NCS000249_Revised SWMP_20231102

CITY O
DURHAM
City of Durham
Stormwater Management Plan
Permit Number NCS000249
Permit Issue Date: October 10, 2018
Submitted Date: November 1, 2023
Prepared by City of Durham, Public Works Department
Stormwater Division
Notice Under the Americans with Disabilities Act(ADAJ
A person with a disability may receive an auxiliary aid or service to effectively participate in City government activities by contacting the ADA
Coordinator at 919-560-4197 or ADA@DurhamNC.�ov as soon as possible.
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NCS000249 Stormwater Management Plan November 2023

Version History
Permit date Revision date Description of changes
October 10, 2018
April 6, 2023 Major reformat to be more similar to Phase II SMP guidance. Reduced
program requirements sections to remove information contained within
Standard Operating Procedures(SOPs)and provide more focus on
measurable results.
November 1, Post-Construction Site Runoff Controls sections(primarily Sections 7.2
2023 and 7.7) modified to provide updates to ordinance requirements and
address SL2023-108.
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NCS000249 Stormwater Management Plan November 2023

Contents
Introduction............................................................................................................................................................... 7
Certification............................................................................................................................................................... 8
1 MS4 Information ........................................................................................................................................... 9
1.1 Permitted MS4 Area .................................................................................................................................. 9
1.2 Existing MS4 Mapping............................................................................................................................... 9
1.3 Receiving Waters.....................................................................................................................................11
1.4 MS4 Interconnection...............................................................................................................................15
1.5 Total Maximum Daily Loads (TMDLs) .....................................................................................................15
1.6 Endangered and Threatened Species and Critical Habitat...................................................................16
1.7 Industrial Facility Discharges..................................................................................................................16
1.8 Non-Stormwater Discharges...................................................................................................................19
2 Stormwater Program Administration.......................................................................................................... 21
2.1 Departments and Positions Responsible for SMP Implementation .....................................................23
2.2 Funding.....................................................................................................................................................27
2.3 Shared Responsibility..............................................................................................................................29
2.4 Co-Permittees...........................................................................................................................................29
2.5 Tracking and Assessing the Permit Program .........................................................................................29
3 Public Education and Outreach on Stormwater Impacts............................................................................ 31
3.1Objectives for Public Involvement and Participation.............................................................................31
3.2 Target Pollutants, Audiences, and Behaviors ........................................................................................33
4 Public Involvement and Participation ......................................................................................................... 35
4.1Objectives for Public Involvement and Participation.............................................................................35
5 Illicit Discharge Detection and Elimination.................................................................................................. 37
5.1Objectives for Illicit Discharge Detection and Elimination ....................................................................37
5.2 Maintain Appropriate Legal Authorities..................................................................................................39
5.3 Maintain a Storm Sewer System Base Map of Major MS4 Outfalls.....................................................39
5.4 Inspection/Detection Program to Detect Dry Weather Flows at MS4 Outfalls....................................39
5.5 Employee Training ...................................................................................................................................39
5.6 Maintain Public Reporting Mechanisms.................................................................................................40
5.7 Documentation ........................................................................................................................................40
6 Construction Site Stormwater Runoff Control ............................................................................................ 41
6.1 Durham County Erosion Control Program ..............................................................................................42
6.2 North Carolina Department of Transportation.......................................................................................42
6.3 City Reliance-On and Coordination-With Authorized Programs.............................................................42
7 Post-Construction Site Runoff Controls....................................................................................................... 43
7.1 Post Construction Stormwater Management Program..........................................................................48
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NCS000249 Stormwater Management Plan November 2023

7.2 Ordinances...............................................................................................................................................48
7.3 SCM Design Standards............................................................................................................................51
7.4 Development Review Process.................................................................................................................51
7.5 As-Built Approval Process........................................................................................................................52
7.6 Nutrient Sensitive Waters (NSW) Protection Measures (for programs with development or
redevelopment draining to NSW waters)......................................................................................................54
7.7 Deed Restrictions and Protective Covenants.........................................................................................55
7.8 Operation and Maintenance ...................................................................................................................55
7.9 Setbacks for Built-upon Areas.................................................................................................................57
7.10 Educational Materials and Training for Developers............................................................................57
8 Pollution Prevention and Good Housekeeping for Municipal Operations.................................................. 58
8.1 Inventory of municipal facilities and operations....................................................................................61
8.2 Inspection and maintenance program for municipal facilities and operations...................................61
8.3 Site pollution prevention plans for municipal facilities.........................................................................61
8.4 Spill response procedures for municipal facilities and operations ......................................................62
8.5 Prevent or minimize contamination of stormwater runoff from all areas used for vehicle and
equipmentcleaning........................................................................................................................................62
8.6 Streets, roads, and public parking lots maintenance............................................................................62
8.7 Inspection and Maintenance (I&M)for municipally-owned or maintained stormwater control
measures and the storm sewer system........................................................................................................63
8.8 Staff Training............................................................................................................................................63
9 Program to Monitor and Evaluate Stormwater Discharges to Municipal Systems..................................... 64
9.1 Maintain an Inventory of Industrial Sites ...............................................................................................66
9.2 Inspection Program..................................................................................................................................67
10 Water Quality Assessment and Monitoring............................................................................................ 68
10.1 Assessment............................................................................................................................................68
10.2 Ambient Stream Monitoring..................................................................................................................71
10.2.1 Water Chemistry.................................................................................................................................72
10.2.2 Benthic Macroinvertebrate Community Assessments.....................................................................72
10.2.3 Hydrologic Monitoring........................................................................................................................72
10.3 Special Studies......................................................................................................................................73
11 Total Maximum Daily Loads (TMDLs)...................................................................................................... 74
11.1 Existing Programs for Northeast and Third Fork Creeks.....................................................................76
11.2 Future TMDL Response Plans ..............................................................................................................78
12 References............................................................................................................................................... 79
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NCS000249 Stormwater Management Plan November 2023

List of Figures
Figure 1. Public Works Department Organization (as of 10/29/2018) .............................................................24
Figure 2. City of Durham Post-Construction Stormwater Treatment...................................................................50
Figure 3. Example Venn Diagram Representation of Industrial Facility Inventory.............................................66
Figure4. Monitoring Cycle .....................................................................................................................................72
List of Tables
Table 1. Summary of Current MS4 Mapping.......................................................................................................... 9
Table 2. Summary of Linear Conveyance System Features.................................................................................. 9
Table 3. Summary of Point Conveyance System Features..................................................................................10
Table 4. Water Quality Classification of MS4 Receiving Waters for BIMS Indexed Streams. Neuse River Basin
.................................................................................................................................................................................11
Table 5. Water Quality Classification of MS4 Receiving Waters for BIMS Indexed Streams: Cape Fear River
Basin .......................................................................................................................................................................14
Table 6. Summary of Approved TMDLs.................................................................................................................15
Table 7. Potential Federally Listed Species/ Habitat Impacted by Surface Water Quality as of March 1, 2023
.................................................................................................................................................................................16
Table 8: List of Industrial Facilities with NPDES Permits.....................................................................................16
Table 9. Non-Stormwater Discharges ...................................................................................................................19
Table 10. Stormwater Division and other Public Works groups involved in Permit Activities...........................25
Table 11. City and County Staff Responsible for Program Area Measurable Results and Reporting...............26
Table 12. Stormwater Management Fund FY2022-23........................................................................................28
Table 13. Stormwater Capital Projects Funding FY2021-23...............................................................................29
Table 14. BMP Summary Table for Public Education and Outreach...................................................................31
Table 15. Target Audiences, Behaviors, and Pollutants......................................................................................34
Table 16. BMP Summary Table for the Public Involvement and Participation...................................................35
Table 17. BMP Summary Table for the IDDE Program.........................................................................................38
Table 18. BMP Summary Table for the Post-Construction Stormwater Management Program .......................44
Table 19. Thresholds for Application of Stormwater Pollutant Requirements...................................................49
Table 20. Nitrogen and Phosphorus Post-Development Loading Limits............................................................51
Table 21: BMP Summary Table for Pollution Prevention and Good Housekeeping for Municipal Operations.58
Table 22. BMP Summary Table for Monitoring and Control of Pollutants Entering the MS4............................65
Table 23. BMP Summary Table for Water Quality Assessment and Monitoring Program.................................68
Table 24. Assessment Program Core Goals.........................................................................................................69
Table 25. Assessment Program Supplemental Goals..........................................................................................70
Table 26. Rotating Monitoring Schedule for Water Chemistry Monitoring.........................................................71
Table 27. BMP Summary Table for EPA-approved TMDL Waste Load Allocations for the City of Durham.......74
Table 28. Water Quality Recovery Program Requirements (NCDENR 2007).....................................................77
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NCS000249 Stormwater Management Plan November 2023

Acronyms
BMP Best Management Practices
City City of Durham
CWEP Clean Water Education Partnership
DEMLR Division of Energy, Mineral,and Land Resources
DENR Department of Environment and Natural Resources
DO Dissolved Oxygen
DRB Development Review Board
EAB Environmental Affairs Board
EP&C Environmental Planning and Compliance
ESC Erosion and Sediment Control
FOG Fats,Oils,and Grease
GIS Geographic Information System
IDDE Illicit Discharge and Elimination
MS4 Municipal Separate Storm Sewer System
NCDEQ North Carolina Department of Environmental Quality
NCDOT North Carolina Department of Transportation
NIS Neighborhood Improvement Services
NOR Notice of Requirement
NPDES National Pollutant Discharge Elimination System
SCM Stormwater Control Measure
SMP Stormwater Management Plan
SOP Standard Operating Procedure
SPCA Sediment Pollution Control Act
SPPP Stormwater Pollution Prevention Plan
SSO Sanitary Sewer Overflow
TMDL Total Maximum Daily Load
TSS Total Suspended Solids
UDO Unified Development Ordinance
USGS United State Geological Survey
WLA Waste Load Allocation
WQ Water Quality
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NCS000249 Stormwater Management Plan November 2023

Introduction
The purpose of this Stormwater Management Plan (SMP) is to establish and define the means by which the
City of Durham will comply with its National Pollutant Discharge Elimination System (NPDES) Municipal
Separate Storm Sewer System (MS4) Permit and the applicable provisions of the Clean Water Act to meet
the federal standard of reducing pollutants in stormwater runoff to the maximum extent practicable.
This SMP identifies the specific elements and minimum measures that the City of Durham will develop,
implement, enforce, evaluate, and report to the North Carolina Department of Environmental Quality
(NCDEQ) Division of Energy, Minerals and Land Resources (DEMLR) in order to comply with the MS4 Permit
number NCS000249, as issued by NCDEQ. This permit covers activities associated with the discharge of
stormwater from the MS4 as owned and operated by the City of Durham and located within the corporate
limits of the City of Durham.
In preparing this SMP,the City of Durham has evaluated its MS4 and the permit requirements to develop a
comprehensive SMP that will meet the community's needs, address local water quality issues and provide
the minimum measures necessary to comply with the permit. The SMP will be evaluated and updated
annually to ensure that the elements and minimum measures it contains continue to adequately provide for
permit compliance and the community's needs.
Once the SMP is approved by NCDEQ, all provisions contained and referenced in this SMP, along with any
approved modifications of the SMP, are incorporated by reference into the permit and become enforceable
parts of the permit. Any major changes to the approved SMP will require resubmittal, review and approval by
NCDEQ, and may require a new public comment period depending on the nature of the changes.
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NCS000249 Stormwater Management Plan November 2023

Certification
By my signature below I hereby certify, under penalty of law, that this document and all attachments were
prepared under my direction or supervision in accordance with a system designed to assure that qualified
personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or
persons who manage the system, or those persons directly responsible for gathering the information, the
information submitted is,to the best of my knowledge and belief, true, accurate, and complete.
I am aware that there are significant penalties for submitting false information, including the possibility of
fines and imprisonment for knowing violations.
I am also aware that the contents of this document shall become an enforceable part of the NPDES MS4
Permit, and that both the Division and the Environmental Protection Agency have NPDES MS4 Permit
compliance and enforcement authority.
❑ I am a ranking elected official.
❑ lam a principal executive officer for the permitted MS4.
❑x I am a duly authorized representative for the permitted MS4 and have attached the authorization made in
writing by a principal executive officer or ranking elected official which specifies me as (check one):
❑ A specific individual having overall responsibility for stormwater matters.
❑X A specific position having overall responsibility for stormwater matters.
Signature: Z—Z�
.
Print Marvin G. Williams
Name:
Title: Director of Public Works
Signed this_1st day of November 20 23
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NCS000249 Stormwater Management Plan November 2023

