Document ID: EPA-HQ-OAR-2013-0696-0001
Agency: epa
Document Type: Proposed Rule
Title: Performance Specification 18; Specifications and Test Procedures: Gaseous HCl Continuous Emission Monitoring Systems at Stationary Sources
Posted Date: 2014-05-14T04:00Z

[Federal Register Volume 79, Number 93 (Wednesday, May 14, 2014)]
[Proposed Rules]
[Pages 27689-27716]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-10824]

[[Page 27689]]

Vol. 79

Wednesday,

No. 93

May 14, 2014

Part II

Environmental Protection Agency

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40 CFR Part 60

Performance Specification 18--Specifications and Test Procedures for 
Gaseous HCl Continuous Emission Monitoring Systems at Stationary 
Sources; Proposed Rule

  Federal Register / Vol. 79 , No. 93 / Wednesday, May 14, 2014 / 
Proposed Rules  

[[Page 27690]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 60

[EPA-HQ-OAR-2013-0696; FRL-9909-79-OAR]
RIN 2060-5689

Performance Specification 18--Specifications and Test Procedures 
for Gaseous HCl Continuous Emission Monitoring Systems at Stationary 
Sources

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing 
performance specifications and test procedures for hydrogen chloride 
continuous emission monitoring systems to provide sources and 
regulatory agencies with criteria and test procedures for evaluating 
the acceptability of hydrogen chloride continuous emission monitoring 
systems. The proposed specification (Performance Specification 18) 
includes requirements for initial acceptance including instrument 
accuracy and stability assessments. This action also proposes quality 
assurance procedures for hydrogen chloride continuous emission 
monitoring systems used for compliance determination at stationary 
sources. The quality assurance procedures (Procedure 6) specify the 
minimum quality assurance requirements necessary for the control and 
assessment of the quality of continuous emission monitoring systems 
data submitted to the EPA.
    This action would establish consistent requirements for ensuring 
and assessing the quality of data measured by hydrogen chloride 
continuous emission monitoring systems. The affected systems are those 
used for determining compliance with emission standards for hydrogen 
chloride on a continuous basis as specified in an applicable permit or 
regulation. The affected industries and their North American Industry 
Classification System codes are listed in the SUPPLEMENTARY INFORMATION 
section of this preamble.

DATES: Comments. Comments must be received on or before June 13, 2014.
    Public Hearing. The EPA will hold a public hearing on this rule if 
requested. Requests for a hearing must be made by May 27, 2014. 
Requests for a hearing should be made to Ms. Candace Sorrell via email 
at sorrell.candace@epa.gov or by phone at (919) 541-1064. If a hearing 
is requested, it will be held on May 28, 2014 at the EPA facility in 
Research Triangle Park, NC.

ADDRESSES: Comments. Submit your comments, identified by Docket ID No. 
EPA-HQ-OAR-2013-0696, by one of the following methods:
     http://www.regulations.gov: Follow the online instructions 
for submitting comments.
     Email: a-and-r-docket@epa.gov, Attention Docket ID Number 
EPA-HQ-OAR-2013-0696.
     Fax: (202) 566-9744, Attention Docket ID No. EPA-HQ-OAR-
2013-0696.
     Mail: U.S. Postal Service, send comments to: EPA Docket 
Center, William J. Clinton (WJC) West Building, Attention Docket ID 
Number EPA-HQ-OAR-2013-0696, U.S. Environmental Protection Agency, Mail 
code: 28221T, 1200 Pennsylvania Ave. NW., Washington, DC 20460. Please 
include a total of two copies.
     Hand Delivery: U.S. Environmental Protection Agency, WJC 
West Building (Air Docket), Room 3334, 1301 Constitution Ave. NW., 
Washington, DC, 20004, Attention Docket ID Number EPA-HQ-OAR-2013-0696. 
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 Number EPA-HQ-OAR-
2013-0696. The 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 email. The http://www.regulations.gov Web site 
is an ``anonymous access'' system, which means the EPA will not know 
your identity or contact information unless you provide it in the body 
of your comment. If you send an email comment directly to the EPA 
without going through http://www.regulations.gov, your email 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, the 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 the EPA cannot read your comment 
due to technical difficulties and cannot contact you for clarification, 
the EPA may not be able to consider your comment. Electronic files 
should not include special characters or any form of encryption and be 
free of any defects or viruses. For additional information about the 
EPA's public docket, visit the EPA Docket Center homepage at: http://www.epa.gov/epahome/dockets.
    Docket: The EPA has established a docket for this rulemaking under 
Docket ID Number EPA-HQ-OAR-2013-0696. All documents in the docket are 
listed in the 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, is not placed on the Internet and will be 
publicly available only in hard copy. Publicly available docket 
materials are available either electronically in regulations.gov or in 
hard copy at the EPA Docket Center, WJC West Building, Room 3334, 1301 
Constitution Ave. NW., Washington, DC 20004. 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 EPA Docket Center is 
(202) 566-1742.

FOR FURTHER INFORMATION CONTACT: For questions about this proposed 
action, contact Ms. Candace Sorrell, Office of Air Quality Planning and 
Standards, Air Quality Assessment Division (AQAD), Measurement 
Technology Group, U.S. Environmental Protection Agency, Research 
Triangle Park, North Carolina 27709; telephone number: (919) 541-1064; 
fax number: (919) 541-0516; email address: sorrell.candace@epa.gov.

SUPPLEMENTARY INFORMATION: Organization of this Document. The 
information in this preamble is organized as follows:

I. General Information
    A. Does this action apply to me?
    B. Where can I get a copy of this document and other related 
information?
    C. What should I consider as I prepare my comments for the EPA?
II. Background
III. Summary of Proposed Performance Specification 18
    A. What is the purpose of PS-18?
    B. Who must comply with PS-18?
    C. When must I comply with PS-18?
    D. What are the basic requirements of PS-18?
    E. What are the reporting and recordkeeping requirements for PS-
18?
IV. Summary of Proposed Procedure 6
    A. What is the purpose of Procedure 6?
    B. Who must comply with Procedure 6?
    C. When must I comply with Procedure 6?
    D. What are the basic requirements of Procedure 6?

[[Page 27691]]

    E. What are the reporting and recordkeeping requirements for 
Procedure 6?
V. Rationale for Selecting the Proposed Requirements of Performance 
Specification 18 and Procedure 6
    A. What information did we use to develop PS-18 and Procedure 6?
    B. How did we select the requirements for PS-18 and Procedure 6?
    C. Solicitation for Comment
VI. 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 
Populations

I. General Information

A. Does this action apply to me?

    The major entities that would potentially be affected by the 
proposed performance specification 18 (PS-18) and the quality assurance 
(QA) requirements of Procedure 6 for gaseous hydrogen chloride (HCl) 
continuous emission monitoring systems (CEMS) are those entities that 
are required to install a new CEMS, relocate an existing CEMS, or 
replace an existing CEMS under any applicable subpart of 40 CFR parts 
60, 61 or 63. Table 1 of this preamble lists the current federal rules 
by subpart and the corresponding source categories to which the 
proposed PS-18 and Procedure 6 potentially would apply.

 Table 1--Source Categories That Would Be Subject to PS-18 and Procedure
                                    6
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            Subpart(s)                         Source category
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                             40 CFR part 60
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Subpart F.........................  Portland Cement Plants.
Subpart Da........................  Fossil Fuel-Fired Electric Utility,
                                     Industrial-Commercial-
                                     Institutional, and Small Industrial-
                                     Commercial-Institutional Steam
                                     Generating Units.
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                             40 CFR part 63
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Subpart LLL.......................  Portland Cement Manufacturing
                                     Industry.
Subpart UUUUU.....................  Coal- and Oil-fired Electric Utility
                                     Steam Generating Units.
------------------------------------------------------------------------

    The requirements of the proposed PS-18 and Procedure 6 may also 
apply to stationary sources located in a state, district, reservation 
or territory that adopts PS-18 or Procedure 6 in its implementation 
plan.
    Should PS-18 and Procedure 6 ultimately be finalized, we plan to 
amend 40 CFR part 63 subpart UUUUU, National Emission Standards for 
Hazardous Air Pollutants: Coal- and Oil-fired Electric Utility Steam 
Generating Units to offer PS-18 and Procedure 6 as an alternative to 
PS-15 for continuous monitoring of HCl. Note, however, that the 
alternative test method approval process of 63.7(f) is already 
available, even without any regulatory amendment, as a way for affected 
facilities to request approval to use PS-18/Procedure 6 in lieu of PS-
15.
    With regard to 40 CFR part 63, Subpart LLL which affects Portland 
cement manufacturing facilities and includes HCl monitoring 
requirements, should PS-18 and Procedure 6 be finalized, no amendments 
will be needed as Subpart LLL already allows for use of any promulgated 
performance specification for HCl CEMS in 40 CFR part 60, Appendix B.
    Table 2 lists the corresponding North American Industry 
Classification System (NAICS) codes for the source categories listed in 
Table 1 of this preamble.

            Table 2--NAICS for Potentially Regulated Entities
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                       Industry                           NAICS Codes
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Fossil Fuel-Fired Electric Utility Steam Generating               327310
 Units...............................................         \a\ 921150
Portland Cement Manufacturing Plants.................             327310
------------------------------------------------------------------------
\a\ Industry in Indian Country.

    Tables 1 and 2 are not intended to be exhaustive, but rather they 
provide a guide for readers regarding entities potentially affected by 
this action. If you have any questions regarding the potential 
applicability of the proposed PS-18 and test procedures (Procedure 6) 
to a particular entity, consult the person listed in the FOR FURTHER 
INFORMATION CONTACT section.

B. Where can I get a copy of this document and other related 
information?

    In addition to being available in the docket, an electronic copy of 
this action is available on the Internet through the EPA's Technology 
Transfer Network (TTN) Web site, a forum for information and technology 
exchange in various areas of air pollution control. Following signature 
by the EPA Administrator, the EPA will post a copy of this proposed 
action on the TTN's policy and guidance page for newly proposed or 
promulgated rules at: http://www.epa.gov/ttn/oarpg/t3pfpr.html. 
Following publication in the Federal Register, the EPA will post the 
signed proposal and key technical documents

[[Page 27692]]

on the project Web site: http://www.epa.gov/ttn/emc/proposed.html.

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

1. Submitting CBI
    Do not submit information containing CBI to the EPA through http://www.regulations.gov or email. Clearly mark the part or all of the 
information that you claim to be CBI. For CBI information on a disk or 
CD-ROM that you will mail to the 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 comments that includes information claimed as 
CBI, you must submit a copy of the comments that does not contain the 
information claimed as CBI for inclusion in the public docket. If you 
submit a CD-ROM or disk that does not contain CBI, mark the outside of 
the disk or CD-ROM clearly that it does not contain CBI. Information 
not marked as CBI will be included in the public docket and the EPA's 
electronic public docket without prior notice. Information marked as 
CBI will not be disclosed except in accordance with procedures set 
forth in 40 Code of Federal Regulations (CFR) part 2. Send or deliver 
information identified as CBI only to the following address: Roberto 
Morales, OAQPS Document Control Officer (C404-02), OAQPS, U.S. 
Environmental Protection Agency, Research Triangle Park, North Carolina 
27711, Attention Docket ID Number EPA-HQ-OAR-2013-0696.
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. Respond to specific questions and 
organize comments by a 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 or character assassination.
     Make sure to submit your comments by the comment period 
deadline.

II. Background

    The EPA recently promulgated the Portland Cement Maximum Achievable 
Control Technology (MACT) rule (75 FR 54970, September 9, 2010; 78 FR 
10006, February 12, 2013) and the Mercury and Air Toxics Standards 
(MATS) rule (77 FR 9303, February 16, 2012; 78 FR 24075, April 24, 
2013). Both rules specify the use of extractive Fourier Transform 
Infrared Spectroscopy (FTIR) and PS-15 when affected facilities opt or 
are required to continuously measure HCl emissions. To facilitate use 
of alternative technologies to FTIR and aid in measuring the low levels 
of HCl specified in those rules the EPA has developed and is proposing 
these new specifications and quality control (QC) procedures (PS-18 and 
Procedure 6) for HCl CEMS as an alternative to the use of PS-15.
    Multiple technologies are available for HCl emissions monitoring. 
The goals of the proposed PS-18 and Procedure 6 are (1) to allow for 
the use of different HCl CEMS sampling and analytical technologies as 
long as the required performance criteria set out in the performance 
specification (PS) are met; and (2) to establish consistent 
requirements for ensuring and assessing the quality of data measured by 
HCl CEMS.

III. Summary of Proposed Performance Specification 18

A. What is the purpose of PS-18?

    Proposed PS-18 establishes the criteria to evaluate acceptable 
performance of HCl CEMS at the time of installation or soon after and 
when regulations require reevaluation of HCl CEMS performance.

B. Who must comply with PS-18?

    You may comply with PS-18 as an alternative to other HCl CEMS 
performance specifications (e.g., PS-15) allowed under an applicable 
subpart if you use CEMS to monitor HCl emissions from controlled and 
uncontrolled emission sources subject to HCl CEMS requirements under a 
part 60, 61 or 63 regulation.

C. When must I comply with PS-18?

    If you are the owner or operator of existing facilities required to 
install HCl CEMS in compliance with an associated rule, regulation or 
permit, you must comply with PS-18 if you choose and have these 
specifications approved as an alternative to other PS required under an 
applicable subpart [e.g., PS-15]. Equipment and supplies for HCl CEMS 
will vary depending on the measurement technology and equipment 
vendors. If you are the owner or operator of affected HCl CEMS at new 
stationary sources, you must comply with either the HCl CEMS PS [e.g., 
PS-15] required by the associated rule or permit or PS-18 as an 
approved alternative when you install and place into operation the 
affected HCl CEMS.

D. What are the basic requirements of PS-18?

    The proposed PS-18 would require owners and operators subject to 
HCl CEMS requirements to: (1) Select an HCl CEMS that satisfies basic 
equipment control criteria; (2) install your HCl CEMS according to the 
manufacturer's specifications and the requirements set out in PS-18; 
(3) verify that the instrument is functioning properly; (4) calibrate 
and standardize your equipment; and (5) perform PS-18 procedures that 
demonstrate initial performance requirements for the HCl CEMS. A 
summary of the basic requirements is presented below.
1. HCl CEMS Equipment Selection
    As noted in section III.C, PS-18 equipment and supplies for HCl 
CEMS can and will vary depending on the measurement technology and 
equipment vendors you select. The proposed PS-18 describes the typical 
key equipment and supply components found in one or more types of HCl 
CEMS. Extractive HCl CEMS typically include a sample extraction system, 
sample conditioning module, HCl analyzer, diluent analyzer, system 
controller, data recorder, reference gas system and moisture 
measurement system. Hydrogen chloride integrated path-CEMS (HCl IP-
CEMS) typically include source temperature and pressure monitors and an 
optical transmitter and receiver with or without optics to generate 
longer measurement paths in the emission stream.
    The proposed PS-18 defines the differing HCl CEMS equipment 
components and specifies design/operation basic criteria for the 
differing equipment components. For example, (1) for reference gas 
systems, PS-18 specifies that, for extractive CEMS, the system must be 
designed to be able to introduce reference gas flow sufficient to flood 
the sampling probe and prevent entry of gas from the effluent stream; 
and (2) for sample conditioning that, you must operate the module in 
such a way as to keep the particle-free gas sample above the modules, 
PS-18

