Two Optional Methods for Relative Accuracy Test Audits of Mercury Monitoring Systems Installed on Combustion Flue Gas Streams and Several Amendments to Related Mercury Monitoring Provisions, 51494-51531 [07-4147]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 72, Number 173 (Friday, September 7, 2007)]
[Rules and Regulations]
[Pages 51494-51531]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 07-4147]



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Part II





Environmental Protection Agency





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40 CFR Parts 60, 72 and 75



Two Optional Methods for Relative Accuracy Test Audits of Mercury 
Monitoring Systems Installed on Combustion Flue Gas Streams and Several 
Amendments to Related Mercury Monitoring Provisions; Final Rule

Federal Register / Vol. 72, No. 173 / Friday, September 7, 2007 / 
Rules and Regulations

[[Page 51494]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 60, 72 and 75

[EPA-HQ-OAR-2007-0164, FRL-8459-8]
RIN 2060-AO01


Two Optional Methods for Relative Accuracy Test Audits of Mercury 
Monitoring Systems Installed on Combustion Flue Gas Streams and Several 
Amendments to Related Mercury Monitoring Provisions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Direct final rule.

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SUMMARY: EPA is taking direct final action on two optional methods for 
relative accuracy audits of mercury monitoring systems installed on 
combustion flue gas streams and several amendments to related mercury 
monitoring provisions. This action approves two optional mercury (Hg) 
emissions test methods for potential use in conjunction with an 
existing regulatory requirement for Hg emissions monitoring, as well as 
several revisions to the mercury monitoring provisions themselves. This 
action is in regard to the testing and monitoring requirements for 
mercury specified in the Federal Register on May 18, 2005. Since that 
publication, EPA has received numerous comments concerning the 
desirability of EPA evaluating and allowing use of the measurement 
techniques addressed in the two optional methods in lieu of the methods 
identified in the cited Federal Register publication, as they can 
produce equally acceptable measures of the relative accuracy achieved 
by Hg monitoring systems. This action allows use of these two optional 
methods entirely at the discretion of the owner or operator of an 
affected emission source in place of the two currently specified 
methods. This direct final rule also amends Performance Specification 
12A by adding Methods 30A and 30B to the list of reference methods 
acceptable for measuring Hg concentration and the Hg monitoring 
provisions of May 18, 2005, to reflect technical insights since gained 
by EPA which will help to facilitate implementation including 
clarification and increased regulatory flexibility for affected 
sources.

DATES: This rule is effective on November 6, 2007 without further 
notice, unless EPA receives adverse comment by October 9, 2007. If EPA 
receives adverse comment, EPA will publish a timely withdrawal in the 
Federal Register informing the public that some or all of the 
amendments in this rule will not take effect.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2007-0164, by one of the following methods:
     www.regulations.gov. Follow the on-line instructions for 
submitting comments.
     E-mail: a-and-r-docket@epa.gov.
     Fax: (202) 566-9744.
     Mail: Two Optional Methods for Relative Accuracy Test 
Audits of Mercury Monitoring Systems Installed on Combustion Flue Gas 
Streams and Several Amendments to the Related Mercury Monitoring 
Provisions, Environmental Protection Agency, Mailcode: 2822T, 1200 
Pennsylvania Avenue, NW., Washington, DC 20460. Please include a total 
of two copies.
     Hand Delivery: EPA Docket Center, 1301 Constitution 
Avenue, NW., EPA Headquarters Library, Room 3334, EPA West Building, 
Washington, DC 20460. Such deliveries are only accepted during the 
Docket's normal hours of operation, and special arrangements should be 
made for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2007-0164. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
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 www.regulations.gov or e-mail. 
The www.regulations.gov Web site is an ``anonymous access'' system, 
which means EPA will not know your identity or contact information 
unless you provide it in the body of your comment. If you send an e-
mail comment directly to EPA without going through www.regulations.gov, 
your e-mail address will be automatically captured and included as part 
of the comment that is placed in the public docket and made available 
on the Internet. If you submit an electronic comment, EPA recommends 
that you include your name and other contact information in the body of 
your comment and with any disk or CD-ROM you submit. If EPA cannot read 
your comment due to technical difficulties and cannot contact you for 
clarification, EPA may not be able to consider your comment. Electronic 
files should avoid the use of special characters, any form of 
encryption, and be free of any defects or viruses. For additional 
information about EPA's public docket, visit the EPA Docket Center 
homepage at https://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the 
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in www.regulations.gov or in hard copy at the Two Optional Methods for 
Relative Accuracy Audits of Mercury Monitoring Systems Installed on 
Combustion Flue Gas Streams Air and Radiation Docket, EPA/DC, EPA West 
Building, EPA Headquaters Library, Room 3334, 1301 Constitution Avenue, 
NW., Washington, DC. The Public Reading Room is open from 8:30 a.m. to 
4:30 p.m., Monday through Friday, excluding legal holidays. The 
telephone number for the Public Reading Room is (202) 566-1744, and the 
telephone number for the Air and Radiation Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Either Mr. William Grimley, Office of 
Air Quality Planning and Standards, Air Quality Assessment Division, 
Measurement Technology Group (E143-02), EPA, Research Triangle Park, NC 
27711, telephone (919) 541-1065, facsimile number (919) 541-0516, e-
mail address: grimley.william@epa.gov or Ms. Robin Segall, Office of 
Air Quality Planning and Standards, Air Quality Assessment Division, 
Measurement Technology Group (E143-02), EPA, Research Triangle Park, NC 
27711, telephone (919) 541-0893, facsimile number (919) 541-0516, e-
mail address: segall.robin@epa.gov.

