HomeMy Public PortalAboutCity of Medina SWPPP 052423
STORMWATER POLLUTION
PREVENTION PROGRAM
For Managing the City of Medina’s
Municipal Separate Storm Sewer
System
May 2023
Prepared for:
City of Medina
2052 County Road 24
Medina, MN 55340
From:
WSB
701 Xenia Avenue South
Golden Valley, MN 55416
Introduction
In 1990, the U.S. EPA created the Municipal Separate Storm Sewer System (MS4) Program to
address the concerns with stormwater pollution. In Minnesota, the program is administered by
the MPCA.
This program requires approximately 300 cities, townships, counties, watershed districts, and
large campuses such as universities, hospitals and prison complexes that operate their own
private roads and stormwater drainage systems to comply with the MS4 program.
MS4 permittees are required to develop stormwater pollution prevention programs (SWPPP),
educate the public about stormwater pollution, and engage citizens in solving local water
pollution problems. The six categories of required action, known as minimum control
measures, include:
1. Public education and outreach;
2. Public Participation and Involvement;
3. Illicit Discharge Detection and Elimination (illegal dumping into storm sewers
and ditches);
4. Construction Site Stormwater Runoff Control;
5. Post Construction Stormwater Management; and
6. Pollution Prevention and Good Housekeeping [in municipal operations such as
parks maintenance and public works].
The permit addresses concerns such as winter salt storage, construction site erosion and
sediment control, and runoff from new development. Every five (5) years, the MPCA requires
the permittees to renew their permit and make updates to their stormwater programs to remain in
compliance.
This binder includes the information the City uses to remain in compliance with this permit.
What is an MS4 and How to Protect our Lakes
If you ask an average citizen what an MS4 is they likely would not know what it was, but MS4 play into
daily life for each any every one of us whether you know it or not. MS4 stands for Municipal Separate
Storm Sewer System. Examples of this can be well known from roads, curb, stormwater drainage
systems, to less known but equally as important such as drainage ditches, conveyances and other man-
made channels that stormwater moves throughout our cities. The stormwater that moves through these
systems can be polluted, is untreated, and discharges directly to bodies of water such as lakes and rivers
that we use every day. These bodies of water are used for recreation and sometimes a source of drinking
water for people. Therefore, it is important to understand how daily activities can impact these water
sources.
Total maximum daily load (TMDL) is the amount of pollutants that a water body can absorb daily before
water quality standards are impaired. Minnesota currently has 6,168 bodies of water that are impaired
with some type of restriction whether it be sediment, nutrients, heavy metals, or bacteria. So, how can
your average citizen lower the pollutant load carried by these MS4 conveyances?
Start with your lawn, fertilizer can have a large impact on algae blooms and oxygenation of our lakes and
rivers. Apply fertilizers at the correct rate of application per acre listed on the bag. Fertilizers in
Minnesota are required to have less than .7% Phosphorus in the fertilizer mix. All fertilizer bags have a
three number reading that contains nitrogen, phosphorus, and potassium in that order. Every second
number on your fertilizer bag should have zero as the middle number, representing 0 phosphorus (ex 20-
0-13). When applying fertilizer, ensure that any excess fertilizer on the pavement is cleaned up
immediately to prevent washouts to stormwater discharge basins. Leaves and grass clippings can also
contain these nutrients, so it is pivotal to sweep after lawn mowing. It is also important to clean up animal
droppings to prevent nutrient loading of local water ways from excess pet waste.
Leaks and spills are sources of pollution that can be picked up and carried away with each rainfall event.
Vehicle maintenance can be a large source of leaking and spills. When working on vehicles, try to work
inside an area that is covered. Check to make sure that once work is done nothing has spilled or leaked.
Spilled chemicals need to be cleaned up with absorbents and swept up immediately. Any leaked materials
such as fuel, oil, solvents, or grease can carry unwanted chemicals to waterways that will damage water
quality. Labels on containers that say caution, warning, danger, or poison need to be disposed of at a
hazardous waste facility. Each county will have a hazardous waste drop off sites where chemicals or
spilled materials can be disposed of properly.
Salting practices on your property are also a great way to minimize water quality impacts at home. Salt
contains chloride which is a labeled impairment on fifty lakes and streams in Minnesota. Safe salting
practices are a great way to mitigate the amount of salt that ends up in stormwater conveyances. One cup
of salt will safely melt about 250 square feet of paved area and can be applied at that rate. Excess salt that
has accumulated once ice is gone is no longer functional. Extra salt materials can be swept up and
disposed of to prevent water quality damage and stop vegetation from dying off and degradation of
cement on your property.
These are all simple preventative actions that can be implemented by everyone to protect our lakes and
streams. Preventing pollutants from reaching these MS4 conveyances can uphold water quality for fishing
and recreation in the land of 10,000 lakes.
Standard Operating Procedure
1
Minimum Control Measure 1
Public Education and Outreach
1.1 IDENTIFYING PRIORITY TOPICS
The City of Medina has identified potential priority topics for public education, outreach, and
participation, primarily based on land use and overall population demographics. Consideration shall be
given to low income, people of color, and non-English speaking people.
Priority items for public education identified:
• Pet waste
• Salt Storage and Deicing Materials
• TMDLs
• Deicing materials
• Construction activities
• Post-construction activities
The City will evaluate their high priority education topics at least once during each five-year permit
term, and update as needed.
Coordination with and/or use of stormwater education between the City, the City of Loretto, and the
Minnehaha Creek Watershed District, the Elm Creek Watershed Management Organization, and the
Pioneer-Sarah Creek Watershed Management Organization outreach programs implemented will be
documented.
Standard Operating Procedure
2
1.2 DISTRIBUTION OF EDUCATIONAL MATERIALS
The City of Medina has identified a variety of opportunities to distribute educational materials to their
residents and business owners (Appendix A). On an annual basis the City distributes at least two (2)
educational information specifically selected for stormwater-related issues of high priority. At least once
each calendar year, the City shall distribute educational materials or equivalent outreach focused on
illicit discharge recognition and reporting illicit discharges to the City. The City is recommended to
evaluate the distribution methods used annually during the permit term and update as needed.
At least once each calendar year, the City shall distribute educational materials or equivalent outreach to
residents, businesses, commercial facilities, and institutions, focused on the following:
1. impacts of deicing salt use on receiving waters;
2. methods to reduce deicing salt use;
3. proper storage of salt or other deicing materials.
4. impacts of pet waste on receiving waters;
5. proper management of pet waste;
6. any existing City regulatory mechanism(s) for pet waste.
Distribution of educational materials and information will primarily be done through the City’s website,
a twice a year utility bill insert, an annual newsletter, and a stormwater-related event. The City of
Medina is recommended to evaluate the distribution methods used annually during the permit term and
update as needed.
1.3 IMPLEMENTATION OF EDUCATIONAL PROGRAM
The City has an educational program implementation method in place, consisting of:
a. Identification of a target audience
• Residents
• Local businesses
• Developers
• Students
• Employees
• Low-income residents
• People of color
• Non-native English-speaking residents
b. Designation of the responsible person(s) in charge of overall plan implementation
• Public Works Director
Standard Operating Procedure
3
c. Specific activities and schedules to reach measurable goals for each target audience
d. A description of any coordination with and/or use of other stormwater education and outreach
programs being conducted by other entities, as applicable
e. An annual evaluation to measure the extent to which measurable goals for each target audience are
attained.
Standard Operating Procedure
4
1.4 DOCUMENTATION
The City of Medina has a procedure to document the public education and outreach program. The City
is recommended to evaluate and assess the effectiveness of the education program annually, during the
permit term. The program documentation consists of the following:
a. Identification and description of any specific stormwater-related issues identified by the City
recorded during each year of the permit coverage.
b. Specific activities and schedules to reach measurable goals for each target audience.
c. Information for any coordination with and/or use of other stormwater education and outreach
programs being conducted by other entities, as applicable.
d. Annual evaluation of measurable goals.
e. All information required under the City’s education and outreach plan in item 16.7
f. Activities held, including dates, to reach each target audience
g. Quantities and descriptions of educational materials distributed, including dates distributed
h. Estimated audience (e.g., number of participants, viewers, readers, listeners, etc.) for each completed
education and outreach activity.
Process
a. After an educational document or event is disturbed or held, record brief information of the
document disturbed within the City’s SWPPP tracking Excel table to help expedite the annual
reporting process as well as the evaluation of the program’s effectiveness. Table 1 contains simple
attributes that can be used in the database.
b. Save all documents within the City’s network designated SWPPP folder using the same folder
structure as provided with the electronic SWPPP provided.
Standard Operating Procedure
5
Table 1. Example of Public Education & Outreach Tracking Table
Description of Activity:
Type of Material: brochure,
newsletter, utility bill insert,
newspaper ad, radio ad,
television ad, cable access
channel, stormwater-related
event, school
presentation/project, website,
other
Circulation/Audience:
residents, business owners,
developers, industrial,
students, other
Date of Activity:
Ex: Spring grass
clippings sweep up
reminder and memo City newsletter insert
Residents – 64,500
Business owners –5,000 4/2/2022
The City of Medina shall conduct an annual assessment of the public education program to evaluate
program compliance, the status of achieving the measurable requirements (activities that must be
documented or tracked as applicable to the MCM (e.g., education and outreach efforts, implementation
of written plans, etc.)) in Section 16 of the MS4 General Permit and determine how the program might
be improved. The City shall perform the annual assessment prior to completion of each annual report
and document any modifications made to the program because of the annual assessment.
City of Medina MS4 Calendar
Introduction
When it rains or when snow melts in our communities, the water travels on impervious surfaces.
Impervious surfaces are surfaces that don’t allow water to soak into it. Examples of these surfaces include
roads, sidewalks/trails, driveways, rooftops, and more.
Water travels on these surfaces into storm drains which directly discharge into lakes, rivers, streams, and
wetlands. As the water travels, it can pick up pollutants with it such as oils, metals, road salt, trash, and
more.
The system of storm drains that you see in your community is a municipal separate storm sewer system
(MS4). It consists of roads with drainage systems, catch basins, curbs, gutters, ditches, channels, etc.
These systems are owned or operated by a public entity. This can include cities, counties, military bases,
universities, and more. In Minnesota, these systems must satisfy the MS4 permit if they are at least one
of the following:
• Located in an urbanized area and used by a population of 1,000 or more
• Owned by a municipality with a population of 10,000 or more
• Have a population of at least 5,000 and the system discharges to specially classified bodies of
water.
The MS4 permit is designed to reduce the amount of pollutants entering state waters from stormwater
systems. Public entities that own or operate a MS4 permit are required to implement a Stormwater
Pollution Prevention Program (SWPPP) to reduce the amount of pollutants to the system. An effective
SWPPP has six components called Minimum Control Measures (MCMs).
Contacts
Name Title Department Phone Email
Steve
Scherer
Public Works
Director 763-473-8842 Steve.scherer@medinamn.gov
Jim Stremel City Engineer 612-419-1549 JStremel@wsbeng.com
Schedule
Month Topic Month Topic
January Salt Use July Smart Irrigation
February Pet Waste August Invasive Species
March Illicit Discharge September Pet Waste
April Adopt a Drain October Leaves
May Landscaping November Salt Use
June Fertilizers December Trash
January – Salt Use
To help melt snow and ice during the winter months, salt is applied to the roads. As the snow and ice
melts, it travels into stormwater systems. Because of salt, the concentration of Chloride has increased
in surface and ground water. Chloride does not degrade in soil and water, and it can create toxic
conditions for fish and other animals that live in our lakes and streams.
Tips for residents:
• Support local and state winter maintenance crews in their efforts to reduce their salt use.
• Work together with local government, businesses, schools, churches and non-profits to find
ways to reduce salt use in your community.
• Shovel. The more snow and ice you remove manually, the less salt you will have to use and the
more effective it will be.
• 15 degrees F is too cold for salt. Most salts stop working at this temperature. Use sand instead
for traction, but remember that sand does not melt ice.
• Slow down. Drive for the conditions and make sure to give plow drivers plenty of space to do
their work. Consider purchasing winter (snow) tires.
• Be patient. Just because you don’t see salt on the road doesn’t mean it hasn’t been applied.
These products take time to work.
• Apply less. More salt does not mean more melting. Use less than 4 pounds of salt per 1,000
square feet. One pound of salt is approximately a heaping 12-ounce coffee mug. Leave about a
3-inch space between granules. Consider purchasing a hand-held spreader to help you apply a
consistent amount.
• Sweep up extra. If salt or sand is visible on dry pavement it is no longer doing any work and will
be washed away. Use this salt or sand somewhere else or throw it away.
• Hire a certified Smart Salting contractor, visit the MPCA website for a list of certified
contractors.
• Watch a video. This video, produced by the Mississippi Watershed Management Organization,
provides tips to homeowners about more environmentally friendly snow and ice removal
— Improved Winter Maintenance: Good Choices for Clean Water
February – Pet Waste
When pet waste is left uncollected, it gets washed into the stormwater systems and into our lakes and
rivers. It then decays in the water, releasing ammonia and depleting oxygen levels. This is harmful to
fish and other animals. These nutrients also promote weed and algae growth, as well as elevated
bacteria levels (E. Coli) that can cause unsafe conditions for recreational activities.
Tips for residents:
• Don't forget a plastic bag during your walk
• Picking up your pet's waste and depositing it in a trash can keeps it from washing into our local
waterways
• Utilize pet waste stations if available or use your trash bin at home and remember to “Scoop
the Poop”
March – Illicit Discharge
Storm sewer systems carry water directly into our lakes, rivers, and wetlands. If anything other than
stormwater enters the system, it is an illicit discharge. Substances can include oil, chemicals, sediment,
and more.
Tips for residents:
• Take used oil to a recycle center or a fast Oil-Change business
• Wash your car on the grass
• Revegetate bare or eroding areas
• Return old paint to the store where you purchased it
• Secure your trash when placed on the street
• Take all old chemicals, including paints and automobile fluids, to the Household hazardous
waste collection events | Hennepin County
• Do not pour fats, oils, and grease into your sink or sewer
• Do not over fertilize your lawn
• Pump your septic tank every 4 years
• Report any hazardous spills immediately
April – Adopt a Drain
Adopt-a-Drain is a program where residents can adopt a storm drain in their neighborhood. They are
responsible to keep it clear of leaves, trash, and other debris to reduce water pollution. Residents
volunteer fifteen minutes, twice a month, for cleaner waterways and healthier communities. Sign up
online to Adopt a Drain in your neighborhood! Adopt-a-Drain - Minnesota
June – Fertilizers
It is important to schedule your lawn care maintenance during times that match the life cycle of
the turfgrass.
Tips for residents:
1. Do not add fertilizer too early in the spring. This may encourage the grass to grow
during a time when it should be slow or dormant.
2. Do not spray to control weeds when temperatures are warm. This increases the
likelihood of damaging the lawn.
3. Do not fertilize in hot mid -summer months. This can cause irreversible damage to your
lawn.
4. Crabgrass doesn't develop until late spring or early summer, so don't apply herbicide
used to prevent pre -emerging crabgrass in the fall.
5. For more information visit: Lawn care calendar | UMN Extension
July – Smart Irrigation
May – Landscaping
Many studies indicate that you and your neighbors believe having a lawn that is safe for the
environment is very important. Unfortunately, some lawn care practices can create water quality
problems. Many chemicals (nitrogen and phosphorus) found in fertilizers run off our properties into
local waterbodies and create algal blooms that make for cloudy water and remove oxygen. Some
simple things you can do to maintain your lawn and be safe for the environment are:
• Choose the right grass seed. Consider limiting lawn area and choose grass varieties that require
less maintenance.
• Don’t overwater. 1” of water per week is typically enough. Overwatering can lead to runoff
and contaminants making it into our groundwater
• Test your soil. The U of M Extension will test your soil and will provide you with
recommendations on your fertilizer needs. Test your soil and take the guesswork out of
fertilizer recommendations | UMN Extension
• Mow Smart. Mow grass 3” or higher. Cut no more than 1/3 of the blade to encourage longer,
stronger turf grass roots. Leave the clippings after mowing to provide a source of slow-release
nutrients. Remove grass clippings from streets, sidewalks, and driveways. NEVER dispose of
clippings in drainage areas, storm drains, wetlands or water bodies!
July is Smart Irrigation Month. Due to the peak water use because of warm temperatures, little rainfall,
and water restrictions, during the month of July it is important for the public to be aware of the value
of water-use efficiency.
Tips for residents:
• Install a smart sprinkler system
• Collect & save rainwater for smaller gardens
• Water at the right time according to your location
• Replace turf with native plants
• Adhere to city’s watering restrictions
August – Invasive Species
Did you know that invasive species cause $120 billion annually in damage nationwide? Invasive species
are species that are not native to Minnesota and cause economic and environmental harm by causing
the decline and extinction of native species; threaten fisheries, forestry and recreation; and reduce our
property values. Some of the invasive species include zebra mussels, Eurasian watermilfoil, common
buckthorn, and emerald ash borer. Invasive species are found on land and in the water.
Tips for residents:
• Use only local or certified hay and firewood
• Clean recreational equipment thoroughly
• Treat infestations on your property; methods vary by species
• Report new infestations to “Arrest the Pest” hotline - Arrest the Pest Flyer (state.mn.us)
September – Pet Waste
When pet waste is left uncollected, it gets washed into the stormwater systems and into our lakes and
rivers. It then decays in the water, releasing ammonia and depleting oxygen levels. This is harmful to
fish and other animals. These nutrients also promote weed and algae growth, as well as elevated
bacteria levels (E. Coli) that can cause unsafe conditions for recreational activities.
Tips for residents:
• Don't forget a plastic bag during your walk
• Picking up your pet's waste and depositing it in a trash can keeps it from washing into our local
waterways
• Utilize pet waste stations if available or use your trash bin at home and remember to “Scoop the
Poop”
October - Leaves
Leaf litter and grass clippings left on street and sidewalk are one of the contributors to algal blooms in
our lakes. When algae dies it decomposes at the bottom of our waterbodies and uses up oxygen that
fish and native plants need.
Tips for residents:
• Rake the leaves that have accumulated along your curb, sidewalk, alley, etc. Consider
organizing a community clean up for water quality to help others.
• Don’t put your leaves in the trash (it’s illegal) and don’t burn them. Burning leaves releases lots
of air pollution.
• Put your leaves in a backyard compost pile or bring them to a compost facility.
• Use leaves to mulch your garden and lawn. This helps your soil and reduces weeds.
• If available, consider curbside pickup by your garbage hauler.
November – Salt Use
To help melt snow and ice during the winter months, salt is applied to the roads. As the snow and ice
melts, it travels into stormwater systems. Because of salt, the concentration of Chloride has increased
in surface and ground water. Chloride does not degrade in soil and water, and it can create toxic
conditions for fish and other animals that live in our lakes and streams.
Tips for residents:
• Support local and state winter maintenance crews in their efforts to reduce their salt use.
• Work together with local government, businesses, schools, churches and non-profits to find
ways to reduce salt use in your community.
• Shovel. The more snow and ice you remove manually, the less salt you will have to use and the
more effective it will be.
• 15 degrees F is too cold for salt. Most salts stop working at this temperature. Use sand instead
for traction, but remember that sand does not melt ice.
• Slow down. Drive for the conditions and make sure to give plow drivers plenty of space to do
their work. Consider purchasing winter (snow) tires.
• Be patient. Just because you don’t see salt on the road doesn’t mean it hasn’t been applied.
These products take time to work.
• Apply less. More salt does not mean more melting. Use less than 4 pounds of salt per 1,000
square feet. One pound of salt is approximately a heaping 12-ounce coffee mug. Leave about a
3-inch space between granules. Consider purchasing a hand-held spreader to help you apply a
consistent amount.
• Sweep up extra. If salt or sand is visible on dry pavement it is no longer doing any work and will
be washed away. Use this salt or sand somewhere else or throw it away.
• Hire a certified Smart Salting contractor, visit the MPCA website for a list of certified
contractors.
• Watch a video. This video, produced by the Mississippi Watershed Management Organization,
provides tips to homeowners about more environmentally friendly snow and ice removal
— Improved Winter Maintenance: Good Choices for Clean Water
December – Trash
Trash on land frequently makes its way into our waterbodies. Trash such as cigarette butts, paper, fast
food containers, plastic grocery bags, cans and bottles, used diapers, construction site debris, old tires,
appliances, and more are significant pollutants to our Minnesota waterbodies.
Tips for residents:
• Throughout the year, pick up trash if you see it in your neighborhood.
• Make sure the lid on your garbage container is closed.
• Coordinate a neighborhood clean up
• Adopt a highway
Standard Operating Procedure
1
Minimum Control Measure 2
Public Participation and Involvement
2.1 IMPLEMENTATION OF PUBLIC PARTICIPATION/INVOLVEMENT
PROGRAM
The City of Medina has a public participation/involvement program implementation method in place,
consisting of:
a. Designation of the responsible person(s) in charge of overall plan implementation
b. Specific activities and schedules to reach measurable goals for each target audience
c. A description of any coordination with and/or use of other stormwater education and outreach
programs being conducted by other entities, as applicable
Process
a. The City of Medina will provide a minimum of one (1) opportunity annually for the public to
provide input on the adequacy of the SWPPP. The City will conduct at least one public meeting
annually and will provide public notice, per the City’s public notice requirements, in advance of the
meeting. The City shall provide this opportunity by posting a notification of the draft annual report
and contact information to review the draft report and SWPPP document.
b. The City will provide public access to the SWPPP, annual reports, and other documentation intended
to support the SWPPP.
c. The City will consider oral and written input submitted by the public to the City, regarding the
SWPPP.
Public Input
The City of Medina shall provide access to the SWPPP Document, annual reports, and other
documentation that supports or describes the SWPPP (e.g., regulatory mechanism(s), etc.) for public
review through:
• Available at the public event
Standard Operating Procedure
2
The City of Medina shall consider oral and written input regarding the SWPPP submitted by the public
by providing a minimum of one (1) public involvement activity that includes a pollution prevention or
water quality theme. The City shall provide the following public involvement activities:
• A cleanup event
• Medina Celebration Day
•
2.2 DOCUMENTATION
The City has a procedure to document the public participation and involvement program. The City is
recommended to assess the effectiveness of the program annually, during the permit term. The program
documentation consists of the following:
a. All relevant written input submitted by persons regarding the SWPPP.
b. All responses from the City to written input received regarding the SWPPP, including any
modifications to the SWPPP as a result of written input received.
c. Dates, attendance, and locations of events held for purposes of meeting permit requirements.
d. Notices provided to the public of any events scheduled to meet the permit requirements for public
input and consideration.
Process
a. After a public involvement event is held, record brief information of the document disturbed within
the City’s SWPPP tracking Excel table to help expedite the annual reporting process as well as the
evaluation of the program’s effectiveness. Table 2 contains simple attributes that can be used in the
database.
b. Save all documents within the City’s network designated SWPPP folder using the same folder
structure as provided with the electronic SWPPP provided.
Standard Operating Procedure
3
Table 2. Example of Public Participation &Involvement Tracking Table
Description of Activity:
Date of Activity: Description of Any Input Received:
Ex: Annual public meeting, combined
with City Council meeting 2/2/2022 None
The City of Medina shall conduct an annual assessment of the Public Participation/Involvement program
to evaluate program compliance, the status of achieving the measurable requirements (activities that
must be documented or tracked as applicable to the MCM (e.g., public input and involvement
opportunities, etc.)) in Section 17 of the MS4 General Permit and determine how the program might be
improved. The City shall perform the annual assessment prior to completion of each annual report and
document any modifications made to the program because of the annual assessment
Standard Operating Procedure
1
Minimum Control Measure 3
Illicit Discharge Detection and Elimination
3.1 OBJECTIVES OF THE SOPS
This manual is intended to provide guidance on Illicit Discharge Detection and Elimination (IDDE) as
follows:
• Provide guidance to communtiies regarding commonly found illicit discharges.
• Provide guidance to communities for prioritizing areas where illicit discharges are commonly
found.
• Provides guidance in implementing a pet waste and salt storage regulatory mechanism.
o Provide tools that require owners or custodians of pets to remove and properly dispose of
feces on the City’s owned land areas.
o Provide tools that require proper salt storage at commercial, institutional, and non-
NPDES permitted industrial facilities. At a minimum, the regulatory mechanism(s) must
require the following:
▪ designated salt storage areas must be covered or indoors;
▪ designated salt storage areas must be located on an impervious surface; and
▪ implementation of practices to reduce exposure when transferring material in
designated salt storage areas (e.g., sweeping, diversions, and/or containment).
• Provide tools for response to reported illicit discharges
3.2 LOCATING PRIORITY AREAS
A map has been provided within the SWPPP that identifies potential priority areas for detecting illicit
discharges based on land use. The methodology for further establishing priority areas is detailed in
Section 3.3.1 “Review of Available Information”. The City of Medina is recommended to complete the
prioritization at least once during each five-year permit term. The City will use the Public Works
Director as the responsible person(s) for investigating, locating, and eliminating an illicit discharge.
3.3.1 Review of Available Information
Activities and Definition
Priority areas for IDDE will vary depending on water quality conditions, land use associated with
business or industrial activities, etc. A relatively simple desktop assessment of available community
information can provide many clues as to where illicit discharges may be occurring for basing the
prioritization.
Standard Operating Procedure
2
The definition of illicit discharge includes any discharge to the MS4 storm sewer that is not stormwater
including: leaking sanitary sewers or water mains, illegal sewage connections, illegal floor drain
connections, seasonal draining of swimming pools (pools are recommended to be dechlorinated prior to
discharge), break-out from failing septic systems, discharge of vehicle/equipment washing into the storm
sewer, restaurant discharge including grease, cleaning solution, grass clippings, fertilizer, pesticides,
salt, spills and dumping (Appendix A).
Maintain the following regulatory mechanism that prohibits non-stormwater discharges into the City’s
MS4:
• Ordinance
Preparation
The following is a list of resources that should be collected and reviewed and a brief description of
factors to consider during the prioritization process:
a. Zoning Maps
Industrial areas with high density development may have a high illicit discharge potential. The City
of Medina will target these industrial based land uses and inspect the outfalls within these areas at
least annually. As appropriate, commercial areas including bars, restaurants, grocery stores,
shopping malls, automobile shops, carpet cleaners, ready-mix and bituminous plants, and sand and
gravel pits may be targeted for illicit discharges.
b. Locations of Previous Illicit Discharges
Areas with historical illicit discharge reports or previous citizen complaints may be considered as
high priority. The City currently does not have areas of known illicit discharges.
c. High Density of Known Outfalls per Stream Mile
Areas with a high density of outfalls are considered high priority. These outfalls within the City of
Medina are within the industrial base land use of the City and will be inspected annually.
d. Age of Infrastructure/Development
Older areas of the community could be considered a high priority if regular IDDE action is needing
to take place in these locations. Currently the City does not consider these a high priority.
e. Location of Public Sanitary Sewer/Age of Sewer/Date of Separation
Older areas that were put on public sewer or separated long ago should be considered high priority.
No areas in the City exist where sewer was combined where illicit discharges may be present.
f. Location of Areas on Septic Systems
Standard Operating Procedure
3
Older areas on septic systems should be considered high priority.
Maintain a storm sewer map system that includes:
• All pipes 12 inches or greater in diameter, including stormwater flow direction in those pipes
• Outfalls, including a unique identification (ID) number, and an associated geographic
coordinate
• Structural stormwater BMPs that are part of the City’s small MS4
• All receiving waters
g. Water Quality Information
Areas with poor water quality should be considered high priority.
h. Areas that Drain to Public Beaches
These areas should be designated as high priority for public health and economic reasons.
The City of Medina shall incorporate illicit discharge detection into all inspection and maintenance
activities conducted.
The City shall maintain a written or mapped inventory of priority areas the City identifies as having a
higher likelihood for illicit discharges. At a minimum, the City shall evaluate the following for potential
inclusion in the inventory:
• Land uses associated with business/industrial activities;
• Areas where illicit discharges have been identified in the past; and
• Areas with storage of significant materials that could result in an illicit discharge
Review and field check other structures such as catch basins, culverts, pipes, ditches, drain manholes,
etc.
Collect dry weather inspection information whenever possible. Dry weather discharge information can
either be collected on the paper forms for manual entry into a separate database at a later time, or can be
directly entered into a database on a laptop or the data logger on-site.
Documentation
The City of Medina shall maintain a written or mapped inventory of priority areas the City identifies as
having a higher likelihood for illicit discharges.
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3.3 DETECTION PROCESS
Long-term, regular inspections of outfalls are a primary part of an effective IDDE program. Regular
inspections will not be significantly different from inspections conducted during mapping or in response
to MCM 6 inspections. The major difference from mapping inspections will be that a crew or inspector
will have historical data to work with to make assessments. These inspections can be recorded in the
City’s Cartegraph database or paper forms can be filled out in the field then integrated electronically at
the end of the day.
Most public works crews conduct their regular duties in and around the storm drain system. A Program
Manager may elect to have crews conduct IDDE inspections on a formal basis (actually bringing an
inspection form and equipment) while performing other municipal work, or the Program Manager may
elect to have crews informally “keep a look out” for illicit discharges. If an employee observes evidence
of an illicit discharge during an informal or non-routine inspection without Cartegraph or a paper
inspection form available, they should collect as much information about the potential illicit discharge as
possible then contact their supervisor so that appropriate action can be taken.
It is important to collect as much information as possible at the time of initial observation because of the
likelihood that a discharge may be transitory or intermittent. Initial identification of the likely or
potential sources of the discharge is also very important. Both the IDDE Guidance (Appendix B) and
IDDE Fact Sheet (Appendix C) can be used to assist in the detection process.
Once an illicit discharge has been reported or detected through an inspection, the next step is to locate
the source. Selection of tracing techniques will depend on the type of illicit discharge detected, the
information collected during initial discovery and observation (whether through an inspection by a
municipal employee or through a citizen call-in), and the resources/technology available to the
municipality. A single technique may be used or several techniques may need to be combined to
identify the source of the discharge. The three types of discharges are as follows:
a. Transitory illicit discharges: Typically one-time events resulting from spills, breaks, dumping, or
accidents. Transitory illicit discharges are often reported to an authority through a citizen
complaint line or following observation by a municipal employee during regular duties. Because
they are not recurring, they are the most difficult to identify, trace, and remove. The best method
to reduce, or eliminate before they occur, transitory discharges is through general public education,
education of municipal response personnel, tracking of discharge locations, and enforcement of an
illicit discharge ordinance.
b. Intermittent illicit discharges: Occur occasionally over a period of time (several hours per day, or a
few days per year). Intermittent discharges can result from legal connections to the storm drain
system, such as a legal sump pump connection that is illegally discharging anything other than
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5
groundwater. Intermittent discharges can also result from activities such as drum washing in
exterior areas. These types of discharges are less likely to be discovered, and are more difficult to
trace and remove because they generally occur on private property and require probable cause
and/or a search warrant for further investigation. These discharges can have large or small impacts
on waterbodies depending on pollutant content and the size of the receiving water body.
c. Continuous illicit discharges: Typically the result of a direct connection from a sanitary sewer,
overflow from a malfunctioning septic system, inflow from a nearby subsurface sanitary sewer that
is malfunctioning, or an illegal connection from a commercial or industrial facility. Continuous
illicit discharges are usually easiest to trace and can have the greatest pollutant load (CWP 2004).
The investigative techniques used will depend on whether or not a potential source location was
identified during the initial observation. Investigative techniques are as follows:
a. Potential source identified: If a potential source for the illicit discharge was initially identified, steps
should be taken to investigate the potential source site, such as inspecting the site and storm drain
system in the vicinity of the site. If floor drains, sumps, or other suspect discharge locations are
observed during this inspection, dye testing, smoke testing, electronic location of subsurface pipes,
or televising may be used. These techniques should definitively show whether the suspect site was
the source of the illicit discharge.
b. Potential source not identified: If no source site is suspected, and only the general area of the illicit
discharge is known, it may be possible to trace the evidence of the illicit discharge by visual
inspection of the storm drain access points. If this catch basin/manhole inspection technique is not
fruitful, some interim steps could be taken to try to trap water from an intermittent discharge. For
example, sand bagging and damming or block testing of selected storm drain access points,
combined with installation of an optical brightener trap to assess if detergents are present in a
discharge, can help reveal the source of the discharge. If these techniques have no positive result (no
water pools behind the weir or sand bag), the discharge was likely transitory (one time only), and it
may not be possible to determine its origin. In this case, the location of the originally reported illicit
discharge should be added to a regular inspection program to provide for the possibility of future
incidents. If the original report of the illicit discharge was severe or gross pollution, then smoke
testing or televising of the storm drain system may be warranted.
If clean-up is required, use the following procedures:
1. For Non-Emergency Situations: Follow the Illicit Discharges and Connection Enforcement
policy outlined in the City’s Enforcement Response Plan. The City of Medina requires the
responsible party to clean up illicit discharges. If they are unable or unwilling, the City will
utilize a street sweeper, vac truck, floor-dry, or other means, as needed.
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2. For Spills and Emergency Situations: Follow the City’s Spill Response Plan. The City
follows their spill response plan which includes assistance from the fire department.
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3.4 CITIZEN CALL-IN PROGRAM
Activities and Definition
A citizen call-in program is an effective way to identify illicit discharges. To maximize the
effectiveness of citizen call-ins, dispatch personnel should be instructed on the use of the IDDE
inspection form in order to collect as much information as possible at the time of the report. If the
report is a result of a spill or emergency situation the caller should be directed to call 911. Spill
response procedures can be found in MCM 6 section of this SWPPP program. Dispatch personnel
should also be instructed as to where to direct the information gathered from the tracking sheet so that
appropriate action is taken.
Preparation
Have a system in place to receive phone calls and collect information regarding suspected illicit
discharges.
Process
a. The City of Medina will utilize the “Citizen Complaint” section of the IDDE paper inspection form
during the time of the call.
b. The Fire Chief should be contacted for hazardous spills or emergency situations.
a. Promptly investigate reported incidents.
b. If an illicit discharge of unknown source is confirmed, follow the procedure of tracing illicit
discharges.
c. If an illicit discharge known source is confirmed:
1. For Non-Emergency Situations inform the violator that the illicit discharge needs to
discontinue. This may require fixing a cross-connection, incorporating Best Management
Practices, repairing a faulty piece of equipment, etc.
2. For Spills and Emergency Situations: Follow the City’s Spill Response Plan.
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3.5 OPPORTUNISTIC ILLICIT DISCHARGE OBSERVATION
Activities and Definition
The opportunity to locate and document illicit discharges can occur during normal work activities by
any of the City staff or inspectors. By offering the proper training to appropriate city employees and
inspectors, they will be ready to actively locate illicit discharges and respond in the proper manner to
issue penalties and make sure appropriate cleanup occurs.
Preparation
Be alert for potential illicit discharges to the municipal stormwater system while going about normal
work activates.
Process
a. Call the appropriate authority (i.e. department head, stormwater specialist, or a supervisor).
b. Assess the general area of the illicit discharge to see if the City can identify its source.
c. Whenever possible, take photographs of the suspected illicit discharge.
d. Responding personnel will complete the following:
1. Create a task using the City’s Cartegraph system and fill out the electronic form or use the
paper inspection form, if Cartegraph is unavailable.
2. Obtain sample for visual observation and complete and outfall inspection form, if applicable.
3. Follow the procedure of IDDE – Detection Process.
e. If clean-up is required, use the following procedures:
1. For Non-Emergency Situations: follow the Illicit Discharges and Connection Enforcement
policy outlined in the City’s Enforcement Response Procedures.
2. For Spills and Emergency Situations: follow the City’s Spill Response Plan.
Documentation
a. File all completed forms in the City’s system.
b. Document any further action taken.
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3.6 TRACKING ILLICIT DISCHARGES
Developing a long-term tracking program can help Program Managers better understand the origins of
illicit discharges and identify maintenance issues for the storm drain system structures. A tracking
program will also facilitate evaluation of the overall IDDE program and will expedite annual reporting.
An effective tracking program should address illicit discharge and maintenance issues resulting from the
following:
1. Citizen complaints
2. Opportunistic inspections
3. Regular longer term inspections
4. Enforcement actions taken for illicit discharges
Process
a. The City of Medina shall maintain written procedures for investigating, locating, and eliminating the
source of illicit discharges. The procedures shall include:
1. A timeframe in which the City will investigate a reported illicit discharge
i. Reports are investigated immediately and within one business day
2. Use of visual inspections to detect and track the source of an illicit discharge
3. Tools to investigate and locate an illicit discharge.
b. Tools to investigate and locate an illicit discharge shall include:
1. Mobile cameras
2. Collecting and analyzing water samples
3. Dye testing
c. Save all documents within the City’s network designated SWPPP folder using the same folder
structure as provided with the electronic SWPPP provided.
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3.7 TRAINING
Activities and Definition
Training of City staff will be important so that they are aware of the importance of Illicit Discharge
Detection and Elimination. This includes knowledge in identifying illicit discharges and procedures to
report and document them.
Training of field staff will as well be important in identifying illicit discharges and procedures to report
and document them. At least once each calendar year, the City shall train all field staff in illicit
discharge recognition (including conditions which could cause illicit discharges) and reporting illicit
discharges for further investigation. Staff will be trained through in-person presentations and field
training.
Previously trained individuals shall attend a refresher-training every three (3) calendar years following
the initial training .
The following list gives the yearly training required for departments and the people involved:
a. Employees of City owned or operated facilities:
Including water quality impacts associated with illicit discharges and improper disposal of waste.
b. MS4 engineers, development and plan review staff, land use planners:
Post-construction control requirements and associated BMPs.
c. Field Staff:
Identification, investigation, termination, cleanup, and reporting of illicit discharges.
d. Office Staff:
Illicit discharge reporting.
e. Field and Other Staff:
Implementation of the construction and post-construction stormwater management program,
including: permitting, plan review, inspections, and enforcement.
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Documentation
The City of Medina shall document the following relating to MCM 3:
a.Date(s) and location(s) of IDDE inspections conducted in accordance with permit items 18.7 and
18.11
b.Reports of alleged illicit discharges received, including date(s) of the report(s), and any follow-up
action(s) the City takes
c.Date(s) of discovery of all illicit discharges
d.Identification of outfalls, or other areas, where illicit discharges have been discovered
e.Sources (including a description and the responsible party) of illicit discharges (if known)
f.Action(s) the City takes, including date(s), to address discovered illicit discharges
The City of Medina shall document training relating to permit item 18.8 and 18.9 including the
following:
a.General subject matter covered
b.Names and departments of individuals in attendance
c.Dates of each event
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3.8 ENFORCEMENT RESPONSE PROCEDURE
Activities and Definition
To the extent allowable under state or local law, the City of Medina shall develop, implement, and
enforce a regulatory mechanism(s) that prohibits non-stormwater discharges into the City’s MS4, except
those non-stormwater discharges authorized in item 3.2.
The City shall maintain written enforcement response procedures (ERPs) to compel compliance with the
regulatory mechanism(s). Such enforcement tools include timeframes to complete corrective actions and
the name or position title of responsible person(s) for conducting enforcement. The following
enforcement tools are used:
a. Verbal warning
b. Notice of violation
c. Abatement
d. Restoration of affected property
e. Fine
Documentation
The City shall document the following relating to ERPs:
a. Name of the person responsible for violating the terms and conditions of the City’s regulatory
mechanism(s)
b. Date(s) and location(s) of the observed violation(s)
c. Description of the violation(s)
d. Corrective action(s) (including completion schedule) that the City issued
e. Referrals to other regulatory organizations (if any)
f. Date(s) violation(s) resolved.
The City shall conduct an annual assessment of the IDDE program to evaluate program compliance, the
status of achieving the measurable requirements (activities that must be documented or tracked as
applicable to the MCM (e.g., trainings, inventory, inspections, enforcement, etc.)) in Section 18 of the
MS4 General permit and determine how the program might be improved. The City shall perform the
annual assessment prior to completion of each annual report and document any modifications made to
the program because of the annual assessment.
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3.9 REFERENCES
Center for Watershed Protection. 2004. Illicit Discharge Detection and Elimination: A Guidance Manual
for Program Development and Technical Assessments. Center for Watershed Protection, Ellicott
City, MD & University of Alabama, Tuscaloosa, AL.
Sargent, D. and W. Casonguay. 1998. An Optical Brightener Handbook. Prepared for: The Eight Towns
and the Bay Committee. Ipswich, MA. Available at:
http://www.naturecompass.org/8tb/sampling/index.html.
Waye, D. 2003. A New Tool for Tracing Human Sewage in Waterbodies: Optical Brightener
Monitoring. Northern Virginia Regional Commission. Annandale, VA. Available online
http://www.novaregion.org/pdf/OBM_Abstract2.pdf.
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APPENDIX A
DEFINITIONS
Authorized Enforcement Agency: the City of Medina.
Best Management Practices (BMPs): schedules of activities, prohibitions of practices, general good
housekeeping practices, pollution prevention and educational practices, maintenance procedures, and
other management practices to prevent or reduce the discharge of pollutants directly or indirectly to
stormwater, receiving waters, or stormwater conveyance systems. BMPs also include treatment
practices, operating procedures, and practices to control site runoff, spillage or leaks, sludge or water
disposal, or drainage from raw materials storage.
Clean Water Act: The federal Water Pollution Control Act (33 U.S.C. § 1251 et seq.), and any
subsequent amendments thereto.
Construction Activity: Activities subject to NPDES Construction Permits. These include construction
projects resulting in land disturbance of one acre or more. Such activities include but are not limited to
clearing and grubbing, grading, excavating, and demolition.
Hazardous Materials: Any material, including any substance, waste, or combination thereof, which
because of its quantity, concentration, or physical, chemical, or infectious characteristics may cause, or
significantly contribute to, a substantial present or potential hazard to human health, safety, property, or
the environment when improperly treated, stored, transported, disposed of, or otherwise managed.
Illegal Discharge: Any direct or indirect non-stormwater discharge to the storm drain system, except as
exempted in this ordinance.
Illicit Discharge Types:
Transitory Illicit Discharges: Typically one-time events resulting from spills, breaks, dumping,
or accidents. Transitory illicit discharges are often reported to an authority through a citizen
complaint line or following observation by a municipal employee during regular duties.
Because they are not recurring, they are the most difficult to identify, trace, and remove. The
best method to reduce transitory discharges is through general public education, education of
municipal response personnel, tracking of discharge locations, and enforcement of an illicit
discharge ordinance.
Intermittent Illicit Discharges: Occur occasionally over a period of time (several hours per
day, or a few days per year). Intermittent discharges can result from legal connections to the
storm drain system, such as a legal sump pump connection that is illegally discharging anything
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other than groundwater. Intermittent discharges can also result from activities such as drum
washing in exterior areas. These types of discharges are more likely to be discovered, and are
less difficult to trace and remove, but can still present significant challenges. These discharges
can have large or small impacts on waterbodies depending on pollutant content and the size of
the receiving water body.
Continuous Illicit Discharges: These are typically the result of a direct connection from a
sanitary sewer, overflow from a malfunctioning septic system, inflow from a nearby subsurface
sanitary sewer that is malfunctioning, or an illegal connection from a commercial or industrial
facility. Continuous illicit discharges are usually easiest to trace and can have the greatest
pollutant load (CWP 2004).
Illicit Connections: An illicit connection is defined as any drain or conveyance, whether on the surface
or subsurface, which allows an illegal discharge to enter the storm drain system including but not limited
to any conveyances which allow any non-stormwater discharge including sewage, process wastewater,
and wash water to enter the storm drain system and any connections to the storm drain system from
indoor drains and sinks, regardless of whether said drain or connection had been previously allowed,
permitted, or approved by an authorized enforcement agency or, any drain or conveyance connected
from a commercial or industrial land use to the storm drain system which has not been documented in
plans, maps, or equivalent records and approved by an authorized enforcement agency.
Industrial Activity: Activities subject to NPDES Industrial Permits as defined in 40 CFR, Section
122.26 (b)(14).
Inlet: The location at which the water enters the holding area (i.e. stormwater detention pond).
Minnesota Pollution Control Agency (MPCA): The Minnesota Pollution Control Agency is a
Minnesota state agency that monitors environmental quality, offers technical and financial assistance,
and enforces environmental regulations for the State of Minnesota.
Municipal Separate Storm Sewer Systems (MS4): A municipal separate storm sewer system is a
conveyance or system of conveyances that is owned or operated by a public entity (which can include
cities, townships, counties, military bases, hospitals, highway departments, universities, etc.) and is
designed or used for collecting or conveying stormwater, which are not part of a publicly owned
wastewater treatment system.
National Pollutant Discharge Elimination System (NPDES) Stormwater Discharge Permit: A
permit issued by EPA (or by a State under authority delegated pursuant to 33 USC § 1342 (b)) that
authorizes the discharge of pollutants to waters of the United States, whether the permit is applicable on
an individual group, or general area-wide basis.
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Non-Stormwater Discharge: Any discharge to the storm drain system that is not composed entirely of
stormwater.
Outfall: The point source where the MS4 discharges to a receiving water, or the stormwater discharge
permanent leaved the MS4 boundary (not including runoff or conveyances that connect segments of the
same stream or water systems). These locations are labeled Inflow structures on the City’s Cartegraph.
Outlet: The location at which the water leaves the holding area (i.e. stormwater detention pond).
Person: Any individual, association, organization, partnership, firm, corporation or other entity
recognized by law and action as either the owner or as the owner’s agent.
Pollutant: Anything which causes or contributes to pollution. Pollutants may include, but are not
limited to: paints, varnishes, and solvents; oil and other automotive fluids; non-hazardous liquid and
solid wastes and yard wastes; refuse, rubbish, garbage, litter, or other discarded or abandoned objects,
pesticides, herbicides, and fertilizers; hazardous substances and wastes and residues that result from
constructing a building or structure; and noxious or offensive matter of any kind.
Premises: Any building, lot, parcel of land, or portion of land whether improved or unimproved
including adjacent sidewalks and parking strips.
Standard Operating Procedures (SOPs): Established or prescribed methods to be followed routinely
for the performance of designated MS4 operations or in designated situations.
Storm Drain System: Publicly-owned facilities by which stormwater is collected and/or conveyed,
including but not limited to any roads with drainage systems, municipal streets, gutters, curbs, inlets,
piped storm drains, pumping facilities, retention and detention basins, natural and human-made or
altered drainage channels, reservoirs, and other drainage structures.
Stormwater: Any surface flow, runoff, and drainage consisting entirely of water from any form of
natural precipitation, and resulting from such precipitation.
Stormwater Pollution Prevention Plan: A document which describes the best management practices
and activities to be implemented by a person or business to identify sources of pollution or
contamination at a site and the actions to eliminate or reduce pollutant discharges to stormwater,
stormwater conveyance systems, and/or receiving waters to the maximum extent practicable.
Wastewater: Any water or other liquid, other than uncontaminated stormwater, discharged from a
facility.
