Methods for Measurement of Filterable PM10, 12970-13012 [E9-6178]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 74, Number 56 (Wednesday, March 25, 2009)]
[Proposed Rules]
[Pages 12970-13012]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E9-6178]



[[Page 12969]]

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Part III





Environmental Protection Agency





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40 CFR Part 51



Methods for Measurement of Filterable PM10 and 
PM2.5 and Measurement of Condensable Particulate Matter 
Emissions from Stationary Sources; Proposed Rule

Federal Register / Vol. 74, No. 56 / Wednesday, March 25, 2009 / 
Proposed Rules

[[Page 12970]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 51

[EPA-HQ-OAR-2008-0348; FRL-8784-5]
RIN 2060-AO58


Methods for Measurement of Filterable PM10 and 
PM2.5 and Measurement of Condensable Particulate Matter 
Emissions From Stationary Sources

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: This action proposes amendments to Methods 201A and 202. The 
proposed amendments to Method 201A would add a particle-sizing device 
to allow for sampling of particulate matter (PM) with mean aerodynamic 
diameters less than or equal to 2.5 micrometers ([mu]m) 
(PM2.5 or fine PM). The proposed amendments to Method 202 
would revise the sample collection and recovery procedures of the 
method to reduce the formation of reaction artifacts that could lead to 
inaccurate measurements of condensable particulate matter (CPM). 
Additionally, the proposed amendments to Method 202 would eliminate 
most of the hardware and analytical options in the existing method, 
thereby increasing the precision of the method and improving the 
consistency in the measurements obtained between source tests performed 
under different regulatory authorities. Finally, in this notice we are 
soliciting comments on whether to end the transition period for CPM in 
the New Source Review (NSR) program on a date earlier than the current 
end date of January 1, 2011. The proposed amendments would improve the 
measurement of fine particulates and would help State and local 
agencies in implementing CPM control measures to attain the 
PM2.5 National Ambient Air Quality Standards (NAAQS) which 
were established to protect public health and welfare.

DATES: Comments. Comments must be received on or before May 26, 2009.

ADDRESSES: Submit your comments, identified by Docket ID Number EPA-HQ-
OAR-2008-0348, by one of the following methods:
     https://www.regulations.gov. Follow the on-line 
instructions for submitting comments.
     E-mail: Send your comments via electronic mail to a-and-r-docket@epa.gov.
     Fax: (202) 566-9744.
     Mail: Methods for Measurement of Filterable 
PM10 and PM2.5 and Measurement of Condensable 
Particulate Matter Emissions from Stationary Sources, Environmental 
Protection Agency, Mailcode 2822T, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460. Please include a total of two copies.
     Hand Delivery: EPA Docket Center EPA Headquarter Library, 
Room 3334, EPA West Building, 1301 Constitution Ave., NW., Washington, 
DC, 20460. Such deliveries are accepted only during the Docket's normal 
hours of operation, and special arrangements should be made for 
deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2008-0348. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
https://www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through https://www.regulations.gov or e-mail. The https://www.regulation.gov Web site 
is an ``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA without 
going through https://www.regulations.gov, your e-mail address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional information about EPA's public 
docket, visit the EPA Docket Center homepage at https://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the https://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g. , CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in https://www.regulations.gov or in hard copy at the Methods for 
Measurement of Filterable PM10 and PM2.5 and 
Measurement of Condensable Particulate Matter Emissions from Stationary 
Sources Docket, EPA/DC, EPA West Building, Room 3334, 1301 Constitution 
Ave., NW., Washington, DC. The Public Reading Room/Docket Center 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 Center is 
(202) 566-1742.
    Public Hearing: If anyone contacts EPA requesting to speak at a 
public hearing concerning our proposal to revise the PM test methods by 
April 14, 2009, we will hold a public hearing on or about April 24, 
2009. Persons interested in presenting oral testimony should contact 
Ms. Kristal Mozingo, Measurement Policy Group (D243-05), Sector 
Policies and Programs Division, EPA, Research Triangle Park, NC 27711, 
telephone number: (919) 541-9767, e-mail address: 
mozingo.kristal@epa.gov. Persons interested in attending the public 
hearing should also call Ms. Mozingo to verify the time, date, and 
location of the hearing. A public hearing will provide interested 
parties the opportunity to present data, views, or arguments concerning 
the proposed test method revisions.
    If a public hearing is held, it will be held at 10 a.m. at the 
Conference Facilities at EPA's Main Campus, Research Triangle Park, NC, 
or an alternate site nearby.

FOR FURTHER INFORMATION CONTACT: For general information, contact Ms. 
Candace Sorrell, U.S. EPA, Office of Air Quality Planning and 
Standards, Air Quality Assessment Division, Measurement Technology 
Group (E143-02), Research Triangle Park, NC 27711; telephone number: 
(919) 541-1064; fax number; (919) 541-0516; e-mail address: 
sorrell.candace@epa.gov. For technical questions, contact Mr. Ron 
Myers, U.S. EPA, Office of Air Quality Planning and Standards, Sector 
Policies and Programs Division, Measurement Policy Group (D243-05), 
Research Triangle Park, NC 27711; telephone number: (919) 541-5407; fax 
number: (919) 541-1039; e-mail address: myers.ron@epa.gov.

SUPPLEMENTARY INFORMATION:

[[Page 12971]]

I. General Information

A. Does This Action Apply to Me?

    This action would apply to you if you operate a stationary source 
that is subject to applicable requirements for total PM or total 
PM10 where EPA Method 202 is incorporated as a component of 
the applicable compliance method.
    In addition, this action would apply to you if Federal, State, or 
local agencies take certain additional independent actions. For 
example, this action would apply to sources through actions by State 
and local agencies which implement CPM control measures to attain the 
PM2.5 NAAQS and specify the use of this test method to 
demonstrate compliance with the control measure. Actions that State and 
local agencies would have to implement include: (1) Adopting this 
method in rules or permits (either by incorporation by reference or by 
duplicating the method in its entirety), and (2) promulgating an 
emissions limit requiring the use of this method (or an incorporated 
method based upon this method). This action would also apply to 
stationary sources that are required to meet new applicable CPM 
requirements established through Federal or State permits or rules, 
such as New Source Performance Standards and New Source Review, which 
specify the use of this test method to demonstrate compliance with the 
control measure.
    The source categories and entities potentially affected include, 
but are not limited to, the following:

