NC0004979_2019 316(a) Study Plan_20190123

14% DUKE
ENERGY
January 23, 2019
Ms. Cyndi Karoly, Chief
Water Sciences Section
North Carolina Department of Environmental Quality
1621 Mail Service Center
Raleigh, NC 27699-1621
Subject: Duke Energy Allen Steam Station, NPDES Permit NCO004979
2019 316(a) Study Plan
Aller Stearn Statim
253 Plant Allen Rd.
Belmont, NC 28012
704 829-2587
Dear Ms. Karoly:
The purpose of this letter is to transmit the 2019 Allen Steam Station 316(a) Study Plan for NCDEQ review and approval, as
required in Section A. (2 1) of the Allen Steam Station NPDES permit (NC0004979). The 2019 Study Plan was developed to
address the elements necessary to demonstrate a balanced and indigenous community (BIC) in Lake Wylie and support a thermal
variance in accordance with Section 316(a) of the Clean Water Act.
We look forward to your review and approval of the 2019 316(x) Study Plan for Allen Steam Station. Should you have questions
please feel free to contact Matt McKinney at 980-875-5526, or via email at matt,mckinney0a duke-energy.com.
Sincerely,
Terry Tuck, General Manager II
Duke Energy Carolinas, LLC
Allen Steam Station
Cc
Scott Fletcher Duke Energy, MG03A3
Elizabeth Glenn Duke Energy, EC13K
Michael Gantt Duke Energy, Allen Steam Station
UPS Tracking: Raleigh 1Z X67 601 24 9129 0538

2019 LAKE WYLIE §316(a) STUDY PLAN
ALLEN STEAM STATION
JANUARY 2019
(� DUKE
ENERGY.

2019 LAKE WYUE 6316(a) STUDY PLAN
ALLEN STEAM STATJON
Contents
1 Introducton........................................................................................................................1
IABatkground ........ . ......... ............ ..... .... ....................... .... .... .............. i
1 .2 Envlroon%rNtW Monitoring History .............................. ........... .......... ..................... ..... ,,,1
StudyGoals and Oktfres...............................................................................................1
3 Study Plan.........................................................................................................................
3.1 Fish............................................................................................................................................2
3.2 Temperature Analysis................................................................................................................3
33 Limnology ..................................................................................................................................3
3AHabitat Formers .........................................................................................................................4
,5 Phytoplankton and 7ooplankton ................................................................................................4
3,6 Benthic Ma>.rainvertebrates.......................................................................................................4
.7 Other Vertebrate Wildlife...........................................................................................................4
.8 Endangered Species.................................................................................................................6
4 Data Management ............................................................................................................. 5
5 Study Tirtteline and Reporting............................................................................................ 5
6 Reference........................................................................................................................5
Appendices
Appendix A Maps
Appenft B SWdy Plans Summary Fables

