<IP_ADDRESS>.2 of this method.  of a Hg
                                                                                stratification
                                                                                test. If the test
                                                                                location is
                                                                                unstratified or
                                                                                minimally
                                                                                stratified for SO2,
                                                                                it can be
                                                                                considered
                                                                                unstratified or
                                                                                minimally
                                                                                stratified for Hg
                                                                                also.

                     ....................  ....................  If the Hg concentration    On and after 1/1/09,
                                                                  is > 10% of the mean at    only Hg
                                                                  any point, then, if the    stratification
                                                                  alternative                tests are
                                                                  specification is not met   acceptable for the
                                                                  or if the stack diameter   purposes of this
                                                                  is < = 2.4 m (7.8 ft):      method.
                                                                  Perform sampling
                                                                  at 12 Method 1 points;
                                                                  or.
                                                                  Sample at 3
                                                                  points located at 16.7,
                                                                  50.0 and 83.3% of the
                                                                  measurement line that
                                                                  exhibited the highest
                                                                  average Hg concentration
                                                                  during stratification
                                                                  test; or.
                                                                  Sample at 6
                                                                  Method 1 points along
                                                                  the line that exhibited
                                                                  the highest average Hg
                                                                  concentration (Part 75
                                                                  RATAs, only).
M..................  Data Recording......  Frequency...........  Once per cycle...........  During run.
S..................  Data Parameters.....  Sample concentration  All analyzer readings      Each run.
                                            and calibration       during each run within
                                            span.                 calibration span.
M..................  Data Parameters.....  Sample concentration  All analyzer readings      Each spike
                                            and calibration       during dynamic spiking     injection.
                                            span.                 tests within 120% of
                                                                  calibration span.
M..................  Data Parameters.....  Sample concentration  Average Hg concentration   Each run.
                                            and calibration       for the run < =
                                            span.                 calibration span.
----------------------------------------------------------------------------------------------------------------
\1\ M = Mandatory; S = Suggested; A = Alternative.
\2\ These may either be the unadjusted Hg concentrations or concentrations normalized to account for temporal
  variations.

10.0 Calibration and Standardization

What measurement system calibrations are required?

    Your analyzer must be calibrated with Hg[deg] standards. The
initial 3-point system calibration error test described in Section
8.2.4 is required before you start the test. Also, prior to and
following test runs, the two-point system integrity checks described
in Sections 8.2.5 and 8.2.8 are required. On and after January 1,
2009, the pre-test dynamic spiking procedure described in section
8.2.7 is also required to verify that the accuracy of the
measurement system is suitable and not adversely affected by the
flue gas matrix.

11.0 Analytical Procedures

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

12.0 Calculations and Data Analysis

    You must follow the procedures for calculations and data
analysis listed in this section.

    12.1 Nomenclature. The terms used in the equations are defined
as follows:
Bws = Moisture content of sample gas as measured by
Method 4 in Appendix A-3 to this part, percent/100.
Cavg = Average unadjusted Hg concentration for the test
run, as indicated by the data recorder [mu]g/m\3\.
Cbaseline = Average Hg concentration measured before and
after dynamic spiking injections, [mu]g/m\3\.
Cd = Hg concentration, dry basis, [mu]g/m\3\.
Cdif = Absolute value of the difference between the
measured Hg concentrations of the reference HgCl2
calibration gas, with and without the individual or combined
interference gases, [mu]g/m\3\.
Cdif avg = Average of the 3 absolute values of the
difference between the measured Hg concentrations of the reference
HgCl2 calibration gas, with and without the individual or
combined interference gases, [mu]g/m\3\.
Cgas = Average Hg concentration in the effluent gas for
the test run, adjusted for system calibration error, [mu]g/m\3\.
Cint = Measured Hg concentration of the reference
HgCl2 calibration gas plus the individual or combined
interference gases, [mu]g/m\3\.
Cm = Average of pre- and post-run system integrity check
responses for the upscale (i.e., mid- or high-level) calibration
gas, [mu]g/m\3\.
Cma = Actual concentration of the upscale (i.e., mid- or
high-level) calibration gas used for the system integrity checks,
[mu]g/m\3\.
C0 = Average of pre- and post-run system integrity check
responses from the zero gas, [mu]g/m\3\.
Cnative = Vapor phase Hg concentration in the source
effluent, [mu]g/m\3\.
Cref = Measured Hg concentration of the reference
HgCl2 calibration gas alone, in the interference test,
[mu]g/m\3\.
Cs = Measured concentration of a calibration gas (zero-,
low-, mid-, or high-level), when introduced in system calibration
mode, [mu]g/m\3\.
Cspike = Actual Hg concentration of the spike gas, [mu]g/
m\3\.
C*spike = Hg concentration of the spike gas required to
achieve a certain target value for the spiked sample Hg
concentration, [mu]g/m\3\.
Css = Measured Hg concentration of the spiked sample at
the target level, [mu]g/m\3\.
C*ss = Expected Hg concentration of the spiked sample at
the target level, [mu]g/m\3\.
Ctarget = Target Hg concentration of the spiked sample,
[mu]g/m\3\.
CTnative = Measured tracer gas concentration present in
native effluent gas, ppm.
CTdir = Tracer gas concentration injected with spike gas,
ppm.
CTv = Diluted tracer gas concentration measured in a
spiked sample, ppm.
Cv = Certified Hg[deg] or HgCl2 concentration
of a calibration gas (zero, low, mid, or high), [mu]g/m\3\.
Cw = Hg concentration measured under moist sample
conditions, wet basis, [mu]g/m\3\.
CS = Calibration span, [mu]g/m\3\.
D = Zero or upscale drift, percent of calibration span.
DF = Dilution factor of the spike gas, dimensionless.
I = Interference response, percent of calibration span.
Qprobe = Total flow rate of the stack gas sample plus the
spike gas, liters/min.
Qspike = Flow rate of the spike gas, liters/min.
Ri = Individual injection spike recovery, %;.
R= Mean value of spike recoveries at a particular target level, %;.
RSD = Relative standard deviation, %;.
SCE = System calibration error, percent of calibration span.
SCEi = Pre-run system calibration error during the two-
point system integrity check, percent of calibration span.
SCEf = Post-run system calibration error during the two-
point system integrity check, percent of calibration span.

    12.2 System Calibration Error. Use Equation 30A-1 to calculate
the system calibration error. Equation 30A-1 applies to: 3-point
system calibration error tests performed with Hg[deg] standards; and
pre- and post-run two-point system integrity checks performed with
HgCl2.
[GRAPHIC] [TIFF OMITTED] TR07SE07.005

    12.3 Drift Assessment. Use Equation 30A-2 to separately
calculate the zero and upscale drift for each test run.
[GRAPHIC] [TIFF OMITTED] TR07SE07.006

    12.3 Effluent Hg Concentration. For each test run, calculate
Cavg, the arithmetic average of all valid Hg
concentration values recorded during the run. Then, adjust the value
of Cavg

for system calibration error, using Equation 30A-3.
[GRAPHIC] [TIFF OMITTED] TR07SE07.007

    12.4 Moisture Correction. Use Equation 30A-4a if your
measurements need to be corrected to a dry basis.
[GRAPHIC] [TIFF OMITTED] TR07SE07.008

    Use Equation 30A-4b if your measurements need to be corrected to
a wet basis.
[GRAPHIC] [TIFF OMITTED] TR07SE07.009

    12.5 Dynamic Spike Gas Concentrations. Use Equation 30A-5 to
determine the spike gas concentration needed to produce a spiked
sample with a certain ``target'' Hg concentration.
[GRAPHIC] [TIFF OMITTED] TR07SE07.010

    12.6 Spiked Sample Concentration. Use Equation 30A-6 to
determine the expected or theoretical Hg concentration of a spiked
sample.
[GRAPHIC] [TIFF OMITTED] TR07SE07.011

    12.7 Spike Recovery. Use Equation 30A-7 to calculate the
percentage recovery of each spike.
[GRAPHIC] [TIFF OMITTED] TR07SE07.012

    12.8 Relative Standard Deviation. Use Equation 30A-8 to
calculate the relative standard deviation of the individual
percentage spike recovery values from the mean.
[GRAPHIC] [TIFF OMITTED] TR07SE07.013

    12.9 Spike Dilution Factor. Use Equation 30A-9 to calculate the
spike dilution factor, using either direct flow measurements or
tracer gas measurements.
[GRAPHIC] [TIFF OMITTED] TR07SE07.014

    12.10 Native Concentration. For spiking procedures that inject
blank or carrier gases (at the spiking flow rate, Qspike)
between spikes, use Equation 30A-10 to calculate the native
concentration.
[GRAPHIC] [TIFF OMITTED] TR07SE07.015

    For spiking procedures that halt all injections between spikes,
the native concentration equals the average baseline concentration
(see Equation 30A-11).
[GRAPHIC] [TIFF OMITTED] TR07SE07.016

    12.11 Overall Interference Response. Use equation 30A-12 to
calculate the overall interference response.
[GRAPHIC] [TIFF OMITTED] TR07SE07.017

    Where, for each interference gas (or mixture):
    [GRAPHIC] [TIFF OMITTED] TR07SE07.018

    [GRAPHIC] [TIFF OMITTED] TR07SE07.019

13.0 Method Performance

    13.1 System Calibration Error Test. This specification applies
to the 3-point system calibration error tests using Hg0.
At each calibration gas level tested (low-, mid-, or high-level),
the calibration error must be within 5.0 percent of the
calibration span. Alternatively, the results are acceptable if
[bond] Cs - Cv [bond] <=0.5 [mu]g/
m3.
    13.2 System Integrity Checks. This specification applies to all
pre- and post-run 2-point system integrity checks using
HgCl2 and zero gas. At each calibration gas level tested
(zero and mid- or high-level), the error must be within < plus-
minus>5.0 percent of the calibration span. Alternatively, the
results are acceptable if [bond] Cs - Cv
[bond] <=0.5 [mu]g/m3.
    13.3 Drift. For each run, the low-level and upscale drift must
be less than or equal to 3.0 percent of the calibration span. The
drift is also acceptable if the pre- and post-run system integrity
check responses do not differ by more than 0.3 [mu]g/m3
(i.e., [bond] Cs post-run - Cs pre-run [bond]
<=0.3 [mu]g/m3).
    13.4 Interference Test. Summarize the results following the
format contained in Table 30A-4. For each interference gas (or
mixture), calculate the mean difference between the measurement
system responses with and without the interference test gas(es). The
overall interference response for the analyzer that was used for the
test (calculated according to Equation 30A-12), must not be greater
than 3.0 percent of the calibration span used for the test (see
Section 8.6). The results of the interference test are also
acceptable if the sum of the absolute average differences for all
interference gases (i.e., [Sigma] Cdif avg) does not
exceed 0.3 [mu]g/m3.
    13.5 Dynamic Spiking Test. For the pre-test dynamic spiking, the
mean value of the percentage spike recovery must be 100 < plus-
minus>10 percent. In addition, the relative standard deviation (RSD)
of the individual percentage spike recovery values from the mean
must be < =5.0 percent. Alternatively, if the mean percentage
recovery is not met, the results are acceptable if the absolute
difference between the theoretical spiked sample concentration (see
Section 12.6) and the actual average value of the spiked sample
concentration is <=0.5 [mu]g/m3.