------------------------------------------------------------------------
                                                          Examples of
            Category              SIC \1\  NAICS \2\      potentially
                                    code      code    regulated entities
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Industry........................     3569     332410  Fossil fuel steam
                                                       generators.
                                     3569     332410  Industrial,
                                                       commercial,
                                                       institutional
                                                       steam generating
                                                       units.
                                     3569     332410  Electricity
                                                       generating units.
                                     2911     324110  Petroleum
                                                       refineries.
                                     4953     562213  Municipal waste
                                                       combustors.
                                     2621     322110  Pulp and paper
                                                       mills.
                                     2819     325188  Sulfuric acid
                                                       plants.
                                     3241     327310  Portland Cement
                                                       Plants.
                                     3274     327410  Lime Manufacturing
                                                       Plants.
                                     1222     211111  Coal Preparation
                                                       Plants.
                                     1231     212111
                                              212112
                                              212113
                                     3334     331312  Primary and
                                                       Secondary
                                                       Aluminum Plants.
                                     3341     331314
                                     3312     331111  Iron and Steel
                                                       Plants.
                                     3325     331513
                                     2493     321219  Plywood and
                                                       Reconstituted
                                                       Products Plants.
                                     2435     321211
                                     2436     321212
------------------------------------------------------------------------
\1\ Standard Industrial Classification.
\2\ North American Industrial Classification System.

B. What Should I Consider as I Prepare My Comments for EPA?

    Do not submit information containing CBI to EPA through https://www.regulations.gov or e-mail. Send or deliver information identified 
as CBI only to the following address: Roberto Morales, OAQPS Document 
Control Officer (C404-02), U.S. EPA, Office of Air Quality Planning and 
Standards, Research Triangle Park, NC 27711, Attention Docket ID No. 
EPA-HQ-OAR-2008-0348. Clearly mark the part or all of the information 
that you claim to be CBI. For CBI information on 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 Obtain a Copy of This Action and Other Related 
Information?

    In addition to being available in the docket, an electronic copy of 
today's proposed amendments is also available on the Worldwide Web 
(https://www.epa.gov/ttn/) through the Technology Transfer Network 
(TTN). Following the Administrator's signature, a copy of the proposed 
amendment will be posted on the TTN's policy and guidance page for 
newly proposed or promulgated rules at https://www.epa.gov/ttn/oarpg. 
The TTN provides information and technology exchange in various areas 
of air pollution control.

D. How Is This Document Organized?

    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 Obtain a Copy of This Action and Other Related 
Information?
D. How Is This Document Organized?
II. Background
    A. Why Is EPA Issuing This Proposed Rule?
    B. Particulate Matter National Ambient Air Quality Standards
    C. Measuring PM Emissions
    1. Method 201A
    2. Method 202
III. This Action
    A. What Are the Proposed Amendments to Method 201A?
    B. What Are the Proposed Amendments to Method 202?
    C. How Will the Proposed Amendments to Methods 201A and 202 
Affect Existing Emission Inventories, Emission Standards, and Permit 
Programs?
    D. Request for Comments
    1. Items Associated With Both Test Methods
    2. Items Associated With Method 201A
    2. Items Associated With Method 202
IV. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism

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    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations

II. Background

A. Why Is EPA Issuing This Proposed Rule?

    On April 25, 2007 (70 FR 20586), we promulgated the Clean Air Fine 
Particle Implementation Rule regarding the Clean Air Act (CAA) 
requirements for State and Tribal plans to implement the 1997 PM2.5 
NAAQS. These rules require that each State having a PM2.5 nonattainment 
area must submit, by April 5, 2008, an attainment demonstration and 
adopt regulations to ensure the area will attain the standards as 
expeditiously as practicable, but even those areas for which the 
Administrator determines an extension from the 2010 attainment date is 
appropriate may not receive an extension later than a 2015 attainment 
date. The emissions inventories and analyses used in the attainment 
demonstrations must consider filterable and condensable fractions of 
PM2.5 emissions from stationary sources that are significant 
contributors of direct PM2.5 emissions. Direct PM2.5 emissions means 
the solid particles or liquid droplets emitted directly from an air 
emissions source or activity, or the gaseous emissions or liquid 
droplets from an air emissions source or activity that condense to form 
PM or liquid droplets at ambient temperatures.
    The preamble to the April 25, 2007, rule acknowledged that there 
remain questions whether the available test methods provide the most 
accurate representation of primary PM emissions even though some States 
have established emissions limits for CPM. As a result, the final rule 
established a transitional period for developing emissions limits and 
regulations for condensable PM2.5. During this transitional period, EPA 
has committed to devote resources to assessing and improving the 
available test methods for CPM.
    In response to this commitment and to address the need for improved 
measurement of fine PM, EPA is proposing amendments to the following 
test methods in 40 CFR Part 51, Appendix M (Recommended Test Methods 
for State Implementation Plans (SIPs)):
     Method 201A--Determination of PM10 Emissions (Constant 
Sampling Rate Procedure), and
     Method 202--Determination of Condensable Particulate 
Emissions from Stationary Sources.
    These amendments to Method 201A add a particle-sizing device to 
allow for sampling of PM2.5, PM10, or both PM10 and PM2.5. With regard 
to Method 202, we are aware that the method and the various hardware 
and analytic options described therein are sometimes applied 
inappropriately, which can lead to inaccurate and imprecise CPM 
measurements. We are also aware that Method 202 can produce inaccurate 
CPM measurements when sampling certain types of emissions sources, due 
to formation of reaction artifacts. The amendments to Method 202 revise 
the sample collection and recovery procedures of the method to provide 
for more accurate and precise measurement of CPM.

