NCS000548_Monitoring Reports_20211101

DUKE DUKE ENERGY CORPORATION
ENERGY, Marshall Steam Station
8320 East NC Highway 150
Terrell,NC 28682
October 28, 2021
NC Dept. of Environmental Quality
Attention: Central Files '
Division of Water Resources
1617 Mail Service Center r
Raleigh, NC 27699-1617 -
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548 — Catawba County
Year 1 Period 3 monitoring
Dear Sir or Madam:
In accordance with Part E-2. of the above referenced NPDES Stormwater permit, the original and
one copy of the Stormwater Discharge Outfall (SDO) monitoring reports for Period 3 Year 1 is
attached.
Representative samples were not collected from stormwater outfalls sitewide during the third
quarter (Period 3) of 2021 due to NO FLOW conditions at the facility. A total of seven
measurable storm events occurred over this period that met the following criteria: A) the event
initiated outside of normal business hours during the week; B) the event initiated on weekend
days; or C) the event occurred inside the 48-hour period from a previous unqualified storm
event. Therefore, this report is submitted as formal notification of the NO FLOW conditions at the
site for Period 3 2021.
Currently stormwater outfalls SW002, SWO03 and SWO07 remain in Tier 1 status resulting from a
benchmark exceedance as reported from the June 7, 2021 monitoring event. A Tier 1 response
was completed, and corrective actions implemented. Reports are on file in the facility SWPPP.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Scott La Sala (828-478-7820) or Don Safrit at [phone].
Sincerely,
Jeffrey Flana
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION
Marshall Steam Station
8320 East NC Highway 150
Terrell,NC 28682
be w/attachment: Scott La Sala
Don Safrit
File: CCP EHS
UPS Tracking Number 1Z8955X40399112982 Raleigh Central Office
www.duke-energy.com

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS(100548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2021
(This monitoring report shall he received by the Division no later than 30 days from the date the
facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S) J Scott Lu Sala PHONE NO. [phone]
CERTIFIED LABORATORY(S) Duke Energy Lab N 249
Pace Huntersville Office Lab N 530
Shealy Environmental Services,Inc. Lab#329 SIGNATURE OF PERMITTEE OR DESIGNEE
REQUIRED ON PACE 2
Part A:Specific Monitoring Requirements
Outfall Date 00401) 01077 01002 01022 01012 01027 01034 01042
No. Sample Total Rainfall pH Silver,Total(as Arsenic,Total(as Boron,Total(as Beryllium,Total Cadmium,Total Chromium,Total Copper,Total(as
Collected Ag) As) B) (as Be) (as Cd) (as Cr) Cu
molddl r inchrs unit m W L mg1l, m L m L m h m L m L
SW'002 NO FLOW
SW003 NO FLOW
SW007 INO FLOW
S W008 NO FLOW
SWoll NO FLOW
SW012 NO FLOW
SWO12A outfall permanent] abandonded
SW022 NO FLOW
SW025 NO FLOW
SWO26 Dutrall not yet in service
Outfall Dale 01067 01051 01097 01147 01059 01092 71900 C0530 00556
No. Sample Nickei,'Total(as Lead,Total(as Antimony,Total Selenium,Total Thallium,Total Zinc,Total(as Zn) Mercury,Total Solids,Total Oil St Grease
Collected Ni) Ph) (as Sb) (as Se) (as TO Method 1631 E Suspended-
Concentration
mo/dd/ r m L m mg1L mWL m L mg1L n L m m
SW002 NO FLOW
SWO113 NO FLOW
SWO07 NO FLOW
SW008 NO F'LO%i
SWOT l NO FLOW
SWO12 NO FLOW
SWO12A outfall abandonded
SW022 NO FLOW
SW025 NO FLOW V 11 1-Ll4
SWO26 outfall not yet in service
Permit Number Iti1C5000546 form SWU-247,last revised 4/1/2021
Page 1 of 2

Does this facility perform Vehicle Maintenance Aciivities using more than 55 gallons of new motor oil Ia r nwnih' ce% K nO
(if yes.complete Part B)
Part B.Vehicle Maintenance Activity Monitoring Requirements
Outfall Date
No. Sample
Collected
mo/ddlyr
STORM EVENT CHA RA CTERINTICS:
Mail Original and one copy to:
Date Division of Waicr Quality
Total Event Precipitation(inch"). NO FLOW Attn:Central files
Event Duration I hours): (only if applicable—see permit.t 1617 Mail Service Center
Raleigh,North Carolina 27699-1617
(if more than one storm event was snmpled)
Date
Total Event Precipitation(inches):
Event Duration(hours): (only if applicable—see permit.)
1.1 certify,under penalty of law,that this document and all attachments were prepared under my direction or supervision in accordance with a system
designed to assure that qualified personnel properly gather and evaluate the information submitted.Based an my inquiry of the person or persons who
manage the syslem,or those persons directly responsible for gathering the information,the information submitted is,to the best or my knowledge and belief.
true,accurate,and complete.I am aware that there are significant penalties for submitting raise information,including the possibility of fines and
imprisonment for knowing violations."
ZL_
t5ignalu of t Olaic)
Form SWU-247,last revised 4/1/2021
Permit Number NC5000548 Page 2 of 2

=;:, DUKE DUKE ENERGY CORPORATION
N ENERGY, Marshall Steam Station
8320 East NC Highway 150
Terrell,NC 28682
July 15, 2021
REECEI E D
NC Dept. of Environmental Quality JUL 2 6
Attention: Central Files CENTRAI E,, c�
Division of Water Resources S ,%
DWR ,,ECT;0;v
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548 — Catawba County
Year 1 Period 2 monitoring
Dear Sir or Madam:
In accordance with Part E-2. of the above referenced NPDES Stormwater permit, the original and
one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of the
Tier II monthly sampling is attached.
Representative samples were collected from stormwater outfalls SW002, SW003, SW007,
SW008, SW011, SW012, SW022 and SW025 on June 7, 2021. The attached summary of
corresponding analytical results indicate that three outfalls are reported with targeted constituents
above corresponding permit benchmarks. These include the following:
• SWO02 (Mercury, 12.1 ng/L)
• SWO03 (total suspended solids, 130 mg/L; Copper, 0.0139 mg/L; and Mercury, 13.5 ng/L)
• SWO07 (Zinc, 0.151 mg/1)
In response to the benchmark exceedances, Tier 1 inspections were performed at these outfalls on
June 29, 2021. A Tier 1 status email notification was submitted to the agency on June 30, 2021.
Feasible corrective actions were identified in the Tier 1 reports and are currently in the process of
being implemented at the facility.
As directed to the agency, outfall SW012A was abandoned in 2020 and the grade was adjusted to
allow for sheet flow of stormwater in this area. To date, outfall SW026 has not been constructed.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Scott La Sala (828-478-7820) or Don Safrit at [phone].
Sincerely,
� A4&--�
Rick R.'Roper
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION
Marshall Steam Station
8320 East NC Highway 150
Terrell,NC 26682
cc w/attachment: James Moore, MRO
be w/attachment: Scott La Sala
Don Safrit
r'il r•l__ ri-n C t3
C. L�.t' CrIJ
UPS Tracking Number 1Z8955X40399668801 Raleigh Central Office
1Z8955X40399128411 James Moore, MRO
www.duke-energy.com

STORM WATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2021
(This monitnring report shall he remised by the Division no later than 30 days from the date the
facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S) J Scott La Sala PHONE NO. [phone]
CERTIFIED LABORATORY(S) Duke Energy Lab#248
Pace Huntersville Office Lab#530
Shealy Environmental Services,Inc. Lab#329 SIGNATURE,OF PERNIMEE OR DESIGNEE:
RE UIRED ON PAGE 2
Part A:Specific Alonitoring Requirements
Outfall Date (10.1110 01077 01002 01022 01012 01027 01034 01042
No. Sample Total Raiol'all Jill Silver,Total(as Arsenic,Total(as Boron,Total(as Beryll)um,Total Cadmium,'rotal Chromium,Total Copper,Total(as
Collected Ag) As) B) (as Be) (as Cd) (as Cr) Cu)
molddlsr inches unit mgtL m m mgfL mgfL T91L mgf
S W002 6/7/2021 0.59 7.2 <0.0003 0.00133 <0.05 <0.001 <O.00I 0.00254 11.00323
S WO03 i6r7120211 0.59 J7.8 <0.0003 0,00376 1<0105 <0.U01 <0.001 10.00775 0.0139
SW007 6/7/2021 (1.59 17.2 <0.0003 <0.001 <0.05 10.001 <0.001 <0.001 0.011648
SWO08 6n12021 (F 59 17A
S%VOII 6/7/2021 0.59 17.0 c0.1101 <U.001
S WO12 6/7/2021 059 17.6
SW012A outfall pvrrnanently abandonded VE D
544'022 6/7/2021 0.59 17.4
S44'025 61712az1 a59 7.5 2021
SW026 outfall not vel constructed
Outfall Date 01067 01051 01097 01I47 01959 01092 71900 C0530 00 .qtILEF,
No. Sample Nickel,Total(as Lead,Total(as Antimony,Total selenium.'rotal Thallium,Total Zinc,Total(as Zn)Mercury,Total Salads Total 0i &C 1.6
Collected Nit Ph) (as Sb) (as Se) (as Ti) Method 1631 E Suspended-
Concentration
mulddlvr m L m L mWL m L ingli. mg1L n m m L
SWO02 6n12021 <0.001 0.01146 <0.001 <0.001 <0.00412 11.057 12.1 35
SWO03 IV712021 11.00263 10.0062i <0.001 10.0022 0.000257 11.059 13.5 130
SWO97 6/7/2021 4.001 <0.1101 <0.001 <0.001 4.0002 0.151 5.20 8.9 <4.9
SWUM 6n12021 1 7.9
SW011 6/7/2021 <0.001 0.036 7.2
SW012 61712021 1 1 19
SWO12A 6R121121 outfall abandonded
SW022 6n12021 17.4
SW025 W/2021 139
SW026 Ifin121121 joutfalL not vet constructed
Benchmark exceedances include Zinc.Tolal(as 7.n)at SWO07
Benchmark exceedanees include Solids.Total Suspended-Concentration and Copper.Total(as Cu)and Mercury.Total Method 1631 E at S WO03
Benchmark exceedances include Mercury.Total Method 1631 E at SWO02
form SWU-247,last revised 4/1/2021
Permit Number NC5000548 Page 1 of 2

