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[Federal Register Volume 78, Number 229 (Wednesday, November 27, 2013)]
[Notices]
[Pages 70935-70938]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-28508]

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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-OAR-2013-0743; FRL-9903-46-OAR]

Notice of Availability of the Environmental Protection Agency's 
2011 Emissions Modeling Platform

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of data availability (NODA).

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SUMMARY: The Environmental Protection Agency (EPA) is providing notice 
that the 2011 Emissions Modeling Platform data are available for public 
review and comment. The 2011 Emissions Modeling Platform consists of 
emissions inventory data, supporting data, and methods that are used to 
process the 2011 National Emissions Inventory (NEI) and related data 
into a form that can be used for air quality modeling. The platform, or 
portions of the data that make up the platform, may be used by the 
Office of Air and Radiation in several contexts, including the 
development of rules related to the transport of air pollution and the 
National Ambient Air Quality Standards. The platform may also be used 
for other studies such as the National Air Toxics Assessment. The EPA 
is requesting comment on the 2011 Emissions Modeling Platform, 
including the emissions inventories and on the supporting data and 
methods. A docket has been established to track the comments.

DATES: Comments must be received on or before March 31, 2014. Please 
refer to SUPPLEMENTARY INFORMATION for additional information on 
submitting comments and on the provided data.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2013-0743, by one of the following methods:
    www.regulations.gov. Follow the on-line instructions for 
submitting comments.
     Fax: (202)566-9744. Attention Docket ID No. EPA-HQ-OAR-
2013-0743.
     Mail: EPA Docket Center, WJC West (Air Docket), Attention 
Docket ID No. EPA-HQ-OAR-2013-0743, U.S. Environmental Protection 
Agency, Mailcode: 2822T, 1200 Pennsylvania Ave. NW., Washington, DC 
20460. Please include a total of 2 copies.
     Hand Delivery: U.S. Environmental Protection Agency, WJC 
West (Air Docket), 1301 Constitution Avenue NW., Room 3334, Washington, 
DC 20004, Attention Docket ID No. EPA-HQ- OAR-2013-0743. Such 
deliveries are only accepted during the Docket's normal hours of 
operation, and special arrangements should be made for deliveries of 
boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2013-0743. The EPA's policy is that all comments received will be 
included in the public docket without change and may be made available 
online at www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through www.regulations.gov 
or email. The www.regulations.gov Web site is an ``anonymous access'' 
system, which means the EPA will not know your identity or contact 
information unless you provide it in the body of your comment. If you 
send an email comment directly to the EPA without going through 
www.regulations.gov, your email address will be automatically captured 
and included as part of the comment that is placed in the public docket 
and made available on the Internet. If you submit an electronic 
comment, the EPA recommends that you include your name and other 
contact information in the body of your comment and with any disk or 
CD-ROM you submit. If the EPA cannot read your comment due to technical 
difficulties and cannot contact you for clarification, the EPA may not 
be able to consider your comment. Electronic files should avoid the use 
of special characters, any form of encryption, and be free of any 
defects or viruses. For additional information about the EPA's public 
docket, visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the 
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in

[[Page 70936]]

www.regulations.gov or in hard copy at the Air and Radiation Docket and 
Information Center, EPA/DC, WJC West Building Room 3334, 1301 
Constitution Ave. NW., Washington, DC. The Public Reading Room is open 
from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal 
holidays. The telephone number for the Public Reading Room is (202) 
566-1744, and the telephone number for the Air Docket is (202) 566-
1742.

FOR FURTHER INFORMATION CONTACT: For questions on the 2011 platform and 
on how to submit comments, contact Alison Eyth, Air Quality Assessment 
Division, Environmental Protection Agency, C339-02, 109 T.W. Alexander 
Drive, Research Triangle Park, NC 27709; telephone number: (919)541-
2478; fax number: (919) 541-0684; email address: eyth.alison@epa.gov.

SUPPLEMENTARY INFORMATION: The EPA is requesting comment on the 2011 
platform emission inventories; supporting ancillary files used to 
allocate emissions temporally, spatially, and by species; and on the 
emissions modeling methods used to process the inventories into data 
suitable for input to air quality models. Summaries of the emission 
inventories and data are provided to aid in the review of the data, but 
comments are sought on the actual data.

