WQCS00005_NOV-2019-DV-0315 Response_20190905

WATER MANAGEMENT
CITY OF DURHAM
September 5, 2019
Mr. Rick Bolich
Assistant Supervisor
Water Quality Regional Operations Section
Raleigh Regional Office
NCDEQ, Division of Water Resources
3800 Barrett Drive
Raleigh, N.C. 27609
Subject: NOV-2019-DV-0315, Permit No. WQCS00005
City of Durham Collection System, Durham County
Dear Mr. Bolich,
NC Dept of Environmental Quality
SEP - 5 2019
Raleigh Regional Office
This letter is in response to your notice dated August 14, 2019 which was received by the City on August 22,
2019. The August 10 letter states that the City of Durham is provided an opportunity to present evidence and
justification to demonstrate that the proposed civil penalties for Notice of Violation/Notice of Intent to Enforce
(NOV-NOI) should not be assessed for the sanitary sewer overflows (SSOs) which occurred in the City's sewer
collection system between April 1, 2019 and June 30, 2019.
As requested, the City of Durham, Department of Water Management (DWM) is providing information about
three incidents which occurred between April 1311 and June 81h which support the City's position that despite
meeting all the conditions of the City's Collection System permit including site visits, inspections and easement
maintenance, these events were exceptional, unintentional, and temporary and beyond the City's exercise of
reasonable control.
Incident # 201900725 — 5242 North Roxboro Road — A ril 13 2019
On April 13'h, manhole #24184 at 5241 N. Roxboro Road overflowed, with an estimated 594,000 gallons of
wastewater discharging into the Eno River. Over a three-day period (April 12-14), this portion of Durham
received over 4 inches of precipitation, causing flooding along the Eno River and subsequently flooding the
manhole. Once the river receded and flows returned to normal, City staff were able to conduct CCTV work in
the area and confirm the system was operating properly. The City's Stormwater Services Division conducted
post flooding ammonia testing to help determine the extent of the spill and to determine that the site had been
restored to normal conditions. This area is one segment of the Eno outfall pipeline replacement project which is
currently under construction. The project includes raising all the manholes along the outfall to above flood
stage.
As required, a news release was issued within the 24-hour window. The cost to remediate this spill was $120.61
Incident # 201900937 —1001 Leon Street — May 15, 2019
On May 151h, manhole #20733 at 1001 Leon Street overflowed, with an estimated 1,500 gallons of wastewater
discharging into the unnamed tributary of the Ellerbe Creek. This overflow was due to roots growing into the
pipeline creating a blockage. Crews used a root cutter to remove the blockage and then jetted the line with a
flush truck to clear the blockage from the main. A 4-inch pump was set-up downstream to remove the fluids and

