NC0065480_NOV-2021-LV-0182 Response_20210408

AO U A.,
April 6, 2021
Mr. Tom Tharrington, Assistant Regional Supervisor
Water Quality Regional Operations Section
Wilmington Regional Office
Division of Water Resources, NCDEQ
127 Cardinal Drive Extension
Wilmington, NC 28405
Re: Beau Rivage, New Hanover County, Permit No. NC0065480
Tracking Number: NOV-2021-LV-0182
Notice of Violation and Intent to Assess Civil Penalty
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 HOD and enterococci violations received in February 2021:
Aqua's Response,
The Beau Rivage WWTF experienced failure of the fabric in the Fluidyne filters in
February. The Fluidyne manufacturer has stated the expected life of the fabric to be
"1-1.5 years under normal use and loadings". The Beau Rivage WWTF fabric filters
fabric had been replaced mid -January 2021 with new fabric. Immediately after
getting notified of the exceedance by the lab in February the filters were pulled. The
newer filter retainers that were added late in 2019 showed several failures in the
retainers as shown below. These metal failures in the retainers cause small holes in
the fabric during the agitation and vibrating of process and backwash cycles. AQUA
has repaired these retainers and reinstalled them. AQUA also contacted Fluidyne
who is working on an alternate filter retainer to test in the Beau Rivage WWTF. This
alternate retainer design utilizes a thicker wire for the mesh, (0.192" v 0.162").
AQUA currently has 6 sets of filters in service and will test 2 sets of the new design.
This will also allow us to repair and reposition the removed "extra" 2 sets as needed.
The 2 sets of the new design are expected to arrive at the Beau Rivage WWTF in the
next 2 weeks.
All other parameters of the plant were consistent with typical treatment at the plant,
and the following samples were fully compliant.