NC0004774_Clean Water Act Section Submittal_20220502

DUKEDuke Energy
�JI� Buck Combined Cycle
ENERGY 1385 Dukeville Road
Salisbury,NC 28146
April 25, 2022 RECEIVED
North Carolina Department of Environmental Quality MAr 0 2 2022
Division of Water Resources
1617 Mail Service Center NCDEQIDWRINPDES
Raleigh NC 27699-1617
RE: Duke Energy Carolinas, LLC
Buck Combined Cycle Station, NPDES Permit NC0004774
Part A. (20.) Clean Water Act Section 316(b) Submittal
Dear Sir or Madam:
In accordance with the provisions of NPDES Permit NC0004774, Part A.(20.), following
and enclosed is our timely submittal of the requested Clean Water Act § 316(b)
information for the Buck Combined Cycle Statio
n. Specifically, the Department has
requested that the submitted 316(b) information be provided by April 30, 2022. We
believe that this submittal completely satisfies this obligation.
As detailed in the enclosed reports, the Buck Combined Cycle Station meets Best
Technology Available for impingement and entrainment with existing closed cycle
cooling using mechanical draft cooling towers. Additional protective measures include
cylindrical wedgewire intake screens with a design through-screen velocity less than 0.5
feet per second.
Please contact Michael Smallwood ([e-mail], 704-382-
4117) or Steve Cahoon ([e-mail], 919-546-7457) if there are
any questions regarding this submittal.
Sincerely,
Kris Eisenrieth,
General Manager II, Buck Combined Cycle Station
Attachment: Buck Combined Cycle Station 316(b) study reports
USPS: 7019 0140 0001 0794 0883 / 9590 9402 5350 9154 1985 52

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Clean Water Act § 316(b)
Compliance Submittal
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NPDES Permit NC0004774
Duke Energy Environmental Services Environmental Programs
526 South Church Street
Charlotte NC 28202
April 2022
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316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
Contents
Executive Summary 1
1 Introduction 4
2 Source Water Physical Data [§122.21(r)(2)] 7
2.1 Description of Source Waterbody[§122.21(r)(2)(i)] 7
2.2 Characterization of Source Waterbody[§122.21(r)(2)(ii)] 8
2.2.1 Geomorphology 8
2.2.2 Hydrology 8
2.2.3 Water Quality 11
2.3 Locational Maps[§ 122.21(r)(2)(ii) 14
3 Cooling Water Intake Structure Data [§ 122.21(r)(3)] 15
3.1 Description of MWIS Configuration [§122.21(r)(3)(i)] 15
3.2 Latitude and Longitude of MWIS[§122.21(r)(3)(ii)] 20
3.3 Description of MWIS Operation [§122.21(r)(3)(iii)] 20
3.4 Description of Intake Flows[§122.21(r)(3)(iv)] 21
3.5 Engineering Drawings of CWIS[§122.21(r)(3)(v)] 21
4 Source Water Baseline Biological Characterization Data [§122.21(r)(4)] 22
4.1 List of Unavailable Biological Data [§122.21(r)(4)(i)] 22
4.2 List of Species and Relative Abundance in the vicinity of CWIS[§122.21(r)(4)(ii)] 23
4.2.1 Electrofishing 25
4.3 Primary Growth Period 28
4.3.1 Reproduction and Recruitment 28
4.3.2 Period of Peak Abundance for Relevant Taxa 33
4.4 Daily and Seasonal Activities of Organisms in the Vicinity of the MWIS 33
4.5 Species and Life Stages Susceptible to Impingement and Entrainment 34
4.5.1 Impingement 34
4.5.2 Entrainment 34
4.6 Threatened,Endangered,and Other Protected Species Susceptible to Impingement and
Entrainment at the MWIS 35
4.7 Documentation of Consultation with Services 35
4.8 Information Submitted to Obtain Incidental Take Exemption or Authorization from Services 35
4.9 Methods and Quality Assurance Procedures for Field Efforts 36
4.10 Protective Measures and Stabilization Activities 36
4.11 Fragile Species 36
5 Cooling Water System Data [§122.21(r)(5)(i)] 37
5.1 Description of Cooling Water System Operation [§122.21(r)(5)(i)] 37
5.1.1 Cooling Water System Operation 37
5.1.2 Proportion of Design Flow Used in the Cooling Water System 38
5.1.3 Cooling Water System Operation Characterization 39
5.1.4 Distribution of Water Reuse 40

