NC0004979_Balanced and Indigenous Population Report (316A)_20141015

Balanced and Indigenous
Population Report (316 A)
RECEIVED/DENRIDWR
OCT 15 2014
Water clue_ lfty
Permitting 30coon

ASSESSMENT OF BALANCED AND INDIGENOUS POPULATIONS
IN LAKE WYLIE NEAR ALLEN STEAM STATION
NPDES Permit No. NC0004979
Principal Investigators:
Michael A.Abney
John E.Derwort
Josh R. Quinn
RECEIVED/DENR/DWR
OCT 1 5 2014
Water wunry
PermltUng Section
DUKE ENERGY
Environmental Services
McGuire Environmental Center
13339 Hagers Ferry Road
Huntersville,NC 28078
October 2014

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RECEIVED/DENR/DWR
OCT 1 5 2014
Water Uuality
Permitting Section

ACKNOWLEDGMENTS
The authors wish to express their gratitude to a number of individuals who made significant
contributions to this report. First, we are much indebted to the Environmental Monitoring
field staff in carrying out a complex, multiple-discipline sampling effort that provides the
underpinning of this report. Glenn Long, David Horne, and Courtney Flowe contributed to
water quality sample collections. Mark Auten, Kim Baker, David Coughlan, and Bob Doby
contributed to fisheries collections and sample processing. Shannon McCorkle and Jan
Williams contributed to macroinvertebrate collections and sample processing.
We would also like to thank multiple reviewers including Jason Brown and Tom Thompson.
RECEIVEDIDENRIDWR
OCT 1 5 2014
Water Quality
Permitting Section
ii

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TABLE OF CONTENTS
ACKNOWLEDGMENTS....................................................................................ii
LISTOF TABLES ..............................................................................................vii
Chapter1 ......... ....................................................................................................1-1
STATIONBACKGROUND.................................................................................................1-1
RESERVOIR BACKGROUND...........................................................................................1-1
REGULATORY BACKGROUND......................................................................................1-2
Chapter2......... ....................................................................................................2-1
REGULATORY CONSIDERATIONS................................................................................2-1
METHODS............................................................................................................................2-1
RESULTS AND DISCUSSION...........................................................................................2-1
StationOperation............................................................................................................2-1
ThermalCompliance......................................................................................................2-2
Meteorology....................................................................................................................2-2
Chapter3......... ....................................................................................................3-1
METHODS AND MATERIALS..........................................................................................3-1
RESULTS AND DISCUSSION...........................................................................................3-1
Summer Thermal Profiles...............................................................................................3-2
SummerDO Profiles......................................................................................................3-3
CONCLUSIONS...................................................................................................................3-3
Chapter4......... ....................................................................................................4-1
MATERIALS AND METHODS..........................................................................................4-1
RESULTSAND DISCUSSION...........................................................................................4-2
Substrate and Water Quality...........................................................................................4-2
Taxa................................................................................................................................4-2
Density............................................................................................................................4-3
Major Taxonomic Groups..............................................................................................4-3
CONCLUSIONS...................................................................................................................4-5
Chapter5......... ....................................................................................................5-1
iii

MATERIALS
AND METHODS..........................................................................................5-1
Spring Electrofishing Surveys._-------------.--.----.---_----.5-1
Summer Electrofishing Surveys-----.-----.--.------_.----.—.--.--5-2
Fall Purse Seine Surveys—.-------.-------_—.-------.---..--.--5-2
Balanced and Indigenous Assessment............................................................................5-2
RESULTSAND DISCUSSION...........................................................................................5-3
Sozizo Electrofishing Surveys---.—.'--..—..-------.—.---.----_—..—.--'5-3
Fall Purse Seine Surveys_.----.--.—.----..-----_.--.-'-----.--.--'5-5
CONCLUSIONS__--.'--.'--.--.---_.--_.—_-------.—.---------'5-5
LITERATURE CITED
..^^^^^~............................~..`............~~`~................'`'..`^`^^' I
APPENDIX
APPENDIX A SPRING SEDIMENT AND HEXAGENIA SAMPLING IN

EXECUTIVE SUMMARY
Annual monitoring of physicochemical characteristics and assessments of macroinvertebrates
and fish populations at selected locations in Lake Wylie continued through 2013, in
accordance with Duke Energy's agreement with the North Carolina Department of
Environment and Natural Resources. This report presents data collected from 2009 through
2013. The objective of this ongoing monitoring program is to assess macroinvertebrate and
fish populations with respect to operation of Allen Steam Station (AS) and support renewal
of existing thermal limits in the AS National Pollutant Discharge Elimination System
(NPDES)permit(NC0004979).
During 2009 — 2013, AS operated less frequently than previous baseload periods. The AS
generating facility produced electricity 75% of available days January 2009 — December
2013 compared to 99.2% of the available days during 2004 — 2008. The average monthly
condenser cooling water(CCW) discharge water temperature ranged from a minimal 16.7°C
(62 °F) in February 2009 to a maximum equal to the upper permitted limit, 38.9 °C (102 °F),
in June 2010, July 2010, August 2010, July 2011, and July 2012. Discharge temperatures
followed a regular seasonal pattern and were typical of previously reported CCW discharge
data for this facility. The thermal limits of the NPDES permit for AS were not exceeded
during the 2009—2013 monitoring period.
In-situ thermal and dissolved oxygen (DO) profiles were obtained in the vicinity of AS to
evaluate potential water quality influences from operation of the CCW system at AS.
Thermal profiles at three Lake Wylie locations sampled from surface to bottom indicated
temperatures were generally representative of seasonal conditions seen in recent years. Lake
Wylie DO profile concentrations were slightly higher than recent 2004 — 2008 historical
trends and indicated adequate concentrations of DO were present during mid-summer of each
year from 2009 to 2013 for the continued propagation of balanced and indigenous biological
populations in Lake Wylie in the vicinity of AS.
Generally, the macroinvertebrate data from 2009 to 2013 exhibited similar densities and taxa
abundance as seen during previous report periods. Spatial variations in taxa abundance at the
three monitoring locations were consistent with historical data and showed no impairment
related to the AS thermal effluent. The current study results indicate that, overall, the
macroinvertebrate densities and taxa diversity observed during 2009 — 2013 at locations
v

uplake, downlake, and in the vicinity of AS are indicative of balanced and indigenous
macroinvertebrate communities.
A diverse fish community was present in the littoral surveys of Lake Wylie near AS from
2009 to 2013. Spring and summer electrofishing surveys documented 35 and 18 species,
respectively, both numerically dominated by centrarchids, especially bluegill. Pollution-
tolerant species comprised less of the spring AS fish population relative to the reference area,
and comprised only 6.7%of individuals collected during summer surveys. The assorted fish
species typically found in Lake Wylie near AS encompass multiple trophic guilds (i.e.,
insectivores, omnivores, and piscivores) supporting a balanced fish community. Non-
indigenous species such as green sunfish are abundant near AS, but are also prevalent
throughout Lake Wylie.
Purse seine surveys from fall 2009 to 2013 indicate that threadfm shad continue to dominate
the Lake Wylie forage fish community. Alewife percent contribution has remained relatively
low since 2005 and was < 2.0% from 2009 to 2013. Based on the catch per unit effort of
littoral fish during spring, total length distributions of resident important species during
summer, and the regular availability of forage fish, it is concluded that the thermal discharge
of AS has not impaired the Lake Wylie fish community.
Ultimately, the collective information presented in this report indicates a balanced and
indigenous aquatic population exists in the vicinity of AS. Water quality data reported by
other researchers, as well as 2009 — 2013 Duke Energy results associated with AS CCW
operation, serve to confirm that Lake Wylie in the vicinity of AS, and as a whole, is capable
of sustaining a balanced and indigenous aquatic community. Additionally, comparison of AS
operation to environmental monitoring data indicates that balanced and indigenous
populations of macroinvertebrates and fish continue to exist in Lake Wylie near AS. These
data support a conclusion that the present thermal limits are appropriately protective and
should be maintained when the Station NPDES permit is renewed.
vi

LIST OF TABLES
Table Title Page
Table 4-1. General descriptions of the substrate found at Locations A, B, and C in the
vicinity of AS from July 2009 to 2013. Substrates are listed with the most
prevalent type first. Organic matter is typically composed of small sticks, leaf
and/or grass fragments etc. ..............................................................................4-7
Table 4-2. DO and temperature measured at the time of macroinvertebrate collection from
Locations A,B,and C from July 2009 to 2013...............................................4-7
Table 4-3. Macroinvertebrate taxa and densities (No./M2) from Location A(uplake of AS)
during summer sampling from 2004 to 2013...................................................4-8
Table 4-4. Macroinvertebrate taxa and densities (No./M2) from Location B (AS discharge)
during summer sampling from 2004 to 2013.................................................4-10
Table 4-5. Macroinvertebrate taxa and densities (No./m2) from Location C (below AS)
during summer sampling from 2004 to 2013.................................................4-12
Table 5-1. Total number of individuals, percent composition, and number of species in
spring electrofishing surveys from two areas (AS and REF) in Lake Wylie,
1993 — 1997 and 1999,2000—2003,2004—2008,and 2009—2013.............5-7
Table 5-2. Total number of individuals, percent composition, and number of species in
summer electrofishing surveys from three areas (above, in, and below the
discharge canal) near AS in Lake Wylie, 1991 — 1993, 1994 — 1999, 2000 —
2003,2004—2008,and 2009—2013...............................................................5-8
Table 5-3. Pelagic forage fish species composition from purse seine surveys in Lake
Wylie, 1994—2013..........................................................................................5-9
vii

LIST OF FIGURES
Figure Title Page
Figure 1-1. Lake Wylie map with AS and other Duke Energy stations.............................1-4
Figure 2-1. Average monthly AS CCW discharge temperatures displayed over days per
month of generation during 2009—2013.........................................................2-4
Figure 2-2. Total daily flow from AS CCW pumps during 2009—2013...........................2-4
Figure 2-3 AS CCW daily average summer intake temperatures for 2009—2013 compared
to intake temperatures during the summer of 2007. ........................................2-5
Figure 24. Monthly average air temperatures calculated from data at a nearby Catawba
Nuclear Station meteorological tower. ............................................................2-6
Figure 2-5. Annual total rainfall from a nearby Catawba Nuclear Station meteorological
tower. ...............................................................................................................2-6
Figure 2-6. Lake Wylie daily lake levels and drawdown 2009—2013..............................2-7
Figure 3-1. Water quality sampling locations on Lake Wylie in the vicinity of AS..........3-5
Figure 3-2. Comparison of August 2009 — 2013 Lake Wylie thermal and DO vertical
profiles with historical August data.................................................................3-6
Figure 4-1. Macroinvertebrate sampling locations in the vicinity of AS.........................4-15
Figure 4-2. Total number of taxa collected annually at Locations A, B, and C from Lake
Wylie near AS from 2004 to 2013.................................................................4-16
4-17
Figure 4-3. Mean densities (No./m2) of macroinvertebrates collected annually at Locations
A,B,and C from Lake Wylie near AS from 2004 to 2013.......................4-17
Figure 4-4. Densities (No./m2) of Corbicula, Chironomidae and Oligochaeta collected
annually at Location A from 2004 to 2013....................................................4-18
Figure 4-5. Densities (No./m2) of Corbicula, Chironomidae, and Oligochaeta collected
annually at Location B from 2004 to 2013....................................................4-18
Figure 4-6. Densities (No./m2) of Corbicula, Chironomidae, and Oligochaeta collected
annually at Location C from 2004 to 2013....................................................4-19
Figure 4-7. Densities (No./m2) of Hexagenia collected annually at all locations during the
summer periods of 2004 to 2013. ..................................................................4-19
Figure 4-8. Densities (No./m2) of Hexagenia collected annually at all locations during the
spring periods of 2010 to 2013......................................................................4-20
Figure 5-1. Locations associated with spring and summer electrofishing surveys, and fall
purse surveys of Lake Wylie. ........................................................................5-10
viii

LIST OF FIGURES
Figures Title Page
Figure 5-2. Total number of fish collected in spring electrofishing surveys from two areas
(AS and REF) in Lake Wylie, 1993 — 1997 and 1999—2013.......................5-11
Figure 5-3. Biomass of fish collected in spring electrofishing surveys from two areas (AS
and REF)in Lake Wylie, 1993 — 1997 and 1999—2013. .............................5-11
Figure 54. Total number of fish species collected in spring electrofishing surveys from
two areas(AS and REF) in Lake Wylie, 1993— 1997 and 1999—2013.......5-12
Figure 5-5. Length distribution of bluegill among survey locations in summer
electrofishing surveys near AS in Lake Wylie,2009—2013. .......................5-12
Figure 5-6. Length distribution of redbreast sunfish among survey locations in summer
electrofishing surveys near AS in Lake Wylie,2009—2013. .......................5-13
Figure 5-7. Length distribution of largemouth bass among survey locations in summer
electrofishing surveys near AS in Lake Wylie,2009—2013. .......................5-13
ix

