J4-Third Fork Creek TMDL Response Plan_FINAL

Total Maximum Daily Load Response Plan for Turbidity & Total
Suspended Solids in Third Fork Creek (Cape Fear River Basin),
Durham, North Carolina
CITY OF
DURHAM
Prepared by the Public Works Department,
Stormwater & GIS Services Division
March 19, 2019
101City Hall Plata, Third Floor, Durham, NC 27701 919.560.4326 I DUrhamNC,gov follow Us @CftV0f0Urh0MNC

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
The City of Durham's Water Quality Group in the Division of Stormwater & GIS Services and the
Department of Public Works developed this TMDL Response Plan for the City of Durham. The City
would like to acknowledge contributions to this TMDL Response Plan from several City and County
government departments and divisions.
CITY OF DURHAM
City -County Planning
Code Enforcement
Landus Robertson
Public Works Department
Stormwater & GIS Services
Jonathan Baker
Michelle Woolfolk
J.V. Loperfido
Emily Rhode
Jim Azarelo
Patrick Hogan
Sandra Wilbur
Lance Fontaine
Laura Smith
Megan Walsh
Jennifer Buzun
Brajesh Tiwari
Water Management Department
Water & Sewer Maintenance
Kerry Sanford
Kenny Willard
Jeremy Farlow
DURHAM COUNTY
ACKNOWLEDGMENTS
Unified Development Ordinance
Mike Stock
Bo Dobrzenski
Danny Cultra
Operations
Phillip Powell
Bruce Woody
John Sandin
Mike Boyd
Industrial Waste Control
Tyrone Battle
Engineering and Environmental Services Department
Stormwater & Erosion Control Utilities
Ryan Eaves Stephanie Brixey
McKenzie Gentry
Public Health Department
Environmental Health
Patrick Eaton
Noelle Spence
Soil & Water Conservation District
Heather Dutra
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TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
Table of Contents
1.
Acronyms and Abbreviations........................................................................................................................... 4
2.
Executive Summary..........................................................................................................................................
5
3.
TMDL Response Plan Objective.......................................................................................................................
6
4.
Introduction and Background..........................................................................................................................
6
4.1. Watershed Information............................................................................................................................
8
4.2. Jurisdictional Responsibility...................................................................................................................11
5.
Pollutant Sources...........................................................................................................................................11
5.1. In -stream Sediment Sources.................................................................................................................12
5.2. Construction/Development Sources of Sediment................................................................................12
5.3. Runoff from Impervious Surfaces and Direct Discharge.....................................................................13
6.
Pollution Prevention and Mitigation Measures Currently Being Implemented...........................................13
6.1. Response Plan Measure Definitions.....................................................................................................13
7.
Newly Proposed Pollution Prevention and Mitigation Measures.................................................................16
7.1 Measures to Reduce In -stream Sediment Sources..............................................................................16
7.2 Measures to Reduce Construction Sources of Sediment....................................................................17
7.3 Measures to Reduce Other Sources of Sediment................................................................................18
8.
Prioritized Measures Applicable to the NPDES Six Minimum Measures....................................................21
8.1. Implementation of Plan to the Maximum Extent Practicable..............................................................21
8.2. Public Education and Outreach.............................................................................................................21
8.3. Public Participation and Involvement....................................................................................................21
8.4. Illicit Discharge Detection and Elimination...........................................................................................22
8.5. Construction Site Stormwater Runoff Control......................................................................................22
8.6. Post -Construction Stormwater Management........................................................................................23
8.7. Pollution Prevention/Good Housekeeping for Municipal Operations.................................................23
9.
Watershed Planning.......................................................................................................................................23
10. Water Quality Assessment and Monitoring...............................................................................................24
10.1. Water Quality Monitoring....................................................................................................................24
10.2. Turbidity Data and Computed TSS Loads.........................................................................................27
11. Water Quality Co -Benefits of TMDL Response Plan Implementation......................................................27
11.1. Value Added to Removal of Nutrients and Metals...........................................................................27
11.2. Benefits to Aquatic Life......................................................................................................................28
12. Steps Towards TMDL Response Plan Implementation............................................................................28
12.1. Response Plan Schedule by Agency..................................................................................................28
12.2. Tracking and Data Collection.............................................................................................................30
12.3. Re-evaluation of Response Plan........................................................................................................30
13. References..................................................................................................................................................30
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TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
14. Appendix A: Summary Table of All Proposed Measures (Priority and Non-Priority)................................32
15. Appendix B: Summary Table of Measures Not Included in the TMDL Response Plan ..........................35
16. Appendix C: Measure of Incremental Progress........................................................................................36
List of Tables
Table 1. Approved TMDL for the Third Fork Creek Watershed............................................................................. 8
Table 2. Measures currently implemented in the Third Fork Creek watershed................................................15
Table 3. Prioritized Measures in the Third Fork Creek watershed.....................................................................20
Table 4. NCDEQ 2016 Final 303(d) List (NCDEQ 2016), Category 5 Assessments for Third Fork Creek ........ 27
Table 5 Priority and non -priority measures proposed for the Third Fork Creek TMDL Response Plan.............32
Table 6. Measures considered and not currently feasible for implementation in the Third Fork Creek TMDL
ResponsePlan........................................................................................................................................................35
Table 7 Preliminary list of incremental progress.................................................................................................36
List of Figures
Figure 1. Map of the Third Fork Creek Watershed in City of Durham with the impaired segment shown in red.
................................................................................................................................................................................... 7
Figure 2. 2018 Existing Land Use in the Third Fork Creek watershed...............................................................10
Figure 3. Sediment generation, fate, and transport conceptual model.............................................................12
Figure 4. City of Durham, UCFRBA, and DWR ambient stream monitoring sites in the Third Fork Creek
watershed............................................................................................................................................................... 26
1. Acronyms and Abbreviations
■ CPV - Channel Protection Volume
■ CWEP - Clean Water Education Partnership
■ DWR - Division of Water Resources
■ EPA - Environmental Protection Agency
■ IDDE - Illicit Discharge Detection and Elimination
■ LA - Load Allocation
■ LID - Low Impact Development
■ NCAC - North Carolina Administrative Code
■ NCDEQ - North Carolina Department of Environmental Quality
■ NPDES - National Pollutant Discharge Elimination System
■ NTU - Nephelometric turbidity units
■ MS4 - Municipal Separate Storm Sewer System
■ SCM - Stormwater Control Measure
■ TMDL - Total Maximum Daily Load
■ TSS - Total Suspended Solids
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TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
■ UCFRBA - Upper Cape Fear River Basin Association
■ USGS - United States Geological Society
■ WIP - Watershed Improvement Plan
■ WLA - waste load allocation
2. Executive Summary
The City of Durham's Stormwater Quality Group in the Department of Public Works and Division of
Stormwater & GIS Services developed this Total Maximum Daily Load (TMDL) Response Plan to address
water quality impairments in Third Fork Creek due to elevated levels of turbidity and total suspended solids
(TSS). The TSS TMDL for Third Fork Creek was issued in 2005 by the North Carolina Department of
Environmental Quality (NCDEQ) and approved by the U.S. Environmental Protection Agency (EPA). A TMDL
sets the allowable pollutant loads for a waterbody so that actions may be taken to reduce point and
nonpoint source pollution in order to meet State water quality standards (USEPA, 1991).
The Third Fork Creek watershed covers an area of 16.6 square miles and is entirely within Durham's
municipal limits. The watershed includes a large portion of the older and highly developed downtown section
of the City. A 3.6-mile segment of Third Fork Creek is listed as impaired by turbidity; however, the pollutant
reductions for this TMDL are expressed as pounds per year of TSS. Turbidity is a measurement to determine
the cloudiness of stream water. Suspended sediment in streams that cause turbidity can be quantified as a
concentration measurement of the total mass of solids per a unit volume of stream water (e.g., mg TSS / L).
Suspended sediment in Third Fork Creek comes from in -stream erosion of channel banks and stream beds,
erosion and transport due to earth -moving activities (e.g., construction site grading), and is present in runoff
discharged to storm sewer systems.
This response plan is the product of several brainstorming and planning meetings in 2018 involving input
from multiple City and County Departments. This response plan outlines the prevention and mitigation
measures that City and County staff will implement to achieve reductions of turbidity and TSS concentrations
in Third Fork Creek. A prevention measure stops releases of pollutants from happening and a mitigation
measure removes pollutants once they have been released. The actions described in this plan focus on ways
to reduce sediment from in -stream sources (e.g., streambank erosion), construction sources (e.g., new
development and re -development), and other sources.
The recommended prioritized actions that address in -stream sources include streambank restoration and
stabilization, stream channel volume protection for new development, and stream walks to identify eroding
and collapsed streambanks. The prioritized actions that target sediment from construction activity include
using flocculants in construction site ditches, increased sediment and erosion control inspections, stop -work
orders for non -compliant small construction sites (<12,000 square feet), and using storm drain protection
materials for street maintenance work. The prioritized actions that address sediment and turbidity from
other sources include conducting a media campaign, increased street sweeping, adding green infrastructure
to complement traditional stormwater control measures (SCMs), prioritizing the construction of SCMs
identified in the Third Fork Creek Watershed Improvement Plan (WIP) that reduce turbidity and sediment,
and steep slope protection on site development projects.
The actions described in this response plan are estimated to be implemented over three permit cycles
(within 15 years). There are five actions estimated to be implemented within the current permit cycle (2018-
2023), there are four actions that may be implemented within 5-10 years (2018-2028), and three actions