14.0 Pollution Prevention [Reserved]

15.0 Waste Management [Reserved]

16.0 References

    1. EPA Traceability Protocol for Qualification and Certification
of Elemental Mercury Gas Generators, expected publication date
December 2008, see http://www.epa.gov/ttn/emc.

    2. EPA Traceability Protocol for Qualification and Certification
of Oxidized Mercury Gas Generators, expected publication date
December 2008, see http://www.epa.gov/ttn/emc.

    3. EPA Traceability Protocol for Assay and Certification of
Gaseous Calibration Standards, expected revision publication date
December 2008, see http://www.epa.gov/ttn/emc.

17.0 Figures and Tables

BILLING CODE 6560-50-C

[GRAPHIC] [TIFF OMITTED] TR07SE07.020

[GRAPHIC] [TIFF OMITTED] TR07SE07.021

[GRAPHIC] [TIFF OMITTED] TR07SE07.022

[GRAPHIC] [TIFF OMITTED] TR07SE07.023

           Table 30A-3.--Interference Check Gas Concentrations
------------------------------------------------------------------------
                                     Concentration,  tentative--(balance
   Potential interferent gas \1\                     N2)
------------------------------------------------------------------------
CO2...............................  15%  1% CO2
CO................................  100  20 ppm
HCl \2\...........................  100  20 ppm
NO \2\............................  250  50 ppm
SO2...............................  200  20 ppm
O2................................  3%  1% O2
H2O...............................  10%  1% H2O
Nitrogen..........................  Balance
Other ............................
------------------------------------------------------------------------
\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\ HCl and NO must be tested as a mixture.

[GRAPHIC] [TIFF OMITTED] TR07SE07.024

[GRAPHIC] [TIFF OMITTED] TR07SE07.025

Method 30B--Determination of Total Vapor Phase Mercury Emissions From
Coal-Fired Combustion Sources Using Carbon Sorbent Traps

1.0 Scope and Application

What is Method 30B?

    Method 30B is a procedure for measuring total vapor phase
mercury (Hg) emissions from coal-fired combustion sources using
sorbent trap sampling and an extractive or thermal analytical
technique. This method is only intended for use only under
relatively low particulate conditions (e.g., sampling after all
pollution control devices). Quality assurance and quality control
requirements are included to assure that you, the tester, collect
data of known and acceptable quality for each testing program. This
method does not completely describe all equipment, supplies, and
sampling and analytical procedures you will need, but instead 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 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.
    (c) Method 5--Determination of Particulate Matter Emissions from
Stationary Sources
    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, including elemental Hg (Hg\0\) and oxidized forms of Hg
(Hg+\2\), in micrograms per dry standard cubic meter
([mu]g/dscm).

------------------------------------------------------------------------
                                                   Analytical range and
              Analyte                  CAS No.          sensitivity
------------------------------------------------------------------------
Elemental Hg (Hg \0\ ).............    7439-97-6  Typically 0.1 [mu]g/
                                                   dscm to >50 [mu]g/
                                                   dscm.
Oxidized Hg (Hg+\2\)...............  ...........  (Same)
------------------------------------------------------------------------

    1.2 Applicability. When is this method required? Method 30B is a
reference method for relative accuracy test audits (RATAs) of vapor
phase Hg CEMS and sorbent trap monitoring systems installed at coal-
fired boilers and is also appropriate for Hg emissions testing at
such boilers. It is intended for use only under relatively low
particulate conditions (i.e., sampling after all pollution control
devices); in cases where significant amounts of particle-bound Hg
may be present, an isokinetic sampling method for Hg should be used.
Method 30B may also be specified by New Source Performance Standards
(NSPS), National Emission Standards for Hazardous Air Pollutants
(NESHAP), emissions trading programs, State Implementation Plans
(SIPs), and operating permits that require measurement of Hg
concentrations in stationary source emissions, either 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 30B has been designed to provide data of high and
known quality for Hg emissions testing and for RATA testing of Hg
monitoring systems, including CEMS and sorbent trap monitors. In
these and other applications, the principal objective is to ensure
the accuracy of the data at the actual emissions levels and in the
actual emissions matrix encountered. To meet this objective, NIST-
traceable calibration standards must be used and method performance
tests are required.

2.0 Summary of Method

    Known volumes of flue gas are extracted from a stack or duct
through paired, in-stack sorbent media traps at an appropriate flow
rate. Collection of mercury on the sorbent media in the stack
mitigates potential loss of mercury during transport through a
probe/sample line. For each test run, paired train sampling is
required to determine measurement precision and verify acceptability
of the measured emissions data. A field recovery test which assesses
recovery of an elemental Hg spike to determine measurement bias is
also used to verify data acceptability. The sorbent traps are
recovered from the sampling system, prepared for analysis as needed,
and analyzed by any suitable determinative technique that can meet
the performance criteria.

3.0 Definitions

    3.1 Analytical System is the combined equipment and apparatus
used to perform sample analyses. This includes any associated sample
preparation apparatus e.g., digestion equipment, spiking systems,
reduction devices, etc., as well as analytical instrumentation such
as UV AA and UV AF cold vapor analyzers.
    3.2 Calibration Standards are the Hg containing solutions
prepared from NIST traceable standards and are used to directly
calibrate analytical systems.
    3.3 Independent Calibration Standard is a NIST traceable
standard obtained from a source or supplier independent of that for
the calibration standards and is used to confirm the integrity of
the calibration standards used.
    3.4 Method Detection Limit (MDL) is the lowest mass of Hg
greater than zero that can be estimated and reported by your
candidate analytical technique. The MDL is statistically derived
from replicate low level measurements near your analytical
instrument's detection level.
    3.5 NIST means the National Institute of Standards and
Technology, located in Gaithersburg, Maryland.
    3.6 Run means a series of gas samples taken successively from
the stack or duct. A test normally consists of a specific number of
runs.
    3.7 Sorbent Trap means a cartridge or sleeve containing a
sorbent media (typically activated carbon treated with iodine or
some other halogen) with multiple sections separated by an inert
material such as glass wool. These sorbent traps are optimized for
the quantitative capture of elemental and oxidized forms of Hg and
can be analyzed by multiple techniques.
    3.8 Test refers to the series of runs required by the applicable
regulation.
    3.9 Thermal Analysis means an analytical technique where the
contents of the sorbent traps are analyzed using a thermal technique
(desorption or combustion) to release the captured Hg in a
detectable form for quantification.
    3.10 Wet Analysis means an analytical technique where the
contents of the sorbent tube are first leached or digested to
quantitatively transfer the captured Hg to liquid solution for
subsequent analysis.

4.0 Interferences

    Interferences may result from the sorbent trap material used as
well as from the measurement environment itself. The iodine present
on some sorbent traps may impart a negative measurement bias. High
levels of sulfur trioxide (SO3) are also suspected to
compromise the performance of sorbent trap Hg capture. These, and
other, potential interferences are assessed by performing the
analytical matrix interference, Hg\0\ and HgCl2
analytical bias and field recovery tests.

5.0 Safety

    What safety measures should I consider when using this method?
This method may require you to work with hazardous materials and in
hazardous conditions. You are encouraged to establish safety
procedures before using the method. Among other precautions, you
should become familiar with the safety recommendations in the gas
analyzer user's manual. Occupational Safety and Health
Administration (OSHA) regulations concerning use of compressed gas
cylinders and noxious gases may apply.
    5.1 Site Hazards. Prior to applying these procedures/
specifications in the field, the potential hazards at the test site
should be considered; advance coordination with the site is critical
to understand the conditions and applicable safety policies. At a
minimum, portions of the sampling system will be hot, requiring
appropriate gloves, long sleeves, and caution in handling this
equipment.
    5.2 Laboratory Safety. Policies should be in place to minimize
risk of chemical exposure and to properly handle waste disposal in
the laboratory. Personnel shall wear appropriate laboratory attire
according to a Chemical Hygiene Plan established by the laboratory.
    5.3 Reagent Toxicity/Carcinogenicity. The toxicity and
carcinogenicity of any reagents used must be considered. Depending
upon the sampling and analytical technologies selected, this
measurement may involve hazardous materials, operations, and
equipment and this method does not address all of the safety
problems associated with implementing this approach. It is the
responsibility of the user to establish appropriate safety and
health practices and determine the applicable regulatory limitations
prior to performance. Any chemical should be regarded as a potential
health hazard and exposure to these compounds should be minimized.
Chemists should refer to the Material Safety Data Sheet (MSDS) for
each chemical used.
    5.4 Waste Disposal. Any waste generated by this procedure must
be disposed of

according to a hazardous materials management plan that details and
tracks various waste streams and disposal procedures.

6.0 Equipment and Supplies

    The following list is presented as an example of key equipment
and supplies likely required to measure vapor-phase Hg using a
sorbent trap sampling system. It is recognized that additional
equipment and supplies may be needed. Collection of paired samples
is required.
    6.1 Sorbent Trap Sampling System. A typical sorbent trap
sampling system is shown in Figure 30B-1 in Section 17.0. The
sorbent trap sampling system shall include the following components:
    6.1.1 Sorbent Traps. The sorbent media used to collect Hg must
be configured in a trap with at least two distinct segments or
sections, connected in series, that are amenable to separate
analyses. Section 1 is designated for primary capture of gaseous Hg.
Section 2 is designated as a backup section for determination of
vapor phase Hg breakthrough. Each sorbent trap must be inscribed or
otherwise permanently marked with a unique identification number,
for tracking purposes. The sorbent media may be any collection
material (e.g., carbon, chemically-treated filter, etc.) capable of
quantitatively capturing and recovering for subsequent analysis, all
gaseous forms of Hg in the emissions from the intended application.
Selection of the sorbent media shall be based on the material's
ability to achieve the performance criteria contained in this method
as well as the sorbent's vapor phase Hg capture efficiency for the
emissions matrix and the expected sampling duration at the test
site. The sorbent media must be obtained from a source that can
demonstrate their quality assurance and quality control (see Section
7.2). The paired sorbent traps are supported on a probe (or probes)
and inserted directly into the flue gas stream.
    6.1.2 Sampling Probe Assembly. Each probe assembly shall have a
leak-free attachment to the sorbent trap(s). Each sorbent trap must
be mounted at the entrance of or within the probe such that the gas
sampled enters the trap directly. Each probe/sorbent trap assembly
must be heated to a temperature sufficient to prevent liquid
condensation in the sorbent trap(s). Auxiliary heating is required
only where the stack temperature is too low to prevent condensation.
Use a calibrated thermocouple to monitor the stack temperature. A
single probe capable of operating the paired sorbent traps may be
used. Alternatively, individual probe/sorbent trap assemblies may be
used, provided that the individual sorbent traps are co-located to
ensure representative Hg monitoring.
    6.1.3 Moisture Removal Device. A moisture removal device or
system shall be used to remove water vapor from the gas stream prior
to entering dry gas flow metering devices.
    6.1.4 Vacuum Pump. Use a leak-tight, vacuum pump capable of
operating within the system's flow range.
    6.1.5 Gas Flow Meter. A gas flow meter (such as a dry gas meter,
thermal mass flow meter, or other suitable measurement device) shall
be used to determine the total sample volume on a dry basis, in
units of standard cubic meters. The meter must be sufficiently
accurate to measure the total sample volume to within 2 percent and
must be calibrated at selected flow rates across the range of sample
flow rates at which the sampling train will be operated. The gas
flow meter shall be equipped with any necessary auxiliary
measurement devices (e.g., temperature sensors, pressure measurement
devices) needed to correct the sample volume to standard conditions.
    6.1.6 Sample Flow Rate Meter and Controller. Use a flow rate
indicator and controller for maintaining necessary sampling flow
rates.
    6.1.7 Temperature Sensor. Same as Section <IP_ADDRESS> of Method 5 in
Appendix A-3 to this part.
    6.1.8 Barometer. Same as Section 6.1.2 of Method 5 in Appendix
A-3 to this part.
    6.1.9 Data Logger (optional). Device for recording associated
and necessary ancillary information (e.g., temperatures, pressures,
flow, time, etc.).
    6.2 Gaseous Hg\0\ Sorbent Trap Spiking System. A known mass of
gaseous Hg\0\ must be either present on or spiked onto the first
section of sorbent traps in order to perform the Hg\0\ and
HgCl2 analytical bias test and the field recovery study.
Any approach capable of quantitatively delivering known masses of
Hg\0\ onto sorbent traps is acceptable. Several spiking technologies
or devices are available to meet this objective. Their practicality
is a function of Hg mass spike levels. For low levels, NIST-
certified or NIST-traceable gas generators or tanks may be suitable.
An alternative system, capable of delivering almost any mass
required, makes use of NIST-certified or NIST-traceable Hg salt
solutions (e.g., HgCl2, Hg(NO3)2).
With this system, an aliquot of known volume and concentration is
added to a reaction vessel containing a reducing agent (e.g.,
stannous chloride); the Hg salt solution is reduced to Hg\0\ and
purged onto the sorbent trap using an impinger sparging system. When
available, information on example spiking systems will be posted at
http://www.epa.gov/ttn/emc.