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APPENDIX B
IDDE GUIDANCE
It is necessary to understand the various tracing techniques and limitations in order to select an effective
tracing technique. The following is a brief summary of each of the tracing techniques that may be used
to locate the source of an illicit discharge:
a. Visual Inspection at manholes/catch basins: This tracing technique is typically used when there is
no suspected source site. It is the most cost effective and efficient method of tracing. Structures
should be systematically inspected starting at the initial detection location, gradually working
upstream through the system. If the crew is tracking a continuous discharge, the inspections may be
relatively easy and the flow can be tracked back to its source. If the crew is attempting to track a
transitory or intermittent discharge, the crew should make the following observations depending on
the information provided from the initial identification: color and clarity of any discharges; staining
or deposits on bottom of structure; oil sheen, scum, or foam on any standing fluids in sump of
structure; odors, staining or deposits on inlet pipes and outlet pipes. Depending on what the crew is
looking for and what they find, they will progressively inspect additional structures until either a
potential source is found, or no further evidence is found. If no further evidence is found, the crew
may elect to further assess some of the structures by installing sandbags or other damming devices to
determine if the discharge recurs. Crews should use standard safety procedures when conducting
these inspections such as cone placement and safety vests in traffic areas, confined space entry
techniques (if entry is necessary), steel-toed boots, etc.
b. Sampling flowing discharges: Samples should be collected only in the event a discharge is flowing
through the outfall. Stagnant pools of water or sump water should not be sampled. If the municipal
staff will be collecting the sample, the staff should be trained in safety and proper collection
Manhole
Outfall
Storm
Initial Sampling Point
Legend:
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techniques. Table 1 lists the parameters that a sample may be analyzed for and provides a general
discussion of how the results may be interpreted.
Parameter Threshold Source
Ammonia >0.1 mg/L Brown et al (2004)
E. coli >235 CFU/100 ml (grab sample) EPA (1986)
Total coliform >10,000 CFU/100 ml (grab
sample)
California state standard (Dorfman
and Rosselot, 2011)
Fluoride >0.25 mg/L Brown et al (2004)
Detergents >0.25 mg/L Brown et al (2004)
Potassium >6 ppm Guidance extrapolated from Lilly
and Sturm (2010)
Table 1. Threshold Levels for Screening Parameters Used in Illicit Discharge Surveys
This table was taken from the CWP manual (2004) which provides a more detailed discussion of
sampling procedures and analysis of results. Sampling and analysis for many of the compounds
should be completed by personnel trained in collection, handling, and preservation techniques to
ensure accurate data. Environmental Protection Agency guidance recommends collecting a sample
when the discharge is initially found and after any source is removed. The sample collected after
removing an illicit discharge can indicate if other illicit discharges are present.
c. Sandbagging or damming: Sandbagging and damming is typically only conducted when the
discharge flow has ceased since initial detection. Application of this technique will show whether
the discharge is one time only (no water pools behind the sandbag or dam) or intermittent (water
pools behind the sandbag). CWP provides the following explanation:
1. This technique involves placement of sandbags or similar barriers such as caulk dams within
strategic manholes in the storm drain network to form a temporary dam that collects any
intermittent flows that may occur. Any flow collected behind the sandbag is then assessed
using visual observations or by indicator sampling. Sandbags are lowered on a rope through
the manhole to form a dam along the bottom of the storm drain, taking care not to fully block
the pipe (in case it rains before the sandbag is retrieved). Sandbags are typically installed at
junctions in the network to eliminate contributing branches from further consideration. If no
flow collects behind the sandbag, the upstream pipe network can be ruled out as a source of
the intermittent discharge. Sandbags are typically left in place for no more than 48 hours,
and should only be installed when dry weather is forecast. Sandbags should not be left in
place during a heavy rainstorm. They may cause a blockage in the storm drain or they may
be washed downstream and lost. The biggest downside to sandbagging and damming is that
it requires at least two trips to each manhole (CWP 2004, p. 157).
d. Optical brightener monitoring traps: Optical brightener monitoring (OBM) traps can be used to trace
intermittent or transitory discharges that result from wash water with detergent. Detergents usually
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contain optical brighteners that can be detected at high concentrations using this method. However,
the traps only detect highly concentrated discharges. The detergent concentration required to be
detected by the light is approximately the same as pure wash water from a washing machine.
Consequently, OBM traps may be best suited as a simple indicator of the presence or absence of
intermittent flow or to detect the most concentrated flows. The traps can be made using easily
acquired materials.
The traps contain an absorbent, unbleached cotton pad or fabric swatch contained inside a wire mesh
trap or section of small diameter (e.g., 2-inch) PVC pipe. The traps should be anchored to the inside
of an outfall at the invert using wire or monofilament that is secured to the pipe itself. Rocks or
bricks with holes can be used as temporary weights to hold the trap in place.
Field crews can retrieve the OBM traps after 24 to 72 hours of dry weather. OBM traps need to be
retrieved before coming into contact with stormwater, which will contaminate the trap or wash it
away. When placed under a long wave fluorescent ultraviolet or “black” light, an OBM trap will
indicate if it has been exposed to detergents. CWP reports that OBM traps have been used with
some success in Massachusetts (Sargeant et al. 1998) and northern Virginia (Waye 2000). For more
detailed guidance on how to use OBM traps and interpret the results, see the Reference section for
World Wide Web links to the studies and guidance manuals cited above.
e. Dye testing: Dye testing is typically conducted when a potential source site has been identified, and
the crew is trying to determine whether the site has floor drains or other locations that connect and
discharge to the storm drain system. Permission to access the site must be obtained before dye
testing can be conducted. Verbal or written requests are both acceptable. The crew should review
available sanitary sewer and storm drain maps before conducting the dye testing. The dye testing
procedure consists of two steps: (1) discharging the dye into the suspect location, and (2) opening
nearby storm drain and sanitary sewer manhole covers to determine where the dye discharges to.
This procedure is fairly effective for confirming direct connections into the storm drain system for
short reaches. If a longer pipe network is being evaluated, charcoal packets can be left in selected
structures and later collected and analyzed for the presence of the dye. If dye testing occurs on
porcelain structures, tablets or charcoal should be wrapped in tissue before depositing. When dye
testing, the crew should keep in mind that each structure (sink, toilet, etc.) should be tested
separately. Many times a single utility in a basement may be incorrectly connected to a storm drain
line instead of a sanitary line.
f. Televising: Televised video inspections are a useful technique when an illicit connection or
infiltration from a nearby sanitary sewer is suspected, but little evidence of the illicit discharge
remains behind. The following two types of video cameras are available for use:
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1. A small camera that can be manually pushed on a stiff cable through storm drains to observe
the interior of the piping.
2. A larger remote operated video camera on treads or wheels that can be guided through storm
drains to view the interior of the pipe. Typically the operator of the camera has access to a
keyboard or audio voice-over to record significant findings on the videotape that is produced
for future review and evaluation.
g. Smoke testing: Smoke testing is a useful technique for tracing intermittent discharges or continuous
discharges that have no apparent source site. Smoke is introduced into the storm drain system, and
emerges at locations that are connected to the system. Smoke testing works best for short reaches of
pipe, or in situations where pipe diameters are too small for video testing.
Notifying the public about the date and purpose of smoke testing before starting is critical. The
smoke used is non-toxic, but can cause respiratory irritation, which can be a problem for some
residents. Residents should be notified at least two weeks prior to testing, and should be provided the
following information (Hurco Technologies, Inc. 2003):
1. Date testing will occur
2. Reason for smoke testing
3. Precautions they can take to prevent smoke from entering their homes or businesses
4. What they need to do if smoke enters their home or business, and any health concerns
associated with the smoke
5. A number residents can call to relay any particular health concerns (e.g., chronic respiratory
problems)
Appendix C - Illicit Discharge Fact Sheet
Have you ever seen your neighbor blowing leaves or lawn clippings into the street? Have you ever witnessed any
murky water running down the ditch? What we do at home affects our local water resources, because our storm
drains and ditches are connected to nearby lakes, rivers, streams. Remember, only rain down the drain. Below
are examples of illicit discharges; if discovered, please contact the City at (763) 473-4643.
As an MS4 community, Medina regulates non-stormwater discharges to the storm drainage system. The City’s
Code 747 contains enforcement actions the City can take in the event an illicit discharge occurs.
Sources of Illicit Discharge:
• Sanitary wastewater
• Sediment from construction
site runoff
• Landscape waste
• Organic material
• Paints, solvents
• Used oil, grease
• Cleaning products
• Spills from accidents
• Illegal connections to the
storm sewer system
• Commercial car wash
wastewater
Laundry, washwater
Lawn clippings, organic material
Washwater, chemical
Petroleum, oil, solvents
Sediment from construction
Chemical release, sediment
Illegal dumping
Concrete, mortar rinse water
Outfall Inspection Form
Appendix C - Outfall Inspection Form
General Information:
Outfall ID #_____________
Inspected by: Date: ______________________
Last Rain Date (if known):_____________ Amount:____________ (inches)
Today’s Rainfall Amount: ________________________ (inches)
Address/Nearby Landmark: __________________________________________
Weather Conditions: ☐Clear Skies ☐ Overcast ☐ Other: ____________ Photos taken?
☐Yes ☐No
Outfall Data:
Outfall Type:
☐Manhole
☐Flared End
☐Swale
☐Weir
☐Flume
☐Culvert
☐Other
Outfall Condition:
☐Clear/Functioning
☐Needs Maintenance/Cleaning
☐Needs Repair
☐Needs Replacement
Immediate Action Needed? ☐Yes ☐No
Other Notes: _______________________________________________-
Discharge Data:
Visible Flow?
☐Yes ☐No ☐Submerged
Flow Depth:
____________(approx. inches)
Significant erosion and/or sedimentation?
☐Yes ☐No
If flow is present, describe and check all that apply:
☐Colored Water ________________________
☐Odor ________________________________
☐Murky, Turbid ________________________
☐Floating objects _______________________
☐Scum _______________________________
☐Oily Sheen ___________________________
☐Sludge Present ________________________
☐Clear _______________________________
☐Suds ________________________________
Illicit Discharge Details:
☐Follow-up Required Yes / No ______________
☐IDDE Source Identified Yes / No ______________
☐Responsible Party Name _______________________
☐Potential Pollutants? Yes / No ______________
☐Enforcement Response Followed Yes / No ______________
☐≥ 72 hours since last rainfall Yes / No
☐Sample Collected? Yes / No
☐Photos taken? Yes / No
☐Corrective Action Required? Yes / No
Additional Information:
Comments / Corrective Action Conducted:
Illicit Discharge Detection and Elimination Inspection Form (MCM 3)
Appendix D - Illicit Discharge Detection and Elimination
Inspection Form (MCM 3)
General Information:
Name of trained staff
conducting inspection: _________________ Inspection Date ___ / ___ / ___ Time: AM
PM
Weather:
Within Priority Area:
☐ Yes
☐ No
Photos taken?
☐ Yes
☐ No
Inspection Reason:
☐Regular Inspection
☐Complaint
☐Alleged illicit discharge
Inspection completed during dry weather condition
(period of 72 or more hours of no precipitation): ☐ Yes ☐ No
Last Rain Date:_____________ Amount:____________ (inches)
Today’s Rainfall Amount: ________________________ (inches)
Rainfall Data Source: on-site gauge weather station w/in 1 mi
Citizen Call-In Information (for citizen call-in incidents only):
Call Taken By:
__________________
Date of Call:
___ / ___ / ___
Time of Call:
______ AM/PM
Contact Information for Caller (optional):
__________________________________
Incident Location (Provide one or more below)
Lat./Long.: __________ Outfall #: _________ Closest Street Address/Landmark: ________________________
Detection and Tracking: Type of Discharge:
☐Visual inspection
☐Mobile camera
☐Sample Collected
☐Other effective investigation tool:
__________________________
☐Illegal dumping
☐Sanitary sewer
☐Cross connection
☐Floor drain
connection to storm
sewer
☐Sanitary sewer
overflow
☐Inflow / infiltration
☐Straight pipe sewer
discharge
☐Failing septic system
☐Pump station failure
☐Other: _____________
☐Inlet (City ID # _______________ ) ☐Outlet (City ID # _______________ )
Description of Discharge:
☐Flow present?
☐Estimated discharge ___________________
☐Water Color __________________________
☐Odor _______________________________
☐Turbidity ____________________________
☐Floatables ___________________________
☐Sedimentation ________________________
☐Oil Sheen ____________________________
Reporting:
Responsible Party: ____________________ (if identified) Follow-up Required? ☐Yes ☐ No
MN State Duty Officer Notified? ☐ Yes ☐ No
(1-800-422-0798)
Duty Officer Report # __________________________
Name of Staff to conduct Follow-up:
_________________________________
Corrective Actions:
Appendix E - Sec. 35-14. - Enforcement.
(a) Notice of violation. Whenever the city finds that a person has violated a prohibition or failed to
meet a requirement of this chapter, the authorized enforcement agency may order compliance
by written notice of violation to the responsible person. Such notice may require without
limitation:
(1) The performance of monitoring, analysis, and reporting.
(2) The elimination of illicit connections or discharges.
(3) That violating discharges, practices, or operations shall cease and desist.
(4) The abatement or remediation of stormwater pollution or contamination hazards and the
restoration of any affected property.
(5) Payment of a fine to cover administrative and remediation costs.
(6) The implementation of source control or treatment BMPs. If abatement of a violation
and/or restoration of affected property is required, the notice shall set forth a deadline
within which such remediation or restoration must be completed. Said notice shall further
advise that, should the violator fail to remediate or restore within the established deadline,
the work will be done by a designated governmental agency, or a contractor and the
expense thereof shall be charged to the violator.
(b) Methods of Discovery of Non-Compliance. Reports of a stormwater violation or non-compliance
may come from one the following several sources
(1) Reports from City Staff – Illicit discharges and discharges of sediment or other pollutants
from the construction sites, facilities, or other sources within the City's MS4 may be
observed by City staff as they conduct normal activities such as driving to or from job
sites or when inspecting other activities. Such non-compliances could include water and
wind erosion, sediment tracking onto local streets, poor housekeeping, incorrect
location of concrete washouts, and failed or ineffective best management practices
(BMPs).
(c) Permit Compliance Activities. Non-compliances may be discovered through Permit-required
inspections or monitoring, including construction site inspections, dry weather screening, and
stormwater sampling.
(d) Contractor Compliance Activities. A construction contractor’s failure to comply with the State’s
Construction General Permit requirements such as conducting and submitting inspection
reports, obtaining annual certifications, preparing, and implementing Stormwater Pollution
Prevention Plans (SWPPPs).
(e) Reports from the Public. Public complaints may come directly to City or through other local,
state, or federal government agencies.
(f) Construction and Post Construction Site Erosion and Sediment Enforcement. This section imposes
the obligation of an applicant to perform their duties in an honest, diligent, and cooperative
manner.
(1) Compliance Requirements
(i) Compliance with stormwater permits and laws on construction projects
within the City's MS4 must be enforced according to these Enforcement
Response Procedures.
(ii) Applicants are to comply with the State’s NPDES CGP, City, and County
permits for regulated construction projects, including the obligation to
file a NOI and obtain authorization under the State CGP for each
construction project or site. The applicant shall also file a NOT for each
construction project or site, either terminating their responsibility if
final stabilization has been achieved or transferring it to another owner
for completion.
(2) Construction Enforcement
(i) When stormwater non-compliance is identified by the City
enforcement actions will be taken promptly but no later than 7 days
following identification of the non-compliance. The City will take
appropriate sanctions against the applicant based on the nature and
severity of the situation. Non-compliances will be classified as minor or
major violation. Major violations are generally those acts or omissions
that lead to a discharge of pollutants to stormwater. Minor violations
are generally instances of non-compliance that do not directly result in
such a discharge. Serious discharges or an imminent threat of discharge
on a project may require an immediate escalation to a higher level of
enforcement. The level of enforcement response will depend upon
several of the following factors:
1. Severity of the violation: the duration, quality, and quantity of
pollutants, and effect on public safety and the environment
2. The violator’s knowledge (either negligent or intentional) of the
regulations being violated
3. A history of violations and /or enforcement actions individual or
contractor
4. The potential deterrent value of the enforcement action
(3) The City will use a progressive enforcement policy, escalating the response when an
applicant fails to respond in a timely manner. If the City identifies a deficiency in the
implementation of the approved SWPPP or amendments and the deficiency is not
corrected immediately or by a date requested by the City, the project is in non-
compliance. The timeframes to complete corrective actions and the name or position
title of responsible person(s) for conducting enforcement will be documented in the
notice.
(g) Illicit Discharges and Connection Enforcement.
(1) The Permit requires the City to implement and enforce a program that ensures that the
City effectively prohibits non-stormwater discharges into its MS4. In addition,
neighboring property owners are not allowed to occupy, use or interfere with public
ROW without permission. Any discharge/connection without permission is an illegal
encroachment on the City's MS4. A discharge/connection can be discovered in two
ways, either through routine inspection or due to a complaint.
(2) Notification of observed illicit connections or discharges will be carried forward to the
alleged illegal connector/discharger by the inspector or observer. The City will use the
following progressive enforcement policy, escalating the response when a discharger
fails to respond in a timely manner.
(h) Reporting Requirements and Documentation
(1) The City shall provide a list and description of all violations and their resolutions,
including any enforcement actions taken against contractors, corporations, or other
entities in the Annual Report to MPCA. At a minimum, the inspector should
document the source of the complaint, the date, the time, the contact person (if
any), a description of the nature of the non-compliance or illicit discharge, actions
taken, and final resolution.
(i) At a minimum, the City shall document the following for each MCM:
1. name of the person responsible for violating the terms and
conditions of the permittee's regulatory mechanism(s);
2. date(s) and location(s) of the observed violation(s);
3. description of the violation(s);
4. corrective action(s) (including completion schedule) issued by
the permittee;
5. referrals to other regulatory organizations (if any); and
6. date(s) violation(s) resolved.
(Ord. No. 653, 1-14-2008)
Appendix F - City of Medina Spill Response Plan
Emergency Contact Information
Onsite Emergency Contact(s) Steve Scherer – Primary (763) 473-8842
Lisa DeMars –Secondary (763) 473-8852
Emergency Response Contact(s) Fire/Paramedics/Police: 911
Police Non-Emergency Line: (763) 473-9209
MN Duty officer:(651) 649-5451
MN Department of Health: (651) 201-5414
National Response Center: (800) 424-8802
Spill Response Plan
Step 1: Approach the Scene
•Use safety first in responding to spills. Do not endanger yourself or others by entering a
hazardous environment. If there is a fire or medical attention is needed, call 911
immediately.
•Avoid exposure. Approach the spill from upwind and stay clear of spills, vapors, fumes
and smoke.
Step 2: Secure the Scene
•Isolate the spill.
•Keep people away from the scene; divert traffic and pedestrians as needed.
•If possible, stop the source of the spill.
•Eliminate any ignition sources.
Step 3: Identify the Hazards
•Attempt to identify the spilled material.
o Characteristics (odor, color, sheen), labels/markings, container type, activities in
the area, hazard warnings, etc.
Step 4: Assess the Situation
•Determine the appropriate first response actions and if additional response help is needed
•The response will be dictated by the size of the spill and the hazard:
o Is there a fire, a spill, or a leak?
o Is there a potential for it to mix with something else?
•Observe your surroundings:
o Who/what is at risk?
o Is an evacuation necessary?
o What resources are required and readily available to contain the spill?
Step 5: Report the Spill
• Report spills that may cause pollution, such as toxic, flammable, corrosive and dangerous
industrial chemical spills.
o Minnesota has a reporting threshold of greater than five-gallons for petroleum
spills. Spills of any quantity of all other chemicals or materials should be
reported. When in doubt, report.
• Contact the Minnesota Department of Public Safety Duty Officer at 1-800-422-0798 (toll
free) or 651-649-5451 (Metro area), if the spill of any substance or material may cause or
has caused pollution of waters of the state.
Step 6: Contain the Spill
• Always wear the appropriate personal protective equipment, such as gloves, boots, and
safety glasses. Know the limitations of the personal protective equipment.
• Place booms or available materials around the perimeter of the spill to keep it from
spreading.
o If the spill is a threat to any storm water conveyance, like street gutter, storm
drain or inlet, swale, ditch, storm, or river, place absorbent between the spill and
storm device.
• Apply absorbent materials starting from the downhill and outside edge of the spill.
Step 7: Clean Up the Spill
• If you have the proper training, small spills may be cleaned up according to the chemical
label and your training.
o Do not wash or hose down the spill into the street, ditch or storm drain.
o If flammable liquid is spilled, ventilate the area and eliminate any possible
sources of ignition.
o Clean up the spills, leaks and drips quickly. Use “dry” clean-up methods, such as
sweeping or shoveling. If the spill can be moved by wind, cover the material with
sheeting to prevent spreading.
o Place all clean-up waste in appropriate containers. If hazardous, insure that
material is placed in a hazardous waste container.
o Dispose of spill material in compliance with all Federal, State and Local
regulations.
• If you do not have proper training, or the spill is a large spill, leave the area and notify
Emergency Responders (911). Give the operator the spill location, chemical spilled and
approximate amount.
Step 8: Complete Spill Documentation and Follow-up
• Clean and decontaminate all reusable spill cleanup equipment.
• Be sure to restock your spill response materials and personal protection equipment as
soon as possible.
• Update facility spill records.
Standard Operating Procedure
1
Minimum Control Measure 4
Construction Erosion and Sediment Control
4.1 DEVELOPMENT PLAN REVIEW
Activities and Definition
Plans that are submitted to the City of Medina for approval will have a review process to verify that
erosion and sediment control standards are being met.
Maintain the following regulatory mechanism that prohibits non-stormwater discharges into the City’s
MS4 and establishes erosion, sediment, and waste controls as stringent as the Construction Stormwater
Permit requirements for construction sites:
• Ordinance
Preparation
a. When the CSW Permit is reissued, the City shall revise their regulatory mechanism(s), if necessary,
within 12 months of the issuance date of that permit, to be at least as stringent as the requirements
for erosion, sediment, and waste controls described in the CSW Permit.
b. The City shall require that owners and operators of construction activity develop site plans that must
be submitted to the City for review and confirmation that regulatory mechanism(s) requirements
have been met, prior to the start of construction activity.
c. Review City ordinances 828 – Section 29 – Construction Site Storm Water Runoff Control
Ordinance and the MPCA Construction General Permit.
d. Reviews of submitted plans, will utilize a check list to ensure accuracy.
Process
The City’s regulatory mechanism(s) shall require that owners and operators of construction activity
develop site plans that must be submitted to the City for review and confirmation that regulatory
mechanism(s) requirements have been met, prior to the start of construction activity. The regulatory
mechanism(s) shall require the owners and operators of construction activity to keep site plans up-to-
date with regard to stormwater runoff controls. The regulatory mechanism(s) must require that site plans
incorporate the following erosion, sediment, and waste controls that are at least as stringent as described
in the CSW Permit:
a. erosion prevention practices;
b. sediment control practices;
Standard Operating Procedure
2
c. dewatering and basin draining;
d. inspection and maintenance;
e. pollution prevention management measures;
f. temporary sediment basins; and
g. termination conditions.
The following processes shall be done:
a. The City of Medina shall distribute written notifications to owners and operators of the need to
apply for and obtain coverage under the CSW Permit.
b. The City shall provide a written checklist, consistent with the requirements of the regulatory
mechanisms to document the adequacy of each site.
c. Building lots will be required to submit a Stormwater Pollution Prevention Plan (SWPPP).
d. The City engineering and staff will review plans and for sites equal to or greater than one acre.
e. A check list will be used to ensure accuracy and thoroughness of submitted plans.
f. The City will be responsible for enforcement of their stormwater rules.
Follow-up
When plans are submitted by the applicant, the design staff will ensure that all comments are addressed
before work can take place on site. The applicant shall address comments offered by the City prior to
permit issuance. The City has 60 days to make a final decision on a development or redevelopment
review.
Documentation
a. Document each plan review completed within the City’s SWPPP tracking Excel table to help
expedite the annual reporting process.
1. Project name
2. Location
3. Total acreage to be disturbed
4. Owner and operator of the proposed construction activity
5. Proof of notification to obtain coverage under the CSW Permit or proof of coverage under
the CSW Permit.
6. Any stormwater related comments and supporting completed checklist, as required, will be
used by the City to determine project approval or denial
Standard Operating Procedure
3
b. Keep copies of plans, BMP quantities, and proposed BMPs that will be available to the inspector.
c. Keep a log of all maintenance agreements that are filed with the City.
4.2 TRAINING
Activities and Definition
Training of City staff will be important so that they are aware of the importance of good erosion and
sediment control practices. This includes knowledge in installation and inspection techniques as well as
record keeping and maintenance activities. It is important for City staff to be able to recognize
deficiencies in BMPs on construction sites. Inspection staff will be responsible for the tracking and
enforcing permit requirements.
The employee training provided by the City will include stormwater 101 training sessions, training
received through the University of Minnesota’s erosion and sediment control, and a hands-on process to
discuss the activities that are occurring in the field and how those activities can impact the City’s MS4
program. Including employees into the planning process will help them understand that they are part of
the solution to improve water quality.
The City shall ensure that individuals receive training commensurate with their responsibilities as they
relate to the City’s Construction Site Stormwater Runoff Control program. Individuals includes, but is
not limited to, individuals responsible for conducting site plan reviews, site inspections, and/or
enforcement. The City shall ensure that previously trained individuals attend a refresher-training every
three (3) calendar years following the initial training.
Documentation
The City of Medina shall document the training related to permit item 19.11:
1. General subject matter covered
2. Name(s) and departments of individuals in attendance
3. Date of each event
Standard Operating Procedure
4
4.3 INSPECTIONS
Activities and Definition
Construction site inspections will determine compliance with the City’s regulatory mechanism(s).
Preparation
a. Annually, identify priority sites for inspection based on topography, soil characteristics, type of
receiving water, stage of construction, compliance history, citizen complaints, or project size.
b. Ensure staff has proper training pertaining to erosion and sediment control techniques.
c. Refer to the construction site guidance document (Appendix A) and the City’s BMP standard detail
plates (Appendix B) to review proper installation techniques are being used.
Process
a. Identify sites that require an erosion and sediment control inspection.
b. Identify sites that are high-priority and low-priority sites for inspections based on the types of
receiving water(s), stage of construction, and compliance history. Ensure inspections for high-
priority and low-priority sites are done once every seven (7) days. Ensure the name(s) of
individual(s) or position title(s) responsible for conducting site inspections is the Public Works
Director.
c. Prior to construction, the following erosion and control BMPs must be installed:
1. A single rock construction entrance must be used for the entire entrance/exit of the site to
eliminate tracking into streets
2. Perimeter control:
i. Silt fence must be trenched
ii. Silt fence needed for 2:1 slopes or steeper inclines and behind sidewalk
iii. Filter logs may be used for curbside perimeter control and when slope is not an issue.
iv. Sodded buffer strip
3. Inlet Protection
4. Protection for rear lot catch basins
d. Perform inspection using the City’s construction ESC inspection form.
e. Document construction activities and follow up with site owner about findings from inspection.
Standard Operating Procedure
5
1. If feasible, prior to leaving the site talk to the responsible person to ensure corrections can be
made in a timely fashion.
2. Send the Erosion Control Notice(s) to the permit applicant responsible.
f. Perform a follow up inspection of site if deficiencies are found during initial inspection. Ensure that
correction items have been completed.
g. Failure to comply with the permit requirements may require initiating enforcement action as
described in the City’s Enforcement Response Plan as follows:
1. Verbal Warning
2. Notice of Violations
3. Stop-Work Orders
Documentation
a. The City of Medina shall maintain written procedures for identifying high-priority and low-priority
sites for inspection. At a minimum, the written procedures shall include:
1. Detailed explanation describing how sites will be categorized as either high-priority or low-
priority;
2. A frequency at which the City will conduct inspections for high-priority sites;
3. A frequency at which the City will conduct inspections for low-priority sites; and
4. The name(s) of individual(s) or position title(s) responsible for conducting site inspections
b. City staff shall record the following items in the City’s SWPPP tracking system to document each
site inspection when determining compliance with the City’s regulatory mechanism(s).
1. Stabilization of exposed soils (including stockpiles)
2. Stabilization of ditch and swale bottoms
3. Sediment control BMPs on all downgradient perimeters of the project and upgradient of
buffer zones
4. Storm drain inlet protection
5. Energy dissipation at pipe outlets
6. Vehicle tracking BMPs
7. Preservation of a 50-foot natural buffer or redundant sediment controls where stormwater
flows to a surface water within 50 feet of disturbed soils
8. Containment for all liquid and solid wastes generated by washout operations (e.g., concrete,
stucco, paint, form release oils, curing compounds, and other construction materials)
9. BMPs maintained and functional
Standard Operating Procedure
6
c. City staff shall record the following items in the City’s SWPPP tracking system to document the
status of erosion and sediment control violations, enforcement actions and follow-up:
1. Keep logs of number of inspections.
2. Keep records of inspection reports and reports sent.
3. Keep records of escalation of penalties.
a. Name of the person responsible for violating the terms and conditions of the City’s
regulatory mechanism(s)
b. Date(s) and location(s) of the observed violation(s)
c. Description of the violation(s)
d. Corrective action(s) (including completion schedule) that the City issued
e. Referrals to other regulatory organizations (if any)
f. Date(s) violation(s) resolved
d. Save all documents within the City’s network designated SWPPP folder using the same folder
structure as provided with the electronic SWPPP provided.
Noncompliance
The City of Medina shall maintain written procedures for receipt and consideration of reports of
noncompliance or other stormwater related information on construction activity submitted by the public.
a. The public may submit concerns about construction violations through the City’s
website or by calling the City directly. Reports are investigated within one business
day.
The City shall implement and enforce a regulatory mechanism(s) that establishes requirements for
erosion, sediment, and waste controls that is at least as stringent as the Agency's most current
Construction Stormwater General Permit (MNR100001).
Standard Operating Procedure
7
4.5 CITY PROJECTS EROSION AND SEDIMENT CONTROL BMPS
Activities and Definition
City projects that involve excavation or filling, or a combination of excavation and filling, in excess of
50 cubic yards of material will use proper erosion and sediment control BMPs.
Preparation
a. Provide BMPs for City projects including inlet protection, perimeter control, temporary and
permanent stabilization methods.
b. Ensure staff has University of Minnesota’s erosion and sediment control certification and/or have
been trained by a certified staff person on proper erosion and sediment control techniques.
c. Refer to the construction site guidance document (Appendix A) and the City’s BMP standard detail
plates (Appendix B) to review proper installation techniques are being used.
Process
a. All qualified construction and land disturbing activities within the City should follow the City Code
as well as the City’s Engineering Design Standards for Stormwater Management.
b. All construction projects that have the potential to impact the MS4 system or any natural resource
will have BMPs available prior to construction activity.
c. All perimeter control BMPs are required to be fixed, substituted, or enhanced if they are no longer
working or sediment fills one-half (1/2) of the height of the BMP. This must be done by the end of
the next business day or as soon as site conditions permit.
d. Temporary or permanent sediment basins are required to be drawn down and have sediment
removed when the depth of the captured sediment reaches one-half (1/2) the storage volume of the
basin.
e. Tracked sediment from the construction site entrance/exit is required to be removed from all paved
surfaces both on and off site. This must be done as soon as possible or within 24 hours of being
found.
f. Install down gradient perimeter control where needed on the site.
g. Provide inlet protection for adjacent inlets and outlets, to prevent sediment and debris from
discharging into the storm sewer.
Standard Operating Procedure
8
h. Stabilize all exposed soil areas and stockpiles as soon as possible or upon completion of work. If
work is not complete, temporary stabilization methods will be used if the work will not continue for
more than 14 days, or 7 days depending on the discharge proximity to special/impaired waters.
i. If any sediment reaches the MS4 system (including surface waters, drainage ditches, and conveyance
systems, etc.), the sediment is required to be removed within seven (7) days after it is found.
Documentation
a. Keep a log showing that BMPs were inspected and properly maintained during the active
construction period until the period where final stabilization has been achieved.
b. Sites should be inspected weekly or after a rainfall event greater than 0.5 inches in 24 hours where
the soil disturbance is 1 acre or greater in accordance with the NPDES Construction General Permit.
c. Document maintenance performed on:
1. Perimeter Control
2. Inlet Protection
3. Erosion Control BMPs
4. Stabilization Performed
5. Sediment Control BMPs
d. If applicable, record the amount of waste collected, the number of catch basins cleaned, and the area
they were cleaned in. Keep any notes or comments of any problems.
e. If applicable, document the final location of where the material was disposed, and any paperwork
received from the disposal location.
f. Save all documents within the City’s network designated SWPPP folder using the same folder
structure as provided with the electronic SWPPP provided.
Standard Operating Procedure
9
4.6 PRIVATE PROJECTS
Activities and Definition
a. Private projects that require a permit, as per the requirements set forth in the City Code will use
proper erosion and sediment control BMPs. Depending on the proposed improvements, these sites
may also be required to install BMPs for post-construction stormwater management. Building
officials will be responsible for inspecting building permit activities. Engineering staff will be
responsible for inspecting sites that require a state NPDES permit.
b. The City requires the submittal of a Stormwater Management Plan for all projects that require a
grading, drainage and erosion control permit.
c. The City has staff that actively inspects construction sites throughout the City’s jurisdiction.
Process
a. All qualified construction and land disturbing activities within the City should follow the City Code
and the City’s Engineering Design Standards for Stormwater Management.
b. Any private projects that are within the City limits will be inspected by a qualified City employee.
Inspections will occur at a frequency that is commensurate of the activities taking place. The field
inspector will use the City’s ESC inspection form.
Documentation
a. Keep track of private project locations and obtain contact information for owners and operators on
file at the City.
b. Keep records of long-term maintenance agreements on file at the City.
c. Keep records of inspection reports and reports sent.
d. Keep records of any enforcement action(s) taken.
The City of Medina shall conduct an annual assessment of the Construction Site Stormwater Runoff
Control program to evaluate program compliance, the status of achieving the measurable requirements
(activities that must be documented or tracked as applicable to the MCM (e.g., inventory, trainings, site
plan reviews, inspections, enforcement, etc.)) in Section 19 of the MS4 General Permit and determine
how the program might be improved. The City shall perform the annual assessment prior to completion
of each annual report and document any modifications made to the program because of the annual
assessment.
Appendix A - City of Medina
Site Plan Review Checklist
Submittals Received
Date Document Author
General Site Plan
Yes No
Scale of Survey. Minimum scale 1” = 50’. Maximum size plan sheet 24” x 36”
Survey signed by a registered survey with elevations in NGVD -1929 datum for the following
locations:
Each lot corner
Grade elevation at the foundation and elevation of top of foundation of structures on
adjacent lots
Grade elevation at the foundation, elevation of top of foundation and garage flo or of
proposed new construction
Lowest point of entry (i.e. door sill or top of window well) of pro posed and existing
construction
Lowest floor of proposed and existing construction
Any proposed retaining wall must have a top and bottom elevation and bottom elevation would be
finish grade. Also, no retaining wall is allowed to be built on private property
Retaining walls greater than 4.0 feet in height have been designed and certi fied by a licensed
professional engineer and a building permit has been acquired
Easements are clear of any encroachments?
New curb cuts proposed? If new curb cut is proposed, stamp all survey maps with the curb cut
stamp. Also, write a note on the Residential Plan & Routing Approval form reminding the builder
that a curb cut permit is required if the driveway is moved or a new driveway is added
Low floor a minimum of 4.25’ (feet) above the sanitary sewer invert elevation
Comments:
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
Address: Permit No:
PID: Date Approved:
Date Received: Signature:
Site Size (acres):
Area of
Disturbance(acres):
Existing
Impervious (acres):
Proposed
Impervious (acres):
Erosion Control Plan
Yes No
SWPPP notes provided on the plan
Temporary stabilization measures provided
Erosion control blankets provided on all slopes greater than 3:1
Perimeter Control i.e., Silt Fence, Filter Log, etc.
Phasing for sites that are ≥ 1 acre
CB Inlet Protection
Dewatering
Sediment control
Waste control
Concrete washout
Rock entrance
Street sweeping schedule
Permanent restoration plan
SWPPP includes an erosion and sediment control inspection schedule and person responsible for
maintenance
Comments:
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
Stormwater Management Plan
Yes No
Delineation map
Modeling calculations for existing and proposed conditions
2, 10, 100, Snowmelt
Modeled direct connected impervious separate
Off-site drainage included
Wetlands shown on plans and wetland permitting completed
Pretreatment
Skimmer structures provided on the outlets of all ponds.
Soil borings
Design Infiltration Rate Determination
Seasonal High Water Elevation
Comments:
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
Water Quality
Yes No
Volume control provided as per the Watershed Management Commission
Sequencing provided for alternatives where infiltration is infeasible
Required Water Quality Volume:
Provided Water Quality Volume:
Comments:
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
Rate Control
Yes No
Peak Discharge Rates < Existing
Comments:
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
Freeboard
Yes No
Building Opening:
3’ above the critical 100-yr HWL of local basins, wetlands, & infiltration basins
2’ above EOF of local basins, wetlands, & infiltration basins
2’ above the 100-yr flow elevation of a swale or channel at the point where the swale
channel is closest to the building
Low Floor Elevation:
2’ above the critical 100-yr HWL of major basins
2’ above EOF of major basins
For landlocked basins: 2’ above the HWL from back to back 100-yr rainfalls or 2’ above
the HWL from the 100-yr 10-day snowmelt, whichever is higher. Starting elevation of
the basin/waterbody prior to runoff is one of the following:
o Existing Ordinary High Water level established by the Minnesota Department of
Natural Resources
o Annual water balance calculation approved by the City
o Local observation well records, as approved by the City
o Mottled soil
Comments:
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
Appendix B - Construction Site Stormwater Runoff ESC Inspection Form
Site Name: Permit No.: Inspector(s):
Address: Inspection Date: ____ / ____ / ____
Time: __________ am/pm Photos Taken? ☐Yes ☐No
Owner: Weather: Date of Last Inspection: ____ / ____ / ____
Contractor: Priority Area: ☐Yes ☐No Last Rain Date: ____ / ____ / ____
Amount: ________(inches)
Inspection Reason:
☐Routine ☐Complaint ☐Spot-Check
Today’s Rainfall
Amount : _______(inches)
Rainfall Data Source :
☐On-site Gauge ☐Weather Station w/in 1 mile
BMP Compliant? Maintenance
Required? Corrective Action(s) Needed & Notes Date Corrected
1. Perimeter controls installed/maintained? ☐Yes
☐No
☐Yes
☐No
2. Natural features are protected with a BMP? ☐Yes
☐No
☐Yes
☐No
3. Storm drain inlets are properly protected? ☐Yes
☐No
☐Yes
☐No
4. Stockpiles protected and not placed in a conveyance? ☐Yes
☐No
☐Yes
☐No
5. Construction entrance prevents tracking? ☐Yes
☐No
☐Yes
☐No
6. Trash/litter collected and contained? ☐Yes
☐No
☐Yes
☐No
7. Non-active disturbed areas are stabilized? ☐Yes
☐No
☐Yes
☐No
8. Discharge points are free of sediment deposits? ☐Yes
☐No
☐Yes
☐No
9. Washout facilities are available/used? ☐Yes
☐No
☐Yes
☐No
10. Vehicle fueling areas are free of leaks and spills? ☐Yes
☐No
☐Yes
☐No
11. Potential contaminants are protected? ☐Yes
☐No
☐Yes
☐No
BMP Compliant? Maintenance
Required? Corrective Action(s) Needed & Notes Date Corrected
12. Any evidence of discharges? ☐Yes
☐No
☐Yes
☐No
13. Portable toilets are upright and secure? ☐Yes
☐No
☐Yes
☐No
15
Dewatering activities are using appropriate BMPs to
avoid scour and selected chemicals are suited to soil
types?
☐Yes
☐No
☐Yes
☐No
16. SWPPP on site? ☐Yes
☐No
☐Yes
☐No
17. Inspection reports available? ☐Yes
☐No
☐Yes
☐No
18. Training documentation is available? ☐Yes
☐No
☐Yes
☐No
19. Other: ☐Yes
☐No
☐Yes
☐No
20. Other: ☐Yes
☐No
☐Yes
☐No
Additional Comments:
Standard Operating Procedure
APPENDIX C
EROSION AND SEDIMENT CONTROL REMINDER HANDOUT
• Erosion and sediment control measures for single-family residential construction must be in place
before any clearing and grading is performed.
• Erosion and sediment control measures must be installed to City of Medina’s standards. These
requirements are in the engineering guidelines attached to your permit package. Additional site-
specific erosion control measures may be necessary for your project. Winter site stabilization
controls for erosion and sedimentation are in effect from October 1st to April 30th.
• Erosion and sediment control measures are monitored by City environmental resources staff during
the construction process. These inspections are covered by a flat fee. Hourly fees for erosion and
sediment control inspections only will be assessed if more than 0.25 hours of inspection time is
required. This billing system offers customers predictability with regard to assessed fees, and also
rewards customers who properly manage erosion and sediment control measures on their
construction sites.
• If erosion and sediment control measures are in need of repair, a correction notice will be issued. If
corrections are not made and/or if sediment is leaving your project, a Stop Work order may also be
issued.
• Stop Work orders and code enforcement inspections will be billed at the hourly rate.
• Foundation inspection approval will not be granted until erosion and sediment control measures are
in place.
• Minor corrections to erosion and sediment control measures that are in place must be completed in
the timeframes outlined in NPDES permit requirements. If corrections are not completed within that
timeframe, a Stop Work order will be posted and code enforcement fees will be charged.
• Sites must be vegetated either temporarily or permanently with appropriate sediment controls prior
to being transferred to the homeowner. Failure to complete this task will result in the City executing
the security and completing the necessary activities to provide stabilization of the site.
• Homeonwer’s must receive the MPCA “Homeowner” fact sheet that describes the importance of
maintaining erosion and sediment control until final stabilization is achieved.
• Please contact your building inspector or call (763) 479-1720 if you have any erosion and sediment
control questions.
Individual Lot Erosion and Sediment Control
Appendix D rear yard. rotect1on� ;n����STM-:
�-- - - -
.----.---- .----.----
)
l
l )
l
l t )
) + ) -curb inlet protection LV-STM-12 street
- -- -..... --- ··_x· .. ..
·_· ___ ·%-
-
-----
-
---------
_·· ·(.) _. _ _._ .-. .. . ·. c-.
· . . ·. -� . . -_.._M·· :. ----------�--�------
-Q)_ )=-.. :. ::-::}!:<:"
-.. �--:. _._
. .. -�. -_ ..... --
-··_ ·-1/1
--_. _ _._
-------------::�---:----_. _ _._
)
) L
) l )
) l
sidewalk
'existing curb and gutter
Erosion Control Legend
•--direction of drainage ..,.._ finished grade ♦I� silt fenceI I 0 stockpile I I I (\ temporary/permanent cover
♦ Notes I 1. It is the responsibility of the builder I to comply with State laws and local
I ordinances regarding construction site erosion and sediment control.
•2. This plan is only a sample planand is not intended to be all inclusive I or address every situation, additional
I or modified practices may be required.
I 3. Erosion and sediment control measures must be functional and maintained throughout construction. I
I 4. Maintain positive drainage away
I from the structure(s).
T 5. Streets must be cleared of all debris at the end of each day.
I 6. Temporary/permanent cover is I required on all exposed soils through
I out the building process.
T 7.Stockpiles must not be placed nearwaterbodies or on streets or sidewalks.
Appendix E - Construction ESC Winter Inspection
Form
Date & Time of Inspection:
Weather Conditions:
Reason for Inspection:
24 Hour Precipitation: in.
Project Name: Project Number
NPDES Permit #: Owner/Permittee:
MN State Duty Officer: Contractor/Permittee:
Site Contact 1: Site Contact 2:
In attendance:
General Site Activities:
Inspection Findings: Compliant, Deficient, Non-Compliant, N/A
1. Exit BMPs/Adjacent Roadway
(sweeping)
2. Construction Phasing
3. Buffer Zones 4. Concrete Washout
5. Dewatering/Bypass Pumping 6. Polymer/Flocculent Application
7. Ditch Checks 8. Grading/Earthwork
9. Dust Control/ Wind Erosion 10. Inlet Protection (in
place/removed for safety)
11. ESC BMP Maintenance 12. Outlet Control Structure (24
hrs.)
13. Inclement Weather Ready
(melting/runoff)
14. Perimeter Sediment Controls
15. Redundant Perimeter Controls 16. Turbidity Curtain/Fence
17. Soil Stockpile Protection &
Stabilization
18. SWPPP Amendments
19. Offsite Discharges 20. Stabilization Measures/24 Hour
21. Secondary/Hazard Containment 22. Stabilization Measures/7 Day
23. Waste/Trash Containment 24. Stabilization Measures/14 Day
25. Snow Coverage % 26. Inspection Records & SWPPP
Documentation
Items that need maintenance:
Status:
Correct By:
Location:
Details:
Status:
Correct By:
Location:
Details:
Status:
Correct By:
Location:
Details:
Status:
Correct By:
Location:
Details:
Status:
Correct By:
Location:
Details:
Inspector
Signature:
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wq-strm2-36 • 9/12/18 Page 1 of 4
Appendix F
Construction Stormwater
Inspection Checklist
Construction Stormwater Program
Doc Type: Permitting Checklist
Note: This inspection checklist is an option for small construction sites. Large construction sites and linear projects
require more extensive/more location specific inspection requirements. This inspection report does not address all aspects of
the National Pollutant Discharge Elimination System/State Disposal System (NPDES/SDS) Construction Stormwater Permit (Permit)
issued on August 1, 2018. The completion of this checklist does not guarantee that all permit requirements are in compliance; it is
the responsibility of the Permittee(s) to read and understand the permit requirements.
Facility information
Site name:
Site address: Permit number:
City: State: Zip code:
Inspection information
Inspector name: Phone number:
Organization/Company name:
Date (mm/dd/yyyy): Time: ☐ am ☐ pm
Is the inspector trained in sediment and erosion control and is it documented in the Stormwater Pollution Prevention Plan (SWPPP)?
☐Yes ☐ No
Is this inspection routine or in response to a storm event: ☐ 7 day ☐ Rain
Rainfall amount (if applicable):
Is site within one aerial mile of special or impaired water that can potentially receive discharge from the site? ☐ Yes ☐ No
If yes, follow Section 23 and other applicable permit requirements.
Note: If NA is selected at any time, specify why in the comment area for that section.
Erosion prevention requirements (Section 8.1)
Yes No NA
1.Are soils stabilized where no construction activity has occurred for 14 days (including
stockpiles)? (7 days where applicable, or 24 hours during Minnesota Department of Natural
Resources [DNR] Fish Spawning restrictions)☐ ☐ ☐
2.Has the need to disturb steep slopes been minimized?☐ ☐ ☐
3.If steep slopes are disturbed, are stabilization practices designed for steep slopes used?☐ ☐ ☐
4.All ditches/swales stabilized 200’ back from point of discharge or property edge within 24
hours? (Mulch, hydromulch, tackifier, or similar best management practices [BMPs] are not
acceptable in ditches/swales if the slope is greater than 2%)☐ ☐ ☐
5.Do pipe outlets have energy dissipation (within 24 hours of connection)?☐ ☐ ☐
6.Is construction phasing being followed in accordance with the SWPPP?☐ ☐ ☐
7.Are areas not to be disturbed marked off (flags, signs, etc.)?☐ ☐ ☐
Comments:
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Sediment control requirements (Section 9.1))
Yes No NA
1. Are perimeter sediment controls installed properly on all down gradient perimeters? ☐ ☐ ☐
2. Are appropriate BMPs installed protecting inlets, catch basins, and culvert inlets? ☐ ☐ ☐
3. Is a 50 foot natural buffer preserved around all surface waters during construction? ☐ ☐ ☐
If No, have redundant sediment controls been installed? ☐ ☐ ☐
4. Do all erodible stockpiles have perimeter control in place? ☐ ☐ ☐
5. Is there a temporary sediment basin on site, and is it built as required in Section 14 of the
permit? ☐ ☐ ☐
6. Is soil compaction being minimized where not designed for compaction? ☐ ☐ ☐
7. Is topsoil being preserved unless infeasible? ☐ ☐ ☐
8. If chemical flocculants are used, is there a chemical flocculant plan in place? ☐ ☐ ☐
Comments:
Maintenance and inspections (Section 11)
Yes No NA
1. Are all previously stabilized areas maintaining ground cover? ☐ ☐ ☐
2. Are perimeter controls maintained and functioning properly, sediment removed when one-
half full? ☐ ☐ ☐
3. Are inlet protection devices maintained and adequately protecting inlets? ☐ ☐ ☐
4. Are the temporary sediment basins being maintained and functioning properly? ☐ ☐ ☐
5. Are vehicle tracking BMPs at site exists in place and maintained and functioning properly? ☐ ☐ ☐
6. Is all tracked sediment being removed within 24 hours? ☐ ☐ ☐
7. Have all surface waters, ditches, conveyances, and discharge points been inspected? ☐ ☐
8. Were any discharges seen during this inspection (i.e., sediment, turbid water, or otherwise)? ☐ ☐
If yes, record the location of all points of discharge. Photograph and describe the discharge (size, color, odor, foam, oil
sheen, time, etc.). Describe how the discharge will be addressed. Was the discharge a sediment delta? If yes, will the delta
be recovered within seven days and in accordance with item 11.5 of the permit?
