United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park, NC
EPA 340/1-92-004
December 1993
Final Draft
Stationary Source Compliance Training Series
EPA VISIBLE EMISSIONS
FIELD MANUAL
EPA Methods 9 and 22
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EPA 340/1-92-004
December 1993
Visible Emissions Field Manual
EPA Methods 9 and 22
Prepared by:
Eastern Technical Associates
PO Box 58495
Raleigh, NC 27658
and
Entrophy Environmentalist, Inc.
PO Box 12291
Research Triangle Park, NC 27709
Contract No. 68-02-4462
Work Assignment No. 91-188
EPA Work Assignment Managers: Karen Randolph and Kirk Foster
EPA Project Officer: Aaron Martin
US. ENVIRONMENTAL PROTECTION AGENCY
Stationary Source Compliance Division
Office of Air Quality Planning and Standards
Washington, DC 20460
December 1993
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Contents
Introd ucti on .... .............................. [[[ ................... 2
A Brief History of Opacity. [[[3
o paci t y M ea.surement Princi pi es .......................................... .............................................. ......... 4
Records Revi ew ................... ................ ................ .............................................. .... ........ .... ............. 8
Eq ui p men t ... [[[ ........................................ ............ ................. 9
Fi el d 0 perati ons ............. .................. .................... .................. ...... .... ............................ ............... 11
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Introduction
The Federal opacity standards for various indusnies are
found in 40CFR Pan 60 (Standards of Perfonnance for
New and Modified Stationary Soun:.es) and 40 CPR Pan
61 and 62 (Emission Standards for Hazardous Air Pol-
lutants). These standards require the use of Reference
Method 9 or Reference Method 22, contained in Appen-
dix A of Pan 60, for the detennina1ion of the level or
frequency of visible emissions by trained observers.
In addition to the plume observation procedures, Method
9 also contains data reduction and reporting procedures
as well as procedures and specifications for ttaining and
certifying qualified visible emission (VB) observers.
State Implementation Plans (SIPs) also typically include
several types of opacity regulations, which in some cases
may differ from the federal opacity standards in tenns of
the opacity limits, the measurement method or test pr0-
cedure. or the data evaluation technique. For example,
some SIP opacity rules limit visible emissions to a speci-
fied number of minutes per hour or other time period
(time exemption); some limit opacity to a cenain level
averaged over a specified number of minutes (time aver-
aged); some set opacity. limits where no single reading
can exceed the standard (instantanous or "cap"). Re-
gardless of the exact fonnat of the SIP opacity reguJa-
tions. nearly all use the procedures in Method 9 for
conducting' VE field observations and for training and
certifying VE observers. The observation procedures con-
tain instructions on how to read the plume and record
the values, including where to stand to observe the plume
and what infonnation must be gathered to suppon the
visible emission detenninations. The validity of the VE
determinations used for compliance or noncompliance
demonstration purposes depends to a grea1 extent on how
well the field observations are documented on the VE
Observation Fonn. This field manual will stress the type
and extent of documentation needed to satisfy Method 9
requirements.
Federal opacity standards and most SIP opacity reguJa-
tions are independently enforceable, i.e., a source may be
cited for an opacity violation even when it is in compli-
ance with the particulate mass standard. Thus, visible
emission observations by qualified agency observers serve
2
as a primary compliance surveillance tool for enforce-
ment of emission conttol standards. In addition, many
federal and SIP reguIations and construction and 0pera1-
ing permits also require owners/operatorS of affected fa-
cilities to assess and repon opacity data during the initial
compliance tests and at specified intervals over the long
tenn.
-
Regulated soun:es may be subject to stiff penalties for
failure to comply with federal and state emission stan-
dards, including opacity standards. Civil and adminis-
trative penalties of up to $25,000 per day per violation
can be assessed under the Clean Air Act (CAA). States
and local agencies are encouraged under Title V of the
CM to have program authority to levy fines up to $10,000
per day per violation. Therefore, visible emission deter-
minations for compliance demonstration or enforcement
purposes must be made accUrately and must be suffi-
ciently well documented to withstand rigorous examina-
tion in potential enforcement proceedings, administrative
or legal hearings, or eventual coon litigation.
. Procedural errors or omissions on the visible emission
evaluation fonns or data sheets can invalidate the data or
otherwise provide a basis for questioning the evaluation.
Only by carefully following the procedures set forth in
Method 9 (or any other reference method) and by paying
close anention to proper completion of the VE Observa-
tion Fonn can you be assured of acceptance of the evalu-
ation data.
The purpose of this simplified manual is to present a
step-by-step field guide for inexperienced VE observers
who have recently completed the VE training and certifi-
cation tests on how to conduct VE observations in accor-
dance with the published opacity methods. The basic
steps of a well-planned and properly perfonned VE in-
spection are illustra1ed in the inspection flow chan (see
Figure 1). This manual is organized to follow the inspec-
tion flow chan. Sections of the reference methods that
must be carefully observed or followed during the. in-
spection are highlighted. Method 9 and Method 22 are
reprinted in full in Appendix B and Appendix. C respec-
tively. A recommended field VB Observation Fom, in-
cluded in Appendix A, may be copied or modified for
field use.
It should be noted that much of the infonnation pre-
sented in this simplified field manual has been derived
from a number of previously published technical guides,
manuals, and reports on Method 9 and related opacity
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Figure 1. VE Inspection Flow Chart
methods. For more detailed information on Method 9
and the application of Method 9. please consult the list
of publications at the end of this manual.
A Brief History Of Opacity
Early History
The first smoke. evaluation system evolved from a con-
cept developed by Maximillian RingeImann in the late
1800s. Ringelmann realized that black smoke from coal-
fued boilers was the result of poor combustion efficiency. .
Darker smoke meant poorer efficiency. and to measure
the darkness of the smoke. RingeImann devised a chart
with four different black grids on a white background. At
a distance of at least 50 feet. the grids on the chart
appear as shades of gray. By matching the shade of a
smoke plume with the apparem shade of a grid on the
chart. Ringebnann was able to classify emissions. With
this information, he could adjust the fuel-to-air ratio of a
furnace to increase efficiency and decrease the smoke.
The Ringelmann Chart was adopted and promoted by the
U.S. Bureau of Mines in the early 1900s in their efforts
to improve coal combustion practices. It bas been used
extensively ever since by industry and control agencies to
assess and control emissions.
FUEL/AIR MIXTURE RATIO
EXCESS AIR OPTIMUM
HEAT lOSS COMBUsnON
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OPTIMUM OXYGEN EXCESS
AND OPACITY OPACITY
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RingelmAnn Chart
Ringelmann Period
By 1910. many larger municipalities had adopted the
Ringebnann Chart into their health and safety regula-
tions in an attempt to control smoke as a nuisance. To
prove a violation of a nuisance code. it was necessary to
prove that:
. The smoke was dense
. The smoke was a nuisance
Betw~ -1914 and the 19405. the coons recognized that
smoke could be regulated under the police power of the
state. and a regulatory agency no longer had to prove
that the smoke was a nuisance. The U.S. Surgeon Gen-
eral declared that smoke and other air pollutants were
not only a nuisance but a health hazard in 1948 after a
series of air-pollution-related deaths in Donora, Pennsyl-
vania. This set the stage for federal regulations and the
control of air pollution to protect the public health.
3
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Equivalent Opacity
In the 1950s and 1960s Los Angeles added two major
refinements to the use of visible emissions as a tool for
controlling paniculate emissions. The Ringelmann method
was expanded to white and other colors of smoke by the
introduction of "equivalent opacity." Equivalent opacity
meant that the white smoke was equivalent to a
Ringelmann number in its ability to obscure the view of
a background. In some states, equivalent opacity is still
measured in Ringelmann numbers, whereas in others the
0-to 100-percent scale is used. Also, by training and cer-
tifying inspectors using a smoke generator equipped with
an opacity meter, regulatory agencies ensured that certi-
fied inspectors did not have to carry and use Ringelmann
cards.
In 1968, the Federal Air Pollution Control Office pub-
lished AP-30, Optical Properties and Visual Effects of
Smoke-Stack Plumes, describing the accuracy of a smoke
reader's observations compared to a transmissometer. AP-
30 also discussed the effect on opacity observations when
a plume is viewed with the sun in the wrong place rela-
tive to the source.
Method 9
The Environmental Protection Agency (EPA) stopped us-
ing Ringelmann numbers in the New Source Performance
Standards when the revised EPA Method 9 was promul-
gated in 1974. All NSPS visible emission limits are
stated in percent opacity units. Although some state
regulations (notably California's) still specify the use of
the Ringelmann system for black and gray plumes, the
national trend is to read all emissions in percent opacity.
EPA conducted extensive field studies on the accuracy
and reliability of the Method 9 opacity evaluation tech-
nique when the method was revised and repromulgated
in response to industry challenges concerning certain
NSPS opacity standards and methods. The studies showed
that visible emissions can be assessed accurately by prop-
erly trained and certified observers. Two central features
of Method 9 involve taking opacity readings of plumes at
15-second intervals and averaging 24 consecutive read-
ings (6 minutes) unless some other time period is speci-
fied in the emission standard (some NSPS specify a
3-minute averaging period).
Plume opacity emission standards and requirements re-
main the mainstay of federal, state, and local enforce-
ment efforts. Today, more visible emission observers are
certified annually than at any time in the past. This
certification rate will continue to increase with the in-
crease of federal and state regulations on industrial pro-
cesses and combustion sources such as municipal, medical.
and hazardous waste incinerators. Visible emissions stan-
dards are also applied extensively in controlling fugitive
emissions from both industrial processes and non-pro-
cess dust sources such as roads and bulk materials stor-
age and handling areas. Often there are no convenient
accurate stack testing methods for measurement of emis-
sions from unconfined sources other than opacity meth-
ods.
METHOD 22 IS A QUAIJTAITVE TECH-
NJQW CONCERNED ONLV WjTfTTHB
PRESENCE OR ABSENCE OF AN EMTS-
SION <* _ . ' - . ^J < ^
Method 22
Since EPA promulgated Method 22 in 1982, it has be-
come an important tool in the control of visible emis-
sions. Method 22 is a qualitative technique that checks
only the presence or absence of visible emissions. Method
22 or a similar method is often used in the regulation of
fugitive emissions of toxic materials. Unlike with Method
9, Method 22 users don't have to be certified. However,
a knowledge of observation techniques is essential for
correct use of the method. Therefore, Method 22 re-
quires the observer to be trained by attending the lecture
and field practice session of the Method 9 smoke school.
