HomeMy WebLinkAbout04 - Illicit Discharge Detection and Elimination Plan
Illicit Discharge Detection and Elimination Plan
City of Raleigh Stormwater Management Divison
January 2022
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Table of Contents
List of Acronyms ...................................................................................................................... iii
List of Definitions ..................................................................................................................... iv
1 Introduction ................................................................................................................... 6
1.1 Purpose of Document .......................................................................................... 6
1.2 Regulatory Context .............................................................................................. 6
1.2.1 NPDES MS4 Permit ................................................................................. 6
1.2.2 City Illicit Discharge Ordinance ................................................................. 7
1.2.3 Allowable Non-Stormwater Discharges .................................................... 7
1.3 Related Regulatory Programs .............................................................................. 8
1.3.1 Nutrient Sensitive Waters ......................................................................... 8
1.3.2 Total Maximum Daily Loads ...................................................................... 9
2 Organization, Roles, and Responsibilities ................................................................... 9
2.1 City Organization ................................................................................................. 9
2.2 Roles and Responsibilities ................................................................................. 10
2.2.1 Stormwater Management Division .......................................................... 10
2.2.2 Other City Divisions and Departments .................................................... 10
2.2.3 Non-City Entities ..................................................................................... 12
3 Tracing Flow Paths of Discharged Substances......................................................... 14
3.1 Available Information and Tools ......................................................................... 14
3.2 MS4 Base Map .................................................................................................. 14
3.3 Stormwater Outfalls ........................................................................................... 15
3.4 Receiving Waters ............................................................................................... 15
4 Illicit Discharge and Illicit Connection Response and Documentation.................... 15
4.1 Intake of Notifications ......................................................................................... 15
4.2 Response and Investigation ............................................................................... 16
4.2.1 Enforcement Actions .............................................................................. 16
4.3 Safety ................................................................................................................ 16
4.4 Documentation and Closeout ............................................................................. 17
4.5 Reporting Requirements .................................................................................... 17
5 Dry Weather Flow Inspection ...................................................................................... 21
5.1 Inspection Protocols ........................................................................................... 21
5.2 Response and Investigation ............................................................................... 21
5.3 Documentation ................................................................................................... 21
6 Training, Education, and Outreach ............................................................................ 21
6.1 Stormwater Management Staff ........................................................................... 21
6.2 Other City Staff .................................................................................................. 21
6.3 General Public ................................................................................................... 22
7 Program Evaluation and Reporting ............................................................................ 22
7.1 Effectiveness Evaluation .................................................................................... 22
7.2 Annual Reporting ............................................................................................... 22
8 Revision History .......................................................................................................... 23
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9 References ................................................................................................................... 24
Figures
Figure 1 City of Raleigh Organization ........................................................................................ 10
Figure 2 Stormwater Management Division Notification and Enforcement Decision Tree .......... 20
Tables
Table 1 Summary of EPA-Approved TMDLs or Nutrient Management Strategies ........................ 8
Table 2 Other City Departments Involved in IDDE Response .................................................... 11
Table 3 Other Responsible Entities ........................................................................................... 13
Table 4 Reporting Thresholds ................................................................................................... 18
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List of Acronyms
BMP Best Management Practice
City City of Raleigh
EPA U.S. Environmental Protection Agency
ETJ
GIS
Extra Territorial Jurisdiction
Geographic Information System
HUC Hydrologic Unit Code
IDDE Illicit Discharge and Detection and Elimination
MS4 Municipal Separate Storm Sewer System
NCDEQ North Carolina Department of Environmental Quality
NCDOT North Carolina Department of Transportation
NCDWR North Carolina Department of Water Resources
NCSU North Carolina State University
NOV Notice of Violation
NPDES National Pollutant Discharge Elimination System
NSW Nutrient Sensitive Waters
PPE personal protection equipment
PPGH Pollution Prevention and Good Housekeeping
RFD Raleigh Fire Department
ROW Right-of-Way
SCM stormwater control measure
SOP standard operating procedure
SPPP
SWMP
Site Pollution Prevention Plan
Stormwater Management Plan
SWPPP Stormwater Pollution Prevention Plan
SWS Solid Waste Services
UDO Unified Development Ordinance
USGS United States Geological Survey
TMDL Total Maximum Daily Load
WLA Waste Load Allocation
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List of Definitions
Dry Weather Flow: Any observable flow in a stormwater drainage pipe that may occur 72 hours
or greater after a rain event of less than 0.10 inch. Dry weather flows can include groundwater,
discharge from sump pumps or French drains, air conditioning condensate, car wash runoff, or
illicit connections to the stormwater conveyance system.
Illicit Connection: Any unlawful connection which allows the discharge of non-stormwater to the
stormwater conveyance system or waters of the State in violation of the Illicit Discharge Ordinance
as defined in the City of Raleigh Illicit Discharge Ordinance.
Illicit Discharge: Any unlawful disposal, placement, emptying, dumping, spillage, leakage,
pumping, pouring, emission, or other discharge of any substance other than stormwater into a
stormwater conveyance, the waters of the State, or upon the land in such proximity to the same,
such that the substance is likely to reach a stormwater conveyance or the waters of the State, as
defined in the City of Raleigh Illicit Discharge Ordinance.
Illicit Discharge Ordinance: City of Raleigh Code of Ordinances, Chapter 5 Offenses Against
the Environment, Section 13-5001, Ordinance No. 1995-573, §2, 3-7-95.
