[Federal Register Volume 84, Number 133 (Thursday, July 11, 2019)]
[Proposed Rules]
[Pages 33035-33045]
[FR Doc No: 2019-14630]

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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R09-OAR-2019-0365; FRL-9996-40-Region 9]

Air Plan Approval; Nevada; Revisions to Clark County Ozone
Maintenance Plan

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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

SUMMARY: The Environmental Protection Agency (EPA) is proposing to
conditionally approve a revision to the State of Nevada's State
Implementation Plan (SIP) for Clark County. The revision consists of an
update to certain elements of the maintenance plan for the Clark County
air quality planning area for the 1997 8-hour ozone national ambient
air quality standards (NAAQS or ``standards''), including the emissions
inventories, maintenance demonstration, and motor vehicle emissions
budgets. The EPA is proposing to conditionally approve the SIP revision
because the Clark County ozone SIP, as revised, continues to provide
for maintenance of the 1997 ozone NAAQS and, upon fulfillment of
certain commitments, will not interfere with attainment or reasonable
further progress of the other NAAQS, and the budgets meet the
applicable transportation conformity requirements. The proposed
approval is conditional because it is based on commitments to submit a
SIP revision to reduce the safety margin allocations for the budgets
within one year of final conditional approval.

DATES: Comments must be received on or before August 12, 2019.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2019-0365, at https://www.regulations.gov. For comments submitted
at Regulations.gov, follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
Regulations.gov. The EPA may publish any comment received to its public
docket. Do not submit electronically any information you consider to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Multimedia submissions (audio,
video, etc.) must be accompanied by a written comment. The written
comment is considered the official comment and should include
discussion of all points you wish to make. The EPA will generally not
consider comments or comment contents located outside of the primary
submission (i.e., on the web, cloud, or other file sharing system). For
additional submission methods, please contact the person identified in
the FOR FURTHER INFORMATION CONTACT section. For the full EPA public
comment policy, information about CBI or multimedia submissions, and
general guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Karina O'Connor, Air Planning Office
(AIR-2), EPA Region IX, 75 Hawthorne Street, San Francisco, CA 94105;
By phone:<PHONE_NUMBER> or by email at<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION: Throughout this document, whenever ``we,''
``us,'' or ``our'' is used, we mean the EPA. This supplementary
information section is arranged as follows:

Table of Contents

I. What action is the EPA proposing?
II. Background
    A. NAAQS, SIPs, Designations, and Transportation Conformity
    B. 1997 Ozone NAAQS and Clark County
    C. 2008 Ozone NAAQS and Clark County
    D. 2015 Ozone NAAQS and Clark County
    E. The MOVES Emission Model
III. What did the State submit?
IV. Procedural Requirements for Adoption and Submittal of SIP
Revisions
V. The EPA's Evaluation of the 2018 Ozone Maintenance Plan Revision

    A. Revised Attainment Inventory
    B. Revised Maintenance Demonstration
    C. Revised Motor Vehicle Emissions Budgets
    D. CAA Section 110(l) Evaluation
VI. Proposed Action and Request for Public Comment
VII. Statutory and Executive Order Reviews

I. What action is the EPA proposing?

    Under section 110(k) of the Clean Air Act (``Act'' or CAA), the EPA
is required to take action by approving, disapproving, or conditionally
approving, in whole or in part, SIPs and SIP revisions submitted by the
states. In today's action, the EPA is proposing to conditionally
approve a SIP revision titled ``Revision to Motor Vehicle Emissions
Budgets in Ozone Redesignation Request and Maintenance Plan: Clark
County, Nevada'' (October 2018) (herein, referred to as the ``2018
Ozone Maintenance Plan Revision''), submitted by the Nevada Division of
Environmental Protection (NDEP) on October 31, 2018. The 2018 Ozone
Maintenance Plan Revision updates certain elements of the maintenance
plan for Clark County for the 1997 ozone NAAQS, including the
attainment inventory, the maintenance plan, and the motor vehicle
emissions budgets (``budgets'' or MVEBs). The budgets were updated
using the EPA's MOtor Vehicle Emission Simulator emission model
released in 2014 (MOVES2014a). If the EPA takes final action to
conditionally approve the SIP revision, the updated budgets will
replace Clark County's existing budgets for the 1997 ozone NAAQS. At
that time, the previously-approved budgets would no longer be
applicable for transportation conformity purposes, and the revised
budgets would need to be used beginning on the publication date of the
EPA's final conditional approval in the Federal Register.\1\ The
proposed conditional approval is based on commitments from NDEP and the
Clark County Department of Air Quality (DAQ) to submit a SIP revision
within one year of final conditional approval.\2\ The purpose of the
future SIP revision is to reduce the safety margin allocations to the
budgets to ensure that the 2018 Ozone Maintenance Plan Revision, as
revised to reduce the safety margin allocations, will not interfere
with reasonable further progress or attainment of the 2008 and 2015
ozone NAAQS.
---------------------------------------------------------------------------

    \1\ 40 CFR 93.118(f)(2)(v).
    \2\ Letter from Jodi Bechtel, Assistant Director, Clark County
DAQ, to Greg Lovato, Administrator, NDEP, dated June 14, 2019; and
letter from Greg Lovato, Administrator, NDEP, to Elizabeth Adams,
Director, Air Division, EPA Region IX, dated June 21, 2019.
---------------------------------------------------------------------------

II. Background

A. NAAQS, SIPs, Designations, and Transportation Conformity

    Under section 109 of the CAA, the EPA promulgates NAAQS for
pervasive air pollutants, such as ozone. The NAAQS are concentration
levels that, the attainment and maintenance of which, the EPA has
determined to be requisite to protect public health and welfare. Once
the EPA has established a NAAQS or revised a NAAQS, section 110 of the
CAA requires states to adopt and submit to the EPA a plan, referred to
as the SIP, that provides for the implementation, maintenance, and
enforcement of such NAAQS. As noted previously, the EPA is required to
take action to approve, disapprove, or conditionally approve SIPs and
SIP revisions under CAA section 110(k).
    Under CAA section 107(d), the EPA must designate all areas of the
country as attainment, nonattainment or unclassifiable for new or
revised NAAQS. States with areas designated as nonattainment must
develop, adopt and submit SIP revisions to provide for, among other
things, attainment as expeditiously as practicable but no later than
certain dates and for reasonable further progress (RFP) towards
attainment.\3\ Once a nonattainment area has attained the NAAQS, the
state may request redesignation of the area from nonattainment to
attainment, and the EPA grants such requests if the criteria in CAA
section 107(d)(3)(E) are met, including the approval of a maintenance
plan (under CAA section 175A) that demonstrates how the area will
maintain the NAAQS for at least 10 years after the redesignation. Such
former nonattainment areas that have been redesignated to attainment
are referred to as ``maintenance areas.''
---------------------------------------------------------------------------

    \3\ See, generally, part D (``Plan Requirements for
Nonattainment Areas'') of Title I of the CAA.
---------------------------------------------------------------------------

    In the State of Nevada, NDEP is the Governor's designee for
adoption and submittal of SIPs and SIP revisions to the EPA. NDEP is
also responsible for regulation of stationary sources and development
of local air quality plans throughout much of the State of Nevada. In
Clark County, the Clark County DAQ is responsible under state law for
regulation of most types of stationary sources within the county and
for development of local air quality plans. Once adopted by the Clark
County Board of County Commissioners, such county plans are forwarded
to NDEP for adoption and submittal to the EPA as revisions to the
Nevada SIP.
    The emission control strategy SIP revisions (e.g., RFP and
attainment demonstration SIP revisions) and maintenance plans include
budgets of on-road mobile source emissions for criteria pollutants and/
or their precursors to address pollution from cars and trucks. The
budgets are the portions of the total allowable emissions that are
allocated to on-road vehicle use that, together with emissions from
other sources in the area, will provide for RFP, attainment or
maintenance. The budgets serve as a ceiling on emissions from an area's
planned transportation system.\4\
---------------------------------------------------------------------------

    \4\ For more information about budgets, see the preamble to the
November 24, 1993, transportation conformity rule (58 FR 62188).
---------------------------------------------------------------------------

    The CAA recognizes the connection between air quality planning and
transportation planning in nonattainment and maintenance areas and
includes specific provisions related to adoption and approval of
transportation programs, plans, and projects by Metropolitan Planning
Organizations (MPOs) and the U.S Department of Transportation's (DOT's)
Federal Highway Administration (FHWA) or Federal Transit Administration
(FTA). More specifically, under section 176(c) of the CAA,
transportation plans, Transportation Improvement Programs (TIPs), and
transportation projects must ``conform'' to (i.e., be consistent with)
the SIP before they can be adopted or approved. Conformity to the SIP
means that transportation activities will not cause new air quality
violations, worsen existing air quality violations, or delay timely
attainment of the NAAQS or delay an interim milestone. The EPA's
transportation conformity rule at 40 CFR part 93, subpart A establishes
the criteria and procedures that MPOs and DOT must use to determine
whether transportation activities conform to the SIP. Transportation
conformity applies to areas that are designated nonattainment and those
former nonattainment areas that have been redesignated to attainment
and have a CAA section 175A maintenance plan (``maintenance areas''),
but does not apply to areas designated as attainment or
unclassifiable.\5\
---------------------------------------------------------------------------