Opacity Measurement
Principles
The relationships between light transmittance, plume
opacity, and Ringelmann numbers are presented in Table
1.
Ringelrnarwv Opacity Trqnsmtttance
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Table 1. Comparison of Ringelmann Number, Plume
Opacity, and Light Transmittance
A literal definition of plume opacity is the degree to
which the transmission of light is reduced or the degree
to which the visibility of a background as viewed through
the diameter of a plume is reduced. In simpler terms,
opacity is the obscuring power of the plume, expressed in
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percent. In physical terms, opacity is dependent upon
transmittance (I/I,) through the plume, where I. is the
incident light flux and I is the light flux leaving the
plume along the same light path. Percent opacity can be
calculated using the following equation:
Percent opacity = (1-17(1,) x 100.
Variables Influencing Opacity
Observations
Method 9 advises:
The appearance of a plume as viewed by an observer
depends upon a number of variables, some of which
might be controllable and some of which might not
be controllable in the field.
The factors that influence plume opacity readings in-
clude particle density, particle refractive index, par-
ticle size distribution, particle color, plume
background, pathlength, distance and relative eleva-
tion to stack exit, sun angle, and lighting conditions.
Particle size is particularly significant; particles decrease
light transmission by both scattering and direct absorp-
tion. Particles with diameters approximately equal to the
wavelength of visible light (0.4 to 0.7 uni) have the great-
est scattering effect and cause the highest opacity. For a
given mass emission rate, smaller particles will cause a
higher opacity effect than larger particles. You should
note that particles in the. size range of 0.5 ftm to 8 ftm
which typically cause most of the plume opacity, are also
in the respirable range and are designated as PMIO par-
ticles.
Variables that might be controllable in the field are lu-
minous contrast and color contrast between the plume
and the background against which the plume is viewed.
These variables exert an influence on the appearance of a
plume and can affect an observer's ability to assign opac-
ity values accurately. For example, when either contrast
is high, the effect of the plume on the background is
more evident and opacity values can be assigned with
greater accuracy. When both contrasts are low, such as
in the case of a gray plume on an overcast cloudy day,
the effect is low and negative errors will occur. A nega-
tive error is when the observer under-estimates the true
opacity of the plume.
An example of high luminous contrast is a black plume
against a light sky. Two objects of the same color could
show up against each other because of differences in
lighting levels or light direction. This effect is particu-
larly important when the sun is behind a plume, thereby
making the plume more luminous than the background
and creating a high bias (positive error) in opacity read-
ings. On the other hand, when the sun is properly
oriented in relation to the plume and the plume color is
identical with the background color, observers will gen-
erally have difficulty distinguishing between the plume
and the background.
The line-of-sight pathlength through the plume is of par-
ticular concern. Method 9 states:
...the observer shall, as much as possible, make his ob-
servations from a position such that his line of vision is
approximately perpendicular to the plume direction, and
when observing opacity of emissions from rectangular
outlets (e.g., roof monitors, open baghouses, noncircular
stacks), approximately perpendicular to the longer axis
of the outlet
If the line of sight varies more than 18* from the perpen-
dicular, a positive error greater than 1 percent occurs. As
the angle increases, the error increases. When observing
plumes from conventional sources, observers should stand
at least three stack distances away from a vertically ris-
ing plume to meet this requirement. When observing
plumes from fugitive sources, which are rarely perfectly
round and are strongly affected by the wind, observers
must take care to meet this requirement.
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Measurement Error
All measurement systems have an associated error, and
Method 9 is no exception. As a result of field trials
conducted at the time Method 9 was promulgated, the
error levels at two confidence intervals for white and
black smoke using Method 9 were determined. The
method states:
For black plumes (133 sets at a smoke generator)
100 percent of the sets [average of 25 readings] were
read with a positive error of less than 7.5 percent
opacity; 99 percent were read with a positive error of
less than 5 percent opacity.
For white plumes (170 sets at a smoke generator,
168 sets at a coal-fired power plant, 298 sets at a
sulfuric acid plant), 99 percent of the sets were read
with a positive error of less than 7.5 percent opacity;
95 percent were read with a positive error of less
than 5 percent opacity.
This means that during these field trials 100 percent of
the black plumes and 99 percent of the white plumes
were not overread by more than 7.5 percent opacity. In
other words, there is only a 1-percent chance that an
observer will exceed the error on a white plume and no
chance that an observer will exceed the error on a black
plume. Negative biases due to low-contrast observation
conditions will often further offset the observational er-
ror.
Ninety-nine percent of the black plumes and 95 percent
of the white plumes were read within 5 percent opacity.
This means that an overreading occurs only about once
in 20 readings. Again, negative biases that result from
poor observation conditions flow plume-to-background
contrast) reduce the positive observational error.
Later field studies have shown slightly higher observa-
tion errors, but they are still within the 7.5-percent opac-
ity measurement error at two confidence intervals. These
studies also showed that positive error is reduced by in-
creasing the number of observations in either averaging
time or in number of averages. Both techniques improve
the accuracy of the method.
Method 22
Method 22 is used in conjunction with emission standands
or work practices in which QQ visible emissions is the
stated goal. This is frequently the case with fugitive
emission sources or sources with toxic emissions. Method
22 differs from Method 9 in that it is qualitative rather
than quantitative. Method 22 indicates only the presence
or absence of an emission rather than the opacity value.
Thus, many of the provisions of Method 9 that enhance
the accuracy of the opacity measurement are not neces-
sary in Method 22 determinations. Method 22 does not
require that the sun be the light source or that you stand
with the sun at your back. In fact, for reading asbestos
emissions regulated under NESHAP Subpart M, you are
directed to look toward the light source to improve your
ability to see the emission. Under Method 22, the dura-
tion of the emission is accurately measured using a stop-
watch. Table 2 on the following page compares major
features of Method 9 and Method 22.
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Table 2. Comparison Of Methods 9 & 22
Method 9
Method 22
Applicability
Any NSPS and SIP sources
with an opacfty standard,
such as 20 percent.
NSPS and SIP fugitive and
specified flare sources with a
'no visible emission' standard.
No opacity level can be
specified.
Measurement
The method determines the
value of the opacity
measured.
The method determines the
existence of a plume but not
the opacity.
Certification
Observer must demonstrate
the ability to measure plumes
in the field every six months.
Observer is not required to
participate in field
certification.
Lecture
Observer Is not required to
attend a lecture program.
Observer must be able to
demonstrate knowledge. A
lecture is advised, but reading
material is acceptable.
Distance From Source
No distance is specified, but
the observer must have a
clear view of the emissions.
From 15 feet to 0.25 mile.
Viewing Angle
Observer views the plume
from a position that minimizes
the line of sight through the
plume fo minimize positive
bias.
Observer simply observes the
plume.
Light Source
The sun Is Implied as the light
source and It is required to be
at the observer's back.
Light sources other than the
sun are acceptable but must
be documented. The light
must be at least 100 lux, but. It
is not required to be at the
observer's back.
Viewing Times
Momentary observation every
15 seconds for a period
determined by the standard.
Each observation is recorded.
Continuous viewing with
observer rest breaks every 15
to 20 minutes. The observer
times the emissions with a
stopwatch and records the
duration of emissions.
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Records Review
Standard Visible Emission Inspection
The standard VE observation starts with a review of the
source records on the emission point of interest. This
initial review of the records can prevent considerable
confusion and lost time in the field. You might not have
the opportunity to make the review before the inspection,
in which case the documentation should be completed
after the review. The following paragraphs describe the
items that should be checked.
The regulatory requirements and compliance status of
the emission point are critical. To use the correct mea-
surement method and the correct data-reduction tech-
nique, you must know which regulations apply.
SOURCES ARE REGULATED UNDER:
S0V . > ; ""
Compliance agreements
Permit conditions
You must determine whether the emission point is regu-
lated tinder federal New Source Performance Standards
(NSPS), the State Implementation Plan (SIP), special per-
mit conditions, or compliance order/agreement conditions.
You must check each potentially applicable regulation; if
you do not, you might use the wrong test method or
data-reduction method. You cannot rely entirely on the
Method 9 procedure in Appendix A of 40CFR Pan 60.
If the source is NSPS- regulated, special procedures or
other modifications could be included in the emission
standard for a specific source category.
SIP regulations often stipulate procedures that vary from
Method 9, even though Method 9 or a similiar method is
referenced in the SIP regulation. These variances could
be in the observation procedures, in certification require-
ments, or in the data-reduction technique. The 15-sec-
ond opacity values could be reported as time duration
(time aggregation), or as shorter or longer averages than
6 minutes, or as the number of individual values above a
"cap" (not to exceed rules). You should check the ap-
plicability of the standard to the specific process unit,
and you should also check for exempt operating condi-
tions, such as start-up, malfunction, and shut-down.
Another source of information regarding the applicable
standards as well as observation and data reduction pro-
cedures for a source is the operating permit. Special con-
ditions are often placed in the permit Also, any negoti-
ated compliance orders or agreements pertaining to the
source may contain references to opacity standards and
compliance methods or other written procedures.
Previous observations that have been made by the source,
your agency, or another agency should be reviewed Check
for photographs of the source, and make copies to take
on the evaluation to help in identifying emission points,
performing observations in a consistent manner, and
documenting changes in plant equipment.
EACH SOURCE AT A FACILITY CAN HAVE A
DIFFERENT COMPLIANCE STATUS, A DIF-
FERENT RULEyA DIFFERENT OBSERVATION
METHODOLOGY, AND A DIFFERENT DATA
REDUCTION METHOD. At£O, THE STATUS
OF A SOURCE CAN CHANGE OVER TIME.
Review any available videotape to get a feel for the site
and the emissions. VE Observation Forms from previ-
ous inspections should be evaluated to determine whether
steam plumes or other unusual conditions exist Check
inspection reports for viewing conditions or locations.
