[Federal Register Volume 77, Number 146 (Monday, July 30, 2012)]
[Rules and Regulations]
[Pages 44488-44494]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-18513]



40 CFR Part 60

[EPA-HQ-OAR-2010-0115; FRL-9701-9]
RIN 2060-AQ23

Method 16C for the Determination of Total Reduced Sulfur 
Emissions From Stationary Sources

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.


SUMMARY: This action promulgates Method 16C for measuring total reduced 
sulfur (TRS) emissions from stationary sources. Method 16C offers the 
advantages of real-time data collection and uses procedures that are 
already in use for measuring other pollutants. Method 16C will be a 
testing option that is used at the discretion of the tester.

DATES: This final rule is effective on July 30, 2012.

ADDRESSES: The EPA has established a docket for this action under 
Docket ID No. EPA-HQ-OAR-2010-0115. All documents in the docket are 
listed in the http://www.regulations.gov index. Although listed in the 
index, some information is not publicly available, e.g., confidential 
business information (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

[[Page 44489]]

available either electronically at www.regulations.gov or in hard copy 
at the Air Docket, EPA/DC, EPA West, Room 3334, 1301 Constitution 
Avenue NW., Washington, DC. The Docket Facility and the Public Reading 
Room are open from 8:30 a.m. to 4:30 p.m., Monday through Friday, 
excluding legal holidays. The telephone number for the Public Reading 
Room is (202) 566-1744, and the telephone number for the Air Docket is 
(202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Mr. Foston Curtis, Office of Air 
Quality Planning and Standards, Air Quality Assessment Division, 
Measurement Technology Group (E143-02), U.S. Environmental Protection 
Agency, Research Triangle Park, North Carolina 27711; telephone number: 
(919) 541-1063; fax number: (919) 541-0516; email address: 


Table of Contents

I. General Information
    A. Does this action apply to me?
    B. Where can I obtain a copy of this action?
    C. Judicial Review
II. Background
III. Summary of Method 16C
IV. Public Comments on Proposed Method 16C
V. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory 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 Risks and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low- Income 
    K. Congressional Review Act

I. General Information

A. Does this action apply to me?

    Method 16C applies to TRS measurement from kraft pulp mills subject 
to Subpart BB of the New Source Performance Standards (NSPS). The 
methods required under Subpart BB for TRS are sometimes used under the 
petroleum refineries NSPS (Subpart J). Method 16C may also be 
applicable to sources regulated by state and local regulations that 
adopt the Subpart BB testing requirements.
    Regulated Entities. Categories and entities potentially affected 
include the following:

                                   NAICS       Examples of regulated
            Category                \a\               entities
Industry........................   322110  Kraft Pulp Mills.
Industry........................   324110  Petroleum Refineries.
\a\ North American Industry Classification System.

    This table is not intended to be exhaustive, but rather to provide 
a guide for readers regarding entities likely to be affected by this 
action. This table lists examples of the types of entities the EPA is 
now aware could potentially be affected by this final action. 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 

B. Where can I obtain a copy of this action?

    In addition to being available in the docket, an electronic copy of 
this rule 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 this final rule is available by filing a petition for review in the 
U.S. Court of Appeals for the District of Columbia Circuit by September 
28, 2012. Under section 307(d)(7)(B) of the CAA, only an objection to 
this final rule that was raised with reasonable specificity during the 
period for public comment can be raised during judicial review. 
Moreover, under section 307(b)(2) of the CAA, the requirements 
established by this action may not be challenged separately in any 
civil or criminal proceedings brought by EPA to enforce these 

II. Background

    Method 16C was proposed in the Federal Register on September 2, 
2010, with a public comment period that ended November 1, 2010. Two 
comment letters were received from the public.

