NC0024112_Annual Performance_20230209

Wastewater Treatment Plant
PERFORMANCE ANNUAL REPORT
2022
I. GENERAL INFORMATION
Facility/System Name: City of Thomasville Hamby Creek Wastewater Treatment Plant
Responsibility Entity: City of Thomasville
P.O. Box 368
Thomasville, NC, 27361
Person in Charge/Contact: Morgan Huffman, Utilities Director
P.O. Box 368
Thomasville, NC, 27361
[phone]
Applicable NPDES Permits: NC00024112 (Wastewater Treatment Plant),
WQCS00057 (Collection System),
NCG110000 COC#NCG110094 (Stormwater-Industrial Site),
WQ0006050 Non -Discharge (Sludge Disposal),
NCO098200 (Alum Lagoon)
CERTIFIED MAIL RETURN RECEIPT NUMBER: 70210350 0000 6439 4750
Description of Collection System:
The Thomasville sanitary sewer collection system is comprised of a system of 227.232 miles, or 1,199,784 linear
feet of pipe, and 26 sewage lift stations spread throughout the area.
Description of Treatment Process:
Hamby Creek WWTP is a 6.OMGD capacity grade 4 wastewater treatment facility using the 5-Stage Bardenpho
process with post aeration to achieve biological nutrient reduction of both phosphorus and nitrogen. Headworks
equipment consists of an automated solids removal bar screen and a grit removal system. Secondary treatment
consists of two parallel trains of treatment, each consisting of an anaerobic zone, an anoxic zone, an oxidation ditch,
and second anoxic zone, and reaeration. Removal of activated sludge is accomplished in two circular secondary
clarifiers equipped for removal of solids for return to the process or wasting to a digestion system. Effluent from the
two circular -clarifiers is filtered through 10 micron disk filters and then receives disinfection via a UV system prior
to post aeration and discharge into Hamby Creek. Waste activated sludge is belt pressed and landfilled or
anaerobically digested to standards for class B sludge as defined by EPA in CFR Part 503 then applied to farm land
as a beneficial reuse. No land application of biosolids from Thomasville occurred in 2022.
II. PERFORMANCE
In 2022 Hamby Creek WWTP treated 886.5 Million Gallons of wastewater at an average daily flow of 2.43MGD.
The treatment plant was in compliance for all effluent parameters for 11 months of the year. The exception to this
was in January when a high flow event caused the BOD5, weekly average limit to be exceeded once.
In the sanitary sewer collection system six (6) sanitary sewer overflows were experienced as summarized in the table
below. Two (2) of the sanitary sewer overflows were more than one -thousand gallons in volume. Construction
projects, described below the table, have been completed and more are planned for the future to address areas where
repeated sanitary sewer overflows have been experienced. The Water Sewer Utility Project List can be seen on the
City website.

