8_NCS000414_MS4 O&M Plan_20210708

MS4 OPERATIONS AND
MAINTENANCE PLAN
Updated May 2021

Town of Chapel Hill
MS4 O&M Plan
May 2021
Table of Contents
TABLEOF FIGURES........................................................................................................................................ 2
1 BACKGROUND..........................................................................................................................................3
2 MANUAL PURPOSE...................................................................................................................................3
3 DEFINITIONS............................................................................................................................................. 3
4 MAINTENANCE RESPONSIBILITY..............................................................................................................4
5 OPERATIONS AND MAINTENANCE PLAN.................................................................................................4
6 APPLICABILITY...........................................................................................................................................5
7 MAINTENANCE DETAILS...........................................................................................................................6
8 MS4 INSPECTIONS.................................................................................................................................... 7
9 PLAN IMPLEMENTATION..........................................................................................................................7
10 STAFF TRAINING..................................................................................................................................... 8
11 TRACKING SYSTEMS...............................................................................................................................8
12 STANDARD OPERATING PROCEDURE (SOP) FOR STORMWATER INLET INSPECTION AND CLEANING 8
TABLE OF FIGURES
Table 1 - Operations and Maintenance Plan Summary.................................................................................4
Page 2 of 9

Town of Chapel Hill
MS4 0&M Plan
May 2021
1 BACKGROUND
Under the Federal Clean Water Act and in compliance with the Town's MS4 NPDES permit, "Waters of the
United States" are to be protected from contamination. One way to protect "Waters of the United States"
is to provide maintenance of all storm sewer system components. The Town is responsible for those
components that are located within the Town's rights -of -way, such as pipes, inlets, and roadside ditches.
The Town is also responsible for some stormwater control measures. However, most of the stormwater
control measures are owned and maintained by private owners as private facilities.
2 MANUAL PURPOSE
This operation and maintenance plan addresses the requirement in MS4 Permit Part II.G. 2.f of the Town's
NPDES Permit No. NCS00414. Proper maintenance will help assure that:
• Stormwater drainage components operate as they were designed.
• Stormwater drainage systems are cleaned of pollutants that they trap, such as sediments and oils,
so that stormwater drainage systems are not overwhelmed and in so doing become pollutant
sources.
• Pollutant sources are removed, or minimized, prior to entering the Stormwater drainage system.
• Town -owned roads and parking lots are kept clean to minimize pollutant transport to surface
water.
3 DEFINITIONS
1. Stormwater Drainage System - Any mode of conveyance within the Town that allows or permits
the flow of Stormwater to waters of the United State. The conveyance can be opened or enclosed,
public, or private, and may contain non-stormwater discharges. The stormwater drainage system
includes all the infrastructure and natural drainage designs that are intended to collect, control,
and provide a method of conveyance, discharge, and treatment of Stormwater, including but not
limited to open channels (ditches, streams, swales), storm drainpipes, drainage boxes (catch
basins, drop inlets), detention basins, retention ponds, wetlands, outfalls, and treatment
stormwater control measures.
2. Public Stormwater Drainage System - That portion of the Stormwater Drainage System that is
located within the Town's rights -of -way or on Town -owned land, or outside of the Town's right-
of-way or other Town -owned land to the extent that a drainage easement legally conveying a
portion of the system on private property to the Town as evidenced by the written dedication and
acceptance of the same.
3. Private Stormwater Drainage System - That portion of the Stormwater Drainage System located
or private property that is not the legal responsibility of the Town.
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Town of Chapel Hill
MS4 0&M Plan
May 2021
4 MAINTENANCE RESPONSIBILITY
1. Public Stormwater Drainage System —The Town conducts periodic inspections for maintaining that
portion of the Stormwater Drainage System for which it is the legally responsible. There are ongoing
subwatershed studies being undertaken by an engineering consultant firm contracted by the Town to
help identify stormwater-related drainage and infrastructure problem areas in Town.
Information collected during these inspections is being used in evaluating the condition of the system
and in setting priorities for operation and maintenance work as well as capital improvement projects
(CIP). A stormwater CIP prioritization rating system was developed as part of the first subwatershed
study. The CIP rating system allows Town staff to place relative weights on the various criteria to help
in prioritizing CIP projects to undertake.
2. Private Stormwater Drainage System- It shall be the responsibility of the property owner to maintain
the operational characteristics of the Private Stormwater Drainage System located on their property,
including but not limited to all easements, channels, detention basins, retention ponds and other
impoundments, so that they continue to operate as they as they were originally designed.
3. NCDOT Right of Way
Most of the major thoroughfares in Chapel Hill are NCDOT roads. The Town provides some NCDOT
right-of-way maintenance support, but maintenance of the stormwater infrastructure along these
roads is an NCDOT maintenance responsibility.
5 OPERATIONS AND MAINTENANCE PLAN
The Town's operation and maintenance program for the MS4 shall have the following components:
• Maintenance activities, maintenance schedules, and long-term inspection procedures to reduce or
eliminate the discharge of pollutants from streets, roads, highways, municipal parking lots.