    \5\ CAA section 176(c)(5).
---------------------------------------------------------------------------

    Under certain circumstances, MPOs and DOT must determine conformity
based, in part, on a ``budget test'' that involves a comparison between
estimates of regional on-road mobile source emissions under a given
transportation plan or program with the budgets.\6\ Before budgets can
be used in

conformity determinations, however, the EPA must affirmatively find the
budgets adequate.\7\ However, adequate budgets do not supersede
approved budgets for the same CAA purpose. If the submitted SIP budgets
are meant to replace budgets for the same purpose, the EPA must approve
the budgets, and can affirm that they are adequate at the same time.
Once the EPA approves the submitted budgets, they must be used by state
and federal agencies in determining whether transportation activities
conform to the SIP as required by section 176(c) of the CAA. The EPA's
substantive criteria for determining the adequacy of budgets are set
out in 40 CFR 93.118(e)(4).
---------------------------------------------------------------------------

    \6\ CAA section 176(c)(1) and 40 CFR 93.109 and 93.118.
    \7\ The ``adequacy'' process is established in the EPA's
transportation conformity rule to provide a mechanism whereby
budgets in a submitted SIP revision that has undergone preliminary
review by the EPA can be used for transportation planning purposes
prior to final approval of the SIP revision.
---------------------------------------------------------------------------

    In Clark County, the area's MPO, the Regional Transportation
Commission of Southern Nevada (RTC) and DOT are the relevant
transportation agencies that must use approved or adequate budgets in
determining the conformity of transportation plans and TIPs within
Clark County.

B. 1997 Ozone NAAQS and Clark County

    Ground-level ozone pollution is formed from the reaction of
volatile organic compounds (VOC) and oxides of nitrogen
(NOX) in the presence of sunlight. These two pollutants,
referred to as ozone precursors, are emitted by many types of sources,
including on-and off-road motor vehicles and engines, power plants and
industrial facilities, and smaller area sources such as lawn and garden
equipment and paints. Scientific evidence indicates that adverse public
health effects occur following exposure to ozone, particularly in
children and adults with lung disease. Breathing air containing ozone
can reduce lung function and inflame airways, which can increase
respiratory symptoms and aggravate asthma or other lung diseases.\8\
---------------------------------------------------------------------------

    \8\ ``Fact Sheet--2008 Final Revisions to the National Ambient
Air Quality Standards for Ozone'' dated March 2008.
---------------------------------------------------------------------------

    As noted previously, the EPA promulgates NAAQS for pervasive air
pollutants, such as ozone, under CAA section 109. In 1997, the EPA
revised the ozone NAAQS to set the acceptable level of ozone in the
ambient air at 0.08 parts per million (ppm), averaged over an 8-hour
period (herein referred to as the ``1997 ozone NAAQS'').\9\ In 2004,
the EPA designated and classified all areas with respect to the 1997
ozone NAAQS, and designated Clark County as a ``Subpart 1''
nonattainment area for the 1997 ozone NAAQS.\10\ Later that year, the
EPA reduced the geographic extent of the ozone nonattainment area to a
portion of Clark County.\11\ In 2005, we published a final rule that we
would treat the effective date of the partial-county nonattainment area
designation the same as the designations for the rest of the country,
i.e., June 15, 2004.\12\
---------------------------------------------------------------------------

    \9\ 62 FR 38856 (July 18, 1997) and 40 CFR 50.10. Due to the
number of significant figures in the level of the standard, a
computed 3-year average ozone concentration of 0.085 ppm is the
smallest value that is greater than 0.08 ppm. 40 CFR part 51,
appendix I.
    \10\ 69 FR 23858 (April 30, 2004). The ``Subpart 1''
classification meant that the area was subject solely to the general
nonattainment area requirements under subpart 1 of part D (of title
I) of the CAA rather than to the requirements under both subparts 1
and the ozone-specific requirements under subpart 2. Several years
later, in response to litigation over the designations for the 1997
ozone NAAQS, the EPA revised the classification of the Clark County
ozone nonattainment area from ``Subpart 1'' to ``Subpart 2/
Marginal.'' 77 FR 28424 (May 14, 2012).
    \11\ 69 FR 55956 (September 17, 2004). The boundaries of the
Clark County ozone nonattainment (now maintenance) area for the 1997
ozone NAAQS are defined in 40 CFR 81.329. Specifically, the area is
defined as: ``That portion of Clark County that lies in hydrographic
areas 164A, 164B, 165, 166, 167, 212, 213, 214, 216, 217, and 218,
but excluding the Moapa River Indian Reservation and the Fort Mojave
Indian Reservation.'' The area includes a significant portion of the
unincorporated portions of central and southern Clark County, as
well as the cities of Las Vegas, Henderson, North Las Vegas and
Boulder City. The hydrographic areas are illustrated in Figure 1-1
of the Clark County Ozone Maintenance Plan (March 2011).
    \12\ 70 FR 71612 (November 29, 2005).
---------------------------------------------------------------------------

    As a ``Subpart 1'' area, the Clark County ozone nonattainment area
was subject to a number of requirements including the requirement to
demonstrate attainment of the 1997 ozone NAAQS as expeditiously as
practicable, but no later than five years from the date that the area
was designated nonattainment.\13\ In 2011, the EPA determined that the
Clark County 8-hour ozone nonattainment area had attained the 1997 8-
hour ozone NAAQS, based on complete, quality-assured, and certified
ambient air monitoring data that showed the area monitored attainment
of the 1997 ozone NAAQS for the 2007-2009 monitoring period.\14\
---------------------------------------------------------------------------

    \13\ CAA section 172(a)(2).
    \14\ 76 FR 17343 (March 29, 2011).
---------------------------------------------------------------------------

    In 2011, in light of ambient monitoring data showing that the Clark
County ozone nonattainment had attained the 1997 ozone NAAQS, NDEP
submitted the ``Ozone Redesignation Request and Maintenance Plan, Clark
County, Nevada (March 2011)'' (herein, the ``2011 Ozone Maintenance
Plan'') to the EPA for approval as a revision to the Clark County
portion of the Nevada SIP. Prepared by the Clark County DAQ, the 2011
Ozone Maintenance Plan includes the various elements found in most
maintenance plans, including an attainment inventory, maintenance
demonstration, monitoring network, verification of continued
attainment, contingency plan, and motor vehicle emissions budgets.
    For the 2011 Ozone Maintenance Plan, Clark County DAQ selected 2008
as the year for the attainment inventory of ozone precursors (i.e., VOC
and NOX), and demonstrated maintenance of the 1997 ozone
NAAQS through year 2022 by reference to emissions inventories developed
for future years 2015 and 2022 that showed that future emissions of VOC
and NOX would not exceed the level of the corresponding
emissions of the attainment inventory. The 2011 Ozone Maintenance Plan
established budgets for NOX and VOC for years 2008, 2015 and
2022. The budgets were derived from the on-road motor vehicle emissions
estimates prepared using the EPA's then-current on-road vehicle
emissions model, MOBILE6.2, and the most recent vehicle mix and
activity data then available from the RTC. In 2013, the EPA approved
the 2011 Ozone Maintenance Plan and redesignated the Clark County ozone
nonattainment area to attainment for the 1997 ozone NAAQS.\15\ The
subject of today's proposed action is a revision to the attainment
inventory, the maintenance demonstration and budgets of the 2011 Ozone
Maintenance Plan to reflect updated emissions models, vehicle mix and
speed data, and transportation activity projections. The other elements
of the 2011 Ozone Maintenance Plan (monitoring network, verification of
continued attainment, contingency plan) are not affected by this
action.
---------------------------------------------------------------------------

    \15\ 78 FR 1149 (January 8, 2013).
---------------------------------------------------------------------------

    Through adoption of the 2011 Ozone Maintenance Plan, Clark County
DAQ committed to maintaining an ambient air quality monitoring network
to verify the continued attainment of the 1997 ozone NAAQS in the Clark
County ozone maintenance area.\16\ At the present time, monitors
operating at 10 monitoring sites continuously monitor ambient
concentrations of ozone within the maintenance area. Since 2008, i.e.,
the year used for the attainment inventory in the 2011 Ozone
Maintenance Plan, Clark County has experienced a decrease in ambient
ozone concentrations. As shown in Table 1, 8-hour ozone design values
have decreased from 0.082 ppm in 2008

to 0.074 ppm in 2017.\17\ In more recent years, the design value has
remained relatively steady, varying little from year to year. Table 1
shows that Clark County has maintained the 1997 ozone NAAQS through the
first 5 years (2013 through 2017) of the first maintenance period.
---------------------------------------------------------------------------

    \16\ 2011 Ozone Maintenance Plan, page 6-11.
    \17\ Under EPA regulations at 40 CFR 50.10 and appendix I, the
1997 ozone NAAQS is attained at a site when the 3-year average of
the annual fourth-highest daily maximum 8-hour average ozone
concentration is less than or equal to 0.08 ppm. This 3-year average
is referred to as the design value. When the design value is less
than or equal to 0.084 ppm (based on the rounding convention in 40
CFR part 50, appendix I) at each monitoring site within the area,
then the area is meeting the 1997 ozone NAAQS. The highest design
value among the various ozone monitoring sites represents the design
value for the area.

