```

[Federal Register: September 2, 2010 (Volume 75, Number 170)]
[Proposed Rules]               
[Page 53908-53914]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02se10-25]                         

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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 60

[EPA-HQ-OAR-2010-0115; FRL-9195-9]
RIN 2060-AQ23

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

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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

SUMMARY: This action proposes a method for measuring total reduced 
sulfur (TRS) emissions from stationary sources. The EPA is making this 
method available for general use as requested by a number of source 
testing companies since it has been allowed for use in the past on a 
case-by-case basis for kraft pulp mills and refineries. This proposed 
method would offer advantages over

[[Page 53909]]

current methods in that real-time data are acquired and testers are 
allowed to use analyzers and procedures for measuring TRS that are 
commonly used to measure sulfur dioxide (SO2). The proposed 
method would offer an alternative to methods that are currently 
required.

DATES: Comments must be received on or before November 1, 2010.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2010-0115, by one of the following methods:
    http://www.regulations.gov: Follow the on-line 
instructions for submitting comments.
     E-mail: a-and-r-docket@epa.gov, attention Docket ID No. 
EPA-HQ-OAR-2010-0115.
     Fax: (202) 566-9744, attention Docket ID No. EPA-HQ-OAR-
2010-0115.
     Mail: Method 16C for the Determination of Total Reduced 
Sulfur Emissions from Stationary Sources, Docket ID No. EPA-HQ-OAR-
2010-0115. Environmental Protection Agency, Mailcode: 2822T, 1200 
Pennsylvania Ave., NW., Washington, DC 20460. Please include a total of 
two copies.
     Hand Delivery: Deliver your comments to EPA Docket Center, 
Public Reading Room, EPA West, Room 3334, 1301 Constitution Ave., NW., 
Washington, DC 20460, attention Docket ID No. EPA-HQ-OAR-2010-0115. 
Such deliveries are only accepted during the Docket's normal hours of 
operation, and special arrangements should be made for deliveries of 
boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2010-0115. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
http://www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
confidential business information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through http://www.regulations.gov or e-mail. The http://www.regulations.gov Web site 
is an ``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA without 
going through http://www.regulations.gov, your e-mail address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional information about EPA's public 
docket, visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in http://www.regulations.gov or in hard copy at the Method 16C for the 
Determination of Total Reduced Sulfur Emissions from Stationary Sources 
Docket, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW., 
Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 
p.m., Monday through Friday, excluding legal holidays. The telephone 
number for the Public Reading Room is (202) 566-1744, and the telephone 
number for the Air Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Mr. Foston Curtis, U.S. Environmental 
Protection Agency, Office of Air Quality Planning and Standards, Air 
Quality Assessment Division (E143-02), Research Triangle Park, NC 
27711; telephone number: (919) 541-1063; fax number: (919) 541-0516; 
and e-mail address: curtis.foston@epa.gov.

SUPPLEMENTARY INFORMATION: 

I. General Information

A. Does this action apply to me?

    Method 16C applies to the measurement of TRS at kraft pulp mills 
subject to Subpart BB of the New Source Performance Standards (NSPS). 
Currently, Methods 16, 16A, and 16B are allowed at these facilities. 
Method 16C would offer an additional alternative. The methods required 
under Subpart BB are sometimes used in special cases under the 
petroleum refineries NSPS (Subpart J). Method 16C may be applicable to 
other sources regulated by State and local regulations that specify the 
use of Methods 16, 16A, or 16B if desired. The entities that are 
potentially affected by this proposal are included in the following 
table.

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

B. What should I consider as I prepare my comments for EPA?

    1. Submitting CBI. Do not submit this information to EPA through 
http://www.regulations.gov or e-mail. Clearly mark any of the 
information that you claim to be CBI. For CBI information in a disk or 
CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM as 
CBI and then identify electronically within the disk or CD-ROM the 
specific information that is claimed as CBI. In addition to one 
complete version of the comment that includes information claimed as 
CBI, a copy of the comment that does not contain the information 
claimed as CBI must be submitted for inclusion in the public docket. 
Information so marked will not be disclosed except in accordance with 
procedures set forth in 40 CFR part 2.
    2. Tips for Preparing Your Comments. When submitting comments, 
remember to:
     Identify the rulemaking by docket number and other 
identifying information (subject heading, Federal Register date and 
page number).
