NC0003425_Report_20180101

ROXBORO STEAM ELECTRIC PLANT
2017-2018 ENVIRONMENTAL MONITORING REPORT
November 2019
Water Resources
DUKE ENERGY
Raleigh, North Carolina

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Preface
This copy of the report is not a controlled document as detailed in the Environmental Services Biology
Program Quality Assurance Manual. Any changes made to the original of this report subsequent to
the date of issuance can be obtained from:
Water Resources
DUKE ENERGY
410 South Wilmington Street
Raleigh, North Carolina 27601
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Roxboro Steam Electric Plant
2017-2018 Environmental Monitoring Report
Table of Contents
Page
Preface.........................................................................................................................................
i
Listof Tables...............................................................................................................................
iii
Listof Figures..............................................................................................................................
iii
Listof Appendices.......................................................................................................................
iii
Metric -English Conversion and Units of Measure......................................................................
v
WaterChemistry Abbreviations..................................................................................................
v
ExecutiveSummary.....................................................................................................................
vi
2017-2018 Environmental Monitoring Report............................................................................
1
HistoricalOverview...............................................................................................................
1
ReservoirDescription............................................................................................................
3
Objectivesand Methods........................................................................................................
3
Environmental Monitoring Results for 2017-2018................................................................
9
Limnology........................................................................................................................
9
Temperature and Dissolved Oxygen.........................................................................
9
Water Clarity Constituents........................................................................................
10
Nutrients and Phytoplankton Biomass.......................................................................
10
Ions, Hardness, and Specific Conductance................................................................
10
Alkalinityand pH......................................................................................................
11
TraceElements................................................................................................................
11
Arsenic.......................................................................................................................
11
Cadmium....................................................................................................................
12
Copper........................................................................................................................
12
Manganese.................................................................................................................
13
Mercury......................................................................................................................
13
Selenium....................................................................................................................
14
Thallium.....................................................................................................................
14
Fisheries...........................................................................................................................
15
Fish Species Composition..........................................................................................
15
Fish Abundance, Distribution, and Size Structure.....................................................
15
Balanced Indigenous Community..............................................................................
18
FishCommunity Health.............................................................................................
19
BiofoulingMonitoring.....................................................................................................
19
Summary and Conclusions..........................................................................................................
19
References....................................................................................................................................
20
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
List of Tables
Table Page
1 Hyco Reservoir environmental monitoring program ............................................... 6
2 Field sampling and laboratory methods utilized in the Hyco Reservoir
environmental monitoring program......................................................................... 7
3 Statistical analyses performed on data collected for the Hyco Reservoir
environmental monitoring program......................................................................... 8
List of Figures
Figure Page
1 Hyco Reservoir sampling locations......................................................................... 5
List of Appendices
Appendix Page
1 Depth profiles of water temperature, dissolved oxygen, pH, and specific
conductance at Hyco Reservoir during 2017........................................................... 22
2 Depth profiles of water temperature, dissolved oxygen, pH, and specific
conductance at Hyco Reservoir during 2018........................................................... 24
3 Means, ranges, and spatial trends of selected limnological variables from
surface waters of Hyco Reservoir during 2017....................................................... 26
4 Means, ranges, and spatial trends of selected limnological variables from
surface waters of Hyco Reservoir during 2018....................................................... 27
5 Concentrations of chemical variables in surface waters of
Hyco Reservoir during 2017.................................................................................... 28
6 Concentrations of chemical variables in surface waters of
Hyco Reservoir during 2018.................................................................................... 31
7 Long-term trends of selected parameters at Station B2 from Hyco Reservoir
from2009 through 2018.......................................................................................... 34
8 Long-term trends of selected parameters at Station C2 from Hyco Reservoir
from 2009 through 2018.......................................................................................... 33
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9 Long-term trends of selected parameters at Station D2 from Hyco Reservoir
from 2009 through 2018.......................................................................................... 36
10 Long-term trends of selected parameters at Station F2 from Hyco Reservoir
from 2009 through 2018.......................................................................................... 37
11 Means and standard errors of trace element concentrations in sediments and
fish by transect from Hyco Reservoir during 2017................................................. 38
12 Means and standard errors of trace element concentrations in sediments and
fish by transect from Hyco Reservoir during 2018................................................. 39
13 Long-term trends of selenium concentrations in Bluegill, Largemouth Bass, and
White Catfish muscle tissues at Transect C and Transect D from
Hyco Reservoir from 2009 through 2018................................................................ 40
14 Total number and weight of fish collected with electrofishing from Hyco
Reservoir during 2017 and 2018.........................................................................
15
16
17
19
20
21
22
23
Mean catch per hour of fish collected with electrofishing by transect from Hyco
Reservoirduring 2017...........................................................................................
Mean catch per hour of fish collected with electrofishing by transect from Hyco
Reservoirduring 2018...........................................................................................
Length -frequency distributions of Bluegill by transect collected by
electrofishing from Hyco Reservoir during 2017....................................................
Length -frequency distributions of Bluegill by transect collected by
electrofishing from Hyco Reservoir during 2018................................................
Length -frequency distributions of Largemouth Bass by transect collected by
electrofishing from Hyco Reservoir during 2017................................................
Length -frequency distributions of Largemouth Bass by transect collected by
electrofishing from Hyco Reservoir during 2018................................................
Length -frequency distributions of Gizzard Shad by transect collected by
electrofishing from Hyco Reservoir during 2017................................................
Length -frequency distributions of Gizzard Shad by transect collected by
electrofishing from Hyco Reservoir during 2018................................................
41
42
43
45
46
47
ED
Relative weight values versus length for Bluegill, Gizzard Shad, and Largemouth Bass
collected by electrofishing from Hyco Reservoir during 2017 ............................... 50
24 Relative weight values versus length for Bluegill, Gizzard Shad, and Largemouth Bass
collected by electrofishing from Hyco Reservoir during 2018 ............................... 51
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25 Proportional Size Distribution ranges for balanced populations of Bluegill versus
Largemouth Bass and Gizzard Shad versus Largemouth Bass collected from
Hyco Reservoir during 2017 and 2018.................................................................... 52
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2017-2018 Environmental Monitoring Report
Metric -English Conversion and Units of Measure
Length
1 micron (µm) = 4.0 x 10' inch
1 millimeter (mm) = 1000 µm = 0.04 inch
1 centimeter (cm) = 10 mm = 0.4 inch
1 meter (m) = 100 cm = 3.28 feet
1 kilometer (km) = 1000 m = 0.62 mile
Area
1 square meter (m2) = 10.76 square feet
1 hectare (ha) = 10,000 m2 = 2.47 acres
Volume
1 milliliter (ml) = 0.034 fluid ounce
1 liter = 1000 ml = 0.26 gallon
1 cubic meter = 35.3 cubic feet
Weight
1 microgram (µg) = 10-3 mg or
10-6 g = 3.5 x 10-8 ounce
1 milligram (mg) = 3.5 x 10-5 ounce
1 gram (g) = 1000 mg = 0.035 ounce
1 kilogram (kg) = 1000 g = 2.2 pounds
1 metric ton = 1000 kg = 1.1 tons
1 kg/hectare = 0.89 pound/acre
Temperature
Degrees Celsius (°C) = 5/9 (°F-32)
Specific Conductance
µS/cm = Microsiemens/centimeter
Turbidity
NTU = Nephelometric Turbidity Unit
Water Chemistry Abbreviations
Cl- - Chloride TDS - Total dissolved solids Al - Total aluminum
S02"4 - Sulfate TSS - Total suspended solids As - Total arsenic
Cat+ - Total calcium TOC - Total organic carbon Cd - Total cadmium
Mgt+
- Total magnesium TP
- Total phosphorus
Cu -
Total copper
Na+
- Total sodium TN
- Total nitrogen
Hg -
Total mercury
TS - Total solids NH3-N - Ammonia nitrogen Se - Total selenium
NO3+ NO2-N - Nitrate +nitrite -
nitrogen
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2017-2018 Environmental Monitoring Report
Executive Summary
During 2017 and 2018, surface water temperatures, dissolved oxygen concentrations, pH,
specific conductance, and Secchi disk visibility remained within the ranges previously observed in
Hyco Reservoir depending on location. A number of limnological variables measured in the reservoir
surface waters including calcium, chloride, hardness, total dissolved solids, and specific conductance
have stabilized (i.e., trend not increasing) compared to previous years despite some seasonal variation
during 2017 and 2018, primarily due to lower power plant dispatch rates and operation of the Flue
Gas Desulfurization System.
Concentrations of target trace elements, including arsenic, cadmium, copper, mercury, and
selenium, measured in the reservoir surface waters remained below water quality criteria during 2017
and 2018. However, selenium concentrations in the muscle tissues of Bluegill, White Catfish, and
Largemouth Bass continued to be statistically greater at the monitoring location near the discharge
compared to the concentrations at the designated upstream comparison monitoring location during
2017. In 2018, only White Catfish had statistically greater selenium concentrations in muscle tissues
at the monitoring location near the discharge compared to the concentrations in the fish located at the
upstream monitoring location.
Despite receiving a thermal discharge, the fish community in Hyco Reservoir remained a self-
sustaining, balanced population of regionally common species during 2017 and 2018.
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Roxboro Steam Electric Plant
2017-2018 Environmental Monitoring Report
Historical Overview
Duke Energy Progress (DEP; formerly Carolina Power & Light) began construction of Hyco
Reservoir in 1963 to serve as a cooling water source and receiving water discharges from the Roxboro
Steam Electric Plant (Roxboro Plant). After reaching full pool in 1965, the reservoir was noted as a
popular fishery throughout the remainder of the 1960s and most of the 1970s. In 1980, a large-scale fish
kill was observed throughout much of the reservoir after the start-up of Unit 4. Biological monitoring
conducted by Company biologists showed continued declines in the fishery. Special experimental
bioassay studies were conducted and ultimately determined that elevated concentrations of selenium in
the water, food chain, and fish tissues were responsible (i.e., reproductive impairment) for the observed
sport fishery decline in Hyco Reservoir. As a result of elevated selenium concentrations in fish, the
North Carolina Division of Health Services, Department of Health and Human Services, issued an
advisory in August 1988 recommending limitations on human consumption of all fish species from Hyco
Reservoir. In 1989, DEP completed the constructed a dry ash handling system to reduce selenium input
into Hyco Reservoir.
After the startup of the dry ash handling system in late 1989, biological monitoring studies
conducted under the Roxboro Plant National Pollutant Discharge Elimination System (NPDES) permit
demonstrated the effectiveness of the dry fly ash handling system in limiting the amount of selenium
entering the reservoir (CP&L 1991 and 2001, PEC 2008). Selenium concentrations quickly decreased in
the reservoir after the dry fly ash handling system began operation and have remained below the North
Carolina water quality standard of 5µg/liter since 1990. Changes in the aquatic community also reflected
the reduced selenium loading into the reservoir. A gradual shift from selenium -tolerant fish species to
species more typical of southeastern piedmont impoundments was observed following the
commencement of dry ash handling operations.
The fish consumption advisory was modified several times during the recovery period to remove
species from the consumption advisory list as selenium concentrations in the edible flesh of each
individual fish species declined below the established threshold level (i.e., 25 µg/g dry weight at the time;
it was revised to 50 µg/g dry weight in the mid-2000s). In August 2001, the fish consumption advisory on
reservoir was completely rescinded. Hyco Reservoir limnological variables remained mostly unchanged
during the period from 2002 through 2006 and were within the range of values expected for a North
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Carolina piedmont impoundment. During 2007, the reservoir was subjected to the most extensive
drought on record (based on 110-year USGS streamflow records) in North Carolina, which affected water
levels severely. The water levels decreased from full pool of 124.9 meters National Geodetic Vertical
Datum (NGVD) during May 2007 to slightly above the critical elevation of 123.4 meters NGVD in
October 2007 when a substantial rain event reversed the decreasing trend in reservoir water levels. The
drought event and subsequent decrease in lake level was important given that impacts to plant operations
begin to occur when reservoir levels reach 123.4 meters NGDV. Despite minimal flushing of the
reservoir through most of 2007, no overall changes to limnological variables, including selenium
concentrations, were noted that year compared to previous years following dry fly ash operations.
However, an increase in the mean selenium concentrations was observed in muscle tissues of fish
collected near the power plant discharge to Hyco Reservoir. While no increase in selenium mass loading
to Hyco Reservoir occurred during this period due to plant operations, decreased reservoir flushing likely
allowed more selenium to enter the food web and thus influenced tissue concentrations in fish and other
trophic level species.
With the passage of the North Carolina Clean Smokestacks Act of 2002, coal-fired power plants
were required to reduce sulfur emissions 73 percent by 2013. To help meet the requirement fleet -wide,
Flue Gas Desulfurization (FGD) systems (one on each of the four units) were installed at the Roxboro
Plant and wastewater from these treatment systems began discharging in February of 2008. During the
period from 2008 until 2016, a number of limnological constituents including calcium, chloride,
hardness, and total dissolved solids gradually increased throughout the reservoir until recently. However,
trace elements such as arsenic, copper, and selenium in surface waters have continued to remain below
water quality criteria and/or below the laboratory reporting limits.
Beginning in 2014 with the lower cost of natural gas, the Roxboro Plant annual dispatch rates
decreased from the historical 70%-75% range to an average rate of 60% in 2014, 43% in 2015, and even
lower dispatch rates through 2018. The lower dispatch rates for the Roxboro Plant have resulted in
reduced discharges of constituents from the FGD systems as well as lower overall thermal discharge to
the reservoir. With the reduce thermal loading to the reservoir, impacts to the two non-native tilapia
species, Blue Tilapia and Redbelly Tilapia, have become apparent with reduce catch of these species
during fisheries sampling. Tilapia can help control certain vegetation such as naiad and pondweed It is
possible that the reservoir will experience nuisance aquatic vegetation problems as the growth control of
these plant species declines along with the tilapia.
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Reservoir Description
Hyco Reservoir, an impoundment of the Hyco River, is located approximately 5 km south of the
North Carolina/Virginia border in Person and Caswell Counties in the northern Piedmont of North
Carolina. After impoundment, the reservoir water level reached full pool elevation in 1965. Hyco
Reservoir serves as a cooling lake and source of water for the Roxboro Plant. The reservoir has a surface
area of 17.6 km2 (1760 ha); a volume of 9.62 x 107 m3; a drainage area of 471 km2; a mean depth of 6.1
in; a normal elevation of 125.1 in NGVD; an average inflow of 5.7 m3/second; and a mean residence time
of approximately 6 months. The land use along the 256-km shoreline is primarily residential and
secondarily industrial/agricultural. It is classified by the North Carolina Division of Resource as WS-V,
B. This is defined as suitable for primary recreation, aquatic life propagation and maintenance, wildlife,
and agriculture and is suitable for water supply for use by industry to supply to their employees, but not
to municipalities or counties with a raw drinking water supply source.
For environmental monitoring purposes, sampling transects and stations throughout the reservoir
were selected based on their location relative to the power plant effluents entering the main body of the
reservoir at Transect 4 (Figure 1). Transect B is located in the upper reservoir in the North Hyco arm and
Transects C and SHHW 1 are located in the upper reservoir in South Hyco arm. Transect F is located in
the lower reservoir adjacent to the spillway.
Objectives and Methods
The primary objective of the Roxboro Plant 2017-2018 environmental monitoring program was to
provide an assessment of the effect of power plant operations on the water and aquatic organisms of Hyco
Reservoir. Secondary objectives of the program were to document environmental factors impacting the
aquatic community that were not attributable to the power plant, as well as the impact of non-native
aquatic plant and animal species on the reservoir. These objectives were consistent with the biological
monitoring requirements in the NPDES Permit NC0003425.