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CHAPTER 1
INTRODUCTION
STATION BACKGROUND
Allen Steam Station (AS) is located on Lake Wylie (Figure 1-1) in Gaston County, North
Carolina, southwest of Charlotte. The station is comprised of five fossil-fired steam
generating units having a combined nameplate capacity of 1,145 MWE-gross. Units 1 and 2
are currently rated at 165 MW and began commercial operation in 1957. Units 3, 4, and 5
are currently rated at 265 MW, 280 MW, and 270 MW, and began commercial operation in
1959, 1960,and 1961,respectively.
The intake structure for once-through condenser cooling water (CCW) is located on the
Catawba River arm of Lake Wylie. The CCW system discharges heated effluent into the
South Fork Catawba River arm of Lake Wylie via a 1.2-km-long discharge canal. Each
steam generating unit has two conventional CCW pumps that can be operated independently.
Station operators run either one or two pumps per unit as dictated by intake water
temperature, discharge temperature limits, and operational efficiency. The maximum
pumping capacity of the 10 CCW pumps is 34.38 m3/s (1,214 cfs). The AS discharge
temperature is continuously monitored, and operations are modified as needed to ensure
compliance with permitted thermal limits.
In the previous permit cycle (2004 — 2008), Duke Energy operated a supplemental cooling
system to assist in meeting discharge temperature limits following an exceptionally dry
meteorological year in 2007. Operation of a supplemental cooling system was not utilized
during the 2009—2013 time period.
RESERVOIR BACKGROUND
Lake Wylie typically exhibits weak summer thermal stratification, due to the relatively
1-1

lacustrine nature of much of the reservoir, coupled with the routine withdrawal of mid-depth
water via Wylie Hydroelectric Station(VMS). At the South Fork River arm confluence with
the main channel (Figure 1-1), a mid-summer top to bottom thermal gradient ranging from
about 2.5 to 8.0 °C occurs, depending principally on AS generation, the temporal-spatial
dynamics of the station thermal discharge plume, as well as reservoir hydroelectric inflows
and outflows. The water quality standard minimum for dissolved oxygen, 4.0 mg/L
measured instantaneously, has historically been exceeded near the surface of the reservoir
throughout the year, including within the AS thermal plume (Duke Power Company 1976;
Duke Power 2004b; Buetow 2008).
Historical water quality assessments characterized Lake Wylie as a mesotrophic to eutrophic
waterbody (Weiss and Kuenzler 1976; NCDEHNR 1994). Fluctuations in trophic
classifications were attributed to temporal variations in meteorological conditions, closely
linked to hydroelectric generation and watershed inputs. Inflows from the relatively
expansive basin have led to spatial patterns of varying water quality within the reservoir. For
example, water quality in the upper Catawba River arm of Lake Wylie has typically been
characterized by lower concentrations of dissolved and suspended constituents, including
nutrients, than the South Fork Catawba River arm of the reservoir. Exceedances of
applicable water quality standards and action levels for chlorophyll a, major nutrients (i.e.,
total phosphorus, total organic nitrogen, and nitrate-nitrite nitrogen), and fecal coliform
bacteria have been observed among various tributary arms receiving inflow from nutrient-
impaired streams — most notably Dutchman's Creek, the South Fork Catawba River arm,
Withers cove,and Crowder's Creek(NCDENR 2008; Buetow 2008).
REGULATORY BACKGROUND
The AS station has historically operated, and continues to operate, under a 316(a) thermal
discharge variance associated with the Clean Water Act(CWA). Assessment of the potential
influence of thermal discharges on biological communities is a key component of thermal
discharge variances granted under section 316(a) of the CWA. As defined in
40CFR 125.7 1(c), "The term balanced, indigenous populations...refers to a biotic community
typically characterized by diversity, the capacity to sustain itself through cyclic seasonal
changes, presence of necessary food chain species and a lack of domination by pollution
1-2

tolerant species. Such a community may include historically non-native species introduced
in connection with a program of wildlife management and species whose presence or
abundance results from substantial, irreversible environmental modifications"(1972).
In pursuance of a 316(a) variance, Duke Power Company developed an initial 316(a)
"demonstration" document in 1976 that was submitted to NCDENR. The "demonstration"
summarized the state of station operations, water chemistry, and aquatic biology of Lake
Wylie in the vicinity of AS during previous AS operational years. The goal of the document
was to demonstrate the maintenance of "balanced and indigenous populations" under the
baseload AS station operational scheme at that time.
The initial 316(a) demonstration was considered adequate by NCDENR to show protection
of"balanced and indigenous" biological populations. The thermal discharge from AS was
permitted under the 316(a) National Pollutant Discharge Elimination System (NPDES)
provisions of the CWA,as authorized by the NCDENR.
Subsequently, Pursuant to an agreement with the NCDENR, annual monitoring of
macroinvertebrates and fish was implemented in 1990 at selected Lake Wylie locations in the
vicinity of AS. The objective of this ongoing monitoring program was to assess
macroinvertebrate and fish populations with respect to continued operation of AS, and
provide an indication of the suitability of approved thermal limits as defined in the AS
NPDES permit. Individual chapters of this report contain methods and location maps
associated with fisheries, macroinvertebrates, and water quality portions of this on-going
monitoring program.
Previous summaries of monitoring in Lake Wylie have established that the existing AS CCW
thermal limits incorporating the variance granted under the CWA section 316(a) has assured
the protection and propagation of balanced, indigenous populations in Lake Wylie (Duke
Power Company 1994; Duke Power 2001a, 2004b; Duke Energy 2009b). This report
presents results related to AS operations from data collected since submittal of the previous
(2009) summary report and includes data collected from 2009—2013. Also, the 2009—2013
data are discussed with other environmental monitoring programs conducted in this
watershed.
1-3

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1-4

CHAPTER 2
STATION OPERATION
REGULATORY CONSIDERATIONS
Current National Pollutant Discharge Elimination System (NPDES) (NCDENR 2011a)
permitted thermal limits for Allen Steam Station (AS) condenser cooling water (CCW)
effluent,based upon an approved 316(a)thermal variance,are:
• a monthly average CCW discharge (i.e., end-of-pipe) temperature limit of 35 `C (95 '')
during October I through May 31, and
• a monthly average CCW discharge temperature limit of 38.9 `C (102 ') during June I
through September 31.
METHODS
The AS discharge water temperatures were continuously monitored during 2009 — 2013 to
assess thermal permit compliance. Thermal compliance data were obtained from NPDES
discharge monitoring reports. Additional detailed(hourly) CCW thermal and flow data were
from the Duke Energy Plant Information (PI) System. Meteorological data was retrieved
from the Duke Energy Air Vision database as recorded at a nearby meteorological tower at
Catawba Nuclear Station.
RESULTS AND DISCUSSION
Station Operation
Unlike previous years of continual baseload operation, AS was operated less frequently
during 2009—2013. One of the five units was in operation on 1,372 of 1,826 available days
2-1

over the 2009 — 2013 time period (75% of available days) compared to the previous 5-year
operation period(2004—2008) where at least one of the five coal-fired units was generating
on 99%of the available days(Figure 2-1; Duke Energy 2009b).
Thermal Compliance
The CCW discharge flows generally fluctuate seasonally,with AS electrical output,and were
managed such that CCW discharge temperatures were maintained at or below NPDES
thermal limits during 2009 — 2013 (Figures 2-1 and 2-2). The average monthly CCW
discharge water temperature ranged from a minimal 16.7 °C (62 °F) in February 2009, to a
maximum equal to the upper permitted limit, 38.9 °C (102 °F), in June 2010, July 2010,
August 2010, July 2011, and July 2012 (Figure 2-1). Discharge temperatures followed a
regular seasonal pattern and were typical of previously reported CCW discharge data for this
facility(Duke Power Company 1976, 1994; Duke Power 2001 a,2004b,2009b).
From the standpoint of cooling water resources and thermal compliance margins, the
summers of 2010 and 2011 proved to be the most challenging summers during the 2009 —
2013 monitoring period, as indicated by elevated summer intake and discharge temperatures,
as well as CCW pump flows(Figures 2-1 through 2-3 ).
Comparison of mid-summer 2010 and 2011 CCW daily intake temperatures with 2007
summer intake temperatures (the summer of 2007 was the most challenging thermal
compliance period for the previous 5-year monitoring period) revealed that 2010 and 2011
daily intake temperatures were among the warmest, and often were warmer than 2007 intake
temperatures (Figure 2-3). CCW intake temperatures in 2010 and 2011 reached a maximum
daily average of 32.9 °C (July 26, 2010) and 32.5 °C (July 25, 2011), compared to the hot
drought year of 2007,when intake temperatures reached 32.3 °C on August 10.
Meteorolo¢y
It is important to discuss meteorologically noteworthy years during the 2009 — 2013 period
because of the overarching climatological and hydrological effects on station operations (and
ultimately, lake temperature patterns). Meteorological and hydrological conditions
substantially affect reservoir-wide physicochemical conditions. Rainfall totals affect the
amount of water available for generation/releases, and ultimately, affect the balance of water
2-2

maintained in the reservoir at any given time. The amount of water in the reservoir is
particularly important to the dissipation and distribution of heat from the thermal loads to the
reservoir.
During the 2009 — 2013 study period, several meteorologically extreme years were noted.
Multiple years experienced air temperatures on a monthly timescale that were repeatedly
above historical monthly means. In particular, monthly average air temperatures near AS in
the late spring/summer of 2010 and 2011 were among the highest monthly average
temperatures on record, for that site. Also, 2012 was considered the warmest year on record
for the contiguous United States (National Climatic Data Center 2013) mainly due to an
extremely warm winter/spring; however, division of water quality investigators indicated
July of 2013 was also the third warmest July on record for the state of North Carolina since
1859 (NCDENR 2013). Conversely, monthly average air temperatures near AS in the
spring/summer of 2013 were among the lowest monthly average temperatures at the nearby
Catawba Nuclear Station site(Figure 2-4).
Annual and spring/summer monthly rainfall totals, specifically in 2010 and 2012, were
relatively low in comparison to summer months in other years during the 2009—2013 study
period. Additionally, annual total rainfall for these years was among the lowest rainfall totals
over the 1986 — 2013 period (Figure 2-5). Conversely, annual rainfall totals in 2009, 2011
and 2013 were near or above average for the 1986 —2012 period with summer month (June
and July)precipitation in 2013 being well above average.
Lake levels varied seasonally and episodically over the 2009 — 2013 period based on
expected rainfall patterns, in response to actual rainfall totals within the watershed, and in
response to electrical demand(Figure 2-6).
2-3

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month of generation during 2009—2013.
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2-4

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2-6

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Figure 2-6. Lake Wylie daily lake levels and drawdown 2009—2013.
2-7

