Document ID: EPA-HQ-OAR-2002-0071-0063
Agency: epa
Document Type: Rule
Title: Update of Continuous Instrumental Test Methods
Posted Date: 2006-05-15T12:02:14Z

[Federal Register: May 15, 2006 (Volume 71, Number 93)]
[Rules and Regulations]               
[Page 28081-28104]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr15my06-10]                         

[[Page 28081]]

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Part II

Environmental Protection Agency

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40 CFR Part 60

Update of Continuous Instrumental Test Methods; Final Rule

[[Page 28082]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 60

[EPA-OAR-2002-0071; FRL-8165-1]
RIN 2060-AK61

 
Update of Continuous Instrumental Test Methods

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: On October 10, 2003, the EPA proposed amendments to update 
five instrumental test methods that are used to measure air pollutant 
emissions from stationary sources. These amendments are finalized in 
this document and reflect changes to the proposal to accommodate the 
public comments. This action is made to improve the methods by 
simplifying, harmonizing, and updating their procedures. A large number 
of industries are already subject to provisions that require the use of 
these methods. Some of the affected industries and their North American 
Industrial Classification System (NAICS) are listed under SUPPLEMENTARY 
INFORMATION.

DATES: This final rule is effective on August 14, 2006.

ADDRESSES: EPA has established a docket for this action under Docket ID 
No. OAR-2002-0071. All documents in the docket are listed on the http://www.regulations.gov
 Web site. Although listed in the index, some 

information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, is not placed on the Internet and will be 
publicly available only in hard copy form. Publicly available docket 
materials are available either electronically through http://www.regulations.gov
 or in hard copy at the Air and Radiation Docket, 

Docket ID No. OAR-2003-0071, EPA Docket Center (EPA/DC), EPA West, Room 
B102, 1301 Constitution Ave., NW., Washington, DC. The Public Reading 
Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, 
excluding legal holidays. The telephone number for the Public Reading 
Room is (202) 566-1744, and the telephone number for the Air and 
Radiation Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Foston Curtis, Measurement Technology 
Group (E143-02), Air Quality Assessment Division, EPA, Research 
Triangle Park, North Carolina 27711; telephone (919) 541-1063; fax 
number (919) 541-0516; electronic mail address: curtis.foston@epa.gov.

SUPPLEMENTARY INFORMATION: 

I. General Information

    A. Affected Entities. Categories and entities potentially regulated 
by the final rule include the following:

------------------------------------------------------------------------
     Examples of regulated entities          SIC codes      NAICS codes
------------------------------------------------------------------------
Fossil Fuel Steam Generators............            3569          332410
Industrial, Commercial, Institutional               3569          332410
 Steam Generating Units.................
Electric Generating.....................            3569          332410
Stationary Gas Turbines.................            3511          333611
Petroleum Refineries....................            2911          324110
Municipal Waste Combustors..............            4953          562213
Kraft Pulp Mills........................            2621          322110
Sulfuric Acid Plants....................            2819          325188
------------------------------------------------------------------------

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be affected by this 
action. This table lists examples of the types of entities EPA is now 
aware could potentially be affected by the final rule. Other types of 
entities not listed could also be affected. If you have any questions 
regarding the applicability of this action to a particular entity, 
consult the person listed in the preceding FOR FURTHER INFORMATION 
CONTACT section.
    B. Worldwide Web. In addition to being available in the docket, an 
electronic copy of today's final rule amendments will also be available 
on the Worldwide Web (WWW) through the Technology Transfer Network 
(TTN). Following the Administrator's signature, a copy of the final 
rule will be placed 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. Judicial Review. Under section 307(b)(1) of the Clean Air Act 
(CAA), judicial review of the final rule is available only by filing a 
petition for review in the U.S. Court of Appeals for the District of 
Columbia Circuit by July 14, 2006. Under section 307(d)(7)(B) of the 
CAA, only an objection to the final rule that was raised with 
reasonable specificity during the period for public comment can be 
raised during judicial review. Under CAA section 307(b)(2), the 
requirements established by the final rule may not be challenged later 
in civil or criminal proceedings brought by EPA to enforce these 
requirements.
    D. Outline. The information presented in this preamble is organized 
as follows:

I. Background
II. Summary of Major Comments and Revisions Since Proposal
    A. Uncertainty Calculation
    B. Sampling System Bias
    C. Calibration Drift Test
    D. Analyzer Calibration Error Test
    E. Interference Test
    F. Alternative Dynamic Spike Procedure
    G. Sampling Traverse Points
    H. Sampling Dilution Systems
    I. Equipment Heating Specifications
    J. Technology-Specific Analyzers
    K. Calibration Gases
    L. Method 7E Converter Test
III. Summary of Environmental, Energy, and Economic Impacts
    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: Action Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    I. NTTAA: National Technology Transfer and Advancement Act
    J. Congressional Review Act

I. Background

    Methods 3A, 6C, 7E, 10, and 20 are instrumental procedures used to 
measure oxygen, carbon dioxide, sulfur dioxide, nitrogen oxides, and 
carbon monoxide emissions in stationary sources. They are prescribed 
for determining compliance with a number of Federal, State, and Local 
regulations. Amendments to update these methods were originally 
proposed on August 27,

[[Page 28083]]

1997 (62 FR 45369) as part of an action to update the test methods in 
40 CFR parts 60, 61, and 63. Eight comment letters were received from 
this proposal with comments pertinent to Methods 3A, 6C, 7E, 10, and 
20. Some commenters thought insufficient notification was given in the 
preamble for the changes being proposed and asked that the instrumental 
method revisions be reproposed as a separate action. This separate 
proposal was published on October 10, 2003 (68 FR 58838) and contained 
additional revisions not included in the first proposal. Sixty one 
comment letters were received from this second proposal. These comments 
along with the comments received from the first proposal were used to 
make the appropriate changes to the proposed revisions.

II. Summary of Major Comments and Revisions Since Proposal

    A. Uncertainty Calculation. Numerous commenters disliked the 
proposed requirement to calculate data uncertainty in the method 
results and thought it inappropriate and confusing. It was noted that 
existing emission limitations were developed using emission data 
derived principally from these same test methods with no consideration 
of uncertainty. Further, the purpose of the Federal test methods is to 
provide a means of demonstrating compliance with the applicable 
requirements on the basis of the test method results. Most commenters 
objected to allowing regulatory agencies (or data end users) the 
discretion of accepting data close to an emission limit if the 
uncertainty determination is questionable, especially since no criteria 
for acceptable uncertainty were identified. The commenters thought that 
measurement uncertainty and data quality objectives present a number of 
very serious issues that are too easy for those without a thorough 
understanding of statistics to misapply. The resulting gray areas would 
incite many frivolous lawsuits by those who would use the perception of 
uncertainty to continuously challenge any decision made related to 
compliance. The commenters noted that the proposed revisions failed to 
provide a definition for uncertainty and the proposed uncertainty 
calculation reflected only two factors (sampling system bias and 
converter efficiency) that contribute to uncertainty, rather than all 
potential measurement factors. They preferred the tester and facility 
have a reasonable assurance that they have met the test requirements 
based on a properly quality assured test, not on an untenable 
uncertainty calculation.
    A number of commenters recommended retaining the bias-corrected 
data calculation currently in Method 6C in place of the proposed data 
uncertainty calculation.
    We agree with the commenters and have dropped the proposed 
requirement to calculate measurement uncertainty. The methods will 
retain a bias-correction for the sample concentration similar to what 
is current in Method 6C.
    B. Sampling System Bias. Several commenters found the proposed 
sampling system bias calculation that is based on the emission standard 
problematic because some units have no emission limit, others have more 
than one limit, and still others have limits in units other than 
concentration (e.g., lbs/hr, lb/mm BTU, or lb/ton feed). Most believed 
analyzer performance and accuracy are best evaluated as a function of 
analyzer span. One commenter wondered why the proposed bias test was 
based on the emission standard, while the other performance tests were 
not.
    In the proposal, the conversion table for sources that have 
standards in units other than concentration and the note in section 
1.3.3 advising the test to be designed around the most stringent 
standard in cases of multiple standards were attempts to alleviate the 
problems the commenters noted. We proposed using the emission limit in 
place of the span in the bias calculation to relieve what was thought 
to be an increased burden of passing the test when lower spans are 
chosen. The intent was to have testers use a consistent value in the 
denominator of the bias equation and emphasize the greatest accuracy in 
the range of the emission standard. This approach appears to have added 
more complication than it was intended to relieve.
    In the final rule, the proposed change to calculate the bias 
relative to the emission standard has been dropped. The bias 
determination as a percentage of the span is retained. However, 
``span'' has been changed to ``calibration span'' which is equivalent 
to the concentration of the high calibration gas as in the proposal. In 
the current methods, the span is any number that doesn't result in the 
emission standard being less than 30 percent of the span. The high 
calibration gas chosen for this span must then be 80-100 percent of the 
span. This allows a concentration interval between the high calibration 
gas and the span that is not quality assured. This interval has been 
eliminated.
    The traditional ``span'' was often mistaken for and used 
interchangeably with ``analyzer range.'' With the ``calibration span,'' 
only the calibrated portion of the analyzer range is of concern, and 
any value that exceeds the calibration span is considered invalid.
    This approach offers several additional advantages. First, it gives 
the tester flexibility to set the calibration range at a convenient 
number that is not excessive. Second, it alleviates concern about the 
quality of data points that are currently allowed between the high 
calibration concentration and the span. Third, if it is properly chosen 
with the majority of measurements in the 20-to-100 percent range, it 
would prevent a tester from choosing an inordinately high calibration 
range which reduces measurement accuracy.
    C. Calibration Drift Test. Commenters generally thought that the 
between-run calibration drift requirement should not be eliminated as 
in the proposal. We have taken this recommendation and retained the 
between-run drift determination.
    D. Analyzer Calibration Error Test. Two commenters thought the 
proposed limit for calibration error of 2 percent of the certified gas 
concentration was unnecessarily restrictive when compared to the 
existing 2 percent of span specification. They noted that EPA gave no 
technical basis for such increased restriction and recommended the 
proposed change be dropped. Others wondered why the same gases were 
required for the analyzer setup and the calibration error test? This 
seemed redundant.
    The proposed requirement that the analyzer calibration error be 
within 2 percent of the tag value has been changed to 2 percent of the 
calibration span. The proposed requirement to calibrate the instrument 
with the same gases used in the calibration error test has been 
dropped.
    E. Interference Test. Commenters in general objected to EPA's 
proposed requirement to conduct the interference test on an annual 
basis. They noted that little evidence was provided to show that annual 
interference testing was necessary. They believed the test should only 
be repeated after major instrument modifications. Annual interference 
testing was thought to put a major burden on the testing companies.
    The commenters raised valid concerns. The proposed requirement to 
conduct the interference test on an annual basis has been dropped. The 
interference test will remain a one-time test except for major 
instrument modifications, as is the current requirement. The current 
interference test in Method 6C, where the analyzer is compared to 
modified Method 6

[[Page 28084]]

