WQ0023896_Inspection_20241017

October 17, 2024

Vice-Chancellor George E. Battle, III
University of North Carolina at Chapel Hill
Campus Box 1650
Chapel Hill, NC 27599-1650

Subject: Compliance Evaluation Inspection
UNC - Bingham Facility WWTF
Permit: WQ0023896
Facility:UNC - Bingham Facility WWTF
OrangeCounty

Dear Vice-Chancellor Battle:

On September 17, 2024, Tyler Clark, Kurtis Waibel, and Lauren Willhite from the Division of Water Resources,
Raleigh Regional Office visited your wastewater treatment system to evaluate compliance with the subject non-
discharge permit referenced above (WQ0023896). The assistance provided by Larry Daw, James Smith, and
Christian Teague of UNC-CH during the inspection was greatly appreciated.

The inspection included:
• Review of the permit.
• Review of the facility/owner information.
• Review of the Non-Discharge Monitoring Reports (NDMR), Non-Discharge Application Reports (NDAR-1),
and Groundwater Monitoring Reports (GW59); and
• Inspection of the permitted components.

The Permit was issued June 12, 2020, and expires on November 30, 2026. An application to renew the permit will
be provided to you by the permitting group as the expiration date approaches. When you receive it, please
complete the application for renewal, and submit it following the instructions on the application.

Permit WQ0023896 authorizes the operation of a 3,556-gallon per day (GPD) wastewater treatment and irrigation
facility to serve the Bingham Facility WWTF, with no discharges to surface waters. According to the permit, the
system consists of the following:

• Collection system – 540 linear feet of 8-inch gravity sewer and associated piping, valves, controls, and
appurtenances.
• Treatment system – 3,356 gallon per day (GPD) system consisting of an 8,000-gallon baffled septic tank
with an effluent filter; a 2,100-gallon septic tank lift station with two 20 gallons per minute (GPM,), two
0.5 horsepower (hp) pumps; a 4,-000-gallon recirculation tank with two 55 GPM 0.5 hp pumps; two
AdvanTex AX100 textile media packed bed filters; a 60-degree v-trapezoidal flume with ultrasonic level
Docusign Envelope ID: 75464014-52F0-4601-B2CA-078FD19D9786

George E. Battle, III
WQ0023896
October 16, 2024 Page 2 of 3

sensing; a liquid sodium hypochlorite disinfection system with a 55-gallon chemical storage tank and two
7.1 gallon per hour (GPH) positive displacement peristaltic chemical feed pumps; a 525 gallon contact
tank; and all associated piping, valves, controls, and appurtenances.
• Wastewater Irrigation System – a 1,122,440-gallon clay-lined wet weather storage basin; a 1,495-gallon
wastewater pump station with two 158 GPM submersible pumps, a 5.72-acre irrigation area composed of
four drip irrigation zones with a total of 19,068 emitters each rated at 0.9 GPH; and all associated piping,
valves, controls, and appurtenances.

Inspection Findings

The following observations were made by the inspection team:

Collection System

1. The collection system was in good condition and did not appear to have corrosion, cracks, or loose
fittings. Mr. Smith indicated that the system is regularly inspected as part of the routine operation of the
facility.

Treatment System

1. Flow into the storage/treatment lagoon is monitored continuously and the flow meter was calibrated on
8/7/2023 by Clearwater, Inc.
2. The embankment surrounding the treatment area was well maintained and mowed and otherwise
controlled and accessible as per 15A NCAC 02T .0507(g).

Wastewater Irrigation System
1. A mild precipitation event occurred during the date of the inspection, which precluded the operation of
the irrigation system.
2. The facility has four separate drip fields, one grassy (Field 1) and three wooded (Fields 2, 3, & 4). These
fields had the appropriate fencing as required by permit. The fields normally receive the same volume of
water during each application, according to non-discharge application reports (NDAR) submitted for this
facility. An inspection performed on October 24, 2023, suggested the clearing of excessive underbrush
and fallen trees in Fields 2, 3, & 4. During the Fall of 2023, a university landscaping team began clearing in
Field 4. Unfortunately, the landscaping team did not follow the ORC’s instructions and utilized heavy
equipment, which resulted in significant damage to the drip lines. The damage was so extensive that use
of the field for irrigation has been halted until repairs could be made. The repairs had not been initiated at
the time of the inspection, and the inspectors observed many broken, severed, and stretched drip lines.
3. The removal of vegetation from Field 4 was observed to have contributed to increased overland flow
resulting in scouring and erosion of the ground surface throughout the drip field. This increased overland
flow has exposed many drip lines. The overland flow has also led to the accumulation of organic debris at
the edge of Field 4. This debris has dammed surface flow and resulted in standing water for brief periods
of time in the field. The ORC was told to implement appropriate erosion control methods to reduce
erosion and standing water, and further damage to the drip field. Clearing in fields 2 and 3 has not begun,
Docusign Envelope ID: 75464014-52F0-4601-B2CA-078FD19D9786

George E. Battle, III
WQ0023896
October 16, 2024 Page 3 of 3

pending repairs to Field 4. The ORC states that different clearing methodologies and strategies will be
used to prevent the damage that occurred in Field 4.
4. A review of the facility’s monthly NDAR-1s indicate that Fields 2, 3 and 4 have the temporary capacity to
absorb the irrigation no longer being applied on Field 1. However, the increased irrigation to Fields 2-4 is
resulting in an increase in the 12-month floating totals for each of these fields. The 12-month floating
totals are within permit limits but will likely be exceeded if Field 1 is not brought online soon. The
1,122,440-gallon clay-lined wet weather storage basin has the capacity to accommodate excess
wastewater. As part of routine groundwater monitoring and reporting on GW-59 forms, the facility has
notified the Division of permit exceedances for fecal coliform in monitoring well MW-4 for several years.
This well is upgradient of any spray fields and no plausible explanation exists for the permit exceedances.
The inspectors visited the well an found no obvious defects. One proposal put forth by the operators is
that the contamination is migrating from off-site, possibly from a failing septic system across the road.

Plans and Records
Review of the permit records indicates that the list of permit affiliations and designated operators is up to
date. During the inspection, required plans and records were available as required by the permit. A review of
supporting documents for two randomly selected months was performed and no discrepancies were identified.

Within 30 days of the receipt of this letter, provide an update to the status of repairs to Field 4 to prevent permit
violations of the 12-month floating totals for Fields 1-3. In addition, provide an update on the clearing status of
excess vegetation in fields 2 and 3.

If you have questions or comments about this inspection or the requirements to take corrective action (if
applicable), then please contact Tyler Clark at 919-791-4242, or [e-mail].

Sincerely,

Michael Hall, Regional Supervisor
Water Quality Regional Operations Section
Raleigh Regional Office
Division of Water Resources, NCDEQ

Attachments: Compliance Inspection Report

Ec: Larry Daw, Environmental Compliance Officer, UNC Chapel Hill
Laserfiche
Docusign Envelope ID: 75464014-52F0-4601-B2CA-078FD19D9786