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CHAPTER 3
WATER QUALITY MONITORING
METHODS AND MATERIALS
To evaluate operation of the Allen Steam Station (AS) condenser cooling water (CCW)
system, vertical profiles of temperature and dissolved oxygen (DO) were collected in the
winter and summer at three conventional water quality sampling locations in Lake Wylie
(Locations 235, 242, and 250; Figure 3-1) that correspond closely with summer
electrofishing transects (Figure 4-1) and macroinvertebrate sampling locations (Figure 5-1).
Sample locations provided coverage (as ordered above) ranging from the furthest
downstream site near the confluence of South Fork and mainstem Catawba Rivers to the
furthest upstream site at the AS CCW intake. At each location, thermal and DO vertical
profiles were collected in situ with a calibrated Hydrolab DataSonde®at near-surface(0.3 m)
and 1-m depth increments, to within 0.5 m of bottom. Analyses were performed by Duke
Energy Scientific Services personnel.' Graphical techniques were used to assess selected
summer vertical profile data. Additionally, references to data and summaries from other
investigators are made,where appropriate.
RESULTS AND DISCUSSION
In recent years, the North Carolina Division of Water Quality (NCDWQ), Mecklenburg
County Department of Environmental Protection, and Duke Energy (NCDENR 2013;
Buetow 2013; Duke Energy 2013) researchers have continued to characterize Lake Wylie as
mesotrophic/eutrophic. Nutrient inputs from the South Fork Catawba River and other
tributaries in the sub-basin, coupled with development in the watershed, continue to
1 The Duke Energy Scientific Services organization is presently certified by the North Carolina Division of
Water Quality(DWQ)under the Field Parameter Certification program(certificate number 5193). However,all
field chemistry data represented in this report are uncertified data; i.e., not collected for effluent compliance
monitoring purposes.
3-1

contribute to elevated nutrient concentrations in Lake Wylie compared to Mountain Island
Lake, immediately upstream on the Catawba River. The nutrients supplied to the reservoir
continue to provide abundant foundation for primary and secondary production in the
reservoir.
Summer Thermal Profiles
Thermal profiles at all three sampling locations from the 2009—2013 period were indicative
of the historical Lake Wylie summer thermal patterns reported previously (Duke Power
Company 1976; Duke Energy 2009b). The mixed (near isothermal) temperature pattern at
the reference location(Location 250) was typical of the riverine nature of Lake Wylie at this
location. The near-field location (Location 242) exhibited temperature patterns of a typical
thermal plume with warmer, less dense, water near the surface and cooler, more dense water
at lower depths. Additionally, the far-field location (Location 235) exhibited the weak
stratification pattern typically apparent in the more lacustrine portions of the reservoir. This
weak stratification pattern continued to be driven in the 2009 — 2013 period, largely by the
AS-heated discharge, climatic conditions, and mid-depth water withdrawals by Wylie
Hydroelectric Station (WHS), as reported previously (Duke Energy 2009b). As expected,
variability in water temperature within the typical temperature pattern was observed at all
locations among the summers of 2009 — 2013 (Figure 3-2) and was closely connected to
variability in meteorology.
Thermal profiles from the mid-summers of 2009 — 2013 at all three lake water quality
sampling locations reflected trends in air temperatures and CCW intake temperatures for
those years(see Chapter 2). Like the 2010 summer air temperatures and intake temperatures,
summer water temperatures at the three lake locations were elevated, and in some cases,
greater than previously measured temperatures(mainly in the middle depths of the reservoir).
Mid-depth temperatures in 2012 were also slightly elevated compared to historical data;
however, temperatures in the upper portion of the water column at the discharge location
(242) remained below historical maximum temperatures for all summer monitoring events
from 2009—2013.
Elevated summer lake profile temperatures were common in other reservoirs in the Catawba
River Basin, as well as other North Carolina watershed reservoirs in 2010 (Duke Energy
2011b; NCDENR 2011b). Elevated water temperatures statewide were noted as being
3-2

heavily influenced by meteorological conditions; namely, air temperatures that were
persistently above average in the spring to late summer of 2010 (NCDENR 2011b).
Mid-depth summer water temperatures at location 235 were also slightly elevated compared
to historic temperatures despite water temperatures at the discharge location (242) being
within historical ranges (Figure 3-2). As indicated in Chapter 2, air temperatures in late July
2012 were exceedingly above average, as were air temperatures in the preceding
winter/spring of 2012. Lake temperatures in August of 2012 were likely influenced by these
elevated air temperatures, as evidenced by temperature profiles at the background location
(250) relative to profiles from other years during 2009—2013. Summer intake temperatures
(Figure 2-3) for 2012 were also at maximum levels at the time of lake sampling (August 1)
for 2012 and were consistent with temperatures from the background Lake Wylie location
(250).
Summer DO Profiles
The 2009—2013 summer dissolved oxygen(DO)profile data exhibited a vertical distribution
pattern similar to the historically observed Lake Wylie DO distribution(Figure 3-2). As with
temperature profiles, the summer DO profiles exhibited characteristics of both a riverine and
lacustrine water body depending upon the monitoring location, meteorological conditions,
and water movement in and out of the reservoir. Profile DO values were mostly within the
range of previously recorded values, with no measured DO values being less than the
historical 1998 — 2008 minimums. Additionally, measured profile DO values during the
2009 — 2013 period indicated Lake Wylie exhibited well-oxygenated waters in the upper
portion of the water column, adequate for fish survival, every summer in the vicinity of AS
(see Chapter 5).
CONCLUSIONS
Lake Wylie water quality has, in recent years, been fairly consistent with previous
assessments. In somewhat of a contrast to the two Catawba River reservoirs immediately
upstream (Lake Norman and Mountain Island Lake), Lake Wylie has an expansive sub-
catchment, resulting in significant inflows to the reservoir from a number of nutrient-
enriched tributaries. This factor can contribute to an increased element of spatial and
3-3

temporal water quality variability within Lake Wylie, compared to other upstream reservoirs.
It also leads to an abundant supply of nutrients for primary and secondary productivity in the
reservoir (see Chapter 4 and 5). The reservoir as a whole continues to be classified as a
eutrophic/mesotrophic waterbody.
Despite meteorologically challenging years in 2010, 2011, and 2012, the effects of AS
operational thermal load on the temperature and DO in Lake Wylie during 2009 — 2013
appeared to be similar to previous years when biological communities have been sustained.
Although some mid-depth temperatures were slightly above historical values, all
temperatures in the upper portion of the reservoir were below historical maximums.
Ultimately, water quality monitoring conducted by Duke Energy Environmental Services
Personnel, and water quality data reported by other researchers during 2009— 2013, indicate
that Lake Wylie in the vicinity of AS, and as a whole, continues to exhibit water quality
conditions fairly consistent with historical observations. These conditions have been, and
should continue to be, conducive to sustaining a balanced and indigenous aquatic biological
community.
3-4

4� �\�'` MounulNt blind Darn
US-29,74
S SR1
Allan
Steam
1 sudon 2�
LOS WIN `��r� 242
4sen
235
C�n11 410l/TH CdI1g1H,� ••�.
F SC 387
i
aa►r"" J l�Cmawba Nucha► r�
Motion N
J/ r'
CO
v j IIVgIle Dam
�luorn��n �' „I •( r
0 oat 2 i 4 f.
►ra
0 0.3 1 2 7
Figure 3-1. Water quality sampling locations on Lake Wylie in the vicinity of AS.
3-5

TS-WffdM rq tee•M
20 22 24 26 29 D 32 34 36 38 40 43 20 22 24 26 28 30 32 34 36 39 40 42
0 0
1 1
I 1
..... :, 2
I
• -_
I
Location 2S0 location 242
14 14
tallo oom rq DbMk6a OaYlaO lar/q
20 22 24 26 b 30 32 34 36 38 40 42 0 1 2 3 4 5 6 7 a 9 10
a o
1 1
/ 1
I
I f
1
4 1 4
1 1
10 — 10
12 12
London 235 Location 250
14 14
Dbw v e OwApn lwgN 0144o196d p 3a60Imt/U
0 1 2 3 4 5 6 7 4 9 10 0 1 2 3 4 5 6 7 a 9 10
0 0
2
- 1
1
E 4 _ 6 /
10 10
_m _m
12 12
Location 242 Location 235
14 1 1 14
Figure 3-2. Comparison of August 2009 — 2013 Lake Wylie thermal and DO vertical
profiles with historical August data.
3-6

CHAPTER 4
MACROINVERTEBRATES
MATERIALS AND METHODS
Benthic macroinvertebrate sampling was conducted annually in late July (Table 4-1) each
year from 2009 to 2013,as part of the continued monitoring program for Allen Steam Station
(AS). As in previous years, samples were collected from three locations in Lake Wylie:
Location A, a reference site uplake of AS; Location B, a near-field site in the mouth of the
AS discharge canal; and Location C, a far-field site downlake of AS at the confluence of the
South Fork Catawba River and the Catawba River(Figure 4-1). A petite Ponar dredge was
used to collect five sample replicates at each location. Samples were collected at depths
ranging from 2 m to 3 m to bracket the depth of peak benthic abundance Brinkhurst 1974 .
g g ep P ( )
Samples were washed through a 500-µm mesh sieve and individually preserved with 70%
ethanol containing rose bengal stain. The substrate of each replicate was identified,based on
a visual analysis of substrate types during the sieving process, and the resulting data were
recorded. Organisms were sorted in the laboratory and identified to the lowest practicable
taxon. Beginning in 2001, Oligochaeta, which were only identified to taxonomic order in
previous study years, were identified to genus and species. Macroinvertebrate densities were
expressed in numbers/m2 bottom area. The assessment of the balanced and indigenous nature
of the benthic community was determined by comparing macroinvertebrate densities and
taxa abundance among the three sample locations.
At the request of the North Carolina Department of Environment and Natural Resources
(NCDENR) (letter dated January 13, 2010), Duke Energy personnel initiated specific
sampling for Hexagenia. Sampling began in the spring (April) of 2010 and has been
conducted annually each spring through 2013. In addition to Hexagenia sampling, an
analytical assessment of substrates at Lake Wylie locations was conducted in 2010. Methods
and results for both Hexagenia and sediment sampling are presented in Appendix A.
4-1

Beginning in 2005, in conjunction with macroinvertebrate sampling, a pre-calibrated YSI
Model 55 handheld dissolved oxygen (DO) meter was used to measure water temperature
and DO just above the sediment at each location. Starting in 2008, water temperatures and
DO values were measured in situ,using a pre-calibrated Hach®HQ40d water quality meter.
RESULTS AND DISCUSSION
Substrate and Water Quality
Upon visual assessment, substrates typically consisted of varying proportions of silt, sand,
and organic matter. Locations A and B had primarily silt-dominated substrates, with lesser
amounts of organic matter and sand (Table 4-1). Location C substrates were variously
dominated by all three types during successive years of sampling. Substrate composition at
Lake Wylie locations, based on visual assessments, has essentially been the same since
sampling was initiated (Duke Power 2004; Duke Energy 2009c). At the request of
NCDENR, an analytical assessment of substrates at Lake Wylie locations was undertaken.
Results indicated that substrate from Location A consisted of fine sand particles with a large
proportion of silt and very fine sand (Appendix A). At Locations B and C, the bulk of
sediments consisted of material ranging from fine to coarser sand and smaller amounts of silt.
The DO concentrations were generally highest at Location A, with minimum values most
often recorded from Location C. Maximum temperatures consistently occurred at Location
B near the AS discharge, with minimum temperatures observed most often at Location A,
upstream of AS (Table 4-2).
Taxa
The number of different macroinvertebrate taxa collected at a location is often an indicator of
the overall diversity of a community and can signify the presence of a balanced indigenous
population. Taxa numbers during 2009 — 2013 varied temporally and spatially (numbers
ranged from 12 to 32)and total taxa numbers were somewhat higher during 2009—2013 than
during 2004 — 2008 (Tables 4-3 through 4-5 and Figure 4-2). Numbers at all locations
appeared to show a decline from 2009 through 2011, and then an increase through 2013.
Maximum taxa numbers most often occur-red at Location A, with minima most often
4-2

recorded from Location B near the discharge.
Density
During 2009 — 2013, overall mean macroinvertebrate densities, expressed as numbers/m2,
varied substantially among years and locations. High spatial and temporal variability are
characteristic of macroinvertebrate communities in North Carolina piedmont reservoirs
(Duke Energy 2009a, 2009b, 2009c, 201 la). The difference between minimum and
maximum densities during 2009 — 2013 ranged up to over 20 times. Total densities were
within historical ranges and averaged about the same as those of 2004 — 2008 (Figure 4-3).
Densities at Location A showed an overall decline from 2009 through 2013, while densities
at Location B showed a decline from 2009 through 2012, and then a sharp increase in 2013.
Densities at Location C showed the opposite trend with increasing values through 2012,
followed by a decline in 2013 (Tables 4-3 through 4-5 and Figure 4-3). Spatially, maximum
densities were most often observed at Location C (2010 through 2012), while Location B
demonstrated maxima in 2009 and 2013. Minimum densities were recorded from Location A
in 2012 and 2013,Location B in 2011 and 2012,and Location C in 2009(Figure 4-3).
Considering the visual determinations of substrate composition among the three locations
(Table 4-1), as well as results of the analyses performed in 2010 (Appendix A), the observed
spatial differences in total density may not be specifically attributed to substrate habitat.
Nutrient availability may be responsible for much of the observed variability. The South
Fork Catawba River, a tributary characteristically known for nutrient levels higher than those
of the Catawba River arm (see Chapter 3), may provide nutrient enrichment and resulting
higher productivity at Location C, at the confluence of the South Fork arm and the Catawba
River. Variability observed at Location B may have been due to comparatively high
temperatures at the mouth of the discharge(Table 4-2).
Major Taxonomic Groups
Considerable variability was observed among major taxonomic groups, particularly the
Oligochaeta, Chironomidae, and Corbicula. Oligochaetes were represented by 15 taxa
among Lake Wylie locations during 2009—2013. Oligochaeta densities during 2009—2013
ranged over two orders of magnitude from minimum to maximum (Tables 4-3 through 4-5
and Figures 4-4 through 4-6). Oligochaetes were dominant in Lake Wylie macroinvertebrate
4-3

