NC0003425_Report_20200608

ROXBORO STEAM ELECTRIC PLANT
2016 ENVIRONMENTAL MONITORING REPORT
July 2017
Water Resources
DUKE ENERGY
Raleigh, North Carolina

Roxboro Steam Electric Plant 2016 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
Duke Energy Progress i Water Resources

Roxboro Steam Electric Plant 2016 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
2016 Environmental Monitoring Report .....................................................................................
1
HistoricalOverview...............................................................................................................
1
ReservoirDescription............................................................................................................
2
Objectivesand Methods........................................................................................................
3
Results of Environmental Monitoring During 2016..............................................................
8
Limnology........................................................................................................................
8
Temperature and Dissolved Oxygen.........................................................................
8
Water Clarity Constituents........................................................................................
8
Nutrients and Phytoplankton Biomass.......................................................................
9
Ions, Hardness, and Specific Conductance................................................................
9
Alkalinityand pH......................................................................................................
9
TraceElements................................................................................................................
10
Arsenic.......................................................................................................................
10
Cadmium....................................................................................................................
10
Copper........................................................................................................................
10
Manganese.................................................................................................................
11
Mercury......................................................................................................................
11
Selenium....................................................................................................................
11
Thallium.....................................................................................................................
12
Fisheries...........................................................................................................................
12
Fish Species Composition..........................................................................................
12
Fish Abundance, Distribution, and Size Structure.....................................................
13
Balanced Indigenous Community..............................................................................
14
FishCommunity Health.............................................................................................
17
BiofoulingMonitoring.....................................................................................................
17
Summaryand Conclusions..........................................................................................................
17
References....................................................................................................................................
18
Duke Energy Progress ii Water Resources

Roxboro Steam Electric Plant
2016 Environmental Monitoring Report
List of Tables
Table
1 Hyco Reservoir environmental monitoring program ..........................................
2 Field sampling and laboratory methods utilized in the Hyco Reservoir
environmental monitoring program.........................................................................
3 Statistical analyses performed on data collected for the Hyco Reservoir
environmental monitoring program.........................................................................
List of Figures
Page
5
C
7
Fiivae Page
1 Hyco Reservoir sampling locations......................................................................... 4
List of Appendices
Appendix Page
1 Depth profiles of water temperature, dissolved oxygen, pH, and specific
conductance at Hyco Reservoir during 2016........................................................... 20
2 Means, ranges, and spatial trends of selected limnological variables from
surface waters of Hyco Reservoir during 2016....................................................... 22
3 Concentrations of chemical variables in surface waters of
Hyco Reservoir during 2016.................................................................................... 23
4 Long-term trends of selected parameters at Station 2B from Hyco Reservoir
from2007 through 2016.......................................................................................... 26
5 Long-term trends of selected parameters at Station 3B from Hyco Reservoir
from2007 through 2016.......................................................................................... 27
6 Long-term trends of selected parameters at Station 4B from Hyco Reservoir
from2007 through 2016.......................................................................................... 28
7 Long-term trends of selected parameters at Station 6B from Hyco Reservoir
from 2007 through 2016.......................................................................................... 29
8 Means and standard errors of trace element concentrations in sediments and
fish by transect from Hyco Reservoir during 2016................................................. 30
Duke Energy Progress iii Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
9 Long-term trends of selenium concentrations in Bluegill, Largemouth Bass, and
White Catfish muscle tissues at Transect 3 and Transect 4 from
Hyco Reservoir from 2007 through 2016................................................................ 31
10 Total number and weight of fish collected with electrofishing from Hyco
Reservoir during 2016............................................................................................. 32
11 Mean catch per hour of fish collected with electrofishing by transect from Hyco
Reservoirduring 2016............................................................................................. 33
12 Length -frequency distributions of Bluegill by transect collected by
electrofishing from Hyco Reservoir during 2016.................................................... 34
13 Length -frequency distributions of Largemouth Bass by transect collected by
electrofishing from Hyco Reservoir during 2016.................................................... 35
14 Length -frequency distributions of Gizzard Shad by transect collected by
electrofishing from Hyco Reservoir during 2016.................................................... 36
15 Relative weight values versus length or Bluegill, Gizzard Shad, and Largemouth
Bass collected by electrofishing at Transect 3 in Hyco Reservoir
during2016................................................................................................................. 37
16 Relative weight values versus length for Bluegill, Gizzard Shad, and
Largemouth Bass collected by electrofishing at Transect 4 in Hyco Reservoir
during2016................................................................................................................. 38
17 Biomass of Bluegill, Largemouth Bass, and total fish collected by electrofishing
from Hyco Reservoir, 2007-2016............................................................................... 39
18 Proportional Size Distribution (PSD) ranges for balanced populations of
Bluegill versus Largemouth Bass and Gizzard Shad versus Largemouth Bass
collected from Hyco Reservoir during 2016............................................................... 40
Duke Energy Progress iv Water Resources

Roxboro Steam Electric Plant
2016 Environmental Monitoring Report
Metric -English Conversion and Units of Measure
Length
1 micron (µm) = 4.0 x 10-5 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 in = 0.62 mile
Area
1 square meter (m2) = 10.76 square feet
1 hectare (ha) = 10,000 in = 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
Duke Energy Progress v Water Resources

Roxboro Steam Electric Plant
2016 Environmental Monitoring Report
Executive Summary
During 2016, surface water temperatures, dissolved oxygen concentrations, pH, specific
conductance, and Secchi disk visibility remained in 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 became
generally stabilized (not increasing) despite some seasonal variation during 2016, primarily due to
lower power plant dispatch rates.
Concentrations of target trace elements, including arsenic, cadmium, copper, mercury, and
selenium, measured in the reservoir surface waters remained below water quality criteria during 2016.
However, selenium concentrations in sediments and in the tissues of Bluegill, Catfish, and
Largemouth Bass continued to be statistically greater at the monitoring station near the discharge
compared to the concentrations of these parameters at the designated upstream comparison
monitoring station.
Despite receiving a thermal discharge, the fish community in Hyco Reservoir remained a self-
sustaining, balanced population of regionally common species during 2016.
Duke Energy Progress vi Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Roxboro Steam Electric Plant
2016 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 for 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 tissues of fish were responsible (i.e., reproductive impairment) for the observed
sport fishery decline in Hyco Reservoir. As a result of elevated selenium concentrations in fish flesh, 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 constructed a dry ash handling system to reduce selenium input into Hyco
Reservoir.
After 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 water after the dry fly ash handling system
began operation and have remained below the North Carolina water quality criterion 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 muscle tissue of each
individual fish species declined below the established threshold level (i.e., 25 µg/g dry weight at the
time). In August 2001, the fish consumption advisory 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 Carolina piedmont impoundment. During 2007, Hyco
Reservoir was subjected to the most extensive drought on record (based on I I0-year USGS streamflow
Duke Energy Progress 1 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
records) in North Carolina, which affected water levels within the reservoir. The water levels decreased
from full pool of 124.9 meters National Geodetic Vertical Datum (NGVD) during May 2007 to slightly
greater than 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 the months of minimal flushing of the reservoir, no overall changes to limnological variables,
including selenium concentrations, were noted during 2007 when compared to previous years. 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 have 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 and 43% in 2015 and lower dispatch rates continued in
2016. Lower dispatch rates over the last three years have resulted in lower discharges of constituents
from the FGD operations as well as lower overall thermal discharge rates to the reservoir.
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. 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.
Hyco 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 m; a normal elevation of 125.1 m 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
Duke Energy Progress 2 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
shoreline is primarily residential, forested, and agricultural. It is classified by the Division of Water
Quality as Class B usage designation, which is defined as suitable for primary recreation, aquatic life
propagation and maintenance, wildlife, and agriculture. Additionally, Hyco Reservoir is classified as
Water Supply V, which is designated as waters used 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 in 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 2 is located in the upper reservoir in the North Hyco arm and
Transects 3 and SHHW are located in the upper reservoir in South Hyco arm. Transect 6 is located in the
lower reservoir adjacent to the spillway.
Objectives and Methods
The primary objective of the Roxboro Plant 2016 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 non -power plant related environmental
factors impacting the aquatic community as well as the impact of non-native aquatic plant and animal
species into 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 3 and 4 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 DEP personnel using in-house procedures and x-ray
defraction equipment in accordance with a study plan approved by NCDEQ. 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.
Duke Energy Progress 3 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
rn
North Hyco River
0 0.5 1
I I
Miles
Cane Creek l Afterbay
Reservoir
- Spillway
9 C� 6
,r J B A
(Outfall #006) Auxiliary Intake �}Gj Main
Dam
Discharge D
2C (Outfa ll #003) a -_Intake
S) Canal
a
4-Gypsum Storage Pad
EC 4 k
Dr
Ash
Landfill
Flush
A► 2� `� �� 1 j �� Pond
B A,
Gypsum
C C Settling ! .i Ash
Pond Pond
.J f` r �. Bioreactor
Person -Ca ell
Lake Authority a
ti J N
3
Cobbs Creek
'B
1
SHHW
1\ 1
1
5F?r343
2 0 075 1 5 3
South
Hyco River Kilometers
Figure 1. Hyco Reservoir sampling locations.