samples in the field, is now listed as the alternative interference 
test procedure since this approach was considered archaic by some 
commenters. An interference test where the analyzer is challenged by 
potential interferent gases is now the primary procedure.
    F. Alternative Dynamic Spike Procedure. Commenters thought the 
dynamic spiking procedure was confusing and lacked sufficient detail to 
perform. Some commenters thought adding the procedure was a good idea; 
others strenuously objected to even allowing it as an option.
    We have retained the allowance to use dynamic spiking as an 
alternative to the interference and bias tests, except for part 75 
applications, where Administrative approval is required to use the 
procedure. We purposely made the procedure general and performance-
based instead of making it prescriptive because different procedures 
may be followed to perform it successfully. We believe that dynamic 
spiking is a valuable tool for evaluating a method and should be 
retained as an alternative for testers able to perform it. Clarity has 
been added to the procedure details where possible to remove confusion.
    G. Sampling Traverse Points. Comments were mixed on the proposed 
requirement to use Method 1 unless a stratification test showed fewer 
sampling point are justified. The majority did not think a Method 1 
determination was justified for gaseous sampling in all cases and that 
this made the methods burdensome and significantly more costly to use. 
Others proposed reducing the number of points to three, as are allowed 
in relative accuracy testing of continuous emission monitoring systems. 
Two commenters recommended dropping the proposed requirement to correct 
the pollutant concentration for diluent in the stratification test.
    In the final rule, the tester may either sample at twelve Method 1 
points or a stratification test (3-point or 12-point) may be performed. 
If the stratification test is done and results in a concentration 
deviation of any point from the mean concentration by more than 10 
percent, then a minimum of twelve traverse points located according to 
Method 1 must be sampled. If the concentrations of all stratification 
test points are less than 10 percent from the mean, the testing may 
resume using 3 traverse points. If the concentrations at all 
stratification test points are less than 5 percent from the mean, then 
single-point testing may be performed. Note that these traverse point 
layout rules are not intended to apply to relative accuracy test audits 
(RATA) of continuous emission monitoring systems (CEMS) where 
applicable CEMS quality assurance requirements specify specific 
traverse point selection requirements for RATA.
    H. Sampling Dilution Systems. Commenters recommended that EPA 
specifically state that dilution-based sampling technology is an 
acceptable technique. These systems have been approved by the Emission 
Measurement Center (EMC) as alternative method ALT-007 (Use of Dilution 
Probes with Instrumental Methods). Guidance Document 18 from EMC also 
indicates that dilution sampling systems are acceptable for use with 
Methods 6C, 7E, 20, and 10, and the special requirements of dilution-
based sampling are addressed. This information, or the discussions 
found in Chapter 21 of the Part 75 Emissions Monitoring Policy Manual 
were recommended for addition to the methods.
    The instrumental methods have been modified to clearly note that 
dilution systems are acceptable. We have included discussions of 
calibration gas needs relative to the sample gas molecular weight, 
calibration drift test variations, and other instructions pertinent to 
dilutions systems that were a part of EMC Guidance Document GD-18.
    I. Equipment Heating Specifications. Several commenters criticized 
the numerous references to equipment heating that were thought to 
preclude the use of other techniques of preventing sample loss. We were 
urged to require that the sample be maintained at a temperature above 
the dew point of the sample gas rather than specifying minimum 
equipment temperatures to provide a technology-neutral approach.
    The language has been changed to allow the tester to choose which 
procedure or technology to use for preventing condensation. The final 
rule requires the sample gas be maintained above the dew point of the 
stack gas (including all gas components, e.g. acid gas constituents) so 
that no loss of sample results. This may be done by heating, diluting, 
drying, desiccating, a combination thereof, or by other means.
    J. Technology-Specific Analyzers. Various references to specific 
technologies throughout the methods were noted. Most commenters wanted 
us to remove these references. One commenter implicated electrochemical 
cells for providing completely unreliable results when not operated in 
diffusion limiting conditions even though such analyzers could meet the 
performance criteria of the proposal while operating outside of 
diffusion-limiting conditions. The commenter recommended this 
technology be subject to special procedures such as those included in 
ASTM D6522-00.
    We have removed the references to specific technologies in the 
methods to make them flexible and performance-based, not technology-
based. It may be difficult to set performance requirements that 
appropriately evaluate all analytical techniques 100 percent of the 
time. However, we believe the interference, calibration error, and bias 
tests provide adequate assessments of performance for the majority of 
the time. The electrochemical analyzer has been shown capable of 
producing reliable results in an Environmental Technology Verification 
study, and we do not believe special restrictions should be placed on 
this technology.
    K. Calibration Gases. Commenters asked that we list all of the 
allowable calibration gas blends in the methods. They wanted the 
wording changed to allow the flexibility of blending standards with 
other gases that can be shown not to interfere. One commenter thought 
the proposed mid-level calibration gas range of 20 to 70 percent of the 
span-level gas was an improvement over the existing 40 to 60 percent 
range. Another commenter thought this would allow for poor selection of 
mid-level gases. Other commenters wondered if it was acceptable to 
prepare calibration gases from a single high-concentration EPA 
Traceability Protocol gas using Method 205.
    Blended calibration gases are allowed in the final rule provided 
they are made from Traceability Protocol gases and any additional gas 
components are shown not to interfere with the analysis. After 
considering the comments, the EPA has decided to retain the current 40- 
to 60-percent of span requirement for the mid-level gas. We believe 
this ensures a better evaluation of the analyzer's linear response, as 
noted by one of the commenters. In the final rule, Method 205 is 
allowed to prepare calibration gases from high-concentration gases of 
EPA Traceability Protocol quality, except for part 75 applications, 
which require administrative approval to use this technique.
    L. Method 7E Converter Test. Several commenters noted that the 
nitrogen dioxide (NO2) calibration gas used in the converter 
efficiency test is not available as an EPA Traceability Protocol 
Standard as required. This prevents one from performing the test. 
Because NO2 has unusual storage problems, it is difficult to 
maintain the gas at its certified concentration. A search of vendors 
has shown that gas of

[[Page 28085]]

traceability protocol quality is available commercially, but in limited 
concentrations and from limited sources. We also concur with the long-
term stability problems noted with NO2 cylinder gas. Because 
of these concerns, we have retained the original procedures cited in 
Method 20 for determining converter efficiency and have listed the 
proposed procedure for direct evaluation with NO2 as an 
allowable alternative. Numerous commenters pointed out the error in the 
converter efficiency correction in the uncertainty calculation. This 
error has been corrected through a new equation.
    Commenters generally thought that requiring the converter 
efficiency gas be in the concentration range of the source emissions 
was too restrictive and would require numerous gas cylinders be 
transported into the field. We understand the difficulty in preparing 
test gases to match anticipated emission levels. Therefore, we have 
dropped the proposed requirement to match the stack NO2 
concentration within 50 percent and instead require gas in the 40 to 60 
ppm range for all cases.

IV. Summary of Environmental, Energy, and Economic Impacts

A. Executive Order 12866: Regulatory Planning and Reviews

    Under Executive Order 12866 (58 FR 51735 October 4, 1993), the EPA 
must determine whether this regulatory action is ``significant'' and 
therefore subject to review by the Office of Management and Budget 
(OMB) and the requirements of the Executive Order. The Order defines 
``significant regulatory action'' as one that is likely to result in a 
rule that may: (1) Have an annual effect on the economy of $100 million 
or more or adversely affects in a material way the economy, a sector of 
the economy, productivity, competition, jobs, the environment, public 
health or safety, or State, Local, or Tribal governments or 
communities; (2) create a serious inconsistency or otherwise interferes 
with an action taken or planned by another agency; (3) materially alter 
the budgetary impact of entitlements, grants, user fees, or loan 
programs, or the rights and obligations of recipients thereof; or (4) 
raise novel legal or policy issues arising out of legal mandates, the 
President's priorities, or the principles set forth in the Executive 
Order.
    We have determined that this rule is not a ``significant regulatory 
action'' under the terms of Executive Order 12866 and is therefore not 
subject to OMB review. We have determined that this regulation would 
result in none of the economic effects set forth in Section 1 of the 
Order because it does not impose emission measurement requirements 
beyond those specified in the current regulations, nor does it change 
any emission standard.

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. 
These criteria do not add information collection requirements beyond 
those currently required under the applicable regulation. The 
amendments being made to the test methods do not add information 
collection requirements but make needed updates to existing testing 
methodology.
    Burden means the total time, effort, or financial resources 
expended by persons to generate, maintain, retain, or disclose or 
provide information to or for a Federal agency. This includes the time 
needed to review instructions; develop, acquire, install, and utilize 
technology and systems for the purposes of collecting, validating, and 
verifying information, processing and maintaining information, and 
disclosing and providing information; adjust the existing ways to 
comply with any previously applicable instructions and requirements; 
train personnel to be able to respond to a collection of information; 
search data sources; complete and review the collection of information; 
and transmit or otherwise disclose the information.
    An agency may not conduct or sponsor, and a person is not required 
to respond to a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations in 40 CFR are listed in 40 CFR part 9.

C. Regulatory Flexibility Act

    EPA has determined that it is not necessary to prepare a regulatory 
flexibility analysis in connection with this final rule.
    For purposes of assessing the impacts of today's rule on small 
entities, small entity is defined as: (1) A small business as defined 
by the Small Business Administrations' 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. Entities potentially affected by this action 
include those listed in Table 1 of SUPPLEMENTARY INFORMATION.
    After considering the economic impacts of today's final rule on 
small entities, I have concluded that this action will not have a 
significant economic impact on a substantial number of small entities. 
This rule reflects changes to the proposal to accommodate the public 
comments and is made to improve the test methods by simplifying, 
harmonizing, and updating their procedures. A large number of the 
regulated industries are already subject to the provisions that require 
the use of these methods and this rule does not impose any new emission 
measurement requirements beyond those specified in the current 
regulations, nor does it change any emission standard but makes needed 
updates to existing testing methodology. This rule would also add some 
flexibility by giving testers more choice in selecting their test 
equipment which could translate into reduced costs for the regulated 
industries.

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
Law 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, Local, and Tribal 
governments and the private sector. Under section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in expenditures to State, Local, and Tribal governments, in 
the aggregate, or to the private sector, of $100 million or more in any 
one year. Before promulgating an EPA rule for which a written statement 
is needed, section 205 of the UMRA generally requires EPA to identify 
and consider a reasonable number of regulatory alternatives and adopt 
the least costly, most cost-effective or least burdensome alternative 
that achieves the objectives of the rule. The provisions of section 205 
do not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective or least burdensome alternative if the 
Administrator publishes with the final rule an explanation why that 
alternative was not adopted. Before EPA establishes any regulatory 
requirements that may significantly or uniquely affect small 
governments, including tribal governments, it must have developed under 
section 203 of the UMRA a small government agency plan. The plan must 
provide for notifying potentially

[[Page 28086]]

affected small governments, enabling officials of affected small 
governments to have meaningful and timely input in the development of 
EPA regulatory proposals with significant Federal intergovernmental 
mandates, and informing, educating, and advising small governments on 
compliance with the regulatory requirements.
    Today's rule contains no Federal mandates (under the regulatory 
provisions of Title II of the UMRA) for State, Local, or Tribal 
governments or the private sector. The rule imposes no enforceable duty 
on any State, Local, or Tribal governments or the private sector. In 
any event, EPA has determined that this rule does not contain a Federal 
mandate that may result in expenditures of $100 million or more for 
State, Local, and Tribal governments, in the aggregate, or the private 
sector in any one year. Thus, today's rule is not subject to the 
requirements of sections 202 and 205 of the UMRA.

E. Executive Order 13132: Federalism

    Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August 
10, 1999), requires EPA to develop an accountable process to ensure 
``meaningful and timely input by State and Local officials in the 
development of regulatory policies that have federalism implications.'' 
``Policies that have federalism implications'' are defined in the 
Executive Order to include regulations that 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.''
    This rule 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. Thus, the requirements of section 6 
of the Executive Order do not apply to this rule.

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

    Executive Order 13175, entitled ``Consultation and Coordination 
with Indian Tribal Governments'' (65 FR 67249, November 6, 2000), 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by tribal officials in the development of regulatory 
policies that have tribal implications.'' ``Policies that have tribal 
implications'' is defined in the Executive Order to include regulations 
that have ``substantial direct effects on one or more Indian tribes, on 
the relationship between the Federal government and the Indian tribes, 
or on the distribution of power and responsibilities between the 
Federal government and Indian tribes.''
    This final rule does not have tribal implications. It will not have 
substantial direct effects on tribal governments, on the relationship 
between the Federal government and Indian tribes, or on the 
distribution of power and responsibilities between the Federal 
government and Indian tribes, as specified in Executive Order 13175. In 
this final rule, we are simply updating existing pollutant test 
methods. Thus, Executive Order 13175 does not apply to this rule.

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

    Executive Order 13045 applies to any rule that EPA determines (1) 
is ``economically significant'' as defined under Executive Order 12866, 
and (2) the environmental health or safety risk addressed by the rule 
has a disproportionate effect on children. If the regulatory action 
meets both criteria, the Agency must evaluate the environmental health 
or safety effects of the planned rule on children and explain why the 
planned regulation is preferable to other potentially effective and 
reasonably feasible alternatives considered by the Agency.
    The EPA interprets Executive Order 13045 as applying only to 
regulatory actions that are based on 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 final rule is not 
subject to Executive Order 13045 because it is not based on 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, ``Actions 
Concerning Regulations that Significantly Affect Energy Supply, 
Distribution, or Use'' (66 FR 28355, May 22, 2001) because it is not a 
significant regulatory action under Executive Order 12866.

I. NTTAA: National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113 (15 U.S.C. 272), directs us to 
use voluntary consensus standards (VCS) in our 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, 
business practices, etc.) that are developed or adopted by VCS bodies. 
The NTTAA requires us to provide Congress, through OMB, explanations 
when we decide not to use available and applicable VCS. We are 
requiring new test methods in this rulemaking. Therefore, NTTAA does 
not apply.

J. 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. The EPA will submit a report containing the final rule 
amendments 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 final rule amendments in the Federal 
Register. A major rule cannot take effect until 60 days after its 
publication in the Federal Register. This action is not a ``major 
rule'' as defined by 5 U.S.C. 804(2). The final rule amendments will be 
effective on July 14, 2006.

List of Subjects in 40 CFR Part 60

    Environmental protection, Air pollution control, New sources, Test 
methods and procedures, Performance specifications, and Continuous 
emission monitors.

    Dated: April 28, 2006.
Stephen L. Johnson,
Administrator.

0
For the reasons stated in the preamble, title 40, chapter I, part 60 of 
the Code of Federal Regulations is amended as follows:

PART 60--[AMENDED]

0
1. The authority citation for part 60 continues to read as follows:

    Authority: 42 U.S.C. 7401 et seq.

0
2. Appendix A-2 is amended by revising Method 3A to read as follows:

Appendix A-2 to Part 60--Test Methods 2G Through 3C

* * * * *

[[Page 28087]]

Method 3A--Determination of Oxygen and Carbon Dioxide Concentrations in 
Emissions From Stationary Sources (Instrumental Analyzer Procedure)

1.0 Scope and Application

What is Method 3A?

    Method 3A is a procedure for measuring oxygen (O2) 
and carbon dioxide (CO2) in stationary source emissions 
using a continuous instrumental analyzer. Quality assurance and 
quality control requirements are included to assure that you, the 
tester, collect data of known quality. You must document your 
adherence to these specific requirements for equipment, supplies, 
sample collection and analysis, calculations, and data analysis.
    This method does not completely describe all equipment, 
supplies, and sampling and analytical procedures you will need but 
refers to other methods for some of the details. Therefore, to 
obtain reliable results, you should also have a thorough knowledge 
of these additional test methods which are found in appendix A to 
this part:
    (a) Method 1--Sample and Velocity Traverses for Stationary 
Sources.
    (b) Method 3--Gas Analysis for the Determination of Molecular 
Weight.
    (c) Method 4--Determination of Moisture Content in Stack Gases.
    (d) Method 7E--Determination of Nitrogen Oxides Emissions from 
Stationary Sources (Instrumental Analyzer Procedure).
    1.1 Analytes. What does this method determine? This method 
measures the concentration of oxygen and carbon dioxide.

