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m UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
I OFFICE OF ENFORCEMENT
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I EPA-330 I 9-94-001
I SUMMARY OF NEIC LEAK DETECTION
AND REPAIR PROGRAM INVESTIGATIONS
1 ' '%,
• January 1994
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| NATIONAL ENFORCEMENT INVESTIGATIONS CENTER
• Denver, Colorado
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CONTENTS
INTRODUCTION 1
NEIC LDAR PROGRAM INVESTIGATION METHODS 3
FILE AND DOCUMENT REVIEW 3
EVALUATION 3
COMPONENT MONITORING 4
DATA EVALUATION AND INVESTIGATION REPORT 4
SUMMARY OF THE NEIC LDAR PROGRAM INVESTIGATIONS 5
APPENDIX
Reference Method 21
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Fugitive VOC emissions are regulated by 40 CFR Parts 60 and 61.
• Specific regulations and requirements for National Emission Standards for
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INTRODUCTION
The Clean Air Act requires facilities with equipment in volatile organic
compound (VOC) service to develop and implement a Leak Detection and
Repair (LDAR) program to control fugitive VOC emissions.
Hazardous Air Pollutants (NESHAP), New Source Performance Standards
(NSPS), and additional VOC components are outlined in various subparts of
40 CFR Parts 60 and 61. State and local agencies normally incorporate the
federal requirements by reference into the state and local air regulations, but
*• v •»
may have their own LDAR requirements.
NESHAP and NSPS regulations require regulated facilities with
equipment operating in VOC service to implement an LDAR program designed
• to reduce fugitive emissions. Requirements include equipment identification,
" a monitoring program, and recordkeeping and reporting. The leak monitoring
• requirements apply to all plant equipment containing 10% or greater VOC,
including pumps, valves, compressors, and flanges. VOC components
• associated with storage tanks, loading/unloading areas, and transfer lines are
also subject to monitoring requirements.
Facilities may choose to operate under alternative standards for valves
I allowing a 2.0% total valve leak rate for each unit. Component monitoring of
valves in benzene service and valves in NSPS units can be conducted annually,
I as outlined in 40 CFR § 61.112 and 40 CFR § 60.483.
NEIC conducts comprehensive LDAR program investigations, often as
part of multi-media compliance investigations, to determine compliance with
LDAR program requirements. The NEIC LDAR on-site inspections are divided
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into two parts: (1) monitoring of VOC components by NEIC personnel, and
(2) evaluating facility monitoring procedures. NEIC monitors between 2,000
EPA Reference Method 21" [Appendix]. This report provides an overview of the
NEIC LDAR program investigations.
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and 3,000 components at each inspected facility using procedures specified in
EPA Reference Method 21" [Appendix]. This report provides an overview of thi
NEIC LDAR investigation methods and summarizes the results of recent
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• * As specified in 40 CFR Part 60 Appendix A
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Quarterly VOC monitoring reports are reviewed and are used to select process
units for monitoring.
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NEIC LDAR PROGRAM INVESTIGATION METHODS
_ NEIC LDAR investigations include:
I* Review of EPA and state files and documents
• Evaluation of the facility monitoring procedures
I* On-site VOC component monitoring
• Data evaluation and report preparation
" FILE AND DOCUMENT REVIEW
• State and federal files are reviewed for information regarding facility
— *•_
• operations/equipment, permits, inspections, and any enforcement actions.
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• EVALUATION
• NEIC evaluates fugitive VOC monitoring procedures used by facilities
or facility contractors. The evaluation includes:
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* Determination of facility processes involving VOCs through
I discussions with facility personnel, including a detailed process
description
I • Review of facility/contractor monitoring procedures, including
equipment calibration
J • Review of VOC component inventory, leak logs, repair logs,
emission reports
| • Identification of specific components in VOC service
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COMPONENT MONITORING
NEIC monitors a representative number of components in VOC service
from process units, storage tanks, loading/unloading areas, transfer lines, and
ancillary equipment using an organic vapor analyzer. Components monitored
are selected using various criteria including:
. • Equipment subject to NSPS and NESHAP requirements
• Past monitoring results .