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
5.1.5 Description of Reductions in Total Water Withdrawals 40
5.1.6 Description of Cooling Water Used in Manufacturing Process 41
5.1.7 Proportion of Source Waterbody Withdrawn 41
5.2 Design and Engineering Calculations[§122.21(r)(5)(ii)] 41
5.3 Description of Existing Impingement and Entrainment Reduction Measures[§122.21(r)(5)(iii)] 42
5.3.1 Best Technology Available for Entrainment 42
6 Chosen Method(s)of Compliance with Impingement Mortality Standard [§122.21(r)(6)] 44
7 Entrainment Performance Studies [§ 122.21(r)(7)] 46
7.1 Site-Specific Studies 46
7.2 Studies Conducted at Other Locations 46
8 Operational Status 122.21 r 8 47
8.1 Description of Operating Status[§122.21(r)(8)(i)] 47
8.1.1 Individual Unit Age 47
8.1.2 Utilization for Previous Five Years 47
8.1.3 Major Upgrades in Last Fifteen Years 48
8.2 Description of Consultation with Nuclear Regulatory Commission [§122.21(r)(8)(ii)] 48
8.3 Other Cooling Water Uses for Process Units[§122.21(r)(8)(iii)] 48
8.4 Description of Current and Future Production Schedules[§122.21(r)(8)(iv)] 48
8.5 Description of Plans or Schedules for New Units Planned within Five Years[§122.21(r)(8)(v)] 48
9 References 49
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BUCK COMBINED CYCLE STATION
Tables
Table 1-1. Facility and Flow Attributes and Permit Application Requirements 5
Table 1-2.Summary of§316(b) Rule for Existing Facilities Submittal Requirements for§122.21(r)(2)-(8). 6
Table 2-1. Mean annual flow(MAF) of the Yadkin River and South Yadkin River since 2010,as measured at the
USGS Yadkin River at Yadkin College Gage (02116500) and USGS South Yadkin River Gage, near Mocksville, NC
(02118000)since 2010. 10
Table 2-2.Yadkin River mean monthly flow(cfs)at the USGS Yadkin River Gage at Yadkin College(02116500)
since 2010. 10
Table 2-3. Mean monthly flow(cfs) at the USGS South Yadkin River Gage, near Mocksville, NC Gage
(02118000) since 2010 11
Table 2-2. Mean (range)concentration for select water quality parameters documented in the Yadkin River
near the BCCS MWIS from 2017-2020. 11
Table 3-1. BCCS MWIS Monthly Total Withdrawals During 2017-2021. 21
Table 4-1. Fish species collected by Duke Energy in the Yadkin River since 2000, and their associated pollution
tolerance,trophic guild,and native origin status. 23
Table 4-2. Fish species and numbers collected during electrofishing from all zones combined in the Yadkin
River. 25
Table 4-3. Mean (and range)of water quality parameters for all sites combined during electrofishing in 2000-
2012 and 2018. 27
Table 4-4. Habitat, diet,and spawning characteristics of select species present in the Yadkin River near the
BCCS. 31
Table 4-5. Primary period of reproduction for select species present in the Yadkin River(Sources: Ross 2001;
Rohde et al. 2009).1 33
Table 4-6. Results of preliminary impingement data collected at Buck in 2006 under the Phase II Rule
(unpublished data). [former BSS CWIS and not representative of the current BCCS MWIS] 34
Table 5-1. Percent Monthly Proportion of Design Flow Withdrawn at the BCCS 39
Table 5-2. Comparison of BSS and BCCS. 40
Table 5-3. BCCS Percent of Source Waterbody(Yadkin River) Withdrawal 41
Table 5-4. MWIS TSV Calculations 41
Table 8-1. BCCS Annual Capacity Factors, 2017-2021. 48
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316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
Figures
Figure 2-1. Map Showing the BCCS MWIS in the Yadkin River Basin 9
Figure 2-2. Duke Energy biological and water quality(Locations B and C) sampling locations in proximity to the
BCCS. 13
Figure 3-1. BCCS Water Balance Diagram 17
Figure 3-2. Plan View of MWIS at the BCCS 18
Figure 3-3. Section View of MWIS at the BCCS 19
Figure 3-4. Wedgewire Screen Design of BCCS 20
Figure 4-1.Total abundance (CPUE) by number of all fish species collected within all zones from electrofishing
in the Yadkin River during winter 2000-2012, summer 2000-2011,and fall 2018 27
Figure 4-2. Length-frequency of four numerically dominant species collected in the Yadkin River from all sites
sampled in Winter 2000-2012, Summer 2000-2011, and Fall 2018 combined. 29
Figure 4-3.Abundance (fish/hr) of four numerically dominant species collected in the Yadkin River from all
sites sampled in Winter 2000-2012, Summer 2000-2011, and Fall 2018 combined 30
Figure 5-1. BCCS Cooling Tower General Arrangement 38
Figure 5-2. Monthly Total MWIS Withdrawals at BCCS 40
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316(b) Compliance Submittai`'
BUCK COMBINED CYCLE STATION
Appendices
Appendix A. Buck Combined Cycle Station § 122.21(r)(2)-(8) Submittal Requirement Checklist.
Appendix B. Engineering Drawings of Makeup Water Intake Structure.
Appendix C. Engineering Calculations for Through-Screen Velocity.
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316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
Abbreviations
°C degrees Celsius
°F degrees Fahrenheit
µS/cm micro Siemens per centimeter
AIF actual intake flow
AOI area of influence
BCCS Buck Combined Cycle Station
BSS Buck Steam Station
BTA Best Technology Available
CCC closed cycle cooling
CFR Code of Federal Regulations
cfs cubic feet per second
cm centimeter
COC cycles of concentration
CWA Clean Water Act
CWIS Cooling Water Intake Structure
DIF design intake flow
Director NPDES Director
DO dissolved oxygen
Duke Energy Duke Energy Carolinas,LLC
EPA United States Environmental Protection Agency
ESA Endangered Species Act
fps feet per second
ft foot/feet
ft msl feet above mean sea level
gpm gallons per minute
HRSG heat recovery steam generator
HUC Hydrologic Unit Code
IPaC Information for Planning Conservation
IRP Integrated Resource Plan
m meter
µm micrometer
µ5/cm microsiemens per centimeter
m3 cubic meters
MDCT mechanical draft cooling tower
MGD million gallons per day
mg/L milligrams per liter
mm millimeters
MW megawatts
MWIS Makeup Water Intake Structure
NCDEQ North Carolina Department of Environmental Quality
NCNHP North Carolina Natural Heritage Program
NMFS National Marine Fisheries Service
NPDES National Pollutant Discharge Elimination System
NRDAR Natural Resource Damage Assessment and Restoration
NTU Nephelometric Turbidity Units
OTC once-through cooling
QA Quality Assurance
POA percent open area
rkm river kilometers
Rule Clean Water Act§316(b)rule
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316(b) Compliance Submittal
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BUCK COMBINED CYCLE STATION
RTE rare,threatened,or endangered
TL total length
TSV through-screen velocity
USEPA U.S.Environmental Protection Agency
USFWS U.S.Fish and Wildlife Service
USGS U.S.Geological Survey
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316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
Executive Summary
On August 15,2014, regulations implementing§316(b)of the final Clean Water Act(CWA)rule for existing
facilities (the Rule) were published in the Federal Register with an effective date of October 14, 2014.
Facilities subject to the Rule are required to develop and submit technical material, in accordance with
§122.21(r), that will be used by the National Pollutant Discharge Elimination System (NPDES) permit
Director(Director)to make a Best Technology Available (BTA) determination for the facility.
The Buck Combined Cycle Station (BCCS) began commercial operations in November 2011, replacing four
coal-fired units which were subsequently demolished. BCCS is a single combined cycle unit, natural gas-
fired electric generating facility with a current generating capacity of 620 MW. BCCS wastewater
discharges are authorized by NPDES Permit NC0004774.Therefore, BCCS is an existing facility and subject
to the Rule.
The §122.21(r) submittal material provided herein concludes that BCCS employs Best Technology
Available (BTA) for impingement and entrainment reduction with currently installed closed-cycle
cooling as described below and, as such, no further impingement or entrainment controls are
warranted.
Impingement BTA
The final Rule, at §125.94(c), requires existing facilities to employ one of seven impingement BTA
alternatives'. BCCS is compliant for impingement because it employs two of these alternatives, any one
of which would be wholly compliant for impingement:
• Primary impingement BTA—Closed-cycle cooling with a mechanical draft cooling tower is utilized
to provide makeup water which is consistent with a closed-cycle recirculating system (CCRS)
defined at §125.92(c) and meets the BTA Standards for Impingement Mortality at§125.94(c)(1).
• Secondary impingement BTA — Cooling tower makeup water intake structure employing
cylindrical wedgewire screens with 3.2 mm (0.125") slots designed to have a maximum design
through-slot velocity of less than 0.5 fps; thus meeting the BTA Standards for Impingement
Mortality at§125.94(c)(2).
Overall, impingement at the facility is likely to be very low due to the combination of low makeup flows
to the cooling tower and makeup intake structure low(<_0.25 fps) design through-slot velocity. There are
no known federal or state listed species or designated critical habitats within the source waterbody
(Yadkin River) in the vicinity of the BCCS. As a result, potential adverse impacts due to impingement are
not expected to occur.
'Or under specific circumstances one of nine alternatives,which includes§125.94(c)(11)and(12) in addition to
§125.94(c)(1)-(7).
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316(b)Compliance Submittal
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BUCK COMBINED CYCLE STATION
Entrainment BTA
The Rule does not prescribe BTA for entrainment; however, requires it to be determined on a site-specific
basis. This submittal demonstrates that BCCS meets BTA for entrainment based on the following:
• BCCS uses closed-cycle cooling,which minimizes entrainment through flow reduction. During the
2017-2021 period, BCCS had an average withdrawal of 3.09 million gallons per day(MGD) which
is substantially less than the 125 MGD value of concern technically justified by the Rule. The flow
reduction achieved with consideration of the high-efficiency combined cycle facility, is calculated
to be 97.3% as compared to an equivalent once-through cooling (OTC) facility based on design
flow and 365 days per year operation. Using actual average Yadkin River makeupwithdrawal,the
g
equivalent flow reduction is calculated at 98.9% when compared to an equivalent OTC steam
electric facility. In addition, the average flow is reduced 71.4 percent from the design ultimate
potential flow of 10.8 MGD.
• Statements made by the United States Environmental Protection Agency (EPA) in the preamble
to the Rule support this conclusion:
"Although this rule leaves the BTA entrainment determination to the Director,
with the possible BTA decisions ranging from no additional controls to closed-cycle
recirculating systems plus additional controls as warranted, EPA expects that the
Director, in the site-specific permitting proceeding, will determine that facilities
with properly operated closed-cycle recirculating systems do not require
additional entrainment reduction control measures. "2
This conclusion is further reiterated in the Response to Public Comments document, where EPA
states:
"EPA has made it clear that a facility that uses a closed-cycle recirculating
system, as defined in the rule, would meet the rule requirements for
impingement mortality at§125.94(c)(1). This rule language specifically identifies
closed-cycle as a compliance alternative for the [impingement mortality]
performance standards. EPA expects the Director would conclude that such a
facility would not be subject to additional entrainment controls to meet BTA."3
• The final Rule for new facilities published in the Federal Register on December 18, 2001 which
had an effective date of January 17, 2002, does prescribe BTA for entrainment", which BCCS
meets. Regulations are more stringent for new facilities than for existing facilities. By virtue of
meeting the most stringent entrainment BTA criteria (i.e., applicable to new facilities), BCCS is
compliant for entrainment BTA under the final Rule for existing facilities.
2 79 Fed. Reg. 48344(15 August 2014)
3 Response to Comments, Essay 14,p.62.
BTA for entrainment under the new facilities rule at 40 CFR §125.84(b) requires facilities with design intake flow
equal to or greater than 10 MGD,and under Track 1,to employ closed-cycle recirculating cooling as well.
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316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
Potential impacts to fish and shellfish populations due to entrainment are also extremely unlikely due to:
• The use of closed cycle cooling via mechanical draft cooling towers;
• Low actual and design water withdrawals; and
• The operation and configuration of the intake which features cylindrical wedgewire screens with
3.2 mm slots, screen orientation parallel to the Yadkin River flow, screen submergence at least
ten feet below the river elevation, and design through-slot velocity of 0.25 fps. The calculated
through screen velocity (TSV) for the design intake flow (DIF) case is 0.14 fps and under actual
intake flow (AIF) conditions is 0.06 fps.
Based on the above facts, entrainment is reduced to the maximum extent warranted and additional
control measures are not warranted nor necessary for the BCCS.
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316(b)Compliance Submittal '
BUCK COMBINED CYCLE STATION
1 Introduction
Section 316(b)was enacted under the 1972 CWA,which also introduced the NPDES permit program.
Certain facilities with NPDES permits are subject to§316(b) requirements,which require the location,
design,construction, and capacity of the facility's cooling water intake structure(CWIS)5 to reflect BTA
for minimizing potential adverse environmental impacts.
On August 15, 2014, regulations implementing§316(b)of the CWA for existing facilities(Rule) were
published in the Federal Register with an effective date of October 14, 2014.The Rule applies to existing
facilities that withdraw more than 2 MGD from waters of the United States, use at least 25 percent of
that water exclusively for cooling purposes,and have or require an NPDES permit.
Facilities subject to the Rule are required to develop and submit technical material that will be used by
the NPDES Director(Director)to make a Best Technology Available (BTA) determination for the facility.
The actual intake flow(AIF)6 and design intake flow(DIF)' at a facility determines which submittals will
be required.As shown in Table 1-1,facilities with an AIF of 125 MGD or less have fewer application
submittal requirements and will generally be required to select from the impingement compliance
options contained in the final Rule. Facilities with an AIF in excess of 125 MGD are required to address
both impingement and entrainment,and provide specific entrainment studies, which may involve
extensive field studies and the analysis of alternative methods to reduce entrainment (§122.21(r)(9)-
(13)).
The §316(b)compliance schedule under the Rule is dependent on the facility's NPDES permit renewal
date. Facilities are to submit their§316(b) application material to the Director with their next permit
renewal application unless that permit renewal application is due prior to July 14, 2018, in which case an
alternate schedule may be requested.
5 CWIS is defined as the total physical structure and any associated constructed waterways used to withdraw
cooling water from Waters of the United States.The CWIS extends from the point at which water is first
withdrawn from waters of the United States up to,and including,the intake pumps.
6 AIF is defined as the average volume of water withdrawn on an annual basis by the cooling intake structure over
the past 3 years initially and past 5 years after Oct. 14,2019.The calculation of AIF includes days of zero flow.AIF
does not include flows associated with emergency and fire suppression capacity.
'DIF is defined as the value assigned during the CWIS design to the maximum instantaneous rate of flow of water
the CWIS is capable of withdrawing from a source waterbody.The facility's DIF may be adjusted to reflect
permanent changes to the maximum capabilities of the cooling water intake system to withdraw cooling water,
including pumps permanently removed from service,flow limit devices,and physical limitations of the piping. DIF
does not include values associated with emergency and fire suppression capacity or redundant pumps(i.e., back-
up pumps).
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t + 316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
Table 1-1.Facility and Flow Attributes and Permit Application Requirements.
Existing facility with DIF greater than 2
MGD and AIF greater than 125 MGD. §122.21(r)(2)-(13)
Existing facility with DIF greater than 2
MGD and AIF less than 125 MGD. §122.21(r)(2) (8)
Existing facility with DIF of 2 MGD or
less,or less than 25 percent of AIF Director Best Professional Judgment
used for cooling purposes.
New units at existing facility. §122.21(r)(2), (3), (5), (8), and (14) and applicable
paragraphs (r)(4), (6),and(7) of§122.21(r)
Duke Energy Carolinas, LLC's (Duke Energy) BCCS is subject to the existing facility rule and, based on its
current configuration and operation (i.e.,the facility has a DIF greater than 2 MGD and an AIF of less
than 125 MGD), Duke Energy is required to develop and submit each of the §122.21(r)(2)-(8)submittal
requirements (Table 1-2)with its next permit renewal application in accordance with the facility NPDES
operating permit and the Rule's technical and schedule requirements.Appendix A provides a checklist
summary of the specific requirements under each of the §122.21(r)(2)-(8) submittal requirements and
how each is addressed in this report or why it is not applicable to BCCS.
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316(b)Compliance Submittal i t
BUCK COMBINED CYCLE STATION
Table 1-2.Summary of§316(b)Rule for Existing Facilities Submittal Requirements for§122.21 r 2 - 8 .
(2) Source Water Physical Data Characterization of the source waterbody including
intake area of influence.
(3) Cooling Water Intake Structure Data Characterization of the cooling water intake system;
includes drawings and narrative; description of
operation;water balance.
(4) Source Water Baseline Biological Characterization of the biological community in the
Characterization Data vicinity of the intake; life history summaries;
susceptibility to impingement and entrainment;
existing data; identification of missing data;
threatened and endangered species and designated
critical habitat summary for action area;
identification of fragile fish and shellfish species list
(<30 percent impingement survival).
(5) Cooling Water System Data Narrative description of cooling water system and
intake structure; proportion of design flow used;
water reuse summary; proportion of source
waterbody withdrawn (monthly);seasonal operation
summary; existing impingement mortality and
entrainment reduction measures;flow/megawatts
(MW) efficiency.
(6) Chosen Method of Compliance with Provides facility's proposed approach to meet the
Impingement Mortality Standard impingement mortality requirement(chosen from
seven available options); provides detailed study
plan for monitoring compliance, if required by
selected compliance option;addresses entrapment
where required.
(7) Entrainment Performance Studies Provides summary of relevant entrainment studies
(latent mortality,technology efficacy);can be from
the facility or elsewhere with justification; studies
should not be more than 10 years old without
justification; new studies are not required.
(8) Operational Status Provides operational status for each unit;age and
capacity utilization for the past 5 years; upgrades
within last 15 years; uprates and Nuclear Regulatory
Committee relicensing status for nuclear facilities;
decommissioning and replacement plans; current
and future operation as it relates to actual and
design intake flow.
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316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
2 Source Water Physical Data [§122.21(r)(2)]
The information required to be submitted per 40 Code of Federal Regulations (CFR) §122.21(r)(2),
Source Water Physical Data, is as follows:
(i) A narrative description and scaled drawings showing the physical configuration of all source
water bodies used by your facility, including areal dimensions, depths, salinity and temperature regimes,
and other documentation that supports your determination of the waterbody type where each cooling
water intake structure is located;
(ii) Identification and characterization of the source waterbody's hydrological and
geomorphological features, as well as the methods you used to conduct any physical studies to
determine your intake's area of influence within the waterbody and the results of such studies;
(iii) Locational maps; and,
(iv) For new offshore oil and gas facilities that are not fixed facilities, a narrative description and/or
locational maps providing information on predicted locations within the waterbody during the permit
term in sufficient detail for the Director to determine the appropriateness of additional impingement
requirements under§125.134(b)(4).
Each of these requirements is described in the following subsections.
2.1 Description of Source Waterbody [§122.21(r)(2)(i)]
The MWIS at BCCS withdraws raw water for cooling purposes from an existing shoreline structure on the
south side of the Yadkin River,the source waterbody,just as it enters High Rock Lake.The Yadkin River is
part of the Yadkin-Pee Dee River basin, which is situated in the central portion of North Carolina and
originates in the eastern slopes of the Blue Ridge Mountains. From its source,the river flows eastward,
then southward in the Piedmont toward the city of Bermuda Run, NC. The BCCS is located in the middle
portion of the Yadkin-Pee Dee River basin in Rowan County,just to the east of Salisbury, NC(Figure 2 1).
High Rock Lake, impounded in 1927, is the largest reservoir on the Yadkin River, with a surface area of
6,429 ha (15,886 acres). At the inflow of the river into High Rock Lake,the Yadkin-Pee Dee River Basin
comprises a drainage area of 8,961 km2 (3,459 mi2) (Weiss et al. 1981). Full pool elevation for the
reservoir is listed as 190.2 m msl (624 ft)with a mean depth of 5.2 m (17 ft) and a maximum depth of 19
m (62 ft) in the forebay of the dam (Tetra Tech, Inc. 2004).
Based on a 2009 assessment, approximately 57% of the watershed in the region around BCSS was
forested,with 27%agricultural and the remaining 13%developed (Homer 2004 as cited in EEP 2009).
According to this same report, it was estimated at the time that between years 2006 and 2030, human
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316(b)Compliance Submittal 4
BUCK COMBINED CYCLE STATION
populations in this portion of the drainage basin would increase from 2.7 million to more than 3.9
million. Such increases in development have occurred at an accelerated pace, and the resulting drainage
from urban centers, suburban development, and agricultural usage, coupled with the highly erodible
soils within the basin, currently provide large quantities of sediment for transport in the Yadkin River.
2.2 Characterization of Source Waterbody [§122.21(r)(2)(ii)]
2.2.1 Geomorphology
The BCCS is situated within the Southern Outer Piedmont ecoregion,a northeast to southwest trending
zone of modest relief, irregular plains,and rolling hills.The site is underlain by metamorphic,
sedimentary, and intrusive igneous rocks.A thick saprolite layer and red, clayey subsoils typically overlie
gneiss, schist, and granite bedrock(Griffith et al. 2002). Elevations in the vicinity of the BCCS vary from
650 to 700 ft msl.The only current and foreseeable use for groundwater in the project vicinity is for
domestic water supply for residential properties immediately surrounding the site.
2.2.2 Hydrology
The Yadkin River in North Carolina drains approximates 7,213-square miles(mi2) of mostly forested and
agriculture lands (NCDEQ 2008).About half of this drainage area occurs at the point where the river
passes BCCS, which incorporates the drainage area of the mainstem Yadkin River and South Yadkin
River, whose confluence with the Yadkin River occurs approximately five miles upstream from the BCCS.
This is measured at the nearest gaging station (U.S. Geological Survey [USGS] Yadkin River at Yadkin
College Gage 02151500) located approximately fifteen miles upstream from BCCS, as well as the South
Yadkin River,as measured at the USGS South Yadkin River Gage, near Mocksville, NC(02118000). Mean
annual flow(MAF) measured at these gages during the 2010 to 2020 period is 3,397 cfs and 395 cfs,
respectively.As the river passes the BCCS MWIS, it transitions into the headwaters of High Rock Lake.
The river then flows southeast through several reservoirs, eventually becoming the Pee Dee River
downstream from the Tillery Hydroelectric Development near Norwood, NC.
As discussed below and for the purposes of this report, data collected since 2010 are primarily used to
describe the source waterbody characterization. MAF over this period ranged from 1,960 cfs in 2015 to
5,562 cfs in 2019 in the mainstem Yadkin River(Table 2-1). Mean monthly flow during this time ranged
from 1,050 in November 2016 to 10,500 in November 2020(Table 2-2). Flows from the South Yadkin
River, on average, represent 12%of the MAF.
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t ► 316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
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�, x-� i;
,1. �`\ 11
-1,„,,
t _ _
i \
, ,
Tii
d..,4,....
Figure 2-1. Map Showing the BCCS MWIS in the Yadkin River Basin.
9

