Emissions Factors Program Improvements, 52723-52734 [E9-24684]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 74, Number 197 (Wednesday, October 14, 2009)]
[Proposed Rules]
[Pages 52723-52734]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E9-24684]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 60, 61, and 63

[EPA-HQ-OAR-2009-0174; FRL-8968-8]
RIN 2060-AP63


Emissions Factors Program Improvements

AGENCY: Environmental Protection Agency (EPA).

ACTION: Advanced notice of proposed rulemaking.

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SUMMARY: The purpose of this Advanced Notice of Proposed Rulemaking 
(ANPRM) is to convey issues raised by stakeholders about EPA's 
emissions factors program, inform the public of our initial ideas on 
how to address these issues, and solicit comments on our current 
thinking to resolve these issues. Our goal is to develop a self-
sustaining emissions factors program that produces high quality, timely 
emissions factors, better indicates the precision and accuracy of 
emissions factors, encourages the appropriate use of emissions factors, 
and ultimately improves emissions quantification.
    Although initially developed for emissions inventory purposes only, 
use of emissions factors has been expanded to a variety of air 
pollution control activities including permitting, enforcement, 
modeling, control strategy development, and risk analysis. This ANPRM 
discusses the appropriateness of using emissions factors for these 
activities.

DATES: Comments must be received on or before November 13, 2009.

ADDRESSES: EPA has established a docket for this action under Docket ID 
No. EPA-HQ-OAR-2009-0174. All documents in the docket are listed in the 
Federal Docket Management System index at https://www.regulations.gov. 
Publicly available docket materials are available either electronically 
through https://www.regulations.gov or in hard copy at the EPA Docket 
Center, Public Reading Room, ANPRM Docket, EPA West, 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.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2009-0174. The U.S. Environmental Protection Agency's (EPA's) policy is 
that all comments received will be included in the public docket 
without change and may be made available online at https://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 https://www.regulations.gov or e-
mail. The https://www.regulations.gov Web site is an ``anonymous 
access'' system, which means EPA will not know your identity or contact 
information unless you provide it in the body of your comment. If you 
send an e-mail comment directly to EPA without going through https://www.regulations.gov, your e-mail 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, 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 EPA cannot read your comment due to technical difficulties 
and cannot contact you for clarification, 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 EPA's public docket, visit 
the EPA Docket Center homepage at https://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the https://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 https://www.regulations.gov or in hard copy at the Public Reading 
Room.

FOR FURTHER INFORMATION CONTACT: Mr. Thomas A. Driscoll, Measurement 
Policy Group (MPG), Office of Air Quality Planning and Standards (D243-
05), Environmental Protection Agency, Research Triangle Park, North 
Carolina 27711, telephone number: (919) 541-5135; fax number: (919) 
541-1039; e-mail address: driscoll.tom@epa.gov.

SUPPLEMENTARY INFORMATION: 
    Outline. The information in this preamble is organized as follows:

I. General Information
    A. Does this action apply to me?
    B. What should I consider as I prepare my comments for EPA?
    C. Where can I get a copy of this document and other related 
information?
II. Background Information
    A. The Role of Emissions Factors and Stakeholder Comments
    B. Overview of the Emissions Factors Improvement Program
    C. Goals for the Emissions Factors Improvement Program
III. Emissions Factors Development Process and Tools
    A. WebFIRE
    B. Electronic Reporting Tool (ERT)
    C. Emissions Factors Development Guidance
IV. Changes to the Emissions Factors Program, Emissions Factors 
Development, and Associated Tools
    A. Potential Revisions to the Emissions Factors Development 
Process: Overview and Issues
    B. Test Data Submittal Requirements
    C. Emissions Factors Content and Format
    D. Interacting with the SPECIATE Database

[[Page 52724]]

V. Request for Comment and Next Steps
VI. Statutory and Executive Order Reviews

I. General Information

A. Does this action apply to me?

    This notice is likely to be of interest to a variety of parties, 
including owners and operators of stationary sources who use emissions 
factors and, in particular, those that are subject to source testing 
requirements under EPA air rules (i.e., New Source Performance 
Standards (NSPS), National Emissions Standards for Hazardous Air 
Pollutants (NESHAP), and Maximum Achievable Control Technology (MACT) 
standards); industry sectors that believe that the emissions factors 
currently used to characterize their emission sources could be updated 
and improved; industry sectors that currently lack emissions factors; 
State, local, and tribal air pollution control agencies (S/L/Ts) and 
other individuals and organizations with an interest in emissions 
factors. In that the use of emissions factors has expanded beyond 
developing emissions inventories to other uses (e.g., developing 
emissions limits for incorporation into New Source Review (NSR) and 
Title V operating permits, determining applicability to air pollution 
regulations, determining compliance with emissions standards, 
conducting air quality impact analyses, developing control strategies, 
and performing risk analyses (i.e., section 112(f) residual risk 
requirements)), S/L/Ts, industry representatives, environmental action 
groups, individuals and other organizations may have a vested interest 
in this notice.
    All of these parties are encouraged to read this notice and to 
submit comments for EPA's consideration. We realize that in many cases 
organizations other than EPA develop emissions factors for a variety of 
purposes, and, in most cases, we do not require the use of EPA 
emissions factors. However, because the EPA factors are so broadly used 
and accepted, we are soliciting information and feedback on how they 
are developed, currently used, and how they can be improved.

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

    Do not submit CBI to EPA through https://www.regulations.gov or e-
mail. Clearly mark the part or all of the information that you claim to 
be CBI. For CBI information in a disk or CD-ROM that you mail to EPA, 
mark the outside of the disk or CD-ROM as CBI and then identify 
electronically within the disk or CD-ROM the specific information that 
is claimed as CBI. In addition to one complete version of the comment 
that includes information claimed as CBI, a copy of the comment that 
does not contain the information claimed as CBI must be submitted for 
inclusion in the public docket. Information so marked will not be 
disclosed except in accordance with procedures set forth in 40 CFR part 
2.