Four things that users of the system can do to help prevent overflows are:
1) NEVER place GREASE or OIL into the sanitary sewers sy tem. It may be liquid in your pan, but it
becomes as hard as concrete in the sewer system. Instead, either place grease and oil wastes in empty
containers and place these into the garbage or, preferably, BRING YOUR USED COOKING OIL TO
THE PUBLIC WORKS FACILITY AT 525 TURNER STREET TO HAVE IT RECYCLED. The
city has contracted with a private vendor to recycle citizen's used cooking oil free of charge. You can help
the environment in multiple ways by recycling your used cooking oil and helping to prevent sanitary sewer
overflows at the same time. None of the sanitary sewer overflows in 2022 were attributable to grease
blocking the lines — Good work Thomasville!
2) NEVER place down the drain anything that will not biodegrade in a few days. Put another way, if you
wouldn't leave it in your front yard and expect it to biodegrade in a few days, then don't put it down
the drain. Three (3) of the sanitary sewer overflows in 2022 were attributable at least in part to debris
blocking the lines.
3) Make sure no trees or shrubs grow on or near any sewer lines that may pass through your yard. Roots will
seek out the water being carried in the pipes and penetrate the pipe at the joints, creating a blockage. An
aggressive program of removal of vegetation from sanitary sewer easements has helped to bring the number
of spills caused by roots down. This program is showing results in the fact that none of the spills in 2022
were attributable to roots blocking the lines.
4) :flake sure no roof or vard drains are hooked into the sanitary sewer system and that cleanout ca s are
securely hi place. The sanitary sewer system can become overloaded during rainfall events if roof or yard
drains are mistakenly connected to the sanitary sewer system or if cleanout connections in your yard are
missing their caps. Roof and yard drains should be run off into open areas or a rain garden for absorption
into the ground and by plants. None of the sanitary sewer overflows in 2022 were caused by the inflow
and infiltration of rainwater. This was largely the result of 2022 being a fairly dry year rather than
enough sources of inflow and infiltration of rainwater being addressed.
SANITARY SEWER OVERFLOWS
During 2022 the City of Thomasville experienced six (6) sanitary sewer overflows, five (5) of these reached surface
waters. There were no known environmental impacts from these sanitary sewer overflows. These spills are
summarized in the table below and represent only about 0.0021% of the water that was collected in the sanitary
sewer collection system. Another way of stating this is that 99.9979% of the water collected made it to the plant and
thru the treatment process.
Month
Date
Location
Volume
Cause
Reached
(Gallons)
Surface
Waters of
the State?
February
2/08/22
Salem Street
2
Debris in Line
N
July
7/26/22
West Cooksey
Pump Station Equipment
p
Y
Drive
200
Failure
Old Emanuel
9/28/22
Church Road
4400
Other
Y
September
Old Emanuel
9/28/22
Church Road
13500
Pipe Failure
y
October
10/20/22
Church Street
2
Debris in Line
y
November
11/11/22
West Cooksey
200
Debris in Line
Y
Drive
The City of Thomasville continues to address the issue of sanitary sewer overflows through the planning and
implementing sanitary sewer infrastructure rehabilitation projects and by increasing the amount of maintenance done
to the existing system. Phase 3, the final phase, of the North Hamby Creek Outfall line upgrade project completed
construction in 2021. Completion of phases 1 and 2 of this project had already greatly reduced both the number and
volume of large spills experienced in this portion of the collection system. Phase 2 of upgrades to the Hanks Branch
Basin Collection System was also completed in 2022. A flow study of the sanitary sewer collection and treatment
systems has been completed and engineering design of upgrades to the Rains Road Pump Station and Force Main
are nearing completion. Continued monitoring and evaluation of Inflow/Infiltration issues in both the Hasty Creek
and Hunts Fork Creek outfall areas should lead to future infrastructure projects. Numerous smaller pipe replacement
and rehabilitation projects are performed every year by contractors hired by the city.

1--'e
In addition to these projects to address infrastructure issues the City has begun a more aggressive program of Right -
of -Way maintenance over the last decade. This program consists largely of the cutting and removal of vegetation
that has been allowed to grow within the sanitary sewer rights -of -way or easements. Several local tree services have
been employed to help in this effort along with clearing performed by City of Thomasville personnel. In
conjunction with this program a private contractor has been hired to chemically treat select sections of the collection
system that have experienced problems associated with root intrusion into the lines. The chemicals they use kill
back the root growth and prevent re -intrusion for at least three years.
III. NOTIFICATION
Public notification of the availability of this report was made using the city government
information channel (cable channel 13), the Facebook social network, and the City web site. This report
was prepared and issued in compliance with the North Carolina Clean Water Act of 1999. Copies of this report are
available at the City of Thomasville Water Department located in City Hall, 10 Salem St., Thomasville, N.C, and on
the City web site http://www.thomasville-nc.pov/.
IV. CERTIFICATION
I certify under penalty of law that this report is complete and accurate to the best of my
knowledge. I further certify that this has been made available to the users or customers of
the named system and that those users have been notified of its availability.
Michael M. Brandt Date
Responsible Person
Title: City Manager
Entity: City of Thomasville
Explanation of Acronyms Used:
BOD5: Biochemical Oxygen Demand 5 Day
DO: Dissolved Oxygen
I & I: Inflow and Infiltration
NPDES: National Pollutant Discharge Elimination System
MGD: Million Gallons per Day
TSS: Total Suspended Solids
WWTP: Wastewater Treatment Plant