United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park, NC
APTI/325-95-1
January 1995
Final Review Draft
Stationary Source Compliance Training Series
& EPA
VISIBLE EMISSION
EVALUATION PROCEDURES
COURSE
Student Manual
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Visible Emission
Evaluation Procedures
Course
Student Manual
APTI Course 325
Final Review Draft
Principal Author
Thomas H. Rose, Eastern Technical Associates
Style and Editing
Monica L. Loewy, The Leslie Group, Inc.
Peer Reviewers
Jay M. Willenberg, PE, Puget Sound Air Pollution Control Agency
Michael T. DeBusschere, PE, Private Consultant
Benjamin Jones, Oregon Department of Environmental Quality
Frank P. Terranglio, Portland State University
Grant Project Officer
Kirk E. Foster, U.S. Environmental Protection Agency
Developed By
Environmental Institute for Technology Transfer
University of Texas at Arlington
EPA Training Grant T-902743
Report # and Date
APTI/325-95-1
January 1995
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Contents
Preface
Lesson 1 Historical Background
Lesson 2 Principles of Visual Emissions Measurements
Lesson 3 Sources of Visible Emissions
Lesson 4 Meteorology
Lesson 5 Method 9 Requirements
Lesson 6 Other Methods
Lesson 7 Special Field Problems
Lesson 8 Documentation
Lesson 9 Equipment
Lesson 10 Field Training and Certification
Lesson 11 Presentation of Opacity Data in Court Cases
Lesson 12 Quality Assurance and Auditing
Answers to Review Questions
Additional Readings
1-1
2-1
3-1
4-1
5-1
6-1
7-1
8-1
9-1
10-1
11-1
12-1
A-l
B-l
1-2 • Course 325, Visible Emission Evaluation Procedures
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Lesson 1
History
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History
Early History
Most early U.S. and English case law concerning air contami-
nation fell under a part of the law commonly referred to as
nuisance law. In the absence of specific regulations or laws
against air pollutants, someone wanting to stop pollution (for
example, smoke from factories) had to bring a tort (or injury)
case against the offender. Smoke in general was not necessari-
ly considered a nuisance, however. Each case had to stand on
its own merit and prove that smoke was a nuisance. An early
example of a successful court case in which air pollution was
ruled a nuisance was an English case in which a lead smelter
produced fumes that killed a neighbor's corn.
Probably the earliest case upholding a municipal smoke-control
ordinance was the 1859 case City of New Orleans v. Lambert.
The Louisiana Supreme Court upheld an injunction against a
blacksmith shop because, in violation of a city ordinance, it
emitted offensive odors and smoke and was a nuisance. The
court upheld the police powers of the municipal government.
The problem of proving that smoke is an annoyance or is injuri-
ous to health in every case was well stated by Lord Romilly in
Crump v. Lambert in 1867: "The real question in all of these
cases is the question of fact, namely, whether the annoyance is
such as to materially interfere with the ordinary comforts of
human existence."
Industrial development increased toward the end of the 19th
century. With increased industry came increased awareness of
the health, social, and physical costs of industrialization and
city crowding. Communities passed regulations that sought to
control air pollution itself rather than to control nuisances caused
by air pollution. In 1881 the first smoke control ordinances
were adopted in Chicago and Cincinnati. Court records from
the late 19th and early 20th centuries contain many examples of
city and state prosecutions of smoke ordinance violations.
Notes
Historical Background • 1-3
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Notes
The proliferation of smoke ordinances set the stage for the
introduction of measurement science into the smoke-control
mechanism. Maximillian Ringelmann, a Belgian-born, Ger-
man-trained engineer working in France, developed a method
to quantify emissions according to the density of the observed
smoke. He developed the method, known as the Ringelmann
Chart, to assist in his studies of combustion efficiency. Using a
set of cards with patterns of black ink, he was able to categorize
the density of black smoke into four shades of darkness (see
Figure 1-1).
3 4
Figure 1-1. Ringelmann Cards
In 1899 the American Society of Mechanical Engineers recog-
nized the Ringelmann Chart as its official scale for determining
smoke density. In 1904 the U.S. Geological Survey used the
Ringelmann Chart in combustion studies for coal-fired sources,
giving it further credibility. Agencies and municipalities seek-
ing to improve the quality of the air quickly picked up the
Ringelmann system. By 1912,23 of the 28 cities in the United
States with populations of over 200,000 had adopted smoke
ordinances.
Ruling bodies soon recognized that the law of nuisance alone
was not adequate to prevent air contamination. What was
needed was a shift of emphasis away from individual com-
plaints toward community-wide concerns. In 1905 in the case
1-4 • Course 325, Visible Emission Evaluation Procedures
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of Glucose Refining Company v. City of Chicago, the court Notes
upheld the view that "the emission of dense smoke in populous
communities is a public nuisance." In Field v. Chicago the
court found that "smoke emitted from a tall chimney is carried
over a wide territory and that when dense, it deposits soot to
such an extent so to injure property and health wherever it
spreads."
At this point, the relationship between legislation and common
law becomes important:
• Legislation is all the statutes, laws, rules, regulations,
etc. passed by ruling bodies. Legislation is also called
statutory law.
• Common law is the body of court interpretations and
rulings that enhance, modify, and temper these legisla-
tive actions.
• Until statutory law has had its day in court and with-
stood the challenge, it is not fully established.
The need for enlarging the scope of the public nuisance defini-
tion was formally recognized in the Missouri case of State v.
Tower in 1904:
"It was entirely competent for the Legislature to take
cognizance of the fact, known to all men, that the emis-
sion and discharge of dense smoke in the atmosphere of
a large and populous city is of itself a nuisance ... and
one calculated to interfere with the health and comfort
of the inhabitants thereof, and to declare it a nuisance
per se .... We have no hesitancy in holding that it was
entirely competent for the Legislature to declare the
emission of dense smoke in the open air in a city of
100,000 inhabitants a nuisance per se."
Refinement In Law
Other specific problems regarding regulations of air pollutants
had to be addressed in the courts. One problem was how
liberal a view the courts had toward air pollution regulations.
Several cases speak to that issue. In Penn Dixie Cement Corp.
v. City ofKingsport in 1949 the court found that public health
Historical Background • 1-5
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Notes is the responsibility of the government. To that end, all reason-
able ordinances to protect public health have been sustained.
Legislators have wide discretion in determining what is a nui-
sance and also what is regulated under police power. The
courts do not interfere unless the law results in unnecessary
hardship. The courts can look behind the law to determine
whether the law is reasonable. In Moses v. United States the
court agreed that adapting regulations to meet specific condi-
tions is within the province of legislatures. The courts can
interfere only when regulation is not within police power and
only when private rights have been violated. This case raised
the issue of reasonableness. Any statute or ordinance must be
reasonable and must regulate something injurious to health,
safety, and welfare. "Reasonable" is a word subject to various
interpretations and this latitude of interpretation has generated
many cases. The following case review illustrates the courts'
general interpretation of "reasonable."
What is reasonable depends on the circumstances. In the 1884
case of Harmon v. Chicago in the Illinois Supreme Court, the
defendant argued that it was unreasonable to require the burn-
ing of expensive, clean fuel, such as anthracite coal, in place of
locally available bituminous coal. "Not so," said the court.
Although the holding in this case recognized that regulations
could be inconvenient or costly, the court's place is not to
address such issues. Cities have the authority to regulate.
Other decisions have held the following messages:
• In 1851 it was stated that the inconvenience must be
real, not imaginary, and must interfere with ordinary
comfort.
• In 1937 the courts found that the loss of even one
night's sleep is not a trivial matter (Andreae v. Selfridge).
After the parameters of "reasonable" had been determined, courts
upheld regulations, as in the following examples:
• In People v. Lewis (Michigan, 1891) it was found not
unreasonable to exempt certain classes (residences and
steamboats) from regulations.
1-6 • Course 325, Visible Emission Evaluation Procedures
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• In 1899 in the case of City of Brooklyn v. Nassau Elect Notes
RR a penalty of $100 for burning soft coal was collected
from Nassau Elect RR because of their violation of a
statute.
• Cincinnati v. Burkhardt (1908) upheld the use of a
color scale to measure smoke.
• In 1910 a Rochester, New York, statute upheld the use
of the Ringelmann scale. This statute prohibited smoke
from 5 a.m. to 7:30 am., presumably to protect com-
muters, and allowed dense smoke for only 5 minutes in
every four-consecutive-hour period.
In the early 1900s legislatures and municipalities were still
wrestling with the problem of air pollution. In 1916 a much-
cited case—Northwestern Laundry v. Des Moines—was filed
in the U.S. District Court in Iowa. This case, against the city
smoke inspectors and the smoke abatement board, sought to
enjoin or block the enforcement of a Des Moines regulation
that declared dense smoke in portions of the city a public nui-
sance. The plaintiff claimed that the ordinance was void for the
following reasons:
• Due process was guaranteed under the 14th Amendment.
• The Ringelmann Chart was arbitrary.
• The standard required the remodeling of almost all the
plaintiffs furnaces.
• In the permitting requirements for new construction,
inspectors and abatement commissioners had discretion
to require and prescribe requirements.
The court dismissed the case, saying:
So far as the federal Constitution is concerned, we have
no doubt the state may by itself, or through authorized
municipalities, declare the emission of dense smoke in
cities or populous neighborhoods a nuisance and sub-
ject to restraint as such; and that the harshness of such
legislation, or its effect upon business interests, short of
a merely arbitrary enactment, are not valid constitution-
Historical Background • 1-7
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Notes al objections. Nor is there any valid federal constitu-
tional objection in the fact that the regulation may re-
quire the discontinuance of the use of property, or subject
the occupant to large expense in complying with the
terms of the law or ordinance.
This landmark decision has been cited as a precedent in numer-
ous cases. The courts consider the problem settled. For exam-
ple, in 1950 in the Board of Health of Weehawken Township,
Hudson County (NJ) v. New York Central Railroad the court
referred to the Des Moines case and stated that there were no
constitutional restraints against the state's regulating dense smoke
injurious to the common welfare.
Historic Events 1945 To 1970
1945: Air pollution control began in the city of Los Angeles.
In the same year, Los Angeles developed the equivalent opaci-
ty concept that extended smoke density measurements to white
smoke, allowing for control of a larger number of air pollution
sources.
1950: California passed California Rule 50A, which was based
on the Ringelmann system, to limit smoke. This rule eventual-
ly was copied by almost all states and found its way into feder-
al new source performance standards (NSPS) promulgated 20
years later.
1953: Los Angeles County started its smoke-school program
for black smoke. The program was the beginning of standard-
ization of visible emission observation programs nationwide.
1955: The federal government enacted the 1955 Air Pollution
Control Act, the first of a series of air pollution control acts to
be passed by the federal government.
1963: Momentum increased with the passage by Congress of
the first Clean Air Act. Part of the Act provided grants to air
pollution control agencies.
1965: The Clean Air Act was amended to include Title 2,
Motor Vehicle Emissions Standards. This legislation recog-
nized that automobiles presented a pollution problem in many
areas of the country.
1-8 • Course 325, Visible Emission Evaluation Procedures
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1967: The Federal Air Quality Act was passed, moving the Notes
responsibility for automobile emission controls to the federal
government. The Act also required states to establish Air Qual-
ity Regions and to adopt Ambient Air Quality Standards, a
precursor to the modern State Implementation Plans (SIPs).
1968: The federal government published AP-30, a joint indus-
try and government study of opacity, leading the way for strong
emphasis on opacity as a federal regulatory tool.
1970 (Earth Year): A new wave of environmental activity
swept the country. Intensive media attention heralded the in-
crease of public support for pollution control agencies and their
efforts to protect the public. The National Environmental Poli-
cy Act was passed on January 1, 1970. It signified a federal
commitment to use all practical means to promote the general
welfare and to attain harmony with the environment. A new set
of Clean Air Act Amendments also was established in 1970.
Creation Of EPA
EPA was created in 1970 out of federal agencies that included
the National Air Pollution Control Administration from the
Public Health Service, Water Pollution Control from the De-
partment of Agriculture, and Solid Waste and Radiation from
the Public Health Service. EPA was created to consolidate
environmental activities at the federal level and to support state
and local control and research efforts.
In 1971 EPA promulgated national ambient air quality stan-
dards for the following pollutants:
• Sulfur dioxide
• Nitrogen dioxide
• Paniculate matter
• Photochemical oxidants
• Carbon monoxide
Selected Cases
The cases described below either set important precedents or
serve as examples of key legal principles.
Historical Background • 1-9
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Notes In 1973 EPA proposed a new Portland cement standard of 10-
percent opacity for emissions from Portland cement plants. The
Portland Cement Association sued the EPA Administration on
the grounds that the accuracy of the opacity method was not
adequate to support the standard. EPA spent the next year
conducting field studies on the method. As a result of those
field studies, EPA:
• Raised the opacity limit for Portland cement plants from
10 to 20 percent
• Revised the data reduction scheme of Method 9 to
averaging.
• Established more specific observation and training
requirements.
These revisions resulted in the first modern version of Method
9. Since its promulgation, the method has undergone only one
minor change: it now requires a sketch that indicates the rela-
tive positions of the observer, the sun, and the source.
The concept of free and open fields was settled in the Western
Alfalfa case (1976). This case is important because it estab-
lished the right of an inspector to go onto the property of a
company as long as the inspector stays in areas that are accessi-
ble to the public and does not cross a barrier or go through a
gate.
Inspectors who were denied entry to a plant in New York filed
a court case (known as the Dormer Hanna case) that ended in a
landmark decision. Its implications were serious. The source
was a coke oven battery being regulated under rules in the state
implementation plan (SIP), and both EPA and the state were
involved in the case. The source was being regulated under a
time aggregation rule patterned after California Rule 50A. Emis-
sions from the battery were timed with a stopwatch in accor-
dance with historical precedents in New York and Pennsylvania.
Inspectors were denied entry by the source on the following
grounds:
• In the absence of a promulgated state measurement
method, the method of measurement must be Federal
1-10 • Course 325, Visible Emission Evaluation Procedures
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Reference Method 9 as found in the new source perfor-
mance standards (NSPS).
• Because the inspectors intended to use a time aggrega-
tion technique rather than Method 9, they had no usable
method.
The court upheld the company position and denied entry to
EPA inspectors. This case focused attention on the differences
between Federal Reference Methods and SIP methods that were
used by states and EPA without being officially promulgated
within the agencies.
Typical Regulation
A typical regulation might read as follows:
No source shall suffer or permit to emit into the
atmosphere an emission with an opacity equal to or
greater than 20 percent for 3 minutes in any 1 hour.
It is important to analyze the elements of the regulation to
ensure that the full meaning of the rule is understood.
No source shall suffer or permit
The source cannot purposely or accidentally create an emission.
to emit into the atmosphere an emission
Emission into the atmosphere includes emissions into the air
inside a building if all the inside air is not captured by hoods or
ductwork and processed by control equipment. Thus, even
fugitive emissions from building leaks are included in emissions.
with an opacity equal to or greater than 20 percent
The most common opacity standard is 20 percent (in other
words, the opacity reading must be less than 20 percent). Some
SIPs still have 40-percent regulations. Some of the NSPS are
down to 3 percent or less.
for 3 minutes in any 1 hour.
Notes
Historical Background • 1-11
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Notes This is the time exemption allowing for startup, etc. Even if
the regulation is for 3 minutes, a 6-minute average is necessary
to prove a violation unless an alternative method is clearly
specific and has been through formal promulgation.
1-12 • Course 325, Visible Emission Evaluation Procedures
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Review Questions
1. In early U.S. and English case law, smoke was dealt with as a
2. Who developed the first method used to quantify emissions according to the density
of the smoke?
3. A1949 court case determined that public health is the responsibility of .
4. In 1937 in Andreae v. Self ridge the courts found that the loss of even
was not a trivial matter.
5. In the landmark
. case, the court ruled that the state can declare the
emission of black smoke a public nuisance.
6. In what year did the federal government pass the first Air Pollution Control Act?
7. What Act in what year first included automobile emission regulations?
8. In 1970 what federal agency was formed from the National Air Pollution Control
Administration from the Public Health Service, Water Pollution Control from the
Department of Agriculture, and Solid Waste and Radiation from the Public Health
Service?
9. The Donner Hanna case established the right of an inspector to enter the property of
a company as long as the inspector .
10. The Donner Hanna case focused attention on the differences between Federal
Reference Methods and .
11. Match the following:
A) Ruling bodies
B) Common law
C) Statutory law
1) Until it has had its day in court and withstood the
challenge, it is not fully established.
2) Pass statutes, laws, rules, regulations, etc.
3) Body of court interpretations and rulings that
enhance, modify, and temper laws.
Historical Background • 1-13
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Lesson 2
Principles Of Visual
Emissions Measurement
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Principles Of Visual Emissions
Measurement
This lesson defines basic concepts related to opacity and
discusses the scientific principles associated with measuring
opacity and the practical application of those principles.
Ringelmann Method
As outlined in Lesson 1, the system of visible emissions evalu-
ation evolved from a concept developed by Maximillian
Ringelmann in the late 1800s. Ringelmann used a chart of
calibrated black grids on a white background to measure dark
or black smoke emissions from coal-fired boilers. The grids
ranged from approximately 20-percent ink coverage for a
Ringelmann #1 through 100-percent ink coverage, or solid black,
for a Ringelmann #5 (see Figure 2.1). The observer simply
compared the shade of the smoke with the shade of the card.
Notes
Figure 2-1. Ringelmann Chart
Principles of Visual Emissions Measurement • 2-3
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Notes
Equivalent Opacity
In the early 1950s, the Ringelmann concept was expanded to
include colors of smoke other than black by introducing "equiv-
alent opacity." Equivalent opacity is the opacity equivalent to
the obscuring power of black smoke characterized by a specific
Ringelmann grid. Thus, a Ringelmann #1 was equivalent to
20-percent opacity. The major difficulty in the equivalent opacity
system was not the scientific basis of the system but that opaci-
ty witnesses frequently could not explain to a court how white
was equivalent to black.
The federal government has discontinued using the Ringelmann
numbers in EPA Method 9 procedures for new source perfor-
mance standards (NSPS). Although current procedures are
based solely on opacity, some state regulations (notably Cali-
fornia's) still specify the use of the Ringelmann Chart to evalu-
ate black and gray plumes. The general trend, however, is
toward reading all visible emissions in percent opacity.
Opacity And Transmission Of Light
Plume opacity is defined as one of the following:
• The degree to which light transmission through the di-
ameter of a plume is reduced.
• The degree to which the visibility of a background
viewed through the diameter of a plume is obscured.
When light strikes an object or substance, the light is either
reflected, absorbed, or transmitted. The amount of light that is
reflected and absorbed determines the opacity of the substance.
Simply put, in the observation of a pollutant plume, opacity is
the obscuring power of the plume.
In terms of physical optics, opacity is related to transmittance
(I/I0) through the plume. Percent opacity and percent
transmittance always total 100 percent. Percent opacity is defined
by the following equation:
2-4 • Course 325, Visible Emission Evaluation Procedures
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Percent opacity = (1 - I/IQ) x 100 Notes
in which: IQ = the incident light flux (the light that enters
the plume)
I = the light flux leaving the plume along the
same path
Many factors influence plume opacity readings: particle densi-
ty, particle refractive index, particle size distribution, particle
color, plume background, pathlength, distance and relative ele-
vation to stack exit, sun angle, and lighting conditions.
Light And Particles
The wavelengths of visible light in the electromagnetic spec-
trum range from 400 nanometers (nm) for blue light to 700 nm
for red light. Below 400 nm is the ultraviolet (UV) frequency,
and above 700 nm is the infrared (IR) frequency (see Figure
2.2). Human vision peaks in the middle of the visible range, at
550 nm, a yellowish-green color. This color is seen the best,
and not coincidentally, it is also the best background for light-
colored plumes.
Ultraviolet Infrared
(UV) (IR)
400 nm 550 nm 700 nm
Blue Yellow Red
Green
Figure 2-2. Electromagnetic Spectrum
Opacity is a function of the interaction between light over this
visible spectrum and particles. This interaction is affected by
properties of both the particles and the light that include:
• Number and size of the particles
• Particle shape
• Particle color
• Index of refraction of the particles
Principles of Visual Emissions Measurement • 2-5
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Notes • Spectral characteristics of the light
• Light direction
• Amount of light
When light hits a particle, one of two things can happen: the
light can either be transmitted through the particle, or it can be
affected by the particle. Mechanisms by which the particles
affect light include absorption and scattering. Light scattering
mechanisms include reflection, refraction, Rayleigh scattering,
and Mie scattering. These mechanisms are affected in turn by
the particle and light properties defined above.
Transmission
The least likely but simplest interaction of a particle and light is
transmission, which involves light passing completely through
the particle in its initial direction. For light to be transmitted
through a particle, the light must hit the front and back surfaces
of the particle exactly perpendicular and the particle must be
clear. Even in the rare cases that meet these conditions, light
will be attenuated (weakened) as a consequence of absorption.
Absorption
If a particle has any color or is black, it will absorb a certain
amount of light as the light enters the particle. The energy of
the light is converted to heat in the particle. The energy simply
warms the particle, just as a black seat cover in a car is heated
by the summer sun. Black particles absorb all colors of light,
whereas colored particles absorb only specific wavelengths of
light.
Scattered Light
Scattered light is light diverted from its original path of trans-
mission. The two main light-scattering mechanisms for large
particles are reflection and refraction (see Figure 2-3). For
smaller particles, the main light-scattering mechanisms are
Rayleigh and Mie scattering. The observed opacity of colored
particles depends strongly on the light-scattering properties of
those particles, not on the absorption of light entering the parti-
cles.
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Notes
Reflection Refraction
Figure 2-3. Large-Particle Light-Scattering
Reflection
Reflection occurs when light "bounces off1 a surface rather
than passing through it. The surface color and texture of a
particle determine its reflective quality. A white particle re-
flects light more readily than does a black particle. Even a
black particle can reflect light if the surface is smooth, howev-
er. An everyday example of reflection from black materials is
the mirror effect of well-polished black marble.
Refraction
Simple refraction is the bending of light as it goes through a
transparent medium. Lenses, such as those used in eyeglasses,
work by refraction. When a light wave hits the curved surface
of a particle, the light wave turns toward the particle center.
Subsequently, the light leaves the particle along a different line
than that of its entrance.
Rayleigh Scattering
When particle size is significantly smaller than the wavelength
of light, the light is widely scattered (see Figure 2-4a). Rayleigh
scattering is important for extremely small particles because
they scatter much of the light away at large angles from the
forward direction. Rayleigh scattering is responsible for the
typically blue color of the sky: blue light is scattered out from
the light coming directly from the sun. Extremely small particles
create a bluish plume even if the individual particles are actually
colorless. Fine particles are often referred to as blue smoke in
the control-equipment industry.
Principles of Visual Emissions Measurement • 2-7
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Notes
One wavelength One wavelength
Destructive Constructive
interference interference
(a) (b)
Figure 2-4. Small-Particle Light-Scattering: Rayleigh (a)
and Mie (b)
Mie Scattering
When particle size and the wavelength of light are approxi-
mately the same, Mie scattering occurs (see Figure 2-4b). Light
waves reflecting off the inside surfaces of a particle can either
add together constructively or subtract destructively as they
move from the separate locations within the particle. Light can
also be refracted from the edges of the particle and contribute to
the scattering interference patterns. Visible light scattering from
emission particles below 1 /^m falls within the Mie scattering
range.
Particle Size
Given that particles decrease light transmission by both scatter-
ing and direct absorption, particle size plays a significant role in
opacity. Particles with diameters approximately equal to the
wavelength of visible light (0.4 to 0.7 microns) have the great-
est scattering effect and cause the highest opacity. These parti-
cles, PM]0 particles, are in the respirable range.
Variables Influencing Opacity
Observations
The appearance of a plume as viewed by an observer depends
on a number of variables, some of which might be controllable
2-8 • Course 325, Visible Emission Evaluation Procedures
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and some of which might not be controllable in the field. Notes
Variables that might not be controllable in the field are lumi-
nous contrast and color contrast between the plume and the
background against which the plume is viewed. These vari-
ables influence the appearance of a plume as viewed by an
observer and can affect the ability of the observer to assign
accurate opacity values to the plume. Studies of the theory of
plume opacity and field studies have demonstrated that a plume
is most visible and presents the greatest apparent opacity when
it is viewed against a contrasting background.
Color contrast is the difference in color between two objects.
For instance, red and orange are different colors but the differ-
ence between them is not nearly as great as that between red
and blue. If the plume color is identical to the background
color, the visible emissions observer will have difficulty distin-
guishing between the plume and the background. One manu-
facturer reportedly used this principle to lower its apparent
opacity by painting its facility the same color as its paniculate
emissions. This tactic deprived the observers of backgrounds
of a contrasting color. To the degree possible, the observer
should maximize the color contrast between the plume and the
background to get the most accurate readings.
Luminous contrast is the difference in light emanating from
two objects, for example, a black plume against a light sky.
Two objects that have the same color can show up against each
other because of these differences in lighting levels. This effect
is important in the case of forward scatter, in which plumes
become more luminous than their background. Luminous con-
trast is vital to a color-blind observer. Also, luminous contrast
is the primary tool for observing a light-colored plume against a
light-colored sky.
When reading light-colored plumes, it is useful to have a pat-
terned background as a target. The degree to which the pattern
is obscured is another tool to assist in determining the opacity.
Patterned backgrounds can include trees, buildings, towers, pow-
er poles, mountains, or even other stacks at the source.
Selecting The Background
All the factors discussed above are important in selecting the
proper background for an opacity determination.
Principles of Visual Emissions Measurement • 2-9
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Notes
For black smoke, a light-colored background is best and light-
blue sky is excellent (see Figure 2-5). Because the black smoke
does not scatter the light, it is not necessary or desirable to use a
textured or patterned background.
For white smoke, a dark-colored background with texture or a
pattern is best (see Figure 2-5). The observer is often faced
with only a blue sky background because of stack height. Gen-
erally, the deeper the blue, the more accurate the observations.
A black plume should be read against a light background.
A white plume should be read against a dark, textured
background.
