HomeMy Public PortalAboutExhibit MSD 23 - Revised Stormwater PolicyMetropolitan St. Louis Sewer District
Statement of Policy
for
Maintenance of Stormwater Sewer Systems
1.0 Introduction
Adequate drainage in the Metropolitan St. Louis area is necessary to preserve and
promote the general health, welfare and economic wellbeing of the region.
Stormwater drainage is a regional feature that affects all governmental jurisdictions
and all parcels of property. This characteristic of drainage makes it necessary to
formulate a program that includes public and private involvement both from the
master planning of new improvements and the costs associated with maintenance and
replacement of existing improvements.
2.0 Definitions
Stormwater infrastructure consists of the following Systems:
Public Stormwater Systems – Stormwater infrastructure that is located in
easements with rights to MSD. Stormwater infrastructure that has been formally
dedicated to MSD for maintenance.
Private Stormwater Systems -- Stormwater infrastructure that is not located in
easements with rights to MSD, and is typically designed to serve an individual
property prior to connection to a public stormwater system. Stormwater
Infrastructure not dedicated to MSD for maintenance.
Non-Dedicated Stormwater Systems – Stormwater infrastructure that provides a
public service and serves more than one property. Typically systems not built per
MSD standards, not in dedicated easements, and undedicated to the District.
Examples may include a system built in a subdivision without permits or District
approval, or as-built drawings were not received.
Stormwater infrastructure consists of the following Assets and features:
Inlets – A stormwater structure that has a curb inlet, area inlet, or road grate that
allows stormwater runoff to enter the stormwater system. Inlets are
interconnected to the stormwater system via storm sewer piping. Inlets typically
need regular cleaning due to the accumulation of debris that is washed in off of
streets.
Stormwater sewers – Enclosed and typically underground piping that transports
stormwater runoff from properties and streets to streams.
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Improved Channels – Improved stormwater channels are open trapezoidal or
vertical walled channels designed to certain standards and typically constructed
from man-made structural materials, such as poured concrete, concrete block,
placed stone, or gabion baskets.
Unimproved Channels – Stormwater channels that have not been improved as
described above, such as natural streams, stone revetments, and grade controls.
Sinkholes – Natural depressions or collapsed areas formed by dissolution of
carbonate bedrock. Stormwater typically drains into the subsurface.
Improved Sinkholes – A sinkhole with an MSD approved drainage structure on
top.
Driveway Culverts – Storm pipes incorporated into driveways to allow storm
flows to travel through roadside ditches and gutters.
Road Culverts and Bridges – Engineered bridges and culverts designed to allow
roads to span rivers, streams and stormwater channels.
Roadside ditches or Gutters – Earthen or paved stormwater channels alongside
roads or curbed gutters alongside roads.
Swales – Shallow trough-like depressions designed to divert or channel
stormwater flows. Examples include ditches and other grading to direct flow to
specific areas, including MSD infrastructure.
Detention and Retention Basins – Stormwater basins often designed into
neighborhoods to capture stormwater drainage from the neighborhood stormwater
systems. They are designed to capture runoff for a limited period of time and
discharge into a larger public stormwater system or stormwater channel.
Stormwater BMP (best management practice) – a constructed stormwater feature
intended to reduce pollutants from stormwater discharges and improve surface
water quality.
Municipal Separate Storm Sewer System (MS4) – As defined in 10 CSR 20-
6.200: a MS4 is a conveyance or system of conveyances including roads and
highways with drainage systems, municipal streets, catch basins, curbs, gutters,
ditches, paved or unpaved channels, or storm drains designated and utilized for
routing of stormwater which, does not include any waters of the state; is
contained within the municipal corporate limits or is owned and operated by the
state, city, town, village, county, district, association, or other public body created
by or pursuant to the laws of Missouri having jurisdiction over disposal of
sewage, industrial waste, stormwater, or other liquid wastes; is not a part or
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portion of a combined sewer system; and is not a part of a publicly owned
treatment works as defined in 40 CFR 122.2.
Rivers and Streams – Natural waterways that drain watersheds.
3.0 Services
The following provisions summarize the District’s current policies and service levels
on Stormwater System Maintenance.:
3.1 Regulatory Authority and Oversight: Consists of work required to meet
Federal, State and local stormwater regulations and includes the following:
3.1.a Engineering Services: MSD’s Engineering Department provides services
to ensure the proper design, construction and functionality of existing and new
stormwater systems. These services include:
Plan review and permitting – All public or private sewerage and drainage
works proposed to be constructed, altered or reconstructed by an person or
corporation, public or private within the District Boundaries will require
review and approval by the District. This includes any altering of storm
drainage channel, site drainage or floodplain within the District;
Ensuring that all new sewage and drainage facilities are designed in
accordance with “Rules and Regulations and Engineering Design
Requirements for Sanitary Sewage and Stormwater Drainage Facilities”;
Ensuring that all new sewage and drainage facilities are constructed in
accordance with “MSD Standard Construction Specification for Sewers and
Drainage Facilities.”
3.1.b Environmental Services: MSD’s Engineering Department provides
services to ensure compliance with federal and state stormwater regulations. These
services include:
Overall service area oversight and coordination with St. Louis County and
municipalities within the District boundary, the Missouri Department of
Natural Resources, and the U.S. Environmental Protection Agency;
Activities required for compliance with the MS4 operating permit, including
stormwater management plan (SWMP) development, implementation, and
enforcement activities required for MSD to comply with the following
minimum control measures:
o Public Education and Outreach;
o Public Involvement and Participation;
o Illicit Discharge Detection & Elimination;
o Construction Site Stormwater Runoff Control;
o Post-construction Stormwater Management; and
o Pollution Prevention/Good Housekeeping for Municipal Operations;
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Development, implementation and enforcement of plan(s) necessary to
address the assumptions, requirements, waste load allocation, and load
allocation of any applicable total maximum daily load (TMDL);
All monitoring, recordkeeping, reporting, and applications necessary for
compliance with a MS4 Operating Permit.