C. Where can I get a copy of this document and other related 
information?

    In addition to being available in the docket, an electronic copy of 
this notice will be available on the Worldwide Web through the 
Technology Transfer Network (TTN). The TTN provides information and 
technology exchange in various areas of air pollution control. 
Following signature, an electronic version of this document will be 
posted at https://www.epa.gov/ttn/oarpg under ``Recent Additions.''

II. Background Information

A. The Role of Emissions Factors and Stakeholder Comments

    An emissions factor is a representative value that attempts to 
relate the quantity of a pollutant released to the atmosphere with an 
activity associated with the release of that pollutant. These factors 
are usually expressed as the mass of pollutant divided by a unit mass, 
volume, distance, or duration of the activity emitting the pollutant 
(e.g., kilograms of particulate emitted per megagram of coal burned). 
Such factors facilitate estimation of emissions from various sources of 
air pollution. In most cases, these factors are simply averages of all 
available data of acceptable quality that were collected through source 
performance testing, and are generally assumed to be representative of 
population averages for all facilities in the source category.
    Quantifying air emissions is a vital aspect of all air pollution 
programs. Emissions factors have long been a fundamental tool in 
developing national, regional, state, and local emissions inventories 
for air quality management decisions and in developing emissions 
control strategies. More recently, emissions factors have been applied 
in determining site-specific applicability and emissions limitations in 
operating permits by federal agencies, S/L/Ts, consultants, and 
industry. These users have requested guidance on the use of emissions 
factors and other emissions quantification tools (e.g., emissions 
testing and monitoring, mass balance techniques) in developing permits 
that are more practical in their enforcement.
    Under ideal circumstances, all emissions data users would quantify 
emissions from ongoing operations with continuous emissions monitoring, 
periodic emissions performance testing, or frequent calculation using 
well-accepted engineering principles, such as mass balances or other 
detailed engineering calculations. Because these methods can be time 
and resource intensive, users sometimes do not have or are unable to 
secure data sufficient to allow detailed site-specific emissions 
determinations. In some cases, measurement via instruments or long-term 
performance testing, which would provide such data, is not feasible or 
too costly. Without such data, emissions factors, which are assumed to 
be representative of population-average values, are frequently used, 
along with production information as a quick, low-cost method to 
estimate emissions.
    EPA's Office of Air Quality Planning and Standards (OAQPS) has long 
recognized the importance of emissions factors and has focused effort 
and resources on developing and documenting emissions factors. The EPA-
approved emissions factors are contained in an online document called 
the ``AP-42 Compilation of Air Pollutant Emissions Factors'' (hereafter 
referred to as ``AP-42'') available at https://www.epa.gov/ttn/chief/ap42/. The document is organized into 15 chapters that 
describe industrial emission sources and the derivation of industry-
specific emissions factors. Many of the individual sections of this 
document are supported by an associated background report providing 
summaries of the individual test data and a corresponding assigned 
quality rating, the rationale for grouping and using individual data, 
and the assignment of the factor and factor quality.
    Emissions factors were originally established only for use in 
estimating emissions for developing national emissions inventories. 
However, as mentioned earlier, emissions factors are used for many 
other air pollution control activities for which they were not 
designed.
    AP-42, which was developed by OAQPS, is not the only repository of 
emissions factors. Emissions factors have been developed for a number 
of other programs and there are other databases that contain emissions 
factors. For example, EPA's Office of Atmospheric Programs has recently 
proposed a greenhouse gas reporting rule and provided many emissions 
factors for sources to use in assessing their emissions. In addition, 
EPA's Office of Research and Development

[[Page 52725]]

administers the SPECIATE database that contains many emissions factors. 
Because the applications, uses, and requirements of these other 
emissions factors databases are different than AP-42, these databases 
have operated in a fairly autonomous manner. However, we are seeking 
comment on whether there should be more interaction among these 
databases. For a discussion of SPECIATE, see section IV.D.
    As part of a reevaluation of the emissions factors program, EPA 
interviewed and surveyed various emissions factors users and held a 
series of workshops in 2003 and 2004 with stakeholders to solicit their 
input on what is needed to update and improve the emissions factors 
program.\1\ First and foremost, stakeholders (industry, S/L/Ts, EPA 
program offices, environmental action groups, and others) indicated 
that EPA needs to continue to maintain the AP-42 factors information 
compilation and retrieval system. In addition, they indicated that it 
takes EPA too long to develop emissions factors, that data submitted 
for regulatory development have not been used to develop new emissions 
factors, that there have been several inappropriate uses for emissions 
factors, and that, in general, EPA is not developing new emissions 
factors. The stakeholders said that EPA should develop criteria to 
address the development and uses of emissions factors for purposes 
other than just emissions inventory development, such as for use as 
screening tools for compliance determinations, applicability purposes, 
and preparing air program permit applications. They also said that the 
current program is unresponsive to their needs, too complex for their 
active participation, and lacks transparency concerning data 
manipulation. More recently, the National Academy of Sciences (NAS) 
(see National Research Council of the National Academies, 2004, Air 
Quality Management in the United States, Washington, DC: The National 
Academies Press) and EPA's Office of Inspector General (OIG) (see U.S. 
EPA, Office of Inspector General Evaluation Report: EPA Can Improve 
Emissions Factors Development and Management, Report No. 2006-P-00017, 
March 22, 2006) also reviewed and commented on the emissions factors 
program. Their comments echoed those of all other stakeholders in that 
the EPA must continue to maintain the emissions factors program, but it 
must be improved to support EPA and stakeholder uses. They also noted 
that EPA should quantify uncertainty to improve emissions factors and 
that EPA should be developing and updating emissions factors regularly.
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    \1\ A copy of the draft report, Emissions Factors Program 
Improvement Efforts (September 2005), is available on EPA's Web site 
at: https://www.epa.gov/ttn/chief/efpac/workshops/efp_improvement_efforts_draft.pdf.
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B. Overview of the Emissions Factors Improvement Program

