HomeMy WebLinkAboutA2_NCS000249 Durham SMP-2020Submitted 1111812020
7. Stormwater Management Program (SMP) Plan
The goals of this SMP are to:
• Reduce the discharge of pollutants from the MS4 to the maximum extent practicable;
• Protect water quality; and
• Satisfy the appropriate requirements of the Clean Water Act-NPDES Program.
This SMP Plan details the proposed
program elements to be implemented
under the City's NPDES municipal
storm water permit, NCSOOO249. The
City's permit incorporates the six
minimum control measures now
required under the NPDES Phase II
program. It also includes other
provisions applicable to Phase I
programs. This SMP includes the best
management practices (BMPs) that
will be used to fulfill requirements, the
measurable goals for each BMP, the
implementation schedule (and
frequency, if applicable) for each BMP,
and the person or positions responsible
for implementation.
Annual reports will summarize the City's
progress in implementing the BMPs in the
SMP Plan, provide interim assessment of
the effectiveness of components of the
SMP, and, if necessary, propose
adjustments or changes.
Under federal Phase I stormwater
regulations, municipal permittees are
required to assess and evaluate the
effectiveness of their SMP over time and
revise or enhance best management
practices until water quality standards
are achieved. This iterative process,
shown in Figure 7-1t, is sometimes
referred to as adaptive management or
continual process improvement. This
process includes the steps of developing
a plan, implementing it, evaluating its
Figure 1: The Iterative Process of Stormwater
Management
igure 2: Classification of Outcome Levels
Levelu-
Changesln
Recel ving':'Jnter
«unlit,
Le:e15-
Charges in Urban Runoff
& Crischar•„= (- ualit•.
Le •ael 4-Load Redi.,diors
----------------------------------
Le •ael B-Behavioral Chicane
R BMP Irnp,lernertation
Level 2 -Changes in Attltudes. ITowledge and A•. -rareness
Compliance v,ith Activity -Based Permit Requirements
effectiveness, and then repeating the
whole process until the desired water quality goals are met. The City of Durham's stormwater
r California Stormwater Quality Association (2007). Municipal Stormwater Program Effectiveness
Guide. California: CASQA.
7-1
Submitted 1111812020
program has undergone considerable evolution and will continue to do so under the current SMP
Plan.
Figure 7-2 shows the many different outcome levels at which effectiveness can be assessed. While
the ultimate goal is to restore and protect water quality in receiving waters, it is recognized that for
many pollutants knowledge regarding sources of the pollutant and how that pollutant moves through
the environment is incomplete. Adaptive management provides the opportunity to begin
management based on what we know, recognizing that much more information will be needed in
order to achieve restoration.
Assessing changes and establishing statistical trends in receiving water quality parameters based on
monthly monitoring data is a long-term activity that requires many years of data. The City began
regular monthly ambient water quality monitoring in January 2004. Since monthly monitoring began,
the area has experienced two severe droughts. Such variable climatic conditions may require a
larger than usual dataset in order to assess trends.
In general, outcomes higher on the pyramid in Figure 7.2 require much longer time -horizons for
implementation and assessment. The City has developed the capability of assessing changes in
receiving water quality as discussed in Section 3.1.1 and Section 7.9 of this SMP, and in the annual
Water Quality Monitoring and Assessment; however, the primary focus of assessment under this
SMP will be on levels lower in the pyramid. Compliance with this SMP focuses on Level 1
assessment. Through membership in the Clean Water Education Partnership, the City will evaluate
progress at Level 2 on the pyramid. Progress at Level 3 is documented at the individual site level.
During the term of the permit the City will periodically report on higher outcome levels as information
is available.
7-2
Submitted 1111812020
Contents
7.1 Introduction..................................................................................................................................5
7.1.1
City Organizational Structure...............................................................................................5
7.2 Public Education and Outreach on Stormwater Impacts............................................................14
7.2.1
Target Pollutants...............................................................................................................
16
7.2.2
Pollutant Sources..............................................................................................................
16
7.2.3
Target Audiences...............................................................................................................
16
7.3 Public Involvement and Participation.........................................................................................19
7.3.1
Volunteer Community Involvement Program...................................................................
20
7.3.2
Mechanisms for Public Involvement................................................................................
20
7.3.3
Public Notice......................................................................................................................
21
7.4 Illicit
Discharge Detection and Elimination.................................................................................22
7.4.1
Legal Authorities...............................................................................................................
24
7.4.2
Ordinance Administration and Enforcement...................................................................
25
7.4.3
Storm Water System Inventory.........................................................................................
25
7.4.4
Assessment and Evaluation of IDDE Program................................................................
25
7.4.5
Training of Municipal Employees Involved in Implementing the IDDE Program ...........
26
7.4.6
Reporting Mechanisms.....................................................................................................
26
7.5 Construction Site Stormwater Runoff Control............................................................................27
7.5.1
Durham County Erosion Control Program........................................................................
28
7.5.2
North Carolina Department of Transportation................................................................
29
7.5.3
North Carolina Land Quality Section................................................................................
29
7.5.4
City Reliance -On and Coordination -With Authorized Programs ......................................
29
7.6 Post
-Construction Site Runoff Controls......................................................................................31
7.6.1
Post Construction Stormwater Management Program ...................................................
36
7.6.2
Ordinances........................................................................................................................
36
7.6.3
SCM Design Standards.....................................................................................................
39
7.6.4
Development Review Process..........................................................................................
39
7.6.5
As -built Approval Process.................................................................................................
40
7.6.6
Establish nutrient sensitive waters (NSW) protection measures (for programs with
development or redevelopment draining to NSW waters).............................................................
42
7.6.7
Deed Restrictions and Protective Covenants..................................................................
43
7.6.8
Operation and Maintenance.............................................................................................
43
7.6.9
Setbacks for Built -upon Areas..........................................................................................
45
7.6.10
Educational Materials and Training for Developers........................................................
45
7.7 Pollution
Prevention and Good Housekeeping for Municipal Operations.................................46
7-3
Submitted 1111812020
7.7.1
Operation and Maintenance Program.............................................................................
49
7.7.2
Site Stormwater Pollution Prevention Plan (SPPP) for Municipal Facilities ..................
50
7.7.3
Inspection and Evaluation of Municipal Facilities...........................................................
51
7.7.4
Spill Response Procedures for Municipal Facilities and Operations .............................
53
7.7.5
Prevent or Minimize Contamination of Stormwater Runoff from all areas used for
vehicle and equipment cleaning......................................................................................................
54
7.7.6
Streets, roads, and public parking lot maintenance.......................................................
54
7.7.7
Staff Training.....................................................................................................................
54
7.7.8
Facilities.............................................................................................................................55
7.8 Program
to Monitor and Control Pollutants to Municipal Systems...........................................56
7.8.1
Inventory of Industrial Sites..............................................................................................
58
7.8.2
Inventory Maintenance.....................................................................................................
58
7.8.3
Inspection Procedures......................................................................................................
59
7.9 Water
Quality Assessment and Monitoring................................................................................62
7.9.1
Assessments and Monitoring under Previous Permits ...................................................
62
7.9.2
Assessment.......................................................................................................................
64
7.9.3
Monitoring Programs........................................................................................................
66
7.10 Total
Maximum Daily Loads (TMDLs).........................................................................................72
7.10.1
Existing Programs for Northeast and Third Fork Creeks ................................................
74
7.10.2
Future TMDL Response Plans..........................................................................................
76
7.11 References..................................................................................................................................77
7-4
Submitted 1111812020
7.1 Introduction
This section introduces the general organizational structure of the City, discusses the city and county
departments that play significant roles in carrying out this SMP and summarizes their general
responsibilities, discusses how the stormwater program functions are funded, and introduces
tracking of Stormwater Management Plan Goals and management practices that will be discusses in
subsequent sections.
The City of Durham has developed a Strategic Plan that guides overall management. The activities
undertaken to implement this stormwater management plan support a number of Strategic Plan
Goals. Other departments and work units support the goals that are supported by this SMP. Thus,
the Strategic Plan provides an opportunity to further improve coordination across city departments,
divisions and work units that share similar goals, leading to more efficient and effective effort.
7.1.1 City Organizational Structure
The City operates under a Council -Manager form of government. Budget authority rests with the City
Council which is comprised of seven members. The City has more than 2,600 full-time employee
positions authorized in the FY19 budget. The City provides police and fire protection, water and
sewer services, solid waste collection and recycling, public works, neighborhood improvement
services, transit and parking services, and administrative services. The City also engages in
community development, economic and work force development, and human relation activities.
Planning, building inspections and zoning enforcement are handled by combined City -County
Planning and City -County Inspections Departments. Public Works handles inspection of roads, water
and wastewater utility lines, stormwater conveyances, and stormwater management facilities.
An overall City organizational chart is provided in Figure 7-3 showing the departments and reporting
paths within the City. Annual reports will provide updates on the City's organizational structure.
7-5
Submitted 1111812020
Figure 7-3: City Departments Organization Chart (as of 10/29/2018)
Mayor and
I—
City Council
City
Attorney
r
I I
Manager
I
Audit I
_
Services ,
I
I
I
Administrative &Support I Operations
Deputy City Manager I Deputy City Manager
I
I
I
I
I
Bud et& `Ci 1Coun =G.n,.r.1Management r Emergency Services I Management
I
Equal Opportunity � Fire
8 E uit F Department Parks and
q rt HIi et} Retreat on
Assurance e�sn�sins goon
I
Finance IF..ppa7lm.n�
Public
Department t
{psn;nas�np} Works
tylCounty
Human CiEmergency Solid Waste
Resource Communications Management
Technnology Fleet Water
Solutions Management Management
See detailed figure
for Public Works
org chart
* County Line Department
City
Clerk
Office of
Public Affairs
Community Building
Deputy City Manager
=7,tylCo.un
JCil11.nin g
Department
Community
Development
Transportation
Economic &
Workfame
Development
Neighborhood
Improvement
Services
City of Durham
Departments
Organization Chart
7.1.1.1 Departments and Positions Responsible for SMP Implementation
NPDES permit NCS000249 includes requirements that apply to and impact many different
departments within City government and require coordination with several departments within
County government. City of Durham departments that contribute to the goals of the SMP include
Public Works, General Services, Water Management, Parks and Recreation, Fire, Technology
Solutions, Solid Waste, and Neighborhood Improvement Services. City and County combined
departments that contribute to the goals of the SMP include the Planning and Inspection
Departments. County departments involved include the Engineering (Stormwater and Erosion
Control), Emergency Management, and Public Health. Each of these groups and the role they play in
implementing the SMP Plan is summarized in the sections below.
Public Works Department
The Public Works Department contains the core functions responsible for managing, operating and
maintain the municipal stormwater system. The Public Works Department is organized under three
Assistant Directors, as shown in Figure 7-4. Annual reports will provide updates regarding the
7-6
Submitted 1111812020
stormwater functions within the Public Works Department, together with a table listing contact
names associated with key roles in implementing this SMP. Divisions and work groups within the
Public Works Department are discussed below.
Figure 7-4: Public Works Department Organization (as of 10/29/2018)
Directorof Public works
Office of the Director
Business .Services Manager
Executive A5sis.W F---J Operations & Safety
Asst, Director Asst. Director Asst. Director
Engineering Services stormwater & GIs Maintenance Operations
Engineering
GIS/Stormwater
Inventory Control
Design, 5urvey &
Billing
Utility Locate
Maintenance
Water Quality
Administration
Contract
Management
Stormwater
Street &
Development
Development
Stormwater
Review
Maintenance
Review &
Engineering
Services
Stormwater
Street
Infrastructure
Maintenance
Inspections
watershed
Street Cleaning
Planning &
Implementation
Stormwater
Maintenance
Figure 2-2. City of Durham Concrete
Public Works Department Maintenance
Stormwater
Functions Shaded Special Projects
Stormwater and G/S Services Division
This division is the lead in coordinating development, implementation and assessment of the
Stormwater Management Plan. Key elements of the plan are carried out by work groups within this
division. There are five work groups within the Stormwater and GIS Services Division:
• Stormwater Infrastructure
• GIS/Stormwater Billing
• Stormwater Development Review
• Water Quality
• Watershed Planning and Implementation
Stormwater Infrastructure Group - Major responsibilities are:
• Drainage Projects - stormwater construction projects within City Rights of Way or on City property
7-7
Submitted 11/18/2020
• Drainage Response - customer assistance with questions about drainage problems on private
property
• Floodplain Response - customer questions about: floodplain information, floodplain building permits,
and the National Flood Insurance Program
GIS & Stormwater Billing— Major responsibilities include:
• Stormwater utility billing and customer service
• Mapping parcel -based impervious surfaces to support billing
• Maintaining GIS inventories of the stormwater, water and sewer systems, as well as street centerlines
(stormwater system base map)
• Technical support for the SCM and 2015 investigations databases
To support stormwater utility billing the work group obtains aeriealimagery to aid in maintaining
current maps of parcel impervious surface. The work group also uses survey grade GPS instruments
to update inventory data and contracts for outside professional services to support mapping
functions.
Stormwater Development Review - Major responsibilities include:
Conducting seminars for the engineering and development community.
Review of preliminary plats, final plats, site plans and construction drawings for conformance with
engineering design and performance requirements for stormwater, management and treatment
• Management of acceptance As -Built certification process for completed stormwater BMPs
• Management of annual stormwater BMP inspection process
• Maintenance of the SCM Tool database of BMPs (under construction and completed)
• Operation of certification programs for As -Built certification and for annual inspection
The Stormwater Development Review work group includes Registered Professional Civil Engineers,
engineering technicians, and administrative staff. Stormwater development review group performs
many other duties including support for watershed planning in the areas of upland assessment, BMP
evaluation and identification of potential retrofit locations. The engineering development review
group reviews stormwater conveyance systems.
Water Quality -Major responsibilities of this group include:
• Illicit discharge programs
• Inspection of industrial and light industrial facilities
• Inspection of city facilities and technical support
• Water quality monitoring programs
• Watershed planning support
• TMDL response plans
• Municipal training
• Business outreach
The work unit maintains the water quality sections of the city's web page; periodically gives
presentations to the Environmental Affairs Board (EAB, citizen advisory group); inspects private and
Submitted 11/18/2020
city facilities; conducts dry weather outfall screening; investigates concerns from citizens and city
employees and collects monitoring data; identifies and eliminates sources of water pollution;
conducts enforcement; maintains databases for monitoring results, inspections and investigations;
ambient, benthic and lake monitoring; conducts water quality assessments (statistics, trends, load
calculations); supports watershed planning in the areas of stream assessment, water quality
assessment and modeling; prepares annual reports; coordinates development of the SMP;
coordinates with state regulators and state resource agencies; implements grant -funded
demonstration projects; and contracts for USGS gaging stations, laboratory services, database
maintenance, implementation for grant projects.
Watershed Planning and Implementation — Major responsibilities of this group include the following:
• Watershed planning
• Resident and local school outreach
• Green infrastructure
• Existing development retrofits, including planning and installation
• TMDL support
This work group leads the City's watershed planning and implementation, implements residential
stormwater education and outreach, and coordinates public participation and involvement.
Development of watershed implementation plans requires coordination across work groups and
departments, development of scope of services and contracting, coordination of data delivery (e.g.
GIS data, water quality data,) coordination of city participation in contractor -lead field activities
including stream assessment, upland source assessment, BMP assessment, and identification and
evaluation of potential retrofit locations. This work group also does planning and contracting for
retrofit planning, design and construction, and contracts with outside agencies to support Green
Infrastructure implementation, supplemental workshops, a Facebook page; develops and distributes
brochures, flyers, and guidance documents; conducts targeted mailings; participates in development
of the CWEP media campaign; promotes the stormwater hotline; works with contractors to produce
educational videos; coordinates a speaker's bureau; conducts workshops for educators and
homeowners; promotes or coordinates stream cleanups; and coordinates storm drain markers. To
further watershed protection efforts such as increasing the urban tree canopy and promoting
residential green stormwater infrastructure, the group partners with outside agencies including the
County Sustainability Office, Soil and Water Conservation District, and local watershed groups.
Street Cleaning —This work group is within the Maintenance Operations Division of Public Works
operates a fleet of street sweepers that clean city streets, gutters and inlet grates on stormwater
inlets. In addition, work details pick up trash along city right-of-way, manually clean bus -stops, and
perform dead animal pickup.
Stormwater Maintenance —This work group is within the Maintenance Operations Division of Public
Works maintains roadside ditches, repairs catch basins, uses video inspection equipment to assess
the need to repair or maintain buried pipes and features such as catch basins. When cleaning is
needed, Vactor trucks are used to clean inlets (e.g. catch basins) and associated piping.
Water Management Deaartment
The Water Management Department operates and maintains a water distribution system and a
sanitary sewer collection system, two water treatment plants, and two wastewater treatment plants.
The Water Management Department also operates an industrial pretreatment program to control
discharges of industrial waste into the city collection system.
7-9
Submitted 1111812020
The Water Management Department implements a water conservation program which offers rain
barrels, shower head replacement, and toilet replacement rebates. When opening hydrants to flush
the water distribution system, the discharged water is passed through a diffuser that contains a
dechlorinating agent.
The two wastewater treatment plants were initially upgraded to provide nutrient removal in the
1980s, and have since been further upgraded to state -of -the art treatment for nutrients. The
collection system serves users throughout the city with the exception of the Northeast Creek basin,
which is served by Durham County. The Water Management Department remediates the impact of
sanitary sewer overflows (SSOs) where possible by capturing the contaminated water and pumping it
back into the collection system. To assure complete capture, the department typically coordinates
with the Public Works Department's Water Quality Unit for water quality testing to assess the extent
of contamination.
Citv/County Planning Deaartment
The City/County Planning Department coordinates development review and implements a Unified
Development Ordinance (UDO)3. A key stormwater provision of the UDO are the requirements that
protect County -wide riparian and wetland buffers, water supply watershed riparian and reservoir
buffers, together with overlay zoning density limits in critical watersheds. Zoning enforcement within
the department ensures compliance with riparian buffers requirements after construction.
Other responsibilities under the UDO are zoning, subdivision, comprehensive planning, and local
area planning. The department manages reviews by the Joint City/County Planning Commission, the
City's Development Review Board (DRB), the Board of Adjustment (BOA), and City Council. In
addition, the department also coordinates the acceptance review process for site plan applications
to ensure completeness before the plans are distributed to Transportation Division, Engineering
Division, Stormwater & GIS Division, and the County Stormwater and Erosion Control program for
review.
Fire Department 6pill Response Program)
The Fire Department has a HAZMAT (HAZardous MATerials) Team that assists with containment of
spills. The Fire Prevention Bureau supervised by the Fire Marshall inspects all commercial buildings,
including industrial sites, regarding materials storage and fire safety.
Technology Solutions Department
The Technology Solutions Department manages computer systems, servers, and networks. Their
duties include maintaining computer network and associated servers, Geographic Information
System (GIS), enterprise databases, and various other databases. (Note that staff with the
Stormwater and GIS Services Division develop and maintain various databases and stormwater-
related geodatabases that support stormwater management.)
CityAttorney's Office
The City Attorney's Office handles stormwater- related legal matters, including permit review,
assistance with ordinance development, support of enforcement efforts, and review of contracts and
agreements.
Solid Waste Deaartment
3 This is also discussed in Section 3.1.2-3.1.4.
7-10
Submitted 1111812020
The Solid Waste Department provides curbside solid waste, curbside recycling collection and fee -for -
service curbside yard waste collection to residential customers. The department also provides
collection services to businesses and residents in the downtown area at designated pickup
locations. In 2008, the department began providing free bulky item and white goods collection. The
department provides support for City -sponsored stream clean ups in the spring and fall, as well as
year-round support for Adopt -A -Stream and Adopt -A -Street programs. A Solid Waste code
enforcement officer handles solid waste containers placed in the right-of-way for collection. The
department also operates the City's Household Hazardous Waste Collection Center, open five days
per week and funded in part by the stormwater utility; much of the hazardous material collected is
recycled. The department also operates a Convenience Center for drop off of materials that may be
reused or recycled.
Neighborhood Improvement Services
Neighborhood Improvement Services (NIS) handles enforcement of ordinance code pertaining to
litter, junk and debris, weedy lots, graffiti, abandoned vehicles and carts, as well as minimum
housing requirements. NIS addresses illegal set -outs and illegal dumping related to rental housing.
Durham County Stormwater and Erosion Control
This group is part of the Durham County Engineering Department. It administers a locally delegated
program under the City/County Unified Development Ordinance adopted by both City Council and
Durham County Commissioners.^ Responsibilities of the group include reviewing local construction
erosion and sedimentation control plans, issuing land disturbance permits, and conducting regular
monthly inspection of construction sites.
