EPA-450/3-76-002
December 1975
MODEL VALIDATION
AND TIME-CONCENTRATION
ANALYSIS OF THREE
POWER PLANTS
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
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EPA-450/3-76-002
MODEL VALIDATION
AND TIME-CONCENTRATION
ANALYSIS OF THREE
POWER PLANTS
Miehael T. Mills unil Rog«-r Vt Stern
(iCA/Teehnolog) l)i\ i»ion
Burlington Roiid
liedford. MahMiehiiM-U). OI73O
Conlrur No.
Program Element No. 2ACI2')
EPA Projeet Offieer: RiiMsell F. I.ee
Prepared for
ENVIRONMENTAL PROTECTION AGENCY
Offiee of Air and Waste Management
Offiee of Air Quality Planning and Standards
Reneareh Triangle Park, North Carolina 277 I I
• «^=r EiiVixxtfnior.trii Prctactiua Agency
December 1975 - .' „ r -•- .,
txf-1 v L ,.'. , n * i ! ^ v '
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This report is issued by the Environmental Protection Agency to report
technical data of interest to a limited number of readers. Copies are
available free of charge to Federal employees, current contractors and
grantees, and nonprofit organizations - as supplier permit - from the
Air Pollution Technical Information Center, Environmental Protection
Agency, Research Triangle Park, North Carolina 27711; or, for a fee,
from the National Technical Information Service, 5285 Port Royal Road,
Springfield, Virginia 22161.
This report was furnished to the Environmental Protection Agency by
GCA/Technology Division, Bedford, Massachusetts 01730, in fulfillment
of Contract No. 68-02-1376. The contents of this report are reproduced
herein as received from GCA/Technology Division. The opinions, findings,
and conclusions expressed are those of the author and not necessarily
those of the Environmental Protection Agency. Mention of company or
product names is not to be considered as an endorsement by the Environmental
Protection Agency.
Publication No. EPA-450/3-76-002
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ABSTRACT
This report presents an analysis of the EPA Single Source Model using SC«2
concentration and meteorological data collected in the vicinity of three
Ohio Power Plants: J. M. Stuart, Muskingum River, and Philo. The model
predicts the upper percentile of the frequency distribution of 1-hour and
3-hour concentrations reasonably well. Concentrations over the remainder
of the distribution are significantly underpredicted, due in part to the
"">
errors in the determination of background concentrations. The second
'^ highest 24-hour concentrations tend to be underpredicted by the model ex-
'~t>
cept at the Philo plant, where the model is less likely to account proper-
ly for terrain influences. Also investigated during this study were the
vs
frequency distributions of peak 1-hour to average 3-hour and peak 1-hour
to average 24-hour concentration ratios. Statistics of these distributions
were found to vary little from one plant to the next.
ill
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CONTENTS
Abstract lii
List of Figures v
List of Tables xii
Acknowledgments xiii
A
Sections
I Introduction 1
II Data Base Preparation 14
III Data Reduction Methods 19
IV Model Validation Procedure 22
V Analysis of Concentration Ratio Distributions 94
VI Further Analysis of Model Validation Procedures 103
VII References 137
iv
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FIGURES
No. PaSe
1 Map of Ohio and Surrounding States Showing Location of
J. M. Stuart Plant, Philo Plant, and Muskingum River
Plant 3
2 Sketch of the J. M. Stuart Plant Area Showing Locations
of Seven Automatic S0» Monitoring Stations ^
3 Sketch of the Muskingum Plant Area Showing Locations of
Four Automatic SO Monitoring Stations '
4 Sketch of the Philo Plant Area Showing Locations of Six
Automatic S0? Monitoring Stations
5 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour SO Concentrations at Station 1 2^
6 J. M. Stuart Plant Cumulative Frequency Distribution for
3-Hour SO Concentrations at Station 1 2o
7 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour S00 Concentrations at Station 1 2'
8 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour SO Concentrations at Station 2 23
9 J. M. Stuart Plant Cumulative Frequency Distribution for
3-Hour SO Concentrations at Station 2 29
10 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour SO Concentrations at Station 2 30
11 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour SO Concentrations at Station 3 31
12 J. M. Stuart Plant Cumulative Frequency Distribution for
3-Hour SO Concentrations at Station 3 32
13 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour SO Concentrations at Station 3 33
14 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour SO Concentrations at Station 4 3*
15 J. M. Stuart Plant Cumulative Frequency Distribution for
3-Hour S0? Concentrations at Station 4 35
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FIGURES (Continued)
No. Page
16 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour SO Concentrations at Station 4 36
17 J. M. Stuart Plant Cumulative Frequency Pistribution for
1-Hour SO Concentrations at Station 5 37
18 J. M. Stuart Plant Cumulative Frequency Distribution for
3-Hour SO. Concentrations at Station 5 3&
19 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour S02 Concentrations at Station 5 39
20 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour S02 Concentrations at Station 6 40
21 J. M. Stuart Plant Cumulative Frequency Distribution for
3-Hour S02 Concentrations at Station 6 41
22 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour S02 Concentrations at Station 6 42
23 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour S02 Concentrations at Station 7 43
24 J. M. Stuart Plant Cumulative Frequency Distribution for
3-Hour SO Concentrations at Station 7 44
25 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour SO- Concentrations at Station 7 45
26 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour SO Concentrations at All Stations 46
27 J. M. Stuart Plant Cumulative Frequency Distribution for
3-Hour SO Concentrations at All Stations 47
28 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour SO Concentrations at All Stations 48
29 Muskingum River Plant Cumulative Frequency Distribution
for 1-Hour SO Concentrations at Station 1 49
30 Muskingum River Plant CamuiaLiv frequency Distribution
for 3-Hour S0~ Concentrate *s at Station 1 50
31 Muskingum River Plant Cumulative Frequency Distribution
tio
vi
for 24-Hour S02 Concentrations at Station 1 51
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FIGURES (Continued)
No. Page
32 Muskingum River Plant Cumulative Frequency Distribution
for 1-Uour SO Concentrations at Station 2 52
33 Muskingum River Plant Cumulative Frequency Distribution
for 3-Hour SO Concentrations at Station 2 53
34 Muskingum River Plant Cumulative Frequency Distribution
for 24-Hour SO Concentrations at Station 2 54
35 Muskingum River Plant Cumulative Frequency Distribution
for 1-Hour SO. Concentrations at Station 3 55
36 Muskingum River Plant Cumulative Frequency Distribution
for 3-Hour S0~ Concentrations at Station 3 56
37 Muskingum River Plant Cumulative Frequency Distribution
for 24-Hour SO Concentrations at Station 3 57
38 Muskingum River Plant Cumulative Frequency Distribution
for 1-Hour SO Concentrations at Station 4 58
39 Muskingum River Plant Cumulative Frequency Distribution
for 3-Hour S02 Concentrations at Station 4 ' 59
40 Muskingum River Plant Cumulative Frequency Distribution
for 24-Hour SO- Concentrations at Station 4 60
41 Muskingum River Plant Cumulative Frequency Distribution
for 1-Hour SO Concentrations at All Stations 61
42 Muskingum River Plant Cumulative Frequency Distribution
for 3-Hour S02 Concentrations at All Stations 62
43 Muskingum River Plant Cumulative Frequency Distribution
for 24-Hour SO Concentrations at All Stations 63
44 Philo Plant Cumulative Frequency Distribution for 1-Hour
SO. Concentrations at Station 1 6--
45 Philo Plant Cumulative Frequency Distribution for 3-Hour
SO Concentrations at Station 1 65
46 Philo Plant Cumulative Frequency Distribution for 24-Hour
SO- Concentrations at Station 1 66
vil
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FIGURES (Continued)
No.. ZSS
47 ' Philo Plant Cumulative Frequency Distribution for 1-Hour
S02 Concentrations at Station 2 67
48 Philo Plant Cumulative Frequency Distribution for 3-Hour
SO, Concentrations at Station 2
49 Philo Plant Cumulative Frequency Distribution for 24-Hour
SO Concentrations at Station 2
50 Philo Plant Cumulative Frequency Distribution for 1-Hour
S02 Concentrations at Station 3
51 Philo Plant Cumulative Frequency Distribution for 3-Hour
S02 Concentrations at Station 3 71
52 Philo Plant Cumulative Frequency Distribution for 24-Hour
SO, Concentrations at Station 3 72
53 Philo Plant Cumulative Frequency Distribution for 1-Hour
S02 Concentrations at Station 4 73
54 Philo Plant Cumulative Frequency Distribution for 3-Hour
S02 Concentrations at Station 4 74
55 Philo Plant Cumulative Frequency Distribution for 24-Hour
S02 Concentrations at Station 4 75
56 Philo Plant Cumulative Frequency Distribution for 1-Hour
SO Concentrations at Station 5 76
57 Philo Plant Cumulative Frequency Distribution for 3-Hour
S02 Concentrations at Station 5 77
58 Philo Plant Cumulative Frequency Distribution for 24-Hour
S02 Concentrations at Station 5 78
59 Philo Plant Cumulative Frequency Distribution for 1-Hour
SO. Concentrations at Station 6 79
60 Philo Plant Cumulative Frequency Distribution for 3-Hour
S02 Concentrations at Station 6 80
61 Philo Plant Cumulative Frequency Distribution for 24-Hour
S0« Concentrations at Station 6 81
vili
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FIGURES (Continued)
No.
62 Philo Plant Cumulative Frequency Distribution for 1-Hour
SCL Concentrations at All Stations 82
63 Philo Plant Cumulative Frequency Distribution for 3-Hour
SO Concentrations at All Stations 83
64 Philo Plant Cumulative Frequency Distribution for 24-Hour
SO Concentrations at All Stations 84
65 J. M. Stuart Plant Log Probability Plot of Cumulative
Ratio Distributions 95
66 J. M. Stuart Plant Linear Probability Plot of Cumulative
Ratio Distributions 96
67 Muskingum Plant Log Probability Plot of Cumulative Ratio
Distributions 99
68 Muskingum Plant Linear Probability Plot of Cumulative
Ratio Distributions 100
69 Philo Plant Log Probability Plot of Cumulative Ratio
Distributions 101
70 Philo Plant Linear Probability Plot of Cumulative Ratio
Distributions 102
71 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour SO- Concentrations at Station 1 104
72 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour S0_ Concentrations at Station 2 105
73 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour SO Concentrations at Station 3 106
74 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour SO Concentrations at Station 4 107
75 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour S02 Concentrations at Station 5 108
76 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour SO Concentrations at Station 6 109
ix
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FIGURES (Continued)
No. Page
77 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour SO Concentrations at Station 7 110
78 J. M. Stuart Plant Cumulative Frequency Distribution for
SC- Concentrations at All Stations 111
79 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour SO Concentrations at Station 1 112
80 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour SO Concentrations at Station 2 113
81 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour SO Concentrations at Station 3 114
82 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour S02 Concentrations at Station 4 115
83 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour S02 Concentrations at Station 5 116
84 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour SO- Concentrations at Station 6 117
85 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour SO- Concentrations at Station 7 118
86 J. M. Stuart Plant Cumulative Frequency Distribution for
24-Hour SO. Concentrations at All Stations 119
87 Background Cumulative Frequency Distribution for 1-Hour
SO. Concentrations at J. M. Stuart Plant, Muskingum River
Plant and Philo Plant 121
88 J. M. Stuart Plant Cumulative Frequency Distribution for
1-Hour Upwind SO- Concentrations at 7 Stations 122
89 Background Cumulative Frequency Distribution for 1-Hour
SO Concentrations at J. M. Stuart Plant 124
90 Stuart Plant Subtraction Technique #2 Cumul;<•<"" Frequency
Distribution for 1-Hour SO, • Lions at Station 1 125
91 Stuart Plant Snhtractioi .a.ique //2 Cumulative Frequency
Distribution i or x-dour SO Conccntrcitions at Station 2 126
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FIGURES (Continued)
No.
92 Stuart Plant Subtraction Technique #2 Cumulative Frequency
Distribution for 1-Hour SO Concentrations at Station 3 127
93 Stuart Plant Subtraction Technique //2 Cumulative Frequency
Distribution for 1-Hour SO Concentrations at Station 4 128
94 Stuart Plant Subtraction Technique #2 Cumulative Frequency
Distribution for 1-Hour SO Concentrations at Station 5 129
95 Stuart Plant Subtraction Technique #2 Cumulative Frequency
Distribution for 1-Hour SO Concentrations at Station 6 130
96 Stuart Plant Subtraction Technique //2 Cumulative Frequency
Distribution for 1-Hour SO Concentrations at Station 7 131
97 Stuart Plant Subtraction Technique #2 Cumulative Frequency
Distribution for 1-Hour S02 Concentrations at All Stations 132
98 Stuart Plant Subtraction Technique //2 Cumulative Frequency
Distribution for 24-Hour S02 Concentrations at All Stations 134
xi
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TABLES
No. . Page
1 Plant Characteristics 5
2 Sulfur Dioxide Monitor Stations 9
3 J. M. Stuart Plant 1-Hour Concentration Distribution
Statistics for Measurements and Model Validation Run
(Pg/m3) 85
4 J. M. Stuart Plant 3-Hour Concentration Distribution
Statistics for Measurements and Model Validation (pg/m ) 85
5 24-Hour Concentration Distribution Statistics for Meas-
urement and Model Validation Run (pg/m ) 86
6 Muskingum Plant, 1-Hour Concentration Distribution Sta-,
tistics for Measurements and Model Validation Fun (pg/m ) 86
7 Muskingum Plant, 3-Hour Concentration Distribution Sta-
tistics for Measurements and Model Validation Run (ug/m ) 87
8 Muskingum Plant, 24-Hour Concentration Distribution Sta-
tistics for Measurements and Model Validation Run (yg/m^) 87
9 Philo Plant, 1-Hour Concentration Distribution Statistics
for Measurements and Model Validation I\un (pg/mr) 88
10 Philo Plant, 3-Hour Concentration Distrioution Statistics
for Measurements and Model Validation Run (pg/my) BL
11 Philo Plant, 24-Hour Concentration Distribution Statistics
for Measurements and Model Validation Run (pg/m^) 85
12 Ratios of Measured Minus Background to Predicted 1-Hour
Concentrations 90
r ..
13 Correlations 92
14 Statistics for Ratio Distribution 97
15 Concentration Distribution Statistics for Measurements
and Model Validation Run Using Old and New Background
Subtraction Techniques (pg/m^) 133
xii
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ACKNOWLEDGMENTS
The key data used in carrying out this study were made available to
GCA/Technology Division by the Dayton Power and Light Company, the Ohio
Power Company, and the American Electric System. Project direction and
guidance were given by Mr. Russell Lee of the Source-Receptor Analysis
Branch, Monitoring and Data Analysis Division, EPA, Durham, North Carolina,
who served as Project Officer, and by Mr. Michael Lazaro from the EPA
Region V Office.
xiii
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SECTION I
INTRODUCTION
BACKGROUND
Reliable tools for the estimation of SO- concentrations downwind from
large power plants are urgently needed to guide environmental and energy
related policy decisions. Most mathematical dispersion models for the
prediction of S0_ concentrations provide estimates for averaging times
which are either very short (up to 1 hour) or very long (seasonal or
annual). For example, the plume parameters given by Turner and devel-
oped principally from earlier work of Pasquill, Cramer, and Gifford are
based on experimental data much of which was collected over 10- and 30-
minute periods. Power law relationships by which concentrations from
point sources are linked to time are generally considered to be valid only
over averaging times which range from a few minutes to perhaps 1 or 2
hours. National ambient standards for SO., however, include standards
for annual and 24-hour time periods. The method currently favored for
estimating 24-hour concentrations is to average concentrations that have
been predicted for the component 1-hour periods. A second method, based
on the development of peak-to-mean ratio statistics, has been suggested
2
by Montgomery, Carpenter, and Lindley. To date, very few sets of field
data have been used to test the adequacy of either estimation technique.
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PURPOSE OF STUDY
The purpose of this study was twofold;
1. To conduct validation studies of an EPA concentration
model designed to estimate concentrations Jue to a
single source for averaging times of 1 hour, 24 hours
and 1 year, with emphasis on the 24-hour value*
2. To analyze time-concentration relationships of
measured air quality data in the vicinity of a large
elevated point source, paying special attention to
the ratios of 1-hour to 3-hour acid 1-hour to 24-hour
concentrations.
