
previously established control requirements and includes an enforceable
implementation schedule for the most recent phase of controls, with all
controls in place in the attainment year of 2017.
---------------------------------------------------------------------------

    \70\ 81 FR 62849 (September 13, 2016); final approval signed
November 10, 2016.
    \71\ For more detail on the Owens Lake bed controls, see Chapter
6 of the 2016 PM10 Plan and our TSD. Some of these
control measures are also described in our proposed approval of the
1998 Plan (64 FR 34173, June 25, 1999).
---------------------------------------------------------------------------

ii. Dune Controls
    The District is in the process of implementing a dust control
project on Keeler Dunes that involves the placement of approximately
82,000 straw bales and planting of approximately 246,000 native
shrubs.\72\ The goal of the project is to create a stable, non-
emissive, low-impact vegetated dune system that requires minimal
resources to maintain. The placement of the straw bales was completed
in 2015 and plantings are scheduled to be complete by the end of 2016.
At full build-out, the GBUACPD projects the project will reduce
PM10 emissions by approximately 95 percent and bring the
community of Keeler into compliance with state and federal
PM10 standards.\73\ Implementation of this project is made
federally enforceable by approval of the 2016 PM10 Plan,
which includes Resolution 2016-03 wherein the Governing Board of the
GBUAPCD authorizes and commits the District to complete the Keeler
Dunes Project as set forth in the Plan.
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    \72\ As noted above, no additional active controls are
anticipated for the Olancha Dunes.
    \73\ 2016 PM10 Plan, pp. 19 and 50-53
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    In the context of its environmental review of the Keeler Dunes
Project, the District considered alternatives for reducing the
windblown dust from the Keeler Dunes, such as covering with geotextile
fabric and gravel or excavation and removal of the dunes, but found
them to be infeasible.\74\
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    \74\ Id. See Appendix V-1, ``OVPA 2016 SIP BACM Assessment,''
pp. 16-17.
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d. Evaluation of Reducing Emissions From Windblown Dust and Associated
Costs
    The GBUAPCD estimated cost and emission impacts of the exposed lake
bed and Keeler Dune controls as shown in Table 4 below:

         Table 4--Impact Analysis: Control Effectiveness, Cost Information, and Cost Effectiveness \75\
----------------------------------------------------------------------------------------------------------------
                                                                                Cost
  Source category (and windblown      Average annual          Control               Costs          effectiveness
          dust controls)             emissions (tons)      effectiveness                              (tons)
----------------------------------------------------------------------------------------------------------------
Dry Lake Bed (varied controls,     2006: 73,174; 2010:  Up to 99 percent     $145.8M                      $2,390
 including shallow flooding,        43,325; 2014:        depending on         (annualized) for
 gravel blanket, and managed        1,936                control and          2016 SIP.
 vegetation. See Rule 433.).                             location.
Off-Lake Dunes (straw bales and    3,309..............  95 percent based on  $700,000                        222
 re-vegetation).                                         straw bales with     (annualized) for
                                                         future shrub         straw bales and
                                                         establishment.       revegetation with
                                                                              watering.
----------------------------------------------------------------------------------------------------------------

3. EPA Evaluation and Proposed Action
    In the 2016 PM10 Plan, the GBUAPCD has provided
documentation on Rule 433 and on the Keeler Dunes Project, quantifying
the cost of construction, materials, operation, and maintenance, and
examining other factors such as energy and environmental impacts. The
EPA agrees that adequate time must be allowed to fully implement Rule
433 successfully because the control measures in the Rule are uniquely
vast in scale, materials, and required construction activity. Rule 433
establishes an aggressive, phased, implementation schedule that we are
proposing to find is as expeditious as practicable. We also find that
the implementation schedule for the Keeler Dunes project is as
expeditious as practicable.
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    \75\ Id. See Appendix V-1, ``OVPA 2016 SIP BACM Assessment,'' p.
21.
---------------------------------------------------------------------------

    The EPA concludes that the 2016 PM10 Plan demonstrates:
    (1) Wind erosion from the dry Owens Lake bed (and secondarily, from
the Keeler Dunes, which have expanded as a result of redeposited
particles transported from the dry lake bed \76\), is the predominant
source of PM10 emissions that cause or contribute to
PM10 violations in the Owens Valley PM10 NA and
that applying BACM to

other source categories would not contribute significantly to achieving
the NAAQS as expeditiously as practicable;
---------------------------------------------------------------------------

    \76\ Id., page 61.
---------------------------------------------------------------------------

    (2) Rule 433's control measures to reduce windblown dust from the
dry Owens Lake bed and area immediately surrounding the bed of Owens
Lake are unique and satisfy the requirement for BACM.
    (3) The goal of the Keeler Dunes Project is to create a stable
self-sustaining low-impact vegetated dune system to reduce wind
erosion. Implementation of these controls represents BACM since there
are no analogous dust control projects or alternative controls for this
type of source; and
    (4) No analogous source has been identified to support the economic
and technological feasibility of any alternative or additional measures
for the control of significant sources of wind erosion emissions in the
Owens Valley PM10 NA.