Duke Energy Progress 4 Water Resources

Roxboro Steam Electric Plant 2016 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 213, 313, 413, 613, SHHW
(surface to bottom at 1-m
intervals)
Stations 213, 313, 413, 613, SHHW
(surface)
Stations 213, 313, 413, 6B
Stations 213, 313, 413, 6B
Main intake structure or water
quality station buoys
Stations IA, 1C, 2A, 2C, 3A, 3C,
4A, 4E, 6A, 6C
Transects 3 and 4
+Phytoplankton samples were collected and preserved but were not identified because all chlorophyll a
concentrations measured during 2016 were less than 40 mg/L.
Duke Energy Progress 5 Water Resources

Roxboro Steam Electric Plant 2016 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
a YSe multiparameter instrument. Measurements were taken from the surface to
the bottom at 1-m intervals. Turbidity was measured in the surface waters only
with either a YSe multiparameter instrument or a HACH Model 2100P
turbidimeter. Water clarity was measured with a Secchi disk.
Water Samples were collected with a nonmetallic sampler, transferred to appropriate
chemistry containers, transported to the laboratory on ice, and analyzed according to
applicable analytical methodologies.
Phytoplankton Equal amounts of water from the surface, the Secchi disk transparency depth, and
twice the Secchi disk transparency depth were obtained with a Van Dorn beta
sampler and mixed in a plastic container. A 250-mL composite subsample was
taken and preserved with 5 mL of "MY fixative.
Chlorophyll a Equal amounts of water from the surface, the Secchi disk transparency depth, and
twice the Secchi disk transparency depth were obtained with a Van Dorn beta
sampler and mixed in a plastic container. A 1000-mL composite subsample was
taken. The samples were placed in dark bottles and transported to the laboratory
on ice. In the laboratory, 250-mL subsamples were analyzed (APHA 2012).
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.
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 in-house by x-ray spectrometry (NCDEQ approved Duke Energy SOP).
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.
Duke Energy Progress 6 Water Resources

Roxboro Steam Electric Plant 2016 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)T 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)
One-way, block on month Station
One-way, block on month Station
One-way, block on month Station
One-way, block on month Station
One-way Transect
+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.
Duke Energy Progress 7 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Environmental Monitoring Results for 2016
Limnology
Temperature and Dissolved Oxygen
• Hyco Reservoir generally exhibited a typical thermal stratification pattern throughout 2016
(Appendix 1). Stratification, defined as changes in water temperatures of at least 1°C per meter of water
column depth, was relatively weak reservoir -wide with no large areas of abrupt changes in water
temperature with depth. However, the most pronounced thermal stratification was measured at the
deepest station (Station 4B) and was noted on several occasions during 2016. Several factors
influence thermal stratification at Station 4B including the proximity to the Roxboro Plant discharge,
circulating water from the auxiliary intake system, and natural ambient conditions. Surface water
temperatures at Station 4B ranged from 9.7°C in February to 35.5°C in August, 2016. The coolest
surface water temperature was 7.3°C in February at Station 2B during 2016. The annual mean
surface temperature at Station 4B was 24.4°C, which was significantly greater than the mean surface
temperatures at all the other sampling stations, as expected (Appendix 3). The mean surface water
temperatures at Stations 3B and SHHW were both 20.6°C, or 3.8°C lower than the discharge area on
average.
• All surface water dissolved oxygen concentrations were greater than 5 mg/L throughout Hyco
Reservoir during 2016 (Appendices 1 and 2). The deeper hypolimnetic waters of the reservoir
exhibited oxygen depletion primarily in the warmer months. This phenomenon typically occurs
within monomictic reservoirs of the southeastern United States. However, Hyco Reservoir may not
exhibit as great an oxygen depletion as other reservoirs of the southeast due to the use of an auxiliary
intake for withdrawal of hypolimnetic cooling water by the Roxboro Station. Operation of this intake
results in much of the reservoir remaining well -mixed to greater depths than would be expected
otherwise. Moderately strong clinograde oxygen profiles with bottom waters less than 5 mg/L were
noted during June and August of 2016 at stations 3B and 4B.
Water Clarity Constituents
• Secchi disk transparency was similar among all stations in Hyco Reservoir during 2016
(Appendices 3 and 4). Generally the reservoir, except for the extreme upstream Station SHHW, was
moderately clear with Secchi disk visibility greater than one meter on average. Mean turbidity
values, a related measure of clarity, were also statistically similar among reservoir stations during
2016. The 2016 turbidity ranges were within ranges observed in previous years (DEP 2016a).
Duke Energy Progress 8 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Nutrients and Phytoplankton Biomass
• During 2016, the annual mean total ammonia, total nitrogen, nitrite -nitrate nitrogen, and total
phosphorous concentrations were similar among the stations and varied by relatively small amounts
(Appendices 2 and 3). The minor variations of these constituent concentrations among the stations
were not considered to be important to the trophic status of the reservoir. Total organic carbon
concentrations were low and consistent throughout the reservoir. Taking these constituents altogether
reflect the moderate trophic status of Hyco Reservoir (NCDENR 2010).
• The annual mean chlorophyll a (a measure of phytoplankton biomass) concentration at Station 3B
was statistically greater than concentrations at Stations 2B, 4B and 6B during 2016 (Appendix 3).
Chlorophyll a was not measured at SHHW as part of the monitoring plan. All chlorophyll a
measurements in Hyco Reservoir during 2016 were below the North Carolina water quality standard
of 40 µg/L for chlorophyll a (15A NCAC 02B.0211, May 2007).
Ions, Hardness, and Specific Conductance
• The 2016 annual mean concentrations of most of the major ions, specific conductance, total dissolved
solids concentrations and hardness concentrations varied statistically among sampling stations
(Appendices 2 and 3). These constituents generally decrease in concentrations or measured values
with the following pattern 4B>6B>2B>3B>SHHW. This concentration pattern has been typically
observed since the FGD operations commenced in 2008. From 2013 through 2016, fluctuations of
these parameters reflected the inconsistent dispatching of the Roxboro Plant (Appendices 4-7).
Alkalinity and pH
• Mean total alkalinity concentrations within year were similar among all the stations on Hyco
Reservoir during 2016 with overlapping concentration ranges (Appendices 2 and 3). Individual
values ranged from 19 to 38 mg/L in surface waters during 2016 with the greatest measured value at
Station SHHW.
• Hyco Reservoir generally exhibited median pH values slightly above neutral with circumneutral
ranges within approximately one pH unit of neutral throughout the reservoir during 2016
(Appendices 1 and 2). Surface water pH values ranged from 6.1 to 8.0 among stations. 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.
Duke Energy Progress 9 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Trace Elements
Arsenic
• Annual mean arsenic concentrations at Stations 2B, 4B and Station 6B were statistically greater
compared to the concentrations at the upper reservoir Stations 3B and SHHW during 2016
(Appendices 2-7). While the lower reservoir arsenic concentrations were slightly elevated 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 criteria (150 µg/L chronic/340 µg/L acute
aquatic life and 10 µg/L human health). Long-term trends of arsenic concentrations from 2007-2016
at all stations exhibited simple seasonal fluctuations in concentrations.
• Arsenic concentrations in the sediments at Transect 4 were elevated above concentrations considered
to be background of 3-13µg/g dry weight (F6rstner and Wittmann 1981; Salomons and F6rstner 1984;
and Martin and Hartman 1984) during 2016 (Appendix 8). All concentrations measured at Transect 3
were below the Laboratory Reporting Limit (LRL) of 6.2 µg/g. This pattern of arsenic in sediments
has been observed historically in the reservoir (PEC 2012 and DEP 2016a). Bluegill from Transect 4
had significantly greater mean arsenic concentrations in liver compared to liver concentrations in the
same species from Transect 3 during 2016. However, these liver values were not considered to be of
concern to aquatic life or of human health concern since this tissue is not generally consumed by
humans. The mean arsenic concentrations in both Bluegill and Largemouth Bass at Transect 4 were
statistically greater than those at Transect 3. These mean values were only slightly greater, and when
converted to wet weight values were below the EPA recreational fisherman screening level (i.e., 1.2
µg/g wet weight) for human consumption (NCDEQ 2013).
Cadmium
• Annual mean cadmium concentrations in sediments and fish tissues at Transect 3 and 4 were all
below the LRL during 2016 (Appendix 8).
Copper
• The annual mean copper concentration in Hyco Reservoir surface waters was statistically greater at
Transect 2B compared to concentrations at Transects 3B and SHHW during 2016 (Appendices 2
and 3). Mean copper concentrations downstream at Stations 4B and 6B were similar to
concentrations at all other stations. These mean copper values were below the North Carolina water
quality criterion of 3.6 µg/L. Long-term trends have shown no pattern of accumulation related to
FGD operations (Appendices 4-7).
Duke Energy Progress 10 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
• The annual mean copper concentration in sediment near the power plant discharge (Transect 4) was
statistically greater than the mean copper concentration at Transect 3 (South Hyco Creek arm) during
2016, as expected (Appendix 8).