Does this facility perform Vehicle Maintenance Activities using more than 55 gallons of new motor oil per month? yes X no
lif yes,complete Par H)
Part R.Vehicle Maintenance Actiy ity Munituring Requirements
Outfall Date
No, Sample
Collected
mo/ddl r
STORM EVENT CHARACTERISTICS:
Mail Original and one copy to:
Dale 06/07/2021 Division of Water Quality
Total Event Precipitation(inches): 0.59 Ann!Central Files
Event Duration(hours): (only if applicable—see permit.) 1617 Mail Service Center
Raleigh,North Carolina 27699-1617
(if more than one storm event was sampled)
Date
Total Event Precipitation(inches):
Event Duration(hours): (only if applicable—see permit.I
"1 certify,under penalty of law,that this document and all atlachmeutS xere prepared under my direct inn or supervision in accordance with a system
designed nr assure that qualified personnel properly gather and evaluate the information submitted.Rased on my inquiry of the person or persons who
manage the system,or those persons directly responsible for gathering the information,the information suhmilled is,to the hest of my knowledge and belief,
true,accurate,and complete.I am aware that there are significant penalties for submitting false information,including the possibility of Fines and
imprisonment for knowing violations."
"e" !!��- (Fo,L �:,lc �� 7- oa
tSignature of Per eel I[)are)
Form SWU•247,last revised 4/1/2021
Permit Number NCSOOOS43 Page 2 of 2

STORIIWATER DISCHARGE OUTF'ALL(SDO)
MONITORING REPORT
Vermft Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2011
IThis monitoring report shall he revvived by the Ilivision nu later than 30 days from the dale the"
t'acility receives the samplln„results from the laborutory.)
VACILITY NAME Marshall Stearn Station COUNTY Catawba
PERSON COLLF.CI ING SAMPLE(S) ,)Scott La Snla PHONE NO. (0041631-8(142 —�
CERTIFIED LABORATORY(S) Duke Energy Lab it 248
Pace Huntersville Office Lab 8$30
Shealy Environmental Services,htc. Lab 0 329 SICNATURIS OP PERM OR DESIGNBG
RE UIRED'ON PACE 2
I+art.A:Specific Monitoring Requirement,
Ootrall Date 00400 01077 0IW2 01022 01012 01027 U103a I11042
Sample Total Rainfall pH Silver,Total(as Arsenic,Total(as Boron,'1'nlal(as Beryllium,Total Cadmlutn,'I'utal Chromium,"atpti Cnpller,'ro(ul(ah
Collected Agi As) A) lus Be) (as Cd) las Cr} Cut)
mcdddhr inches unit m L mFj m L m L In L to L rtt L
SW11112 617/2021 039 7.2 <0.0003 0.00133 <0.05 <0.f}01 <0,001 0,00254 0,00323
tiW0113 (012021 (1.59 7.8 <0,0003 0,00370 <1I.O5 _ di.OUl r0.11G1 lit.1H1775� 11111119
SW007 _61712U21 f1.S9 7.2 <00103 <0,001 <0.05 d!,(101 0.001 d1,001 0.00648
SW0U8 6/7/2021 11.59 7.4
SWIM 1 6/712(121 11159 7A _ 0,001 0.001
SW'012 6/7/2021 11.59 7.6
SWO12A_ outrall permanently abandonded
SW022 6/7/2021 0.5H 7.4
SW'025 6I712112i 0.59 7,5
SW026 outrall not vet constructed
Outrnll Datc 01067 010S1 01097 01147 01059 411092 71900 C05311 IMI556
No. Sample Nickel,Toinl(a, Lrad,'I'otal(as Antimony,Total Selenluat,'i'atul Thallium,,rofnl line,Total(as Zn)Mercury.Total Solids,Tntul Oil&Greasa
('o0ccted Ni} Ph) (as Sb) (aS SO (us Th Method 1631 E ,Swpended-
Conecnfratitin
mowIdd! r to L m L m I. m L m L m L n L m L m i.
SWO02 61701121 <0,001 0.00146 <0,0111 <0,1101 <0.0002 0.057 111 35
S1VO03 6n/21121 11,0263 0.00625 <0.001 0,0022 0..WO.2 7 0.1159 133 1130
SW'007 16M21121 <(1001 <0.001 <111.001 19.001 <0.0002 0.151 520 18.9 <4')
SWI108 16m2021 17,9
S W 011 6171202 i <0.001 u,u3t, 7.2
SW012 6/712021 Ey
SW0l2A 617/2021 outrall ahandonded
SW022 61.112U21 7,,E
S15412.5 61712U21 39
S►V026 6/7/2021 111LItfAll not vet curtstructed
Hi nihnp3lh CxeNLYIanCCa m,111LIC Zinc.1'Mid(a,Z11)at SW(K)7
Benchmark e w"dunccn mchide Solids.Tan:l Suspended-Concentration and Copper.Total ire;Cu)and Mercury.Tutnl Method f 61l U at SW003
ft%�nchmaik exLvedance,nieliidc Mercury.Total Meihod:611 E=at SWO02
form SW U•24 7,last rcvisod 4/1/2022
Permit Number NCSO40548 Pape 1 of 2

I L'es Ihts ta'IIIIt t Crlorm VCll It,la hlaullertmntr Acltvllw%using More t III]lt 5i gallons 151 MW molar nil per month" �.•, x au
ill vc,,Curnplele Part M
Part R:4ehirlc Maintenance Activity Moniturink Requirements
Outfall Date
No. Sample.
Cullerled
mulddlr r
STORNI EVENT C11ARAC"{FRISTICS:
Mait Original and one copy to:
Dale• 06/07r112 1 INVIStrlrt of Witter syu;diI%
Tulai Event 1'MCiphatian ilnches): 059 Alin,C enlral files
Event Duration(boom: lnnly It:rppllCahle-see I)[mlil l 1617 N-1 ail Service Center
Raleigh,Nor dt Caroltna 27640-1 h 17
i d iuuu�Nam nnc s[w uI cs cal lri.sampled I
Dale
Fatal Etenl 1'recipilation Onrbesr;
Event Duration(hours), sty il nplrltesidc- sec Ixnnit f
"1 evrtify,under penalty of lair,that this dw-rimeal and rill attachtnculs were prepared under my direction ar sapervtsinn in accnrdaace with a system
designed to assure that qualified personnel property gather and evaluate the information subnvilred.Rased an my inquiry of the person or persons who
manage the system,or thou ltersotts directly re%1xinsible for gathering the infortnution,the information suboti teed is,to the best or my knowledge and belief,
true,aetiurate,and complele.1 am aware lhal Isere are cignllicant punallies fur subntitting false tuFonnation.Including the InKsibility or riaLs.and
imprisonment far knowing violatinlu."
1.5-20a
(Signature ofPernl eel rDaw
a
Form SWU•247,last revised 4/V/1021
Perrnit Number WS000S48 Page 2 of 2

'�� DUKE DUKE ENERGY CORPORATION
ENERGY® Marshall Steam Station
8320 East NC Highway 150
Terrell, NC 28682
April 27, 2021 ,���/E��
..
mg 0 3 Z021
NC Dept. of Environmental Quality
Attention: Central Files � " � lSE_GT 1 E'
Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548 — Catawba County
Year 6 Tier ill monitoring
Dear Sir or Madam:
In accordance with Part III, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of
the Tier II monthly sampling is attached.
A representative Stormwater sample was collected from SWO08 on March 31, 2021, pursuant to
Tier 3 requirements. Outfall SWO08 remains in Tier 3 status for four intermittent TSS values
reported outside the benchmark range within the existing permit cycle ending April 1, 2021.
A renewed industrial stormwater permit for Marshall Steam Station was received on March 29,
2021 (effective on April 1, 2021) and requires an increase of listed facility stormwater outfall
monitoring from semi-annual to quarterly increments. Subsequently, the facility anticipates
conducting a monitoring event for Period 2 of 2021 between April 1, 2021 and June 30, 2021.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Sincerely,
Rick R. Roper
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION
Marshal!Steam Station
8320 East NC Highway 150
Terrell,NC 28682
be w/attachment: Scott La Sala
Robert Wylie
File: CCP EHS
UPS Tracking Number 1Z8955X40399295115 Raleigh Central Office
www.duke-energy.com

STORM WATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR. 2021
(This monitoring report shall he received by the Division mr later Ibaa 30 days from Ilse date the
facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S) Scott LaSulal/Scott LaSala/Dukc Analytical Laboratory Services PHONE NO. [phone]
CERTIFIED LABORATORY(S) Duke Energy Lab#NC248
Lab#
SIGNATURE OF PERMI'r7'EE OR DESIGNEE
REQUIRED ON PAGE 18725
Part A:Specific Monitoring Requirements
Outfall Date 50050 00404) 01077 01002 01022 01012 01027 (11034
No. Sample Total Rainfall Total Flow(if pl1 Silver,Total(as Arsenic,Total(as Boron,Total(as Berytlium,Told Cadmium,Total Chramium,Total
Collected app.) Ag) As) 11) (as Be) (as Cd) (as Cr)
molddlyr inches INiG unit m , mgtL m m L rn;plL m L
SNV008 3/31/2021 0.56 NIA 7.0
Outfalt Date 01042 01067 01051 01097 01147 01059 01092 71900 C0530
No. Sample Copper.'rotal(as Nickel,Total(as Lead,Total(as Antimony,Total Selenium,Total Thallium,Total Zinc.Total(as Zn)Mercury,Total Solids,'1'ota!
Collected Cu) Ni) Pb) (as Sb) (as SO (as Ti) Method 1631 E Suspended-
Conrentrrlion
moldd/yr m L ra L m L mo, MPA, nt+L m L n L m 1.
SW(108 3/31/2021 39
Oulfall Date 34671 39488 39492 39496 39500 39504 39508 00556
No. Sample PCB-1016 PCB-1221 PCB-1232 PCB-1242 PCB-1248 PCB-1254 PCB-1260 Oil&Grca.c
Collected (Arochlor 1016) (Arochlor 122I) (Arochlor 1232) (Arochlor 1242) (Arochlor I M) (Arochlor 1254) (Arochlor 1260)
me/ddl yr ug1l u u u u u ugn rtic/l.
SIV008 3/31/2021
Form SWU-247,last revised 9/19/2018
Permit Number NCS000548 Page 1 of Z