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the collected wastewater was pumped back into the sanitary sewer system. Staff also removed and replaced
the contaminated dirt, re -seeded the area, and applied straw as a covering.
City of Durham crews have conducted additional cleaning of the lines above and below the incident location and
have used CCTV trucks ensure that no debris was left inside the main.
The City's Stormwater Services Division responded and conducted ammonia testing to help determine the
extent of the spill and to advise when the site returned to normal conditions. There was no observed harm to
plants, animals, aquatic life or natural resources. No danger to public health or damage to private property
occurred. Staff will continue to monitor this portion of the collection system for root intrusion and If the roots
become an ongoing issue, the area will be included in the City's root control contract.
As required, a news release was issued within the 24-hour window. The cost to remediate this spill was
$3,065.38
Incident ## 201901065 — 4010 Dover Road — June 8.2019
On June 81h, manhole ##09943 at 4010 Dover Road overflowed, with an estimated 19,500 gallons of wastewater
discharging into the unnamed tributary of the Third Fork Creek. This overflow was due to a manhole Insert
falling into the invert at the bottom of the manhole blocking the flow in the line. Crews brought in a Vac -all
Truck to pump down the manhole and remove the fallen insert. A 4-inch pump was placed in the line to remove
the fluids from the manhole and pump the wastewater back into the collections system.
The City's Stormwater Services Division responded and conducted ammonia testing to help determine the
extent of the spill and to advise when the site returned to normal conditions. There was no observed harm to
plants, animals, aquatic life or natural resources. No danger to public health or damage to private property
occurred.
As required, a news release was issued within the 24-hour window. The cost to remediate this spill was
$6,752.66
Ongoing City -Wide Measures to Reduce the Occurrence of SSO's
The City has several programs in place to reduce and/or prevent the occurrence of SSOs. The City has
implemented a CMOM plan that expands and enhances its existing programs.
System Flushing and Inspection: The City routinely contracts flushing, CCTV inspection, smoke testing and
manhole inspections of portions of the sewer collection system. The City is completing the inspection of the
collection system systematically through City defined basins.
Additionally, the City ensures the requirements of the collection system permit are met by deploying City
crews to flush at least 10% of the collection system annually with a goal of exceeding the requirement by at
least 2 to 5% each year. The City measures the flushing on a fiscal year basis. For the FY 2020 fiscal year
(August 2019) the City has cleaned 3.43% of the system.
Sewer Rehabilitation Program: The City has an active Sewer Rehabilitation Program. The program includes
flow monitoring (25 permanent monitors), CCTV inspection, manhole inspection, easement mowing, field
inspections and investigations, point repairs, line replacement, root and grease abatement and cured -in -
place manhole and line rehabilitation. There are 4 employee positions dedicated to the City's system
rehabilitation programs in the Utility Engineering Division of the Department of Water Management (DWM).
This workgroup handles flow monitoring and system data management and contract preparation,

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administration and inspections. There are 20 employee positions in our Sewer Rehabilitation workgroup in
the Water & Sewer Maintenance (WSM) Division of DWM. This group performs CCTV inspections, hydraulic
cleaning activities, mowing and manhole inspection and repair. They respond to blockages and overflows.
WSM does contract inspections as well. In addition, crews from the Main Line workgroup of WSM perform
point repairs, line replacements and some cured -in -place lining. The City spends more than $5,000,000 on
Sewer Rehabilitation projects annually as a part of its Capital Improvements Programs.
Fat, Oils and Grease Program (FOG): The department's FOG education and outreach effort is conducted by
3.0 FTEs (staff shared 50/50 with the Industrial Waste Control Program). In addition to working closely with
the Durham County Health Department, staff routinely inspect over 800 food service establishments (FSEs)
annually to ensure appropriate cleaning and maintenance of grease interceptors. Staff participates in a
number of community events (Earth Day, CenterFest, and Landlord Workshops) as well as neighborhood
meetings to increase awareness of what is appropriate to put in the sewer system. FOG staff conducts post-
SSOs follow-up education and enforcement as necessary. The City also invests more than $35,000 per year
in advertising (TV commercials, social media, etc.) regarding the proper disposal of FOG.
Summary
Based upon the documented information provided above regarding these incidents, the City believes that
overflows were exceptional, unintentional, temporary and caused by factors beyond the City's/department's
reasonable control. The City actively manages, operates and maintains its system in such a manner as to meet
all the requirements of the Collection System permit. As detailed above, the City systematically inspects flushes
and rehabilitates its wastewater collection system. The department works actively to educate the community
regarding what should and should not be discharged into the City's sewer collection system.
Department staff welcomes the opportunity to meet with you and your staff to review our program and discuss
constructive ways to improve what we are already doing in the City of Durham. If you have any questions or
need any additional information please do not hesitate to contact me at [phone] or via email at
[e-mail].
Sincerely, r
Donald F. Greeley, PE, LS
Director
Attachments
Cc: Danny Smith, Supervisor, DEQ - Water Quality Regional Operations Section, Raleigh Regional Office
Junior Mobley, Superintendent, Water & Sewer Maintenance
Vicki Westbrook, Assistant Director
Stephen Buchanan, Assistant Director
Jerry Morrone, Engineering Supervisor