[Federal Register Volume 80, Number 239 (Monday, December 14, 2015)]
[Notices]
[Pages 77337-77340]
[FR Doc No: 2015-31307]

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ENVIRONMENTAL PROTECTION AGENCY

[EPA-R09-OAR-2015-0779; FRL-9940-06-Region 9]

Official Release of EMFAC2014 Motor Vehicle Emission Factor Model
for Use in the State of California

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability.

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SUMMARY: The Environmental Protection Agency (EPA) is approving and
announcing the availability of the latest version of the California
EMFAC (short for EMission FACtor) model for use in state implementation
plan (SIP) development and transportation conformity in California.
EMFAC2014 is the latest update to the EMFAC model for use by California
state and local governments to meet Clean Air Act (CAA) requirements.
The new model, which is based on new and improved data, calculates air
pollution emissions factors for passenger cars, trucks, motorcycles,
motor homes and buses. Today's notice also sets the date after which
EMFAC2014, rather than EMFAC2011, must be used to satisfy the
requirement that conformity determinations be based on the latest
emissions model available. This requirement can be met by using the
most current version of the motor vehicle emissions model approved by
the EPA. Since the EMFAC model is used only in California, the EPA's
approval and the announcement of the availability of the model does not
affect the applicability of the Motor Vehicle Emissions Simulator
(MOVES) model for users in other states.

DATES: The EPA's approval of the EMFAC2014 emissions model for SIP and
conformity purposes is effective December 14, 2015. EMFAC2014 must be
used as described in this Notice for all new regional emissions
analyses and carbon monoxide (CO) and particulate matter
(PM10 and PM2.5) hot-spot analyses for
transportation conformity purposes that are started on or after
December 14, 2017.

FOR FURTHER INFORMATION CONTACT: Karina O'Connor,
<EMAIL_ADDRESS>(775) 434-8176, Air Planning Office (AIR-2),
Air Division, U.S. EPA, Region 9, 75 Hawthorne Street, San Francisco,
California 94105-3901.

SUPPLEMENTARY INFORMATION: Copies of the official version of the
EMFAC2014 model, including technical support documents, are available
on the California Air Resources Board (CARB) Web site: http://www.arb.ca.gov/msei/categories.htm#onroad_motor_vehicles. Throughout
this document, ``we,'' ``us'' and ``our'' refer to EPA.

I. Background

A. What is the EMFAC model?

    The EMFAC model is a computer model that can estimate emission
rates for on-road mobile sources (``motor vehicles'') for calendar
years from 2000 to 2050 operating in California. Pollutant emissions
for hydrocarbons (HC), CO, nitrogen oxides (NOX),
PM10, PM2.5, lead, carbon dioxide
(CO2), and sulfur oxides are output from the model.
Emissions are calculated for fifty-one different vehicle classes
composed of passenger cars, various types of trucks and buses,
motorcycles, and motor homes.
    EMFAC is used to calculate current and future inventories of motor
vehicle emissions at the state, air district, air basin, county, or
project level. EMFAC contains default vehicle activity data, and the
option of modifying that data, so it can be used to estimate a motor
vehicle emissions inventory in tons/day for a specific year, month, or
season, and as a function of ambient temperature, relative humidity,
vehicle population, mileage accrual, miles of travel and speeds. Thus
the model can be used to make decisions about air pollution policies
and programs at the local or state level.
    Inventories based on EMFAC are also used to meet the federal CAA's
SIP and transportation conformity requirements. Transportation
conformity is required under CAA section 176(c) to ensure that
federally supported transportation plans, transportation improvement
programs (TIPs), and highway and transit projects are consistent with
(``conform to'') the purpose of the SIP. Conformity to a SIP means that
a transportation activity will not cause or contribute to new air
quality violations, worsen existing violations, or delay timely
attainment of the national ambient air quality standards (NAAQS) or
interim milestones. The EPA's transportation conformity regulations (40
CFR parts 51.390 and 93) describe how federally funded and approved
highway and transit projects meet these statutory requirements. EMFAC
is used statewide in all regional emissions analyses and CO,
PM10 and PM2.5 hot-spot analyses for
transportation conformity determinations in California.