------------------------------------------------------------------------
            Analyte                  CAS No.           Sensitivity
------------------------------------------------------------------------
Oxygen (O2)....................       7782-44-7  Typically < 2% of
                                                  Calibration Span.
Carbon dioxide (CO2)...........        124-38-9  Typically < 2% of
                                                  Calibration Span.
------------------------------------------------------------------------

    1.2 Applicability. When is this method required? The use of 
Method 3A may be required by specific New Source Performance 
Standards, Clean Air Marketing rules, State Implementation Plans and 
permits, where measurements of O2 and CO2 
concentrations in stationary source emissions must be made, either 
to determine compliance with an applicable emission standard or to 
conduct performance testing of a continuous emission monitoring 
system (CEMS). Other regulations may also require the use of Method 
3A.
    1.3 Data Quality Objectives. How good must my collected data be? 
Refer to Section 1.3 of Method 7E.

2.0 Summary of Method

    In this method, you continuously or intermittently sample the 
effluent gas and convey the sample to an analyzer that measures the 
concentration of O2 or CO2. You must meet the 
performance requirements of this method to validate your data.

3.0 Definitions

    Refer to Section 3.0 of Method 7E for the applicable 
definitions.

4.0 Interferences [Reserved]

5.0 Safety

    Refer to Section 5.0 of Method 7E.

6.0 Equipment and Supplies

    Figure 7E-1 in Method 7E is a schematic diagram of an acceptable 
measurement system.
    6.1 What do I need for the measurement system? The components of 
the measurement system are described (as applicable) in Sections 6.1 
and 6.2 of Method 7E, except that the analyzer described in Section 
6.2 of this method must be used instead of the analyzer described in 
Method 7E. You must follow the noted specifications in Section 6.1 
of Method 7E except that the requirements to use stainless steel, 
Teflon, or non-reactive glass filters do not apply. Also, a heated 
sample line is not required to transport dry gases or for systems 
that measure the O2 or CO2 concentration on a 
dry basis, provided that the system is not also being used to 
concurrently measure SO2 and/or NOX.
    6.2 What analyzer must I use? You must use an analyzer that 
continuously measures O2 or CO2 in the gas 
stream and meets the specifications in Section 13.0.

7.0 Reagents and Standards

    7.1 Calibration Gas. What calibration gases do I need? Refer to 
Section 7.1 of Method 7E for the calibration gas requirements. 
Example calibration gas mixtures are listed below.
    (a) CO2 in nitrogen (N2).
    (b) CO2 in air.
    (c) CO2/SO2 gas mixture in N2.
    (d) O2/SO2 gas mixture in N2.
    (e) O2/CO2/SO2 gas mixture in 
N2.
    (f) CO2/NOX gas mixture in N2.
    (g) CO2/SO2/NOX gas mixture in 
N2.
    The tests for analyzer calibration error and system bias require 
high-, mid-, and low-level gases.
    7.2 Interference Check. What reagents do I need for the 
interference check? Potential interferences may vary among available 
analyzers. Table 7E-3 of Method 7E lists a number of gases that 
should be considered in conducting the interference test.

8.0 Sample Collection, Preservation, Storage, and Transport

    8.1 Sampling Site and Sampling Points. You must follow the 
procedures of Section 8.1 of Method 7E to determine the appropriate 
sampling points, unless you are using Method 3A only to determine 
the stack gas molecular weight and for no other purpose. In that 
case, you may use single-point integrated sampling as described in 
Section 8.2 of Method 3. If the stratification test provisions in 
Section 8.1.2 of Method 7E are used to reduce the number of required 
sampling points, the alternative acceptance criterion for 3-point 
sampling will be  0.5 percent CO2 or 
O2, and the alternative acceptance criterion for single-
point sampling will be  0.3 percent CO2 or 
O2.
    8.2 Initial Measurement System Performance Tests. You must 
follow the procedures in Section 8.2 of Method 7E. If a dilution-
type measurement system is used, the special considerations in 
Section 8.3 of Method 7E apply.
    8.3 Interference Check. The O2 or CO2 
analyzer must be documented to show that interference effects to not 
exceed 2.5 percent of the calibration span. The interference test in 
Section 8.2.7 of Method 7E is a procedure that may be used to show 
this. The effects of all potential interferences at the 
concentrations encountered during testing must be addressed and 
documented. This testing and documentation may be done by the 
instrument manufacturer.
    8.4 Sample Collection. You must follow the procedures in Section 
8.4 of Method 7E.
    8.5 Post-Run System Bias Check and Drift Assessment. You must 
follow the procedures in Section 8.5 of Method 7E.

9.0 Quality Control

    Follow quality control procedures in Section 9.0 of Method 7E.

10.0 Calibration and Standardization

    Follow the procedures for calibration and standardization in 
Section 10.0 of Method 7E.

11.0 Analytical Procedures

    Because sample collection and analysis are performed together 
(see Section 8), additional discussion of the analytical procedure 
is not necessary.

12.0 Calculations and Data Analysis

    You must follow the applicable procedures for calculations and 
data analysis in Section 12.0 of Method 7E, substituting percent 
O2 and percent CO2 for ppmv of NOX 
as appropriate.

13.0 Method Performance

    The specifications for the applicable performance checks are the 
same as in Section 13.0 of Method 7E except for the alternative 
specifications for system bias, drift, and calibration error. In 
these alternative specifications, replace the term ``0.5 ppmv'' with 
the term ``0.5 percent O2'' or ``0.5 percent 
CO2'' (as applicable).

14.0 Pollution Prevention [Reserved]

15.0 Waste Management [Reserved]

16.0 Alternative Procedures [Reserved]

17.0 References

    1. ``EPA Traceability Protocol for Assay and Certification of 
Gaseous Calibration Standards'' September 1997 as amended, EPA-600/
R-97/121.

18.0 Tables, Diagrams, Flowcharts, and Validation Data

    Refer to Section 18.0 of Method 7E.
* * * * *

[[Page 28088]]

0
3. Appendix A-4 is amended by revising Methods 6C, 7E, and 10 to read 
as follows:

Appendix A-4 to Part 60--Test Methods 6 Through 10B

* * * * *

Method 6C--Determination of Sulfur Dioxide Emissions From Stationary 
Sources (Instrumental Analyzer Procedure)

1.0 Scope and Application

What is Method 6C?

    Method 6C is a procedure for measuring sulfur dioxide 
(SO2) in stationary source emissions using a continuous 
instrumental analyzer. Quality assurance and quality control 
requirements are included to assure that you, the tester, collect 
data of known quality. You must document your adherence to these 
specific requirements for equipment, supplies, sample collection and 
analysis, calculations, and data analysis.
    This method does not completely describe all equipment, 
supplies, and sampling and analytical procedures you will need but 
refers to other methods for some of the details. Therefore, to 
obtain reliable results, you should also have a thorough knowledge 
of these additional test methods which are found in appendix A to 
this part:
    (a) Method 1--Sample and Velocity Traverses for Stationary 
Sources.
    (b) Method 4--Determination of Moisture Content in Stack Gases.
    (c) Method 6--Determination of Sulfur Dioxide Emissions from 
Stationary Sources.
    (d) Method 7E--Determination of Nitrogen Oxides Emissions from 
Stationary Sources (Instrumental Analyzer Procedure).
    1.1 Analytes. What does this method determine? This method 
measures the concentration of sulfur dioxide.

------------------------------------------------------------------------
            Analyte                  CAS No.           Sensitivity
------------------------------------------------------------------------
SO2............................       7446-09-5  Typically < 2% of
                                                  Calibration Span.
------------------------------------------------------------------------

    1.2 Applicability. When is this method required? The use of 
Method 6C may be required by specific New Source Performance 
Standards, Clean Air Marketing rules, State Implementation Plans, 
and permits where SO2 concentrations in stationary source 
emissions must be measured, either to determine compliance with an 
applicable emission standard or to conduct performance testing of a 
continuous emission monitoring system (CEMS). Other regulations may 
also require the use of Method 6C.
    1.3 Data Quality Objectives. How good must my collected data be? 
Refer to Section 1.3 of Method 7E.

2.0 Summary of Method

    In this method, you continuously sample the effluent gas and 
convey the sample to an analyzer that measures the concentration of 
SO2. You must meet the performance requirements of this 
method to validate your data.

3.0 Definitions

    Refer to Section 3.0 of Method 7E for the applicable 
definitions.

4.0 Interferences

    Refer to Section 4.1 of Method 6.

5.0 Safety

    Refer to Section 5.0 of Method 7E.

6.0 Equipment and Supplies

    Figure 7E-1 of Method 7E is a schematic diagram of an acceptable 
measurement system.
    6.1 What do I need for the measurement system? The essential 
components of the measurement system are the same as those in 
Sections 6.1 and 6.2 of Method 7E, except that the SO2 
analyzer described in Section 6.2 of this method must be used 
instead of the analyzer described in Section 6.2 of Method 7E. You 
must follow the noted specifications in Section 6.1 of Method 7E.
    6.2 What analyzer must I use? You may use an instrument that 
uses an ultraviolet, non-dispersive infrared, fluorescence, or other 
detection principle to continuously measure SO2 in the 
gas stream and meets the performance specifications in Section 13.0. 
The low-range and dual-range analyzer provisions in Section 6.2.8.1 
of Method 7E apply.

7.0 Reagents and Standards

    7.1 Calibration Gas. What calibration gases do I need? Refer to 
Section 7.1 of Method 7E for the calibration gas requirements. 
Example calibration gas mixtures are listed below.
    (a) SO2 in nitrogen (N2).
    (b) SO2 in air.
    (c) SO2 and CO2 in N2.
    (d) SO2 andO2 in N2.
    (e) SO2/CO2/O2 gas mixture in 
N2.
    (f) CO2/NOX gas mixture in N2.
    (g) CO2/SO2/NOX gas mixture in 
N2.
    7.2 Interference Check. What additional reagents do I need for 
the interference check? The test gases for the interference check 
are listed in Table 7E-3 of Method 7E. For the alternative 
interference check, you must use the reagents described in Section 
7.0 of Method 6.

8.0 Sample Collection, Preservation, Storage, and Transport

    8.1 Sampling Site and Sampling Points. You must follow the 
procedures of Section 8.1 of Method 7E.
    8.2 Initial Measurement System Performance Tests. You must 
follow the procedures in Section 8.2 of Method 7E. If a dilution-
type measurement system is used, the special considerations in 
Section 8.3 of Method 7E also apply.
    8.3 Interference Check. You must follow the procedures of 
Section 8.2.7 of Method 7E to conduct an interference check, 
substituting SO2 for NOX as the method 
pollutant. For dilution-type measurement systems, you must use the 
alternative interference check procedure in Section 16 and a co-
located, unmodified Method 6 sampling train.
    8.4 Sample Collection. You must follow the procedures of Section 
8.4 of Method 7E.
    8.5 Post-Run System Bias Check and Drift Assessment. You must 
follow the procedures of Section 8.5 of Method 7E.

9.0 Quality Control

    Follow quality control procedures in Section 9.0 of Method 7E.

10.0 Calibration and Standardization

    Follow the procedures for calibration and standardization in 
Section 10.0 of Method 7E.

11.0 Analytical Procedures

    Because sample collection and analysis are performed together 
(see Section 8), additional discussion of the analytical procedure 
is not necessary.

12.0 Calculations and Data Analysis

    You must follow the applicable procedures for calculations and 
data analysis in Section 12.0 of Method 7E as applicable, 
substituting SO2 for NOX as appropriate.

13.0 Method Performance

    13.1 The specifications for the applicable performance checks 
are the same as in Section 13.0 of Method 7E.
    13.2 Alternative Interference Check. The results are acceptable 
if the difference between the Method 6C result and the modified 
Method 6 result is less than 7.0 percent of the Method 6 result for 
each of the three test runs. For the purposes of comparison, the 
Method 6 and 6C results must be expressed in the same units of 
measure.

14.0 Pollution Prevention [Reserved]

15.0 Waste Management [Reserved]

16.0 Alternative Procedures

    16.1 Alternative Interference Check. You may perform an 
alternative interference check consisting of at least three 
comparison runs between Method 6C and Method 6. This check validates 
the Method 6C results at each particular facility of known potential 
interferences. When testing under conditions of low concentrations 
(<  15 ppm), this alternative interference check is not allowed.

    Note: The procedure described below applies to non-dilution 
sampling systems only. If this alternative interference check is 
used for a dilution sampling system, use a standard Method 6 
sampling train and extract the sample directly from the exhaust 
stream at points collocated with the Method 6C sample probe.

[[Page 28089]]

    (1) Build the modified Method 6 sampling train (flow control 
valve, two midget impingers containing 3 percent hydrogen peroxide, 
and dry gas meter) shown in Figure 6C-1. Connect the sampling train 
to the sample bypass discharge vent. Record the dry gas meter 
reading before you begin sampling. Simultaneously collect modified 
Method 6 and Method 6C samples. Open the flow control valve in the 
modified Method 6 train as you begin to sample with Method 6C. 
Adjust the Method 6 sampling rate to 1 liter per minute (.10 
percent). The sampling time per run must be the same as for Method 6 
plus twice the average measurement system response time. If your 
modified Method 6 train does not include a pump, you risk biasing 
the results high if you over-pressurize the midget impingers and 
cause a leak. You can reduce this risk by cautiously increasing the 
flow rate as sampling begins.
    (2) After completing a run, record the final dry gas meter 
reading, meter temperature, and barometric pressure. Recover and 
analyze the contents of the midget impingers using the procedures in 
Method 6. You must analyze performance audit samples as described in 
Method 6 with this interference check. Determine the average gas 
concentration reported by Method 6C for the run.