General Services Department
The General Services Department is responsible for project design; property acquisition;
construction; contract bidding; construction contract administration; inspections of most city
construction projects including buildings, parks, and trails (exceptions are public works, construction
at treatment plants and solid waste transfer facilities, and utilities projects related to water system,
sewer system, sidewalks and streets). General Services is also responsible for street trees and for
maintenance of landscaping and right-of-way. General Services also administers the City
Sustainability Roadmap, including the Greenhouse Gas Emission Reduction Plan.
Environmental Education and Public Involvement
The City has staff and funding dedicated to educating businesses and the general public about the
impacts of stormwater runoff. These efforts are complemented or supplemented by efforts
undertaken by other agencies that play an important role.
Parks and Recreation Department
The Parks and Recreation Department maintains park trails and greenways. The group also operates
programs at City parks and trails (including two dog parks). This group has partnered with the
Stormwater Services Division to operate pet waste stations in parks and along trails.
City County Inspection Department
This department is responsible for building permits and inspections. It also takes care of zoning
inspection and enforcement. Zoning enforcement staff members coordinate with the Water Quality
Unit on pollution prevention at automotive service facilities.
Durham City -County Emer—aencv Mana—aement
This is discussed at length in Section 3.1.3.
7-11
Submitted 1111812020
This is a county line department operated with funding from the city and county. The department is
responsible for county emergency planning and response, including handling chemical spills
(including coordinating spill response, clean up, and reporting). Department staff coordinate and
support the Durham Local Emergency Planning Committee (LEPC), a group of concerned individuals
from different local agencies and businesses within Durham County who work together to assure
that our community has the emergency planning and response capabilities to effectively prevent, or
mitigate, emergencies and disasters. Examples of issue that are significant for stormwater
management include development of a comprehensive and details list of the capabilities of
environmental cleanup companies operating in Durham County, and coordination on hazards of
discharges from industrial accidents.
Durham County Utilitv Division
Durham County operates the Triangle Wastewater Treatment Plant and a sanitary sewer system that
serves Research Triangle Park, which is an unincorporated area outside city limits. However, the
collection system extends beyond the boundaries of Research Triangle Park serving much of the
Northeast Creek watershed, including areas within the City of Durham. The division typically
coordinates with the Water Quality Unit in the City of Durham's Public Works Department when there
is a major sanitary sewer overflow within the City.
Durham County Environmental Health Division
The Environmental Health Division promotes and protects public health through mandated
inspections and the enforcement of local and state public health laws, rules and regulations. The
Division inspects restaurants and other food service facilities, as well as permitting and inspecting
septic systems. The division often coordinates with the City of Durham Stormwater Services Division
to resolve violations involving improper grease handling.
7.1.1.2 Funding
Funding for the City's stormwater program is provided through a stormwater utility. Utility fees are
based on the amount of impervious surface on a property. This is true of both residential5 and non-
residential development. Miscellaneous revenues are derived from review fees for land
development projects that require stormwater management facilities. The City's annual NPDES
reports include revenues and expenditures for the Stormwater Utility, positions funded by the utility,
and budget for the approved Stormwater Capital Improvement Program, and information on any
changes in utility rates.
Within Stormwater and GIS Services, budget needs are managed and coordinated by the Assistant
Public Works Director of Stormwater & GIS Services based on input from the work groups within the
division. The Assistant Public Works Director of Stormwater & GIS compiles the needs and initiatives
from all the groups across the Public Works Department and then works with its director to develop
the overall budget request for the Public Works Department. This budget then is sent to the City
Manager's Office and the City Council for further approvals.
7.1.1.3 Tracking SMP Plan Goals
The Public Works Department's Water Quality Unit department tracks a wide range of metrics to
assess work load, amount of time devoted to an essential task, as well as outcome indicators
showing efficiency or effectiveness. Most of these indicators are used for internal tracking and
management within the work unit to assess inefficiencies, inform training needs, enhance
accountability and maintain performance.
5 Fees for residential development are divided into three tiers. The lower tier is for those residential units with
less than 2,000 square feet of impervious surface; all other residences with more impervious areas are
assigned to the second or third tier.
7-12
Submitted 1111812020
Many indicators tracked by the Water Quality unit are also used to track progress toward meeting the
goals of this Stormwater Management Plan. The Water Quality Unit has developed a summary guide
of the performance metrics it tracks which includes some examples on how the data is assessed.
The summary guide includes examples showing how the data is used. In many cases, the examples
are from annual reports.
Metrics and indicators tracked by the Water Quality unit are also used to assess and report progress
toward meeting departmental work goals and the goals of the City's Strategic Plan, and thus are not
unique within either the Public Works Department or the city as a whole. The City establishes key
performance indicators for each department as part of the annual budget process, based on the
City's Strategic Plan Goals, approved departmental initiatives and City Council priorities. Public
Works tracks the key performance indicators assigned to it in the Budget Book as well as other
performance indicators for every division and work unit. Objectives, performance goals, and specific
work initiatives are established at the beginning of each fiscal year, and individuals from each work
group or division are assigned responsibility to update the statistics on a monthly basis. Selected key
metrics are reported monthly to City Management and City Council members to track progress
toward Budget Book and Strategic Plan goals. An online system using Clearpoint Strategy is used to
track performance indicators.
The City's annual budget includes results for departmental initiatives and key reporting metrics for
every department for the prior year, and establishes the key metrics for the upcoming fiscal year.
7-13
Submitted 1111812020
7.2 Public Education and Outreach on Stormwater Impacts
Objectives for Public Involvement and Participation
Permit NCS000249 requires the City to develop and implement a program of public education and
outreach. The permit provides the following objectives (italics indicate supplemental objectives
added by the City:
• Distribute educational materials to the community.
• Conduct public outreach activities, targeting pollution prevention information to specific
audiences.
• Raise public awareness on the causes and impacts of stormwater pollution and encourage
behaviors that will improve water quality.
• Inform the public on steps they can take to reduce or prevent stormwater pollution.
Table 2-1. BMP Summary Table for Public Education and Outreach
BMP Description
Measurable Goals
Responsible
Position
(a) Describe target
Target pollutants, sources and audiences are summarized
Water Quality
pollutants and target
in Sections 7.2.1 and 7.2.2 of this SMP Plan, and
Manager
pollutant sources
discussed in Appendix I.
(b) Describe target
audiences
(c) Informational
The City promotes and maintains the Stormwater Services
Pages maintained
Website
Website:
by each work unit.
www.durhamnc.gov/stormwater.
The City also financially supports, contributes material to,
Public Education
and promotes the Clean Water Education Partnership
Coordinator
website www.NC-cleanwater.org
(d) Distribute Public
Acquire or develop and distribute public education
Public Education
Education Materials to
materials to identified target groups.
Coordinator &
identified user groups
Pollution Prevention
Coordinator
Develop and distribute information to target business
Pollution Prevention
sectors via targeted mailing (one sector per year) and
Coordinator
industry -specific guidance documents.
Educate homeowners about target pollutants and
Public Education
stormwater issues (through Waterways and topic -specific
Coordinator
handouts).
(e) Promote and
Distribute customized giveaways to promote the hotline
Public Education
Maintain Hotline/Help
including pens, badge holders, ice scrapers, and reusable
Coordinator
line
straws. Create and promote short videos to promote
hotline.
7-14
Submitted 1111812020
Maintain a stormwater pollution reporting hotline.
(see Section 7.4
IDDE)
(f) Implement a Public
Media Campaign: Document campaign impressions for
Public Education
Education and Outreach
each type of media like radio and TV (including those
Coordinator and
Program
elements implemented locally or through a cooperative
Pollution Prevention
agreement).
Coordinator
Develop utility bill inserts about stormwater issues.
(Waterways)
Participate in community events and festivals through a
table -top display.
Maintain a speaker's bureau that gives presentations to
civic organizations, business and neighborhood groups.
Organize stream cleanups (Creek Week in spring, Big
Sweep in fall)
Provide outreach through informational workshops.
Outreach to classrooms and school groups.
Develop and promote videos to educate the public on
pollution sources and the city's effort to reduce stormwater
impacts
Engage and educate businesses around pollution
prevention best practices through the Stormwater STAR
Business Recognition Program.
Provide outreach through social media.
The City of Durham's stormwater education and outreach program uses research -based methods to
increase awareness and to promote changes in behavior. Program components are managed by a
Public Education Coordinator and the Pollution Prevention Coordinator, but other staff provide
significant support for speaker's bureau and community events.
A report to citizens called State of Our Streams (SOS) is produced in part to educate and engage
Durham's residents about water quality conditions and results from illicit discharge investigations to
citizens, as discussed under Public Participation and Involvement.
The City is a founding member of, and active participant in, the Clean Water Education Partnership
(CWEP), a cooperative effort between local governments and others. CWEP implements campaigns
in several media markets including Durham. The campaigns are intended to increase awareness and
promote changes in behavior. Annual campaigns change from year to year but may include
television, radio and/or cinema pre -show video spots, depending upon the target audience. CWEP
also maintains a website. The City actively participates in the development of CWEP's annual
campaigns, and also partners with other organizations on stormwater outreach and education.
Experience has shown that a variety of public outreach methods are required to reach the various
audiences involved. Methods used by the City for a given target continue to evolve. Detailed
information about public education and outreach efforts of Stormwater Services is provided in draft
standard operating procedures, which includes a list of references regarding effective outreach
methods. Table 2-1 summarizes the approaches.
The target pollutants, their sources, and target audiences of public education and outreach efforts
are further described below. Further information about how these were chosen is available in
Appendix I.
7-15
Submitted 1111812020
Additional discussion of target pollutants and audiences that may be specific to a particular
watershed will be provided in Section 7.10 Total Maximum Daily Loads (TMDLs). Updates to these
plans are provided as attachments to the City's Annual reports and report on watershed specific
outreach. Watershed specific discussion is also provided in the watershed plans the City is
developing or updating.
7.2.1 Target Pollutants
Target pollutants for stormwater education include: fecal coliform bacteria, nitrogen, phosphorus,
low DO, turbidity, copper and zinc. Although hydrologic modification is considered pollution, and not
a pollutant, increased flow is a condition that has been identified as a priority for public education.
Zinc and copper seem to be associated with the following sources: a limited number of industrial
sites, AC coil cleaning, air conditioner blow -down, discharges from fountains, discharges from
underground electrical vaults, and vehicles. The City adds zinc polyphosphate to the potable water
supply to inhibit corrosion. Therefore, potable water leaks, system flushing, and sanitary sewer
overflows may introduce zinc to surface waters. All of these sources will be addressed through
business outreach and industrial monitoring and inspection as well as with state permitting, and
illicit discharge monitoring and control.
7.2.2 Pollutant Sources
Target pollutant sources include:
• Illicit Discharges - Illicit discharges both generally and specifically including improper cleaning,
improper storage, and improper disposal of pollutants;
• Sewage - Sewage from private and public components of the gravity sewer collection system that
may include overflows and blockages caused by food wastes and cooking grease from problem
restaurants and from residents of the City;
• Vehicle Maintenance - Petroleum products and automotive fluids from owner -maintenance of
vehicles and from automotive service facilities;
• Construction Sites - Sediment and/or erosion from construction sites;
• Landscape Maintenance and Lawn Care - Landscape maintenance and lawn care including use
of herbicides, insecticides and other pesticides along with improper yard waste disposal; and
• Atmospheric Deposition - Broad efforts to improve air quality, reduce emissions of greenhouse
gasses, and reduce dependence on petroleum will have water quality benefits.
7.2.3 Target Audiences
Based on the identified target pollutants and their sources, the target audience of this program are:
General Public - The general public may be educated to recognize and report illicit discharges.
The general public has been selected because of the widespread impacts of routine human
activities and the general lack of awareness of the impacts of stormwater runoff.
• Homeowners - Desired behaviors (or behavior changes) from educating this audience include
activities involving lawn maintenance and stormwater runoff.
• Lawn Maintenance -Desired lawn maintenance behaviors include having soil tested before
applying fertilizers, reading instructions on any chemicals (including fertilizers, pesticides, and
herbicides) before applying them to a lawn or garden, not applying lawn chemicals before it rains,
minimizing fertilizer usage (especially "weed -and -feed" fertilizer), using slow -release organic forms
of nitrogen fertilizer, using a composting lawnmower that can help reduce fertilizer usage, using
7-16
Submitted 11/18/2020
integrated pest management rather than broad spectrum pesticides on a regular basis, and
keeping leaves and grass clippings out of the street gutter by properly disposing of or composting
them. It also includes items such as having lawns aerated, encouraging practices that help
establish deep root systems for lawns, and putting in rain gardens (all of which will help
encourage water infiltration).
• In addition, homeowners that live next to a stream will be encouraged to not mow stream banks.
We also would like them to establish vegetative buffers and plant trees along stream edges that
will provide shade help anchor soil in stream banks, filter nutrients from shallow groundwater, and
provide a source of leaf packs that will help keep the food chain stabilized in the river or stream.
• Rooftop Runoff - We would like to encourage homeowners to disconnect rooftop drains from the
MS4 by directing them to lawns (which might include rain gardens) or connecting them to larger
rain barrels or cisterns. In addition, homeowners could regularly clean organic debris from their
gutters (this helps keep bacteria and organic matter from entering our streams). Homeowners
can also plant trees that will shade driveways and other paved surfaces that can lead to hot water
flashes with a rain event.
• Other Activities - Homeowners should dispose of grease properly to keep it from entering and
clogging the sanitary sewer system, properly dispose of household hazardous waste, keep lids on
garbage bins tightly closed to keep out animals, wind, and rain that could cause litter or "garbage
juice."
• Vehicle Owners - Vehicle owners will be encouraged to properly dispose of any wastes from home
maintenance, regularly maintain vehicles so that they don't leak fluids, and to wash their vehicles
in such a manner that the run-off doesn't enter storm drains.
• Pet Owners - Should pick up after, and properly dispose of, their pet's wastes.
• Students/Young People - Some long -held practices, activities and behaviors have been shown to
contribute to water quality degradation. Younger people are less resistant to changing their
behavior and can help initiate such changes in the rest of society.
Businesses - Target business sectors will include:
• Automotive Maintenance Facilities - With this group we want to advance the proper usage,
storage, and disposal of automotive fluids and other wastes such as tires. We will also educate
this group about their responsibilities regarding spill cleanups and notification of the correct
officials.
• Rental Property Owners and Managers - We hope to leverage this group to educate their tenants
through information distribution. In addition, we will educate property owners and managers about
their responsibilities for repairing and maintaining sewer service lines and remediating sewage
discharges.
• Landscape Professionals - This group can be educated about proper choice and application of
lawn chemicals such as pesticides, herbicides, and fertilizers. This group would also be an ideal
way to help encourage proper vegetative buffers and stream bank maintenance.
• Restaurants - Restaurant employees will be educated about proper grease disposal and other
equipment cleaning procedures.
7-17
Submitted 1111812020
• HVAC Contractors- HVAC contractors and their state business association will be trained in proper
disposal of wastewater from washing coils, vent cleaning, maintenance of filter units, and
pressure washing.
Not all of the audiences identified above will be addressed each year. However, each audience will
be addressed at least once during the permit period. Furthermore, Stormwater Services intends to
be reactive to new information and to regulatory programs (including state rules, TMDLs, and NSW
management plan requirements) and will review existing programs and initiate new outreach
activities as they are needed.
7-18
Submitted 1111812020
7.3 Public Involvement and Participation
Objectives for Public Involvement and Participation
Provide opportunities for the community, including major socioeconomic and ethnic groups, to
participate in program development and implementation.
General Approach
The City uses a variety of methods and mechanisms to involve the public and to solicit comments on
projects, initiatives and overall program development. The methods and mechanisms continue to
evolve.
Table 7.2 contains a summary of the BMPs used to involve citizens in the stormwater management
process and involve them in protecting our local water quality. Details on each approach are found in
standard operating procedures.
Table 7-2: BMP Summary Table for the Public Involvement and Participation
BMP
Measurable Goals
Responsible Position
a) Volunteer
Organize/sponsor volunteer stream cleanup campaigns that
Public Education
Community
promote resident participation such as Creek Week cleanups and
Coordinator
Involvement
Big Sweep cleanups.
Work with residents to label storm drains.
Program
Sponsor an adopt -a -drain program.
Sponsor adopt -a -street and adopt -a -bus stop programs.
Executive Director,
Keep Durham Beautiful,
Inc.
(b) Establish a
Presentations to the Environmental Affairs Board, typically
Depends on topic
Mechanism for
including annual Water Quality Monitoring Plan, Water Quality
(generally Water Quality
Public
Recovery Programs, and other topics of interest.
Manager)
Involvement
Annual reports and latest SMP have been posted on City web
Water Quality Manager
site; public comments will be solicited annually with revision
cycle.
Public meetings are held to solicit public input on watershed
Varies by project
plans, major construction projects, retrofit plans, ordinance
revisions
(c) Maintain a
The City will continue to maintain and promote a stormwater
See Table 7.1(e) and
Hotline
pollution reporting hotline.
Table 7.3 (e)
(d) Public Review
Stormwater Management Plan has been posted to web site
Water Quality Manager
and Comment
together with solicitation of comments and suggestions from the
public. Revised versions are posted after approval by NCDEQ.
(e) Public Notice
Comply with State and City public notice requirements for rate
Assistant Public Works
changes; watershed planning; proposed projects that impact
Director, Stormwater &
public use, public access or adjacent properties; and similar
GIS Services*
activities. Comply with City policy PA-3.
Notify public of other opportunities to participate.
* Responsible party listed for stormwater rate and ordinance changes.
The City is preparing a written Public Involvement and Participation Standard Operating Procedures.
7-19
Submitted 1111812020
7.3.1 Volunteer Community Involvement Program
In addition to the volunteer activities provided in Table 7-2 (a), the City and County fund Keep
Durham Beautiful, Inc., an independent non-profit that engages volunteers in litter abatement, waste
reduction education and beautification. Keep Durham Beautiful leads stream cleanups and "adopt -a-
" programs, promotes the City's dog parks and the Canines for Clean Water social marketing
campaigns, and promotes "greening" such as Trees Across Durham.
Litter oriented adopt -a -programs include adopt -a -stop (bus stop), adopt -a -street, adopt -a -trail, and
adopt -a -park program. KDB also promotes adopt -a -tree (greening) and the City's adopt -a -stream
program.
Other efforts are undertaken by the County Sustainability Office.
7.3.2 Mechanisms for Public Involvement
Environmental Affairs Board
Durham City and County together established the City -County Environmental Affairs Board (EAB) to
provide advice on environmental issues. City and County staff from several different departments
routinely attend these meetings and bring issues to the attention of the EAB. The Durham
Environmental Affairs Board (EAB) consists of eleven members appointed by the City Council (5
members), Durham County Commissioners (5 members) and Durham County Soil and Water
Conservation Board (1 member). Stormwater staff members attend all meetings to address issues
that may arise.
City Stormwater Services makes several formal presentations each year to update the EAB and to
seek comment, feedback and guidance. Presentations made each year typically include the State of
Our Streams report to citizens, TMDL Recovery Plans, watershed plans, and other issues. For
meetings at which presentations are not scheduled, Stormwater Services rotates staff members
attending.
Watershed Improvement Planning
As part of the process of developing Watershed Improvement Plans, the city and its contractors
generally hold a kick-off meeting to alert the community of the project and the field work that will be
undertaken, and to solicit input and community concerns for consideration in the planning process.
Each plan may include different elements. Additional meetings usually include the priority system for
rating potential projects, the results of modeling scenarios to evaluate alternatives, and final project
findings.
Project Planning Public Meetings
The City holds public meetings to solicit public comment on planned major stormwater construction
projects prior to conducting detailed design. Such meetings are typically held for stream restorations
projects by the City or by partners on city property, major culvert repairs, and major stormwater work
in city parks.
Ordinance Development
The City holds public meetings each time the post -construction ordinance has been substantially re-
written.
Public Hearings
Durham City Council conducts a public hearing to receive public input prior to adoption of changes to
Stormwater Utility Fees, post -construction ordinances, or changes in penalties.
7-20
Submitted 1111812020
Additional mechanisms to communicate with, and to solicit concerns from, city residents and
businesses include:
• Residents can bring matters before City Council.
• Partners Against Crime districts, which usually focus on policing, but occasionally address
neighborhood issues.
• Inter -Neighborhood Council, a consortium of neighborhood organizations, typically meets monthly.
• Participatory Budgeting, a democratic process that allows residents to directly decide how to
spend part of the public budget.
Stormwater staff members attend these meetings upon request, or when it is expected that
stormwater issues will be discussed.
7.3.3 Public Notice
North Carolina law requires that city council hold public hearings before taking certain actions, such
as adopting changes in stormwater utility rates. The responsible person for these changes is the
Assistant Public Works Director, Stormwater & GIS Services.