[[Page 27693]]

specifies dew point temperature of its components. For HCl IP-CEMS, you 
must operate and qualify equipment to measure source gas temperature 
and pressure.
2. CEMS Measurement Location Specifications and Pretest Preparation
    After you have selected the appropriate HCl CEMS for your 
operations, the proposed PS-18 requires that you install the system 
according to the manufacturer's specifications and as specified under 
section 8.0 of PS-18. The proposed PS-18 requires that you install the 
CEMS at an accessible location where the pollutant concentration or 
emission rate measurements are directly representative of the HCl 
emissions or can be corrected to be representative of the emissions 
from the affected facility.
    With regards to HCl CEMS emissions measurement location, the 
proposed PS-18 specifies that it should be (1) at least two equivalent 
diameters downstream of the nearest control device, point of pollution 
generation or other point at which a change of pollutant concentration 
may occur; and (2) at least half an equivalent diameter (calculated 
according to Method 1 in Appendix A-1 to part 60) upstream from the 
effluent exhaust. We are soliciting comment on alternative measurement 
location requirements in this preamble (see section V.C of this 
preamble).
3. HCl CEMS Measurement Range
    After installation, the proposed PS-18 recommends that you check, 
record and document the continuous emissions measurement range of the 
HCl CEMS to verify that the instrument is functioning correctly. 
Performance Specification 18 requires that the data collection device 
output range include zero and the upper limit of the measurement range.
4. HCl CEMS Performance Requirements and Procedures
    After you have installed, set up, verified, and calibrated your HCl 
CEMS, the proposed PS-18 requires that you follow specified performance 
tests and procedures for the initial demonstration of your HCl CEMS and 
subsequent performance evaluations of your HCl CEMS. In general, the 
proposed PS-18 requires that: (1) Technology used to measure gaseous 
HCl provides a distinct response (DR) and addresses any appropriate 
interference correction(s); (2) the relative accuracy (RA) be 
established against a reference method (RM); and (3) dynamic spiking 
(DS) into the CEMS using a National Institute of Standards and 
Technology (NIST) traceable standard may be required to demonstrate 
initial performance at sources with emissions near the detection level 
of the CEMS and for ongoing QA tests. Specific proposed PS-18 test 
procedures are outlined below.
     Interference Test. You must test to detect analyzer 
responses to interferences not adequately accounted for in the 
calibration procedure that may cause measurement bias. The combined 
interference response for the analyzer used for the test must not be 
greater than  3.0 percent of the equivalent HCl 
concentration used for the interference test.
     Beam Intensity Test for Integrated Patch CEMS (IP-CEMS). 
For IP-CEMS, you must establish the light attenuation tolerance of your 
system and demonstrate that the HCl response is independent of the beam 
intensity. The percent difference during the attenuated light 
calibration check must not be more than  3.0 percent of the 
measured concentration with no attenuation used for the test.
     Temperature Measurement Verification Procedure for IP-
CEMS. You must perform a temperature verification test as part of 
initial installation and verification procedures for an IP-CEMS. 
Temperature measurement must agree with a NIST traceable calibrated 
temperature measuring device within 2.8 [deg]C (5.0 [deg]F).
     Pressure Measurement Verification Test for IP-CEMS. You 
must conduct a pressure measurement verification test if you have an 
IP-CEMS. Your pressure monitor must agree with a NIST traceable 
calibrated measurement device within  5 percent or <= 0.12 
kilopascals (0.5 inches of water column), whichever is greater. For 
stack pressure verification, you should select a gauge or monitor that 
conforms to the design requirements of American Society of Mechanical 
Engineers (ASME) standard B40.100-2010, ``Pressure Gauges and Gauge 
Attachments'' (incorporated by reference, see Sec.  60.17).
     Level of Detection (LOD) Determination. You must determine 
the minimum amount of HCl that can be detected above the background in 
an HCl-free representative gas matrix (the LOD). If you choose to 
perform the LOD determination test in a controlled environment, you 
must verify the LOD during the initial field certification test using 
the DS test procedure (included in Appendix A of the PS). You must make 
three independent DS measurements at no more than five times the LOD 
for the detection level verification. If you cannot detect the DS HCl 
at the estimated LOD, you must increase the spike concentration 
incrementally until you establish a field verified detection level 
where the HCl measurement is a minimum of three times the noise for 
zero HCL concentration. The field verified detection level would 
replace the controlled environment LOD and would become the site- or 
installation-specific LOD.
     Response Time (RT) Determination. You must determine the 
average upscale and downscale response time as the response time for 
the system (the RT). This is the time it takes for the measurement 
system, while operating normally, to respond to a known step change in 
gas concentration (from a low- or zero-level to high-level gas 
concentration or vice versa). Stable RT measurements are made when 
measured HCl concentration is within five percent of the spike gas 
concentration (i.e., the measurements must meet the  5 
percent calibration error requirement; see below).
     Calibration Error (CE) Test. The CE test is the mean 
difference between the HCl calibration gas value and the CEMS response 
at each calibration point expressed as a percentage of the span. The CE 
of your HCl CEMS must be less than five percent.
     Seven-Day Calibration Drift (CD) Test. Prior to conducting 
an RA test on your HCl CEMS, you must perform a 7-day CD test. The 
purpose of the 7-day CD test is to verify the ability of the CEMS to 
maintain calibration for each of seven, 24-hour periods. The zero-level 
and high-level drift for each day must be less than five percent of the 
span value. You must pass each day's drift checks for seven days to 
meet this requirement and each drift check must be recorded and 
reported for the 7-day drift check test.
     RA Test. You must determine the RA for your HCl CEMS. As 
noted above, the RA must be established against an RM. The RA is the 
absolute mean difference between the gas concentration determined by 
the CEMS and the value determined by the RM, plus the 2.5 percent error 
confidence coefficient of a series of tests divided by the average of 
the RM or the applicable emission standard.

E. What are the reporting and recordkeeping requirements for PS-18?

    The proposed PS-18 specifies requirements to record and report 
supporting data for test procedures and calculations set out in PS-18. 
For example, for systems that use a gas blender and/or liquid 
evaporative calibrator to deliver HCl gas standards, PS-18 requires 
that you record and report supporting data for these devices,

[[Page 27694]]

including liquid feed calibrations, liquid standard(s) concentration, 
feed rate and gas flow calibrations for all diluent and HCl gas flows. 
The proposed PS-18 also requires that you record and report summaries 
(in tabular form) of the results of CD tests, linearity tests, RT 
tests, CE tests, RA tests and optional spike recovery procedures. 
Additionally, the proposed PS-18 requires that you record and report 
supporting dilution system data and LOD and system limitation 
verification data for installed HCl CEMS.

IV. Summary of Proposed Procedure 6

A. What is the purpose of Procedure 6?

    This proposed procedure specifies the minimum QA requirements 
necessary for the control and assessment of the quality of CEMS data 
submitted to the EPA. The proposed Procedure 6 would have two distinct 
and important purposes. First, the procedure would assess the quality 
of the HCl CEMS data produced by estimating accuracy. Second, the 
procedure would assist in the control and improvement of the quality of 
the CEMS data by implementing QC policies and corrective actions. Both 
of these purposes work together to ensure that data quality is 
acceptable.

B. Who must comply with Procedure 6?

    Under the proposed Procedure 6, if you are responsible for one or 
more CEMS used for HCl compliance monitoring, you would be required to 
meet the minimum requirements of Procedure 6 and are encouraged to 
develop and implement a more extensive QA program or to continue such 
programs where they already exist. The proposed Procedure 6 would apply 
to any HCl CEMS that is subject to PS-18. That is, if you are required 
under an applicable subpart to parts 60, 61, or 63 to install and 
operate an HCl CEMS and you choose to comply with PS-18, you would be 
subject to both PS-18 and Procedure 6.

C. When must I comply with Procedure 6?

    If you are the owner or operator of an affected HCl CEMS, you must 
comply with Procedure 6 when you install and place into operation an 
HCl CEMS that is subject to PS-18 or when an existing HCl CEMS becomes 
subject to PS-18.

D. What are the basic requirements of Procedure 6?

    Requirements are based on proposed PS-18. Procedure 6 includes 
requirements for: (1) QC plan; (2) daily quality, calibration and 
measurement standardization procedures; and (3) data accuracy 
assessment. A summary of the proposed basic requirements is presented 
below.
1. Quality Control Plan
    The proposed Procedure 6 requires that you develop and implement a 
QC plan that includes written procedures and manufacturer's information 
describing in detail complete, step-by-step measures that ensure 
quality data. The QC plan must cover procedures and operations for 
specified activities (e.g., CD checks of HCl CEMS, HCl IP-CEMS emission 
source temperature and pressure accuracy). Records of these written 
procedures must be maintained and available for inspection by 
enforcement agencies. The proposed Procedure 6 requires either revising 
the QC plan or modifying or replacing the CEMS when quality control 
failures occur for two consecutive quarters.
2. Daily Quality Requirements, Calibration and Measurement Procedures
     CD Assessment. You are required to check, record and 
quantify the CD at two concentration values at least once daily in 
accordance with the method prescribed by the manufacturer. The HCl CEMS 
calibration must, at a minimum, be adjusted whenever the daily zero (or 
low-level) CD or daily high-level CD exceeds two times the drift limits 
of the applicable performance specification (e.g., PS-18).
     Beam Intensity Requirement for HCl IP-CEMS. You must 
check, record and quantify the beam intensity of your IP-CEMS at least 
once daily according to manufacturer's specifications and procedures. 
If the HCl CEMS is out-of-control (the beam intensity falls outside of 
the operation range determined by section 11.2 of the proposed PS-18 of 
part 60), you must take the necessary corrective action and verify that 
the issue has been corrected (i.e., by documenting and reporting the 
results of the quality control check procedure following corrective 
action showing the CEMS to be operating within specifications).
     CEMS Data Status During Out-of-Control Period. Procedure 6 
requires that CEMS data obtained during out-of-control periods not be 
used when calculating compliance with an emissions limit or counted 
toward meeting minimum data availability requirements under an 
applicable regulation or permit.
3. Data Accuracy Assessment
    Procedure 6 requires a weekly ``above span linearity'' challenge of 
the monitoring system with a certified calibration value greater than 
your highest expected hourly concentration. The ``above span'' 
reference gas must be introduced to the measurement system at the 
probe. You must record and report the results of this procedure as you 
would for a daily calibration. The ``above span linearity'' challenge 
must fall within 10 percent of the certified value of the reference 
gas.
     Temperature and Pressure Accuracy Assessment. Procedure 6 
requires temperature and pressure accuracy verification for HCl IP-
CEMS. The accuracy of the temperature and pressure measurement systems 
in each HCl IP-CEMS and stack pressure readings used with IP-CEMS data 
need to be verified and recorded at least once each calendar quarter 
(according to procedures in section 11.3 of the proposed PS-18). 
Procedure 6 also requires that measurement instruments or devices used 
to conduct verification of temperature or pressure measurement have an 
accuracy that is traceable to NIST. If the temperature and pressure 
verification exceeds criteria specified in the procedure that indicates 
that the HCl IP-CEMS is out-of-control, you need to take the necessary 
corrective action to eliminate the problem and verify that it has been 
corrected by repeating the failed verification (i.e., by documenting 
and reporting the results of the audit following corrective action 
showing the CEMS to be operating within specifications).
     Concentration Accuracy Auditing Requirements. Procedure 6 
requires that the accuracy of each HCl CEMS be audited at least once 
each calendar quarter by a relative accuracy test audit (RATA), DS 
audit (DSA), a cylinder gas audit (CGA) or other acceptable alternative 
approved by the Administrator. Hydrogen chloride audit gases are 
required to be NIST certified or NIST-traceable. Procedure 6 also 
requires a RATA to be conducted at least once every four calendar 
quarters unless the affected facility is off-line. Procedure 6 would 
require the analysis of RM audit samples, if they are available, 
concurrently with RM tests as specified in the general provisions of 
the applicable part (i.e., based on the part [i.e., part 60, 61, or 63] 
that contains the subpart that requires the owner or operator to 
install and operate an HCl CEMS).
     Excessive Audit Inaccuracy. Procedure 6 requires 
corrective actions to eliminate problem(s) when the CEMS is out-of-
control. The procedure also requires that you verify that you have 
eliminated the problem(s) by documenting and reporting the results of 
the audit following corrective action

[[Page 27695]]

showing the CEMS to be operating within specifications. For purposes of 
excessive audit inaccuracy, a CEMS is considered out-of-control when 
(1) RA is greater than 20 percent of the RM when RMavg is used in the 
denominator to determine RA or greater than 15 percent when the 
equivalent emission standard value in parts per million by volume wet 
(ppmvw) is used in the denominator to determine RA; (2) the RA of the 
DSA is greater than 15 percent if the average spike value is used to 
determine RA or greater than 20 percent of the applicable emission 
standard if the emission standard is used to determine RA; or (3) the 
error determined by the CGA is greater than five percent of span. 
Procedure 6 proposes that CEMS data collected during out-of-control 
periods not be used in calculating compliance with emission limits nor 
be counted towards meeting minimum data availability requirements under 
an applicable regulation or permit.
     Criteria for Acceptable QC Procedures. In situations where 
a CEMS experiences excessive audit inaccuracies for two consecutive 
quarters, the proposed procedure requires that you revise your QC 
procedures, or modify or replace your CEMS.
     Criteria for Optional QA Test Frequency. The proposed 
Procedure 6 specifies that, if a CEMS is determined to be in-control 
for eight consecutive quarters that include a minimum of two RATA, you 
may revise your auditing procedures to use CGA or DSA each quarter for 
eight subsequent quarters. Under this scenario, you would only be 
required to perform a RATA that meets the acceptance criteria once 
every two years. If a CEMS fails a RATA, CGA, or DSA, you would need to 
revert to the original auditing schedule until the audit results meet 
in-control criteria to start re-qualifying for the optional QA test 
frequency again.
     Calculations for CEMS Data Accuracy. The proposed 
Procedure 6 specifies RA, CGA accuracy and DSA accuracy calculation 
requirements.

E. What are the reporting and recordkeeping requirements for Procedure 
6?

    The proposed Procedure 6 would require that if you own or operate 
an affected HCl CEMS, you must report for each CEMS the accuracy and CD 
assessment results as a Data Assessment Report (DAR) (an example of a 
DAR format is provided in Procedure 6; section 9.0, Figure 1). At a 
minimum, the DAR must contain source owner and operator information; 
identification and location of monitors in the CEMS; manufacturer and 
model number of each monitor in the CEMS; assessment of CEMS data 
accuracy; and date of assessment. The DAR is required to be submitted 
with the report of emissions required under the applicable regulation 
or permit that requires continuous emission monitoring.

V. Rationale for Selecting the Proposed Requirements of Performance 
Specification 18 and Procedure 6

A. What information did we use to develop PS-18 and Procedure 6?

    To develop proposed PS-18 and Procedure 6, we considered the 
requirements of emission standards promulgated under 40 CFR parts 60, 
61 and 63; state agency requirements for CEMS; manufacturer and vendor 
recommendations; and current operational and design practices in the 
industry. As part of this consideration, the EPA's Office of Air 
Quality Planning and Standards (OAQPS) gathered information from 
instrument and gas vendors, affected facilities, testers and regulatory 
bodies with experience performing continuous measurements of HCl from 
stationary sources.
    Concurrent with the EPA's OAQPS' information gathering efforts, the 
EPA's Office of Research and Development (ORD) conducted research to 
establish additional data to support the new performance specification 
and QA test procedures. As part of the EPA's ORD's research efforts, 
they evaluated commercial HCl CEMS under controlled and representative 
emission environments, the suitability of candidate RMs and the status 
and quality of available gas standards. The ORD focused their testing 
research on interference tests, LOD tests, 7-day drift, linearity, 
RATAs and DS.

B. How did we select the requirements for PS-18 and Procedure 6?

    Generally, the basic requirements proposed under PS-18 and 
Procedure 6 for calibration error, calibration drift, RATA, and 
cylinder gas audit agreement are consistent with other CEMS performance 
specifications. The proposed LOD requirements are based on an adequate 
safety margin so that equipment can measure quantitatively at the 
compliance limit. The proposed DS requirements are consistent with 
other RM recovery requirements (e.g., EPA Method 320, EPA Method 18). 
The above-span calibration and linearity requirements proposed are 
based on the PS-12 precedent used for mercury CEMS.
    During the development of the proposed PS-18 and Procedure 6, we 
evaluated all options and attempted to develop the most appropriate 
performance specifications and procedures based on available 
information, testing and feedback from vendors and industry regarding 
the use of HCl CEMS. Although we believe this proposal includes the 
most appropriate HCl CEMS performance specifications and procedures 
(for use as an alternative to PS-15 for HCl CEMS), we are soliciting 
comment on several issues provided in paragraph V.C of this preamble.

