April 1983 1 Section 3.12.0 

United States Environmental Monitoring Systems 

Environmental Protection Laboratory 

Agency Research Triangle Park NC 27711 

GEPA 

Research and Development EPA-600/4-77-027b Feb. 1984 

Section 3.12 

Method g-visible 

Determination of the 

Opacity of Emissions from 

Stationary Sources 

Section 

Summary 

Method Highlights 

Method Description 

1. Certification and Training of 

Observers 

2. Procurement of Apparatus and 

Supplies 

3. Preobservation Operations 

4. On-Site Field Observations 

5. Postobservation Operations 

6. Calculations 

7. Auditing Procedures 

8. Reference Method 

9. References and Bibliography 

10. Data Forms 

Outline 

Summary 

Many stationary sources discharge 

plume-shaped visible emissions into 

the atmosphere. Method 9 (EPA 

Reference Method) is used to 

determine the opacity of this plume by 

qualified observers. The method 

includes procedures for the training 

and certification of observers and 

procedures to be used by these 

observers in the field to determine 

plume opacity. This section of the 

Quality Assurance (QA) Handbook 

primarily concerns procedures used by 

the observers. Only Section 3.12. I 

reviews the training and certification 

procedures, which are described in 

Reference 1. 

Number 

Documentation of Pages 

3.12.0 2 

3.12.0 2 

3.12.1 5 

3.12.2 2 

3.12.3 2 

3.12.4 18 

3.12.5 2 

3.12.6 7 

3.12.7 2 

3.12.8 5 

3.12.9 1 

3.12.10 9 

The appearance of a plume as 

viewed by an observer depends 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 respect to 

the plume; angle of the observer with 

respect to the sun; point of 

observation of attached and detached 

steam plumes and angle of the 

observer with respect to a plume 

emitted from a rectangular stack with 

a large length to width ratio. The 
Section 3.12.0 2 April 1983 

method includes specific criteria 

applicable to these variables. 

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. Research studies 

of plume opacity have demonstrated 

that a plume is most visible and 

presents the greatest apparent opacity 

when viewed against a contrasting 

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. 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. 

Method 9 is applicable for the 

determination of the opacity of 

emissions from stationary sources 

pursuant to 60.1 l(b). Studies have 

been undertaken to determine the 

magnitude of positive errors that 

qualified observers can make while 

reading plumes under contrasting 

conditions and using the procedures 

specified in Method 9. The results of 

these studies, which involve a total of 

769 sets of 25 readings each, are as 

follows: 

1. In the case of black plumes, 100 

percent of the sets were read 

with positive error of less than 

7.5 percent opacity; 99 percent 

were read with a positive error of 

less than 5 percent opacity. 

2. In thacase of white plumes, 99 

percent of the sets were read 

with a positive error (higher 

values) of less than 7.5 percent 

opacity; 95 percent were read 

with a positive error of less than 

5 percent opacity. 

The positive observational error 

associated with an average of twentyfive readings is therefore established. 

The accuracy of the method must be 

taken into account when determining 

possible violations of applicable 

opacity standards. 

Note: Proper application of Method 

9 by control agency personnel in 

determining the compliance status of 

sources subject to opacity standards 

often involves a number of 

administrative and technical 

procedural steps not specifically 

addressed in the Federal Register 

method. Experience has shown these 

steps are necessary to lay a proper 

foundation for any subsequent 

enforcement action. To clearly 

delineate items that are EPA 

procedural policy and requirements of 

the Method 9 from additional quality 

assurance procedures, a wording 

scheme was developed. All of 

Sections 3.12.1, 3.12.2, 3.12.3, 

3.12.6, and 3.12.7 are suggested 

quality assurance procedures except 

where noted as EPA policy or Federal 

Register citings. Section 3.12.4 notes 

EPA requirements with directive 

statements using words such as shall, 

should, and must. QA procedures are 

noted either with suggestive 

statements using words such as 

recommended, suggested, and 

beneficial or by stating that the entire 

subsection is recommended. The use 

of these QA procedures should 

provide a more consistent program, 

improved observer effectiveness and 

efficiency, and improved data 

documentation. 

Method Highlights 

Section 3.12 primarily describes 

Method 9 procedures for the 

determination of plume opacity. 

Section 3.12.1 briefly reviews the 

quality assurance procedures to be 

used in the observer training and 

certification procedures described in 

detail in Reference 1. The remaining 

sections describe the field procedures. 

Section 3.12.10 provides blank data 

forms recommended for use by the 

observer and other personnel, as 

required. Partially completed forms, 

are included in Sections 3.12.1 

through 3.12.7 of the Method 

Description. Each form in Section 

3.12.10 has a subtitle (e.g., Method 9, 

Figure 2.1) to allow easy reference to 

the corresponding completed form. 

The following paragraphs present a 

brief discussion of the contents of this 

section of the QA Handbook. 

1. Certification and Training of 

Observers The primary purpose of this 

section is to provide a brief summary 

of the certification and training 

procedures described in Reference 1. 

It includes a definition and a brief 

history of opacity, and it discusses 

observer training procedures and 

certification and recertification of 

observers. 

2. Procurement of Apparatus and 

Supplies Section 3.12.2 presents 

specifications criteria and design 

features to aid the procurement of 

useful equipment that would provide 

good quality visible emissions data. 

The following are some recommended 

equipment items not specifically 

required by Method 9: watch, 

compass, range finder, Abney level or 

clinometer, sling psychrometer, 

binoculars, camera, safety equipment, 

clipboard, and accessories. Table 2.1 

summarizes the quality assurance 

aspects of equipment procurement. 

3. Preobservation Operations 

Section 3.12.3 summarizes the 

preobservation activities: gathering 

facility information, providing prior 

notification, establishing protocol, and 

performing equipment checks. Table 

3.1 summarizes these procedures. 

4. On-Site Field Observations 

Section 3.12.4 contains detailed 

procedures for determining the visible 

emissions (VE). This section not only 

includes the recommended 

procedures for performing the 

perimeter survey, plant entry, and VE 

determination; it also contains a 

subsection on special observation 

problems. This subsection explains 

how to take VE readings under less 

than ideal conditions (e.g., when the 

observer position is restricted). The 

main feature of this section is the 

presentation of detailed instructions 

on how to complete the recommended 

VE data form, and examples of 

completed forms. 

5. Postobservation Operations 

Section 3112.5 presents a brief 

discussion concerning the data 

reporting procedures, data summary, 

data validation, and equipment check. 

Section 3.12.6 contains a discussion 

of the calculations required for 

completing the data forms and 

reports. It also includes procedures for 

calculating the path length through 

the plume and for predicting steam 

plume formation by use of a 

psychrometric chart and pertinent 

measurements. 

6. Auditing Procedures Section 

3.12.7 recommends performance and 

system audits for use with field VE 

determinations. The two performance 
April 1983 3 Section 3.12.0 

audits are an audit by senior 

observer/supervisor and a data 

calculation audit, A system audit is 

suggested, along with a Method 9 

checklist, as shown in Figure 7.1. 

Table 7.1 summarizes the quality 

assurance activities for audits. 

7. References and Bibliography 

Sections 3.12.8 and 3.12.9 contain 

the Method 9 and suggested 

references and bibliography. 

8. Data Forms Section 3.12.10 

provides blank data forms which can 

be taken from the QA Handbook for 

field use or serve as the basis of a 

revised form to be used by the 

Agency. Partially completed forms are 

included in the corresponding section 

of the QA Handbook. 
April 1983 1 Section 3.12.1 

1 .O Certification and Training of Observers 

The purpose of this section is to 

summarize the content of the QA 

manual for VE training programs.’ 