Comments:
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Pollution prevention (Section 12)
Yes No NA
1. Are all construction materials that can leach pollutants under cover or protected? ☐ ☐ ☐
2. Are hazardous materials being properly stored? ☐ ☐ ☐
3. Are appropriate BMPs being used to prevent discharges associated with fueling and
maintenance of equipment or vehicles? ☐ ☐ ☐
4. Are all solid wastes being properly contained and disposed of? ☐ ☐ ☐
5. Is there a concrete/other material washout area on site and is it being used? ☐ ☐ ☐
6. Is the concrete washout area marked with a sign? ☐ ☐ ☐
7. Are the concrete/other material washout areas properly maintained? ☐ ☐ ☐
Comments:
Other
Yes No NA
1. Is a copy of the SWPPP, inspection records, and training documentation located on the
construction site, or can it be made available within 72 hours? ☐ ☐ ☐
2. Has the SWPPP been followed and implemented on site, and amended as needed? ☐ ☐ ☐
3. Is any dewatering occurring on site? ☐ ☐ ☐
If yes, what BMPs are being used to ensure that clean water is leaving the site and the
discharge is not causing erosion or scour?
4. Will a permanent stormwater management system be created for this project if required
and in accordance with Section 15 of the permit (if adding an acre or more of new
impervious surface)? ☐ ☐ ☐
If yes, describe:
5. If infiltration/filtration systems are being constructed, are they marked and protected
from compaction and sedimentation? ☐ ☐ ☐
6. Description of areas of non-compliance noted during the inspection, required corrective actions, and recommended date of
completion of corrective actions:
7. Proposed amendments to the SWPPP:
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8. Potential areas of future concern:
9. Additional comments:
Disclosures:
• After discovery, the permit requires many of the deficiencies that may be found on site be corrected within a specified
period of time. See permit for more details.
• The Permittee(s) is/are responsible for the inspection and maintenance of temporary and permanent water quality
management BMPs as well as erosion prevention and sediment control BMPs until another Permittee has obtained
coverage under this Permit according to Section 3, or the project has met the termination conditions of the permit and a
Notice of Termination has been submitted to the Minnesota Pollution Control Agency.
Appendix G - Stormwater
Construction Inspection
Guide
October 2018
Acknowledgments
This guidance was developed under EPA Contract GS-10F-0268K, Task
Order 1100 managed by Irvin J. Dzikowski, EPA Region V. The Minnesota
Pollution Control Agency contract manager was Joyce Cieluch. The
valuable assistance of Michael Findorff, Ken Moon, Reed Larson,
and others from the MPCA in developing this guidance is gratefully
acknowledged. Tetra Tech, Inc. drafted the guidance with John Kosco
serving as project manager and primary author.
Comments welcome
This is the first edition of the Inspection Guide. We welcome comments
and suggestions on how it might be changed in future editions to better
assist stormwater inspectors. Send comments to:
Logan Quiggle, MPCA Stormwater Engineering, Outreach, and Research
520 Lafayette Rd., St. Paul, MN 55155
Logan.Quiggle@state.mn.us
wq-strm2-10
Table of Contents
Introduction...................................................................................1
Purpose of this inspection guide ...............................................1
Construction Stormwater Permit Overview ............................1
Changes in owner/operator .......................................................2
How to conduct a stormwater inspection.................................3
Construction Site Inspector: Role and responsibilities .........3
Inspection procedures .................................................................4
Report writing and follow-up ..................................................11
Tips on inspecting BMPs............................................................13
Inspecting BMPs..........................................................................13
Referring enforcement cases to the MPCA ............................22
Additional resources...................................................................24
Definitions.....................................................................................25
Attachment A - Photo log......................................................... 28
Attachment B - Violation citations ......................................... 29
Attachment B - Violation citations (continued).................... 31
Attachment C - Temporary, permanent sediment basin checklist......................................32
Stormwater Construction Inspection Guide 1
Purpose of this inspection guide
This stormwater construction inspection guide is designed to assist construction site
inspectors, such as staff representing various local units of government, in the procedures
for conducting a compliance inspection at construction sites. The focus of this guide is on
inspecting construction sites less than five disturbed acres; however, the principles of this
inspection guide can be applied to construction sites of any size.
After a brief overview of the Minnesota Pollution Control Agency (MPCA) construction
stormwater permit, this inspection guide covers three main topics: How to conduct
a stormwater inspection, tips on inspecting BMPs, and information about referring
enforcement cases to the MPCA.
Construction Stormwater Permit Overview
The MPCA issued the National Pollutant Discharge Elimination System/State Disposal
System (NPDES/SDS) General Stormwater Permit for Construction Activity in August
2018. Owners and operators of construction
activity disturbing one acre or more of land need
to obtain the construction stormwater permit.
Sites disturbing less than one acre within a larger
common plan of development or sale that is more
than one acre also need permit coverage.
Regulated parties are required to develop a
stormwater pollution prevention plan (SWPPP)
and submit a completed application and a $400
application fee. Application must be completed
on-line by creating an e-Services account. Access
the e-Services webpage by visiting https://
rsp.pca.state.mn.us/TEMPO_RSP/Orchestrate.
do?initiate=true.
What is a “larger common plan of development or
sale?”
A common plan of development or sale means a contiguous
area where multiple separate and distinct construction activities
are occurring under one overall plan (e.g., the operator is
building on three half-acre lots in a six-acre development). The
“plan” in a common plan of development or sale is broadly
defined as any announcement or documentation or physical
demarcation indicating that construction activities may occur
on a specific plot.
1Chapter
Introduction
2 Stormwater Construction Inspection Guide
In addition to developing the SWPPP, regulated parties must implement the SWPPP,
conduct regular inspections, and maintain best management practices (BMPs).
Inspections are required once every seven days during active construction and within 24
hours after a rainfall event greater than 0.5 inches in 24 hours.
The next inspection must be conducted within
seven days after that. At the end of the project, after
all disturbed surfaces are stabilized, the regulated
party must submit a notice of termination/permit
modification form to let the MPCA know that the
construction activity is complete.
For most sites, construction may begin upon
completing the payment process. For sites that are
more than 50 acres and discharging to a special or
impaired waters, the SWPPP and application materials
must be submitted at least
30 days prior to commencing construction.
Changes in owner/operator
When the owner or operator or a portion of a site or
entire site changes, the former owner or operator and
the new owner or operator needs to submit a Notice
of Termination (NOT) / Permit Modification to the
MPCA. The form is available on the MPCA construction stormwater website and must be
submitted within seven days of assuming operational control of the site, commencing
work on their portion of the site, or of the legal transfer, sale or closing on the property.
For stormwater discharges from construction activities where the owner or operator
changes, the new owner or operator can implement the original SWPPP created for the
project or develop and implement their own SWPPP. Permittee(s) shall ensure either
directly or through coordination with other permittee(s) that their SWPPP meets all
terms and conditions of the permit and that their activities do not render another party’s
erosion prevention and sediment control BMPs ineffective.
Additional information on the MPCA’s Stormwater Program is available on the web at
www.pca.state.mn.us/water/stormwater.
What are “special waters?”
Additional requirements apply to construction sites that
discharge within one-mile of a special water. These waters can
include:
• Wilderness areas (such as the Boundary Waters Canoe
Area Wilderness, Voyageurs National Park, and parts of
Kettle River and Rum River)
• Mississippi River (portions of)
• Scenic or recreational river segments (such as the Saint
Croix River and Cannon River)
• Lake Superior
• Lake Trout lakes
• Trout lakes
• Scientific and natural areas
• Trout streams
(See Section 23 of the construction stormwater permit for more
information or use the Special Waters Search tool on the MPCA
construction stormwater webpage).
Stormwater Construction Inspection Guide 3
Construction Site Inspector: Role and
responsibilities
The inspector determines compliance with permit conditions, applicable regulations, and
other requirements and assesses the adequacy of best management practices to protect
natural resources. This is primarily accomplished by reviewing on-site activities for permit
compliance and the construction operator’s SWPPP.
Legal responsibilities
Item 24.10 of the construction stormwater permit provides inspectors the authority to
inspect construction sites. This section of the permit requires the construction operator
to “allow representatives of the MPCA or any member, employee or agent thereof, when
authorized by it, upon presentation of credentials, to enter upon any property, public or
private, for the purpose of obtaining information or examination of records or conducting
surveys or investigations.” An inspector’s first responsibility is to be familiar with the
specific requirements in the general permit, and applicable regulations. Inspectors must
always have and display their inspection credentials.
Professional responsibilities
Inspectors are expected to perform their duties with a high degree of professionalism.
Facts are to be noted and reported completely, accurately and objectively. Inspectors
should also be tactful, courteous and diplomatic when working with construction
operators and other members of the public. During an inspection, inspectors should not
speak derogatorily of any product, manufacturer or person.
When problems are found that are not significant, inspectors should provide technical
assistance on approaches for dealing with minor issues that do not warrant a violation
notice. This could include minor issues that, if not corrected, could lead to a violation.
Technical assistance refers to providing general guidance on how to solve erosion and
sediment control problems without providing specific design details. In other words, the
inspector does not provide engineering advice.
2Chapter
How to conduct a
stormwater inspection
4 Stormwater Construction Inspection Guide
Inspection procedures
An on-site construction site inspection will typically consist of the following components,
followed by the development of an inspection report:
• Pre-Inspection Preparation
• Entry
• Records Review
• Site Inspection
• Exit Interview
Pre-inspection preparation
Plan your inspections by targeting construction sites in priority areas (i.e., sites
discharging to special waters, sites near surface waters, areas undergoing rapid
development), large construction sites, or sites with a history of compliance problems. Be
flexible, and plan your inspections immediately prior to or during anticipated rain events,
or immediately following actual rain events (this is the best time to conduct stormwater
inspections!). Identify more inspection candidate sites than you can visit in a day so you
have back-up sites in case changes occur.
In preparing for an inspection, also review available
files such as permits, copies of SWPPPs or erosion
and sediment control plans, past inspection
reports, downstream water quality problems
from monitoring/assessment reports, and other
correspondence such as maintenance records on
the construction sites you will be inspecting. Copy
relevant information that may be useful in the field.
This could include past inspection reports in order
to verify that problems have been corrected. Use
the special waters search on the MPCA website to
determine whether any of the construction sites you plan to visit are located near special
waters or impaired waters. Discharges to special waters, wetlands, and impaired waters
have additional requirements that are described in Section 23 of the permit.
Find all the construction sites you’ll be inspecting on a map to plan out your day. Group
inspections by geographic area when possible to minimize your drive time.
Finally, be prepared for the inspection. Dress for the weather and take appropriate safety
gear. Make sure you have the following: inspection credentials, digital camera, copies
of inspection forms, copy of the general permit, logbook for taking notes, and personal
protective equipment (steel-toed shoes, hard hat, safety vest). Always take extra copies of
materials such as the general permit, inspection forms, and application forms.
Always keep safety in mind!
• Use safety equipment such as hard hats, reflective vests,
and steel-toed shoes.
• Maintain safety equipment in good condition and proper
working order.
• Watch where you are walking, and be careful of what is
going on overhead.
• Never enter confined spaces, such as a ditch or manhole,
unless properly trained, equipped, and certified.
Stormwater Construction Inspection Guide 5
Entry
Before entering the construction site, observe the
surroundings and various stages of construction. Note
areas for in-depth review and any clear violations. This
is also a good time to view construction site vehicle
exit locations and perimeter controls. Indicate on the
inspection form the date/time and weather conditions
(e.g., light rain, sunny, some rain in previous 24 hours).
When entering the site, review all postings and then ask for the owner or contractor
whose name is on the application. If these people are not available, ask to speak with
someone who is familiar with the construction site’s SWPPP. Always note the names of
the individuals with whom you meet. Present your credentials and explain the purpose of
your inspection. Inform the individual of the typical sequence of events for the inspection
(introductions, file review, site tour, exit interview, report preparation, delivery and
follow-up). Ensure that the construction operator participates during the records review
and accompanies you during the inspection. Ask if there are any specific safety issues or
requirements for this site.
Records review
Ask to see a copy of their SWPPP and application
for coverage under the general stormwater permit,
including a copy of all construction site inspections
(i.e. the weekly inspections owners/operators are
required to make weekly as well as within 24 hours
of a rain event greater than 0.5 inches in a 24-hour
period).
Review the SWPPP to ensure it addresses all the
requirements in the permit. Specific items in the
SWPPP to review and record in your notes include:
• The most recent date of the SWPPP, and who
prepared it.
• Primary erosion prevention and sediment control BMPs used on-site.
• Inspection and maintenance records, which are required to be kept with the
SWPPP. Operator is required to inspect the site once every seven days and within
24 hours after a rainfall event greater than 0.5 inches in 24 hours.
• Permanent stormwater management practices.
• Pollution prevention practices (especially for fueling, solid waste, hazardous
materials, and vehicle washing).
• Discharge points from the project to surface waters and wetlands.
What if the site does not have a permit?
If a construction site disturbing more than one-acre has not
applied for the stormwater permit, notify your Regional MPCA
construction contact. Explain to the site representative the
requirement to apply for a stormwater permit, continue the
inspection, and leave compliance assistance materials such as
a copy of the permit and application. Note the violation on the
inspection form.
What to do if denied entry?
Stay calm and explain that the permit provides the MPCA
and MPCA representatives with the authority to conduct
inspections. Inquire as to why you are denied entry and record
this information in your notes. Explain that you will need this
information so that you can accurately portray their reasons for
denial to your supervisor. Evaluate what they said were their
reasons and determine if there are ways you can mitigate their
concerns. Many times their concerns are unfounded. In no case
should you threaten or indicate that their denial may lead to
future punitive penalties.
6 Stormwater Construction Inspection Guide
Include in your notes a general narrative of the construction activity (e.g., construction of five single
family homes on 2.5 acre parcel). Ask the construction operator to describe the project as you review the
SWPPP. Questions you can ask include:
• How large is the project, how long has construction been underway, and when do you plan to
complete construction?
• Do you store or use hazardous materials or waste fluids on-site? Do you refuel vehicles or
equipment on-site?
• Does this project include concrete pouring, and how do you handle washout of concrete trucks?
• Does the project have a rain gage, and how do you track rainfall amounts?
• What procedures do you institute in advance of forecasted rain events?
• Where are the critical areas of protection?
• Where is the construction draining to?
The SWPPP must include a narrative describing the timing for installation of all erosion prevention and
sediment control BMPs. The SWPPP must also address phasing.
Ask for a copy of the site map and the BMP list to determine if it is specific to the construction site you’re
inspecting. The site map and BMP list can be marked up during your inspection to indicate locations
of potential violations and as a reminder to ensure that BMPs are implemented. Remember that these
items are enforceable and that the permit requires them to fully implement their SWPPP.
Remember SWPPPs are dynamic documents; they should be updated when (Section 5):
• A change in design, construction, operation, maintenance, weather or seasonal conditions have
a significant effect on stormwater discharges,
• Inspections indicate the SWPPP is not effective, or
• The SWPPP is not consistent with the terms of the permit.
Discuss with the site contact whether any
amendments have been made to the SWPPP. The
constantly changing conditions at a construction
site (from rough grading to building construction)
mean that the BMPs in the SWPPP must change as
the site conditions change.
If their SWPPP is not available for review, this will
make your inspection more difficult. Ask for a copy
of a map of the construction site, if possible, and
continue with your inspection. Note the lack of an
on-site SWPPP on the inspection form.
The SWPPP must be on-site!
Item 20.2 of the permit requires that “the SWPPP,
including all changes to it, and inspections and
maintenance records at the site during normal working
hours by permittees who have operational control of that
portion of the site.” The SWPPP can be kept in either the
field office or in an on-site vehicle.
If the SWPPP is not available, ask why and note the
response in your report. There are no legitimate excuses
for not having stormwater paperwork on-site and available
for review. Inform the construction operator that the permit
requires the SWPPP to be on-site and available for review.
If issues on-site indicate an in-depth review of the SWPPP
is necessary, request that a copy of the SWPPP be
submitted to the MPCA in the corrective actions.
Stormwater Construction Inspection Guide 7
Site inspection
A keen eye, an understanding of the construction sequencing process and accurate
documentation are the keys to an effective construction site inspection. Use the
inspection form, and take notes regarding the location and condition of BMPs, discharge
points, and inlets. Use photos to document concerns/violations and indicate on a rough
diagram where the photos were taken. Keep a written log of preliminary findings during
your inspection to facilitate your exit interview. Bring
extra copies of relevant documents (such as the permit,
application form, and construction stormwater permit
overview fact sheet) to explain the requirements, and
to leave for the construction operator if they need it.
A note about construction activity:
Construction activity, by its very nature, is a “dirty”
business. In many cases, land is cleared and graded to conform to the new site
requirements. During a rain event, even the best-managed construction sites will look
“muddy.” Your role as a construction inspector is to ensure that sediment and other
pollutants in stormwater leaving the site do not impact waters of the state. Become
familiar with typical construction practices, terminology, and conditions and use this
experience during your inspection.
A recommended construction inspection sequence follows:
1. Plan your inspection
Review the site map and plan how you will conduct the inspection (this is
particularly important for large construction sites). Identify the significant
pollutant sources and BMPs you want to inspect (silt fence installation, sediment
basins, slope stabilization, material storage areas, etc.). Consider the direction
stormwater will flow as you plan the inspection. Begin your inspection at the
low point on the construction site, observing all discharge points and walk
up the slope to inspect the rest of the site. Consider the current sequence of
construction phasing when planning your inspection.
2. Inspect discharge points and downstream, off-site areas for signs of impact
When inspecting discharge points from the site, if it appears that sediment is
leaving the site, walk downstream to document the extent of travel and impact
on receiving waters or storm drain systems. Make sure you walk “down the street”
if necessary to inspect off-site areas for signs of discharge. This is particularly
important in areas with existing curbs and gutters. Inspect down-slope municipal
catch basin inlets to ensure that they are adequately protected. Note on the
inspection form all environmental impacts and document with photographs
when possible.
Seasonal considerations
During frozen ground conditions, construction activity may
be suspended. BMPs must be in place; however, inspections
may be suspended until runoff occurs at the site or when
construction resumes. If possible, conduct inspections during
the spring thaw period.
8 Stormwater Construction Inspection Guide
In some limited situations, it may be useful to collect samples of stormwater
discharges from construction sites. Contact your MPCA regional construction
stormwater staff contact if you feel sampling may be useful in a specific situation.
3. Inspect perimeter controls
Note the type of perimeter controls installed at the site, and whether these
have been properly installed and maintained. Inspect the construction exit
to determine if there is excessive tracking of sediment from the site. Is street
sweeping being used? If so, what is the frequency? Is there evidence of additional
construction exits being used that are not in the SWPPP or are not stabilized?
Check all sediment controls. All storm drains must be protected, temporary
stockpiles must have sediment controls and cannot be placed in surface water,
including stormwater conveyances.
4. Compare BMPs in the SWPPP with construction site conditions
Are all BMPs required by the SWPPP in place? Are additional BMPs needed?
Evaluate whether BMPs have been adequately installed and maintained (see
Chapter 3 for more information on inspecting BMPs). Describe in your notes the
potential violations and their location. Look for areas where BMPs are needed,
but are missing and are not included in the SWPPP.
5. Inspect disturbed areas not currently being worked
Disturbed areas need to be temporary or permanent cover when they are not
being actively worked. All exposed soil areas must be stabilization initiated
immediately to limit soil erosion whenever any construction activity has
permanently or temporarily ceased on any portion of the site and will not resume
for a period exceeding 14 calendar days. Stabilization must be completed no later
than 14 calendar days after the construction activity in that portion of the site has
temporarily or permanently ceased.
6. Inspect areas with final stabilization
Inspect any stabilized areas to ensure that excessive erosion is not occurring.
Estimate whether the site has been stabilized with uniform perennial vegetative
cover with a density of 70% over the entire pervious area. Temporary BMPs in
areas with final stabilization must be removed and sediment must be cleaned
out of all conveyances and temporary sediment basins that will be used as
permanent water quality management basins. Areas where temporary BMPs have
been removed must be stabilized and seeded.
7. Inspect wetted perimeter areas
The normal wetted perimeters of any temporary or permanent drainage ditch
that drains water from a construction site, or diverts water around a site, must
be stabilized within 200 lineal feet from the property edge, or from the point of
discharge to any surface water. Stabilization must be completed within 24 hours
of connecting to a surface water. The remainder of the ditch must be stabilized
within 14 days.
Guidance on inspecting individual BMPs is discussed in Chapter 3.
Stormwater Construction Inspection Guide 9
Common compliance problems at construction sites
The following compliance problems are commonly found at small construction sites.
Keep these common problems in mind as you conduct inspections.
Problem #1 – No temporary or permanent cover
All exposed soil areas must have stabilization initiated immediately to limit soil
erosion whenever any construction activity has permanently or temporarily
ceased on any portion of the site and will not resume for a period exceeding 14
calendar days. Ask the contractor when particular exposed soils were last worked
to help you determine if there is compliance.
Problem #2 – No sediment controls on site
The permit requires established sediment control practices (e.g., sediment traps/
basins, down-gradient silt fences or sediment barriers, check dams, etc.) on
down-gradient perimeters before up-gradient land disturbing activities begin.
Problem #3 – No sediment control for temporary stock piles
Temporary stockpiles must have silt fence or other effective sediment controls,
and cannot be placed in surface waters (or curb and gutter systems).
Problem #4 – No inlet protection
All storm drain inlets that receive a discharge from the construction site must be
protected before construction begins, and must be maintained until the site is
stabilized. Inlet protection may be removed for a particular inlet if a specific safety
concern has been identified. Written correspondence must be documented in
the SWPPP or available within 72 hours upon request.
Problem #5 – No BMPs to minimize vehicle tracking on to the road
Vehicle exits must use BMPs such as stone pads, concrete or steel wash racks, or
equivalent systems to prevent vehicle tracking of sediment.
Problem #6 – Sediment on the road
If BMPs are not adequately keeping sediment off the street, then the permit
requires tracked sediment to be removed (e.g., street sweeping).
Problem #7 – Improper solid waste or hazardous materials management
Solid waste must be disposed of properly, and hazardous materials (including
oil, gasoline, and paint) must be properly stored (which includes secondary
containment).
Problem #8 – Dewatering at the construction site
Typically dewatering occurs where building footings are being constructed.
Have measures been taken to ensure that the pumped discharge is not causing
erosion? Is the discharge turbid and if so is it treated before discharging from the
site? Has ditching been used to dewater and if so is that water resulting in the
discharge of sediment and causing water quality impairments?
10 Stormwater Construction Inspection Guide
Problem #9 – Concrete washout
All liquid and solid wastes generated by concrete washout operations must be
contained in a leak-proof containment facility or impermeable liner.
Taking photographs
A digital camera is extremely useful during an inspection. Take digital photographs
to document your findings and provide a site overview as you write your report. Take
photos of the site entry sign, all potential violations, and a general view(s) of the
construction site. Be certain to photograph impacts to waters of the state and try to
document with photos that the construction project is the only source of the impact (not
other upstream sources), so take shots above and below the project at the impacted
waterbody. Remember that you do not need to incorporate all of the photos you take
into your inspection report. Photograph model BMPs that could be useful as examples to
other construction operators.
On the site map, indicate approximate locations of where you took photos, and the
direction of the photograph. Keep notes for each photograph you take, as you need to
describe the potential violation in your report.
When taking a photograph, make sure you keep perspective in mind. If the viewer will
have difficulty understanding how large something is (for example, a rill/gully), then use
a prop such as a person, hardhat or other object for perspective.
Exit interview
Prior to conducting your exit interview, break away from the assembled group to gather
your thoughts and prepare a list of preliminary findings. Review the inspection forms
and determine the severity of any identified deficiencies. It is best to lead off your exit
interview with one or more positive comments regarding the site and then list your
negative findings in order of severity. Therefore, come up with a few positives examples
of what they are doing right.
Debrief the person in charge. Explain that the results of the inspection are preliminary
and are not final until all documents and photos have been reviewed and a supervisor has
reviewed your report. Explain the identified deficiencies and any areas of concern (parts
of SWPPP are missing, inspections are not being done, silt fence was down, etc.). Where
possible, cite the section of the permit that requires these missing practices. While it is
important that you provide a comprehensive site assessment, it is acceptable to indicate
that you are uncertain about certain deficiencies/points and that additional review is
required.
Leave copies of any compliance assistance information, such as the MPCA fact sheets
“Overview of Minnesota’s NPDES/SDS Construction Stormwater Permit” or “Sediment and
Erosion Control for New Homeowners.” Share information on permit compliance, and
direct them to contact the MPCA office (contact phone numbers are noted on the bottom
of the inspection forms), or explain how to obtain technical guidance materials.
Lastly, don’t tell the construction operator which BMP to use. Explain the problem or the
permit requirement that must be met, and describe how other construction sites have
Stormwater Construction Inspection Guide 11
addressed typical problems. Its OK to tell the construction operator about what typically
works and what doesn’t work in the field, but don’t specify the BMP to use (especially if
it is a proprietary BMP). Ultimately, it is up to the construction operator to decide which
BMPs to use.
Report writing and follow-up
Inspection reports consist of inspection forms, a site map and a photo log. If possible,
complete all the relevant fields on the inspection forms and write your inspection report
while you are still on the construction site. This will allow you to double check any
observations and ask follow-up questions.
Remember that your inspection report is a legal document. Write legibly, accurately and
objectively. Report all violations observed at the site, and always cite the section of the
permit that was violated. Be careful not to include any information that you are unsure
of (i.e., product names). The inspection report may be the first step in a compliance
process that could reasonably be expected to be contentious. Factual errors in the report
will bring the entire report and inspection into question, and will hurt the inspector’s
credibility. Therefore, if there is any doubt about the information, it should be left out.
When writing the description of violations, items that were stated to occur but were
not observed should always be attributed to the construction operator or their
representative. For example, the representative may state that the street is swept daily,
but you do not know this as an observed fact.
Be consistent when writing your inspection reports. Identify potential violations in such
a way that another inspector can take your report and locate the problem area easily. Be
specific when you describe your observations. Don’t write “a discharge was entering the
storm drain” but rather “a discharge was entering the storm drain on the east side of the
project below the construction entrance.” As a rule, descriptions of potential violations
should be in past tense, i.e., “the silt fence was installed without being toed in.”
The photo log provides an important visual link between the written inspection report
and the actual inspection. The photo log will also help determine the severity of potential
violations. The inspection checklist should reference the photo log.
Photo log should include:
1. Size the photos so that the shortest side is 3.5 inches. Center the photos and
captions on the page. Generally, a page will have two landscape oriented photos
or one portrait. See Attachment A, Page 28, for a sample photo log.
2. Include a photo(s) that illustrates general construction site conditions. A macro
level shot provides insight into whether the site is generally in good shape
or poorly maintained. For a site that is generally in compliance, the general
construction site conditions photo may be the only picture in the log.
3. Provide photos for all potential violations. The photo serves as a record that
the findings actually occurred and provides a means of comparing future
site conditions with those on the day of inspection. Also, it’s easier to resolve
12 Stormwater Construction Inspection Guide
potential disputes with the construction operator if findings are documented
with photographs.
4. Photo captions should briefly describe what is observed in the picture. Avoid
references to the “normal” conditions in that area (“per the construction
operator” statements); these are better discussed in the inspection report.
5. Check to make sure the construction site name and NPDES/SDS permit number
match the inspection report. The best way to do this is to create a new photo log
for each construction site; problems seem to arise when inspectors recycle photo
logs by erasing the photos from one site and add those from another.
Save the photo log as the nine digit NPDES/SDS permit number followed by the facility
name, or first word of a long facility name (i.e., C00012345 Acme.doc). The NPDES/SDS
permit number is the unique value used to organize the photo logs with the reports and
make sure that none are missing.
Stormwater Construction Inspection Guide 13
Inspecting BMPs
The following BMPs are commonly implemented on small construction sites. Tips for
inspecting these BMPs are described on the following pages. For more information on
BMPs, see:
• Minnesota Stormwater Manual https://stormwater.pca.state.mn.us/index.php/
Main_Page
• Minnesota Urban Small Sites BMP Manual: Stormwater Best Management
Practices for Cold Climates, Metropolitan Council, 2001.
https://metrocouncil.org/Wastewater-Water/Planning/Water-Resources-
Management/Water-Quality-Management-Key-Roles.aspx
Both manuals provide details on the standards and specifications for installing and
maintaining these and other stormwater BMPs.
The BMPs are generally organized by the order an inspector will typically encounter them
in the field when conducting an inspection.
The BMPs in this list were selected because they are commonly found on construction
sites disturbing less than five acres of soil.
3Chapter
Tips on
inspecting BMPs
14 Stormwater Construction Inspection Guide
Storm drain inlet protection
Storm drain inlet protection prevents sediment from
entering a storm drain by surrounding or covering the
inlet with a filtering material. This allows sediment-laden
runoff to pond and settle before entering the storm
drain.
Several types of filters are commonly used for inlet
protection: silt fence, sand bags or block and gravel.
The type of filter used will depend on inlet type (curb
inlet, drop inlet), slope, and amount of flow. Many
different commercial inlet filters are also available. Some
commercial inlet filters are placed in front of or on top of
an inlet, others are placed inside the inlet and under the
grate.
Permit requirements:
• All storm drain inlets must be protected by
appropriate BMPs during construction until all
sources with potential for discharging to the
inlet have been stabilized. Inlet protection may
be removed if a specific safety concern has been
identified and the Permitee(s) have received
written correspondence from the jurisdictional
authority (Item 9.7).
• All sediment control BMPs must be inspected
to ensure integrity and effectiveness. All
nonfunctional BMPs must be repaired, replaced,
or supplemented with functional BMPs.
(Section 11).
Inspection tips:
Inlet protection is a secondary BMP. Make sure
that erosion controls or additional sediment
controls are also in place.
The inlet protection must not block the storm
drain or cause flooding.
Inlet protection must be in place immediately
after storm drains are installed (or before land
disturbance activities begin in an area with
existing storm drains).
Sediment accumulation must be removed after
each storm event if it impedes flow through the
filter.
Make sure there are not any “gaps” allowing
unfiltered stormwater to enter the inlet.
Figure 1. Sand or gravel bags can be used to filter
stormwater runoff before entering a catch basin.
Commercial products are also available that fit in
front of or inside the catch basin.
Figure 3. Silt fence can also be used to protect a drop
Figure 2. Sand or gravel bags used to protect a drop
inlet.
Stormwater Construction Inspection Guide 15
Stabilized construction exit
A rock construction exit can reduce the amount of sediment transported onto paved
roads by vehicles. The construction exit does this by knocking mud off the vehicle tires
before the vehicle enters a public road.
Permit requirements:
• Vehicle tracking of sediment from the construction site must be minimized by
BMPs such as stone pads, concrete or steel wash racks, or equivalent systems.
Street sweeping must be used if such BMPs are not adequate to prevent
sediment from being tracked onto the street (Item 9.11).
• Construction site vehicle exit locations must
be inspected for evidence of off-site sediment
tracking onto paved surfaces. Permittees
must use street sweeping if vehicle tracking
BMPs are not adequate to prevent sediment
tracking onto the street (Item 9.12).
Inspection tips:
Is there evidence of sediment tracking from
the site? (Street sweeping may be necessary if
sediment tracking is evident).
Is there evidence that vehicles are leaving the
site from other locations, and not using the
designated construction exits?
Does the aggregate need to be replaced or
replenished?
Is the construction exit long enough to
remove mud from the tires (50 ft. minimum)?
Is the site graded away from the construction exit to prevent runoff from leaving
the site?
Figure 4. Stabilized construction exit.
16 Stormwater Construction Inspection Guide
Silt fence/other sediment barrier
A silt fence or sediment filter (such as a fiber roll or wattle) is a down-gradient barrier intended
to intercept sheet flow runoff and settle out sediment upslope while allowing runoff to filter
through.
Permit requirements:
Sediment control practices must be established on all down-
gradient perimeters before any upgradient land disturbing
activities begin. These practices must remain in place until
final stabilization has been established (Item 9.2). All silt
fences must be repaired, replaced, or supplemented when
they become nonfunctional or the sediment reaches 1/2 of
the height of the fence. These repairs must be made within 24
hours of discovery, or as soon as field conditions allow access
(Item 11.4).
Inspection tips:
Is the silt fence installed along the contour (on a level
horizontal plane)?
Are the ends turned up (J-hooks) to help pond the water
behind the filter?
Is the filter trenched-in with the stakes on the downhill
side (trench must be six inches deep by six inches wide)?
Has sediment been removed when it reaches
1/2 the height of the barrier?
Sediment barriers should not be used as check dams or
where concentrated flow is expected.
Figure 5. Illustration of silt fence installed along
the contour.
Figure 6. Detail of silt fence installation.
Figure 7. Illustration of “J-hooks” used during silt
fence installation.
Stormwater Construction Inspection Guide 17
Key inspection area: Inadequate installation
• Soil should be compacted after trenching.
• The stakes used to hold the silt fence must be
on the down-slope side.
Key inspection area: Improper placement
• A silt fence is not adequate protection for
steep, long slopes. The drainage area must be
no greater than ¼ acre per 100 feet of fence;
i.e., silt fences must be spaced 60-110 ft. apart
on long slopes.
Key inspection area: Maintenance
• Torn or degraded silt fence fabric must be
replaced immediately.
Diversion ditches/berms
Diversion ditches or berms direct off-site runoff away from unprotected slopes or
direct sediment-laden runoff to a sediment trapping structure. A diversion ditch can be
located at the upslope side of a construction site to prevent surface runoff from entering
the disturbed area. Ditches or berms on steeper slopes may need to consider erosive
velocities. Also, ensure that the diverted water is released through a stable outlet and
does not cause downstream flooding.
Inspection tips:
Check to make sure the diversion discharges to a
stable outlet or channel.
Check to see if diversion ditches and berms have
been seeded.
Is the diversion eroding? (channel grades should be
relatively flat).
Check dams may be necessary if high velocity flows
are present.
Figure 8. Fiber roll installation and detail.
Figure 9. Diversions should be used to divert
stormwater away from disturbed areas.
18 Stormwater Construction Inspection Guide
Mats, mulches, and blankets
Mats, mulches and blankets are used for temporary stabilization and establishing
vegetation of disturbed soils. Mats and blankets are typically used on slopes or channels
while mulches are effective in helping to protect the soil surface and foster the growth of
vegetation.
Inspection tips:
The blanket or mat must come into complete
contact with the soil.
Check that the top of the blanket is trenched-in
(there should be no evidence of water flowing
under the blanket or mat).
Mulch should not be placed in concentrated
flow areas.
Check to see if erosion is occurring in the
mulched area (more mulch may need to
be applied).
Check blankets and mats to see if sections are
overlapped 4-6 inches and staples are 12 inches
apart on tops and 24 inches apart down the
sides and in the middle.
Temporary sediment trap or pond
A temporary sediment trap or pond is a small, temporary ponding area formed by
constructing an earthen embankment with an outlet across a swale. Temporary sediment
traps are intended to detain sediment-laden runoff from small, disturbed areas long
enough to allow the majority (at least 75%) of the sediment to settle out.
Sediment traps are designed for small areas. The volume of the trap must be at least
1,800 cubic feet per acre of contributing drainage.
Inspection tips:
Check the location of the sediment trap. Failure of the trap should not pose a risk
to life or property.
Sediment in the trap should be removed after it reaches about 1/2 the
design volume.
The trap should not be installed in a main stream or near culvert outlets.
Check the outlet for needed maintenance.
Figure 10. Erosion control blanket.
Stormwater Construction Inspection Guide 19
Vegetative stabilization
Vegetative stabilization includes temporary or permanent seeding and sodding.
Vegetative stabilization helps prevent erosion at construction sites by reestablishing
vegetation on exposed soils. Native and noninvasive species are highly preferred to
introduced grasses.
Permit requirement (Item 8.4):
All exposed soil area must have stabilization initiated immediately to limit soil erosion.
Stabilization must be completed no later than 14 calendar days after construction
activity in that portion of the site has temporaily or permanetly ceased. Temporary
stock piles without significant silt, clay or organic components and the constructed
based components of the roads, pacing lots, and similar surface are exempt from this
requirement.
Inspection tips:
Are all exposed soil areas stabilized?
Check for signs of erosion in vegetated areas.
Concentrated flows should not be allowed across newly seeded slopes.
If late in the year, a slope may need to be mulched rather than seeded.
Permanent stormwater treatment system
For projects that replace pervious surfaces with one or more acres of cumulative
impervious surface, a permanent stormwater management system that treats one inch
runoff from the new impervioius surface is required. See Section 15 of the permit for
additional information.
For projects where the full volume reduction requirement cannot be met on-site, (e.g. the
site has infiltration prohibitions), permittees must document the reasons in the SWPPP.
For linear projects where permittees cannot treat the entire water quality volume within
the existing right-of-way, permittees must make a reasonable attempt to obtain right-of-
way, easement or other permission for stormwater treatment during the project planning
process. Documentation attempts must be in the SWPPP.
Permittees must first consider volume reduction practices on-site (e.g., infiltration or
other) when designing the permanent stormwater treatment system. If the permit
prohibits infiltration, permittees may consider a wet sedimentation basin, filtration basin
or regional pond.
• Infiltration/filtration. Treatment can include infiltration basins and trenches,
rainwater gardens, sand filters, bioretention areas, and enhanced swales. The
water quality volume treated should be 1 inch of new impervious surface.
(Section 16 & Section 17).
• Wet sedimentation basin. Permanent storage volume (dead storage) of 1800 cubic
feet of storage per acre that drains to the basin must be provided. The water
20 Stormwater Construction Inspection Guide
quality volume (live storage) must be discharged at no more than 5.66 cubic feet
per second (CFS) per acre of surface area of the pond. The water quality volume
treated should be one inch times of new impervious surface. (Section 18).
• Regional Ponds. Written authorization to discharge to a regional pond must
be included in the SWPPP, and the pond must meet the permit’s design
requirements. (Section 19)
• Combination of the above practices. SWPPP must document the volume that each
practices addresses.
• Alternative method. An alternative method must be approved in advance by the
MPCA. Check the SWPPP to see if approval and additional documentation is
provided.
Solid waste/hazardous materials management
Section 12 of the permit requires construction sites to
implement pollution prevention measures. At a minimum,
sites are required to:
• Properly dispose of solid waste.
• Hazardous materials must be properly stored,
including secondary containment, with restricted
access to prevent vandalism. Oil, gasoline and paint
are hazardous materials often used at construction
sites.
• Limit external washing of vehicles and contain
runoff. Engine degreasing is prohibited.
Permit requirements:
• Solid Waste: Collected sediment, asphalt and
concrete millings, floating debris, paper, plastic,
fabric, construction and demolition debris and other
wastes must be disposed of properly and must
comply with MPCA disposal requirements. (Item
12.9).
• Hazardous Materials: Oil, gasoline, paint and any hazardous substances must
be properly stored, including secondary containment, to prevent spills, leaks or
other discharge. Access to storage areas must be restricted to prevent vandalism.
Storage and disposal of hazardous waste must be in compliance with MPCA
regulations. (Item 12.4).
• Spills must be reported to the Minnesota Duty Officer 1-800-422-0798.
Figure 11. Example of hazardous materials storage
(doors removed for illustrative purposes only).
Access to hazardous materials must be restricted.
Stormwater Construction Inspection Guide 21
• Concrete washout onsite: All liquid and solid wastes generated by concrete
washout operations must be contained in a leak-proof containment facility or
impermeable line. A compacted clay liner that does not allow washout liquids
to enter ground water is considered and impermeable liner. The liquid and solid
wastes must not contact the ground, and there must not be runoff from the
concrete washout operations or areas. Liquid and solid wastes must be disposed
of properly and in compliance with MPCA regulations. A sign must be installed
adjacent to each washout facility to inform concrete equipment operators to
utilize the proper facilities. (Item 12.9).
Inspection tips:
Does the construction site have dumpsters or other containers for debris and
solid waste?
Is there evidence of solid waste or debris in the storm drain system?
Are oil, gasoline and paint properly stored?
Does the construction operator allow vehicles to be washed on-site?
Are solid waste and hazardous materials stored away from receiving waters and
catch basins?
Is there evidence of hazardous materials being disposed of in the solid
waste bins?
Is there evidence that the solid waste or hazardous materials containers
have leaked?
Are vehicles or equipment fueled on-site? Is this area bermed or away from
receiving waters and storm drains?
Are all hazardous materials containers properly labeled?
Are concrete washouts properly installed away from receiving waters and
storm drains?
Is there a sign adjacent to each washout facility to inform concrete equipment
operators to utilize the proper facility.
22 Stormwater Construction Inspection Guide
Specific referral procedures are detailed in contracts between the MPCA and non-MPCA
inspectors. In most instances, referrals will follow this general practice. Cases may be
referred directly to the MPCA from approved agencies. At this point the MPCA determines
if enforcement actions are warranted and if proper documentation has been filed. If
the MPCA determines that no action is required, because of the lack of documentation
or insufficient information or evidence, the case will be referred back with a letter of
explanation. If MPCA staff determine that action is required the case will be pursued.
Cases that meet MPCA requirements will be brought through the MPCA enforcement
process in conjunction with the referring approved agency. Most times a parallel request
will be made by the referring approved agency to engage with local enforcement
measures. These measures may include: having the plan-approving agency (zoning and
planning departments) refrain from issuing or, in some cases, revoking any building or
grading permits until outstanding violations are remedied.
The following are three common violations at small construction sites and the potential
level of enforcement response by the MPCA and approved partners. Further information
and details on MPCA enforcement response or guidance on inspection reports and field
letter of warning use can be obtained from the MPCA Enforcement Response
Plan (ERP).
For failure to obtain an NPDES stormwater permit
Citation: 7001.1035, 7001.1040 and 7001.1030.
Suggested enforcement action: Administrative Penalty Order (APO).
Evidence needed: photos of the construction activity, DELTA permit search, a completed
inspection report, pollutant discharge documentation (when occurring), size of site, cite
the “failure to obtain a permit” violation,
Required action: Immediately cease construction work. Create corrective actions that will
prevent harm or correct/minimize releases. Apply for permit ASAP and prior to continued
site activity. Follow up with appropriate enforcement action.
4Chapter
Referring enforcement
cases to the MPCA
Stormwater Construction Inspection Guide 23
For discharging sediment into waters of the state
Citation: Minnesota Statute 115.061 or Minn. R. 7001.0210.
Suggested enforcement action: APO/Stipulation Agreement.
Evidence needed: Delineation of sediment plume, photos, and inspection report which
describes the impacts with good factual records.
Required action: Create corrective actions to stop discharge and prevent harm or correct/
minimize releases, report discharges to appropriate agencies. Proceed with appropriate
enforcement action; most cases involving discharges typically involve penalties
depending on the seriousness, length of time and response to the discharge.
For violations of the NPDES/SDS stormwater permit requirements
Citation: NPDES/SDS Permit MN R100001
Suggested enforcement action: Letter of Warning, APO or Stipulation Agreement.
Evidence needed: Review erosion and sediment control plans, photos, and inspection
reports that describes any impacts with good factual records of failure of the
permit conditions.
Required action: Clearly and concisely document any violations, including the location of
the violation and the part of the permit that the construction operator is violating. Create
corrective actions that will result in compliance with the permit and, if appropriate,
establish a time frame for compliance. Write clearly and concisely. Proceed with
enforcement as appropriate. Cases involving environmental harm or potential for harm
may involve penalties depending on the seriousness, length of time and response to the
corrective actions. Case by case evaluation is necessary to make these determinations.
If a reinspection is necessary, set a time or date for this (either scheduled with the
construction operator or an unannounced inspection).
Enforcement options available
There are a suite of enforcement options available to local government or state agencies
ranging from field requests to formal notices and various penalty actions, including local
citations, administrative penalty orders, stipulation agreements, stop work orders and permit
revocations.
24 Stormwater Construction Inspection Guide
This Stormwater Inspection Guide is available online, as are the additional resources on
stormwater BMPs listed below:
MPCA Stormwater Inspection Guide
www.pca.state.mn.us/publications/wq-strm2-10.pdf
MPCA Minnesota Stormwater Manual
www.pca.state.mn.us/water/stormwater/stormwater-manual.html. The first half of the
manual is dedicated to the general Minnesota context for stormwater management. The
second half includes diagrams and formulas, it is intended for professional, but useful for
homeowners.
MPCA Stormwater Program
www.pca.state.mn.us/water/stormwater/index.html. Click on the construction stormwater
program to get copies of the construction permit, application, fact sheets, information on
special waters and staff contacts.
MPCA Stormwater BMP Manual
www.pca.state.mn.us/water/pubs/sw-bmpmanual.html. An electronic copy of the MPCA’s
Protecting Water Quality in Urban Areas: Best Management Practices for Dealing with
Stormwater Runoff from Urban, Suburban and Developing Areas of Minnesota (2000).
Includes information on all types of stormwater control practices.
Metropolitan Council’s Urban Small Sites BMP Manual
https://metrocouncil.org/Wastewater-Water/Planning/Water-Resources-Management/
Water-Quality-Management-Key-Roles.aspx
An electronic copy of the Minnesota Urban Small Sites BMP Manual: Stormwater Best
Management Practices for Cold Climates (2001). This BMP manual provides information on
construction and permanent stormwater BMPs.
Minnesota Erosion Control Association
www.mnerosion.org. An organization that is advancing effective stormwater management
and erosion and sediment control techniques and practices.
International Erosion Control Association
www.ieca.org Association for erosion and sediment control professionals.
5Chapter
Additional resources
Stormwater Construction Inspection Guide 25
The following selected definitions are reprinted from the MPCA’s construction permit. For
additional definitions, see the construction permit.
“Best management practices (BMPs)”
Erosion and sediment control and water quality management practices that are the most
effective and practicable means of controlling, preventing, and minimizing degradation
of surface water, including avoidance of impacts, construction-phasing, minimizing the
length of time soil areas are exposed, prohibitions, and other management practices
published by state or designated area-wide planning agencies. Individual BMPs found
in the construction permit are described in the current version of Minnesota Stormwater
Manual. BMPs must be adapted to the site and can be adopted from other sources.
However, they must be similar in purpose and at least as effective and stringent as
the MPCA’s BMPs. (Other sources include manufacturers specifications, Stormwater
Management for Construction Activities: Developing Pollution Prevention Plans and Best
Management Practices, U.S. Environmental Protection Agency 1992, and Erosion Control
Design Manual, Minnesota Department of Transportation, et al, 1993).
“Common plan of development or sale”
A contiguous area where multiple separate and distinct land disturbing activities may be
taking place at different times, on different schedules, but under one proposed plan. One
plan is broadly defined to include design, permit application, advertisement or physical
demarcation indicating that land-disturbing activities may occur.