Major Outfall: Major municipal separate storm sewer outfall (or ``Major MS4 Outfall''), as defined
by the City of Raleigh NPDES Permit NCS000245 and the NCDEQ, means a municipal separate
storm sewer outfall that discharges from a single pipe with an inside diameter of 36 inches or
more or its equivalent (discharge from a single conveyance other than circular pipe which is
associated with a drainage area of more than 50 acres); or for municipal separate storm sewers
that receive storm water from lands zoned for industrial activity (based on comprehensive zoning
plans or the equivalent), an outfall that discharges from a single pipe with an inside diameter of
12 inches or more or from its equivalent (discharge from other than a circular pipe associated with
a drainage area of 2 acres or more).
Municipal Separate Storm Sewer System (MS4): as defined by the Illicit Discharge Ordinance,
is a stormwater conveyance or unified stormwater conveyance system (including without
limitation: roads with drainage systems, municipal streets, catch basins, stormwater detention
facilities, curbs, gutters, ditches, natural or man-made channels, or storm drains), that:
(1) Is located within the corporate limits of Raleigh, North Carolina; and
(2) Is owned or operated by the State, County, the City, or other public body; and
(3) Discharges to waters of the State, excluding publicly owned treatment works, and
lawful connections thereto, which in turn discharge into the waters of the State.
Receiving Waters: As defined by the State of North Carolina General Statutes (G.S.) 143-212(6),
are surface waters within or flowing through the boundaries of the State of North Carolina
including the following: any intermittent or perennial stream, river, creek, brook, swamp, lake,
sound, tidal estuary, bay, reservoir, wetland, or any other surface water or any portion thereof that
is identified as “Receiving Waters” in the City’s Stormwater Management Plan.
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Responsible Party: Party determined as financially culpable, the cause, and/or the source of an
illicit discharge or an illicit connection.
Stormwater Control Measure (SCM): As defined in 15A NCAC 02H .1002, also known as Best
Management Practice (BMP), a permanent structural device that is designed, constructed, and
maintained to remove pollutants from stormwater runoff by promoting settling or filtration, or mimic
the natural hydrologic cycle by promoting infiltration, evapotranspiration, post-filtration discharge,
reuse of stormwater, or a combination thereof.
Stormwater Conveyance (System): Any feature or system of features, natural or man-made,
that collects and transports stormwater, including but not limited to, roads with drainage systems,
streets, catch basins, curbs, gutters, ditches, man-made and natural channels, pipes, culverts,
and storm drains, and any other natural or man-made feature or structure designed or used for
collecting or conveying stormwater, as defined in the City of Raleigh Illicit Discharge Ordinance.
Waters of the State: Surface waters within or flowing through the boundaries of the State
including the following: any intermittent or perennial stream, river, creek, brook, swamp, lake,
sound, tidal estuary, bay, reservoir, wetland, or any other surface water or any portion thereof that
is mapped as solid or dashed blue lines on United States Department of the Interior Geological
Survey 7.5 minute series topographic maps. Treatment systems, consisting of man-made bodies
of water, which were not originally created in waters of the State and which are not the result of
impoundment of waters of the State, are not waters of the State, as defined in the City of Raleigh
Illicit Discharge Ordinance.
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1 Introduction
The City of Raleigh (City) is identified as the Permittee in National Pollutant Discharge Elimination System
(NPDES) Municipal Separate Storm Sewer System (MS4) Permit Number NCS000245. The current
iteration of this permit became effective October 10, 2018 and extends through October 9, 2023. This
permit authorizes the City to discharge stormwater from the City’s MS4 to receiving waters of the State
within the Neuse River Basin.
The City’s Stormwater Management Plan (SWMP) establishes the methods by which the City implements
the permit requirements for complying with six minimum control measures for protecting receiving stream
water quality and controlling the discharge of pollutants associated with stormwater runoff and illicit
discharges to the extent allowable under State and local law.
1.1 Purpose of Document
This document describes the City’s program plan to implement an Illicit Discharge and Detection and
Elimination (IDDE) program that systematically finds and eliminates sources of non-stormwater
discharges to its MS4 and implement procedures for preventing such discharges. In conjunction with this
document, the following Standard Operating Procedures (SOPs) support the City’s IDDE program:
• SW-100 Internal Illicit Discharge Detection and Elimination SOP, May 17, 2021
• SW-101 Managing Spills which Threaten to Enter the Stormwater Conveyance System,
December 1, 2020
• SW-102 Interdepartmental SOP for Managing Spills, December 1, 2020
• SW-103 Outfall Inspection for Illicit Discharge Detection SOP, January 5, 2022
1.2 Regulatory Context
The following NPDES permit, the Raleigh City Code, and specific State of North Carolina programs
provide the regulatory context for the IDDE program plan, prioritization, and implementation
requirements.
1.2.1 NPDES MS4 Permit
The City’s NPDES MS4 Permit, Part II, Section D (“Illicit Discharge Detection and Elimination (IDDE)),
requires the City to:
• 1(a) Detect and eliminate illicit connections and discharges, including preventable spills and illegal
dumping to the Permittee’s MS4;
• 1(b) Implement appropriate enforcement procedures and actions;
• 1(c) Maintain a map showing the permittee’s major outfalls to state waters receiving discharges;
and
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• 1(d) Inform employees, businesses, and the general public of hazards associated with illegal
discharges and improper disposal of waste.