Does this facility perform Vehicle Maintenance Activities using more than 55 gallons ofnew motor oil per month? yes X no
(if yes,complelc Part S)
Part li:Vehicle Maintenance Activity Monitoring Requirements
Outfall Date 50050 00400 00530 00556
No. Sample Total Rainfall Total Flow(if pH 'total Suspended Oil&Grease(if Non-polar New Motor Oil
Collected applicable) Solids appl.) O&GITPH Usage
(Method 1664
SCT-HEi4i),if
appl.
mo/dd)vr inches MG Fait mlJl mg/I imo al/mo
STORM EVENT CHARACTERISTICS:
Mail Original and one copy to:
Date 03/31I2021 Division of Water Quality
Total Event Precipitation(inches): 0.56 Attn:Central Files
Event Duration(hours): 4 (only if applicable—see fxrmit.) 1617 Mail Service Center
Raleigh.North Carolina 27699-1617
(if mate than one storm event was sampled)
Elate
Total Event Precipitation(inches):
Event Duration f onus): (only ifapplicable—seepermit.)
"I certify,under penalty-of law,that this document and at]attachments were prepared under my direction or supervision in accordance with a system
designed to assure that qualified personnel properly gather and evaluate the information submitted.Rased on my inquiry of the person or persons who
manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the best of my knowledge and belief,
true,accurate,and complete.I am aware that there are significant penalties for submitting false information,including the possibility or pines and
imp s ni rnr know in iofatinns,"
(Signature of I ermittee) (1)a cl
Form SWU-247,last revised 9/19/2018
Permit Number NC5000548 Page 2 of 2

� ' DUKE DUKE ENERGY CORPORATION
ENERGYm Marshall Steam Station
8320 East NC Highway 150
Terrell, NC 28682
March 30, 2021
NC Dept. of Environmental Quality
Attention: Central Files APR 0 5 ZDZ1
Division of Water Resources C'C�v t tiL FILES
1617 Mail Service Center GUT SEC7II_6
Raleigh, NC 27699-1617
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548 —Catawba County
Year 6 Tier II monitoring
Dear Sir or Madam:
In accordance with Part III, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of
the Tier 11 monthly sampling is attached.
Representative samples were not collected from SWO08 during February 2021 because of NO
FLOW conditions at the facility, including stormwater events not initiating during daylight hours or
stormwater events that did initiate on weekend days or inside 72-hour period since the last
stormwater event. Therefore, this report is submitted as a formal notification of the NO FLOW
conditions at the site for February 2021.
Outfall SWO08 remains in Tier 3 status for four intermittent TSS values reported outside the
benchmark range within the existing permit cycle ending April 1, 2021. A renewed industrial
stormwater permit for Marshall Steam Station was received on March 29, 2021 (effective on April
1, 2021) and requires an increase of listed facility stormwater outfall monitoring from semi-annual
to quarterly increments. Subsequently, the facility anticipates conducting a monitoring event for
Period 2 of 2021 between April 1, 2021 and June 30, 2021.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Sin erely,
Rick R. Roper
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION
Marshall Steam Station
• 8320 East NC Highway 150
Terrell,NC 28682
be w/attachment: Scott La Sala
Robert Wylie
File: CCP EHS
UPS Tracking Number 1Z8955X40391559836 Raleigh Central Office
www.duke-energy.com

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2021
(This monitoring report shall be received by the Division no later than 30 days from
the date the facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S)Staff PHONE NO. [phone]
CERTIFIED LABORATORY(S)Duke Energy of the Carolinas LLC Lab#248
SIGNATURE OF PERMITTEE OR DESIGNEE
Part A: Specific Monitoring Requirements REQUIRED ON PAGE 2.
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/dd/ r inches m
SW008 NO FLOW
Samples were not collected from stormwater outfall SWO08 during February 2021 as a result to NO FLOW conditions.
Form SWU-247, last revised 2/2/2012
Page I of 2

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Does this facility perform Vehicle Maintenance Activities using more than 55 gallons of new motor oil per month?_yes X no
(if yes,complete Part B)
Part B: Vehicle Maintenance Ac ivity Monitoring Requirements
Outfall Date 50050 '00556 00530 00400
No. Sample Total Flow Total Oil &Grease Non-polar Total ptl New Motor
Collected (if applicable) Rainfall (if appl.) O&G/TPH Suspended Oil Usage
(Method 1664 Solids
SGT-HEM),if
appl.
mo/dd/ r MG inches III-1 m unit tial/mo
STORM EVENT CHARACTERISTICS: Mail Original and one copy to:
Division of Water Quality
Date NO FLOW Attn: Central Files
Total Event Precipitation(inches): NA 1617 Mail Service Center
Event Duration(hours): (only if applicable—see permit,) Raleigh,North Carolina 27699-1617
(if more than one storm event was sampled)
Date
Total Event Precipitation(inches):
Event Duration(hours); (only if applicable—see permit.)
"I certify,under penalty of law,that this document and all-attachments were prepared under my direction or supervision in accordance with a
system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person
or persons who manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the
best of my knowledge and belief,true,accurate,and complete. I am aware that there are significant penalties for submitting false information,
including the possibility of fines and imprisonment for knowing violations."
(Signature of Permitt } (Date)
Form SWU-247, last revised 21212012
Page 2 of 2

DUKE DUKE ENERGY CORPORATION
ENERGY. Marshall Stearn Station
8320 East NC Highway 150
Terrell, NC 28682
February 24, 2021
NC Dept. of Environmental Quality dZEriz—I V EU
Attention: Central Files MAR 01 2021
Division of Water Resources CEN
1617 Mail Service Center DWR S- FILES
Raleigh, NC 27699-1617 eCrIQN
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548— Catawba County
Year 6 Tier II monitoring
Dear Sir or Madam:
In accordance with Part Ili, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of
the Tier II monthly sampling is attached.
Representative samples were not collected from SWO08 during January 2021 because of NO
FLOW conditions at the facility, including stormwater events not initiating during daylight hours or
stormwater events that did initiate on weekend days or inside 72-hour period since the last
stormwater event. Therefore, this report is submitted as a formal notification of the NO FLOW
conditions at the site for January 2021.
Effective January 21, 2021, stormwater outfall SWO07 is also no longer in Tier 2 status as reported
analytical results have remained below corresponding permit benchmarks for three consecutive
monitoring events. Additionally, SWO08 remains in Tier 3 status for four intermittent TSS values
reported outside the benchmark range within the permit cycle.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Sincerely,
Rick R. Roper
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION
Marshall Steam Station
8320 East NC Highway 150
Terrell,NC 28682
be w/attachment: Scott la Sala
Robert Wylie
File: CCP EHS
UPS Tracking Number IZ8955X40394441813 Raleigh Central Office
www.duke-energy.com

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2021
(This monitoring report shall be received by the Division no later than 30 days from
the date the facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S)Staff PHONE NO.[phone]
CERTIFIED LABORATORY(S)Duke Energy of the Carolinas,LLC Lab#248
SIGNATURE OF PERMITTEE OR DESIGNEE
REQUIRED ON PAGE 2.
Part A: Specific Monitoring Requirements
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
moldd/ r inches m
SW008 NO FLOW - --- ---
Samples were not collected from stormwater outfall SW008 during January 2021 as a result to NO FLOW conditions.
Form SWU-247,last revised 21212012
Page 1 of 2

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Does this facility perlorm Vehicle Maintenance Activities using more than 55 gallons of new motor oil per month?—yes X no
(if yes,complete Part B)
Part B: Vehicle Maintenance Activity Monitoring Requirements
Outfall Date 50050 00556 00530 00400
No. Sample Total Flow Total Oil& Grease Non-polar Total pH New Motor
Collected (if applicable) Rainfall (if appl.) O&G/TPH Suspended Oil Usage
(Method 1664 Solids
SGT-HEM),if
appl.
tno/dd/ yr M(11 inches In m unit al/nuo
STORM EVENT CHARACTERISTICS: Mail Original and one copy to:
Division of Water Quality
Date NO FLOW Attn: Central Files
Total Event Precipitation(inches): NA 1617 Mail Service Center
Event Duration (hours): (only if applicable—see permit.) Raleigh,North Carolina 27699-1617
(if more than one storm event was sampled)
Date
Total Event Precipitation(inches):
Event Duration(hours): (only if applicable—see permit.)
"I certify,under penalty of law,that this document and all attachments were prepared under my direction or supervision in accordance with a
system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person
or persons who manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the
best of my knowledge and belief,true,accurate,and complete. I am aware that there are significant penalties for submitting false information,
includ�'j"he possibility of fines and imprisonment for knowing violations."
r z 24- z,�
(Signature of Permittee) (D te)
Form SWU-247, last revised 2/2/2012
Page 2 of 2

r� DUKE DUKE ENERGY CORPORATION
ENERGY. Marshall Steam Station
8320 Fast NC Highway 150
Terrell, NC 28682
January 21, 2021
NC Dept. of Environmental Quality
Attention: Central Files FEB
Division of Water Resources 2Q21
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548 — Catawba County
Year 6 Period 1 - Semi-Annual Monitoring Results
Dear Sir or Madam:
In accordance with Part lll, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of
the Year 6 - Period 1 stormwater monitoring is attached.
Samples were collected from stormwater outfalls SW002, SW003, SW007, SW008, SW011,
SW012, SW022 and SW025 on December 20, 2020, and the corresponding stormwater DMR for
this monitoring event is attached. Outfall 012A is reported as NO FLOW for the December 2020
monitoring event as it has been removed, as discussed with NCDEQ, due to regrading activities
within the drainage collection area. No permit benchmarks were exceeded during this monitoring
event.
Results reported indicate that SWO07 has satisfied requirements of Tier 2 conditions with three
consecutive monitoring events reported below corresponding benchmarks. Outfall SWO08
remains in Tier 3 status due to four intermittent TSS values being reported outside the benchmark
range within the permit cycle. The Tier 3 status will be removed upon receipt of the new permit
currently under review.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Sincerely,
Rick R. Roper
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION
Marshal!Steam Station
8320 East NC Highway 150
Terrell,NC 28682
be w/attachment: Scott La Sala
Robert Wylie
File: CCP EHS
UPS Tracking Number 1Z8955X40393201655 Raleigh Central Office
www.duke-energy.com

