[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 http://www.regulations.gov.
Publicly available docket materials are available either electronically
through http://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 http://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 http://www.regulations.gov or e-
mail. The http://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 http://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 http://www.epa.gov/epahome/dockets.htm.
Docket: All documents in the docket are listed in the http://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 http://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 http://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 http://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 http://www.epa.gov/ttn/chief/ap42/index.html. 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: http://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 http://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 (http://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 http://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 http://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.
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\4\ For more information on the CDX, see http://www.epa.gov/cdx/.
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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.
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\5\ For more information on CROMERR, see EPA's Web site at:
http://www.epa.gov/CROMERR/index.html.
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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 (http://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 factors are out-dated and/
or not representative of a particular source category. We also believe
that having these data will enable EPA to conduct more effective
residual risk analyses (required under section 112(f) of the Clean Air
Act Amendments of 1990) and periodical technology reviews for parts 60
and 63 NESHAP and MACTs respectively, without requiring industry to
submit additional data. Moreover, as each source category emissions'
factors are populated with more high-quality tests, the accuracy of the
emissions factors will increase. The regulations at 40 CFR parts 60,
61, and 63, the NSPS, NESHAP, and MACTs already have performance test
requirements and, again, this rule would not add additional testing.
However, we will need to revise the reporting requirements for these
rules. One option we are contemplating is to amend the reporting
requirements of the general provisions for 40 CFR parts 60, 61, and 63
to require submittal of required performance testing to EPA. Hundreds
of these performance tests are conducted each year and the resultant
test reports and pertinent data reside in S/L/Ts' filing cabinets. EPA
does not receive these tests routinely, and does not have funding to
travel to the S/L/T offices to copy and/or scan these tests to obtain
the data. Subsequently emissions factors remain static.
We are seeking comment on the scope of required data submittals.
For example, there are some source categories with numerous sources and
frequent testing requirements. In some cases, this might result in
hundreds of submittals for the same category. Should there be a process
to limit the number of reports in these situations? Also, should there
eventually be a cutoff in the submittal requirement after several years
of data have been submitted? Statistic analyses show that data from
more than 30 source tests normally do not appreciably impact the mean
value of the emissions factor. On the other hand, if we limit the
number of source test reports, then how would we determine that there
had been significant changes in processes and/or controls that might
influence the existing emissions factors, suggest the need for new
emissions factors, or the need for new source classification codes?
Requiring submission of performance test data will require
coordination with respect to changes to ERT and WebFIRE. For example,
ERT will need to be updated to accommodate other pollutant measurements
that may be required in 40 CFR parts 60, 61, and 63. The ERT also needs
to be modified to transmit data to a centralized point (EPA's Central
Data Exchange), so that it could be stored in WebFIRE for future use.
We believe that ERT, or an alternate system (such as some existing
S/L/T electronic performance test submittal software), should be the
preferred method of submitting test data that ensures the quality of
the data that are used in emissions factors development. In addition to
providing an easy way to submit performance tests and more consistency
in these submissions, the ERT addresses some source test reporting
deficiencies we have observed over the years. For example, not all
source tests received from S/L/Ts include the documentation necessary
to verify that the procedures established in the applicable test method
are being performed. Test reports also may fail to include reports and
the requisite documentation from laboratories describing the analyses
performed.
Documentation is sometimes lacking regarding the facility's
production level, process flow rate, secondary products, final
products, or other integral information. Information regarding the
facility's performance, i.e. at normal or near maximum production
levels at the time of testing, may also be needed. Critical design and
operational information on the equipment used to control the pollutants
being tested also may be missing. Given our objective to improve the
quality of data used to develop emissions factors, we think this
detailed information may be needed. The absence of any of this
information will be considered in rating the quality of the performance
test data.
In summary, we request comment on whether additional source and
testing information should be required to be submitted to the ERT to
enhance the emissions factor development process. To what extent should
background information, like a process flow data, on the source be
required to be provided? Finally, additional data may be needed to
develop algorithms (based on emissions factors), such as those used in
[[Page 52733]]
the TANKS \6\ program. In cases where we seek information on process
conditions, we may find that a few sources may consider this
information or data to be CBI. There are several issues with requiring
CBI, and we are seeking comment on the receipt of CBI to develop more
accurate emissions factors.
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\6\ TANKS is a Windows-based computer software program that
estimates volatile organic compound (VOC) and hazardous air
pollutant (HAP) emissions from fixed- and floating-roof storage
tanks. TANKS is based on the emission estimation procedures from
Chapter 7 of AP-42.
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C. Emissions Factors Content and Format
The existing AP-42 currently expresses emissions factors as the
arithmetic mean, which generally is an expeditious choice for use in
traditional applications such as emissions inventories gap filling.
However, our current thinking is to identify ways to expand the scope
of emissions factors' application into areas where the existing format
of the factors may not satisfy the new application. For example, it may
be helpful to provide the range of the test data to users, so that they
can understand the variability of the source tests used to develop a
particular emissions factor. Also, WebFIRE could be modified to
calculate and provide other relevant statistical and distribution
characteristics, including the standard deviation, in order to provide
users with a more complete description of the data. Such a description,
whether tabular or graphical, could help educate users and allow them
to make better informed decisions. We seek comment on the type and
format of emission factor information beyond the mean value that would
be useful for stakeholders.
