A silt fence is a temporary sediment barrier made of woven
synthetic filtration fabric supported by steel or wood posts.
A silt fence should be installed below disturbed areas where
erosion would occur in the form of sheet and rill erosion.
It helps to contain sediment within the construction site.
The bottom four inches of fabric must be buried beneath
the soil surface to prevent sediment from going under the
fence.
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The two silt fences prevent sediment
from going into the tree save area, which is further protected
by a chain link fence. |
A super silt fence has metal poles, spaced 10 feet apart,
supporting a chain link fence. The woven synthetic filtration
fabric is stretched across its length. A super silt fence
is sturdier and less likely to be breached than a regular
silt fence. |
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The
super silt fence prevents erosion of the slope from affecting
the stream below. |
No formal design is required, but
several criteria must be considered to protect desirable
trees from mechanical and other injury during land disturbing
and construction activities. At a minimum, the limits of
clearing shall be located outside the drip line of any tree
to be retained and no closer than 5 feet to the trunk of
any tree. Each tree to be saved must be marked at a height
visible to equipment operators. |
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This
is an unusual tree save area in that the trees were dug
up and relocated by the builder for later replanting throughout
the development. |
When storm drain inlets are to be
made operational before the site is stabilized, they must
be protected to prevent sediment from entering the storm
drain system. Depending on the type of inlet, protection
devices may include sod, concrete blocks, stone, wire mesh,
filter fabric and/or silt fencing. |
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A sediment basin is a temporary impoundment (reservoir)
built to retain sediment and debris with a controlled stormwater
release structure. A sediment basin controls drainage areas
over three acres with a maximum allowable drainage area
of 100 acres. |
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This
nicely grassed sediment basin prevents eroded earth materials
from leaving the construction site. A sediment basin differs
from a sediment trap in that it serves a larger drainage
area (three or more acres up to 100 acres.) |
A temporary impoundment (reservoir)
built to retain sediment and debris on a drainage area less
than three acres. The sediment trap, on areas between one
and three acres, is formed by building a predetermined reservoir
confined by an earthen embankment with a pipe outlet. For
areas less than one acre, a stone outlet is sufficient.
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Dust control is necessary in areas
subject to surface and air movement of dust from exposed
soil. Irrigation with a water truck is a common dust control
practice.
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The
truck is spraying water from the back. |
Whenever traffic will be leaving
a construction site and moving directly onto a public road
or other paved area, there must be a stone construction
entrance lined with filter fabric to reduce the amount of
mud being transported off-site. If conditions on the site
are such that most of the mud is not being removed from
the vehicles by driving over the stone, then the tires must
be washed, and the waste water carried away to a settling
area. |
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Vehicles
stop at the wash rack to have the tires hosed off. The muddy
water drains through the grates to the settling area. |
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A diversion dike is a channel with
a supporting earthen embankment on the lower side constructed
across or at the bottom of a slope to intercept surface
water runoff. Usually, the runoff is diverted into a sediment
trap or sediment basin.
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The
nicely grassed berm keeps the runoff in the channel on site. |
Made of tubing or a another conduit
of nonerosive material, a slope drain extends from the top
to the bottom of a slope with an energy dissipater at the
outlet end. A slope drain prevents off-site and/or onsite
runoff from eroding a steep slope by containing the runoff
as it goes down the slope. |
No
photo available yet. |
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