NC0031879_2021 Wastewater System Performance Report_20220217

WASTEWATER SYSTEM PERFORMANCE REPORT
January 1, 2021— December 31, 2021
City of Marion Public Works Department
PO Drawer 700
Marion, NC 28752
[phone]

Description of Wastewater Treatment System
The City of Marion owns and operates a wastewater treatment system consisting of a wastewater
collection system and one wastewater treatment plant. The wastewater collection system
consists of the sewer lines, pump stations, and all of the related appurtenances required to convey
wastewater from the homes and businesses of customers to the wastewater treatment plant for
treatment. All of the wastewater transported by the collection system is treated at the Corpening
Creek Wastewater Treatment Plant, located at 3982 Hwy 226 South, Marion, NC, prior to
ultimate discharge into receiving water designated as Corpening Creek (Young's Fork Creek) in
the Catawba River Basin. This report summarizes the performance of the collection system and
Corpening Creek Wastewater Treatment Plant during Calendar year 2021.
Collection System
General Information
Facility/System Name:
Permit Number:
Operator in Responsible Charge (ORC):
Contact Information for ORC:
Total Miles of Pipe:
Miles of Pipe Cleaned During 2021
Number of Pump Stations:
City of Marion Wastewater Collection System
WQCS00075
Gary Cook, Utility Maintenance Superintendent
828-652-4224 [e-mail]
Approximately 85 (76 gravity and 9 force main)
9.82 miles (13% of the gravity portion)
22
Wastewater Conveyance and Sanitary Sewer Overflows (SSO)
During calendar year 2021, approximately 336.7 million gallons of wastewater were conveyed to
the Corpening Creek Wastewater Treatment Plant. Sanitary sewer overflows (SSO) totaling
88,480 gallons, or 0.03% of the total gallons conveyed, were reported to the NC Department of
Environmental Quality (DEQ). The SSO gallons per month were as follows:

MONTH
NUMBER OF SSOs
TOTAL GALLONS
GALLONS TO
SURFACE WATER
January
0
0
0
February
0
0
0
March
1
4,620
4,620
April
0
0
0
May
0
0
0
June
0
0
0
July
0
0
0
August
1
4,810
4,810
September
0
0
0
October
3
79,050
79,050
November
0
0
0
December
0
0
0
Each SSO is summarized separately below:
Event #1
Date: March 25, 2021
Gallons: 4,620
Location: Clinchfield Pump Station (Forsythe Street)
Surface Water Name: Unnamed tributary of Lake James in the Catawba River Basin
Cause of the SSO: Inflow and infiltration from a severe natural condition (excessive rain)
Corrective Actions Taken: Performed pump and haul operations until high flows subsided.
Known Environmental Impact of the SSO: None
Event #2
Date: August 17, 2021
Gallons: 4,810
Location: Clinchfield Pump Station (Forsythe Street)
Surface Water Name: Unnamed tributary of Lake James in the Catawba River Basin
Cause of the SSO: Inflow and infiltration from a severe natural condition (excessive rain)
Corrective Actions Taken: Performed pump and haul operations until high flows subsided.
Known Environmental Impact of the SSO: None
Event #3
Date: October 7, 2021
Gallons: 8,920
Location: Clinchfield Pump Station (Forsythe Street)
Surface Water Name: Unnamed tributary of Lake James in the Catawba River Basin
Cause of the SSO: Inflow and infiltration from a severe natural condition (excessive rain)

Corrective Actions Taken: Performed pump and haul operations until high flows subsided.
Known Environmental Impact of the SSO: None
Event #4
Date: October 7, 2021
Gallons: 70,000
Location: 1146 Rutherford Road
Surface Water Name: Young's Fork Creek
Cause of the SSO: Inflow and infiltration from a severe natural condition (excessive rain), roots,
and pipe failure. A pipe failure caused a restriction in the already surcharged pipe.
Corrective Actions Taken: Repaired broken 8" pipe.
Known Environmental Impact of the SSO: None
Event #5
Date: October 8, 2021
Gallons: 130
Location: 348 Resistoflex Road
Surface Water Name: Catawba River
Cause of the SSO: Severe natural condition (flooded river) caused the pipe to fail.
Corrective Actions Taken: Repaired broken 8" pipe.
Known Environmental Impact of the SSO: None
Corpening Creek Wastewater Treatment Plant
General Information
Facility Name:
Permit Number:
Operator in Responsible Charge (ORC)
Total Gallons Treated in 2021:
Average Monthly Flow:
Average Daily Flow:
Maximum Daily Flow:
Minimum Daily Flow:
Corpening Creek Wastewater Treatment Plant
NCO031879
Tim Horton, WWTP Superintendent
828-652-8843 thorton ,marionnc.org
336.7 MG
28.1 MG
0.9 MGD
1.7 MGD
0.6 MGD

