P.1 

OAR Box 1115 

Prepped by Ryan Dugan 

Document Number: 

9DIV-A-2 

Docket Number: 

A-84-22 

Printed 4/18/2008 10:52:09 AM Sheet 91 of 94 
P.2 

,v 

A-84-22 

IV-A-2 

• — • 1 

COLLABORATIVE STUDY 

OF OPACITY OBSERVATIONS 

AT FIVE-SECOND INTERVALS 

BY CERTIFIED OBSERVERS 

m a i 1 n ^._. 

fjij J..N 3 0 1932 

EPA AIR DOCKET 1 

Prepared by: 

Thomas H. Rose 

Eastern Technical Associates 

2412 Atlantic Avenue 

Raleigh., North Carolina 27604 

Prepared for: 

EPA Project Manager: Kirk Foster 

U.S. Environmental Protection Agency * 

Stationary Source Compliance Division 

Washington, D.C. 

September 1990 
P.3 

BACKGROUND 

Reference Method 9 is the Federally promulgated method for use in 

determining opacity of visible emissions under new source performance 

standards (NSPS). 

Method 9 specifies that opacity observations be taken and recorded at 15-

second intervals; data reduction involves averaging 24 consecutive 

observations yielding 6-minute averages to determine a violation. Method 9 is 

also used for Federally enforceable State regulations that include a 6-minute 

average opacity standard. 

Many State implementaion plans (SIP's) include opacity standards where the 

6-minute average for data reduction is clearly not the intended technique. 

Federally proposed Method F-1 offers several additional techniques for 

reducing the data based on typical SIP regulations. State implementation 

plans regulations where the six-minute average is not used can be grouped into 

the following categories: 

• Time-Exception Regulations: Visible emissions are allowed to exceed 

a given opacity standard only for a limited time period. An example 

regulation: "Visible emissions shall not equal or exceed 20-percent 

opacity except for 5 minutes/hour." 

• Instantaneous-Limitation (Cap) Regulations: These regulations are 

usually written in conjunction with time-exception regulations, and 

prohibit visible emissions above a given opacity at any time. An 

example: "Visible emissions shall not equal or exceed 20-percent 

opacity except for 5 minutes/hour. Visible emissions shall not 

exceed 60-percent opacity at any time." 

OBJECTIVE 

This study involved a field test conducted to determine the ability of 

observers to assign opacity values to a smoke plume at 5-second intervals, 

rather than 15-second intervals as required by Method 9. Being able to read 

plume opacity values at 5-second intervals would be advantageous in at least 

two applications. 

1. Observers could assign a value to a short-term opacity event without 

giving up the advantage of averaging a number of values sometimes 

referred to as "regression towards the mean." Previous research has 

shown that there is no real difference between an average of twelve 

.values and an average of twenty-four values.Re Thus, if there are 
P.4 

no observational difficulties encountered in making 5-second 

readings, both regulatory and industrial observers will be able to 

better determine the average opacity of intermittent sources. 

Shorter averaging times would also be more appropriate for opacity 

determinations applicable in time-exemption or instantaneouslimitation regulations. 

2. Multiple stacks in close proximity could be read more economically by 

observing more than one plume at a time. The observer can read each 

plume every 15 seconds by alternating between the plumes. This has 

been practiced occasionally, but no test data were previously 

available to validate this technique. 

FIELD TEST 

The field test was conducted in Jacksonville, Florida on December 2, 1987, 

by Eastern Technical Associates. Ten runs were conducted. Each of the runs 

consisted of 13 opacity observations taken at 5-second intervals over a 

1-minute period. Observers were given an audible signal to read at each 

5-second interval. Observer results were recorded to the nearest 5-percent 

opacity on standard Method 9 field forms. Opacity values, as recorded by the 

data logger, ranged from 18 to 80 percent and included both black and white 

plumes. Observers were told only the run number and to make observations at 

the audible signal every 5 seconds. They were monitored and not allowed to 

collaborate on observations. Transmissometer data were collected on a 10-inch 

flat bed strip-chart recorder and the values were read to the nearest 

half-percent opacity. 

Equipment 

An Environmental Industry Model 3000-A Smoke Generator was used as a smoke 

plum simulator for all ten of the field test runs. It conformed to all the 

requirements for EPA Method 9 relative to calibration and stability. 

Calibration of the smoke generator was conducted utilizing Natioh Bureau of 

Standards (NBS) Traceable neutral density filters in accordance with Method 9. 

