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Raleigh Regional Office “44 e202 81 ONY
Raleigh Water Append [eWaUTONAUY Jo ydaq ony
August 18", 2022
Mr. Scott Vinson
Regional Supervisor
Water Quality Regional Operations Section
Raleigh Regional Office
Division of Water Resources NCDEQ
1628 Mail Service Center
Raleigh, NC 27699-1628
Re: Response to NOV-2022-DV-0199
Sanitary Sewer Overflows — June 2022
Permit No. WQCS00002
Dear Mr. Vinson:
Please allow this letter to serve as a response to the Notice of Violation & Intent to Issue Civil Penalty
document (NOV-2022-DV-0199) received on July 22"4, 2022. This document contains the narrative regarding
pending violation actions of (3) Sanitary Sewer Overflow (SSO) events, reported on the month of June 2022
within the City of Raleigh Collections System [1]. This document also provides exhibits as proof of our efforts to
mitigate each of the sewer events. The noticed events occurred while the City operated its collection system,
according to WQCS00002, dated June 6th, 2017. The permit includes the language outlined in footnote 1 and
applies to the SSOs upon which NOVs with the notice of intent (NOV-NOl) were based. This document will
establish a reasonable explanation of the actions taken to stop the spills; contain the released untreated
wastewater; collect the wastewater and reintroduce it to the collection system; and finally, restore the possible
environmental impacts brought by the release of the SSO events, listed with the intended NOV-NOI action.
Please find below, the additional information requested for the SSO events.
1. “The Director may take enforcement action against the Permittee for SSOs that must be reported to the
Division as stipulated in Condition IV92). This includes SSOs that was caused by severe natural conditions
or exceptional events unless the Permittee demonstrates through properly signed, contemporaneous
operating logs, or other relevant evidence that:
[a.] The SSO was caused by severe natural conditions; there were no feasible alternatives to the SSO, such as the use of auxiliary treatment facilities, retention of
untreated wastewater, reduction of inflow and infiltration, use of adequate backup equipment, or an increase in the capacity of the system. This provision is not
satisfied if, in the exercise of reasonable engineering judgment, the Permittee should have installed auxiliary or additional collections system components, wastewater
retention or treatment facilities, adequate back-up equipment or should have reduced inflow and infiltration; or
[b.] The $SO was exceptional, unintentional, temporary, and caused by factors beyond the reasonable control of the Permittee; the SSO could not have been prevented
by the exercise of reasonable control, such as proper management, operation, and maintenance; adequate treatment or collection facilities or components (e.g.,
adequately enlarging treatment of collection facilities to accommodate growth or adequately controlling and preventing infiltration and inflow); preventative
maintenance; or installation of adequate back-up equipment;”
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Incident Number # 2022000292 – 06/25/2022 - 12408 Village Pines Ln, Raleigh NC
This spill was neither willful nor intentional. It resulted from a grease build-up, restricting the sewer flow
within a section of a 12-inch ductile iron pipe gravity sewer main. This build-up led to a sewer spill of
approximately 34,800 gallons of untreated wastewater in which roughly 31,400 gallons remained within the
natural topography and/or were absorbed by the surrounding soil. A further site assessment estimated that
roughly 3,400 gallons may have reached an unnamed tributary that discharges into surface waters of the Neuse
River (see exhibit 1 – Area of Operation). However, visual observation did not identify wastewater debris near
the tributary’s discharge into the Neuse River.
Note
The NOV/NOI letter erroneously shows that 31,400 gallons reached surface water instead of 3,400.
Exhibit 1 – Area of Operation
On 06/25/2022, at approximately 8:49 AM, Raleigh Water staff responded to a sanitary sewer overflow
emanating from a sanitary sewer manhole (affected asset1 SMH123111) located near 12408 Village Pines Ln,
Raleigh NC. The responding staff took all reasonable steps to stop and mitigate the impact of the discharge,
gaining control of the spill event by 11:43 AM on the same day. Crews utilized hydraulic jetting to remove the
source of the blockage within the affecting asset2, thus restoring sewer flow.
