NC0065480_NOV-2024-LV-0196_20240321

AOUA,,
March 21. 2024
Mr, Tom Tharrington
DWR 1 NCDEQ
Asst Regional Supervisor
Water Quality Regional Operations Section
Wilmington Regional Office
127 Cardinal Drive Extension
Wilmington, NC 28405
Re: Notice of Violation and Intent to Assess Civil Penalty
Permit No. NCO065480
Tracking Number: NOV-2024-t_V-0196
Beau Rivage Plantation WWTP
New Hanover County
Dear Mr. Tharrington:
Aqua North Carolina; Inc. (Aqua) offers the following response to the above -referenced
Notice of Violation and Intent to Assess Civil Penalty which was issued for BOD and
Enterococci individual daily maximum exceedances in January 2024:
Aqua's Response
With respect to the single BOD data point, review of Aqua's wastewater
treatment plant process control indicates an ammonia as nitrogen
concentration of less than 0.03 mgll in all treatment cells in both trains during
the month of January 2024. Effluent data on January 12: 2024, indicates a
TSS of only 3.6 mgll. As such; it is doubtful the 23 mgll BOD value is accurate
and properly represents the effluent quality for this single day. All other BOD
effluent data during the month ranged from 2 mgll to 6 mgll.
With respect to the enterococci single data point, the UV disinfection system
was fully functional and the TSS was only 3.7 mgll. It is known that grab
bacterial sampling and analysis can result in seemingly high concentrations due
to sampling method, and bacterial exponential growth rates. Therefore;
logarithmic averaging is used for calculation of the monthly mean. Please note

the geometric mean for enterococci for the month was only 131100 ml which is
far below the permit limit.
We trust that you understand the variability of test results based on sampling
method and laboratory method,
If you have any questions or comments, please contact me at [phone].
Sincerely,
Joel A. Mingus
Area Manager
cc: Brent Milliron
Shannon Becker