09 O&M Plan for MS4s, Streets and Parking Lots

Operation and Maintenance Plan
for
Municipal Separate Storm Sewer Systems (MS4s), Streets
and Parking Lots

prepared for

NPDES # NCS000395, including Mecklenburg County, Charlotte
Mecklenburg Schools, Central Piedmont Community College
and the Towns of Cornelius, Davidson, Huntersville, Matthews,
Mint Hill, and Pineville

prepared By

Charlotte-Mecklenburg Storm Water Services
2145 Suttle Avenue
Charlotte, NCN 28208

November 2020

O&M Plan for Municipally Owned MS4s, Streets & Parking Lots - Permit # NCS000395

Standard Operating Procedure
Modification / Review Log

Version Effective Date Author Summary of Changes Approved By
1.0 11-30-2020 Rusty Rozzelle Original moved from SWMP Rusty Rozzelle

O&M Plan for Municipally Owned MS4s, Streets & Parking Lots - Permit # NCS000395

Table of Contents

Section 1: Introduction ...................................................................................................... 1
Section 2: MS4 Inventory ................................................................................................. 1
Section 3: Cleaning of Catch Basins, Pipes and Outlets ................................................... 2
Section 4: Street and Parking Lot Cleaning ...................................................................... 2
4.1 Street Cleaning ................................................................................................. 2
4.2 Parking Lot Cleaning ....................................................................................... 3
4.3 County Jurisdiction .......................................................................................... 3
Section 5: Winter Road Maintenance ............................................................................... 3
Section 6: Waste Disposal................................................................................................. 3
Section 7: Effectiveness .................................................................................................... 4

Tables:

Table 1: Summary of MS4 Inventory ...................................................................................... 1

Table 2: Average Pounds of Pollutants Removed and Costs for FY18, 19 and 20 ................. 4
O&M Plan for Municipally Owned MS4s, Streets & Parking Lots - Permit # NCS000395

1

Section 1: Introduction

This Operation and Maintenance (O&M) Plan has been prepared by Charlotte-Mecklenburg
Storm Water Services (CMSWS) to describe the O&M measures implemented by the co-
permittees, including Mecklenburg County, Central Piedmont Community College (CPCC),
Charlotte Mecklenburg Schools (CMS) and the Towns, for the municipally separate storm sewer
systems (MS4s), streets and parking lots that they own and/or operate as required by NPDES
Permit # NCS000395. This O&M Plan is also provided in Sections 8.7 and 8.8 of Mecklenburg
County’s Storm Water Quality Management Program Plan.

Each co-permittee is responsible for inspecting and maintaining the stormwater infrastructure
that they own and/or operate. This O&M Plan addresses the Permit requirements contained in
Section G, Pollution Prevention and Good Housekeeping for Municipal Operations, by
describing the activities and procedures the co-permittees implement to maintain their respective
MS4s so that the discharge of pollutants is reduced to the extent practicable.

Section 2: MS4 Inventory

CMSWS maintains an inventory of the MS4s owned and maintained by the co-permittees,
including major outfalls and receiving streams. Table 1 provides a summary of the information
contained in this inventory as of January 29, 2021. A more detailed inventory is available upon
request, including a map.

Table 1: Summary of MS4 Inventory
Jurisdiction Inlets All Outfalls
(≥12")
Major Outfalls
(≥36")
Industrial
Outfalls
Cornelius 5,236 828 27 0
Davidson 2,426 397 44 0
Huntersville 11,802 1,667 86 3
Matthews 4,846 740 31 3
Mint Hill 3,469 1,046 41 1
Pineville 2,834 549 7 0
Mecklenburg 3,122 1,822 41 4
CMS 5,361 836 15 0 / NA
CPCC 335 62 1 0 / NA
Total 39,431 7,947 293 11

The storm sewer system inventory is updated daily by Mecklenburg County’s GIS Department in
order to capture inlets and outlets added by new development. This is completed as part of their
ongoing process to update the impervious area coverage that is included in the stormwater billing
process. GIS staff use “Nearmap Aerial Imagery” to locate the new inlets and outlets. These
high-resolution, frequently updated aerial maps are widely used by both the public and private
sector to rapidly identify features on the ground with a very high degree of accuracy. EagleView
Pictometry is used to enhance images that are difficult to identify due to shadows and other
O&M Plan for Municipally Owned MS4s, Streets & Parking Lots - Permit # NCS000395

2

distortions. This patented high-resolution aerial image capture process uses low-flying airplanes
to photograph locations on the ground, depicting up to 12 oblique perspectives (shot from a 40
degree angle) as well as an orthogonal (overhead) view to produce a 360-degree view making
objects easier to recognize and interpret. Once the inlets and outlets are identified, a new point is
created in ESRI’s ArcGIS, including an object ID number, date collected, feature type (inlet or
outlet), and collection method. On a quarterly basis, GIS provides CMSWS with a list of the
newly collected storm sewer system features. These features are subsequently field validated by
CMSWS’s staff that input additional attribute information using the ArcGIS Collector
application, including the outfall type (major or minor, FES, endwall, exposed pipe, etc.), outfall
shape, outfall material, endwall material, and the diameter of the outfall. Staff also complete an
outfall inspection using the Cityworks Mobile App to record the condition of the outfall, dry
weather flows, and any other potential illicit discharges. Follow up actions are completed as
necessary to ensure the elimination of identified pollution sources. SOPs have been developed
for the storm sewer system mapping process, including follow up for potential pollution sources,
and are available upon request.