The natural topography of the surrounding land, southwest of the affected asset, served to partially contain
approximately 31,400 gallons of untreated wastewater. The ground surrounding the affected manhole absorbed
a vast portion of untreated water before it reached surface waters of the Neuse River. See Exhibit 2 – Natural
containment. This spill was naturally and partially contained without a significant environmental impact on the
adjacent area and its natural resources. Visual inspection of the affected area and downstream waters
confirmed no fish kill or unnecessary vegetative damage.
1 Affected Asset: Structure within the collection system that allowed the release of untreated wastewater into the environment, typically a sewer manhole.
2. Affecting Asset: Structure within the collection system that housed a blockage that resulted in an SSO, typically a sewer gravity main.
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Exhibit 2 – Natural Containment
During the restoration phase of the operation, crews mechanically removed sewer-contaminated soil and
utilized over 3,000 gallons of potable water to flush the affected area and remove sewer traces from the
surrounding area and downstream conveyance. The area around the manhole was cleared of debris, treated
with an application of lime, and restored with grass seed and straw. See Exhibit 3 – Site Restoration.
Exhibit 3 – Site Restoration
The cost associated with the mitigation of this event amounted to $2,924.07. The approximate cost to the Utility
to have treated 34,800 gallons of wastewater would have been approximately $52.20. The City saved no money
from this spill. Its costs for cleanup exceeded the cost of treating the volume of sewage had no spill occurred.
Furthermore, the City still had to pay the cost to treat the greater volume of sewage created by the spill.
This section of the collection system is located downstream of a residential area. It provides sewer collection
services to over 200 residences upstream of the spill event (see Exhibit 4- Zone of Influence3). Within the last ten
years, this specific portion of the collection system has not experienced a grease-related SSO event. This area
has been placed on routine maintenance.
3. Zone of Influence: Area upstream from an SSO that contains homes or businesses whose discharge of wastewater may have contributed to the creation of a
system blockage. Identifying this area is critical to analyzing potential sources of illicit discharges such as grease or rags that generate blockages, as well as
determining where educational materials can be distributed post-incident to educate residents regarding the proper use of the collection system.
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Exhibit 4- Zone of Influence
Outreach information literature was requested to be sent to the immediate-affected area. The requested
outreach literature explains the need for customers to use the sanitary sewer collection system properly. It also
serves as an opportunity for citizens to partner with Public Utilities to protect the City's water quality and the
sewer collection infrastructure.
A press release notification was requested to be published in the Raleigh News & Observer as required by NCGS
Article 21, Chapter 143.215.1C. See Exhibit 5 – Press release. Outreach information literature was requested to
be sent to the immediate-affected area. The requested outreach literature explains the need for customers to
use the sanitary sewer collection system properly. It also serves as an opportunity for citizens to partner with
Public Utilities to protect the City's water quality and the sewer collection infrastructure.
See Exhibit 5 – Press Release
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Before this event, maintenance records show that sections within the zone of influence of this collection system
were assessed within the last 10 years as follows:
Flushing activities CCTV Activities
Easement
Maintenance
Activities
Inspections Activities
5/31/2017
10/19/2017
1/26/2018
1/30/2018
1/31/2018
2/2/2018
7/22/2021
10/5/2017
10/16/2017
10/27/2017
10/30/2017
10/31/2017
11/1/2017
11/2/2017
11/3/2017
11/14/2017
6/27/2022 There have been 1,409 inspections completed
from 2017-08-30 to 2022-08-01
1. Easement Inspections – 96
2. FOG GGI Inspections – 229
3. Manhole Inspections – 196
4. Sewer High Priority Inspections – 842
There have been no additional issues associated with this section of the collection system since the last sewer
event. This site continues to remain an active maintenance spot pending completion of further sewer main
cleaning and CCTV assessment.