• Annual mean copper concentrations in Bluegill and Largemouth Bass liver tissues were statistically
greater at Transect 4 compared to mean concentrations in Bluegill and Largemouth Bass liver tissues
at Transect 3 during 2016 (Appendix 8). In muscle tissues, the mean copper concentration in Bluegill
at Transect 3 was greater than the mean concentration in Bluegill at the discharge (Transect 4).
Manganese
• Annual mean manganese concentrations in surface waters of Hyco Reservoir were statistically similar
among all reservoir stations during 2016 (Appendices 2 and 3). Manganese concentrations ranged
widely in the reservoir with the greatest concentrations observed in surface waters at Stations 413 and
6B during December. This observation at these deep water stations was possibly related to seasonal
edaphic processes and stratification phenomena such as turnover for this naturally occurring element
(Wetzel 1975) rather than to power plant operations.
Mercury
• The annual mean mercury concentrations in surface waters were statistically similar among all
stations during 2016 (Appendices 2 and 3). All individual mercury concentrations measured
throughout the reservoir were below the State water quality criterion of 12 ng/L.
• Annual mean mercury concentrations in sediments at Transects 3 and 4 were less than the LRLs
during 2016 (Appendix 8).
• Annual mean mercury concentrations in fish tissues were statistically similar between Transect 3 and
Transect 4 fish during 2016 (Appendix 8). Also, when converted to fresh weight values, all annual
mean and individual measured mercury concentrations in muscle tissues during 2016 were 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 2016, annual mean selenium concentrations in surface waters of Hyco Reservoir were
statistically similar among all stations for the first time since 2008, the year FGD operations began
Duke Energy Progress 11 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
(Appendices 2 and 3). Further, all annual mean selenium concentrations were below 1 µg/L reservoir -
wide, well below the North Carolina water quality criterion of 5 µg/L for freshwater (Appendices 4-
7).
• The mean selenium concentrations in sediments and all fish tissues, except for White Catfish liver,
were statistically greater at Transect 4 compared to concentrations at Transect 3 during 2016
(Appendix 8). Since 2013, selenium concentrations in Bluegill and Catfish muscle tissues have
trended lower at Transect 4 while Largemouth Bass showed a slight increase from the 2015 selenium
muscle tissue concentrations (Appendix 9). All the values in edible flesh during 2016, as well as the
long-term observation period, were well below the North Carolina human health consumption
advisory level (50 µg/g dry weight, North Carolina Department of Health and Human Services,
2008).
Thallium
• All thallium measurements were below the LRL of 0.1 µg/L during 2016 (Appendices 2 and 3).
Fisheries
Fish Species Composition
• Twenty different fish species belonging to seven families were collected from Hyco Reservoir with
electrofishing during 2016 (Appendices 10 and 11). The sunfish family (Centrarchidae) dominated
the fish population with six fish species. Catostomidae (suckers) followed this family with five
species and bullhead catfishes (Ictaluridae) and minnows (Cyprinidae), both with four fish species
each, were next in the order of dominance. 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. Black Crappie and Channel Catfish were also prevalent predators during 2016 and
Yellow Perch were collected in reasonably good numbers. The open water schooling species Gizzard
Shad and Threadfin Shad were observed in abundance in Hyco Reservoir providing ample forage for
the predator species during 2016.
• 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 10 and 11). The presence of these
introduced species in Hyco Reservoir was unrelated to the operation of the Roxboro Plant. Blue
Duke Energy Progress 12 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Tilapia in particular, are declining in numbers due to their intolerance of cold water temperatures as
the Roxboro Plant continues to be dispatched at lower rates. 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 2 with 17 species during 2016
(Appendix 11). Transects 1 and 3 exhibited the next most diverse fish assemblages with 15 species
each during 2016 species followed by Transect 6 with 13 species. Transect 4 had 13 species collected
in 2016, 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 by
Herrings (Clupeidae) and Bullhead Catfishes (Ictaluridae) during 2016 (Appendices 10 and 11). The
sunfish family comprised 66% of the total annual electrofishing catch in 2016. Herrings comprised
29% and Bullhead Catfishes comprised 2% of the total fish catch during 2016. Bluegill was the
single most abundant fish species present with 46% of the total catch in 2016. Young -of -year
Threadfin Shad was the second most abundant fish species during 2016 representing 18% of the total
fish caught but comprising only 1 % of the of the total biomass. Largemouth Bass was the third most
abundant species during 2016 with 12% of the total catch while comprising 39% of the total biomass.
Total fish number and biomass reservoir -wide during 2016 were consistent with values observed in
recent years (DEP 2016a).
• The dominant species Bluegill was collected in greatest numbers at Transect 1 (Cobbs Creek) during
2016 (Appendices 11 and 12). The mean Bluegill catch by transect arranged in decreasing order were
Transects 1>4>3>6>2 during 2016.
• Bluegill reproduction was good throughout the reservoir in 2016 as indicated by their length -
frequency distributions at all transects, except at Transect 2 (Appendix 12). Transect 2 has an
abundance of large flat open areas with little cover and was likely the reason for fewer small Bluegill
being collected. There is a limited amount of shoreline rip rap habitat in shallow areas of this
transect that affords smaller Bluegill cover, therefore, small fish can be under represented annually in
the electrofishing catch. The size class distributions of Bluegill were similar among all transects
except at Transect 2 where most fish were greater than 75 mm. This pattern of fewer small Bluegill at
Transect 2 is typical of the electrofishing catches at this reservoir location (DEP 2016a). The mean
Duke Energy Progress 13 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Relative Weight (Wr) values, an indirect measure of condition, were 84 at Transect 3 and 85 at
Transect 4 (100 is optimal) for Bluegill (Appendices 15 and 16). The suboptimal Wr values may be
related to competition for food for this numerically dominant species. On average, most fish rarely
achieve optimal condition in natural settings.
• Largemouth Bass of all size classes were well -represented throughout the reservoir during 2016
(Appendix 13). This species had adequate reproductive success during 2016 as represented by
reasonable numbers of individual fish less than 150 mm at Transects 1, 4, and 6. Transects 2 and 3
appeared less successful with fewer small fish present in electrofishing catches. Again this
observation could be habitat related. In general, Largemouth Bass were fairly consistent in size on
average throughout the reservoir during 2016 with an overall reservoir mean length of 270 mm for
2016. The mean Relative Weight (Wr) values for Largemouth Bass at Transect 3 during 2016 (Wr =
87) were somewhat better compared to values at Transect 4 during 2016 (Wr=85) (Appendices 15
and 16). The upstream locations tend to be more productive compared to the large open water
downstream area of the reservoir, which likely is one reason for differences in Wr values.
• Gizzard Shad were well represented and collected in similar numbers throughout Hyco Reservoir
during 2016 (Appendix 14). However, as observed in recent years (DEP 2016), Gizzard Shad
collected from Hyco Reservoir were mostly greater than 200 mm during 2016. Young -of -year
Gizzard Shad are not efficiently collected by electrofishing due to the inherent geartype bias against
smaller schooling fish. Gizzard Shad Wr mean values of 91 at both Transect 3 and 4 were considered
to be reasonably good for this mesotrophic reservoir (Appendices 15 and 16). Similar mean Wr
values for Gizzard Shad in the discharge area versus upstream helps support the conclusion of
minimal impacts to the fishery by power plant operations during 2016.
• Redear Sunfish was reasonably well distributed throughout Hyco Reservoir during 2016
(Appendix 11). 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 2016.
Balanced, Indigenous Community
• A "Balanced, Indigenous Community (BIC)," particularly as it relates to thermal impacts due to
power plant operations, is represented by a diverse aquatic community that is self-sustaining with an
Duke Energy Progress 14 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
adequate food supply and is not dominated by pollution tolerant species. However, man-made
impoundments for the purpose of providing cooling water for power plants are by definition artificial
systems and thus the term indigenous may be inappropriate when applied to them. Indigenous refers
to presence of species through natural processes without any intervention by man, which is not the
case for impoundment aquatic populations. Anderson and Neumann (1996), in their review of indices
of balance and condition, stated "In contrast with natural systems, many fisheries are managed within
artificial systems such as impoundments. These artificial systems contain introduced species because
no fish communities are native to these newly created (from an evolutionary perspective) waters."
DEP agrees with this statement. The riverine communities that once existed in the system prior to
impoundment generally decline and are displaced by lentic communities of species common in the
region. Many species in impoundments show up through introductions by resource agency stocking
activity, by anglers, and by other means. However, while the indigenous aspect of impoundments is
questionable, the communities can be assessed in terms of being self-sustaining, in balance with food
supply, and being composed of diverse species common in the region that are not present due to their
tolerance of pollution, thermal or otherwise.
• As indicated above, 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, White Bass,
and Channel Catfish continue to exist in Hyco Reservoir. 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
during 2016 (Appendixl3). 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 also exhibited the necessary presence of young -of -year (generally < 80 mm fish) and year
class 1+ fish (generally > 80 mm to 125 mm fish) during 2016 (Appendices 12). While electrofishing
may bias against small schooling species such as Gizzard Shad and Threadfin Shad, the presence of
good numbers of adult fish year after year indicate adequate reproduction and recruitment of this prey
species.
• Comparing the overall long-term biomass of Bluegill, Largemouth Bass, and total fish shows relative
Duke Energy Progress 15 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
consistency from 2007 through 2016 (Appendix 17). This observation is a key component of a
sustaining BIC represented in Hyco Reservoir.