   Table 1--Eight-Hour Ozone Design Values for the Clark County Ozone
                       Maintenance Area, 2008-2017
------------------------------------------------------------------------
                                                           Design value
                          Year                                 (ppm)
------------------------------------------------------------------------
2008....................................................           0.082
2009....................................................           0.078
2010....................................................           0.076
2011....................................................           0.075
2012....................................................           0.076
2013....................................................           0.077
2014....................................................           0.078
2015....................................................           0.075
2016....................................................           0.075
2017....................................................           0.074
------------------------------------------------------------------------
Source: 2017 Ozone Design Values Report at https://www.epa.gov/air-trends/air-quality-design-values#report. Note that design values
  reported for a given year reflect data from that year and the two
  previous years, e.g., the design value for 2008 reflects data from
  2006-2008.

C. 2008 Ozone NAAQS and Clark County

    Meanwhile, in 2008, the EPA lowered the ozone NAAQS to a level of
0.075 ppm, 8-hour average (herein, the ``2008 ozone NAAQS''),\18\ and
in 2012, the EPA designated all of the hydrographic areas within the
State of Nevada as ``Unclassifiable/Attainment'' for the 2008 ozone
NAAQS.\19\ Because all the hydrographic areas located entirely, or
partially, within Clark County were designated as Unclassifiable/
Attainment for the 2008 ozone NAAQS, no RFP or attainment SIP revision
was required for any portion of the county, and the transportation
conformity requirements did not apply for that ozone NAAQS.
---------------------------------------------------------------------------

    \18\ 73 FR 16436 (March 27, 2008) and 40 CFR 50.15.
    \19\ 77 FR 30088 (May 21, 2012). Hydrographic areas are those
that are shown on the State of Nevada Division of Water Resources'
map titled ``Water Resources and Inter-basin Flows'' (September
1971).
---------------------------------------------------------------------------

    In 2015, the EPA issued a SIP Requirements Rule (SRR) for the 2008
ozone NAAQS (``2008 Ozone SRR'') that addressed implementation of the
2008 standards, including attainment dates, requirements for emissions
inventories, attainment and reasonable further progress (RFP)
demonstrations, among other SIP elements, as well as the transition
from the 1997 ozone NAAQS to the 2008 ozone NAAQS and associated anti-
backsliding requirements.\20\ The 2008 Ozone SRR revoked the 1997 ozone
NAAQS effective April 6, 2015.
---------------------------------------------------------------------------

    \20\ 80 FR 12264 (March 6, 2015) and 40 CFR part 51, subpart AA.
---------------------------------------------------------------------------

    The EPA's 2008 Ozone SRR was challenged, and on February 16, 2018,
the U.S. Court of Appeals for the D.C. Circuit (``D.C. Circuit'')
published its decision in South Coast Air Quality Management District
v. EPA (``South Coast II'') vacating certain portions of the 2008 Ozone
SRR, but upholding the EPA's revocation of the 1997 ozone NAAQS.\21\
The only aspect of the South Coast II decision that affects this
proposed action is the vacatur of the elimination of transportation
conformity in areas that were maintenance areas for the 1997 ozone
NAAQS at the time of revocation of the 1997 ozone NAAQS and were
designated as attainment for the 2008 ozone NAAQS, which the court
referred to as ``orphan maintenance areas.'' The Clark County 1997
ozone maintenance area is an orphan maintenance area. The 2008 ozone
SRR had provided that such areas are no longer required to determine
transportation conformity for the 1997 ozone NAAQS after the 1997 ozone
NAAQS is revoked.\22\ The court, however, held that transportation
conformity continues to apply for the 1997 ozone NAAQS in orphan
maintenance areas notwithstanding revocation of the 1997 ozone NAAQS.
---------------------------------------------------------------------------

    \21\ South Coast Air Quality Management District v. EPA, 882
F.3d 1138 (D.C. Cir. 2018) (``South Coast II''). The term ``South
Coast II'' is used in reference to the 2018 court decision to
distinguish it from a decision published in 2006 also referred to as
``South Coast.'' The earlier decision involved a challenge to the
EPA's Phase 1 implementation rule for the 1997 ozone NAAQS. South
Coast Air Quality Management District v. EPA, 472 F.3d 882 (D.C.
Cir. 2006).
    \22\ 80 FR 12264, 12284 (March 6, 2015).
---------------------------------------------------------------------------

    Following the South Coast II decision, the EPA issued guidance that
addresses how transportation conformity determinations can be made for
the 1997 ozone NAAQS in orphan maintenance areas, such as the Clark
County ozone maintenance area.\23\ In the guidance document, the EPA
explains that transportation conformity for transportation plans and
TIPs for the 1997 ozone NAAQS can be demonstrated without a regional
emissions analysis pursuant to 40 CFR 93.109(c).\24\ In the case of the
Clark County ozone maintenance area, while the transportation
conformity requirement continues to apply for the revoked 1997 ozone
NAAQS, RTC and DOT do not need to use the approved MOBILE6.2-based
budgets from the 2011 Ozone Maintenance Plan in a conformity
determination for the revoked 1997 ozone NAAQS because a regional
emissions analysis is not required for that determination.
---------------------------------------------------------------------------

    \23\ EPA, Office of Transportation and Air Quality,
``Transportation Conformity Guidance for the South Coast II Court
Decision,'' November 2018, EPA-420-B-18-050.
    \24\ Id., section 2.4.
---------------------------------------------------------------------------

D. 2015 Ozone NAAQS and Clark County

    In 2015, the EPA further lowered the ozone NAAQS to 0.070 ppm,
eight-hour average (herein the ``2015 ozone NAAQS'').\25\ In 2018, the
EPA designated the Las Vegas Valley portion of Clark County as a
``Marginal'' nonattainment area for the 2015 ozone NAAQS, effective
August 3, 2018.\26\ The Clark County nonattainment area for the 2015
ozone NAAQS is about half the size of the Clark County maintenance area
for the 1997 ozone NAAQS and includes only hydrographic area 212 (``Las
Vegas Valley'').
---------------------------------------------------------------------------

    \25\ 80 FR 65292 (October 26, 2015) and 40 CFR 50.19.
    \26\ 83 FR 25776 (June 4, 2018).
---------------------------------------------------------------------------

    The nonattainment area designation for Las Vegas Valley for the
2015 ozone NAAQS triggers the requirement for certain SIP revisions,
but, under CAA section 176(c)(6) and 40 CFR 93.102(d), transportation
conformity does not apply for the 2015 ozone NAAQS for one year
following the effective date of the nonattainment area designation
(referred to as the ``grace period''), or, in this case, does not apply
until August 3, 2019. However, to avoid a conformity ``lapse,'' a MPO
and DOT must make a conformity determination for the 2015 ozone NAAQS
for the applicable transportation plan and program before the end of
the 1-year grace period.\27\
---------------------------------------------------------------------------

    \27\ EPA, Office of Air Quality Planning and Standards,
``Transportation Conformity Guidance for 2015 Ozone NAAQS
Nonattainment Areas,'' June 2018, EPA-420-B-18-023. During a
conformity lapse, only certain projects can receive additional
federal funding or approvals to proceed (i.e., exempt projects,
project phases that were approved before the lapse, and
transportation control measures (TCMs) in approved SIPs) until the
area has both a conforming transportation plan and TIP.
---------------------------------------------------------------------------

    Under our Transportation Conformity Rule, the latest approved or
adequate emission budgets for a previous ozone

NAAQS (i.e., the 2008 or the 1997 ozone NAAQS) must be used in
conformity determinations for the 2015 ozone NAAQS until emission
budgets are established and found adequate or are approved for the 2015
ozone NAAQS.\28\ Since the latest approved or adequate emission budgets
for a previous ozone NAAQS for Clark County are the approved MOBILE6.2-
based budgets for the 1997 8-hour ozone NAAQS, the RTC and DOT must use
these budgets for conformity determinations for the 2015 ozone NAAQS
until they are replaced by updated budgets.
---------------------------------------------------------------------------

    \28\ 40 CFR 93.109(c)(2).
---------------------------------------------------------------------------