1.2.2 City Illicit Discharge Ordinance
The Stormwater Management Division is authorized to implement its IDDE Program through the City of
Raleigh City Code, Chapter 5 Offenses Against the Environment, Section 13-5001, Ordinance No. 1995-
573, §2, 3-7-95. This chapter is known and may be cited as the City of Raleigh’s “Illicit Discharge
Ordinance.” The Illicit Discharge Ordinance gives the City legal authority to protect public health, safety,
and welfare by controlling the discharge or pollutants into the stormwater conveyance system, and to
also satisfy the requirements imposed upon the City under its National Pollutant Discharge Elimination
System (NPDES) Municipal Separate Storm Sewer System (MS4) discharge permit issued by the
NCDEQ. It also establishes administrative and enforcement procedures through which the above
purposes can be fulfilled. The Illicit Discharge Ordinance can be accessed via the City’s Municode
website: https://library.municode.com/nc/raleigh/codes/code_of_ordinances.
1.2.3 Allowable Non-Stormwater Discharges
The City of Raleigh’s Illicit Discharge Ordinance allows non-stormwater discharges from the following
activities if they do not significantly impact water quality:
(1) Declorinated swimming pool discharges;
(2) Discharges from potable water sources;
(3) Condensate from residential or commercial air conditioning;
(4) Residential and non-profit vehicle washing;
(5) Water line flushing;
(6) Discharges associated with emergency removal and treatment activities, for hazardous
materials, authorized by the federal, State, or local government on-scene coordinator;
(7) Uncontaminated ground water [including the collection or pumping of springs, wells, or rising
ground water and ground water generated by well construction or other construction activities];
(8) Collected infiltrated stormwater from foundation or footing drains;
(9) Collected ground water and infiltrated stormwater from basement or crawl space pumps;
(10) Irrigation water (does not include reclaimed water as described in 15A NCAC 2H .0200);
(11) Street wash water;
(12) Flows from emergency fire fighting;
(13) Discharges from the pumping or draining of natural watercourses or waterbodies;
(14) Flushing and cleaning of stormwater conveyances with unmodified potable water;
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(15) Flows from riparian habitats and wetlands;
(16) Diverted stream flows;
(17) Placing leaves at the curbside for the City's residential seasonal leaf collection program;
(18) Wash water from the cleaning of the exterior of buildings, including gutters, provided that the
discharge does not pose an environmental or health threat; and
(19) Other non-stormwater discharges for which a valid NPDES discharge permit has been
approved and issued by NCDENR, provided that any such discharges to the municipal separate
storm sewer system shall be authorized by the City.
1.3 Related Regulatory Programs
The following restoration strategies have been established in response to assessed impairments of
Waters of the State and will be considered in IDDE planning, response, and outreach programs. Table 1
describes a brief overview of these EPA-approved Total Maximum Daily Loads (TMDL) and nutrient
management strategies.
Table 1 Summary of EPA-Approved TMDLs or Nutrient Management Strategies
Water Body
Name
TMDL
Pollutant(s) of
Concern
Assigned Numeric
MS4 WLA (Y/N) Water Quality Recovery Program (Y/N)
Pigeon House
Branch
Copper and
Fecal Coliform
No No
Perry Creek Benthos No No
Falls Lake Nitrogen and
Phosphorus
No City participating in 4B nutrient
management strategy
Neuse River
Estuary
Nitrogen No City is implementing the State Nutrient
Sensitive Waters Management Strategy
1.3.1 Nutrient Sensitive Waters
All waters of the Neuse River Basin are supplementally classified as Nutrient Sensitive Waters (NSW)
pursuant to 15A North Carolina Administration Code (NCAC) 02B .0223 due to excess nutrient inputs.
The following strategies have been established in response to this classification.
Falls Nutrient Strategy
The Falls of Neuse reservoir, and all waters draining to it, have been supplementally classified as Nutrient
Sensitive Waters (NSW) pursuant to 15A NCAC 02B .0101(e)(3) and 15A NCAC 02B .0223. The Falls
Nutrient Strategy classifies the waterbody’s uses and maintains and enhances protections currently
implemented by the local governments, including the City of Raleigh.
Neuse Nutrient Strategy
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The Neuse River estuary, ending in the Pamlico Sound, and all water draining to it, have been
supplementally classified as NSW pursuant to 15A NCAC 02B .0223. The Rule and Rules 15A NCAC
02B .0711 and .0715 were established to attain designated uses of the Neuse River estuary with respect
to meeting nutrient-related water quality standards. The Neuse nutrient strategy rules require controls to
reduce nitrogen loads from significant sources of this nutrient throughout the Neuse Basin. These rules
do not address sources for which there is insufficient scientific knowledge to base regulation.
Additional information is provided in Sections 2.5 and 8 of the Stormwater Management Plan (SWMP).
1.3.2 Total Maximum Daily Loads
The EPA has identified two Total Maximum Daily Loads (TMDLs) in the Upper Neuse River Basin within
the City’s MS4 as part of the assessment performed and presented in the Section 303(d) list of impaired
waters, according to their priority ranking. These TMDLs are briefly described below:
Pigeon House Branch
On the draft 2002 North Carolina Integrated Report, the NCDEQ identified a 2.9-mile segment (27-33-
18) of Pigeon House Branch in the Neuse Basin as impaired by fecal coliform bacteria and copper. The
impaired segment extends from the stream’s source to its confluence with Crabtree Creek, and was
monitored at the station along Dortch Street near Wade Ave.
Perry Creek
The NCDEQ established a TMDL to address impaired biological integrity in the Perry Creek Watershed
on May 13, 2010, with the goal to improve the watershed ecosystem through stormwater BMPs and
restore the beneficial uses of the waterbody. The TMDL applies to the entire Perry Creek watershed that
comprises a drainage area of 11 square miles. Based on a weight of evidence analysis for the Perry
Creek watershed, the two most important factors contributing to impairment are scour and habitat
degradation.