    Based on the results of the emissions factors reevaluation process 
that included collecting stakeholder input, preparing an improvement 
plan, and an internal effort to review and reexamine our efforts, we 
have identified four focus areas for improvement that are the basis for 
this action:
     Designing a process for developing and improving emissions 
factors to allow easier and more effective participation by interested 
parties, to be open and transparent, to accommodate the continuing 
(self-sustaining) development and improvement of factors rather than 
being a large, one-time effort to address the current needs, and to 
provide an electronic mechanism for test report submittal and review. 
We want to develop a process that, at the end of the emissions factors 
development, will result in high quality emissions factors.
     Improving methods for compiling and providing emissions 
factors data and other pertinent information to users, including 
complete and easy access to all available test data.
     Developing guidance on the application of EPA's default 
emissions factor or the selection of a more appropriate emissions 
factor for specific applications, calculating emissions factors from 
available test data or other information, conducting emissions tests to 
facilitate the development of emissions factors, and evaluating and 
considering data quality.
     Updating existing emissions factors and developing more 
factors where gaps currently exist.
    EPA intends to implement a multi-part process to improve the 
emissions factors program. The first part involves further development 
of the existing electronic reporting tool (ERT) to make it easier for 
S/L/Ts, industry, and other stakeholders to plan, document, accept, 
assess, and transmit emissions test data. The second part involves 
upgrading the AP-42 factors information system into WebFIRE. WebFIRE is 
an Internet-based application that compiles and retrieves emissions 
factors and performance test data and information; making it an 
interactive, up-to-date, and easy to expand and enhance replacement for 
the current AP-42. Additionally, to make the emissions factors 
development process easier and more transparent, EPA plans to rewrite 
the existing emissions factors development procedures and reissue the 
revised document following a public review and comment process. 
Finally, in order to acquire adequate data for the development or 
improvement of the emissions factors, we are considering requiring the 
submission of certain performance testing information by industry to 
EPA's OAQPS via electronic reporting. Implementing this multi-part 
effort will result in a self-sustaining emissions factors program 
receiving ongoing data submittals to improve emissions estimation for 
regulatory authorities and others to use in: (1) Developing emissions 
inventories, (2) updating emissions standards, (3) identifying and 
evaluating control strategies, (4) determining applicability of permit 
and regulatory requirements, (5) assessing risks, and (6) conducting 
other air pollution control activities. We believe this effort will 
reduce the burden of handling test data, while improving access to and 
the utility of the data.

C. Goals for the Emissions Factors Improvement Program

    We believe the critical element in improving the emissions factors 
program is changing the role of OAQPS from sole developer of emissions 
factors to a facilitator who provides stakeholders with the tools to 
participate in all aspects of the process, generates tools that capture 
the existing work performed by stakeholders and enhance consistency 
across the program, audits and oversees the program, and develops 
policies for the appropriate use of emissions factors in non-inventory 
applications where there are no policies or where existing policies are 
inadequate. To this end, we encourage collection and submission of 
critical site-specific process and testing information that will allow 
stakeholders to improve the predictive accuracy of emissions factors 
and characterize the associated uncertainties. We also want to 
encourage and facilitate the electronic documentation and transfer of 
source test information to reduce stakeholder workload, ease 
assessment, increase communications, establish consistency (content and 
assessment), increase the transparency of the entire program, and 
provide information transfer to critical air programs (emissions 
factors development, compliance verification, emissions inventory, 
permitting, etc.).
    Finally, we currently are considering replacing the highly 
subjective manual method of updating all emissions factors

[[Page 52726]]

for a source category with a more consistent, objective, and automated 
system that better delineates source descriptions so that emissions 
factors' source categories are more meaningful and useful. Guidance is 
a critical part of developing emissions factors. As such, we are 
updating guidance of procedures for preparing emissions factors to make 
the procedures clearer, improve the predictive accuracy of the 
resulting emissions factors, improve stakeholders' confidence in the 
revised process, and help us achieve our overall goals of improving the 
emissions factors program.

III. Emissions Factors Development Process and Tools

    We seek to replace the manual emissions factor development process, 
which is shown in Figure 1. The manual emissions factors development 
process begins with the performance and documentation of source tests 
at individual facilities. After obtaining the report of the source 
test, the emissions factors developer (EPA) assesses the documentation 
with respect to its representativeness to the source category and its 
precision and accuracy of quantifying the facility's emissions. Test 
reports are then grouped by process (using the source classification 
code, or SCC), control device employed, and pollutant. These groupings 
are reviewed to combine related processes and control technologies that 
will result in comparable data being used to establish or revise 
emissions factors. After making determinations about the use of data 
with differing test report quality ratings, the emissions factors are 
calculated (or recalculated) with an associated factor quality rating. 
The public is notified of the availability of the draft factors and is 
given an opportunity to comment on them. After consideration of the 
public comments, EPA publishes the new or revised factors in AP-42.
[GRAPHIC] [TIFF OMITTED] TP14OC09.000

    As will be discussed in more detail in section IV, we propose to 
move from this subjective resource intensive system where EPA relies on 
a relatively open-ended set of criteria to make major decisions such as 
the test data and factor quality ratings to one that is objective (more 
science based) and designed to reduce the variability associated with 
manual emissions factor development. The new system will provide an 
objective evaluation scheme for grading the quality of each emissions 
test, as well.
    We are in the process of updating and revising three key existing 
tools (WebFIRE, ERT, and the emissions factors guidance document) to 
help us improve the current system. Note that the revised emissions 
factors guidance document will provide information for implementing 
both WebFIRE and ERT. The existing tools are described in the remainder 
of this section. Section IV describes how we plan to augment and update 
these tools to develop the improved emissions factors development 
program.