E. The MOVES Emission Model

    The MOVES model is the EPA's tool for estimating highway emissions.
The model is based on analyses of millions of emission test results and
considerable advances in the agency's understanding of vehicle
emissions. MOVES incorporates the latest emissions data, more
sophisticated calculation algorithms, increased user flexibility, new
software design, and significant new capabilities relative to those
reflected in the EPA's previous motor vehicle emission factor model,
MOBILE6.2.
    The EPA announced the release of MOVES2010 on March 2, 2010 (75 FR
9411) and approved the use of MOVES2010 in states other than California
for official SIP submissions to the EPA and for regional emissions
analyses for transportation conformity purposes. The EPA released
MOVES2014 on October 7, 2014 (79 FR 60343). MOVES2014 was a major
revision to MOVES2010 and incorporated new emissions and fleet data,
emission standards and functional improvements and features to the
model. The October 7, 2014 notice approved the use of MOVES2014 in
states outside of California for official SIP submissions to the EPA
and for regional emissions analyses for transportation conformity
purposes. In addition, the notice started a two-year grace period
before MOVES2014 was required to be used in new regional emissions
analyses for transportation conformity determinations outside of
California. Since October 7, 2016, MOVES2014 was required to be used
for new transportation conformity analyses outside California. In
November 2015, the EPA released MOVES2014a, a minor update to
MOVES2014.\29\
---------------------------------------------------------------------------

    \29\ In August 2018, the EPA released MOVES2014b to improve
estimates of emissions from nonroad mobile sources. MOBILE2014b does
not significantly change the on-road criteria pollutant emissions
results of MOVES2014 and is not considered a new model for SIP and
transportation conformity purposes.
---------------------------------------------------------------------------

III. What did the State submit?

    On October 31, 2018, NDEP submitted the 2018 Ozone Maintenance Plan
Revision (for the 1997 ozone NAAQS) to the EPA as a revision to the
Clark County portion of the Nevada SIP.\30\ Earlier that month, on
October 16, 2018, the Clark County Board of County Commissioners
adopted the 2018 Ozone Maintenance Plan Revision and forwarded the plan
to NDEP for adoption and submittal to the EPA.\31\ The 2018 Ozone
Maintenance Plan Revision updates certain elements of the 2011 Ozone
Maintenance Plan for the 1997 ozone NAAQS, including the emissions
inventories, the maintenance demonstration, and the MOBILE6.2-derived
budgets. The 2018 Ozone Maintenance Plan Revision also includes a
technical support document (appendix A of the plan revision) and
documentation of the public review process (appendix B of the plan
revision). These updated inventories and budgets in the 2018 Ozone
Maintenance Plan Revision are based on MOVES2014a. The budgets for the
1997 ozone NAAQS were developed so that the RTC would have updated
budgets available to use for transportation conformity determinations
with respect to the 2015 ozone NAAQS until budgets developed
specifically for the 2015 ozone NAAQS are adopted and found to be
adequate or approved.
---------------------------------------------------------------------------

    \30\ Letter, Greg Lovato, Administrator, NDEP to Mike Stoker,
Regional Administrator, EPA Region IX, October 31, 2018 with
enclosures.
    \31\ Clark County Board of County Commissioners Meeting, Meeting
Summary, pages 14 and 15 (of 19), October 16, 2018.
---------------------------------------------------------------------------

IV. Procedural Requirements for Adoption and Submittal of SIP Revisions

    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 the EPA's implementing regulations
in 40 CFR 51.102.
    The Clark County Board of County Commissioners and NDEP have
satisfied applicable statutory and regulatory requirements for
reasonable public notice and hearing prior to adoption and submittal of
the 2018 Ozone Maintenance Plan Revision. In the documentation included
as part of the October 31, 2018 SIP revision submittal,\32\ Clark
County DAQ provided evidence of the required public notice and
opportunity for public comment prior to the October 16, 2018 public
hearing and adoption of the 2018 Ozone Maintenance Plan Revision. We
find, therefore, that the submittal of the 2018 Ozone Maintenance Plan
Revision meets the procedural requirements for public notice and
hearing in CAA sections 110(a) and 110(l).
---------------------------------------------------------------------------

    \32\ Appendix B provides evidence that reasonable notice of a
public hearing was provided to the public and that a public hearing
was conducted prior to adoption. Specifically, notice of the
availability of, and opening of a 30-day comment period on, the
draft ozone maintenance plan revision was published on August 17,
2018 on the County's web page. No comments were submitted.
---------------------------------------------------------------------------

    CAA section 110(k)(1)(B) requires the EPA to determine whether a
SIP submittal is complete within 60 days of receipt. This section also
provides that any plan submittal that the EPA has not affirmatively
determined to be complete or incomplete will be deemed complete by
operation of law six months after the date of submittal. The EPA's SIP
completeness criteria are found in 40 CFR part 51, Appendix V. The 2018
Ozone Maintenance Plan Revision submission, dated October 31, 2018,
became complete by operation of law on April 30, 2019.

V. The EPA's Evaluation of the 2018 Ozone Maintenance Plan Revision

    The 2018 Ozone Maintenance Plan Revision is not a required
submittal but has been submitted to establish revised budgets
reflecting the most recent emissions models and planning estimates and
to thereby provide the basis for RTC and DOT to make future
transportation conformity determinations for transportation plans, TIPs
and projects with respect to the 2015 ozone NAAQS. We have reviewed the
2018 Ozone Maintenance Plan Revision for compliance with the relevant
requirements for maintenance plans under CAA section 175A and for
noninterference under CAA section 110(l), and we have evaluated the
budgets in the 2018 Ozone Maintenance Plan Revision for compliance with
the budget adequacy criteria in 40 CFR 93.118(e).
    CAA section 175A sets forth the elements of a maintenance plan for
areas seeking redesignation from nonattainment to attainment. We
interpret this section of the Act to require, in general, the following
core elements: Attainment inventory, maintenance demonstration,
monitoring network, verification of continued

attainment, and contingency plan.\33\ The 2018 Ozone Maintenance Plan
Revision updates two of the core elements of the approved 2011 Ozone
Maintenance Plan for the 1997 ozone NAAQS, the attainment inventory and
maintenance demonstration, and it also updates the budgets.
---------------------------------------------------------------------------

    \33\ John Calcagni, Director, Air Quality Management Division,
EPA Office of Air Quality Planning and Standards, memo titled
``Procedures for Processing Requests to Redesignate Areas to
Attainment,'' September 4, 1992.
---------------------------------------------------------------------------

    CAA section 110(l) applies to all SIP revisions, and under that
section, the EPA shall not approve any SIP revision if the revision
would interfere with any applicable requirement concerning attainment
and reasonable further progress or any other applicable requirement of
the CAA.

A. Revised Attainment Inventory

    A maintenance plan for the 1997 ozone NAAQS must include an
inventory of emissions of ozone precursors (VOC and NOX) in
the area to identify a level of emissions that are sufficient to attain
the 1997 ozone NAAQS. This inventory must be consistent with the EPA's
most recent guidance on emissions inventories for nonattainment areas
available at the time and should represent emissions during the time
period associated with the monitoring data showing attainment. The
inventory must also be comprehensive, including emissions from
stationary point sources, area sources, nonroad mobile sources, and on-
road mobile sources, and must be based on actual ``ozone season data''
(i.e., summertime) emissions.
    Clark County DAQ selected 2008 as the year for the attainment
inventory in the 2011 Ozone Maintenance Plan. The attainment year
inventory in the 2011 Ozone Maintenance Plan is comprehensive in that
it includes estimates of summertime average weekday VOC and
NOX emissions from all of the relevant source categories,
which the plan divides among point sources,\34\ nonpoint sources,\35\
commercial aviation, federal aviation (i.e., Nellis Air Force Base),
on-road mobile, nonroad mobile, and biogenic \36\ sources.\37\ The 2018
Ozone Maintenance Plan Revision includes a comprehensive update to the
2008 attainment inventory but, to the extent that the original
estimates (i.e., from 2011 Ozone Maintenance Plan) are based on actual
reported emissions or activity levels for year 2008, there is little
change in the related emissions estimate. Appendix A to the 2018 Ozone
Maintenance Plan Revision contains source-specific descriptions of
emission calculation procedures and sources of input data used for the
update.
---------------------------------------------------------------------------

    \34\ The 2018 Ozone Maintenance Plan Revision uses the term,
``point sources,'' to refer to those stationary source facilities
that are required to report their emissions to Clark County DAQ or
NDEP.
    \35\ The 2018 Ozone Maintenance Plan Revision uses the term,
``nonpoint sources,'' to refer to those stationary and area sources
that fall below point source reporting levels and that are too
numerous or small to identify individually.
    \36\ For the 2018 Ozone Maintenance Plan Revision, ``biogenic
sources'' include agricultural crops; lawn grass; forests that
produce isoprene, monoterpene, alpha-pinene, and other VOC
emissions; and soils that generate trace amounts of NOX.
    \37\ See Table 2-1 in the 2018 Ozone Maintenance Plan Revision.
---------------------------------------------------------------------------

    Table 2 below compares the attainment inventory from the 2011 Ozone
Maintenance Plan with the corresponding inventory from the 2018 Ozone
Maintenance Plan Revision. As shown in Table 2, the change in the
attainment inventory in the 2018 Ozone Maintenance Revision is
primarily due to the update to the on-road mobile source category and
the nonpoint source category.