III. Summary of Method 16C

    Method 16C uses the sampling procedures of Method 16A and the 
analytical procedures of Method 6C to measure TRS. Total reduced sulfur 
is defined as hydrogen sulfide, methyl mercaptan, dimethyl sulfide, and 
dimethyl disulfide. As in Method 16A, the sample is collected from the 
source through a heated probe and immediately conditioned in a citrate 
buffer scrubber. The conditioned sample is oxidized in a tube furnace 
to convert TRS to sulfur dioxide (SO2). The oxidized sample 
is then analyzed for SO2 using a real-time SO2 
analyzer as in Method 6C.
    This method may be used as an alternative to Methods 16, 16A, and 
16B for determining TRS. Its use has been allowed on a case-by-case 
basis and, based on our experience, it is a good alternative. Method 
16C offers advantages over currently required methods by supplying 
real-time data in the field using analyzers and procedures that are 
currently used for other pollutants. Performance checks contained in 
the method ensure that bias and calibration precision are periodically 
checked and maintained.
    This rule will not require the use of Method 16C but will allow it 
as an alternative method at the discretion of the user. This method 
does not impact testing stringency; data are collected under the same 
conditions and time intervals as the current methods.

IV. Public Comments on Proposed Method 16C

    Two public comment letters were received on the proposed rule. The 
comments pointed out contradictions in different sections of the method 
for the analyzer calibration error test and the system bias check. In 
one instance, the analyzer calibration acceptance criterion was listed 
as 5 percent and in another place it was listed as 2 percent. The rule 
was corrected to state that 5 percent is the correct criterion for this 
test. For the system bias check, unclear language was amended to 
specifically state that the pre-test bias check is mandatory, not 
optional. An additional comment led to the dropping of the sample 
correction for moisture since it is not needed for most analyzers. The 
public comments are addressed in the Summary of Comments and Responses 
Document that has been added to the docket.

[[Page 44490]]

V. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is not a ``significant regulatory action'' under the 
terms of Executive Order 12866 (58 FR 51735, October 4, 1993) and is, 
therefore, not subject to review under Executive Orders 12866 and 13563 
(76 FR 3821, January 21, 2011).

B. Paperwork Reduction Act

    This action does not impose an information collection burden under 
the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. 
Burden is defined at 5 CFR 1320.3(b). This final rule does not add 
information collection requirements beyond those currently required 
under the applicable regulations. This final rule adds an alternative 
test method that may be used at the discretion of the source.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have a significant economic impact on a substantial 
number of small entities. Small entities include small businesses, 
small organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of this rule on small 
entities, small entity is defined as: (1) A small business as defined 
by the Small Business Administration's (SBA) regulations at 13 CFR 
121.201; (2) a small governmental jurisdiction that is a government of 
a city, county, town, school district or special district with a 
population of less than 50,000; and (3) a small organization that is 
any not-for-profit enterprise which is independently owned and operated 
and is not dominant in its field.
    After considering the economic impacts of this final rule on small 
entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. This final 
rule will not impose any requirements on small entities because Method 
16C is not a required test method but may be used at the discretion of 
the source. Any small entity choosing to use Method 16C would likely do 
so because it is less burdensome or more advantageous than the other 
methods allowed.

D. Unfunded Mandates Reform Act

    This action contains no federal mandates under the provisions of 
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), 2 U.S.C. 
1531-1538 for State, local, or tribal governments or the private 
sector. This action imposes no enforceable duty on any State, local or 
tribal governments or the private sector. Therefore, this action is not 
subject to the requirements of sections 202 or 205 of the UMRA. This 
action is also not subject to the requirements of section 203 of UMRA 
because it contains no regulatory requirements that might significantly 
or uniquely affect small governments. Any small entity choosing to use 
Method 16C would likely do so because it is less burdensome or more 
advantageous than the other methods allowed.

E. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government, as 
specified in Executive Order 13132. This final rule adds Method 16C for 
use as a new alternative method. Thus, Executive Order 13132 does not 
apply to this action.

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

    This action does not have tribal implications, as specified in 
Executive Order 13175 (65 FR 67249, November 9, 2000). This final rule 
provides an additional testing option for measuring pollutants to what 
is currently mandated. It does not add any new requirements and does 
not affect pollutant emissions or air quality. Thus, Executive Order 
13175 does not apply to this action.