Additional information is provided in Section 2.5 SWMP and the EPA-approved TMDL(s).
2 Organization, Roles, and Responsibilities
2.1 City Organization
The organizational structure of the City includes a governing body, City Manager, and multiple City
departments, all of which are supported by the City Attorney’s Office, organized as shown in Figure 1.
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Figure 1 City of Raleigh Organization
2.2 Roles and Responsibilities
All City employees have a responsibility to identify, and report observed illicit discharges to appropriate
staff. While the Stormwater Management Division implements the IDDE program, several other
departments have roles and responsibilities in regard to illicit discharge detection and elimination.
2.2.1 Stormwater Management Division
The Stormwater Management Division, housed within the Engineering Services Department, is
responsible for NPDES MS4 permit compliance, implementation of the IDDE program, and
enforcement of the Illicit Discharge Ordinance. The Stormwater Management Division includes
programs and staff that support a wide range of stormwater initiatives, including plan review and active
construction inspection, stormwater fee billing, asset management, drainage and water quality CIP
project management, public education and outreach, and water quality. An organization flow chart of
the Stormwater Management Division is maintained and located here: Stormwater Management
Division Organization Chart, and provides the total number of current staff, the breakdown of each
program within the division, and general roles within those programs.
Specifically, Water Quality staff is responsible for implementing the IDDE program and acting as the lead
for illicit discharge response, investigation, coordination, and enforcement actions as defined in the City’s
Illicit Discharge Ordinance. These responsibilities are further detailed in Sections 3 and 4 of this
document.
2.2.2 Other City Divisions and Departments
Several City departments play a role in IDDE and coordinate with Water Quality staff. See Table 2 for a
list of other City departments that are involved with IDDE response and IDDE events. More detail is
provided below on their respective responsibilities and coordination with other departments.
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Table 2 Other City Departments Involved in IDDE Response
City Department IDDE Event
Public Utilities Public Sanitary Sewer Overflow (SSO)
Transportation/Transportation
Field Services
Illicit discharges in the MS4, primarily in the City’s right-of-
way (i.e. City streets)
Public Utilities Private SSOs and cleanout overflows impacting or with
potential to impact surface waters
Public Utilities Water lines/service connections
Public Utilities Fats, oils and grease (FOG) in sanitary sewers
Housing and Neighborhoods Dumping, trash, and SSOs that Stormwater staff determine
have no potential to impact surface waters
Raleigh Fire Department HAZMAT concerns and RFD response to vehicle
accidents/fires
Parks, Recreation and Cultural
Resources Illicit discharges on or reaching parks properties
Solid Waste Services Illicit discharges caused by trash trucks on City streets or on
Solid Waste Services properties
Raleigh Fire Department (RFD) is the City’s first responder and provides HAZMAT response capabilities.
When called on to support responses to spills and other discharges, RFD staff typically secure the scene
and assist responsible parties with containing a spill until a remediation contractor can begin clean-up.
Transportation Department, Transportation Field Services references the MS4 Operation and
Maintenance Plan to respond to complaints, prioritize repairs, and conduct routine inspections of
stormwater assets throughout the City. This workgroup regularly notifies Water Quality staff of possible
illicit discharges and can assist with remediation efforts for spills on City property or with the City Right of
Way (ROW) when a responsible party is not known.
Public Utilities respond to all public Sanitary Sewer Overflows (SSOs). Their response includes initial
assessment, containment, emergency repair, and notification to NCDEQ. Public Utilities also provides a
list of SSOs that reach surface waters to Water Quality staff for tracking and annual reporting to NCDEQ.
Public Utilities, Fats, Oils and Grease regulate and inspect grease traps and oil/water separators
throughout the City. This workgroup notifies Stormwater Quality staff of any impacts observed during their
inspections and routinely pursues enforcement actions in the event of grease spills. Public Utilities also
inspects, responds to, and repairs water line breaks that have the potential to become an illicit discharge.
Housing and Neighborhoods responds to public nuisance complaints and pursues enforcement actions
for municipal code violations. In the event of a private sanitary sewer tap failure or a potential illicit
discharge has been observed, Housing and Neighborhoods staff will notify Water Quality staff.
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Solid Waste Services (SWS) Department supports a large fleet of waste collection and transfer vehicles
that transverse the City daily. Department staff respond to any spills that occur in the Right of Way
(ROW), by assessing the situation, containing the spill, and contracting with a remediation company to
complete any necessary cleanup. Water Quality staff are notified of any spills that occur by SWS staff
and regularly provide technical assistance during the site remediation.
Other City departments, such as Parks, Recreation and Cultural Resources, have department-specific
spill guidance and staff designated to prevent, mitigate, and respond to illicit discharges and spills.
In addition, City facilities that have a site-specific Stormwater Pollution Prevention Plan (SWPPP) or Site
Pollution Prevention Plan (SPPP) have spill response guidance included in their respective site plan. The
City also has a Citywide Spill Response Guidance document that applies to all City departments.
The Citywide Spill Response Guidance document and SWPPPs and SPPPs are requirements of the
Pollution Prevention and Good Housekeeping (PPGH) program, defined by Section G of the City’s
NPDES permit. Refer to the PPGH Plan for additional information. This document requires that all
departments that have a spill or observe a possible illicit discharge to contact Stormwater Quality staff
via 919-996-3940 or illegaldischarge@raleighnc.gov.
2.2.3 Non-City Entities
Several adjacent municipalities, corporate entities, and enforcement authorities carry sole responsibility
or additional responsibilities when dealing with IDDE.