1 MS4 Information
1.1 Permitted MS4 Area
This SMP applies throughout the corporate limits of the City of Durham, including all regulated activities
associated with the discharge of stormwater from the MS4.
1.2 Existing MS4 Mapping
The current MS4 mapping includes inlet structures (e.g., drop inlets, curb inlets, combo inlets, slab inlets,
and headwall inlets), connector structures (e.g.,junction boxes and manholes), outlet structures (e.g., end-
section outlets and headwall outlets), pipes, culverts, flow direction, open channels (e.g., ditch, stream, and
river), stormwater control measure facilities, watersheds, and stormwater regulatory basins. The current
linear and point conveyance system features are summarized in Table 2 and Table 3. The City has mapped
nearly the entire drainage system, including almost all public and private stormwater system structures 12
inches and larger. Much of the drainage in the City is on private property and is maintained by the property
owner; drainage easements on private property are platted as private easements. The stormwater
conveyance features can be viewed on the City's interactive map at https://maps.durhamnc.gov/P-omaps/.
The "Stormwater" map layer must be turned on to view the MS4 conveyance features.
Table 1.Summary of Current MS4 Mapping
Percent of MS4 Area Mapped 92.7 %
No. of Major Outfalls* Mapped 2,532 total
*An outfall is a point where the MS4 discharges from a pipe or other conveyance(e.g.a ditch)directly into surface waters. Major outfalls are
required to be mapped to meet permit requirements. A major outfall is a 36-inch diameter pipe or discharge from a drainage area>50-acres;and
for industrial zoned areas a 12-inch diameter pipe or a drainage area>2-acres.
Table 2.Summary of Linear Conveyance System Features
Linear conveyance features
Total, 2019 2023
Conveyance Feature City-wide
2013
Storm drain pipe miles 853 972 1,058
Total storm drain pipe miles 853 972 1058
Open Channel:
River miles 106 108 130
Stream miles 332 340 399
Ditch miles 178 179 182
Unknown miles 60 1* 0*
Total open channel miles 676 628 711
Number of pipe segments:
Storm drain pipe 52510 61469 68215
Culvert 1821 1816 1895
Driveway 1641 1813 1795
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NCS000249 Stormwater Management Plan November 2023

Minor' 363 502 527
Stub 1172 1121 1111+
Unknown 432 3+ 1+
Total#of pipe segments 57939 66847 73544
'Minor pipe segments are usually less than 12 inches in diameter.
*The number of"Unknown miles"has dropped because"flowlines"were excluded from the 2023 update.
"Flowlines"are used to represent sheetflow connectivity from the end of a storm drain system to a nearby
ditch,stream,or river. They do not represent actual linear conveyance.
'The number of"Unknown"and"Stub"type pipe segments has declined as City staff have continued to QC
the stormwater system and more accurately reflect what is in the ground.
Table 3.Summary of Point Conveyance System Features
Total, City- Durham
Conveyance Feature City- Private MS4 NCDOT Schools State
wide or County
Drop inlets 16,177 11,883 1695 1879 474 240
Curb inlets 11,939 3864 7523 392 144 16
Combo inlets 26,331 10,765 11,587 3676 211 90
Slab inlets 1032 755 128 108 28 12
End-section or 7249 3291 2424 1448 30 55
Headwall inlets
Inlet Subtotal 62,727 30,558 23,357 7503 887 413
Junction Boxes 1142 739 188 181 15 16
Manholes 4638 2895 1030 555 101 56
Connector Subtotal 5780 3634 1218 736 116 72
End-section or 11,956 7680 2535 1571 98 69
Headwall outlets
Outlet Subtotal 11,956 7680 2535 1571 98 69
Filterra 40 9 26 5
Manhole (BMP Access) 434 415 1 14 4
Riser Pipe 1149 1096 22 1 20 5
Weir 1285 1218 29 1 25 6
SCM-associated 2887 2738 78 2 39 19
Structures Subtotal
Other 1602 1496 54 1 39 6
Total, all nodes 84,952 46,106 27,242 9813 1179 579
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NCS000249 Stormwater Management Plan November 2023

1.3 Receiving Waters
The City of Durham MS4 is located within the Cape Fear and Neuse River Basins and discharges directly into
receiving waters as listed in Error! Reference source not found. and Table 5. Water Quality Classification of
MS4 Receiving Waters for BIMS Indexed Streams: Cape Fear River Basin below. Applicable water quality
standards listed below are compiled from the following NCDEQ sources: Waterbody Classification Map,
Impaired Waters and TMDL Map, and the most recent NCDEQ Final 303(d) List.
Table 4.Water Quality Classification of MS4 Receiving Waters for BIMS Indexed Streams. Neuse River Basin
Receiving Water Stream Index/ Water Quality Use
# Name AU Number Description Classification
(303d parameter&Year)
2 Eno River From Orange County SR 1561 to U.S. 27-2-(10) WS-IV; B; NSW
Highway 501
Sevenmile Creek 27-2-15 WS-IV; NSW
3 From source to Eno River
759-FO7
Jumping Run
(a.k.a.Warren
4 Creek) From source to Eno River 27-2-17 WS-IV; NSW
760-C10
Mill Creek(Crystal
5 Lake)873-A01 From source to Jumping Run 27-2-17-1 WS-IV; NSW
Crooked Creek
6 (a.k.a. Crooked From source to Eno River 27-2-18 WS-IV; NSW
Run Creek) 760-
D08
From U.S. Highway 501 to a point 0.5
7 Eno River mile upstream of City of Durham 27-2-(19) WS-IV; NSW
emergency pumping facility raw water
intake(Lat: 36 04'40 Long: 78 53 00)
From a point 0.5 mile upstream of
Eno River Durham emergency pumping facility raw 27-2-(19.3) WS-IV; NSW, CA
8 water intake to Durham emergency
pumping facility raw water intake
From City of Durham emergency pumping 27-2-(19.5) WS-IV; NSW
9 Eno River facility raw water intake to a point 0.5
mile upstream of Little River
10 Cub Creek From source to Eno River 27-2-20 WS-IV; NSW
11 Eno River
From a point 0.5 mile upstream of Little 27-2-(20.5) WS-IV; NSW, CA
River to Falls Lake, Neuse River
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NCS000249 Stormwater Management Plan November 2023

Table 4.Water Quality Classification of MS4 Receiving Waters for BIMS Indexed Streams. Neuse River Basin
Receiving Water Stream Index/ Water Quality Use
# Name AU Number Description Classification
(303d parameter&Year)
Little River(Little From a point 0.1 mile upstream of
12 River Reservoir) Durham Co SR 1461 to dam at Little 27-2-21-(3.5) WS-IV; NSW
River Reservoir
13 Little River From dam at Little R Reservoir to a point 27 2 21(6) WS-IV; NSW
0.9 miles from mouth
14 Cabin Branch From source to Little River 27-2-21-7 WS-IV; NSW
C; NSW
15 Ellerbe Creek From source to 1-85 bridge 27-5-(0.3)
(Fish Community 1998)
16 Ellerbe Creek
From 1-85 bridge to a point 2.2 miles 27-5-(0.7) WS-IV; NSW
upstream of Durham Co SR 1636
(Fish Community 1998)
From a point 0.2 miles upstream of WS-IV; NSW; CA
17 Ellerbe Creek Durham Co SR 1636 to Falls Lake, Neuse 27-5-(2)
River (Benthos 2008)
18 South Ellerbe From Source to Ellerbe Creek C; NSW
Creek
19 Goose Creek From source to Ellerbe Creek(note not all 27-5-1 WS-IV; NSW
of Goose Creek is WSWS)
20 Panther Creek From source to a point 1.1 mile 27-6-(1) WS-IV; NSW
downstream of Durham Cc SR 1818
21 Panther Creek From a point 1.1 mile downstream of 27-6-(2) WS-IV; NSW; CA
Durham Co SR 1818 to Falls Lake
Rocky Branch
22 From source to a point 0.5 mile upstream 27-7- 1 WS-IV; NSW
(Petty Lake,S of of Durham Co SR 1802 ( )
Redmill Rd)
From a point 0.5 mile upstream of
23 Rocky Branch Durham Co SR 1802 to Falls Lake 27-7-(2) WS IV; NSW; CA
Little Lick Creek From source to a point 0.4 mile upstream 27 9(0 WS-IV; NSW
24 (Patterson Rd) of Durham Co SR 1811 .5) (DO,turbidity 2008)
25 Chunky Pipe Creek From source to Little Lick Creek 27-9-(2)ut2 WS-IV; NSW(DO,
turbidity 2008)
Little Lick Creek
From a point 0.4 mile upstream of WS-IV; NSW; CA
26 (including portion Durham Cc SR 1811 to Falls Lake, Neuse 27-9-(2)
of Little Lick Creek (o0 2008)
arm of Falls Lake) River
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NCS000249 Stormwater Management Plan November 2023

Table 4.Water Quality Classification of MS4 Receiving Waters for BIMS Indexed Streams. Neuse River Basin
Receiving Water Stream Index/ Water Quality Use
# Name AU Number Description Classification
(303d parameter&Year)
27 Lick Creek
From source to Durham Co SR 1809 27-11-(0.5) WS-IV; NSW
(Southview Road) (Benthos 1998)
28 Stirrup Iron Creek From source to Brier Creek 27-33-4-2 C; NSW
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NCS000249 Stormwater Management Plan November 2023

Table 5.Water Quality Classification of MS4 Receiving Waters for BIMS Indexed Streams:Cape Fear River
Basin
Cape Fear River Basin
Receiving Stream Description Stream Index Water Quality Use
# Name Number Classification(303d
parameter&Year)
31
a New Hope Creek From source to a Sandy Creek 16-41-1-(0.5)a WS-V; NSW
31 From source to a point 0.3 mile upstream of
New Hope Creek 16-41-1-(0.5) WS-V; NSW
b Durham Co SR 2220
32 Mud Creek From source to New Hope Creek 16-41-1-10 WS-V; NSW
33 Sandy Creek From source to New Hope Creek 16-41-1-11 WS-V; NSW
34 From a point 0.3 mile upstream of Durham Co WS-IV; NSW
a SR 2220 to Durham Co SR 2220 16 41 1(11.5)a
(Benthos 2006)
34 New Hope Creek WS-IV; NSW(Benthos
b From Durham Co SR 2220 to I-40 16-41-1-(11.5)b 2000)
34 From I-40 to a point 0.8 mile downstream of
16 41 1(11.5)c WS IV; NSW
c Durham Co SR 1107
35
From source to a point 2.0 miles upstream of 16-41-1-12-(1) WS-V; NSW(Benthos
N.C. Hwy.54 2008,)
6
Third Fork Creek
16-41-1-12-(2)
From a point 2.0 miles upstream of N.C. Hwy. WS-IV; NSW(Benthos,
3
54 to New Hope Creek Copper 2008)
37 Gum Creek From source to New Hope Creek 16-41-1-13 WS-IV; NSW
38 Little Creek
From source to a point 0.7 mile downstream 16-41-1-15-(0.5) WS-IV; NSW
of Durham Co SR 1110 (benthos 2000)
Crooked Creek From source to a point 0.7 mile upstream of
39 16-41-1-16-(1) WS-IV; NSW
(Southwest Creek) mouth
40 From source to N.C. Hwy.55 16-41-1-17-(0.3) WS-V; NSW
Northeast Creek WS-IV; NSW
41 From N.C. Hwy.55 to Durham Triangle WWTP 16-41-1-17-(0.7)a (Copper 2008,
Turbidity 2018)
42 Buck Creek From source to Burdens Creek 16-41-1-17-1-1 WS-IV; NSW
From Durham County SR 2028 to Northeast
43 Burdens Creek 16-41-1-17-1-(0.7) WS-IV; NSW
Creek
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NCS000249 Stormwater Management Plan November 2023

1.4 MS4 Interconnection
The City of Durham may have interconnections with other regulated MS4s (e.g., Chapel Hill, Raleigh, and
Morrisville) at the boundary of the City of Durham limits; however, it is not possible to determine these
interconnections because the City does not have MS4 data from other municipalities to query this
information.
The City of Durham MS4 is interconnected with other non-municipal separate storm sewer systems such as
North Carolina Central University, Durham Technical Community College, Durham Public Schools, and
Durham County.
The MS4 does interconnect with the statewide NCDOT MS4 and includes:
• Interconnections receiving stormwater from the NCDOT MS4. The number of interconnections is estimated.
Quantity: 97
• Interconnections discharging stormwater into the NCDOT MS4. The number of interconnections is estimated.
Quantity: 220
• The City of Durham MS4 mapping does not identify interconnections with the NCDOT MS4; however,the
interconnections can be viewed by querying the City's stormwater drainage system data.
• The City of Durham MS4 mapping does include NCDOT MS4 outfalls.
1.5 Total Maximum Daily Loads (TMDLs)
The TMDL(s) listed in Table 6 below have been approved within the MS4 area, as determined by the map
and list provided on the NCDEO Modeling&Assessment Unit web page. The table also indicates whether
the approved TMDL has a specific stormwater Waste Load Allocation (WLA)for any watershed directly
receiving discharges from the permitted MS4, and whether a TMDL Response Plan has been implemented
to address the WLA.
Table 6.Summary of Approved TMDLs
Water Body Name TMDL Pollutant(s)of Concern Stormwater TMDL
Waste Load Response
Allocation Plan(Y/N)
(Y/N)
Third Fork Creek Turbidity Yes Yes
Northeast Creek Fecal coliform bacteria Yes Yes
B Everett Jordan Lake Chlorophyll a No Not
applicable
The chlorophyll-a TMDL for B. Everett Jordan Lake does not contain a municipal-specific waste load
allocation. However, state rules were adopted for nonpoint sources, including sources within the
municipality. State rules include requirements for new development and existing development. As of winter
2022-23, both sets of rules were in abeyance. Nutrient management continues to be a focus of the MS4
program, within the context of the six minimum measures.
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NCS000249 Stormwater Management Plan November 2023

