NC0026441_NOV-2024-LV-0225_20240403

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Toboll of *i1er Cite
Public works and Utilities
March 25, 2024
Attn: Vanessa E. Manuel, Assistant Regional Supervisor
1617 Mail Service Center
Raleigh, NC 27699-1617
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Subject: NOTICE OF VIOLATION & INTENT TO ASSESS CIVIL PENALTY
Tracking Number: NOV-2024-LV-0225
NPDES Permit # NCO026441
Town of Siler City
Chatham County
Dear Vanessa E. Manuel,
This letter is in response to the NOV & Intent for Civil Penalty issues on March 13, 2024, for exceeding
the following parameters for January 2024:
Sample
Location Parameter
Limit Reported
Date Value Value
Type of
Violation
001 Effluent Nitrogen, Ammonia Total (as N) 1/27/24 6 6.3 Weekly Average Exceeded
001 Effluent Nitrogen, Ammonia Total (as N) 1/31/24 4 3.38 Monthly Average Exceeded
It is believed that these violations occurred due to nitrification inhibition in the plant starting at the end of
December and continuing into March. Once the inhibition started, we started sampling and tracking the plant's
previous data to find the reason. We had RAS brought in from another WWTP, changed our wasting patterns and
volume amount, along with working with the Hazen and Sawyer Engineer firm to help resolve the issues. We also
started to truck the WTP solids to the plant and store it in a basin while we decanted it and sent it to the press onsite
for removal to the landfill. Keeping the WTP flow out of the collection system we were able to recover the plant at
the beginning of March. We also discovered that we may were phosphorus -limited in our Influent, possibly from the
WTP in the collection system. We are working with Synagro and Hazen and Sawyer regarding the WTP residuals
and flow to the WWTP for solutions.
Sincerely, G
Brittany York,
WWTP Superintendent,
Siler City
Cc: Hank Raper —Town Manager, Chris McCorquodale— Utility Director
Brittany York Brittany York
WWTP Superintendent [e-mail]
PO Box 769.311 N Second Avenue Phone: [phone]
Siler City, NC 27344-0769 www.silercity.org