A. WebFIRE

    WebFIRE, on the EPA Web site at https://cfpub.epa.gov/oarweb/index.cfm?action=fire.main, is the Internet version of the Factor 
Information Retrieval (FIRE) Data System software application (in a 
Microsoft Access format) database. WebFIRE contains EPA's recommended 
emission estimation factors for criteria and hazardous air pollutants 
obtained from AP-42, Locating and Estimating (L&E) documents, and other 
documents. The WebFIRE database usually contains a single value 
(factor) for source classification code (SCC),\2\ control, and 
pollutant combination. Users can conduct simple or detailed searches 
for emissions factors by process, control device, and/or pollutant. 
There is a separate database (https://www.epa.gov/ttn/chief/database/search.html) that is available to access the complete test reports and 
other references cited in the section and background report. Also, for 
many AP-42 sections there is a background report containing summaries 
of the contents of the supporting test reports, assessments of the 
quality of these test reports, judgments on the combining and 
separation of reports for averaging, and the final assessment of the 
quality rating assigned to the final factor. We are modifying WebFIRE 
to connect these three components and provide stakeholders with 
improved access and management capabilities.
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    \2\ There are currently a few emissions factors in AP-42 with 
duplicate values (factors). EPA is working to correct these 
emissions factors so that there are no duplicates.
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B. Electronic Reporting Tool (ERT)

    In order to streamline the collection of source test data and 
ensure the completeness of data collection for the development of 
emissions factors, we created the ERT. The current version of the ERT 
is available at https://www.epa.gov/ttn/chief/ert/ert_tool.html. The 
ERT is a Microsoft Access desktop application that is currently an 
electronic alternative to the submittal of paper test plans, reports, 
and

[[Page 52727]]

evaluations. Currently, data collected using 19 of EPA's emissions 
measurement methods for stationary sources can be handled by the ERT. 
The ERT supplements the time-intensive manual preparation and 
transcription of stationary source emissions test plans and reports for 
emissions sources testing with an electronic alternative where the 
resulting data can be transmitted more easily and quickly to the Agency 
and S/L/Ts who choose to use this system.
    The ERT provides a format and a process that: (1) Documents the key 
information and procedures required by the existing EPA Federal Test 
Methods; (2) facilitates coordination among the source, the test 
contractor, and the regulatory agency in planning and preparing for the 
emissions test; (3) provides for consistent criteria to characterize 
quantitatively the quality of the data collected during the emissions 
test; (4) standardizes the form and content of test reports; and (5) 
calculates the emissions factor, and exports the emissions factor and 
associated data to WebFIRE. We expect the ERT to significantly reduce 
the monitoring and testing burden for testers, source owners or 
operators, S/L/Ts, EPA, and other interested stakeholders in 
collecting, reviewing, storing, and accessing test data and reports.

C. Emissions Factors Development Guidance

    We have developed guidance to assist in the emissions factors 
development process titled, ``Procedures for Preparing Emissions 
Factors'' (EPA-454/R-95-015).\3\ This document is intended for use by 
EPA employees, EPA contractors, and external stakeholders. It describes 
the procedures, technical criteria, and standards and specifications 
for developing and reporting air pollutant emissions factors or 
equations for publication in AP-42. The document also includes 
background on emission factors and their uses and limitations. It 
describes the pollutant terminology used in AP-42 and discusses some of 
the emissions test methods used to measure these pollutants. The 
reasons and procedures for initiating revisions to emissions factors 
are also discussed. In addition, public participation procedures are 
discussed. Many of the changes discussed in the proposed emissions 
factor development process will be reflected in a revised procedures 
document.
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    \3\ We have previously prepared a revised procedures document 
(2006 draft) for public review. Based on the comments we received, 
that document was withdrawn and never finalized.
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IV. Changes to the Emissions Factors Program, Emissions Factors 
Development, and Associated Tools

A. Potential Revisions to the Emissions Factors Development Process: 
Overview and Issues

    As described in this notice, our current plans are to move from the 
relatively static format for emissions factors development to one that 
is more flexible, current, and transparent. We will strive for a 
balanced process that may be more prescriptive in many aspects of the 
program while providing users with the flexibility to derive factors 
that are more suitable for their specific intended purpose. Figure 2 
provides an overview of how this process could work. We believe this 
process can provide source owners or operators with the tools they need 
to develop emissions factors and provide environmental authorities with 
the tools they can use to assess the quality and uncertainty of 
emissions test data. These tools should reduce real or perceived 
barriers to emissions factors development and result in a substantially 
improved emissions factors development process.
[GRAPHIC] [TIFF OMITTED] TP14OC09.001

    Under the proposed system, source test data would be compiled 
electronically via the ERT or another electronic format by the source 
submitting the data. Because the ERT does not yet support all test 
methods and because some users may prefer to use a different format, we 
have provided a spreadsheet template that is to be used to submit 
source test reports that do not use the ERT. See https://www.epa.gov/ttn/chief/ert/ert_tool.html for a copy of

[[Page 52728]]