                                       Table 2--2008 Attainment Inventory
                                       [Average summer weekday, tons/day]
----------------------------------------------------------------------------------------------------------------
                                                           NOX emissions                   VOC emissions
                                                 ---------------------------------------------------------------
                 Source category                    2011 Ozone      2018 Ozone      2011 Ozone      2018 Ozone
                                                    Maintenance     Maintenance     Maintenance     Maintenance
                                                       Plan        Plan Revision       Plan        Plan Revision
----------------------------------------------------------------------------------------------------------------
Point source....................................           28.73           28.97            1.32            1.50
Nonpoint source.................................            5.41             6.6           57.07           67.56
Commercial aviation.............................           11.41           11.41            2.60            2.60
Federal aviation................................            1.27            1.27            0.79            0.79
On-road mobile..................................           68.46           89.50           65.08           42.46
Nonroad mobile..................................           43.28           40.63           42.91           42.07
Biogenic........................................            5.00            5.00          132.00          132.00
                                                 ---------------------------------------------------------------
    Total.......................................          163.56          183.38          301.77          288.98
----------------------------------------------------------------------------------------------------------------
Sources: 2011 Ozone Maintenance Plan, tables 6-2 and 6-3; 2018 Ozone Maintenance Plan Revision, table 2-1.

    With respect to on-road mobile source emissions, Clark County DAQ
updated the emissions estimates using the SMOKE-MOVES approach, which
incorporates MOVES2014a model emission rates, Sparse Matrix Operator
Kernel Emissions (SMOKE) modeling,\38\ RTC travel demand modeling, and
Highway Performance Monitoring System (HPMS) data from the Nevada
Department of Transportation.\39\ Clark County DAQ selected the SMOKE-
MOVES approach to be consistent with the EPA's approach in developing
the National Emissions Inventory (NEI), as well as with the EPA's
modeling platform. This approach is also consistent with the one used
in Clark County's photochemical modeling applications. In contrast, the
2011 Ozone Maintenance Plan's on-road mobile source emissions were
estimated using the CONCEPT MV emissions model \40\ and EPA's MOBILE6.2
emissions factors. Generally, on-road mobile source emissions estimates
made using MOVES2014a are higher for NOX

and lower for VOC relative to those made using MOBILE6.2. With respect
to nonpoint emissions sources, the change in the 2008 emissions
inventory is largely due to the use of the SMOKE model.
---------------------------------------------------------------------------

    \38\ SMOKE is an emission-generating and processing model used
in developing hourly gridded emissions for photochemical modeling.
The EPA has integrated the MOVES model with the SMOKE model with a
set of integration software tools that allows the MOVES emission
rate model to automatically run numerous iterations to generate the
most accurate modeling results. The SMOKE-MOVES integrated approach
takes advantage of gridded hourly temperature and humidity
information from the Weather Research and Forecasting (WRF)
meteorology model used for air quality modeling.
    \39\ 2018 Ozone Maintenance Plan Revision, Appendix A, page A-2.
    \40\ ``CONCEPT'' refers to the CONsolidated Community Emissions
Processor Tool (CONCEPT) and ``MV'' refers to the motor vehicle
module of the CONCEPT model.
---------------------------------------------------------------------------

    Based on our review of the emissions inventories (and related
documentation) from the 2018 Ozone Maintenance Plan Revision, we find
that the inventories for 2008 are comprehensive, that the methods and
assumptions used by Clark County DAQ to update the 2008 emission
inventory are reasonable, and that the inventories reasonably estimate
actual ozone season emissions in the 2008 attainment year. Moreover, we
find that the 2008 emissions inventories in the Ozone Maintenance Plan
reflect the latest planning assumptions and emissions models available
at the time the 2018 Ozone Maintenance Plan Revision was developed.

B. Revised Maintenance Demonstration

    CAA section 175A(a) requires that the maintenance plan ``provide
for the maintenance of the national primary ambient air quality
standard for such air pollutant in the area concerned for at least 10
years after the redesignation.'' Generally, a state may demonstrate
maintenance of the ozone NAAQS by either showing that future emissions
will not exceed the level of the attainment inventory or by modeling to
show that the future mix of sources and emissions rates will not cause
a violation of the NAAQS.
    The 2018 Ozone Maintenance Plan Revision uses the same method as
the 2011 Ozone Maintenance Plan to demonstrate continued maintenance of
the 1997 ozone NAAQS. The 2018 Ozone Maintenance Plan Revision
demonstrates maintenance through the initial 10-year period after
redesignation by showing that emissions in 2015 and 2022 would be less
than those in the 2008 attainment year.
    To provide the basis for the comparison of future emissions with
the updated attainment year (2008) emissions, Clark County DAQ updated
the 2015 and 2022 emissions inventories using the SMOKE-MOVES approach
for the on-road mobile sources as described above for the update to the
2008 attainment year emissions inventory and by incorporating more
recent emissions and travel demand data. Tables 3 and 4 below compare
the NOX and VOC emissions inventories, respectively, for
2015 and 2022 from the 2018 Ozone Maintenance Plan Revision with the
corresponding values from the 2011 Ozone Maintenance Plan.

                  Table 3--Comparison of NOX Inventories Associated With Approved and Revised Maintenance Plan for the 1997 Ozone NAAQS
                                                            [Tons per average summer weekday]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           2011 Ozone  Maintenance Plan    2018 Ozone  Maintenance Plan           Net  change \b\
                                                                        \a\                          Revision            -------------------------------
                     Source category                     ----------------------------------------------------------------
                                                               2015            2022            2015            2022            2015            2022
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stationary and Area (point and nonpoint)................              37              38              18              17             -19             -21
On-road.................................................              35              23              64              27             +29              +4
Nonroad (including aviation)............................              47              51              41              37              -6             -14
Biogenic................................................               5               5               5               5               0               0
Emission Reduction Credits..............................              22              22              22              22               0               0
                                                         -----------------------------------------------------------------------------------------------
    Totals \c\..........................................             146             139             150             109              +4             -30
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The emissions shown for the approved ozone plan are from Table 6-3 of Clark County's 2011 Ozone Maintenance Plan.
\b\ For the net change, a negative number indicates a reduction in emissions, and a positive number indicates an increase in emissions relative to the
  corresponding figure in the 2011 Ozone Maintenance Plan.
\c\ Because of rounding conventions, totals may not reflect individual subcategories.

                  Table 4--Comparison of VOC Inventories Associated With Approved and Revised Maintenance Plan for the 1997 Ozone NAAQS
                                                            [Tons per average summer weekday]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           2011 Ozone  Maintenance Plan    2018 Ozone  Maintenance Plan           Net  change \b\
                                                                        \a\                          Revision            -------------------------------
                     Source category                     ----------------------------------------------------------------
                                                               2015            2022            2015            2022            2015            2022
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stationary and Area (point and nonpoint)................              68              78              63              62              -5             -16
On-road.................................................              45              37              33              17             -12             -20
Nonroad (including aviation)............................              36              35              35              32              -1              -3
Biogenic................................................             132             132             132             132               0               0
Emission Reduction Credits..............................              <1              <1              <1              <1               0               0
                                                         -----------------------------------------------------------------------------------------------
    Totals \c\..........................................             282             282             263             244             -19             -38
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The emissions shown for the approved ozone plan are from Table 6-3 of Clark County's 2011 Ozone Maintenance Plan.
\b\ For the net change, a negative number indicates a reduction in emissions, and a positive number indicates an increase in emissions relative to the
  corresponding figure in the 2011 Ozone Maintenance Plan.
\c\ Because of rounding conventions, totals may not reflect individual subcategories.

