NC0043176_Correspondence_20201019

north carolina
LLuDUNN
city of dunn
POST OFFICE BOX 1065 • DUNN, NORTH CAROLINA 28335
[phone] • FAX [phone]
www.dunn-nc.org
October 19, 2020
Re: City of Dunn, NC
Black River W WTP
NPDES Permit No. NC0043176
Aeration System Replacement
DWI Project E-SRP-W-17-0106
DMP 170207 (AL)
Mr. Trent Allen
NCDEQ Fayetteville Regional Office
225 Green Street
Suite 714
Fayetteville, NC 28301
Dear Trent:
Mayor
William P. Elmore Jr.
Mayor Pro Tern
Chuck Turnage
Council Members
J. Wesley Sills
April L. Gaulden
Frank McLean
Billy Tart
Dr. David L. Bradham
City Manager
Steven Neuschafer
As an update to our July 8, 2020 letter, the City of Dunn continues to make progress towards completing
a much needed Aeration System Replacement Project. On October 8th, aeration basins 3 & 4 were
placed back into service and it took approximately one week to ensure the mixed liquor suspended
solids were sufficient before taking aeration basins 1 & 2 out of service. The contractor has reached the
point where we must remove aeration basins 1 & 2 from operation so that they can clean, demo existing
equipment, and install new aeration components.
Again, this will reduce the available basin capacity by 50%, and also reduce the capacity to pass wet
weather flows downstream to the final clarifiers. We plan to use the equalization basin to manage flows
during rain events and maximize the level of treatment to the extent possible.
The following is an outline of the contractor's proposed schedule:
Target
Date Activity
October 15`h Dewater Basins 1 & 2, begin cleanout
Nov V Begin installation of new diffusers
Nov 29' Test system, return Basins 1 & 2 to service
Dec 61h Complete punch list

We will update the Regional Office as these tasks progress forward. If you have any questions, or need
additional information, please let us know.
Sincerely,,
/ '�1"
Heather Adams
Public Utilities Director
DUNN
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