B. Particulate Matter National Ambient Air Quality Standards

    Section 108 and 109 of the CAA govern the establishment and 
revision of the NAAQS. Section 108 (42 U.S.C. 7408) directs the 
Administrator to identify and list ``air pollutants'' that ``in his 
judgment, may reasonably be anticipated to endanger public health and 
welfare'' and whose ``presence * * * in the ambient air results from 
numerous or diverse mobile or stationary sources'' and to issue air 
quality criteria for those that are listed. Air quality criteria are 
intended to ``accurately reflect the latest scientific knowledge useful 
in indicating the kind and extent of identifiable effects on public 
health or welfare which may be expected from the presence of [a] 
pollutant in ambient air* * *.'' Section 109 (42 U.S.C. 7409) directs 
the Administrator to propose and promulgate primary and secondary NAAQS 
for pollutants listed under section 108 to protect public health and 
welfare, respectively. Section 109 also requires review of the NAAQS at 
5-year intervals and that an independent scientific review committee 
``shall complete a review of the criteria * * * and the national 
primary and secondary ambient air quality standards * * * and shall 
recommend to the Administrator any new * * * standards and revisions of 
existing criteria and standards as may be appropriate * * *.'' Since 
the early 1980s, this independent review function has been performed by 
the Clean Air Scientific Advisory Committee (CASAC).
    Initially EPA established the NAAQS for PM on April 30, 1971 (36 FR 
8186) based on the original criteria document (Department of Health, 
Education, and Welfare, 1969). The reference method specified for 
determining attainment of the original standards was the high-volume 
sampler, which collects PM up to a nominal size of 25 to 45 [mu]m 
(referred to as total suspended particulates or TSP). On October 2, 
1979 (44 FR 56730), EPA announced the first periodic review of the air 
quality criteria and NAAQS for PM, and significant revisions to the 
original standards were promulgated on July 1, 1987 (52 FR 24634). In 
that decision, EPA changed the indicator for particles from TSP to 
PM10. When that rule was challenged, the court upheld revised standards 
in all respects. Natural Resources Defense Council v. Administrator, 
902 F. 2d 962 (D.C. Cir. 1990, cert. denied, 498 U.S. 1082 (1991)).
    In April 1994, EPA announced its plans for the second periodic 
review of the air quality criteria and NAAQS for PM, and the Agency 
promulgated significant revisions to the NAAQS on July 18, 1997 (62 FR 
38652). In that decision, EPA revised the PM NAAQS in several respects. 
While EPA determined that the PM NAAQS should continue to focus on 
particles less than or equal to 10 [mu]m in diameter (PM10), EPA also 
determined that the fine and coarse fractions of PM10 should be 
considered separately. The EPA added new standards, using PM2.5 as the 
indicator for fine particles (with PM2.5 referring to particles with a 
nominal mean aerodynamic diameter less than or equal to 2.5 [mu]m), and 
using PM10 as the indicator for purposes of regulating the coarse 
fraction of PM10.
    Following promulgation of the 1997 PM NAAQS, petitions for review 
were filed by a large number of parties, addressing a broad range of 
issues. In May 1999, a three-judge panel of the U.S. Court of Appeals 
for the District of Columbia Circuit issued an initial decision that 
upheld EPA's decision to establish fine particle standards. American 
Trucking Associations v. EPA, 175 F.3d 1027, 1055 (D.C. Cir. 1999), 
reversed in part on other grounds in Whitman v. American Trucking 
Associations, 531 U.S. 457 (2001). The Panel also found ``ample 
support'' for EPA's decision to regulate coarse particle pollution but 
vacated the 1997 PM10 standards, concluding that EPA had not provided a 
reasonable explanation justifying use of PM10 as an indicator for 
coarse particles. Id. at 1054-55. Pursuant to the court's

[[Page 12973]]

decision, EPA removed the vacated 1997 PM10 standards but retained the 
pre-existing 1987 PM10 standards (65 FR 80776, December 22, 2000).
    On October 23, 1997, EPA published its plans for the third periodic 
review of the air quality criteria and NAAQS for PM (62 FR 55201), 
including the 1997 PM2.5 standards and the 1987 PM10 standards. On 
October 17, 2006, EPA issued its final decisions to revise the primary 
and secondary NAAQS for PM to provide increased protection of public 
health and welfare, respectively (71 FR 61144). With regard to the 
primary and secondary standards for fine particles, EPA revised the 
level of the 24-hour PM2.5 standard to 35 [mu]g per cubic meter ([mu]g/
m\3\), retained the level of the annual PM2.5 annual standard at 15 
[mu]g/m\3\, and revised the form of the annual PM2.5 standard by 
narrowing the constraints on the optional use of spatial averaging. 
With regard to the primary and secondary standards for PM10, EPA 
retained the 24-hour PM10 standard (150 [mu]g/m\3\) and revoked the 
annual standard because available evidence generally did not suggest a 
link between long-term exposure to current ambient levels of coarse 
particles and health or welfare effects.