STORM WATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED IIURING CALENDAR YEAR: 21120
(This monitoring report shall be received by the Division no later than 30 days from the date the
facility receives the sampling results from the laboratory.)
FACILITY NA\IE Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S) Scott LaSala/Duke Analytical Laboratory Services SIGNATURE OF I(800)777.989%
CERTIFIED LABORATORY(S) Duke Enerp_v Lab#248
Pare Huntersville Office Lab#
Shealy Environmental Services,Inc. Lab#329 SIGNATURE OF PERMITTEE OR DESIGNEE
REQUIRED ON PAGE 3
Part A:Specific Monitoring Requirements
Outrall bate 51M140 00" 01077 01002 01022 01012 01027 01034
No. Sample
Collected
Total Rainfall Total Flow(if pH Silver,Total(as Arsenic.Total(as Boren.Total(as Beryllium.Total Cadmium.Total Chromium.Total
app.) A As B as Be as Cd us Cr
inches MG unit m W I. m L m L m L mgfL mWL
mdddlvr inches \IG unit mgfL mg1l, m m m m L
S► O02 12/20/2020 0.29 N/A 7.6
SW003 l2/20/2020 0.29 N/A 7.8
SWO07 12/20I2020 0.29 N/A 7.2 <0.0(H12 <0.001 <0.05 <0.001 <0.001 <0.00I
SWO08 12/20/2020 0.29 N/A 7.3
Swill] I2(2012020 0.29 N/A 7.2 <0.001 <0.001
SW012 12/20/2020 10.29 1 N/A 17.7
S%1'HI2,1 INO FLOW I I N/A
SW022 112J20120211 10.29 1 N/A 17.5
SWO25 12/20120211 111.29 1 NIA 17.6
REC�-zI',/F:F..•
Form SWU-247,last revised 9/19/2018
Permit Numher NCSOOOS48 Page I of 3

Outfall Date 01042 01067 01051 01097 01147 01059 01092 71900 C0530
No. Sample
Collected
Copper,Total(as Nickel,Total(as Lead,Total(as Antimony,Total Selenium,Total Thallium,Total Zinc,Total(as Zn)Mercury,Total Solids,Total
Cu) Ni) Ph) (as Sb) (as Se) (as Ti) Method 1631 E Suspended-
Concentration
mo/dd/ r m mWL mgIL mgIL m m m n m
SWO02 12/20/2020 4.1
SWO03 12/20/2020 5.7
SWO07 12/20/2020 0.00254 0.004 <0.001 <0.001 <0.001 <0.0002 0.096 3.13 7.6
SWo08 12/20/2020 3.8
Swol l 12/20/2020 <0.001 0.069 99
SWO12 12aO/2020 15
SWO12A NO FLOW
SWO22 12/20/2020 114
SWO25 12/20/2020 13.3
Outfall Date 34671 39488 39492 39496 39500 39504 39508 00556
No. Sample
Collected
PCB-1016 PCB-1221 PCB-1232 PCB-1242 PCB-1248 PCB-1254 PCB-1260 Oil&Grease
Arochlor 1016 Arochlor 1221 Arochlor 1232 Arochlor 1242 Arochlor 1248 Arochlor 1254 Arochlor 1260
mo/dd/r UgA u9A u u ugA u u m L
S WO02 12/20/2020
S Wo03 12/20/2020
SWO07 12/20/2020 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 <5
S WO08 12/20/2020
Swore 12/20/2020
S Wo12 12/2012020
SWO12A NO FLOW
S W022 12/20/2020
swo25 12/20/2020
Avg-Average of primary and duplicate Mercury,Total Method 1631 E samples(3.11 ngfl and 3.15 ng/l=3.13 ng/L).
Form SWU-247,last revised 9/19/2018
Permit Number NCSW0548
Page 2 of 3

Part B;Vehicle Maintenance Activity Monitoring Requirements
Out€all Date 50050 00400 00530 00556
No. Sample Total Rainfall Total Flow(if pH Total Suspended Oil&Grease(if Non-polar New Motor Oil
Collected applicable) Solids appl.) O&G/TPH Usage
(Method 1664
mg l m gallma
mdddlvr inches MG unit m m Jl m ga1/mo
STORM EVENT CHARACTERISTICS:
Mail Original and one copy to:
Date 12.20.2020 Division of Water Quality
Total Event Precipitation(inches): 0.29 Attn:Central Files
Event Duration(hours): (only if applicable—see permit.) 1617 Mail Service Center
Raleigh,North Carolina 27699-1617
(if more than one storm even)was sampled)
Date
"total Event Precipitation(inches);
Event Duration(hours): (only if applicable—see permit.)
"I certify,under penalty of law,Ihot this document anti all attachments were prepared under my direction or supervision in accordance with a system
designed to assure that qualified personnel properly gather and evaluate the information submitted.Razed on my inquiry of the person or persons who
manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the best of my knowledge and belief,
true,accurate,and complete.I ant aware that there are significant penalties for submitting false information,including the possibility of fines and
impri me for kn 'ing vi a ons
(Signal re o ermt ee) (Date)
Permit Member NC5000548
Form SWU-247,last revised 9/19/2018
Page 3 of 3

DUKE DUKE ENERGY CORPORATION
ENERGY. Marshall Steam Station
8320 East NC Highway 150
Terrell, NC 28682
December 16, 2020
JAN d 4 2021
NC Dept. of Environmental Quality
Attention: Central Files �'EPSTFti1L i-ILE�
Division of Water Resources DVVR SECTION
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548 — Catawba County
Year 5 -Tier II Monthly Sampling Results
Dear Sir or Madam:
In accordance with Park III, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of
the Tier II monthly sampling is attached.
Representative samples were not collected from SWO07 or SWO08 during November 2020
because of NO FLOW conditions at the facility, including stormwater events not initiating during
daylight hours or stormwater events that did initiate on weekend days or inside 72-hour period
since the last stormwater event. Therefore, this report is submitted as a formal notification of the
NO FLOW conditions at the site for November 2020.
Currently SWO07 remains in Tier 2 status for two consecutive values for copper outside the permit
benchmark range. Additionally, SWO08 remains in Tier 3 status for four intermittent TSS values
reported outside the benchmark range within the permit cycle.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Sincerely,
4
Rick R. Roper
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION
Marshall Steam Station
8320 East NC Highway 150
Terrell,NC 28682
be w/attachment: Scott La Sala
Robert Wylie
File: CCP EHS
UPS Tracking Number 1Z8955X40390659284 Raleigh Central Office
www.duke-energy.com

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2020
(This monitoring report shall be received by the Division no later than 30 days from
the date the facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S)Staff PHONE NO.NN 777-9898
CERTIFIED LABORATORY(S)Doke Energy of the Carolinas,LLC Lab#248
SIGNATURE OF PERMITTEE OR DESIGNEE
REQUIRED ON PAGE 2.
Part A: Specific Monitoring Requirements
Outtall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended -
Concentration
mo/dd/ r inches m
MV007 NO FLOW --- --- ---
REOPIVED
Outfall Date 00400 C0530 JAN 04 2021
No. Sample Total pH Solids,Total ;[1-4-{i FILE5
Collected Rainfall Suspended- DWR SECTION
Concentration
mo/dd/ r inches m
SW1108 NO FLOW I --- --- ---
Samples were not collected from stormwater outfall SWO07 and SWO08 during November 2020 as a result to NO FLOW conditions.
Form SWU-247,last revised 21212012
Page I of 2

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Does this facility perform Vehicle Maintenance Activities using more than 55 gallons of new motor oil per month?—yes X no
(if yes,complete Part B)
Part B:Vehicle Maintenance Activity Monitoring Requirements
Outfall Date 50050 00556 00530 00400
No. Sample Total Flow Total Oil &Grease Non-polar Total pH New Motor
Collected (if applicable) Rainfall (if appl.) O&G/TPH Suspended Oil Usage
(Method 1664 Solids
SGT-HEM),if
appl.
moldd/ r MG inches m mg/l unit al/mo
STORM EVENT CHARACTERISTICS: Mail Original and one copy to:
Division of Water Quality
Date NO FLOW Attn: Central Files
Total Event Precipitation(inches): NA 1617 Mail Service Center
Event Duration (hours): (only if applicable—see permit.) Raleigh,North Carolina 27699-1617
(if mitre than one storm event was sampled)
Date
Total Event Precipitation(inches):
Event Duration(hours): (only if applicable—see permit.)
"I certify,under penalty of law,that this document and all attachments were prepared under my direction or supervision in accordance with a
system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person
or persons who manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the
best of my knowledge and belief,true,accurate,and complete. 1 am aware that there are significant penalties for submitting false information,
including the pos ility of fines and imprisonment for knowing violations."
1,;Z !�
(Sig ature of Permitte (Date)
Form SWU-247,last revised 2IM012
Page 2 of 2