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
Table 2-1. Mean annual flow(MAF)of the Yadkin River and South Yadkin River since 2010,as measured at the
USGS Yadkin River at Yadkin College Gage(02116500)and USGS South Yadkin River Gage,near Mocksville,NC
(02118000)since 2010.
Year Yadkin River MAF South Yadkin River MAF
(cfs) (cfs)
2010 3,486 485
2011 2,302 239
2012 2,621 216
2013 4,112 407
2014 3,079 362
2015 1,960 232
2016 3,663 425
2017 2,451 254
2018 3,271 371
2019 5,562 698
2020 4,858 655
Table 2-2.Yadkin River mean monthly flow(cfs)at the USGS Yadkin River Gage at Yadkin College(02116500)
since 2010.
Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2010 6,442 6,099 4,743 3,431 2,844 2,126 1,716 2,037 1,321 2,149 1,517 2,594
2011 1,625 1,728 4,850 3,543 3,010 1,877 1,708 1,286 1,659 1,351 2,151 4,204
2012 2,722 2,253 3,327 2,868 4,820 2,051 1,823 1,625 2,189 1,705 1,227 1,935
2013 6,635 4,248 3,595 3,717 4,887 4,710 9,349 4,440 2,778 2,273 2,632 4,916
2014 4,453 3,813 3,599 4,045 3,183 2,225 1,643 2,455 1,730 1,721 1,991 1,955
2015 2,587 2,118 2,486 3,918 1,724 1,489 1,234 1,200 1,131 3,391 5,034 6,324
2016 4,605 6,639 3,235 2,761 4,241 2,042 1,858 2,706 1,196 1,357 1,050 1,534
2017 2,436 1,388 1,389 6,509 6,105 2,851 1,670 1,598 1,491 2,164 1,751 1,429
2018 1,870 4,657 2,946 4,755 5,156 3,207 2,078 4,534 4,882 6,818 6,017 9,215
2019 7,585 8,256 5,425 5,916 3,985 6,856 3,097 2,285 1,491 2,111 2,945 4,111
2020 4,768 9,561 3,658 4,894 8,810 4,621 3,016 6,306 3,692 6,645 10,150 6,499
10

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
Table 2-3.Mean monthly flow(cfs)at the USGS South Yadkin River Gage,near Mocksville,NC Gage(02118000)
since 2010.
Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2010 924.6 978.1 546 440.7 471.4 255.3 193.6 236.2 165.2 349.5 218.9 283.5
2011 222.4 250.3 543.4 295.7 243.3 138.9 133.2 79.8 109.1 110.7 187.8 314.8
2012 252.6 223.1 295.4 200.4 545.3 152.8 102.2 85.4 119.5 108.8 97.1 187.3
2013 587.2 410 306.1 350.4 490.4 686.9 969.1 419.9 262.8 210.3 308.6 617.2
2014 577.5 460.8 530.8 513.9 320.8 229.5 155.8 247.9 170.9 173.6 245.4 230.9
2015 299.5 244.4 362 595.1 190.5 146.6 121.9 100.7 81.1 362.8 760.1 871.9
2016 551.2 674.5 344.6 289.3 550.1 211.9 212 171.5 104.5 112.7 110.8 143.9
2017 322.4 177.5 185.9 802.4 418.4 319.6 160.2 143.6 159.4 186.4 169.2 160.5
2018 188.8 542.5 329.8 627.6 565 246.9 170.3 695.8 593.9 910.6 1,070 1,398
2019 873.4 1,126 605.9 710.8 392.5 655.6 289 241.8 140.1 225.5 328 594
2020 698.1 1,688 502.1 545 1,161 526.8 289.7 801.1 547.8 916.5 1,608 989.1
2.2.3 Water Quality
Historically,water quality in the upper Yadkin River and High Rock Lake has been substantially impacted
by both sedimentation and nutrient enrichment(NCDENR 2007). The river near BCCS is influenced by
heavily nutrient-enriched tributaries with inputs from upstream agriculturally derived non-point sources
and urban centers such as Statesville,Salisbury, and Winston-Salem, NC.
Duke Energy collects water quality data as part of an ongoing environmental monitoring program on the
Yadkin River.The most recent data collection occurred in the first quarter of 2021 at a location just
upstream from BCCS,which is representative of intake conditions(Figure 2-2). The conventional Duke
Energy sample location number associated with the sample area is provided in Figure 2-2 for reference
to previously submitted reports. Four year(2017-2020) means and ranges of certain water quality
parameters from these sites are provided in Table 2-2. In situ water temperature,dissolved oxygen (DO),
conductivity, and pH data were measured from the water surface using a multi-parameter data sonde
(e.g. Hydrolab®).Water chemistry samples were collected with bottles and returned to the laboratory
for analysis.
Based on these data,water quality in proximity to the BCCS MWIS is representative of a Piedmont river
in the Carolinas (NCEEP 2003). Elevated metal concentrations, in particular iron, most often occur at
higher flows and are typically associated primarily with the particulate fraction of samples. Data
collected during this time indicated that the DO water-quality standards(DO minimum of 4.0 mg/L as an
instantaneous value; NCDENR 2007)were consistently met. Likewise, pH met the State standard of 6 to
9 S.U. Nutrient concentrations and certain physical parameters like turbidity and conductivity were
relatively high, as noted above as being historically characteristic of the Yadkin River at this location.
Table 2-2.Mean(range)concentration for select water quality parameters documented in the Yadkin River near
the BCCS MWIS from 2017-2020.
Parameter Location B
Temperature(°C) 15.5(6.5-27.0)
Dissolved Oxygen(mg/L) 8.1(6.5-11.0)
Conductivity(µS/cm) 73(63-123)
11

I
316(b)Compliance Submittal '
BUCK COMBINED CYCLE STATION
Parameter Location B
pH(SU) 6.3(6.8-7.3)
Turbidity(NTU) 27(4-95)
Nutrients(µg/L)
Ammonia-N 47(30-75)
Nitrate+Nitrite-N 957(702-1,200)
Total Phosphorus 121(57-222)
Ions(mg/L)
Calcium 5.3 (0.25-7.4)
Chloride 5.4(3.5-9.2)
Magnesium 2.0(0.05-2.5)
Sodium 5.3(3.5-10.0)
Sulfate 4.8(3.7-7.7)
Metals
Aluminum,Total (mg/L) 0.84(0.006-10.0)
Iron,Total(µg/L) 676(0.66-2,070)
Manganese,Total(mg/L) 32.3(0.03-131)
12

f
I • 316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
1
fi
1
A
(433.1&433 2) "-_-
- - -
B
(432.1 &432.2)
,✓ D
c C (430.6&430.7) -
a
t, `� (430.1 &430.2) ----
r
m
/ fi; ,
,1 � Buck Combined Cycle Station
.. I f y
N
' ' ' A )
. ' ,:,. ,...„ i
,.
o 0, ,,,
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r1 i.r r n- .• r 1� -.
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s.p, ._. ..u11.us,,,..„ Ir. .1:4'.G r otltr'q i . .
Figure 2-2.Duke Energy biological and water quality(Locations B and C)sampling locations in proximity to the
BCCS.
13

316(b)Compliance Submittal •
BUCK COMBINED CYCLE STATION
2.3 Locational Maps [§ 122.21(r)(2)(ii)
An aerial photograph of the BCCS and its environs is provided on Figure 2-2 (Section 2.2.3).
14

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
3 Cooling Water Intake Structure Data [§
122.21(r)(3)]
The information required to be submitted per 40 CFR §122.21(r)(3), Cooling Water Intake Structure
Data, is outlined as follows:
(i) A narrative description of the configuration of each of the cooling water intake
structures and where it is located in the waterbody and in the water column;
(ii) Latitude and longitude in degrees, minutes, and seconds for each of the cooling water
intake structures;
(iii) A narrative description of the operation of each of the cooling water intake structures,
including design intake flows, daily hours of operation, number of days of the year in operation
and seasonal changes, if applicable;
(iv) A flow distribution and water balance diagram that includes all sources of water to the
facility, recirculating flows, and discharges; and
(v) Engineering drawings of the cooling water intake structure.
Each of these requirements is described in the following subsections.
3.1 Description of MWIS Configuration [§122.21(r)(3)(i)]
Cooling tower makeup water for BCCS is withdrawn from the Yadkin River via the existing BCCS MWIS.
The former Buck Steam Station (BSS) was retired in 2013 and a new CWIS (MWIS)was constructed to
serve the BCCS. The new BCCS MWIS features three 30-inch-diameter wedgewire screen units with the
screen face oriented parallel to the direction of the river flow. Pumped raw water is routed to a clarifier
for treatment prior to use by the station. Approximately 95 percent of the treated water from the
clarifier is used for cooling tower makeup water(see Figure 3-1 for the water balance diagram). The
remaining filtered water is stored in the fire water/service water tank for use as fire protection water,
makeup water for the combined cycle unit heat recovery steam generator(HRSG), and/or various other
plant functions.
The raw water intake system at the BCCS consists of three wedgewire screens,three submersible intake
pumps (50 percent capacity each), and piping necessary to direct the withdrawn water to the BCCS.
Makeup water is withdrawn from Yadkin River via the three submerged, cylindrical wedgewire screens
located along the south bank of the Yadkin River. The wedgewire screen array is located in the flowing
section of the river channel just beyond the end of the intake structure wingwall as shown on Figure 3-2.
The river elevation in this area is approximately 633 feet above mean sea level (ft msl) (AECOM 2017)
and the centerline of the cylindrical wedgewire screens is at 610.40 ft msl. The bottom of the screens is
at 609.15 ft msl, or approximately 7.0 ft above the riverbed. The top of the screens is at 611.65 ft msl,
which is 1.75 ft below the design low level operation of 613.40 ft msl. As a result,the minimum depth
the wedgewire screen array is totally submerged is approximately 1.75 ft at the design low level
elevation. Figure 3-3 provides relevant MWIS elevation data.
15

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
Each wedgewire screen unit is 30 inches in diameter and 101.01 inches in total length with 31 inches in
screen length on either side of a 24-inch-diameter flange. Each screen has a manufacturer design
capacity of 2,500 gallons per minute (gpm) (3.6 MGD)and has 3.2-millimeter(mm)slot openings with
63.78 percent open area (POA). As directed by plant staff,an air sparging system may be operated to
remove any accumulated trash and debris. Figure 3-4 provides the wedgewire screen design details.
The three wedgewire screen units are connected to a manifold where three submersible raw water
intake pumps located within a reinforced concrete intake structure can take suction. The cooling water
piping configuration is shown on Figures 3-2 and 3-3.
Each of the three raw water intake pumps is rated at 3.6 MGD, however,only two pumps are operated
at the same time with one pump remaining as a spare for redundancy. Therefore,the maximum pump
capacity(or DIF) of the raw water intake pumps is 7.2 MGD.
16

1 4 316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
Buck Steam Station and Combined Cycle
Station
NPDES Flow Schematic
February 20161.
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Figure 3-1.BCCS Water Balance Diagram
17

316(b) Compliance Submittal ` `
BUCK COMBINED CYCLE STATION
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Figure 3-2. Plan View of MWIS at the BCCS
18

e ` 316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
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Figure 3-3.Section View of MWIS at the BCCS
19