    6.3 Sample Analysis Equipment. Any analytical system capable of
quantitatively recovering and quantifying total Hg from the sorbent
media selected is acceptable provided that the analysis can meet the
performance criteria described in this method. Example recovery
techniques include acid leaching, digestion, and thermal desorption/
direct combustion. Example analytical techniques include, but are
not limited to, ultraviolet atomic fluorescence (UV AF), ultraviolet
atomic absorption (UV AA) with and without gold trapping, and X-ray
fluorescence (XRF) analysis.
    6.3 Moisture Measurement System. If correction of the measured
Hg emissions for moisture is required (see Section <IP_ADDRESS>), either
Method 4 in Appendix A-3 to 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 Reagents and Standards. Only NIST-certified or NIST-
traceable calibration standards, standard reference materials, and
reagents shall be used for the tests and procedures required by this
method.
    7.2 Sorbent Trap Media. The sorbent trap media shall be prepared
such that the material used for testing is of known and acceptable
quality. Sorbent supplier quality assurance/quality control measures
to ensure appropriate and consistent performance such as sorptive
capacity, uniformity of preparation treatments, and background
levels shall be considered.

8.0 Sample Collection and Handling

    This section presents the sample collection and handling
procedures along with the pretest and on-site performance tests
required by this method. Since you may choose different options to
comply with certain performance criteria, each test report must
identify the specific options selected and document the results with
respect to the performance criteria of this method.
    8.1 Sample Point Selection. What sampling site and sampling
points do I select? Same as Section 8.1 of Method 30A of this
appendix.
    8.2 Measurement System Performance Tests. What performance
criteria must my measurement system meet? The following laboratory
and field procedures and associated criteria of this section are
designed to ensure (1) selection of a sorbent and analytical
technique combination capable of quantitative collection and
analysis of gaseous Hg, (2) collection of an adequate amount of Hg
on each sorbent trap during field tests, and (3) adequate
performance of the method for each test program: The primary
objectives of these performance tests are to characterize and verify
the performance of your intended analytical system and associated
sampling and analytical procedures, and to define the minimum amount
of Hg (as the sample collection target) that can be quantified
reliably.
    (a) Analytical Matrix Interference Test;
    (b) Determination of Minimum Sample Mass;
    (c) Hg\0\ and HgCl2 Analytical Bias Test;
    (d) Determination of Nominal Sample Volume;
    (e) Field Recovery Test.
    8.2.1 Analytical Matrix Interference Test and Minimum Sample
Dilution.
    (a) The analytical matrix interference test is a laboratory
procedure. It is required only if you elect to use a liquid
digestion analytical approach and needs to be performed only once
for each sorbent material used. The purpose of the test is to verify
the presence or absence of known and potential analytical matrix
interferences, including the potential negative bias associated with
iodine common to many sorbent trap materials. The analytical matrix
interference test determines the minimum dilution (if any) necessary
to mitigate matrix effects on the sample digestate solutions.
    (b) The result of the analytical matrix interference test, i.e.,
the minimum sample dilution required (if any) for all sample

analyses, is used to establish the minimum sample mass needed for
the Hg\0\ and HgCl2 analytical bias test and to determine
the nominal sample volume for a test run. The analytical matrix
interference test is sorbent material-specific and shall be
performed for each sorbent material you intend to use for field
sampling and analysis. The test shall be performed using a mass of
sorbent material comparable to the sorbent mass typically used in
the first section of the trap for sampling. Similar sorbent
materials from different sources of supply are considered to be
different materials and must be tested individually. You must
conduct the analytical matrix interference test for each sorbent
material prior to the analysis of field samples.
    <IP_ADDRESS> Analytical Matrix Interference Test Procedures. Digest
and prepare for analysis a representative mass of sorbent material
(unsampled) according to your intended laboratory techniques for
field samples. Analyze the digestate according to your intended
analytical conditions at the least diluted level you intend to use
for sample analysis (e.g., undiluted, 1 in 10 dilution, etc.).
Determine the Hg concentration of the undiluted digestate solution.
Prepare a series of solutions with a fixed final volume containing
graduated aliquots of the sample digestate and, a fixed aliquot of a
calibration standard (with the balance being Hg-free reagent or
H20) to establish solutions of varied digestate dilution
ratio (e.g., 1:2, 1:5, 1:10, 1:100, etc.--see example in Section
<IP_ADDRESS>, below). One of these solutions should contain only the
aliquot of the calibration standard in Hg-free reagent or
H2O. This will result in a series of solutions where the
amount of Hg is held relatively constant and only the volume of
digestate diluted is varied. Analyze each of these solutions
following intended sample analytical procedures and conditions,
determining the concentration for each solution.
    <IP_ADDRESS> Analytical Matrix Interference Test Acceptance Criteria.
Compare the measured concentration of each solution containing
digestate to the measured concentration of the digestate-free
solution. The lowest dilution ratio of any solution having a Hg
concentration within 5 percent of the digestate-free
solution is the minimum dilution ratio required for analysis of all
samples. If you desire to measure the digestate without dilution,
the  5 percent criterion must be met at a dilution ratio
of at least 9:10 (i.e., >=90% digestate).
    <IP_ADDRESS> Example Analytical Matrix Interference Test. An example
analytical matrix interference test is presented below. Additional
information on the conduct of the analytical matrix interference
test will be posted at http://www.epa.gov/ttn/emc. Determine the

most sensitive working range for the analyzer to be used. This will
be a narrow range of concentrations. Digest and prepare for analysis
a representative mass of sorbent material (unsampled) according to
your intended laboratory techniques for sample preparation and
analysis. Prepare a calibration curve for the most sensitive
analytical region, e.g., 0.0, 0.5, 1.0, 3.0, 5.0, 10 ppb. Using the
highest calibration standard, e.g., 10.0 ppb, prepare a series of
solutions by adding successively smaller increments of the digestate
to a fixed volume of the calibration standard and bringing each
solution to a final fixed volume with mercury-free deionized water
(diH2O). To 2.0 ml of the calibration standard add 18.0,
10.0, 4.0, 2.0, 1.0, 0.2, and 0.0 ml of the digestate. Bring the
final volume of each solution to a total volume of 20 ml by adding
0.0, 8.0, 14.0, 16.0, 17.0, 17.8, and 18.0 ml of diH2O.
This will yield solutions with dilution ratios of 9:10, 1:2, 1:5,
1:10, 1:20, 1:100, and 0:10, respectively. Determine the Hg
concentration of each solution. The dilution ratio of any solution
having a concentration that is within 5 percent of the
concentration of the solution containing 0.0 ml of digestate is an
acceptable dilution ratio for analyzing field samples. If more than
one solution meets this criterion, the one with the lowest dilution
ratio is the minimum dilution required for analysis of field
samples. If the 9:10 dilution meets this criterion, then no sample
dilution is required.
    8.2.2 Determination of Minimum Sample Mass. The minimum mass of
Hg that must be collected per sample must be determined. This
information is necessary in order to effectively perform the Hg\0\
and HgCl2 Analytical Bias Test, to estimate target sample
volumes/sample times for test runs, and to ensure the quality of the
measurements. The determination of minimum sample mass is a direct
function of analytical technique, measurement sensitivity,
dilutions, etc. This determination is required for all analytical
techniques. Based on the analytical approach you employ, you should
determine the most sensitive calibration range. Based on a
calibration point within that range, you must consider all sample
treatments (e.g., dilutions) to determine the mass of sample that
needs to be collected to ensure that all sample analyses fall within
your calibration curve.
    <IP_ADDRESS> Determination of Minimum Calibration Concentration or
Mass. Based on your instrument's sensitivity and linearity,
determine the calibration concentrations or masses that make up a
representative low level calibration range. Verify that you are able
to meet the multipoint calibration performance criteria in section
11.0 of this method. Select a calibration concentration or mass that
is no less than 2 times the lowest concentration or mass in your
calibration curve. The lowest point in your calibration curve must
be at least 5, and preferably 10, times the Method Detection Limit
(MDL), which is the minimum amount of the analyte that can be
detected and reported. The MDL must be determined at least once for
the analytical system using an MDL study such as that found in
section 17.0 of the proposed amendments to EPA Method 301 (69 FR
76642, 12/22/2004).
    Note to Section <IP_ADDRESS>: While it might be desirable to base the
minimum calibration concentration or mass on the lowest point in the
calibration curve, selecting a higher concentration or mass is
necessary to ensure that all analyses of the field samples will fall
within the calibration curve. Therefore, it is strongly recommended
that you select a minimum calibration concentration or mass that is
sufficiently above the lowest point of the calibration curve (see
examples in sections <IP_ADDRESS>.1 and <IP_ADDRESS>.2 below).
    <IP_ADDRESS> Determination of Minimum Sample Mass. Based on your
minimum calibration concentration or mass and other sample
treatments including, but not limited to, final digestate volume and
minimum sample dilution, determine the minimum sample mass.
Consideration should also be given to the Hg levels expected to be
measured in Section 2 of the sorbent traps and to the breakthrough
criteria presented in Table 9-1.
    <IP_ADDRESS>.1 Example Determination of Minimum Sample Mass for
Thermal Desorption Analysis. A thermal analysis system has been
calibrated at five Hg mass levels: 10 ng, 20 ng, 50 ng, 100 ng, 200
ng, and shown to meet the calibration performance criteria in this
method. Based on 2 times the lowest point in the calibration curve,
20 ng is selected as the minimum calibration mass. Because the
entire sample is analyzed and there are no dilutions involved, the
minimum sample mass is also 20 ng.
    Note: In this example, if the typical background (blank) Hg
levels in section 2 were relatively high (e.g., 3 to 5 ng), a sample
mass of 20 ng might not have been sufficient to ensure that the
breakthrough criteria in Table 9-1 would be met, thereby
necessitating the use of a higher point on the calibration curve
(e.g., 50 ng) as the minimum calibration and sample mass.
    <IP_ADDRESS>.2 Example Determination of Minimum Sample Mass for Acid
Leachate/Digestate Analysis. A cold vapor analysis system has been
calibrated at four Hg concentration levels: 2 ng/L, 5 ng, 10 ng/L,
20 ng/L, and shown to meet the calibration performance criteria in
this method. Based on 2 times the lowest point in the calibration
curve, 4 ng/L was selected as the minimum calibration concentration.
The final sample volume of a digestate is nominally 50 ml (0.05 L)
and the minimum dilution necessary was determined to be 1:100 by the
Analytical Matrix Interference Test of Section 8.2.1. The following
calculation would be used to determine the minimum sample mass.