C. Solicitation for Comment

1. Performance Specification 18 Topics
a. Integrated Path (IP-CEMS) Line Strength Factor
    Calibration error procedures proposed for IP-CEMS in PS-18 require 
correcting for calibration cell path length, temperature, pressure, 
line strength factor (LSM) and, if necessary, the native source gas HCl 
concentration when you calculate the stack equivalent concentration of 
the HCl gas measured in your calibration cell. The proposed 
specification allows the use of the line LSM provided by the instrument 
manufacturer or an instrument-specific LSM experimentally determined 
using a heated gas cell at effective gas concentrations equivalent to 
between 50 and 150 percent of the emission limit. We are soliciting 
comment on approaches used by IP instrument vendors to determine LSM 
and data showing the effect of LSM on the accuracy of the stack 
equivalent concentration calculation.
b. Optical Measurement Path Length Determination
    An IP-CEMS measures the gas concentration along an open optical 
path across the stack or duct cross section. Specifically, for IP-CEMS, 
measurement path is the distance of the optical path that passes 
through the source gas in the stack or duct correcting for ports, 
standoffs, and extensions or CEM-specific optical path length 
alterations. The optical measurement path length must be measured and 
not based on engineering diagrams. We are requesting information on 
procedures currently available to measure the optical path length for 
IP monitors that will result in an accuracy of at least  1 
percent. (See PS-1 of Appendix B to Part 60 (Specifications and Test 
Procedures for Continuous Opacity Monitoring Systems in Stationary 
Sources); section 8.1.)

[[Page 27696]]

c. Alternative CEMS Probe Placement Locations
    Section 8.3 of the proposed PS-18 specifies HCl measurement 
location requirements downstream of the control device, point of 
pollution generation or other point at which a change of pollutant 
concentration may occur and upstream of the exhaust. We are seeking 
comment and supporting data on alternative probe placement locations 
such as in the breeching of the stack (i.e., in the exhaust duct or 
pipe that leads from the stack) that pass the RATA requirements.
2. Appendix F Procedure 6 Topics
a. Effect of Temperature and Pressure on HCl Concentration 
Determination During DS Measurements
    We provided options in Appendix F Procedure 6 for initial and 
ongoing quality control using DS for IP-CEMS. The procedure to perform 
DS is described in Appendix A of PS-18. For IP-CEMS, dynamic spiking is 
a standard addition procedure where you spike a known concentration of 
HCl gas into a calibration cell. You are required to assess the 
accurate recovery of HCl introduced into the measurement system in the 
presence of potential interference from the flue gas sample matrix. The 
measurement involves recording the combined optical signal from HCl in 
the calibration cell at ambient temperature and HCl in the stack at 
elevated temperature. The combination of HCl absorbance at two 
different temperatures would create hybrid spectra features of both 
temperatures. Based on our evaluation, we understand there can be as 
much as a 10 percent difference line shape/area used for IP 
measurements between instrument operating temperature near 20[deg]C and 
typical stack temperatures up to 250[deg]C. We are requesting comment 
on procedures that can be used to determine the concentration when IP 
calibration cells contain HCl at ambient temperature (approximately 
20[deg]C) or the need to heat the calibration cell to a specific 
temperature during DS measurements that include absorbance for both 
stack gas (HCl) at elevated temperature and ambient temperature 
calibration cell HCl.
b. Use of Dynamic Spiking
    The proposed PS-18 and Procedure 6 require that you audit the 
accuracy of each HCl CEMS at least once each calendar quarter (except 
the quarter the RATA is conducted) by a DSA, a CGA or other acceptable 
alternative. Appendix A to the proposed PS-18 describes the procedure 
and performance requirements for DS as a quality check for HCl CEMS. We 
are proposing this option as one of three alternatives to a RATA in 
three of the four quarterly QA checks required in Procedure 6. We are 
soliciting comment on our proposal and data on the use of periodic DS 
as an alternative to the use of a CGA.
c. Alternative QA for Low Level RM RATA Measurements
    We are proposing a mandatory RATA with the appropriate RM during 
initial demonstration and periodically thereafter. We are also 
soliciting comment and data on alternative or additional QA that should 
be performed when the stack HCl concentration is below the RM 
quantitation limit.
d. Long-Term Quality Control Under Procedure 6
    The proposed Appendix F to part 60 (Quality Assurance Procedure 6) 
requires a RATA at least once every four calendar quarters, except in 
the case where the affected facility is off-line (does not operate in 
the fourth calendar quarter since the quarter of the previous RATA). 
Section 5.5 of the procedure specifies that if the CEMS is in-control 
for eight consecutive quarters that include a minimum of two RATA, you 
may revise your auditing procedures to use CGA or DSA each quarter for 
eight subsequent quarters, but you must perform at least one RATA and 
demonstrate that the source meets the acceptance criteria every 2 
years. We are requesting comments and data on alternative grace periods 
allowed between required RATAs when your audits demonstrate that the 
source has been in-control long-term under Procedure 6.
e. Method 205 to Generate Cylinder Gas Audit Concentrations for 
Quarterly Audits
    Section 7.3 (Reagents and Standards) of the proposed PS-18 allows 
the use of diluted high concentration HCl standards to achieve the HCl 
gas concentrations required in PS-18 as long as you follow Method 205 
or other procedures approved by the Administrator. We are soliciting 
comment and data comparing the uncertainty of gases generated by 
dilution using Method 205 to the tolerance allowed for cylinder gas 
audits in section 5.2.2.3 of Procedure 6 proposed for 40 CFR part 60, 
Appendix F.
f. Direct Instrument Cell Calibration Checks
    As noted previously, for extractive CEMS, DS involves adding a 
known concentration of HCl gas at a known flow rate into the probe 
sample gas stream to assess the ability of the measurement system to 
recover and accurately measure HCl in the presence of potential 
interference from the flue gas matrix. We are considering an 
alternative that includes instrument calibration checks for extractive 
CEMS and request comment and supporting data on two topics related to 
calibration check procedures: (1) What is the feasibility of achieving 
DS accuracy to 95 percent of the theoretical spike at the span 
concentration? and (2) If calibration checks are performed at the 
instrument for extractive CEMS, what is the accuracy of dynamic spike 
recovery?
g. Using DS and Associated Acceptance Criteria as an Alternative to 
Daily Calibration Check for Quality Assurance Procedure 6
    Calibration drift is a quantitative assessment of whether your HCl 
CEMS measurements are in control. Checking calibration also allows the 
facility to reset the calibration and improve the consistency and 
quality of HCl CEMS data. We are considering using dynamic spiking as 
an alternative to direct cylinder gas assessment of calibration drift 
as a measure of QC for HCl CEMS. We are taking comment and data on the 
quantitative comparison of dynamic spike recovery results compared to 
CD results to determine if there are comparable criteria for DS to 
qualify as an alternative for CD tests.
h. Moisture Measurements To Correct HCl Results
    Section 6.8 (Moisture Measurement System) of the proposed PS-18 
stipulates that, if correction of the measured HCl emissions for 
moisture is required, either Method 4 in Appendix A-3 of part 60 or 
other moisture measurement methods approved by the Administrator will 
be needed to measure stack gas moisture content. We are requesting 
comment/data on conditions or situations where continuous moisture 
measurements should be required to correct HCl results to the units of 
the standard, and where periodic Method 4 tests or equivalent is good 
enough on a periodic basis to define moisture for the entire duration 
between Method 4 tests.
i. Other Initial or On-Going Procedures for IP-CEMS
    We are soliciting comment/data on other initial or on-going 
procedures for

[[Page 27697]]

IP-CEMS not included in the proposal that are commonly performed and 
necessary to ensure data are of known and acceptable quality to 
demonstrate compliance.

VI. 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 action provides performance 
criteria and QA test procedures for assessing the acceptability of HCl 
CEMS performance and data quality. These criteria and QA test 
procedures do not add information collection requirements beyond those 
currently required under the applicable regulation.

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 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 rule on small 
entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. This 
proposed rule will not impose any requirements on small entities. 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 public 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 UMRA.
    This action is also not subject to the requirements of section 203 
of the UMRA because it contains no regulatory requirements that might 
significantly or uniquely affect small governments. This rule will not 
apply to such governments and will not impose any obligations upon 
them.

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. 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 the EPA and state and local 
governments, the 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 
proposes performance specifications that can be used as an additional 
option to PS-15 for HCl continuous emissions monitoring. Thus, 
Executive Order 13175 does not apply to this action. The EPA solicits 
additional comment on this proposed action from tribal officials.

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

    The EPA interprets Executive Order 13045 (62 FR 19885, April 23, 
1997) 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 
action is not subject to Executive Order 13045 because it does not 
establish an environmental standard intended to mitigate health or 
safety risks.

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

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

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113, 12(d) (15 U.S.C. 272 note) 
directs the EPA to use voluntary consensus standards (VCS) 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 VCS bodies. The NTTAA directs the EPA to provide Congress, 
through OMB, explanations when the agency decides not to use available 
and applicable VCS. This proposed rule does not involve technical 
standards. Therefore, the EPA is not considering 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 12898 (59 FR 7629, February 16, 1994) establishes 
federal executive policy on environmental justice. Its main provision 
directs federal agencies, to the greatest extent practicable and 
permitted by law, to make environmental justice part of their mission 
by identifying and addressing, as appropriate, disproportionately high 
and adverse human health or environmental effects of their programs, 
policies, and activities on minority populations and low-income 
populations in the United States.
    The 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

[[Page 27698]]

because it does not affect the level of protection provided to human 
health or the environment. This proposed rule will help to ensure that 
emission control devices are operated properly and maintained as 
needed, thereby helping to ensure compliance with emission standards, 
which would benefit all affected populations.

Performance Specification 18--Specifications and Test Procedures for 
Gaseous HCl Continuous Emission Monitoring Systems at Stationary 
Sources

List of Subjects in 40 CFR Part 60

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Continuous emission monitoring systems, Hydrogen 
chloride, Performance specifications, Test methods and procedures.

    Dated: April 30, 2014.
Gina McCarthy,
Administrator.

    For the reasons stated in the preamble, the Environmental 
Protection Agency proposes to amend title 40, chapter 1 of the Code of 
Federal Regulations as follows:

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

    Authority: 42 U.S.C., 7401-7671q.

0
2. Appendix B is amended by adding Performance Specification 18 and 
Appendix A to Performance Specification 18 to read as follows:

Appendix B to Part 60--Performance Specifications

* * * * *

PERFORMANCE SPECIFICATION 18--PERFORMANCE SPECIFICATIONS AND TEST 
PROCEDURES FOR GASEOUS HYDROGEN CHLORIDE (HCl) CONTINUOUS EMISSION 
MONITORING SYSTEMS AT STATIONARY SOURCES

    1.0 Scope and Application.
    1.1 Analyte. This performance specification (PS) is applicable 
for measuring gaseous concentrations of hydrogen chloride (HCl), 
CAS: 7647-01-0, on a continuous basis in the units of the applicable 
standard or in units that can be converted to units of the 
applicable standard(s).
    1.2 Applicability.
    1.2.1 This specification is used to evaluate the acceptability 
of HCl continuous emission monitoring systems (CEMS) at the time of 
installation or soon after and when regulations require reevaluation 
of HCl CEMS performance. The specification includes requirements for 
initial acceptance including instrument accuracy and stability 
assessments.
    1.2.2 The Administrator may require the operator under section 
114 of the Clean Air Act (CAA), to conduct CEMS performance 
evaluations at other times besides the initial test to evaluate the 
CEMS performance. See 40 CFR part 60, Sec.  60.13(c) and Sec.  
63.8(e)(1).
    1.2.3 A source that demonstrates their CEMS meets the criteria 
of this PS may use the system to continuously monitor gaseous HCl. 
If your HCl CEMS is capable of reporting the HCl concentration in 
the units of the existing standard, no additional CEMS components 
are necessary. If your HCl CEMS does not report concentrations in 
the units of the existing standard, then other CEMS components 
(e.g., oxygen (O2), temperature, stack gas flow, moisture 
and pressure) are necessary to convert the units reported by your 
HCl CEMS to the units of the standard.
    1.2.4 These specification test results are intended to be valid 
for the life of the system. As a result, the HCl measurement system 
must be tested and operated in a configuration consistent with the 
configuration that will be used for ongoing continuous emissions 
monitoring.
    1.2.5 Substantive changes to the system configuration require 
retesting according to this PS. Examples of such conditions include, 
but are not limited to: major changes in dilution ratio (for 
dilution based systems); changes in catalyst materials, if used; 
changes in sample conditioning, if used, such as filtering device 
design or materials; changes in probe design or configuration; light 
source or detector substitution; and changes in materials of 
construction.
    1.2.6 This specification is not designed to evaluate the ongoing 
CEMS performance nor does it identify specific calibration 
techniques and auxiliary procedures to assess CEMS performance over 
an extended period of time. The source owner or operator is 
responsible to calibrate, maintain, and operate the CEMS properly.
    2.0 Summary of Performance Specification.
    2.1 This specification covers the procedures that each HCl CEMS 
must meet during the performance evaluation test. Installation and 
measurement location specifications, data reduction procedures and 
performance criteria are included.
    2.2 The technology used to measure gaseous HCl must provide a 
distinct response and address any appropriate interference 
correction(s). It must accurately measure gaseous HCl in a 
representative sample (path or point sampling) of stack effluent.
    2.3 The relative accuracy (RA) must be established against a 
reference method (RM) (e.g., Method 26A, Method 320, ASTM 
International (ASTM) D6348-12, including mandatory annexes, or 
Method 321, as appropriate for the source concentration and 
category).
    2.4 Dynamic spiking (DS) into the CEMS using a National 
Institute of Standards and Technology (NIST) traceable standard may 
be required to demonstrate performance at sources with emissions 
near the detection level of the CEMS and for ongoing quality 
assurance tests.
    3.0 Definitions.
    3.1 Calibration Cell means a gas containment cell used with 
cross stack or integrated path (IP) monitors to perform precision 
and calibration checks. The cell may be a removable sealed cell or 
an evacuated and/or purged cell capable of exchanging calibration 
and zero gases. When charged, it contains a known concentration of 
HCl calibration gas. The calibration cell is filled with zero gas or 
removed from the optical path during stack gas measurement.
    3.2 Calibration Drift (CD) means the absolute value of the 
difference between the CEMS output response and an upscale reference 
or a zero-level reference, expressed as a percentage of the span 
value, when the CEMS is challenged after a stated period of 
operation during which no unscheduled maintenance or repair took 
place. A separate CD determination must be performed for pollutant 
and diluent analyzers.
    3.3 Calibration Error (CE) means the mean difference between the 
concentration measured by the CEMS and the known concentration from 
a calibration standard, divided by the span, when the entire CEMS, 
including the sampling interface, is challenged.
    3.4 Calibration Range Above Span (CRAS) means the upper limit of 
the measurement range. The calibration range must accommodate the DS 
procedure if that option is selected. The CRAS should be a 
conservatively high estimate of the range of HCl measurements 
expected from the source category. The CRAS value defines the 
calibration and quality assurance at the upper limit of HCl 
concentration measurement. The CRAS may require a calibration 
standard above span.
    3.5 Centroidal Area means a central area that is geometrically 
identical to the stack or duct cross section and is no greater than 
ten percent of the stack or duct cross-sectional area.
    3.6 Continuous Emission Monitoring System (CEMS) means the total 
equipment required to measure the pollutant concentration or 
emission rate continuously.
    3.7 Continuous Operation means the time between periodic 
maintenance when an instrument and sampling system operates without 
user intervention, continuously samples flue gas, analyzes the 
sample gas for HCl and related parameters (e.g., gas flow, diluent), 
records measurement data, and saves the results to a computer file. 
User intervention is permitted for initial set-up of sampling 
system, initial calibrations, periodic calibration corrections, 
periodic maintenance and periodic quality assurance audits.
    3.8 Data Recorder means the portion of the CEMS that provides a 
permanent record of analyzer output. The data recorder may record 
other pertinent data such as effluent flow rates, various instrument 
temperatures or abnormal CEMS operation. The data recorder may also 
include automatic data reduction capabilities and CEMS control 
capabilities.
    3.9 Dynamic Spiking (DS) means the procedure where a known 
concentration of HCl gas is injected into the probe sample gas 
stream for extractive CEMS at a known flow rate, or used to fill a 
calibration cell for in situ IP-CEMS, in order to assess the 
accuracy of the measurement system in the presence of potential 
interference from the flue gas sample matrix.
    3.10 Independent Measurement(s) means the series of CEMS data 
values taken during

