NC0000272_Appendix A_20201204

Appendix A
Pigeon River Temperature Measurement and Modeling: 2005-2013
Prepared for:
Evergreen Packaging
175 Main Street
P.O. Box 4000
Canton, NC 28716
www.ever rg eenpackaging com
[phone]

EXECUTIVE SUMMARY
A thermal model was developed, calibrated, and validated to estimate the effect of the
Evergreen Paper Mill on Pigeon River temperatures from Canton USGS (PRM 64.9) to
Hepco USGS (PRM 42.6R). The model was calibrated using river temperature data
collected by University of Tennessee personnel during the summer of 2012 and winter of
2013. Validation of the model was completed by comparing modeled river temperatures
to daily and weekly temperature measurements collected by Evergreen personnel from
2005 — 2013. The validation phase of the modeling shows that the model accurately
predicted the Pigeon River temperatures between the Canton USGS gaging station and
the HEPCO USGS gaging station. The median absolute errors between the model
predicted river temperatures and daily measurements from 2005 - 2013 are 0.6, 0.8, and
1.1 °C for Fiberville, Above Clyde, and Hepco USGS, respectively.
Following validation, a series of model runs was conducted with the mill effluent
temperature set equal to the adjacent river temperature; doing so removed the thermal
loading of the mill from the model without affecting the flow rate of the river.
Comparisons of model runs with the mill turned on and turned off enable a direct
comparison of the estimated temperature change of the Pigeon River. Results of this
comparison show that the median modeled increase in weekly average temperature due to
mill thermal loading is 3.1, 2.5, and 1.5°C at Fiberville, Above Clyde, and Hepco USGS,
respectively.
2

A numerical thermal plume mixing model, CORMIX, was run to simulate the thermal
plume mixing into the Pigeon River between the mill outfall and the Fiberville Bridge.
These modeled results were compared to University of Tennessee's measured thermal
cross sections collected at the railroad bridge just below the mill outfall and also at the
Fiberville Bridge measured on two different days. The modeled results were also
compared to aerial photographs available on Google Earth. During low Pigeon River
flowrates, the thermal plume from the outfall mixes rapidly across the majority of the
river with a small remaining temperature difference (-0.5 °C) from side to side at the
Fiberville Bridge. During medium Pigeon River flowrates, the thermal plume mixes into
the Pigeon River more slowly, and the remaining differential temperature is larger from
side to side at Fiberville. And during large flowrates, it appears that the far right side of
the Pigeon River, opposite of the outfall, remains at near ambient temperatures at the
Fiberville Bridge.

INTRODUCTION
A numerical thermal model was developed for the Pigeon River from above the mill
(PRM 64.9) to the upstream extent of Waterville Reservoir (PRM 42.6R). The model was
calibrated using approximately four months of measured river temperature data: two
months collected in the summer of 2012 and another two months collected during the
winter of 2013. Nineteen thermographs were deployed in the Pigeon River from above
the discharge outfall of the Evergreen Paper mill in Canton, NC (PRM 64.9) down to
Blufton, TN (PRM 19.3R). Five thermographs were placed in each of the five tributaries
flowing into the Pigeon River, two thermographs were placed in a nearby reference
stream, the Swannanoa River, and a last thermograph was deployed within the mill
outfall. Hourly temperature measurements were collected from these thermographs for
the two -month summer and two -month winter data collection periods. Using these
temperature data, a numerical thermal model of the Pigeon River was calibrated. This
calibrated model was then validated against daily temperature measurements of the
Pigeon River collected from 2005 — 2013. Finally, the validated model was used to
determine how much the mill increased the temperature of the Pigeon River due to its
thermal loading for the same period.
To help determine how quickly the thermal plume mixes into the Pigeon River after
being released from the outfall, 2-D thermal cross -sections were measured at the Railroad
Bridge (PRM 63.2) and at the Fiberville Bridge (PRM 63), both below the outfall (PRM
63.3). Additionally, CORMIX, a USEPA supported 3-D plume mixing model, was run
for select times corresponding to the dates of the 2-D thermal cross section measurements
4

and when aerial photographs of the site were available. Analyzing the results of the
thermal cross sections and the 3-D thermal plume modeling enabled insight into how
readily the thermal plumes mixes into the Pigeon River.
Data Collection
Thermographs
The HOBO® Pendant UA-001 thermograph was chosen for the temperature monitoring
of the Pigeon River, tributaries, and reference sites. It is housed in a polypropylene case
(58 x 33 x 23 mm) that is waterproof to a depth of 30 m. The range of the thermograph
temperature measurement is -20°C to 70°C with a resolution of 0.1°C, and the accuracy is
approximately 0.5°C, within the range of these river measurements. The temperature
drift of the sensor is less than 0.1 °C per year and the time accuracy is within 1 minute per
month. The 10-bit resolution thermograph can record up to 6,500 temperature events.
The thermograph setup and data retrieval is performed using a coupler and optical base
station with USB computer interface. The response time of the thermograph to water
temperature change (90%) is about 5 minutes. While the thermograph is deployed, the
typical life of the replaceable battery is one year.
Thermograph Deploy
Twenty-seven thermographs were deployed in the Pigeon River from above the discharge
outfall of the Evergreen Paper mill in Canton, NC (PRM 64.55R) down to Blufton, TN
(PRM 19.3R), the tributaries that feed the Pigeon River, the mill outfall and the
Swannanoa River. The thermographs were deployed by affixing them to 1.6-mm (1/16-
5

in.) galvanized or stainless steel wire rope. The rope was also tethered (near the sensor)
to a steel weight with a mass of approximately 2.25 kg (5 lbm). The other end of the wire
rope was swaged to a stationary object (e.g., tree, railing, etc.) above or along size the
river or tributary. The data collection start time and collection interval was set through a
USB computer interface before the thermograph was deployed into the river or tributary.
Although the thermographs had enough internal memory for the entire deployment
period, intermittent data collections were performed to guard against the risk of data loss.
During the summer 2012 thermal measurement period, two intermittent, and then a final
data collection were performed. During the winter 2013 thermal measurement period,
only a final data collection was performed following the entire two -month period.
Although two intermittent winter sampling dates were scheduled, foul weather on the
scheduled dates made the retrievals too dangerous for the University of Tennessee
personnel to proceed. During the summer collection period the data collection efficacy
was excellent, with only a few lost/stolen sensors and only for a few weeks of the two -
month collection period. During the winter collection period, a total of four sensors (of
the 27 deployed) were lost or stolen.
Thermograph Deployment Locations
The location name, river mile, and longitude and latitude of the bankside-tethered
location for each thermograph are presented in the Table 1. The thermograph locations
named as creeks were monitored within said creeks prior to their confluence with the
Pigeon River. Figures 1-9 show the location of each thermograph location plotted on a
Google earth image.
Table 1. Name, river mile, longitude and latitude, river of thermograph
deployment locations (L = left, C = center, and R = right side of the river),
0

and success of collecting data (FULL = all data collected, PART = some
data collected, NONE = no data collected).
Name
River Mile,
Longitude
Latitude
Summer
12' Data
Winter
13' Data
Above Mill
PRM 64.55R
82.841750°
35.531000°
FULL
NONE2
Just Above Dam
PRM 63.35R
82.843064'
35.533714'
FULL
NONE3
Mill Outfall
PRM 63.30L
82,845349'
35.535631°
FULL
FULL
Above RR Bridge
PRM 63.25R
82.845100'
35.536583'
FULL
FULL
RR Bridge Left
PRM 63.2L
82.845354°
35.537261°
FULL
FULL
RR Bridge Center
PRM 63.2C
82.845205°
35.537376'
FULL
NONE2
RR Bridge Right
PRM 63.2R
82.845080°
35,537464'
FULL
FULL
Camp Creek
PRM 63.15T
82.844916°
35.537943'
FULL
FULL
Below RR Bridge
PRM 63.1R
82.845117°
35.538817'
FULL
FULL
Fiberville Bridge
PRM 63R
82.846250°
35.541550'
FULL
FULL
Beaver Dam Creek
PRM 62.9T
82.845833°
35.540917'
FULL
FULL
Pump Station
PRM 62.511
82.850567'
35.546617°
FULL
FULL
DO Station
PRM 61R
82.863233°
35,5434830
FULL
PART4
Above Clyde
PRM 59R
82.892083°
35.542700°
FULL
FULL
Hyder Mt.
PRM 55.5L
82.939283°
35.548817°
FULL
FULL
Richland Creek
PRM 54.9T
82.9458830
35,548217'
FULL
FULL
River View
PRM 53.513
82,953967'
35.561917*
FULL
FULL
Crabtree Creek
PRM 49.8T
82.950850°
35.600583'
PARTz
FULL
Jonathan's Creek
PRM 46T
83.005867'
35.626333°
FULL
FULL
Hepco USGS/Gage
PRM 45.1L
82.990000°
35.635000°
FULL
FULL
Fine's Creek
PRM 42.7T
82.992942'
35.665415'
FULL
FULL
Hepco Bridge
PRM 42.613
82.994752°
35.666014'
FULL
FULL
Waterville Bridge
PRM 25.2L
83.112267'
35,783950'
FULL
NONE2
Trail Hollow
PRM 22L
83.145167°
35.812083'
PARTz
FULL
Blufton
PRM 19.311
83.177550'
35.817000°
FULL
NONE2
Warren Wilson
College
SRM 11.3L
82.444067°
35.607800'
FULL
FULL
Exit 50 - Interstate
40
SRM 1.6L
82.544050'
35.568733'
FULL
FULL
PRM = Pigeon River Mile;
SRM = Swannanoa River Mile (Reference Stream);
L = Left side of River (facing downstream);
C = Center of River;
R = Right side of river;
0 = Sensor located in mill outfall prior to effluent entering the Pigeon River
T = Sensor located in tributary prior to tributary entering the Pigeon River
2 -The sensor was not present upon attempted retrieval.
3 -The sensor could not be retrieved due to being lodged under debris in the bed of the river.
7

4 — The sensor was errantly set to log every minute instead of every hour and filled up the thermograph's
internal memory within several days.
Thermograph Data Description
All the thermograph data collected by University of Tennessee personnel are presented in
Figures 8-44. Figures 10-29 represent data collected from the summer of 2012, and
Figures 30-46 represent data collected from the winter of 2013. Some of these figures
will occasionally show where a thermograph was removed from the river: either by a
high flow event or an errant person. A good example of this is shown in Figure 31 where
the PRM 63.25R sensor was washed up high on the bank in early February 2013.
Following this point in time the sensor is mostly responding to the air temperature and
not the river temperature. The Camp Creek Thermographs (Figures 14 and 33) also show
very spikey behavior, which is due to the very shallow depth of the creek making full
submersion of the sensor difficult.
The thermographs in the vicinity of the mill demonstrate the complex mixing of the
thermal discharge across the river at different river flows. Figures 12 and 30 show the
temperatures of the mill outfall (PRM 63.3OL) located on the left -hand -side (LHS) of the
river facing downstream. The outfall temperatures were fairly consistent over short to
moderate durations and were cooler during the winter season. Figures 11 and 31 present
data for PRM 63.35R (located above the outfall) and PRM 63.25R (located just below the
outfall) on the right -hand -side (RHS) of the river (Figure 1). By comparing the black line
(PRM 63.35R) to the orange dots (PRM 63.25R) it is clear that much of time during the
summer monitoring (Figure 11), particularly in the first 2/3rds of the summer monitoring,
that PRM 63.25R showed approximately half of its hourly temperatures were equal to