Other parties are responsible for meeting other notice provisions.
Notice of city construction projects: Session Law 2015-246 (H44) section 12(b) requires cities to
provide written notice to property owners and adjacent property owners at least 15 days in advance.
The project manager or department director for the project is the responsible party for these notices.
City policy PA-5 covers Public Notification of Planned Service Interruptions and identifies notice
requirements for projects having low, medium, and high impacts on service. The project manager is
the responsible party.
Sanitary sewer overflows of 1,000 gallons or more must issue a press release press release to print
and electronic news media that provide general coverage in the county, and must publish a notice
for 15,000 gallons or more. The Superintendent, Water and Sewer Maintenance issues these press
releases.
7-21
Submitted 1111812020
7.4 Illicit Discharge Detection and Elimination
Objectives for Illicit Discharge Detection and Elimination
The City's illicit discharge detection and elimination program is designed to meet or exceed the
following permit objectives:
• Detect and eliminate illicit discharges and connections, including preventable spills and illegal
dumping, to the municipal stormwater system owned and operated by the City of Durham.
• Implement appropriate enforcement procedures and actions.
• Maintain a map showing the permittee's major MS4 outfalls to state receiving waters.
• Inform employees, businesses and the general public of hazards associated with illegal discharges
and improper disposal of waste.
• Prohibit non-stormwater discharges or flows from entering the drainage system, except as allowed in
Part I, Paragraph 9.
The National Urban Runoff Program found poorer water quality associated with areas of older
development than for any particular land use. Myriad factors contribute to this finding. Outdated
construction materials, standards, and practices are significant risk factors. Additionally, with age
comes weathering, settling, wear -and -tear, and other factors leading to functional decline. Older
areas of development are served by pipes that leak or break and have utility cross -connections that
may have been allowed previously or may have resulted from lack of care or supervision. According
to the EPA (1993), for some pollutants, illicit discharges contribute a larger portion of the total mass
discharged from a storm drain system than stormwater runoff. Finding and eliminating the source of
pollution is essential for restoring and protecting water quality in cities with older development. An
effective IDDE program is also one of the most cost-effective means of meeting pollution reduction
goals.
Durham is an historic community with some development dating back to the 1800s. The City has
found most illicit discharges where the City has older infrastructure. An effective IDDE program is
therefore essential to the success of the SMP.
The City began developing and implementing its IDDE program in 1994. Since then, it has continued
to refine its implementation by using multiple strategies, indicators, and techniques that have proven
successful overtime (as discussed in Section 3.1.1).
The City will continue to maintain an effective IDDE program as generally outlined below.
7-22
Submitted 11/18/2020
Table 7-3: BMP Summary Table for the IDDE Program
BMP Description
Measurable Goals
Frequency
Responsible
Position
Maintain Stormwater Management and
(a) Maintain
Pollution Control Ordinance to extent
Ongoing
appropriate legal
authorized under State law.
authorities to
Water Quality
Review experience with enforcement of
prohibit illicit
Manager
discharges and
Stormwater Pollution Control Ordinance
Annually
illicit connections
and evaluate need for minor
adjustments.
(b) Maintain a
Storm Sewer
Maintain a current map showing major
SW Billing &
system Base Map
outfalls and receiving streams.
Ongoing
GIS
of Major MS4
Administrator
Outfal Is
Maintain written procedures for
inspecting and screening major outfalls
(c)
and for identifying other outfalls to
Ongoing
inspect/screen, including timeframe,
Inspection/
areas to be targeted, and number of
Detection Program
outfalls.
EP&C Analyst
to Detect Dry
(inspection,
Maintain procedures to investigate
herOutFlows
Weather Flows at
concerns and complaints related to illicit
Ongoing
enforcement)
MS4 is
discharges and connections.
Maintain procedures for removing the
sources or reporting the sources to the
Ongoing
State to be properly permitted.
Conduct training for new municipal staff
Ongoing
involved with dry weather screening.
EP&C Analyst
Conduct training for municipal staff
(d)
involved with investigating and enforcing
(inspection,
Training of
prohibitions against illicit discharges and
Ongoing
enforcement)
Municipal
connections on detecting and
Employees
documenting illicit discharges.
Involved in IDDE
Identify work groups of municipal
employees likely to encounter illicit
Pollution
discharges and provide training on
Ongoing
Prevention
identifying and reporting illicit discharges.
Coordinator
Continue to promote and maintain
EP&C Analyst
(e)
pollution reporting hotline (560-SWIM)
Ongoing
(inspection,
Maintain Public
and other means for public reporting of
p p g
enforcement)
illicit discharges.
7-23
Submitted 1111812020
Table 7-3: BMP Summary Table for the IDDE Program
BMP Description
Measurable Goals
Frequency
Responsible
Position
Reporting
Regularly publicize mechanisms for the
See also Table
Public
Mechanisms
public to report illicit discharges as
7.2 (e)
Education
discussed in Section 7.2.
Coordinator
Continue to maintain database
Ongoing
documenting outfall inspections.
Continue to maintain a database and file
system to track dates of initial and follow-
EP&C Analyst
(f) Documentation
up investigations, photos and other
Ongoing
(inspection,
evidence, enforcement, actions taken by
enforcement)
the responsible party, etc.
Document control of sources or reporting the
Ongoing
sources to the State to be properly permitted.
7.4.1 Legal Authorities
Legal authorities are provided under the Stormwater Management and Pollution Control Ordinance
(Durham City Code Chapter 70, Article V, Section 70-492 through 70-542) (see Stormwater
Management Plan Appendix A), which allows the City to identify and remove non-stormwater
discharges that convey significant pollutants. Allowable and prohibited discharges under the
ordinance are consistent with permit provisions in Part 1, I(1) and I(1) of the City's 2018 permit. The
ordinance covers discharges to any part of the drainage system, and includes discharges to privately
owned drainage in addition to discharges to the city's Municipal Storm Sewer System. The ordinance
also requires businesses engaged in certain activities to implement pollution prevention practices to
reduce the likelihood of spills and other pollution sources. The ordinance authorizes multiple
administrative, judicial, and criminal options for progressive enforcement, as necessary. In specific
instances, the City's illicit discharge program may coordinate with other city and county departments,
and other regulatory mechanisms may also be employed to achieve compliance.
Methods used by the City of Durham to locate and eliminate illicit discharges continue to evolve. The
City periodically updates the following documents:
• Outfall Screening and Monitoring Standard Operating Procedures
• Industrial Outfall Screening and Monitoring Standard Operating Procedures
• Illicit Discharge Detection and Elimination (IDDE) Investigations Standard Operating Procedures
• Stormwater Inspections Program Standard Operating Procedures
• Guidelines for Enforcement of the Stormwater Management and Pollution Control Ordinance
• Memorandum: Assessing Civil Penalty Criteria
7-24
Submitted 1111812020
7.4.2 Ordinance Administration and Enforcement
The Stormwater Management and Pollution Control Ordinance authorizes a range of violation
remedies. The most commonly used remedy is an administrative enforcement process under which
the ordinance provides for notices and civil penalties.
Detailed administration and enforcement procedures have been developed for this administrative
enforcement process, including guidelines for issuing Notices of Requirement (NOR) and Notices of
Violation (NOV). The City maintains a set of digital example files for Notices that include commentary
and guidance. The City automated the computation of proposed penalties for citable violations. The
database in which investigations are recorded computes civil penalty amounts, taking into account
specific factors required by the ordinance. Proposed penalties are provided with each NOV. The
ordinance provides that the alleged responsible party may request an explanatory meeting to
discuss the City's evidence and to provide additional evidence, including mitigating or exculpatory
information. Such evidence and information may alternatively be submitted in writing for
consideration. Penalties may be waived in part or completely based on information and evidence
provided, including actions taken by the responsible party.
Other administrative, judicial, and criminal remedies are authorized by the ordinance in rare
situations where our typical administrative process does not achieve compliance.
Investigations and enforcement actions are tracked and documented in a multi-user database. A
map function in the database allows investigators to determine whether there have been previous
investigations and violations at a given location.
7.4.3 Storm Water System Inventory
The Stormwater and GIS Services Division has available extensive GIS mapping resources that are
helpful in guiding efforts to locate and eliminate illicit discharges. Stormwater system components
include inlets, outlets, pipes (12 inches and larger), culverts, etc. on public and private property.
Streams, ponds and lakes are available. Drainage watersheds (sewersheds) have been delineated by
major stream. The City has a well -developed process for updating these map features. Field staff
make use of the mobile app Esri Explorer for ArcGIS for convenient access to the above spatial data.
The City requires that new development projects conduct video inspection of stormwater piping
systems, and to correct issues and re -submit video prior to project acceptance. The City also requires
submittal of digital as -built drawings to facilitate updating and maintaining system base map and
inventories.
7.4.4 Assessment and Evaluation of IDDE Program
Stream monitoring is conducted for a variety of purposes, including to guide IDDE efforts. Annually,
the City assesses monitoring results. Monitoring results are also used to inform the seasonal focus
of the Outfall Screening Program.
In addition, the Water Quality Unit conducts monthly assessment of performance indicators for the
IDDE program related to workload, productivity, and outcomes. A few key indicators are reported in
the Public Works Department's Strategic Plan database to communicate results to the Public Works
Director and City management.
Assessment and evaluation allow tracking of changes in workload overtime, changes in efficiency,
need for follow-up investigations, categorization of the types of pollutant source eliminated, which
reporting mechanism was used to trigger each investigation, etc. Assessment can result in modifying
approaches.
Summaries of interesting assessment results are typically included in annual reports.
7-25
Submitted 1111812020
7.4.5 Training of Municipal Employees Involved in Implementing the IDDE Program
New technical staff hired to implement the IDDE Program must have at a minimum two-year degrees
in a science -related field, plus two years of related experience.. Initial training of new staff includes
SOP document review, training presentations, quizzes, job shadowing, and supervised field work.
Formal training generally occurs after new hires have successfully completed job shadowing, are
oriented to procedures, processes, and systems and are able to lead a simple investigation. Formal
training uses PowerPoint presentations with photo examples to cover various aspects of
investigations and enforcement. Formal training typically requires two half -day sessions and
includes written testing to assess understanding.
7.4.6 Reporting Mechanisms
The Stormwater and GIS Services Division maintains multiple methods for the public to report
pollution concerns. In addition to the pollution reporting hotline (Table 7.2(c) and 7.3(e)), the Division
uses and promotes the following reporting mechanisms:
• Pollution hotline (919) 560-SWIM
• Group e-mail address, stormwaterquality@durhamnc.gov
• An online reporting form on the Stormwater & GIS Services web site
• Durham One Call (919) 560-1200 telephone service that serves as a central point of contact for
information and services offered by the City of Durham.
7-26
Submitted 1111812020
7.5 Construction Site Stormwater Runoff Control
The construction site stormwater runoff control program is designed to meet or exceed the following
permit objectives:
• Reduce pollutants in stormwater runoff from construction activities, within the permittee's regulatory
jurisdiction, disturbing one or more acres of land surface and those activities less than one acre that
are part of a larger common plan of development.
• Provide procedures for public input, sanctions to ensure compliance, requirements for construction
site operators to implement appropriate erosion and sediment control practices, review of site plans
which incorporates consideration of potential water quality impacts, and procedures for site inspection
and enforcement of control measures.
• A locally delegated program that meets the state requirements and that covers the jurisdictional area
of the permittee complies with the required minimum measures of this permit.
North Carolina has a well -established program to address the impacts of construction site runoff.
This program pre -dates federal requirements in municipal stormwater permits. The Sediment
Pollution Control Act of 1973 as amended, NCGS chapter 113A Article 4, established the North
Carolina Sedimentation Control Commission to regulate construction site erosion and sedimentation.
The Commission promulgated Chapter 4 of Title 15A of the North Carolina Administrative Code,
specifying standards and requirements, with the North Carolina Department of Environmental
Quality, Division of Energy, Mineral and Land Resources, Land Quality Section as the primary
regulatory authority.
The Sedimentation Pollution Control Act of 1973 and the rules adopted pursuant to the Act
(hereinafter collectively "SPCA") allow for the North Carolina Sedimentation Control Commission to
delegate jurisdiction to agencies for certain types of projects, provided the program has been
approved by the Commission. To facilitate delegation, the Commission:
• Develops manuals and publications to assist in the design, construction and inspection of erosion and
sedimentation control measures;
• Conducts educational programs in erosion and sedimentation control directed toward persons
engaged in land -disturbing activities;
• Provides instructional materials for persons involved in the enforcement of the SPCA and its
regulations;
• Conducts periodic review of delegated programs, providing recommendations to improve program
administration; and
• Provides technical assistance in review of draft erosion and sedimentation control plans for complex
activities.
Within the City of Durham there are three programs that are authorized to implement the SPCA,
permit and inspect construction -related land disturbing activity in Durham. The following summarizes
the authorities of each:
• Durham County Stormwater and Erosion Control Division's erosion control program: construction
projects by entities that do not have the power of eminent domain (private projects, covers most
construction).
• North Carolina Department of Transportation: state road construction projects.
• North Carolina Division of Energy, Mineral and Land Resources, Land Quality Section has exclusive
jurisdiction over land disturbing activities that are conducted by the State, by the United States, by
persons with the power of eminent domain other than a local government, projects by a local
government or which are funded in whole or in part by the State or the United States or which related
to oil and gas exploration on the well -pad; the Land Quality Section also maintains independent
7-27
Submitted 1111812020
authority over projects regulated by delegated programs operated by Durham County and the
Department of Transportation.
7.5.1 Durham County Erosion Control Program
Within the City and County of Durham most construction projects are privately funded. Durham
County Stormwater and Erosion Control Division's erosion control program has delegated regulatory
authority for these projects.
Having erosion control regulated as a county -wide program is consistent with most other aspects of
land development regulation in Durham, which is guided by a City -County Comprehensive Plan and
regulated under a City -County Unified Development Ordinance, which is implemented by a City -
County Planning Department. The city does not exercise authority over an extra -territorial jurisdiction
zone, and thus does not have regulatory authority outside of city corporate limits. With county -wide
regulation, there is no need for project hand-off between county and city for projects initiated outside
city limits that have agreed to voluntary annexation at some future date in exchange for extension of
city utilities. Durham County's erosion control program provides uniform application of standards,
and continuous and consistent oversight of regulated projects through all phases of development.
Durham County has a long history of regulating sediment and erosion control. The Durham County
Board of Commissioners adopted a Commission -approved ordinance on September 10, 1984,
becoming one of the first delegated local programs in North Carolina. The Durham County Board of
Commissioners agreed to enforce the ordinance within the City of Durham, and the Durham City
Council adopted a Resolution authorizing the enforcement of this ordinance within the City of
Durham on October 1, 1984.
In 2006, the City and County replaced separate zoning and subdivision ordinances with a Unified
Development Ordinance (UDO). The City -County UDO includes the most current local erosion and
sedimentation control regulations. The UDO provisions applicable to sedimentation and erosion
control are primarily found in Appendix D to this Stormwater Management Plan, and include Sections
3.8, 12.10, 15.1, and 15.5. Appendix C to this Stormwater Management Plan provides Section 8 of
the UDO, which includes steep slope provisions of Section 8.8. Definitions are found in Section 16 of
the UDO.
The North Carolina Sedimentation Control Commission periodically reviews the UDO's erosion and
sediment control requirements. The Commission also reviews program implementation by the
Durham County Stormwater and Erosion Control Division, which continues to meet or exceed criteria
established by the Commission. The program will continue to be monitored by the state to ensure the
County effectively meets or exceeds the maximum extent practicable standard established by the
Sediment Pollution Control Act of 1973 and Chapter 4 of Title 15A of the North Carolina
Administrative Code.
Applicability requirements under the UDO exceed requirements of both the SPCA and the federal
stormwater regulations to control stormwater runoff from land disturbing activities that exceed one
acre (43,560 square feet). Section 12.10 of the UDO requires a permit for land -disturbing activity
that disturb 12,000 square feet or more, and an approved, engineered erosion and sedimentation
control plan (hereafter referred to as "approved ESC plan") for sites that disturb more than 20,000
square feet. In determining the applicable disturbed area, lands under one or diverse ownership
being developed as a unit (i.e. as a common plan of development) will be aggregated. Sites that
disturb less than 12,000 square feet are exempt from obtaining a permit prior to initiating land -
disturbance; notwithstanding this exemption, an erosion control plan and/or permit may be required
by the Sedimentation and Erosion Control Officer when off -site damage is occurring, or if the
potential for off -site damage exists.
7-28
Submitted 1111812020
Applications for land disturbance permits are reviewed separately from site plans. Under Section
3.8.1 of the UDO, if required under Section 12.10, an approved sedimentation and erosion control
plan or a land -disturbing permit must be obtained before commencing land disturbing activities.
Durham County Stormwater and Erosion Control Division's erosion control program includes
procedures for public input, sanctions to ensure compliance, requirements for construction site
developers to implement appropriate erosion and sediment control practices, review of site plans
that incorporate consideration of potential water quality impacts, periodic site inspection, and
procedures for enforcement of control requirements (described in Appendix E). The program also
includes qualification and experience requirements for the Erosion Control Technician positions
including, "...graduation from a technical institute or community college with a major in Engineering
Technology and some experience in engineering plan review or an equivalent combination of
education and experience." Program review is facilitated by an internal database to track project
reviews and site inspections. Ordinance requirements were revised and updated in 2009.
The City continues to promote the City's Pollution Reporting Hotline as a means that the public may
report water quality concerns, including observed erosion and sedimentation problems. The County
is developing a Muddy Water Watch App for reporting erosion and sedimentation issues that will
tentatively be released in March, 2019.
The Durham County Stormwater and Erosion Control Division's erosion control program is funded
through erosion control fees. This funding mechanism allows staffing levels to be adjusted based on
the construction activity levels.
7.5.2 North Carolina Department of Transportation
North Carolina Department of Transportation maintains self -review and self -inspection programs for
state road construction projects. The North Carolina Land Quality Section maintains independent
authority over these projects.
7.5.3 North Carolina Land Quality Section
The Land Quality Section, North Carolina Division of Energy, Mineral and Land Resources regulates
land disturbing activity for construction projects that have public funding, projects by persons with
the power of eminent domain, and projects by state and federal agencies. Cities, towns and counties
are considered agencies of the state.
The Land Quality Section operates a state-wide hotline, 1-866-STOPMUD. Land Quality Section staff
at the Raleigh Regional office are responsible for plan review and permitting within a 16 county area.
Many of the counties in the region do not have delegated programs, and in these counties, the
regional offices is responsible for permitting and inspecting erosion and sediment controls at
privately funded construction sites that disturb more than one acre. The Land Quality Section also
maintains independent authority over projects regulated by delegated programs operated by Durham
County and the Department of Transportation and periodically conducts inspection of their projects.
With such a large area to cover, response times are longer.
7.5.4 City Reliance -On and Coordination -With Authorized Programs
As authorized by the City's permit, the City will continue to rely on these three entities to comply with
this minimum measure. Each of these programs meets or exceeds federal regulations requiring
permitting and controlling development activities disturbing one or more acres of land surface and
those activities less than one acre that are part of a common plan of development.
Reports from city employees or members of the public received via the City's Pollution Reporting
Hotline or other means described in Section 7.4 of the Stormwater Management Plan may include
concerns related to construction sites. As part of the municipal employee training discussed in
7-29
Submitted 1111812020
Section 7.7, city engineering inspectors have been trained to identify and report illicit discharges.
Construction -related illicit discharges, such as washing out ready -mix concrete trucks to the drainage
system, are addressed under the City's Stormwater Management and Pollution Control Ordinance,
discussed in Section 7.4. While the City is not authorized to implement the SPCA, the City ordinance
provides independent authority to investigate and to conduct enforcement when sediment leaving a
construction site is accumulating off -site in City streets, City storm drains or other parts of the
drainage system, including waterways within the city. The City is beginning to develop a draft
standard operating procedure to guide inter -agency coordination with the County, including
determination of authorized SPCA agency for a given project.
Investigations conducted by City staff will continue to be tracked in the City's investigations
database. Trends will continue to be reported in in the illicit discharge section of annual reports.
7-30
Submitted 1111812020
7.6 Post -Construction Site Runoff Controls
Permit NCS000249 requires the City to develop, implement, and enforce a program of post -
construction stormwater runoff controls for new development. The objectives of the program
include:
• Managing stormwater runoff from new development that drains to the MS4 and that cumulatively,
since the baseline date applicable to that area of the City, disturbs more than the applicable
threshold6 (including projects that disturb less than the threshold but are part of a larger common plan
of development or sale).
• Providing a mechanism to require long-term operation and maintenance of structural stormwater Best
Management Practices (BMPs), also known as stormwater control measures (SCMs).
• Ensuring controls are in place to minimize water quality impacts.