Description of Treatment Processes
The Corpening Creek WWTP has a total capacity of 3.0 MGD and the unit processes include
screening, grit removal, primary clarification, aeration, lime addition, secondary clarification,
tertiary filters, gravity sludge thickeners, chlorine disinfection, sulfur dioxide dechlorination, and
step aeration. Solids are treated by aerobic digestion before being stored and eventually land
applied under permit WQ0019960. Treated wastewater effluent is discharged into Corpening
Creek (Young's Fork Creek) under permit NC0031879.
Summary of Permit Violations During 2021
A total of seven permit violations were reported to the NC Department of Environmental Quality
(DEQ) during calendar year 2021. Each violation is summarized below:
Violation #1
Date: February 17, 2021
Type of Violation: Primary Clarifiers are non -operational.
Cause of Violation: Equipment is in dis-repair.
Corrective Actions Taken or Being Taken: A condition assessment of the primary clarifiers will
be performed, in conjunction with a comprehensive assessment of the entire WWTP, to
determine if the primary clarifiers should be repaired, replaced, converted, or eliminated. The
assessments will be performed as soon as reasonably practicable.
Known Environmental Impact of the violation: None
Violation #2
Date: February 17, 2021
Type of Violation: Secondary Clarifier #1 was non -operational.
Cause of Violation: Mechanical failure of equipment (broken drive unit and center column)
Corrective Action Taken: Drive unit and center column were replaced.
Known Environmental Impact of the violation: None
Violation #3
Date: February 17, 2021
Type of Violation: No backup RAS pump in operation.
Cause of Violation: Pump breakdown.
Corrective Action Taken: A new RAS pump has been purchased and an installation contractor is
currently being procured.
Known Environmental Impact of the violation: None

Violation #4
Date: April 4, 2021
Type of Violation: Exceeded weekly average Total Suspended Solids limit
Cause of Violation: Settling process was upset due to high flows during a rain event while only
one secondary clarifier was available for use.
Corrective Actions Taken: Followed standard operating procedures for high flow operations and
cleaned out contact chambers once flow had decreased. All solids from the contact chambers
were returned to the plant influent during the cleaning process.
Known Environmental Impact of the violation: None
Violation #5
Date: August 21, 2021
Type of Violation: Exceeded geometric mean limit for fecal coliform
Cause of Violation: Plant processes were upset due to high flows from a rain event.
Corrective Actions Taken: Followed standard operating procedures for high flow operations and
cleaned out contact chambers twice. All solids from the contact chambers were returned to the
plant influent during the cleaning processes.
Known Environmental Impact of the violation: None
Violation #6
Date: August 31, 2021
Type of Violation: Exceeded monthly average Ammonia Nitrogen limit
Cause of Violation: Plant processes were upset due to high flows from a rain event.
Corrective Action Taken: Followed standard operating procedures for high flow operations and
cleaned out contact chambers twice. All solids from the contact chambers were returned to the
plant influent during the cleaning processes.
Known Environmental Impact of the violation: None
Violation #7
Date: December 25, 2021 and December 31, 2021
Type of Violation: Exceeded weekly and monthly average limits for biochemical oxygen
demand (BOD)
Cause of Violation: Both exceedances were caused by a high BOD concentration on 12/21/21.
The cause of the high BOD concentration on 12/21/21 is unknown.
Corrective Actions Taken: The contact chamber was cleaned out as a precautionary measure.
All solids from the contact chambers were returned to the plant influent during the cleaning
process.
Known Environmental Impact of the violation: None

Public Notification
This report is available for viewing on the City of Marion's web site (www.marionnc.org), at
City Hall (194 N. Main Street), and at the Public Works Facility (94 Shop Drive). A statement
of availability will be mailed to each customer.
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 report will be made available to the customers of the named
system.
�J w
J. Brant Sikes
Public Works Director
City of Marion Public Works Department
Date
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