“Construction activity”
Construction activity as defined in 40 C.F.R. part 122.26(b)(14)(x) and small construction
activity as defined in 40 C.F.R. part 122.26(b)(15). This includes a disturbance to the land
that results in a change in the topography, existing soil cover (both vegetative and non-
vegetative), or the existing soil topography that may result in accelerated stormwater
runoff, leading to soil erosion and movement of sediment into surface waters or drainage
systems. Examples of construction activity may include clearing, grading, filling and
excavating. Construction activity includes the disturbance of less than one-acre of total
land area that is a part of a larger common plan of development or sale if the larger
common plan will ultimately disturb one acre or more.
6Chapter
Definitions
26 Stormwater Construction Inspection Guide
“Erosion prevention”
Measures employed to prevent erosion including but not limited to: soil stabilization
practices, limited grading, mulch, temporary or permanent cover, and construction
phasing.
“Final stabilization” requires all of Parts 1-5 or Part 6:
1. All soil disturbing activities at the site have been completed and all soils must be
stabilized by a uniform perennial vegetative cover with a density of 70% over the
entire pervious surface area, or other equivalent means necessary to prevent soil
failure under erosive conditions.
2. The permanent stormwater treatment system meets all requirements in
Section 15. This includes but is not limited to, a final clean out of temporary or
permanent sedimentation basins that are to be used as permanent water quality
management basins and final construction or maintenance of infiltration basins.
All sediment must be removed from conveyance systems and ditches must be
stabilized with permanent cover.
3. Prior to submission of the NOT, all temporary synthetic and structural erosion
prevention and sediment control BMPs (such as silt fence) must be removed on
the portions of the site for which the Permittee is responsible. Best Management
Practices designed to decompose on site (such as some compost logs) may be
left in place.
4. For residential construction only, individual lots are considered finally stabilized if
the structure(s) are finished and temporary erosion protection and downgradient
perimeter control has been completed and the residence has been sold to
the homeowner. Additionally, the Permittee must distribute the MPCA’s
“Homeowner Fact Sheet” to the homeowner to inform the homeowner of the
need for, and benefits of, permanent cover.
5. For construction projects on land used for agricultural purposes (e.g., pipelines
across crop or range land) Final Stabilization may be accomplished by returning
the disturbed land to its preconstruction agricultural use.
6. A Permittee may terminate permit coverage prior to completion of all
construction activity if all of the following conditions are met in addition to Part 2
and 3 and where applicable, Part 4 or Part 5.
a. Construction activity has ceased for at least 90 days.
b. At least 90% (by area) of all originally proposed construction activity has been
completed and permanent cover established on those areas.
c. On areas where construction activity is not complete, permanent cover has
been established.
“Operator”
The person (usually the general contractor), designated by the owner, who has day-
to-day operational control and/or the ability to modify project plans and specifications
related to the SWPPP. The person must be knowledgeable in those areas of the permit for
which the operator is responsible. (Section 1 – Section 3, Section 5, Section 8 – Section
13).
Stormwater Construction Inspection Guide 27
“Owner”
The person or party possessing the title of the land on which the construction activities
will occur; or if the construction activity is for a lease, easement, or mineral rights license
holder, the party or individual identified as the lease, easement or mineral rights license
holder; or the contracting government agency responsible for the construction activity.
“Permittee”
A person(s), firm, or governmental agency or other institution that signs the application
and is responsible for compliance with the terms and conditions of the permit.
“Sediment control”
Methods employed to prevent sediment from leaving the site. Sediment control practices
include silt fences, sediment traps, earth dikes, drainage swales, check dams, subsurface
drains, pipe slope drains, storm drain inlet protection, and temporary or permanent
sedimentation basins.
“Stormwater”
Defined under Minn. R. 7077.0105, subp. 41(b), and includes precipitation runoff,
stormwater runoff, snow melt runoff, and any other surface runoff and drainage.
“Stormwater Pollution Prevention Plan”
A plan for stormwater discharge that includes erosion prevention measures, sediment
controls and permanent stormwater Management System that, when implemented, will
decrease soil erosion on a parcel of land and decrease off-site nonpoint pollution.
“Surface water or waters”
All streams, lakes, ponds, marshes, wetlands, reservoirs, springs, rivers, drainage systems,
waterways, watercourses, and irrigation systems whether natural or artificial, public or
private.
“Temporary erosion protection”
Methods employed to prevent erosion. Examples of temporary cover include; straw,
wood fiber blanket, wood chips, and erosion netting.
“Waters of the state”
Defined in Minn. Stat. § 115.01, subd. 22 as all streams, lakes, ponds, marshes,
watercourses, waterways, wells, springs, reservoirs, aquifers, irrigation systems, drainage
systems and all other bodies or accumulations of water, surface or underground, natural
or artificial, public or private, which are contained within, flow through, or border upon
the state or any portion thereof.
28 Stormwater Construction Inspection Guide
Acme construction (permit number)
Inspected by: (Inspector’s name, office, phone number)
Inspection date: January 5, 2004 Page 1 of 3
Construction site name and
inspector’s last name, office,
and phone number are
centered in the header and
must appear on all pages.
Generally each page will
have two landscape or one
portrait picture(s). To size
each picture, right-click
on the picture and select
Format Picture for sizing. For
landscape view, set height
to 3.5” and width is set by
MS Word (make sure Lock
Aspect Ratio is checked ON.)
For portrait view, set width to
3.5” and height is set by MS
Word.
Inspection date and
sequential page
numbering in the
footer must appear on
all pages.
Photo 1: Well-maintained and labeled concrete truck washout
Photo 2: Hay bales and silt fence that are in need of
Attachment A - Photo log
Stormwater Construction Inspection Guide 29
Attachment B - Violation citations
NPDES/SDS General Stormwater Permit for
Construction activity violation citations
Citation Permit section or rule
No permit Minn. R. 70090.2010
subp. 1, 2, 3 (permit required,
permit application deadline, and
compliance requirements for
unpermitted construction, respectively)
Change of coverage Item 3.7
Erosion control practices during construction
a) All exposed soil must be stabilized no later than 14 days
after the construction activity in that portion of the site
has temporarily or permanently ceased Item 8.4
b) Normal wetted perimeter of drainage system - 200’
within 24 hours of connecting Item 8.6
c) Energy dissipation (temp. or perm.) within 24 hours Item 8.9
Sediment control practices during construction
a) Lacking sediment control practices Overloaded
systems eliminated, no unbroken slopes 75’ @ 3:1> Item 9.3
b) Temporary sediment basin required Item 9.13
c) Inlet BMPs not functional Item 9.7
d) Perimeter controls/soil disturbance Item 9.2
Inspections and maintenance
a) Maintenance of erosion and sediment
temporary/permanent cover Item 11.4
b) Temporary sediment basin 1⁄2-volume Item 11.8
c) Recovery of sediment in waters (name water body) Item 11.5
– Duty to notify, avoid and recover water pollution Minn. Stat. § 115.061
– Nuisance conditions prohibited (define discharge) Minn. R. 7050.0210, subp. 2
d) Vehicle tracking Item 11.6
Inspections and records retention Section 11
a) SWPPP development required Section 5
SWPPP requirements: Item 5.2
– BMPs/locations procedures Item 5.5
– Site map/flow arrows Item 5.9
– Phased areas Item 5.18
– Surface waters/wetlands 1 mile Item 5.10
– Methods for final stabilization Item 5.17
b) Inspections (specifically note failed maintenance) Section 11
c) Training requirement documentation Item 21.2
30 Stormwater Construction Inspection Guide
Permanent stormwater treatment
>One acre impervious, permanent treatment required Section 15
a) Wet sedimentation basin Section 18
• Regional ponds Section 19
• Infiltration/filtration (hydro analysis) Section 16/Section17
• Alternative methods, 90-day review, monitoring
b) Pretreatment required Item 16.6/Item 17.5
c) Dewatering Section 10
d) Turbid discharges off site or waters of the state Minn. R. 7050. 0210, subp. 2
e) Wetland impacts: authorization and mitigation
Management pollution prevention
a) Solid waste disposed of properly Item 12.5
b) Hazardous materials in secondary containment
and restricted access Item 12.4
c) Defined areas for construction vehicles external washing Item 12.8
d) Defined concrete washout on site and with a sign Item 12.9
Stormwater Construction Inspection Guide 31
Letter of warning (LOW)
A notice to a regulated party (RP) that documents violations discovered during an
inspection, complaint follow-up or review of submittals. The LOW typically includes a
reference of the statute, rule, permit condition or checklist that are violated. The LOW
typically requires the regulated party to complete specific corrective actions to return
the facility to compliance. The LOW usually gives a regulated party between 7-30 days to
complete required corrective actions.
Request for information (RFI)
A notice to an RP requiring information. Occasionally additional information is required
to determine the status of compliance or for an RP to respond to violations discovered.
This information can be used to determine if elevated enforcement (including penalties)
is appropriate.
Corrective actions (LOW or RFI)
Requirements to correct field conditions and to come into compliance with the permit,
statute or rules and must be responded to in the period noted on this field report.
This response (including any lack of response) is considered by the MPCA and future
enforcement for the violations discovered.
Attachment B - Violation citations
(continued)
32 Stormwater Construction Inspection Guide
Site name/Location __________________________________ Date of inspection____________
Permanent – temporary (circle) sedimentation basins: (location/ID)_________________________________
Required basin installed (> 10 acres/ single point (T) or >1 acre new impervious (P)? Yes No
Does basin have energy dissipation for outlet? Yes No
Stabilized emergency overflow outlet? Yes No
Was basin constructed /operational concurrent with construction? Yes No
Are slopes stabilized with perm cover or temp erosion protection? Yes No
Is basin connected to surface waters? Yes Name/description waters: ___________________________
Was discharge- connection stabilized within 24 hours of connecting? Yes No
Dewatering: Onsite to a temp. settling basin? Yes No If offsite, is water turbid? Yes No
If no settling basin, was appropriate BMPs for turbidity and scour applied? Yes No
Is discharge from site creating a nuisance conditions or WQ violations? Yes No
Observations:
Permanent – temporary (circle) sedimentation basins: (location/ID)_________________________________
Required basin installed (> 10 acres/ single point (T) or >1 acre new impervious (P)? Yes No
Does basin have energy dissipation for outlet? Yes No
Stabilized emergency overflow outlet? Yes No
Was basin constructed /operational concurrent with construction? Yes No
Are slopes stabilized with perm cover or temp erosion protection? Yes No
Is basin connected to surface waters? Yes Name/description waters: ___________________________
Was discharge- connection stabilized within 24 hours of connecting? Yes No
Dewatering: Onsite to a temp. settling basin? Yes No If offsite, is water turbid? Yes No
If no settling basin, was appropriate BMPs for turbidity and scour applied? Yes No
Is discharge from site creating a nuisance conditions or WQ violations? Yes No
Observations:
Permanent – temporary (circle) sedimentation basins: (location/ID)_________________________________
Required basin installed (> 10 acres/ single point (T) or >1 acre new impervious (P)? Yes No
Does basin have energy dissipation for outlet? Yes No
Stabilized emergency overflow outlet? Yes No
Was basin constructed /operational concurrent with construction? Yes No
Are slopes stabilized with perm cover or temp erosion protection within 200’ of surface water? Yes No
Is basin connected to surface waters? Yes Name/description waters: ___________________________
Was discharge- connection stabilized within 24 hours of connecting? Yes No
Dewatering: Onsite to a temp. settling basin? Yes No If offsite, is water turbid? Yes No
If no settling basin, was appropriate BMPs for turbidity and scour applied? Yes No
Is discharge from site creating a nuisance conditions or WQ violations? Yes No
Observations:
Attachment C - Temporary,
permanent sediment basin checklist
Standard Operating Procedure
1
Minimum Control Measure 5
Post-Construction Stormwater Management
5.1 PLAN REVIEW
Activities and Definition
Plans that are submitted to the City of Medina for approval will have a review process to guarantee
that post-construction stormwater standards are being met. The City shall require owners of
construction activity to submit site plans with postconstruction stormwater management BMPs
designed with accepted engineering practices to the City for review and confirmation that regulatory
mechanism(s) requirements have been met, prior to start of construction activity.
The approach to meet the performance standard for Volume, Total Suspended Solids (TSS), and
Total Phosphorus (TP) required by the Permit is to retain a runoff volume equal to one-inch times
the area of the proposed increase of impervious surface on-site, match the predevelopment runoff
conditions, and adopt the Minimal Impact Design Standards (MIDS).
Maintain the following post-construction stormwater management regulatory mechanisms that prohibits
non-stormwater discharges into the City’s MS4, requires the use of green infrastructure, and prohibits
infrastructure, and prohibits infiltration in certain situations, and restricts it in others:
• Ordinance
The following requirements are incorporated into the City’s regulatory mechanism:
a. Require owners of construction activity to submit site plans with post-construction stormwater
management BMPs designed with accepted engineering practices to the City for review and
confirmation that regulatory mechanism(s) requirements have been met, prior to start of
construction activity
b. Require owners of construction activity to treat the water quality volume on any project where
the sum of the new impervious surface and the fully reconstructed impervious surface equals one
or more acres
c. For construction activity (excluding linear projects), the water quality volume must be calculated
as one (1) inch times the sum of the new and the fully reconstructed impervious surface.
d. For linear projects, the water quality volume must be calculated as the larger of one (1) inch
times the new impervious surface or one-half (0.5) inch times the sum of the new and the fully
reconstructed impervious surface. Where the entire water quality volume cannot be treated
Standard Operating Procedure
2
within the existing right-of-way, a reasonable attempt to obtain additional right-of-way,
easement, or other permission to treat the stormwater during the project planning process must
be made. Volume reduction practices must be considered first, as described in item 20.8. Volume
reduction practices are not required if the practices cannot be provided cost effectively. If
additional right-of-way, easements, or other permission cannot be obtained, owners of
construction activity must maximize the treatment of the water quality volume prior to discharge
from the MS4
e. Volume reduction practices (e.g., infiltration or other) to retain the water quality volume on-site
must be considered first when designing the permanent stormwater treatment system. This
permit does not consider wet sedimentation basins and filtration systems to be volume reduction
practices. If this permit prohibits infiltration as described in item 20.9, other volume reduction
practices, a wet sedimentation basin, or filtration basin may be considered.
1. Volume reduction practices must be considered first, as described in item 20.8.
2. Volume reduction practices are not required if the practices cannot be provided cost
effectively.
3. If additional right-of-way, easements, or other permission cannot be obtained, owners of
construction activity must maximize the treatment of the water quality volume prior to
discharge from the MS4.
4. The General Permit does not consider wet sedimentation basins and filtration systems to
be volume reduction practices. If the General Permit prohibits infiltration as described in
item 20.9, other volume reduction practices, a wet sedimentation basin, or filtration basin
may be considered.
5. For non-linear projects, where the water quality volume cannot cost effectively be treated
on the site of the original construction activity, the City must identify, or may require
owners of the construction activity to identify, locations where off-site treatment projects
can be completed.
6. If the entire water quality volume is not addressed on the site of the original construction
activity, the remaining water quality volume must be addressed through off-site treatment
and, at a minimum, ensure the requirements of items 20.11 through 20.14 are met
f. Infiltration systems must be prohibited when the system would be constructed in areas:
1. That receive discharges from vehicle fueling and maintenance areas, regardless of the
amount of new and fully reconstructed impervious surface.
2. Where high levels of contaminants in soil or groundwater may be mobilized by the
Standard Operating Procedure
3
infiltrating stormwater. To make this determination, the owners and/or operators of
construction activity must complete the MPCA’s site screening assessment checklist,
which is available in the Minnesota Stormwater Manual, or conduct their own
assessment. The assessment must be retained with the site plans.
3. Where soil infiltration rates are more than 8.3 inches per hour unless soils are amended to
slow the infiltration rate below 8.3 inches per hour.
4. With less than three (3) feet of separation distance from the bottom of the infiltration
system to the elevation of the seasonally saturated soils or the top of bedrock.
5. Of predominately Hydrologic Soil Group D (clay) soils.
6. In an Emergency Response Area (ERA) within a Drinking Water Supply Management
Area (DWSMA) as defined in Minn. R. 4720.5100, Subp. 13, classified as high or very
high vulnerability as defined by the Minnesota Department of Health.
7. In an ERA within a DWSMA classified as moderate vulnerability unless the City perform
or approve a higher level of engineering review sufficient to provide a functioning
treatment system and to prevent adverse impacts to groundwater.
8. Outside of an ERA within a DWSMA classified as high or very high vulnerability unless
the City perform or approve a higher level of engineering review sufficient to provide a
functioning treatment system and to prevent adverse impacts to groundwater.
9. Within 1,000 feet up-gradient or 100 feet down gradient of active karst features.
10. That receive stormwater runoff from these types of entities regulated under NPDES for
industrial stormwater: automobile salvage yards; scrap recycling and waste recycling
facilities; hazardous waste treatment, storage, or disposal facilities; or air transportation
facilities that conduct deicing activities.
g. For non-linear projects, where the water quality volume cannot cost effectively be treated on the
site of the original construction activity, the City must identify, or may require owners of the
construction activity to identify, locations where off-site treatment projects can be completed. If
the entire water quality volume is not addressed on the site of the original construction activity,
the remaining water quality volume must be addressed through off-site treatment and, at a
minimum, ensure the requirements of permit items 20.11 through 20.14 are met
h. Ensure off-site treatment project areas are selected in the following order of preference:
1. Locations that yield benefits to the same receiving water that receives runoff from the
original construction activity
2. Locations within the same DNR catchment area as the original construction activity
Standard Operating Procedure
4
3. Locations in the next adjacent DNR catchment area up-stream
4. Locations anywhere within the City’s jurisdiction
i. Off-site treatment projects must involve the creation of new structural stormwater BMPs or the
retrofit of existing structural stormwater BMPs, or the use of a properly designed regional
structural stormwater BMP. Routine maintenance of structural stormwater BMPs already
required by this permit cannot be used to meet this requirement.
j. Off-site treatment projects must be completed no later than 24 months after the start of the
original construction activity. If the City of Medina determines that more time is needed to
complete the treatment project, the City must provide the reason(s) and schedule(s) for
completing the project in the annual report.
k. If the City of Medina receives payment from the owner of a construction activity for off-site
treatment, the City must apply any such payment received to a public stormwater project, and all
projects must comply with permit items 20.11 through 20.13.
l. Include the establishment of legal mechanism(s) between the City and owners of
structural stormwater BMPs not owned or operated by the City, that have been constructed to
meet the requirements in Section 20. The legal mechanism(s) must include provisions that, at a
minimum
1. Allow the City to conduct inspections of structural stormwater BMPs not owned or
operated by the City, perform necessary maintenance, and assess costs for those structural
stormwater BMPs when the City determine the owner of that structural stormwater BMP
has not ensured proper function.
2. Are designed to preserve the City’s right to ensure maintenance responsibility, for
structural stormwater BMPs not owned or operated by the City, when those
responsibilities are legally transferred to another party.
3. Are designed to protect/preserve structural stormwater BMPs. If structural stormwater
BMPs change, causing decreased effectiveness, new, repaired, or improved structural
stormwater BMPs must be implemented to provide equivalent treatment to the original
BMP
Process
a. Review City ordinances (Subdivisions and Zoning), the City of Medina Comprehensive
Plan, the Surface Water Management Plan, the MPCA Construction General Permit,
and the MS4 post-construction stormwater standards.
b. Reviews of submitted plans, will utilize a checklist to ensure accuracy (Appendix A).
Standard Operating Procedure
5
c. The City may conduct inspections of post-construction stormwater BMPs once during each MS4
permit cycle to determine if the system(s) are functioning as designed and permitted.
d. Once during each MS4 permit cycle request applicants to fill out and return the questionnaire.
e. If any applicants do not return their questionnaire to the City, the City may inspect the post-
construction stormwater BMP on behalf of the applicant and bill the property owner for
administrative costs incurred.
f. Notify all owners of post-construction stormwater BMPs with deficiencies and require repair
within 4 months.
g. If any owners of post-construction stormwater BMPs with deficiencies are not repaired within 4
months of notification, the City may complete the repairs and bill the property owner for such
repairs.
Training
The City of Medina shall ensure that individuals receive training commensurate with their responsibilities
as they relate to the Post- Construction Stormwater Management program. The City shall ensure that
previously trained individuals attend a refresher training every three (3) calendar years following the
initial training.
Standard Operating Procedure
6
5.2 LONG-TERM OPERATION AND MAINTENANCE
Activities and Definition
All BMPs installed for the purpose of meeting the post-construction stormwater management
standard are required to develop maintenance agreements and maintenance plans that are recorded on
the deed of the property. After the maintenance agreement is executed, the City is required to ensure
the conditions for post-construction stormwater management continue to be met.
Preparation
Develop a reporting mechanism (i.e. worksheet, questionnaire, etc.) for owners of post-
construction stormwater BMPs.
Process
a. The City of Medina may conduct inspections of post-construction stormwater BMPs once
during each MS4 permit cycle to determine if the system(s) are functioning as designed and
permitted.
b. Once during each MS4 permit cycle request applicants to fill out and return the questionnaire.
c. If any applicants do not return their questionnaire to the City, the City may inspect the
post- construction stormwater BMP on behalf of the applicant and bill the property owner
for administrative costs incurred.
d. Notify all owners of post-construction stormwater BMPs with deficiencies and require repair
within 4 months.
e. If any owners of post-construction stormwater BMPs with deficiencies are not repaired
within 4 months of notification, the City may complete the repairs and bill the property
owner for such repairs.
f. Decertify all owners of post-construction stormwater BMPs that do not return the
Standard Operating Procedure
7
questionnaire.
g. Defer all applicants that do not return their questionnaire to the watersheds for enforcement
Enforcement Response Procedure
The City of Medina shall maintain written ERPs to compel compliance with the regulatory
mechanism(s) required in Section 20. The City shall specify the Public Works Director as the position
title of responsible person(s) for conducting enforcement along with the timeframe. The following
enforcement tools include:
a. Verbal warning
b. Notice of violation
c. Stop work order
At a minimum, the written ERPs shall include:
a. A description of enforcement tools available to the permittee and guidelines for the use of each
tool; and
b. The name or position title of responsible person(s) for conducting enforcement
Documentation
The City shall maintain a written or mapped inventory of structural stormwater BMPs not owned or
operated by the permittee that meet all of the following criteria:
a. The structural stormwater BMP includes an executed legal mechanism(s) between the permittee
and owners responsible for the long-term maintenance, as required in item 20.15;
b. The structural stormwater BMP was implemented on or after August 1, 2013.
Documentation as related to training:
a. Document general subject matter covered
b. Document the names and departments of individuals in attendance
c. The date of each event
d. Keep logs of all maintenance agreements that are filed with the City, along with their BMP
locations.
Documentation as related to the City’s site review process:
a. The water quality volume that will be treated through volume reduction practices
compared to the total water quality volume required to be treated.
b. Documentation associated with off-site treatment projects the City authorizes, including
rationale to support the location of permanent stormwater treatment projects in accordance
with items 20.10 and 20.11.
Standard Operating Procedure
8
c. Obtain as-built plans for all public and private post-construction stormwater BMPs that are
installed within the City.
d. Obtain a long-term maintenance agreement for private structural stormwater BMPs.
e. Obtain a site plan review procedure to ensure the post-construction stormwater
management is in accordance with the regulatory mechanism.
f. Keep copies of returned questionnaires and inspection reports on file for at least three years,
should the City be required to perform maintenance for non- compliance.
Documentation as related to the enforcement conducted pursuant to the City’s ERPs:
a. The name of the person responsible for violating the terms and conditions of the City’s regulatory
mechanism(s)
b. The date(s) and location(s) of the observed violation(s)
c. A description of the violation(s) Corrective action(s) issued
d. Referrals to other regulatory organizations
e. The date(s) violation(s) are resolved
The City of Medina shall conduct an annual assessment of the Post-Construction Stormwater
Management program to evaluate program compliance, the status of achieving the measurable
requirements (activities that must be documented or tracked as applicable to the MCM (e.g., inventory,
trainings, site plan reviews, inspections, enforcement, etc.)) in Section 20 of the MS4 General Permit
and determine how the program might be improved. The City shall perform the annual assessment prior
to completion of each annual report and document any modifications made to the program because of
the annual assessment.
Conduct Site Review:
· Aerial Photos and Topographic Maps
· County Soil Surveys and other Soil Information as Available
· County Geologic Atlas
· Local Groundwater Levels
· DWSMA and Wellhead Protection Maps
· FEMA and Local Floodplain Maps
· Soil Borings and Site Survey
· MPCA Listing of Potentially Contaminated Sites
· Phase 1 and 2 Environmental Site Assessments
· TMDLs and Local Water Quality Standards
· Wetland Delineations, MNRAM Assessments, and Wetland Classifications
· Proposed Conditions, Conceptual/Preliminary Site Design
· Local zoning and land use requirements/ordinances, including stormwater rate control requirements
· Communication with Local Landowners, LGU, or Others Knowledgeable about the Site
· Site Inspection
Is shallow groundwater
or shallow bedrock
present on site?
Are there very low
infiltrating soils (<0.2
inches per hour)?
Is BMP relocation onsite to
avoid shallow groundwater
and bedrock feasible?
Conduct detailed site
investigation (i.e., borings,
excavations, consultation with a
professional geologist).
Is there >3 feet of soil depth
(> 10 feet is preferred) from bottom
of BMP to bedrock and
groundwater?
Can BMP be
raised?
Can BMP be sized to
drain dry within 48 hours
(24 hours in locations that are
tributary to trout
streams)?
Define Performance Goal
New and redevelopment projects: Retain on site a volume of 1.1" from
impervious surfaces
Linear projects: Retain on site the larger of 1.1" from all new, or .55" from
all new and fully reconstructed (D) impervious surfaces.
Is the site located in a
DWSMA, wellhead protection
area, or within 200 feet of a
drinking well?
Yes
Are there existing or
proposed structures or
infrastructure (e.g., rate control
BMPs, utilities, buildings,
roadway, easements) that
make the Performance
Goal not
feasible? (G)
No
Is BMP relocation
feasable?Yes
No
Is FTO Alternative No.
1 feasible?No No
No
Raise BMP enough to ensure 3 feet (preferably 10
feet) of soil between bottom of BMP and top of
bedrock and groundwater.
Yes
Is there presence of
contaminated soils and/
or groundwater, or
hotspot runoff? (H)
No
Can hotspot or
contamination be isolated
or remediated to mitigate
risk of increased
contamination?
Yes
No Yes
Is BMP relocation onsite
to a higher-infiltrating
location feasible?
Yes No Provide soil boring or infiltration test results
documenting low-infiltrating soils.
Is FTO Alternative No. 1
(lower volume control standard)
feasible, allowing the BMP to drain
within 48 hours (24 hours in
locations that are tributary to
trout streams)?
No No
Are there very high
infiltrating soils (>8 inches
per hour)? (E)
No
Yes Yes
Yes
Is BMP relocation onsite
to a lower-infiltrating
location feasible?
Can subgrade be
modified to slow the rate of
infiltration to less than 8
inches per hour?
Yes No
No Yes Yes
MIDS DESIGN SEQUENCE FLOW CHART version 6.18.13
· Select FTO Alternative No. 1
· Provide soil boring or infiltration test results documenting high-infiltrating soils.
Is the project linear?
Are there
zoning and land use
requirements (density,
parking, setbacks, etc.) that
make the Performance
Goal not feasible?
(G)
No
Is BMP relocation
feasible?
Is FTO Alternative
No. 1 feasible?
Select FTO #3. Provide site survey, maps,
regulations, and/or cost estimates documenting
that meeting the original performance goal or FTO
alternatives is not feasible in addition to other
documentation as required by LGU.
NoYesNo Is FTO Alternative
No. 2 feasible?
Can a local unit of government
provide a higher level of engineering
review to ensure a functioning system
that prevents adverse impacts to
groundwater?
Is FTO Alternative No. 2
feasible?
Are active karst areas
within 1000 feet up-
gradiant or 100 feet
downgradiant of the BMP
location?
No
Yes No
Are there adverse surface
water hydrologic impacts from
infiltration practices (e.g.,
impacting perched
wetland)?
Can the BMP be
relocated onsite to avoid
adverse hydrologic
impacts?
Yes
Is BMP relocation onsite
to a location without karst
feasible?
Yes No
Would BMPs
accommodating FTO
Alternative #1 avoid
adverse hydrologic
impacts?Yes
No
MIDS performance
goal does not apply
Does the project
create one acre or
more of new and/or fully
reconstructed (D) impervious
surfaces?
No
Is FTO
Alternative No. 2
feasible?
Yes
Yes
No
No
No
Complete Design Using Performance Goal
(As modified by FTO Alternatives, if applicable)
No
Yes Yes
No
No
· Select FTO Alternative No. 2
· No infiltration practices allowed
· Explore non-infiltration volume reduction
practices
· Provide soil boring or infiltration test
results documenting low infiltration rates.
· Select FTO Alternative No. 2
· No infiltration practices allowed
· Explore non-infiltration volume reduction practices
· Provide soil boring or infiltration test results
documenting high-infiltrating soils.
· Select FTO Alternative No. 2
· Maximize infiltration BMPs to treat up to the 0.55 inch goal, if possible.
· Explore non-infiltration volume reduction practices
· Provide report documenting potential hydrologic impacts from infiltration on the
site, prepared by registered engineer, hydrologist, or wetlands specialist.
· Select FTO Alternative No. 1
· Maximize infiltration BMPs to treat more than 0.55 inch goal, if possible.
· Provide report documenting potential hydrologic impacts from infiltration on the
site, prepared by registered engineer, hydrologist, or wetlands specialist.
· Select Flexible Treatment Option (FTO) Alternative No. 2
· No infiltration practices allowed
· Explore non-infiltration volume reduction practices
· Provide Phase I or II ESAs, or other documentation of potential
contamination or hotspot runoff
· Provide documentation of extent of contamination and remediation
alternatives considered
· Select Flexible Treatment Option (FTO) Alternative No. 2
· No infiltration practices allowed
· Explore non-infiltration volume reduction practices
· Provide soil borings or report from a professional geologist or
geotechnical engineer.
· Select Flexible Treatment Option (FTO) Alternative No. 2
· No infiltration practices allowed
· Explore non-infiltration volume reduction practices
· Provide soil borings or report from a professional geologist or
geotechnical engineer.
· Select Flexible Treatment Option (FTO) Alternative No. 2
· Provide regulations, and/or cost estimates documenting
infeasibility of meeting the original Performance Goal
· Select Flexible Treatment Option (FTO) Alternative No. 1
· Provide regulations, and/or cost estimates documenting
infeasibility of meeting the original Performance Goal
· Select Flexible Treatment Option (FTO) Alternative No. 2
· No infiltration practices allowed
· Explore non-infiltration volume reduction practices
· Provide DWSMA or well location map
· Select Flexible Treatment
Option (FTO) Alternative No. 1
· Provide regulations, and/or cost
estimates documenting
infeasibility of meeting the
original Performance Goal
· Select Flexible Treatment Option
(FTO) Alternative No. 2
· Provide regulations, and/or cost
estimates documenting
infeasibility of meeting the
original Performance Goal.
· Select Flexible Treatment Option (FTO) Alternative No. 2
· Provide documentation of offsite run on to project area
· Provide documentation of lack of right-of-way.
Yes
No
Are there restraints
due to lack of available
ROW, off site drainage
and/or rate control
requirements? (F)
Yes Yes
No
NoNo
Yes
Select FTO #3. Provide site survey, maps, regulations, and/or
cost estimates documenting that meeting the original
performance goal or FTO alternatives is not feasible in
addition to other documentation as required by LGU.No
Yes
Yes
Yes
No
Yes
MIDS Project Flexible Treatment Options (FTO)
The Flexible Treatment Options (FTO) alternatives presented here
should be employed when the Performance Goal is not feasible and/or
allowed. The designer should document the reasons why the
Performance Goal and rejected FTO Alternatives are not feasible and/
or allowed.
FTO 1
Applicant attempts to comply with the following conditions:
1.a.Achieve at least 0.55” volume reduction goal, and
1.b.Remove 75% of the annual TP load, and
1.c.Options considered and presented shall examine the merits of
relocating project elements to address, varying soil conditions
and other constraints across the site
FTO #2
Applicant attempts to comply with the following conditions:
2.a.Achieve volume reduction to the maximum extent practicable
(as determined by the Local Authority), and
2.b.Remove 60% of the annual TP load, and
2.c.Options considered and presented shall examine the merits of
relocating project elements to address, varying soil conditions
and other constraints across the site.
FTO #3
Off-site mitigation (including banking or cash or treatment on another
project, as determined by the local authority) equivalent to the
volume reduction performance goal can be used in areas
selected in the following order of preference:
1. Locations that yield benefits to the same receiving water that
receives runoff from the original construction activity
2) Locations within the same Department of Natural Resource (DNR)
catchment area as the original construction activity
3) Locations in the next adjacent DNR catchment area up-stream
4) Locations anywhere within the local authorities jurisdiction
Notes:
A.Volume reduction techniques considered shall include infiltration,
rainwater harvesting & reuse, bioretention, permeable pavement,
tree boxes, grass swales and/or additional techniques included in
the MIDS calculator or the Minnesota Stormwater Manual.
B.Applicant shall document the flexible treatment options decision
sequence, following the order of alternatives presented here.
C.For Alternative #2, the applicant is encouraged to use BMPs that
reduce volume. Secondary preference is to employ filtration
techniques, followed by rate control BMPs.
D. Fully reconstructed impervious surfaces: Areas where impervious
surfaces have been removed down to the underlying
soils. Activities such as structure renovation, mill and overlay
projects and other pavement rehabilitation projects that do not alter
the underlying soil material beneath the structure, pavement or
activity are not considered full reconstruction. In addition, other
maintenance activities such as catch basin and pipe repair/
replacement, lighting, and pedestrian ramp improvements shall not
be considered fully reconstructed impervious surfaces. Reusing an
existing building foundation and re-roofing of an existing building
are not considered fully reconstructed.
E. Soils that infiltrate too quickly may not provide sufficient pollutant
removal before the infiltrated runoff enters groundwater.
F. A reasonable attempt must be made to obtain right-of-way during
the project planning process
G. Other, this is not an exhaustive list
Is FTO Alternative No. 2
feasible?
Select FTO #3. Provide site survey, maps, regulations, and/or
cost estimates documenting that meeting the original
performance goal or FTO alternatives is not feasible in
addition to other documentation as required by LGU.
NO
YES
Is FTO Alternative No. 2
feasible?
Select FTO #3. Provide site survey, maps, regulations, and/or
cost estimates documenting that meeting the original
performance goal or FTO alternatives is not feasible in
addition to other documentation as required by LGU.
H. Hotspots includes any portion of a facility where infiltration is
prohibited under an NPDES/SDS industrial stormwater permit issued by
the MPCA
Can a local unit of government
provide a higher level of engineering
review to ensure a functioning system
that prevents adverse impacts to
groundwater?
YES
YESYES
YES
NO
APPENDIX B
BMP MATRIX
BMP Type1 Benefits Negatives Implementation
Considerations
Examples
Better Site Design • Minimizes need
for structural
BMPs
• Preserves natural
areas
• Provides buffers
for waterbodies
• Reduces the
amount of
regulatory
compliance
• May conflict
with local
ordinances
• Is there local
buy in
(developers,
officials, etc.)?
Infiltration/Rain
Garden
• Manages
stormwater
• filters pollutants
• Wildlife habitat
• Little
maintenance
• Adds beauty
• Plants can take
2-3 years to
establish
• More
maintenance
required in
first few years
• Construct
downslope of
runoff to be
captured
• Plant in spring
or fall
• Locate at least
10 feet from
building
foundations
Filtration/Riparian
Buffer
• Increases
infiltration and
groundwater
recharge
• Improves water
quality
• Controls erosion
& sedimentation
• Provides wildlife
• Not as
effective on
steep slopes
• More difficult
to implement
than some
other practices
• Plant in spring
or fall
• Locate at least
10 feet from
building
foundations
APPENDIX B
BMP MATRIX
habitat
Permeable
Pavement
• Reduces runoff
quantity, TSS, and
TP loads, as well
as temperature of
runoff water
• Well suited to
high density
urban areas that
may not have
space for other
BMPs
• Require
regular
vacuuming to
maintain
infiltration
capabilities
• Suitable for
low volume
roads, ped only
areas, parking
stalls, etc.
• Winter sanding
may clog the
surface
material
• Should be
located at least
10 feet from
structures and
100 feet from
water supply
wells
• Surface slopes
should be at
least 1% to
provide an
alternate means
of drainage
should the
surface
pavement
become clogged
APPENDIX B
BMP MATRIX
Infiltration
Planters
• Increases
infiltration and
evapotranspiratio
n of stormwater
• Filters pollutants
• Requires little
maintenance
• Provides wildlife
habitat
• Large canopy of
native trees
maximized
benefits
• Takes many
years before
trees grow to
provide
maximum
benefit
• Regular
maintenance is
required
where invasive
plant species
exist
• Must guard
against deer
browsing and
vole damage
• Plant in spring
or fall
• Watering may
be necessary
after planting
during dry
weather (25
gallons/week)
Stormwater Reuse • Protects water
supplies by
reducing use
during peak
summer months
• Results in cost
savings by
reducing
municipal water
bill
• Mimics the
natural hydrology
of the area by
infiltrating
rainwater
• May act as a
mosquito
breeding site
• Human
exposure to
pathogens
• Cross
contamination
of potable
water supply
• No well-
defined
operation and
maintenance
plan
• Some roof
types are not
conducive since
they have the
potential to
introduce
contaminants
into the system
• Systems needs
to remain
watertight and
be located on
level ground
APPENDIX B
BMP MATRIX
Green Roofs • Double the
lifespan of
traditional roof
• Reduce the urban
heat island effect
• Can reduce flow
rate by up to
three hours and
reduce flow of
stormwater by up
to 65%
• Reduces energy
costs by insulating
the structure; less
swing in diurnal
temperatures
• Installation
costs double
that of a
traditional roof
• Significant
maintenance
obligations to
ensure
establishment
• Roofs must be
able to
structurally
support
vegetation and
growing
medium
• Quality
Installation and
leak prevention
a must
• Historic
buildings may
require special
authorization
Iron Enhanced
Sand Filters
• High pollutant
removal rates
• Use as a retrofit
for existing ponds
or other BMPs
• Can be used at
sites with
restrictions where
infiltration may
not be
appropriate or
feasible
• Disposal of
iron-sand bed
will be
required when
the iron is
consumed
• Long
inundation
periods and
dead
vegetation can
cause low
oxygen
conditions and
iron loss
• Head required
for drawdown
• Adjacent slopes
must be less
than 20% and
greater than 1%
• Depth to
bedrock and
water table
must be more
than 3 feet or
an
impermeable
liner must be
used
Source: U.S. Government Services Agency
APPENDIX B
BMP MATRIX
Stormwater Ponds • Provides flood
control by
reducing the rate
that stormwater
enters receiving
waters
• Removal of
pollutants such as
phosphorous,
total suspended
solids, and metals
through settling
of stormwater
• May reduce
channel erosion
by reducing peak
stormwater flows
to receiving
waters
• Space
requirements
could be high
since the pond
footprint
should be 1-3%
of the drainage
area
• Have the
potential for
nuisance
insects or odor
• May pose
safety
concerns
• Need to
maintain dead
storage or
permanent pool
• Pretreatment
highly
recommended
to reduce
sedimentation
and reduce
maintenance
requirements
• Soil groups A
and B may
require a liner
to maintain
dead storage
• Adjacent slopes
should be less
than 25% but
greater than
0.5%
• May not be
appropriate if
receiving
waters are
coldwater
fisheries
APPENDIX B
BMP MATRIX
Hydrodynamic
Separators
• Units are
underground,
reducing space
requirements
• Can be used as
pretreatment
devices
• Can be used in
cold climates if
installed below
the frost line
• May not meet
local standards
when used
alone
• Not very
effective for
removing
nutrients and
bacteria
• May require a
bypass if high
flows are
common or
expected
• Consider
pollutant of
concern; solids
and floatables
are removed
much more
effectively than
dissolved
pollutants
1 The list of the BMPs provided are an example of potential BMPs that could be implemented throughout the City. The sites should be evaluated using the Minnesota Stormwater Manual’s criteria for
selecting BMPs. If infiltration is not determined feasible the applicant shall demonstrate credits using the Minimal Impact Design Standards (MIDS)s Flexible Treatment Options.
2Source: U.S. General Services Administration http://www.gsa.gov/portal/content/166443
APPENDIX C
CITY OF MEDINA
COUNTY OF HENNEPIN
STATE OF MINNESOTA
STORMWATER FACILITIES MAINTENANCE AGREEMENT
WITH ACCESS RIGHTS AND COVENANTS
( Insert Project Reference Numbers )
This AGREEMENT, made and entered into this day of , 20 , for the
maintenance and repair of certain Stormwater Management Facilities is entered into between
________________________________________________________________________________
(hereinafter referred to as “OWNER”) and the City of Medina (hereinafter referred to as “CITY”)
for the benefit of the CITY, the OWNER, the successors in interest to the CITY or the OWNER,
and the public generally.
WITNESSETH
WHEREAS, the undersigned is the owner of that certain real property lying and being in the _____
Land Lot/District, ______ identified as [Tax Map/Parcel Identification Number] _______________
and being more particularly described by deed as recorded in the land records of the City of
Medina, Minnesota, Deed Book ______ Page ____, hereinafter called the "Property".
WHEREAS, the undersigned is proceeding to build on and develop the property; and has submitted
the Site Plan/Subdivision Plan known as ______________________________________________,
(Name of Plan/Development) hereinafter called the "Plan", which is expressly made a part hereof,
as approved or to be approved by the City, provides for detention of stormwater within the confines
of the property; and
WHEREAS, the City and the undersigned, its successors and assigns, including any homeowners’
association, (hereinafter the “Landowner”) agree that the health, safety, and welfare of the residents
of the City of Medina, Minnesota, requires that on-site stormwater management facilities be
constructed and maintained on the Property; and
WHEREAS, the City requires that on-site stormwater management facilities as shown on the Plan
(the “Facilities”) be constructed and adequately maintained by the Landowner.
NOW, THEREFORE, in consideration of the foregoing premises, the mutual covenants contained
herein, and the following terms and conditions, the parties hereto agree as follows:
(1) When a new drainage control facility is installed, the party having the facility installed shall
obtain a copy of the as-built plans from the City of Medina Engineering Department.
Responsible parties shall make records of the installation and of all maintenance and repair,
and shall retain the records for at least ten years. These records shall be made available to
the City of Medina’s City Engineer during Inspection of the facility and at other reasonable
times upon request of the City Engineer.
(2) The following operational maintenance activities shall be performed on all permitted
systems on a regular basis or as needed:
a) Removal of trash and debris,
b) Inspection of inlets and outlets,
c) Removal of sediments when the storage volume or conveyance capacity of the
stormwater management system is below design levels
d) Ensure systems designed for infiltration are drawing down within 48 hours, and
e) Stabilization and restoration of eroded areas.
(3) Specific operational maintenance activities are required, depending on the type of permitted
system, in addition to the practices listed in subsection (2), above.
a) Retention, swale and underdrain systems shall include provisions for:
1. Mowing and removal of grass clippings, and
2. Aeration, tilling, or replacement of topsoil as needed to restore the
percolation capability of the system. If tilling or replacement of the topsoil is
utilized, vegetation must be established on the disturbed surfaces.
b) Exfiltration systems shall include provisions for removal of sediment and debris
from pretreatment or sediment collection systems.
c) Wet detention systems shall include provisions for operational maintenance of the
littoral zone. Replanting shall be required if the percentage of vegetative cover falls
below the permitted level. It is recommended that native vegetation be maintained in
the littoral zone as part of the system's operation and maintenance plan. Undesirable
species such as cattail and exotic plants should be controlled if they become a
nuisance.
d) Dry detention systems shall include provisions for mowing and removal of grass
clippings.
(4) If the system is not functioning as designed and permitted, operational maintenance must be
performed immediately to restore the system. If operational maintenance measures are
insufficient to enable the system to meet the design and performance standards of this
chapter, the permittee must either replace the system or construct an alternative design.
(5) In the event the Landowner fails to maintain the Facilities in good working condition
acceptable to the City, the City will no longer provide credits towards a reduction in the
landowners’ stormwater utility fee. The City may enter upon the Property and take such
steps as are necessary to correct deficiencies identified in the inspection report and to charge
the costs of such repairs to the Landowner. This provision shall not be construed to allow the
City to erect any structure of permanent nature on the land of the Landowner outside of the
easement for the stormwater management facilities. It is expressly understood and agreed
that the City is under no obligation to routinely maintain or repair said facilities, and in no
event shall this Agreement be construed to impose any such obligation on the City. The
Landowner grants to the City, its authorized agents and employees, a non-exclusive,
perpetual easement over, across, under and through the Property for such purposes.
IN WITNESS THEREOF, the parties hereto acting through their duly authorized agents have
caused this Agreement to be signed, sealed and delivered:
(Insert Company/Corporation/Partnership Name) [SEAL]
_________________________________________________
By: (Type Name and Title)
The foregoing Agreement was acknowledged before me
this ____ day of ____________, 20___, by
_____________________________________
Unofficial Witness
_____________________________________
NOTARY PUBLIC
My Commission Expires: ____________
CITY OF MEDINA, MINNESOTA
ATTACHMENT 1: CITY OF MEDINA
ENGINEERING STANDARDS FOR STORM WATER
TREATMENT FACILITIES
The following are the maintenance requirements required for the proper operation of water
quality treatment structures provided by the Minnesota Stormwater Manual (MPCA):
Pond Maintenance Requirements
1. Annual inspection, maintenance reporting and certification by a professional engineer
(Provided by Owner). Information must be submitted to the City annually.
2. Excavate pond to original design capacity when one half (1/2) of the wet volume of the pond
is lost due to sediment deposition.
3. Remove floatable debris in and around the pond area including, but not limited to: oils,
gases, debris and other pollutants.
4. Maintain landscape adjacent to the facility per original design, including but not limited to:
maintenance of the buffer strip and other plant materials as per original plan design.
5. Maintenance of all erosion control measures including but not limited to: rip rap storm
sewer outlets, catch basin inlets, etc.
Water Quality Manhole Maintenance Requirements
1. Annual inspection, maintenance reporting and certification by a professional engineer
(Provided by Owner). Information must be submitted to the City annually.
2. Maintenance should be performed once the sediment or oil depth exceeds the
established requirements recommended by the manufacturer.
3. Maintenance should occur immediately after a spill takes place. Appropriate regulatory
agencies should also be notified in the event of a spill.
4. Disposal of materials shall be in accordance with local, state and federal requirements as
applicable.
Rain Garden Maintenance Requirements
1. Inlet and Overflow Spillway – Remove any sediment build-up or blockage and correct any
erosion.
2. Vegetation
a. Maintain at least 80% surface area coverage of plants approved per plan.
b. Removal of invasive plants and undesirable woody vegetation.
c. Removal of dried, dead and diseased vegetation.
d. Re-mulch void or disturbed/exposed areas.
3. Annual inspection and maintenance efforts must be documented and submitted to the City.
Filtration Basin Maintenance Requirements
1. Sweep sediment from parking lot 4 times per year
2. Ongoing and as needed:
a. Prune and weed to maintain appearance
b. Remove trash and debris
c. Maintain at least 80% surface area coverage of plants approved per plan.
d. Removal of invasive plants and undesirable woody vegetation.
e. Removal of dried, dead and diseased vegetation.
f. Re-mulch void or disturbed/exposed areas.