SUPPLEMENTARY INFORMATION: 

I. Why is EPA using a Direct Final Rule?

    EPA is publishing this rule without a prior proposed rule because 
we view this as a noncontroversial action and anticipate no adverse 
comment. The most important benefit of direct final rulemaking for this 
action is to provide: (1) Additional reference method options, and (2) 
judicious revisions to mercury monitoring provisions specified in the 
Federal Register on May 18, 2005 that, if successful, relieve affected 
facilities of uncertainty regarding final emission monitoring 
requirements and certification details as opposed to waiting through a 
potentially protracted proposal/final

[[Page 51495]]

rulemaking process. Insofar as the two methods are concerned, EPA 
believes that they contain the necessary elements to generate 
acceptable data quality without being unduly burdensome. Through 
experience gained from developing existing performance based methods 
and trading rules, EPA has learned to identify test method criteria 
significant to effective rule implementation. EPA believes each of the 
two methods adopted in this action contain adequate specific criteria 
and procedures essential to the accurate measurement of Hg emissions, 
without adversely compromising the goals of performance-based 
methodology. EPA will continue to support and advance the principles 
and practicality of these methods by adding detailed method application 
information to facilitate their use to the Web site www.epa.gov/
airmarkets/ as it becomes available. Since use of either of these 
methods is not mandatory, but optional, there should be no objection to 
their availability. Regarding the amendments to the Hg emission 
monitoring provisions of 40 CFR parts 72 and 75, these amendments 
reflect EPA's increased technical understanding since the May 18, 2005 
rulemaking. However, in the ``Proposed Rules'' section of today's 
Federal Register, we are publishing a separate document that will serve 
as the proposed rule to approve provisions, if any, of this direct 
final rule that receive relevant adverse comments on this direct final 
rule. We will not institute a second comment period on this action. Any 
parties interested in commenting must do so at this time. For further 
information about commenting on this rule, see the ADDRESSES section of 
this document.
    If EPA receives adverse comment on one or more distinct provisions 
of this rulemaking, we will publish a timely withdrawal in the Federal 
Register indicating which provisions we are withdrawing and informing 
the public that those provisions will not take effect. The provisions 
that are not withdrawn will become effective on the date set out above, 
notwithstanding adverse comment on any other provision. We would 
address all public comments in a subsequent final rule based on the 
proposed rule.

II. Does This Action Apply to Me?

    Regulated Entities. The regulated categories and entities affected 
by this direct final rule include:

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                                                  Examples of regulated
            Category                NAICS \a\            entities
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Industry.......................          221112  Fossil fuel-fired
                                                  electric utility steam
                                                  generating units.
Federal government.............      \b\ 221122  Fossil fuel-fired
                                                  electric utility steam
                                                  generating units owned
                                                  by the Federal
                                                  government.
State/local governments........      \b\ 221122  Fossil fuel-fired
                                                  electric utility steam
                                                  generating units owned
                                                  by municipalities.
Tribal governments.............          921150  Fossil fuel-fired
                                                  electric utility steam
                                                  generating units in
                                                  Indian country.
------------------------------------------------------------------------
\a\ North American Industry Classification System.
\b\ Federal, State, or local government-owned and operated
  establishments are classified according to the activity in which they
  are engaged.

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be affected by this 
direct final rule. If you have any questions regarding the 
applicability of this direct final rule to a particular entity, consult 
either the air permit authority for the entity or your EPA regional 
representative as listed in 40 CFR 63.13.

III. Where Can I Obtain a Copy of This Action?

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

IV. How Is This Document Organized?

    The information presented in this preamble is organized as 
follows:

I. Why Is EPA Using a Direct Final Rule?
II. Does This Action Apply to Me?
III. Where Can I Obtain a Copy of This Action?
IV. How Is This Document Organized?
V. Background
VI. This Action
VII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order: 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions That Significantly Affect 
Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
    K. Congressional Review Act

V. Background

    On May 18, 2005, in the preamble of the Clean Air Mercury Rule 
(CAMR) (70 FR 28608), EPA stated its intention to propose and 
promulgate an instrumental reference method as an alternative to the 
use of ASTM Method D6784-02 (the Ontario Hydro Method) to perform 
Relative Accuracy Test Audits (RATAs) of Hg continuous emission 
monitoring systems (CEMS) and sorbent trap monitoring systems used to 
monitor Hg emissions from coal-fired power plants.
    In comments on the proposed CAMR, commenters had two primary 
objections to the use of the Ontario Hydro Method as the reference test 
method for RATAs. Some expressed concern that the complexity of this 
wet chemical method could lead to results that would cause a properly 
functioning Hg CEMS to fail a RATA. Other commenters noted that, unlike 
instrumental reference methods used to audit CEMS for SO2 
and NOX that provide real-time values, test results from the 
Ontario Hydro Method can take weeks to be received from the laboratory. 
Commenters stated that this time lag can lead to implementation 
problems with regard to both missing data and emissions reporting.
    Since the CAMR was promulgated, EPA has proposed changes to 40 CFR 
part 75, which would allow the use of EPA Method 29, with enhanced 
quality-assurance procedures, as an alternative Hg reference method (71 
FR 49257; August 22, 2006). Although Method 29 is somewhat simpler than 
the Ontario Hydro Method and is more familiar to stack testers and 
State regulatory agencies, it is also a wet chemistry method and is, 
therefore, subject to the same limitations that make the Ontario Hydro 
method less than optimal for RATA testing.
    In view of these considerations, EPA believes that for RATA 
testing, an instrumental Hg reference method

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would be preferable to both the Ontario Hydro Method and to Method 29. 
An instrumental method would provide real-time data that would best 
facilitate implementation of a mercury cap and trade program. 
Therefore, this action approves a performance-based instrumental 
reference method for measuring Hg emission concentrations.
    Another commenter to the proposed CAMR recommended that the sorbent 
trap monitoring approach, now specified in 40 CFR part 75, appendix K, 
be considered for use as a reference method. Although EPA did not 
commit to establishing a sorbent trap reference method at the time of 
CAMR promulgation, stakeholder interest in this methodology has 
increased significantly. In an August 22, 2006 Federal Register notice, 
EPA solicited comment on the use of sorbent trap technology for Hg 
reference method testing, and numerous supportive comments were 
received. In view of this, we initiated a review of available 
historical test data where concurrent measurements of Hg concentration 
were made with sorbent trap systems and either the Ontario Hydro Method 
or Method 29. These data, taken together with additional supporting 
data from recent field tests that were performed after the CAMR was 
promulgated, suggest that using the sorbent trap methodology for Hg 
reference method testing is viable. The Hg sorbent trap approach is 
less onerous to use than either Ontario Hydro or Method 29, and 
although it does not measure real-time Hg concentrations, a thermal 
technique can be used to analyze the samples on the same day that they 
are collected, facilitating RATA testing in the context of a cap and 
trade program. Therefore, this action also approves a sorbent trap 
reference method for Hg, as an alternative to the Ontario Hydro Method 
and Method 29.
    This direct final rule also includes several carefully considered 
amendments to the Hg emission monitoring provisions of 40 CFR parts 72 
and 75. EPA believes these amendments will facilitate implementation of 
the CAMR by clarifying portions of that rule and by providing added 
regulatory flexibility to the affected sources.