C. Measuring PM Emissions

    Section 110 of the CAA, as amended (42 U.S.C. 7410), requires that 
State and local air pollution control agencies develop and submit plans 
for EPA approval that provide for the attainment, maintenance, and 
enforcement of the NAAQS in each air quality control region (or portion 
thereof) within such State. These plans are known as SIPs. 40 CFR part 
51 (Requirements for Preparation, Adoption, and Submittal of 
Implementation Plans) specifies the requirements for SIPs. Appendix A 
to subpart A of 40 CFR part 51, defines primary PM10 and PM2.5 as 
including both the filterable and condensable fractions of PM. 
Filterable PM consists of those particles that are directly emitted by 
a source as a solid or liquid at the stack (or similar release 
conditions) and captured on the filter of a stack test train. 
Condensable PM is the material that is in vapor phase at stack 
conditions but which condenses and/or reacts upon cooling and dilution 
in the ambient air to form solid or liquid PM immediately after 
discharge from the stack.
    Promulgation of the 1987 NAAQS created the need for methods to 
quantify PM10 emissions from stationary sources. In response, EPA 
developed and promulgated the following test methods:
     Method 201A--Determination of PM10 Emissions (Constant 
Sampling Rate Procedure), and
     Method 202--Determination of Condensable Particulate 
Emissions from Stationary Sources.
1. Method 201A
    On April 17, 1990 (56 FR 65433), EPA promulgated Method 201A in 
Appendix M of 40 CFR Part 51 to provide a test method for measuring 
filterable PM10 emissions from stationary sources. In EPA Method 201A, 
a gas sample is extracted at a constant flow rate through an in-stack 
sizing device which directs particles with aerodynamic diameters less 
than or equal to 10 [mu]m to a filter. The particulate mass collected 
on the filter is determined gravimetrically after removal of uncombined 
water. With the exception of the PM10-sizing device, the current Method 
201A sampling train is the same as the sampling train used for EPA 
Method 17 of Appendix A-3 to 40 CFR Part 60.
    Method 201A cannot be used to measure emissions from stacks that 
have entrained moisture droplets (e.g., from a wet scrubber stack) 
since these stacks may have water droplets that are larger than the cut 
size of the PM10-sizing device. The presence of moisture would prevent 
an accurate measurement of total PM10 since any PM10 dissolved in 
larger water droplets would not be collected by the sizing device and 
would consequently be excluded in determining the total PM10 mass. To 
measure PM10 in stacks where water droplets are known to exist, EPA's 
Technical Information Document (TID) 09 (Methods 201 and 201A in 
Presence of Water Droplets), recommends use of Method 5 of Appendix A-3 
to 40 CFR Part 60 (or a comparable method) and consideration of the 
total particulate catch as PM10 emissions.
    Method 201A is also not applicable for stacks with small diameters 
(i.e., 18 inches or less). The presence of the in-stack nozzle/cyclones 
and filter assembly in a small duct will cause significant cross-
sectional area interference and blockage leading to incorrect flow 
calculation and particle size separation. Additionally, the type of 
metal used to construct the Method 201A cyclone may limit the 
applicability of the method when sampling at high stack temperatures 
(e.g., stainless steel cyclones are reported to gall and seize at 
temperatures greater than 260 [deg]C).
2. Method 202
    On December 17, 1991 (56 FR 65433), EPA promulgated Method 202 in 
Appendix M of 40 CFR Part 51 to provide a test method for measuring CPM 
from stationary sources. Method 202 uses water-filled impingers to 
cool, condense, and collect materials that are vaporous at stack 
conditions and become solid or liquid PM at ambient air temperatures. 
Method 202, as promulgated, contains several optional procedures that 
were intended to accommodate the various test methods used by State and 
local regulatory entities at the time Method 202 was being developed.
    When conducted consistently and carefully, Method 202 provides 
acceptable precision for most emission sources, and the method has been 
used successfully in regulatory programs where the emission limits and 
compliance demonstrations are established based on a consistent 
application of Method 202 and its associated options. However, when the 
same emission source is tested using different combinations of the 
optional procedures, there may appear to be large variations in the 
measured CPM emissions. Additionally, during validation of the 
promulgated method, we determined that sulfur dioxide (SO2) gas (a 
typical component of emissions from several types of stationary 
sources) can be absorbed partially in the impinger solutions and can 
react chemically to form sulfuric acid. This sulfuric acid ``artifact'' 
is not related to the primary emission of CPM from the source but may 
be counted erroneously as CPM when using Method 202. As we have 
maintained consistently, the artifact formation can be reduced by at 
least 90 percent if a one-hour nitrogen purge of the impinger water is 
used to remove SO2 before it can form sulfuric acid (this is 
our preferred application of the Method 202 optional procedures). 
Inappropriate use (or omission) of the preferred or optional procedures 
in Method 202 can increase the potential for artifact formation.
    Considering the potential for variations in measured CPM emissions, 
we believe that further verification and refinement of Method 202 is 
appropriate to minimize the potential for artifact formation. We have 
performed several studies to assess artifact formation when using 
Method 202. The results of our 1998 laboratory study and field 
evaluation commissioned to evaluate the impinger approach can be found 
in ``Laboratory and Field Evaluation of the EPA Method 5 Impinger Catch 
for Measuring Condensible Matter from Stationary Sources'' at the 
following Internet address: https://www.epa.gov/ttn/emc/methods/m202doc1.pdf. Essentially, the 1998 study verified the need for a 
nitrogen purge when SO2 is

[[Page 12974]]

present in stack gas and also provided guidance for analyzing the 
collected samples. In 2005, an EPA contractor conducted a second study 
(``Laboratory Evaluation of Method 202 to Determine Fate of 
SO2 in Impinger Water'') that replicated some of the earlier 
EPA work and addressed some additional issues. The report of that work 
is available at the following Internet address: https://www.epa.gov/ttn/emc/methods/m202doc2.pdf. This report also verified the need for a 
nitrogen purge and identified the primary factors that affect artifact 
formation.
    Also in 2005, a private testing contractor presented a possible 
minor modification to Method 202 at the Air and Waste Management 
Association (AWMA) specialty conference. The proposed modification, 
described in their presentation titled ``Optimized Method 202 Sampling 
Train to Minimize the Biases Associated with Method 202 Measurement of 
Condensable Particulate Matter Emissions,'' involved the elimination of 
water from the first impingers. The presentation (which is available at 
the following Internet address: https://www.epa.gov/ttn/emc/methods/m202doc3.pdf) concluded that modification of the promulgated method to 
use dry impingers resulted in a significant additional reduction in the 
sulfate artifact.
    In 2006, we began to conduct laboratory studies, in collaboration 
with several stakeholders, to characterize the artifact formation and 
other uncertainties associated with conducting Method 202 and to 
identify procedures that would minimize uncertainties when using Method 
202. Since August 2006, we have held two workshops in Research Triangle 
Park, North Carolina. These meetings were held to present and seek 
comments on our plan for evaluating potential modifications to Method 
202 that would reduce artifact formation. Also, these meetings were 
held to discuss our progress in characterizing the performance of the 
modified method, issues that require additional investigation, the 
results of our laboratory studies, and our commitments to extend the 
investigation through stakeholders external to EPA. We held another 
meeting with experienced stack testers and vendors of emissions 
monitoring equipment to discuss hardware issues associated with 
modifications of the sampling equipment and the glassware for the 
proposed CPM test method. Summaries of the method evaluations, as well 
as meeting minutes from our workshops, can be found at the following 
Internet address: https://www.epa.gov/ttn/emc/methods/method202.html.
    The laboratory studies that were performed fulfill a commitment in 
the preamble to the Clean Air Fine Particle Implementation Rule (72 FR 
20586, April 25, 2007) to examine the relationship between several 
critical CPM sampling and analysis parameters and, to the extent 
necessary, propose revisions to incorporate improvements in the method. 
While these improvements in the stationary source test method for CPM 
will provide for more accurate and precise measurement of all PM, the 
addition of PM2.5 as an indicator of health and welfare 
effects by the 1997 NAAQS revisions generates the need to quantify 
PM2.5 emissions from stationary sources. To respond to this 
need, we are proposing revisions to incorporate this capability into 
the test method for filterable PM10.