I. Additional Information on Submitting Comments

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

    1. Submitting CBI. Do not submit this information to the EPA 
through EDOCKET, 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 the EPA docket office specified in 
the Instructions, 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:
    i. Identify the notification by docket number and other identifying 
information (subject heading, Federal Register date and page number).
    ii. Explain your comments, why you agree or disagree; suggest 
alternatives and substitute data that reflects your requested changes.
    iii. Describe any assumptions and provide any technical information 
and/or data that you used.
    iv. Provide specific examples to illustrate your concerns, and 
suggest alternatives.
    v. Explain your views as clearly as possible, avoiding the use of 
profanity or personal threats.
    vi. Make sure to submit your comments by the comment period 
deadline identified.

B. Instructions for Agencies That Submit Data to the NEI

    1. Updates to the 2011 NEI. State, local, and tribal agencies that 
submit data to the NEI via the Emissions Inventory System (EIS) are 
encouraged to submit any updates to the 2011 emission inventory data 
through EIS as described in http://www.epa.gov/ttn/chief/net/2011inventory.html#v2instructions. Updates to emission inventories, and 
to model inputs used to develop mobile source emission inventories in 
the NEI, should be submitted through EIS even in cases in which the 
2011 modeling platform inventory data does not exactly match the NEI 
data. Specific examples of non-matching data are given in Section II. 
The EPA requests that agencies submitting updates via EIS also submit 
to the docket a comment that describes the nature of, and rationale 
for, the changes that were made in EIS to aid in the documentation of 
changes to the inventories. These agencies do not need to submit to the 
docket the actual updated emission inventory data or model inputs 
already provided to EIS.
    2. Updates to Other Data. EIS can accept updates to some of the 
categories of data for which EPA is requesting comments, but not for 
all of the data that exists in the modeling platform. The types of data 
that can be updated through EIS are noted below. Updates to all other 
modeling platform data and comments on the methods used must be 
provided through the docket. Additional details follow in Section I.C.

C. Instructions for Comments Not Submitted Through EIS

    The EPA can most effectively incorporate comments that provide 
specific alternative values to those in the EPA data sets, and for 
which accompanying documentation supports the alternative values. 
Commenters should provide the alternative data at a level of detail 
appropriate to the data set into which it will be incorporated, thereby 
including all key fields needed to substitute the old data with the 
new. For example, commenters should not provide a new set of county 
total emissions as an alternative to more detailed point source 
emissions data.
    Any alternative emission inventory or other data provided should be 
compatible with the formats used by the Sparse Matrix Operator Kernel 
Emissions (SMOKE) modeling system version 3.5, which is used by the EPA 
to process emission inventories into a format that can be used for air 
quality modeling. Formats are defined in the SMOKE Version 3.5 User's 
Manual available from http://www.smoke-model.org. Only the rows of data 
that have changed from those provided by the EPA should be included in 
the alternative data sets.

II. Information Available for Public Comment

    The 2011 Emissions Modeling Platform consists of emission 
inventories primarily based on the 2011 NEI version 1, additional 
ancillary data files that are used to convert the NEI emissions into a 
form that can be used for air quality modeling, along with the methods 
used to prepare the air quality model inputs. The NEI represents 
emissions of criteria and hazardous pollutants into the atmosphere from 
all source categories within the United States. 2011 is the latest year 
for which a complete NEI for all emission processes is available. These 
complete, national emission inventories are prepared every three years 
and are primarily based on data and inputs provided by state, local, 
and tribal agencies for sources within their jurisdictions. The NEI 
includes emissions from sources at specific locations called point 
sources, emissions from fire events, and county-level emissions of 
onroad mobile sources, nonroad mobile sources, and other nonpoint 
sources.
    The 2011 emissions modeling platform is named for the year of the 
data that it represents. The emission inventories in the modeling 
platform are primarily based on the 2011 NEI version 1, although there 
are some key differences between the platform inventories and the NEI. 
First, in the modeling platform, the NEI inventories are split into 
additional categories called modeling sectors. For example, the point 
sources are split into peaking electric generating units (EGUs), other 
EGUs, oil and gas sources, and other point sources. The nonpoint 
sources are split into agricultural ammonia sources, residential wood 
sources, oil and gas