3.2 Preventative Stormwater Maintenance: Stormwater infrastructure needs
periodic maintenance and inspection to assure it functions as intended and needed
improvements are identified. The following are maintenance service goals of the
District with respect to the Public Stormwater System:
Clean combined sewer inlets in the City of St. Louis and near County on a
two-year cycle;
CCTV inspection of storm sewers on a 10-year cycle;
Cleaning and repair of storm sewers as identified in inspections;
Visual inspection and maintenance of improved sinkholes as needed;
Visual inspection of storm inlets on a 10-year cycle;
Cleaning and repair of storm inlets as identified in inspections;
Inspection of improved channels and bridge culvert openings on a 2-year
cycle;
Cleaning of improved channels including bridge and culvert openings as
identified in inspections. Areas under bridges and culverts are not MSD’s
responsibility;
Maintenance of public stormwater BMP’s constructed by MSD or dedicated
to MSD for maintenance, including:
o Green infrastructure and basins (mowing; plantings; trash);
o Cleaning of hydro dynamic separators that were installed as part of
public street improvements;
Monthly inspection and maintenance of floodwall pump stations and gate
structures.
3.3 Customer and Emergency Calls: The District maintains a 24/7 call center and
responds to a number of stormwater problem calls. Response times range from four
(4) hours for emergency calls, to up to 30 days for less critical investigations. MSD
will respond to calls on both Public Stormwater Systems and Non-Dedicated
Stormwater Systems. MSD will not typically respond to calls on Private Stormwater
Systems. Response includes:
Stormwater problem investigation (i.e. local ponding or flooding) – District
engineers investigate localized or individual stormwater problems. Some
water solutions may be offered by the District if it involves reasonable
improvements to the Public Stormwater System. Some solutions may be the
property owner’s responsibility, such as grading or swales. In these cases the
District will work to help identify the solution.
Erosion Investigation – District engineers will investigate erosion issues.
Erosion is a natural phenomenon, and due to funding constraints, MSD is
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usually unable to resolve these issues. If an MSD System is determined to be
the cause of the issue, MSD will work to mitigate the problem. Engineers will
give advice to the property owner.
Cave-in (yard sinkhole) investigations – MSD personnel will investigate the
cause of cave-ins. The hole is typically flooded with dye and the Public
Stormwater System is checked to see if the dye is entering through a defect in
the public infrastructure. If so, MSD will make necessary repairs.
Street flooding - The District will respond and alleviate maintenance-related
street flooding as soon as possible.
Blocked inlets – The District will respond to blocked inlet calls and clean
inlets as necessary.
Broken or dislodged inlet tops - The District will typically respond within four
hours of call.
Blocked Creek Investigations - MSD will investigate blocked creek calls.
MSD will contract to remove debris if it is deemed a flooding threat such as a
fallen tree in public right of way. MSD will not be responsible to remove
typical debris or branches that are not considered a flooding hazard.
No Response Calls - MSD will not respond to some stormwater calls as they
are not considered part of the Public Stormwater System, and therefore, MSD
will not maintain these items. These include:
o Detention and Retention Basins – these are considered private and
their maintenance is the responsibility of the subdivision or
neighborhood.
o Maintenance and/or Cleaning of roadside ditches, bridges and roadway
or driveway culverts - These structures are not MSD’s responsibility
and typically fall to the municipality or private homeowner.
o Sink Holes - MSD will not clean natural sinkholes, sinkholes
improved with non-standard structures, or portions of improved
sinkholes below the public structure.
o Missouri State Highway Department - MSD will not maintain any
storm sewers located on State right-of-way unless they are integral
parts of the Public Stormwater System.
o Swales- MSD will not maintain swales.
o Trench Drains – MSD will not maintain trench drains.
o Weeds – MSD only cuts weeds on property owned by MSD, and not
on easements.
3.4 System Renewal and Repair: Continued system renewal and repair is an
essential part of keeping the Public Stormwater System functioning properly. Many
system improvements and repairs are identified as a result of MSD preventative
inspection program as well as customer investigations. These may include pipe
renewal, inlet repair or rehabilitation, small system additions as well as improved
channel repairs. Some jobs may be performed internally with District Staff and others
contracted through the MSD Engineering Department’s Infrastructure/Repair
program. Engineering has a number of engineers and field crews that manage and
inspect these repairs.
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MSD will renew and repair Public Stormwater Systems. Private Stormwater Systems
are the responsibility of the property owner. Non-dedicated Stormwater Systems may
be eligible for improvement if the property owners are willing to give easements and
dedicate the stormwater system to the District. Repair and Renewal monies are
limited and repairs are performed on a priority basis, based on need, cost and public
benefit.
3.5 Capital Improvement Projects: MSD does not collect a District-wide source of
funding for stormwater capital improvement projects.
4.0 Disputes
In the event a dispute arises as to whether a particular stormwater sewer system,
facility, structure, asset or feature or any part thereof should be maintained, repaired,
or replaced by the District pursuant to this Policy, the decision of the District’s
Executive Director shall be final. Any person or persons jointly or severally
aggrieved by such decision may appeal such decision in the manner provided for in
Section 12.110 of the District's Plan.