2019 LAKE WYLIE §316(a) STUDY PLAN
ALLEN STEAM STATION
1 Introduction
1.1 Background
Allen Steam Station (Allen) is located approximately 10 miles west of Charlotte, North Carolina
on Lake Wylie (Figure A-1, Appendix A). The construction of Wylie Dam in 1904 created a
reservoir with over 300 miles of shoreline and nearly 3,500 surface acres. In addition to
providing a source of water for hydroelectric generation, Lake Wylie also provides cooling water
for Allen and Duke Energy's Catawba Nuclear Station, municipal water supply for several
nearby towns, and is used for recreation (primarily boating and fishing). Allen is a five -unit, coal-
fired, electric generating facility with a nameplate capacity of 1,145 megawatts (MW). Units 1
and 2 are rated at 165 MW each and began operation in 1957. Unit 3 and Unit 4, rated at 265
MW and 280 MW, began commercial operation in 1959 and 1960. Unit 5, rated at 270 MW,
began operation in 1961. All units operate in a once -through cooling mode with water withdrawn
from a single cooling water intake structure (CWIS), slightly recessed from the original shoreline
along the Catawba River arm of Lake Wylie. The heated condenser cooling water (CCW)
effluent is discharged via a man-made canal into the South Fork Catawba River arm.
The current National Pollutant Discharge Elimination System (NPDES) (NCDEQ 2018)
permitted thermal limits under §316(a) of the Clean Water Act (CWA) for Allen's CCW effluent
include a monthly average discharge temperature limit of 38.9'C (102'F) during June 1 through
September 31, and a monthly average temperature limit of 35"C (95 'F) during October 1
through May 31. To maintain this variance and in accordance with Section A. (21) in the new
permit, `?he next 316(a) studies shall be performed in accordance with the Division of Water
Resources approved plan. The temperature analysis and the balanced and indigenous study
plan shall conform to the specifications outlined in 40 CFR 125 Subpart H, the Environmental
Protection Agency's (USEPA) Draft 316(a) Guidance Manual, dated 1977, and Region 4 letter
to North Carolina Department of Environment and Natural Resources (NCDENR), dated June 2,
2010."
1.2 Environmental Monitoring History
Duke Energy (then Duke Power Company) sponsored an initial §316(a) demonstration study for
Allen during 1973-1974 soon after CWA legislation was enacted in 1972 (Duke Power
Company 1976). This included intensive studies of the lake's ecology and chemical properties.
Since then, Duke Energy has performed annual fisheries and water quality sampling on the lake
at varying frequencies from 1978 to the late 1980's, and annually since 1993. These studies
also included benthic macroinvertebrates and primary production assessments at varying
frequencies. The most recent balanced indigenous community (BIC) report for this sampling
was submitted under the previous permit in 2014 (Duke Energy 2014).
2 Study Goals and Objectives
Beginning in 2019 and in accordance with the recently issued NPDES permit no. NC0004979,
Section A. (21), Duke Energy will conduct studies to address the elements necessary to
demonstrate a BIC in Lake Wylie. As stated in this most recent permit, effective August 1, 2018,

2019 LAKE WYLIE §316(a) STUDY PLAN
ALLEN STEAM STATION
"...the thermal component of the discharge assures the protection and propagation of a
balanced, indigenous population of shellfish, fish and wildlife in the receiving water body." The
objective of this Study Plan, therefore is to outline the studies necessary for continuation of this
determination for the next permit renewal with the following two primary goals:
1. Demonstrate the protection and propagation of a BIC of aquatic wildlife through
biological surveys, and
2. Perform a temperature analysis to produce new thermal maps.
Data collected during this study will be evaluated against four primary BIC criteria defined in 40
CFR 125.71. The four criteria state that BICs are biotic communities typically characterized by:
a. Having diversity and representative trophic levels within expectations,
b. The ability to self -sustain through successful reproduction and recruitment over seasonal
changes,
c. Having adequate food items, and
d. A lack of domination by pollution tolerant species.
3 Study Plan
The following describes the study components of the proposed Lake Wylie 316(a) study. The
different sampling programs, locations and frequencies are included in Table B-1, Appendix B.
3.1 Fish
The 2019 Study Plan includes twenty (20) new fish community sampling sites (shoreline
transects), the same number of sites as in recent years (Figure A-1, Appendix A). The new
sites, however, are more widely distributed throughout Lake Wylie for characterizing fish
communities, and include new "cold water" reference sites upstream of Allen (Zone D) on the
mainstem Catawba River arm. The new sites were selected using a stratified random design to
select for areas thermally vs non -thermally influenced and those that were considered in the
main channel versus `off -channel' (e.g., tributary arms and coves). Furthermore, the new sites
were categorized as falling within one of the following four zones:
Zone A — Catawba Nuclear Station thermally influenced area,
Zone B — Catawba Nuclear Station non -thermally influenced reference area,
Zone C — Allen thermally influenced area, and
Zone D — Allen non -thermally influenced reference area.
Boat electrofishing (approximately 1,000 seconds of effort per transect) will be used to sample
each site according to standard fisheries methods (Miranda and Boxrucker 2009, Zale et al.
2012) and Duke Energy procedure FSH -250.05. Transects will be sampled during the day with