• Presence of "special" types of VOC equipment, such as railroad
car and truck loading racks
• Type of VOC in service
DATA EVALUATION AND INVESTIGATION REPORT
Upon completion of the on-site inspection, NEIC evaluates the
information/data obtained. This includes data collected during component
monitoring to determine equipment leak rates. Leak rates determined by
NEIC are compared to leak rates reported by the facility. An investigation
report is then prepared and provided to Regional personnel.
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SUMMARY OF THE NEIC LDAR PROGRAM INVESTIGATIONS
None of the facility LDAR programs evaluated by NEIC were in full
compliance with regulatory requirements. Although the facilities inspected
were located in various states and regions, the common deficiencies outlined
below were identified. These deficiencies have most likely resulted in greater
uncontrolled VOC emissions.
* VOC component leak rates determined by NEIC are greater than the
leak rates reported by the majority of facilities for each process unit
inspected. NEIC leak rates and facility reported leak rates for several
process units are summarized below:
Facility Reported Percent Leak Rate
2.7
1.6
3.5
0.73
1.6
4.0
1.3
0.72
1.7
4.1
0.8
0.8
0.4
4.4
NEIC Determined Percent Leak Rate
18.7
6.1
15.4
8.4
6.7
13.0
6.9
5.4
6.3
13.0
6.1
7.7
7.2
2.9
Several process units monitored by NEIC were operating under the
alternative standards for valves allowing a 2.0% valve leak rate for each
unit. This allows facilities to monitor valves in benzene service and
valves in NSPS units annually rather than quarterly. Facilities
operating under this standard and monitored by NEIC exceeded the 2%
allowable percentage of valves leaking.
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_ . • Inaccurate/incomplete VOC component inventories
_ - Many regulated components are not identified/tagged for
I inclusion into the monitoring program
I Equipment monitored not in VOC service (i.e. hot water, caustic,
and steam lines)
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Incorrect/inconsistent monitoring procedures
I - Components in VOC service are not monitored
Inadequate monitoring equipment calibration procedures
I - Method 21 procedures not followed
• NEIC also identified inconsistencies within local LDAR regulations and
deficiencies between local and federal regulations. Conflicting requirements
• within particular local regulations caused ambiguity in determining the
number of leaking components at some facilities.
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NEIC identified other sources of fugitive VOC emissions not subject to
J LDAE requirements. For example, gasket seals on rotary filters, not included
in LDAR requirements, were found to be leaking VOCs at concentrations in
| excess of 10,000 parts per million.
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• APPENDIX
• REFERENCE METHOD 21
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PI. 60, App. A, Meth. 21
be on a dry basis. Calculate the pollutant
emission rate, as follows:
20.9
E=C«Fd 209_
Eq. 20-6
where:
E = Mass emission rate of pollutant. ng/J
(lb/10« Btu).
7.5.2 Calculation of Emission Rate Using
Carbon Dioxide Correction. The COj con-
centration and the pollutant concentration
may be on either a dry basis or a wet basis,
but both concentrations must be on the
same basis for the calculations. Calculate
the pollutant emission rate using Equation
20-7 or 20-8:
E=C«FC
E=C.FC
100
%CO,
100
%co»w
Eq. 2(1-7
Eq. 20-8
where:
Cw=Pollutant concentration measured on a
moist sample basis, ng/sm3 (Ib/scf).
%COJw=Measured CO, concentration meas-
ured on a moist sample basis, percent.
8. Bibliography
1. Curtis, P. A Method for Analyzing NO.
Cylinder Gases-Specific Ion Electrode Pro-
cedure, Monograph available from Emission
Measurement Laboratory, ESED, Research
Triangle Park. NC 27711, October 1978.
2. Sigsby, John E.. P. M. Black, T. A.
Bellar, and D. L Klosterman. Chemilu-
minescent Method for Analysis of Nitrogen
Compounds in Mobile Source Emissions
(NO, NOi, and NHa ). "Environmental Sci-
ence and Technology." 7:51-54. January
1973.