Limnology (water quality, water chemistry, and chlorophyll a) and trace elements in fish tissues
and sediments (Transects C and D only) were assessed in the reservoir (Figure 1; Tables 1 and 2), and the
results were analyzed using appropriate statistical methods (Table 3). The water chemistry analysis
portion of the limnological variables was performed by laboratories certified by the North Carolina
Department of Environmental Quality (NCDEQ) in water and wastewater testing. Trace element analyses
of sediment and tissues of fish were conducted by an external laboratory using approved analytical
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
methods (EPA methods 6020 and 7471). The accuracy and precision of laboratory analyses of water
chemistry and trace element data were determined with analytical standards, sample replicates, and
reference materials. For calculation of means in this report, concentrations less than the reporting limit
and not estimated were assumed to be at one-half the reporting limit.
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Roxboro
Steam Electric Plant
North Hyco River
% \
ay
Cane Creek
Reservoir
r
Spillway
- Cy 6
S � A
(Outran #006) Auxiliary Intake -� Main
- Dam
5
Discharge D
(Outfa ll #003) Intake
Canal
4- Gypsum Storage Pad
E 4 \
C
8 Dry
A, Ash
_ ` 1 Landfill
Flush
Pond
Gypsum
C) ttliSeng -� Ash
J5 Pond Pond
s�n \
1
Person -Caswell
4 - Lake Authority
Cobbs Creek
0 0.5 1 2
Miles
Figure 1. Hyco Reservoir sampling locations.
South
Hyco River
0 0.75 1.5
Kilometers
3
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Table 1. Hyco Reservoir environmental monitoring program.
Program Frequency Location
Water quality Alternate calendar months
(February, April, June, August, October,
December)
Water chemistry Alternate calendar months
(including trace (February, April, June, August, October,
elements in water) December)
Phytoplankton+ Alternate calendar months
(February, April, June, August, October,
December)
Chlorophyll a Alternate calendar months
(February, April, June, August, October,
December)
Zebra and quagga Alternate calendar months
mussels (February, April, June, August, October,
December)
Electrofishing Once every three calendar months
(March, June, September, December)
Trace elements Once per calendar year
(fish & sediments)
Stations B2, C2, D2, F2, SHHW 1
(surface to bottom at 1-m
intervals)
Stations B2, C2, D2, F2, SHHW 1
(surface)
Stations B2, C2, D2, F2
Stations B2, C2, D2, F2
Main intake structure or water
quality station buoys
Stations Al, A3, 131, B3, Cl, C3,
D1, D5, F1, F3
Transects C and D
+Phytoplankton samples were collected and preserved but were not identified because all chlorophyll a
concentrations measured during 2017 and 2018 were less than 40 mg/L.
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Table 2. Field sampling and laboratory methods utilized in the Hyco Reservoir environmental
monitoring program.
Program Method
Water quality Temperature, dissolved oxygen, pH, and specific conductance were measured with
calibrated multiparameter instruments. Measurements were taken from the surface
to the bottom at 1-m intervals in accordance with procedure NR-00096 Water
clarity was measured with a Secchi disk. Turbidity was measured with a HACH
model 2100Q turbidimeter in accordance with procedure WR-00070.
Water Surface samples were collected either directly or with a nonmetallic sampler,
chemistry transferred to appropriate containers, transported to the laboratory on ice, and
analyzed according to USEPA (1979) and APHA 2012.
Phytoplankton Samples were collected by two methods. Method one used equal amounts of
water from the surface, the Secchi disk transparency depth, and twice the Secchi
disk transparency depth collected with a Van Dorn beta sampler and mixed in a
plastic container. Method two used an integrated depth sampler to collect
representative photic zone composite samples from the surface to twice Secchi
disk transparency depth. The samples were placed in dark bottles, and transported
to the laboratory on ice.
Chlorophyll a Samples were collected by two methods. Method one used equal amounts of
water from the surface, the Secchi disk transparency depth, and twice the Secchi
disk transparency depth collected with a Van Dorn beta sampler and mixed in a
plastic container. Method two used an integrated depth sampler to collect
representative photic zone composite samples from the surface to twice Secchi
disk transparency depth. The samples were placed in 1000 mL dark bottles and
transported to the laboratory on ice. In the laboratory, 250-mL subsamples were
analyzed (NR-00103).
Electrofishing Fifteen -minute samples were collected at each station using a Smith -Root Type
7.5 gpp equipped, Wisconsin -design electrofishing boat with pulsed DC current.
Fish were identified, measured to nearest mm, weighed to nearest gram, examined
for presence of disease and deformities, and released based NR-00080, Rev 1.
Trace elements Water, sediments, and muscle tissue of selected fish were analyzed by standard
analytical techniques in the laboratory for selected trace metals and metalloids. All
media, except water, were homogenized and freeze-dried. All samples were
analyzed by an external laboratory using EPA methods 6020 and 7471. Quality
control was achieved by analytical standards, replicates, and certified reference
materials
Mussel surveys Hardened structures such as docks and buoys were visually inspected for the
presence of zebra mussels and quagga mussels during routine water quality
monitoring.
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Table 3. Statistical analyses performed on data collected for the Hyco Reservoir environmental
monitoring program.
Program Variable Statistical test(s)/model(s)+ Main effect(s)
Water quality Water temperature, specific
conductance, Secchi disk
transparency depth, and
selected chemical variables
Water chemistry Selected chemical variables
Phytoplankton Chlorophyll a
Trace elements Al, As, Cd, Cu, Hg,
Se (water)
As, Cd, Cu, Hg, Se
(sediment and fish)
ANOVA, block on month Station
ANOVA, block on month Station
ANOVA, block on month Station
ANOVA, block on month Station
ANOVA Transect
'Parametric and non -parametric (rank) one-way Analysis of Variance (ANOVA) statistical models were
used. A Type I error rate of 5% (a = 0.05) was used to judge the significance of all tests. Fisher's
protected least significant difference (LSD) test was applied to determine where differences in
means occurred for significant ANOVA models.
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Environmental Monitoring Results for 2017-2018
Limnology
Temperature and Dissolved Oxygen
• Thermal stratification, defined by changes of at least 2°C per meter of water depth, in Hyco Reservoir
was influenced by several factors during 2017 and 2018, including proximity to the plant discharge,
variable thermal loading from power plant discharges, summertime use of the auxiliary intake system,
and natural ambient conditions and streamflow (Appendices 1 and 2). In Southeastern reservoirs,
typically, a pronounced clinograde isotherm (thermocline) is observed throughout hotter months.
However, this pronounced thermal stratification pattern was not observed in Hyco Reservoir during
2017 and 2018, in keeping with historical observations. In 2017, no thermal stratification was present
in the reservoir during February, August, and December while only weak thermal stratification was
observed during April, June, and October. Similarly, during 2018, no thermal stratification was
observed during February and October and again, only weak thermal stratification was observed
during April, June, August and December. Surface water temperatures at Station D2 near the thermal
discharge ranged from 11.3°C in February to 30.6°C in October 2017 (Appendix 3). In 2018, Station
D2 ranged from 11.8 in February to 31.8 in August (Appendix 4). The coolest surface water
temperature in the reservoir during 2017 was 8.5°C in February at Station SHHW1 and 8.0 during
February at Station C2 during 2018.
• The annual mean surface temperature at Station D2 was 23.4°C in 2017 and 22.6 in 2018
(Appendices 3 and 4). There were no significant differences in the annual mean surface temperatures
among all sampling stations either year, which is a departure from historical temperature patterns in
the reservoir. It is likely that lower power plant dispatch rates each year resulted in the similarities of
mean temperature measures throughout each year.
• All surface water dissolved oxygen concentrations were greater than 5 mg/L throughout Hyco
Reservoir during both 2017 and 2018 monitoring events (Appendices 1 and 2). Oxygen depletion
below 1 mg/L was observed in only the deeper hypolimnetic waters (typically below approximately 5
meters) of the reservoir during June and October of 2017 and June, August, and October of 2018.
This phenomenon usually occurs within monomictic reservoirs of the southeastern United States.
However, Hyco Reservoir does not exhibit strong oxygen depletion as with other reservoirs of the
southeast due to the use of an auxiliary intake for withdrawal of hypolimnetic cooling water by the
Roxboro Plant.
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Water Clarity Constituents
• Secchi disk transparency was similar among all stations in Hyco Reservoir during 2017 (Appendix 3),
however, minor statistical differences among the stations were noted during 2018 (Appendix 4).
Hyco Reservoir was moderately clear both years with Secchi disk visibility greater than one meter on
average except for the extreme upstream Station SHHW L Mean turbidity values, a related measure
of clarity, were also statistically similar among the reservoir stations during both 2017 and 2018. The
2017-2018 turbidity ranges were within ranges observed in previous years (DEP 2017).
Nutrients and Phytoplankton Biomass
• All aqueous nitrogen constituents during 2017-2018 including annual mean total ammonia, total
nitrogen, nitrite -nitrate nitrogen, and total kjeldahl nitrogen concentrations were similar among the
stations and varied by relatively small amounts (Appendices 3 and 4). These minor variations of
nutrient concentrations among the stations were not considered to be important to the trophic status of
the reservoir. Total phosphorus was also similar among the stations during 2017, however, varied
statistically during 2018 among the stations throughout the reservoir total organic carbon (TOC)
concentrations were low and consistent throughout the reservoir. Taken altogether, the nutrients and
TOC reflect the moderate trophic status of Hyco Reservoir (NCDEQ 2015).
• The annual mean chlorophyll a (a measure of phytoplankton biomass) concentration at Station D2
was statistically less than the concentrations at Stations B2, C2, and F2 during 2017 (Appendix 3).
During 2018, the annual mean chlorophyll a measurement at Station C2 statistically greater than that
at Station F2 but was similar to the mean concentrations at the remaining locations (Appendix 4).
Chlorophyll a was not measured at SHHW 1 as part of the monitoring plans. All chlorophyll a
measurements in Hyco Reservoir during 2017-2018 were below the North Carolina water quality
standard of 40 µg/L (15A NCAC 02B.0211, June 2019).
Ions, Hardness, Total Dissolved Solids, and Specific Conductance
• The annual mean concentrations of most of the major ions, specific conductance (magnitude), total
dissolved solids, and total hardness varied statistically among sampling stations during 2017 and 2018
(Appendices 3 and 4). These constituents generally followed a decreasing pattern in concentration
with the following order D2—F2>B2>3C2>SHHW1. The concentration and magnitude pattern has
been typically observed since the FGD operations commenced in 2008. Over a 10-year period from
2009-2018, fluctuations in concentration of select constituents observed throughout the reservoir
reflected various influencing hydrodynamic processes (i.e., inflow, vertical circulation, turnover) and
the inconsistent dispatching (i.e., discharge mass) of the Roxboro Plant (Appendices 5-10).
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Alkalinity and PH
• The annual mean total alkalinity concentrations during 2017 were similar among all the stations on
Hyco Reservoir with overlapping concentration ranges (Appendix 3). Individual values ranged from
17 to 38 mg/L in surface waters with the greatest measured value at Station SHHW1. During 2018,
the total alkalinity concentrations varied statistically among the stations but these variations were
considered to be minor and of no biological importance (Appendix 4). The individual values ranged
from 23 to 37 mg/L during 2018. Waters less than 40 mg/L are considered to be soft waters (unrelated
to hardness) for biological purposes in terms of productivity (Boyd 1979). These alkalinity
concentrations coincide with the moderate trophic status of Hyco Reservoir.
• Hyco Reservoir generally exhibited annual median pH values slightly above neutral in most cases
with circumneutral ranges within approximately one pH unit of neutral throughout the reservoir
longitudinally and vertically during both 2017 and 2018 (Appendices 1-4). While no statistical
evaluations of pH for 2017 and 2018 were run, which would be inappropriate for log scale data,
annual median values both years were tightly grouped within a few tenths decimal fractions of each
other at the stations. Individual surface water pH values ranged from 6.8 at Station SHHW 1 to 8.9 at
Station C2 during 2017 and 7.0 at both Stations F2 and SHHW 1 to 8.7 at Station C2 during 2018.
Deeper waters of the reservoir generally displayed slightly decreasing pH values from surface waters
to bottom waters, reflecting different biological and limnological processes with depth.
Trace Elements
Arsenic
• Annual mean total arsenic concentrations at Station D2 and F2 were statistically greater compared to
the concentrations at the upper reservoir Station SHHW1 during 2017 (Appendix 3). Stations B2 and
C2 annual mean concentrations were intermediate and statistically similar to all other stations
throughout the reservoir. During 2018, a similar pattern was observed with the annual means at D2
and F2 being greatest in concentration among the stations (Appendix 4). While the lower reservoir
total arsenic concentrations had slightly elevated concentrations during both years due to the Roxboro
Plant FGD operations, all of the arsenic values measured in surface waters at all stations were well
below the North Carolina surface water quality 02B standard for human health (10 µg/L; fish
consumption). Long-term (10-year) trends of arsenic concentrations from 2009-2018 at all stations
exhibited small seasonal fluctuations in concentrations.
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
• The 2017 annual mean arsenic concentration in the sediments at Transect D near the Roxboro Plant
discharge was within concentration range considered to be background (3-13µg/g dry weight) but the
2018 annual mean concentration was elevated slightly above the background concentration range
(Forstner and Wittmann 1981; Salomons and F6rstner 1984; and Martin and Hartman 1984)
(Appendices 11 and 12). At Transect C during 2017, the annual mean arsenic concentration of 6.2
µg/g was below the Laboratory Reporting Limit (LRL) for that year. In 2018, the annual mean
arsenic concentration from samples collected at Transect C was 5.0 µg/g, again within the range of
background concentrations. Comparing the 2018 sediment concentrations by location showed
significant statistical differences. This pattern of arsenic in sediments continues that observed
historically in the reservoir (DEP 2017).
• The annual mean arsenic concentration in Largemouth Bass at Transect D was statistically greater
compared to the Transect C mean concentration during 2017 (Appendix 11). However, these mean
values were only a decimal fraction different when compared, and, when converted to wet weight
values they were below the EPA recreational fisherman screening level (i.e., 1.2 µg/g wet weight) for
human consumption (NCDENR 2013). Mean concentrations in White Catfish and Bluegill were
mostly below the LRL during 2017. Similarly, in 2018 only Largemouth Bass annual mean arsenic
concentrations were statistically different between Transect C and D (Appendix 12). The mean
arsenic values were almost identical at both transects when comparing 2017 and 2018 results for the
three fish species sampled, indicating a consistent concentration pattern. Again, the arsenic values in
2018 were below the EPA recreational fisherman screening level.
Cadmium
• Annual mean cadmium concentrations in sediments and fish tissues at Transect C and D during 2017
were all below the LRL (Appendix 11). In 2018, only sediments measurements for cadmium were
above the LRL (Appendix 12). The annual mean concentration at Transect D near the Roxboro Plant
discharge location was statistically greater than the mean concentration upstream at Transect C.
Copper
• The annual mean total copper concentrations in Hyco Reservoir surface waters were statistically
similar among all stations during both 2017 and 2018 (Appendices 3-9). The values were mostly
below 2.0 µg/L throughout the reservoir.
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
• The annual mean copper concentration in sediment near the power plant discharge (Transect D) was
statistically similar to the mean copper concentration at Transect C (South Hyco Creek arm) during
both 2017 and 2018 (Appendices 11 and 12).