Figure 2-5. Plume Background
During all observations, it is important that the observer look
through the smoke at the background and also at the back-
ground without the smoke. The observer should compare the
2-70 • Course 325, Visible Emission Evaluation Procedures
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background appearances under both conditions and not focus Notes
only on the appearance of the background through the emis-
sions. The observer should remember that the goal in deter-
mining opacity values is to judge how much the unobscured
background is changed by the emissions.
Mass Emissions/Opacity Relationship
Generally, denser plumes have more particles and, consequent-
ly, higher mass emissions. When Method 9 was promulgated,
the relationship between opacity and mass emissions was not
well developed. Today, opacity can be predicted if sufficient
information about the emissions is available. Factors that affect
the mass emissions/opacity relationship include:
• The number of particles
• The particle size distribution
• The pathlength through the plume
• The density of the particles
• The spectral characteristics of the light
• The index of refraction of the particle
• The opacity of the plume in terms of transmission
The relationship can be described by the following equation:
in which: C = mass concentration
K = particle size distribution
R = particle density
T = equivalent transmittance
P = pathlength through the plume
As the pathlength through the plume increases, the opacity
increases because the number of particles between the source of
light and the detector or observer has increased.
The natural log, In, of the equivalent transmittance, which is
referred to as optical density, is also directly proportional to
particle concentration. All other factors being equal, opacity is
a function of the number of particles in a specified size distribu-
tion per unit volume of gas. Particle density is used to convert
particle concentration to mass concentration.
Principles of Visual Emissions Measurement -2-11
-------
Review Questions
1. A Ringelmann #2 would have what percent ink coverage?
2. What was the major difficulty with the concept of equivalent opacity?
3. Define opacity.
4. In the following picture, what is the opacity of substance A?
5. Name four properties that affect opacity.
6. Match the following.
A) Absorption 1) ™
B) Refraction
Q Transmission
2) -zurr
3)
D) Rayleigh scattering 4)
E) Reflection
F) Mie scattering
5)
6)
7. The difference between the color of two objects is the
The difference in the light emanating from two objects is the
8. An observer should (maximize/minimize) the luminous contrast and color
contrast between plume and background.
9. An excellent background for black smoke is
An excellent background for white smoke is
2-12 • Course 325, Visible Emission Evaluation Procedures
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I
I Review Questions
I
| 10. If one has sufficient information (such as number and size of particles, plume
I pathlength, etc.) one can predict .
I
I 11. If the pathlength increases, the opacity .
Principles of Visual Emissions Measurement • 2-13
-------
Lesson 3
Sources Of Visible
Emissions
-------
Sources Of Visible
Emissions
A wide range of industries produce visible emissions. This Notes
lesson discusses the types of emissions and their causes, emis-
sion sources, emission components, plumes, and visible emis-
sions control equipment.
Emissions
Visible emissions come in many shades, but they are usually
categorized as either black or white (non-black) emissions. Black
particles absorb visible light; white, or non-black, particles scat-
ter visible light.
Black emissions are produced when solid fuels or residual oils
are burned under poor combustion conditions in an oxygen-
deficient environment. Unburned carbon particles cause a visi-
ble black plume, as do magnesium dioxide, hematite, and some
material-handling processes.
White (non-black) emissions are produced as a by-product of
combustion, either as the result of hydrocarbon vaporization,
excess combustion air, or loss of flame. Also, white emissions
occur as a result of a condensation reaction or as fine dust from
material handling.
Emission Sources
Visible emissions are introduced into the atmosphere by stacks,
vents, conveyor lines, and other non-point sources, such as
storage piles and unpaved roads.
Stacks
Many sources send their emissions into the atmosphere
through smokestacks. A stack is a pipe or runnel through
which smoke and gases are discharged. Stacks vary in
Sources of Visible Emissions • 3-3
-------
Notes height and diameter; the opacity of the plume can be influ-
enced by these characteristics.
Tall stacks influence readings by increasing the sun/slant angle
and by eliminating the possibility of a high-contrast background.
When a white plume is observed, a contrasting background,
such as trees or a hillside, is desirable. Sometimes, however,
the sky is the only background for a tall stack. If the sky is
overcast, this can cause a negative bias of readings, especially
with light-colored plumes.
Wide stacks or large-diameter stacks can cause a higher-than-
expected opacity ratio because of the increased pathlength
through the plume.
Emissions from non-circular stacks, including oval, rectangu-
lar, and square stacks, should be read across the narrowest axis
of the plume. The observer should pre-select the time of day
and pay close attention to wind conditions at the time of the
observation, because these factors can severely limit the ob-
server's ability to read the stacks correctly from the best posi-
tion.
Readings of emissions exhausted horizontally are strongly limited
by wind direction, which could cause difficulty in making accurate
readings. For example, an emission port facing west would be
unreadable with a west wind, and the plume could be sheared off
by either a north or south wind. Sun angle also might be difficult
to reconcile, depending on the direction of the emission port and
on the visual interference presented by the stack itself. The ob-
server should ascertain the appropriate meteorological conditions,
as well as the proper time of day for acceptable sun angle, before
performing visible emissions observations.
Fugitive Emissions
Fugitive emissions come from non-specific point or area sourc-
es that include:
• Roof monitors
• Unpaved roads
• Gaps in duct work
• Doors
• Storage piles
• Conveyors
3-4 • Course 325, Visible Emission Evaluation Procedures
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Notes
Particles that comprise fugitive emissions are often larger than
those found in a stack gas stream and, therefore, tend to settle
out of the cloud more rapidly.
Studies have shown, however, that fugitive dust plumes also
have a significant PM-10 dust-particle component. Fugitive emis-
sions are caused by many mechanical processes, such as:
• Crushing
• Drilling
• Sanding
• Vehicle movement
• Grinding
• Sweeping
• Demolishing
• Material handling
Visible Emission Components
Visible emissions contain a variety of particles in sizes ranging
from 0.1 micrometer (um) to 200 urn. Particles are categorized
as:
• Smoke
• Soot
• Fly ash
• Dust
• Fumes
• Mist
• Gas
• Condensed vapor
Smoke is a visible effluent resulting from incomplete combus-
tion. Smoke consists mostly of soot, fly ash, and other solid or
liquid particles.
Soot consists principally of carbon particles that contain at-
tached or absorbed tars and other hydrocarbons. Soot is formed
by the incomplete combustion of carbonaceous material and is
the principal cause of the blackness of a smoke plume. Soot
particles are generally quite fine (1/um or less).
Sources of Visible Emissions • 3-5
-------
Notes Fly ash, which is unbumed material from fuel combustion,
consists of particles small enough to remain suspended in the
air. A pure fly ash plume is light-brown or cream colored. If a
system achieves nearly complete combustion, fly ash is prima-
rily inorganic material. The quantity of inorganic fly ash emit-
ted depends on the fuel's ash content. Distillate fuels do not
contain appreciable amounts of ash. Residual oils can have an
ash content of up to 0.3 percent by weight, but the ash content
for oil grades 4 and 5 cannot exceed 0.1 percent.
Dust consists of solid particles, generally greater than 1 urn in
diameter, released into the air by processes such as drilling,
crushing, and grinding. Because these particles are larger than
smoke or fume particles, they tend to settle to the ground more
quickly.
Fumes consist of metal or metal oxide particles less than 1 urn
in diameter. These minute particles are created when vapors
generated by high-temperature metallurgical processes condense.
Fumes are common in metallurgical industries such as steel
and aluminum production.
Mist consists of liquid droplets. A pollutant could be the pri-
mary material that forms the droplet, or it could be suspended
or dissolved in droplets of a different material. Typical droplets
have diameters of about 10 um and range from 2 to 200 um in
diameter. It can be difficult to distinguish pollutant-containing
mists from innocuous water droplets that are generated from
steam condensation.
Gas is a fluid, like air, that has neither specific shape nor vol-
ume but tends to expand indefinitely. Two visible pollutant
gases are nitrogen dioxide (NO,), which is brown to yellow,
and chlorine, which is greenish yellow.
Vapor is the gaseous phase of a substance that, at normal tem-
perature and pressure, is a liquid or solid, such as vapor from
gasoline. Most vapors have no color, but they can refract light.
In doing so, they alter the image of a background pattern.
3-6 • Course 325, Visible Emission Evaluation Procedures
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Condensing And Reacting Plumes
Plumes that form in the atmosphere are generally called con-
densing plumes. The visible material in a condensing plume
could be particles or droplets generated either by homogeneous
condensation of gases or as products of chemical reactions. In
some cases, both mechanisms are involved.
Condensing Steam Plumes
The classic condensing plume is the steam plume. Sources of
water that can cause steam plumes include:
• Drying operations that remove water by evaporation
from foods, chemicals, detergents, paper, pharmaceuti-
cals, ores, etc.
• Combustion of hydrogen or hydrocarbon fuels, particu-
larly natural gas. If wet organic material is burned,
water vapor is generated by both evaporation and com-
bustion reactions.
• Air pollution control devices that use water to suppress
dust generation or to remove gases or particles from the
gas stream (e.g., spray chambers, spray towers, venturi
scrubbers).
• Evaporation of water to remove combustion or chemical-
reaction heat from a process (e.g., forced- and natural-
draft cooling towers, operations for cooling hot gases to
protect pollution control equipment, removal of the heat
generated in the thermal process of producing phosphoric
acid).
• Thermal processes that break down and release chemi-
cally bonded water, such as cement production.
Reacting Plumes
Some gases can be mixed under dry conditions without react-
ing with one another, but when these same gases are mixed
with water droplets, they react and generate a reaction product
that dissolves in the droplet. When the water evaporates, the
reaction product remains as a solid particle. For example, when
Notes
Sources of Visible Emissions • 3-7
-------
Notes sulfur oxides, ammonia gases, and water vapor mix in the same
gas stream, the sulfur dioxide and ammonia react on the surface
of the water droplets and an aqueous solution with dissolved
ammonium sulfate is generated. The water evaporates back
into the atmosphere, leaving an ammonium bisulfate particle.
This reaction can occur in kilns at cement plants and brick-
manufacturing plants.
Control Equipment
The basic control devices for particulate emissions are classi-
fied as:
• Mechanical collectors
• Wet scrubbers
• Fabric filters
• Electrostatic precipitators
• Afterburners
Mechanical Collectors
Settling chambers and cyclones are mechanical particulate-matter
collectors. In settling chambers, the gas stream is slowed down
through a chamber so that particles can settle out. Although
their design is simple, collection chambers require large spaces
and have low collection efficiencies for small particles. A
cyclone separates the particulate matter from the gas stream via
inertia! force. The gas stream containing the particles is forced
in a circular path. The denser particles migrate to the outside
walls and then slide down the walls into a collection bin. Wa-
ter is used on the walls of some cyclones to wet down the
particles and help them slide to the bottom. Neither settling
chambers nor cyclones efficiently collect the smaller particles
responsible for most visible plumes.
A more efficient version of the cyclone is the centrifugal wash-
er or scrubber. In the centrifugal scrubber, the particle-laden
air stream is impinged on a stream of water droplets, which trap
the particles. The water droplets containing the particles are
then denser and larger than the particles and can be more easily
collected by cyclonic action. Because the centrifugal scrubber
adds moisture to the air stream, there is often a condensing
plume of water droplets (steam plume) at or beyond the lip of
the stack.
3-8 • Course 325, Visible Emission Evaluation Procedures
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Wet Scrubbers Notes
Wet scrubbers operate by trapping particles and gases and wash-
ing them away. Gases are absorbed by the liquid and can form
corrosive compounds. Collection efficiencies of wet scrubbers
can be high for larger particles, but normally are lower for
smaller particles. Again, the presence of moisture often leads to
the creation of a steam plume. Wet scrubbers often are fol-
lowed by mist eliminators.
Fabric Filters
Fabric filtration is one of the most widely used methods for
removing fine particles in gas. When particle-laden gas passes
through a filter, the particles are retained on the dirty-gas side
of the filter, while the gas passes through the filter and the filter
cake that builds up on the filter surface. Accumulated dust
particles are removed from the filter by a shaking motion, a
pulse-jet motion, or reverse air flow. The filters are usually in
the shape of long tubes suspended from the ceiling of a room,
giving the buildings that hold them the name "baghouses." The
baghouse is more efficient than any of the mechanical devices
for collecting small, high-opacity particles. Some sources have
dry injection systems before the baghouse to coat the fabric
with agents that will absorb, adsorb, or "react out" gas stream
components. When a visible emission is observed from a fab-
ric-filter-controlled source, it is usually a result of either broken
bags or a secondary reaction in the plume.
Electrostatic Precipitators
The electrostatic precipitator works by electrically charging the
suspended particles in a gas stream, collecting the matter on a
plate that has been grounded or has an opposite charge, and
removing the matter to an external hopper by rappers or by
flushing with liquids. The precipitation rate depends on:
• The electrical properties of the particles
• The electrical properties of the gas stream
• The velocity of the gas stream
• The voltage
• The design of the charging and collection plates
Sources of Visible Emissions • 3-9
-------
Notes
High collection efficiencies, up to 99.9 percent, can be achieved
with the electrostatic precipitator over a wide range of particle
sizes. Actual collection efficiency, however, depends on design
and process conditions.
Afterburners
Afterburners remove combustion process products that can still
be oxidized. Afterburners dispose of fumes, vapors, odors, and
low amounts of combustible materials remaining in the gas
stream. The two basic types of afterburners are direct-flame
and catalytic burners.
Direct-flame burners are used to complete the combustion pro-
cess. They can be inefficient unless some secondary heat re-
covery system is used. Catalytic units are unsuitable for particles
because the particles can clog or poison the catalyst. Many of
the wood stoves currently sold in the United States contain a
catalytic afterburner, as do most automobiles.
3-10 • Course 325, Visible Emission Evaluation Procedures
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Review Questions
1. How do black particles and white particles react with visible light?
2. Emissions from burning solid fuels or residual oils in an oxygen-deficient environ-
ment are:
a. Black
b. White
3. How do the majority of sources send emissions into the atmosphere?
4. Viewing a h'ght-colored plume against an overcast sky can cause readings that
are biased:
a. Higher than actual opacity (positive)
b. Lower than actual opacity (negative)
5. Horizontally emitted emissions readings are limited by:
a. Wind direction
b. A west wind
c. Sun angle
d. All the above
6. Visible emissions contain a variety of particles. What are they?
7. True or false? Dust particles are smaller than smoke or fume particles and,
therefore, settle to the ground more slowly.
8. What are two visible pollutant gases?
9. What is the visible material in a condensing plume and how is it generated?
10. What are the types of control devices for particulate pollutant emissions?
Sources of Visible Emissions -3-11
-------
Lesson 4
Meteorology
-------
Meteorology
Visible emissions observers need to understand the basic prin-
ciples and terminology used in meteorology to fill out observa-
tion forms. This knowledge will also promote effective
communication in meetings and courtrooms.
Wind
Notes
Meteorologists usually consider two factors in describing wind:
speed and direction. It is important to use standard terminology
in describing these factors. The information recorded on visible
emissions forms can be confusing if the observer fails to use
standard terminology to describe wind conditions. The follow-
ing discussion describes how wind affects visible emissions
readings and presents the terminology that observers should use
to describe wind conditions.
Wind speed has several direct effects on smoke plumes:
• Wind speed determines the height that a plume will
attain before it bends horizontally. If the wind speed is
high enough, the plume could even shear off at the
stack and re-form downwind.
• Wind speed affects opacity measurements by -diluting
the plume.
Wind speed is usually measured in miles per hour. If an ane-
mometer is not available to make a direct measurement of wind
speed, the modified Beaufort scale can be used (See Table 4-1
on the next page).
Wind direction specifies the direction from which the wind
blows. Thus, a north wind comes from the north and blows to
the south. Wind directions might vary, especially with light
winds. The observer should be positioned at an angle of ap-
proximately 90 degrees (perpendicular) to the direction of the
Wind direction is
specified by the
direction from which
the wind blows.
Meteorology • 4-3
-------
plume. Wind direction and wind speed help determine the ex-
act position of the observer, as stated in Method 9.
Table 4-1. Beaufort Wind Scale (Modified)
General wind
classification
Description of effects
Limits of velocity
33 ft (10m) above
the ground, mph
Calm
Light
Gentle
Moderate
Fresh
Strong
Gale
Whole gale
Hurricane
Smoke rises vertically Below 1
Direction of wind shown by smoke drift but not
by wind vanes 1 to 3
Wind felt on face; leaves rustle; ordinary vane
moved by wind 4 to 7
Leaves and small twigs in constant motion; wind
extends light flag 8 to 12
Raises dust and loose paper; moves small branches 13 to 18
Small trees in leaf begin to sway; crested wavelets
form on inland waters 19 to 24
Large branches in motion; whistling heard in telegraph
wires; umbrellas used with difficulty 25 to 31
Whole trees in motion; inconvenience felt in walking
against the wind 32 to 38
Twigs broken off trees; progress against wind
generally impeded 39 to 46
Slight structural damage occurs (e.g., chimney pots
and slates removed) 47 to 54
Trees uprooted; considerable structural damage occurs 55 to 63
Rarely experienced; accompanied by widespread
damage 64 to 75
Most rare; accompanied by severe, widespread
damage Above 75
4-4 • Course 325, Visible Emission Evaluation Procedures
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Plume Types
When a smoke plume is emitted into the atmosphere, its shape
is determined by the following factors:
• Plume temperature
• Vertical temperature profile of the atmosphere
• Wind speed
• Emission velocity
A plume rises if it is more buoyant than the surrounding air.
Generally, such conditions occur when the plume is hotter than
the atmosphere. If the air above a plume is more buoyant than
the plume, the plume cannot rise.
The change in air temperature at increasing altitude is called the
lapse rate. Normally, the lapse rate is about 5°F for each
1,000 feet of altitude. This means that the air will be 5°F cooler
at 1,000 feet than at the surface of the earth. The interaction
between the temperature of the plume and the temperature of
the surrounding air strongly affects the shape of the plume.
Plumes can be categorized into the following five types:
• Coning
• Lofting
• Looping
• Fanning
• Fumigating
These plume types and the conditions involved in their forma-
tion are described and illustrated on the following pages.
Notes
Meteorology • 4-5
-------
Coning
Description
• Roughly cone-shaped with horizontal axis
• Dissipates farther downwind than looping plume
Temperature
Temperature Profile—Stability
• Lapse rate between dry adiabatic and
isothermal-neutral or stable
Typical Occurrence
• During windy conditions, day or
night
• Layer-type cloudiness favored in day
• Might also occur briefly in a gust
during looping
Associated Wind and Turbulence
Moderate to strong winds
• Turbulence largely mechanical rather than thermal
Dispersion and Ground Contact
• Disperses less rapidly with distance than does looping plume
• Large probability of ground contact some distance down
wind
• Concentration less but persisting longer
than that of looping
Ground-level Patterns
• Top view of stack
4-6 • Course 325, Visible Emission Evaluation Procedures
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Lofting
Description
• Loops or cone with well-defined bottom and poorly
defined, diffuse top
x*—. Atmospheric
profile
Temperature Profile—Stability
• Adiabatic lapse rate at stack top and
above ^_
• Inverted below stack layer—lower ^
layer is stable, upper layer is neutral "0
or unstable -1-
Typical Occurrence
• During change from lapse to
inversion condition
• Usually near sunset on fair days
• Lasts about an hour but could persist through night
Associated Wind and Turbulence
• Moderate winds and considerable turbulence aloft
• Light winds and little or no turbulence in the layers
below
Dispersion and Ground Contact
• Probability of ground contact small unless inversion
layer is shallow and stack is short
• Concentration high with contact, but contact usual
ly prevented by stability of inversion layer
• Considered best condition for dispersion because
pollutants are dispersed in upper air with
small probability of ground contact
Ground-level Patterns
• Top view of stack
Dry adiabatlc
lapse rate
Temperature
Meteorology • 4-7
-------
Looping
Description
• Irregular loops and waves with random, sinuous
movements
• Dissipates in patches, relatively rapidly
CD
Temperature Profile—Stability
• Adiabatic or super-adiabatic lapse
rate—unstable
Typical Occurrence
• During daytime with clear or partly cloudy
skies and intense solar heating
• Not favored by layer-type cloudiness, snow
cover, or strong winds
Associated Wind and Turbulence
• Light winds and intense thermal turbulence
Dispersion and Ground Contact
• Disperses rapidly with distance
• Large probability of high concentrations sporadically
at ground relatively close to stack
Ground-level Patterns
• Top view of stack
Atmospheric
profile
Dry adiabatic
lapse rate
\
Temperature
4-8 • Course 325, Visible Emission Evaluation Procedures
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Fanning
Description
• Narrow, horizontal fan; little if any vertical spread
• If stack is high, resembles a meandering river, widening but not
thickening as it moves
• Can be seen miles downwind
• If effluent is warm, plume rises slowly and drifts horizontally
Temperature Profile—Stability
• Inverted or isothermal lapse
rate—stable
Typical Occurrence
• At night and in early morning,
any season
• Usually associated with inversion
layer(s)
• Favored by light winds, clear
skies, and snow cover
Associated Wind and Turbulence
• Light winds
• Little turbulence
D)
"(D
Atmospheric
profile
-------
Fumigating
Description
• Fan or cone with well-defined top and ragged or diffuse
bottom
Temperature Profile—Stability
• Adiabatic or super-adiabatic
lapse rate at stack top and
below
• Isothermal or inverted lapse
rate above—lower layer
unstable or neutral, upper
layer stable
Dry Qdiabatlc
\ lapse rate
Typical Occurrence
• During change from inversion to lapse condition
• Usually nocturnal inversion is being broken up through
warming of ground and surface layers by morning sun
• Breakup commonly begins near ground and works
upward, less rapidly in winter than in summer
• Can also occur with sea breeze in late morning and early
afternoon
Associated Wind and Turbulence
• Winds light to moderate aloft and light below
• Thermal turbulence in lower layer, little turbulence in
upper layer
Dispersion and Ground Contact
• Large probability of ground contact in relatively high
concentration, especially after plume has stagnated aloft
Ground-level Patterns
• Top view of stack
Temperature
4-10 • Course 325, Visible Emission Evaluation Procedures
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Sky Condition Notes
Sky condition is another important meteorological parameter.
Reporting sky condition can make the total visible emission
observation records more complete and credible. Sky condition
includes the presence of clouds and other obscuring phenome-
na, such as haze or rain. These conditions can seriously affect
the contrast between the plume and the background. Contrast is
also affected by the elevation of the sun and the location of the
observer with respect to the plume.
Sky cover affects the observation in at least three ways:
• Sky cover determines whether the plume is in shadow
or in bright sunlight. When the plume is in shadow, the
sun's position has less effect on the apparent opacity
than it might have when the plume is in direct sunlight.
This difference can be readily observed on overcast
days.
• The background against which the plume is observed
might be the sky. The color of the sky, along with the
presence or absence of clouds, will affect the contrast
and the apparent opacity of the plume.
• Clouds might cover the sun intermittently during the
observation. These changes in lighting can have a detri-
mental effect on emissions observations if the observer
is not evaluating how the plume alters the view of a
background.
Relative Humidity
Relative humidity is the amount of moisture in the air com-
pared with the amount of moisture that could be in the air (i.e.,
saturation). Relative humidity is affected by:
• The temperature of the air
• The amount of moisture in the air
At higher temperatures, the air can hold more water vapor.
When the temperature drops below the dew point, however, the
relative humidity reaches 100 percent and moisture is forced
Meteorology 4-11
-------
Notes out of the air in the form of mist, fog, haze, rain, sleet, snow, or
dew.
The relative humidity affects several aspects of visible emis-
sions determinations:
• It can create mist, fog, or haze
• It can create rain
• It affects the formation and persistence of steam plumes
If the humidity is high enough to cause mist, fog, or haze to
form, the contrast between the plume and the background can
be diminished. This lower contrast can lead to a negative bias
in the observation. The same problem occurs when rain is fall-
ing and the background is some distance from the source.
If the temperature of the air is cool enough and the humidity is
high enough, the moisture exiting the stack cannot enter the air.
Under these conditions, a steam plume will form in the atmo-
sphere. The higher the humidity and the lower the temperature,
the longer a steam plume persists. If the relative humidity is
70 percent or above, steam plumes will persist for long periods
of time and will travel correspondingly long distances.
4-72 • Course 325, Visible Emission Evaluation Procedures
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Review Questions
1. What are the two factors meteorologists use to describe wind?
2. List two ways in which wind speed directly affects smoke plume formation.
3. List four factors that determine plume shape.
4. Define relative humidity.
5. At higher temperatures, air can hold (more/less) water.
6. The higher the humidity and the lower the temperature, the (longer/
shorter) the steam plume will last.
7. Match the plume type with its name.
1. Looping
2. Lofting
3. Coning
4. Fumigating
5. Fanning
A.
Meteorology 4-13
-------
Lesson 5
Method 9 Requirements
-------
Method 9 Requirements
Method 9 Notes
EPA Reference Method 9 (or Method 9) is the visible emis-
sions inspection method most frequently used by visible emis-
sions observers. It has been tested in the courts and in practice
and has wide acceptance within the regulatory community. The
purpose of this lesson is to acquaint students with the details of
the method as they are described in the method itself. The
students must know and understand the method to apply it.
When EPA promulgated Method 9, the text of the method was
preceded by a preamble that explains EPA's rationale in devel-
oping the method. The preamble also provides some historical
perspective on the method:
On June 29, 1973, the United States Court of Appeals for
the District of Columbia remanded to EPA the standard of
performance for Portland cement plants (40 CFR 60.60 et
seq.) promulgated by EPA under section 111 of the Clean
Air Act. (Portland Cement Association v. Ruckelshaus. 486
F.2d 375 [1973].) In the remand, the court directed EPA to
reconsider, among other things, the use of the opacity
standards.
All other versions of Method 9 are based on the EPA promul-
gation remanded in this historic case.
The Reference Method Is One Of Observation
EPA established that Method 9-type observations take prece-
dence even when transmissometers are used:
"EPA will accept as probative evidence in certain situations
and under certain conditions the results of continuous mon-
itoring by transmissometer to determine whether a violation
has in fact occurred."
Method 9 Requirements • 5-3
-------
Notes The revision makes clear that even in such situations the results
of opacity readings by Method 9 remain presumptively valid
and correct. In other words, human observers collect the best
evidence.