III. This Action

    This action proposes to provide the capability of measuring 
PM2.5 using Method 201A and to provide for more accurate 
measurement of the filterable and condensable components of fine PM 
(particles with mean aerodynamic diameters less than or equal to 2.5 m) 
and coarse PM (particles with mean aerodynamic diameters less than or 
equal to 10 m) when using Method 202. Method 201A proposed amendments 
would add a particle-sizing cyclone to the sampling train. Method 202 
proposed amendments would reduce the formation of sulfuric acid 
artifact by at least an additional 90 percent (compared to our 
recommended procedures for the existing Method 202), provide for 
greater consistency between testing contractors in method application, 
improve the precision of the method, and provide for more accurate 
quantification of direct (i.e., primary) PM emissions to the ambient 
air (the method will not measure secondarily-formed PM). The proposed 
amendments would also affect the measurement of total PM, 
PM10, and PM2.5. Additionally, we are proposing 
to revise the format of Methods 201A and 202 to be consistent with the 
format developed by EPA's Environmental Monitoring Management Council 
(EMMC). A guidance document describing the EMMC format can be found at 
the following Internet address: https://www.epa.gov/ttn/emc/guidlnd/gd-045.pdf.

A. What Are the Proposed Amendments to Method 201A?

    On July 18, 1997 (62 FR 38652), we revised the NAAQS for PM to add 
new standards for fine particles, using PM2.5 as the 
indicator. This action will modify the current Method 201A sampling 
train configuration to allow for measurement of filterable 
PM10, filterable PM2.5, or both filterable 
PM10 and filterable PM2.5 from stationary 
sources. These amendments combine the existing method with the 
PM2.5 cyclone to create a sampling train that includes a 
total of two cyclones (one cyclone to size particles with aerodynamic 
diameters greater than 10 m and one cyclone to size particles with 
aerodynamic diameters greater than 2.5 m) and a final filter to collect 
particles with aerodynamic diameters less than or equal to 2.5 m. The 
PM2.5 cyclone would be inserted between the PM10 
cyclone and the filter of the Method 201A sampling train.
    We are not proposing any amendments to address the use of this 
method when the stack gas has entrained moisture or when the method is 
used for stack gases with high temperatures. In July 1979, we published 
a research document (EPA-600/7-79-166) to report the preliminary 
development of a method for measuring and characterizing the particles 
in the vent stream from a wet scrubber used to control sulfur oxide 
emissions. The method was based on the use of a heated, electrified 
wire placed in the vent stream. When a water droplet impacted the wire, 
the electric current flowing through the wire was attenuated in 
proportion to the size of the water droplet. We decided it was not 
appropriate to promulgate the preliminary method and, at this time, we 
are not aware of any commercially-available equipment that can 
determine the aerodynamic size of PM contained in, or dissolved in, 
liquid water droplets as they would exist in the ambient air following 
release and evaporation in the ambient air. While we are aware of 
several optical aerosol droplet spectrometers for measuring the size 
distribution of liquid droplets in exhaust gases, we are not aware of 
any commercial instruments that can measure size distributions of 
particles emitted from stationary sources. We also lack knowledge on 
the relative effects of solids concentration in the liquid droplets and 
the possible presence of dry particles in addition to the liquid 
droplets. Consequently, we recommend the use of EPA Method 5 (40 CFR 
Part 60, Appendix A-3--Determination of Particulate Matter Emissions 
from Stationary Sources) when measuring PM in stacks with saturated 
water vapors containing entrained water droplets. With this application 
of EPA Method 5,

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all of the collected material would be considered PM2.5.

B. What Are the Proposed Amendments to Method 202?

    This action proposes amendments incorporating modifications that 
would reduce the formation of artifacts at both low and high 
concentrations of SO2 in the sample gas stream. The 
modifications were developed based on the method evaluations discussed 
in Section II.C.2 of this preamble.
    Method 202, as promulgated in 1991, is a set of sampling procedures 
for collecting PM in water-filled impingers and a set of sample 
recovery procedures that are performed on the water following its 
collection. The water-filled impingers are nearly identical to the four 
chilled impingers used in standard stationary source sampling trains 
for PM (e.g., Method 5 and Method 17 of Appendix A-3 and A-6, 40 CFR 
Part 60). In principle, CPM is collected in the impinger portion of a 
Method 17-type sampling train. Our preferred operation of the 
promulgated method requires that the impinger contents be purged with 
nitrogen after the test run to remove dissolved SO2 gas from 
the impinger contents. The impinger solution is then extracted with 
methylene chloride to separate the organic CPM from the inorganic CPM. 
The organic and aqueous fractions are then dried and the residues 
weighed. The sum of both fractions represents the total CPM.
    These proposed amendments to Method 202 sampling train and sample 
recovery procedures would achieve at least an additional 90 percent 
reduction in sulfuric acid artifact formation compared to the current 
Method 202 using the nitrogen purge option, provide testing contractors 
with a more standardized application of the method, improve the 
precision of the method, and quantify more accurately direct PM 
emission to the ambient air.
    The proposed changes to the sampling train of this method include:
     Installing a condenser between the filter in the front-
half of the sample train and the first impinger to cool the sample 
gases to ambient temperature (less than 30 [deg]C);
     Installing a recirculation pump in the ambient water bath 
to supply cooling water to the condenser;
     Changing the first two impingers from wet to dry, and 
placing these two dry impingers in a water bath at ambient temperature 
(less than 30 [deg]C) (the first dry impinger will use a short-stem 
insert, and the second dry impinger will use a long-stem insert);
     Requiring the use of an out-of-stack, low-temperature 
filter (i.e., the CPM filter), as described in EPA Method 8, between 
the second and third impingers (a Teflon filter is used in place of the 
fiberglass filter described in EPA Method 8); and
     Requiring that the temperature of the sample gas drawn 
through the CPM filter be maintained at ambient temperature (less than 
30 [deg]C).

