WQCS00013_Response To nov-2021-dv-0048_20210211

UTILITIES DEPARTMENT
February 11, 2021
Mr. Scott Vinson
Regional Supervisor
NCDEQ— Water Quality Regional Operations Section
Raleigh Regional Office
1628 Mail Service Center
Raleigh, NC 27699-1628
CERTIFIED MAIL (7012 0470 0001 7158 8870)
Subject: Notice of Violation (NOV-2021-DV-0048) Remedial Actions
Dear Mr. Vinson:
On February 2, 2021, the Town of Cary Utilities Department received a Notice of Violation (NOV) letter dated
January 22, 2021 from the North Carolina Department of Environmental Quality, Division of Water Resources
— Raleigh Regional Office a sanitary sewer overflow (SSO) that occurred on December 6, 2020. The NOV letter
required a written response within 15 business days from receipt of the letter with steps taken to abate the
SSO violation.
The Town appreciates the opportunity to provide the following remedial actions performed because of the
following SSO incident and includes actions to prevent future occurrences.
Location Incident # Date Gallons I _ Action 1
Green Level Church Road 202003427 12/6/2020 1,145 NOV
north of Mills Park Drive ,
On December 6, 2020, the Town of Cary was notified by a citizen of water coming from the ground along
Green Level Church Road north of Mills Park Drive in Cary. Cary staff immediately responded to investigate
the leak. Upon arrival staff identified water as a sewer leak on a 24-inch ductile iron force main that serves
both the Morris Branch Pump Station and Kit Creek Pump Station. Based on onsite measurements and
consultation with the sewer spill estimation guidance on NC DEQ's website, the leak was occurring at
approximately 5 gallons per minute. Cary staff immediately called on resources and developed a plan to dig a
receiving pit to collect the spilling wastewater. A portable pump was installed in the pit to pump the
wastewater to a nearby gravity sewer manhole. This proactive effort stopped the discharge from reaching the
nearby Panther Creek surface waters. The initial wastewater that was not intercepted by the receiving pit,
collected in a low-lying area where any standing water was pumped back to the sewer system for treatment.
Rainfall the following day of sewer spill assisted with our site cleanup efforts.
TOWN OCARY
400 James Jackson Avenue • Cary, NC 27513 • PO Box 8005 • Cary, NC 27512-8005
tcl 919-469-4000 • fax [phone] • www.townofcary.org

Mr. Scott Vinson
February 11, 2021
Page 2.
With careful planning and having existing pipeline provisions in place, wastewater flow was diverted from the
Morris Branch and Kit Creek Pump Stations to inactivate the shared force main. The wastewater was diverted
to the Durham County Triangle Wastewater Treatment Plant for treatment while the Town of Cary obtained
the services of Moffat Pipe to excavate and repair the force main. After excavation, a pin -hose leak was
identified close to a joint in a section of pipe. Moffat Pipe replaced a 20-foot section of pipe to make a
permanent repair. The pipe upstream and downstream of the Teak was closely inspected and showed very
little to no corrosion. The pipeline repair was complete on December 18, 2020 and was tested to ensure there
were no additional Teaks. This repair which included wastewater treatment service by Durham County had a
total cost of $284,926.87.
The Town's proactive measure in maintaining a flexible utility infrastructure and mutual aid agreements,
allowed us to work with our neighboring utility, significantly reducing the potential volume of the sewer spill in
this event. The Town of Cary appreciates the opportunity to provide this additional information and remedial
actions taken to prevent future occurrences of sewer overflows at this location. If there are any questions,
please feel free to contact me at [phone].
Sincerely,
Donald Smith
Wastewater Collection System Manager/ORC
Cc: Jamie Revels, P.E., Utilities Director
Scott Hecht, Public Works Director
Jim Hallowes, Operations Manager
Enclosed: NC DEQ NOV Letter (NOV-2021-DV-0048)
5-day SSO Incident Report 202003427