[[Page 27699]]

sample gas analysis separated by two times the response time (RT) of 
the CEMS.
    3.11 Integrated Path CEMS (IP-CEMS) means a CEMS that measures 
the gas concentration along an optical path in the stack or duct 
cross section.
    3.12 Interference means a compound or material in the sample 
matrix other than HCl whose characteristics may bias the CEMS 
measurement (positively or negatively). The interference may not 
prevent the sample measurement, but could increase the analytical 
uncertainty in the measured HCl concentration through reaction with 
HCl or by changing the electronic signal generated during HCl 
measurement.
    3.13 Interference Test means the test to detect analyzer 
responses to interferences that are not adequately accounted for in 
the calibration procedure and may cause measurement bias.
    3.14 Level of Detection (LOD) means the lowest level of 
pollutant the CEMS can detect with 99 percent confidence in the 
presence of typical source gas matrix interferents.
    3.15 Liquid Evaporative Standard means a reference gas produced 
by vaporizing NIST traceable liquid standards of known HCl 
concentration and quantitatively mixing the resultant vapor with a 
diluent carrier gas.
    3.16 Optical Path means the route light travels from the light 
source to the receiver used to make an optical CEMS sample 
measurement.
    3.17 Path Length means, for extractive optical CEMS, the 
distance in meters of the optical path within a gas measurement 
cell. For IP-CEMS, path length is the distance in meters of the 
optical path that passes through the source gas in the stack or 
duct.
    3.18 Point CEMS means a CEMS that measures the source gas 
concentration, either at a single point at the sampling probe tip or 
over an optical path less than 10 percent of the equivalent diameter 
of the stack or duct cross section.
    3.19 Relative Accuracy (RA) means the absolute mean difference 
between the gas concentration determined by the CEMS and the value 
determined by the RM, plus the 2.5 percent error confidence 
coefficient of a series of tests divided by the average of the RM or 
the applicable emission standard.
    3.20 Response Time (RT) means the time it takes for the 
measurement system, while operating normally at its target sample 
flow rate, dilution ratio, or data collection rate to respond to a 
known step change in gas concentration, either from a low- or zero-
level to a high-level gas concentration or from a high level to a 
low or zero level, and to read within five percent of the stable gas 
response.
    3.21 Sample Interface means the portion of the CEMS used for one 
or more of the following: Sample acquisition, sample transport, 
sample conditioning, optical measurement path, or protection of the 
analyzer from the effects of stack gas.
    3.22 Span Value means the value established by the relevant 
regulatory requirement or is equal to twice the emission limit if 
not otherwise specified.
    3.23 Stratification means the identification of when a 
measurement taken at a single point in a duct or emission stack is 
different from measurements taken at multiple points that traverse 
the duct or stack.
    3.24 Zero gas means a calibration gas or liquid evaporative 
spike with an HCl concentration that is below the LOD of the 
measurement system.
    4.0 Interferences.
    Sample gas interferences will vary depending on the instrument 
or technology used to make the measurement. Interferences must be 
evaluated through the interference test in this performance 
specification. Several compounds including carbon dioxide 
(CO2), carbon monoxide (CO), formaldehyde 
(CH2O), methane (CH4), and water 
(H2O) are potential optical interferences with certain 
types of HCl monitoring technology. Ammonia is a potential chemical 
interference with HCl.
    5.0 Safety.
    The procedures required under this PS may involve hazardous 
materials, operations, and equipment. This PS may not address all of 
the safety issues associated with these procedures. It is the user's 
responsibility to establish appropriate safety and health practices 
and determine the applicable regulatory limitations prior to 
performing these procedures. The CEMS users should consult 
instrument operation manuals, compressed gas safety requirements 
such as Occupational Safety and Health Administration regulations 
and other material safety data sheets for specific precautions to be 
taken.
    6.0 Equipment and Supplies.
    Equipment and supplies for HCl CEMS will vary depending on the 
measurement technology and equipment vendors. This section provides 
a description of the equipment and supplies typically found in one 
or more types of HCl CEMS.
    6.1 Sample Extraction System. The portion of an extractive CEMS 
that collects and transports the sample to the pressure regulation 
and sample conditioning module. The extraction system must deliver a 
representative sample to the measurement instrument. The sample 
extraction system typically consists of a sample probe and a heated 
umbilical line.
    6.2 Sample Conditioning Module. The portion of an extractive 
CEMS that removes particulate matter and moisture from the gas 
stream and provides a sample gas stream to the CEMS analysis module 
or analyzer. You must keep the particle-free gas sample above the 
dew point temperature of its components.
    6.3 HCl Analyzer. The portion of the CEMS that detects, 
quantifies and generates an output proportional to the stack gas HCl 
concentration.
    6.4 Diluent Analyzer. The portion of the CEMS that quantifies 
stack gas concentrations of O2 or CO2. For 
systems with a multi-component analyzer, the same analyzer may 
quantify for all measured gases.
    6.5 System Controller. The portion of the CEMS that provides 
control of the analyzer and any sample extraction system components 
including the probe, pressure sensing and regulation, sample 
conditioning module and the sample interface.
    6.6 Data Recorder. The portion of the CEMS that provides a 
record of analyzer output. The data recorder may record other 
pertinent data such as effluent flow rates, various instrument 
temperatures or abnormal CEMS operation. The data recorder output 
range must include the full range of expected HCl concentration 
values in the gas stream to be sampled including zero and span 
value. Multiple instrument ranges or extended calibration points to 
extend the measurement range may be necessary to measure 
concentrations encountered during normal process operation.
    6.7 Reference Gas System(s). One or more systems may be needed 
to introduce calibration gases into the measurement system. You will 
use a reference gas system to introduce a known concentration of HCl 
gas into the measurement system. For extractive CEMS, the system 
must be able to introduce reference gas flow sufficient to flood the 
sampling probe and prevent entry of gas from the effluent stream. 
For IP-CEMS, the system must be able to introduce a known 
concentration of HCl, at known pressure and temperature, into the 
optical path used to measure HCl gas concentration.
    6.8 Moisture Measurement System. If correction of the measured 
HCl emissions for moisture is required, either Method 4 in Appendix 
A-3 of this part or other moisture measurement methods approved by 
the Administrator will be needed to measure stack gas moisture 
content.
    7.0 Reagents and Standards.
    7.1 Reference cylinder gas(es) or liquid evaporative gas 
standards used to meet the performance specifications must be 
traceable to NIST.
    7.2 Cylinder gas and/or liquid evaporative standards must be 
used within their certification period.
    7.3 High concentration HCl standards may be diluted for use in 
this specification. You must document the quantitative introduction 
of HCl standards into the system using Method 205 or other procedure 
approved by the Administrator.
    8.0 CEMS Measurement Location Specifications and Pretest 
Preparation.
    8.1 Prior to the start of your initial PS tests, you must ensure 
that the HCl CEMS is installed according to the manufacturer's 
specifications and the requirements in this section. You may use 
either point or IP sampling technology.
    8.2 Installation. Install the CEMS at an accessible location 
where the pollutant concentration or emission rate measurements are 
directly representative of the HCl emissions or can be corrected so 
as to be representative of the emissions from the affected facility. 
For CEMS sampling at a single point, a location that has been shown 
to be free of HCl (or sulfur dioxide (SO2)) 
stratification is recommended. If you fail the RA requirements in 
this specification due to the measurement location and a 
satisfactory correction technique cannot be established, the 
Administrator may require the CEMS to be relocated.
    8.3 Measurement Location. The measurement location should be (1) 
at least two equivalent diameters downstream of the nearest control 
device, point of pollution generation or other point at which a 
change of pollutant concentration may occur; and (2)

[[Page 27700]]

at least half an equivalent diameter upstream from the effluent 
exhaust. The equivalent duct diameter is calculated according to 
Method 1 in Appendix A-1 to this part.
    8.3.1 Single point sample gas extraction should be (1) no less 
than 1.0 meter (3.3 ft.) from the stack or duct wall or (2) within 
the centroidal velocity traverse area of the stack or duct cross 
section.
    8.3.2 Path-integrated measurements must (1) be conducted totally 
within the inner area bounded by a line 1.0 meter (3.3 ft.) from the 
stack or duct wall, or (2) have at least 70 percent of the path 
within the inner 50 percent of the stack or duct cross-sectional 
area, or (3) be located over any part of the centroidal area.
    8.4 CEMS and Data Recorder Scale Check. After CEMS installation, 
we recommend you check the CE as described in section 11.7 to verify 
that the instrument is functioning properly. Record and document the 
measurement range of the HCl CEMS. The CEMS operating range (zero 
through CRAS) and the range of the data collection device must 
encompass the applicable emission limit and all expected HCl 
concentrations. The CEMS and data collection device output range 
must include zero and the CRAS value.
    9.0 Quality Control. [Reserved]
    10.0 Calibration and Standardization. [Reserved]
    11.0 Performance Specification Test Procedure.
    After completing the CEMS installation, setup and calibration, 
you must complete the performance specification test procedures in 
this section. You must perform the following procedures and meet the 
performance requirements for the initial demonstration of your HCl 
CEMS:
    a. Interference Test;
    b. Beam Intensity Test (IP-CEMS only);
    c. Stack Temperature Verification (IP-CEMS only);
    d. Stack Pressure Verification (IP-CEMS only);
    e. Level of Detection (LOD) Determination;
    f. Response Time (RT) Test;
    g. Calibration Error (CE) Test;
    h. Calibration Drift (CD) Test; and
    i. Relative Accuracy (RA) Test:
     Comparison with RM
     Stratification Test
     Optional Dynamic Spiking (DS) Test.
    11.1 Interference Test
    11.1.1 You must conduct the interference test of your 
measurement system prior to its initial use in the field to verify 
that the candidate system measures HCl accurately in the presence of 
common interferences in emission matrices.
    11.1.2 Your interference test may be conducted in either a 
controlled environment or on-site during initial setup and 
qualification of your CEMS.
    11.1.3 If you have multiple measurement systems with components 
of the same make and model numbers, you need only perform this 
interference check on one system and you may also rely on an 
interference test conducted by the manufacturer on a system having 
components of the same make and model(s) of the system that you use.
    11.1.4 Perform the interference check with an HCl concentration 
between 10 and 40 percent of the span value anticipated for your 
source CEMS application. Alternatively, successfully conducting the 
interference test at the relevant regulatory standard may be used to 
demonstrate performance.
    11.1.5 Introduce the interference test gases listed in Table 1 
in section 17.0 into the measurement system separately or in any 
combination.
    11.1.5.1 For extractive CEMS, the interference test gases must 
be introduced into the sampling system at the probe such that the 
interference gas mixtures pass through all filters, scrubbers, 
conditioners, and other components as would be configured at a 
typical field site.
    11.1.5.2 For IP-CEMS, the interference test gases may be added 
with the HCl in a calibration cell or separately in a temperature-
controlled cell with an effective path length in the optical CEMS 
path representative of the required method detection level. Test gas 
and interference gas is added to the cell at a concentration that is 
equivalent to the effective stack concentration corrected for 
pressure, temperature and the nominal stack sampling path length of 
the CEMS.
    11.1.6 The interference test must be performed by combining an 
HCl gas with each interference test gas (or gas mixture). You must 
measure the baseline HCl response, followed by the response after 
adding the interference test gas(es) at a constant HCl 
concentration. Your baseline HCl measurement must agree within three 
percent of the theoretical HCl concentration. You must perform each 
interference gas injection and evaluation in triplicate, and assess 
the combined interference of all of the gases in Table 1.

(Note: The baseline HCl injection may include interference gases at 
concentrations typical of ambient air (e.g., 21 percent 
O2, 400 parts per million (ppm) CO2, 2 percent 
H2O), but these concentrations must be brought to the 
concentrations listed in Table 1 when their interference effects are 
being evaluated.)

    11.1.7 You must document the quality and quantity of the gas 
volume/rate, temperature, and pressure used to conduct the 
interference test to be able to establish the error of blending the 
HCl and interference gases while maintaining a known HCl 
concentration. A gas blending system or manifold may be used.
    11.1.8 The duration of each interference test should be 
sufficient to ensure the HCl measurement system surfaces are 
conditioned and a stable measurement is obtained.
    11.1.9 Measure the HCl response of the analyzer to these gases 
in ppm. Record the responses and determine the overall interference 
response using Table 2 in section 17.0.
    11.1.10 For each interference gas (or mixture), calculate the 
mean difference ([Delta]MCavg) between the measurement 
system responses with and without the interference test gas(es) 
using Equation 1 in section 12.0. Summarize the results following 
the format contained in Table 2 in section 17.0.
    11.1.11 Calculate the total percent interference (I) for the gas 
runs using Equation 2 in section 12.0. The combined interference 
response for the analyzer that was used for the test must not be 
greater than  3.0 percent of the equivalent HCl 
concentration used for the interference test.
    11.2 Beam Intensity Test for IP-CEMS
    11.2.1 For IP-CEMS, you must establish the beam intensity 
attenuation tolerance of your system and demonstrate that the HCl 
span response is independent of the beam intensity in the absence of 
HCl.
    11.2.2 Insert one or more neutral density filter(s) or otherwise 
attenuate the beam intensity (e.g., 90 percent of the beam 
intensity).
    11.2.3 Perform a high-level calibration check.
    11.2.4 Record and report the attenuated beam intensity, 
calibration gas concentration measured by the CEMS and the percent 
difference between the measured calibration gas concentration at 
full beam intensity and the measured concentration with attenuated 
beam intensity. The percent difference during the attenuated beam 
intensity calibration check for the light source and detector used 
in the IP-CEMS must not be more than  3.0 percent of the 
measured calibration concentration used for the test.
    11.2.5 In the future, you may not operate your IP-CEMS at a beam 
intensity lower than that established during this test. However, you 
may repeat the test to establish a lower beam intensity cut point.
    11.3 Temperature Measurement Verification Procedure for IP-CEMS
    11.3.1 Any measurement instrument or device that is used to 
conduct ongoing verification of temperature measurement must have an 
accuracy that is traceable to NIST.
    11.3.2 You must perform a temperature verification test on-site 
as part of the initial installation and verification procedures.
    11.3.3 Comparison to Calibrated Temperature Measurement Device.
    11.3.3.1 Place the sensor of a calibrated temperature 
measurement device adjacent to the sensor used to measure stack 
temperature for your HCl CEMS. The calibrated temperature 
measurement device must satisfy the accuracy requirements specified 
in Table 3 of this PS. The calibrated temperature measurement device 
must also have a range equal to or greater than the range of your 
HCl CEMS temperature monitor.
    11.3.3.2 Allow sufficient time for the response of the 
calibrated temperature measurement device to reach equilibrium. With 
the process or control device operating under normal conditions 
concurrently, record the temperatures measured by your HCl CEMS 
system (Mt) and the calibrated measurement device 
(Vt). You must meet the accuracy requirements described 
in section 13.5.4 of this PS.
    11.3.3.3 If your HCl CEMS temperature monitor does not satisfy 
the accuracy requirement of this PS, check all system components and 
take any corrective action that is necessary to achieve the required 
minimum accuracy. Repeat this validation check procedure until the 
accuracy requirement of this specification is satisfied.
    11.4 Pressure Measurement Verification Test for IP-CEMS

[[Page 27701]]