[[Page 70937]]

sources, and other nonpoint sources. Other differences between the 
platform inventories and the NEI are in the emission values for 
commercial marine vessel emissions in specific areas, in the mobile 
source emissions in California and Texas, and the inclusion of 
additional ethanol plants in the modeling platform. Another difference 
is in the onroad mobile source emissions inventory values due to the 
use of different versions of the Motor Vehicle Emissions Simulator 
(MOVES) in the two data sets.
    The 2011 emissions modeling platform also includes emissions 
inventories for Canada and Mexico, along with ancillary data files used 
to allocate annual emissions to the hourly, gridded emissions of 
chemical species used by an air quality model (AQM). The types of 
ancillary data files include temporal profiles that allocate annual and 
monthly emissions down to days and hours, spatial surrogates that 
allocate county-level emissions onto the grid cells used by an AQM, and 
speciation profiles that allocate the pollutants in the NEI to the 
chemical species used by an AQM. In addition, there are temporal, 
spatial, and speciation cross-reference files that map the emission 
sources in the emission inventories to the appropriate profiles based 
on their location, emissions source classification code (SCC), and in 
some cases the specific facility or unit.
    The 2011 emissions modeling platform, or portions of the data that 
make up the platform, may be used by the Office of Air and Radiation in 
several contexts including the development of rules related to the 
transport of air pollution and the National Ambient Air Quality 
Standards. Air quality modeling results that are based on the outputs 
of the emissions modeling platform are typically used in support of 
Regulatory Impact Analyses (RIAs) and sometimes support other aspects 
of rulemaking. The platform may also be used for other studies such as 
the National Air Toxics Assessment.
    The EPA has placed key information related to the 2011 emissions 
modeling platform into the electronic docket available at 
www.regulations.gov. However, many of the detailed data files are too 
large to be directly uploaded into the electronic docket and/or are not 
in formats accepted by that docket. Therefore, the information placed 
in the electronic docket, associated detailed data, and summaries to 
help with interpretation of the data are available for public review on 
the CHIEF Emissions Modeling Clearinghouse on EPA's Web site at http://www.epa.gov/ttn/chief/emch/index.html#2011. Supplementary custom and 
prepared summaries and extractions of the 2011 NEI, and documentation 
thereof, are also available on EPA's Web site at http://www.epa.gov/ttn/chief/net/2011inventory.html.
    The emissions inventories, along with many of the ancillary files, 
are provided in the form of flat files that can be input to SMOKE. Flat 
files are comma-separated value style text files with columns and rows 
that can be loaded into spreadsheet or database software. The columns 
of interest in the emission inventory files are specified in each 
subsection below. The EPA requests comment on the following components 
of the 2011 emissions modeling platform data:
     Emission values. The emissions inventories used for the 
modeling platform are largely consistent with the 2011 NEI version 1 
but are split into smaller sectors for emissions modeling. The EPA 
requests comment on both the criteria air pollutant (CAP) and hazardous 
air pollutant (HAP) emissions in the modeling inventories. The annual 
emissions values are located in the ANN--VALUE column of the emission 
inventory files in Flat File 2010 (FF10) format. Some emission 
inventories (e.g., nonroad) may also have values filled in to the 
monthly value columns (e.g., JAN--VALUE, FEB--VALUE, [hellip], DEC--
VALUE). The EPA requests comment on both the annual and monthly 
emissions values, where applicable. Summaries of emissions by state and 
county are provided to aid in the review of emissions values. Because 
the onroad emissions data differs from that in the NEI, and because of 
the data volume, state-specific extractions of the onroad emissions 
inventory data are provided. For EIS data submitters, updates to 
emission values can be provided via EIS.
     Model inputs and activity data used to develop mobile 
source emission inventories. The emission inventories in the NEI for 
onroad and nonroad mobile sources are developed by running MOVES and 
the National Mobile Inventory Model (NMIM), respectively. The EPA 
requests comment on the model input data used to develop the mobile 
source emission inventories. These include both the direct inputs to 
MOVES used to create emission factors and the vehicle miles traveled 
and vehicle population activity data used to compute the emissions. 
Alternative activity data may be provided in MOVES county databases or 
in SMOKE FF10 activity data format. For EIS data submitters, updates to 
mobile source input databases can be provided via EIS.
     CEMS data differing from NEI values. In most cases, the 
Continuous Emissions Monitoring System (CEMS) data for 2011 are very 
close to the values in the 2011 NEI version 1 for specific units. 
However, there are some cases for which the values are different, such 
as when a CEMS only reports for part of the year. The EPA requests 
comment on the specific instances in which the NEI data and CEMS data 
are not consistent. A report specifying the sources that differ is 
provided.
     Stack parameters. The release of emissions from stack-
based point sources are characterized with stack height, diameter, 
temperature, and either flow or velocity. In the 2011 NEI version 1, 
some sources are not adequately characterized with all of the needed 
parameters. In some cases, the specified parameters do not seem 
realistic given the volume of emissions exiting the stack. The EPA 
requests comment on the stack parameters found in the STKHGT, STKDIAM, 
STKTEMP, STKFLOW, and STKVEL columns of point source emission inventory 
flat files. To facilitate review of this information, a stack parameter 
summary is provided for EGU point sources and for non-EGU point sources 
other than airports, fires, and commercial marine vessels. For EIS data 
submitters, updates to stack parameters can be provided via EIS.
     Stack locations. The location of point sources is 
specified by the values in the LATITUDE, LONGITUDE, and LL--DATUM 
columns in point source emission inventory flat files. The EPA seeks 
comment on these stack locations, which can be especially important in 
the context of risk modeling. Stack locations are included in the stack 
parameter summary. For EIS data submitters, updates to stack locations 
can be provided via EIS.
     Existing control techniques. The 2011 NEI version 1 
includes information on emissions control techniques listed in terms of 
control codes submitted to the EIS. These are listed in the CONTROL--
IDS and CONTROL--MEASURES columns in the emission inventory data sets, 
with levels of reduction in the ANN--PCT--RED column. Projection of 
point source emissions to future years is dependent on this 
information. The EPA seeks comment on whether information on existing 
controls given in the inventory flat files is incomplete or erroneous. 
Control techniques independent of pollutant are included in the stack 
parameter summary. The flat files must be consulted for details of 
control techniques by pollutant. For EIS data

