NC0024406_Installation of Submerged Flight Conveyer_20180212

DUKE
ENERGY
February 12, 2018
Mr. Jeff Poupart, Section Chief
NC DWR Permitting Section
1617 Mail Service Center
Raleigh, NC 27699-1617
Subject: Installation of Submerged Flight Conveyer
Belews Creek Steam Station
Permit #NC0024406
Stokes County
Dear Mr. Poupart:
Duke Energy
EHS CCP Environmental Programs
411 Fayetteville Street, 15`h Floor
Raleigh, NC 27601-1849
RECEIVED/DENR/DWR
FEB 2 © 2018
Water Resources
Permitting Section
In accordance with requirements found in state and federal laws, Duke Energy is re-routing bottom ash sluice
wastewaters away from ash basins. To continue to handle these wastestreams, Belews Creek Steam Station (BCSS)
is installing a Submerged Flight Conveyer (SFC) for the dry handling of bottom ash. This change was
communicated to your office as part of the pending NPDES permit application for BCSS dated August 29, 2016.
The installation of the new SFC will be completed in March 2018. This letter is intended to provide notification of
the process startup and redirection of the wastewater prior to receipt of final NPDES permit. This is consistent with
guidance received by your staff on January 3, 2018 from Sergei Chernikov and Sherri Knight.
Bottom ash from the boilers will be collected in water filled troughs for transfer to the SFC to direct the bottom ash
wastewater away from the ash basin. Overflow water from the SFC trough is captured, cooled, and recirculated.
The SFC is designed with a blowdown system for the overflow water to be discharged to the Flu -Gas
Desulfurization wastewater treatment system (FGD WWTS) as needed. Federal Effluent Limitation Guidelines
(ELGs) contain allowance to route bottom ash transport water overflows from the SFC to the FGD WWTS.
Additionally, small, incidental flows from the SFC may be sent to the ash basin or Lined Retention basin (once in
service). The FGD WWTS discharges to NPDES internal outfall 002 which discharges to the ash basin to NPDES
outfall 003.
In conclusion, the startup of the SFC will decrease the pollutant load and flow volumes of the ash basin discharge.
The startup of the SFC is a necessary step in the process or re -directing process wastewater flows away from the ash
basin as we proceed with activities to comply with various statutory requirements. It is our understanding from
previous discussions with your staff that no additional approvals are necessary beyond this notification.
If there are any questions about this matter, please Joyce Dishmon at [phone].
Sincerely,
E. Shannon Langley
Lead Environmental Specialist
cc: Sherri Knight — WSRO, 450 West Hanes Mill Road, Suite 300, Winston-Salem, NC 27105
Joyce Dishmon/Filenet - via email
Richard Baker - via email
Julie Grzyb — NC DWR 1617 Mail Service Center Raleigh, NC 27699-1617