3. Semi-annually:
a. Remove sediment from inflow points (off-line systems)
b. Inspect aggregate filter system and clean as needed
c. Shrubs should be inspected to evaluate health. Remove dead and diseased
vegetation.
4. Annually:
a. Inspect and remove any sediment and debris build-up in pre-treatment areas
b. Inspect inflow points and bio retention surface for buildup of road sand associated
with spring melt period. Remove and replant as necessary.
5. 2 to 3 years:
a. Test pH of planting soils. If pH is below 5.2, add limestone. If pH is 7.0 to 8.0, add
iron sulfate plus sulfur.
6. Annual inspection and maintenance efforts must be documented and submitted to the City.
APPENDIX D
CITY OF MEDINA
ENGINEERING STANDARDS FOR STORM WATER
TREATMENT FACILITIES
The following are the maintenance requirements for the proper operation of water quality
treatment structures provided by the Minnesota Stormwater Manual (MPCA, November 2005)
and the Minnesota BMP Manual (Metropolitan Council, July 2001):
Pond Maintenance Requirements
1. Annual inspection, maintenance reporting and certification by a professional engineer
(Provided by Owner). Information must be submitted to the City annually.
2. Excavate pond to original design capacity when one half (1/2) of the wet volume of the pond
is lost due to sediment deposition.
3. Remove floatable debris in and around the pond area including, but not limited to: oils,
gases, debris and other pollutants.
4. Maintain landscape adjacent to the facility per original design, including but not limited to:
maintenance of the buffer strip and other plant materials as per original plan design.
5. Maintenance of all erosion control measures including but not limited to: rip rap storm
sewer outlets, catch basin inlets, etc.
Environmental Manhole Maintenance Requirements
1. Annual inspection, maintenance reporting and certification by a professional engineer
(Provided by Owner). Information must be submitted to the City annually.
2. Maintenance should be performed once the sediment or oil depth exceeds the
established requirements recommended by the manufacturer.
3. Maintenance should occur immediately after a spill takes place. Appropriate regulatory
agencies should also be notified in the event of a spill.
4. Disposal of materials shall be in accordance with local, state and federal requirements as
applicable.
Rain Garden Maintenance Requirements
1. Inlet and Overflow Spillway – Remove any sediment build-up or blockage and correct any
erosion.
2. Vegetation
a. Maintain at least 80% surface area coverage of plants approved per plan.
b. Removal of invasive plants and undesirable woody vegetation.
c. Removal of dried, dead and diseased vegetation.
d. Re-mulch void or disturbed/exposed areas.
3. Annual inspection and maintenance efforts must be documented and submitted to the City.
Filtration Basin Maintenance Requirements
1. Sweep sediment from parking lot 4 times per year
2. Ongoing and as needed:
a. Prune and weed to maintain appearance
b. Remove trash and debris
c. Maintain at least 80% surface area coverage of plants approved per plan.
d. Removal of invasive plants and undesirable woody vegetation.
e. Removal of dried, dead and diseased vegetation.
f. Re-mulch void or disturbed/exposed areas.
3. Semi-annually:
a. Remove sediment from inflow points (off-line systems)
b. Inspect aggregate filter system and clean as needed
c. Shrubs should be inspected to evaluate health. Remove dead and diseased
vegetation.
4. Annually:
a. Inspect and remove any sediment and debris build-up in pre-treatment areas
b. Inspect inflow points and bioretention surface for buildup of road sand associated
with spring melt period. Remove and replant as necessary.
5. 2 to 3 years:
a. Test pH of planting soils. If pH is below 5.2, add limestone. If pH is 7.0 to 8.0, add
iron sulfate plus sulfur.
6. Annual inspection and maintenance efforts must be documented and submitted to the City.
Stormwater Management Design Standards
City of Medina
July 2022
Prepared by WSB & Associates
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Stormwater Management Design Standards
City of Medina, MN
TABLE OF CONTENTS
1.DESIGN OVERVIEW ............................................................................................................. 1
2.DEFINITIONS ........................................................................................................................ 2
3.APPLICABILITY ..................................................................................................................... 6
4.SUBMITTAL REQUIRMENTS ................................................................................................ 7
5.PLAN REVIEW PROCEDURES ............................................................................................... 9
6.CONSTRUCTION SITE STORMWATER RUNOFF CONTROL ................................................ 11
7.STORMWATER MANAGEMENT DESIGN STANDARDS....................................................... 19
8.STORMWATER TREATMENT PLAN DESIGN CRITERIA ....................................................... 22
9.STORM SEWER DESIGN STANDARDS ................................................................................ 30
10.DESIGN EXAMPLES ............................................................................................................ 34
11.STORMWATER TREATMENT PRACTICE DETAIL DRAWINGS ............................................. 35
12.CONSTRUCTION SPECIFICATIONS ..................................................................................... 36
13.CHECKLISTS ....................................................................................................................... 37
Stormwater Management Design Standards
City of Medina, MN Page 1
1. DESIGN OVERVIEW
The City of Medina’s Stormwater Pollution Prevention Plan (SWPPP) identifies the goals and policies that
define the City’s stormwater management program, which are implemented via the City Code (Chapter
14) and these Engineering Design Standards. Medina’s stormwater requirements were written to meet
the City’s goals to preserve, protect, and manage its water resources as well as to meet federal, state,
and watershed stormwater regulations and to meet the following objectives:
• Minimize increases in stormwater runoff rates from any development in order to reduce
flooding, siltation and erosion and in order to maintain the integrity of stream channels,
• Minimize increases in nonpoint source pollution caused by stormwater runoff from
development which would otherwise degrade local water quality,
• Minimize the total annual volume of surface water runoff that flows from any specific site
during and following development so as not to exceed the predevelopment hydrologic
regime to the maximum extent practicable,
• Ensure that these management controls are properly maintained and pose no threat to
public safety, and
• Implement stormwater management controls to help meet current and future total
maximum daily load (TMDL) goals, to address the need to improve water quality, and to
meet objectives in the Local Surface Water Management Plan.
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City of Medina, MN Page 2
2. DEFINITIONS
For the purpose of this Design Manual, the following definitions describe the meaning of the terms used
in this Design Manual:
Applicant. A property owner or agent of a property owner who has filed an application for a
Stormwater Management Permit.
Best Management Practices (BMPs). Erosion and sediment control and water quality management
practices that are the most effective and practicable means of controlling, preventing, and minimizing
degradation of surface water, including avoidance of impacts, construction-phasing, minimizing the
length of time soil areas are exposed, prohibitions, and other management practices published by state
or designated area-wide planning agencies.
Channel. A natural or artificial watercourse with a definite bed and banks that conducts continuously or
periodically flowing water.
Commissioner. The Commissioner of the Minnesota Pollution Control Agency or the Commissioner's
designee.
Common Plan of Development or Sale. A contiguous area where multiple separate and distinct land
disturbing activities may be taking place at different times, on different schedules, but under one
proposed plan. One plan is broadly defined to include design, permit application, advertisement or
physical demarcation indicating that land-disturbing activities may occur.
Construction Activity. For this permit, construction activity includes construction activity as defined in
40 C.F.R. part 122.26(b)(14)(x) and small construction activity as defined in 40 C.F.R. part 122.26(b)(15).
This includes a disturbance to the land that results in a change in the topography, existing soil cover
(both vegetative and non-vegetative), or the existing soil topography that may result in accelerated
storm water runoff, leading to soil erosion and movement of sediment into surface waters or drainage
systems. Examples of construction activity may include clearing, grading, filling and excavating.
Construction activity includes the disturbance of less than one acre of total land area that is a part of a
larger common plan of development or sale if the larger common plan will ultimately disturb one (1)
acre or more.
Dewatering. The removal of water for construction activity. It can be a discharge of appropriated
surface or groundwater to dry and/or solidify a construction site. It may require Minnesota Department
of Natural Resources permits to be appropriated and if contaminated may require other MPCA permits
to be discharged.
Energy Dissipation. Methods employed at pipe outlets to prevent erosion. Examples include, but are
not limited to: concrete aprons, riprap, splash pads, and gabions that are designed to prevent erosion.
Erosion and Sediment Control (ESC) Plan. Otherwise known as a stormwater pollution prevention plan
(SWPPP) which is a set of plans prepared by or under the direction of a licensed professional engineer or
certified contractor indicating the specific measures and sequencing to be used to control the sediment
and erosion on a project site during and after construction.
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City of Medina, MN Page 3
Erosion Prevention. Measures employed to prevent erosion including but not limited to: soil
stabilization practices, limited grading, mulch, temporary or permanent cover, and construction
phasing.
Final Stabilization. The applicant must ensure Final Stabilization of the site after the completion of
construction activities and prior to the termination of the permit. Final Stabilization is not complete until
all requirement in accordance to the definition in Section 6.7 are complete that are intended to prevent
discharge of pollutants associated with stormwater discharges from the project.
Impaired or Special Waters. Waters identified as impaired under section 303 (d) of the federal Clean
Water Act for phosphorus (nutrient eutrophication biological indicators), turbidity, dissolved oxygen or
aquatic biota (fish bioassessment, aquatic plant bioassessment and aquatic macroinvertebrate
bioassessment).
Impervious Area. Those surfaces that cannot effectively infiltrate rainfall (e.g., building rooftops,
pavement, sidewalks, gravel, driveways, swimming pools, etc.).
Land Disturbance Activity. Any activity that changes the volume or peak discharge rate of stormwater
runoff from the land surface. This may include the grading, digging, cutting, scraping, or excavating of
soil, placement of fill materials, paving, construction, substantial removal of vegetation, or any activity
that bares soil or rock or involves the diversion or piping of any natural or fabricated watercourse.
Linear Project. Construction or reconstruction of roads, trails, sidewalks, and rail lines that are not part
of a common plan of development or sale. Mill, overlay and other resurfacing projects are not
considered to be reconstruction.
Low Impact Development (LID). An approach to land development (or re-development) that works with
nature to manage stormwater as close to its source as possible.
Maintenance Agreement. A document recorded against the property which provides for long-term
maintenance of stormwater treatment practices.
Minimum Impact Design Standards (MIDS). Design requirements such that the rate and volume control
and water quality standards of predevelopment stormwater reaching receiving waters is unchanged
compared to the runoff from developed land.
National Pollutant Discharge Elimination System (NPDES). The program for issuing, modifying,
revoking, reissuing, terminating, monitoring, and enforcing permits under the Clean Water Act (Sections
301, 318, 402, and 405) and United States Code of Federal Regulations Title 33, Sections 1317, 1328,
1342, and 1345.
New Development. Nonlinear developments that create more than one acre of new impervious surface
on sites that are not classified as redevelopment.
Nonpoint Source Pollution. Pollution from any source other than from any discernible, confined, and
discrete conveyances, and shall include but not be limited to, pollutants from agricultural, silvicultural,
mining, construction, subsurface disposal and urban runoff sources.
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City of Medina, MN Page 4
Notice of Termination (NOT). Notice to terminate coverage under the NPDES permit after construction
is complete, the site has undergone final stabilization, and maintenance agreements for all permanent
facilities have been established, in accordance with all applicable conditions of this permit.
Off-Site Facility. A stormwater management measure located outside the subject property boundary.
Permanent Cover. Shall mean final stabilization. Examples include grass, gravel, asphalt, and concrete.
Permittee. A person or persons, firm, or governmental agency or other institution that signs the
application for a valid permit and is responsible for compliance with the terms and conditions of this
permit.
Responsible Party. The entity which will be responsible for ownership and maintenance of Stormwater
Treatment Practices.
Sediment Control. Methods employed to prevent sediment from leaving the site, including filter logs,
silt fences, sediment traps, filter berms, earth dikes, drainage swales, check dams, subsurface drains,
pipe slope drains, storm drain inlet protection, and temporary or permanent sedimentation basins.
Stabilized. The exposed ground surface has been covered by appropriate materials such as mulch,
staked sod, riprap, wood fiber blanket, or other material that prevents erosion from occurring. Grass
seeding is not stabilization.
Stop Work Order. An order which requires that all construction activity on a site be stopped.
Stormwater. Is defined under Minn. R. 7077.0105, subp. 41(b), and includes precipitation runoff, storm
water runoff, snow melt runoff, and any other surface runoff and drainage.
Stormwater Management. The use of structural or non-structural practices that are design to reduce
stormwater runoff pollutant loads, discharge volumes, and/or peak discharge rates.
Stormwater Management Plan (SWMP). A set of drawings or other documents submitted by a person
as a prerequisite to obtaining stormwater management approval, which contains all of the required
information and specifications pertaining to Stormwater Management.
Stormwater Treatment Practices (STPs). Measures, either structural or nonstructural, that are
determined to be the most effective and practical means of preventing or reducing point source or
nonpoint-source pollution inputs to stormwater runoff and waterbodies.
Surface Water or Waters. All streams, lakes, ponds, marshes, wetlands, reservoirs, springs, rivers,
drainage systems, waterways, watercourses, and irrigation systems whether natural or artificial, public
or private.
Redevelopment. Nonlinear projects with 1 acre or greater of impervious at the beginning of
construction, and plans to reconstruct greater than 15 percent of the existing impervious surfaces.
Temporary Erosion Protection. Short term methods employed to prevent erosion. Examples of these
methods include: straw, wood fiber blanket, wood chips and erosion netting.
Water Quality Volume (WQv). The runoff storage volume needed to treat the specified phosphorus
loading as determined by these Engineering Design Standards.
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City of Medina, MN Page 5
Watercourse. A permanent or intermittent stream or other body of water, either natural or fabricated,
which gathers or carries surface water.
Waters of the State. (As defined in Minn. Stat. § 115.01, subd. 22). All streams, lakes, ponds, marshes,
watercourses, waterways, wells, springs, reservoirs, aquifers, irrigation systems, drainage systems and
all other bodies or accumulations of water, surface or underground, natural or artificial, public or
private, which are contained within, flow through, or border upon the state or any portion thereof.
Watershed. The total drainage area contributing runoff to a single point.
Wetland or Wetlands. As defined in Minn. R. 7050.0130, subp. F and includes those areas that are
inundated or saturated by surface water or groundwater at a frequency and duration sufficient to
support, and that under normal circumstances do support, a prevalence of vegetation typically adapted
for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar
areas. Constructed wetlands designed for wastewater treatment are not waters of the state. Wetlands
must have the following attributes:
• A predominance of hydric soils;
• Inundated or saturated by surface water or groundwater at a frequency and duration
sufficient to support a prevalence of hydrophytic vegetation typically adapted for life in a
saturated soil condition; and
• Under normal circumstances support a prevalence of such vegetation.
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City of Medina, MN Page 6
3. APPLICABILITY
An Erosion and Sediment Control (ESC) Plan and/or Stormwater Management Plan (SWMP) may be
required, based on the criteria outlined below. These plans shall be consistent with NPDES permit
requirements, and the filing or approval requirements of other regulatory bodies. When required, these
plans shall be approved prior to the issuance of any permits.
3.1 Erosion and Sediment Control
Unless otherwise exempted by these Standards, Applicants are required to follow the Erosion
and Sediment Control requirements of Section 6 of these Standards and are encouraged to
incorporate the Stormwater Management requirements of Section 7 and 8, for all proposed land
disturbing activities within the City that meet any or all of the following:
a) Involves excavation or filling, or a combination of excavation and filling, in excess of 50
cubic yards of material; or
b) A land disturbing activity, regardless of size, that the City determines is likely to cause an
adverse impact to an environmentally sensitive area or other property, or may violate
any other erosion and sediment control standard set forth in this ordinance.
3.2 Stormwater Management
Unless otherwise exempted in these Standards, Applicants are required to develop a
Stormwater Management Plan (SWMP) that meets the requirements of Sections 7 and 8 of
these Standards, for all proposed land disturbing activities that meet any or all of the following:
a) Any land disturbing activity that may ultimately result in the addition of 1.0 acre or greater
of impervious surfaces, including smaller individual sites that are part of a common plan of
development that may be constructed at different times; or
b) Any land disturbance activity, regardless of size, that the City determines is likely to cause an
adverse impact to an environmentally sensitive area or other property.
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City of Medina, MN Page 7
4. SUBMITTAL REQUIRMENTS
Stormwater Management Plan Requirements
A stormwater management plan shall be submitted with the permit application for a project equaling or
exceeding the thresholds of Section 3. The stormwater management plan shall fully address the design
and function of the project proposal and the effects of altering the landscape relative to the direction,
rate of discharge, volume of discharge and timing of runoff.
No building permit will be approved unless it includes a Stormwater Management Plan detailing how
runoff and associated water quality impacts resulting from the development will be controlled or
managed. This plan must indicate whether stormwater will be managed on-site or off-site and, if on-
site, the general location and type of practices.
The Stormwater Management Plan must be signed by a licensed professional engineer in the State of
Minnesota, who will verify that the design of all stormwater management practices meet the submittal
requirements outlined in the Submittal Checklist found in Appendix A. No building permit, grading
permit, sediment control permit, or subdivision approval shall be issued until a satisfactory final
Stormwater Management Plan, or a waiver thereof, shall have undergone a review and been approved
by the City after determining that the plan waiver is consistent with the requirements of this manual.
Record drawings are required for all projects that impact wetlands and/or the floodplain, require water
quality ponding, have significant grade changes, and/or have other unusual circumstances. Record
drawings must be certified by a professional land surveyor or civil engineer. (Record drawings should not
include temporary erosion control measures.)
Stormwater Management Conceptual Plan Requirements
A stormwater management concept plan submittal is required. A concept plan identifies basic site
information, locations of proposed development features, and preliminary locations and sizing of STPs.
The City prefers to provide water quality improvement through the use of regional storm water
treatment systems versus site-by-site systems. If regional systems are not available, on-site treatment
may be required. The concept submittal has a greater chance of identifying major obstacles and can
facilitate alternative stormwater management arrangements in a timely fashion and at the onset of
project planning. If a concept plan is submitted for review, it should include sufficient information (e.g.,
maps, basic hydrologic and water quality calculations etc.) to evaluate the environmental characteristics
of the project site. This information should show the potential impacts of all proposed development of
the site, both present and future, on the water resources, and show the effectiveness and acceptability
of the measures proposed for managing stormwater generated at the project site. The intent of this
conceptual planning process is to determine the type of stormwater management of stormwater runoff
form future development, and to identify major issues prior to completing final plans. The concept plan
is less time consuming and more efficient to evaluate proposed development plans with this step of the
review process. The following information shall be included with this concept plan:
1. A map (or maps) indicating the location of existing and proposed buildings, roads, parking
areas, utilities, structural stormwater management and sediment control facilities. The
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City of Medina, MN Page 8
map(s) will also clearly show proposed land use with tabulation of the percentage of surface
area to be adapted to various uses; drainage patterns; locations of utilities, roads and
easements; the limits of clearing and grading; a written description of the site plan and
justification of proposed changes in natural conditions may be required.
2. Sufficient calculations to show that the proposed stormwater management measures a
capable of controlling runoff from the site in compliance with this Stormwater Design
Manual.
3. A written or graphic inventory of the natural resources at the site and surrounding area as it
exists prior to the commencement of the project and a description of the watershed and its
relation to the project site. This description should include a discussion of solid conditions,
forest cover, topography, wetlands, and other native vegetative areas on the site. Particular
attention should be paid to environmentally sensitive features that provide particular
opportunities or constraints for development.
4. A brief written description of the required maintenance burden for he proposed stormwater
management facility.
The final plan provides more detailed design information for the proposed STPs, and includes much
more detail in terms of hydrologic conditions and site features.
For redevelopment, an applicant should include within a concept plan measures for controlling existing
stormwater runoff discharges and water quality from the site in accordance with the standards of this
Manual. After review of the concept plan and modifications are made to that plan as deemed necessary
by the City, a final Stormwater Management Plan may be submitted for approval.
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City of Medina, MN Page 9
5. PLAN REVIEW PROCEDURES
The general review process, from the submittal of the concept and final plans to the issuance of the
Stormwater Management Plan and/or Erosion and Sediment Control Plan approval, is summarized in the
following seven steps:
1. Determine what stormwater management provisions apply (stormwater management,
erosion control, buffers, floodplain management).
2. What permits, or approvals, are required for the project site, and what waivers and/or
exemptions are applicable (COE, DNR, MPCA, Watershed, WCA, etc.)
3. Are the selected practices appropriate for this site?
4. Are the practices designed to meet the minimum performance criteria?
5. Does the plan meet other resource protection requirements as specified in the City of
Medina’s Code?
6. Are provisions for long-term maintenance adequate, including access and methods for
maintenance defined?
Any changes to the approved plan must be submitted to the City for review and approval before work
can commence.
No development, utility or street construction will be allowed and no building permits will be issued
unless the development is in full compliance with the requirements of these Standards.
If the City determines that the Stormwater Management Plans and/or Erosion and Sediment Control
Plan meets the requirements of these standards, the City shall issue a permit valid for a specified period
of time that authorizes the land disturbance activity contingent on the implementation and completion
of this plan.
If the City determines that the Stormwater Management Plan and/or Erosion and Sediment Control Plan
does not meet the requirements of these Standards, the City shall not issue a permit for the land
disturbance activity. This plan must be resubmitted for approval before the land disturbance activity
begins. All land use and building permits shall be suspended until the developer has an authorized
permit.
Modification of Plan – The applicant must amend the ESC Plan or SWMP as necessary to correct
problems identified or address situations whenever:
1. A change in design, construction, operation, maintenance, weather, or seasonal conditions
that has a significant effect on the discharge or pollutants to surface waters or underground
waters; or
2. Inspections or investigations indicate the plans are not effective in eliminating or
significantly minimizing the discharge or pollutants to surface waters or underground waters
or that the discharges are causing water quality degradation; or
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City of Medina, MN Page 10
3. The plan is not achieving the general objectives of minimizing pollutants in stormwater
discharges associated with construction activity; or
4. The plan is not consistent with the terms and conditions of these standards.
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City of Medina, MN Page 11
6. CONSTRUCTION SITE STORMWATER RUNOFF CONTROL
6.1 Erosion Control
1. The Permittee must plan for and implement appropriate construction phasing vegetative
buffer strips, horizontal slope grading, and other construction practices to minimize erosion.
All areas not to be disturbed shall be marked (e.g. with flags, stakes, signs, silt fence etc.) on
the project site before any work begins.
2. All exposed soil areas must be stabilized as soon as possible to limit soil erosion but in no
case later than 14 days after the construction activity in that portion of the site has
temporarily or permanently ceased and no later than seven (7) days after construction
activity in that portion of the site has temporarily or permanently ceased when discharge
points on the project is within one mile of a special or impaired water and flows to that
special or impaired water.
3. Additional BMPs together with enhanced runoff controls are required for discharges to
special waters and impaired waters. The BMPs identified for each special or impaired water
are required for those areas of the project draining to a discharge point on the project that
is within one mile of a special or impaired water and flows to that water. The additional
BMPs are identified in Appendix A of the NPDES Construction General Permit.
4. The permittee must stabilize the normal wetted perimeter of any temporary or permanent
drainage ditch or swale that drains water from any portion of the construction site, or
diverts water around the site, within 200 lineal feet from the property edge, or from the
point of discharge into any surface water. Stabilization of the last 200 lineal feet must be
completed within 24-hours after connecting to a surface water or property edge.
5. Pipe outlet must have temporary or permanent energy dissipation before connecting to
surface water.
6. When possible, all slopes must be graded in such a fashion so that tracking marks made
from heavy equipment are perpendicular to the slope.
7. All areas disturbed during construction must be restored as detailed in these requirements.
The type of permanent restoration shall be clearly shown on the plans including but not
limited to sod, seed, impervious cover and structures. A minimum of 6 inches of topsoil
must be installed prior to permanent restoration. Areas in which the top soil has been
placed and finish graded or areas that have been disturbed and other grading or site
building construction operations are not actively underway must be temporary or
permanently restored as set forth in the following requirements.
a) Areas with slopes that area less than 3:1 must be seeded and mulched within 14 days of
the area not being actively worked.
b) Areas with slopes that area greater or equal to 3:1 must be seeded and erosion control
blanket placed within 14 days of the area not being actively worked.
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City of Medina, MN Page 12
c) All seeded area must be either mulched and disc anchored, hydro- mulched, or covered
by erosion control blanket to reduced erosion and protects the seed. Temporary or
permanent mulch must be disc anchored and applied at a uniform rate of 2 tons per
acre and have 90% coverage.
d) If the disturbed area will be re-disturbed within a six-month period, temporary
vegetative cover shall be required consisting of an approved seed mixture and
application rate.
e) If the disturbed area will not be re-disturbed within a six-month period, permanent
vegetative cover shall be required consisting of an approved seed mixture and
application rate.
f) All areas that will not have maintenance done such as mowing as part of the final design
shall be permanently restored using an approved seed mixture and application rate.
g) Restoration of disturbed wetland areas shall be accomplished using an approved seed
mixture and application rate.
8. All erosion control measures must be maintained for the duration of the project until final
stabilization has been achieved. If construction operations or natural events damage or
interfere with any erosion control measures, they shall be restored to serve their intended
function.
9. Additional erosion control measures shall be added as necessary to effectively protect the
natural resources of the City. The temporary and permanent erosion control plans shall be
revised as needed based on current site conditions and to comply with all applicable
requirements
6.2 Sediment Control Practices
1. Sediment control practices must be established on all down gradient perimeters before any
upgradient land disturbing activities begin. These practices must remain in place until final
stabilization has been achieved.
2. If down gradient treatment system is overloaded additional up gradient sediment control
practices must be installed to eliminate overloading. The SWPPP must be amended to
identify the additional practices.
3. All storm drain inlets must be protected by approved BMPs during construction until all
potential sources for discharge have been stabilized. These devices must be maintained
until final stabilization is achieved. Inlet protection may be removed if a specific safety
concern (street flooding/freezing) has been identified.
4. Temporary stockpiles must have silt fence or other effective sediment controls on the down
gradient side of the stockpile and shall not be placed at least 25 feet from any road,
wetland, protected water, drainage channel, or stormwater inlets. Stockpile left for more
than 14 days must be stabilized with mulch, vegetation, tarps or other approved means.
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City of Medina, MN Page 13
5. Vehicle tracking of sediment from project shall be minimized by approved BMPs. These
shall be installed and maintained at the City approved entrances. Individual lots shall each
be required to install and maintained entrances throughout the construction building until a
paved driveway is install.
6. Sediment that has washed or tracked from site by motor vehicles or equipment shall be
cleaned from paved surfaces throughout the duration of construction.
7. Silt fence or other approved sediment control devices must be installed in all areas as shown
on the SWPPP.
8. Silt fence or other approved sediment control devices shall be required along the entire curb
line, except for approved opening where construction entrance will be installed or drainage
flows away from curb. This device must be maintained until final stabilization is achieved.
Ditch checks shall be required in ditch bottoms. Spacing for the check must be as
followed:[Height in feet (of the sediment device used)] X 100 / Slope Gradient
9. Dust control measures, such as application of water must be performed periodically due to
weather, construction activity, and/or as directed by the City.
10. Flows from diversion channels or pipes (temporary or permanent) must be routed to
sedimentation basins or appropriate energy dissipaters to prevent the transport of sediment
to outflow or lateral conveyors and to prevent erosion and sediment buildup when runoff
flows into the conveyors.
11. A concrete washout shall be installed on projects that require the use of concrete. All liquid
and solid wastes generated by concrete washout operations must be contained in a leak-
proof containment facility or impermeable liner. A sign must be installed adjacent to each
washout facility to inform operators to utilize the proper facilities.
12. All sediment control measures shall be used and maintained for the duration of the project
until final. If construction operations or natural events damage or interfere with any erosion
control measures, they must be restored to serve their intended function.
13. Additional sediment control measures shall be added as necessary to effectively protect the
natural resources of the City. The temporary and permanent erosion control plans shall be
revised as needed based on current site conditions and to comply with all applicable
requirements.
14. Restrict clearing and grading adjacent to an existing wetland boundary to provide for a
protective buffer strip of natural vegetation as per Section 8.
6.3 Temporary Sediment Basins
A temporary sediment basin (or permanent) shall be provided when ten (10) or more acres of
disturbed soil drain to a common location prior to the runoff leaving the site or entering surface
waters. The Permittee is also encouraged, but not required to install temporary sediment
basins in areas with steep slope or highly erodible soils even if the area is less than ten (10) acres
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City of Medina, MN Page 14
and it drains to one common area. The basins shall be designed and constructed according to
the following requirements:
1. The basins must provide storage below the outlet pipe for a calculated volume of runoff
from a 2-year, 24-hour storm from each acre drained to the basin, except that in no case
shall the basin provide less than 1,800 cubic feet of storage below the outlet pipe from each
acre drained to the basin.
2. Where no such calculation has been performed, a temporary (or permanent) sediment basin
providing 3,600 cubic feet of storage below the outlet pipe per acre drained to the basin
shall be provided where attainable until final stabilization of the site.
3. Temporary basin outlets will be designed to prevent short-circuiting and the discharge of
floating debris. The basin must be designed with the ability to allow complete basin
drawdown (e.g., perforated riser pipe wrapped with filter fabric and covered with crushed
gravel, pumps or other means) for maintenance activities, and provide a stabilized
emergency overflow to prevent failure of pond integrity. Energy dissipation must be
provided for the basin outlet.
4. Temporary (or permanent) basins must be constructed and made operational concurrent
with the start of soil disturbance that is up gradient of the area and contributes runoff to the
pond.
5. Where the temporary sediment basin is not attainable due to site limitations, equivalent
sediment controls such as smaller sediment basins, and/or sediment traps, silt fences,
vegetative buffer strips or any appropriate combination of measures are required for all
down slope boundaries of the construction area and for those side slope boundaries
deemed appropriate as dictated by individual site conditions. In determining whether
installing a sediment basin is attainable, the Permittee must consider public safety and may
consider factors such as site soils, slope, and available area on site. This determination must
be documented in the SWPPP.
6. The Permittee shall maintain the sedimentation basins and will remain functional until an
acceptable vegetative cover is restored to the site, resulting in a pre-development level rate
of erosion. The city will not issue building permits for lots containing sediment basins until
they have been removed or relocated based on the projects restoration progress.
7. Basins designed to be used for permanent stormwater management shall be brought back
to their original design contours prior to acceptance by the City.
6.4 Dewatering and Basin Draining
1. If water cannot be discharged into a sedimentation basin before entering a surface water it
must be treated with the appropriate BMPs, such that the discharge does not adversely
affect the receiving water or downstream landowners. The Permittee must make sure
discharge points are appropriately protected from erosion and scour. The discharge must
be dispersed over riprap, sand bags, plastic sheeting or other acceptable energy dissipation
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City of Medina, MN Page 15
measures. Adequate sediment control measures are required for discharging water that
contains suspended soils.
2. All water from dewatering or basin draining must discharge in a manner that does not cause
nuisance conditions, erosion in receiving channels, on down slope properties, or inundation
in wetlands causing significant adverse impact to wetlands.
6.5 Inspections and Maintenance
1. The Permittee shall be responsible for inspecting and maintenance of the BMPs
2. The Permittee must routinely inspect the construction project once every seven (7) days
during active construction and within 24-hours of a rainfall event of 0.5 inches or greater in
24-hours.
3. All inspections and maintenance conducted during construction must be recorded in writing
and must be retained with the SWPPP. Records of each inspection and maintenance activity
shall include:
1) Date and time of inspection.
2) Name of person(s) conducting the inspections.
3) Findings of inspections, including recommendations for corrective actions.
4) Corrective actions taken (including dates, times, and the party completing the
maintenance activities).
5) Date and amount of all rainfall events 0.5 inches or greater in 24-hours.
6) Documentation of changes made to SWPPP.
4. Parts of the construction site that have achieved final stabilization, but work continues on
other parts of the site, inspections of the stabilized areas can be reduced to once a month.
If work has been suspended due to frozen ground conditions, the required inspections and
maintenance must take place as soon as runoff occurs or prior to resuming construction,
which ever happens first.
5. All erosion and sediment BMPs shall be inspected to ensure integrity and effectiveness. All
nonfunctional BMPs shall be repaired, replaced or supplemented with a functional BMP.
The Permittee shall investigate and comply with the following inspection and maintenance
requirements.
6. All silt fences must be repaired, replaced, or supplemented when they become
nonfunctional or the sediment reaches 1/2 of the height of the fence. These repairs shall be
made within 24-hours of discovery, or as soon as field conditions allow access.
7. Temporary and permanent sedimentation basins must be drained and the sediment
removed when the depth of sediment collected in the basin reaches 1/2 the storage
volume. Drainage and removal must be completed within 72-hours of discovery, or as soon
as field conditions allow access.
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8. Surface waters, including drainage ditches and conveyance systems, must be inspected for
evidence of sediment being deposited by erosion. The Permittee shall remove all deltas and
sediment deposited in surface waters, including drainage ways, catch basins, and other
drainage systems, and restabilize the areas where sediment removal results in exposed soil.
The removal and stabilization shall take place within seven (7) days of discovery unless
precluded by legal, regulatory, or physical access constraints. The Permittee shall use all
reasonable efforts to obtain access. If precluded, removal and stabilization shall take place
within seven (7) calendar days of obtaining access. The Permittee is responsible for
contacting all local, regional, state and federal authorities and receiving any applicable
permits, prior to conducting any work.
9. Construction site vehicle exit locations shall be inspected for evidence of off-site sediment
tracking onto paved surfaces. Tracked sediment shall be removed from all off-site paved
surfaces, within 24-hours of discovery, or if applicable, within a shorter time.
10. The Permittee is responsible for the operation and maintenance of temporary and
permanent water quality management BMPs, as well as all erosion prevention and sediment
control BMPs, for the duration of the construction work at the site. The Permittee is
responsible until another Permittee has assumed control over all areas of the site that have
not been finally stabilized or the site has undergone final stabilization, and a NOT has been
submitted to the MPCA.
11. If sediment escapes the construction site, off-site accumulations of sediment shall be
removed in a manner and at a frequency sufficient to minimize off-site impacts (e.g., fugitive
sediment in streets could be washed into storm sewers by the next rain and/or pose a safety
hazard to users of public streets).
12. All infiltration areas shall be inspected to ensure that no sediment from ongoing
construction activities is reaching the infiltration area and these areas are protected from
compaction due to construction equipment driving across the infiltration area.
6.6 Pollution Management Measures/Construction Site Waste Control
1. The Permittee must implement the following pollution prevention management measures
on the site.
a) Solid Waste – Collected sediment, asphalt and concrete millings, floating debris, paper,
plastic, fabric, construction and demolition debris and other wastes must be disposed of
properly and must comply with MPCA disposal requirements.
b) Hazardous Materials such as oil, gasoline, paint and any hazardous substances must be
properly stored, including secondary containment, to prevent spills, leaks or other
discharge. Restricted access to storage areas shall be provided to prevent vandalism.
Storage and disposal of hazardous waste shall be in compliance with MPCA regulations.
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c) External washing of trucks and other construction vehicles must be limited to a defined
area of the site. Runoff shall be contained and waste properly disposed of. No engine
degreasing is allowed on site.
d) The City of Medina prohibits discharges of any material other than stormwater, and
discharges from dewatering or basin draining activities. Prohibited discharges include
but are not limited to vehicle and equipment washing, maintenance spills, wash water,
and discharges of oil and other hazardous substances.
e) The Permittee must comply with all other pollution prevention/good housekeeping
requirements of the MPCA NPDES Construction General Permit.
6.7 Final Stabilization
1. The Permittee must ensure final stabilization of the project. Final stabilization can be
achieved in one of the following ways.
2. All soil disturbing activities at the site have been completed and all soils will be stabilized by
a uniform perennial vegetative cover with a density of at least 70 percent over the entire
pervious surface area, or other equivalent means necessary to prevent soil failure under
erosive conditions and;
a) All drainage ditches, constructed to drain water from the site after construction is
complete, must be stabilized to preclude erosion; and
b) All temporary synthetic, and structural erosion prevention and sediment control BMPs
(such as silt fence) must be removed as part of the site final stabilization; and
c) The Permittee must clean out all sediment from conveyances and from temporary
sedimentation basins that are to be used as permanent water quality management
basins. Sediment must be stabilized to prevent it from washing back into the basin,
conveyances or drainage ways discharging off-site or to surface waters. The cleanout of
permanent basins must be sufficient to return the basin to design capacity.
3. For residential construction only, final stabilization has been achieved when:
a) Temporary erosion protection and down gradient perimeter control for individual lots
has been completed and the residence has been transferred to the homeowner.
b) The Permittee must distribute the MPCA “homeowner factsheet” to the homeowner so
the homeowner is informed for the need, and benefits, of final stabilization.
6.8 Training
1. The SWPPP must provide a chain of command showing who prepared the SWPPP, who is
responsible for the management of the construction site and inspections.
2. The training shall consist of a course developed by a local, state or federal agency,
professional organization, water management organization, or soil and water conservation
district and must contain information that is related to erosion prevention, sediment
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control, or permanent stormwater management and must relate to the work that you are
responsible for managing.
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7. STORMWATER MANAGEMENT DESIGN STANDARDS
7.1 Stormwater Management Plan Requirements
A Stormwater Management Plan shall detail how runoff and associated water quality impacts
resulting from the development will be controlled or managed. These plans must indicate
whether stormwater will be managed on-site or off-site and, if on-site, the general location and
type of practices.
Stormwater Management Plans will be evaluated for stormwater quantity control and
stormwater quality management. The City’s policy on stormwater management is to reduce the
impacts of development by maintaining pre-development hydrological conditions in the
following ways:
1. Decrease runoff volume
2. Decrease erosion and sedimentation
3. Decrease flow frequency, duration, and peak runoff rates
4. Increase infiltration (groundwater recharge)
5. Maintain existing flow patterns
6. Reduce time to peak flows by increasing the time of concentration to and through storm
sewers
7. Increasing storage of stormwater runoff on-site
8. Avoid channel erosion
The Stormwater Management Plan must be signed by a licensed professional civil engineer in
the State of Minnesota, who will verify that the design of all stormwater management practices
meet the submittal requirements outlined in the Submittal Checklist found within the Standard
Operating Procedures for the City’s SWPPP program. A satisfactory final Stormwater
Management Plan, or a waiver thereof, shall have undergone a review and been approved by
the City after determining that the plan or waiver is consistent with the requirements of this
manual.
All plans shall be consistent with National Pollution Discharge Elimination Permit (NPDES)
requirements, and the filing or approval requirements of relevant agencies such as Watershed
Districts, or other regulatory bodies.
The following information shall be included in the Stormwater Management Plan:
1. A map (or maps) indicating the location of existing and proposed buildings, roads, parking
areas, utilities, structural stormwater management and sediment control facilities. The
map(s) will also clearly show proposed land use with tabulation of the percentage of surface
area to be adapted to various uses; drainage patterns; locations of utilities, roads and
easements; the limits of clearing and grading; a written description of the site plan and
justification of proposed changes in natural conditions may be required.
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2. Sufficient calculations to show that the proposed stormwater management measures are
capable of controlling runoff from the site in compliance with these Engineering Design
Standards.
3. A written or graphic inventory of the natural resources at the site and surrounding area as it
exists prior to the commencement of the project and a description of the watershed and its
relation to the project site. This description should include a discussion of solid conditions,
forest cover, topography, wetlands, and other native vegetative areas on the site. Particular
attention should be paid to environmentally sensitive features that provide particular
opportunities or constraints for development.
4. A brief written description of the required maintenance burden for the proposed
stormwater management facility, and the party responsible for this maintenance.
5. The final plan shall provide detailed design information for the proposed STPs, and includes
details of hydrologic conditions and site features, measures for controlling existing
stormwater runoff discharges and water quality from the site in accordance with the
standards of this Manual.
After review of the concept plan and modifications are made to that plan as deemed necessary
by the City, a final Stormwater Management Plan may be submitted for approval.
Record drawings are required for all projects that impact wetlands and/or the floodplain,
require water quality ponding, have significant grade changes, and/or have other unusual
circumstances. Record drawings must be certified by a professional land surveyor or civil
engineer. (Record drawings should not include temporary erosion control measures.)
7.2 Guidance on Stormwater Treatment Practices (STPs)
The Stormwater Management Plan shall meet the volume control, water quality, and water
quantity requirements of these Standards and the Minnesota Stormwater Manual. Designers
are also expected to follow the Minimal Impact Design Standards (MIDS) flowchart detailed in
the Minnesota Stormwater Manual (Appendix A). Deviations from recommended guidance will
require detailed written explanation with discretion given by the City.
Final site design and choice of permanent stormwater volume reduction practices shall be based
on outcomes of the MIDS Calculator (or other model that shows the performance goal can be
met) and shall meet the performance goals in Section 8 of these design standards. The MIDS
calculator is available at http://stormwater.pca.state.mn.us/index.php/Calculator.
7.3 List of Acceptable Stormwater Treatment Practices
In the development of appropriate Stormwater Treatment Practices (STP) appropriate for the
development and redevelopment, volume control systems are foremost in importance to apply
in the design. Filtration is warranted when site conditions do not allow for an effective
infiltration facility. For flooding or rate control, detention systems are typically the preferred
practice. Low Impact Design (LID) practices are encouraged when they can be functionally
incorporated into the design. Alternative practices may be approved at the discretion of the City
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City of Medina, MN Page 21
Engineer. Alternative practices may be approved at the discretion of the City Engineer. For
projects where infiltration is not feasible the STPs proposed shall meet the performance
identified in the MIDS Flexible Treatment Options (FTO) (Appendix A).
The Minnesota Stormwater Manual identifies a number of potential STPs that can be used
during design. The following is a list of potential options that can be considered during
development and redevelopment:
Volume Control Systems:
• Infiltration trench
• Infiltration basin
• Raingarden
• Underground storage
• Reuse
• Green Roofs
• Trees/Tree Planters
Wetlands:
• Shallow wetland
• Pond/wetland systems
Filtration Systems:
• Surface sand filter
• Underground sand filter
• Perimeter sand filter
• Organic filter
• Bio retention system
• Raingarden with underdrain
• Pervious pavement with underdrain
• Underground storage with underdrain
• Tree trench
Detention Systems:
• Wet pond
• Stormwater re-use systems
• Multiple pond systems
• Extended detention basin
• Micro-pool extended detention basin
• Dry detention ponds
• Underground storage
• Other, as approved by the City of
Medina
Open Channel Systems:
• Dry swale
• Wet swale
• Grass swale
• Natural channel, or stream
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8. STORMWATER TREATMENT PLAN DESIGN CRITERIA
Proposed Stormwater Management Plans must incorporate Volume Control, Water Quality Control, and
Rate Control as the basis for stormwater management in the proposed development plan. The City of
Medina, as a permitted MS4, requires for new development projects to have a no net increase from pre-
project conditions of total volume, TSS, and TP; in addition, for redevelopment projects within the city, it
is required to have a net reduction from pre-project conditions of total volume, TSS and TP.
8.1 Volume Control Requirements
Volume control measures are required on projects to meet the water quality criteria of the
Medina’s City Code, the MS4 Permit, and NPDES Construction General Permit. Volume control
shall be required by any projects resulting in site disturbance that creates one or more acres of
new impervious surface must meet all of the stormwater volume control calculations in Section
8.2. If an applicant can demonstrate that the volume control standard has been met, then the
water quality sizing criteria shall be considered satisfied.
Volume control may be waived by the city for sites with impermeable soil, where the seasonally
high groundwater table is less than three feet, bedrock depth is less than three feet, near a
stormwater sensitive water resource, or is in an area where groundwater has a high
vulnerability for contamination. If the applicant and the city agree that infiltration is not
possible, the applicant shall design alternative stormwater runoff treatment methods meeting
the requirements as established in Section 8.2.
8.2 Volume Control Calculations
Any applicant for a permit resulting in site disturbance that creates one or more acres of new
impervious surface must meet all of the following stormwater performance goals:
1. New Development Volume Control. For new, nonlinear developments that create more than
one acre of new impervious surface on sites, stormwater runoff volumes will be controlled
and the post-construction runoff volume shall be retained on site for 1.1 inches of runoff
from all impervious surfaces on the site.
2. Redevelopment Volume Control. Nonlinear redevelopment projects on sites that create one
or more acres of new and/or fully reconstructed impervious surfaces shall capture and
retain on site 1.1 inches of runoff from the new and/or fully reconstructed impervious
surfaces.
3. Linear Development Volume Control. Linear projects on sites that create one acre or greater
of new and/or fully reconstructed impervious surfaces, shall capture and retain the larger of
the following:
o 0.55 inches of runoff from the new and fully reconstructed impervious surfaces on the
site
o 1.1 inches of runoff from the net increase in impervious area on the site
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o Mill and overlay and other resurfacing activities are not considered fully
reconstructed.
For projects where it is not feasible to meet the volume reductions requirements it will be
required to meet the water quality requirements of these engineering guidelines. Infiltration is
infeasible when:
• Where industrial facilities are not authorized to infiltrate industrial stormwater under and
NPDES/SDS Industrial Stormwater Permit issued by the MPCA.
• Where vehicle fueling and maintenance occur.
• With less than three (3) feet of separation distance from the bottom of the infiltration
system to the elevation of the seasonally saturated soils or the top of the bedrock.
• Where high levels of contaminant in soil or groundwater will be mobilized by the infiltrating
stormwater.
The use of infiltration techniques shall be restricted and subject to additional city review where
the infiltration BMP will be constructed in any of the following areas:
• Soils are predominately Hydrologic Soil Group D (clay) soils.
• Within 1,000 feet up-gradient, or 100 feet down-gradient of active karst features.
• Drinking Water Supply Management Areas are present, as defined by Minn. R. 4720.51000,
subp. 13, unless precluded by a local unit of government with an MS4 permit.
• Soil infiltration rates are more than 8.3 inches per hour unless soils are amended to flow the
infiltration rate below 8.3 inches per hour.
Where the site factors listed above limit the construction of infiltration systems, the project
proposer shall provide appropriate documentation to the City regarding the limitations. If the
City determines that infiltration is restricted or prohibited onsite, the applicant will follow the
flexible treatment options outlined in the Minimal Impact Design Standards (MIDS) sequencing
guidance.
For linear projects with lack of right-of-way, easements or other permissions from property
owners to install treatments systems that are capable of treating the total water quality volume
on site, the project must maximize treatment through other methods or combination of
methods before runoff is released to nearby surface waters. Alternative treatment options
include: grassed swales, filtration systems, smaller ponds, or grit chambers. In all circumstances,
a reasonable attempt must be made to obtain right-of-way during the project planning and all
attempts of infeasibility must be recorded
8.3 Water Quality Control
For new development, the water quality control standard shall be considered satisfied if the
volume control standard has been satisfied. In the event that it is infeasible to meet the volume
control standard due to contaminated soils, site constraints, etc., the proposed STP will need to
maintain the TSS and TP loading and for redevelopment the goal is to reduce the TSS and TP
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City of Medina, MN Page 24
loadings satisfy the water quality standards using the MIDS flexible treatment options as
outlined below in addition to the MIDS Design Sequence Flowchart (Appendix A).
MIDS Flexible Treatment Options:
Option 1:
• Applicant attempts to comply with the following conditions:
o Achieve at least 0.55-inch volume reduction goal, and
o Remove 75 percent of the annual total phosphorus load, and
o Options considered and presented shall examine the merits of relocating project
elements to address varying soil conditions and other constraints across the site
Option 2:
• Applicant attempts to comply with the following conditions:
o Achieve volume reduction to the maximum extent practicable (as determined by the
Local Authority), and
o Remove 60 percent of the annual total phosphorus load, and
o Options considered and presented shall examine the merits of relocating project
elements to address varying soil conditions and other constraints across the site.