2019 LAKE WYLIE §316(a) STUDY PLAN
ALLEN STEAM STATION
a Smith -Root GPP electrofisher mounted on a Smith -Root boat, using pulsed DC current. At
each sampling site, a transect will be established parallel to the shoreline that will not overlap
with other transects. Species identification, enumeration and individual total length (nearest
millimeter) and weight (nearest gram) will be recorded for fish collected in each transect. Fish
will also be inspected for parasites and any deformities. If fish are not identifiable in the field
they will be preserved and taken back to the lab for identification by Duke Energy fishery
scientists. Water quality measurements (temperature, conductivity, dissolved oxygen and pH)
will be taken at each transect with a calibrated probe to evaluate environmental conditions at the
time of sampling.
Fish community surveys will be performed in the spring and fall, an increase from previous
once -per -year approaches; however, sampling will occur every other year under the next permit
term instead of annually as in previous terms. Review of historical data in Lake Wylie suggest
abundant and diverse communities occur therein, and reducing the annual sampling frequency
will not jeopardize the BIC determination. Therefore, we anticipate having at least two years of
fisheries data collected on a semi-annual basis, along with all historical data for reference in the
next environmental monitoring report.
Fisheries surreys will determine whether a reasonable and acceptable BIC exists in Lake Wylie
despite the thermal discharge to the lake. As stated above, a BIC should be diverse and contain
different trophic levels, be self-sustaining year to year, not be dominated by pollution -tolerant
species, and contain adequate food items. Metrics collected on fish species selected as
representative important species (RIS; Largemouth Bass Micropterus salmoides, Bluegill
Lepomis macrochirus, and Redbreast Sunfish L. auritus) will help determine this BIC.
Data analysis will consist of total taxa numbers and biomass, mean CPUE calculations, spatial
comparisons of RIS, length distributions, species pollution tolerance, trophic guild, and hybrid
complexes. To assess the potential thermal effects of Allen, comparisons will be made between
the Allen thermally influenced zone (Zone C) and its associated reference zone (Zone D).
Additionally, metrics will be calculated on a lake -wide basis.
3.2 Temperature Analysis
To address the temperature analysis requirement in the permit, Duke Energy will update the
depiction of thermally influenced areas and areas not influenced by thermal inputs to the lake
using temperature information from a CE -QUAL -W2 hydrodynamic model of Lake Wylie. This
model is a two-dimensional, longitudinal and vertical water quality model from which extreme
winter and summer conditions can be retrieved for producing new maps. The approach will be
the same used to update thermal maps for Lake Norman (Duke Energy 2017). The thermal
maps will be updated based on the model outputs and will be included in the environmental
monitoring report required for the next permit renewal application.
3.3 Limnology
Beginning in 2019 and for the duration of the permit term, in-situ water quality monitoring and
water chemistry sample collection will be performed twice per year (Figure A-2, Appendix A).
These data will be incorporated into the 316(x) study to address any potential water

2019 LAKE WYLIE §316(a) STUDY PLAN
ALLEN STEAM STATION
quality/chemistry interactions with the thermal effluent (e.g., dissolved oxygen, chlorophyll a,
etc.) that may affect the BIC. A list of variables in the sampling program can be found in Table
B-1, Appendix B.
3.4 Habitat Formers
Qualitative habitat former (e.g., aquatic vegetation) surveys will be conducted in the summer for
at least two years in the next permit term. Presence and spatial distribution of habitat formers
will be recorded in thermally influenced areas and reference areas. All visible aquatic vegetation
species (submerged, floating and emergent) will be noted.
3.5 Phytoplankton and Zooplankton
Phytoplankton and zooplankton are generally considered to be low potential impact (LPI) biotic
categories, therefore narrative assessments of these components will be made and included
within the framework of the Lake Wylie BIC. Scientific literature will be surveyed along with any
historical data collected from Lake Wylie (Duke Energy 2013). The validity of using a narrative
approach can be found in the most recent 316(a) review by Coutant (2013).
3.6 Benthic Macroinvertebrates
As above for phytoplankton and zooplankton, benthic macroi nverteb rates are generally
considered to be LPI biotic categories, therefore narrative assessments of these components
will be made and included within the framework of the Lake Wylie BIC. Scientific literature will
be surveyed along with any historical data collected from Lake Wylie. (Duke Energy 2014).
3.7 Other Vertebrate Wildlife
In addition to aquatic biota, Duke Energy will conduct observations regarding "other vertebrate
wildlife" (wildlife) that are associated with aquatic habitats and/or rely on the waters for foraging,
reproduction, and other life functions (e.g., waterfowl, Bald Eagles, aquatic mammals,
amphibians).
According to the USEPA 1977 316(a) Technical Guidance Document, most sites in the United
States will likely be considered ones of LPI for other vertebrate wildlife simply because thermal
discharge plumes should not generally impact large or unique populations of wildlife (e.g.,
waterfowl concentrations, eagle wintering areas). Exceptions to sites classified as LPI would be
those few sites where the discharge might affect protected, RIS, or threatened and endangered
wildlife.
Observations for wildlife will be conducted by a Certified Wildlife Biologist at sampling sites
similar in general location to those being conducted for the fisheries study component (Braun
2005; Heyer et. al., 1994; Wilson et.al., 1996). The observations will also be conducted in the
same time period (e.g., month, season) as the fisheries fieldwork. Observations will be
augmented by literature reviews of pertinent information (e.g., U.S. Fish and Wildlife Services
(USFWS) listed species county list, USFWS Information for Planning and Construction
database, facility -specific reports) which will enable Duke Energy to prepare rationale regarding
4