• Fish populations in balance can also be indicated by accepted Proportional Size Distribution (PSD)
index values. 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 Largemouth Bass
population existed in the reservoir while the Bluegill population fell slightly out of the range for
balanced populations (Appendix 18). While no balance range has been determined for Gizzard Shad,
it is interesting to note that comparing the PSD of Largemouth Bass to Gizzard Shad PSD shows a
very nice relationship of the stock and quality size fish of each species in Hyco Reservoir.
• The use of a regionally suitable reference water body with similar characteristics (except for an
absence of a thermal input) for comparison purposes is another way to determine the status of BIC.
Mayo Reservoir is a reasonable choice for a reference system because of its nearby location, size, and
associated power plant with both ash pond and FGD system discharges but lack of a thermal
discharge. Mayo Reservoir is also considered to have a balanced fish community, particularly for
Largemouth Bass. Hyco Reservoir (on average mesotrophic; NCDENR 2010) was a little more
diverse with 20 species and productive with 251 fish/hour compared to Mayo Reservoir with 16
species and 181 fish/hour (DEP 2016b) which is oligotrophic to mesotrophic (NCDENR 2010). This
difference is likely due to Hyco Reservoir's larger watershed and stream flow.
• Both reservoirs contain several species introduced either intentionally or accidentally (i.e., through
agency stocking programs or by anglers). However, species compositions and diversity of both fish
communities remain basically similar with primarily regionally common fish species. Other minor
apparent differences in diversity between the two communities exist such as the presence of Chain
Pickerel in Mayo Reservoir but not in Hyco Reservoir electrofishing catches. This difference is
considered likely related to a greater abundance of aquatic vegetation, a preferred habitat of Chain
Pickerel, in Mayo Reservoir. Based on the fishery sampling of Hyco Reservoir the fish community
present is not a result of thermal influence. One exception is that two truly exotic species present in
Hyco Reservoir, the Blue Tilapia and Redbelly Tilapia that were accidentally released, are able to
survive cold winters strictly because of the thermal discharge. Again, as the Roxboro Plant continues
to be dispatched at lower capacity factors annually, these species may decline in numbers through
time.
Duke Energy Progress 16 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Fish Community Health
• No fish kills were observed or reported from Hyco Reservoir during 2016.
Biofouling Monitoring
• No zebra mussels (Dreissena polymorpha) or quagga mussels (D. bugensis) were found in Hyco
Reservoir during 2016. 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 2016.
The 2016 annual mean reservoir temperatures in surface waters continued to be within the ranges
typically observed in Hyco Reservoir.
FGD operations continued to affect several water chemistry parameters nearer the power plant
discharge compared to those at historical background stations in Hyco Reservoir during 2016;
however, with lower power plant dispatch rates these constituent concentrations have trended down.
In fish tissues, selenium concentrations also trended down in Bluegill and White Catfish while
Largemouth Bass concentrations were slightly higher. The edible flesh selenium concentrations of all
fish species sampled remained well below the North Carolina Department of Health and Human
Services consumption advisory level of 50 µg/g (dry weight).
Fish species composition, abundance, and distribution in Hyco Reservoir during 2016 were
similar to that of previous years. Bluegill remained the dominate fish species followed by
Largemouth Bass, Threadfin Shad, Gizzard Shad, Redear Sunfish, and Black Crappie within the
reservoir. 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.
Duke Energy Progress 17 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
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.
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. 2016a. Roxboro Steam Electric Plant 2014-2015 environmental monitoring report. Duke Energy
Progress, Raleigh, NC.
DEP. 2016b. Mayo Steam Electric Plant 2016 environmental monitoring report. Duke Energy Progress,
Raleigh, NC.
Gabelhouse, D. W., Jr. 1984. A length -categorization system to asses fish stocks. N. Amer. J. Fish.
Manag. 4:371-384.
NCDENR. 2010. Roanoke River basinwide assessment report. Biological Assessment Unit.
North Carolina Department of Environment and Natural Resources. Division of Water Quality.
Water Quality Section. Environmental Sciences Branch. Raleigh, NC.
NCDENR. 2013. Standard Operating Procedures; Fish Tissue Assessments. North Carolina Department
of Environment and Natural Resources. Division of Water Resources, Environmental Sciences
Section, Intensive Survey Branch. Raleigh, NC.
Duke Energy Progress 18 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Page, L. M., H. Espinsoa-Perez, 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.
R. M. Neumann, C. S. Guy, and D. W. Willis. 2012. Length, Weight, and Associated Indices, In
Fisheries Techniques, Third Edition. American Fisheries Society, Bethesda, Maryland.
Salomons, W., and U. Forstner. 1984. Metals in the hydrocycle. Springer-Verlag, New York, NY.
Wetzel, R. G. 1975. Limnology. W. B. Saunders Co. Philadelphia, PA.
Duke Energy Progress 19 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Appendix 1. Depth profiles of the water temperature (°C), dissolved oxygen (mg/L), pH, and
specific conductance (µS/cm) at Hyco Reservoir during 2016.
February 3, 2016
Temperature
Dissolved oxygen
pH
Specific
Depth
2B
3B
4B
6B
SHHW
2B
3B
4B
6B
SHHW
2B
3B