Minimum sample mass = (4 ng/L) x (0.05 L) x (100) = 20 ng

    Note: In this example, if the typical background (blank) Hg
levels in section 2 were relatively high (e.g., 3 to 5 ng), a sample
mass of 20 ng might not have been sufficient to ensure that the
breakthrough criterion in Table 9-1 would be met, thereby
necessitating the use of a higher point on the calibration curve
(e.g., 10 ng/L) as the minimum calibration concentration.
    8.2.3 Hg\0\ and HgCl2 Analytical Bias Test. Before
analyzing any field samples, the laboratory must demonstrate the
ability to recover and accurately quantify Hg\0\ and
HgCl2 from the chosen sorbent media by performing the
following analytical bias test for sorbent traps spiked with Hg\0\
and HgCl2. The analytical bias test is performed at a
minimum of two distinct sorbent trap Hg loadings that will: (1)
Represent the lower and upper bound of sample Hg loadings for
application of the analytical technique to the

field samples, and (2) be used for data validation.
    <IP_ADDRESS> Hg\0\ and HgCl2 Analytical Bias Test
Procedures. Determine the lower and upper bound mass loadings. The
minimum sample mass established in Section <IP_ADDRESS> can be used for
the lower bound Hg mass loading although lower Hg loading levels are
acceptable. The upper bound Hg loading level should be an estimate
of the greatest mass loading that may result as a function of stack
concentration and volume sampled. As previously noted, this test
defines the bounds that actual field samples must be within in order
to be valid.
    <IP_ADDRESS>.1 Hg\0\ Analytical Bias Test. Analyze the front section
of three sorbent traps containing Hg\0\ at the lower bound mass
loading level and the front section of three sorbent traps
containing Hg\0\ at the upper bound mass loading level. In other
words, analyze each mass loading level in triplicate. You may refer
to Section 6.2 for spiking guidance. Prepare and analyze each spiked
trap, using the same techniques that will be used to prepare and
analyze the field samples. The average recovery for the three traps
at each mass loading level must be between 90 and 110 percent. If
multiple types of sorbent media are to be analyzed, a separate
analytical bias test is required for each sorbent material.
    <IP_ADDRESS>.2 HgCl2 Analytical Bias Test. Analyze the
front section of three sorbent traps containing HgCl2 at
the lower bound mass loading level and the front section of three
traps containing HgCl2 at the upper bound mass loading
level. HgCl2 can be spiked as a gas, or as a liquid
solution containing HgCl2. However the liquid volume
spiked must be < 100 [mu]L. Prepare and analyze each spiked trap,
using the techniques that will be used to prepare and analyze the
field samples. The average recovery for three traps at each spike
concentration must be between 90 and 110 percent. Again, if multiple
types of sorbent media are to be analyzed, a separate analytical
bias test is required for each sorbent material.
    8.2.4 Determination of Target Sample Volume. The target sample
volume is an estimate of the sample volume needed to ensure that
valid emissions data are collected (i.e., that sample mass Hg
loadings fall within the analytical calibration curve and are within
the upper and lower bounds set by the analytical bias tests). The
target sample volume and minimum sample mass can also be determined
by performing a diagnostic test run prior to initiation of formal
testing.
    Example: If the minimum sample mass is 50 ng and the
concentration of mercury in the stack gas is estimated to be 2
[mu]g/m\3\ (ng/L) then the following calculation would be used to
determine the target sample volume:

Target Sample Volume = (50 ng)/(2 ng/L) = 25 L

    Note: For the purposes of relative accuracy testing of Hg
monitoring systems under part 75 of this chapter and Performance
Specification 12A in appendix B to this part, when the stack gas Hg
concentration is expected to be very low (< 0.5 [mu]g/dscm) you may
estimate the Hg concentration at 0.5 [mu]g/dscm.
    8.2.5 Determination of Sample Run Time. Sample run time will be
a function of minimum sample mass (see Section 8.2.2), target sample
volume and nominal equipment sample flow rate. The minimum sample
run time for conducting relative accuracy test audits of Hg
monitoring systems is 30 minutes and for emissions testing to
characterize an emission source is 1 hour. The target sample run
time can be calculated using the following example.
    Example: If the target sample volume has been determined to be
25 L, then the following formula would be used to determine the
sampling time necessary to acquire 25 L of gas when sampling at a
rate of 0.4 L/min.

Sampling time (min) = 25 L / 0.4 L/min = 63 minutes

    8.2.6 Field Recovery Test. The field recovery test provides a
test program-specific verification of the performance of the
combined sampling and analytical approach. Three sets of paired
samples, one of each pair which is spiked with a known level of Hg,
are collected and analyzed and the average recovery of the spiked
samples is used to verify performance of the measurement system
under field conditions during that test program. The conduct of this
test requires an estimate or confirmation of the stack Hg
concentrations at the time of testing.
    <IP_ADDRESS> Calculation of Pre-sampling Spiking Level. Determine the
sorbent trap spiking level for the field recovery test using
estimates of the stack Hg concentration, the target sample flow
rate, and the planned sample duration. First, determine the Hg mass
expected to be collected in section 1 of the sorbent trap. The pre-
sampling spike must be within 50 to 150 percent of this expected
mass.
    Example calculation: For an expected stack Hg concentration of 5
ug/m\3\ (ng/L) a target sample rate of 0.40 liters/min, and a sample
duration of 1 hour:

(0.40 L/min)*(60 min)*(5ng/L) = 120 ng

    A Hg spike of 60 to 180 ng (50-150% of 120 ng) would be
appropriate.
    <IP_ADDRESS> Procedures. Set up two identical sampling trains. One of
the sampling trains shall be designated the spiked train and the
other the unspiked train. Spike Hg\0\ onto the front section of the
sorbent trap in the spiked train before sampling. The mass of Hg
spiked shall be 50 to 150 percent of the mass expected to be
collected with the unspiked train. Sample the stack gas with the two
trains simultaneously using the same procedures as for the field
samples (see Section 8.3). The total sample volume must be within
20 percent of the target sample volume for the field
sample test runs. Analyze the sorbent traps from the two trains
utilizing the same analytical procedures and instrumentation as for
the field samples (see Section 11.0). Determine the fraction of
spiked Hg recovered (R) using the equations in Section 12.7. Repeat
this procedure for a total of three runs. Report the individual R
values in the test report; the average of the three R values must be
between 85 and 115 percent.
    Note to section <IP_ADDRESS>: It is acceptable to perform the field
recovery test concurrent with actual test runs (e.g., through the
use of a quad probe). It is also acceptable to use the field
recovery test runs as test runs for emissions testing or for the
RATA of a Hg monitoring system under part 75 of this chapter and
Performance Specification 12A in appendix B to this part, if certain
conditions are met. To determine whether a particular field recovery
test run may be used as a RATA run, subtract the mass of the Hg\0\
spike from the total Hg mass collected in sections 1 and 2 of the
spiked trap. The difference represents the mass of Hg in the stack
gas sample. Divide this mass by the sample volume to obtain the Hg
concentration in the effluent gas stream, as measured with the
spiked trap. Compare this concentration to the corresponding Hg
concentration measured with the unspiked trap. If the paired trains
meet the relative deviation and other applicable data validation
criteria in Table 9-1, then the average of the two Hg concentrations
may be used as an emissions test run value or as the reference
method value for a RATA run.
    8.3 Sampling. This section describes the procedures and criteria
for collecting the field samples for analysis. As noted in Section
8.2.6, the field recovery test samples are also collected using
these procedures.
    8.3.1 Pre-test leak check. Perform a leak check of the sampling
system with the sorbent traps in place. For each of the paired
sampling trains, draw a vacuum in the train, and adjust the vacuum
to ~15 Hg; and, using the gas flow meter, determine leak
rate. The leak rate for an individual train must not exceed 4
percent of the target sampling rate. Once the leak check passes this
criterion, carefully release the vacuum in the sample train, then
seal the sorbent trap inlet until the probe is ready for insertion
into the stack or duct.
    8.3.2 Determination of Flue Gas Characteristics. Determine or
measure the flue gas measurement environment characteristics (gas
temperature, static pressure, gas velocity, stack moisture, etc.) in
order to determine ancillary requirements such as probe heating
requirements (if any), initial sampling rate, moisture management,
etc.
    8.3.3 Sample Collection
    <IP_ADDRESS> Remove the plug from the end of each sorbent trap and
store each plug in a clean sorbent trap storage container. Remove
the stack or duct port cap and insert the probe(s). Secure the
probe(s) and ensure that no leakage occurs between the duct and
environment.
    <IP_ADDRESS> Record initial data including the sorbent trap ID, date,
and the run start time.
    <IP_ADDRESS> Record the initial gas flow meter reading, stack
temperature, meter temperatures (if needed), and any other
appropriate information, before beginning sampling. Begin sampling
and target a sampling flow rate similar to that for the field
recovery test. Then, at regular intervals (< =5 minutes) during the
sampling period, record the date and time, the sample flow rate, the
gas meter reading, the stack temperature, the flow meter
temperatures (if using a dry gas meter), temperatures of heated
equipment such as the vacuum lines and the probes (if heated), and
the sampling system vacuum readings. Adjust the sampling flow rate
as necessary to maintain the initial sample flow

rate. Ensure that the total volume sampled for each run is within 20
percent of the total volume sampled for the field recovery test.
    <IP_ADDRESS> Data Recording. Obtain and record any essential
operating data for the facility during the test period, e.g., the
barometric pressure must be obtained for correcting sample volume to
standard conditions when using a dry gas meter. At the end of the
data collection period, record the final gas flow meter reading and
the final values of all other essential parameters.
    <IP_ADDRESS> Post-Test Leak Check. When sampling is completed, turn
off the sample pump, remove the probe(s) with sorbent traps from the
port, and carefully seal the end of each sorbent trap. Perform
another leak check of each sampling train with the sorbent trap in
place, at the maximum vacuum reached during the sampling period.
Record the leakage rates and vacuums. The leakage rate for each
train must not exceed 4 percent of the average sampling rate for the
data collection period. Following each leak check, carefully release
the vacuum in the sample train.
    <IP_ADDRESS> Sample Recovery. Recover each sampled sorbent trap by
removing it from the probe and sealing both ends. Wipe any deposited
material from the outside of the sorbent trap. Place the sorbent
trap into an appropriate sample storage container and store/preserve
in appropriate manner (see Section <IP_ADDRESS>).
    <IP_ADDRESS> Stack Gas Moisture Determination. If the moisture basis
of the measurements made with this method (dry) is different from
the moisture basis of either: (1) the applicable emission limit; or
(2) a Hg CEMS being evaluated for relative accuracy, you must
determine the moisture content of the flue gas and correct for
moisture using Method 4 in appendix A-3 to this part. If correction
of the measured Hg concentrations for moisture is required, at least
one Method 4 moisture determination shall be made during each test
run.
    <IP_ADDRESS> Sample Handling, Preservation, Storage, and Transport.
While the performance criteria of this approach provide for
verification of appropriate sample handling, it is still important
that the user consider, determine, and plan for suitable sample
preservation, storage, transport, and holding times for these
measurements. Therefore, procedures in ASTM WK223 ``Guide for
Packaging and Shipping Environmental Samples for Laboratory
Analysis'' shall be followed for all samples, where appropriate. To
avoid Hg contamination of the samples, special attention should be
paid to cleanliness during transport, field handling, sampling,
recovery, and laboratory analysis, as well as during preparation of
the sorbent cartridges. Collection and analysis of blank samples
(e.g., reagent, sorbent, field, etc.,) is useful in verifying the
absence or source of contaminant Hg.
    <IP_ADDRESS> Sample Custody. Proper procedures and documentation for
sample chain of custody are critical to ensuring data integrity. The
chain of custody procedures in ASTM D4840-99 ``Standard Guide for
Sampling Chain-of-Custody Procedures'' shall be followed for all
samples (including field samples and blanks).