estimated to be implemented within 10-15 years (2018-2033). The City's Public Works Department will be
responsible for communicating with the appropriate departments, divisions, and workgroups to identify the
metrics and data needed to track the progress of measures outlined in this response plan. As resources
allow, the City's Public Works Department will re-evaluate the measures outlined in this response plan on a
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TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
five-year basis and will continue to provide progress updates on an annual basis as part of the National
Pollutant Discharge Elimination System (NPDES) Municipal Stormwater Permit annual reporting cycle.
3. TMDL Response Plan Objective
The objective of this TMDL Response Plan is to identify and implement measures that will reduce the levels
of turbidity and TSS in Third Fork Creek within the City limits of Durham, North Carolina. This TMDL Response
plan addresses the City of Durham's assigned municipal separate storm sewer system (MS4) waste load
allocation (WLA) documented in the 2005 EPA -approved TMDL for Third Fork Creek. In addition, this TMDL
Response Plan is required under Section J of the City of Durham's National Pollutant Discharge Elimination
System (NPDES) Municipal Stormwater Permit (No. NCS00249). This response plan incorporates ideas from
multiple stakeholders that have a vested interest in complying with state and federal regulations as well as
reducing the TMDL pollutants of concern and improving overall water quality in the Third Fork Creek
watershed. The proposed prevention and mitigation measures aim to reduce turbidity/TSS levels using a
variety of tools that address the multiple sources and transport pathways of the pollutant of concern. The
variety of tools used in this plan is leveraged by the stakeholder groups' diverse regulatory authority and
capabilities. As a result, the stakeholders included in this response plan have the ability to implement some
but not all of the proposed prevention and mitigation measures. No one entity, including the City of Durham
Public Works Department, has the ability to remedy the turbidity/TSS levels individually, given the nature of
the issue.
4. Introduction and Background
The City of Durham is subject to an approved TMDL with waste load allocations in the Third Fork Creek
watershed, in the Cape Fear River Basin. In 2002, the North Carolina Department of Environmental Quality
(NCDEQ, formerly NCDENR) identified a 3.6-mile segment of Third Fork Creek as impaired by turbidity
(NCDENR, 2003a). Figure 1 shows the impaired segment of Third Fork Creek highlighted in red. A TSS TMDL
for Third Fork Creek was approved in 2005 (Table 1). The pollutant reductions for this TMDL are expressed
as pounds per year of TSS. A maximum TSS load of 0.75 tons per day is required in Third Fork Creek. A WLA
of 0.36 tons TSS per day was assigned to the City of Durham MS4 area and a Load Allocation (LA) of 0.39
tons TSS per day was assigned to nonpoint sources in the Third Fork Creek watershed, which are all located
within the City of Durham. Both point and nonpoint sources were considered and margins of safety were
included in the WLA and LA listed above. The final EPA -approved TMDL document can be found on the North
Carolina Department of Environmental Quality (NCDEQ) website at the link below:
https://files.nc.gov/ncdeq/Water%200uality/Planning/TMDL/FINAL%20TMDLS/Cape%20Fear/Haw%2CDe
ea%2Cetc.TurbidityFecalTM DL.pdf
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TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
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Durham t
Ellerbe
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Jordan f
Third
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Watershed
Chatham Mike
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=County Boundary Impaired Waters. IN
City Limits—(NCDEQ 2016
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Figure 1. Map of the Third Fork Creek Watershed in City of Durham with the impaired segment shown in red.
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TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
Table 1. Approved TMDL for the Third Fork Creek Watershed
Description of area
DWR Assessment
Stream
TMDL Parameter
TMDL
EPA Approval Date
Unit(s)
Classification(s)
Third Fork Creek from
16-41-1-12-(2)
WS-IV NSW.
TSS
0.75 tons per
January 11, 2005
two miles upstream of
Potable water
day of TSS
Highway 54 to New
supply, Nutrient
Hope Creek.
Sensitive Water
NSW. Nutrient Sensitive Water
WS. Water Supply classification
The TSS TMDL for Third Fork Creek was developed because stream monitoring data exceeded the Fresh
Surface Water Quality Standards for Class C Waters under Title 15A, Subchapter 213 of the North Carolina
Administrative Code (NCAC). Under 15A NCAC 02B .0211(21), the water quality standard for turbidity is
stated as follows:
The turbidity in the receiving water shall not exceed 50 Nephelometric Turbidity Units (NTU) in streams
not designated as trout waters and 10 NTU in streams, lakes, or reservoirs designated as trout waters;
for lakes and reservoirs not designated as trout waters, the turbidity shall not exceed 25 NTU; if turbidity
exceeds these levels due to natural background conditions, the existing turbidity level shall not be
increased. Compliance with this turbidity standard can be met when land management activities employ
Best Management Practices (BMPs) has defined by Rule .0202 of this Section] recommended by the
Designated Nonpoint Source Agency [as defined by Rule. 0202 of this Section]. BMPs shall be in full
compliance with all specifications governing the proper design, installation, operation, and maintenance
of such BMPs.
The water quality standard for turbidity is the target that will be used to evaluate the effectiveness of the
measures in this TMDL Response Plan with the overall goal to reduce TSS loads in Third Fork Creek. Annual
updates on progress toward improving turbidity levels and TSS concentrations in Third Fork Creek are
provided in the City of Durham NPDES Municipal Stormwater Permit Annual Report.
Third Fork Creek is also within the B. Everett Jordan Lake watershed. A chlorophyll a TMDL for Jordan Lake
was approved in 2007. The pollutant reductions for this TMDL are expressed as 336,079 pounds per year of
total nitrogen and 23,106 pounds per year of total phosphorus. Target reductions are not expressed
specifically for Third Fork Creek but are expressed as loads to the Upper New Hope Arm of Jordan Lake.
Full implementation of the measures enclosed in this TMDL Response Plan will be enabled as resources
allow. Potential barriers to full implementation include budget constraints, staffing levels, and employee
turnover in departments designated for executing the response plan measures. Some measures presented
in this TMDL Response Plan require significant monetary resources and thus, are highly dependent on the
city budget conditions. The ability to secure support and approval for proposed measures from City Council
and management could potentially influence project schedules. Implementation of this response plan also
depends on coordination and effective partnership with organizations outside of the City of Durham.
4.1. Watershed Information
The Third Fork Creek watershed covers an area of 16.6 square miles and is entirely within Durham's
municipal limits. The watershed includes a large portion of the older and highly developed downtown section
of the City. The creek flows through the heart of many Durham neighborhoods like Tuscaloosa -Lakewood, St.
Teresa, Forest Hills, Hope Valley Farms, and Woodcroft, down to New Hope Creek, which flows into Jordan
Lake. The northern edge or boundary of the watershed lies in downtown Durham, just north of the Durham
Freeway (NC 147), and the southern edge or boundary is close to Interstate 40. The downstream portion of
the watershed contains areas of protected lands, including the game lands associated with Jordan Lake. A
map of the watershed and the impaired section of Third Fork Creek is provided in Figure 1 and a map of
existing land use types in the Third Fork Creek watershed is shown in Figure 2. Land use in the Third Fork
Creek watershed is predominantly a combination of residential development, a dense downtown commercial
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TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
center, and unmanaged open space. Residential land cover is generally higher -density in the northern
portion of the watershed near downtown Durham and lower -density toward the southern mouth of the
watershed. A significant amount of impervious surface associated with transportation networks, downtown
areas, and commercial land uses exists in the north/northeast portion of the watershed. A majority of the
development in the upper and middle portions of the watershed occurred prior to the more robust SCM
controls that are now used with new development. Unmanaged open space and a wildfowl impoundment lie
adjacent to the main stem of Third Fork Creek in the middle and downstream portions of the watershed.
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TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
Headwaters New Ho a Creek 17
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Low -Den- Residential
i} J - Medium -Den Residential
- Off ice
- Vacant Public Lands
- Parks IOpen Space
- Utility
- Vacant
Apartment- Residential
City Limits
Third Fork Creek 0 0-5 1 2 N
Land Use Map mmiles
CITY 0__
oueHnM
Figure 2. 2018 Existing Land Use in the Third Fork Creek watershed
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TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
4.2. Jurisdictional Responsibility
The City of Durham, Durham County, and North Carolina State government have regulatory authority for
controlling the various pathways that sediment can reach Third Fork Creek. These agencies have
responsibilities for implementing different prevention and mitigation measures described in this TMDL
Response Plan.
City of Durham Departments
Within the Public Works Department are the Stormwater & GIS Services Division, the Engineering Services
Division, and the Operations Division. The Stormwater & GIS Services Division is responsible for managing
the following NPDES permit programs: Pollution Prevention & Good Housekeeping, Illicit Discharge Detection
and Elimination, Public Education & Outreach, Public Participation & Involvement, and Post -Construction
Stormwater Management. Stormwater Infrastructure and Watershed Planning are also included in this
division. The Stormwater Development Review Group and the Engineering Services Division are responsible
for reviewing development plans. The Operations Division is responsible for the City's street sweeping
program and maintaining the City's streets and storm drainage system.
Durham County Departments
The Engineering and Environmental Services Department's Stormwater and Erosion Control Division is
responsible for managing the County's stormwater program and inspecting private construction sites.
The Durham Soil and Water Conservation District manages and secures grants for stream restoration
projects and helps protect local water quality by providing consultations and funding for residential
landscape erosion and drainage projects.
Durham City -County Departments
The Planning Department's Zoning Enforcement Division inspects many properties for code violations and
notifies the City Stormwater & GIS Services Division and the County Stormwater and Erosion Control Division
when sediment and erosion control problems or violations are observed during field investigations. The
Unified Development Ordinance (UDO) group is responsible for amending the City -County LIDO and ensuring
compliance with the UDO, which may include measures that prevent or mitigate sources of sediment. The
Planning Department also investigates stream buffer violations and enforces the LIDO stream buffer
requirements in the Cape Fear River Basin.
North Carolina State Government Departments
The Department of Environmental Quality's Division of Water Resources is responsible for investigating
stream buffer violations in the Neuse River Basin and enforcing State regulations when sediment discharges
from construction sites impact downstream surface waters. The Department of Environmental Quality's
Division of Energy, Mineral and Land Resources is responsible for issuing NPDES MS4 permits, which
provide regulatory guidance for developing and implementing TMDL response plans.
5. Pollutant Sources
Suspended sediment is the primary cause of high turbidity levels in Third Fork Creek and has many different
sources throughout the watershed. Both human and natural processes contribute to the amount of sediment
directly discharged to and mobilized within the stream. A large amount of sediment in Third Fork Creek is
generated from and transported in nonpoint source stormwater runoff. This includes runoff from impervious
surfaces (e.g., streets, roofs) and from pervious surfaces through the erosion of soil. Areas where land is
disturbed, like grading or cleared land on construction sites, can also be significant sources of sediment.
Increased impervious cover added throughout a watershed also leads to increased peak flow rates in
streams during storm events and generates higher scouring forces that accelerate stream bank erosion.
Vegetation in stream riparian areas can naturally filter out sediment from overland storm flows and help
11