    As shown in tables 3 and 4, total emissions for 2015 and 2022 in
the 2018 Ozone Maintenance Plan Revision are lower than the
corresponding emissions in the 2011 Ozone Maintenance Plan with the
exception of a 4 tpd higher estimate in 2015 for NOX. With
respect to the on-road mobile sources, the update results in higher
NOX emissions but lower VOC emissions and reflects primarily
the differences in the emissions rates calculated using MOVES2014a
relative to those calculated using MOBILE6.2. The on-road mobile source
emission estimates in the 2018 Ozone Maintenance Plan Revision reflect
the most recent published data concerning vehicle registration data,
vehicle miles traveled (VMT) temporal distribution, VMT mix profiles,
vehicle speeds and travel demand forecasts from RTC.\41\ The higher
estimates for NOX from on-road mobile sources are offset by
decreases in the actual reported emissions for point source emissions
compared to their projected emissions in the 2011 Ozone Maintenance
Plan (which includes the shutdown of the Reid Gardner coal-fired power
plant). Other significant differences include: (1) A reduction in
commercial aviation emissions because the Sloan Regional Heliport and
South County Ivanpah Airport projects, which had been assumed for the
2011 Ozone Maintenance Plan, have not been constructed and (2)
reductions in nonpoint source emission projection factors.\42\
---------------------------------------------------------------------------

    \41\ Key references used by Clark County DAQ include Eastern
Research Group, Inc.'s ``Clark County On-Road Vehicle Classification
Study,'' final report, June 29, 2018 and the Coordinating Research
Council, Inc.'s ``Improvement of Default Inputs for MOVES and SMOKE-
MOVES,'' final report, February 2017.
    \42\ Clark County projected emissions from 2014 NEI data with
factors derived from the 2011-2023 annual rate of change for all
nonpoint sectors from EPA's 2011 Version 6 Air Emissions Modeling
Platform. Nonpoint source emissions in the 2011 Ozone Maintenance
Plan were based on the 2008 NEI and higher growth correlated to
population and economic growth factors.
---------------------------------------------------------------------------

    Based on our review of the methods, assumptions, and data sources,
as described in Appendix A to the 2018 Ozone Maintenance Plan Revision,
and briefly summarized above, we find that Clark County DAQ's estimates
for 2015 and 2022 for the various source categories to be based on the
best available emissions models and data sources, and thus to provide a
reasonable basis upon which to evaluate whether the area will maintain
the 1997 ozone NAAQS through 2022.
    A state may choose to allocate all or a portion of the safety
margin \43\ under our transportation conformity rule so long as such
margins are explicitly quantified in the applicable plan and are shown
to be consistent with attainment or maintenance of the NAAQS (whichever
is relevant to the particular plan).\44\ For the 2018 Ozone Maintenance
Plan Revision, Clark County DAQ allocated 80 percent of the safety
margin for NOX and VOC in 2015 and 2022 to the projected on-
road emissions estimates for NOX and VOC.
---------------------------------------------------------------------------

    \43\ In this context, ``safety margin'' means the amount by
which the total projected emissions from all sources of a given
pollutant are less than the total emissions that would satisfy the
applicable requirements for reasonable further progress, attainment
or maintenance. With respect to the 2018 Ozone Maintenance Plan
Revision, the safety margin is the difference between the projected
emissions in 2015 and 2022 of NOX and VOC and the actual
emissions of NOX and VOC in the 2008 attainment year.
    \44\ See 40 CFR 93.124(a).
---------------------------------------------------------------------------

    Table 5 below summarizes the revised maintenance demonstration
(including the safety margins) for the 1997 ozone NAAQS. As shown in
Table 5, the revised emission estimates for NOX and VOC in
2015 and 2022 (including the safety margins) would remain below the
corresponding 2008 attainment levels throughout the 10-year maintenance
period and thereby adequately demonstrate maintenance through that
period.

                         Table 5--Revised Maintenance Demonstration for 1997 Ozone NAAQS
----------------------------------------------------------------------------------------------------------------
                                                            Emissions  (average summer weekday, tpd)
                                               -----------------------------------------------------------------
              Source description                 Attainment  (2008)           2015                  2022
                                               -----------------------------------------------------------------
                                                   NOX        VOC        NOX        VOC        NOX        VOC
----------------------------------------------------------------------------------------------------------------
Projected Emissions--Excluding On-Road Mobile       93.88     246.52      85.81     229.82      81.71     227.06
 Sources......................................
Projected On-Road Mobile Source Emissions.....      89.50      42.46      64.30      33.04      27.02      17.12
Allocation of Portion of Safety Margin to On-           0          0      26.62      20.90      59.72      35.84
 Road.........................................
Total Emissions (with Safety Margins).........     183.38     288.98     176.73     283.76     168.45     280.02
Maintenance Demonstrated?.....................  .........  .........        Yes        Yes        Yes        Yes
Motor Vehicle Emissions Budget (Projected On-       89.50      42.46      90.92      53.94      86.74      52.96
 Road Plus Safety Margin).....................
----------------------------------------------------------------------------------------------------------------
Source: 2018 Ozone Maintenance Plan Revision, Tables 2-1, 2-2 and 3-1. Note: Maintenance is demonstrated where
  future emissions (with the safety margins) are less than the corresponding attainment inventory emissions.

C. Revised Motor Vehicle Emissions Budgets

    Section 176(c) of the CAA requires federal actions in nonattainment
and maintenance areas to conform to the SIP's goals of eliminating or
reducing the severity and number of violations of the NAAQS and
achieving timely attainment of the standards. Conformity to the SIP's
goals means that such actions will not: (1) Cause or contribute to
violations of a NAAQS, (2) worsen the severity of an existing
violation, or (3) delay timely attainment of any NAAQS or any interim
milestone.
    Under the transportation conformity rule, MPOs in nonattainment and
maintenance areas coordinate with state and local air quality and
transportation agencies, the EPA, the FHWA, and the FTA to demonstrate
that an area's regional transportation plans and TIPs conform to the
applicable SIP. This demonstration is typically done by showing that
estimated emissions from existing and planned highway and transit
systems are less than or equal to the budgets contained in all control
strategy or maintenance SIPs. Budgets are generally established for
specific years and specific pollutants or precursors. Maintenance ozone
plans should identify budgets for on-road emissions of ozone precursors
(NOX and VOC) in the area for the last year of the
maintenance period. Budgets may also be specified for additional years
during the maintenance period.
    For budgets to be approvable, they must meet the EPA's adequacy
criteria (40 CFR 93.118(e)(4) and (5)) and comply with all pertinent
SIP requirements. With respect to maintenance plans, to meet these
requirements, the budgets must be consistent with the maintenance plan
and reflect all the motor vehicle control measures contained in the
maintenance

demonstration.\45\ The EPA's process for determining adequacy of a
budget consists of three basic steps: (1) Providing public notification
of a SIP submission; (2) providing the public the opportunity to
comment on the budget during a public comment period; and, (3) making a
finding of adequacy or inadequacy.\46\ We will complete the adequacy
review of the budgets in the 2018 Ozone Maintenance Plan Revision
concurrent with our final action on the 2018 Ozone Maintenance Plan
Revision. The EPA is not required under its transportation conformity
rule to find budgets adequate prior to proposing approval of them.\47\
---------------------------------------------------------------------------

    \45\ 40 CFR 93.118(e)(4)(iii), (iv) and (v). For more
information on the transportation conformity requirements and
applicable policies on budgets, please visit our transportation
conformity website at: http://www.epa.gov/otaq/stateresources/transconf/index.htm.
    \46\ 40 CFR 93.118(f)(2).
    \47\ Under the transportation conformity regulations, the EPA
may review the adequacy of submitted motor vehicle emission budgets
simultaneously with the EPA's approval or disapproval of the
submitted implementation plan. 40 CFR 93.118(f)(2).
---------------------------------------------------------------------------

    The 2018 Ozone Maintenance Plan Revision includes revised budgets
for VOC and NOX for years 2008, 2015 and the last year of
the initial maintenance period, i.e., 2022. The revised budgets from
the 2018 Ozone Maintenance Plan Revision are shown in Table 6 below and
compared with the corresponding budgets from the approved 2011 Ozone
Maintenance Plan. As noted previously, Clark County DAQ developed the
revised budgets using the latest emissions model (MOVES2014a) available
at the time the 2018 Ozone Maintenance Plan Revision was being
developed, and the most recent travel activity projections provided by
the NDOT and RTC. As such, we find that the revised budgets reflect the
most recent planning forecasts and are based on the most recent
emission factor data and approved calculation methods. Clark County DAQ
included 80% of the safety margin in the budgets. In this context, the
term ``safety margin'' refers to the difference between the updated
emissions inventories in the 2018 Ozone Maintenance Plan Revision for
years 2015 and 2022 and the updated attainment (2008) emissions
inventory in the plan revision.

                                  Table 6--Ozone Motor Vehicle Emission Budgets
                                       [Average summer weekday, tons/day]
----------------------------------------------------------------------------------------------------------------
                                                    2011 Ozone Maintenance Plan     2018 Ozone Maintenance Plan
                                                 --------------------------------            Revision
                      Year                                                       -------------------------------
                                                        NOX             VOC             NOX             VOC
----------------------------------------------------------------------------------------------------------------
2008............................................           68.46           65.08           89.50           42.46
2015............................................           34.69           45.32           90.92           53.94
2022............................................           23.15           36.71           86.74           52.96
----------------------------------------------------------------------------------------------------------------
Sources: 2011 Ozone Maintenance Plan, Table 7-1; 2018 Ozone Maintenance Plan Revision, Table 3-1.