• Copper concentrations in Bluegill, White Catfish, and Largemouth Bass muscle tissues during 2017
were comparable to those in recent years (DEP 2013, 2014, 2016, and 2017), however, the
concentrations measured in Bluegill muscle at Transect D and Largemouth Bass at both Transect C
and D were unexpectedly moderately elevated when compared to those same past years (Appendices
12 and 13). Copper levels in water and sediments at the two locations during 2018 did not suggest a
cause for the observed elevated copper in fish tissues. Even so, the copper concentrations measured
in the fish tissues were not elevated to the point of being biologically important.
Manianese
• Annual mean total manganese concentrations in surface waters of Hyco Reservoir were statistically
similar among all reservoir stations during 2017 but varied statistically during 2018 (Appendices 2-6).
Manganese concentrations ranged widely in the reservoir during both years with the greatest
concentrations observed in surface waters at Station D2 during December of 2017 and Station
SHHW 1 during August of 2018. These observations reflect biogeochemical processes governing
manganese that are variable from year to year and are unrelated to power plant operations.
Mercury
• The annual mean total mercury concentrations in surface waters were statistically similar among all
stations during both 2017 and 2018 (Appendices 3 and 4). Also, all of the individual total mercury
concentrations measured each year throughout the reservoir were below the North Carolina 15A
NCAC 02B water quality standard of 12 ng/L.
• Annual mean mercury concentrations in sediments at Transects C and D were less than the LRL of
3.6 µg/g during 2017 (Appendix 11). In 2018, a change in the laboratory methodology for mercury in
sediments led to valid measurements below 1 µg/g. The mean values were statistically greater at
Transect D compared to transect C during 2018 (Appendix 12). However, mean concentrations
measured at both locations were very low and were not considered to be biologically important.
• Annual mean mercury concentrations in Bluegill muscle tissues were statistically different between
Transect C and Transect D during 2017 and 2018 (Appendices 11 and 12). The mean mercury
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
concentrations in White Catfish and Largemouth Bass were similar between the two locations each
year. Converting the mercury measurements to fresh weight concentrations resulted in all annual
mean and individual measured mercury concentrations in muscle tissues during 2017 and 2018 being
below the North Carolina Health Director's screening value of 0.4 µg/g fresh weight and the EPA's
water quality criterion for methylmercury in fish tissues of 0.3 µg/g fresh weight (NCDENR 2013).
Selenium
• During both 2017 and 2018, the annual mean total selenium concentrations in surface waters of Hyco
Reservoir were statistically similar among all stations, continuing a finding observed in 2016 (DEP
2017) (Appendices 3 and 4). Further, all annual mean selenium concentrations were below 1 µg/L
reservoir -wide, which is well below the North Carolina 15A NCAC 02B water quality standard of 5
µg/L for freshwater.
• During 2017, the mean selenium concentrations in sediments were statistically similar between
Transects C and D while in 2018, the mean selenium concentrations were statistically greater at
Transect D than at Transect C (Appendices 11 and 12). All mean selenium concentrations in the
muscle tissues of Bluegill, White Catfish, and Largemouth Bass were statistically greater at Transect
D near the power plant discharge compared to upstream at Transect C during 2017. During 2018, the
mean concentrations in Bluegill muscle were significantly greater at Transect D compared to Transect
C. No differences in selenium concentrations of muscle tissue from White Catfish and Largemouth
Bass were noted in 2018. The selenium concentrations in the three species continued to trend lower
at Transect D since approximately 2013 (Appendix 13). All the selenium values (converted to wet
weight concentrations) in edible flesh during 10-year observation period from 2009 through 2018,
were well below the North Carolina human health consumption advisory level (10 µg/g wet weight).
Thallium
• All thallium measurements were below the LRL of 0.1 µg/L during 2017 and 2018 (Appendices 3-6).
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Fisheries
Fish Species Composition
• There were 24 fish species in 2017 and 21 fish species in 2018, belonging to seven families, collected
from Hyco Reservoir with electrofishing (Appendix 14). As a whole, the sunfish family
(Centrarchidae) dominated the fish population with six fish species present in the reservoir both years.
The bullhead catfishes (Ictaluridae), minnows (Cyprinidae) and Catostomidae (suckers) traded with
each other in number of species between 2017 and 2018. The fish assemblage observed in Hyco
Reservoir was typical of piedmont impoundments in the Southeast. Largemouth Bass was the
primary apex predator in the reservoir both years and Black Crappie and Channel Catfish were also
prevalent predators during 2017 and 2018. Yellow Perch were collected in reasonably good numbers.
The open water schooling species Gizzard Shad and Threadfin Shad were abundant in Hyco
Reservoir providing ample forage for the predator species during 2017 and 2018.
• As with most man-made reservoirs, the fish assemblage in Hyco Reservoir consisted of species
considered widely distributed and common in the Southeastern United States except for introduced
species including Blue Tilapia and Threadfin Shad (Appendices 15 and 16). The presence of these
introduced species in Hyco Reservoir was unrelated to the operation of the Roxboro Plant except for
the heated effluent which allowed for their overwintering. Blue Tilapia, in particular, are likely to
decline in numbers due to their intolerance of cold water temperatures as the Roxboro Plant continues
to be dispatched at lower rates. Threadfin Shad may also be somewhat affected due to their
intolerance of long-term exposure to low temperatures (Strawn 1965). The remaining fish species in
Hyco Reservoir were either indigenous or typically found in piedmont reservoirs of North Carolina.
• The greatest number of fish species was observed at Transect C both years with 19 species during
2017 and 16 species during 2018 (Appendices 15 and 16). The Transects followed a pattern of
species richness both years as follows: C>B>A>D=F. Transects D and F had the lowest species
richness likely due to limited shoreline habitat with more open water areas.
Fish Abundance, Distribution, and Size Structure
• Centrarchidae (sunfishes) were the most the abundant fish group in Hyco Reservoir followed in order
by Clupeidae (herrings), Ictaluridae (bullhead catfishes), Cyprinidae (minnows), Catastomidae
(suckers), Percidae (perches), and Cichlidae (tilapia) during 2017 and 2018 (Appendix 14). The
sunfish family comprised 78% of the total annual electrofishing catch in 2017 and 88% total annual
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
electrofishing catch in 2018. Herrings comprised 15% and 8% of the total fish catch while bullhead
catfishes comprised 2% both years of the total fish catch during 2017 and 2018, respectively.
• Bluegill was the single most abundant fish species present with 53% of the total catch during 2017
and 70% during 2018 (Appendix 14). Largemouth bass was the second most abundant fish species
during both 2017 and 2018 with 13% and 10% of the total fish numbers and comprising 33% and
46% of the of the total biomass, respectively. Gizzard Shad was the third most abundant species with
9% during 2017 and 5% during 2018 of the total catch each comprising 16% and 11% of the total
biomass. Total fish number and biomass reservoir -wide during 2017 and 2018 were consistent with
values observed in recent years (DEP 2017).
• Bluegill were most abundant based on electrofishing at Transects A (Cobbs Creek) and D during
2017 and at Transect B during 2018 (Appendix 15 and 16). The mean Bluegill electrofishing catch
by transect arranged in approximate decreasing order were Transects A>D>C>F>B during 2017.
During 2018, the mean Bluegill catch in approximate decreasing order was B>D>A>C>F.
• As in previous years (DEP 2017), Bluegill reproduction continued be good throughout the reservoir in
both 2017 and 2018 as indicated by their length -frequency distributions at all transects, except at
Transect B during 2017 (Appendices 17 and 18). Transect B is characterized as large flat open areas
with little cover for hiding from predators and likely the reason for fewer small Bluegill (< 80 mm)
being collected. Also, there is a limited amount of shoreline rip rap habitat in shallow areas of this
transect that can provide cover as well, therefore, small fish may be under represented annually in the
electrofishing catch. The size class distributions of Bluegill were similar among all transects except
at Transect B during 2017 where most fish were greater than 75 mm. This pattern of fewer small
Bluegill at Transect B is typical of the electrofishing catches at this reservoir location (DEP 2017).
However, in a departure from past monitoring, the electrofishing catch from 2018 at Transect B
exhibited a reasonably large number of smaller Bluegill. The appearance of many smaller individuals
is not understood completely but could suggest changes to the habitat (e.g., possible vegetation
growth) that are not apparent from the reservoir surface.
• The mean Relative Weight (Wr) values, which is an indirect measure of health condition, reservoir -
wide were 83 during both 2017 and 2018, respectively (Appendices 23 and 24). A Wr of 100 is
optimal for a species and suboptimal Wr values, in the absences of diseases or other health related
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
factors, may be related to competition for food and the mesotrophic status of Hyco Reservoir for this
numerically dominant species. Most fish do not achieve optimal condition in natural settings.
• Largemouth Bass of all size classes were well -represented throughout the reservoir during 2017 and
2018 (Appendices 15 and 16). Adequate reproductive success was noted both years as represented by
the presence of reasonable numbers of individual fish less than 150 mm at most transects. Transect D
near the power plant discharge had the most smaller fish present in electrofishing catches during 2017
while Transect A had the most in 2018. The average size of Largemouth Bass was consistent
throughout the reservoir within year and between years having an overall reservoir mean length of
267 mm for 2017 and 251 mm for 2018.
• The mean Wr for Largemouth Bass in Hyco Reservoir during 2017 (Wr =85) was slightly lower than
the mean Wr during 2018 (Wr=89) (Appendices 23 and 24). Again, the productivity level for the
reservoir as a mesotrophic system is probably one of the main influences of suboptimal condition of
fish, particularly an apex predator such as Largemouth Bass.
• Gizzard Shad were well represented and collected in similar numbers throughout Hyco Reservoir
during both years except at Transect F during 2018, where the numbers were somewhat lower
(Appendices 15 and 16). Consistent with previous years, Gizzard Shad collected from the reservoir
were mostly greater than 200 mm each year. Generally, young -of -year Gizzard Shad are not
efficiently collected by electrofishing due to the inherent geartype bias against smaller schooling fish.
However, occasionally, schools of small Gizzard Shad are encountered during electrofishing
sampling such as occurred at Transect C during 2018. This event illustrates the random nature of
encountering a large school of small shad at a particular location while sampling. It is likely that
isolated schools like this are randomly located throughout Hyco Reservoir but are seldom
encountered.
• The mean Wr values of 88 and 92 for Gizzard Shad in Hyco reservoir during 2017 and 2018,
respectively, were considered to be reasonably good in terms of health condition (Appendices 23
and 24). This factor along with good numbers collected throughout the reservoir, as noted above,
represents a substantial prey base for predator species and a basic sustainability requirement of
aquatic communities.
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
• Redear Sunfish was reasonably well distributed throughout Hyco Reservoir during 2017 and 2018
(Appendices 15 and 16). Green Sunfish was more abundant downstream of the power plant discharge
while Yellow Perch, Black Crappie, and Satinfin Shiner were collected in greater numbers upstream
of the plant during each year.
Balanced, Indigenous Community
• Hyco Reservoir represents a balanced, self-sustaining community. To demonstrate balance, an aquatic
population/community must contain both predator and prey species in relative balanced numbers to
each other reflecting the overall trophic status of the system. Both fish groups must be reproducing
and recruiting adequately to produce the proper balance. Several regionally common predator species
including adult Largemouth Bass, Black Crappie, and Channel Catfish continued to exist in Hyco
Reservoir during 2017 and 2018 (Appendices 14-17). The apex predator Largemouth Bass, an
integral part of the aquatic community, exhibited both adequate reproduction and recruitment for a
self-sustaining population based on the presence of sufficient numbers of young -of -year (generally <
150 mm fish) and year class 1+ fish (generally > 150 mm to 250 mm fish) throughout the reservoir.
Many forage species existed throughout the reservoir as well, including the primary prey species
Bluegill and sustaining prey species Gizzard Shad and Threadfin Shad. Bluegill exhibited the
necessary presence of young -of -year (generally < 80 mm fish) and year class 1+ fish (generally > 80
mm to 125 mm fish) (Appendices 17 and 18). Gizzard Shad and Threadfin Shad were also present in
the reservoir with good numbers of adult fish each year. Without adequate reproduction and
recruitment of this prey species, the adult shad would not continue to be present in similar numbers
compared to previous years. Also, as noted above, a random encounter with a large school of small
Gizzard Shad at Transect C during 2018 supports the likelihood of adequate reproduction recruitment
of this species in the reservoir.
• Fish populations in good balance can indicated by comparing the Proportional Size Distribution
(PSD) index values of select predator and prey species. PSD values for balanced populations of
Largemouth Bass range from 40 to 70 and for Bluegill from 20 to 60 (Gabelhouse 1984). In Hyco
Reservoir, a balanced population for Largemouth Bass population during 2017 and 2018 existed in
the reservoir while Bluegill population was balanced in 2017 but fell out of the range for balanced
populations during 2018 (Appendix 25). No balance range has been determined for Gizzard Shad
populations but plotting the PSD values for both Largemouth Bass and Gizzard Shad during 2017 and
2018 shows an interesting relationship of the stock and quality size fish of each species in Hyco
Duke Energy Progress 18 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Reservoir.
Fish Community Health
• No significant disease or pathological anomalies were observed in fish collected by Company
Biologists during 2017 or 2018. Winter kills of tilapia were observed in both 2017 and 2018 but were
expected with the low dispatch of the Roxboro Plant. No other fish kills were observed or reported
from Hyco Reservoir during 2017 and 2018.
Biofouling Monitoring
• No zebra mussels (Dreissena polymorpha) or quagga mussels (D. bugensis) were found in Hyco
Reservoir during 2017 and 2018. These mussels are potentially serious biofouling organisms to power
plant operations. Neither species has been collected from Hyco Reservoir. Asiatic clams (Corbicula
fluminea) are known to exist in Hyco Reservoir as in many other Southeastern reservoirs; however,
no significant power plant operational issues have been caused by their presence.
Summary and Conclusions
Hyco Reservoir thermal stratification patterns and water temperature extremes continued to be
dependent on the local meteorological conditions, the proximity to the discharge canal outfall area,
the influence of the circulating water of the auxiliary intake system, and the inverted siphon (part of
the old discharge canal to Cobbs Creek) on the South Hyco Creek arm of the reservoir during 2017
and 2018. The 2017-2018 annual mean reservoir temperatures in surface waters continued to be
within the ranges typically observed in Hyco Reservoir.
Despite low dispatch of the Roxboro Plant, FGD system operations continued to affect several
water chemistry parameters nearer the power plant discharge compared to those at historical
background stations in Hyco Reservoir during 2017 and 2018. However, concentrations of a number
of constituents have decreased with decreasing FGD discharges over the last several years.
In fish tissues, selenium concentrations continued to trend down in Bluegill, White Catfish, and
Largemouth Bass in both 2017 and 2018. The edible flesh selenium concentrations of all fish species
sampled remained well below the North Carolina consumption advisory level of 10 µg/g wet weight
(50 µg/g dry weight).
Fish species composition, abundance, and distribution in Hyco Reservoir during 2017 and 2018
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
were similar to that of previous years. Bluegill remained the dominate fish species followed by
Largemouth Bass, Gizzard Shad, Redear Sunfish, and Black Crappie within the reservoir both years.
The fish community tended to be slightly less diverse in the open -water habitat of the middle and
downstream portions of the reservoir compared to the upper, riverine-like areas of Hyco Reservoir.
Hyco Reservoir, a man-made water body, contained a fish community that was balanced, and self-
sustaining, which indicates a balanced aquatic community characteristic of a mesotrophic piedmont
impoundments located in Southeastern United States.
References
APHA. 2012. Standard methods for the examination of water and wastewater. 22th Ed. American
Public Health Association, Washington, DC.
Boyd 1979. Water quality in warmwater fish ponds. Agricultural Experiment Station, Auburn
University, Aurburn, AL.