samples approximately two-thirds of the time and comprised the major portions of
populations at Locations B and C and were typically observed to have the highest densities at
Location C. At all locations, the majority of oligochaetes were tubificids. Milligan (1997)
stated that Tubificidae frequently form dense populations in organically enriched habitats
with a silty or muddy substrates tending toward anoxic conditions. The sediment types at
Locations B and C (Table 4-1, Appendix A), as well as the organic enrichment characteristic
of the South Fork Catawba River, contributed to increased oligochaeta populations at
Locations B and C as opposed to Location A. At Location A, oligochaeta densities showed a
sharp increase in 2010, followed by an equally dramatic decline in 2011. Densities then
increased though 2012 and declined slightly in 2013 (Figure 4-4). At Location B,
oligochaeta densities declined from 2009 through 2012, and then increased sharply in 2013
(Figure 4-5). At Location C, oligochaeta densities demonstrated an overall increase from
2009 through 2012, and then decreased by 75% in 2013 (Figure 4-6). These trends tended to
spatially mirror the temporal trends observed among total densities(Figure 4-3).
Chironomidae are among the most ubiquitous and wide-spread families of aquatic
macroinvertebrates, and are found in a wide variety of habitats. Chironomids were
represented by between 20 and 27 taxa and were dominant in approximately one-third of the
samples collected during 2009—2013 (Tables 4-3 through 4-5 and Figures 4-4 through 4-6).
Densities of chironomids ranged up to nearly 30 times from minimum to maximum during
2009 — 2013. Chironomids were generally more abundant at Lake Wylie locations during
2009 — 2013 than during the previous five-year period. They were typically the most
abundant macroinvertebrates observed at Location A and often demonstrated high densities
at Location C (Table 4-3 and Figure 4-4). At Location A, chironomids demonstrated a
marked decline from 2009 through 2012, and then increased slightly during 2013 (Figure 4-
4). Chironomid densities at Location B increased from 2009 to 2010, and then declined
through 2011 (Figure 4-5). Densities increased through 2012, followed by a dramatic
increase to the five-year peak at Location B in 2013. At Location C, chironomid densities
showed an overall increase from 2009 through 2012, and then declined by 60% from 2012
through 2013 (Figure 4-6).
No consistent patterns of temporal abundance of Corbicula at Lake Wylie locations were
apparent due to extreme variability. Corbicula densities ranged nearly 70 times from
minimum to maximum during 2009 — 2013. Location C most often demonstrated higher
densities than other locations (Tables 4-3 through 4-5 and Figures 4-4 through 4-6). At
4-4

Location A, overall abundance during 2009 — 2013 was higher than during 2004 — 2008
(Table 4-3 and Figure 4-4). At Location A, Corbicula showed an overall increase from 2009
through 2011, followed by a decline in 2012 and a slight increase in 2013. At Location B,
Corbicula densities were extremely low throughout 2009—2013 and an overall increase was
observed between 2009 and 2013 (Table 4-4 and Figure 4-5). Corbicula densities at
Location C showed a dramatic increase from 2009 to 2010, and then gradually declined
through 2013 (Table 4-5 and Figure 4-6).
Summer populations of Hexagenia showed considerable variability and densities during 2009
—2013 and were considerably higher than those of 2004—2008 (Tables 4-3 through 4-5 and
Figure 4-7). The highest summer densities of Hexagenia were typically observed at Location
A, although during 2010 a high density was recorded from Location B. The presence and
abundance of mayflies were irregular Locations B and C.Hexagenia typically prefer the finer
sediments, cooler temperatures, and higher DOs observed at Location A (Tables 4-1 and 4-4,
Appendix A). Summer Hexagenia densities at Location A peaked in 2011, and then declined
through 2013. During spring periods of 2010—2013, Hexagenia were never collected from
Location C and small numbers were collected from Location B in 2010 and 2012 (Figure 4-
8). Spring Hexagenia densities peaked at Location A in 2011, while similar numbers were
collected at this location in 2010, 2012, and 2013. Based on sediment analyses during 2010
and temperature and DO data (Appendix A and Table 4-2), conditions at Location A
appeared to be more suitable for Hexagenia than at Locations B and C.
CONCLUSIONS
The observed variability in Lake Wylie macroinvertebrate density and taxa numbers is
indicative of the general variability of reservoir macroinvertebrate data. This variability is an
important consideration when comparing density data among years and locations and
assessing community changes relative to natural variability and potential operational impacts.
The data for the current study generally exhibited somewhat higher taxa numbers and similar
densities as reported during the previous period. Taxa numbers at most locations tended to
decline from 2009 through 2011, and then increase through 2013. Consistent spatial trends
of taxa numbers and total densities were difficult to discern; however, maximum taxa
numbers and densities were most often recorded from Locations A and C, respectively, while
4-5

minimum taxa numbers were most often recorded from Location B. No consistent spatial
trends of minimum densities were observed.
Oligochaetes and chironomids were the most abundant forms observed at Lake Wylie
locations, with oligochaetes being most abundant at Location C, while chironomids were
dominant at Location A. The vast majority of oligochaetes were tubificids. The sediment
types at Locations B and C, as well as the possible higher organic enrichment in the South
Fork and adjacent confluence area as compared to the reference location, would likely
facilitate increased oligochaete populations at these locations. Temporal trends among
oligochaetes and chironomids varied from location to location, while spatial trends varied
from year to year. Corbicula densities were typically highest at Location C and no consistent
temporal trends among Corbicula were observed during 2009—2013.
Hexagenia densities during summer periods of 2009 — 2013 were much higher than those
recorded in the previous five-year period and mayflies were generally most abundant at
Location A. Hexagenia were also most abundant at Location A during spring Hexagenia
sampling since 2010. High abundances of Hexagenia at Location A were likely due to a
combination of sediment types and water quality conditions.
Previous and current study results indicated that the macroinvertebrate densities and taxa
diversity observed during 2009 — 2013 at locations uplake, downlake and in the vicinity of
AS are indicative of balanced and indigenous macroinvertebrate communities. Thermal
effluents from AS have not impaired macroinvertebrate communities in Lake Wylie.
RECEIVED/DENR/DWR
OCT 15 2014
Water wality
Permitting Secdon
4-6

f
Table 4-1. General descriptions of the substrate found at Locations A, B,and C in the
vicinity of AS from July 2009 to 2013. Substrates are listed with the most
prevalent type first. Organic matter is typically composed of small sticks,leaf
and/or grass fragments etc.
Year Location A Location B Location C
silt silt silt
2009 organic matter organic matter organic matter
sand sand
silt silt sand
2010 organic matter sand silt
organic matter organic matter
silt sand organic matter
2011 organic matter silt silt
sand organic matter sand
silt silt silt
2012 sand sand organic matter
organic matter organic matter sand
silt silt organic matter
2013 sand sand silt
sand
Table 4-2. DO and temperature measured at the time of macroinvertebrate collection from
Locations A, B,and C from July 2009 to 2013.
Year Location A Location B Location C
2009 7.16 mg/L 7.01 mg/L 6.17 mg/L
27.0°C 29.1 °C 28.5°C
2010 7.26 mg/L 6.6 mg/L 5.95 mg/L
31.4°C 37.2°C 32.7°C
2011 7.40 mg/L 7.22 mg/L 7.24 mg/L
30.2°C 34.7°C 30.1 °C
2012 7.30 mg/L 7.00 mg/L 6.28 mg/L
30.4°C 34.0'C 31.5°C
2013 6.37 mg/L 6.74 mg/L 7.65 mg/L
27.5°C 32.4°C 30.8°C
4-7

Table 4-3. Macroinvertebrate taxa and densities (No./m2) from Location A (uplake of AS)
during summer sampling from 2004 to 2013.
Taxa 2004 2005 ZW6 M 2006 2009 2010 2011 2012 2013
Diptera
CentoppnWn
9 34 17 9 26
Chnoboridae
Chaobcm app, 9 387 52 172 9 9 34 17
Am=app, 9 9 663 241 164 396 17
Chirownus app. 60 52 52 69 17 17
Cladopebm app. 121 17
Cladobgbrsus app. 26 362 387 34 112 34
Qyptod*on nus spp. 26 26 43 34 26 9 17 60 9
34 413 9 17
Uidobsndespneomodestus 52 181 17 9 17 69
app- 9 112
Herraadra app. 17 52 26
A ovddronmw app, 17 69 17 26 26 9
Pageabaft app- 9 26 9
flMM 17
hdbrale gr 9 52 26 34 207 9
Pokpodhim sM%wwm gr 9
Psembdaivown app. 9 172 34
Sternpalb►a app. 9
9 52 26 9
cefhanius 138 26 43 9
Tanyfarsus am 9 43 9 9 267 77 17 69
Crkokws Pago 9 250
AbMbmnChironomidae-T
Y►a app- 9
Abbbesmyia wm&ta T7 26 34 52 26 138 224 129 198
Abbbwmyiajanta 9
AbWbwmyiemWocN 34 9 9 26
Ablebesm ' ffimpie qr 17 9 43
_C4Qbw"w app- 60 60 17 26 69 9 52 86 17 129
Prodedws aFp. 112 207 60 34 138 43 9 69 112
Caeoidse
Csenia app. 17
EVwmwidae
Haxagwia app- 77 34 17 17 17 482 336 844 430 52
ro
SiWidae
Siahs app. 9 52 34 69 26 77
Mollusca
Corbiculidae
C fbicuta fluminea 121 9 34 34 52 43 189 69 95
Spha rww
Sphaerirrm 34
4-8

Table 4-3. (Continued)
Taxa 2004 2005 2006 2007 2001 2009 2010 2011 2012 1013
01
Naiddoe 9 17 17
Adsonais lomondi 181
34
Dero app. 1 1 43 1 17 9
Dere dodata 43 26
Dere hWida 34
Nais commmis 9 17
Plisum situs 9
Stylaria tacushis 9
Tubtwjdae 1 9 52 422 9 1 17 95
Aukxhlus limnobius 34 215
Au/o"us pigtmfi 112 852 1 835 1.059 9 172
&andwua sowerbyi 146 250 181 9 43 17 1 77 52 172 86
Tubftx lubifex 26
Others
Glossiphorwdae
Gkkbdw7a ebmjaia 103 77 69
Nlalabdel/a 26 9 69
Habbdaga stagndis 396
SabOklae
Meme unkia speciosa 26 26 17 9 60
Nematoda 17 1 17 60 95 77 26 34 34 121
Trkhoptern
am m kpsy n 26
Hydq-Hy&Wffla app-tffdas
9
Leptoceridae
Oomft app. 9
PolycerftpoMm
Polymn6vpus app. 9
Total Density for Yeer 732 1,803 938 1,404 2.171 3.257 3,444 1 Z0941 1.659 1,785
Total Taxa forYear 15 28 16 18 1 17 1 31 1 32 1 20 1 27 22
4-9

Table 4-4. Macroinvertebrate taxa and densities(No./m2) from Location B (AS discharge)
during summer sampling from 2004 to 2013.
Taxa 2004 2005 29M 2007 2000 200! 2010 2011 2012 2013
i8 9 26 9 43 26 26 9 60
Chaoboidae
Cheabonis app. 1 9 34 775 499 611 69 9 1 52
Axarus app. 17 95
Chrormmw app. 9 17 17 26
Gadapebma app- 34
Gadofanytarsus spp. 26
spp. 26 1 69 9 86 34 43 1 34 1 34
86 69
neomodsshm 9 9 17 9
tfarniadvia app. 34 9 17
Moodiiumt, SPP- 34 17 26 43 9 112
9 9
helterale gr 26 126 17 17 26 198 52 60 9
us
app- 17
spp. 9 26
caffradus gr. 17
Tan 9 17 9 1 9 1 103 1 749
Chiron
Crkotopus ihm 17
Chi OWTn T
annufala 146 9 9
AbWwwyia ' to 9
CyawwYPUS app. 344 138 34 413 456 284 52 52 551
Prodadbs app. 17 77 52 1 474 52 52 103 310
EpImmwoptem
Caenidae
Caenis app. 9
Ephen idae
Hawgenia 26 818 9 60
MegaknAern
Siaidae
Sialic spp. 9 9
Mollusca
Corbkmfidae
Carbicula flumina 121 4.873 9 9 17 17 9 60
Odonaw-Anhwnftra
GomoWw
D"mKqwnphus spp. 17
Nigochaeta
Nakhdae 9 9 1 1 9
Allanais pechwta 69
BratislaWa unidentata 9 43
Dem spp. 34
4-10