The City’s MS4 is interconnected with two regulated MS4s that accept and convey stormwater runoff to
and from the North Carolina Department of Transportation (NCDOT) and North Carolina State University
(NCSU) separate storm sewer systems. There are multiple points of interconnection between the City’s
system and NCDOT’s system, and between the City’s system and NCSU’s system - primarily at the edges
of the roadway rights-of-way. Coordination is conducted by the City’s Water Quality staff’s illicit discharge
coordinators and the non-City MS4 representatives when an Illicit discharge event occurs and
interconnect between jurisdictions, and actions are performed as identified in Sections 3 and 4 of this
document. All investigations, responses and correspondence is performed by the illicit discharge
coordinators and Water Quality staff and documented as required. All non-City MS4 permit holders are
responsible for compliance with their respective NPDES permit during an illicit discharge event and
reporting requirements with NCDEQ.
Table 3 provides a summary list of these entities and a brief description of the typical illicit discharge
event associated with that entity.
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Table 3 Other Responsible Entities
Organization IDDE Event
CSX Transportation Illicit discharges on CSX Transportation property
Duke Energy Illicit discharges caused by Duke Energy transformers or on Duke
Energy property
Durham County Illicit discharges in Durham County
Google Fiber Google Fiber related illicit discharges
NCDEQ/NCDWR Fish kill, underground storage tanks, fuel tanks, fuel spills, waste
water or sanitary sewer entering a natural watercourse
NCDOT Illicit discharges in ROW of NCDOT roads
Norfolk Southern
Railroad Illicit discharges on Norfolk Southern Railroad property
North Carolina State
University Illicit discharges on North Carolina State University property
Town of Cary Illicit discharges in Cary
Town of Garner Illicit discharges in Garner
Town of Knightdale Illicit discharges in Knightdale
Town of Wake Forest Illicit discharges in Wake Forest
U.S. Environmental
Protection Agency EPA inquiries and investigations on Federal property
Wake County Septic tanks
Wake County IDDE in Wake County
Wake County Public
Schools Illicit discharges on Wake County School property
Note: City of Raleigh staff will respond to illicit discharges that leave another MS4 or stormwater conveyance and
enters the City of Raleigh MS4 and assist other responsible entities as needed.
City staff regularly work with NCDEQ regional office staff during illicit discharge investigation and
remediation and may concurrently pursue enforcement action against responsible parties through
separate authorities. NCDEQ will regularly copy Water Quality staff on enforcement mailings where
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reporting was not completed by responsible parties or when violations of State Statutes or
Administrative Code are related to a site that has been subject to City enforcement action. NCDEQ
requires notification in the event of a fish kill, sanitary sewer overflow that reaches surface waters, large
fuel or oil spills that reach, or have the potential to reach, surface waters, and for spills associated with
underground storage tanks. Water Quality staff regularly report incidents that exceed reporting
requirement thresholds to NCDEQ on behalf of the responsible party and/or remediation company to
ensure proper notification occurs. City Stormwater will pursue enforcement in these incidents unless
NCDEQ requests to lead enforcement efforts.
In instances where a site holds a permit through NCDEQ to discharge into the MS4, City staff will defer
to NCDEQ staff to lead investigation and enforcement action. City staff will provide support and follow
up with any additional enforcement action as necessary.
3 Tracing Flow Paths of Discharged Substances
Once an illicit discharge is found and a source is identified and isolated, an assessment is performed to
track and map its flow path through the storm drain network and to the receiving water within the Upper
Neuse River Basin.
3.1 Available Information and Tools
Various information and tools are utilized from the State, County and City to support City staff in the event
of an illicit discharge to track its flow path. These include:
• MS4 Geospatial Data incorporated into various mapping tools that include SWUMA, iMaps,
PUMA, ESRI GIS software and other GIS platforms.
• North Carolina State Surface Water Classification Map that identifies all blue-line waterways
within the State.
• 303(d) list of waters that exceed water quality criteria
• USGS Hydrologic Unit Maps
3.2 MS4 Base Map
In fiscal year 2014, the City initiated an MS4 mapping program which compiled and documented all known
MS4 infrastructure and outfalls within the City’s corporate limits and extra territorial jurisdiction (ETJ) in a
geographic information system (GIS). Since this initial effort, the City has continually updated the MS4
mapping, which includes pipes, ditches, inlets, catch basins, culverts, headwalls, channels, manholes,
and outfalls, including sizes and inverts. The MS4 mapping updates are incorporated into the illicit
discharge detection and elimination program, which is described in Section 6 of the SWMP.
This geospatial data is utilized by City stormwater staff to support their illicit discharge investigations and
cleanup actions and utilized as a tool for communication and direction to other agencies, contractors and
representatives.
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The condition of the MS4 stormwater inlets and conveyance system are evaluated by Transportation
Department, Transportation Field Services, Stormwater Maintenance Gr oup on a regular basis.
Frequency of inspection and prioritization are further defined in the MS4 Operation and Maintenance
Plan.
3.3 Stormwater Outfalls
An Outfall means a point source as defined by 40 CFR 122.2 at the point where a municipal separate
storm sewer discharges to waters of the United Sates and does not include open conveyances
connecting two municipal separate storm sewers, or pipes, tunnels, or other conveyances which connect
segments of the same stream or other waters of the United States and are used to convey waters of the
United States.
