Erosion and Sediment Control Exam |77 Questions and
Answers
Minimum Standard 1 - -Stabilization
permanent or temporary soil stabilization shall be applied to denuded areas within seven
days after final grade is reached on any portion of the site; temporary soil stabilization
shall be applied within seven days to denuded areas that may not be at final grade but will
remain dormant for longer than 14 days; permanent stabilization shall be applied to areas
that are to be left dormant for more than one year
-Site NOT at Final Grade - -- stabilize in 14 days
- temporarily seed
- mulch
- permanently stabilize if dormant > 1 year
-Site at Final Grade - -- stabilize in 7 days (recommended immediately)
- permanently or temporarily seed and mulch
- mulch/matting/straw
-Minimum Standard 2 - -Stock Piles, Waste and Borrow Areas
during construction, soil stock piles and borrow areas shall be stabilized or protected with
sediment trapping measures
mulch prevents erosion by protecting the surface from raindrop impact and silt fence
intercepts and detains from disturbed areas
-Minimum Standard 3 - -Permanent Vegetation
permanent vegetation cover shall be established on denuded areas not otherwise
permanently stabilized (permanent vegetation shall not be considered established until a
ground cover is achieved that is uniform, mature enough to survive, and will inhibit erosion
*there is no % associated with this*)
reduce erosion and decrease sediment yield from disturbed area
this is the standard used to verify that a site is ready for release of bonds or surety
-Minimum Standard 4 - -First-Step Measures
Sediment basins and traps, perimeter dikes, sediment barriers and other measures
intended to trap sediment shall be constructed as a first step in any land-disturbing activity
and shall be made functional before upslope land disturbance takes place
,a certain amount of initial land disturbance may be required to provide access for
equipment to install the perimeter controls, but site clearing and grading should be kept to
a minimum until the perimeter controls are in place
intercepts and detains small amounts of sediment from disturbed areas during
construction operation to prevent sediment from leaving the site and decrease velocity of
sheet flows and low-to-moderate level channel flow
-Perimeter Controls - -assures that sediment does not leave the perimeter of the land-
disturbing area once site clearing, grading, and construction commences
Examples: silt fences, sediment traps, sediment basins, construction entrance, temporary
diversions, diversions
-Minimum Standard 5 - -Earthen Structure Stabilization
stabilization measures shall be applied to earthen structures such as dams, dikes, and
diversions immediately after installation
reduce erosion and sedimentation and reduce damage from sediment and runoff to
downstream or off-site areas
-Minimum Standard 6 - -Traps and Basins
sediment traps and basins shall be designed and constructed based upon the total drainage
area (not just disturbed area) to be served by the trap or basin
-Sediment Traps - -minimum storage capacity shall be 134 cubic yards per acre of
drainage area and shall only control drainage areas less than 3 acres
*stone outlet = trap*
-Sediment Basins - -surface runoff from disturbed areas that is comprised of flow from
drainage areas greater than or equal to 3 acres shall be controlled by a basin; minimum
storage capacity of a sediment basin shall be 134 cubic yards per acre of drainage area; the
outfall system shall, at a minimum, maintain the structural integrity of the basin during a
25-year storm of 24-hour duration; runoff coefficients used in runoff calculations shall
correspond to a bare earth condition or those conditions expected to exist while the
sediment basin is utilized.
