WQCS00217_NOV-2023-DV-0179_Response Rvcd_20230505

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A Carolina Water Service
of North Carolina'
Mr. Scott Vinson
Regional Supervisor
Division of Water Resources
Water Quality Regional Operations Section
3800 Barret Drive
Raleigh, NC 27609
Reference: NOV-2023-DV-0179
Carolina Trace SSO
Permit #N699643 --
Dear Mr. Vinson,
May 3, 2023 NC Depl of Erivironrnental Quality
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Carolina Water Service, Inc. of NC (CWSNC) is in receipt of the above -mentioned Notice of Violation and
appreciates the opportunity to provide the additional information below.
On March 1, 2023, at approximately 11:OOam, CWS was notified of a utility manhole overflowing behind
a residence home at 997 Windrace Trail. Operations staff were immediately dispatched to the area to
investigate. The cause of the SSO was determined to be grease that caused a blockage in the sewer main
line. A contractor was notified and the sewer main was jetted and cleaned to remove the grease and
clear the debris. It should be noted that this line was last cleaned in October 2017 as part of our ongoing
annual sewer maintenance cleaning program. We have not had any past problems with this section of
sewer main. In addition, CWSNC sends all customers education on Fats, Oil and Grease twice per year
with the last one being sent on October 18,2022.
Unfortunately, approximately 2500 gallons spilled and reached an unnamed tributary to Upper Little
River. A press release was issued to the local media as required. Fecal samples were collected upstream,
downstream and at the location of the spill. The analytical fecal results upstream were 390 MPN/100 ml,
downstream results were 2400 MPN/100 ml and at the site was 1100 MPN/100 mi. In addition,
dissolved oxygen readings were taken from the stream. Dissolved oxygen readings showed levels at
7.59 mg/I upstream, 7.26 mg/I downstream and at the spill site 7.30 mg/l. Ph samples were also
collected and results upstream were 6.4 s.u., 6.5 s.u. downstream and 6.4 s.u. at the spill site. There
were no known fish kills or other known impacts to the tributary. The overflow area was thoroughly
cleaned up. White hydrated lime was applied to the affected area to raise the pH and kill any pathogenic
organisms. There was no known impact to public health.
5821 FairviewRoad • Charlotte, North Carolina 28209 • [phone]

Carolina Water Service, Inc. of NC respectfully appreciates the opportunity to respond with additional
information for consideration of any further enforcement decisions concerning this matter. We hope
the information provided within this letter demonstrates the continued efforts to maintain compliance
at the facility and is justification for no assessment of civil penalties. If you have any questions or if I can
provide any additional information, please do not hesitate to contact me at 919-868-4701 or by email at
[e-mail] .
Sincerely,
Stephen Harrell
Area Manager
Cc; Tony Konsul - Director, State Operations
Brent Millron — Compliance Manager
5821 FairviewRoad • Charlotte, North Carolina 28209 • [phone]