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
stabilize soil in stream banks and floodplain areas while alterations and removal of riparian vegetation can
contribute to higher sediment and turbidity levels in Third Fork Creek. Discharges of sediment and turbid
substances from municipal facilities, industrial facilities, and construction sites to storm sewer networks and
stream channels directly contribute sediment to Third Fork Creek.
Land
*nl disturbance
Industrial
discharge Erasion
Municipal
discharge Upstrearn
impoundment
Increased sediment
Altered
Land use
I
Increased Channel Riparian area
runoff vol, alteration disturbance
Strearnhank Impaundment
Increased stream erosion management
kinexic energy
Mobilization of bank
delivery to stream & channel sediment
Elevated Levels of
Suspended Sediment
I
Turbidity) Excess
Light Scattering Phytoplankxon- nutrients
I
Fish, insects and aquatic bivalves
,4dapted from SPA 2007 CADblS amceptuo� made
stress or mortality
Figure 3. Sediment generation, fate, and transport conceptual model.
5.1. In -stream Sediment Sources
During storm events, peak flows can lead to elevated sediment transport in stream systems like Third Fork
Creek. These peak flows and fast stream velocities create high shear stress that can mobilize sediment
already in the stream. For example, relatively high shear stresses were associated with high -gradient
meander bends in a Piedmont watershed located in Maryland (Nelson et al., 2006). Stream banks can also
collapse as a part of channel erosion with wider stream channels observed in urban (as opposed to rural)
streams in the southern United States (0'Driscoll et al, 2010). Peak stormwater flows can also cause
channel incision of stream beds with erodible material, like clays and silts, to a greater extent in urban
streams as compared to rural streams (0' Driscoll et al., 2010). These highly erodible soils are present in the
Third Fork Creek watershed.
5.2. Construction/Development Sources of Sediment
In addition to in -stream sources of sediment, upland and floodplain areas can be important factors in
watershed sediment transport. A watershed sediment -budget study conducted in Maryland noted that
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TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
upland erosion can be a significant source of sediment in streams (Allmendinger et al., 2007). Land
disturbance activities including digging, grading, and earth -moving associated with development projects or
repair projects can make upland soils particularly susceptible to erosion. A recent increase in directional
drilling operations associated with the installation of underground fiber optic cables in the City of Durham
has led to more incidents of sediment and turbid water reaching the City's MS4 and streams, including Third
Fork Creek. Riparian areas act as critical barriers that prevent sediment transport to streams - alteration of
these areas during land disturbance activities can enable a significant amount of sediment to reach local
stream channels.
5.3. Runoff from Impervious Surfaces and Direct Discharge
Sediment reaching storm sewer networks through direct discharge or in runoff from impervious surfaces can
contribute to instream turbidity issues and higher TSS loading. Sediment can come from sources including
municipal facilities, soil erosion on residential properties, and sediment associated with commercial
facilities, industrial site facilities, and accumulated material on impervious surfaces like streets and parking
lots. This sediment is washed off of impervious surfaces and can be transported through storm drain
networks to local streams.
6. Pollution Prevention and Mitigation Measures Currently Being Implemented
6.1. Response Plan Measure Definitions
The measures described in this TMDL Response Plan fall into two main categories: Prevention and
Mitigation. The definitions below apply to this plan and may be reviewed and modified in future revisions of
this plan.
A prevention measure is defined as a management practice, procedure, requirement or other action that can
stop a release of pollution from happening. For Third Fork Creek, prevention measures are designed to
target sediment at its source by preventing sediment from reaching the storm drainage system and surface
waters. Prevention measures prioritized in Third Fork Creek include:
■ Conducting media campaigns to motivate the public to take specific actions that reduce sources of
sediment
■ Providing sediment and erosion control materials to City Public Works crews
■ Managing steep slopes for development projects
A mitigation measure is defined as a practice, control measure, technology, requirement, or other action that
can remove pollution once it has been released, reached the storm drainage system, or reached surface
waters. For Third Fork Creek, mitigation measures are designed to contain or remove sediment and
decrease in -stream turbidity. Mitigation measures prioritized in Third Fork Creek include:
■ Implement stream restoration and streambank stabilization projects
■ Increasing the frequency of street sweeping
■ Enable utilization of green infrastructure to complement traditional SCMs in post -construction
stormwater management strategy
■ Install SCMs that address TSS and turbidity in developed areas
■ Utilization of flocculants in drainage ditches on construction sites
In addition to identifying new mitigation and prevention measures, the 2018 brainstorming sessions held by
the Stormwater & GIS Services Division also identified measures that are currently being implemented by
City and County departments and may not have been reported in the previous NPDES annual reports. Table
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TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
2 below shows the list of seven measures that were discussed during the brainstorming sessions and are
currently implemented in the Third Fork Creek watershed. The next step is to communicate with each
responsible department about the best method for collecting and reporting the data in the TMDL Response
Plan updates.
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TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
Table 2. Measures currently implemented in the Third Fork Creek watershed
Measure Current) Implemented
Y p
NPDES Minimum Measure Category
g rY
Estimated Impact on Reducing Sediment
p g
Group(s) Responsible for
Implementation
Jurisdiction
City-wide street sweeping program (including Third Fork Creek).
Pollution Prevention/Good Housekeeping for
High
Public Works Operations
City
Municipal Operations
Conduct monthly inspections on privately -funded construction sites. Promptly issue violations
Construction Site Stormwater Runoff Control
Medium -High
Stormwater & Erosion Control
County
for off -site sediment discharges from active construction sites.
Adherence to field crew protocols for sweeping and shoveling sediment in the street and curb
Pollution Prevention/Good Housekeeping for
Low -Medium
Water Management - Water & Sewer
City
gutter during and after street water line repair work in order to prevent sediment from entering
Municipal Operations
Maintenance
storm drains.
Remove sediment from clogged storm drains prior to flushing storm drains which prevents
Pollution Prevention/Good Housekeeping for
Low -Medium
Public Works Operations
City
more sediment from being released into a nearby stream.
Municipal Operations
Conduct site inspections monthly and conduct lot sweeping 1-2 times per month or as needed
Pollution Prevention/Good Housekeeping for
Low -Medium
Public Works Operations
City
at the Public Works Operation Center (PWOC). Regularly check and replace sediment control
Municipal Operations
bags in stormwater catch basins at PWOC.
Conduct routine inspections and maintenance of stormwater catch basins.
Pollution Prevention/Good Housekeeping for
Low
Public Works Operations, Stormwater &
City
Municipal Operations
GIS - Infrastructure
Disturbed land must be stabilized with ground cover, devices, or structures sufficient to restrain
Construction Site Stormwater Runoff Control
Medium -High
Stormwater & Erosion Control, Planning
County, City -County
erosion as described in the City -County Unified Development Ordinance (Section 12.10.4(B)).
Conduct weekend enforcement patrols in the Third Fork Creek watershed.
Illicit Discharge Detection and Elimination
Low
Public Works - Stormwater Quality -
City
IDDE
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TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
7. Newly Proposed Pollution Prevention and Mitigation Measures
In 2018, the City's Water Quality Group met with workgroups in several City and County departments to
discuss the TMDL Response Plan measures that were specific to their area of responsibility. There were
several factors discussed during these meetings to help decide whether or not a measure could be
implemented in the Third Fork Creek watershed. Some of the factors that were discussed and considered
during the prioritization process include:
■ the estimated impact that the measure would have on reducing the amount of turbid water and
sediment reaching Third Fork Creek and its tributaries;
■ the group(s) that would be responsible for implementing the measure;
■ the barriers to implementing the measure;
■ the implementation steps;
■ the amount of time (in years) it would take to implement the measure;
■ an approximate order -of -magnitude cost estimation;
■ the NPDES minimum measure category assigned to the measure, if any; and
■ whether or not the responsible group thought the measure should be included in the TMDL
Response Plan
The priority measures shown in Table 3 are discussed in this section and in Section 8 (grouped by the six
minimum measures of the NPDES program). A table of all the priority and non -priority measures proposed for
this TMDL Response Plan is found in Appendix A. The non -priority measures will not be implemented as part
of this TMDL Response Plan, but they may be revisited and implemented as part of future revisions to this
TMDL Response Plan. Appendix B lists all of the measures that were not included in the TMDL Response
Plan due to factors such as the estimated high costs (>$500,000) for implementation, multiple barriers that
could hinder implementation, the estimated low impact on reducing sediment, and the responsible group's
willingness to include the measure in the response plan.
A general measure that addresses all sources of sediment pollution is a media campaign to motivate the
public to take specific actions that reduce sources of turbidity and sediment. This media campaign would
include outlets such as the City website, online videos (e.g., YouTube), social media accounts, the Waterways
newsletter, partnering with the Clean Water Education Partnership, and other methods. Staff members from
Public Education and Pollution Prevention will collaborate on a media campaign. Outcome measures for the
media campaign may be quantified using attendance numbers for in -person outreach events; metrics
tracking views, likes, and shares of educational material posted on social media; and possibly surveying
methods to gauge resident awareness of turbidity/TSS issues in Third Fork Creek.
7.1 Measures to Reduce In -stream Sediment Sources
Intense stormwater runoff from impervious surfaces can cause stream banks to erode and collapse which
adds sediment directly to the stream and increases turbidity levels. The measures in this section are
intended to address stream bank sediment sources.
Perform additional streambank stabilization and restoration. The Public Works Watershed Planning
and Stormwater Infrastructure groups have previously completed a stream restoration project along
Third Fork Creek. The proposed measure would expand on previous efforts and implement additional
stream restoration in the Third Fork Creek watershed. The Watershed Improvement Plan (WIP) for
Third Fork Creek was completed in December 2012 and identified several potential locations where
stream restoration projects could be implemented. This measure would likely involve collaboration
16