D. Interacting With the SPECIATE Database
SPECIATE is the EPA repository of total organic compound (TOC) and
particulate matter (PM) speciation profiles for emissions from
stationary and mobile air pollution sources. The profiles are key
inputs to air quality modeling and source-receptor modeling
applications. SPECIATE essentially provides emissions factors and
information for pollutants, from both controlled and uncontrolled
processes, at a level of detail that is not adequately or traditionally
presented in AP-42. The emissions factors developed for SPECIATE are
gleaned from available sources, such as test data, literature searches
or academic studies. References and data quality ratings are provided
to guide the user. We are seeking comment on whether SPECIATE (or any
other source of emissions factors) should be linked to or contained in
WebFIRE.
V. Request for Comment and Next Steps
As described throughout this notice, EPA is soliciting comments to
help in improving the way emissions factors are developed and used. We
also encourage readers to submit other general comments and supporting
data that could help us further improve the emissions factors program.
In order to ensure a well balanced response and develop the best
possible product, we encourage the submittal of both comments offering
suggestions and changes and those supporting our current thinking on
potential emissions factors program improvements.
For the convenience of the reader, the following list summarizes
the major areas for which we are seeking comment:
Is it appropriate to amend the reporting provisions of the
40 CFR parts 60, 61, and 63 General Provisions to require electronic
submittal of performance tests that are already required by standards
in these parts?
As acknowledged earlier, emissions factors are used for
many air pollution control activities that were not envisioned when
this program was established. We are seeking comment on the
appropriateness of using emissions factors for these other purposes
and, if they are to be used for other purposes, should there be any
other requirements for these emissions factors (such as using only high
rated emissions factors for permitting) or more information required
for these emissions factors (such as greater precision and accuracy).
Are third party reviews of performance tests needed and,
if so, then how could we encourage third party reviews of test reports
and what weight should we give reviews in assigning a quality rating?
Should we require electronic submittal of performance
tests via the ERT or some similar electronic submittal software (such
as existing S/L/T submittal software)? What is the availability of
other electronic formats that currently may be used by sources to
report source test information to their S/L/Ts? Could these formats be
used or adapted to fit into our proposed process?
Would a different format for the ratings of test data be
useful? For example, would a numerical system provide more information
on the quality of the test rating?
If needed, should additional information be required as
part of ERT to enhance the emissions factors development process?
Should we obtain continuous emissions monitoring data in a fashion that
could be used for emissions factors development in the next versions of
ERT and WebFIRE?
We plan to build into WebFIRE decision criteria that would
be used to select the test data to be used in an emissions factors
update. For example, we may have four performance tests conducted in
1979 and four performance tests conducted in 1995 where the source made
a slightly different product. What tests should we use to develop the
emissions factors and what criteria should we consider to select the
performance tests?
How should emissions data be grouped into related clusters
for which the average emissions factors will be developed? Examples of
some of the criteria 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.
How should WebFIRE assess data collected by non-EPA
reference methods (such as those developed by the California Air
Resources Board) or data from two different methods that are averaged
to develop an emissions factor? How might the quality rating be
adjusted to account for methods that are less easy to compare directly?
At what frequency or schedule should emissions factors in
WebFIRE be updated?
There are several data handling criteria associated with
preparing draft emission factors. These criteria include data
averaging, rounding, outliers, detection limits, use of blanks, and
format and unit of measure of the factor. How should we account for
these potential variables in emissions factors?
Besides calculating the arithmetic mean to be used as the
traditional emissions factor, what other statistical characteristics
should additional features such as calculations of median and mode
factors or other information from the data sets also be provided and in
what format, i.e., tabular or graphical, should they be provided?
Should there be a process to limit the number of
performance test reports from a particular source category submitted to
EPA? For example, should we establish a threshold in the submittal
requirement after 50 or 100 performance tests have been submitted? If
so, then how would EPA know when source categories significantly change
process or controls, such that we would want
[[Page 52734]]
additional performance tests for emissions factors revisions?
What steps could enhance public review of the emissions
factors development process and outcome and contribute to the timely
development of new and revised factors?
When finalized, the Emissions Factors Guidance will address many of
these issues.
We will consider the comments submitted in response to this ANPRM
as we proceed to implement an improved emissions factors program.
VI. Statutory and Executive Order Reviews
Executive Order 12866: Regulatory Planning and Review
Under Executive Order 12866, entitled Regulatory Planning and
Review (58 FR 51735, October 4, 1993), this is a ``significant
regulatory action'' because we expect this action to raise novel legal
or policy issues. Accordingly, EPA submitted this action to the Office
of Management and Budget (OMB) for review under Executive Order 12866
and any changes made in response to OMB recommendations have been
documented in the docket for this action. Because this action does not
propose or impose any requirements, and instead seeks comments and
suggestions for the Agency to consider in possibly developing a
subsequent proposed rule, the various statutes and Executive Orders
that normally apply to rulemaking do not apply in this case. Should EPA
subsequently determine to pursue a rulemaking, EPA will address the
statutes and Executive Orders as applicable to that rulemaking.
List of Subjects in 40 CFR Parts 60, 61, and 63
Environmental protection, Air pollution control, Hazardous
substances, Reporting and recordkeeping requirements, Emissions
factors, Performance testing.
Dated: October 7, 2009.
Lisa P. Jackson,
Administrator.
[FR Doc. E9-24684 Filed 10-13-09; 8:45 am]
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