3. Shigehara. R.T., R.M. Neulicht, and
W.S. Smith. Validating Orsat Analysis Data
from Possil Fuel-Fired Units. Emission
Measurement Branch, Emission Standards
and Engineering Division, Office of Air
Quality Planning and Standards, U.S. Envi-
ronmental Protection Agency, Research Tri-
angle Park. NC 27711. June 1975.
METHOD 21—DETERMINATION or VOLATILE
ORGANIC COMPOUNDS LEAKS
1. Applicability and Principle
40 CFR Ch. I (7-L92 Edition)
1.1 Applicability. This method applies to
the determination of volatile organic com-
pound (VOC) leaks from process equipment.
These sources include, but are not limited
to. valves, flanges and other connections.
pumps and compressors, pressure relief de-
vices, process drains, open-ended valves,
pump and compressor seal system degassing
vents, accumulator vessel vents, agitator
seals, and access door seals.
1.2 Principle. A portable instrument is
used to detect VOC leaks from individual
sources. The instrument detector type is not
specified, but it must meet the specifica-
tions and performance criteria contained in
Section 3. A leak definition concentration
based on a reference compound is specified
in each applicable regulation. This proce-
dure is intended to locate and classify leaks
only, and is not to be used as a direct meas-
ure of mass emission rates from individual
sources.
2. Definitions
2.1 Leak Definition-Concentration. The
local VOC concentration at the surface of a
leak source that indicates that a VOC emis-
sion (leak) is present. The leak definition is
an instrument meter reading based on a ref-
erence compound.
2.2 Reference Compound. The VOC spe-
cies selected as an instrument calibration
basis for specification of the leak definition
concentration. (For example: If a leak defi-
nition concentration is 10,000 ppmv as
methane, then any source emission that re-
sults in a local concentration that yields a
meter reading of 10.000 on an instrument
calibrated with methane would be classified
as a leak. In this example, the leak defini-
tion is 10,000 ppmv, and the reference com-
pound is methane.)
2.3 Calibration Gas. The VOC compound
used to adjust the instrument meter reading
to a known value. The calibration gas is usu-
ally the reference compound at a concentra-
tion approximately equal to the leak defini-
tion concentration.
2.4 No Detectable Emission. Any VOC
concentration at a potential leak source (ad-
justed for local VOC ambient concentra-
tion) that is less than a value corresponding
to the instrument readability specification
of section 3.1.1(c) indicates that a leak is not
present.
2.5 Response Factor. The ratio of the
known concentration of a VOC compound
to the observed meter reading when meas-
ured using an instrument calibrated with
the reference compound specified in the ap-
plication regulation.
2.6 Calibration Precision. The degree of
agreement between measurements of the
same known value, expressed as the relative
percentage of the average difference be-
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Environmental Protection Agency
tween the meter readings and the known
concentration to the known concentration.
2.7 Response Time! The time interval
from a step change in VOC concentration at
the input of the sampling system to the
time at which 90 percent of the correspond-
ing final value is reached as displayed on
the instrument readout meter.
3. Apparatus
3.1 Monitoring Instrument.
3.1.1 Specifications.
a. The VOC instrument detector shall re-
spond to the compounds being processed.
Detector types which may meet this re-
quirement include, but are not limited to,
catalytic oxidation, flame ionization, infra-
red absorption, and photoionization.
b. Both the linear response range and the
measurable range of the instrument for
each of the VOC to be measured, and for
the VOC calibration gas that is used for
calibration, shall encompass the leak defini-
tion concentration specified in the regula-
tion. A dilution probe assembly may beJUsed
to bring the VOC concentration within both
ranges; however, the specifications for in-
strument response time and sample probe
diameter shall still be met.
c. The scale of the instrument meter shall
be readable to ±2.5 percent of the specified
leak definition concentration when perform-
ing a no detectable emission survey.
d. The instrument shall be equipped with
an electrically driven pump to insure that a
sample is provided to the detector at a con-
stant flow rate. The nominal sample flow
rate, as measured at the sample probe tip,
shall be 0.10 to 3.0 liters per minute when
the probe is fitted with a glass wool plug or
filter that may be used to prevent plugging
of the instrument.
e. The instrument shall be intrinsically
safe as defined by the applicable U.S.A.
standards (e.g.. National Electric Code by
the National Fire Prevention Association)
for operation in any explosive atmospheres
that may be encountered in its use. The in-
strument shall, at a minimum, be intrinsi-
cally safe for Class 1, Division 1 conditions,
and Class 2. Division 1 conditions, as defined
by the example Code. The instrument shall
not be operated with any safety device, such
as an exhaust flame arrester, removed.
f. The instrument shall be equipped with
a probe or probe extension for sampling not
to exceed V* in. in outside diameter, with a
single end opening for admission of sample.
