NC0021474_Annual Report_20230831

City of Mebane
Wastewater Collection and Treatment Facility
For the Fiscal Year July 1, 2022 — June 30, 2023
Introduction
This report is produced in compliance with House Bill 1160 passed by the General Assembly of the State of
North Carolina requiring that all entities that own or operate wastewater collection and treatment systems make
an Annual Report available to their customers. This report must include information regarding how well the
system operated, what violations occurred, and other pertinent information. This report complies with these
requirements.
The City of Mebane operates a wastewater treatment facility and a sewage collection system that collects and
transports the sewage to the facility.
Following are the professionals designated by the state as the "Operator in Responsible Charge" (ORC) of the
respective systems and permits for the systems:
City of Mebane Wastewater Treatment Facility
635 Corregidor Road
Phone [phone]
NPDES Permit No. NC0021474
Operator in Responsible Charge (ORC) — Dennis J. Hodge
Mebane Public Utilities
Sewage Collection System
636 Corregidor Road
Phone [phone]
Collection System Permit No. WQCS00081
Operator in Responsible Charge (ORC) — Greg Barts
We certify under penalty of law that this report is complete and accurate to the best of our knowledge. Copies
will be available at the Wastewater Treatment Plant, the Public Works Building, the Glendel Stephenson
Municipal Building, and on the City of Mebane website at h!tps:Hcityofinebanenc. og v/departments/water-
resource-recovery-facility/.

City of Mebane Annual Report - Page 2
System Overview
Every day an average of nearly 1.6 million gallons of sewage is generated in our homes, commercial
establishments, and industries that must be collected, transported, and treated to very stringent standards before
it is released back into our environment through our waterways. This service is provided by the City and is
funded almost entirely from the user charges that are paid monthly by our customers.
The sewage collection and wastewater treatment facility of the City of Mebane begins with over 6,410
connections that serve homes, commercial establishments, and industries. Nearly all of the sewage or
wastewater that is generated by customers flows by gravity through sewers that range from 6 to 16 inches in
diameter. Mebane operates 126.45 miles of these gravity sewer lines. During this reporting period,
approximately 14.83 miles of these lines were cleaned.
As the lines leave neighborhoods, they increase in size to accommodate the flows that are collected from the
many areas that are served. These sewers generally follow terrain to take advantage of gravity flow but at certain
points pumping stations are used to transfer the flow to different basins. The City currently operates 21
pumping stations that range in capacity from 10 to 1749 gallons per minute.
The purpose of the collection system is to transport the wastewater to the wastewater treatment facility so it can
be processed and returned to our waterways with minimal environmental impact. The wastewater treatment
facility is permitted to process up to 2.5 million gallons of wastewater per day.
The wastewater treatment facility is complex, using physical, chemical, and biological processes to treat the
wastewater. The wastewater is screened to remove large, suspended materials, but the heart of the plant is a
biological process that uses bacterial cultures to remove most of the suspended and dissolved wastes that are
produced within the City. This biological, activated sludge process is sensitive to temperature, high flows
produced by rainfall leaking into sewers, and toxic discharges that can be produced by industries or even homes.
This sensitivity makes the wastewater facility susceptible to process upsets that can result in exceeding
limitations permitted by regulatory authorities.
The permitting of treated wastewater discharges is based on a "7Q10" stream flow, or the lowest seven-day
stream flow expected every ten years. However, permit limits that are issued to protect the stream at low flow
(less assimilation), apply 24 hours per day and 365 days per year. Since Mebane's limits are calculated for
discharging to a small stream, our limitations are extremely stringent. North Carolina has some of the most
stringent stream standards in the country. Mebane WWTP discharge constitutes over 90% of the stream at the
lowest stream -flows. However, when periods of rain create high stream flows and make treatment plant
operations difficult, the treatment facility must continue to be compliant with dry weather limitations.
The City of Mebane's treatment plant operates under a National Pollutant Discharge Elimination System
(NPDES) permit. The NPDES permit includes monitoring requirements and discharge limitations, some of
which vary with seasons and have different maximums for daily values, weekly averages, monthly averages, and
quarterly averages. Some limitations protect streams from oxygen depletion, such as biochemical oxygen
demand (BOD) and ammonia -nitrogen (which exerts oxygen demand over a delayed yet prolonged basis). Some
standards/limitations are to protect aquatic life in the receiving stream, such as metals like cadmium or mercury
or other pollutants like fluoride or chlorine. Since aquatic life is more sensitive than humans to some pollutants,
some standards are as low as 12 parts per trillion* and, in many cases, are lower than drinking water standards.
* To help comprehend how small one part per trillion is: One part per trillion corresponds to one
minute in 2, 000, 000 years, or a single penny in $10, 000, 000, 000.

