WQCS00005_NOV-2020-DV-0266 Response_20200701

I M WATER MANAGEMENT
CITY OF DURHAM
July 1, 2020
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-2020-DV-0266, Permit No. WQCS00005
City of Durham Collection System, Durham County
Dear Mr. Vinson,
a IF
JUL _ 2 N10
NC DENR RaleIgh Regional Office
This letter is in response to your notice dated June 10, 2020 which was received by the City on June 18, 2020. The
June 10th 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 May 1, 2020 and May 31, 2020.
As requested, the City of Durham, Department of Water Management (DWM) is providing information about
twelve 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.
Incident ## 202001382 —1708 Woodburn Road — May 17 2020
On May 17th, City of Durham crews found manhole at 1708 Woodburn Road had overflowed with an estimated 264
gallons of wastewater discharging into an unnamed tributary of the Sandy Creek. This overflow was caused by a
buildup of debris and roots in the line which restricted flow inside the main. Crews used a high-pressure jet and
cutter head to remove the blockage and then cleaned the line with a flush truck to force the debris from the main.
The closest hydrant was used to flush the creek area near the spill. Crews pumped the contaminated water back
into the sanitary sewer 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 to be sure that there was no remaining debris inside the main that would cause additional issues. because
the blockage was related to a root issue the area will be included in a future root control contract to try to prevent
any reoccurring issues in the future.
As required, a news release was issued within the 24-hour window. The cost to remediate this spill was $2,947.57.

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Incident ## 202001727 - 25 Phauff Court — May 29, 2020
On May 29sh a sewer overflow was reported at 25 Phauff Court, with an estimated 7,500 gallons of wastewater
discharging into an unnamed tributary of the Little Lick Creek. This overflow was caused by a build up of debris in
the line restricting flow inside the mainline. Crews responded by using a high-pressure jet to remove the blockage
and then cleaned the line with a flush truck to force the debris from the main, then used the nearest hydrant to
flush the creek area near the spill. Crews pumped the contaminated water back into the sanitary sewer 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 to be sure that there is no remaining debris inside the main that would cause additional issues.
As required, a news release was issued within the 24-hour window. The cost to remediate this spill was $4,802.37.
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 2020 year to date, the
City has cleaned 14.10% 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 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
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

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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
Don.GreeleY durhamnc.P,ov.
Sincerely,
Donald F. Greeley, Director, PE, PIS Director
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, Engineering Supervisor