those upstream of the outfall (i.e., ambient conditions). The other approximate half of the
temperature measurements was elevated, but not as elevated as the temperatures at the
next station, (PRM 63.2L,C,R Figures 13 and 32). This is consistent with a finding that
the thermal plume had crossed over to the RHS at PRM 63.25R during approximately
half of the hourly measurements, but was not yet fully mixed on the RHS causing the
RHS to still show lower temperatures than downstream at all three thermographs (PRM
63.2L,C,R). When comparing the three PRM 63.2L,C,R thermographs, the Left
thermograph (on the same side as the outfall) is almost always the warmest, the Center
thermograph generally has the same temperature as the Left or slightly cooler (and during
high flow events is sometimes warmer than the Left indicating the plume becomes more
centered, and the Right thermograph is almost always cooler indicating the thermal
plume has not fully mixed by the time is reaches PRM 63.2. During high flow events,
PRM 63.2R appears to still show ambient temperatures, meaning the thermal plume does
not extend across to the right side of the river at PRM 63.2R during high flow events
(e.g., compare PRM 63.35R to PRM 63.2R in late July; they both dip to just below 20 C.
Similar occurrences are present in early July).
Further downstream the same complex cross sectional pattern continues. Figures 15 and
34 present the measured temperatures at Below RR Bridge (PRM 63.1T). This
thermograph and the one just downstream (Figures 16 and 35, Fiberville, PRM 630)
were located on the right side of the river. During the summer measurements the median
river temperature increased by 0.1 C from PRM 63.1 R to PRM 63R, and during the
winter measurement the median temperature increased by 0.4 C. This increase of
OJ

temperature following the addition of warm water from the outfall is consistent with the
thermal plume mixing from the original left -hand -side of the river at the outfall to the
right -hand -side of the river further downstream, During the summer temperature
measurements, river flow rates were low, which enabled the plume to mix more readily
leaving a small amount of mixing taking place between PRM 63.1R and PRM 63R.
During the winter higher flowrates, greater amounts of mixing were still occurring
between PRM 63.1R and PRM 63R.
Tributaries generally added cooler water to the mainstem. Figures 14 and 33 show the
temperatures for Camp Creek (entering the Pigeon River at PRM 63.15T), Beaver Dam
Creek (entering at PRM 62.9T), and Richland Creek (entering at PRM 54.9T). Likewise,
Figures 22 and 41 show the temperatures of Crabtree Creek (entering at PRM 49.8T),
Johnathan's Creek (entering at PRM 46T), and Fine's Creek (entering at PRM 42.7T).
Generally, the summer temperatures of these six creeks are cooler than the ambient
summer Pigeon River temperature measured at PRM 64.55R, upstream of the outfall.
The increased temperatures from the outfall further decrease as one moves down the
Pigeon River. Figures 18 — 23 and 37 — 43 show the thermographs between the DO
station (PRM 61 R) and the Hepco Bridge (PRM 42.6R). Figures 25, 26, 27, and 44
present the thermographs below Waterville Lake including: Waterville Bridge (PRM
25.2L), Trial Hollow (PRM 22L), and Blufton (PRM 19,3R).
10

The Swannanoa River was chosen as a reference stream for comparison of biologic
results of the Pigeon River. In an endeavor to measure the thermal similarities or thermal
differences between the Pigeon River and the Swannanoa River, the two thermograph
locations on the Swannanoa River shown in Figure 9 were measured by UT personnel.
Figures 28, 29, 45, and 46 present the thermographs from the Swannanoa River at
Warren Wilson College (SRM 11.3L) and Exit 50 (SRM 1.6L). A comparison of the
measured temperatures at these two reference locations to those measured upstream of
the mill at Canton USGS is presented in Figures 47 and 48. The USGS began publishing
hourly temperature measurements at their Canton USGS Station in July 2012 making this
hourly comparison possible. SRM 11.3 was on average 1.1 C warmer and SRM 1.6 was
on average 1.2 C warmer than the Pigeon River during the 4 months of collected data
during the summer of 2012 and winter of 2013. The Swannanoa River has thermal
characteristics very similar to that of the Pigeon River upstream of the outfall.
Data Provided by Evergreen
A meteorological data file was supplied by Evergreen containing hourly measurements of
air temperature at 2-m height; wind speed at 10-m height; and solar radiation, These
data covered the modeling period 2005 through 2013. An additional data file was
supplied by Evergreen that included: daily flowrate (USGS source) and daily
temperature (Evergreen source) at the Canton USGS gage site; hourly flowrate and
hourly temperature of the mill outfall (Evergreen source); daily temperature
measurements at Fiberville (PRM 63R) and Above Clyde (PRM 59R) (Evergreen
source); daily flow measurements from Hepco USGS gage (USGS source); and
11

approximately weekly temperature measurements from Hepco USGS gage (Evergreen
source). The flow measurements at the Canton USGS and Hepco USGS gaging stations
were originally measured by the USGS and are daily averages. The temperature
measurements collected by Evergreen personnel were made between approximately
0900-1100 each day. Tables 2-6 provide the temperature and flow statistics at the Canton
USGS Gage, Mill Outfall, and Hepco USGS Gage. The daily and weekly temperature
measurements collected by Evergreen personnel were measured with a Hach HQ 30d
combination temperature and DO meter. The meter is calibrated annually against a
certified source.
12

Table 2 . Flow Statistics for Canton USGS
Percentile
Canton USGS
Discharge m3 s-1)
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
1
3.68
3.60 1
4.98
4.50
2.86
1.81
1.47
1.08
1.39
1.42
1.56
2.04
5
4.05
4.05
5.38
4.87
3.43
2.04
1.56
1.30
1.47
1,50
1.70
2.44
10
4.56
4.45
5.69
5.10
3.82
2.27
1.70
1.36
1.50
1.56
1.87
2.55
15
4.87
4.87
5.95
5.37
4.16
2.46
1.84
1,44
1.56
1.64
2.04
2.94
20
5.44
5,27
6.23
5.58
4.28
2.72
2.10
1.67
1.61
1.70
2.24
3.77
25
6.14
5.69
6.60
5.94
4.45
2.92
2.32
1.81
1.70
1.81
2.35
4.45
30
6.71
6.23
7.22
6.43
4.67
3.09
2.44
1,93
1.81
2.04
2.63
5.10
35
7.53
6.68
7.73
6.71
4.87
3.26
2.58
1.98
2.04
2.41
2.78
5,92
40
7.87
7.05
8.13
7.14
5.10
3.40
2.69
2.04
2.35
2.63
2.86
7.53
45
8.50
7.59
8.67
7.59
5.49
3.54
2.78
2,18
2.55
2.92
3.09
8.18
50
9.30
8.13
9.34
8.04
6.03
3.77
2.86
2.29
2.72
3.23
3.31
8.83
55
10.4
8.67
10.34
8.61
6.43
3.96
3.00
2.44
2.92
3.54
3.48
9.57
60
11.5
9.71
11.16
9.11
6.85
4.16
3.14
2.58
3.26
3.77
3.96
10.2
65
13.3
10.5
11.9
9.71
7.14
4.38
3.31
2.83
3.68
4.22
4.64
11.0
70
14.4
11.4
12.8
10.2
7.82
4.73
3.43
3.09
4.53
4,70
5.30
12.1
75
14.9
12.4
13.9
11.0
8.61
5.10
3.60
3.40
5.10
5.30
5.92
13.2
80
16.1
13.6
15.5
11.6
9.34
5.66
3.87
3.58
5.89
5,92
7.53
14.6
85
18.0
15.5
17.4
12.8
10.4
6.35
4.16
4.16
6,99
6.60
9.85
16.9
90
21.8
17.9
20.1
14.7
12.4
7.59
4.79
4.98
9.27
7.82
14.1
19.5
95
31.7
22.6
25.6
18.7
15.7
10.2
6.14
6.30
15.7
10.6
21.5
25.7
99
94.0
35A
48.1
32.7
22.4
14.9
12.2
15.1
63.6
22,5
53.5
57.2
Mean
15.0
10.5
12.5
9.83
7.44
4.68
3,43
3.21
6.74
4.66
7.44
11.6
N
5952
5424
5952
5040
5208
5040
5208
5208
5040
5616
5760
5952
Max
242
59
219
143
44
25
43
309
201
129
326
176
Min
3.00
3.17
4.90
4.36
2.72
1.76
1.36
1.05
1.36
1.36
1.56
1.98
13

i aaie s. i emDerature stansncs for t-anton unun
Percentile
Canton USGS Temperature (°C)
(%)
JAN
FEB
I MAR
APR I
MAY
JUN
JUL I
AUG I
SEP
OCT
NOV
DEC
1
0.11
0.83
1.54
2.14
2.74
3.22
3.59
3.96
4.28
4.57
4.87
5.18
5.50
5.86
6.27
6.68
7.19
7.85
8.62
9.40
11.0
5.00
5952
12.3
-0.26
0.72
1.74
2.30
2.79
3.20
3.61
4.04
4.43
4.80
5.11
5.46
5.74
6.04
6,34
6.63
6.93
7.26
7.67
8.16
8.82
10.2
5.33
5424
11.1
-0.18
2.22
3.76
4.83
5.69
6.26
6.74
7.16
7.50
7.81
8.14
8.51
8.91
9.34
9.77
10.2
10.5
11.1
11.7
12.5
14.3
15.7
8.68
5952
16.4
0.63
7,22
8.59
9.65
10.3
10.7
11.2
11.6
11.9
12.2
12.6
12.9
13.2
13.6
13.9
14.3
14.6
15.0
15.4
15.8
16.4
17.2
12.8
5040
18.2
5.90
11.7
13.1
14.3
14.7
15.1
15.4
15.7
16.0
16.2
16.5
16.8
17.1
17.4
17.7
18.0
18.3
18.7
19.0
19.5
20.2
21.7
16.8
5208
23.0
9.98
16A
17.6
18.4
18.9
19.3
19.6
20.0
20.3
20.6
20.8
21.0
21.2
21.4
21.6
21.8
22.0
22.3
22.5
22.8
23.3
24.0
20.8
5040
25.0
15.4
19.0
19.8
20.3
20.8
21.2
21.4
21.7
21.9
22.2
22.4
22.6
22.7
22.9
23.1
23.3
23.5
23.8
24.1
24.4
24.9
25.7
22.5
5208
26.8
18.4
19.1
20.2
20.7
21.1
21.4
21.6
21.9
22.1
22.3
22.5
22.7
22.9
23.1
23.4
23.6
23.8
24.1
24.4
24.7
25.1
25.9
22.7
5208
27.5
17.4
14.3
15.9
16.6
17.1
17.5
17.8
18.1
18.4
18.7
19.0
19.3
19.7
20.0
20.3
20.6
21.0
21.3
21.8
22.3
22.9
23.8
19.4
5040
25.0
13.0
7.17
8.99
10.1
11.0
11.7
12.2
12.7
13.2
13.5
13.9
14.2
14.5
14.8
15.1
15 A
15.7
16.0
16.4
16.8
17.6
19.8
13.9
5208
21.0
5.70
3.48
5.08
5.92
6.46
6.88
7.21
7.61
7.96
8.30
8,62
8.94
9.21
9.48
9.79
10.0
10.3
10.6
11.0
11.5
12.2
14.0
8.79
5760
15.4
1.86
0.18
1.63
2.91
3.56
4.02
4.41
4.69
4.99
5.30
5.59
5.94
6.28
6.64
6.97
7.3
7.8
8.2
8.8
9.4
10.2
11.5
6,03
5952
12.6
-0.35
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
99
Mean
N
Max
Min
14