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

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

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

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

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Public Law 104-113, 12(d)(15 U.S.C. 272 note) 
directs the EPA to use voluntary consensus standards in its regulatory 
activities unless to do so would be inconsistent with applicable law or 
otherwise impractical. Voluntary consensus standards are technical 
standards (e.g., materials specifications, test methods, sampling 
procedures, and business practices) that are developed or adopted by 
voluntary consensus standards bodies. The NTTAA directs the EPA to 
provide Congress, through OMB, explanations when the Agency decides not 
to use available and applicable voluntary consensus standards.
    This action does not involve technical standards. Therefore, the 
EPA did not consider the use of any voluntary consensus standards.

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

    Executive Order (EO) 12898 (59 FR 7629 (Feb. 16, 1994)) establishes 
federal executive policy on environmental justice. Its main provision 
directs federal agencies, to the greatest extent practicable and 
permitted by law, to make environmental justice part of their mission 
by identifying and addressing, as appropriate, disproportionately high 
and adverse human health or environmental effects of their programs, 
policies, and activities on minority populations and low-income 
populations in the United States.
    The EPA has determined that this final rule will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it does not 
affect the level of protection provided to human health or the 
environment. This final rule does not relax the control measures on 
sources regulated by the rule and, therefore, will not cause emissions 
increases from these sources.

[[Page 44491]]

K. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. The EPA will submit a report containing this rule and 
other required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. A major rule cannot 
take effect until 60 days after it is published in the Federal 
Register. This action is not a ``major rule'' as defined by 5 U.S.C. 
804(2). This rule will be effective on July 30, 2012.

List of Subjects in 40 CFR Part 60

    Administrative practice and procedures, Air pollution control, 
Intergovernmental relations, Reporting and recordkeeping requirements.

    Dated: July 23, 2012.
Lisa P. Jackson,

    For the reasons set out in the preamble, Title 40, Chapter I of the 
Code of Federal Regulations is amended as follows:


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

    Authority:  42 U.S.C. 7401-7601.

2. Amend Appendix A-6 to Part 60 by adding ``Method 16C'' in 
alphanumeric order to read as follows:

Appendix A-6 to Part 60--Test Methods 16 Through 18

* * * * *

Method 16C--Determination of Total Reduced Sulfur Emissions From 
Stationary Sources

1.0 Scope and Application

What is Method 16C?

    Method 16C is a procedure for measuring total reduced sulfur 
(TRS) 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 6C--Determination of Sulfur Dioxide Emissions from 
Stationary Sources (Instrumental Analyzer Procedure)
    (b) Method 7E--Determination of Nitrogen Oxides Emissions from 
Stationary Sources (Instrumental Analyzer Procedure)
    (c) Method 16A--Determination of Total Reduced Sulfur Emissions 
from Stationary Sources (Impinger Technique)
    1.1 Analytes. What does Method 16C determine?

                           Analyte                              CAS No.
Total reduced sulfur including:                                      N/A
  Dimethyl disulfide (DMDS), [(CH3)2S2].....................    62-49-20
  Dimethyl sulfide (DMS), [(CH3)2S].........................     75-18-3
  Hydrogen sulfide (H2S)....................................   7783-06-4
  Methyl mercaptan (MeSH), (CH4S)...........................     74-93-1
Reported as: Sulfur dioxide (SO2)...........................   7449-09-5

    1.2 Applicability. This method is applicable for determining TRS 
emissions from recovery furnaces (boilers), lime kilns, and smelt 
dissolving tanks at kraft pulp mills, and from other sources when 
specified in an applicable subpart of the regulations.
    1.3 Data Quality Objectives. Adherence to the requirements 
described in Method 16C will enhance the quality of the data 

2.0 Summary of Method

    2.1 An integrated gas sample is extracted from the stack. The 
SO2 is removed selectively from the sample using a 
citrate buffer solution. The TRS compounds are then thermally 
oxidized to SO2 and determined as SO2 by an 
instrumental analyzer. This method is a combination of the sampling 
procedures of Method 16A and the analytical procedures of Method 6C 
(referenced in Method 7E), with minor modifications to facilitate 
their use together.