EPA recognized that because transmissometers and CEMs are
located within the stack, often well before the actual point at
which the emissions enter the atmosphere, the readings from
these instruments might not represent the opacity at or above
the emission point. Aerosols can form after the transmissome-
ter within the stack or above the stack by gas-phase reactions,
condensation, or accumulation. Consequently, the best measure
of opacity at the stack is presumed to be the visible emissions
readings obtained by applying Method 9.
Opacity Variances
EPA recognized that in some limited cases, opacity can be an
unfair measure of emissions:
The provisions in paragraph (e) provide a mechanism for
an owner or operator to petition the Administrator to estab-
lish an opacity standard for an affected facility where such
facility meets all applicable standards for which a perfor-
mance test is conducted under 60.8 but fails to meet an
applicable opacity standard. The intent of this provision is
primarily applied to cases where a source installs a very
large diameter stack that causes the opacity of the emis-
sions to be greater than if a stack of the diameter ordinarily
used in the industry were installed (see Figure 5-1).
Figure 5-1. Opacity Varies With Stack Diameter
5-4 • Course 325, Visible Emission Evaluation Procedures
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The effect of stack diameter on opacity is not inconsequential. Notes
Transmission (and, consequently, opacity) is directly propor-
tional to the square of the pathlength. A plume with an opacity
of 20 percent will have an opacity of 36 percent if the stack
diameter is doubled.
A few industries have seized upon this provision, ignoring the
condition about 'Very large diameter stack," to justify their
requests for an alternate opacity provision. A high opacity rela-
tive to measured mass emissions, however, can result from
small particles (PM|0) in the gas stream, reactions that occur in
or above the stack downstream from the particulate test, and
condensation of particulate that occurs downstream from the
particulate test. More-sophisticated mass emissions testing tech-
niques often will detect the additional mass that an observer
would record during a Method 9 observation.
Portland Cement Standard Set At 20
Percent
After reviewing the data from field tests and the opacity of
Portland cement plant tests, EPA revised the 10 percent stan-
dard originally proposed. As noted in the preamble:
A revision to the opacity standard for Portland cement plants
is promulgated herein. The revision changes the opacity
limit for kilns from 10 percent to 20 percent. This revision
is based on EPA's policy on opacity standards and the new
emission data from Portland cement plants evaluated by
EPA during its reconsideration.
Standards of around 20 percent are common in existing NSPS,
and state and local agency regulations. Today, however, regula-
tions often contain lower opacity standards. Values of 10 per-
cent, or even 3 percent, are being applied to industry.
EPA Policy On Opacity
The preamble to the standards of performance for Portland
cement plants, which were proposed on March 8, 1974 (39 FR
9308), sets EPA's policy on opacity standards. This policy has
three elements:
Method 9 Requirements • 5-5
-------
Notes • Opacity limits are independently enforceable standards.
• When opacity and mass/concentration standards apply
to the same source, they are established at a level that
will result in the design, installation, and operation of
the best, adequately demonstrated system of emission
reduction (taking costs into account).
• Opacity standards are established at a level that re-
quires proper operation and maintenance of such con-
trol systems.
The first element clearly shows EPA's thinking that an opacity
violation does not have to have a corresponding mass emis-
sions standard violation. As previously noted, a violation of a
mass emissions standard can go undetected because of the mea-
surement limitations in conventional mass emissions testing.
The second element addresses setting standards in terms of
mass. The intent is to ensure that emissions are minimized by
installing state-of-the-art control system designs.
The last element illustrates one of the roles of opacity stan-
dards. If an opacity standard is set at a level the facility can
meet when it is properly maintained and operated, then an
opacity violation would indicate that the facility is not being
operated properly or has not been adequately maintained. A
facility can be fined for exceeding the opacity standard without
additional evidence that the mass emission limit was violated.
Revising The Opacity Limits For Portland
Cement Plants
The preamble to the Portland cement plant standards of perfor-
mance states:
The new data indicate that increasing the opacity limit for
kilns from 10 percent to 20 percent is justified, because
such a standard will still require the design, installation, and
operation of the best adequately demonstrated system of
emission reduction (taking costs into account) while elimi-
nating or minimizing the situations where it will be neces-
sary to promulgate a new opacity standard under 60.11 (e).
5-6 • Course 325, Visible Emission Evaluation Procedures
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EPA recognized that the 10-percent standard was not always Notes
approachable in 1974. As a result, the Agency was willing to
raise the standard at that time (but only for the 1974 Portland
cement plant standard).
Changes In EPA Procedures
After a series of extensive field tests, EPA determined that
some revisions and clarifications in applying Method 9 were in
order. In evaluating the accuracy of results from qualified ob-
servers following the newly revised Method 9 procedures, EPA
determined that observers trained and certified in accordance
with the procedures prescribed under Method 9 are consistently
able to read opacity with positive errors not exceeding 7.5 per-
cent based on single sets of an average of 24 readings.
Analysis Of Error
The preamble states:
An introductory section was added. This included a discus-
sion of the concept of visible emission reading and de-
scribed the effect of variable viewing conditions. Information
was also presented concerning the accuracy of the method,
noting that the accuracy of the method must be taken into
account when determining possible violations of applicable
opacity standards.
This accuracy information has been widely misinterpreted and
misquoted by defense attorneys and regulatory officials. Knowl-
edgeable observers have no problems with the issue of error
analysis, however.
Averaging Was Introduced To Increase Accuracy
At the time Method 9 was proposed, a commonly used stan-
dard technique for reducing data was to count the number of
observations at or above the standard and to multiply by 15
seconds to determine the amount of violation time (15 seconds
represents the lapse of time during an observation). This viola-
tion time was compared to the time exemption in the rule. At
the time of the Portland cement remand, EPA had not deter-
mined the accuracy of this approach. Consequently, EPA modi-
Method 9 Requirements • 5-7
-------
Notes fied the method to use an averaging approach to ensure the
accuracy of the observations.
The preamble states:
Provisions were added which specify that the determination
of opacity requires averaging 24 readings taken at 15-second
intervals. The purpose for taking 24 readings is both to
extend the averaging time over which the observations are
made and to take sufficient readings to insure acceptable
accuracy.
After taking an average of 20 or more values, statistical accura-
cy is not greatly enhanced by adding more data. Thus, 24
readings over a 6-minute period produces a statistically signifi-
cant average and demonstrates that the plume is not a momen-
tary puff of excess emissions.
This change of method indirectly had an immense impact on
the states that were using the time-aggregation technique. In
accordance with regulatory provisions later promulgated in CFR
part 52.12.(c), federal enforcement required states that do not
clearly specify a method in their State Implementation Plans
(SIPs) to use averaging as the data-reduction technique.
Sun Position Became An Issue
The preamble states:
More specific criteria concerning observer position with
respect to the sun were added. Specifically, the sun must be
within a 140° sector to the observer's back.
Of all the changes in the method, this one increased the accuracy
of the observations the most.
Slant-Angle Considerations Were Introduced
The preamble states:
Criteria concerning an observer's position with respect to
the plume were added. Specific guidance was also provided
for reading emissions from rectangular emission points with
5-8 • Course 325, Visible Emission Evaluation Procedures
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large length-to-width ratios, and for reading emissions from Notes
multiple stacks. In each of these cases, emissions are to be
read across the shortest pathlength.
This section was included to minimize positive bias inherent to
the effect of pathlength on visible emissions observations.
Slant-angle effects occur when the observation pathlength is
longer than it should be. The pathlength is lengthened when an
observer either gets too close to a tall stack or observes a plume
along its line of travel. The best rule of thumb for observing
tall stacks with vertical plumes is to be positioned at least 3
stack heights away, where the slant-angle is 18° or less.
The Issue Of Steam Source Plumes Was
Introduced
The preamble states:
Provisions were added to make clear that opacity of con-
taminated water or steam plumes is to be read at a point
when water does not exist in condensed form. Two specific
instructions are provided: one for the case where opacity
can be observed prior to the formation of the condensed
water plume, and one for the case where opacity is to be
observed after the condensed water plume has dissipated.
For the first time, standardized approaches were included to
eliminate the problems of observing plumes formed by the
condensation of steam or steam plumes.
Smoke Generators Were Standardized
The preamble states:
Specifications were added for the smoke generator used for
qualification of observers so that state or local air pollution
control agency...
EPA wanted to standardize the certification procedure by estab-
lishing criteria for the generators and opacity-measuring equip-
ment used in training and certifying observers.
Method 9 Requirements • 5-9
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Notes Minor Changes To The Method
The current version of Method 9 can be found in the Federal
Standards of Performance for New and Modified Stationary
Sources—Code of Federal Regulations (CFR) Part 60, Appen-
dix A—Reference Methods. Some minor variations to the ba-
sic method are found in specific standards. The method has
essentially been unchanged since its promulgation in 1974, ex-
cept for two minor changes in 1987. The following discussion
reflects the 1987 version of the method.
The method states:
Many stationary sources discharge visible emissions into
the atmosphere; these emissions are usually in the shape of
a plume. This method involves the determination of plume
opacity by qualified observers. The method includes proce-
dures for the training and certification of observers, and
procedures to be used in the field for determination of plume
opacity.
Appearance And Controllable Observational
Variables
The method states:
The appearance of a plume as viewed by an observer de-
pends upon a number of variables, some of which may be
controllable and some of which may not be controllable in
the field. Variables which can be controlled to an extent to
which they no longer exert a significant influence upon
plume appearance include: Angle of the observer with re-
spect to the plume; angle of the observer with respect to the
sun; point of observation of attached and detached steam
plume; and angle of the observer with respect to a plume
emitted from a rectangular stack with a large length to
width ratio. The method includes specific criteria applica-
ble to these variables.
These variables are discussed in the next few pages. It is inter-
esting to note that the controllable variables generally give a
positive bias to any observations if the specific criteria in the
5-10 • Course 325, Visible Emission Evaluation Procedures
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method are not followed. Thus, it is imperative that any observ- Notes
er collecting data for regulatory action follow these require-
ments or be prepared to evaluate the effect of not doing so.
Appearance And Uncontrollable Observational
Variables
The method states:
Other variables which may not be controllable in the field
are luminescence and color contrast between the plume and
the background against which the plume is viewed. These
variables exert an influence upon the appearance of a plume
as viewed by an observer, and can affect the ability of the
observer to accurately assign opacity values to the observed
plume.
Generally speaking, the uncontrollable errors lead to negative
bias in observations. In other words, these errors tend to result
in Method 9 opacity readings that are lower than the actual
opacity of the plume. Although any documented violation that
is influenced by such errors could probably be sustained in
court, the errors also result in "under-enforcement" of opacity
regulations.
High-Contrast Backgrounds
The method states:
Studies of the theory of plume opacity and field studies
have demonstrated that a plume is most visible and presents
the greatest apparent opacity when viewed against a con-
trasting background. It follows from this, and is confirmed
by field trials, that the opacity of a plume, viewed under
conditions where a contrasting 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
plume is viewed under such contrasting conditions.
Defense attorneys often turn the last sentence against observers.
The key word is potential. "Potential for positive error" does
not mean that observations always or even often will be higher
than the actual opacity. An additional series of tests sponsored
Method 9 Requirements -5-11
-------
Notes by EPA determined that the most likely outcome is for observ-
ers to estimate opacity correctly or to underestimate opacity.
Low-Contrast Backgrounds
The method states:
Under conditions presenting a less-contrasting background,
the apparent opacity of a plume is less and approaches zero
as the color and luminescence contrast decrease toward
zero. As a result, significant negative bias and negative
errors can be made when a plume is viewed under less-
contrasting conditions. A negative bias decreases rather than
increases the possibility that a plant operator will be cited
for a violation of opacity standards due to observer error.
Simply put, as the amount of visual information to help deter-
mine plume opacity decreases, negative bias increases. It is
hard to distinguish a black cat at night; likewise, it is hard to
distinguish a white plume against an overcast sky. In the real
world, it is most likely that the observer will encounter factors
that tend to result in negative bias because of low contrast
between the plume and the background. Plumes from tall stacks
must always be evaluated against a blue or cloudy sky in which
the color contrast is low and the luminous contrast is poor.
Positive Error Defined
EPA has on several occasions quantified the errors associated
with Method 9. In the original promulgation, data were present-
ed from a series of field studies conducted by the Agency.
The method states:
Studies have been undertaken to determine the magnitude
of positive errors which can be made by qualified observers
while reading plumes under contrasting conditions and us-
ing 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:
5-12 • Course 325, Visible Emission Evaluation Procedures
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• For black plumes (133 sets at a smoke generator) 100 Notes
percent of the sets 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, and 298 sets at a sulfu-
ric acid plant), 99 percent of the sets were read with a
positive error of less than 7.5-percent opacity; 95 per-
cent were read with a positive error of less than 5-
percent opacity.
Note that black smoke was only slightly easier to evaluate.
Note also that two levels of error are addressed in each set of
results. For black smoke, the reported levels of confidence were
100 and 99 percent. For white smoke, the levels were 99 and 95
percent. These data indicate that there is no single level of error
for Method 9. In addition, note that the method does not ad-
dress negative error at all. EPA is simply addressing the issue
of wrongfully identifying a compliant source as a violator.
Positive Observational Error
The method states:
The positive observational error associated with an average
of twenty-five readings is therefore established. The accura-
cy of the method must be taken into account when deter-
mining possible violations of applicable opacity standards.
The Agency does not define a specific positive observational
error but warns that accuracy must be taken into account. Any
potential negative biases associated with observations should
also be taken into account. A source should not be given a
percentage above the standard as a routine practice, however.
From a practical standpoint, the extent that an observation is
above a standard will go to the weight of the evidence. Other
factors that might be considered in cases in which the opacity
reading is only marginally above the standard are the frequency
and duration of excess emissions and a pattern of degradation
of control-equipment performances.
Method 9 Requirements '5-13
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Notes Principle
The method states:
The opacity of emissions from stationary sources is deter-
mined visually by a qualified observer.
Again, this is a method that involves human observation. The
observer must be certified before completing observations for
record.
Applicability
The method states:
This method is applicable for the determination of the opacity
of emissions from stationary sources pursuant to 60.11 (b)
and for qualifying observers for visually determining opaci-
ty of emissions.
In addition to sources subject to NSPS, other sources are evalu-
ated using Method 9. Often, states incorporate Method 9 into
their SIP rules and regulations by reference. If a state SIP is
unclear as to an exact method or if the cited method has not
gone through formal rulemaking, Section 52.12(c) of CFR Part
52 allows EPA to apply Method 9 in making a compliance
determination. Thus, the observer should be careful to check
the standard to which a source is subject and to determine
whether any other methods apply for observations.
Procedures
The method states:
The observer qualified in accordance with paragraph 3 of
this method shall use the following procedures for visually
determining the opacity of emissions.
An observer must follow specific procedures to complete a
valid visible emission evaluation. These procedures are described
below.
5-14 • Course 325, Visible Emission Evaluation Procedures
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Observer Position Relative To The Sun Notes
One of the most important aspects of visible emissions evalua-
tion is the relative positions of the observer, the sun, and the
plume (see Figure 5-2). If the observer looks toward the sun,
the appearance of the plume is enhanced, resulting in a high
bias.
The method 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.
Figure 5-2. Observer Relationship To The Sun
Adherence to this rule prevents forward scattering of the light
by the plume from interfering with the observation. On an
overcast day when no shadows are observed and the lighting is
diffuse or flat, this rule might not be as important from a scien-
tific standpoint as on a bright, sunny day. Observers might have
trouble defending their positions in court if they disregard the
rule. The best practice for an observer is always to have the sun
at his or her back, even if it is not visible and no shadows are
cast.
Observer Line Of Sight
The method states:
Consistent with maintaining the above requirement, the ob-
server 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
opacity of emissions from rectangular outlets (e.g., roof
monitors, open baghouses, non-circular stacks), approxi-
mately perpendicular to the longer axis of the outlet.
Method 9 Requirements • 5-15
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Notes
Recognizing that sun angle is the most important factor, the
method gives guidance to limit slant-angle effects. Slant-angle
effects occur when the observation pathlength through the plume
is longer than it should be. Pathlength increases when the ob-
server gets too close to a tall stack or observes a plume along its
line of travel (see Figure 5-3).
Apparent
opacity
Apparent
opacity
Figure 5-3. Effect Of Slant Angle On Pathlength And
Apparent Opacity
The best rule for observing tall stacks with vertical plumes is to
take a position at least three stack heights away, where the slant
angle is 18° or less. Under these conditions, the positive error is
less than 1 percent of the true opacity.
When the plume is horizontal, the same effect holds true. Be-
cause of slant angle, observers must take special care in observ-
ing plumes from ships' holds. If the slant angle cannot be
minimized, calculations can be used to negate the effects and
determine the corrected opacity.
Multiple Stacks
Multiple stacks can create plumes that intermingle. The method
states:
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).
5-16 • Course 325, Visible Emission Evaluation Procedures
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If the observer cannot get perpendicular to the line of stacks, he Notes
or she should make sure that no interfering plumes are present.
Sometimes just viewing the plumes before they intermingle
will achieve this goal.
Field Records
The method states:
The observer shall record the name of the plant, emission
location, type of facility, observer's name and affiliation
and the date on a field data sheet. The time, estimated
distance to the emission location, approximate wind direc-
tion, estimated wind speed, description of the sky condi-
tions (presence and color of clouds), and plume background
are recorded on a field data sheet at the time opacity read-
ings are initiated and completed.
This section contains language not present in the 1974 promul-
gation. The method now requires a sketch of the relative posi-
tions of the sun, the source, and the observer. If the observer
uses the form reproduced in this manual and completes all the
entries and the sketch, all the required data will be collected.
Observation Point In The Plume
The method states:
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 provision ensures that the opacity is measured after parti-
cles and gas-phase reactions in the plume have formed. The
provision could, however, cause problems if the plume is mush-
rooming in the atmosphere. Mushrooming occurs when the
plume velocity cannot be maintained in the atmosphere and the
pathlength increases faster than the natural dilution of the plume.
Normally, this is not the case.
Method 9 Requirements -5-17
-------
Notes Attached Steam Plumes
When steam is emitted, cools, and condenses, it forms a steam
plume. Steam is not defined as particulate matter by the Agen-
cy. To address the problem of steam plumes, several modifica-
tions to the rule of observing at the densest part of the plume
are part of the method.
The method states:
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.
Detached Steam Plumes
The method states:
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 key words in those last three sections of the method
that have been discussed, hi the first two, the key word was
shall, while in the third the key word was should. There is no
option in the first two cases. In the last case, however, observa-
tions could be made before steam plume formation, as suggest-
ed, or they could be made after the steam plume re-evaporates.
The key to this decision is to follow the first rule and observe at
that point where the plume is the most dense.
Recording Observations
The method states:
Opacity observations shall be recorded to the nearest 5
percent at 15-second intervals on an observational record
sheet. A minimum of 24 observations shall be recorded.
5-18 • Course 325, Visible Emission Evaluation Procedures
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Each momentary observation recorded shall be deemed to Notes
represent the average opacity of emission for a 15-second
period.
From a technical standpoint, the most important part of this
section concerns making momentary observations. Staring at
the plume reduces the ability of the observer to make an accu-
rate assessment of the opacity.
Data Reduction
The method states:
Opacity shall be determined as an average of 24 consecu-
tive observations recorded at 15-second intervals. Divide
the observations recorded on the record sheet into sets of
24 consecutive observations.
Taken out of context, this section has been used by defense
attorneys to claim that the observer must take the first 6 min-
utes and average them, then the next 6 minutes and average
them, and so on. This is not the case.
The method continues:
A set is composed of any 24 consecutive observations. Sets
need not be consecutive in time and in no case shall two
sets overlap.
This means that any set of observations in the total data set
could contain a violation. A computer is useful in analyzing
possible averages.
Calculation Of Opacity
The method states:
For each set of 24 observations, calculate the average by
summing the opacity of the 24 observations and dividing
this sum by 24. If an applicable standard specifies an aver-
aging time requiring more than 24 observations, calculate
the average for all observations made during the specified
time period. Record the average opacity on a record sheet.
Method 9 Requirements • 5-19
-------
Notes For a 1 -hour data set, there are 217 possible 6-minute aver-
ages that could be calculated using the "rolling average"
calculation technique preferred by EPA.
Qualifications And Testing
General Certification Requirements
The method states:
To receive certification as a qualified observer, a candi-
date must be tested and demonstrate the ability to as-
sign opacity readings in 5 percent increments to 25
different black plumes and 25 different white plumes,
with an error not to exceed 15 percent opacity on any
one reading and an average error not to exceed 7.5
percent opacity in each category. Candidates shall be
tested according to the procedures described in para-
graph 3.2. Smoke generators used pursuant to para-
graph 3.2 shall be equipped with a smoke meter which
meets the requirements of paragraph 3.3.
Period Of Certification
The method states:
The certification shall be valid for a period of 6 months,
at which time the qualification procedure must be re-
peated for an observer to retain certification.
Certification Procedure
The method has specific instructions regarding the certifica-
tion procedure. This portion of Method 9 will be covered in
Lessons 10 and 12.
5-20 • Course 325, Visible Emission Evaluation Procedures
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Review Questions
1. Which readings does EPA consider presumptively valid and correct?
a. Transmissometer readings
b. Opacity readings by Method 9
2. A larger diameter stack will (increase/decrease) observed opacity.
3. True or False? A facility can be fined for exceeding the opacity standard
without additional evidence that the mass emission limit was violated.
4. What is the error that most Method 9-certified observers will not surpass in an
average of a set of 24 readings?
5. Of all the changes in Method 9, which increased accuracy the most?
6. If a detached steam plume is present, at what two places could the opacity be
read?
7. What are some variables that influence the appearance of the plume but are
controllable by the observer?
8. Controllable variables usually give a (positive/negative) bias.
Uncontrollable variables usually give a (positive/negative) bias.
9. EPA determined that the highest likelihood is that an observer will (over-
estimate/underestimate) opacity.
10. Which type of smoke is slightly easier to evaluate, white or black?
11. The sun must be within a degree angle to the observer's back.
12. At three stack heights away, the slant angle is degrees or less, which
gives a positive error of percent or less.
13. occurs when plume velocity cannot be maintained in the
atmosphere.
14. What are the requirements to be certified in Method 9 as a qualified observer?
15. For how long is certification valid ?
Method 9 Requirements • 5-21
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Lesson 6
Other Methods
-------
Other Methods
Method 22—Visual Determination of
Fugitive Emissions From Material-
Processing Sources
Method 22 differs from Method 9 in several ways. Method 22 Notes
is a qualitative method; Method 9 is quantitative. This means
that whereas Method 22 determines the presence (and duration)
or absence of visible emissions, Method 9 determines the opac-
ity of the emissions. Method 22 is most often used to deter-
mine visually the presence and/or duration of fugitive emissions
(i.e., emissions not emitted directly from a process stack or
duct). Method 9 is also used to measure the opacity level of
fugitive emissions.
Fugitive emissions include emissions that:
• Escape capture by process equipment exhaust hoods.
• Are emitted during material transfer.
• Are emitted from buildings housing material-
processing or material-handling equipment.
• Are emitted directly from process equipment.
Method 22 is also used to determine the duration of visible
smoke emissions from flares used to combust process waste
gas. Method 22 has been used successfully in litigation con-
cerning visible emissions that contained asbestos.
Method 22 determines the amount of time that any visible
emissions occur during the observation period (i.e., the accu-
mulated emissions time). Because the procedure requires de-
termining only whether a visible emission occurs and does not
require determining opacity levels, observer certification ac-
cording to the procedures of Method 9 is not required. The
observer must know the general procedures for determining the
presence of visible emissions, however. At a minimum, the
Other Methods • 6-3
-------
Notes observer must be trained and knowledgeable about how the
visibility of emissions is affected by background contrast,
ambient lighting, observer position relative to lighting, wind,
and the presence of uncombined water (condensing water va-
por). This training is available in written materials or from
Method 9 certification course lectures.
Applicability And Principle
Section 2.1, Applicability, states:
This method applies to the determination of the frequency
of fugitive emissions from stationary sources (located indoors
or outdoors) when specified as the test method for
determining compliance with new source performance
standards.
This method also applies for determining the frequency of
visible smoke emissions from flares.
The method's principle is that fugitive emissions produced dur-
ing material processing, handling, and transfer operations, or
smoke emissions from flares, are visually determined by an
observer without using instruments.
The method contains a series of definitions, including:
Emission frequency—the percentage of time that emissions are
visible during the observation period.
Emission time—the accumulated amount of time that emis-
sions are visible during the observation period.
Fugitive emissions—a pollutant that is generated by an affected
facility, not collected by a capture system, and released to the
atmosphere.
Smoke emissions—a pollutant generated by combustion in a
flare and occurring immediately downstream of the flame.
Smoke occurring in the flame, but not downstream of the flame,
is not considered a smoke emission.
Observation period—an accumulated time period during which
observations are conducted, not to be less than the period speci-
fied in the applicable regulation.
6-4 • Course 325, Visible Emission Evaluation Procedures
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Equipment Notes
Several pieces of equipment are required for Method 22, de-
pending on the location of the source.
Section 4.1 Stopwatches, states:
Accumulative type with unit divisions of at least 0.5 sec-
onds; two required.
Many liquid-crystal-type stopwatches do not have the time-
accumulation function. Almost all mechanical stopwatches have
this function. Mechanical stopwatches are suitable for Method
22 because great accuracy is not required.
The method states:
4.2 Light Meter. Light meter capable of measuring illumi-
nance in the 50- to 200-lux range; required for indoor ob-
servations only.
This type of light meter is available from industrial lighting
companies, some photographic suppliers, and industrial safety
equipment suppliers. These meters are incident light meters,
not reflected light meters.
Procedure
The method states:
5.1 Position. Survey the affected facility or building or
structure housing the process to be observed and determine
the locations of potential emissions. If the affected facility
is located inside a building, determine an observation loca-
tion that is consistent with the requirements of the applica-
ble regulation (i.e., outside observation of emissions escaping
the building/structure or inside observation of emissions
directly emitted from the affected facility process unit).
Then select a position that enables a clear view of the po-
tential emission point(s) of the affected facility or of the
building or structure housing the affected facility, as appro-
priate for the applicable subpart.
Other Methods • 6-5
-------
Notes Several points and times might need to be selected for .this
observation if the building is large or if there are numerous
process-emissions points.