4B
6B
SHHW
2B
3B
4B
6B SHHW
0.2
7.3
7.0
9.7
10.7
8.3
11.3
11.8
9.9
10.1
11.7
6.1
6.1
6.6
6.1
6.2
115
79
160
155
80
1.0
7.3
6.8
9.7
10.7
8.3
11.4
11.7
9.9
10.1
11.5
6.1
5.9
6.6
6.1
5.9
114
79
160
155
80
2.0
6.9
6.6
9.7
10.7
8.0
11.5
11.7
9.8
10.1
11.2
5.7
5.8
6.6
6.1
6.1
111
79
160
155
80
3.0
6.2
6.4
9.6
10.7
5.7
11.5
11.4
9.8
10.0
11.0
5.4
6.0
6.5
6.1
5.2
103
79
160
155
79
4.0
5.3
5.3
9.6
11.6
11.0
9.8
5.3
5.1
6.5
95
80
160
5.0
5.1
5.2
9.5
11.6
10.1
9.7
5.4
5.1
6.4
93
81
159
6.0
5.1
5.2
9.4
11.5
9.9
9.6
5.6
5.1
6.4
94
81
157
7.0
9.4
9.6
6.4
157
8.0
9.2
9.5
6.2
156
9.0
9.0
9.3
6.1
152
10.0
8.4
9.3
6.1
143
11.0
8.1
7.8
5.9
140
April 21, 2016
Temperature
Dissolved oxygen
pH
Specific conductance
Depth
2B
3B
4B
6B
SHHW
2B
3B
4B
6B SHHW
2B
3B
4B
6B
SHHW
2B
3B
4B
6B SHHW
0.2
19.6
20.5
23.4
19.8
22.1
10.2
10.3
9.4
10.2 10.0
7.9
7.7
7.5
7.7
8.2
121
91
141
137 95
1.0
19.2
20.2
23.3
19.4
19.9
10.1
10.3
9.4
10.2 9.9
8.0
7.5
7.4
7.9
8.1
122
91
141
137 94
2.0
19.2
17.7
20.7
19.2
16.8
10.0
10.0
9.3
10.1 4.5
8.0
7.5
7.3
7.9
8.0
122
90
136
137 97
3.0
18.4
15.3
17.6
19.0
9.4
0.2
8.4
9.8
7.7
7.4
7.3
8.1
116
91
127
137
4.0
16.2
15.2
16.1
7.1
2.9
7.8
7.7
7.5
7.3
107
93
127
5.0
15.8
15.5
5.4
7.5
7.6
7.3
106
123
6.0
15.7
15.2
5.1
7.4
7.6
7.3
107
127
7.0
14.8
7.3
7.3
129
8.0
14.7
6.8
7.3
131
9.0
14.4
5.6
7.3
134
10.0
14.3
2.6
7.3
140
June 3, 2016
Temperature
Dissolved oxygen
pH
Specific conductance
Depth
2B
3B
4B
6B
SHHW
2B
3B
4B
6B SHHW
2B
3B
4B
6B
SHHW
2B
3B
4B
6B
SHHW
0.2
29.7
31.0
31.3
30.5
30.9
8.7
9.8
6.9
7.5
10.4
8.3
8.8
7.3
7.7
8.9
137
97
158
149
140
1.0
29.0
27.6
30.4
29.7
27.4
8.6
9.1
6.6
7.4
9.6
8.4
8.5
7.2
7.7
8.3
140
99
155
150
94
2.0
28.3
27.0
29.8
29.4
26.8
7.8
6.7
6.4
7.4
5.0
7.6
7.3
7.2
7.6
7.2
137
98
155
149
95
3.0
28.1
25.9
28.8
28.4
26.1
6.9
2.1
5.1
6.9
1.0
7.3
7.2
7.1
7.4
7.2
135
98
152
147
106
4.0
27.9
22.0
28.2
6.2
0.2
4.5
7.4
7.1
7.0
134
127
150
5.0
27.4
17.6
26.9
5.2
0.3
3.0
7.3
7.3
7.0
130
140
137
6.0
26.4
25.9
1.2
2.5
7.2
7.0
136
142
7.0
20.8
0.2
7.1
139
8.0
17.5
0.2
7.2
147
9.0
17.4
0.2
7.1
157
10.0
16.3
0.2
7.2
173
Duke Energy Progress 20 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Appendix 1. (continued)
Auiust 12, 2016
Temperature
Dissolved oxygen
pH
Specific conductance
Depth
2B
3B
4B
6B
SHHW
2B
3B
4B
6B
SHHW
2B
3B
4B
6B
SHHW
2B
3B
4B
6B
SHHW
0.2
31.5
30.4
35.5
32.1
29.9
8.3
8.8
6.6
7.0
9.0
8.2
8.4
7.7
7.6
8.4
188
102
223
201
100
1.0
31.5
30.0
35.4
32.1
29.8
8.2
8.5
6.5
6.9
9.1
8.2
8.2
7.6
7.6
8.3
188
102
223
201
99
2.0
31.3
29.0
34.9
31.9
28.6
8.0
6.0
5.6
6.8
7.1
8.1
7.2
7.5
7.6
7.4
187
102
223
201
96
3.0
30.3
27.0
32.3
31.2
26.2
6.2
3.0
5.0
6.6
1.1
7.3
6.8
7.3
7.5
6.7
177
91
199
200
93
4.0
29.5
25.7
31.0
5.2
0.4
4.5
7.1
6.7
7.2
170
86
195
5.0
29.1
22.8
30.5
4.5
0.3
4.2
7.0
6.6
7.2
164
119
187
6.0
27.6
20.7
29.9
0.4
0.3
3.0
6.7
6.8
7.1
140
157
170
7.0
29.4
2.7
7.1
165
8.0
28.6
2.1
7.2
164
9.0
26.1
0.3
7.5
180
10.0
19.5
0.3
7.4
192
11.0
18.4
0.3
7.7
223
October 3, 2016
Temperature
Dissolved oxygen
pH
Specific conductance
Depth
2B
3B
4B
6B
SHHW
2B
3B
4B
6B
SHHW
2B
3B
4B
6B SHHW
2B
3B
4B
6B
SHHW
0.2
27.5
25.9
31.5
28.3
9.7
7.4
7.7
11.1
9.7
9.9
8.2
8.0
7.4
7.5
8.1
222
142
242
230
102
1.0
26.8
25.4
30.9
28.0
9.7
7.5
7.6
10.6
9.7
9.9
8.2
7.8
7.4
7.5
7.8
220
137
239
230
109
2.0
26.5
23.8
29.9
27.7
9.5
6.1
7.6
7.5
9.5
7.0
8.1
6.8
7.1
7.5
7.0
220
124
233
230
103
3.0
26.0
23.4
28.6
27.5
8.5
4.4
6.8
3.1
8.5
4.3
7.7
6.5
6.9
7.3
6.9
212
92
220
227
92
4.0
25.7
23.0
28.1
8.1
4.1
8.1
2.9
7.5
6.5
6.9
208
82
215
5.0
25.5
22.0
26.8
7.7
2.9
7.7
0.4
7.3
6.5
6.8
204
76
203
6.0
24.0
21.8
26.3
1.7
2.8
1.7
0.4
6.9
6.5
6.8
137
79
198
7.0
26.1
2.6
6.8
197
8.0
25.4
1.5
6.8
171
9.0
24.5
1.1
6.8
160
10.0
24.1
0.5
7.4
216
11.0
23.3
0.5
7.6
December 13, 2016
Temperature
Dissolved oxygen
pH
Specific conductance
Depth
2B
3B
4B
6B
SHHW
2B
3B
4B
6B SHHW
2B
3B
4B
6B
SHHW
2B
3B
4B
6B
SHHW
0.2
11.4
8.8
14.8
13.2
6.9
9.6
10.9
8.8
9.1 11.2
7.3
7.4
7.5
7.4
7.0
179
123
187
184
118
1.0
10.5
8.6
14.6
13.2
6.8
9.7
10.8
8.6
9.1 11.1
7.3
7.4
7.4
7.4
7.0
173
123
186
184
118
2.0
10.2
8.7
14.5
13.0
6.5
9.7
10.7
8.5
8.9 10.8
7.2
7.4
7.4
7.4
7.0
171
123
186
184
117
3.0
10.1
8.7
14.4
12.5
6.5
9.8
10.7
8.4
8.8 11.2
7.2
7.4
7.4
7.3
7.1
171
123
186
183
117
4.0
10.0
8.7
14.3
9.7
10.7
8.3
7.1
7.4
7.4
170
123
185
5.0
9.7
8.7
14.0
9.6
10.8
8.2
7.1
7.4
7.3
167
123
184
6.0
9.5
8.7
13.8
9.5
10.8
8.2
7.1
7.4
7.3
166
123
183
7.0
13.6
8.1
7.3
183
8.0
13.2
8.0
7.3
181
9.0
12.4
7.8
7.2
177
10.0
12.4
7.6
7.2
177
Duke Energy Progress 21 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Appendix 2. Means, ranges, and spatial trends of selected limnological variables from surface
waters of Hyco Reservoir during 2016.+
Station 2B
Station 3B
Station 4B
Station 6B
Station SHHW
Variable
Mean
Range
Mean
Range
Mean
Range
Mean
Range
Mean
Range
Temperature (°C)
21.2b`
7.3-31.5
20.6`
7.0-31.0
24.4a
9.7-35.5
22.4b
10.7-32.1
20.6`
6.9-30.9
Dissolved oxygen (mg/L)
9.6b
8.3-11
1Oab
8.8-12
8.2°
6.6-9.9
8.6`
7.0-10
lla
9.0-12
pH (median value)
8.0
6.1-8.3
7.8
6.1-8.8
7.4
6.6-7.7
7.5
6.1-7.7
8.1
6.2-8.9
Total dissolved solids (mg/L)
115'
89-133
75b
60-84
121a
96-147
110a
72-140
66b
55-82
Turbidity (NTL))
9.6
1.9-29.0
9.5
3.2-28.0
7.6
1.2-19.0
6.9
1.3-17.0
11
5-21
Secchi disk transparency (m)
1.2
0.7-1.8
0.9
0.5-1.4
1.3
0.9-1.8
1.6
0.9-2.9
0.8
0.5-0.9
Chlorophyll a (µg/L)
5.9b
0.9-11
16a
1.2-36
4.Ob
1.2-5.1
2.8b
0.6-5.4
NS
NS
Nutrients (mg/L)
Ammonia-N
0.01
<0.01-0.01
0.01
<0.01-0.01
0.01
<0.01-0.03
0.01
<0.01-0.02
0.01
<0.01-0.06
Nitrate + Nitrite N
0.05
<0.02-0.14
0.05
<0.02-0.26
0.08
<0.02-0.19
0.11
<0.02-0.37
0.05
<0.02-0.24
Total nitrogen
0.43
0.32-0.59
0.62
0.22-1.50
0.37
0.19-0.54
0.39
0.21-0.55
0.46
<0.12-0.87
Total phosphorus
0.027
<0.005-0.081
0.034
0.022-0.059
0.031
0.007-0.083
0.020
<0.005-0.055
0.038
0.012-0.058
Total organic carbon (mg/L)
5.8
4.5-8.1
5.8
5.4-7.1
5.7
4.5-7.8
5.7