It should be noted that under Method 202, the use of a CPM filter is an 
optional procedure that is used typically if the collection efficiency 
of the impinger is suspected to be low. These proposed amendments would 
make the use of a CPM filter a required procedure.
    The proposed changes to Method 202 include:
     Extracting the CPM filter with water and organic solvent;
     Evaporating the liquid collected in the impingers in an 
oven or on a hot plate down to a minimum volume of 10 milliliters, 
instead of all the way to dryness;
     Evaporating the remaining liquid to dryness at ambient 
temperature prior to neutralization with ammonium hydroxide;
     Titrating the reconstituted residue with 0.1 normal 
ammonium hydroxide and a pH meter;
     Evaporating the neutralized liquid to a minimum volume of 
10 milliliters in an oven or hot plate;
     Evaporating the final volume to dryness at ambient 
temperature; and
     Weighing the CPM sample residue to constant weight after 
allowing a minimum of 24 hours for equilibration in a desiccator.

Note that the requirements to evaporate liquids at ambient temperature 
and to titrate the reconstituted liquid exist already as options under 
this method. These optional steps are typically performed to retain CPM 
that might be lost at higher evaporation temperatures. Under these 
proposed amendments, these options would be required procedures.

C. How Will the Proposed Amendments to Methods 201A and 202 Affect 
Existing Emission Inventories, Emission Standards, and Permit Programs?

    We anticipate that, over time, the changes in the test methods 
proposed in this action will result in, among other positive outcomes, 
more accurate emissions inventories of direct PM emissions and 
emissions standards that are more indicative of the actual impact of 
the source on the ambient air quality.
    Accurate emission inventories are critical for regulatory agencies 
to develop the control strategies and demonstrations necessary to 
attain air quality standards. If implemented, the proposed test method 
revisions would have the potential to improve our understanding of PM 
emissions due to the increased availability of more accurate emission 
tests and, eventually, through the incorporation of less biased test 
data into existing emissions factors. For CPM, the use of the proposed 
method would likely reveal a reduced level of CPM emissions from a 
source compared to the emissions that would have been measured using 
Method 202, as typically performed. However, there may be some cases 
where the proposed test method would reveal an increased level of CPM 
emissions from a source, depending on the relative emissions of 
filterable and CPM emissions from the source. For example, the existing 
Method 202 allows complete evaporation of the water containing 
inorganic PM at 105 [deg]C (221 [deg]F), where the proposed revision 
requires the last 10 ml of the water to be evaporated at room 
temperature (not to exceed 30 [deg]C (85 [deg]F)) thereby retaining the 
CPM that would evaporate at the increased temperature.
    Prior to our adoption of the 1997 PM2.5 NAAQS, several 
State and local air pollution control agencies had developed emission 
inventories that included CPM. Additionally, some agencies established 
enforceable CPM emissions limits or otherwise required that PM 
emissions testing include measurement of CPM. While this approach was 
viable in cases where the same test method was used to develop the CPM 
regulatory limits and to demonstrate facility compliance, there are 
substantial inconsistencies within and between States regarding the 
completeness and accuracy of CPM emission inventories and the test 
methods used to measure CPM emissions and to demonstrate facility 
compliance.
    These amendments would serve to mitigate the potential difficulties 
that can arise when we and other regulatory entities attempt to use the 
test data from State and local agencies whose CPM test methods are 
inconsistent to develop emission factors, determine program 
applicability, or to establish emissions limits for CPM emission 
sources within a particular jurisdiction. For example, problems can 
arise when the test method used to develop a CPM emission limit is not 
the same as the test method specified in the rule for demonstrating 
compliance because the different test methods may quantify different 
components of PM (e.g., filterable versus condensable). Also, when 
emissions from State inventories are modeled to assess compliance with