CP&L. 1991. Roxboro Steam Electric Plant 1990 environmental monitoring report. Carolina Power &
Light Company, New Hill, NC.
2001. Roxboro Steam Electric Plant 2000 environmental monitoring report. Carolina Power &
Light Company, New Hill, NC.
DEP. 2013. Roxboro Steam Electric Plant 2012 environmental monitoring report. Duke Energy Progress,
Raleigh, NC.
DEP. 2014. Roxboro Steam Electric Plant 2013 environmental monitoring report. Duke Energy Progress,
Raleigh, NC.
DEP. 2016. Roxboro Steam Electric Plant 2014-2015 environmental monitoring report. Duke Energy
Progress, Raleigh, NC.
DEP. 2017. Roxboro Steam Electric Plant 2016 environmental monitoring report. Duke Energy Progress,
Raleigh, NC.
Duke Energy Progress 20 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Gabelhouse, D. W., Jr. 1984. A length -categorization system to asses fish stocks. N. Amer. J. Fish.
Manag. 4:371-3 84.
North Carolina Administrative Code. 2019. Title 15A NACA 02B Water Quality Standards for Surface
Waters. June 10, 2019.
NCDENR. 2013. Standard Operating Procedures; Fish Tissue Assessments. North Carolina Department
of Environment and Natural Resources. Intensive Survey Branch. Raleigh, NC.
NCDEQ. 2015. Roanoke River basinwide assessment report. North Carolina Department of
Environmental Quality. Intensive Survey Branch. Raleigh, NC.
Page, L. M., H. Espinsoa-P6rez, L T. Findley, C. R. Gilbert, R. N. Lea, N. E. Mandrak, R. L. Mayden,
and J. S. Nelson. 2013. Common and scientific names of fishes from the United States, Canada,
and Mexico. 7th edition. American Fisheries Society, Special Publication 34, Bethesda, Maryland.
PEC. 2008. Roxboro Steam Electric Plant 2007 environmental monitoring report. Progress Energy
Carolinas, Raleigh, NC.
Salomons, W., and U. Forstner. 1984. Metals in the hydrocycle. Springer-Verlag, New York, NY.
Strawn, K. 1965. Resistance of Threadfin Shad to low temperatures. Proceedings of the Annual
Conference Southeastern Association of Game and Fish Commissioners 17(1963):290-293.
USEPA. 1979. Methods for the chemical analysis of water and wastes. U.S. Environmental
Protection Agency, EPA-60/4-79-020, Cincinnati, OH.
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 1. Depth profiles of the water temperature (IC), dissolved oxygen (mg/L), pH, and
specific conductance (µS/cm) at Hyco Reservoir during 2017.
Depth B2
0.2 10.3
1.0 8.7
2.0 8.6
3.0 8.6
4.0 8.6
5.0 8.5
6.0 8.5
7.0 8.7
8.0
9.0
10.0
11.0
Depth
0.2
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
Depth
0.2
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
B2
19.4
17.9
17.3
15.8
14.9
14.2
14.2
B2
28.1
28.1
27.9
27.8
27.0
26.1
24.5
23.1
Temperature
C2
D2
F2 SHHWI
8.8
11.3
10.3 8.5
8.6
11.1
10.2 7.3
8.1
11.1
10.0 7.0
8.0
11.1
9.8 6.8
8.0
11.1
8.0
11.1
8.0
11.0
7.9
11.0
10.9
10.9
10.9
10.9
Temperature
C2
D2
F2
SHHWI
21.6
23.9
21.7
21.5
19.1
22.6
20.3
19.4
17.5
21.3
19.7
18.2
16.7
20.4
18.8
16.9
16.0
17.6
15.4
17.6
15.3
16.5
15.3
15.9
15.6
15.3
15.1
Temperature
C2
D2
F2
SHHWI
27.9
30.4
29.4
28.0
27.9
30.1
29.2
27.0
27.4
29.6
28.7
26.5
26.4
29.4
28.6
25.6
25.3
28.9
23.0
27.4
19.9
26.7
19.5
23.6
21.6
18.5
17.2
February 1, 2017
Dissolved oxygen
pH
Specific conductance
B2
C2
D2
F2
SHHWI
B2
C2
D2
F2
SHHWI
B2
C2
D2
6B SHHWI
10.2
9.2
10.2
10.8
10.6
7.2
7.0
7.4
7.6
7.3
115
75
179
179
83
9.5
9.1
10.1
10.7
10.7
7.1
7.0
7.4
7.6
7.2
109
74
180
179
83
9.4
9.2
10.1
10.4
10.2
7.1
7.0
7.4
7.5
7.2
108
74
180
179
83
9.4
9.1
10.1
10.3
10.1
7.1
7.0
7.4
7.5
7.2
107
74
180
179
85
9.4
9.1
10.1
7.1
7.0
7.4
106
74
180
9.3
9.1
10.1
7.1
7.0
7.4
103
74
180
9.3
9
10.1
7.1
7.0
7.4
102
74
180
9.2
9
10.1
7.1
7.0
7.4
102
74
180
10
7.4
181
10
7.4
181
10
7.3
181
9.9
7.3
181
April 28, 2017
Dissolved oxygen
pH
Specific conductance
B2
C2
D2
F2 SHHWI
B2
C2
D2
F2
SHHWI
B2
C2
D2
F2
SHHWI
8.7
8.7
7.5
8.8 8.2
7.2
6.9
6.9
7.1
6.8
75
70
147
143
77
7.9
7.9
7.4
8.2 7.4
6.8
6.7
6.9
7.0
6.7
62
68
138
140
77
7.8
7.7
7.4
7.7 6.5
6.7
6.7
6.8
7.0
6.6
55
64
129
144
73
7.7
7.2
7.4
7.2
6.5
6.6
6.9
6.9
6.5
46
64
127
150
70
7.5
6.9
7.4
6.2
6.5
6.8
43
63
110
7.5
6.7
7.4
6.1
6.5
6.8
43
62
109
7.2
7.0
7.5
6.0
6.4
6.8
43
62
95
6.7
7.5
6.4
6.7
62
84
7.4
6.7
82
7.3
6.6
73
6.8
6.5
67
June 27, 2017
Dissolved oxygen
pH
Specific conductance
B2
C2
D2
F2 SHHWI
B2
C2
D2
F2
SHHWI
B2
C2
D2
F2
SHHWI
8.7
10.0
7.5
7.7
9.3
8.3
8.5
7.4
7.5
7.8
113
73
125
130
75
8.7
10.0
7.2
7.5
8.8
8.3
8.4
7.3
7.4
7.5
113
73
124
130
74
8.6
9.0
6.4
7.2
6.8
8.2
8.0
7.1
7.3
6.9
112
72
124
129
83
8.6
4.2
6.0
6.9
2.7
8.2
6.6
7.0
7.2
6.6
109
69
123
130
92
5.7
0.5
5.1
7.1
6.3
6.9
100
68
121
1.9
0.4
3.8
6.7
6.4
6.7
92
75
112
0.5
0.4
3.2
6.6
6.6
6.7
89
122
109
0.4
0.4
0.6
6.7
6.6
6.5
89
129
98
0.4
6.5
96
0.4
6.8
130
0.4
6.9
144
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Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 1. (continued)
August 29, 2017
Temperature
Dissolved oxygen
pH
Specific conductance
Depth
B2 C2
D2
F2
SHHW1
B2
C2
D2
F2 SHHW1
B2
C2
D2
F2
SHHW1
B2
C2
D2
F2
SHHW1
0.2
27.4 26.6
27.9
27.6
24.7
7.1
6.4
6.8
6.7 7.4
7.4
7.2
7.3
7.3
7.4
175
118
206
180
105
1.0
27.4 26.2
27.9
27.6
24.7
7.1
6.3
6.8
6.6 7.3
7.4
7.2
7.3
7.3
7.3
175
118
206
180
105
2.0
27.4 26.2
27.9
27.6
24.7
7.1
6.3
6.7
6.6 7.1
7.4
7.2
7.3
7.3
7.3
175
118
206
180
105
3.0
27.4 26.2
27.8
26.8
7.1
6.3
6.7
6.6
7.4
7.2
7.3
7.3
175
118
207
179
4.0
27.4 26.2
27.8
7.1
6.3
6.7
7.4
7.2
7.3
175
118
207
5.0
27.3 26.1
27.8
7.1
5.9
6.7
7.4
7.1
7.3
174
118
207
6.0
27.0
27.8
6.9
6.7
7.3
7.3
174
207
7.0
27.7
6.8
7.3
211
8.0
27.7
6.8
7.3
211
9.0
27.8
6.8
7.3
209
10.0
27.6
6.8
7.3
213
October 11, 2017
Temperature Dissolved oxygen
Depth
B2
C2
D2
F2
SHHW1
B2
C2
D2
F2
SHHW1
B2
C2
0.2
26.2
26.7
30.6
27.3
26.3
9.4
10.6
7.0
8.4
9.8
8.3
8.9
1.0
26.1
25.8
30.1
26.6
24.4
9.4
10.8
6.9
8.3
10.0
8.4
8.9
2.0
25.7
24.4
29.5
26.4
22.8
9.2
8.6
6.9
7.8
1.5
8.3
8.1
3.0
25.1
23.3
28.5
26.2
8.2
5.7
7.0
7.1
7.8
7.6
4.0
24.5
22.6
26.3
7.2
1.8
6.8
7.5
7.1
5.0
23.7
22.1
25.8
3.7
0.3
6.5
7.0
7.1
6.0
23.5
25.6
2.3
5.7
6.9
7.0
24.8
4.3
8.0
24.2
3.3
9.0
23.6
2.0
10.0
23.5
0.5
Temperature
Depth
B2
C2
D2
F2
SHHW1
0.2
12.8
11.2
16.1
14.5
10.6
1.0
12.8
11.2
16.1
14.5
10.6
2.0
12.8
11.1
16.1
14.5
10.5
3.0
12.7
11.0
15.7
14.5
10.5
4.0
12.5
10.7
15.4
5.0
12.3
10.7
15.4
6.0
11.9
15.2
7.0
15.2
8.0
15.0
9.0
14.0
10.0
13.3
December 6, 2017
Dissolved oxygen
B2
C2
D2
F2 SHHW1
B2
10.2
10.3
8.1
9.4 11.0
7.5
10.2
10.3
8.1
9.3 10.9
7.5
10.2
10.3
8.0
9.2 10.8
7.5
10.1
10.1
7.4
9.2 10.9
7.5
9.5
9.4
7.4
7.3
8.9
9.4
7.4
7.2
7.5
7.3
7.1
7.2
6.9
6.3
5.1
pH Specific conductance
D2 F2 SHHW1 B2 C2 D2 F2 SHHW1
7.7
8.0
8.5
199
144
214
206
122
7.6
7.9
8.6
199
142
212
206
122
7.6
7.8
7.2
199
148
210
206
137
7.6
7.6
197
146
208
205
7.5
194
140
206
7.4
194
144
205
7.4
194
203
7.2
200
7.1
200
7.0
200
7.2
204
pH Specific conductance
C2 D2 F2 SHHW1 B2 C2 D2 F2 SHHW1
7.3 7.2 7.4 7.6 204 175 217 208 159
7.3 7.2 7.4 7.5 204 175 216 208 159
7.3 7.2 7.4 7.5 204 175 216 208 157
7.2 7.1 7.4 7.5 204 172 213 208 158
7.1 7.1 202 172 211
7.1 7.1 202 172 211
7.1 196 210
7.0 210
7.0 209
7.0 206
7.0 204
Duke Energy Progress 23 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 2. Depth profiles of the water temperature (IC), dissolved oxygen (mg/L), pH, and
specific conductance (µS/cm) at Hyco Reservoir during 2018.
Depth B2
0.2 9.7
1.0 9.7
2.0 9.6
3.0 9.6
4.0 9.5
5.0 8.5
6.0 7.7
7.0 7.4
8.0
9.0
10.0
Depth
0.2
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
Depth
0.2
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
B2
15.8
13.0
12.7
10.3
11.9
11.1
10.8
10.8
B2
27.9
27.9
27.7
27.5
26.8
25.9
24.5
23.4
Temperature
C2
D2
F2
SHHW1
8.0
11.8
12.6
9.1
8.0
11.8
12.7
9.1
8.0
11.8
12.7
9.0
8.0
11.8
12.0
7.6
7.9
11.8
7.6
11.8
7.6
11.7
7.5
11.7
11.6
11.4
11.1
Temperature
C2
D2
F2
SHHW1
14.8
14.8
14.8
17.2
14.8
14.1
14.8
16.1
13.0
14.0
14.6
13.1
11.2
13.3
14.4
11.5
10.7
13.1
10.3
13.0
10.1
12.9
12.7
12.6
12.3
11.8
Temperature
C2
D2
F2
SHHW1
28.8
28.8
29.5
27.9
27.6
28.5
28.7
26.9
26.8
27.8
28.4
26.2
26.0
27.6
28.2
24.9
22.7
27.5
18.9
27.0
16.8
25.4
16.4
22.6
19.9
17.1
16.0
February 13, 2018
Dissolved oxygen
pH
Specific conductance
B2
C2
D2
F2
SHHW1
B2
C2
D2
F2 SHHW1 B2
C2
D2
F2
SHHW1
11.1
11.0
10.2
10.7
10.6
7.4
7.1
7.4
7.5
7.0 210
127
260
256
107
11.1
10.9
10.1
10.4
10.5
7.4
7.1
7.4
7.5
7.0 208
126
260
256
106
11.0
10.8
10.1
10.3
9.9
7.3
7.1
7.3
7.5
7.0 140
127
260
256
107
11.0
10.7
10.0
10.1
8.8
7.3
7.1
7.3
7.4
6.9 175
126
260
255
112
10.9
10.5
10.0
7.3
7.1
7.3
159
127
260
10.4
9.8
10.0
7.2
7.1
7.3
119
127
260
10.2
9.9
10.0
7.1
7.1
7.3
120
128
260
10.1
10.1
10.0
7.1
7.1
7.3
106
131
259
9.9
7.3
257
9.8
7.3
253
9.7
7.2
249
April
2, 2018
Dissolved oxygen
pH
Specific
conductance
B2
C2
D2
F2
SHHW1
B2
C2
D2
F2
SHHW1
B2
C2
D2
F2
SHHW1
12.6
11.4
11.1
11.4
12.5
8.3
8.0
7.7
8.0
8.4
118
NA
237
238
86
11.2
11.9
11.0
11.5
12.4
7.4
7.8
7.7
8.0
8.2
113
82
237
238
87
11.0
10.7
10.9
11.4
10.2
7.4
7.3
7.7
8.0
7.2
112
81
237
239
81
6.8
8.7
10.0
10.9
7.2
6.8
7.0
7.4
7.7
6.9
83
85
232
239
81
10.3
7.6
9.8
7.3
6.9
7.4
147
84
231
9.5
6.7
9.7
7.2
6.8
7.3
130
83
230
8.6
6.2
9.5
7.1
6.8
7.3
121
83
229
8.6
9.4
7.1
7.3
121
226
9.2
7.3
223
8.9
7.2
219
7.9
7.1
220
June 6, 2018
Dissolved oxygen
pH
Specific conductance
B2
C2
D2
F2 SHHW1
B2
C2
D2
F2
SHHW1
B2
C2
D2
F2
SHHW1
8.7
8.4
8.5
8.2
8.7
7.8
7.8
7.8
7.8
7.7
87
152
152
157
87
8.4
8.7
7.5
8.1
8.0
8.1
8.1
7.5
7.8
7.5
134
85
152
156
87
8.1
6.3
5.9
7.8
4.7
8.0
7.2
7.1
7.6
7.0
134
85
150
156
91
7.2
1.9
5.8
6.9
0.9
7.5
6.8
7.1
7.3
6.8
137
88
150
155
100
3.7
0.2
5.7
7.0
6.8
7.1
127
99
150
0.7
0.2
4.6
6.8
6.9
6.9
119
145
145
0.2
0.3
2.2
6.9
6.8
6.8
123
164
131
0.2
0.3
0.3
6.9
6.8
6.6
137
168
116
0.3
6.6
119
0.2
6.8
195
0.2
6.9
220
Duke Energy Progress 24 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 2. (cont.)