Option 3:
• Off-site mitigation (including banking or cash or treatment on another project, as
determined by the local authority) equivalent to the volume reduction performance goal
can be used in areas selected in the following order of preference:
o Locations that yield benefits to the same receiving water that receives runoff from the
original construction activity.
o Locations within the same Department of Natural Resources (DNR) catchment area as
the original construction activity.
o Locations in the next adjacent DNR catchment area up-stream.
o Locations anywhere within the local authority's jurisdiction.
Methods for meeting the water quality requirements in the decreasing order of preference:
1. Credits and site design practices to minimize the creation of connected impervious surfaces
are used to the extent practical.
2. Underdrains to promote filtration instead of infiltration.
3. Off-site infiltration.
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4. On-site wet detention with permanent pool volume below the normal outlet that is greater
than or equal to the runoff from a 2.5 inch, 24-hour storm over the entire contributing
drainage area, assuming full development.
8.4 Infiltration/Filtration Practices
1. Sizing of filtration/infiltration practices shall be in conformance with the volume control
requirements of this manual and the Minnesota Stormwater Manual.
2. When designing an infiltration practice for volume control and water quality management,
on-site testing and detailed analysis are strongly encouraged in order to determine the
infiltration rates of the proposed infiltration facility. Documented site-specific infiltration or
hydraulic conductivity measurements (double-ring infilitrometer) completed by a licensed
soil scientist or engineer is required. In the absence of a detailed analysis, the saturated
infiltration rates listed in the Infiltration Rates for Infiltration BMPs table found on the
Minnesota Stormwater Manual shall be used. A piezometer shall be installed in order to
ascertain the level of the local groundwater table and demonstrate at least three feet of
separation between the bottom of the proposed facility and the groundwater. The soil
boring is required to go to a depth of at least five feet below the proposed bottom of the
BMP. The soils shall be classified using the Unified Soil Classification system. The least
permeable soil horizon will dictate the infiltration rate. Infiltration practices shall be
designed to infiltrate the required runoff volume within 48 hours.
3. Pretreatment, in the form of ponds, forebays, filter strips, or other approved methods, shall
be provided for all infiltration areas. Pretreatment upstream of volume management
practices is a key element in the long-term viability of infiltration areas. The level of
pretreatment varies largely depending on the BMP and drainage area of the watershed, City
staff, and Minnesota Stormwater Manual recommendations shall be utilized for determining
the appropriate level of pretreatment on a case-by-case basis.
4. The infiltration practice shall not be used within fifty feet of a municipal, community or
private well, unless specifically allowed by an approved wellhead protection plan.
5. Vegetation of infiltration/filtration practices shall be as shown in the City of Medina’s
Standard Details. A plan for management for vegetation shall be included in the ESC Plan.
6. If soils are unsuitable for infiltration, then filtration may be used with drain tile, provided in
accordance with the City of Medina’s Standard Details.
7. Subgrade soils for infiltration/filtration practices shall be as presented in the City of
Medina’s Standard Details. Assume a 40% void ratio for clean washed rock and 20% for
construction sand for the purposes of volume calculations.
8. Rock storage beds shall be constructed using crushed angular granite that has been
thoroughly washed to remove all fine particles that could result in clogging of the system.
9. For infiltration benches adjacent to ponds, benches shall have slopes no steeper than 5:1
over the proposed infiltration zone. A slope of 10:1 is preferred. The Minnesota
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City of Medina, MN Page 26
Stormwater Manual cites concerns with locating infiltration features immediately adjacent
to ponds. To address this, benches shall be located to maintain hydraulic separation from
the saturated zone of the pond in order to minimize the loss of infiltration potential over
time.
8.5 Rate Control
1. A hydrograph method based on sound hydrologic theory as approved by the City engineer
will be used to analyze runoff for the development design or analysis of flows and water
levels.
2. At a minimum, detention basins should maintain existing flow rates for the 2, 10, and 100-
year 24-hour rainfalls in accordance to the Atlas14 data as shown in the table below:
Event Rainfall/Snowmelt Depth (inches)
2-year, 24 hour 2.87
10-year, 24 hour 4.28
100-year, 24 hour 7.30
100-year, 10-day snowmelt 10.20
3. Detention basins shall be designed with capacity for the critical 100-year event, which is
defined as the 100-year event that produces the highest water level among a 24-hour
rainfall event or the 10-day, 10.20-inch snowmelt runoff event.
4. The maximum duration for rainfall critical event analysis shall be 24-hours except in cases
where basins are landlocked, where back to back 24-hour events and the 10-day 10.20-inch
snowmelt runoff event shall also be used. In all cases a hydrograph method of analysis
should be used. For the 24-hour rainfall event, or back to back 24-hour rainfall events, an
SCS Type II distribution should be used. For shorter duration, critical events other
distributions may be used with the approval of the City Engineer.
5. All drainage system analyses and designs shall be based on proposed full development land
use patterns. A Type II 24-hour rainfall distribution with average antecedent moisture
conditions should be utilized for runoff calculations.
6. The recommended minimum outlet diameter is 6 inches due to plugging susceptibility and
may supersede the rate control requirement for the 2-year event.
7. City standard detail plates should be utilized for pond outlet structures.
8. Outlet structures should be designed in three phases with primary outlet structure and
secondary overflow structure routed to the storm sewer and a defined emergency overflow
as the tertiary outlet structure.
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8.6 Floodplain Management
The City prohibits encroachment or filling activities within the 100-year floodplain.
Encroachment into a 100-year floodplain is discouraged but will be allowed if compensatory
floodplain storage is provided in the same waterbody or drainage district and excavated areas
are properly protected against erosion. Applications proposing to alter the floodplain shall
submit the following:
1. Cut/fill diagrams along with calculations demonstrating that the filling or alteration of the
floodplain is not resulting in a reduction in the flood stage/storage;
2. Compensatory floodplain storage within +/– 1 foot of the floodplain impacts in the same
floodplain section of the proposed work; and
3. Proper stabilization of excavated areas.
8.7 Buffers
Buffers are required adjacent to wetlands for projects requiring a stormwater management
permit as defined in the City Zoning Code: Chapter 36.
1. Plant species shall be selected from wetland and upland plants to provide habitat for various
species of wildlife.
2. Buffer strips shall be identified by permanent monumentation acceptable to the city. A
monument is required wherever a buffer strip intersects a lot line.
3. Buffer strips for high quality wetlands shall be 40 feet in width; however, the city council
may approve a buffer strip of variable width so long as the minimum width is 25 feet and
the average width is 40-feet. Buffer strips for all other wetlands shall be a minimum of ten
feet in width. Total applicable building setback from the edge of a wetland shall conform
with the building setback requirement of the zoning district in addition to the buffer width
required by this section.
8.8 Shoreland Management
The City of Medina has an established adopted Shoreland District Code, Division 5 of the Zoning
Code. The Zoning Code has established setbacks for placement of structures and impervious
and also requirements for shoreland alterations. The City also encourages the following for
work occurring within the shoreland zone:
1. Encourage the use of natural vegetation or bioengineering techniques for the stabilization of
shorelines.
2. Use materials such as granite or fieldstone for shoreline stabilization project where hard
armoring is necessary.
3. Encourage the use of techniques that will minimize runoff and improve water quality
associated with new development and redevelopment. When possible use existing natural
drainage ways, wetlands, and vegetated soil surfaces to convey, store, filter, and retain
stormwater runoff before discharge to public waters. When development density,
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City of Medina, MN Page 28
topographic features, and soil and vegetation conditions are not sufficient to adequately
handle stormwater runoff using natural features and vegetation, various types of
constructed facilities such as diversions, settling basins, skimming devices, dikes, waterways,
and ponds may be used. Preference shall be given to designs using surface drainage,
vegetated filter strips, bioretention areas, rainwater gardens, enhanced swales, off-line
retention areas, and natural depressions for infiltration rather than buried pipes and
human-made materials and facilities (MnDNR Alternative Shoreland Standards, 2005).
8.9 Mitigation Requirements
Under certain circumstances, some construction projects cannot meet the TSS and/or TP
reduction requirements for new or redevelopment projects on the site of the original
construction. All methods must be exhausted prior to considering alternative locations where
TSS and TP treatment standards can be achieved. If the City has determined that all methods
have been exhausted, the permittee will be required to identify alternative locations where TSS
and TP treatment standards can be achieved.
• Mitigation projects will be chosen in the following order of preference:
1. Locations that yield benefits to the same receiving water that receives runoff from the
original construction activity.
2. Locations within the same Department of Natural Resource (DNR) catchment area as
the original construction activity.
3. Locations in the next adjacent DNR catchment area up-stream.
4. Locations anywhere within the City of Medina.
• Mitigation projects shall involve the establishment new structural stormwater BMPs or the
retrofit of existing structural stormwater BMPs, or the use of a properly designed regional
structural stormwater BMP.
• Previously required routine maintenance of structural stormwater BMPs cannot be
considered mitigation.
• Mitigation projects must be finished within 24 months after the original construction activity
begins.
8.10 Long Term Inspection and Maintenance of Stormwater Facilities
1. No private stormwater facilities may be approved unless a maintenance plan is provided
that defines how access will be provided, who will conduct the maintenance, the type of
maintenance and the maintenance intervals. At a minimum, all private stormwater facilities
shall be inspected annually and maintained in proper condition consistent with the
performance goals for which they were originally designed and as executed in the
stormwater facilities maintenance agreement.
2. Access to all stormwater facilities must be inspected annual and maintained as necessary.
The applicant shall obtain all necessary easement or other property interests to allow access
Stormwater Management Design Standards
City of Medina, MN Page 29
to the facilities for inspection or maintenance for both the responsible party and the City of
Medina.
3. All settled materials including settled solids, shall be removed from ponds, sumps, grit
chambers, and other devices, and disposed of properly.
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City of Medina, MN Page 30
9. STORM SEWER DESIGN STANDARDS
9.1 Storm Sewers
1. Manhole spacing shall not exceed 400 feet.
2. Where more than one pipe enters a structure, a catch basin/manhole shall be used.
3. Storm sewer pipe should match top of pipe on top of pipe unless grade constraints prevent
this. In that case, hydraulic calculations will be necessary to verify that excessive
surcharging will not occur.
4. Stormwater pipes shall be designed utilizing the Rational Method. Channel design shall be
hydrograph method only. All methods are subject to the City Engineer’s approval.
5. Lateral systems shall be designed for the 10-year rainfall using the Rational Method. State
Aid roadway storm sewer shall be designed per the State Aid requirements.
6. The minimum full flow velocity within the storm sewer should be 3 feet per second (fps).
The maximum velocity shall be 10 fps, except when entering a pond, where the maximum
velocity shall be limited to 6fps.
7. Trunk storm sewer should be designed at a minimum to carry 100-year pond discharge in
addition to the 5-year design flow for directly tributary areas. The following table shall be
used for the calculation of peak rates using the Rational Method:
Cover Type 10-Year Runoff Coefficient
Single-family Residential 0.4
Multi-family Residential 0.5
Commercial 0.7
Industrial 0.7
Parks, Open Space 0.2
Ponds, Wetlands 1.0
8. For storms, greater than the 5-year event, and in the case of plugged inlets, transient street
ponding will occur. For safety reasons, the maximum depth in streets should not exceed 1.5
feet at the deepest point.
9. To promote efficient hydraulics within manholes, manhole benching shall be provided to 1/2
diameter of the largest pipe entering or leaving the manhole.
10. Vaned grate catch basin castings, in accordance with the City’s Standard Details, shall be
used on all streets.
11. The maximum design flow at a catch basin for the 5-year storm event shall be three (3) cubic
feet per second (cfs), unless high capacity grates are provided. Catch basins at low points
will be evaluated for higher flow with the approval of the City Engineer.
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City of Medina, MN Page 31
12. All structures located in the street are to be a minimum of four feet deep (rim to invert) and
a minimum of three feet deep elsewhere. Two-by-three catch basins are to be four (4) feet
deep.
9.2 Outlet and Inlet Pipes
1. Inlet pipes of stormwater ponds shall be extended to the pond normal water level whenever
possible.
2. Outfalls with velocities greater than 4 fps into channels, where the angle of the outfall to the
channel flow direction is greater than 30 degrees, requires energy dissipation or stilling
basins.
3. Outfalls with velocities of less than 4 fps, that project flows downstream into a channel in a
direction 30 degrees or less from the channel flow direction, generally do not require energy
dissipaters or stilling basins, but will require riprap protection.
4. In the case of discharge to channels, riprap shall be provided on all outlets to an adequate
depth below the channel grade and to a height above the outfall or channel bottom. Riprap
shall be placed over a suitably graded filter material and filter fabric to ensure that soil
particles do not migrate though the riprap and reduce its stability. Riprap shall be placed to
a thickness at least 2.5 times the mean rock diameter to ensure that it will not be
undermined or rendered ineffective by displacement. If riprap is used as protection for
overland drainage routes, grouting may be recommended.
5. Discharge velocity into a pond at the outlet elevation shall be 6 fps or less. Riprap
protection is required at all inlet pipes into ponds from the NWL to the pond bottom.
6. Where outlet velocities to ponds exceed 6 fps, the design should be based on the unique
site conditions present. Submergence of the outlet or installation of a stilling basin
approved by the City is required when excessive outlet velocities are experienced.
7. Submerged outlet pipes from ponds are not allowed.
9.3 Channels and Overland Drainage
1. Overland drainage routes where velocities exceed 4 fps should be reviewed by the City
Engineer and approved only when suitable stabilization measures are proposed.
2. Open channels and swales are recommended where flows and small grade differences
prohibit the economical construction of an underground conduit. Open channels and
swales can provide infiltration and filtration benefits not provided by pipe.
3. The minimum grade in all unpaved areas shall be 2%.
4. Maximum length for drainage swales shall be 400 feet.
5. Channel side slopes should be a maximum of 4:1 (horizontal to vertical) with gentler slopes
being desirable.
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City of Medina, MN Page 32
6. Riprap shall be provided at all points of juncture, particularly between two open channels
and where storm sewer pipes discharge into a channel.
7. Open channels should be designed to handle the expected velocity from a 10-year design
storm without erosion. Riprap may need to be provided.
8. Periodic cleaning of an open channel is required to ensure that the design capacity is
maintained. Therefore, all channels shall be designed to allow easy access for equipment.
9.4 Ponds
Where on-site water quality detention basins are required, copies of the calculations
determining the design of the basin(s) will be provided. The size and design considerations will
be dependent on the receiving water body's water quality category, the imperviousness of the
development and the degree to which on-site infiltration of runoff is achieved. Design of on-site
detention basins, as described in the site's runoff water management plan, shall incorporate
recommendations from the nationwide urban runoff program (NURP) and "Protecting Water
Quality in Urban Areas", published by the Minnesota Pollution Control Agency, as adopted by
the City, or the applicable publications, as adopted by the City. The following design
considerations are required for on-site water quality detention basins based on the receiving
water's water quality category. These designs include permanent detention for water quality
treatment; extended detention designs may be substituted provided that they provide
treatment equivalent to the requirements below:
1. A permanent pool (dead storage) volume below the normal outlet shall be greater than or
equal to the runoff from a two and one-half inch (2.5") 24-hour storm over the entire
contributing drainage area assuming full development.
2. A permanent pool average depth (basin volume/basin area) which shall be greater than four
feet (4'), with a maximum depth of less than ten feet (10').
3. An emergency spillway (emergency outlet) adequate to control the 100-year frequency
critical duration rainfall event.
4. Basin side slopes above the normal water level should be no steeper than three to one (3:1)
when possible, and preferably flatter. A basin shelf with a minimum width of ten feet (10')
and a maximum slope of five to one (5:1) below the normal water level is recommended to
enhance wildlife habitat, reduce potential safety hazards, and improve access for long term
maintenance.
5. To prevent short circuiting, the distance between the major inlets and normal outlet shall be
maximized.
6. A flood pool (temporary storage) volume above the principal outlet spillway shall be
adequate so that the peak discharge rate from the 1-, 10- and 100-year frequency critical
duration storm is not greater than the peak discharge for a similar storm and
predevelopment watershed conditions.
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City of Medina, MN Page 33
7. Extended detention of runoff from the more frequent (1-year to 5-year) storms shall be
achieved through a principal spillway design which shall include a perforated vertical riser, a
small orifice outlet or a compound weir. The spillway must be constructed of a limited
maintenance material. The use of treated or naturally decay resistant timber shall not be
allowed.
9.5 Freeboard
Elevation separations of buildings with respect to ponds, lakes, streams, and stormwater
features shall be designed as follows:
1. The basement floor elevation of any new building shall be placed at least two (2) feet above
the elevation of any known historic high groundwater elevations for the area and at least
two (2) feet above the 100-year high surface water elevation in the area.
2. The low building opening elevation of any new building shall be at least three (3) feet above
the projected 100-year high water elevation for the area. If this standard is considered a
hardship, the standard may be lowered to placing the low building opening elevation at
least two (2) feet above the projected 100-year high water elevation if the following can be
demonstrated:
a) That within the two-foot freeboard area above the 100-year high water elevation,
stormwater storage is at least 50 percent of the stormwater storage capacity below the
100-year high water elevation; and
b) That a 25 percent obstruction of the basin outlet for a 100-year critical-duration rainfall
event would not result in a high-water elevation greater than one foot above the 100-
year high water elevation; and
c) An adequate overflow route from the basin will assure that water levels, even for 100-
year rainfall events, will be greater than one foot below the low building opening
elevation.
3. An emergency spillway from ponding areas shall be installed a minimum of one (1) foot
below the lowest building opening and shall be designed to have a capacity to overflow
water at an elevation below the lowest building opening at a rate not less than three times
the 100-year peak discharge rate from the basin or the 100-year inflow rate to the basin,
whichever is higher.
9.6 Emergency Overflow Paths
1. Emergency Overflows (EOFs) shall be sized with a minimum bottom width of five feet and
4:1 side slopes.
2. The maximum flow depth in EOFs shall be less than equal to one foot as calculated for a
100-year back-to-back storm event.
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City of Medina, MN Page 34
10. DESIGN EXAMPLES
The design process for each of the acceptable Stormwater Treatment Practices is detailed in the
Minnesota Stormwater Manual, http://stormwater.pca.state.mn.us/index.php/Main_Page.
Stormwater Management Design Standards
City of Medina, MN Page 35
11. STORMWATER TREATMENT PRACTICE DETAIL DRAWINGS
Please refer to the City of Medina’s Engineering Details for the following:
• Bio retention
• Media Filter System
• Vegetative Filter System
• Infiltration Trench
• Infiltration Basin
• Stormwater Pond/Wetland
Stormwater Management Design Standards
City of Medina, MN Page 36
12. CONSTRUCTION SPECIFICATIONS
Construction specifications and details are found within the City Standard Details as well as in the
Minnesota Stormwater Manual for each of the acceptable STPs, unless otherwise restricted by this
manual.
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City of Medina, MN Page 37
13. CHECKLISTS
Refer to the Forms section of the City’s SWPPP program.
• Stormwater Plan Review Inspection
• Checklist for Construction Inspection and Operation & Maintenance
• Construction Inspection and Operation & Maintenance Checklists for each of the approved
Stormwater Treatment Practices are available in the Minnesota Stormwater Manual.
Standard Operating Procedure
1
Minimum Control Measure 6
Pollution Prevention and Good Housekeeping Practices for
Municipal Facilities
6.1 OPERATIONS
Objective of the SOPs
This manual is intended to provide guidance on good housekeeping practices for municipal operations as
follows:
• Provide BMPs used for municipal activities.
• Provide BMPs to prevent or reduce the stormwater impacts from the facilities documented on the
Faculty Inventory
• Provide BMPs to protect Source Water Protection Areas, such as Drinking Water Supply
Management Areas and source water protection areas for surface intakes
• Stormwater pond assessment procedures and schedule to evaluate the effectiveness of total
suspended solids (TSS) and total phosphorus (TP) removal of municipally owned/operated
ponds.
• Provide methods for employing spill prevention and response.
• Provide tools for documenting inspections of municipal facilities
Work Schedule
Inspection and maintenance is performed in conjunction with and can be impacted by other maintenance
operations. Inspection and maintenance will typically be conducted during a regular eight (8) hour
workday. Extended workdays and shift changes may be necessary for spring runoff events and
emergency conditions to provide maximum efficiency. For safety reasons, no operator will work more
than a twelve (12) hour shift in any twenty-four (24) hour period.
Training
The City of Medina will provide training and information on an annual basis to employees involved in
the inspection and maintenance of the City’s storm drainage system, illicit discharge detection,
construction site maintenance, and general municipal good housekeeping. At a minimum, training and
information will cover:
• Inspection/maintenance procedures
• Reasons for inspection/maintenance
• Erosion and sediment control inspection/maintenance practices
• Good housekeeping practices associated with municipal activities
• Daily, intermediate and long-term preventative inspection/maintenance
Standard Operating Procedure
2
• Major/minor repairs
• Vegetation inspection
• Stormwater basins versus wetlands
• Spills or illegal dumping into the storm sewer system
• Public stormwater basins versus private stormwater basins
• Stormwater basins with vegetation requiring additional inspection/maintenance
The City’s training program shall include:
• The importance of protecting water quality.
• The requirements of the permit relevant to the responsibilities of the individual.
• A schedule that establishes initial training for individuals, including new and/or seasonal employees,
and recurring training intervals to address changes in procedures, practices, techniques, or
requirements.
The City’s winter maintenance training program shall include:
• The importance of protecting water quality.
• BMPs to minimize the use of deicers (e.g., proper calibration of equipment and benefits of
pretreatment, pre-wetting, and anti-icing); and
• Tools and resources to assist in winter maintenance (e.g., deicing application rate guidelines,
calibration charts, Smart Salting Assessment Tool)
The Public Works Director will supply the new/seasonal employees, upon hiring, with a new employee
packet. This packet will consist of standard Human Resources items, but also supply the new employee
with the standard MS4 items covered in training; MS4 items that will be included in the packet, but not
limited to:
• Standard Operating Procedures for inspection processes, including inspection forms
• PDF of the most recent annual MS4 training
• IDDE fact sheet
• Cover sheet which includes a signature location that will be turned into the direct supervisor for
annual MS4 documentation purposes
The most recent annual MS4 training will be emailed to the emergency response departments within the
City if those individuals cannot attend the scheduled training.
Complaints
Complaints concerning the storm drainage system will be taken during normal working hours and after
normal working hours by those designated as emergency contacts. Problems requiring immediate
attention will be handled on a priority basis as determined by the Public Works Director. The City will
document all complaints and upgrade this procedure as necessary while giving consideration to the
constraints of available resources.
Standard Operating Procedure
3
Documentation
The City of Medina will document the inspection, maintenance, complaint and emergency responses
actions as defined by this document and ensure the Public Works Director is responsible for the
implementation of this MCM. The inspection and maintenance activities associated with the storm sewer
system and stockpile/storage material handing areas will be completed using the forms provided in this
document or through the City’s Cartegraph system.
City will continually track annual training sessions, including MS4 trainings. Documentation will
include the training sign-in sheet as well as any new employee/seasonal employee signed packet.
Documents of MS4 activities to be saved on the City network drive within an associated yearly folder.
Maintain a written or mapped inventory of the City’s owned/operated facilities that contribute pollutants
to stormwater discharges:
a. Equipment storage and maintenance
b. Park(s)
c. Public works yard(s)
d. Recycling
e. Salt storage
f. Snow storage
g. Vehicle storage and maintenance (e.g., fueling and washing)
h. Materials storage yard(s)
Standard Operating Procedure
4
6.2 POLLUTION PREVENTION
6.2.1 Dumpsters/Garbage Storage
Activities and Definition
Potential for pollutants can occur if proper garbage management is not in place. An appropriate number
of dumpsters should be located throughout the facility to provide enough storage for daily activities. In
addition facility dumpsters are to be marked for proper materials disposal.
Preparation
Train employees on proper trash disposal.
Locate dumpsters and trash cans in convenient, easily observable areas.
Provide properly labeled recycling bins to reduce the amount of garbage disposed.
Where applicable, install berms, curbing, or vegetation strips around storage areas to control water
entering/leaving storage areas.
Whenever possible, store garbage containers beneath a covered structure or inside to prevent contact
with stormwater.
Process
a. Inspect garbage bins for leaks regularly and have repairs made immediately by responsible party.
b. Request/use dumpsters and trash cans with lids and without drain holes.
c. Locate dumpsters on a flat, hard surface that does not slope or drain directly into the storm drain
system.
Clean-up/Follow-up
a. Keep areas around dumpsters clean of all garbage.
b. Have garbage bins emptied regularly to keep from overfilling.
c. Wash out bins or dumpsters as needed to keep odors from becoming a problem.
Documentation
Document training of employees.
Standard Operating Procedure
5
6.2.2 Parking Lot Maintenance
Activities and Definition
Parking Lots can potentially generate increased pollutant loads to the stormwater system from run-off.
A well-maintained parking surface can help to reduce some of those pollutant concerns.
Preparation
a. Conduct regular employee training to reinforce proper housekeeping.
b. Restrict parking in areas to be swept prior to and during sweeping using regulations as necessary.
c. Perform regular maintenance and services in accordance with the recommended vehicle maintenance
schedule on sweepers to increase and maintain efficiency.
Process
a. Sweep parking areas, as needed, or as directed by the City’s responsible official.
b. Hand sweep sections of gutter if soil and debris accumulate.
c. Pick-up litter as required to keep parking areas clean and orderly.
Clean-up/Follow-up
a. Dispose of sweepings properly (appropriate facility).
b. Street sweepers to be cleaned out in a manner as instructed by the manufacturer and in a location that
swept materials cannot be introduced into a storm drain.
c. Swept materials will not be stored in locations where stormwater could transport fines into the storm
drain system.
Documentation
a. Keep accurate maps and logs to track swept parking areas and approximate quantities.
b. Document training of employees.
Standard Operating Procedure
6
6.2.3 Stockpile and Storage Material Handling Areas
Preparation
a. Conduct regular employee training to reinforce proper housekeeping.
b. Install proper BMPs as indicated on the facility BMP map.
c. Perform regular maintenance of BMPs installed.
Process
a. Quarterly inspect all areas as shown the BMP facility map and as per the facility inspection form.
b. Perform maintenance as directed on the facility inspection form.
Clean-up/Follow-up
a. Install/replace failing BMPs.
b. Purchase new BMPs to ensure adequate quantities are available for maintenance.
c. Equipment not to be cleaned out unless appropriate inlet project device is put in place.
d. Fueling areas are to be inspected for leaks and all spill kits re-stocked.
Documentation
a. Keep inspection and maintenance logs.
b. Logs to be updated quarterly.
Standard Operating Procedure
7
6.3 PARKS
6.3.1 Chemical Application Pesticides, Herbicides, Fertilizers
Activities and Definition
A pivotal part of the beautification of the City is a great parks system. The health and beauty of lawns
and natural areas take the application of some chemicals and fertilizers.
Preparation
a. Make sure the City’s state Chemical Handling Certification is complete and up-to-date before
handling any chemicals. All City of Medina staff who handle chemicals have the appropriate
Applicator’s Certification.
b. Calibrate fertilizer and pesticide application equipment to avoid excessive application.
c. Use pesticides only if there is an actual pest problem and periodically test soils for determining
proper fertilizer use.
d. Time and apply the application of fertilizers, herbicides or pesticides to coincide with the
manufacturer’s recommendations for best results (“Read the Label”).
e. Know the weather conditions. Do not use pesticides if rain is expected. Apply pesticides only when
wind speeds are low (less than 5 mph).
Process
a. Always follow the manufacturer’s recommendations for mixing, application and disposal (“Read the
Label”).
b. Do not mix or prepare pesticides for application near storm drains and never on impervious surfaces.
Employ techniques to minimize off-target application (e.g. spray drift, over broadcasting) of
pesticides and fertilizers.
Clean-up/Follow-up
a. Sweep pavements or sidewalks where fertilizers or other solid chemicals have fallen, back onto
grassy areas before applying irrigation water.
b. Triple rinse containers and use rinse water as product. Dispose of unused pesticide as hazardous
waste.
c. Always follow all federal and state regulations governing use, storage and disposal of fertilizers,
herbicides or pesticides and their containers (“Read the Label”).
Documentation
a. Keep copies of MSD sheets for all pesticides, fertilizers and other hazardous products used.
b. Record fertilizing and pesticide application activities, including date, individual who did the
application, amount of product used and approximate area covered.
Standard Operating Procedure
8
6.3.2 Cleaning Equipment
Activities and Definition
There are many benefits to taking proper care of the City’s equipment. Prolonging the life of the
equipment by taking the time to maintain critical parts is an essential part of the Parks Department’s
daily activities.
Preparation
Review process with all Parks employees.
Process
a. Ensure appropriate inlet protection is installed within adjacent storm sewer structures that may
receive discharge from equipment washing areas.
b. Wipe off dirt, dust and fluids with disposable towel or air compressor.
c. If detergents are used wash equipment in approved wash station.
Clean-up/Follow-up
a. Dispose of towels in proper trash receptacle
b. Sweep floor and dispose of debris.
Documentation
N/A
Standard Operating Procedure
9
6.3.3 Mowing and Trimming
Activities and Definition
Regular mowing and trimming activities have potential to deposit materials onto hard surfaces. Care
should be taken to ensure mowing or trimming refuse is disposed of properly.
Preparation
a. Process overview with employees.
b. Check the oil and fuel levels of the mowers and other equipment. Fill in proper areas if needed.
Process
a. Put on eye and hearing protection, as required.
b. Mow and trim the lawn.
c. Sweep or blow clippings to grass areas, then clear with deck of mower.
Clean-up/Follow-up
a. Mowers are cleaned daily. Refer to equipment cleaning procedures.
b. Dry spoils are dry swept and disposed of properly
c. Wash equipment in approved wash station.
Documentation
Document and observed deficiencies for correction or repair.
Standard Operating Procedure
10
6.3.4 Open Space Management
Activities and Definition
Open space provides great value to the park system that go beyond ball fields. This includes stormwater
retention and potential flood relief.
Preparation
a. Provide a regular observation and maintenance of parks, golf courses, and other public open spaces.
b. Identify public open spaces that are used for stormwater detention and verify that detention areas are
included on the storm drain system mapping, inspection schedules, and maintenance schedules.
Process
a. Ensure that any storm drain or drainage system components on the property are properly maintained.
b. Avoid placing bark mulch (or other floatable landscaping materials) in stormwater detention areas or
other areas where stormwater runoff can carry the mulch into the storm drainage system.
c. Follow all SOPs related to irrigation, mowing, landscaping, and pet waste management.
Clean-up/Follow-up
a. Keep all outdoor work areas neat and tidy. Clean by sweeping instead of washing whenever
possible. If areas must be washed, ensure that wash water will enter a landscaped area rather than
the storm drain. Do not use soap for outdoor washing.
b. Pick up trash on a regular basis.
Documentation
Document and observed deficiencies for correction or repair.
Standard Operating Procedure
11
6.3.5 Pet Waste
Activities and Definition
Pet waste has the potential to be a contributor to downstream degradation if not maintained and properly
disposed of.
Preparation
a. Enforce ordinance that requires pet owners to clean up pet wastes and use leashes in public areas. If
public off-leash areas are designated, verify they are clearly defined.
b. Whenever practical and cost effective, install dispensers for pet waste bags and provide disposal
containers at locations such as trail heads or parks where pet waste has been a problem. Provide
signs with instructions for proper cleanup and disposal.
Process
a. Check parks and trails for pet waste as needed.
b. Check public open space for pet waste while mowing and watering.
c. Provide ordinance enforcement as needed. Look for opportunities for increased education.
Clean up/Follow-up
Remove all pet waste; provide temporary storage in a covered waste container and dispose of properly.
Preferred method of disposal is at a solid waste disposal facility.
Documentation
Document problem areas for possible increased enforcement and/or public education signs.
Standard Operating Procedure
12
6.3.6 Planting Vegetation (Starters)
Activities and Definition
Vegetation is a key component of establishing healthy ecosystems that hold water and nutrients on site.
Preparation
a. Call the appropriate numbers for location of utilities.
b. Decide where any spoils will be taken.
Process
a. Dig holes; place spoils near the hole where they may easily be placed back around the roots. Avoid
placing spoils into the gutter system.
b. Bring each plant near the edge of the hole dug for it.
c. Check the depth of the hole and adjust the depth if necessary. The depth of the hole for a tree should
be as deep as the root ball, so that the top of the root ball is level with the top of the hole.
d. Carefully remove pot or burlap.
e. Place the plant in the hole.
f. Backfill the hole with existing spoils, compost, and fertilizer if desired. Do not use excessive
amendments.
g. Water the plant.
h. Stake the plant if necessary to stabilize it.
Clean-up/Follow-up
a. Remove any extra spoils into truck or trailer. Place the spoils on a tarp if there is likelihood that
some of the dirt would be lost through openings in the bed.
b. Sweep dirt from surrounding pavement(s) into the planter area.
c. Transport spoils to their designated fill or disposal area.
Documentation
N/A
Standard Operating Procedure
13
6.3.7 Planting Vegetation (Seeds)
Activities and Definition
Vegetation is a key component of establishing healthy ecosystems that hold water and nutrients on site.
Preparation
a. Call the appropriate numbers for location of utilities.
b. Decide where any spoils will be taken.
c. Decide on the application rate, method, water source, and ensure adequate materials are on hand.
d. Grade and prepare soil to receive the seed. Place any extra soil in a convenient location to collect.
Process
a. Place the seed and any cover suing the pre-determined application method (and rate).
b. Lightly moisten the seed.
Clean-up/Follow-up
a. Remove any extra spoils into truck or trailer. Place the spoils on a tarp if there is likelihood that
some of the dirt would be lost through openings in the bed.
b. Sweep dirt from surrounding pavement(s) into the planter area.
c. Transport spoils to their designated fill or disposal area.
Documentation
N/A
Standard Operating Procedure
14
6.3.8 Transporting Equipment
Activities and Definition
Equipment Transportation is a pivotal part of the daily activities that occurs on a daily basis.
Preparation
a. Determine equipment needed for transport and method (trailer, truck bed) needed to transport
equipment, if required.
b. Conduct pre-trip inspection of equipment.
Process
a. Load and secure equipment on trailer or truck.
b. Load and secure fuel containers for equipment usage.
Clean-up/Follow-up
a. Off load equipment.
b. Store equipment and trailer in proper location.
c. Conduct post-trip inspection of equipment, if required.
d. Wash equipment if needed, according to the written procedure for cleaning equipment.
Documentation
Pre-trip and post-trip inspection report, if required.
Standard Operating Procedure
15
6.4 SANITARY SEWER – OVERFLOWS
Activities and Definition
Sanitary sewer system even with high-performing operation and maintenance programs will experience
overflows and backups from time to time. A proper response plan will help mitigate the effects of a
backup and it will be necessary to contact the Minnesota State Duty Officer.
Preparation
a. Train staff to make them aware of the need to report the spill and spill response/clean-up procedures
(Appendix C).
b. Have all equipment ready to assist with spill clean-up or containment (e.g., confined space entry
equipment, safety gear, jet flushing unit/vacuum truck, pumps, disinfectants, televising equipment,
etc.)
c. Have sewer maps available.
Process
a. Report sanitary sewer spill to Minnesota State Duty Officer at (651)-422-0798 or 1-800-422-0798.
b. Typical information requested by the Minnesota State Duty Officer includes:
1. Name of caller
2. Date, time, and location of incident
3. Telephone number for call-backs at the scene or facility
4. Whether local officials have been notified
5. Materials and quantity involved in the incident
6. Incident location
7. Responsible party
8. Any surface waters or sewers impacted
9. Present situation of the spill (on-going or contained)
c. Inform the public if they are at risk (e.g., spill nears swimming beached, public drinking water
intakes, and recreational areas. Notification mechanisms may include:
1. Hand delivery of door hangers
2. Temporary posting at impacted areas
3. Notifications in newspaper, radio announcements, messages on local access cable channel,
messages on website, and social media.
Standard Operating Procedure
16
6.5 STREETS
6.5.1 Overlays and Patching
Activities and Definition
Pollutants collect on surfaces in between storm events as a result of atmospheric deposition, vehicle
emissions, winter road maintenance, construction site debris, trash, road wear and tear. Overlays and
patching are a part of the maintenance of these surfaces that help prolong the life of the roadway.
Preparation
a. Measure and mark locations of manholes and valves on the curb.
b. Cracks should be properly sealed. Alligator cracks and potholes should be removed and patched.
Rutting should be milled.
c. Surface should be clean and dry.
d. Uniform tack coat applied and cured prior to placement of overlay.
e. If milling is required, install inlet protection as needed.
Process
a. Check hot asphalt mix for proper temperature, percentage asphalt, gradation, air voids, and any other
agency requirements.
b. Raise manhole lids and valves to elevation of new asphalt surface with riser rings.
c. Surface texture should be uniform, no tearing or scuffing.
d. Rolling should be done to achieve proper in-place air void specification.
Clean up/Follow-up
a. Covering should be removed as soon as the threat of imported materials entering the system is
reduced and prior to a storm event.
b. After pavement has cooled, sweep gutters to remove loose aggregate.
Documentation
NA
Standard Operating Procedure
17
6.5.2 Crack Seal
Activities and Definition
Pollutants collect on surfaces in between storm events as a result of atmospheric deposition, vehicle
emissions, winter road maintenance, construction site debris, trash, road wear and tear. Crack sealing is
a part of the maintenance of these surfaces that help prolong the life of the roadway.
Preparation
a. Remove weeds from the road.
b. Air-blast the cracks to remove sediments from the crack to allow for proper adhesion.
c. Ensure that surface is clean and dry.
d. Sweep within 24 hours
Process
a. Proper temperature of material should be maintained.
b. Sufficient material is applied to form the specified configuration.
Clean-up/Follow-up
a. Excessive sealant application or spills are removed.
b. Sweep all loose debris from the pavement and dispose of it in the local landfill.
Documentation
Record location and date on the maintenance database and map.
Standard Operating Procedure
18
6.5.4 Shouldering and Mowing
Activities and Definition
Pollutants collect on surfaces in between storm events as a result of atmospheric deposition, vehicle
emissions, winter road maintenance, construction site debris, trash, road wear and tear, and litter from
adjacent lawn maintenance (grass clippings). The shoulders of the road should be properly maintained
to ensure infiltration and other techniques for stormwater run-off are working with the most efficiency.
Preparation
Set up temporary traffic control devices
Process
a. Place import material as needed and perform grading to achieve proper drainage.
b. Mulch clippings to help reduce the amount of supplemental fertilizer required.
Clean up/Follow-up
Clean any loose material off asphalt or gutter.
Documentation
Record location and date on the maintenance database and map.
Standard Operating Procedure
19
6.5.5 Secondary Road Maintenance
Activities and Definition
Plans that are submitted to the City of Medina for approval will have a review process to guarantee that
erosion and sediment control standards are being met.
Preparation
a. Determine length amount and type of road base or gravel that will be needed.
b. Determine proper equipment to be used and or any safety hazards.
c. Design proper drainage: slopes, berms, etc.
Process
a. Have truck drivers follow a designated route for hauling in the soil (See SOP for transporting soil
and gravel).
b. If soils are too dry to achieve compaction, loosen surface material and moisture condition.
c. Smooth or grade soil with the desired crown or cross-slope.
d. Compact soil.
Clean up/Follow-up
a. Replace filter fabric with washed rock (if necessary) on monthly maintenance.
b. Wash equipment if needed, according to the written procedure for cleaning equipment.
c. Clean up any debris on traveled roads and dispose of it in the landfill.
Documentation
Fill out daily activity report in logbook or journal. Include date, time, personnel, and location.
Standard Operating Procedure
20
6.5.6 Concrete Work
Activities and Definition
The use of concrete is a common practice for BMP maintenance, proper management of those materials
is critical for pollution prevention.
Preparation
a. Train employees and contractors in proper concrete waste management.
b. Store dry and wet materials under cover, away from drainage areas.
c. Remove any damaged concrete that may need to be replaced.
d. Prepare and compact sub-base.
e. Set forms and place any reinforcing steel that may be required.
f. Determine how much new concrete will be needed.
g. Locate or construct approved concrete washout facility.
Process
a. Install inlet protection as needed.
b. Avoid mixing excess amounts of fresh concrete on-site.
c. Moisten sub-base just prior to placing new concrete. This helps keep the soil from wicking moisture
out of the concrete into the ground.
d. Place new concrete in forms.
e. Consolidate new concrete.
f. Screed off surface.
g. Let concrete obtain its initial set.
h. Apply appropriate surface finish.
i. Remove forms when concrete will not slump.
Clean-up/Follow-up
a. Perform washout of concrete trucks and equipment in designated areas only.
b. Do not washout concrete trucks or equipment into storm drains, open ditches, streets or streams.
c. Cement and concrete dust from grinding activities is swept up and removed from the site.
d. Remove dirt or debris from street and gutter.
Documentation
N/A
Standard Operating Procedure
21
6.5.7 Garbage Storage
Activities and Definition
Illegal dumping of non-hazardous household waste and improper dumping of yard waste in streets,
storm drains, wetlands, lakes, and other water bodies pollutes surface waters. Non-hazardous household
waste includes items such as tires, furniture, common household appliances and other bulk items. Yard
waste includes any organic debris such as grass clippings, leaves, and tree branches.
Preparation
a. Locate dumpsters and trash cans with lids in convenient, easily observable areas.
b. Provide properly labeled recycling bins to reduce the amount of garbage disposed.
c. Provide training to employees to prevent improper disposal of general trash.
Process
a. Inspect garbage bins for leaks regularly, and have repairs made immediately by responsible party.
b. Locate dumpsters on a flat, impervious surface that does not slope or drain directly into the storm
drain system.
c. Install berms, curbing or vegetation strips around storage areas to control water entering/leaving
storage areas.
d. Keep lids closed when not actively filling dumpster.
Clean-up/Follow-up
a. Keep areas around dumpsters clean of all garbage.
b. Have garbage bins emptied as often as needed to keep from overfilling.
c. Wash out bins or dumpsters as needed to keep odors from becoming a problem. Wash out in
properly designated areas only.
Documentation
N/A
Standard Operating Procedure
22
6.5.8 Snow Removal and De-icing
Activities and Definition
The concentration of chloride is increasing in our surface and ground water largely due to stormwater
runoff from road salt storage piles, areas of excessive application, or simply from years of repeated
application since chloride does not degrade in soil and water. Chloride in road salt and road salt
additives (e.g. ferrocyanide for anti-caking) can create toxic conditions for fish, insects and vegetation.
Preparation
a. Store de-icing material under a covered impervious storage area indoors or in an area where water
coming off the de-icing materials is collected and delivered to the sanitary sewer or reused as salt
brine in order to implement practices to reduce exposure when transferring material from salt storage
areas (e.g., sweeping, diversions, and/or containment).
b. Slope loading area away from storm drain inlets.
c. Design drainage from loading area to collect runoff before entering stormwater system.
d. Washout vehicles (if necessary) in approved washout area before preparing them for snow removal.
e. Calibrate spreaders to minimize amount of de-icing material used and still be effective.
f. Provide vehicles with spill cleanup kits in case of hydraulic line rupture or other spill.
g. Train employees in spill cleanup procedures and proper handling and storage of de-icing materials.
Process
a. Load material into trucks carefully to minimize spillage.
b. Periodically dry sweep loading area to reduce the amount of de-icing materials exposed to runoff.
c. Distribute the minimum amount of de-icing material to be effective on the roads.
d. Do not allow spreaders to idle while distributing de-icing materials.
e. Park trucks loaded with de-icing materials inside when possible.
Clean-up/Follow-up
a. Sweep up all spilled de-icing material around loading area.
b. Clean out trucks after snow removal duty in approved washout area.
c. Provide maintenance for vehicles in covered areas.
d. If sand is used in de-icing operations, sweep up residual sand form streets when weather permits.
e. The City shall implement a written snow and ice management policy for individuals that perform
winter maintenance activities for the City. The policy shall establish practices and procedures for
snow and ice control operations (e.g., plowing or other snow removal practices, sand use, and
application of deicing compounds).
Standard Operating Procedure
23
Documentation
Fill out daily activity report in logbook or journal. Include date, time, personnel, and location, as
appropriate.
Document the following information associated with the City’s operations and maintenance program:
• Date(s) and description of findings, including whether or not an illicit discharge is detected, for all
inspections conducted in accordance with items 21.9 and 21.10.
• Any adjustments to inspection frequency as authorized in item 21.9.
• Date(s) and a description of maintenance conducted as a result of inspection findings, including
whether or not an illicit discharge is detected.
• Schedule(s) for maintenance of structural stormwater BMPs and outfalls when necessary,
maintenance cannot be completed within one year of discovery
• Stormwater management training events, including general subject matter covered, names and
departments of individuals in attendance, and date of each event.
Standard Operating Procedure
24
6.5.9 Street Sweeping
Activities and Definition
Pollutants collect on surfaces in between storm events as a result of atmospheric deposition, vehicle
emissions, winter road maintenance, construction site debris, trash, road wear and tear, and litter from
adjacent lawn maintenance (grass clippings). Sweeping of materials such as sand, salt, leaves and debris
from city streets, parking lots and sidewalks prevents them from being washed into storm sewers and
surface waters. Timing, frequency and critical area targeting greatly influence the effectiveness of
sweeping.
Preparation
a. Prioritize cleaning routes based on areas with highest priority.
b. Restrict street parking prior to and during sweeping using regulations as necessary.
c. Increase sweeping frequency just before the rainy season, unless sweeping occurs continuously
throughout the year.
d. Perform preventative maintenance and services on sweepers to increase and maintain their
efficiency.
Process
a. Streets are to be swept as needed or specified by the City; street maps are used to ensure all streets
are swept at a specific interval.
b. Drive street sweeper safely and pick up debris.
c. When full take the sweeper to an approved street sweeper cleaning station.
Clean-up/Follow-up
a. Street sweepers are to be cleaned out in an approved street sweeper cleaning station.
b. Street sweeping cleaning stations shall separate the solids from the liquids.
c. Once solids have dried out, haul them to the local landfill.
d. Decant water is to be collected and routed to an approved wastewater collection system area only.
e. Haul all dumped material to the landfill.
Documentation
Highlight the City Street map to show progress being made as the City sweeps its streets in the spring
and fall.
Standard Operating Procedure
25
6.5.10 Transporting Soil and Gravel
Activities and Definition
Transportation of materials should be handled with pre-planning and contingency planning.
Preparation
a. Dry out wet materials before transporting.
b. Spray down dusty materials to keep from blowing.
c. Make sure the City of Medina knows and understand the SWPPP requirements for the site the City
will be working at.
d. Determine the location that the truck and other equipment will be cleaned afterwards.
Process
a. Use a stabilized construction entrance to access or leave the site where materials are being
transported to/from.
b. Cover truck bed with a secured tarp before transporting.
c. Follow the SWPPP requirements for the specific site to /from which the materials are being hauled.
d. Make sure not to overfill materials when loading trucks.
Clean-up/Follow-up
a. Use sweeper to clean up any materials tracked out on the roads from site.
b. Washout truck and other equipment when needed in properly designated area.
Documentation
Keep records of any material that is tracked out of site and what was done to clean it up and how long it
took to clean up and what the weather conditions were at the time.
Standard Operating Procedure
26
6.6 STORM DRAINAGE SYSTEM
6.6.1 Catch Basins
Activities and Definition
Catch basin cleaning needs to be completed on a regular basis to insure the functionality of the storm
sewer system.
Preparation
a. Clean sediment and trash off of grate.
b. Do visual inspection on outside of grate.
c. Make sure nothing needs to be replaced.
d. Do inside visual inspection to see what needs to be cleaned.
