June 30, 2017
2017 NEI Draft Plan
1 Introduction
The National Emissions Inventory (NEI) is a comprehensive and detailed estimate of annual total air
emissions of both criteria and hazardous air pollutants (HAPs) from all air emissions sources. The NEI is
prepared at least every three years by the U.S. EPA based primarily upon emissions estimates and
emissions model inputs provided by State, Local and Tribal (SLT) air agencies, and supplemented by data
developed by the EPA. The NEI is created to provide EPA, federal and state decision makers, the U.S.
public, and other countries the U.S.'s best and most complete estimates of criteria air pollutants and
precursors (CAPs) and HAP emissions. The NEI is used by the EPA in support of evaluating National
Ambient Air Quality Standards (NAAQS), assessing interstate transport of air pollutants, air toxics
programs, and for international reporting. It is also used by state and local air agencies as a starting point
for State Implementation Plan (SIP) development, other federal agencies, researchers, and environmental
groups to understand sources of air pollution.
The NEI is created based on both regulatory and technical components. The Air Emissions Reporting
Rule (AERR) (40 CFR Part 51) is the rule that requires states to submit emissions of CAP emissions and
provides the framework for voluntary submission of HAP emissions. The AERR, revised in 2015, requires
agencies to report all sources of emissions, except fires and biogenic sources. The AERR also lowers the
reporting threshold for lead emissions as point sources to 0.5 tons per year of actual emissions and,
except for California, requires agencies to report the inputs needed to model emissions from onroad
mobile and nonroad equipment mobile sources. Sources are divided into large groups called "data
categories": stationary sources are reported in "point" or "nonpoint" (county totals) and mobile sources
in onroad (cars and trucks), nonroad (off-road vehicles and nonroad equipment such as lawn and garden
equipment), point (airports and railyards), or nonpoint (marine and locomotives). Large fires (wild and
prescribed) are reported in a data category called 'EVENTS." The AERR specifies emissions thresholds
above which states must report stationary emissions as "point" sources with the remainder of the
stationary emissions reported as "nonpoint" sources.
Since the 2008 NEI, the Emissions Inventory System (EIS) has been the data system for collecting and
storing current and historical emissions inventory data. The AERR requires the submission of data
electronically to the EIS through the Central Data Exchange (CDX), and the EIS is used to receive and store
emissions data and to select the data to be included in the NEI. The EIS not only holds the emissions data,
it also provides all reporting codes, and EIS quality assurance (QA) checks, and there are Bridge Tools to
available to allow agencies to report NEI datasets to the EIS. The EIS also includes agency organization
profiles such as a list of agency staff and contact information who are responsible for submitting or
reviewing data. Lastly, the EIS provides feedback reports to agencies with results of EIS QA checks on
reported data as well as reports on facilities and emissions useful for summarizing and reviewing agency
data and the NEI.
Since the inception of the EIS, the EPA has worked to ensure that all changes to business processes, codes,
QA checks, etc., are provided to the SLT air agencies by June 1st of the year that the submission window
opens. For the 2017 inventory, this date is June 1, 2018. However, air agency feedback indicated that
this timeline did not give SLTs enough time to implement associated changes into SLT data systems. In
response to those comments, the EPA is posting changes by July 1st, 2017, approximately one year before
the submission window opens (18 months before the data are due).
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The NEI team staff are sensitive to the impact that these changes have on SLTs and are interested in
comments from the SLT air agency staff. The NEI team will assist SLT staff wherever possible to implement
any needed changes into your system. While we try to minimize changes to the EIS, these improvements
are intended to help the EPA to create a more complete, accurate, and timely inventory, which is
ultimately also in the best interest of SLT agencies as well.
2 Schedule
The detailed draft schedule for the 2017 NEI is provided below. A key change to this schedule from what
was done for the 2014 NEI is that most of the nonpoint inventory will be created using a staggered
schedule. As was done for the 2014 NEI, comments on the draft 2017 NEI will not be permitted to include
SLT agencies submitting wholesale replacement data. In the past, allowing wholesale replacements had
the unintended effect of delaying the NEI release by many weeks or months and increasing EPA costs to
unsustainable levels. SLT agencies will still be able to send data corrections during a QA period. We are
including a placeholder for a second version ("v2") of the 2017 NEI. but the timing of this is unknown,
likely to again be dependent on modeling, risk assessment or other policy needs. We are also including
a schedule for the overlapping 2018 NEI submissions, so that the EPA and SLT agencies can plan
accordingly.
Resources Submission/Comment Window 2018 NEI
2017 National Emission Inventory Timeline
Activity
Timeframe
Facility/
Point
Nonpoint
Onroad/
Nonroad
Events
EPA posts draft vl tools for Category 1
3/31/2017
X
SLT comments on Cat 1 draft tools due
5/31/2017
X
Post list of nonpoint sectors where EPA will develop estimates
5/31/2017
X
SLT comments on 2017 Draft NEI Plan Due
9/1/2017
Finalize changes to codes, QA routines, business processes for 2017
10/1/2017
X
X
X
X
Provide SLT List of Priority Pollutants/Facilities on 2017 Website
10/31/2017
X
Post expected pollutant lists on 2017 Website
10/31/2017
X
X
X
SLTs submit inputs for Category 1 tools
8/1/2017 -
11/30/2017
X
EPA posts vl tools for Category 1 tools
11/30/2017
X
EPA posts final nonpoint emissions for Category 1 tools
1/31/2018
X
Post updated Nonpoint Survey. Post point-nonpoint reconciliation table.
1/15/2018
X
Post instructions and 2017 default inputs for onroad and nonroad
6/1/2018
X
Submission Window Opens
6/15/2018
X
X
X
X
Post instructions for submitting fire activity data
6/30/2018
X
EPA posts draft vl tools for Category 2
10/31/2017
X
SLT comments on Cat 2 draft tools due
1/31/2018
X
SLTs submit inputs for Category 2 tools
1/1/2018 -
6/30/2018
X
EPA posts vl tools for Category 2 tools
6/30/2018
X
EPA posts final nonpoint emissions for Category 2 tools
9/30/2018
X
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Resources Submission/Comment Window 2018 NEI
2017 National Emission Inventory Timeline
Activity
Timeframe
Facility/
Point
Nonpoint
Onroad/
Nonroad
Events
EPA posts draft vl tools for Category 3
8/31/2018
X
SLT comments on Cat 3 draft tools due
11/30/2018
X
SLTs submit inputs for Category 3 tools
12/1/2018-
5/31/2019
X
EPA posts vl tools for Category 3 tools
2/28/2019
X
EPA posts final nonpoint emissions for Category 3 tools
8/31/2019
X
Post commercial marine vessel shapefile fractions to CHIEF
9/30/2018
X
EPA 2017 landing/takeoff data available for SLT review period
10/2018
X
EPA-Estimated 2017 EGU Emissions posted
12/2018
X
Submission Window Closes for Point, Onroad Mobile, Nonroad Mobile and Events
data categories
1/15/2019
X
X
X
EPA provides feedback to SLT on data completeness and outliers for Point, and
Onroad/Nonroad. Window open on a case by case basis for corrections only.
1/15/2019 -
3/15/2019
X
X
X
Nonpoint survey and emissions -if not using Cat 3 tools- due
3/31/2019
X
EPA provides feedback to SLT on data completeness and outliers for Nonpoint.
Window open on a case by case basis for corrections only.
2/15/2019-
6/15/2019
X
Post draft EPA fire estimates to 2017 NEI website
5/15/2019
X
Review Period for EPA EVENT draft emission estimates and submission of updated
activity data/comments, draft data posted 5/19, comments through 6/2019
5/1/2019 -
6/30/2019
X
2017 draft NEI Release in EIS for all data categories except Category 3 nonpoint
5/15/2019-
6/15/2019
X
X
X
X
Window to be opened for EVENTS as needed after review of draft data.
5/15/2019-
7/01/2019
X
EPA solicits corrections on case by case basis.
5/15/2019-
7/31/2019
X
X
X
SmartFire2 rerun to include comments/corrections received above and bringing in
other activity datasets not in Phase 1 (due to resources) and FETS data
7/15/19-
8/22/19
X
Review period for SmartFire2 re-run ("quick review" needed; more detailed review
will be reserved for after vl is done and those comments will be incorporated into
the v2 Events inventory)
8/24/2019-
8/31/2019
X
EPA-Estimated "final" Event Emissions available in EIS
9/1/2019
X
Review and finalization of all EVENTS data
9/15/2019
X
2017 vl NEI Release in EIS for all data categories except nonpoint
7/15/2019 -
9/15/2019
X
X
X
2017 vl NEI Release in EIS for nonpoint
12/31/2019
X
2017 vl Public Release
1/31/2020
X
X
X
X
Window Opens for 2018 NEI Submission Period for Point sources only
10/1/2019
X
Window Closes for 2018 NEI Submission Period (Point sources)
1/13/2020
X
2018 vl NEI Release in EIS for Point sources
7/13/2020
X
2017 v2 NEI Release in EIS for all data categories
TBD
X
X
X
X
2017 v2 Public Release
TBD
X
X
X
X
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2.1 What are the key 2017 NEI due dates for my agency?