Table 4. Flow statistics for the mill outfall.
Percentile
Mill Outfall Discharge (m3 s-I)
(%)
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
1
0.94
0.93
0.94
0.86
0.86
0.96
0.94
0.90
0,91
0.84
0.92
0.95
5
1.00
1.00
0.99
0.97
0.97
1.02
1.00
0.98
0.99
0.97
0.98
1.02
10
1,03
1.03
1.02
1.02
1.01
1.05
1.03
1.03
1.02
1.01
1.01
1.05
15
1.05
1.05
1.04
1.05
1.04
1.07
1.06
1.05
1.04
1.04
1.03
1.07
20
1.06
1.07
1.06
1.06
1.05
1.08
1.07
1.07
1.06
1,06
1.05
1.08
25
1.08
1.08
1.07
1.08
1.07
1.10
1,09
1.08
1.07
1.07
1.06
1.09
30
1.09
1.09
1.08
1.09
1.09
1.11
1.10
1.09
1.08
1.09
1.07
1.10
35
1.10
1.10
1.10
1.10
1.10
1.12
1.11
1.10
1.09
1.10
1.09
1.11
40
1.11
1 1.11
1,11
1,11
1.11
1.13
1.12
1.11
1.10
1.11
1.10
1.12
45
1.12
1,12
1,12
1,12
1.13
1.14
1.13
1.12
1.11
1.12
1.11
1.13
50
1,13
1.13
1.13
1.14
1.14
1.15
1.14
1.14
1.12
1.13
1.12
1.14
55
1.14
1.14
1.15
1.15
1.15
1.16
1.15
1.15
1.13
1.15
1.14
1.15
60
1,15
1.15
1.16
1.16
1.16
1.17
1.16
1.16
1.14
1.16
1,15
1.16
65
1.16
1.16
1.17
1.17
1.18
1.18
1.17
1.17
1.15
1.17
1.16
1.17
70
1.17
1.17
1.19
1.18
1.19
1,19
1.19
1.18
1.16
1.18
1.18
1.18
75
1.19
1.19
1.21
1,20
1.21
1.21
1,20
1.19
1.18
1.19
1.20
1.19
80
1.20
1.20
1.22
1.21
1.23
1.22
1.22
1.21
1.19
1,21
1.23
1.21
85
1.23
1.22
1.24
1.23
1.25
1.24
1.24
1.22
1.20
1.23
1.26
1.23
90
1.25
1.24
1.28
1.26
1.28
1.26
1.26
1.25
1.23
1.26
1.26
1.25
95
1.31
1.28
1.32
1.30
1.33
1.30
1.30
1.29
1.26
1.29
1.28
1.29
99
1.43
1.37
1.43
1.47
2.03
1,42
1.45
1.44
1.39
1.40
1.42
1,40
Mean
1.14
1.14
1.14
1.14
1.17
1.16
1.15
1.14
1.13
1.13
1.13
1.15
N
5952
5424
5952
5040
5208
5040
5208
5208
5040
5616
5760
5952
Max
1.88
1.65
1.71
1.85
2.06
1.85
1.92
2,09
1.78
1.93
1.71
1.74
Min
1 0.66
0.77
0.57
0.60
0.57
0.56
0.61
0.72
0.14
0.61
0.69
0.74
15

Table 5. Temperature statistics for the mill outfall.
Percentile
Mill Outfall Temperature
(°C)
(%)
JAN
FEB
MAR
APR
MAY
JUN
JUL
I AUG
SEP
I OCT
NOV
DEC
1
22.2
23.0
23.7
24.2
24.5
24.8
25.2
25.4
25.7
26.0
26.4
26.7
27.0
27.3
27.7
28.1
28.6
29.2
29.9
31.7
34.0
26.6
5952
37.1
21.7
22.8
23.7
24.1
24.7
25.1
25.5
25.8
26.1
26.4
26.7
27.0
27.3
27.5
27.8
28.1
28.6
29.1
29.7
31.4
33.3
34.6
27.3
5424
35.1
22.2
24.6
25.4
26.0
26.4
26.6
26.9
27.1
27.4
27.7
28.1
28.4
28.8
29.2
29.5
29.9
30.4
31.1
32.0
33.1
34.9
36.2
29.0
5936
38.2
24.1
23.4
25.9
26.7
27.4
28.2
28.7
29.3
29.6
29.9
30.3
30.5
30.7
30.9
31.2
31.6
32.0
32.4
32.9
33.9
34.9
36.9
30.3
5040
43.6
21.5
20.3
26.8
28.0
28.7
29.2
29.6
29.9
30.2
30.5
30.8
31.2
31.6
32.1
32.7
33.1
33.6
34.0
34.6
36.0
37.0
38.6
31.5
5208
43.9
17.3
28.6
29.3
30.0
30.3
30.7
31.0
31.3
31.6
31.9
32.1
32.3
32.5
32.8
33.0
33.3
33.5
34.0
35.0
37.3
38.1
39.1
32.7
5040
42.8
15.9
26.0
29.1
29.7
30.2
30.5
30.7
30.9
31.1
31.4
31.9
32.3
32.7
33.0
33.3
33.5
33.7
33.9
34.1
34.4
35.2
36.6
32.2
5208
48.0
24.7
29.6
30.5
30.9
31.2
31.5
31.9
32.2
32.4
32.7
32.9
33.2
33.4
33.6
33.8
34.0
34.2
34.3
34.6
34.9
35.5
36.1
33.0
5208
46.8
12.3
25.9
26.8
27.9
28.6
29.1
29.7
30.2
30.6
31.1
31.3
31.6
31.8
32.0
32.3
32.7
33.0
33.4
34.3
35.2
35.9
36.7
31.4
5040
37.5
25.1
24.1
25A
26.1
26.5
26.9
27.2
27.5
27.8
28.1
28.3
28.6
29.0
29.4
29.7
29.9
30.4
30.8
31.2
31.8
33.0
33.9
28.8
5208
34.6
22.0
22.9
23.9
24.5
25.0
25.3
25.6
25.9
26.2
26.6
26.8
27.0
27.2
27.4
27.6
27.8
28.1
28.4
28.7
29.4
30.1
31.8
27.0
5760
32.5
22.0
21.7
23.0
23.9
24.4
24.8
25.2
25.5
25.7
26.0
26.3
26.6
26.8
27.1
27.3
27.6
27.9
28.4
28.8
29.4
30.9
32.6
26.6
5952
34.3
21.3
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
99
Mean
N
Max
Min
16

Table 6. Flow statistics for Hepco USGS
Percentile
Hepco USGS Dischar a m3 s"1
(%)
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
1
8.92
9.09
11.5
9.88
7.36
4.19
3.09
1.90
2.94
2.83
3.23
5.32
5
10.3
10.8
12.1
11.8
8.16
4.84
3.79
2.49
3.11
2.94
3.60
5.92
10
10.9
12.1
12.6
12.6
9.00
5.75
4.33
3.00
3.37
3.03
4.33
6.54
15
11.7
12.1
13.5
13.0
9.77
6.34
5.01
3.45
3.54
3.34
4.79
7.45
20
12.6
12.5
14.6
13.5
10.6
6.80
5.41
4.05
3.71
3.99
5.41
10.0
25
13.4
13.3
15.2
13.9
11.0
7.48
5.83
4.42
3.91
4.28
5.92
11.0
30
14.6
14.1
16.1
14.5
11.9
7.98
6.09
4.79
4.05
4.56
6.34
11.8
35
16.1
15.3
17.3
15.2
12.5
8.38
6.17
5.01
4.42
5,01
6.74
13.2
40
17.4
16.1
18.6
15.8
13.3
8.89
6.43
5.24
4.93
5.75
6.99
15.2
45
18.5
17.1
19.7
16.5
14.0
9.32
6.71
5.58
5,24
6.60
7,36
16.4
50
19.7
18.4
20.9
17.3
14.8
9.54
6.97
5.83
5.69
7.91
7.84
17.3
55
21.1
19.7
22.1
18.2
15.5
9.91
7.16
6.34
6.26
8.52
8.35
18.2
60
23.0
20.9
23.9
19.1
16.4
10.4
7.39
6.80
6.82
9.15
9.12
19.4
65
25.5
23.2
25.3
19.9
17.0
10.8
7.67
7.16
8.16
9.66
10.4
20.8
70
27.7
24.9
26.7
20.9
17.4
11.3
8.04
7.59
9.46
10.4
11.7
22.6
75
30.6
27.3
28.3
21.8
18.4
11.9
8.47
8.16
11.1
11.9
133
25.1
80
34.0
30.0
30.6
22.9
19.6
12.7
9.00
8.92
12.8
13.7
15.9
27.3
85
37.7
34.4
33.4
25.0
21.3
13.5
9.68
10,1
15.3
15.0
21.1
31.1
90
45.3
39.1
36.2
28.6
23.8
15.3
11.1
11.7
20.5
17.0
27.3
36.8
95
69.8
47.2
45.0
34.8
29.4
17.8
14.0
14.6
29.5
21.1
39.1
50.0
99
176
73.6
84.4
62.8
44.4
28.0
21.6
30.3
87.7
44.9
101
112
Mean
30.7
23.4
25.1
20.4
16.5
10.5
7.8
7.5
12.0
10.1
15.2
23.0
N
5952
5424
5952
5040
5208
5040
5208
5208
5040
5616
5760
5952
Max
362
116
235
172
63.1
73.3
51.3
317
292
171
320
238
Min
8.38
8.58
10.7
9.66
6,91
3.85
2.86
1.73
2.78
2.55
3.03
5.10
Longitudinal 1-D Thermal Model Development
A conceptual thermal model for the Pigeon River was developed (Canton USGS PRM
64,9 to Hepco USGS PRM 42.5) that included thermal contributions from tributaries, the
17

mill outfall, riverbed heat exchange, river surface heat exchange, and the upstream
temperature. A conceptual description of the model is shown in Flowchart 1.
SURFACE
UTARIES HEAT
EXCHANGE
RIVER RIVER SECTION (n)
SECTION
(n-1) (PRM 64.9 to PRM 42.6)
BED
HEAT
EXCHANGE
MILL
OUTFALL
RIVER
SECTION
(n+1)
Flowchart 1. Conceptual thermal model of the Pigeon River for PRM 64.9 to
PRM 42.6.
The temperature of the Pigeon River was modeled as 1-1) from PRM 64.9 to PRM 42.6
from the fall of 2005 through the spring of 2013 and included the effects of mill thermal
loading and environmental conditions. The model includes the assumption that the
temperature throughout the cross section of the river is uniform and any additional water
(from a tributary or the mill outfall) is immediately mixed upon entering the river. These
18

are very common assumptions for modeling the effect of waste heat on natural river
systems.
Following Caissie et al. (2005), a thermal model was developed very similar to the
previous 2001 Pigeon River model (EA Eng. 2001):
where,
t = time [s]
TR = temperature of the river at a given location [°C]
A = cross section area of stream [m2]
x = distance downstream [m]
Qr = flow rate of the river [m3 s-1]
B= specific heat of water [4.19 x 10-3 MJ kg-' °C-']
p = density of water [1000 kg ni3 1
y = depth of the river [m]
HT= total heat flux to the river [W m"Z]
HT = HB + Hs + HTR
HB = heat flux through the bed of the river [W m-z]
Hs = heat flux through the surface of the river [W m z]
HTR = heat flux from tributaries and mill outfall [W m-']
HB and Hs were estimated by multiplying a thermal exchange coefficient by the
difference in temperature that is driving the heat flow.
(2)
19

where
H8 = K13(7'30,m — TR )
Hs = Ks (TI, — Tr?)
KB = bed thermal exchange coefficient [W m-2 °C -I]
T30c,,, = temperature of the bed at a depth of 30 cm [°C]
KS= surface thermal exchange coefficient [W m-2 °C -I]
TE = equilibrium temperature of the river [°C]
(3)
(4)
TE is the equilibrium temperature, or the instantaneous temperature that the river would
ultimately achieve if conditions stayed constant. Equation 1 was solved numerically at a
1-hr time interval and a 161-in (0.1 mi) length interval from the fall of 2005 through the
spring of 2013. The parameters within the model were calibrated using the extensive
thermograph dataset collected by University of Tennessee personnel during the summer
of 2012 and winter of 2013 shown in Figures 10 - 24 and 30 — 43.
The width, height, and velocity of each reach of the Pigeon River as a function of QR
were obtained from a previous report (Synoptic Survey of Physical and Biological
Condition of the Pigeon River in the Vicinity of Champion International Canton Mill)
conducted by EA Engineering, Science, and Technology, Inc. in 1987 (EA Eng., 1987).
They fit the geometry of the channel to three power -law functions:
Velocity [ft s 1] = al * Qbl (5)
Depth [ft] = a2 * Qb2 (6)
Width [ft] = a3 * Qb3 (7)
20

Table 7 provides the values for the variables, a and b used in Eqs. 5-7 for each reach of
the Pigeon River.
21