316(b)Compliance Submittal '
BUCK COMBINED CYCLE STATION
31 OVEPA,1_ova-I .
FIEF
,. . 3100 SCREEN.EMn
1ft135
c o ° 2 . i
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Figure 3-4.Wedgewire Screen Design of BCCS
3.2 Latitude and Longitude of MWIS [§122.21(r)(3)(ii)]
The approximate latitude and longitude(in degrees, minutes, and seconds)of the BCCS MWIS is:
• Latitude:35°42' 50" N
• Longitude:80° 22' 38"W
3.3 Description of MWIS Operation [§122.21(r)(3)(iii)]
Withdrawal from the Yadkin River is dependent on makeup water demand, maximum pump capacity,
and water loss due to evaporation and system losses. Because makeup water demand is directly related
to the operation of generating units and in turn,the cooling water system, BCCS MWIS operation
generally follows a base load pattern.
Operation of the MWIS is nearly continuous with at least one pump withdrawing water from the Yadkin
River. During the 2017-2021 period,the MWIS operated an average of approximately 20.6 hours each
day with one or two pumps withdrawing water.
20

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
3.4 Description of Intake Flows [§122.21(r)(3)(iv)]
Monthly average water withdrawals during the 2017-2021 period are provided in Table 3-1. The average
withdrawal for this period was 3.09 MGD compared to a DIF of 7.2 MGD.
Table 3-1. BCCS MWIS Monthly Total Withdrawals During 2017-2021.
Month 2017 2018 2019 2020 2021
January 87.6 85.0 93.2 0.0 93.9
February 86.2 84.6 9.0.0 67.7 72.5
March 99.7 76.0 3.8 96.4 96.4
April 78.9 109.3 19.8 49.8 77.7
May 104.3 114.3 113.4 93.8 102.3
June 109.6 120.5 109.6 118.7 99.0
July 120.9 132.9 125.2 136.1 132.4
August 118.8 130.6 123.7 121.5 116.9
September 107.4 130.6 113.0 16.1 92.1
October 101.9 106.4 109.2 0.0 107.4
November 96.3 95.8 91.5 83.1 104.7
December 97.5 86.5 86.4 100.2 102.7
Annual 3.3 3.5 3.0 2.4 3.3
Average
Units = MG for monthly total, MGD for annual average
3.5 Engineering Drawings of CWIS [§122.21(r)(3)(v)]
The following engineering drawings of cooling water intake structures are provided in Appendix B:
• Drawing D000846153:T-30 X 24 HC Intake Screen Assembly With 3"ABW Connection
• Drawing BUKOC-PY-P-RW.00.EV-01: Buck Combined Cycle Station Raw Water Supply Pump
Station and Screen Elevation Views
• Drawing BUKOC-SS-S-IS.00.SD-01: Buck Combined Cycle Station Raw Water Supply Intake
Structure Structural Sections and Details
21

•
316(b)Compliance Submittal 1
BUCK COMBINED CYCLE STATION
4 Source Water Baseline Biological Characterization
Data [§122.21(r)(4)]
The information required to be submitted per 40 CFR§122.21(r)(4), Source Water Baseline Biological
Characterization, is outlined as follows:
(i) A list of the data supplied in paragraphs(r)(4)(ii)through (vi)of this section that are not
available and efforts made to identify sources of the data;
(ii) A list of species(or relevant taxa)for all life stages and their relative abundance in the
vicinity of CWIS;
(iii) Identification of the species and life stages that would be most susceptible to impingement
and entrainment;
(iv) Identification and evaluation of the primary period of reproduction, larval recruitment, and
period of peak abundance for relevant taxa;
(v) Data representative of the seasonal and daily activities of biological organisms in the vicinity
of CWIS;
(vi) Identification of all threatened, endangered,and other protected species that might be
susceptible to impingement and entrainment at a cooling water intake structure(s);
(vii) Documentation of any public participation of consultation with Federal or State agencies
undertaken in development of the plan;
(viii) Methods and QA procedures for any field efforts;
(ix) In the case of the owner or operator of an existing facility or new unit at an existing facility,
the Source Water Baseline Biological Characterization Data is the information included in (i)
through (xii);
(x) Identification of protective measures and stabilization activities that have been
implemented, and a description of how these measures and activities affected the baseline
water condition in the vicinity of CWIS;
(xi) List of fragile species as defined at 40 CFR 125.92(m)at the facility; and
(xii) Information submitted to obtain incidental take exemption or authorization for its cooling
water intake structure(s)from the U.S. Fish and Wildlife Service or the National Marine
Fisheries Service.
Each of these requirements is described in the following subsections.
4.1 List of Unavailable Biological Data [§122.21(r)(4)(i)]
The biological data needed to prepare the information required under 40 CFR§122.21(r)(4)are
available. Duke Energy collects biological data as part of a long-term and ongoing environmental
22

316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
monitoring program on the Yadkin River(Duke Power 1994, 2003, 2011).The objective of this ongoing
monitoring program was to assess the fish community with respect to operation of the now demolished
Buck Steam Station and provide an indication of the suitability of approved thermal limits as defined in
the Buck Steam Station NPDES permit(NC0004774). Beginning in 1990,fish community samples were
collected annually in the winter and summer from four sites on the Yadkin River where it transitions into
High Rock Lake near the BCCS(Figure 2-2).As mentioned above, conventional Duke Energy sample
location numbers associated with the sample areas are provided in Figure 2-2 for reference to
previously submitted reports.
Following operational changes from once-through cooling to closed-cycle cooling in 2011, annual
biological monitoring was discontinued, with the last fish community data being collected in January
2012; however, Duke biologists revisited the river in the fall of 2018 and sampled areas A, C and D.
•
4.2 List of Species and Relative Abundance in the vicinity of CWIS
[§122.21(r)(4)(ii)]
Forty-two fish species, representing nine families have been documented in the Yadkin River by Duke
Energy since 2000 (Table 4-1). Numerous cyprinid, catostomid, ictalurid, and centrarchid species are
represented in these collections, which indicate a diverse fish fauna.These species are consistent with
those expected from fish distribution maps of the Yadkin River drainage (Menhinick 1991), and none of
these species are state or federally protected.
Table 4-1.Fish species collected by Duke Energy in the Yadkin River since 2000,and their associated pollution
tolerance,trophic guild,and native origin status.
Scientific Name Common Name 2000- 2018 Tolerance Trophic Origin2
2011 Rating'. Status'
Amiidae Bowfins
Amia calva Bowfin X X Tolerant Piscivore N
Catostomidae Suckers
Carpiodes cyprinus Quillback X Intermediate Omnivore N
Catostomus commersonii White Sucker X Tolerant Omnivore N
Minytrema melanops Spotted Sucker X Intermediate Insectivore N
Moxostoma collapsum Notchlip Redhorse X Intermediate Insectivore N
Moxostoma macrolepidotum Shorthead Redhorse X X Intermediate Insectivore N
Moxostoma n.sp. Brassy Jumprock X X Intermediate Insectivore N
Moxostoma pappillosum V-lip Redhorse X Intermediate Insectivore N
Centrarchidae Sunfishes N
Lepomis auritus Redbreast Sunfish X Tolerant Insectivore N
Lepomis cyanellus Green Sunfish X X Tolerant Insectivore I
Lepomis gibbosus Pumpkinseed X X Intermediate Insectivore N
Lepomis gulosus Warmouth X X Intermediate Insectivore N
Lepomis macrochirus Bluegill X X Intermediate Insectivore N
Lepomis microlophus Redear Sunfish X X Intermediate Insectivore N
Lepomis spp. Hybrid Sunfish X Intermediate Insectivore H
Micropterus punctulatus Spotted Bass X X Intermediate Piscivore I
Micropterus salmoides Largemouth Bass X X Intermediate Piscivore N
23

316(b)Compliance Submittal ` 1
BUCK COMBINED CYCLE STATION
Scientific Name Common Name 2000- 2018 Tolerance Trophic Origin'
2011 Rating' Status'
Micropterus salmoides x M. Hybrid Black Bass X Intermediate Piscivore H
punctulatus
Pomoxis annularis White Crappie X X Intermediate Piscivore I
Pomoxis nigromaculatus Black Crappie X X Intermediate Piscivore I
Clupeidae Shad and Herrings
Alosa aestivalis Blueback Herring X Intermediate Insectivore N
Dorosoma cepedianum Gizzard Shad X X Intermediate Omnivore N
Dorosoma petenense Threadfin Shad X X Intermediate Omnivore I
Cyprinidae Minnows and Shiners
Carassius auratus Goldfish X Tolerant Omnivore I
Cyprinella analostana Satinfin Shiner X Tolerant Insectivore N
Cyprinella lutrensis Red Shiner X X Tolerant Insectivore I
Cyprinella nivea Whitefin Shiner X Intermediate Insectivore N
Cyprinella pyrrhomelas Fieryblack Shiner X Intolerant Insectivore N
Cyprinus carpio Common Carp X X Tolerant Omnivore I
Cyprinus carpio x Carassius Hybrid Common Carp X Tolerant Omnivore H
auratus
Hybognathus regius Eastern Silvery X X Intermediate Herbivore N
Minnow
Nocomis leptocephalus Bluehead Chub X Intermediate Omnivore N
Notemigonus crysoleucas Golden Shiner X X Tolerant Omnivore I
Notropis hudsonius Spottail Shiner X Intermediate Omnivore N
Icatluridae Catfishes
Ameiurus catus White Catfish X Tolerant Omnivore N
Ameiurus nebulosus Brown Bullhead X Tolerant Omnivore N
Ictalurus punctatus Channel Catfish X X Intermediate Omnivore I
Pylodictis olivaris Flathead Catfish X X Intermediate Piscivore I
Lepisosteidae Gars
Lepisosteus osseus Longnose Gar X Tolerant Piscivore N
Moronidae Temperate Basses
Morone americana White Perch X X Intermediate Piscivore N
Morone chrysops White Bass X X Intermediate Piscivore I
Morone saxatilis Striped Bass X Intermediate Piscivore N
Morone saxatilis x M. Hybrid Striped Bass X Intermediate Piscivore H
chrysops
Percidae Perches
Etheostoma olmstedi Tessellated Darter X Intermediate Insectivore I
Perca flavescens Yellow Perch X X Intermediate Piscivore N
Poeciliidae Livebearers
Gambusia holbrooki Eastern Mosquitofish X X Tolerant Insectivore I
1 Pollution tolerance and trophic guild information from NCDENR(2013);2 Origin(I=Introduced,N=Native,H=Hybrid)
status to Yadkin River basin taken from Rohde et.al(2009).
24

316(b)Compliance Submittal
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4.2.1 Electrofishing
From 2000-2011, boat-mounted electrofishing occurred in the winter and summer along one-hundred-
meter shoreline segments on each side of the river at locations A—D. Electrofishing effort in seconds
was also recorded for each segment. All netted fish were identified, measured (total length in mm), and
returned to the river. Biomass data were not recorded.As much as practical, electrofishing was
conducted during periods of relatively low river flow to ensure efficient sampling and to minimize
variability due to high water conditions. Abundance, or catch-per-unit-effort(CPUE) of species was
reported as fish/hour. Similar methodology was used in 2018 at locations A, C and D. For the purposes
of this report and to describe the fishery in proximity to the MWIS, data from all sites were combined
for the respective sample periods.
Electrofishing surveys during both winter and summer 2000-2011,from all locations combined resulted
in the collection of 42 species and three hybrid complexes (Table 4-2).Twenty-three species were
collected during 2018. Bluegill (45%) were the were the most numerous species collected from 2000-
2011,while Gizzard Shad (45%)were the most numerous in 2018, primarily due to the collection of a
large school of juveniles. Bluegill (17%) and Red Shiner(15%)were also collected in relatively high
numbers in 2018.The abundance of all fish collected in proximity to the BCCS demonstrates no
discernable trend during the 2000-2018 surveys,with the 2018 CPUE being similar to several other years
since 2000(Figure 4-1).
Electrofishing surveys were conducted at mean water temperatures approximating 25°C for both
sampling periods(Table 4-3).These values were within ranges that would support fish assemblages
typical of a piedmont river.There were no pH data collected from 2000 to 2011.
Table 4-2.Fish species and numbers collected during electrofishing from all zones combined in the Yadkin River.
2000-2010 2018
Common Name
Winter Summer Fall
Bowfins
Bowfin 1 0 3
Suckers
Quillback 0 2 0
White Sucker 2 0 0
Spotted Sucker 3 0 0
Notchlip Redhorse 4 2 0
Shorthead Redhorse 2 2 1
Brassy Jumprock 1 0 1
V-lip Redhorse 1 0 0
Sunfishes
Redbreast Sunfish 50 62 0
Green Sunfish 174 281 3
Pumpkinseed 785 453 8
Warmouth 32 13 1
Bluegill 3,056 3,150 96
Redear Sunfish 80 75 3
25