Although major ordinance changes were adopted in 2012 and 2019, most of the City's post -
construction stormwater management program has been in place for many years, as described in
Section 3.1. For development on land draining to nutrient sensitive waters (NSW), NCS000249 Part
II (F)(2)(c) requires the City to develop, adopt, and implement an ordinance to ensure that the best
management practices for development reduce nutrient loading to the maximum extent practicable.
NCS0000249 Part I (K) requires the City to continue to implement provisions of the current
Stormwater Plan "until the Division approves any revisions to the Stormwater Plan."
The table below summarizes the BMPs to be implemented and maintained during the remainder of
the permit to meet the objectives of the Post -Construction Stormwater Management Program. Text
sections that follow the table further explain the management measure intended to meet this
requirement.
6 The disturbance thresholds in the City of Durham's Stormwater Performance Standards for Development
ordinance are all equal to or less than the threshold listed in the City of Durham's NPDES permit.
7-31
Submitted 1111812020
Table 7.4 BMP Summary Table for the Post -Construction Stormwater Management Program
BMP Description
Measurable Goal
Timeline
Responsible Position
(a) Post -Construction
Maintain an ordinance (or similar regulatory mechanism)
Ordinance has been
Stormwater Development
Stormwater Management
that authorizes a program to address stormwater runoff
developed, implementation
Review Supervisor
Program
from new development and redevelopment to the extent
ongoing.
allowable under State law.
Maintain the Reference Guide for Development and City
Implementation is ongoing;
Stormwater Development
of Durham Addendum to the NC DWQ Stormwater Best
changes will be made where
Review Supervisor
Management Practices (BMP) Manual.
needed to insure all policies
are clear, to improve SCM
design standards, or as new
or better information
becomes available.
Continue to implement the City's stormwater
Ongoing
Stormwater Development
development review process, which includes site plan
Review Supervisor
and construction drawing review, to ensure compliance
with the ordinance and SCM design standards.
Maintain the City's stormwater SCM as -built approval
Ongoing
Stormwater Development
process.
Review Supervisor
Further Improve and add additional functionality to the
Ongoing
Stormwater Development
Stormwater Control Measure (SCM) Tool ("the Tool").
Review Supervisor
Train Stormwater Development Review staff.
Ongoing
Stormwater Development
Review Supervisor
(b) Strategies which include
Maintain strategies that include a combination of
Ongoing; see (d) below
Stormwater Development
BM Ps appropriate for the
structural and/or non-structural SCMs implemented in
Review Supervisor
MS4
concurrence with (a) above. Provide a mechanism to
require long-term operation and maintenance of
structural SCMs. Require annual inspection reports of
The letters in the left hand column of this table reference the associated table of management measures for the Post Construction Stormwater Management
Program in the City's NPDES Permit NCS000249. This table starts on Part II, Page 6 of 16.
7-32
Submitted 11/18/2020
BMP Description
Measurable Goal
Timeline
Responsible Position
permitted structural SCMs performed by a qualified
professional.
A qualified professional means an individual trained
and/or certified in the design, operation, inspection, and
maintenance aspects of the SCMs being inspected, for
example, someone trained and certified by the NC State
for BMP Inspection & Maintenance.
Continue to require Stormwater Impact Analysis for each
Ongoing
Stormwater Development
development project.
Review Supervisor
Continue to require treatment for pollutants (in addition
Ongoing
Stormwater Development
to nitrogen and phosphorus) in areas for which Total
Review Supervisor
Maximum Daily Loads (TMDLs) have been established
for those pollutants.
Within 12 months of the effective date of this permit, the
Complete
Stormwater Development
permittee shall evaluate, and revise as needed, SCM
Review Supervisor
requirements, to be at least as stringent as the minimum
requirements in 15A NCAC 02H .1000.
(c) Deed Restrictions,
The permittee shall provide mechanisms such as
Ongoing
Stormwater Development
Protective Covenants
recorded deed restrictions, plats, and/or protective
Review Supervisor
covenants so that development activities maintain the
project consistent with approved plans.
Use recorded conservations easements to protect
Ongoing
Stormwater Development
property.
Review Supervisor
(d) Operation and
The developer shall provide the permittee with an
Ongoing
Stormwater Development
Maintenance Plan
operation and maintenance plan for the stormwater
Review Supervisor
system, indicating the operation and maintenance
actions that shall be taken, specific quantitative criteria
used for determining when those actions shall be taken,
and who is responsible for those actions. The plan must
clearly indicate the steps that shall be taken and who is
7-33
Submitted 11/18/2020
BMP Description
Measurable Goal
Timeline
Responsible Position
responsible for restoring a stormwater system to design
specifications if a failure occurs and must include a
legally enforceable acknowledgement by the responsible
party. Development must be maintained consistent with
the requirements in the approved plans and any
modifications to those plans must be approved by the
Permittee.
For each structural SCM required by ordinance, require a
Ongoing
Stormwater Development
recorded plat signed by the property owner(s) that
Review Supervisor
acknowledges long-term operation and maintenance.
For each completed structural SCM required by
Ongoing
Stormwater Development
ordinance, require an operation and maintenance plan,
Review Supervisor
i.e. 0&M Manual, which lists specific inspection and
maintenance activities required to ensure the proper
functioning and upkeep of a particular SCM. The
property owner/permittee is responsible for maintaining
the facility per a recorded stormwater facility agreement
and/or City ordinance.
Require annual inspection reports of permitted structural
Ongoing
Stormwater Development
SCMs performed by a qualified professional.
Review Supervisor
Conduct annual quality assurance inspections on a
Ongoing
Stormwater Development
portion of all reports, including at least one from each
Review Supervisor
certified inspector submitting reports.
(e) Educational materials
Provide educational materials and training for
Ongoing
Stormwater Development
and training for developers
developers. New materials may be developed by the
Review Supervisor
permittee, or the permittee may use materials adopted
from other programs and adapted to the permittee's new
development and redevelopment program.
7-34
Submitted 11/18/2020
BMP Description
Measurable Goal
Timeline
Responsible Position
Conduct seminars for engineers, architects, and
A minimum of two
Stormwater Development
developers at least twice a year.
workshops are conducted
Review Supervisor
annually.
Distribute information on post -construction program
E-mails sent on an as-
Stormwater Development
changes via the "Development Community" e-mail list.
needed basis.
Review Supervisor
Conduct voluntary SCM handoff meetings with
As requested by subdivision
Stormwater Development
developers and Homeowner's Associations of single-
developer and HOA.
Review Supervisor
family residential subdivisions.
7-35
Submitted 1111812020
7.6.1 Post Construction Stormwater Management Program
The City of Durham's post construction stormwater management program includes the following elements:
• Ordinances to address stormwater runoff from new development,
• SCM design standards,
• A development review process to ensure compliance with the ordinance and SCM design standards,
• An SCM as -built approval process to ensure an SCM was constructed as it was designed,
• An operation and maintenance program to ensure an SCM continues to operate as it was designed,
• The SCM Tool, a database used to track projects and SCMs, and
• Training for stormwater development review staff.
These program elements are discussed below, with the exception of the operation and maintenance
program, which is discussed in Section 7.6.5.
7.6.2 Ordinances
Prior to adoption of a Phase II post -construction ordinance in 2009, the City of Durham had been
implementing state -mandated programs that require and enforce post -construction management of storm
water discharges. Water supply watershed protection requirements (discussed in Section 3.1.2) meet or
exceed requirements of 15A NCAC 2B.0624. The City's Neuse River Stormwater Ordinance (discussed in
Section 3.1.6) complied with 15A NCAC 2B.0235. Together, the Water Supply Overlay and Neuse
Stormwater ordinance covered approximately 60% of the City, as shown in Figure 7-5 below.
To comply with the post -construction requirements of the City's NPDES municipal permit, the City adopted an
ordinance that became effective March 17, 2009. This ordinance went beyond Phase II minimums and
included nitrogen export limits and 1-year peak flow controls imposed citywide, essentially extending the
City's Neuse requirements throughout the City.
Anticipating the need for more stringent controls on nutrients, effective June 15, 2010, the City Council
adopted revisions to the Stormwater Performance Standards for Development to enhance protection of
water quality. Nitrogen export limits were reduced from 3.6 pounds per acre per year, to 2.2 pounds per
acre pre year, and a phosphorus export limit of 0.5 pounds per acre per year was added. These limits
applied citywide.
Additional revisions became effective July 6, 2012 with the adoption of an ordinance approved by the NC
Environmental Management Commission for compliance with Jordan Lake Nutrient Strategy and Falls Lake
Nutrient Strategy. The Jordan Lake Nutrient Strategy has since been repealed and an amended ordinance
was adopted May 20, 2019. Areas located in the City of Durham and Jordan Lake Basin are subject to
Phase II requirements as well as Water -Supply Watershed requirements where applicable.
The current ordinance is Chapter 70, Article X, Sections 70-736 through 70-744, and a link to the ordinance
can be found on our web site near the bottom of http://durhamnc.gov/895/Stormwater-Development-
Review.
This code section contains post -construction performance standards applicable throughout the City that
address both general Phase 2 post -construction requirements and Nutrient Management Strategy
requirements. The City -County Planning Unified Development Ordinance (UDO), which governs development
within the City, makes reference in Section 12.8 to the City Code indicated above. The post -construction
ordinance has been adopted as a City development performance standard, rather than through amendment
of the UDO, since Durham County is not required to obtain a Phase 2 NPDES Municipal Stormwater Permit.
7-36
Submitted 1111812020
Performance standards are generally not subject to vesting in the same manner as changes in planning and
zoning requirements.
The ordinance applies to projects that exceed minimum land disturbance thresholds shown in Table 7.5
below, and to smaller projects that are part of a larger common plan of development. The ordinance is
implemented through the City's stormwater development review process.
Table 7.5 Thresholds for Application of Stormwater Pollutant Requirements
Project Location
Land Disturbance
Limited Residential
Multifamily and Other
Jordan Lake Basin
1 acre
1 acre
Falls Lake Basin
0.5 acre
12,000 sq. ft.
Lower Neuse Basin
1 acre
0.5 acre
7-37
Submitted 1111812020
Figure 7-5: City of Durham Post -Construction Stormwater Treatment
FIT FAI LU
WAVAP
LEGEND
Streams
Neuse-Cape Fear Boundary
Watershed Boundary
Durham City Limits
® Durham City Jurisdiction
j_ I County Boundary
Nutrient Management Strategy
/// Falls
Neuse (not Falls)
Water Supply Watershed
- WSWS: E-A
WSWS: E-B
- WSWS: FIJ-A
WSWS: F/J-B
_ WSWS: MILR-A
® WSWS: MILR-B N
- Phase 2 - City n
- Phase 2 MSI - County N
0 1.5 3 6
Miles
Post -construction Limits on Nutrient Yield
Research Triangle Neuse R 3.6 lb-Nlacrelyear P - Not Required
Park (outside City Falls Lake 2.2 lb-Nlacrelyear 0.33 lb-Placrelyear
— - City Jursdiction as of 0210112019
Nutrient yield limits on nitrogen and phosphorus under the ordinance are shown in Figure 7-5 and the table
below.
7-38
Submitted 1111812020
Table 7.6 Nitrogen and Phosphorus Post -development Loading Limits
Project Location
Export Limit (pound/acre/year)
Nitrogen
Phosphorus
Falls Lake Basin
2.2
0.33
Lower Neuse Basin
3.6
Not required
Concurrent with the effective date of the 2012 ordinance, the City mandated use of the Jordan/Falls Lake
Stormwater Nutrient Loading Accounting (JFSAT) Tool developed by NC DENR for calculation of pre- and post -
development loadings from all development sites. The JFSAT Tool is currently required for projects in the
Lower Neuse Basin. Beginning April 15th, 2019, the latest version of the Stormwater Nitrogen and
Phosphorus (SNAP) Tool replaced the use of the JFSAT Tool for projects located within the Falls Lake Basin,
as well as the Jordan Lake Basin. Since the City adopted revised stormwater performance standards
removing the Jordan Basin New Development Regulations in May 2019, the need for the use of a nutrient
load accounting tool in the Jordan Basin was removed as well. The JFSAT Tool will continue to be required in
the Lower Neuse Basin until such time NCDEQ revises/readopts the Neuse nutrient sensitive waters
management strategy.
Watershed Protection Overlay ordinance provisions of the City -County LIDO include density limits and other
provisions, and remain as independently applicable requirements. While the water supply watershed
protection ordinance also includes water quality treatment, the treatment provisions are less stringent than
those of the Stormwater Performance Standards for Development, except for the NPDES Phase II
requirements.
The City will continue to implement and enforce these ordinances, making text revisions as needed for
clarity, legal purposes, etc.
7.6.3 SCM Design Standards
To regulate stormwater control measure design and construction, the City of Durham currently utilizes the
following:
• The 2009-2016 edition of the North Carolina Division of Water Quality Stormwater BMP Manual and its
associated BMP Manual Errata Sheet. These documents can be viewed or downloaded from the Division of
Energy, Mineral and Land Resources' website at https://deg.nc.gov/node/84034.
• The City of Durham Addendum to the State Manual, which can be found under the City's Stormwater
Development Review webpage at http://durhamnc.gov/895/Stormwater-Development-Review.
The addenda are the City of Durham's additions, clarifications, and exceptions to the NC DWQ's stormwater
BMP Manual.
The City will maintain its Reference Guide for Development and City of Durham Addendum to the State BMP
Manual, making changes to these documents where needed to address specific regional issues, improve
SCM design standards, or as new or better information becomes available.
7.6.4 Development Review Process
The City's Post Construction Stormwater Management Program utilizes a development review process, with
associated guidance and policy documents, to implement the ordinance. When reviewing and approving
development plans, the City uses a two stage process: Site plans, which show the layout of a development
and the location of all utilities (including SCMs), are approved first. A site plan will not be approved if it does
not meet the Stormwater Performance Standards for Development requirements.
7-39
Submitted 1111812020
Following the approval of the site plans, construction drawings are submitted for review and approval. The
construction drawings contain the specific details of the development, including the plans, profiles, and
design details of all proposed SCMs. The City's Reference Guide for Development, which can be found on
our web site at http://durhamnc.gov/DocumentCenter/View/3331 contains requirements and submittal
checklists for construction drawings..
Both site plans and construction drawings are required to be prepared by registered professionals.
Stormwater details on construction drawings must be signed and sealed by a Professional Engineer licensed
in North Carolina. The City's stormwater plan review is conducted by NC -licensed Professional Engineers, or
by Engineering graduates under the supervision of an NC -licensed Professional Engineer.
In conjunction with the 2012 and 2019 revisions to the post -construction performance standards ordinance,
the City revised ordinance provisions regarding SCM inspection, maintenance, repair and reconstruction
responsibilities, and expanded the enforcement remedies to allow more tools to address noncompliance.
The City will maintain its development review process, making changes to guidance documents and policies
where needed to obtain better results, or as new or better information becomes available. The City currently
has the following Standard Operating Policies (SOPs) in place: 10-4-04.00001- Stormwater Review of Final
Plants, 10.4.04.00002 - Stormwater Review of Rezoning Plans, and 27.21.04.00004 - Logging in
Submittals Stormwater Development Review.
7.6.5 As -built Approval Process
The City of Durham requires that the construction of an SCM be certified as to its actual constructed
condition in relation to the approved design for the facility. The Certification consists of the provision of as -
built drawings and supporting documentation demonstrating that the SCM was constructed in a manner that
accomplishes its designed functions. These Certifications must be submitted in accordance with the City of
Durham's As -built Program and must be reviewed by the City's Stormwater Development Review Section of
the Stormwater & GIS Services Division. Further information on the As -built program can be found in Section
8.6 of the Reference Guide for Development at
https://durhamnc.gov/DocumentCenter/View/3331/Reference-Guide-for-Development-?biId= .
The City has historically implemented a Stormwater Building Permit and Certificate of Compliance Issuance
Operating Policy to ensure that developers don't complete the development without completing the SCMs
(as described in the Letter to Industry: Stormwater Building Permit and Certificate of Compliance Issuance
Operating Policy, dated April 17, 2012). Under this policy, residential and commercial developments are
treated differently. For commercial developments, if the SCMs are not complete and the developer wants a
conditional Certificate of Compliance (also called a Certificate of Occupancy or CO), the developer must:
• Post a construction security to ensure completion of the SCMs, and
• Complete the SCMs in an established timeframe.
To obtain a final CO for a commercial project the developer must complete the SCMs and provide an
acceptable as -built package for them. Once the SCMs have been satisfactorily completed and the as -built
package has been accepted, the construction security is released.
Residential developments are handled differently to reflect that SCMs are often used for erosion and
sediment control during construction, and to accommodate the developer's cash -flow need to continue to
build and sell houses in order to complete the development. Thus, for residential developments, the policy
for building lots platted prior to October 1, 2015 ensures that SCM construction progresses along with lot
building by releasing building permits and COs in a progressive manner, however a construction security to
ensure completion of the SCMs must be provided when the first CO is requested. If the BMPs are not
complete and developer wants more building permits or COs, the developer must:
7-40
Submitted 1111812020
• Request in writing for consideration what additional lots they would like building permits or COs on, advise
what has been done recently (within last six months) to bring the SCM(s) to completion, and outline the
completion schedule with milestones to be met.
• Meet the milestones approved in the letter of request and complete the SCMs in an established timeframe.
The City places permit or CO holds in our application/permit tracking system (an enterprise software
platform called Land Development Office) to ensure the permit or CO holds remain so adequate leverage
beyond securities continues to keep the SCM(s) completion a priority for the developer.
The City's reaction to Session Law 2015-187 and subsequent Session Law 2019-79 changed the above
policy for single family residential building lots platted October 1, 2015 or later. The developer now must
provide an SCM(s) construction security of their choice for 125% of the reasonable estimated construction
cost of the SCM(s) prior to final plat approval. The City does not hold any building permits and the Session
Law has no timeframe for the developer to complete the SCM(s) as long as they are showing a good faith
effort. This new law effectively stripped the City of much of its leverage to ensure timely SCM completion.
If the SCMs are not completed or good faith efforts toward completion are not witnessed, the City believes it
has some options to obtain compliance, which includes calling the bond or demanding the construction
security and completing the SCMs, placing holds on building permits if any remain, and/or holding approval
of future plans if within the same development, etc.
The City will maintain its as -built approval process, making changes to guidance documents and policies
where needed to improve the process. The City currently has the following Standard Operating Policies
(SOPs) in place: 27-21-04-.00006 - Construction Securities (non-residential projects with permitted
Stormwater SCMs), 27-21-04-.00007 - Construction Securities (residential subdivision projects with
permitted Stormwater SCMs), 27-21-04-.00008 - Placing and satisfying conditions on parcels for building
permits (residential projects), and 27-21-04-.00009 - Placing and satisfying conditions on COs for non-
residential projects.
Through the Stormwater Performance Standards for Development ordinance and the Reference Guide for
Development, the City requires new developments to be analyzed for changes to both water quantity and
water quality. This analysis is called the "Stormwater Impact Analysis".
For water quantity, project engineers must analyze increases in the 1-year, 2-year, 10-year, and possibly the
100-year 24-hour storm event peak flow if applicable impervious area thresholds are met. The purpose of
these analyses are to ensure that the increases in volume, velocity, and peak flow of stormwater discharges
from proposed developments are addressed, in order to mitigate the impacts on downstream properties,
stormwater infrastructure, and conveyance systems.
The City of Durham currently requires the submission of a Stormwater Impact Analysis for all land
development activities when applicable impervious area and/or disturbance thresholds are met. If the
impervious cover proposed in the plan would increase the peak runoff rate during the 1-year event,
detention of the 1-yr event will be required. If an increase in the 2- and 10-yr peak runoff rates is proposed,
detention and/or offsite drainage improvements may be required. However, the City defaults to a 10% rule
before requiring mitigation. In the instance of infill developments, detention of the 100-yr event may be
required to mitigate against increases in yard or structural flooding immediately downstream of the
proposed development. Developers must provide stormwater SCMs to detain peak flows from any or all of
these design storms as necessary to mitigate impacts.
The City utilizes project -scale modeling tools for assessing nitrogen and phosphorus treatment by SCMs for
development projects. Beginning April 15th, 2019, the latest SNAP Tool was required for projects located
within the Falls Lake Basin. Prior to April 15th, 2019 the JFSAT was required for projects located within the
Falls Lake Basin. The JFSAT tool is required for projects located within the Lower Neuse Basin. The City has
adopted the latest approved version of the JFSAT to evaluate BMP performance for nitrogen and
phosphorous. The JFSAT was developed by NCDENR and approved by the NC Environmental Management
7-41
Submitted 1111812020
Commission. The JFSAT calculates nitrogen and phosphorus loading for development by assigning mean
nutrient concentrations to the stormwater runoff, volume reductions for differing land uses and BMPs, and
nutrient removal efficiencies for SCMs. With the recent revisions to the City's ordinance and usage of the
Tool, post -construction BMP selection is guided by applicable nitrogen and phosphorous loading limits and
the effluent concentrations ascribed to the various SCMs. The Tool inherently promotes the use of BMPs
that control both concentration and volume of runoff to the extent allowed under 15A NCAC 2H .1008.
