NC0086665_Approval_20240508

DocuSign Envelope ID:8074F5CE-34EA-49F2-B3EA-C1996213F3F8
ROY COOPER cd
Governor
ELIZABETH S.BISERr
Secretary •E .
RICHARD E.ROGERS,JR. NORTH CAROLINA
Director Environmental Quality
May 8, 2024
To: Joyce Dishmon
Duke Energy
(via email: [e-mail])
From: Cindy Moore
Aquatic Toxicity Branch
Subject: Biocide Use Review—Corrected facility language
Rockingham County Combustion Turbine Facility
NPDES#NCO086665
Rockingham County
Rockingham County Combustion Turbine Facility has requested approval of the chemical, FQS 1.5
Microbicide.This product will be discharged from Outfall 001 and into an UT to Little Jacobs Creek.
Calculations predict the use of this product, at the stated dosage rate of 0.13 grams/day,calculated
below,will not cause toxic impacts to aquatic life in the receiving stream,UT to Little Jacobs Creek.
Therefore,the use of this product as an additive to the fuel oil storage tanks at the Rockingham County
Combustion Turbine Facility is acceptable.
17,gallons biocide = x gallons biocide
1.4 MG fuel oil 1000 gallons of oil in OWS
17,000 gallons = 0.012 gallons biocide
1,400,000 gallons per year
0.012 gal/year x 3.783 L/gallon x 1000 mil/liter x 1 g/ml x 1.06 = 48.14 g/365 days (because OWS only sees
1000 gallons/year oil)=0.13 g/day
If you have any questions or concerns,please contact Molly Nicholson at(919) 743-8424 or
[e-mail].
Sincerely,
DocuSigned by:
1AA61A0057404B2...
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
North Carolina Department of Environmental Quality I Division of Water Resources I Bio Lab
4401 Reedy Creek Road 1 1621 Mail Service Center I Raleigh,North Carolina 27699-1621
NORTHCAROLNAD 919.743.8400