the current version of the spreadsheet. We are also seeking comment on 
the availability of other electronic formats that currently may be used 
by sources to report source test information to their S/L/Ts and 
whether these formats could be used or adapted to fit into this 
proposed process.
    In general, we believe that standardization of the test report's 
form and content will enhance the emission factor development process, 
while at the same time increase accuracy of the emissions factors. 
Performance test data compiled in the ERT will also provide value to 
the enforcement and compliance monitoring community through the 
readily-available information from the tests in an electronic format. 
The ERT will provide other items of information from stack tests that 
may be used for evaluation that EPA's stationary source compliance 
monitoring/enforcement system, the Air Facility System (AFS), does not 
currently house such as method test used, process being tested, 
emissions levels and stack test review date. However, we recognize that 
such report standardization could have an impact on S/L/T data systems 
and how they electronically store such information. Some sources might 
still be required to submit paper or other reports to satisfy S/L/T 
requirements. We request comment on how the design of the ERT might 
mitigate these concerns.
    We expect that our improved emissions factors' development process, 
including the ERT, will facilitate the submittal of new test data from 
a number of sources. As explained later in this notice, we are 
considering requiring certain facilities to submit electronically their 
performance test data to WebFIRE. In addition, it is possible that 
sources or groups with an interest in adding or revising emissions 
factors for certain categories might be motivated to submit data from 
previous tests or tests conducted for other purposes than complying 
with a Federal standard. To the extent that these data are 
representative of current practices in the category, they could and 
should be considered in emissions factor development.
    We believe that the field evaluations and source test assessments 
performed by S/L/Ts improve the reliability of the test data. For 
example, such assessments will help to ensure testing requirements are 
met, the test plan was followed, and results were accurately recorded 
while also minimizing sample recovery/handling errors and equipment 
errors. We want to encourage this type of third party review of all 
source tests. Ideally the S/L/T would use the tools and criteria we 
provide to conduct this review, but in some cases acceptable reviews 
might be provided by independent contractors or others with an interest 
in developing or revising certain emissions factors. Well conducted and 
documented source tests that have been subject to such review can 
potentially receive a higher quality rating than tests that have not 
been reviewed.
    We seek comment on other ways that we could encourage independent 
``third party'' reviews and the weight we should give them in assigning 
a quality rating. Even in the absence of quality reviews for a test, 
there will be broader quality assurance provisions in the proposed 
process. EPA plans to conduct audits of selected tests to ensure their 
quality as part of the overall program. In addition, we will retain the 
public review and comment features of the existing system to provide 
additional assurance that tests submitted to the system are assigned an 
appropriate quality rating. However, at this time, it is not our intent 
to make this process a formal rulemaking process.
    Under the current performance test evaluation system, test data 
quality is rated A through D, with A-ratings assigned to well 
documented tests performed by using an EPA reference test method, or 
when not applicable, a sound methodology that is well-documented. At 
the other end of the spectrum, a D-rated test is based on test reports 
with minimal documentation or where a generally unacceptable method was 
employed. The test quality is reported in enough detail for adequate 
validation, and raw data are provided that can be used to duplicate the 
emission results presented in the test report. In the absence of better 
test reports, lower-rated tests may provide an order-of-magnitude value 
for a source category emission factor. Specific criteria that are 
considered in assigning the test report quality ratings include source 
operation (e.g., whether the source was conducting the test under 
representative operating conditions), test method and sampling 
procedures, process information (extent to which process variation 
explains variation in test runs), and documentation of the analysis and 
calculations. After assigning a preliminary emission data quality 
rating based on these criteria, the quality of production data is 
considered. Test data that include the collection of production or 
process data during the test are rated at a higher level than tests 
that do not include production data.
    Under the process being considered, the ERT or alternative 
electronic format would be modified to provide a rating for the quality 
of the individual test based on specified algorithms and data quality 
objectives. The very process of using the ERT will address many of the 
rating issues described above by encouraging submittal of the 
information needed for an A rating. We are not seeking comment on 
specific changes to the ERT and associated procedures document. 
However, we are interested in comments on the general features we 
should incorporate to move us to an automated system for compiling test 
data and calculating or assigning corresponding test ratings. We are 
also seeking comments on whether the use of different formats for the 
ratings might be helpful for stakeholders. For example, would a more 
prescriptive numerical test report assessment rating focus more 
attention on the quality of the test reports, thereby improving the 
information in these reports and provide more information to the 
stakeholders on the quality of the data? As described above, should a 
well-documented performance test conducted according to the Federal 
Reference Method that has been reviewed by an independent third party 
receive a rating adjustment to reflect the results of the third party 
verification? Also, we are seeking comment on whether the third party 
reviewer should have the authority to reduce the quality rating of a 
test report (such as noting poor documentation or test performance 
deficiencies).
    Under our conceptual approach, the source test data would be 
transferred from ERT to EPA's Central Data Exchange \4\ (CDX), which is 
the point of entry on the Environmental Information Exchange Network 
(Exchange Network) for environmental data exchanges to the Agency. In 
the future, we may consider using the capabilities of the CDX to 
provide for future exchanges of information in these reports 
electronically with facility, state, or federal data systems. For 
example, as mentioned earlier, it is possible that there might be other 
audiences for the ERT data such as the AFS. This EPA database contains 
compliance monitoring and enforcement data for stationary sources of 
air pollution regulated by EPA and S/L/Ts. The environmental regulatory 
community uses this information to track the compliance status of point 
sources with various programs regulated under the Clean Air Act. With 
certain modifications, the ERT could be designed to collect information 
used by AFS. We believe that by providing stack

[[Page 52729]]

test and facility data electronically through the ERT in a format for 
S/L/Ts to update AFS would result in a decrease of some existing 
reporting requirements' burden for S/L/Ts. We seek comments on whether 
the ERT information should be used to provide input to the AFS (and 
whether this would decrease S/L/T reporting burden). Transfers to other 
data systems such as the National Emissions Inventory, Toxics Release 
Inventory, and Title V reporting also may be desirable. We request 
comments on how and whether the ERT could be expanded to address other 
program needs.
---------------------------------------------------------------------------

    \4\ For more information on the CDX, see https://www.epa.gov/cdx/.
---------------------------------------------------------------------------

    The Cross-Media Electronic Reporting Regulation (CROMERR) \5\ has 
been recently promulgated to provide the legal framework for electronic 
reporting of information and data to EPA and others who administer EPA 
programs. CROMERR is intended to reduce the cost and burden of 
electronic reporting while maintaining the level of corporate, legal, 
and individual responsibility and accountability that exists in the 
traditional paper format. At this time, we intend to develop ERT to 
fully comply with CROMERR.
---------------------------------------------------------------------------

    \5\ For more information on CROMERR, see EPA's Web site at: 
https://www.epa.gov/CROMERR/.
---------------------------------------------------------------------------