Table 7. Velocity, depth, and width coefficients for the Pigeon River used in
equations 5-7 (EA, 1987).
Reach
River PRM Mile
Velocity
Depth
Width
Top
Bottom
al
bl
a2
b2
a3
b3
1
64.7
63.2
62.5
62.0
61.2
59.9
58.0
57.3
55.3
54.9
53.7
52.8
51.5
49.7
48.5
48.2
47.0
46.0
45.5
63.2
62.5
62.0
61.2
59.9
58.0
57.3
55.3
54.9
53.7
52.8
51.5
49.7
48.5
48.2
47.0
46.0
45.5
42.5
0.157
0.242
0.563
0.252
0.192
0.247
0.221
0.241
0.196
0.327
0.249
0.202
0.221
0.207
0.814
0.247
0.256
0.255
0.233
0.196
0.275
0.253
0.317
0.221
0.252
0.255
0.307
0.331
0.216
0.355
0.214
0.342
0.348
0.095
0.362
0.346
0.376
0.312
0.570
0.183
0.246
0.103
0.393
0.252
0.242
0.118
0.086
0.443
0.089
0.448
0.081
0.075
3.99
0.062
0.076
0.051
0.121
0.294
0.412
0.380
0.476
0.331
0.378
0.382
0.461
0.496
0.323
0.503
0.321
0.513
0.522
0.142
0.543
0.519
0.564
0.469
11.17
22.6
7.23
38.5
13.2
16.06
18.7
35.1
59.2
6.89
45.4
10.1
56.0
64.5
0.308
65.7
51.3
76.5
35.6
0.510
0.313
0.367
0.207
0.448
0.370
0.363
0.232
0.173
0.461
0.162
0.465
0.145
0.130
0.763
0.094
0.134
0,060
0.219
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
22

Relative flowrates for tributaries feeding into the Pigeon River were calculated in a
previous report (EA 1987) and are given as a partitioning coefficients: each describing
the relative portion of increased flow between the Canton and Hepco USGS gaging
stations (Table 8). These data show that 81.2% of the increase of flow between Canton
USGS and Hepco USGS is attributed to tributaries. The remaining 18.8% of the
increased flow was attributed to baseflow and was evenly divided between each model
node between the Canton USGS to Hepco USGS gaging stations, Table 8 provides the
Partitioning Coefficient for each tributary.
Table 8. Flow Rate Partitioning Coefficients for Tributaries
Location River Mile Partitioning Coefficient
Beaverdam Creek (PRM 62.9T) 62.8 0.052
Richland Creek (PRM 54.9T) 54.9 0.315
Crabtree Creek (PRM 49.8T) 49.7 0.123
Jonathan's Creels (PRM 46T) 1 46.0 0,323
Fine's Creek (PRM 42.7T) 1 42.7 0,073
At each time step, the flowrate for each node within the model was calculated based on
the Canton and Hepco USGS gaging station measurements, the predicted partitioning
coefficients, and baseflow by
Q;+i = Q; + (P; + 0.188 / n) * (Qh-Q�)
where,
(8)
23

Q, = Q, = Pigeon River flow at Canton USGS
Q, = Qh = Pigeon River Flow at Hepco USGS
P; = Partitioning Coefficient for a given model node (only present at nodes with
tributaries shown in Table 7)
i = a node (downstream) of the model
n = 224 = number of nodes between Canton USGS (PRM 64.9) and Hepco Bridge
(PRM 42.6)
from model node i = I to i = n.
Additionally, the appropriate amount of modeled water was removed from the Pigeon
River at the mill intake, and replaced at the mill outfall. These amounts varied on an
hourly basis and were provided by Evergreen personnel.
Temperatures were assigned to the tributaries for the entire nine year period by first
comparing the measured tributary temperatures to the Canton USGS temperatures
collected during the summer 2012 and winter 2013 data collection. In almost all cases
the tributary temperatures were within two degrees of Canton USGS temperature.
Simple corrections were applied to slightly modify the tributary temperatures from the
Canton USGS temperature, to provide a more accurate input for the thermal model.
24

MODEL CALIBRATION
The longitudinal 1-D numerical model was calibrated using temperature data collected by
University of Tennessee personnel from the Pigeon River and its tributaries. During the
model calibration, T30,,,, KB, and KS were optimized to ensure a good fit of the modeled
temperatures to those collected by University of Tennessee personnel.
The first two parameters, T3o,,,,, KB, primarily control the amount of diurnal temperature
oscillation. HB is commonly neglected if modeling on a daily or longer basis (Morin and
Couillard, 1990) but was included in this model to show a more accurate representation
of the diurnal cycle. As KB increases, the diurnal variation decreases and visa versa. The
effect of a large KB is to increase the rate at which energy is added and removed through
the streambed during short-term oscillations and acts as a buffer to daily temperature
oscillations.
Equilibrium temperature (TE) was set as the USGS Canton Temperature at a given time,
and KS was used to optimize the fit between measured and modeled temperatures.
Although the value of KS can be predicted (Edinger et al., 1974), such predictions often
do not perform well (Rutherford et al., 1993). The difficulty of deterministically
calculating variables dependent on meteorological conditions is that the actual
meteorological conditions at the stream are not known and vary significantly in time and
space.
25

Figures 49 - 54 present a comparison of the calibrated model (black line) to the UT
thermograph data (teal), and Evergreen daily and weekly measurements (yellow) from
the summer of 2012 and the winter of 2013 at Fiberville (PRM 63R), Above Clyde (PRM
59R), and Hepco USGS (PRM 45.1L).
The absolute 501h and 90th percentile error along with the standard error of the estimates
(SEE) are given in Table 9. The fits are very good.
Table 9. Modeled vs. University of Tennessee measured 50th and 90th percentile
absolute error, and SEE for Fiberville, Above Clyde and Hepco USGS.
Fiberville
(PRM 63R)
Above Clyde
(PRM 59R)
Hepco Gage
(PRM 45.1 L)
5 Oth percentile error (°C)
0.6
0.8
1.1
goth percentile error (°C)
1.8
2.3
2.6
SEE (°C)
1.0
1.2
1.4
For comparison, and to demonstrate how good the fits truly are, a comparison of the
University of Tennessee hourly measurements versus the daily or weekly Evergreen
measurements during the same 4 months of monitoring (summer 2012 and winter 2013)
are shown in Table 10. The 50th and 90th percentiles are not greatly different between
Tables 9 and 10, with generally smaller values in Table 10. This indicates that the 1-D
thermal model can predict river temperatures almost as well as a second independent
physical measurement of river temperatures. In other words, the errors in Table 9 are
►SO

relatively small given the errors inherently present when collecting river temperature
measurements.
Table 10. University of Tennessee measured vs. Evergreen measured 50`' and 90rh
percentile absolute error, and SEE for Fiberville, Above Clyde and Hepeo USGS.
Fiberville
(PRM 63R)
Above Clyde
(PRM 59R)
Hepco Gage
(PRM 45.1L)
5 Oth percentile error (°C)
0.4
0.3
0.7
90t percentile error (°C)
L2
0.9
4.3
SEE (°C)
0.9
0.65
1.2
I -D MODELING RESULTS
The calibrated model was applied to the Pigeon River from PRM 64.9 to PRM 42.6 and
over the time span from fall 2005 through Spring 2013. The results of the modeling are
presented in Figures 55 — 81, which compare the Evergreen daily and weekly point
measurements to the 1-D model predictions at Fiberville, Above Clyde, and Hepco
USGS.
A quantitative analysis of the modeled temperatures to the measured temperatures
collected by Evergreen of the five-year period was also conducted. The 50`h and 90`h
percentile absolute errors and the SEE between the numerical model and the Evergreen
measurements are shown in Table 11. The errors are small and only a very small amount
larger than the errors calculated during the calibration phase shown in Table 9. This
result validates the numerical model calibration and subsequent results of its use,
27

Table l 1. Longitudinal model vs. Evergreen measured 50th and 90th percentile
absolute error, and SEE for Fiberville, Above Clyde and Hepco USGS.
Fiberville
(PRM 63R)
Above Clyde
(PRM 59R)
Hepco Gage
(PRM 45.1 L)
5 Otb percentile error (°C)
0.5
0.8
0.9
goth percentile error (°C)
1.3
2.3
2.8
SEE (°C)
1.3
1.9
2.0
MODELED DELTA TEMPERATURES
The increase of river temperature due to the thermal loading from the mill (AT) can be
discerned by modeling the mill effluent temperature equal to the adjacent river
temperature just upstream of the outfall. By modeling the river with the mill turned off
and turned on and then comparing these two set of results, the estimated AT due to the
mill can be calculated directly. The AT was estimated from the fall of 2005 until the
spring of 2013 at Fiberville, Above Clyde, and Hepco USGS; the results are presented in
Figure 82, Table 12 presents the 50th and 90`h percentile of modeled delta temperatures at
Fiberville, Above Clyde, and Hepco USGS from fall 2005 through spring 2013.
28

Table 12. The 90th and 50th percentile weekly (Sun — Sat) average AT (Fall 2005 —
Spring 2013) at three stations.
Fiberville
(PRM 63R)
Above Clyde
(PRM 59R)
Hepco Gage
(PRM 45.1L)
50t percentile increase (°C)
3.1
2.5
0.9
901percentile increase (°C)
6.8
4.8
1.5
To demonstrate a more holistic view of the thermal behavior of the Pigeon River in both
space and time, the results of the longitudinal modeling (specifically the weekly average
delta T) were used to generate a contour plots (Figure 83). The vertical axis is distance
downstream from the outfall and the horizontal axis is the date. Above the zero mark on
the vertical axis a dT of zero is present as this region is above the outfall and represents
ambient conditions. Below 0-mi the dT increases to between 2 and 12 °C depending on
the date. Also evident within the graph are horizontal lines that appear to attenuate the
dT. In fact, these are the contributions of cooler water entering from the tributaries,
namely: Beaver Dam Creek (0.4 mi), Richland Creek (8.4 mi), Crabtree Creek (13.5 mi),
and Johnathons Creek (17.3 mi) downstream of the outfall. When the dT is large, the
tributaries have a marked effect towards cooling the Pigeon River. When the dt is small,
the effect of the tributaries is also small.
In addition to the tributaries cooling the Pigeon River as water flows downstream, it is
apparent that the dT also decreases (becomes more blue) in between the locations of the
tributary confluences. This is due to energy flux towards the atmosphere and earth
WE

beneath the streambed when the Pigeon River temperature is above the ambient
condition. The larger the dT, the higher the temperature gradient and the more quickly
the dT decreases. For instance, the small amount of red and yellow on the plot are
quickly attenuated by a combination of the tributaries mixing in cooler water and energy
flux out of the river. Once the river becomes aqua or blue (dT = 4 or 2 °C, respectively)
the effect of the tributaries and energy flux to the atmosphere and earth diminish.
30

PIGEON RIVER THERMAL PLUME DELINEATION
Thermal Cross Section Measurements
Thermal cross section measurements were collected at the RR bridge below the outfall
(PRM 63,1) and at the Fiberville Bridge (PRM 63) on August 12`' and 29`h 2012. The
goal was to measure the cross sections on a typical summer flow day and a quite low
summer flow day. Unfortunately, for the sampling, the 2012 summer was relatively wet
and extremely low -flow conditions were not available, and 2013 was an even wetter
summer. On both dates and at both locations, a thermal cross-section of the river was
collected on a 0.3 in by 0.3 m grid. Two university of Tennessee personnel lowered a bi-
metal temperature probe attached to a large weight into the river. An eyebolt was affixed
to the top of the weight through which a pulley was placed. A line run through the
pulley, with the temperature sensor attached, allowed for raising and lowering the
temperature sensor at each 0.3 m across the RR bridge and the Fiberville bridge, The
temperature sensor was read with a Campbell Scientific Datalogger, Once all the vertical
measurements at a given position on the bridges were collected, the pulley and weight
were moved 0.3 in across the river and another vertical series of measurements was
collected. This repeated until the entire cross section was completed and required
approximately 2-3 hrs for an entire cross section of temperatures to be collected.
Because the river temperatures were changing due to diurnal cycles during the
measurement of the cross sections, each measurement within each thermal cross section
was adjusted to the corresponding temperature at noon of the sampling day. For
31