4.8-7.4
5.8
4.2-7.6
Ions (mg/L)
Calcium
14b
10-19
8.2`
5.6-12.0
16'
12-21
15ab
11-20
7.6°
5.7-9.0
Chloride
19b
11-30
8.2°
4.5-15.2
24'
16-33
23ab
16-31
6.0`
4.4-7.8
Magnesium
6.2'
4.6-8.7
3.9b
2.9-5.6
7.1'
5.3-9.8
6.7a
5.1-9.2
1 3.7b
2.8-4.2
Sodium
< 5.0
N/A
< 5.0
N/A
< 5.0
N/A
< 5.0
N/A
< 5.0
N/A
Sulfate
14b
10-18
7.2`
5.7-9.3
17a
14-20
16'
14-19
6.0°
5.1-6.9
Total alkalinity (mg/L as CaCO3)
25
21-30
26
19-29
25
21-31
25
21-30
29
19-38
Hardness (mg equiv. CaCO3/L)
59b
43-83
37'
26-53
68a
51-93
65ab
49-89
34`
26-40
Specific conductance (µS/cm)
160a
115-222
106b
79-142
185'
141-242
176'
137-230
106b
80-140
Trace elements (µg/L)
Arsenic
1.11
0.7-1.5
0.6b
0.3-0.8
1.3'
0.8-1.8
1.2'
0.8-1.7
0.5b
0.3-0.8
Boron
407b
198-692
120'
<50-306
534'
320-805
493ab
303-736
59-`
<50-124
Copper
2.0'
0.8-3.8
1.2b
<0.5-1.9
1.6ab
0.8-2.6
1.7ab
0.8-2.6
1.2b
<0.5-1.8
Manganese
71
21-202
57
28-86
144
34-336
105
26-325
74
44-131
Mercury§(ng/L)
2.4
0.6-6.5
2.6
0.9-6.8
3.2
1.7-6.2
3.6
0.8-9.6
2.7
1.1-5.5
Selenium
0.7
<0.5-1.0
< 0.5
N/A
0.7
0.6-0.9
0.6
<0.5-0.9
< 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 22 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Appendix 3. Concentrations of chemical variables in surface waters of Hyco Reservoir during
2016. +`[
Station 2B
Month
TDS Turbidity
Secchi
Chlorophyll a
NH3-N
NO3 + NO2 -N
TN
TP
TN:TP
TOC
depth
Feb
119
29
0.7
0.9
< 0.01
0.12
0.48
0.081
5.9
8.1
Apr
89
16
0.9
7.5
0.01
< 0.02
0.59
0.039
15
6.4
Jun
102
3.1
0.7
3.9
< 0.01
< 0.02
0.39
0.023
17
5.7
Aug
129
2.5
1.8
3.9
< 0.01
< 0.02
0.32
0.010
32
5.0
Oct
133
1.9
1.7
11.4
0.01
< 0.02
0.35
0.009
40
4.5
Dec
115
4.9
1.2
7.5
< 0.01
0.14
0.47
< 0.005
5.3
Month
Ca2+
Cl-
Mg2+
Na
SO42"
Alkalinity
Hardness
As
B
Cu
Feb
9.7
11
4.7
< 5.0
9.9
21
44
0.7
198
3.0
Apr
9.8
12
4.6
< 5.0
11
24
43
0.7
214
3.8
Jun
12
15
5.3
5.1
12
25
51
0.8
269
2.4
Aug
16
24
6.8
5.4
16
28
68
1.3
530
1.1
Oct
19
30
8.7
5.5
18
30
83
1.5
692
0.9
Dec
15
25
7.3
< 5.0
16
24
67
1.4
540
0.8
Month
Hg
Mn
Se
Tl
Feb
0.0065
78
0.6
< 0.10
Apr
0.0035
36
0.6
< 0.10
Jun
0.0013
19
< 0.5
< 0.10
Aug
0.0009
37
0.8
< 0.10
Oct
0.0006
32
0.8
< 0.10
Dec
0.0015
36
1.0
< 0.10
Station 3B
Month
TDS Turbidity
Secchi
Chlorophyll a
NH3-N
NO3 + NO2 -N
TN
TP
TN:TP
TOC
depth
Feb
84
28
0.7
1.2
< 0.01
0.26
0.56
0.059
9.5
7.1
Apr
60
5.3
1.3
6.0
< 0.01
< 0.02
0.40
0.033
12
5.4
Jun
78
4.9
0.7
14.7
< 0.01
< 0.02
1.50
0.038
39
6.1
Aug
62
3.2
1.4
17.3
< 0.01
< 0.02
0.47
0.022
21
5.4
Oct
83
8.3
0.5
18.0
< 0.01
< 0.02
0.56
0.030
19
5.4
Dec
80
7.5
1.0
35.9
0.01
< 0.02
0.22
0.022
10
5.6
Month
Cat+
Cl-
Mg2+
Na
SO42-
Alkalinity
Hardness
As
B
Cu
Feb
5.6
4.5
2.9
< 5.0
6.4
19
26
0.4
< 50
1.9
Apr
6.7
5.0
3.2
5.3
6.7
27
30
0.3
< 50
1.4
Jun
7.5
4.7
3.8
5.2
5.9
29
34
0.7
< 50
1.5
Aug
7.8
7.4
3.7
< 5.0
5.7
28
35
0.8
104
1.2
Oct
12
15
5.6
< 5.0
9.3
29
53
0.8
306
0.9
Dec
9.4
13
4.4
< 5.0
9.0
27
41
0.6
232
< 0.5
Month
Hg
Mn
Se
Tl
Feb
0.0068
86
< 0.5
< 0.10
Apr
0.0040
28
< 0.5
< 0.10
Jun
0.0013
74
< 0.5
< 0.10
Aug
0.0009
42
0.5
< 0.10
Oct
0.0013
51
0.7
< 0.10
Dec
0.0011
63
< 0.5
< 0.10
Duke Energy Progress
23
Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Appendix 3. (continued)
Station 4B
Month
TDS
Turbidity
Secchi
Chlorophyll a
NH3-N
NO3 + NOZ -N
TN
TP
TN:TP
TOC
depth
Feb
141
19
0.9
1.2
< 0.01
0.19
0.41
0.083
4.9
7.8
Apr
113
13
1.1
7.2
0.02
0.07
0.54
0.035
15
6.1
Jun
106
4.8
0.9
5.1
< 0.01
< 0.02
0.19
0.022
8.6
5.3
Aug
96
1.9
1.7
4.2
< 0.01
0.03
0.31
0.010
31
4.9
Oct
147
1.2
1.8
4.5
< 0.01
0.03
0.41
0.028
15
4.5
Dec
125
5.8
1.6
1.8
0.03
0.17
0.35
0.007
48
5.3
Month
Caz+
Cl"
Mgz+
Na
S042-
Alkalinity
Hardness
As
B
Cu
Feb
14
20
6.1
< 5.0
15
21
59
0.9
440
2.6
Apr
12
16
5.3
< 5.0
14
22
51
0.8
320
2.4
Jun
14
19
6.1
5.1
15
25
59
0.9
364
1.9
Aug
19
31
8.0
5.6
20
29
81
1.7
708
1.2
Oct
21
33
9.8
5.6
20
31
93
1.8
805
0.9
Dec
15
28
7.2
< 5.0
17
24
67
1.5
568
0.8
Month
Hg
Mn
Se
Tl
Feb
0.0062
124
0.7
< 0.10
Apr
0.0040
34
0.7
< 0.10
Jun
0.0024
184
0.6
< 0.10
Aug
0.0024
97
0.8
< 0.10
Oct
0.0017
87
0.7
< 0.10
Dec
0.0023
336
0.9
< 0.10
Station 6B
Month
TDS
Turbidity
Secchi
Chlorophyll a
NH3-N
NO3 + NOZ -N
TN
TP
TN:TP
TOC
depth
Feb
136
17
0.9
0.6
< 0.01
0.19
0.43
0.055
7.8
7.4
Apr
105
13
1.3
3.0
< 0.01
0.05
0.49
0.033
15
6.2
Jun
72
3.1
0.9
2.4
< 0.01
< 0.02
0.34
0.018
19
5.3
Aug
100
2.2
2.2
5.4
< 0.01
< 0.02
0.21
0.010
22
5.1
Oct
140
1.3
2.9
3.0
< 0.01
< 0.02
0.32
<
4.8
Dec
108
4.5
2.4
0.02
0.37
0.55
<
5.3
Month
Caz+
Cl-
MgZ+
Na
SO4Z-
Alkalinity
Hardness
As
B
Cu
Feb
14
19
6.1
< 5.0
15
21
59
1.0
417
2.6
Apr
11
16
5.1
< 5.0
14
23
49
0.8
303
2.3
Jun
13
17
5.9
5.1
14
25
56
0.9
331
2.2
Aug
17
27
7.1
5.5
18
28
72
1.6
601
1.2
Oct
20
31
9.2
5.6
19
30
89
1.7
736
1.0
Dec
15
27
7.0
< 5.0
17
25
65
1.5
571
0.8
Month
Hg
Mn
Se
Tl
Feb
0.0069
108
0.9
< 0.10
Apr
0.0096
26
< 0.5
< 0.10
Jun
0.0014
50
0.5
< 0.10
Aug
0.0012
86
0.7
< 0.10
Oct
0.0008
36
0.7
< 0.10
Dec
0.0017
325
0.8
< 0.10
Duke Energy Progress 24 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Appendix 3. (continued)
Station SHHW
Month
TDS
Turbidity
Secchi
Chlorophyll a
NH3-N
NO3 + NO2 -N
TN
TP
TN:TP
TOC
depth
Feb
55
21
0.9
< 0.01
0.24
0.44
0.058
7.6
6.5
Apr
59
5.9
0.8
< 0.01
< 0.02
0.44
0.032
14
4.9
Jun
82
9.1
0.9
0.06
< 0.02
0.46
0.045
10
6.0
Aug
59
4.5
< 0.01
< 0.02
0.49
0.030
16
5.7
Oct
77
19
0.5
< 0.01
< 0.02
0.87
0.053
16
7.6
Dec
62
6.2
< 0.01
< 0.02
< 0.12
0.012
4.2
Month
Cat+
Cl-
Mg2+
Na
SO42-
Alkalinity
Hardness
As
B
Cu
Feb
5.7
4.4
2.8
< 5.0
6.9
19
26
0.3
< 50
1.8
Apr
7.1
5.0
3.5
5.5
6.4
30
32
0.3
< 50
1.2
Jun
7.8
4.8
3.8
5.5
5.2
32
35
0.7
< 50
1.4
Aug
7.9
6.2
3.6
< 5.0
5.1
29
34
0.8
76
1.1
Oct
8.4
7.8
4.0
< 5.0
6.2
26
38
0.6
124
1.5
Dec
9.0
7.8
4.2
5.8
6.2
38
40
0.3
76
< 0.5
Month
Hg
Mn
Se
Tl
Feb
0.0055
88
< 0.5
< 0.10
Apr
0.0033
56
< 0.5
< 0.10
Jun
0.0014
131
< 0.5
< 0.10
Aug
0.0015
44
< 0.5
< 0.10
Oct
0.0034
66
< 0.5
< 0.10
Dec
0.0011
58
< 0.5
< 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.