The analytical procedures were to parallel those used by Klug and
2
Montgomery et al. in their analysis of TVA data.
SUITABILITY OF POWER PLANT DATA
J. M. Stuart Site and Plant Description
The J. M. Stuart plant is located in Southwestern Ohio on the Ohio River,
about 9 kilometers Southwest of Manchester, Ohio, and 4 kilometers East ;;
of Maysville, Ohio (see Figures» 1). The plant occupied a position centered
in the Ohio River Valley about 700 meters from the valley walls on either
side. A detailed map.-of the plant, the SO. monitoring sites, and the
surrrounding towns is given in Figure 2. The elevation of the top df thV
valley above the bottom is about 115 meters, so the 244 meter stack* rise
about 130 meters above the surrounding countryside. The data used «ih this
study were collected during the 1-year period from January 1, 1973 to
December 31, 1973. During this period, the plant consisted of four iden-
tical coal-fired boilers with a generating capacity of 610 megawatts each*
However, one boiler was down for repairs during the entire year so that
the total generating capacity was only 1830 megawatts, the yearly average
being 1318 megawatts, or 72 percent of the maximum. Further characteristic*
of this plant can be found in Table 1.
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MICHIGAN
z
o
COAYTON
H
PITTSBURGK
O
COLUMBUS QZANESVILLE
PHILO PLANT
MUSKINGUM
PLANT
,MANCH
•J.M.STUART PLANT
KENTUCKY
WEST VIRGINIA
°
State Capitol
Figure 1. Map of Ohio and surrounding states showing location of
J. M. Stuart Plant, Philo Plant, and Muskingum River
Plant
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Figure 2. Sketch of the J. M. Stuart Plant area showing location*
of seven automatic S02 monitoring stations
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Table 1. PLANT CHARACTERISTICS
Characteristic
Stack height (M)
diameter (M)
velocity (H/S)
temperature (°K)
Number of
boilers per stack
Generating capacity:
Maximum per stack (MW)
Average per stack (MW)
Plant total (MW)
Plant average (MW)
Plant
Stuart
Four
similar
stacks
244
6.0
22.2
373
1 each
610
(each)
439
2440
1318
Muskingum
Stack
1
251
7.6
28.5
430
4
876
748
Stack
2
251
6.7
24.8
425
1
591
487
1467
1235
Philo
Stack
4
81
5.2
4.5
458
2
166
114
Stack
5
81
3.9
7.7
458
2
166
128
Stack
6
84
2.6
29
433
1
125
84
457
326
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Muskingum Site and Plant Description
The Muskingum Plant is located in Southeastern Ohio on the Muskingun
River about 6 kilometers Northwest of the Town of Beverly. Figure 1
shows the geographical location of the Muskingum Plant in relation to
the major cities in Ohio and Figure 3 shows a detailed map of the pl
the SO, monitoring sites, and the surrrounding towns. The plant is sl-
tuated in the Muskingum River Valley and is roughly centered about 500
meters from the valley walls to the north and south. During 1973 !th«
i
plant consisted of five coal-fired units feeding into two stacks. Th*
boiler capacities and stack parameters for its two stacks are listed
in Table 1. Stack 2 is approximately 640 meters to the southwest of
Stack 1. The top of the valley rises about 75 meters above the hotton,
so the 251 meter stacks stand about 185 meters above the surrounding**
Philo Site and Plant Description i
The Philo plant is located in eastern Ohio on the Muskingum River in th*
town of Philo, which is about 11 kilometers to the southeast of
Ohio. The geographical location of the Philo plant in relation to thtt
major cities in Ohio is indicated in Figure 1. Figure 4 shows a
map of the plant, the SO monitoring sites, and the surrounding towns.
The plant Is located in the Muskingum River Valley and is roughly
about 500 meters from the valley walls to the east and west, although that
valley widens to the north. The three stacks are relatively low in com-
parison to the other two plants, since they are approximately 82 meters
high and rise about 11 meters above the top of the valley walls.
Overview of J. M. Stuart Plant Monitoring Program
There are seven sulfur dioxide monitoring stations which comprise th* no-
1
nitoring network. These a e shown on the map in Figure 2 and their
elevations, distances, anJ bearings from the plant are listed in Table 2.
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RT 77
RT78 |0 H I
REIN'ERSVILLE
0
\
RICH VALLEY
CENTERVILLE
HACKNEYtfZ
RT 7«
MUSKINGUM PLANT
STACK I
'ACK 2
N
KILOMETERS
0 I 2 3 4 5
Figure 3. Sketch of the Muskingum Plant area showing locations of
four automatic SC>2 monitoring stations
-------
KU.OWCTCM
? ! ! ? 1
Figure 4. 'sketch of the Philo Plant area showing locations of
six. automatic S02 monitoring stations
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Table 2. SULFUR DIOXIDE MONITOR STATIONS
Plant
Stuart
Muskingum
Philo
Station
No.
1
2«
3
4*
5
6
7C
M
.
1
2
3
4
M
M
-
1
2
3
4
5
6
H
M
H
-
Name
Boone
Brudysville
Bentonville
Manchester
Maysvillc
Rectorville
Sono
Wind instrument
Top of stacks
Beverly
Hackney
Rich Valley
Caldwell
Beverly
Hackney
Top of stacks
Philo
Fox Run
Irish Ridge
Duncan Falls
Salt Creek
Indian Run
Irish Ridge (L)
Irish Ridge (U)
Duncan Falls
Top of stack*
Distance
(km)
2.398
6.550
13.350
8,733
3.830
8.411
5.011
-
-
5.275
4.284
8.264
19.628
5.275
4.284
-
1.710
4.839
4.981
1.319
5.9SS
A. 214
-
-
-
Bearing
(degrees)
34.64
14.95
27.60
48.50
279.11
155.84
220.07
-
-
140.35
39.52
35.35
34.93
140.35
39.52
•>
174.
166.
235.
343.
25.
334.
-
-
•
Elevation above
stack base
(M)
115
85
121
- 7
- 4
115
115
40
244
64
82
101
128
97
104
251
3
2
99
12
26
63
104
140
14
81
'station in operation for about the first quarter of the year only.
Station in operation for about the last three quarters only.
CStat ion in operation for about the first two quarters only.
Mote: M s Meteorological data station.
-------
The monitor at Station 2 was moved to Station A on March 10, 1973, and
the monitor at Station 7 was discontinued on June 17, 1973. Therefore
no data is available at Station 2 for 9 months, Station 4 for 3 months,
and Station 7 for 6 months. The instruments were all Leeds" & Nbrthrup
Company, Catalog No. 7860-SW,* Aeroscan Air Quality Monitors, purchased
in 1968. The sample was obtained by passing ambient air taken from
5 feet above ground level, through an absorption column along with an
absorption solution. The sample analysis.method was by electrolytic
conductivity. Data was taken-continuously and listed every hour.
Electrical calibration tests were performed weekly for zero and half
scale operation. Overall calibration tests were made every six months
at 0.2 ppm using the permeation tube method whose accuracy is traceable
r ^
to the U.S. Bureau of Standards. There^ were some additional hours of
missing data due to loss of electrical power; periods of calibration
and maintenance; and system failures caused by presence of foreign ma-
terial in the sample flow, pump failure, loss of ink supply, failure of
the conductivity cell, etc. : "
,, ' > , ; ; >
The manufacturer's performance accuracy specifications are as follows.
In a typical ambient atmosphere which includes the normal interfering
gasses, this instrument has:
"""- » • *f
• £ero drift * 2 percent pf_r(full scale per week
• Sensitivity drift <'l percent of full scale per week
• Reproducibility < 1 percent of full scale
• Sensitivity * 0.01 ppm
, V. ,
• Recorder error <, 0.5 percent of full scale
• Range a approximately 0-1 ppra
Overview of MusXingu™ Plant .Monitoring Program.. ,, . , "
' ' J* a". *' * •
There are four sulfur dioxide •tflonitt>rin^ stations whfrch comprise the
monitoring network. These are shown on the map in Figure 3 and their
elevations, distances, and bearings from the plant are listed in Table 2.
10
-------
The monitoring station was established in 1969 to monitor the ambient
changes when the new stacks were installed. Data were available from
all stations for January 1 to November 21, 1973. During the entire year
of 1973, Station 1 missed 57 days and the other three stations missed
approximately 41 days. The monitors were the same type used at the
Stuart Plant, with the same calibration procedure, except that they were
automatically zeroed once a day.
Overview of Philo Plant Monitoring Program
There were six automatic S0_ monitoring stations which comprised the mo-
nitoring system in 1974. These are shown on the map in Figure 4 and
their elevations, distances and bearings from the plant are listed in
Table 2. Data was recorded for all of 1974 except the following:
Station Outages
Station 1 First 91 days of year
Station 4 First 91 days of year
Station 6 Second 91 days of year April-July
The monitoring system maintenance and data acquisition were performed by
Environmental Research and Technology in Lexington, Massachusetts.
The instruments were calibrated every 6 months in Lexington and zeroed
every night by computer. These monitors were made by Malloy and have
the following specifications:
Malloy SCL Sensor Specifications
Range 0-1 ppm
Sensitivity 0.005 ppm
Noise + 0.5 percent FS
Response lag < 15 seconds
Rise time to 90 percent < 30 seconds
11
-------
Fall time to 90 percent < 30 seconds
Precision + 1 percent FS
Accuracy + 1 percent FS
Zero drift ± 0.01 ppm/day
+ 0.02 ppm/3 days
Span drift +0.01 ppra/day
+0.02 ppm/3 days
Linearity + 1 percent FS
Fuel Analysis
The following fuel analysis procedures were employed for all three
plants. Each barge of coal from a specific vendor was sampled during
the unloading process. Analysis was performed on all samples. In the
process of determining the caloric value of the coal by bomb calorimeter,
the bomb washings were titrated using tetra-hydroxyquionone to determine
the acid content which indicates the sulfur level. This is known as the
THQ colorimetric method and is a typical loaboratory procedure practiced
by the Dayton Power and Light Company, the Ohio Power Company and the
American Electric Power System. It has been shown to be in excellent
agreement with the standard ASTM method. Average monthly sulfur content
of coal for all of 1973 was tabulated in the FPC-67 report.
On-Site Meteorological Measurements
The only type of on-site meteorological data employed in this modeling
study was the wind direction, which was used to identify upwind stations
for hourly estimates of SO background concentrations. Meteorological
input data for the Single Source Model was obtained from the nearest
surface and upper air weather stations. The on , meteorological instru-
mentation at the J. M. Stuart Plant was a Bendix-Friez wind speed and
direction device, mounted 40 meters above the ground on the coal stacking
tower. Hourly atmospheric stability estimates were determined according
12
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to a "Gustincss Classification" method. These stabilities were not used,
however, in this particular modeling study. There were two wind moni-
toring stations consisting of Bendix-Friez Aerovane wind speed and direc-
tion devices at the Muskingum Plant. One station was located 33 meters
above ground at Beve;. ly, and the other at the Hackney S02 monitoring
station, where the wind monitors were located 22 meters above ground.
The data from Hackney was used in this study, as it .was higher and com-
mon to more stations, but Beverly data was used when the Hackney system
was not recording. There were three meteorological stations at Philo:
1. Irish Ridge Upper - elevation 140 meters above plant base,
(50 meters above ground). This station monitored wind
speed and direction, and temperature difference from the
lower station.
2. Irish Ridge Lower - elevation 104 meters above plant base,
(11 meters above ground). This monitor measured wind speed
and direction, and temperature.
3. Duncan Falls - elevation 14 meters above plant base, (6
meters above ground). Only wind speed and direction were
recorded here.
The •>' -strumentation system components included:
• Climet WD-012-IO Vane and WS-011-1 Anemometer
• Climet 015-2 and 3 Thermister
• Bendix T20-510072-6 3 blade Impeller
The system was maintained by ERT. The first 100 days of meteorological
data were not recorded for 1974. The primary station for wind direction
measurements was Irish Ridge Upper. If this station was not operating,
wind direction data was taken from Irish Ridge Lower or Duncan Falls.
13
-------
SECTION II
DATA BASE PREPARATION
DATA INPUT TO MODEL
Meteorological Data
Hourly surface observations from airport log sheets were keypunched onto
cards. The airports were:
Plant
J. M. Stuart
Muskingum
Philo
Surface observations
airport
Cincinnati, Ohio
Huntington, W. Va. .
Columbus, W. Va.
Year
1973
1973
1974
Mixing heights
Airport
Dayton
Huntington
Dayton
The surface observations included:
• station
• date and time
• ceiling height
• ambient temperature
• wind direction
• wind speed
• percent cloud cover
Daily mixing heights from radiosonde observations were supplied on cards,
A few missing observations were filled in as 500 meters for minimum
mixing heights and 1000 meters for maximum mixing heights.
14
-------
Figure 1 shows the locations of the airports and the plants.
PLANT PARAMETERS
The stack parameters are listed in Table 1 for the three plants. The per-
cent sulfur from the fuel analysis is:
Month
January
February
March
April
May
June
July
August
September
October
November
December
Stuart % S
1.8
1.6
1.8
1.7
1.8
1.6
1.5
1.5
1.5
1.5
1.8
2.1
Muskingum % S
4.9
4.8
4.8
4.5
4.7
5.0
4.7
4.7
4.3
4.6
4.5
4.4
Philo 7. S
3.9
4.8
4.7
4.4
3.3
3.2
2.6
3.2
3.2
2.4
2.6
3.7
These monthly average percent sulfur values were applied to hourly fuel
consumption rates to obtain hourly S02 emissions.
J. M. Stuart Plant
An average annual plant capacity factor of 71.8 percent was found by
averaging the factors given for the three boilers in FPC-67 Schedule B
line 20. This capacity was used to find the average stack exit velocity
and temperature, by interpolating between the 50 percent and 75 percent
load figures given in FPC-67.
15
-------
Fuel consumption was keypunched from copies of the hourly fuel consump-
tion log computer printouts for each of the three boilers. The copies
which were supplied were sometimes illegible and often had data missing
due to computer equipment failure. If an hourly consumption figure was
illegible but the individual loader components of this consumption were
readable, they were added to find the consumption. If the component
loadings were also missing or illegible, the readable hourly consumptions
were subtracted from the daily consumptions, and the remainder was used
to find the missing average consumptions. If the daily consumption was
missing in addition an interpolation between the previous and next read-
able consumption figure was used. There were a few instances, however,
where a good "guess" had to be used. It is felt that any errors thus
encountered have an insignificant effect on the model output, but ques-
tionable cases were logged for future reference.
Muskingum Plant
The average stack exit temperature and velocity for the Munskingum Plant
were supplied by the Ohio Power Company. Hourly values for generated
megawatts were keypunched for each unit from computer log sheets. These
values were then multiplied by an average yearly conversion factor of
pounds of coal per net generated megawatt hour to find the hourly coal
consumption figure. The conversion factors were:
Muskingum Unit 1 0.95 Ib/KWH
Unit 2 0.94 Ib/KWH
Unit 3 0.92 Ib/KWH
Unit 4 0.93 Ib/KWH
Unit 5 0.88 Ib/KWH
The generation data was checked by computer program iur data inconsis-
tencies and also checked against a tape of hourly gross generation data
supplied by the Smith-Singer Company. Several errors were discovered
16
-------
in the generation log sheets and the Smith-Singer tape, and have been
logged for future reference.
Philo Plant
The Philo Plant parameters were supplied by the Ohio Power Company and
are listed in Table 1. Fuel consumption was calculated from 1974 hourly
gross generated megawatt data purchased on tape from Environmental Re-
search and Technology. Ohio Power supplied conversion factors for 1973
hourly net generation data so new factors had to be calculated for 1974
gross generation data.
Philo Unit 4
Unit 5
Unit 6
1973
1.23 Ib/KWH*
1.26 Ib/KWH*
1.11 Ib/KWH*
1974
1.376 Ib/KWH*
1.344 Ib/KWH*
0.983 lb/KWH+
RECEPTOR PARAMETERS
The J. M. Stuart receptor locations were measured from a USGS topogra-
phical map supplied by the Dayton Power and Light Company. The Muskingum
and Philo receptor locations were supplied by the Ohio Power Company. The
spatial parameters for these receptors are listed in Table 2.