Table 4-4. (Continued)
Taxa 2004 2005 2806 2007 2x08 2009 2010 2011 2012 2013
OfigodweW
Dwo ckdata 17
Dery obtmw 241
Dery trifida 17
Nais app. 9
Nais aamnis 138
Naffs variabds 17 878
Ptis6ne/la osbami 34 258
Tubicidae 34 17 34 103 396 9 34
Aubodnks 5mnabius 1 17 1 103 26
Aulodn7us pigu 706 1 189 95 887 9,0231 723 181 1 95 1,696
Aub**n pkmiseta 43 11,124 17
Brwwh;nm sambyi 9 34 60 77 1,188 T7 T7 1,068
TubAw tub w 9 9
Others
GW.siownidae
Robbdmffa app. T7
Habbdela sfWmNs 9 9
SabeMse
Afanayunfoa speck= 9 9 95
Nematoda 9 43 26 474 456 26 672
Trkhopbara
Leptocmkhm
Oeaeft SM. 9 9 17
Total Dens4 for Year 1,353 5,691 3% 2,342 15,U1110,297 3,557 922 561 5,761
Total Taxa for Year 12 21 14 12 1 18 1 14 28 12 14 25
4-11

Table 4-5. Macroinvertebrate taxa and densities (No./m2) from Location C (below AS)
during summer sampling from 2004 to 2013.
Taxa 2®04 2005 2006 2907 2000 2009 2910 2011 2012 2013
Coleoptera
Hy*opffdae
Hydabius spp. 9
Diptera
Ceratopogonidae
Palpamyia-B is camplex 9 17 9 9
Chaoboridae
Chaobonrs spp. 26 138 43 17 26 52 17
Chkormnidae-Chkonoffirm
Axwm app. 34 34
Ghimnomus app. 1 43 52 146 34 1 34 1 9
(*btanytarsus app. 9 26 9 34 17 17 9 9
Cryptod�ivoramus app- 146 26 95 232 52 69 9 17
Cryptotendow app. 9 26 17 17
M olem�Vpes neomodeatira 26 112 9 232 17 129 95 172
Glyph�lh MVpes app. 293 60 164 1,929 121 1.171 620
Hamisdiia app. 17 9
114ciochiroreorrnra SAP- 43 26 17 9
Pagashella app. 9
Parad* nomus app_ 9
Pbfypedl7um app. 9
Pdypedkm flavum 9
Pralypedgum haN&We gr 129 1 60 465 52 715 T7 267 9 34
PdypeMum scobwJ rm gr 9
app. 9 9
tfiadus 9r. 17
Tanytarsus spp. 17 26 577 267 17 370 336 430 129
CfkOtWM app. 26
Chaetodadius app. 138
CWrowmidae-TWYPDdinW
Abbbesmyia annulate 1 17 1 52 103 9
Ablabesrnyiajto 9 60 284
Ablabeamyis mallochi 52 129 1 1 17 9
AbWmm ' rhamphe gr 155 86 284 86
Coebtanypus 319 646 129 1,464 103 112 396 585 620 155
Pmckw ius SAA. 60 215 1 60 405 250 26 86 69 430 77
Ephemeroptera
Baetidae
Pasudodoeon app. 17
CaeFWW
Caenis app. 17 26 9 69 17 60 86 9 34
Ephenwklae
Hexagenia spp. 17 1 52 1 1 60 336 17
Leptohyphidae
Trkmythodes spp- 9
4-12

Table 4-5. (Continued)
Taxa 299 2M 2006 2007 2008 2009 2911 2111 2012 2013
Mollusca
Corbi mbdae
C vbkula f umkw 1,076 276 250 156 1,240 26 620 560 310 136
a
Naicww 9 69 69 9 17
Ak neis 2,824
Brafisfavia unidanfata 9 17 26 26
Dara app. 34 34 121 26
Dern obfusa 2.549
Dern hwwa 86
Haemmi frs wamyga 17
Nail cwnmtnis 9
Naffs pardahs 9
Nais variabiis 9 69
Pristina b mune 9
Prisum lorgrsoma 86
Ptis6na sone 482
pm-Am syncfifes 207
PdsfieeAa jenldnae 86 9
P►is5ne0a osborni 17 155
9
lawsbis 9
Tubdc:idae 827 60 585 542 2,764 585 1,774 1,713 3,521 749
A*K ilus knFX US 26 52 95 9 4,718 129 77 172 362 146
Aubdgus pomfi 17 17 69 34 878 9 344 86 95 112
Aub*An pkvim6 86
Bofhrianecrrxn Y%movskyanum 69
Bmndrkm wowtyi 146 86 95 86
Li nrxx f m hof r isterei 9 1 172 405 439 52
TubhxfubAw 17 456 52 336
Others
Glossiownedae
1,507 1,412 448
Helobdefla app. 34 26 1,343 129 310 362
Helobdells stagnalis 146 9 9 680 103
Rwwidae
9
SabelCcdae
Manayunloa spomm 629
Nematoda 17 34 129 930 276 34 2,884 809
Trichoptera
Dipseudopsidae
s app- 9
HydropsyctWn
Chwmakpayche spp. 9
HydroKkdae
Hy W la spp- 9
Leptoceddae
Akckpsydie spp- 9
4-13

Table 4-5. (Continued)
Taxa 2904 2005 2096 2607 2008 2009 2616 2011 2012 2013
Trichoptera
leptocwkbe
peoetis 34 77 17 103 17 9 17
Crrwow"ham 26 9 1 1 17 52 1 155
pofycmbq rs app. 1 17
Total Density for Year 3,324 1.936 2,64E5,167 22,026 2,152 5,063 6.141 12,605 4.142
Total Taxe for Year 24 27 1 26 29 36 1 26 1 20 23 25 30
4-14

1_, • +urn 1111�Dam
U
1,
f
Alm
IMM
_ slhtloe
_ 1
o.eMc4.,p wwma,ouw,`1 �; I i
`"•tea .ourpW,q� ,..� _-____ �,
_l
I �
ro►�"' "Nud�u �+
>�bn Ltd N
Wylie Dam
�KbnrYn i
0 as 1 2 7 ♦ r i, ,
Mln
0 a0 1 1 f ♦
Figure 4-1. Macroinvertebrate sampling locations in the vicinity of AS.
4-15

40 ----------------
35 ------------- ---------
30 -
-o
m 25 - --- -- _
U
m
O
U
20 - - - -
I—
ia
15
I—
10 - - ---- --- - - - - -- ---. --- --
5
5 0 AIB C -
B C A,B C_ A B . A B G A B G 13 A@ A B C A B G.
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Figure 4-2. Total number of taxa collected annually at Locations A, B, and C from Lake Wylie near AS from 2004 to 2013.
4-16

7,000
LQ N
6,000
5,000 -
E
0
Z 4,000 _ - -
Cn
0 3,000 - --- ----------
76
H
2,000 --- -- -
1,000
A,B C A B C A B C A B C A B C A B C A.B C A B C A B C A B C
0 �_ _.._ _ . - --�-
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Figure 4-3. Mean densities (No./m2)of macroinvertebrates collected annually at Locations A, B, and C from
Lake Wylie near AS from 2004 to 2013.
4-17

LocationA
3,000
z WO -----
Z.aoo --- -- — —-- ------.. .
1.Wo — —
11000 -- -- - - -
Goo -
0 -
2004 2005 2006 2007 2D06 2009 2010 2011 2012 2013
m Corbicu% s Chimnarrmidse ■Oiiyochaeta
Figure 4-4. Densities (No./m2) of Corbicula, Chironomidae and Oligochaeta collected
annually at Location A from 2004 to 2013.
Location B
3A0 —
2.600 -
2,aoo —
A
1.600 - ---- ------—..--- —......
1.000 —
Goo - -- - -- - - .-
0
2004 2005 2008 2007 2D08 2009 2010 2011 2012 2013
mCoibkuW sChironornidse aCRpoohsets
Figure 4-5. Densities (No./m2) of Corbicula, Chironomidae, and Oligochaeta collected
annually at Location B from 2004 to 2013.
4-18

Location C
3.000 - -------------------- -- -
2500 — ----- - --
2000
x.1,500 --------------------- —__ - ----•-------- -
1.000 —- --- _. ..— -- ----- --
am - - -
O
2004 2DO5 2D06 20W 2006 2000 2D10 2011 2012 2013
.Cofbkw■ a cN anomift ■0fipodw■ ft
Figure 4-6. Densities(No./m2)of Corbicula,Chironomidae, and Oligochaeta collected
annually at Location C from 2004 to 2013.
Hexagonin
1,000 --- ---- - . --- - - --- - -- ---- -,.__
900 - _ --- - - - - - _ ..-— -- --- --- -- -- - -.
---------
700
1
000
400 _.-
900
100 --_.--
0 ■ ■ J1 C •�■
As C ■ C ■ C ■ C ML
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Figure 4-7. Densities(No./m2)of Hexagenia collected annually at all locations during the
summer periods of 2004 to 2013.
4-19

f
moogenb
900
am -—- - --
7100
S00
300
200 F 100 c a c c
0
2010 2011 2012 2013
Yemrs-sprtew aamwes
Figure 4-8. Densities(No./m2)of Hexagenia collected annually at all locations during the
spring periods of 2010 to 2013.
4-20

CHAPTER 5
FISH
MATERIALS AND METHODS
Spring Electrofishing Surveys
Annual (2009 — 2013; current NPDES permit cycle) boat electrofishing surveys were
continued in Lake Wylie in March or April at two areas: in the South Fork Catawba River
near the thermal influence of Allen Steam Station (AS; Figure 5-1) and at a reference area
(REF) in the Catawba River located between AS and Catawba Nuclear Station. Ten 300-m
shoreline transects were surveyed in each area and were identical to historical locations
surveyed since 1993. Transects included littoral habitats representative of those found in
Lake Wylie. All sampling was conducted when surface water temperatures were expected to
be 15—20 °C.
Stunned fish were collected by two netters and identified to species. Fish were enumerated
and weighed in aggregate by taxon, except for spotted bass (Micropterus punctulatus) and
largemouth bass (M. salmoides), where total length (TL, mm) and weight (g) were obtained
for each individual collected. Surface water temperature(°C)was measured with a calibrated
thermistor at each transect. Annual catch per unit effort (CPUE per 100 m) was determined
by area for number of individuals,biomass,and number of species collected. Condition(Wr)
based on relative weight was calculated for spotted bass and largemouth bass> 150 mm TL,
using the formula Wr = (W/Ws) x 100, where W = weight of the individual fish and Ws =
length-specific mean weight for a fish as predicted by a weight-length equation for each
species (Neumann et al. 2012). Resulting metrics were compared between areas using a t-
test(P<0.05).
5-1

Summer Electrofishing Surveys
Annual (2009 — 2013) boat electrofishing surveys were continued in Lake Wylie in July or
August near the thermal influence of AS. Six 100-m shoreline transects were surveyed to
represent three areas (Figure 5-1): two transects above the AS intake canal (A), two in the
discharge canal (B), and two below the discharge canal (C). Transects were identical to
historical locations surveyed since 1991 and independent of spring transects. Surface water
temperature and dissolved oxygen (DO, mg/L) were measured with a calibrated thermistor
and DO probe, respectively, at each location. Stunned fish were collected by two netters,
identified to species,and measured for TL. Representative and Important Species(RIS)were
selected based upon abundance, distribution, and ecological significance as a prey (bluegill
[Lepomis macrochirus] and redbreast sunfish [L. auritus]) or predator (largemouth bass)
species.
Fall Purse Seine Surveys
Species composition and size distribution of pelagic forage fish in the Lake Wylie epilimnion
were determined annually in mid-September. Purse seine sample techniques were used at
midlake(Figure 5-1; near Crowders Creek) and downlake(near Wylie Hydroelectric Station)
areas in water deep enough for unhindered net deployment (Hayes et al. 2012). The purse
seine measured 122.0 x 9.1 m, with a mesh size of 4.8 mm. A subsample of forage fish
collected from each area was used to estimate taxa composition and TL size distribution.
Balanced and Indigenous Assessment
Annual surveys are used to assess the balanced and indigenous nature of the Lake Wylie fish
community and provide information relative to the potential thermal influence of AS. The
assessment includes comparisons of spring electrofishing CPUE (spatially and temporally)
and of summer electrofishing RIS length distributions. Results from both seasonal surveys
were examined according to species pollution tolerance and trophic guild. Purse seine
surveys of pelagic forage fish were examined for trends.
5-2