316(b)Compliance Submittal `
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2000-2010 2018
Common Name
Winter Summer Fall
Hybrid Sunfish 5 18 0
Spotted Bass 45 56 1
Largemouth Bass 198 528 1
Hybrid Black Bass 1 0 0
White Crappie 44 48 3
Black Crappie 280 141 12
Shad and Herrings
Blueback Herring 0 8 0
Gizzard Shad 538 518 245
Threadfin Shad 211 110 5
Minnows and Shiners
Goldfish 108 22 0
Satinfin Shiner 261 12 0
Red Shiner 638 680 88
Fieryblack Shiner 1 0 0
Common Carp 77 168 20
Hybrid Common Carp 1 5 0
Eastern Silvery Minnow 7 59 15
Bluehead Chub 4 0 0
Golden Shiner 13 75 2
Spottail Shiner 1 7 0
Whitefin Shiner 10 0 0
Catfishes
White Catfish 0 4 0
Brown Bullhead 0 16 0
Channel Catfish 9 141 17
Flathead Catfish 4 15 1
Gars
Longnose Gar 11 30 0
Temperate Basses
White Perch 356 155 11
White Bass 6 8 4
Striped Bass 1 0 0
Hybrid Striped Bass 1 0 0
Perches
Tessellated Darter 7 4 0
Yellow Perch 9 3 2
Livebearers
Eastern Mosquitofish 23 22 1
Total 7,061 6,893 544
No.Taxa 38 33 23
26

316(b)Compliance Submittal
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1200
f 2000-2012 Winter
O 2000-2011 Summer
1000 - v 2018 Fall
0
800 -
O
O
ci 600 -
c O 0
co
0
- 400 - 0
0 0 • -
• O
200 -
0
1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020
Figure 4-1.Total abundance(CPUE)by number of all fish species collected within all zones from electrofishing in
the Yadkin River during winter 2000-2012,summer 2000-2011,and fall 2018.
Table 4-3.Mean(and range)of water quality parameters for all sites combined during electrofishing in 2000-
2012 and 2018.
2000-2012 2000-2012 2018
Parameter
Winter Summer Fall
Temperature(CC) 8.0(0.4-15.4) 28.1 (22.7-36.0) 18.3 (17.7-19.3)
Dissolved Oxygen(mg/L) 11.9(9.7-14.3) 6.6(5.3-9.1) 7.9(5.3-8.6)
Conductivity(µS/cm) 88(62-109) 102 (57-137) 70(64-83)
pH - - 6.7(6.4-6.8)
Four numerically dominant fish species (Largemouth Bass, Black Crappie, Redfin Shiner, and Channel
Catfish) were assessed further for certain metrics. Length frequency analyses indicated multiple age-
classes of all four species during electrofishing (Figure 4-2). Collections of Largemouth Bass are primarily
represented by younger individuals, while two distinct age classes are evident in Black Crappie
collections.Trends in CPUE over time suggest similar catch rates from 2011 to 2018 for Black Crappie
and Red Shiner, while Largemouth Bass catch rates generally declined, likely due to increased
competition by the introduced Spotted (Alabama) Bass (Figure 4-3). Summer Channel Catfish catch rates
27

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
also declined since 2000; however,this species is not as susceptible to being collected using
electrofishing as the other species.
4.3 Primary Growth Period
Fish are cold blooded,thus primary growth occurs when water temperatures are 10°C or above.The
conventional view on seasonal variation in fish growth in North America is that growth is fastest in the
spring and early summer,slows in the late summer and fall, and virtually stops in the winter(Gebhart
and Summerfelt 1978).The majority of fishes will have their highest densities shortly after the hatch
occurs when larvae are concentrated,and natural mortality has not yet reduced numbers. Feeding
competition is especially important during late spring through early summer when the bulk of fish are in
their early life stages. During this time,they are more susceptible to starvation (May 1974).This is a
critical stage in development,where larval fish have a short time period to initiate exogenous feeding
before starving(Ehrlich 1974; Miller et al. 1988).
4.3.1 Reproduction and Recruitment
Similar to other southeastern rivers, reproduction strategies of fish species present in the Yadkin River
vary and include broadcast spawners, nest builders, mound builders, and cavity nesters. Nest builders
usually exhibit parental care until hatching and the swim-up stage,whereas broadcast spawners do not
construct nests and provide no parental care. Eggs for both types of spawners are usually demersal
and/or adhesive or may initially be adhesive prior to losing this characteristic. Nest-building species with
adhesive eggs are less susceptible to entrainment.
Fish spawning is typically triggered when water temperatures reach the species-specific temperature
threshold (Etnier and Starnes 1993). Fish reproduction has the potential to produce high yields;
however, mortality rates are typically higher compared to other organisms.Additionally,the majority of
fish spawn only once per year, regardless of prior success.The number of eggs a female produces
(fecundity)can vary depending on the life history of the species and individual size.Species-specific
spawning information is summarized in Table 4-4.
28

316(b)Compliance Submittal
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25
I♦ LARGE MOUTH BASS
n=728
20
15
10
5
0
0 50 100 150 200 250 300 350 400 450 500 550
IC
14
MI BLACK CRAPPIE
12 n=433
10
O 8
4 + 0
4
O
2
0
O 15 45 75 105 135 165 195 225 255 285 315 345
a + 40
Q1 RED SHINER
U 3C n= 1.318
Sv
20
10
0
0 10 70 40 40 40 NI 70 170 90 100
18
14
12
CHANNEL CATFISH
10 n=173
8
4
2
0
25 75 125 175 225 275 325 375 425 475 525 575 625
TL (mm)
Figure 4-2. Length-frequency of four numerically dominant species collected in the Yadkin River from all sites
sampled in Winter 2000-2012,Summer 2000-2011,and Fall 2018 combined.
29

316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
160
t 2000201 Wl 2 nmm
140- 0 2000-2011 subr
er
• 2018 Fall
120-
100- o
80-
0
60-
40- ° O O
O
20- O
O
0 •
1060 2060 211112 21114 210e1 2006 2010 7017 21114 2018 7018 70211
160
—41—2000-2012 Winter
140- O 2000-2011 Summer
♦ 2018 Fell
rL 120- 8
1
100
N BOLi— 60
W 40
U °
20- O °
o
0
•
19911 218a1 MO 20114 21W1 2Ma 2010 9012 2n11 2018 Min 911911
300
t 2000-2012 Winter
O 2000-2011 Summer
250- 0 ♦ 2018 Fell
200
150- 0
100
0
50 •
0
o
0 ° ° 0
loon 'non 2m2 7nna 71110 211M 21110 2012 91114 20111 2016 2020
25
0
f 2000-2012 Wlmn
O 20002011 Summer
20 O • 2018 Fell
0 CI
15
0
0 •
0
10 0
0
0 0
5
0 0
0 - -——- • • • •
1998 2000 2002 2004 2006 2008 2010 2012 2014 2016 2018 2020
Year
Figure 4-3.Abundance(fish/hr)of four numerically dominant species collected in the Yadkin River from all sites
sampled in Winter 2000-2012,Summer 2000-2011,and Fall 2018 combined.
30

316(b)Compliance Submittal
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Table 4-4. Habitat,diet,and spawning characteristics of select species present in the Yadkin River near the BCCS.
Species General Habitat Diet Spawning Period and Nest Structure Egg Type and References
Habitat Fecundity
CATOSTOMIDAE
Redhorse suckers Deeper pools,streams Aquatic insects, Spring and Summer Broadcast Adhesive; Rohde et al. (2009)
(Moxostoma spp.) and rivers crayfish, Water temperature: spawners 100,000 plus
microcrustaceans 60-75°F; migrations to eggs
rocky, shallow riffles
and runs
CLUPEIDAE
Gizzard Shad Lakes, ponds, pools, Filter feeder: Spring and Summer Broadcast Adhesive; Williamson and Nelson
and backwaters of low- algae, micro- Water temperature: spawners 300,000 on (1985); Etnier,and
gradient rivers organisms 61°F; In schools; at average Starnes(1993)
the
surface over
submerged rocks or
logs
CENTRARCHIDAE
Black Crappie Vegetated backwater Aquatic insects, Spring Water Circular beds 0.6- Demersal; Hammers(2011);
areas in streams, small fishes temperature:60- 1.3 ft in diameter 40,000 to Bridges(2017); Dubuc
rivers, ponds,and 68°F;Shallow(3-8 ft in gravel or soft 130,000 and DeVries(2002);
reservoirs; in littoral deep),calm water lake bottoms near NCDENR(2006)
and pelagic zones near vegetation structure.
Bluegill Creeks, rivers, Aquatic insects, Spring and Summer Shallow,circular Adhesive; MDNR(2017);Stone
swamps, lakes, ponds, small fishes, Water Temperature: depressions 2-6 2,000 to (2008); Hammers and
in vegetated areas crayfish 67-80°F;Colonial in. 60,000 1 Bryant(2011)
with cover such as breeder;shallow deep in sand or
woody debris,stumps, waters with gravel
rocks,and undercut firm bottoms
banks
Redbreast Sunfish Pools and backwaters Aquatic insects, Spring and Summer Saucer-shaped Demersal and Rohde et al.(2009);
of streams and rivers small clams,small Water temperature: depressions in Adhesive; up Hendrickson and
with low to moderate fish 65-75°F;Shallow gravel or silt to 14,000 Cohen(2015); Ross
gradient; water on bottoms (2001);Carlander
woody debris,stumps, composed of sand, (1977);Wang and
undercut banks Kernehan. (1979)
31

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
Species General Habitat Diet Spawning Period and Nest Structure Egg Type and References
Habitat Fecundity
gravel,or pebbles
near cover
Redear Sunfish Ponds,lakes Hard Spring and Summer Depressions in Demersal and Rohde et al.(2009);
reservoirs,swamps, invertebrates Water temperature: sand to soft mud Adhesive; Hendrickson and
streams,small rivers; such as snails and 68-70*F;Shallow constructed in 2,000 to Cohen(2015);Auer,
associated with small clams water on firm areas containing 10,000 N.A. 1982;Adams and
vegetation over a mud substrates often in aquatic plants. Kilambi(1979)
or sand bottom locations exposed to
the sun
Largemouth Bass Lakes, reservoirs, Gape-limited; Spring Water Circular beds 2-3 Adhesive; Rohde et al.(2009);
ponds,slow-moving fish,frogs, temperature:60-75"F ft 5,000 to Hendrickson and
rivers, in littoral and crayfish in diameter with 43,000 Cohen(2015); Ross
pelagic zones clean sand or fine (2001);Auer, N.A.
gravel,clear of 1982;
organic debris
and
silt.
CYPRINIDAE
Redfin Shiner Large creeks,medium Surface feeder, Spring to summer; Broadcast Demersal; Ross(2001)
rivers,slow currents zooplankton, shoreline spawners, Multiple
aquatic insects, sometimes over clutches of
some plant sunfish nests 219-887
material
ICTALURIDAE
Channel Catfish Small to large creeks, Fish,crayfish, Spring and Summer Excavations under Demersal Tatarenkov et al.
rivers, reservoirs,and mollusks,aquatic Water temperature: overhangs or logs masses; 1,600- (2006);Wellborn
ponds insects,some 75-85*F;Cavities in 70,000 (2008)
aquatic banks,under logs,or
vegetation in rocks
MORONIDAE
White Perch Rivers and reservoirs Microcrustaceans, Spring and Summer; Over sand and Adhesive; Rohde et al.(2009);
fish Shallow water gravel 20,000- Auer(1982);
150,000 University of Michigan
(2017)
32

316(b)Compliance Submittal
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4.3.2 Period of Peak Abundance for Relevant Taxa
Fish spawning is a direct function of water temperature and most activity is constrained to the spring
and early summer months.As a result, an influx of egg, larval, and juvenile fishes occurs in the Yadkin
River in the spring of each year when water temperatures begin to rise. Based on a review of available
literature, peak abundance for early life stage and juvenile fishes of most species in occurs between
March and June (Table 4-5). Generally, recruitment to the juvenile life stage in North Carolina follows
the peak spawning window and continues until April or May of the succeeding year, depending on the
life history strategy of individual species (Page and Burr 2011).
Table 4-5. Primary period of reproduction for select species present in the Yadkin River(Sources:Ross 2001;
Rohde et al.2009).'
Common
Family Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Catostomidae Redhorse
suckers
Black Crappie
Bluegill
Largemouth
Centrarchidae Bass
Redbreast
Sunfish
,i
Redear Sunfish
Clupeidae Gizzard Shad
Common Carp
Cyprinidae
Redfin Shiner •
L.
Channel
Catfish
Ictaluridae — r
Bullhead
catfishes
Moronidae White Perch
Percidae Darter spp.
'This table illustrates the potential spawning window and potential peak spawning period in the Yadkin River based on a review
of available literature and comparable southeastern rivers.Lighter shade indicates the spawning window and darker shading
indicates the peak spawning period.
4.4 Daily and Seasonal Activities of Organisms in the Vicinity of the
MWIS
The typical habitat preferred by riverine species includes submerged woody debris (roots, logs),
backwaters, rocky riffles, runs, pool habitat, and vegetated areas. Daily migrations, such as longitudinal
migrations for feeding or spawning are typical for fish species that inhabit riverine environments.
Although there are no diadromous fish species in the Yadkin River near BCCS, certain species (e.g.
33