More details on the nonpoint schedule will be provided in Section 5. Listed here are key dates for SLT
actions.
Due Date
SLT Milestone Item
September 1, 2017
Comments on this NEI plan
November 30, 2017
Inputs for nonpoint Category 1 EPA tools sent by SLTs1
January 31, 2018
Deadline for comments on nonpoint draft Category 2 EPA tools
June 30, 2018
Inputs for nonpoint Category 2 EPA tools sent by SLTs1
November 30, 2018
Deadline for comments on nonpoint draft Category 3 EPA tools
January 15, 2019
Point, onroad, nonroad and event emissions or inputs (mobile) data are
due.2 All Nonpoint emissions for non-Category-3 sectors are due if not
using EPA tools. For EVENT fires, see schedule for submissions of activity
data, we strongly encourage SLTs to submit activity data and not
emissions for EVENTS.
March 31, 2019
Deadline for sending nonpoint survey and nonpoint emissions (if not
using EPA Category 3 tools) for Category 3 sectors 2
May 31, 2019
Inputs for nonpoint Category 3 EPA tools sent by SLTs1
July 31, 2019
Deadline for sending corrections of 2017 NEI draft for all sources
except Category 3 nonpoint for inclusion in 2017 NEI vl
November 30, 2019
Deadline for sending corrections of 2017 NEI draft for Category 3
nonpoint sectors for inclusion in 2017 NEI vl
TBD
Corrections of 2017 NEI vl due for including in 2014 NEI v2 are due
1 Inputs for nonpoint category emissions tools are not required to be sent to the EPA by the AERR. These tools are
encouraged for use by SLTs for improving emissions calculations using consistent and defensible methods. SLTs who
choose to have the EPA calculate their nonpoint sector data using these tools would need to send that data by the
date(s) shown to participate. Otherwise, SLTs may submit emissions data on the AERR required scheduled.
2 The regulatory deadline for emissions data and model inputs is December 31, 2018. However, the EPA provides a
grace period because of the holidays at the end of the season, and also has later dates for some sectors to allow
time for some nonpoint sectors that have underlying data available at later dates.
2.2 How will agencies make data corrections to the NEI data during the QA
period?
EPA inventory developers will work with SLT agency staff to provide feedback on their data and allow
corrections on a case by case basis. Corrections will be done similarly to what was done for the 2014 NEI
vl review during early 2016. SLT agencies will submit their corrections to the EIS "QA Environment" and
select "Request Assistance" on their clean feedback report. EPA staff then will review the corrections and
submit them to the Production Environment on the SLT's behalf or open the window for SLT submission
to Production.
2.3 Why has EPA eliminated wholesale data replacements?
EPA inventory developers do extensive QA on data received by the submission due date. Allowing
wholesale replacements, or initial submissions long past the original due date, causes EPA staff to run the
complete QA procedure on all data again. This process delays the NEI release, increases EPA's use of
resources, and does not have a greater benefit than the correction process that we described above. This
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change places a lot of importance on the end of the submission grace period on January 15th 2019. It is
very important that SLTs meet this deadline.
2.4 What best practices will help my agency meet the deadlines in this schedule?
To assist you in allocating your time and resources to complete this requirement, we are including a
suggested timeline for the facility, point and nonpoint data categories in "Appendix 1 - Suggested SLT
Timeline and QA Checks" on the 2017 National Emissions Inventory Documentation website. Also,
included in Appendix 1 are suggested QA reports to run upon completion of your production
submission. To take advantage of these reports, your data will need to have been submitted early
enough that you can check for data quality and adjust your previously submitted file. Remember that
when submitting corrections to your emissions data that you must report the full suite of pollutants and
not just the pollutant emissions needing correction.
3 General changes to the 2017 NEI process
This section provides some general changes to the 2017 NEI process that effect all or several data source
categories. The subsequent sections of this plan include additional information regarding sector-specific
changes.
3.1 AERR
While the AERR requirements result in a December 31, 2018 deadline for submitting the 2017 NEI data,
we understand the difficulties this presents to SLTs agency staff due to holiday schedules. Therefore, we
are proposing an additional two-week grace period that will end on January 15, 2019. In addition, as
discussed in Section 5.4, we are conditionally extending the deadline for some key nonpoint sectors
(which we denote as Category 3) that are covered by EPA tools and rely on point inventory subtraction.
3.2 EIS Reporting Codes
EIS code tables that have been updated, or will be updated before October 2017, are listed below; these
code changes are provided in separate worksheets in the "Appendix 2 -2017 NEI Plan Code Changes"
workbook on the 2017 National Emissions Inventory Documentation website. Refer to the "readme"
spreadsheet in Appendix 2 for information on each of these code change spreadsheets, including an
initial release date, a last updated date, spreadsheet description, and a field describing updates, or
expected updates, to the initial spreadsheet. As these updates become available, we will update both
the Appendix 2 worksheet(s) and will send emails to the existing NEI/EIS listserv contact list -consisting
primarily of EIS inventory developers for each agency.
1. Control Measure Codes: We expect to receive and post new codes by mid-July 2017. The
spreadsheet will be updated at that time.
2. Unit Type Codes: An initial set of new unit type codes are provided in red font in the spreadsheet.
We will add additional new codes later in July 2017 for Printing, Refineries and Waste Disposal.
New codes for Pulp and Paper are also planned but timing is unknown.
3. Source Classification Code (SCC) Changes
a. Point: There have been several changes since the 2014 NEI that are already in the EIS SCC
table. In addition, we are currently reviewing point SCCs from Risk and Technology Review
(RTR) rules for Printing, Refineries and Waste Disposal sources. We will update this
spreadsheet in Appendix 2 once we have these proposed SCC changes. Potential future
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changes to SCCs from other RTR rules that could happen in the next three years are listed
in "Appendix 3 - Draft Schedule for Potential Point SCC Revisions" on the 2017 National
Emissions Inventory Documentation website. If any SCC revisions from these reviews
occur before the submission deadline, we will update the Appendix 2 spreadsheet. There
will be an opportunity to comment on any of these SCC changes if and when they happen.
b. Nonpoint: Many SCCs are proposed to be retired, and several new SCCs either need to
be created on brought back from retirement. Most of the SCCs we are proposing for
retirement were not used by SLTs in their 2014 submittals, and those that were can be
mapped to different existing SCCs. The primary reason for removing these extraneous
SCCs is to prevent possible double-counting of emissions and confusion over what the
SCC is intended to capture. One of the new sources that we are considering adding under
Ag livestock is silage emissions. These emissions (primarily VOCs) occur mostly at dairy
farms, where silos are used to store grain used as feed for livestock. While there are some
methods in the literature (for California) that we can consider, how to apply it to the
entire US will be a challenging, considering the activity data available for the entire nation.
We will continue to work with SLTs to better understand and potentially inventory this
source in the 2017 nonpoint NEI, using a new yet-to-be-created SCC.
c. Events: For 2017, we are considering adding an SCC in EVENTS separately for pile burns.
But before we can do that, we need to develop a method and default activity parameters
for it in the modeling platform we use to develop fire emissions for the NEI. We request
that agencies stay tuned on how we proceed with including this potential new
source/SCC.
d. Onroad: No new SCCs are expected
e. Nonroad: New SCCs for MOVES are expected but timing is unknown.
4. Pollutant Codes
a. Recent efforts to incorporate test data from regulations into EIS have resulted in the
need to revisit the current pollutant codes. The rule data require a more expansive list
than the current EIS list. To allow for future selections to include these data, we may
make changes to the pollutant table. Discussions are currently underway on which
changes will be needed to support rule data and if these will affect agency submissions.
These changes would result in additional pollutant codes and would not result in retiring
any pollutant codes.
b. Eighteen (18) Glycol Ether pollutants are no longer classified has HAPs but have been
changed to a classification of "OTH". Theses pollutants did not meet the CAA definition
of glycol ether established by the final rule "Redefinition of Glycol Ethers Category
under Section 112(b)(1) of the Clean Air Act and Section 101 of the Comprehensive
Environmental Response, Compensation and Liability Act (40 CFR 63)". We chose to
allow agencies to continue reporting these to prevent unimportant EIS error messages;
however, these 18 pollutants will not be selected for the 2017 NEI because they are not
HAPs. The only "OTH" pollutant to be selected for the 2017 NEI is hydrogen sulfide.
c. For the 2014 NEI, we added 5 PM2.5 species (EC, OC, N03, S04 and PMFINE) and 2 diesel
PM species to the NEI that are generated only by EPA through PM speciation. These
pollutants will also be in the 2017 NEI but as with 2014, they cannot be reported by SLT.