B. What versions of EMFAC are currently in use in California?

    Most SIPs in California were developed using EMFAC2011 (released by
CARB in September 2011) or EMFAC2007 (released by CARB in October
2007). The EPA approved and announced the availability of EMFAC2011 on
March 16, 2013 (78 FR 14533) and approved and announced the
availability of EMFAC2007 on January 18, 2008 (73 FR 3464) for all
nonattainment and maintenance areas in California.
    EMFAC2011 was considered a major update to previous versions of
EMFAC and most SIPs in California were updated with EMFAC2011 in the
2012-2014 timeframe. EMFAC2011 included a new model structure, new data
and methodologies regarding calculation of motor vehicle emissions, and
revisions to implementation data for control measures.

C. Why is the EPA announcing its approval of the EMFAC model?

    CAA section 172(c)(3) and 40 CFR 51.114(a) require that SIP
inventories be based on the most current, accurate, and applicable
models that are available at the time the SIP is developed. CAA section
176(c)(1) and 40 CFR 93.111(a) require that the latest emissions
estimates be used in conformity analyses. The EPA approves models that
fulfill these requirements.
    Under 40 CFR 93.111(a), the EPA must approve new versions of EMFAC
for SIP purposes before they can be used in transportation conformity
analyses. In a May 21, 2015 letter, CARB requested that the EPA approve
EMFAC2014 for use in developing SIPs and in determining conformity in
California.\1\ EMFAC2014 is a significant change from previous EMFAC
models with a new model user interface and is capable of calculating
motor vehicle emissions for all California areas. EMFAC2014 is being
approved as the latest emissions model for statewide use in SIP
development and emissions analyses for conformity purposes. Since the
EMFAC model is only used in California, the EPA's statewide approval of
the model does not affect the applicability of the MOVES emissions
factor model for users in other states.
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    \1\ The EMFAC2014 model and supporting information is available
for downloading at http://www.arb.ca.gov/msei/categories.htm#onroad_motor_vehicles. Technical documentation
explaining the changes to the model and the technical foundations
for the model is available at http://www.arb.ca.gov/msei/downloads/emfac2014/emfac2014-vol3-technical-documentation-052015.pdf .
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II. EPA Action

A. What version of EMFAC is the EPA approving?

    In this notice, the EPA is approving and announcing that EMFAC2014
is available to use in statewide California SIP development and for
regional emissions analyses and CO, PM10 and
PM2.5 hot-spot analyses for transportation conformity.
EMFAC2014 was developed by CARB and transmitted for approval to the EPA
on May 21, 2015.
    The EMFAC2014 model has been rewritten using Python and MySQL
software into a new structure that will facilitate future model
updates, and allow CARB to incorporate updated regulations and
emissions data into the model and provide for a more simplified user
experience. The four major modules of EMFAC2011: EMFAC-LDV, EMFAC-HD,
EMFAC-SG and EMFAC-PL have been integrated into EMFAC2014, under one
interface. The model is now operated in either the Emissions Mode or
the Emissions Rate Mode for regional emissions analyses to access
emission databases and vehicle activity data for the appropriate
geographic subarea. EMFAC2014 Project-Level Assessment (EMFAC2014-PL)
is triggered when EMFAC2014 is run under the Emissions Rate Mode. Using
EMFAC2014-PL, emissions rates are estimated based on user-specified,
project-specific conditions. A handbook for using EMFAC2014 at the
project level is available from CARB at: http://www.arb.ca.gov/msei/downloads/emfac2014/emfac2014-vol2-pl-handbook-052015.pdf. EMFAC2014
allows users to run one model for SIP inventories, regional emissions
analyses and project analyses.