DUKE
KE DUKE ENERGY CORPORATION
ENERGY. Marshall Steam Station
8320 East NC Highway 150
Terrell, NC 28682
November 19, 2020
NC Dept. of Environmental Quality �1, ZOZ�
Attention: Central Files
Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548 — Catawba County
Year 5 -Tier II Monthly Sampling Results
Dear Sir or Madam:
In accordance with Part III, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of
the Tier II monthly sampling is attached.
Representative samples were not collected from SWO07 or SWO08 during October 2020 because
of NO FLOW conditions at the facility, including stormwater events not initiating during daylight
hours or stormwater events that did initiate on weekend days or inside 72-hour period since the
last stormwater event. Therefore, this report is submitted as a formal notification of the NO FLOW
conditions at the site for October 2020.
Currently SWO07 remains in Tier 2 status for two consecutive values for copper outside the permit
benchmark range. Additionally, SWO08 remains in Tier 3 status for four intermittent TSS values
reported outside the benchmark range within the permit cycle.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Sincerely,
A
Rick R7Rper
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION
Marshall Steam Station
8320 East NC Highway 150
Terrell,NC 28682
be w/attachment: Scott La Sala
Robert Wylie
File: CCP EHS
UPS Tracking Number 1Z8955X40393854183 Raleigh Central Office
www.duke-energy.com

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit NILmher NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2020
(This monitoring report shall be received by the Division no later than 30 days from
the date the facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLES)Staff PHONE NO.[phone]
CERTIFIED LABORATORY(S)Duke Energy of the Carolinas,LLC Lab#248
SIGNATURE OF PERMITTEE OR DESIGNEE
RE_ UQ IRED ON PAGE 2.
Part A: Specific Monitoring Requirements
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/dd/ r inches m
SWO07 NO FLOW --- i --- ---
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
molddl r inches m
SWO08 NO FLOW I --- --- ---
Samples were not collected from stormwater outfall SWO07 and SWO08 during October 2020 as a result to NO FLOW conditions.
Form SWU-247, last revised 21212012
Page I of 2

STORMWATER DISCHARGE OUTFALL(SDO) -
MONITORING REPORT
Does this facility perform Vehicle Maintenance Activities using more than 55 gallons of new motor oil per month?_yes X no
(if yes,complete Part B)
Part B:Vehicle Maintenance Activity Monitoring Requirements
Outfall Date 50050 00556 00530 00400
No. Sample Total Flow Total Oil&Grease Non-polar Total pH New Motor
Collected (if applicable) Rainfall (if appl.) O&G/TPH Suspended Oil Usage
(Method 1664 Solids
SGT-HEM),if
a 1.
mo/dd/ r MG inches m m unit al/mo
STORM EVENT CHARACTERISTICS: Mail Original and one copy to:
Division of Water Quality
Date NO FLOW Attn: Central Files
Total Event Precipitation(inches): NA 1617 Mail Service Center
Event Duration(hours): (only if applicable—see permit.) Raleigh,North Carolina 27699-1617
(if more than one storm event was sampled)
Date
Total Event Precipitation(inches):
Event Duration(hours): (only if applicable—see permit.)
"I certify,under penalty of law,that this document and all attachments were prepared under my direction or supervision in accordance with a
system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person
or persons who manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the
best of my knowledge and belief,true,accurate,and complete. I am aware that there are significant penalties for submitting false information,
including the possibility of fines and imprisonment for knowing violations."
J
(Signatu of Perm! e) (Date)
Form SWU-247,last revised 2/12012
Page 2 of 2

� DUKE DUKE ENERGY CORPORATION
f
ENERGY. Marshall Steam Station
8320 East NC Highway 150
Terrell, NC 28682
October 26, 2020
NC Dept. of Environmental Quality RECF1 !7 r
Attention: Central Files NOV
Division of Water Resources
1617 Mail Service Center GE�v tom'`'- 1E5
Raleigh, NC 27699-1617 DVVR SE-CTIONt
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548 — Catawba County
Year 5 -Tier 11 Monthly Sampling Results
Dear Sir or Madam:
In accordance with Part III, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of
the Tier II monthly sampling is attached.
Representative samples were not collected from SWO07 or SWO08 during September 2020
because of NO FLOW conditions at the facility, including stormwater events not initiating during
daylight hours or Stormwater events that did initiate on weekend days or inside 72-hour period
since the last stormwater event. Therefore, this report is submitted as a formal notification of the
NO FLOW conditions at the site for September 2020.
Currently SW007 remains in Tier 2 status for two consecutive values for copper outside the permit
benchmark range. Additionally, SWO08 remains in Tier 3 status for four intermittent TSS values
reported outside the benchmark range within the permit cycle.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Sin ely,
Rick R. Roper
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION
Marshal!Steam Station
8320 East NC Highway 150
Terrell,NC 28682
be w/attachment: Scott La Sala
Robert Wylie
File: CCP EHS
UPS Tracking Number 1Z8955X40396917583 Raleigh Central Office
www.duke-energy.com

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2020
(This monitoring report shall be received by the Division no later than 30 days from
the date the facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S)Staff PHONE NO. [phone]
CERTIFIED LABORATORY(S)Duke Energy of the Carolinas LLC Lab#248
SIGNATURE OF PERMITTEE OR DESIGNEE
REQUIRED ON PAGE 2.
Part A: Specific Monitoring Requirements
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/dd/ r inches m
SWO07 NO FLOW ---
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended -
Concentration
mo/dd/ r inches m L
SWO08 NO FLOW --- -- ---
Samples were not collected from stormwater outfall SWO07 and SWO08 during September 2020 as a result to NO FLOW conditions.
Form SWU-247, last revised 2IM012
Page I of 2

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Does this facility perform Vehicle Maintenance Activities using more than 55 gallons of new motor oil per month?_yes X no
(il'yes, complete Part B)
Part B: Vehicle Maintenance Activity Monitoring Requirements
Outfall Date 50050 00556 00530 00400
No. Sample Total Flow Total Oil&Grease Non-polar Total pH New Motor
Collected (if applicable) Rainfall (if appl.) O&G/TPH Suspended Oil Usage
(Method 1664 Solids
SGT-HEM),if
appl.
mo/dd/ r MC inches Me m unit gal/1110
STORM EVENT CHARACTERISTICS: Mail Original and one copy to:
Division of Water Quality
Date NO FLOW Attn: Central Files
Total Event Precipitation(inches): NA 1617 Mail Service Center
Event Duration(hours): (only if applicable—see permit.) Raleigh,North Carolina 27699-1617
(if more than one storm event was sampled)
Date
Total Event Precipitation(inches):
Event Duration(hours): (only if applicable—see permit.)
"I certify,under penalty of law,that this document and all attachments were prepared under my direction or supervision in accordance with a
system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person
or persons who manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the
best of my knowledge and belief,true,accurate,and complete. I am aware that there are significant penalties for submitting false information,
including the possibility of fines and imprisonment for knowing violations."
J r�
(Signature of Permitt (Dat )
Form SWU-247,last revised 21212012
Page 2 of 2

eft DUKE DUKE ENERGY CORPORATION
ENERGY Marsha!!Steam Station
8320 East NC Highway 150
Terrell, NC 28662
September 28, 2020
.E--
OCT 05 zo o
NC Dept. of Environmental Quality _
Attention. Central Files
Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1 6 1 7
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548 — Catawba County
Year 5 - Tier II Monthly Sampling Results
Dear Sir or Madam:
In accordance with Part III, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of
the Tier II monthly sampling is attached.
Representative samples were not collected from SWO07 or SWO08 during August 2020 because of
NO FLOW conditions at the facility, including stormwater events not initiating during daylight hours
or stormwater events that did initiate on weekend days or inside 72-hour period since the last
stormwater event. Therefore, this report is submitted as a formal notification of the NO FLOW
conditions at the site for August 2020.
Currently SWO07 remains in Tier 2 status for two consecutive values for copper outside the permit
benchmark range. Additionally, SWO08 remains in Tier 3 status for four intermittent TSS values
reported outside the benchmark range within the permit cycle.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Sincerely,
a___,
� &tw-
Rick R. Roper
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION
Marshal!Steam Station
8320 East NC Highway 150
Terre!!,NC 28682
be w/attachment: Scott La Sala
Robert Wylie
File: CCP EHS
UPS Tracking Number 1Z8955X40391857728 Raleigh Central Office
www.duke-energy.com

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2020
(This monitoring report shall be received by the Division no later than 30 days from
the date the facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S)Staff PHONE NO.[phone]
CERTIFIED LABORATORY(S)Duke Energy of the Carolinas.,LLC Lab#248
SIGNATURE OF PERMITTEE OR DESIGNEE
REQUIRED ON PAGE 2.
Part A: Specific Monitoring Requirements
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/ddl r inches m
SW007 NO FLOW ---
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/dd/ r inches m
SWO08 NO FLOW
Samples were not collected from stormwater outfall SW007 and SWO08 during August 2020 as a result to NO FLOW conditions.
OCT 05 2020
Form SWU-247, last revised 21212012
Page I of 2