    11.4.1 For stack pressure verification, you should select a 
gauge or monitor that conforms to the design requirements of ASME 
B40.100-2010, ``Pressure Gauges and Gauge Attachments'' 
(incorporated by reference--see Sec.  60.17).
    11.4.2 As an alternative for a calibrated pressure measurement 
device with NIST traceable accuracy, you may use a mercury-in-glass 
or water-in-glass U-tube manometer to validate your pressure 
measurement equipment.
    11.4.3 Allow sufficient time for the response of the calibrated 
pressure measurement device to reach equilibrium. With the process 
or control device operating under normal conditions, concurrently 
record the pressures measured by your HCl CEMS system 
(MP) and the calibrated measurement device 
(Vp). You must meet the accuracy requirements described 
in section 13.5.5 of this PS.
    11.4.4 If your HCl CEMS pressure monitor does not satisfy the 
accuracy requirement of this PS, check all system components and 
take any corrective action that is necessary to achieve the required 
minimum accuracy. Repeat this validation check procedure until the 
accuracy requirement of this specification is satisfied.
    11.5 Level of Detection (LOD) Determination
    11.5.1 You must determine the minimum amount of HCl that can be 
detected above the background in a representative gas matrix.
    11.5.2 You may perform the LOD determination as part of the 
interference test in section 11.1, in either a controlled 
environment or on-site during initial setup and qualification of 
your CEMS.
    11.5.2.1 For extractive CEMS, spike the HCl and interferents 
into the CEMS at the probe prior to all filters and sample 
conditioning elements.
    11.5.2.2 For IP-CEMS, spike the mixture described in section 
11.1.4 into the system calibration cell.
    11.5.3 The challenge standard mixture used to determine LOD must 
include HCl at a concentration no greater than three times the 
estimated LOD and must include the interferences listed in Table 1 
of this PS.
    11.5.4 Collect seven consecutive measurements separated by twice 
the response time.
    11.5.5 Calculate the standard deviation of the measured values 
and define the LOD as three times the standard deviation of these 
measurements.
    11.5.5.1 The LOD for extractive units must be determined and 
reported in ppmv.
    11.5.5.2 The LOD for IP units must be determined and reported on 
a ppm-meter basis and the site- or installation-specific LOD must be 
calculated based on the actual measurement path length and gas 
density of the specific site installation in ppmv.
    11.5.6 If you choose to perform the LOD determination test in a 
controlled environment, you must verify the LOD during the initial 
field certification test using the DS test procedure in Appendix A 
of this PS.
    11.5.6.1 You must make three independent DS measurements at no 
more than five times the LOD for the detection level verification.
    11.5.6.2 If your system limitation verification does not 
demonstrate the ability to distinguish the spike concentration from 
the background, you must increase the spike concentration 
incrementally until you establish a field verified detection level 
where the HCl measurement is a minimum of three times the noise for 
zero HCl concentration. The field verified detection level replaces 
the controlled environment LOD and becomes the site- or 
installation-specific LOD.
    11.6 Response Time Determination
    11.6.1 If your HCl CEMS extracts gas from stack emissions you 
must determine the average upscale and downscale RTs from three 
repetitions of each test. You will report the greater of the average 
upscale or average downscale RTs as the RT for the system.
    11.6.2 Start the upscale RT determination by injecting zero gas 
into the measurement system at the extractive probe tip or IP 
calibration cell inlet. You may use humidified zero gas.
    11.6.3 When the system output has stabilized (no change greater 
than 1 percent of full scale for 30 sec), record the response in 
ppmv and introduce an upscale reference gas.
    11.6.4 Take repetitive measurements until you obtain a stable 
value at 95 percent or greater than the expected calibration gas 
response. You may use humidified calibration gas.
    11.6.5 Record the time (upscale RT) required to reach 95 percent 
of the final stable value.
    11.6.6 Next, reintroduce the zero gas and record the time 
required to reach five percent of the zero gas reading. This time is 
the downscale RT.

(Note: For CEMS that perform a series of operations (purge, blow 
back, sample integration, analyze, etc.), you must start adding 
calibration gases immediately after these procedures are complete.)

    11.6.7 Repeat the entire procedure three times and determine the 
mean upscale and downscale RTs. The slower or longer of the two 
means is the system RT.
    11.7 Calibration Error (CE) Test. The percent CE is the mean 
difference between the HCl calibration gas value and the CEMS 
response at each calibration point expressed as a percentage of the 
span. The CE must be less than five percent.
    11.7.1 Extractive CEMS CE check.
    11.7.1.1 Sequentially introduce calibration gas to the CEMS 
probe, before the sample conditioning and filtration system.
    11.7.1.2 Measure three upscale HCl gas concentrations in the 
ranges shown in Table 4 of this PS.
    11.7.1.3 Introduce the gases into the sampling probe with 
sufficient flow rate to replace the entire source gas sample.
    11.7.1.4 Continue to add the standard gas until the response is 
stable as evidenced when the difference between two consecutive 
measurements is less than the LOD or within five percent of each 
other.
    11.7.1.5 Make triplicate measurements for each gas standard. 
Introduce different calibration concentrations in any order but do 
not introduce the same gas concentration twice in succession. 
Conduct independent measurements three times for each concentration, 
for a total of nine measurements.
    11.7.1.6 At each reference gas concentration, determine the 
average of the three CEMS responses
[GRAPHIC] [TIFF OMITTED] TP14MY14.038

Calculate the CE using Equation 3 in section 12.0.
    11.7.1.7 If you desire to determine the system RT during this 
test, you may inject zero gas immediately followed by the high-level 
standard.
    11.7.1.8 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 CE checks, and you may make only 
the adjustments necessary to maintain the proper ratio.
    11.7.2 IP-CEMS CE check
    11.7.2.1 Conduct a 3-point system CE test by sequential addition 
of known concentrations of HCl standard into a calibration cell of 
known volume, temperature, pressure and path length.

(Note: The optical path used for IP-CEMS calibration error checks 
must include the native measurement path. You must also collect 
native stack concentration before and after each HCl standard 
measurement. Bracketing HCl standard measurements with native stack 
measurements may be used in the calculations to correct the upscale 
measurements for stack gas HCl concentration changes.)

    11.7.2.2 Introduce HCl standards into your calibration cell in a 
range of concentrations that produce responses equivalent to the 
source concentrations shown in Table 4 for your path length.
    11.7.2.3 Introduce the low-, mid-, and high-level calibration 
standards in any order. Make three independent measurements of each 
concentration. Introduce different calibration concentrations in any 
order but do not introduce the same gas concentration twice in 
succession.
    11.7.2.4 You must calculate the equivalent concentration 
(Ci,eff) of the HCl calibration gas equivalent to the 
stack concentration by correcting for calibration cell temperature, 
pressure, path length, line

[[Page 27702]]

strength factor (LSM) and, if necessary, the native source gas HCl 
concentration using equations 4, 5 and 6 in section 12.0.
    11.7.2.5 You may use the LSM provided by your instrument 
manufacturer or determine an instrument-specific LSM as a function 
of temperature using a heated gas cell and effective gas 
concentrations (Ci,eff) between 50 and 150 percent of the 
emission limit.
    11.7.2.6 At each gas concentration, determine the average of the 
three independent CEMS measurement responses corrected for stack 
concentration, and the average response during zero gas injections 
(background or native stack gas measurement). Calculate the CE using 
Equation 6 in section 12.0.
    11.7.3 You may use Figure 1 to record and report your CE test 
results.
    11.7.4 If the CE specification is not met for all three standard 
concentrations, take corrective action and repeat the test until an 
acceptable 3-point CE test is achieved.
    11.8 Seven-Day Calibration Drift (CD) Test
    11.8.1 The CD Test Period. Prior to the start of the RA tests, 
you must perform a CD test. The purpose of the CD measurement is to 
verify the ability of the CEMS to maintain calibration for each of 
seven, 24-hour periods.
    11.8.2 The CD tests must be performed using the zero and either 
mid-level or high-level calibration standards as defined in Table 4.
    11.8.3 Conduct the CD test during normal facility operations 
following the procedures in section 11.7 of this PS.
    11.8.4 If periodic automatic or manual adjustments are made to 
the CEMS zero and upscale response factor settings, conduct the CD 
test immediately before these adjustments.

(Note: Automatic signal or mathematical processing of all 
measurement data to determine emission results may be performed 
throughout the entire CD process.)

    11.8.5 Determine the magnitude of the CD at 24-hour intervals, 
for seven consecutive unit operating days. The seven consecutive 
unit operating days need not be seven consecutive calendar days. You 
may use Figure 2 to record and report the results of your CD test.
    11.8.6 Record the average CEMS response for zero gas and mid- or 
high-level calibration gas.
    11.8.6.1 For extractive CEMS, calculate the CD using Equation 3 
in section 12. Report the absolute value of the differences as a 
percentage of the span value.
    11.8.6.2 For IP-CEMS, you may exclude the in stack measurement 
path when determining zero gas concentration. Calculate the CD using 
equations in section 12.4.
    11.8.7 You must record the average CEMS response for each 
reference gas and calculate the mid- or high-level CD using Equation 
6 in section 12.0. Calculate the zero drift value using Equation 7.
    11.8.8 The zero-level and high-level drift for each day must be 
less than five percent of the span value. You must pass each day's 
drift checks for seven days to meet this requirement. Each zero- and 
high-level drift check must be recorded and reported for the seven-
day drift check tests.
    11.9 Relative Accuracy (RA) Test
    11.9.1 Unless otherwise specified in an applicable subpart of 
the regulations, use Method 26A in 40 CFR part 60 Appendix A-8, 
Method 320 and Method 321, both found in 40 CFR part 63 Appendix A, 
or ASTM D6348-12 including mandatory annexes, as the acceptable 
reference methods for HCl measurement. Other RMs for moisture, 
O2, etc., may be necessary. Conduct the RM tests in such 
a way that they will yield results representative of the emissions 
from the source and can be compared to the CEMS data.
    11.9.2 Conduct the diluent (if applicable), moisture (if 
needed), and pollutant measurements simultaneously. However, diluent 
and moisture measurements that are taken within an hour of the 
pollutant measurements may be used to calculate dry pollutant 
concentration and emission rates.
    11.9.3 Stratification Test. A stratification test must be 
conducted during normal facility operating conditions. The purpose 
of this test is to verify that excess stratification of the target 
pollutant does not render the sampling point of the CEMS non-
representative. You must traverse as required in this section while 
taking reference method samples used for the RA testing.
    11.9.3.1 Perform a stratification test at each test site to 
determine the appropriate number of sample traverse points. If 
testing for multiple pollutants or diluents at the same site, a 
stratification test using only one pollutant or diluent satisfies 
this requirement. A stratification test is not required for small 
stacks that are less than four inches in diameter. To test for 
stratification, use a probe of appropriate length to measure the HCl 
concentration or an alternative analyte, as described in this 
section, at 12 traverse points located according to Table 1-1 or 
Table 1-2 of Method 1 in Appendix A-1 to 40 CFR part 60, as 
appropriate.
    11.9.3.2 You may substitute a stratification test for 
SO2 for the HCl stratification test if the HCl 
concentration is less than ten times the LOD of your HCl CEMS. If 
you select this option, you must follow the test procedures in 
Method 6C of Appendix A-4 to 40 CFR part 60.
    11.9.3.3 You may substitute a stratification test for 
CO2, CO or nitrogen oxides (NOX) if you 
anticipate the concentration of both SO2 and HCl are less 
than ten times the associated LOD for the CEMS instrument.
    11.9.3.4 Calculate the mean measured concentration for all 
sampling points (MNavg).
    11.9.3.5 Calculate the percent stratification (St) of 
each traverse point using Equation 8 in section 12.0.
    11.9.3.5.1 If the concentration at any 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 perform a single point RA test.
    11.9.3.5.2 If the 5.0 percent or 0.5 ppm criterion is not met, 
but the concentration at any traverse point differs from the mean 
concentration for all traverse points by no more than: (a) 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 RA samples from three points. Space the 
three points at 16.7, 50.0, and 83.3 percent of the measurement 
traverse line.
    11.9.3.5.3 If the traverse point differs from the mean 
concentration by more than 10 percent, the gas stream is considered 
stratified and you must conduct a full traversing RA test following 
tables 1-1 and 1-2 of Method 1 in Appendix A-1 to 40 CFR part 60.
    11.9.3.6 Conduct all necessary RM tests within 3 cm (1.2 in.) of 
the traverse points, but no closer than 3 cm (1.2 in.) to the stack 
or duct wall.
    11.9.3.7 In order to correlate the CEMS and RM data properly, 
record the beginning and end of each RM run (including the exact 
time of day) with the permanent record of CEMS output.
    11.9.4 Conduct the RA test using an RM.
    11.9.4.1 You must conduct RA tests at the affected facility 
during process operating conditions representing average production 
and full control operation at the source, or as specified in an 
applicable subpart.
    11.9.4.2 Conduct a minimum of nine sets of all necessary RM test 
runs.
    11.9.4.3 If HCl CEMS measurements are less than or equal to 20 
percent of the applicable standard, you must perform a DS 
verification test during CEMS installation and performance tests 
following the procedures in Appendix A of this PS.
    11.9.4.4 When Method 26A is used as the RM, you must conduct the 
RM test runs with paired or duplicate sampling systems and use the 
average of the HCl concentrations measured by the two trains. You 
must sample sufficient gas to reach three times your method 
detection limit for Method 26A in 40 CFR part 60, Appendix A-8, or 
for a minimum of one hour, whichever is less.
    11.9.4.5 Identify outliers in the paired Method 26A data by 
calculating the relative difference (RD) for the paired RM tests. 
Data that do not meet the RD criteria may not be used in the 
calculation of RA. The primary reason for performing paired RM 
sampling is to ensure the quality of the RM data. Determine the RD 
for paired data points using Equation 9 in section 12.0.
    11.9.4.6 The minimum performance criteria for RM paired HCl data 
is an RD for any data pair of <=10 percent when the mean HCl 
concentration is greater than 50 percent of the applicable emission 
limit expressed as an equivalent concentration. If the mean HCl 
concentration is less than or equal to 50 percent of the applicable 
emission limit expressed as an equivalent concentration, the RD must 
be <=20 percent. Pairs of RM data exceeding these RD criteria must 
be eliminated from the data set used to develop the HCl CEMS RA 
assessment.
(Note: More than nine sets of RM tests may be performed. If this 
option is chosen, a maximum of three sets of the test results may be 
rejected when the HCl concentration is greater than 50 percent of 
the applicable standard; a maximum of six sets of test

[[Page 27703]]

results may be rejected when the HCl concentration is less than 50 
percent of the applicable standard so long as the total number of 
test results used to determine the RA is greater than or equal to 
nine. However, all data must be reported, including the rejected 
data.)
    11.9.5 When Method 320 and Method 321, both found in 40 CFR part 
63 Appendix A, or ASTM D6348-12, are used, you must collect gas 
samples that are at stack conditions (hot and wet) and you must 
traverse as required in section 11.9.3.
    11.9.6 Analyze the results from the RM test runs using equations 
in section 12.7 (equations 10-15). Calculate and report the RA 
between the HCl CEMS results and the RM.
    11.9.7 As an option, in addition to performing a RATA with a 
reference method, you may perform a DS test verification during CEMS 
installation and performance tests following the procedures in 
Appendix A of this PS. If the HCl CEMS passes the DS test 
verification, you may use DS as an alternative to selected quarterly 
RATA tests as specified in 40 CFR part 60 Appendix F requirements 
for ongoing quality assessment of the HCl CEMS.
    11.10 Reporting
    11.10.1 For systems that use a gas blender and/or liquid 
evaporative calibrator to deliver HCl gas standards, record and 
report supporting data for these devices, including liquid feed 
calibrations, liquid standard(s) concentration, feed rate and gas 
flow calibrations for all diluent and HCl gas flows. All 
calibrations must include a stated uncertainty, and the combined 
uncertainty of the delivered gas concentration must be calculated 
and reported.
    11.10.2 Record and summarize in tabular form the results of the 
CD test, the linearity tests, the RT test, CE test, RA test, and 
optional spike recovery procedure, as appropriate. Include all data 
sheets, calculations, CEMS data records (i.e., charts, records of 
CEMS responses), and cylinder gas or other reference material 
certifications necessary to confirm that the performance of the CEMS 
met the performance specifications.
    11.10.3 Record and report supporting dilution system data 
including standard cylinder gas flow, total gas flow, and the 
results of the test measurements.
    11.10.4 Record and report the LOD and system limitation 
verification in ppmv for the HCl CEMS as installed.
    12.0 Calculations and Data Analysis.
    12.1 Nomenclature

Ci = Actual HCl calibration gas concentration used for 
test i (ppmv);
Ci,eff = Equivalent concentration of the reference value, 
Ci, at the specified conditions;
CC = Confidence coefficient;
CDextractive = Calibration drift for extractive CEMS 
(percent);
CDIP = Calibration drift for IP-CEMS (percent);
CD0 = The calibration drift at zero HCl concentrations 
for an IP-CEMS;
CEextractive = Calibration error for extractive CEMS 
(percent);
CEIP = Calibration error for IP-CEMS (percent);
davg = Mean difference between CEMS response and the 
reference gas (ppmv);
di = Difference of CEMS response and the RM value (ppmv);
I = Total interference from major matrix stack gases, percent;
LSM = Line strength factor for IP-CEMS, measurements, temperature 
dependent derivation from the HITRAN database;
[Delta]MCavg = Average of the 3 absolute values of the 
difference between the measured HCl calibration gas concentrations 
with and without interference from selected stack gases (ppmv);
MCi = Measured HCl calibration gas concentration i 
(ppmv);
MCint = Measured HCl concentration of the HCl calibration 
gas plus the individual or combined interference gases (ppmv);
MNavg = Average concentration at all sampling points 
(ppmv);
MNb = Measured native concentration bracketing 
calibration spike measurements;
MNi = Measured native concentration for test or run i 
(ppmv);
n = Number of measurements in an average value;
PLCell = Path length of IP-CEMS calibration cell;
PLStack = Path length of IP-CEMS stack optical path;
Ra = HCl concentration measured by the first of two RM 
pairs (ppmv);
Rb = HCl concentration measured by the second of two RM 
pairs (ppmv);
RA = Relative accuracy of CEMS compared to a RM (percent);
RD = Relative difference between paired RM trains (percent);
RMi = RM concentration for test run I;
RMavg = Mean measured RM value or the mean dynamic spike 
concentration (ppmv);
S = Span of the instrument (ppmv);
Sd = Standard deviation of the differences;
St = Stratification (percent);
t0.975 = One-sided t-value obtained from Table 5 for n-1 
measurements;
Treference = Temperature of the calibration cell for IP-
CEMS (degrees Kelvin);
Tstack = Temperature of the stack at the monitoring 
location for IP-CEM (degrees Kelvin).