VI. This Action

    This direct final rule allows for the earliest possible use of two 
optional reference test methods for measuring total vapor phase mercury 
emissions from stationary sources as well as several related amendments 
to the Hg monitoring provisions of the CAMR. Both an instrumental test 
method and a sorbent trap test method for measurement of total vapor 
phase mercury emissions are being added to Appendix A-8 of 40 CFR part 
60 as approved alternatives to the Ontario Hydro Method and EPA Method 
29 to perform RATAs of installed mercury monitoring systems. The two 
methods are discussed below, and the related amendments are explained 
in detail later in this section.
    The first method being added to appendix A-8 of 40 CFR part 60 
today is titled ``Method 30A--Determination of Total Vapor Phase 
Mercury Emissions from Stationary Sources (Instrumental Analyzer 
Procedure).'' In Method 30A, a sample of the effluent gas is 
continuously extracted and conveyed to an analyzer capable of measuring 
the total vapor phase Hg concentration. Elemental and oxidized mercury 
(i.e., Hg\0\ and Hg+\2\) may be measured separately or 
simultaneously but, for purposes of this method, total vapor phase Hg 
is the sum of Hg\0\ and Hg+\2\. Method 30A provides test 
program-specific verification of method performance using a dynamic 
spiking approach, coupled with other performance criteria, which 
include system calibration, interference testing, and system integrity/
drift checks. The dynamic spiking requirement, which is a gaseous 
``method of standard additions,'' is the only part of Method 30A not 
parallel to the routinely applied instrumental reference methods used 
to perform relative accuracy testing of CEMS for SO2 and 
NOX. The dynamic spiking procedure is included in Method 30A 
to characterize measurement bias for Hg, which can be highly reactive 
on a site-specific basis (i.e., for each emissions sample matrix), with 
recovery criteria set to ensure that the bias is held to a minimal 
level. All performance requirements of Method 30A must be met for the 
data to be considered valid. The availability of an instrumental 
reference method for Hg testing is consistent with the approach EPA has 
taken in the successful Acid Rain and NOX Budget emissions 
trading programs.
    Method 30A is performance based in keeping with the criteria 
established under our Notice of Intent to Implement Performance Based 
Measurement Systems for Environmental Monitoring (62 FR 52098, October 
6, 1997). Use of the performance-based measurement approach will allow 
for continued development and application of new, improved, and more 
cost-effective Hg measurement technologies while ensuring the 
collection of data of known quality.
    Based on EPA's experience in conducting test programs to evaluate 
the procedures and performance criteria included in Method 30A, EPA 
recognizes that although prototypes of all equipment needed to perform 
this method have been successfully demonstrated in the field, at 
present the equipment needed to follow all procedures required by the 
method is commercially available only on a limited basis, and is being 
further refined. One of the issues of greatest concern in the 
development of an instrumental reference method for Hg has been the 
design of the sampling probe. Most of the commercially-available probes 
suitable for Hg measurement are very heavy (over 100 lbs.) making it 
difficult to move the probe from point-to-point and port-to-port for Hg 
stratification testing and/or sample traverses. Much progress is being 
made in probe redesign. One manufacturer has recently developed a probe 
that weighs less than 40 lbs., samples at significantly lower flow 
rates, and is suitable for dynamic spiking. Additional field testing of 
this probe and others currently under development is underway, and EPA 
plans to continue to actively encourage equipment development and 
evaluation. To encourage the use of Method 30A, including further 
development of the supporting equipment, which we believe will 
eventually enable source testers to perform Hg monitoring system RATAs 
more efficiently and will become the reference method of choice for 
many testing companies and affected sources, we are deferring the 
requirement for implementation of the dynamic spiking and Hg 
stratification test procedures until January 1, 2009. EPA believes this 
deferral is reasonable because Hg monitoring data reported to EPA in 
2009 will not be used in the trading of Hg allowances, as allowance 
accounting under the CAMR does not begin until 2010. Source testers are 
encouraged to use this time to acquire the necessary equipment and 
familiarize themselves with these procedures. Also, for all emissions 
test programs and RATAs performed under CAMR prior to January 1, 2009, 
we are allowing either: (1) A 12-point traverse for sulfur dioxide 
(SO2) to be substituted for a 12-point Hg traverse, in cases 
where stratification testing is used to determine the appropriate 
number and location of the reference method sampling points, or (2) use 
of the alternate three-point traverse line (0.4, 1.2, and 2.0 meters 
from the stack wall) as specified in section 8.1.3.2 of Performance 
Specification 2 (40 CFR part 60, appendix B). We

