NC0024252_Response on letterhead July_20230926

City of Conover
Andrew Pitner P.G., Regional Supervisor
Subject: Response to NOV-2023-LV-0621
Permit number NCO024252
Northeast WWTP
Catawba County
We have recently been assessed an NOV for the month of July regarding our permit violation for Ammonia as
N limit. We have been struggling with this limit due to the lack of DO in our basins. We have been hovering in the 0.5-
1.5 mg/L of DO since summer began. We feel this is due to the 31-year-old infrastructure in the plant. Including
blowers, piping, valving, diffusers, and electronics. We have recently changed some programming and valving in our
blower system to run 2 blowers into 1 basin, at a time, to help rectify this situation temporarily. This is only a
temporary fix, and requires an operator to manually "trick" our system during phase change.
As stated in our last NOV response letter, we have engineered and bid an aeration project upgrade. This will
upgrade our blower, piping, diffusers, and controls to rectify this re -occurring issue. Bids came in above estimated
budget and we have had to go out for financing. Financing has been secured and we are awaiting Brushy Mountain
Builders bond information before we issue a letter to proceed. Once the letter to proceed is issued; Brushy Mountain
Builders estimates a full project timeline of 18-24 months, with a majority of that time being due to equipment
procurement.
We have also implemented internal ammonia testing for our purposes so we can adjust our procedures and
operations accordingly. We are testing influent ammonia, as well as effluent, and individual basin ammonia. These
numbers help us determine the effect of 2 blowers vs 1 instantly versus having to wait for our contracted lab to report
their results back to us. Of course, we are not an approved laboratory for these parameters, so we strictly use this test
for operational purposes and not for state required reporting.
With this timeline of 18-24 months, we expect to be in violation of our ammonia limit from time to time. Do
we need to notify the state, within 24 hours, every time we are in violation? And if so, would you like us to shoot Wes
Bell an email when this happens?
Regards,
Andrew Evans, WWTP ORC/Pretreatment Coordinator
[Post Office Box 549 1 Conover, North Carolina 128613 1 voice/tdd [phone] 1 fax [phone]]