    12.2 Calculate the difference between the measured HCl 
concentration with and without interferents for each interference 
gas (or mixture) for your CEMS as:
[GRAPHIC] [TIFF OMITTED] TP14MY14.014

    Calculate the total percent interference as:
    [GRAPHIC] [TIFF OMITTED] TP14MY14.015
    
    12.3 Calculate the calibration error or calibration drift at 
concentration i for an extractive CEMS as:
[GRAPHIC] [TIFF OMITTED] TP14MY14.016

    12.4 Calculate the calibration error or calibration drift at 
concentration i for IP-CEMS that use a calibration cell as follows:
    12.4.1 Calculate the equivalent concentration Ci,eff 
using Equation 4:

[[Page 27704]]

[GRAPHIC] [TIFF OMITTED] TP14MY14.017

    12.4.2 Calculate the average native concentration before and 
after a calibration check measurement as:
[GRAPHIC] [TIFF OMITTED] TP14MY14.018

    12.4.3 Calculate the calibration error or calibration drift at 
concentration i for an IP-CEMS as:
[GRAPHIC] [TIFF OMITTED] TP14MY14.019

    12.4.4 Calculate the calibration drift at zero HCl 
concentrations for an IP-CEMS as:
[GRAPHIC] [TIFF OMITTED] TP14MY14.020

    12.5 Calculate the percent stratification at each traverse point 
as:
[GRAPHIC] [TIFF OMITTED] TP14MY14.021

    12.6 Calculate the relative difference between paired RM 
sampling train results as:
[GRAPHIC] [TIFF OMITTED] TP14MY14.022

    12.7 Calculate the relative accuracy using RM and CEMS Data.
    12.7.1 Determine the HCl CEMS final integrated minute average 
pollutant concentration or emission rate for each RM test period. 
Consider system response time, if important, and confirm that the 
results have been corrected to the same moisture, temperature and 
diluent concentration basis.
    12.7.2 When Method 26A, found in 40 CFR part 60 Appendix A-8, is 
used as the RM, compare each CEMS integrated average value against 
the corresponding average of the paired RM values.
    12.7.3 If the RM is Method 320 or Method 321, found in 40 CFR 
part 63 Appendix A, or ASTM D6348-12, make a direct comparison of 
the average RM results and CEMS average value for identical test 
periods.
    12.7.4 Calculate the arithmetic difference of the RA 
measurements to the CEMS one-minute average results using Equation 
10.
[GRAPHIC] [TIFF OMITTED] TP14MY14.023

    12.7.5 Calculate the standard deviation of the differences (Sd) 
of the HCl CEMS measured and RM results using Equation 11.
[GRAPHIC] [TIFF OMITTED] TP14MY14.024

[[Page 27705]]

    12.7.6 Calculate the confidence coefficient (CC) for the 
relative accuracy tests using Equation 12.
[GRAPHIC] [TIFF OMITTED] TP14MY14.025

    12.7.7 Calculate the mean difference (davg) between the RM and 
CEMS values in the units of ppmv or the emission standard using 
Equation 13.
[GRAPHIC] [TIFF OMITTED] TP14MY14.026

    12.7.8 Calculate the average RM value using Equation 14.
    [GRAPHIC] [TIFF OMITTED] TP14MY14.027
    
    12.7.9 Calculate RA for the HCl CEMS using Equation 15.
    [GRAPHIC] [TIFF OMITTED] TP14MY14.028
    
    13.0 Method Performance.
    13.1 Level of Detection. You may not use an HCl CEMS whose LOD 
is greater than 20 percent of the regulatory limit or other action 
level for the intended use of the data. An LOD less than or equal to 
20 percent of the standard should result in 95 percent confidence 
level or better for measurements at the level of the standard.
    13.2 Calibration Drift. The calibration drift for the HCl CEMS 
must not drift or deviate from the reference gas value by more than 
five percent of the span value for seven consecutive days.
    13.3 Calibration Error Check (linear or quadratic)
    13.3.1 The calibration intercept must be equal to or less than 
15 percent of the system span.
    13.3.2 The mean percent difference between the reference gas 
value and the CEMS measured concentration at each of the three 
points (Eq.7) must be less than five percent of span.
    13.4 Relative Accuracy Check--Reference Method. The RA of the 
CEMS compared to a RM in the units of the HCl concentration must be 
less than or equal to 20 percent of the RM when RMavg is used in the 
denominator of Equation 14. In cases where the average emission 
level for the test is less than 50 percent of the applicable 
standard, substitute the equivalent emission standard value in ppmvw 
in the denominator of Equation 14 in place of RMavg, and this 
alternative calculated RA must be less than or equal to 15 percent 
of the RM.
    13.5 Response Time.
    13.5.1 The RT to a measurable change in concentration must be 
less than or equal to 15 minutes.
    13.5.2 Interference Check. The combined interference response 
for the HCl CEMS that was used for the test must not be greater than 
3.0 percent of the equivalent HCl concentration used for 
the interference test.
    13.5.3 Integrated Path Beam Intensity. The percent difference 
during attenuated light calibration check for the light source and 
detector used in an IP-CEMS must not be more than 3.0 
percent of the known measured concentration without attenuation used 
for the test.
    13.5.4 Your temperature monitor satisfies the accuracy required 
if the absolute relative difference between Mt and 
Vt is <= one percent or if the absolute difference 
between measured value of stack temperature (Mt) and the 
value of calibrated temperature reference device (Vt) is 
<=2.8 [deg]C (5.0 [deg]F), whichever is greater.
    13.5.5 Your pressure monitor satisfies the accuracy required if 
the absolute relative difference between MP and the value 
of calibrated pressure reference device (VP) is <= five 
percent or if the absolute difference between the measured value of 
stack pressure (Mp and VP) is <=0.12 
kilopascals (0.5 inches of water column), whichever is greater.
    14.0 Pollution Prevention. [Reserved]
    15.0 Waste Management. [Reserved]
    16.0 References.

1. Method 318, 40 CFR, part 63, Appendix A (Draft), ``Measurement of 
Gaseous Formaldehyde, Phenol and Methanol Emissions by FTIR 
Spectroscopy,'' EPA Contract No. 68D20163, Work Assignment 2-18, 
February, 1995.
2. ``EPA Protocol for the Use of Extractive Fourier Transform 
Infrared (FTIR) Spectrometry in Analyses of Gaseous Emissions from 
Stationary Industrial Sources,'' February, 1995.
3. ``Measurement of Gaseous Organic and Inorganic Emissions by 
Extractive FTIR Spectroscopy,'' EPA Contract No. 68-D2-0165, Work 
Assignment 3-08.
4. ``Method 301--Field Validation of Pollutant Measurement Methods 
from Various Waste Media,'' 40 CFR part 63, Appendix A.
5. EPA Traceability Protocol for Assay and Certification of Gaseous 
Calibration Standards 2012. See www.epa.gov/ttn/emc.

    17.0 Tables, Diagrams, Flowcharts, and Validation Data.

             Table 1--Interference Check Gas Concentrations
------------------------------------------------------------------------
                                             Approximate  concentration
       Potential interferent gas \1\             (balance N[ihel2])
------------------------------------------------------------------------
CO[ihel2].................................  15%  1%
                                             CO[ihel2].\2\
CO........................................  100  20 ppm.
CH[ihel2]O................................  20 ppm.
CH[ihel4].................................  100  20 ppm.
NH[ihel3].................................  10 ppm (extractive CEMS
                                             only).
NO[ihel2].................................  250  50 ppm.
SO[ihel2].................................  200  20 ppm.
O[ihel2]..................................  3%  1%
                                             O[ihel2].\2\
H[ihel2]O.................................  10%  1%
                                             H[ihel2]O.\2\
N[ihel2]..................................  Balance.\2\
------------------------------------------------------------------------
\1\ Any of these specific gases can be tested at a lower level if the
  manufacturer has provided reliable means for limiting or scrubbing
  that gas to a specified level.
\2\ Gases for short path IP cell interference tests added at relative
  concentration ratios indicated in the table.

[[Page 27706]]

                                                      Table 2--Example Interference Test Data Sheet
 
 

Date of Test:----------------------------------------------------------
Analyzer Type:---------------------------------------------------------
Model No.:-------------------------------------------------------------
Serial No.:------------------------------------------------------------
Span:------------------------------------------------------------------
Calibration Range Above Span:------------------------------------------
Test Organization:-----------------------------------------------------
Test Personnel:--------------------------------------------------------

----------------------------------------------------------------------------------------------------------------
                                                HCl  concentration
 Interference gas or     HCl  concentration         (ppmv)  w/        Absolute  difference    Average absolute
   gas combination             (ppmv)              interference              (ppmv)           difference (ppmv)
----------------------------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
                       .....................  .....................  .....................  ....................
                      ------------------------------------------------------------------------------------------
    Sum of Responses
----------------------------------------------------------------------------------------------------------------
% of Calibration Span
----------------------------------------------------------------------------------------------------------------

            Table 3--Design Standards for Temperature Sensors
------------------------------------------------------------------------
                                        You can use the following design
       If the sensor is a . . .             standards as guidance in
                                        selecting a sensor for your CPMS
------------------------------------------------------------------------
1. Thermocouple......................  a. ASTM E235-88 (1996),
                                        ``Specification for
                                        Thermocouples, Sheathed, Type K,
                                        for Nuclear or Other High-
                                        Reliability Applications.''

[[Page 27707]]

 
                                       b. ASTM E585/E585M-04,
                                        ``Specification for Compacted
                                        Mineral-Insulated, Metal-
                                        Sheathed, Base Metal
                                        Thermocouple Cable.''
                                       c. ASTM E608/E608M-06,
                                        ``Specification for Mineral-
                                        Insulated, Metal-Sheathed Base
                                        Metal Thermocouples.''
                                       d. ASTM E696-07, ``Specification
                                        for Tungsten-Rhenium Alloy
                                        Thermocouple Wire.''
                                       e. ASTM E1129/E1129M-98 (2002),
                                        ``Standard Specification for
                                        Thermocouple Connectors.''
                                       f. ASTM E1159-98 (2003),
                                        ``Specification for Thermocouple
                                        Materials, Platinum-Rhodium
                                        Alloys, and Platinum.''
                                       g. ISA-MC96.1-1982, ``Temperature
                                        Measurement Thermocouples.''
------------------------------------------------------------------------
2. Resistance temperature detector...  ASTM E1137/E1137M-04, ``Standard
                                        Specification for Industrial
                                        Platinum Resistance
                                        Thermometers.''
------------------------------------------------------------------------

                         Table 4--Performance Specification Test Calibration Gas Ranges
----------------------------------------------------------------------------------------------------------------
                                                         HCl calibration material concentrations \a\
                                                      ------------------------------------------------
              Test                       Units                                                 High     Section
                                                            Zero      Low level  Mid level    level
----------------------------------------------------------------------------------------------------------------
Calibration Drift...............  % of Span..........   2.0 percent accuracy or calculate the flow using a stable 
tracer gas included in your spike gas standard.
    8.2.4.2 If you use flow measurements to determine the spike 
dilution, then use equation A1 in section 11 of this appendix to 
calculate the DF. Total probe flow measurement requires measurement 
of HCl spike flow (Qspike) and total flow through the CEM 
sampling system (Qprobe).
    8.2.4.3 If your CEMS is capable of measuring an independent 
stable tracer gas, you may use a spike gas that includes the tracer 
to determine the DF using equation A2 in section 11 of this 
appendix.
    8.2.5 Begin by collecting unspiked sample measurements. You must 
use the average of two unspiked sample measurements as your pre-
spike background.
    (Note: Measurements should agree within five percent or three 
times the level of detection to avoid biasing the spike recovery 
results.)
    8.2.5.1 Introduce the HCl gas spike into the permanent CEMS 
probe, upstream of the particulate filter or sample conditioning 
system and as close to the sampling inlet as practical.
    8.2.5.2 Maintain the HCl gas spike for at least twice the 
response time of your CEMS or until the consecutive measurements 
agree within five percent. Collect two independent measurements of 
the native plus spiked HCl concentration.
    8.2.5.3 Stop the flow of spike gas for at least twice the 
response time of your CEMS or until the consecutive measurements 
agree within five percent. Collect two independent measurements of 
the native HCl concentration.
    8.2.6 Repeat the collection of sample measurements in section 
8.2.5 until you have data for each spike concentration for a total 
of nine sets of data including a final set of unspiked sample 
measurements according to section 8.2.5.
    8.2.7 Calculate the percent recovery for extractive CEMS as 
described in section 11.2 of this appendix.
    8.2.8 If the spikes persistently show poor recovery 
repeatability, or if the recoveries are not within the range 
specified in section 12 of this appendix, you must take corrective 
action and repeat the dynamic spiking accuracy procedure.
    8.3 Dynamic Spiking Procedure for IP-CEMS.
    8.3.1 For IP-CEMS, you must spike a known quantity of 
calibration gas into a calibration cell that is in the optical path 
used to make CEMS source measurements.
    8.3.2 Use calibration gas at a concentration that produces a 
signal equivalent to the ranges specified in Table 4 of PS-18.
    8.3.3 Introduce zero gas into a permanently mounted calibration 
cell located in the optical measurement path of the instrument. 
Continue to flush the zero gas into the cell for at least the 
response time of your CEMS or until two consecutive measurements 
taken are within five percent, then collect two independent 
measurements. Introduce spike gas into the same calibration cell. 
Continue to flush the spike gas into the cell for at least the 
response time of your CEMS or until two consecutive measurements 
taken are within five percent. Then collect two independent 
measurements.
    8.3.4 Repeat the collection of sample spike and native HCl 
measurements in section 8.3.3 until you have data for each spike 
concentration for a total of nine sets of data including a final 
zero gas sample measurement. The measured concentrations must be 
corrected for calibration cell and stack temperature, pressure and 
stack measurement path length.
    8.3.5 Calculate the percent spike recovery (%SA) for IP-CEMS, as 
described in section 11.2.3.5, using the appropriate equations in 
section 11.2 of this appendix.
    8.3.6 If the spikes persistently show poor repeatability, or if 
the recoveries are not within the range specified in section 12 of 
this appendix, you must take corrective action and repeat the 
dynamic spiking accuracy procedure.
    A9. Quality Control. (Reserved)
    A10. Calibration and Standardization. (Reserved)
    A11. Calculations and Data Analysis. Calculate the spike 
recoveries for each injection and its associated pair of native HCl 
measurements, using equations in this section. (Note: For cases 
where the emission standard is expressed in units of lb/MMBtu or 
corrected to a specified O2 or CO2 
concentration, an absolute accuracy specification based on a span at 
stack conditions may be calculated using the average concentration 
and applicable conversion factors. The appropriate procedures for 
use in cases where a percent removal standard is more restrictive 
than the emission standard are the same as in 40 CFR part 60 PS-2, 
sections 12 and 13.)
    11.1 Nomenclature

Ci = Actual HCl calibration gas concentration used for 
test i (ppmv);
Ci,eff = Spike equivalent concentration of the reference 
value, Ci, at the specified conditions;
Cspike gas = Actual HCl standard gas concentration spiked (e.g., 
bottle or standard gas concentration) ppmv;
Ctracer spiked = Tracer gas concentration injected with spike gas 
(``standard concentration'') ppmv;
Cexpected = Expected HCl concentration response for dynamic spike;
CC = Confidence coefficient;
DF = Spiked gas dilution factor;
LSM = Line strength factor for integrated path; measurements, 
temperature dependent derivation from the HITRAN database (see 
http://www.cfa.harvard.edu/hitran/ for HITRAN access);
MCi = Measured HCl calibration gas concentration i 
(ppmv);
MCnative = Average measured concentration of the native 
HCl (ppmv);
Mnative tracer = Measured tracer gas concentration 
present in native effluent gas (ppmv);
Mspiked tracer = Measured diluted tracer gas 
concentration in a spiked sample (ppmv);
n = Number of measurements in an average value;
PLCell = Path length of IP-CEMS calibration cell;
PLStack = Path length of IP-CEMS stack optical path;
Qspike = Flow rate of the dynamic spike gas (Lpm);
Qprobe = Average total stack sample flow through the 
system (Lpm);
S = Span;
%SA = Spike recovery accuracy (percent);
%SRavg = Mean dynamic spike recovery (percent);
%SRi = Dynamic spike recovery (percent);
Sd = Standard deviation of the differences;
t0.975 = One-sided Students t-value n-1 measurements;
Tstack = Temperature of the stack gas;
Treference = Temperature measured by the reference 
temperature indicator.