E. Reasonable Further Progress/Quantitative Milestones

    CAA section 189(c) requires that PM10 nonattainment
areas must include quantitative milestones that are to be achieved
every three years and that show RFP toward attainment by the applicable
attainment deadline. Quantitative milestones may be met in a variety of
ways, including by establishing a percent implementation of various
control strategies, by percent compliance with implemented control
measures, or adherence to a compliance schedule.\77\ Prior to submittal
of the 2016 PM10 Plan, lake bed controls were established
that yielded significant emissions reductions, as reflected in the
annual emissions inventory \78\ and illustrated in Figure 8-1 of the
Plan. Unsurprisingly, given the variable nature of the emissions
sources and the periodic delays due to disputed control measures, the
decline is not linear; however, as noted previously, reductions
sufficient to provide for attainment will be achieved within the
required timeframe. Under the circumstances, we find that the progress
achieved prior to the 2016 adoption of the Plan is reasonable.
---------------------------------------------------------------------------

    \77\ 59 FR 41998 at 42016.
    \78\ 2016 PM10 Plan, Table 4-3.
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    The GBUAPCD's Rule 433 and the Keeler Dunes Project establish
requirements for additional controls that will be completed in 2017 and
that provide for additional emissions reductions. Under Rule 433, the
City of Los Angeles must continue to implement all control measures
that are already in place,\79\ and must implement Phase 9/10, which
requires the control of an additional 3.62 square miles of the Owens
Lake bed by December 31, 2017. These control requirements include
enforceable schedules for implementation of the specified control
measures, and the Plan includes quantification of the emissions
reductions that will be achieved by implementation of the control
measures.
---------------------------------------------------------------------------

    \79\ These areas consist of the 2003 Dust Control Area (29.8
square miles), the 2006 Dust Control Area and Channel Area (13.2
square miles), and the Phase 8 area (2.0 square miles).
---------------------------------------------------------------------------

    In its discussion of the requirement for quantitative milestone
reports, the District noted that the remaining milestone for the 2016
PM10 Plan is the completion of the Phase 9/10 dust controls,
which are enforceable through Rule 433. In other words, the final
quantitative milestone for the 2016 PM10 Plan is 100 percent
implementation of the required controls. The GBUAPCD commits to
submitting a report to the EPA by April 1, 2018, as required by Section
189(c)(2) of the Act, that demonstrates RFP thorough the achievement of
the December 31, 2017 quantitative milestone.
    The EPA proposes to approve the enforceable schedule in Rule 433
and commitment for completion of the Keeler Dunes Project in 2016 as
meeting the RFP requirements of CAA section 189(c).

F. Contingency Measures

    The CAA requires that the 2016 PM10 Plan include
contingency measures to be implemented if the area fails to meet
progress requirements or fails to attain the NAAQS by the applicable
deadline. These contingency measures should take effect without
requiring further action by the state or the EPA and should be fully
implemented as expeditiously as practicable.\80\ Contingency measures
should also provide for emissions reductions equivalent to one year's
average increment of RFP.\81\
---------------------------------------------------------------------------

    \80\ 59 FR 41998 at 42015.
    \81\ Id.
---------------------------------------------------------------------------

    Because it is not possible to predict which areas of the lake bed
may become emissive and cause a failure to meet progress requirements
or to attain the NAAQS, Rule 433 requires the District to evaluate at
least once per calendar year whether additional areas of the lake bed
require controls. If the GBUAPCD determines that the Owens Valley
PM10 NA has not met progress requirements or will not timely
attain, Rule 433 requires the implementation of BACM control measures
on up to an additional 4.78 square miles of the Owens Lake bed as
expeditiously as practicable. The implementation of the contingency
measure in Rule 433 does not require additional rulemaking actions or
public hearings. The EPA has concluded, therefore, that the contingency
measure included in the 2016 PM10 Plan through adopted Rule
433 provides for the implementation of contingency measures as
expeditiously as practicable.
    The GBUAPCD has demonstrated that the dry lake bed is the
overwhelming contributor the exceedances of the PM10 NAAQS,
both through PM10 originating directly from the lake bed, or
from lake bed particles that have been deposited nearby, which then
become a secondary source of particulate (e.g., the Keeler Dunes).\82\
Therefore, we have focused our analysis on the control of emissions
emanating from the lake bed in assessing whether the contingency
measure in the 2016 PM10 Plan provides a year's worth of
average RFP increment.
---------------------------------------------------------------------------

    \82\ For additional discussion, see Chapter 7 of the 2016
PM10 Plan and the attainment demonstration analysis in
the TSD for this action.
---------------------------------------------------------------------------

    Determining the amount of emissions reductions needed for
contingency measures (i.e., a year's worth of reductions) presents a
unique challenge in the Owens Valley PM10 NA due to the
nature of the lake bed and the meteorological influence on emissions,
which leads to a degree of variability in annual emissions that is
somewhat independent of the application of controls. For this reason,
we have used the annual average area of the lake bed on which controls
are required for the period of 2007 (the year the EPA made a finding of
failure to attain) through 2017 (the attainment year) as a surrogate
for the annual amount (tons) of emissions reductions required. This
results in an annual average area of 1.8 square miles.\83\ Rule 433
provides for the implementation of controls on an additional 4.78
square miles of lake bed, which is more than double the annual average.
We therefore conclude the contingency measure provisions in Rule 433
satisfy the contingency measure requirements under CAA section
172(c)(9).
---------------------------------------------------------------------------