9.0 Quality Assurance and Quality Control

    Table 9-1 summarizes the QA/QC performance criteria that are
used to validate the Hg emissions data from Method 30B sorbent trap
measurement systems.

                      Table 9-1.--Quality Assurance/Quality Control Criteria for Method 30B
----------------------------------------------------------------------------------------------------------------
     QA/QC test or specification         Acceptance criteria           Frequency         Consequences if not met
----------------------------------------------------------------------------------------------------------------
Gas flow meter calibration (At 3       Calibration factor (Yi)  Prior to initial use     Recalibrate at 3 points
 settings or points).                   at each flow rate must   and when post-test       until the acceptance
                                        be within    check is not within      criteria are met.
                                        2% of the average         5% of Y.
                                        value (Y).
Gas flow meter post-test calibration   Calibration factor (Yi)  After each field test.   Recalibrate gas flow
 check (Single-point).                  must be within < plus-    For mass flow meters,    meter at 3 points to
                                        minus> 5% of the Y       must be done on-site,    determine a new value
                                        value from the most      using stack gas.         of Y. For mass flow
                                        recent 3-point                                    meters, must be done
                                        calibration.                                      on-site, using stack
                                                                                gas. Apply the new Y
                                                                                value to the field
                                                                                test data.
Temperature sensor calibration.......  Absolute temperature     Prior to initial use     Recalibrate; sensor may
                                        measures by sensor       and before each test     not be used until
                                        within       thereafter.              specification is met.
                                        1.5% of a reference
                                        sensor.
Barometer calibration................  Absolute pressure        Prior to initial use     Recalibrate; instrument
                                        measured by instrument   and before each test     may not be used until
                                        within  10   thereafter.              specification is met.
                                        mm Hg of reading with
                                        a mercury barometer.
Pre-test leak check..................  < = 4% of target          Prior to sampling......  Sampling shall not
                                        sampling rate.                                    commence until the
                                                                                leak check is passed.
Post-test leak check.................  < = 4% of average         After sampling.........  Sample invalidated.*
                                        sampling rate.
Analytical matrix interference test    Establish minimum        Prior to analyzing any   Field sample results
 (wet chemical analysis, only).         dilution (if any)        field samples; repeat    not validated.
                                        needed to eliminate      for each type of
                                        sorbent matrix           sorbent used.
                                        interferences.
Analytical bias test.................  Average recovery         Prior to analyzing       Field samples shall not
                                        between 90% and 110%     field samples and        be analyzed until the
                                        for Hg\0\ and HgCl2 at   prior to use of new      percent recovery
                                        each of the 2 spike      sorbent media.           criteria has been met.
                                        concentration levels.
Multipoint analyzer calibration......  Each analyzer reading    On the day of analysis,  Recalibrate until
                                        withini      before analyzing any     successful.
                                        10% of true value and    samples.
                                        r\2\ >= 0.99.
Analysis of independent calibration    Within  10%  Following daily          Recalibrate and repeat
 standard.                              of true value.           calibration, prior to    independent standard
                                                                 analyzing field          analysis until
                                                                 samples.                 successful.
Analysis of continuing calibration     Within  10%  Following daily          Recalibrate and repeat
 verification standard (CCVS).          of true value.           calibration, after       independent standard
                                                                 analyzing < =10 field     analysis, reanalyze
                                                                 samples, and at end of   samples until
                                                                 each set of analyses.    successful, if
                                                                                possible; for
                                                                                destructive
                                                                                techniques, samples
                                                                                invalidated.
Test run total sample volume.........  Within  20%  Each individual sample.  Sample invalidated.
                                        of total volume
                                        sampled during field
                                        recovery test.
Sorbent trap section 2 breakthrough..  < 10% of section 1 Hg     Every sample...........  Sample invalidated.*
                                        mass for Hg
                                        concentrations > 1
                                        [mu]g/dscm;.

                                       < = 20% of section 1 Hg
                                        mass for Hg
                                        concentrations < = 1
                                        [mu]g/dscm.
Paired sorbent trap agreement........  < = 10% Relative          Every run..............  Run invalidated.*
                                        Deviation (RD) mass
                                        for Hg concentrations
                                        > 1 [mu]g/dscm;
                                       < = 20% RD or < = 0.2
                                        [mu]g/dscm absolute
                                        difference for Hg
                                        concentrations < = 1
                                        [mu]g/dscm.
Sample analysis......................  Within valid             All Section 1 samples    Reanalyze at more
                                        calibration range        where stack Hg           concentrated level if
                                        (within calibration      concentation is >= 0.5   possible, samples
                                        curve).                  [mu]g/dscm.              invalidated if not
                                                                                within calibrated
                                                                                range.
Sample analysis......................  Within bounds of Hg\0\   All Section 1 samples    Expand bounds of Hg\0\
                                        and HgCl2 Analytical     where stack Hg           and HgCl2 Analytical
                                        Bias Test.               concentration is >=      Bias Test; if not
                                                                 0.5 [mu]g/dscm.          successful, samples
                                                                                invalidated.
Field recovery test..................  Average recovery         Once per field test....  Field sample runs not
                                        between 85% and 115%                              validated without
                                        for Hg\0\.                                        successful field
                                                                                recovery test.
----------------------------------------------------------------------------------------------------------------
* And data from the pair of sorbent traps are also invalidated.

10.0 Calibration and Standardization

    10.1 Only NIST-certified and NIST-traceable calibration
standards (i.e., calibration gases, solutions, etc.) shall be used
for the spiking and analytical procedures in this method.
    10.2 Gas Flow Meter Calibration.
    10.2.1 Preliminaries. The manufacturer or equipment supplier of
the gas flow meter should perform all necessary set-up, testing,
programming, etc., and should provide the end user with any
necessary instructions, to ensure that the meter will give an
accurate readout of dry gas volume in standard cubic meters for this
method.
    10.2.2 Initial Calibration. Prior to its initial use, a
calibration of the gas flow meter shall be performed. The initial
calibration may be done by the manufacturer, by the equipment
supplier, or by the end user. If the flow meter is volumetric in
nature (e.g., a dry gas meter), the manufacturer or end user may
perform a direct volumetric calibration using any gas. For a mass
flow meter, the manufacturer, equipment supplier, or end user may
calibrate the meter using either: (1) A bottled gas mixture
containing 12 0.5% CO2, 7 0.5%
O2, and balance N2 (when this method is
applied to coal-fired boilers); (2) a bottled gas mixture containing
CO2, O2, and N2 in proportions
representative of the expected stack gas composition; or (3) the
actual stack gas.
    <IP_ADDRESS> Initial Calibration Procedures. Determine an average
calibration factor (Y) for the gas flow meter by calibrating it at
three sample flow rate settings covering the range of sample flow
rates at which the sampling system will be operated. You may either
follow the procedures in section 10.3.1 of Method 5 in appendix A-3
to this part or in section 16 of Method 5 in appendix A-3 to this
part. If a dry gas meter is being calibrated, use at least five
revolutions of the meter at each flow rate.
    <IP_ADDRESS> Alternative Initial Calibration Procedures.
Alternatively, you may perform the initial calibration of the gas
flow meter using a reference gas flow meter (RGFM). The RGFM may be:
(1) A wet test meter calibrated according to section 10.3.1 of
Method 5 in appendix A-3 to this part; (2) a gas flow metering
device calibrated at multiple flow rates using the procedures in
section 16 of Method 5 in appendix A-3 to this part; or (3) a NIST-
traceable calibration device capable of measuring volumetric flow to
an accuracy of 1 percent. To calibrate the gas flow meter using the
RGFM, proceed as follows: While the Method 30B sampling system is
sampling the actual stack gas or a compressed gas mixture that
simulates the stack gas composition (as applicable), connect the
RGFM to the discharge of the system. Care should be taken to
minimize the dead volume between the gas flow meter being tested and
the RGFM. Concurrently measure dry stack gas volume with the RGFM
and the flow meter being calibrated for at least 10 minutes at each
of three flow rates covering the typical range of operation of the
sampling system. For each set of concurrent measurements, record the
total sample volume, in units of dry standard cubic meters (dscm),
measured by the RGFM and the gas flow meter being tested.
    <IP_ADDRESS> Initial Calibration Factor. Calculate an individual
calibration factor Yi at each tested flow rate from
section <IP_ADDRESS> or <IP_ADDRESS> of this method (as applicable) by
taking the ratio of the reference sample volume to the sample volume
recorded by the gas flow meter. Average the three Yi
values, to determine Y, the calibration factor for the flow meter.
Each of the three individual values of Yi must be within
0.02 of Y. Except as otherwise provided in sections
<IP_ADDRESS> and <IP_ADDRESS> of this method, use the average Y value from
the initial 3-point calibration to adjust subsequent gas volume
measurements made with the gas flow meter.
    <IP_ADDRESS> Pretest On-Site Calibration Check (Optional). For a
mass flow meter, if the most recent 3-point calibration of the flow
meter was performed using a compressed gas mixture, you may want to
conduct the following on-site calibration check prior to testing, to
ensure that the flow meter will accurately measure the volume of the
stack gas: While sampling stack gas, check the calibration of the
flow meter at one intermediate flow rate setting representative of
normal operation of the sampling system. If the pretest calibration
check shows that the value of Yi, the calibration factor
at the tested flow rate, differs from the current value of Y by more
than 5 percent, perform a full 3-point recalibration of the meter
using stack gas to determine a new value of Y, and (except as
otherwise provided in section <IP_ADDRESS> of this method) apply the new
Y value to the data recorded during the field test.
    <IP_ADDRESS> Post-Test Calibration Check. Check the calibration of
the gas flow meter following each field test at one intermediate
flow rate setting, either at, or in close proximity to, the average
sample flow rate during the field test. For dry gas meters, ensure
at least three revolutions of the meter during the calibration
check. For mass flow meters, this check must be performed before
leaving the test site, while sampling stack gas. If a one-point
calibration check shows that the value of Yi at the
tested flow rate differs by more than 5 percent from the current
value of Y, repeat the full 3-point calibration procedure to
determine a new value of Y, and apply the new Y value to the gas
volume measurements made with the gas flow meter during the field
test that was just completed. For mass flow meters, perform the 3-
point recalibration while sampling stack gas.
    10.3 Thermocouples and Other Temperature Sensors. Use the
procedures and criteria in Section 10.3 of Method 2 in Appendix A-1
to this part to calibrate in-stack temperature sensors and
thermocouples. Dial thermometers shall be calibrated against
mercury-in-glass thermometers. Calibrations must be performed prior
to initial use and before each field test thereafter. At each
calibration point, the absolute temperature measured by the
temperature sensor must agree to within 1.5 percent of
the temperature measured with the reference sensor, otherwise the
sensor may not continue to be used.