The method states:
A position at least 15 feet, but not more than 0.25 miles,
from the emission source is recommended. For outdoor
locations, select a position where the sun is not directly in
the observer's eyes.
This differs from Method 9 in that a specific requirement of
distance is part of the method. Also, the Method 9 requirement
of the sun at the observer's back has been relaxed. The sun
must simply be kept from being directly in the observer's line
of sight.
Field Records
Two sets of field-record forms are supplied with the method,
one for outdoor locations and the other for indoor locations.
The principal difference is the determination of minimum light-
ing in the indoor location.
The method states:
5.2.1 Outdoor Location. Record the following information
on the field data sheet: company name, industry, process
unit, observer's name, observer'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 to the source and the sun.
Indicate the potential and actual emission points on the
sketch.
5.2.2 Indoor Location. Record the following information
on the field data sheet: company name, industry, process
unit, observer's name, observer's affiliation, and date.
Record as appropriate the type, location, and intensity of
lighting on the data sheet. Sketch the process unit being
observed and note observer location relative to the source.
6-6 • Course 325, Visible Emission Evaluation Procedures
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Indicate the potential and actual fugitive emission points on Notes
the sketch.
One of the most difficult problems in implementing Method 22
is determining whether lighting requirements are being met. It
is important that the measured lighting be the lighting at the
location of the emissions, not just the lighting at the observer's
location.
The method states:
5.3 Indoor Lighting Requirements. For indoor locations,
use a light meter to measure the level of illumination at a
location as close to the emission source(s) as is feasible.
An illumination of greater than 100 lux (10 foot candles) is
considered necessary for proper application of this method.
An illumination of 100 lux is a fair amount of light. The
method is not designed to be used under dim lighting condi-
tions.
The method states:
5.4 Observations. Record the clock time when observa-
tions begin. Use one stopwatch to monitor the duration of
the observation period; start this stopwatch when the obser-
vation period begins. If the observation period is divided
into two or more segments by process shutdowns or ob-
server rest breaks, stop the stopwatch when a break begins
and restart it without resetting when the break ends.
Because the emissions are going to be observed continuously,
the observer must rest his or her eyes. To maintain a complete
record, record the times of the breaks on the field-record form.
The method states:
Stop the stopwatch at the end of the observation period.
The accumulated time indicated by this stopwatch is the
duration of the observation period. When the observation
period is completed, record the clock time.
During the observation period, continuously watch the emis-
sion source. When an emission begins (condensed water vapor
is not considered an emission), start the second accumulative
Other Methods • 6-7
-------
Notes stopwatch; stop the watch when the emission stops. Continue
this procedure for the entire observation period. The accumu-
lated elapsed time on this stopwatch is the total time that emis-
sions were visible during the observation period (i.e., the
emission time).
The method states:
5.4.1 Observation Period. Choose an observation period of
sufficient length to meet the requirements for determining
compliance with the emission regulation in the applicable
subpart. 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 to indicate noncompliance (based
on the specified observation period) is observed in a shorter
time period.
In other words, if the regulation prohibits emissions for more
than 6 minutes in any hour, then observations can (optionally)
be stopped after an emission time of 6 minutes is exceeded. At
this point, a violation has occurred. Similarly, when the regula-
tion is expressed as an emissions frequency and the regulation
prohibits emissions for greater than 10 percent of the time in
any hour, then observations can (optionally) be terminated after
6 minutes of emissions are observed, because 6 minutes is 10
percent of an hour. Again, this represents a violation. If an
observer is proving compliance, however, the observation must
continue for the full time length of the observation period im-
plied or stated in the regulation.
In any case, the observation period shall not be less than 6
minutes. If the process operation is intermittent or cyclic, the
best practice is for the observation period to coincide with the
process cycle.
The method states:
5.4.2 Observer Rest Breaks. Do not observe emissions
continuously for a period of more than 15 to 20 minutes
without taking a rest break. For sources requiring observa-
tion periods of greater than 20 minutes, the observer shall
take a break of not less than 5 minutes and not more than
6-8 • Course 325, Visible Emission Evaluation Procedures
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10 minutes after every 15 to 20 minutes of observation. If
continuous observations are desired for extended time peri-
ods, two observers can alternate between making observa-
tions and taking breaks.
This requirement is important and cannot be over-stressed. Eye
fatigue sets in quickly. Under subpart 000 of the Nonmetallic
Mineral Regulations, lengthy observations might be needed to
demonstrate compliance or to certify that the source is meeting
the standards. The observer must consider the rest-break re-
quirement when planning the observation period.
The method states:
5.4.3 Visual Interference. Occasionally, fugitive emissions
from sources other than the affected facility (e.g., road dust)
may prevent a clear view of the affected facility. This may
particularly be a problem during periods of high wind. If
the view of the potential emission points is obscured to
such a degree that the observer questions the validity of
continuing observations, then the observations are terminat-
ed, and the observer clearly notes this fact on the data form.
Generally, because the lighting requirements are more relaxed
than those for Method 9, an experienced or creative observer
can find a location that does not have this problem.
Recording Observations
The method states:
Record the accumulated time of the observation period on
the data sheet as the observation period duration. Record
the accumulated time emissions were observed on the data
sheet as the emission time. Record the clock time the
observation period began and ended, as well as the clock
time any observer breaks began and ended.
Calculations For Emission Frequency Regulations
The method states:
If the applicable subpart requires that the emission rate be
expressed as an emission frequency (in percent), determine
Notes
Other Methods • 6-9
-------
Notes this value as follows: Divide the accumulated emission time
(in seconds) by the duration of the observation period (in
seconds) or by any minimum observation period required
in the applicable subpart, if the actual observation period is
less than the required period, and multiply this quotient by
100.
This calculation is not necessary if the regulation has specific
time exemptions for specific observation periods, such as 3
minutes in 1 hour.
Method 9A
The LIDAR method is designated as Method 9A. This instru-
mental method uses a lidar, a device that emits pulsed laser
light, to determine plume opacity. It has several advantages
over the visible emissions observer method.
• It is not limited to daylight hours.
• It is not a subjective method.
• Under proper conditions, it can be slightly more accu-
rate than Method 9.
Method Of Operation
The lidar projects a powerful red laser through the plume. Light
is reflected back from particles in the air before the laser light
hits the plume. This reflection gives the unattenuated signal
that is recorded electronically. The light that has gone through
the plume then bounces off particles in the ambient air on the
other side of the plume and, on the way back to the receiver, is
attenuated by the plume. A comparison is made between the
signals coming back from the particles on the near side and on
the far side of the plume. The comparison is corrected for the
inverse square loss due to distance. Opacity is calculated from
the transmission of light through the plume.
Disadvantages
As with any method, Method 9A has disadvantages as well as
advantages. Some of the disadvantages are:
• The method requires much-more-expensive equipment
than Method 9.
6-10 • Course 325, Visible Emission Evaluation Procedures
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Method 9A requires more staff to operate and a far
higher level of training than does Method 9.
Minimum distances are required between the lidar, the
source, and background objects. Also, safety proce-
dures must be followed carefully.
The lidar assumes that particle density in the air is
uniformly distributed. If additional particles are behind
the plume reflecting light, the true opacity will be higher
than the measured value.
Notes
SIP Methods
Many of the SIP rules predate the 1974 promulgation of Meth-
od 9. Additionally, because Method 9 introduced the concept
of averaging over a 6-minute period, there are times when the
SIP rule seems to be at variance with Method 9. EPA recog-
nized this problem when it stated the following in the pream-
ble:
Many state and local air pollution control agencies use a
different approach in enforcing opacity standards than the
six-minute averaging period specified in this revision to
Method 9. EPA recognizes that certain types of opacity
violations that are intermittent in nature require a different
approach in applying the opacity standards than this revi-
sion to Method 9.
EPA has completed extensive testing of the alternate proce-
dures as promised in the preamble to Method 9, collecting
65,000 data points in field studies of observers reading against
a smoke generator.
Many SIP regulations vary from Method 9 in that they:
• Count the number of violations of the standard.
• Multiply that number by 15 so that the total time of
violation is accumulated or aggregated.
• Divide the result by 60 to determine the number of
minutes.
• Compare the number of minutes of violation with the
number of minutes allowable in the standard (the time
exemption).
Other Methods -6-11
-------
Notes If a state has gone through formal rulemaking and promulga-
tion of the test method, the above regulations would be used to
enforce the SIP.
If the applicable test method is not clearly stated, or if the state
has not gone through formal rulemaking, a common practice is
to use Method 9 procedures. That means a minimum of a 6-
minute average of 24 consecutive readings, even if the standard
is for 3 minutes in 1 hour.
EPA is remedying this problem by promulgating methods 203 A,
203B, and 203C, which provide for several different reduction
techniques, including non-averaging. This will allow the regu-
lator to choose the method implied by the regulation.
6-72 • Course 325, Visible Emission Evaluation Procedures
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I
Review Questions
1. Whereas Method 9 is quantitative, Method 22 is
2. Observer certification (is/is not) required for Method 22.
3. Define fugitive emissions.
4. How does Method 22 differ from Method 9 with respect to sun angle?
How does it differ with respect to distance from source?
5. How great must the illumination be for proper use of Method 22?
6. An observer cannot observe emissions for a period greater than 15 to 20
minutes without taking a .
7. The LIDAR method is designated as Method .
8. List three advantages Method 9A has over Method 9.
9. List three disadvantages of Method 9 A compared with Method 9.
Other Methods • 6-13
-------
Lesson 7
Special Field Problems
-------
Special Field Problems
During visible emissions evaluations, observers might encoun- Notes
ter viewing problems that are not addressed by Method 9, or
they might have difficulty determining whether the require-
ments are being met. The most common problems encountered
by observers are:
• Predicting steam plume formation
• Line-of-sight problems (including slant angle)
• Complex plumes
• Extreme distances
• Nighttime observations
Predicting Steam Plume Formation
Visible steam plumes are caused by the condensation of water
vapor in exhaust streams. Five primary factors affect the for-
mation of steam plumes:
• Dry-bulb temperature
• Wet-bulb temperature
• Relative humidity
• Absolute humidity
• Specific volume
Dry-bulb temperature is the actual ambient temperature. This
temperature is represented on the horizontal axis of the psy-
chrometric chart (see Figure 7-1) on the next page.
Wet-bulb temperature is the temperature indicated by a "wet-
bulb" thermometer (a regular thermometer that has its bulb
covered with a wet wick and is exposed to a moving air stream).
This temperature (saturation temperature) is represented by the
curved axis on the left side of the psychrometric chart.
Special Field Problems • 7-3
-------
Notes
SUMFUM MOOING OMOT
Figure 7-1. Psychrometric Chart
Relative humidity is the ratio of the amount of water vapor
actually present in the air compared with the greatest amount
possible at the same temperature. These values are represented
by the set of curved lines originating in the lower left portion of
the psychrometric chart.
Absolute humidity (humidity ratio) is the amount of water va-
por present in a unit of air. This value, expressed as grains per
pound or pound per pound, is represented on the vertical axis of
the psychrometric chart.
Specific volume is the volume occupied by a unit mass of air,
expressed as cubic feet per pound. This value is represented on
the psychrometric chart by the diagonal lines running from
lower right to upper left.
The relationships shown in the psychrometric chart differ with
changes in barometric pressure. The chart included in this sec-
tion is for a barometric pressure of 29.92 inches of mercury.
Therefore, with use of the wet-bulb/dry-bulb technique, if the
actual pressure is less than about 29.5 inches of mercury, the
humidity ratio should be calculated from an equation (see be-
low) and not from the chart.
The psychrometric chart shown in Figure 7-1 is a graphical
representation of the five atmospheric conditions just discussed.
This type of chart can be used in conjunction with the follow-
ing simple equation to predict the formation of a steam plume.
HR =
0.62 (MO)
\-MC
HR = Humidity ratio (pound water/pound dry air)
MC - Moisture content expressed as a decimal
7-4 • Course 325, Visible Emission Evaluation Procedures
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Plotting the values for any two of the five atmospheric proper- Notes
ties determines the values for the remaining three properties.
For example, by measuring the wet-bulb and dry-bulb tempera-
tures with a sling, the relative humidity, the absolute humidity,
and the specific volume of the air can be determined. The point
on the psychrometric chart where the plotted values fall is called
the "state point" or "state condition." This describes the current
condition of the ambient air or of the stack emission itself.
To predict the occurrence of a visible steam plume, both the
ambient air conditions and the stack gas conditions must be
known (or estimated), and the state conditions must be located
or plotted on the psychrometric chart. The change of the ex-
haust gas from the stack state conditions to the ambient air state
will be accompanied by a visible steam plume if any portion of
the line connecting the two points on the chart lies to the left of
the 100-percent relative humidity line. The visible steam plume
will be caused by the condensation of the water vapor present
in the exhaust stream.
It is relatively simple to obtain the state point for the ambient
air conditions. The wet-bulb and dry-bulb temperatures, which
will determine a unique state point, can be measured with a
sling psychrometer. Often, the only data available for determining
the state point of the stack gas are the dry-bulb temperature and
moisture content of the exhaust gas stream. A relationship
exists between the moisture content and the humidity ratio (or
absolute humidity), however, as shown in the following equation:
_ 0.62(MQ
l-MC
where:
HR = humidity ratio, in water
vapor per pound of dry air
MC = percentage moisture content,
expressed as a decimal
The following sample problem demonstrates the use of this
equation.
Special Field Problems • 7-5
-------
Notes Given:
Ambient conditions
Dry-bulb temperature = 70°F
Wet-bulb temperature = 60°F
Barometric pressure = 29.92 in Hg
Effluent gas conditions
Dry-bulb temperature = 160°F
1 f O
Moisture content = —'-— = 0.168
100
Find:
1. Ambient relative humidity
2. Exhaust gas humidity ratio
Determine whether or not water will condense (i.e., whether a
steam plume will form).
Solution:
Plot ambient wet-bulb and dry-bulb temperatures.
Ambient relative humidity = 55%
Exhaust gas humidity ratio = HR
0.62 (MQ
HR= —-
1-AfC
0.62(0.168)
1-0.168
= 0.125 pound water/pound dry air
Plot humidity ratio and stack dry-bulb temperature. Connect
the ambient state point and stack gas state point with a straight
line. The line crosses the 100-percent relative humidity line;
hence, a water vapor plume will be visible.
When the wet-bulb/dry-bulb technique is used and the baro-
metric pressure is less than 29.5 inches of mercury, use the
following equations to calculate the vapor pressure (VP) from
the saturated vapor pressure (SVP) and then to determine the
final moisture content (MQ.
7-6 • Course 325, Visible Emission Evaluation Procedures
-------
Notes
VP = SVP-(3.51x\0^(PJ(TJ-TJ
where:
SVP = Saturated vapor pressure (inches of mecury)
at wet-bulb temperature
Td = Dry-bulb temperature, °F
Tv = Wet-bulb temperature,0?
VP
where: "*
VP = Vapor pressure of H2O
P = Barometric pressure
Line-Of-Sight Problems
Method 9 requires that the plume be observed across the nar-
row axis:
The observer shall, as much as possible, make his observations
from a position so that his line of vision is approximately
perpendicular to the plume direction. When observing opacity
of emissions from rectangular outlets (e.g., roof monitors, open
baghouses, noncircular stacks), the observer shall make his
observations approximately perpendicular to the longer axis of
the outlet. (See Figure 7-2(a).)
Line of sight
I Observer
Sun
m
(a) " (b)
Figure 7-2. Line-Of-Sight Guidelines
Special Field Problems • 7-7
-------
Notes The observer should be situated so that his sight line crosses
only one plume diameter. (See Figure 7-2(b).) An observation
will be positively biased if it is made through a longer visual
pathlength than is appropriate. The usual guidance to eliminate
this problem is to observe the plume from at least 3 stack
lengths from the source. At 3 stack lengths, the view deviates
about 18° from the line of sight and will make a 1-percent
positive bias in the observation if the opacity is 20-percent. For
angles less than 18°, the adjustment is relatively insignificant
and can be ignored.
In rare cases, the observer has no choice but to be relatively
close to the stack so that the sight line is up through the plume
rather than across it. This extended sight pathlength through the
plume should be acknowledged and the individual data values
adjusted mathematically in the final data report to show the
increase in opacity reading due to the longer pathlength. These
adjusted opacity readings should be used in demonstrating that
averages exceed the standard.
Figure 7-3 shows how the slant angle varies inversely with
distance from an elevated source. As an observer moves closer
to the base of the stack, the angle of sight and the visual path-
length through the plume both increase. An increased visual
pathlength through the plume causes an increased opacity read-
ing even though the actual cross-plume opacity remains con-
stant. This situation applies only when the opacity is read
through a vertically rising plume and the observer is on the
same plane as the base of the stack.
Figure 7-3. Slant Angle
7-8 • Course 325, Visible Emission Evaluation Procedures
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The actual opacity can be calculated from the observed opacity
if the slant angle is known or if the height of the stack and the
distance from the observer to the base of the stack are known.
Notes
Height of
stack
Distance from observer
to base of stack
Figure 7-4. Information Needed To Calculate Actual
Opacity From Observed Opacity
Method 1 (slant angle is known):
1 -
= T
100
- o
where:
Oo - observed opacity in percent
T = observed transmittance
F = cosine of slant angle
Oc = corrected opacity in percent
Method 2 (distances are known):
F =
F
where:
F = cosine of slant angle
Y = distance from observer to stack
H = height of stack
Special Field Problems • 7-9
-------
Notes (0)
1 -—^-
100
(1-F) xlOO = Oc
where:
Oo = observed opacity in percent
T = observed transmittance
F = cosine of slant angle
Oc = corrected opacity in percent
Note: Because the correction is a power function, the correc-
tion must be made on each opacity reading before the value is
used for calculations. The correction procedure should never
be performed on the reduced (averaged) data.
Table 7-1 on the next page presents opacity data values correct-
ed for various slant angles. To use the table, first locate the
measured opacity value along the left side of the table. Follow
this row across to the column under the slant angle recorded for
the observation. The value of the intersection of the measured-
opacity row and the slant-angle column is the actual opacity for
that observation. For example, if the measured opacity were 75
and the slant angle were 40, the actual opacity would be 65.
Complex Plumes
Water Retention On Particles
At some facilities, observers are confronted with plumes of
complex mixtures of contaminated water vapor and other con-
densable or reactive materials. Sometimes the condensed mate-
rial seems to be attached to fine particles. When the plume is
observed through binoculars, it is clear that the condensed wa-
ter or "steam" does not simply dissipate sharply, as it does in
many sources. Instead, the free water not attached to particles
dissipates, as do classic steam plumes, but a large amount of
water is retained on particles, giving the appearance of steam
past the point of the "steam break." After viewing the source
through binoculars periodically, observers will learn to recog-
nize this problem without relying on binoculars. This situation
can be observed from both the correct viewing angle in relation
7-10 • Course 325, Visible Emission Evaluation Procedures
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Table 7-1. Opacity Values Adjusted For Increased
Pathlength Due To Slant Angle
Measured
Opacity
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Slant Angle, degrees
0
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
10
95
90
85
80
75
70
64
59
55
50
45
40
35
30
25
20
15
10
5
0
20
94
89
83
78
73
68
63
58
53
48
43
38
33
29
24
19
14
9
4
0
30
93
86
81
75
70
65
60
55
50
45
40
36
31
27
22
18
13
9
4
0
40
90
83
77
71
65
60
55
50
46
41
37
32
28
24
20
16
12
8
3
0
50
85
77
71
65
59
54
49
45
40
36
32
28
24
21
17
13
10
7
3
0
60
78
68
62
55
50
45
41
37
33
29
26
23
19
16
13
11
8
5
3
0
Special Field Problems • 7-11
-------
Notes to the sun and the incorrect viewing angle (facing into the sun).
When the observer views the plume from the incorrect angle by
facing into the sun, a more qualitative assessment of the plume
can be made. The observer sees the first "steam" break more
clearly and also sees the lingering plume of water and particles.
The water and particulate matter plume will change in texture
as the water evaporates until the plume becomes essentially all
particles. Using relative plume heights along the plume to
determine the appropriate viewing location, the observer should
view the same location in the plume from the correct viewing
position (sun at back). Observations should be made after the
point of water evaporation in full accordance with Method 9.
Condensation And Reaction Plumes
Some gases can be mixed together under dry conditions with-
out reacting, but when these same gases are mixed in the pres-
ence of water droplets, the two compounds can react to generate
particulate matter. Usually these compounds react via ionic
bonding, and the product dissolves in the water droplet. Subse-
quently, the water droplets evaporate, and a particulate matter
plume remains. For example, when sulfur oxides, ammonia
gases, and water vapor are in the same gas stream, the sulfur
dioxide and ammonia react on water droplet surfaces and form
dissolved ammonium sulfate. The water evaporates back into
the atmosphere, leaving ammonium sulfate particles in the
plume. This reaction can occur in exhaust gases from cement
plant kilns.
Similar reactions occur in other industries, and plumes from
these reactions can cause viewing problems. Normally, when
observing a detached plume, the observer will make the obser-
vation between the stack outlet and the condensing plume, as
suggested by Method 9. If the material condensing or reacting
out is of interest, however, the observation should be made
after the steam plume dissipates, as shown in Figure 7-5.
7-72 • Course 325, Visible Emission Evaluation Procedures
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Read here Normally read Optional reading Notes
here point
Figure 7-5. Reading Detached Steam Plumes
Extreme Distances
In some guidance documents, EPA has stated that a quarter of a
mile is the maximum suggested viewing distance. In some
cases, however, such as during the observation of tall stacks,
that limit must be exceeded, particularly when the source layout
is such that it is impossible to get correct sun positions at
certain times of day or if access is difficult, unsafe, denied, or
inadvisable because the observation must be candid.
The quarter-mile viewing distance prevents intervening haze
from lowering the contrast between the observer and the source
and background and consequently limits the corresponding neg-
ative bias in observations. Also, the quarter-mile viewing dis-
tance helps the observer get a clear view of the plume.
Binoculars can shorten the apparent distance to the source, but
this method should be used with care, and the general rule of
certifying and observing with the same equipment should be
followed.
Nighttime Observations
Little long-term use of visible emissions observations at night
has been documented except in California, hi certain areas of
the country, however, regulatory personnel and in some cases
industry personnel must be able to evaluate the opacity of night-
time visible emissions accurately, because:
Special Field Problems • 7-13
-------
Notes • Areas in the more-northern parts of the United States,
such as Alaska, Maine, and those states at the northern
border, have short days during the winter months.
• Some industries, because of the nature of their opera-
tions, incinerate during the less-busy evening hours or
second shift.
• Some industries might try to circumvent regulations by
operating certain processes at night or under reduced
controls. (Soot blowing is a common example.)
• In states where industries are required to submit opaci-
ty data from an opacity monitor, human observers are
allowed during monitor downtime, which might be at
night.
For years, California has routinely provided opportunities for
readers to become certified in night viewing and to cite viola-
tions based on night observations. A number of other states are
considering adoption of similar night observation and certifica-
tion programs.
Several agencies have experimented with nighttime VE obser-
vations. In the early 1970s, EPA Region III certified an ob-
server using a starlight scope. This instrument's method of
operation actually distorts emission observations. The starlight
scope amplifies light, and although this amplification helps the
observer see the plume, it does not help judge opacity. Similar
tests with infrared systems provided flawed results, because the
exhaust gases were at an elevated temperature. Also, infrared
devices can "see" through the smoke because of particle-size
and wavelength-of-light considerations. Because visibility is
not opacity, neither the starlight scope nor an infrared system is
recommended.
Usually, there is enough natural light at night for an observer to
see a plume. EPA has determined that an observer certified in
Method 9 at night can estimate the opacity from a source at
night with the same accuracy as in daylight. In fact, by using
proper techniques, a trained and certified observer can assign
an accurate value to the opacity of a source under many condi-
tions.
7-14 • Course 325, Visible Emission Evaluation Procedures
-------
Observers must be trained and certified to observe plumes at Notes
night by taking and passing nighttime field tests before observ-
ing for record. The following guidelines are recommended for
nighttime viewing:
• Conduct observations on a night clear of fog.
• Maintain night vision by avoiding light.
• Select a light behind the source:
• A blue-white star is excellent
• A low-power incandescent light is good
• High-intensity lights should be avoided
• Sodium or mercury arc lights should be avoided
• Colored lights should be avoided
• View the light alternately through the plume and beside
the plume.
• Determine opacity in the same way as during daylight
hours.
Special Field Problems -7-15
-------
Review Questions
1. The psychrometric chart is a graphical representation of what five variables?
2. Give a brief definition of the five variables from question 1.
3. What is the least number of these five properties that must be known in order
to determine them all?
4. The _____ is the point on the psychrometric chart that describes the
current condition of the ambient air or stack emission.
5. The change of the exhaust gas from the stack state conditions to the ambient air
conditions (will/will not) be accompanied by a visible steam
plume if the line connecting the two points on the chart lies completely to the
right of the 100-percent relative humidity line.
6. When observing a rectangular outlet, the observer should be perpendicular to
the (long/short) axis of the outlet.
7. Which observer would have a greater slant angle?
a. An observer 40 feet away from a 10-foot stack.
b. An observer 100 feet away from a 75-foot stack.
8. Given:
Ambient Air Conditions:
Dry-bulb temperature: 80°F
Wet-bulb temperature: 70°F
Barometric pressure: 29.90 in Hg
Stack Emission Conditions
Dry-bulb temperature: 170°F
Moisture content: 16.2%
Find:
Ambient relative humidity
Exhaust gas humidity ratio
Will a steam plume form?_
9. If an observer is less than 3 stack lengths away, he or she will perceive an
7-76 • Course 325, Visible Emission Evaluation Procedures
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Review Questions (cont.)
10. Given:
Slant angle = 30°
Observed opacity = 25%
Calculate the corrected opacity (use the chart on page 7-11).
11. Given:
Observed opacity = 40%
Height of stack = 100 feet
Distance from observer to stack = 60 feet
Calculate the corrected opacity.
12. What kind of bias is present if an observer is less than 3 stack lengths away?
13. A plume in which water attaches to fine particulate matter is a
14. In what way can an observer determine where the steam break is in a
complex plume?
15. What would happen if sulfur oxides and ammonia were present in a steam
plume? What kind of plume is this?