    As documented in a May 22, 2019 memorandum to the docket for this
rulemaking, we find that the budgets in the 2018 Ozone Maintenance Plan
Revision meet each adequacy criterion.\48\ We have completed our
detailed review of the 2018 Ozone Maintenance Plan Revision and find
them acceptable. We have also reviewed the budgets in the 2018 Ozone
Maintenance Plan Revision and found that they are consistent with the
revised maintenance demonstration; are based on control measures that
have already been adopted and implemented; and meet all other
applicable statutory and regulatory requirements including the adequacy
criteria in 40 CFR 93.1118(e)(4) and (5). Therefore, we are proposing
to find adequate and conditionally approve the 2008, 2015 and 2022
budgets in the 2018 Ozone Maintenance Plan Revision. If we finalize our
adequacy determination and conditional approval of the revised budgets
in the 2018 Ozone Maintenance Plan Revision, as proposed, they will
replace the budgets for the 1997 ozone NAAQS from the 2011 Ozone
Maintenance Plan that we previously found adequate and approved for use
in transportation conformity determinations. The proposed approval of
the budgets is conditional because it is based on commitments by NDEP
and Clark County DAQ to submit a SIP revision within one year of final
conditional approval to reduce the safety margin allocations to avoid
interference with reasonable further progress or attainment of the 2008
and 2015 ozone NAAQS. For more information on why the reduction of the
safety margin is needed, see the following section of this notice.
---------------------------------------------------------------------------

    \48\ Memorandum from Karina O'Connor, Air Planning Office, EPA
Region IX, to Air Plan Approval; Revisions to the Clark County Ozone
Maintenance Plan, dated May 22, 2019.
---------------------------------------------------------------------------

D. CAA Section 110(l) Evaluation

    In relevant part, CAA section 110(l) provides that the EPA shall
not approve a SIP revision that would interfere with any applicable
requirement concerning attainment or RFP of any of the NAAQS or any
other applicable requirement of the CAA. The 2018 Ozone Maintenance
Plan Revision would establish budgets that are larger than those that
are currently approved from the 2011 Ozone Maintenance Plan. Thus,
approval of the 2018 Ozone Maintenance Plan Revision would accommodate
a higher level of VOC and NOX emissions from on-road mobile
source emissions than would otherwise be allowed under the existing
budgets. In the following paragraphs, we evaluate the higher level of
VOC and NOX emissions with respect to the potential for
interference with RFP and attainment of the NAAQS for which VOC and
NOX are precursors, namely, the 2008 and 2015 ozone NAAQS
and the 2006 and 2012 PM2.5 NAAQS.\49\
---------------------------------------------------------------------------

    \49\ As a general matter, NOX is also considered a
precursor for PM10. However, in approving the Las Vegas
Valley Serious Area PM10 Plan, the EPA determined that
major stationary sources of PM10 precursors do not
contribute significantly to elevated ambient PM10
concentrations in Las Vegas Valley. 69 FR 32273 (June 9, 2004).
Moreover, the approved Las Vegas Valley PM10 Maintenance
Plan relies on direct PM10 control measures (rather than
PM10 precursor controls) to demonstrate maintenance of
the PM10 NAAQS within Las Vegas Valley. 79 FR 42258 (July
21, 2014) (proposed PM10 redesignation and approval of
related maintenance plan) and 79 FR 60078 (October 6, 2014) (final
PM10 redesignation and approval of related maintenance
plan).
---------------------------------------------------------------------------

    2008 Ozone NAAQS. In 2012, the EPA designated all the hydrographic
areas within the State of Nevada as unclassifiable/attainment for the
0.075 ppm 2008 ozone NAAQS based on ambient ozone concentration data
for

years 2009-2011.\50\ After the original designation, the 8-hour ozone
design values within Clark County exceeded the 2008 ozone NAAQS for a
few years but, since 2015, the design values have returned to
attainment levels for the 2008 ozone NAAQS. See Table 1 above. Thus,
emissions of VOC and NOX in 2015 represent conditions under
which Clark County meets the 2008 ozone NAAQS. As updated in the 2018
Ozone Maintenance Plan Revision, summertime weekday average emissions
in 2015 were approximately 262 tpd of VOC and 128 tpd of
NOX.\51\ Including the safety margin allocations to the on-
road emissions estimates, the 2018 Ozone Maintenance Plan Revision
allows for 280 tpd of VOC and 168 tpd of NOX emissions in
2022, i.e., a higher level of VOC and NOX emissions than is
consistent with continued attainment of the 2008 ozone NAAQS.
---------------------------------------------------------------------------

    \50\ Letter from Jared Blumenfeld, Regional Administrator, EPA
Region IX, to Brian Sandoval, Governor, State of Nevada, dated
December 9, 2011.
    \51\ Assumes that no emission reduction credits (ERCs) were used
in 2015.
---------------------------------------------------------------------------

    However, in recognition of the need to avoid interference with
attainment of the 2008 ozone NAAQS and progress toward attainment of
the 2015 ozone NAAQS, NDEP and Clark County DAQ have committed to
submit a SIP revision to remove the safety margin allocations to the
2015 budgets and to reduce the safety margin allocations to the 2022
budgets such that total estimated emission in 2022 (with the
allocations) would not exceed actual emissions in year 2017. As shown
in Table 1 above, the design value in year 2017 was 0.074 ppm, which is
consistent with attainment of the 0.075 ppm 2008 ozone NAAQS.
    Based on the commitments by NDEP and Clark County DAQ, the total
projected emissions (with the reduced safety margin allocations) in
year 2022 would be less than the actual emissions estimated for year
2017, a year in which the 2008 ozone NAAQS was attained in Clark
County. Therefore, the 2018 Ozone Maintenance Plan, as revised
consistent with NDEP's and Clark County DAQ's commitments, would not
interfere with attainment of the 2008 ozone NAAQS in Clark County.
    2015 Ozone NAAQS. In 2018, the EPA designated the Las Vegas Valley
(i.e., hydrographic area #212) as a Marginal nonattainment area for the
0.070 ppm 2015 ozone NAAQS based on ambient ozone concentration data
for years 2015-2017.\52\ The 2017 ozone design value is 0.074 ppm, and
VOC and NOX emissions in 2017 are estimated (based on
interpolating the 2015 and 2022 updated inventories in the 2018 Ozone
Maintenance Plan Revision) to be approximately 257 tpd and 116 tpd,
respectively.\53\ To attain the 0.070 ppm 2015 ozone NAAQS by the
applicable Marginal area attainment date, i.e., by August 3, 2021, VOC
and NOX emissions must decrease relative to those in 2017.
With the allocation of the safety margin to the on-road emissions
estimates, the 2018 Ozone Maintenance Plan Revision would allow for VOC
and NOX emissions that are greater than those in 2017.
---------------------------------------------------------------------------

    \52\ EPA, ``Nevada, Las Vegas Nonattainment Area, Final Area
Designations for the 2015 Ozone National Ambient Air Quality
Standards, Technical Support Document (TSD).''
    \53\ Assumes that no ERCs were used in 2017.
---------------------------------------------------------------------------

    However, based on the commitments by NDEP and Clark County DAQ
described above for the 2008 ozone NAAQS, the total projected emissions
(with the reduced safety margin allocations) in year 2022 would be less
than the actual emissions estimated for year 2017, the base year for
implementation of the 2015 ozone NAAQS. Therefore, the 2018 Ozone
Maintenance Plan, as revised consistent with NDEP's and Clark County
DAQ's commitments, would not interfere with RFP towards attainment of
the 2015 ozone NAAQS.
    2006 and 2012 PM2.5 NAAQS. The EPA has designated the State of
Nevada, on a hydrographic area basis, as unclassifiable/attainment for
both the 35 [micro]g/m\3\, 24-hour average, 2006 PM2.5 NAAQS
and the 12.0 [micro]g/m\3\, annual average, 2012 PM2.5
NAAQS.\54\ The design values for 24-hour average PM2.5
concentrations have ranged from 19 to 26 [micro]g/m\3\ over the 2008-
2017 period, well below the corresponding NAAQS of 35 [micro]g/
m\3\.\55\ With respect to annual average PM2.5
concentrations, the design values have ranged from 7.7 to 10.3
[micro]g/m\3\ over that same period, i.e., well below the corresponding
NAAQS of 12.0 [micro]g/m\3\.\56\ Thus, since at least 2008, ambient
PM2.5 concentrations have been well within the applicable
NAAQS, and given that the VOC and NOX emissions that would
be allowed under the 2018 Ozone Maintenance Plan Revision (including
the safety margin allocations to on-road emissions) would be less than
those that occurred in 2008, approval of the 2018 Ozone Maintenance
Plan Revision would not interfere with attainment of the 2006 or 2012
PM2.5 NAAQS in Clark County.
---------------------------------------------------------------------------

    \54\ 40 CFR 81.329.
    \55\ 2017 PM2.5 Design Values Report at https://www.epa.gov/air-trends/air-quality-design-values#report. The 24-hour
PM2.5 NAAQS design value is the 3-year average of annual
98th percentile 24-hour average values recorded at each monitoring
site, and the 24-hour PM2.5 design value for the area is
the highest design value among the monitoring sites.
    \56\ Id. The annual PM2.5 NAAQS design value is the
3-year average of annual mean concentrations recorded at each
monitoring site, and the annual PM2.5 design value for
the area is the highest design value among the monitoring sites.
---------------------------------------------------------------------------