3.0 Definitions

    Analyzer calibration error, Calibration curve, Calibration gas, 
Low-level gas, Mid-level gas, High-level gas, Calibration drift, 
Calibration span, Data recorder, Direct calibration mode, Gas 
analyzer, Interference check, Measurement system, Response time, 
Run, System calibration mode, System performance check, and Test are 
the same as used in Methods 16A and 6C.

4.0 Interferences

    4.1 Reduced sulfur compounds other than those defined as TRS, if 
present, may be measured by this method. Compounds like carbonyl 
sulfide, which is partially oxidized to SO2 and may be 
present in a lime kiln exit stack, would be a positive interferent. 
Interferences may vary among instruments, and instrument-specific 
interferences must be evaluated through the interference check.
    4.2 Particulate matter from the lime kiln stack gas (primarily 
calcium carbonate) can cause a negative bias if it is allowed to 
enter the citrate scrubber; the particulate matter will cause the pH 
to rise and H2S to be absorbed before oxidation. Proper 
use of the particulate filter, described in Section 6.1.3 of Method 
16A, will eliminate this interference.

5.0 Safety

    5.1 Disclaimer. This method may involve hazardous materials, 
operations, and equipment. This test method may not address all of 
the safety problems associated with its use. It is the 
responsibility of the user to establish appropriate safety and 
health practices before performing this test method.
    5.2 Hydrogen Sulfide. Hydrogen sulfide is a flammable, poisonous 
gas with the odor of rotten eggs. Hydrogen sulfide is extremely 
hazardous and can cause collapse, coma, and death within a few 
seconds of one or two inhalations at sufficient concentrations. Low 
concentrations irritate the mucous membranes and may cause nausea, 
dizziness, and headache after exposure. It is the responsibility of 
the user of this test method to establish appropriate safety and 
health practices.

6.0 Equipment and Supplies

What do I need for the measurement system?

    The measurement system is similar to those applicable components 
in Methods 16A and 6C. Modifications to the apparatus are accepted 
provided the performance criteria in Section 13.0 are met.
    6.1 Probe. Teflon tubing, 6.4-mm (\1/4\ in.) diameter, 
sequentially wrapped with heat-resistant fiber strips, a rubberized 
heat tape (plug at one end), and heat-resistant adhesive tape. A 
flexible thermocouple or other suitable temperature measuring device 
must be placed between the Teflon tubing and the fiber strips so 
that the temperature can be monitored to prevent softening of the 
probe. The probe must be sheathed in stainless steel to provide in-
stack rigidity. A series of bored-out stainless steel fittings 
placed at the front of the sheath will prevent moisture and 
particulate from entering between the probe and sheath. A 6.4-mm 
(\1/4\ in.) Teflon elbow (bored out) must be attached to the inlet 
of the probe, and a 2.54 cm (1 in.) piece of Teflon tubing must be 
attached at the open end of the elbow to permit the opening of the 
probe to be turned away from the particulate stream; this will 
reduce the amount of particulate drawn into the sampling train. The 
probe is depicted in Figure 16A-2 of Method 16A.
    6.2 Probe Brush. Nylon bristle brush with handle inserted into a 
3.2-mm (\1/8\ in.) Teflon tubing. The Teflon tubing should be long 
enough to pass the brush through the length of the probe.
    6.3 Particulate Filter. 50-mm Teflon filter holder and a 1- to 
2-[mu]m porosity, Teflon filter (may be available through Savillex 
Corporation, 5325 Highway 101, Minnetonka, Minnesota 55343, or other 
suppliers of filters). The filter holder must be maintained in a hot 
box at a temperature sufficient to prevent moisture condensation. A 
temperature of 121 [deg]C (250 [deg]F) was found to