2019 LAKE WYLIE §316(a) STUDY PLAN
ALLEN STEAM STATION
why the site should be considered one of low potential impact or an exception to that.
Observations will be conducted for aquatic wildlife species or species that use Lake Wylie
during activities such as foraging for fish or other life function activities. Duke Energy will not be
documenting wildlife species that do not fit the criteria mentioned above (e.g., white-tailed deer,
most songbirds and wild turkeys).
3.8 Endangered Species
The USFWS map -based search tool Information Planning and Consultation (IPaC), as well as
other Duke Energy derived aquatic species data was reviewed to determine the potential
presence of federally listed species within Lake Wylie and the surrounding counties (USFWS
2018). The Carolina Heelsplitter (Lasmigona decorata) is the only aquatic species identified in a
search of the IPaC database. The Carolina Heelsplitter is an endangered freshwater mollusk
that requires cool, clean, well -oxygenated water with silt -free stream bottoms and stable, well -
vegetated stream banks (USFWS 2017). The nearest known population of Carolina Heelsplitter
and critical habitat designated by the USFWS (2017) is located over 22 miles downstream from
Lake Wylie, and is hydrologically disconnected by Wylie Dam. Therefore, no assessment of
endangered species will be included in the next BIC report.
4 Data Management
All data collected by Duke Energy for the Allen 316(a) study will be digitally recorded and
uploaded into Duke Energy's EQuIS database for retrieval and analysis. EQuIS is a powerful
software tool produced by Earthsoft® which Duke Energy will use for the management of
biological and analytical data. Internal QA/QC processes will be established to ensure accuracy
of data being submitted to the EQuIS database.
5 Study Timeline and Reporting
The Allen 316(a) study will commence once the final study plan is approved by the NCDEQ and
EPA, with an anticipated start in April 2019. Studies will continue through 2022, after which a
four-year report will be prepared for the next permit renewal application.
6 References
Braun, C. E., editor. 2005. Techniques for Wildlife Investigations and Management. Sixth
edition. The Wildlife Society. Bethesda, MD.
Coutant, C. 2013. Considerations and requirements for biological determinations related to
thermal discharges. Special Report No. 13-02. National Council for Air and Stream
Improvement. August 2013.
Duke Energy. 2017. 2018 Lake Norman 316(a) Study Plan, McGuire Nuclear Station. Duke
Energy NPDES Permit NC0024392.