    11.2 Calculating Dynamic Spike Recovery for Extractive CEMS.
    11.2.1 If you determine your spike dilution factor using spike 
gas and stack sample flow measurements, calculate the dilution 
factor for dynamic spiking accuracy tests using equation A1:

[[Page 27710]]

[GRAPHIC] [TIFF OMITTED] TP14MY14.000

    11.2.2 If you determine your spike dilution factor using an 
independent stable tracer gas that is not present in the native 
source gas, calculate the dilution factor for dynamic spiking using 
equation A2:
[GRAPHIC] [TIFF OMITTED] TP14MY14.001

    11.2.3 If you determine your spike dilution factor using an 
independent stable tracer that is present in the native source gas, 
calculate the dilution factor for dynamic spiking using equation A3:
[GRAPHIC] [TIFF OMITTED] TP14MY14.002

    11.2.3.1 Calculate the percent spike recovery (SRi) 
between the CEMS results and the spike gas concentration for each 
spiked sample measurement using equation A4.
[GRAPHIC] [TIFF OMITTED] TP14MY14.003

    11.2.3.2 You must calculate the mean of the recovery for the 
nine (or more) dynamic spikes using equation A5.
[GRAPHIC] [TIFF OMITTED] TP14MY14.004

    11.2.3.3 You must calculate the standard deviation of the spike 
recoveries for the nine (or more) dynamic spiking measurements to 
determine CEMS accuracy using equation A6.
[GRAPHIC] [TIFF OMITTED] TP14MY14.005

    11.2.3.4 Calculate the confidence coefficient (CC) for the 
relative accuracy tests using equation A7.
[GRAPHIC] [TIFF OMITTED] TP14MY14.006

    11.2.3.5 Calculate the percent %SA for the extractive CEMS using 
equation A8.
[GRAPHIC] [TIFF OMITTED] TP14MY14.007

    11.3 DS Recovery for IP-CEMS.
    11.3.1 If you use an in-situ IP-CEMS and a calibration cell, 
calculate and substitute the spike equivalent concentration 
Ci,eff for Cspike using equation A9:

[[Page 27711]]

[GRAPHIC] [TIFF OMITTED] TP14MY14.008

    11.3.2 Calculate the percent spike equivalent recovery 
(%SRi) between the CEMS results and the spike equivalent 
concentration for each spiked sample measurement using equation A10.
[GRAPHIC] [TIFF OMITTED] TP14MY14.009

    11.3.3 Calculate the average spike recovery (SRavg) 
using equation A11.
[GRAPHIC] [TIFF OMITTED] TP14MY14.010

    11.3.4 Calculate the standard deviation of the spike recoveries 
for the nine (or more) dynamic spiking measurements to determine 
CEMS accuracy using equation A12.
[GRAPHIC] [TIFF OMITTED] TP14MY14.011

    11.3.5 Calculate the confidence coefficient (CC) for the spiking 
accuracy using equation A13.
[GRAPHIC] [TIFF OMITTED] TP14MY14.012

    11.3.6 Calculate the relative spike recovery accuracy (%SA) for 
the IP-CEMS using equation A14.
[GRAPHIC] [TIFF OMITTED] TP14MY14.013

    A12. Performance Requirements DS Spike Accuracy Check.
    12.1 The %SA of the average CEMS results calculated using 
equation A8 for extractive CEMS or equation A14 for IP-CEMS in the 
units of HCl concentration (ppm) must be less than or equal to 25 
percent of (the average of) the spiked sample concentration.
    A13. Tables and Figures.

                   Table 1--Spike Recovery Work Sheet
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Facility name:                       Date: Time:
------------------------------------------------------------------------
Unit(s) tested:                      Test personnel:
------------------------------------------------------------------------
Analyzer make and model:             ...................................
                                    ------------------------------------
Serial number:                       ...................................
                                    ------------------------------------
Calibration range above span:        ...................................
------------------------------------------------------------------------

[[Page 27712]]

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                           Cnative                           Actual Values
                                     Qspike                -------------------------------------------------------------------------     SR (% spike
          Qprobe (lpm)               (lpm)        CF\1\                                               Ci\2\                               recovery)
                                                                Pre          Post         Avg         (ppmv)       MCss\3\ (ppmv)
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                  ...........  ...........  ...........  ...........  ...........  ...........  Average              ...................
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                  ...........  ...........  ...........  ...........  ...........  ...........  SD                   ...................
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ CF must be >= 10 for extractive CEMS.
\2\ Ci = Actual HCl concentration of the spike gas, ppmv.
\3\ MCss = Measured HCl concentration of the spiked sample at the target level, ppmv.

0
3. Appendix F to part 60 is amended by adding Procedure 6 to read as 
follows:

Appendix F to Part 60--Quality Assurance Procedures

* * * * *
    Procedure 6. Quality Assurance Requirements for Gaseous Hydrogen 
Chloride (HCl) Continuous Emission Monitoring Systems Used for 
Compliance Determination at Stationary Sources
    1.0 Applicability and Principle.
    1.1 Applicability. Procedure 6 is used to evaluate the 
effectiveness of quality control (QC) and quality assurance (QA) 
procedures and evaluate the quality of data produced by any hydrogen 
chloride (HCl) gas, CAS: 7647-01-0, continuous emission monitoring 
system (CEMS) that is used for determining compliance with emission 
standards for HCl on a continuous basis as specified in an 
applicable permit or regulation.
    1.1.1 This procedure specifies the minimum QA requirements 
necessary for the control and assessment of the quality of CEMS data 
submitted to the Environmental Protection Agency (EPA). Source 
owners and operators responsible for one or more CEMS used for HCl 
compliance monitoring must meet these minimum requirements and are 
encouraged to develop and implement a more extensive QA program or 
to continue such programs where they already exist.
    1.1.2 Data collected as a result of QA and QC measures required 
in this procedure are to be submitted to the EPA or the delegated 
authority. These data are to be used by both the responsible agency 
and the CEMS operator in assessing the effectiveness of the CEMS QC 
and QA procedures in the maintenance of acceptable CEMS operation 
and valid emission data.
    1.2 Principle.
    1.2.1 The QA procedures consist of two distinct and equally 
important functions. One function is the assessment of the quality 
of the HCl CEMS data by estimating accuracy. The other function is 
the control and improvement of the quality of the CEMS data by 
implementing QC policies and corrective actions. These two functions 
form an iterative control loop. When the assessment function 
indicates that the data quality is inadequate, the control effort 
must be increased until the data quality is acceptable. In order to 
provide uniformity in the assessment and reporting of data quality, 
this procedure specifies the assessment procedures to evaluate 
response drift and accuracy. The procedures specified are based on 
Performance Specification 18 (PS-18) in appendix B of this part. 
Procedure 6 also requires the analysis of reference method audit 
samples, if they are available, concurrently with reference method 
tests as specified in the general provisions of the applicable part. 
(Note: Because the control and corrective action function 
encompasses a variety of policies, specifications, standards and 
corrective measures, this procedure treats QC requirements in 
general terms to allow each source owner or operator to develop the 
most effective and efficient QC system for their circumstances.)
    2.0 Definitions.
    2.1 Calibration Cell means a gas containment cell used with 
cross stack or integrated path (IP) monitoring systems to perform 
precision and calibration checks. The cell may be a removable sealed 
cell or an evacuated and/or purged cell capable of exchanging 
calibration and zero gases. When charged for calibration, the 
calibration cell contains a known concentration of calibration gas. 
The calibration cell is filled with zero gas or removed from the 
optical path during normal stack gas measurement.
    2.2 Calibration Drift (CD) means the absolute value of the 
difference between the CEMS output response and an upscale reference 
gas or a zero-level reference gas, expressed as a percentage of the 
span value, when the CEMS is challenged after a stated period of 
operation during which no unscheduled maintenance or repair took 
place. A separate CD determination must be performed for pollutant 
and diluent analyzers. The calibration standards must meet the 
requirements of section 7.0 in PS-18 of Appendix B in this part.
    2.3 Continuous Emission Monitoring System (CEMS) means the total 
equipment required under the emission monitoring sections in 
applicable subparts, used to sample and condition (if applicable), 
to analyze, and to provide a permanent record of emissions or 
process parameters.
    2.4 Diluent Gas means a major gaseous constituent in a gaseous 
pollutant mixture. For combustion sources, either carbon dioxide 
(CO2) or oxygen (O2) or a combination of these 
two gases are the major gaseous diluents of interest.
    2.5 Dynamic Spiking (DS) means, for extractive CEMS, the 
procedure where a known concentration of HCl gas is injected into 
the sample gas stream at the probe with a known flow rate; for in-
situ IP-CEMS, it is a procedure where a known concentration of HCl 
gas is spiked into a calibration cell. In both cases, the procedure 
is performed to assess the accurate recovery of HCl introduced into 
the measurement system in the presence of potential interference 
from the flue gas sample matrix.
    2.6 Liquid Evaporative Standard means a calibration standard 
produced by vaporizing National Institute of Standards and Testing 
(NIST) traceable liquid standards of known

[[Page 27713]]

HCl concentration and quantitatively mixing the resultant vapor with 
a diluent carrier gas.
    2.7 Span Value means the calibration portion of the measurement 
range as established by the applicable regulatory requirement. If 
the span is not specified by an applicable regulation or other 
requirement, then it must be equal to an instrument value 
representative of twice the emission limit.
    2.8 HCl concentration values (Zero, Low-Level, Mid-Level and 
High-Level Values) means the values that are defined in Table 4 of 
PS-18 in Appendix B of this part.
    2.9 Relative Accuracy (RA) means the value calculated using 
Equation 15 of PS-18 in Appendix B of this part or as specified in 
an applicable regulation. The RA is the absolute mean difference 
between the gas concentration determined by the CEMS and the value 
determined by the reference method (RM), plus the 2.5 percent error 
confidence coefficient of a series of tests divided by the average 
of the RM or the applicable emission standard.
    3.0 QC Plan Requirements.
    3.1 Each source owner or operator must develop and implement a 
QC program. As a minimum, each QC program must include written 
procedures and/or manufacturer's information which should describe 
in detail, complete, step-by-step procedures and operations for each 
of the following activities:
    (a) CD checks of HCl CEMS;
    (b) CD determination and adjustment of HCl CEMS;
    (c) Integrated path HCl CEMS emission source (e.g., stack) 
temperature and pressure accuracy;
    (d) Integrated path HCl CEMS beam intensity checks;
    (e) Routine and preventative maintenance of HCl CEMS (including 
spare parts inventory);
    (f) Data recording, calculations, and reporting;
    (g) Accuracy audit procedures for HCl CEMS including sampling 
and analysis methods; and
    (h) Program of corrective action for malfunctioning HCl CEMS.
    3.2 These written procedures must be kept on record and 
available for inspection by the enforcement agency. As described in 
section 5.3, whenever excessive inaccuracies occur for two 
consecutive quarters, the source owner or operator must revise the 
current written procedures or modify or replace the CEMS to correct 
the deficiency causing the excessive inaccuracies.
    4.0 Daily Quality Requirements, Calibration and Measurement 
Standardization Procedures.
    4.1 CD Assessment.
    4.1.1 CD Requirement. As described in 40 CFR 60.13(d) and 
63.8(c), source owners and operators of HCl CEMS must check, record, 
and quantify the CD at two concentration values and at the 
calibration range above span (CRAS) concentration value at least 
once daily (approximately 24 hours) in accordance with the method 
prescribed by the manufacturer. The HCl CEMS calibration must, at a 
minimum, be adjusted whenever the daily zero (or low-level) CD or 
the daily high-level CD exceeds two times the drift limits of the 
applicable performance specification (e.g., PS-18 in Appendix B to 
this part).
    4.1.2 Recording Requirement for Automatic CD Adjusting CEMS. A 
CEMS that automatically adjusts the data to the corrected 
calibration values (e.g., microprocessor control) must be programmed 
to record the unadjusted concentration measured in the CD prior to 
resetting the calibration, if performed, or record the amount of 
adjustment.
    4.1.3 Criteria for Excessive CD. If either the zero (or low-
level) or high-level CD result exceeds twice the drift requirement 
in the applicable performance specification in Appendix B of this 
part for five consecutive daily periods, the CEMS is out-of-control. 
If either the zero (or low-level) or high-level CD result exceeds 
four times the applicable drift specification during any CD check, 
the CEMS is out-of-control. If the CEMS is out-of-control, take 
necessary corrective action. Following corrective action, repeat the 
CD checks.
    4.1.4 Out-Of-Control Period Definition. The beginning of the 
out-of-control period for the CEMS calibration is the time 
corresponding to the completion of the fifth consecutive daily check 
with a CD in excess of two times the allowable limit, or the time 
corresponding to the completion of the daily CD check preceding the 
daily CD check that results in a CD in excess of four times the 
allowable limits. The end of the out-of-control period is the time 
corresponding to the completion of the CD check following corrective 
action that results in the CDs at both the zero (or low-level) and 
high-level measurement points being within the corresponding 
allowable CD limit (i.e., either two times or four times the 
allowable limit of the applicable rule).
    4.2 Beam Intensity Requirement for HCl integrated path-CEMS (IP-
CEMS).
    4.2.1 Beam Intensity Verification. Source owners and operators 
of HCl IP-CEMS must quantify and record the beam intensity of their 
IP-CEMS in appropriate units at least once daily (approximately 24 
hours apart) according to manufacturer's specifications and 
procedures.
    4.2.2 Criteria for Excessive Beam Intensity Loss. If the beam 
intensity falls below the level established for the operation range 
determined following the procedures in section 11.2 of PS-18 of this 
part, then the HCl CEMS is out-of-control. This quality check is 
independent of whether the HCl CEMS daily calibration drift is 
acceptable. If the HCl CEMS is out-of-control, take necessary 
corrective action. Following corrective action, repeat the beam 
intensity check.
    4.3 CEMS Data Status During Out-of-Control Period. During the 
period the CEMS is out-of-control, the CEMS data may not be used in 
calculating compliance with an emissions limit nor be counted 
towards meeting minimum data availability as required and described 
in the applicable regulation or permit.
    5.0 Data Accuracy Assessment.
    Each CEMS must be audited at least once each calendar quarter. 
Successive quarterly audits shall occur no closer than two months.
    5.1 Temperature and Pressure Accuracy Assessment for IP CEMS.
    5.1.1 Stack or source gas temperature measurement audits for HCl 
IP-CEMS must be conducted and recorded at least quarterly in 
accordance with the procedure described in section 11.3 of PS-18 in 
Appendix B of this part. Any measurement instrument or device that 
is used to conduct ongoing verification of temperature measurement 
must have an accuracy that is traceable to NIST.
    5.1.2 Stack or source gas pressure measurements for HCl IP-CEMS 
must be checked and recorded at least quarterly in accordance with 
the procedure described in section 11.4 of PS-18 in Appendix B of 
this part. Any measurement instrument or device that is used to 
conduct ongoing verification of pressure measurement must have an 
accuracy that is traceable to NIST.
    5.1.3 Excessive Parameter Verification Inaccuracy. If the 
temperature or pressure verification exceeds the criteria in section 
5.3.5, the HCl CEMS is out-of-control. If the CEMS is out-of-
control, take necessary corrective action to eliminate the problem. 
Following corrective action, the source owner or operator must 
repeat the failed verification to determine if the HCl CEMS is 
operating within the specifications.
    5.2 Concentration Accuracy Auditing Requirements. The accuracy 
of each HCl CEMS must be audited at least once each calendar quarter 
(except the quarter the relative accuracy audit test (RATA) is 
conducted) by dynamic spiking audit (DSA), a cylinder gas audit 
(CGA), a relative accuracy audit (RAA), or other acceptable 
alternative. Successive quarterly audits must occur no closer than 
two months apart. The accuracy audits shall be conducted as follows:
    5.2.1 Relative Accuracy Test Audit. The RATA must be conducted 
at least once every four calendar quarters, except as otherwise 
noted in section 5.2.5 of this procedure. Unless otherwise specified 
in an applicable regulation or permit, conduct the RATA during 
process operating conditions representing average production and 
full control operation at the source as specified in section 11.9.4 
of PS-18 in Appendix B of this part.
    5.2.1.1 Repeating the stratification test in section 11.9.3 is 
not required unless the flow path of the emission stream has been 
altered or changed since the initial RATA.
    5.2.1.2 You must analyze and pass the appropriate performance 
audit samples for the reference method (i.e., Method 26 and Method 
26A) as described in the general provisions to the applicable part 
(e.g. 40 CFR part 60 or 63).
    5.2.1.3 If the measured source concentration during a RATA is 20 
percent or less than the applicable emission standard, you must 
perform a CGA or a DSA for at least one subsequent (one of the 
following three) quarterly audits.
    5.2.2 Quarterly Cylinder Gas Audit. A quarterly CGA may be 
conducted as an option to conducting a RATA in three of four 
calendar quarters, but in no more than three quarters in succession.
    5.2.2.1 To perform a CGA, challenge the CEMS with a zero-level 
and two upscale

