NC0003468_Approval_20220401 (2)

DocuSign Envelope ID: 4BD3DEAD-7215-4534-8C9D-41 FACB23015E
ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
RICHARD E. ROGERS, JR.
Director
NORTH CAROLINA
Environmental Quality
April 1, 2022
Terry Tuck
Duke Energy — Dan River Combined Cycle
(provided via email)
Subject: Biocide Use Review
Duke Energy — Dan River Combined Cycle
NPDES # NC0003468
Rockingham County
Dear Mr. Terry Tuck,
Duke Energy — Dan River Combined Cycle has requested approval of the below chemicals.
These products will be discharged from Outfall 001 and into the Dan River.
Product/Chemical
Approval / Comment
60% Ferric Sulfate/Ferralyte 8130
PENDING — Awaiting further data
25% Sodium Hydroxide
APPROVED
12.5% Sodium Hypochlorite
APPROVED (TRC testing permit parameter)
NalClear 7768
APPROVED
3D Traser 3DT187
APPROVED
Nalco 3DT098
APPROVED
38% Sodium Bisulfite
APPROVED
PERMATREAT PC-191T
APPROVED
Avista Riocide IS2
APPROVED
19% Aqueous Ammonia
APPROVED
Trisodium Phosphate
APPROVED
Rhodamine WT Liquid Dye
APPROVED
NALPREP IV
APPROVED
NORTH CAROLINADEQ
N
oep.m.m orEMr nment oN.i�
North Carolina Department of Environmental Quality I Division of Water Resources I Bio Lab
4401 Reedy Creek Road I 1621 Mail Service Center I Raleigh, North Carolina 27699-1621
919.743.8400

DocuSign Envelope ID: 4BD3DEAD-7215-4534-8C9D-41FACB23015E
Calculations predict the use of the above products, at the stated dosage rate, will not cause toxic
impacts to aquatic life in the receiving stream, the Dan River. Therefore, the use of this product
as an additive to the cooling tower blowdown, non -contact cooling water, and occasional
draining from other operational systems at the Duke Energy — Dan River Combined Cycle is
acceptable.
If you have any questions or concerns, please contact Zach Thomas at [phone] or
[e-mail].
Sincerely,
(—DocuSigned by:
C:.a,Moau
676E9F78241 C4B5...
Cindy Moore, Supervisor
Aquatic Toxicology Branch
Division of Water Resources, NCDEQ
Attachment: Biocide Spreadsheet
cc: Joyce Dishmon, Duke Energy (via email: [e-mail])
William Milam, Duke Energy (via email: William.MilamAduke-energy.com)
Gary Carroll, Duke Energy (via email: Gary.CarrollAduke-energy.com)
Charles Weaver, DWR (via email: [e-mail])
Jenny Graznek, WSRO (via email: [e-mail])
ATB Electronic File & Laserfiche
D_E
NORTH CAROLINA
gaparMeM of Environment,/quay
North Carolina Department of Environmental Quality I Division of Water Resources I Bio Lab
4401 Reedy Creek Road I 1621 Mail Service Center I Raleigh, North Carolina 27699-1621
919.743.8400