Per the Stormwater Performance Standards for Development ordinance, if reductions are needed to attain
nitrogen and phosphorus limits, a certain percentage of that reduction must be achieved onsite via SCMs in
the Falls Lake Basin. Onsite goals can often result in two SCMs in series or oversized SCMs. After meeting
onsite goals, the remaining percentage reduction may be purchased from nutrient banks.
The City also requires control of Total Suspended Solids (TSS). If disturbance thresholds are triggered and
the impervious percentage of a development that increases impervious area equals or exceeds certain
thresholds (24% for Falls, Jordan, and Lower Neuse Basins), TSS treatment is required. Impervious surfaces
must drain to an SCM that removes a minimum of 85% TSS during the 1-inch water quality event.
Although nitrogen, phosphorus, and TSS are the primary pollutants of concern with regard to development,
the City also requires control of other pollutants in areas for which a TMDL has been established. In
particular, the City requires control of fecal coliform bacteria in the Northeast Creek watershed, which has a
TMDL for that parameter. The Stormwater Performance Standards for Development ordinance requires at
least one BMP in a treatment train to be selected for bacteria removal, based on having a fecal removal
ability of high or medium in Table 4-1 of the 2009-2016 edition of the NC Stormwater BMP Manual.
The City of Durham also uses several non-structural BMPs to mitigate the effects of development. The City
has adopted Natural Resource Protection Standards as part of the Durham City/County Zoning Ordinance
(Section 8). These standards specifically address tree protection and tree coverage, floodplain protection,
stream buffer protection, steep slope protection, and wetlands protection. The City also has zoning
ordinances to direct growth to identified areas. Durham has a large area located in highly developed (WS-IV
classification) watersheds and currently has water supply watershed rules contained within its zoning
ordinances. Also, the City's Parks and Recreation Department as well as the Planning Department manage
a program for maintaining and increasing open space. This program concentrates on preserving
environmentally sensitive and natural resource areas within the City including wetlands and riparian buffers.
The City will continue to require the Stormwater Impact Analysis to identify whether a development needs
one or more SCMs to comply with stormwater requirements, and which SCMs are appropriate.
7.6.6 Establish nutrient sensitive waters (NSW) protection measures (for programs with
development or redevelopment draining to NSW waters)
As discussed above in Section 7.6.1, land area within the City of Durham is currently subject to one of two
sets of State rules. These are listed in chronological order below:
• Neuse River Nutrient Sensitive Water Strategy
• Falls Lake Nutrient Sensitive Water Strategy
The Neuse River NSW Strategy required Durham and other local governments to adopt and implement
beginning in 2001 a post -construction ordinance for areas draining to the Neuse River Basin. The Falls Lake
NSW Strategy went into effect in 2010 and those rules required adoption of a post -construction ordinance in
2012.The Jordan Lake NSW Strategy went into effect in 2009 with the State rules requiring adoption of a
post -construction ordinance controlling nutrients from development and redevelopment also in 2012; these
requirements subsequently have been repealed and no longer apply beginning in spring 2019.
7-42
Submitted 1111812020
As shown in Figure 7-5, these two NSW Strategies collectively cover all of Durham that drains to Falls Lake
and the Lower Neuse River. The City has been implementing post -construction requirements for the Neuse
River NSW since 2001 Citywide nitrogen limits were included in the 2009 post -construction ordinance. The
ordinance was revised again in 2010 to implement interim nutrient loading limits for nitrogen and
phosphorous in advance of rule deadlines for Falls Lake and Jordan Lake. Effective July 6, 2012, the City
began implementing post -construction requirements for all three NSW rules. In the spring of 2019,
adherence to rules associated with the Jordan Lake Nutrient Sensitive Water Strategy will no longer be
required.
The City has been submitting an annual report for the Neuse River NSW Stormwater requirements. With
adoption of requirements for both the Jordan Lake and Falls Lake NSW strategy rules in 2012, annual
reports are required for the Falls regulations beginning in 2013. In 2012, the City began compiling
information about development plans approved in the Jordan Lake Basin, but annual reports have not been
required for the Jordan new development regulations. With the repeal of Stormwater Management for New
Development requirements in the Jordan Nutrient Strategy, annual reporting will not be required in spring
2019 or the foreseeable future, thus the City no longer compiles nutrient loading information for new
development in this watershed.
The City will continue to maintain its ordinance which implements NSW protection measures.
7.6.7 Deed Restrictions and Protective Covenants
SCMs are constructed as part of private property developments. The City uses recorded plats, City Code
requirements, and Declaration of Covenants, Conditions & Restrictions (CC&Rs) for all projects to indicate
restrictions that convey with a property. Projects completed under the pre -May 20, 2019 ordinance still
requires Stormwater Facility Agreements (a.k.a. Operation and Maintenance Agreements). Chapter 70
Article X Section 70-742, Chapter 70 Article XI Sections 70-750 through 70-752, and UDO Section 8.7
require the financial guarantees required to secure the operation and maintenance of the SCMs. For limited
residential development, requirements in Section 8.2 of the RGD explicitly require an Owner's Association,
specific covenant language to ensure that a development project will continue to be operated and
maintained consistent with approved plans, and payment into the stormwater facility replacement fund
managed by the City.
Impervious surface limits are required to be shown on recorded plats and are enforced by the City -County
Planning Department. The Building Inspections Department requires foundation surveys and final surveys to
ensure compliance. If building lots exceed allowed impervious cover during development of a subdivision,
plat revisions are required to balance impervious cover.
7.6.8 Operation and Maintenance
For each development project with one or more stormwater SCMs, the City's Stormwater Performance
Standards for Development Ordinance requires that:
• Meet city stormwater standards, including the most recently approved version of the Operation & Maintenance
Manual for the specific SCM, as well as the most recent version of the "Owner's Maintenance Guide for BMPs
Constructed in the City of Durham(https://durhamnc.g_ov/DocumentCenter/View/2239/Owners-Maintenance-
Guide-for-Stormwater-BMPs-PDF?bidld=)", and
• Provide for the construction and longterm maintenance, inspection, repair, and reconstruction of the SCMs in
accordance with City standards.
In the case of residential development intended for home ownership, the homeowners' association must be
created before the final plat is recorded.
7-43
Submitted 1111812020
The City ordinance requires sealed annual maintenance certifications (inspection reports) for all SCMs
constructed and approved. The inspection report is a sealed certification by a NC professional engineer or
NC registered landscape architect who has been certified by the City as a BMP maintenance certifier; this
certification process includes completion of a City of Durham approved SCM inspection and maintenance
workshop, similar to the Stormwater Inspection & Maintenance Certification workshop offered by North
Carolina State University. The inspection report is submitted to Durham Stormwater & GIS Services through
the StormwaterBMPs@durhamnc.gov email address following procedures specified in the City's BMP Annual
Maintenance Certification Protocol.
Each inspection report is to include an operation and maintenance (0&M) manual for the facility. The 0&M
manual lists specific inspection and maintenance activities required to ensure the proper function and
upkeep of a particular SCM. The City requires that all 0&M manuals address the following, at a minimum:
• The frequency of inspections that are needed (based on the type of SCM).
• The components of the SCM that need to be inspected.
• The types of problems that may be observed with each SCM component.
• The appropriate remedy for any problems that may occur.
• Inspection and maintenance records, which should be kept with the owner/responsible party.
In case of failures/deficiencies, the City continues to require a BMP maintenance certifier to develop a
remediation plan to bring the facility into compliance with the intent of the original design plans. The
remediation plan is to include an implementation schedule to be followed by the property owner. An
additional inspection report is required after the successful completion of all the remediation work.
The City reviews each submitted inspection report and conducts quality assurance (QA) site inspections on a
minimum of 50% of all reports. The selection of the 50% ensures that each BMP maintenance certifier is
included in the QA inspections. Additional information regarding the City's SCM Annual Maintenance
Certification Program can found on the City's webpage: http://durhamnc.gov/695/BCE-As-BuiIts-BMC-
Maintenance-Programs.
The City has adopted both hard and soft strategies, e.g. tiered compliance/enforcement strategies, to
increase the rate of compliance with the annual maintenance certification requirement. The first two tiers
are considered soft strategies which include educational documents, SCM handoff meetings (between
developers and homeowner associations), inspection reminder notices, and one-time warning notices. Tier
three strategies include notices of violations, opportunities to meet with the City to discuss violations,
monetary civil penalty assessment notices, permit withholds, and demands for agreement securities. Tier
four strategies include judicial type actions and other related actions. Additional information regarding these
strategies can be found in the document titled "BMP Maintenance Certification Compliance Enforcement
Program - A Brief Overview."
The City will continue to require a current operation and maintenance plan and annual compliance
certification for each SCM. The City will also continue to conduct QA site inspections on a portion of all
annual compliance certification reports, and will continue to implement hard and soft enforcement
strategies to improve compliance rates.
Operation and Maintenance for Municipally -owned or Maintained BMPs: City Stormwater and GIS Services
staff conduct annual maintenance inspections of municipally -owned or maintained structural BMPs to verify
conditions, operational issues, and maintenance needs. These assessments are documented in formal
maintenance inspection reports annually. The City may perform maintenance and rehabilitation of city -
owned SCMs through periodic contracts with vendors that have experience in conducting this work, as well
as with city work crews.
7-44
Submitted 1111812020
7.6.9 Setbacks for Built -upon Areas
In lieu of the 30-foot setback provided in the state's Phase II program, subdivisions and site plans are
required to protect 50-foot buffers on all perennial and intermittent streams, and ponds and lakes located in
a natural drainage way in accordance with the riparian buffer requirements in Section 8.5 of the UDO. Wider
buffers may be required under Water Supply Watershed overlay zoning districts.
A surface water is considered present if the feature is shown on either the most recent hard copy version of
the soil survey map prepared by the Natural Resources Conservation Service of the United States
Department of Agriculture or the most recent version of the 1:24,000 scale (7.5 minute) quadrangle
topographic maps prepared by the United States Geologic Survey (USGS). Relief from this requirement may
be allowed when surface waters are not present in accordance with the provisions of 15A NCAC 213 .0233
(3)(a). [See 15A NCAC 2H .0126(11) for exceptions to 15A NCAC 2H .0126(10)(e)(i)(A)(III) and 15A NCAC 2H
.0126(10)(e)(i)(B)(IV) j
In November 2010 the City and County adopted substantial revisions to riparian buffer requirements in the
City -County LIDO. These revisions were made largely to comply with Jordan Lake Nutrient Sensitive Waters
Strategy, 15NCAC 0213.0267 and .0268, but also to implement recommendations of the Environmental
Enhancements to the UDO Steering Committee and to consolidate buffer requirements in one section of the
UDO. The revised ordinance can be found online at htto://durhamnc.aov/414/.
7.6.10 Educational Materials and Training for Developers
The City provides educational materials and training for developers in the following ways:
• Two seminars per year are conducted for the development community on topics related to stormwater and
development review requirements in the City of Durham.
• Notification to its "development community" e-mail list regarding ordinance changes, changes to other
stormwater post -construction requirements and policies, training opportunities, and other information, on an
as -needed basis.
• Solicitation, via its "development community" e-mail list, of comments on changes to program implementation
documents, on an as -needed basis.
The seminars are presented by Stormwater and Engineering Development Review personnel. They include
design/review examples, updates on new engineering standards, revised ordinance requirements, operation
and maintenance plan elements, innovative SCM technologies, etc. Slides from the seminars are posted on
the City's web site at http://durhamnc.P-ov/1607/ for those that were not able to attend. Outside speakers
may be invited to enhance learning and communication.
Announcements to the development community are also posted on the Stormwater Services web site at
http://durhamnc.gov/905/. Letters to Industry policy documents are posted at
http://durhamnc.gov/1591/.
The City has begun a program to conduct voluntary SCM handoff meetings with developers and
Homeowner's Associations (HOAs) of residential subdivisions. This meeting occurs after approval of the
SCM as -built drawings. The purpose of these meetings is to provide a smooth transfer of SCMs from the
developer to the HOA, and to educate HOAs about the SCMs in their subdivision as well as HOA
responsibilities and obligations regarding those SCMs.
7-45
Submitted 1111812020
7.7 Pollution Prevention and Good Housekeeping for Municipal Operations
The objectives for this measure are to:
• Prevent or reduce stormwater pollution from municipal operations and municipal facilities.
• Train employees to incorporate Pollution Prevention and Good Housekeeping techniques into municipal
operations.
Pollution prevention and good housekeeping programs are an important factor in the improvement of
stormwater quality. Municipal maintenance facilities can be significant sources of pollution if not managed
properly. Other municipal activities, such as waste collection, offer significant opportunities to prevent
pollution and recycle materials. Recycling, household hazardous waste and oil collection, and street
sweeping are examples of some of the procedures that promote proper handling of materials to help prevent
pollution.
The table below summarizes the BMPs to be implemented and maintained during the remainder of the
permit under the pollution prevention and good housekeeping for municipal operations measure. Text
sections that follow the table further explain the BMPs intended to meet this requirement.
Table 7-7: BMP Summary Table for Pollution Prevention/Good Housekeeping for Municipal
Operations$
BMP
Measurable Goals
Frequency
Responsible
Position
(a) Inventory of
Maintain an inventory of municipal
EP&C Analyst
municipal
facilities and operations owned and
Municipal facilities
(Investigations and
facilities and
operated by the permittee that have
inventory: ongoing
Inspections)
operations
been determined by the permitteeto
have significant potential for generating
Municipally- owned
SCM Maintenance
polluted stormwater runoff. Also
SCMs inventory:
Program
maintain an inventory of municipally
ongoing
Coordinator
SCM inventory, see section
7.6
owned structural SCMs.
(b) Inspection and
Implement an inspection and
EP&C Analyst
maintenance
maintenance program for facilities and
Facility inspections:
(Investigations and
program for
operations owned and operated by the
ongoing
Inspections)
municipal
facilities and
permittee for facilities and operations
Pollution Prevention
operations
owned and operated b the Cityof
p y
Teams under
Durham for potential sources of
Facility Maintenance:
supervision of
polluted runoff, including stormwater
ongoing
facility
controls and conveyance systems. The
inspection program shall evaluate
Superintendent(s)
SCM Inspection and Maintenance, see
pollutant sources, document
deficiencies, plan corrective actions,
section 7.6.5
implement appropriate controls, and
document the accomplishment of
City -owned stormwater
y
Pollution Prevention
corrective actions. The maintenance
conveyance systems
Teams under
program shall include maintenance
at facilities
supervision of
8 The letters in the left hand column of this table reference the associated table of BMPS for the Pollution Prevention and Good
Housekeeping for Municipal Operations in the City's NPDES Permit NCS000249. This table starts on Part II, page 8 of the permit.
7-46
Submitted 11/18/2020
Table 7-7: BMP Summary Table for Pollution Prevention/Good Housekeeping for Municipal
Operations$
BMP
Measurable Goals
Frequency
Responsible
Position
activities and procedures aimed at
facility
preventing or reducing pollutants
Superintendent(s)
generated from municipal facilities and
Other City -owned
operations.
stormwater
Stormwater
conveyance systems
Maintenance
(e.g. associated with
Supervisor
streets & parks)
Maintain and implement Site Pollution
Prevention Plans for municipal facilities
Pollution Prevention
(c) Site Pollution
owned and operated by the permittee that
Teams with
Prevention Plans
have been determined by the permittee to
Ongoing
technical assistance
for municipal
have significant potential for generating
from EP&C Analyst
facilities.
polluted stormwater runoff that has the
(Investigations and
goal of preventing or reducing pollutant
Inspections)
runoff.
Facility spill response
SPPPs reviewed by
procedures are
EP&C Analyst
Maintain spill response procedures for
included in SPPPs
(Investigations and
(d) Spill Response
municipal facilities and operations
Inspections)
Procedures for
owned and operated by the permittee
Spill procedures in
City:
municipal
that have been determined b Y the
facilities and
permittee to have significant potential
place for sewage
Superintendent,
operations.
for generating polluted stormwater
discharges from City
Water and Sewer
runoff.
and County collection
Maintenance;
County: Utility
systems.
Division Manager
Describe measures that prevent or
City fleet vehicles
minimize contamination of the
(cars and light trucks)
(e) Prevent or
stormwater runoff from all areas used
are directed to
Fleet Management
Minimize
for vehicle and equipment cleaning,
commercial car wash
Contamination of
including fire stations that have more
facilities under
Stormwater
than three fire trucks and ambulances.
contract to the City.
Runoff from all
Perform all cleaning operations indoors,
areas used for
cover the cleaning operations, ensure
All city emergency
Vehicle and
wash water drains to the sanitary sewer
vehicles are washed
EP&C Analyst
Equipment
Cleaning
system, collect wash water and
where wash water can
(Investigations and
stormwater run-on from the cleaning
be directed to the
Inspections)
area and provide treatment or recycling,
sanitary sewer or to
or other equivalent measures. If
vegetated areas.
7-47
Submitted 11/18/2020
Table 7-7: BMP Summary Table for Pollution Prevention/Good Housekeeping for Municipal
Operations$
BMP
Measurable Goals
Frequency
Responsible
Position
sanitary sewer is not available to the
facility and cleaning operations take
Vehicle wash water
General Services
place outdoors, wash water shall drain
management options
Project Manager,
to an SCM for treatment, or else the
at Fire Stations are
Fire Department
cleaning operations shall take place on
evaluated during
Management
or drain directly to grassed or graveled
renovation planning
areas to prevent point source
discharges of the wash water into the
storm drains or surface waters.
Where cleaning operations cannot be
performed as described above and
when operations are performed in the
vicinity of a storm drainage collection
Cleaning of heavy
system, the drain is to be covered with
trucks and heavy
a portable drain cover during cleaning
equipment takes place
Industrial Permittee,
activities. Any excess standing water
at constructed wash
shall be removed and properly handled
facilities which are
see
prior to removing the drain cover.
covered under NPDES
Appendix
industrial stormwater
permits
Facilities that have three or fewer fire
trucks and ambulances should attempt
to comply with the above requirements;
however, those that cannot comply with
these requirements due to existing
limitations shall incorporate structural
measures during facility renovation to
the extent practicable.
(f) Streets, roads,
The permittee shall implement BMPs to
Assistant Public
and public
reduce polluted stormwater runoff from
Completed
Works Director for
parking lots
maintenance
municipally -owned streets, roads, and
(review and update
Operations, Street
public parking lots within the corporate
annually)
Cleaning Supervisor,
limits.
EP&C Analyst
(g) Inspection and
The permittee shall maintain and
Field assessment of
Stormwater
Maintenance
implement an inspection and
City owned SCMs:
Development
(I&M) for
maintenance program for stormwater
ongoing
Review Manager
Submitted 1111812020
Table 7-7: BMP Summary Table for Pollution Prevention/Good Housekeeping for Municipal
Operations$
BMP
Measurable Goals
Frequency
Responsible
Position
municipally-
control measures (SCMs) owned and
Conduct routine
owned or
operated by the municipality and the
maintenance required
Department
maintained
municipal storm sewer system
by the Stormwater
responsible for the
stormwater
control measures
(including catch basins, the conveyance
Development Review
SCM
(SCMs) and the
system, and SCMs).
field assessment
storm sewer
Stormwater
system.
Maintenance
Inspection of the
Supervisor &
municipal stormwater
Stormwater
system
Infrastructure
Manager
Maintenance of the
Stormwater
municipal stormwater
Maintenance
system
Supervisor
(h) Staff training
Maintain and implement a training plan
Pollution Prevention
that indicates when, how often, and
Coordinator, EP&C
who is required to be trained and what
Analyst, Site
they are to be trained on.
Pollution Prevention
Teams
7.7.1 Operation and Maintenance Program
The City of Durham will continue to implement an operations and maintenance program for the municipal
stormwater system. This includes City streets, roads, and parking lots; municipal operations; and municipal
facilities owned and operated by the City deemed to have significant potential for stormwater contamination.
Operation and maintenance of the MS4 is discussed below in section 7.7(h). Operation and maintenance of
streets, roads, and parking lots is addressed in section 7.7(g).
Facilities included in the inventory developed for section 7.7(c) are required to develop and maintain a site
Stormwater Pollution Prevention Plan (SPPP) under section 7.7(b). Stormwater pollutants handled,
generated, and risk of runoff contamination is site -specific. Appropriate operation and maintenance
depends upon the site configuration, the pollutants that may be encountered, and other factors. Each site's
SPPP is the best reference for in-depth understanding of site operations, pollution potential, and Best
Management Practices implemented..