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Does this facility perform Vehicle Maintenance Activities using more than 55 gallons of new motor oil per month?—yes X no
(if yes,complete Part B)
Part B: Vehicle Maintenance Ac ivity Monitoring Requirements
Outfall Date 50050 00556 00530 00400
No. Sample Total Flow Total Oil&Grease Non-polar Total pH New Motor
Collected (if applicable) Rainfall (if appl.) O&G/TPH Suspended Oil Usage
(Method 1664 Solids
SGT-HEM),if
a 1.
mo/dd/ r MG inches m=/l m unit al/mo
STORM EVENT CHARACTERISTICS: Mail Original and one copy to:
Division of Water Quality
Date NO FLOW Attn: Central Files
Total Event Precipitation(inches): NA 1617 Mail Service Center
Event Duration(hours): (only if applicable—see permit.) Raleigh.North Carolina 27699-1617
(if more than one storm event was sampled)
Date
Total Event Precipitation(inches):
Event Duration(hours): (only if applicable—see permit.)
"I certify,under penalty of law,that this document and all attachments were prepared under my direction or supervision in accordance with a
system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person
or persons who manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the
best of my knowledge and belief,true,accurate,and complete. I am aware that there are significant penalties for submitting false information,
possibility of fines and imprisonment for knowing violations."
including the
C .
(Signature of ermitte (Date)
Form SWU-247, last revised 21212012
Page 2 of 2

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2020
(This monitoring report shall be received by the Division no later than 30 days from
the date the facility receives the sampling results from the laboratory.)
F'AC'1LITY NAME Marshall Steam Station ('01!NTY Catawba
PERSON COLLECTING SAMPLE(S) Stuff PHONE NO. l811t!)777-98jJkS
CERTIFIED LABORATORYiS)Duke Enerz► of the Carolinas, LLC Lah#248
SIGNATURE OF PERMITTEE OR DESIGNEE
REULtlRED ON PAGE 2.
Part A: Specific Monitoring Requirements
Uutfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/dd/vr inches m L
L5W007 NO FLOXV --- --- ---
Outfall Date 00400 COti30
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/ddl r inches m L
k-wooi NO FLOW --- - ---
Samples +ere not collected from stormwater outfull SWO07 and SWIMS during August 2020 as a result to NO FLO"' conditions.
Foriii SWU-247, la.%r revisrai 12J.?W2
Page I o '

STORMWATER DISCHARGE OUTI;ALL (SDO1
MONITORING REPORT"
fh,e. This facilit) perfOrn3 N eliwle Maintenance Asti\ilieti usin�o more than 55 gi Ions of new motor oil per month'! NUS X 11u
iI yeti. Cu1111)lete Purl B)
Part B: Vehicle'Maintenance Activity Monitoring Requirements
Outfall Date 50051) 00556 00530 00400
No. Sample Total Flow Total Oil & Grease Non-polar Total pH New Motor
Collected of applicable) Rainfall (if appl.) O&G/TPH Suspended Oil Usage
(Method 1664 Solids
SCT-HEM),if
appl.
mo/dd/yr MG inches m l m /I unit alimo
ST(1RXI EVENT CHARACTERISTICS: ~Mail Original and one copy to:
Divi ion of Water Quality
Date No FLOW Attu: Central Files
Total Event Precipitation (inches): NA 1617 Mail Service Center
Fvent Duration{hours►: -- . only if applicable- ,ee permit.f Ralcich, Norili C artilina 27649-1617
t it inure than tine ,iurn+ cN c nt %kati,atnple11)
Date
Total Event Precipitation finches): T
Event Duration (hoursl: _- -� <<,nl% 11'applieahIe - see perniit.)
"1 certify,under penalty of law,that this document and all attachments were prepared under my direction or supervision in accordance with a
tivstem designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry or the person
or persons who manage the system,or those persons directly responsible for gathering the information, the information submitted is,to the
best of my knowledge and belief,true,accurate,and complete. I am aware that there:ere significant penalties for submitting false information,
including the possibilitl of fines and imprisonment for knowing violations."
1 � �
�signatureaI ermittc (Date)
1=011r SWU-47,last revised 2/'/:'012
Page 2 of 2

DUKE Ma E Steam SRGY
tatin
ENERGY, 8320 East NC Highway 150
Terrell, NC 28682
August 26, 2020 ►
SEP 0 8 202D
NC Dept. of Environmental Quality
Attention: Central Files �;jrG1 ION
Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548 — Catawba County
Year 5 - Tier II Monthly Sampling Results
Dear Sir or Madam:
In accordance with Part III, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of
the Tier II monthly sampling is attached.
Representative samples were not collected from SWO07 or SW008 during July 2020 because of
NO FLOW conditions at the facility, including stormwater events not initiating during daylight hours
or stormwater events that did initiate on weekend days or inside 72-hour period since the last
stormwater event. Therefore, this report is submitted as a formal notification of the NO FLOW
conditions at the site for July 2020.
Currently SWO07 remains in Tier 2 status for two consecutive values for copper outside the permit
benchmark range. Additionally, SWO08 remains in Tier 3 status for four intermittent TSS values
reported outside the benchmark range within the permit cycle.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Sincerely,
Rick R. Roper
General Manager Ili
Marshall Steam Station
attachment
www.duke-energy.com

STORMWATER DISCHARGE OUTFALL iSDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2021I
(This monitoring report shall be received by the Division no later than 30 days from
the date the facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S)Staff PHONE NO. (8110)777-9898
CERTIFIED LABORATORY(S) Duke Energy of the Carolinas, LLC Lab#248
SIGNATURE OF PERMITTIE OR DESIGNEE
REUUIRF❑ON PAGE 2.
Part A: Specific Monitoring Requirements
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/dd/ r inches m /L
SWO07 NO FLOW --- --- ---
Outfall Date 00400 C0530
Nib. Sample 'Total pH Solids,Total
Collected Rainfall Suspended -
Concentration
moldd/ r inches m L
SW008 NO FLOW I --- --- ---
Samples were not collected from stormwater outfult SW007 and SW008 during July 2020 as at result to NO FLOW conditions.
Form SWU-247, last revised 2/212012
Pugs I of

STORMWATER DISCHARGE OUTFALL (SDO)
MONITORING REPORT
D,)e, this facility perform Vehicle Maintenance Activities using more than 55 gallons of new motor oil per month!� reti X no
ail complete fart B)
Part It: Vehicle Maintenance Activity Monitoring Res uirement%
Outfall Date 1 500541 00556 00530 00400
No. Sample Total Flow Total Oil &Grease Non-polar Total pH New Motor
Collected (if applicable) Rainfall if appl.) O&G/TPH Suspended Oil Usage
(Method 1664 Solids
SGT-HEM),if
a I.
mo/dd/yr MG inches m W 1 MgA t:nit gallmo
STORM EVENT CHARACTERISTICS: Mail Original and one copy to:
Division c)f Water Quality
Date NO FLOW Attn: Central File,
Total Event Precipitation(inches): NA 1617 Mail Seri ice Center
Event Duration(hours): — (only if applicable— ties permil.) Raleigh. North Carolina 27099-1617
iif more than one storm event was sampled)
Date_
Total Event Precipitation(inches):
Event Duration(hours): _ (only if applicable—see permit.)
"I ccrtifv,under penalty of law,that this document and all attachments were prepared under my direction or supervision in accordance with a
system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person
or persons who manage the system,or those persons directly responsible for gathering;the information,the information submitted is,to the
best of my knowledge and belief,true,accurate,and complete. I am aware that there are significant penalties for submitting false information,
in idin the possibility of fines and imprisonment for knowing violations."
(sign--- of Permittee (Date)
Form SW U-2 47. lust revised 2/2n012
Paae 2 of 2

DUKE DUKE ENERGY CORPORATION
ENERGY.. Marshall Steam Station
8320 East NC Highway 150
Terrell, NC 28682
July 13, 2020
JUL 2 0 2020
NC Dept. of Environmental Quality CSN0Tk/.4
Att
Divisione l of Water Files Resources Dl�', `'ECDON
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548—Catawba County
Year 5 - Tier II Monthly Sampling Results
Dear Sir or Madam:
In accordance with Part 111, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of
the Tier II monthly sampling is attached.
Representative samples were not collected from SWO07 or SWO08 during June 2020 because of
NO FLOW conditions at the facility, including stormwater events not initiating during daylight hours
or stormwater events that did initiate on weekend days or inside 72-hour period since the last
stormwater event. Therefore, this report is submitted as a formal notification of the NO FLOW
conditions at the site for June 2020.
Currently SWO07 remains in Tier 2 status for two consecutive values for copper outside the permit
benchmark range. Additionally, SWO08 remains in Tier 3 status for four intermittent TSS values
reported outside the benchmark range within the permit cycle.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Sinc ely,
Rick R. Roper
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION
Marshall Steam Station
8320 East NC Highway 150
Terrell,NC 28662
be w/attachment: Scott la Sala
Robert Wylie
File: CCP EHS
UPS Tracking Number 1Z8955X40396869886 Raleigh Central Office
www.duke-energy.com

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2020
(This monitoring report shall be received by the Division no later than 30 days from
the date the facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S)Staff PHONE NO.[phone]
CERTIFIED LABORATORY(S)Duke Ener v of the Carolinas LLC Lab#248
SIGNATURE OF PERMITTEE OR DESIGNEE
Part A: Specific Monitoring Requirements REQUIRED ON PAGE 2.
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/dd/ r inches m L
SWO07 NO FLOW --- --- .__
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/ddl r inches m IL
SWO08 NO FLOW --- _-- ---
Samples were not collected from stormwater outfall SWO07 and SWO08 during June 2020 as a result to NO FLOW conditions.
Form SWU-247, last revised 21212012
Page 1 of 2