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believe that in the short-term, these temporary deferrals will 
encourage the application of Method 30A and will help affected CAMR 
sources meet the January 1, 2009 deadline for initial certification of 
the required Hg monitoring systems. Several additional Method 30A 
development considerations are worthy of note. A preliminary draft of 
Method 30A was first available for public consideration on an EPA Web 
site (www.epa.gov/ttn/emc/) on February 28, 2006. Since that time, EPA 
and several stakeholder groups have evaluated the various technical 
aspects of the method. Based on the combined laboratory and field 
observations, EPA has been able to simplify several procedural 
requirements that we believe are essential to the method. The dynamic 
spiking requirement (for test program-specific verification of 
measurement system data quality) has been reduced to only a pretest 
requirement. The interference test has been made optional. The three-
point system calibration error test using Hg+\2\ has been 
streamlined to a system integrity check using a zero gas and a single 
upscale Hg+\2\ gas. Another change has been to relax the 
Hg\0\ calibration error specification from 2 percent to 5 percent of 
span, in recognition of the fact that this procedure is a check of the 
entire measurement system, as well as the current knowledge regarding 
the uncertainty of NIST traceable standards. EPA does plan, however, to 
reconsider this specification relaxation as more field data become 
available. A final consideration in development of Method 30A has been 
the requirement for calibration with both Hg\0\ and Hg+\2\. 
Some stakeholders have recommended that we eliminate the Hg\0\ 
calibration and rely solely on the Hg+\2\ calibration. EPA, 
however, believes this approach would not be adequate, because if only 
Hg+\2\ were used, instrument calibration response adjustment 
could compensate for an unknown amount of converter inefficiency, which 
would then result in an inaccurate total mercury measurement in 
situations where Hg\0\ is an appreciable fraction of the total stack 
gas Hg.
    The second method being added to appendix A-8 of 40 CFR part 60 
today is titled ``Method 30B--Use of Sorbent Traps to Measure Total 
Vapor Phase Mercury Emissions from Coal-Fired Combustion Sources.'' In 
Method 30B, a sample of the effluent gas is continuously drawn through 
a series of tubes containing activated carbon or another sorbent 
material. After sampling, the tubes are sealed. The Hg captured by the 
sorbent is then either: (1) Thermally desorbed and analyzed; or (2) the 
tubes are transferred to a laboratory for extraction of Hg and 
analysis. Like Method 30A, Method 30B is a performance-based method and 
contains performance specifications and procedures for hardware 
selection and calibration, sorbent spiking, and analytical recovery/
analysis which allow for development and application of new, improved, 
and more cost-effective Hg measurement technologies while still 
ensuring the collection of data of known quality. In particular, Method 
30B contains five key measurement performance tests designed to ensure: 
(1) Selection of a sorbent and analytical technique combination capable 
of quantitative collection and analysis of gaseous Hg, (2) collection 
during field testing of enough Hg on each sorbent trap to be reliably 
quantified, and (3) adequate performance of the method for each test 
program.
    In considering development of a sorbent trap-based reference 
method, EPA has reviewed historical emissions data where sorbent trap 
measurement systems were operated concurrently with either the Ontario 
Hydro Method or Method 29 (40 CFR part 60, appendix A-8). EPA has also 
conducted several field test evaluations of sorbent trap systems versus 
the Ontario Hydro Method in collaboration with the Electric Power 
Research Institute (EPRI). Based on these efforts, we have concluded 
that a sorbent trap-based technique coupled with appropriate 
performance criteria and QA procedures can provide Hg emissions data of 
quality comparable to that produced by the Ontario Hydro Method. Data 
supporting this conclusion are presented in the docket, EPA-HQ-OAR-
2007-0164.
    As we have done for Method 30A, for Method 30B emission tests and 
RATAs performed prior to January 1, 2009, we are allowing either: (1) A 
12-point traverse for sulfur dioxide (SO2) to be substituted 
for a 12-point Hg traverse for the stratification testing used to 
determine the number and location of the reference method sampling 
points, or (2) use of the alternate three-point traverse line (0.4, 
1.2, and 2.0 meters from the stack wall) as specified in section 
8.1.3.2 of Performance Specification 2 (40 CFR part 60, appendix B). We 
also intend to extend this temporary deferral of mercury stratification 
testing to application of the Ontario Hydro Method and Method 29. EPA 
believes this deferral is reasonable because Hg monitoring data 
reported to EPA in 2009 will not be used in the trading of Hg 
allowances, as allowance accounting under the CAMR does not begin until 
2010.
    This direct final rule also amends Performance Specification 12A of 
appendix B to part 60 by adding Methods 30A and 30B to the list of 
reference methods acceptable for relative accuracy testing of Hg 
emissions monitoring systems. Once this direct final rule becomes 
effective, the reference methods acceptable for Hg measurement in 
Performance Specification 12A will include Methods 29, 30A, 30B, and 
ASTM D6784-02.
    With today's action, EPA is taking the opportunity to include 
several considered revisions to the Hg emission monitoring provisions 
of 40 CFR parts 72 and 75 as described in detail below. EPA is 
including these revisions in this direct final rule because we believe 
that they will facilitate implementation of the Hg monitoring under 
CAMR.
    First, Sec.  75.81(a) is being revised to confirm that the Hg CEMS 
and sorbent trap monitoring systems required under subpart I of part 75 
are to measure the total vapor phase mass concentration of Hg in the 
flue gas, including both the elemental and oxidized forms of Hg, 
expressed in units of micrograms per standard cubic meter ([mu]g/scm). 
Although it is generally understood that total vapor phase Hg is the 
regulated pollutant under CAMR, it recently was brought to EPA's 
attention that subpart I of part 75 does not explicitly state that Hg 
monitoring systems only need to measure total vapor phase Hg. The 
amended language in Sec.  75.81(a) clarifies this.
    Second, paragraph (i) in Sec.  75.15 is being revised and a new 
paragraph (d)(2)(ix) is being added to Sec.  75.20, to codify the rules 
for using optional non-redundant (``cold'') backup Hg monitoring 
systems and like-kind replacement Hg analyzers, when the primary Hg 
monitoring system is unable to provide quality-assured data. For the 
other types of monitoring systems required by part 75, these monitoring 
options have been in place since May 1999 (see 64 FR 28597, May 26, 
1999). Today's action simply extends these provisions to Hg monitoring 
systems. Through the years, the regulated community has found these 
backup monitoring options to be beneficial, in that they minimize the 
use of missing data substitution procedures during outages of the 
primary monitoring system.
    In particular, Sec.  75.20(d)(2)(ix) specifies that a non-redundant 
backup Hg monitoring system can either be a Hg CEMS or a sorbent trap 
monitoring system. The non-redundant backup Hg