Major municipal separate storm sewer outfall (or ``Major MS4 Outfall'') means a municipal separate storm
sewer outfall that discharges from a single pipe with an inside diameter of 36 inches or more or its
equivalent (discharge from a single conveyance other than circular pipe which is associated with a
drainage area of more than 50 acres); or for municipal separate storm sewers that receive storm water
from lands zoned for industrial activity (based on comprehensive zoning plans or the equivalent), an
outfall that discharges from a single pipe with an inside diameter of 12 inches or more or from its
equivalent (discharge from other than a circular pipe associated with a drainage area of 2 acres or more).
The Stormwater Management Division maintains a dataset identifying all Major Outfalls within the City’s
MS4, which is used to prioritize dry weather flow inspections as described in Section 6. Illicit discharge
investigations are not limited to Major Outfalls, but include all Outfalls as defined by 40 CFR 122.2.
3.4 Receiving Waters
The City’s MS4 discharges directly into receiving waters situated in the Neuse River Basin, and
specifically within four 10-digit Hydrologic Unit Codes (HUC) identified as Lower Falls Lake
(030202020106), Crabtree Creek (0302020108), Walnut Creek (0302020111), and Milburnie Lake –
Neuse River (0302020107).
Crabtree Creek, Walnut Creek, and Lower Falls Lake drain to the Neuse River that continues outside of
the City of Raleigh city limits and enters the Neuse River Estuary and the Pamlico Sound near New Bern,
North Carolina.
4 Illicit Discharge and Illicit Connection Response and Documentation
The following section discusses the response to a potential illicit discharge, the actions the City can take,
and the reporting requirements to maintain compliance with the City’s NPDES MS4 permit.
4.1 Intake of Notifications
Illicit Discharge notifications come from various sources and can include:
• Phone calls to the City of Raleigh stormwater hotline published on the City’s illegal discharge
website.
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• Emails to illegaldischarge@raleighnc.gov
• Observations and reporting by City staff.
• Interagency correspondence from entities outside of the City
• Emergency and first responders during an accident or incident.
4.2 Response and Investigation
The City’s Stormwater Management Division manages compliance of all stormwater, stormwater
conveyances, and waters of the State within the corporate limits of the City. If an illicit discharge is
observed and City staff are notified, City staff will follow the Illicit Discharge Detection and Elimination
standard operating procedure (SOP), SW-100 Internal Illicit Discharge Detection and Elimination, that
establishes procedures to address non stormwater discharges to the stormwater conveyance and waters
of the State.
IDDE staff will begin an investigation within 24 business hours, or as soon practicable, of the receipt of
notification of a potential illicit discharge and will perform an assessment of the situation by identifying
the stormwater infrastructure, contamination extent, flow direction, and the discharge point within the
area. Depending on the nature of the spill, IDDE staff will attempt to identify responsible parties and
communicate with emergency responders as needed to contain the source of the discharge and
remediate and restore the areas of contamination as each case dictates. Proper authorities will be
notified by IDDE staff if notification thresholds are met, or City staff deem it appropriate.
All investigation details are documented in an Illicit Discharge Investigation Form and submitted to
CityWorks. For more detail on the investigation procedure, see Section 6.0 within SOP SW-100 Internal
Illicit Discharge Detection and Elimination.
4.2.1 Enforcement Actions
The Stormwater Management Division has the authority to issue verbal and written warnings for minor
violations, as well as authority to serve written notices of violation (NOVs) by registered mail, certified
mail-return receipt requested, or personal service to the responsible party alleged to be in violation and/or
to the property owner.
In lieu of a NOV, a Summary of Memorandum is issued for illicit discharges that involves a City-owned
property or for which the responsible party is determined to be a City staff or City contractors.
The Stormwater Management Division also has authority to issue civil penalties based on certain criteria
having been met, which can be found within the IDDE SOP rev F, section 9.0 Issuance of Civil Penalties.
4.3 Safety
Upon arriving on the scene, staff should check for obvious signs of danger. If a hazardous material is
found or suspected, staff will report the illicit discharge to the Fire Department and refer to the Stormwater
Management’s Internal Use Only SOP for Managing Spills Which Threaten to Enter the Stormwater
Conveyance System (SOP Number SW-101) and/or reference the City-wide Spill Response Guidance
Document for further action.
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Personal protection equipment (PPE) including safety vests, safety shoes/boots and eye protection must
be used as the situation requires. PPE must be used by staff when responding to a spill or investigation
within the right-of-way (ROW), construction sites, industrial operations, or any other situations where staff
deems it is necessary. When on private property, staff should attempt to identify all property owners and
bystanders prior to conducting their investigation.
Staff should use caution when approaching a spill in a City vehicle. Staff should utilize the vehicle’s
emergency lights, park in a location that does not interfere with emergency response vehicles or site
remediation, and in a location does not impede the flow of traffic.
4.4 Documentation and Closeout
Per the City’s NPDES MS4 permit, it is required that the City retain records of all monitoring information,
including all calibration and maintenance records and all copies of reports for a period of at least five
years from the date of the sample, measurement, report, or application.
The City documents the date of investigation, any enforcement action(s) and/or remediation that
occurred. The City maintains and publicizes a Stormwater Hotline and an email address contact for
complaints to be reported to as a reporting mechanism(s) for the public to report illicit connections and
discharges. This email address is shared with the illicit discharge coordinators and staff. Once
information is received and reviewed, staff can then initiate the SOP SW-100 rev F 6.2 for investigating
a potential illicit discharge.
All investigations of potential illicit discharges are recorded in a Stormwater Investigation Report that
includes a summary and tracking information of the investigation in progress. Additional field notes are
timestamped and updated at the bottom of the report throughout the life of the investigation.