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the NAAQS, the determination of direct PM emissions may be biased high 
or low, depending on the test methods used to estimate PM emissions, 
and the atmospheric conversion of SO2 to sulfates (or 
SO3) may be inaccurate or double-counted. Additionally, some 
State and local regulatory authorities have assumed that EPA Method 5 
of Appendix A-3 to 40 CFR Part 60 (Determination of Particulate Matter 
Emissions from Stationary Sources) provides a reasonable estimate of 
PM10 emissions. This assumption is incorrect because Method 
5 does not provide particle sizing of the filterable component and does 
not quantify particulate caught in the impinger portion of the sampling 
train. Similar assumptions for measurements of PM2.5 will 
result in greater inaccuracies.
    With regard to State permitting programs, we recognize that, in 
some cases, existing Best Available Control Technology (BACT), Lowest 
Achievable Emission Rate (LAER), or Reasonably Available Control 
Technology (RACT) limits have been based on an identified control 
technology, and that the data used to determine the performance of that 
technology and establish the limits may have focused on filterable PM 
and thus did not completely characterize PM emissions to the ambient 
air. While the source test methods used by State programs that 
developed the applicable permit limit may not have fully characterized 
the PM emissions, we have no information that would indicate that the 
test methods are inappropriate indicators of the control technologies' 
performance for the portion of PM emissions that was addressed by the 
applicable requirement. As promulgated in the Clean Air Fine Particle 
Implementation Rule, after January 1, 2011, States are required to 
consider inclusion of CPM emissions in new or revised emissions limits 
which they establish. We will defer to the individual State's judgment 
as to whether, and at what time, it is appropriate to revise existing 
facility emission limits or operating permits to incorporate 
information from the revised CPM test method when it is promulgated.
    With regard to operating permits, the Title V permit program does 
not generally impose new substantive air quality control requirements. 
In general, once emissions limits are established as CAA requirements 
under the SIP or a SIP-approved pre-construction review permit, they 
are included in the Title V permits. Obviously, Title V permits may 
have to be updated to reflect any revision of existing emission limits 
or new emission limits created in the context of the underlying 
applicable requirements. Also, if a permit contains the previously 
promulgated test methods, it is not a given that the permit would 
always have to be revised should these test methods changes be 
finalized (e.g., where test methods are incorporated into existing 
permits through incorporation by reference, no permit terms or 
conditions would necessarily have to change to reflect changes to those 
test methods). In any event, the need for action in the permitting 
context due to these proposed changes to the test methods would be 
controlled by several factors, such as the exact wording of the 
existing operating permit, the requirements of the EPA-approved SIP, 
and any changes that may be made to pre-construction review permits 
with respect to a particular source test method that did not include 
CPM or on a set of procedures in Method 202 which underestimated 
emissions.
    In recognition of these issues, the Clean Air Fine Particle 
Implementation Rule contains provisions establishing a transition 
period for developing emission limits for condensable direct 
PM2.5 that are needed to demonstrate attainment of the 
PM2.5 NAAQS. As discussed in the April 25, 2007, Clean Air 
Fine Particle Implementation Rule (72 FR 20586) and in the May 16, 
2008, promulgation of the New Source Review Program Implementation for 
fine particulate matter (73 FR 28321), the transition period, which 
ends January 1, 2011, allows time to resolve and adopt appropriate 
testing procedures for CPM emissions and to collect total primary 
(filterable and condensable) PM2.5 emissions data that are 
more representative of the emissions of each source in their areas. In 
the PM2.5 NSR Implementation Rule, we stated that as part of 
this test methods rulemaking, we would ``take comment on an earlier 
closing date for the transition period in the NSR program if we are on 
track to meet our expectation to complete the test method rule much 
earlier than January 1, 2011.'' See 73 FR at 28344. Accordingly, we are 
hereby soliciting comments on ending the NSR transition period for CPM 
on a date 60 to 90 days after the promulgation date of this test 
methods rulemaking.
    During the transition period, we are available to provide technical 
support to States, as requested, in establishing emissions testing 
requirements. We will also solicit the involvement of interested 
stakeholders to collect new direct filterable and CPM emissions data 
using methodologies that provide more representative data of a source's 
direct PM2.5 emissions. These data will be used by us, 
States, and others to improve emissions factors and to help establish 
or revise source emissions limits in implementation plans. The 
transition period will also provide time for additional method 
evaluations. During the transition period, we expect that some States 
will continue to develop more complete inventories of direct 
PM2.5 emissions, particularly for CPM. As needed to 
demonstrate attainment of the PM NAAQS, we also expect States to 
address the control of direct PM2.5 emissions, including 
CPM, with any new actions taken after January 1, 2011 and to address 
CPM emissions in any direct PM2.5 regulations or limits 
developed under any new PM NAAQS.
    As with other methods, any new procedures approved by us will 
produce data that will be incorporated into the tools (e.g., emission 
factors, emission inventories, air quality modeling) used to assess the 
attainment of air quality standards. However, we do not believe that it 
is necessary to update continually the assessment tools or revise 
previous air quality analyses until evidence is presented that a mid-
course corrective action is needed to achieve the air quality standards 
(a mid-course review is required by April 2011 for each area with an 
approved attainment date in 2014 or 2015). At that time, updated 
inventories and air quality models may be needed to identify and 
characterize the emission sources that are impeding adequate progress 
towards attaining the air quality standards. Additionally, the new test 
data could be used to improve the applicability and performance 
evaluations of various control technologies.

D. Request for Comments

    We encourage stakeholders to continue to participate in the process 
to refine Methods 201A and 202. We are requesting public comments on 
all aspects of the proposed test methods. EPA has already engaged 
several stakeholder groups as described in Section II.C of this 
preamble. Stakeholders and other members of the public who have not yet 
participated are encouraged to submit comments. EPA is soliciting as 
many constructive comments as possible in order to make the most 
appropriate changes to the methods.
    We are specifically interested in recommended alternatives to 
replace what we have proposed. When submitting comments on alternative 
approaches, please submit supporting information to substantiate the 
improvements that are achieved with your recommendation. For