B. What analyses can EMFAC2014 be used for?

    The EPA is approving the model to estimate regional emissions of
HC, CO, NOX, PM10, PM2.5, lead, and
sulfur oxides.\2\ However, EMFAC2014 will only be used in
transportation conformity for pollutants and precursors that are
transportation-related emissions, e.g., HC, CO, NOX,
PM10 and PM2.5.
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    \2\ The EPA notes that EMFAC2014 can be used for CO2
emissions analyses as well, but there are no SIP or transportation
conformity requirements for greenhouse gases (GHGs). In addition,
although SO2 is listed as a potential precursor for
PM2.5 formation in 40 CFR 93.102(b)(2)(v), this precursor
has not been considered significant for the on-road mobile sources
covered by transportation conformity in California to date.
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    The EPA is also approving EMFAC2014 to estimate CO, PM10
and PM2.5 emissions for conformity hot-spot analyses
involving individual transportation projects. A hot-spot analysis is
defined in 40 CFR 93.101 as an estimation of likely future localized
pollutant concentrations and a comparison of those concentrations to
the relevant NAAQS. This analysis is conducted on a smaller scale than
a nonattainment or maintenance area, e.g., for a congested roadway
intersection.
    The EPA also notes that this approval action does not impact what
methodology is required for calculating re-entrained road dust for
regional PM10 and PM2.5 SIPs and transportation
conformity analyses. EMFAC2014's PM10 and PM2.5
estimates do not include such emissions. When applicable,
PM10 and PM2.5 nonattainment and maintenance
areas are required to use the EPA's AP-42 road dust method for
calculating road dust emissions, unless a local method is approved in
advance by the EPA.\3\ In addition, EMFAC2014 does not estimate ammonia
emissions. Air quality and transportation agencies should contact the
EPA Regional Office if ammonia emissions estimates are needed for SIPs
or regional conformity emissions analyses.
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    \3\ For further information, see the EPA's February 4, 2011
Notice of Availability for the January 2011 AP-42 Method for
Estimating Re-entrained Road Dust from Paved Roads (76 FR 6328).
Also, for using AP-42 for unpaved roads, see the EPA's August 2,
2007 memorandum, ``Policy Guidance on the Use of the November 1,
2006, Update to AP-42 for Re-entrained Road Dust for SIP Development
and Transportation Conformity.''
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C. Why does the EPA consider EMFAC2014 to be a major update to EMFAC?

    EMFAC2014 includes significant changes to its model interface, new
data and methodologies regarding calculation of motor vehicle emissions
and revisions to implementation data for control measures. EMFAC2014
includes updated data on car and truck activities, and emissions
reductions associated with CARB's Advanced Clean Cars regulations,\4\
supporting new estimates of emissions from heavy-heavy duty diesel
trucks and buses. Motor vehicle fleet age, vehicle types and vehicle
population have also been updated based on 2000-2012 California
Department of Motor Vehicle (DMV) data. Each of these changes impact
emission factors for each area in California. The new model interface
for EMFAC2014 will allow users to update the default VMT data and speed
profiles by vehicle class for different future scenarios. CARB's Web
site describes these and other model changes at: http://www.arb.ca.gov/msei/categories.htm#onroad_motor_vehicles.
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    \4\ For further information, see EPA's January 9, 2013 waiver of
preemption for the Advanced Clean Cars regulations at http://www.gpo.gov/fdsys/pkg/FR-2013-01-09/pdf/2013-00181.pdf.
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D. How were stakeholders and the public involved in the EMFAC
development process?

    Since 2013, CARB has held a series of public workshops to discuss
emissions inventory updates and EMFAC updates and to receive comments
on the resulting changes in the emissions inventory and models.\5\ CARB
also conducted beta testing of interim versions of the model with air
districts and Metropolitan Planning Organizations (MPOs). Stakeholders
and other members of the public had the opportunity to request
briefings with CARB staff and provide them with comments and
suggestions to improve the model. The EPA was included in those
discussions and our suggestions were incorporated into the material

available on the CARB EMFAC public Web site. CARB also developed and
posted training modules for EMFAC2014 and supports a mobile source
emissions inventory email listserv to announce updates and changes to
the EMFAC supporting material.\6\
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    \5\ See http://www.arb.ca.gov/msei/workshop-meetings.htm.
    \6\ To subscribe to CARB's listserv for Mobile Source Emission
Inventory development, see ``Join our MSEI listserv'' at
www.arb.ca.gov/msei/msei.htm.
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    CARB also made available to the public a series of technical memos
that describe each update to the model and public presentations that
summarize the changes from earlier versions of the model. The technical
memos are available on CARB's Web site at: http://www.arb.ca.gov/msei/downloads/emfac2014/emfac2014-vol4-comp-table-of-emfac-topics-052015.xlsx and at http://www.arb.ca.gov/msei/categories.htm#onroad_motor_vehicles. Specific changes incorporated
into the EMFAC2014 model are also discussed in http://www.arb.ca.gov/msei/downloads/emfac2014/emfac2014-vol3-technical-documentation-052015.pdf. All presentations from the public workshops are available
on the CARB Web site at: http://www.arb.ca.gov/msei/workshop-meetings.htm.