August 1, 2018
Temperature
Dissolved oxygen
pH
Specific conductance
Depth
B2
C2
D2
F2
SHHW1
B2
C2
D2
F2
SH11W1
B2
C2
D2
F2
SHHW1
B2
C2
D2
F2
SHHW1
0.2
29.3
29.2
31.8
30.1
29.4
6.7
7.6
7.0
7.6
6.6
7.5
7.8
7.4
7.5
7.4
160
114
186
171
111
1.0
29.3
29.2
31.7
30.0
29.3
6.7
7.6
7.0
7.6
6.5
7.4
7.7
7.4
7.5
7.4
160
114
186
172
111
2.0
29.3
29.1
31.6
29.9
28.8
6.7
7.4
6.8
7.5
4.0
7.5
7.7
7.4
7.5
7.1
160
114
186
173
112
3.0
29.3
28.8
31.5
29.8
28.6
6.7
6.3
6.4
7.5
2.1
7.4
7.3
7.2
7.4
6.9
160
116
185
171
115
4.0
29.3
26.1
30.1
6.6
0.3
4.3
7.4
6.7
7.0
160
148
174
5.0
29.2
22.4
29.6
6.5
0.3
3.1
7.4
6.8
6.8
160
201
170
6.0
28.6
19.1
29.2
0.5
0.4
2.3
6.9
6.5
6.8
159
230
168
7.0
28.1
28.6
0.4
0.8
6.9
6.7
171
163
8.0
27.8
0.2
6.8
166
9.0
24.4
0.3
7.4
218
10.0
20.6
0.3
7.7
267
October 2, 2018
Temperature Dissolved oxygen pH Specific conductance
Depth B2 C2 D2 F2 SHHWl B2 C2 D2 F2 SHHWl B2 C2 D2 F2 SHHWl B2 C2 D2 F2 SHHW1
0.2
26.7
26.7
28.7
27.3
25.6
10.
10.8
6.2
8.5
10.5
8.4
8.7
7.1
7.7
8.4
165
93
175
180
92
1.0
26.6
26.1
28.7
27.2
25.1
10.
10.7
6.4
8.5
10.3
8.5
8.7
7.1
7.6
8.4
165
92
174
179
90
2.0
26.1
25.5
28.5
27.1
24.0
10.
9.8
6.4
8.4
6.9
8.4
8.4
7.1
7.6
7.6
165
92
173
179
92
3.0
25.4
24.5
27.1
26.3
8.3
6.1
3.8
6.3
7.7
7.5
6.9
7.2
162
91
164
177
4.0
25.3
24.1
26.5
8.1
2.5
3.1
7.5
7.1
6.8
157
90
160
5.0
25.2
23.8
25.8
7.8
0.4
1.3
7.4
6.9
6.7
161
107
144
6.0
24.8
25.4
3.0
0.7
7.0
6.6
143
126
7.0
25.2
0.6
6.6
122
8.0
25.0
0.4
6.6
118
9.0
24.6
0.2
6.6
102
10.0
23.9
0.1
6.7
132
Temperature
Depth B2 C2 D2 6B SHHW1 B2
0.2
11.0
8.3
19.6
13.4
8.3
9.8
1.0
11.0
8.3
19.3
13.4
8.3
9.8
2.0
11.0
8.3
19.2
13.4
8.3
9.8
3.0
11.0
8.2
18.0
13.4
8.3
9.8
4.0
10.9
8.1
16.4
9.8
5.0
8.7
8.0
12.6
9.4
6.0
7.7
11.5
8.7
7.0
11.7
8.0
11.3
9.0
9.6
10.0
9.4
December 5, 2018
Dissolved oxygen pH
C2
D2
6B
SHHWl
B2
C2
D2
10.0
8.3
8.2
9.7
7.4
7.2
7.1
10.0
8.2
8.2
9.7
7.2
7.1
7.1
10.0
8.2
8.2
9.7
7.2
7.1
7.1
10.0
8.1
8.2
9.7
7.1
7.0
7.1
10.0
7.8
7.1
7.0
7.0
10.0
7.7
7.0
6.9
6.9
7.7
7.0
6.9
7.8
6.9
6.7
6.9
6.8
6.8
6.8
6.8
Specific conductance
6B
SHHW1
B2
C2
D2
F2
SHHW1
7.0
7.1
94
72
116
108
82
7.0
7.1
94
72
116
108
82
7.0
7.1
94
72
116
108
82
7.0
7.3
94
72
111
108
82
91
72
109
79
73
103
72
102
100
82
81
80
Duke Energy Progress 25 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 3. Means, ranges, and spatial trends of selected limnological variables from surface
waters of Hyco Reservoir during 2017.+ &
Station B2
Station C2
Station D2
Station F2
Station SHHW1
Variable
Mean
Range
Mean
Range
Mean
Range
Mean
Range
Mean
Range
Temperature (°C)
20.7
12.8-28.1
20.5
11.2-27.9
23.4
11.3-30.6
21.8
14.5-29.4
29.9
8.5-28.0
Dissolved oxygen (mg/L)
9.0
7.1-10.2
9.2
6.4-10.6
7.8
6.8-10.2
8.6
6.7-10.8
9.4
7.4-11.0
pH (median value)
7.5
7.2-8.3
7.3
6.9-8.9
7.3
6.9-7.7
7.4
7.1-8.0
7.6
6.8-8.5
Total dissolved solids (mg/L)
109ab
73-145
82ab
47-123
123a
86-153
122a
88-141
74b
59-118
Turbidity (NTU)
19
2-64
17
5-40
8
2-21
5
2-15
15
6-24
Secchi disk transparency (m)
1.3
0.5-1.9
0.7
0.5-1.1
1.5
0.6-2.3
1.6
0.8-2.3
0.7
0.7-0.7
Chlorophyll a (µg/L)
8.5ab
6.3-16
18a
4.8-37
3.9b
1.5-5.1
5.2ab
3.6-7.5
N/A
Nutrients (mg/L)
Ammonia-N
0.01
< 0.01-0.03
0.01
< 0.01-0.03
0.02
< 0.01-0.05
0.01
< 0.01-0.02
< 0.01
N/A
Nitrate + Nitrite N
0.04
< 0.02-0.11
0.08
< 0.02-0.26
0.08
< 0.02-0.19
0.05
< 0.02-0.13
0.06
< 0.02-0.23
Total nitrogen
0.31
< 0.12-0.75
0.48
0.28-0.85
0.34
0.21-0.56
0.28
0.12-0.53
0.45
0.28-0.78
Total Kjeldahl Nitrogen
0.20
< 0.10-0.35
0.37
0.23-0.65
0.22
< 0.10-0.41
0.19
0.12-0.25
0.36
0.22-0.51
Total phosphorus
0.043
< 0.005-0.110
0.041
0.022-0.071
0.043
0.006-0.170
0.016
< 0.005-0.035
0.040
0.021-0.063
Total organic carbon (mg/L)
7.1
4.9-10.9
6.8
4.9-8.5
5.8
4.6-6.9
5.8
4.6-7.4
7.0
5.1-8.3
Ions (mg/L)
Calcium
13ab
6.4-19
10 b
5.7-16
16a
10-20
16ab
11-19
9b
6.3-15
Chloride
19ab
6.0-30
job
3.0-23
25a
14-32
24a
15-31
8.1b
2.9-20
Magnesium
5.9ab
3.1-8.2
4.3b
2.7-6.9
7.3a
5.0-8.7
7.0a
5.2-8.5
4.ob
2.8-6.4
Sodium
< 5.0
N/A
< 5.0
N/A
< 5.0
N/A
< 5.0
N/A
< 5.0
N/A
Sulfate
14ab
6-20
8.2b
3.8-15.8
l9a
14-22
18a
15-21
7.1b
4.2-13.3
Total alkalinity (mg/L as
25
17-31
26
20-34
26
23-30
26
18-30
29
24-38
CaCO3)
Hardness (mg equiv. CaCO3/L)
57ab
29-81
4 1 b
26-68
71'
46-86
68a
49-83
39b
27-63
Specific conductance(µS/cm)
153ab
75-204
116ab
70-175
182a
125-217
173'
130-208
108b
75-159
Trace elements (µg/L)
Arsenic
1.lab
0.6-1.5
0.8ab
0.4-1.1
1.4a
1.0-1.8
1.4'
0.9-1.7
0.6b
0.3-0.9
Boron
400ab
94-772
192ab
< 50-580
562'
309-838
535a
317-780
127b
< 50-422
Copper
2.1
1.1-4.2
1.7
0.6-2.7
1.7
1.0-2.6
1.6
0.9-2.1
1.3
< 1.0-2.3
Manganese
61
31-96
88
43-143
151
82-276
101
49-210
127
59-200
Mercury§
1.98
< 0.50-9.28
1.51
< 0.50-7.08
1.14
< 0.50-3.32
0.85
< 0.50-2.46
1.17
< 0.50-4.59
Selenium
0.6
< 0.5-1.1
< 0.5
< 0.5
0.7
0.6-1.0
0.7
< 0.5-1.1
< 0.5
N/A
Thallium
< 0.1
N/A
< 0.1
N/A
< 0.1
N/A
< 0.1
N/A
< 0.1
N/A
'Unless otherwise noted, all measurements were taken from the surface. Fisher's protected Least Significant Difference (LSD) test was
applied only if the overall F test for the treatment was significant. Means followed by different superscripts were significantly
different from each other (P = 0.05). The rows where significant differences occurred are shaded. Data were rounded to conform
to significant digit requirements. Rounding may obscure mean differences. The variable pH was reported as a median value and
was not subjected to statistical analysis. Sample size equaled 6 unless otherwise noted. Statistical testing was conducted on surface
water means only. N/A means not applicable and NS means not sampled.
'Less than values (<) indicate the Lower Reporting Limit (LRL) for the variable. The LRL is a statistically determined limit beyond which
chemical concentrations cannot be reliably quantified. Statistical analyses were utilized only when mean concentrations were
above the highest analytical LRL and where LRL values occurred, means were calculated by utilizing one half of the absolute
value of each LRL.
§Mercury was measured in nanograms per liter (ng/L).
Duke Energy Progress 26 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 4. Means, ranges, and spatial trends of selected limnological variables from surface
waters of Hyco Reservoir during 2018.+ &
Station B2
Station C2
Station D2
Station F2
Station SHHW1
Variable
Mean
Range
Mean
Range
Mean
Range
Mean
Range
Mean
Range
Temperature (°C)
20.1
9.7-29.3
19.3
8.0-29.2
22.6
11.8-31.8
21.3
12.6-30.1
21.8
8.3-29.4
Dissolved oxygen (mg/L)
9.9
6.7-12.6
9.9
7.6-11.4
8.6
7.0-11.1
9.1
7.6-11.4
9.8
6.6-12.5
pH (median value)
7.8
7.4-8.4
7.1
7.4-8.7
7.4
7.1-7.8
7.7
7.0-8.0
7.7
7.0-8.4
Turbidity (NTU)
15
3-35
13
5-25
7.3
2.2-22.9
6.1
1.6-23.2
18
10-36
Secchi disk transparency (m)
1.Oab
0.4-1.7
0.8ab
0.5-1.0
1.3ab
0.7-1.9
1.7a
0.7-2.6
0.6b
0.5-0.7
Total dissolved solids (mg/L)
120'
98-155
8lb
73-88
137'
101-175
137'
108-183
84b
72-105
Turbidity (NTU)
15
3-35
13
5-25
7
2-23
6
2-23
18
10-36
Chlorophyll a (µg/L)
15 ab
7.8-31
22'
7.2-45
6.5ab
2.1-17
4.9b
1.5-9.0
N/A
Nutrients (mg/L)
Ammonia-N
0.02
<0.01-0.05
0.02
<0.01-0.09
0.04
<0.01-0.13
0.03
<0.01-0.11
0.02
<0.01-0.07
Nitrate + Nitrite N
0.05
<0.02-0.15
0.07
<0.02-0.23
0.10
<0.02-0.22
0.06
<0.02-0.17
0.09
<0.02-0.27
Total nitrogen
0.55
0.21-1.30
0.56
0.19-0.77
0.48
0.20-0.82
0.44
<0.12-0.74
0.57
0.37-0.83
Total Kjeldahl Nitrogen
0.50
0.11-1.20
0.49
0.10-0.77
0.38
<0.10-0.61
0.40
<0.10-0.73
0.49
0.25-0.67
Total phosphorus
0.052ab
0.027-0.095
0.047ab
0.034-0.072
0.028ab
0.015-0.061
0.023b
0.009-0.060
0.057'
0.044-0.068
Total organic carbon (mg/L)
7.5
5.8-9.2
8.2
5.5-11.5
6.5
4.8-8.1
6.1
4.8-8.1
7.7
6.0-11.5
Ions (mg/L)
Calcium
12ab
8.0-20
7.3b
5.5-10
16'
9.5-23
16a
9.6-23
7.3b
6.3-8.6
Chloride
18ab
9-32
6.9b
4.0-12.8
27a
12-44
27a
11-44
5.8b
4.1-9.5
Magnesium
5.4ab
3.5-7.8
3.3b
2.5-4.4
7.0 a
4.2-9.7
6.8a
4.0-9.7
3.3b
2.9-3.8
Sodium
< 5
N/A
< 5
N/A
< 5
N/A
< 5
N/A
< 5
N/A
Sulfate
14a
8-21
5.7b
4.0-9.3
19a
10-27
19a
9-27
5.2b
3.7-8.8
Total alkalinity (mg/L as
27ab
23-30
30ab
25-35
27ab
25-28
27b
25-28
32a
28-37
CaCO3)
Hardness (mg equiv. CaCO3/L)
53ab
34-81
32b
24-44
68a
41-98
67a
40-98
32b
28-37
Specific conductance(µS/cm)
139ab
87-210
133ab
72-238
188,
116-260
185,
108-256
94b
82-111
Trace elements (µg/L)
Arsenic
0.9ab
0.6-1.3
0.5b
< 0.5-0.9
1.11
0.8-1.5
l.la
0.8-1.4
0.5b
< 0.5-1.0
Boron
367ab
181-674
72b
< 50-142
592'
277-1070
584a
239-1020
36b
< 50-94
Copper
1.9
1.2-2.8
1.5
0.9-1.8
1.6
1.1-2.2
1.5
1.0-2.2
1.5
0.8-2.2
Manganese
56b
24-81
73ab
47-108
97ab
62-149
64ab
34-123
119a
87-186
Mercury,(ng/L)
2.14
<0.50-4.54
2.71
0.91-4.73
1.78
0.99-4.16
1.75
0.91-4.31
2.68
1.19-5.45
Selenium
< 0.5
N/A
< 0.5
N/A
0.8
0.6-1.2
0.8
0.6-1.4
< 0.5
N/A
Thallium
< 0.1
N/A
< 0.1
N/A
< 0.1
N/A
< 0.1
N/A
< 0.1
N/A
'Unless otherwise noted, all measurements were taken from the surface. Fisher's protected Least Significant Difference (LSD) test was
applied only if the overall F test for the treatment was significant. Means followed by different superscripts were significantly
different from each other (P = 0.05). The rows where significant differences occurred are shaded. Data were rounded to conform
to significant digit requirements. Rounding may obscure mean differences. The variable pH was reported as a median value and
was not subjected to statistical analysis. Sample size equaled 6 unless otherwise noted. Statistical testing was conducted on surface
water means only. N/A means not applicable and NS means not sampled.
