[Federal Register Volume 75, Number 244 (Tuesday, December 21, 2010)]
[Rules and Regulations]
[Pages 80118-80172]
[FR Doc No: 2010-30847]

-----------------------------------------------------------------------

Part II

Environmental Protection Agency

-----------------------------------------------------------------------

40 CFR Part 51

Methods for Measurement of Filterable PM10 and
PM2.5 and Measurement of Condensable PM Emissions From
Stationary Sources; Final Rule

Federal Register / Vol. 75 , No. 244 / Tuesday, December 21, 2010 /
Rules and Regulations

-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 51

[EPA-HQ-OAR-2008-0348; FRL-9236-2]
RIN 2060-AO58

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

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This action promulgates amendments to Methods 201A and 202.
The final amendments to Method 201A add a particle-sizing device to
allow for sampling of particulate matter with mean aerodynamic
diameters less than or equal to 2.5 micrometers (PM2.5 or
fine particulate matter). The final amendments to Method 202 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. Additionally, the final
amendments to Method 202 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.
    This action also announces that EPA is taking no action to affect
the already established January 1, 2011 sunset date for the New Source
Review (NSR) transition period, during which EPA is not requiring that
State NSR programs address condensable particulate matter emissions.

DATES: This final action is effective on January 1, 2011.

ADDRESSES: EPA has established a docket for this action under Docket ID
No. EPA-HQ-OAR-2008-0348. All documents are listed in the http://www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., confidential business
information (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 form. Publicly available docket
materials are available either electronically at http://www.regulations.gov or in hard copy at the EPA Docket Center EPA/DC,
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<PHONE_NUMBER>, and the telephone number for the Air
Docket Center is<PHONE_NUMBER>.

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;<PHONE_NUMBER>; e-mail address:
<EMAIL_ADDRESS>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:<PHONE_NUMBER>; fax
number:<PHONE_NUMBER>; e-mail address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:
    Acronyms and Abbreviations. The following acronyms and
abbreviations are used in this document.

[Delta]pmax maximum velocity pressure
[Delta]pmin minimum velocity pressure
[mu]m micrometers
ASTM American Society for Testing and Materials
AWMA Air and Waste Management Association
CAA Clean Air Act
CBI confidential business information
CCM Controlled Condensation Method
CPM condensable PM
DOP dioctyl phthalate
DOT Department of Transportation
DQO data quality objective
MSHA Mine Safety and Health Administration
NAAQS National Ambient Air Quality Standards
NSR New Source Review
NTTAA National Technology Transfer and Advancement Act of 1995
OSHA Occupational Safety and Health Administration
PCB polychlorinated biphenyl
PM particulate matter
PM10 particulate matter less than or equal to 10
micrometers
PM2.5 particulate matter less than or equal to 2.5
micrometers
ppmw parts per million by weight
PTFE polytetrafluoropolymer
RCRA Resource Conservation and Recovery Act
RFA Regulatory Flexibility Act
SBA Small Business Administration
SIP State Implementation Plan
SO2 sulfur dioxide
TDS total dissolved solids
TTN Technology Transfer Network
UMRA Unfunded Mandates Reform Act
www World Wide Web

    The information in this preamble is organized as follows:

I. General Information
    A. Does this action apply to me?
    B. Where can I obtain a copy of this action and other related
information?
    C. What is the effective date?
    D. Judicial Review
II. Background
    A. Why is EPA issuing this final action?
    B. Particulate Matter National Ambient Air Quality Standards
    C. Measuring PM Emissions
    1. Method 201A
    2. Method 202
III. Summary of Changes Since Proposal
    A. Method 201A
    B. Method 202
    C. How will the final amendments to methods 201A and 202 affect
existing emission inventories, emission standards, and permit
programs?
IV. Summary of Final Methods
    A. Method 201A
    B. Method 202
V. Summary of Public Comments and Responses
    A. Method 201A
    B. Method 202
    C. Conditional Test Method 039 (Dilution Method)
VI. 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
    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
    K. Congressional Review Act

I. General Information

A. Does this action apply to me?

    This action applies to you if you operate a stationary source that
is subject to applicable requirements to control or measure total
particulate matter (PM), total PM with mean aerodynamic diameters less
than or equal to 10 micrometers ([mu]m) (PM10), or total
PM2.5, where EPA Method 202 is incorporated as a component
of the applicable test method.
    In addition, this action applies to you if federal, State, or local
agencies take certain additional independent actions. For example, this
action applies to sources through actions by State and local agencies
that implement condensable PM (CPM) control measures to attain the
National Ambient

Air Quality Standards (NAAQS) for PM2.5 and specify the use
of Method 202 to demonstrate compliance with the control measures.
State and local agencies that specify the use of Method 201A or 202
would have to implement the following: (1) Adopt this method in rules
or permits (either by incorporation by reference or by duplicating the
method in its entirety), and (2) promulgate an emissions limit
requiring the use of Method 201A or 202 (or an incorporated method
based upon Method 201A or 202). This action also applies 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 (NSR), which specify
the use of Method 201A or 202 to demonstrate compliance with the
control measures.
    The source categories and entities potentially affected include,
but are not limited to, the following:

------------------------------------------------------------------------
                                                   Examples of regulated
           Category                 NAICS \a\             entities
------------------------------------------------------------------------
Industry......................  332410...........  Fossil fuel steam
                                                    generators.
                                332410...........  Industrial,
                                                    commercial,
                                                    institutional steam
                                                    generating units.
                                332410...........  Electricity
                                                    generating units.
                                324110...........  Petroleum refineries.
                                562213...........  Municipal waste
                                                    combustors.
                                322110...........  Pulp and paper mills.
                                325188...........  Sulfuric acid plants.
                                327310...........  Portland cement
                                                    plants.
                                327410...........  Lime manufacturing
                                                    plants.
                                211111, 212111,    Coal preparation
                                 212112, 212113.    plants.
                                331312, 331314...  Primary and secondary
                                                    aluminum plants.
                                331111, 331513...  Iron and steel
                                                    plants.
                                321219, 321211,    Plywood and
                                 321212.            reconstituted
                                                    products plants.
------------------------------------------------------------------------
\a\ North American Industrial Classification System.

B. 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
these final rules are also available on the World Wide Web (http://www.epa.gov/ttn/) through the Technology Transfer Network (TTN).
Following the Administrator's signature, a copy of these final rules
will be posted on the TTN's policy and guidance page for newly proposed
or promulgated rules at http://www.epa.gov/ttn/oarpg. The TTN provides
information and technology exchange in various areas of air pollution
control.

C. What is the effective date?

    The final rule amendments are effective on January 1, 2011. Section
553(d) of the Administrative Procedure Act (APA), 5 U.S.C. Chapter 5,
generally provides that rules may not take effect earlier than 30 days
after they are published in the Federal Register. EPA is issuing this
final rule under section 307(d)(1) of the Clean Air Act, which states:
``The provisions of section 553 through 557 * * * of Title 5 shall not,
except as expressly provided in this section, apply to actions to which
this subsection applies.'' Thus, section 553(d) of the APA does not
apply to this rule. EPA is nevertheless acting consistently with the
purposes underlying APA section 553(d) in making this rule effective on
January 1, 2011. Section 5 U.S.C. 553(d)(3) allows an effective date
less than 30 days after publication ``as otherwise provided by the
agency for good cause found and published with the rule.'' As explained
below, EPA finds that there is good cause for these rules to become
effective on or before January 1, 2011, even if this date is not 30
days from date of publication in the Federal Register.
    While this action is being signed prior to December 1, 2010, there
may be a delay in the publication of this rule as it contains many
complex diagrams, equations, and charts, and is relatively long in
length. The purpose of the 30-day waiting period prescribed in 5 U.S.C.
553(d) is to give affected parties a reasonable time to adjust their
behavior and prepare before the final rule takes effect. Where, as
here, the final rule will be signed and made available on the EPA
website more than 30 days before the effective date, but where the
publication may be delayed due to the complexity and length of the
rule, that purpose is still met. Moreover, since permitting authorities
and regulated entities may need to rely on the methods described in
these rules to carry out requirements of the SIP and NSR implementation
rules that become effective on January 1, 2011 (see section III.C,
infra), there would be unnecessary regulatory confusion if a
publication delay caused this rule to become effective after January 1,
2011. Accordingly, we find good cause exists to make this rule
effective on or before January 1, 2011, consistent with the purposes of
5 U.S.C. 553(d)(3).\1\
---------------------------------------------------------------------------

    \1\ We recognize that this rule could be published at least 30
days before January 1, 2011, which would negate the need for this
good cause finding, and we plan to request expedited publication of
this rule in order to decrease the likelihood of a publication
delay. However, as we cannot know the date of publication in advance
of signing this rule, we are proceeding with this good cause finding
for an effective date on or before January 1, 2011, in an abundance
of caution in order to avoid the unnecessary regulatory confusion
noted above.
---------------------------------------------------------------------------

D. Judicial Review

    Under section 307(b)(1) of the Clean Air Act (CAA), judicial review
of this final action is available only by filing a petition for review
in the United States Court of Appeals for the District of Columbia
Circuit by February 22, 2011. Under CAA section 307(b)(2), the
requirements established by this action may not be challenged
separately in any civil or criminal proceedings brought by EPA to
enforce these requirements.
    Section 307(d)(7)(B) of the CAA further provides that ``[o]nly an
objection to a rule or procedure which was raised with reasonable
specificity during the period for public comment (including any public
hearing) may be raised during judicial review.'' This section also
provides a mechanism for EPA to convene a proceeding for
reconsideration, ``[i]f the person raising an objection can demonstrate
to EPA that it was impracticable to raise such objection within [the
period for public comment] or if the grounds for such objection arose
after the period for public comment (but within the time specified for
judicial review) and if such objection is of central relevance to the
outcome of the rule.'' Any person seeking to make such a demonstration
to us should submit a Petition for Reconsideration to the Office of the
Administrator, U.S. EPA, Room 3000,

Ariel Rios Building, 1200 Pennsylvania Ave., NW., Washington, DC 20460,
with a copy to both the person(s) listed in the preceding FOR FURTHER
INFORMATION CONTACT section, and the Associate General Counsel for the
Air and Radiation Law Office, Office of General Counsel (Mail Code
2344A), U.S. EPA, 1200 Pennsylvania Ave., NW., Washington, DC 20460.