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5. NAICs Codes: NAICS codes have been adjusted to reflect the 2017 US Census Bureau updates
for 2017. Three-digit NAICS codes will no longer be able to be submitted.
While the above is the extent of known retired and additional codes, new codes for these and other EIS
datasets may be added later in the year if deemed necessary. No codes will be retired afterthe publication
of the final version of this plan expected by mid-September, 2017.
3.3 Expected Pollutants
SLT agencies have requested that EPA provide a list of expected pollutants by process (SCC), and we
provided these for the point and nonpoint data categories in preparation for the 2014 NEI. For the 2017
NEI cycle, the EPA will provide an updated list for nonpoint sources. These lists of expected pollutants
should be available on the 2017 National Emissions Inventory Documentation website by the end of
October, 2017 for point, nonpoint and event data categories.
The reporting of criteria air pollutants (CAPs) is required under the AERR for all data source categories,
while the reporting of hazardous air pollutants (HAPs) is not. However, HAPs are critical to complete the
NEI, and will be supplemented by EPA if SLTs do not provide these data, and therefore, HAPs will also be
included in these lists.
An SLT's agency data submittal will not be considered "incomplete" if it does not voluntarily report HAP
emissions, but it will be augmented with EPA estimates of HAPs from this list using EPA data augmentation
procedures.
The purpose of the expected pollutants list depends on the data category. Each data category is discussed
in the following subsections.
3.3.1 Point
For point sources, the expected pollutants list is a guide for agencies based on the following criteria:
1. The pollutant contributes at least 0.1% to the total emissions nationally at that process, and
includes an existing emissions factor (e.g., AP-42), OR
2. The pollutant contributes at least 0.01% to the total emissions, 75% of the processes for a given
SCC include the pollutant -with a minimum sample size of 3 processes, and the SCC does not
include a nebulous catch-all "Other" in the description;
3. Mapping to other similar-fuel SCCs for fuel combustion only.
Therefore, the expected pollutants list for point sources should be regarded as a guide for prioritizing core
pollutants to QA. If the core HAPs are not submitted, they will be generated via SLT-submitted VOC or PM
values via HAP augmentation. The database providing the HAP augmentation factors is in the Emissions
Inventory System Gateway. This database may be updated if new factors are available or where errors are
found. The version of the database to be used for the 2017 NEI will be finalized by 1/15/2019. Additional
SLT-submitted pollutants not in the expected pollutants list will likely end up in the NEI.
3.3.2 Nonpoint
One of the goals in developing the NEI is to have as cohesive and congruent of a picture of the air
pollutants in the nation for a particular inventory year. In order to create this cohesiveness, EPA has to
treat data in a consistent way when emissions data submitted by states looks too large in comparison to
the rest of the data, or incorrect. Therefore, for the nonpoint sources, the expected pollutants list will
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have a more active role in what ends up in the NEI, and a set of business rules has been proposed to
streamline this process. The expected pollutants list will be developed from all 2014v2 NEI EPA estimates
and will include HAPs and CAPs that EPA will gapfill if these data are not submitted by the SLT agencies. If
EPA does not estimate emissions for a particular source type, there will be no expected pollutants list for
comparison, as EPA acknowledges that those source categories that are not estimated on a national basis
are not well-assessed by EPA at this point in time.
For the expected pollutants list, all pollutants for each nonpoint SCC will be provided and a statistical
county-level outlier check will be developed to provide meaningful expected maximum values for each
SCC/pollutant/county where EPA develops estimates. We will map expected pollutants to most active
SCCs in sectors where EPA estimates exist for other like-process/fuel SCCs based on data in the existing
EIS HAP Augmentation table. It should be noted that EPA may not have adequate data to provide feedback
on whether these data exceed our threshold for outliers, since EPA will not have estimates for these
particular SCCs themselves.
For the 2017 NEI, we are proposing the following set of business rules to be used in conjunction with the
nonpoint expected pollutants list:
Item
If an agency submits...
EPA will...
Unless...
1
Emissions that exceed EPA
expected outlier check values
Use EPA estimates in lieu of
SLT data
State provides supporting
material on how the emissions
were estimated, including
activity and emission factor
details where available.
2
Pollutants not in expected
pollutant list
Remove these pollutants
(e.g., VOC from road dust,
metals from evaporative
processes)
SLT provides documentation on
these unexpected pollutants
3
VOC but no HAPs
Run HAP augmentation off
of the SLT-submitted VOC,
and this data will take
precedence over any EPA
tool data
The VOC submitted falls outside
of EPA's expected outlier check.
4
Total VOC-HAPs > VOC
(the sum of all of the HAPs
that are VOCs adds up to
more than the submitted VOC
value)
Remove all state submitted
VOC-HAP data and instead,
use HAP augmentation off of
state VOC
5
VOC and different VOC-HAPs
than our expected pollutant
list
Gap fill using HAPs
generated by HAP
augmentation off of the SLT
VOC value
The sum of augmented + SLT-
submitted VOC-HAPs adds up to
more than the VOC value; (see
4 above); in this case, all SLT
HAPs will be removed and
replaced with HAP
augmentation off of the state
VOC
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Item
If an agency submits...
EPA will...
Unless...
6
An incomplete set of expected
criteria pollutants
Supplement using EPA tool
data for the pollutants that
are not submitted
SLT provides documentation to
why those emissions should not
exist.
7
VOC data for different SCCs,
but similar process
characteristics to what EPA
uses
EPA will augment VOC-HAPs
with similar profiles
State also submits HAPs with
that VOC
For item 1, regarding emissions greater than outlier checks, the intention is to prevent inconsistencies
when looking at the nation as a whole, which may not really exist, and may instead be due to a mistake in
calculations or data entry. EPA will initiate a dialogue with reporting agencies where submitted emissions
exceed expected ranges, particularly for rapidly-changing sectors such as oil and gas. These outlier checks
will be based on county-SCC-pollutant level statistical analysis of the EPA estimates generated for the
2014v2 NEI. Supporting documentation requirements are not intended to be onerous, but can serve as a
path for EPA to get confirmation that SLTs intend for significantly larger than expected emissions to be
included in the NEI, may help inform EPA's tools, and can allow EPA to revise the outlier checks where
needed.
Item 2, regarding unexpected pollutants, is intended to prevent inconsistencies or incongruent data from
showing up in the inventory, which may not be "real." Sometimes an agency submits pollutants that no
other state agency reports, and this may appear as an anomaly on the map for a particular pollutant when
looking at a source category as a whole. For example, one state agency reported lead as a pollutant from
commercial cooking. While this may be a real pollutant from the restaurant griddles, it also may be a
miss-assigned SCC or pollutant code. In any case, if EPA deems it an "unexpected pollutant," EPA may not
have a good emission factor or may not have the data to support that a certain pollutant is part of a source
category. In these cases, when comparing the EPA dataset to SLT datasets, a hotspot may show up,
highlighting the submitting state, in this example, as the only place in the country where you could find
lead being emitted from restaurants.
Item 3, regarding VOC submitted without their corresponding HAPs, is straightforward; the goal is to fill
in missing HAPs in the inventory where EPA expects them to exist but they were not provided by the
submitting agency. HAP augmentation on SLT-submitted VOC will be used when it does not exceed the
outlier check and VOC is reported but VOC-HAPs are not. Item 1 would apply where the outlier check is
violated.
Item 4, regarding VOC-HAPs summing to greater than VOC, is the broad check for where the sum of all
SLT-submitted VOC-HAPs must be less than SLT-submitted VOC. EPA is conducting this analysis to prevent
nonsensical data, since the parts should not add up to more than the whole. If a violation occurs, SLT-
submitted VOC is retained, but all SLT-submitted VOC-HAPs are not used (tagged out) and replaced with
HAP augmentation VOC-HAPs.
Item 5, regarding different HAPs being reported than EPA's expected pollutants, builds off item 4 in
complexity, dealing with the messy scenario where we end up with a mix of SLT-reported VOC-HAPs and
VOC-HAPs from HAP augmentation. Like item 4, the intention is to prevent nonsense data where the parts
sum up to more than the whole. This happens when SLTs submit VOC and some but not all expected VOC-
HAPs, and HAP augmentation, based on SLT-submitted VOC, is used to "gap-fill" the remaining unreported
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VOC-HAPs. It is understandable that SLTs may only have emission factors for some VOC-HAPs and that the
method may be different from the VOC emission factor. However, air quality modeling based on the NEI
assumes a level of VOC-HAP to VOC mass closure. Therefore, if SLTs do not want EPA to generate "missing"
VOC-HAPs, they should submit emissions for VOC-HAPs that are in the expected pollutants list. SLT could
submit zero emissions if these pollutants are not emitted from these processes in a particular area due to
controls, bans or other location-specific information.