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
Redhorse suckers)will undergo potadromous(i.e., movements within freshwater) migrations to spawn.
Overwintering movements into deeper pool habitats may also occur for several species (Rhode et al.
2009).
4.5 Species and Life Stages Susceptible to Impingement and
Entrainment
4.5.1 Impingement
The BCCS MWIS design,with a design TSV of less than 0.25 fps, is compliant with the impingement BTA
requirements of the Rule. As such,the anticipated likelihood of fish species and vulnerable life stages
susceptible to impingement at the BCCS MWIS is very low.While some species may have the potential
to be entrained, based on the operational parameters of the MWIS(position of the cylindrical
wedgewire screens and low DIF and TSV), interactions with aquatic organisms are expected to be limited
with very low potential for adverse environmental impacts.
Preliminary impingement data were collected at BSS in 2006(unpublished data)while the Phase II
316(b) Rule was effective prior to that Rule's remand.Three sampling events were performed during
operation of the former(now retired)coal-fired units with once-through cooling. The results of these
sampling events are provided strictly for documenting species occurrence in proximity to the existing
MWIS.The study estimated impingement losses at 10,098 fish under the former once-through cooling
operations,with the majority(74%) being Gizzard Shad,a fragile species(Table 4-6).
Table 4-6. Results of preliminary impingement data collected at Buck in 2006 under the Phase II Rule
(unpublished data). [former BSS CWIS and not representative of the current BCCS MWIS]
Common Name/Group Number Number/24-hr Estimate No./Yr
Gizzard Shad 61 20.3 7,421
Unidentified Adult 9 3.0 1,095
Pumpkinseed 7 8.4 852
Channel Catfish 2 2.4 243
Blue Catfish 1 1.2 122
Blueback Herring 1 1.2 122
Perches 1 1.2 122
Redbreast Sunfish 1 1.2 122
4.5.2 Entrainment
Ichthyoplankton (the egg and larval life stage of fishes) exhibit the highest degree of susceptibility to
entrainment based on body size and swimming ability.Therefore, an organism is only susceptible to
entrainment for a small portion of its life cycle. Larger juvenile and adult life stages have the swimming
ability to avoid entrainment. Life history characteristics can influence the vulnerability of a fish species
to entrainment. For example, broadcast spawners with non-adhesive,free-floating eggs can drift with
water currents and may become entrained in a CWIS,while nest-building species with adhesive eggs are
less susceptible to entrainment during early life stages (King et al. 2010).
34

316(b)Compliance Submittal
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The BCCS MWIS design with closed-cycle cooling is compliant with entrainment BTA requirements of the
Rule; however, it could be expected for some de minimis rate of entrainment to occur. Entrainment
sampling has not been performed at BCCS,and there is no comparable site within the same river basin
to use as a surrogate as to what can be expected. Based on the species assemblage in proximity to BCCS
and results from other regional sites, it presumed that the majority of any entrained organisms would
be comprised of Gizzard Shad egg/larvae and some sunfish species.
4.6 Threatened, Endangered, and Other Protected Species
Susceptible to Impingement and Entrainment at the MWIS
The Rule requires the permittee to document the presence of federally listed species and designated
critical habitat in the action area (see 40 CFR 125.98[f]). For the purpose of defining listed species, the
action area is defined as the Yadkin River at a distance two miles upstream and downstream from the
BCCS MWIS.
A desktop review of available resources was performed to develop a list of species with protected,
endangered, or threatened status that might be susceptible to impingement and entrainment at the
BCCS MWIS.The U.S. Fish and Wildlife Service (USFWS) map-based search tool (Information for Planning
and Consultation [IPAC])was used to identify state or federally listed rare,threatened,or endangered
(RTE) aquatic species or critical habitat designations within action area (USFWS 2021).The National
Marine Fisheries Service (NMFS) Essential Fish Habitat(EFH) online tool was reviewed for EFH or habitat
areas of particular concern within the vicinity of BCCS (NMFS 2021).The BCCS MWIS is located in a
freshwater environment, as such, marine and anadromous federally listed species and designated
critical habitat under NMFS jurisdiction were not considered.
No state or federally listed rare,threatened, or endangered (RTE) aquatic species or critical habitat
designations were identified in the IPaC database search. Federal species of concern and candidate
species were omitted from the list (unless they were also state threatened or endangered), as there are
no requirements to address those species under the Rule or Section 7 of the Endangered Species Act
(ESA 1973); however, none are known to occur near the action area regardless.
4.7 Documentation of Consultation with Services
In preparing this response package for compliance with CWA §316(b),there has been neither public
participation, nor coordination undertaken with USEPA, NMFS, or USFWS, collectively known as the
Services.
4.8 Information Submitted to Obtain Incidental Take Exemption or
Authorization from Services
As noted in Section 4.6, no federally listed fish or aquatic species have been collected in the Yadkin River
near the BCCS, and none are believed to occur near the MWIS.Therefore, an incidental take exemption
or authorization for the BCCS MWIS has neither been required by USFWS nor sought by Duke Energy.
35

316(b)Compliance Submittal
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4.9 Methods and Quality Assurance Procedures for Field Efforts
Data presented in Section 4 were compiled from Duke Energy's historical and ongoing monitoring
associated with BCCS NPDES permit. Electrofishing was used to characterize the fishery for the Yadkin
River and followed Duke Energy procedures and quality assurance protocols. Sampling was also
performed under Duke Energy's NCDEQ Biological Laboratory Certification No. 008.
4.10 Protective Measures and Stabilization Activities
There are no protective measures or stabilization activities associated with BCCS.
4.11 Fragile Species
In the Rule,the USEPA identifies 14 species(§125.92(m)) of fish as fragile or having post-impingement
survival rates of less than 30 percent. Occurrence of fragile species in the Yadkin River has historically
been documented by Duke Energy(Duke Power 1994, 2003, 2011). One species from the fragile species
list, Gizzard Shad, have been documented as recently as 2018(Table 4-1),and were the most numerous
species collected in preliminary impingement sampling(Table 4-6) during operation of the now
demolished coal-fired units with once-through cooling.The remaining species included at§125.92(m)
are marine or coastal anadromous species,with the exception of rainbow smelt which is not found in
the Yadkin River. However,with the design of the BCCS MWIS it is anticipated that fragile species
impacts will be limited, if any.
36

316(b)Compliance Submittal
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5 Cooling Water System Data [§122.21(r)(5)(i)]
The information required to be submitted per 40 CFR§122.21(r)(5), Cooling water system data, is
outlined as follows:
(i) A narrative description of the operation of the cooling water system and its relationship to
cooling water intake structures;the proportion of the design intake flow that is used in the system;the
number of days of the year the cooling water system is in operation and seasonal changes in the
operation of the system, if applicable; the proportion of design intake flow for contact cooling, non-
contact cooling, and process uses; a distribution of water reuse to include cooling water reused as
process water, process water reused for cooling, and the use of gray water for cooling;a description of
reductions in total water withdrawals including cooling water intake flow reductions already achieved
through minimized process water withdrawals; a description of any cooling water that is used in a
manufacturing process either before or after it is used for cooling, including other recycled process
water flows;the proportion of the source waterbody withdrawn (on a monthly basis);
(ii) Design and engineering calculations prepared by a qualified professional and supporting data to
support the description required by paragraph (r)(5)(i) of this section;and,
(iii) Description of existing impingement and entrainment technologies or operational measures and
a summary of their performance, including but not limited to reductions in impingement mortality and
entrainment due to intake location and reductions in total water withdrawals and usage.
Each of these requirements is described in the following subsections.
5.1 Description of Cooling Water System Operation
[§122.21(r)(5)(i)]
The BCCS circulating water system is a closed-loop system with cooling water recycled and reused in the
steam turbine condenser. The purpose of the circulating water system is to supply cooling water to the
main and auxiliary steam condensers,the cooling water chiller system,and to be used as service water
for various plant uses such as fire water, boiler area wash water, and makeup water to the HRSG. The
heat transferred to the circulating water in the condenser is rejected to the atmosphere by the
evaporation process in the cooling tower. Approximately 95 percent of water withdrawn by the MWIS is
used for cooling tower makeup.
5.1.1 Cooling Water System Operation
Two vertical circulating water pumps, each rated at 135.4 MGD (94,000 gpm) supply cooling water to
the condenser and additional circulating water to the auxiliary cooling water heat exchangers. Heated
water from these systems is returned to the cooling tower through the circulating water piping. The
heated circulating water is cooled by the cooling tower and then collected in the cooling tower basin
where it flows back to the circulation pumps, and the cycle is repeated. The BCCS has one mechanical
draft counterflow cooling tower equipped with ten cooling cells, motor-driven fans, and two pumps in
the tower basin to recirculate the cooling water to the condenser. Figure 5-1 provides a schematic of
the BCCS cooling tower.
37

316(b)Compliance Submittal '
BUCK COMBINED CYCLE STATION
The cooling tower is always in operation whenever the BCCS is in operation. The cooling tower is
designed to operate with at least eight of the ten cells in operation. Typically, during the warmer
months of the year(mid-May to mid-October) all ten cells of the cooling tower are in service.
Most of water losses in the circulating water system is through evaporation in the cooling tower.
Evaporation does not carry away solids in the water such as mud, silt, or dissolved solids;therefore, it is
necessary to continuously discharge some of the circulating water to remove waste and prevent a
buildup of solids in the circulating water. This discharge, called blowdown, is routed to Outfall 006.
The cooling tower has five main components:
1. the blower type fans which direct the airflow upward,
2. the heat transfer section commonly called the "fill",
3. the water distribution system,
4. the drift eliminator section, and
5. the concrete basin which collects water for return to the condenser and other heat exchangers.
.410
twe
r iNVP \ l � i i � i r r
ELAN_VIEW ..,...m w w ....._., ....
1I �,
=
lamri��rs.•r. iii �r�ii� �rtr r�r��tr�rrf
«.. t :.:�. ." LQNG)ru INALa1EY! ..«"�.�4^."a,= .,....«.-... 3
Figure 5-1. BCCS Cooling Tower General Arrangement
5.1.2 Proportion of Design Flow Used in the Cooling Water System
Water withdrawals from the Yadkin River to support BCCS operations from 2017 through 2021 are
provided in Table 3-1 (Section 3.4). Based on the engineering design water balance diagram (Figure 3-1),
approximately 95 percent of the MWIS withdrawal is used for makeup to the cooling tower. The
remainder is used as service water for various plant uses such as fire protection water, chiller system
makeup, boiler wash water,and HRSG makeup water. Table 5-1 provides the proportion of the 7.2 MGD
DIF withdrawn during the 2017-2021 period.
38

• 316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
Table 5-1. Percent Monthly Proportion of Design Flow Withdrawn at the BCCS.
Month 2017 2018 2019 2020 2021 Average
January 39.2 38.1 41.7 0.0 42.1 32.2
February 42.8 42.0 44.6 32.4 36.0 39.5
March 44.7 34.0 1.7 43.2 43.2 33.4
April 36.5 50.6 9.1 23.0 36.0 31.0
May 46.7 51.2 50.8 42.0 45.8 47.3
June 50.8 55.8 50.7 54.9 45.9 51.6
July 54.2 59.5 56.1 61.0 59.3 58.0
August 53.2 58.5 55.4 54.4 52.4 54.8
September 49.7 60.5 52.3 7.5 42.6 42.5
October 45.6 47.7 48.9 0.0 48.1 38.1
November 44.6 44.4 42.4 38.5 48.5 43.7
December 43.7 38.8 38.7 44.9 46.0 42.4
Although historical averages are not necessarily indicative of future withdrawals, only 42.9 percent of
the DIF was withdrawn from the Yadkin River from 2017 through 2021.
5.1.3 Cooling Water System Operation Characterization
Operation of the cooling water system results in an increased makeup water demand and makeup water
pump operation. As presented in Section 3.3,the MWIS operated nearly continuously during the 2017-
2021 period with an average daily operation of approximately 20.6 hours each day(i.e., about 85.8%
each day). Steam turbine and/or combustion turbine outages typically occur in the spring and/or fall.
Monthly total flow data during the 2017-2021 period are provided in Figure 5-2. MWIS withdrawals
during the summer months (i.e., May to September) are typically higher than the remainder of the year
due to increased cooling tower evaporation resulting from higher ambient temperatures.
39