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Does this facility perform Vehicle Maintenance Activities using more than 55 gallons of new motor oil per month?_yes X no
(if yes,complete Part B)
Part B: Vehicle Maintenance Activity Monitorin Requirements
Outfall Date 50050 00556 00530 00400
No. Sample Total Flow Total Oil & Grease Non-polar Total pH New Motor
Collected (if applicable) Rainfall (if appl.) O&GITPH Suspended Oil Usage
(Method 1664 Solids
SGT-HEM),if
appl.
mo/dd/ r MG linches rugn m g/i unit al/mo
STORM EVENT CHARACTERISTICS: Mail Original and one copy to:
Division of Water Quality
Date NO FLOW Attn: Central Files
Total Event Precipitation(inches): NA 1617 Mail Service Center
Event Duration(hours): (only if applicable—see permit.) Raleigh, North Carolina 27699-1617
(if more than one storm event was sampled)
Date
Total Event Precipitation (inches):
Event Duration(hours): (only if applicable—see permit.)
"I certify,under penalty of law,that this document and all attachments were prepared under my direction or supervision in accordance with a
system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person
or persons who manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the
best of my knowledge and belief,true,accurate,and complete. I am aware that there are significant penalties for submitting false information,
includi he possiz Zes and imprisonment for knowing violations."
3 zo zo
(Signature of Permittee) (Date)
Form SWU-247, last revised 21212012
Page 2 of 2

DUKE DUKE ENERGY CORPORATION
;� ENERGY. Marshall Steam Station
8320 East NC Highway 150
Terrell, NC 28682
June 25, 2020 _
a '
�� .
JUN 2 9 2020
NC Dept. of Environmental Quality
Attention: Central Files
Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548 — Catawba County
Year 5 - Tier II Monthly Sampling Results
Dear Sir or Madam:
In accordance with Part III, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfail (SDO) monitoring reports containing results of
the Tier II monthly sampling is attached.
Representative samples were not collected from SWO07 or SWO08 during May 2020 because of
NO FLOW conditions at the facility, including stormwater events not initiating during daylight hours
or stormwater events that did initiate on weekend days or inside 72-hour period since the last
stormwater event. Therefore, this report is submitted as a formal notification of the NO FLOW
conditions at the site for May 2020.
Currently SWO07 remains in Tier 2 status for two consecutive values for copper outside the permit
benchmark range. Additionally, SWO08 remains in Tier 3 status for four intermittent TSS values
reported outside the benchmark range within the permit cycle.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Sincerely,
-Z 6olll
Ric R. Roper
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION
Marshall Steam Station
8320 East NC Highway 150
Terrell,NC 28682
be w/attachment: Scott La Sala
Robert Wylie
File: CCP EHS
UPS Tracking Number 1Z8955X40394583536 Raleigh Central Office
www.duke-energy.com

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2020
(This monitoring report shall be received by the Division no later than 30 days from
the date the facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S)Staff PHONE NO. (80U)777-9898
CERTIFIED LABORATORY(S)Duke Energy of the Carolinas,LLC Lab#248
SIGNATURE OF PERMITTEE OR DESIGNEE
REQUIRED ON PAGE 2.
Part A: Specific Monitoring Requirements
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/dd/ r inches m
SWO07 NO FLOW --- ---
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/dd/ yr inches m L
SW008 NO FLOW --- --» ---
Samples were not collected from stormwater outfall SWO07 and SWO08 during May 2020 as a result to NO FLOW conditions.
Form SWU-247, last revised 21212012
Page; I of 2

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Does this facility perform Vehicle Maintenance Activities using more than 55 Gallons of new motor oil per month?_yes X no
(if yes,complete Part B)
Part B: Vehicle Maintenance Activity Monitoring Requirements
Outfall Date 50050 00556 00530 00400
No. Sample Total Flow Total Oil & Grease Non-polar Total pH New r\lotor
Collected (if applicable) Rainfall (if appl.) O&G/TPH Suspended Oil Usage
(Method 1664 Solids
SGT-HEM),if
appl.
I F- moldd/ r MG inches m m unit aUmo_ I
STORM EVENT CHARACTERISTICS: Mail Original and one copy to:
Division of Water Quality
Date NO FLOW Attn: Central Files
Total Event Precipitation(inches): TiA 1617 Mail Service Center
Event Duration(hours): (only if applicable—see permit.) Raleigh,North Carolina 27699-1617
(if more than one storm event was sampled)
Date
Total Event Precipitation(inches):
Event Duration(hours); (only if applicable—see permit.)
"I certify,under penalty of law,that this document and all attachments were prepared under my direction or supervision in accordance with a
system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person
or persons who manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the
best of my knowledge and belief,true,accurate,and complete. I am aware that there are significant penalties for submitting false information,
including the possibility of fines and imprisonment for knowing violations."
'21 1/IdF � am (� - 2__
(Sig a ure of Persim tee (Date)
Form SWU-247,fast revised 21212012
Page 2 of 2

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DUKE DUKE ENERGY CORPORATION
ENERGY Marshall Steam Station
8320 East NC Highway 150
Terrell, NC 28682
May 26, 2020
NC Dept. of Environmental Quality
Attention: Central Files JUN r) 9 2020
Division of Water Resources CL:,-"
1617 Mail Service Center DIpJRcCTIdi,1
Raleigh, NC 27699-1617
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548 — Catawba County
Year 5 - Semi-Annual Monitoring Results
Dear Sir or Madam:
In accordance with Part III, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of
the Year 5 - Period 2 stormwater monitoring is attached.
Samples were collected from stormwater outfalls SW002, SW003, SW007, SW008, SW011,
SW012, SW022 and SW025 on April 23, 2020, and the corresponding stormwater DMR for this
monitoring event is attached. Outfall 012A is reported as NO FLOW for the April 2020 monitoring
event. No permit benchmarks were exceeded during this monitoring event. Currently SWO07
remains in Tier 2 status for two prior consecutive values for copper outside the permit benchmark
range. Additionally, SWO08 remains in Tier 3 status for four intermittent TSS values reported
outside the benchmark range within the permit cycle.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Since ,
Rick R. Roper
General Manager III
Marshall Steam Station
attachment
www.d u ke-e ne rgy.c o rn

DUKE ENERGY CORPORATION
Marshal!Steam Station
8320 East NC Highway 150
Terrell,NC 28682
be w/attachment: Scott La Sala
Robert Wylie
File: CCP EHS
UPS Tracking Number 1Z8955X40391569245 Raleigh Central Office
www.duke-energy.com

STORNINVATER DISCHARGE OUI'FALL(SDO)
NIONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2020
(This monitoring report shall be received by the Division no later than 30 days from the date the
facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COtTNTY Catawba
PERSON COLLECTING SAMPLE(S) La Sala/Marshall Field/Scott LaSaln/fluke Analvlic:d Laboralury Services PIIONE NO. (80Q)777-9898
CERTIFIED LABORATORY(S) Duke Energy Lab N
Shealy Environmental Sen ices,Inc. Lab 11 329
SIGNATURE OF PERMITTEE OR DESIGNEE
REQUIRED ON PAGE 3
Pin A:Specific Monitoring Requircn,cros
Oulfall Dal c 50051) 00400 01077 01002 01022 01012 01027 01034
No, Sam plc 'Fund Rainfall Total Flow(if pll Silver,Total(as Arsenic,Total(as Boron,Total(as Beryllium,Total Cadmium,Total Chromium,Total
Co0ected app.) Ag) As) D) (as Be) (as Cd) (as Cr)
nto/dd/yr inches MG unit tn /L m IL tvglL ne 1L m L in L
SNV002 4123/2020 NIA
SW003 4123/2020 0.49 NU 7A
SW004 4/23/2020 0.49 N/A 7.8
SW007 4/23/2020 0.49 N/A 7.3 <0.0002 cll.ulll <0,05 �0.001 c0.001 <(I.001
WOOS 4/23/2021) 0.49 N/A 7.2
S%VW l 4123f2020 0.49 NIA 7.1 <0.005 <0.005
SW012 4/23/2020 0.49 N/A 7.5
S1VU12A 4123/2020 No Flmv
S11'122 4R312020 0.49 N1A 7.5
SWfl24 4/23/2520 No now Oulfall not et constructed
SWOZ5 4/23/2020 0.49 IV'A 7,6
Outfall Date 01042 01067 01051 01097 01147 01059 01092 71900 CO530
No. Sample Copper,Total(as Nickel.Total(us Lead,Total(as Antimon),Total Selenium,Total Thallium,Total Zinc,Total(as 7.n)Mercury,Total Solids,Total
Collected Cu) Nil ph) (as Sit) (as Se) (as Ti) Method 1631 E Suspended-
Concentration
molddl yr m L ro L m /L m 1L m /L m 1L m /L v /L m /L
SWO02 4/2312020 5.6
SW003 4/23/2020 14
SWO04 4/23/2020
SWOU7 4/23/2020 0,00193 0.011178 <0.001 <0.001 <ll,llll I <0.0002 0.048 6.27 Avg. 5.6
WOOS 412312020 20
S1611011 4/23/2020 <0.03 0.051 21
SW012 4123/2020 G2
SW012A 4/23/2020 No Flow
SW022 4f2312020
34
SWU24 4/23/2020 No Flow Outfoll nut vet constructed
SW025 4/23/2020
l3
Permit Number NCSOCOS48 Form SWU-247,last revised 9/19/2018
Page 1 of 3

Outfatl Date 34671 394 39492 39496 39SO0 39504 39508 00556
No. Sample PCII-1016 PCW1221 PCB-1232 PCB-1242 PCB-1248 PCB-1254 PCB-1260 Oil&Grease
Collected (Arochlor 1016) (Arochlor 1221) (Arochlor 1232) (Arochlor 1242) (Arochlor 1248) (Arochlor 1254) (Arochlor 1260)
mo/dd/r u u UgIl u Uall u m L
SNV002 423/20I0
SW003 4/23/2020
SWOO4 4123/2020
SWO07 4/23/2020 <0.40 <0.40 <0.40 <0.40 <0.40 <0.40 <0.40 <5.0
SW008 423/2020
S%V011 41Z3/2020
SW012 4232020
SW012A 4232020 No Flow
SW022 423202O
SW024 4232020 No Flow Outfa0 not yet constructed
SW025 4/232020
Avg-Average of primary and duplicate Mercury,Total Method 1631 E samples(5.73 ngA and 6.81 ngfl=6.27 ng/L).
Form SWU-247,last revised 9/19/2018
Permit Number NCS000548 Page 2 of 3