Section 3: Cleaning of Catch Basins, Pipes and Outlets

Each co-permittee performs catch basin and conveyance system cleaning as well as makes
repairs to the MS4 in identified problem areas. These problem areas are identified by staff based
on accumulations of leaves, trash, debris, blockages, flooding, etc. Each co-permittee maintains
records documenting the number of inlets, outlets and pipes cleaned and the pounds of trash,
sediment, and other pollutants removed as well as the estimated cost of the program. This data is
provided to CMSWS by July 31st of every year for use in evaluating program effectiveness and
for inclusion in the annual report to NCDEQ. If catch basin and conveyance system cleaning
reveals the presence of pollutants, such as oil, paint, chemicals, etc., CMSWS is notified
immediately for the initiation of follow up actions aimed at identifying and elimination pollution
sources.

Section 4: Street and Parking Lot Cleaning

Each jurisdiction maintains and enforces litter ordinances and maintains solid waste collection
and recycling services. Co-permittees also perform public education to encourage citizens to
properly dispose of waste and to recycle as many materials as possible.

4.1 Street Cleaning

Each co-permittee sweeps their municipal streets in identified problem areas. These problem
areas are identified by staff based on accumulations of leaves, trash, debris, blockages, flooding,
etc. The Town of Cornelius does the majority of its street cleaning through leaf vacuuming
services that run from November 1 through January 31 each year and use their street sweeper on
major thoroughfares. Co-permittees maintain records documenting the number of streets cleaned
and the pounds of trash, sediment, and other pollutants removed as well as the estimated cost of
the program. This data is provided to CMSWS by July 31st of every year for use in evaluating
program effectiveness and for inclusion in the annual report to the State.

O&M Plan for Municipally Owned MS4s, Streets & Parking Lots - Permit # NCS000395

3

4.2 Parking Lot Cleaning

Each co-permittee cleans parking lots in identified problem areas. These problem areas are
identified by staff based on accumulations of leaves, trash, debris, blockages, flooding, etc. It
may also be performed after special events and festivals where additional trash and other
pollutants are expected. Each co-permittee provides trash receptacles at public parking lots and
performs scheduled manual trash pick-up. Co-permittees maintain records documenting the
number of parking lots cleaned and the pounds of trash, sediment, and other pollutants removed
as well as the estimated cost of the program. This data is provided to CMSWS by July 31st of
every year for use in evaluating program effectiveness and for inclusion in the annual report to
the State.

4.3 County Jurisdiction

The County does not assume ownership or perform any maintenance activities on streets outside
the jurisdictions of the Towns and City of Charlotte. For County owned parking lots, litter is
picked up daily by maintenance staff, but no routine street sweeping activities are performed.

Section 5: Winter Road Maintenance

The co-permittees perform maintenance activities to ensure safe winter driving conditions on its
roads and parking lots. The following practices are employed by the co-permittees to reduce the
discharge of pollutants from these activities.
1. Minimize the use and optimize the application of sodium chloride and other salt (while
maintaining public safety) and consider opportunities for use of alternative materials.
2. Optimize sand and/or salt-brine solution rates through the use, where practicable, of
automated application equipment (e.g., zero velocity spreaders), anti-icing and pre-
wetting techniques and implementation of pavement management systems.
3. Prevent exposure of deicing product (salt, sand, or alternative products) to precipitation
by enclosing or covering storage piles. Implement good housekeeping, diversions,
containment or other measures to minimize exposure resulting from adding to or
removing materials from the pile. Store piles in such a manner as not to impact surface
water resources, groundwater resources, and wells.

Section 6: Waste Disposal

Each co-permittee is responsible for characterizing the waste that they collect from cleaning
activities and for proper disposal of this waste based on this characterization. CMSWS is
contacted if unusual conditions are observed with the collected waste, such as the presence of oil
or chemicals, unusual odors, discoloration, etc., so that testing can be performed prior to
disposal. Recycling or composting is the preferred method for handling organic waste. Any
disposal should occur at an approved landfill. The land application of this waste onto public or
private property is discouraged; however, if this does occur the application area must be a
minimum of 50 feet from any stream or other water body and proper erosion control measures
must be utilized to prevent off-site discharges.

O&M Plan for Municipally Owned MS4s, Streets & Parking Lots - Permit # NCS000395

4

Section 7: Effectiveness

The effectiveness of the activities described in Sections 3 and 4 above for streets, public parking
lots, and MS4s is evaluated annually based on cost and the estimated quantity of pollutants
removed. This data is summarized and included in the annual report provided to NCDEQ. Table
1 below includes an average of the data collected from FY2018 through FY2020 as a result of
this evaluation, including an estimate of the pounds of pollutants removed at 1,419,752 at a cost
per pound at $0.30. Based on this data, these BMPs are determined to be highly effective and
will therefore continue in use due to the significant number of pounds removed at a very low
cost. This determination is based on a report produced by R.C. Sutherland, P.E. in 2013 entitled
Clean Streets Mean Clean Streams that indicates an acceptable pollutant removal range is $3 to
$5 per pound.

Table 2: Average Pounds of Pollutants Removed and Costs for FY18, 19 and 20
BMPs Lbs. Removed Cost Cost/Lb.
Street Sweeping 1,044,077.67 $334,766.00 $0.32
Parking Lot Cleaning 22,241.33 $12,184.33 $0.55
Conveyance Systems Cleaning 353,433.33 $84,150.00 $0.24
TOTALS 1,419,752.33 $431,100.33 $0.30