MEASURED AMBIENT S02 CONCENTRATIONS
J. M. Stuart Plant
Ambient concentrations were keypunched from supplied copies of the mon-
itoring station network computer printouts. All the data was readable,
1973 conversion factors for net generation data.
1974 conversion factors for gross generation data.
17
-------
and missing data was entered as "999." Wind data was also included on
these printouts. Again, missing data was entered as "999" and wind
direction during calms as "888."
Muskingum and Philo Plants
Ambient concentrations were supplied on tape from the Smith-Singer
Company for the Muskingum Plant, and purchased on tape from Environmental
Research and Technology for the Philo Plant.
18
-------
SECTION III
DATA REDUCTION METHODS
QUALITY CONTROL IN DATA MANAGEMENT
Wiu-r. keypunching and handling large volumes of data, Quality Contr.ro! is
very important. The data supplied in written form was keypunched with
the date and time preceding the measured values. The keypunched cares
-./ere verified by re-keying them on a verifying machine or by reading
both the original and punched numbers. A computer program then decked
lor missing hours, cards out of chronological order, input .';ia outs de
iJints, and extreme changes between consecutive data values. The cards
were stored on tape with each record prefixed by a plant co.le to prevent
the unlikely mixup of plant tapes. All programs which modify the dat.a
have • Jl checking routines to assure that they read the correct data,
and the output from each program was spotchecked by manual calculations.
Previous experience with similar programs and processing have also con-
tributed to the overall Quality Control.
DATA FLOW AND MODIFICATION
3. M. Stuart Plant
Due to the similarity in stack parameters, the hourly fuel consumption of
all three boilers was added together to yield a total hourly consumption.
The monthly sulfur content was then multiplied by this con.-. - ,. .. .TV and a
conversion coefficient to yield the hourly sulfur dioxide emission rate
19
-------
from the plant. These data, along with the Cincinnati meteorological da-
ta, were used in the Single Source Model to predict hourly S02 concen-
trations. Local S0? concentration measurements and on site wind direc-
tion data was used to estimate hourly background concentrations. The
background was assumed to be the average of thos'- concentrations from
stations outside of a 90° sector centered about the wind flow vector, as
measured by the plant wind vane. This average background concentration
was subtracted from the concentration measurements for all stations for
that hour. Any negative concentration values resulting from the back-
ground subtraction were set equal to zero. In the case of missing data
or calms, the last recorded wind direction was assumed to persist until
a station reported a concentration over 0.1 ppm, in which case the wind
was assumed to blow towards that station until a wind direction was re-
corded or another station reported a concentration over 0.1 ppm. The
resultant concentration measurements, corrected for background were then
processed by a cumulative frequency program and plotted by computer.
Muskingum Plant
The source data available for the Muskingum Plant existed in a format
different from that used for Stuart, in that, instead of hourly coal
tonnage figures, only hourly generation figures could be obtained. These
hourly load values were then converted to a fuel consumption rate for
each boiler by means of a set of conversion constants supplied to us by
the utility. Hourly SO emission rates were then obtained from monthly
percent sulfur values. Emission rates for boilers 1-4 were combined
since they feed into a common stack. Boiler 5 was treated as a separate
source. The model application and background subtraction procedures were
identical to those used for the Stuart Plant.
20
-------
Philo Plant
Since all three stacks had different parameters, they were treated as
three separate sources. The hourly generated megawatt data was converted
to an S02 emission rate by the following procedure. A program was written
to total the megawatts per year per unit. The tons coal per year per
unit figure was divided by the total megawatts per year to find an aver-
age conversion coefficient of pounds coal per gross kilowatt. The SO
emission rate was this coefficient multiplied by the hourly megawatts and
the monthly percent sulfur in the coal.
The plant wind direction data for background subtraction was chosen in
the following way. The wind direction was taken from Irish Ridge Upper
since it was the highest station. If that data was not recorded it was
taken from Irish Ridge Lower and if that data was not recorded it was
taken from Duncan Falls. If that data was not recorded it was filled in
as '999.' Since the first 100 days were missing they were ell listed as
'999, ' so that the alternate background subtraction technique, described
during our discussion of the Stuart Plant data reduction, was employed.
21
-------
SECTION IV
MODEL VALIDATION PROCEDURE
MODEL DESCRIPTION
The diffusion model used in this validation study was a gaussian type
model developed by EPA Division of Meteorology. The code (known as
CRSTER) was written to calculate maximum daily concentration of S02 for
a year, meteorological conditions which can lead to these maxima, and
hourly and daily concentrations for an array of receptor locations.
These concentrations are written on tape for the 252 receptor positions
situated at each of 36 directions from the source and seven different
distance ranges (as was the case for the J. M. Stuart Plant). The model
can handle from 1 to 19 sources but treats all of them as if they were
at the same physical location.
Meteorological input to the model consists of hourly surface observations
of wind speed (knots), wind direction sector (1-36), temperature (°F),
total cloud cover (tenths), and twice daily mixing depths (meters).
The format for most of these data is that used by the National Climatic
Center for WBAN-144 hourly surface observations. These data are input
into a preprocessor program which in turn writes a tape containing hourly
values of stability index, mixing height, temperature, windspeed, flow
vector (wind direction plus 180°), and randomized flow vector. The ran-
domized flow vector is equal to the flow vector minus '. uegrees plus a
random number between 0 and 9 degrees. The preprocessor output tape is
then read by the Single Source Model which performs the actual concen-
tration calculations.
22
-------
The preprocessor program generates hourly mixing depths from the twice -
daily mixing depth measurements according to the interpolation scheme
lor rural areas given in the Single Source Model in the Interim User's
4
Guide. Hourly stabilities are determined according to the system given
by Turner employing Pasquill's classification scheme with the addition
of a stability class 7 (i.e., G) for which the assumption is made that
the plume does not reach the ground. Wind speeds u measured at instrument
height h (7 meters is common for weather stations) are adjusted by means
of a stability dependent power law (u = u (h/h ) ) to correspond to values
one would expect at the stack height h. Plume rise is calculated on an
hourly basis using the method of Briggs. If the plume rise calculation
indicates that the plume axis will rise above the mixing layer, then a
zero concentration contribution is specified. If the final height plume
is below the top of the mixing layer, the presence of the top of the
layer is accounted for by the introduction of image plumes to satisfy
the zero flux conditions at ground level and at the top of the mixing
layer.
Source input to the Single Source Model may possess several degrees of
temporal resolution. In the seasonal version of the model an annual
average S00 source strength is specified along with monthly variation
factors. In addition to the seasonal factors, the diurnal version of the
model employs hourly emission variation factors for each month of the
year. A modification made to the model used in our validation study
allowed actual hourly source strengths to be utilized. A second modi-
fication made to the model allowed actual receptor elevations to be
accounted for.
VALIDATION RESULTS
The model results were plotted by computer with the actual measured con-
centrations and background subtracted measured concentrations for 1, 3,
and 24-hour concentrations. The plots are shown for:
23
-------
Stuart Plant in Figures 5 through 28
Muskingum Plant in Figures 29 through 43
Philo Plant in Figures 44 through 64.
The ninety-fifth percentile, ninety-ninth percent lie, second highest, and
highest concentrations were calculated and listed for:
Stuart Plant in Tables 3 through 5
Muskingum Plant in Tables 6 through 8
Philo Plant in Tables 9 through 11.
Average 24-hour concentrations were included in the frequency distribu-
tions only if data for each hour was available. In the calculation of
running three hour average concentrations, those hours with no concentra-
tion measurement were not included in the average, so that for each hour
an average was computed unless data for that hour and the two preceding
hours was missing.
Stuart Plant Validation Results
The most striking feature of the comparison between frequency distribu-
tions of measured and calculated S02 concentrations is the rather poor
agreement for low concentrations. This discrepancy is due primarily to
errors associated with the background subtraction technique which does
not provide for spatial variation in hourly background concentration.
For the high concentration end of the frequency distribution, the model
came much closer to predicting the actual 1-hour concentrations than the
3-hour and 24-hour concentrations. It overpredicted for three stations,
underpredicted for three stations, came very close at one static", and
came very close to predicting the combined data from all stations. Over-
or underpredicting does not seem to be correlated with station elevation
or direction, though there is some correlation with distance as seen in
Table 13. Overpredicted stations are over 5 km from the plant and
24
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
•t *• t» »o to TO to so 40 10 10
J. M. STURRT PLPMT
CUMULflTIVE FREOUENCr
DISTRIBUTION FOR I HOUR
502 CONCENTflflTlONS OT STflTION I
AMEflSUREO MINUS BfiCKCROUNO
j.CflLCULflTEO
o.oi 0.0* OJ «LI o.s i
i a 10 jo jo «o w «o ro »o *o
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 5. J. M. Stuart plant cumulative frequency distribution
for 1-hour S02 concentrations at station 1. Number of
measured concentrations • 8173; number of calculated
concentrations - 8760
-------
0>
CO
to
i/y
K>
OC
cc
UJ
O
O
O
01
CD
03
10
»—i
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
•)•> ?* »s «o ae ro to so 40 so
10 S 2 I O.S 02 O.I 001 O
J. fl. 3TUPPT
CUMULflTIVC FflEQUENCY
OlSTniBUTIQN FCP 3 HOUR
SOe CGNCENTflRTIGNS flT 3TRTIQN 1
QMEP3UPEO '
AnEP3UpEQ MINUS BACKGROUND
4.CRLCU(.RTFO
> * *•
i t
0.01 O.OSOIO2 O.S I I
10
20 10 40 50 60 70 60 SO *S
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
t* tt »»• *9*
Figure 6.
J. M. Stuart plant cumulative frequency distribution
for 3-hour S02 concentrations at station 1. Number of
measured concentrations s 8300; number of calculated
concentrations * 8760
-------
oo-
O
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
SO
•0 TO CO SO «O SO tO
10
i o.» 0.1 o.t
o.oi
I t
J. H. STURRT PLRNT
CUMULflTlVE FREQUEMCT
DISTRIBUTION FOR 2t HOUR
502 CONCEMTRflTIONS flT STflTION 1
O
nEflSURF.0
MINUS BflCKCROUNO
^.COLCULATEO
0.01 0.05 04 OZ 0» t
»*.»
I 9 10 20 30 40 90 »0 70 to »O
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 7. J. M. Stuart plant cumulative frequency distribution
for 24-hour SC>2 concentrations at station 1. Number of
measured concentrations • 288; number of calcula ;ed
concentrations • 365
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
MJ
»» »• IS
»0
•O TO *0 SO «O SO 20
cn-
co-
ID-
10-
00
CO
31
\
O
Z«
O
-------
ro
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
80 TO CO SO 40 JO 20
J. H. 3TUPRT
CUMULATIVE FREQUENCY
DISTRIBUTION FOR 3 HOUfl
502 CONCENTPflTION3 fit 3TBTION Z
QMEP3UPEO
AMEPSUREO MINUS 8BCKG30UNO
..CflLCULRTEO
O.O1 O.OJ 0.» 0-2 0.$ 1 2
10 10 SO «0 50 «0 TO 00 »0 »» »• •» »t • »»» »9.»
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 9. J. M. Stuart plant cumulative frequency distribution
for 3-hour S(>2 concentrations at station 2. Number of
measured concentrations = 1650; number of calculated
concentrations - 8760
-------
cn-
oo-
(D-
ID
tn-
u>
o
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»» «• »s *o *o TO co so 40 so zo to
1 I O.S OJ 0-1 O.OI
aw
J. M. STUflRT PLflMT
CUMULATIVE: FREQUENT
OISTRIBUTIOM FOR I* HOUR
S02 CONCEHTRftTlOMS OT 5TRTIOM 2
OMEOSURED
AMERSUREO MINUS BRCKCROUNO
•!*•
10
ZO 30 10 SO *0 TO »0 »O M •• •*
tt.i Mlt
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
-00
-in
••.I
Figure 10. J. M. Stuart plant cumulative frequency distribution
for 24-hour S02 concentrations at station 2. Number of
measured concentrations = 60; number of calculated
concentrations * 365
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»».! 1* I
•O TO (O SO 40 10 20
10
I O-S 02 O.I
cn-
. co-
in-
CO
O
o:
a:
en
00'
tO
in
LU
O <•">
O
J. M. STUflRT FLflMT
CUMULATIVE FREOUEMCT
DISTRIBUTION FOR 1 HOUR
502 CONCENlTRflTlCWS flT 5TRTION 3
AMEflSUREO MINUS BfiCKCROUNQ
^.CflLCULRT'ID
< I ) I—I—I 1 t-
O.01 0.0* 0.1 OJ 0.9 1 2 5 10 20 90 40 90 $0 70 BO »0 t}
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
*« tt
»! • »»»
•*.*
Figure 11. J. M. Stuart plant cumulative frequency distribution
for 1-hour S02 concentrations at station 3. Number of
measured concentrations = 8444; number of calculated
concentrations = 8760
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
J. M. 3TUPRT PLPNT
CUtlULPTIVE FREQUENCY
DISTRIBUTION FOP 3 HOUR
502 CONCENTPPTION3 flT 3TPTION 3
QMEP3UPEO
AMEP3UPEO MINUS 8PCKCPOUNO
J.CPLCUUPTCD
0.01 OOSOJU 0.» 1
I j 10 20 JO 40 SO *0 70 (0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
*• •»
»»• »9.»
**.*
Figure 12. J. M. Stuart plant cumulative frequency distribution
for 3-hour S02 concentrations at station 3. Number of
measured concentrations « 8561; number ofcalculated
concentrations - 8760
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»».» »*.•
•O TO CO SO 4O JO 20
to
00-
(0
m
J. M. STUflRT PLflMT
CUMULATIVE FREQUENCY
DISTRIBUTION FOR 2t HOUR
302 CONCENTRflTlONS flT STflTION 3
oM£flSURED
AttEflSUREO MINUS BflCKCROUNO
^CALCULATED
I O.S O2 O.I
II II
o.oi
CD
to
in
O.Ot O.OSOJ&Z
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 13. J. M. Stuart plant cumulative frequency distribution
for 24-hour S02 concentrations at station 3. Number of
measured concentrations = 300; number of calculated
concentrations * 365
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
**.» »» •
«o ro co so «o
20
cr>-
oo-
to-
m
(0
O
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
in
J. H. 3TUPRT PLPNT
CUNULPTIVE FREQUENCY
DISTRIBUTION FOP 3 HOUR
508 CGNCENTRHTION3 flT 3TR7ION
At1EP3UPEO MINUS BOCKGROUNO
^.CPLCULflTEO
0.01 0 01 01 OJ 0.9
»9» 59 »
999
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 15. J. M. Stuart plant cumulative frequency distribution
for 3-hour S02 concentrations at station 4. Number of
measured concentrations • 6935; number of calculated
conce.-trations r 8760
-------
o
993 »»-•
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»» »• »» »o ao TO co so 40 10 20 to
i o.* o.z 0.1 0.01
O
10-
1/1-
o
Z)
o
(X
oc
CT>-
OP-
r—-
co-
1/1-
LU
o =»H
2
O 2 concentrations at station 4. Number of
measured concentrations - 250; number of calculated
concentrations - 365
-------
o
o-
{O.
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»».» »» f
»» 9« 9»
60 TO SO SO 4O JO ZO
-------
O
CO
to-
«/•»-
=>•-
n-
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
*• « *0 M 70 CO »0 40 SO 20 IO
2 I O» O-2 OJ O.OI
>.OI O
J. M. 5TUORT PLONT
CUMULflTIVE FREOUENCT
OISTRIBUTIOfJ FOR »* HOUR
502 CONCENTRflTIONS flT STflTICN S
-CO
•10
AH£fl3UREO MINUS BflCKCROUNO
. CflLCULflTEO
-»—t
O.O1 O.OSOJA2 a> 1
»•
99.»
Figure 19.
2 J 10 ZO 30 4O JO «0 70 *0 »O »»
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE .
J. M. Stuart plant cumulative frequency distribution
for 24-hour SC>2 concentrations at station 5. lumber of
measured concentrations s 295; number of calculated
concentrations s 365
-------
00-
r~.
to-
O
ta
in
O.OSOIAI o.» t
»o
a » 10 20 »o 2 concentrations at station 6. Number of
measured concentrations * 8334; number of -calculated
concentrations = 8760
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
"O
**.* »» 9
»» 98 93 »O »0 TO *0 SO 40 SO *O
to
01-
co-
ta
m
O
ID
CJ-
cc
cc.