1.6 Endangered and Threatened Species and Critical Habitat
The US Fish & Wildlife Service Environmental Conservation Online System and the NC Natural Heritage
Program website were consulted in March 2023 to determine federally threatened and endangered species
for Durham County. The overall list was reduced to aquatic species that may be impacted by stormwater.
The list of federal freshwater species that are threatened or endangered is provided in Table 7.
Table 7. Potential Federally Listed Species/ Habitat Impacted by Surface Water Quality as of March 1, 2023
Scientific Name Common name Species Group Federal Listing Status
Fusconaia masoni Atlantic Pigtoe Freshwater bivalve Threatened
Necturus lewisi Neuse River Waterdog Freshwater amphibian Threatened
Noturus furiosus Carolina Madtom Freshwater fish Endangered
The US Fish & Wildlife Service has published critical habitat areas within Durham County. These critical
habitat areas are described below for each species.
• Critical habitat areas for the Altantic Pigtoe (USFWS 2021b). Neuse River Basin, Eno River
Watershed. The designated critical habitat begins just below Eno Mountain Road in Orange County
and extends to NC Highway 15-501 in Durham County. From the county border between Durham and
Orange County to NC Highway 15-501, the critical habitat is primarily within the City of Durham.
• Critical habitat areas for the Neuse River Waterdog(USFWS 2021a). Neuse River Basin, Eno River
Watershed. The designated critical habitat begins at NC 86 in Orange County and extends
downstream to the inundated portion of Falls Lake in Durham County. From the county border
between Durham and Orange County, the critical habitat is largely within the City of Durham, with
some areas in Durham County.
• Critical habitat areas for the Carolina Madtom (USFWS 2021a). Neuse River Basin, Eno River
Watershed. The designated critical habitat begins at the Eno River State Park downstream of NC
Highway 70 in Orange County to the confluence with Cabin Creek near the Falls Lake impoundment
in Durham County. From the county border between Durham and Orange County, the critical habitat
is largely within the City of Durham, with some areas in Durham County.
1.7 Industrial Facility Discharges
The City of Durham MS4 jurisdictional area includes the following industrial facilities which hold NPDES
Industrial Stormwater Permits, as modified from the NCDEQ Maps & Permit Data web page. This online
NCDEQ database provided 113 facilities in the City of Durham. There were some discrepancies between the
NCDEQ table and the City of Durham list of industrial facilities, as follows:
• One facility, Harris Stratex, is not located in Durham County
• Nine facilities are no longer in business
• Two facilities are repeat entries
• Twenty-four facilities are located in the county
Table 8: List of Industrial Facilities with NPDES Permits
Permit Facility name Permit type
Number
NCGNE1081 ABF Freight System Inc- Stormwater Discharge, No Exposure Certificate
Durham
NCG080863 Academy Bus, LLC Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Water Separator Stormwater Discharge COC
NCG080441 Allied Waste Services Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Water Separator Stormwater Discharge COC
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NCS000249 Stormwater Management Plan November 2023

Permit Facility name Permit type
Number
NCGl00201 Always Buying Scrap, Inc. Used Motor Vehicle Parts Stormwater Discharge COC
NCG060397 Amazon.com Services Inc- Food/Tobacco/Soaps/Cosmetics/Public Warehousing
RDU5 Stormwater Discharge COC
NCG060411 Amazon.com Services LLC- Food/Tobacco/Soaps/Cosmetics/Public Warehousing
DRTB Stormwater Discharge COC
NCG060429 Amazon.com Services LLC- Food/Tobacco/Soaps/Cosmetics/Public Warehousing
HRD2 Stormwater Discharge COC
NCGNE1437 Amazon.com Services LLC- Stormwater Discharge, No Exposure Certificate
HRD2
NCGNE1400 Amazon.com Services LLC- Stormwater Discharge, No Exposure Certificate
RDUS_RST
NCG060430 Amazon.com Services LLC- Food/Tobacco/Soaps/Cosmetics/Public Warehousing
SNC3 Stormwater Discharge COC
NCGNE1299 Amazon.com.Services, LLC Stormwater Discharge, No Exposure Certificate
DRT1
NCGNE0886 American Greenz Stormwater Discharge, No Exposure Certificate
NCGNE0730 Andrews& Hamilton Company, Stormwater Discharge, No Exposure Certificate
Inc
NCGNE0750 Arrow-Intechra, LLC Stormwater Discharge, No Exposure Certificate
NCGNE1380 Bright View Technologies Stormwater Discharge, No Exposure Certificate
NCGNE1368 Cambrex Stormwater Discharge, No Exposure Certificate
NCGNE0932 Cardinal Health Stormwater Discharge, No Exposure Certificate
NCGNE1532 Cardinal Health at Home Stormwater Discharge, No Exposure Certificate
NCG080776 City of Durham Public Works Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Operation Center Water Separator Stormwater Discharge COC
NCG080773 City of Durham-Department of Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Solid Waste Mgmt Water Separator Stormwater Discharge COC
NCG080865 Couch Oil Company Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Water Separator Stormwater Discharge COC
NCGNE1241 Counter Culture Coffee Stormwater Discharge, No Exposure Certificate
NCG080984 Duke University Transportation Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Maintenance Garage Water Separator Stormwater Discharge COC
NCG080649 Durham City Transit Co. Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Water Separator Stormwater Discharge COC
NCS000249 Durham Ms4 Stormwater Discharge, Individual (MS4)
NCG140095 Durham Plt#603 Ready Mix Concrete Stormwater/Wastewater Discharge COC
NCGNE1183 Durty Bull Brewing Company Stormwater Discharge, No Exposure Certificate
NCGNE1152 Epiphany Craft Malt House Stormwater Discharge, No Exposure Certificate
NCG080807 Fedex Ground Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Water Separator Stormwater Discharge COC
NCGNE1175 FedEx Express RDU A Stormwater Discharge, No Exposure Certificate
NCG081018 FedEx Freight Inc.- RDU Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Water Separator Stormwater Discharge COC
NCGNE1256 FedEx Ground-Durham Stormwater Discharge, No Exposure Certificate
NCG080771 Fleet Maintenance Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Water Separator Stormwater Discharge COC
17
NCS000249 Stormwater Management Plan November 2023

Permit Facility name Permit type
Number
NCGl00024 Foss Auto Recycling, Inc. Used Motor Vehicle Parts Stormwater Discharge COC
NCGNE0068 GE Aircraft Engines Stormwater Discharge, No Exposure Certificate
NCG020088 Hanson Aggregates- Durham Mining Activities Stormwater Discharge COC
Quarry
NCGNE1262 Humacyte Stormwater Discharge, No Exposure Certificate
NCS000527 IPS Structural Adhesives Stormwater Discharge, Individual
NCG200478 J & D Recyclers Wholesale Trade of Metal Waste and Scrap Stormwater
Discharge COC
NCGNE1505 KBI Biopharma Inc.- Emperor Stormwater Discharge, No Exposure Certificate
Rd
NCGNE1506 KBI Biopharma Inc.- National Stormwater Discharge, No Exposure Certificate
Way
NCGlOO151 Lifetime Audi Parts Used Motor Vehicle Parts Stormwater Discharge COC
NCGNE0090 Logic Marine Stormwater Discharge, No Exposure Certificate
NCG140445 Muirhead Distribution Center Ready Mix Concrete Stormwater/Wastewater Discharge COC
(MDC)
NCG081002 National Express Transit- Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Durham Water Separator Stormwater Discharge COC
NCGNE0382 NC Nat Gd-Durham Stormwater Discharge, No Exposure Certificate
NCG080881 NCCU Physical Plant Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Water Separator Stormwater Discharge COC
NCG110092 North Durham WRF Municipal WWTP > 1MGD,Stormwater Discharge, COC
NCGNE1436 Novartis Gene Therapies Stormwater Discharge, No Exposure Certificate
NCGNE0437 Nuvotronics LLC Stormwater Discharge, No Exposure Certificate
NCGNE0436 PBM Graphics -SW Stormwater Discharge, No Exposure Certificate
NCGNE1306 Phononic Inc Stormwater Discharge, No Exposure Certificate
NCG050441 Ply Gem Foundation Labs Apparel/Printing/Paper/Leather/Rubber Stormwater Discharge
COC
NCGNE1186 Ponysaurus Brewing Company Stormwater Discharge, No Exposure Certificate
NCGNE1563 PowerSecure Distributed Stormwater Discharge, No Exposure Certificate
Infrastructure
NCG140127 Ready Mix Concrete- Durham Ready Mix Concrete Stormwater/Wastewater Discharge COC
Plant
NCG140129 Ready Mix Concrete-Durham Ready Mix Concrete Stormwater/Wastewater Discharge COC
Hwy 55 Plant
NCGNE1367 Resilience Durham Stormwater Discharge, No Exposure Certificate
NCGNE0096 RR Donnelley/Litho Plant Stormwater Discharge, No Exposure Certificate
NCG130100 S Hoover Road Recycling& Wholesale Trade of Non-metal Waste and Scrap Stormwater
Transfer Station Discharge COC
NCG080987 Salem Leasing Corp.- Durham Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Water Separator Stormwater Discharge COC
NCG130061 Shimar Recycling Wholesale Trade of Non-metal Waste and Scrap Stormwater
Discharge COC
NCG130010 Sonoco Products Co-Durham Wholesale Trade of Non-metal Waste and Scrap Stormwater
Discharge COC
18
NCS000249 Stormwater Management Plan November 2023

Permit Facility name Permit type
Number
NCG080930 Southeastern Freight Lines, Inc. Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Water Separator Stormwater Discharge COC
NCGNE0717 Southern Express Inc. Stormwater Discharge, No Exposure Certificate
NCG130019 Strategic Materials(Durham) Wholesale Trade of Non-metal Waste and Scrap Stormwater
Discharge COC
NCG140218 Thomas Concrete of Carolina Ready Mix Concrete Stormwater/Wastewater Discharge COC
Inc- Durham
NCGl00232 Triangle Auto Recyclers LLC Used Motor Vehicle Parts Stormwater Discharge COC
NCGNE0876 Triangle Brewing Co Stormwater Discharge, No Exposure Certificate
NCG080382 United Parcel Service-Durham Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Water Separator Stormwater Discharge COC
NCGNE0960 UPS Supply Chain Solutions Stormwater Discharge, No Exposure Certificate
NCG080809 UPS-Morrisville Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Water Separator Stormwater Discharge COC
NCGNE0519 Valassis Communications Stormwater Discharge, No Exposure Certificate
Incorporated
NCG100026 Wagner Auto Salvage Used Motor Vehicle Parts Stormwater Discharge COC
Incorporated
NCG200467 Wall Recyling LLC- Durham Wholesale Trade of Metal Waste and Scrap Stormwater
Discharge COC
NCG080845 Waste Industries, LLC-Durham Transportation w/Vehicle Maintenance/Petroleum Bulk/Oil
Water Separator Stormwater Discharge COC
NCG030433 Wolfspeed Incorporated- Metal Fabrication Stormwater Discharge COC
Durham
1.8 Non-Stormwater Discharges
The water quality impacts of non-stormwater discharges have been evaluated by the City of Durham as
summarized in Table 9 below. The unpermitted non-stormwater flows listed as incidental do not significantly
impact water quality. The City of Durham has evaluated residential and charity car washing and mobile car
washing for possible significant water quality impacts. While residential and charity car washing were
evaluated qualitatively, mobile car washing was evaluated quantitatively(City of Durham 2012). The Division
requires collection and proper disposal of mobile car washing wash water. Mobile car washing is addressed
through the six minimum measures, primarily through public education and illicit discharge detection. Wash
water associated with car washing that does not contain detergents or does not discharge directly into the
MS4 is considered incidental.
The impact of cleaning air conditioner coils may also cause water quality impacts. The City of Durham
evaluated the water quality associated with air conditional coil cleaning quantitatively (City of Durham
2016). Collection and proper disposal of air conditioning coil cleaning wash water is also required. Air
conditional coil cleaning wash water is addressed through the six minimum measures, primarily through
public education and illicit discharge detection.
Table 9. Non-Stormwater Discharges
Non-Stormwater Discharge Water Quality Impacts
Water line and fire hydrant flushing Incidental
Landscape irrigation Incidental
Diverted stream flows Incidental
Rising groundwater Incidental
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NCS000249 Stormwater Management Plan November 2023

Uncontaminated groundwater infiltration Incidental
Uncontaminated pumped groundwater Incidental
Uncontaminated potable water sources Incidental
Foundation drains Incidental
Air conditioning condensate Incidental
Irrigation waters Incidental
Springs Incidental
Water from crawl space pumps Incidental
Footing drains Incidental
Lawn watering Incidental
Residential and charity car washing Possible
Mobile car washing Possible
Flows from riparian habitats and wetlands Incidental
Dechlorinated swimming pool discharges Incidental
Street wash water Possible
Flows from firefighting activities Incidental
Air conditioning unit coil cleaning Possible
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NCS000249 Stormwater Management Plan November 2023

2 Stormwater Program Administration
This section introduces the general organizational structure of the City and discusses the city and county
departments that play significant roles in carrying out this SMP. Also summarized are general departmental
responsibilities, funding, and tracking of Stormwater Management Plan Goals and practices that will be
further discussed in subsequent sections.
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 2,774 full-time employee positions
authorized in the FY23 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 1 showing the departments and reporting paths
within the City. Annual reports and future SMPs will provide updates on the City's organizational structure.
21
NCS000249 Stormwater Management Plan November 2023

