Soil Erosion and Sedimentation Control
Welcome to the Soil Erosion and Sedimentation Control homepage.
The purpose of our program is to protect the waters for the benefit of the
people and wildlife of Michigan within Washtenaw County.
Our office regulates earth moving activities everywhere in
Washtenaw County except the City of Ann Arbor, City of Chelsea, Bridgewater
Township, Dexter Township, Freedom Township, Lima Township, Lyndon Township,
Manchester Township, Pittsfield Township, Sharon Township, Sylvan Township,
Ypsilanti Township, and the Village of Manchester.
Our homepage includes the following information:
Why is Sedimentation Control
Important?
Safety Reasons
- Eroded soils can enter water bodies and channels, raising water levels
and blocking culverts. This can increase the chances for inundation of
surrounding land.
- Sediment (soil that has been eroded) can get deposited onto streets and
roads by vehicles leaving the site or by stormwater runoff. When wet, these
sediments can be dangerous for drivers and bicycle riders.
Environmental Reasons
- Sediment in water bodies can cover the eggs of fish and other
organisms, preventing them from reproducing.
- Excess sediment that is suspended in streams and rivers acts like
sandpaper on fish and other organisms. Suspended sediment can also abrade
the tissues of plants that live in the water.
- Sediment in water bodies can clog the gills of fish and other organisms
that have gills, making breathing difficult.
- Sediment reduces light penetration, making photosynthesis more
difficult for water plants.
- While blocking light penetration, the soil particles absorb the heat
from sunlight and later release it, thereby raising the temperature of the
water and driving off desirable fish populations.
Aesthetic & Recreational Reasons
- Clear water is more desirable for swimming, boating, canoeing and
fishing than mud-filled water.
- Excess sediments build up in lakes and rivers. This raises the water
level but reduces water depth, which decreases canoeing and fishing
opportunities.
Economic Reasons
- Excess sediment can increase the cost of treating drinking water and
negatively affect the equipment used in the drinking water treatment
process. This increases the cost of treating drinking water.
- Other pollutants such as pesticides, herbicides and oil, can become
attached to eroded soils and enter water bodies along with the soil. These
contaminants can making swimming unhealthy for children and adults.
Grading Requirements
- A project/property identifier must be posted and visible from the road
at time of application in order to conduct a preliminary inspection which
is required before a permit may be issued.
- A copy of the permit and approved plans must be kept at the work site
and visible from the road, and available at time of inspection.
- No earth moving activity can begin without a grading permit.
- Silt fencing, if required, must be trenched in a minimum of 6 inches
and backfilled. The fencing may be toed-in with pea gravel if installed in
winter.
- Stone access drives must be installed prior to construction with a
minimum of 50 feet in length.
- Stockpiling of any excavated material must be kept away from sensitive
areas and adequate controls must be in place.
- Catch basins, if installed, must be protected with silt sacks or
Catch-All type protection.
- Dewatering operations must have some type of control, e.g. filter bag,
vegetative filter area. There shall be no dewatering of unfiltered
water.
- Erosion control blankets are required on slopes of 4:1 or steeper.
- Rock check dams are to be used instead of straw bales or silt fencing
in concentrated flow locations such as ditches.
- Immediately after installation of stormwater outlets, rip rap must be
installed.
- All areas of a project that are disturbed must be temporarily or
permanently stabilized by December 1.
- All earth changes shall be designed, constructed and completed in such
a manner which limits the exposed area of any disturbed land for the
shortest possible period of time.
Grading Standards
- Detention/retention/sedimentation ponds must be constructed and
stabilized prior to other earth moving activities to collect sediment
caused by erosion. This shall be designed and constructed to reduce the
water flow to a non-erosive velocity (see Washtenaw
County Drain Commissioner's Specifications).
- After all temporary erosion control measures have been installed, the
owner/contractor shall call this office for an installation
inspection.
- Permanent erosion control measures shall be completed within 15
calendar days after final grading or earth moving activity has been
completed. A final inspection shall be scheduled by the
owner/contractor.
- All soil, miscellaneous debris or other materials spilled, dumped, or
otherwise deposited on streets, highways, sidewalks or other thoroughfares
during transit to or from the earth change site shall be removed
promptly.
Plan Review Requirements for
Minor Projects
(All information must be provided by the
applicant.)
- Name, address and telephone number of owner.
- Vicinity map, clearly indicating the exact location of
the property.
- A site map showing the extent of the proposed project, all adjacent
properties and proximity to all surface waters within 500 feet of the
property's perimeter.
- Location of structures and vegetation on the site and extending just
beyond the property's perimeter.
- Existing and proposed topography (including cut and fill).
- Description and location of existing and proposed on-site drainage,
including surface runoff and drainage ditches.
- Delineation of disturbed areas of the project (with all features and
sizes indicated).
- Location and duration of stockpile for excavated material.
- If dewatering, location and control measures used.
- Location, types, and cross-sectional views of temporary and permanent
erosion and sedimentation control measures.
- Name and phone number of party responsible for on-going maintenance of
all permanent erosion control measures.
Plan Review Requirements for
Major Projects
(All information must be provided by the
applicant.)
- Names, addresses and telephone numbers of the owner, developer and
petitioner.
- Legal description and vicinity map, clearly indicating the
exact location of the property.
- A site map showing the extent of the proposed project, all adjacent
properties and proximity to all surface waters within 500 feet of the
property's perimeter.
- A site plan at a scale of not more than 1 inch equals 100 feet which
includes:
-
- Location of structures and vegetation on the site and extending 50
feet beyond the property's perimeter.
- Location of soil types and associated written description.
- Existing and proposed topography at a minimum of two (2) foot contour
intervals extending 50 feet beyond the property's perimeter.
- Description and location of existing and proposed on-site drainage,
including surface runoff, drainage ditches, and detailed storm sewer
plans.
- Delineation of disturbed areas of the project (with all features and
sizes indicated).
- Location and duration of stockpile for excavated material.
- If dewatering, location and control measures used.
- Location, types and cross-sectional views of temporary and permanent
erosion and sedimentation control measures.
- Name and phone number of party responsible for on-going maintenance
of all permanent erosion control measures.
Program Staff
Lee, Katie, Soil Erosion Control Officer, 734-222-3978,
leek@ewashtenaw.org
This is printed from: http://www.ewashtenaw.org/government/departments/soil_erosion/index_html
on May 13, 2008 12:31 pm