[[Page 27714]]

level audit gases of known concentrations within the following 
ranges:

------------------------------------------------------------------------
                Audit point                          Audit range
------------------------------------------------------------------------
1 (Mid-Level).............................  50 to 60% of span value.
2 (High-Level)............................  80 to 120% of span value.
------------------------------------------------------------------------

    5.2.2.2 Sequentially inject each of the three audit gases (zero 
and two upscale) three times each for a total of nine injections. 
Inject the gases in such a manner that the entire CEMS is 
challenged. Do not inject the same gas concentration twice in 
succession.
    5.2.2.3 Use HCl audit gases that are NIST certified or NIST 
traceable. Cylinder gases must be certified accurate to a tolerance 
of five percent or less.
    5.2.2.4 Calculate results as described in section 6.3.
    5.2.3 Dynamic Spiking Audit (DSA). A DSA may be conducted as an 
option to a RATA in three of four calendar quarters, but in no more 
than three quarters in succession.
    5.2.3.1 To conduct a DSA, you must conduct the dynamic spiking 
procedure as described in Appendix A to PS-18 of Appendix B to this 
part.
    5.2.3.2 You must calculate the mean and relative standard 
deviation for dynamic spiking measurements to determine CEMS 
accuracy.
    5.2.3.3 For extractive HCl CEMS, you must perform the DSA by 
passing the spiked source gas through all filters, scrubbers, 
conditioners and other monitoring system components used during 
normal sampling, and as much of the sampling probe as is practical. 
For IP-CEMS, you must perform the DSA by adding or passing a known 
concentration calibration gas into a calibration cell in the optical 
path of the CEMS. You must include the source measurement optical 
path while performing a DSA using an IP-CEMS.
    5.2.4 Relative Accuracy Audit (RAA). As an alternative to a CGA 
or DSA, an RAA may be conducted in one to three of four calendar 
quarters. To conduct an RAA, follow the RATA test procedures in 
section 11.9 of PS-18 in Appendix B to this part, except that only 
three test runs are required.
    5.2.5 Other Alternative Quarterly Audits. Other alternative 
audit procedures, as approved by the Administrator, may be used for 
three of four calendar quarters. One RATA is required at least every 
four calendar quarters, except in the case where the affected 
facility is off-line (does not operate in the fourth calendar 
quarter since the quarter of the previous RATA). In that case, the 
RATA shall be performed in the quarter in which the unit recommences 
operation. Also, a CGA, DSA, RAA, or RATA is not required for 
calendar quarters in which the affected facility does not operate.
    5.3 Excessive Audit Inaccuracy. If the results of the RATA, the 
DSA, CGA, or RAA exceed the criteria in section 5.3.5, the HCl CEMS 
is out-of-control. If the CEMS is out-of-control, take necessary 
corrective action to eliminate the problem. Following corrective 
action, the source owner or operator must audit the CEMS with a 
RATA, DSA, CGA, or RAA to determine if the HCl CEMS is operating 
within the specifications.
    5.3.1 A RATA must always follow an out-of-control period 
resulting from a RATA.
    5.3.2 If the audit results show the CEMS to be out-of-control, 
the CEMS operator shall report both the audit showing the CEMS to be 
out-of-control and the results of the audit following corrective 
action showing the CEMS to be operating within specifications.
    5.3.3 Out-Of-Control Period Definition. The beginning of the 
out-of-control period is the time corresponding to the completion of 
the sampling for the failed RATA, CGA or DSA. The end of the out-of-
control period is the time corresponding to the completion of the 
sampling of the subsequent successful audit.
    5.3.4 CEMS Data Status During Out-Of-Control Period. During the 
period the CEMS is out-of-control, the CEMS data may not be used in 
calculating emission compliance nor be counted towards meeting 
minimum data availability as required and described in the 
applicable regulation or permit.
    5.3.5 Criteria for Excessive Quarterly Test Inaccuracy. Unless 
specified otherwise in the applicable regulation or permit, the 
criteria for excessive inaccuracy are:
    (a) For the RATA, the allowable RA is equal to 20 percent of the 
RM when RMavg is used in the denominator of equation 15 
in PS-18 of Appendix B to this part. In cases where the average 
emission level for the test is less than 50 percent of the 
applicable standard, you may substitute the equivalent emission 
standard value (in ppmvw) in the denominator of equation 15 in the 
place of RMavg and this alternative calculation of RA 
must be less than or equal to 15 percent of the RM.
    (b) For CGA, the allowable calibration error in PS-18 of 
Appendix B to this part is applicable (less than five percent of 
span).
    (c) For the DSA, the allowable RA is + 15 percent of the average 
spike value or  20 percent of the applicable emission 
standard at source conditions under the production rate during the 
time of the DSA, whichever is greater.
    (d) For temperature verification, the CEMS must satisfy the 
requirements in section 13.5.4 in PS-18 of Appendix B to this part.
    (e) For pressure verification, the CEMS must satisfy the 
requirements in section 13.5.5 in PS-18 of Appendix B to this part.
    5.4 Criteria for Acceptable QC Procedures. Repeated excessive 
inaccuracies (i.e., out-of-control conditions resulting from the 
quarterly audits) indicate that the QC procedures are inadequate or 
that the CEMS is incapable of providing quality data. Therefore, 
whenever excessive inaccuracies occur for two consecutive quarters, 
the source owner or operator must revise the QC procedures (see 
section 3.0) or modify or replace the CEMS.
    5.5 Criteria for Optional QA Test Frequency. If all the quality 
criteria are met in section 4 and 5 of this procedure, the CEMS is 
in-control.
    5.5.1 If the CEMS is in-control and if the source releases <= 75 
percent of the HCl emission limit for eight consecutive quarters 
that include a minimum of two RATA, the source owner or operator may 
revise their auditing procedures to use CGA, RAA or DSA each quarter 
for eight subsequent quarters following a RATA.
    5.5.2 The source owner or operator must perform at least one 
RATA that meets the acceptance criteria every two years.
    If the source owner or operator fails a RATA, CGA, or DSA, then 
the audit schedule in section 5.2 must be followed until the audit's 
results meet the criteria in section 5.3.5 to start requalifying for 
the optional QA test frequency in section 5.5.
    6.0 Calculations for CEMS Data Accuracy.
    6.1 RATA RA Calculation. Follow equation 15 in Section 12 of PS-
18 in Appendix B to this part to calculate the RA for the RATA. The 
RATA must be calculated in units of the applicable emission 
standard.
    6.2 CGA Accuracy Calculation. For each reference gas 
concentration, determine the average of the three CEMS responses and 
subtract the average response for the reference gas value. For 
extractive HCl CEMS, calculate the measurement error at each gas 
level using Equation 3 in section 12.3 of PS-18 in Appendix B to 
this part. For IP-CEMS, calculate the measurement error at each gas 
level using Equation 6 in section 12.6 of PS-18. Calculate CGA 
accuracy in units of the appropriate concentration (e.g., ppmvd, lb/
MWhr, lb/MMBtu).
    6.3 DSA Accuracy Calculation.
    6.3.1 For extractive HCl CEMS, use the equations described in 
section 11.2 in Appendix A of PS-18 of this part to calculate the 
accuracy for the dynamic spike accuracy assessment. The DSA reported 
as the percent spike recovery accuracy (%SA) must be calculated in 
units of the applicable emission standard (e.g., ppmv).
    6.3.2 For HCl IP-CEMS, use the equations described in section 
11.3 in Appendix A of PS-18 to this part to calculate the accuracy 
for the dynamic spike accuracy assessment for IP-CEMS. The DSA 
reported as the percent spike recovery accuracy (%SA) must be 
calculated in units of the applicable emission standard (e.g., 
ppmvd, lb/MWhr, lb/MMBtu).
    7.0 Reporting Requirements.
    At the reporting interval specified in the applicable regulation 
or permit, report for each CEMS the accuracy results from section 6 
and the CD assessment results from section 4.
    7.1 Report the drift and accuracy information as a Data 
Assessment Report (DAR), and include one copy of this DAR for each 
quarterly audit with the report of emissions required under the 
applicable subparts of this part or other applicable regulations or 
permits. An example of a DAR format is shown in Figure 1.
    7.1.1 At a minimum, the DAR must contain the following 
information:
    a. Source owner or operator name and address.
    b. Identification and location of monitors in the CEMS.
    c. Manufacturer and model number of each monitor in the CEMS.
    d. Assessment of CEMS data accuracy and date of assessment as 
determined by a RATA, CGA or DSA described in section 5 including:
     The RA for the RATA;
     The RA for the CGA or DSA;
     Beam intensity results for IP-CEMS;

[[Page 27715]]

     The RM results, the cylinder gases certified values;
     The CEMS responses;
     The calculations results as defined in section 6;
     Results from EPA performance audit samples described in 
section 5 and the applicable RMs; and
     Summary of all corrective actions taken when CEMS was 
determined out-of-control, as described in sections 4 and 5.
    7.1.2 If the accuracy audit results show the CEMS to be out-of-
control, the CEMS operator shall report both the audit results 
showing the CEMS to be out-of-control and the results of the audit 
following corrective action showing the CEMS to be operating within 
specifications.
    8.0 Bibliography.
    1. ``A Procedure for Establishing Traceability of Gas Mixtures 
to Certain National Bureau of Standards Standard Reference 
Materials.'' Joint publication by NBS and EPA-600/7-81--10, Revised 
1989. Available from the U.S. Environmental Protection Agency. 
Quality Assurance Division (MD-77). Research Triangle Park, NC 
27711.
    2. Method 205, ``Verification of Gas Dilution Systems for Field 
Instrument Calibrations,'' 40 CFR 51, appendix M.
    9.0 Tables, Diagrams, Flowcharts and Validation Data.
    9.1 Accuracy assessment results. Complete the applicable DAR 
sections (A, B and C) for each CEMS or for each pollutant and 
diluent analyzer, as applicable. If the quarterly audit results show 
the CEMS to be out-of-control, report the results of both the 
quarterly audit and the audit following corrective action showing 
the CEMS to be operating properly.

           Figure 1--Example Format for Data Assessment Report
Period ending date
------------------------------------------------------------------------
Year
------------------------------------------------------------------------
Company name
------------------------------------------------------------------------
Plant name
------------------------------------------------------------------------
Source unit No.
------------------------------------------------------------------------
CEMS manufacturer
------------------------------------------------------------------------
Model No.
------------------------------------------------------------------------
CEMS serial No.
------------------------------------------------------------------------
CEMS type (e.g., extractive, integrated path)
------------------------------------------------------------------------
CEMS sampling location (e.g., control device outlet)
------------------------------------------------------------------------
CEMS span values as per the applicable regulation: ------------ (e.g.,
 HCl ppmv)
 

         A--Relative Accuracy Test Audit (RATA) for HCl in ppmv
1. Date of audit ------------
------------------------------------------------------------------------
2. Reference methods (RMs) used ------------ (e.g., Methods 26A, 320,
 321).
------------------------------------------------------------------------
3. Average RM value ---- (e.g., lb/MMw, ng/J, mg/dsm \3\, or percent
 volume).
------------------------------------------------------------------------
4. Average CEMS value ---- .
------------------------------------------------------------------------
5. Absolute value of mean difference [d] ----.
------------------------------------------------------------------------
6. Confidence coefficient [CC] ----.
------------------------------------------------------------------------
7. Percent relative accuracy (RA) ---- percent.
------------------------------------------------------------------------
8. * Method 26A performance audit results:
    a. Audit lot number (1) ---- (2) ----
------------------------------------------------------------------------
    b. Audit sample number (1) ---- (2) ----
------------------------------------------------------------------------
    c. Results (mg/dsm \3\) (1) ---- (2) ----
------------------------------------------------------------------------
    d. Actual value (mg/dsm \3\) (1) ---- (2)----
------------------------------------------------------------------------
    e. Relative error (1) ---- (2) ----
 
* As applicable

                                   B--Cylinder Gas Audit (CGA) for HCl in ppmv
----------------------------------------------------------------------------------------------------------------
                                           Audit point 1               Audit point 2
----------------------------------------------------------------------------------------------------------------
1. Date of audit
2. Cylinder ID number
3. Date of certification
4. Type of certification..........  ..........................  ..........................  e.g., EPA Protocol 1
                                                                                             or CRM).
5. Certified audit value..........  ..........................  ..........................  (e.g., ppm).
6. CEMS response value............  ..........................  ..........................  (e.g., ppm).

[[Page 27716]]

 
7. Accuracy.......................  ..........................  ..........................  Percent.
----------------------------------------------------------------------------------------------------------------

                                 C--Dynamic Spiking Audit (DSA) for HCL in ppmv
----------------------------------------------------------------------------------------------------------------
                                        Concentration 1            Concentration 2           Concentration 3
----------------------------------------------------------------------------------------------------------------
1. Date of audit
----------------------------------------------------------------------------------------------------------------
2. Effective Spike Addition
 (ppmv)
----------------------------------------------------------------------------------------------------------------
3. Average CEMS value
----------------------------------------------------------------------------------------------------------------
4. Spike Recovery Accuracy (%SA)
----------------------------------------------------------------------------------------------------------------
5. Average Recovery Accuracy (%SA
 average.)
----------------------------------------------------------------------------------------------------------------

[FR Doc. 2014-10824 Filed 5-13-14; 8:45 am]
BILLING CODE 6560-50-P