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monitoring system must be initially certified at each unit or stack 
location where it will be used, in accordance with Sec.  
75.20(d)(2)(i). For a non-redundant backup Hg CEMS, all of the initial 
certification tests specified in Sec.  75.20(c)(1) are required, except 
for the 7-day calibration error test. However, for ongoing quality 
assurance (QA), a RATA is required only once every two years (8 
calendar quarters), as specified in Sec.  75.20(d)(2)(vi). For a non-
redundant backup sorbent trap monitoring system, a RATA is required for 
initial certification, and once every two years thereafter for ongoing 
QA.
    When a certified non-redundant backup Hg CEMS or a like-kind 
replacement Hg analyzer is brought into service, a three-point 
linearity check with elemental Hg standards and a single-point system 
integrity check will be required. Alternatively, a three-level system 
integrity check may be performed instead of these two tests. When a 
certified non-redundant backup sorbent trap monitoring system is 
brought into service, only the routine sampling and QA procedures of 
Sec.  75.15 and appendix K of part 75 will be required.
    Each non-redundant backup Hg monitoring system and each like-kind 
replacement Hg analyzer will be subject to the applicable ongoing QA 
requirements, restrictions and conditions specified in Sec.  
75.20(d)(2). For certified non-redundant backup Hg CEMS and like-kind 
replacement Hg analyzers, the weekly system integrity checks described 
in section 2.6 of appendix B of 40 CFR part 75 will also be required as 
long as the system or analyzer remains in service, unless the daily 
calibration error tests of the analyzer are done using NIST-traceable 
oxidized Hg standards.
    Third, a new paragraph (k) is being added to Sec.  75.15 that: (1) 
Clarifies that, when the RATA of an appendix K sorbent trap monitoring 
system is performed, the type of sorbent material used in the appendix 
K sorbent traps must be the same as that used for daily operation of 
the appendix K monitoring system, and (2) allows the appendix K traps 
used during RATA testing to be smaller than the traps used for daily 
operation of the appendix K monitoring system. This change will be 
particularly advantageous at very low Hg concentrations as it will 
facilitate shorter RATA test run times. Parallel changes are being made 
to section 6.5.7 of appendix A of part 75 to be consistent with the 
provisions of Sec.  75.15(k). Section 6.5.7 currently requires the 
appendix K sorbent traps used for the RATA to be the same size as the 
traps used for daily operation of the appendix K monitoring system.
    Fourth, today's action revises a number of sections of part 75, 
appendix K, pertaining to the use of sorbent trap monitoring systems. 
EPA is withdrawing the requirement to use the percentage recovery of 
the elemental Hg spike in section 3 of each sorbent trap to adjust or 
``normalize'' the Hg mass collected in sections 1 and 2 of the trap. 
The requirement to spike the third section of each trap is being 
retained and data from each pair of traps must still be invalidated if 
either or both spike recovery percentages fall outside the acceptable 
limits;\1\ however, the results of the spike recoveries will no longer 
be used to adjust the Hg mass collected in the first two sections of 
the traps. EPA is making this rule change based on an analysis of 
recent spike recovery data from long-term appendix K field 
demonstrations. Although the vast majority of the spike recoveries in 
these studies have been within the currently acceptable limits of 75 to 
125 percent, the requirement to normalize based on spike recovery could 
affect data precision. For a given pair of traps, if one spike recovery 
was high (e.g., 110 percent) and the other one low (e.g., 90 percent), 
normalization of the Hg mass collected in the first two trap sections 
using third section spike recoveries could make it difficult for a pair 
of sorbent traps to meet the relative deviation (RD) specifications in 
appendix K. In the example cited, normalization of the data would cause 
the Hg concentrations measured by the traps to be adjusted by 10 
percent in opposite directions, i.e., one upward and one downward. 
Thus, two Hg concentrations that may have been in close agreement 
without normalization now might not be able to meet the RD 
specifications. In view of this, EPA has concluded that evaluating the 
spike recovery data on a pass/fail basis instead of using the percent 
recovery values to adjust the emissions data is more technically sound 
and is also consistent with the way in which the results of daily and 
quarterly QA assessments of CEMS are interpreted.
---------------------------------------------------------------------------

    \1\ On August 22, 2006, EPA proposed to amend Appendix K to 
allow the data from a pair of sorbent traps to be validated in cases 
where the third section spike recovery from only one of the traps 
meets the percent recovery specifications (see 71 FR 49275). EPA 
proposed to allow the results from the trap that meets the 
specifications to be used for reporting, provided that a single trap 
adjustment factor (STAF) of 1.222 is applied. EPA is evaluating the 
comments received on this proposal and expects to publish the final 
rule in the summer of 2007.
---------------------------------------------------------------------------

    Regarding the range of acceptable third section spike recoveries, 
EPA is not changing the 75 to 125 percent acceptance criteria. As 
previously noted, early field experience with appendix K monitoring 
systems has demonstrated that spike recoveries within this range are 
achievable. However, recent appendix K data indicate that more 
stringent acceptance criteria may be justifiable. It appears that there 
has been a marked improvement in third section spike recovery 
percentages. Recoveries in the range from 85 to 115 percent are 
consistently being achieved. If this trend continues, EPA may propose 
to tighten the spike recovery acceptance criteria in a future 
rulemaking. Toward that end, EPA will continue to collect and evaluate 
third section spike recovery data from appendix K monitoring systems in 
the months ahead.
    To effect these changes to appendix K, section 11.5 is being 
removed and reserved; section 10.4 is being revised; Equations K-6 and 
K-7 are being redesignated as Equations K-5 and K-6, respectively; and 
the definition of ``M*'' in redesignated Equation K-5 is being revised.
    EPA is also revising appendix K to allow the owner or operator to 
use other types of gas flow meters besides the conventional dry gas 
meter (DGM) to quantify sample gas volume. Since the publication of 
appendix K (see 70 FR 28695, May 18, 2005), numerous requests have been 
received from the regulated community to allow this flexibility. In 
response to these requests, EPA initiated an investigation of the 
feasibility of replacing the DGM in a sorbent trap monitoring system 
with a thermal mass flow meter. As a result of its investigation, EPA 
has concluded that a properly calibrated thermal mass flow meter can be 
at least as accurate as a DGM. The mass flow meter is also a more 
modern technology than the DGM; since it has no moving parts, it may be 
more reliable than a DGM for continuous duty.
    Having found one type of gas flow meter that can measure as 
accurately as a DGM, EPA is persuaded that there may be other 
commercially available gas flow meter technologies that are equally 
capable and may be suitable for appendix K applications. Accordingly, 
EPA has decided that a performance-based approach, rather than a 
prescriptive one, is more appropriate for appendix K gas flow meters. 
Today's action allows the use of any type of gas flow meter that is 
capable of accurately measuring gas volumes to within 2 percent.
    Section 9.2.2.1 of appendix K now requires the manufacturer of the 
gas flow meter to perform all necessary set-