E. Does this Notice establish a transportation conformity grace period
for the use of this model?

    Yes. The transportation conformity rule (40 CFR 93.111) requires
that conformity determinations be based on the latest motor vehicle
emissions model approved by the EPA for SIP purposes for a state or
area. Section 176(c)(1) of the CAA states that

. . . [t]he determination of conformity shall be based on the most
recent estimates of emissions, and such estimates shall be
determined from the most recent population, employment, travel, and
congestion estimates. . . .

    When the EPA approves and announces the availability of a new
emissions model such as EMFAC2014, the EPA will consult with the U.S.
Department of Transportation (DOT) to establish a grace period before
the model is required for conformity analyses (40 CFR 93.111(b)). The
conformity rule provides for a grace period for new emissions models of
between 3 and 24 months after notice of availability is published in
the Federal Register (40 CFR 93.111(b)(1)).
    The EPA articulated its intentions for establishing the length of a
conformity grace period in the preamble to the 1993 transportation
conformity rule (November 24, 1993, 58 FR 62211):

    EPA and DOT [the Department of Transportation] will consider
extending the grace period if the effects of the new emissions model
are so significant that previous SIP demonstrations of what emission
levels are consistent with attainment would be substantially
affected. In such cases, States should have an opportunity to revise
their SIPs before MPOs must use the model's new emissions factors.

    In consultation with the Federal Highway Administration (FHWA) and
the Federal Transit Administration (FTA), the EPA considers ``the
degree of change in the model and the scope of re-planning likely to be
necessary by MPOs in order to assure conformity'' in establishing the
length of the grace period (40 CFR 93.111(b)(2)).
    Upon consideration of these factors, the EPA is establishing a two-
year grace period before EMFAC2014 is required for the following
conformity analyses:
     All new HC, NOX, PM10,
PM2.5 and CO regional emissions analyses (e.g., supporting
transportation plan and TIP conformity determinations); and
     All new CO, PM10 and PM2.5 hot-spot
analyses supporting project-level conformity determinations.
    The grace period begins on December 14, 2015 and ends on December
14, 2017. Areas have the option of using the new model prior to the end
of the grace period.
    As discussed earlier in the notice, EMFAC2014 incorporates
significant changes to the model interface and procedures used to
estimate both emissions for regional emissions analysis and hot-spot
analyses for CO and PM. In addition to incorporating the new EMFAC2014
procedures, state and local agencies also need to consider how the
model affects regional conformity analysis results and whether SIP and/
or transportation plan/TIP changes are necessary to assure future
conformity determinations. As stated earlier in the notice, the changes
to EMFAC impact emission factors for each area in California. CARB has
requested an 18-month grace period to allow them to update SIPs
previously developed using EMFAC2007 or EMFAC2011 with the updated
emissions from EMFAC2014 during 2016. Therefore, additional time is
necessary for CARB to revise previously approved SIPs with EMFAC2014
and complete the SIP revision process, so that MPOs can incorporate
revised SIP budgets into the transportation conformity process.
    For application of EMFAC2014 at the project level, while EMFAC2014
was originally released by CARB in October of 2014, project sponsors
developing future project-level analysis may need some time to
familiarize themselves with this model.
    Therefore, it is appropriate to set a two-year grace period to
allow all areas in California to incorporate EMFAC2014 in conformity
hot-spot analyses and apply the changes to the model structure and
updated planning assumptions incorporated in EMFAC2014 in a timely
manner. In the interim, new PM and CO hot-spot analyses that are
started prior to the end of the EMFAC2014 grace period can be based on
EMFAC2011 and the EPA's existing PM hot-spot guidance \7\ (40 CFR
93.111(c)).
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    \7\ See Web page http://www3.epa.gov/otaq/stateresources/transconf/projectlevel-hotspot.htm#pm-hotspot for latest guidance
documents and information.
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    When the grace period ends on December 14, 2017, EMFAC2014 will
become the only approved motor vehicle emissions model for all new
regional and hot-spot transportation conformity analyses across
California, as a means of meeting the requirement to use the latest
emissions information in conformity analyses (40 CFR 93.111). In
general, this means that all new HC, NOX, PM10,
PM2.5, and CO regional conformity analyses and CO,
PM10 and PM2.5 hot-spot analyses started after
the end of the two-year grace period must be based on EMFAC2014, even
if the SIP is based on an earlier version of the EMFAC model. The EPA
is considering what project-level guidance is necessary for EMFAC2014
and will make information available on the EPA's Web site: www.epa.gov/otaq/stateresources/transconf/projectlevel-hotspot.htm.
    In addition, in most cases, if an area revises previously approved
EMFAC2011-based SIP budgets using EMFAC2014, the revised EMFAC2014
budgets would be used for conformity purposes once the EPA approves the
SIP revision. In general, the EPA will not make adequacy findings for
these SIPs because submitted SIPs cannot supersede approved budgets
until they are approved. However, 40 CFR 93.118(e)(1) allows an
approved budget to be replaced by an adequate budget if the EPA's
approval of the initial budgets specifies that the budgets being
approved may be replaced in the future by new adequate budgets. This
flexibility has been used in limited situations in the past, such as
during the transition from EMFAC7F and EMFAC7G to EMFAC2002. See 67 FR
46618 (July 16, 2002); 67 FR 69139 (November 15, 2002); and 68 FR 15720
(April 1, 2003). In such cases, the EMFAC2014-based budgets would be
used for conformity purposes once they have been found adequate. States
should consult with the EPA as needed