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
160.0
140.0
120.0
c
100.0 v
•
80.0
2 60.0
40.0
20.0
g
0.0 ■
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
■2017 m 2018 2019 2020 ■2021
Figure 5-2.Monthly Total MWIS Withdrawals at BCCS
At the DIF(5,000 gpm)the calculated TSV is 0.14 fps while at the AIF (2,146 gpm)the calculated TSV is
0.06 fps. Both of these values are considerably less than the 0.5 fps alternative in the 316(b) Rule for
impingement compliance. Appendix C provides TSV calculations.
5.1.4 Distribution of Water Reuse
The distribution of water reuse does not apply to BCCS because this facility does not reuse cooling water
as process water, reuse process water for cooling purposes,or use grey water for cooling purposes.
5.1.5 Description of Reductions in Total Water Withdrawals
With the retirement of BSS Units 3-6, maximum water withdrawals from the Yadkin River have been
reduced by 98.2 percent(i.e., 7.2 MGD vs. 395 MGD). The BCCS is a single combined cycle unit, natural
gas-fired electric generating facility with a current generating capacity of 660 MW. The BCCS has a DIF
of 7.2 MGD and an average AIF of 3.09 MGD for 2017-2021. As shown in Table 5 2, the BCCS is more
efficient in cooling water usage, producing 1.8 times more power output while using 98.2 percent less
cooling water compared to the retired BSS at design flows and 99.2 less at actual withdrawal flows.
Table 5-2.Comparison of BSS and BCCS.
Characteristic BSS BCCS
Total Generation,MW 370 660
Fuel Coal Natural Gas
Total Design Withdrawal, MGD 395 7.2
Cooling System Once-Through Closed-Cycle
MW/MGD Ratio 0.94 91.7
40

' • 316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
5.1.6 Description of Cooling Water Used in Manufacturing Process
BCCS cooling water is not used in a manufacturing process either before or after the water is used for
cooling.
5.1.7 Proportion of Source Waterbody Withdrawn
Withdrawal from the Yadkin River is dependent on the cooling tower makeup water demand, maximum
pump capacity, and water losses due to evaporation and system losses. Monthly average Yadkin River
flows and monthly average BCCS water withdrawals during the 2017-2021 period are provided in Table
5-3. The percent of source water withdrawal ranges from a low of 0.00 percent (March 2019,January
2020, October 2020)to a high of 0.36 percent(September 2019).
Table 5-3. BCCS Percent of Source Waterbody(Yadkin River)Withdrawal
Month 2017 2018 2019 2020 2021
January 0.16 0.21 0.05 0.00 0.09
February 0.30 0.09 0.05 0.03 0.05
March _ 0.32 0.12 0.00 0.12 0.07
April 0.06 0.10 0.02 0.05 0.08
May 0.08 0.10 0.13 0.05 0.14
-
June 0.18 0.18 0.08 0.12 0.17
July _ 0.33 0.29 0.18 0.21 0.23
August 0.34 0.12 0.24 0.09 0.19
September 0.34 0.12 0.36 0.02 0.18
October 0.22 0.07 0.23 0.00 0.28
November 0.26 0.07 0.14 0.04 0.34
December 0.31 0.04 0.09 0.07 0.33
Annual 0.18 0.10 0.09 0.05 0.13
Average
During the 2017-2021 period of record for this report,the BCCS average withdrawal was 0.11 percent of
the Yadkin River source waterbody flow.
5.2 Design and Engineering Calculations [§122.21(r)(5)(ii)]
The following table provides calculated TSV values. Appendix C presents the engineering calculations of
TSV for the cylindrical wedgewire screen design as prepared by a qualified professional.
Table 5-4. MWIS TSV Calculations
Flow Scenario Calculated TSV
AIF (2017-2021) 0.06 fps
DIF(two pumps) 0.14 fps
Maximum possible(three pumps) 0.22 fps
41

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
5.3 Description of Existing Impingement and Entrainment
Reduction Measures [§122.21(r)(5)(iii)]
The BCCS achieves substantial reductions in entrainment and impingement by means of flow reduction.
The underlying assumption for entrainment is that entrainable organisms have limited or no motility and
passively move with the water entering the power plant;therefore, reduction in flow results in a
commensurate reduction in entrainment.This flow reduction is achieved through the use of mechanical
draft wet cooling towers. Utilization of closed-cycle cooling results in a flow reduction of 98.9 percent
relative to OTC at BCCS using the 2017-2021 period of record AIF.
In addition to providing a significant reduction of organisms entrained,the lower flows associated with
closed-cycle cooling also result in a commensurate reduction in the potential for impingement at the
facility. As the MWIS cylindrical wedgewire screens have a maximum TSV of 0.14 fps at the DIF,the risk
of impingement is essentially eliminated. The annual average AIF of 3.09 MGD at BCCS(see Section 3.4)
is small and the calculated TSV is 0.06 fps. Thus,the MWIS AOI would not extend beyond the face of the
screens and is substantially less than the source waterbody current. Based on the AOl calculations,
impingement at BCCS is negligible and more likely approaches zero.
5.3.1 Best Technology Available for Entrainment
To aid the Director in making a BTA determination,the following is provided to support the conclusion
that the existing BCCS configuration and operation results in the maximum reduction in entrainment
warranted and no additional entrainment controls are warranted.
Most importantly,the BCCS uses closed-cycle cooling,which minimizes entrainment through flow
reduction. The flow reduction achieved, compared to OTC, is calculated at 98.9 percent based on the
AIF during the period of record. The EPA allows broad flexibility in the BTA determination for individual
facilities, but also supports closed-cycle cooling as a BTA option for entrainment as confirmed through
this statement in the preamble to the Rule:
"Although this rule leaves the BTA entrainment determination to the Director,with the
possible BTA decisions ranging from no additional controls to closed-cycle recirculating
systems plus additional controls as warranted, EPA expects that the Director, in the site-
specific permitting proceeding, will determine that facilities with properly operated
closed-cycle recirculating systems do not require additional entrainment reduction
control measures."
Closed-cycle cooling as a potential entrainment BTA is further reiterated in the Response to Public
Comments document,where EPA states:
"EPA has made it clear that a facility that uses a closed-cycle recirculating system, as
defined in the rule,would meet the rule requirements for impingement mortality at §
125.94(c)(1).This rule language specifically identifies closed-cycle as a compliance
alternative for the [impingement mortality] performance standards. EPA expects the
Director would conclude that such a facility would not be subject to additional
entrainment controls to meet BTA."
The final rule for new facilities as well as the new units provision within the Rule provide similar support
for closed-cycle cooling as entrainment BTA at BCCS:
42

• 316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
• The final Rule for new facilities published in the Federal Register on December 18, 2001 and
with an effective date of January 17, 2002 does prescribe BTA for entrainment, which BCCS
meets. Regulations are more stringent for new facilities than for existing facilities. By virtue of
meeting the most stringent entrainment BTA criteria (i.e., applicable to new facilities), BCCS is
compliant for entrainment BTA under the final Rule for existing facilities.
• If BCCS were classified as a new unit at an existing facility,the station would be in compliance
with the more stringent requirements stated at §125.94(e), BTA standards for impingement
mortality and entrainment for new units at existing facilities.
Beyond this regulatory guidance,the number of organisms expected to be entrained at BCCS is very low.
Since entrainment is proportional to flow, reductions in flow equate to commensurate reductions in
entrainment. The use of closed-cycle cooling as compared to an equivalent OTC facility is estimated to
reduce entrainment by 98.9 percent (AIF flow).
43

•
316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
6 Chosen Method(s) of Compliance with
Impingement Mortality Standard [§122.21(r)(6)]
The information required to be submitted per 40 CFR§ 122.21(r)(6) is as follows:
The owner or operator of the facility must identify the chosen compliance method for the
entire facility;alternatively, the applicant must identify the chosen compliance method
for each cooling water intake structure at its facility. The applicant must identify any
intake structure for which a BTA determination for Impingement Mortality under 40 CFR
125.94 (c)(11)or(12)is requested.
The Rule at 40 CFR 125.94(c)gives existing facilities seven BTA options for achieving impingement
mortality compliance.These are listed below.A facility needs to implement only one of these options.
1. Operate a closed-cycle recirculating system as defined at 40 CFR 125.92(c)(1) (this includes wet,
dry or hybrid cooling towers, a system of impoundments that are not WOTUS,or any
combination thereof);
2. Operate a cooling water intake structure that has a maximum design through-screen velocity of
0.5 fps or less;
3. Operate a cooling water intake structure that has a maximum actual through-screen velocity of
0.5 fps or less;
4. Operate an existing offshore velocity cap that is a minimum of 800 feet offshore and has bar
screens or otherwise excludes marine mammals,sea turtles, and other large aquatic organisms;
5. Operate a modified traveling screen system such as modified Ristroph screens with a fish
handling and return system, dual flow screens with smooth mesh, or rotary screens with fish
returns. Demonstrate that the technology is or will be optimized to minimize impingement
mortality of all non-fragile species;
6. Operate any combination of technologies, management practices, and operational measures
that the Director determines is BTA for reducing impingement.As appropriate to the system of
protective measures implemented, demonstrate the system of technologies has been optimized
to minimize impingement mortality of all non-fragile species;and
7. Achieve a 12-month performance standard of no more than 24 percent mortality including
latent mortality for all non-fragile species.
Compliance options 1, 2, and 4 are essentially pre-approved technologies that require minimal
additional monitoring after their installation and proper operation. Options 3,5, and 6 require that
more detailed information be submitted to the Director before they can be specified as the BTA to
reduce impingement mortality. Options 5, 6, and 7 require demonstrations with field studies that the
technologies have been optimized to minimize impingement mortality of non-fragile species.
In addition,the Rule provides two other impingement compliance BTA options for which the Director
may consider little or no additional controls for impingement mortality(USEPA 2014a). These options
apply under very specific circumstances.
44

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
• De minimis rate of impingement—if the rates of impingement at a facility are so low that
additional impingement controls may not be justified (Section 125.94(c)(11)); and
• Low Capacity utilization of generating units—if the annual average capacity utilization rate of a
24-month contiguous period is less than 8 percent(Section 125.94(c)(12)).
The BCCS meets the requirements of 40 CFR §125.94(c)(1) (BTA Option#1) based on data provided in
Table 5-2. In addition, the MWIS has a design and actual through-screen velocity of<0.5 fps and
therefore is compliant with the requirements of 40 CFR§125.94(c)(2) and (3) (BTA Options 2 and 3).
Bymeetingthe CCRS criterion (BTA#1)the existingtechnologies in use at the BCCS are BTA for
g
impingement mortality compliance. Furthermore,the MWIS has a design through-screen velocity that is
lower than the 0.5 fps standard for impingement mortality compliance.
45

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
7 Entrainment Performance Studies [§ 122.21(r)(7)]
The information required to be submitted per 40 CFR§ 122.21(r)(7), Entrainment performance studies,
is as follows:
The owner or operator of an existing facility must submit any previously conducted
studies or studies obtained from other facilities addressing technology efficacy, through-
facility entrainment survival, and other entrainment studies.Any such submittals must
include a description of each study, together with underlying data, and a summary of
any conclusions or results.Any studies conducted at other locations must include an
explanation as to why the data from other locations are relevant and representative of
conditions at your facility. In the case of studies more than 10 years old, the applicant
must explain why the data are still relevant and representative of conditions at the
facility and explain how the data should be interpreted using the definition of
entrainment at 40 CFR 125.92(h).
7.1 Site-Specific Studies
BCCS utilizes a CCRS,therefore entrainment(and survival) is not anticipated. Hence, no site-specific
entrainment performance studies(such as studies evaluating biological efficacy of specific entrainment
reducing technologies or through-facility entrainment survival) have been conducted for the BCCS.
Section 4 of this report provides a discussion of fishery monitoring conducted at or near the facility.
Section 5.3 contains information regarding entrainment reductions resulting from lower cooling water
withdrawals of the BCCS as compared to the prior BSS.
7.2 Studies Conducted at Other Locations
As of the date of this report, no entrainment performance studies conducted at other facilities have
been determined relevant for documentation in this section.
46

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
8 Operational Status [§ 122.21(r)(8)]
The information required to be submitted per 40 CFR§122.21(r)(8), Operational status, is outlined as
follows:
(i) For power production or steam generation, descriptions of individual unit operating
status including age of each unit, capacity utilization rate (or equivalent)for the
previous 5 years, including any extended or unusual outages that significantly affect
current data for flow, impingement, entrainment, or other factors, including
identification of any operating unit with a capacity utilization rate of less than 8 percent
averaged over a 24-month block contiguous period, and any major upgrades completed
within the last 15 years, including but not limited to boiler replacement, condenser
replacement, turbine replacement, or changes to fuel type;
(ii) Descriptions of completed, approved, or scheduled uprates and Nuclear Regulatory
Commission relicensing status of each unit at nuclear facilities;
(iii) For process units at your facility that use cooling water other than for power production
or steam generation, if you intend to use reductions in flow or changes in operations to
meet the requirements of 40 CFR 125.94(c), descriptions of individual production
processes and product lines, operating status including age of each line, seasonal
operation, including any extended or unusual outages that significantly affect current
data for flow, impingement, entrainment, or other factors, any major upgrades
completed within the last 15 years, and plans or schedules for decommissioning or
replacement of process units or production processes and product lines;
(iv) For all manufacturing facilities, descriptions of current and future production schedules;
and,
(v) Descriptions of plans or schedules for any new units planned within the next 5 years.
Each of these requirements is described in the following subsections.
8.1 Description of Operating Status [§ 122.21(r)(8)(i)]
BCCS is normally used for baseload generation. Plant outages typically occur during the spring(February
to May) and/or in the fall/winter(October to December) months.
8.1.1 Individual Unit Age
BCCS began commercial operations in November 2011. According to the Duke Energy Carolinas 2020
Integrated Resource Plan (IRP),there is no current projected retirement date for the BCCS.
8.1.2 Utilization for Previous Five Years
Monthly and annual average capacity factor information for 2017-2021 is provided in Table 8-1. Annual
capacity factors during this period ranged from 61.2 to 85.4 percent. Monthly capacity factors during
this period ranged from 0.0 to 93.0 percent.
47