Item 6, regarding missing criteria pollutants, is intended to provide a cohesive inventory; for example, if
NOx is not submitted for a combustion category, EPA has the need to gap fill. This rule is simply a
reflection of how the NEI has been built in the past: SLT data takes precedence over EPA-submitted
emissions. If EPA data exist for pollutants that SLTs do not submit, then EPA data "gap fills" and appears
in the NEI selection. If SLTs do not want EPA data, that are in the expected pollutants list, to appear in the
NEI, they have a couple options:
1. Submit emissions, which could be zero if these pollutants are not emitted from these
processes in your jurisdiction for these "expected" pollutants, to ensure EPA emissions data
do not appear in the NEI, or
2. Contact EPA to request removal (tag-out) of EPA emissions for these pollutants, if they are
not emitted.
Option 1 is more automated and easier to track. This item is most important for CAPs and "high risk" HAPs.
Option 2 has been the standard approach in previous NEI cycles; however, it complicates QA and has led
to numerous errors in the past.
Item 7, regarding running HAP augmentation on similar SCCs to those for which EPA has profiles, is also
intended to fill missing pollutants in the inventory, and this has been standard procedure in previous NEI
cycles. Where SLTs report emissions for SCCs that EPA does not report, EPA data will be used if SLTs do
not report all pollutants, and this goes beyond just HAP augmentation for VOC-HAPs.
None of these business rules impact what is stored in the EIS for each agency-only what will appear in
the NEI selection. EIS reports run off of SLT datasets will still capture what SLTs submit. However, the final
2017 Inventory will reflect a converged set of data, with EPA tool data, SLT submitted data, and
augmentation datasets included.
3.3.3 Mobile and Events
Onroad and nonroad expected pollutants are the CAPs and HAPs generated by MOVES.
The expected pollutants for the EVENTS category are those that we estimate in EPA's methods. It is
expected that this list will remain the same as it was for the 2014 NEI. That list can be found in Section 7
of our 2014 NEI Technical Support Document.
3.4 EIS QA Checks
A list of QA checks performed on data submittals can be found in the Emissions Inventory System
Gateway. The following additional QA changes are being proposed for the 2017 NEI cycle.
1. Additional critical QA checks.
a. New requirement for reporting "heat values" when SLTs report events inputs -see
Section 7.2.2.
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b. "CURIES" is now the only unit of measure allowed for radioactive pollutants.
2. Additional warning QA checks. There are no new warning checks.
3. Update from Warning to Critical
Check 511 - Release Point Stack Diameter Measure Range will be upgraded from warning
to critical. We may also consider changing the ranges based on what we use for
modeling/NATA (National Air Toxics Assessment). The ranges used for modeling which
we are considering for the QA check are:
NEI Parameter
Acceptable Range
Stkhgt
Between 1.64 ft (0.5 m) and 16732.28 ft (5100 m)
Stkdiam
Between 0.0328 ft (0.01 m) and 328.08 ft (100 m)
Stkvel
Between 0.000328 ft/s (0.0001 m/s) and 984.252 ft/s (300 m/s)
Stktemp
Between 8.3 F (260 K) and 3140.33 F (2000 K)
4. Deleted QA checks
a. Check 1152 - Release Point Exit Gas Velocity Measure Critical Range - duplicate check
of checks 512 and 517
b. Check 1153 - Release point Exit Gas Flow Rae Measure Critical Range - duplicate
check of checks 518 and 519
c. Check 2211 - Release Point Exit Gas Temperature Measure Outer Range - duplicate
check of check 511
5. Compare agency-submitted data to values in new protected point source data fields
(Critical). For the 2014 NEI cycle the site latitude and longitude fields could be locked by EPA
after verifying values.
These checks will not cause an error to be reported if the data value being submitted is the same
as the protected data value. These checks are also only run on production submissions; therefore,
the errors will not be included in feedback from the QA environment. We are applying this same
process to latitude and longitude protected data, which should reduce the number of messages
under the "protected data" tab of your feedback reports. Only the data in the protected field will
be rejected and other data will be accepted into EIS. When locked data do in fact need to be
revised (an actual revision), SLT agency staff should contact NEI staff to resolve the discrepancy.
This change will go into effect starting with the 2013 submission period and continuing for the
2014 NEI and beyond.
The remaining changes pertain only to fires in both the Nonpoint and Event data categories:
6. Check for valid Emission Calculation Method Code (Critical) - When reporting emissions for
SCCs 2810001000, 2811015000, and 2811020000 in the Event Inventory, data submitted will
be required to use either Emissions Calculation Method Code 40 - Emission Factor based on
Regional Testing Program; 41 - Emission Factor based on data available peer reviewed
literature; or, 42 - Emission Factor based on Fire Emission Production Simulator (FEPS).
7. Check for present Event Staging Code (Critical) - Event Staging Code has been raised to a
"critical" check, making this data field required.
8. Check for valid Event Staging Code (Critical) - Event Staging Code will be limited to reporting
combinations of Flaming (F) and Smoldering (S); S and Both (B); F and B; or F, S and B for the
same reporting period. The reporting of a single staging code will be rejected, e.g. Report
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only flaming without either smoldering or both will reject the flaming record for that reporting
period.
9. Ensure Activity values are reported (Critical) - For all SCCs with a Tier 3 description of
Agricultural Fires, the following EIS fields will now be required: Calculation Parameter Type
Code (I), Calculation Parameter Value (number of acres burned), Calculation Parameter Unit
of Measure (Acre), and Calculation Material Code (Ill-Fire). See Appendix 4 in the 2014 NEI
Plan on the 2014 NEI Documentation website for these SCCs.
3.5 EPA Completeness Feedback
The NEI data are the foundation for key EPA regulatory and other analyses. Due to the importance of this
inventory, the EPA will again provide completeness reports. In the 2017 NEI cycle, the completeness
reports will be available through the EIS Gateways to SLT agency staff and the EPA regional offices.
Allowing SLT agency staff to run these reports themselves will provide SLTs with the greatest possible time
to address any incomplete findings. SLT agencies will only be able to see completeness reports for their
own agency and delegated agencies. With the release of the 2017 NEI, letters based on the final
completeness reports will also be provided to state and local Air Directors.
The completeness checks will be based on the following criteria:
Point:
1. Check that all facilities with an operating status of OP (Operating) have been reported. This
will be done using the Agency Submission History Report available on the EIS Gateway.
2. Percent of completeness based on SCC/expected CAPs. Voluntary HAP data submission will
be noted, though lack of HAP data will not count against a completeness percentage. These
checks will be available via a completeness report function on the EIS Gateway.
Nonpoint:
1. Completion of a nonpoint survey.
This survey will be greatly simplified from that which was implemented in 2014. At this time,
we expect it will only have one question with a few choices of answers: either EPA should
supplement the SLT submission or not, on an SCC basis. The reasons for not supplementing
would either be 1) SLT does not have this type of source in the state (i.e., no coal fired
residential boilers) or 2) SLT covers this category in point (i.e., gas stations are all covered in
point in the state of Colorado). This nonpoint survey is still being developed, in conjunction
with the Option Group/Option Set functionality, which when run properly in EIS, will eliminate
duplicates from overlapping nonpoint SCCs.
2. Percent of completeness based on SCC/expected CAPs.
Voluntary HAP data submission (or acceptance of EPA data) will be noted, though lack of HAP
data will not count against a completeness percentage. These checks will be available via a
completeness report function on the EIS Gateway.
Onroad/Nonroad:
1. Completeness is based on an agency either submitting inputs or accepting EPA estimates.
Events:
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1. Completeness is based on an agency either submitting inputs or accepting EPA estimates. In
the cases where they do submit emissions, completeness will be based on them submitting
all the pollutants we estimate in EPA's methods. This includes CAPs, HAPs, and GHGs.
Additional efforts to provide fire activity data from state forestry programs will be noted.
The table below provides an example feedback table that would be compiled from the EIS completeness
reports and included in the letters to the Air Directors. Ongoing work to resolve the details on the final
feedback letter may change this example.
Data Category
Status
Percent
Complete1
Voluntary
HAP level2
What to do
Point sources
75% of facilities
reported
60%
Modest
Report remaining facilities or
indicate facility shutdowns.
Reporting all expected criteria
pollutants for reported SCCs or
correct SCCs.
Nonpoint sources
Survey submitted,
Data partly complete
80%
High
Report remaining expected
criteria pollutants for SCCs
reported.
Onroad mobile
sources
Inputs not provided
0%
No data
Submit model inputs or accept
EPA inputs/emissions.
Nonroad equipment
sources
Inputs not provided
0%
No data
Submit model inputs or accept
EPA inputs/emissions.
Events
Inputs provided
EPA data accepted
100%
High
1 Based on expected SCC/pollutant combinations for pollutants required by the Air Emissions Reporting Rule.
2 Level as compared to all other agencies submitting data. High = Submitted and highly complete; Modest = Between 40% and
70% expected HAPs provided for SCCs reported; Low = few SCCs reported with HAPs or less than 70% of expected HAPs for
SCCs reported; No data = no HAP data or model inputs were reported.