3.1.2 Performance Criteria.
(a) The instrument response factors for
each of the VOC to be measured shall be
less than 10. When no instrument is avail-
able that meets this specification when cali-
brated with the reference VOC specified in
the applicable regulation, the available in-
strument may be calibrated with one of the
VOC to be measured, or any other VOC, so
Pt. 60, App. A, Meth. 21
long as the instrument then has a response
factor of less than 10 for each of the VOC
to be measured.
(b) The instrument response time shall be
equal to or less than 30 seconds. The instru-
ment pump, dilution probe (if any), sample
probe, and probe filter, that will be used
during testing, shall all be in place during
the response time determination.
c. The calibration precision must be equal
to or less than 10 percent of the calibration
gas value.
d. The evaluation procedure for each pa-
rameter is given in Section 4.4.
3.1.3 Performance Evaluation Require-
ments.
a. A response factor must be determined
for each compound that is to be measured,
either by testing or from reference sources.
The response factor tests are required
before placing the analyzer into service, but
do not have to be repeated at subsequent in-
tervals.
b. The calibration precision test must be
completed prior to placing the analyzer into
service, and at subsequent 3-month intervals
or at the next use whichever is later.
c. The response time test is required prior
to placing the instrument into service. If a
modification to the sample pumping system
or flow configuration is made that would
change the response time, a new test is re-
quired prior to further use.
3.2 Calibration Gases. The monitoring in-
strument is calibrated in terms of parts per
million by volume (ppmv) of the reference
compound specified in the applicable regu-
lation. The calibration gases required for
monitoring and instrument performance
evaluation are a zero gas (air, less than 10
ppmv VOC) and a calibration gas in air mix-
ture approximately equal to the leak defini-
tion specified in the regulation. If cylinder
calibration gas mixtures are used, they must
be analyzed and certified by the manufac-
turer to be within ±2 percent accuracy, and
a shelf life must be specified. Cylinder
standards must be either reanalyzed or re-
placed at the end of the specified shelf life.
Alternately, calibration gases may be pre-
pared by the user according to any accepted
gaseous standards preparation procedure
that will yield a mixture accurate to within
±2 percent. Prepared standards must be re-
placed each day of use unless it can be dem-
onstrated that degradation does not occur
during storage.
Calibrations may be performed using a
compound other than the reference com-
pound if a conversion factor is determined
for that alternative compound so that the
resulting meter readings during source sur-
veys can be converted to reference com-
pound results.
4. Procedures"
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Pt. 60, App. A, Meth. 21
4.1 Pretest Preparations. Perform the in-
strument evaluation procedures given in
Section 4.4 if the evaluation requirements
of Section 3.1.3 have not been met.
4.2 Calibration Procedures. Assemble and
start up the VOC analyzer according to the
manufacturer's instructions. After the ap-
propriate warmup period and zero internal
calibration procedure, introduce the calibra-
tion gas into the instrument sample probe.
Adjust the instrument meter readout to cor-
respond to the calibration gas value.
NOTE: If the meter readout cannot be ad-
justed to the proper value, a malfunction of
the analyzer is indicated and corrective ac-
tions are necessary before use.
4.3 Individual Source Surveys.
4.3.1 Type I—Leak Definition Based on
Concentration. Place the probe inlet at the
surface of the component interface where
leakage could occur. Move the probe along
the interface periphery while observing the
instrument readout. If an increased meter
reading is observed, slowly sample the inter^
face where leakage is indicated until the
maximum meter reading is obtained. Leave
the probe inlet at this maximum reading lo-
cation for approximately two times the in-
strument response time. If the maximum
observed meter reading is greater than the
leak definition in the applicable regulation,
record and report the results as specified in
the regulation reporting requirements. Ex-
amples of the application of this general
technique to specific equipment types are:
a. Valves—The most common source of
leaks from valves is at the seal between the
stem and housing. Place the probe at the
interface where the stem exits the packing
gland and sample the stem circumference.