Process
a. Clean using a high-powered vacuum truck to start sucking out standing water and sediment.
b. Use a high-pressure washer to clean any remaining material out of catch basin, while capturing the
slurry with the vacuum.
c. After catch basin is clean, send the rodder of the vacuum truck downstream to clean pipe and pull
back sediment that might have gotten downstream of pipe.
d. Move truck downstream of pipe to next catch basin.
Clean-up/Follow-up
a. When vacuum truck is full of sediment, take it to the designated location to dump all the sediment
out of truck into a drying bed.
b. When it evaporates, clean it up with a backhoe/skid loader, put it into dump truck and take to
permanent disposal site (landfill).
Documentation
a. Keep logs of number of catch basins cleaned.
b. Keep any notes or comments of any problems.
c. Document the landfill location of where material is disposed.
Standard Operating Procedure
27
6.6.2 Outfall Inspections/Maintenance
Activities and Definition
Prior to the expiration date of the City’s MS4 permit, the City of Medina shall conduct at least one
inspection of all outfalls (excluding underground outfalls) in order to determine structural integrity,
proper function, and maintenance needs.
Preparation
a. Collect dry weather inspection information whenever possible.
b. Mark the outfall with its identifier for future location and easy reference using pre-manufactured
signs.
c. Medina uses the City’s Cartegraph system to track each inspection; this tracking system is easily
linked to GIS data. Using the inspection form in Cartegraph will automatically generate a report for
the City to use in evaluating the overall maintenance needs and expediting the annual report to the
MPCA.
Process
a. For each outfall inspection, complete the Cartegraph inspection form by selecting the appropriate
outfall to automate the designated inspection inquiries
b. In the event that Cartegraph is not available, complete a paper outfall inspection form, then the
information will need to be added to the City’s Cartegraph system when a computer is available.
c. The Outfall Inspection Fact Sheet (Appendix B) can be used to assist in the inspection process.
Clean-up/Follow-up
Follow the procedure of Routine Pond Maintenance for any required maintenance.
Inspect all ponds and outfalls (excluding underground outfalls) each permit term in order to determine
structural integrity, proper function, and maintenance needs.
Documentation
a. Keep logs of number of outfalls inspected each year.
b. Document any maintenance performed.
c. Save all documents within the City’s network designated SWPPP folder using the same folder
structure as provided with the electronic SWPPP provided.
Standard Operating Procedure
28
6.6.3 Structural Stormwater Best Management Practice Inspections/Maintenance
Activities and Definition
Structural Stormwater Best Management Practices (SSBMPs) will be inspected annually to determine
structural integrity, proper function and maintenance needs. SSBMPs include BMPs put in place that
are designed to remove pollutants (i.e., environmental manholes, raingardens, filtration features, etc.).
Preparation
a. Clean sediment and trash off of grate.
b. Do visual inspection on outside of grate.
c. Make sure nothing needs to be replaced.
d. Do inside visual inspection to see what needs to be cleaned.
Process
a. Clean using a high-powered vacuum truck to start sucking out standing water and sediment.
b. Use a high-pressure washer to clean any remaining material out of catch basin, while capturing the
slurry with the vacuum.
c. After catch basin is clean, send the rodder of the vacuum truck downstream to clean pipe and pull
back sediment that might have gotten downstream of pipe.
d. Move truck downstream of pipe to next catch basin.
Clean-up/Follow-up
a. When vacuum truck is full of sediment, take it to the designated location to dump all the sediment
out of truck into a drying bed.
b. When it evaporates, clean it up with a backhoe/skid loader, put it into dump truck and take to
permanent disposal site (landfill).
c. Prior to the expiration date of the General Permit, the City must conduct at least one inspection of all
ponds and outfalls (excluding underground outfalls) in order to determine structural integrity, proper
function, and maintenance needs.
d. The City must determine if repair, replacement, or maintenance measures are necessary in order to
ensure the structural integrity and proper function of structural stormwater BMPs and outfalls.
e. The City must complete necessary maintenance as soon as possible. If the City determines necessary
maintenance cannot be completed within one year of discovery, the City must document a
schedule(s) for completing the maintenance.
f. Inspect and ensure maintenance structural stormwater BMPs annually (excluding stormwater ponds,
which are under a separate schedule below) each calendar year to determine structural integrity,
proper function, and maintenance needs unless the City determines either of the following conditions
apply:
1. Complaints received or patterns of maintenance indicate a greater frequency is necessary; or
Standard Operating Procedure
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2. Maintenance or sediment removal is not required after completion of the first two calendar
year inspections; in which case the City may reduce the frequency of inspections to once
every two (2) calendar years
Documentation
a. Keep logs of number of catch basins cleaned.
b. Record the amount of waste collected.
c. Keep any notes or comments of any problems.
d. Document the landfill location of where material is disposed.
Standard Operating Procedure
30
6.6.4 Pond Inspections
Activities and Definitions
Prior to the expiration date of the City’s MS4 permit, the City shall conduct at least one inspection of all
City owned stormwater ponds and outfalls in order to determine structural integrity, proper function, and
maintenance needs. The City of Medina shall also inspect any privately owned ponds that are under the
City’s maintenance requirements as deemed appropriate a signed maintenance agreement.
Preparation
a. Collect dry weather inspection information whenever possible.
b. Medina uses the City’s Cartegraph system to track each inspection; this tracking system is easily
linked to GIS data. Using the inspection form in Cartegraph will automatically generate a report for
the City to use in evaluating the overall maintenance needs and expediting the annual report to the
MPCA. If a paper form is used during the inspection, then the information will need to be added to
the City’s Cartegraph system when a computer is available.
Process
a. For each pond and outfall inspection, complete the Cartegraph inspection form by selecting the
appropriate pond or outfall to automate the designated inspection inquiries
b. In the event that Cartegraph is not available, complete a paper stormwater pond inspection form,
then the information will need to be added to the City’s Cartegraph system when a computer is
available.
Clean-up/Follow-up
Follow the procedure of Routine Pond Maintenance for any required maintenance.
Documentation
a. Keep logs of number of outfalls inspected each year.
b. Document any maintenance performed.
c. Save all documents within the City’s network designated SWPPP folder using the same folder
structure as provided with the electronic SWPPP provided.
Standard Operating Procedure
31
6.6.5 Routine Pond Maintenance
Activities and Definition
Stormwater ponds remove pollutants transported by rain events through settling and biological uptake.
To function properly, stormwater ponds need to have volume to hold water and wetland plants along the
pond edges and shallow areas. Performing maintenance to stormwater ponds is critical for the long-term
operation of the MS4 system. Routine maintenance is considered a maintenance project that will
remove less than 100 cubic yard of material.
Preparation
a. Schedule the pond maintenance work for a time when dry weather is expected.
b. Do a visual inspection to make sure any grates, structures, manholes, and pipes are in good working
order. Remove manhole covers and grates as necessary for inspecting.
Process
a. Provide outlet protection where feasible to minimize the amount of debris that might leave basin
during cleaning process.
b. Perform routine maintenance, which may include:
1. Removal of trash and other accumulated debris from trash grate.
2. Removal of vegetation around and/or in front of the outlet structure.
3. Repair of side slopes to mitigate erosion issues.
4. Replacement of riprap in front of the outlet to prevent future scour and erosion.
c. Continue cleaning structures and surrounding area as necessary by sweeping and shoveling.
d. Put all material removed from the pond into a dump truck.
e. Some structures might require use of a vacuum truck. If so, use the same procedures described for
cleaning catch basins.
Clean-up/Follow-up
a. After performing maintenance, clean off the concrete pads using dry methods (sweeping and
shoveling).
b. Properly dispose of the material that was removed.
c. Site restoration work, if applicable, shall be conducted as soon as weather conditions permit and may
include:
1. Additional clean-up or maintenance of inlet and outlet structures.
2. Additional site stabilization work including sediment and erosion control.
3. Establishing plant, seed, sod, mulch or vegetation to prevent erosion (above waterline).
4. Professional engineer to sign-off on project completion.
d. Inspect all ponds and outfalls (excluding underground outfalls) each permit term in order to
determine structural integrity, proper function, and maintenance needs
Standard Operating Procedure
32
Documentation
a. Keep logs of each detention basins/pond cleaned including date, individuals involved in cleaning,
and a description of the type of debris removed.
b. Record the amount of waste collected.
c. Keep any notes or comments of any other observations about the maintenance that will help the City
operate and maintain that site in the future.
Standard Operating Procedure
33
6.6.6 Pond Assessment Process
Activities and Definition
The following pond assessment procedures and schedule shall be followed to determine the Total
Suspended Solids (TSS) and Total Phosphorous (TP) treatment effectiveness of City owned and
operated ponds that are constructed for the collection and treatment of stormwater.
Assessment Procedure
At the initiation of a pond assessment, the City of Medina shall evaluate the City-owned and operated
stormwater treatment ponds in year 1 to determine the highest priority pond(s) for assessing TSS and TP
effectiveness. In order to create a pond assessment schedule for the City-owned and operated
stormwater treatment ponds to determine the highest priority pond(s) for assessing TSS and TP
effectiveness, in year 1 the City should prioritize ponds to assess based on the following criteria:
• Age of pond.
• Contributing drainage area characteristics (size, land use, upland treatment, etc.).
• Known concerns based on inspections.
• Type and location of receiving water.
• Sensitivity of receiving water.
• Complaints received from the public
This was previously done in the City of Medina through the development of the City’s Stormwater Asset
Management Program (SWAMP). SWAMP also allows the City to make decisions based on the cost
benefit of doing a pond maintenance project.
The ponds that have been identified as having the highest priority shall be added to a schedule to be
more thoroughly assessed in year 1. The remaining ponds will be reassessed in year 2 using the same
criteria, because priorities and other unknown factors (ex: budget, staff time, equipment availability)
may change from year-to-year. Similar to year 1, the ponds that have been identified as having the
highest priority shall be added to a schedule to be more thoroughly assessed in year 2.
Additional Survey of Pond
From the initial assessment of each pond completed in year 1, the City will perform a more thorough
analysis of the ponds that are found to be half full of sediment, as well as the ponds that are continually
showing signs of needing maintenance, in the following years. The following steps shall be taken to
assess the City pond(s) for TSS and TP treatment effectiveness:
a. Gathering of background information. This may include the following:
1) Original design information, if available (record drawings, design calculations, etc.).
2) As-built survey information, if completed and available.
Standard Operating Procedure
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3) Other significant information available that pertains to the pond.
b. Updating the information that is stored within the SWAMP program to determine TSS and TP
effectiveness and associated SWAMP score to prioritize maintenance.
Clean-up/Follow-up
a. Once the assessment of each pond is complete, a pond maintenance and dredging schedule can be
implemented.
b. The City of Medina will either complete the dredging in-house, or contract it out depending on the
availability of City staff.
c. The dredged materials must be tested, and a disposal plan will be developed, based on the test
results.
d. Sediment removal guidance for the testing and removal of sediment can be found in Appendix A
Documentation
a. Create a record of the schedule determined for basin/pond cleaning.
b. Keep logs of each detention basins/pond cleaned including date, individuals involved in cleaning,
and a description of the type of debris removed.
c. Record the amount of waste collected and the results of the sediment testing (if applicable).
d. Keep any notes or comments of any problems.
Document pond sediment excavation and removal activities including the following:
a. A unique ID number and geographic coordinate of each stormwater pond from which sediment is
removed.
b. The volume (e.g., cubic yards) of sediment removed from each stormwater pond.
c. Results from any testing of sediment from each removal activity.
d. Location(s) of final disposal of sediment from each stormwater pond.
Standard Operating Procedure
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6.6.7 Detention Pond Cleaning
Activities and Definition
Storm drains are gateways that allow pollutants in stormwater to flow untreated from local streets to
lakes, rivers and streams. Residual oil, grease, solids, antifreeze, cigarette butts, yard waste, plastic and
other wastes found on roads, parking lots and driveways pollute downstream waters by increasing
phosphorus levels, reducing oxygen levels and ultimately impairing aquatic habitat for fish and other
organisms as well as drinking water sources. Removing sediment and debris on a regular basis will help
the system in getting the most TP and TSS removal.
Preparation
a. The MPCA requires the City to sample sediment prior to dredging to determine concentrations of 17
cPAHS, non-carcinogenic PAHs, arsenic, and copper.
1. If the annual volume of sediment to be removed is less than 100 cubic yards, then no
chemical testing or sediment characterization is required; however, the City is responsible for
the due diligence in the reuse and/or disposal of this material.
2. When more than 100 cubic yards of sediment need to be removed, the City will need to
complete further analysis of the pond sediment. The sediment will need to be tested and
disposed of in accordance with the guidance found in the MPCA’s Sediment Removal
Guidance (Appendix A).
3. Testing of the ponds can be done so that areas of the pond can be segregated (e.g., if areas of
the pond such as the inlets are identified to have the highest concentrations the areas around
the inlet could be disposed of differently as compared to the remainder of the pond, if the
areas can be segregated sufficiently).
b. If chemical testing or sediment characterization is required, the sediment samples shall be sent to an
analytical laboratory for review.
c. Once the results from the analytical laboratory have been received, a maintenance and disposal plan
will be developed based on the test results. The City shall use sediment removal guidance from the
MPCA in Appendix A.
d. Discuss maintenance needs with the Public Works Director to discuss the next course of action prior
to scheduling any maintenance activities.
e. Schedule the Pond cleaning work for a time when dry weather is expected. Factors that may delay
these activities may include temperatures below thirty-two (32) degrees Fahrenheit, wind, rain, snow
and frozen storm drainage systems. Inspection and maintenance will typically be conducted during a
regular eight (8) hour workday. Extended workdays and shift changes may be necessary for spring
runoff events and emergency conditions to provide maximum efficiency. For safety reasons, no
operator will work more than a twelve (12) hour shift in any twenty-four (24) hour period.
f. Unexpected ponding water can create a dangerous condition for vehicles, motorcyclists, bicyclists,
pedestrians and property. It is not practical to sign all areas for potentially dangerous conditions.
During such events, warning signs indicating a hazard may be placed in the vicinity and other areas
Standard Operating Procedure
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as deemed necessary by the Public Works Director. These signs will remain in place until the
situation has subsided.
g. Remove any sediment and trash from grates, placing it in a truck for disposal.
h. Do a visual inspection to make sure any grates, structures, manholes, and pipes are in good working
order. Remove manhole covers and grates as necessary for inspecting.
Process
a. Provide outlet protection where feasible to minimize the amount of debris that might leave basin
during cleaning process.
b. Start cleaning basin by using backhoe to remove debris and sediment off the bottom.
c. Continue cleaning structures and pond bottom as necessary by sweeping and shoveling.
d. Put all material removed from the pond into a dump truck.
e. Some structures might require use of a vacuum truck. If so use the same procedures described for
cleaning catch basins.
Clean-up/Follow-up
a. After cleaning basins, clean off the concrete pads using dry methods (sweeping and shoveling).
b. Make sure they are swept up and clean.
c. Take the material that was removed to the landfill for final disposal.
d. Take the material that was removed to the landfill for final disposal.
e. After performing maintenance, clean off the concrete pads using dry methods (sweeping and
shoveling).
f. Properly dispose of the material that was removed.
g. Site restoration work, if applicable, shall be conducted as soon as weather conditions permit and may
include:
1. Additional clean-up or maintenance of inlet and outlet structures.
2. Additional site stabilization work including sediment and erosion control.
3. Establishing plant, seed, sod, mulch or vegetation to prevent erosion (above waterline).
4. Professional engineer to sign-off on project completion.
h. Inspect all ponds and outfalls (excluding underground outfalls) each permit term in order to
determine structural integrity, proper function, and maintenance needs.
Documentation
a. Keep logs of each detention basins/pond cleaned including date, individuals involved in cleaning,
and a description of the type of debris removed.
b. Record the amount of waste collected.
c. Keep any notes or comments of any problems.
Standard Operating Procedure
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6.6.8 Ditch Management
Activities and Definition
Storm drains are gateways that allow pollutants in stormwater to flow untreated from local streets to
lakes, rivers and streams. Residual oil, grease, solids, antifreeze, cigarette butts, yard waste, plastic and
other wastes found on roads, parking lots and driveways pollute downstream waters by increasing
phosphorus levels, reducing oxygen levels and ultimately impairing aquatic habitat for fish and other
organisms as well as drinking water sources.
Preparation
a. Monitor ditches as appropriate.
b. Maintain access to ditch channels wherever possible.
c. Contact affected property owners and utility owners.
Process
a. Identify areas requiring maintenance.
b. Determine what manpower or equipment will be required.
c. Identify access and easements to area requiring maintenance.
d. Determine method of maintenance that will be least damaging to the channel and adjacent properties
or utilities.
Clean-up/Follow-up
a. Stabilize all disturbed soils.
b. Remove all tracking from paved surfaces near maintenance site, if applicable.
c. Haul all debris or sediment removed from area to approved dumping site.
Documentation
a. Keep log of actions performed including date and individuals involved.
b. Keep any notes or comments of any problems.
Standard Operating Procedure
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6.7 VEHICLES
6.7.1 Fueling
Activities and Definition
Fueling of equipment and vehicles should always occur in designated areas when possible. Spill
prevention and planning should occur before any fueling takes place.
Preparation
a. Train employees on proper fueling methods and spill cleanup techniques.
b. Install a canopy or roof over aboveground storage tanks and fuel transfer areas.
c. Absorbent spill clean-up materials and spill kits shall be available in fueling areas and on mobile
fueling vehicles and shall be disposed of properly after use.
Process
a. Shut off the engine
b. Ensure that the fuel is the proper type of fuel for the vehicle.
c. Nozzles used in vehicle and equipment fueling shall be equipped with an automatic shut off to
prevent overfill.
d. Fuel vehicle carefully to minimize drips to the ground.
e. Fuel tanks shall not be topped off.
f. Mobile fueling shall be minimized. Whenever practical vehicles and equipment shall be transported
to the designated fueling area in the Facilities area.
g. When fueling small equipment from portable containers, fuel in an area away from storm drains and
water bodies.
Clean-up/Follow-up
a. Immediately clean up spills using dry absorbent (e.g. kitty litter, sawdust, etc.) sweep up absorbent
material and properly dispose of contaminated clean up materials.
b. Large spills shall be contained as best as possible and the Duty officer and Hazmat team should be
notified as soon as possible.
Documentation
a. Comply with underground storage tank records and monitoring requirements.
b. Document training of employees.
Standard Operating Procedure
39
6.7.2 Vehicle and Equipment Storage
Activities and Definition
When hazardous material comes into contact with rain or snow, the pollutants are washed into the storm
sewer system and, ultimately, to surface water bodies and/or ground water. Hazardous materials have
negative impacts on fish habitat, ground water drinking water sources, and recreational uses.
Preparation
a. Inspect parking areas for stains/leaks on a regular basis.
b. Provide drip pans or absorbents for leaking vehicles.
Process
a. Whenever possible, store vehicles inside where floor drains have been connected to sanitary sewer
systems.
b. When inside storage is not available, vehicles and equipment will be parked in the approved
designated areas.
c. Maintain vehicles to prevent leaks as much as possible.
d. Address any known leaks or drips as soon as possible. When a leak is detected a drip pan will be
placed under the leaking vehicle.
e. The shop will provide a labeled location to empty and store drip pans.
f. Clean up all spills using dry methods.
g. Never store leaking vehicles over a storm drain.
Clean-up/Follow-up
a. Any leaks that are spilled on the asphalt will be cleaned up with dry absorbent; the dry absorbent
will be swept up and disposed of in the garbage.
b. The paved surfaces around the building will be swept every two weeks, weather permitting.
Documentation
N/A
Standard Operating Procedure
40
6.7.3 Washing
Activities and Definition
MS4 vehicle washing involves the removal of dust and dirt from the exterior of trucks, boats and other
vehicles, as well as the cleaning of cargo areas and engines and other mechanical parts. Washing of
vehicles and equipment generates oil, grease, sediment and metals in the wash water as well as
degreasing solvents, cleaning solutions and detergents used in the cleaning operations.
Preparation
a. Provide wash areas for small vehicles inside the maintenance building that has a drain system which
is attached to the sanitary sewer system.
b. Provide wash areas for large vehicles on an approved outside wash pad that has a drain system
which is attached to the sanitary sewer system.
c. No vehicle washing will be done where the drain system is connected to the storm sewer system.
Process
a. Minimize water and soap use when washing vehicles inside the shop building.
b. Soap should not be used when washing vehicles outside the shop building.
c. Use hoses with automatic shut off nozzles to minimize water usage.
d. When washing outside the building, it is the operator’s responsibility to make sure all wash water is
contained on the wash pad and does not have access to the storm drain.
e. Never wash vehicles over a storm drain.
Clean-up/Follow-up
a. Sweep wash areas after every washing to collect what solids can be collected to prevent them from
washing down the drain system.
b. Clean solids from the settling pits on an as needed basis.
Documentation
N/A
Standard Operating Procedure
41
6.8 WATER
6.8.1 Planned Waterline Excavation Repair/Replacement
Activities and Definition
Waterline excavation and repair of an MS4 system can potentially involve activities that could affect the
health of the MS4 system. Planning is critical.
Preparation
a. Determine where discharge flow will go.
b. Place inlet protection at nearest downstream storm drain inlets.
c. Clean gutters leading to inlets.
d. Isolate waterline to be worked on.
e. Neutralize any chlorine residual before discharging water. This process is a responsibility of the
contractor. Contractor shall use such projects as a chlorine diffuser.
Process
a. Make efforts to keep water from pipeline from entering the excavation.
b. Direct any discharge to pre-determined area.
c. Backfill and compact excavation.
d. Haul of excavated material or stock pile nearby.
Clean-up/Follow-up
a. Clear gutter/waterway where water flowed.
b. Clean up all areas around excavation.
c. Clean up travel path of trucked material.
Documentation
Complete paperwork.
Standard Operating Procedure
42
6.8.2 Unplanned Waterline Excavation Repair/Replacement
Activities and Definition
Waterline Excavation and repair of an MS4 system can potentially involve activities that could affect the
health of the MS4 system. Unplanned excavations can be additionally tricky and pre-planning is
critical.
Preparation
Make sure service trucks have wattles, gravel bags, or other materials for inlet protection.
Process
a. Slow the discharge.
b. Inspect flow path of discharge water.
c. As much as possible, flows should be directed to the municipal sanitary sewer system for treatment.
d. Protect water inlet areas.
e. Follow planned repair procedures.
f. Haul off spoils of excavation.
g. Consider use of silt filter bags on pumps.
Clean-up/Follow-up
a. Repair eroded areas as needed.
b. Follow planned repair procedures.
c. Clean up the travel path of trucked excavated material.
Documentation
Complete paperwork.
Standard Operating Procedure
43
6.8.3 Transporting Dry Excavated Materials and Spoils
Activities and Definition
Transportation of materials should be handled with pre-planning and contingency planning.
Preparation
a. Utilize truck with proper containment of materials.
b. Determine disposal site of excavated materials.
Process
a. Load
b. Check truck after loading for possible spillage.
c. Transport in manner to eliminate spillage and tracking.
d. Utilize one route for transporting.
Clean-up/Follow-up
a. Clean loading area.
b. Clean transporting route.
c. Wash off truck and other equipment in a designated equipment cleaning area.
Documentation
Complete paperwork.
Standard Operating Procedure
44
6.8.4 Transporting Wet Excavated Materials & Spoils
Activities and Definition
Transportation of materials should be handled with pre-planning and contingency planning.
Preparation
a. Utilize truck with containment for material.
b. Determine disposal site of excavated material.
Process
a. Load and Transport in manner to minimize spillage & tracking of material.
b. Check truck for spillage.
c. Utilize one route of transport.
Clean-up/Follow-up
a. Clean route of transport to provide cleaning of any spilled material.
b. Washout equipment truck and other equipment in designated wash area.
Documentation
Complete paperwork.
Standard Operating Procedure
45
6.8.5 Waterline Flushing for Routine Maintenance
Activities and Definition
Flushing is a process that rapidly removes water from the city's water piping system. Flushing uses
water force to scour out materials that accumulate in the city's pipes. Water pipes are usually flushed by
opening fire hydrants, where the discharged water flows off the streets the same as rainwater.
Preparation
a. Determine flow path of discharge to inlet of waterway.
b. Determine chlorine residual.
c. Neutralize chlorine residual.
Process
a. Clean flow path.
b. Protect inlet structures.
c. Use diffuser to dissipate pressure to reduce erosion possibilities.
Clean-up/Follow-up
a. Clean flow path.
b. Remove inlet protection.
Documentation
NA
Standard Operating Procedure
46
6.8.6 Waterline Flushing after Construction/System Disinfection with Discharge to Storm
Drain
Activities and Definition
Flushing is a process that rapidly removes water from the city's water piping system. Flushing uses
water force to scour out materials that accumulate in the city's pipes. Water pipes are usually flushed by
opening fire hydrants, where the discharged water flows off the streets the same as rainwater.
Preparation
a. Determine chlorine content of discharge water and select de-chlorination equipment to be used.
b. Determine flow path of discharge.
Process
a. Protect inlets in flow path.
b. Install de-chlorination equipment.
c. Sweep and clean flow path.
d. Use a diffuser to reduce velocities.
Clean-up/Follow-up
a. Pick up inlet protection.
b. Clean flow paths.
c. Remove equipment from flush point.
Documentation
a. Residual tests of discharge water.
b. Complete paperwork.
Standard Operating Procedure
47
6.8.7 Chemical Handling/Transporting and Spill Release
Activities and Definition
Hotspot facilities are facilities that produce higher levels of stormwater pollutants and/or present a
higher potential risk for spills, leaks or illicit discharges. Hazardous material storage and handling is of
particular concern in these areas.
Preparation
a. Understand MSDS sheets for handling of product.
b. Determine proper place of handling.
c. Have necessary containment and spill kits at handling place.
Process
a. Begin transfer process.
b. Discontinue operations if a spill level occurs.
c. Disconnect and store handling equipment.
Clean-up/Follow-up
a. Clean up spills with proper material.
b. Dispose of contaminated material at appropriate facility.
Documentation
a. Report spills to duty officer.
b. Complete paperwork.
The City of Medina shall conduct an annual assessment of the operations and maintenance program to
evaluate program compliance, the status of achieving the measurable requirements (activities that must
be documented or tracked as applicable to the MCM (e.g., inventory, trainings, inspections, maintenance
activities, etc.)) in Section 21, and determine how the program might be improved. The City must
perform the annual assessment prior to completion of each annual report and document any
modifications made to the program as a result of the annual assessment.
Managing Stormwater Sediment Best
Management Practice Guidance for
Municipalities
June 2012
Minnesota Pollution Control Agency
520 Lafayette Road North | Saint Paul, MN 55155-4194 | www.pca.state.mn.us | 651-296-6300
Toll free 800-657-3864 | TTY 651-282-5332
This report is available in alternative formats upon request, and online at www.pca.state.mn.us
wq-strm4-16
The MPCA is reducing printing and mailing costs
by using the Internet to distribute reports and
information to wider audience. Visit our website
for more information.
MPCA reports are printed on 100% post-consumer
recycled content paper manufactured without
chlorine or chlorine derivatives.
Contents
Stormwater Sediment Best Management Practices ..................................................................................... 1
Background ............................................................................................................................................ 1
Sediment removal cost ............................................................................................................................ 2
Stormwater sediment removal process ................................................................................................... 3
References .............................................................................................................................................. 7
Appendix A: Sediment Sampling and Analytical Technical Guidance ................................................. A-1
Attachment 1. Data quality indicators ........................................................................................... A-10
Appendix B: Technical Guidance for Calculation of Benzo[a]pyrene Equivalents and Comparison of
Chemical Concentrations to Soil Reference Values ................................................................................ B-1
Managing Stormwater Sediment BMP Guidance for Municipalities • June 2012 Minnesota Pollution Control Agency
1
Stormwater Sediment Best Management Practices
These stormwater sediment best management practices (BMPs) provide guidance for the removal of
sediment from stormwater collection and conveyance systems. This guidance document will help you
think through important steps associated with sediment removal projects. These may include:
· Who is responsible for managing stormwater sediment
· Land use within a drainage area
· Sampling sediment and what laboratory analysis is required
· How to calculate benzo[a]pyrene (B[a]P) equivalents for carcinogenic polycyclic aromatic
hydrocarbons (cPAHs)
· Management requirements for contaminated sediment
· Where contaminated stormwater sediments are accepted for disposal
· Who to contact if you have questions
This document is intended to help those responsible for operation and maintenance of stormwater
systems determine when sediment removal is needed, and what steps to consider during the course of
managing a sediment removal project. This is guidance. It is not a comprehensive list of everything you
may need to do when managing a sediment removal project. Other considerations may also include:
· Geographic or environmental sensitivities
· Landscape variations, and soil types
· Management of native or invasive species
· A wide range of variables that may be encountered from one municipality to the next, or one
project to the next
This guidance was developed to give local units of government, and others responsible for managing
stormwater collection and conveyance systems, a big picture understanding about how to manage
sediment removal projects and what you may need to consider before, during, and after a project.
This guidance was developed with special assistance from the cities of Burnsville, Circle Pines,
Maplewood, Roseville, St. Paul, White Bear Lake, and Woodbury, Minnesota.
Background
Action was taken during the 2009 Minnesota legislative session which included funding to conduct
research on stormwater pond sediment contamination and to help Minnesota cities clean-out
stormwater contaminated ponds. (House File Number 1231 Passed by the Minnesota Legislature on May
18, 2009 and Approved by Governor Tim Pawlenty on May 22, 2009.)
Research concluded that polycyclic hydrocarbons (PAHs) are often responsible for the greatest
contamination problems in stormwater pond sediment. PAHs persist in the environment and pose a risk
to animals, plants, and people at elevated concentrations. These contaminants are formed by the
incomplete combustion of organic materials, such as wood, oil, and coal, as well as occurring naturally in
crude oil and coal (Crane et al. 2010). Coal tar-based sealants are a major source of PAHs in urban
sediments (Mahler et al. 2012). The Minnesota Pollution Control Agency’s (MPCA) research determined
that coal tar-based sealants were the most important source of PAHs (58.2 percent), followed by oil-
based PAHs (15.0 percent) and vehicle emission sources (14.7 percent).
The legislation also provided funding for municipalities who agree to pass ordinances banning or
restricting the use of coal tar-based sealants; as of June 2012, 20 municipalities have passed such
ordinances (http://www.pca.state.mn.us/index.php/view-document.html?gid=16180).
Managing Stormwater Sediment BMP Guidance for Municipalities • June 2012 Minnesota Pollution Control Agency
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The 2009 legislation also directed the MPCA to develop BMPs to avoid or mitigate impacts of PAH
contamination from coal tar-based sealants. The MPCA provides guidance for the operation and
maintenance of stormwater conveyance and collection systems. Stormwater collection and conveyance
systems are commonly referred to as stormwater ponds, stormwater control devices, wet detention
basins, or National Urban Runoff Program (NURP) ponds.
This document provides guidance for sediment removal projects from stormwater ponds of any sort.
Sediment may also be generated in other stormwater devices such as sumps, traps, pipes, or other
conveyance structures. This guidance may be adapted for other situations to determine representative
concentrations of contaminants of potential concern. The analytical component outlined in Appendix A
may be applied to other sediment sampling situations, but the MPCA does not have specific sampling
guidance at this time for those situations and it is not necessary to follow this guidance for other types
of sediment removal projects. The sampling guidance provided in Appendix A is strictly for sampling
sediment from stormwater ponds.
These BMPs will continue to be updated to include new information and data about stormwater
sediment and will be incorporated as a chapter in the MPCA Stormwater Manual once updates to the
manual are completed. The MPCA Stormwater Manual can be found on the MPCA website at:
http://www.pca.state.mn.us/index.php/view-document.html?gid=8937.
Sediment removal cost
The high cost to manage contaminated stormwater sediment has brought operation and maintenance
of stormwater ponds into the public spotlight. Unregulated sediment can be managed locally and
without disposal restrictions that make them far less costly to manage. Disposal costs for a stormwater
sediment removal project can be as much as three times more expensive depending on the type and
level of contamination in the sediment. This emphasizes the value and importance of source control to
reduce the loading of contamination into stormwater ponds.
Stormwater collection systems concentrate pollutants by design. These systems include:
· Wetlands converted for the specific purpose of conveying, treating, or otherwise managing
stormwater
· Ponds, or small lakes which have been designated for the specific purpose of conveying, treating,
or otherwise managing stormwater
· Structures engineered, built, constructed, and/or man-made devices for the specific purpose of
conveying, treating, or otherwise managing stormwater.
Stormwater collection systems are intended to help protect infrastructure from flooding and to collect
and concentrate pollutants to prevent them from reaching lakes, rivers, streams, wetlands, and other
waters of the state where they could have a negative effect on water quality, aquatic animals, or human
health. Managing contamination and pollutants in the sediment of stormwater collection systems
should be expected. “Sampling is conducted to guide proper management of contaminated sediment”.
Managing Stormwater Sediment BMP Guidance for Municipalities • June 2012 Minnesota Pollution Control Agency
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Stormwater sediment removal process
1. Inventory and maintenance needs
2. Evaluating and testing sediment
3. Engineering, contracting, and work plans
4. Excavating sediment
5. Site restoration
6. Records and documentation to keep on file.
1. Inventory and maintenance needs
Assessing need and planning sediment removal projects includes a number of steps that range from
estimating lost capacity to notifying neighbors about plans to maintain the stormwater collection
system. For municipalities who are managing dozens, or sometimes hundreds of stormwater ponds,
starting with an inventory and a maintenance prioritization process is recommended.
Some municipalities find it helpful to develop a flowchart or other prioritization scheme to triage
and track priority sediment removal projects. Topics of importance may include:
· Priorities identified by city inspections – sediment level, lost capacity, other needs.
· Natural wetland verses constructed ponds. Constructed ponds come first.
· Accessibility. Does the city already have access via parkland, easement, or outlot?
· What are the sediment analysis results? Can the city afford to remove and manage the
sediment?
· Is the downstream lake or sub-watershed a priority?
· What is the expected cost/benefit from the project?
· Can a stormwater pond be expanded to provide greater benefit?
· Is surveying needed to assess lost capacity and depth of excavation?
· How will you measure or estimate the volume of cubic yards of sediment to be removed?
· Have sediment deltas and inlet/outlet structures been identified/located?
· Where are your access points for machinery?
· Are communications with other stakeholders important/public relations?
· Are visual inspections, notes, checklists, or photos to track maintenance projects needed?
The first phase of work identifies need and determines if a sediment removal project is even
necessary. This may include a preliminary survey to gage sediment depth and provide a rough
estimate of the number of cubic yards of sediment to be removed. This assessment and planning
will help guide work plan development and contracting if a sediment removal project is deemed
necessary.
2. Evaluating and testing sediment
Collecting sediment samples and testing sediment helps characterize what contaminants are
present. This step helps identify contaminants of potential concern and what management options
are available. Sampling results limit where sediment can go and this affects work plan development
including contract specifications for bidding projects. This is a very important part of the
management process. This guidance is summarized in the following appendices:
· Guidance for collecting samples and testing sediment are outlined in Appendix A.
· Guidance for calculating B[a]P equivalents and comparing chemical concentrations to Soil
Reference Values are summarized in Appendix B.
Managing Stormwater Sediment BMP Guidance for Municipalities • June 2012 Minnesota Pollution Control Agency
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Knowledge about land use categories in the watershed will help with subsequent steps in this
process. In urban areas, the following land uses are of greatest interest for stormwater collection
systems:
· Residential
· Commercial
· Industrial
Residential land uses range from low density (houses are on lots of more than an acre) to high
density (multiple-unit structures such as apartments and condominiums). Residential areas
generally have a uniform size and spacing of structures, linear driveways, and lawn areas. Most
churches and small schools are included in this category, too (Anderson et al. 2001).
Commercial land uses include areas where products are sold and services are provided. These
land uses include urban central business districts, shopping centers, commercial strip
developments, junkyards, and resorts. Institutional land uses such as larger educational,
religious, health, correctional, and military facilities are included in this category, too. Office
buildings, warehouses, driveways, sheds, parking lots, landscaped areas, and waste disposal
areas supporting the basic uses are included in commercial land uses (Anderson et al. 2001).
Industrial land uses range from light manufacturing to heavy manufacturing plants. Light
industries design, assemble, finish, process, and package products, while heavy industries use
raw materials such as iron ore, timber, or coal (e.g., steel mills, pulp and lumber mills, electric
power generating stations, oil refineries and tank farms, contaminant plants, and brick making
plants). Industrial land uses may include buildings, parking lots, loading docks, access roads,
processing facilities, stockpiles, storage sheds, and numerous vehicles (Anderson et al. 2001).
It is the responsibility of the owner or responsible party to evaluate the drainage area of each
stormwater collection system to determine whether spills, improper disposal, or the potential
for a release from commercial or industrial operations indicate that sampling for other
contaminants are needed. For example, if sediment is being removed from a pond in an
industrial park and there has been a release of contaminants known to accumulate in sediments
(like nickel and silver from a metal plating facility), then the owner or responsible party should
include those contaminants on the list for sampling.
Laboratory analysis is required to determine management or treatment options. Guidance for
collecting samples and testing sediment are described in Appendix A.
Management options include:
1. Unregulated fill. Laboratory analysis determines that contaminants of potential concern
are below levels that require special management. Excavated sediment can be managed in
accordance with the MPCA's BMP for the Off-Site Use of Unregulated Fill.
http://www.pca.state.mn.us/index.php/view-document.html?gid=13503.
2. Regulated solid waste. Laboratory analysis determines that contaminants of potential
concern in the stormwater sediment require special management and cannot be used as
clean fill.
Contaminated sediment is currently guided to a landfill if it cannot be used as a clean fill. Depending
on the types and concentrations of contaminants; sediment may need to be disposed of at a
Municipal Solid Waste (MSW) landfill that has an industrial solid waste management plan. This
means contaminated sediment must go to a MSW landfill that has a liner and a leachate collection
system.
Managing Stormwater Sediment BMP Guidance for Municipalities • June 2012 Minnesota Pollution Control Agency
5
MSW landfills in Minnesota that can accept these types of waste can be found on this webpage:
http://www.pca.state.mn.us/veiz806 or, the list can be accessed directly at this link:
http://www.pca.state.mn.us/index.php/view-document.html?gid=12806.
Some additional landfills that are permitted to accept industrial waste, and which may also accept
contaminated stormwater sediments, include:
1. Voyageur Industrial Landfill in Cannon Falls, Minnesota
2. Vonco II Landfill in Becker, Minnesota
3. Vonco V Landfill in Duluth, Minnesota
4. Shamrock Environmental Landfill in Cloquet, Minnesota
5. Dem-Con Landfill in Shakopee, Minnesota
6. Veolia E S Rolling Hills Landfill in Buffalo, Minnesota
7. SKB Rosemount Industrial Waste Facility in Rosemount, Minnesota
It is recommended that you contact the facility to ensure they will be able to accept your waste and
to determine what sampling requirements are required by the facility.
3. Engineering, contracting, and work plans
Work plan development includes a wide range of logistics including, but not limited to:
· Notification of residents and neighbors.
· How to access the site and what machinery will be needed to remove sediment.
· Define how sediment will be removed, measured, and paid for.
· Testing or analysis requirements for the destination disposal or treatment facility.
· Plans for erosion control.
· Tree removal, environmental impact, depth to ground water, and risks associated with the
displacement of wildlife or invasive species.
· Lack of design and/or construction documentation (no “as-built” records).
· Estimating water draw-down needs and the amount of time and oversight needed to drain
the stormwater collection system.
· What permits (if any) may be required by your local watershed district, county, or the
Department of Natural Resources. The MPCA does not require a permit or notification for
routine maintenance of stormwater ponds, but cities are advised to keep records and
documentation of their sediment removal projects as outlined in this guidance.
· Defining appropriate BMPs for dewatering (e.g., rock riprap, sand bags, plastic sheeting, or
other accepted energy dissipation measures), such that the discharge does not adversely
affect the receiving water or downstream landowners.
· Ensuring that water from pumping or draw-down activities is discharged in a manner that
does not cause nuisance conditions, erosion in receiving channels, or erosion on down-slope
properties. This also includes inundation of wetlands causing significant and/or adverse
impact. The general rule of thumb is “keep it clear”.
· How sediment will be transported and a process to track the volume of sediment removed.
· Defining logistics, administrative, and engineering requirements, surveys, dewatering
processes, site access and easements, rock entrance and off-site tracking needs,
coordination with adjacent cities, and/or watershed districts and the Minnesota
Department of Transportation.
Managing Stormwater Sediment BMP Guidance for Municipalities • June 2012 Minnesota Pollution Control Agency
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4. Excavating sediment
Sediment excavation projects are recommended to take place during the winter. Benefits include:
· Winter excavations greatly reduce the risk that rain may cause flooding and erosion of
dewatered ponds, or turbid runoff conditions.
· Access with trucks and heavy machinery is easier in the winter when soil surrounding
stormwater ponds freezes solid.
· Adjacent residents and neighbors have windows closed and this means less noise, less dust,
less odor, and fewer disturbances overall.
· Water can be pumped down so remaining water can freeze solid. Pumping should be
discontinued before the bottom of the pond is disturbed and sediment is stirred up making
the water turbid. Remaining water should be allowed to freeze solid trapping any
suspended sediment in ice. The ice can then be skimmed off with a bulldozer so it can be
piled within the pond. This keeps turbid water in the basin after snow and ice melt during
spring thaw.
Winter excavation projects also have a few drawbacks. They include:
· Shorter working days
· Problems associated with working in freezing conditions and sub-zero weather
· The use of lights after dark to extend the work day
Sediment removal can begin once snow and ice have been skimmed off and piled within the pond.
A more precise survey is usually conducted at this time to better estimate the amount of sediment
to be removed and to identify the depths of excavation to achieve a final grade that restores desired
capacity.
If the removal volume is not defined by survey, then establishing a standard volume per truck and
counting the number of trucks leaving the site can be used to track the volume in cubic yards.
Once sediment is removed, final grading should achieve a natural (gradual) slope for all banks. Ice
and snow that has been stockpiled in the pond should be evenly distributed throughout the basin
once sediment has been removed. This will allow water and remaining sediment to be retained in
the pond. Temporary stabilization of slopes and banks should ensure control of erosion and prevent
site run-off during spring snowmelt and the first rain events of the season. Clean-up and removal of
temporary infrastructure should be done working your way out of the site. Once you remove
equipment and temporary infrastructure (such as transport roads and rock entrances), it will be cost
prohibitive and essentially impossible to make additional corrections.
5. Site restoration
Site restoration work should be conducted as soon as weather conditions permit and may include:
· Additional clean-up or maintenance of inlet and outlet structures
· Additional site stabilization work including sediment and erosion control
· Establishing plants, seed, sod, mulch, or vegetation to prevent erosion (above water line)
· Professional engineer sign-off on project completion.
Managing Stormwater Sediment BMP Guidance for Municipalities • June 2012 Minnesota Pollution Control Agency
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6. Records and documentation to keep on file
It is important to keep good records about the operation and maintenance of stormwater collection
systems. Good records will not only assist with an accurate inventory and triage of stormwater
ponds, but they can also provide the basis for sound planning in the future. Important records and
documentation for sediment removal projects may include:
· Date of excavation
· Amount removed
· Laboratory results
· Place of disposition
· “As Built” prints or plans if they exist
· Contractor information, shipping papers/manifests/contractual agreements
· Any other observations about the removal that will help the city operate and maintain
that site in the future.
For more information on PAH-contaminated stormwater sediment, or information about
stormwater best management practices, contact Don Berger at 651-757-2223 or e-mail to:
donald.berger@state.mn.us.
References
Anderson, J.R., E.E. Hardy, J.T. Roach, and R.E. Witmer. 2001 (first printing 1976). A land use and land
cover classification system for use with remote sensor data. Appendix C: Land use definition. U.S.
Geological Survey. Geological Survey Professional Paper 964.
(http://www.usbr.gov/lc/socal/reports/SMappend_C.pdf)
Crane, J.L., K. Grosenheider, and C.B. Wilson. 2010. Contamination of stormwater pond sediments by
polycyclic aromatic hydrocarbons (PAHs) in Minnesota. The role of coal tar-based sealcoat products as a
source of PAHs. Minnesota Pollution Control Agency, St. Paul, Minnesota. MPCA document # tdr-g1-07.
(http://www.pca.state.mn.us/index.php/view-document.html?gid=12960)
Mahler, B.J., P.C. Van Metre, J.L. Crane, A.W. Watts, M. Scoggins, and E.S. Williams. 2012. Coal-tar-based
pavement sealcoat and PAHs: Implications for the environment, human health, and stormwater
management. Environ. Sci. Technol. 46:3039-3045. (http://pubs.acs.org/doi/pdf/10.1021/es203699x)
Managing Stormwater Sediment BMP Guidance for Municipalities • June 2012 Minnesota Pollution Control Agency
A-1
Appendix A: Sediment Sampling and Analytical Technical Guidance
This technical guidance should be shared with the staff or environmental consultants responsible for
sampling sediments and interpreting the analytical results for the owner or responsible party. It is the
responsibility of the owner or responsible party to either train their staff or select consultants who can
perform these tasks.
Sediment sampling
The U.S. Environmental Protection Agency’s report on “Methods for Collection, Storage and
Manipulation of Sediments for Chemical and Toxicological Analyses: Technical Manual” (USEPA 2001)
provides guidance on sediment monitoring plans, collection of whole sediments, field sample
processing, transport and storage of sediments, sediment manipulations, and quality assurance/quality
control (QA/QC) issues. This report should be used as a resource by owners or responsible parties, and
their consultants, for sampling and processing stormwater pond sediments. In particular, this user-
friendly document provides pictures of sediment sampling equipment, flowcharts for making decisions,
check lists, and boxes of important bulleted items.
Sediment characterization
Stormwater pond sediments are very complex, and chemical results can vary greatly within a few yards
of each sample. This feature makes it more difficult to provide generic guidance for a broad suite of
stormwater ponds. The ponds themselves may differ based on whether the pond originated as a natural
feature or was constructed for the purpose of stormwater management. These ponds also vary in size
and shape, and some ponds may have multiple inlets and outlets. Finally, the type of land uses in the
drainage areas of the ponds can influence contaminant concentrations in the pond sediments. Based on
the MPCA’s 2009 stormwater pond study (Crane in review), coal tar-based sealant sources comprised 58
percent of total PAHs (based on a suite of 34 PAHs) in surface sediments of ponds located primarily in
residential, commercial, and industrial land use areas. Watersheds where coal tar-based sealants are
used on driveways and parking lots will have higher concentrations of PAHs in nearby stormwater pond
sediments than those that use either asphalt-based sealants (which have much lower concentrations of
PAHs), no sealant, or use other material such as concrete, permeable pavers, or gravel for driveways and
parking lots.
What’s New?
· The number of sediment samples to be collected now depends on the surface area of the
stormwater pond instead of the volume of material to be excavated from the pond.
· For the analysis of polycyclic aromatic hydrocarbons (PAHs) from sediment samples,
analytical laboratories must use clean-up columns (instead of only diluting the sample
extract) to remove interferences from the sample extract. This will result in lower reporting
limits and better data for making management decisions.
· The MPCA has reduced the number of carcinogenic PAHs (cPAHs) to be measured in
sediment samples from 25 to 17 compounds.
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The MPCA is requiring owners or responsible parties to sample sediments prior to dredging to
determine concentrations of 17 cPAHs, noncarcinogenic PAHs, arsenic, and copper. Analysis of sediment
samples for particle size and total organic carbon (TOC) is optional, but this information may be useful
for some beneficial reuse scenarios of the dredged material. If the owner or responsible party is aware
of other known or suspected sources of contamination, they should collect sufficient volumes of
sediment samples to have other parameters evaluated. The analytical laboratory will provide guidance
on how much sediment is needed for each analysis. Since it can sometimes take several months from
the time field sampling is conducted to when the analytical results become available for assessing
management options, the field sampling needs to be conducted early on in the process after conducting
an inventory of stormwater ponds and determining maintenance needs.