'Less than values (<) indicate the Lower Reporting Limit (LRL) for the variable. The LRL is a statistically determined limit beyond which
chemical concentrations cannot be reliably quantified. Statistical analyses were utilized only when mean concentrations were
above the highest analytical LRL and where LRL values occurred, means were calculated by utilizing one half of the absolute
value of each LRL.
§Mercury was measured in nanograms per liter (ng/L).
Duke Energy Progress 27 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 5. Concentrations of chemical variables in surface waters of Hyco Reservoir during
2017.'1
Station B2
Month
TDS
Turbidity
Secchi
Chlorophyll a
NH3-N
NO3 + NOi -N
TN
TP
TN:TP
TOC
depth
Feb
111
33
0.5
14
0.03
0.11
0.75
0.110
6.8
9.0
Apr
85
64
6.3
< 0.01
0.06
0.23
0.094
2.4
11
Jun
73
5.3
1.2
16
< 0.01
< 0.02
0.35
0.016
22
6.0
Aug
108
6.1
1.0
0.0
< 0.01
< 0.02
0.29
0.016
18
5.9
Oct
131
2.4
1.9
7.8
< 0.01
0.02
< 0.12
< 0.005
5.8
Dec
145
2.6
1.8
7.5
0.01
0.04
0.16
0.017
9.4
4.9
Month
Cat+
Cl-
Mg2+
Na
S042"
Alkalinity
Hardness As
B
Cu
Feb
9.7
13
4.6
< 5.0
10
25
43
0.6
173
3.0
Apr
6.4
5.8
3.1
< 5.0
6.0
17
29
0.9
94
4.2
Jun
9.4
11
4.5
< 5.0
11
23
42
0.9
244
1.9
Aug
16
22
6.9
< 5.0
18
26
67
1.4
504
1.3
Oct
19
30
7.9
< 5.0
19
28
79
1.5
611
1.1
Dec
19
29
8.5
5.9
20
31
81
1.4
772
1.2
Month
Hg§
Se
Mn
Tl
TKN
Feb
4.4
< 0.5
96
< 0.10
Apr
4.3
< 0.5
78
< 0.10
0.2
Jun
0.6
< 0.5
42
< 0.10
0.4
Aug
0.4
0.8
56
< 0.10
0.3
Oct
0.03
1.1
31
< 0.10
< 0.1
Dec
< 0.50
0.7
65
< 0.10
0.1
Station C2
Month
TDS
Turbidity
Secchi
Chlorophyll a
NH3-N NO3 + NO2 -N
TN
TP TN:TP
TOC
depth
Feb
74
40
0.5
4.8
0.03
0.26
0.85
0.071 12
8.0
Apr
74
32
0.5
13
< 0.01
0.12
0.35
0.067 5.2
8.5
Jun
47
12
0.5
37
< 0.01
< 0.02
0.65
0.036 18
6.2
Aug
80
10
0.7
16
0.03
< 0.02
0.45
0.023 20
6.2
Oct
94
4.6
1.1
20
< 0.01
< 0.02
0.30
0.022 14
7.1
Dec
123
6.1
1.1
15
< 0.01
0.04
0.28
0.026 11
4.9
Month
Ca'
Cl-
Mg2+
Na
S042-
Alkalinity Hardness
As B
Cu
Feb
64
4.7
3.0
< 5.0
5.8
21
28
0.4 < 50
2.5
Apr
58
3.3
2.7
< 5.0
4.7
20
26
0.5 < 50
2.2
Jun
61
3.2
2.8
< 5.0
3.8
21
27
0.7 < 50
2.7
Aug
103
10
4.7
< 5.0
8.7
30
45
1.1 187
1.0
Oct
128
17
5.4
< 5.0
10
34
54
0.9 309
0.6
Dec
159
23
6.9
5.8
16
31
68
1.0 580
1.0
Month
Hg§
Se
Mn
Tl
TKN
Feb
3.290
< 0.5
92
< 0.10
Apr
2.305
< 0.5
97
< 0.10
0.2
Jun
0.800
< 0.5
43
< 0.10
0.7
Aug
0.335
< 0.5
143
< 0.10
0.5
Oct
0.013
< 0.5
64
< 0.10
0.3
Dec
0.083
0.5
91
< 0.10
0.2
Duke Energy Progress
28
Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 5. (cont.)
Station D2
Month
TDS
Turbidity
Secchi
Chlorophyll a
NH3-N
NO3-+ NOi -N
TN
TP
TN:TP
TOC
depth
Feb
103
4.8
< 0.01
0.12
0.56
0.019
29
5.4
Apr
123
21
0.6
1.5
0.03
0.08
0.22
0.036
6.1
6.9
Jun
86
7.4
0.9
5.1
< 0.01
< 0.02
0.41
0.018
23
6.0
Aug
135
3.1
1.7
3.6
0.03
0.03
0.36
0.006
63
6.3
Oct
139
2.3
2.3
4.5
0.02
0.19
0.21
0.008
28
5.4
Dec
153
3.8
1.7
3.9
0.05
0.08
0.26
0.170
1.5
4.6
Month
Ca 21
C17
Mgt+
Na
S042-
Alkalinity
Hardness
As
B
Cu
Feb
17
26
81
< 5.0
18
26
76
1.4
510
2.3
Apr
14
19
62
< 5.0
16
25
59
1.0
396
2.6
Jun
10
14
50
< 5.0
14
23
46
1.1
309
1.8
Aug
19
28
82
< 5.0
22
26
81
1.8
636
1.2
Oct
19
32
79
< 5.0
20
29
80
1.6
685
1.0
Dec
20
32
87
5.9
22
30
86
1.7
838
1.6
Month
Hg
Se
Mn
Tl
TKN
Feb
1.4100
0.8
86
< 0.10
Apr
2.8400
0.7
84
< 0.10
0.1
Jun
0.5700
0.6
173
< 0.10
0.4
Aug
0.5450
1.0
205
< 0.10
0.3
Oct
0.1415
0.7
82
< 0.10
< 0.1
Dec
0.3250
0.8
276
< 0.10
0.2
Station F2
Month
TDS
Turbidity
Secchi
Chlorophyll a
NH3-N
NO3 + NOi -N
TN
TP
TN:TP
TOC
depth
Feb
134
6.3
1.6
7.5
< 0.01
0.13
0.53
0.018
29
5.5
Apr
108
15
0.8
6.6
< 0.01
0.05
0.25
0.035
7.1
7.4
Jun
88
3.0
1.5
5.4
< 0.01
< 0.02
0.24
< 0.005
5.7
Aug
126
3.1
1.5
3.6
0.02
0.03
0.28
< 0.005
6.3
Oct
137
2.0
2.3
4.8
< 0.01
< 0.02
0.12
< 0.005
5.5
Dec
141
2.9
2.0
3.6
< 0.01
0.08
0.24
0.035
6.9
4.6
Month
CaZ+
Cl-
Mg2+
Na
S042-
Alkalinity
Hardness
As
B
Cu
Feb
17
26
8.0
< 5.0
18
26
76
1.4
533
2.1
Apr
13
17
5.8
< 5.0
15
25
56
0.9
366
2.0
Jun
11
15
5.2
< 5.0
15
18
49
0.9
317
1.7
Aug
16
24
6.9
< 5.0
19
25
68
1.7
540
1.1
Oct
18
31
7.6
5.2
20
30
76
1.7
673
0.9
Dec
19
30
8.5
5.7
21
30
83
1.7
780
1.5
Month
Hg§
Se
Mn
Tl
TKN
Feb
0.9800
< 0.5
70
< 0.10
Apr
0.7650
< 0.5
63
< 0.10
0.2
Jun
1.0765
0.6
61
< 0.10
0.2
Aug
0.2065
1.0
210
< 0.10
0.3
Oct
0.0445
1.1
49
< 0.10
0.1
Dec
0.1675
0.8
152
< 0.10
0.2
Duke Energy Progress 29 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 5. (cont.)
Station SHHW1
Month
TDS
Turbidity
Secchi
Chlorophyll a
NH3-N
NOi + NOi -N
TN
TP
TN:TP
TOC
depth
Feb
59
22
< 0.01
0.23
0.78
0.050
16
5.8
Apr
59
24
< 0.01
0.11
0.33
0.063
5.2
8.3
Jun
59
10
0.7
< 0.01
< 0.02
0.28
0.033
8.5
7.8
Aug
68
20
< 0.01
< 0.02
0.51
0.021
24
7.4
Oct
81
11
0.7
< 0.01
< 0.02
0.49
0.041
12
7.7
Dec
118
5.9
< 0.01
< 0.02
0.32
0.031
10
5.1
Month
Cat+
Cl-
Mg2+
Na
S042-
Alkalinity
Hardness
As
B
Cu
Feb
7.1
4.5
3.4
< 5.0
6.2
26
32
0.3 < 50
1.8
Apr
6.5
3.4
3.1
< 5.0
5.3
24
29
0.4 < 50
2.3
Jun
6.3
2.9
2.8
< 5.0
4.2
24
27
0.5 < 50
1.5
Aug
8.8
7.4
4.0
< 5.0
6.9
30
38
0.9 114
1.1
Oct
10.7
11
4.5
5.4
6.6
38
45
0.7 151
0.8
Dec
14.6
20
6.4
5.2
13
34
63
0.8 422
<
1.0
Month
Hg§
Se
Mn
Tl
Feb
2.1
< 0.5
126
< 0.10
Apr
1.1
< 0.5
128
< 0.10
Jun
0.8
<0.5
101
<0.10
Aug
0.6
< 0.5
200
< 0.10
Oct
0.1
< 0.5
149
< 0.10
Dec
0.1
< 0.10
+Units are in mg/L except for most trace elements (µg/L) turbidity (NTU), total alkalinity (mg/L as
CaCO3), and hardness (calculated as mg equivalents CaCO3/L). Less than values (<) indicate the
Lower Reporting Limit (LRL) for the variable. The LRL is a statistically determined limit beyond
which chemical concentrations cannot be reliably reported. NS means not sampled.
91All variables are surface measurements.
§Mercury was measured in nanograms per liter (ng/L).
Duke Energy Progress 30 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 6. Concentrations of chemical variables in surface waters of Hyco Reservoir during
2018."
Station B2
Month
TDS
Turbidity
Secchi
Chlorophyll
a NH3-N
NOs'+ NOi -N
TN
TP
TN:TP
TOC
depth
Feb
155
12
0.9
8.1
0.02
0.10
0.21
0.033
6.4
5.8
Apr
117
35
0.4
31
< 0.01
< 0.02
1.30
0.095
14
9.2
Jun
108
4.3
1.3
14
0.03
< 0.02
0.37
6.6
Aug
118
4.1
1.3
7.8
< 0.01
< 0.02
0.37
0.027
14
6.3
Oct
123
2.8
1.7
17
< 0.01
< 0.02
0.32
0.027
12
8.4
Dec
98
30
0.5
9.0
0.05
0.15
0.75
0.078
9.6
8.6
Month
Caz+
Cl-
Mg2+
Na
S042'
Alkalinity
Hardness
As
B
Cu
Feb
20
32
7.8
5.8
21
29
81
1.0
674
1.6
Apr
8.3
13
4.2
5.5
9.8
26
38
0.6
186
2.8
Jun
12
14
5.0
< 5.0
12
28
50
0.7
268
2.1
Aug
12
19
5.6
5.7
15
30
54
1.3
433
1.2
Oct
13
22
6.3
< 5.0
16
28
59
1.2
457
1.2
Dec
8.0
9.0
3.5
< 5.0
7.8
23
34
0.8
181
2.7
Month
Hg§
Se
Mn
Tl
TKN
Feb
1.7
0.8
63
< 0.10
0.1
Apr
4.5
< 0.5
56
< 0.10
1.2
Jun
1.6
< 0.5
40
< 0.10
0.4
Aug
0.3
0.5
81
< 0.10
0.4
Oct
1.3
0.5
24
< 0.10
0.3
Dec
4.4
< 0.5
71
< 0.10
0.6
Station C2
Month
TDS
Turbidity
Secchi
Chlorophyll
a NH3-N
NOs + NOi -N
TN
TP
TN:TP
TOC
depth
Feb
88
16
0.9
7.2
0.01
0.09
0.19
0.034
5.6
5.5
Apr
76
21
0.6
22
< 0.01
0.08
0.60
0.056
11
7.9
Jun
73
6.3
1.0
24
0.03
< 0.02
0.68
8.4
Aug
83
5.4
0.9
26
< 0.01
< 0.02
0.32
0.034
9.4
8.4
Oct
81
6.2
45
0.01
< 0.02
0.77
0.040
19
12
Dec
85
25
0.5
7.2
0.09
0.23
0.77
0.072
11
7.7
Month
Cat+
Cl-
Mgz+
Na
SO42-
Alkalinity
Hardness
As
B
Cu
Feb
10
13
4.4
6.7
9.3
33
44
< 0.5
137
1.4
Apr
6.0
5.6
2.9
5.2
5.5
27
27
0.4
< 50
1.7
Jun
7.2
4.1
3.0
< 5.0
4.0
31
30
0.6
< 50
1.8
Aug
8.7
8.5
3.9
5.7
6.1
35
38
0.9
142
0.9
Oct
6.2
6.2
3.3
< 5.0
5.3
29
29
0.7
80
1.3
Dec
5.5
4.0
2.5
< 5.0
4.2
25
24
0.4
< 50
1.7
Month
Hg§
Se
Mn
Tl
TKN
Feb
2.7
< 0.5
93
< 0.10
0.1
Apr
2.6
<0.5
59
<0.10
0.5
Jun
2.3
< 0.5
47
< 0.10
0.7
Aug
0.9
< 0.5
108
< 0.10
0.3
Oct
2.9
<0.5
51
<0.10
0.8
Dec
4.7
< 0.5
78
< 0.10
0.5
Duke Energy Progress
31
Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 6. (cont.)