     Follow directions--The agency may ask you to respond to 
specific questions or organize comments by referencing a Code of 
Federal Regulations (CFR) part or section number.
     Explain why you agree or disagree, suggest alternatives, 
and substitute language for your requested changes.
     Describe any assumptions and provide any technical 
information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
     Provide specific examples to illustrate your concerns, and 
suggest alternatives.
     Explain your views as clearly as possible, avoiding the 
use of profanity or personal threats.
     Make sure to submit your comments by the comment period 
deadline identified.

[[Page 53910]]

C. Where can I get a copy of this document?

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

D. How is this document organized?

    The information in this preamble is organized as follows:

I. General Information
    A. Does this action apply to me?
    B. What should I consider as I prepare my comments for EPA?
    C. Where can I get a copy of this document?
    D. How is this document organized?
II. Background and Summary of Method 16C
III. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health Risks and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations

II. Background and Summary of Method 16C

    The EPA is making Method 16C available for general use as requested 
by a number of source testing companies since it has been allowed on a 
case-by-case basis in the past. The proposed method would offer an 
alternative to methods that are currently required.
    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 described 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 prescribed in Method 6C. In this method, we 
are combining the proven combustion process of Method 16A with the 
analytical techniques currently used for SO2 to form a new, 
improved method for measuring TRS.
    This method would become available as an option for use in 
connection with the New Source Performance Standards for kraft pulp 
mills and possibly petroleum refineries. We have allowed its use in 
approximately four tests over the past 10 years 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 are contained 
in the method to 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.

III. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

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

B. Paperwork Reduction Act

    This action does not impose an information collection burden under 
the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. 
Burden is defined at 5 CFR 1320.3(b). The method being proposed in this 
action does not add information collection requirements but makes an 
additional optional procedure available for use by affected parties.

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 today's 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 today's proposed rule on 
small entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. This 
rulemaking does not impose emission measurement requirements beyond 
those specified in the current regulations, nor does it change any 
emission standard. As such, it will not present a significant economic 
impact on a substantial number of small businesses.
    We continue to be interested in the potential impacts of the 
proposed rule on small entities and welcome comments on issues related 
to such impacts.

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. The 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. This action makes available a new 
optional method for measuring pollutants but adds no new requirements.

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 action simply makes an 
optional test method

[[Page 53911]]

available for affected sources who desire to use it. Thus, Executive 
Order 13132 does not apply to this action. In the spirit of Executive 
Order 13132, and consistent with EPA policy to promote communications 
between EPA and State and local governments, EPA specifically solicits 
comment on this proposed rule from State and local officials.

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 action 
makes available a new optional method for measuring pollutants but adds 
no new requirements. Thus, Executive Order 13175 does not apply to this 
action. EPA specifically solicits additional comment on this proposed 
action from tribal officials.

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

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

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Public Law 104-113 (15 U.S.C. 272 note) 
directs EPA to use voluntary consensus standards in its regulatory 
activities unless to do so would be inconsistent with applicable law or 
otherwise impractical. Voluntary consensus standards are technical 
standards (e.g., materials specifications, test methods, sampling 
procedures, and business practices) that are developed or adopted by 
voluntary consensus standards bodies. NTTAA directs EPA to provide 
Congress, through OMB, explanations when the Agency decides not to use 
available and applicable voluntary consensus standards. This proposed 
rulemaking does not involve technical 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.
    EPA has determined that this proposed 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 rule adds an optional test method and does not cause 
emission increases from regulated sources.

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

List of Subjects in 40 CFR Part 60

    Environmental protection, Air pollution control, Test methods and 
procedures, and Performance specifications.

    Dated: August 26, 2010.
Lisa P. Jackson,
Administrator.

    For the reasons stated in the preamble, the Environmental 
Protection Agency proposes to amend title 40, chapter I of the Code of 
Federal Regulations as follows:

PART 60--STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES

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

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

    2. Add Method 16C to Appendix A-6 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.

[[Page 53912]]

    1.3 Data Quality Objectives. Adherence to the requirements 
described in Method 16C will enhance the quality of the data 
obtained from air pollutant sampling methods.

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 regulated by the 
emission standards, 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. An example measurement system is shown in Figure 16C-1 and 
component parts are discussed below. 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 be sufficient 
when testing a lime kiln under sub-freezing ambient conditions.