As the investigation is completed and a response is determined, as either a warning, notice of violation
and subsequent notice of compliance, all investigation photos, correspondence, and official documents
are uploaded to the City’s CityWorks database and are georeferenced by location of the incident. This
data is then used to generate the IDDE Repeat Violator WebApp, which allows staff to determine if the
same responsible party is responsible for multiple illicit discharges. Supplemental reporting tools
including Crystal Report and Microsoft Power BI are also utilized with this data to produce reports and
for tracking.
4.5 Reporting Requirements
The City is required to report, and/or to require the responsible party to report spills to the State of North
Carolina Department of Environmental Quality (NCDEQ) if they meet reporting thresholds. The NCDEQ
is responsible for communications and coordination of cleanups from discharges related to these
discharges that threaten to reach surface waters within authority given by the Federal Government. The
City’s Water Quality staff follows guidance as indicated in this document and reports to the regional
NCDEQ office during business hours (919-791-4200), or the after-hours, weekends, or holiday reporting
line (800-858-0368). NCDEQ is responsible for further coordination and compliance with federal
regulations and requirements.
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Table 4 provides reporting thresholds for typical Illicit discharge events and, where applicable, the
corresponding Code of Federal Regulations (CFR) associated with that illicit discharge event. Upon initial
reporting, additional follow up reporting may be required as directed by NCDEQ.
Table 4 Reporting Thresholds
IDDE Event Reporting Timeframes (After Discovery) and Other
Requirements
Visible sedimentation in a stream or wetland
1. Within 24 hours, an oral or electronic notification.
2. Within 7 calendar days, a report that contains a
description of the sediment and actions taken to
address the cause of the deposition.
3. Division staff may waive the requirement for a
written report on a case-by-case basis.
Oil spills if they are:
• 25 gallons or more
• Less than 25 gallons but cannot be cleaned up
within 24 hours
• Cause sheen on surface waters (regardless of
volume)
• Are within 100 feet of surface waters
(regardless of volume)
Within 24 hours, an oral or electronic notification.
The notification shall include information about the
date, time, nature, volume, and location of the spill
or release.
Anticipated bypasses [40 CFR 122.41(m)(3)]
A report at least ten days before the date of the
bypass, if possible. The report shall include an
evaluation of the anticipated quality and effect of
the bypass.
Unanticipated bypasses [40 CFR 122.41(m)(3)]
1. Within 24 hours, an oral or electronic notification.
2. Within 7 calendar days, a report that includes an
evaluation of the quality and effect of the bypass.
Releases of hazardous substances in excess of
reportable quantities under Section 311 of the
CWA (40 CFR 110.3; 40 CFR 117.3) or sec 102 of
CERCLA (40 CFR 302.4) or G.S. 143-215.85
Within 24 hours, an oral or electronic notification.
The
notification shall include information about the
date, time,
nature, volume, and location of the spill or release.
Initial Spill Reporting Contact Information
Raleigh Regional Office: 919-791-4200.
After-hours, Weekends or Holidays: 800-858-0368
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In addition to reporting requirements to NCDEQ, Water Quality staff notify City management in the event
of an issuance of a civil penalty and of events where the City is the responsible party for an illicit
discharge.
The following notification flow chart and decision tree presented as Figure 3 details roles and
responsibilities for internal notification guidance.
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Yes
Determine Material
Conduct Site Investigation
Contain spill
Notify Authorities
Determine Responsible Party
Contact RFD immediately
if hazardous
NCDEQ: Fishkill, Sewage,
fuel/oil enters natural
RFD: Hazmat, gasoline,
large spills
Call/Field visit
logged
Notify Water Quality
Manager/Stormwater Manager for
City-coordinated cleanup and/or
contractor payment
Notify
Senior
City
Coordinates
Cleanup
Responsible
Party
Determined?
Issue Notice
of Violation?
Responsible
Party completed
Remediation?
NO
NO
Yes
Yes
NO
No
Yes
Issue Notice of
Compliance
Confirm
Remediation
Add Remediation
costs to NOV
fines
Fine Paid?
No Yes
Contact the
COR
Attorney’s
Office
Is the COR
the
responsible
party?
Yes
NO
Complaint/ Report
Received
Conduct Field
Visit
Illicit
Discharge
Notify Stormwater Manager, issue a
Summary of Memorandum to
responsible department, and confirm
remediation
Illicit Discharge Coordinators Engineer/Senior Engineers Water Quality Manager Stormwater Manager
Figure 2 Stormwater Management Division Notification and Enforcement Decision Tree
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5 Dry Weather Flow Inspection
Stormwater Management Water Quality staff conduct dry weather flow inspections of outfalls annually to
screen high priority outfalls for illicit connections or illicit discharges that may be occurring. All outfalls that
meet the criteria of a Major Outfall will be inspected during each permit cycle and annually when feasible.
At the start of each reporting year, an annual outfall inspection list will be generated to identify outfalls to
be inspected to account for updates to the inventory.
5.1 Inspection Protocols
Historically, the targeted outfalls have been prioritized based on the following criteria: land use, pipe size,
watershed, intersection with a sanitary sewer line and location within the Neuse Riparian Buffer.
5.2 Response and Investigation
Dry weather flow inspections are conducted on Major Outfalls as defined in this document in section 3.3.