Since the observer must be properly 

certified or a qualified VE reader in 

order to have his/her opacity reading 

accepted, it is important that he/she 

fully understand this phase of his/her 

training. 

literal definition of plume opacity is 

the degree to which the transmission 

of light is reduced or the degree to 

which visibility of a background as 

viewed through the diameter of a 

plume is reduced. In terms of physical 

optics, opacity is dependent upon 

transmittance (l/lo) through the 

plume, where I0 is the incident light 

flux and I is the light flux leaving the 

plume along the same light path. 

Percent opacity is defined as follows: 

integral part of the certification 

program. A spring/fall schedule is 

preferable because of weather 

considerations. Certifying previous 

graduates while the smoke school is 

in session is more efficient and less 

costly than scheduling a separate 

session. 

1.2.2 Classroom Training - The 

training is accomplished most 

effectively by holding an intensive lor 2-day classroom lecture/discussion 

session. Although this training is not 

required, it is highly recommended for 

the following reasons: 

1 .l Definition and Brief 

History of Opacity 

The VE evaluation system evolved 

from the concept developed by 

Maximillian Ringelmann in the late 

1800’s, in which a chart with 

calibrated black grids on a white 

background was used to measure 

black smoke emissions from coal-fired 

boilers. The Ringelmann Chart was 

adopted by the U.S. Bureau of Mines 

in the early 1900’s and was used 

extensively in efforts to assess and 

control emissions. In the early 1950’s. 

the Ringelmann concept was 

expanded to other colors of smoke by 

the introduction of the concept of 

“equivalent opacity.” 

The Federal government has 

discontinued the use of Ringelmann 

numbers in EPA Method 9 procedures 

for New Source Performance 

Standards (NSPS). Current procedures 

are based solely on opacity. Although 

some State regulations still specify 

the use of the Ringelmann Chart to 

evaluate black and gray plumes, the 

general trend is toward reading all 

emissions in percent opacity. 

In practice, the evaluation of opacity 

by the human eye is a complex 

phenomenon and is not completely 

understood. However, it is well 

documented that visible emissions 

can be assessed accurately and with 

good reproducibility by properly 

trained/certified observers. 

The relationships between light 

transmittance, plume opacity, 

Ringlemann number, and optical 

density are presented in Table 1 .l A 

Percent opacity = (1 -l/l,) x 100. 

Many factors influence plume 

opacity readings: particle density, 

particle refractive index, particle size 

distribution, particle color, plume 

background, path length, distance and 

relative elevation to stack exit, sun 

angle, and lighting conditions. Particle 

size is particularly significant; 

particles decrease light transmission 

by both scattering and direct 

absorption. Thus, particles with 

diameters approximately equal to the 

wavelength of visible light (0.4 to 0.7 

pm) have the greatest scattering effect 

and cause the highest opacity. 

1.2 Training of Observer 

Field inspectors and observers are 

required to maintain their opacity 

evaluation skills by periodically 

participating in a rigorous VE 

certification program. Accordingly, 

EPA’s Stationary Source Compliance 

Division (SSCD) and Environmental 

Monitoring Systems Laboratory 

(EMSL) have provided the QA training 

document’ to individuals who conduct 

VE training and certification programs. 

This section summarizes the training 

program. 

1.2.1 Frequency of Training Sessions 

- Certification schools should be 

scheduled at least twice per year 

since Method 9 requires a semiannual 

recertification. It is highly 

recommended that training be an 

Tablel.1. Comparison of light, Extinction Terms 

Light Optical density Plume 

transmission, % units opacity, 5% 

0 N/As 700 

20 40 0.704 80 6

60 0.22 40 

80 0.10 20 

100 0.00 0 

“N/A = not applicable. 

Ringelmann 

number 

5 

z 

2 

1 

0 

Increases the VE observer’s 

knowledge and confidence for the 

day-to-day field practice and 

application. 

Reduces training time required 

to achieve certification. 

Trains the smoke reader in the 

proper recording and 

presentation of data that will 

withstand the rigors of litigation 

and strengthens an agency’s 

compliance and enforcement 

program. 

Provides a forum for the periodic 

exchange of technical ideas and 

information. 

Some states require classroom 

training for initial certification only. It 

is recommended, however, that 

observers attend the classroom 

training at 3-year intervals to review 

proper field observation.techniques 

and method changes and to 

participate in the exchange of ideas 

and new information. 

1.2.3 Lecture Material - Example 

lecture material for a thorough 

training program is presented in 

Section 3.1 and Appendix A of 

Reference I. A typical six-lecture 

classroom training program consists 

of the following: 

Lecture 1 -Background, principles, 

and theory of opacity. 

Lecture 2-Sources of VE’s, 

presented by someone 

thoroughly familiar with 

source conditions, 

related particle 

characteristics, and 

opacity reading 

procedures and 

problems. 

Lecture g--Proper procedures for 

conducting field 

observations under a 

variety of conditions. 
Section 3.12.1 2 April 1983 

Lecture 4-influence and impact of 

meteorology on plume 

behavior. 

Lecture 5-Legal aspects of VE and 

opacity measurements. 

Lecture g--Actual 

observation/testing 

procedures. 

1.2.4 Training Equipment - An 

integral part of the training program is 

the design and operation of the smoke 

generator and its associated 

transmissometer, as specified in 

Method 9 (reproduced in Section 

3.12.8). Such a program is essential 

because proper observer certification 

cannot take place without the proper 

equipment. Section 4 of Reference 1 

presents performance specifications 

and operating procedures for smoke 

generators which, if followed under a 

good QA program, will ensure 

nationwide uniformity and consistency 

with Method 9 criteria. 

The design and operation of the 

smoke generator has evolved 

significantly since the mid-1960’s. 

The basic components of the smoke 

generator now include: 

1, Black and white smoke 

generating units, 

2. Fan and stack, 

3. Transmissometer system, and 

4. Control panel and strip chart 

recorder. 

Table 1.2 lists the design and 

performance specifications for the 

smoke generator. It must generate 

smoke with an opacity range of 0 to 

100 percent and be sufficiently 

accurate to allow the operator to 

control and stabilize the opacity of the 

smoke. It is recommended that the 

generator also achieve and hold 

opacities in 5 percent increments at 

+2 percent for a minimum of 5 s. 

White smoke is produced by 

dispensing, at regulated rates, No. 2 

fuel oil into the propane-heated 

vaporization chamber. The opacity 

varies in proportion to the volume of 

fuel oil vaporized and is regulated by 

adjusting the flow of fuel oil. 

Black smoke is produced by the 

incomplete combustion of toluene in 

the double-wall combustion chamber. 

The toluene flowrate is also controlled 

by valves and flowmeters. 

7.2.5 Equipment Calibration 

Procedures - Detailed calibration 

procedures are included in a QA 

procedures manual for VE training 

programs.’ The generator transmissometers must be calibrated every six 

months or after each repair. The 

National Bureau of Standards (NBS) 

traceable standards (optical filters) for 

linearity response are available from 

Quality Assurance Division, 

Environmental Monitoring Systems 

Laboratory, U.S. EPA, Research 

Triangle Park, North Carolina 27711. 

It is strongly recommended that the 

calibration be performed before and 

after each certification course to 

ascertain whether any significant drift 

or deviation has occurred during the 

training period. The “zero and span” 

check must be repeated before and 

after each test run. If the drift exceeds 

1 percent opacity after a typical 30- 

min test run, the instrument must be 

corrected to 0 and 100 percent of 

scale before resuming the testing. 