4 Point sources
4.1 Overview
Air agency point source data are the predominant source of point source data in the NEI. Point source
reporting includes both the "facility inventory" and "emissions" as separate reporting steps, each with
their own set of tables defined for electronic reporting. The following subsections provide a road map to
the requirements from the AERR and the best practices for submitted data. Additional subsections
provide specific information on point-source specific practices for the 2017 NEI, including a discussion
on how EPA intends to include Greenhouse Gas (GHG) emissions for 2017 and treatment of point
fugitive parameters in EIS for modeling.
As in past NEI cycles, the EPA intends to augment state point source emissions when needed. In past
cycles, the augmentation has included PM augmentation, HAP augmentation (factors to ratio HAPs from
CAPs), chromium speciation, and including emissions from TRI.
4.2 AERR requirements
Please refer to 40 CFR Part 51, Subpart A for the point source submission requirements. Key
requirements for your attention include:
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• The data fields required by the AERR are provided in Table 2a and 2b to Appendix A of the
AERR. While EIS does not enforce the reporting of all required data fields, air agencies are
legally obligated to report the required fields. The field definitions are provided in Section 51.50
of the AERR.
• The point source reporting thresholds specified as part of Section 51.50 definition of point
sources. The emissions thresholds are specified as "potential to emit" emissions and are lower
for sources within nonattainment area boundaries for ozone, PMio, and CO nonattainment
areas. As noted above, the reporting threshold for lead emissions as point sources is 0.5 tons
per year of actual emissions.
• Obtain the latest reporting codes from EIS prior to compiling point source data. In particular, for
the 2017 NEI cycle, some codes have changed (see Section 3.2).
4.3 Inclusion of Greenhouse Gas emissions for point sources
The 2014 NEI included emissions for some Greenhouse Gases (C02, CH4 and N20) in some data
categories (on-road, non-road and events). For point sources, EIS has included an emissions data set
containing the point source GHG (C02, CH4, N20 and SF6) emissions as reported by facilities to the EPA
GHG Reporting Program (GHGRP) beginning with the 2013 emission year. These GHGRP emissions were
not included in the published 2014 NEIs. For the 2017 NEI, we plan to include point source emissions of
those four GHGs in the published NEI. The primary source of the selected GHG data will be the direct
facility reporting to the GHGRP. We will also use S/L/T reports of the same four GHGs if they have been
reported for facilities which do not appear in the 2017 GHGRP data. We expect that any such S/L/T
reports which are so used will be for smaller emitters of GHGs, given the reporting requirements of the
GHGRP. We will use the GHGRP data preferentially over S/L/T-reported data because the GHGRP data is
required of the facilities, the calculation procedures have been prescribed by regulation, and the facility-
reported data is reviewed by the EPA GHGRP before publication. Note that we are not requiring S/L/Ts
to report GHGs to EIS for any facilities, but we plan to include any voluntarily reported S/L/T point
source data in the NEI if it appears to be valid and if we do not have any GHGRP data for that facility.
For 2017 we plan to use as a minimum the facility-level totals for each of the four GHGs. We will
investigate using unit-level emissions for C02 where they are available from the EPA CAMD emissions
reporting system. As with the 2014 GHGRP C02 data stored in EIS, we will store the facility-level
biogenic C02 emissions at a separate EIS emission process ID from the non-biogenic emissions. The
biogenic emissions process will also be described with a different SCC (39999998) from the non-biogenic
emissions (39999999) to facilitate differentiation in EIS reports. As with the earlier years, we will
convert the values as published on the GHG Reporting Program Data Sets website from CQ2-equivalent
mass to actual mass, for consistency with the rest of the NEI and its applications. The conversion factors
used for 2014 were obtained from Table 1 of the IPCC's Fourth Assessment Report (25 for methane, 298
for nitrous oxide, 22,800 for sulfur hexafluoride), per the documentation given on the GHG Reporting
Program web page.
A cross-walk of which GHG facility IDs correspond to which EIS Facility IDs for the purposes of writing the
GHGRP emissions values into EIS is available in EIS. The GHGRP facility IDs are stored as Alternate
Facility IDs for each EIS facility. These Alternate Facility IDs can be seen on the EIS Gateway screens for a
particular facility, or a bulk report can be obtained from EIS by using the Facility Configuration reports,
Alternate Facility IDs, and filtering for Program System Code = "EPAGHG". The 2014 GHGRP facility
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summary file contained 7289 facilities as identified by the GHG Facility ID. Of those 7289 GHG facilities,
5396 have been matched to EIS facility IDs. In some cases, more than one GHG facility was matched to a
single EIS facility ID. In those cases, the sum of the multiple GHG facilities will be written to the EIS
facility. Based on the 2014 reporting year, 95 percent of the total C02 reported to the GHGRP is
matched and stored to an EIS facility. We will review the 2017 GHGRP facility summary file when it is
available to update the EIS crosswalk for any additional facilities that can be matched with reasonable
certainty. We do not plan to add GHGRP facilities that cannot be readily matched as new EIS facilities,
based upon the limited additional GHG emissions that would be accounted for by these facilities and the
increasing possibility that the facility may be accounted for in EIS in some fashion by S/L emissions
submittals, whether as point, non-point, or non-road sources. Based upon the 2014 datasets it appears
that the largest reporters of C02-equivalent that cannot be found in EIS are underground coal mines.
These sources can emit enough methane to surpass the GHGRP minimum thresholds without having
much criteria air pollutant emissions. We do not plan to attempt to calculate GHG emissions for EIS
facilities where we have neither a GHGRP value nor a S/L/T value. While combustion C02 emissions
might be reasonably estimated if provided a valid annual fuel throughput, we do not believe that the
ElS-reported fuel throughputs should be relied upon without significant new QA review, particularly for
the smaller combustion sources that would not already be matched to a GHGRP facility. An
augmentation of C02 or CH4 emissions based upon a ratio to NOx, CO, or other ElS-reported criteria
emissions would likely be extremely uncertain given how much larger C02 emissions would be than the
criteria pollutants and how variable the ratios might be given the sensitivity of the criteria pollutants to
controls or operational parameters. We will look for S/L/T reported facilities with NOx emissions greater
than some threshold where we would expect a GHGRP value but none is available, and if the NOx
emissions and throughput are verified we may add a C02 emissions estimate.
4.4 Source characterization of fugitive sources
New for 2017 will be clarifications on how we characterize fugitive emission release point types. This set
of instructions are used to improve air dispersion modeling in support of the National Air Toxics
Assessment (NATA). The OA check that restricts the fugitive angle measure, EIS variable "Fugitive Angle
(DEG)", to between zero (0) and 89 degrees of rotation; no longer 180 degrees. This forces the lat/lon
coordinates for the fugitive release point to be located at the most western corner, where the angle is
measured clockwise from true (not magnetic) north, the "Fugitive Length (FT)" EIS variable is the
measure along the side that would run North-South if the angle was 0 degrees and the "Fugitive Width
(FT)" EIS variable is the measure along the side that run in the East-West direction if the angle was 0
degrees. In the example below, the release point coordinates are located at the push pin, the width is
680 feet, the length is 1897 feet and the angle is 22 degrees.
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4.5 Point source best practices
The EPA encourages the use of the following best practices when submitting emissions of point sources.
• Collecting data from facilities:
o Require or request that facilities use test data to estimate emissions for their processes.
Where test data are not available, require or request facilities use the provided emission
factors compendium when estimating their emissions (see Section 4.6) in lieu of Web
FIRE factors where noted,
o Require that facilities use the latest EIS reporting codes. Download these as described
above and make them available to your facilities,
o For FIAPs, encourage facilities to compare their FIAP submissions to what has been
submitted to TRI. While the EPA prefers the HAP emissions for the NEI because it is at a
more detailed process level, the facility-level TRI data and the NEI data should sum to
the same values. We will likely be including additional, smaller TRI facilities into the
2017 inventory; therefore, we expect additional scrutiny will be needed to examine for
double-counts with existing agency-submitted facilities.
• Building your inventory:
o Use consistent identification codes from one year to the next (e.g., facility, unit, release
point, and process identifiers). This prevents the creation of duplicate facilities or sub-
facility records, which reduces subsequent steps needed to remove such duplicates. If
needed, work with your information technology department to update your data
system to make these changes,
o Provide control information whenever possible, making sure that it is complete. The
control data are required by the AERR (when controls are present), and the EPA uses the
control data to assess future possible controls as a demonstration of whether and how
future NAAQS can be attained,
o Use the expected pollutants list (see Section 3.3) to help prioritize your efforts and QA.