17.0 References

    1. ``EPA Traceability Protocol for Assay and Certification of 
Gaseous Calibration Standards'' September 1997 as amended, EPA-600/
R-97/121

18.0 Tables, Diagrams, Flowcharts, and Validation Data
[GRAPHIC] [TIFF OMITTED] TR15MY06.000

* * * * *

Method 7E--Determination of Nitrogen Oxides Emissions From Stationary 
Sources (Instrumental Analyzer Procedure)

1.0 Scope and Application

What is Method 7E?

    Method 7E is a procedure for measuring nitrogen oxides 
(NOX) in stationary source emissions using a continuous 
instrumental analyzer. Quality assurance and quality control 
requirements are included to assure that you, the tester, collect 
data of known quality. You must document your adherence to these 
specific requirements for equipment, supplies, sample collection and 
analysis, calculations, and data analysis. This method does not 
completely describe all equipment, supplies, and sampling and 
analytical procedures you will need but refers to other methods for 
some of the details. Therefore, to obtain reliable results, you 
should also have a thorough knowledge of these additional test 
methods which are found in appendix A to this part:
    (a) Method 1--Sample and Velocity Traverses for Stationary 
Sources.
    (b) Method 4--Determination of Moisture Content in Stack Gases.
    1.1 Analytes. What does this method determine? This method 
measures the concentration of nitrogen oxides as NO2.

------------------------------------------------------------------------
            Analyte                  CAS No.           Sensitivity
------------------------------------------------------------------------
Nitric oxide (NO)..............      10102-43-9  Typically < 2% of
Nitrogen dioxide (NO2).........      10102-44-0  Calibration Span.
------------------------------------------------------------------------

    1.2 Applicability. When is this method required? The use of 
Method 7E may be required by specific New Source Performance 
Standards, Clean Air Marketing rules, State Implementation Plans, 
and permits where measurement of NOX concentrations in 
stationary source emissions is required, either to determine 
compliance with an applicable emissions standard or to conduct 
performance testing of a continuous monitoring system (CEMS). Other 
regulations may also require the use of Method 7E.
    1.3 Data Quality Objectives (DQO). How good must my collected 
data be? Method 7E is designed to provide high-quality data for 
determining compliance with Federal and State emission standards and 
for relative accuracy testing of CEMS. In these and other 
applications, the principal objective is to ensure the accuracy of 
the data at the actual emission levels encountered. To meet this 
objective, the use of EPA traceability protocol calibration gases 
and measurement system performance tests are required.
    1.4 Data Quality Assessment for Low Emitters. Is performance 
relief granted when testing low-emission units? Yes. For low-
emitting sources, there are alternative performance specifications 
for analyzer calibration error, system bias, drift, and

[[Page 28090]]

response time. Also, the alternative dynamic spiking procedure in 
Section 16 may provide performance relief for certain low-emitting 
units.

2.0 Summary of Method

    In this method, a sample of the effluent gas is continuously 
sampled and conveyed to the analyzer for measuring the concentration 
of NOX. You may measure NO and NO2 separately 
or simultaneously together but, for the purposes of this method, 
NOX is the sum of NO and NO2. You must meet 
the performance requirements of this method to validate your data.

3.0 Definitions

    3.1 Analyzer Calibration Error, for non-dilution systems, means 
the difference between the manufacturer certified concentration of a 
calibration gas and the measured concentration of the same gas when 
it is introduced into the analyzer in direct calibration mode.
    3.2 Calibration Curve means the relationship between an 
analyzer's response to the injection of a series of calibration 
gases and the actual concentrations of those gases.
    3.3 Calibration Gas means the gas mixture containing 
NOX at a known concentration and produced and certified 
in accordance with ``EPA Traceability Protocol for Assay and 
Certification of Gaseous Calibration Standards,'' September 1997, as 
amended August 25, 1999, EPA-600/R-97/121 or more recent updates. 
The tests for analyzer calibration error, drift, and system bias 
require the use of calibration gas prepared according to this 
protocol.
    3.3.1 Low-Level Gas means a calibration gas with a concentration 
that is less than 20 percent of the calibration span and may be a 
zero gas.
    3.3.2 Mid-Level Gas means a calibration gas with a concentration 
that is 40 to 60 percent of the calibration span.
    3.3.3 High-Level Gas means a calibration gas with a 
concentration that is equal to the calibration span.
    3.4 Calibration Span means the upper limit of valid instrument 
response during sampling. To the extent practicable, the measured 
emissions should be between 20 to 100 percent of the selected 
calibration span
    3.5 Centroidal Area means the central area of the stack or duct 
that is no greater than 1 percent of the stack or duct cross 
section. This area has the same geometric shape as the stack or 
duct.
    3.6 Converter Efficiency Gas means a calibration gas with a 
known NO or NO2 concentration and of Traceability 
Protocol quality.
    3.7 Data Recorder means the equipment that permanently records 
the concentrations reported by the analyzer.
    3.8 Direct Calibration Mode means introducing the calibration 
gases directly into the analyzer (or into the assembled measurement 
system at a point downstream of all sample conditioning equipment) 
according to manufacturer's recommended calibration procedure. This 
mode of calibration applies to non-dilution-type measurement 
systems.
    3.9 Drift means the difference between the measurement system 
readings obtained in the pre-run and post-run system bias (or system 
calibration error) checks at a specific calibration gas 
concentration level (i.e. low-, mid-, or high-).
    3.10 Gas Analyzer means the equipment that senses the gas being 
measured and generates an output proportional to its concentration.
    3.11 Interference Check means the test to detect analyzer 
responses to compounds other than the compound of interest, usually 
a gas present in the measured gas stream, that is not adequately 
accounted for in the calibration procedure and may cause measurement 
bias.
    3.12 Low-Concentration Analyzer means any analyzer that operates 
with a calibration span of 20 ppm NOX or lower. Each 
analyzer model used routinely to measure low NOX 
concentrations must pass a Manufacturer's Stability Test (MST). A 
MST subjects the analyzer to a range of potential effects to 
demonstrate its stability following the procedures provided in 40 
CFR 53.23, 53.55, and 53.56 and provides the information in a 
summary format. A copy of this information must be included in each 
test report. Table 7E-5 lists the criteria to be met.
    3.13 Measurement System means all of the equipment used to 
determine the NOX concentration. The measurement system 
comprises six major subsystems: Sample acquisition, sample 
transport, sample conditioning, calibration gas manifold, gas 
analyzer, and data recorder.
    3.14 Response Time means the time it takes the measurement 
system to respond to a change in gas concentration occurring at the 
sampling point when the system is operating normally at its target 
sample flow rate or dilution ratio.
    3.15 Run means a series of gas samples taken successively from 
the stack or duct. A test normally consists of a specific number of 
runs.
    3.16 System Bias means the difference between a calibration gas 
measured in direct calibration mode and in system calibration mode. 
System bias is determined before and after each run at the low- and 
mid- or high-concentration levels. For dilution-type systems, pre- 
and post-run system calibration error is measured, rather than 
system bias.
    3.17 System Calibration Error applies to dilution-type systems 
and means the difference between the measured concentration of low-, 
mid-, or high-level calibration gas and the certified concentration 
for each gas when introduced in system calibration mode. For 
dilution-type systems, a 3-point system calibration error test is 
conducted in lieu of the analyzer calibration error test, and 2-
point system calibration error tests are conducted in lieu of system 
bias tests.
    3.18 System Calibration Mode means introducing the calibration 
gases into the measurement system at the probe, upstream of the 
filter and all sample conditioning components.
    3.19 Test refers to the series of runs required by the 
applicable regulation.

4.0 Interferences

    Note that interferences may vary among instruments and that 
instrument-specific interferences must be evaluated through the 
interference test.

5.0 Safety

    What safety measures should I consider when using this method? 
This method may require you to work with hazardous materials and in 
hazardous conditions. We encourage you to establish safety 
procedures before using the method. Among other precautions, you 
should become familiar with the safety recommendations in the gas 
analyzer user's manual. Occupational Safety and Health 
Administration (OSHA) regulations concerning cylinder and noxious 
gases may apply. Nitric oxide and NO2 are toxic and 
dangerous gases. Nitric oxide is immediately converted to 
NO2 upon reaction with air. Nitrogen dioxide is a highly 
poisonous and insidious gas. Inflammation of the lungs from exposure 
may cause only slight pain or pass unnoticed, but the resulting 
edema several days later may cause death. A concentration of 100 ppm 
is dangerous for even a short exposure, and 200 ppm may be fatal. 
Calibration gases must be handled with utmost care and with adequate 
ventilation. Emission-level exposure to these gases should be 
avoided.

6.0 Equipment and Supplies

    The performance criteria in this method will be met or exceeded 
if you are properly using equipment designed for this application.
    6.1 What do I need for the measurement system? You may use any 
equipment and supplies meeting the following specifications.
    (1) Sampling system components that are not evaluated in the 
system bias or system calibration error test must be glass, Teflon, 
or stainless steel. Other materials are potentially acceptable, 
subject to approval by the Administrator.
    (2) The interference, calibration error, and system bias 
criteria must be met.
    (3) Sample flow rate must be maintained within 10 percent of the 
flow rate at which the system response time was measured.
    (4) All system components (excluding sample conditioning 
components, if used) must maintain the sample temperature above the 
moisture dew point.
    Section 6.2 provides example equipment specifications for a 
NOX measurement system. Figure 7E-1 is a diagram of an 
example dry basis measurement system that is likely to meet the 
method requirements and is provided as guidance. For wet-basis 
systems, you may use alternative equipment and supplies as needed 
(some of which are described in Section 6.2), provided that the 
measurement system meets the applicable performance specifications 
of this method.
    6.2 Measurement System Components
    6.2.1 Sample Probe. Glass, stainless steel, or other approved 
material, of sufficient length to traverse the sample points.
    6.2.2 Particulate Filter. An in-stack or out-of-stack filter. 
The filter media must be included in the system bias test and made 
of material that is non-reactive to the gas being sampled. This 
particulate filter requirement may be waived in applications where 
no significant particulate matter is expected

[[Page 28091]]

(e.g., for emission testing of a combustion turbine firing natural 
gas).
    6.2.3 Sample Line. The sample line from the probe to the 
conditioning system/sample pump should be made of Teflon or other 
material that does not absorb or otherwise alter the sample gas. For 
a dry-basis measurement system (as shown in Figure 7E-1), the 
temperature of the sample line must be maintained at a sufficiently 
high level to prevent condensation before the sample conditioning 
components. For wet-basis measurement systems, the temperature of 
the sample line must be maintained at a sufficiently high level to 
prevent condensation before the analyzer.
    6.2.4 Conditioning Equipment. For dry basis measurements, a 
condenser, dryer or other suitable device is required to remove 
moisture continuously from the sample gas. Any equipment needed to 
heat the probe or sample line to avoid condensation prior to the 
sample conditioning component is also required.
    For wet basis systems, you must keep the sample above its dew 
point either by: (1) Heating the sample line and all sample 
transport components up to the inlet of the analyzer (and, for hot-
wet extractive systems, also heating the analyzer) or (2) by 
diluting the sample prior to analysis using a dilution probe system. 
The components required to do either of the above are considered to 
be conditioning equipment.
    6.2.5 Sampling Pump. For systems similar to the one shown in 
Figure 7E-1, a leak-free pump is needed to pull the sample gas 
through the system at a flow rate sufficient to minimize the 
response time of the measurement system. The pump may be constructed 
of any material that is non-reactive to the gas being sampled. For 
dilution-type measurement systems, an ejector pump (eductor) is used 
to create a vacuum that draws the sample through a critical orifice 
at a constant rate.
    6.2.6 Calibration Gas Manifold. Prepare a system to allow the 
introduction of calibration gases either directly to the gas 
analyzer in direct calibration mode or into the measurement system, 
at the probe, in system calibration mode, or both, depending upon 
the type of system used. In system calibration mode, the system 
should be able to block the sample gas flow and flood the sampling 
probe. Alternatively, calibration gases may be introduced at the 
calibration valve following the probe. Maintain a constant pressure 
in the gas manifold. For in-stack dilution-type systems, a gas 
dilution subsystem is required to transport large volumes of 
purified air to the sample probe and a probe controller is needed to 
maintain the proper dilution ratio.
    6.2.7 Sample Gas Manifold. For the type of system shown in 
Figure 7E-1, the sample gas manifold diverts a portion of the sample 
to the analyzer, delivering the remainder to the by-pass discharge 
vent. The manifold should also be able to introduce calibration 
gases directly to the analyzer (except for dilution-type systems). 
The manifold must be made of material that is non-reactive to the 
gas sampled or the calibration gas and be configured to safely 
discharge the bypass gas.
    6.2.8 NOX Analyzer. An instrument that continuously measures 
NOX in the gas stream and meets the applicable 
specifications in Section 13.0. An analyzer that operates on the 
principle of chemiluminescence with an NO2 to NO 
converter is one example of an analyzer that has been used 
successfully in the past. Analyzers operating on other principles 
may also be used provided the performance criteria in Section 13.0 
are met.
    6.2.8.1 Dual Range Analyzers. For certain applications, a wide 
range of gas concentrations may be encountered, necessitating the 
use of two measurement ranges. Dual-range analyzers are readily 
available for these applications. These analyzers are often equipped 
with automated range-switching capability, so that when readings 
exceed the full-scale of the low measurement range, they are 
recorded on the high range. As an alternative to using a dual-range 
analyzer, you may use two segments of a single, large measurement 
scale to serve as the low and high ranges. In all cases, when two 
ranges are used, you must quality-assure both ranges using the 
proper sets of calibration gases. You must also meet the 
interference, calibration error, system bias, and drift checks. 
However, we caution that when you use two segments of a large 
measurement scale for dual range purposes, it may be difficult to 
meet the performance specifications on the low range due to signal-
to-noise ratio considerations.
    6.2.8.2 Low Concentration Analyzer. When the calibration span is 
less than or equal to 20 ppmv, the manufacturer's stability test 
(MST) is required. See Table 7E-5.
    6.2.9 Data Recording. A strip chart recorder, computerized data 
acquisition system, digital recorder, or data logger for recording 
measurement data may be used.