City of Mebane Annual Report - Page 3
Compliance with the permit requires that our laboratory conduct over 4,000 tests per year all of which must
meet the NPDES permit requirements. To accidentally drop a sample or not analyze it within a specified period
can result in a violation. There are some pollutants such as fluoride, mercury, and cadmium that the operators of
the wastewater treatment facility have no control over and can only be regulated through controlling the
discharges of industries and households. There are also times that maintenance on major equipment needs to be
performed and that can cause exceedances as well.
During the 2022-2023 fiscal year, the Water Resources Department treated over 579 million gallons and
returned it to our streams. We are proud of the outstanding performance of the facility that was made possible by
the dedicated efforts of the professionals who operate, maintain, and conduct tests for the facility. During this
reporting period, the wastewater treatment facility reported 2 exceedances of the NPDES permit. These
exceedances were reported to the State of North Carolina in compliance with reporting regulations and are
summarized in Table 1. All exceedances were addressed as expeditiously as possible. There were no apparent
environmental impacts associated with these exceedances. Wastewater flow amounts are summarized in Table
2.
Table 1: Wastewater Treatment Facility
Date
Parameter
Number of
Exceedances
Exceedance Type
July 2022
Whole Effluent Toxicity
1
Quarterly Pass/Fail
October 2022
Whole Effluent Toxicity
1
Quarterly Pass/Fail
Table 2: Wastewater Flows
Summary of Wastewater Flows
MG (Million Gallons)
Julyl, 2021 -June 30, 2022
Average MG per day
Total MG
July 2022
1.472
45.642
August 2022
1.438
44.570
September 2022
1.460
43.793
October 2022
1.271
39.396
November 2022
1.308
39.242
December 2022
1.626
50.405
January 2023
1.744
54.059
February 2023
1.759
49.240
March 2023
1.633
50.631
April 2023
1.978
59.346
May 2023
1.692
52.462
June 2023
1 1.702
51.053
Total Year (MG)
579.821
Average Day (MG)
1.590
To reduce the impacts of rainfall on the City's collection system and wastewater treatment facility, the Public
Utilities Department continually monitors the condition of manholes and piping, addressing problems as quickly
as possible to minimize inflow and infiltration. Major I/I are a priority and are budgeted for and repaired as
funds allow.

City of Mebane Annual report — Page 4
Collection System Performance
The City of Mebane operates a sewage collection system comprised of 126.45 miles of gravity line, 3,091
manholes, 21 pump stations, and 27.78 miles of pressurized sewage force main. If sewage escapes from the
collection system, for whatever reason, and reaches a surface water body in an amount exceeding 1,000 gallons,
it must be reported to the news media. In addition, all spills of any volume reaching a water body must be
reported to the State. There was 1 sewage spill (overflow) to report for the 2022-2023 Annual Report timeframe
and is listed below.
Table 3: Collection System Sewage Spills
Date
Location
ApproximateGallons
Probable Cause
02.16.2023
1015 N Carr St
40,000
Pipe Failure
Collection system sewage spills, known as sanitary sewer overflows (SSO) can occur for many reasons. Tree
roots can enter sewer lines or foreign objects can be dropped into manholes or sewers causing obstructions.
Rainwater can also find its way into sewers, overloading lines and pump stations. In addition, pump stations can
fail for mechanical or electrical reasons.
Disposable Does Not Mean Flushable — Flushing garbage down the toilet can
result in messy and costly back-ups for property owners and can also lead to sewer
blockages that result in SSOs. Even items labeled "flushable" are best disposed of in
the trash rather than flushing them down the toilet.
Garbage such as paper towels, baby wipes and diapers, cotton swabs, syringes,
cleaning sponges and disposable toilet brushes, candy wrappers and other food
wrappers, sanitary napkins, toys, plastic items of any kind, rubber items such as
condoms and latex gloves, cigarette butts, hair, and kitty litter should not be flushed
down the toilet. These items should be placed in the trash.
Fats, Oils, and Grease (FOG) from households, restaurants, and commercial establishments can also cause
obstructions in the sewer system resulting in SSOs. A byproduct of cooking, FOG comes from meat, fats,
Wipe FOG residue from pans Pour FOG Into a container.
ar dishes with a paper bowel When full, thrdw it in the tM$h
I
\� Wive washing.
Don't pour FOG
into your sink or
todet.
IF
Place a strainer in the
sink drain to catch food
scraps and other solids.
Don't lel food scraps and
saiids go down the drain
lard, oil, shortening,
butter, margarine, food
scraps, sauces, and dairy
products. When washed
down the drain, FOG
sticks to the insides of
sewer pipes. Over time,
FOG can build-up, block
entire pipes, and lead to
serious problems. To
prevent any undue
introduction of FOG into
the wastewater collection
system of the City.

City of Mebane Annual report - Page 5
Mebane implements a FOG Policy designed to educate and enforce the proper disposal of FOG within the City.
The FOG policy is intended for all customers (residents, restaurants, and commercial establishments) that
discharge wastewater into the City's sanitary sewer with the aim of preventing grease related SSOs. Within the
FOG Policy, food service establishments are required to install and properly maintain an appropriately sized
grease trap or interceptor.
While food service establishments typically deal with larger volumes of FOG than residents, everyone must do
their part to prevent the introduction of FOG into the sewer system. To learn more about FOG, its impacts on
the sewer system, and its proper disposal, please visit the City's website at hqps://cityofinebanenc.gov/fats-oils-
greases-fo
Summary
The City of Mebane is proud that, given the age of our treatment facility and collection system, our permit
exceedances have been minimal. Circumstances, such as weather and vandalism, are beyond the control of
collection system and wastewater treatment facility staff. Therefore, despite the dedicated efforts of these
individuals, it can often be difficult to avoid spills and exceedances of the NPDES permit. The City's ultimate
goal is to have no permit exceedances or sewage spills. We want to provide the best possible service to our
customers while being fiscally responsible and good stewards of our environment. If more information is
desired, please contact our staff at 919-304-9215.

City of Mebane
Wastewater Collection and Treatment Facility
For the Fiscal Year July 1, 2022 — June 30, 2023
City of Mebane Wastewater Treatment Facility
635 Corregidor Road, Mebane, NC 27302
Phone [phone]
NPDES Permit No. NCO021474
Operator in Responsible Charge (ORC) — Dennis Hodge
Mebane Wastewater Collection System
636 Corregidor Road, Mebane, NC 27302
Phone [phone]
Collection System Permit No. WQCS00081
Operator in Responsible Charge (ORC) — Greg Barts
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 has been made available to the users or customers of the named systems
and that those users have been notified of its availability.
Dennis J. Hodge
Water Resources Director
City of Mebane
August 31, 2023
Date