II. Background

A. Why is EPA issuing this final action?

    Section 110 of the CAA, as amended (42 U.S.C. 7410), requires State
and local air pollution control agencies to develop, and submit for EPA
approval, State Implementation Plans (SIP) that provide for the
attainment, maintenance, and enforcement of the NAAQS in each air
quality control region (or portion thereof) within each State. The
emissions inventories and analyses used in the State's attainment
demonstrations must consider PM10 and PM2.5
emissions from stationary sources that are significant contributors of
primary PM10 and PM2.5 emissions. Primary or
direct emissions are the solid particles or liquid droplets emitted
directly from an air emissions source or activity, and the gaseous
emissions or liquid droplets from an air emissions source or activity
that condense to form PM or liquid droplets at ambient temperatures.
    Appendix A to subpart A of 40 CFR part 51 (Requirements for
Preparation, Adoption, and Submittal of Implementation Plans) 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 condenses and/or reacts upon
cooling and dilution in the ambient air to form solid or liquid PM
immediately after discharge from the stack. In response to the need to
quantify primary PM10 and PM2.5 emissions from
stationary sources, EPA previously developed and promulgated Method
201A (Determination of PM10 Emissions (Constant Sampling
Rate Procedure)) and Method 202 (Determination of Condensable
Particulate Emissions from Stationary Sources) in 40 CFR part 51,
appendix M (Recommended Test Methods for State Implementation Plans).
    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 that 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.
    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 in 1991, 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.
    In this action, we are finalizing amendments to Methods 201A and
202 to improve the measurement of fine PM emissions. For Method 201A,
the final amendments add a particle-sizing device to allow for sampling
of PM2.5 emissions. For Method 202, the final amendments
will (1) revise the sample collection and recovery procedures of the
method to reduce the potential for formation of reaction artifacts that
are not related to the primary emission of CPM from the source but may
be counted erroneously as CPM when using Method 202, and (2) eliminate
most of the hardware and analytical options in the existing method.
These changes increase the precision of Method 202 and improve the
consistency in the measurements obtained between source tests performed
under different regulatory authorities.

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 of the CAA (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 of the CAA (42 U.S.C.
7409) directs the Administrator to propose and promulgate primary and
secondary NAAQS for pollutants listed under CAA section 108 to protect
public health and welfare, respectively. Section 109 of the CAA 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.
    Initially, EPA established the PM NAAQS 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 PM NAAQS, 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 PM NAAQS, 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. 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 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 PM NAAQS (62 FR 55201),
including the 1997 PM2.5 standards and the 1987
PM10 standards. On October 17, 2006, EPA issued its final
decision to revise the primary and secondary PM NAAQS 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 State
and local air pollution control agencies to develop and submit plans
(SIP) 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. 40 CFR part 51 (Requirements for
Preparation, Adoption, and Submittal of Implementation Plans) specifies
the requirements for SIP. 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 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
    Method 201A is a test method for measuring filterable
PM10 emissions from stationary sources. 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 total PM10 mass. To measure PM10 in
stacks where water droplets are known to exist, EPA's Technical
Information Document 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
    Method 202 measures CPM from stationary sources. Method 202
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. Method 202 has been
used successfully in regulatory programs where the emission limits and
compliance demonstrations are established based on a consistent
application of the method and its associated options. However, when the
same emission source is tested using different combinations of the
optional procedures, there appears 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. We consistently
maintain that 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
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 EPA's Method 5 Impinger Catch
for Measuring Condensible Matter from Stationary Sources'' at http://www.epa.gov/ttn/emc/methods/m202doc1.pdf.
    The 1998 study verified the need for a nitrogen purge when
SO2 is present in stack gas and 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 http://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, as
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 (available at http://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 conducted two workshops in Research Triangle
Park, NC to present and request comments on our plan for evaluating
potential modifications to Method 202 that would reduce artifact
formation, and also to discuss (1) Our progress in characterizing the
performance of the modified method, (2) issues that require additional
investigation, (3) the results of our laboratory studies, and (4) our
commitments to extend the investigation through stakeholders external
to EPA. Another meeting was held 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 http://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, promulgate 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 promulgating revisions to incorporate this
capability into the test method for filterable PM10.

III. Summary of Changes Since Proposal

    The methods in this final action contain several changes that were
made as a result of public comments. The following sections present a
summary of the changes to the methods. We explain the reasons for these
changes in detail in the Summary of Public Comments and Responses
section of this preamble.

A. Method 201A

    Method 201A contains the following changes and clarifications:
     Revised Section 1.5 to clarify that Method 201A cannot be
used to measure emissions from stacks that have entrained moisture
droplets (e.g., from a wet scrubber stack).
     Removed the language in proposed Section 1.5 regarding
ambient air contributions to PM. The decision to correct results for
ambient air contributions is up to the permitting or regulatory
authority.
     Added definitions of Primary PM, Filterable PM, Primary
PM2.5, Primary PM10, and CPM to Section 3.0.
     Added a requirement to Sections 6.1.3 and 8.6.3 stating
that the filter must not be compressed between the gasket and the
filter housing.
     Clarified the sample recovery and analysis equipment in
Section 6.2, including acceptable materials of construction, analytical
balance, and fluoropolymer (polytetrafluoroethylene) beaker liners.
     Revised Section 6.2 to add performance-based, residual
mass contribution specifications for containers rather than specifying
the type of container that must be used (storage containers must not
contribute more than 0.1 mg of residual mass to the CPM measurements).
     Revised Section 8.3.1 (regarding sampling ports) to state
that a 4-inch port should be adequate for the single PM2.5
(or single PM10) sampling apparatus. However, testers will
not be able to use conventional 4-inch ports if the combined dimension
of the PM10 cyclone and the nozzle extending from the
cyclone exceeds the internal diameter of the port.
     Clarified the sampling procedures in Section 8.3.1 for
cases where the PM2.5 cyclone is used without the
PM10 cyclone. In these cases, samples are collected using
the procedures specified in Section <IP_ADDRESS> of EPA Method 1, and the
sampling time is extended at the replacement sampling point to include
the duration of the unreachable traverse points.
     Revised Section <IP_ADDRESS> to clarify that Method 201A is not
applicable for stack diameters less than 26.5 inches when the combined
PM10/PM2.5 cyclone is used. The in-stack nozzle/
cyclones and filter assembly in stacks less than 26.5 inches in
diameter would cause significant cross-sectional area interference and
blockage, leading to incorrect flow calculation and particle size
separation.
     Revised Section 8.5.5 to express the maximum failure rate
of values outside the minimum-maximum velocity pressure range in terms
of percent of values outside the range instead of the number of
traverse points outside the range.
     Revised section 8.6.1 to clarify that alternative designs
are acceptable for fastening caps or covers to cyclones to avoid
galling of the cyclone component threads in hot stacks. The method may
be used at temperatures up to 1,000[deg]F using stainless steel
cyclones that are bolted together, rather than screwed together. Using
``break-away'' stainless steel bolts facilitates disassembly and
circumvents the problem of thread galling.
     Clarified sampling procedures in Section <IP_ADDRESS> to
maintain the temperature of the cyclone sampling head within  10 [deg]C of the stack temperature and to maintain flow until
after removing and before inserting the sampling head.
     Revised Section 11.2.7 to allow the use of tared
fluoropolymer beaker liners for the acetone field reagent blank.

B. Method 202

    Method 202 contains the following changes and clarifications:
     Clarified the terminology used to refer to laboratory and
field blanks throughout the method.
     For health and safety reasons, replaced the use of
methylene chloride with hexane throughout the method.
     Clarified Section 1.2 by moving the discussion of
filterable PM methods used in conjunction with Method 202 to Section
1.5.

     Clarified Section 1.6 to specify that Method 202 can be
used for measuring CPM in stacks that contain entrained moisture if the
sampling temperature is sufficiently high to keep the moisture in the
vapor phase.
     Moved the recommendation to develop a health and safety
plan from Section 9.4 to Section 5.0.
     Added amber glass bottles to the list of sample recovery
equipment in Section 6.2.
     Added alternatives (fluoropolymer beaker liners or
fluoropolymer baggies) to weighing tins to the list of analytical
equipment in Section 6.2.2 (Section 6.3 of the proposed method).
     Added specifications for sample drying equipment in
Section 6.2.2 (Section 6.3 of the proposed method).
     Clarified Section 6.3.7 regarding the use of an analytical
balance with sensitivity to 0.00001 g (0.01 milligram).
     Added an option to use a colorimetric pH indicator instead
of a pH meter in Section 6.2.2 (Section 6.3 of the proposed method).
     Added a sonication device to the list of analytical
equipment in Section 6.2.2 (Section 6.3 of the proposed method).
     Added performance-based, residual mass contribution
specifications for containers and wash bottles in Section 6.2.2
(Section 6.3 of the proposed method) rather than specifying the type of
container that must be used.
     Replaced the prescriptive language regarding filter
materials in Section 7.1.1 with performance-based requirements limiting
the residual mass contribution.
     Replaced the prescriptive language regarding water quality
in Section 7.1.3 with performance-based requirements for residual mass
content.
     Clarified Section 8.2 to specify that cleaned glassware
must be used at the start of each new source category tested at a
single facility.
     Added a performance-based option to Section 8.4 to conduct
a field train proof blank rather than meeting the glassware baking
requirements in Section 8.2.
     Clarified the sampling train configuration for the
nitrogen purge procedures in Section <IP_ADDRESS> regarding pressurized
purges.