2019 LAKE WYLIE §316(a) STUDY PLAN
ALLEN STEAM STATION
Duke Energy. 2014. Assessment of balanced and indigenous populations in Lake Wylie near
Allen Steam Station. 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 Company. 1976. 316a Demonstration, Allen Steam Station. Duke Power
Company, Charlotte, NC. March 1976.
Heyer, W. R., M. Donnelly, R. McDiarmid, L. Hayek, and M. Foster, editors. 1994. Measuring
and Monitoring Biological Diversity. Standards Methods for Amphibians. Smithsonian
Institution Press. Washington and London.
Miranda, L. E. and J. Boxrucker. 2009. Warmwater fish in large standing waters. Pages 29-42
in S. A. Bonar, W. A. Hubert, and D. W. Willis, editors. Standard methods for sampling
North American freshwater fishes. American Fisheries Society, Bethesda, Maryland.
North Carolina Department of Environmental Quality (NCDEQ). 2018. Permit to discharge
wastewater under the National Pollutant Discharge Elimination System: Duke Energy
Carolinas, Plant Allen Steam Station, Gaston County, NC.
U.S. Fish and Wildlife Service (USFWS). 2017. South Carolina Field Office. Endangered
Species. Carolina Heelsplitter. Accessed October 24, 2018. [URL]:
https://www.fws.gov/charleston/heeisplitter.html.
U.S. Fish and Wildlife Service (USFWS). 2018. Information for Planning and Consultation
(IPaC). Accessed 11/15/2018. [URL]: https:/lecos.fws.gov/ipac/location/index. Van Horn,
S. L. 1978. Development of the sport fish potential of an industrial cooling lake. North
Carolina Wildlife Resource Commission, Division of Inland Fisheries. Raleigh, NC.
Wilson, D., F. R. Cole, J. Nichols, R. Rudran, and M. Foster, editors. 1996. Measuring and
Monitoring Biological Diversity. Standards Methods for Mammals. Smithsonian Institution
Press. Washington and London.
Zale, A. V., D. L. Parrish and T. M. Sutton, editors. 2012. Fisheries Techniques, third edition.
American Fisheries Society. Bethesda, MD.
6

2019 LAKE WYLIE 5316(a) STUDY PLAN
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Appendix A
Maps

2019 LAKE WYLIE §316(a) STUDY PLAN
ALLEN STEAM STATION
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8

2019 LAKE WYLIE §316(a) STUDY PLAN
ALLEN STEAM STA" !ON
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9

2019 LAKE WYLIE §316(a) STUDY PLAN
ALLEN STEAM STAT ON
Appendix B
Study Plan Summary Tables
1;i

2019 LAKE WYLIE §316(a) STUDY PLAN
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Table B-1. Alien 316(a) study plan summary table.
PROGRAM
FREQUENCY
LOCATION
Water quality'
In-situ grab w/ BE'
Semi-annual (Spring/Fall)
20 locations (Figures A-1)
In-situ profile (Limnology)
Semi-annual
(SummerMlinter)
7 locations (Figure A-2)
Water chemistry3
Analytical
Semi-annual
(Summer/Winter)
7 locations (Figure A-2)
Fisheries
Boat Electrofishing (BE)2
Semi-annual (Spring/Fall)
20 locations (Figures A-1)
Chlorophyll-a/Plankton4
Photic zone grab
Annual (Summer)
250, 235, 225, 200 (Figure A-2)
Other Vertebrate Wildlife
Thermal discharge and reference
Visual observations
Summer
areas
Habitat Formers
Visual observations
Summer
Thermal discharge and reference
areas
'In-situ water quality are measurements made in the water column using submersible sensors
and recorded on a computer.
' Fish sampling will be conducted during odd number years beginning in 2019.
,Analytical refers to water grab samples taken from the surface (unless otherwise specified),
placed in sample bottles, and returned to the laboratory for analysis.
4 Chlorophyll -a and phytoplankton will be collected at select locations during the summer WQ/WC sample
and!or anytime at a given WQMC location if field parameters (DO Sat% X120 and pH > 9) indicate a
bloom is occurring; samples may also be taken if visual observations suggest so (i.e., noticeable
bloom or fish kill). A composite grab sample will be collected using an integrated depth sampler in
the photic zone or using a Van Dorn sampler. Phytoplankton samples will be preserved and only
analyzed if chlorophyll -a is n 40 µg.
M

2019 LAKE WYLIE §316(a) STUDY PLAN
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Sample Variables
In-situ w/ Electrofishing
• Surface temperature, dissolved oxygen (DO) concentration, DO saturation, Spec
cond, pH
In-situ (Limnology)
• Temperature, DO concentration, DO saturation, specific conductance, pH profiles
o Surface to 10m @ 1 m intervals, 1 Om to bottom @ 2m intervals within water
column
• Measured Secchi Depth (m)
• Surface turbidity
Analytical (Limnology)
• Major Ions
o Total calcium, magnesium, chloride, sulfate
• Nutrients'
o Total phosphorus, orthophosphorus, ammonia nitrogen, nitrate+nitrite
nitrogen, TKN, Chlorophyll -a (select sites)
• Metals
o Total copper, zinc, lead
c. Dissolved copper, zinc, lead
4 See footnote 4 above for chlorophyll -a sampling; same methodo ogy to be used for nutrients
1r,