P--
<£>
IO.
o =«••
•z.
O o
O
J. H. 3TUPRT
CUMULRTIVE FPEOUENCY
DISTRIBUTION FOR 3 HOUR
303 CONCENTRATIONS flT 3TRTION 6
0MEP3UREO
AȣflSUREO MINUS BflCKGROUND
^.CflLCULRTED
-»—*—*-
> i
e.ot o.o» 0.101 o.» i
i » 10 10 10 40 1O (0 TO 8O >0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
»5
ft *»
• *.• 19 •
Figure 21. J. M. Stuart plant cumulative frequency distribution
for 3-hour SC>2 concentrations at station 6. Number of
measured concentrations = 8403; number of calculated
concentrations • 8760
-------
oo-
to-
tn-
CO
z:
to
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
t* »• •»
90 iO TO «0 SO 40 JO ZO 10
I I 0-» at 04 0.01
J. M. STUBRT PLflNT
CUMULflTIVE FREQUENCY
DISTRIBUTION FOR ™ HOUR
502 CONCENTRATIONS flT STftTIOM 6
0ME05UREO
AMEB5UREO MINUS BflCKCROUND
.COLCULflTEO
-co
-r~
-to
-\n
aotaiai o.» t a
20
M *» »»•• ML* **.»
Figure 22.
30 40 SO «O 70 M »0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
J. M. Stuart plant cumulative frequency distribution
for 24-hour S02 concentrations at station 6. Number of
measured concentrations * 300; number of calculated
concentrations * 365
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
O
•».» *» t
•0 70 CO 50 40 SO 10
10
I O.S 0201
O.OI
cn-
oo
cr>-
=r
cn
31
v.
O
t- £
01 "'
01 ^
tU "*
-^- ID
LU
CJ 31
O
o
*—3L.
.). ft. 3TUPRT PLRMT
CUMULflnVE FREQUENC
DISTRIBUTION FOR 1
502 COHCENTflflTIONS
OMEPSUREO
^MEflSURED MINUS BflCKCROUNO
^.CflLCULflTEO
HOUR
T STflTIOW 7
-i—i—»-
i
o.oi 0.010.102 o.s i
«».*
I i 10 2O V) 40 JO 60 70 80 «0 15 *• »»
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 23. J. M. Stuart plant cumulative frequency distribution
for 1-hour S02 concentrations at station 7. Number of
measured concentrations = 3715; number of calculated
concentrations = 8760
-------
99 » '
cr>
CD
P--
(O-
\ri
cn-
O
ID
CC
cc.
UJ
CJ
z:
O
O
CD-
CO
r-
to~
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
I 99 98 95 90
-t 1 4 I 1 1
7O SO SO <0 JO
10
I O.S 0.2 0 1 O 01
J. fl. 3TUPRT PLPNT
CUMULPTIVE FPEQUENCY
01 STP I BUT I Qs- F3P 3 HOUR
CQNCeNTHPTIQNS flT STflTIQN 7
MINUS 8RCKCOOUNO
+ CPL.CU-.OTEO
-4—1—4—»-
0.01 0 OS 04 OJ 0.1 I
Figure 24.
99 • »99
* s jo zo jo «o so «o TO ao so
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
J. M. Stuart plant cumulative frequency distribution
for 3-hour SC>2 concentrations at station 7. Number of
measured concentrations = 3779; number ofcalculated
concentrations « 8760
-------
00-
o
ID
O
Wn
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»9 «( »5 »O *O TO tO SO 40 1O 29
t 0.4 O.2 O.J O.OI
-( 1 t I
J. M. 5TUPRT PLRNT
CUMULATIVE FREQUENCY
DISTRIBUTION FOR 2* HOUR
S02 CONCENTRATIONS flT STflTION 7
CT>
-00
-ID
-IT)
AMEfl5URED MINUS BflCKGROUND
^.CflLCULRTEO
o
ZD
O
20 X) 40 JO tO 70 «0
»0 ti
I* •»
»».• Ml*
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 25. J. M. Stuart plant cumulative frequency distribution
for 24-hour S02 concentrations at station 7. NrT.ber of
measured concentrations = 130; number of calculated
concentrations • 365
-------
CD-
00-
tr>-
cn
o
ID
o
en
oc
er>
05
i—
10-
LU
O
O
ru
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
M.» ** I
I I h
M »5 90 »0 70 CO SO 40 JO 2O
10
J. M. STUflFU PLflMT
CUMULflTIVE FREQUENCY
DISTRIBUTION FOR I HOUR
502 COMCEMTRRTION5 PT flLL STflTIONS
AMER3URED MIMUS BflCKGROUNO.
^.CflLCULflTEO
( -- I
-4 O
AM 04*0404 0-» 1
I 1 10 JO JO «O JO iO 70 BO
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
»0
»»
»(• *».»
**•
Figure 26. J. M. Stuart plant cumulative frequency distribution
for 1-hour S02 concentrations at all stations. Number
of measured concentrations = 45,512; number of cal-
culated concentrations • 61,320
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»».»
9« 93 90 ao 70 60 SO 40 JO 20
IO
CO.
r*.
to
n-
O
ID
O
ee
a:
OD-
eo-
to-
to-
y-
O o-
o
-4 1
J. M. 3TUPPT PLPNT
CUflULflTIVE FREQUENCY
OI5TPI8UTION FOP 3 HOUR
5QZ CaNCENTRRTION3 flT FILL 3TRTION3
AMEP3UPEO MINUS 8PCKGROUNO
4.CPLCULRTEO
0,01 0.0} U OJ 0.4 I
* 3 10 JO JO 40 30 60 70 60 90 »i • 98 91 99 E »».»
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 27. J. M. Stuart plant cumulative frequency distribution
for 3-hour SC>2 concencrations at all stations. Number
of measured concentrations « 46,065; number of cal-
culated concentrations = 61,220
-------
*«
00
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
en
GO
CO
IT)
w.i »» •
—i—i—»-
»3
•O 70 tO tO 40 JO 20
10
1 O.S 0.2 0.1
0.01
o
J. M. STUflRT PLPMT
CUMULflTlVE: FREQUENCr
DISTRIBUTION FOR 2t HOUR
502 CONCENT RflHONS flT ALL STflTIONS
AMEfiSUREQ MINUS BflCKCROUNO
+CfiLCULflTED
~*—'—'—»-
0.01 0,01 OJ(U O.S I I 4 10 20 SO 40 50 *0 70 »0 »0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
-co
-r—
-in
-3-
ro
ts
t* •• It* ML*
**.»
Figure 28. J. M. Stuart plant cumulative frequency distribution
for 24-hour S02 concentrations at all stations.
Number of measured concentrations s 1623; number of
calculated concentrations * 2555
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»t.t
»9 »•
»»
•0 TO tO SO 40 SO
19
CD
CD-
la-
in-
n-
o
>- £~
£'
,_ io-
2 m-
LU
O =
O tn-
i 0.1 0.2 01 ooi O
H ) t 1 1-*""
MU5KINGUM RIVER PLflNT
CUMULflTIVE FREQUENCY
DISTRIBUTION FOR 1 HOUR
508 CONCENTRflTIONS flT STflTlON I
MINUS BflCKGROUND
^.CfiLCULflTED
CD
CO
n—i-
-i
O.Ol 0.0} OJ OJ 0 J I
10
20 JO 4O SO 60 TO 10
»e »»
9S8 99 »
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 29. Muskingura River plant cumulative frequency distribution
for 1-hour S02 concentrations at station 1. Nurrber of
measured concentrations = 7356; number of calculated
concentrations « 8760
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
in
O
RIVER FLRNT
CUhULPTIVE FREQUENCY
DISTRIBUTION FOR 3 HOUR
CONCENTRATIONS f»T 3TRTION I
0MER3UREO
At1EflSUPEO HIWU3 80CKGROUNO
j.CflLCULRTEO
o.oi
*»»
Figure 30.
I » IO 20 JO 40 SO tO TO
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Muskingum River plant cumulative frequency distribution
for 3-hour S(>2 concentrations at station 1. Number of
measured values s 7396; number of calculated values s 8760
-------
O
03-
r- -
43-
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»» •
•O 7O CO
4O M 20
10
-»—I—I
2 I 0.1 0.2 O.I
III II
00!
MU5KINGUM RIVER FLflNT
CUMULflTIVE FREQUENCY
DISTRIBUTION FOR 24 HOUR
502 CONCENTflflTIONS OT STfiTlON 1
oMEflSUREO
AMEflSUREO MINUS BfiCKGROUND
0.01 0.0»OJOI 0.1 I t
It •* »»» »»»
O
en
CO
Figure 31.
S 10 ZO JO 40 50 80 TO 8O
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Muskingum River plant cumulative frequency distribution
for 24-hour S02 concentrations at station 1. Number of
measured values r 297; number of calculated values = 365
-------
N>
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
I1U5KINGUM RIVER PLflNT
CUMULATIVE FREQUENCY
DISTRIBUTION FOR 1 HOUR
502 CONCENTRflTlCNS flT STHTION 2
QMERSUREO
AMEOSUREO MINUS BflCKGROUNO
.CflLCULflTlD
0.01 0.0»
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
fUJSKINGUM PIVEP PLRNT
CUdULPTIVE FREQUENCY
DISTRIBUTION FOP 3 HOUP
302 CQNCENTPRTION3 flT STfiTION 2
ohEP3UPEO
AMEP3UPEO MINUS BflCKGflOUNQ
j-CRLCULRTEO
0.01 0.010.10.2 0.5 I » 9 JO 20 30 4O SO 60 TO BO -»0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE .
Figure 33. Muskingum River plant cumulative frequency distribution
for 3-hour S02 concentrations at station 2. Number of
measured concentrations = 7740; number of calculated
concentrations = 8760
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
op-
r--
to-
* 99. t
t-H 1-
to TO CO >0 40 tO tO
—I 1 1 H—» 1 •—
to
t 0.1 0.2 at 0.01
ti it
MU5KIMGUM RIVER PLfiNT
CUMULflTIVE FREQUENCY
DISTRIBUTION FOR 2U HOUR
502 CONCEMTflflTIONS fiT STfiTlON 2
oMEflSURED
AHEfiSURED MINUS BflCKCROUND
4.CflLCULfiTEO
OAtOJOJ 0.1 I
} » IO 20 SO 40 40 60 70
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE .
CO
r-
co
10
9*9
Figure 34. Muskingum River plant cumulative frequency distribution
for 24-hour S02 concentrations at station 2. Number of
measured concentrations r 319; number of calculated con-
centrations • 365
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
cn-
CD
co-
in-
(M-
21
LU
ru
»» *•
—) t—
•O TO CO 90 4O SO ZO
10
MU5KINGUM R'VER PLflNT
CUMJLflTI/£ FREQUENCT
DISTRIBUTION FOR 1 HOUR
502 CONCENTRflTIONS flT STflTlON 3
QMEfiSURED
AMEflSURED MINUS BflCKGROUND
^.CfiLCULflTEO
O.M 0.05 01 M 0.» I
»3
«t »>
89 » »99
9»*
I 5 JO ZO JO 4O 50 60 7O BO
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 35. Muskingum River plant cumulative frequency distribution
for 1-hour SOo concentrations at station 3. Number of
measured concentrations = 7765; number of calculated
concentrations = 8760
-------
O
T~i
oi-
»».» 99 I
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
98 S3 90 80 TO CO SO 4O SO 20
IO
O
io-
=f-
n-
ra-
cr
a:
01
CO
ta-
UJ
O 31
z
O r»
O
CM
PIVEP PLPNT
CUMULRTIVE FPEQUENCT
DISTRIBUTION OP 3 HQUP
C3NCEMTRRTION3 flT 3TRTIQN 3
.MER3UPEO MINUS 8RCKGBOUNO
^.CPLCULRTEO
•4—1—i-
0.01 0.0*0402 O.S I
t 5 10 20 30 40 50 60 70 60
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
99 • 99*
999
Figure 36. Muskingum River plant cumulative frequency distribution
for 3-hour 802 concentrations at station 3. Number of
measured concentrations = 7772; number of calculated
concentrations = 8760
-------
»».t 99 I
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»i 9J *O SO 70 CO SO 4O SO 10
cr>
-------
CO-
to-
in-
3C
O
z<
o
cc
a:
en
CD
cr»
in
O
Z
O
O
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»» *• »» »0 »O TO «0 SO «O SO *O
to
2 i as o.s o.i o.oi
MU5KJMGUM RIVER PLflNT
CUMULflTIVE FREQUENCY
DISTRIBUTION FOR 1 HOUR
502 COMCENTRflTIONS flT STOTION 4
AMEflSUREQ MIUUS BflCKGROUNO
aoi aotwcu as i > » >o zo w 40 so «o TO so »o »» •• •• »»•• »»» »»»
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 38. Muskingum River plant cumulative frequency distribution
for 1-hour S02 concentrations at station 4. Number of
measured concentrations = 7769; number of calculated
concentrations s 8760
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
flUSKINGUM RIVER PLPNT
CUMULPTIVE FREQUENCY
DISTRIBUTION FOR 3 HOUR
303 CONCENTRATIONS flT 3TRTJON
MINUS BPCKGPOUND
j.CflLCULflTEO
O.01 0-O> 04 03 0.» I X 5 10 20 3O 40 50 (O 70 80 »0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE.
Figure 39. Muskingum River plant cumulative frequency distribution
for 3-hour S02 concentrations at station 4. Nvmber of
measured concentrations = 7775; number of calculated
concentrations * 8760
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
O
»» X— k
O *».» *• • »> »• »5 tO 60 TO CO SO 40 M SO tO 9 * 1 O.S 0.1 0.1 0.01 V-*
, — . . . ..... . i 1 1 1 till 1 *•"
r--
\r>-
rj-
MUSKJNGUM RIVER PLflNT
CUMULRTIVE FREOUEMCY
DI5TRI8UTIOM FOR 24 MGUR
502 CONCENTRflTIONS flT STflTION 4
oM£flSURED
AMEfiSURED MINUS BfiCKGROUMD
+ CflLCULflTED
-co
-r~
-o
-in
-31
-fO
-r\j
CT*
o
o.oi 0.0} o^u a$ >
»J
tt t»
CO
o
I » 10 10 >O 40 iO tO 70 §O *0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 40. Muskingum River plant cumulative frequency distribution
for 24-hour S02 concentrations at station 4. Number of
measured concentrations • 320; number of calculated
concentrations = 365
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
9».t 99 *
99 98
95 90
«O 70 *0 SO 40 iO 20
10
CTi-
OO-
in-
fO
s:
\
o
O
m-
CO-
cc
cc
UJ
O 3"
2
O CO
O
MU5KINGUM RIVER PLfiNT
CUMULHTIVE FREQUENCT
DISTRIBUTION FOR 1 HOUR
502 CQMCEhJTRflTIOMS RT RLL STATIONS
AMEfi5UREO MINUS BflCKGROUND
j.CfiLCULRTEO
-i t
0.01 0.0$ at u as i
99 ««» M9
a » 10 2O 90 40 50 60 70 10
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 41. Muskingum River plant cumulative frequency distribution
for 1-hour S02 concentrations at all stations. Number of
measured concentrations = 30,622; number of calculated
concentrations z 61,320
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
flIVER
CUMULRTIVE FREQUENCY
DISTRIBUTION FQfl 3 HOUR
S02 CGNCENTRBTION3 flT flLL STATIONS
HIKU3 8PCKCPOU»!Q
CPLCULflTEO
O.Ol 0.0»04O2 O.i 1
10
20 30 <0 30 60 TO «0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 42. Muskingum River plant cumulative frequency distribution
for 3-hour S02 concentrations at all stations. Number of
measured concentrations = 30683; number of calculated
concentrations = 35040
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»t.t 9* f
95
60 7O CO 10 4O JO 2O
CT>
CO
to-
ro-
1 0.3 0.2 0.1
->—I—-»—I—
0.01
o
MU5KINGUM RIVER PLflNT
CUMULfiTIVE FREQUENCY
DISTRIBUTION FOR 24 HOUR
502 CONCENTRATIONS HT PLL STflTlONS
^MEfiSUREO
^MEflSUREO MINUS BflCKGROUNQ
.CflLCULOTEO
-03
-CO
-LO
O.OJ O^SOJU 0.} 1
»»
S» *9
9K.3 40»
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 43. Muskingum River plant cumulative frequency distribution
for 24-hour SOo concentrations at all stations. Number of
measured concentrations = 1256; number of calculated
concentrations « 1460
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
PHIIO PLflNT
CUMULflTIVE FREOUEWCY
DISTRIBUTION FOP 1 HOUR
502 COfJCEWTRflTICWS flT STflTION I
oMEflSUREO
AMEflSUREO MINUS 8RCKGROUMO
4.CfllCULflTEO
AM AMO104
Figure 44.