example, if a given temperature measurement was 22 °C at 10:00, and the temperature of
the river at Canton USGS increased by 1 °C between 10:00 and 12:00, then the
referenced temperature measurement would be adjusted upward by 1 'C. This process
eliminated, to the maximum extent possible, any artificial temperature gradient measured
across the river due to the time lapse of the cross section measurements.
Thermal Plume Modeling
CORMIX, a US EPA- supported, 3-D mixing zone model, was chosen to model the
thermal plume and how quickly it mixes into the Pigeon River after being released from
the outfall. This mixing zone model analyzes the boundary interactions of heat and its
associated density differences from the ambient condition. By utilizing decay or heat loss
coefficients along with effluent and ambient parameters, CORMIX is capable of
modeling the thermal plume and how quickly it mixes into the entirety of the cross
section as the plume itself is being convected downstream. Visualizations of these
simulations can be prepared to show a map view of the extent of plume mixing
downstream.
Five modeling times were selected based upon the availability of Google Earth imaging
and the dates that the thermal cross-section measurements were collected. For each of
these five times (6/17/2008, 5/30/2009, 8/21/2012, 8/29/2012, 3/13/2013) the actual
measured flow rates of the river and outfall, along with the measured temperatures of the
river and the outfall were used to model how the thermal plume disperses downstream
32

from the outfall (Table 13). Further, the actual geometry of the outfall (three 30-in pipes
extending perpendicularly into the river flow) was accurately incorporated.
Table 13. Flows and Temperatures for the five CORMIX thermal models.
Canton USGS temperature is a USGS source. Outfall temperature and flowrate
were provided by Evergreen. Pigeon River Flow at the outfall was calculated by
subtracting the mill intake flowrate (Evergreen source) from the USGS Canton
Flowrate (USGS source).
Date
Canton
USGS (°C)
Outfall ('Q
Pigeon River Flow at
Outfall (m3 s-')
Outfall Flowrate
W s-)
3/18/2013
7.00
30.9
11.9
1.20
5/30/2009
14.9
36.6
16.5
1.04
6/17/2008
21.1
35.3
2.18
1.03
8/21/2012
19.0
33.3
3.48
1.20
8/29/2012
20.6
34.0
1 2.63
1.22
The river dimensions for the model were determined by using Canton USGS gage water
level data and also by interpreting visual imagery available from Google Earth. First,
three river widths were measured from Google Earth imagery for the reach between river
mile PRM 63.3 and PRM 63: at the Mill Outfall, at the Railroad Bridge, and at Fiberville
Bridge. The average of these three measurements was used to define the width of the
thermal model associated with each Google Earth imagery. For the simulations without
Google Earth imagery, the river width was interpolated from the previous measurements
based on the known river flowrate and Canton USGS gage height.
33

Not only does CORMIX provide a graphical representation of the thermal plume, it also
provides the thermal plume's temperature increase above ambient. Further, it calculates
the average velocity of the thermal plume enabling calculation (in minutes) of the time
required for the thermal plume to transit a given distance downstream.
Results of Thermal Plume Measurements and Modeling
The CORMIX thermal plume models were used to simulate the thermal plume from
PRM 63.3 to 63.0 and were compared to either a Google Earth aerial satellite image
and/or a measured thermal cross-section of the area. Figure 84 shows a comparison of
the CORMIX results to a Google Earth image of the same time, 5/30/2009. In the upper
Google Earth image the color within the river delineates the outer boundary of the
thermal plume. The middle image is a graphical representation of the plume predicted
via CORMIX. The results are very similar with the plume almost extending across the
river. Just beneath the middle image are the transit times for the plume to reach a given
location downstream of the outfall, in minutes. The lower image is a graph of the
average increase of temperature (°C) of the plume at a given distance and travel time
downstream from the outfall. All three images share the same scale down river. The red
vertical bar marks the location of the mill outfall, the yellow vertical bar marks the
location of the RR Bridge, and the blue vertical bar marks the location of the Fiberville
Bridge.

Figure 85 is similar to Figure 84 but shows 3/18/2013 when the flow was less, at 11.9
m3/s. Correspondingly the model predicts that the thermal plume mixes across the width
of the river more rapidly and the associated transit times are slightly longer. The Google
Earth image shows a different trend; the river color (and the thermal plume) stays along
the left bank longer than in Figure 83 when the flowrate was larger. These two images
demonstrate the difficulty of precisely modeling thermal plumes in a natural streambed.
Figure 86 presents modeling and Google Imagery from a very low flow day, 6/17/2008,
where the flowrate was only 2.18 m3/s. Both the CORMIX modeling and the Google
imagery show the plume rapidly mixing across the river.
Figure 87 and 88 show a comparison of the CORMIX modeling to the measured thermal
cross sections. The top two images of each figure show the interpolated measured
thermal cross sections (yellow perimeter and vertical line collected at RR Bridge, and
blue perimeter and vertical line collected at the Fiberville Bridge). The middle and lower
images are similar to those presented in Figures 84-86. Figures 87 and 88 both represent
moderately to very low flow rates of 3.48 and 2.63 m3/s respectively. And although the
CORMIX modeling of these two days shows complete mixing of the plumes very
rapidly, there is still actually a thermal signature of the plume across the cross sections.
In both cases the left side at the RR bridge, upper most images, has significantly warmer
temperatures on the left side of the river, the same side as the outfall. There is also a
smaller temperature gradient across the river at Fiberville for the 3.48 m3/s measurement.
These persistent temperature differences across the river even during low flow conditions
35

are consistent with the four months of thermograph data showing that the thermal plume
is not fully mixed at Fiberville, particularly when the flow rate is moderate to high.
36

REFERENCES
Caissie, D., M. G. Satish, and N. El-Jabi. 2005. Predicting river water temperatures using
the equilibrium temperature concept with application on Miramichi River
catchments (New Brunswick, Canada), Hydrological Processes. 19:2137:2159,
EA Engineering Science and Technology Inc. 1987. Synoptic survey of physical and
biological condition of the pigeon river in the vicinity of Champion International,
Canton Mill, Prepared for Champion International Corporation.
EA Engineering Science and Technology Inc. 2001. Pigeon River Temperature Model
(1996-2000). Prepared for Blue Ridge Paper Products Inc.
Edinger, J. E., D. K. Brady, and J. C. Geyer. 1974. Heat exchange and transport in the
environment. Prepared for Electric Power Institute. Cooling Water Discharge
Research Project (RP-4), pp. 125.
Morin G. and D. Couillard 1990. Predicting river temperatures with a hydrological
model. In Encyclopedia of Fluid Mechanic, Surface and Groundwater Flow
Phenomena, Vol. 10. Gulf Publishing Company: Houston, TX; 171-209.
Rutherford, J. C., J. B. Macaskill, and B. L. Williams. 1993. Natural water temperature
variations in the lower Waikato River, New Zealand, New Zealand Journal of
Marine and Freshwater Research. 27:71-85
37

Figure 1 - Google Earth image of Above Mill at Pigeon River Mile (PRM 64.55R) to Above Railroad Bridge (PRM 63.25R)............. 6
Figure 2 - Google Earth image of Railroad Bridge at Pigeon River Mile 63.2, measured at Right/Center/Left side (PRM 63.2R/C/L) to
the Beaver Dam Creek / Pigeon River Confluence (PRM 62.9T)............................................................................................................. 7
Figure 3 - Google Earth image of Fiberville Bridge (PRM 63R) to Pump Station (PRM 62.5R)............................................................. 8
Figure 4 - Google Earth image of Pump Station (PRM 62.5R) to Above Clyde at (PRM 59R)................................................................ 9
Figure 5 - Google Earth image of Above Clyde (PRM 59R) to Richland Creek / Pigeon River confluence (PRM 54.9T).................... 10
Figure 6 - Google Earth image of Hyder Mt. (PRM 55.5L) to the Crabtree Creek / Pigeon River confluence (PRM 49.8T)............... 11
Figure 7 - Google Earth image of the Crabtree Creek / Pigeon River Confluence (PRM 49.8T) to Hepco Gage (PRM 45.IL) ............ 12
Figure 8 - Google Earth image of Waterville Bridge (PRM 25.2L) to Bluffton (PRM 19.3R): all locations in Tenn. and below
WatervilleLake......................................................................................................................................................................................... 13
Figure 9 - Google Earth image of Warren Wilson College at Swannanoa River Mile 11.3 (SRM 11.3L) and Exit 50 — Interstate 40 at
(SRM 1.6L)............................................................................................................................................................................................... 14
Figure 10 - Summer 2012 measured temperatures at Above Mill (PRM 64.55R) located above the outfall........................................... 15
Figure 11 - Summer 2012 measured temperatures at Just Above Dam (PRM 63.35R) located above the outfall, and at Above Railroad
Bridge (PRM 63.25R) located below the outfall but on the opposite side of the Pigeon River from it ................................................... 16
Figure 12 - Summer 2012 measured temperatures of the Mill Outfall (PRM 63.30), prior to the effluent entering the river. The outfall
enters the Pigeon River on its left side (reference facing downstream)................................................................................................... 17
Figure 13 - Summer 2012 measured temperatures at the Left, Center, and Right side of the Railroad Bridge (PRM 63.2L/C/R)......... 18
Figure 14 - Summer 2012 measured temperatures within tributaries prior to their confluence with the Pigeon River at: (PRM 63.15T)
Camp Creek, (PRM 62.9T) Beaver Dam Creek, and (PRM 54.9T) Richland Creek. Camp Creek is often very shallow such that the
sensor does not stay fully submerged rendering the spikey behavior....................................................................................................... 19
Figure 15 - Summer 2012 measured temperatures at Below Railroad Bridge (PRM 63.1R).................................................................. 20
Figure 16 - Summer 2012 measured temperatures at Fiberville Bridge (PRM 63R)............................................................................... 21
Figure 17 - Summer 2012 measured temperatures at Pump Station (PRM 62.5R).................................................................................. 22
Figure 18 - Summer 2012 measured temperatures at DO Station (PRM 61R)........................................................................................ 23
Figure 19 - Summer 2012 measured temperatures Above Clyde (PRM 59R)......................................................................................... 24
Figure 20 - Summer 2012 measured temperatures at Hyder Mt (PRM 55.5L)........................................................................................ 25
Figure 21 - Summer 2012 measured temperatures at River View (PRM 53.5R)..................................................................................... 26
Figure 22 - Summer 2012 measured temperatures within tributaries prior to their confluence with the Pigeon River at: (PRM 49.8T)
Crabtree Creek, (PRM 46T) Jonathan's Creek, (PRM 42.7T) Fine's Creek. Sensor at PRM 49.8T was absent for some collection(s) —
replaced..................................................................................................................................................................................................... 27

Figure 23 - Summer 2012 measured temperatures at Hepco Gage (PRM 45.1L)....................................................................................
28
Figure 24 - Summer 2012 measured temperatures at Hepco Bridge (PRM 42.6R).................................................................................
29
Figure 25 - Summer 2012 measured temperatures at Waterville Bridge (PRM 25.2L). Site is in TN., downstream of power station at
NCborder..................................................................................................................................................................................................
30
Figure 26 - Summer 2012 measured temperatures at Trail Hollow (PRM 22L). Site is in TN, downstream of power station at NC
border. Sensor was absent for some data collection(s) - replaced............................................................................................................
31
Figure 27 - Summer 2012 measured temperatures at Bluffton (PRM 193R). Site is in TN, downstream of power station at NC border.
...................................................................................................................................................................................................................
32
Figure 28 - Summer 2012 measured temperatures at Warren Wilson College (SRM 11.3L). This is a reference stream site within the
SwannanoaRiver......................................................................................................................................................................................
33
Figure 29 - Summer 2012 measured temperatures at Exit 50 — Interstate 40 (SRM 1.6L). This is a reference stream site within the
SwannanoaRiver......................................................................................................................................................................................
34
Figure 30 - Winter 2012 measured temperatures of the Mill Outfall (PRM 63.30), prior to the effluent entering the river. The outfall
entersthe Pigeon River on its left side......................................................................................................................................................
35
Figure 31 - Winter 2013 measured temperatures Above Railroad Bridge (PRM 63.25R). The subzero temperatures and large daily
variability beginning in early February resulted from beaching of the sensor and are more reflective of ambient air temperatures......
36
Figure 32 - Winter 2012 measured temperatures at the Left and Right side of the Railroad Bridge (PRM 63.2L/R). The center sensor
wasabsent upon attempted retrieval.........................................................................................................................................................
37
Figure 33 - Winter 2012 measured temperatures within tributaries prior to their confluence with the Pigeon River at: (PRM 63.15T)
Camp Creek, (PRM 62.9T) Beaver Dam Creek, and (PRM 54.9T) Richland Creek. Camp Creek is often very shallow such that the
sensor does not stay fully submerged rendering the spikey behavior.......................................................................................................
38
Figure 34 - Winter 2013 measured temperatures at Below Railroad Bridge (PRM 63.1R).....................................................................
39
Figure 35 - Winter 2013 measured temperatures at Fiberville Bridge (PRM 63R)..................................................................................
40
Figure 36 - Winter 2013 measured temperatures at Pump Station (PRM 62.5R)....................................................................................
41
Figure 37 - Winter 2013 measured temperatures at DO Station (PRM 61R). The short collection period was due to an erroneous
settingon the sensor at deployment..........................................................................................................................................................
42
Figure 38 - Winter 2013 measured temperatures at Above Clyde (PRM 59R)........................................................................................
43
Figure 39 - Winter 2013 measured temperatures at Hyder Mt. (PRM 55.5L)..........................................................................................
44
Figure 40 - Winter 2013 measured temperatures at River View (PRM 53.5R).......................................................................................
45
Figure 41 - Winter 2012 measured temperatures within tributaries prior to their confluence with the Pigeon River at: (PRM 49.8T)
Crabtree Creek, (PRM 46T) Jonathan's Creek, (PRM 42.7T) Fine's Creek............................................................................................
46
rA