All of the smoke generator 

performance verification procedures 

(e.g., repair and maintenance work, 

spectral response checks, calibration 

check, and response time checks) 

should be documented in writing and 

dated; a bound logbook is highly 

recommended. These records become 

part of the permanent files on the VE 

training program. 

1.2.6 Setup, Operating, and 

Shutdown Procedures - Detailed 

procedures and a parts list are given 

in Section 4.4 of Reference 1. 

1.2.7 Storage and Maintenance of 

the Smoke Generator - Proper 

storage and maintenance procedures 

are essential for smoke generators to 

increase their useful operating life 

and to provide reliability. 

1.2.8 Common Problems, Hazards, 

and Corrective Actions - The 

generator has hot surfaces that can 

cause serious burns. It is 

Table 1.2. Smoke Generator Design and Performance Specifications 

Parameter Performance 

Light source incandescent lamp operatedat 15% of 

nominal rated voltage 

Photocell spectral response Photopic (daylight spectral response 

of the human eye) 

Angle of view 15O maximum total angle 

Angle of projection 15O maximum total angle 

Calibration error *3% opacity, maximum 

Zero and span drift * 7 % opacity, 30 min 

Response time 5 s, maximum 

recommended that attendees be 

advised to stay away from the 

generator during training and test 

runs. It is also recommended that gas 

and fuel lines be correctly checked for 

leaks prior to each use of the 

generator to prevent fire and explosive 

hazards to the operator and nearby 

attendees. 

Occasional breakdowns or 

malfunctions of the generator usually 

occur at the most inopportune times. 

The problem must be diagnosed and 

repairs made expeditiously to provide 

the proper training and maintain the 

interest of the course attendees. 

Some common malfunctions are listed 

in Section 4 of the QA training 

manual.’ 

1.3 Certification of Observer 

This section summarizes the 

certification part of the training 

program. The first part of the 

certification program is to acclimate 

the smoke readers. The following 

procedure is recommended. Both 

black and white plumes are produced 

at certain levels, and during this 

production, the opacity values are 

announced. After some standards 

exposure, four plumes are presented 

to the trainee for evaluation. The 

correct values of the four plumes are 

announced to provide the trainee with 

immediate feedback. The majority of 

the trainees should be ready to take 

the test after a few sets. Certification 

runs are made in blocks of 50 

readings (25 black smoke and 25 

white smoke). The trainees who 

successfully meet the criteria receive 

a letter of certification and a copy of 

their qualification form. The school 

retains the original of the qualification 

form for a minimum of three years, to 

be available for any legal proceedings 

that might occur. According to Method 

9. certification is valid for a period of 

only six months. Neither certification 

or recertification procedures require 

the observer to attend the lecture 

program; however, it is recommended 

that the observer attend the series 

during initial certificatron and 

thereafter every three years. It is also 

recommended that all persons unable 

to pass after 10 qualification runs, be 

provided additional training before 

allowing qualification runs to be 

made. 

Test forms vary greatly because of 

the specific needs and experiences of 

each agency. Figure 1 .l illustrates 

one suggested form. The form should 

be printed on two-copy paper, the 

original for the official file and the 

carbon copy for the trainee to grade 

after each certification run. The test 
April 1983 3 Section 3.12.1 

Affiliation flArc OF Vf&wLm.m - Name mti RbsC -I Run Number /-a 

e Course location - fiiC~M@!&---_____ Sunglasses -J&L- __ 

Date 4 -I& 82 --___ Sky w Wind 3-SDistance and direction to stack Iso f77 Nu< 

Reading 

number 

1 

2 

3 

4 

5 

6 

; 

9 

10 

11 

12 

13 

14 

75 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

Reading 

number 

8 

9 

10 

11 

0 5 10 15 20 a 

Error 

30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 - 

0 5 10 15 20 25 a 35 40 45 

0 5 10 15 20 25 30 35 40 45 

m 

&ii 555 60 65 70 75 80 85 90 95 100 - 

55 60 65 70 75 80 85 90 95 100 - 

0 5 10 15 25 35 40 45 50 55 60 65 70 75 80 85 90 95 100 - 

0 5 10 15 20 25 35 40 45 50 55 60 65 70 75 80 85 90 95 100 - 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 - 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 - 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 - 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 - 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 __ 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 - 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 - 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 - 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 - 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 

Deviation _ 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

12 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

13 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

14 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

15 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

16 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

17 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

18 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

19 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

20 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

21 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

22 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

23 Q 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

24 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

25 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 

Error 

95 100 - 

95 100 __ 

95 100 __ 

95 100 

95 100 

95 100 

95 100 

95 100 

95 100 

95 100 

95 100 

95 100 

95 100 - 

95 100 __ 

95 100 - 

95 100 - 

95 100 __ 

95 100 - 

95 100 - 

95 100 - 

95 100 __ 

95 100 __ 

95 100 _I 

95 100 - 

95 100 __ 

Deviation 

Figure 1.1. Sample certification test form. 
April 1983 4 Section 3.12.1 

form must be filled in completely. 

Certification requires that both of the 

following criteria be satisfied: 

1. No reading may be in error by 

more than 15 percent opacity. 

2. The average [absolute] error 

must not exceed 7.5 percent for 

either set of 25 white or 25 black 

smoke readings. The certification 

runs may be repeated as often as 

necessary. However, it is recommended that all persons who 

have not passed after ten certification runs be given additional training prior to conducting 

additional certification runs. 

The detailed testing and grading 

procedures required to ensure a valid 

test are outlined in Section 5 of the 

QA training manual.’ The Agency 

should maintain a bound logbook, 

arranged by training session, for at 

least three years, as evidence that the 

observer has been certified as a 

qualified VE evaluator by a recognized 

smoke training and certification group 

Each trainee who successfully meets 

the Method 9 criteria receives a letter 

of certification and a copy of his/her 

qualification form. This letter includes 

the date of expiration. 

1.4 Recertification 

Method 9 requires an individual to 

be recertified every six months. 

1.5 In-the-Field Training 

After the observer’s initial 

certification, it is recommended that a 

senior observer accompany the new 

observer on a field observation trip 

and that both individuals 

simultaneously record (using the 

same time piece) their opacity 

readings as a QA check (see Section 

3.12.7). A comparison of these 

readings will indicate any problems 

the new observer might have in 

conducting observations under field 

conditions. A significant discrepancy 

between the readings of the two 

observers, in individual or average 

values, indicates the need for further 

in-field training and continuance of 

the senior observer (not necessarily 

the same one) QA check. After 

satisfactory checks have been made 

on two consecutive field observations, 

the new observer can confidently 

conduct inspections without a senior 

observer. The suggested standard for 

a satisfactory check for 6-min 

(minimum) of consecutive readings is: 

1. No difference in individual 

readings should exceed 20 

percent. 

2. The difference of the average 

value between observers should 

not exceed 10 percent. 