Calibration data were recorded on a 10-inch strip-chart recorder. The smoke 

generator stack-mounted transmissometer was utilized as the reference source 

for plume opacity and, thus, observer data correlation. 

Quality Assurance 

During the field study, the following conditions were met: 
P.5 

• Observers were selected to have a spread of experience levels. 

• Observers were currently certified. 

• Actual opacity was measured by in-stack opacity meters 

(transmissometers) concurrently with the observer opacity 

determinations. 

• The smoke generator transmissometer was calibrated at nominal 

opacities of 20, 50, and 75 percent, in a manner parallel to that 

used when certifying opacity observers. 

• All calibration points were within 2-percent opacity of the NBS 

traceable standards. 

• Opacities were determined at 5-second intervals cued by an audible 

signal. 

• Data were collected in 1-minute sets separated by a several-minute 

break for paper handling. 

Observers 

The eight observers used were recruited from the pool of attendees at the 

Florida Visible Emissions training and certification program. They included 

persons who had just been certified as well as one person whose certificate 

was about to expire. He was not recertified until the next day. The 

observers represented both industry and government and had a wide range of 

experience. 

RESULTS 

Data from the observers and transmissometer showed good correlation which 

indicates that observers can make valid observations at 5-second intervals. 

The results of this field test are almost identical to those of previous 

studies of Method 9 errors where observations were taken at 15-second 

intervals. The average difference of all observations from the 

transmissometer values was -8.8-percent opacity, which shows a fairly high 

negative bias. Summary data are tabulated in Attachment 1. After grouping 

the differences into the right class interval, the number of data sets in each 

class were tabulated, and the percentage of data sets for each difference 

class was calculated. The following is a cumulative distribution of observer 

error. Errors are grouped according to error level from positive error 

greater than 15-percent opacity through less than 0.01 percent opacity, which 
P.6 

included both positive errors less than 0.01 percent opacity and all negative 

errors. 

Opacity Error 

Percent Level 

Number of Sets 

Percents* 

>15 

3 

3.7 

>10 

5 

6.3 

>7.5 

6 

7.5 

>5 

13 

16 

>0 

37 

46.3 

<0.01 

43 

53.8 

From this table the following data statements can be made. 

3.7 percent of the data sets had greater than 15-percent opacity error. 

6.3 percent of the data sets had greater than 10-percent opacity error. 

7.5 percent of the data sets had greater than 7.5-percent opacity error. 

16 percent of the data sets had greater than 5-percent opacity error. 

46.3 percent of the data sets had some positive opacity error. 

This data also shows that most of the averages (53.8 percent) had a negative 

error or bias. These results replicate previous Method 9 field studies. This 

is a strong indication that there is no significant difference between the 

observation of opacity at 5-second intervals and at 15-second intervals. 

Observer Stress 

One concern prior to the study was that observers simply would have 

mechanical difficulty taking readings at 5-second intervals and that the 

constant activity would be tiring. In contrast, observers commented that it 

was less tiring to read every 5 seconds than every 15 seconds for short times 

due to the effect of boredom. It was noted by the observers that they had no 

difficulty in observing plumes, assigning values, and recording data ewery 

5 seconds. Most did, however, indicate that an audible signaling device or a 

clock on the clipboard is necessary to take readings at the shorter interval. 
P.7 

ATTACHMENT 1 

FIELD DATA SUMMARIES 
FIELD STUDY ON READING SMOKE EVERY 5 SECONDS 

FIELD TEST CONDUCTED IN JACKSONVILLE. FLORIDA 

STUDY DESIGNED BY TOM ROSE 

STUDY CONDUCTED BY DAVID SAVAGE; GENERATOR OPERATOR: PAUL MINOR 

Test. 