Figure 42 - Winter 2013 measured temperatures at Hepco Gage (PRM 45.1L)......................................................................................
47
Figure 43 - Winter 2013 measured temperatures at Hepco Bridge (PRM 42.6R). It appears that in late February the sensor spent
several days beached and out of the water measuring air temperatures...................................................................................................
48
Figure 44 - Winter 2013 measured temperature at Trail Hollow (PRM 22L). Site is in TN, downstream of power station at NC border.
...................................................................................................................................................................................................................
49
Figure 45 - Winter 2012 measured temperatures at Warren Wilson College (SRM 11.3L). This is a reference stream site within the
SwannanoaRiver......................................................................................................................................................................................
50
Figure 46 - Winter 2012 measured temperatures at Exit 50 — Interstate 40 (SRM 1.6L). This is a reference stream site within the
SwannanoaRiver......................................................................................................................................................................................
51
Figure 47 — A comparison of the summer ambient Pigeon River Temperatures to the reference stream, the Swannanoa River. Shown
are: Canton USGS (PRM 64.9), Warren Wilson College, (SRM 11.9L), and Exit 50 —Interstate 40 (SRM 1.6L)................................
52
Figure 48 - A comparison of the winter ambient Pigeon River Temperatures to the reference stream, the Swannanoa River. Shown
are: Canton USGS (PRM 64.9), Warren Wilson College, (SRM 11.9L), and Exit 50 — Interstate 40 (SRM 1.6L)................................
53
Figure 49 - Summer 2012 modeled, measured, and Evergreen measured temperatures for Fiberville Bridge (PRM 63R)....................
54
Figure 50 - Summer 2012 modeled, measured, and Evergreen measured temperatures for Above Clyde (PRM 59R)..........................
55
Figure 51 - Summer 2012 modeled, measured, and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).......................
56
Figure 52 - Winter 2013 modeled, measured, and Evergreen measured temperatures for Fiberville Bridge (PRM 63R)......................
57
Figure 53 - Winter 2013 modeled, measured and Evergreen measured temperatures for Above Clyde (PRM 59R)..............................
58
Figure 54 - Winter 2013 modeled, measured, and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).........................
59
Figure 55 - The 2005 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R)..............................................
60
Figure 56 - The 2005 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R)....................................................
61
Figure 57 - The 2005 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).................................................
62
Figure 58 - The 2006 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R)..............................................
63
Figure 59 - The 2006 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R)....................................................
64
Figure 60 - The 2006 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).................................................
65
Figure 61 - The 2007 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R)..............................................
66
Figure 62 - The 2007 modeled and Evergreen, measured temperatures for Above Clyde (PRM 59R)....................................................
67
Figure 63 - The 2007 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).................................................
68
Figure 64 - The 2008 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R)..............................................
69
Figure 65 - The 2008 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R)....................................................
70
Figure 66 - The 2008 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).................................................
71
3

Figure 67 - The 2009 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R)..............................................
72
Figure 68 - The 2009 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R)....................................................
73
Figure 69 - The 2009 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).................................................
74
Figure 70 - The 2010 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R)..............................................
75
Figure 71 - The 2010 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R)....................................................
76
Figure 72 - The 2010 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).................................................
77
Figure 73 - The 2011 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R)..............................................
78
Figure 74 - The 2011 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R)....................................................
79
Figure 75 - The 2011 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).................................................
80
Figure 76 - The 2012 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R)..............................................
81
Figure 77 - The 2012 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R)....................................................
82
Figure 78 - The 2012 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).................................................
83
Figure 79 - The 2013 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R)..............................................
84
Figure 80 - The 2013 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R)....................................................
85
Figure 81 - The 2013 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).................................................
86
Figure 82 — Weekly (Sun — Sat) average modeled delta T (mill on vs. mill off) for Fiberville (PRM 63R), Above Clyde (PRM 59R),
andHepco USGS (PRM 45.1L)...............................................................................................................................................................
87
Figure 83 — Weekly (Sun — Sat) average modeled delta T (°C) from 2005-2013 plotted versus distance downstream of the outfall. The
purple above the outfall designates ambient temperatures. The horizontal lines that effectively attenuate the dTs are due to cool water
entering from tributaries at: Beaver Dam Creek (0.4 mi), Richland Creek (8.4 mi), Crabtree Creek (13.5 mi), and Johnathons Creek
(17.3 mi) downstream of the outfall.........................................................................................................................................................
88
Figure 84 — Upper panel=Google Earth image of the zone of mixing between the outfall and Fiberville Bridge; middle
panel=schematic of temperature elevations above ambient river temperature in this reach in plan view with flow -time durations;
bottom panel --time course of temperature change above ambient in the zone of mixing. Vertical lines mark distances in relation to the
photograph................................................................................................................................................................................................
89
Figure 85 - Upper panel=Google Earth image of the zone of mixing between the outfall and Fiberville Bridge; middle
panel=schematic of temperature elevations above ambient river temperature in this reach in plan view with flow -time durations;
bottom panel —time course of temperature change above ambient in the zone of mixing. Vertical lines mark distances in relation to the
photograph................................................................................................................................................................................................
90
Figure 86 - Upper panel=Google Earth image of the zone of mixing between the outfall and Fiberville Bridge; middle
panel=schematic of temperature elevations above ambient river temperature in this reach in plan view with flow -time durations;
C!

bottom panel --time course of temperature change above ambient in the zone of mixing. Vertical lines mark distances in relation to the
photograph................................................................................................................................................................................................ 91
Figure 87 - Upper panel=measured thermal cross section at RR Bridge; 2nd panel = measured thermal cross section at Fiberville
bridge; 3rd panel = schematic of temperature elevations above ambient river temperature in this reach in plan view with flow -time
durations; 4th panel --time course of temperature change above ambient in the zone of mixing. Vertical lines mark distances in relation
tothe photograph...................................................................................................................................................................................... 92
Figure 88 - Upper panel=measured thermal cross section at RR Bridge; 2nd panel = measured thermal cross section at Fiberville
bridge; 3rd panel = schematic of temperature elevations above ambient river temperature in this reach in plan view with flow -time
durations; 4th panel --time course of temperature change above ambient in the zone of mixing. Vertical lines mark distances in relation
tothe photograph...................................................................................................................................................................................... 93
5

Figure 1 - Google Earth image of Above Mill at Pigeon River Mile (PRM 64.55R) to Above Railroad Bridge
(PRM 63.25R).

Figure 2 - Google Earth image of Railroad Bridge at Pigeon River Mile 63.2, measured at Right/Center/Left
side (PRM 63.2R/C/L) to the Beaver Dam Creek / Pigeon River Confluence (PRM 62.9T).
7

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(PRM 64.55R) Above Mill
30
28
V
26
a�
L
a, 24
Q.
E
H
22
20
18
7/12/12 8/12/13 9/5/13
Figure 10 - Summer 2012 measured temperatures at Above Mill (PRM 64.55R) located above the outfall.
15

30
U
26
a,
L
a 24
E
H
22
20
MM
I
1
� � I
I I
c 1
1 I I ' � •I I '� j1! � PY1jI l�1 �!
7/12/12
(PRM 63.35R) Just Above Dam
(PRM 63.25R) Above Railroad Bridge
8/12/13
A �II�Ii�I�IVV ��l
9/5/13
Figure 11 - Summer 2012 measured temperatures at Just Above Dam (PRM 63.35R) located above the
outfall, and at Above Railroad Bridge (PRM 63.25R) located below the outfall but on the opposite side of the
Pigeon River from it.
16

(PRM 63.3L) Mill Outfall
38
U
0. 36
a�
a�
E
34
32
7/12/11 8/12/12 9/5/12
Figure 12 - Summer 2012 measured temperatures of the Mill Outfall (PRM 63.30), prior to the effluent
entering the river. The outfall enters the Pigeon River on its left side (reference facing downstream).
17

(PRM 63.2L) Railroad Bridge
35
(PRM 63.2C) Railroad Bridge
33
(PRM 63.2R) Railroad Bridge
31
U i
r d 191
25
23
t
21
I�
19
7/12/12 8/12/13 9/5/13
Figure 13 - Summer 2012 measured temperatures at the Left, Center, and Right side of the Railroad Bridge
(PRM 63.2L/C/R).
18

—(PRM 63.15T) Camp Creek
35
(PRM 62.9T) Beaver Dam Creek
33
(PRM 54.9T) Richland Creek
31
u
29
25
., . .:
CL
23
I a
`
•1�`ti •*'�tl•;'��=4�;•• k �•�.' a CIS
A,
21
r • « t �' a
3 o e a
f •'
17
4
=1
;`
15
13
7/12/12
8/12/13 9/5/13
Figure 14 - Summer 2012 measured temperatures within tributaries prior to their confluence with the Pigeon River at: (PRM
63.15T) Camp Creek, (PRM 62.9T) Beaver Dam Creek, and (PRM 54.9T) Richland Creek. Camp Creek is often very shallow
such that the sensor does not stay fully submerged rendering the spikey behavior
19

—(PRM 63.1R) Below Railroad Bridge
30
28
v
_. 26
a�
L
4a
a� 24
Q.
E
22
20
18
7/12/12 8/12/13 9/5/13
Figure 15 - Summer 2012 measured temperatures at Below Railroad Bridge (PRM 63.1R)
20

(PRM 63R) Fiberville Bridge
30
28
U
26
a,
L
a� 24
Q.
E
22
20
18
7/12/12 8/12/13 9/5/13
Figure 16 - Summer 2012 measured temperatures at Fiberville Bridge (PRM 63R).
21

(PRM 62.5R) Pump Station
33
31
29
U
0
L 27
L
L 25
E
~ 23
21
19
17
7/12/12 8/12/13 9/5/13
Figure 17 - Summer 2012 measured temperatures at Pump Station (PRM 62.5R).
22

(PRM 61R) DO Station
31
29
U
0
-- 27
d
L
L
Q, 25
E
PT 23
21
19
7/12/12 8/12/13 9/5/13
Figure 18 - Summer 2012 measured temperatures at DO Station (PRM 61R).
23

—(PRM 59R) Above Clyde
31
29
U
-- 27
d
L
3
a-+
cc
L
CL 25
E
23
21
19
7/12/12 8/12/13 9/5/13
Figure 19 - Summer 2012 measured temperatures Above Clyde (PRM 59R).
r"

—(PRM 55.5L) Hyder Mt.
29
27
V
0
25
M
a
a.
E
23
21
19
7/12/12 8/12/13 9/5/13
Figure 20 - Summer 2012 measured temperatures at Hyder Mt (PRM 55.5L).
25

—(PRM 53.5R) River View
31
29
v
-- 27
a�
L
L
Q. 25
E
23
21
19
7/12/12 8/12/13 9/5/13
Figure 21 - Summer 2012 measured temperatures at River View (PRM 53.5R).