1.6 Smoke School 

Certification Quality 

Assurance Program 

It is recommended that any 

government agency planning to 

develop a smoke school certification 

program obtain a copy of the 

“Recommended Quality Assurance 

Techniques and Procedures for Visible 

Emission Training Programs.“’ Table 

1.3 contains an activity matrix for 

certification and training of observers. 
Section 3.12.1 5 April 1983 

Table 1.3. Activity Matrix for Certification and Training of Observers 

Frequency and Action if 

Acceptance method of requirements 

Activity limits measurement are not met 

Classroom 

training of 

observer 

Smoke generator 

Setup, operating, 

and shutdown 

procedures 

Storage and 

maintenance 

Transmissometer 

Classroom training Rer Ref. 1 

fsuggested) 

Should be able 

to generate 

smoke with an 

opacity range of 

0 to 100%; hold 

opacities i2% 

for at least 5 s 

Adherence to 

procedures in 

Ref. 1 

As above 

Design and perfor- Specifications in 

mance specifications Table 1.2 

Calibration 

Zero and span 

Certification of 

observer 

Recertification 

In-the-field training 

*3% opacity 

maximum 

Opacity drift 

<I% after a 

typical 30-min 

test run 

No reading must 

be in error by 

more than 15% 

and average 

absolute error 

must not exceed 

7.5% for either 

white or black 

smoke readings 

As above 

No reading in 

error by more 

than 20% difference and 

average absolute 

error should 

not exceed 

7 0% difference 

during the field 

observation 

Initially and 

every 3 years 

Before each 

certification test 

run: use method 

in Ref. 1 

Each test run 

As above 

Upon receipt, 

repair, and at 

6-mo intervals 

use method in 

Ref. 1 

Every 6 mo or 

after repair, 

before and after 

each certification course is 

recommended; 

use method in 

Ref. 1 

As above 

Take smoke 

reading test until 

a successful test 

has been completed 

Every 6 mo take 

a smoke reading 

test until a 

successful test 

has been 

completed 

Checks are made 

on the first two 

field observations subsequent to the 

initial certification; comparison 

is made between 

new certified 

observer and an 

experienced 

Review training 

procedures per 

Ref. 1 

Adjust and make 

repeat check of 

operation 

Review procedures 

As above 

Adjust and 

repeat specification check until 

specifications 

are met 

Adjust and 

recalibrate until 

acceptance 

limits are met 

Instruments 

must be corrected to 0 and 

100% before 

testing is 

resumed 

Retake test until 

successful completion 

As above 

Continue comparisons until 

acceptance 

limits are met 

during two field 

observations 
April 1983 1 Section 3.12.2 

2.0 Procurement of Apparatus and Supplies 

Method 9 does not specifically Table 2.1 at the end of this section magnetic with resolution better than 

require any equipment or supplies. contains a summary of the quality 1 O”. It is suggested that the compass 

Therefore, this entire section includes assurance activities for procurement be jewel-mounted and liquid-filled to 

quality assurance procedures that are and acceptance of apparatus and dampen the needle swing; map 

recommended to assist the observer supplies. reading compasses are excellent for 

in documenting data. Nevertheless, 2.1 Stopwatch this purpose. 

this section provides specifications 

criteria or design features, as 

A watch is used to time the 15 

applicable, to aid in the selection of second intervals between opacity 2.3 Range Finder 

readings. The watch should provide a A range finder is used to measure 

equipment that may be useful in the observer’s distance from the 

collecting VE data. Procedures and continuous display of time to the 

nearest second. emission point and should be capable 

limits for acceptance checks are also 

provided. During the procurement of 2.2 Compass of determining distances to 1000 

meters with an accuracy of It10 

equipment and supplies, it is A compass is useful for determining percent. The accuracy of the range 

suggested that a procurement log the direction of the emission point finder should be checked upon receipt 

(Figure 2.1) be used to record the from the spot where the VE observer and periodically thereafter with 

descriptive title of the equipment, the stands and for determining the wind targets at known distances of 

identification number (if applicable), direction at the source. For accurate approximately 500 meters and 1000 

and results of any acceptance checks. readings, the compass should be meters. 

Item description Quantity 

2 

Purchase 

order 

number 

r 5096 

4 

Vendor 

f7skr 

Scient$+, 

T Date T 

Ordered Received cost 

% 2 9$ 

Disposition 

chedcedt-+ 

b use. 

Comments 

Figure 2.1. Example of a procurement Jog. 
Section 3.12.2 2 April 1983 

2.4 -Abney Level or 

Clineometer 

An Abney level is a device for 

determining the vertical viewing angle. 

For visible emission observation 

purposes, it should measure within 5 

degrees. The accuracy should be 

tested by placing the level flat on a 

table that has been previously leveled 

with a referring level and checking it 

at a 45O angle by placing it on a 45O 

inclined plane constructed with the 

plane as the hypotenuse of a right 

triangle with equal base and height. 

2.5 Sling Psychrometer 

The sling psychrometer is used in 

cases where it is suspected that the 

atmospheric conditions will promote 

the formation of a steam plume (see 

Subsection 6.3). The psychrometer 

should consist of two thermometers, 

accurate to 1 /Z°C, mounted on a 

sturdy assembly whereby the 

thermometers may be swung rapidly 

in the air. One thermometer should be 

fitted with a wettable cotton wick tube 

on the bulb. Thermometer accuracy 

should be checked by placing the 

bulbs in a fresh ice water bath at 0% 

2.6 Binoculars 

It is recommended that the observer 

obtain binoculars preferably with a 

magnification of at least 8 x 50 or 10 

x 50. The binoculars should have 

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 ft; no color rings or bands 

should be evident, only black and 

white. The rectilinear field of view can 

be tested by viewing a brick wall at a 

distance greater than 50 ft. There 

should be no distortion of the brick 

pattern as the field of view is 

changed. The binoculars are helpful 

for identifying stacks, searching the 

area for emissions and aid in 

characterizing behavior and 

composition of plume. 

2.7 Camera and Accessories 

A camera is often used in VE 

observations to document the 

emissions before and after the actual 

opacity determination. A 35-mm 

camera v&th through-the-lens light 

metering is recommended for this 

purpose. Useful accessories include a 

“macro” lens or a 250-mm to 350- 

mm telephoto lens, and a 6-diopter 

closeup lens (for photographing 

logbook and evidence of particulate 

deposition). A photo logbook is 

and the observer should always be 

sure to purchase enough fresh color 

negative film (ASA 100 

recommended) for his/her purposes. 

2.8 Clipboard and 

Accessories 

For documenting the visible 

emission observation, the observer 

should have a 10 in. x 12 in. masonite 

or metal clipboard, several black ballpoint pens (medium point), a large 

rubber band, and a sufficient number 

of visible emission observation forms. 

2.9 Safety Equipment 

The following safety equipment, 

which should be approved by the 

Occupational Safety and Health 

Association (OSHA), is recommended 

for the VE observer: 

0 Hard hat in high-visibility yellow 

or orange 

0 Safety glasses, goggles, or eye 

shields 

0 Ear protectors 

0 Safety shoes (steel-toed for 

general industrial use). 

Specially insulated safety shoes are 

necessary in certain areas, such as 

the top of coke ovens. 

Table 2.1. Activity Matrix for Procurement of Recommended Equipment and 

Supplies 

Equipment Acceptance limits 

Frequency and 

method of 

measurement 

Action if 

requirements 

are not met 

Watch 

Compass 

Range finder 

Abney level 

Sling psychrometer 

Binoculars 

Camera 

Clipboard/ 

accessories/forms 

Safety equipment 

Continuous 

display 

Magnetic with 

1 O0 resolution 

Accuracy of 

k 10% over distances to 1000 m 

Accurate within 

It!? 