316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
Table 8-1. BCCS Annual Capacity Factors,2017-2021.
Month 2017 �2018 2019 2020 2021
January 86.2 85.2 85.4 70.2 82.7
February 86.5 83.3 86.9 81.9 70.8
March 89.3 63.2 2.2 79.8 74.9
April 66.1 85.9 9.4 36.0 48.0
May 83.9 78.5 81.2 66.6 73.7
June 85.9 82.0 79.4 79.5 66.2
July 87.6 85.9 83.9 83.2 82.4
August 87.4 85.3 82.7 77.8 73.9
September 85.8 87.8 80.9 10.5 64.5
October 80.6 75.0 80.3 0.0 74.3
November 92.2 86.0 84.9 66.6 83.7
December 93.0 80.6 75.6 82.4 77.7
Annual Average 85.4 81.6 69.4 61.2 72.7
Note:Annual average may not equal monthly total average due to rounding.
8.1.3 Major Upgrades in Last Fifteen Years
As part of a modernization effort, Duke Energy retired BSS the final coal-fired generating units (5 and 6)
in 2013 and replaced them with a new, more efficient, natural gas-fired combined cycle facility on the
existing site. BCCS began commercial operations in November 2011.
8.2 Description of Consultation with Nuclear Regulatory
Commission [§122.21(r)(8)(ii)]
The BCCS is not a nuclear fueled unit;therefore,this subsection is not applicable.
8.3 Other Cooling Water Uses for Process Units [§122.21(r)(8)(iii)]
The BCCS is not a manufacturing facility;therefore,this subsection is not applicable.
8.4 Description of Current and Future Production Schedules
[§122.21(r)(8)(iv)]
The BCCS is not a manufacturing facility;therefore,this subsection is not applicable.
8.5 Description of Plans or Schedules for New Units Planned within
Five Years [§122.21(r)(8)(v)]
During the next five years,there are no plans to decommission, replace, or add new units at this facility
as stated in the 2020 IRP.
48

316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
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BUCK COMBINED CYCLE STATION
Tatarenkov,A., Barreto, F.S., Winkelman, D.L., and J.C. Avise. 2006. Genetic monogamy in the Channel
Catfish, Ictalurus punctatus, a Species with Uniparental Nest Guarding. Copeia 4: 735-741.
Tetra Tech, Inc. 2004. Water quality data review for High Rock Lake, North Carolina. Durham, NC.
United States Endangered Species Act(ESA). 1973. https://www.fws.gov/endangered/esa-
library/pdf/ESAall.pdf.
United States Fish and Wildlife Service(USFWS). Information for Planning and Consultation (IPaC),
Environmental Conservation Online System. Accessed 7/20/21. [URL]:
https://ecos.fws.gov/ipac/.
United States Environmental Protection Agency(USEPA). 2014. National Pollutant Discharge Elimination
System - Final Regulations to Establish Requirements for Cooling Water Intake Structures at
Existing Facilities and Amend Requirement at Phase I Facilities; Final Rule. 40 CFR Parts 122 and
125. Federal Register Vol. 79 No. 158. August 15, 2014.
University of Michigan. 2017. Animal Diversity Web, Museum of Zoology.Accessed 13 July 2017.
Wang,J.C.S and R.J. Kernehan. 1979. Fishes of the Delaware Estuaries.A Guide to the Early Life
Histories, Towson, MD. pp.410. ISSN 0-931842-02-6.
Weiss, CM,TP Anderson, and PH Campbell. 1981. The water quality of the Upper Yadkin Drainage Basin
and High Rock Lake. Department of Environmental Sciences and Engineering. School of Public
Health. University of North Carolina at Chapel Hill. Chapel Hill, NC.
Wellborn,T.L. 2008. Channel Catfish Life History and Biology. Southern Regional Aquatic Center [SRAC]
Publication No. 180, College Station,TX.
Williamson, K.L., and P.C. Nelson. 1985. Habitat Suitability Index Models and Instream Flow Suitability
Curves: Gizzard Shad. U.S. Fish and Wildlife Service Biological Report 82(10.112). Washington,
DC.
51

316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
Appendices

316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
Appendix A. Buck Combined Cycle Station §122.21(r)(2)
— (8) Submittal Requirement Checklist.
71 (2)(i) Narrative description and scaled drawings of source Yes
waterbody.
s a (2)(ii) Identification and characterization of the source Yes
c waterbody's hydrological and geomorphological
3 o features, as well as the methods used to conduct any
a, physical studies to determine intake's area of
li influence within the waterbody and the results of
0 such studies.
N (2)(iii) Locational maps. Yes
`+-° (3)(i) Narrative description of the configuration of each Yes
c CWIS and where it is located in the waterbody and in
a,
3 the water column.
c u (3)(ii) Latitude and Longitude of CWIS. Yes
o v, (3)(iii) Narrative description of the operation of each CWIS. Yes
" Y (3)(iv) Flow distribution and water balance diagram. Yes
M 1
c (3)(v) Engineering drawing of CWIS. Yes
(4)(i) A list of the data supplied in paragraphs (r)(4)(ii) Yes, but not
Y through (vi) of this section that are not available and applicable
o efforts made to identify sources of the data. because all data
c is available.
0
CC (4)(ii) A list of species (or relevant taxa)for all life stages and Yes
.,
their relative abundance in the vicinity of CWIS.
o (4)(iii) Identification of the species and life stages that would Yes
s be most susceptible to impingement and entrainment.
u
o (4)(iv) Identification and evaluation of the primary period of Yes
'NM reproduction, larval recruitment, and period of peak
° abundance for relevant taxa.
'm (4)(v) Data representative of the seasonal and daily Yes
c activities of biological organisms in the vicinity of
a, CWIS.
o — I
m (4)(vi) Identification of all threatened, endangered, and Yes
;; other protected species that might be susceptible to
3 impingement and entrainment at cooling water intake
cu structures.
(4)(vii) Documentation of any public participation or Yes, but not
0
`^ consultation with Federal or State agencies applicable.
re-
undertaken in development of the plan.
A-1

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
(4)(viii) Methods and QA procedures for any field efforts. Yes, but not
applicable as no
new data have
been collected.
(4)(ix) In the case of the owner or operator of an existing Yes, noted in
facility or new unit at an existing facility,the Source report that(i)
Water Baseline Biological Characterization Data is the through (xii)
information included in (i)through (xii). provide this
information.
(4)(x) Identification of protective measures and stabilization Yes
activities that have been implemented, and a
description of how these measures and activities
affected the baseline water condition in the vicinity of
CWIS.
(4)(xi) List of fragile species as defined at 40 CFR 125.92(m) Yes
at the facility.
(4)(xii) Information submitted to obtain Incidental take Yes, but not
exemption or authorization for its cooling water applicable.
intake structure(s)from the U.S. Fish and Wildlife
Service or the National Marine Fisheries Service.
(5)(i) Narrative description of the operation of the cooling Yes
water system and its relationship to CWIS.
(5)(i) Number of days of the year the cooling water system Yes
is in operation and seasonal changes in the operation
of the system.
(5)(i) Proportion of the design intake flow that is used in the Yes
system.
p — _
(5)(i) Proportion of design intake flow for contact cooling, Yes
24) non-contact cooling, and process uses.
(5)(i) Distribution of water reuse to include cooling water not applicable
4.4
reused as process water, process water reused for
cooling,and the use of gray water for cooling.
(5)(i) Description of reductions in total water withdrawals Yes
including cooling water intake flow reductions already
achieved through minimized process water
withdrawals.
(5)(i) Description of any cooling water that is used in a not applicable
manufacturing process either before or after it is used
for cooling, including other recycled process water
flows.
(5)(i) Proportion of the source waterbody withdrawn (on a Yes
monthly basis).
A-2

316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
(5)(ii) Design and engineering calculations prepared by a Yes
qualified professional and supporting data to support
the description required by paragraph (r)(5)(i)of this
section.
(5)(iii) Description of existing impingement and entrainment Yes
technologies or operational measures and a summary
of their performance.
Identification of the chosen compliance method for the entire Yes
CWIS or each CWIS at its facility.
(6)(i) Impingement Technology Performance Optimization No, not selected
Study for Modified Travelling Screen. compliance path
Two years of biological data collection. and thus not
applicable.
121 L
u rp
c -p
to c
E
o
o L Demonstration of Operation that has been optimized
• 2 to minimize impingement mortality.
sc Complete description of the modified traveling
-, E screens and associated equipment.
2 m (6)(ii) Impingement Technology Performance Optimization
c
. Study for Systems of Technologies as BTA for
r E Impingement Mortality.
Minimum of two years of biological data measuring
the reduction in impingement mortality achieved by
the system.
(7)(i) Site-specific studies addressing technology efficacy, Yes; note that no
through plant entrainment survival, and other site-specific
impingement and entrainment mortality studies. studies were
conducted at this
facility.
a a (7)(ii) Studies conducted at other locations including an Yes; note that
explanation of how they relevant and representative. studies at other
E v, locations were
not determined
to be relevant.
(7)(iii) Studies older than 10years must include an not applicable
( )( ) PP
explanation of why the data are still relevant and
representative.
ro (8)(i) Description of individual unit age, utilization for Yes
0 0 c previous 5 year, major upgrades in last 15 years.
A-3

•
316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
(8)(ii) Descriptions of completed, approved, or scheduled Yes, but not
uprates and Nuclear Regulatory Commission applicable.
relicensing status of each unit at nuclear facilities.
(8)(iii) Other cooling water uses and plans or schedules for Yes, but not
decommissioning or replacing units. applicable.
(8)(iv) For all manufacturing facilities, descriptions of current Yes, but not
and future production schedules. applicable.
(8)(v) Descriptions of plans or schedules for any new units Yes
planned within the next 5 years.
A-4

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
Appendix B. Engineering Drawings of Cooling Water
Intake Structure
• Drawing D000846153: T-30 X 24 HC Intake Screen Assembly With 3" ABW
Connection
• Drawing BUKOC-PY-P-RW.00.EV-01: Buck Combined Cycle Station Raw
Water Supply Pump Station and Screen Elevation Views
• Drawing BUKOC-SS-S-IS.00.SD-01: Buck Combined Cycle Station Raw Water
Supply Intake Structure Structural Sections and Details
B-1

316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
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BUCK COMBINED CYCLE STATION
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Appendix C. Engineering Calculations for Through-
Screen Velocity
ci

I. c , s
316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
Buck Combined Cycle Station
316(b) Report
Through-Screen Velocity Calculations- Data Sheet
Mike Smallwood (rev 2022-0319)
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Screen Data
Screen Open Area =63.78%
Total Screen Area =5,644 in2
Total Screen Open Area = 3,599 in2
Slot Size=3.2mm
Diameter=30 in
Total Length = 101.01 in
Screen Length =31 in (x2 for each T screen =62 in)
Pump Data
Design Flow/Pump=2,500 gpm
Design Intake Flow=5,000 gpm (assumes two pumps operating and one spare)
Actual Intake Flow(2017-2021) =2,146 gpm (3.09 MGD)
Screen Source Data:Johnson Screens Drawing D000846153 (2014)
C-2

316(b) Compliance Submittal
BUCK COMBINED CYCLE STATION
Formulas conversion factors
1:V= Q/A 1 gallon = 0.1337 ft3
2:A= N*n*D*L*POA 1 minute = 60 seconds
Solve for A Using Formula 2
where:V=through screen velocity, fps Q= pump flow, gpm
A=surface area of screen open mesh,ft2
N = number of wedgewire screen units(3)
D =diameter of wedgewire screen unit,ft
L= length of open mesh area for each screen unit,ft
POA= percent open area
A= (3) * (n) * (2.5) * (5.17) * (0.6378) = 77.69 ft2
Solve for TSV at Design Flow Using Formula 1
TSV= [(5000) * (0.1337) * (1/60)] /(77.69)
DIF TSV= 0.14 fps
Solve for TSV at Average Flow Using Formula 1
TSV= [(2146) * (0.1337) * (1/60)] /(77.69)
AIF TSV= 0.06 Fps
C-3

t
316(b)Compliance Submittal
BUCK COMBINED CYCLE STATION
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C-4