    \83\ A total of 18.2 square miles will be controlled in 10-year
period of 2007 through 2017 (the 2006 Dust Control and Channel Area
encompasses 13.2 square miles; the Phase 8 Area encompasses 2.0
square miles; the Phase 9/10 Area encompasses 3.62--the
provisionally excluded Cultural Resource Areas encompass
approximately 0.6 square miles).
---------------------------------------------------------------------------

G. Transportation Conformity

    Transportation conformity is required by CAA section 176(c). Our
conformity rule (40 CFR part 93, subpart A) requires that
transportation plans, programs, and

projects conform to state air quality implementation plans and
establishes the criteria and procedures for determining whether or not
they do so. Conformity to a SIP means that transportation activities
will not produce new air quality violations, worsen existing
violations, or delay timely attainment of the NAAQS or the timely
achievement of interim milestones. However, if the EPA determines that
a SIP demonstrates that motor vehicle emissions are an insignificant
contributor to the air quality problem, states are not required to
establish motor vehicle emissions budgets or perform a regional
emissions analysis for transportation conformity purposes.\84\
---------------------------------------------------------------------------

    \84\ 40 CFR 93.109(f).
---------------------------------------------------------------------------

    In section 6.1.2 of the Plan, the GBUAPCD provides its argument for
why motor vehicle emissions are insignificant contributors to the
PM10 problem in the Owens Valley PM10 NA. First,
the District noted that motor vehicle tailpipe emissions and re-
entrained roadway dust contribute just 1.4 percent of the 2016
PM10 emissions. The District also observed that the State
estimates the annual population growth (about 0.7 percent) and increase
in vehicle miles traveled (about 1.2 percent annually) and argued that
it is unlikely that ``these emissions would grow to such an extent as
to cause a NAAQS violation in the future.'' Finally, the District
pointed out the absence of measures in the SIP that control motor
vehicle emissions. In light of these factors, the EPA concurs with the
District's conclusion that motor vehicle emissions are insignificant
contributors to the PM10 problem in the Owens Valley.
Accordingly, the GBUAPCD is not required to establish motor vehicle
budgets in this plan or to perform regional emissions analyses for
transportation conformity.

III. Summary of the EPA's Proposed Action

    The EPA is proposing to approve the Serious area 2016
PM10 Plan submitted by the State of California for the Owens
Valley PM10 nonattainment area. Specifically, the EPA is
proposing to approve the 2016 PM10 Plan with respect to the
CAA requirements for public notice and involvement under section
110(a)(1); emissions inventories under section 172(c)(3); the control
measures in Rule 433 under section 110(k)(3), as meeting the
requirements of sections 110(a) and 189(b)(1)(B); RFP and quantitative
milestones under section 189(c); the contingency measure in Rule 433
under section 172(c)(9); and demonstration of attainment under section
189(b)(1)(A). The EPA is also proposing to approve the State's request
for an extension of the attainment date to June 6, 2017 pursuant to CAA
sections 188 and 179.

IV. Statutory and Executive Order Reviews

    Under the Clean Air Act, the Administrator is required to approve a
SIP submission that complies with the provisions of the Act and
applicable federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a).
Thus, in reviewing SIP submissions, the EPA's role is to approve State
choices, provided that they meet the criteria of the Clean Air Act.
Accordingly, this proposed action merely proposes to approve State law
as meeting federal requirements and does not impose additional
requirements beyond those imposed by State law. For that reason, this
proposed action:
     Is not a ``significant regulatory action'' subject to
review by the Office of Management and Budget under Executive Order
12866 (58 FR 51735, October 4, 1993);
     Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact
on a substantial number of small entities under the Regulatory
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or
uniquely affect small governments, as described in the Unfunded
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have Federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based
on health or safety risks subject to Executive Order 13045 (62 FR
19885, April 23, 1997);
     Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272
note) because application of those requirements would be inconsistent
with the Clean Air Act; and
     Does not provide the EPA with the discretionary authority
to address disproportionate human health or environmental effects with
practical, appropriate, and legally permissible methods under Executive
Order 12898 (59 FR 7629, February 16, 1994).
    In addition, the SIP is not approved to apply on any Indian
reservation land or in any other area where the EPA or an Indian tribe
has demonstrated that a tribe has jurisdiction. In those areas of
Indian country, the rule does not have tribal implications and will not
impose substantial direct costs on tribal governments or preempt tribal
law as specified by Executive Order 13175 (65 FR 67249, November 9,
2000). We intend to offer to consult with local tribes during the
comment period.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Particulate matter, Reporting
and recordkeeping requirements.

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

    Dated: December 1, 2016.
Deborah Jordan,
Acting Regional Administrator, Region IX.
[FR Doc. 2016-29758 Filed 12-9-16; 8:45 am]
 BILLING CODE 6560-50-P