Elaine Monique Jillian DeDreana Mark-Anthony Leonardo
CITY OF O'Neal Caballero Holsey-Hyman Johnson Freeman Middleton Williams
DURHAM wards ward2, Ward
Mayor Pro Tem pore
r-------------- Mayor and City Council --------------�
i I i
i
i
i
Wanda S-Pag Diana Schreiber
City Manager City Clerk
Budget&Management Services Audit Services
Communications Human Resources
Public Safety Operations Community Building
- W-l3owman Ferguson Bertha I Johnson Keith Chadwell
ieputy C-dy Man-jer Deputy City Manager Deputy
Finance
Emergency Communications
Fleet Management . Neighborhood Improvement
City/County Services
Emergency Management General Services — Community Development —
Public WorksWorkforce
Solid Waste Management — Development
•. Technology Solutions
Water Management
City/County Department
Figure 1.City of Durham Organizational Structure(as of 02/2023)
22
NCS000249 Stormwater Management Plan November 2023

2.1 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
maintaining the municipal stormwater system. The Public Works Department is organized under three
Assistant Directors, as shown in Figure 2. City of Durham Public Works Department (228 FTEs) (Stormwater
Functions Shaded) Annual reports will provide updates regarding the 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 listed below.
23
NCS000249 Stormwater Management Plan November 2023

Director of Public Works
(Office of the Director)
Executive Business
Assistant Services
Manager
Operations&
Safety
Asst. Director Asst. Director
IS/Stormwate Asst. Director
Billing Engineering Services Stormwater
Maintenance Operations
Engineering Street&
Design,Survey Water Quality Inventory Maintenance Stormwater
&Utility Locate Control Administration
Maintenance
Contract Stormwater
Management Development Street
Review Maintenance
Development Stormwater
Review& Infrastructure Street Cleaning
Engineering
Services
Watershed
Planning& Stormwater
Inspections Implementation Maintenance
Concrete
Maintenance
Special Projects
Figure 2. City of Durham Public Works Department(228 FTEs)(Stormwater Functions Shaded)
Stormwater 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
four work groups within the Stormwater and GIS Services Division:
• Stormwater Infrastructure
• Stormwater Development Review
• Stormwater Quality
• Watershed Planning and Implementation
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NCS000249 Stormwater Management Plan November 2023

Table 10.Stormwater Division and other Public Works groups involved in Permit Activities
Stormwater Infrastructure Stormwater Development Review
Responsible for: Drainage projects, Drainage Responsible for: Engineering and developer
response, Floodplain response(including National seminars,As-built certification process for
Flood Insurance Program), Drainage inspections completed stormwater BMPs,Annual stormwater
BMP inspection process, Certification programs for
as-built certification and for annual inspection,
Maintenance of the SCM Tool database of BMPs.
Stormwater Quality Watershed Planning and Implementation
Responsible for Illicit discharge programs, Responsible for Watershed planning, Resident and
Inspection of industrial and light industrial facilities, local school outreach, Green infrastructure, Existing
Inspection of city facilities and technical support, development retrofits
Water quality monitoring programs,TMDL
Response Plans, Municipal training, Business
outreach
Other Public Works Groups
GIS&Stormwater Billing Street Maintenance.
Responsible for:Stormwater utility billing and Responsible for Operation of a fleet of street
customer service, Mapping parcel based sweepers that clean city streets, gutters and inlet
impervious surfaces to support billing,Technical grates, Pick up trash along the right of way,
support for the SCM and investigations databases, Manually cleaning bus stops, Performing dead
Maintaining GIS inventories of the stormwater, animal pickup.
water system,sewer systems,street centerlines
Stormwater Maintenance
Responsible for: Maintaining roadside ditches,
Repairing catch basins, Inspecting buried pipes and
other stormwater features.Vactor trucks are used
to clean inlets and associated piping.
Other City and County departments assist with implementing small portions of permit required programs.
Some of these departments receive regular training(See Section 8 Pollution Prevention and Good
Housekeeping for Municipal Operations)to ensure they are up to date on reporting requirements.
Other City/County departments assisting with Public Education and Outreach, or Public Involvement:
• The Solid Waste 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.
Other City/County departments assisting with Illicit Discharge Detection and Elimination:
• 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 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. Water Management also reports releases of sanitary
sewage from private sources as illicit discharges.
• The City Attorney's Office handles stormwater- related legal matters, including assistance with
ordinance development, support of enforcement efforts, and review of contracts and agreements.
• Fire Department(Spill 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.
25
NCS000249 Stormwater Management Plan November 2023

• Solid Waste Department. 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.
• The City/County Emergency Management 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.
County departments responsible for Construction Runoff associated with new development:
• 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.
Within multiple City and County departments are the key persons responsible for measurable results and
reporting. Those positions and people that are responsible for reporting measurable results are provided
below in Table 11.
Table 11.City and County Staff Responsible for Program Area Measurable Results and Reporting
Position I Person Program Area
Public Works Department
Director Marvin Williams Signature Authority
Assistant Director, Stormwater Division Paul Wiebke Program Budget
Public Hearings
Stormwater Development Review Manager Vacant Post-Construction Runoff
SCM Maintenance Program Coordinator Bill Hailey Post Construction Runoff
PPG H
Stormwater Infrastructure Manager Donald Perry Program Budget-CIP
PPG H
Water Quality Manager Michelle Woolfolk Reporting
Public Education &Outreach
Public Involvement
IDDE
PPGH
Industrial Inspections
Assessment& Monitoring
Total Maximum Daily Loads
Assistant Water Quality Manager J.V. Loperfido Assessment& Monitoring
Total Maximum Daily Loads
Assessment and Monitoring Joseph Smith Assessment& Monitoring
Total Maximum Daily Loads
This is discussed at length in Section 3.1.3.
26
NCS000249 Stormwater Management Plan November 2023

Position Person Program Area
Pollution Prevention Coordinator Anna Smith Public Education &Outreach
Public Involvement
PPGH
Total Maximum Daily Loads
Total Maximum Daily Load Coordinator Jonathan Baker Total Maximum Daily Loads
Investigations and Inspections James Azarelo IDDE
PPGH
Industrial Inspections
Total Maximum Daily Loads
Watershed Planning& Implementation Manager Sandra Wilbur Program Budget-CIP
Public Education &Outreach
Public Involvement
Total Maximum Daily Loads
Stormwater Public Education Coordinator Laura Smith Public Education &Outreach
Public Involvement
Total Maximum Daily Loads
Assistant Director, Street Maintenance Phillip Powell PPGH
Total Maximum Daily Loads
Operations Center Maintenance
Spill Response Program
Street Maintenance
Street Maintenance Business Systems Trudy Boehm PPGH
Coordinator
Street Cleaning Supervisor Benita Quick PPGH
General Services Department
Director Jina Propst
Keep Durham Beautiful, Inc. Exec. Director Tania Dautlick Public Education &Outreach
Public Involvement
Durham County
Engineering Department
Engineering Manager Jay Gibson
Stormwater& Erosion Control Division Manager Ryan Eaves Construction Runoff
Total Maximum Daily Loads
Erosion Control Supervisor Jonathan McNeill Construction Runoff
Total maximum Daily Loads
2.2 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 residential,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. For FY2023, City
Council approved a total City budget of$570.4 million, including$28.9 million for stormwater management.
Information from the FY2022 Annual Report is provided below:
,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.
27
NCS000249 Stormwater Management Plan November 2023

Table 12.Stormwater Management Fund FY2022-23
Actual Adopted Estimated Adopted Change
FY2020-21 FY2021-22 FY2021-22 FY2022-23
Authorized
Positions
Public Works,full 95.5 96.5 96.5 96.5 0%
time
Revenues
Operating $18,628,850 $18,226,156 $18,314,110 $19,768,691 8.5%
Revenues
(Stormwater
utility)
Interest& Rental $ 65,352 $44,000 $ 65„352 $65,352 48.5%
Income
Transfers from $109,047 $109,047 $109,047 $109,047 0.0%
Other Funds
Appropriations - $-5,551,725 -$ 5,256,723 $ 8,924,577 60.8%
from Fund
Balance
Total Revenues $18,803,249 $ 23,930,928 $23,745,232 $28,867,667 20.6%
Appropriations
Personal $ 8,607,895 $ 9,976,374 $10,009,624 $9,956,969 -0.2%
Services
Operating $ 3,232,814 $4,118,666 $ 3,880,720 $4,725,198 14.7%
Capital and Other $502,658 $ 5,000 $ 24,000 $56,000 1020.0%
Transfers to $ 2,734,000 $ 8,524,500 $ 8,524,500 $14,129,500 65.8%
other Funds*
Transfers to Fund $ 3,725,882 $ 1,306,388 $ 1,306,388 - -100.0%
Balance
Total $18,803,249 $23,930,928 $23,745,232 28,867,667 20.6%#
Appropriations
Departmental
Appropriations
Public Works $ 10,589,381 $ 11,574,196 $ 11,394,579 $ 11,706,171 1.1%
Nondepartmental 8,213,869 12,356,732 $ 12,350,653 $17,161,496 38.9%
Appropriations
Total $ 18,803,249 $ 23,930,928 $ 23,745,232 $ 28,867,667 20.6%
Appropriations
Source: FY2022-2023 City Budget,pages 80 and 102.
*Includes transfers to Capital Improvement Program(CIP)
Non-departmental charges include a payment to the General Fund for indirect costs and payment to the Risk
Fund for insurance.
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NCS000249 Stormwater Management Plan November 2023

Table 13.Stormwater Capital Projects Funding FY2021-23
Category Appropriation
FY2021 FY2022 FY2023
Algae Turf Scrubber/Algal Floway $0 $1,225,000 $ 750,000
Drainage Repair of City Owned Properties ($600,000) $0 $100,000
Floodplain Mitigation $0 -$0 $0
Major Stormwater Infrastructure&* BMP $2,740,000 $3,436,941 $2,200,000
Improvements
South Ellerbe Stormwater Restoration $0 $3,400,000 $7,400,000
Private Property Drainage Projects ($400,000) $0 $500,000
Stormwater Fleet Vehicles $ 534,000 $499,500 $499,500
Stormwater Retrofitting ($300,000) $500,000 $800,000
Watershed Planning& Design ($300,000) $100,000 $980,000
Emergency Watershed Protection $1,074,177 $0 $202,848
Within the Stormwater Division, budget needs are managed and coordinated by the Assistant Public Works
Director of Stormwater based on input from the work groups within the division. The Assistant Public Works
Director of Stormwater 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 is then sent to the City Manager's Office and the City Council for further approvals.
2.3 Shared Responsibility
As indicated in NCS000249, and explicitly acknowledged in the permit and this SMP Plan, construction site
runoff within the City of Durham is regulated by three other entities: Durham County Stormwater and Erosion
Control Program (which handles construction projects by entities that do not have the power of eminent
domain such as private projects); North Carolina Department of Transportation (which handles state road
projects); and the North Carolina Division of Energy, Mineral, and Land Resources, Land Quality(which
handles projects by entities with eminent domain authority or that are publicly funded).
The City of Durham operates its own Public Education and Outreach Program. The City is also a founding
member of the Clean Water Education Partnership, for which it is the second largest source of funding, and
City stormwater staff members actively participate in selection of themes, messages, and target markets for
mass media education.
2.4 Co-Permittees
There are no co-permittees involved in this SMP.
2.5 Tracking and Assessing the Permit Program
The Public Works Department's Stormwater Division tracks a wide range of metrics to assess workload,
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 units
to assess inefficiencies, inform training needs, enhance accountability, and maintain performance. Many
indicators are also used to track progress toward meeting the goals of this Stormwater Management Plan.
These appear in the tables for each program area. Annual assessments of each program are reported within
the Annual Report.
The City plans to conduct a third-party audit of the program approximately 12 to 18 months prior to a
scheduled state audit. NCDEMLR has indicated they plan to audit municipalities in the fourth year of the
permit cycle. The third-party audit covers all programs in the permit, the SMP and the Annual Reports. This
third-party audit, also called the self-audit, is available to DEMLR upon written request.
29
NCS000249 Stormwater Management Plan November 2023

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NCS000249 Stormwater Management Plan November 2023