29
27
OU
25
23
ca
CL
E
21
I I
h1 -
19r,
,
t 8
17
15
7/12/12
(PRM 49.8T) Crabtree Creek
- (PRM 46T) Johnathan's Creek
(PRM 42.7T) Fine's Creek
I�I
z g��
i
8/12/13
9/5/13
Figure 22 - Summer 2012 measured temperatures within tributaries prior to their confluence with the
Pigeon River at: (PRM 49.8T) Crabtree Creek, (PRM 46T) Jonathan's Creek, (PRM 42.7T) Fine's Creek.
Sensor at PRM 49.8T was absent for some collection(s) — replaced.
27

(PRM 45.1L) Hepco Gage
33
31
-- 29
v
0
L 27
Q. 25
E
~ 23
21-0
19
17
7/12/12 8/12/13 9/5/13
Figure 23 - Summer 2012 measured temperatures at Hepeo Gage (PRM 45.1L).
28

(PRM 42.6R) Hepco Bridge
30
28
26
U
0
24
ca
CL 22
E
~ 20-0
18
16
14
7/12/12 8/12/13 9/5/13
Figure 24 - Summer 2012 measured temperatures at Hepco Bridge (PRM 42.6R).

(PRM 25.2L) Waterville Bridge
27
25
V
0
GJ
23
�a
a,
Q.
E
21
19
17
7/12/12 8/12/13 9/5/13
Figure 25 - Summer 2012 measured temperatures at Waterville Bridge (PRM 25.2L). Site is in TN.,
downstream of power station at NC border.
30

(PRM 22L) Trail Hollow
33
31
29
V
0
i 27
L
CL 25
E
~ 23
21
19
17
8/23/12 9/5/14
Figure 26 - Summer 2012 measured temperatures at Trail Hollow (PRM 22L). Site is in TN, downstream of
power station at NC border. Sensor was absent for some data collection(s) - replaced.
31

(PRM 19.3R) Bluffton
29
27
U
-- 25
L
L
Q. 23
E
21
19
17
7/12/12 8/12/13 9/5/13
Figure 27 - Summer 2012 measured temperatures at Bluffton (PRM 19.3R). Site is in TN, downstream of
power station at NC border.
32

(SRM 11.3L) Warren Wilson College
29
27
U
0
-- 25
a�
L
L
CL 23
H
21
19
17
7/12/12 8/12/13 9/5/13
Figure 28 - Summer 2012 measured temperatures at Warren Wilson College (SRM 11.3L). This is a
reference stream site within the Swannanoa River.
33

(SRM 1.6L) Exit 50 - Interstate 40
29
27
U
0
-- 25
a�
c�
a 23
E
21
19
17
7/12/12 8/12/13 9/5/13
Figure 29 - Summer 2012 measured temperatures at Exit 50 — Interstate 40 (SRM 1.6L). This is a reference
stream site within the Swannanoa River.
34

(PRM 63.3L) Mill Outfall
33
31
V
0
29
�a
L
cQ
G
27
25
23
1/25/13 2/25/13 3/18/13
Figure 30 - Winter 2012 measured temperatures of the Mill Outfall (PRM 63.30), prior to the effluent
entering the river. The outfall enters the Pigeon River on its left side.
35

(PRM 63.25R) Above Railroad Bridge
20
15
U
0
-- 10
a�
L
L
a 5
E
0
-5
-1.0
1/25/13 2/25/13 3/18/13
Figure 31 - Winter 2013 measured temperatures Above Railroad Bridge (PRM 63.25R). The subzero
temperatures and large daily variability beginning in early February resulted from beaching of the sensor
and are more reflective of ambient air temperatures.
36

18
16
_ 14
U
-- 12
a�
L 10
a�
C
H 8
6
4
2
0
1/25/13
(PRM 63.2L) Railroad Bridge
(PRM 63.2R) Railroad Bridge
2/25/13
3/18/13
Figure 32 - Winter 2012 measured temperatures at the Left and Right side of the Railroad Bridge (PRM
63.2L/R). The center sensor was absent upon attempted retrieval.
37

—(PRM 63.15T) Camp Creek
35
(PRM 62.9T) Beaver Dam Creek
30 (PRM 54.9T) Richland Creek
-- 25
U
0
20
�a
Q. 15
E
~ 10
5 •t. .
0
-5
1/25/13 2/25/13 3/18/13
Figure 33 - Winter 2012 measured temperatures within tributaries prior to their confluence with the Pigeon River at: (PRM
63.15T) Camp Creek, (PRM 62.9T) Beaver Dam Creek, and (PRM 54.9T) Richland Creek. Camp Creek is often very shallow
such that the sensor does not stay fully submerged rendering the spikey behavior.
38

(PRM 63.1R) Below Railroad Bridge
15
V
0
-- 10
GJ
L
fa
L
Q
E
5
0
1/25/13 2/25/13 3/18/13
Figure 34 - Winter 2013 measured temperatures at Below Railroad Bridge (PRM 63.111).
39

(PRM 63R) Fiberville Bridge
14
12
OU 10
a�
L
8
L
Q
6
4
2
0
2/15/13 3/18/13
Figure 35 - Winter 2013 measured temperatures at Fiberville Bridge (PRM 63R).
HIl

(PRM 62.5R) Pump Station
14
12
V
O
-- 10
a,
L
CO
L
C i8
c�. a.+
i
6
4
2
2/15/13 3/18/13
Figure 36 - Winter 2013 measured temperatures at Pump Station (PRM 62.5R).
41

(PRM 61R) DO Station
15
13
U
0
d 11
L
L
CQ
G
a g
7
5
3
2/15/14 2/18/13
Figure 37 - Winter 2013 measured temperatures at DO Station (PRM 61R). The short collection period was
due to an erroneous setting on the sensor at deployment.
42

(PRM 59R) Above Clyde
15
13
U
0
--- 11
CL
a�
L
L
a, 9
E
7
5
3
2/15/14 3/18/13
Figure 38 - Winter 2013 measured temperatures at Above Clyde (PRM 59R).
43

(PRM 55.5L) Hyder Mt.
14
12
U
0
--- 10
a,
L
8
cu
CL
G
6
4
2
0
1/25/13 2/25/13 3/18/13
Figure 39 - Winter 2013 measured temperatures at Hyder Mt. (PRM 55.5L).
44

(PRM 53.5R) River View
14
12
U
0
10
c�
L
a,
a
E
8
6
4
1/25/13 2/25/13 3/18/13
Figure 40 - Winter 2013 measured temperatures at River View (PRM 53.5R).
45

21
19
17
U 15
0
E 9
7
5
3
1
1
(PRM 49.8T) Crabtree Creek
(PRM 46T) Jonathan's Creek
(PRM 42.7T) Fine's Creek
t
2/15/13 3/18/13
Figure 41 - Winter 2012 measured temperatures within tributaries prior to their confluence with the Pigeon
River at: (PRM 49.8T) Crabtree Creek, (PRM 46T) Jonathan's Creek, (PRM 42.7T) Fine's Creek.

(PRM 45.1L) Hepco Gage
15
13
V
CL
0
-- 11
a�
L
L
a, 9
E
7
5
3
2/15/14 3/18/13
Figure 42 - Winter 2013 measured temperatures at Hepeo Gage (PRM 45.1L).
47

(PRM 42.6R) Hepco Bridge
20
15
U
0
d
10
c�
a�
a
E
5
0
-5
1/25/13 2/25/13 3/18/13
Figure 43 - Winter 2013 measured temperatures at Hepco Bridge (PRM 42.6R). It appears that in late
February the sensor spent several days beached and out of the water measuring air temperatures.
48

(PRM 22L) Trail Hollow
15
13
U
0
-- 11
a�
L
L
a, g
a
E
7
5
3
2/15/13 3/18/13
Figure 44 - Winter 2013 measured temperature at Trail Hollow (PRM 22L). Site is in TN, downstream of
power station at NC border.

(SRM 11.3L) Warren Wilson College
14
12
U
0
a�
10
8
Q.
E
6
4
2
0
1/25/13 2/25/13 3/18/13
Figure 45 - Winter 2012 measured temperatures at Warren Wilson College (SRM 11.3L). This is a reference
stream site within the Swannanoa River.
50

(SRM 1.6L) Exit 50 - Interstate 40
14
12
0
0
-- 10
d
L
(� 8
L O
CU
Q
E
6
4
2
0
1/25/13 2/25/13 3/18/13
Figure 46 - Winter 2012 measured temperatures at Exit 50 — Interstate 40 (SRM 1.6L). This is a reference
stream site within the Swannanoa River.
51

29
27
V
-- 25
a�
L
L
Q 23
21
19
17
7/12/12
t
Canton USGS
(SRM 11.3L) Warren Wilson College
(SRM 1.61L) Exit 50 - Interstate 40
8/12/13
9/5/13
Figure 47 — A comparison of the summer ambient Pigeon River Temperatures to the reference stream, the
Swannanoa River. Shown are: Canton USGS (PRM 64.9), Warren Wilson College, (SRM 11.9L), and Exit
50 — Interstate 40 (SRM 1.6L).
52

14
12
t
10 rat
r, s •'
Canton USGS
(SRM 11.3L) Warren Wilson College
(SRM 1.6L) Exit 50 - Interstate 40
•
I
I
'1' ` i
.` I
I t
L Y
a
2
I
0
1/25/13
2/25/13
3/18/13
Figure 48 - A comparison of the winter ambient Pigeon River Temperatures to the reference stream, the
Swannanoa River. Shown are: Canton USGS (PRM 64.9), Warren Wilson College, (SRM 11.9L), and Exit
50 — Interstate 40 (SRM 1.6L).
53

35
Fiberville Modeled
+ Fiberville Measured
Evergreen Daily Measurement (09:00)
30
0
25
IL
IN
wCL
+{
E
20
15
10
7/10/12
7/20/12 7/30/12 8/9/12 8/19/12 8/29/12 9/8/12
Figure 49 - Summer 2012 modeled, measured, and Evergreen measured temperatures for Fiberville Bridge
(PRM 63R).
54

35
• Above Clyde Modeled
Above Clyde Measured
Evergreen Daily Measurement (09:00)
30
#: +
+
+ + +.
+
*-, ; e ;
# �+'
-. a$+ r+�.
cu
r
Q
E
20
H
15
10
7/10/12 7/20/12 7/30/12 8/9/12 8/19/12 8/29/12 9/8/12
Figure 50 - Summer 2012 modeled, measured, and Evergreen measured temperatures for Above Clyde
(PRM 59R).
55

35 Hepco USGS Modeled
Hepco USGS Measured
Evergreen Weekly Measurement (09:00)
30
++*+ A +
a+ a
25
■a.�s
E 20
H
15
10
7/10/12 7/20/12 7/30/12 8/9/12 8/19/12 8/29/12 9/8/12
Figure 51 - Summer 2012 modeled, measured, and Evergreen measured temperatures for Hepeo USGS
(PRM 45.1L).
56

20
15
°•' I VA
a, •
10
cu
CL
f + + S
++
z
0
2/10/13 2/20/13 3/2/13 3/12/13 3/22/13
Figure 52 - Winter 2013 modeled, measured, and Evergreen measured temperatures for Fiberville Bridge
(PRM 63R).
57

20
15
0 m+
+
CL
WIN
ni
0
2/10/13 2/20/13 3/2/13 3/12/13 3/22/13
Figure 53 - Winter 2013 modeled, measured and Evergreen measured temperatures for Above Clyde (PRM
59R).
58

20
15
U
0
au
z10
a
U
a
5
0
2/10/13 2/15/13 2/20/13 2/25/13 3/2/13 3/7/13 3/12/13 3/17/13 3/22/13 3/27/13
Figure 54 - Winter 2013 modeled, measured, and Evergreen measured temperatures for Hepeo USGS (PRM
45.1L).
59

35 Fiberville Modeled
Evergreen Daily Measurement (09:00)
30
25
U
0
w 20
M
i 1
a 15
E '!
10Y ! t
5
0
1/2005 2/2005 4/2005 6/2005 7/2005 9/2005 10/2005 12/2005
Figure 55 - The 2005 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R).
.f

35 Fiberville Modeled
Evergreen Daily Measurement (09:00)
30
25
U
0
a� 20
i
i
CL 15
4
10�
5
0
1/2005 2/2005 4/2005 6/2005 7/2005 9/2005 10/2005 12/2005
Figure 56 - The 2005 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R).
61

35 • Hepco USGS Modeled
Evergreen Daily Measurement (09:00)
30
25
U
0
a� 20
L
L
a 15 41i
E
PT10 i
5
0
1/2005 2/2005 4/2005 6/2005 7/2005 9/2005 10/2005 12/2005
Figure 57 - The 2005 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).
62

35
30
25
U
20
L
� S
L `
15
t .x r
e
a S -,
5
0
1/2006 2/2006 4/2006 5/2006 7/2006 9/2006 10/2006 12/2006
Figure 58 - The 2006 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R).
63

35 Fiberville Modeled
Evergreen Daily Measuremen
30
•; i r�� )
25 .
20cu
k ' " •''
a 15
s �� �i }4 4
J,
10
.. IT
5
N
0
1/2006 2/2006 4/2006 5/2006 7/2006 9/2006 10/2006 12/2006
Figure 59 - The 2006 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R).