Maps and plot plans are often found in the agency source
file, which will help you in determining good observa-
tion positions and their access. Time can be saved by
using the maps and plot plans and calculating the sun's
position at different times of the day.
Emission test reports are a good source of data on the
stack height, source type, and compliance status with
other regulations such as mass emissions regulations.
Stack temperature and moisture content can be used to
determine whether a steam plume could potentially be
present on the day of your observation using the tech-
nique described in the EPA Quality Assurance Hand-
book. Volume ffl, Section 3.12.
Some emission reports have data on particle size distri-
bution. This information is useful when observing a
plume. Small particles impart a bluish haze to a plume,
because the particles scatter blue light preferentially. The
test data might reveal whether there are condensable emis-
sions in the gas stream. This information is helpful in
determining whether any residual plume is due to water
or to a complex plume reaction.
Stack test reports usually contain descriptions of control
equipment and their operating conditions. This informa-
tion is useful in determining whether there is potential
for a water condensation plume to form
8
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Lastly, fill in a sample VE Observation Form with the
data that you have collected so that you have a ready
reference when you go into the field. It is also useful to
copy a map onto the back of the field fonns you plan to
use to help locate or verify the exact observation point
Reverse Observations
Sometimes, you must make VE observations before a
formal record review. Impromptu observations are often
necessary when an opacity event is discovered. In this
case, you will not have time for an extensive pre-inspec-
tion data review. Document what you can determine
accurately in the field and complete the documentation
as soon as possible after the observation. Visible emis-
sions records used in court are treated as evidence under
the principle of past recollection recorded. This means
that you wrote it down while it was still fresh in your
mind. If you must change an entry due to new knowledge
obtained in the file review:
1. Draw a thin line through the error
WITHOUT OBLITERATING IT.
2. Write the correction above it in ink.
3. Initial and date the change.
Equipment
Method 9 does not contain any special requirements or
specifications for equipment or supplies; however, cer-
tain equipment is necessary to conduct a valid observa-
tion that will withstand the rigors of litigation. Other
equipment, though optional, can make the collection of
high-quality data easier. This section gives specifica-
tions, criteria, or design features for the recommended
basic VE equipment.
Clipboard And Accessories
You should have a clipboard, several black ballpoint pens
(medium point), several large rubber bands, and a suffi-
cient number of VE Observation Forms to document any
expected and unexpected observations. Use black ball-
point pens so that completed forms can be copied and
still remain legible over several reproduction generations.
Rubber bands hold the data form flat on the clipboard
under windy conditions and hold other papers and blank
forms on the back of the clipboard. Use observation forms
that meet EPA Method 9 requirements. Sample forms
that have been extensively field tested are provided in
Appendix A.
Timer
During a VE observation, it is necessary to time the 15-
second intervals between opacity readings. You have a
choice between using a watch or dedicated timer. The
best practice is to attach two dedicated timers to your
clipboard. Liquid-crystal-display timers are preferred be-
cause of their accuracy and readability. Use one timer to
determine the start and stop times of the observation and
the other timer to provide a continuous display of time to
the nearest second. You can set most stick-on timers to
run from 1 to 60 seconds repeatedly. A timer with a
beeper that sounds every 15 seconds is recommended for
use in some industrial locations, because you can then
pay attention to your surroundings and your safety and
not the timer.
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Compass
A compass is needed to determine the direction of the
emission point from the spot where you stand to observe
the plume and to determine the wind direction at the
source. Select a compass that you can read to the nearest
2*. The compass should be jewel-mounted and liquid-
filled to dampen the needle's swing. Map-reading com-
passes are excellent for this purpose. Because you must
take the magnetic declination for your area into account
when you take the reading, you should consider invest-
ing in a compass that allows presetting the declination.
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Clinometer
Topographic Maps
United States Geological Survey (USGS) 7.5-minute to-
pological maps are a practical necessity for serious opac-
ity work. From these maps you can determine your exact
location, true north, distances, access roads, latitude, lon-
gitude, magnetic declination, relative ground height, and
background features. You also can use these maps to
calibrate rangefinders. If you are planning an inspection,
photocopy the section of the map that shows the facility
on the back of your observation form. Laminate the full-
sized map for field use and to allow for temporary mark-
ing with dry erasable pens.
Rangefinder
If you do not have a topographic map of the area, you
will need a rangefinder. Even with a map, a rangefuider
is useful in field work. The two types in general use are
the split-image and the stadiometric rangefinders. The
split-image type uses the technique of superimposing one
image over another to determine the distance. The most
useful models for most opacity work have a maximum
range of about 1,000 yards. To use the stadiometric
rangefinder, you must know the height or width of an
object at the same distance as the object of interest.
Stadiometric rangefinders are lighter and more compact
than split-image rangefinders. Split-image rangefinders,
although inherently more accurate, are more likely to
become uncalibrated if bumped during transport The
accuracy of either type of rangefinder should be checked
on receipt and periodically thereafter with targets at
known distances of approximately 100 meters and 1,000
meters. Any rangefinder must be accurate to within 10
percent of the measurement distance.
You will need a clinometric device for determining the
vertical viewing angle. For visible emission observation
purposes, it should be accurate within 3°. Many suitable
devices are available in a wide range of prices, includ-
ing Abbney levels, pendulum clinometers, and sextants.
Abbney levels use a bubble in a curved tube to determine
the angle with an accuracy of 1° to 2°. The pendulum
clinometer is the cheapest and has an accuracy of about
2° when used properly. It consists of a protractor and a
plum bob. A sextant is very accurate but more expensive.
and you will need to know the position of the actual
horizon.
Sling Psychrometer
If there is a potential for the formation of a condensed
water droplet "steam" plume, you will need a sling psy-
chrometer to determine the temperature and relative hu-
midity of the atmosphere. The sling psychrometer consists
of two thermometers, accurate to 0.5°C, mounted on a
sturdy assembly attached to a chain or strap. One ther-
mometer has a wettable cotton wick surrounding the bulb.
Thermometer accuracy should be checked by placing the
bulbs in a deionized ice water bath at 0°C. Electronic
models that use newly developed solid state sensors are
also available and do not have to be slung. Electronic
models are simpler to use but require tedious periodic
calibration using standard salt solutions.
Sling Psychrometer
Wet Bulb
Dry Bulb
10
-------
Binoculars
Binoculars are helpful for identifying stacks, searching
the area for emissions and interferences, and helping to
characterize the behavior and composition of the plume.
Binoculars are designated by two numbers, such as 7 x
35. The first number is the magnification and the second
is the field of view. Select binoculars with a magnifica-
tion of 8 or 10 (8 x SO and 10 x 50 are standard
designations). The binoculars should have color-corrected
coated lenses and a rectilinear field of view. Check the
color correction by viewing a black and white pattern,
such as a Ringelmann card, at a distance greater than 50
feet. You should see only black and white: no color
rings or bands should be evident Test for rectilinear
field of view by viewing a brick wall at a distance greater
than 50 feet. There should be no pincushion or barrel
distortion of the brick pattern. Plume observations for
compliance purposes should not be made through bin-
oculars unless you are certified with binoculars.
35 MM Camera And Accessories
Use a camera to document the presence of emissions
before, during, and after the actual opacity determination
and to document the presence or lack of interferences.
Photographs document the specific stack that is under
observation but do not document the exact opacity. Se-
lect a 35-mm camera with through-the-lens light meter-
ing, a "macro" lens or a 250 to 350-mm telephoto lens,
and a 6-diopter closeup lens (for photographing the photo
logbook). A photo logbook is necessary for proper docu-
mentation. An example of a photo log is provided in
Appendix A of this manual. Use only fresh color nega-
tive film with an ASA of approximately 100. You can
get first-generation slides or prints from negatives. Hie
first photograph is of the log, identifying the time, date,
and source. Log each photograph when you take it. The
last photograph is of the completed log. Instruct the pro-
cessor not to cut the film or print roll so that you can
refer to the photo log at the end of the roll to identify
each photograph.
CARRY EXTRA R0ULS OF
FRESH FILM AND USE A ,
FHOTOLOG
Video
Video is an excellent tool for opacity work. Because of
the wider tonal range of video, it does a better job of
reproducing the actual appearance of the plume than pho-
tography. In terms of resolution, video is poorer than
film. The best video systems for opacity work include
High 8 and Super VHS. Each gives 400 lines of resolu-
tion. Edited tapes have near broadcast quality and are
excellent for research and court work. Regular VHS or
regular 8 resolution is poor and duplicates are even worse.
Select the highest quality videotape available for your
system. Set and use the automatic date and time feature
when taping, title each shot in the field, and narrate
while taping. A sturdy tripod is as necessary as a good
camera.
SHOOT BACH SCENE R?R AT
LEAST 3 MNOTiS TO MAKE EDITING ;
EASIER. > -, : , xs '~: -- . - - , -
""'' '
Field Operations
Perimeter Survey
Before making your observations you need to determine
the correct viewing position for the source being moni-
tored, and you must also identify any potential interfer-
ences. You will need to select backgrounds, determine
the wind direction, and determine the position of the sun
relative to the source. You also should look for unlisted
sources at this time. If you do not consider each of these
items, the observation could be invalid.
Determine Sources
First, determine the sources of visible emissions at the
facility and identify the specific source that you are go-
ing to observe. Record the source identification on the
field data sheet Next identify any potential interferences
near the source for example, other visible emission plumes
from nearby sources, fugitive dusts from work activities
in the line of sight or obstructing buildings. Lastly,
identify any other sources that are unlisted but visible.
Determine The Position Of The Sun
Method 9 states:
The qualified observer shall stand at a distance sufficient
to provide a clear view of the emissions with the sun
oriented in the 140 sector to his back.
This means that a line from the sun to the observer and a
line from the observer to the observation point in the
plume must form an angle of at least 110 degrees. This
11
-------
will place the sun in the required cone-shaped 140 de-
gree sector. The purpose of this rule is to prevent for-
ward scattering of light transmitted in the plume. Forward
scattering enhances the plume visibility and creates a
positive bias in measurement results. In fact, every view-
ing requirement of the method is designed to prevent
positive bias.