I 9 10 20 »0 40 90 tO 70
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Philo plant cumulative frequency distribution for
1-hour S02 concentrations at station 1. Number of
measured concentrations = 4905; number of calculated
concentrations • 8760
-------
V/t
OD-
•
z
O tn
O
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
99.9 fi 8
99 98 »»
80 TO CO »O 40 SO 20
to
fhlLO
CUMULPTIVE FPEQUENCY
DISTRIBUTION FOR 3 HOUR
502 CQNCENTPflTIQN3 RT 3TRTION 1
ttEP3UREO MINUS BACKGROUND
0.01 0.01O1OJ O.) t
I » JO ZO JO *O iO 60 TO 60
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
9»
>».6 99.9
S9.S
Figure 45. Philo plant cumulative frequency distribution for
3-hour S02 concentrations at station 1. Number of
measured concentrations = 4974; number of calculated
concentrations « 8760
-------
cn
oo
co-
in-
CO _
-------
'o
919 99*
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
99 98 »S 90 80 70 60 SO «0 JO ZO
CD-
CO-
r--
to-
in-
o
CJ-
• (M
; o
_
O.OJ 0-0*0.10-2 0.» 1 t
10
20 JO 40
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE .
Figure 47. Philo plant cumulative frequency distribution for
1-hour S02 concentrations at station 2. Number of
measured concentrations r 7365; number of calculated
concentrations « 8760
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
9» e
CO-
r--
co-
to-
3--
n-
00
CC
oc
01
eo
t£>
to
O =»••
O <-»•
O
99 98
> t
• 9
•O 7O CO JO 4O JO
I I I I 1 1
20
-»—
IO
-+-
O.J 02 0.1
THRO
CUMULPTIVE FREQUENCY
OI3TPIBUTION FOP 3 HOUfl
502 CONCENTRATIONS PT 3TPTIQN 2
MINUS BRCKCROUND
o.oso.iaa
I S IO 20 50 40 SO 60 TO BO »0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
»S
81 •*
*»• »9»
Figure 48. Philo plant cumulative frequency distribution for
3-hour S02 concentrations at station 2. Number of
measured concentrations = 7584; number of calculated
concentrations « 8760
-------
o
CJ
IO
r>
0.01
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
PHILO PLflWT
CUMULPTIVF. FRF.QUF.NCT
DISTRIBUTION FOR 24 HOUR
502 COMCEMTflflTlQNS RT STflTIOuJ 2
QMEflSURF.0
A«EflSUfl£D MINUS 80CKCROUND
*•• ' * » 10 10 JO 40 50 60 70 60 >0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 49. Philo plant cumulative frequency distribution for
24-hour S02 concentrations at station 2. Number of
measured concentrations = 216; number of calculated
concentrations = 365
»*.»
-------
"o
cn-
co-
03-
in-
O
ID
cc
CTi
CO
UJ
O
en
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
9* »J
70
PHILO
CUfiULOTIVE FREQUEMCY
OISTRIBL'TIQW FC5R 1 HOUR
502 CQNCEMTRflTIQNS flT
AM£flSUREQ MIMU5 8RCKGROUND
-(—i-
o.oi to) oa at as i
-H
30
S 5 10 tO SO 40 40 60 TO 80
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
»o
»« t9
9*.*
1.0. O
»».*
Figure 50. Philo plant cumulative frequency distribution for
1-hour S02 concentrations at station 3. Number of
measured concentrations - 7954; number of calculated
concentrations » 8760
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
60 TO 60 50 40 JO 20
PLPNT
CUMULPTIVE FREQUENCY
DISTRIBUTION FOP 3 HOUR
503 CGNCENTRPTION3 flT STflTION 3
QMEP3UREO
Ah£R3UR£0 MINUS BPCKGP8UND
4.CPLCULOTEO
O.Ol O0» 0.102 0.» I t S JO ZO JO 40 iO SO TO 80 SO SJ S» »» 99 * 99.9
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 51. Philo plant cumulative frequency distribution for
3-hour S02 concentrations at station 3. Number of
measured concentrations = 8053; number of calculated
concentrations = 8760
-------
ov
co-
(£>•
to-
cn-
fs>
O
cc
cc
o
ov
CQ
r~
<£)
U)
Z
O
O
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»» 98 »5 to tO 7O (0 SO 40 JO 20 IO
*J__^
5 2 I O.» O.t O.I 0.01 O
PHILO PLRNT
CUMOLPTIVE FREQUEMCT
OI5TRIBUTIOM FOR 21 HOUR
502 CQUCEMTRflTI^MS HT 3TRTION 3
BflCKGROUND
AMEflSUREO
. CflLCULPTEO
t i
o.oi aos ixi O4i o.s i *
S».» W-t
*»»
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 52. Philo plant cumulative frequency distribution for
24-hour S02 concentrations at station 3. Number of
measured concentrations * 289; number of Calculated
concentrations « 365
-------
CD
CO
to
in
o
ID
O
CTJ
CO
r-
CD
O zr
Z
O
o
99.9 »» i
^—t-
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
99 9« 95 »0 »0 TO 60 5O 40 10 tO 1O
2 « O.i O 2 0 « 00)
PHILO PLfiMT
DISTRIBUTION! FOR 1 HOUR
502 COMCEMTRRTnNS flT STflTIOM
QMEflSUREO
AMErtSUREO MINUS BflCKGROUNO
9C »*
9».t »*»
*».*
0.01 0.05 WW 0.8 I 1 5 .0 20 JO 40 50 60 TO 30 90 95
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 53. Philo plant cumulative frequency distribution for
1-hour SC»2 concentrations at station 4. Number of
measured concentrations = 6156; number of calculated
concentrations - 8760
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
tt.t ?i a
98 99 90
SO
CO 50 40 30 ZO 10
10.) 0701 00!
CD-
CO-
r--
ID-
to-J
n-
O
ID
O
cr
a:
OS-
CD-
fHll-0 FLHNT
CUMULflTIVE FPEGUENCY
OI5TPIBUTION FQO 3 HOUR
302 CONCENTRftTI3N3 flT 3TflTIQN
AMER3UREO MINUS BflCKGROUNO
0.01 0.03 OJ O2 Q.»
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 54. Philo plant cumulative frequency distribution for
3-hour S02 concentrations at station 4. Number of
measured concentrations s 6210; number of calculated
concentrations = 8760
-------
0>-
oo-
r~-
CD-
in-
:»•-
*9.a
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
*• tS «0 iO 70 CO 50 40 10 XO
to
—»—
I 0.9 0.2 0.1
0.01
PHILO. PLflMT
CUMULATIVE FREQUENCY
DISTRIBUTION FOR 24 HOUR
502 COMCEMTRfiTIONS flT 3TOTION
oMEflSUREO
^MEflSUREO MINUS BflCKGROUNO
,CPLCULflTEO
cn
00
r-
CO
2:
\
O
0.01
»3 »»
Figure 55.
lit » 10 zo so 40 so 60 70 ao to
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE .
Philo plant cumulative frequency distribution for
24-hour S02 concentrations at station 4. Nu-rfcer of
measured concentrations = 231; number of calculated
concentrations = 365
91*
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»».» 99 i
»J
ov
eo-
r--
CO
o
fM-
f- «
^ r
CC r
t-
05 » 99*
Figure 56. Philo plant cumulative frequency distribution for
1-hour SC>2 concentrations at station 5. Number of
measured concentrations = 7209; number of calculated
concentrations = 8760
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
PLPNT
CUMULPTIVE FREQUENCY
DISTRIBUTION FOR 3 HOUR
303 CONCENTRPTION3 PT 3TPTION S
QMEP3UOEO
Af1Efi3UflEQ MINUS BflCKGROUNO
j.CflLCULftTEO
0.01 Ml M Oi 0.» I
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 57. Philo plant cumulative frequency distribution for
3-hour SC>2 concentrations at station 5. Number of
measured concentrations = 7452; number of calculated
concentrations « 8760
-------
oo
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»».t >9 I
99 *•
9O
so TO eo so 40 10 20
I O.S 0.2 0.1
05-
OD-
03-
PHILO
CUMULHTIVE FREQUENCY
DISTRIBUTION FOR 24 HOUR
COMCEWTRflTIOrlS ^ STflTION S
MINUS BACKGROUND
CflLCULfiTCD
0.01 O.OJOJOJ P.» I t » »0 ZO »0 40 50 60 70 »O »0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 58. Philo plant cumulative frequency distribution for
24-hour S02 concentrations at station 5. Number of
measured concentrations = 219; number of calculated
concentrations = 365
-------
»».» 9* I
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
99 91 »i 90 SO TO SO SO 4O SO 20
O
CD-
CO-
to-
ur
=r-
en
r\j-
•b
05
CO
I-
co
in
O
O
THILO PLfiMT
CUMULATIVE: FREQUENCY
OI5TRI8UTI0^4 FOR 1 HOUR
502 COt'JCEMTRflTia.N.S flT STflTlOM 6
oMEflSUREO
AMEflSUREO MIMU5 BflCKGROUKiO
.CRLCULRTtO
-t—i—•-
o.ot 0.0101 cu o.» t
30 40 50 «0 70 6O
90 95
99i S59
I 5 10
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 59. Philo plant cumulative frequency distribution for
1-hour S02 concentrations at station 6. Number of
measured concentrations = 4882; number of ca .culated
concentrations = 8760
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
**.* »9 a
93 98 »3 90 60 TO SO 50 40 10 ZO 10
oo
o
PHILO PLRNT
CUMULATIVE FREQUENCY
DISTRIBUTION FOR 3 HOUR
302 CONCENTRATIONS flT STflTION 6
HINU3 BRCKGROUI4Q
CflLCULflTEO
0.0! 0 05 01 « 0.*
10 20
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 60. Philo plant cumulative frequency distribution for
3-hour S02 concentrations at station 6. Nunber of
measured concentrations r 5012; number of calculated
concentrations = 8760
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
tf .* »* •
1* *•
•0 70 CO SO 4O JO 20
r--
to-
in-
(V-
oo
i 0.5 o.t o.i
4 1 1—H-
PMILO PLPWT
CUMULflTIVE FREQUENCY
OISTRIBUTIOhJ FOR £14 HOUR
soe cofJCErnRfiTiaws nr STRTIOW 6
AMEflSUREQ MIUU5 BRCKGROUNO
4.CflLCULfiTEQ
o.oi
aot aotatoit at i
Z 5 10 10 JO <0 50 «0 70 00 K)
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
»• *»
•».* »».»
Figure 61. Philo plant cumulative frequency distribution for
24-hour S02 concentrations at station 6. Number of
measured concentrations = 157; number of calculated
concentrations = 365
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
o>
ro
PHILO PLflNT
CUMULRTIVE FREQUF.NCT
DISTRIBUTION! FOR 1 HOUR
5C2 C3MCENTRRTIOMS flT flLI STATIONS
MINUS BfiCKGRQUNO
CfiLCULfiTEO
0.01 0.05 OJ 0-J O.S
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 62. Philo plant cumulative frequency distribution for
1-hcur S02 concentrations at all stations. Number of
measured concentrations = 38471; number of calculated
concentrations « 52560
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
00
99 98 »» 9O 80 TO CO SO 4O JO 20
PhlUO PLPNT
CUHULflTlVE FREQUENCY
DISTRIBUTION FOR 3 HOUR
502 CQNCENTRflTIONS OT fiLL 3TRTION3
MINUS BACKGROUND
+CflLCULflTED
o.oi o.o»oioi as
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE.
Figure 63. Philo plant cumulative frequency distribution for
3-hour S02 concentrations at all stations. Number of
measured concentrations = 39,285; number of calculated
concentrations = 52,560
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»».» !*•
»•
oo
PHILO PlflNT
CUMULRTIVE FREQUENCY
QISTBlBUTIOfJ FOR 34 HOUR
502 COMCENTRflTIOMS flT flLL STflTIOMS
MIMU5 BflCKGROUNO
COLCULflTEO
O.O1 OAS OJ ftl 0.5 1 t 5 1O 2O JO 40 50 60 70 60
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 64. Philo plant cumulative frequency distribution for
24-hour S02 concentrations at all stations. Number of
measured concentrations = 1290; number of calculated
concentrations = 2190
-------
Table 3.
J. M. STUART PLANT 1-HOUR CONCENTKATTON DISTRIBUTION
STATISTICS FOR MEASUREMENTS AND MODEL VALIDATION RUN
Station
1
2
3
4
5
6
7
All
Ninety-fifth
percentile*
Mb
140
80
lit
53
28
43
33
59
Pc
< 10
< 10
26
< 10
< 10
< 10
< 10
< 10
Ninety-ninth
perccntile8
M
270
445
200
180
80
ns
102
220
P
400
180
240
130
< 10
120
30
151
Second
highest
M
685
685
1022
750
495
980
325
1022'J
P
1372
814
565
515
823
595
976
n/?d
Highest
M
857
1014
1153
883
565
1053
'OS
3153
P
1393
948
1022
541
1219
693
1000
1393
"Percent lie values given In terms of cumulative percent of concentra-
tions less than given values.
Pleasured concentrations with subtracted background.
cPredicted concentrations.
dHighest concentration not exceeded more than once per year by any given
station.
Table 4. J. M. STUART PLANT 3-HOUR CONCENTRATION DISTRIBUTION STATISTICS
FOR MEASUREMENTS AND MODEL VALIDATION
Station
1
2
3
4
5
6
7
All
Ninety-fifth
percentile*
Mb
130
55
80
58
30
50
36
65
PC
11
15
50
10
< 10
< 10
< 10
13
Ninety -ninth
percentile*
M
270
420
160
150
83
130
120
190
P
260
330
140
110
53
107
100
150
Second
h i ghe s t
M
471
483
567
448
419
772
235
772d
P
762
415
355
315
415
275
505
762d
Highest
M
611
788
1048
883
470
981
389
1048
P
763
575
395
395
455
355
875
875
"percentile values given in terms of cumul.itivr f- _,...t of con-
centrations less than given v'1
Measured concentrations with subtracted background.
'predicted .. onccntrat ions.
Highest concentration not exceeded mor^. '.nan once per year by
any given station.
85
-------
Table 5. J. M. STUART PLANT, 24-HOUR CONCENTRATION DISTRIBUTION
STATISTICS FOR MEASUREMENTS AND MODEL VALIDATION RUN
Station
1
2
3
4
5
6
7
All
Ninety-fifth
percent lie*
Mb
83
46
50
40
31
42
45
47
PC
55
28
36
24
5
21
23
21
Ninety-ninth
percenttle*
M
245
160
110
63
52
133
69
115
P
128
52
75
41
50
46
60
63
Second
highest
M
25°
63
181
79
63
147
69
259d
P
149
75
91
45
3;
69
73
149d
Highest
M
277
159
225
83
77
195
77
277
P
161
98
102
49
75
83
120
161
Percentilc values given In terms of cumulative percent of concen-
trations less than given value*.
Measured concentrations with subtracted background.
Predicted concentration*.
Highest concentration not exceeded more than once per year by any given
etation.
Table 6. MUSKINCUM PLANT, 1-HOUR CONCENTRATION
DISTRIBUTION STATISTICS FOR
MEASUREMENTS AND MODEL VALIDATION RUN
(yg/m3)
%
Station
1
2
3
A
All
Ninety-fifth
percentile*
Hb
27
57
130
72
72
c
P
< 10
< 10
< 10
< 10
< 10
Ninety-ninth
percentile*
M
150
270
350
200
250
P
160
150
210
160
180
Second
highest
H
857
786
996
735
996d
P
r 0
1304
873
465
1304d
Highest
M
925
786
1179
786
1179
P
1083
1310
933
6A5
1310
Percentile values given in teras of cumulative percent of concentra-
tions less than given valuea.
Measured concentrations with subtracted back1"1"* " •*
Predicted concentrations.