The operation and maintenance activities carried out have the ultimate goal of preventing or reducing
pollutant runoff
7-49
Submitted 1111812020
7.7.2 Site Stormwater Pollution Prevention Plan (SPPP) for Municipal Facilities
The 34 facilities owned or operated by the City have been classified by our inspections staff into special
action, high, medium, low, and lowest priority based on site -specific risk assessment and history of
regulatory compliance. Priorities are reassessed on an ongoing basis. Further explanation of facility category
assignment and occasional reassignment may be found in the City's Industrial Stormwater Inspections
Program Standard Operating Procedures document
SPPPs have been developed for all municipal facilities that are subject to NPDES Industrial Stormwater
permitting. Twenty-three of 29 other municipal facilities presenting risk of stormwater contamination have
developed SPPPs. The remainder are in development.
New or newly identified facilities will be inspected within 6 months. Based on the initial inspection each new
facility with be assessed regarding whether the facility has potential for generating polluted runoff, and the
facility will be categorized as appropriate. SPPPs will be completed for new or newly identified facilities that
have potential for generating polluted runoff. Simplified SPPPs will be developed for facilities in the Lowest
category.
7-50
Submitted 1111812020
7.7.3 Inspection and Evaluation of Municipal Facilities
Inventory
The City maintains an Industrial Inspections relational database to track facilities, their status and priority,
inspection results, and correspondence, including notices and penalties. The database includes both
municipal and private facilities. It includes NPDES-permitted and non -regulated facilities. The database
includes supplemental information such as industrial facilities that are now closed, and industrial facilities
located in Durham County that are outside city limits. Data is regularly obtained from various sources to
update the database.
The database designates municipal facilities determined by the City to have potential for generating
pollutants that can contaminate runoff in various inspection priority categories: Special Action, High,
Medium, Low, and Lowest. Each priority level has a corresponding inspection frequency: quarterly, thrice
annually, twice annually, annually, and once per three years. Category assignments are based on facility
compliance history, the industrial inspector's experience, and our assessment of the facility's risk of
generating runoff pollutants.
The intent of this system is to focus staff resources on facilities that need assistance. As facilities develop a
track record of self -inspection, compliance and self -management, the facility will likely change to a category
requiring less frequent inspections. Conversely, if circumstances result in a decline in performance, the
facility's category will be changed to increase inspection frequency. The system allows automation of
inspection prioritization, and facilitates distribution of inspection workload among several staff members to
facilitate succession planning.
With the exception of Special Action, the municipal categories are separate from the private categories and
have different inspection frequencies. Generally speaking, municipal facilities are inspected more frequently
than private facilities.
Further explanation of facility category assignment and occasional reassignment may be found in the City's
Industrial Stormwater Inspections Program Standard Operating Procedures document
Present categorization and inspection frequencies are provided in Table 7-8. The majority of municipal
facilities are assigned to the Medium and Lowest categories based on facility compliance history, inspector
experience, and site -specific risk factors. The range of categories shown in the table results in a system
flexible enough to accommodate fluctuations in risk and the need for increased or decreased inspection
frequency, as well as providing appropriate categories for new operations that may be different in risk.
7-51
Submitted 11/18/2020
Table 7-8 Municipal facility inspection priority categories, with risk of stormwater pollution, inspection
frequency, and current number of facilities in category.
Category 4
Medium
Lowest
Special Action
High Priority
Low Priority
Priority
Priority
Risk of
Stormwater
Highest
High
Medium
Low
Lowest
Pollution
Inspection
Quarterly
3x per year
2x per year
1x per year
1x every 3
Frequency
years
2019
classification
1
0
13
1
19
of facilities
A facility's category may change over time based on fluctuations in risk and the need for increased or
decreased inspection frequency.
Inspection
Our Inspections Database automates generation of lists of private and municipal facilities due for inspection
to facilitate scheduling, based on risk category and inspection frequency.
The City has six facilities with NPDES Industrial Stormwater permits. As required by permit, each facility has
a facility SPPP and facility Pollution Prevention Team. Water Quality inspectors and the Pollution Prevention
Coordinator provide initial training to the Pollution Prevent Team. The Pollution Prevention Team is
responsible for conducting inspections required in the permit and SPPP, and for maintaining and updating
the SPPP. The Water Quality inspectors conduct additional inspections of these NPDES permitted facilities
together with members of the team in accordance with the inspection priority system discussed below. The
Pollution Prevention Coordinator (Water Quality Unit) provides annual training on Pollution Prevention to
facility staff. The facility Pollution Prevention Team is responsible for identifying site specific issues,
including issues that may require more specific training. The facility Pollution Prevention Team is
responsible for making sure staff are trained on site specific issues, either by conducting that training
themselves, or by providing photos and other information so that the Pollution Prevention Team can cover
the issue together with the general training.
Non-NPDES municipal facilities are inspected by Water Quality inspectors. Routine inspection will be in
accordance with a priority system established based on experience inspecting these city facilities, including,
as applicable, reviewing availability and implementation of the Stormwater Pollution Prevention Plan;
monitoring results; and record keeping on training, self- inspections and subsequent follow-up actions.
The Industrial Stormwater Inspections Standard Operating Procedures provide guidance for conducting
inspection of both private facilities and municipal facilities. Inspections of municipal facilities are always
conducted with one or more members of the facility's stormwater pollution prevention team. Inspections
focus on identification of stormwater pollution issues and development of strategies for preventing or
addressing compliance issues.
For municipal industrial activities, inspections routinely include review of pertinent documentation:
• Stormwater Pollution Prevention Plan
• Permit -required elements
• Annual updates, changes, and amendments
7-52
Submitted 1111812020
• Qualitative and Quantitative Runoff Monitoring Data (for NPDES permitted activities)
• Annual employee training records
• Semi-annual self -inspection records
• Non-stormwater discharge and spill incident history
• Annual self -review of program effectiveness
Inspection reports, automatically generated by the Stormwater Inspections Database, are routinely provided
to facility personnel upon completion of inspections, along with site photographs and compliance assistance.
In addition to site inspection results, the inspectors routinely send e-mail or inter -office correspondence to
remind facility pollution prevention team leaders of monitoring schedules, deadlines, reissued General
permits, etc.
Facilities reported as non -compliant with stormwater rules or having foreseeable risk of stormwater pollution
that cannot be fully resolved during an inspection are all given a follow-up inspection to insure corrective or
preventative actions are taken.
Annual reports will focus on inspections conducted by the Stormwater inspections staff.
7.7.4 Spill Response Procedures for Municipal Facilities and Operations
The City -County Local Emergency Planning Committee, in coordination with Durham City -County Emergency
Management, has developed a vetted, comprehensive list of contractor resources to cover a wide variety of
environmental emergencies. The City Stormwater & GIS Services division furnishes this list to parties
(municipal and private) in need of such services when non-stormwater discharges threaten the drainage
system and/or surface waters.
Each City of Durham municipal operation that has developed a SPPP has established site -specific BMPs to
address spill prevention, spill response, and spill kits. Spill kits generally contain a combination of granular
absorbent, oil -absorbent pads, and absorbent spill control booms. In addition to facility general use kits, spill
kits are located and routine spill cleanup patrols are implemented at the City's two fueling islands. Heavy
duty vehicles having hydraulic systems that are operated by Solid Waste and Water Management also carry
spill kits and have backup assistance for spill containment. Heavy duty vehicles in Public Works, General
Services, and Water Management carry spill kits or granular absorbent to capture spills. For other mobile
operations, the City's HazMat trucks and fire trucks carry spill kits and the City's Stormwater Pollution
Control Ordinance requires private wrecker trucks to carry spill kits.
The City and County each operate publicly owned sanitary sewer systems with the City of Durham.
Stormwater & GIS Services responds to requests for assistance on sanitary sewer overflows from each of
these operators. Because the City is located along a ridgeline between two river basins, most streams are
small, third order or less. When there is a discharge to one of these streams it is typical practice for the
utility to install a pump to remove contaminated water and return it to the collection system. Stormwater &
GIS Services assists in such operations, using field ammonia test kits to detect sewage, allowing effective
placement of pumps to capture a greater volume of contaminated water than is possible using visual
indicators.
The City's Water Management Department has been highly effective in reducing both the frequency of
sanitary sewer discharges and the total volume discharged.
7-53
Submitted 1111812020
7.7.5 Prevent or Minimize Contamination of Stormwater Runoff from all areas used for vehicle and
equipment cleaning
City cars and light duty trucks are brought to a third -party commercial car wash. For more demanding
cleaning, the City has two wash pits at the Public Works Operations Center, a bay at the Solid Waste Truck
Wash, a bay for busses at the Durham Area Transit Authority maintenance center, and an indoor wash area
at the Parks and Recreation Operations and Maintenance facility.
Emergency vehicles must stay close to their assigned service area to meet response time goals. The City Fire
Department continues to comply with the City's MS4 NPDES permit rule governing the washing of emergency
vehicles. Stormwater & GIS Services and the Fire Department continue to investigate a renovation plan to
allow vehicle washing at all Fire Stations. Until all stations have been retrofitted (if possible), emergency
vehicles may be brought to Stations 1, 3, 4, 5, 6, 7, 9, 13, or 17 for washing. Wastewater from vehicle
washing at those stations is directed into engineered retention areas, grassed areas, or loosely graveled
areas.
7.7.6 Streets, roads, and public parking lot maintenance
The City is continuing to implement the BMPs it has identified. These include street sweeping; removal of
dead animals from streets, roads and highways; litter pick up at key road intersections, bus stop cleaning,
and litter clean-up in the downtown area through partial funding of Downtown Durham, Inc.'s Durham
Ambassadors program. It also includes efforts to address petroleum spills by having clean-up kits readily
available.
Operation and Maintenance (0&M) for city -owned BMPs and city -owned storm sewer system (including catch
basins, the conveyance system, and structural stormwater controls)
Inspection and maintenance responsibilities extend across several work units and several programs. Street
cleaning crews clean street gutters and catch basins tops. The City maintains two Vactor trucks and one
CATV-equipped crew vehicle. One Vactor is generally dedicated to preventative maintenance and the other to
complaint response. A pole camera is also used to inspect pipes.
In a given year, Stormwater Services may supplement city resources by contracting for video inspection
services.
Catch basins commonly used in Durham have combination inlets and are `self-cleaning,' meaning that they
do not have sumps designed to catch and retain material. Street cleaning removes material that collects on
the inlet grate. Vactor trucks are used to remove sediment that accumulates in pipes and other conveyance
structures.
Stormwater quality personnel inspect outfalls (most of which are private) and screen any dry weather flows
for pollutants.
Inspection of privately owned structural BMPs and inspection and maintenance of city -owned structural
BMPs are addressed in the Post -Construction section of the Stormwater Management Plan, Section 7.6.
7.7.7 Staff Training
Municipal employee training has evolved over many years. Initially, this focused on pollution prevention
training of staff at permitted and high -risk facilities. Initially training was conducted by the Industrial
inspector. Once facilities developed Stormwater Pollution Prevention Teams those teams were expected to
provide training to incoming team members.
The Pollution Prevention Coordinator is an experienced educator and trainer. The City maintains a library of
training videos to support this position in providing training on:
7-54
Submitted 1111812020
• General site pollution prevention
• Spill response and reporting
• Illicit discharge identification and reporting
The Pollution Prevention Coordinator uses video resources, PowerPoint presentations, handout and written
guidance materials to cover issues for a given audience. Training sessions include pre -training and post -
training quizzes to document learning. Once a workgroup attains proficiency on pre -training quizzes, training
frequency can be modified to every other year.
A self -paced presentation has been developed for orientation of new employees, with quizzes to document
learning.
The Pollution Prevention Coordinator maintains an inventory of work groups and contract operators
scheduled to be trained and the specific areas to cover in training. The Pollution Prevention Coordinator also
maintains records indicating generally the topics covered in each training session, sign -in sheets, and copies
of pre -training quiz and post -training quizzes.
The Pollution Prevention Coordinator began conducting annual training for designated work groups in FY
2014. A goal of 80% correct answers on testing demonstrates adequate knowledge. Table 7-9 summarizes
the overall effectiveness of the training through most of FY2018.
Table 7-9 Overall Results of Staff Testing
Fiscal Year
Percentage of Work Groups
Scoring 80% or Higher
2014
0%
2015
48%
2016
78%
2017
100%
2018
93%
Training is scheduled around availability of each work group within a fiscal year rather than on a fixed
schedule. Work groups designated as High Priority will be trained at least once each fiscal year. Work groups
designated as Medium and Low Priority will be trained every two years, unless a condition is noted (informal
observation, formal inspection, or otherwise) that warrants additional training. Group designations will be
determined by the nature of the work that is done by the group and by the scores on pre- and post-tests
given during the group's most recent training. If a specific group does not answer at least 80% of pre- and
post-test questions correctly, they will be flagged for annual training. New employee training in each group
will continue to happen on a rolling basis as new employees are hired.
City facilities with NPDES permits have pollution prevention teams. Identification of common or reoccurring
issues by the facility's Pollution Prevention Team may indicate the need for training on specific topics. The
Pollution Prevention Team is expected to conduct this training or else to provide photos and other
information to the Pollution Prevention Coordinator so that it can be covered in annual or biennial training.
7.7.8 Facilities
Typical municipal activities, operations, and facilities are outlined in Appendix J. This document provides an
inventory of facilities and operations owned and/or operated by the City of Durham with the potential for
generating polluted stormwater runoff. Appendix J lists the five City operated facilities with NPDES Industrial
Stormwater Permits and a sixth privately operated facility on City property with permit coverage. Additional
priority facilities have developed and are implementing Stormwater Pollution Prevention Plans (SPPPs).
7-55
Submitted 1111812020
7.8 Program to Monitor and Control Pollutants to Municipal Systems
The target facilities of the program designed to monitor and control pollutants in storm water discharges to
the permittee's MS4 are: hazardous waste treatment, storage, disposal facilities; recovery facilities;
industrial facilities subject to Section 313 of Title III of the Superfund Amendments and Reauthorization Act
of 1986 (SARA); and industrial facilities that the Permittee determines are contributing or have a potential to
contribute a substantial pollutant load to the municipal storm sewer system.
The City of Durham has developed and implemented an industrial facilities inspections program during
previous permit terms. The City places particular emphasis on inspecting facilities that report releases
(Section 313 of Title III of SARA) and that do not have NPDES permits. The City typically also identifies a
ubiquitous business sector on which effort is focused. These have included auto salvage yards and facilities
with numerous inoperable vehicles, mobile auto maintenance operations, and vehicle service facilities.
The City's Stormwater Pollution Control Ordinance (Durham City Code Chapter 70, Article V) mandates
certain pollution prevention practices. For example, Section 70-515 includes pollution prevention
requirements for automotive activities, requiring vehicle maintenance to take place in a covered bay, and
automotive fluids stored outside to be to have secondary containment and to be stored under a covered
area. Section 70-516 requires facilities that have more than ten junk, salvage or unlicensed vehicles to
develop and implement a SPPP. Section 70-517 provides requirements for storage of hazardous
substances.
The table below summarizes the BMPs to be implemented and maintained during the remainder of the
permit to meet requirements to monitor and control pollutants entering the municipal system.
7-56
Submitted 1111812020
Table 7-10: BMP Summary Table for Monitoring and Control of Pollutants Entering the MS49
BMP
Measurable Goals
Frequency
Responsible
Position
Maintain a database inventory of permitted
hazardous waste treatment, disposal and
(a) Maintain an
recovery facilities, industrial facilities that are
See text
Inventory of
subject to Section 313 of Title II of the Superfund
below for
EP&C Analyst,
Amendments and Reauthorization Act of 1986
Stormwater
Industrial
(SARA), and industrial facilities identified with an
inventory
Inspections staff
Facilities
industrial activity permitted under 40 CFR
maintenance
122.26 that discharge storm water to the
permittee's MS4.
Monthly to
Review and revise inspection priorities.
Annually,
EP&C Analyst,
(b) Inspection
Program
Periodically review and revise inspection
depending
upon
Stormwater
procedures.
inspection
Inspections staff
results
For permitted facilities, the municipality shall
establish procedures for reporting deficiencies
and non-compliance to the permitting agency.
Where compliance with an existing industrial
stormwater permit does not result in adequate
control of pollutants to the MS4, the municipality
(c) Evaluate
will recommend and document the need for
Industrial
permit modifications or additions to the permit
See Table 7-
Facilities
issuing authority.
12 for
EP&C Analyst,
Stormwater
The ermittee is required to evaluate control
p q
discharging
inspection
insp
Inspections staff
stormwater to
measures implemented at permitted hazardous
priorities
the City's MS4
waste treatment, disposal, and recovery facilities,
industrial facilities that are subject to Section
313 of Title II of SARA (TRI), industrial facilities
identified with an industrial activity permitted to
discharge storm water to the permittee's MS4, or
as identified as an illicit discharge under the
IDDE program.
9 The letters in the left hand column of this table reference the associated table of BMPS for the Program to Monitor and Evaluate Storm Water
Discharges to Municipal Systems in the City's NPDES Permit NCS000249. This table starts on Part II, page 10 of the permit.
7-57
Submitted 1111812020
Table 7-10: BMP Summary Table for Monitoring and Control of Pollutants Entering the MS49
BMP
Measurable Goals
Frequency
Responsible
Position
For the purposes of this permit, industrial
activities shall mean all permitted industrial
activities as defined in 40 CFR 122.26. For the
purpose of this permit, the Permittee is
authorized to inspect the permitted hazardous
waste treatment, disposal, and recovery facilities
as an authorized representative of the Director.
7.8.1 Inventory of Industrial Sites
The Inspections Program maintains a Microsoft Access database to store general information, inspection
results, compliance status, and ordinance enforcement details for each private and municipal industrial
facility within the City limits. The database is used to track and schedule inspections. This database has
been regularly revised and updated to improve utility, and includes coordinate data collected in the field with
handheld GPS devices or determined using aerial imagery and GIS for more than 90% of the facilities.
7.8.2 Inventory Maintenance
The City's inventory of industrial sites is updated using:
• Semi-annual queries of EPA's Toxic Release Inventory (July and October, corresponding with the EPA's update
schedule) to identify facilities subject to Section 313 of SARA Title III;
• Quarterly lists of all NPDES permitted facilities in Durham County obtained from the Stormwater Permitting Unit
at the NC Division of Energy, Minerals and Land Resources;
• Quarterly queries of EPA's RCRAInfo search tool to identify permitted hazardous waste treatment, disposal,
storage, and recovery facilities;
• Staff field observations of new and un-inventoried facilities; and
• Routine queries of the City of Durham Stormwater Services Water Quality Investigation database (IDDE
program records) to identify facilities associated with illicit discharges.
As of October 2019, there were no RCRA Treatment, Storage and Disposal Facilities (TSDF) facilities located
within City limits.
Table 7.11 Inventory of Industrial and Light Industrial Facilities
As of October 2018.
Type of Facility Number inside City
Limits*
Permitted hazardous waste treatment, disposal and 0
recovery facilities
Facilities that reported releases under section 313 of Title III
of the Superfund Amendments and Reauthorization Act of 7
1986 (SARA) [toxic release inventory, (TRI)]
7-58
Submitted 1111812020
Facilities with an industrial activity permitted in accordance
with 40 CFR 122.26 to discharge stormwater to the 32
permittee's MS4
Facilities with No Exposure Certification 27
Non-NPDES permitted facilities with industrial or light
industrial activities similar to those permitted under 40 CFR 395
122.26
Totals 454 * *
*Our database additionally tracks a number of NPDES Stormwater-permitted and non -permitted industrial
facilities outside of the City Limits.
** Adding this column down results in a sum of 461. However, of the 7 TRI-listed facilities, 5 additionally
have NPDES Stormwater Permits, 1 has a No Exposure Certification, and 1 is counted as Non-NPDES. To
display the accurate sum, we have subtracted those 7 double -counted facilities to arrive at an accurate total
of 454.
7.8.3 Inspection Procedures
The City follows written procedures in conducting the inspection program. As the inspection program
continues to evolve, the City will update and maintain these procedures based on experience.
To guide inspection of the expanded inventory the city has been refining a priority system to guide
inspections. Under the current scheme created in 2014, facility inspection priority and frequency is based on
risk and compliance history. Every facility is assigned and inspected according to a priority level reflecting a
combination of risk of stormwater pollution and history of compliance with stormwater regulations.
Facilities found to be in compliance on a routine inspection would qualify to be inspected less frequently,
while non -compliant facilities may qualify for more frequent inspection. Facilities that have not yet been
inspected and that are (or appear to be) engaged in automotive service and these have been assigned to the
medium priority. Over time, facilities with good compliance records will move to lower priority categories,
freeing up staff to conduct inspection of facilities that have not yet been inspected. The sorting that will
occur over time will focus available staff resources and guidance on those facilities that most need it.