Also, place the probe at the interface of the
packing gland take-up flange seat and
sample the periphery. In addition, survey
valve housings of multipart assembly at the
surface of all interfaces where a leak could
occur.
b. Flanges and Other Connections—For
welded flanges, place the probe at the outer
edge of the flange-gasket interface and
sample the circumference of the flange.
Sample other types of nonpermanent joints
(such as threaded connections) with a simi-
lar traverse.
c. Pumps and Compressors—Conduct a cir-
cumferential traverse at the outer surface
of the pump or compressor shaft and seal
interface. If the source is a rotating shaft.
position the probe inlet within 1 cm of the
shaft-seal interface for the survey. If the
housing configuration prevents a complete
traverse of the shaft periphery, sample all
accessible portions. Sample all other joints
on the pump or compressor housing where
leakage could occur.
d. Pressure Relief Devices—The configura-
tion of most pressure relief devices prevents
40 CFR Ch. I (7.1-92 Edition)
sampling at the sealing seat interface. For
those devices equipped with an enclosed ex-
tension, or horn, place the probe inlet at ap-
proximately the center of the exhaust area
to the atmosphere.
e. Process Drains—For open drains, place
the probe inlet at approximately the center
of the area open to the atmosphere. For
covered drains, place the probe at the sur-
face of the cover interface and conduct a pe-
ripheral traverse.
f. Open-Ended Lines or Valves—Place the
probe inlet at approximately the center of
the opening to the atmosphere.
g. Seal System Degassing Vents and Accu-
mulator Vents—Place the probe inlet at ap-
proximately the center of the opening to
the atmosphere.
h. Access Door Seals—Place the probe
inlet at the surface of the door seal inter-
face and conduct a peripheral traverse.
4.3.2 Type II—"No Detectable Emission".
Determine the local ambient concentra-
tion around the source by moving the probe
inlet randomly upwind and downwind at a
distance of one to two meters from the
source. If an interference exists with this
determination due to a nearby emission or
leak, the local ambient concentration may
be determined at distances closer to the
source, but in no case shall the distance be
less than 25 centimeters. Then move the
probe inlet to the surface of the source and
determine the concentration described in
4.3.1. The difference between these concen-
trations determines whether there are no
detectable emissions. Record and report the
results as specified by the regulation.
For those cases where the regulation re-
quires a specific device installation, or that
specified vents be ducted or piped to a con-
trol device, the existence of these conditions
shall be visually confirmed. When the regu-
lation also requires that no detectable emis-
sions exist, visual observations and sampling
surveys are required. Examples of this tech-
nique are:
(a) Pump or Compressor Seals—If applica-
ble, determine the type of shaft seal. Pre-
form a survey of the local area ambient
VOC concentration and determine if detect-
able emissions exist as described above.
(b) Seal System Degassing Vents, Accumu-
lator Vessel Vents, Pressure Relief Devices—
If applicable, observe whether or not the ap-
plicable ducting or piping exists. Also, deter-
mine if any sources exist in the ducting or
piping where emissions could occur prior to
the control device. If the required ducting
or piping exists and there are no sources
where the emissions could be vented to the
atmosphere prior to the control device, then
it is presumed that no detectable emissions
are present. If there are sources in the duct-
ing or piping where emissions could be
vented or sources where leaks could occur,
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the sampling surveys described in this para-
graph shall be used to determine if detecta-
ble emissions exist.
4.3.3 Alternative Screening Procedure. A
screening procedure based on the formation
of bubbles in a soap solution that is sprayed
on a potential leak source may be used for
those sources that do not have continuously
moving parts, that do not have surface tem-
peratures greater than the boiling point or
less than the freezing point of the soap solu-
tion, that do not have open areas to the at-
mosphere that the soap solution cannot
bridge, or that do not exhibit evidence of
liquid leakage. Sources that have these con-
ditions present must be surveyed using the
instrument techniques of 4.3.1 or 4.3.2.
