NC0040011_DMR Review Record_20230517

DMR REVIEW RECORD
Winston-Salem Regional Office
Facility Name: Yanceyville WWTP Permit Number: NCO040011
Report Period: March 2023 Prior Assessments: 0 Enforcement Factor: 1.00
Waterbody
Outfall # Outfall Description
Waterbody Name
Classification
001 Effluent to Country Line Creek
Country Line Creek
C
Monthly Average Limit Violations
Sample Location: Outfall 001- Effluent
Violation
Unit of
Limit
Calculated
% Over
Date Parameter
Frequency
Measure
Value
Value
Limit
Action
3/31/2023 BOD, 5-Day (20 Deg. C) -
Weekly
mg/I
30
38.10
27.0
Concentration
3/31/2023 Nitrogen, Ammonia Total (as N) -
Weekly
mg/I
13
16.00
22.9
Concentration
Weekly Average Limit Violations
Sample Location: Outfall 001- Effluent
Violation
Unit of
Limit
Calculated
% Over
Date Parameter
Frequency
Measure
Value
Value
Limit
Action
3/18/2023 BOD, 5-Day (20 Deg. C) -
Weekly
mg/I
45
46.90
4.2
Concentration
Other Violations/Staff Remarks:
County: Caswell
MAF: 0.200871 MGD
Reported as: "Non -Compliant"
eDMR Comments: "For Validated Warnings on Influent & Effluent Sample Frequencies, all parameters were sampled for Week #1
on Tuesday February 28, 2022 during that calendar week.
The Weekly BOD limit was exceeded for Week 3 and the Monthly BOD limit was exceeded.
The monthly average % Removal exceeded 15% for Effluent BOD at 75.5 %, less than the required 85% removal.
The Monthly Average Ammonia limit was exceeded.
Elevated BOD and Ammonia levels continued to be related to the failure of a decanter actuator, storm event and power failure
occurring on Saturday 02/11/23, combined with a low MLSS inventory. The actuator was finally placed back into service on
Thursday evening 03/09/23. Seed mixed liquor was brought in from nearby wastewater facilities over the course of several days
between 03/09/23 and 03/21/23. Faulty level indications prevented the SBR Basins from returning to normal phase operation.
Plant operations continued with a single basin for the remainder of the month. A faulty float was replaced on Monday 03/27/23.
The system still would not return to normal phase operation with normal influent flows repeatedly returning to Storm Mode every
other cycle. This is essentially a short circuit of the treatment process. The control unit for plant operation is an older, outdated
system with no SCADA. The necessary software to monitor the PLC circuits to troubleshoot the controls was obtained on
Wednesday 03/29/23. All floats were found to be communicating normally. Solids were managed by manual transfer, aeration
& mixing to try to maximize treatment while continuing to troubleshoot the phase controls and returning the second basin to
service."

JSB Remarks: Equipment malfunction, heavy rain, power failure, and low MLSS appear to have caused exceedances.
JSB Recommendation: NOV
Supervisor Remarks:
Lon NOV NOV-2023-LV-0347
Completed by: Jesse Barnes Date: 5/17/2023
Assistant Regional
Supervisor Sign -off: Date:
Regional
Supervisor Sign -off: LTS Date: 5/19/2023

Prior 12-Month Enforcement Histor
Permit Number: NC0040011
Report Period: March 2023
Limit Violation
Sample Location:
Outfall 001 - Effluent
Violation
Report
Violation
Date
Period
Parameter
Type
NOD NOV CPA
12/31/2022
12-2022
Solids, Total Suspended -
Monthly Average
NOV-2023-LV-0140
Concentration
Exceeded
12/31/2022
12-2022
Solids, Total Suspended -
Weekly Average
NOV-2023-LV-0140
Concentration
Exceeded
5/14/2022
5-2022
Nitrogen, Ammonia Total (as
Weekly Average
NOV-2022-LV-0638
N) - Concentration
Exceeded
8/20/2022
8-2022
BOD, 5-Day (20 Deg. C) -
Weekly Average
NOV-2022-LV-0748
Concentration
Exceeded
8/31/2022
8-2022
Nitrogen, Ammonia Total (as
Monthly Average
NOV-2022-LV-0748
N) - Concentration
Exceeded
9/3/2022
9-2022
Nitrogen, Ammonia Total (as
Weekly Average
NOD-2022-LV-0137
N) - Concentration
Exceeded