16. EPA has suggested that the maximum distance an observer should view from is
17. An observer observing a stack from greater than 0.5 mile might have a (positive/
negative) bias because of intervening .
18. List three reasons nighttime observation might be used.
Special Field Problems -7-17
-------
Lesson 8
Documentation
-------
Documentation
Under the Clean Air Act of 1970, violations of visible emission
standards from either an NSPS or a SIP could result in a fine
of up to $25,000. A violation can be compared to a speeding
ticket. Someone who receives a speeding ticket might have a
lawyer look at the ticket to determine if the documentation is
correct. If it is not, they might have a chance to beat the ticket
in court. The same concept holds true for opacity violations.
Industry is motivated to scrutinize the visible emissions data
on a form for error because of the size of the fines. Court cases
have been lost or dropped because of poor documentation of
opacity violations. Observers in the field simply do not always
pay enough attention to the details necessary for litigating a
violation successfully. Observers can prevent possible
challenges during deposition processes and in court by properly
documenting the visible emissions they observe.
Initial use of Method 9 demonstrated that more documentation
was needed. The example form and documentation included
in the Federal Register with the Method 9 procedure are not
always adequate to determine the compliance status of sources
subject to opacity standards. A new visible emission
observation (VEO) form was developed after a review of the
opacity forms that had been used in EPA Regional Offices and
in state and local air quality control agencies. The new form
includes the data required by Method 9 plus additional
descriptive information pertaining to observation conditions.
The VEO form is a three-part form with one original and two
carbon copies. The form should be completed and signed on-
site so that the observer can give the source immediate
documentation of the inspection. The original goes to the
observing agency's files, the first copy is for the VE observer's
file, and the second copy is for the facility. Waterproof black
ink should be used on these forms. Unless an item is specifically
designated as optional, the observer must provide an entry in
all sections.
Notes
Documentation • 8-3
-------
Notes The next section of this lesson discusses each of the 10 major
parts of the VEO form and each data element found on the
form. The discussion includes an explanation of each section's
purpose and each data element. A description of the type of
information being sought and, in some cases, examples of
appropriate entries are included. An example of a completed
VEO form is at the end of this lesson.
Company Identification
This section of the form provides information that identifies
the company and gives the observer information on contacting
the company.
Company name—Include the facility's complete name.
To give positive identification of the facility, include the
parent company name, division, or subsidiary name.
Street address—Indicate the street address of the facility
(not the mailing address or the home office address) so that
the exact physical location of the source is known. If
necessary, the mailing address or home office address can
be listed elsewhere.
Process And Control Equipment
This section of the form includes:
• A description of the process and control equipment.
• Indication of current process operating capacity or
mode.
• Operational status of control equipment.
Note: This section includes information that can be obtained
from a plant official. Because plant officials might consider
production rate or other process information proprietary, the
inspector should specifically inform them that they have a
right to request that this information be submitted subject to
the confidential business information (CBI) provisions of
40 CFR Part 2, Subpart B.
8-4 • Course 325. Visible Emission Evaluation Procedures
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Process equipment—Enter a description that clearly
identifies the process equipment. Also enter the type of
facility that emits the plume or emissions to be read. The
description should be brief but should include as much
information as possible.
Operating mode—Depending on the type of process
equipment used, this information can vary. Some examples
of the types of entries include:
• Quantification of the current operating rate.
• Description of the portion of a batch-type process for
which the emission opacity is being read.
• An explanation of how the equipment is currently
operating, such as "upset conditions," "startup," or
"shutdown."
• "90-percent capacity" for a boiler.
• "85-percent production rate" for the shakeout area of
a grey iron foundry.
For a metallurgical furnace, entries should include the exact
part of the process cycle for which readings are being taken,
such as "charging" or "tapping." Usually, this information
will have to be obtained from a plant official.
Control equipment—Specify the type(s) of control
equipment used in the system after the process equipment
(e.g.. hot-side electrostatic precipitator).
Operating mode—Two items of information should be in
this section.
• The manner in which the control equipment is being
operated at the time of the opacity observations (e.g.,
one field of eight tripped on ESP, scrubber operating
without water, shutdown, offline).
• The operating mode (e.g., automatic, manual, by-
pass). This information should be obtained from a
plant official.
Notes
Documentation • 8-5
-------
Notes Emission Point Identification
This section of the form identifies the emission point and its
specific relationship to the observer's position. Use consistent
units for distances and heights in this section of the form.
Describe emission point—Indicate the type of emission
point and its physical characteristics. The description must
be specific enough so that the emission outlet that was
observed can be distinguished from all others at the source.
The description of the type of emission point should address
whether it is one of the following:
• A specifically designated outlet, such as a stack, a
vent, or a roof monitor (with confined emissions).
• An emission source with unconfmed emissions,
such as a storage pile, a chemical tank, or a non-
ducted material-handling operation.
The description of the physical characteristics of the emission
point should include:
• The appearance (such as color, texture, etc.).
• The geometry (such as size, shape, etc.) of the stack
or other outlet.
• The emission point's location in relation to other
recognizable facility landmarks.
Note any special identification codes agency or plant operating
personnel use to identify a particular stack or outlet with the
description and record the source of the code. Do not use a
special identification code by itself to describe the emission
point, because the code could be incorrect or might require a
secondary reference. Special identification codes, in addition
to a description of the emission point, an identification of the
process equipment, and a description of the control equipment
will ensure proper identification of the stack or outlet.
8-6 • Course 325. Visible Emission Evaluation Procedures
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Height above ground level—Indicate the vertical distance
from the ground to the emission point. There are several
ways to obtain this information.
• It can be found in agency files, engineering drawings,
or computer printouts (such as National Emissions
Data System [NEDS] printouts).
• It can be obtained by using a combination of a range-
finder and an Abney level or clinometer.
• It can be estimated.
The observer should record what method wasusedto determine
the height.
Height relative to observer—Indicate a height estimate of
the emission outlet above the observer's position. This
measurement shows the observer's position in relation to the
outlet's base (i.e., higher or lower than the base). This
information is necessary if slant-angle calculations are
performed. This parameter should be recorded in the same
units as those used to indicate height above ground level.
Distance from observer—Record the distance from the
point of observation to the emission outlet. The distance can
be measured with a rangefinder, or a map can be used to
estimate the distance. The observer should use the same
units that were used to record the two height measurements.
This measurement of "distance from observer" must be
reasonably accurate when the observer is close to the stack
(within three stack heights). Accuracy is important because
this measurement might be used in conjunction with the
outlet height relative to the observer to determine the slant
angle at which the observations were made (see Figure 8-1). A
precise determination of the slant angle is needed to calculate
the positive bias. This bias is inherent in opacity readings
made when the observer is within three stack heights
distance from the stack.
Direction from observer—Specify the direction of the
emission point from the observer. This parameter should be
Notes
Documentation • 8-7
-------
Notes specified using one of the eight points of the compass (e.g.,
S, SE, NW, NE). A compass or map can be used to make this
determination. If a plotting table is used with a high-quality
compass, this determination is accurate to within 2°.
Figure 8-1. Slant-Angle Determination
Vertical angle to plume—Indicate the angle between the
horizontal plane (ground) and the line from the observer to
the point where the emissions were read.
Horizontal angle to plume—Indicate the angle between the
observer north line and the horizontal line from the observer
to the emission point.
Emissions Description
This section of the form includes information that definitely
establishes what was observed while the visible emissions
determination was being made.
Note: Information needed to complete this section might
change many times during the observation period. These
changes should be noted in the comment space beside the
appropriate opacity readings. These comments should be
referenced in the corresponding space in this section.
Describe emissions—Include descriptions of the physical
characteristics and behavior of the plume (not addressed
elsewhere on the form). Also, the observer should include
the maximum distance at which the plume is visible.
Physical descriptions could include such things as texture,
8-8 • Course 325. Visible Emission Evaluation Procedures
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gradation, and contents. Examples of descriptions include
"lacy," "fluffy," "copious," "mushrooming," "spreading
over horizon," and "detached non-water vapor
condensables." Standard plume terminology also can be
used to characterize plume behavior. This behavior is
generally used to determine the atmospheric stability on the
day of the opacity observations.
Emission color—Note the emission color. The plume color
can sometimes be useful in determining the composition of
the emissions. Plume color also serves to document the
color contrast between the plume and its background as seen
by the opacity observer. If emissions (such as those from a
basic oxygen furnace) change color during the observation
period, the color changes should be noted in the comments
space next to the opacity readings themselves.
If water droplet plume—This box is completed only if
visible water droplets are present. Check "attached" if
condensation of the moisture contained in the plume occurs
within the stack. In this case the water droplet plume is
visible at the stack exit. Check "detached" if condensation
occurs some distance downwind from the stack exit. In this
case the water droplet plume and the stack appear to be
unconnected.
Plumes containing condensed water vapor ("water droplet
plumes" or "steam plumes") are usually white and billowy,
and they are wispy at the point of dissipation. At this point
the opacity decreases rapidly from a high value (usually
100 percent) to zero if there is no residual opacity caused by
contaminants in the plume.
To document the presence or absence of condensed water
vapor in the plume, the following points must be addressed:
• Is sufficient moisture present (condensed or
uncondensed) in the effluent to produce water droplets
at in-stack or ambient conditions?
• If enough moisture is present, are the in-stack and
ambient conditions such that water vapor will condense
or form droplets before or after exiting the stack?
Notes
Documentation • 8-9
-------
Notes The first question can be answered by examining the
process type and/or the treatment of the effluent gas
after the process.
Some common sources of moisture in the plume are:
• Combustion
• Process loss
• Drying operations
• Chemical processes
• Control equipment (wet scrubbers)
If water is present in the plume, a prediction can be made
about whether steam plume formation is probable. Data
from a sling psychrometer in combination with the moisture
content and temperature of the effluent gas can be used to
make this prediction. These procedures were described in
Lesson 7.
Point in the plume at which opacity was determined—
Describe as accurately as possible the physical location in
the plume where the observations were made (such as the
distance from the emission point). This information is
necessary to establish that nothing interfered with the
observer's clear view of the contaminantplume. An example
of this type of interference would be condensed water
vapor. Knowing the point in the plume where the
observations were made is also important in the case of
secondary plume formation. Therefore, the observer must
specify:
• If the readings were made before water droplet plume
formation or after water droplet plume dissipation.
• The distance from the emissions point and/or water
droplet plume. Descriptions such as "4 feet above
outlet," "80 feet downstream from outlet," or "10 feet
after steam dissipation" are appropriate.
Observation Conditions
This section of the form covers the background and ambient
weather conditions during the observation period. These
factors could affect observed opacity.
8-70 • Course 325. Visible Emission Evaluation Procedures
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Describe plume background—Describe the background
against which the opacity is being read. Include
characteristics such as texture in the background description.
Examples of background descriptions are "structure behind
roofmonitor," "stand of pine trees," "edge of jagged, stony
hillside," "clear blue sky," "stack scaffolding," or "building
obscured by haze."
Background color—Describe the background color,
includingthe shade (e.g., new leaf green, conifer green, dark
brick red, sky blue, light gray stone). The observer should
try to choose a background that contrasts with the color of
the plume.
Sky conditions—Indicate the percent cloud cover of the sky
by using straight percentages (e.g., 10-percent overcast,
100-percent overcast) or by description (e.g., partly cloudy,
mostly cloudy, clear).
Wind speed—Record the wind speed. Speed should be
measured or estimated to ±5 miles per hour. The wind speed
can be measured with a hand-held anemometer or wind
speed can be estimated by using the Beaufort Scale of Wind
Speed Equivalents. (See Table 4.1.)
Wind direction—Indicate the direction from which the
wind is blowing. The direction should be estimated according
to one of the eight direction points of the compass. Wind
direction can be determined by observing which way the
plume is blowing. If the wind direction is not readily
discernible from the plume path, it can be determined by
observing a blowing flag or by noting the direction in which
a few blades of grass or a handful of dust is blown when
tossed into the air. The observer should keep in mind that the
wind direction at the observation point can be di fferent from
that at the emission point; the wind direction at the emission
point is the one of interest.
Ambient temperature—Measure the outdoor temperature at
the plant site with a thermometer and note which temperature
scale is used (Fahrenheit or Celsius). The ambient
temperature is used in conjunction with the wet-bulb
temperature when there are indications of a condensing
water droplet plume.
Notes
Documentation '8-11
-------
Notes Wet-bulb temperature—Record the wet-bulb temperature
from the sling psychrometer. This measure should be taken
when there is the possibility of a condensing water droplet
plume.
Relative humidity—Enter the relative humidity, which can
be determined by using a sling psychrometer and a
psychrometric chart. This information is used to determine
whether water vapor in the plume will condense to form a
steam plume.
Observer's Position And Source
Layout
Use this section of the form to identify the observer's position
in relation to the emission point, plant landmarks, topographic
features, sun position, and wind direction. Method 9 currently
requires a sketch that shows the relationship of the sun, the
observer, and the source.
Source layout sketch—This sketch should be drawn as a
rough plan view and should include as many landmarks as
possible. The exact landmarks included on the sketch
depend on the specific source, but they might include
buildings, roads, ponds, and other permanent landmarks. At
the very least, the sketch should show the relative positions
of the observed outlet and associated buildings so that these
landmarks will not be confused with others later. The sketch
also should clearly indicate the position of the observer
during the VE readings.
Include a sketch of the plume (indicating the direction of
wind travel). This will assist in subsequent analysis of the
reading conditions. The wind direction also must be indicated
in the observation conditions section of the form that was
discussed earlier.
Draw north arrow—To determine the direction of north,
point the line of sight in the source layout sketch in the
direction of the actual emission point. Place the compass
next to the circle and draw an arrow in the circle parallel to
the compass needle (which points north). Alternatively, a
map can be used to determine the direction of north.
8-72 • Course 325. Visible Emission Evaluation Procedures
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Sun's location—Verify the location of the sun before making
any opacity readings. The sun's location should be within
the 140° sector indicated in the layout sketch. This confirms
that the sun is within the 140° sector to the observer's back.
To draw the sun's location, the observer should perform the
following steps:
1. Point the line of sight in the source layout sketch in the
direction of the actual emissions point.
2. Move a pen upright along the "sun location line" until
the shadow of the pen falls across the observer's position.
3. Draw the sun at the point where the pen touches the "sun
location line" and the pen's shadow remains across the
observer's position.
Additional Information
This section of the form can be used to provide information on
actual conditions and/or deviations. The information should
pertain only to conditions that have a bearing on the opacity
observations and that have not been addressed elsewhere on
the form.
Additional information—Note actual conditions or
deviations that cannot be addressed elsewhere on the form,
such as in the comments section of the data set. These notes
must be factual and specific to the particular source. Examples
of information that can be included in this section are:
• Entry difficulties
• Interferences
• Presence of haze
Data Set
This section of the form is used for the opacity readings
obtained during the observation period. The readings should
Notes
Documentation • 8-13
-------
Notes be organized by minute and second. This section also includes
the actual observation date as well as start and end times for
the observation period. There is space next to each minute of
readings to note relevant comments.
Observation date—Here the observer should enter the date
on which the opacity observations were made.
Start time and end time—Here the observer should indicate
the times at the beginning and at the end of the actual
observation period. The times can be expressed in 12-hour
or 24-hour time (i.e., 8:35 a.m. or 0835), but 24-hour time
tends to be less confusing and is strongly recommended.
Time zone indication is also critical (e.g., EST, CST, EDT,
PDT, or MST).
Data set—Spaces are provided on one form for entering an
opacity reading every 15 seconds for up to a 30-minute
observation period. If observations continue beyond
30 minutes, a second form (and a third, etc.) should be used
to record additional readings. The readings should indicate
percent opacity and should be made to the nearest 5 percent.
The readings are entered from left to right for each numbered
minute.
The minutes run from top to bottom. The first entry would
be entered in the top left-hand box (MIN1, SEC 0). The next
entry would be entered in the top row second box from the
left (MIN 1, SEC 15). The next readings are entered
consecutively in the spaces labeled MIN 1,SEC 30; MIN 1,
SEC 45; MIN 2, SEC 0; MIN 2, SEC 15; etc.
If for any reason a reading is not made for a particular 15-
second period, a dash (-) should be placed in the space. A
blank space might be taken for an oversight. The comment
section beside that reading should be used to explain why
the reading was missed.
Comments—Spaces for comments are provided next to the
data for each minute of opacity readings. These spaces can
be used to note changing observation conditions and/or
reasons for missing readings. Items to be noted include
wind shift, changing background, and interfering emissions.
8-74 • Course 325. Visible Emission Evaluation Procedures
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Observer Data
Notes
This section of the form deals with the information required to
validate the opacity data.
Observer's name—Print entire name.
Observer's signature—Self-explanatory.
Date—Enter the date on which the form was signed.
Organization—Enter the name of the agency or company
employing the observer.
Certified by—Identify the agency, company, or organization
that conducted the "smoke school" or VE training and
certification course where the observer' s current certification
was obtained.
Date—Provide the date of the current certification.
Forms Interrelation
This section should be used if the observer has continued VE
observations on additional forms that are related to the same
observation.
Continued on VEOform number—Here the observer should
fill in the five-digit number of the Observation Form, if any,
where the observations from the form in use are continued.
Each form of a series that is followed by another form will
have the number of the next form noted in this section.
Documentation • 8-15
-------
Review Questions
1. Violation of visible emissions standards from either an NSPS or a SIP can
result in a fine of up to .
2. Which of the following would be the best way to indicate the time of
observation?
a. 1:45
b. 1345
c. 1:45 EDT
d. 1345 EDT
3. Where should an observer record events that affect the validity of the
observation (such as interfering plumes)?
4. Where would the following entry be on the VEO form?
"85-percent production rate"
5. Where would the following entry be on the VEO form?
"Tallest of four stacks, directly south of a small pond"
6. What would an observer enter in "Direction From Observer" for the
following?
7. To document the presence or absence of condensed water vapor in the
plume, what two points must be addressed?
8. Where would the following be found on the VEO form?
"Stand of pine trees"
8-76 • Course 325. Visible Emission Evaluation Procedures
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Review Questions (cont.)
9. Which of the following would be appropriate for the "Source layout sketch"?
(You may select more than one.)
a. Buildings
b. Other emission outlets
c. A crane
d. A pond
e. A delivery truck
10. The sun must be within a degree sector to the observer's back.
11. If a reading is missed, how should an observer indicate this?
12. If all the observations will not fit on one form, where should additional
information be recorded?
Documentation • 8-17
-------
Lesson 9
Equipment
-------
Equipment
Introduction
Method 9 does not require unique equipment or supplies—
just a few general items. This section provides specification
criteria or design features to help select equipment that will be
useful in collecting VE data. These specifications are based
on observer experience observing plumes and plume
conditions.
Supplies
The observer should have a clipboard, several black ballpoint
pens (medium point), several large rubber bands, and a
sufficient number of VE observation (VEO) forms. The
clipboard should be dark, with a black plastic or other
nonreflective paper clip that will not reflect the glare of the sun
while the observer is making observations on bright days.
One or two rubber bands around the bottom of the clipboard
are useful for holding down forms.
The observer should use high-quality reproductions of the VE
forms because they will probably be reproduced numerous
times during the litigation process. Using a high-quality,
black, medium ballpoint pen to fill out the forms will enhance
the quality of subsequent copies. If there is a chance that the
forms will get wet during the observations, the observer
should reproduce the forms on plastic paper available from
office supply stores. It is also useful to copy the forms onto
light-blue or green paper if glare is a problem.
Equipment
Timer/Watch
The observer should use a watch to time the 15-second
intervals between opacity readings. Liquid-crystal-display
watches are good because they are easy to read. The observer
Notes
Equipment • 9-3
-------
Notes
can even mount two stick-on timers on the clipboard, one set
to alternate between time and date and the other to count
seconds. These timers are available with displays Vi inch or
larger. A watch with a beeper that sounds every 15 seconds
allows the observer to focus on the surroundings, which is
especially important in busy industrial areas.
Compass
The observer uses a compass to determine the direction of the
emissions point from where the observer stands and to
determine the wind direction at the source. For accurate
readings, the compass should have a resolution better than 5°.
The compass should be jewel-mounted and liquid-filled to
dampen the needle swing. Map-reading compasses are excellent
for this purpose and come in two types:
• Card
• Needle
iiiiiBiiiianiiBiiiiBiiii
Figure 9-1. Card-Type and Needle-Type Compasses
The card-type compass has a circular disk, marked in degrees,
that rotates on a pivot. The needle-type compass has a needle
with a north marker that indicates magnetic north. The
observer should keep the compass level and away from ferrous
metals. Even a small amount of ferrous metal, such as the clip
on a clipboard, can influence the reading on a compass. This
makes the hood of a car an unsuitable place to take a compass
reading. It is also important to know the magnetic declination
from true north at the observation location. Sizeable
documentation errors can be generated when an observer
relies on a compass alone for determining direction. For this
reason, a map should be used in conjunction with a compass
to ensure accuracy.
9-4 • Course 325, Visible Emission Evaluation Procedures
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Maps, Plans, And Aerial Photographs
The best maps to use for opacity work are U.S. Geological
Survey maps. Quadrangle maps are available in a large
enough scale to allow individual buildings to be identified.
These maps give the magnetic declination as well as the
relative heights of the topography. Company plans are not
useful if they do not reflect the final construction configuration.
Current aerial photographs are extremely useful and are
usually available from a map service or an aerial photographer
at a nominal cost. The stack height can be calculated from
these aerial photographs by using the length of the shadow
from the stack and the time of day and time of year that the
photograph was taken.
Rangefinder
A rangefinder measures the observer's distance from the
emissions point and should be capable of determining distances
to 1,000 meters with an accuracy of ±10 percent. The accuracy
of the rangefinder should be checked on receipt and periodically
thereafter with targets at known distances of approximately
100 meters and 1,000 meters. The two common types of
rangefinders are stadiometric and split image. For ease of use
and portability, most observers prefer the stadiometric
rangefinder, but either type is acceptable.
Clinometric Devices
Clinometric devices determine the vertical viewing angle. For
VE observation purposes, a clinometric device should measure
within 5°. Clinometric devices include:
• Abney level
• Clinometer
• Sextant
The Abney level was designed for forestry work and is the
most practical clinometric device for determining opacity
because of its portability and field ruggedness. An Abney
level costs about $ 100. Clinometers can be somewhat cheaper,
but they are not as well suited for opacity work. The sextant
is the most accurate of the clinometric devices. It can
determine the vertical angle within minutes of an arc. The
Notes
Equipment • 9-5
-------
Notes sextant is harder to use, and it is not as durable as either the
Abney level or the clinometer unless an expensive model is
purchased. Sextants are not as compact as either of the other
devices.
Figure 9-2. An Abney Level—A Type Of Clinometric Device
Drawing Tools
An invaluable accessory is a template that has basic shapes cut
out to help draw the sketch required by Method 9. One of the
best templates is a small computer-programming template
available at office supply stores.
Anemometers
Anemometers are devices that determine wind speed. The
three basic types are:
• Mechanical
• Electronic
• Pressure
Mechanical anemometers measure the wind with a rotating
turbine. The rate of rotation depends on the wind speed. The
rate of rotation is electrically determined and translated into
wind speed on a meter or display.
Electronic anemometers usually consist of a hot wire that is
cooled by the air flowing past. The faster the air flow, the more
cooling occurs. The amount of current required to reheat the
wire is then translated to wind speed. These electric (or hot-
wire) anemometers are the most expensive of the wind-speed
instruments.
9-6 • Course 325, Visible Emission Evaluation Procedures
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Notes
The simplest anemometer and the most popular among
field personnel is the pressure type. It consists of either
a hinged pressure plate that rises with wind speed or a
variable orifice flow meter (rotameter) with an indicator
that rises proportionally to wind speed.
Sling Psychrometer
A sling psychrometer is used when the atmospheric
conditions might promote steam plume formation. The
psychrometer consists of two thermometers, accurate to
0.5°C, mounted on a sturdy assembly that allows the
thermometers to be swung rapidly in the air. One
thermometer is fitted with a wettable cotton wick tube on
the bulb. If for some reason the wick is missing, a cotton
shoelace can be substituted. Thermometer accuracy
should be checked by placing the bulbs in a fresh-water/
ice-water bath and checking to see that they read 0°C.
A person uses a sling psychrometer by wetting the cotton
wick and swinging the assembly through the air until the
temperatures of both thermometers stabilize. Because of
evaporative cooling, the wet-bulb temperature will be
lower than the dry-bulb temperature if the relative
humidity is below 100 percent. The difference between
the two temperatures indicates relative humidity. The
relative humidity can be calculated from these two
values by using either a psychrometric chart or a slide
rule that has the necessary scales.
Figure 9-3. Sling Psychrometer
Equipment • 9-7
-------
Notes Binoculars
Binoculars are helpful for identifying stacks, searching the
area for emissions, and helping to characterize the behavior
and composition of the plume. Method 9 neither prohibits nor
endorses the use of binoculars for opacity observations, but if
binoculars are used they should have a magnification of at
least 10 x 50; color-corrected, coated lenses; and a rectilinear
field of view. Color correction can be checked by viewing a
black and white pattern, such as a Ringelmann card, at a
distance greater than 50 feet. No color rings or bands should
be evident; the observer should see only black and white. The
rectilinear field of view can be tested by viewing a brick wall
at a distance greater than 50 feet. There should be no distortion
of the brick pattern as the field of view is changed.
Camera And Accessories
A camera should be used to document the emissions before,
during, and after the actual opacity determination. A 3 5-mm
camera with through-the-lens light metering is recommended.
Useful accessories include a macro lens, or a 250- to 350-mm
telephoto lens, anda 6-diopter close-up lens (forphotographing
the logbook and evidence of particulate matter deposition). A
photo logbook is necessary for proper documentation, and the
observer should use fresh, color- negative film (ASA 100 is
recommended). It is important to save the last two or three
exposures on each roll to photograph the logbook.
Video
Most video equipment on the market is unsuitable for
documenting opacity because of the poor resolution and
tonal registration of the recording system. When a duplicate
is made, the situation is even worse. Avoid VHS and regular
8mm, and if a plume must be videotaped, use one of the
following formats:
• 3/4 inch or greater
• Super VHS
• High-resolution 8-mm
One advantage of video is the automatic date and time
function in most modem cameras that can support the testimony
9-8 • Course 325, Visible Emission Evaluation Procedures
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concerning changes in opacity. Another advantage of using Notes
video is the ability to document intermittent plumes from
cyclic processes.