35 Hepco USGS Modeled
Evergreen Daily Measurement (09:00)
30
25
V j
20 t
L
L
Q. 15
J
10
5
0
1/2006 2/2006 4/2006 5/2006 7/2006 9/2006 10/2006 12/2006
Figure 60 - The 2006 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).
N

35
30
25
U
0
a 20
a15
1�
H
ell,
i i1 � _ .M• t.
1/2007 2/2007 4/2007 6/2007 7/2007 9/2007 10/2007 12/2007
Figure 61 - The 2007 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R).

35
30
25
0
1/2007 2/2007 4/2007 6/2007 7/2007 9/2007 10/2007 12/2007
Figure 62 - The 2007 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R).
67

35
30
25
U
0
20
L
L
E. 15
V�
9
10
5
0 '
1/2007 2/2007 4/2007 6/2007 7/2007 9/2007 10/2007 12/2007
Figure 63 - The 2007 modeled and Evergreen measured temperatures for Hepeo USGS (PRM 45.1L).
68

35 • Fiberville Modeled
Evergreen Daily Measuremer
30 = j
25
G 2015
10 S• �z�.�=f .. 1
1rj 1
5
0
1/2008 2/2008 4/2008 5/2008 7/2008 9/2008 10/2008 12/2008
Figure 64 - The 2008 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R).
.:

35
30 -
25 -
U
a 20 -
L
L
E 15 -
H
10 -
5 -
0
1/2008 2/2008 4/2008 5/2008 7/2008 9/2008 10/2008 12/2008
Figure 65 - The 2008 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R).
70

35 Hepco USGS Modeled
Evergreen Daily Measurement (09:00)
30
J& r
.r r
25 ; 4•
20
cu
L
cu
CL15
10
5
0
1/2008 2/2008 4/2008 5/2008 7/2008 9/2008 10/2008 12/2008
Figure 66 - The 2008 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).
71

35
Z
30
25 4
"20
L
0.15 ' *�
10
u 44 `
5
0
1/2009 2/2009 4/2009 5/2009 7/2009 9/2009 10/2009 12/2009
Figure 67 - The 2009 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R).
72

35
30
25 J• ►; . r
0
20
r � ' V4
a r► r jig10
5
0 I I 1 1
1/2009 2/2009 4/2009 5/2009 7/2009 9/2009 10/2009 12/2009
Figure 68 - The 2009 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R).
73

35 Hepco USGS Modeled
Evergreen Daily Measurement (09:00)
30
rw
25 .'
u
( 20
�a
C.15 '
E
~ F-
10
5 fIWI '
0
1/2009 2/2009 4/2009 5/2009 7/2009 9/2009 10/2009 12/2009
Figure 69 - The 2009 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).
74

35
30
25
Q. 15
F�
P-
WE
5
r ,u
A
s
► IL
4 Ri
0
i i I I I I 1 1
1/2010 2/2010 4/2010 5/2010 7/2010 9/2010 10/2010 12/2010
Figure 70 - The 2010 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R).
75

35
OIJ
25
U
0
a, 20
3
L
Q. 15
F�
9
10
5
0
1/2010 2/2010 4/2010 5/2010 7/2010 9/2010
10/2010 12/2010
Figure 71 - The 2010 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R).
C

35 Hepco USGS Modeled
Evergreen Daily Measurement (09:00)
30
25
, j ■
V
o ■
3 20
i
Q 15 1
10 ■
r�
5
M
0 —
1/2010 2/2010 4/2010 5/2010 7/2010 9/2010 10/2010 12/2010
Figure 72 - The 2010 modeled and Evergreen measured temperatures for Hepeo USGS (PRM 45.1L).
AN

35
we,
25
U
0
U 20
Q.15
F�
H
0-1i1
5
0
1/2011 2/2011 4/2011 5/2011 7/2011 9/2011 10/2011 12/2011
Figure 73 - The 2011 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R).
78

35 • Above Clyde Modeled
Evergreen Daily Measuremen
30
25
o •�
a 15 : j �•�
10
5
"K
0
1/2011 2/2011 4/2011 5/2011 7/2011 9/2011 10/2011 12/2011
Figure 74 - The 2011 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R).
79

35 Hepco USGS Modeled
Evergreen Daily Measurement (09:00)
30
25 `
U
20
L
a 15
E10
5�
0 -
1/2011 2/2011 4/2011 5/2011 7/2011 9/2011 10/2011 12/2011
Figure 75 - The 2011 modeled and Evergreen measured temperatures for Hepeo USGS (PRM 45.1L).
M

35 Fi
E�
30
fill
. ":,* i
25 ' �
�1 r
a� 20 r i
Q. 15 1 t
H JEA
10Sf;;
5 s ,�
0 +
1/2012 2/2012 4/2012 5/2012
7/2012 9/2012 10/2012 12/2012
Figure 76 - The 2012 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R).
81

35
30
25
0
a 20
L
Q. 15
F�
H
10
5
0
i I I i
1/2012 2/2012 4/2012 5/2012 7/2012 9/2012 10/2012 12/2012
Figure 77 - The 2012 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R).
82

35 Hepco USGS Modeled
Evergreen Daily Measurement (09:00)
30
25
0
r
20
� r
a. 15 f
E•
10all
r'
i•
IIA ffil
�
5
0 I
1/2012 2/2012 4/2012 5/2012 7/2012 9/2012 10/2012 12/2012
Figure 78 - The 2012 modeled and Evergreen measured temperatures for Hepeo USGS (PRM 45.1L).
83

35 Fiberville Modeled
Evergreen Daily Measurement (09:00)
30
25
U
0
a� 20
4-1
L
Q. 15
10
5 t ' r
0
1/2013 2/2013 4/2013 6/2013 7/2013 9/2013 10/2013 12/2013
Figure 79 - The 2013 modeled and Evergreen measured temperatures for Fiberville Bridge (PRM 63R).
84

35 - Above Clyde Modeled
Evergreen Daily Measurement (09:00)
30
25
V
0
20
L
L
a. 15
10 + '�
0
1/2013 2/2013 4/2013 6/2013 7/2013 9/2013 10/2013 12/2013
Figure 80 - The 2013 modeled and Evergreen measured temperatures for Above Clyde (PRM 59R).
85

35 • Hepco USGS Modeled
Evergreen Daily Measurement (09:00)
30
25
U
0
20
L
L
Q. 15
E
H
10
At
5 J
d
0
1/2013 2/2013 4/2013 6/2013 7/2013 9/2013 10/2013 12/2013
Figure 81 - The 2013 modeled and Evergreen measured temperatures for Hepco USGS (PRM 45.1L).
:•

14
12 = Hepco US
U
a� 10 r
L
■
8 ■
L ■ • ■
■
E■
W ■■ ■
■
+� 6 + �,
4 .r
■
+
0
11/2005 11/2006 11/2007 11/2008 11/2009 11/2010 11/2011 11/2012
Figure 82 — Weekly (Sun — Sat) average modeled delta T (mill on vs. mill off) for Fiberville (PRM 63R),
Above Clyde (PRM 59R), and Hepco USGS (PRM 45.1L).
87

P
■
s
C
4
8
12
16
20
2006 2007 2008 2009 2010 2011 2012 2013
0
- 2
_ 4
6
8
10
12
Figure 83 — Weekly (Sun — Sat) average modeled delta T (°C) from 2005-2013 plotted versus distance downstream of the
outfall. The purple above the outfall designates ambient temperatures. The horizontal lines that effectively attenuate the dTs
are due to cool water entering from tributaries at: Beaver Dam Creek (0.4 mi), Richland Creek (8.4 mi), Crabtree Creek (13.5
mi), and Johnathons Creek (17.3 mi) downstream of the outfall.
88

Figure 84 — Upper panel=Google Earth image of the zone of mixing between the outfall and Fib�erville Bridge; middle panel=schematic of
temperature elevations above ambient river temperature in this reach in plan view with flow -time durations; bottom panel=time course of
temperature change above ambient in the zone of mixing. Vertical lines mark distances in relation to the photograph.
:•

Figure 85 - Upper panel=Google Earth image of the zone of mixing between the outfall and Fiberville Bridge; middle panel=schematic of
temperature elevations above ambient river temperature in this reach in plan view with flow -time durations; bottom panel=time course of
temperature change above ambient in the zone of mixing. Vertical lines mark distances in relation to the photograph.
.E

+C':.:��..r
.. - �.._ �•"
Delta
T
,:
+
7.9
7.8
7.7
7.6
Miutfall
RR Bridge iberville
7.5
7.4
7.3
7.2
7.1
0 min 9.4 18.9
28.3 37.8 47.2 56.7 66.1 75.6 85.0 94.5 104 113
7
6.9
6.8
6.7
l4
Delta T
6.6
L2
-- - - - ----- - -- - - - -
6.5
LO--._....----
- -----.—_._.. - -- _ .. - - --- -- ---- - --- - - -
6.4
6.3
6.2
6
6.1
4
6
2
0
Figure 86 - Upper panel=Google Earth image of the zone of mixing between the outfall and Fiberville Bridge; middle panel=schematic of
temperature elevations above ambient river temperature in this reach in plan view with flow -time durations; bottom panel=time course of
temperature change above ambient in the zone of mixing. Vertical lines mark distances in relation to the photograph.
91

Delta T
0
°
-2
o
7+
OM 5
10 15 20 25
30 35
6.9
6.8
0
6.7
S
6.6
6.5
2
DM
5 10 15
20 25
6.4
6.3
Outfall
RR Bridge
Fiberville ■
6.2
6.1
6
5.9
0 min 6.6
13.2 19.8 26.5 33.1 39.7 46.3
52.9 59.5 66.1 72.7 79.4
5.8
5.7
14
5.6
0
Delta T
5.5
12
_
g M15.1
5.2
6 5
N
Figure 87 - Upper panel=measured thermal cross section at RR Bridge; 2"d panel = measured thermal cross section at Fiberville bridge;
3rd panel = schematic of temperature elevations above ambient river temperature in this reach in plan view with flow -time durations; 4th
panel=time course of temperature change above ambient in the zone of mixing. Vertical lines mark distances in relation to the
photograph.

Delta T
0
r.,
o o
0 m 5
10 15 20
25 30 35
7.9
7.8
-
0
-- -
J �
_
7.6
i
7.5
-2
O m
5 10
15 20 25
7 4
Mill Outfall
RR Bridge
Fiberville
7.3
7.2
IS
sit
7.1
7
6'9
0min &43
16.9 25.3 33.7 42.1 50.6
59.0 67.5 75.9 84.3 92.8
101
6.8
6.7
14
Delta T
6.6
6.5
10 --
-- —
----
6.4
6.3
6.2
5
6.1
q—
-----
-----------------
6
2
0
Figure 88 - Upper panel=measured thermal cross section at RR Bridge; 2°`' panel = measured thermal cross section at Fiberville bridge;
3"' panel = schematic of temperature elevations above ambient river temperature in this reach in plan view with flow -time durations; 4th
panel --time course of temperature change above ambient in the zone of mixing. Vertical lines mark distances in relation to the
photograph.