Each thermometer accurate 

to 1/2OC (1 OF) 

Magnification of 

Bx50or 70x50, 

color-corrected 

coated lenses 

and a rectilinear 

field of view 

35-mm camera 

with throughthe-lens light 

metering 

10 in. by 12 in. 

clipboard; black 

ball-point pens; 

VE observation 

forms 

Hardhat- yellow 

or orange, safety 

glasses and 

shoes, ear 

Check upon 

receipt 

Check upon 

receipt 

Check upon 

receipt and 

quarterly with 

targets at known 

distances of 

about 500 m and 

1000 m 

Check at O” and 

45O 

Check thermometer accuracy 

with ice water 

bath at O°C 

Check upon 

receipt by viewing selected 

objects 

Check quality of 

photos on 

receipt andafter 

processing film 

Check supplies 

periodically 

Check supply of 

safety equipment periodically 

Return to 

supplier 

Return to 

supplier 

Adjust or 

return to 

supplier 

Same as above 

Repair or return 

to supplier 

Return to 

supplier 

Return to 

supplier for 

repair 

Replenish 

supplies 

Maintain equipment availability 

necessary for proper documentation, protectors 
April 1983 1 Section 3.12.3 

3.0 Preobservation Operations 

The following procedures are not 

required by Method 9 but are 

recommended in order to provide 

more consistent data collection and 

better data documentation and 

verification of representative plume 

viewing conditions. Not all procedures 

are needed for every observation. 

Before making on-site VE 

determinations, the observer should 

gather the necessary facility data, 

provide prior notifications when 

applicable, establish an observation 

protocol, and check for availability of 

supplies and properly maintained 

equipment. Table 3.1 at the end of 

this section summarizes the quality 

assurance activities for preobservation 

operations. 

3.1 Gather Facility 

Information 

The observer should be thoroughly 

familiar with the source facility, 

operation, emissions, and applicable 

regulations. In preparation for the onsite visit, the observer should review 

the Agency’s information (in the official 

source file) on the source in question. 

The observer should: 

1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 

10. 

.- 

11. 

Determine the pertinent people 

to be contacted. 

Become familiar with the 

processes and operations at the 

facility and identify those 

facilities to be observed. 

Review the permit conditions, 

requirements, and recent 

applications. 

Determine applicable emission 

regulations. 

identify all operating air 

pollution control equipment, 

emission points, and types and 

quantities of emissions. 

Review history of previous 

inspections, source test results, 

and complaints. 

Check the file to become 

familiar with (or review) plant 

layout and possible observation 

sites. 

Determine normal production 

and operation rates. 

Identify unique problems and 

conditions that may be 

encountered (e.g., steam 

plume). 

Discuss with attorney if case 

development is expected. 

Obtain a copy of the facility 

map with labeled emission 

points, profile drawings, and 

12. 

13. 

Note: If the observer is not familiar 

photographs, if available. A 

with the type of facility or operation, 

facility map is very helpful 

during inspection and should be 

he/she should consult available 

a required item for every 

Agency source file. The map 

makes it easier for the observer 

reference material and inspection 

to identify point sources and 

manuals on the source category. 

activities, and it may be used to 

mark any emission points that 

have been added or modified. 

If an operating permit exists, 

obtain a copy because it may 

contain the VE limits for each 

point source and any special 

operating requirements. 

Determine the status of the 

source with respect to any 

variance or exemption from the 

Agency’s rules and regulations. 

Observationmaynot berequired if 

the source has a variance or is 

exempt from the regulations. 

Review plant terminology. 

Use references such as facility 

maps and previous inspection 

reports to determine if the 

viewing position is restricted 

because of buildings or natural 

barriers. If the viewing position 

requires observations to be 

taken at a particular time of day 

(morning or evening) because 

of sun angle, consider this 

when planning the inspection, 

Determine the possibility of 

water vapor in the plume 

condensing (see Section 

3.12.6). This determination may 

prevent a wasted trip to the 

facility on days when a 

persistent water droplet plume 

is anticipated because of 

adverse ambient conditions. 

14. 

15. 

16. 

The applicability of Method 9 (and 

hence the method of observation) 

should be determined. If Method 9 is 

not applicable, see Section 3.12.4, 

Special Problems. 

Based on information collected 

under Section 3.1 and any prior 

experience with the source, an 

observation protocol should be 

established. First, the observer 

should determine whether one, two, 

or more observers will be required. 

For example, two observers may be 

required to simultaneously make the 

VE determination and gather other 

on-site data (e.g., take photographs, 

draw a new modified facility map if 

one is not available from the plant or 

gather other needed plant information). 

In certain situations where the VE 

observations must be correlated to 

process operation, the second person 

will closely monitor the process 

activity and record the exact time of 

the operating modes of interest. Only 

one observer will make the VE 

determination unless an observer 

audit is being conducted. In this case, 

the designated observer is the one 

being audited. 

3.2 Prior Notification 

The-usual procedure is to make the 

VE determination without prior 

notification unless the plant must be 

entered first to obtain a good view of 

the emission point of interest. 

However, this procedure is not always 

possible, especially in remote 

locations, when operations are 

intermittent, or when specific 

personnel must be present or 

contacted. Determining VE for 

compliance with State Implementation 

Plan ISlPl or NSPS ooacitv reaulations 

A written checklist regarding an 

expected walk-through of the plant 

including questions to ask plant 

officials may be helpful. 

3.4 Perform Equipment 

Checks for On-Site Use 

Be sure that the necessary 

equipment and supplies are available 

for making the VE determination and 

documenting the results. All 

equipment should be visually checked 

for damage and satisfactory operation 

before each VE determination field 

. . . , . trip. 

requires on-site observations during 

conditions of typical or normal 

maximum operations. If the facility is 

notified of the time of this evaluation, 

some operating conditions may be 

altered. If this situation appears likely, 

it is EPA’s policy not to give prior 

notification. EPA is obligated to notify 

State/local agencies of inspections 

and generally prefers to invite the 

applicable agency to participate. The 

observer should notify the affected 

facility and control agencies as soon 

as practical following any official 

opacity readings. 

3.3 Establish Observation 

Protocol 
Section 3.12.3 2 April 1983 

Table 3.1. Activity Matrix for Preobservation Operations 

Frequency and Action if 

Acceptance method of requirements 

Activity limits measurement are not met 

Gather facility 

information 

Make prior 

notification 

Establish protocol 

Perform equipment 

check 

Obtain necessary facility data, 

Subset 3.7 

Make VE determination without prior notification except as 

stated in Subset 

3.2; EPA should 

notify State/ 

local agencies 

and invite 

participation 

Prepare observation protocol, 

Subsec 3.3 

All equipment/ 

supplies available and in satisfactory workin.q order 

Check for completeness of data 

Check the protocol for notification before 

each on-site visit 

and revise the 

protocol as 

necessary 

Check before 

on-site visit 

Same as above 

Obtain missing 

data before onsite visit, if 

possible 

Make required 

notifications 

Complete or 

prepare protocol 

as required 

Replace or 

adjust 

equipment 
April 1983 1 Section 3.12.4 

4.0 On-Site Field Observations 

This section describes field 

observation procedures, including 

perimeter survey, plant entry, VE 

determination, and special observation 

problems. The latter subsection 

supplements the subsection on VE 

determination by providing some 

information on how to take VE 

readings when unfavorable field 

conditions prevent the use of the 

procedure described in Subsection 4.3 

(e.g., when the emissions are 

intermittent or the observer position is 

restricted). The QA activities are 

summarized in Table 4.2 at the end of 

this section. 