[[Page 51499]]

up, testing, programming, etc. of the meter and to provide any 
necessary instructions so that for the particular field application, 
the meter will give an accurate readout of dry gas volume in units of 
standard cubic meters. Then, prior to its initial use, the flow meter 
must be calibrated at a minimum of three settings covering the expected 
range of sample flow rates for the appendix K system. The initial 
calibration may be performed either by the manufacturer or by the end 
user. The calibration of the gas flow meter must be checked quarterly 
thereafter, at an intermediate flow rate. For mass flow meters, the 
initial three-point calibration must be performed by using either a 
compressed gas mixture containing CO2, O2, and 
N2 in proportions representative of the stack gas 
composition or by using the actual stack gas. However, when the initial 
calibration is done with a compressed gas mixture, the mass flow meter 
may not be used until an additional on-site calibration check of the 
flow meter at an intermediate flow rate is performed and passed, using 
the actual stack gas.
    To calibrate the gas flow meter, the owner or operator may either 
follow the basic procedures in section 10.3 or section 16 of Method 5 
in appendix A-3 of part 60 for calibration of dry gas meters, or 
alternatively, may temporarily install a reference gas flow meter 
(RGFM) at the discharge of the appendix K monitoring system while the 
monitoring system is in operation and make concurrent measurements of 
dry stack gas volume with the RGFM and the appendix K gas flow meter. 
If the latter option is chosen, the RGFM may either be a gas flow 
metering device that has been calibrated according to section 10.3.1 or 
section 16 of Method 5 or a NIST-traceable volumetric calibration 
device with an accuracy of 1 percent. Note that this 
alternative calibration technique allows required QA checks to be 
performed with little or no disruption of the operation of the sorbent 
trap monitoring system.
    Regardless of which calibration approach is used, a calibration 
factor, Yi, must be obtained at each tested flow rate, where 
Yi is the ratio of the volume measured by the reference 
meter to the volume measured by the flow meter being calibrated. For 
the initial three-point calibration, the three Yi values 
must be averaged, and each individual Yi must be within 
 0.02 of the average value. The average value, Y, must then 
be used to correct the gas volumes measured by the gas flow meter. For 
single-level calibration checks (e.g., the quarterly checks performed 
for routine QA), the Yi value obtained at the tested flow 
rate must be compared with the current value of Y. If Yi 
differs from Y by more than 5 percent, a full three-point recalibration 
is then required to determine a new Y value.
    In this direct final action, the majority of the revised rule 
provisions pertaining to gas flow meters can be found in sections 5.1.5 
and 9.2 of appendix K. Minor revisions to sections 7.2.3 and 7.2.5, 
Figure K-1, and Table K-1 are being made to be consistent with the 
changes to sections 5.1.5 and 9.2. In several other places throughout 
part 75 and in the definition of ``Sorbent trap monitoring system'' in 
part 72, the term ``dry gas meter,'' when used in reference to a 
sorbent trap monitoring system, is being replaced with the more general 
term ``gas flow meter.'' Revisions to section 1.5.2 of appendix B of 
part 75 will require the gas flow meter calibration procedures and 
protocols for periodic recalibration of reference gas flow meters to be 
included in the QA plan for the affected unit.
    This direct final action, which approves the use of two optional 
methods (Methods 30A and 30B) for determining total vapor phase Hg 
emissions from stationary sources, is being taken in response to 
numerous public comments concerning the desirability of allowing the 
use of these types of methods to comply with the Hg emission monitoring 
requirements of the CAMR for electric utility steam generating units. 
In the May 18, 2005 final rule (70 FR 28636), we summarized the public 
comments that we received regarding the use of an instrumental method 
as an alternative to the Ontario Hydro Method specified in the proposed 
CAMR. As noted earlier in this preamble, the commenters primarily 
objected to the required use of the Ontario Hydro Method as the 
reference method for the RATAs of Hg monitoring systems and expressed 
concern about the complexities in the method and the amount of time 
that is required to perform the testing and to receive the results. 
Commenters pointed out that it could take days to complete the testing 
and weeks to receive the results from a laboratory. Commenters claimed 
that for the cap and trade program proposed under CAMR, these delays 
could lead to significant implementation problems with respect to the 
timely reporting of emissions data. Further, if a RATA should be failed 
or invalidated (e.g., if fewer than nine test runs meet the relative 
deviation criterion for the paired Ontario Hydro trains), data from the 
Hg monitoring system would be invalidated from the hour of the failed 
or invalidated test until the hour of completion of a successful RATA. 
Conservatively high substitute data values would have to be reported 
during that entire time period. In our response to those comments in 
the final CAMR rule, we stated that the alternative use of an 
instrumental method for the required RATAs of Hg monitoring systems and 
sorbent trap monitoring systems is allowed by the final rule but is 
subject to approval by the Administrator. We also stated our commitment 
to propose and promulgate a Hg instrumental reference method once 
sufficient supporting field test data become available. We further 
stated that ``A Hg instrumental reference method for RATA testing is 
vastly preferable to the Ontario Hydro Method and will greatly 
facilitate the implementation of a Hg cap-and-trade program.''
    Since promulgation of CAMR, we have continued to communicate with 
stakeholders interested in the Hg monitoring requirements of the rule, 
and we have come to more clearly understand that it is of great 
interest to the affected entities to have additional reference method 
options available for relative accuracy testing of installed Hg 
monitoring systems as soon as possible. Accordingly, at the end of 
2005, we began developing an instrumental test method for Hg and 
solicited feedback from the stakeholders on a working draft of the 
method (referred to as PRE-009 at https://www.epa.gov/ttn/emc/
prelim.html). More recently, we have been developing a viable sorbent 
trap reference method. These efforts have resulted in Methods 30A and 
30B.
    The general beneficial impacts of this direct final rule to approve 
the two optional Hg test methods and amend targeted portions of 40 CFR 
parts 72 and 75 include: Allowing affected sources to choose the use of 
an alternative to the Ontario Hydro Method without the administrative 
burden of applying for Administrator approval on a case-by-case basis; 
providing the availability of real-time RATA results (Method 30A); 
reducing the overall RATA testing times; reducing costs relative to the 
Ontario Hydro Method; and providing additional flexibility in appendix 
K sorbent trap monitoring and backup monitoring approaches. The two 
optional methods being approved by this direct final rule are 
considered to be comparable to the Ontario Hydro Method in terms of the 
quality of the results produced. Over the last year, EPA has 
collaborated with EPRI and some of its members in a number of field 
test programs that have confirmed that the instrumental reference 
method approved/established in this notice will provide data comparable 
to or better