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Incident Number # 202200994 – 6/26/2022 – 6600 Glenwood Ave., Raleigh NC
This spill was neither willful nor intentional. It resulted from a grease build-up, restricting the sewer flow
within a section of 8-inch polyvinyl chloride (PVC) pipe gravity sewer main. This build-up led to a sewer spill of
approximately 1,905 gallons of untreated wastewater remaining on the ground and not reaching the surface
waters of the state. (See Exhibit 1 – Area of Operation)
Exhibit 1 – Area of Operation
On 6/26/22, at approximately 3:38 PM, Raleigh Water staff responded to a sanitary sewer overflow emanating
from a sanitary sewer manhole (SMH148641) located near 6600 Glenwood Ave., Raleigh NC. The responding
staff took all reasonable steps to stop and mitigate the impact of the discharge, gaining control of the spill event
by 5:45 PM on the same day. Crews utilized hydraulic jetting to remove the source of the blockage within the
affecting asset, thus restoring sewer flow.
Containment and collection of this spill event consisted of employing a vacuum truck to recover stagnant
wastewater that remained in the natural topography. This approach was intended to contain wastewater flow
and minimize the environmental impact on the surrounding land. Responding crews employed pumps at the
temporary containment site to recover flushed wastewater and any evidence of sewer completing the operation
by re-introducing the wastewater to the collection system. This spill was contained without a significant
environmental impact on the adjacent area and its natural resources. Visual inspection of the affected area and
downstream waters confirmed no fish kill or unnecessary vegetative damage.
During the restoration phase of the operation, crews utilized ample potable water to flush the affected area and
remove sewer traces from the surrounding area. The area around the manhole and containment area was
cleared of debris, treated with an application of lime, and restored with grass seed and straw.
A follow-up CCTV assessment was conducted on 6/28/2022 to identify the root cause of the SSO. The CCTV
assessment identified the root cause to be a large offset joint within Sewer gravity main 105239 located 237.4’
downstream from Sewer manhole 120710. See Exhibit 2 – Offset joint. The assessment recommended a point
repair (Work Order #1448802) to remove the offset joint and conduct a follow-up camera inspection to view the
rest of the pipe. These assets have been placed on the Division’s Hotspot list for increased maintenance.
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Exhibit 2 – Offset joint
The cost associated with the mitigation of this event amounted to $1,992.67. The approximate cost to the Utility
to have treated 1,905 gallons of wastewater would have been approximately $2.85. The City saved no money
from this spill. Its costs for cleanup exceeded the cost of treating the volume of sewage had no spill occurred.
Furthermore, the City still had to pay the cost to treat the greater volume of sewage created by the spill.
This section of the collection system is located downstream of a commercial area. It provides sewer collection
services to several food service establishments (see Exhibit 4- Zone of Influence). A Fats, Oils, and Grease (FOG)
assessment conducted a compliance follow-up at fourteen (14) food service establishments upstream from the
affecting asset located in the Townridge Shopping Center. Two of these establishments are currently out of
business, yielding twelve (12) total inspections to be completed. This specific portion of the collection system
has not experienced a grease-related SSO event within the last ten years. This area will be placed under routine
maintenance upon completion of the point repair.
Exhibit 4- Zone of Influence
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A press release notification was requested to be published in the Raleigh News & Observer as required by NCGS
Article 21, Chapter 143.215.1C. See Exhibit 5 – Press release. Outreach information literature was requested to
be sent to the immediate-affected area. The requested outreach literature explains the need for customers to
use the sanitary sewer collection system properly. It also serves as an opportunity for citizens to partner with
Public Utilities to protect the City's water quality and the sewer collection infrastructure.