4.1 Perimeter Survey 

Before and after the VE 

determination, it is strongly 

recommended that the observer make 

a perimeter survey of the area 

surrounding (1) the point of 

observation and (2) the emission point 

on which the determination is being 

.crr*. made. Such a survey also may be 

made during the VE determination, if 

warranted. 

A perimeter survey can be useful 

in determining the presence of other 

factors that could affect the opacity 

readings. For example, the 

representativeness of the VE readings 

for a given emission point could be 

questioned unless data is available to 

show that the observer excluded 

emissions related to material 

stockpiling, open burning, and 

ambient condensed water vapor in 

adjoining areas of the plant, It is vital 

that the observer be as aware as 

much as possible of extenuating 

conditions. The perimeter survey is 

made to document these conditions. 

Common sense should be used in 

determining the need and extent of 

the survey; in some cases (e.g., a 

single 350-foot stack) a perimeter 

survey is not vital. 

Perimeter surveys can be made 

from either outside or inside the plant 

property, or both. This decision would 

depend on whether the VE 

observations are made from inside or 

outside of the plant, whether the 

observer actually gains entry to the 

e 

plant premises. and whether the plant 

is sufficiently visible from outside the 

premises to make a reasonable 

survey. It is suggested that during the 

survey the observer should note such 

factors as: 

1. 

2. 

3. 

4. 

5. 

6. 

Other stacks and emission points 

whose visible emissions might 

interfere with opacity readings. 

Fugitive emissions that result 

from product or waste storage 

piles and material handling and 

may interfere with observations. 

Fugitive emissions that result 

from unpaved road travel and 

may interfere with observations. 

Water vapor emissions from 

sludge or cooling ponds. 

Open burning. 

Any unusual activities on or 

around plant premises that could 

result in nonrepresentative 

emissions or interfere with 

opacity readings. 

If deemed useful by the observer, 

photographs may be taken to 

document extenuating conditions (see 

discussion of confidentiality and the 

use of cameras in Subsection 4.2.7). 

4.2 Plant Entry 

The following discussion presents 

the recommended plant entry 

procedures. The VE readings 

themselves should not be affected by 

a change in these procedures. 

However, the usefulness of the 

readings in showing a possible 

violation of the applicable standards 

may be compromised by not following 

agency procedures for entering plants. 

Depending on the location of emission 

points at the plant and the availability 

of observation points in the area 

surrounding a facility, the VE observer 

may not have to gain entry to the 

plant premises prior to making VE 

observations. It may be preferable to 

gain access after taking readings to 

check on plant process control 

equipment operating conditions or to 

complete a perimeter survey. Figure 

4.1 is an example entry checklist that 

can be used to assist the observer in 

organizing the information that could 

be used at the time of plant entry. 

To maintain a good working 

relationship with plant officials and, 

most importantly, to comply with the 

Clean Air Act and avoid any legal 

conflict with trespass laws or the 

company’s right to privacy and due 

process of law under the US. 

Constitution, the observer must follow 

certain procedures in gaining entry to 

the plant’s private premises. In most 

cases, consent to enter (or the 

absence of express denial to enter) is 

granted by the owner or company 

official. Figure 4.1 lists the pertinent 

section of the Clean Air Act on facility 

entry as well as information on 

confidentiality of process information. 

It is recommended that the inspector 

have a copy of this information 

available in case questions are raised 

by source representatives. 

4.2.1 Entry Point - It is 

recommended that the plant premises 

be entered through the main gate or 

through the entrance designated by 

the company officials in response to 

prior notification. The observer’s 

arrival will usually occur during 

normal working hours unless 

conditions contributing to excess 

opacity levels are noted at certain 

times other than normal working 

hours. If only a guard is present at the 

entrance, it is desirable for the 

observer to present the appropriate 

credentials and to suggest that the 

guard’s supervisor be contacted for 

the name of a responsible company 

official. The observer would then ask 

to speak with this official, who may be 

the owner, operator, or agent in 

charge (including the environmental 

engineer). 

4.2.2 Credentials - After 

courteously introducing 

himself/herself to the company 

official, the observer should briefly 

describe the purpose of the visit and 

present the appropriate credentials 

confirming that he/she is a lawful 

representative of the agency. Such 

credentials will naturally differ 

depending upon the agency 

represented, but it is recommended 

that they include at least the 

observer’s photograph, signature, 

physical description (age, height, 

weight. color of hair and eyes), and 

the authority for plant entry. Agencies 

issue credentials in several forms, 

including letters, badges, ID cards, or 

folding wallets. 

4.2.3 Purpose of Visit - When first 

meeting with a company official, the 

observer needs to be prepared to state 

succinctly the purpose of the visit, 

including the reason for the VE 

determination. Space is provided in 

the recommended form (Figure 4.1) to 

specify the exact purpose of the visit, 

and the observer can refer to this 

when talking with the company 

official. 
Section 3.12.4 April 1983 

Source name and address 

D/q - t+MD /=‘oRTLAn/D CW-i- 

;L f4lLES &OF Rt. + ON 

STATE UP /if36 

jQxq /+!!LS, NJ Od% 

Observer JUd f I%. ~~ I m 

Agency u. s. E.f?+f 

fEG(6h) a= 

Date of VE observation 

5/5lb;z 

Previous company contact (if applicableJ 4’EOfqE c. MUPS 

Title OWN&R 

Emission points at which VE observations to be conducted 

01 GIWVDER 3-u5-007-o;L 03 ~?tiL.-f(xED K/LN 3-OS-m7-05 

0.2 DRYce~ ++I Am *;z 3-~5-007-cGz 

Authority for entry (see reverse sideJ 

Plant safety requirements 

ed Hardhat 0 Coveralls 

I24 Safety glasses g Oust mask suggested 

ad Side shields (on glassesJ 0 Respirator(sJ 

Cl Goggles Specify 

Cl Hearing protection r~ac(uF&5 

Specify PI@ 

FLAWWTD -; 

Cl Other 

I$ Safety shoes (steel-toedJ Specify ’ 

0 Insulated shoes 

0 Gloves 

Company official contacted (on this visitJ sTw4L.w 0. @PI/ 

Title 

Figure 4.1. Visible emission observer’s plant entry checklist. 
April 1983 3 Section 3.12.4 

Authority for Plant Entry: Clean Air Act. Section I74 

- 

(a)(2) the Administrator or his authorized representative upon presentation of his credentials - 

(A) shall have a right of entry to, upon or through any premises of such person or in which any records required to be 

maintained under paragraph (1) of this section are located, and 

(8) may at reasonable times have access to, and copy of any records, inspect any monitoring equipment or methods 

required under paragraph (l), and sample any emissions which such person is required to sample under 

paragraph (I). 

(b) (1) Each State may develop and submit to the Administrator a procedure for carrying out this section in such State. If the, 

Administrator finds the State procedure is adequate, he may delegate to such State any authority he has to carry out this 

section. 

(2) Nothing in this subsection shall prohibit the Administrator from carrying out this section in a State. 

(c)Any records, reports or information obtained under subsection (a) shallbe available to the public except that upon a showing 

satisfactory to the Administrator by any person that records, reports, or information, or particular part thereof, (other than 

emission data) to which the Administrator has access under this section if made public would divulge methods or processes 

entitled to protection as trade secrets of such person, the Administrator shaN consider such record, report, or information or 

particular portion thereof confidential in accordance with the purposes of Section 1905 of Title 78 of the United States 

concerned with carrying out this Act or when relevant in any proceeding under this Act.” 