Initial screening utilizing water quality field tests are available for staff are used to assist in identify sources
of dry weather flows. Enforcement action may be taken when an illicit connection or an illicit discharge
is discovered, and the source is confirmed or has potential to negatively impact water quality. SOP SW-
103 Outfall Inspections for Illicit Discharge Detection is used by staff to complete this task annually.
5.3 Documentation
All Dry Weather Flow inspections are recorded in the field through the CityWorks application and tracked
geospatially. This data is collected on the City’s servers and can be utilized for reporting, documentation,
and decision making.
6 Training, Education, and Outreach
6.1 Stormwater Management Staff
Water Quality staff are trained in multiple disciplines that span a wide range of stormwater topics. Specific
to IDDE, staff mentorship and internal instruction on NPDES permit and SWMP requirements is required
and reinforced through regular duties and during program assessment. Most Water Quality staff that
respond to ID complainants have completed the 8-HR HAZWOPER certification and regularly attend
informational webinars for topics specific to IDDE.
6.2 Other City Staff
All City employees complete Illicit Discharge Detection and Elimination (IDDE) training. The IDDE training
module is assigned to City staff via the iLearn training platform, a web-based platform that allows
employees to complete the training remotely, track completion status, notify the supervisor of their
employees’ training status, and generate weekly reports for Stormwater staff and reporting requirements.
IDDE training is part of the City’s new-hire, on-boarding process, which is implemented by the Human
Resources Department. All new employees are assigned this training and must complete it to clear the
required orientation process. IDDE training also then assigned to staff on a three-year cycle via the City’s
iLearn internal/on-line training platform. Staff and their supervisors are notified of the upcoming required
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training and/or failure to complete the training as assigned. Stormwater staff also provide In-person
training upon request. Stormwater staff coordinates with department staff to assist with the training
implementation and ensure that all employees have access to the training.
6.3 General Public
Since the 1990s, the City’s Water Quality Section has conducted public education and outreach activities
that fulfill the requirements of its Phase I NPDES MS4 permit. In 2009 a permanent, fulltime Stormwater
Education Specialist position was created to manage the Stormwater Public Education and Outreach
Program. This position since has been dedicated to educating the community and conducting outreach
activities focused on the impacts of stormwater runoff and discharges to surface waters.
In addition to these activities, Water Quality Section staff regularly work with Communications staff to
identify pollutant sources that are routinely identified through IDDE investigation and enforcement action.
This coordination allows for City staff to determine target audiences and an appropriate media to conduct
regularly IDDE-specific public outreach efforts. Throughout each reporting year, Water Quality staff
typically will assist with coordination in at least three public outreach and education efforts that pertain to
ID prevention and education. Topics include sewage, landscape maintenance, animal waste, paint,
wastewater and swimming pool water. Information is disseminated via multiple platforms including, but
not limited to, the website, print material, social media and email marketing. Additional detail and
references are included in the Education and Outreach Program Plan and the City-wide Spill Response
Guidance Document.
7 Program Evaluation and Reporting
The Stormwater Management Division uses several mechanisms to evaluate and track the IDDE program
effectiveness, including annual inspection reporting, regular review of existing plans and SOPs, tracking
of enforcement actions, and tracking of pollutant sources.
7.1 Effectiveness Evaluation
Water Quality staff conduct annual review meetings at the beginning of each NPDES MS4 permit
reporting year. All staff involved in implementing the IDDE Program attend, and the meeting agenda
includes evaluation of current practices and recommendations for program improvement. Any necessary
updates to program metrics, goals, and other processes associated with the IDDE Program are reported
to the Water Quality Manager who updates the City’s Stormwater Management Plan (SWMP)
accordingly. Any updates or changes made to the SWMP are documented in the City’s NPDES MS4
Permit Annual Report, which is submitted to NCDEQ.
7.2 Annual Reporting
City staff refer to the current SWMP to identify annual reporting metrics, track these metrics throughout
the year, and report these metrics to the Water Quality Manager at the end of the reporting year to include
in the NPDES MS4 permit annual report to NCDEQ.
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8 Revision History
Revision date Details
1.5.2022 Updated language throughout document, added acronyms, added Section 1.2.3 Allowable Non-stormwater
Discharges, and revised Figure 2.
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9 References
City of Raleigh, 2021. The City Code. September 10, 2021.
https://library.municode.com/nc/raleigh/codes/code_of_ordinances
City of Raleigh, 2021. City of Raleigh MS4 Operation and Maintenance Plan. January 2022.
City of Raleigh, 2021. City of Raleigh Stormwater Management Plan. June 2021.
City of Raleigh, 2021. City of Raleigh City-Wide Spill Response Guidance Document. November 2021.
City of Raleigh, 2021. City of Raleigh Pollution Prevention and Good Housekeeping Plan. December
2021.
City of Raleigh, 2020. Stormwater Education and Outreach Plan. August 2021.
City of Raleigh, 2012. SW-100 Internal Illicit Discharge Detection and Elimination. Standard Procedure,
amended May 17, 2021.
City of Raleigh, 2012. SW-101 Managing Spills Which Threaten to Enter the Stormwater Conveyance
System. Standard Procedure, amended December 1, 2020.
City of Raleigh, 2012. SW-102 Interdepartmental SOP for Managing Spills. Standard Procedure,
amended December 1, 2020.
City of Raleigh, 2012. SW-103 Outfall Inspection for Illicit Discharge Detection. Standard Procedure,
amended January 5, 2022.
NCDEQ, 2010. Total Maximum Daily Load to Address Impaired Biological Integrity in the Perry Creek
Watershed, Neuse River Basin. EPA approved May 13, 2010.
NCDEQ, 2003. Total Maximum Daily Loads for Fecal Coliform Bacteria and for Copper to Pigeon
House Branch, North Carolina. EPA approved June 2003.