7.0 Reagents and Standards

    7.1 Calibration Gas. What calibration gases do I need? Your 
calibration gas must be NO in nitrogen and certified (or 
recertified) within an uncertainty of 2.0 percent in accordance with 
``EPA Traceability Protocol for Assay and Certification of Gaseous 
Calibration Standards'' September 1997, as amended August 25, 1999, 
EPA-600/R-97/121. Blended gases meeting the Traceability Protocol 
are allowed if the additional gas components are shown not to 
interfere with the analysis. The calibration gas must not be used 
after its expiration date.
    Except for applications under part 75 of this chapter, it is 
acceptable to prepare calibration gas mixtures from EPA Traceability 
Protocol gases in accordance with Method 205 in M to part 51 of this 
chapter. For part 75 applications, the use of Method 205 is subject 
to the approval of the Administrator. The goal and recommendation 
for selecting calibration gases is to bracket the sample 
concentrations.
    The following calibration gas concentrations are required:
    7.1.1 High-Level Gas. This concentration sets the calibration 
span and results in measurements being 20 to 100 percent of the 
calibration span.
    7.1.2 Mid-Level Gas. 40 to 60 percent of the calibration span.
    7.1.3 Low-Level Gas. Less than 20 percent of the calibration 
span.
    7.1.4 Converter Efficiency Gas.What reagents do I need for the 
converter efficiency test? The converter efficiency gas for the test 
described in Section 8.2.4.1 must have a concentration of 
NO2 that is between 40 and 60 ppmv. For the alternative 
converter efficiency tests in Section 16.2, NO is required. In 
either case, the test gas must be prepared according to the EPA 
Traceability Protocol.
    7.2 Interference Check. What reagents do I need for the 
interference check? Use the appropriate test gases listed in Table 
7E-3 (i.e., the potential interferents for the test facility, as 
identified by the instrument manufacturer) to conduct the 
interference check.

8.0 Sample Collection, Preservation, Storage, and Transport

Emission Test Procedure

    Since you are allowed to choose different options to comply with 
some of the performance criteria, it is your responsibility to 
identify the specific options you have chosen, to document that the 
performance criteria for that option have been met, and to identify 
any deviations from the method.
    8.1 What sampling site and sampling points do I select?
    8.1.1 Unless otherwise specified in an applicable regulation or 
by the Administrator, when this method is used to determine 
compliance with an emission standard, conduct a stratification test 
as described in Section 8.1.2 to determine the sampling traverse 
points to be used. For performance testing of continuous emission 
monitoring systems, follow the sampling site selection and traverse 
point layout procedures described in the appropriate performance 
specification or applicable regulation (e.g., Performance 
Specification 2 in appendix B to this part).
    8.1.2 Determination of Stratification. To test for 
stratification, use a probe of appropriate length to measure the 
NOX (or pollutant of interest) concentration at twelve 
traverse points located according to Table 1-1 or Table 1-2 of 
Method 1. Alternatively, you may measure at three points on a line 
passing through the centroidal area. Space the three points at 16.7, 
50.0, and 83.3 percent of the measurement line. Sample for a minimum 
of twice the system response time (see Section 8.2.6) at each 
traverse point. Calculate the individual point and mean 
NOX concentrations. If the concentration at each traverse 
point differs from the mean concentration for all traverse points by 
no more than: (a)  5.0 percent of the mean 
concentration; or (b)  0.5 ppm (whichever is less 
restrictive), the gas stream is considered unstratified and you may 
collect samples from a single point that most closely matches the 
mean. If the 5.0 percent or 0.5 ppm criterion is not met, but the 
concentration at each traverse point differs from the mean 
concentration for all traverse points by no more than: (a) < plus-
minus> 10.0 percent of the mean; or (b)  1.0 ppm 
(whichever is less restrictive), the gas stream is considered to be 
minimally stratified, and you may take samples from three points. 
Space the three points at 16.7, 50.0, and 83.3 percent of the 
measurement line. Alternatively, if a twelve

[[Page 28092]]

point stratification test was performed and the emissions shown to 
be minimally stratified (all points within  10.0 percent 
of their mean or within  1.0 ppm), and if the stack 
diameter (or equivalent diameter, for a rectangular stack or duct) 
is greater than 2.4 meters (7.8 ft), then you may use 3-point 
sampling and locate the three points along the measurement line 
exhibiting the highest average concentration during the 
stratification test, at 0.4, 1.0 and 2.0 meters from the stack or 
duct wall. If the gas stream is found to be stratified because the 
10.0 percent or 1.0 ppm criterion for a 3-point test is not met, 
locate twelve traverse points for the test in accordance with Table 
1-1 or Table 1-2 of Method 1.
    8.2 Initial Measurement System Performance Tests. What initial 
performance criteria must my system meet before I begin collecting 
samples? Before measuring emissions, perform the following 
procedures:
    (a) Calibration gas verification,
    (b) Measurement system preparation,
    (c) Calibration error test,
    (d) NO2 to NO conversion efficiency test, if 
applicable,
    (e) System bias check,
    (f) System response time test, and
    (g) Interference check
    8.2.1 Calibration Gas Verification. How must I verify the 
concentrations of my calibration gases? Obtain a certificate from 
the gas manufacturer and confirm that the documentation includes all 
information required by the Traceability Protocol. Confirm that the 
manufacturer certification is complete and current. Ensure that your 
calibration gases certifications have not expired. This 
documentation should be available on-site for inspection. To the 
extent practicable, select a high-level gas concentration that will 
result in the measured emissions being between 20 and 100 percent of 
the calibration span.
    8.2.2 Measurement System Preparation. How do I prepare my 
measurement system? Assemble, prepare, and precondition the 
measurement system according to your standard operating procedure. 
Adjust the system to achieve the correct sampling rate or dilution 
ratio (as applicable).
    8.2.3 Calibration Error Test. How do I confirm my analyzer 
calibration is correct? After you have assembled, prepared and 
calibrated your sampling system and analyzer, you must conduct a 3-
point analyzer calibration error test (or a 3-point system 
calibration error test for dilution systems) before the first run 
and again after any failed system bias test (or 2-point system 
calibration error test for dilution systems) or failed drift test. 
Introduce the low-, mid-, and high-level calibration gases 
sequentially. For non-dilution-type measurement systems, introduce 
the gases in direct calibration mode. For dilution-type measurement 
systems, introduce the gases in system calibration mode.
    (1) For non-dilution systems, you may adjust the system to 
maintain the correct flow rate at the analyzer during the test, but 
you may not make adjustments for any other purpose. For dilution 
systems, you must operate the measurement system at the appropriate 
dilution ratio during all system calibration error checks, and may 
make only the adjustments necessary to maintain the proper ratio.
    (2) Record the analyzer's response to each calibration gas on a 
form similar to Table 7E-1. For each calibration gas, calculate the 
analyzer calibration error using Equation 7E-1 in Section 12.2 or 
the system calibration error using Equation 7E-3 in Section 12.4 (as 
applicable). The calibration error specification in Section 13.1 
must be met for the low-, mid-, and high-level gases. If the 
calibration error specification is not met, take corrective action 
and repeat the test until an acceptable 3-point calibration is 
achieved.
    8.2.4 NO2 to NO Conversion Efficiency Test. Before 
each field test, you must conduct an NO2 to NO conversion 
efficiency test if your system converts NO2 to NO before 
analyzing for NOX. Follow the procedures in Section 
8.2.4.1, or 8.2.4.2. If desired, the converter efficiency factor 
derived from this test may be used to correct the test results for 
converter efficiency if the NO2 fraction in the measured 
test gas is known. Use Equation 7E-8 in Section 12.8 for this 
correction.
    8.2.4.1 Introduce a concentration of 40 to 60 ppmv 
NO2 to the analyzer in direct calibration mode and record 
the NOX concentration displayed by the analyzer. If a 
dilution-system is used, introduce the NO2 calibration 
gas at a point before the dilution takes place. Calculate the 
converter efficiency using Equation 7E-7 in Section 12.7. The 
specification for converter efficiency in Section 13.5 must be met. 
The user is cautioned that state-of-the-art NO2 
calibration gases may not be sufficiently stable and thus make it 
more difficult to pass the 90 percent conversion efficiency 
requirement. The NO2 must be prepared according to the 
EPA Traceability Protocol and have an accuracy within 2.0 percent.
    8.2.4.2 Alternatively, either of the procedures for determining 
conversion efficiency using NO in Section 16.2 may be used.
    8.2.5 Initial System Bias and System Calibration Error Checks. 
Before sampling begins, determine whether the high-level or mid-
level calibration gas best approximates the emissions and use it as 
the upscale gas. Introduce the upscale gas at the probe upstream of 
all sample conditioning components in system calibration mode. 
Record the time it takes for the measured concentration to increase 
to a value that is within 95 percent or 0.5 ppm (whichever is less 
restrictive) of the certified gas concentration. Continue to observe 
the gas concentration reading until it has reached a final, stable 
value. Record this value on a form similar to Table 7E-2.
    (1) Next, introduce the low-level gas in system calibration mode 
and record the time required for the concentration response to 
decrease to a value that is within 5.0 percent or 0.5 ppm (whichever 
is less restrictive) of the certified low-range gas concentration. 
If the low-level gas is a zero gas, use the procedures described 
above and observe the change in concentration until the response is 
0.5 ppm or 5.0 percent of the upscale gas concentration (whichever 
is less restrictive).
    (2) Continue to observe the low-level gas reading until it has 
reached a final, stable value and record the result on a form 
similar to Table 7E-2. Operate the measurement system at the normal 
sampling rate during all system bias checks. Make only the 
adjustments necessary to achieve proper calibration gas flow rates 
at the analyzer.
    (3) From these data, calculate the measurement system response 
time (see Section 8.2.6) and then calculate the initial system bias 
using Equation 7E-2 in Section 12.3. For dilution systems, calculate 
the system calibration error in lieu of system bias using equation 
7E-3 in Section 12.4. See Section 13.2 for acceptable performance 
criteria for system bias and system calibration error. If the 
initial system bias (or system calibration error) specification is 
not met, take corrective action. Then, you must repeat the 
applicable calibration error test from Section 8.2.3 and the initial 
system bias (or 2-point system calibration error) check until 
acceptable results are achieved, after which you may begin sampling.

    (Note: For dilution-type systems, data from the 3-point system 
calibration error test described in Section 8.2.3 may be used to 
meet the initial 2-point system calibration error test requirement 
of this section, if the calibration gases were injected as described 
in this section, and if response time data were recorded).