Confidential Information: Clean Air Act, Section 114 (see above) 4 I Federal Register 36902, September 1, 7 976 

If you believe that any of the information required to be submitted pursuant to this request is entitled to be treated as 

confidential. you may assert a claim of business confidentiality, covering all or any part of the information, by placing on (or 

attaching to) the information a cover sheet, stamped or typed legend, or other suitable notice, employing language such as 

‘trade secret, ‘* “proprietary,” or “company confidential. ” Allegedly confidential portions of otherwise nonconfidential 

information should be clearly identified If you desire confidential treatment only until the occurrence of a certain event; the 

notice should so state. Information so covered by a claim will be disclosed by EPA only to the extent, andthrough the procedures, 

set forth at 40 CFR, Part 2, Subpart B (41 Federal Register 36902, September 1, 1976.) 

If no confidentiality claim accompanies this information when it is received by EPA, it may be made available to the public by 

e 

EPA without further notice to you. 

Figure 4.1. Reverse side of form. (Continued) 

The principal purpose for an 

observer’s visit to a plant will probably 

fall into one of three categories: (1) a 

VE determination is being made 

pursuant to a neutral administrative 

scheme* to verify compliance with an 

applicable SIP or NSPS, (2) a VE 

determination is being made because 

some evidence of an opacity violation 

already exists, or (3) an unscheduled 

VE determination has just been made 

from an area off the plant property. 

The statement of purpose should state 

clearly what has prompted the visit. 

At this time, the observer also 

should provide the company official 

with a copy of the opacity readings 

and ask that person to sign an 

acknowledgment of receipt of any VE 

readings made previous to entry. In 

lieu of the above, the agency should 

provide a copy within a reasonable 

time. 

4.2.4 Visitor’s Agreements, Release 

of liability (Waivers) - The observer 

should not sign a visitor’s agreement, 

rcI release of liability (waiver), holdharmless agreement, or any other 

agreement that purports to release 

‘Any routine of selecting sites for observation 

that IS not dlrected toward any company 

the company from tort liability. 

Signing this type of release form may 

waive the rights of the observer and 

his/her employer compensation in 

event of personal injury or damages; 

the precise effect of signing an 

advance release of liability for 

negligence depends upon the laws of 

the state in which it is signed. If the 

plant official denies entry for refusal 

to sign a release form, the observer 

should proceed as described in the 

section on entry refusal. 

4.2.5 Section 114 - Section 114 of 

the Clean Air Act addresses both the 

authority for plant entry and the 

protection of trade secrets and 

confidential information. For the 

observer’s reference, the applicable 

paragraphs are included on the 

reverse side of the entry checklist in 

Figure 4.1. 

4.2.6 Entry Refusal - In the event 

that an observer is refused entry by a 

plant official or that consent is 

withdrawn before the agreed-upon 

activities have been completed, the 

following procedural steps should be 

followed: 

1. Tactfully discuss the reason(s) for 

denial with the plant official; this 

is to insure that the denial 

has not been based on some sort 

of misunderstanding. Discussion 

might lead to resolution of the 

problem and the observer may be 

given consent to enter the 

premises. If resolution is beyond 

his/her authority, the observer 

should withdraw from the 

premises and contact his/her 

supervisor to decide on a 

subsequent course of action. 

Note the facility name and exact 

address, the name and title of 

the plant officials approached, 

the authority of the person 

issuing the denial, the date and 

time of denial, the reason for 

denial, the appearance of the 

facility, and any reasonable 

suspicions as to why entry was 

refused. 

The observer should be very 

careful to avoid any situations 

that might be construed as 

threatening or inflammatory. 

Under no circumstances should 

the potential penalties of entry 

denial be cited. 

All evidence obtained prior to the 

withdrawal of consent is considered 

admissible in court. 
Section 3.12.4 4 April 1983 

When denied access only to certain 

parts of the plant, the observer should 

make note of the area(s) and the 

official’s reason for denial. After 

completing normal activities to the 

extent possible and leaving the 

facility, the observer should contact 

his/her supervisor for further 

instructions. 

4.2.7 Confidentiality of Data - In 

conducting the VE investigation, the 

observer may occasionally obtain 

proprietary or confidential business 

data. It is essential that this 

information be handled properly. 

The subject of confidential business 

information known as “a trade secret” 

is addressed in Section 114 of the 

Clean Air Act (see Subsection 4.2.5) 

and in the Code of Federal 

Regulations (40 CFR 2; 41 Federal 

Register 36902, September 1, 1976, 

as amended). The Code of Federal 

Regulations (40 CFR 2, Subpart B, 

2.203) embodies a notice to be 

included in EPA information requests. 

This notice is paraphrased on the 

reverse side of the entry checklist 

(Figure 4.1) for the observer’s and 

plant official’s reference. The Code of 

Federal Regulations (40 CFR 2, 

Subpart B, 2.211) also includes the 

penalties for wrongful disclosure of 

confidential information by Federal 

employees. in addition to the penalties 

set forth in the United States Code, 

Title 18, Section 1905. Employees of 

other agencies should check with 

agency attorneys to determine their 

exact personal liability. 

From the observer’s standpoint, 

confidential information may be 

defined as information received under 

a request of confidentiality which may 

concern or relate to trade secrets. A 

trade secret is interpreted as an 

unpatented secret, commercially 

valuable plan, appliance, formula, or 

process used in production. This 

information can be in written form, in 

photographs, or in the observer’s 

memory. Emissions data are not 

considered confidential information. 

Also the Agency reserves the right to 

determine if information submitted to 

it under an official request should be 

treated as confidential. 

A good rule of thumb for the 

observer to follow is to collect only 

that process and operational 

information and to take only those 

photographs that are pertinent to the 

purpose of the plant visit. The plant 

official should be advised that he 

must request confidential treatment of 

specific information provided (see 

paragraph on claims of confidentiality 

on reverse side of entry checklist) 

before it will be treated as confidential 

pending legal determination. The plant 

official should inform the observer of 

any sensitive areas of the facility or 

processes where proprietary or trade 

secret information is indicated. 

Photographs are often used to 

document visible emissions 

observations (see Subsection 4.3.4). 

Before taking photographs from inside 

the plant premises, the observer must 

have the consent of the plant official. 

Most of an observer’s photographs 

will be of emission points only; 

presumably, these should not include 

confidential areas of the plant. If any 

opposition is encountered regarding 

the use of a camera on the plant 

premises, the observer should explain 

that the plant official should request 

confidential treatment of any 

photographs taken. The observer 

must properly document each 

photograph and handle those for 

which confidential treatment has been 

requested in the same manner as 

other confidential data. Photographic 

documentation of VE observations 

from an area of public access outside 

of the plant premises does not require 

approval from a plant official, provided 

the documentation is accomplished 

without the use of highly 

sophisticated equipment or 

techniques. For example, use of a 

high-power telephoto lens (over 100 

mm on a 35 mm camera) that yields 

extensive details (e.g., construction 

layout) might be construed as 

surreptitiously taking confidential 

business information. Thus, a good 

rule of thumb is to be sure that any 

pictures taken show only the details 

that could be seen with the naked eye 

from an area accessible to the public. 

When preparing to leave the plant, 

the observer should allow the plant 

official to examine the data collected 

and make claims of confidentiality. All 

potentially confidential information 

should be so marked, and while on 

the road, the observer should keep it 

in a locked briefcase or file container. 

It should be noted that emission data 

are not considered confidential. 

When the observer returns to the 

agency office, the potentially 

confidential information should be 

placed in a secure, lockable file 

cabinet designated especially for that 

purpose. The observer’s agency 

should have an established secure 

filing system and procedures for 

safeguarding confidential documents. 