3 Public Education and Outreach on Stormwater Impacts
3.1 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 14 contains a summary of the BMPs used to educate the public and perform outreach concerning the
activities of this program.
Table 14. BMP Summary Table for Public Education and Outreach
Schedule for Annual
BMP Description Measurable Goals Implementation Reporting
Metric
(a) Describe target Target pollutants,sources and Year 1 of permit Target pollutants
pollutants and target audiences are summarized below. cycle included in SMP
pollutant sources
(b) Describe target Year 1 of permit Target audiences
audiences cycle included in SMP
(c) Informational The City promotes and maintains Continuous Page views for
Website the Stormwater Division Website: web pages 692
www.durhamnc.gov/692. (Division), 3218
(Preventing
Pollution), &
4648(State of
Our Streams)
Clean Water Education Partnership Continuous Click-through
website www.NC-cleanwater.com is rates from ad
updated at least once per year and campaigns in
is featured in ad campaigns CWEP annual
report;Annual
web page
updates
(d) Distribute Public Waterways newsletter to target Semiannually Date(s)
Education Materials to homeowners and residents is Waterways
identified user groups distributed as water bill insert and newsletter
published to web page distributed., List
of topics covered
Develop and distribute information Annually Target audience
to target business sectors via and number of
targeted mailing(one sector per
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NCS000249 Stormwater Management Plan November 2023

year)and industry-specific guidance materials
documents. distributed
Educate residents about target Periodically at Dates of
pollutants and stormwater issues events distribution,
through topic-specific handouts description of
materials, list of
target pollutants
(e) Promote and Distribute customized giveaways to Periodically List of
Maintain Hotline/Help promote the hotline. Promote promotions/givea
line hotline through social media and ways
written handouts.
Maintain a stormwater pollution Continuous Number of days
reporting hotline. hotline was
operational
(f) Implement a Public Media Campaign: Document Annually Number of
Education and Outreach campaign impressions for each impressions
Program type of media (including those
elements implemented locally or
through a cooperative agreement).
Participate in community events Periodically Number of
and festivals through tabling. events per year,
number of people
reached
Maintain a speaker's bureau that Annually Number of
gives presentations to civic presentations per
organizations, business and year, number of
neighborhood groups. people reached
Organize Creek Week educational Annually Number of
events events, number
of participants
Outreach to classrooms,school Periodically Number of
groups, and educators. presentations,
number of people
reached
Develop and/or promote videos to Continuous Number of new
educate the public on pollution videos produced,
sources and the city's effort to number of video
reduce stormwater impacts views
State of Our Streams report on Annually State of our
water quality conditions and results Streams update
from illicit discharge investigations on City web site
Provide outreach through social Continuous Number of posts,
media. post reach or
impressions
Written Standard Operation Biennially(i.e., Review memo
Procedures in place and reviewed every two years) complete?
annually
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NCS000249 Stormwater Management Plan November 2023

3.2 Target Pollutants, Audiences, and Behaviors
Target pollutants for stormwater education include fecal coliform bacteria, nitrogen, phosphorus, low DO,
turbidity, and copper.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. Copper seems to be
associated with the following sources: a limited number of industrial sites, air conditioning coil cleaning, air
conditioner blow-down, discharges from fountains, discharges from underground electrical vaults, and
vehicles. Most 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.
Pollutant Sources:
• Illicit Dischar es - 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.
• Atmospheric Deposition - Broad efforts to improve air quality, reduce emissions of greenhouse gasses, and reduce
dependence on petroleum will have water quality benefits.
Table 15 identifies target audiences, key behavior changes, and the corresponding target pollutants. Not all
of the audiences identified below will be addressed each year. However, each audience will be addressed at
least once during the permit period. Furthermore, Stormwater 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.
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NCS000249 Stormwater Management Plan November 2023

Table 15.Target Audiences, Behaviors, and Pollutants
Target Audiences Behaviors and Activities Potential Target Pollutants
General public Identify and report any illicit discharges to the MS4 All
Homeowners, rental Disconnect rooftop drains from the MS4, installing rain gardens, Fecal coliform bacteria
property using rain barrels or cisterns, regularly clean organic debris from
owners/managers gutters, plant trees that will shade driveways and other paved Nitrogen
surfaces, dispose of FOG properly, maintain septic system (if
Phosphorus
applicable), repair and maintain sewer service lines, proper disposal
of household hazardous waste, garbage can/dumpster maintenance Low DO
Turbidity
Copper
Lawn care, landscaping Testing soil before applying fertilizers, reading instructions on Nitrogen
professionals fertilizers, pesticides, and herbicides before applying them to a lawn
or garden, not applying lawn chemicals before it rains, minimizing Phosphorus
fertilizer usage, using slow-release organic forms of nitrogen fertilizer,
using integrated pest management rather than broad spectrum Low DO
pesticides on a regular basis, and keeping leaves and grass clippings
out of the street gutter by properly disposing of or composting them, Turbidity
maintaining stream buffers
Vehicle owners, Proper disposal of any wastes from home maintenance; regularly Copper
automotive maintain vehicles so that they don't leak fluids;wash vehicles in such
maintenance facilities a manner that the run-off doesn't enter storm drains; properly use,
store, and dispose of automotive fluids and other wastes such as
tires;spill cleanup best practices and notification protocol
Restaurants Proper disposal of FOG, best practices for cleaning equipment, Fecal coliform bacteria
dumpster maintenance
Low DO
HVAC Contractors Proper disposal of wastewater from washing coils,vent cleaning, Copper, oxygen consuming
maintenance of filter units,and pressure washing. waste
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NCS000249 Stormwater Management Plan November 2023

4 Public Involvement and Participation
4.1 Objectives for Public Involvement and Participation
Provide opportunities for the community, including major socioeconomic and ethnic groups,to participate in
program development and implementation.
Table 16 contains a summary of the BMPs used to involve residents in the stormwater management process
and involve them in protecting our local water quality. Details on each approach are found in standard
operating procedures and are available upon request.
Table 16. BMP Summary Table for the Public Involvement and Participation
BMP Measurable Goals Schedule for Annual Reporting
Implementation Metric
a)Volunteer Organize/sponsor volunteer stream Semiannually Number of
Community cleanup campaigns that promote participants
Involvement resident participation such as Creek
Program Week cleanups and Big Sweep
cleanups
Work with residents to label storm Periodically Number of labels
drains applied, number of
volunteers
Sponsor an adopt-a-drain program Continuous Number of drains
adopted
Litter prevention programs through Continuous Pounds of litter
Keep Durham Beautiful (KDB) removed as reported
in KDB annual report
(b) Establish a Presentations to the Environmental Periodically List of presentation(s)
Mechanism for Affairs Board,typically including
Public annual Water Quality Monitoring Plan,
Involvement TMDL Response Plans, and other
topics of interest
Public information sessions are held to Periodically Number of sessions,
solicit public input on watershed plans, number of participants
major construction projects, retrofit
plans, ordinance revisions
© Maintain a The City will continue to maintain and Continuous Hotline operational?
Hotline promote a stormwater pollution
reporting hotline
(d) Public Review Stormwater Management Plan has Permit cycle SMP posted online
and Comment been posted to web site 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 Continuous Number of public
notice requirements for rate changes; notices issued
watershed planning; proposed projects complaint with state
that impact public use, public access and local laws and
or adjacent properties;and similar ordinances
activities. Comply with City policy PA-3.
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NCS000249 Stormwater Management Plan November 2023

Notify public of other opportunities to
participate
(f)Standard Written Standard Operation Annually Review memo
Operating Procedures in place and reviewed complete?Yes/no
Procedures annually
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NCS000249 Stormwater Management Plan November 2023

5 Illicit Discharge Detection and Elimination
5.1 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 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 1,
Paragraph 1 (1)(2).
Table 17 contains a summary of the BMPs used to identify and eliminate illicit discharges and connections
in the City of Durham. Specific methods and practices may be found in the program's internal guidance
documents which are available upon request. These documents are periodically reviewed and updated as
necessary.
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NCS000249 Stormwater Management Plan November 2023

Table 17. BMP Summary Table for the IDDE Program
BMP Description Measurable Goals Schedule for Reporting Metric
Implementation
(a) Maintain Maintain adequate ordinances or other Continuous Municode website
appropriate legal legal authorities to prohibit illicit contains current
authorities connections and discharges and enforce Ordinance and tracks all
the approved IDDE program. revisions.
(b) Maintain a Storm Maintain a current map showing major Continuous Summary of map updates
Sewer System Base outfalls and receiving streams. including MS4 nodes and
Map of Major MS4 pipes
Outfalls
(c) Inspection/ Maintain written procedures and/or SOPs Annually Annual Outfall Screening
Detection Program for detecting and tracing the sources of Plan.
to Detect Dry illicit discharges and for removing the
Weather Flows at sources or reporting the sources to the
MS4 Outfalls State to be properly permitted.Written
procedures and/or SOPs shall specify a
timeframe for monitoring and how many
outfalls and the areas that are to be
targeted for inspections.
(d) Employee Conduct training for appropriate municipal Annually and as Dates of training and
Training staff on detecting and reporting illicit needed number of trainees
connections and discharges. IDDE field audit dates
(e) Maintain Public Maintain and publicize reporting Continuous Number of reports
Reporting mechanism(s)for the public to report illicit received across all
Mechanisms connections and discharges. communication modes
(f) Documentation Document the date of any investigations, Continuous Number of initial
any enforcement action(s)or remediation investigations conducted,
that occurred. Number of follow-up
investigation tasks, Number
of NOVs/NORs issued,
Number of outfalls
inspected
Summary of all
investigations and
enforcement documented
in Annual Report
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NCS000249 Stormwater Management Plan November 2023

5.2 Maintain Appropriate Legal Authorities
Durham City Code Chapter 70, Article 5 is known as the Stormwater Management and Pollution Control
Ordinance. An up-to-date version with records of all updates may be found at this web address:
https://library.municode.com/nc/durham/codes/code of ordinances?nodeld=PTIICOOR CH70UT ARTVST
MAPOCO
This ordinance prohibits illicit discharges and connections to the MS4 and establishes authority for the City
to protect the MS4 and surface waters through investigation, inspection, and enforcement action.
5.3 Maintain a Storm Sewer System Base Map of Major MS4 Outfalls
City GIS personnel continuously maintain and update a geodatabase of stormwater drainage system
features including pipes, channels, SCMs, and structures (inlets, outfalls, etc.). These features are publicly
available for inspection at this web address: https://maps.durhamnc.gov/gomaps/.
Water Quality staff use this and other geodatabases both in office and in the field to target dry weather
screening efforts and inform IDDE investigation work. A summary of MS4 feature edits and updates is
provided in the Annual Report.
5.4 Inspection/Detection Program to Detect Dry Weather Flows at MS4 Outfalls
Dry weather outfall screening is typically conducted by Water Quality during the October-February and July-
August months. The October-February months are the chief period for conducting most screenings each year
because undergrowth and brush have receded, making outfall access more achievable.
Screening is conducted according to the Description, Guidelines, and Procedures for Dry Weather Outfall
Screening document.
Annual Plans for dry weather screening are developed annually and presented at a pre-season Screening
Meeting. The Annual Plan addresses the following items:
• Target subwatershed(s)and reason(s)for selection
• Performance goals for outfall screening staff
• Specific outfalls to be screened (including GIS shapefile for reference)
• Field measurement requirements
• Laboratory sample collection and delivery directions
• Special project directives, as necessary
Collected field data are stored in the Outfall Screening database and may be readily queried and reported
out. A summary of outfall screening activities and findings is provided in the Annual Report.
5.5 Employee Training
New technical staff hired to implement the IDDE Program must have at minimum a two-year degree in a
science-related field, plus two years of related experience. Initial training of new staff includes
guidance/methods 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.
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NCS000249 Stormwater Management Plan November 2023

Annual formal training in each program area (investigations, outfall screening, and inspections)typically
requires half-day sessions and includes written testing to assess understanding.
Training of IDDE staff is documented in the Annual Report.
Annual audits of field operations are conducted to gauge the effectiveness of training and guidelines. Dates
of these audits are documented in the Annual Report.
5.6 Maintain Public Reporting Mechanisms
The Water Quality Unit is organized to receive pollution reports in a variety of ways to provide flexibility for
users to report potential violations and to ensure that staff can receive the complaints in a timely manner.
Available reporting methods include:
• Stormwater Pollution Hotline, (919)560-SWIM [79461
• Public Works Phone Directory, [phone]
• Water Quality Unit Email Address,[e-mail]
• Pollution Reporting Web Form via the Stormwater Division website
• Durham One Call Hotline, (9191) 560-1230
A summary of all reports received and investigated across all methods is provided in the Annual Report.
5.7 Documentation
Water Quality investigates reported releases of non-stormwater substances to the drainage system, surface
waters, or both. WQ also investigates reported releases that are imminent threats to the drainage system,
surface waters, or both.
All investigations are conducted according to the procedures in the Description, Guidelines, and Procedures
for Illicit Discharge Detection and Elimination (IDDE) Investigations document.
All information and evidence material to an IDDE investigation is stored in our Investigations Database,
where it may be queried and reported out. Investigation details can be provided upon request. A summary
table of all investigations, results, and enforcement actions is provided in the Annual Report.
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NCS000249 Stormwater Management Plan November 2023

6 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.
The North Carolina program to address the impacts of construction site runoff 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 authority over projects regulated by delegated programs operated
by Durham County and the Department of Transportation.
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NCS000249 Stormwater Management Plan November 2023

6.1 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.
The Durham County Board of Commissioners adopted a Sedimentation Commission-approved ordinance on
September 10, 1984,. 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. The interlocal agreement was updated in February
2023.
The City-County UDO includes the most current local erosion and sedimentation control regulations. The LIDO
provisions applicable to sedimentation and erosion control are primarily found in Sections 3.8, 12.10, 15.1,
and 15.5 of the Unified Development Ordinance. Steep slope provisions of the UDO are found in Section 8.8.
Definitions are found in Section 16 of the UDO.
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. 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. Program
review is facilitated by an internal database to track project reviews and site inspections. A summary of
applications is provided in the Annual Report.
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.
6.2 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.
6.3 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.
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.
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NCS000249 Stormwater Management Plan November 2023