C. How will the final 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
finalized 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. When implemented, the test method
revisions should 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 revised method could 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 revised 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 revised method 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 demonstrate facility
compliance.
    These amendments would serve to mitigate the potential difficulties
that can arise when EPA and other regulatory entities attempt to use
the test data from State and local agencies with inconsistent CPM test
methods 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 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 sulfur
trioxide, 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, lowest
achievable emission rate, or reasonably available control technology
limits have been based on an identified control technology, and that
the data used to determine the performance of that technology and to
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
that 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, after 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 should 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 previously promulgated test methods, it is not a
given that the permit would always have to be revised should these test
method 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 related to
emissions source permitting, due to these changes to the test methods,
would be determined based upon several factors such as the exact
wording of the existing operating permit, the requirements of the EPA-
approved SIP, and any changes that may need to be made to pre-
construction review permits with respect to CPM measurement (e.g.,
emissions estimates may be based upon a source test method that did not
measure CPM or upon a set of Method 202 procedures that underestimated
CPM 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. The transition period for CPM is the time
period during which the new rules and NSR permits issued to stationary
sources are not required to address the condensable fraction of the
sources' PM emissions. The end date of the transition period (January
1, 2011) was adopted in the final Clean Air Fine Particle
Implementation Rule (72 FR 20586, April 25, 2007) and in the final
Implementation of the New Source Review Program for Particulate Matter
Less Than 2.5 Micrometers (PM2.5) rule (73 FR 28321, May 16,
2008). As discussed in these two rules, the intent of the transition
period (which ends January 1, 2011) was to allow time for EPA to issue
a CPM test method through notice and comment rulemaking, and for
sources and States to collect additional total primary (filterable and
condensable) PM2.5 emissions data to improve emissions
information to the extent possible. 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'' (73 FR 28344). In the notice of proposed rulemaking for this
final rule on amendments to Method 201A and 202, EPA sought comment on
whether to end the NSR transition period for CPM early (74 FR 12976).
In this final rule, EPA is taking no action to affect the already
established January 1, 2011 sunset date for the NSR transition period.
    Source test data collected with the use of this updated test method
will be incorporated into the tools (e.g., emission factors, emission
inventories, air quality modeling) used to demonstrate the attainment
of air quality standards. Areas that are designated nonattainment for
the 1997 PM2.5 NAAQS, and that have approved attainment
dates of 2014 or 2015, are required to develop a mid-course review in
2011. If it is determined that additional control measures are needed
to ensure the area will be on track to attain the standard by the
attainment date, any new direct PM2.5 emission limits
adopted by the State must address the condensable fraction and the
filterable fraction of PM2.5. Additionally, the new test
data could be used to improve the applicability and performance
evaluations of various control technologies.

IV. Summary of Final Methods

A. Method 201A

    Method 201A measures PM emissions from stationary sources. The
amendments to Method 201A add a PM2.5 measurement device
(PM2.5 cyclone) that allows the method to measure filterable
PM2.5, filterable PM10, or both filterable
PM2.5 and filterable PM10. The method can also be
used to measure coarse particles (i.e., the difference between measured
PM10 concentration and the measured PM2.5
concentration).
    The amendments also add a PM2.5 cyclone to create a
sampling train that includes a total of two cyclones (one cyclone to
segregate particles with aerodynamic diameters greater than 10 [mu]m
and one cyclone to segregate particles with aerodynamic diameters
greater than 2.5 [mu]m) and a final filter to collect particles with
aerodynamic diameters less than or equal to 2.5 [mu]m. The
PM2.5 cyclone is inserted between the PM10
cyclone and the filter of the Method 201A sampling train.
    The revised method has several limitations. The method cannot be
used to measure emissions from stacks that have entrained moisture
droplets (e.g., from a wet scrubber stack) because size separation of
the water droplets is not representative of the dry particle size
released into the air. In addition, the method is not applicable for
stacks with diameters less than 25.7 inches when the combined
PM10/PM2.5 cyclone is used. Also, the method may
not be suitable for sources with stack gas temperatures exceeding 260
[deg]C (500 [deg]F) when cyclones with screw-together caps are used
because the threads of the cyclone components may gall or seize, thus
preventing the recovery of the collected PM. However, the method may be
used at temperatures up to 1,000 [deg]F when using stainless steel
cyclones that are bolted together rather than screwed together. Using
``break-away'' stainless steel bolts facilitates disassembly and
circumvents the problem of thread galling. The method may also be used
at temperatures up to 2,500 [deg]F when using specialty high-
temperature alloys.

B. Method 202

    Method 202 measures concentrations of CPM in stationary source
sample gas after the filterable PM has been removed using another test
method such as Method 5, 17, or 201A. The CPM sampling train begins at
the back half of the filterable PM filter holder and consists of a
condenser, two dry impingers (temperatures maintained to less than 30
[deg]C (85 [deg]F)), and a CPM filter (temperature maintained between
20 [deg]C (65 [deg]F) and 30 [deg]C (85 [deg]F)). During the test,
sample gases are cooled and CPM is collected in the dry impingers and
on the CPM filter. As soon as possible after the post-test leak check
has been conducted, any water collected in the dry impingers is purged
with nitrogen gas for at least one hour to remove dissolved
SO2 gas.
    After the nitrogen purge, the sampling train components downstream
of the filterable PM filter (i.e., the probe extension (if any),
condenser, impingers, front half of CPM filter holder, and the CPM
filter) are rinsed with water to recover the inorganic CPM. The water
rinse is followed by an acetone rinse and a hexane rinse to recover the
organic CPM. The CPM filter is extracted using water to recover the
inorganic components and hexane to recover the organic portion. The
inorganic and organic fractions are then dried and the residues
weighed. The sum of both fractions represents the total CPM collected
by Method 202.

V. Summary of Public Comments and Responses

    In response to the March 25, 2009 proposed revisions to EPA Methods
201A and 202, EPA received public

comment letters from industry representatives, trade associations,
State agencies, and environmental organizations. The public comments
submitted to EPA addressed the proposed revisions to Methods 201A and
202 and our request for comments on whether to end the transition
period for CPM in the NSR program on a date earlier than the current
end date of January 1, 2011.
    This section provides responses to the more significant public
comments received on the proposed revisions to Methods 201A and 202.
Summaries and responses for all comments related to the proposed
revisions to Methods 201A and 202, including those addressed in this
preamble, are contained in the response to comments document located in
the docket for this final action (Docket ID No. EPA-HQ-OAR-2008-0348).

A. Method 201A

1. Speciation
    Comment: One commenter stated that EPA should include guidance in
Method 201A concerning speciation of the constituents present in the
PM10, PM10-PM2.5, and PM2.5
size fractions. The commenter believes this information should be
provided to support the use of speciated PM10,
PM10-PM2.5, and PM2.5 data in source
apportionment studies.
    Response: EPA did not revise the method to provide guidance for
speciation of various particle fractions for source apportionment
because Method 201A is not a speciation method. However, with judicious
selection of filter media, sources may use this method for speciating
the less volatile metals and use these data in source apportionment
studies. Including details to adapt this method for speciation analysis
would unduly increase the complexity of the method without increasing
the precision of the mass measurements.
2. Catch Weight and Sampling Times
    Comment: Several commenters requested that EPA specify the minimum
solids catch weights needed in the PM10 and PM2.5
size fractions to help testing organizations determine the necessary
sampling times, especially for sources with low PM concentrations.
Other commenters expressed concern about extended sampling times that
would be necessary to obtain enough sample to weigh accurately. One
commenter stated that a reasonable limit must be put on sampling volume
to limit potentially unnecessary sampling time and exorbitant stack
testing costs that could quickly escalate with such a requirement.
    Response: We agree with the commenters that collecting sufficient
weighable mass is important for the method to be precise. We also
understand that the sampling rate used to attain the cyclone cut-points
is typically less than the rate used during Method 5 sampling. However,
EPA did not revise the method to dictate a minimum sampling volume or
minimum catch weight that would be necessary to obtain a valid sample.
One reason for not specifying a minimum sampling volume or minimum
catch weight is that different regulatory authorities and testing
programs have differing measurement goals. For example, some regulatory
authorities will accept less precision if results are well below
compliance limits. State agencies or individual regulated facilities
may develop data quality objectives (DQO) for the test program, which
may specify minimum detection limits, and/or minimum sample volume,
and/or catch weight that would demonstrate that DQO can be met. Stack
samplers should take into consideration the compliance limits set by
their regulatory authority and determine the minimum amount of stack
gas needed to show compliance if the mass of particulate is below the
detection limit.
    Stack testers can use the minimum detection limit to determine the
minimum stack gas volume. The stack tester may be able to estimate the
necessary stack gas volume based on how much PM the source or source
category is expected to emit (which could be determined from a previous
test or from knowledge of the emissions for that source category).
    Alternatively, the minimum detection limit for a source can be
determined by calculating the percent relative standard deviation for a
series of field train recovery blanks. You will not be able to measure
below the average train recovery blank level, and EPA recommends
calculating a tester-specific detection limit by multiplying the
standard deviation of field recovery train blanks by the appropriate
``Student's t value'' (e.g., for seven field train recovery blanks, the
standard deviation of the results would be multiplied by three). Short
of having Method 201A field recovery train blanks for cyclone and
filter components of the sampling train, you may use the detection
limit determined from EPA field tests.
    An estimated detection limit was determined from an EPA field
evaluation of proposed Method 201A (see ``Field Evaluation of an
Improved Method for Sampling and Analysis of Filterable and Condensable
PM,'' Docket ID No. EPA-HQ-OAR-2008-0348). The estimated detection
limit was calculated from the standard deviation of the differences
from 10 quadruplicate sampling runs multiplied by the appropriate
``Student's t value'' (n-1 = 9). Detection limits determined in this
manner were (1) Total filterable PM: 2.54 mg; (2) PM10: 1.44
mg; and (3) PM2.5: 1.35. These test runs showed more
filterable particulate in the PM2.5 fraction, and total
filterable particulate detection limits may be biased high due to the
small particulate mass collected in the fraction greater than
PM10.
    Comment: Two commenters questioned the use of reference methods to
correct for ambient air in Section 1.5 of the proposed Method 201A. One
commenter believed that the statement would be used as a means to blame
non-compliance on ambient contributions and would result in legal
challenges and disputes of test results. The other commenter questioned
whether it was the intent of EPA to not allow the use of the CPM test
method for low-temperature sources.
    Response: We agree with the commenters that Section 1.5 of the
proposed method was unclear. Thus, Section 1.5 (Additional Methods) has
been removed from the final method. For sources that have very low PM
emissions, such as processes that burn clean fuels (e.g., natural gas)
and/or use large volumes of dilution air (e.g., gas turbines and
thermal oxidizers), any ambient air particulate introduced into the
process operation could be a large component of total outlet PM
emissions. However, the decision to correct results for fine PM
measurements to account for ambient air contributions is up to the
permitting or regulatory authority. It is likely that these adjustments
would be limited to gas turbines and possibly sources fired with clean
natural gas.
    Comment: Commenters expressed concern about the lack of a test
method to measure PM2.5 in stacks with entrained moisture.
Another commenter urged EPA to continue work to identify or develop a
method for measuring filterable (or total) PM at sources with entrained
moisture droplets in the stack (e.g., units with wet stacks due to wet
flue gas desulfurization or wet scrubbers). Commenters requested that
EPA provide guidance or identify a viable alternative for high-moisture
stacks as soon as possible. One commenter stated that when conducting
emission testing at facilities with similar wet stack conditions as
described in the proposal preamble (74 FR 12973), that they support
EPA's position on the