See Exhibit 5 – Press Release
Before this event, maintenance records show that sections within the zone of influence of this collection system
were assessed within the last 10 years as follows:
Flushing activities CCTV
Activities
Inspections Activities
2/14/2018
9/20/2018
9/25/2018
10/29/2018
9/25/2018
5/12/2021
9/28/2020
4/4/2022
3/16/2022
7/21/2022
6/28/2022 There have been 1,409 inspections completed
from 11/27/2017 to 8/8/2022
1. FOG GGI Inspections – 99
2. Manhole Inspections – 21
3. Sewer High Priority Inspections – 10
There have been no additional issues associated with this section of the collection system since the last sewer
event. This site continues to remain an active maintenance spot pending completion of further sewer main
repair and subsequent sewer cleaning and CCTV assessment.
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Incident Number # 202200996 – 6/27/2022 – 2214-2598 Garner Station Blvd., Raleigh, NC
This spill was neither willful nor intentional; it resulted from a large quantity of debris that entered the
wet well during the night of 6/26/2022. This accumulation affected the pump cycle and wastewater flow
capacity.
On the morning of 6/27/2022, a pump station mechanic arrived on site for a routine station check and found the
wet well overflowing. Immediate was taken to mitigate the scene. Upon initial assessment, it was determined
that although the debris accumulation allowed the pumps to cycle on as normal, once the wet well level began
to drop the debris became entangled in the alarm floats and affected the wet well MultiTrode level controller.
As the well began to fill again, the MultiTrode level controller was able to cycle the pumps ON but had reached
the point it wasn't able to cycle the pumps OFF. The alarm floats were found entangled and were unable to send
signals via SCADA. As the pumps continued to run, the debris was being sucked into each pump until pump #1
had an amperage overload and the resulting fault tripped the main breaker. Pump #2 continued to take in debris
until it had been damaged to the point it was unable to move water. Both pumps ultimately needed to be
replaced. Subsequently, bypass pumping was immediately established to control flow coming into the wet well.
This event resulted in the approximate loss of 12,300 gallons of which roughly 3,500 gallons remained within the
natural topography not reaching surface waters of the state. This event affected an unnamed tributary of the
Upper Swift Basin. See Exhibit 1 - Area of Operation.
Exhibit-1 – Area of Operation
Containment and collection of this spill event consisted of placing a temporary containment dam downstream of
the station This emplacement contained filtering media to stop wastewater debris from flowing downstream. A
water pump was placed in the containment dam to collect and transfer the wastewater from the stream and
reintroduce it into the collection system. Vacuum trucks were used to remove wastewater from the pump
station returning the wastewater elsewhere into the collection system. See Exhibit 2 - Containment and
Collection Efforts.
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Exhibit 2 - Containment and Collection Efforts.
Restoration of this spill event consisted of washing the land surrounding the station. Sewer debris and solids
were collected and disposed of accordingly. Crews utilized ample potable water to flush the affected area. This
spill was contained without a significant environmental impact on the adjacent area and its natural resources.
Visual inspection of the affected area and downstream waters confirmed that no fish kill or unnecessary
vegetative damage occurred. See exhibit 3 – Restoration Efforts.
Exhibit 3 – Restoration Efforts
The cost associated with the mitigation of this event (including replacement of two pumps and labor) amounted
to over $80,490.30. The approximate cost to the Utility to have treated 12,300 gallons of wastewater would
have been approximately $18.45. The City saved no money from this spill. Its costs for cleanup exceeded the
cost of treating the volume of sewage had no spill occurred. Furthermore, the City still had to pay the cost to
treat the greater volume of sewage created by the spill.
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This pump station services a vast residential and commercial area within the Garner Service area. There has
been no history of asset failures associated with this Sewer Network Structure. Prior to this event, maintenance
records show that this station was last serviced on 2022-06-21 at 08:26 AM, with no issues to report. The
attached list contains inspections and assessment activities for 2022.