Master 

Observer 

1 

W^ 3 

3 

4 

iyjl (J) 

<3 

6 

7 

8 

41.5 41.0 40.5 40.0 40.2 39.8 40.5 41.5 41.0 42.0 41.5 41.0 42.0 

Average 

41.0 

IIIlM^ 

50 

45 

40 

35 

40 

50 

30 

45 

50 

50 

40 

30 

40 

50 

30 

45 

45 

55 

45 

35 

40 

55 

25 

50 

45 

60 

45 

25 

40 

50 

30 

45 

40 

60 

45 

30 

40 

45 

35 

45 

40 

60 

45 

20 

40 

45 

35 

45 

40 

65 

45 

25 

35 

45 

35 

45 

40 

65 

45 

35 

35 

45 

35 

50 

45 

65 

45 

30 

40 

40 

35 

50 

45 

70 

45 

30 

40 

40 

40 

50 

40 

70 

45 

35 

40 

35 

40 

50 

40 

70 

40 

30 

45 

35 

45 

50 

45 

70 

40 

35 

45 

35 

45 

45 

Group Average 

43.5 

61.9 

43.5 

30.4 

40.0 

43.8 

35.4 

47.3 

43.2 

Test 2 

Master 

Observer 

1 

2 

3 

4 

5 

6 

7 

8 

79 2 82.0 81.2 82 0 81.8 81 2 80 0 81 8 81 8 82.0 81.5 80 5 82 8 

Average 

81.4 

70 

75 

75 

65 

75 

75 

75 

80 

75 

80 

80 

80 

75 

75 

80 

60 

75 

85 

80 

80 

80 

75 

80 

80 

75 

85 

80 

75 

80 

75 

75 

80 • 

75 

85 

80 

75 

80 

70 

75 

85 

75 

85 

80 

80 

80 

70 

80 

85 

70 

85 

75 

75 

80 

70 

75 

85 

70 

85 

75 

75 

85 

70 

80 

80 

70 

85 

75 

85 

85 

75 

60 

80 

70 

90 

80 

80 

85 

75 

75 

85 

70 

90 

80 

75 

85 

75 

70 

85 

65 

90 

80 

70 

85 

75 

75 

85 

65 

90 

75 

75 

85 

75 

75 

80 

Group Average 

70.8 

85.4 

78.1 

76.2 

81.5 

73.5 

76.5 

82.3 

78.0 
FIELD STUDY ON READING SMOKE EVERY 5 SECONDS 

FIELD TEST CONDUCTED IN JACKSONVILLE. FLORIDA 

STUDY DESIGNED BY TOM ROSE 

STUDY CONDUCTED BY DAVID SAVAGE; GENERATOR OPERATOR: PAUL MINOR 

Test 3 

Master 

Observer 

\->t-^ 

Test 4 

Master 

Observer 

1 

® 

3 

4 

5 

6 

7 

8 

1 

J-

•12, 

J> 

3 

4 

5 

6 

7 

8 

49.0 

50 

60 

40 

35 

40 

35 

50 

40 

19.0 

15 

35 

30 

25 

15 

25 

20 

30 

48.0 48.8 

50 

60 

45 

35 

35 

35 

50 

40 

19.0 

illlllllllll 

15 

35 

35 

30 

15 

25 

20 

30 

55 

60 

45 

35 

35 

35 

45 

50 

19.8 

15 

35 

30 

25 

15 

25 

20 

25 

49.8 

55 

65 

50 

35 

35 

35 

50 

50 

21.0 

10 

40 

30 

20 

15 

25 

15 

25 

50.5 

55 

65 

50 

30 

40 

30 

50 

55 

20.0 

10 

40 

30 

20 

15 

20 

15 

25 

50.8 

60 

70 

50 

35 

40 

30 

55 

55 

20.0 

15 

40 

35 

30 

15 

20 

15 

25 

50.0 

60 

70 

45 

30 

40 

30 

60 

60 

20.0 

10 

40 

35 

25 

15 

20 

15 

30 

50.0 

55 

70 

45 

30 

40 

35 

60 

60 

20.0 

10 

40 

30 

30 

20 

20 

15 

25 

50.0 

55 

70 

45 

30 

40 

40 

65 

60 

19.8 

10 

45 

30 

25 

15 

15 

20 

25 

50.0 

50 

70 

50 

35 

40 

40 

65 

65 

20.0 

10 

45 

30 

20 

20 

15 

20 

30 

49.0 

50 

70 

50 

30 

40 

40 

65 

65 

20.8 

15 

45 

30 

30 

20 

15 

20 

25 

50.2 49.2 

Ililllll'BiPlpp 