Duke Energy Progress 25 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Chloride
200
rn 175 _
E 150
0 125
100
c 75
50..............................................
c
U25 ........... ..................
0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Hardness
� 250
E 200
0 150
r
�o
y 100
c
m
50
0
U 0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
15
J
z
c 10
0
0
L
c 5
a�
0
c
0
Total Copper
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Total Dissolved Soilids
, 500
J
E 400
0 300
200
a�
c 100
0
U 0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Total Arsenic
5
J
4
03
m
L 2
c
m
�1
0
U
0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Total Selenium
5
J
03
m
L 2
C
0
c1
0
U
0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Appendix 4. Long-term trends of selected parameters at Station 2B from Hyco Reservoir from
2007 through 2016.
Duke Energy Progress 26 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Chloride
100
J
E 75
c
0
50
L
Y
u 25
c
0
U 0 Tow -- W 4 r Y# 41 4 1a
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Hardness
225
, 200
E 175
C 150
0 125
ILU 100
C 75
c 50
U 25
0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
25 Total Copper
J
Z 20
0 15
w
^c 10 _.._
W
c 5-
0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
600
J
500
C 400
0
300
L
Y
0 200
U
0 100
U 0
Total Dissolved Soilids
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Total Arsenic
5
J
4
s
o3
m
c2
0
U
01
U
0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Total Selenium
5
J
4
03
m
L 2
W
c1
0
U
0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Appendix 5. Long-term trends of selected parameters at Station 3B from Hyco Reservoir from
2007 through 2016.
Duke Energy Progress 27 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
150
J
125
C 100
0
75
L
50
0 25
U 0
Chloride
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
250
J
200
0 150
m
c
100
m
c 50
0
U 0
50
J
s 40
0 30
m
20
m
U
0 10
U
0
Hardness
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Total Copper
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
500
m
E 400
c
300
m
L
c 200
0
0 100
U 0
Total Dissolved Soilids
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Total Arsenic
5
J
m4
03
m
L 2
C
a) " N . % � %A
01
0
U
0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Total Selenium
5
J
4
s
03
:p
m
c2
0
c1
0
U
0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Appendix 6. Long-term trends of selected parameters at Station 4B from Hyco Reservoir from
2007 through 2016.
Duke Energy Progress 28 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
150
J
E 125
C: 100
0
m 75
L
0 50
0
0 25
U 0
Chloride
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
250
J
E 200
0 150
m
100
N
c 50
0
U 0
— 50
J
= 40
v
r0 30
m
20
U
0 10
U
0
Hardness
2007 2008 2009 2010 2011 2012 2012 2014 2015 2016
Year
Total Copper
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Total Dissolved Soilids
— 400
J
m
E 300
c Mr
0
200
L
r
U 100
C
0
U 0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Total Arsenic
5
J
4
z
03
m
L 2
C
N , � %..� 1� �% � :� ;�A �
c1
0
U
0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Total Selenium
5
J
4
03
m
L 2
C
01
U
0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
Appendix 7. Long-term trends of selected parameters at Station 6B from Hyco Reservoir from
2007 through 2016.
Duke Energy Progress 29 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Appendix 8. Means and standard errors of trace element concentrations in µg/g dry weight+ in
sediments and fish by transect from Hyco Reservoir during, 2016. (Values in
parentheses are the corresponding wet weight values.)"
Matrix
n
Transect
Element
Arsenic
Cadmium
Copper
Mercury
Selenium
Sediments
3
3
< 6.2 (0.8)
< 2.9 (0.4)
71 (26)b f 1.3 (0.5)
< 3.6 (1.3)
2.2 (0.8)b f 0.2 (0.07)
3
4
13 (4.7) f 1.3 (0.5)
< 2.9 (0.4)
112 Qa f 10 (3.6)
< 3.6 (1.3)
7.1 (2.6)a f 0.4 (0.1)
Fish liver
White Catfish§
6
3
< 0.2 (0.04)
< 2.0 (0.4)
9.4 (1.8) f 1.2 (0.2)
0.4 (0.08) f 0.03 (0.006)
14 (2.8) f 0.8 (0.2)
8
4
< 0.2 (0.04)
< 2.0 (0.4)
43 (8.6)t 23(4.6)
0.4 (0.08) t 0.11 (0.02)
23 (4.6)t 5.4 (1.1)
Bluegill
10
3
0.9 (0.2)b t 0.2 (0.04)
< 2.0 (0.4)
6.3 (1.3)b t 0.3 (0.06)
0.3 (0.06) t 0.06 (0.01)
13 (2.7)b t 1.2 (0.3)
10
4
5.3 (1.1)a t 0.9 (0.2)
< 2.0 (0.4)
81 (17)a t 34 (7)
0.5 (0.1) t 0.09 (0.02)
21(4.4)a t 2.0 (0.4)
Largemouth Bass
10
3
1.0 (0.2) t 0.2 (0.5)
< 2.0 (0.5)
17 (4.1)b t 4.0 (1.0)
0.5 (0.1) t 0.07 (0.02)
11 (2.6)b t 1.3(0.3)
10
4
1.6 (0.4) t 0.2 (0.5)
< 2.0 (0.4)
33 (7.9)a t 4.8 (1.2)
0.6 (0.1) t 0.11 (0.03)
18 (4.3)a t 2.6(0.6)
Fish muscle
Catfish§
6
3
< 0.2 (0.04)
< 2.0 (0.4)
0.3(0.05)t 0.04 (0.007)
0.5 (0.09) t 0.06 (0.01)
2.6 (0.5)b t 0.2 (0.04)
8
4
< 0.2 (0.04)
< 2.0 (0.4)
0.9 (0.2) t 0.2(0.04)
0.6 (0.1) t 0.07 (0.01)
10 (1.8)a t 1.4 (0.3)
Bluegill
10
3
0.2 (0.04)b t 0.1 (0.02)
< 2.0 (0.4)
4.5 (0.8)a t 0.9 (0.2)
0.4 (0.07) t 0.06 (0.01)
6.7 (1.2)b t 1.0 (0.2)
10
4
0.6 (0.1)a t 0.1 (0.02)
< 2.0 (0.4)
1.8 (0.3)b t 0.2 (0.04)
0.5 (0.09) t 0.04 (0.007)
13 (2.3)a t 0.9 (0.2)
Largemouth Bass
10
3
0.4 (0.08)b t 0.1 (0.02)
< 2.0 (0.4)
1.2 (0.2) t 0.2 (0.04)
0.8 (0.2) t 0.1 (0.02)
5.8 (1.1)b t 0.2 (0.04)
10
4
0.7 (0.1)a t 0.1 (0.02)
< 2.0 (0.4)
1.3 (0.2) t 0.3 (0.06)
1 1.1 (0.2) f 0.1 (0.02)
1 13 (2.5)a t 0.7(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: sediments0.36, White Catfish liver
0.20, Bluegill liver-0.21, and Largemouth Bass liver-0.24, White Catfish muscle-0.18,
Bluegill muscle0.18, and Largemouth Bass muscle0.19.
Standard errors and statistical analyses are given when mean concentrations were at or above the
laboratory reporting limit. Laboratory reporting limits varied between samples. Fisher's protected
least significant difference procedure was applied only if the overall F 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.
§"Catfish" included white catfish (Ameiurus catus) only.
Duke Energy Progress 30 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
25
20
3
0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
—+--Transect 3 —0—Transect 4
20
Largemouth Bass
3 15
u
C
OU 10
E
3
v
5
v
0 - -
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
—4—Transect 3 fTransect 4
15
White Catfish
ao
3
�10 ■
c
0
U
E 5
a�
v
`n 0
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
—0—Transect 3 fTransect 4
Appendix 9. Long-term trends of selenium concentrations in Bluegill, Largemouth Bass, and
White Catfish muscle tissues at Transect 3 and Transect 4 from Hyco Reservoir
from 2007 through 2016.
Duke Energy Progress 31 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Appendix 10. Total number and weight (kilograms) of fish collected with electrofishing from
Hyco Reservoir during 2016.