    8.2.6 Measurement System Response Time. As described in section 
8.2.5, you must determine the measurement system response time 
during the initial system bias (or 2-point system calibration error) 
check. Observe the times required to achieve 95 percent of a stable 
response for both the low-level and upscale gases. The longer 
interval is the response time.
    8.2.7 Interference Check. Conduct an interference response test 
of the gas analyzer prior to its initial use in the field. If you 
have multiple analyzers of the same make and model, you need only 
perform this alternative interference check on one analyzer. You may 
also meet the interference check requirement if the instrument 
manufacturer performs this or similar check on the same make and 
model of analyzer that you use and provides you with documented 
results.
    (1) You may introduce the appropriate interference test gases 
(that are potentially encountered during a test, see examples in 
Table 7E-3) into the analyzer (or measurement system for dilution-
type systems) separately or as mixtures. This test must be performed 
both with and without NOX (NO and NO2) (the 
applicable pollutant gas). For analyzers measuring NOX 
greater than 20 ppm, use a calibration gas with an NOX 
concentration of 80 to 100 ppm and set this concentration equal to 
the calibration span. For analyzers measuring less than 20 ppm 
NOX, select an NO concentration for the calibration span 
that reflects the emission levels at the sources to be tested, and 
perform the interference check at that level. Measure the total 
interference response of the analyzer to these gases in ppmv. Record 
the responses and determine the interference using Table 7E-4. The 
specification in Section 13.4 must be met.
    (2) A copy of this data, including the date completed and signed 
certification, must be

[[Page 28093]]

available for inspection at the test site and included with each 
test report. This interference test is valid for the life of the 
instrument unless major analytical components (e.g., the detector) 
are replaced. If major components are replaced, the interference gas 
check must be repeated before returning the analyzer to service. The 
tester must ensure that any specific technology, equipment, or 
procedures that are intended to remove interference effects are 
operating properly during testing.
    8.3 Dilution-Type Systems--Special Considerations. When a 
dilution-type measurement system is used, there are three important 
considerations that must be taken into account to ensure the quality 
of the emissions data. First, the critical orifice size and dilution 
ratio must be selected properly so that the sample dew point will be 
below the sample line and analyzer temperatures. Second, a high-
quality, accurate probe controller must be used to maintain the 
dilution ratio during the test. The probe controller should be 
capable of monitoring the dilution air pressure, eductor vacuum, and 
sample flow rates. Third, differences between the molecular weight 
of calibration gas mixtures and the stack gas molecular weight must 
be addressed because these can affect the dilution ratio and 
introduce measurement bias.
    8.4 Sample Collection. (1) Position the probe at the first 
sampling point. Purge the system for at least two times the response 
time before recording any data. Then, traverse all required sampling 
points and sample at each point for an equal length of time, 
maintaining the appropriate sample flow rate or dilution ratio (as 
applicable). You must record at least one valid data point per 
minute during the test run. The minimum time you must sample at each 
point is two times the system response time. Usually the test is 
designed for sampling longer than this to better characterize the 
source's temporal variation.
    (2) After recording data for the appropriate period of time at 
the first traverse point, you may move to the next point and 
continue recording, omitting the requirement to wait for two times 
the system response time before recording data at the subsequent 
traverse points. For example, if you use a sampling system with a 
two-minute system response time, initially purge the system for at 
least four minutes, then record a minimum of four one-minute 
averages at each sample point. However, if you remove the probe from 
the stack, you must recondition the sampling system for at least two 
times the system response time prior to your next recording. If the 
average of any run exceeds the calibration span value, the run is 
invalidated.
    (3) You may satisfy the multipoint traverse requirement by 
sampling sequentially using a single-hole probe or a multi-hole 
probe designed to sample at the prescribed points with a flow within 
10 percent of mean flow rate. Notwithstanding, for applications 
under part 75 of this chapter, the use of multi-hole probes is 
subject to the approval of the Administrator.
    8.5 Post-Run System Bias Check and Drift Assessment. How do I 
confirm that each sample I collect is valid? After each run, repeat 
the system bias check or 2-point system calibration error check (for 
dilution systems) to validate the run. Do not make adjustments to 
the measurement system (other than to maintain the target sampling 
rate or dilution ratio) between the end of the run and the 
completion of the post-run system bias or system calibration error 
check. Note that for all post-run system bias or 2-point system 
calibration error checks, you may inject the low-level gas first and 
the upscale gas last, or vice-versa.
    (1) If you do not pass the post-run system bias (or system 
calibration error) check, then the run is invalid. You must diagnose 
and fix the problem and pass another initial 3-point calibration 
error test (see Section 8.2.3) and another system bias (or 2-point 
system calibration error) check (see Section 8.2.5) before repeating 
the run. In these additional bias and calibration error tests, the 
gases may be injected in any order. Record the system bias (or 
system calibration error) check results on a form similar to Table 
7E-2.
    (2) After each run, calculate the low-level and upscale drift, 
using Equation 7E-4 in Section 12.5. If the post-run low- and 
upscale bias (or 2-point system calibration error) checks are 
passed, but the low-or upscale drift exceeds the specification in 
Section 13.3, the run data are valid, but a 3-point calibration 
error test and a system bias (or 2-point system calibration error) 
check must be performed and passed before any more test runs are 
done.
    (3) For dilution systems, data from a 3-point system calibration 
error test may be used to met the pre-run 2-point system calibration 
error requirement for the first run in a test sequence. Also, the 
post-run bias (or 2-point calibration error) check data may be used 
as the pre-run data for the next run in the test sequence at the 
discretion of the tester.
    8.6 Alternative Interference and System Bias Checks (Dynamic 
Spike Procedure). If I want to use the dynamic spike procedure to 
validate my data, what procedure should I follow? Except for 
applications under part 75 of this chapter, you may use the dynamic 
spiking procedure and requirements provided in Section 16.1 during 
each test as an alternative to the interference check and the pre- 
and post-run system bias checks. The calibration error test is still 
required under this option. Use of the dynamic spiking procedure for 
Part 75 applications is subject to the approval of the 
Administrator.
    8.7 Moisture correction. You must determine the moisture content 
of the flue gas and correct the measured gas concentrations to a dry 
basis using Method 4 or other appropriate methods, subject to the 
approval of the Administrator, when the moisture basis (wet or dry) 
of the measurements made with this method is different from the 
moisture basis of either: (1) The applicable emissions limit; or (2) 
the CEMS being evaluated for relative accuracy. Moisture correction 
is also required if the applicable limit is in lb/mmBtu and the 
moisture basis of the Method 7E NOX analyzer is different 
from the moisture basis of the Method 3A diluent gas (CO2 
or O2) analyzer.

9.0 Quality Control

What quality control measures must I take?

    The following table is a summary of the mandatory, suggested, 
and alternative quality assurance and quality control measures and 
the associated frequency and acceptance criteria. All of the QC 
data, along with the sample run data, must be documented and 
included in the test report.

                                             Summary Table of QA/QC
----------------------------------------------------------------------------------------------------------------
      Status         Process or element    QA/QC specification      Acceptance criteria      Checking frequency
----------------------------------------------------------------------------------------------------------------
S................  Identify Data User...  .....................  Regulatory Agency or       Before designing
                                                                  other primary end user     test.
                                                                  of data.
S................  Analyzer Design......  Analyzer resolution    < 2.0% of full-scale range  Manufacturer design.
                                           or sensitivity.
M................  .....................  Interference gas       Sum of responses < =2.5%    ....................
                                           check.                 of calibration span.
                                                                  Alternatively, sum of
                                                                  responses:.
                                                                 < =0.5 ppmv for
                                                                  calibration spans of 5
                                                                  to 10 ppmv..
                                                                 < =0.2 ppmv for
                                                                  calibration spans <  5
                                                                  ppmv..
                                                                 See Table 7E-3...........
M................  Calibration on Gases.  Traceability protocol  Valid certificate
                                           (G1, G2).              required. Uncertainty
                                                                  < =2.0% of tag value.
M................  .....................  High-level gas.......  Equal to the calibration   Each test.
                                                                  span.
M................  .....................  Mid-level gas........  40 to 60% of calibration   Each test.
                                                                  span.
M................  .....................  Low-level gas........  < 20% of calibration span.  Each test.
S................  Data Recorder Design.  Data resolution......  < =0.5% of full-scale       Manufacturer design.
                                                                  range.
S................  Sample Extraction....  Probe material.......  SS or quartz if stack      Each test.
                                                                  >500 [deg]F.

[[Page 28094]]

M................  Sample Extraction....  Probe, filter and      For dry-basis analyzers,   Each run.
                                           sample line            keep sample above the
                                           temperature.           dew point by heating,
                                                                  prior to sample
                                                                  conditioning.
                                                                 For wet-basis analyzers,
                                                                  keep sample above dew
                                                                  point at all times, by
                                                                  heating or dilution..
S................  Sample Extraction....  Calibration valve      SS.......................  Each test.
                                           material.
S................  Sample Extraction....  Sample pump material.  Inert to sample            Each test.
                                                                  constituents.
S................  Sample Extraction....  Manifolding material.  Inert to sample            Each test.
                                                                  constituents.
S................  Moisture Removal.....  Equipment efficiency.  < 5% target compound        Verified through
                                                                  removal.                   system bias check.
S................  Particulate Removal..  Filter inertness.....  Pass system bias check...  Each bias check.
M................  Analyzer &             Analyzer calibration   Within 2.0%    Before initial run
                    Calibration Gas        error (or 3-point      of the calibration span    and after a failed
                    Performance.           system calibration     of the analyzer for the    system bias test or
                                           error for dilution     low-, mid-, and high-      dilution drift
                                           systems).              level calibration gases.   test.
                                                                 Alternative
                                                                  specification: 0.5 ppmv
                                                                  absolute difference..
M................  System Performance...  System bias (or pre-   Within 5.0%    Before and after
                                           and post-run 2-point   of the analyzer            each run.
                                           system calibration     calibration span for low-
                                           error for dilution     scale and upscale
                                           systems).              calibration gases.
                                                                 Alternative
                                                                  specification: 0.5 ppmv
                                                                  absolute difference..
M................  System Performance...  System response time.  Determines minimum         During initial
                                                                  sampling time per point.   sampling system
                                                                                             bias test.
M................  System Performance...  Drift................  3.0% of calibration span   After each test run.
                                                                  for low-level and mid-
                                                                  or high-level gases.
                                                                 Alternative
                                                                  specification: 0.5 ppmv
                                                                  absolute difference..
M................  System Performance...  NO2-NO conversion      >=90% of certified test    Before each test.
                                           efficiency.            gas concentration.
M................  System Performance...  Purge time...........  >=2 times system response  Before starting the
                                                                  time.                      first run and when
                                                                                             probe is removed
                                                                                             from and re-
                                                                                             inserted into the
                                                                                             stack.
M................  System Performance...  Minimum sample time    Two times the system       Each sample point.
                                           at each point.         response time.
M................  System Performance...  Stable sample flow     Within 10% of flow rate    Each run.
                                           rate (surrogate for    established during
                                           maintaining system     system response time
                                           response time).        check.
M................  Sample Point           Stratification test..  All points within:         Prior to first run.
                    Selection.                                   5% of mean
                                                                  for 1-point sampling..
                                                                 10% of mean
                                                                  for 3-point..
                                                                 Alternatively, all points
                                                                  within:.
                                                                 0.5 ppm of
                                                                  mean for 1-point
                                                                  sampling..
                                                                 1.0 ppm of
                                                                  mean for 3-point
                                                                  sampling..
A................  Multiple sample        No. of openings in     Multi-hole probe with      Each run.
                    points                 probe.                 verifiable constant flow
                    simultaneously.                               through all holes within
                                                                  10% of mean flow rate
                                                                  (requires Administrative
                                                                  approval for Part 75).
M................  Data Recording.......  Frequency............  1 minute average.........  During run.
S................  Data Parameters......  Sample concentration   All 1-minute averages      Each run.
                                           range.                 within calibration span.
M................  Data Parameters......  Average concentration  Run average < =calibration  Each run.
                                           for the run.           span.
----------------------------------------------------------------------------------------------------------------
S = Suggested.
M = Mandatory.
A = Alternative.

10.0 Calibration and Standardization

What measurement system calibrations are required?

    (1) The initial 3-point calibration error test as described in 
Section 8.2.3 and the system bias (or system calibration error) 
checks described in Section 8.2.5 are required and must meet the 
specifications in Section 13 before you start the test. Make all 
necessary adjustments to calibrate the gas analyzer and data 
recorder. Then, after the test commences, the system bias or system 
calibration error checks described in Section 8.5 are required 
before and after each run. Your analyzer must be calibrated for all 
species of NOX that it detects. If your analyzer measures 
NO and NO2 separately, then you must use both NO and 
NO2 calibration gases.
    (2) You must include a copy of the manufacturer's certification 
of the calibration gases used in the testing as part of the test 
report. This certification must include the 13 documentation 
requirements in the EPA Traceability Protocol For Assay and 
Certification of Gaseous Calibration Standards, September 1997, as 
amended August 25, 1999. When Method 205 is used to produce diluted 
calibration gases, you must document that the specifications for the 
gas dilution system are met for the test. You must also include the 
date of the most recent dilution system calibration against flow 
standards and the name of the person or manufacturer who carried out 
the calibration in the test report.

[[Page 28095]]

11.0 Analytical Procedures

    Because sample collection and analysis are performed together 
(see Section 8), additional discussion of the analytical procedure 
is not necessary.

12.0 Calculations and Data Analysis

    You must follow the procedures for calculations and data 
analysis listed in this section.
    12.1 Nomenclature. The terms used in the equations are defined 
as follows:

ACE = Analyzer calibration error, percent of calibration span.
BWS = Moisture content of sample gas as measured by 
Method 4 or other approved method, percent/100.
CAvg = Average unadjusted gas concentration indicated by 
data recorder for the test run, ppmv.
CD = Pollutant concentration adjusted to dry conditions, 
ppmv.
CDir = Measured concentration of a calibration gas (low, 
mid, or high) when introduced in direct calibration mode, ppmv.
CGas = Average effluent gas concentration adjusted for 
bias, ppmv.
CM = Average of initial and final system calibration bias 
(or 2-point system calibration error) check responses for the 
upscale calibration gas, ppmv.
CMA = Actual concentration of the upscale calibration 
gas, ppmv.
CO = Average of the initial and final system calibration 
bias (or 2-point system calibration error) check responses from the 
low-level (or zero) calibration gas, ppmv.
CS = Measured concentration of a calibration gas (low, 
mid, or high) when introduced in system calibration mode, ppmv.
CSS = Concentration of NOX measured in the 
spiked sample, ppmv.
CSpike = Concentration of NOX in the undiluted 
spike gas, ppmv.
CCalc = Calculated concentration of NOX in the 
spike gas diluted in the sample, ppmv.
CV = Manufacturer certified concentration of a 
calibration gas (low, mid, or high), ppmv.
CW = Pollutant concentration measured under moist sample 
conditions, wet basis, ppmv.
CS = Calibration span, ppmv.
D = Drift assessment, percent of calibration span.
EffNO2 = NO2 to NO converter efficiency, 
percent.
NOFinal = The average NO concentration observed with the 
analyzer in the NO mode during the converter efficiency test in 
Section 16.2.2, ppmv.
NOXCorr = The NOX concentration corrected for 
the converter efficiency, ppmv.
NOXFinal = The final NOX concentration 
observed during the converter efficiency test in Section 16.2.2, 
ppmv.
NOXPeak = The highest NOX concentration 
observed during the converter efficiency test in Section 16.2.2, 
ppmv.
QSpike = Flow rate of spike gas introduced in system 
calibration mode, L/min.
QTotal = Total sample flow rate during the spike test, L/
min.
R = Spike recovery, percent.
SB = System bias, percent of calibration span.
SBi = Pre-run system bias, percent of calibration span.
SBf = Post-run system bias, percent of calibration span.
SCE = System calibration error, percent of calibration span.
SCEi = Pre-run system calibration error, percent of 
calibration span.
SCEfinal = Post-run system calibration error, percent of 
calibration span.
    12.2 Analyzer Calibration Error. For non-dilution systems, use 
Equation 7E-1 to calculate the analyzer calibration error for the 
low-, mid-, and high-level calibration gases.
[GRAPHIC] [TIFF OMITTED] TR15MY06.001

