NC0021156_Annual Performance_20241028

Performance Report 12023/2024
MOUNT
HOLLY
Cann,/iud Communiir&%wwore
2023 -2024
Annual Sewer and Collections System
Performance Report
The North Carolina Clean Water Act of 1999 requires the City of Mount Holly to provide an annual
report to its customers.Also,to the North Carolina Department of Environment and Natural Resources
(NCDENR),to summarize the sewage treatment works and collection system's performance over the last
year.
You may Review Act at:
https://www.ncleg.net/Sessions/1999/Bills/House/PDF/H1160v4.pdf
Mount Holly Permits
NPDES Permit: NC0021156 RECEIVED
Land Application Permit: WQ0001863
Collections System Permit: NCCS00059 OCT 2 8 2024
Storm Water for WWTP: NCG110000(General)
NCDEQ/DWR/NPDES
Overview
Wastewater from the City of Mount Holly Residents, Businesses, and Industries flow by gravity
through approximately 131.77 miles of sewer lines,through approximately 2,846 manholes,to one of 18
lift stations.The Wastewater then flows to the City of Mount Holly's Wastewater Treatment Facility
where it is then treated.When the wastewater enters the facility, it is screened to remove any large
debris.After screening the wastewater flows by gravity through 2 (two million gallon)aeration basins
which is where the biological portion of the treatment occurs. In the biological process tiny microscopic
bacteria and organisms treat the wastewater and oxygen is added.After aeration the wastewater flows
to two clarifiers where the wastewater is slowed down and the biological organisms are separated from
the water by gravity.After clarification the biological organisms are sent back to the beginning of the
process and met with incoming flow, Once the Organisms have been through the process enough,they
get pumped into two 750,000 gallon digesters where it is aerobically digested prior to Land Application
on farm land for the re-use of the nutrients.The treated water leaves the clarifiers and flows into two
chlorine contact basins where the water is met with chlorine for disinfection purposes. Once any
remaining bacteria has been killed by the chlorine the treated water flows through sulfur dioxide to
remove the residual chlorine prior to discharge into the Catawba River. Below is a simple diagram of the
treatment process at the City of Mount Holly Wastewater Treatment Facility.
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Performance Report 12023/2024
Sampling
Each year the City of Mount Holly performs over 37,000 measurements and chemical analysis
annually to comply with permit requirements,treat the wastewater and safely return it to the
environment.The City's staff of trained and certified operators are committed to the goal of providing
the wastewater customers with the most efficient, cost effective wastewater treatment. Below is a table
of the current discharge limitations and the average daily discharge from the Mount Holly Wastewater
Treatment Facility.
Monthly Weekly Daily Daily Annua Average Maximu Minimu
Average Average Maximu Minimu I Discharge m m
limit limit m m Limit 7/1/22- Daily Daily
limit limit 6/30/23 Discharge Discharg
_ e
Flow in 4.0(MGD) 1.961
Million MGD
Gallons per
Day(MGD) _
Biochemica 30.0 mg/I 45.0 mg/I 3.48 mg/I
I Oxygen
Demand
(BOD)
Total 30.0 mg/I 45.0 mg/I 4.45 mg/I
Suspended
Solids(TSS)
Fecal 200/100m 400/100m 4.72/100m
(Geometric I I I
Mean)
Total fi 50 ug/I 28 ug/I
Residual
Chlorine
(TRC)
Dissolved 5.0 mg/I 5.8 mg/I
Oxygen
(DO)
PH 9.0 su 6.0 su 7.4 su 6.0 su
Annual 31,405 114550 lbs
2020 Total lbs
Phosphorus
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Performance Report I 2023/2024
Performance
The City of Mount Holly is committed to constantly improve our Wastewater Treatment Facility and
Collections System to protect the customers and the environment from the potential harm of
inadequately treated wastewater.
Wastewater Treatment Plant
The City of Mount Holly Wastewater Treatment Plant had zero permit violations for the
2023/2024 fiscal year.
Wastewater Collections System
The City of Mount Holly Wastewater Collections System has had a total of 95 residential sewer
stops and has ran a total of 74,365 feet(14.08 miles)of sewer mains to try and prevent SSO's.
The City of Mount Holly Wastewater Collections System had 1 permit violation for the
2023/2024 fiscal year.The 15,violation occurred on 6-17-24 on the right of way behind 402
Louise Ave and lasted for approximately 1 hour and 15 minutes and resulted in 1000 gallons of
sewer reaching the ground and approximately 250 gallons of sewer reached an unnamed creek
vein.This SSO was determined to be caused by a sewer lateral protruding the sewer main.
Notice of Deficiency was given for this SSO.
Public Notification / How You Can Help Protect the Environment
In the event of an overflow the City has the responsibility to repair the problem causing the overflow
and mitigate any damage.The City also has to report the spill to the State. If the spill exceeds 15,000
gallons, a public notice is issued at the time of the spill.The State can fine the City for large overflows.
Most overflows are caused by grease or obstructions in the system. You can help stop overflows by
keeping fats, oils and grease out of your drain.You can also call City Hall or the 24hr Utility Customer
Service at(980)522-0202 if you see a manhole overflowing, missing manhole cover or broken pipes.
If you have any questions concerning our Wastewater system or this report please contact the
Wastewater Treatment Facility at [phone].
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Performance Report 12023/2024
Name of Regulated Entity and Responsible Contact
Mount Holly Wastewater Treatment Plant
City Manager: Jonathan Blanton
P.O. Box 406
Mount Holly, NC 28120
704-827-3931
(Wastewater Treatment)
Operator in Responsible Charge: Keith E. Lynch
P.O. Box 406
Mount Holly, NC 28120
704-827-4261
(Collections System)
Operator in Responsible Charge: Ronnie Hale
P.O. Box 406
Mount Holly, NC 28120
704-913-5090
Certification
I certify,to the best of my knowledge,this report is accurate and complete meeting the requirements of
the North Carolina House bill 1160, 1999 Clean Water Act, and the guidance provided by(DWQ) Division
of Water Qua 'ty Compliance and Enforcement Unit's letter of October 10, 1999.
. � /19-2;43/4
Jona n B :nton, City Manager Date
This report is posted on www.mtholly.us and is available at City Hall upon request
Submit 3 copies to:
System Performance Annual Report
North Carolina Division of Environmental Quality
1617 Mail Service Center
Raleigh, NC 2 7699-1 61 7
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