limitations of the proposed Method 201A.
    One commenter was not satisfied with the use of Method 5 as the
only acceptable method for sources with entrained water droplets. To
provide more accurate emissions data for sources with ``wet'' stacks,
the commenter is sponsoring the development of an advanced manual
sampling technique that can accurately measure filterable
PM2.5 in stacks with entrained water droplets. The commenter
expects to complete field tests of this method in the near future. The
commenter will share laboratory and field test evaluations of this new
method. The commenter believes that this new method for filterable
PM2.5 emissions in ``wet'' stacks will be highly compatible
with proposed Method 201A for filterable PM2.5 emission
testing in ``dry'' stacks.
    Response: We are currently developing a method to measure PM in
stacks with saturated water vapors and laboratory testing is ongoing.
EPA has committed a significant budget and personnel to developing an
acceptable method for sources with wet stacks and we plan to offer the
method and protocol as soon as possible. EPA's method development and
evaluation is focused on the ``Dried Particle Method'' (See ``Lab Work
to Evaluate PM2.5 Collection with a Dilution Monitoring
Device for Data Gathering for Emission Factor Development (Final
Report)'' in Docket ID No. EPA-HQ-OAR-2008-0348) that directly measures
the mass emission rate of particles with specified aerodynamic size. In
the meantime, the promulgated amendments to Methods 201A and 202
improve their performance and reduce known artifacts. Testers should
use these final, amended methods until a PM2.5 method for
stack gases containing water droplets is promulgated.
    Regarding the advanced manual sampling technique that the commenter
is currently developing for use in ``wet'' stacks, EPA acknowledges the
sampling evaluations being conducted by the commenter. When the data
become available, we will review the data to determine if the
consistency and performance achieved by the advanced manual sampling
technique referenced by the commenter are comparable to EPA's wet-stack
sampling method currently under development. If the data are
comparable, we will consider whether the commenter's sampling technique
should be addressed (e.g., as an alternative method) when we propose an
EPA wet-stack, particle-sizing method in the future.
    Comment: Several commenters disagreed with EPA's recommendation to
use Method 5 on stacks with entrained moisture and to consider all the
collected mass to be PM2.5. Commenters stated that the
categorization of all PM measured by Method 5 as PM2.5
overstates the true emissions. One commenter supported EPA's
recommendation to use Method 5 to determine PM10/
PM2.5 filterable mass when measuring emissions following a
wet scrubber. Another commenter stated that when conducting emissions
testing at facilities with similar wet stack conditions, as described
in the proposal preamble (74 FR 12973), they supported EPA's position
on the limitations of the proposed Method 201A.
    Response: EPA acknowledges that using Method 5 on stacks with
entrained moisture and assuming that the catch is PM2.5 can
potentially overestimate PM2.5 concentrations. EPA Method 5
measures total PM mass emissions from stationary sources. Method 5 does
not specifically isolate PM10 or PM2.5. Method
17, similar to Method 5, measures total PM mass emissions, but it uses
an in-stack filter operating at stack temperature instead of a heated
probe and out-of-stack heated filter and thus, is suitable for only dry
sources.
    Monitoring the emission of PM10 or PM2.5 from
a wet gas stream is a challenging problem that has not been addressed
successfully despite considerable effort. A consensus method to provide
this information has not emerged. EPA has determined that particulate
from wet stacks is expected to be primarily PM10 under most
conditions typical of good wet scrubber design and operation.
University of North Carolina particle physicists performed theoretical
calculations based on a wet scrubber operating at 10,000 parts per
million by weight (ppmw) total dissolved solids (TDS) with water
droplets up to 50 [micro]m in size (see ``Development of Plans for
Monitoring Emissions of PM2.5 and PM10 from
Stationary Sources With Wet Stacks,'' Docket ID No. EPA-HQ-OAR-2008-
0348). They determined that water droplets under these conditions, when
dried, would generate particles of 10 [micro]m or less. Using the same
theoretical basis (i.e., the ratio of TDS to water droplet size), EPA
expects that water droplets up to 10 [micro]m in size would generate
dried particles of 2 [micro]m or less and that water droplets up to 20
[micro]m would generate dried particles up to 4 [micro]m or less.
    Based on wet scrubber operation and typical mist eliminator
performance, EPA has determined that the Method 5 filterable
particulate measurements are a satisfactory approximation of
PM2.5 filterable particulate from controlled wet stack
emissions. It is the States' or regulatory authorities' responsibility
to interpret EPA's recommendation to use Method 5 when measuring PM in
stacks containing water droplets and to consider all of the collected
material to be PM2.5.
    Because a completely acceptable method for measuring
PM2.5 in wet stacks is not currently available, EPA
understands the need to support the States with a PM2.5
method for wet stacks. EPA is currently developing this method and
laboratory testing is ongoing. EPA has committed a significant budget
and personnel to developing an acceptable method for sources with wet
stacks, as explained above. In the meantime, the promulgated amendments
to Methods 201A and 202 improve their performance and reduce known
artifacts. Testers should use these final, amended methods until a
PM2.5 method for wet stack conditions is promulgated.
    Comment: Several commenters expressed concern about the limitation
of the method for stack temperatures greater than 500 [deg]F. One
commenter asked that EPA investigate a possible modification to the
method to utilize sampling equipment that can withstand higher stack
temperatures. The commenter also introduced the possibility of moving
the particle sizing device, at least for PM2.5, out of the
stack and into a heated box, enabling use of a glass-lined probe for
sampling. Another commenter stated that the operator of a hot stack
should not be required to ``take extraordinary measures'' (such as
using the metal Inconel) when such measures are not defined in the
method, no less tested in the field for accuracy. The commenter
encouraged EPA to develop an acceptable substitute method for hot
stacks. As an alternative, the commenter recommended that Method 5
testing, in conjunction with AP-42 particle size distribution data
specific to glass furnaces, should be used for measurement of
PM2.5 in hot stacks.
    Response: EPA investigated additional alternatives to allow the use
of screwed together cyclones at elevated stack temperatures. As a
result of this investigation, EPA has revised Section 8.6.1 of Method
201A to allow the method to be used at temperatures up to 1,000 [deg]F
(538 [deg]C) using stainless steel cyclones that are bolted together,
rather than screwed together. Using ``break-away'' stainless steel
bolts facilitates disassembly and circumvents the problem of thread
galling. If the

stainless steel bolts seize, over-torquing such bolts causes them to
break at the bolt head, thus releasing the cyclones without damaging
the cyclone flanges (see ``Review of Draft EPA Test Methods 201A and
202 Related to the Use of High Temperature and Out-of-Stack Cyclone
Collection,'' Southern Research Institute, EPA Docket ID No. EPA-HQ-
OAR-2008-0348). The method can be used at temperatures up to 2,500
[deg]F using specially constructed high-temperature stainless steel
alloys (Hastelloy or Haynes 230) with bolt-together closures using
break-away bolts (see also ``Development of Particle Size Test Methods
for Sampling High Temperature and High Moisture Sources,'' California
Environmental Protection Agency, Air Resources Board Research Division,
1994, NTIS PB95-170221).
    Regarding the use of a heated box external to the stack to house
the cyclones, EPA disagrees with this approach because of the potential
for significant losses of particulate in the nozzle and probe liner.
EPA expects that transport losses for particles in the size range of
interest would be significant enough to materially affect the
measurement results. These losses would be caused by deposition
primarily by impaction in the sampling nozzle (at the flow rates used
in PM10 and PM2.5 sampling) and settling losses
in horizontal probes. (See ``Review of Draft EPA Test Methods 201A and
202 Related to the Use of High Temperature and Out-of-Stack Cyclone
Collection, Southern Research Institute,'' EPA Docket ID No. EPA-HQ-
OAR-2008-0348.)
    Sampling from ducts smaller than allowed by the blockage criteria
or from ducts at high temperatures presents challenges that should be
addressed by the source tester in conjunction with the regulatory
authority. Method 201A does not permit the use of a nozzle and probe
extension leading to an external heated oven to house the cyclones that
would otherwise block stack flow or operate at stack temperatures
beyond acceptable limits. Conventional screwed-together cyclones are
designed to operate in stacks that have a blockage of less than three
percent and have a temperature of less than 500 [deg]F.
    Regarding the use of AP-42 as a replacement for PM10 or
PM2.5 compliance testing, EPA has determined that this is
not appropriate because of the uncertainty in the data due to
variations in the particle sizing used to generate AP-42 emission
factors. EPA's AP-42 particle-sizing data for sources controlled by wet
scrubbers are based upon particle sizing methodologies that are
affected by the same influences and uncertainties that make particle
sizing in stacks with entrained water droplets a challenging technical
issue. Particle-sizing information in AP-42 is based primarily upon
data collected in the 1970s and early 1980s. The uncertainties
associated with methods used during this period of time result in
particle-sizing data that are dated and may not reflect the best
sampling technology or the emissions from current control devices.
Particle-sizing data from the 1970s employed many measurement
methodologies that were found to introduce indeterminate biases in the
particle sizing data. Also, source testers implemented measurement
methods in different ways to deal with particle-sizing methodology and
source-specific measurement challenges. The inconsistencies associated
with addressing measurement challenges and indeterminate biases led to
higher uncertainties associated with the measurement method results.
Therefore, AP-42 should not be used as a replacement for contemporary
emissions testing.
    However, it may be acceptable to allow limited application of AP-42
particle size distributions as screening assessments when the
underlying biases, uncertainties, and variations of the particle-sizing
are taken into consideration. For example, one simple method involves
using terms that include factors (such as the TDS of the recirculating
scrubber water, estimated water droplet size distribution of the exit
gas, and total liquid mass) that are already used to calculate
approximate emission factors. Instruments are commercially available
that can continuously monitor TDS and water flow rate, and the output
from these instruments could feed into an emission factor to provide a
continuous estimate of emissions that varies with process conditions.
However, work needs to be done to evaluate the reliability and bias of
this type of candidate estimation method. The required data inputs for
this type of estimation model need to be identified and the likelihood
that these inputs can be provided by the emission source needs to be
confirmed. Once the input data can be readily obtained, the estimation
model(s) needs to be evaluated to bring the most promising methods to
fruition. (See ``Development of Plans for Monitoring Emissions of
PM2.5 and PM10 from Stationary Sources with Wet
Stacks, Department of Environmental Sciences and Engineering,
University of North Carolina at Chapel Hill under subcontract to MACTEC
Federal Programs,'' EPA Contact No: EP-D-05-096, Work Assignment 2-05,
August 2007; Docket ID No. EPA-HQ-OAR-2008-0348).
    Comment: Several commenters requested changes to Section 6 of
Method 201A regarding equipment and supplies. One commenter questioned
the use of glass dishes and glass 250 ml beakers for drying the filter
and rinses in proposed Method 201A. Another commenter stated that, at a
minimum, the method should specify glass beakers, 50 ml weighing tins,
and an analytical balance with a resolution of 0.00001 g (0.01 mg). One
commenter recommended that polyethylene transfer/storage bottles should
be allowed to minimize the chance of breakage when in the field.
    Response: We revised Sections 6.2, 11.2.4, and 11.2.7 of Method
201A to allow the use of fluoropolymer beaker liners for evaporating
the particulate rinse solvent and the acetone field reagent blank,
desiccating particulate to constant weight, and weighing particulate
samples in the final evaporation step. We revised Section 6.2,
consistent with the commenter's suggestions, and added glass beakers
and an analytical balance with a resolution of 0.00001 g (0.01 mg) to
the sample recovery and analytical equipment list. However, we did not
include weighing tins because we determined that quantitative transfer
of particles in acetone from a beaker to a weighing tin is not
necessary and adds unnecessary imprecision to the final sample weight.
Alternatively, EPA has changed the method to allow fluoropolymer beaker
liners to be used to evaporate and weigh the samples.
    EPA revised Section 6.2.1 of Method 201A by defining sample
recovery items consistently with Method 5, except for wash bottles and
sample storage bottles. Any container material is acceptable for wash
bottles and storage bottles, but the container must not contribute more
than 0.05 mg of residual mass to the CPM measurements.
    Comment: Several commenters expressed concern about the proposed
requirement to use a 6-inch sampling port. One commenter pointed out
that using a 6-inch sampling port would be required only for the
combined PM10/PM2.5 sampling apparatus. Another
commenter stated that the physical dimensions of the cyclone would also
cause problems with installation in the generally small fryer and dryer
stacks. Another commenter noted that the partitioning of the filterable
solids using bulky, in-stack cyclones creates several logistical and
practical problems. The commenter

