NC0024201_Response to NOV-2021-LV-0270_20210505 (2)

Roanoke Rapids Sanitary District
April 29, 2021
Ms. Vanessa Manuel
Water Quality Regional Operations Section
Raleigh Regional Office
Division of Water Resources, NCDEQ
Re: NOV-2021-LV-0270
Permit NC0024201
Dear Ms. Manuel,
P.O. Box 308
1000 Jackson Street
Roanoke Rapids, NC 27870
[phone]
Fax: [phone]
www.rrsd.org
I am writing you in response to the above referenced NOV for our Total Suspended
Solids limits violations for the month of February 2021. As I am sure you are aware,
Roanoke Rapids, along with most of North Carolina, was inundated with heavy,
unseasonable rains. Rainfalls of 7.05" were recorded at the plant for the period from
February 1, 2021 through February 20, 2021. These rains led to unusual high flows for
extended duration. Average flows for the week in question were 10.6 MGD. In
comparison, during the same period from the year before, rainfall total was 3.95" and
flows averaged 4.6MGD. Rainfall in the region was high enough that river flows in the
Roanoke River were elevated to 35,000 CFS multiple times, leading the plant to pump
it's discharge to the river through the Flood Pump Station for a total of 72 days between
11/12/2020 and 3/7/2021. Coupled with the fact that the rains and wet weather made land
application next to impossible, thus limiting our ability to waste solids from the activated
sludge system, the high flows exhausted our equalization capacity and caused solids to
wash out of the plant. All efforts were made to keep this from happening, but the nearly
constant rains prevailed. We had fed polymer in our clarifiers, diverted solids to empty
basins, and bypassed flow to influent EQ tanks with the result being a washout.
The district has made great effort over the past few years to minimize I&I in much of its
collection system. That effort continues as we are still rehabbing our system and plan to
continue to find and repair as many sources of I&I as we can.
Thank you for your consideration,
Steven L. Ellis, WWTP ORC
Roanoke Rapids Sanitary District
CC: Gregory Browning, Chairman
Dan Brown, CEO
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