Computers And Software
Several MS DOS programs are useful, althoughnot necessary,
for an observer preparing reports on VE observations.
Particularly helpful software includes:
• Spreadsheets
• U.S. Naval Observatory Industrial Combustion
Emissions (ICE) Model
• Instack
• Opacicalc
Spreadsheets can be used for data analysis, graphing, and
statistical calculations. The ICE program is used to determine
the actual position of the sun at the time of the observation.
Instack can be used to calculate mass/opacity relationships.
Opacicalc is a commercial program that calculates:
• Rolling averages
• Time aggregation
• Slant-angle effects
Duct-size differences
Equipment • 9-9
-------
Review Questions
1. Why should an observer use high-quality reproductions of the VEO form?
2. What kind of maps are the best for opacity work?
3. What does a rangefinder do?
4. What does a clinometric device do?
5. What does an anemometer do?
6. How are the two thermometers on a sling psychrometer different?
What do their two temperatures indicate?
7. If an observer is going to use binoculars, what two qualities should he or she
look for in the binoculars?
8. Why is most of the video equipment on the market today unsuitable for
opacity documentation?
9-10 • Course 325, Visible Emission Evaluation Procedures
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Lesson 10
Field Training
And Certification
-------
Field Training
And Certification
The field training and certification program is presented after Notes
the completion of the VE enforcement procedures classroom
session. The field training and certification program is held
outdoors using a smoke generator to present black or white
smoke plumes and a measuring device that determines opaci-
ties from 0 to 100 percent.
Because this session is conducted outdoors, it is important to
wear appropriate clothing. The student should bring the fol-
lowing items to the field session:
• Two medium, black ballpoint pens
• Clipboard
• Two rubber bands
Optional items include:
• A folding chair
• Beverage or snack
• Golf umbrella
• Sunscreen
• Hat
The field certification process has five elements:
• Demonstration of standards
• Practice plumes
• Testing for black and white
• Grading
• Retesting, if necessary
Standards And Practice Plumes
First, the generator operator demonstrates the standard plume
values of 25, 50, and 75 percent. This demonstration helps ori-
ent the observer to the scale used in the testing program. Next,
each observer is issued a practice form. This form is used be-
Field Training and Certification • 10-3
-------
Notes fore actual certification runs. Four practice plumes are generat-
ed, and the trainees estimate the opacity of each plume, basing
the estimate on the given standards. The opacity estimate
should be expressed in 5-percent increments. The trainer then
calls out the correct answers to the four practice plumes. The
trainees write down the correct answers beside the estimates
and compare the answers. Only after a significant number of
trainees are ready will actual certification testing begin.
Testing Requirements
To receive certification as a qualified observer, a candidate
must demonstrate the ability to assign opacity readings in 5-
percent increments to 25 different black plumes and 25 differ-
ent white plumes, with an error not to exceed 15-percent
opacity on any one reading and an average error not to exceed
7.5-percent opacity in each category (black and white).
Testing Form
After the practice session, a two-part form is handed out. An
example of this form is given at the end of this lesson. Train-
ees fill in this form as follows:
1. Last name, first name, middle initial
2. Affiliation (employer)
3. Run number (announced by trainer)
4. Course location (city)
5. Date
6. Trainees indicate whether or not they are wearing sun-
glasses and, if so, the type (Polaroid, Photogray, etc.)
7. Description of cloud conditions under the "sky" heading
8. Wind speed and direction (announced by trainer)
9. Estimated distance to the stack
10-4 • Course 325, Visible Emission Evaluation Procedures
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10. The affirmation is signed when the form is handed in. Notes
11. The trainer announces whether the smoke will be black or
white, and the appropriate circle must be marked on the
form.
When all these steps have been completed, trainees are ready to
take the test. The test consists of a set of 25 black plumes and a
set of 25 white plumes. The plumes are generated at random
levels of opacity within each test set. The standards are shown
again before the test.
Field Testing For Black And White Plumes
Trainers will announce when the plumes should be read and
when the papers should be marked. The following procedure is
used during the test:
Note: The following presentation of proper field test proto-
col is given in the second person voice for clarity; the state-
ments are addressed to you as trainee.
Before reading the plume, do not observe the stack but,
instead, look at the ground or at your paper. The generator
operator will announce:
"Reading Number 1"
Look up and make your determination of the opacity. Ap-
proximately 1 to 3 seconds will be allowed. The generator
operator will then announce:
"Mark"
At the word "mark," immediately look away from the
plume and mark your paper. Simply circle the answer that
best matches the observation. Do not look back at the plume
until the next reading number is announced.
This process continues for the entire first set. Check your paper
for missing observations or for observations made on the
wrong line. If you need to change an answer, cross out the one
to change and circle the new answer.
Field Training and Certification • 10-5
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Notes If the wind makes the plume unreadable by blowing it towards
or away from you, yell "scratch" loud enough for the generator
operator to hear. The operator will then repeat that reading,
because the goal is to give the best possible test plumes.
If the generator operator interrupts the reading with the word
"scratch," do not mark the paper. The plume will be repeated
at the same opacity value.
The process will then be repeated for the set of plumes of the
other color.
Grading
At the conclusion of the test, the white copies of the certifica-
tion test form will be collected. After they are all collected, the
actual values from the run will be announced. Mark the yellow
copy with a slash on each value that the operator announces.
After all 50 values are announced, compare your answers to the
correct answers. For each value, count the number of spaces (if
any) between the two answers. Remember, it does not matter
whether your value is higher or lower than the correct an-
swer—just count the number of spaces.
For example, if 20 had been circled and the operator an-
nounced, 25, the error would be one space:
@ 26 30 35 40
20 circled and 30 announced would be an error of two.
@ 25 30 35 40
20 circled and 35 announced would be an error of three.
@ 25 30 36 40
20 circled and 40 announced would be an error of four.
@ 25 30 35 40
Record the errors on the right-hand side of the paper. When
you finish marking errors, you can determine whether you
passed. The two criteria are:
• No error of 4 or greater anywhere on the page
• Total error of less than 38 on each of the sets
70-6 • Course 325, Visible Emission Evaluation Procedures
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The white plumes and black plumes can each have a total error Notes
of up to 37.
If your paper meets both of the criteria stated above, the yellow
sheet should be passed to the graders, who will then grade the
original for record.
If you are sure that there are no grading errors, and if you have
passed, you have completed the certification process. A certifi-
cate will be sent to the address on the registration form within
two weeks.
Retesting
If an error of 4 or greater appears anywhere on the page, or if
the total error on either of the sets is more than 37, retesting is
necessary.
Common Errors
The most common error in making smoke observations is star-
ing at the plume. As demonstrated in earlier lessons, it takes
less than 20 seconds of staring to bias your vision and make
accurate observations nearly impossible. The second most com-
mon error made during certification is reading the plume at the
wrong time. To prevent these problems, trainees must listen
carefully to the generator operator and follow instructions.
Certification Period
The certification is valid for 6 months, at which time the quali-
fication procedure must be repeated to retain certification.
Field Training and Certification • 10-7
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Review Questions
1. What items should the student definitely bring to the field session?
2. Will practice plumes be shown before the test? If so, what percentages will
they be?
3. What should the observer do when the generator operator says, "Reading
Number 1"?
4. What should the observer do when the generator operator says, "Mark"?
5. If the plume becomes unreadable, what should the students yell?
6. If a student marked a 30 and the actual value was 50, this would be an error
of .
7. What are the two criteria for passing a test?
8. What is the most common error in making smoke observations?
9. How long is the certification valid?
10-8 • Course 325, Visible Emission Evaluation Procedures
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Lesson 11
Presentation Of Opacity
Data In Court Cases
-------
Presentation Of Opacity
Data In Court Cases
Types Of Evidence Notes
Types of evidence that the visible emissions (VE) observer
might be required to present include:
• Visible Emissions Observation (VEO) forms
• Certification records
• Notebooks, field logs, etc.
• Photographs and videotapes
The observer's testimony will serve to substantiate the evidence,
showing that it was collected, maintained, and analyzed correctly.
T^pes Of Witnesses
The following types of witnesses are generally recognized:
• Fact witness
• Trained witness
• Expert witness
Fact Witness
Fact witnesses have direct knowledge of a fact because they
have seen it, smelled it, heard it, tasted it, felt it, or done it.
They testify in court to the facts. Many observers can be used
as fact witnesses. They testify that they saw visible emissions
or other opacity evidence. This is the simplest witness situation,
because the only qualification is that the witness observed the
fact of emissions.
Presentation of Opacity Data in Court Cases • 11-3
-------
Notes Trained Witness
Generally, VE observers are introduced as trained witnesses.
The observer's training could become an issue. After the ob-
server's credentials are verified, he or she testifies to the mea-
surements made and the procedures followed. It is not necessary
for the trained witness to explain why the measurements were
made in a specified manner if clear procedures, such as those in
Method 9, are available. Such explanations are left to an expert
witness.
Expert Witness
An expert witness is anyone who has specialized knowledge of
issues and principles in an area pertinent to the case. An expert
witness can testify to facts in the case and will often be asked to
give an expert opinion as to their meaning. Because an expert
witness is expressing an opinion, the court must be satisfied
with his or her credentials. Establishing these credentials can be
difficult, and if the defense attorney can keep an expert witness
from being regarded as an authority, the prosecution's case will
be damaged. Once credibility is established, however, the ex-
pert witness is often asked to explain the regulations, proce-
dures, and documentation to the court. Expert witnesses are
often asked hypothetical ("What if... ?") questions.
Depositions
A witness will receive a notice of deposition, which is an order
to attend. In the deposition, the defense attorney probes to de-
termine what the witness will say on the stand. Defense attor-
neys take depositions for several reasons:
• They are looking for flaws in the prosecution's case.
• They want to see what kind of witnesses they are up
against.
• They want to see what the witness knows and/or does
not know.
11-4 • Course 325, Visible Emission Evaluation Procedures
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• They want to see whether the witness can defend his or Notes
her data and whether the witness has data of which he or
she is not aware.
• They want to intimidate the prosecuting team.
In the deposition, the observer will be represented by the prose-
cuting attorney, who will "defend the deposition" and protect
the witness' rights.
Documents
The deposition is often taken duces tecum, which means that
the witness is required to bring certain documents to the deposi-
tion. These documents will be listed in the notice of deposition.
The witness should consult with the prosecuting attorney be-
fore bringing any documents to the deposition.
Preparation For The Deposition
The witness should review the deposition process with the pros-
ecuting attorney before attending the actual deposition. This
briefing is not to set up testimony but to make sure that the
witness understands the "rules of the game" at the deposition.
A deposition is not as structured as a court case. Often the
attorneys use the deposition as a forum to iron out matters
between themselves and to test each other. It could be the first
time they meet face to face. The witness should ignore any
theatrics that occur between the attorneys.
Attendance
The following persons can attend the deposition:
• Attorney for the plaintiff, along with legal assistants and/
or additional attorneys.
• Attorney for the defendant, along with legal assistants
and/or additional attorneys.
• The court reporter.
Presentation of Opacity Data in Court Cases -11-5
-------
Notes • Experts for either side (to advise the attorneys and to
help prepare questions).
• The witness.
Procedure
At the beginning of the deposition, the witness is sworn in. The
deposition becomes a part of the court records, and the witness
is subject to the laws of perjury. Witnesses do not have to
swear to God; they can affirm.
The attorneys will make a few opening remarks and then turn
their attention to the witness. The following, which is a tran-
script from a deposition, is a typical series of questions:
Q: You understand that the format is that I will ask you
questions, you will be answering those questions, you
are sworn under oath, and the questions will be tran-
scribed by the court reporter?
If you have any questions regarding the questions that I
am posing to you or if it is not clear to you what I am
asking, then I would be glad to rephrase it.
Q: I would like to start with some background, educational
background. Could you describe for me your education
since high school?
These questions set the tone of the deposition and serve to relax
the witness. After these preliminaries involving the witness'
education and experience, the defense attorney will begin to
question the witness. How the questions are answered and how
much information is given are extremely important issues.
Rules By Which To Testify
For the first-time witness, it is important to know the following
rules for testimony:
• The witness should always tell the truth.
• The witness should listen carefully to the questions.
11-6 • Course 325, Visible Emission Evaluation Procedures
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• The witness should wait a few seconds after each ques- Notes
tion before answering. The purpose of the pause is:
• To give the witness' attorney time to object.
• To give the witness time to think about the question.
• To allow the witness to pace the questioning and keep
from getting flustered.
• The witness should speak clearly and slowly enough for
the court reporter to get an accurate record. The witness
should spell names and special terms for the reporter.
• The witness should answer any sensible question that is
not a compound question and should ask for clarifica-
tion if a question does not make sense. The witness
should not answer compound questions. Instead, the
witness should ask the attorney to rephrase the question
as two questions.
• The witness should not argue with the opposing attorney;
that is the job of the witness' attorney.
• If the witness' attorney objects to a question, the witness
should let things settle down between the attorneys be-
fore answering. Then the witness should ask that the
question (if it stands) be read by the court reporter be-
fore answering it.
• The witness should answer questions with the
shortestpossible answers. The witness should use a sim-
ple "yes" or "no" if possible. A witness who says, "Let
me explain that answer," is getting into trouble.
• The witness should ask to take a break if necessary; the
witness is not obligated to endure any physical discom-
fort.
Remember that the opposing attorney's job is to probe and find
flaws in the witness' case so that his or her client can be acquit-
ted. Almost any area is fair game.
Presentation of Opacity Data in Court Cases • 11-7
-------
Notes During the deposition, the witness might be asked to review
documents or create drawings or other exhibits, and sign them.
If in doubt as to what to do, the witness should seek the advice
of the prosecuting attorney, who is there to assist the witness.
At some time after the deposition, the witness should receive a
printed copy of the text of the deposition. The witness needs to
check the text carefully to see that the court reporter transcribed
the testimony correctly. The witness should also fill out the
revision sheet and return it promptly.
Affidavits
In the filing or counter-filing of a case, the witness might be
required to prepare an affidavit. An affidavit is a court docu-
ment, signed under penalty of perjury, that describes the wit-
ness' background and the assertions that he or she will make in
court. The witness should follow these steps when preparing an
affidavit:
1. Discuss the specific requirements of the judicial juris-
diction in which the affidavit is being filed with the
prosecuting attorney. In addition, they should discuss
the specific items that the attorney wants covered.
2. Prepare a draft copy of the affidavit for the attorney.
3. Revise the document according to the attorney's needs.
4. Finally, sign, notarize (often not required), and date the
final affidavit.
Testimony
In a visible emissions enforcement case, the observer will usu-
ally testify about the opacity levels observed at a facility during
an inspection or surveillance activity. This testimony will be
used to substantiate evidence in the VEO form. The observer
will not be asked to remember the actual values observed,
because they are on the form. The observer is often asked
about methods and procedures used and whether this informa-
tion is included on the form.
11-8 • Course 325, Visible Emission Evaluation Procedures
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When the observer is on the witness stand, the same rules apply Notes
as those that applied during the deposition. There are three
additional guidelines to keep in mind:
• The witness should "dress the part." Usually, a conserva-
tive suit is best; people (i.e., the judge and jury mem-
bers) are confused when a person does not dress
appropriately.
• The observer should smile naturally at the judge and jury
when taking the stand. He or she should relax; a relaxed
witness is more credible than one who is nervous.
• The observer should not become angry with the opposing
attorney; that is the job of the observer's attorney. This rule
is far more important during the trial than in the deposition.
The observer should remember that the defense attorney is
evaluating evidence based on his or her perceived trust-
worthiness of and personal feelings toward the witness.
Finally, it is most important that the observer should always tell
the truth.
Presentation of Opacity Data in Court Cases • 11-9
-------
I
I Review Questions
1. List four types of evidence an observer might be required to present in court.
2. What is the difference between a fact witness and a trained witness?
3. What does the opposing attorney try to find out in a deposition?
4. List five people who might attend a deposition.
5. List three or more of the rules by which to testify.
6. A court document signed under penalty of perjury that describes the witness'
background and what the witness intends to say in court is an
7. Will an observer be asked to remember actual observed values? Will an
observer be asked about methods and procedures used?
11-10 • Course 325, Visible Emission Evaluation Procedures
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Lesson 12
Quality Assurance
And Auditing
-------
Quality Assurance
And Auditing
As a part of the preparation for litigation, the observer should Notes
audit the data that he or she plans to introduce and defend in
court. The following two sections are designed to assist the
observer or supervisor in auditing the VEO form and the certi-
fying VE training program. If a VEO form is worth $25,000 in
a civil fine, it is assured that a defense attorney is going to
examine the form closely.
Auditing The VEO Form
The following discussion presents a systematic process for au-
diting the VEO form. This process uses a standard audit form,
which is found at the end of this chapter on pages 12 - 12a, b,
and c. Before the audit is initiated, the information on the VEO
form that concerns the source and observer should be copied
onto the audit form to help keep the records straight.
Certification date?
Check the section on the VEO form for the certification date.
Compare this date to the observation date. The certification is
valid for a period of six months. Therefore, if the certification
date predates the observation date by more than 6 months, the
observations are invalid.
Checking for Horizontal Sun Angle
Three areas on the VEO form can be used to indicate horizontal
sun angle:
• The source layout sketch. Is the sun location marked
on the sun location line?
• The section that deals with the direction from the ob-
server to source section.
• The block showing the observation date and observa-
tion period start/stop times.
Quality Assurance and Auditing • 12-3
-------
Notes A means of information corroboration is built into these three
sections if the north directional arrow is given correctly in the
source layout sketch. Look at the north arrow's relationship to
the source and determine whether there are any discrepancies
when compared to emission point "Direction from Observer"
line on the VEO form. If the observer was contradictory about
direction of source, he or she was probably mistaken about sun
location, also.
After using the sketch to determine if the horizontal sun angle
is correct, the relationship of the reported direction from the
observer and the source and the time of day must be considered
to see if it is reasonable. For example, if the time of the
observation is noon and the observer's sketch shows the sun
over the left shoulder, the observer must be southeast of the
source. Sketching the relative positions on polar graph paper is
a useful technique to establish that the observations were per-
formed and documented correctly.
Checking for Vertical Sun Angle
The vertical sun angle problem is similar to the horizonal sun
angle problem. The line from the height of the sun in the sky
to the observer and the line from the observer up to the emis-
sion point should be 110 degrees. To audit for vertical sun
angle, it is necessary to note the time of day, year, and location
of the facility in terms of latitude and longitude. Given this
information, solar tables or the US Naval Observatory ICE
program may be utilized to get the sun location.
Using the ICE Program for Verification
The US Naval Observatory ICE program can confirm the hori-
zontal and vertical sun angles. This program will quickly cal-
culate both sun angles at any location and time on a MS-DOS
computer with a minimum memory of 512K.
The sun observation source (SOS) angle is created by the inter-
section of the sun observation line and the source observation
line. If either vertical or horizontal angles are nearly out of
compliance, the SOS angle may be out of compliance. If the
SOS angle is less than 110 degrees, the observer will not meet
Method 9 criteria for sun angle. The 140 degree sector de-
scribed in Method 9 is more than a horizontal measurement of
72-4 • Course 325, Visible Emission Evaluation Procedures
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the sun rotating about a horizontal plain from an eastern point Notes
(south of center if located in the northern hemisphere) through
to a western point. The angle also has a vertical element in that
the sun moves vertically towards an apex during the day. There-
fore, both vertical and horizontal sun angles need to be ad-
dressed to determine if Method 9 criteria have been met.
3. Background viewed along narrow axis of vent? If not,
what is the effect: This question refers to a rectangular vent.
Plume opacity from such a vent should be read through the
narrow axis. The observer should be standing approximately
perpendicular to the longer axis of the vent. The rectangular
stack should be noted on the VEO form under "describe emis-
sion point" and on the sketch.
4. Background viewed along narrow axis of plume? Is it
acceptable? The plume should run approximately perpendicu-
lar to the observer's line of sight. Information pertaining to this
subject can be found in sections of the VEO form that contain
information on the source layout, height relative to observer,
distance to stack, and point in the plume at which opacity was
determined. If the source layout sketch indicated that the plume
was observed at a point where it was traveling perpendicular
(or nearly so) to the observer's line of sight, the viewing angle
is acceptable.
During plume rise? If the sketch indicates that the plume is
not traveling perpendicular to the observer's line of sight and if
the plume was evaluated during plume rise before the plume
travelled horizontally, there needs to be a description or addi-
tional supporting sketch documenting that plume travel is not a
factor.
Slant angle? If the observation was made at a location where
the plume appeared as a vertical column, slant-angle effects
should be considered. As described in Lesson 7, the slant angle
is based on the distance from the observer to the stack and the
height relative to the observer of the point in the plume at
which opacity was observed. If the observation angle deviates
from looking perpendicular through the plume column by more
than 18° degrees, corrections for slant angle are needed.
Slant-angle effect? If slant-angle problems are indicated, the
auditor should determine whether those effects have been re-
ported and whether appropriate corrections have been made.
Quality Assurance and Auditing • 12-5
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Notes 5. Plume evaluated against contrasting background? If the
plume is reported as a dark color, the background of greatest
contrast is blue sky, white clouds, or white structures. If the
plume is reported as a light color, the background should be a
dark color and have a great deal of structural texture.
6. Plume continuous? A plume is continuous if the duration
of emissions is greater than 6 minutes. A plume is 'intermit-
tent' if the opacity cycle is less than 6 minutes.
7. Six-minute average complete? ( consecutive values).
Twenty-four consecutive 15-second readings are needed to per-
form the 6-minute average required by Method 9. Count the
opacity readings and make sure that there are 24 consecutive
readings between the start and end and that gaps are separated
by 24 consecutive readings. Short gaps within the data block
may be acceptable if explained on the data forms.
8. Positive observational error taken into account? Obser-
vations are 5%, 7.5%, 10% above the standard. This informa-
tion will go to the weight of the evidence. If a summary
judgement is being sought, observations of 7.5 percent or 10
percent above the standard are preferred. Lower margins can
be used in actual court cases.
9. Sunglasses used? Type? Used during certification? If
sunglasses are worn during a VE observation, a note should be
made of it on the VEO form. The observer should be certified
with the same glasses, and the certification form should so
indicate.
The sunglasses should have gray or green lenses, because other
colors will change the response curve of the observer's vision
and affect the view of small particles in the plume.
The type of sunglasses frequently will be indicated on the certi-
fication form but will not be identified on the VEO form. Pho-
to-gray lenses should be avoided, especially on partly cloudy
days. As the sun appears from behind a cloud, a plume may
lose its visibility because the lenses darken.
10. Data gaps explained? If a data gap occurs, that gap
should be explained fully in the "comments" section. A data
gap should be indicated with a "G" or a "-" to document that it
is not just an oversight.
72-6 • Course 325, Visible Emission Evaluation Procedures
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11. Source dimensions - roadway length, etc.? Is the infor- Notes
mation on plant dimensions and source location sufficient to
define clearly the point at which the emissions originate?
12. Distance of observer from emissions source? If the
distance from observer is not known exactly but is estimated
(or approximated), it should be prefixed with a tilde mark (~).
If an exact value is presented with no documentation of land-
marks or other known dimensions, the presentation may dam-
age the credibility of the observer if this information is later
proven to be slightly in error.
13. Height above source that readings were made? The
location of the plume reading is given in the section of the VEO
form that specifies "point in the plume at which opacity was
determined." The opacity should be read at approximately one
stack diameter above the stack exit, if possible. Dilution can
occur if the reading is taken too far from the stack exit; this
dilution will decrease apparent opacity and result in readings
that are biased low. In high wind situations, the plume may be
sheared off; consequently opacity is difficult to read. Check
"wind speed" and other factors to see whether shearing might
have been a problem. Another factor that affects the validity of
the location of the readings is the presence of water droplets in
the plume. The plume should be read at the point of greatest
opacity where water droplets are not present. Check "If water
droplet plume" section of the VEO form to ensure that the
plume was read after water droplets dissipated.
14. Wind speed available? Check the wind speed estimate
for reasonableness. Wind is rarely one speed, and a range
should be given (e.g., 4-7 mph). If wind speeds are very high
(greater than 20 mph), there is a strong likelihood that the
opacity values recorded have a negative bias introduced by
intense dilution of the plume.
Wind direction available? Check for contradictions between
the wind direction arrow presented in the sketch and the "wind
direction" section in the VEO form. Wind direction should
always be stated in terms of the direction from which the wind
is blowing. The auditor should document any contradictions.
Quality Assurance and Auditing • 12-7
-------
Notes 15. Collaborative readings taken? Did anyone else perform
a VE observation at the same time as the observer in question?
Other data could serve to substantiate or repudiate the data in
the VEO form or record. If other data were taken, the auditor
should examine those data for consistency with the data that are
being used to establish the case.
16. Description of sky conditions provided? A description
of sky conditions is a helpful indication that the observer was
aware of surrounding weather conditions. This description also
provides information on the amount and type of lighting avail-
able (i.e., constant lighting, fluctuating lighting, bright lighting,
low lighting). Terms such as overcast, broken, partly cloudy,
scattered, clear, rainy, or foggy should be found in the section
of the VEO form marked "Sky Conditions."
17. Interferences present? Interferences can include other
plumes in the background and foreground. Fugitive emissions
also can create interferences. A piece of equipment that moves
through the observer's viewing field to block the view totally
also can interfere with VE readings. The apparent opacity
could increase or decrease. Interferences also include fog or
other meteorological activities.
Regardless of the interference, the opacity should not be read
during this time and the 15-second interval should be marked
with a data gap. The auditor should provide a brief written
summary of how the interferences affected the readings.
18. Steam plume present? - Confirmation visual? In the
"if water droplet plume" section on the VEO form, "attached"
or "detached" should be checked if a water droplet plume ex-
ists. If neither applies, the NA notation should be placed into
the section as an indicator that the issue was considered. A
steam plume is very white and billowy, and visible emissions
should be read after the steam dissipates or before the steam
forms. If emissions are described using these words in the
sections of the VEO form that describe emissions and emission
color, the observer may have been observing a water droplet
plume without realizing it. Also, the "point in the plume opaci-
ty was determined" section is important if steam plumes were
present. The auditor should review that section of the VEO
form in concert with the evaluation described here.