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
between Public Works and other City departments in addition to non -city groups such as the Durham
County Soil & Water Conservation District.
Routine stream -walk program for Third Fork Creek; target main stem and tributaries with historically
higher incidences of illicit discharges of sediment and also inspect and assess stream bank erosion.
The City will establish a schedule and procedures for surveying sections of Third Fork Creek and its
tributaries to identify turbid discharges and illicit discharges of sediment from the City's storm drain
system. Stream -walk teams will inspect major outfalls that discharge to Third Fork Creek and its
tributaries. The City's Stormwater Quality Group will perform the routine stream walks and
communicate with County Stormwater and Erosion Control for issues related to construction site
stormwater runoff control. The Stormwater Quality Group will also require responsible parties to
clean up sediment discharges through enforcement of the Stormwater Management and Pollution
Control Ordinance. Stream walk teams will also inspect stream banks for areas of active and
potential erosion or bank instability. The location of problematic areas with high erosion potential will
be shared with the Public Works Watershed Planning group to examine the feasibility of including
these areas in future stream stabilization and restoration projects.
Investigate highly effective channel protection methods to reduce streambank scour including
stream channel protection volume (CPV) measures. If supporting evidence (e.g., data, technical
reports, etc.) and justification to develop a channel protection requirement exists, the Public Works
Stormwater Development Review group would propose modifications to design criteria for SCMs and
submit proposed City code changes for public comment. The City would also ensure that the
proposed design criteria and regulations comply with any State laws related to stormwater control
measures for new development and redevelopment. Implementation of this measure would require
public support and approval by Durham City Council.
7.2 Measures to Reduce Construction Sources of Sediment
Promote the use of flocculants in drainage ditches on construction sites to settle out sediment and
solids. The County Stormwater and Erosion Control Division would be responsible for researching the
practice and developing design criteria for effective use in the field. This division would also pursue
formal policy adoption and approval (e.g., Unified Development Ordinance changes). The Public
Works Stormwater Quality group would create a one -page handout about flocculant guidance or
update current construction handouts to include guidance on the use of flocculants. This educational
material can be distributed to the contractors to keep the construction community up-to-date and
informed on how to implement the use of flocculants as part of sediment and erosion control
practices.
Conduct more frequent sediment & erosion inspections and enforcement. The Durham County
Stormwater and Erosion Control Division will aim to increase the annual number of sediment and
erosion control inspections performed on active construction sites within Durham County. To date,
the number of inspections has been limited by the number of sediment and erosion control
inspectors that are on staff. The Stormwater and Erosion Control Division will increase the number of
inspectors. Challenges to successfully implementing this measure include identifying qualified
candidates and securing funding for additional positions.
Change City code to grant authority for the City's Public Works Department to issue a "stop -work
order" for small construction sites that are not in compliance with required sediment and erosion
control practices. County sediment and erosion control inspectors do not have the authority to
inspect small construction sites (<12,000 sf). The Public Works Stormwater Quality group will aim to
gain authority to issue a "stop -work order" for small construction sites that are discharging sediment
to the City's storm drain system. This effort will include developing and proposing text for
modification of the ordinance, gaining approval for the change, and training staff and developing a
workflow for the stop -work orders.
17

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
7.3 Measures to Reduce Other Sources of Sediment
Conduct a media campaign to motivate the public to take specific actions that reduce sources of
sediment and turbidity through the City's website, online videos (e.g. YouTube), social media
accounts, Waterways newsletter, Clean Water Education Partnership (CWEP) handouts, and other
methods. A media campaign will be undertaken to encourage the public to take specific actions
which may reduce sediment runoff in Third Fork Creek. For example, planting a vegetated buffer,
stabilizing a gravel driveway, or growing a healthy lawn can reduce sediment and erosion issues on
private property. The Public Works' Stormwater Quality and Watershed Planning groups will leverage
previous public education and outreach efforts to inform residents about sources, pollution
prevention techniques, transport pathways, and impacts of sediment on local streams.
■ Implement an Adopt -a -Drain program that encourages residents to participate in removing
sediment, leaves, and trash from the street gutter near and around storm drain grates. An
interactive web map and registration website have been developed for this program. Public
education staff in the Public Works' Watershed Planning Group will be responsible for managing the
Adopt -a -Drain program when it is handed over to the City in 2019.
Increase street sweeping frequency in the Third Fork Creek watershed. The Public Works Operations
Division will aim to increase the annual number of streets swept in Third Fork Creek. To date, the
amount of street sweeping has been limited by the staffing numbers in the division. The Operations
Division will aim to increase the number of street maintenance staff members. Challenges to
successfully implementing this measure include identifying qualified candidates and retaining staff
members.
Purchase, supply, and educate Public Works Operations Division field staff with the materials they
need to protect storm drains during street maintenance work. The Public Works Department will
purchase supplies for street maintenance crews to protect storm drains during street maintenance
operations. The pollution prevention supplies will be distributed to and utilized within the Public
Works Operations Division. The Stormwater Quality group's pollution prevention staff will assist in
providing training to street maintenance crews.
Review the Third Fork Creek Watershed Improvement Plan (WIP) and implement the construction of
SCMs identified in the WIP that address TSS. The City's Watershed Planning Group and Stormwater
Quality Group will be responsible for reviewing the WIP and prioritizing SCMs that will be built,
assuming available land, funding, and public support. The Watershed Planning Group will be
responsible for coordinating public communication, land acquisition, and contract management for
the construction of the SCMs.
Explore strategies to promote greater use of green infrastructure to complement traditional SCMs &
BMPs in the City's post -construction stormwater management efforts. This includes determining
effective incentives to encourage green infrastructure utilization on private site development.
Investigate using green infrastructure on City projects. Research and recommend effective City code
changes to reduce barriers to implementing green infrastructure in public and private development
projects.
(A) For development and planning, designate slopes as Preserved (natural areas >25 % slope) and
Man-made (managed areas >25%). (B) Eliminate 50% slope (2:1) allowance. Add steep slope
violation, encroachment clarification in the Unified Development Ordinance. The City -County
Planning Department will investigate the development of slope protection regulations for natural
areas and managed areas, eliminate 50% slope (2:1) allowance, and clarify steep slope
encroachment violation language in the ordinance. This will include modification of existing slope
protection rules and/or development of new rules. The Planning Department will lead the
modification of the Unified Development Ordinance and the approval process through the City
:

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
Council. The Public Works' Stormwater Development Review Group and Engineering Services
Division will assist in the ordinance change.
19