45 

70 

45 

35 

40 

40 

60 

60 

45 

70 

50 

35 

40 

45 

65 

60 

Group Average 

20.2 21.0 

15 

45 

30 

25 

20 

15 

20 

25 

15 

50 

30 

35 

20 

20 

20 

30 

Group Average 

Average 

49.6 

jlllljlll 

52.7 

66.9 

46.9 

33.1 

38.8 

36.2 

56.9 

55.4 

48.3 

Average 

20.0 

HHBi 

12.7 

41.2 

31.2 

26.2 

16.9 

20.0 

16.1 

26.9 

24.1 
FIELD STUDY ON READING SMOKE EVERY 5 SECONDS 

FIELD TEST CONDUCTED IN JACKSONVILLE. FLORIDA 

STUDY DESIGNED BY TOM ROSE 

STUDY CONDUCTED BY DAVID SAVAGE: GENERATOR OPERATOR: PAUL MINOR 

I 

Test 5 

Master 

Observer 

1 

ft 

3 

4 

5 

6 

7 

8 

Test 6 

Master 

Observer 

1 

ffi 

3 

4 

5 

/|6I 

7 

8 

57.8 

55 

45 

55 

45 

60 

60 

40 

60 

57.8 

55 

50 

50 

55 

50 

70 

55 

50 

58.2 

s-'-tsM sA$} 

55 

45 

60 

50 

60 

65 

40 

60 

64.2 

v*vjf'V *C*? 

55 

50 

60 

55 

60 

65 

40 

65 

58.0 57.5 

55 

50 

50 

55 

45 

70 

55 

45 

60 

55 

45 

60 

45 

70 

50 

50 

62.0 

55 

55 

55 

50 

60 

70 

45 

65 

55.5 

55 

60 

45 

50 

45 

70 

50 

50 

60.5 

60 

60 

55 

55 

65 

70 

45 

65 

56.5 

55 

60 

45 

50 

50 

70 

55 

50 

57.5 

60 

60 

60 

55 

60 

70 

45 

60 

55 0 

55 

60 

45 

60 

45 

65 

55 

45 

60.5 

60 

65 

60 

55 

60 

70 

50 

65 

56 2 

55 

65 

45 

65 

45 

65 

60 

45 

59.0 

60 

70 

65 

60 

65 

70 

45 

65 

55.5 

60 

65 

45 

65 

45 

65 

60 

50 

58.5 

65 

70 

65 

55 

65 

75 

50 

65 

57.8 

60 

65 

45 

65 

45 

60 

55 

50 

59.2 

65 

70 

65 

50 

65 

75 

50 

65 

58 2 

60 

70 

45 

65 

50 

60 

55 

50 

60.0 

65 

75 

65 

60 

65 

75 

55 

65 

57.0 

, •£ 

60 

70 

45 

65 

50 

60 

50 

50 

59.2 59.5 

. . v<*> 

60 

75 

70 

65 

65 

75 

55 

65 

60 

75 

70 

65 

65 

75 

50 

65 

Group Average 

57.2 57.5 

60 

75 

45 

70 

50 

60 

50 

55 

60 

75 

40 

70 

50 

60 

50 

50 

Group Average 

Average 

59.7 

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59.6 

62.7 

61.9 

55.4 

62.7 

70.4 

46.9 

63.8 

60.4 

Average 

56.9 

a--.** ^ •" J**?"* 

57.7 

63.1 

45.4 

61.2 

47.3 

65.0 

53.8 

49.2 

55.3 
FIELD STUDY ON READING SMOKE EVERY 5 SECONDS 

FIELD TEST CONDUCTED IN JACKSONVILLE. FLORIDA 

STUDY DESIGNED BY TOM ROSE 

STUDY CONDUCTED BY DAVID SAVAGE: GENERATOR OPERATOR: PAUL MINOR 

Test 7 • 

Master 

Observer 

Teste 

Master 

Observer 

1 

2 

3 

4 

5 

6 

7 

8 

1 

2 

3 

4 

5 

6 

7 

8 

18.2 

20 

20 

15 

25 

20 

20 

20 

20 

39 2 

, 

40 

30 

40 

30 

40 

25 

35 

40 

20.8 

W 

20 

20 

15 

25 

20 

20 

20 

25 

39 5 

40 

30 

40 

30 

40 

25 

35 

40 

23.5 

KK • 

20 

25 

20 

25 

20 

20 

20 

25 

39 5 

40 

35 

45 

35 

40 

30 

40 

35 

23.5 

20 

25 

15 

20 

20 

20 

20 

20 

39 0 

' 

40. 