RESULTS AND DISCUSSION
Spring Electrofishing Survey
Spring electrofishing surveys from 2009 to 2013 were conducted at average water
temperatures ranging from 18.0 to 22.5 °C. Surveys resulted in the collection of 24,703
individuals comprising 34 species at the AS area and 20,592 individuals comprising 26
species at the REF area(Table 5-1). The number of individuals per 100 in ranged from 139.7
to 197.6 at the AS area and from 96.5 to 192.1 at the REF area (Table 5-1 and Figure 5-2).
Fish biomass per 100 in ranged from 9.7 to 16.0 kg at the AS area and from 8.0 to 14.3kg at
the REF area(Figure 5-3). The number of species per 100 in ranged from 17 to 25 at the AS
area and from 16 to 22 at the REF area(Figure 5-4). Since 1993, the number of individuals,
biomass, and number of species collected from the AS area were significantly greater than
those from the REF area. When limited to the current permit cycle (2009 — 2013), only the
biomass collected from the AS area was significantly greater than from the REF area. The
number of species from the AS area was either equal to 2009 or greater than 2010—2013
values from the REF area,although not statistically significant(t-test; P=0.06).
The number of individuals in spring electrofishing surveys from 2009 to 2013 was dominated
by centrarchids (AS-79.9%, REF-90.3%; Table 5-1), followed by clupeids (AS-14.5%, REF-
6.6%), cyprinids (AS-3.0%, REF-2.0%), and ictalurids (AS-1.4%, REF-0.9%). Spotted bass
were collected for the first time during spring electrofishing surveys (REF in 2010, AS in
2011). Green sunfish (Lepomis cyanellus) exhibited a considerable (and similar) increase in
relative abundance at both areas compared to the 2004—2008 study period. Overall, current
species composition data are similar to previously reported spring electrofishing data near AS
(Duke Power 2001 a, 2004b; Duke Power Company 1994; Duke Energy 2009b) and from
other Catawba River reservoirs (Duke Power 1999, 2001b, 2004a, 2004c; Duke Energy
2009a,2009c).
Species considered pollution tolerant for wadeable stream assessments (e.g., longnose gar
[Lepisosteus osseus], goldfish [Carassius auratus], common carp [Cyprinus carpio], golden
shiner [Notemigonus crysoleucas], white catfish [Ameiurus catus], redbreast sunfish, green
sunfish, and hybrid sunfish; NCDENR 2013b) represented 5.9% of AS and 12.9% of REF
individuals during spring 2009 — 2013. This percent representation was an increase from
5-3

spring 2004 - 2008 (AS-4.0%, REF-5.6%) and spring 2000 - 2003 (AS-4.1%, REF-6.2%)
due to an increased abundance of redbreast and green sunfish.
Species considered insectivorous for wadeable stream assessments (NCDENR 2013)
represented 74.1% of AS and 83.7% of REF from 2009 to 2013. Species considered
piscivorous (AS-8.4%, REF-8.3%) and omnivorous (AS-17.4%, REF-8.0%) also reflected
similar guild contributions when comparing areas from 2009 to 2013. Largemouth bass from
AS (91.6)had a higher mean Wr than from REF(89.6),although not statistically significant.
Summer Electrofishin Surveys
Summer electrofishing surveys from 2009 to 2013 resulted in the collection of 3,352
individuals comprising six families, 18 species, and one hybrid centrarchid combination
(Table 5-2). The species composition for the combined summer electrofishing surveys was
dominated by centrarchids (94.7%) followed by clupeids (3.5%). The remaining families
represented less than 1.0% of individuals each. Previously reported summer data also
documented dominance by centrarchids during summer 2004 - 2008 (89.1%) and 2000 -
2003 (74.0%). Spotted bass were collected for the first time during summer electrofishing
surveys in 2013 from the area above the AS intake canal. Overall,current CPUE and species
composition data are similar to previously reported summer electrofishing data near AS
(Duke Power 2001a, 2004b; Duke Power Company 1994; Duke Energy 2009b) and from
other Catawba River reservoirs (Duke Power 1999, 2001b, 2004a, 2004c; Duke Energy
2009a,2009c).
Pollution-tolerant species represented 6.7% of the collected fish during summer 2009-2013
surveys, similar to summer 2004 - 2008 (6.7%) and summer 2000 - 2003 (7.4%).
Insectivorous (90.7%), piscivorous (5.0%), and omnivorous (4.3%) species from 2009 to
2013 surveys had guild contributions similar to summer 2004 - 2008 (84.8%, 7.5%, 7.7%),
respectively. Summer 2000 - 2003 had a similar representation of piscivores (4.4%),
although fewer bluegill and more threadfm shad contributed to lower insectivore(75.0%)and
higher omnivore(20.6%)representation,respectively.
The TL distributions of RIS (i.e., bluegill, redbreast sunfish, and spotted bass) during
summer 2009 - 2013 surveys (Figures 5-5 to 5-7) indicated successful reproduction and
multiple age groups from above, in the vicinity of, and below the AS discharge canal.
5-4

However, the area in the discharge canal maintained considerably lower numbers of fish
during the summer likely due to the localized impact of the AS thermal discharge(as high as
41.6 °C; annual DO was 6.4 mg/L or higher).
Fall Purse Seine Surveys
Threadfin shad (Dorosoma petenense) continued to dominate annual purse seine surveys of
the Lake Wylie forage fish community from 2009 to 2013, comprising 97.9— 100.0%of fish
collected (Table 5-3). Alewife (Alosa pseudoharengus), first detected in low numbers in
Lake Wylie in 2001, have comprised as much as 10.6% (2004) of mid-September pelagic
forage fish surveys, but percent contribution has remained relatively low since 2005 and was
<2.0% from 2009 to 2013.
CONCLUSIONS
A diverse fish community was present in the littoral surveys of Lake Wylie near AS from
2009 to 2013. Spring and summer electrofishing documented 35 and 22 species,
respectively, both numerically dominated by centrarchids, especially bluegill. Pollution-
tolerant species comprised less of the spring AS fish population (5.9%) relative to the REF
area(12.9%),and comprised only 6.7%of individuals collected during summer surveys. The
assorted fish species typically found in Lake Wylie near AS encompass multiple trophic
guilds (i.e., insectivores, omnivores, and piscivores) supporting a balanced fish community.
Non-indigenous species such as green sunfish are abundant near AS, but are also prevalent
throughout Lake Wylie.
Purse seine surveys from 2009 to 2013 indicate that threadfin shad continue to dominate the
Lake Wylie forage fish community. Alewife percent contribution has remained relatively low
since 2005 and was<2.0%from 2009 to 2013.
Past studies have indicated that a balanced indigenous fish community exists near AS (Duke
Power 2001 a, 2004b; Duke Power Company 1994; Duke Energy 2009b). The present study
adds more years of comparable data, reinforcing that conclusion. Based on the CPUE of
littoral fish during spring,TL distributions of RIS during summer,and the regular availability
5-5

,l
C
of forage fuk it is c ouchxW that the thermal disc wp of AS ho'not impaired the Lake
Wylie fish comnw pity.
F
1;4
1 1A.
ew
1
.J•
1111
y��y�ppffI
ice-!
1 {
l
IA+.
i
1
- 1
5-6
r
I�i
- - --__

Table 5-1. Total number of individuals,percent composition, and number of species in spring electrofishing surveys from two
areas(AS and REF)in Lake Wylie, 1993- 1997 and 1999,2000-2003,2004-2008, and 2009-2013.
.616M16M•,NIAM O.6MMM•M0 awken01-2666 6.1MMM-sou
M w M w M f6 M w
lolniMo nna C- M. % Na. % ND. % N0. % Ik. % N0. % N. % w %
L.6M..MMw
t pk•.r11.a...w 1A.Ma.•o< 2 CAM 1 0.00% 2 0,01% 0 0100% 2 0101%
CMp•M.
AN•t p•Ntla6.ray. A6..6• 1 0.00% 10 0.01%
Doo. ..Pftlww Qk-d.w 072 6.46% 1,260 10.70% &M 2V% 46D 2A6% 2001.01% 217 1.10% 002 2.46% = IM%
Omaarp.Yraw. 11...dib.6.0 OW 6.66% 2 0,02% 2.166 0.M% 621 2.97% 1.727 17.72% Of 600% 2.71. 10.00% 1AM IAM
Cwftw00
Cw..Wn.uNw OaMN6 1 0.00%
cftnq*.M0 tY.6� Nt
O ...ry 1 0.00% 1 0.00%
L)wg MYaOW f00aM0Y1~ 1 MGM16 0.12% 6 0.02% 00 0.60% 20 0.10% 226 1.00% 2 0.01% 00 0.20%
CpM.pN- %6Yk.6a 27 0.22% 167 1.26% 107 0.77% 290 1.00% 267 1.46% 620 2.60% 221 1.21% 217 1m%
CWHWA M& Gl.aaa 126 0.6% 23 0.20% 67 0.21% 6 0.06% 126 0.02% 6 OA0% 122 0.00% 60.02%
Cffld •"tpla %d 1 0.00%
C...NM r.Yw x Cwol wpb Oddith aaa0a W'6 10.0%
Ny6ayrMM 1.0. E t .k-y6 1 0.01% 10 0.06% 17 0.16% 1 0.00% 20 0.10%
NmaY.Itpw p� 1 CAM
NW-OP.M a0•all- Od6a.6- 42 0.26% 2 OAM 9 CAM 1 0.02% 167 0.60% 11 0.06% 2M 1.01% 6 0.02%
Na wk 6.*p Al. Bpo11t1.hkw 2 0.01% 6 0.02% 20 0.00% 2 0.01% M 0.40%
mom*r 6•. kd hl Nr 6 0.01% 1 0.00%
Ne6pb.Pwp 9�4b..M- 1 0.00%
460 100 R0.1MN 7MMtl.6.1w 1 CAM 1 0101% 1 0100%
er..l.aMr
C-*-"-w- CoM.rM 2 CAM 6 0.01% 1 0.02% 1 0101%00% 2 0 0.0%01 % 12 0.00%
C�bw.a�atoi 1644 rr`r 2 0.02% 1 01 0101% z 0/ 0101%
646,01,-bko� 6 0.02%
k6o6..6W/w O..i1o1/101d41a 2 CAM
Maab6 oa6pan tklClpn.lvN 2 OM% 6 Q02%
MaMYM wwWpMt6a Ba61W MMM• 1 OAD% 6 0,02% 2 0,01%
Yaa10�p 601.4 M�i�a i 1 OA1%
ldalaYa
Atn6.r Mt�wM 6a16M�d 1 OAO%
A.M-0..Y. %6.010.6 17N 0.104 007 7.02% 001 460% MO 22M 16 aM% 100 OIM M CAM 107 0.62%
A.aYta..bw a B•.r•YiM.O 1 CAM 1 0.00% 1 OAO% 1 0.00%
A.1.A-pY00./6.6N Fl.16M100! 1 OAt% 2 0.01% 1 CAM
111.6.r YI.•Y. 6001./46 2 010%
0%
2t1t6.rptslt6M OwWe.6M .7 01 20 0,21% 210 1A0% 46 0%07Otl I.M% 27 0.10% 2001.20% M 0.41%
p1b6aM MCMI. li6rtl 0161.11 6 0.02%
MMYa
Q.a6aY 6.6rm61 !Yr.lo Ptl 1 0.01% 1 0.00% 1 0.01% M 0.07% 2 OAI% 2 CAM
11...1116•.
MssM00al.w 1166.6..016 21 0.11% 111 OAO% 1 DAD% 230 0.20% 6 0.02%
MsaMa.1•tp 106.66.. 26 0.10% 1 0.03% 12 OM% 1 0.00%
Yvs raft. 66.66,,• 1 0.00%
D..ra.6Mr
LIp.•1Y rIfM Ntb-tM.N11 200 277% NO 2.00% 101 O.U% 610 246% 200 0.00% 002 2A1% 161 0.01% 1,006 7.31%
Lpa0.a1...1n A•�1.aM 7 OAt% M 0.06% AD 0.07% 007 1.TM 620 2.20% ON 1.72%
L.p016.1r66a... R�6tlN.•d 227 2.01% M 0.61% 210 1.00% N 0126% iN 0.66% N CAM N7 1.61% 10 OA0%
/pad.016o.a. 14.160100 100 0.97% 267 2.12% 246 1.11% 2A 2.16% M 1.11% 76 2.26% 146 CAM 282 CIAM
a6t
1p61YM 1040 YMM16 27 DIM M 00% 21D 0.14% 12 0,07% M 0.22% 26 0.12% 'a016% N 071%
e wvr66r
LwBAN 50.10% 0.126 46.06% 16.200 70.46% 12.016 7112% 10.826 NAM 10.200 72 06
.06% 167 82.00% 1.467 0626%
0pad..'d.dgY Nt/ar•..661 M 0,6016 212 2.46% 684 2.00% 211 177% w dM% 501 270% 07120% Nt 2.12%
460grwt..NttYM 1p6Y66a. / OM% 1 0.00%
Yvprr rrtlW. 1+6..0100 e.0.
2.347 u.00% 2AN "M% 1.1111 6.46% 1.002 6.22% 1.62 6.02% IMB 6.M% 1.029 0.10% 1.621 771%
hu-p r111614 RAMOY C- / CAM
P..."rrbY %6t• 1 0.01%
Pte. 011rkutey. 271 1.00% 150 0122% 146 0.60% 146 CM71 176 0.67% M CAM 262 1.02% 144 0.70%
p.1•IM
SttrMtr 6�f0.r er•tOeMY 1 0.00%
9t•tlttM aYM6tl irt.YY06MM Y 0.02% 1 0A/% 11 aM% M 010% 1 CAM
br
Ifta.ow YMr aNI to 0.77% Nt 2.60% 21 0.11% 1N OA6% 2 0.01% 06 0.16% 33
.16% 0 CAM 70 0.11%
T•IM 1460 1M.M% IA666 1M.M% 21.116 IMM% 17A0 1MM% 247v "Un n1m M�M% 247M MM% 21.6M 160%
TMM O...p•dr M 21 b 82 M b M M
5-7