• Procedures for properly disposing of waste removed from the MS4 (such as dredge spoil, accumulated
sediments, floatable, and other debris).
TABLE 1- OPERATIONS AND MAINTENANCE PLAN SUMMARY
O &M Activity
Measurable Goals
Responsible Position/
Party
1
Inventory of
The Town shall continue to maintain a current
Stormwater Specialist/GIS
municipally owned
inventory of the facilities and operations owned and
Specialist
or operated facility
operated by the Town with the potential for
generating polluted stormwater runoff.
2
Operation and
The Town will maintain and implement, evaluate
Engineer III/Stormwater
Maintenance
annually, and update as necessary this operation
Specialist
(O&M) Plan
and maintenance (O&M) plan.
3
MS4 Inspection
The inspection schedule will be reviewed and
Stormwater Maintenance
updated in FY21. All assets will be inspected at least
Crew
once every S years and documented in a database.
Superintendent/Engineer
III
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Town of Chapel Hill
MS4 0&M Plan
May 2021
4
Street, roads, and
The Town shall continue to use a street sweeper as
Stormwater Maintenance
public parking lots
the primary means of reducing pollution. Street
Crew
maintenance
sweeper use shall be tracked in paper forms. Staff
Superintendent/Street
have been properly disposing of street debris at
and Solid Waste
approved facility and will continue to maintain this
Superintendent
practice.
5
Street, roads, and
The Town shall update the existing procedure in
Stormwater Maintenance
public parking lots
FY21 based on recommendation from Town facility
Crew
maintenance and
assessment undertaken by consulting engineering
Superintendent/Street
improvements
firm that has been awarded a contract by the Town
and Solid Waste
since October 2020.
Superintendent
6
Staff training
The Town shall develop and provide staff training on
Stormwater Specialist/
general stormwater awareness and implementing
Community Education
pollution prevention and good housekeeping
Coordinator
practices.
6 APPLICABILITY
This plan applies to the following Town owned/maintained facilities:
Facility/Activity
Possible Pollutant(s)
Fire Department, including 5 fire stations and a Training
Vehicle wash water, fire suppression
Rescue Center
chemicals, fuel leakage from emergency
generator, vehicle chemical leaks (e.g.,
antifreeze, oil, fuel etc.)
Streets
Trash, vehicle chemical leaks, deicing salt,
heavy metals, sediments
Stormwater conveyances
Yard debris, trash, vehicle chemical leaks
Town Parks and Recreation Facilities, including 3 pools, a
Pool chemicals, yard debris, pet waste,
community clay center, and 12 parks
pool backwash, chlorinated pool water,
fertilizer and pesticide application
Parking lots/decks (13), including 2 trash compactors
Dumpster leachate, trash, vehicle
chemical leaks, wash water spray from
dumpster
Other Town Facilities, including Town Hall, Chapel Hill
Yard debris, trash, vehicle chemical leaks,
Public Library, Old Town Hall, Police Department
fuel leakage from emergency generator
Housing Communities, including 12 neighborhoods
Yard debris, trash, vehicle chemical
leakages, pet waste
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Town of Chapel Hill
MS4 0&M Plan
May 2021
7 MAINTENANCE DETAILS
The Town has developed several measures to help prevent or reduce pollutants entering receiving waters
during storm events. These include:
• Integrated Pest Management Program (IPM) - The Town has adopted an IPM policy and
program as a comprehensive approach that gives priority to prevention and management of
pests including insects, weeds, and plant disease by the least toxic method. The policy will
reduce the environmental and health risks associated with pest management. Reduced loading
of toxics in stormwater runoff is one of the direct benefits of this program.
• Street Sweeping — The Town has two regenerative air (Elgin Crosswinds) sweeper trucks for
removal of sediments and pollutants from street surfaces with the following targets:
o Downtown streets — twice per week
■ Includes Franklin Street and nearby streets with high foot traffic
o Arterial streets — once per week
■ Includes major thoroughfares designed to move traffic through Town
o Residential streets — once every 6-8 weeks
■ Includes neighborhoods
The debris is sifted through a trommel to remove trash and other large objects. The sifted debris
is stored in the back lot at the Town Operations Center and then taken to a Solid Waste
Management facility for disposal.
• Inlet Clean -Out Program —Currently on an as -needed basis with more attention given to
ongoing problem locations.
During inclement weather, Streets and Construction Division staff are available to assist with
section maintenance. Two -person crews are assigned to a section of the Town to check for any
blockages or obstructions that are causing localized drainage and flooding issues.
Town also operates a vac truck, which is equipped with a "wander hose" attachment for the
removal of debris and sediments from inlets and pipes.