Work Order
Reference Activity Date and time performed
815436 PU Submersible PS Check 2022-01-03 09:40 AM
817101 PU Submersible PS Check 2022-01-10 06:35 AM
819661 PU Submersible PS Check 2022-01-19 07:41 AM
821827 PU Submersible PS Check 2022-01-24 10:30 AM
823325 PU Submersible PS Check 2022-01-31 07:08 AM
825440 PU Submersible PS Check 2022-02-07 07:12 AM
829293 PU Submersible PS Check 2022-02-14 07:48 AM
833962 PU Submersible PS Check 2022-02-21 07:12 AM
836887 PU Submersible PS Check 2022-02-28 07:24 AM
839619 PU Submersible PS Check 2022-03-07 08:12 AM
841994 PU Submersible PS Check 2022-03-14 07:22 AM
842776 PU Submersible PS Check 2022-03-21 10:53 AM
845206 PU Submersible PS Check 2022-03-28 08:17 AM
846111 PU Submersible PS Check 2022-04-04 11:05 AM
847329 PU Submersible PS Check 2022-04-11 07:42 AM
850571 PU Submersible PS Check 2022-04-18 07:26 AM
851830 PU Submersible PS Check 2022-04-25 07:09 AM
852725 PU Submersible PS Check 2022-05-02 07:24 AM
855910 PU Submersible PS Check 2022-05-09 07:38 AM
857227 PU Submersible PS Check 2022-05-16 07:00 AM
862390 PU Submersible PS Check 2022-05-23 07:25 AM
864169 PU Submersible PS Check 2022-05-31 07:11 AM
866480 PU Submersible PS Check 2022-06-06 06:45 AM
868563 PU Submersible PS Check 2022-06-13 07:56 AM
871657 PU Submersible PS Check 2022-06-21 08:26 AM
There have been no additional issues associated with this section of the collection system since the last sewer
event. This site remains an active maintenance spot until all upgrades have been installed and tested for
efficiency. The station continues to be assessed to ensure no other malfunctions occur. A press release
notification associated with this event was requested to be published in the Raleigh News & Observer on June
28th, 2022 (see exhibit 3 – Press Release).
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Exhibit 3 - Press Release
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Summary
The Sewer Maintenance Division of Raleigh Water strives to develop initiatives that improve operational
reliability to meet customer expectations and meet or exceed the Water Quality Collection System permit
requirements. Our operations are focused on continual improvement, the prevention of pollution, and increased
environmental performance efficiency. This endeavor is significantly noted as the Division operates an ISO
Certified Environmental Management System governed by the 14001-2015 Standards. As part of these
initiatives, the Division operates a comprehensive reactive and preventative maintenance program whose goal is
to maintain over 2,566 miles of sanitary sewer pipe and minimize the accidental release of untreated
wastewater.
Since July 2022 (Fiscal Year 2023), the Utility has assessed approximately 26.24 [1] miles of gravity sewer mains
by flushing with hydraulic jetting, conducting CCTV assessments, and performing repair operations, easement
maintenance, and inspections. The fiscal year-to-date cost of these operations amounts to
$ 219,544.69 [2], approximately .016% of the Division's annual operating budget. The 49,005 gallons of untreated
wastewater spill identified in this letter cost the Utility approximately $85,407.04. to mitigate. The City's cost of
sewer treatment per gallon is $.0015 [3]. At this rate, it would have cost the City $73.50 to treat the entire
volume of sewer spilled. The City saved no money from these spills. The costs of mitigation well exceeded the
cost of treating the volume of sewage had no spill occurred. Furthermore, the City still had to pay the cost to
treat the greater sewage volume created by these spills. This fiscal comparison shows the City's commitment to
environmental protection, sparing no cost regardless of the spill event's severity and complexity. The City
continues to demonstrate due diligence in environmental performance by allocating the necessary resources to
a spill event irrespective of the associated cost. This effort is noted in the City's low SSO performance rate of
0.31 total SSO rate [4] per 100 miles of pipe, compared to the Southeastern Region of the US, of 7.0 spills per 100
miles of line. In the previous Fiscal year 22 total performance miles assessed were 417.34 Miles at a cost of
$ 2,829,598.09.