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
Table 3. Prioritized Measures in the Third Fork Creek watershed
Proposed Measure
Type of
NPDES Minimum Measure
Estimated Impact on Reducing
Group(s) Responsible for Measure
Estimated Cost
Implementation
Measure
Turbidity/TSS
Implementation
to Implement
Timeline (years)
Measure
Perform additional streambank stabilization and restoration.
Mitigation
NA
High
Public Works - Watershed Planning; Public
$$$
10-15
Works - Infrastructure; County Soil & Water
Conservation District
Increase street sweeping frequency in the Third Fork Creek watershed.
Mitigation
Pollution Prevention/Good
High
Public Works - Operations
$$$
5-15
Housekeeping for Municipal Operations
More frequent sediment & erosion inspections and enforcement.
Mitigation
Construction Site Stormwater Runoff
High
County Stormwater & Erosion Control
5-15
Control
Promote the use of flocculants in drainage ditches on construction
Mitigation
Construction Site Stormwater Runoff
High
Public Works - Stormwater & GIS - IDDE;
$
0-5
sites to settle out sediment and solids. Create a one -page handout
Control
County Stormwater and Erosion Control
about flocculant guidance or update current construction handout to
include guidance on the use of flocculants.
Review Third Fork Watershed Improvement Plan (WIP) and implement
Mitigation
NA
Medium -High
Public Works - -Watershed Planning and
$$$
5-10
the construction of SCMs identified in the WIP that address TSS.
Stormwater Quality
Routine stream -walk program to target the main stem and tributaries
Mitigation
Illicit Discharge Detection and
Medium
Public Works - Stormwater Quality
0-5
with historically higher incidences of illicit discharges. Also, inspect
Elimination
and assess stream bank erosion.
Investigate highly effective channel protection methods to reduce
Mitigation
Post -Construction Stormwater
Medium
Public Works - Stormwater Development
$
0-5
streambank scour including stream channel protection volume (CPV)
Management
Review
measures.
Explore strategies to promote greater use of green infrastructure to
Mitigation
Post -Construction Stormwater
Low -Medium
Public Works - Stormwater Development
5-10
complement traditional SCMs & BMPs in the City's post -construction
Management
Review
stormwater management efforts.
Change City code to grant authority for the City's Public Works
Mitigation
Construction Site Stormwater Runoff
Low -Medium
Public Works - Stormwater Quality; City
$
5-10
Department to issue a "stop -work order" for small construction sites
Control
Attorney; City Manager; City Council
that are not in compliance with required sediment and erosion control
practices.
Purchase and supply Public Works Operations Division field staff with
Prevention
Pollution Prevention/Good
Low -Medium
Public Works - Operations
$
0-5
the materials they need to protect storm drains during maintenance
Housekeeping for Municipal Operations
work in the street.
Conduct a media campaign to motivate the public to take specific
Prevention
Public Education and Outreach
Low -Medium
Public Works - Stormwater Quality and
$
0-5
actions that reduce sources of sediment and turbidity through the
Watershed Planning; CWEP Contractor
City's website, online videos (e.g. YouTube), social media accounts,
Waterways newsletter, CWEP handouts, and other methods.
(A) For development and planning, designate slopes as Preserved
Prevention
Construction Site Stormwater Runoff
Low -Medium [(A) - Low, (B) - Med)]
Public Works -Stormwater Development
$ - $$
5-10
(natural areas >25% slope) and Man-made (managed areas >25%).
Control
Review and Engineering Services; City-
(B) Eliminate 50% slope (2:1) allowance. Steep slope violation,
County Planning;
encroachment clarification in the Unified Development Ordinance.
Implement an Adopt -a -Drain program that encourages residents to
Prevention
Public Participation and Involvement
Low
Public Works - Watershed Planning
$
0-5
participate in removing sediment, leaves, and trash from the street
gutter near and around storm drain grates.
Estimated Costs: $$$ > $500,000, = $50,000 to $500,000, $ <$50,000. Estimated costs consider only the projected costs to the City and County departments.
20

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
8. Prioritized Measures Applicable to the NPDES Six Minimum Measures
This section highlights the prioritized response plan measures that fall under the six minimum control
measures for the EPA's Stormwater Phase II Final Rule. The prioritized measures in this response plan
address Public Education and Outreach, Public Participation and Involvement, IDDE, Construction Site
Stormwater Runoff Control, and Post -Construction Stormwater Management, Pollution Prevention and Good
Housekeeping
8.1. Implementation of Plan to the Maximum Extent Practicable
The City will implement response plan measures to the maximum extent practicable (MEP) with the goal of
reducing the levels of turbidity and TSS in Third Fork Creek. While the elimination of all turbidity and TSS
point and nonpoint sources may reduce concentrations below water quality standards, it is recognized that
this may not be feasible due to technical, economic, logistic or social factors. Therefore, the City will pursue
turbidity and TSS reductions to the MEP based on Clean Water Act and MS4 NPDES requirements. Section
402(p)(3)(B) of the Clean Water Act requires municipal MS4 permittees, to the extent allowable under State
or local law, to prohibit non-stormwater discharges into the MS4 and implement controls and management
measures to reduce the discharge of pollutants to the maximum extent practicable. Section J(1)(b) of the
City's MS4 NPDES permit also requires that the City utilize BMPs (commonly referred to as SCMs) pertaining
to the six minimum measures and the TMDL Response Plan to meet the approved TMDL WLA to the MEP.
Additionally, Section J(1)(c) of the City's MS4 NPDES also states that the City is not responsible for attaining
State water quality standards as this requires pollutant reductions from all point and nonpoint sources
identified in the approved TMDL.
8.2. Public Education and Outreach
City of Durham, Public Works Department, Stormwater & GIS Services Division
Measure
Timeline
■ Conduct a media campaign to motivate the public to take 0 to 5 years
specific actions that reduce sources of sediment and turbidity
through the City's website, online videos (e.g. YouTube), social
media accounts, Waterways newsletter, CWEP handouts, and
other methods.
8.3. Public Participation and Involvement
City of Durham, Public Works Department, Stormwater & GIS Services Division
Measure
Timeline
Implement an Adopt -a -Drain program that encourages 0 to 5 years
residents to participate in removing sediment, leaves, and
trash from the street gutter near and around storm drain
grates.
21

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
8.4. Illicit Discharge Detection and Elimination
City of Durham, Public Works Department, Stormwater & GIS Services Division
Measure Timeline
■ Routine stream -walk program to target main stem and 0 to 5 years
tributaries with historically higher incidences of illicit discharges
of sediment. Also inspect major outfalls (greater than 36"
diameter pipe) for turbid discharges and assess stream bank
erosion.
8.5. Construction Site Stormwater Runoff Control
City of Durham, Public Works Department, Stormwater & GIS Services Division
Measure
■ Promote the use flocculants in drainage ditches on
construction sites to settle out sediment and solids. Create a
one -page handout about flocculant guidance or update current
construction handout to include guidance on the use of
flocculants.
■ Change City code to grant the Public Works Department
authority to issue a "stop work order" for small construction
sites that are not in compliance with required sediment and
erosion control practices.
Timeline
0 to 5 years
5 to 10 years
Durham County, Engineering and Environmental Services Department, Stormwater and
Erosion Control Division
Measure Timeline
■ Conduct more frequent sediment & erosion inspections and 5 to 15 years
enforcement.
22

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
8.6. Post -Construction Stormwater Management
of Durham, Public Works Department, Stormwater & GIS Services Division
Measure Timeline
■ Investigate highly effective channel protection methods to 0 to 5 years
reduce streambank scour including stream channel protection
volume (CPV) measures.
■ Explore strategies to promote greater use of green 5 to 10 years
infrastructure to complement traditional SCMs & BMPs in the
City's post -construction stormwater management efforts.
8.7. Pollution Prevention/Good Housekeeping for Municipal Operations
City of Durham, Public Works Department, Operations Division
Measure
■ Purchase and supply Public Works Operations Division field
staff with the materials they need to protect storm drains
during maintenance work in the street.
Increase street sweeping frequency in the Third Fork Creek
watershed.
9. Watershed Planning
Timeline
0 to 5 years
5 to 15 years
Watershed planning is an additional measure that the City of Durham has incorporated into the Stormwater
program. Although this is not one of the Phase II minimum measures, this program does provide information
and direction regarding practices in the Third Fork Creek watershed.
In 2007 the City began the process of developing Watershed Improvement Plans for watersheds across the
City. As of December 2018, watershed improvement plans have been completed for Ellerbe Creek,
Northeast Creek, Crooked Creek, Third Fork Creek, Little Lick Creek, and Eno River. Each plan identifies new
opportunities for stormwater control measures, as well as opportunities to upgrade existing measures (i.e.,
retrofit existing measures). Extensive field work is conducted in the watershed planning process to verify on -
the -ground conditions prior to carrying a project concept forward. Stream restorations are also evaluated as
potential control measures to pollution that can arise from the stream bank (e.g., sediment/turbidity). Each
plan provides a recommended list of ranked new stormwater control measures, opportunities for retrofitting
measures, and stream restoration. Cost estimates are provided for each measure or restoration opportunity.
The City finalized the Third Fork Creek Watershed Improvement Plan in December 2012. The Watershed
Improvement Plan notes that approximately 23 percent of the Third Fork Creek watershed lies within the
23

