NC0024406_More Information (Received)_20210513

�( DUKE Belews Creek Steam Station
C ENERGY 3195 Pine Hall Rd
Belews Creek, NC 27009
o:336.445.0644
f:336.445.0423
April 20,2021
Dr. Sergei Chernikov
North Carolina Division of Water Resources RECEIVED
WQ Permitting Section-NPDES
1617 Mail Service Center
Raleigh, NC 27699-1617 1 3 2021 •
NCDEQ/DWR/NPDES
Subject: Duke Energy, LLC.
Belews Creek Steam Station
NPDES Permit NC0024406
Dear Dr. Chernikov,
This letter and the attached materials are provided in support of Duke Energy Carolinas, LLC's(Duke
Energy)application to continue the thermalva
riance stated in the Belews Creek Steam Station (BCSS)
NPDES permit as required by condition A.(24.). The continuation of Duke Energy's thermal variance at
BCSS is based on the enclosed comprehensive
slue 316 a studies undertaken in acc
ordance O with permit
condition A. (24.).
Belews Lake was constructed for the express purpose of providing cooling water for BCSS. In accordance
with direction issued by the NC Utilities Commission,unit I began commercial operation in August 1974
and unit 2 in December 1975. BCSS operates under NPDES permit no. NC0024406. The initial permit
was issued by the State of North Carolina in 1970 prior to the development of the Clean Water Act
(CWA)and associated §316(a)requirements for a thermal variance. The initial permit granted BCSS a
temperature variance that stated daily average ambient water temperatures shall not exceed 32 °C at the
dam discharge as a result of BCSS operations.
North Carolina's Division of Water Resources(DWR) issued a NPDES permit in 2012, and stated in
Section A. (15.),
"The thermal variance granted by the State of North Carolina terminates on expiration of the NPDES
permit. Should the permittee wish a continuation of its thermal variance beyond the term of this permit,
reapplication for such continuation shall be submitted in accordance with 40 CFR Part 125, Subpart H
and Section 122.21 (1)(6)...The temperature analysis and the balanced and indigenous study plan shall
conform to the specifications outlined in 40 CFR Part 125 Subpart H and the Environmental Protection
Agency's(EPA)draft 316(a) Guidance Manual, dated 1977."
Upon review of the 2011-2015 BCSS 316(a)report submitted to the State in 2016, the North Carolina
Department of Environmental and Natural Resources(NCDENR)commented that the report did not
satisfy the 2012 permit requirements specified in Section A.(15.). To address these comments and
continue operating under a thermal variance,the current 2019 NPDES five-year permit for BCSS requests
in Section A. (24.)a one year comprehensive 316(a) Demonstration study, performed in accordance to
specifications in 40 CFR Part 125 Subpart H and the EPA's 1977 draft 316(a) Guidance Manual.

Duke Energy conducted one year of monitoring as outlined in the approved Study Plan and thus, is
submitting the report within 120 days of monitoring completion.
Results from the study found that current BCSS operations will ensure the survival, reproduction,
development, and growth of representative important species (RIS). Moreover,the BCSS thermal plume
has not blocked or inhibited access to any potential spawning habitat, spawning activities,or the
development of early juveniles of RIS. Despite warm water temperatures,the lake was found to have a
balanced and indigenous fish community.
If there are any questions, please contact either:
• Mr. Maverick Raber(Environmental Science Manager)980.875.2021, maverick.rabernduke-
enerj. .com
• Mr. Scott Fletcher(Environmental Science Manager)980.875.6014, scott.fletcheraduke-
enerev.com• Mr. Pierce Lawrence (Environmental Scientist I)336.552.7993, pierce.lawrence,c duke-
eneruv.com
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 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 offines and imprisonment for knowing violations.
Sincerely,
Michael Lanning
General Manager III