[1] 26.24 miles represents 0.1% of the sanitary sewer collection system
[2] Associated operational cost year to date for FY202 3
OPERATION LINEAR FEET Linear Miles COST
CCTV 53,395.92 10.11 $ 44,882.36
Repair 330 0.06 $ 118,761.24
Flushing 84,834.33 16.07 $ 55,901.09
Total - 138,560.25 Ft
26.24 MILES
Total cost of Business to Date
$ 219,544.69
[3] $.0015 is based on the annual water treatment operating cost compounded by the total treated effluent.
[4] The current SSO Rate for FY 23 is 0.31
Additionally, the City of Raleigh Assistant Public Utility Directors and Collections System staff have become
involved in challenging the nonwoven fabrics industry standards to better inform consumers of these products
and their detrimental effects on the collections systems. PUD staff has personally met with officers of INDA, the
leading association of the nonwoven fabrics industry based in Cary, NC, to communicate our concerns about
these fabrics, the current industry standards, and better education for the consumer. PUD has also joined forces
with other utilities nationwide through the National Association of Clean Waters Agencies (NACWA), the Water
Environment Foundation (WEF), and the American Public Works Association (APWA) to challenge INDA and
current industry standards, recognizing that they do not support compatibility in sanitary sewer collections
systems nationally. These agencies work collectively to challenge the testing protocols, assessment guidelines,
and consumer education and labeling of these non-dispersible.
Raleigh Water has an aggressive educational outreach initiative to address illicit discharges such as wipes, fats,
oil, and grease to commercial and residential users. Raleigh Water has developed a complimentary property
managers resource kit that provides best practice resources for establishing a property-specific awareness
program. Each kit contains brochures and complimentary gadgets to help residents manage grease and fat
collection and disposal. The resource kit also features a multimedia flash drive with videos and reproducible
educational material that property managers can use to educate tenants to reduce the risk of sewer backups
caused by the introduction of solids through their residential piping. Each kit costs Raleigh water approximately
$85.00 to produce and is provided free of charge to the property management. Raleigh Water is continuously
developing initiatives to increase residential and commercial customer partnerships to address grease
accumulation and prevent illicit discharges. The educational material and videos can be accessed through social
media and the Raleigh Water website https://raleighnc.gov/sewer-maintenance
The City continues its monetary reward program or bounty program, which pays out fifty ($50) dollars to any
citizen that observes and reports an SSO or conditions that may cause a spill event. This program has been
advertised via printed material, a television advertisement campaign, and graphic design "wraps" on Sewer
Maintenance vehicles. These graphics on our vehicles function as mobile billboards spreading our message of
prevention and offering contact information throughout the service area each day. This program was developed
hoping that citizens and customers would become more aware of the signs of an emerging system problem
causing the SSO occurrence and become proactive in helping the City prevent these occurrences. Additionally,
all customers are notified via their water and sewer utility bills not to discharge improper materials into the
sanitary sewer mains. The City also circulates information regarding the discharge of grease into the sewer
system and the effects of such deposits. Whenever possible, and upon investigating the root cause of a spill
event, PUD Code Enforcement officers develop and send registered informational letters about the spill event to
the customer base serviced by the line where the SSO has occurred. This is done to educate our customers on
the proper use of sanitary sewers to prevent the disposal of non-flushable items and items harmful to the
continuous operation of the collections system.
On behalf of the City of Raleigh, | am requesting that the NOV-2022-NOI-00199 issued for the month of June
2022 be fairly reviewed, considering the steps the Department has taken to protect the environment and meet
or exceed the requirements of the Collections System Permit. If additional information is required, please
contact Matthew Vessie, Sewer Maintenance Superintendent (919) 996-2312, or Carlos M. Perez, ORC
Assistance Superintendent 919-996-5929.
Sincerely,
Carlos M Perez, ORC
Assistance Superintendent, Sewer Maintenance Division
City of Raleigh, Public Utilities Department
P.O. Box 590
Raleigh, NC 27602-0590
919-996-5929 office
919-278-6020 cell
Carlos.perezcamacho @raleighnc.Gov
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