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
watershed protection overlay district. New development has been required to design stormwater controls to
remove 85 percent of total suspended solids within the watershed overlay district since 1985, and
everywhere in Third Fork Creek since 2009 when Phase II post -construction requirements took effect. The
Third Fork Creek Watershed Improvement Plan found that 35% of the channels within Third Fork Creek were
rated as Fair and 19% were rated as poor for channel stability. The completed plan recommended stream
corridor restoration for six stream reaches, or 5,475 feet of stream. Stream corridor restoration would have
a high impact on sediment levels in Third Fork Creek and these reaches have been identified as unstable or
degraded to the point where they are significantly contributing to water quality problems as discussed in
section 2.4.6 of the Stormwater Management Plan.
A computer -based watershed water quality model known as the Storm Water Management Model (SWMM)
was set up to simulate the Third Fork Creek watershed and help develop the WIP. The model simulated the
capability of existing SCMs in the watershed to manage runoff volume and pollutant washoff (including
sediment). The model helped identify areas with the highest amounts of pollutants of concern and prioritize
areas in need of new or improved stormwater treatment. There were numerous recommendations for new
SCMs or SCM retrofits that included constructed wetlands, bioretention areas, and wet detention ponds.
Each of these types of structural SCMs also remove sediment, including the smallest particles that cause
turbidity. Structural SCMs also provide peak flow detention of stormwater runoff from impervious surfaces
and helps reduce the presence of erosive high -flow conditions in stream channels. A total of 15 new high -
priority structural SCMs were recommended in the Third Fork Creek WIP.
10. Water Quality Assessment and Monitoring
10.1. Water Quality Monitoring
The City of Durham has a routine ambient stream monitoring program to generate data that describe the
condition of streams in the City and County limits. The City's Stormwater Management Plan states that the
ambient stream monitoring program supports the following assessment goals (City of Durham, 2017):
■ to identify pollution problem areas within the City of Durham;
■ to assess compliance with state water quality programs, including TMDLs and nutrient management
strategies;
■ to determine pollution removal credits;
■ to identify overall water quality trends; and
■ to evaluate the water quality impacts of urban stormwater on area streams
The monitoring program includes water chemistry, biological monitoring (benthic macroinvertebrates and
habitat assessment), and hydrologic monitoring. The ambient water chemistry program focuses on surface
water conditions. Special studies are conducted on an infrequent basis to assess stream sediment
chemistry. City monitoring staff follow procedures outlined in the Ambient Water Chemistry Monitoring
Program Quality Assurance Project Plan and collect grab samples monthly at scheduled monitoring sites.
Samples are collected at all monitoring sites in a given basin on the same day. The City uses a rotating
stream basin approach to monitor sites in each basin every two years; however, monitoring sites are
evaluated at the end of each year and site locations are adjusted to meet the City's water quality
assessment needs. The TMDL for Third Fork Creek was developed because turbidity violations were the
reason for listing the creek on the state 303(d) list; however, the TMDL is expressed in terms of TSS loading.
The TMDL assumes that in meeting the TSS target load that the turbidity violations will decrease to an
acceptable level. The City of Durham tracks both turbidity and TSS loads in Third Fork Creek in order to
evaluate compliance with both the TMDL and the water quality standard for turbidity.
24

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
The Third Fork Creek ambient stream monitoring sites for the City, Upper Cape Fear River Basin (UCFRBA),
and State Division of Water Resources (DWR) are shown below in Figure 4. The City of Durham has seven
water quality monitoring stations in Third Fork Creek - five stations are monitored on even years and two
locations are monitored consistently that are near continuous stream monitoring gaging stations. These two
locations (TF3.4.TC and TFLOTC) are near the Public Works Operation Center at MLK Jr. Pkwy and further
downstream at Woodcroft Pkwy. Downstream of these City of Durham monitoring stations is the UCFRBA
monitoring station at Highway 54 (133025000) and continuous discharge data collection by the US
Geological Survey. This location is the TMDL compliance point. The acceptable criterion at the compliance
point is no more than 10% of the turbidity data in a five-year period exceeding the water quality standard of
50 NTU. Evaluating turbidity on an annual basis since 2010, turbidity levels have exceeded the water quality
standard in more than 10% of samples during three years. In September 2018, a completed stream
restoration project stabilized 1,250 linear feet of Third Fork Creek and replaced 700 linear feet of an asphalt
walking trail with a new boardwalk. This may affect turbidity concentrations as well as annual loads.
25

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
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Figure 4. City of Durham, UCFRBA, and DWR ambient stream monitoring sites in the Third Fork Creek
watershed.
26

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
10.2. Turbidity Data and Computed TSS Loads
Loads of TSS are typically calculated annually using the USGS load estimation program LOADEST (Mod4.8,
March 2013). For each NPDES Permit Annual Report Update, loads are recalculated each year. A minimum
of 5 years of data are used to calibrate LOADEST for TSS load calculations. As a result, all load estimations in
this report will differ from previous reports, in some years significantly.
Estimates of the mean monthly load are provided by LOADEST, including the upper and lower 95%
confidence limits on the mean monthly load. These were used to estimate the mean annual load and the
95% confidence limits on that load. These load estimates were compared to the TMDL load of 547,500
pounds/year.
11. Water Quality Co -Benefits of TMDL Response Plan Implementation
Implementation of the priority measures for the Third Fork Creek TMDL Response Plan aims to reduce
turbidity and TSS loading to the creek and will also have co -benefits in reducing other pollutants and
improving the aquatic habitat. For example, reduction of sediment in Third Fork Creek could reduce other
pollutants like metals and nutrients. Reductions of these pollutants, possible increases in dissolved oxygen
concentrations, and improved aquatic habitat quality could lead to healthier populations of benthic
macroinvertebrates and fish.
11.1. Value Added to Removal of Nutrients and Metals
A co -benefit of implementing priority measures with this TMDL Response Plan is decreased transport of
nutrients and other pollutants. Instream concentrations of heavy metals like copper, zinc, and lead have
been correlated with higher suspended sediments and are transported during storm events (Balogh et al.,
1997; Cravotta and Bilger,2001). Reduced TSS loading achieved through the implementation of priority
measures could result in lower concentrations of copper, which is a pollutant that Third Fork Creek is listed
for on the Final 2016 NCDEQ 303d list (NCDEQ, 2016; Table 4). Suspended sediment can also serve as a
transport medium for nutrient pollutants like nitrogen and phosphorus (House et al., 1998). Reductions in
nutrient loading achieved could positively impact water quality in Jordan Lake, which, is currently impacted
by excess nutrients. Suspended sediment is comprised of a mixture of flocculated inorganic particles (e.g.,
clays and silts), bacterial and algal communities, and organic particles (Droppo, 2001) - decreasing
suspended sediment loading could lead to decreased bacteria transport (Badgley et al., 2011). Decreased
turbidity and TSS would increase water clarity and light penetration into the water column, fostering the
growth of plants and algae at the primary trophic level (Henley et al., 2000). This could increase dissolved
oxygen generation through photosynthetic activity, helping address the 2016 Final 303(d) listing of Third
Fork Creek for dissolved oxygen.
Table 4. NCDEQ 2016 Final 303(d) List (NCDEQ 2016), Category 5 Assessments for Third Fork Creek.
Impaired
Description of
Assessment
segment
Assessment
Reason for Rating
Parameter of
I Category
stream segment
Unit(s)
length
Criteria Status
Interest
(miles)
From source to a
16-41-1-12-
5.16
Exceeding
> 10% and >90% conf
Zinc (50 pg/L;)
5
point 2.0 miles
(1)
Criteria
> 10% and <90% conf
Copper (7 ug/L)
5e
upstream of NC
> 10% and >90% conf
Dissolved Oxygen (4
5
Hwy. 54
mg/L)
From a point 2.0
16-41-1-12-
3.86
Exceeding
> 10% and >90% conf
Dissolved Oxygen (4
5
miles upstream of
(2)
Criteria
mg/L;)
NC HWY. 54 to New
> 10% and <90% conf
Copper (7 ug/L)
5e
Hope Creek
27

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
11.2. Benefits to Aquatic Life
Reducing turbidity and TSS could potentially foster significant improvements in fish, benthic
macroinvertebrates, and aquatic life in Third Fork Creek. Fine fractions of suspended sediment are known to
result in declines in benthic macroinvertebrates and fish presence and diversity (Henley et al., 2000; Bilotta
and Brazier, 2008) - implementation of priority measures for this TMDL Response Plan could potentially
result in increased health in populations of these aquatic insects. The growth of plants and algae at the
primary trophic level, discussed above, could create a healthier habit for benthic macroinvertebrates and
fish to thrive. Decreased suspended sediment concentrations have been shown to decrease microbial
production of ammonia, which is toxic to fish (Xia et al., 2009).
12. Steps Towards TMDL Response Plan Implementation
The Third Fork Creek TMDL Response Plan will be implemented by workgroups in Durham City and County
government. This implementation process is not necessarily a direct prescriptive process - depending on
the level of change that implemented response measures are having on turbidity and TSS loads in Third Fork
Creek. Adapting and modifying the response plan will be informed through ongoing analysis of programmatic
data collected to quantify progress.
12.1. Response Plan Schedule by Agency
This section organizes the prioritized response plan measures by the departments that are responsible to
implement them. The prioritized measures in this response plan will be implemented in partnership between
City of Durham Public Works Department (Stormwater and GIS Services Division, Operations Division) and
Durham County, Engineering and Environmental Services Department, Stormwater and Erosion Control
Division. The timeline for implementation of the prioritized response plan measures is between five and
fifteen years.