to determine if this flexibility applies to their situation.

F. Can areas use EMFAC2011 during the grace period?

    Yes, the conformity rule provides some flexibility for regional
emissions analyses that are started before the end of the grace period.
Analyses that begin before or during the grace period may continue to
rely on EMFAC2011. The interagency consultation process should be used
if it is unclear if an EMFAC2011-based analysis was begun before the
end of the grace period. When the grace period ends, EMFAC2014 will
become the EPA-approved motor vehicle emissions model for regional
emissions analyses for transportation conformity in California.
    CO, PM10 and PM2.5 hot-spot analyses for
project-level conformity determinations can be based on EMFAC2011 if
the analysis was begun before the end of the grace period, and if the
final environmental document for the project is issued no more than
three years after the issuance of the draft environmental document (see
40 CFR 93.111(c)). Therefore quantitative analysis already underway
that were started before the end of the grace period using EMFAC2011
can be completed as long as 40 CFR 93.111(c) is satisfied. The
interagency consultation process should be used if it is unclear
whether an EMFAC2011-based analysis is covered by the circumstances
described in the conformity rule.

G. Future Updates to EMFAC

    On January 31, 2006, CARB submitted a letter to the EPA and to the
California Division of the FHWA indicating the State's intention to
make future revisions to update EMFAC. These EMFAC updates would
reflect, among other new information, updated vehicle fleet data every
three years. In California, MPOs and Air Districts have not been able
to update vehicle fleet data embedded into EMFAC. The EPA's July 2004
final rule (69 FR 40004) states that new vehicle registration data must
be used when it is available prior to the start of new conformity
analyses and that states and MPOs are strongly encouraged to update the
data at least every five years as described in EPA/USDOT December 2008
guidance.\8\ The next update to the planning assumptions in EMFAC is
expected in 2017.
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    \8\ For more information on qualitative PM hot-spot analyses,
see the EPA and the FHWA's joint ``Guidance for The Use of Latest
Planning Assumptions in Transportation Conformity Determinations''
(EPA420-B-08-901, December 2008).
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III. Summary of EPA Actions

    As described in this notice, the EPA is approving and announcing
the availability of EMFAC2014 as submitted by CARB on May 21, 2015 with
the following limitations and conditions:
    (1) The approval is limited to California.
    (2) The approval is Statewide and applies to estimation of
emissions of HC, CO, NOx, PM10, PM2.5,
lead, and sulfur oxides. In addition, EMFAC2014 will be used in
transportation conformity regional emissions analyses for pollutants
and precursors that are applicable in a given nonattainment or
maintenance area. The EPA is approving the emission factor elements of
EMFAC2014, but not the associated default travel activity (e.g. Vehicle
Miles Traveled). The EPA is also approving EMFAC2014's Emission Rate
Mode that allows the model to estimate project-level emissions for CO,
PM10 and PM2.5 conformity hot-spot analyses.
    (3) A 24-month statewide transportation conformity grace period
will be established beginning December 14, 2015 and ending December 14,
2017 for the transportation conformity uses described in (2) above.

    Dated: December 2, 2015.
Jared Blumenfeld,
Regional Administrator, Region IX.
[FR Doc. 2015-31307 Filed 12-11-15; 8:45 am]
 BILLING CODE 6560-50-P