[[Page 51500]]

than that of the ``Ontario Hydro Method.''
    Assuming we do not receive adverse comment on this direct final 
rulemaking and Methods 30A and 30B become final, we plan to post 
information relevant to Method 30A and 30B applications and equipment 
advances on EPA's Web site at https://www.epa.gov/airmarkets.

VII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

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

B. Paperwork Reduction Act

    This action does not impose an information collection burden under 
the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. 
Burden means the total time, effort, or financial resources expended by 
persons to generate, maintain, retain, or disclose or provide 
information to or for a Federal agency. This includes the time needed 
to review instructions; develop, acquire, install, and utilize 
technology and systems for the purposes of collecting, validating, and 
verifying information, processing and maintaining information, and 
disclosing and providing information; adjust the existing ways to 
comply with any previously applicable instructions and requirements; 
train personnel to be able to respond to a collection of information; 
search data sources; complete and review the collection of information; 
and transmit or otherwise disclose the information.
    An agency may not conduct or sponsor, and a person is not required 
to respond to a collection of information, unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations in 40 CFR are listed in 40 CFR part 9.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have a significant economic impact on a substantial 
number of small entities. Small entities include small businesses, 
small organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of today's rule on small 
entities, small entity is defined as: (1) A small business whose parent 
company has fewer than 100 or 1,000 employees, or fewer than 4 billion 
kilowatt-hr per year of electricity usage, depending on the size 
definition for the affected North American Industry Classification 
System code; (2) a small governmental jurisdiction that is a government 
of a city, county, town, school district or special district with a 
population of less than 50,000; and (3) a small organization that is 
any not-for-profit enterprise which is independently owned and operated 
and is not dominant in its field.
    After considering the economic impacts of today's direct final rule 
on small entities, I certify that this action will not have a 
significant economic impact on a substantial number of small entities. 
This direct final rule will not impose any requirements on small 
entities because it does not impose any additional regulatory 
requirements, but rather provides clarification and additional 
regulatory flexibilty.

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Pub. 
L. 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local, and tribal 
governments and the private sector. Under section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in expenditures to State, local, and tribal governments, in 
the aggregate, or to the private sector, of $100 million or more in any 
one year. Before promulgating an EPA rule for which a written statement 
is needed, section 205 of the UMRA generally requires EPA to identify 
and consider a reasonable number of regulatory alternatives and adopt 
the least costly, most cost-effective or least burdensome alternative 
that achieves the objectives of the rule. The provisions of section 205 
do not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective, or least burdensome alternative if the 
Administrator publishes with the final rule an explanation why that 
alternative was not adopted. Before EPA establishes any regulatory 
requirements that may significantly or uniquely affect small 
governments, including tribal governments, it must have developed under 
section 203 of the UMRA a small government agency plan. The plan must 
provide for notifying potentially affected small governments, enabling 
officials of affected small governments to have meaningful and timely 
input in the development of EPA regulatory proposals with significant 
Federal intergovernmental mandates, and informing, educating, and 
advising small governments on compliance with the regulatory 
requirements.
    EPA has determined that this direct final rule does not contain a 
Federal mandate that may result in expenditures of $100 million or more 
for State, local, and tribal governments in the aggregate, or to the 
private sector in any 1 year, nor does this rule significantly or 
uniquely impact small governments, because it contains no requirements 
that impose new obligations upon them. Thus, this direct final rule is 
not subject to the requirements of sections 202 and 205 of the UMRA.

E. Executive Order 13132: Federalism

    Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August 
10, 1999), requires EPA to develop an accountable process to ensure 
``meaningful and timely input by State and local officials in the 
development of regulatory policies that have federalism implications.'' 
``Policies that have federalism implications'' is defined in the 
Executive Order to include regulations that have ``substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government.''
    This direct final rule does not have federalism implications. It 
will not have substantial direct effects on the States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government, as specified in Executive Order 13132. The use of these 
methods is optional on the part of the regulated entities listed. Thus, 
Executive Order 13132 does not apply to this direct final rule.

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

    Executive Order 13175, entitled ``Consultation and Coordination 
with Indian Tribal Governments'' (65 FR 67249, November 9, 2000), 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by tribal officials in the development of regulatory 
policies that have tribal implications.'' This direct final rule does 
not have tribal implications, as specified in Executive Order 13175. It 
will not have substantial direct effects on tribal governments, on the

[[Page 51501]]

relationship between the Federal government and Indian tribes, or on 
the distribution of power and responsibilities between the Federal 
government and Indian tribes. Thus, Executive Order 13175 does not 
apply to this final rule.

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

    Executive Order 13045: ``Protection of Children from Environmental 
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies 
to any rule that: (1) Is determined to be ``economically significant'' 
as defined under Executive Order 12866, and (2) concerns an 
environmental health or safety risk that EPA has reason to believe may 
have a disproportionate effect on children. If the regulatory action 
meets both criteria, the Agency must evaluate the environmental health 
or safety effects of the planned rule on children, and explain why the 
planned regulation is preferable to other potentially effective and 
reasonably feasible alternatives considered by the Agency. EPA 
interprets Executive Order 13045 as applying only to those regulatory 
actions that are based on health or safety risks, such that the 
analysis required under section 5-501 of the Order has the potential to 
influence the regulation. This rule 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 That Significantly Affect Energy 
Supply, Distribution, or Use

    This rule is not subject to Executive Order 13211, ``Actions 
Concerning Regulations That Significantly Affect Energy Supply, 
Distribution, or Use'' (66 FR 28355, May 22, 2001) because it is not a 
significant regulatory action under Executive Order 12866.