Highest concentration nor
given station.
e-i wore than once per year by any
86
-------
Table 7. MUSKINCUM PLANT, 3-HOUR CONCENTRATION
DISTRIBUTION STATISTICS FOR
MEASUREMENTS AND MODEL VALIDATION RUN
Station
1
2
3
4
All
Ninety-Fifth
percent llea
Hb
28
70
130
71
73
PC
< 10
< 10
12
22
12
Ninety-Ninth
percentile*
M
130
225
325
170
225
P
180
150
150
100
UO
Second
highest
M
696
489
803d
410
803d
P
555
615
465
265
625d
Highest
M
823
489
838
707
838
P
645
625
495
285
645
Percentile values given in terms of cumulative percent of concen-
tration.-, less thnn given values.
Measured concentrations with subtracted background.
Predicted concentrations.
Highest concentration not exceeded more than once per year by
any given station.
Table 8. MUSKINGUM PLANT, 24-HOUR CONCENTRATION
DISTRIBUTION STATISTICS FOR
MEASUREMENTS AND MODEL VALIDATION RUN
(Mg/m3)
Station
1
2
3
4
All
Ninety-fifth
percentile*
Mb
32
55
98
52
66
Pc
32
32
31
24
28
Ninety-ninth
percent!!*"
M
100
100
130
95
120
P
69
80
58
41
66
Second
highest
M
133
131
165
109
170d
P
81
82
73
45
91d
Highest
M
170
137
227
115
227
P
97
91
74
47
97
of cimul'tive
b
Measured concentrations with subtracted background.
Predicted concentrations.
TUgheac concentration not exceeded more than once per year by any
given station. ' '
87
-------
Table 9. PHILO PLANT, L-HOUR CONCENTRATION
DISTRIBUTION STATISTICS FOR MEA-
SUREMENTS AND MODEL VALIDATION RUN
Station
1
2
3
4
5
6
All
Ninety-fifth
percentile"
Mb
50
37
47
27
35
118
53
PC
< 10
< 10
< 10
< 10
80
20
< 10
Ninety-ninth
pcrcentile«
M
170
163
163
190
134
253
183
P
98
222
920
88
555
650
443
Second
highest
M
525
735
745
665
575
565
745d
P
1295
945
4049
1945
1279
2369
4049d
Highest
M
893
891
917
695
675
595
917
P
1639
1059
4593
1981
1344
2482
4593
aPercentile values given in terms of cumulative percent of concentra-
tions less than given values.
Measured concentrations vith subtracted background.
Predicted concentrations.
Highest concentration not exceeded more than once per year by any
given station.
Table 10. PHILO PLANT, 3-HOUR CONCENTRATION
DISTRIBUTION STATISTICS FOR MEA-
SUREMENTS AND MODEL VALIDATION RUN
(ug/m3)
Station
1
2
3
4
5
6
All
Ninety-Fifth
percent lie*
Mb
51
39
44
34
35
100
53
Pc
< 10
28
111
< 10
130
110
57
Ninety-Ninth
percentllea
M
160
180
140
160
130
220
160
P
179
182
765
225
343
475
370
Second
highest
M
312
490d
451
377
399
381
490d
P
735
515
2572
1264
900
1175
2572d
Highest
M
466
70S
567
509
422
414
708
P
818
545
2572
1361
1078
1664
2572
Percent lie values given in terms of cumulative percent of con-
centrations less than given values.
b
Measured concentrations with subtracted background.
Predicted concentrations.
Highest concentration not exceeded more than once per year by
any given station.
-------
Table 11. PHILO PLANT, 24-HOUR CONCENTRATION
DISTRIBUTION STATISTICS FOR MEA-
SUREMENTS AND MODEL VALIDATION RUN
Station
1
2
3
4
5
6
All
Ninety-fifth
percent il >.a
Mb 1
45
35
44
41
23
65
45
Pi:
29
39
143
47
81
107
73
Ninety- tirst
frarcentilo
M
134
60
92
60
78
121
116
P
139
69
368
111
207
217
207
Second
highest
M
132
67
127
62
87
121
132d
P
133
86
471
165
222
282
471d
HI shea t
M
133
110
132
158
94
138
158
P
147
104
541 '
220
226
356
541
APercentlle values given in terms of cumulative percent of concentra-
tions less than given values.
^Measured concentrations with subtracted background.
CPr«dicted concentration.
Highest concentration not exceeded more than once per year by «ny
given station.
89
-------
Table 12. RATIOS OF MEASURED MINUS BACKGROUND TO PREDICTED
1-HOUR CONCENTRATIONS
Plant
Canal
Stuart
Muskingum
Philo
Station
1
2
3
4
1
2
3
4
5
6
7
1
2
3
4
1
2
3
4
5
6
Highest
1.55
3.45
1.44
1.33
0.62
1.07
1.13
1.63
0.46
1.52
0.44
1.08
0.77
1.00
1.39
0.54
0.84
0.20
0.35
0.50
0.24
Second
highest
1.72
3.18
1.00
1.35
0.50
0.84
1.80
1.46
0.60
1.65
0.33
1.12
0.80
1.08
1.40
0.41
0.78
0.18
0.34
0.45
0.24
Ninety. -ninth
percentile
16.8
72.0
9.0
31.0
0.68
2.47
0.83
1.38
8.0
1.13
3.4
7.5
1.29
1.17
1.00
1.73
0.73
0.18
2.16
0.24
0.39
90
-------
underpredicted stations are under 5 km away, but the model came closest
to predicting the farthest stations from the plant - No. 3, at 13 km.
The 24-hour concentrations were generally underpredicted by the model
except for Station 7 which it overpredic«-c;a and Station 5 which it pre-
dicted very closely. The predicted and calculated running three-hour
averages are in reasonably good agreement for the upper end of the dis-
tribution. Four stations were underpredicted and,three were overpredicted
Muokingum Plant Validation Results
The highest predicted 1-hour concentrations closely agreed with the mea-
sured concentrations for the Muskingum Plant. Stations 1 and 4 were under-
predicted. Station 2 was overpredicted and Station 3 was very closely
predicted, as was the combination of all-stations. Station 2 showed close
agreement between measured and predicted values for the 3-hour and 24-hour
concentrations, but all other stations were underpredicted. As can be
seen from Table 13, there appears to be a correlation between the ratio
of the second highest measured to predicted 1-hour concentration and the
plant-receptor distance, but due to the small number of stations no
statistical significance could be attached to this result.
Philo Plant Validation Results
Predicted 1-hour, 3-hour, and 24-hour concentrations were found to exceed
the corresponding measured values at each of the six measurement stations.
Only at station 2 were the model predictions reasonably close to the mea-
sured values. At stations 3 and 6 this overprediction may be directly
traced to the fact that the receptor is located at an elevation close to
that of the top of the stacks. Since the model accounts for the effect of
terrain by reducing the stack height by the difference between receptor
and stack base elevation, concentration^ will be overestimated for these
two stations unless a further correction is made to account for the effect
of terrain upon the plume itself. This overprediction for small source-
receptor elevation differences is responsible for the 0.74 correlation
91
-------
Table 13. CORRELATIONS
Correlation of ratio of second highest measured to
predicted 1-hour concentration versus distance
Plant
Canal
Stuart
Muskingum
Philo
All
Correlation
coefficient
estimate
0.16
0.89
0.88
0.15
0.25
95%
confidence
interval
-0.947 to 0.972
0.415 to 0.984
-0.526 to 0.997
-0.753 to 0.857
-0.204 to 0.615
Significance
none
significant to
none
none
none
1%
Correlation of ratio of second highest measured to
predicted 1-hour concentration versus elevation of
top of stack above receptor
Plant
Canal6
Stuart
Muskingum
Philo
All
Correlation
coefficient
estimate
0.82
-0.30
-0.65
0.74
0.14
95%
v confidence
interval
-0.66 to 0.996
-0.859 to 0.585
-0.992 to 0.829
-0.179 to 0.969
-0.310 to 0.539
Significance
none
none
none
none
none
92
-------
coefficient given in Table 13. Although at the other stations the over-
prediction problem is not as extreme, the method of stack height reduction
employed in the model is at least partially responsible for the poor
agreement.
Summary of Modeling Results
Based upon our model validation studies for these three Ohio power plants
we can make the following observations:
• Much better agreement is obtained between measured and cal-
culated concentration frequency distributions for the higher
concentrations. The poor agreement at lower concentrations
is due largely to uncertainties associated with the deter-
mination of background concentrations.
• The best agreement between measured and predicted concen-
trations was obtained for 1-hour and 3-hour concentrations
with geometric means of measured to predicted second
highest concentrations of 0.93 and 1.17 respectively. The
24-hour concentrations were generally underpredicted with a
geometric mean of measured to predicted concentration of
1.59. In the determination of these ratios, data from the
Philo Plant was excluded due to the effect of low stacks
and rugged terrain which may have affected the accuracy of
the model.
• The model has a tendency to underpredict concentrations at
larger distances (Table 13). The correlation between
source-receptor distance and measured to predicted second
highest concentration was, however, found to be statistically
significant only for the Stuart Plant.
• The treatment of terrain effects used by the model was found
to be inapplicable for those receptor locations with ele-
vation near stack height.
• The model validation results for these three plants were
quite different than those obtained from the initial vali-
dation stud>t> c..iducted at the Canal Plant in Massachusetts.
Concentrations from this seacoast facility were considerably
underpredicted for all stations and averaging times.
93
-------
SECTION V
ANALYSIS OF CONCENTRATION RATIO DISTRIBUTIONS
ANALYSIS OF PRESENT STUD*
The peak 1-hour to average 3-hour ratio must be between 1 and 3.
Likewise the peak L-hour to average 24-hour ratio has a range of 1 to
24. Since the cumulative distributions are bounded by a maximum and
minimum value it is difficult to describe them in terms of standard types
of distributions such as normal or log-normal. The distributions are
closer to being log-normal than normal, as can be seen when they are
graphed on the log-normal probability paper in Figure 65, for the J. M.
Stuart Plant, and the normal probability paper in Figure 66. Distributions
for the Muskingum and Philo Plants are shown in Figures 67 through 70. An-
other complication arises from the fact that ta,a original concentration
values were recorded to the nearest 0.01 ppm. This leads to the ratio dis-
tributions being discrete in nature. The most obvious example of this can
be seen from the peak 1-hour to average 3-hour normal plot in Figure 66.
There is a large jump in the curve as the ratio approaches 1.5. This
is due to the large number of combinations of three discrete consecutive
1-hour concentrations which can cause a ratio of 1.5. If the three con-
centrations are x. , x2, x and x is the concentration for the peak hour,
then if x2 + x_ = x the ratio will be 1.5. Examples of this would be
(0.01, 0.01, 0), (0.01, 0, 0.01), (0, 0.01, 0.01), (0.02, 0.02, 0) etc.
The statistics associated with these ratio distributions are given in
Table 14. In addition to the ratio distribution statistics for the three
Ohio power plants, we have also listed the results for the Canal Plant
6 2
study and those obtained by the Tennessee Valley Authority (TVA) in the
94
-------
vO
o
cc
o
90
BO
70
60
50
40
30
10
9
8
7
6
5
99
PERCENTAGE OF CONCENTRATION RATIOS
LESS THAN INDICATED VALUE
? 9.8 9.5 9.° 8° 7060504030 20 10 3 2 I OJ 0.2 0.005 O.q
T 1 1 1
LEGEND
1-24 HOUR CONCENTRATION
RATIO
1 1—IT
•1-3 HOUR CONCEN-
TRATION RATIO
J.M. STUART PLANT
LOG PROBABILITY PLOT OF
CUMULATIVE RATIO DISTRIBUTIONS
J—i—i 1
J L.
0.01 0X35 OS I 2 5 10 20 30 40 5060 70 80 90 93 98 99 99.3
PERCENTAGE OF CONCENTRATION RATIOS
GREATER THAN INDICATED VALUE
99.99
Figure 65. J. M. Stuart Plant log probability plot of cumulative racio distributions
-------
vO
99.99 99.9
PERCENTAGE OF CONCENTRATION RATIOS
LESS THAN INDICATED VALUE
99 98 95 90 80 70 60 50 4030 20 10 5
03 0.2 0.005 0.01
2 3.0
(T
z 2>6
O
< 2.2
o:
z
| 1.8
o
o
a: '•«
X
it}
1 1.0
— <
LEGEND
1-24 HOUR CONCENTRATION
RATIO
1-3 HOUR CONCEN- J-M. STUART PLANT
TRATION RATIO LINEAR PROBABILITY PLOT OF
CUMULATIVE RATIO DISTRIBUTIONS
„ t
\ 1
1 1
\ \
1 \
1 1
\ \
\ \
\ J
\ \ *"
x \
x>. \_^^
^ x\
^N^. ^^
^^ "^ ^_
llllll I I Illlll IV 1 "~ j""~ ~-l l ii
XOI 0.05 a5 1 2 5 10 20 30 40 506O 70 80 90 95 99 99 63.5 9
O
24.0 ^
z
o
19.4 jr
oc
H-
14.8 z.
Ul
o
z
10.2 S
f
c
5.6 X
M
i
i.o -
9.99
PERCENTAGE OF CONCENTRATION RATIOS
GREATER THAN INDICATED VALUE
Figure 66. J. M. Stuart Plant linear probability plot of cumulative ratio
distributions
-------
Table 14. STATISTICS FOR RATIO DISTRIBUTION
Ratios
Arith-
metic
mean
Arithmetic
standard
deviation
507>
957.3
997.a
b
Cor'-^iat ion
957.
Confidence
interval
J. M. STUART PLANT
1-3 hourc
d
1-24 hour
1.86
7.71
0.76
5.94
1.55
5.95
1.00
1.93
1.00
1.40
-0.0584
0.00155
-0.07148 to -0.04530
-0.05081 to +0.05390
MUSKINGUM PLANT
1-3 hour
1-24 hour
1.99
9.23
0.76
6.79
1.74
6.65
1.00
2.38
1.00
1.77
-0.079
-0.151
-0.0949 to -0.0631
-0.2083 to -0.0927
PHILO PLANT
1-3 hour
1-24 hour
2.00
8.77
0.72
5.77
1.77
6.98
1.04
2.47
1.01
1.92
-0.36
-0.40
-0.3720 to -0.3479
-0.4474 to -0.3503
CANAL PLANTb
1-3 hour
1-24 hour
1.81
7.84
0.70
6.31
1.50
5.37
1.02
1.69
1.02
1.23
-0.017
-0.008
-0.0283 to -0.0057
-0.0573 to -0.0414
PARADISE PLANT2
1-3 hour
1-24 hour
aPercentile
values.
1.80
15.9
-
1.63
12.4
0.99
4.00
.
-
-
values given in terms of cumulative percent of ratios greater than given
Correlation between ratio and peak 1-hour concentration.
°Peak 1-hour to average 3-hour ratio for measured minus background S02 concentration.
Seak 1-hour to average 24-hour ratio for measured minus background S02 concentration.
97
-------
vicinity of the Paradise Power Plant with data taken over a 2-1/2 year
period from January 1968 through June 1970. The ratio statistics do not
vary significantly except for the Paradise Plant where the peak 1-hour
to average 24-hour ratios are greater by a factor of 2. The 1-3 hour
ratio means ranged from 1.80 at Paradise to 2.00 at Philo, and the
standard deviation associated with these ratio distributions ranged from
0.70 at Canal to 0.76 at Stuart and Muskingum. With the exception of
the Paradise Plant the 1-24 hour ratio means ranged from 7.71 at Stuart
to 9.23 at Muskingum, and the standard deviations ranged from 5.77 at
Philo to 6.74 at Muskingum.
The discrepancy between the 1-24 hour ratio distribution statistics for
Paradise and the other power plants could be due to the fact that at the
peak concentrations reported for the Paradise network were actually 5-
minute averages which had to be converted to the 1-hour averaging time
according to the method outlined in Table 5.1 of Turner's Workbook. The
fact that concentrations less than 0.10 ppm were excluded from the analysis
of the Paradise data could also be responsible for this difference.
Suggestions for Future Study
Since the primary application of. these concentration ratio distributions
would be the estimation of average 24-hour concentrations associated
with highest or second highest peak 1-hour concentrations, it would be
instructive to carry out the preceding time-concentration analysis for
those peak 1-hour concentrations above a given cutoff value. This pro-
cedure would avoid the problem of the distributions being weighted toward
those low concentrations near the threshold of the sampler. Another
approach which would prove useful in the extension of 1-hour concentra-
tions to longer averaging times would be the analysis of the behavior of
ratio distribution statistics for different meteorological conditions.
