WQCS00005_NOV-2021-DV-0172 Response_20210412

WATER MANAGEMENT
CITY OF DURHAM
April 12, 2021
Mr. Scott Vinson, Regional Supervisor
Water Quality Regional Operations Section
Raleigh Regional Office
NCDEQ, Division of Water Resources
3800 Barrett Drive
Raleigh, N.C. 27609
Subject: NOV-2021-DV-0172, Permit No. WQCS00005
City of Durham Collection System, Durham County
Dear Mr. Vinson,
APR 12 2021
INC DENR Raleigh Regional Office
This letter is in response to your notice dated March 22, 2021 which was received by the City of Durham on March
29, 2021. The March 22, 2021 letter states that the City of Durham is provided an opportunity to present evidence
and justification to demonstrate that the proposed civil penalties for the Notice of Violation (NOV) should not be
assessed for the sanitary sewer overflows (SSOs) which occurred in the City's sewer collection system between
February 1, 2021 and February 28, 2021.
As requested, the City of Durham, Department of Water Management (DWM) is providing information about two
incidents which occurred during this timeframe which will 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, temporary and beyond the City's exercise of reasonable control.
DWM staff consider that it is especially important to note Incident # 202100579 was caused by vandalism in an
area that DWM had taken a number of precautions to secure the manhole lids. Additionally, the attached map
shows that the SSOs are dispersed throughout Durham's service area.
Incident # 202100387 — 3814 Danube Lane — February 2 2021
On February 2"d a clean out at 3814 Danube Lane overflowed, with an estimated 615 gallons of wastewater
discharging into Eno River Tributary #1. This overflow occurred due to a blockage in the sewer main caused by
debris in the line. Water and Sewer Maintenance staff responded by using a high-pressure jet to remove the
blockage from the main, cleaning the lines with a VAC -ALL combo truck. Crews dammed up the nearby creek and
flushed using dechlorinated water from a nearby hydrant; the untreated wastewater was pumped back into the
collection 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. No immediately visible adverse
environmental impacts or hazards to persons or property occurred.
City of Durham crews have followed up by cleaning the lines above and below the incident location and using CCTV
trucks. As required, a news release was issued within the 24-hour window. The cost to remediate this spill was
$3,311.25.

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Incident # 202100579 -- 2816 Ross Road — February 16 2021
On February 16th a manhole near 2816 Ross Road overflowed, with an estimated 13,750 gallons of wastewater
discharging into an unnamed tributary of Little Lick Creek. This overflow occurred due to a blockage in the sewer
manhole caused by vandalism. Water and Sewer Maintenance (WSM) staff responded to the site and discovered
that several of the manhole lid bolts that had been installed to prevent vandalism had been removed or withdrawn
to a point that allowed rocks, tree branches and other debris to be intentionally thrown into the manhole. WSM
crews on -site removed the debris and cleaned the lines with a VAC -ALL combo truck above and below the effected
location. The creek was dammed and the untreated wastewater was pumped back into the collection system. Due
to the heavy rainfall, staff did not have to use dechlorinated water from a hydrant for creek flushing. Upon further
investigation, it was found that two additional manholes upstream of the overflow manhole had also been
tampered with; at these sites the bolt down lid restraints had also been backed out to gain access. To increase the
level of security on this area, DWM has installed cameras to observe the area around the manholes that have been
targeted for vandalism. The goal is to deter further instances of vandalism and possibly identify the persons
tampering with and damaging the City's collection 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. No immediately visible adverse
environmental impacts or hazards to persons or property occurred.
City of Durham crews have followed up by cleaning the lines above and below the incident location and using CCTV
trucks. As required, a news release was issued within the 24-hour window. The cost to remediate this spill was
$3,008.78. Additional costs include the purchase and installation of the security cameras at $499 each and the
monthly cells service costs for the cameras of $74 ($37 each).
Ongoing City-wide Measures to Reduce the Occurrence of SSOs
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 2021 year to date, the
City has cleaned 9.67% of the system. As operations continue to normalize post-Covid-19, staff will dedicate
more time to this program.
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 DWM. This workgroup handles flow monitoring and system
data management and contract preparation, administration and inspections. There are 21 employee positions
in our Collections Systems Maintenance 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 department established the Lift Station Maintenance Division in 2018 to focus oversight and

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maintenance of the 65 lift stations throughout the service area and the 136 ARVs in the system. This 14-
member work group conducts the required daily/weekly inspections and associated preventive maintenance
activities. 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 and wipes.
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. As noted, the department has taken several steps to prevent vandalism in the Ross Road area
and will continue to monitor the site via security cameras. 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
Don.Greeleydurhamnc.eov.
Sincerely,
Donald F. Greeley, Director, PE, P
Attachments
c: Jason Robinson, DEQ— Water Quality Regional Operations Section, Raleigh Regional Office
Junior Mobley, Superintendent, Water & Sewer Maintenance
Vicki Westbrook, Assistant Director
Jerry Morrone, Utility Engineering Manager, Sr.