[[Page 70938]]

submitters, updates to control techniques can be provided via EIS.
     Boiler design capacity. The EPA seeks comment on the 
design capacity of boilers as characterized in the DESIGN--CAPACITY and 
DESIGN--CAPACITY--UNITS columns of point source emission inventory flat 
files. Design capacity is included in the stack parameter summary. For 
EIS data submitters, updates to design capacities can be provided via 
EIS.
     Emissions modeling methods. The EPA is using the SMOKE 
version 3.5 to prepare data for air quality modeling. The EPA requests 
comment on the methods by which SMOKE is used to develop air quality 
model-ready emissions, as illustrated in the scripts provided with the 
modeling platform.
     Temporal allocation. Annual emission inventories must be 
allocated to hourly values prior to air quality modeling. This may be 
done with temporal profiles in several steps, such as annual-to-month, 
month-to-day, and day-to-hour. The exact method used depends on the 
type of emissions being processed. The EPA seeks comment on the 
allocation of the emission inventories to month, day, and hour for all 
types of emission processes. In particular, the EPA seeks information 
that could help improve the temporal allocation of emissions from EGUs, 
onroad and nonroad mobile sources, and residential wood combustion 
sources. The EPA seeks to continue to improve temporal allocation 
factors with additional local and region-specific data. In addition to 
providing temporal allocation data as SMOKE input files, spreadsheets 
containing temporal allocation factors and cross references are 
provided for readability.
     Spatial surrogates. Spatial surrogates are used to 
allocate county-level emissions into grid cells used for air quality 
modeling. The EPA requests comment on the spatial surrogates used in 
the 2011 emissions modeling platform. Plots of spatial surrogates and a 
spreadsheet containing the spatial cross reference data are provided 
for readability.
     Chemical speciation. Prior to air quality modeling, the 
pollutants in the emission inventories must be converted into the 
chemical species used by the air quality model using speciation 
profiles. The speciation profiles in the 2011 emissions modeling 
platform are consistent with version 4.5 of the SPECIATE database. The 
EPA requests comment on the speciation profiles used in the 2011 
modeling platform, as well as any information that could help improve 
the speciation of oil and gas emissions in both the eastern and western 
United States. In addition to providing chemical speciation data as 
SMOKE input files, spreadsheets containing chemical speciation factors 
and cross references are provided for readability.
    To aid in the interpretation of the provided data files and how 
they relate to the aspects of the data on which the EPA is requesting 
comment, the EPA has provided in the docket a document describing the 
information included in the provided data files.

    Dated: November 20, 2013.
Mary Henigin,
Acting Director, Office of Air Quality Planning and Standards.
[FR Doc. 2013-28508 Filed 11-26-13; 8:45 am]
BILLING CODE 6560-50-P
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