stated that the size of the in-stack separation cyclones requires 6-
inch to 8-inch sampling ports that do not exist at the vast majority of
stationary sources potentially affected by this final action.
    Response: EPA understands the commenters' concerns regarding
sampling port diameter requirements. However, facilities that are
required to use Method 201A are responsible for ensuring that the stack
has the appropriately sized sampling ports. The need for the larger
port diameter has not changed from the requirement as stated in the
1990 version of this method. We revised Section 8.3.1 of Method 201A to
more clearly describe when a 4-inch port may not accommodate the
PM10 particle-sizing cyclone and the nozzle that extends
from the cyclone and to highlight the need for a larger port in such
situations.
    Comment: One commenter requested that EPA adjust the allowable
number of traverse points that fall outside of the range of the
[Delta]pmin and [Delta]pmax for cases in which
more than the recommended maximum 12 traverse points are sampled by
Method 201A. Many agencies require that more than the recommended
maximum 12 traverse points be sampled if total filterable particulate
is being determined. The commenter requested that the number of allowed
out-of-range values be adjusted to match the stated failure rates
expressed as percentages.
    Response: EPA agrees that increasing the number of allowable
traverse points outside the range [Delta]pmin and
[Delta]pmax is appropriate when more than the recommended
number of traverse points are sampled. EPA has modified Section 8.5.5
of the method to allow 16 percent failure rate rounded to the nearest
whole number for PM2.5 only and 8 percent failure rate
rounded to the nearest whole number if the course fraction for
PM10 determination is included.
    Comment: One commenter requested that EPA add a new section in
Section 8.3.2 to address ducts with diameters less than 18 inches. The
commenter stated that the new section should state that ducts with
diameters less than 18 inches have blockage effects ranging from five
to ten percent. Therefore, according to the commenter, when a test is
conducted on these small ducts, the observed velocity pressures must be
adjusted for the estimated blockage factor whenever the combined
sampling apparatus blocks more than three percent of the stack or duct.
    For stacks smaller than 18 inches, one commenter asked if there
would still be a blockage issue even when following the proposed Method
201A procedures, especially as the stack diameter gets smaller. The
commenter also asked if there was a lower limit of stack diameter where
the method cannot be used.
    One commenter stated that when conducting emissions testing at
facilities with similar small stack (less than 18 inches in diameter)
conditions, as described in the proposal preamble (74 FR 12973), their
experience supported EPA's position on the limitations of the proposed
Method 201A. Another commenter pointed out an error in Section <IP_ADDRESS>
that implied that the method could be used on stacks with diameters
less than 18 inches.
    Another commenter requested that if testing of stacks less than 18
inches in diameter is still allowed and the testers are required to use
Method 1A, then the option of using a standard pitot tube should apply.
    Response: We revised Section <IP_ADDRESS> of Method 201A to clarify the
lower limits of stack diameter for different sampling configurations.
The combined PM10/PM2.5 filter sampling head and
pitot tube is not applicable for stacks with a diameter less than 26.5
inches because the blockage is greater than six percent. Blockage above
six percent is not allowed for the combined PM10/
PM2.5 filter sampling head and pitot tube. However,
measurements for only PM2.5 may be possible using only a
PM2.5 cyclone, pitot tube, and in-stack filter for stacks
with a diameter less than 26.5 inches. If the blockage exceeds three
percent but is less than six percent in that configuration, you must
follow the procedures outlined in Method 1A to conduct tests on stacks
less than 26.5 inches in diameter. In addition, you must conduct the
velocity traverse downstream of the sampling location or immediately
before the test run.
    We also modified Section 10.1 of the method to allow standard pitot
tubes to be used downstream when significant blockage exists. As stated
in Section <IP_ADDRESS>, you must adjust the observed velocity pressures for
the estimated blockage factor whenever the sampling apparatus blocks
three to six percent of the stack or duct.
    Comment: One commenter requested that the specification for the
maximum allowable acetone blank value be changed from 0.001 percent by
weight to either 1 ppmw or 0.0001 percent by weight to be consistent
with the reagent specification stated in Section 7.2.1 of the method.
    Response: We agree with the commenter that maximum allowable
acetone blank value should be consistent with the reagent specification
stated in Section 7.2.1. Thus, we revised Section <IP_ADDRESS> of the final
method to specify the maximum allowable acetone blank in terms of
weight per volume of acetone (0.1 mg per 100 ml solvent), rather than
percent weight.
    Comment: One commenter expressed concern about the approach in
Section <IP_ADDRESS> of the proposed method. The commenter stated that
subtracting the acetone blank mass from the individual sample masses
would be acceptable if the volumes of the acetone rinses are all
exactly 100 ml. However, according to the commenter, this was not
reality, and the accuracy of determining the blank correction suffers
from this approach. The commenter suggested that rather than
subtracting the mass of the acetone rinse blank dry residue directly
from the sample masses, the concentration of the acetone rinse blank
should be calculated as the mg of dry residue per ml of acetone rinse
blank volume limited to the concentration of residue at 1 ppmw. The
commenter stated that this concentration of the dry residue would be
multiplied by the volume of the acetone in ml used to collect and
recover each sample from the sampling head. The commenter stated that
the resulting mass would be subtracted from the dry residue mass
determined for the sample of interest. According to the commenter, this
approach will provide a more accurate determination of the dry residue
mass from the acetone rinse blank due to processing a larger volume of
acetone, and assessment of the blank mass correction for each sample as
it will be proportional to the amount of acetone used to collect each
sample. The commenter stated that the liquid volume of the samples and
blanks could be determined by either direct volumetric measurement or
by multiplying the wet weight of the sample or blank by the density of
the reagent at 20 [deg]C.
    Response: We agree with the commenter and with the commenter's
suggested equation. Therefore, we revised Section <IP_ADDRESS> of the final
method to accommodate different acetone rinse volumes. However, the
correction must be proportional to the amount of solvent used. Some
testers may use more solvent due to heavy deposits that are difficult
to remove, while other testers may use less solvent. Therefore, the
maximum adjustment is 0.1 mg per 100 ml of the acetone used from the
sample recovery.

B. Method 202

1. Extraction Solvent
    Comment: Three commenters noted that methylene chloride is highly
toxic. One commenter stated the use of