72-8 • Course 325, Visible Emission Evaluation Procedures
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Confirmation modeled? It is important that the VE observer Notes
understand the process and whether it provides a source of
moisture in the plume. The auditor should check "wet bulb"
and "dry bulb" temperatures to ensure that they were recorded.
These data can be used in conjunction with information on
stack gas moisture content and temperature, if known, to derive
a gas stream humidity temperature dilution line (GHTD line)
on a psychometric chart. This line can be evaluated as to its
position to the 100 percent relative humidity curve on the psy-
chometric chart to predict plume moisture condensation. Equa-
tions presented in Lesson 7 of this manual can be used as an aid
in modeling.
19. Were observations recorded to the nearest 5%? Opaci-
ty data are to be reported in 5% increments.
20. Sketch complete? For the sketch to be complete, it must
provide the following minimal pieces of information: sun loca-
tion, observer location, emission point, wind direction relative
to the observer, direction of the plume's travel at the point in
the plume where observations were made, and a north direc-
tional arrow. Other items that can be helpful in establishing
viewer prospective in the layout sketch are the inclusion of
surrounding landmarks (i.e., buildings, roads, parking lots, riv-
ers, etc).
21. Data calculations verified? The observer's data calcula-
tions should be checked to determine if the proper data evalua-
tion techniques were used and to verify that the correct results
were obtained for the resulting agency conclusions and/or ac-
tions.
22. General comments. The auditor should use this section to
state his or her findings with respect to the form evaluation.
Quality Assurance and Auditing • 12-9
-------
I Review Questions I
I I
I 1. Find the errors in the VEO form on the following page. |
i ,,"'*•-•...._.. • • -i
infcsUse theaudit form included in this lesson.) j
-- -* •
12-10 • Course 325, Visible Emission Evaluation Procedures
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Answers To Review
Questions
Lesson 1
1. Nuisance
2. Maximillian Ringelmann
3. The government
4. One night's sleep
5. Northwestern Laundry v. Des Moines
6. 1955
7. The Clean Air Act of 1965
8. EPA
9. Stays on areas that are accessible to the public and does not
cross a barrier or go through a gate.
10. SIPs (state implementation plans)
ll.A:2,B:3,C:l
Lesson 2
1. 40%
2. Can a shade of black really be used to describe white?
3. The obscuring power of a plume
4. 75%
5. a. number and size of particles
b. shapes of particles
c. color of particles
d. index of refraction of particles
6. A:2,B:5,C:1,D:6,E:3,F:4
7. Color contrast; luminous contrast
8. Maximize
9. Blue sky or white, cloudy sky; trees or a dark, textured
background
10. Opacity
11. Increases
/Answers to Review Questions • A-1
-------
Lesson 3
1. Black particles absorb visible light, and white, or non-black,
particles scatter visible light
2. a, black
3. Through smokestacks
4. b, negative
5. d, all the above (wind direction, a west wind, sun angle)
6. Smoke, soot, fly ash, dust, fumes, mist, gases, vapor
7. False. Dust particles are larger than smoke or fume particles
and settle to the ground more quickly
8. NO2, chlorine
9. Particles or droplets; generated either by homogeneous con-
densation of gases or as products of chemical reactions
10. Mechanical collectors, wet scrubbers, fabric filters,
electrostatic precipitators, afterburners
Lesson 4
1. Speed and direction
2. Determines the height the plume will attain before bending
horizontally; dilutes the plume
3. Temperature of plume; temperature profile of atmosphere;
wind speed; emission velocity
4. The amount of moisture present in the air compared to the
amount of moisture that could be in the air
5. More
6. Longer
7. 1:A,2:E,3:B,4:D,5:C
Lesson 5
1. b, opacity readings by Method 9
2. Increase
3. True
4. 7.5%
5. Sun position
6. Before steam plume formation or after "steam break"
7. Slant angle, sun position, point of observation in steam
plume, and observer position relative to rectangular stack
8. Positive; negative
9. Underestimate
10. Black
A-2 • Course 325, Visible Emission Evaluation Procedures
-------
11.140
12. 18,1
13. Mushrooming
14. The observer must demonstrate ability to assign opacity
reading in 5% increments to 25 different black and white
plumes with an error not to exceed 15% on any one
reading and an average error not to exceed 7.5% in each
category.
15. 6 months
Lesson 6
1. Qualitative
2. Is not
3. Pollutants not collected by a capture system that seep into
the atmosphere
4. Method 22 is more relaxed; the sun need only be out of the
observer's eyes. Method 22 specifies a distance (15 feet to
0.25 miles).
5. 100 lux
6. A rest break
7. 9A
8. Not limited to daylight hours, not subjective, slightly more
accurate than Method 9 under good conditions
9. More expensive, more staff and training needed, mini-
mum distances required, LIDAR assumes that the density
of particles is evenly distributed
Lesson 7
1. Wet-bulb temperature, dry-bulb temperature, relative
humidity, absolute humidity, and specific volume
2. WBT is the temperature on a wet-bulb thermometer.
DBT is the actual ambient temperature.
RH is the ratio of the amount of water vapor actually in
the air compared with the greatest amount there could
be at the given temperature.
AH is the amount of water vapor in a unit of air (expressed
as grains/lb or Ib/lb).
SV is the volume occupied by a unit mass of air, expressed
as ft3/lb.
3. Two
4. State point or state condition
Answers to Review Questions • A-3
-------
5. Will not
6. Long
7. b, an observer 100 feet away from a 75-foot stack
8. Ambient relative humidity = 60, exhaust gas humidity
ratio = 0.120, no steam plume will form
9. Greater than
10.22%
11.23%
12. Positive bias
13. Complex plume
14. Observe the plume while looking into the sun to find the
"steam break." Then with the sun at the observer's back
(proper sun position), observe the plume after the steam
break in accordance with Method 9.
15. The ammonia and sulphur oxides will react on the surface
of the water droplets and form dissolved ammonium
sulfate; then the water will evaporate into the atmosphere,
leaving ammonium sulfate particles.
16.0.25 miles
17. Negative, haze
18. Short daylight hours, late-night incineration, opacity
monitor downtime
Lesson 8
1. $25,000
2. d, 1345 EOT
3. Comments section
4. Operating mode
5. Describe emission point
6. NW
7. Is sufficient moisture present in the effluent to produce
water droplets at in-stack or ambient conditions? If enough
moisture is present, will water vapor condense to form drop-
lets before or after leaving the stack?
8. Describe plume background
9. a, b, d, (buildings, other emission outlets, a pond)
10.140
11. Place a dash (-) in the space and explain in the comment
section.
12. Forms interrelation
A-4 • Course 325, Visible Emission Evaluation Procedures
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Lesson 9
1. They could be reproduced many times.
2. U.S. Geological Survey maps
3. Measures distance from emission point
4. Determines vertical viewing angle
5. Measures wind speed
6. One has a wet cotton wick covering the bulb; relative
humidity
7. Color-corrected, coated lenses and a rectilinear field of view
8. Poor resolution and tonal registration of the recording
system
Lesson 10
1. Two medium-point, black pens; a clipboard
2. Yes; 25 percent, 50 percent, 75 percent
3. Look at the plume and determine its opacity.
4. Immediately look away from the plume and mark the
correct opacity
5. "Scratch!"
6. 4
7. No error of 4 or greater on the page and a total error less
than 38 for each type of smoke
8. Staring at the plume
9. 6 months
Lesson 11
1. VEO forms; certification records; notebooks, field logs,
etc.; photographs and videotapes
2. A fact witness needs no training.
3. What a witness will say and do on the stand
4. Attorney for plaintiff, attorney for defendant, court reporter,
experts for either side, the witness
5. Tell the truth, dress the part, relax, don't become angry,
answer as briefly as possible, do not answer compound
questions
6. Affidavit
7. No; yes
Answers to Review Questions • A-5
-------
Lesson 12
Mistakes on VEO form:
1. No north arrow drawn on source layout sketch
2. Shouldn't read an attached steam plume one stack-width
above opening (reading steam)
3. Ah* reading 100% because he or she was reading smoke
4. Expired certification
5. No explanation for missed reading during minute 25
A-6 • Course 325, Visible Emission Evaluation Procedures
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Additional Readings
These documents contain guidance on visible emission determina-
tions by trained observers (Reference Method 9):
Method 9 Field Observation Procedures
Visible Emissions Field Manual: EPA Methods 9 and 22, EPA 3407
1-92-004,12/93.
Guidelines for Evaluation of Visible Emissions:
Certification, Field Procedures, Legal Aspects and Background Ma-
terials, EPA 340/1-75-007,4/75.
EPA Visible Emission Inspection Procedures, S. 24,8/75.
Quality Assurance Handbook for Air Pollution Measurement Sys-
tems: Vol. IE Stationary Source-Specific Methods, Section 3.12 -
Method 9 Visible Determination of Opacity of Emissions from Sta-
tionary Sources, EPA 600/4-77-027b, 2/84.
Instructions for the Use of the VE Observation Form, EPA 340/1-
86-017.
Guide to Effective Inspection Reports for Air Pollution Violations,
EPA 340/1-85-019,9/85.
VE Observer Training and Certification (Method 9)
Technical Assistance Document: Quality Assurance Guideline for
Visible Emission Training Schools, EPA 600/4-83-011.
APT! Course 439: Visible Emission Evaluation Instructor/Student
Manuals.
Additional Readings • B-1
-------
Method 9 Policy Memorandum and Other
Background Information
Opacity Guidelines File: Policy Memoranda and Background
Information (compiled and updated annually for Course #
539 APTI Visible Emissions Instructors Workshop).
Public Comment Survey: Opacity Provisions Under Stan-
dards of Performance of New Stationary Sources of Air
Pollution, 8/75.
EPA Response to Remand Ordered by U.S. Court of Ap-
peals for the District of Columbia in Portland Cement Asso-
ciation v. Ruckelshaus, EPA 450/2-74-023,11/74.
Method 9 Technical Basis and Performance
Evaluation
Optical Properties and Visual Effects of Smokestack Plumes,
AP-30,5/72.
Measurement of the Opacity and Mass Concentration of
Particulate Emissions by Transmissometry, EPA 650/2-74-
128,11/74.
Evaluation and Collaborative Study of Method for Visual
Determination of Opacity of Emissions from Stationary
Sources, EPA 650/4-75-009,1/75.
B-2 • Course 325, Visible Emission Evaluation Procedures
-------
-------
United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park, NC
APTI/325-95-2
January 1995
Final Review Draft
Stationary Source Compliance Training Series
& EPA
VISIBLE EMISSION
EVALUATION PROCEDURES
COURSE
Workbook Manual
PROPERTY OF-
-------
Visible Emission
Evaluation Procedures
Course
Workbook Manual
APTI Course 325
Final Review Draft
Principal Author
Thomas H. Rose, Eastern Technical Associates
Style and Editing
Monica L. Loewy, The Leslie Group, Inc.
Peer Reviewers
Jay M. Willenberg, PE, Puget Sound Air Pollution Control Agency
Michael X DeBusschere, PE, Private Consultant
Benjamin Jones, Oregon Department of Environmental Quality
Frank P. Terranglio, Portland State University
Grant Project Officer
Kirk E. Foster, U.S. Environmental Protection Agency
Developed By
Environmental Institute for Technology Transfer
University of Texas at Arlington
EPA Training Grant T-902743
Report # and Date
APTI/325-95-2
January 1995
-------
Lesson 1
History
-------
Questions Addressed in This
Lesson
• How were air pollution problems
dealt with in court before there were
air pollution laws?
• How did Maximillian Ringelmann
quantify emissions in the late 19th
century?
• How are ruling bodies, statutory
law, and common law related?
Questions Addressed in This
Lesson (cont.)
• Which court cases have figured
prominently in the development of
air pollution control and what were
their rulings?
• How has the federal government
been involved in air pollution
control?
Course 325, Visible Emission Evaluation Procedures
1-1
-------
Early History
• Early United States—Tort (injury)
cases brought as nuisances
• 1859—Earliest U.S. case involving
municipal smoke ordinances: City of
New Orleans v. Lambert
• 1881—First smoke control ordinances
adopted by Cincinnati and Chicago
LIVE SHOT OF STEAMBOAT
Ringelmann Method
A method for quantifying emissions
according to the density of the smoke
observed
Course 325, Visible Emission Evaluation Procedures
1-2
-------
Ringeimann Cards
Agencies Using Ringeimann
Method
1899—American Society of
Mechanical Engineers
1904—U.S. Geological Survey
LIVE SHOT OF SMOKESTACKS
GRAPHIC 539G1D
Course 325, Visible Emission Evaluation Procedures
1-3
-------
Nuisance Laws
Ruling bodies recognized that the law
of nuisance alone was not adequate to
prevent air contamination.
1905—A Chicago court upheld the
view that "the emission of dense
smoke in populous communities is a
public nuisance."
Legislation and Common Law
Legislation (statutory law): statutes,
laws, rules, and regulations passed by
ruling bodies.
Common law: court interpretations
and rulings that enhance, modify,.and
temper these legislative actions.
State v. Tower (Missouri, 1904)
"...We have no hesitancy in holding
that it was entirely competent for the
Legislature to declare the emission of
dense smoke in the open air in a city
of 100,000 inhabitants a nuisance per
se."
Course 325, Visible Emission Evaluation Procedures
1-4
-------
Refinement of Air Pollution Law
1949—Penn Dixie Cement Corp. v. City
of Kingsport
Public health is the responsibility of
the government
Moses v. The United States
Any statute or ordinance must be
reasonable and must regulate
something injurious to health.
safety, or welfare
LIVE SHOT OF MEN IN MINE
GRAPHIC 539G1E
Course 325, Visible Emission Evaluation Procedures
1-5
-------
Other Court Cases
People v. Lewis (Michigan, 1891)—It is not
unreasonable to exempt certain classes
from regulation
City of Brooklyn v. Nassau Elect RR
(1899)—Penalty of $100 was collected for
burning soft coal
Cincinnati v. Burkhardt (1908)—Upheld use
of color scale to measure smoke
1910—A Rochester court upheld the use of
the Ringelmann scale
Northwestern Laundry v. Des Moines
The plaintiff claimed a Des Moines smoke
regulation was void because:
• The 14th Amendment guarantees due process
• The Ringelmann Chart was arbitrary
• .The standard required remodeling of almost
all the plaintiffs furnaces
• In the permit requirements for new
construction, officials had the discretion to
prescribe requirements
Northwestern Laundry v.
Des Moines (cont.)
The court dismissed the case because:
• The Constitution does not prohibit states or
municipalities from declaring dense smoke in
cities or populous neighborhoods a nuisance
• Harshness of such legislation is not a valid
reason for objection
• The Constitution does not disallow
regulations because they require
discontinuing using property or subject the
occupant to great expense trying to comply
Course 325, Visible Emission Evaluation Procedures
1-6
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LIVE SHOT OF WHITE SMOKE
GRAPHIC 539G1G
LIVE SHOT OF BLACK
SMOKE AND INSPECTOR
GRAPHIC 539G1H
LIVE SHOT - FIELD
OPERATIONS MANUAL
GRAPHIC 539G11
Course 325, Visible Emission Evaluation Procedures
1-7
-------
1965 Clean Air Act: Motor Vehicle
Emission Standards
1970-fARTH YEAR
Course 325, Visible Emission Evaluation Procedures
1-8
-------
Creation of the Environmental
Protection Agency (EPA)
Created in 1970 out of departments from other federal
agencies to consolidate environmental activities at a
federal level
• The National Air Pollution Control Administration,
from the Public Health Service
• Water Pollution Control, from the Department of
Agriculture
• Solid Waste and Radiation, from the Public Health
Service
Controlling Pollutants in Ambient Air
In 1971, EPA promulgated NAAQS for:
• Sulfur dioxide (SO2) • Paniculate matter
• Carbon Monoxide . lpMioJ
(CO) • Photochemical
• Nitrogen dioxide oxidants
(NO,)
Selected Cases: Portland
Cement Association (1973)
Course 325, Visible Emission Evaluation Procedures
1-9
-------
Selected Cases: Western Alfalfa
(1976)
Established rights of inspectors
to enter company property
Selected Cases: Donner Hanna
Inspectors were denied entry on the grounds
that:
• Method 9 must be used because there is no
legally adopted state method
• Since the inspectors intended to use a
method other than Method 9, they had no
usable method
Typical Regulation
No source shall suffer or permit to
emit into the atmosphere an
emission with an opacity equal to or
greater than 20 percent for 3 minutes
in any 1 hour
Course 325, Visible Emission Evaluation Procedures
1-10
-------
Lesson 2
Principles Of Visual
Emissions Measurement
-------
PRINCIPALS OF VISUAL
EMISSIONS
MEASUREMENT
Questions Addressed in This Lesson
, • How is equivalent opacity related to
Ringelmann numbers?
• What is plume opacity and what are the
properties that affect it?
• How is light affected by particles?
Questions Addressed in This Lesson
(cont.)
• What variables influence opacity
observations?
• How is the background for determining
opacity selected?
• What is the relationship between mass
emissions and opacity?
Course 325, Visible Emission Evaluation Procedures
2-1
-------
LIVE SHOT
OF MULTI-BUILDING PLANT
539G2B
Ringelmann Cards
mmmmmumm
•••••••-
•••••••l
Equivalent Opacity
The opacity equivalent to the
obscuring power of black smoke
characterized by a specific
Ringelmann grid
Course 325, Visible Emission Evaluation Procedures
2-2
-------
LIVE SHOT OF PLUMES
539G2D
Plume Opacity Definitions
The degree to which light
transmission through the diameter
of a plume is reduced
The degree to which the visibility of
a background viewed through the
diameter of a plume is obscured
Opacity
Opacity is the obscuring power
of the plume
Course 325, Visible Emission Evaluation Procedures
2-3
-------
Percent Opacity
Percent opacity = (1 - I/I0) x 100
I0= Incident light flux
I = Light flux leaving the plume
along the same path
Factors Influencing Opacity
Particle density
Particle size
distribution
Particle refractive
index
Particle color
Plume background
• Lighting
conditions
• Distance and
relative elevation
to stack exit
• Pathlength
• Sun angle
Electromagnetic Spectrum
Ultraviolet
(UV)
Infrared
(IR)
400 nm
Blue
550 nm
Yellow
Green
Visible Range
Course 325, Visible Emission Evaluation Procedures
2-4
-------
Particle Factors
• Number and size
• Shape
• Color
• Index of refraction
Light Factors
• Spectral characteristics
• Direction
• Amount (intensity)
Interactions Between Light and
Particles
• Transmission
• Scattering
• Reflecting
• Refracting
Course 325, Visible Emission Evaluation Procedures
2-5
-------
Transmission
Absorption
Scattering: Refraction and
Reflection
Refraction
Reflection
Course 325, Visible Emission Evaluation Procedures
2-6
-------
Scattering: Rayleigh and Mie
One Wavelength
One Wavelength
Rayleigh
Destructive Constructive
Interference Interference
Mie
Particle Size
Particles with diameters of 0.4 to 0.7
microns (u) have the greatest
scattering effect on sunlight
Plume Contrast
Color contrast—the difference in
color between the plume and the
background
Luminous contrast—the difference
in the light emanating from the
plume and the background
Course 325, Visible Emission Evaluation Procedures
2-7
-------
Selecting Background
A black plume should be read against a light
background
A white plume should be read against a dark, textured
background
Mass Emissions/Opacity
Relationship
r_ KRInm
P
C = Mass concentration
K = Particle size distribution
R = Particle density
T = Equivalent transmittance
P = Pathlength through the plume
LIVE SHOT OF LONG PLUME
539G2L
Course 325, Visible Emission Evaluation Procedures
2-8
-------
Lesson 3
Sources Of Visible
Emissions
-------
Sources
Questions Addressed in This
Lesson
• What determines whether emissions will be
black or white?
• How do the stack variables of size, height,
and shape affect opacity readings?
• What are common non-point sources of
fugitive emissions?
• Which mechanical processes are commonly
associated with fugitive emissions?
Questions Addressed in This
Lesson (cont.)
• How are visible emission components
classified?
• How are condensing and reacting plumes
distinguished?
• What devices are available for controlling
pollutant emissions and how does each
operate?
Course 325, Visible Emission Evaluation Procedures
3-1
-------
LIVE SHOT - EMISSIONS
539G3B
LIVE SHOT -
BLACK EMISSIONS
539G3C
LIVE SHOT -
WHITE EMISSIONS
539G3D
Course 325, Visible Emission Evaluation Procedures
3-2
-------
LIVE SHOT -
EMISSIONS SOURCES
539G3E
LIVE SHOT - TALL STACKS
539G3F
LIVE SHOT - WHITE PLUME
539G3G
Course 325, Visible Emission Evaluation Procedures
3-3
-------
LIVE SHOT - WIDE STACKS
539G3H
LIVE SHOT - SQUARE STACK
539G3I
Horizontal Emission Vents
Course 325, Visible Emission Evaluation Procedures
3-4
-------
Fugitive Emissions: Non-point
Sources
• Roof monitors • Doors
• Unpaved roads • Storage piles
• Gaps in duct work • Conveyors
Fugitive Emissions: Mechanical
Processes
Crushing
Drilling
Sanding
Vehicle
movement
Grinding
Sweeping
Demolishing
Materials handling
Visible Emission Components
• Smoke
• Soot
• Fly ash
• Dust
• Fumes
• Mist
• Gas
• Vapor
Course 325, Visible Emission Evaluation Procedures
3-5
-------
Smoke
Smoke is a visible effluent resulting
from incomplete combustion and is
composed of particles generally less
than 1 pm in diameter
Soot
Soot consists mostly of carbon
particles saturated with tar. It is
formed by the incomplete
combustion of carbon-containing
material.
Fly Ash
Fly ash is unburned material from
fuel combustion. A pure fly ash
plume is light-brown or cream
colored.
Course 325, Visible Emission Evaluation Procedures
3-6
-------
Dust
Oust consists of solid particles,
generally greater than 1 um in
diameter, released into the air by
processes such as drilling, crushing,
and grinding.
Fumes
Fumes consist of metal or metal oxide
particles less than 1 um in diameter.
The particles form when vapors
generated by high-temperature
metallurgical processes condense.
Mist
Mist consists of liquid particles or
droplets that contain pollutants in
solution or suspension. Droplet
sizes range from 2 to 200 um but are
usually about 10 um.
Course 325, Visible Emission Evaluation Procedures
3-7
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Gas
Gas is a fluid, like air, that has
neither independent shape nor
volume but tends to expand
indefinitely
Vapor
Vapor is the gaseous phase of a
substance that, at normal
temperature and pressure, is a liquid
or solid
Condensing and Reacting Plumes
Plumes that form in the atmosphere
Particulate matter formed when
homogeneous gases combine,
especially in the presence of water
Course 325, Visible Emission Evaluation Procedures
3-8
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LIVE SHOT - STEAM PLUMES
539G3K
Water Sources of Steam Plumes
• Drying operations
•
• Combustion of hydrogen or HG fuels
• Air pollution control devices
• Evaporation of water
• Thermal processes
LIVE SHOT -
REACTING PLUMES
539G3L
Course 325, Visible Emission Evaluation Procedures
3-9
-------
Control Devices for Pollutant
Emissions
• Mechanical collectors
• Wet scrubbers
• Fabric filters
• Electrostatic precipitators
• Afterburners
Mechanical Control Devices
Settling chambers
Cyclones
Wet venturi scrubbers
Wet Scrubbers
• Trap particles and gases
• Collection efficiency can be high
• Often create steam plumes
• Often followed by mist eliminators
Course 325, Visible Emission Evaluation Procedures
3-10
-------
LIVE SHOT • FABRIC FILTERS
539G3M
Electrostatic Precipitators
Precipitation rate depends on:
• The electrical properties of the particles
• The electrical properties of the gas
.stream
• Velocity of the gas stream
• The voltage
• The design of the charging and collection
plates
Afterburners
Direct-flame burners
Catalytic burners
Course 325, Visible Emission Evaluation Procedures
3-11
-------
Lesson 4
Meteorology
-------
Meteorology
Questions Addressed in this Lesson
• How do wind speed and wind direction affect plume
observations?
• What factors determine the shape of a smoke
plume?
• How do sky conditions affect a plume and its
background?
• What is relative humidity and how does it affect
opacity?
Wind Description
• Speed
• Direction
Course 325, Visible Emission Evaluation Procedures
4-1
-------
Wind Speed Effects
Wind speed determines the height a
plume will reach before it bends
Wind speed affects opacity
measurements by diluting the plume
Wind Direction Effects
• Wind direction helps determine the
location of the observation (the
observer's line of sight)
• Wind direction might vary, especially.
with light winds
Observer's Position
A
Course 325, Visible Emission Evaluation Procedures
4-2
-------
Plume Shape Factors
• Plume temperature
• Vertical temperature profile of the
atmosphere
• Wind speed
• Emission velocity
Plume Shapes
• Coning
• Lofting
• Looping
• Fanning
* Fumigating
Coning Plume
Course 325, Visible Emission Evaluation Procedures
4-3
-------
Lofting Plume
Looping Plume
Fanning Plume
Course 325, Visible Emission Evaluation Procedures
4-4
-------
Fumigating Plume
Sky Cover Conditions
• Whether the plume is in a shadow
or in direct sunlight
• The color of the sky (or clouds)
• Intermittent cloud cover
LIVE SHOT -
INTERMITTENT CLOUDS
Course 325, Visible Emission Evaluation Procedures
4-5
-------
Relative Humidity
Factors Affecting Relative
Humidity
• Air temperature •
• Amount of air moisture
Relative Humidity Affects Opacity
• Creating fog, mist, or haze
• Creating rain
• Affecting the formation and
persistence of steam plumes
Course 325, Visible Emission Evaluation Procedures
4-6
-------
LIVE SHOT - PLANT AND FOG
539G4J
Summary: Factors Affecting
Observations
• Wind speed/direction
• Observer's position
• Plume shape
• Sky cover conditions
• Relative humidity
Summary: Plume Shapes
Coning
Lofting
Looping
Course 325, Visible Emission Evaluation Procedures
4-7
-------
Summary: Plume Shapes (cont.)