Dues this facility perfunn Vehicle A{aituenance Activities using more than 55 gallons ofnew motur oil per monlh? Yes X no
(ifycs,complete Part B)
Part R:Vehicle Maintenance Activity Monitoring Requirements
Outfall Date 50050 00400 00530 00556
Nu. Sample Total Rainfall Total Flow(if pH Total Suspended Oil&Grease(if Won-polar New Motor Oil
Collected applicable) Solids appl.) O&GIPPII Usage
(Method 1664
SGT-HEM),if
appl.
molddlyr inches MC unit m n my/I 1111911 aUmo
STORM EVENT CHARACTERISTICS:
Mail Original and one copy to:
Date 0412312020 Division of Water Quality
Total Event Precipitation(inches): 0.49 Attn:Cenral Files
Event Duration(hours): 12 (only if applicable—see pemut.) 1617 Mail Service Center
Raleigh,North Carolina 27699-1617
(if more than One Sloan event was sampled)
Date
Total Event Precipitation(inches):
Event Duration(hours): (only if applicable—see permit.)
"I certify,under penalty of law,that this document and all attachments were prepared under Pity direction or supervision in accordance with a system
designed to assure that qualified personnel properly gather and evaluate the information submitted.Based on my inquiry of the person or persons who
manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the hest of my knowledge and belief,
true,occur e, d complete.1 am aware that there are significant penalties for submitting false information,including the possibility of fines and
imprisWn;7
' ions."
(Signature of Permittee) (Date)
Permit Number NC5000548 form SWU-247,last revised 9/19/2018
Page 3 of 3

DUKE - DUKE ENERGY CORPORATION
ENERGY. Marshall Steam Station
8320 East NC Highway 150
Terrell,NC 28682
April 14, 2020
APR 2 7 202
NC Dept. of Environmental Quality CENT- �'L€
Attention: Central Files DV�p S�CTIOE�
Division of Water Resources
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548— Catawba County
Year 5 -Tier III Monthly Sampling Results
Dear Sir or Madam:
In accordance with Part III, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of
the Tier II monthly sampling is attached.
Representative samples were not collected from SWO07 or SWO08 during March 2020 because of
NO FLOW conditions at the facility, including stormwater events not initiating during daylight hours
or stormwater events that did initiate on weekend days or inside 72-hour period since the last
stormwater event. Therefore, this report is submitted as a formal notification of the NO FLOW
conditions at the site for March 2020.
Currently SWO07 remains in Tier 2 status for two consecutive values for copper outside the permit
benchmark range. Additionally, SWO08 remains in Tier 3 status for four intermittent TSS values
reported outside the benchmark range within the permit cycle.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Si cerely,
L� &e0ov--
Rick R. Roper
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION
Marshall Steam Station
8320 East NC Highway 150
Terrell,NC 28682
be w/attachment: Scott La Sala
Robert Wylie
File: CCP EHS
UPS Tracking Number 1Z8955X40397906413 Raleigh Central Office
www.duke-energy.com

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2020
(This monitoring report shall be received by the Division no later than 30 days from
the date the facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S)Staff PHONE NO.[phone]
CERTIFIED LABORATORY(S) Duke Energy of the Carolinas,LLC Lab#248
SIGNATURE OF PERMITTEE OR DESIGNEE
REQUIRED ON PAGE 2.
Part A: Specific Monitoring Requirements
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/dd/ r inches m
SW007 NO FLOW --- --- ---
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/dd/ r inches m
5W008 NO FLOW I --- L --- ---
Samples were not collected from stormwater outfall SWO07 and SWO08 during March 2020 as a result to NO FLOW conditions.
Form SWU-247, last revised 21212012
Page 1 of 2

STORMWATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Does this facility perform Vehicle Maintenance Activities using more than 55 gallons of new motor oil per month?—yes X no
(if yes,complete Part B)
Part B: Vehicle Maintenance Activity Monitoring Requirements
Outfall Date 50050 00556 00530 00400
No. Sample Total Flow Total Oil & Grease Non-polar Total 141 New Motor
Collected (if applicable) Rainfall (if appl.) O&G/TPH Suspended Oil Usage
(Method 1664 Solids
SGT-HEM),if
appl.
mo/ddl r MG inches m=/I m unit gal/nw
STORM EVENT CHARACTERISTICS: Mail Original and one copy to:
Division of Water Quality
Date NO FLOW Attn: Central Files
Total Event Precipitation (inches): NA 1617 Mail Service Center
Event Duration(hours): (only if applicable—see permit.) Raleigh,North Carolina 27699-1617
(if more than one storm event was sampled)
Date
Total Event Precipitation(inches):
Event Duration(hours): (only if applicable—see permit.)
"I certify,under penalty of law,that this document and all attachments were prepared under my direction or supervision in accordance with a
system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person
or persons who manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the
hest of my knowledge and belief,true,accurate,and complete. I am aware that there are significant penalties for submitting false information,
including the 7ib es and imprisonment for knowing violations."
2-v2C
, i
(Sign ure of Permittee) (Date)
Form SWU-247, last revised 2/2/2012
Page 2 of 2

STORM WATER DISCHARGE OUTFALL(SDO)
MONITORING REPORT
Permit Number NCS000548 SAMPLES COLLECTED DURING CALENDAR YEAR: 2020
(This monitoring report shall be received by the Division no later than 30 days from
the date the facility receives the sampling results from the laboratory.)
FACILITY NAME Marshall Steam Station COUNTY Catawba
PERSON COLLECTING SAMPLE(S)Staff PHONE NO. 800 7777-9898
CERTIFIED LABORATORY(S)Duke Energy of the Carolinas LLC Lab#248
SIGNATURE OF PERMITTEE OR DESIGNEE
REQUIRED ON PAGE 2.
Part A: Specific Monitoring Requirements
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total R E lr'p P:I V E D
Collected Rainfall Suspended-
Concentration
moldd/ r inches P m L
SWO07 NO FLOW .__ CE RAL FILES
--- --- DWR SLECTION
Outfall Date 00400 C0530
No. Sample Total pH Solids,Total
Collected Rainfall Suspended-
Concentration
mo/dd/ r inches m
SW008 NO FLOW --- I ---
Samples were not collected from stormwater outfall SWO07 and SWO08 during February 2020 as a result to NO FLOW conditions.
Form SWU-247, last revised 21212012
Pa-e I of 2

STORMWATER DISCHARGE OUTFALL (SDO)
MONITORING REPORT
Does this facility perform Vehicle Maintenance Activities using more than 55 gallons of new motor oil per month?_yes X no
(if yes,complete Part B)
Part B: Vehicle Maintenance Activity Monitoring Requirements
Outfall Date 50050 00556 00530 00400
No. Sample Total Flow Total Oil&Grease Non-polar Total pH New Motor
Collected (if applicable) Rainfall (if appl.) O&GITPH Suspended Oil Usage
(Method 1664 Solids
SGT-HEM),if
appl.
molddly r MG inches mo MO unit al/mo
STORM EVENT CHARACTERISTICS: Mail Original and one copy to:
Division of Water Quality
Date NO FLOW Attn: Central Files
Total Event Precipitation(inches): NA 1617 Mail Service Center
Event Duration(hours): (only if applicable—see permit.) Raleigh, North Carolina 27699-1617
(if more than one storm event was sampled)
Date
Total Event Precipitation (inches):
Event Duration(hours): (only if applicable—see permit.)
"I certify,under penalty of law,that this document and all attachments were prepared under my direction or supervision in accordance with a
system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person
or persons who manage the system,or those persons directly responsible for gathering the information,the information submitted is,to the
best of my knowledge and belief,true,accurate,and complete. I am aware that there are significant penalties for submitting false information,
inclu ' g the pos ' ility of fines and imprisonment for knowing violations."
(Si nature of Permi tec (Date)
Form SWU-247, lust revised 21212012
Page 2 of 2

DUKE DUKE ENERGY CORPORATION
ENERGY. Marshall Steam Station
8320 East NC Highway 150
Terrell, NC 28682
RP.r:FIVE;D
March 25, 2020 h1-11t 0 6 ZKO
C.EfVO'I- rtiLl=ICES ���"':� A
Dl�R SECTION N
NC Dept. of Environmental Quality APR 0 6
Attention: Central Files
Division of Water Resources GEN-I k-ONL F14rES
1617 Mail Service Center DWG? SECTION
Raleigh, NC 27699-1617
Subject: Duke Energy Carolinas, LLC
NPDES Stormwater Discharge Monitoring Report for:
Marshall Steam Station - NCS000548 — Catawba County
Year 5 - Tier II Monthly Sampling Results
Dear Sir or Madam:
In accordance with Part III, E(2) of the above referenced NPDES Stormwater permit, the original
and one copy of the Stormwater Discharge Outfall (SDO) monitoring reports containing results of
the Tier II monthly sampling is attached.
Representative samples were not collected from SWO07 or SWO08 during February 2020 because
of NO FLOW conditions at the facility, including stormwater events not initiating during daylight
hours or stormwater events that did initiate on weekend days or inside 72-hour period since the
last stormwater event. Therefore, this report is submitted as a formal notification of the NO FLOW
conditions at the site for February 2020.
Currently SWO07 remains in Tier 2 status for two consecutive values for copper outside the permit
benchmark range. Additionally, SWO08 remains in Tier 3 status for four intermittent TSS values
reported outside the benchmark range within the permit cycle.
Please direct any correspondence or questions concerning the Marshall Steam Station NPDES
Stormwater Program to Robert Wylie at [phone].
Si rely,
a,e6pzo�
Rick R. Roper
General Manager III
Marshall Steam Station
attachment
www.duke-energy.com

DUKE ENERGY CORPORATION ,
Marshall Steam Station
8320 East NC Highway 150
Terrell,NC 28682
be w/attachment: Scott La Sala
Robert Wylie
File: CCP EHS
UPS Tracking Number 1Z8955X40390989365 Raleigh Central Office
www.duke-energy.com