NC0003468_Approval_20240716

Docusign Envelope ID:7424A2E1-AA75-4A88-825B-2E871268EOC1
ROY COOPER
Governor
ELIZABETH S.BISEP, =�*
Secretary
RICHARD E.ROGEPS,,JR. NORTH CAROLINA
Director Environmental Quality
July 16,2024
To: Joyce Dishmon
Duke Energy
(via email: [e-mail])
From: Cindy Moore
Aquatic Toxicity Branch
Subject: Biocide Use Review
Dan River Combined Cycle
NPDES #NC0003468
Rockingham County
Dan River Combined Cycle has requested approval of the below chemicals:
Product/Chemical Approval/Comment
Hydrex 4191 TT (replacing Nalco PC) Approved—4410 grams/day
Hydrex 2365 MR(replacing Nalco 3DT187) Approved—91137 grams/day
Hydrex 2001 (replacing Nalco 3DT1999 Approved— 1534grams/day
Hydrex 1992 Approved—0.002 grams/day
Calculations predict the use of the above products, at the stated dosage rates, will not cause toxic
impacts to aquatic life.
If you have any questions or concerns,please contact Molly Nicholson at(919) 743-8424 or
[e-mail].
Sincerely,
DocuSignedd�by, Vy
1AA61A0057404B2...
Cindy Moore, Supervisor
Aquatic Toxicology Branch
Division of Water Resources,NCDEQ
cc: Sergei Chernikov,DWR(via email: [e-mail])
Jenny Gramak,WSRO(via email:[e-mail])
ATB Electronic File&Laserfiche
North Carolina Department of Environmental Quality I Division of Water Resources I Bio Lab
NoarHc�INA4401 Reedy Creek Road 1 1621 Mail Service Center I Raleigh,North Carolina 27699-1621
919.743.8400
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