methylene chloride poses significant exposure risks to field test
personnel, plant personnel working in the area of the mobile
laboratory, and agency test observers. Two commenters stated that
Method 202 should specify a less toxic solvent than methylene chloride,
such as n-hexane.
    One commenter stated that EPA should sponsor a set of tests to
confirm that n-hexane or another less-toxic solvent provides the sample
rinse effectiveness as methylene chloride. Another commenter encouraged
EPA to conduct future studies to identify a solvent to replace
methylene chloride in Proposed Method 202 and in other EPA reference
methods.
    Another commenter stated that the use of methylene chloride (a
known carcinogen) as the cleaning and recovery solvent will require
safety departments to develop procedures for appropriate handling on-
site and the use of personal protection equipment for personnel that
may be exposed to the solvent. The commenter noted that toluene, which
is used in EPA Method 23, is a technically acceptable alternative to
methylene chloride. The commenter suggested that EPA review the use of
toluene as a replacement for methylene chloride in Method 202 (and OTM
028).
    Response: The extraction solvent specified in a particular test
method is dependent on the analyte(s) of interest. If the target
analyte is known, an appropriate solvent can be identified that has the
desired recovery performance for that analyte. For Method 202, the
pollutant measured by the method, CPM, is defined by the method (i.e.,
whatever remains after the sample recovery procedures is considered to
be CPM regardless of its analyte group). Although no single solvent is
universally applicable to all analyte groups, methylene chloride was
chosen for the proposed method based upon studies (``IERL-RTP
Procedures Manual, Level 1, Environmental Assessment''; EPA-600/2-76-
160a; June 1976) that showed it was the optimum solvent to recover
polar and non-polar CPM.
    We acknowledge the commenters' concerns regarding the toxicity of
methylene chloride and the exposure hazards associated with its use,
and we agree that the use of an alternative solvent is justified.
However, because the recovery performance of solvents has been
previously evaluated to support various EPA programs, we disagree with
the commenters that additional studies are necessary to identify a
suitable alternative solvent.
    In identifying an alternative solvent, we initially considered
specifying toluene because its extraction performance for non-polar
compounds is similar to methylene chloride. However, because the vapor
pressure of toluene is lower than methylene chloride, additional time
would be needed to evaporate the organic samples to dryness at room
temperature (30[deg]C or less). Because the additional evaporation time
would be an additional burden on testing contractors and present the
risk of losing condensable organic compounds, we rejected toluene as
the replacement solvent.
    We also evaluated the solvents used for organic compound recovery
in the analytical methods developed by EPA's Office of Solid Waste
(http://www.epa.gov/epawaste/hazard/testmethods/sw846/online/3_series.htm). We reviewed EPA's ``Test Methods for Evaluating Solid
Waste, Physical/Chemical Methods'' (SW-846), which was developed to
support the Resource Conservation and Recovery Act (RCRA) program, to
identify test methods that covered the same types of compounds expected
to comprise CPM. Based upon our review of SW-846, we identified Method
M-3550c (Ultrasonic Extraction) as a comparable method (M-3550c is used
to extract semi-volatile organic compounds from waste samples). Section
7.4 of M-3550c, which discusses extraction solvents, lists the
following extraction solvents by class of compound:
     Acetone/hexane or acetone/methylene chloride can be used
to extract semivolatile organics.
     Acetone/hexane or acetone/methylene chloride can be used
to extract organochlorine pesticides.
     Acetone/hexane, acetone/methylene chloride, or hexane can
be used to extract polychlorinated biphenyls (PCB).
    Of the above compound classes, the class that most closely relates
to the type of high-molecular weight hydrocarbons expected to comprise
organic CPM is PCB. Hexane is also listed as an alternative solvent
(when used in combination with acetone) for the other compounds classes
discussed in Section 7.4. Consequently, based upon this analysis, we
have replaced methylene chloride with hexane in the final method.
2. Sample and Blank Containers
    Comment: One commenter recommended that EPA revise the proposed
method to specify the container type for each container (i.e., glass or
plastic), and also whether the lid should have a Teflon[supreg] liner
or whether another liner is acceptable.
    Response: We disagree with the commenter that the method should
specify the material of construction of containers used for sample and
blank recovery procedures. Although we believe that the most
appropriate containers are constructed of glass and equipped with a
fluoropolymer lid, we also believe that testing contractors should have
the flexibility to select the type of containers that meet the
performance specifications of the method. Therefore, we have revised
the proposed method to add a performance-based specification for
containers. Section 6.2.2 of the final method specifies that the
containers used for sample and blank recovery procedures must not
contribute more than 0.05 mg of residual mass to the CPM measurements.
    Accompanying edits were also made to the CPM container language in
Section 8.5.4 (Sample Recovery).
3. CPM Filter
    Comment: One commenter suggested that the language in Section 7.1.1
of the proposed method be revised to replace the term ``Filter'' with
``CPM Filter'' and replace ``Teflon[supreg]'' with ``Teflon[supreg],
fluoropolymer or chemically equivalent.'' Another commenter stated that
the final method should allow for alternatives to Teflon[supreg]
filters, such as quartz, polytetrafluoropolymer (PTFE) coated, or PTFE
filters.
    Response: Based upon the comments received regarding the CPM
filter, we revised the language in Section 7.1.1 to include
performance-based specifications for the CPM filter rather than
specifying a particular type of filter. Section 7.1.1 of the final
method specifies that the CPM filter must be a non-reactive, non-
disintegrating filter that does not contribute more than 0.5 mg of
residual mass to the CPM measurements. The CPM filter must have an
efficiency of at least 99.95 percent (less than 0.05 percent
penetration) on 0.3 [mu]m particles. Documentation of the CPM filter's
efficiency is based upon test data from the supplier's quality control
program.
    In selecting the appropriate CPM filter, testing contractors should
avoid the mistake of equating the dioctyl phthalate size for the test
particles to the pore size for the filter. Filters with pore sizes
larger than the test particles can retain a high percentage of very
small particles. In our evaluation of different types of filters, we
determined that filter sizes of 47 mm are marginal, if not
unacceptable, for use. Additionally, we believe that hydrophobic
filters should be used to avoid absorption of water onto the CPM
filter.

4. Water Specifications
    Comment: Two commenters suggested that the final method specify the
level of residue allowed for the water used to clean glassware and
recovery samples, as was specified for acetone and methylene chloride.
One commenter stated that the maximum percent residue by weight of the
water should be specified to be consistent with the reagent
specifications for acetone and methylene chloride. Three commenters
noted that a residual mass level is not available for ASTM
International D1193-06, Type I water.
    Response: The purpose of the field reagent blanks is to provide a
testing contractor with information to target corrective actions, if
necessary, if they have difficulty in meeting the residual mass
allowance in the method. The method does not require analysis of field
reagent blank samples, and the field reagent blank values are not used
in correcting CPM measurements. However, we acknowledge that Figure 3
could be misleading with regard to the field reagent blanks, and we
have revised Figure 3 of the final method to remove the entries for the
field reagents.
    We acknowledge that the residue level is not specified for ASTM
International D1193-06, Type I water, and we agree with the commenters
that the method should specify a residual mass level for water used to
prepare glassware and recover samples. Therefore, we have revised
Sections 7.1.3 and 7.2.3 of the final method to specify that glassware
preparation and sampling recovery must be conducted using deionized,
ultra-filtered water that meets a residual blank value of 1 ppmw or
less. We have also made accompanying changes to water specified in
Sections 8.4, <IP_ADDRESS>, and <IP_ADDRESS> of the final method. We believe
that this performance specification will provide flexibility to testing
contractors in obtaining deionized, ultra-filtered water (e.g., water
could be purchased with a vendor guarantee or the contractor could
evaluate water they produce by evaporation and weighing of the
residue).
5. Glassware Baking Requirements
    Comment: Several commenters stated that the proposed requirement in
Section 8.4 to bake glassware at 300[deg]C for six hours was excessive.
Several commenters stated that they had conducted experimental tests
that showed that a lower baking temperature (e.g., 125[deg]C for three
hours) was sufficient to achieve the blank allowance specified in the
method. One commenter stated that, based upon their experiments, no
benefit was obtained from baking glassware. Another commenter stated
that they had conducted numerous test runs on non-combustion sources
without baking glassware and had achieved acceptable blank results. The
commenter noted that there might be some emission sources where baking
of glassware could be needed to meet the blank requirements, but the
commenter stated that the mandatory baking requirements did not seem to
be necessary for all sources. Another commenter stated that there is no
laboratory data to determine if a lower temperature could be sufficient
to achieve low background masses. Based upon experimental results, the
commenter suggested allowing the use of baking of glassware at
125[deg]C for three hours.
    One commenter stated that, because the presence of silicone grease
on impinger surfaces is highly unlikely due to the prevalence of O-
rings, baking the glassware at 125[deg]C for three hours after cleaning
is adequate. The commenter added that the baking requirements should be
revised because high-temperature baking would destroy or deteriorate
the O-rings typically used to seal impinger components. The commenter
stated that the effort to remove these O-rings before baking and then
replace them after baking is time-consuming. Several commenters noted
that the high-temperature baking requirements would be overly expensive
(e.g., for large, high-temperature ovens) and time-consuming.
    Another commenter stated that the requirement for glassware baking
only prior to the test makes little sense. The commenter questioned why
the glassware could not be rinsed with the recovery solvents as is done
between runs. The commenter noted that the proposed method mandates a
reagent blank and questioned why the reagent blank could not be changed
to a proof blank with a limit.
    One commenter stated that the requirement to bake glassware at 300
[deg]C for six hours should be optional because it has not been
possible to fully evaluate the supporting data and the need for such
high temperature is not readily apparent for all situations. The
commenter noted that the ``Draft Project Report--Evaluation and
Improvement of Condensable Particulate Measurement'' may contain this
information and recommended that the effect of pre-bake temperature and
time on cleanliness of blanks be clearly presented in this report and
include a table comparing the effect of 300 [deg]C for six hours versus
lower glassware preparation temperatures. Otherwise, according to the
commenter, this requirement would require the stack tester to bring to
the testing site a large amount of pre-cleaned glassware, much more
than what is currently normal for such testing.
    One commenter suggested that testing contractors be allowed to meet
the blank level specified in the method however they can. The commenter
stated that the prescriptive temperature requirement, particularly in
light of the fact that there are no data showing that the 2 mg blank
cannot be achieved at lower temperatures or through other means, did
not serve a purpose. Another commenter recommended that the tester
start with baked glassware for the first test and then be allowed to
perform additional tests reusing the same glassware after it has been
cleaned by chemical methods. If the chemical cleaning of the glassware
is not adequate, the commenter noted that blank values would likely
elevate, possibly eliminating the test from consideration. If the
blanks do not elevate, the commenter stated that this scenario would be
very cost-effective and would conserve resources.
    Response: Method 202 has the potential to measure CPM at very low
levels. Consequently, the glassware used in the sampling train must be
free from contamination to maximize the precision and accuracy of the
CPM measurements. The glassware cleaning requirements contained in the
proposed revisions to Method 202 were based upon experimental results
that indicated that the allowable blank correction of the method could
not be achieved without thorough cleaning and baking of the glassware
at 300 [deg]C for six hours.
    Based upon our review of the public comments received regarding the
baking requirements, we have determined that it is appropriate to
provide a performance-based option in Section 8.4 for demonstrating the
cleanliness of glassware used during the emission test. The option
provides testing contractors with flexibility when preparing glassware
while maintaining the cleanliness requirements of the method.
    As an alternative to baking glassware, the final method allows
testing contractors to perform a proof blank of the sampling train.
Field train proof blanks are recovered on-site from a clean, fully
assembled sampling train prior to the first emissions test and provide
the best indication of the lowest residual mass achievable by the
tester. Field train recovery blanks are recovered from a sampling train
after it has been used to collect emissions samples and has been rinsed
in