DESIGNED mEUMCNA'TE POSmVE
Use a compass to determine the position of the sun in
terms of true north. Remember to correct the compass for
the magnetic declination at the site which might be dif-
ferent from that at your office location. When you posi-
tion yourself initially you will position the sun in a 140
degree sector to your back when you face the source. Use
the sun location line on the form for this initial check.
Now you must determine whether the vertical location of
METHOD 9 DOBS NOT STAtE THAT THE f
StfN MV$T BE IN A 140° HQ^Qf*T A.frJ -: '
CK'/r^VD ; '! », * ' ' '. ;:^ v> ;^
d£\ ,f< -, - , ,
the sun is acceptable. This is especially true under one or
more of the following conditions:
You are observing a tall stack
The sun is high overhead
You are observing the plume high in the sky
In the summer the sun can be as high as or higher than
60° in the sky during the solar noon (1 p.m.) at most
locations in the United States. If this is the case and the
plume observation point is only 15° in the vertical, the
combined vertical angle (from the observation point to
the observer to the sun) will violate the vertical require-
ments because the total of the vertical plume angle and
the vertical sun angle is at least 75° (which is less than
.the 110° specified minimum). Finally, the horizontal
and vertical angles have a combined effect. If the sun is
the sun is high overhead, or if the observation point is
high, or if the observation point is high and the sun is
close to the edge of the acceptable position, the final
angle will probably be unacceptable.
Determine The Point In The Plume To
Evaluate
Method 9 provides excellent guidance on the selection of
the spot in the plume to observe. This guidance is pre-
sented in several sections and, unless the method is read
in its entirety, the information can be confusing. The
following extractions from Method 9 address what to
consider in selecting the point in the plume for the ob-
servation.
Method 9 states:
2.3 OBSERVATIONS
Opacity observations shall be made at the point
of greatest opacity in that portion of the plume where
condensed water vapor is not present
This is the first and most significant criterion. It has
two elements that must be adhered to:
You must read opacity at the densest portion of
the plume
There cannot be any condensed water vapor at
the point of observation
o
If there is no condensed water droplet plume, you can
read at the densest pan of the plume. If there is a
"steam" plume, sections 2.3.1 and 2.3.2 explain how to
implement the rule.
Method 9 states:
2.3.1 ATTACHED STEAM PLUMES
When condensed water vapor is present within the plume
as it emerges from the emission outlet, opacity observa-
tions shall be made beyond the point in the plume at
which condensed water vapor is no longer visible. The
observer shall record the approximate distance from the
emission outlet to the point in the plume at which the
observations are made.
Read Here
12
-------
You must be sure that the condensed water aerosol has
re-evaporated and is not enhancing the opacity of the
paniculate matter in the plume. If the relative humidity
is high, water will hang on to paniculate matter, and if
the paniculate matter is hygroscopic, the water could
hang on at lower humidities. Either are unacceptable for
a valid observation. You can observe the plume from the
other side looking into the sun to determine where there
is a real break point in the steam plume. Do not look into
the sun when observing for record.
Method 9 states:
232 DETACHED STEAM PLUMES
When water vapor in the plume condenses and becomes
visible at a distinct distance from the emission outlet, the
opacity of emissions should be evaluated at the emission
outlet prior to the condensation of water vapor and the
formation of the steam plume.
(Note:. The word "shall" has been changed to" should"
in this subsection.)
If the steam plume is detached, you have two choices:
Read before the steam forms
Read after it evaporates
It is easy to choose between these options if you remem-
ber that "observations shall be made at the point of great-
est opacity" is your primary rule. If the plume is denser
before the steam plume forms, read there. If the plume is
denser after the steam plume evaporates, read there, un-
less there are specific directives to the contrary.
Certain complex plumes-those with high condensable
loadings or secondary reactive products-might present
problems in determining where to read the plume and
how to interpret the results. This is where your home-
work comes in. From the permits or emission test data
you should have a good feel for the material being emit-
ted. Some materials that have a strong affinity for water
might retain water far longer than others. Also, if the
ambient air humidity is high, there is less potential for
water to evaporate from particles. In either of these cases,
condensed water droplets containing paniculate contami-
nates could mimic paniculate matter. Other cases that
require caution are those in which condensed hydrocar-
bons are the principle component of the visible plume.
Some opacity regulations might not be applicable to
sources with consenting hydrocarbon plumes if the in-
tent of the emission standard was only to control primary
paniculate emissions detected by the emission control
system. An example is the case of "blue haze" plumes
from asphalt concrete batch plants, which have been de-
termined to be exempt from the NSPS opacity require-
ment.
Document The Point In The Plume
Where The Reading Was Taken
You must document on the data sheet the point in the
plume that you selected for the opacity reading. This
location should be documented in terms of distance from
the stack and in relative terms to any condensed water or
steam break. You can be sure that you will be challenged
later on this issue if there is reason to suspect that the
plume has a high moisture content or condensable emis-
sions.
Check For Direction Of Plume Travel
Method 9 states:
[The VE observer should] ...make his observations from a
position such that his line of vision is approximately
perpendicular to the plume direction.
1 SL
If you are observing the plume, you should be at least
three effective stack heights away from the plume. (The
effective stack height is the vertical distance between the
point where your horizontal line of sight intersects the
stack and the point in the plume where the observation is
to be made.) The intent is to keep within 18° of the
perpendicular to the plume. If the plume is horizontal,
make sure that your line of vision is approximately per-
pendicular to the plume at the point of observation. Again,
the line of sight should be within 18° of a perpendicular
to the plume line of travel. The reason for standing
approximately perpendicular to the plume when making
the VE determination is to use the shortest patnlength
through the plume, which will result in the most conser-
vative estimate of plume opacity.
13
-------
Adjust Your Field Location If
Necessary
After picking the point in the plume to observe, you
must recheck that you are in the correct position relative
to the sun and that point. If you are not, move. Recheck
each of the same factors at the new field position and
move again if necessary. Do not start observations until
all the factors conform to the regulations. It might be
necessary to come back at a different time of day to get
all the observation conditions acceptable.
METHOD 9 IS A METHOD OF OPPORTU-
NITY, THE VE INSPECTION MIGHT HAVE
TO BE DELAYED TO A DIFFERENT TIME
OF DAY IF VIEWING LOCATION OR CON-
DITIONS ARE WNACCEI-TABLE ;
i .,. f v . f s-,vi- : ' % v'f f Vs *< < " > v, V.V. Vv^Xvt %< "" vJjvt^X f.
W CONDITIONS CHANCJBDURINGTHE<&0-
SERVAT1ON, DOCUMENT ALL CHANGES IN
THE COMMENT SECTION '- \ '-/' *'^ , -
There is a comment section for each minute of observa-
tion. Use these comment sections to document events
that affect the validity of the observation, such as inter-
ferences or reasons for missing readings. Document
changes in your position or plume color.
When you conclude your observation session, record the
stop time in the appropriate section. Fill in the section
on observer and affiliation. Sign and date the form.
Enter the requested information concerning your last cer-
tification. A completed VE Observation Form is found
on.the next page.
Calculations
Performing The Observations
Compared to the preliminary activities, observing the
plume is easy. You will be filling out the upper left
section of the form first. Fill in the observation date in
the appropriate space on the form. Fill in the start time
when you make the. first observation. Use the 24-hour
clock to avoid confusion with a.m. and p.m. and indicate
the time zone. For example, 10:30 a.m. Eastern Day-
light Time should be recorded as 1030 EDT; 2:30 p.m.
Eastern Daylight Time should be recorded as 1430 EDT.
Method 9 states:
The observer shall not look continuously at the plume,
but instead shall observe the plume momentarily at 15-
second intervals.
Watch your timer and look up at the plume only momen-
tarily at the 0-, 15-, 30-, and 45-second intervals. It
takes only a few seconds to record your observation on
the form. Record your observations in 5-percent opacity
intervals unless the permit or regulation specifies other-
wise. Continue until you have made the required num-
ber of observations. Method 9 usually requires at least 24
observations for a complete data set. Good measurement
practice is to take more than the bare minimum required,
and it might be necessary to take more than one data set
to defend the observations against litigation in some
courts.
Method 9 Data Reduction
Method 9 states:
Opacity shall be determined as an average of 24 consecu-
tive observations...
Divide the observations recorded on the record sheet into
sets of 24 consecutive observations. A set is composed of
any 24 consecutive observations. Sets need not be con-
secutive in time and in no case shall two sets overlap.
This means mat you can select any set of 24 sequential
values to construct your final average. The best practice
is to construct a screening average (rolling average) of
each possible average in the data set and then select the
data combinations that you want to calculate. In an hour
of observations with no data gaps there are 227 potential
averages. Computer programs are available for this cal-
culation or you can construct a spreadsheet with a rolling
average to perform the calculation. If you are simply
determining noncompliance, you can often scan the data
to determine a data set that appears to violate the stan-
dard.
A SET DOES NOT HAVE TO START AT
THE BEGINNING OF A MINUTE
The set does not have to start at the beginning of a
minute; it can Stan at any point in the observation data.
Often this is the difference between compliance and non-
compliance.
14
-------
VISIBLE EMISSION OBSERVATION FORM
COMPANY NAME
LOCATION
4242A/MZDAD
JOCATION
CITY
STATE
>ROCESS EQUIPMENT
ZIP
1SM7
OPERATING MODE
MNTROL EQUIPMENT
OPERATING MODE
DESCRIBE EMISSION PONT
Oft
HEIGHT ABOVE GROUND LEVEL
75 FT.
DISTANCE FROM OBSERVER
START300
VERTICAL
9
fo
ANGLE
TO PLUME
EIGHT RELATIVE TO OBSERVER
START SO FT. END SAME
DIRECTION FROM OBSERVER
itART iV EN&onPlC
HORIZONTAL ANQLE TO PLUME
0,
DESCRIBE EMISSIONS
EMISSION COLOR
F WATER DROPLET PLUME
ATTACHEDD DETACHED^ NAD
POINT W THE PLUME AT WHICH OPACrTY WAS DETERMINED
si»maKffr/tac vwrn Aewfomfroo SAME
DESCRIBE PLUME BACKGROUND
BACKGROUND COLOR
WIND SPEED
START S-7
pup 7JJ
AM8QNT TEMP
START 65 ENQ 60
END
' acY coNomoNS
START CtEAR BoStMTlW
(WIND DIRECTION
START/"
WET BULB TEMP
S3
RH
SO
lewcx
SOURCE LAYOUT SKETCH
GUN
MTO
oHE>
EMS9QN PONT
DRMW NORTH AflROW
CD
w.
