NC0020389_NOV-2021-LV-0231/0232 Response_20210415

MAYOR
JERRY M MEDLIN
MAYOR PRO-TEM
CASANDRA P. STACK
COMMISSIONER
MAXINE HOLLEY
JAMES D JOHNSON
DEAN MCLAMB
WILLIAM NEIGHBORS
DR R MAX RAYNOR
April 15, 2021
TOWN OF BENSON
PO BOX69
303 EAST CHURCH STREET
BENSON, NC 27504
[phone]
FAX [phone]
www townofbenson com
Scott Vinson, Regional Supervisor
Water Quality Regional Operations Section
Raleigh Regional Office
Division of Water Resources, NCDEQ
3800 Barrett Drive
Raleigh, NC 27609
Re: Response to Notice of Violation
NOV-2021-LV-0231
NOV-2021-LV-0232
Dear Mr. Vinson,
TOWN MANAGER
FREDERICK NELSON
ASSISTANT TOWN MANAGER
KIMBERLY PICKETT
TOWN CLERK
ANGELA THORNTON
TOWN ATTORNEY
R ISAAC PARKER
NC Dept of Environmental Quality
API? 2 3 2021
Raleigh Regional Office
Please accept this written response to the above -referenced Notice(s) of Violation issued to the Town of
Benson for the permitted effluent flow exceedance for the months of January and February, 2021. The
Town acknowledges receipt of these notices on April 14, 2021, and presents the following information
regarding the noted violations:
a. Cause of Increased Flow
The Town saw a marked increase in total influent flow to the WWTP in 2020. The approximately
4% annual increase that was being tracked in previous years suddenly jumped by over 17% in 2020.
We believe several factors contributed to this increase, to include: the COVID-19 pandemic keeping
more residents at home utilizing water and sewer; our SIU increasing their production to contribute
materials used as personal protective equipment and cleaning wipes; and a particularly wet year with
approximately ten extra inches of rainfall vs. recent annual rainfall totals.
b. Sur ortinData
# Rain Events
Rainfall Total
(inches)
AVG Effluent
Flow (MGD)
SIU flow
(MGD)
2019
N/A
52.98
1.240
0.226
2020
N/A
62.86
1.570
0.302
Dec 2020
9
4.21
1.579
0.337
Jan 2021
12
5.7
2.193
0.310
Feb 2021
14
11.59
2.472
0.333
Mar 2021
6
3.13
1.736
0.362 *
* estimated until reported by SIU

c. Operations
The new year started off with rain after a very wet 2020, and that trend continued through
February. We saw peak flows above 4 MGD coming into the plant at times. Excess flow was diverted
to the EQ ponds during high flow events, but the pond levels were already somewhat elevated from the
previous year's rain. These ponds had to be regularly pumped down (back into the plant) in order to
maintain the 2 foot freeboard requirement and avoid any spillage. This pumping was done any chance
the influent flow dropped enough to allow for it. The frequent rain events kept the water table
elevated, which contributed to significant inflow and infiltration (MI) to the plant. There was not
much relief from this condition over this two month span. Plant staff worked carefully to ensure that
we were able to treat all of the flow entering the plant, but the influent totals exceeded our capacity to
store any excess. We discharged fully treated wastewater with total flow as the only permitted
parameter violation. This non-compliance was noted on the eDMR's submitted for the months of
January and February, 2021.
d. Mitigation Efforts
The Town has been actively locating and repairing I&I locations throughout our collection system and
has budgeted time and funding to continue to do so. We also continue to manage our EQ ponds to
allow for storage during heavy rainfall events. Additionally, the timeframe on capital investment in
upgrading the plant has been shortened as a result of the signification increase in influent flow rate
observed in 2020. The Town has engaged two engineering firms to make recommendations and seek
funding for a plant expansion/upgrade.
We appreciate your consideration of this response. The Town remains committed to the quality and
safety of our natural resources. If you should have any questions or require additional information,
please do not hesitate to contact myself; Tim Robbins, Public Utilities director; or Fred Nelson, Town
Manager.
Best Regards,
i
Brian Leavitt
Superintendent i ORC
Town of Benson WWTP
919-902-9599
bleavittru,townofbenson.com
cc: Fred Nelson, Town Manager
Tim Robbins, Public Utilities Director