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
City of Durham, Public Works Department, Stormwater & GIS Services Division
Measure Timeline
■ Conduct a media campaign to motivate the public to take 0 to 5 years
specific actions that reduce sources of sediment and turbidity
through the City's website, online videos (e.g. YouTube), social
media accounts, Waterways newsletter, CWEP handouts, and
other methods.
■ Implement an Adopt -a -Drain program that encourages 0 to 5 years
residents to participate in removing sediment, leaves, and
trash from the street gutter near and around storm drain
grates.
■ Routine stream -walk program to target main stem and 0 to 5 years
tributaries with historically higher incidences of illicit
discharges. Also inspect and assess stream bank erosion.
■ Promote the use of flocculants in drainage ditches on 0 to 5 years
construction sites to settle out sediment and solids. Create a (in coordination with
one -page handout about flocculant guidance or update current County Stormwater &
construction handout to include guidance on the use of Erosion Control Div.)
flocculants.
■ Investigate highly effective channel protection methods to 0 to 5 years
reduce streambank scour including stream channel protection
volume (CPV) measures.
■ Explore strategies to promote greater use of green 5 to 10 years
infrastructure to complement traditional SCMs & BMPs in the
City's post -construction stormwater management efforts.
■ Review Third Fork Watershed Improvement Plan (WIP) and 5 to 10 years
implement the construction of SCMs identified in the WIP that
address TSS.
■ Change City code to grant authority for the City's Public Works 5 to 10 years
Department to issue a "stop work order" for small construction (in coordination with City
sites that are not in compliance with required sediment and Management and Council)
erosion control practices.
■ (A) For development and planning, designate slopes as 5 to 10 years
Preserved (natural areas >25% slope) and Man-made (in coordination with Eng.
(managed areas >25%). (B) Eliminate 50% slope (2:1) Services Div. and City -
allowance. Steep slope violation, encroachment clarification in County Planning Dept.)
ordinance.
■ Perform additional streambank stabilization and restoration. 10 to 15 years
29

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
City of Durham, Public Works Department, Operations Division
Measure
Purchase and supply Public Works Operations Division field
staff with the materials they need to protect storm drains
during maintenance work in the street.
■ Increase street sweeping frequency in the Third Fork Creek
watershed.
Timeline
0 to 5 years
5 to 15 years
Durham County, Engineering and Environmental Services Department, Stormwater and
Erosion Control Division
Measure Timeline
■ Conduct more frequent sediment & erosion inspections and 5 to 15 years
enforcement.
12.2. Tracking and Data Collection
The City's Public Works Department will communicate with the appropriate departments, divisions, and
workgroups to identify the metrics and data needed to track the progress of measures outlined in this
Response Plan. A preliminary list of metrics that may be used to track incremental progress for this
Response Plan is shown in Appendix C.
12.3. Re-evaluation of Response Plan
The City's Public Works Department will re-evaluate the measures outlined in this TMDL Response Plan on a
five-year basis, as resources allow. Modifications to the response plan will depend on reductions in turbidity
and TSS concentrations, the feasibility of implementing measures, stakeholder needs, and new measures
identified. The City will continue to provide progress updates on an annual basis as part of the NPDES
Municipal Stormwater Permit annual reporting cycle.
13. References
Allmendinger, N.E., Pizzuto, J. E., Moglen, G. E., and Lewicki, M. 2007. A sediment budget for an urbanizing
watershed 1951-1996, Montgomery County, Maryland, U.S.A. Journal of the American Water Resources
Association, 43(6), 1483-1498.
Badgley, B. D., Thomas, F. I. M. and Harwood, V. J. 2011. Quantifying environmental reservoirs of fecal
indicator bacteria associated with sediment and submerged aquatic vegetation. Environmental Microbiology
13(4), 932-942.
30

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
Bilotta, G. S. and Brazier, R. E. 2008. Understanding the influence of suspended solids on water quality and
aquatic biota. Water Research 42(12), 2849-2861.
City of Durham. 2017. City of Durham Stormwater Management Program Plan. Public Works Department.
August, 2017. Durham, NC.
Droppo, I. G. 2001. Rethinking what constitutes suspended sediment. Hydrological Processes 15(9), 1551-
1564.
Henley, W. F., Patterson, M. A., Neves, R. J. and Lemly, A. D. 2000. Effects of sedimentation and turbidity on
lotic food webs: A concise review for natural resource managers. Reviews in Fisheries Science 8(2), 125-
139.
House, W. A., Jickells, T. D., Edwards, A. C., Praska, K. E. and Denison, F. H. 1998. Reactions of phosphorus
with sediments in fresh and marine waters. Soil Use and Management 14, 139-146.
Nelson, P.A., Smith, J.A., and Miller, A.J. 2006. Evolution of channel morphology and hydrologic response in
an urbanizing drainage basin. Earth Surf. Process. Landf. 31, 1063-1079.
North Carolina Department of Environment and Natural Resources (NCDENR). 2003. North Carolina Water
Quality Assessment and Impaired Waters List (2002 Integrated 305(b) and 303(d) Report). February, 2003.
Raleigh, NC.
North Carolina Department of Environment and Natural Resources (NCDENR). 2005. Total Maximum Daily
Load for Turbidity and Fecal Coliform for Haw River, Deep River, Third Fork Creek, and Dan River in North
Carolina. January, 2005. Raleigh, NC.
North Carolina Department of Environmental Quality (NCDEQ). 2016. 2016 Integrated Report - All Assessed
Waters, 2016 Final 303(d) List. April, 2018. Raleigh, NC.
0' Driscoll, M., Clinton, S., Jefferson, A., Manda, A., and McMillan, S. 2010. Urbanization Effects on
Watershed Hydrology and In -Stream Processes in the Southern United States. Water 2, pg. 605-648.
Tetra Tech. 2012. Durham Third Fork Creek Watershed Management Plan. Prepared for the City of Durham.
December, 2002. Durham, NC.
U.S. Environmental Protection Agency (USEPA). 1991. Guidance for Water Quality -based Decisions: The
TMDL Process. Assessment and Watershed Protection Division. April, 1991. Washington, DC.
Waite, T.D. 1984. Principles of Water Quality. Academic Press, New York.
Xia, X., Yang, Z. and Zhang, X. 2009. Effect of suspended -sediment concentration on nitrification in river
water: Importance of suspended sediment -water interface. Environmental Science and Technology 43(10),
3681-3687.
31

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
14. Appendix A: Summary Table of All Proposed Measures (Priority and Non -Priority)
Table 5 Priority and non -priority measures proposed for the Third Fork Creek TMDL Response Plan
Proposed Measure
Type of
NPDES Minimum Measure
Estimated Impact
Group(s) Responsible for Measure
Estimated
Implementation
Priority
Measure
on Reducing
Implementation
Cost to
Timeline
Turbidity/TSS
Implement
(years)
Measure
Perform additional streambank stabilization and restoration.
Mitigation
NA
High
Public Works -Watershed Planning;
$$$
10-15
Yes
Public Works - Infrastructure; Soil &
Water Conservation District
Increase street sweeping frequency in the City.
Mitigation
Pollution Prevention/Good Housekeeping
High
Public Works - Operations
- $$$
5-15
Yes
for Municipal Operations
More frequent sediment & erosion inspections and enforcement.
Mitigation
Construction Site Stormwater Runoff Control
High
County Stormwater and Erosion Control
5-15
Yes
Promote the use of flocculants in drainage ditches on construction
Mitigation
Construction Site Stormwater Runoff Control
High
Public Works - Stormwater Quality;
$
0-5
Yes
sites to settle out sediment and solids. Create a one -page handout
County Stormwater and Erosion Control
about flocculant guidance or update current construction handout to
include guidance on the use of flocculants.
Review Third Fork Watershed Improvement Plan (WIP) and implement
Mitigation
NA
Medium -High
Public Works - Watershed Planning and
$$$
5-10
Yes
the construction of SCMs identified in the WI that address TSS.
Stormwater Quality
Routine stream -walk program to target the main stem and tributaries
Mitigation
Illicit Discharge Detection and Elimination
Medium
Public Works - Stormwater -Quality
$$
0-5
Yes
with historically higher incidences of illicit discharges. Also, inspect
and assess stream bank erosion.
Investigate highly effective channel protection methods to reduce
Mitigation
Post -Construction Stormwater Management
Medium
Public Works - Stormwater Development
$
0-5
Yes
streambank scour including stream channel protection volume (CPV)
Review
measures.
Explore strategies to promote greater use of green infrastructure to
Mitigation
Post -Construction Stormwater Management
Low -Medium
Public Works - Stormwater Development
$$ - $$$
5-10
Yes
complement traditional SCMs & BMPs in the City's post -construction
Review
stormwater management efforts.
Change City code to grant authority for the City's Public Works
Mitigation
Construction Site Stormwater Runoff Control
Low -Medium
Public Works - Stormwater Quality; City
$
5-10
Yes
Department to issue a "stop -work order" for small construction sites
Attorney; City Manager; City Council
that are not in compliance with required sediment and erosion control
practices.
Purchase and supply Public Works Operations Division field staff with
Prevention
Pollution Prevention/Good Housekeeping
Low -Medium
Public Works - Operations
$
0-5
Yes
the materials they need to protect storm drains during maintenance
for Municipal Operations
work in the street.
Conduct a media campaign to motivate the public to take specific
Prevention
Public Education and Outreach
Low -Medium
Public Works - Watershed Planning and
$
0-5
Yes
actions that reduce sources of sediment and turbidity through the
Stormwater Quality; CWEP Contractor
City's website, online videos (e.g. YouTube), social media accounts,
Waterways newsletter, CWEP handouts, and other methods.
32