TIQN
SUN LOCATlb% LINE
INFORMATION
OBSERVATION DATE BTART TIME END TIME
FEB21, mf \irooEgT ws E&~
sic
MIN\
1
2
3
4
S
6
7
B
e
10
11
12
13
14
15
16
17
16
18
20
21
22
23
24
25
28
27
26
29
30
0
30
25
40
50
30
25
20
30
30
25
40
30
30
25
30
25
20
35
30
25
40
25
20
30
15
35
20
35
30
25
20
35
30
35
20
35
30
25
20
30
20
35
30
35
20
35
20
35
30
30
40
15
40
30
20
15
25
30
40
IS
40
30
20
IS
2S
30
15
25
30
40
IS
40
15
25
30
45
30
30
35
35
30
15
35
25
30
30
35
35
30
IS
35
25
15
35
25
30
30
35
15
35
25
COMMENTS
MT&FE&WPWAE
OBSERVERS NAME (PRINT)
OeSERVEFTS SIQNATURE
ORGANIZATION
GBilrlED BY
DATE
fEB 21. 199T
JAJt
/f TBMMGM ASSW/ATE
1. 1990
CONTINUED ON VEO FORM NUMBER
-------
Method 9 states:
For each set of 24 observations, calculate the average by
summing the opacity of the 24 observations and dividing
this sum by 24.
WHEN 1HE SIP DOESN'T A00RESS THE
ISSUE, METHOD 9 MTA REDUCTION 1$
USED -* ,
A simple mean is calculated for each data set and each
mean is compared to the standard. If any correction is
made for pathlength, it must be made before calculating
the average.
Method 9 states:
If an applicable standard specifies an averaging time re-
quiring more than 24 observations, calculate the average
for all observations made during the specified time pe-
riod.
Federal standards and SIP opacity regulations sometimes
contain averaging times other than 6 minutes. EPA's
policy is that if the SIP regulation does not clearly specify
an averaging time or other data-reduction technique, the
6-minute average calculations should be used. EPA is
currently in the process of providing additional methods
to cover alternative averaging times.
Time-Aggregation Standards
Time-aggregation standards are generaly stated in terms
of an opacity limit that is not to be exceeded for more
than a given time limit, such as 3 minutes, over a total
period, such as 1 hour. The usual technique is to count
the number of observations that violate the standard dur-
ing the observation period. Multiply the number of vio-
lations by 15 seconds to get the total number of seconds
in violation and divide by 60 to get the number of min-
utes of violation. Compare the answer to the standard.
EPA is in the process of promulgating methods that will
allow for time-aggregation calculations.
Data Review
Field Data Check
Before you leave the field, look over the form carefully.
Stan at the bottom right-hand section and work your way
up, following the form backwards. Make sure that each
section is either filled out correctly or is left blank on
purpose. All entries should be legible. Remember, this is
16
the first-generation copy and all subsequent copies will
be of lower print quality. As stated earlier in this manual,
the visible emission observation form is usually intro-
duced as evidence in enforcement litigation under the
principle of "past recollection recorded." This means
that you made entries on the form while they were fresh
in your mind. A five-minute review at this time can save
hours later.
Complete The Form
As soon as possible, gather the missing information and
complete the form. Do not sign the form until you have
completed all entries you intend to complete.
Method 9 warns:
....are recorded on a field data sheet at the time opacity
readings are initiated and completed.
Any additional entries made after you sign the form must
be dated and initialed. Failure to document changes
properly makes the observations subject to challenge. Even
the markout might have to be explained in a deposition
or in court.
XSCWBE EUBSON FONT
KEJOHT ABOVE GROJND LEVEL
7S/T.
HEIGHT RaXHVE TO OBSERVER
FT. END SAME
3SUNCE FROM OBSERVER
JTAmJO? ft. END SAME
VERTICAL ANGLE TO PLUME
9 DEGREES
DIRECTION FROM OBSERVER
STAHT/f 90 SAME
HOREDMWL ANGLE TO FUME
o DEGREES
Quality Assurance Audit
If the form is used as proof of compliance or of violation
in a permit application or of agency enforcement action,
a third party should review the'document in detail. The
following sections describe the elements of a minimal
audit.
After each item on the form is checked, you should com-
pare related data items for consistency. For example, check
if:
The wind direction arrow in the sketch agrees
with the wind direction recorded in the text sec-
tion of the form.
The final signature date is consistent with the
observation date.
The time of day is consistent with the sun posi-
tion.
-------
TOTON * MONTHS OF
OBSERVATION
Compare the date of the observation at the top of the
form with the date of the certification at the bottom of
the form. The observation date must be after the certifi-
cation but no more than 6 months after.
ALL REQUIRED POCUMENTATION
SUPPLIED
Horizontal sun angle is the easiest to check. Com-
pare the direction to the measurement point with the
position of the sun at that time of day. If the sun
location line on the suggested form is used, this should
be easy. If the line looks right, you must still check it
against the north arrow in the sketch. You can check
the sun location for accuracy using the US Naval
Observatory ICE program or solar tables. If all these
records are reasonable, you can calculate the horizon-
tal angle. The angle must be at least 110*. Next,
check the vertical sun angle. Add the vertical angle
of the observer's line of sight to the vertical line of
sight to the sun. The total of these two angles must be
less than 70*.
Method 9 has specific requirements for recording infor-
mation regarding the emission source or point observed
and the field conditions at the time of the observation.
Check to see whether the following information is pro-
vided on the VE Observation Form:
Name of the plant.
Facility and emission point location.
Type of facility.
Observer's name and affiliation.
Date and time of observation.
Estimated distance to the emission location.
Approximate wind direction.
Estimated wind speed.
Description of the sky conditions (presence and
color of clouds).
Plume background.
Sketch of sun, source, and observer positions.
Distance from the emission outlet to the point in
the plume at which the observations are made.
24 observations (unless other criteria exist).
If any of these items is missing, it will be pointed out in
a deposition, or in a motion before the court, or to the
judge when you are on the witness stand.
SUN AN0I*E REQUIREMENTS MET
VERTICAL, HORIZONTAL, AND COMBINA*
TION SUN ANGLES MUST BE ACCBFT.
ABL.E. , " / ^ , C ^ - \
Lastly, both horizontal and vertical angles must be
combined to get the resultant angle. This requires
solid trigonometry. Commercial computer programs
exist that perform the task. As a general rule, if the
total vertical angle is less than 60° and the horizontal
angle is above 130°, the resultant angle should be
acceptable. Otherwise, the observation is suspect
" SldHT LINE PERPIlNBIClJi^ TO ^ ,
,,,iin^^ONqp^m^TRA^ *:%v "
£ ^ SS ft AV*SV* %S f ffJfA ^V %* VV *Jtf,V V& .
> ' ^*^^ ^ V1=:''
%V >.V. S rt AS ->\ jt'f W.^^^ S%-.S
In order to assure that the sight line was approxi-
mately perpendicular to the direction of plume travel,
the slant angle should be less than 18°. Use the
distance from the stack and the effective stack height
to determine the angle. If the plume was horizontal
at the point of observation, check the sketch for the
direction of plume travel. Then check to see if the
plume direction and wind direction are reasonable.
Compliance with sun angle regulations is one of the most
difficult items to audit accurately because of inadequate
documentation. The angle created by the line of sight of
the observer and the line from the sun to the observer
must be at least 110°. This places the sun in the 140°
cone-shaped sector to the observer's back. Sun angle has
both horizontal and vertical components, and both must
be reviewed.
NON-CIRCULAR VENTS REAP ACROSS
SHORTEST AXIS ;
Check to see that the plume was observed along a
line of sight perpendicular to the long axis of the vent
if the vent is not circular. This is important when
observing fugitive emissions. Sources such as stor-
age piles, dusty roads, roof monitors, and ships' holds
are difficult to observe properly because of this
17
-------
requirement. ID many cases you must reach a compro-
mise between the axis of the source and the axis of the
plume. If the reading is not made from a position nearly
perpendicular to the plume, you should look at the final
opacity and determine whether correcting the data for
pathlength will still give the same final result in terms of
compliance status.
w s r s f.\ sy. : %s : j. .
-, ,,.-, ' .. ", '«, ,..-''.
OBSERVATIONAL INTERVALS
Were observations made at 15-second intervals or in
compliance with the applicable regulations?
DATA OAPS EXPLAINED
Were a minimum number of observations made with no
data gaps? If data gaps exist, are they explained? If an
average was calculated with a data gap, what value was
assigned to the data gap? What is the reason for select-
ing the value?
INTERFERENCES CHECKED AND NOTED
ONFORM ;V4 s ;;;^%r\l: - y -.""
* ' '' f *f s ^/\'^v s*&* -.-, I f O tV/ v-. ^^Xvi-^-XO>CfrS A^V ^x\s * v% %*-\ ^
Check for possible interferences. Obstacles in the line of
sight or other emission plumes in front of or behind the
plume being monitored create interferences that must be
avoided or noted on the data form. Review the sketch
for other vents, stacks, or sources of fugitive emissions
that might cross the line of sight or co-mingle with the
plume being evaluated and create a positive bias in the
observations. Compare any photographs to the sketch.
The sketch should indicate the backgrounds and their
relative distances. If mountains or other distant objects
are used as a reading background, check if haze is indi-
cated in the background section. This will potentially
create a negative bias in trie opacity readings. Also, note
in the comments section beside the observation whether
interferences were reported. Lastly, check the additional
information section and the data section for comments
regarding haze or other interferences.