    10.4 Barometer. Calibrate against a mercury barometer as per
Section 10.6 of Method 5 in appendix A-3 to this part. Calibration
must be performed prior to initial use and before each test program,
and the absolute pressure measured by the barometer must agree to
within +10 mm Hg of the pressure measured by the mercury barometer,
otherwise the barometer may not continue to be used.
    10.5 Other Sensors and Gauges. Calibrate all other sensors and
gauges according to the procedures specified by the instrument
manufacturer(s).
    10.6 Analytical System Calibration. See Section 11.1 of this
method.

11.0 Analytical Procedures

    The analysis of Hg in the field and quality control samples may
be conducted using any instrument or technology capable of
quantifying total Hg from the sorbent media and meeting the
performance criteria in this method. Because multiple analytical
approaches, equipment and techniques are appropriate for the
analysis of sorbent traps, it is not possible to provide detailed,
technique-specific analytical procedures. As they become available,
detailed procedures for a variety of candidate analytical approaches
will be posted at http://www.epa.gov/ttn/emc.

    11.1 Analytical System Calibration. Perform a multipoint
calibration of the analyzer at three or more upscale points over the
desired quantitative range (multiple calibration ranges shall be
calibrated, if necessary). The field samples analyzed must fall
within a calibrated, quantitative range and meet the performance
criteria specified below. For samples suitable for aliquotting, a
series of dilutions may be needed to ensure that the samples fall
within a calibrated range. However, for sorbent media samples
consumed during analysis (e.g., when using thermal desorption
techniques), extra care must be taken to ensure that the analytical
system is appropriately calibrated prior to sample analysis. The
calibration curve range(s) should be determined such that the levels
of Hg mass expected to be collected and measured will fall within
the calibrated range. The calibration curve may be generated by
directly introducing standard solutions into the analyzer or by
spiking the standards onto the sorbent media and then introducing
into the analyzer after preparing the sorbent/standard according to
the particular analytical technique. For each calibration curve, the
value of the square of the linear correlation coefficient, i.e.,
r\2\, must be [gteqt]0.99, and the analyzer response must be within
10 percent of the reference value at each upscale
calibration point. Calibrations must be performed on the day of the
analysis, before analyzing any of the samples. Following
calibration, an independent standard shall be analyzed. The measured
value of the independently prepared standard must be within < plus-
minus>10 percent of the expected value.
    11.2 Sample Preparation. Carefully separate the sections of each
sorbent trap. Combine for analysis all materials associated with
each section; any supporting substrate that the sample gas passes
through prior to entering a media section (e.g., glass wool
separators, acid gas traps, etc.) must be analyzed with that
segment.
    11.3 Field Sample Analyses. Analyze the sorbent trap samples
following the same procedures that were used for conducting the
Hg\0\ and HgCl2 analytical bias tests. The individual
sections of the sorbent trap and their respective components must be
analyzed separately (i.e., section 1 and its components, then
section 2 and its components). All sorbent trap section 1 sample
analyses must be within the calibrated range of the analytical
system. For wet analyses, the sample can simply be diluted to fall
within the calibrated range. However, for the destructive thermal
analyses, samples that are not within the calibrated range cannot be
re-analyzed. As a result, the sample cannot be validated, and
another sample must be collected. It is strongly suggested that the
analytical system be calibrated over multiple ranges so that
thermally analyzed samples do fall within the calibrated range. The
total mass of Hg measured in each sorbent trap section 1 must also
fall within the lower and upper mass limits established during the
initial Hg\0\ and HgCl2 analytical bias test. If a sample
is analyzed and found to fall outside of these limits, it is
acceptable for an additional Hg\0\ and HgCl2 analytical
bias test to be performed that now includes this level. However,
some samples (e.g., the mass collected in trap section 2 or the mass
collected in trap section 1 when the stack gas concentration is < 0.5
[mu]g/m3), may have Hg levels so low that it may not be possible to
quantify them in the analytical system's calibrated range. Because a
reliable estimate of these low-level Hg measurements is necessary to
fully validate the emissions data, the MDL (see section <IP_ADDRESS> of
this method) is used to establish the minimum amount that can be
detected and reported. If the measured mass or concentration is
below the lowest point in the calibration curve and above the MDL,
the analyst must do the following: estimate the mass or
concentration of the sample based on the analytical instrument
response relative to an additional calibration standard at a
concentration or mass between the MDL and the lowest point in the
calibration curve. This is accomplished by establishing a response
factor (e.g., area counts per Hg mass or concentration) and
estimating the amount of Hg present in the sample based on the
analytical response and this response factor.
    Example: The analysis of a particular sample results in a
measured mass above the MDL, but below the lowest point in the
calibration curve which is 10 ng. An MDL of 1.3 ng Hg has been
established by the MDL study. A calibration standard containing 5 ng
of Hg is analyzed and gives an analytical response of 6,170 area
counts, which equates to a response factor of 1,234 area counts/ng
Hg. The analytical response for the sample is 4,840 area counts.
Dividing the analytical response for the sample (4,840 area counts)
by the response factor gives 3.9 ng Hg, which is the estimated mass
of Hg in the sample.
    11.4 Analysis of Continuing Calibration Verification Standard
(CCVS). After no more than 10 samples and at the end of each set of
analyses, a continuing calibration verification standard must be
analyzed. The measured value of the continuing calibration standard
must be within 10 percent of the expected value.
    11.5 Blanks. The analysis of blanks is optional. The analysis of
blanks is useful to verify the absence of, or an acceptable level
of, Hg contamination. Blank levels should be considered when
quantifying low Hg levels and their potential contribution to
meeting the sorbent trap section 2 breakthrough requirements;
however, correcting sorbent trap results for blank levels is
prohibited.

12.0 Calculations and Data Analysis

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

B = Breakthrough (%).
Bws = Moisture content of sample gas as measured by
Method 4, percent/100.
Ca = Concentration of Hg for the sample collection
period, for sorbent trap ``a'' ([mu]g/dscm).
Cb = Concentration of Hg for the sample collection
period, for sorbent trap ``b'' ([mu]g/dscm).
Cd = Hg concentration, dry basis ([mu]g/dscm).
Crec = Concentration of spiked compound measured ([mu]g/
m\3\).
Cw = Hg concentration, wet basis ([mu]g/m\3\).
m1 = Mass of Hg measured on sorbent trap section 1
([mu]g).
m2 = Mass of Hg measured on sorbent trap section 2
([mu]g).
mrecovered = Mass of spiked Hg recovered in Analytical
Bias or Field Recovery Test ([mu]g).
ms = Total mass of Hg measured on spiked trap in Field
Recovery Test ([mu]g).
mspiked = Mass of Hg spiked in Analytical Bias or Field
Recovery Test ([mu]g).
mu = Total mass of Hg measured on unspiked trap in Field
Recovery Test ([mu]g).
R = Percentage of spiked mass recovered (%).
RD = Relative deviation between the Hg concentrations from traps
``a'' and ``b'' (%).
vs = Volume of gas sampled, spiked trap in Field Recovery
Test (dscm).
Vt = Total volume of dry gas metered during the
collection period (dscm); for the purposes of this method, standard
temperature and pressure are defined as 20 [deg]C and 760 mm Hg,
respectively.
vu = Volume of gas sampled, unspiked trap in Field
Recovery Test (dscm).

    12.2 Calculation of Spike Recovery (Analytical Bias Test).
Calculate the percent recovery of Hg\0\ and HgCl2 using
Equation 30B-1.
[GRAPHIC] [TIFF OMITTED] TR07SE07.028

    12.3 Calculation of Breakthrough. Use Equation 30B-2 to
calculate the percent breakthrough to the second section of the
sorbent trap.
[GRAPHIC] [TIFF OMITTED] TR07SE07.029

    12.4 Calculation of Hg Concentration. Calculate the Hg
concentration measured with sorbent trap ``a'', using Equation 30B-
3.
[GRAPHIC] [TIFF OMITTED] TR07SE07.030

    For sorbent trap ``b'', replace ``Ca '' with
``Cb '' in Equation 30B-3. Report the average
concentration, i.e., \1/2\ (Ca + Cb).
    12.5 Moisture Correction. Use Equation 30B-4 if your
measurements need to be corrected to a wet basis.
[GRAPHIC] [TIFF OMITTED] TR07SE07.031

    12.6 Calculation of Paired Trap Agreement. Calculate the
relative deviation (RD) between the Hg concentrations measured with
the paired sorbent traps using Equation 30B-5.
[GRAPHIC] [TIFF OMITTED] TR07SE07.032

    12.7 Calculation of Measured Spike Hg Concentration (Field
Recovery Test). Calculate the measured spike concentration using
Equation 30B-6.
[GRAPHIC] [TIFF OMITTED] TR07SE07.033

    Then calculate the spiked Hg recovery, R, using Equation 30B-7.
    [GRAPHIC] [TIFF OMITTED] TR07SE07.034

13.0 Method Performance

    How do I validate my data? Measurement data are validated using
initial, one-time laboratory tests coupled with test program-
specific tests and procedures. The analytical matrix interference
test and the Hg\0\ and HgCl2 analytical bias test
described in Section 8.2 are used to verify the appropriateness of
the selected analytical approach(es) as well as define the valid
working ranges for sample analysis. The field recovery test serves
to verify the performance of the combined sampling and analysis as
applied for each test program. Field test samples are validated by
meeting the above requirements as well as meeting specific sampling
requirements (i.e., leak checks, paired train agreement, total
sample volume agreement with field recovery test samples) and
analytical requirements (i.e., valid calibration curve, continuing
calibration performance, sample results within calibration curve and
bounds of Hg\0\ and HgCl2 analytical bias test). Complete
data validation requirements are summarized in Table 9-1.

14.0 Pollution Prevention [Reserved]

15.0 Waste Management [Reserved]

16.0 References

    1. EPA Traceability Protocol for Qualification and Certification
of Elemental Mercury Gas Generators, expected publication date
December 2008, see http://www.epa.gov/ttn/emc.

    2. EPA Traceability Protocol for Qualification and Certification
of Oxidized Mercury Gas Generators, expected publication date
December 2008, see http://www.epa.gov/ttn/emc.

    3. EPA Traceability Protocol for Assay and Certification of
Gaseous Calibration Standards, expected revision publication date
December 2008, see http://www.epa.gov/ttn/emc.