35 

45 

35 

45 

30 

40 

35 

23.5 

v 

25 

25 

15 

20 

20 

15 

15 

20 

405 

40 

40 

45 

40 

45 

30 

45 

40 

20.0 

25 

20 

15 

20 

20 

15 

15 

20 

39 5 

40 

40 

45 

35 

45 

30 

50 

35 

19.0 

20 

20 

15 

15 

20 

15 

20 

20 

408 

40 

45 

45 

40 

45 

30 

50 

40 

19.8 

20 

25 

20 

15 

20 

15 

20 

15 

39 8 

-

45 

45 

45 

45 

45 

30 

50 

35 

20.2 

20 

25 

20 

20 

20 

10 

20 

20 

41.5 

v 

45 

50 

45 

50 

'" 45 

25 

45 

40 

20.0 

25 

25 

20 

15 

20 

10 

20 

15 

40.5 

45 

50 

45 

50 

45 

25 

45 

40 

20.0 

25 

20 

20 

20 

20 

10 

25 

15 

40.0 

50 

50 

40 

45 

45 

25 

45 

35 

20.5 20.0 

Average 

20.7 

<>.^u^ 

20 

20 

20 

20 

20 

10 

25 

15 

20 

20 

15 

20 

20 

10 

25 

15 

Group Average 

400 40.5 

s 

50 

50 

40 

50 

45 

25 

45 

35 

50 

50 

40 

55 

45 

25 

45 

40 

Group Average 

21.5 

22.3 

17.3 

20.0 

20.0 

14.6 

20.4 

18.8 

19.3 

Average 

40.0 

43.5 

42.3 

43.1 

41.5 

43.8 

27.3 

43.8 

37.7 

40.3 
FIELD STUDY ON READING SMOKE EVERY 5 SECONDS 

FIELD TEST CONDUCTED IN JACKSONVILLE. FLORIDA 

STUDY DESIGNED BY TOM ROSE 

STUDY CONDUCTED BY DAVID SAVAGE; GENERATOR OPERATOR: PAUL MINOR 

xi 

Test 9 

Master 

Observer 

Test 10 

Master 

Observer 

1 

2 

3 

4 

5 

6 

7 

e 

1 

2 

3 

4 

5 

6 

7 

6 

8 1 0 

70 

75 

75 

75 

75 

85 

70 

75 

49 8 

, 

40 

35 

35 

50 

40 

50 

55 

35 

8 1 2 

70 

75 

75 

80 

80 

85 

75 

80 

4 8 5 

40 

35 

40 

45 

40 

50 

50 

30 

60 8 

Mr 

75 

75 

75 

85 

80 

60 

75 

80 

4 8 2 

40 

40 

35 

50 

35 

50 

45 

35 

82 0 

75 

60 

80 

80 

85 

80 

60 

80 

4 8 0 

40 

40 

35 

50 

35 

50 

45 

35 

63 0 

75 

80 

60 

60 

85 

85 

80 

60 

49 0 

35 

45 

35 

45 

40 

45 

40 

30 

82 2 

75 

60 

80 

85 

90 

80 

60 

60 

46 5 

35 

45 

35 

45 

40 

45 

45 

30 

82 8 

60 

85 

60 

85 

90 

80 

65 

80 

47 6 

35 

50 

35 

60 

35 

40 

50 

35 

82 0 

60 

85 

75 

85 

90 

80 

75 

65 

50 5 

35 

50 

35 

55 

35 

40 

50 

40 

8 1 5 

80 

85 

75 

75 

90 

80 

75 

85 

56 8 

35 

55 

35 

60 

40 

40 

55 

40 

... 

81 5 

80 

85 

75 

60 

90 

80 

75 

65 

57.8 

35 

60 

35 

65 

40 

40 

55 

40 

80 5 

80 

85 

75 

85 

90 

60 

75 

80 

50 6 

35 

60 

40 

65 

40 

45 

50 

45 

60.8 60 2 

ra- *•'• 

75 

85 

75 

80 

90 

80 

80 

60 

75 

90 

75 

85 

90 

80 

60 

85 

Group Average 

50 5 49 5 

35 

55 

40 

55 

40 

45 

45 

40 

35 

50 

40 

50 

40 

40 

50 

40 

Group Average 

Average 

81.5 

ilslilllBtt 

7 6 2 

81.9 

76.5 

81.5 

86.5 

61.2 

77.3 

81.2 

60.2 

Average 

50.4 

\ '*"*-* * 

36.5 

47.7 

36.5 

53.5 

38.5 

44.6 

48.6 

36.5 

42.6