If the annual volume of sediment to be removed is less than 100 cubic yards, such as from a sump or
forebay area near a pond inlet or outfall, then no chemical testing or other sediment characterization is
required. The owner or responsible party is responsible for the due diligence in the reuse and/or
disposal of this material. When more than 100 cubic yards of sediment need to be removed, some
important general guidance for characterizing sediment is as follows:
· Sampling should be to the planned depth of excavation or greater. The MPCA has provided
previous guidance to collect sediment samples in two foot intervals (e.g., 0 – 2 ft, 2 - 4 ft), but it
is up to the owner or responsible party to collect sediment samples that will cover the depth to
be dredged. If it is easier in the field to collect two foot depth intervals, then by all means
continue to do this. The important issue is to send a sediment sample to the analytical
laboratory that is representative of the entire depth interval to be excavated. Since collecting
sediment from two or more long (2 ft) cores may entail a large mass of sediment, it may be
easier to slice the core from top to bottom and only analyze half of the slice; this slice can be
combined with a deeper layer slice to provide one composite sample for the analytical
laboratory to analyze. It is not acceptable to randomly scoop out bits of sediment from different
portions of the sediment core to composite together since doing so may miss out on the
historical record of sediments (and contaminants) deposited in different depth intervals.
· Core samplers are more appropriate to use to obtain cohesive sediment samples at depth than
grab samplers. Grab samplers can be used to collect surface samples if the sediment samples
are too floccy (loose) with vegetative detritus (e.g., parts of cattail stalks/leaves) or are too
sandy to be retained in a core sampler.
· Geopositional coordinates need to be collected at the location of each sample site.
· The number of samples to be collected depends on the surface area of the pond. [Note: this is a
change in policy from previous MPCA guidance (Stollenwerk et al. 2011) that recommended
the number of samples per the estimated volume of dredge material.] The goal is to collect
sediment samples that are representative of the material that will be removed to maintain the
functionality of the stormwater pond.
o Multiple samples need to be collected, particularly since some compounds may be not
be detected in all areas of the pond.
o For stormwater ponds with a surface area less than or equal to one acre, at least two
stations need to be sampled for chemical analysis. Sample sites may either be selected
randomly or by a transect from the main inlet to the outlet of the pond.
o For ponds greater than one acre and less than four acres, one sampling station should
be located in each acre and portion of an acre of the pond. In some cases, multiple
samples may need to be collected at the same station and composited together to
provide an adequate mass of sediment for the analytical work. Sample sites may either
be selected randomly or in a transect from the main inlet to outlet of the pond.
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o For ponds larger than four acres, divide the pond into four sections (quadrants) as
shown in Figure A-1. Select at least five sites (i.e., subsamples) within each quadrant
using either the dice pattern shown in Figure A-1 or using a random sampling strategy.
Sediment from each subsample needs to homogenized (mixed well) in a precleaned
container (large 4 L Pyrex mixing cups work well; larger volumes can use precleaned
buckets). An equal aliquot of sediment from each subsample is then composited
together to form the sediment sample for that quadrant that is submitted to the
analytical laboratory.
o For natural ponds larger than 4 acres that have an irregular shape, such as bays off the
main pond, each bay should be sampled if it is targeted for dredging. Depending on the
size of the bay, use the aforementioned guidance for developing a sampling plan.
o If more than 10 samples are collected for analysis (possibly from a study of multiple
ponds during the same time period), a field replicate sample needs to be collected for
every 10 samples (i.e., 10% of samples). A field replicate is collected in close proximity
to the other sample and provides a measure of field precision.
· Remove any rocks, pebbles, trash, large invertebrates (like beetles), or large pieces of detritus
from each subsample and composite sample.
· Overlying water needs to be decanted from the subsamples and composite sediment sample in
the field prior to splitting the sample into the sample jars.
· Sediment samples need to be homogenized (mixed well) before splitting the sample into
precleaned jars for the PAH and metals analyses. Most analytical laboratories will provide
precleaned jars and sample labels for their clients. It is important with PAHs to use amber,
pesticide-grade, precleaned glass jars with Teflon™-lined lids since PAHs may be degraded by
sunlight. Use a permanent marker to fill out the sample label; it is helpful to wrap clear packing
tape around the label to secure it on the jar since sometimes the labels can come loose while
the sample jars are stored on ice during field sampling.
· Store the sediment samples on ice (or ice packs) in a cooler during field sampling. Next, either
transfer the samples directly to the analytical laboratory or store them in an interim refrigerator
or freezer prior to submitting to the laboratory. If the sediment samples are to be frozen, make
sure the sample jars are not filled more than two-thirds full to allow room for expansion while
the sediment freezes.
Submit samples to analytical laboratories
The following steps need to be completed before the sediment samples are ready to submit to the
analytical laboratory:
· After the sediment has settled in the sample jars in the refrigerator, additional overlying water
should be carefully removed prior to submitting the samples to analytical laboratories. Use of a
pre-cleaned, wide-bore pipette to remove overlying water is better than decanting the sample
since it will not disturb the sediment as much in the jar. If the laboratory receives sediment
samples that have a high water content, then there may not be enough mass of sediment
available to do their analyses. If the sediments are “soupy” or have a lot of plant detritus (such
as from cattails), then it would be a good idea to submit extra sediment to the laboratory.
· Provide the analytical laboratory with recommendations on which sample(s) would make good
candidate Matrix Spike/Matrix Spike Duplicate (MS/MSD) samples for the cPAH analysis. This is
important since the laboratory receives a subset of the sample collected and does not have the
field sampling observations the field sampling crew had with collecting the larger sample. If
guidance is not provided and the laboratory ends up selecting a sediment sample high in PAHs
(as occurred with the MPCA’s stormwater pond study), the results of the MS/MSD will not be
useable and the client will still be charged for this analysis. Good candidate samples would
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be expected to have lower concentrations of PAHs so that the spike level will be at least five
times greater than the background sample. Avoid designating samples that have strong
petroleum odors, have an oil sheen overlying the sediment, or are dark black and oily in
appearance since these samples are likely to have high concentrations of PAHs.
· Sample tracking forms or chain-of-custody forms are helpful to use during field sampling to
record observations about the sediment samples and to provide field sampling information
(e.g., sample station, date, time, sampling equipment, analyses to be done). Most analytical
laboratories will provide their clients with a chain-of-custody form; provide a copy to the
analytical laboratory when the samples are submitted or shipped to them.
Analytical considerations
This guidance may be updated in the future as new screening and analytical methods become available.
Preparation
Laboratories that freeze dry the sediment samples prior to extraction and analysis for PAHs and metals,
as well as other contaminants of potential concern, reduce or eliminate the problems of wet samples.
These laboratories are also able to achieve lower detection limits and more quantitative determinations.
Freeze drying of the sample also allows for complete homogenization of the sample matrix, which will
result in improved precision. Although not a requirement, better results may be obtained using this
preparation method.
How to Select an Analytical Laboratory:
1. If the municipality is a Cooperative Purchasing Venture (CPV) member, they can access
the State of Minnesota’s Sampling and Laboratory Services contract to obtain State-
negotiated contract prices. If needed, assistance in accessing the contract is available
from Martina Cameron (MPCA) at: martina.cameron@state.mn.us or 651-757-2259. If
assistance is needed to find a contract laboratory capable of performing cPAH analyses,
then contact Bill Scruton (MPCA) at: bill.scruton@state.mn.us or 651-757-2710.
2. If the municipality is not currently a CPV member but would like to become one, sign-
up for this program from the Minnesota Department of Administration’s website at:
http://www.mmd.admin.state.mn.us/cpvfaqs.htm#M. There is no charge to sign-up,
and it is open to all municipalities.
3. If the municipality wants to find a commercial laboratory for cPAHs without using the
State contract, go to the following link for the Minnesota Department of Health’s
Certification website to find a laboratory certified for this analysis in Minnesota:
https://apps.health.state.mn.us/eldo/public/accreditedlabs/labsearch.seam. From this
website, click on the “customized searches” tab. At the Program drop down arrow, click
on “Resource Conservation Recovery Program.” Next, click “search” at the bottom of
the page. Click “view” on the right-hand side of the page in line with the laboratory
contact information to scroll down the list of laboratory capabilities. Look for RCRA
method 8270D SIM. The Minnesota Department of Health does not actually certify
laboratories for either the cPAH method or the extra PAHs beyond the U.S.
Environmental Protection Agency (EPA) list of 16 priority pollutant PAHs. The
municipality should ask the laboratory if they do the cPAH list, also known as the
Minnesota Extended List of PAHs.
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Analytical methods
The primary analytical methods are provided below:
· The extended list of PAHs, including 17 cPAHs (Table A-1) and noncarcinogenic PAHs, must be
analyzed based on EPA Method 8270 by gas chromatography/mass spectrometry (GC/MS) with
selective ion monitoring (SIM) as optional.
o Since sediments from stormwater ponds usually contain interfering compounds, it is
required that the analytical laboratory run the sample extracts through clean-up
columns, rather than just diluting the sample extract to reduce interfering compounds.
An example clean-up process is to pass the sample extract through an alumina (and/or
silica gel) column to isolate the hydrocarbon fraction. A layer of activated copper can be
added to the bottom of the column or to the sample extract to remove any sulfur that
may have been present in the samples. Note that 14 cPAHs were detected in the
MPCA’s study of stormwater pond sediments (Crane in review), and either more cPAHs
or a greater percentage of cPAHs may have been detected if the local laboratory had
used clean-up columns instead of diluting the sample extracts (Table A-2). These results,
in addition to other factors described in Table A-2, were used to shorten the list of
cPAHs from 25 to 17 compounds.
o The analytical laboratory must be asked to note J-flagged data that are in-between the
method detection limit and the reporting limit.
· Metals should be analyzed by inductively coupled plasma—mass spectrometry (ICP—MS) using
reference method SW 6020. Occasionally, confirmation of the metal may be needed using
graphite furnace atomic absorption spectrophotometry.
· Percent moisture should be determined using reference method ASTM D2216.
· Total organic carbon (TOC), if needed, can be analyzed using EPA method 9060a.
· Particle size, if needed, can be analyzed multiple ways to determine percent sand, silt, and clay.
QA/QC data quality indicators
The field sampling procedures and analytical methods include several QA/QC measures to ensure
useable data are collected and measured. In particular, data quality indicators (DQIs) are qualitative and
quantitative descriptors used in interpreting the degree of acceptability or utility of data. The principal
DQIs are precision, bias, representativeness, comparability, and completeness; these terms are
described further in Attachment 1. Establishing acceptance criteria for the DQIs sets quantitative goals
for the quality of data generated in the analytical measurement process.
· For cPAHs and noncarcinogenic PAHs by EPA Method 8270, the DQIs are:
o Blanks: <5 times the method detection limit (MDL); procedural blanks should be
prepared with each analytical batch.
o Surrogate Recovery: 40-120% the recovery of the surrogate compounds are used to
measure data quality in terms of accuracy (extraction efficiency).
o Laboratory Control Sample (LCS) and Matrix Spike (MS) Recovery: 40-120%; the percent
recoveries of target analytes are calculated to measure data quality in terms of accuracy
o MS/Matrix Spike Duplicate (MSD) Precision: relative percent difference (RPD) <30%;
this is used to evaluate the data in terms of precision.
o Reporting Limit of 10-30 µg/kg dry weight for individual PAH compounds.
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· For metals (arsenic and copper):
o Blanks: <5 times the MDL; procedural blanks should be prepared with each analytical
batch.
o Precision (% RPD): <10%
o Accuracy: 85 – 115%
o Reporting Limit: 0.10 mg/kg dry wt.
Electronic data requirements
· Electronic copies of the data should be obtained from the analytical laboratory in spreadsheet
format (e.g., Microsoft Excel).
· In the future, the MPCA may be interested in obtaining electronic copies of the analytical results
for archiving it in the MPCA’s database system. At the present time, though, the MPCA’s
database platform, EQuIS, is not set-up to accommodate sediment chemistry data
References
Crane, J.L. in review. Source apportionment of PAHs and risk considerations in urban stormwater pond
sediments in the Upper Midwest USA. Submitted to a peer-reviewed journal on May 8, 2012.
Stollenwerk, J., J. Smith, B. Ballavance, J. Rantala, D. Thompson, S. McDonald, and E. Schnick. 2011.
Managing dredged materials in the State of Minnesota. Minnesota Pollution Control Agency, St. Paul,
MN. MPCA document number wq-gen2-01. http://www.pca.state.mn.us/index.php/view-
document.html?gid=12959.
USEPA. 2001. Methods for collection, storage and manipulation of sediments for chemical and
toxicological analyses: Technical manual. U.S. Environmental Protection Agency, Office of Water,
Washington, DC. EPA-823-B-01-002 (http://water.epa.gov/polwaste/sediments/cs/collection.cfm).
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Figure A-1. Sediment sampling scheme for a stormwater pond greater than four acres in size.
Quadrant #1 Quadrant #3
Quadrant #2 Quadrant #4
Inlet
Outlet
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Table A-1. List of PAHs to be Analyzed in Stormwater Pond Sediments
PAH Compounds Included in EPA
Method 8270
cPAHs
U.S. EPA Group B2 Probable Human
Carcinogens
Acenaphthene
Acenaphthylene
Anthracene
Benzo[a]anthracene X X
Benzo[a]pyrene X X
Benzo[b]fluoranthene X
Benzo[j]fluoranthene X X
Benzo[e]pyrene
Benzo[g,h,i]perylene
Benzo[k]fluoranthene X X
Benzofluoranthenes (Total)
Carbazole
2-Chloronaphthalene
Chrysene X X
Dibenz[a,h]acridine X
Dibenz[a,h]anthracene X X
Dibenzo[a,e]pyrene X
Dibenzo[a,h]pyrene X
Dibenzo[a,i]pyrene X
Dibenzo[a,l]pyrene X
7H-Dibenzo[c,g]carbazole X
Dibenzofuran
7,12-Dimethylbenz[a]anthracene X
Fluoranthene
Fluorene
Indeno[1,2,3-cd]pyrene X X
3-Methylcholanthrene X
5-Methylchrysene X
1-Methylnaphthalene
2-Methylnaphthalene
Naphthalene
Perylene
Phenanthrene
Pyrene
Note: A combination of benzo[b]fluoranthene, benzo[j]fluoranthene, and/or benzo[k]fluoranthene frequently coelute
together when sediments are analyzed.
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Table A-2. Percent of Detected cPAHs in a MPCA Study of Metro Area Stormwater Ponds (Crane in review)*
Parameter # of Detects** % Detected
Chrysene 44 73.3
Benzo[b&j]fluoranthene 42 70.0
Benzo[a]pyrene 41 68.3
Indeno[1,2,3-c,d]pyrene 38 63.3
Benzo[a]anthracene 34 56.7
Benzo[k]fluoranthene 34 56.7
Dibenzo[a,e]pyrene 33 55.0
Dibenzo[a,i]pyrene 32 53.3
Dibenzo[a,h]pyrene 23 38.3
Dibenzo[a,h]anthracene 15 25.0
Dibenz[a,h]acridine 10 16.7
3-Methylcholanthrene 4 6.7
Dibenzo[a,l]pyrene 4 6.7
5-Methylchrysene 1 1.7
* Sediment samples were analyzed by a local commercial laboratory without using clean-up columns. Instead, the
sample extracts were diluted to remove chemical interferences. The reporting limits were elevated as a result of
diluting the sample extracts. A higher percentage of detected cPAHs probably would have been achieved if the
sample extracts had been run through clean-up columns.
** Results exclude field replicate data; n = 60 samples.
The following cPAHs were not detected in any samples: 1,6-Dinitropyrene, 1,8-Dinitropyrene, 1-Nitropyrene, 2-
Nitrofluorene, 4-Nitropyrene, 5-Nitroacenaphthene, 6-Nitrochrysene, 7,12-Dimethylbenz(a)anthracene, 7H-
Dibenzo(c,g)carbazole, and Dibenz(a,j)acridine.
Note: the MPCA evaluated this list of 25 cPAHs to determine if some of these cPAHs could be dropped from the
analytical list for stormwater pond sediments. As indicated in Appendix B, this list of 25 cPAHs was adopted from
an air quality program at California EPA. However, not all of these atmospheric cPAHs in California may be of
concern in stormwater pond sediments in Minnesota. The above data set was reviewed, in addition to the
percentage of detected cPAHs in other sediment data sets available to the MPCA (including some other metro-area
stormwater pond sediments and sites included under the MPCA’s Remediation Program). Additional input to the
MPCA’s evaluation came from recommendations from the Minnesota Department of Health for cPAHs to analyze
in stormwater pond sediments, as well as human health-based toxicity data, environmental fate information, the
results of the MPCA’s environmental forensic work to determine sources of PAHs in metro-area stormwater ponds
(Crane in review), and commercial production information. All of this information was used to shorten the list of
cPAHs from 25 to 17 compounds (Table A-1). As additional data become available, the MPCA will periodically
assess whether further changes are needed to this list.
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Attachment 1. Data quality indicators
This section is based on quality assurance/quality control (QA/QC) guidance provided by the U.S.
Environmental Protection Agency (USEPA 2002). Data Quality Indicators (DQIs) are qualitative and
quantitative descriptors used in interpreting the degree of acceptability or utility of data. The principal
DQIs are precision, bias, representativeness, comparability, and completeness. Establishing acceptance
criteria for the DQIs sets quantitative goals for the quality of data generated in the analytical
measurement process.
Precision
Precision is a measure of agreement among replicate measurements of the same property, under
prescribed similar conditions. This agreement is calculated as either the range (R) or as the standard
deviation (s). It may also be expressed as a percentage of the mean of the measurements, such as
relative percent difference (RPD) or relative standard deviation (RSD) (for three or more replicates).
Field precision is assessed through the collection and measurement of field replicates at a rate of one
replicate per ten analytical samples. This allows intralaboratory precision information to be obtained on
sample acquisition, handling, shipping, storage, preparation, and analysis. Both samples can be carried
through the steps in the measurement process together to provide an estimate of short-term precision.
An estimate of long-term precision can be obtained by separating the two samples and processing them
at different times or by different people and/or analyzed using different instruments.
For duplicate measurements, relative percent difference (RPD) is calculated as follows:
RPD = êD1 – D2ï x 100%
(D1 + D2)/2
RPD = relative percent difference
D1 = sample value
D2 = duplicate sample value
êD1 – D2ï = absolute value of the sample minus the duplicate sample values
For three or more replicates:
RSD = (s/x) x 100
RSD = relative standard deviation
s = standard deviation of three or more results
x = mean of three or more results
Standard deviation is defined as follows:
s = ((å(yi – mean y)2 x 1/(n-1)))0.5
s = standard deviation
yi = measured value of the ith replicate
mean y = mean of replicate measurements
n = number of replicates
Bias
Bias is the systematic or persistent distortion of a measurement process that causes errors in one
direction. Bias assessments for environmental measurements are made using personnel, equipment,
and spiking materials or reference materials as independent as possible from those used in the
calibration of the measurement system. When possible, bias assessments should be based on analysis of
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spiked samples rather than reference materials so that the effect of the matrix on recovery is
incorporated into the assessment. A documented spiking protocol and consistency in following that
protocol are important to obtaining meaningful data quality estimates. Spikes should be added at
different concentration levels to cover the range of expected sample concentrations. The use of spiked
surrogate compounds for GC/MS (SIM) procedures for PAH compounds are used to assess for bias.
Accuracy
Accuracy is a measure of the closeness of an individual measurement of the average of a number of
measurements to the true value. Accuracy includes a combination of random error (precision) and
systematic error (bias) components that result from sampling and analytical operations.
Accuracy in the field is assessed through the adherence to all sample handling, preservation, and holding
times. In order to assure the accuracy of the analytical procedures, an environmental sample will be
randomly selected from each sample shipment received at the laboratory, and spiked with a known
amount of the analytes to be evaluated. In general, a sample spike will be included in every set of 20
samples tested on each instrument. The spike sample will then be analyzed. The increase in
concentration of the analyte observed in the spiked sample, due to the addition of a known quantity of
the analyte, compared to the reported value of the same analyte in the unspiked sample determines the
percent recovery. The percent recovery for a spiked sample is calculated according to the following
formula:
%R = 100% x (S-U)/Csa
%R = percent recovery
S = measured concentration in spiked sample
U = measured concentration in unspiked sample
Csa = actual concentration of spike added
For situations where a standard reference material (SRM) is used in addition to a matrix spike:
%R = 100% x Cm/Csrm
%R = percent recovery
Cm = measured concentration of SRM
Csrm = actual concentration of SRM
Representativeness
Representativeness expresses the degree to which data accurately and precisely represents a
characteristic of a population, parameter variations at a sampling point, a process condition, or an
environmental condition. Representativeness is a qualitative term that should be evaluated to
determine whether in situ and other measurements are made and physical samples collected in such a
manner that the resulting data appropriately reflect the media and phenomenon measured or studied.
For field data, representativeness is dependent upon the proper design of the sampling program and
will be satisfied by ensuring that the field sampling plan is followed and that proper sampling techniques
are used.
Representativeness in the laboratory is ensured by using the proper analytical procedures, meeting
sample holding times, and analyzing and assessing laboratory duplicates for the chemistry samples.
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Comparability
Comparability is the qualitative term that expresses the confidence that two data sets can contribute to
a common analysis and interpolation. Comparability must be carefully evaluated to establish whether
two data sets can be considered equivalent in regard to the measurement of a specific variable or
groups of variables. In a laboratory analysis, the term comparability focuses on method type
comparison, holding times, stability issues, and aspects of overall analytical quantitation.
There are a number of issues that can make two data sets comparable, and the presence of each of the
following items enhances their comparability:
· Two data sets should contain the same set of variables of interest;
· Units in which these variables were measured should be convertible to a common metric;
· Similar analytical procedures and quality assurance should be used to collect data for both data
sets;
· Time measurements of certain characteristics (variables) should be similar for both data sets;
· Measuring devices used for both data sets should have approximately similar detection levels;
· Rules for excluding certain types of observations from both samples should be similar;
· Samples within data sets should be selected in a similar manner;
· Sampling frames from which the samples were selected should be similar; and
· Number of observations in both data sets should be of the same order or magnitude.
These characteristics vary in importance depending on the final use of the data. The closer two data sets
are with regard to these characteristics, the more appropriate it will be to compare them. Large
differences between characteristics may be of only minor importance, depending on the decision that is
to be made from the data.
Completeness
Completeness is a measure of the amount of valid data obtained from a measurement system compared
to the amount that was expected to be obtained under normal conditions. Field completeness is a
measure of the amount of valid measurements obtained from all the measurements taken in the
project. Field completeness for sampling stormwater ponds should be greater than 95%. Laboratory
completeness is a measure of the amount of valid measurements obtained from all the measurements
taken in the project. Laboratory completeness should be greater than 95% of the total number of
samples submitted to the analytical laboratories.
The calculation for percent completeness is as follows:
%C = 100% x (V/n)
%C = percent completeness
V = number of valid measurements
n = number of measurements planned
Reference
USEPA. 2002. Guidance for quality assurance project plans. U.S. Environmental Protection Agency, Office
of Environmental Information, Washington, DC. EPA/240/R-02/009. (http://www.epa.gov/quality/qs-
docs/g5-final.pdf)
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Appendix B: Technical Guidance for Calculation of Benzo[a]pyrene
Equivalents and Comparison of Chemical Concentrations to Soil Reference
Values
This technical guidance provides instructions for calculating benzo[a]pyrene (B[a]P) equivalents for
carcinogenic polycyclic aromatic hydrocarbons (cPAHs) and guidance for comparing all chemical data
from stormwater pond sediment samples to the MPCA’s Soil Reference Values (SRVs). Management
options for upland disposal of excavated sediment are discussed relative to the SRV values.
Calculating B[a]P equivalents
The Minnesota Department of Health (MDH) recommends evaluating the 25 cPAHs that the California
Environmental Protection Agency (Cal/EPA) has identified as being probable or possible human
carcinogens (Cal/EPA 1993, 2009; MDH 2001). Since toxicity data does not exist for all individual cPAHs,
they are evaluated according to how potent they are in relation to a reference contaminant, B[a]P.
Assuming B[a]P has a toxicity of one, other cPAHs are assigned a potency equivalency factor (PEF) to
indicate how toxic they are in comparison to B[a]P. Table B-1 lists B[a]P PEFs for 17 cPAHs to be
measured in stormwater pond sediments (see Appendix A, Table A-2 for additional explanation). This
section only pertains to cPAHs, which are evaluated by using B[a]P equivalents. Noncarcinogenic PAHs
are evaluated individually and are not included in the total B[a]P equivalent concentration.
Table B-1. B[a]P Potency Equivalency Factors (PEFs)
cPAH PEF cPAH PEF
Benz[a]anthracene* 0.1 Dibenzo[a,e]pyrene 1
Benzo[b]fluoranthene 0.1 Dibenzo[a,h]pyrene 10
Benzo[j]fluoranthene 0.1 Dibenzo[a,i]pyrene 10
Benzo[k]fluoranthene 0.1 Dibenzo[a,l]pyrene 10
Benzo[a]pyrene** 1.0 7,12-Dimethylbenzanthracene 34
Chrysene 0.01 Indeno[1,2,3-c,d]pyrene 0.1
Dibenz[a,h]acridine 0.1 3-Methylcholanthrene 3
Dibenz[a,h]anthracene 0.56 5-Methylchrysene 1
7H-Dibenzo[c,g]carbazole 1
*A common synonym for this compound is Benzo[a]anthracene
**Benzo[a]pyrene is the reference contaminant
Site sediment concentrations of individual cPAHs are multiplied by the corresponding PEF value in Table
B-1 to obtain an individual B[a]P equivalent concentration. These individual B[a]P equivalent
concentrations are summed for all cPAHs to arrive at a total B[a]P equivalent concentration that is
compared to the appropriate SRV value. The MPCA has developed an Excel file spreadsheet that users
can add their detected cPAH data to calculate B[a]P equivalents. The “BaP equiv. calculation” worksheet
is provided in the “Summary of Stormwater Pond Sediment Results” Excel file under the “Permit and
Program Forms” section of the Stormwater webpage at: http://www.pca.state.mn.us/sbiza7c.
For example, Table B-2 shows how the B[a]P equivalents were calculated for a hypothetical stormwater
pond where all 17 cPAHs were detected in the sediment sample. The contaminant concentrations are
entered into Column C. Each cPAH concentration is multiplied by the corresponding PEF value in Column
B to arrive at the individual B[a]P equivalent concentration in Column D. The individual B[a]P equivalent
concentrations are then summed to obtain the total B[a]P equivalents concentration listed at the
bottom of Column D.
Managing Stormwater Sediment BMP Guidance for Municipalities • June 2012 Minnesota Pollution Control Agency
B-2
Table B-2. Example – Calculating Total B[a]P Equivalents for Detected cPAH Data
* In this example benzo[b]fluoranthene and benzo[j]fluoranthene coeluted. In other words, the combined
concentration of both cPAHs was reported by the laboratory as 3.75 mg/kg benzo[b and j]fluoranthene. Since both
compounds have the same PEF value, 3.75 was entered for the sediment concentration of benzo[b]fluoranthene
while the concentration of benzo[j]fluoranthene was entered as zero.
A
cPAH Compound
B
PEF Potency
Equivalent
Factor
C
Sediment
Concentration
(mg/kg)
D
B[a]P
Equivalent
(mg/kg)
Benz[a]anthracene 0.1 2.190 0.219
Benzo[b]fluoranthene* 0.1 3.750 0.375
Benzo[j]fluoranthene* 0.1 0.000 0.000
Benzo[k]fluoranthene 0.1 1.320 0.132
Benzo[a]pyrene 1 2.270 2.270
Chrysene 0.01 2.790 0.028
Dibenz[a,h]acridine 0.1 0.219 0.022
Dibenz[a,h]anthracene 0.56 0.270 0.152
7H-Dibenzo[c,g]carbazole 1 0.160 0.160
Dibenzo[a,e]pyrene 1 0.828 0.828
Dibenzo[a,h]pyrene 10 0.419 4.190
Dibenzo[a,i]pyrene 10 0.391 3.910
Dibenzo[a,l]pyrene 10 0.150 1.500
7,12-Dimethylbenzanthracene 34 0.150 5.137
Indeno[1,2,3,-c,d]pyrene 0.1 1.350 0.135
3-Methylcholanthrene 3 0.170 0.512
5-Methylchrysene 1 0.160 0.160
Total B[a]P equivalents = 19.730
Managing Stormwater Sediment BMP Guidance for Municipalities • June 2012 Minnesota Pollution Control Agency
B-3
The MDH is in the process of reevaluating their recommendations for calculating total B[a]P equivalents.
Revised cPAH guidance is expected to be issued later this year. Additional information can be found on
the MDH website at: http://www.health.state.mn.us/divs/eh/risk/guidance/pahmemo.html.
New procedure for addressing nondetect data when calculating B[a]P equivalents:
It is unlikely that all 17 cPAHs will be detected in stormwater pond sediments (e.g., see Table A-2 in
Appendix A). Previously, the MPCA’s Stormwater Program recommended using one-half the
reporting limit for nondetect data. However, this substitution method introduces bias in the results
and can artificially inflate the B[a]P equivalent concentrations. The MPCA now recommends the
following procedures:
1. Calculate a screening total B[a]P equivalents concentrations with the detected and
estimated (J-flagged) cPAH data. If the total B[a]P equivalents exceed 3.0 mg/kg (the
current industrial SRV), then no further calculations are needed with the nondetect data.
2. If the screening total B[a]P equivalents are less than 3.0 mg/kg and the percentage of
nondetect data for each sample are ≤50%, then the nondetect data need to be included in
the calculation of total B[a]P equivalents. The MPCA recommends using Kaplan-Meier
statistics for calculating total B[a]P equivalents from the detected, estimated, and
nondetect data; this procedure works best when there are ≤50% nondetect data. Kaplan-
Meier is a nonparametric statistical method, and no assumptions about the distribution of
the data (whether they follow a normal or other distribution) need to be made (Helsel
2010, 2012). Kaplan-Meier has been shown to be superior to substitution methods for
nondetect data. Dennis Helsel, a retired statistician from the U.S. Geological Survey, has
developed user-friendly guidance on how to use Kaplan-Meier statistics. In particular, he
published a paper in 2010 on how to sum nondetect and detected data for calculating a
total value. His paper goes through a case study example showing how this can be done
using environmental chemistry data (i.e., polychlorinated biphenyls, dioxins, and furans)
and toxic equivalence factors to calculate toxic equivalence concentrations (this is
analogous to using the sediment cPAH data and the PEFs to calculate the total B[a]P
equivalents). His 2010 paper is freely available at:
http://onlinelibrary.wiley.com/doi/10.1002/ieam.31/full. Reading this paper and following
through with the examples will give people the training they need to do Kaplan-Meier
statistics. In addition, Dennis Helsel has developed a free Excel worksheet for using Kaplan-
Meier statistics at: http://practicalstats.com/nada/nada/downloads.html. He also offers
training classes/webinars and has a new book that clearly describes procedures for using
Kaplan-Meier statistics (Helsel 2012).
3. If the screening total B[a]P equivalents are less than 3.0 mg/kg and the percentage of
nondetect cPAH data are ≥50%, then there are increased difficulties with estimating the
portion of the total B[a]P equivalents from the nondetect data. In these cases, the MPCA
recommends reporting the total B[a]P equivalents based on the measured and estimated
data with a qualifier that states the percentage of nondetect cPAH data.
4. If all of the cPAH data are reported as not detected, then the B[a]P equivalents cannot be
calculated. In these cases, the municipality should investigate the QA/QC procedures of the
laboratory further to determine if they were adequate. Since PAHs are a ubiquitous class of
contaminants, a quality laboratory should be able to detect at least some of the cPAHs,
especially B[a]P, chrysene, and indeno[1,2,3-cd]pyrene.
Managing Stormwater Sediment BMP Guidance for Municipalities • June 2012 Minnesota Pollution Control Agency
B-4
Determining restrictions and proper management
The MPCA has developed human health-based SRVs for residential and industrial land use scenarios.
Analytical results for metals, noncarcinogenic PAHs, and total B[a]P equivalents (for cPAHs) are
compared to these SRVs to determine what restrictions are placed on the excavated sediment, including
management options for upland disposal.
An Excel file spreadsheet containing the Residential and Industrial SRVs are provided in the “Summary of
Stormwater Pond Sediment Results” Excel file under the “Permit and Program Forms” section of the
Stormwater webpage at: http://www.pca.state.mn.us/sbiza7c.
If all metal, total B[a]P equivalent (cPAHs), and noncarcinogenic PAH concentrations in the sediment are
below the corresponding Residential SRV values, this indicates exposure to the dredged sediment does
not present an unacceptable risk to humans in a residential scenario and management options may
include disposal of the excavated sediment in residential areas. If all metal, total B[a]P equivalent
(cPAHs), and noncarcinogenic PAH concentrations in the sediment are below the corresponding
Industrial SRV values, this indicates exposure to the dredged sediment does not present an
unacceptable risk to humans in an industrial setting and management options may include disposal of
the excavated sediment in industrial areas. If the metal, total B[a]P equivalent (cPAHs), or
noncarcinogenic PAH concentrations in the sediment exceed the industrial SRVs, this indicates that a
potential risk may exist from exposure to the sediments and appropriate management options are
required for the excavated sediment. In this case, contact the Stormwater Program for further guidance.
The SRVs are currently undergoing revision to ensure they incorporate the latest scientific toxicity data
available. In particular, the SRV for total B[a]P equivalents will be revised to incorporate new toxicity
data.
Soil Reference Values (SRVs):
SRVs are derived to assess potential human health exposures from soil using a reasonable maximum
exposure (RME) scenario. RME scenarios are intended to protect an entire population without being
overly conservative by using reasonable upper bound estimates for the most sensitive exposure
parameters and central tendency estimates for less sensitive exposure parameters.
SRVs are intended to evaluate both potential non-cancer and cancer risks associated with a
contaminant present in the soil. Two separate SRV values are calculated for each contaminant, one
for non-cancer risk and one for cancer risk. The final SRV value reported on the Residential or
Industrial SRV spreadsheet is the lower of the two. In other words, it is the smallest concentration of
the contaminant that could potentially pose either a non-cancer or cancer risk. For example, for
contaminant “X”, if the non-cancer SRV is 10 mg/kg and the cancer SRV is five mg/kg, then the final
SRV is reported as five mg/kg.
Managing Stormwater Sediment BMP Guidance for Municipalities • June 2012 Minnesota Pollution Control Agency
B-5
References
Cal/EPA (California Environmental Protection Agency). 1993. Benzo[a]pyrene as a toxic air contaminant.
Part B. Health effects of benzo[a]pyrene. Air Toxicology and Epidemiology Section, Office of
Environmental Health Hazard Assessment, Berkeley, CA.
Cal/EPA. 2009. Technical support document for cancer potency factors: Methodologies for derivation,
listing of available values, and adjustments to allow for early life stage exposures. Appendix B.
Chemical-specific summaries of the information used to derive unit risk and cancer potency values.
Office of Environmental Health Hazard Assessment, Oakland, CA.
(http://www.oehha.ca.gov/air/hot_spots/2009/AppendixB.pdf)
Helsel, D.R. 2010. Summing nondetects: Incorporating low-level contaminants in risk assessment.
Integr. Environ. Assess. Manage. 6:361-366. (article is freely available at:
http://onlinelibrary.wiley.com/doi/10.1002/ieam.31/full)
Helsel, D.R. 2012. Statistics for Censored Environmental Data Using Minitab® and R. Second Edition.
John Wiley & Sons, Inc.: Hoboken, NJ. (http://www.wiley.com/WileyCDA/WileyTitle/productCd-
EHEP002278.html)
MDH (Minnesota Department of Health). 2001. Polycyclic aromatic hydrocarbons: Methods for
estimating health risks from carcinogenic PAHs. Minnesota Department of Health, St. Paul, MN.
(http://www.health.state.mn.us/divs/eh/risk/guidance/pahmemo.html)
APPENDIX B
OUTFALL INSPECTION FACT SHEET
Federal regulations define an outfall as “the point source where a municipal separate storm sewer system
discharges to a receiving water, or the stormwater discharge permanently leaves the permittee’s MS4. It
does not include diffuse runoff or conveyances that connect segments of the same stream or water
systems…”
Oufall BMP Inspection Condition:
Clear/Functioning
Needs Maintenance/Cleaning
Needs Repair
Needs Replacement
Immediate Action Needed
Pond
What is an Outfall?
Key
Notes
Definitions
“C
i
t
y
A
”
l
i
m
i
t
s
“C
i
t
y
B
”
l
i
m
i
t
s
Wetland
Wetland
Pond
River
- City A’s Outfall
- City B’s Outfall
- City A’s Stormwater
Conveyance
- City B’s Stormwater
Conveyance
Wetland to wetland = outfall
Pond to wetland = outfall
Pond to pond = no outfall
Conveyance to pond = no outfall
Conveyance to river = outfall
Natural channel to river = no outfall
Stream to wetland = no outfall
City A into City B = outfall (owned by City A)
City B into City A = outfall (owned by City B)
Conveyance/MS4: Includes roads with
drainage systems, municipal streets,
catch basins, curbs, gutters, ditches,
man-made channels, or storm drains.
Outfall: The point source where a
conveyance/MS4 discharges to a receiv-
ing water, or the stormwater discharge
permanently leaves the permittee’s MS4.
Receiving Water: Means any lake, river,
stream, or wetland that receives storm-
water discharges from an MS4.
Outlet: The location at which the water
leaves the basin.
Inlet: The location at which the water
enters the basin.
Natural Channel
Stream
Outfall Inspection Form
SOP MCM 6 - Outfall Inspection Form
Date & Time of Inspection
Weather Conditions
24hr Precipitation inches
Reason for Inspection
Inspector
BMP I.D. # Receiving Water: BMP Condition (5-Star) *1
Address / Location: Illicit Discharge Present: Yes No (if yes, complete IDDE form)
IDDE Comments:
Inspector Comments:
Outfall Condition Checklist
Erosion *2 Physical Damage to Pipe *2
Debris in Outfall *3 Vegetative Setting to Outfall *4
Comments:
Discharge Checklist
Visible Flow in Structure Yes No
Outfall Discharge
(check all that apply):
Clear
Oil Sheer
Colored Water
Odor
Murky / Turbid
Floating Objects
Scum
Suds
Water Height from Invert *5
Sediment Buildup *5
Comments:
Photo #1:
Photo #2:
*1 a. Clear/Functioning
b. Needs Maintenance/Cleaning
c. Needs Repair
d. Needs Replacement
e. Immediate Action Needed
*2 a. None
b. Minor
c. Severe
*3 a. Clear
b. Partially Obstructed
c. Mostly Blocked
*4 a. No Vegetation
b. Grass
c. Reeds
d. Shrubs
e. Trees
*5 a. 0%
b. 25%
c. 50%
d. 75%
e. 100%
Standard Operating Procedure
Appendix C - Spill Response Plan
EMERGENCY CONTACT INFORMATION
Onsite Emergency Contact(s) Steve Scherer – Primary
(763) 473-8842
Lisa DeMars –Secondary
(763) 473-8852
Emergency Response Contact(s) Fire/Paramedics/Police: 911
PoliceNon-Emergency Line: (763) 473-9209
MN Department of Health: (651) 201-5414
National Response Center: (800) 424-
8802 [Other] [Business phone]
Step 1: Approach the Scene
SPILL RESPONSE PLAN
• Use safety first in responding to spills. Do not endanger yourself or others by entering a
hazardous environment. If there is a fire or medical attention is needed, call 911 immediately.
• Avoid exposure. Approach the spill from upwind and stay clear of spills, vapors, fumes and
smoke.
Step 2: Secure the Scene
• Isolate the spill.
• Keep people away from the scene; divert traffic and pedestrians as needed.
• If possible, stop the source of the spill.
• Eliminate any ignition sources.
Step 3: Identify the Hazards
• Attempt to identify the spilled material.
o Characteristics (odor, color, sheen), labels/markings, container type, activities in the area,
hazard warnings, etc.
Step 4: Assess the Situation
• Determine the appropriate first response actions and if additional response help is needed
• The response will be dictated by the size of the spill and the hazard:
o Is there a fire, a spill, or a leak?
o Is there a potential for it to mix with something else?
• Observe your surroundings:
o Who/what is at risk?
o Is an evacuation necessary?
o What resources are required and readily available to contain the spill?
Standard Operating Procedure
Step 5: Report the Spill
• Report spills that may cause pollution, such as toxic, flammable, corrosive and dangerous
industrial chemical spills.
o Minnesota has a reporting threshold of greater than five-gallons for petroleum spills.
Spills of any quantity of all other chemicals or materials should be reported. When in
doubt, report.
• Contact the Minnesota Department of Public Safety Duty Officer at 1-800-422-0798 (toll free) or
651-649-5451 (Metro area), if the spill of any substance or material may cause or has caused
pollution of waters of the state.
Step 6: Contain the Spill
• Always wear the appropriate personal protective equipment, such as gloves, boots, and safety
glasses. Know the limitations of the personal protective equipment.
• Place booms or available materials around the perimeter of the spill to keep it from spreading.
o If the spill is a threat to any storm water conveyance, like street gutter, storm drain or
inlet, swale, ditch, storm, or river, place absorbent between the spill and storm device.
• Apply absorbent materials starting from the downhill and outside edge of the spill.
Step 7: Clean Up the Spill
• If you have the proper training, small spills may be cleaned up according to the chemical label
and your training.
o Do not wash or hose down the spill into the street, ditch or storm drain.
o If flammable liquid is spilled, ventilate the area and eliminate any possible sources of
ignition.
o Clean up the spills, leaks and drips quickly. Use “dry” clean-up methods, such as
sweeping or shoveling. If the spill can be moved by wind, cover the material with
sheeting to prevent spreading.
o Place all clean-up waste in appropriate containers. If hazardous, insure that material is
placed in a hazardous waste container.
o Dispose of spill material in compliance with all Federal, State and Local regulations.
• If you do not have proper training, or the spill is a large spill, leave the area and notify
Emergency Responders (911). Give the operator the spill location, chemical spilled and
approximate amount.
Step 8: Complete Spill Documentation and Follow-up
• Clean and decontaminate all reusable spill cleanup equipment.
• Be sure to restock your spill response materials and personal protection equipment as soon as
possible.
• Update facility spill records.
Appendix D - Stormwater Pond Inspection Form
Date & Time of Inspection
IDDE LP or HP Area
24hr Precipitation inches
Reason for Inspection
Inspector
BMP I.D. # Receiving Water: BMP Condition (5-Star) *1
Address / Location: Illicit Discharge Present: Yes No (if yes, complete IDDE form)
IDDE Comments:
Inspector Comments:
Pond Checklist
Erosion *2 Width of Vegetate Buffer *3
Sediment (sediment, gravel, etc.) *2 Pond Vegetation *4
Description of Flow in Pond *5
Comments:
Outflow Structure Checklist
Visible Flow in Structure Yes No Water Height from Invert *4
Erosion *2 Physical Damage to Pipe *2
Debris in Pipe *6 Sediment Buildup near Pipe *4
Comments:
Outfall / Inflow Structure Checklist
* Complete Separate Outfall / Inflow Structure Inspection Form *
Photo #1:
Photo #2:
*1 a. Clear/Functioning
b. Needs Maintenance/Cleaning
c. Needs Repair
d. Needs Replacement
e. Immediate Action Needed
*2 a. None
b. Minor
c. Severe
*3 a. Less than 5’
b. 5’ – 29’
c. 30’ – 50’
d. Greater than 50’
*4 a. 0%
b. 25%
c. 50%
d. 75%
e. 100%
*5 a. None
b. Trickle
c. Moderate
d. Substantial
*6 a. Clear
b. Partially Obstructed
c. Mostly Blocked
ID Structure Name Campus Address POC Present?
Appendix D - Medina Facility Inventory
Ordinance
Animal Waste
1. Definitions. The following words, terms and phrases, when used in this section, shall have
the meanings ascribed to them in this subsection, except where the context clearly indicates
a different meaning:
a. Animal. A dog, cat or other animal kept for amusement or companionship.
b. Owner/Custodian. Any person who harbors, feeds, boards, possesses, keeps or has
custody of an animal.
c. Immediately. At once, without delay.
d. Soil/defile. To make unclean from excrement.
e. Waste. Solid matter expelled from the bowels of the pet; excrement.
2. Public Property. No owner or custodian of any animal shall fail to remove said animal’s
waste from any public property or street, sidewalk, or public right-of-way. Pet waste must be
deposited in a sanitary manner.
3. Removal. It is unlawful for any person owning, keeping or harboring an animal to permit said
animal to be on any public property without having in his/her immediate possession a device
for the removal of pet waste.
4. Disposal. It is unlawful for any person owning, keeping or harboring an animal to fail to
remove said animal’s waste without proper disposal. Proper disposal of animal waste
includes: 1) bagging for disposal in the owner or keeper's waste receptacle or2) bagging for
disposal in a waste receptacle in a public park or park area.
5. Disposal in the MS4. Disposal of animal waste in the municipal separate storm sewer system
(MS4) is prohibited.
6. Disposal in Public Compost. Disposal of animal waste in public compost is prohibited.
7. Exemptions. The provisions of this section shall not apply to the ownership or use of any
properly identified service animals, animals when used for police activities, or tracking
animals when used by or with the permission of the appropriate authorities.
[(i) Any person violating any provision of this ordinance may be subject to a forfeiture of not less than
$200 nor more than $500.
Ordinance
Salt Storage at Commercial, Industrial, and Institutional Facilities
1. Covered or Indoor operations for the storage of deicing materials must be provided whenever
possible in order to prevent such material from being affected by rain, snow, or melt water.
2. All salt and other deicing materials stored outdoors must be covered at all times. When not
using a permanent roof, a waterproof impermeable, flexible cover must be placed over all
storage piles. The cover must prevent runoff and leachate from being generated by the
outdoor storage piles. The cover must be secured to prevent removal by wind or other storm
events. Piles must be formed in a conical shape and covered as necessary to prevent leaching.
3. Facility siting.
a. The facility must be in close proximity to the area in which the deicing materials are to be
used, if practical.
b. Each facility must be located outside of floodplains and 200 feet from lakes, rivers,
streams, ditches, storm drains, manholes, catch basins, wetlands, and any other areas
likely to absorb runoff. A facility must not be located in close proximity to surface water
features, water supplies, wells or drywells.
c. A facility must be located on impermeable surfaces.
d. The property’s slope must be away from the facility’s salt, deicer, and sand storage area.
e. Salt vulnerable natural areas should be avoided as storage facilities to the extent possible.
Where they cannot be avoided, specific measures should be instituted to protect
vulnerable areas. Salt vulnerable areas include, but are not limited to:
(i) Areas with salt sensitive vegetation
(ii.) Areas serving as a source of drinking water (surface water and groundwater)
(iii.) Areas with bodies of water with low dilution, low volume, or salt sensitive
species
(iv.) Areas associated with groundwater recharge zones or shallow water table, with
medium to high permeable soils.
4. Snow Piles. Snow piles must be located downslope from salt and deicer storage areas to
prevent the snow melt from flowing through storage areas and carrying material to the
nearest drainage system or waterway.
5. Transfer of materials. Practices must be implemented in order to reduce exposure (e.g.,
sweeping, diversions, and/or containment) when transferring salt or other deicing
material.