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• Reporting best practices:
o Plan to start your submission process at least 4-8 weeks prior to the deadline,
accounting for time away from the office for holidays,
o Submit the facility inventory data for only those facilities or parts of facilities that have
changed since the previous time the facility inventory data were provided,
o Make sure to also submit updates to the "Operating Status Code" for facilities that are
no longer operating or no longer required to report as point sources. This will impact
your completeness report since facilities which have a Facility Site Status Code of OP
(Operating) that have not submitted emissions will be counted as incomplete,
o Submit data to the EIS QA Environment prior to submitting data the Production
Environment. Make sure your feedback reports are clean prior to submitting to the
Production Environment,
o QA your data after submission to Production (see Appendix 1)
o Run the completeness report and update your submission to meet or exceed all
completeness criteria.
4.6 Mercury and Air Toxics Standard (MATS) Data
For the 2014 NEI the EPA made available via the 2014 NEI Documentation website the average emission
factors developed from the MATs testing done for several HAPs at electric generating units (EGUs). We
made available our assignment of those bin-average emission factors to each of the EGUs covered by the
MATs rule for consideration by the SLTs in their review for the best estimation method available for their
facilities. The MATS testing was performed in 2010 and covered mercury, lead, several other metals, and
HCI and HF acid gases. The assignments of the averaged emission factors to individual units was reviewed
and revised by the EPA for the 2011 NEI, based on controls believed to be in place at that time.
The EPA encourages SLTs to review whether the MATs-based emission factors are still applicable to the
units in their jurisdiction, and to use those emission factors unless they have more recent site-specific
data on which to base an emission estimate. The EPA believes the MATs-based emission factors are more
representative of emissions from these units than the published AP-42 emission factors or metal content
equations. The EPA will make estimates of these unit emissions based upon the MATs emission factors
and reported heat inputs for 2017. These estimates will be compared to the SLT-reported values to
identify any large discrepancies which may need resolution.
Please indicate your review and evaluation of the most current emission factor materials for these units
by using the emissions calculation method code "9" if you are using one of these bin-average emission
factors. The EPA will interpret emission calculation method code "8" (USEPA Emission Factor) to mean
that you are using the outdated published AP-42 emission factor for these units. Whether you use the
MATS emission factor or your own site-specific assessment, please also fill in the emission factor field and
its associated numerator and denominator fields.
5 Nonpoint sources
5.1 Overview
Air agency nonpoint source data is an important source of data in the NEI, particularly for those
nonpoint categories that have overlap with point sources. Nonpoint sources include (but are not limited
to) fuel combustion categories; oil and gas production; industrial, commercial and consumer solvents;
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residential wood combustion; road and construction dust; and agricultural emissions sources. The EPA
provides a large number of spreadsheets and database tools intended to be used by SLT agencies to aid
in the calculation of their nonpoint emissions, though the use of the EPA tools is not a requirement. The
following subsections provide a road map to the requirements from the AERR and the best practices for
submitted data. Additional subsections provide specific information on an updated nonpoint source-
specific process using a category survey for the 2017 NEI.
As in past NEI cycles, the EPA intends to augment state nonpoint source emissions when needed. The
nonpoint tools that EPA develop also serve a secondary purpose: to provide fallback data for the EPA to
use where SLTs do not submit adequate data to the inventory. Further, augmentation of SLT data also
includes PM augmentation, HAP augmentation (factors to ratio HAPs from CAPs), and chromium
speciation.
5.2 AERR requirements
Please refer to 40 CFR Part 51, Subpart A for the nonpoint source submission requirements. Key
requirements for your attention include:
• The data fields required by the AERR are provided in Table 2b to Appendix A. While EIS does
not enforce the reporting of all required data fields, air agencies are legally obligated to report
the required fields. The field definitions are provided in Section 51.50 of the AERR.
• Obtain the latest reporting codes from EIS prior to compiling nonpoint source data. In
particular, for the 2017 NEI cycle, some codes have changes (see Section 3.2).
5.3 Nonpoint source best practices
The EPA encourages the use of the following best practices when submitting emissions of nonpoint
sources.
• EPA's nonpoint emissions tools:
o EPA encourages SLT agency staff to participate in the review and development of the
nonpoint emissions tools, datasets, and Nonpoint Emissions Methodology and Operator
Instructions (NEMO). The EPA will be continuing Nonpoint Method Advisory (NOMAD)
workgroups focused on method improvements and documentation in the tools,
including the request for SLT-submitted activity data where available,
o After the tools or datasets are released, the EPA encourages states to review the
available documentation and use the tools to estimate their emissions. Alternatively, if
no changes are needed to these EPA defaults, SLT air agencies can indicate to EPA
(through the survey response) their interest in accepting the EPA defaults as their NEI
emissions estimate.
• Provide an accurate and timely nonpoint survey response.
• Building your inventory:
o Provide control information whenever possible, making sure that it is complete. The
control program data are required by the AERR (when control programs are present),
and EPA uses the control data to assess future possible controls as a demonstration of
whether and how future NAAQS can be attained,
o Use the expected pollutants list (see Section 3.3) to help ensure complete coverage and
reduce mixing of EPA and SLT-submitted data where possible.
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o Use the information provided to EPA in the 2017 nonpoint survey (see Section 5.4.4) to
make sure to report those categories that you indicated you have in your state,
o Focus on categories that require point/nonpoint reconciliation since the EPA cannot do
this reconciliation without state input. These efforts will help prevent missing emissions
or double counting of emissions.
• Reporting best practices:
o Plan to start your submission process at least 4-8 weeks prior to the deadlines for each
data category (see Section 5.4.1), accounting for time away from the office for holidays,
o When submitting emissions, submit data to the EIS QA Environment prior to submitting
data the Production Environment. Make sure your feedback reports are clean prior to
submitting to the Production Environment,
o QA your data after submission to Production (Appendix 1)
o Run the completeness report and update your submission to meet or exceed all
completeness criteria.
5.4 Nonpoint process changes for 2017
The 2017 nonpoint data category will be complied in a much different manner than the 2014 NEI. We
are staggering the schedule for EPA estimates development and review by utilizing an EIS feature called
Option Group/Option Set. The purpose of this enhancement is to minimize the need for "tagging" out
data that would otherwise lead to double-counting, automating the process of selecting data based on
overlapping SCCs. EPA hopes that utilizing this process will greatly simplify the nonpoint survey, both in
the number of questions an SLT needs to answer as well as EPA's interpretation of the results.
5.4.1 New staggered schedule for submissions
One of the biggest challenges with the nonpoint data category has been managing the release of the
"final" EPA estimates (and tools). For the 2017 NEI, EPA has decided to divide the tools into three
categories on differing schedules. This will allow for EPA and the NOMAD Committee to spend the
greatest resources and most time on the most important and complicated tools. This staggered schedule
will allow more focus on specific nonpoint tools in discrete timeframes during the 2017 NEI
development cycle, and will avoid dumping an overwhelming number of new and revised EPA estimates
at once on the SLT inventory developers. The three categories are defined as:
Category 1. Sources that do not require point inventory reconciliation (subtraction) and where
the existing methodology is expected to have minimal changes, and thus, extensive additional
resource investment is less important than other sources. In general, any updated activity data
between a draft and final NEI would have minimal effect on the resulting emissions, and
therefore, these tools can be finalized earlier in the NEI process. EPA will release these tools for
comment and finalize them first in the succession of the 3 categories.
Category 2. Sources that do not require point inventory reconciliation, but where the existing
methodology is in need of updates, and thus, more extensive collaboration with SLTs on
methodology and tools are needed than Category 1 tools. Many of these tools have undergone
recent significant methodology changes in the 2014 NEI cycle, or are expected to undergo
significant revisions for the 2017 NEI via coordination with targeted NOMAD subcommittees.
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EPA will release these tools for comment after Category 1 tools, but prior to Category 3 tool
development.
Category3. Sources that require point inventory reconciliation. These tools are last in the
staggered schedule because, while methodology can be locked in prior to NEI development,
properly subtracting point data generally must wait until the 2017 point data (activity or
emissions depending on the tool) are available. These tools will be pre-populated with latest
available activity/emissions data to facilitate methodology and draft estimate review prior to
the 2017 point NEI being made available. The tools will then be finalized after the 2017 point
NEI data are successfully loaded.
It is important to note that EPA will accept SLT inputs for these tools on this staggered schedule. SLTs are
also able to run the final VI tools and/or submit their own estimates by the extended AERR-based
deadline, January 15th 2019. EPA will provide the templates for activity input submissions.
The following is the schedule for all NEMOs, including interim milestones of draft tool/estimates release,
SLT comment period deadline, Version 1 tool tool/estimate release, and final NEI estimates:
Category 1 NEMO
Tools/Estimates
EPA Tool or
Stand-alone
Database?
