WQCSD0267_NOV-2020-DV-0038 Response_20200219

AQUA.
February I9, 2020
Mr. Scott Vinson
Regional Supervisor
Public Wastewater Supply Section
Raleigh Regional Office, NCDEQ
1628 Mail Service Center
Raleigh, NC 27699-1628
Re: Notice of Violation
Chapel Ridge WWTP
Permit No. WQCSD0267
NOV-2020-DV-0038
Dear Mr. Vinson:
NC Dept of Environmental Quality
FEB 2 � 12M
Raleigh Regional Office
Aqua North Carolina, Inc. (Aqua) offers the following response to the above -referenced Notice of Violation,
which was issued for a Sanitary Sewer Overflow.
Aqua's Response:
Incident number 201901928 that occurred on December 11, 2019 was a result of an electrical failure
within the control panel. A control fuse upstream of the alarm system had failed and prevented the signal
from the high water float from reaching the telemetry unit.
The fuse issue was corrected on the same day, December 11, 2019. This alarm and telemetry system
were installed and operated in accordance with state regulations; however, to reduce the risk of
recurrence and to increase the resiliency of the system, the high water alarm was rewired to directly
notify the telemetry unit without any intermediate devices.
Normal operator work includes weekly testing of the high water alarm and telemetry, and records
indicate the operator had tested the unit during the preceding week. As a new level of testing all Aqua
NC wastewater pump stations were tested by first disconnecting all sources of power (line power and
generator power) and then lifting the high water alarm. In this condition, telemetry systems were tested
to ensure it indicated both the loss of power condition and the high water alarm condition. We found
more than 60 pump stations where the simultaneous loss and power and high water alarm would not
result in telemetry notification. Aqua is currently upgrading all of its pump stations to add this
resiliency. This is above and beyond the normal testing of high water alarm telemetry systems, and
NCDWR may wish to consider updating operator training to include this test condition or even an
administrative code amendment.
202 MacKenan Court, Cary, NC 27511 - 919.467.8712 - AquaAmerica.com

Page Two
Mr. Scott Vinson
February 19, 2020
With respect to the Sanitary Sewer Overflow, remediation was conducted onsite and residual standing
wastewater was removed and pumped back into the Iift station for treatment. The rip rap near the creek
was cleaned and the surrounding surfaces were raked and the area was limed.
If you have any questions or comments, please do not hesitate to contact me at [phone].
Sincerely,
Robert Krueger
Area Manager
cc: Joseph Pearce
Amanda Owens
Shannon Becker
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