STEAM PLUMES NOTED AND PROPER
PROCEDURES FOLLOWED
Was the emission observed at a point where there was no
condensed water? If the form indicates the presence of a
steam plume, pay special attention to the point in the
plume where the observation was made. Does it make
sense in relation to instructions given in sections 2.3,
2.3.1, and 2.3.2 of the Method 9? Check the ambient
temperature and relative humidity, if available. If the
temperature is low or if the relative humidity is high
(over 70 percent), consider the possibility of a steam
plume that does not evaporate easily. If the data are
available, model the steam plume using the technique in
EPA Quality Assurance Handbook, Volume EG, Section
3.12. When you use this model you must recognize that:
The charts were developed from steam tables to
represent the conditions in an ideal closed system,
and the atmosphere is not an ideal closed system.
The tables do not consider the presence of panicu-
late matter or condensation nuclei.
The temperature of the emission gases is an aver-
age of at least a one-hour emission test and does
not necessarily represent a steady-state condition
in the stack.
The moisture content entered into the calculation
is an average of at least one hour and might not
be representative of the plume conditions over a
shorter time frame. The chart does not recognize
that the plume might not be uniform in moisture
concentration and that some portions of the plume
might be at supersaturation.
The tables do not consider the presence of hygro-
scopic paniculate matter that could attract and
hold onto water by lowering its vapor pressure.
The chan is best used by constructing a line with an
error band that recognizes the associated error in mea-
surement of each of the input parameters. It should be
assumed that no water plume forms only if the error
band does not approach the dewpoinu
REDUCTION AN0 REPORTING
PREFORMED IN ACCORDANCE WITH
' '
Are the calculations in compliance with the regulation?
Does the regulation require averaging over a time period
other than 6 minutes? Does it require time aggregation?
Is the math correct? Was the highest average deter-
mined? Is there data showing noncompliance in excess
of the regulation in terms of opacity and time?
-------
Verify thai no interferences or extenuating circumstances
existed during the observation that would make the opac-
ity values not representative of actual conditions or oth-
erwise invalidate the observation.
AtlDIT
Depending upon the potential use of the form, it may be
wise to have an additional third party audit the form.
After completing the second audit, compare the results of
Pendem aUdiB "^ reS°lve *"* outstanding
-------
Further Readings
Field Observation Procedures:
Quality Assurance Handbook for Air Pollution Measurement Systems: Vol. m Stationary source Specific Methods,
Section 3.12 Method 9 Visible Determination of Opacity of Emissions from Stationary Sources, EPA 600/4-77-
027b, February 1984.
Guidelines for Evaluation of Visible Emissions: Certification, Field Procedures, Legal Aspects and Background
Materials, EPA 340/1-75-007, April 1975.
Guide to Effective Inspection Reports for Air Pollution Violations, EPA 340/1-85-019, September 1985.
Instructions for Use of the VE Observations Form, EPA 340/1-86-017.
Observer Training and Certification:
Self-Audit Guide for Visible Emission Training and Certification Programs, EPA 455/R-92-005.
Technical Assistance Document: Quality Assurance Guideline for Visible Emission Training Schools, EPA 600/4-
83-011.
Course 325 Visible Emission Evaluation: Student Manual, EPA 455/B-93-01 la, January 1994.
Opacity Evaluation Methods:
Optical Properties and Visual Effects of Smoke-Stack Plumes, AP-30, Revised May 1972.
Evaluation and Collaborative Study of Method for Visual Determination of Opacity of Emissions from Stationary
Sources, EPA 650/4-75-009, January 1975.
Measurement of the Opacity and Mass Concentration of Paniculate Emissions by Transmissometry, EPA 650/2-74-
128, November 1974.
20
-------
Appendix A
I ,Wil!! III ~::~ii~~~
aH ~m ~~.~~
~*"'m';,:;:;::',~~~~i~~i*f.y::.~.;::(~.~::".':.';:;~i~~~
'~~:~i.~:~J"j',j~i>.-i~I~I~!:~I'I:~~I>I:""i.'i:i;""'i'0i:}:".,i'/
-------
NAME
VISIBLE EMISSION OBSERVATION FORM
~=
DeSCRIBE EMISSION POINT
EMISSIONS
f£ a:::
~-$-
Me)
SOURCE LAYOUT SI(ETt:H
DAMV NORTH /IWOIi
o
.......
X EW/SSION I'ONT
SUN LOCV1ON UNE
I~~~OO
Not.D
OBSERIIAl1ON DAn rART T1ME 'EN) T1ME
~ 0 15 30 E COMWEMs
1
2
3
.
5 .
6
7
8
9
10
11
12
13
1.
15
16
17
18
19
2D
21
22
ZJ
2.
25
2IB
:0
28
29
30
NAME (PRIN'I)
SIGNATURE
0RGANIlA110N
BY
II~oo~~~
DJIIJ
-------
FUGITIVE OR SMOKE EMISSION INSPECTION
OUTDOOR LOCATION
c;::
Company
Location
Com an Re .
Sky Conditions
Precipitation
Industry
Observer
Affiliation
Date
Wind Direction
Wind Speed
Process Unit
Sketch process unit: indicate observer position relative to source and sun,
indicate potential emission points and/or actual emission points.
OBSERVATIONS
Begin Observation
Clock
time
Observation
period
duration,
min:sec
Accumulated
emission
time,
min:sec
End Observation
Figure 22-1
-------
FUGITIVE EMISSION INSPECTION
INDOOR LOCATION
Company
Observer
Location
Affiliation
Company Rep.
Date
Industry
Process Unit
Light type (fluorescent, incandescent, natural)
Light location(overhead,behind observr etc)
IIIuminance(lux or footcandles)
Sketch process unit: Indicate observer position relative to source; indicate
potential emission points and/or actual emission points.
OBSERV A TJONS
Begin Observation
Clock
time
Observation
period
duration,
min:sec
Accumulated
emission
time,
min:sec
End Observation
Figure 22-2
-------
Photo Log
Roll #
#
TimejDate
Subject
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
-------
Appendix B
Lm10 I "'-~:~'fbil:',
~;I~'*'i';\:~!"'&;:--!':~iiJ"'i;:;I~;;'i:;;<-}:H"::;;i~t~~:' ;~!"!'J>'!II:i,
R~a
'i~,:H::::/;:~f.;;};;,%*,,~~"~!'I'm:1"!' ;',I:<.~~%';"'I.'~;'i,:10j;;I~.=.:.~t!l.'(%:i~':~»j:J~!'~!ti,.!t.mI,~-,.~~'m~,~,'~::j@t::;;::1::1
Method 9 - Visual Determination
of the Opacity of' Emissions
from Stationary Sources
-------
Introduction
(a) Many stationary sources discharge visible
emissions into the atmosphere; these emissions
are usually in the shape of a plume. This method
involves the detennination of plmne opacity by
qualified observers. The methods includes ~
dures for the training and certification of observ-
ers and procedures to be used in the field for
detenninadon of plume opacity.
(b) The appearance of a plmne as viewed by an
observer depends upon a nmnber of variables,
some of which may be controllable in the field
Variables which can be controlled to an extent to
which they no longer exert a significant influence
upon plmne appearance include: angle of the 0b-
server with respect to the plume; angle of the ob-
server with respect to the sun; point of observation
of attached and detached Steam plmne; and angle
of the observer with respect to a plume emitted
from a rectangular stack with a large length to
width I31io. The method includes specific criteria
applicable to these variables.
(c) Other variables which may DOt be control1able
in the field are luminescence and color COJUrast
between the plmne and the background against
which the plmne is viewed. These variables exert
an influence upon the appearance of a plwne as
viewed by an observer and can affect the ability of
the observer to assign accmarely opacity values to
the observed plume. Studies of the theory of
plmne opacity and field studies have demonstrared
that a plmne is most visible and presems the
greaIest apparent opacity when viewed against a
conttasting background. Accordingly, the opacity
of a plume viewed W1der conditions where a con-
trasting background is present can be assigned
with the greateSt degree of accuracy. However,
the potential for a positive error is also the greateSt
when a plmne is viewed W1der such conttasting
conditions. Under conditions presenting a less
contrasting backgroWld, the apparent opacity of a
plume is less and approaches zero as the color and
lwninescence contrast decrease toward zero. As a
result. significant negative bias ai1d negative er-
rors can be made when a plmne is viewed Wlder
less contrasting conditions. A negative bias de-
creases rather than increases the possibility that a
plam operatOr will be incOITeCtly cited for a viola-
tion of opacity standards as a result of observer
error.
B-2
(d) Studies have been undertaken to determine the
magnitude of positive errors made by qualified observ-
ers while reading plumes under contrasting conditions
and using the procedures set forth in this method. The
results of these studies (field trials) which involve a
total of 769 sets of 25 readings each are as follows:
(1) For black plumes (133 sets at a smoke generator),
100 percent of the sets were read with a positive error
of less than 75 percent opacity; 99 percent were read
with a positive error of less than 5 percent opacity.
(Note: For a set, positive error = average opacity
determined by observers' 25 observations -average
opacity determined from transmissometer's 25 reconJ-
ings.)
(2) For white plumes (170 sets at a smoke generator,
168 sets at a coal-fired power plant, 298 sets at a
sulfuric acid plam), 99 percent of the sets were read
with a positive error of less than 75 percent opacity;
95 percent were read with a positive error of less than
S percent opacity.
(e) The positive observational error associated with an
average of twenty-five readings is therefore estat>-
lisbed. The accuracy of the method must be taken into
accouDt when determining possible violations of appli-
cable opacity standards.
L Principle And Applicability
Ll Principle. The opacity of emissions from station-
ary sources is determined visually by a qualified 0b-
server.
1.2 Applicability. This method is applicable for the
detem1ination of the opacity of emissions from station-
ary soun:es pursuant to fi 6O.11(b) and for visually
determining opacity of emissions.
2. Procedures
The ~ qualified in accordance with Section 3 of
this method shall use the following procedwes for vi-
sually detennining the opacity of emissions.
2.1 Position. The qualified observer shall stand at a
distance sufficient to provide a clear view of the emis-
sions with the sun oriented in the 14()O sector to his
back. Consistent with maintaining the above require-
ment. the observer shall, as much as possible, make
his observations from a position such that his line of
vision is approximately perpendicular to the plume
direction and. when observing op~ity of emissions
-------
from rectangular outlets (e.g., roof monitors, open
baghouses, noncircular StaCks), approximaJely per-
pendicular to the longer axis of the outleL The
observer's line of sight should not include more
than one plume at a time when multiple stacks are
involved. and in any case the observer should make
his observations with his line of sight perpendicular
to the longer axis of such a set of multiple stacks
(e.g., stub stacks on baghouses).