Table 5-2. Total number of individuals, percent composition, and number of species in summer electrofishing surveys from three
areas(above, in, and below the discharge canal)near AS in Lake Wylie, 1991 - 1993, 1994- 1999, 2000-2003,2004
-2008, and 2009-2013.
Sumer 1991-1993' sumer 1994-1999' Srsrsrrr 2000-2003 Sumer 2004-2006 Sunnier 2009-2013
Scientific nems Comm none No. % No. % NO. % No. % No. %
Lspeostetdr
Lspsospw osseus Largrross per 2 0.09% 3 0.09%
ClupNdr
Dorwams cepsdsnun Gizzard shad 32 3.40% 152 6.93% 86 3.40% 79 2.31% 51 1.52%
DorosomspoNnen" Thresdfinshad 158 15.79% 260 11.88% 337 13.33% 107 3.13% 67 2.00%
Cyprinidr
CyprlrW/s chlorlsds GreaNln shiner 1 0.11% 8 0.36% 10 0.40% 41 120% 6 0.18%
Cyprinslls IV~ Wl In show 5 0.53% 23 1.05% 109 4.31% 35 1.02% 14 0.42%
Cmd-wpio Carron coop 2 0.09% 2 0.08% 3 0.09% 1 0.03%
WotwrOgmusaysolsucas Golden show 9 0.36% 23 0.67%
lotalurldas
Amsirrus cslw WNM catfish 12 128% 107 4.88% 61 2.41% 29 0.85% 5 0.15%
Amatu'w nobdosw Brown buMad 1 0.04%
Amaturw plstyoophatw FW bullhead 1 0.05%
tcelww krcatw Bore catfish
letakrw puctatw Chsrnatcatfloh 2 021% 16 0.73% 25 0.99% 21 0.61% 21 0.83%
Fyladic6s dhris Fletlrsod cadloh 1 0.04% 3 0.09%
POsoMlidas
Gsmbwelrolbrouki Bsetwn rrosquilofloh 18 0.53% 4 0.12%
MoronWas
Moral Chrysops What bass 1 0.05%
Centrrchtdas
Lopom(s wilus Redbroast sunfish 138 14.67% 207 9.44% 109 4.31% 103 3.01% 102 3.D4%
Lspom(s oysnatlus Groan sunfish 6 0.85% 41 120% 102 3-04%
Loponda pibbosw P-VWnsaad 17 1.81% 36 1.84% 19 0.75% 12 0.35% 4 0.12%
Lepornis pdorra Werrroulh 24 2.55% 60 2.74% 83 328% 65 2.49% 40 1.19%
Lepomfs hybrid hybrid sunfish 2 0.21% 4 0.18% 5 020% 8 023% 12 0.38%
Lepornls macroclNrw BWoo 419 44.53% 1,078 49.18% 1,515 59.91% 2,471 72.27% 2,672 79.71%
Lspomis rWcrdophus Feder sunfish 27 2.87% 37 1.89% 47 1.86% 81 2.37% 83 2.48%
Alaoptsrw pnddshrs Spotted bass 2 0.08%
Mleroptrus sdmddos Lsrprroulh bees 90 9.56% 158 7.21% 93 3.86% 234 6.84% 156 4.65%
PWMIS dyaneculatus Block crappis 3 0.12% 8 023%
Percldss
L3600skims drnsfsd Tessellated darter 5 0.23% 4 0.12% 2 0.06%
Pace Rerssosns Yellow perch 6 0.64% 35 1.60% 14 0.55% 10 0.29% 8 024%
Totat no.Indhrkluats 941 100.00% 2,192 100.00% 2,529 100.00% 3,419 100.00% 3,352 100.00%
Total no.spaces 14 18 18 21 18
'Ummt[ae consisted of 200 man npMd shorsFs In 1991,1992,1994.sat 1996.
5-8

Table 5-3. Pelagic forage fish species composition from purse seine surveys in Lake Wylie,
1994-2013.
Species Composition
Year Threadfin shad Gizzard shad Alewife
1994 99.99% 0.01%
1995 100.00%
1996 99.77% 0.23%
1997 99.99% 0.01%
1999 99.96% 0.04%
2000 100.00%
2001 99.96% 0.02% 0.02%
2002 99.99% 0.01%
2003 99.10% 0.22% 0.68%
2004 89.21% 10.58%
2005 97.83% 2.17%
2006 99.65% 0.08% 0.27%
2007 100.00%
2008 100.00%
2009 99.99% 0.01%
2010 99.99% <0.01% <0.01%
2011 99.99% <0.01%
2012 99.33% 0.15% 0.52%
2013 97.89% 0.63% 1.48%
RECEIVED/DENR/DWR
OCT 15 2014
Water QwMy
PerMMr'9 Section
5-9

U"WOO Akn
MMM
$Man
"CA-Lvo\
V414C&ft oU C';a-.--
INA
scs
0 Summer electrofishing transects j-
• Spring electrofishing transects
♦ Purse seine locations
OSAM
N
ftfle Dom
o os 1 2 3 4
o 1:15 1 2 3 4
Figure 5-1. Locations associated with spring and summer electrofishmig surveys, and fall
purse surveys of Lake Wylie.
5-10

300
tAS
250 —i--REF
200
E
0
0
150
0
c
r
m
LL 100
50
0
CO It U*) CO r• M O O N M Ln CO r, M O O N M
(T O O O O O O O O O O O O O O O O
N N N N N N N N N N N N
Year
Figure 5-2.Total number of fish collected in spring electrofishing surveys from two areas
(AS and REF) in Lake Wylie, 1993 — 1997 and 1999—2013.
25
—#—AS
—*-REF
20
E 15
0
0
a�
Y
N 10
LL
5
0
M IT t1') (D i- C10 (A O MMO N M
O> O> O O O M M O O O O O O O O O O O O O O
N N N N N N N N N N N N N N
Year
Figure 5-3. Biomass of fish collected in spring electrofishing surveys from two areas (AS
and REF) in Lake Wylie, 1993 — 1997 and 1999—2013.
5-11

30
tAS
25 -11-REF
0 20
0
0
c
h 15
A
U
t 10
LL
5
0 p� �p pp p� CN CO
T 01 01 S O 2 a p O O O O a O O O O O
O O O O 0 w O O O O O O O O O O O O O O O
r r �
Year
Figure 5-4. Total number of fish species collected in spring electrofishing surveys from two
areas (AS and REF) in Lake Wylie, 1993— 1997 and 1999—2013.
14% -------------------------------------------
---------------------------------
■Above ■Discharge ■Below
12% ------------------------------ --------------------------------------------
c10% -------------------------- --------------------------------------------
0
p
.y
08% ------------------------- -- -------------------------------------
CL
0
U
yc6% -------------------- -- --------------------------------
a
2% ---------- - ----- --- - ----------------
0%
N w CO O N (0 C* O
TL class(mm)
Figure 5-5. Length distribution of bluegill among survey locations in summer electrofishing
surveys near AS in Lake Wylie,2009—2013.
5-12

70% ----------------------------------------------------------------------------
■Above ■Discharge ■Below
60% ------------ ---------------------------------------------------------------
c50% ------------ ---------------------------------------------------------------
0
N
a40% ------------ ---------------------------------------------------------------
E
0
0
Z30% -------------------------------------
m ------------ ------------------------ -
v
m
a.20% ------------ ------------------------ --------------------------------------
10% ------------ ---------------- --- --- -------------------------------------
0%
N V (00 COO O N V (O0 °Oo O
r N
TL class(mm)
Figure 5-6. Length distribution of redbreast sunfish among survey locations in summer
electrofishing surveys near AS in Lake Wylie,2009—2013.
30% ---------------------------------------------------------------------------
■Above ■Discharge ■Below
25% --------- -----------------------------------------------------------------
020% --
.. ------ ---------------------------------------------------------------
N
CL
E
15% -----------------------------------------------------------------
c
t
a10% -------- ----- -------- ---------------------------------------
5% ---- -------- ----- -------- -------- -- ---------------- ---------
0%
00 0 0 0 0 0 0 0 o O o 0
N f0 O CO N 0 M CO N <D O
r r � N N N C7 to C7 V d' �
TL class(mm)
Figure 5-7. Length distribution of largemouth bass among survey locations in summer
electrofishing surveys near AS in Lake Wylie,2009—2013.
5-13

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LITERATURE CITED
Brinkhurst,RO. 1974. The Benthos of Lakes. The MacMillan Press. London. 190 pp.
Buetow, D. 2008. 2007 Lake monitoring Report: Mecklenburg County Water Quality
Program, SWIM Phase I Part 2-CO. Mecklenburg County Department of
Environmental Protection. Charlotte,NC
Buetow, D. 2013. 2012 Lake monitoring Report: Mecklenburg County Water Quality
Program, SWIM Phase I Part 2-CO. Mecklenburg County Department of
Environmental Protection. Charlotte,NC
Duke Energy. 2009a. Assessment of balanced and indigenous populations in Lake Norman
near Marshall Steam Station. Duke Energy,Charlotte,NC.
Duke Energy. 2009b. Assessment of balanced and indigenous populations in Lake Wylie
near Allen Steam Station. Duke Energy,Charlotte,NC.
Duke Energy. 2009c. Assessment of balanced and indigenous populations in Mountain
Island Lake near Riverbend Steam Station. Duke Energy,Charlotte,NC.
Duke Energy. 2011a. Assessment of balanced and indigenous populations in Belews Lake
for Belews Creek Steam Station: NPDES No. NC0024406. August 2006. Duke
Energy, Huntersville,NC.
Duke Energy. 2011b. Lake Norman Maintenance Monitoring Program: 2010 Summary.
Duke Energy,Charlotte,NC.
Duke Energy. 2013. Assessment of balanced and indigenous populations in Lake Wylie
near Catawba Nuclear Station. Duke Energy,Charlotte,NC.
Duke Power. 1999. Assessment of balanced and indigenous populations in Lake Norman
near Marshall Steam Station. Duke Power,Charlotte,NC.
Duke Power. 2001a. Assessment of balanced and indigenous populations in Lake Wylie
near Plant Allen. Duke Power,Charlotte,NC.
L-1