Prior to large forecasted rain events, the stormwater maintenance crew inspects structures and
streams with a history of localized flooding to remove obstructions. Examples include:
• S. Estes Drive in the vicinity of Willow Drive
• Camelot Village Apartments on S. Estes Drive
• Brookwood Community on S. Estes Drive
• South Estes public housing neighborhood on S. Estes Drive Extension near University
Place
• Cleland Road between Kendall Drive and Hayes Road
The stormwater maintenance crew also conducts biannual inspections of major creeks. The on-
going Town's subwatershed studies have identified drainage, flooding, and stormwater
infrastructure issues that will be addressed as resources become available.
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Town of Chapel Hill
MS4 0&M Plan
May 2021
• Reduction of Brine Runoff--- Town crews use a brine mixture for roadway salt application when
there is significant ice accumulation anticipated. Application is targeted to hills, stop sign and
intersection approaches and locations that tend to stay frozen due to daytime shading rather
than treatment of the full width and length of the paved street. The salt used for the brine
solution is stored in an enclosed concrete structure covered with a roof at the Town's Operation
Center, which is regulated under a separate Industrial NPDES Permit to prevent exposure to
direct precipitation.
• Emergency Maintenance- The Town may conduct emergency maintenance operations on any
portion of the stormwater drainage system to protect the common good. Emergency
maintenance includes maintenance necessary to remedy a condition which is potentially
damaging to life, property, or public roads and rights -of -way. In cases of emergency maintenance,
the Town is not obligated to replace structures and/or planting (tree and shrubs) placed with a
drainage easement. For emergencies, citizens are encouraged to always call 911. Calls are then
forwarded to the local Fire or Police Department and relayed to the Stormwater Management
Division.
8 MS4 INSPECTIONS
Developing and implementing a rigorous inspection program will be central to the successful
implementation of this plan. Inspection schedules and staff responsibilities will be formalized in the
documentation implementation, with coordination between the Stormwater Maintenance Crew
Superintendent and Stormwater staff.
The foundational procedure will be:
• inspection and maintenance of Town -owned stormwater control measures (SCM's) at least once
every 5 years;
• identifying priority assets for more frequent inspections;
• systematic tracking, reporting and an ability to use information, staff and financial resources as
efficiently and effectively as possible.
• perform annual comprehensive evaluation of the Stormwater Pollution Prevention Plan for Town
facilities.
9 PLAN IMPLEMENTATION
The Stormwater Management Division will take the lead with activities under this measure, and
coordinate with staff from other departments, and especially Fire, Recreation and Parks, and Building
Inspectors, to develop a strategy for operation and maintenance, evaluation, and targeted employee
training. Each department will be responsible for implementation with oversight and assistance provided
by the Stormwater Management Division.
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Town of Chapel Hill
MS4 0&M Plan
May 2021
10 STAFF TRAINING
The Town will continue to implement targeted training for all departments to improve employee
awareness of the corrective measures that are identified for the various operations and facilities. The
Stormwater Management Division will coordinate this training both internally and with other
departments. The Town has contracted an engineering consulting firm to develop Good Housekeeping
training programs for Town facilities. The trainings will begin in June 2021.
11 TRACKING SYSTEMS
The details and day-to-day running of the operation and maintenance program is managed through
multiple work order and documentation strategies, including:
• Work requests from residents through SeeClickFix
• Phone calls and emails from residents
• Paper street sweeping logs
• Notes written in a field notebook
Developing a centralized work order and documentation system is a priority for the Stormwater
program. The Stormwater Maintenance staff is working on a GIS app to better track the street sweeping
operations.
12 STANDARD OPERATING PROCEDURE (SOP) FOR
STORMWATER INLET INSPECTION AND CLEANING
Inlet inspection cleaning procedures should address both the opening and the inlet's interior.
Inlet inspection and cleaning procedures include the following:
1. Work upstream to downstream.
2. Clean sediment and trash off grate, if applicable.
3. Visually inspect the inside of the inlet to determine cleaning needs.
4. Inspect the inlet for structural integrity.
5. Determine the most appropriate euipment and method for cleaning the inlet.
a. Manually use a shovel to remove accumulated sediments, or
b. Use a high pressure hose to clean material out of the inlet while capturing the slurry with
a vacuum.
c. If necessary, after the inlet is clean, use the rodder of the vacuum truck to clean
downstream pipe and pull back sediment that might have entered the downstream pipe.
6. Properly dispose of collected sediments.
7. If illicit discharges are observed or suspected, notify the Stormwater Specialist, who will
implement the Town's IDDE plan.
8. At the end of each day, document location and number of inlets checked and cleaned, amount
of debris collected, and the debris disposal method.
9. Report additional maintenance or repair needs to the StormwaterMaintenance Supervisor.
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Town of Chapel Hill
MS4 0&M Plan
May 2021
Disposal of Screenings
Inlet cleanings from stormwater drainage systems may be disposed at any landfill that is permitted
by North Carolina Department of Environmental Quality or Orange County Solid Waste Department.
Screenings may need to be placed in a drying bed to allow water to evaporate before proper
disposal. In this case, ensure that screenings are managed to prevent pollution.
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