Spray a soap solution over all potential
leak sources. The soap solution may be a
commercially available leak detection solu-
tion or may be prepared using concentrated
detergent and water. A pressure sprayer or
a squeeze bottle may be used to dispense the
solution. Observe the potential leak sites-to
determine if any bubbles are formed. If no
bubbles are observed, the source is pre-
sumed to have no detectable emissions or
leaks as applicable. If any bubbles are ob-
served, the instrument techniques of 4.3.1 or
4.3.2 shall be used to determine if a leak
exists, or if the source has detectable emis-
sions, as applicable.
4.4 Instrument Evaluation Procedures. At
the beginning of the instrument perform-
ance evaluation test, assemble and start up
the instrument according to the manufac-
turer's instructions for recommended
warmup period and preliminary adjust-
ments.
4.4.1 Response Factor. Calibrate the in-
strument with the reference compound as
specified in the applicable regulation. For
each organic species that is to be measured
during individual source surveys, obtain or
prepare a known standard in air at a con-
centration of approximately 80 percent of
the applicable leak definition unless limited
by volatility or explosivity. In these cases,
prepare a standard at 90 percent of the
saturation concentration, or 70 percent of
the lower explosive limit, respectively. In-
troduce this mixture to the analyzer and
record the observed meter reading. Intro-
duce zero air until a stable reading is ob-
tained. Make a total of three measurements
by alternating between the known mixture
and zero air. Calculate the response factor
for each repetition and the average re-
sponse factor.
Alternatively, if response factors have
been published for the compounds of inter-
est for the instrument or detector type, the
response factor determination is not re-
quired, and existing results may be refer-
enced. Examples of published response fac-
tors for flame ionization and catalytic oxi-
Pt, 60, App. A, Meth. 22
dation detectors are included in Bibliogra-
phy.
4.4.2 Calibration Precision. Make a total
of three measurements by alternately using
zero gas and the specified calibration gas.
Record the meter readings. Calculate the
average algebraic difference between the
meter readings and the known value. Divide
this average difference by the known cali-
bration value and mutiply by 100 to express
the resulting calibration precision as a per-
centage.
4.4.3 Response Time. Introduce zero gas
into the instrument sample probe. When
the meter reading has stabilized, switch
quickly to the specified calibration gas.
Measure the time from switching to when
90 percent of the final stable reading is at-
tained. Perform this test sequence three
times and record the results. Calculate the
average response time.
5. Bibliography
1. DuBose. D.A., and G.E. Harris. Re-
sponse Factors of VOG -Analyzers at a Meter
Reading of 10,000 ppmv for Selected Organ-
ic Compounds. U.S. Environmental Protec-
tion Agency, Research Triangle Park, NC.
Publication No. EPA 600/2-81-051. Septem-
ber 1981.
2. Brown. G.E., et al. Response Factors
of VOC Analyzers Calibrated with Methane
for Selected Organic Compounds. U.S. Envi-
ronmental Protection Agency, Research Tri-
angle Park, NC. Publication No. EPA 600/2-
81-022. May 1981.
3. DuBose, D.A., et al. Response of Porta-
ble VOC Analyzers to Chemical Mixtures.
U.S. Environmental Protection Agency, Re-
search Triangle Park. NC. Publication No.
EPA 600/2-81-110. September 1981.
METHOD 22—VISUAL DETERMINATION or FU-
GITIVE EMISSIONS FROM MATERIAL
SOURCES AND SMOKE EMISSIONS FROM
FLARES
1. Introduction
This method involves the visual determi-
nation of fugitive emissions, i.e., emissions
not emitted directly from a process stack or
duct. Fugitive emissions include emissions
that (1) escape capture by process equip-
ment exhaust hoods; (2) are emitted during
material transfer; (3) are emitted from
buildings housing material processing or
handling equipment; and (4) are emitted di-
rectly from process equipment. This method
is used also to determine visible smoke emis-
sions from flares used for combustion of
waste process materials.
This method determines the amount of
time that any visible emissions occur during
the observation period, i.e.. the accumulated
emission time. This method does not require
that the opacity of emissions be determined.
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