Duke Power. 2001b. Assessment of balanced and indigenous populations in Mountain
Island Lake near Riverbend Steam Station. Duke Power,Charlotte,NC.
Duke Power. 2004a. Assessment of balanced and indigenous populations in Lake Norman
near Marshall Steam Station. Duke Power,Charlotte,NC.
Duke Power. 2004b. Assessment of balanced and indigenous populations in Lake Wylie
near Plant Allen. Duke Power,Charlotte,NC.
Duke Power. 2004c. Assessment of balanced and indigenous populations in Mountain
Island Lake near Riverbend Steam Station. Duke Power, Charlotte,NC.
Duke Power Company. 1976. Plant Allen 316(a) demonstration. Duke Power Company.
Charlotte,NC.
Duke Power Company. 1994. Assessment of balanced and indigenous populations in Lake
Wylie near Plant Allen. Duke Power Company, Charlotte,NC.
Hayes,DB, CP Ferrier, and WW Taylor. 2012. Active fish capture methods. Pages 267-304
in AV Zale, DL Parrish and TM Sutton, editors. Fisheries Techniques, 3rd edition.
American Fisheries Society,Bethesda,MD.
Milligan,MR. 1997. Identification manual for the Oligochaeta of Florida. Vol. 1. 187 pp
Neumann, RM, CS Guy, and DW Willis. 2012. Length, weight, and associated indices.
Pages 637-676 in AV Zale, DL Parrish and TM Sutton, editors. Fisheries
Techniques, 3rd edition. American Fisheries Society, Bethesda,MD.
North Carolina Department of Environment, Health, and Natural Resources (NCDEHNR).
1994. Basinwide assessment report support document, Catawba River basin.
NCDEHNR,Water Quality Section, Raleigh,NC.
NCDENR. 2008. Lake&reservoir assessments: Catawba River basin. NCDENR, Division
of Water Quality,Intensive Survey Unit.June 23,2008. Raleigh,NC.
NCDENR. 2011a. Permit to discharge wastewater under the National Pollutant Discharge
Elimination System: Duke Energy Carolinas, Plant Allen Steam Station, Gaston
County,NC.
L-2

NCDENR. 201 lb. Lake & reservoir assessments: Neuse River basin. NCDENR, Division
of Water Quality, Intensive Survey Unit. May 31, 2011. Raleigh,NC.
NCDENR. 2012. Lake & reservoir assessments: Yadkin-Pee Dee River basin. NCDENR,
Division of Water Quality,Intensive Survey Unit. March 13,2012. Raleigh,NC.
NCDENR. 2013. Lake &reservoir assessments: Catawba River basin. NCDENR, Division
of Water Quality,Intensive Survey Unit.July 18, 2013. Raleigh,NC.
NCDENR. 2013b. Standard operating procedure. Biological monitoring: stream fish
community assessment program. NCDENR, Division of Water Resources,
Environmental Sciences Section,Biological Assessment Branch. Raleigh,NC.
National Climatic Data Center (NCDC). 2013. NCDC Announces Warmest Year on
Record for Contiguous U.S. http://www.nc&.noaa.gov/news/ncdc-announces-
warmest-year-record-contiguous-us. (accessed: 08/26/2013).
Rudstam, LG, JM Jech, SL Parker-Stetter, JK Horne, PJ Sullivan, and DM Mason. 2012.
Fisheries acoustics. Pages 597-636 in AV Zale, DL Parrish and TM Sutton, editors.
Fisheries Techniques,3rd edition. American Fisheries Society,Bethesda,MD.
United States. Environmental Protection Agency (USEPA). 1977. Interagency 316(a)
technical guidance manual and guide for thermal effects sections of nuclear facilities
environmental impact statements. Draft May 1, 1977. USEPA Office of Water
Enforcement,Washington, DC.
Weiss, CM and EJ Kuenzler. 1976. The trophic state of North Carolina Lakes. University of
North Carolina,Water Resources Research Institute. July 1976. Chapel Hill,NC.
RECEIVED/DENR/DWR
OCT 16 2014
Wahl duality
Permuting Section
L-3

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APPENDIX

APPENDIX A
SPRING SEDIMENT AND HEXAGENIA SAMPLING IN LAKE WYLIE
SEDIMENT ANALYSIS
Methods
Spring sampling was conducted on Lake Wylie on April 13, 2010 for the purpose of
determining the presence and abundance of Hexagenia in spring samples, as well as for
sediment particle size analyses. Samples were collected at four locations in the vicinity of
the Allen Steam Station (AS): Location A, well uplake of AS; Location B, at the mouth of
the AS discharge; Location C, at the confluence of the South Fork and Catawba River; and,
Location D, a newly added location in the South Fork upstream of the AS discharge, roughly
between the Upper Armstrong bridge and the AS discharge(Figure 1).
A petite Ponar dredge (15.3cm X 15.3cm) was used to collect five replicate samples for
sediments from each location. Sediment replicates were composited in labeled five-gallon
buckets and returned to the lab for processing and analysis of particle size. Samples were
collected at depths ranging from two to three meters.
Each sediment composite was well mixed using a garden trawl and subsamples were
removed from each composite for individual analysis. Subsamples from each composite
were placed in Teflon-coated bake pans (5 cm in height, 20 cm in width, and 30 cm in
length). Pans were filled to the half-way mark with sediment, allowing for approximately
1,500 cm3 of sample. The amount of sediment from each five-grab composite was
determined by filling the drying pans with all of the material in each five-gallon bucket,
counting the number of pans of material then determining approximate volumes based on pan
volumes. Pans comprising one subsample from each composite were placed in a drying oven
at 70 °C (158 °F) for at least 24 hours to insure the samples were thoroughly dried. After
drying, the material was removed from the pans, broken up, and macerated to break up any
agglomerates.
A-1

Fifteen sieves were selected to break down samples into component particle sizes. Sieve
numbers and sizes are presented in Table 1. Racks of five sieves each were placed in a
mechanical shaker (W. S. Tyler, Co., RO-TAP. for 2.5 to 5.0 minutes. Fractions were
removed and placed in labeled sample containers. Each fraction was weighed on a one-
place, calibrated scale (Scout-Pro, OHAUS®, max. wt. 2,OOOg). The composition of particle
sizes was expressed as a percentage of the total weight of the subsample analyzed.
Results
Location A represented the largest volume of total sediment collected (= 6,000 cm3),
followed by Locations B (z 3,300 cm3), and D (= 3,200 cm). Location C had the least
amount of sediment volume (�z 2,100 cm3). This indicated that while considerable viable
substrate was available at Location A, the viable sediment layer at Location C was
comparatively thin and could have sat atop underlying hardpan clay or bedrock.
At Location A, the largest percentage(<48%)of the sediment ranged in size from 125 to 250
gm, representing mostly sand and fine sand particle sizes, with >35% of particles ranging
from <53 to 125 µm, in the silt to very fine sand range (Table 1, Figure 2). The largest
portion of the substrate at Location B (>38%) was in the range of coarse sand to granular
material (850 pm to 2.36 mm), with about one-third of the sediment in the sand to coarse
sand range (250 to <850 µm). At Location C, over 26% of the substrate collected was
greater than 4.75 mm. This large material was composed primarily of Corbicula shells and
shell fragments. Most of the remainder of the sediment at this location(>48%) consisted of
particles ranging from 125 to 850 µm, and could be described as sand ranging from fine to
coarse. Sediment at Location D was also composed mainly of particles ranging from 125 to
850 pm in size, but this range represented a much high percentage of total sediment(<79%).
Clearly, Location A not only represented far more available substrate than at other sites, but
substrate particle sizes more suitable for certain macroinvertebrate species, including
burrowing mayflies. Location B substrate was considerably less suitable based on particle
size, while substrate at Location D was also unsuitable based on larger particle sizes.
Location C appeared to be less habitable than other locations based on much less available
substrate and smaller proportions of suitable particle sizes.
A-2

HEUGENIA
Methods
Field sampling methods and laboratory methods for sorting macroinvertebrates were the
same as those presented in the five-year summary report of 2009 (Duke Energy, 2009c),
except that only Hexagenia were sorted and identified from sample replicates.
Results
Temperatures and dissolved oxygen concentrations were recorded from sampling depths at
each location on April 13 (Table 2). Temperatures ranged from 16.1 °C at Location D, the
newly added location upstream of the AS discharge to 23.1 °C at Location B, at the mouth of
the discharge. Dissolved oxygen concentrations ranged from 7.63 mg/L at Location C to
9.16 mg/L at Location D.
The highest numbers of Hexagenia were observed in replicates from Location A, while
Hexagenia were absent from all replicates collected from Locations C and D (Table 2).
Several Hexagenia were collected from Location B replicates. Compared to summer
populations, the mean density of Hexagenia from Location A was substantially higher than
summer densities observed at this location during 1994—2008 (Figure 3).
The absence of Hexagenia from Location C may have been due, in part, to the limited
amount and overall unsuitability of the substrate from that location. As to the absence of
these insects from Location D, substrate deficiencies may have also played a role since
substrate type was mostly sand and coarse sand(Table 1,Figure 2).
A-3

Table 1. Sediment sample weights, weights of particle fractions, and percent composition
of each fraction from samples collected on Lake Wylie,NC on April 13,2010.
Sieve Size Location A Location B Location C Location D
Number Wt. % Wt. % Wt. % Wt. %
4 4.75 mm 49.9 2.79 19.7 1.11 368.9 26.09 26.3 1.33
6 3.35 mm 11.4 0.64 17.5 0.98 7.1 0.50 15.3 0.77
8 2.36 mm 10.1 0.57 21.2 1.19 13.0 0.92 41.6 2.1
12 1.70 mm 10.0 0.56 172.3 9.68 27.9 1.97 25.9 1.31
16 1.18 mm 10.7 0.60 266.6 14.94 52.0 3.68 66.9 3.38
20 850 pm 11.3 0.63 251.0 14.1 47.2 3.34 41.3 2.09
30 600 PM 12.6 0.70 189.8 10.66 46.1 3.26 1 38.9 1.96
40 425 pm 55.4 3.1 190.8 10.72 59.7 4.22 70.9 3.58
60 250 pm 129.9 7.26 1 212.7 11.95 168.7 11.93 767.1 38.74
80 180 pm 157.9 8.82 81.5 4.58 176.5 12.48 515.0 26.01
100 150 pm 43.3 2.42 35.9 2.02 79.5 5.62 114.2 5.77
120 125 jim 652.4 36.46 50.6 2.84 155.6 11.01 55.9 2.82
140 106 pm 40.3 2.25 41.5 2.33 41.9 2.96 31.5 1.59
200 75 pm 384.7 21.5 1 89.8 5.04 112.2 7.94 52.0 2.63
270 53 pm 50.3 2.81 37.6 2.11 29.5 2.09 45.8 2.31
<53 pm 159.3 8.90 102.4 1 5.75 28.1 1.99 71.7 3.62
Total 1,789.4 1,780.3 1,413.9 1,980.3
A-4

Table 2. Raw counts of Hexagenia observed in samples collected on April 13, 2010, and
temperatures and dissolved oxygen values recorded at the time of sampling.
Loc. Rep.I Rep.2 Rep.3 Rep.4 Rep.5 Mean Tem °C DO m L
A 8 4 11 11 6 8.0 16.8 8.57
B 0 2 0 1 0 0.6 23.1 8.29
C 0 0 0 0 0 0 20.6 7.63
D 0 0 0 0 0 0 16.1 9.16
A-5

i
t
�11i1N1d aMl
F
:T
7w7—K�r7--w——7��7.T 1
9H•l236 � `�"'��
A
ARM
ftdono
p�' 10RIN GIML1M
1rlCwly sokrm GRCLI4
r
W41M C '
SC 657
t�tlen � N
DOM
0 05 1 2 i t 9
j \
wn
0 06 1 2 l 4
Figure 1. Macroinvertebrate and sediment monitoring locations in the vicinity of Allen
Steam Station on Lake Wylie,NC sampled on April 13, 2010.
A-6
I

0 Location A 0 Location 0 m Location C a Location D
so ---------—-—------------------------------------------ ——------..........
45 ---------------------
35
30
25
20
is .............. ------------------ ----
10 ------- .......
5 -------- ----
>41.75 nwn >2.36.4.75 mm )--Mpm-2.36nvn 2--250-850{un >125-250 Wn <53-125tim
PM Has Sam
Figure 2. Sediment particle size composition at locations sampled in Lake Wylie, NC on
April 13,2010.
0 Location A 0 Location B a Location C
400
350
300
250
200
ISO
100
so
0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 SPR.
2010
Figure 3. Mean densities (No./m2) of Hexagenia collected annually at all locations from
1994 to 2008 and densities recorded from three locations in the spring of 2010. No
Hexagenia were collected at newly added Location D.
A-7

LITERATURE CITED
Duke Energy. 2009. Assessment of balanced and indigenous populations in Lake Wylie near
Plant Allen. Duke Energy, Charlotte,NC.
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