[[Page 44492]]

be sufficient when testing a lime kiln under sub-freezing ambient 
    6.4 SO2 Scrubber. Three 300-ml Teflon segmented 
impingers connected in series with flexible, thick-walled, Teflon 
tubing. (Impinger parts and tubing may be available through Savillex 
or other suppliers.) The first two impingers contain 100 ml of 
citrate buffer, and the third impinger is initially dry. The tip of 
the tube inserted into the solution should be constricted to less 
than 3 mm (\1/8\ in.) ID and should be immersed to a depth of at 
least 5 cm (2 in.).
    6.5 Combustion Tube. Quartz glass tubing with an expanded 
combustion chamber 2.54 cm (1 in.) in diameter and at least 30.5 cm 
(12 in.) long. The tube ends should have an outside diameter of 0.6 
cm (\1/4\ in.) and be at least 15.3 cm (6 in.) long. This length is 
necessary to maintain the quartz-glass connector near ambient 
temperature and thereby avoid leaks. Alternative combustion tubes 
are acceptable provided they are shown to combust TRS at 
concentrations encountered during tests.
    6.6 Furnace. A furnace of sufficient size to enclose the 
combustion chamber of the combustion tube with a temperature 
regulator capable of maintaining the temperature at 800  
100 [deg]C (1472  180 [deg]F). The furnace operating 
temperature should be checked with a thermocouple to ensure 
    6.7 Sampling Pump. A leak-free pump is required to pull the 
sample gas through the system at a flow rate sufficient to minimize 
the response time of the measurement system and must be constructed 
of material that is non-reactive to the gas it contacts. For 
dilution-type measurement systems, an eductor pump may be used to 
create a vacuum that draws the sample through a critical orifice at 
a constant rate.
    6.8 Calibration Gas Manifold. The calibration gas manifold must 
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 
must be able to flood the sampling probe and vent excess gas. 
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.
    6.9 Sample Gas Manifold. 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. The manifold 
must be made of material that is non-reactive to SO2 and 
be configured to safely discharge the bypass gas.
    6.10 SO2 Analyzer. You must use an instrument that 
uses an ultraviolet, non-dispersive infrared, fluorescence, or other 
detection principle to continuously measure SO2 in the 
gas stream provided it meets the performance specifications in 
Section 13.0.
    6.11 Data Recording. A strip chart recorder, computerized data 
acquisition system, digital recorder, or data logger for recording 
measurement data must be used.

7.0 Reagents and Standards

    Note: Unless otherwise indicated, all reagents must conform to 
the specifications established by the Committee on Analytical 
Reagents of the American Chemical Society. When such specifications 
are not available, the best available grade must be used.

    7.1 Water. Deionized distilled water must conform to ASTM 
Specification D 1193-77 or 91 Type 3 (incorporated by reference--see 
Sec.  60.17). The KMnO4 test for oxidizable organic 
matter may be omitted when high concentrations of organic matter are 
not expected to be present.
    7.2 Citrate Buffer. Dissolve 300 g of potassium citrate (or 284 
g of sodium citrate) and 41 g of anhydrous citric acid in 1 liter of 
water (200 ml is needed per test). Adjust the pH to between 5.4 and 
5.6 with potassium citrate or citric acid, as required.
    7.3 Calibration Gas. Refer to Section 7.1 of Method 7E (as 
applicable) for the calibration gas requirements. Example 
calibration gas mixtures are listed below.
    (a) SO2 in nitrogen (N2).
    (b) SO2 in air.
    (c) SO2 and carbon dioxide (CO2) in 
    (d) SO2 and oxygen (O2) in N2.
    (e) SO2/CO2/O2 gas mixture in 
    (f) CO2/NOX gas mixture in N2.
    (g) CO2/SO2/NOX gas mixture in 