I. National Technology Transfer Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law No. 104-113, section 12(d) (15 U.S.C. 
272 note) directs EPA to use voluntary consensus standards in its 
regulatory activities unless to do so would be inconsistent with 
applicable law or otherwise impractical. Voluntary consensus standards 
are technical standards (e.g., materials specifications, test methods, 
sampling procedures, and business practices) that are developed or 
adopted by voluntary consensus standards bodies. The NTTAA directs EPA 
to provide Congress, through OMB, explanations when the Agency decides 
not to use available and applicable voluntary consensus standards. This 
rulemaking involves technical standards. Consistent with the NTTAA, EPA 
in a previous related rulemaking (70 FR 28606, May 18, 2005) identified 
an acceptable VCS for measuring Hg emissions. The standard ASTM D6784-
02, Standard Test Method for Elemental, Oxidized, Particle-Bound and 
Total Mercury Gas Generated from Coal-Fired Stationary sources (Ontario 
Hydro Method) was cited in that final rule for measuring Hg emissions. 
After today's action becomes effective, the Ontario Hydro Method will 
remain an acceptable method for measuring Hg emissions.

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

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

K. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the Agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this rule and other 
required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. A major rule cannot 
take effect until 60 days after it is published in the Federal 
Register. This action is not a ``major rule'' as defined by 5 U.S.C. 
804(2). This rule will be effective on November 6, 2007.

List of Subjects

40 CFR Part 60

    Environmental protection, Administrative practice and procedures, 
Air pollution control, Continuous emission monitors, Electric 
utilities, Mercury, Test methods and procedures.

40 CFR Part 72

    Environmental protection, Administrative practice and procedures, 
Air pollution control, Continuous emission monitors, Electric 
utilities, Mercury, Test methods and procedures.

40 CFR Part 75

    Environmental protection, Administrative practice and procedures, 
Air pollution control, Continuous emission monitors, Electric 
utilities, Mercury, Test methods and procedures.

    Dated: August 17, 2007.
Stephen L. Johnson,
Administrator.

0
For the reasons set out in the preamble, title 40, chapter I, parts 60, 
72, and 75 of the Code of Federal Regulations are amended as follows:

PART 60--STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES

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

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

Appendix A-8 [Amended]

0
2. Amend Appendix A-8 by revising the heading and adding in numerical 
order Methods 30A and 30B to read as follows:

APPENDIX A-8 TO PART 60--TEST METHODS 26 THROUGH 30B

* * * * *

Method 30A--Determination of Total Vapor Phase Mercury Emissions From 
Stationary Sources (Instrumental Analyzer Procedure)

1.0 Scope and Application

What Is Method 30A?

    Method 30A is a procedure for measuring total vapor phase 
mercury (Hg) emissions from stationary sources using an instrumental 
analyzer. This method is particularly appropriate for performing 
emissions testing and for conducting relative accuracy test audits 
(RATAs) of mercury continuous emissions monitoring systems (Hg CEMS) 
and sorbent trap monitoring systems at coal-fired combustion 
sources. Quality assurance and quality control

[[Page 51502]]

requirements are included to assure that you, the tester, collect 
data of known and acceptable quality for each testing site. This 
method does not completely describe all equipment, supplies, and 
sampling procedures and analytical procedures you will need but 
refers to other test methods for some of the details. Therefore, to 
obtain reliable results, you should also have a thorough knowledge 
of these additional methods which are also found in appendices A-1 
and A-3 to this part:
    (a) Method 1--Sample and Velocity Traverses for Stationary 
Sources.
    (b) Method 4--Determination of Moisture Content in Stack Gases.
    1.1 Analytes. What does this method determine? This method is 
designed to measure the mass concentration of total vapor phase Hg 
in flue gas, which represents the sum of elemental Hg (Hg\0\) and 
oxidized forms of Hg (Hg+\2\), in mass concentration 
units of micrograms per cubic meter ([mu]g/m\3\).

------------------------------------------------------------------------
              Analyte                   CAS No.          Sensitivity
------------------------------------------------------------------------
Elemental Hg (Hg\0\)..............       7439-97-6  Typically <2% of
                                                     Calibration Span.
Oxidized Hg (Hg+\2\)..............  ..............  (Same).
------------------------------------------------------------------------

    1.2 Applicability. When is this method required? Method 30A is 
offered as a reference method for emission testing and for RATAs of 
Hg CEMS and sorbent trap monitoring systems at coal-fired boilers. 
Method 30A may also be specified for other source categories in the 
future, either by New Source Performance Standards (NSPS), National 
Emission Standards for Hazardous Air Pollutants (NESHAP), emissions 
trading programs, State Implementation Plans (SIP), or operating 
permits that require measurement of Hg concentrations in stationary 
source emissions to determine compliance with an applicable emission 
standard or limit, or to conduct RATAs of Hg CEMS and sorbent trap 
monitoring systems.
    1.3 Data Quality Objectives (DQO). How good must my collected 
data be? Method 30A has been designed to provide data of high and 
known quality for Hg emission testing and for relative accuracy 
testing of Hg monitoring systems including Hg CEMS and sorbent trap 
monitoring systems. In these and other applications, the principle 
objective is to ensure the accuracy of the data at the actual 
emission levels encountered. To meet this objective, calibration 
standards prepared according to an EPA traceability protocol must be 
used and measurement system performance tests are required.

2.0 Summary of Method

    In this method, a sample of the effluent gas is continuously 
extracted and conveyed to an analyzer capable of measuring the total 
vapor phase Hg concentration. Elemental and oxidized mercury (i.e., 
Hg\0\ and Hg+\2\) may be measured separately or 
simultaneously but, for purposes of this method, total vapor phase 
Hg is the sum of Hg\0\ and Hg+\2\. You must meet the 
performance requirements of this method (i.e., system calibration, 
interference testing, dynamic spiking, and