Station D2
Month
TDS
Turbidity
Secchi
Chlorophyll a
NH3-N
NO3 + NO2 -N
depth
Feb
175
3.9
1.6
2.1
0.02
0.10
Apr
154
5.3
1.3
6.9
< 0.01
0.05
Jun
114
5.0
1.1
17
0.04
< 0.02
Aug
137
2.2
1.9
3.6
< 0.01
< 0.02
Oct
138
4.2
6.0
0.02
0.22
Dec
101
23
0.7
3.3
0.13
0.18
Month
Ca2+
Cl-
Mg2+
Na
S042-
Alkalinity
Feb
23
44
9.7
5.9
27
28
Apr
19
41
8.6
5.9
25
28
Jun
14
17
5.7
< 5.0
15
28
Aug
14
24
6.8
5.7
18
27
Oct
14
24
6.9
< 5.0
17
26
Dec
10
12
4.2
< 5.0
9.9
25
Month
Hg§
Se
Mn
Tl
TKN
Feb
1.4
1.2
149
< 0.10
< 0.1
Apr
1.0
0.9
62
< 0.10
0.2
Jun
1.8
0.6
90
< 0.10
0.4
Aug
1.1
0.6
76
< 0.10
0.3
Oct
1.2
0.6
106
< 0.10
0.6
Dec
4.2
0.6
98
< 0.10
0.6
Station F2
Month
TDS
Turbidity
Secchi
Chlorophyll a
NH3-N
NO3 + NO2 -N
depth
Feb
183
2.6
2.3
1.8
0.01
0.10
Apr
148
4.1
6.6
< 0.01
0.04
Jun
119
2.8
1.3
9.0
0.03
< 0.02
Aug
124
1.6
2.6
5.1
< 0.01
< 0.02
Oct
138
2.2
5.7
< 0.01
< 0.02
Dec
108
23
0.7
1.5
0.11
0.17
Month
Cat+
Cl-
Mg2+
Na
S042-
Alkalinity
Feb
23
42
9.7
5.7
27
27
Apr
20
44
8.4
5.9
25
28
Jun
14
18
5.7
5.0
16
28
Aug
13
22
6.4
5.8
17
26
Oct
14
25
6.8
< 5.0
18
26
Dec
9.6
11
4.0
< 5.0
8.9
25
Month
Hg§
Se
Mn
Tl
TKN
Feb
1.0
1.4
123
< 0.10
< 0.1
Apr
0.9
0.9
54
< 0.10
0.3
Jun
1.4
0.6
34
< 0.10
0.4
Aug
0.9
0.6
45
< 0.10
0.4
Oct
2.0
0.6
39
< 0.10
0.7
Dec
4.3
0.6
91
< 0.10
0.6
TN
TP
TN:TP
TOC
0.20
0.015
13
4.8
0.29
0.020
15
5.2
0.42
6.8
0.35
0.024
15
6.2
0.82
0.021
39
8.0
0.78
0.061
13
8.1
Hardness
As
B
Cu
98
1.3
1070
1.3
83
1.0
803
1.4
57
0.8
327
2.1
64
1.4
595
1.1
64
1.5
480
1.3
41
0.9
277
2.2
TN
TP
TN:TP
TOC
< 0.12
0.009
4.8
0.32
0.011
29
4.8
0.39
6.2
0.38
0.015
25
6.0
0.73
0.018
41
6.8
0.74
0.060
12
8.1
Hardness
As
B
Cu
98
1.3
1020
1.2
83
1.1
820
1.3
58
0.8
351
1.8
60
1.4
535
1.2
63
1.4
536
1.0
40
0.9
239
2.2
Duke Energy Progress 32 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 6. (cont.)
Station SHHW1
Month
TDS
Turbidity
Secchi
Chlorophyll a
NH3-N
NO3 + NO2 -N
depth
Feb
105
36
0.5
0.03
0.20
Apr
72
18
0.6
< 0.01
0.02
Jun
77
9.6
0.7
0.02
< 0.02
Aug
84
11
0.6
< 0.01
< 0.02
Oct
81
11
< 0.01
< 0.02
Dec
83
22
0.6
0.07
0.27
Month
Cat+
Cl-
Mgz+
Na
S042-
Alkalinity
Feb
8.1
9.5
3.7
6.6
8.8
28
Apr
6.3
5.2
3.0
5.4
5.4
28
Jun
7.4
4.1
3.2
< 5.0
3.9
33
Aug
8.6
7.2
3.8
5.5
4.7
37
Oct
7.0
4.7
3.3
< 5.0
3.7
33
Dec
6.4
4.1
2.9
< 5.0
4.7
30
Month
Hg§
Se
Mn
Tl
TKN
Feb
5.4
115
< 0.10
0.3
Apr
2.1
<0.5
87
<0.10
0.4
Jun
2.3
< 0.5
95
< 0.10
0.5
Aug
1.2
<0.5
186
<0.10
0.6
Oct
1.8
< 0.5
126
< 0.10
0.7
Dec
3.3
< 0.5
106
< 0.10
0.6
TN
TP
TN:TP
TOC
0.45
0.061
7.4
6.1
0.37
0.044
8.4
7.1
0.54
7.5
0.58
0.060
9.7
7.7
0.67
0.068
9.9
12
0.83
0.053
16
6.0
Hardness
As
B
Cu
35
<0.5
<50
2.2
28
0.4
<50
1.5
31
0.6
<50
1.5
37
1.0
94
0.8
31
0.6
<50
1.2
28
0.3
<50
1.5
+Units are in mg/L except for most trace elements (µg/L) turbidity (NTU), total alkalinity (mg/L as
CaCO3), and hardness (calculated as mg equivalents CaCO3/L). Less than values (<) indicate the
Lower Reporting Limit (LRL) for the variable. The LRL is a statistically determined limit beyond
which chemical concentrations cannot be reliably reported. NS means not sampled.
91All variables are surface measurements.
§Mercury was measured in nanograms per liter (ng/L).
Duke Energy Progress 33 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Chloride
200
J 175
O7
150
c
O 125
100
N
c 75
O
U 50
255 #---------------------------- 4--------- ----- _-----
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Hardness
250
J 200
150
c
0
100
O
U
a 50
U
0
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Copper
15
0
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Dissolved Solids
500
J
6�400
E
O u. i 6 - -
U100---------------------------------------------------------
0
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Arsenic
5
J 4
O1
1
c 3
O
c2----------------------------------------- ----------------------------------------------
O
U
O
U1 --- ---- -- ---- --- --- --- --- --- ----
0
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Selenium
5
6 4
m
ZL
c
O 3
CU
2
U
c
O
U 1
0 1.
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Appendix 7. Long-term trends of selected parameters at Station B2 from Hyco Reservoir from
2009 through 2018.
Duke Energy Progress 34 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Chloride
100
J
0)
E 75
0
50
c
O
U
0
O
() 25
0
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Hardness
225
J200___________________________________________________________________________________
175---------------------------------------------------
EO 150------------------------------ -------------------------------------------------
O
125--------------------- ------ - ------ -----------------------------------------
100-------------- ---- - ---- ---- ----- - ----------------------------------------
U
O
U50 --- -- ---- ----- -------------- -- -- -- --- --- - --- --- ------ - -----
25 ------------------------ -------------------------- -----
0
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Copper
25
20
p 15
1) 10
U
C
0
U 5
0 -
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Dissolved Solids
600
J 500
E
r_ 400
0
T 300
c
O
c 200
0
U
100
0
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Arsenic
5
J4
o3
m
0 2
U
c
O
M
0 n
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Selenium
c
� 3
c
O 2
0
0
U
1
0
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Appendix 8. Long-term trends of selected parameters at Station C2 from Hyco Reservoir from
2009 through 2018.
Duke Energy Progress 35 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Chloride
150
125
E
C 100
0
75
C
N
C 50
O
U
25 i i------------- I-----------
o
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Hardness
N1.111
a)200
E
0 150
2
0 100
U
C
0
U 50
0 i.
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
15
J
0)
1
C10
O
C
41
C 5
O
i
Total Copper
0 !
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Dissolved Solids
J 500
400
0
.-�6 300
C
0
0 200
C
0
U
100
0
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Arsenic
5
J
a74
C
'0 3
C
U 2
C
O
U
1
0 i.
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Selenium
5
0 1.
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Appendix 9. Long-term trends of selected parameters at Station D2 from Hyco Reservoir from
2009 through 2018.
Duke Energy Progress 36 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Chloride
150
125
E
100
0
75
c
N
c 50
0
U
25
0
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Hardness
250
J
E200
C
O 8 150
C
0
U 100
C
0
U
50
0 i.
2009 2010 2011 2012 2012 2014 2015 2016 2017 2018
Year
Total Copper
20
J
m
s
15
U 5
0
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Dissolved Solids
400
J
01 300
E
0
200
0 100
U
0
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Arsenic
5
0 i.
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Total Selenium
5
0 1t
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
Appendix 10. Long-term trends of selected parameters at Station F2 from Hyco Reservoir from
2009 through 2018.
Duke Energy Progress 37 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 11. Means and standard errors of trace element concentrations (µg/g dry weight) in
sediments and fish by transect from Hyco Reservoir during 2017. (Values in
parentheses are the corresponding wet weight values.)ql
Matrix
n
Transect
Element
Arsenic
Cadmium
Copper
Mercury
Selenium
Sediments
3
C
<6.2
< 2.9 (1.1)
75 (28) f 0.5 (0.2)
< 3.6 (1.3)
2.2 (0.8) f 0.2 (0.07)
3
D
6.2 (3.9) t 1.6 (1.0)
< 2.9 (1.8)
85 (53) t 2.6 (1.6)
< 3.6 (2.2)
2.7 (1.7) t 0.1 (0.09)
Fish muscle
White Catfish
10
C
< 0.2 (0.04)
< 2.0 (0.4)
0.6 (0.1) t 0.3 (0.05)
0.6 (0.1)t 0.06 (0.011)
3.16 (0.6) t 0.9 (0.08)
10
D
< 0.2 (0.04)
< 2.0 (0.4)
0.9 (0.2) f 0.3 (0.05)
0.5 (0.1) f 0.06 (0.01)
6.3a (1.1) t 0.4 (0.3)
Bluegill
10
C
< 0.2 (0.04)
< 2.0 (0.3)
2.6- (0.5) t 0.7 (0.1)
0.9- (0.2)t 0.06 (0.011)
4.16 (0.7) t 0.6 (0.1)
10
D
0.6 (0.1) t 0.1 (0.03)
< 2.0 (0.4)
0.4e (0.07) t 0.08 (0.02)
0.4e (0.07) t 0.04 (0.008)
9.9a (0.5) t 1.9 (0.1)
Largemouth Bass
10
C
0.56 (0.1) t 0.08 (0.02)
< 2.0 (0.4)
0.3 (0.2) t 0.09 (0.02)
1.1 (0.2) t 0.08 (0.02)
4.26 (0.9) t 0.2 (0.04)
10
D
0.8a (0.2) t 0.06 (0.01)
1 < 2.0 (0.4)
10.3 (0.07) t 0.06 (0.013)
1.1 (0.2) t 0.1 (0.02)
8.6a (1.7) + 0.5 (0.1)
+ To convert to mean dry weight concentrations, divide the mean wet weight concentration by the
appropriate mean dry -to -fresh weight ratio as follows: sediments-Transect C0.36, Transect
D-0.62, White Catfish muscle-0.18, Bluegill muscle-0.19, and Largemouth Bass muscle-
0.20.
"Standard errors and statistical analyses are given when mean concentrations were at or above the
laboratory reporting limit. Laboratory reporting limits varied between samples. Means separation
procedures were applied only if the overall test for transect was significant. Means for each
element followed by different superscripts were significantly different at the P = 0.05 level and
were shaded gray to denote significant results between transects.
Duke Energy Progress 38 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 12. Means and standard errors of trace element concentrations (µg/g dry weight) in
sediments and fish by transect from Hyco Reservoir during 2018. (Values in
parentheses are the corresponding wet weight values.)ql
Matrix
n
Transect
Element
Arsenic
Cadmium
Copper
Mercury
Selenium
Sediments
3
C
5.0" (1.9) f 0.03 (0.01)
0.09e (0.03) f 0.002 (0.001)
56 (21) f 0.8 (0.3)
0.08e (0.03) f 0.002 (0.001)
4.4e (2.0) f 0.2 (0.08)
3
D
16- (5.8) t 0.7 (0.25)
0.14a (0.05) t 0.01 (0.004)
88 (32) t 2.5 (0.91)
0.16a (0.06) t 0.007 (0.002)
7.6- (3.0) t 0.4 (0.2)
Fish muscle
White Catfish
4
C
< 0.5 (< 0.1)
< 0.5 (< 0.1)
< 4.7 (< 0.9)
0.7 (0.1) f 0.2 (0.01)
1.8 (0.3) t 0.1 (0.02)
6
D
< 0.5 (< 0.1)
< 0.5 (< 0.1)
3.9 (0.7) t 1.7 (0.3)
0.4 (0.1) t 0.07 (0.01)
3.4 (0.6) t 1.2 (0.2)
Blueglll
8
C
< 0.5 (< 0.1)
< 0.5 (< 0.1)
< 4.7 (0.9)
0.4- (0.07) t 0.03 (0.01)
1.9e (0.4) t 0.2 (0.04)
10
D
0.7 (0.1)f 0.09 (0.02)
< 0.5 (< 0.1)
10 (1.9) t 3.8 (0.7)
0.3e (0.05) t 0.02 (0.004)
7.2' (1.4) t 0.4 (0.09)
Largemouth
9mr-
Bass
10
C
0.5" (0.1) t 0.05 (0.01)
< 0.5 (< 0.1)
13 (2.5) t 4.1 (0.8)
1.1 (0.2) t 0.07 (0.01)
3.1 (0.6) t 0.08 (0.02)
10
D
0.8a (0.2) t 0.08 (0.02)
< 0.5 (< 0.1)
13 (2.5) t 2.0 (0.4)
1.1 (0.2) t 0.1 (0.02)
1 5.5 (1.0) t 0.4 (0.08)
+ To convert to mean dry weight concentrations, divide the mean wet weight concentration by the
appropriate mean dry -to -fresh weight ratio as follows: sediments0.36, White Catfish muscle
0.19, Bluegill muscle-0.19, and Largemouth Bass muscle-0.19.
9'Standard errors and statistical analyses are given when mean concentrations were at or above the
laboratory reporting limit. Laboratory reporting limits varied between samples. Means separation
procedures were applied only if the overall test for transect was significant. Means for each
element followed by different superscripts were significantly different at the P = 0.05 level and
were shaded gray to denote significant results between transects.
Duke Energy Progress 39 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
25
an
tw 20
3
15
0
U
E 10
3
°J 5
v
0 d
25
oa
to
3
�15
0
U
E10
0
.E
°J 5
v
0
at
to
M
_=�15
U
C
U10
G=.
Bluegill
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
—*--Transect C —IF—Transect D
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
—4--Transect C --*--Transect D
White Catfish
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Year
—4—Transect C —IF—Transect D
Appendix 13. Long-term trends of selenium concentrations (dw) in Bluegill, Largemouth Bass,
and White Catfish muscle tissues at Transect C and Transect D from Hyco
Reservoir from 2009 through 2018.
Duke Energy Progress 40 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 14. Total number and weight (kilograms) of fish collected with electrofishing from
Hyco Reservoir during 2017 and 2018.
2017
2018
Scientific name'
Common name
Total Number
Total weight
k
Total number
Total weight
k
lupeidae
Herrings
Dorosoma cepedianum
Gizzard Shad
228
51.1
168
30.1
Dorosoma petenense
Threadin Shad
152
0.6
75
0.2
yprinidae
Minnows
Notemigonus crysoleucas
Golden Shiner
2
0.1
2
< 0.1
Cyprinella analostana
Satinfin Shiner
40
0.1
30
0.1
Notropis hudsonius
Spottail Shiner
0
0.0
6
< 0.1
Cyprinus carpio
Common Carp
2
10.5
1
7.0
atostomfdae
Suckers
Erimyzon oblongus
Creek Chubsucker
1
0.3
3
1.0
Moxostoma collapsum
Notchlip Redhorse
29
31.2
13
12.8
Moxostoma erythrurum
Golden Redhorse
7
3.3
2
1.6
Moxostoma pappillosum
V-lip Redhorse
2
1.1
0
0.0
Moxostoma commersonii
White Sucker
1
0.4
0
0.0
ctaluridae
Bullhead catfishes
Ameiurus catus
White Catfish
12
4.7
34
0.7
Ameiurus platycephalus
Flat Bullhead
10
0.9
5
0.7
ktalurus punctatus
Channel Catfish
39
35.0
25
27.1
Ameiurus natalis
Snail Bullhead
1
< 0.1
1
0.3
entrarchidae
Sunfishes
Lepomis cyanellus
Green Sunfish
38
0.9
20
0.4
Lepomis gulosus
Warmouth
5
0.2
4
0.2
Lepomis macrochirus
Bluegill
1385
29.4
2,233
29.2
Lepomis microlophus
Redear Sunfish
191
25.9
160
24.6
Lepomis hybrid
Hybrid Sunfish
11
0.7
1
0.4
Micropterus salmoides
Largemouth Bass
349
106.1
330
120.8
Pomoxis nigromaculatus
Black Crappie
60
13.1
45
4.7
ercidae
Perches
Perca flavescens
Yellow Perch
31
0.9
34
0.8
Morone chrysops
White Bass
2
0.8
0
0.0
Etheostoma nigrum
Johnny Darter
1
0.1
0
0.0
ichlidae
Cichlids
Tilapia aurea
Blue Tilapia
5
1.5
4
0.5
otall
2,606
319.0
3,173
263.4
Total Species
24
21
'Taxonomic nomenclature follows Page et al. (2013).