17.0 Figures and Tables

BILLING CODE 6560-50-C

[GRAPHIC] [TIFF OMITTED] TR07SE07.026

Appendix B [Amended]

0
3. Amend Performance Specification 12A in Appendix B to part 60 by
revising sections 8.6.2, 8.6.4, 8.6.5, and <IP_ADDRESS> to read as follows:

Performance Specification 12A--Specifications and Test Procedures for
Total Vapor Phase Mercury Continuous Emission Monitoring Systems in
Stationary Sources

* * * * *
    8.6.2 RM. Unless otherwise specified in an applicable subpart of
the regulations, use Method 29, Method 30A, or Method 30B in
appendix A to this part or American Society of Testing and Materials
(ASTM) Method D6784-02 (incorporated by reference, see Sec.  60.17)
as the RM for Hg concentration. Do not include the filterable
portion of the sample when making comparisons to the CEMS results.
When Method 29, Method 30B, or ASTM D6784-02 is used, conduct the RM
test runs with paired or duplicate sampling systems. When Method 30A
is used, paired sampling systems are not required. If the RM and
CEMS measure on a different moisture basis, data derived with Method
4 in appendix A to this part shall also be obtained during the RA
test.
* * * * *
    8.6.4 Number and Length of RM and Tests. Conduct a minimum of
nine RM test runs. When Method 29, Method 30B, or ASTM D6784-02 is
used, only test runs for which the paired RM trains meet the
relative deviation criteria (RD) of this PS shall be used in the RA
calculations. In addition, for Method 29 and ASTM D6784-02, use a
minimum sample time of 2 hours and for Method 30A use a minimum
sample time of 30 minutes.

    Note: More than nine sets of RM tests may be performed. If this
option is chosen, paired RM test results may be excluded so long as
the total number of paired RM test results used to determine the
CEMS RA is greater than or equal to nine. However, all data must be
reported including the excluded data.

    8.6.5 Correlation of RM and CEMS Data. Correlate the CEMS and
the RM test data as to the time and duration by first determining
from the CEMS final output (the one used for reporting) the
integrated average pollutant concentration for each RM test period.
Consider system response time, if important, and confirm that the
results are on a consistent moisture basis with the RM test. Then,
compare each integrated CEMS value against the corresponding RM
value. When Method 29, Method 30A, Method 30B, or ASTM D6784-02 is
used, compare each CEMS value against the corresponding average of
the paired RM values.
    8.6.6 * * *
    <IP_ADDRESS> When Method 29, Method 30B, or ASTM D6784-02 is used,
outliers are identified through the determination of relative
deviation (RD) of the paired RM tests. Data that do not meet the
criteria should be flagged as a data quality problem. The primary
reason for performing paired RM sampling is to ensure the quality of
the RM data. The percent RD of paired data is the parameter used to
quantify data quality. Determine RD for two paired data points as
follows:
[GRAPHIC] [TIFF OMITTED] TR07SE07.035

where Ca and Cb are concentration values
determined from each of the two samples, respectively.
* * * * *

PART 72--PERMITS REGULATION

0
4. The authority citation for part 72 continues to read as follows:

    Authority: 42 U.S.C. 7601 and 7651, et seq.

0
5. Revise the definition of ``sorbent trap monitoring system'' in Sec.
72.2 as follows:

Sec.  72.2  Definitions.

* * * * *
    Sorbent trap monitoring system means the equipment required by part
75 of this chapter for the continuous monitoring of Hg emissions, using
paired sorbent traps containing iodated charcoal (IC) or other suitable
reagents. This excepted monitoring system consists of a probe, the
paired sorbent traps, an umbilical line, moisture removal components,
an air tight sample pump, a gas flow meter, and an automated data
acquisition and handling system. The monitoring system samples the
stack gas at a rate proportional to the stack gas volumetric flowrate.
The sampling is a batch process. Using the sample volume measured by
the gas flow meter and the results of the analyses of the sorbent
traps, the average mercury concentration in the stack gas for the
sampling period is determined, in units of micrograms per dry standard
cubic meter ([mu]g/dscm). Mercury mass emissions for each hour in the
sampling period are calculated using the average Hg concentration for
that period, in conjunction with contemporaneous hourly measurements of
the stack gas flow rate, corrected for the stack moisture content.
* * * * *

PART 75--CONTINUOUS EMISSION MONITORING

0
6. The authority citation for part 75 continues to read as follows:

    Authority:  42 U.S.C. 7601, 7651k, and 7651k note.

0
7. Amend Sec.  75.15 as follows:
0
a. Revise paragraph (f);
0
b. Revise paragraph (i); and
0
c. Add new paragraph (k).
    The revisions and additions read as follows:

Sec.  75.15  Special provisions for measuring Hg mass emissions using
the excepted sorbent trap monitoring methodology.

* * * * *
    (f) At the beginning and end of each sample collection period, and
at least once in each unit operating hour during the collection period,
the gas flow meter reading shall be recorded.
* * * * *
    (i) All unit operating hours for which valid Hg concentration data
are obtained with the primary sorbent trap monitoring system (as
verified using the quality assurance procedures in appendix K to this
part) shall be reported in the electronic quarterly report under Sec.
75.84(f). For hours in which data from the primary monitoring system
are invalid, the owner or operator may, in accordance with Sec.
75.20(d), report valid Hg concentration data from: A certified
redundant backup CEMS or sorbent trap monitoring system; a certified
non-redundant backup CEMS or sorbent trap monitoring system; or an
applicable reference method under Sec.  75.22. If no quality-assured Hg
concentration are available for a particular hour, the owner or
operator shall report the appropriate substitute data value in
accordance with Sec.  75.39.
* * * * *
    (k) During each RATA of a sorbent trap monitoring system, the type
of sorbent material used by the traps shall be the same as for daily
operation of the monitoring system. A new pair of traps shall be used
for each RATA run. However, the size of the traps used for the RATA may
be smaller than the traps used for daily operation of the system.
* * * * *

0
8. Amend Sec.  75.20 by adding new paragraph (d)(2)(ix) to read as
follows:

Sec.  75.20  Initial certification and recertification procedures.

* * * * *
    (d)* * *
    (2)* * *
    (ix) For non-redundant backup Hg CEMS and sorbent trap monitoring
systems, and for like-kind replacement Hg analyzers, the following
provisions apply in addition to, or, in some cases, in lieu of, the
general requirements in paragraphs (d)(2)(i) through (d)(2)(viii) of
this section:
    (A) When a certified sorbent trap monitoring system is brought into
service as a regular non-redundant backup monitoring system, the system
shall be operated according to the procedures in Sec.  75.15 and
appendix K of this part;
    (B) When a regular non-redundant backup Hg CEMS or a like-kind

replacement Hg analyzer is brought into service, a linearity check with
elemental Hg standards, as described in paragraph (c)(1)(ii) of this
section and section 6.2 of appendix A of this part, and a single-point
system integrity check, as described in section 2.6 of appendix B of
this part, shall be performed. Alternatively, a 3-level system
integrity check, as described in paragraph (c)(1)(vi) of this section
and paragraph (g) of section 6.2 in appendix A of this part, may be
performed in lieu of these two tests.
    (C) The weekly single-point system integrity checks described in
section 2.6 of appendix B of this part are required as long as a non-
redundant backup Hg CEMS or like-kind replacement Hg analyzer remains
in service, unless the daily calibrations of the Hg analyzer are done
using a NIST-traceable source of oxidized Hg.
* * * * *

0
9. Amend Sec.  75.57 by revising paragraph (j)(7) to read as follows:

Sec.  75.57  General recordkeeping provisions.

* * * * *
    (j) * * *
    (7) Record the gas flow meter reading (in dscm, rounded to the
nearest hundreth) at the beginning and end of the collection period and
at least once in each unit operating hour during the collection period.
* * * * *

0
10. Amend Sec.  75.81 by revising paragraph (a)(1) to read as follows:

Sec.  75.81  Monitoring of Hg mass emissions and heat input at the unit
level.

* * * * *
    (a) * * *
    (1) A Hg concentration monitoring system (as defined in Sec.  72.2
of this chapter) or a sorbent trap monitoring system (as defined in
Sec.  72.2 of this chapter), to measure the mass concentration of total
vapor phase Hg in the flue gas, including the elemental and oxidized
forms of Hg, in micrograms per standard cubic meter ([mu]g/scm); and
* * * * *

0
11. Amend Sec.  75.84 by revising paragraph (f)(1)(ii)(J) to read as
follows:

Sec.  75.84  Recordkeeping and Reporting.

* * * * *
    (f) * * *
    (1) * * *
    (ii) * * *
    (J) For units using sorbent trap monitoring systems, the hourly gas
flow meter readings taken between the initial and final meter readings
for the data collection period; and
* * * * *

Appendix A to Part 75--[Amended]

0
12. Amend Appendix A to part 75 by removing the twentieth sentence in
paragraph (a) of section 6.5.7 which currently reads ``For the RATA of
a sorbent trap monitoring system, use the same size trap that is used
for daily operation of the monitoring system.'' and adding in its place
``For the RATA of a sorbent trap monitoring system, the type of sorbent
material used by the traps shall be the same as for daily operation of
the monitoring system; however, the size of the traps used for the RATA
may be smaller than the traps used for daily operation of the
system.''.

0
13. Amend Appendix B to part 75 by revising section 1.5.2 to read as
follows:

Appendix B to Part 75--Quality Assurance and Quality Control Procedures

* * * * *

1.5.2 Monitoring System Integrity and Data Quality

    Explain the procedures used to perform the leak checks when
sorbent traps are placed in service and removed from service. Also
explain the other QA procedures used to ensure system integrity and
data quality, including, but not limited to, gas flow meter
calibrations, verification of moisture removal, and ensuring air-
tight pump operation. In addition, the QA plan must include the data
acceptance and quality control criteria in section 8 of appendix K
to this part. All reference meters used to calibrate the gas flow
meters (e.g., wet test meters) shall be periodically recalibrated.
Annual, or more frequent, recalibration is recommended. If a NIST-
traceable calibration device is used as a reference flow meter, the
QA plan must include a protocol for ongoing maintenance and periodic
recalibration to maintain the accuracy and NIST-traceability of the
calibrator.
* * * * *

0
14. Amend Appendix K to part 75 as follows:
0
a. Amend section 5.1 by revising Figure K-1;
0
b. Revise section 5.1.3;
0
c. Revise section 5.1.5;
0
d. Revise section 7.1.3;
0
e. Revise section 7.2.3;
0
f. Revise section 7.2.5;
0
g. Amend section 8.0 by revising Table K-1;
0
h. Revise section 9.2;
0
i. Revise section 10.4;
0
j. Remove and reserve section 11.5;
0
k. Revise section 11.6; and
0
l. Revise section 11.7.
    The revisions and additions read as follows:

Appendix K to Part 75--Quality Assurance and Operating Procedures for
Sorbent Trap Monitoring Systems

* * * * *

5.1 * * *

BILLING CODE 6560-50-C

[GRAPHIC] [TIFF OMITTED] TR07SE07.027

* * * * *

5.1.3 Moisture Removal Device

    A robust moisture removal device or system, suitable for
continuous duty (such as a Peltier cooler), shall be used to remove
water vapor from the gas stream prior to entering the gas flow
meter.
* * * * *

5.1.5 Gas Flow Meter

    A gas flow meter (such as a dry gas meter, thermal mass flow
meter, or other suitable measurement device) shall be used to
determine the total sample volume on a dry basis, in units of
standard cubic meters. The meter must be sufficiently accurate to
measure the total sample volume to within 2 percent and must be
calibrated at selected flow rates across the range of sample flow
rates at which the sorbent trap monitoring system typically
operates. The gas flow meter shall be equipped with any necessary
auxiliary measurement devices (e.g., temperature sensors, pressure
measurement devices) needed to correct the sample volume to standard
conditions.
* * * * *