A study of this type performed during the Canal Plant study found a sig-
nificant increase in 1-3 hour ratios for the lower stability classes (A,B).
98
-------
so
vo
100
90
BO
70
60
50
40
30
99.99 999
O
5
(E
O
8
P
- LEGEND
PERCENTAGE OF CONCENTRATION RATIOS
LESS THAN INDICATED VALUE
S9 98 95 90 80 70 60 SO 40 30 20 10 5 ^ 15 0.2 0.005 OX*
I " I
T
T P
T 1 i I I
1-24 HOUR CONCENTRATION
RATIO
1-3 HOUR CONCEN-
TRATION RATIO
10
9
8
7
6
5
MUSKINGUM PLANT
LOG PROBABILITY PLOT OF
CUMULATIVE RATIO DISTRIBUTIONS
0,01 OX>9 C5 I 2 5 10 20 30 40 5060 70 80 90 95 98 93 69.3
99.99
PERCENTAGE OF CONCENTRATION RATIOS
GREATER THAN INDICATED VALUE
Figure 67,
Muskingum Plant log probability plot of cumulative
ratio distributions. Number of 1-3 hour ratios =
15,059; number of 1-24 hour rations = 1100
-------
DOT
1-3 HR. CONCENTRATION RATIO
oo
•t
(D
00
o c^ 3;
Kl H- C
a to
e-> rt ?T
to H- 3
4> cr OQ
O H-
c o ^
co to
n ' 3
to rt
rt
H- 2 t—'
O C H-
cr a>
i (D to
>-« o "O
O H» i-l
o o
f cr
i to
o
C
n- o
H- rr
O
in o
Mi
i
n
G s
- c
O *-•
in to
vO rt
w. (->•
3 (D
cr
ro
_
ERCENTAGE OF
GREATER THA
CONCENTRATION
N INDICATED VAL
™ >
Z—
O
_ — — to ro 01
Q •$* Q) ^} 0^ O
o
o
b
VI
P
N
W
O
8
Oi
o
o
Ol
o
8
a
o
to
o
w
w
<0
o>
<0
u>
^
i*'
Ol
<0
J 1 1 1 1
__,J
•/^^
1
1
. /
1
•1
•J
'
1
1
1
(till
£- p, 5 - - N
1
1
^* 1
•° w
H I
0°
z c
> o
i-
0 0
in
z
MUSKINGUM P
LINEAR PROB
CUMULATIVE
so >r
J* LIT
O _j H
S"*
3?
30 O
rn *"4
C
g?t
2
(A
1<0
f
1 O
3) T§ -
0 i
o
c
9
^N
II II
:ONCENTRATIO
Z
•
(O
g
*
0
S
»
«>
m
w
o
8
0
Ul
o
o
S
o
Ol
r»
^
o
Oi
p
p
8
1H
O
C
«B
ERCENTAGE OF
LESS THAN
CONCENTRATION 1
INDICATED VALUE
3a
6
ro a> -A b
1-24 HR. CONCENTRATION RATIO
-------
100
90
80
70
60
50
40
30
20
93.99 999
O
K.
\-
•z
O
O
10
9
8
7
6
5
PERCENTAGE OF CONCENTRATION RATIOS
LESS THAN INDICATED VALUE
99 98 95 90 80 70 60 50 40 30 20 10 5 2 \ _.S 0.2 0.005 0.01
LEGEND
1-24 HOUR CONCENTRATION
RATIO
---H-3 HOUR CONCFN-
TRATION RATIO
PHILO PLANT
LOG PROBABILITY PLOT OF
CUMULATIVE RATIO DISTRIBUTIONS
\
0.01 0.05 OS I 2
10 20 30 40 5060 70 80 90 95 98 99 99.3
PERCENTAGE OF CONCENTRATION RATIOS
GREATER THAN INDICATED VALUE
99.99
Figure 69. Philo Plant log probability plot of cumulative ratio distributions.
Number of 1-3 hour ratios = 20,142; number of 1-24 hour ratios r 1,152
-------
o
ro
93.99 999
2 5.0
(C
z
o
2.6
< 2.2
S 1.8
o
o
1.4
PERCENTAGE OF CONCENTRATION RATIOS
LESS THAN INDICATED VALUE
99 93 95 90 80 70 60 50 40 30 20 10 5 21 0.5 0.2 0.005 0.01
LEGEND
1-24 HOUR CONCENTRATION
RATIO
1-3 HOUR CONCEN-
TRATION RATIO
PHILO PLANT
LINEAR PROBABILITY PLOT OF
CUMULATIVE RATIO DISTRIBUTIONS
tc
if)
— 0.0r0j05 a» I 2 5 JO 20 30 40SOGO 70 80 go 93 98 S3 99.3
PERCENTAGE OF CONCENTRATION RATIOS
GREATER THAN INDICATED VALUE
O
H
24.0
19.4
Z
o
£C
14.8 g
o
10.2 8
5.6
cc
CJ
i
99.99
Figure 70. Philo Plant linear probability plot of cumulative ratio distributions.
Number of 1-3 hour ratios = 20,142; number of 1-24 hour ratios = 1,152
-------
SECTION VI
FURTHER ANALYSIS OF MODEL VALIDATION PROCEDURES
A comparison of the frequency distributions of the model calculations
and the observed 1-hour concentrations shows that the model predicts the
upper percentile fairly well, but significantly underpredicts most of
the remainder of the distribution. A similar effect occurs in the fre-
quency distributions of the 24-hour concentrations. Part of the under-
prediction may be due to sampler errors since many of the lower concen-
trations are measured near the threshold of the sensing device. Also,
much of the low concentration end of the distribution does not represent
pollution from the plant at all, but rather differences between the esti-
mated background and the actual background at the sampler. For example,
if three samplers upwind of the plant recorded concentrations 10, 20 and
45 ng/m3, the "background" would be considered the average of the upwind
stations, in this case 25 ug/m3. This "background" is subtracted from
each concentration recorded at that hour, so that, in this case, we have
two negative concentrations, and one positive value of 20 ug/m . Corres-
ponding model predictions would, quite correctly, be zero. When the
background is added to the predicted concentrations, the predicted and
measured concentrations appear to be in better agreement for the lower
concentrations as shown in Figures 71 through 86 for the J. M. Stuart
Plant receptor locations. This apparent improvement in model predictions
at low concentrations is largely a cosmetic effect, however, since for
the most part we are comparing background concentrations with themselves.
103
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
. M. STUflRT PtflNT
.UMULflTIVE FREQUENCY
DISTRIBUTION FOR 1 HOUR
S02 CONCENTRflTIONS flT STflTION 1
C/lEflSUREO
APfiEOICTEO PLUS BACKGROUND
0.01
i » 10 zo x> «o so «o TO eo
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 71. J. M. Stuart Plant cumulative frequency distribution for
1-hour S0? concentrations at station 1
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
CUMULflTIVE FREQUENCY
DISTRIBUTION
FOR 1
S02 CONCENTRATIONS
C/iEflSUflEO
APRE01CTEO PLUS BRCKGROUNO
HOUR
flT STflTION
0.01 &MOSO1 &» t
•• t» •••• Ml*
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 72. J. M. Stuart Plant cumulative frequency distribution for
_ . *, **. ^^_*.^.k£ A.MK. r* >fc^ ^»H**f"4 f\TF\ f
1-hour S0» concentrations at station 2
-------
ot>-
in-
o
eit-
o
0»
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»» *• ts «o
6O 7O CO SO 4O JO ZO
10
I O.S O.2 0.1
» I •
J. M. STUflRT PLRNT
CUMULflTIVE FREQUENCY
DISTRIBUTION FOR 1 HOUR
502 CONCENTRATIONS RT STflTION
mKEBSUBEQ
APREOICTtO PLUS BfiCKGROUNO
0.01 aos 04 u a> t
z s 10 zo so 40 so «o TO eo »o
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
»* t»
Figure 73. J. M. Stuart Plant cumulative frequency distribution for
1-hour S09 concentrations at station 3
-------
PERCENTAGE OF CONCENTRATIONS
GREAfER THAN INDICATED VALUE
t».» »«.!
»» 98 »J SO 80 TO tO 50 40 JO ZO >O 9 21 O.5 O.2 0.1 O.OI
^PREDICTED PLUS BflCKCHOUNQ
o.o: o.o» 01
9 10 20 30 40 SO 60 70 *0 90
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
•»
t»
Figure 74. J. M. Stuart Plant cumulative frequency distrilution for
1-hour SO,, concentrations at station 4
-------
01-
oo-
to-
cr>
O
00
LU
O =•-
O ro-
O
ru-
»»
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
*• tj »0 »O TO 60 iO 40 SO 20 10
i as oz 01 o.oi O
J. M. STUflRT PLRNT
CUMULRTIVE FREQUENCY
DISTRIBUTION FOR 1
502 CONCENTRRTIONS
OfiEHSUREO
^PREDICTED PLUS BflCKGROUND
HOUR
RT STRTION 5
O.OJ 0-OJ040J 0.9 I
S 3 JO 20 SO 40 SO «0 10 80 »0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
ft Vt
•*.•
»**
Figure 75. J. M. Stuart Plant cumulative frequency distribution for
1-hour SO. concentrations ac station 5
-------
»».» 99 8
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»» *R 95 90 BO 7O SO JO 40 30 20
J. M. STUflflT PLRNT
CUMULflTIVE FREQUENCY
FIT STflTION 6
PREDICTED PLUS BflCKCflOUNO
o.ot o.osoJOLt
99 8 99.9
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
999
Figure 76. J. M. Stuart Plant cumulative frequency distribution for
1-hour SC2 concentrations at station 6
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
*» »« »s so ao ro co so «o so to 10 » 21 o.s o.z o.i o 01
PREDICTED PLUS BRCKGROUNO
O.Oi O.OS CU CU O.S
»«.*
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 77. J. M. Stuart Plant cumulative frequency distribution for
1-hour S0? concentrations at station 7
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
J. M. STUflRT PLflNT
CUMULATIVE FREQUENCY
DISTRIBUTION FOR 1 HOUR
502 CONCENTRflTIONS flT flLL
CjMEfiSUREO
^PREDICTED PLUS BflCKGROUNO
STflTIONS
0.01 0.03 04 O2 0.5 I
•».* »«.»
9»S
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 78. J. M. Stuart Plant cumulative frequency distribution for
1-hour S0? concentrations at all stations
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
f* «^
<'~> 994 99.1 99 9* 91 9O »0 7O CO SO 4O SO 20 10 1 21 0-S 0.2 0.1 O.O1 O
OO-
r—
CO-
LO-
r_ 03-
."Z. m-
uj
C_) s>*-
z
C» co-
o
(M-
. 'M. STURRT PLRNT
PREDICTED PLUS 8BCKCROUNO
0.01 O.OS 0.1 O2 0.} 1
ZO 90 40 SO 60 70 *0 90 9S
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
9« »9
99.* 999
9*9
Figure 79. J. M. Stuart Plant cumulative frequency distribution for
24-hour SO concentrations at station 1
-------
u>
o
*».» »».»
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»» »S 93 90 »O 70 CO 10 4O 10 K>
CONyiR?!^RMcr
0.01 0.0)0102 0.» 1 2
20 30 40 50 60 70 SO
90 «J
•a «9
»».• »».»
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
*»»
Figure 80. J. M. Stuart Plant cumulative frequency distribution for
24-hour SO concentrations at station 2
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
J. M. STUflRT PlflNT
CyMULRTIVE FREQUENCY
ISTRI8UTIGN FOR 24 H
_G2 CONCENTRflTIONS flT
QMEfiSUREO
A.PBEQICTEO »LUS SfiCKCftOUMO
R
TflTION
o.oi o.otaiu o.i i
t 5 1O 10 X) 40 tO tO 70 SO 90
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 81. J. M. Stuart Plant cumulative frequency distribution for
24-hour SO concentrations at station 3
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
eo-
co-
to-
»* M »5 1O (O TO CO 90 4O JO
-| »_| 1 1 t I 1 t I t
to
X 1 0» OX 01 001
M. STUflRT PLflNT
CONCENTRflTIONS fl
PLUS BflCKCROUNO
o
oxi ojjs t
s » 10 20 so 40 so to TO w> »o
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
t».i ML*
Figure 82. J. M. Stuart Plant cumulative frequency distribution for
24-hour SO concentrations at station 4
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
J. M. STURRT PLflNT
CUMULflTIVE FREQUENCY
DISTRIBUTION FOR 24 HOUR
502 CONCENTRflTIONS RT STflTION 5
^PREDICTED
o.oj
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»».»
M *•
f
0.01 0.0 J 04 04 0.5 1
2 » 10 20 SO 40 50 60 70 (0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 84. J. M. Stuart Plant cumulative frequency distribu .ion for
24-hour SCL concentrations at station 6
-------
00
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
oo-
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
NO
. M. STUflRT PLflNT
LJMULflTIVE FREQUENCY
DISTRIBUTION FOR 2U HOUR
502 CONCENTRATIONS
0ȣftSUflED
PLUS BRCKGnOUKO
STflTIONS
O.OJ e,0»040L> 0.5 I
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 86. J. M. Stuart Plant cumulative frequency distribution for
24-hour S0_ concentrations at all stations
-------
The method of determining background concentrations from plant wind di-
rection data was examined more closely since the local wind sensors were
seldom at the same height or location as the stacks. The plots in Figure
87 of the background concentration at the three plants indicate some
rather high levels. The high background concentrations apparently occur
when there is only a single upwind station reporting a high concentra-
tion, either due to a high local emission or a discrepancy between the
actual transport wind direction and the reported "ind direction. The
highest background recording ac Stuart - 650 ug/m - occurred on May 23,
1973 at 1400 hours, due to the following recording.
Station
1
4
5
2,3,6,7
Concentration
0.01 ppm
0.01 ppm
0.25 ppm
no report
Bearing of station
from plant
35°
49°
279°
The wind was recorded as blowing from 247 and toward 67 which caused
stations 1 and 4 no be considered within the 90 sector of the plumes
centerline. Stations 1 and 4 were considered downwind of the plant and
not used for background subtraction, while statit?,. T, was considered up-
3
wind and a background of 0.25 ppm or 650 ug/m was obtained. The plots
in Figure 88 were made of the concentrations when the stations were up-
wind of the plant, to determine if local sources were contributing to
any particular station. All seven stations show the same trend, although
station 6 seems to have the highest upwind concentrations. There is no
simple explanation for this because station 6 is one of the more remot-p.
stations (Figure 2) although there may be local s-... ..-.> not apparent on
the IJSGS map. Since there were many cases of high upwind concentrations,
it was decided to try a simple background calculation technique which
was independent of wind direction. The procedure adopted was to find
120
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
BPCKGRQUNO
CUMULPTIVE FREQUENCY
DISTRIBUTION FGR i HOUR
SQ3 CQNCENTRflrlQNS flT
OJ. M. STUflRT PLflNT
AMU5KINGUM RIVER PLflNT
+PHILQ PLflNT
0.01 O.OJ040J at 1 I 5 10 10 JO 40 to tO TO (0 »0 »i «l t» •«.( »»» »»»
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 87. Background cumulative frequency distribution for
1-hour SO concentrations at J. M. Stuart Plant,
Muskingum River Plant and Philo Plant
-------
N>
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
J. h. STUPRT PLRN'T
CUMULRTIVc FfiEQUEMCY
DISTRiaUTJOM FOR 1 HOUR
UPWIND '503 CC.slCENTRftTIONS
57* 7 IOU3
O.Ol O.04 OJ OX 0.5 I
t » 10 20 JO 40 SO 60 TO BO »0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
•} *• ••
Figure 88. J. M. Stuart Plant cumulative frequency distribution for
1-hour upwind S0? concentrations at 7 stations
-------
the mean and standard deviation of concentrations for all monitoring
stations every hour. A station whose concentration was above the mean
plus one standard deviation was disregarded for that hour, and the back-
ground was taken to be the mean of the remaining stations. The new back-
ground computed from this technique is shown with the old background in
Figure 89. The new background has the same slope as the old, but does
not have the same high concentration values.