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recommended changes to the procedures, include supporting technical 
data and any associated cost information. For example, if you are 
proposing an alternative procedure, include data or information that 
would demonstrate how the alternative procedure would equal or improve 
the bias and precision of the proposed methods. In addition, provide 
data or cost information that would show the cost implications to 
testing companies and analytical laboratories of implementing the 
alternative procedure. Although our request for comments is not limited 
to these items, the following are examples of items for which we are 
specifically requesting comment.
1. Items Associated With Both Test Methods
    The proposed test methods are based upon EPA's assessment of 
comments made on the Clean Air Fine Particle Implementation Rule (April 
25, 2007, 70 FR 20586). Commenters expressed that there is an 
overarching need for test methods that are unbiased with respect to 
primary particulate matter emissions to the atmosphere and that the 
test methods must provide a high degree of consistency (precision) in 
these measurements. As a result, we reduced the numerous options and 
alternative procedures in the existing methods to a single set of 
prescriptive procedures that already existed within the methods. In 
addition, we made a few minor changes to reduce further the bias caused 
by sulfate artifacts. We are requesting comments on the specific set of 
procedures we have proposed and any replacement procedures that would 
be less demanding but that would achieve or improve bias and precision. 
We are also requesting comments on our decision to eliminate options or 
alternatives within the existing methods that may not achieve 
comparable results. If we were to consider alternative procedures that 
may not achieve comparable results, then what level of difference would 
be acceptable?
2. Items Associated With Method 201A
    Regarding this proposed method, stakeholders have commented on the 
sample duration that would be required to collect a weighable mass. EPA 
is requesting comments on alternative methodologies or hardware that 
would reduce the sample duration in order to reach a reasonable 
detection limit or to demonstrate that emissions are below the 
regulatory limit. Commenters should provide information or data, 
including cost information, which supports their recommendation.
    Stakeholders have expressed concern about the configuration and 
size of the proposed sampling train. Specifically, commenters have 
expressed concern that the size and length of the combined 
PM10 cyclone and the PM2.5 cyclone and filter 
require larger port opening(s) and a very large stack cross section to 
minimize blockage. In addition, stakeholders have stated that it is 
difficult to maintain stack temperature in the sampling train. 
Therefore, EPA requests comments on alternatives to the proposed 
procedures or hardware. EPA requests comments on alternative procedures 
or configurations that would reduce the blockage. EPA also requests 
comments on alternative configurations that would allow testers to 
maintain stack temperature in the sampling train, thus reducing or 
eliminating condensation in the primary or filterable particulate 
portions of the method. Recommendations to revise the sampling train 
size or configuration should include an assessment of the impacts of 
the recommended revisions on the sample size, required sample duration, 
and ability to collect a representative sample. Commenters should 
provide information or data, including cost information that supports 
their recommendation.
3. Items Associated With Method 202
    Stakeholders originally expressed concern about the formation of 
artifacts in Method 202 when sulfur dioxide was present in the stack 
gas. Based on laboratory experiments, the proposed revision to Method 
202 eliminates at least an additional 90 percent of the artifact over 
the best practices procedures of the existing Method 202. In addition, 
the laboratory experiments show that the proposed revision to Method 
202 reduces artifact at or below the detection limits of the method. 
EPA requests comments on any further concerns with the formation of 
artifacts in the proposed method.
    Stakeholders have expressed concern about glassware cleaning. 
Specifically, stakeholders have questioned the requirement to bake 
glassware at 300 [deg]C for 6 hours prior to use in order to reduce the 
background level of CPM. Stakeholders have stated that many stack 
testing firms and some analytical laboratories may not have ovens that 
can achieve this temperature. EPA requests information on the 
performance of a lower temperature oven in effectively reducing the 
blank level of CPM.
    Another stakeholder concern is whether glassware needs to be 
completely cleaned between sampling runs. The proposed method requires 
clean glassware at the start of each new source category test. EPA 
requests comments on alternatives that would minimize the cost of 
glassware preparation and reduce bias due to carryover from tests at 
the same source category and between source categories. Commenters 
should submit data or information to demonstrate that their alternative 
procedure would reduce or minimize the carryover or blank and would 
minimize the cost to prepare glassware.
    Stakeholders expressed concern about the need for Method 202 
following filtration at less than 30 [deg]C (85 [deg]F). EPA requests 
comments on how to clarify when Method 202 is or is not required.
    Stakeholders have expressed concern about the appropriate type of 
CPM filter required by the proposed method. EPA requests comments on 
the construction material and porosity of the filter. Commenters should 
address the capture efficiency required by the method (i.e., the filter 
must have an efficiency of at least 99.95 percent (<0.05 percent 
penetration) on 0.3 micron particles). Commenters should include how 
their alternative would minimize the blank contribution from the 
filters.
    Commenters have expressed concern about the additional analytical 
steps required to process the CPM filter. The proposed method requires 
extraction and combination of the filter extract with the appropriate 
impinger samples to accurately collect and measure sulfuric acid and 
other condensable material. Commenters should address alternative 
procedures for CPM filter analysis that would generate precise and 
unbiased analysis of CPM collected on the CPM filter.
    Stakeholders have expressed concern about maintaining the stack gas 
flow through the Teflon[supreg] membrane filter. Stakeholders have 
commented on their need to use a supplementary support filter to 
maintain flow through the sample filter. EPA requests comments 
regarding the use of a support filter that would help maintain stack 
gas flow while minimizing or eliminating the support filter's 
contribution to the sample mass. EPA requests comments on the use of 
this alternative and its potential impact on bias and precision, as 
well as its potential impact on cost.

IV. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order (EO) 12866 (58 FR 51735, October 4, 1993), 
this proposed action is a ``significant regulatory action'' since it 
raises novel

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legal or policy issues arising out of legal mandates, the President's 
priorities, or the principles set forth in this Executive Order. 
Accordingly, EPA submitted this proposed 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.

B. Paperwork Reduction Act

    This proposed action does not impose an information collection 
burden under the provisions of the Paperwork Reduction Act, 44 U.S.C. 
3501 et seq. Burden is defined at 5 CFR 1320.3(b). The proposed 
amendments do not contain any reporting or recordkeeping requirements. 
The proposed amendments revise two existing source test methods to 
allow one method to perform additional particle sizing at 2.5 
micrometers and to improve the precision and accuracy of the other test 
method.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have a significant economic impact on a substantial 
number of small entities. Small entities include small businesses, 
small organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of this rule on small 
entities, small entity is defined as: (1) A small business as defined 
by the Small Business Administration's (SBA) regulations at 13 CFR 
121.201; (2) a small governmental jurisdiction that is a government of 
a city, county, town, school district or special district with a 
population of less than 50,000; and (3) a small organization that is 
any not-for-profit enterprise which is independently owned and operated 
and is not dominant in its field.
    After considering the economic impacts of this proposed rule on 
small entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. We do not 
anticipate that the proposed changes to Methods 201A and 202 will 
result in a significant economic impact on small entities. Most of the 
emission sources that will be required by State regulatory agencies 
(and Federal regulators after 2011) to conduct tests using the revised 
methods are those that have PM emissions of 100 tons per year or more. 
EPA expects that few, if any, of these emission sources will be small 
entities.
    Although this proposed rule will not have a significant economic 
impact on a substantial number of small entities, EPA nonetheless has 
tried to reduce the impact of this rule on small entities. In this 
preamble, we explained that this rule does not require any entities to 
use these proposed test methods. Such a requirement would be mandated 
by a separate independent regulatory action. We indicated that upon 
promulgation of this rule, some entities may be required to use these 
test methods as a result of existing permits or regulations. Since the 
cost to use the proposed test methods is comparable to the cost of the 
methods they replace, little or no significant economic impact to small 
entities will accompany the increased precision and accuracy of the 
revised test methods which are proposed. We also indicated that after 
January 1, 2011, when the transition period established in the Clean 
Air Fine Particle Implementation Rule expires, States are required to 
consider inclusion of pollutants measured by these test methods in new 
or revised regulations. The economic impacts caused by any new or 
revised State regulations for fine PM would be associated with those 
State rules and not with this proposal to modify the existing test 
methods. Consequently, we believe that this rule imposes little if any 
adverse economic impact to small entities. However, we continue to be 
interested in the potential impacts of the proposed rule on small 
entities and welcome comments on