    12.3 System Bias. For non-dilution systems, use Equation 7E-2 to 
calculate the system bias separately for the low-level and upscale 
calibration gases.
[GRAPHIC] [TIFF OMITTED] TR15MY06.002

    12.4 System Calibration Error. Use Equation 7E-3 to calculate 
the system calibration error for dilution systems. Equation 7E-3 
applies to both the initial 3-point system calibration error test 
and the subsequent 2-point between run tests.
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    12.5 Drift Assessment. Use Equation 7E-4 to separately calculate 
the low-level and upscale drift over each test run. For dilution 
systems, replace ``SBfinal'' and ``SBi'' with 
``SCEfinal'' and ``SCEi'', respectively, to 
calculate and evaluate drift.
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    12.6 Effluent Gas Concentration. For each test run, calculate 
Cavg, the arithmetic average of all valid NOX 
concentration values (e.g., 1-minute averages). Then adjust the 
value of Cavg for bias, using Equation 7E-5.
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    12.7 NO2--NO Conversion Efficiency. If the 
NOX converter efficiency test described in Section 
8.2.4.1 is performed, calculate the efficiency using Equation 7E-7.
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    12.8 NO2--NO Conversion Efficiency Correction. If 
desired, calculate the total NOX concentration with a 
correction for converter efficiency using Equations 7E-8.
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    12.9 Alternative NO2 Converter Efficiency. If the 
alternative procedure of Section 16.2.2 is used, calculate the 
converter efficiency using Equation 7E-9.
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    12.10 Moisture Correction. Use Equation 7E-10 if your 
measurements need to be corrected to a dry basis.
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    12.11 Calculated Spike Gas Concentration and Spike Recovery for 
the Example Alternative Dynamic Spiking Procedure in Section 16.1.3. 
Use Equation 7E-11 to determine the calculated spike gas 
concentration. Use Equation 7E-12 to calculate the spike recovery.
[GRAPHIC] [TIFF OMITTED] TR15MY06.010

[[Page 28096]]

13.0 Method Performance

    13.1 Calibration Error. This specification is applicable to both 
the analyzer calibration error and the 3-point system calibration 
error tests described in Section 8.2.3. At each calibration gas 
level (low, mid, and high) the calibration error must either be 
within  2.0 percent of the calibration span. 
Alternatively, the results are acceptable if [bond]Cdir - 
Cv[bond] or [bond]Cs-Cv[bond] (as 
applicable) is < =0.5 ppmv.
    13.2 System Bias. This specification is applicable to both the 
system bias and 2-point system calibration error tests described in 
Section 8.2.5 and 8.5. The pre- and post-run system bias (or system 
calibration error) must be within  5.0 percent of the 
calibration span for the low-level and upscale calibration gases. 
Alternatively, the results are acceptable if [bond] Cs -
Cdir [bond] is <= 0.5 ppmv or if [bond] Cs- 
Cv [bond] is <= 0.5 ppmv (as applicable).
    13.3 Drift. For each run, the low-level and upscale drift must 
be less than or equal to 3.0 percent of the calibration span. The 
drift is also acceptable if the pre- and post-run bias (or the pre- 
and post-run system calibration error) responses do not differ by 
more than 0.5 ppmv at each gas concentration (i.e. [bond] 
Cs post-run- Cs pre-run [bond] <= 0.5 ppmv).
    13.4 Interference Check. The total interference response (i.e., 
the sum of the interference responses of all tested gaseous 
components) must not be greater than 2.50 percent of the calibration 
span for the analyzer tested. In summing the interferences, use the 
larger of the absolute values obtained for the interferent tested 
with and without the pollutant present. The results are also 
acceptable if the sum of the responses does not exceed 0.5 ppmv for 
a calibration span of 5 to 10 ppmv, or 0.2 ppmv for a calibration 
span <  5 ppmv.
    13.5 NO2 to NO Conversion Efficiency Test (as 
applicable). The NO2 to NO conversion efficiency, 
calculated according to Equation 7E-7 or Equation 7E-9, must be 
greater than or equal to 90 percent.
    13.6 Alternative Dynamic Spike Procedure. Recoveries of both 
pre-test spikes and post-test spikes must be within 100  
10 percent. If the absolute difference between the calculated spike 
value and measured spike value is equal to or less than 0.20 ppmv, 
then the requirements of the ADSC are met.

14.0 Pollution Prevention [Reserved]

15.0 Waste Management [Reserved]

16.0 Alternative Procedures

    16.1 Dynamic Spike Procedure. Except for applications under part 
75 of this chapter, you may use a dynamic spiking procedure to 
validate your test data for a specific test matrix in place of the 
interference check and pre- and post-run system bias checks. For 
part 75 applications, use of this procedure is subject to the 
approval of the Administrator. Best results are obtained for this 
procedure when source emissions are steady and not varying. 
Fluctuating emissions may render this alternative procedure 
difficult to pass. To use this alternative, you must meet the 
following requirements.
    16.1.1 Procedure Documentation. You must detail the procedure 
you followed in the test report, including how the spike was 
measured, added, verified during the run, and calculated after the 
test.
    16.1.2 Spiking Procedure Requirements. The spikes must be 
prepared from EPA Traceability Protocol gases. Your procedure must 
be designed to spike field samples at two target levels both before 
and after the test. Your target spike levels should bracket the 
average sample NOX concentrations. The higher target 
concentration must be less than the calibration span. You must 
collect at least 5 data points for each target concentration. The 
spiking procedure must be performed before the first run and 
repeated after the last run of the test program.
    16.1.3 Example Spiking Procedure. Determine the NO concentration 
needed to generate concentrations that are 50 and 150 percent of the 
anticipated NOX concentration in the stack at the total 
sampling flow rate while keeping the spike flow rate at or below 10 
percent of this total. Use a mass flow meter (accurate within 2.0 
percent) to generate these NO spike gas concentrations at a constant 
flow rate. Use Equation 7E-11 in Section 12.11 to determine the 
calculated spike concentration in the collected sample.
    (1) Prepare the measurement system and conduct the analyzer 
calibration error test as described in Sections 8.2.2 and 8.2.3. 
Following the sampling procedures in Section 8.1, determine the 
stack NOX concentration and use this concentration as the 
average stack concentration (Cavg) for the first spike 
level, or if desired, for both pre-test spike levels. Introduce the 
first level spike gas into the system in system calibration mode and 
begin sample collection. Wait for at least two times the system 
response time before measuring the spiked sample concentration. Then 
record at least five successive 1-minute averages of the spiked 
sample gas. Monitor the spike gas flow rate and maintain at the 
determined addition rate. Average the five 1-minute averages and 
determine the spike recovery using Equation 7E-12. Repeat this 
procedure for the other pre-test spike level. The recovery at each 
level must be within the limits in Section 13.6 before proceeding 
with the test.
    (2) Conduct the number of runs required for the test. Then 
repeat the above procedure for the post-test spike evaluation. The 
last run of the test may serve as the average stack concentration 
for the post-test spike test calculations. The results of the post-
test spikes must meet the limits in Section 13.6.
    16.2 Alternative NO2 to NO Conversion Efficiency 
Procedures. You may use either of the following procedures to 
determine converter efficiency in place of the procedure in Section 
8.2.4.1.
    16.2.1 The procedure for determining conversion efficiency using 
NO in 40 CFR 86.123-78.
    16.2.2 Tedlar Bag Procedure. Perform the analyzer calibration 
error test to document the calibration (both NO and NOX 
modes, as applicable). Fill a Tedlar bag approximately half full 
with either ambient air, pure oxygen, or an oxygen standard gas with 
at least 19.5 percent by volume oxygen content. Fill the remainder 
of the bag with mid-level NO in nitrogen calibration gas. (Note that 
the concentration of the NO standard should be sufficiently high 
that the diluted concentration will be easily and accurately 
measured on the scale used. The size of the bag should be large 
enough to accommodate the procedure and time required).
    (1) Immediately attach the bag to the inlet of the 
NOX analyzer (or external converter if used). In the case 
of a dilution-system, introduce the gas at a point upstream of the 
dilution assembly. Measure the NOX concentration for a 
period of 30 minutes. If the NOX concentration drops more 
than 2 percent absolute from the peak value observed, then the 
NO2 converter has failed to meet the criteria of this 
test. Take corrective action. The highest NOX value 
observed is considered to be NOXPeak. The final 
NOX value observed is considered to be 
NOXfinal.
    (2) If the NOX converter has met the criterion of 
this test, then switch the analyzer to the NO mode (note that this 
may not be required for analyzers with auto-switching). Document the 
average NO concentration for a period of 30 seconds to one minute. 
This average value is NOfinal. Switch the analyzer back 
to the NOX mode and document that the analyzer still 
meets the criteria of not dropping more than 2 percent from the peak 
value.
    (3) In sequence, inject the zero and the upscale calibration gas 
that most closely matches the NOX concentration observed 
during the converter efficiency test. Repeat this procedure in both 
the NO and NOX modes. If the gases are not within 1 
percent of scale of the actual values, reject the converter 
efficiency test and take corrective action. If the gases are within 
this criterion, use Equation 7E-9 to determine the converter 
efficiency. The converter efficiency must meet the specification in 
Section 13.5.
    16.3 Manufacturer's Stability Test. A manufacturer's stability 
test is required for all analyzers that routinely measure emissions 
below 20 ppm and is optional but recommended for other analyzers. 
This test evaluates each analyzer model by subjecting it to the 
tests listed in Table 7E-5 following the procedures in 40 CFR 53.23, 
53.55, and 53.56 to demonstrate its stability. A copy of this 
information in summary format must be included in each test report.

17.0 References

    1. ``ERA Traceability Protocol for Assay and Certification of 
Gaseous Calibration Standards'' September 1997 as amended, ERA-600/
R-97/121.

18.0 Tables, Diagrams, Flowcharts, and Validation Data

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           Table 7E-3.--Interference Check Gas Concentrations
------------------------------------------------------------------------
                                        Sample conditioning type \2\
      Potential interferent       --------------------------------------
                                         Hot wet             Dried
------------------------------------------------------------------------
CO2..............................  5 and 15%           5 and 15%
H2O..............................  25%                 1.%
NO...............................  15 ppmv             15 ppmv
NO2..............................  15 ppmv             15 ppmv
N2O..............................  10 ppmv             10 ppmv
CO...............................  50 ppmv             50 ppmv
NH3..............................  10 ppmv             10 ppmv
CH4..............................  50 ppmv             50 ppmv
SO2..............................  20 ppmv             20 ppmv
H2...............................  50 ppmv             50 ppmv
HCl..............................  10 ppmv             10 ppmv
------------------------------------------------------------------------
(1) Any of the above specific gases can be eliminated or tested at a
  lower level if the manufacturer has provided reliable means for
  limiting or scrubbing that gas to a specified level.
(2) For dilution extractive systems, use the Hot Wet concentrations
  divided by the minimum targeted dilution ratio to be used during the
  test.

Table 7E-4.--Interference Response

 Date of Test:---------------------------------------------------------
 Analyzer Type:--------------------------------------------------------
 Model No.:------------------------------------------------------------
 Serial No:------------------------------------------------------------
 Calibration Span:-----------------------------------------------------

------------------------------------------------------------------------
    Test gas type         Concentration  (ppm)       Analyzer  response
------------------------------------------------------------------------

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

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

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

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

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

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

------------------------------------------------------------------------
Sum of Responses                                   .....................
------------------------------------------------------------------------
% of Calibration Span                              .....................
------------------------------------------------------------------------

                Table 7E-5.--Manufacturer Stability Test
  [Each model must be tested quarterly or once per 50 production units]
------------------------------------------------------------------------
       Test description              Acceptance criteria  (note 1)
------------------------------------------------------------------------
Thermal Stability............  Temperature range when drift does not
                                exceed 3.0% of analyzer range over a 12-
                                hour run when measured with NOX present
Fault Conditions.............  Identify conditions which, when they
                                occur, result in performance which is
                                not in compliance with the
                                Manufacturer's Stability Test criteria.
                                These are to be indicated visually or
                                electrically to alert the operator of
                                the problem.
Insensitivity to Supply        10.0% (or manufacturers
 Voltage Variations.            alternative) variation from nominal
                                voltage must produce a drift of < = 2.0%
                                of calibration span for either zero or
                                concentration >= 80% NOX present.

[[Page 28101]]

Analyzer Calibration Error...  For a low-, medium-, and high-calibration
                                gas, the difference between the
                                manufacturer certified value and the
                                analyzer response in direct calibration
                                mode, no more than 2.0% of calibration
                                span.
------------------------------------------------------------------------
Note 1: If the instrument is to be used as a Low Range analyzer, all
  tests must be performed at a calibration span of 20 ppm or less.

