Federal Register / Vol. 74, No. 197 / Wednesday, October 14, 2009 / Proposed Rules 52723 

application of those requirements would 

be inconsistent with the CAA; and 

• Does not provide EPA with the 

discretionary authority to address, as 

appropriate, disproportionate human 

health or environmental effects, using 

practicable and legally permissible 

methods, under Executive Order 12898 

(59 FR 7629, February 16, 1994). 

In addition, this rule does not have 

tribal implications as specified by 

Executive Order 13175 (65 FR 67249, 

November 9, 2000), because the SIP is 

not approved to apply in Indian country 

located in the state, and EPA notes that 

it will not impose substantial direct 

costs on tribal governments or preempt 

tribal law. 

List of Subjects 

40 CFR Part 52 

Environmental protection, Air 

pollution control, Electric utilities, 

Intergovernmental relations, 

Incorporation by reference, Carbon 

monoxide, Nitrogen oxides, Ozone, 

Particulate matter, Reporting and 

recordkeeping requirements, Sulfur 

dioxide. 

40 CFR Part 97 

Environmental protection, Air 

pollution control, Electric utilities, 

Intergovernmental relations, 

Incorporation by reference, Nitrogen 

oxides, Ozone, Particulate matter, 

Reporting and recordkeeping 

requirements, Sulfur dioxide. 

Dated: October 5, 2009. 

Beverly H. Banister, 

Acting Regional Administrator, Region 4. 

[FR Doc. E9–24705 Filed 10–13–09; 8:45 am] 

BILLING CODE 6560–50–P 

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. 

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 


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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 sitespecific 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 wellaccepted 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 longterm 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, lowcost 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 


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1A 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. 

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. 

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, onetime 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 multipart 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 


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2There 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. 

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. 

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. 

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 


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3We 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. 

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. 

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. 

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 


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4For more information on the CDX, see http:// 

www.epa.gov/cdx/. 

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 welldocumented. 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 


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5For more information on CROMERR, see EPA’s 

Web site at: http://www.epa.gov/CROMERR/ 

index.html. 

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. 

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. 

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 


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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 EPAreference 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 


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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 


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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 


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Federal Register / Vol. 74, No. 197 / Wednesday, October 14, 2009 / Proposed Rules 52733 

6TANKS 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. 

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. 

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 


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52734 Federal Register / Vol. 74, No. 197 / Wednesday, October 14, 2009 / Proposed Rules 

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] 

BILLING CODE 6560–50–P 


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