For fluorescence-based analyzers, the O2 and 
CO2 concentrations of the calibration gases as introduced 
to the analyzer must be within 1.0 percent (absolute) O2 
and 1.0 percent (absolute) CO2 of the O2 and 
CO2 concentrations of the effluent samples as introduced 
to the analyzer. Alternatively, for fluorescence-based analyzers, 
use calibration blends of SO2 in air and the nomographs 
provided by the vendor to determine the quenching correction factor 
(the effluent O2 and CO2 concentrations must 
be known). This requirement does not apply to ambient-level 
fluorescence analyzers that are used in conjunction with sample 
dilution systems. Alternatively, H2S in O2 or 
air may be used to calibrate the analyzer through the tube furnace.
    7.4 System Performance Check Gas. You must use H2S 
(100 ppmv or less) stored in aluminum cylinders with the 
concentration certified by the manufacturer. Hydrogen sulfide in 
nitrogen is more stable than H2S in air, but air may be 
used as the balance gas. Note: Alternatively, H2S 
recovery gas generated from a permeation device gravimetrically 
calibrated and certified at some convenient operating temperature 
may be used. The permeation rate of the device must be such that at 
the appropriate dilution gas flow rate, an H2S 
concentration can be generated in the range of the stack gas or 
within 20 percent of the emission standard.
    7.5 Interference Check. Examples of test gases for the 
interference check are listed in Table 7E-3 of Method 7E.

8.0 Sample Collection, Preservation, Storage, and Transport

    8.1 Pre-sampling Tests. Before measuring emissions, perform the 
following procedures:
    (a) Calibration gas verification,
    (b) Calibration error test,
    (c) System performance check,
    (d) Verification that the interference check has been satisfied.
    8.1.1 Calibration Gas Verification. Obtain a certificate from 
the gas manufacturer documenting the quality of the gas. Confirm 
that the manufacturer certification is complete and current. Ensure 
that your calibration gas 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.
    8.1.2 Analyzer Calibration Error Test. After you have assembled, 
prepared, and calibrated your sampling system and analyzer, you must 
conduct a 3-point analyzer calibration error test before the first 
run and again after any failed system performance check or failed 
drift test to ensure the calibration is acceptable. Introduce the 
low-, mid-, and high-level calibration gases sequentially to the 
analyzer in direct calibration mode. For each calibration gas, 
calculate the analyzer calibration error using Equation 16C-1 in 
Section 12.2. The calibration error for the low-, mid-, and high-
level gases must not exceed 5.0 percent or 0.5 ppmv. If the 
calibration error specification is not met, take corrective action 
and repeat the test until an acceptable 3-point calibration is 
    8.1.3 System Performance Check. A system performance check is 
done (1) to validate the sampling train components and procedure 
(prior to testing), and (2) to validate a test run (after a run). 
You must conduct a performance check in the field prior to testing, 
and after each 3-hour run or after three 1-hour runs. A performance 
check consists of sampling and analyzing a known concentration of 
H2S (system performance check gas) and comparing the 
analyzed concentration to the known concentration. To conduct the 
system performance check, mix the system performance check gas 
(Section 7.4) and ambient air, that has been conditioned to remove 
moisture and sulfur-containing gases, in a dilution system such as 
that shown in Figure 16A-3 of Method 16A. Alternatively, ultra-high 
purity (UHP) grade air may be used. Adjust the gas flow rates to 
generate an H2S concentration in the range of the stack 
gas or within 20 percent of the applicable standard and an oxygen 
concentration greater than 1 percent at a total flow rate of at 
least 2.5 liters/min (5.3 ft3/hr). Use Equation 16A-3 from Method 
16A to calculate the concentration of system performance check gas 
generated. Calibrate the flow rate from both gas sources with a soap 
bubble flow meter so that the diluted concentration of 
H2S can be accurately calculated. Alternatively, mass 
flow controllers with documented calibrations may be used if UHP 
grade air is being used. Sample duration should be sufficiently long 
to ensure a stable response from the analyzer.