preparation for the second or third test in a series at a particular
source. Use of field train recovery blanks allows the tester to account
for and manage additional uncertainty that may be attributed to the
tester's ability to clean the sampling train between test runs in the
field.
6. Nitrogen Purge
    Comment: Three commenters requested that the nitrogen purge
procedures specified in Section 8.5 of the proposed method be revised
to allow for the dry gas meter to be disconnected from the sampling
train before the nitrogen purge is be conducted. Two commenters stated
that EPA should eliminate the portion of Figure 2 that shows the meter
box and revise the text in the proposed Method 202 to require purging
in a clean environment without the need for a meter box. Three
commenters added that allowing the dry gas meter to be disconnected
from the sampling train would decrease the delay between tests (i.e.,
the dry gas meter could be used with a new sampling train while the
purge is being conducted on the previous train). Three commenters also
stated that requiring the dry gas meter to be connected to the sampling
train during the purge will force testing contractors to bring extra
equipment (e.g., sampling trains, dry gas meters) to the sampling site.
    Three commenters suggested that the purge should be conducted at
the sample recovery location (e.g., mobile laboratory) rather than at
the actual sampling location (e.g., roof, stack sampling platform). Two
commenters noted that it is not practical to haul nitrogen cylinders to
the sampling location. One commenter suggested that, after the final
leak check, the open ends of the impinger train could be capped during
transport to the sample recovery area to reduce the possibility of
oxygen contamination. The commenter noted that the sample would not be
exposed to any more air than when immediately connecting to the
nitrogen purge line.
    Several commenters suggested that the proposed method be revised to
allow testing contractors to conduct a positive-pressure purge instead
of a negative-pressure purge using the dry gas meter. One commenter
suggested that the purge gas flow rate be monitored by a rotameter
instead of using the dry gas meter. The commenter noted that the flow
rate is better regulated upstream of the impingers rather than
downstream by the dry gas meter and using the rotameter to regulate the
purge gas flow rate would reduce the potential for pressurizing the
sampling train. Another commenter expressed concerns that if the vacuum
drawn by the dry gas meter does not match the pressure from the
nitrogen tank, then the impingers could become over-pressurized which
could compromise the integrity of the sampling train components.
    One commenter recommended that the proposed testing protocol be
modified to allow the tester to disassemble the impinger train to
measure for moisture content prior to conducting the required nitrogen
purge. One commenter noted that weighing the impingers prior to the
nitrogen purge would provide a more accurate moisture catch
determination and the need to measure the amount of degassed deionized
water that is added (if any) would be eliminated. Three commenters
added that, if the moisture content of the impingers is determined
before the nitrogen purge, then testing contractors should be allowed
to purge only the knock-out impinger, backup impinger, CPM filter, and
first moisture trap impinger. One commenter stated that if the sampling
train is purged by pushing nitrogen through the sampling train (i.e.,
positive pressure purge), then the sampling train components after the
CPM filter thermocouple could be disconnected from the train before
beginning the purge. One commenter suggested that the purge be
conducted through a Teflon[supreg] tube inserted through a stopper into
the impinger arm and then into the liquid to avoid compounding errors
associated with adding water to the first impinger (if needed). The
commenter stated that this would alleviate the need to break the
fitting or add water, and prevent the potentially compounding error of
water addition. Another commenter requested that a Teflon[supreg] line
be inserted down and through the short-stem impinger extending below
the water level in the impinger catch. The commenter stated that this
would reduce the potential for breaking glassware and contamination
when removing/inserting glassware stems.
    Three commenters suggested that the nitrogen purge requirements be
revised to allow for any liquid collected in the first (drop-out)
impinger to be transferred to the second (backup) impinger. The
commenters noted that this approach would decrease the potential for
contamination because a new piece of glassware (the long-stem impinger)
would not be introduced into the sampling train. One commenter
recommended that, after the liquid is transferred to the second
impinger, the first impinger should be removed from the sampling train
prior to the purge.
    Response: It was our intent in the proposed Method 202 to allow
testing contractors the option of conducting either a pressurized purge
(i.e., without the dry gas meter box and pump attached to the sampling
train) or a vacuum purge (i.e., with the dry gas meter box attached to
the sampling train). However, we acknowledge that the language in
Section 8.5.3 and the sampling train depicted in Figure 2 of the
proposed method were unclear. Consequently, we have revised Section
8.5.3 and Figure 2 and added Figure 3 to the final method to clarify
that a pressurized purge is an acceptable alternative.
    With regard to the commenters' suggestion to allow testing
contractors to conduct the nitrogen purge at the sample recovery
location instead of at the sampling location, we continue to believe
that testing contractors should have the flexibility to conduct the
nitrogen purge at the location of their choosing; therefore, the final
method does not specify where the purge must be conducted. However,
testing contractors should conduct the purge as soon as practicable
after the post-test leak check to reduce the potential for artifact
formation in the impinger water.
    With regard to the alternative sampling train configuration for the
purge, we agree with the commenters that testing contractors should be
allowed the option of determining the amount of moisture collected
prior to conducting the nitrogen purge, transferring any water
collected prior to the CPM filter to the second impinger, and
performing the nitrogen purge on the second impinger and the CPM filter
only. Therefore, Section <IP_ADDRESS> of the final method contains an
alternative purge procedure.
    We disagree with the commenter's suggestion to insert a
Teflon[supreg] tube into the first impinger for conducting the nitrogen
purge. Using the configuration suggested by the commenters, there is no
provision to maintain the temperature of the purge gas. Consequently,
we believe that a Teflon[supreg] or other inert line used to purge the
CPM train is not an acceptable alternative. Therefore, we are not
revising Section <IP_ADDRESS> to allow the use of a Teflon[supreg] tube.

C. Conditional Test Method 039 (Dilution Method)

    Comment: Several commenters urged EPA to continue the development
of dilution-based test methods for measuring PM2.5. One
commenter supported EPA's work through the stakeholder process to
decrease and eliminate other pollutant interferences

that can affect the accurate measurement of emissions of fine
particles, particularly for wet stacks and high volume/low
concentration gas streams. Another commenter encouraged EPA to use the
stakeholder process, similar to that used for Methods 201A and 202, to
move towards the promulgation of dilution methods and other test
methods that can better measure emissions from high-temperature and
high-moisture sources.
    One commenter asserted that dilution methods more correctly
simulate the atmospheric process leading to the formation and
deposition of PM in the atmosphere. Another commenter expected that
EPA's evaluation of an air dilution method would show that it is even
more useful in accurately measuring direct PM2.5 filterable
and condensable data for high temperature sources than the revised
Methods 201A and 202.
    Response: EPA continues to evaluate the precision and bias of
PM2.5 collected using dilution methods. In addition to EPA's
hardware design, several other hardware designs have been proposed that
utilize dilution. While limited evaluations of EPA's hardware design
have been performed, the other hardware designs proposed have more
limited evaluations. The consensus standards body, ASTM International,
has embarked on preparation of a standard method for dilution sampling
of particulate material. We will continue to evaluate dilution method
procedures and support the efforts of the ASTM International in their
development of a standard dilution-based test method for sampling PM.
In addition to these development efforts, several other factors
influence EPA's decision to delay proposing a dilution based sampling
method. One factor is that there is no widely accepted dilution method
available at this time. Another factor is that the available dilution
sampling hardware configurations share few of the equipment used by any
of the existing sampling methods. As a result, testing contractors
would be required to invest in this new equipment. This capital
investment would require a higher charge for testing than for the
existing methods. In addition, since dilution sampling is somewhat more
complex, contractors are likely to initially charge a premium for this
more complex testing. Lastly, the availability of hardware and
experienced individuals to perform dilution sampling is extremely
limited. EPA recognizes that there are limited applications where
dilution sampling provides advantages over the standard test methods.
As a result, we encourage sources that encounter these situations to
request that the regulatory authority that established the requirement
to use this method to approve the use of dilution sampling as an
alternative to the test method specified for determining compliance.
    Comment: One commenter maintained that use of a test method to
define what constitutes CPM for all sources is neither necessary, nor
(in some cases) useful. For sources, like coal-fired boilers, where the
only true condensable sulfate specie from coal combustion is sulfuric
acid, the commenter stated that CPM could be better quantified by
direct measurement using the Controlled Condensation Method (CCM). The
commenter said that States should be allowed and, in the case of units
with wet scrubbers, encouraged to use such direct measurements like CCM
to quantify known CPM instead of using Method 202. According to the
commenter, if the use of CCM is not allowed, Method 202 should include
a procedure that allows sources to correct Method 202 results using
results from simultaneous CCM test runs. In this procedure, according
to the commenter, the source would be subtracting out essentially the
same units of sulfate from Method 202 as would be added back in from
the CCM results. If, on the other hand, sulfate artifacts do exist, the
commenter said that the source would be subtracting ``x'' units of
sulfate from Method 202 and adding back ``y'' units of sulfate from CCM
to get an accurate measurement.
    Response: While SO3 may be the most abundant CPM emitted
from coal fired combustion, there is indication that other compounds
comprise CPM. Few speciation tests of coal and oil combustion have been
preformed, but those that have indicate the presence of not only
sulfate but also chloride, nitrate, ammonium ion, and a range of
inorganic elements that are potentially components for CPM (including
phosphorous, arsenic, and selenium). In addition, speciation tests have
been able to identify components representing only about 60 percent of
the mass. Therefore, the specific correction for sulfuric acid from
coal combustion source emissions proposed by the commenter would add to
the complexity of the method for all source categories while providing
an advantage to only one specific source category.
    EPA continues to review methods that involve controlled
condensation for sulfuric acid. Because no standard method is available
for controlled condensate measurement of sulfuric acid, we have
determined that providing additional guidance or correction of Method
202 results is premature. EPA is following current efforts by ASTM
International to develop a standard controlled condensate method for
sulfuric acid. In the meantime, testers and facilities should petition
their regulatory authority to approve alternative data treatment for
specific sources.

VI. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    This action is not a ``significant regulatory action'' under the
terms of Executive Order (EO) 12866 (58 FR 51735, October 4, 1993) and
is, therefore, not subject to review under the EO.

B. Paperwork Reduction Act

    This 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 final amendments do not
contain any reporting or recordkeeping requirements. The final
amendments revise two existing source test methods to allow one method
to perform additional particle sizing at 2.5 [mu]m 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 final rule on small
entities, I certify that this action will not have a significant
economic impact on

a substantial number of small entities. This final rule will not impose
any requirements 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 final action will not have a significant economic
impact on a substantial number of small entities, EPA nonetheless has
tried to reduce the impact of this final action on small entities. This
final rule does not require any entities to use these final test
methods. Such a requirement would be mandated by a separate independent
regulatory action. However, upon promulgation of this final action,
some entities may be required to use these test methods as a result of
existing permits or regulations. Since the cost to use the final 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 final test methods. 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 final action to modify the existing test
methods. Consequently, we believe that this final action imposes little
if any adverse economic impact to small entities.

