NC0003468_Approval_20240313

North Carolina Department of Environmental Quality | Division of Water Resources | Bio Lab
4401 Reedy Creek Road | 1621 Mail Service Center | Raleigh, North Carolina 27699-1621
919.743.8400

March 13, 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 60448 Approved – 1345355 grams/day
Hydrex 6521 Approved – 44814 grams/day

Calculations predict the use of the above product, at the stated dosage rate, will not cause toxic
impacts to aquatic life.

If you have any questions or concerns, please contact Molly Nicholson at [phone] or
[e-mail].

Sincerely,

Cindy Moore, Supervisor
Aquatic Toxicology Branch
Division of Water Resources, NCDEQ

cc: Sergei Chernikov, DWR (via email: [e-mail])
Jenny Graznak, WSRO (via email: [e-mail])
ATB Electronic File & Laserfiche

DocuSign Envelope ID: 1472254D-8C72-4A6C-8ABD-94B40F063593