NC0055786_Correspondence_20230807

ROY COOPER "' V
Governor kELIZABETH S. BISERSecretaryQ
RICHARD E. ROGERS, JR. NORTH CAROLINA
Director Environmental Quality
August 7, 2023
Steve Sutton, ORC
City of Lexington WWTP
28 West Center Street
Lexington, NC 27292
Subject: Technical Assistance Visit
City of Lexington WWTP
NPDES Permit NCOOSS786
Davidson County
Dear Mr. Sutton,
On Friday, August 4, 2023, Jesse Barnes, and I met with you and other WWTP staff for a
Technical Assistance visit at the City of Lexington Wastewater Treatment Plant located in
Davidson County. The visit was at your request concerning some higher -than -normal
effluent ammonia and BOD results causing the WWTP to violate the NPDES permit limits.
Our observations and highlights of our conversation are listed below for your review.
• Start running a MLSS sample and a settleability test on each train separately.
• Shut one influent sluice gate to the A train. By doing so you will be reducing the
organic and the hydraulic loading to train A by one third, thus reducing the oxygen
demand.
• Have a flange installed on the air header piping for the A train and install temporary
fine air diffusers until permanent repairs can be made.
• Divert the flow from train A to train B, and use train A as a flow equalization basin
until permanent repairs can be made. A submersible pump can be lowered during
and after heavy rain events to keep the A train lowered for the next rain event.
North Carolina Department of Environmental Quality I Division of Water Resources
4NORT�HCv Winston-Salem Regional Office 1 450 W. Hanes Mill Rd, Suite 300 1 Winston-Salem, North Carolina 27105
NORrricaRouNa � 336.776.9800
Department of Emlmnmenfal Deali�

Our office appreciates the effort that you and the WWTP staff puts into staying in
compliance with your NPDES permit by reaching out to the Winston-Salem Regional Office
for technical assistance.
In closing I would like to thank you for the opportunity to visit the City of Lexington
Wastewater Treatment Plant and try to help you with your plant problems. It was a
pleasure getting to work with you and your staff and tour the plant. If I can be of any more
help, please do not hesitate to contact me at.Gary.HudsonOncdenr.gov or (336) 776 -
9694.
Sincerely,
Gary Hudson
Water Quality Regional Operations
Division of Water Resources
North Carolina Department of Environmental Quality I Division of Water Resources
D E Q�� Winston-Salem Regional Office 1 450 W. Hanes Mill Rd, Suite 300 1 Raleigh, North Carolina 27105
NORTH CARouNA 336.776.9800
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