[[Page 44493]]

Analyze in the same manner as the emission samples. Collect the 
sample through the probe of the sampling train using a manifold or 
other suitable device that will ensure extraction of a 
representative sample. The TRS sample concentration measured between 
system performance checks is corrected by the average of the pre- 
and post-system performance checks.
    8.1.4 Interference Check. Same as in Method 7E, Section 8.2.7.
    8.2 Measurement System Preparation.
    8.2.1 For the SO2 scrubber, measure 100 ml of citrate 
buffer into the first and second impingers; leave the third impinger 
empty. Immerse the impingers in an ice bath, and locate them as 
close as possible to the filter heat box. The connecting tubing 
should be free of loops. Maintain the probe and filter temperatures 
sufficiently high to prevent moisture condensation, and monitor with 
a suitable temperature sensor. Prepare the oxidation furnace and 
maintain at 800  100[deg]C (1472  
    8.2.2 Citrate Scrubber Conditioning Procedure. Condition the 
citrate buffer scrubbing solution by pulling stack gas through the 
Teflon impingers as described in Section 8.4.1.
    8.3 Pretest Procedures. After the complete measurement system 
has been set up at the site and deemed to be operational, the 
following procedures must be completed before sampling is initiated.
    8.3.1 Leak-Check. Appropriate leak-check procedures must be 
employed to verify the integrity of all components, sample lines, 
and connections. For components upstream of the sample pump, attach 
the probe end of the sample line to a manometer or vacuum gauge, 
start the pump and pull a vacuum greater than 50 mm (2 in.) Hg, 
close off the pump outlet, and then stop the pump and ascertain that 
there is no leak for 1 minute. For components after the pump, apply 
a slight positive pressure and check for leaks by applying a liquid 
(detergent in water, for example) at each joint. Bubbling indicates 
the presence of a leak.
    8.3.2 Initial System Performance Check. A system performance 
check using the test gas (Section 7.4) is performed prior to testing 
to validate the sampling train components and procedure.
    8.4 Sample Collection and Analysis.
    8.4.1 After performing the required pretest procedures described 
in Section 8.1, insert the sampling probe into the test port 
ensuring that no dilution air enters the stack through the port. 
Condition the sampling system and citrate buffer solution for a 
minimum of 15 minutes before beginning analysis. Begin sampling and 
analysis. A source test consists of three test runs. A test run 
shall consist of a single sample collected over a 3-hour period or 
three separate 1-hour samples collected over a period not to exceed 
six hours.
    8.5 Post-Run Evaluations.
    8.5.1 System Performance Check. Perform a post-run system 
performance check before replacing the citrate buffer solution and 
particulate filter and before the probe is cleaned. The check 
results must not exceed the 100  20 percent limit set 
forth in Section 13.2. If this limit is exceeded, the intervening 
run is considered invalid. However, if the recovery efficiency is 
not in the 100  20 percent range, but the results do not 
affect the compliance or noncompliance status of the affected 
facility, the Administrator may decide to accept the results of the 
compliance test.
    8.5.2 Calibration Drift. After a run or series of runs, not to 
exceed a 24-hour period after initial calibration, perform a 
calibration drift test using a calibration gas (preferably the level 
that best approximates the sample concentration) in direct 
calibration mode. This drift must not differ from the initial 
calibration error percent by more than 3.0 percent or 0.5 ppm. If 
the drift exceeds this limit, the intervening run or runs are 
considered valid, but a new analyzer calibration error test must be 
performed and passed before continuing sampling.

9.0 Quality Control

                                  Quality control
            Section                   measure               Effect
8.1.2.........................  Analyzer             Establishes initial
                                 calibration error    calibration
                                 test.                accuracy within
8.1.3, 8.5.1..................  System performance   Ensures accuracy of
                                 check.               sampling/
                                                      procedure to 100
8.5.2.........................  Calibration drift    Ensures calibration
                                 test.                drift is within
8.1.4.........................  Interference check.  Checks for
8.3...........................  Sampling equipment   Ensures accurate
                                 leak-check.          measurement of
                                                      sample gas flow
                                                      rate, sample

10.0 Calibration

    10.1 Calibrate the system using the gases described in Section 
7.3. Perform the initial 3-point calibration error test as described 
in Section 8.1.2 before you start the test. The specification in 
Section 13 must be met. Conduct an initial system performance test 
described in Section 8.1.3 as well before the test to validate the 
sampling components and procedures before sampling. After the test 
commences, a system performance check is required after each run. 
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.