New measured minus background curves are shown in Figures 90 to 96 for
the 1-hour case, and in Figure 97 for the 1-hour "all station" case.
These results indicate that the two background subtraction methods yield
similar results except for the highest values. As seen from Table 15,
the second technique shows better agreement with the highest predicted
values. Since the alternate technique yields a smoother background
cumulative frequency distribution (Figure 98), is slightly closer to the
predicted values, and requires no plant wind data, it may be the better
of the two methods, and deserves future study.
SUGGESTIONS FOR FUTURE STUDY
There are several possible ways to improve the agreement between measured
and predicted concentrations.
• The model hourly output should only include those
hours during which a monitoring station was operat-
ing. The predicted concentration plots shown are
plots of all hours for the year, while the plots
of the measured values have some missing hours. For
instance, at the J. M. Stuart Plant, Station 2 operated
only from January to March, Station 4 operated only
from March to December, and Station 7 operated only
from January to July. Comparing predicted hours
only to those actually measured may yield closer
agreement,
123
-------
00-
r~
(O
IT.
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
« I
-I h
98
—t-
• »
t-
«0 7C SO SO 40 10 20
BflCKGflOUND
CUML'LflTIVE FREQUENCY
DISTRIBUTION FOR 1 HOUR
S02 CONCENTRATIONS flT
«. STUflflT PLflNT
2 1 0.9 01 0.1 0.01
-*—t 1 1 t.
-CO
-to
-in
-<0
o.oi o os 01 oj as t
t s 10 20 x> «o so to TO »o
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
»o »s
ft •*
•*»
Figure 89. Background cumulative frequency distribution for
1-hour SO concentrations at J. M. Stua L Plant
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
NJ
Ul
«» »» ti »O CO TO iO SO 40 JO ZO
STUflRT PLflNT SUBTRACTION TECHNIQUE «2
CUMULfiTSVE FREQUENCY
DISTRIBUTION FOR 1 HOUR
S02 CGNCENTRflTIONS flT STflTION 1
AHEftSUREO MINUS BflCKGROUNO
+MEflS-BaCK WITH NEW TECHNIQUE
O.Ol O.OS OJ 02 O.S 1
80
»»
»B » 99.9
»99
£ i 10 20 JO 40 tO 60 70
PERCENTAGE OF CONCENTRATIONS
LESS THAM INDICATED VALUE
Figure 90. Stuart Plant subtraction technique #2 cumulative frequency distribution for
1-hour S0_ concentrations at station 1
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
•O 70 £0 50 4O 30 20
STUPRT PLPMT SUBTRflCTIOtf TECHNIQUE
CUMULflTIVE FREQUENCY
DISTRIBUTION! FOR 1 HOUR
S02 COWCE^TRflTIONS flT STflTIOM 2
QHEfiSUREO
AMEfiSUREO MINUS BflCKGRGUND
.MEflS-BflCK WITH NEU TECHMIOUE
0.01 0.0} O4 07 0.5
t 5 10 20 30 40 50 60 70 60 SO
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 91. Stuart Plant subtraction technique #2 cumulative frequency
distribution for 1-hour SO. concentrations at station 2
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
99 98 93 SO 80 70 CO SO 40 JO ZO
3TUPRT PLflNT SUBTRftCTION TECHNIQUE *2
CUMULATIVE FREQUENCY
DISTRIBUTION FOR 1 HOUR
502 CONCENTRATIONS flT STflTION 3
QtlEfiSUREQ
AMEfiSUREO MINUS BflCKCPOUND
4-MEflS-BflCK WITH NEU TECHNIQUE
0.01 O.OS OJ OJ 0.9
I S 10 20 JO 40 10 «0 70 eo 90
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
9» 99
99 • 999
999
Figure 92. Stuart Plant subtraction technique //2 cumulative frequency
distribution for 1-hcur SO concentrations at station 3
-------
NJ
00
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
I O.1 0,1 O.i
.0. O
0.01
»» »• tt 90 SO TO «0 SO 40 SO 20
STUPRT PLfiMT SUBTRACTION TECHNIQUE «2
CUMULflTIVE FPEQUENCY
DISTRIBUTION FOR 1 HOUR
S02 CONCEKlTRflTIONS fiT STATIOM
AM£RSUREO MINUS BflCKGROUNO
+M£flS-eflCK WITH NEM TECHNIQUE
0.01 O.Oi 04 OJ O.i I
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 93. Stuart Plant subtraction technique #2 cumulative frequency
distribution for 1-hour SO concentrations ?t station 4
-------
**.* »» a
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
X 9« 94 »0 60 TO CO 5O 40 3D 20
N>
SO
STUPRT PLflNT SUBTRRCTI3N TECHNIQUE «2
CUMULATIVE FREQUENCY
DISTRIBUTION F3R 1 HOUR
S02 CONCEMTRftTIONS flT STRTIOW S
0HEflSUREO
AHEflSUR:D MINUS BflCKGROUNO
+MEflS-BflCK WITH NEW TECHNIQUE
0.01 O-OSWOJ O.S t
5 10 20 JO 40 SO 60 7O 60 »C
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
55
»9.a 39.*
999
Figure 94. Stuart Plant subtraction technique #2 cumulative frequency
distribution for 1-hour S02 concentrations at station 5
-------
U)
O
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
I O.3 O.2 0.1 0.01
.01 O
STUflRT PLflMT SUBTRflCTIQM TECHNIQUE «2
CUKULRTIVE FREQUENCY
OISTRIBUTIOM FOR 1 HOUR
SG2 CONCEWTflHTIOWS flT STflTION 6
oMEflSURED
AMEflSURED MINUS BfiCKGROUWO
4.MEflS-BfiCK WITH KEW TECHNIQUE
o.oi e.osoi&z as a
t 9 10 20 so to ;o so TO
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
t*
>*.• »*»
»*»
Figure 95. Stuart Plant subtraction technique #2 cumulative frequency
distribution for 1-hour SO concentrations at station 6
-------
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
u>
»» «8 »9 »0 80 70 CO SO 4O JO 20
STUPRT PLflMT SUBTRflCTIOM TECHNIQUE
CUMULATIVE FREQUENCY
DISTRIBUTION FOR 1 HOUR
502 CONCENTflflTIONS RT STflTION 7
QMEPSURED
AM£flSURED MINUS BflCKGROUND
+MEflS-BflCK WITH NEW TECHNIQUE
O.OS 0.05 01 Oi O.S 1
t S 1O 20 30 40 SO £0 70 80 >0
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 96. Stuart Plant subtraction technique #2 cumulative frequency
distribution for 1-hour SO concentrations at station 7
-------
CO-
n--
to-
to
cr
tr.
UJ
CJ
O
O
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
»J 9» I
1- t t
»» »»
•O TO SO 50 40 SO ZO
10
I O.5 O.2 O.t
STUflftT PLfl^T SUBTRflCTION TECHNIQUE
CUHULflTlVE FREQUEMCT
OISTRiaUTIOM FOR 1 HOUR
502 COMCEWTflflTICMS flT flLL STftTICNS
AHEflSUREO MINUS BflCKGROUNO
+MEflS-BfiCK WITH NEW TECHNIQUE
lit
0.01 0.01 0-S Oj 0.9 i I 9
H 1 1
Jo
-------
Table 15.
J. H. STUART, CONCENTRATIONS DISTRIBUTION STATISTICS FOR
MEASURED MINUS BACKGROUND AND PREDICTED CONCENTRATIONS
USING OLD AND NEW BACKGROUND SUBTRACTION TECHNIQUES
1-Hour
Station
1
2
3
4
5
6
7
All
Second highest
Measured
685
685
1022
750
495
980
325
1022d
b
Measured
685
665
1009
735
615
980
433
1009d
c
Predicted
1372
814
565
515
823
595
976
1372d
Highest
Measured
857
1014
1153
883
565
1053
435
1153
Measured
886
943
1132
817
625
1053
438
1132
Predicted0
1393
948
1022
541
1219
693
1000
1393
24-Hour
1
2
3
4
5
6
7
All
259
63
181
79
63
147
69
259d
225
57
150
69
75
188
85
225d
149
75
91
45
57
69
73
149d
277
159
225
83
77
195
77
277
235
161
210
84
80
197
88
235
161
98
102
49
:75
83
120
161
Pleasured concentrations with subtracted background using old wind
dependent technique.
Measured concentrations with subtracted background using new wind
independent technique.
Predicted concentrations.
Highest concentration not exceeded more than once per year by any
given station.
133
-------
U)
PERCENTAGE OF CONCENTRATIONS
GREATER THAN INDICATED VALUE
*».» 99.8
99 93 55 90
eO 70 CO 50 4C JO 20
1O
Ol-
03-
t/i-
cn
O
en
cc.
Cj~
»3
r—-
UJ
O
2:
O
O
ru-
t o.s o.z o.)
-»—• » t ••
o.oi
STUflRT PLflMT SUBTRACTION TECHMIOUE «2
CUMULflTIVE FREQUEMCT
DISTRIBUTION! FOR 21* HOUR
502 CONCEMTRfiTIONS flT flLL STflTIQfJS
QMEflSUREO
^MEflSURED MINUS BflCKGROUNO
+HEflS-BfiCK WITH NEW TECHNIQUE
H—I—I 1—h
O.OJ 0.05 010J 0.9 I X
20 SO *0 iO 60 70 80 90 9S 98 »9
PERCENTAGE OF CONCENTRATIONS
LESS THAN INDICATED VALUE
Figure 98. Stuart Plant subtraction technique #2 cumulative frequency
distribution for 24-hour SO,, concentrations at all stations
-------
The model used wind data from airports which are fairly
distant. Running the model with wind data taken from
the plant wind instrumentation may yield better corre-
lation, although the plant wind instruments only
measured wind characteristics of the lower valley, and
not those at plume height or at the monitoring stations.
Wind direction may vary with altitude, so the wind
direction at the top of the stacks and at plume height
may be different than the measured wind direction.
Varying the measured airport wind by a constant angular
displacement may yield better agreement between measured
and calculated values, but still would not account for
the variation of wind direction with height which results
in a greater horizontal plume spread than that predicted
by the model.
The method of background subtraction by determining
plume direction from plant wind data may not be the best,
since the plant wind data is more characteristic of the.
lower valley. An alternate method would be to choose
the lowest concentration among the monitoring stations
as the background concentration for the hour in question.
Buoyancy flux for each stack was assumed to be constant
while this parameter actually varies as a function of
the generation load for each boiler. This effect could
be included in the model if the buyoancy flux were made
proportional to the firing rate.
The model was not designed to handle receptors level
with the top of the stack, so that it overpredicted the
high concentrations at the Philo sampling locations.
Assuming that the problem occurs in the model and not
in the receptors, the model could be altered to handle
cases of low plume rise and narrow spread. First, an
initial dispersion such as a virtual source image could
be added to compensate for multiple stacks being treated
as a single stack, or a single stack with multiple wind
directions could be used. Secondly, the method of de-
termining stability class could be modified. The highest
predicted value at Philo occurred when a <~iass 4 stability
hour followed a class 7 hour. To avoid rapid fluctuation
of stability, the program changed the class 4 to a class
6 which hao the narrowest plume spread. Whether this hour
135
-------
was a class 4 as measured, or a class 6 as predicted
is hard to say, but perhaps allowing a class 5 in this
instance may have been closer to actual average con-
ditions. Thirdly, Lhe modified model used for this
study allowed the receptor elevation to be subtracted
from the plume height, but did not allow the plume to
rise as the terrain did. Allowing some rise for
neutral and unstable cases may prove wori-'awhile.
Fourthly, the wind during stable conditions usually
fluctuates, and the plume rise and spread coefficients
for stable classes should be looked at more closely to
ascertain whether or not they actually hold for an
hour.
The Single Source Model should be modified to provide
for the incorporation of other techniques for the de-
termination of horizontal and vertical dispersion co-
efficients. Dispersion calculation methods which could
be tested with the data from this study include those
due to F. B. Smith,7 Smith-Singer,8 and G. A. Briggs,
136
-------
SECTION VII
REFERENCES
1. Turner, D. B. Workbook of Atmospheric Dispersion Estimates.
Environmental Protection Agency, Office of Air Programs.
Publication No. AP-26. p. 84.
2. Montgomery, T. L., S. B. Carpenter, and H. E. Lindley. The
Relationship Between Peak and Mean S02 Concentrations. Con-
ference on Air Pollution Meteorology of the American Meteoro-
logical Society in Cooperation with the Air Pollution Control
Association. Raleigh, North Carolina. April 5-9, 1971.
3. Klug, W. Dispersion From Tall Stacks. Report on Activities
During Visit with Environmental Protection Agency, Division
of Meteorology. August 5 through October 5, 1973.
4. Hrenko, J., D. B. Turner, and J. Zimmerman. Interim User's
Guide to a Computational Technique to Estimate Maximum 24-Hour
Concentrations from Single Sources.
5. Briggs, G. A. Some Recent Analyses of Plume Rise Observation.
Proceedings, Second International Clean Air Congress. H. M.
Englund and W. T. Beerg (cds.). Academic Press. New York.
p. 1029-1032.
6. Mills, M. T. Comprehensive Analysis of Time-Concentration Rela-
tionships and the Validation of a Single Source Dispersion Model,
GCA/Technology Division. March 1975.
7. Smith, F. B. A Scheme for Estimating the Vertical Dispersion
of a Plume From a Source Near Ground Level. Proceedings, Third
Meeting of the Expert Panel on Air Pollution Modeling. A
Report of the Air Pollution Pilot Study, NATO Committee on
the Challenges of Modern Society. Paris, France. XVII, 1-14.
October 2-3, 1972.
137
-------
8. Siiu'.ri-, I. A., and M. E. Smith. Relation of C.uslincss to
- Other Meteorological Parameters. J. Meteorology, 10(2),
121-126, 1953.
9. Briggs, G. A. Diffusion Estimation for Small Emissions.
U.S. Department of Commerce. NOAA-ERL-ARATDL Contribution
No. 79 (draft). Oak Ridge, Tennessee. May 1973.
138
-------
TTCHNICAI. nr.roiu DATA
I'lfiitf rend //uj/ur/KiiM un Ilic mmr hr/orc coin/
>lc I in f)
Ml I'OH J NO.
El'A-4 50/ 3j-7 6-002
7ll I LK AMU SUOTI TLE
Model Validation and Time-Concentration Analysis
of Three Power Plants
J. HLUt'ltNT'i;
G. PlflFCRMING ORGANIZATION COOE
. AUCHOM(S)
Michael T. Mills, Roger W. Stern
J. PEHfORMING ORGANIZATION HT.POHT NO.
T3CA-TR-75-30-G
'. PLRFORMING ORGANIZATION NAME AND ADDRESS
GCA/Technology Division
GCA Corporation
Bedford, Massachusetts 01730
12. SPONSORING AGENCY NAMT AND ADDRESS
OAQPS, Environmental Protection Agency
Research Triangle Park
North Carolina 27711
j. Htf'OUT DATE
December 1975
10.^HOGRAM ELEMENT NO.
2AC 129
11. CONTRACT/GRANT NO.
68-02-1376, Task Order No. 19
13. TYPC OF REPORT AND PERIOD COVERED
Final Report
14. SPONSORING AGENCY COOE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This report presents an analysis of the EPA Single Source Model using S02
concentration and meteorological data collected in the vicinity of three Ohio
Power Plants: J. M. Stuart, Muskingum River, and Philo. The model predicts
the upper percentile of the frequency distribution of 1-hour and 3-hour concen-
trations reasonably well. Concentrations over the remainder of the distribution
are significantly underpredicted, due in part to the errors in the determination
of background concentrations. The second highest 24-hour concentrations tend to
be underpredicted by the model except at the Philo plant, where the model is
less likely to account properly for terrain influences. Also investigated dur-
ing this study were the frequency distributions of peak 1-hour to average 3-hour
and peak 1-hour to average 24-hour concentration rac.ios. Statistics of these
distributions were found to vary little from one plant to the next.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b. IDENTIFIERS/OPEN ENDED TERMS
COSATI Field/Group
IB. DISTRIBUTION STATEMENT
Release unlimited
19. SLCUHITV CLASS (Hut Report)
Unclassified
21. NO. O» PACitS
152
20. SECURITY CLASS (fill! page)
Unclassified
22. PRICE
EPA
i 2<.lQ-\ (9-73)
139
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