2.2 Field Records. The observer shall record the
name of the plant. emission location, facility type,
observer's name and affiliation, a sketch of the ob-
servers position relative to the source, and the date
on a field data sheet (Figure 9-1). The time, esti-
mated distance to the emission location, approxi-
mate wind direction. estimated wind speed,
description of the sky condition (presence and color
of clouds), and plume background are recorded on a
field data sheet at the time opacity readings are
initiated and completed.
. 2.3 OlRrvatioDS. Opacity observations shall be
made 81 the point of greateSt opacity in that portion
of the plume where condensed water vapor is not
present. The .observer shall not look continuously at .
the plume but instead shall observe the plume mo-
menrarily at IS-second intervals. .
2.3.1 Attached Steam Plumes. When condensed
water vapor is present within the plume as it emerg-
es from the emission outlet. opacity observations
shall be made beyond the point in the plume at
which condensed water vapor is no longer visible.
The observer shall record the approximare distance
from the emission outlet to the poilu in the plume at
which the observations are made.
2.3.2 Detached Steam Plume. When water vapor
in the plume condenses and becomes visible at a
distinct distance from the emission outlet. the opaci-
ty of emissions should be evaluared at the emission
outlet prior to the condensation of water vapor and
the formation of the steam plume.
2.4 Remrding OlRrvatious. Opacity observa-
tions shall be recorded to the nearest 5 percent at
IS-second intervals on an observational record
sheeL (See Figure 9-2 for an example.) A mini-
mum of 24 observations shall be recorded. Each
momentary observation recorded shall be deemed to
represent the average opacity of emissions for a 15-
second period.
2.5 Data Reduction. Opacity shall be determined
as an average of 24 consecutive observations record-
ed at IS-second interva1s. Divide the observations
recorded on the record sheet into sets of 24 cmsecu-
tive observations. A set is composed of any 24 con-
secutive observations. Sets need not be consecutive
in time and in no case shall two sets overlap. For
each set of 24 observations, calculate the average by
summing the opacity of the 24 observations and di-
viding this sum by 24. If an applicable standard
specifies an averaging time requiring more than 24
observations, calculate the average for all observa-
tians made during the specified time period. Record
the average opacity on a record sheet. (See Figure 9-
1 for an example.)
3. Qualification and Testing
3.1 CertifICation Requirements. To receive cenifi-
cation as a qualified observer, a candidate mUSt be
teSted and demonstrate the ability to assign opacity
readings in 5 percent incremenlS to 25 different
black plumes and 25 different white plwnes. with an
ClIO!' not to exceed 15 perteJU opacity on anyone
reading and average error not to exceed 7.5 percent
opacity in each caregory. Candidates shall be teSted
according to the procedures desaibed in Section 3.2.
Smoke generators used pursuant to Section 3.2 shall
be equipped with a smoke meter .which meets the
requirements of Section 3.3. The certification shall
be valid for a period of 6 months, at which time the
qnalification procedure mUSt be repeated by any 0b-
server in order to retain cenification.
3.2 Certification Proc:edure. The certification test
consists of showing the. candidate a complete nm of
50 plumes-25 black plwnes and 25 white plumes-
generated by a smoke generator. Plwnes within each
set of 25 black and 25 white nms shall be presemed
in I3Ddom order. The candidate assigns an opacity
value to each plwne and records his observation on a
suitable fonn. At the completion of each nm of SO
readings. the score of the candidate is determined. If
a candidate fails to qualify, the complete nm of 50
readings mUSt be repeated in any retesL The smoke
test may be administered as part of a smoke school or
training program and may be preceded by training or
familiarization nms of the smoke generator during
which candidates are shown black and white plwnes
of known opacity.
B-3
-------
3.3 Smoke Generator Specifications. Any
smoke generator used for the pmposes of Section
3.2 shall be equipped with a smoke meter in-
Stalled to measure opacity across the diameter of
the smoke generator stack. The smoke meter out-
put shall display in-stack opacity based upon a
pa1hlength equal to the stack exit diameter, on a
full 0 to 100 percent chan recorder scale. The
smoke meter optical design and perfonnance shall
meet the specifications shown in Table 9-1. The
smoke meter shall be calibrated as prescribed in
Section 3.3.1 prior to the conduct of each smoke
reading test. At the completion of each test. the
zero and span drift shall be checked and if the
drift exceeds :tl percent opacity, the condition
shall be corrected prior to conducting any subse-
quent test runs. The smoke meter shall be demon-
strated, al the time of installation., to meet the
specifiCalions listed in Table 9-1. This demon-
strarion shall be repeated following any subse-
quent repair or replacement of the photocell or
associated electronic circuitry including the chan
recorder or output meter, or every 6 months,
whichever OCCW'S first.
3.3.1 Calibration. The smoke meter is calibrat-
ed after allowing a miilimum of 30 minutes
warmup by alternately producing simulated Opaci-
ty of 0 percent and 100 percent. When stable
response al 0 percent or 100 percent is noted, Ihe
smoke meter is adjusted to produce an oulput of 0
percent or 100 percent. as 8ppIupriate. This cali.
bration shall be repeated wuil stable 0 percem and
100 percent opacity values may be produced by
alternately switching the power to the light source
on and off while the smoke generator is not pn>
docing smoke.
3.3.2 Smoke Meter Evaluation. The smoke
meter design and perfonnance are to be ev;duated
as follows:
3.3.2.1 Light Source. Verify from manufactur-
er's data and from voltage measurements made at
the lamp, as installed, that the lamp is operated
within :t5 percent of the nominal rated voltage.
3.3.2.2 Spectral Response of Photocell. Verify
from manufacturer's data that the photocell has a
photopic response; i.e., the spectral sensitivity of
the cell shall closely approximale the standard
spectral-lwninosity in (b) of Table 9-1.
£3.4
3.3.2.3 Angle of View. Check construction geometty
to ensure that the total angle of view of the smoke
plume, as seen by the photoeell, does not exceed 15°.
The total angle of view may be calcula1ed from: E = 2
tan.1 (d/2L), where E = total angle of view; d = the
sum of the photocell diameter + the diameter of the
limiting aperture; and L = the distance from the photo.
cell to the limiting aperture. The limiting aperture is
the point in the path between the photocell and the
smoke plume where the angle of view is most resttict-
ed. In smoke generator smoke meters this is nonnally
an orifice plate.
3.3.2.4 Angle of Projection. Check constJUcUon ge-
ometry to ensure that the total angle of projection of
the lamp on the smoke plume does not exceed 15°.
The total angle of projection may be calculated from:
E = 2 tan'l (d/2L)..where E = total angle of projection;
d = the sum of the length of the lamp filament + Ihe
diameter of the limiting aperture; and L = the distance
from the lamp to the limiting apertUre.
3.3.2.5 Calibration ErTor. Usingneutral-density fil-
ters of known opacity, check the enur between the
actual response and the theoretical linear response of
the smoke meter. This check is accomplished by fiM
. calibrating the smoke meter according to Section 3.3.1
and then inserting a series of three neutraI-density fil-
ters of nominal opacity of 20, SO, and 75 percent in the
smoke meter pathlength. Filters cah'brated within 2
percent shall be used. Care should be taken when
inserting the filters to prevent stray light from affect-
ing the meter. Make a toIal of five nonconsecutive
readings for each filter. The maximmn error on any
one reading shall be 3 percent opacity.
3.3.2.6 Zero and Span Drift. Detennine the zero
and span drift by calibrating and operating the smoke
generator in a normal manner over a I-hour period.
The drift is measured by dlecking the zero and span at
the end of this period. . .
3.3.2.7 Response Time. Determine the response time
by producing the series of five simulated 0 pen:ent and
100 percent opacity values and observing the time re-
.quired to reach stable response. Opacity values of 0
percent and 100 percent may be simulated by alter-
nately switching the power to the light source off and
on while the smoke geneI310r is not operating.
-------
Table 9-1. Smoke Generator Design And Performance Specifications
Parameter
Specification
a. Light source
Incandescant lamp operated at nominal rated voltage
b. Specttal response of
phoooceIl
c.
Angle of view
Photopic (daylight specttal response of the hmnan eye
-Citation 3)
15 1/2 maximum total angle
d Angle of projection
15 1/2 maximum total angle
e. Calibration error
:t 3 % opacity, maximum
f. Zero and span drift
j: 1 % opacity, 30 minuteS
g. Response time
:t 5 seconds
Bibliograpby
1. Air Pollution Control Disttict Rules and Regulalions, Los Angeles Cotmty Air Pollution Control District,
, Regulation IV, Prohibitions, Rule SO.
2. Weisburd, Melvin I., 'F1eld Operations and Enforcement Manual for Air, U.S. Enviromnerual Protection
Agency, Research Triangle Pmt, NC, APTD-llOO, August 1972, pp. 4.14.36.
3. Condon. E.U., and Odishaw, IL, Handbook of Physics, McGraw-Hill Co., New York, NY, 1958, Table
3.1, p. 6-52.
8-6
-------
Figure 9-1. Record of Visual Determination of Opacity
Company
Location
Test No.
Date
Type Facility
Control Device
Hours of Observation
Observer
Observer Certification Date
Point of Emissions
Observer Affiliation
Height of Discharge Point
Clock Time Initial Final
Observer Location
Distance to Discharge
Direction from Discharge
Height of Observation Point
Background Description
Weather Description
Wind Direction
Wind Speed
Ambient Temperature
Sky Conditions (clear, overcast,
% clouds, etc.)
Plume Description
Color
Distance Visible
Other Information
Set Number Time Opacity
Start - End Sum . Average
SUMMARY OF AVERAGE OPACITY
-------
Figure 9-2. Observation Record
Page
of
Company
Location
Test Number
Observer
Type Facility
Point 01 Emissions
Steam Plume
Seconds Comments
(Check if applicable)
Hr Min 0 15 30 45 Attached Detached
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
-------
Figure 9-2. Observation Record (continued)
Page
of
Company
Location
Test Number
Observer
Type Facility
Point of Emissions
Seconds Steam Plume
Comments
(Check if applicable)
Hr Min 0 15 30 45 Anached Detached
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
-------
Appendix C -. .