VI. Proposed Action and Request for Public Comment

    For the reasons discussed above, under CAA section 110(k)(4), the
EPA is proposing to conditionally approve the 2018 Ozone Maintenance
Plan Revision submitted by NDEP on October 31, 2018 as a revision for
the Clark County portion of the Nevada SIP. In so proposing, we find
that the 2011 Ozone Maintenance Plan, as revised by the updated
attainment inventory and maintenance demonstration in the 2018 Ozone
Maintenance Plan Revision, continues to provide for maintenance of the
1997 ozone NAAQS and, upon fulfillment of the commitments made by NDEP
and Clark County DAQ to reduce the safety margin allocations to the
budgets, will not interfere with RFP or attainment of the other NAAQS
in Clark County. In proposing conditional approval of the 2018 Ozone
Maintenance Plan Revision, the EPA is also proposing to find adequate
and conditionally approve the updated budgets for 2008, 2015 and 2022
for the 1997 ozone NAAQS (shown in Table 6 of this document) based on
our conclusion that the updated budgets meet the applicable
transportation conformity requirements.
    The proposed approval of the 2018 Ozone Maintenance Plan Revision
is conditional because it is based on commitments from NDEP and the
Clark County DAQ to submit a SIP revision within one year of final
conditional approval.\57\ The purpose of the future SIP revision is to
reduce the safety margin allocations to the budgets to ensure that the
2018 Ozone Maintenance Plan Revision, as revised to reduce the safety
margin allocations, will not interfere with reasonable further progress
or attainment of the 2008 and 2015 ozone NAAQS.
---------------------------------------------------------------------------

    \57\ Letter from Jodi Bechtel, Assistant Director, Clark County
DAQ, to Greg Lovato, Administrator, NDEP, dated June 14, 2019; and
letter from Greg Lovato, Administrator, NDEP, to Elizabeth Adams,
Director, Air Division, EPA Region IX, dated June 21, 2019.
---------------------------------------------------------------------------

    Lastly, if the EPA takes final action to approve conditionally the
2018 Ozone Maintenance Plan Revision as proposed, the revised budgets
will replace the existing approved budgets from the 2011 Ozone
Maintenance Plan, and RTC and DOT must use the revised budgets for
future transportation conformity determinations.

    The EPA is soliciting public comments on the issues discussed in
this document or on other relevant matters. We will accept comments
from the public on this proposal for the next 30 days. We will consider
these comments before taking final action.

VII. 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
conditionally a state plan 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 Orders
12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21,
2011);
     Is not an Executive Order 13771 (82 FR 9339, February 2,
2017) regulatory action because SIP approvals are exempted under
Executive Order 12866;
     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 proposed 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).

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental regulations, Nitrogen dioxide, Ozone,
Reporting and recordkeeping requirements, Volatile organic compounds.

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

    Dated: June 27, 2019.
Deborah Jordan,
Acting Regional Administrator, EPA Region IX.
[FR Doc. 2019-14630 Filed 7-10-19; 8:45 am]
 BILLING CODE 6560-50-P


[Federal Register Volume 81, Number 75 (Tuesday, April 19, 2016)]
[Notices]
[Pages 22977-22978]
[FR Doc No: 2016-09036]

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

ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OAR-2015-0072; FRL-9944-25-OAR]

Release of the Draft Integrated Review Plan for the National
Ambient Air Quality Standards for Particulate Matter

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability and public comment period.

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

SUMMARY: The Environmental Protection Agency (EPA) is announcing the
availability for public review of the draft document titled Draft
Integrated Review Plan for the National Ambient Air Quality Standards
for Particulate Matter (draft IRP). The draft IRP contains the current
plans for the review of the air quality criteria for particulate matter
(PM) and the primary and secondary national ambient air quality
standards (NAAQS) for PM. The primary PM NAAQS are set to protect the
public health and the secondary PM NAAQS are set to protect the public
welfare from exposures to PM in ambient air.

DATES: Comments should be received on or before June 23, 2016.

ADDRESSES: The draft IRP will be available primarily via the Internet
at https://www3.epa.gov/ttn/naaqs/standards/pm/s_pm_index.html. Submit
your comments, identified by Docket ID No. EPA-HQ-OAR-2015-0072, to the
Federal eRulemaking Portal: http://www.regulations.gov. Follow the
online instructions for submitting comments. Once submitted, comments
cannot be edited or withdrawn. 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 for which 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, the full EPA public comment
policy, information about CBI or multimedia submissions, and general
guidance on making effective comments, please visit http://www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Dr. Scott Jenkins, Office of Air
Quality Planning and Standards (mail code C504-06), U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711; telephone number:
919-541-1167; fax number:<PHONE_NUMBER>; email<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

I. General Information

A. What should I consider as I prepare my comments for the EPA?

    1. Submitting CBI. Do not submit this information to EPA through
http://www.regulations.gov or email. Clearly mark the part or all of
the information that you claim to be CBI. For CBI information in a disk
or CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM
as CBI and then identify electronically within the disk or CD-ROM the
specific information that is claimed as CBI. In addition to one
complete version of the comment that includes information claimed as
CBI, a copy of the comment that does not contain the information
claimed as CBI must be submitted for inclusion in the public docket.
Information so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2.
    2. Tips for Preparing your Comments. When submitting comments,
remember to:
     Identify the rulemaking by docket number and other
identifying information (subject heading, Federal Register date and
page number).
     Follow directions. The agency may ask you to respond to
specific questions or organize comments by reference a Code of Federal
Regulations (CFR) part or section number.
     Explain why you agree or disagree; suggest alternative and
substitute language for your requested changes.
     Describe any assumption and provide any technical
information and/or data that you used.
     If you estimate potential costs or burdens, explain how
you arrived at your estimate in sufficient detail to allow for it to be
reproduced.
     Provide specific examples to illustrate your concerns and
suggest alternatives.
     Explain your views as clearly as possible, avoiding the
use of profanity or personal threats.
     Make sure to submit your comments by the comment period
deadline identified.
II. Information Specific to This Document
    Two sections of the Clean Air Act (CAA) govern the establishment
and revision of the NAAQS. Section 108 (42 U.S.C. 7408) directs the
Administrator to identify and list certain air pollutants and then to
issue air quality criteria for those pollutants. The Administrator is
to list those air pollutants that in his or her ``judgment, cause or
contribute to air pollution which may reasonably be anticipated to
endanger public health or welfare;'' ``the presence of which in the
ambient air results from numerous or diverse mobile or stationary
sources;'' and ``for which . . . [the Administrator] plans to issue air
quality criteria. . . .'' Air quality criteria are intended to
``accurately reflect the latest scientific knowledge useful in
indicating the kind and extent of all identifiable effects on public
health or welfare which may be expected from the presence of [a]
pollutant in the ambient air. . . .'' (42 U.S.C. 7408(b)). Under
section 109 (42 U.S.C. 7409), the EPA establishes primary (health-
based) and secondary (welfare-based) NAAQS for pollutants for which air
quality criteria are issued. Section 109(d) requires periodic review
and, if appropriate, revision of existing air quality criteria. Revised
air quality criteria reflect advances in scientific knowledge on the
effects of the pollutant on public health or welfare. The EPA is also
required to periodically review and, if appropriate, revise the NAAQS
based on the revised criteria. Section 109(d)(2) requires that an
independent scientific review committee ``shall complete a review of
the criteria . . . and the national primary and secondary ambient air
quality standards . . . and shall recommend to the Administrator any
new . . . standards and revisions of the existing criteria and
standards as may be appropriate. . . .'' Since the early

1980s, this independent review function has been performed by the Clean
Air Scientific Advisory Committee (CASAC).
    Presently, the EPA is reviewing the criteria and the primary and
secondary NAAQS for PM.\1\ The draft IRP being announced today has been
developed as part of the planning phase for the review. This phase
began with a science policy workshop to identify issues and questions
to frame the review.\2\ Drawing from the workshop discussions, the
draft IRP was prepared jointly by the EPA's National Center for
Environmental Assessment, within the Office of Research and
Development, and the EPA's Office of Air Quality Planning and
Standards, within the Office of Air and Radiation. The draft IRP
presents the current plan and specifies the anticipated schedule for
the entire review, the process for conducting the review, and the key
policy-relevant science issues that will guide the review. The draft
IRP will be reviewed by CASAC at a teleconference on May 23, 2016.\3\
The final IRP will include consideration of CASAC advice and public
comments received on the draft IRP.
---------------------------------------------------------------------------

    \1\ The EPA's call for information for this review was issued on
December 3, 2014 (79 FR 71764).
    \2\ The EPA held a workshop titled ``Workshop to Discuss Policy-
Relevant Science to Inform EPA's Review of the Primary and Secondary
NAAQS for PM'' on February 9-11, 2015 (79 FR 71764).
    \3\ 81 FR 13362, March 14, 2016.

    Dated: April 14, 2016.
Stephen Page,
Director, Office of Air Quality Planning and Standards.
[FR Doc. 2016-09036 Filed 4-18-16; 8:45 am]
 BILLING CODE 6560-50-P