11.0 Analytical Procedure

    Because sample collection and analysis are performed together 
(see Section 8.0), additional discussion of the analytical procedure 
is not necessary.

12.0 Calculations and Data Analysis

    12.1 Nomenclature.

ACE = Analyzer calibration error, percent of calibration span.
CD = Calibration drift, percent.
CDir = Measured concentration of a calibration gas (low, 
mid, or high) when introduced in direct calibration mode, ppmv.
CH2S = Concentration of the system performance check gas, 
ppmv H2S.
CM = Average of initial and final system calibration bias 
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 check responses from the low-level (or zero) calibration gas, 
COA = Actual concentration of the low-level calibration 
gas, ppmv.
CS = Measured concentration of the system performance gas 
when introduced in system calibration mode, ppmv H2S.
CV = Manufacturer certified concentration of a 
calibration gas (low, mid, or high), ppmv SO2.
CSO2 = Unadjusted sample SO2 concentration, 
CTRS = Total reduced sulfur concentration corrected for 
system performance, ppmv.
DF = Dilution system (if used) dilution factor, dimensionless.
SP = System performance, percent.

    12.2 Analyzer Calibration Error. Use Equation 16C-1 to calculate 
the analyzer calibration error for the low-, mid-, and high-level 
calibration gases.

[[Page 44494]]

    12.3 System Performance Check. Use Equation 16C-2 to calculate the 
system performance.

    12.4 Calibration Drift. Use Equation 16C-3 to calculate the 
calibration drift at a single concentration level after a run or series 
of runs (not to exceed a 24-hr period) from initial calibration. 
Compare the single-level calibration gas error (ACEn) to the 
original error obtained for that gas in the initial analyzer 
calibration error test (ACEi).

    12.5 TRS Concentration as SO2. For each sample or test 
run, calculate the arithmetic average of SO2 concentration 
values (e.g., 1-minute averages). Then calculate the sample TRS 
concentration by adjusting the average value of CSO2 for 
system performance using Equation 16C-4a if you use a non-zero gas as 
your low-level calibration gas, or Equation 16C-4b if you use a zero 
gas as your low-level calibration gas.

13.0 Method Performance

    13.1 Analyzer Calibration Error. At each calibration gas level 
(low, mid, and high), the calibration error must either not exceed 5.0 
percent of the calibration gas concentration or 
[verbarlm]CDir-Cv[verbarlm] must be <=0.5 ppmv.
    13.2 System Performance. Each system performance check must not 
deviate from the system performance gas concentration by more than 20 
percent. Alternatively, the results are acceptable if 
[verbarlm]Cs-CH2S[verbarlm] is <=0.5 ppmv.
    13.3 Calibration Drift. The calibration drift at the end of any run 
or series of runs within a 24-hour period must not differ by more than 
3.0 percent from the original ACE at the test concentration level or 
[verbarlm]ACEi-ACEn[verbarlm] must not exceed 0.5 ppmv.
    13.4 Interference Check. For the analyzer, the total interference 
response (i.e., the sum of the interference responses of all tested 
gaseous components) must not be greater than 2.5 percent of the 
calibration span. Any interference is 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.

14.0 Pollution Prevention [Reserved]

15.0 Waste Management [Reserved]

16.0 References

1. The references are the same as in Section 16.0 of Method 16, 
Section 17.0 of Method 16A, and Section 17.0 of Method 6C.
2. National Council of the Paper Industry for Air and Stream 
Improvement, Inc,. A Study of TRS Measurement Methods. Technical 
Bulletin No. 434. New York, NY. May 1984. 12p.
3. Margeson, J.H., J.E. Knoll, and M.R. Midgett. A Manual Method for 
TRS Determination. Draft available from the authors. Source Branch, 
Quality Assurance Division, U.S. Environmental Protection Agency, 
Research Triangle Park, NC 27711.

17.0 Tables, Diagrams, Flowcharts, and Validation Data [Reserved]

* * * * *
[FR Doc. 2012-18513 Filed 7-27-12; 8:45 am]