Compliance on a follow-up inspection does not change the facility priority level. While routine inspections are
comprehensive, follow-up inspections are used to track progress on a limited number of issues, to assess
the need for additional corrective action/enforcement, and to document compliance.
This system allows us to focus on those facilities most in need of oversight, corrective action, or both.
Private industrial and light industrial facilities are inspected according to the following hierarchy:
1. Facilities requiring follow-up inspection - corrective actions needed
2. Special Action Plan (SAP) - one facility designated for this extra attention
3. High Priority - high risk and/or recent history of non-compliance, annual inspection
Facilities reporting releases on the EPA TRI Facility Release Report and TSDFs remain high priority regardless
of compliance history
4. Medium Priority - lower risk, inspect biennially
5. Low Priority - lowest risk, inspect every 3 years
6. No Exposure - NCDEQ has issued No Exposure Certification, inspect every 5 years
7-59
Submitted 1111812020
7. No Inspection Needed - no storage of pollutants or pollutant -generating activities
A flow chart for the inspection priority scheme is provided in Figure 7-6. Additional discussion and details are
provided in the revised Inspections Program Standard Operation Procedures.
The stormwater inspections database tracks a facility's priority rank and automatically assigns the proper
inspection frequency. Database reports that have been automated include one to generate a current listing
of facilities due for inspection based on priority, inspection frequency, and time since most recent
inspection. Separate inspection -due reports may be generated for private facilities and for municipal
facilities.
Table 7-12 below summarizes the inspection frequency goal for each priority category. Facilities are
occasionally elevated or demoted in priority according to additional characteristics and observations made
by Stormwater Inspectors or supervising Water Quality Specialist. Annual report will typically include updated
versions of this table when there has been significant change.
7-60
Submitted 11/18/2020
Table 7-12. Description of facility inspection priority levels, with 2018 category totals.
Category
Special
High Priority
Medium
Low Priority
No Exposure
No
No Inspection
Action
Priority
Risk of
Stormwater
Highest
High
Medium
Low
Lowest
None
Pollution
Inspection
Frequency
Quarterly
1x per year
1x per 2 years
1x per 3 years
1x per 5 years
Not inspected
Goal
Number of
0
72
164
101
21
96
facilities'
'As of September 2019
Figure 7-6. Inspections priority flowchart showing the inspection frequency and promotion/demotion of
facilities based on routine inspection results.
High:
Inspect Annually
Compliance?
What is private facility priority
level?
Medium:
Inspect every
2 years
Compliance?
followu I jDwn.tetj I I Coand ct I I
Demote to
follow-up Medium follow-up Low
enforce Priority enforce Priority
Promote to
High
Priority
Low:
Inspect every
3 years
Compliance?
No—LYes
Conduct
follow-up Remain
and Low
enforce Priority
Promote to Steps to
Medium become
Prigrity Exposure?
No Exposure:
lnspeci every
5 years
7
<ompl>
laYeS
Conduct Remain
follow-up No
and Exposure
enforce
Promote to
Low
Priority
Category includes
All facilities not yet industrial sites certified as
All TRI facilities remain inspected begin at Remain Low Demote to NCGNE by the State and
high priority, regardless of No
Medium Priority by Priority non -certified light
compliance history. default. Exposure industrial sites with no
exposure.
7-61
Submitted 1111812020
7.9 Water Quality Assessment and Monitoring
This Water Quality Monitoring & Assessment Plan was prepared to comply with Part II, Section I of the City of
Durham's National Pollution Discharge Elimination System (NPDES) Permit for stormwater discharges issued
Octoberl0, 2018. The objective of this section of the permit is to "evaluate the impacts of MS4 discharges
on water quality." Additional requirements in the Water Quality Assessment and Monitoring Plan are as
follows:
Table 7-14: BMP Summary Table for Monitoring and Control of Pollutants Entering the MS4
BMP
Measurable Goals
Frequency
Responsible
Position
(a) Water Quality
Maintain a Water Quality Assessment and
Ongoing
Water Quality
Assessment and
Monitoring Plan. The Plan shall include a
Manager
Monitoring Plan
schedule for implementing the proposed
assessment and monitoring activities.
(b) Water Quality
Maintain and implement the Water Quality
Ongoing
Water Quality
Monitoring
Assessment and Monitoring Plan submitted to
Specialist
DEMLR.
(Assessment and
Monitoring)
Requirements to establish an assessment and monitoring program were included in the permit effective July
1, 2007. The subsequent permit effective March 1, 2013 included requirements to maintain and implement
the water quality assessment and monitoring plan. The current permit continues these requirements.
The current permit requirements logically follow the establishment of an assessment and monitoring
program, as described in the first permits. The subsequent permit placed additional emphasis on starting an
assessment and monitoring plan, and included specific timelines.
This Water Quality Assessment & Monitoring Plan connects the pollution prevention activities in the NPDES
permit to assessment and monitoring. Quality Assurance Project Plans (QAPPs), Standard Operating
Procedures (SOPs), and other internal guidance documents are used to document the details of the
program.
7.9.1 Assessments and Monitoring under Previous Permits
The City of Durham monitoring program has evolved since the 1990s. Per permit requirements, initial
monitoring was designed to generate pollutant loading rates by land use and to evaluate outfalls located
throughout the City. Subsequent monitoring has been designed toward characterizing stream conditions,
including storm events. Ad -hoc monitoring was performed until 2003. In 2003 a quarterly, fixed -interval
ambient chemistry monitoring program was implemented. In 2004 a monthly, fixed -interval ambient
chemistry monitoring program began. An unstructured monitoring program continued for benthic
macro invertebrates until approximately 2007. Special studies have been conducted to support TMDL
development when needed. These include the bacteria source tracking project [2003-2004] and intensive
fecal coliform monitoring. Wet weather monitoring of Stormwater Control Measures (SCMs) was performed
cooperatively with local universities.
Initial monitoring for pollutant loading rates was reported to NC Department of Environmental Quality
(formerly the Department of Environment and Natural Resources). As the monitoring program began to
evolve, qualitative assessments of chemistry and benthic macroinvertebrate monitoring data were
performed. Additional quantitative assessments have been performed in more recent years. As the
7-62
Submitted 1111812020
assessment methodology is modified, the monitoring to support the assessment may also be modified. All of
these changes are reflected in SOPs and QAPPs.
7-63
Submitted 1111812020
7.9.2 Assessment
Stormwater & GIS Services has performed several data evaluations and assessments in the past. These
have been reported in previous annual NPDES reports and summarized in the State of Our Streams report
since 2004. EPA guidance on data quality assessments suggests a review of the objectives and sampling
design and preliminary data review as the first two steps of a statistical data review (EPA 2006). At the
center of all data assessment and collection goals is a commitment to quality assurance. A review of
assessment and monitoring goals was conducted to determine if new goals have been identified. The
resulting program goals are as follows:
Core goals
• to identify illicit discharges to area streams
• to identify pollution problem areas within the City
• to assess compliance with state water quality programs, including Total Maximum Daily Loads (TMDLs), water
quality standards, and nutrient management strategies
Supplemental goals
• to identify overall trends to water quality
• to evaluate the performance of Stormwater Control Measures (SCMs)
• to determine potential pollution removal credits
• to assess the overall quality of streams within the City of Durham, and
• to evaluate the water quality impacts of urban stormwater on area streams.
The program goals have been separated into core and supplemental goals. Core goals have not changed
from past years; these goals have been assessed regularly since 2004. Other supplemental goals are
assessed depending on the resources available and priority. Therefore, these goals may not be assessed
regularly. The supplemental goal list provides Stormwater & GIS Services a reminder of alternative goals that
may be fulfilled with short-term adaptations of the assessment and monitoring plan.
Each of the assessments of goals is described generally below. Depending upon the goal and resources
available, the level of detail may be reduced in order to accommodate some assessment rather than omit
the assessment altogether. If and when resources are restored, efforts may be made to retroactively fill in
assessments. However, if monitoring data were not collected, retroactive assessments may not be possible.
Descriptions of the assessment are contained within SOPs, including those for outfall screening (Stormwater
& GIS Services 2013a), investigations (Stormwater & GIS Services 2013c), and inspections (Stormwater &
GIS Services 2013d).
Each of the program goals is listed with narrative descriptions of the types of assessments that may be
performed to meet the goal. The types of assessments may be modified to be more or less complex
depending upon many factors, including resources available for the assessment, software availability, and
monitoring data. Core goals are listed first, followed by supplemental goals.
Goal: To identify illicit discharges to area streams
Type(s) of Assessment: Assessments performed to identify potential illicit discharges are typically performed
in -situ immediately following the collection of some measurement. The measurements are compared
against a benchmark that may trigger environmental forensics and illicit discharge investigations. If the
benchmark is not exceeded, an investigation is not initiated. These assessments may be performed on any
flowing water in the collection system during dry weather. These assessments may also be performed during
other types of outdoor work activities when the technician has reason to suspect an illicit discharge.
Goal: To identify pollution problem areas within the City of Durham
7-64
Submitted 11/18/2020
Type(s) of Assessment: Two different types of assessments may be performed to identify problem areas
within the City, by geographically analyzing the locations of IDDE investigations and by geographically
analyzing in -stream water quality monitoring data. Each method can be used to highlight areas with
problems, although the types of problems identified are slightly different. Assessing problem areas by
analyzing the locations of investigations highlights areas where pollution prevention activities may be
targeted. Assessing problem areas by analyzing in -stream water quality monitoring data highlights areas
when pollution is reaching the stream, or where hydrology has altered the stream. In these cases, an
investigation may be needed to identify the source of the pollution problem, or further scientific study may
be needed to diagnose hydrologic or structural problems.
Goal: To assess compliance with state water quality programs, including TMDLs and nutrient management
strategies
Type(s) of Assessment: All assessments associated with this goal involve comparing conditions monitored in
Durham to state and federal water quality program targets. In most cases, these assessments involve a
direct comparison of water quality monitoring data to a state water quality standard for a specific parameter
(e.g., dissolved oxygen). In some cases, where the state water quality standard is less informative, the
comparison may be performed against federal ambient water quality criteria. This is the case with several
metals. Lastly, goals for TMDLs and nutrient management strategies are often expressed in terms of mass
per time. In these cases, additional calculations are needed before the comparisons can be performed.
Goal: To evaluate the performance of SCMs
Type(s) of Assessment: Performance assessments of SCMs may include determining pollutant removal
efficiencies or evaluating changes to discharge hydrographs, depending upon the goal of the specific study
or site. SCM performance may be evaluated at industrial, commercial, or residential locations. The
parameters evaluated will vary based on the land use draining to the SCM, although most will include
nutrients because of the nutrient management strategies. These types of assessments are typically
performed using monitoring data over multiple seasons.
Goal: To determine pollution removal credits
Type(s) of Assessment: Determining pollution removal credits is a relatively new goal initiated shortly after
the adoption of the Falls Lake rules. However, this goal can apply to any area with a TMDL. These types of
assessments all intend to quantify the amount of pollution that is removed from surface water. All programs
in Stormwater & GIS Services may be evaluated to determine pollution removal credits, including Illicit
discharge elimination and low impact development retrofits.
Goal: To identify overall water quality trends
Type(s) of Assessment: Accountability is central to this goal, which includes a desire that water quality
improve over time. Assessments of overall water quality trends may be as simple as graphical
representations and professional judgments to determine if water quality is getting better, worse, or staying
about the same. Assessments may also be more complicated, using statistical methods that attach a level of
confidence with statements about trends. These assessments may be performed on individual monitored
parameters, or on a composite parameter such as the Durham Water Quality Index.
Goal: To evaluate the water quality impacts of urban stormwater on area streams
Type(s) of Assessment: All of the previous assessments contribute to this goal. The way the assessment is
analyzed is slightly different when considering widespread impacts of urban Stormwater. For example,
quantifying the pollutants discharged during specific types of activities, such as concentrated washing of
vehicles or maintenance of AC units, characterize what may be washed into the stormwater collection
system and ultimately area creeks when these activities do not comply with local ordinances.
7-65
Submitted 1111812020
7.9.3 Monitoring Programs
The City of Durham has four overlapping monitoring programs. Each program generates monitoring data for
different assessment purposes. The ambient monitoring program generates monitoring data that describe
the condition of streams and rivers in the City of Durham. This program generates data that can be used to
assess changes over time as well as to identify specific changes in a watershed. Effluent monitoring from a
stormwater perspective, versus a wastewater perspective, is associated with any discharge to the municipal
separate storm sewer system (MS4) of a substance that is not water. Effluent monitoring conducted by
Stormwater & GIS Services is usually in response to a suspected or confirmed discharge of a substance that
is not water. Stormwater control measures (SCMs) or best management practices (BMPs) are structural or
non-structural practices that are put into the landscape with the intent of controlling non -point source
pollution in runoff. Although many of these practices have estimates of how well they perform in the
landscape, the variation in construction techniques or implementation methods may result in higher or lower
removal of pollution. Stormwater & GIS Services has completed studies of structural SCMs to determine
their effectiveness in the City of Durham landscape. Other monitoring studies are designed and executed as
needed based on City priorities. These other studies are typically short-term and focus on a specific
outcome.
Table 7-15 City of Durham Stormwater & GIS Services Monitoring Goals and Programs
m
m
U)
J
i
a
�
0
� N
U)
(n
Goals
E
t5
U
W
C1
Identify illicit discharges
✓
✓
Identify problem areas
✓
✓
o
Assess compliance with state WQ programs
✓
✓
Overall trends
✓
✓
✓
Evaluate performance of SCMs
✓
✓
F-
Determine pollution removal credits
✓
✓
✓
✓
a
Q
Assess overall quality of City's streams
✓
cn
Evaluate effects of urban SW on City's streams
✓
✓
✓
✓
Quality assurance is a high priority of the City of Durham. Water quality monitoring data has many uses,
including the development of regulations, assessment of conditions, and for enforcement purposes.
Enforcement may be performed by the City, or on the City. A serious commitment to quality is, therefore,
necessary to ensure that monitoring data is of the highest quality and comparable to data collected by state
and federal entities. The Stormwater Service's quality assurance program requires a Quality Assurance
Project Plan (QAPP) that meets EPA requirements (EPA 1996) be developed for each program or project. A
QAPP describes a project's data quality objectives and how the study design will ensure that those data
quality objectives are met through activities related to project management, data generation and acquisition,
project oversight and assessment, and data validation and verification. Other QA efforts include regular split
sampling with contract laboratories and the state water quality laboratory.
Stormwater & GIS Services utilizes an internal planning and assessment process when considering changes
to existing or establishment of different monitoring programs and projects for the coming two -three years.
This allows Stormwater & GIS Services to respond to emerging concerns and issues within the City's
watersheds.
7-66
Submitted 1111812020
7.9.3.1 Ambient Stream Monitoring
The Ambient Stream Monitoring program supports the following assessment goals:
• To identify pollution problem areas within the City
• To assess compliance with State water quality programs, including TMDLs, water quality standards, and
nutrient management strategies
• To determine pollution removal credits
• To identify overall trends to water quality
• To evaluate the water quality impacts of urban stormwater on area streams
• The City's Ambient Stream Monitoring program is comprised of three major components: water chemistry,
aquatic biological communities (benthic macroinvertebrates), and hydrology. These three different types of
monitoring allow the City of Durham not only the opportunity to evaluate streams independently of the
State, but also to verify results obtained by the State.
Similar to the NC Division of Water Resources (DWR) Ambient Monitoring System, Durham's Stormwater &
GIS Services uses a rotating watershed approach, with comprehensive chemical and biological monitoring in
each basin occurring every two years (Table 7-13). The rotating watershed approach was implemented in
calendar year 2011 and allows a wider geographic coverage of monitoring of the City's streams than would
otherwise be possible with current resources. However, a subset of sites are monitored every year for water
chemistry and hydrology due to their use in calculating loading for certain parameters of concern.
Table 7-16. Rotating Monitoring Schedule
Neuse River Basin
Watersheds
Cape Fear River Basin
Watersheds
Odd Years
Ellerbe Creek
Crooked Creek
Panther Creek
Little Creek
Stirrup Iron Creek
New Hope Creek
Even Years
Eno River
Northeast Creek
Lick Creek
Third Fork Creek
Little Lick Creek
Little River
One full monitoring cycle includes the planning, monitoring, summarizing and reporting of monitoring data.
This is generally accomplished in 18 months. Stormwater & GIS Services re-evaluates the monitoring
program near the end of each calendar year. Existing monitoring sites are reviewed to determine if any
should be added or removed, or if anything unusual has occurred at a particular station. New potential
stations may be proposed to evaluate emerging concerns or issues. When all results have been received
from the analytical laboratory, annual summaries for each watershed are generated for each monitoring
program and reported on the Stormwater & GIS Services website. All staff of the Water Quality Unit of
Stormwater & GIS Services work to ensure that scheduled monitoring and reporting is completed.
7-67
Submitted 1111812020
Develop �PLlish State
rrrorrtorirtg MDn itor w nf�r
Ply anrMd resW Streamsreport
Appiaxim-2!efy 19.rnar k! S
Water Chemistry
The ambient chemistry portion of the monitoring program focuses on surface water. Through field or
laboratory analysis of selected parameters, the ambient chemistry program provides brief looks, or
"snapshots," of water quality. These snapshots can be used to identify short and long-term trends and
sources of pollution. Additional information is available in the Ambient Water Chemistry Monitoring Program
Quality Assurance Project Plan (Durham 2014a).
Ambient water chemistry monitoring consists of monthly grab samples for laboratory analysis and
collection of field parameters (e.g., temperature, dissolved oxygen, pH, specific conductance, and
turbidity). using multiparamter field meters. In general, all sites have identical parametric coverage,
though additional parameters may be collected due to site -specific concerns. Monthly sampling dates for
all sites are scheduled during the planning phase, so a wide variety of site conditions (particularly
hydrology) are generally represented each year. All sites within a single watershed are sampled on the
same day whenever possible. .
Benthic Macroinvertebrate Communitv Assessments
The City of Durham uses benthic macroinvertebrate monitoring as a way of assessing the ability of the City's
streams to support aquatic life. Benthic macroinvertebrates are found in almost all aquatic environments,
are less mobile than many other groups of organisms (e.g., fish), and are of a size that makes them easily
collectible. Benthic macroinvertebrates show responses to a wide variety of potential pollutants, including
those with synergistic or antagonistic effects, as well to physical conditions, including quality and availability
of instream habitat. The City of Durham program is modeled after the DWQ benthic macroinvertebrate
program.
A majority of the benthic macroinvertebrate sites are co -located with ambient chemistry monitoring stations.
In general, Stormwater & GIS Services strives to include at least one benthic macroinvertebrate site in each
watershed monitored that year. Results are generally used to track changes over time, so sites generally
have a robust history of results. Samples are collected once during the year, as described in the City of
Durham's Standard Operating Procedures for Benthic Macroinvertebrates (Durham 2014b), with small
streams sampled in the spring (March - May) and larger streams and rivers sampled in summer (June -
September). Data collections are overseen by an experienced benthic biologist, who is also responsible for
sample identifications, data analysis, calculation of bioclassifications, and data interpretation. Field
parameters such as pH, specific conductance, turbidity, dissolved oxygen and temperature are collected
during each sampling event. A qualitative instream habitat assessment is also completed.
Hvdrologic Monitoring
The hydrology of City streams is critical to understanding the types of pollutants entering stream and their
impacts, though modifications to the hydrologic cycle can also directly impact stream morphology, sediment
transport, and the quality of instream habitat
Submitted 1111812020
Water enters streams through rainfall, runoff, groundwater discharge, and direct discharges. It is not
economically or technically feasible to monitor each of these routes of water entry for all City streams,
therefore hydrologic monitoring currently targets stream discharge and stage, and rainfall. Groundwater
wells are not currently installed or monitored by Stormwater & GIS Services. A brief description of each type
of monitoring is provided below:
Rainfall: At least hourly measurements of rainfall are needed to understand the short-term impacts of rainfall
on stormwater runoff and creek discharge. Stormwater & GIS Services obtains this type of information through
a variety of means, including partnerships with the NC Climate Center and the US Geological Survey.
Stream Discharge: All of the continuous discharge monitoring that occurs within the City of Durham is
accomplished in partnership with the US Geological Survey, which measures discharge every 15 minutes. The
USGS is the recognized national technical leader in stream discharge measurements. The stream discharge
measurements in the City of Durham are co -funded by Stormwater & GIS Services, the Army Corps of
Engineers, the Triangle Area Water Supply Monitoring Project, and the City of Raleigh.