'" --_.""".~~w, -w" "m_v.~,~ ~ -"ij.-.-,.$>
')}<;~W~'<0WM,'n':"'k:~':::;w.!"'~:'T'~~~'~i';;:":':~~:'~2h\iili:*'-*~r':i:"''''"",M>*-.'.''1'M::i'%i''''8i"k>.',"ji':':v₯£i:':";"i',,:
':-i!-"'W ~
Method 22 - Visual Determination
of Fugitive Emissions from
Material Sources and Smoke
Emissions from Flares
-------
1. Introduction
1.1 This method involves the visual detennina-
tion of fugitive emissions, i.e., emissions not emit-
ted directly from a process stack or duCl Fugitive
emissions include emissions thai (1) escape cap-
lUre by process equipment exhaust hoods; (2) are
emitted during material ttansfer; (3) are emitted
from buildings housing material processing or
handling equipment; and (4) are.emitted directly
from process equipment this method is used also
to determine visible smoke emissions from flares
used for combustion of waste process materials. '
1.2 This method determines the amount of time
that any visible emissions occur during the obser-
vanon period, i.e., the accumuIared emission time.
This method does not require thai the opacity of
emissions be determined. Since this procedure
requires only the detenninaJion of whether a visi-
ble emission occun; and does not require the de-
tennination of opacity levels, observer
certification according to the procedures of Meth-
od 9 are not required Howevl2', it is necessary
that the observer is educated on the general
procedures for detennining the presence of visible
emissions. & a minimUm. the observer muSt be
trained and knowledgeable regarding the 'effects
on the visibility of emissions caused by back-
ground contrast. ambient lighting, observer posi-
tion rela1ive to lighting, wind., and the presence of
uncombined water (condensing water vapor).
This ttaining is to be obtained from written mare-
rials found in Citations I and 2 in the Bibliogm-
phy or from the lecture ponion of the Method 9
certification course.
2. Applicability And Principle
2.1 Applicability.
2.1.1 This method applies to the detennination of
the frequency of fugitive emissions from station-
ary sources (locaIed indoors or outdoors) when
specified as the test method for detennining com-
pliance with new source perfomumce standards.
2.1.2 This method also is applicable for the deter-
mination of the frequency of visible !moke emis-
sions from flares.
(;,2
2.2 Principle. Fugitive emissions produced during
material processing, handling, and transfer operations
or smoke emissions from flares are visually deter-
mined by an observer without the aid of instruments.
3. Defmitiom
3.1 ElllWiion Frequency. Percentage of time that
emissions are visible during the observation period.
3.2 Emission Time. Accumula1ed amount of time
thai emissions are visible during the observation peri-
od.
3.3 Fugitive Ernismons. Pollutant generated by an
affected facility which is not collected by a caplUre
system and is released to the annosphere.
3.4 Smoke ElllWiions. Pollutant generated by com-
bustion in a Oare and occmring immediately down-
stream of the flame. Smoke occurring within the
flame, but not downstream of the flame, is not consid-
ered a smoke emission.
3.5 Observation Period. Accumula1ed time period
during which observations are conducted, not to be
. less than the period specified in the applicable regula-
tion.
4. Equipment
4.1 Stopwatches. AccmnulaIive type with unit divi-
sions of 81 least 0.5 seconds; two required.
4.2 Light Meter. Light meter capable of measwing
illwninance in the 50 to 200-lux range, required for .
indoor observations only.
5. Procedure
5.1 Position. Survey the affecced facility or building
or stnlcture housing the process to be observed and
determine the locations of potenbaJ emissions. H the
affected facility is located inside a building, determine
an observanon location that is consistent with the re-
quirements of the applicable regulation (i.e., outside
observaJion of emissions escaping the building/struc-
ture or inside observation of emissions directly emitted
from the affected facility process unit). Then select a
position that enables a clear view of the potential emis-
sion point(s) of the affected facility or of the building
or structure housing the affected, as appropriate for Ihe
-------
applicable subpan. A position at least 15 feet, but
not more than 0.25 miles, from the emission source
is reconunended. For outdoor locations, select a
position where the sun is not directly in the observ-
er's eyes.
5.2 Field Records.
5.2.1 Outdoor Location. Record the following
infonnation on the field data sheet (Figure 22~1):
Company name, industry, process unit, observer's
name, obseIver's affiliation, and date. Record also
the estimated wind speed. wind direction. and sky
condition. Sketch the process unit being observed.
and note the observer location relative [0 the source
and the sun. Indicate the potential and acbJal emis-
sion points on the sketch.
5.2.2 Indoor Location. Record the following in-
foanation on the field data sheet (Figure 22-2):
Company name, industry, process unit, observer's
name, obseIver's affiliation. and date. Record as
appropriate the type, location, and intensity of light-
ing on the data sheet Sketch the process Wlit being
observed, and note observer location relative [0 the
source. Indicate the potential and actual fugitive
emission pOints on the sketch.
5.3 Indoor Lighting Requirements. for indoor
locations, use a light meter [0 measure the level of
illumination at a location as close 10 the emission
sources(s) as is feasible. An illumina1ion of greater
than 100 lux (10 foot candles) is considered neces-
sary for proper application of this method.
5.4 Observatiom. Record the clock time when
observations begin. Use one stopwatch 10 monitor
the duration of the observation period; start this
stopwa1Ch when the observation period begins. If
the observation period is divided into two or more
segments by process shutdowns or observer rest
breaks, stop the stopwa1Ch when a break begins and
restart it without resetting when the break ends.
SlOp the s[Opwatch at the end of the observation
period. The accwnulated time indicated by this
stopwatch is. the. duration of observation period.
When the observation period is completed, record
the clock time. During the observation period. COD-
tinuously watch the emission somce. Upon observ-
ing an emission (condensed water vapor is,not
considered an emission), start the second accumUla-
tive stopwatch; stop the watch when the emission
stops. Continue this procedure for the enIire observa-
tion period. The accumulated e1apsed time on this
stopwatch is the total time emissions were visible
during the observation period. ie., the emission time.
5.4.1 Observation Period. Oloose an observation
period of sufficient length [0 meet the requirements
for determining compliance with the emission regu-
1ation in the applicable subpan. When the length of
the observation period is specifically stated in the
applicable subpart, it may not be necessary to observe
the source for this entire period if the emission time
required 10 indicate noncompliance (based on the
specified observation period) is observed in a shorter
time period. In other words, if the regulation proJul>-
its emissions for more than 6 minutes in any bour,
Iben observaJions may (optional) be stopped after an
emission time of 6 minutes is exceeded. Similarly,
when the regulation is expressed as an emission fre..
quency and the regulation prohibits emissions for
greater than 10 percent of the time in any hour. then
observations may (optional) be terminated after 6
minutes of emission are observed since 6 minutes is
10 percent of an hour. In any case, the observation
period sball not be less than 6 minutes in duration.
. In some cases. the process operation may be inter-
mittent or cyclic. In such caseS. it may be convenient
for the observalion period 10 coincide with the length
of the ~ cycle.
5.4.2 Observer Rest Breaks. Do not observe emis-
sions continuously for a period of more than 15 to 20
minutes without taking a rest brea. Far sources
requiring observation periods of greJI1er than 20 min-
utes, the observer shall take a break of not less than 5
minutes and not more than 10 minutes after every 15
10 20 minutes of observation. If continuous observa-
lions are desired for extended time periods, two ob-
servers can alternate between making observations
and taking breaks.
5.4.3 Visua1lnterference. Occasionally, fugitive .
emissions from sources other than the affected facili-
ty (e.g., road dust) may prevent a clear view of the
affected facility. This may particularly be a problem
dming periods of high wind. If the view of the
potential emission points is obscured 10 such a de-
gree that the observer questions the validity of con-
tinuing observations, then the observations are.
terminated. and the observer clearly notes this fact
on the data fonn.
C-3
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s.s Recording ObservatioDS. Record the accu-
mulated time of the observation period on the data
sheet as the observation period duraliOIt Record
the ~u1ared time emissions were observed on
the data sheet as the emission time. Record the
clock time the observation period began and end-
ed, as well as the clock time any obselVer breaks
began and ended.
6. Calculations
H the applicable subpart requires that the emission
rate be expressed as an emission frequency (in
percent), determine this value as follows: Divide
the accwnula1ed emission time (in seconds) by the
durabon of the observation period (in seconds) or
by any minimmn observation period required in
the applicable subpan. if the actual observation
period is less than the required period, and multi-
ply this quotiem by 100.
Bibliography
L . Missan. Robert and Amold Stein. Guidelines for Evaluation of VISible Emissions Certification, FreId
Procedures, Legal Aspects. and Background Material. EPA Publication No. EPA-340/1-75-007. April 1975.
2. Wolmcl11egeI, P., and D.E. Wagoner. Guideline for Development of a Quality Assurance Program:
Volmne IX-Visual Determination of Opacity Emissions from Stmionary Sources. EPA Pub1icalion No. EPA-
6SO/4-74-OOSi. November 1975.
C-4
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FUGITIVE OR SMOKE EMISSION INSPECTION
OUTDOOR LOCATION
Company
Location
Com an Re .
Sky Conditions
Precipitation
Industry
Observer
Affiliation
Date
Wind Direction
Wind Speed
Process Unit
Sketch process unit: indicate observer position relative to source and sun,
indicate potential emission points and/or actual emission points.
OBSERVATIONS
.Begin Observation
Clock
time
Observation
period
duration,
min:sec
Accumulated
emission
time,
min:sec
End Observation
Figure 22-1
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FUGITIVE EMISSION INSPECTION
INDOOR LOCATION
Company
Observer
Location
Affiliation
Company Rep.
Date
Industry
Process Unit
Light type (fluorescent, incandescent,f1atural)
Light location(overhead,behind observr etc)
lIIuminance(lux or footcandles)
Sketch process unit: Indicate observer position relative to source; indicate
potential emission points and/or actual emission points.
OBSERVATIONS
Clock
time
Observation
period
duration,
min:sec
Accumulated
emission
time,
min:sec
Begin Observation
End Observation
Figure 22-2
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