Fanning
Fumigating
p^XD
Course 325, Visible Emission Evaluation Procedures
4-8
-------
Lesson 5
Method 9 Requirements
-------
Method 9
Requirements
Questions Addressed in This Lesson
. • Why is Method 9 the preferred technique
for evaluating emissions opacities?
• How does a change in stack diameter
affect opacity readings?
• How did the Portland Cement Association
v. Ruckelshaus case change Method 9
procedures?
Questions Addressed in This Lesson
(cont.)
• In observing a plume, which variables are
controllable and which are uncontrollable?
• What are the correct procedures for
performing a Method 9 observation?
• What are the requirements to become a
Method 9-certified observer?
Course 325, Visible Emission Evaluation Procedures
5-1
-------
Portland Cement Remand
June 29,1973
| Portland Cement Association v. Ruckelshaus
i
i Promulgation
' November 22,1974
Precedence of Method 9
EPA established that Method 9-type
observations remain presumptively valid and
correct over continuous emissions monitors
(CEMs) or transmissometers
Precedence of Method 9 (cont.)
EPA recognized that because CEMs and
transmissometers are located within the
stack, they might not represent the opacity
at or above the emission point
Course 325, Visible Emission Evaluation Procedures
5-2
-------
Opacity Varies With Stack Diameter
Opacity Varies With Stack Diameter
(cont.)
Opacity Standards
EPA reconsidered the opacity limits and
changed Portland cement plant standards
from 10% to 20%
Course 325, Visible Emission Evaluation Procedures
5-3
-------
EPA Opacity Policy: First Element
i Opacity limits are independently enforceable
j standards
EPA Opacity Policy: Second Element
I Opacity and mass/concentration standards
' for the same source ensure use of
i state-of-the-art controls to reduce emissions
EPA Opacity Policy: Third Element
Opacity standards violations can signify
improper operation and/or maintenance of
control systems
Course 325, Visible Emission Evaluation Procedures
5-4
-------
Changes in EPA Procedures:
Observer Accuracy
EPA determined that Method 9-certified
observers are able to read opacity
consistently with positive errors not
exceeding 7.5% based on averaged sets of
24 readings
Changes in EPA Procedures:
Error Analysis
A method's accuracy must be taken into
account when determining possible
violations of opacity standards
Changes in EPA Procedures:
Averaging
eid method
• Record readings
• Count violations
• Multiply by time factor
New method
• Record readings
• Average groups of 24
Course 325, Visible Emission Evaluation Procedures
5-5
-------
Changes in EPA Procedures:
Sun-Observer Relationship
\ ^-^—*^-s*
Changes in EPA Procedures:
Observation Slant Angle
Apparent
opacity
Apparent
opacity
Changes in EPA Procedures:
Steam Plumes
Course 325, Visible Emission Evaluation Procedures
5-6
-------
Changes in EPA Procedures:
Smoke Generators
EPA standardized certification procedures by
establishing criteria for generators and
opacity-measuring equipment used in
training and certifying observers
Method Changes
The current version of Method 9 has
remained essentially unchanged since its
promulgation in 1974. In 1987 two minor
.changes occurred.
Controllable Variables
• Angle of observer with respect to the
plume
• Angle of observer with respect to the sun
• Point of observation of attached and
detached steam plumes
• Angle of observation for rectangular
stacks
Course 325, Visible Emission Evaluation Procedures
5-7
-------
Uncontrollable Variables
• Luminous contrast
• Color contrast
High-Contrast Backgrounds
A plume viewed against a contrasting
background:
• Is most visible
• Presents the greatest apparent
opacity
Low-Contrast Backgrounds
• As the amount of contrast decreases,
negative bias increases
• Opacity will tend to be reported at a lower
level than what actually exists
Course 325, Visible Emission Evaluation Procedures
5-8
-------
Error Magnitude
Black plumes
• 100% with positive error < 7.5%
• 99% with positive error < 5%
White plumes
• 99% with positive error < 7.5%
• 95% with positive error < 5%
Positive Error
EPA does not define a specific positive
observational error but warns that accuracy
must be taken into account
Principle
The method states:
• The opacity of emissions from stationary
sources is determined by a qualified
observer
• The observer must be certified before
completing observations for record
Course 325, Visible Emission Evaluation Procedures
5-9
-------
Applicability
In addition to sources subject to NSPS,
Method 9 can be used to evaluate:
• Sources in states where Method 9 has been
incorporated by reference into the SIP
• Sources in states where the SIP is vague as
to the exact method
Procedures: Observer's
Position Relative to the Sun
For an observer to perform Method 9
observations correctly, the sun must be in a
140* sector to the observer's back
Procedures: Line of Sight
Course 325, Visible Emission Evaluation Procedures
5-10
-------
Procedures: Line of Sight (cont.)
Procedures: Multiple Stacks
Procedures: Minimum Requirements
for Field Records
Name of the plant
Emission location
Type of facility
Observer's name and
affiliation
Date and time
Estimated wind speed
Approximate wind
direction
Description of sky
conditions
Estimated distance
to the emission
location
Plume background
Course 325, Visible Emission Evaluation Procedures
5-11
-------
Procedures: Sketch
Procedures: Point of Greatest
Opacity
I
Plume Mushrooming
Course 325, Visible Emission Evaluation Procedures
5-12
-------
Procedures: Attached Steam Plumes
Distance from emission outlet
to point of observation
Procedures: Detached Steam Plumes
Procedures: Recording Observations
• The observer records the opacity to the
nearest 5% every 15 seconds for a
minimum of 6 minutes
• The observer must not stare at the plume;
momentary glances work best
Course 325, Visible Emission Evaluation Procedures
5-13
-------
Procedures: Data Reduction
The average opacity is the average
of 24 consecutive observations
taken at 15-second intervals
Procedures: Calculation of Opacity
• Calculate the 6-minute average by adding
the 24 consecutive opacity readings and
dividing by 24
• Any 24 consecutive readings can be used
for this calculation
Procedures: Certification Requirements
• Test required
• 5% increments
• 25 black and 25 white plumes
• Error NTE 15% on any one reading
• Average error NTE 7.5% in each category
Course 325, Visible Emission Evaluation Procedures
5-14
-------
Procedures: Period of Certification
Method 9
Observer
Certificate
(Expires in six months)
Course 325, Visible Emission Evaluation Procedures
5-15
-------
Lesson 6
Other Methods
-------
Other Methods
EPA Reference Method 22
Visually determines existence and duration of
fugitive emissions from material-processing
sources.
Method 22
• Qualitative
• Determines presence or absence of visible
emissions
• Used to determine duration of fugitive
emissions
Course 325, Visible Emission Evaluation Procedures
6-1
-------
Fugitive Emissions
• Escape capture by exhaust hoods in process
equipment
• Are emitted during material transfer
• Are emitted from buildings that house
material-processing or material-handling
equipment
• Are emitted directly from process equipment
I
Method 22—Training
• Does not require certification
i • Does require training or knowledge
Method 22—Applicability
Frequency of visible emissions from
specified stationary sources
Frequency of visible emissions from
smoke flares
Course 325, Visible Emission Evaluation Procedures
6-2
-------
Method 22 Terms
Emission frequency
Emission time
Fugitive emissions
Smoke emissions
Observation period
Required Equipment
Two accumulative-type stopwatches with
divisions of at least 0.5 seconds
A light meter capable of measuring
illuminance in the 50 to 200-1 ux range
(required for indoor observations only)
Procedure
The observer should determine potential
emission points
The observer must be at least 15 feet, but no
more than 0.25 miles, away from the source
When observing outdoors the sun must not
be directly in the observer's eyes
Course 325, Visible Emission Evaluation Procedures
6-3
-------
Field Records
Data required on indoor and outdoor records:
• Company name
• Industry
• Process unit
• Observer's name and affiliation
• Date
• Sketch showing process unit and emission
points
Indoor Form
Additional data required:
• Type of lighting
. • Location of lighting
• Intensity of lighting
Outdoor Form
Additional data required:
• Wind speed
• Wind direction
• Sky conditions
• Sun location relative to observer (in
sketch)
Course 325, Visible Emission Evaluation Procedures
6-4
-------
Indoor Lighting Requirements
A light meter must be used to measure the
level of illumination
The light meter must measure the
illumination as close as possible to the
emission source
The illumination must be greater than 100 lux
Timing
Clock time
Observation period stopwatch
Accumulated emission stopwatch
Observation Period
i
Proving compliance
Proving noncompliance
Course 325, Visible Emission Evaluation Procedures
6-5
-------
Observer Rest Breaks
Visual Interference
If the view of the fugitive emissions is
obscured to such a degree
-------
Calculation Regulations
Emission frequency (as a percentage) =
Accumulated emission time x 100
Observation period (or minimum
observation period)
Live Shot
LIDAR Advantages
The method is not limited to daylight hours
It is not a subjective method
Under proper conditions, it can be slightly
more accurate than Method 9
Course 325, Visible Emission Evaluation Procedures
6-7
-------
LIDAR Disadvantages
• The method is orders of magnitude more
expensive than Method 9 for equipment
• It requires more manpower and training than
Method 9
• Minimum distances and safety procedures
are required
• LIDAR assumes that the density of particles
in the air is uniformly distributed
SIP Methods
• Many SIP rules predate the 1974
promulgation of Method 9
• The SIP might be at odds with Method 9's
6-minute average (e.g., time aggregation
SIPs)
Method Priority
If the state has gone through formal
rulemaking and promulgation of the test
method, the SIP should be used
If the test method is not clearly stated in the
SIP or if the state has not gone through
formal rulemaking. Method 9 should be used
Course 325, Visible Emission Evaluation Procedures
6-8
-------
Summary of Other Emission
Observation Methods
• EPA Reference Method 22
• LIDAR
• SIP methods
Course 325, Visible Emission Evaluation Procedures
6-9
-------
Lesson 7
Special Field Problems
-------
Special Field Problems
Questions Answered in This Lesson
• What factors affect steam plume
formation?
• What conditions must be known to predict
the occurrence of a steam plume?
• How are ambient relative humidity and
exhaust gas humidity ratio determined?
• How are Method 9-related line-of-sight
problems resolved?
Questions Answered in This Lesson
(cont.)
• How are positively biased observations
avoided?
• How are complex plumes observed?
• In what circumstances are nighttime
observations made?
Course 325, Visible Emission Evaluation Procedures
7-1
-------
Common Observation Problems
• Predicting steam plume formation
• Line-of-sight problems (including slant
angle)
• Complex plumes
• Extreme distances
• Nighttime observations
539g7b
Factors Affecting Steam Plume
Formation
• Dry-bulb temperature
• Wet-bulb temperature
• Relative humidity
• Absolute humidity
• Specific volume
Course 325, Visible Emission Evaluation Procedures
7-2
-------
Stack State Point
HB_ 0.62(MC)
HR~ 1-MC
HR = Humidity ratio (Ib. water vapor/lb. dry air)
MC = Percentage moisture content, expressed
as a decimal
Psychrometric Chart
Barometric Pressure
VP = SVP - (3.57 x KPJP.JV Tw)
•&•
SVP = Saturated vapor pressure (in. Hg) at
wet-bulb temperature
Td = Dry-bulb temperature ('F)
Tw = Wet-bulb temperature ('F)
VP = Vapor pressure of H,O
Prt, = Barometric pressure
i
Course 325, Visible Emission Evaluation Procedures
7-3
-------
Line of Sight
The observer's line
of sight is
perpendicular to
the long axis of a
rectangular outlet
I Line of sight
Observer
_
Sun
Top View
One
plume
diameter
Slant Angle
Opacity Values Adjusted for Slant Angle
Measured Slant angle, degrees
opacity
95
90
85
80
75
70
65
0
95
90
85
80
75
70
65
10
95
90
85
80
75
70
64
20
94
89
83
78
73
68
63
30
93
86
81
75
70
65
60
40
90
83
77
71
65
60
55
50
85
77
71
65
59
54
49
60
78
68
62
55
50
45
41
aa-a
OJ-OMI
Course 325, Visible Emission Evaluation Procedures
7-4
-------
Adjusted
Measured
opacity
60
55
50
45
40
35
30
**•
Opacity Values (cont.)
Slant angle, degrees
0
60
55
50
45
40
35
30
MM
10
59
55
50
45
40
35
30
20
58
53
48
43
38
33
29
30
55
50
45
40
36
31
27
40
50
46
41
37
32
28
24
50
45
40
36
32
28
24
21
60
37
33
29
26
23
19
16
OMMi
Adjusted Opacity Values (cont.)
Measured Slant angle, degrees
opacity
k 25
f 20
^ 15
10
5
0
0
25
20
15
10.
5
0
10
25
20
15
10
5
0
20
24
19
14
9
4
0
30
22
18
13
9
4
0
40
20
16
12
8
3
0
50
17
13
10
7
3
0
60
13
t1
8
5
3
0
Hfr7-u
07-OMB
Complex Plumes: Water Retention on
Particles
Course 325, Visible Emission Evaluation Procedures
7-5
-------
Complex Plumes: Reacting Plumes
Some gases that do not react when mixed
under dry conditions will react when in
the presence of water droplets
When the water evaporates, particulate
matter remains
Reacting Plume
Reading Steam Plumes
Course 325, Visible Emission Evaluation Procedures
7-6
-------
Extreme Distances
EPA has suggested that 0.25 mile is the
maximum viewing distance
It might be necessary to exceed this limit
for certain stacks
Nighttime Observations
• Short days
• Incineration at the end of the day
• Industry attempting to avoid violation
detection
Nighttime Observations: Experiments
• Starlight scope
• Infrared
Course 325, Visible Emission Evaluation Procedures
7-7
-------
Nighttime Observations: Procedures
Choose a clear night (no fog)
Maintain night vision
Select light behind source
Course 325, Visible Emission Evaluation Procedures
7-8
-------
Lesson 8
Documentation
-------
Documentation
Questions Answered in This
Lesson
• How are violations of visible emission
(VE) standards assessed?
• What is .the observer's role in
documenting VE observations (VEOs)?
• What is the VEO form and how is it
used?
• What is the fine for violating opacity
standards from an NSPS or a SIP?
Documentation
The example form and documentation
given in the Federal Register are not
always adequate
The new visible emissions
observation form was designed to fill
this gap
Course 325, Visible Emission Evaluation Procedures
8-1
-------
Documentation (cont.)
The new visible emissions
observation form contains all
required information as well as
supplementary information
Information
IOCATON
Process and Control Equipment
80fi£X
me/wcm?
OPOMMGUOOE
WDJMPPffK
Course 325, Visible Emission Evaluation Procedures
8-2
-------
Emission Point Identification
Emissions Description
>~&'J'Jff" I *W*lIB8BOKIi*Ul* . .
&AflfE lATTAOpQ DTOCHm tf Mt
, n4**—~
Observation Conditions
».^3g7zaay
Course 325, Visible Emission Evaluation Procedures
8-3
-------
Observer's Position and Source
Layout
Additional Information
ADOOIOMAl NFOBUAtlQM
Observation Information
lOBSESWMlONOAliI STAIR TICI BO HUE
Course 325, Visible Emission Evaluation Procedures
8-4
-------
Data Set
Sg
MiH
i'l"'
£
3
•
0
30
'2S-
40
3Q
,15
35}
20
35
3O
30
40
a
40
~J0
45
30
30
3f
>•»
COMMENTS'
'
->
**
:'•
. . -..',
Interrupted Reading
12
13
,14
35
1c
;.-": " -. ":,- ., . i -•'• . ' - .'
; fffr&f&M$PU(M£
-••••^-^%!:^f:.~ ;:• •;
-., ~_ S£
H
•
6-Minute Block
20
21
22
2S
24
25
A?
-af
.a?
:a?'
«.
•»
j&
20
25
t2S.
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'20-
35
'ff
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30
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40.
35-
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•.;•, '.:•--• -•' -. •• '"
./ • -.... ;-;„ •.
a»»
•
»
Course 325, Visible Emission Evaluation Procedures
8-5
-------
Observer Data
f.f99f "
Forms Interrelation
CONTINUED ON VEO FORM NUMBER -
Completed
VEO Form
Course 325, Visible Emission Evaluation Procedures
8-6
-------
-------
Equipment
Questions Answered in This Lesson
• What are the recommended (not required)
supplies and equipment for Method 9?
• For what purpose are VEO form
reproductions used?
• How are compasses used in VE
observations?
• What does a rangefinder measure?
Questions Answered in This Lesson
(cont.)
• Vertical viewing angles can be determined by
using what devices?
• Why are drawing tools necessary in VE
observations?
Course 325, Visible Emission Evaluation Procedures
9-1
-------
Method 9 Equipment
Method 9 does not have specific
equipment/supply requirements but does
have measurement requirements
Recommended Supplies
• A clipboard
• Several black ballpoint pens
• Several large rubber bands
• High-quality reproductions of the VEO form
Live shot of timer
Course 325, Visible Emission Evaluation Procedures
9-2
-------
Compass
Live shot of map
Live shot of a rangefinder
«L
Course 325, Visible Emission Evaluation Procedures
9-3
-------
Clinometric Devices
Drawing Tools
Anemometer
Course 325, Visible Emission Evaluation Procedures
9-4
-------
Sling Psychrometer
Wet bulb G* Dry bulb.
Binoculars
Cameras and Accessories
A camera should be used to document
emissions before, during, and after opacity
determination
A photo logbook is necessary for good
documentation
Course 325, Visible Emission Evaluation Procedures
9-5
-------
Video
Most video equipment is not suitable for VE
documentation
If a plume must be taped, 3/4-inch or greater
Super VHS or high-resolution 8-mm should
be used
Computers and Software
Several software programs are available to
assist a VE observer. These programs include:
• Spreadsheets
• U.S. Naval Observatory's ICE
• Instack
• Opacicalc
Course 325, Visible Emission Evaluation Procedures
9-6
-------
Lesson 10
Field Training
And Certification
-------
Field Training and
Certification
Questions Answered in This Lesson
When and where do field training and
certification exercises take place?
Name the five elements of training and
certification.
How does an observer trainee receive
certification?
Questions Answered in This Lesson
(cont.)
• What is the certification test-run form?
How is it used?
• What are the two most common mistakes
when making smoke observations?
Course 325, Visible Emission Evaluation Procedures
10-1
-------
! LIVE SHOT OF FIELD TRAINING
LIVE SHOT OF TRAINEE
Field Training and Certification
Process
• Demonstration of standards
• Practice plumes
• Testing for black and white
• Grading
• Retesting, if necessary
Course 325, Visible Emission Evaluation Procedures
10-2
-------
LIVE SHOT OF THREE PRACTICE
PLUMES
Testing
A trainee must assign opacity values
to 25 black plumes and 25 white
plumes
Certification Requirements
The test must be completed with no
single error exceeding 15% opacity
and with a total average error less
than 7.5% opacity
Course 325, Visible Emission Evaluation Procedures
10-3
-------
Certification Test-Run Form
—OH I I I I I I I I I I I I I I I I I I I I I I I I I I
_£•!
x*JJi»S>.».,
Field Test Procedures
"Reading number 1"
"Mark"
"Reading number 2"
"Mark"
LIVE SHOT OF FIELD TEST
Course 325, Visible Emission Evaluation Procedures
10-4
-------
Field Test Completion
Check to be sure that your test has:
• One answer on every line
• Neatly marked changes
• The signed acknowledgment
Then turn in the white copy.
Form Correction
As the answers
are announced.
the yellow form
should be
marked
Grading
Readings
(2u) 25 30
(fO) 25 30
(|6) 25 30
(|0) 25 30
35 40
35 40
3£ 40
35 40
Error
1
2
3
4
at-to-if
d74Mi
Course 325, Visible Emission Evaluation Procedures
10-5
-------
Did You Pass?
If the answers to the following three questions
are all yes, turn in the yellow copy
• Were all answers within 15% opacity (i.e.,
error of 3 or less)?
• Was the total error less than 38 for black
smoke?
• Was the total error less than 38 for white
smoke?
Retesting Criteria
• There is an error of 4 or greater anywhere
on the page
• The total error on either of the sets is
more than 37
Common Errors
There are two common errors in
certification:
• Staring at the plume
• Reading the plume at the wrong time
Course 325, Visible Emission Evaluation Procedures
10-6
-------
Certification Period
The certification is valid for 6 months
Course 325, Visible Emission Evaluation Procedures
10-7
-------
Lesson 11
Presentation Of Opacity
Data In Court Cases
-------
Presentation of Opacity
Data in Court Cases
Questions Answered in This Lesson
• What types of evidence are used in court
cases concerned with emissions violations?
• What is the role of witnesses in such court
cases?
• How are depositions and affidavits used in
court cases concerned with emissions
violations?
• +tow is a witness' testimony used in court?
i
•
Types of Evidence
• VEO forms
• Certification records
• Notebooks, field logs, etc.
• Photographs and videotapes
Course 325, Visible Emission Evaluation Procedures
11-1
-------
Types of Witnesses
• Fact witness
• Trained witness
• Expert witness
Trained Witness
VE observers can be introduced as trained
witnesses
The observer's credentials are verified and
the observer testifies to the measurements
made and the procedures followed
Expert Witness
An expert witness is one who has specialized
knowledge of issues and principles in the
pertinent subject matter
Course 325, Visible Emission Evaluation Procedures
11-2
-------
Depositions
Defense attorneys look for:
• Raws in the prosecution's case
• Type of witness
- The witness' actual knowledge
• The witness' skills
• Opportunities to intimidate the
prosecution
Deposition Documents
A deposition is often taken duces tecum,
which means that the witness is required to
bring certain documents to the deposition
Deposition Preparation
The witness should discuss the deposition
process with the prosecuting attorney before
attending the deposition
Course 325, Visible Emission Evaluation Procedures
11-3
-------
Deposition Attendance
• Attorney for the plaintiff
• Attorney for the defendant
• The court reporter
• Experts for either side
• The witness
Deposition Procedure
• The opening questions should set the tone
of the deposition and relax the witness
• The deposition is part of the court record,
and the witness is subject to perjury laws
Deposition Testimony Rules
• The witness should listen carefully to the
questions
• The witness should wait a few seconds
after a question to respond
• The witness should always tell the truth
• The witness should speak clearly and
slowly
Course 325, Visible Emission Evaluation Procedures
11-4
-------
Deposition Testimony Rules (cont.)
• The witness should answer any sensible
question that is not a compound question
• The witness should never argue with the
opposing attorney
• The witness should answer all questions
as briefly as posible
• If the witness needs a break, he or she
should ask for one
Deposition Testimony Rules (cont.)
If the witness' attorney objectsto a question,
the witness should:
• Let things settle down between the
attorneys
• Ask that the question be repeated by the
court reporter before answering it (if
required)
Deposition Testimony
• The opposing attorney's job is to find flaws,
and any area is fair game
• After the deposition, the witness should
review, revise (if necessary), and return
promptly a copy of the transcript
Course 325, Visible Emission Evaluation Procedures
11-5
-------
Affidavits
An affidavit is a document signed under
penalty of perjury that gives the witness'
background and his or her assertions that
will be made in court
The witness should consult with his or her
attorney when preparing an affidavit
Court Testimony
• VE observers are usually called to testify
about the observed opacity levels
• The observer will be asked about the
methods and procedures used
• The observer does not need to remember
actual opacity values
Court Testimony (cont.)
The witness should follow deposition rules
and observe additional guidelines
Course 325, Visible Emission Evaluation Procedures
11-6
-------
Court Testimony (cont.)
Any VE observer called to testify in a court
case should always tell the truth
Course 325, Visible Emission Evaluation Procedures
11-7
-------
Lesson 12
Quality Assurance
And Auditing
-------
Quality Assurance and
Auditing
Questions Addressed in This Lesson
• What is the purpose of the data audit
and quality assurance procedures?
• During a data audit, what form is
evaluated?
i
Preparation for the Audit
• Use a standard audit form
• Information regarding the source and the
observer should be copied from the VEO
form to the audit form
Course 325, Visible Emission Evaluation Procedures
12-1
-------
Certification Date
Acceptable Sun Angle
Check the horizontal sun angle
Horizontal Sun Angle Worksheet
I.D. a.
Analysis performed by:.
Date:
360,0
270
Course 325, Visible Emission Evaluation Procedures
12-2
-------
Acceptable Sun Angle
Check the vertical sun angle
Vertical Sun Angle Worksheet
Evaluated by:
OBSERVER
Acceptable Sun Angle
Use the ICE Program for verification
Course 325, Visible Emission Evaluation Procedures
12-3
-------
Viewing the Background
Was the background viewed
perpendicularly to the vent's long
axis?
Describing the Emission Point
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Viewing the Background
Was the background viewed across
the plume's narrow axis?
Course 325, Visible Emission Evaluation Procedures
12-4
-------
Plume Background
Was the plume evaluated against a
contrasting background?
Plume Background (cont.)
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Plume Condition
Was the plume continuous?
I
Course 325, Visible Emission Evaluation Procedures
12-5
-------
The 6-Minute Average
Was the 6-minute average complete?
The 6-Minute Average (cont.)
20
21
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23
24
25
30
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20
20
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Positive Observational Errors
Were positive observational errors
taken into account?
Course 325, Visible Emission Evaluation Procedures
12-6
-------
539G12D
Data Gaps: Interrupted Reading
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Source Dimensions
Is the information regarding source
dimensions sufficient?
Bourse 325, Visible Emission Evaluation Procedures
12-7
-------
Distance of Observer from Emission
Source
Was the distance of the observer
from the emission source recorded?
Reading Height Above Source
Was the height above the source at
which readings were made recorded?
Reading Height Above Source (cont.)
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Course 325, Visible Emission Evaluation Procedures
12-8
-------
Wind Speed and Direction
Was the wind speed recorded?
Was the wind direction recorded?
Collaborative Readings
Were collaborative readings taken?
Sky Conditions
Were sky conditions described?
Course 325, Visible Emission Evaluation Procedures
12-9
-------
Interferences
Were any interferences present?
Steam Plume
Was a steam plume present?
539G12E
Course 325, Visible Emission Evaluation Procedures
12-10
-------
Steam Plume
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Recording Observations
Were observations recorded to the
nearest 5 percent?
Source Layout Sketch
Course 325, Visible Emission Evaluation Procedures
12-11
-------
Data Calculations Verification
Were the data calculations verified?
VEO Form Evaluation
Any general comments about the
completed VEO form?
Course 325, Visible Emission Evaluation Procedures
12-12
-------
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