Stream Stage. A reasonable surrogate to stream discharge, which is time consuming and expensive to
measure, is stream stage. Stream stage also provides a measure of peak flow and is useful in areas when
flooding is a concern. Stream stage measurements in the City of Durham are accomplished by Stormwater &
GIS Services and in partnership with the US Geological Survey.
7.9.3.2 In -Situ or Screening -Level Monitoring
This effort supports the following assessment goals:
• To identify illicit discharges to area streams
• To determine pollution removal credits
• To identify overall trends to water quality
• To evaluate the water quality impacts of urban stormwater on area streams
In -situ or field screening level monitoring programs include the illicit discharge detection program, the outfall
screening program, stream forensics studies, and response to sewer spills. Each of these programs requires
rapid analysis of surface water to determine if indicators of common types of illicit discharges are present
and to what extent. The methods used for monitoring are similar. Small samples of water are collected and
analyzed in the field to determine water quality conditions.
The Stormwater & GIS Services staff uses portable colorometric field chemistry kits to provide support for
real-time pollution tracking. The use of the field screening methods is described in the Stormwater & GIS
Services Investigations QAPP (Durham 2013?) and the Outfall Screening QAPP (Durham 2013?).
On a case -by -case basis, there may be a need for detailed or precise measurements such as those provided
by an analytical chemistry laboratory. When these cases arise, grab samples may be collected per the QAPP
and delivered to a state -certified analytical laboratory.
Field screening methods are performed on an as -needed basis and thus frequency and site location cannot
be specified in advance. Frequency may consist of before and after monitoring to characterize the problem
and resolution. More frequent analysis may be needed if an ongoing problem has been identified. Similarly,
monitoring locations may vary. Monitoring locations may include outfalls or other discharge pipes, ditches,
storm sewers and surface waters. In the case of outfall screening or illicit discharge detection,
documentation of frequency and locations will be provided in the Stormwater & GIS Services water quality
investigations database.
7.9.3.3 Stormwater Control Measures (SCM) Monitoring
Monitoring of SCMs supports the following assessment goals:
7-69
Submitted 1111812020
• To evaluate the performance of SCMs
• To determine pollution removal credits
• To evaluate the water quality impacts of urban stormwater on area streams
SCM monitoring may occur for a variety of reasons, on a variety of types of SCMs. SCM monitoring is typically
performed during storm events, since SCMs are designed to capture and treat stormwater runoff. Due to the
unpredictability of storm events, technicians will usually set up automated sampling equipment to begin
collecting samples in response to hydrologic changes during a storm event, such as a rise in stage. Wet
weather monitoring of SCMs is complicated and time-consuming. In many cases, Stormwater & GIS Services
will partner with local universities to accomplish wet weather monitoring on specific structural SCMs or SCM
enhancements.
The City of Durham has a wide variety of SCMs installed in the landscape, including dry ponds, extended dry
ponds, wet ponds, bioretention areas, and constructed wetlands. The City has also installed low impact
development retrofits, some of which are also monitored. Each of these SCMs functions in a different way
and may require different deployment for monitoring. Since SCM monitoring is typically performed as part of
a special study (Section 4.4), a site -specific monitoring plan is written prior to collecting samples. These site -
specific monitoring plans, usually in the form of a QAPP, describe the monitoring goals, locations, equipment
deployment, parameters, and quality assurance.
7.9.3.4 Special Studies
Special studies may be initiated to support any of the assessment and monitoring program goals. These
studies are typically short-term, occurring over 12 to 24 months. Special studies are may include water
chemistry, biological monitoring, hydrologic monitoring, or any other type of monitoring. In the past, these
studies have included activities such as habitat assessments, sediment quality monitoring, high flow
sampling, manual measurements of stream discharge, and surveys of aquatic weeds in addition to more
traditional water quality assessments.
Special studies may be generated from concerns or initiatives throughout Public Works. These studies are
vetted within the Water Quality Unit and if they are selected, a QAPP is written for the study, as required by
the Water Quality Unit's quality assurance program. QAPPs for special studies follow EPA guidance (EPA
1996.
Special studies may include contractors as well as technical staff from within Stormwater & GIS Services. In
many cases, contract laboratory support is used for these studies because of a varied parameter list or
alternate media (e.g., soil, algae). Special studies may also involve other agencies.
When data collection is not involved in a special study, a study plan will be developed instead of a QAPP. This
type of study is an alternate assessment of data already collected by the City of Durham and any partnering
agency. Both QAPPs and study plans are retained by the City of Durham electronically for an indefinite time
period, but no less than 10 years.
7-70
Submitted 1111812020
7.9.3.5 Reporting
Stormwater & GIS Services generates a large amount of
monitoring data within any 12-month period. Program
assessments are also performed on a regular basis and are
reported to the state permitting agency through annual reports,
the largest of which is the NPDES annual report. To
communicate with the residents of Durham, watershed
summaries are prepared annually and provided on the City's
website. These summaries describe results from the core
assessments in a less technical manner. One of the features of
this report is the Water Quality Index, an index developed for
Durham streams. This index has been adopted by City leaders
as a benchmark for the City Strategic Plan.
7-71
Durham Water Quality Index
Stormwater & GIS Services created a
water quality index (WQI) to relay surface
water chemistry information to the
citizens of Durham in an easily
understood format. The water quality
index is unique to Durham and accounts
for the following chemical and physical
parameters: dissolved oxygen, turbidity,
fecal coliform, total nitrogen, total
phosphorus, 5-day biochemical oxygen
demand, dissolved copper and dissolved
zinc. The annual average water quality
index is provided annually in online
summaries and in the City's
Sustainability and Strategic Plans.
Submitted 1111812020
7.10 Total Maximum Daily Loads (TMDLs)
This section of the permit is designed to ensure that MS4s address waste load allocations provided in EPA
approved TMDLs. The permit provides several objectives for the TMDL section, as follows:
• Determine whether the MS4 discharges to receiving waters within a TMDL watershed and identify the
pollutant(s) of concern (POC). For all TMDLs with a NPDES MS4 regulated stormwater waste load allocation
(WLA) assigned to the permittee, the permittee shall determine whether the POC have potential to occur in
MS4 stormwater discharges.
• Utilize BMPs within the six minimum measures and the permittee's TMDL Plan(s) to meet the permittee's
assigned NPDES MS4 regulated stormwater WLA identified in the approved TMDL to the maximum extent
practicable and to the extent allowable by law.
The permit considers the municipal MS4 to be in compliance with the TMDL if conditions of the permit are
met, including developing and implementing appropriate BMPs within the six minimum measures to address
the permittee's MS4 wasteload allocation. The permit recognizes that improved water quality is the
expected outcome.
Table 7-17: BMP Summary Table for EPA Approved TMDL Wasteload Allocations for the City of Durham
BMP
Measurable Goals
Frequency
Responsible
Position
(a) Identify.
Within 12 months of an EPA approved TMDL with
Within 12
Water Quality
Describe and
a permittee wasteload allocation the permittee
months of an
Analyst, Asst.
map watershed,
shall prepare a plan that:
EPA approved
Water Quality
outfalls, and
0 Identifies the watershed(s) subject to an
TMDL
Manager
streams
approved TMDL with an approved wasteload
allocation assigned to the permittee,
• Includes a description of the watershed(s)
and
• Includes a map of the watershed showing
streams and outfalls.
• Identifies the locations of currently known
major outfalls within its corporate limits with
the potential of contributing to the cause(s)
of the impairment to the impaired segments,
to their tributaries, and to segments and
tributaries within the watershed contributing
to the impaired segments; and
• Includes a schedule (not to exceed 6
months) to discover and locate other
unknown major outfalls within its corporate
limits that may be contributing to the cause
of the impairment to the impaired stream
segments, to their tributaries, and to
segments and tributaries within the
watershed contributing to the impaired
segments.
(b) Evaluate
Within 12 months of an EPA approved TMDL with
Within 12
Water Quality
existing
a permittee wasteload allocation the permittee's
months of an
Analyst, Asst
measures
plan shall:
EPA approved
Water Quality
TMDL, and
Manager
7-72
Submitted 11/18/2020
• Describe existing measures currently being
reviewed as
implemented by the permittee designed to
needed or
achieve the SM4's NPDES wasteload
with each
allocation and to reduce the TMDL pollutant
permit cycle
of concern to the maximum extent
practicable within the watershed to which the
TMDL applies
• Provide an explanation as to how those
measures are designed to reduce the TMDL
pollutant of concern
• Continue to implement the existing measures
until notified by the Division
(c) Assessment of
Within 24 months of an EPA approved TMDL with
Within 24
Water Quality
available
a permittee wasteload allocation the permittee's
months of an
Analyst
monitoring data
plan shall include an assessment of the available
EPA approved
monitoring data. Where long-term data is
TMDL, and
available, this assessment should include an
reviewed with
analysis of the data to show trends.
each permit
cycle
(d) Monitoring
Within 24 months of an EPA approved TMDL with
Within 24
Water Quality
Plan
a permittee wasteload allocation the permittee's
months of an
Analyst, Water
shall develop a monitoring plan for the
EPA approved
Quality
permittee's assigned NPDES regulated wasteload
TMDL, and
Specialists
allocation as specified in the TMDL. The
reviewed with
permittee shall maintain and implement the
each permit
monitoring plan as additional outfalls are
cycle
identified and as accumulated data may suggest.
Following any review and comment by the
Division the permittee shall incorporate any
necessary changes to the monitoring plan and
initiate the plan within 6 months. Modifications
to the monitoring plan shall be approved by the
Division.
(e) Additional
Within 24 months of an EPA approved TMDL with
Within 24
Water Quality
measures
a permittee wasteload allocation, the permittee
months of an
Analyst, Water
shall:
EPA approved
Quality Specialist
• Describe additional measures to be
TMDL, and
(Investigations
implemented by the permittee designed to
reviewed with
and Inspections)
achieve the MS4's NPDES wasteload
each permit
allocation and to reduce the TMDL pollutant
cycle
of concern to the maximum extent
practicable within the watershed to which the
TMDL applies; and
• Provide an explanation as to how those
measures are designed to achieve the MS$'s
NPDES regulated wasteload to the maximum
extent practicable within the watershed to
which the TMDL applies.
7-73
Submitted 1111812020
(f)
Within 48 months of an EPA approved TMDL with
Within 48
Water Quality
Implementation
a permittee wasteload allocation, the permittee
months of an
Analyst, Water
plan
shall:
EPA approved
Quality Specialist
• Describe the measures to be implemented
TMDL, and
(Investigations
within the remainder of the permit term
reviewed with
and Inspections)
designed to achieve the MS4's NPDES
each permit
wasteload allocation and to reduce the TMDL
cycle
pollutant of concern to the maximum extent
practicable;
• Identify a schedule, subject to Division
approval, for completing the activities
• Implement the permittee's TMDL plan
(g) Incremental
The permittee's plan must outline ways to track
Each permit
Water Quality
success
progress and report successes designed to
cycle
Analyst
achieve the MS4's NPDES regulated wasteload
allocation and to reduce the TMDL pollutant of
concern to the maximum extent practicable
within the watershed to which the TMDL applies
Reporting
The permittee shall conduct and submit to the
Annually
Water Quality
Division an annual assessment of the program
Analyst, Asst.
designed to achieve the MS4's NPDES wasteload
Water Quality
allocation and to reduce the TMDL pollutant of
Manager
concern to the maximum extent practicable
within the watershed to which the TMDL applies.
Any monitoring data and information generated
from the previous year are to be submitted with
each annual report.
The permit also states that existing TMDL or Water Quality Recovery plans that address the pollutant of
concern through the six minimum control measures satisfy the objectives of this section of the permit.
7.10.1 Existing Programs for Northeast and Third Fork Creeks
The 2007 NPDES Stormwater permit required the City of Durham to develop Water Quality Recovery
Programs (WQRPs) for waters with assigned MS4 wasteload allocations in approved TMDLs. These WQRPs
included requirements such as identifying locations of MS4 outfalls within the impaired watershed,
developing a monitoring plan for each pollutant of concern, a schedule for discovering and locating unknown
MS4 outfalls, a regular assessment of available data, and implementation of BMPs. The six minimum
measures were enhanced with a goal of reducing levels of pollutants of concern in MS4 discharges to
Northeast and Third Fork Creeks. The WQRP components were updated in each NPDES Annual Report.
Table 7-18. Water Quality Recovery Program Requirements (NCDENR 2007)
Required BMP
A
Within 24 months of the effective date of this permit or of becoming subject to an approved TMDL, the
permittee shall
establish a Water Quality Recovery Program,
identify the locations of currently known MS4 outfalls within its jurisdictional area with the potential of
discharging the pollutant(s) of concern: to the impaired segments, to their tributaries, and to segments
and tributaries within the watershed contributing to the impaired segments, and
7-74
Submitted 11/18/2020
develop a schedule to discover and locate other MS4 outfalls within its jurisdictional area that may be
discharging the pollutant(s) of concern: to the impaired stream segments, to their tributaries, and to
segments and tributaries within the watershed contributing to the impaired segments.
B
Within 36 months of the effective date of this permit or of becoming subject to an approved TMDL, the
permittee shall develop a monitoring plan for each pollutant of concern.
The monitoring plan shall include the sample location by verbal description and latitude and longitude
coordinates, sample type, frequency, any seasonal consideration, and a monitoring implementation
schedule for each pollutant of concern.
Where appropriate, the permittee may reduce the monitoring burden by proposing to monitor outfalls
that the Division would consider substantially similar to other outfalls.
The permittee may also propose in -stream monitoring where it would complement the overall monitoring
plan.
The monitoring plan shall be adjusted as additional outfalls are identified in accordance with the
schedule required in (a) above and as accumulating data may suggest.
C
The permittee shall include the location of currently known MS4 outfalls with the potential of discharging
the pollutant(s) of concern, the schedule for discovering and locating currently unknown MS4 outfalls with
the potential of discharging the pollutant(s) of concern, and the monitoring, in the first annual report due
no earlier than 12 months after the applicability of a TMDL.
D
The next and each subsequent annual report shall include an assessment of the available data for each
pollutant of concern, and an assessment of the effectiveness of the BMPs employed, to determine what, if
any, additional BMP measures may be necessary to address the MS4 NPDES regulated Waste Load
Allocation identified in the TMDL.
The permittee shall implement appropriate BMPs to control the MS4 NPDES Waste Load Allocation
portion of the pollutant load for the pollutant(s) of concern to the maximum extent practicable.
Implementation of the appropriate best management practices constitutes compliance with the standard
of reducing pollutants to the maximum extent practicable.
E
Following any review and comment by the Division on the TMDL Water Quality Recovery Program and
monitoring plan, the permittee shall incorporate any necessary changes into the program and/or
monitoring plan. The permittee shall incorporate the approved TMDL Water Quality Recovery Program into
the Stormwater Plan.
A 2017 review of monitoring data in Northeast Creek showed levels of fecal coliform bacteria increased
significantly at two different city monitoring locations. Although a standard update was provided in the 2017-
2018 annual report, an effort began in early 2018 to develop new pollution control plans for Northeast and
Third Fork Creeks to address the degrading water quality. The updated plans, referred to as TMDL Response
Plans, include additional enhancements to the six minimum control measures. The enhancements also
include measures to identify sources not previously discovered, plans for agencies that have complementary
authority for sources of pollution, and program modifications and additions to address other sources. TMDL
Response Plan development was expanded to include other city and county departments that have authority
to address the discharge of the pollutants of concern. After collectively identifying actions that could address
the pollutants of concern, these actions were ranked and order -of -magnitude cost estimates were
developed. The ranks were based on best professional judgement regarding the potential impact of the
action and whether the action would prevent a discharge to the aquatic environment. Additional actions
include modifications to the minimum control measures described in the NPDES permit, other structural
control measures that could be implemented by the stormwater program, and measures clearly outside of
the stormwater regulatory schema. Additional funding was not identified in the plans although several plan
actions will require funding in the future. TMDL Response Plans for Northeast and Third Fork Creeks are
provided in Appendix I.
7-75
Submitted 1111812020
Concurrent with the development of the TMDL Response Plans, the 2018 NPDES permit was issued. The
2018 permit includes many of the same elements as the WQRPs. Those items that were completed in the
WQRPs and continue to be required in the 2018 permit will continue to be reported or updated in the annual
reports.
Fundin
Funding for the TMDL Response Plans will include funds garnered from the stormwater operating budget as
well as capital improvement projects. The current plans do not include project budgets. Funding requests
less than $50,000 must be approved by the City Manager. Requests for greater than $50,000 must be
approved by the City Council. For projects to be undertaken by County agencies, requests for funding must
be approved by the County Commissioners. As implementation actions begin, cost estimates will be
prepared for each action that moves forward, including those that are completed using existing resources.
7.10.2 Future TMDL Response Plans
For EPA approved TMDLs after 2018, the City will complete all required BMPS in Table 7-17 on the time
schedule provided. As specified, planning -related BMPs occur during the first 24 months (two years),
including locating outfalls, evaluating existing measures, assessing monitoring data, developing a monitoring
plan, and describing additional measures to be implemented. Implementation is scheduled to begin within
48 months of EPA approval.
The planning aspects of TMDL Response Plans are less time consuming because most of the data already
exists, albeit in separate locations. Extensive GIS analysis has already identified outfalls throughout the City.
The current GIS layers include most of the stormwater and wastewater infrastructure in the City. This
includes major and minor outfalls, inlets, catch basins, etc. These GIS layers are used during dry weather
outfall screening. New, previously unknown, pipes identified while in the field are georeferenced and
brought to the attention of the GIS group for inclusion in the stormwater infrastructure inventory.
Stormwater staff conduct stream walks as part of watershed planning activities. Unmapped infrastructure is
noted during these stream walks. Watershed plans including stream walks have been conducted for the
Ellerbe, Third Fork, Northeast, Crooked (Southwest), and Little Lick Creeks, and the Eno River. The New Hope
Creek watershed planning activity, including stream walks, will begin in calendar year 2019. The remaining
watersheds are Lick and Stirrup Iron Creeks.
The City has an existing database of constructed SCMs, including those constructed with new development
and retrofit projects in the existing landscape. The City also has an ambient stream monitoring program that
includes water chemistry collection in most watersheds in the City. Ambient monitoring data is
supplemented with special studies as needed, and a special study may be needed to evaluate some aspect
of a TMDL. As mentioned in Section 7.9, special studies are planned at least triennially (every three years).
Identifying implementation measures, particularly within the minimum control measures, will depend on the
pollutant of concern and the knowledge of the drainage area. When the potential sources of the pollutant of
concern are apparent early in the planning process, the minimum control measures can be used to reach
residents and businesses in the target area. The IDDE and Inspections programs can be used to bring
discharges into compliance with the TMDL plan. When the potential sources are diffuse or difficult to
identify, a different approach will be needed. Additional measures may focus on identifying the sources and
pattern of discharge and the geographic location.
7-76
Submitted 1111812020
7.11 References
City of Durham (Durham). 2013a. Outfall Screening and Monitoring Standard Operating Procedures.
Stormwater & GIS Services, Water Quality Unit.
Ibid. 2013c. Illicit Discharge Detection and Elimination (IDDE) Investigations, Standard Operating
Procedures. DRAFT —In Revision. Stormwater & GIS Services, Water Quality Unit.
Ibid. 2013d. Industrial Stormwater Inspections Program Manual. DRAFT —In Revision. Stormwater & GIS
Services, Water Quality Unit.
Ibid. 2014a. Ambient Water Chemistry Monitoring Program Quality Assurance Project Plan. Stormwater &
GIS Services, Water Quality Unit. October
Ibid. 2014b. Standard Operating Procedures for Benthic Macroinvertebrate Community Monitoring for
Determination of Bioclassifications (DRAFT). Stormwater & GIS Services. Water Quality Unit.
Griffith, G.E., Omernik, J.M., et al. 2002, Ecoregions of North Carolina and South Carolina, (color poster with
map, descriptive text, summary tables, and photographs). Reston, Virginia, U.S. Geological Survey (map
scale 1:1,500,000).
NC Department of Environmental Quality (NC DEQ). 2018. Permit No. NCS000249 to Discharge Stormwater
Under the National Pollutant Discharge Elimination System. Division of Energy, Mineral, and Land Resources
US Environmental Protection Agency (EPA). 1992. NPDES Storm Water Sampling Guidance Document. EPA
833-B-92-001. Office of Water.
US Environmental Protection Agency (EPA). 1996. The Volunteer Monitor's Guide to Quality Assurance
Project Plans. EPA 841-B-96-003. Office of Wetlands, Oceans and Watersheds 4503F.
US Environmental Protection Agency (EPA). 2002. Guidance on Choosing a Sampling Design for
Environmental Data Collection. EPA QA/G-5S. Office of Environmental Information. Washington, DC
7-77