HomeMy WebLinkAboutWQCS00002_NOV-2023-DV-0270_GC Rvcd_20230810\ 44110 0
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Raleigh Water
August 2"d, 2023
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-2023-DV-0270
Sanitary Sewer Overflows —June 2023
Permit No. WQCS00002
Dear Mr. Vinson:
Please allow this letter to serve as a response to the Notice of Violation document (NOV-2023-DV-0270)
received on July 17th, 2023. This document contains the narrative regarding pending Notice of Violation action of
(1) Sanitary Sewer Overflow (SSO) event, reported on the month of June 2023 within the City of Raleigh
Collections System ill• This document also provides exhibits as proof of our efforts to mitigate 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-NOI) 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 SSO 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;"
Incident Number # 202300929 6/13/2023 —4744 Archean Way, Raleigh, NC, 27616
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 6,624 gallons of untreated wastewater in which approximately 3,000 gallons reached an
unnamed tributary within the Perry Basin. (See Exhibit 1— Area of Operation)
On 06/13/2023, at approximately 9:36 AM, Raleigh Water staff responded to a sanitary sewer overflow
emanating from a sanitary sewer manhole (SMH115556) located near 4744 Archean Way, 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 12:12 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 temporary containment site at
downstream of the affected asset. This approach was intended to contain wastewater flow and minimize the
environmental impact on the surrounding land. Crews were able to successfully contain approximately 3,624
gallons of untreated wastewater before it reached surface waters of state preventing further environmental
pollution. 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 6/26/2023 to identify the root cause of the SSO. Additional
flushing of sewer gravity mains upstream and downstream of the affected asset was completed on 6/15/2023.
This hydraulic flushing did not identify any major issues with the main.
The cost associated with the mitigation of this event amounted to $7,845.71. The approximate cost to the Utility
to have treated 6,624 gallons of wastewater would have been approximately $9.93. 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 a private multi -dwelling property upstream of the spill event (see Exhibit 2- Zone of Influence). This
specific portion of the collection system has not experienced a grease -related SSO event. This area has been
placed under routine maintenance for continued assessment.
Exhibit 2- Zone of Influence
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 3 — 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.
Exhibit 3—Press Release
Raleigh Water Responds to a Sanitary Sewer Overflow
Reminder: Keep All Grease Out of the System
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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
6/15/2023 6/26/2023
7/25/2023
Repair Activities Inspections Activities
8/2/2017 Since 2018-01-08
there has been:
69 - High Priority Inspections
completed in the area
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 the completion of further sewer main
cleaning and CCTV assessment.
L!
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 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 preventive maintenance program to maintain over 2,600 miles
of sanitary sewer pipe and minimize the accidental release of untreated wastewater.
Since July 2022 (Fiscal Year 2023), the Utility has maintained approximately 936.95 [11 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 $
2,054,254.45 [2], approximately 14% of the Division's annual operating budget. The 6,624 gallons of untreated
wastewater, identified as notice of violations in this letter, cost the Utility approximately $7,845.71 to mitigate.
The City's cost of sewer treatment per gallon is $.0015 [3). At this rate, treating the untreated wastewater spilled
would cost the City $9.93. 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 for treating 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
incident's severity and complexity. The City continues demonstrating due diligence in environmental
performance by allocating resources to a spill incident regardless of the associated cost. This effort is noted in
the City's SSO performance rate of 1.15 total SSO rate [4) per 100 miles of pipe, compared to the Southeastern
Region of the U.S., of 7.0 spills per 100 miles of line.
(1) 936.95 miles represents approximately 36%of the entire sanitary sewer collection system
[21 Associated operational cost year to date for FY2023
OPERATION
LINEAR FEET
Linear Miles
COST
CCTV
413,21L20
78.25
366,545.26
Repair
1,310
0.25
932,093.69
Flushing
1,836,732.38
347.8
624,65L96
Easement
459,360.00
87
130,963.54
Easement Inspections
2,236,890.12
426.65
N/A
The total cost of Business to
Total- 4,947,503.70 Ft/ 939.95 MILES
Date is $2,054,254.45
[31 F.Y. 2023 annual Divisional budget - $14,657,701
141 $.0015 Is based on the annual water treatment operating cost compounded by the total treated effluent.
[51 The current SSO Rate for F.Y. 23 Is 1.15
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 continuously
develops initiatives to increase residential and commercial customer partnerships to address grease
accumulation and prevent illicit incident 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 or bounty program, which pays out fifty ($50) to any citizen who
observes and reports an SSO or conditions that may cause a spill incident. 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 daily. 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 materials that could block the flow of the sanitary
sewer mains. The City also circulates information regarding grease discharge into the sewer system and the
effects of such deposits. Whenever possible, and upon investigating the root cause of a spill incident, PUD Code
Enforcement officers develop and send registered informational letters about the spill incident 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, I am requesting that the NOV-2023-DV-0270 issued for the month of June 2023
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, don't hesitate
to contact Matthew Vessie, Sewer Maintenance Superintendent, at (919) 996-2312 or Carlos M. Perez, ORC,
Assistance Superintendent, at 919-996-5929.
Si cerely,a��y� � \
Carloo MV\ Perez, ORC
A stance 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 @ raleishnc.Gov