D. Unfunded Mandates Reform Act

    This rule contains no federal mandates under the provisions of
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), 2 U.S.C.
1531-1538 for State, local, and tribal governments or the private
sector. The incremental costs associated with conducting the revised
test methods (expected to be less than $1,000 per test) do not impose a
significant burden on sources. Thus, this final action is not subject
to the requirements of sections 202 and 205 of the UMRA.
    This rule is also not subject to the requirements of section 203 of
UMRA because it contains no regulatory requirements that might
significantly or uniquely affect small governments. The low incremental
cost associated with the revised test methods mitigates any significant
or unique effects on small governments.

E. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have
substantial direct effects on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government, as
specified in Executive Order 13132. In cases where a source of
PM2.5 emissions is owned by a State or local government,
those governments may incur minimal compliance costs associated with
conducting tests to quantify PM2.5 emissions using the
revised methods when they are promulgated. However, such tests would be
conducted at the discretion of the State or local government and the
compliance costs are not expected to impose a significant burden on
those governments. Additionally, the decision to review or modify
existing operating permits to reflect the CPM measurement capabilities
of the final test methods is at the discretion of State and local
governments and any effects or costs arising from such actions are not
required by this rule. Thus, Executive Order 13132 does not apply to
this action.

F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments

    This action does not have tribal implications, as specified in
Executive Order 13175 (65 FR 67249, November 9, 2000). In cases where a
source of PM2.5 emissions is owned by a tribal government,
those governments may incur minimal compliance costs associated with
conducting tests to quantify PM2.5 emissions using the
revised methods when they are promulgated. However, such tests would be
conducted at the discretion of the tribal government and the compliance
costs are not expected to impose a significant burden on those
governments. Thus, Executive Order 13175 does not apply to this action.

G. Executive Order 13045: Protection of Children From Environmental
Health and Safety Risks

    EPA interprets Executive Order 13045 (62 FR 19885, April 23, 1997)
as applying only to those regulatory actions that concern health or
safety risks, such that the analysis required under section 5-501 of
the Executive Order has the potential to influence the regulation. This
action is not subject to Executive Order 13045 because it does not
establish an environmental standard intended to mitigate health or
safety risks.

H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use

    This action is not subject to Executive Order 13211 (66 FR 28355,
May 22, 2001) because it is not a significant regulatory action under
Executive Order 12866.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (NTTAA), Public Law 104-113, 12(d) (15 U.S.C. 272 note)
directs EPA to use voluntary consensus standards in its regulatory
activities unless to do so would be inconsistent with applicable law or
otherwise impractical. Voluntary consensus standards are technical
standards (e.g., materials specifications, test methods, sampling
procedures, and business practices) that are developed or adopted by
voluntary consensus standards bodies. NTTAA directs EPA to provide
Congress, through OMB, explanations when the Agency decides not to use
available and applicable voluntary consensus standards.
    This action involves technical standards. EPA has decided to use
two voluntary consensus standards that were identified at proposal to
be applicable for use within the amended test methods. The first
voluntary consensus standard cited in proposed Method 202 was ASTM
International Method D2986-95a (1999), ``Standard Method for Evaluation
of Air, Assay Media by the Monodisperse DOP (Dioctyl Phthalate) Smoke
Test,'' for its procedures to conduct filter efficiency tests. In the
final Method 202, we replaced the prescriptive requirement to use a
filter meeting ASTM International D2986-95a (1999) with a performance-
based requirement limiting the residual mass contribution. The
performance based approach specifies that the CPM filter must be a non-
reactive, non-disintegrating filter that does not contribute more than
0.5 mg of residual mass to the CPM measurements. Regarding efficiency,
the CPM filter must have an efficiency of at least 99.95 percent (<
0.05 percent penetration) on 0.3 [mu]m particles.
    The second voluntary consensus standard cited in proposed Method
202 was ASTM International D1193-06, ``Standard Specification for
Reagent Water,'' for the proper selection of distilled ultra-filtered
water. In response to public comments, we applied a

performance-based approach in the final Method 202 that requires
deionized, ultra-filtered water that contains 1.0 ppmw (1 mg/L)
residual mass or less.

J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898 (59 FR 7629, February 16, 1994) establishes
federal executive policy on environmental justice. Its main provision
directs federal agencies, to the greatest extent practicable and
permitted by law, to make environmental justice part of their mission
by identifying and addressing, as appropriate, disproportionately high
and adverse human health or environmental effects of their programs,
policies, and activities on minority populations and low-income
populations in the United States.
    EPA has determined that this final rule will not have
disproportionately high and adverse human health or environmental
effects on minority or low-income populations because it increases the
level of environmental protection for all affected populations without
having any disproportionately high and adverse human health or
environmental effects on any population, including any minority or low-
income population. The final amendments revise existing test methods to
improve the accuracies of the measurements that are expected to improve
environmental quality and reduce health risks for areas that may be
designated as nonattainment.

K. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. Section 808 allows the issuing agency to make a rule
effective sooner than otherwise provided by the CRA if the agency makes
a good cause finding that notice and public procedure is impracticable,
unnecessary or contrary to the public interest. This determination must
be supported by a brief statement. 5 U.S.C. 808(2). As stated
previously, EPA has made such a good cause finding, including the
reasons therefore, and established an effective date of January 1, 2011
(see section I.C, supra). EPA will submit a report containing this rule
and other required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. This action is not
a ``major rule'' as defined by 5 U.S.C. 804(2).

List of Subjects in 40 CFR Part 51

    Administrative practice and procedure, Air pollution control,
Carbon monoxide, Intergovernmental relations, Lead, Nitrogen oxide,
Ozone, PM, Reporting and recordkeeping requirements, Sulfur compounds,
Volatile organic compounds.

    Dated: December 1, 2010.
Lisa P. Jackson,
Administrator.

0
For the reasons stated in the preamble, title 40, chapter I of the Code
of Federal Regulations is amended as follows:

PART 51--[AMENDED]

0
1. The authority citation for part 51 continues to read as follows:

    Authority: 23 U.S.C. 101; 42 U.S.C 7401-7671q.

0
2. Amend appendix M by revising Methods 201A and 202 to read as
follows:

Appendix M to Part 51--Recommended Test Methods for State
Implementation Plans

* * * * *

METHOD 201A--DETERMINATION OF PM10 AND PM2.5
EMISSIONS FROM STATIONARY SOURCES (Constant Sampling Rate Procedure)

1.0 Scope and Applicability

    1.1 Scope. The U.S. Environmental Protection Agency (U.S. EPA or
``we'') developed this method to describe the procedures that the
stack tester (``you'') must follow to measure filterable particulate
matter (PM) emissions equal to or less than a nominal aerodynamic
diameter of 10 micrometers (PM10) and 2.5 micrometers
(PM2.5). This method can be used to measure coarse
particles (i.e., the difference between the measured PM10
concentration and the measured PM2.5 concentration).
    1.2 Applicability. This method addresses the equipment,
preparation, and analysis necessary to measure filterable PM. You
can use this method to measure filterable PM from stationary sources
only. Filterable PM is collected in stack with this method (i.e.,
the method measures materials that are solid or liquid at stack
conditions). If the gas filtration temperature exceeds 30 [deg]C (85
[deg]F), then you may use the procedures in this method to measure
only filterable PM (material that does not pass through a filter or
a cyclone/filter combination). If the gas filtration temperature
exceeds 30 [deg]C (85 [deg]F), and you must measure both the
filterable and condensable (material that condenses after passing
through a filter) components of total primary (direct) PM emissions
to the atmosphere, then you must combine the procedures in this
method with the procedures in Method 202 of appendix M to this part
for measuring condensable PM. However, if the gas filtration
temperature never exceeds 30 [deg]C (85 [deg]F), then use of Method
202 of appendix M to this part is not required to measure total
primary PM.
    1.3 Responsibility. You are responsible for obtaining the
equipment and supplies you will need to use this method. You must
also develop your own procedures for following this method and any
additional procedures to ensure accurate sampling and analytical
measurements.
    1.4 Additional Methods. To obtain results, you must have a
thorough knowledge of the following test methods found in appendices
A-1 through A-3 of 40 CFR part 60:
    (a) Method 1--Sample and velocity traverses for stationary
sources.
    (b) Method 2--Determination of stack gas velocity and volumetric
flow rate (Type S pitot tube).
    (c) Method 3--Gas analysis for the determination of dry
molecular weight.
    (d) Method 4--Determination of moisture content in stack gases.
    (e) Method 5--Determination of particulate matter emissions from
stationary sources.
    1.5 Limitations. You cannot use this method to measure emissions
in which water droplets are present because the size separation of
the water droplets may not be representative of the dry particle
size released into the air. To measure filterable PM10
and PM2.5 in emissions where water droplets are known to
exist, we recommend that you use Method 5 of appendix A-3 to part
60. Because of the temperature limit of the O-rings used in this
sampling train, you must follow the procedures in Section 8.6.1 to
test emissions from stack gas temperatures exceeding 205 [deg]C (400
[deg]F).
    1.6 Conditions. You can use this method to obtain particle
sizing at 10 micrometers and or 2.5 micrometers if you sample within
80 and 120 percent of isokinetic flow. You can also use this method
to obtain total filterable particulate if you sample within 90 to
110 percent of isokinetic flow, the number of sampling points is the
same as required by Method 5 of appendix A-3 to part 60 or Method 17
of appendix A-6 to part 60, and the filter temperature is within an
acceptable range for these methods. For Method 5, the acceptable
range for the filter temperature is generally 120 [deg]C (248
[deg]F) unless a higher or lower temperature is specified. The
acceptable range varies depending on the source, control technology
and applicable rule or permit condition. To satisfy Method 5
criteria, you may need to remove the in-stack filter and use an out-
of-stack filter and recover the PM in the probe between the
PM2.5 particle sizer and the filter. In addition, to
satisfy Method 5 and Method 17 criteria, you may need to sample from
more than 12 traverse points. Be aware that this method determines
in-stack PM10 and PM2.5 filterable emissions
by sampling from a recommended maximum of 12 sample points, at a
constant flow rate through the train (the constant flow is necessary
to maintain the size cuts of the cyclones), and with a filter that
is at the stack

temperature. In contrast, Method 5 or Method 17 trains are operated