7.1.3 Pre-test Leak Check

    Perform a leak check with the sorbent traps in place. Draw a
vacuum in each sample train. Adjust the vacuum in the sample train
to ~15[sec] Hg. Using the gas flow meter, determine leak rate. The
leakage rate must not exceed 4 percent of the target sampling rate.
Once the leak check passes this criterion, carefully release the
vacuum in the sample train then seal the sorbent trap inlet until
the probe is ready for insertion into the stack or duct.
* * * * *

7.2.3 Flow Rate Control

    Set the initial sample flow rate at the target value from
section 7.1.1 of this appendix. Record the initial gas flow meter
reading, stack temperature (if needed to convert to standard
conditions), meter temperatures (if needed), etc. Then, for every
operating hour during the sampling period, record the date and time,
the sample flow rate, the gas flow meter reading, the stack
temperature (if needed), the flow meter temperatures (if needed),
temperatures of heated equipment such as the vacuum lines and the
probes (if heated), and the sampling system vacuum readings. Also,
record the stack gas flow rate, as measured by the certified flow
monitor, and the ratio of the stack gas flow rate to the sample flow
rate. Adjust the sampling flow rate to maintain proportional
sampling, i.e., keep the ratio of the stack gas flow rate to sample
flow rate constant, to within 25 percent of the
reference ratio from the first hour of the data collection period
(see section 11 of this appendix).
* * * * *

7.2.5 Essential Operating Data

    Obtain and record any essential operating data for the facility
during the test period, e.g., the barometric pressure for correcting
the sample volume measured by a dry gas meter to standard
conditions. At the end of the data collection period, record the
final gas flow meter reading and the final values of all other
essential parameters.
* * * * *

8.0 * * *

           Table K-1.--Quality Assurance/Quality Control Criteria for Sorbent Trap Monitoring Systems
----------------------------------------------------------------------------------------------------------------
     QA/QC test or specification         Acceptance criteria           Frequency         Consequences if not met
----------------------------------------------------------------------------------------------------------------
Pre-test leak check..................  < =4% of target sampling  Prior to Sampling......  Sampling shall not
                                        rate.                                             commence until the
                                                                                leak check is passed.
Post-test leak check.................  < =4% of average          After sampling.........  Sample check
                                        sampling rate.                                    invalidated.**
Ratio of stack gas flow rate to        Maintain within < plus-   Every hour throughout    Case-by-case
 sample flow rate.                      minus>25% of initial     data collection period.  evaluation.
                                        ratio from first hour
                                        of data collection
                                        period.
Sorbent trap section 2 breakthrough..  < =5% of Section 1 Hg     Every sample...........  Sample invalidated.**
                                        mass.
Paired sorbent trap agreement........  < =10% Relative           Every sample...........  Sample invalidated.**
                                        Deviation (RD).
Spike recovery study.................  Average recovery         Prior to analyzing       Field samples shall not
                                        between 85% and 115%     field samples and        be analyzed until the
                                        for each of the 3        prior to use of new      percent recovery
                                        spike concentration      sorbent media.           criterion has been
                                        levels.                                           met.
Multipoint analyzer calibration......  Each analyzer reading    On the day of analysis,  Recalibrate until
                                        within 10%   before analyzing any     successful.
                                        of true value and r\2\   samples.
                                        >=0.99.
Analysis of independent calibration    Within 10%   Following daily          Recalibrate and repeat
 standard.                              of true value.           calibration, prior to    independent standard
                                                                 analyzing field.         analysis samples until
                                                                                successful.
Spike recovery from section 3 of       75-125% of spike amount  Every sample...........  Sample invalidated.**
 sorbent trap.
RATA.................................  RA < =20.0% or Mean       For initial              Data from the system
                                        difference < =1.0         certification and        are invalidated until
                                        [mu]gm/dscm for low      annually thereafter.     a RATA is passed.
                                        emitters.
Gas flow meter calibration (At 3       Calibration factor (Y)   Prior to initial use     Recalibrate the meter
 settings initially, and 1 setting      within 5%    and at least quarterly   at three settings to
 thereafter).                           of average value from    thereafter.              determine a new value
                                        the initial (3-point)                             of Y.
                                        calibration.
Temperature sensor calibration.......  Absolute temperature     Prior to initial use     Recalibrate. Sensor may
                                        measured by sensor       and at least quarterly   not be used until
                                        within < plus-            thereafter.              specification is met.
                                        minus>1.5% of a
                                        reference sensor.
Barometer calibration................  Absolute pressure        Prior to initial use     Recalibrate. Instrument
                                        measured by instrument   and at least quarterly   may not be used until
                                        within 10    thereafter.              specification is met.
                                        mm Hg of reading with
                                        a mercury barometer.
----------------------------------------------------------------------------------------------------------------
** And data from the pair of sorbent traps are also invalidated.

* * * * *

9.2 Gas Flow Meter Calibration

    9.2.1 Preliminaries. The manufacturer or supplier of the gas
flow meter should perform all necessary set-up, testing,
programming, etc., and should provide the end user with any
necessary instructions, to ensure that the meter will give an
accurate readout of dry gas volume in standard cubic meters for the
particular field application.
    9.2.2 Initial Calibration. Prior to its initial use, a
calibration of the flow meter shall be performed. The initial
calibration may be done by the manufacturer, by the equipment
supplier, or by the end user. If the flow meter is volumetric in
nature (e.g., a dry gas meter), the manufacturer, equipment
supplier, or end user may perform a direct volumetric calibration
using any gas. For a mass flow meter, the manufacturer, equipment
supplier, or end user may calibrate the meter using a bottled gas
mixture containing 12  0.5% CO2, 7  0.5% O2, and balance N2, or these

same gases in proportions more representative of the expected stack
gas composition. Mass flow meters may also be initially calibrated
on-site, using actual stack gas.
    <IP_ADDRESS> Initial Calibration Procedures. Determine an average
calibration factor (Y) for the gas flow meter, by calibrating it at
three sample flow rate settings covering the range of sample flow
rates at which the sorbent trap monitoring system typically
operates. You may either follow the procedures in section 10.3.1 of
Method 5 in appendix A-3 to part 60 of this chapter or the
procedures in section 16 of Method 5 in appendix A-3 to part 60 of
this chapter. If a dry gas meter is being calibrated, use at least
five revolutions of the meter at each flow rate.
    <IP_ADDRESS> Alternative Initial Calibration Procedures.
Alternatively, you may perform the initial calibration of the gas
flow meter using a reference gas flow meter (RGFM). The RGFM may
either be: (1) A wet test meter calibrated according to section
10.3.1 of Method 5 in appendix A-3 to part 60; (2) a gas flow
metering device calibrated at multiple flow rates using the
procedures in section 16 of Method 5 in appendix A-3 to part 60; or
(3) a NIST-traceable calibration device capable of measuring
volumetric flow to an accuracy of 1 percent. To calibrate the gas
flow meter using the RGFM, proceed as follows: While the sorbent
trap monitoring system is sampling the actual stack gas or a
compressed gas mixture that simulates the stack gas composition (as
applicable), connect the RGFM to the discharge of the system. Care
should be taken to minimize the dead volume between the sample flow
meter being tested and the RGFM. Concurrently measure dry gas volume
with the RGFM and the flow meter being calibrated the for a minimum
of 10 minutes at each of three flow rates covering the typical range
of operation of the sorbent trap monitoring system. For each 10-
minute (or longer) data collection period, record the total sample
volume, in units of dry standard cubic meters (dscm), measured by
the RGFM and the gas flow meter being tested.
    <IP_ADDRESS> Initial Calibration Factor. Calculate an individual
calibration factor Yi at each tested flow rate from
section <IP_ADDRESS> or <IP_ADDRESS> of this appendix (as applicable), by
taking the ratio of the reference sample volume to the sample volume
recorded by the gas flow meter. Average the three Yi
values, to determine Y, the calibration factor for the flow meter.
Each of the three individual values of Yi must be within
0.02 of Y. Except as otherwise provided in sections
<IP_ADDRESS> and <IP_ADDRESS> of this appendix, use the average Y value from
the three level calibration to adjust all subsequent gas volume
measurements made with the gas flow meter.
    <IP_ADDRESS> Initial On-Site Calibration Check. For a mass flow meter
that was initially calibrated using a compressed gas mixture, an on-
site calibration check shall be performed before using the flow
meter to provide data for this part. While sampling stack gas, check
the calibration of the flow meter at one intermediate flow rate
typical of normal operation of the monitoring system. Follow the
basic procedures in section <IP_ADDRESS> or <IP_ADDRESS> of this appendix. If
the on-site calibration check shows that the value of Yi,
the calibration factor at the tested flow rate, differs by more than
5 percent from the value of Y obtained in the initial calibration of
the meter, repeat the full 3-level calibration of the meter using
stack gas to determine a new value of Y, and apply the new Y value
to all subsequent gas volume measurements made with the gas flow
meter.
    <IP_ADDRESS> Ongoing Quality Assurance. Recalibrate the gas flow
meter quarterly at one intermediate flow rate setting representative
of normal operation of the monitoring system. Follow the basic
procedures in section <IP_ADDRESS> or <IP_ADDRESS> of this appendix. If a
quarterly recalibration shows that the value of Yi, the
calibration factor at the tested flow rate, differs from the current
value of Y by more than 5 percent, repeat the full 3-level
calibration of the meter to determine a new value of Y, and apply
the new Y value to all subsequent gas volume measurements made with
the gas flow meter.
* * * * *

10.4 Field Sample Analysis

    Analyze the sorbent trap samples following the same procedures
that were used for conducting the spike recovery study. The three
sections of each sorbent trap must be analyzed separately (i.e.,
section 1, then section 2, then section 3). Quantify the total mass
of Hg for each section based on analytical system response and the
calibration curve from section 10.1 of this appendix. Determine the
spike recovery from sorbent trap section 3. The spike recovery must
be no less than 75 percent and no greater than 125 percent. To
report the final Hg mass for each trap, add together the Hg masses
collected in trap sections 1 and 2.
* * * * *

11.5 [Reserved]

11.6 Calculation of Hg Concentration

    Calculate the Hg concentration for each sorbent trap, using the
following equation:
[GRAPHIC] [TIFF OMITTED] TR07SE07.036

Where:

C = Concentration of Hg for the collection period, ([mu]gm/dscm)
M\*\ = Total mass of Hg recovered from sections 1 and 2 of the
sorbent trap, ([mu]g)
Vt = Total volume of dry gas metered during the
collection period, (dscm). For the purposes of this appendix,
standard temperature and pressure are defined as 20 [deg]C and 760
mm Hg, respectively.

11.7 Calculation of Paired Trap Agreeement

    Calculate the relative deviation (RD) between the Hg
concentrations measured with the paired sorbent traps:
[GRAPHIC] [TIFF OMITTED] TR07SE07.037

Where:

RD = Relative deviation between the Hg concentrations from traps
``a'' and ``b'' (percent)
Ca = Concentration of Hg for the collection period, for
sorbent trap ``a'' ([mu]gm/dscm)
Cb = Concentration of Hg for the collection period, for
sorbent trap ``b'' ([mu]gm/dscm)
* * * * *
[FR Doc. 07-4147 Filed 9-6-07; 8:45 am]

BILLING CODE 6560-50-P