7 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 threshold3
(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. 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.
Table 18 summarizes the BM Ps used to meet the objectives of the Post-Construction Stormwater
Management Program. The following sub-sections further explain the management measures
intended to meet this requirement.
3 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.
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Table 18. BMP Summary Table for the Post-Construction Stormwater Management Program
BMP Description Measurable Goals Schedule for Reporting Metric
Implementation
(a) Post-Construction Maintain an ordinance(or similar Continuous Ordinance revision date
Stormwater regulatory mechanism)that authorizes a Brief description of revisions
Management program to address stormwater runoff
Program from new development and
redevelopment to the extent allowable
under State law
Maintain the Reference Guide for Continuous SCM Design Manual and/or addendum
Development and City of Durham revision date
Addendum to the NC DWQ Stormwater
Best Management Practices(BMP) Brief description of changes advised in
Letter to Industry
Manual
Continue to implement the City's Continuous Type and number of reviews performed
stormwater development review process,
which includes site plan and construction
drawing review,to ensure compliance
with the ordinance and SCM design
standards.
Maintain the City's stormwater SCM as- Continuous Number of SCM as-built certifications
built approval process. reviewed and approved
Further improve and add additional Periodically, as Technical/functional updates planned
functionality to the Stormwater Control needed with schedule for implementation
Measure(SCM)Tool ("the Tool").
Train Stormwater Development Review Continuous List of training staff has participated in
staff
(b)Strategies which Maintain strategies that include a Continuous;see (d) See(a)above
include BMPs combination of structural and/or non- below Number of NORRs issued.
appropriate for the structural SCMs implemented in
MS4 concurrence with (a)above. Provide a
mechanism to require long-term
7-44

BMP Description Measurable Goals Schedule for Reporting Metric
Implementation
operation and maintenance of structural Number of annual SCM maintenance
SCMs. Require annual inspection reports inspection certifications submitted and
of permitted structural SCMs performed assessed
by a qualified professional
Require Stormwater Impact Analysis for Continuous Number of site plans and construction
each development project drawings reviewed as both submittals
require SIAs
Require treatment for pollutants(in Continuous Number of site plans and construction
addition to nitrogen and phosphorus) in drawings reviewed in the Third Fork
areas for which Total Maximum Daily Creek and Northeast Creek watersheds
Loads(TMDLs) have been established for
those pollutants
Within 12 months of the effective date of Year 1 of permit Review date(s) of stormwater
this permit,the permittee shall evaluate, cycle regulations and SCM design standards
and revise as needed,SCM with evaluation notes
requirements,to be at least as stringent Date of letter to industry notifying of
as the minimum requirements in 15A revisions to Reference Guide for
NCAC 02H .1000.
Development
(c) Deed The permittee shall provide mechanisms Continuous Number of plats and CC&Rs reviewed
Restrictions, such as recorded deed restrictions, plats,
Protective Covenants and/or protective covenants so that
development activities maintain the
project consistent with approved plans
Use recorded conservation easements to Continuous Number of plats reviewed.
protect property
(d)Operation and The developer shall provide the permittee Continuous Number of annual SCM maintenance
Maintenance Plan with an operation and maintenance plan inspection reports received and
for the stormwater system, indicating the assessed
operation and maintenance actions that
shall be taken,specific quantitative
7-45

BMP Description Measurable Goals Schedule for Reporting Metric
Implementation
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 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 Continuous Number of plats reviewed
ordinance, require a recorded plat or
alternative mechanism signed by the
property owner(s)that acknowledges
long-term operation and maintenance
For each completed structural SCM Continuous See (d)above
required by ordinance, require an Number of annual SCM maintenance
operation and maintenance plan, i.e.
inspection reports received and
0&M Manual,which lists specific assessed
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
7-46

BMP Description Measurable Goals Schedule for Reporting Metric
Implementation
Require annual inspection reports of Continuous Number/percent of SCMs performing
permitted structural SCMs performed by annual inspection and submitting
a qualified professional inspection report per assigned annual
inspection month
Conduct annual quality assurance Continuous Percent of SCMs submitting annual
inspections on a portion of all reports, inspection report receiving an additional
including at least one from each certified QA inspection
inspector submitting reports
(e) Educational Provide educational materials and Continuous See Stormwater Development Review
materials and training for developers. New materials Webpage
training for may be developed by the permittee, or Number of development seminars held
developers the permittee may use materials adopted for the development Community
from other programs and adapted to the
permittee's new development and
redevelopment program
Conduct seminars for engineers, Semiannually, or as List of workshop dates and number of
architects,and developers at least twice needed attendees
a year
Distribute information on post- Periodically Communication topics and number of
construction program changes via the emails sent
"Development Community"e-mail list
Conduct voluntary SCM handoff meetings Periodically: as Number of SCM handoff meetings
with developers and Homeowner's requested by conducted
Associations of single-family residential subdivision
subdivisions developer and HOA
7-47

7.1 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.
7.2 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
stormwater discharges. Water supply watershed protection requirements meet or exceed requirements of
15A NCAC 2B.0624. The City's Neuse River Stormwater Ordinance complies with 15A NCAC 2B.0711
(previously under .0235). Together, the Water Supply Overlay and Neuse Stormwater ordinance covered
approximately 60% of the City, as shown in Figure 4. City of Durham Post-Construction Stormwater
Treatment 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 were
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.
On May 1, 2023, the ordinance was modified to include revised standards for the re-adopted Neuse Nutrient
Strategy(15A NCAC 02B .0711).
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
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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.
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 19
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 19.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
7-49

I
I
I �
I
LEGEND
Streams
r
Neuse-Cape Fear Boundary
Watershed Boundary
y, Durham City Limits
®Durham City Jurisdiction
-_ County Boundary
C t Nutrient Management Strategy
Falls
I� Neuse(not Falls)
f > Water Supply Watershed
-WSWS:E-A
-WSWS:E-B
-WSWS:FIJ-A
-WSWS:F/J-B
- WSWS:MILR-A
-WSWS:M/LR-B N
PM Phase 2-City
n
NPhase 2 MS -County
0 1.5 3 6
Miles
,r a
r a Post-construction Limits on Nutrient Yield
Research Triangl Neuse R 3.6 lb-Nlacrelyear P-Not Required
Park(outside Cit Falls Lake 2.2 lb-Nlacrelyear 0.33 lb-Placre/year
'City Jursdiction as of 02/01/2019 '
Figure 4.City of Durham Post-Construction Stormwater Treatment
Nutrient yield limits on nitrogen and phosphorus under the ordinance are shown in Figure 4 and Table 20.
7-50