    Once received through CDX, the source test data would be stored in 
WebFIRE. We currently plan to update WebFIRE to collate and integrate 
the data into emissions factors calculations for similar processes, 
pollutants, and control devices. For example, our current plan is to 
upgrade WebFIRE to calculate automatically the arithmetic mean of the 
data in individual source test reports to provide updated emissions 
factors on a periodic schedule. Please note that we do not envision 
that this approach would be used to update emissions factors as each 
source test is received. Source test data will not be used for new or 
amended emissions factors until the data have been vetted through our 
public review process. Additional features such as calculations of 
other statistical and distribution characteristics, including the 
standard deviation and range of data values, could also be added. We 
seek comments on what kinds of statistical information would be helpful 
for stakeholders.
    The frequency of emissions factors updates is an issue for which we 
are seeking comment. As noted above, while WebFIRE might theoretically 
be structured to calculate a new or revised emissions factor whenever a 
qualified test is submitted, we understand that updating emissions 
factors very frequently may be disruptive to emissions factors users 
because it could create a rapidly moving target that could add 
significant uncertainty to users. Instead, we think a better approach 
is to schedule periodic updates. Such updates might be based on a 
specified calendar schedule to allow interested parties to understand 
when an update might be expected. Because updating emissions factors 
impacts many other programs, such as operating and new source review 
permitting, modeling, risk and technology analysis, control strategy 
development, enforcement, and others, we believe that updating specific 
emissions factors more than once per year would complicate activities 
of these other programs. Other triggers could be when a certain volume 
of new data is submitted in certain categories, or when the newly 
submitted data results in significant changes to the emissions factor. 
There also might be value in making supplementary updates whenever 
there is an associated review of an existing standard (every 8 to 10 
years). We are seeking comments on the frequency and scheduling of 
emissions factors updates.
    Some stakeholders have expressed concern that new data would be 
used to automatically update emissions factors and that there would be 
no opportunity afforded to comment on the accuracy, representativeness, 
and completeness of the new data. We believe this is a valid concern 
and are planning, as discussed above, to only update emissions factors 
on a periodic schedule. In addition, we are planning on incorporating a 
full public review and comment period into WebFIRE, similar to the 
existing system for updating emissions factors. When all data for a 
specific source category, control device, and pollutant are compiled 
and resultant emissions factors are drafted, we currently notify all 
subscribers to the CHIEF list serve (https://www.epa.gov/ttn/chief/listserv.html) that new draft emissions factors are available for 
public review. We plan to add a feature into WebFIRE that will 
automatically notify subscribers of the availability of new proposed 
emissions factors for review and comment.
    We plan to add flexibility to WebFIRE so that the user may 
calculate their own emissions factor using a different mix of test 
reports than those used for the existing emissions factor. Sources 
already have the ability to suggest alternative factors, but this 
change to WebFIRE could help make the development process more 
transparent. This capability might lessen the need for extremely 
frequent updates and would allow the calculation of emissions factors 
for specific applications for which the average emissions factor is 
inappropriate. However, the resulting ``user calculated'' emissions 
factors would not be considered ``official'' EPA factors and we do not 
plan to retain these emissions factors in WebFIRE.
    We currently plan to build into WebFIRE decision criteria that 
would be used to select the test data to be used in an emissions factor 
update. For example, one of the current decision criteria includes the 
exclusion of C- and D-rated data whenever A- or B-rated test data are 
available. We seek comment on this approach and other criteria we 
should consider. We anticipate that the changes to the data reporting 
system will generally result in higher quality and significantly more 
data than may have been available in the past for developing some 
emissions factors. At what point and under what conditions do we drop 
lower quality data from the emissions factor calculation? If we allow 
the use of lower quality data, how should it be incorporated? For 
example, if we have an existing emissions factor that is based upon 
several ``C'' rated tests and we receive a new high quality performance 
test, should we average together all of the data or only use the most 
recent high quality test? Would a numerical quality rating that would 
allow automated selection criteria be more useful than the current 
letter rating system?
    WebFIRE will be revised to assign an emissions factor quality 
rating based on specified criteria. We presently assign an emissions 
factor rating to indicate the ability of the overall average factor to 
represent a national annual average emissions rate for the source 
category. The emission factor rating is an overall assessment of how 
good a factor is, based on both the quality of the test(s) or 
information that is the source of the factor and on how well the factor 
represents the emission source. Higher ratings are for emission factors 
based on many unbiased observations, or on widely accepted test 
procedures. In the current procedures guidance document, we state as an 
example that an emissions factor based on 20 or more source tests on 
different randomly selected plants would likely be assigned an ``A'' 
rating if all tests are conducted using a single valid federal 
reference measurement method. Likewise, the guidance indicates that a 
single observation based on questionable methods of testing would be 
assigned an ``E'' rating. Should the current EPA approach for WebFIRE 
incorporate more standardized and consistent criteria for

[[Page 52730]]

