WQ0034367_RESP to NOV-2020-LV-0059, 0060_20200213

February 13, 2020
Morella Sanchez -King, Regional Supervisor
NCDEQ — Division of Water Resources
Wilmington Regional Office
127 Cardinal Drive Extension
Wilmington, North Carolina 28405
RE: Notice of Violation & Intent to Assess Civil Penalty
Permit No. WQ0034367
Northwest Regional Water Reclamation Facility
Onslow Water & Sewer Authority, Onslow County
Ms. Sanchez -King:
4
ONWASA
onwasa.com
228 Georgetown Rd
Jacksonville, NC 28540
This letter is sent in response to Notice of Violations (Tracking Numbers NOV-
2020-LV-0059 and NOV-2020-LV-0060) issued to the above -referenced facility due to
exceedance of permit limits during October and November 2019.
While ONWASA does not dispute the basis for these NOV's (as the test results
were self -reported), facility staff have worked diligently to determine the cause of the
elevated Total Suspended Solids (TSS) readings and have taken both immediate and
long-term actions to address this issue. These actions have included:
• Repeated cleaning and replacement of individual filter panels within a
temporary disc filter assembly installed after Hurricane Florence.
• Cleaning and re -calibration of the turbidimeter monitoring this flow.
• Cleaning the post -equalization basin, effluent contact chamber and effluent
pumping station to remove possible solids sources.
• Contracting with the supplier of the temporary disc filter assembly to perform
an extensive service on this unit, including replacement of all filter panels and
several gaskets/seals, as well as rebuilding the backwash pump.
• Initiation of several minor treatment process changes (such as increasing SBR
decant depth) and conducting additional TSS sampling to provide more data
on how the plant is performing and the need to make process adjustments
before problems occur.
In addition to these actions, ONWASA is also working with an outside Professional
Engineering firm (WK. Dickson and Company) under multiple contracts to assist with plant
operation and design of repairs to various systems (including the permanent disc filtration
system) that were damaged by flooding during Hurricane Florence. As an update to the

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February 12, 2020
recovery effort, a construction contract has been awarded for the first repair project
(restoration of the plant's disc filtration and UV disinfection systems), and a second
construction contract to restore electrical and control systems will be bid and awarded
later in 2020.
If you have any questions of need additional information please feel free to contact
me directly at 910-937-7521 or dmohr(@-onwasa.com.
Sincerely,
.4""t4l Pe -
David M. Mohr, P.E.
Chief Operations Officer
Onslow Water & Sewer Authority
C: Mark Young, NWRWRF ORC
Jim McDonnel, Treatment Facilities Administrator
Jim Holland, WK Dickson