Table 20. 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 was required in the Lower
Neuse Basin until May 1, 2023, when the City adopted the revised City Code revisions for the Neuse nutrient
sensitive waters management strategy. With the adoption of the May 1, 2023 ordinance, the City now
requires the use of SNAP v4.2 in the Lower Neuse Basin, in alignment with the the State's adoption of SNAP
v4.2.
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 generally less
stringent than those of the Stormwater Performance Standards for Development.
The City will continue to implement and enforce these ordinances, making text revisions as needed for
clarity, legal purposes, etc.
7.3 SCM Design Standards
To regulate stormwater control measure design and construction,the City of Durham currently utilizes the
following:
• The 2007-2016 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/about/divisions/energy-mineral-land-resources/energy-mineral-
land-permit-guidance/stormwater-bmp-manual/archive.
• 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.
7.4 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
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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.
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/equivalents 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
Plats, 10.4.04.00002 -Stormwater Review of Rezoning Plans, and 27.21.04.00004 - Logging in Submittals
Stormwater Development Review .
7.5 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 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-?bidld= .
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
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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:
• 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.
The current SCM permitting process can be found in Section 8.2.2 of the Reference Guide for Development.
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. Beginning May 1, 2023, 1-year detention is required only if the
development requires an SCM to comply with higher order storm detention and/or pollutant standards. 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.
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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
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. With
the adoption of SNAP v4.2 and the revisions to the City Code effective May 1, 2023 to reflect the readopted
Neuse Management Strategy; SNAP v4.2 is now utilized in both the Falls and Neuse Basins.
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 a primary SCM or an SCM(s)that remove(s) 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 2007-2016 edition of the NC Stormwater BMP Manual, when an
SCM for pollutant removal is required.
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 Nutrient Sensitive Waters (NSW) Protection Measures (for programs with development or
redevelopment draining to NSW waters)
As discussed above in Section 7.2, 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
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• 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 2020
readopted Neuse Nutrient Strategy requires amended City Code language adoption by May 1, 2023. 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.
As shown in Figure 4, 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 May of 2019, adherence to
rules associated with the Jordan Lake Nutrient Sensitive Water Strategy was 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 were 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 until the
Jordan Nutrient Strategy rule is legally effective and an annual reporting requirement is included in it, 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.
7.7 Deed Restrictions and Protective Covenants
SCMs are constructed as part of private property developments. The City uses recorded plats or alternative
instruments and City Code requirements for all projects, as well as Declaration of Covenants, Conditions &
Restrictions (CC&Rs)for all limited residential or mixed-use projects to indicate restrictions that convey with
a property. Projects completed under the pre-May 20, 2019 ordinance still require Stormwater Facility
Agreements (a.k.a. Operation and Maintenance Agreements). Chapter 70 Articles X and XI of the City Code
and UDO Section 8.7 require financial guarantees necessary for the construction, operation, and
maintenance of SCMs. For limited residential development, requirements in Section 8.2 of the RGD
explicitly require an Owner's Association, specific CC&R language to ensure that a development project will
continue to be operated and maintained consistent with approved plans and City requirements.
Impervious surface limits are required to be shown on recorded plats in watershed protection overlays 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.
7.8 Operation and Maintenance
For each development project with one or more stormwater SCMs,the City's Stormwater Performance
Standards for Development Ordinance requires:
• That it 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" (htti3s://durhamnc.gov/DocumentCenter/View/2239/Owners-
Maintenance-Guide-for-Stormwater-BMPs-PDF?bidld=), and
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• That it provide for the construction and long term 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.
The City ordinance requires sealed annual maintenance certifications (inspection reports)for all SCMs
constructed and approved. The inspection report is a sealed certification by an NC Professional Engineer or
NC registered landscape architect who has been certified by the City as an SCM 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 Services through the
[e-mail] 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; and
• Inspection and maintenance records, which should be kept with the owner/responsible party.
In case of failures/deficiencies,the City continues to require an SCM 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 25% of all reports. The selection of the 25% ensures that each SCM 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-Builts-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 "Stormwater Performance Standards for Development-
Stormwater Control Measure Compliance and Enforcement Guidelines"
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 Services staff conduct annual maintenance inspections of municipally-owned or maintained
structural SCMs to verify conditions, operational issues, and maintenance needs. These assessments are
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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.
7.9 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 .O126(1O)(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 O213.O267 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 http://durhamnc.gov/414/.
7.10 Educational Materials and Training for Developers
The City provides educational materials and training for developers in the following ways:
• Minimum of 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.gov/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.p-ov/905/. Letters to Industry policy documents are posted at
http://durhamnc.p-ov/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.
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8 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.
Table 21 below summarizes the BMPs implemented and maintained 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 21: BMP Summary Table for Pollution Prevention and Good Housekeeping for Municipal Operations.
BMP Description Measurable Goals Schedule for Reporting Metric
Implementation
Maintain an inventory of municipal
facilities and operations owned and
operated by the permittee that have Inventory table of
(a) Inventory of municipal facilities
municipal facilities been determined by the permittee to Ongoing
and operations have significant potential for generating Inventory table of
polluted stormwater runoff. Also
maintain an inventory of municipally municipal SCMs
owned structural SCMs.
Implement an inspection and
maintenance program for facilities and
operations owned and operated by the
permittee for potential sources of
polluted runoff, including stormwater
controls and conveyance systems. The
(b) Inspection and inspection program shall evaluate
maintenance pollutant sources, document Summary table of all
program for deficiencies, plan corrective actions, Ongoing
inspections
municipal facilities implement appropriate controls,and
and operations document the accomplishment of
corrective actions. The maintenance
program shall include maintenance
activities and procedures aimed at
preventing or reducing pollutants
generated from municipal facilities and
operations.
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BMP Description Measurable Goals Schedule for Reporting Metric
Implementation
Maintain and implement Site Pollution
Prevention Plans for municipal facilities
(c)Site Pollution owned and operated by the permittee Summary of facility
that have been determined by the
Prevention Plans for Ongoing SPPP implementation
municipal facilities. permittee to have significant potential status
for generating polluted stormwater
runoff that has the goal of preventing or
reducing pollutant runoff.
Maintain spill response procedures for Summary of facility
(d)Spill Response municipal facilities and operations SPPP implementation
Procedures for owned and operated by the permittee status
municipal facilities that have been determined by the Ongoing Spill response
and operations permittee to have significant potential procedures are
for generating polluted stormwater addressed in facility
runoff. SPPP.
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BMP Description Measurable Goals Schedule for Reporting Metric
Implementation
Describe measures that prevent or
minimize contamination of the
stormwater runoff from all areas used for
vehicle and equipment cleaning,
including fire stations that have more
than three fire trucks and ambulances.
Perform all cleaning operations indoors,
cover the cleaning operations, ensure
wash water drains to the sanitary sewer
system, collect wash water and
stormwater run-on from the cleaning
area and provide treatment or recycling,
or other equivalent resources. If sanitary
sewer is not available to the facility and
cleaning operations take place outdoors,
wash water shall drain to an SCM for
treatment, or else the cleaning
(e) Prevent or operations shall take place on or drain Number and location of
minimize directly to grassed or graveled areas to compliant cleaning
contamination of prevent point source discharges of the areas
stormwater runoff wash water into the storm drains or Ongoing
from all areas used surface waters. Vehicle and equipment
for vehicle and cleaning addressed in
equipment cleaning Where cleaning operations cannot be facility SPPPs
performed as described above and when
operations are performed in the vicinity
of a storm drainage collection system,
the drain is to be covered with a portable
drain cover during cleaning activities.
Any excess standing water shall be
removed and properly handled prior to
removing the drain cover.
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
limitation shall incorporate structural
measures during facility renovation to
the extent practicable.
The permittee shall implement BMPs to
(f)Streets, roads, and reduce polluted stormwater runoff from Summary tables of
public parking lots municipally-owned streets, roads, and Ongoing street sweeping and
maintenance public parking lots within the corporate parking lot cleaning.
limits.
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BMP Description Measurable Goals Schedule for Reporting Metric
Implementation
(g) Inspection and The permittee shall maintain and
maintenance (I&M) implement an inspection and Summary table of all
for municipally-owned maintenance program for stormwater SCM inspections
or maintained control measures(SCMs)owned and Ongiong
stormwater control operated by the municipality and the Summary table of MS4
measures(SCMs) municipal storm sewer system (including inspections and
and the storm sewer catch basins,the conveyance system, cleaning
system and SCMs).
Maintain and implement a training plan
(h)Staff training Annually
that indicates when, how often, and who Dates of trainings and
is required to be trained and what they number of trainees
are to be trained on.
8.1 Inventory of municipal facilities and operations
The City maintains a database for tracking facilities information, inspection priority, inspection results,
compliance status, and enforcement actions. The database includes both municipal and private facilities. It
includes NPDES-permitted and non-regulated facilities. The database assigns 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 inspector's experience, and assessment of the
facility's risk of generating runoff pollutants. A facility's category may change over time based on fluctuations
in risk and the need for increased or decreased inspection frequency.
Further explanation of facility category assignment may be found in the City's Description, Guidelines, and
Procedures for the Stormwater Inspections Program document. A table summarizing the priority status of
each municipal facility is provided in the Annual Report.
8.2 Inspection and maintenance program for municipal facilities and operations
Our Inspections Database automatically generates lists of facilities due for inspection based on the date of
most recent inspection and priority category (frequency). All facilities are inspected by Water Quality
inspectors within plus or minus one month of their due date. A standard checklist is used for all inspections
to ensure consistency and thoroughness. A full description of inspection procedures and practices may be
found in the City's Description, Guidelines, and Procedures for the Stormwater Inspections Program
document.
Multiple municipal facilities have NPDES Industrial Stormwater permits. Each of these facilities has a SPPP
and Pollution Prevention Team (PPT). The facility PPTs are responsible for conducting all permit-required
measures, including self-inspections, runoff monitoring, BMP implementation, and program review. Water
Quality inspectors conduct additional inspections of these NPDES permitted facilities together with members
of the PPT.
A table summarizing the dates and results of municipal facility inspections is provided with the Annual
Report.
8.3 Site pollution prevention plans for municipal facilities
All municipal facilities that are either NPDES-permitted or have the potential to contribute contaminants to
the stormwater drainage system are required to develop and implement Stormwater Pollution Prevention
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Plans. The City's Description, Guidelines, and Procedures for the Stormwater Inspections Program document
outlines content required in a SPPP. A table summarizing SPPP implementation status at each facility is
provided in the Annual Report.
8.4 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 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 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 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.
8.5 Prevent or minimize contamination of stormwater runoff from all areas used for vehicle and
equipment cleaning
Municipal cars and light duty trucks are cleaned at a third-party commercial car wash facility. For more
demanding cleaning, the City uses two wash pits at the Public Works Operations Center, a bay at the Solid
Waste Truck Wash, a bay for busses at the Go Durham maintenance center, and an indoor wash area at the
Parks and Recreation Operations and Maintenance facility. Wastewater from vehicle washing at these pits
and bays is directed to the sanitary sewer system.
Emergency vehicles must stay close to their assigned service area to meet response time goals. The Fire
Department continues to comply with the City's MS4 NPDES permit rule governing the washing of emergency
vehicles. The Stormwater Division and Fire Department evaluate station renovation plans as they arise. 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.
8.6 Streets, roads, and public parking lots maintenance
The City of Durham continuously implements an operations and maintenance program for the municipal
stormwater system. Detailed program goals, activities and procedures, schedules, documentation, staff
responsibilities, and evaluations may be found in the City's Stormwater Infrastructure Operation and
Maintenance Plan.
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The above plan includes details for the following programs:
• Drainage conveyance system asset management
• Drainage conveyance system contract inspection and cleaning
• Street sweeping
• Parking maintenance
• Stormwater Control Measure (SCM) inspection and maintenance
Metrics including curb miles swept, pounds of street particulates removed, and frequency/type of parking lot
maintenance are included in the Annual Report.
8.7 Inspection and Maintenance (I&M)for municipally-owned or maintained stormwater control
measures and the storm sewer system
As above, see the Stormwater Infrastructure Operation and Maintenance Plan for specific program details.
Metrics including number of catch basins cleaned, linear feet of pipe inspected and cleaned, and number of
SCMs inspected are included in the Annual Report.
Inspection of privately owned structural SCMs and inspection and maintenance of city-owned structural
SCMs are addressed in Section 7.8 Operation and Maintenance.
8.8 Staff Training
Work groups throughout the City are trained in a combination of pollution prevention, spill response, and
IDDE reporting according to the nature and/or location of their work. The Water Quality Pollution Prevention
Coordinator uses video resources, PowerPoint presentations, handouts, and written guidance materials to
cover topics for each audience. Training sessions include pre-training and post-training quizzes to document
learning. A self-paced presentation has been developed for orientation of new employees, with quizzes to
document learning.
Work groups are assigned and trained according to their priority level. 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 continues on a rolling basis as new
employees are hired.
Records of all training sessions, including attendance, topics covered, materials distributed, and quiz scores
are maintained in the Stormwater Inspections Database. A summary of staff training is provided in the
Annual Report.
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9 Program to Monitor and Evaluate Stormwater Discharges to Municipal Systems
The objective of this program is to evaluate pollutants in stormwater discharges to the City's MS4 from:
hazardous waste treatment, disposal, and recovery facilities; industrial facilities subject to Section 313 of
Title III of the Superfund Amendments and Reauthorization Act of 1986; and industrial facilities determined
to be contributing or have potential to contribute a substantial pollutant loading to the MS4.
The City of Durham continues to implement a facilities inspections program, authorized under City Code
Section 70-525. In addition to the enforcement powers further specified in City Code Sections 70-538
through 70-542.
The table below summarizes the BMPs implemented and maintained to meet requirements to monitor and
control pollutants entering the municipal system.
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Table 22. BMP Summary Table for Monitoring and Control of Pollutants Entering the MS4
B Schedule for Reporting
MP Measurable Goals
Implementation Metric
(a) Maintain an Maintain a database inventory of: permitted hazardous Continuous Summary table
Inventory of waste treatment, disposal and recovery facilities; of all inventoried
Industrial industrial facilities that are subject to Section 313 of facilities
Facilities Title III of the Superfund Amendments and Summary table
Reauthorization Act of 1986(SARA); and industrial
of new facilities
facilities identified with an industrial activity permitted added to
under 40 CFR 122.26 that discharge storm water to the
permittee's MS4. inventory
(b) Inspection Identify priorities and inspection procedures. Priority Annually Summary table
Program facilities include those identified above,at a minimum. of facility
prioritization
status
Summary of
procedures
review and
updates
(c) Evaluate For permitted facilities,the municipality shall establish Continuous Summary table
Industrial procedures for reporting deficiencies and non- of all
Facilities compliance to the permitting agency. Where inspections
discharging compliance with an existing industrial stormwater conducted
stormwater to the permit does not result in adequate control of pollutants
City's MS4 to the MS4,the municipality will recommend and
document the need for permit modifications or
additions to the permit issuing authority.
The permittee is required to evaluate control measures
implemented at permitted hazardous 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.
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.
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9.1 Maintain an Inventory of Industrial Sites
The Inspections Program maintains a database to store general information, inspection results, compliance
status, and ordinance enforcement details for each private industrial facility within the City limits. The
database is used to track and schedule inspections. This database is regularly reviewed and updated to
improve utility.
The City's facility inventory 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 Water Quality Investigation database(IDDE program records)to identify facilities
associated with illicit discharges.
NPDES
Stormwater
Permitted
36
4
SARA Title III
1 1
No Permit No Exposure
Required
402 27
Figure 5. Example Venn Diagram Representation of Industrial Facility Inventory
Detailed methods for identifying and inventorying facilities for inspection may be found in the Description,
Guidelines, and Procedures for the Stormwater Inspections Program document.
Facility inspections are conducted according to a priority ranking system. Every facility is assigned a priority
level reflecting a combination of risk of stormwater pollution and history of compliance with stormwater
regulations. This system allows us to focus on those facilities most in need of oversight, corrective action, or
both.
Private facilities are inspected according to the following hierarchy:
• Facilities requiring follow-up inspection
• High Priority- high risk and/or recent history of non-compliance, annual inspection
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• Medium Priority - lower risk, inspected every two years
• Low Priority - lowest risk, inspected every three years
• No Exposure - NCDEQ has issued No Exposure Certification, inspected every five years
• No Inspection Needed - no storage of pollutants or pollutant-generating activities
The stormwater inspections database tracks a facility's priority rank and automatically assigns the proper
inspection frequency. Automated database reports generate a current listing of facilities due for inspection
based on priority, inspection frequency, and time since most recent inspection.
A full breakdown of the inventory, by facility type and priority ranking, is provided as a table in the Annual
Report.
9.2 Inspection Program
The City follows written procedures in conducting the inspection program. These procedures are detailed in
the Description, Guidelines, and Procedures for the Stormwater Inspections Program document. As the
inspection program continues to evolve, procedures are reviewed and updated as necessary. A summary of
reviews and major updates is provided in the Annual Report.
A standard checklist is used for all inspections to ensure consistency and thoroughness. A full description of
inspection procedures and practices may be found in the City's Description, Guidelines, and Procedures for
the Stormwater Inspections Program document.
When City Code violations are evident, inspectors engage in code enforcement according to the procedures
defined in the Guidelines for Enforcement of the Stormwater Management and Pollution Control Ordinance
document.
A summary table of all inspections, results, and enforcement actions is provided in the Annual Report.
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10 Water Quality Assessment and Monitoring
This Water Quality Assessment& Monitoring 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
October 10, 2018. The objective of this section of the permit is to "evaluate the impacts of MS4 discharges
on surface water quality." Additional requirements in the Water Quality Assessment and Monitoring Plan are
as follows:
Table 23. BMP Summary Table for Water Quality Assessment and Monitoring Program
BMP Measurable Goal Schedule for Reporting Metric
Implementation
(a)Water Quality Maintain a Water Quality Continuous Annual ambient stream
Assessment and Assessment and Monitoring Plan. chemistry monitoring plan
Monitoring Plan The Plan shall include a schedule
for implementing the proposed Annual benthic
assessment and monitoring macroinvertebrate monitoring
activities. plan
Executed contract with USGS
for operation and maintenance
of rainfall and stream
stage/discharge gages
(b)Water Quality Maintain and implement the Water Annual Annual table of ambient
Monitoring Quality Assessment and chemistry sites with
Monitoring Plan submitted to summarized water quality
DEMLR. information
Annual
Annual table of benthic
monitoring sites with
bioclassification ratings
USGS contract is
biennial,with plans to Daily rainfall and discharge
change to triennial or reported on the USGS website
every 3 years.
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.
10.1 Assessment
The Stormwater Division of the Public Works Department implements assessments of water quality data to
meet several goals. Results from these assessments help the Stormwater Division evaluate water quality in
Durham's MS4 and streams. These assessments identify, quantify and describe pollution and pollution
sources within the City of Durham.
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The Stormwater Division has performed many assessments in the past. These have been reported in
previous annual NPDES reports and summarized in the State of Our Streams report since 2004. These
assessments incorporate quality assurance into their implementation to ensure that program goals can be
met. Quality assurance includes the review of the assessment objectives, review of the sampling design, and
preliminary data review (EPA 2002).
Currently, assessments are conducted to meet the goals listed in the two tables below. The core program
goals have not changed from past years; these goals have been assessed regularly since 2004. 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 depending upon many factors, including
resources available for the assessment, software availability, monitoring data, and the goal it is supporting.
Assessments of past conditions may not be possible depending on data availability. Descriptions of
assessments are contained within QAPPs and SOPs, including those for outfall screening(Stormwater& GIS
Services 2022a), investigations (Stormwater& GIS Services 2022b), and inspections (Stormwater& GIS
Services 2022c).
Table 24.Assessment Program Core Goals
Core Goals Type(s)of Assessment
Identify illicit discharges to area streams 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 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, like
ambient stream monitoring,when the technician has reason to
suspect an illicit discharge.
Identify pollution problem areas within the City of Two different types of assessments may be performed to identify
Durham 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 where pollution may have reached 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.
Assess compliance with state water quality Assessments associated with this goal involve comparing
programs, including TMDLs,water quality standards, conditions monitored in Durham to state and federal water quality
and nutrient management strategies program targets when appropriate. In some 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 other cases,where the state
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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.
Table 25.Assessment Program Supplemental Goals
Supplemental Goal Type(s)of Assessment
Identify overall water quality trends Observing improvements in water quality over time is the goal for
Durham's streams.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 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.
Determine pollution removal credits Determining pollution removal credits was 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.
Programs in the Stormwater Division may be evaluated to determine
pollution removal credits, including Illicit discharge elimination and
retrofits.
Assess the overall quality of streams within the City The goal of this assessment is to determine the general status of
of Durham water quality of streams in the City of Durham.Assessments can
include evaluation of average conditions in a stream and
examination of water quality, streamflow,sediment, and benthic
macroinvertebrate data. Interpretation of impacted parameters in a
stream may suggest the influence/presence of certain types of
pollution sources present in the watershed draining to the stream.
Evaluate the water quality impacts of urban All assessments listed above contribute to this goal.The way the
stormwater on area streams 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 storm drainage system
and ultimately area creeks when these activities do not comply with
local ordinances.
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10.2 Ambient Stream Monitoring
The Ambient Stream Monitoring program supports the following assessment goals:
• Identify pollution problem areas within the City.
• Assess compliance with State water quality programs, including TMDLs,water quality standards, and nutrient
management strategies.
• Identify overall trends to water quality.
• Determine pollution removal credits.
• 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 Stormwater Division not only the opportunity to evaluate streams independently of the
State, but also to verify results obtained by the State.
Similar to the INC Division of Water Resources (DWR)Ambient Monitoring System, The City of Durham's
Stormwater Division uses a rotating watershed approach, with comprehensive chemical and biological
monitoring in each basin occurring every two years as shown in Table 26. 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 is monitored
every year for water chemistry and hydrology due to their use in calculating loading for certain parameters of
concern.
Table 26. Rotating Monitoring Schedule for Water Chemistry Monitoring
Neuse River Basin Cape Fear River Basin
Watersheds Watersheds
Odd Years Ellerbe Creek, Panther Creek, Crooked Creek, Little Creek, New
Stirrup Iron Creek Hope Creek
Even Years Eno River, Lick Creek, Little Lick Northeast Creek,Third Fork
Creek, Little River Creek
Figure 6 shows the monitoring cycle. One full monitoring cycle includes the planning, monitoring,
summarizing and reporting of monitoring data. This is generally accomplished in 20 months. The Stormwater
Division re-evaluates the monitoring program near the middle of each calendar year. Existing monitoring
sites are reviewed to determine if any should be added, 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 Division website. Staff of the Water
Quality Unit of the Stormwater Division work to ensure that scheduled monitoring and reporting is
completed.
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Develop Publish State of
reportmonitoring Our Streams
plan annual re-sults pr 'A 'A'
Summarize 11L
Approxlmately20 months
Figure 6. Monitoring Cycle
10.2.1 Water Chemistry
The ambient water chemistry portion of the ambient monitoring program focuses on surface water. Through
field or laboratory analysis of selected parameters, the ambient water 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). Reporting metrics: Annual ambient water
chemistry monitoring plan, annual water chemistry summary table, and State of Our Streams web pages.
10.2.2 Benthic Macroinvertebrate Community Assessments
The Stormwater Division 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 DWR benthic
macroinvertebrate program. Reporting metrics: Annual benthic monitoring plan, annual benthic monitoring
results, and State of Our Streams web pages.
10.2.3 Hydrologic Monitoring
The hydrology of City streams is monitored to understand pollution flows, sediment transport, and the impact
of hydrology on stream morphology and instream habitat.
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, stream stage, and rainfall. Groundwater
wells are not currently installed or monitored by the Stormwater Division. 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 stream discharge.The Stormwater Division obtains this type of information through a
variety of means, including partnerships with the NC State Climate Office and the US Geological Survey.The
Stormwater Division also operates a weather station that collects rainfall data.
• 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.
• 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 flood stage, a means to estimate
flow, and is useful in areas when flooding is a concern.Stream stage measurements in the City of Durham are
accomplished by the Stormwater Division and in partnership with the US Geological Survey.
Reporting metric: USGS web site.
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10.3 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, but can occur over longer periods as well.
Special studies 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, surveys of aquatic
weeds, measurement of pollution reduction measures and devices, and more traditional water quality
assessments.
Special studies may be generated from concerns or initiatives throughout the Stormwater Division. These
studies are vetted within the Water Quality Unit and if they are selected, a QAPP is written for the study.
Special studies may include contractors as well as technical staff from within the Stormwater Division. 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 indefinitely, but no
less than 10 years.
Reporting metrics: Study plans, QAPPs, and study reports, all available on the Stormwater Quality Special
Projects web site.
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11 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 an 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 the conditions of the permit
are met, including developing and implementing appropriate BMPs within the six minimum measures to
address the permittee's MS4 waste load allocation. The permit recognizes that improved water quality is the
expected outcome.
Table 27. BMP Summary Table for EPA-approved TMDL Waste Load Allocations for the City of Durham
BMP Measurable Goal Schedule for Reporting
Implementation Metric
(a) Identify, Within 12 months of an EPA-approved TMDL with Within 12 months of an See below
describe and a permittee waste load allocation the permittee EPA-approved TMDL
map watershed, shall prepare a plan that:
outfalls, and
streams
Identifies the watershed(s)subject to an approved Within 12 months of an Table 6 of
TMDL with an approved waste load allocation EPA-approved TMDL Stormwater
assigned to the permittee; Management
Plan updated
Includes a description of the watershed(s); Within 12 months of an TMDL Response
EPA-approved TMDL Plan-Part A
Includes a map of the watershed showing streams Within 12 months of an TMDL Response
and outfalls; EPA-approved TMDL Plan-Part A
Identifies the locations of currently known major Within 12 months of an TMDL Response
outfalls within its corporate limits with the EPA approved TMDL Plan-Part A
potential of contributing to the cause(s)of the and then Annually
impairment to the impaired segments,to their thereafter
tributaries, and to segments and tributaries within
the watershed contributing to the impaired
segments; and
Includes a schedule(not to exceed 6 months)to Within 12 months of an Stream walk
discover and locate other unknown major outfalls EPA-approved TMDL study plan or
within its corporate limits that may be contributing stream walks as
to the cause of the impairment to the impaired part of a
stream segments,to their tributaries,and to Watershed
segments and tributaries within the watershed Improvement
contributing to the impaired segments. Plan
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BMP Measurable Goal Schedule for Reporting
Implementation Metric
(b) Evaluate Within 12 months of an EPA-approved TMDL with Within 12 months of an See below
existing a permittee waste load allocation the permittee's EPA-approved TMDL,
measures plan shall: and reviewed as
needed or with each
permit cycle
Describe existing measures currently being Within 12 months of an NPDES Annual
implemented by the permittee designed to achieve EPA-approved TMDL Report,Section
the MS4's NPDES waste load allocation and to and Annually thereafter 11
reduce the TMDL pollutant of concern to the
maximum extent practicable within the watershed
to which the TMDL applies; and
Provide an explanation as to how those measures Within 12 months of an TMDL Response
are designed to reduce the TMDL pollutant of EPA-approved TMDL Plan-Part A
concern.
Continue to implement the existing measures until Within 12 months of an NPDES Annual
notified by the Division. EPA-approved TMDL Report,Section
and as appropriate 11
thereafter
(c)Assessment Within 24 months of an EPA-approved TMDL with Within 24 months of an NPDES Annual
of available a permittee waste load allocation the permittee's EPA-approved TMDL, Report
monitoring data plan shall include an assessment of the available and reviewed every five
monitoring data. Where long-term data is years thereafter
available,this assessment should include an
analysis of the data to show trends.
(d) Monitoring Within 24 months of an EPA-approved TMDL with Within 24 months of an Annual ambient
Plan a permittee waste load allocation the permittee EPA-approved TMDL, stream
shall develop a monitoring plan for the permittee's and reviewed with each chemistry
assigned NPDES regulated waste load allocation permit cycle monitoring plan
as specified in the TMDL.The permittee shall
maintain and implement the monitoring plan as
additional outfalls are 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 months of an See below
measures a permittee waste load allocation,the permittee's EPA-approved TMDL,
plan shall: and reviewed with each
permit cycle
Describe additional measures to be implemented Within 24 months of an TMDL Response
by the permittee designed to achieve the MS4's EPA-approved TMDL, Plan-Part B
NPDES waste load allocation and to reduce the and reviewed with each
TMDL pollutant of concern to the maximum extent permit cycle
practicable within the watershed to which the
TMDL applies;and
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BMP Measurable Goal Schedule for Reporting
Implementation Metric
Provide an explanation as to how those measures Within 24 months of an TMDL Response
are designed to achieve the MS4's NPDES EPA-approved TMDL, Plan-Part B
regulated waste load to the maximum extent and reviewed with each
practicable within the watershed to which the permit cycle
TMDL applies.
(f) Within 48 months of an EPA-approved TMDL with Within 48 months of an See below
Implementation a permittee waste load allocation,the permittee's EPA-approved TMDL,
plan plan shall: and reviewed with each
permit cycle
Describe the measures to be implemented within Within 48 months of an TMDL Response
the remainder of the permit term designed to EPA-approved TMDL, Plan-Part B
achieve the MS4's NPDES waste load allocation and reviewed with each
and to reduce the TMDL pollutant of concern to permit cycle
the maximum extent practicable;
Identify a schedule,subject to Division approval, Within 48 months of an TMDL Response
for completing the activities EPA-approved TMDL, Plan-Part B
and reviewed with each
permit cycle
Implement the permittee's TMDL plan Continuously Stormwater
NPDES Annual
Report
(g) Incremental The permittee's plan must outline ways to track TMDL Response
success progress and report successes designed to Plan-Part B
achieve the MS4's NPDES regulated waste load
allocation and to reduce the TMDL pollutant of Each permit cycle
concern to the maximum extent practicable within
the watershed to which the TMDL applies
(h) Reporting The permittee shall conduct and submit to the Annually Stormwater
Division an annual assessment of the program NPDES Annual
designed to achieve the MS4's NPDES waste load Report
allocation and to reduce the TMDL pollutant of
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 Response Plans that address the pollutant of concern through the
six minimum control measures satisfy the objectives of this section of the permit.
11.1 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 waste load 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
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measures were enhanced to reduce 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 28.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
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.
In early 2018 the Stormwater Division began 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
(Durham 2019a, Durham 2019b), replaced the previous WQRPs in these two creeks. The 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
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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 the
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 judgment 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 online at https:,//www.durhamnc.gov/4649/Technical-Reports.
The 2018 NPDES permit was issued concurrent with the development of the TMDL Response Plans. 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.
11.2 Future TMDL Response Plans
For EPA-approved TMDLs after 2018, the City will complete all required BMPS in Table 28 on the provided
schedule. BMPs required within the first 12 months of an EPA-approved TMDL will be reported in Part A of
the TMDL Response Plan. BMPs required after the first 12 months of an EPA-approved TMDL will be
reported in Part B of the TMDL Response Plan. Together, Part A and Part B will form the entire TMDL
Response Plan. 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), Little Lick, and New Hope Creeks, and the Eno River.
The Lick Creek, Stirrup Iron Creek, and Brier Creek watershed plan request for qualifications will be issued in
calendar year 2023.
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
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. A different approach will be needed when the potential
sources are diffuse or difficult to identify. Additional measures may focus on identifying the sources, the
pattern of discharge, and the geographic location.
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12 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.
Ibid. 2019a. Total Maximum Daily Load Response Plan for Fecal Coliform Bacteria in Northeast Creek (Cape
Fear River Basin), Durham, North Carolina. Stormwater& GIS Services, Water Quality Unit.
Ibid. 2019b. Total Maximum Daily Load Response Plan for Turbidity&Total Suspended Solids in Third Fork
Creek (Cape Fear River Basin), Durham, North Carolina, Durham, North Carolina. Stormwater& GIS
Services, Water Quality Unit.
Ibid. 2021. Standard Operating Procedures for Benthic Macroinvertebrate Community Monitoring.
Stormwater& GIS Services. Water Quality Unit. August.
Ibid. 2022a. Description, Guidelines, and Procedures for Dry Weather Outfall Screening. DRAFT- In Revision..
Stormwater& GIS Services, Water Quality Unit.
Ibid. 2022b. Description, Guidelines, and Procedures for Illicit Discharge Detection and Elimination (IDDE)
Investigations, Standard Operating Procedures.. Stormwater& GIS Services, Water Quality Unit. April
Ibid. 2022c. Description, Guidelines, and Procedures for the Stormwater Inspections Program. . Stormwater
& GIS Services, Water Quality Unit. March
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).
INC 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
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US Fish and Wildlife Services (USFWS). 2021a. Endangered and Threatened Wildlife and Plants: Threatened
Species Status with Section 4(d) Rule for Neuse River Waterdog, Endangered Species Status for
Carolina Madtom, and Designations of Critical Habitat. 86FR109:30688-30751 (June 9, 2021)
US Fish and Wildlife Service (USFWS). 2021b Endangered and Threatened Wildlife and Plants: Threatened
Species Status with Section 4(d) Rule for Atlantic Pigtoe and Designation of Critical Habitat. 86FR
218: 64000- 64053 (November 16, 2021)
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