* * * * *

Method 10--Determination of Carbon Monoxide Emissions From Stationary 
Sources (Instrumental Analyzer Procedure)

1.0 Scope and Application

What is Method 10?

    Method 10 is a procedure for measuring carbon monoxide (CO) in 
stationary source emissions using a continuous instrumental 
analyzer. Quality assurance and quality control requirements are 
included to assure that you, the tester, collect data of known 
quality. You must document your adherence to these specific 
requirements for equipment, supplies, sample collection and 
analysis, calculations, and data analysis. This method does not 
completely describe all equipment, supplies, and sampling and 
analytical procedures you will need but refers to other methods for 
some of the details. Therefore, to obtain reliable results, you 
should also have a thorough knowledge of these additional test 
methods which are found in appendix A to this part:
    (a) Method 1--Sample and Velocity Traverses for Stationary 
Sources.
    (b) Method 4--Determination of Moisture Content in Stack Gases.
    (c) Method 7E--Determination of Nitrogen Oxides Emissions from 
Stationary Sources (Instrumental Analyzer Procedure).
    1.1 Analytes. What does this method determine? This method 
measures the concentration of carbon monoxide.

------------------------------------------------------------------------
            Analyte                  CAS No.           Sensitivity
------------------------------------------------------------------------
CO.............................        630-08-0  Typically < 2% of
                                                  Calibration Span.
------------------------------------------------------------------------

    1.2 Applicability. When is this method required? The use of 
Method 10 may be required by specific New Source Performance 
Standards, State Implementation Plans, and permits where CO 
concentrations in stationary source emissions must be measured, 
either to determine compliance with an applicable emission standard 
or to conduct performance testing of a continuous emission 
monitoring system (CEMS). Other regulations may also require the use 
of Method 10.
    1.3 Data Quality Objectives. Refer to Section 1.3 of Method 7E.

2.0 Summary of Method

    In this method, you continuously or intermittently sample the 
effluent gas and convey the sample to an analyzer that measures the 
concentration of CO. You must meet the performance requirements of 
this method to validate your data.

3.0 Definitions

    Refer to Section 3.0 of Method 7E for the applicable 
definitions.

4.0 Interferences

    Substances having a strong absorption of infrared energy may 
interfere to some extent in some analyzers. Instrumental correction 
may be used to compensate for the interference. You may also use 
silica gel and ascarite traps to eliminate the interferences. If 
this option is used, correct the measured gas volume for the carbon 
dioxide (CO2) removed in the trap.

5.0 Safety

    Refer to Section 5.0 of Method 7E.

6.0 Equipment and Supplies

What do I need for the measurement system?

    6.1 Continuous Sampling. Figure 7E-1 of Method 7E is a schematic 
diagram of an acceptable measurement system. The components are the 
same as those in Sections 6.1 and 6.2 of Method 7E, except that the 
CO analyzer described in Section 6.2 of this method must be used 
instead of the analyzer described in Section 6.2 of Method 7E. You 
must follow the noted specifications in Section 6.1 of Method 7E 
except that the requirements to use stainless steel, Teflon, or non-
reactive glass filters do not apply. Also, a heated sample line is 
not required to transport dry gases or for systems that measure the 
CO concentration on a dry basis.
    6.2 Integrated Sampling.
    6.2.1 Air-Cooled Condenser or Equivalent. To remove any excess 
moisture.
    6.2.2 Valve. Needle valve, or equivalent, to adjust flow rate.
    6.2.3 Pump. Leak-free diaphragm type, or equivalent, to 
transport gas.
    6.2.4 Rate Meter. Rotameter, or equivalent, to measure a flow 
range from 0 to 1.0 liter per minute (0.035 cfm).
    6.2.5 Flexible Bag. Tedlar, or equivalent, with a capacity of 60 
to 90 liters (2 to 3 ft3). Leak-test the bag in the 
laboratory before using by evacuating with a pump followed by a dry 
gas meter. When the evacuation is complete, there should be no flow 
through the meter.
    6.3 What analyzer must I use? You must use an instrument that 
continuously measures CO in the gas stream and meets the 
specifications in Section 13.0. The dual-range analyzer provisions 
in Section 6.2.8.1 of Method 7E apply.

7.0 Reagents and Standards

    7.1 Calibration Gas. What calibration gases do I need? Refer to 
Section 7.1 of Method 7E for the calibration gas requirements.
    7.2 Interference Check. What additional reagents do I need for 
the interference check? Use the appropriate test gases listed in 
Table 7E-3 of Method 7E (i.e., potential interferents, as identified 
by the instrument manufacturer) to conduct the interference check.

8.0 Sample Collection, Preservation, Storage, and Transport

Emission Test Procedure

    8.1 Sampling Site and Sampling Points. You must follow Section 
8.1 of Method 7E.
    8.2 Initial Measurement System Performance Tests. You must 
follow the procedures in Section 8.2 of Method 7E. If a dilution-
type measurement system is used, the special considerations in 
Section 8.3 of Method 7E also apply.
    8.3 Interference Check. You must follow the procedures of 
Section 8.2.7 of Method 7E.
    8.4 Sample Collection.
    8.4.1 Continuous Sampling. You must follow the procedures of 
Section 8.4 of Method 7E.
    8.4.2 Integrated Sampling. Evacuate the flexible bag. Set up the 
equipment as shown in Figure 10-1 with the bag disconnected. Place 
the probe in the stack and purge the sampling line. Connect the bag, 
making sure that all connections are leak-free. Sample at a rate 
proportional to the stack velocity. If needed, the CO2 
content of the gas may be determined by using the Method 3 
integrated sample procedures, or by weighing an ascarite 
CO2 removal tube used and computing CO2 
concentration from the gas volume sampled and the weight gain of the 
tube. Data may be recorded on a form similar to Table 10-1.
    8.5 Post-Run System Bias Check, Drift Assessment, and 
Alternative Dynamic Spike Procedure. You must follow the procedures 
in Sections 8.5 and 8.6 of Method 7E.

[[Page 28102]]

9.0 Quality Control

    Follow the quality control procedures in Section 9.0 of Method 
7E.

10.0 Calibration and Standardization

    Follow the procedures for calibration and standardization in 
Section 10.0 of Method 7E.

11.0 Analytical Procedures

    Because sample collection and analysis are performed together 
(see Section 8), additional discussion of the analytical procedure 
is not necessary.

12.0 Calculations and Data Analysis

    You must follow the procedures for calculations and data 
analysis in Section 12.0 of Method 7E, as applicable, substituting 
CO for NOX as applicable.
    12.1 Concentration Correction for CO2 Removal. 
Correct the CO concentration for CO2 removal (if 
applicable) using Eq. 10-1.
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Where:

CAvg = Average gas concentration for the test run, ppm.
CCO stack = Average unadjusted stack gas CO concentration 
indicated by the data recorder for the test run, ppmv.
FCO2 = Volume fraction of CO2 in the sample, 
i.e., percent CO2 from Orsat analysis divided by 100.

13.0 Method Performance

    The specifications for analyzer calibration error, system bias, 
drift, interference check, and alternative dynamic spike procedure 
are the same as in Section 13.0 of Method 7E.

14.0 Pollution Prevention [Reserved]

15.0 Waste Management [Reserved]

16.0 Alternative Procedures

    The dynamic spike procedure and the manufacturer stability test 
are the same as in Sections 16.1 and 16.3 of Method 7E

17.0 References

    1. ``EPA Traceability Protocol for Assay and Certification of 
Gaseous Calibration Standards-- September 1997 as amended, EPA-600/
R-97/121

18.0 Tables, Diagrams, Flowcharts, and Validation Data

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[[Page 28103]]

                         Table 10-1.--Field Data
                          [Integrated sampling]
------------------------------------------------------------------------

------------------------------------------------------------------------
Location: Date:
------------------------------------------------------------------------
Test: Operator:
------------------------------------------------------------------------
           Clock Time              Rotameter Reading       Comments
                                    liters/min (cfm)
------------------------------------------------------------------------

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

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

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

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

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

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

* * * * *

0
4. Appendix A-7 is amended by revising Method 20 to read as follows:

Appendix A-7 to Part 60--Test Methods 19 Through 25E

* * * * *

Method 20--Determination of Nitrogen Oxides, Sulfur Dioxide, and 
Diluent Emissions From Stationary Gas Turbines

1.0 Scope and Application

What is Method 20?

    Method 20 contains the details you must follow when using an 
instrumental analyzer to determine concentrations of nitrogen 
oxides, oxygen, carbon dioxide, and sulfur dioxide in the emissions 
from stationary gas turbines. This method follows the specific 
instructions for equipment and performance requirements, supplies, 
sample collection and analysis, calculations, and data analysis in 
the methods listed in Section 2.0.
    1.1 Analytes. What does this method determine?

------------------------------------------------------------------------
            Analyte                  CAS No.           Sensitivity
------------------------------------------------------------------------
Nitrogen oxides (NOX) as             10102-43-9  Typically < 2% of
 nitrogen dioxide:                                Calibration Span.
    Nitric oxide (NO)..........      10102-44-0
    Nitrogen dioxide NO2.......
Diluent oxygen (O2) or carbon    ..............  Typically < 2% of
 dioxide (CO2).                                   Calibration Span.
Sulfur dioxide (SOX)...........       7446-09-5  Typically < 2% of
                                                  Calibration Span.
------------------------------------------------------------------------

    1.2 Applicability. When is this method required? The use of 
Method 20 may be required by specific New Source Performance 
Standards, Clean Air Marketing rules, and State Implementation Plans 
and permits where measuring SO2, NOX, 
CO2, and/or O2 concentrations in stationary 
gas turbines emissions are required. Other regulations may also 
require its use.
    1.3 Data Quality Objectives. How good must my collected data be? 
Refer to Section 1.3 of Method 7E.

2.0 Summary of Method

    In this method, NOX, O2 (or 
CO2), and SOX are measured using the following 
methods found in appendix A to this part:
    (a) Method 1--Sample and Velocity Traverses for Stationary 
Sources.
    (b) Method 3A--Determination of Oxygen and Carbon Dioxide 
Emissions From Stationary Sources (Instrumental Analyzer Procedure).
    (c) Method 6C--Determination of Sulfur Dioxide Emissions From 
Stationary Sources (Instrumental Analyzer Procedure).
    (d) Method 7E--Determination of Nitrogen Oxides Emissions From 
Stationary Sources (Instrumental Analyzer Procedure).
    (e) Method 19--Determination of Sulfur Dioxide Removal 
Efficiency and Particulate Matter, Sulfur Dioxide, and Nitrogen 
Oxide Emission Rates.

3.0 Definitions

    Refer to Section 3.0 of Method 7E for the applicable 
definitions.

4.0 Interferences

    Refer to Section 4.0 of Methods 3A, 6C, and 7E as applicable.

5.0 Safety

    Refer to Section 5.0 of Method 7E.

6.0 Equipment and Supplies

    The measurement system design is shown in Figure 7E-1 of Method 
7E. Refer to the appropriate methods listed in Section 2.0 for 
equipment and supplies.

7.0 Reagents and Standards

    Refer to the appropriate methods listed in Section 2.0 for 
reagents and standards.

8.0 Sample Collection, Preservation, Storage, and Transport

    8.1 Sampling Site and Sampling Points. Follow the procedures of 
Section 8.1 of Method 7E. For the stratification test in Section 
8.1.2, determine the diluent-corrected pollutant concentration at 
each traverse point.
    8.2 Initial Measurement System Performance Tests. You must refer 
to the appropriate methods listed in Section 2.0 for the measurement 
system performance tests as applicable.
    8.3 Interference Check. You must follow the procedures in 
Section 8.3 of Method 3A or 6C, or Section 8.2.7 of Method 7E (as 
appropriate).
    8.4 Sample Collection. You must follow the procedures of Section 
8.4 of the appropriate methods listed in Section 2.0.
    8.5 Post-Run System Bias Check, Drift Assessment, and 
Alternative Dynamic Spike Procedure. You must follow the procedures 
of Sections 8.5 and 8.6 of the appropriate methods listed in Section 
2.0.

9.0 Quality Control

    Follow quality control procedures in Section 9.0 of Method 7E.

10.0 Calibration and Standardization

    Follow the procedures for calibration and standardization in 
Section 10.0 of Method 7E.

11.0 Analytical Procedures

    Because sample collection and analysis are performed together 
(see Section 8), additional discussion of the analytical procedure 
is not necessary.

12.0 Calculations and Data Analysis

    You must follow the procedures for calculations and data 
analysis in Section 12.0 of the appropriate method listed in Section 
2.0. Follow the procedures in Section 12.0 of Method 19 for 
calculating fuel-specific F factors, diluent-corrected pollutant 
concentrations, and emission rates.

13.0 Method Performance

    The specifications for the applicable performance checks are the 
same as in Section 13.0 of Method 7E.

14.0 Pollution Prevention [Reserved]

15.0 Waste Management [Reserved]

16.0 Alternative Procedures

    Refer to Section 16.0 of the appropriate method listed in 
Section 2.0 for alternative procedures.

[[Page 28104]]

17.0 References

    Refer to Section 17.0 of the appropriate method listed in 
Section 2.0 for references.

18.0 Tables, Diagrams, Flowcharts, and Validation Data

    Refer to Section 18.0 of the appropriate method listed in 
Section 2.0 for tables, diagrams, flowcharts, and validation data.
* * * * *

[FR Doc. 06-4196 Filed 5-12-06; 8:45 am]

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