Scientific name+ Common name Total number Total weight (kg)
Clupeidae Herrings
Dorosoma cepedianum Gizzard Shad 292 62.8
Dorosoma petenense Threadfin Shad 452 3.2
Cyprinidae
Minnows
Cyprinella analostana
Satinfin Shiner
19
0.1
Cyprinus carpio
Common Carp
3
12.5
Catostomidae
Suckers
Erimyzon oblongus
Creek Chubsucker
1
0.1
Erimyzon sucetta
Lake Chubsucker
2
0.5
Moxostoma collapsum
Notchlip Redhorse
14
10.0
Moxostoma erythrurum
Golden Redhorse
1
0.9
Moxostoma pappillosum
V-lip Redhorse
1
0.3
Ictaluridae
Bullhead catfishes
Ameiurus catus
White Catfish
12
3.3
Ameiurus platycephalus
Flat Bullhead
4
0.5
ktalurus punctatus
Channel Catfish
32
27.7
Centrarchidae
Sunfishes
Lepomis cyanellus
Green Sunfish
41
1.0
Lepomis gulosus
Warmouth
1
0.1
Lepomis macrochirus
Bluegill
1147
23.0
Lepomis microlophus
Redear Sunfish
118
18.3
Lepomis hybrid
Hybrid Sunfish
8
0.5
Micropterus salmoides
Largemouth Bass
302
112.6
Pomoxis nigromaculatus
Black Crappie
46
6.4
Percidae
Perches
Perca flavescens
Yellow Perch
20
0.6
Morone chrysops
White Bass
6
2.5
Etheostoma collis
Carolina Darter
1
0.001
Cichlidae
Cichlids
Tilapia aurea
Blue Tilapia
3
1.1
Total`s
2,534
288.1
Total Species
20
+Taxonomic nomenclature follows Page et al. (2013).
Totals include only fish identified to species level.
Duke Energy Progress 32 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
Appendix 11. Mean catch per hour of fish collected with electrofishing by transect from Hyco
Reservoir during 2016.
Common Name
Transect
Reservoir mean
1
2
3
4
6
Gizzard Shad
21
37
30
34
23
29
Threadfin Shad
63
37
114
4
8
45
Satinfin Shiner
2
3
3
0
0
2
Creek Chubsucker
1
0
0
1
0
< 1
Lake Chubsucker
0
1
1
0
0
< 1
Notchlip Redhorse
0
2
5
0
0
1
Golden Redhorse
0
1
0
0
0
< 1
V-lip Redhorse
0
0
< 1
0
0
< 1
White Catfish
2
2
1
1
< 1
1
Flat Bullhead
1
1
0
0
0
< 1
Channel Catfish
0
8
3
3
2
3
Green Sunfish
1
0
1
11
7
4
Warmouth
0
0
0
1
0
< 1
Bluegill
217
32
85
164
69
113
Redear Sunfish
14
16
7
12
10
12
Hybrid Sunfish
0
0
0
2
2
1
Largemouth Bass
31
22
30
25
42
30
Black Crappie
17
4
2
0
0
5
Yellow Perch
3
2
5
0
0
2
White Bass
2
1
1
0
< 1
1
Blue Tilapia
0
0
0
1
< 1
< 1
Carolina Darter
0
0
0
< 1
0
< 1
Total mean+
372
168
289
259
167
251
Total number of species9�
15
17
15
11
13
25
+Totals may vary from column sums due to rounding.
Total number of species does not include hybrid sunfish.
Duke Energy Progress 33 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
15 Transect 1 (Year = 2016)
n = 432
d
10 Mean = 89
U
N
a 5
Mmmw mm
0 25 50 75 100 125 150 175 200 225 250
length (mm)
151 Transect 2 (Year = 2016)
n=65
m
10 Mean = 135
2
o_ ■
0 25 50 75 100 125 150 175 200 225 250
length (mm)
15 Transect 3 (Year = 2016)
n=181
10 ' Mean = 109
U ■
a sJ —■— ■■■■■ M
0 25 50 75 100 125 150 175 200 225 250
length (mm)
151 Transect 4 (Year = 2016)
n = 332
10 Mean = 90
IL s AMIMMIM-11111
0 25 50 75 100 125 150 175 200 225 250
length (mm)
15 Transect 6 (Year = 2016)
n=137
d
10 Mean = 115
i
a 5 �_ M1■-1
0 25 50 75 100 125 150 175 200 225 250
length (mm)
151 Transacts Combined (Year = 2016)
I n = 1147
'E 10 Mean = 98
d
U
N
a 5
0 25 50 75 100 125 150 175 200 225 250
length (mm)
Appendix 12. Length -frequency distributions of Bluegill by transect collected by electrofishing
from Hyco Reservoir during 2016.
Duke Energy Progress 34 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
15 Transect 1 (Year = 2016)
n=60
v
10 Mean = 263
v
0 50 100 150 200 250 300 350 400 450 500 550 600
length (mm)
151 Transect 2 (Year = 2016)
_ n=44
10 Mean = 304
o- 5 _ _ _ Jill
0 50 100 150 200 250 300 350 400 450 500 550 600
length (mm)
15 Transect 3 (Year = 2016)
n=62
v
10 Mean = 260
■ _ ■_ �� Q.
0 S _
0 50 100 150 200 250 300 350 400 450 500 550 600
length (mm)
151 Transect 4 (Year = 2016)
n=51
w
10 Mean = 269
IL 5 ■ ■ ■■ ■■1
0 50 100 150 200 250 300 350 400 450 500 550 600
length (mm)
151 Transect 6 (Year = 2016)
n=85
1.5 10 Mean = 265
m
Q. s ■ ■1— —
v
0 50 100 150 200 250 300 350 400 450 500 550 600
length (mm)
151 Transects Combined (Year = 2016)
I n = 302
10� Mean = 270
0 50 100 150 200 250 300 350 400 450 500 550 600
length (mm)
Appendix 13. Length -frequency distributions of Largemouth Bass by transect collected by
electrofishing from Hyco Reservoir during 2016.
Duke Energy Progress 35 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
20 Transect 1 (Year = 2016)
n=42
15 Mean = 253
2 10
a 5-
0 50 100 150 200 250 300 350 400 450 500 550
length (mm)
'dvj Transect 2 (Year = 2016)
n=73
c 15 Mean = 272
m
10 a
v
0
50
100
150
200
250 300
350 400 450
500
550
length (mm)
20
Transect 3 (Year = 2016)
n=61
c 15
m
Mean = 261
d 10
a
5-
0 1
MMMONNJI
0
50
100
150
200
250 300
350 400 450
500
550
length (mm)
20
Transect 4 (Year = 2016)
n=70
c 15
Mean = 285
2 10
d
a
5
w IN
0
0
50
100
150
200
250 300
350 400 450
500
550
length (mm)
20
Transect 6 (Year = 2016)
n=46
c 15
Mean = 306
10
m
a
5
0
0
50
100
150
200
250 300
350 400 450
500
550
length (mm)
20
Transects Combined (Year = 2016)
n=292
c 15
Mean = 275
d
10
m
a
5
0
0
50
100
150
200
250 300
350 400 450
500
550
length (mm)
Appendix 14. Length -frequency distributions of Gizzard Shad by transect collected by
electrofishing from Hyco Reservoir during 2016.
Duke Energy Progress 36 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
L 140
120
2) 100
80
c�
60
m 40
Bluegill
Mean value = 84 + 8 (SD), n = 148
75 100 125 150 175 200 225
Length (mm)
Gizzard Shad
L 140.00
Mean value = 91 + 10 (SD), n = 60
120.00
100.00 • • • • • •
80.00 • rjr�Ii •• ~ i i
CO
60.00 •
40.00 1 1 1 1 1 '
150 175 200 225 250 275 300 325 350 375
Length (mm)
Largemouth bass
140
Mean value = 87 + 9 (SD). n = 48
120
0
100
> 80
c�
am 60
lY
40
125 150 175 200 225 250 275 300 325 350 375 400 425 450
Length (mm)
Appendix 15. Relative weight values versus length for Bluegill, Gizzard Shad, and Largemouth
Bass collected by electrofishing at Transect 3 in Hyco Reservoir during 2016.
Duke Energy Progress 37 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
L 140
120
100 •• • •'
80•
60 •
CO
�
40
75 100
Bluegill
Mean value = 85 + 8 (SD), n = 141
•
•
125 150 175 200
Length (mm)
Gizzard Shad
L 140.00
Mean value = 91 + 8 (SD), n = 69
120.00
100.00
a� 60.00
ry
225
40.00
150 175 200 225 250 275 300 325 350 375
Length (mm)
Largemouth bass
L 140
Mean value = 85 + 9 (SD), n = 59
120
LM
100
> 80
c�
m 60
40
125 150 175 200 225 250 275 300 325 350 375 400 425 450
Length (mm)
Appendix 16. Relative weight values versus length for Bluegill, Gizzard Shad, and Largemouth
Bass collected by electrofishing at Transect 4 in Hyco Reservoir, during 2016.
Duke Energy Progress 38 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
400
Wflil
300
oa
= 250
y 200
co
E 150
O
ap 100
CO
J
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
Year
-4—LMB fBG Total Fish
Appendix 17. Biomass of Bluegill, Largemouth Bass, and total fish collected by electrofishing from
Hyco Reservoir, 2007-2016.
Duke Energy Progress 39 Water Resources

Roxboro Steam Electric Plant 2016 Environmental Monitoring Report
100
no
a�
m
0
00 40
20
A
0 20 40 60 80
PSD Largemouth Bass
♦--Bluegill versus Largemouth Bass
•-Gizzard Shad* versus Largemouth Bass
M
07
60
N_
0
n
40 a
9C
100
Appendix 18. Proportional Size Distribution (PSD) ranges for balanced populations of Bluegill
versus Largemouth Bass and Gizzard Shad versus Largemouth Bass collected from
Hyco Reservoir during 2016. *No "balance" range has been determined for Gizzard
Shad.
Duke Energy Progress 40 Water Resources