EPA posts
draft tool/
estimates
SLT
comments
due
EPA VI
Tools
posted
VI tools
Finalized
Milestone Goals
3/31/2017
5/31/2017
8/31/2017
1/31/2018
Ag Pesticides
Tool
Y
Y
Ag Tilling
Tool
Y
Y
Asphalt Paving
Tool
Y
Y
Aviation Gas Distribution Stage
1
Tool
Y
Y
Aviation Gas Distribution Stage
2
Tool
Y
Y
Composting
Tool
Y
Y
Construction Dust: Residential
Tool
Y
Y
Construction Dust: Non-
Residential
Tool
Y
Y
Construction Dust: Road
Tool
Y
Y
Mining & Quarrying
Tool
Y
Y
Open Burning: Land Clearing
Debris
Tool
Y
Y
Open Burning: Municipal Solid
Waste
Tool
Y
Y
Open Burning: Yard Waste
Tool
Y
Y
Residential Charcoal Grilling
Tool
Y
Y
Residential Heating -Non-wood
Tool
Y
Y
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Category 2 NEMO
Tools/Estimates
EPA Tool or
Stand-alone
Database?
EPA posts
draft tool/
estimates
SLT
comments
due
EPA VI
Tools
posted
VI tools
Finalized
Milestone Goals
10/31/2017
1/31/2018
3/31/2018
9/30/2018
Ag Dust (from hooves)
Tool
Ag Fertilizer
database
Ag Livestock
database
Ag Fires, including rangeland
database
Ag Silage
TBD -New
for 2017
Biogenics
database
Commercial Cooking
Tool
Human Cremation (non-Hg)
Tool
Nonpoint Mercury (inc. human
cremation)
Tool
Portable Fuel Containers
database
Publicly-Owned Treatment
Works (POTWs)
Tool
Road Dust: Paved and Unpaved
Tool
Commercial Marine Vessels
database
Locomotives
database
Category 3 NEMO
Tools/Estimates
EPA Tool or
Stand-alone
Database?
EPA posts
draft tool/
estimates
SLT
comments
due
EPA VI
Tools
posted
VI tools
Finalized
Milestone Goals
8/31/2018
11/30/2018
2/28/2019
8/31/2019
ICI Fuel Combustion
Tool
Oil and Gas Production &
Exploration
Tool
Solvents
Tool
Stage 1 Gasoline Distribution
Tool
5.4.2 New SCCs, proposed retirements, and proposed un-retirements
Analysis of the 2014 NEl, EPA and SLT-submitted data and all active and retired nonpoint SCCs identified
several issues with the list of active SCCs. Appendix 2 contains a complete list of all SCCs that we
propose retiring, new SCCs needed, and SCCs that are currently retired but should be made active again.
Reasons for retiring SCCs vary but include, but are not restricted to:
• Consistency where similar SCCs have already been retired. For example, Industrial Fuel
Combustion, Natural Gas "All IC Engine Types" is already retired, but "All Boiler Types" is
currently active, along with the general "Total: Boilers and IC Engines". We propose retiring "All
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Boiler Types". Other examples are various solvent types in lieu of "Total: All Solvent Types"; no
SLT submitted emissions for most of these SCCs in 2014.
• Remove possibility for double-counting. Too many overly-specific options for some source
categories, or conversely, overly-broad "catch-all" SCC descriptions can make automated
reconciliation of EPA and SLT data difficult to QA. Examples of overly-broad SCCs abound,
including Oil and Gas "All Processes: Total: All Processes" -in this case, should all SLT and EPA
data for all other oil and gas SCCs be considered a double-count?
• If there are instances where we have an SCC that neither EPA uses nor any SLTs, that would be
another reason
New SCCs are needed for several reasons:
• For sectors like agricultural livestock and fertilizer application where, EPA utilizes offline models
to create aggregate emissions -by animal type for livestock and a "bidirectional flux" model for
fertilizer application. For example, EPA estimates for livestock waste, beef (and all other model-
based animals) are currently assigned to a "Not Elsewhere Classified" SCC because a beef
"Total" All Processes" does not exist.
• Similarly, where we do not have a "Total", SLTs appear to be assigning emissions to a specific
SCC and EPA emissions for other specific SCCs are used. We suspect this is happening in sectors
like Commercial Cooking.
• Where new sources are being estimated. Examples include dust kicked up by hooves and feet
for various animal types and agricultural silage.
We plan to un-retire a few SCCs because we've identified new methods for estimating emissions at
these specific SCC descriptions, or, SLTs have requested the ability to use these SCCs.
5.4.3 Utilization of EIS Option Group/Option Set feature to compile NEI
The EIS has an Option Group/Option Set (OG/OS) feature that we will implement for the 2017 nonpoint
NEI. The Option Group covers a group of three or more nonpoint SCCs where potential double-counts
can exist. Not all nonpoint SCCs will be assigned to an Option Group. The Option Set is the hierarchy for
selecting emissions within that Option Group, where, if emissions are reported for all SCCs, some
emissions will be removed from the NEI to prevent potential double-counting. Option Set "A" would be
used instead of Option Set "B".
A simple example of an Option Group would be Distillate Oil from Industrial Fuel Combustion (leading SCC
description "Stationary Source Fuel Combustion: Industrial: Distillate Oil:":
Option Group
Option Set
SCC
Description
Ind Dist ICI
A
2102004000
Total: Boilers and IC Engines
Ind Dist ICI
B
2102004001
All Boiler Types
lnd_Dist_ICI
B
2102004002
All IC Engine Types
In this case, if an agency reports emissions for all 3 SCCs, only emissions from Option Set = "A" are used.
We can, and do, assign Option Sets where specific SCCs are given preference over the more general SCCs
as well. A proposed list of OG/OS assignments for all nonpoint data category SCCs is provided in the
"Appendix 4 - 2017 Nonpoint Proposed OptionGroup-OptionSet" workbook on the 2017 National
Emissions Inventory Documentation website.
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5.4.4 Revised nonpoint survey
Because each agency has their own universe of sources and inventory development approaches, each
agency reports nonpoint estimates a little differently. The nonpoint survey will gather information
specifically for each SLT regarding which source categories are covered by point, nonpoint, or both, and
about where point source reconciliation needs to be done to nonpoint activity. The survey allows us to
determine what it means when a SCC is missing from an SLT submittal. It could mean one of three
scenarios: 1) the agency accepts EPA data, 2) the agency covers that source in the point data category,
or 3) that those sources/processes are not present in that agency's locale.
The nonpoint survey was first implemented in 2014, but will be greatly simplified for the 2017 submittal
process. Implementing the previously discussed OG/OS feature will automate how EPA data are used to
gap-fill SLT submittals. One of the primary purposes of the nonpoint survey in 2014 was to prevent EPA
double-counting emissions in sectors where SLTs and EPA report emissions for different SCCs but for
similar processes. A draft version of the new nonpoint survey will be released in January2018, months
before the nonpoint submittal window opens. EPA anticipates finalizing the nonpoint survey before the
SLT submittal window opens in June 2018. At this time, EPA expects that the nonpoint survey will be
reduced to the following question for each SCC where EPA generates estimates:
Do you want to use EPA estimates for this SCC?
• No: We have this source and will submit data; We do not have this source; or, We
completely cover this source in the Point inventory
• Yes
The nonpoint survey will default to "yes" for all sources except for "Industrial and
Commercial/Institutional Fuel Combustion" (ICI), which will default to "no". This has the following
consequences:
• If SLTs do nothing in the nonpoint survey, EPA estimates will be used where computed and
where SLTs do not submit emissions in that Option Group. For example, if you submit some
type of woodstoves with inserts (EPA SCC or not), your SLT emissions will be used and EPA
emissions will not; however, if you neglect to submit any emissions for this Option Group, EPA
estimates will be used (gap-fill). This is an important distinction: if you submit emissions for an
Option group, they will be in the NEI unless you actively remove them from your data, or
contact EPA prior to the submittal deadline to request EPA remove ("tag-out") your data. For QA
reasons, EPA prefers less tagging then necessary.
• If you indicate "no" in the nonpoint survey, EPA emissions will not appear in the NEI for the
Option Group. You must select one of the 3 reasons for not accepting EPA estimates. (SLT
estimates, it doesn't exist in nonpoint, or it doesn't exist in geographical agency location.)
• The survey response will default to "no" in the nonpoint survey for ICI because:
• We expect you to submit emissions using point subtraction from SLT submittals and
• We expect nonpoint emissions for virtually every county.
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6 Mobile sources
6.1 Overview
Mobile sources are sources of pollution caused by vehicles transporting goods or people (e.g., highway
vehicles, aircraft, rail, and marine vessels) and other nonroad engines and equipment, such as lawn and
garden equipment, construction equipment, engines used in recreational activities, and portable
industrial, commercial, and agricultural engines.
The EPA creates a comprehensive set of mobile source emissions data for criteria, hazardous air
pollutants, and greenhouse gasses for all states, Puerto Rico, and U.S. Virgin Islands as a starting point of
the NEI. The EPA uses models to estimate emissions for most of the mobile source categories. With the
exception of California, the EPA requires SLT agencies to submit MOVES model inputs where applicable,
rather than emissions, so that the EPA can use those inputs if MOVES is updated and for consistent
future year mobile source projections.