9ITotals include only fish identified to species level.
Duke Energy Progress 41 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 15. Mean catch per hour (CPUE) of fish collected with electrofishing by transect from
Hyco Reservoir during 2017.
Common Name
Transect
Reservoir mean
A
B
C
D
F
Gizzard Shad
19
42
12
22
20
22
Threadfin Shad
2
< 1
74
0
0
15
Satinfin Shiner
7
2
10
0
0
4
Golden Shiner
0
0
1
0
0
< 1
Common Carp
0
< 1
0
< 1
0
< 1
Creek Chubsucker
0
0
< 1
0
0
< 1
Notchlip Redhorse
0
2
12
0
0
3
Golden Redhorse
< 1
3
< 1
0
0
< 1
V-lip Redhorse
0
< 1
< 1
0
0
< 1
White Sucker
0
0
< 1
0
0
< 1
White Catfish
1
3
1
< 1
0
1
Flat Bullhead
< 1
0
3
0
2
< 1
Snail Bullhead
0
0
0
0
< 1
< 1
Channel Catfish
1
4
8
2
3
4
Yellow Bullhead
< 1
0
0
0
0
< 1
Green Sunfish
1
0
3
6
9
4
Warmouth
< 1
0
0
1
< 1
< 1
Bluegill
203
42
155
199
77
135
Redbreast Sunfish
0
< 1
0
0
0
< 1
Redear Sunfish
21
38
16
10
9
19
Hybrid Sunfish
0
0
0
4
2
1
Largemouth Bass
36
26
40
34
35
34
Black Crappie
9
12
8
0
< 1
6
Yellow Perch
< 1
< 1
14
0
0
3
White Bass
0
0
1
0
0
< 1
Blue Tilapia
0
< 1
0
2
0
< 1
Johnny Darter
0
< 1
0
0
0
< 1
Total CPUE'
302
175
360
281
159
254
Total number of speciesT
15
17
19
10
10
26
'Total catch per unit effort (CPUE) may vary from column sums due to rounding.
9ITotal number of species does not include hybrid sunfish.
Duke Energy Progress 42 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Appendix 16. Mean catch per hour (CPUE) of fish collected with electrofishing by transect from
Hyco Reservoir during 2018.
Common Name
Transect
Reservoir mean
A
B
C
D
F
Gizzard Shad
18
22
24
16
6
17
Threadfin Shad
1
3
14
6
14
8
Satinfin Shiner
6
2
6
0
0
3
Spottail Shiner
0
2
1
0
0
< 1
Golden Shiner
0
< 1
0
0
0
< 1
Common carp
0
0
< 1
0
0
< 1
Creek Chubsucker
1
< 1
0
0
0
< 1
Notchlip Redhorse
0
< 1
6
0
0
1
Golden Redhorse
1
0
0
0
0
< 1
White Catfish
< 1
1
0
< 1
< 1
< 1
Flat Bullhead
1
0
0
0
2
< 1
Snail Bullhead
0
0
< 1
0
2
< 1
Channel Catfish
< 1
5
2
3
2
2
Green Sunfish
0
0
2
1
7
2
Warmouth
0
0
< 1
< 1
1
< 1
Bluegill
221
367
182
258
126
227
Redbreast Sunfish
0
0
< 1
0
0
< 1
Redear Sunfish
24
34
4
15
6
16
Hybrid Sunfish
0
0
< 1
2
0
< 1
Largemouth Bass
34
16
44
42
30
34
Black Crappie
12
10
2
< 1
0
5
Yellow Perch
2
8
2
4
2
4
Blue Tilapia
0
0
0
2
0
< 1
Total CPUE'
322
472
293
350
196
323
Total number of species9t
13
14
16
12
12
22
+ Total catch per unit effort (CPUE) may vary from column sums due to rounding.
'Total number of species does not include hybrid sunfish.
Duke Energy Progress 43 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
15
Transect A (Year = 2017)
10 Bluegill, n=414
Mean = 87
5 - -MILE
0 INNINNINEENEREb. ..... I I I
O Ln O Ln O Ln O Ln o
N Ln n O
Length (mm)
15 Transect B (Year = 2017)
Bluegill, n=85
10 Mean = 132
5
0
o Ln o Ln O Ln O Ln O
N Ln r, O N Ln n O
rIj
15 Length (mm)
Transect C (Year = 2017)
10 Bluegill, n=311
Mean = 149
5
No
o Ln o Ln O Ln O Ln
N Ln r,
15 Length (mm)
Transect D (Year = 2017)
10 Bluegill, n=415
}, Mean = 91
C=
v 5
a 0
o Ln Ln Ln o Ln Ln Ln o
N Ln in r` O
rIj
15 Length (mm) Transect F (Year = 2017)
Bluegill, n=160
10 Mean = 102
5
0 ■ ��—�--■ --
o Ln o Ln o Ln O Ln o
N Ln O N Ln r, CD.-- ` i N
10 Length (mm) Transects Combined (Year = 2017)
. Bluegill n=1385
Mean = 100 mm
5
X
O Ln o Ln o Ln o Ln o
N Ln N Ln r` O
N
Length (mm)
Appendix 17. Length -frequency distributions of Bluegill by transect collected by electrofishing
from Hyco Reservoir during 2017.
Duke Energy Progress 44 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
15 Transect A (Year = 2018)
Bluegill, n=441
Mean = 80
10
5
o Ln o f Ln O Ln O Ln O
N Ln r, O N Ln r\ O
.--� •--� •--� .--i N
Transect B (Year = 2018)
15 Bluegill, n=654
Mean = 98
10
0
O Ln O Ln O Ln O Ln
N Ln
15 Transect C (Year = 2018)
Bluegill, n=364
10 Mean = 93
N 5 ■■ ■ ■■■����—■----
UO . . . . . . . . . . . . . IN
L O Ln O Ln O Ln O Ln
N Ln r,
n
15 Transect D (Year = 2018)
Bluegill, n=515
Mean = 94
10
5
0
O Ln O Ln O Ln O Ln O
N Ln r, O N Ln r\ O
.--� •--� •--� •--� N
15 Transect F (Year = 2018)
Bluegill, n=251
10 Mean = 81
5
0 MEN
-- —
O Ln O Ln o Ln o Ln o
N Ln r, O N Lff r\ O
15 Transects combined (Year = 2018)
Bluegill, n=2225
Mean = 88
10
5
0 —
o Ln O Ln O Ln O Ln o
N Ln r\ O N r, CD
.--� `� •--� •--� N
Appendix 18. Length -frequency distributions of Bluegill by transect collected by electrofishing
from Hyco Reservoir during 2018.
Duke Energy Progress 45 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
15 Transect A (Year = 2017)
Largemouth Bass, n=73
Mean = 265
10
5
0 ■■ .■■. ■ 11
111■■.■
0 0 0 0 O O O O O O
Ln O N Ln CD Ln OM M I
Length (mm) Transect B (Year = 2017)
15 Largemouth Bass, n=53
Mean = 283
10
5
0 ■■ ■■ ■ ■ ■ ■■■■ ■■ ■■■■■ ■■ ■ ■
O O O O O O O O O O O
Ln o Ln o irn O u) O
N M M 7 7 Lr)
Length (mm) T t C Y = 2017
15
10
5
� 0
U 0 o Ln Oo N oo
Ln Ln
N M M
N Length (mm)
"-15
10
5
0 1 �1� ■■
O O O O CD CD O CD CCD
D
Ln O .�-i ON N OM M 7
Length (mm)
15
10
5
0
MIMES
0
Ln
0 0
u,
O u�
105
0 0
0 Ln
N N
Length (mm)
0
0
M
ransec ( ear )
Largemouth Bass n=79
Mean = 255
0 0 0
o Ln o
� Ln
Transect D (Year = 2017)
Largemouth Bass n=71
Mean = 216
■ ■ ■■
O 0 0
Ln O Ln
CY Ln Ln
Transect F (Year = 2017)
Largemouth Bass, n=73
Mean = 241
0 0
Ln O
M 7
Transects Combined (Year= 2017)
Largemouth Bass n=349
Mean = 251
0 ! -- —
o CD CD0 o O O O O o 0 0
Ln O CD N OM M 7 V_ LnLn
Length (mm)
Appendix 19. Length -frequency distributions of Largemouth Bass by transect collected by
electrofishing from Hyco Reservoir during 2047.
Duke Energy Progress 46 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
10 Transect A (Year = 2018)
Largemouth Bass, n=69
Mean = 250
5
0 1 Lon 0
0 0 0 0 0 O O 0 0 O
15 Largemouth Bass, n=28
Mean = 296
10
5
0
0 0 0 0 0 0 0 0 0
In O .Ln-i ON Ln N OM M 7
4.1
415 Transect C Year= 2018
Largemouth Bass, n=89
U Mean = 261
�510
d
5
O o O o O o 0 o C.
In O Ln ON N OM M 7
15 Transect D (Year = 2018)
Largemouth Bass, n=85
Mean = 281
10
5
0
0 0 0 0 0 0 O O 0 0 0 0
In O „may 0 Ln C3 Ln Ln Ln
N N OM M 7 7 VOI Ln
15 Transect F (Year = 2018)
Largemouth, Bass n=59
Mean = 258
10
5
0 1� 11 ��
0 0 0 0 0 0 0 o O o
in o Ln o Ln O M C. in
N M rn 7 7
10 Largemouth Bass, n=330
Mean = 267
5
0
0 O o 0 0 0 0 0 0 0 0 0
In O ti ON N OM M 7 7 In M
Appendix 20. Length -frequency distributions of Largemouth Bass by transect collected by
electrofishing from Hyco Reservoir during 2018.
Duke Energy Progress 47 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
25
20 Transect A (Year = 2017)
Gizzard Shad n=39
15 Mean = 264
10
5
0
0 0 0 0 0 0 0
Ln o in CDLn o
Length (MM)
25
20 Transect B (Year = 2017)
Gizzard Shad, n=77
15 Mean = 283
10
5
0
C. 0 0 0 0 0 0
Ln CDLn CDLn o
25 Length (MM)
20 Transect C (Year = 2017)
Gizzard Shad n=25
15 Mean = 250
10
C: 5
N
U 0
k"
o 0C:) CD
o voi o CD LO o
n
I..L 25 Length (MM)
20 Transect D (Year = 2017)
Gizzard Shad, n=45
15 Mean = 278
10
5
0
0 0 0 0 0 0 0
in o CD in CD+--i .Q N N M
25 Length (MM)
20 Transect F (Year = 2017)
Gizzard Shad, n=42
15 Mean = 299
10
5
0
0 0 0 0 0 0 0 0
o �, CD Ln o Ln
M
20 Length (MM)
15 Transects Combined (Year = 2017)
Gizzard Shad; n=228
10 Mean=278 mm
5
0
0 0 0 0 0 0 0 0
o o Ln o Ln
N N M M
Length (mm)
Appendix 21. Length -frequency distributions of Gizzard Shad by transect collected by
electrofishing from Hyco Reservoir during 2047.
Duke Energy Progress 48 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
25 Transect A (year-2018)
20 Gizzard Shad, n=37
15 Mean = 260
10
5
0
0 0 0
Ln o
.ti
25 Transect B (Year = 2018)
20 Gizzard Shad, n=39
15 Mean = 266
10
5
0
0 0 0 C.
Ln o Ln
25 Transect C (year= 2018)
20 Gizzard, Shad n=48
Mean = 192
15
10
L 5 oil
a 0 0 0 Cl
in o
rl
40 Transect D (Year=2018)
Gizzard Shad, n=33
30 Mean =277
20
10
0
0 Ln 0
in o
.ti
40 Transect F (Year = 2018)
Gizzard Shad, n=11
30 Mean = 287
20
10
0
0 0 0
15
10
5
0
0
Ln o
Transects combined (Year = 2018)
Gizzard Shad, n=168
Mean = 247
0 0
Ln o
.ti
0
.ti
0 0 0 0
in o Ln o
N N M
MENE 1 0MM
0 0 0
o Ln o
N N M
0 0 0 0
n O Ln o
0
Ln
0 0 0
O Ln o
N N M
0
minim
0
0
0
o
N
Ln
N
o
M
0 0 0
o Ln o
N N M
Appendix 22. Length -frequency distributions of Gizzard Shad by transect collected by
electrofishing from Hyco Reservoir during 2018.
Duke Energy Progress 49 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Bluegill
L 140
120
t
100
80
�— 60
40
Meag value = 83 ± 9 (SD), n = 679
• M •
•
•
or
75 100 125 150 175 200 225
Length (mm)
Gizzard Shad
L 140
Mean value = 88 ± 10 (SD), n = 228
120
100
> 80
60
40
150 175 200 225 250 275 300 325 350 375
Length (mm)
_ 140 Largemouth bass
i
Mann vali is = Rd4 + R ignI n = 7RFi
�- 120
f
_al
100
j 80
d) 60
40
125 150 175 200 225 250 275 300 325 350 375 400 425 450
Length (mm)
Appendix 23. Relative weight values versus length for Bluegill, Gizzard Shad, and Largemouth
Bass collected by electrofishing from Hyco Reservoir during 2017.
Duke Energy Progress 50 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
140
120
T 100
80
c�
60
ID
40
bluegill
•: • • Mean value = 83 ± 11 (SD), n = 616
•• • 41
00
•• see•s .
oo so
75 100 125 150 175 200 225
Length (mm)
Gizzard Shad
140
Mean value = 92 ± 9 (SD), n = 147
120 •
100 •� • •• • •; •
�' • ': 'i:': •• •.
a� 80 • • • •' �. •.. •
•
•• • i • •
60
40 1 1 '
150 175 200 225 250 275 300 325 350 375
Length (mm)
Largemouth bass
L 140
Mean value = 89 ± 9 (SD), n = 273
120 •
' ' •AL j gel •�• « • •
a� 80� j'M• • • • •' '� • •
60
40 '
125 175 225 275 325 375 425 475 525 575
Length (mm)
Appendix 24. Relative weight values versus length for Bluegill, Gizzard Shad, and Largemouth
Bass collected by electrofishing from Hyco Reservoir during 2018.
Duke Energy Progress 51 Water Resources

Roxboro Steam Electric Plant 2017-2018 Environmental Monitoring Report
Will
60
a)
m
d 40
20 40
E
M
S
u
100
+100
:f
CZ
W
60
CZ
N_
0
40 d
20 40 60 80 100
PSD Largemouth Bass
♦--Bluegill versus Largemouth Bass for 2017
*--Gizzard Shad* versus Largemouth Bass for 2017
O--Bluegill versus Largemouth Bass for 2018
o--Gizzard Shad* versus Largemouth Bass for 2018
Appendix 25. Proportional Size Distribution (PSD) ranges for balanced populations of Bluegill
versus Largemouth Bass and Gizzard Shad versus Largemouth Bass collected from
Hyco Reservoir during 2017 and 2018 (No true "balance" range has been
determined for Gizzard Shad).
Duke Energy Progress 52 Water Resources