assigning emissions factor quality ratings? Should the criteria be 
predicated upon an estimated predictive accuracy of the national 
average emissions factor? How should the quality rating of the 
supporting test data be incorporated into the emissions factor quality 
rating?
    As we revise WebFIRE, a key issue will be how it groups emissions 
data into related clusters for which the average emissions factors will 
be developed. What groupings could be performed automatically and which 
ones would require external manual assessment and management? Who 
should be responsible and what additional level of peer review should 
be introduced? Examples of some of the groupings we consider in the 
present system include the source category, process type, 
representativeness of source, emission source, equipment design, 
operating conditions, raw material or fuel characteristics, control 
devices, and test method used. We request comment on the ways we should 
incorporate these groupings into WebFIRE and whether there are 
additional criteria that should be added. For example, what is the best 
way to characterize facilities for emissions factor development 
purposes? Currently we are using SCC and pollutant codes with control 
device type. Is the current characterization system robust enough?
    Once the SCC for the facility is tested, the specific pollutant 
measured, and the control device is determined, the existing procedures 
should guide the developer through a process of grouping the data. One 
type of grouping may result in combining data from several SCCs (for 
example Utility, Industrial, Commercial and Institutional combustion, 
or the four types of Portland Cement Manufacturing processes). Another 
type of grouping could result in data from different types of control 
devices being combined. In the emissions factor development process, 
these characteristics (and others) are evaluated to determine whether 
there is a significant difference in the factors when different SCC 
and/or controls are represented. We traditionally combine data from 
different SCC and controls for some pollutants, if the factors are not 
significantly different. The criteria used to determine whether to 
combine data have varied. Should a more standardized assessment and 
decision criteria be developed? Should these criteria be based upon a 
statistical approach? Would a combination of statistical and non-
statistical approaches be reasonable? If so, when would one approach be 
preferred over the other approach?
    In some cases, a grouping of SCC and control device type has what 
appears to be a bimodal distribution of emissions. When detailed 
information is available in the test reports, these differences could 
be attributed to differences in the raw material, the production 
method, the end product specification, or one or more production or 
control device parameters. What methods should be used to assess and 
address these situations? Should the same assessment approach used to 
cluster data be used? Should there be a more rigorous approach adopted? 
In addressing situations where there are significant differences, how 
should they be addressed? In the past, these situations have been 
addressed through the expansion of the available SCCs. In some cases 
this has led to increased confusion for the user of emissions factors. 
In lieu of expanding the available SCCs, should we develop additional 
criteria in WebFIRE to allow for broader differentiation of the 
emissions factors?
    How do we determine whether a specific source has significantly 
changed such that the existing emissions factor is no longer 
appropriate? There are many examples of significant changes, including 
variance in control device performance over time or process changes 
that alter emissions. We are seeking comment on how to determine 
whether a process change is significant enough to warrant a new or 
revised emissions factor. We are also seeking comment on how to account 
for control device performance in establishing emissions factors.
    Another question is how WebFIRE will assess data collected by non-
EPA reference methods, such as those developed by the California Air 
Resources Board or the American Society for Testing and Materials 
(ASTM). We believe that, in many cases, these ``other'' methods may not 
be significantly different from EPA-reference methods and, as is the 
case of some ASTM methods, can be used as alternatives to EPA reference 
methods or are referenced in some of EPA's reference methods. To the 
extent the method is a close replica of the EPA method, we believe that 
WebFIRE should be able to note the different, but similar, method when 
using its data to develop emissions factors. We currently accept 
performance test data collected from non-EPA reference methods to 
develop or revise emissions factors and we are inclined to continue 
this practice. We are seeking comment on whether the use of methods 
other than EPA-reference methods should be noted when used to develop 
emissions factors. Another similar issue is where multiple methods can 
be employed to test a pollutant. For example, there are several federal 
reference methods for testing particulate matter. The particulate 
matter methods were usually designed for a specific source category or 
process, but now have been used for other sources. One approach we have 
been considering is a cross walk in WebFIRE and/or the ERT to explain 
the differences between the various methods and pollutants being tested 
and when such methods are appropriate. Are there some methods that 
should be excluded from WebFIRE? For example, EPA Method 25A can be 
used to develop a mass emissions factor. However, it does not measure 
all the components of hydrocarbons. We also request comment on how the 
quality rating might be adjusted to account for methods that are less 
easy to compare directly.
    There are issues associated with the process for developing draft 
factors. We request comment on how new test data should be presented 
(prior to WebFIRE calculating the emissions factor), when a commenter 
believes there are errors in the test data. Some stakeholders have 
suggested that we should make all data available as they are submitted 
(for public review and comment), but not to be used to update the 
emissions factors until all available data are compiled and evaluated. 
Should the commenter provide a third party review or update, should the 
test be returned to the facility for correction, or should EPA perform 
the third party review? Should the draft emissions factor be presented 
(along with the new test data) and should the draft factor quality be 
presented? In general, what should be the responsibilities of the 
commenters, EPA, and the tested source? We are also seeking comment on 
whether there should be a specified time for submitting comments? 
Should data be posted to the site when it is submitted or during some 
specified period prior to the update of the emission factor in WebFIRE?
    There are several data handling criteria associated with preparing 
draft emission factors. These criteria are addressed in the current 
procedures document and include data averaging, rounding, outliers, 
detection limits, use of blanks, and format and unit of measure of the 
factor. We are requesting comment on whether any changes or additions 
are needed regarding these criteria as we develop changes to WebFIRE. 
We are especially interested in your comments on how to average

[[Page 52731]]