    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 
accuracy.
    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 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 CO2 in N2.
    (d) SO2 and O2 in N2.
    (e) SO2/CO2/O2 gas mixture in 
N2.
    (f) CO2/NOX gas mixture in N2.

[[Page 53913]]

    (g) CO2/SO2/NOX gas mixture in 
N2.

For fluorescence-based analyzers, the O2 and 
CO2 concentrations of the calibration gases as introduced 
to the analyzer must be within 1 percent (absolute) O2 
and 1 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 analyers that are used in conjunction with sample 
dilution systems.
    7.4 System Performance Check Gas. You must use hydrogen sulfide 
(100 ppmv or less) in nitrogen, stored in aluminum cylinders with 
concentration certified by the manufacturer.

    Note: Alternatively, hydrogen sulfide 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 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 
achieved.
    8.1.3 System Performance Check. Same as in Method 16A, Section 
8.5, except samples need not be 30 minutes in duration, and the TRS 
sample concentration measured between system performance checks is 
corrected by the average of the two system performance samples. 
System performance checks are conducted before sampling begins 
(optional) and after each sample run (mandatory).
    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  180 
[deg]F).
    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. As an alternative to the initial leak-test, 
the system performance check in Section 8.3.2 may be performed to 
verify the integrity of components.
    8.3.2 Initial System Performance Check. A system performance 
check using the test gas (Section 7.4) is required 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. (This 
preconditioning may not be necessary if the initial system 
performance check is performed.) Begin the sampling and analysis. 
Determine the concentration of SO2 for the prescribed 
sample or run time. Method 16 defines a test run as sampling over a 
period of not less than 3 hours or more than 6 hours when testing 
kraft pulp mills. For Method 16C to be consistent with Method 16, a 
run may be obtained by: (1) sampling for three 60-minute intervals 
or (2) sampling for a 3-hour interval. (Three runs constitute a 
test.)
    8.5 Post-Run Evaluations
    8.5.1 System Performance Check. Perform a post-run system 
performance check (Section 8.5 of Method 16A) 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 13.3. If this limit is 
exceeded, the intervening run or runs are 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 manufacturer 
certified concentration of the gas by more than 3 percent or 0.5 
ppm. If the drift exceeds this limit, the intervening run or runs 
are considered valid, but a new analyzer calibration test must be 
performed and passed before continuing sampling.

9.0 Quality Control

------------------------------------------------------------------------
                             Quality control
         Section                 measure                 Effect
------------------------------------------------------------------------
8.1......................  Sampling equipment   Ensures accurate
                            leak-check and       measurement of sample
                            calibration.         gas flow rate, sample
                                                 volume.
8.1.2....................  Analyzer             Establishes initial
                            calibration error.   calibration accuracy
                                                 within 2%.
8.3.2, 8.5.1.............  System performance   Ensures accuracy of
                            check.               sampling/analytical
                                                 procedure within 20%.
8.5.2....................  Calibration drift    Ensures a stable
                            test.                calibration within 3%.
10.0.....................  Interference check.  Checks for analytical
                                                 interferences.
------------------------------------------------------------------------

[[Page 53914]]

10.0 Calibration

    10.1 Calibrate the system using the gases described in Section 
7.3. The initial 3-point calibration error test as described in 
Section 8.1.2 is required and must meet the specifications in 
Section 13 before you start the test. We recommend you conduct an 
initial system performance test described in Section 8.1.4 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.
BWO = Fraction of volume of water vapor in the gas 
stream.
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.
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 = Sample SO2 concentration, ppmv.
CTRS = Total reduced sulfur concentration corrected for 
system performance and adjusted to dry conditions, ppmv.
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.
[GRAPHIC] [TIFF OMITTED] TP02SE10.008

    12.3 System Performance. Use Equation 16C-2 to calculate the 
system performance.
[GRAPHIC] [TIFF OMITTED] TP02SE10.009

    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 calibration gas response to the original 
response obtained for the gas in the initial analyzer calibration 
test (ACEi).
[GRAPHIC] [TIFF OMITTED] TP02SE10.010

    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 using Equation 16C-4.
[GRAPHIC] [TIFF OMITTED] TP02SE10.011

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 
[bond]Cs-Cv[bond] must be s-Cdir[bond] is n[bond] 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 2.50 
percent of the calibration span. 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 PRE>
```