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
Table 5 Priority and non -priority measures proposed for the Third Fork Creek TMDL Response Plan
Proposed Measure
Type of
NPDES Minimum Measure
Estimated Impact
Group(s) Responsible for Measure
Estimated
Implementation
Priority
Measure
on Reducing
Implementation
Cost to
Timeline
Turbidity/TSS
Implement
(years)
Measure
(A) For development and planning, designate slopes as Preserved
Prevention
Construction Site Stormwater Runoff Control
Low -Medium [(A) -
Public Works -Stormwater Development
5-10
Yes
(natural areas >25% slope) and Man-made (managed areas >25%).
Low, (B) - Med)]
Review and Engineering Services; City-
(B) Remove 50% slope (2:1) allowance and add steep slope violation,
County Planning;
encroachment clarification in the Unified Development Ordinance.
Implement an Adopt -a -Drain program that encourages residents to
Prevention
Public Participation and Involvement
Low
Public Works - Watershed Planning
0-5
Yes
participate in removing sediment, leaves, and trash from the street
gutter near and around storm drain grates.
Promote stream buffer education for residents that disturb land or
Prevention
Public Education and Outreach
Low -Medium
City -County Planning, Public Works-
$
0-5
No
perform construction work on their property.
Watershed Planning, County Stormwater
and Erosion Control, Soil & Water
Conservation District, City- County
Inspections
(A) Provide incentives to attend public education events for invasive
Prevention
Public Education and Outreach
Low
Public Works - Watershed Planning and
$
0-5
No
species education, such as partnering with local nurseries to give out
Infrastructure, Soil & Water
native plants. (B) Conduct public outreach on ways to improve
Conservation District
residential buffers.
Expand "no mow zones" pilot program with Water Management and
Prevention
NA
Low
Water Management, Public Works -
$
5-10
No
explore other potential "no mow" areas and partners.
Watershed Planning
Require sediment & erosion control practices for critical areas on
Prevention
Construction Site Stormwater Runoff Control
Low
City -County Planning, County Stormwater
$
0-5
No
construction sites that are directly adjacent to buffers.
& Erosion Control
Improve concrete cutting and installation practices for Public Works
Prevention
Pollution Prevention/Good Housekeeping
Low
Public Works Operations, Stormwater
$
0-5
No
Operations projects (managing concrete slurry and washout controls).
for Municipal Operations
Quality
Advertise the Muddy Water Watch App on websites, social media, and
Prevention
Public Education and Outreach
Low
County Stormwater and Erosion Control
$
0-5
No
at public events.
Develop partnerships with outside organizations to acquire or secure
Prevention
NA
Low -Medium
Public Works - Watershed Planning
$$$
10-15
No
easements in riparian areas where a native vegetated buffer can be
protected or restored.
Conduct street sweeping in residential areas with cul-de-sacs that
Mitigation
Pollution Prevention/Good Housekeeping
Low
Public Works - Operations
$
0-5
No
have stormwater outfalls near a stream. Develop routes using GIS
for Municipal Operations
maps.
Use aerial photography to identify denuded areas or
Mitigation
Illicit Discharge Detection and Elimination
Low
Public Works - Stormwater Quality
$
0-5
No
sites with sediment and erosion issues.
Mitigate flow from older DOT roads by installing retrofits on DOT
Mitigation
NA
Medium
NCDOT
$$$
10-15
No
easements.
Educate road designers about better stormwater control practices.
Prevention
Public Education and Outreach
Low
City Transportation Department
$
5-10
No
33

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
Table 5 Priority and non -priority measures proposed for the Third Fork Creek TMDL Response Plan
Proposed Measure
Type of
NPDES Minimum Measure
Estimated Impact
Group(s) Responsible for Measure
Estimated
Implementation
Priority
Measure
on Reducing
Implementation
Cost to
Timeline
Turbidity/TSS
Implement
(years)
Measure
Evaluate the feasibility of a program to identify barren or unvegetated
Mitigation
NA
Low
Public Works -Watershed Planning
5-10
No
land where native plants may be established using simple techniques
such as seeding, planting, and live staking.
Targeted stormwater outfall program in both watersheds. Check
Mitigation
Illicit Discharge Detection and Elimination
Low
Public Works - Stormwater Quality
0-5
No
selected hot spot (<15) outfalls annually. Outfalls where previous
contamination issues have been observed are considered `hot spots'.
Targeted investigations and stream survey. Quickly assess field
Mitigation
Illicit Discharge Detection and Elimination
Low
Public Works - Stormwater Quality
0-5
No
conditions and identify illicit discharges in priority catchments.
Inspect outfalls, business corridors, and apartment complexes during
baseflow conditions. Implement a pilot program with existing staff to
conduct proactive investigations during the weekdays.
Query information from sanitary sewer inspection reports on
Mitigation
Illicit Discharge Detection and Elimination
Low
Public Works - Stormwater Quality
$
0-5
No
CityWorks using keywords for sediment issues (failing stream banks,
private and public sewer spills, etc.) for Stormwater Services to
investigate and report back to City Works users for tagging feedback.
Zoning Enforcement and Water Quality Investigator cross -training;
Mitigation
Illicit Discharge Detection and Elimination
Low
Public Works - Stormwater Quality; City-
$
0-5
No
enhancing communication between departments based on better
County Planning
understanding of each other's requirements but does not include the
authority to enforce each other's code.
Raise more awareness on preventing sediment from reaching creeks
Prevention
Public Education and Outreach
Low
Public Works - Stormwater Quality,
$
0-5
No
and storm drains. Target outreach efforts towards homeowners and
Watershed Planning
landscaping businesses.
Provide sediment control materials for stormwater roadside ditch
Prevention
Pollution Prevention/Good Housekeeping
Low - Medium
Public Works - Operations
$
0-5
No
work and install controls prior to ditch work. These sediment controls
for Municipal Operations
will be used for projects occurring longer than 1 day.
Estimated Costs: $$$ > $500,000, = $50,000 to $500,000, $ <$50,000. Estimated costs consider only the projected costs to the City and County departments.
34

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
15. Appendix B: Summary Table of Measures Not Included in the TMDL Response Plan
Table 6. Measures considered and not currently feasible for implementation in the Third Fork Creek TMDL Response Plan
Proposed Measure
Type of Measure
NPDES Minimum
Estimated Impact on
Group(s) Responsible for Measure
Estimated Cost to
Implementation
Measure
Reducing Turbidity/TSS
Implementation
Implement Measure
Timeline (years)
Conduct more enforcement of stream buffer rules in the Unified
Mitigation
NA
Low -Medium
City -County Planning
0-5
Development Ordinance.
Raise more awareness on reporting sediment discharges in creeks and
Prevention
Public Education and
Low
Public Works - Stormwater Quality,
0-5
storm drains by using an anonymous reporting app. [This idea overlaps with
Outreach
County Stormwater & Erosion
Muddy Water Watch App used by County Stormwater & Erosion Control]
Control
Consider requiring an S&E plan that developers submit with a small site plan
Prevention
Construction Site
Low -Medium
City -County Planning
5-10
along with a security deposit, or submit S&E plan and have 'sign if icant'fines
Stormwater Runoff
if developers do not implement S&E practices.
Control
Expand "Let It Grow" program - help stabilize stream banks by planting
Prevention
Public Education and
Low
Watershed Planning
0-5
native grasses along City -owned easements and creeks.
Outreach
Require limit on the area of mass grading for construction sites. Require a
Prevention
Construction Site
Medium -High
City -County Planning
10-15
phased approach for clearing and grading on construction sites
Stormwater Runoff
Control
Build partnerships with nurseries and other garden stores to set up
Prevention
Public Education and
Low
Public Works - Stormwater Quality
$
0-5
education kiosks and incentives.
Outreach
Place signs along trails (near creeks and sewer lines) to raise public
Prevention
Public Education and
Low
Trail Advisory Group
$
0-5
awareness on how and what to report (regarding cloudy water, turbidity,
Outreach
sediment) for sediment discharges.
Provide weekend answering service for Stormwater Pollution Hotline (560-
Mitigation
Illicit Discharge
Low -Medium
Public Works - Stormwater Quality
0-5
SWIM) or designate on -call staff members.
Detection and
Elimination
Install infiltration/biofilter swales along roadside ditches to reduce sediment
Mitigation
NA
Medium
NCDOT; Public Works - Operations
$$$
10-15
and erosion.
*Estimated Costs: $$$ > $500,000, = $50,000 to $500,000, $ <$50,000. Estimated costs consider only the projected costs to the City and County departments.
35

TMDL Response Plan for Turbidity in Third Fork Creek, Durham, NC
March 19, 2019
16. Appendix C: Measure of Incremental Progress
Implementation of any one measure may not directly impact turbidity levels or TSS concentrations in Third
Fork Creek. Implementing a combination of measures may reduce sediment levels to a much greater extent.
The following table lists the incremental progress that will be tracked for this TMDL Response Plan. This
tracking is in addition to any tracking performed through the monitoring program.
Table 7 Preliminary list of incremental progress
TMDL Response Plan Metric
Metric Reporting
Reporting Frequency
In -Stream Sediment Sources
Linear feet of stream restored and bank stabilized
Linear feet
Every five years
Construction/Development Source of Sediment
Number of storm drain protection kits purchased
Count
Annually
and provided to Public Works Operations Division
Number of "stop -work orders" issued for non-
Count
Annually
compliant construction sites
Number of Sediment & Erosion Control inspections
Count
Annually
conducted
Runoff from Impervious Surfaces and Direct
Dischar>?e
Number of curb miles of streets swept
Miles
Annually
Number of construction plans approved with green
Count
Every five years
infrastructure practices
Number of SCMs from WIP installed
Count
Every five years
Linear feet of streams walked in the Third Fork
Linear feet
Annually
Creek watershed
Educational Material Tracking
Number of flocculent -education handouts
Count
Annually
distributed to residents and businesses
Number of social media informational
Count
Annually
advertisements published
Public Participation Tracking
Number of storm drains adopted by residents
Count
Annually
36