test data that is below the detection limits of the analyzer. 
Similarly, we currently provide the arithmetic mean as the best measure 
of an emissions factor to provide a tool for estimating emissions where 
there are gaps in emissions inventories. However, other descriptive 
statistics such as median, mode, range, percentiles, and standard 
deviation may also be useful in characterizing emissions for other 
purposes. How the precision of the supporting data is characterized is 
a related issue. In general, we believe that the impact associated with 
the emissions variability between sources will be reduced when we 
obtain improved test reports via the ERT or alternative electronic 
format and as we obtain a larger number of higher quality tests. We 
expect that more high quality data will yield more accurate emissions 
factors. In addition, improved process information will allow for 
developing a process based factor which will improve the predictive 
accuracy of the resulting emissions estimate. We request comment on our 
plans to provide additional information on the precision and accuracy 
of the emissions factors in the new emissions factors development 
process. This additional information would include the median, mode, 
range, and standard deviation of the data set used to develop the 
emissions factor. What methodologies and criteria should be used to 
achieve more and better factors? Should WebFIRE be limited only to 
factors that have documented supporting source test data? Should we 
continue to allow the expansion of emissions factors based upon 
unsupported assessments (i.e., assumed control efficiencies applied to 
average controlled factors to arrive at an uncontrolled factor, and 
then a subsequent assumed control efficiency applied to that 
uncontrolled factor to arrive at a controlled factor)?
    Some stakeholders have requested development of emissions factors 
for uncontrolled processes. It is not surprising that the existing 
emissions factors characterize emissions for controlled processes, 
because these are the emissions sources that typically are subject to 
regulation and required to conduct performance tests to demonstrate 
compliance. However, should a source desire to test uncontrolled 
processes and enter the information into the ERT, we would accept such 
data. A broader issue might be how we could encourage stakeholders to 
provide any data (controlled or uncontrolled) and/or to adopt the use 
of the ERT for reporting of testing programs not required for federal 
regulatory purposes.
    Some industry groups and trade associations independently have 
developed industry-specific emissions factors. In some cases, these 
stakeholders have asked us to include their emissions factors in 
WebFIRE without a critical review of the source testing and resultant 
data. Should these groups choose to submit their data through the ERT 
or an alternative electronic format and result in highly rated tests, 
we believe their data should be considered the same as any other data 
for calculating emissions factors. However, some of these tests may 
involve information that the sources being tested consider proprietary 
or the test reports may lack critical details because they were 
conducted for different purposes. Where do we draw the line in 
accepting such data for use in developing emissions factors? If we 
accept some lesser quality tests and data, would others be encouraged 
to do the same which may result in less transparency in the process and 
poorer quality emissions factors? If CBI data are considered by us, how 
can we assure the other stakeholders of the reliability of the 
supporting data without incurring a workload on ourselves that would 
result in substantial slowing of the process? A similar issue is 
whether we should accept assessment of their source test data by 
stakeholders. We believe one way to address this concern is to have an 
independent third party review. We have discussed third party review to 
ensure objectivity of the data elsewhere in this notice.
    We intend for the revised emissions factors development process 
guidance to retain the opportunity for public review of the individual 
test data, the emissions factor calculations, and associated quality 
rating prior to finalizing any new or revised emissions factor. 
However, as previously discussed our current thinking is to modify some 
of the aspects of the review process. For example, we currently plan to 
change from revising entire sections in AP-42 at one time to a review 
of recently added source test data. We are also considering conducting 
a periodic review of the entire WebFIRE (limited to data that had been 
submitted since the last review) at a single time. We request comment 
on these changes and suggestions for alternative approaches to updating 
emissions factors and handling data before they are used to update 
emissions factors. We also recognize the potential impact that changing 
emissions factors can have on sources (e.g., a higher revised emissions 
factor could mean that the source may be out of compliance, or the 
source may become subject to newly applicable requirements such as 
Title V or Toxics Release Inventory reporting). Should we limit reviews 
to the additional source tests or should we allow reviewers to address 
the implications of these additions? We request comment on any steps 
that could enhance public review of the emissions factor development 
process and outcome and will contribute to the timely development of 
new and revised factors.

B. Test Data Submittal Requirements

    We believe that an additional enhancement to the current emissions 
system is for us to take steps to increase the quality and quantity of 
performance test data submittals. With the ERT, we believe we have a 
tool to encourage the submission of higher quality test data. However, 
the quantity of data submittals has to be increased to ensure 
continuous development of better emissions factors. Unfortunately, 
while the ERT has been available for several years, we are not seeing 
widespread use of it to submit data to EPA for use in emissions factors 
development. There could be several reasons that test data submittals 
to EPA are not more widespread.
     There is no regulatory driver requiring submission of 
data.
     Stakeholders are worried that data submitted this way will 
result in emissions factors being updated too quickly, making the 
verification of appropriate emissions factors a more difficult process.
     The ERT is perceived as requiring too much data or more 
data are required than what is normally required by S/L/Ts for 
performance testing.
     There are electronic compatibility issues for agencies 
with electronic reporting systems that are similar to ERT in scope. 
Some agencies may have their own electronic reporting systems, but 
these may be limited to the reporting of the test results only.
     There is a perception that using the ERT costs more than 
the traditional paper formats or that using the ERT will increase the 
costs of performance testing to collect the information required by the 
ERT.
     Agencies still require paper reports or a signed copy of 
the report.
    In order to ensure we receive timely submittal of data necessary 
for a robust emissions factors program, we are considering using the 
authority under section 114 of the Clean Air Act to require the 
electronic submission to EPA of performance test reports conducted for 
compliance certifications or other regulatory purposes. Specifically, 
we are considering

[[Page 52732]]

amending the reporting provisions of the 40 CFR parts 60 (New Source 
Performance Standards (NSPS)), 61 (National Emission Standards for 
Hazardous Air Pollutants (NESHAP)), and 63 (Maximum Achievable Control 
Technology (MACT standards)) General Provisions to require electronic 
submittal of performance tests that are already required by standards 
in these parts. The General Provisions contain requirements, such as 
monitoring, recordkeeping, and reporting that are common to all NSPS, 
NESHAP, and MACT rules. We want to emphasize that this approach would 
not add any additional performance testing. Nor do we anticipate that 
this requirement would significantly increase the reporting and 
recordkeeping burden of sources that are already required to submit 
their performance test data. As described below, we think that using 
the ERT will likely result in reducing the overall burden of submitting 
test data by standardizing the reporting form and automating many of 
the quality assurance and calculation features associated with paper 
reporting. We are seeking comments on the concept of requiring 
electronic submittal of performance reports. We are also seeking 
comments on any perceived reduction (or other benefits) or addition in 
costs to stakeholders should we require the submittal of performance 
tests required by parts 60, 61, and 63. Should we propose such 
requirements in a future rulemaking, we will assess this potential 
burden reduction.
    We also request comment on whether we should specify specific 
required elements to be contained in source test reports. The 
components would include not only the documentation of the conduct of 
the stack sampling activities, but also the process parameters, such 
as, process operations, control device design, and monitoring 
parameters that are indicative of the emissions performance of the 
process and control device. We believe that requiring these components 
should not increase performance test burdens, because this kind of 
information is required in the existing methods and are necessary to 
evaluate the conformance to the test method or for compliance with 
applicable parts 60, 61, or 63 provisions. The advantage of the ERT, 
which was developed with input from stack testing companies, is that it 
would provide a standardized method and template to collect and store 
all the documentation required.
    We believe that obtaining these test data already collected for 
other purposes and using them in the emissions factors development 
program will save industry, S/L/Ts, and EPA time and money. A benefit 
of submitting these data to WebFIRE electronically is that these data 
will greatly improve the overall quality of the existing and new 
emissions factors by supplementing the pool of emissions tests data 
upon which the emission factor is based and by ensuring that data are 
more representative of current industry operational procedures. 
Submitting these data to EPA will address a common complaint we hear 
from industry and regulators that emissions fact