6.2 AERR requirements
For onroad and nonroad, state and local agencies are required to submit MOVES model county data
bases (CDB) inputs. They may choose to submit emission in addition. The exceptions are tribes and
California, who may submit emissions only.
6.3 Mobile source best practices
The EPA encourages the following best practices when submitting onroad/nonroad mobile data:
• Look for and follow posted directions on how to submit mobile inputs. Inputs are required for
all sources in MOVES: all onroad vehicles and nonroad equipment.
• Submit both the required input data, and any supplemental documentation, to help support and
explain your input information. The EPA will provide instructions regarding how to provide any
supplemental documentation prior to the June 2018 opening of the EIS submission window.
6.4 Onroad process changes for 2017
The EPA will continue to use MOVES for the 2017 NEI for both onroad and nonroad emissions, the exact
version will be determined prior to the submittal window opening in June 2018.
Collection of inputs, rather than emissions, is required to provide EPA the ability to run varying model
scenarios and future projections from the same input basis. Model input data collection will be like the
process used for the 2014 NEI. The EPA is interested in comments on the current MOVES input process
in planning improvements for the 2017 NEI cycle.
6.1 Nonroad inputs
For the 2017 inventory cycle and beyond, only MOVES input format (CDB) will be accepted.
6.2 Commercial marine vessels changes
As with the 2014 NEI, the EPA will post shape-fraction files to aid agencies that have CMV emissions at
the county-level and wish to allocate them to shapes based on EPA's values. If SLTs have more detail
than EPA's shapes, they may contact us to update the shape files to include new ones.
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6.1 Rails changes
For the 2017 inventory cycle, we will return to county-based processes for in-line rail emissions,
dropping the use of shape IDs. Rail yards will still be at the facility-level.
7 Events
7.1 Overview
As proposed, the revised AERR does not require SLT agencies to report emissions from wildfire or
prescribed burning sources. These sources are reported as events to EIS. Thus, for the purposes of this
plan, the approaches described here assume use of the event format and voluntary participation from
SLT agencies to help EPA to create the most accurate inventory of these sources.
Air agency EVENT (day-specific emissions from wildfire and prescribed burning sources) data is an
important source of data in the NEI, as many pollutants such as PM, VOCs and numerous HAPs are
emitted in significant amounts by the large fires. For EVENTS, the EPA provides a default dataset that
covers the entire U.S. States should carefully check these emissions and strongly consider accepting
them before making a decision to submit emissions on their own. The EPA prefers to use consistent
methods and pollutants where possible, so working with EPA to have the best estimates possible and
then accepting EPA's estimates are an ideal approach. After review of EPA's final EVENT emissions (after
provision of activity data), if an Agency deems it absolutely necessary to submit emissions, then care
must be exercised to keep the pollutant coverage the same as what EPA estimates using its methods.
7.2 Event process changes
For the 2017 NEI process, we expect the following items to be new/changed from the 2011 NEI process:
• Similar to the 2014 NEI, we continue to strongly-encourage SLTs to submit activity data and NOT
emissions for this data category. While we do encourage all SLTs to submit only activity data, a
couple of states do continue to submit emissions for this category.
• In the 2017 NEI, more parameters will be required if SLTs submit data to this category, including
heat content ("Heat Release" and "Heat Release UOM") for each fire as well as other
parameters needed for emissions modeling of these fires. It's also possible that we update PAH
EFs for these fires in the 2017 NEI.
• Those Agencies that decide to submit emissions data, must submit smoldering and flaming
emissions (the sum represents what has been required in the past (see Section 3.4). The
smoldering and flaming components individually are important for many activities including use
of data for climate assessments, because the PM2.5 chemical composition is different for the
smoldering vs. the flaming component.
• We will review the possibility of including lead (Pb) as a pollutant from these large fires in the
2017 NEI. If we adopt an EPA method for Pb in the 2017 NEI, agencies that decide to submit
actual emissions data should also plan on submitting Pb emissions. An emissions factor and
procedure for estimating Pb emissions from PM2.5 fractions will be provided by the EPA as
needed.
• SLTs that submit emissions must also submit HAPs, GHGs, and PM species as reported in EPA
data for EVENTS. EPA will provide the requisite EFs.
• Agencies should make it clear to the EPA that the activity data they are submitting is a complete
set for both prescribed and wild fires. In that way, the EPA will ensure no other default data is
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brought into the process of estimating emissions for the SLTs in question if such a note is
included as part of the activity data submission. EPA will add more details on this to the plan at
a later time, but it's expected we will do it via a survey administered by USFS as was done in the
2014 NEI.
• As discussed earlier in this plan, it's possible we introduce a new SCC for pile burns in the 2017
NEI for EVENTS. If we do that, SLTs that submit emissions must submit to that SCC to fires they
consider to be pile burns. It's expected the list of pollutants will be the same for piles as for wild
and prescribed fires.
• We encourage agencies to send in activity data beginning in January, 2018 so that we can start
incorporating that data into estimating emissions for a draft version of the EVENTS inventory, which
we expect will be released by the summer of 2018. The EPA will post instructions on this process on
the 2017 website in December, 2017. We strongly encourage all agencies to review and comment
on the draft EVENTS NEI that we expect to post in the summer of 2015. This includes review and
use of the activity data submitted by various agencies.
7.3 Event source best practices
• Submit activity data so that the EPA does not have to use default data to identify and estimate
emissions from fires occurring in your domain. Important parameters include acres burned, fire
perimeters, fuel loading, and fuel consumption; however, acres burned is the most important
activity data to submit. The EPA relies on the default methods from satellite detections without
more specific data. The importance of submitting activity data is especially true for prescribed
fires, because the EPA methods have a more difficult problem in identifying which fires are
prescribed fires for appropriately estimating the emissions. At this time, we expect that activity
data for the 2014 NEI fires will simply be submitted via email to Tesh Rao
(rao.venkatesh@epa.gov), and the EPA will provide directions if those plans change.
• Review draft NEI for EVENTS soon after it is available. Ensure that submitted activity data were
used appropriately. Provide comments in the comment time period specified by the EPA.
• If an Agency decides to submit actual emissions (EPA discourages this process for EVENTS),
provide documentation on the methods as much as possible either via comment fields in EIS or
via an email to Tesh Rao at rao.venkateshffiepa.gov. Also, if an Agency submits emissions,
ensure that the pollutant coverage is the same as what the EPA estimates using its methods. If
Emission Factors are needed, please contact the EPA. If you do decide to submit emissions,
o Submit data to the EIS QA Environment prior to submitting data the Production
Environment. Make sure your feedback reports are clean prior to submitting to the
Production Environment,
o Use the new (expected) comparison report as an additional QA step (see Section 8.3)
• Please plan on reviewing the draft estimates that will be provided by EPA and submitting
appropriate comments. In addition, please work with EPA to submit and review your activity
data as EPA processes them into emissions.
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8 EIS Gateway, Reports, and Tools
8.1 Staging Tables
To assist in resolving Bridge Tool errors, we built queries into the staging tables that identify widows and
orphans, which can prevent your data from converting to the required XML format. We updated the
Bridge Tool in March of 2015 to provide error messages to be more informative.
For users of Windsor Solutions' inventory management product "SLEIS", the Bridge Tool has been adapted
to convert the XML export files from SLEIS into the staging tables without prior manual manipulation. Past
versions of the Bridge Tool could not convert the XML to the staging table format.
8.2 Submissions - EIS Multi-thread Approach
To prevent a backlog of submissions during peak periods, the EPA plans to create a "multi-thread"
approach to the submission process within the EIS. This multithread approach will establish two
submission threads, with each thread being a separate data processing pathway. With the new approach,
the EIS will automatically move files larger than a pre-assigned file size limit to another thread, allowing
smaller files to be processed simultaneously. Currently, larger files must be completely processed before
the smaller files will be processed. This change will be in the EIS software, so the only differences users
will notice is faster response times.
8.3 Reports
A new report is now available in EIS. The new report is a comparison report that will allow you to compare
any number of datasets against a single, user-specific base dataset. This could be used, for example, to
compare point emissions in the NEI 2014 v2 against your agency submitted data for 2017. An additional
example would be to compare your submitted data against TRI data so that you can see what facilities
have reported to TRI and what is being reported by your agency. The comparison reports will provide an
absolute difference, percent difference and ratio between the baseline data value and the comparison
value for each dataset being compared. We encourage SLT air agencies to take advantage of this report
after having made your submission as an additional QA tool.
In addition, another report will be available for assessing whether your submissions have met the 2017 7
NEI completeness criteria. The use of this completeness report is described in Section 3.5.
9 Conclusion
The EPA has created this plan to assist SLT agencies with their own planning needs for the 2017 NEI
cycle. Please direct comments on this plan to Rich Mason at mason.richffiepa.gov. The EPA recognizes
that SLT air agency staff will have many questions, ideas, and improvements that we have not addressed
here, and your comments will help us improve this plan and the 2017 NEI process.
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