In all cases, the observer should make 

no disclosure of potentially 

confidential information until a 

company has had full opportunity to 

declare its intentions regarding the 

information and the Agency has ruled 

that the information is not legally 

confidential. 

4.2.8 Determination of Safety 

Requirements - The violation of a 

safety rule does not invalidate VE 

readings; however, the observer 

should always anticipate safety 

requirements by arriving at the plant 

with a hardhat, steel-toed safety 

shoes, safety glasses with side 

shields, and ear protectors. Safety 

equipment also should include any 

other equipment that is specified in 

the agency files and noted on the 

entry checklist form. 

Some companies require unusual 

safety equipment, such as specific 

respirators for a particular kind of 

toxic gas. In many cases, these 

companies will provide the observer 

with the necessary equipment. In any 

event, the observer must be aware of 

and adhere to all safety requirements 

before entering the plant. Information 

on plant alarms and availability of first 

aid and medical help may be needed. 

4.2.9 Observer Behavior - 

Observers must perform their duties 

in a professional, businesslike, and 

responsible manner. They should 

always consider the public relations 

liaison part of their role by seeking to 

develop or improve a good working 

relationship with plant officials 

through use of diplomacy, tact, and if 

necessary, gentle persuasion in all 

dealings with plant personnel. 

Specifically, observers should be 

objective and impartial in conducting 

observations and interviews with 

plant officials. All information 

acquired during a plant visit is 

intended for official use only and 

should never be used for private gain. 

Observers must be careful never to 

speak of any person, agency. or 

facility in any manner that could be 

construed as derogatory. Lastly, 

observers should use discretion when 

asked to give a professional opinion 

on specific products or projects and 

should never make judgments or draw 

conclusions concerning a company’s 

compliance with applicable 

regulations. Upon giving the data to 

the plant the observer can tell the 

source these are the data that were 

obtained and no judgment as to 

compliance can be made until all the 

data and the regulations are closely 

reviewed. 
April 1983 5 Section 3.12.4 

4.3 Visible Emission 

Determination 

This subsection describes the 

preferred approach to VE 

determination. Because practical 

considerations do not always permit 

the observer to follow this procedure, 

however, special observation 

problems are discussed in Subsection 

4.4. 

4.3. I Opacity Readings - The 

observer must be certified in 

accordance with Section 3.12.1, 

Subsection 1.3, and should use the 

following procedure for visually 

determining the opacity of emissions. 

Observer Position 

1. 

2. 

The observer must stand at a 

distance that provides a clear 

view of the emissions with the 

sun oriented in the 140° sector 

to his/her back. If the observer 

faces the emission/viewing point 

and places the point of a pencil 

on the sun location line such 

that the shadow crosses the 

observers position, the sun 

location (pencil) must be within 

the 140° sector of the line. 

During overcast weather 

conditions, the position of the 

sun is less important. 

Consistent with number 1 above, 

when possible, the observer 

should, make observations from 

a position in which the line of 

vision is approximately 

perpendicular to the plume 

direction: when observing 

opacity of emissions from 

rectangular outlets (e.g., roof 

monitors, open baghouses, and 

noncircular stacks), the 

observer’s position should be 

approximately perpendicular to 

the longer axis of the outlet. 

0 3. When multiple stacks are 

involved, the observer’s line of 

sight should not include more 

than one plume at a time, and in 

any case, during observations, 

the observer’s line of sight 

should be perpendicular to the 

longer axis of a set of multiple 

stacks (e.g., stub stacks on 

baghouses). 

4. The observer must stand at a 

distance that provides total 

perspective and a good view. 

5. In order to comply with the sun 

angle requirements (see item 1) 

it is recommended that the 

observer should try to avoid the 

noon hours (11:OO a.m. to 1:00 

p.m.) in the summertime (when 

the sun is almost overhead). This 

is more critical in the southern 

continental United States. The 

preferred reading distance is 

between 3 stack heights and l/4 

mile from the base of the stack. 

6. The reading location should be 

safe for the observer. 

Opacity Observations 

1. 

2. 

3. 

4. 

5. 

6. 

7. 

Opacity observations must be 

made at the point of greatest 

opacity in that portion of the 

plume where condensed water 

vapor is not present. 

The observer must not look 

continuously at the plume (this 

causes eye fatigue), but should 

observe the plume momentarily 

at 15-s intervals. A 15-s beeper 

is recommended to aid in 

performing the VE readings. 

When steam plumes are 

attached, i.e., when condensed 

water vapor is present within the 

plume as it emerges from the 

emission outlet, the opacity must 

be evaluated beyond the point in 

the plume at which condensed 

water vapor is no longer visible. 

The observer must record the 

approximate distance from the 

emission outlet to the point in 

the plume at which the 

observations are made. 

When steam plumes are 

detached, i.e., 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 near the 

outlet, prior to the condensation 

of water vapor and the formation 

of the steam plume, unless the 

opacity is higher after 

dissipation. 

Readings must be made to the 

nearest 5 percent opacity. A 

minimum of 24 observations 

must be recorded. It is advisable 

to read the plume for a 

reasonable period in excess of 

the time stipulated in the 

regulations (i.e., at least 10 

readings more than the minimum 

required). 

A clearly visible background of 

contrasting color is best for 

greatest reading accuracy. 

However, the probability of 

positive error (higher values) is 

greater under these conditions. 

Generally, the apparent plume 

opacity diminishes and tends to 

assume a negative bias as the 

background becomes less 

contrasting. 

It IS recommended the observer 

wear the same corrective lenses 

8 

that were worn for certification. 

If sunglasses were not worn 

during certification, the observer 

should remove them and allow 

time for the eyes to adjust to the 

daylight before making VE 

determinations. It is 

recommended that the observer 

not wear photo compensating 

sunglasses. 

The best viewing spot IS usually 

within one stack diameter above 

the stack exit, where the plume 

is densest and the plume width 

is approximately equal to the 

stack’s diameter. 

4.3.2 Field Data: The “Visible 

Emission Observation Form” - The 

1977 revision of EPA Method 9 

specifies the recording of certain 

information in the field documentation 

of a visible emission observation. The 

required information includes the 

name of the plant, the emission 

location, the type of facility, the 

observer’s name and affiliation, the 

date, the time, the estimated distance 

to the emission location, the 

approximate wind direction, the 

estimated windspeed, a description of 

the sky conditions (presence and color 

of clouds), and the plume background. 

Experience gained from past 

enforcement litigation involving 

opacity readings as primary evidence 

of emission standards violations has 

demonstrated a need for additional 

documentation when making visual 

determinations of plume opacity. The 

Visible Emission Observation Form 

presented in Figure 4.2 is 

recommended. This form was 

developed after reviewing the opacity 

forms used in EPA Regional Offices 

and State and local arr quality control 

agencies. The form includes not only 

the data required by Method 9, but 

also the information necessary for 

maximum legal acceptability. Valid 

data can be collected on any form; 

however, the recommended form may 

enhance observer efficiency and data 

documentation. A detailed description 

of the use of the recommended form 

is given in the following paragraphs. 

The Visible Emission Observation 

Form can be functionally divided into 

11 major sections, as shown in Figure 

4.3. Each section documents one or 

two aspects of the opacity 

determination. The form endeavors to 

cover all the required and 

recommended areas of documentation 

in a typical opacity observation. A 

“comments” section is included for 

notation of any relevant information 

that is not listed on the form.