-Sediment Trapping Devises - -1. place near the lowest drainage points of a project
2. install as a first-step measure [MS-4]
3. stabilize immediately [MS-5]
, 4. must include outlet protection for basins [MS-11]
-Minimum Standard 7 - -Cut and Fill Slopes
roughening the surface of the slope decreases runoff, lowers the velocity runoff, increases
water retention, and leads to better seed germination
slopes that are found to be eroding excessively within on year of permanent stabilization
shall be provided with additional slop stabilizing measures until the problem is corrected
-Minimum Standard 8 - -Concentrated Runoff
shall not flow down cut or fill slopes unless contained within an adequate temporary or
permanent channel, flume or slope drain structure
outlets of these drains need outlet protection to prevent erosion from the concentrated
flow
size of pipe depends on drainage area
temporarily conduct concentrated stormwater runoff safely down the face of a cut or fill
slope without causing erosion on or below the slope
-Minimum Standard 9 - -Water Seeps
whenever water seeps from a slope face, adequate drainage or other protection shall be
provided
cut and fill operations may expose shallow aquifers or groundwater tables from which
water may seep through the side of a slope
-Minimum Standard 10 - -Inlet Protection
all storm sewer inlets that are made operable during construction shall be protected so
that sediment-laden water cannot enter the conveyance system without first being filtered
or otherwise treated to remove sediment
storm sewers are designed to efficiently transport stormwater away from the site, so when
sediment enters the storm sewer system, two negative effects can occur:
1. when velocity of flow is high, much of the sediment will be quickly transported to the
nearest receiving channel
2. when velocity of the flow is low, the sediment may be deposited in the pipes resulting in
clogging and potential flooding of a site during storm events
prevents sediment from entering storm drainage systems prior to permanent stabilization
of the disturbed area
Answers
Minimum Standard 1 - -Stabilization
permanent or temporary soil stabilization shall be applied to denuded areas within seven
days after final grade is reached on any portion of the site; temporary soil stabilization
shall be applied within seven days to denuded areas that may not be at final grade but will
remain dormant for longer than 14 days; permanent stabilization shall be applied to areas
that are to be left dormant for more than one year
-Site NOT at Final Grade - -- stabilize in 14 days
- temporarily seed
- mulch
- permanently stabilize if dormant > 1 year
-Site at Final Grade - -- stabilize in 7 days (recommended immediately)
- permanently or temporarily seed and mulch
- mulch/matting/straw
-Minimum Standard 2 - -Stock Piles, Waste and Borrow Areas
during construction, soil stock piles and borrow areas shall be stabilized or protected with
sediment trapping measures
mulch prevents erosion by protecting the surface from raindrop impact and silt fence
intercepts and detains from disturbed areas
-Minimum Standard 3 - -Permanent Vegetation
permanent vegetation cover shall be established on denuded areas not otherwise
permanently stabilized (permanent vegetation shall not be considered established until a
ground cover is achieved that is uniform, mature enough to survive, and will inhibit erosion
*there is no % associated with this*)
reduce erosion and decrease sediment yield from disturbed area
this is the standard used to verify that a site is ready for release of bonds or surety
-Minimum Standard 4 - -First-Step Measures
Sediment basins and traps, perimeter dikes, sediment barriers and other measures
intended to trap sediment shall be constructed as a first step in any land-disturbing activity
and shall be made functional before upslope land disturbance takes place
,a certain amount of initial land disturbance may be required to provide access for
equipment to install the perimeter controls, but site clearing and grading should be kept to
a minimum until the perimeter controls are in place
intercepts and detains small amounts of sediment from disturbed areas during
construction operation to prevent sediment from leaving the site and decrease velocity of
sheet flows and low-to-moderate level channel flow
-Perimeter Controls - -assures that sediment does not leave the perimeter of the land-
disturbing area once site clearing, grading, and construction commences
Examples: silt fences, sediment traps, sediment basins, construction entrance, temporary
diversions, diversions
-Minimum Standard 5 - -Earthen Structure Stabilization
stabilization measures shall be applied to earthen structures such as dams, dikes, and
diversions immediately after installation
reduce erosion and sedimentation and reduce damage from sediment and runoff to
downstream or off-site areas
-Minimum Standard 6 - -Traps and Basins
sediment traps and basins shall be designed and constructed based upon the total drainage
area (not just disturbed area) to be served by the trap or basin
-Sediment Traps - -minimum storage capacity shall be 134 cubic yards per acre of
drainage area and shall only control drainage areas less than 3 acres
*stone outlet = trap*
-Sediment Basins - -surface runoff from disturbed areas that is comprised of flow from
drainage areas greater than or equal to 3 acres shall be controlled by a basin; minimum
storage capacity of a sediment basin shall be 134 cubic yards per acre of drainage area; the
outfall system shall, at a minimum, maintain the structural integrity of the basin during a
25-year storm of 24-hour duration; runoff coefficients used in runoff calculations shall
correspond to a bare earth condition or those conditions expected to exist while the
sediment basin is utilized.
-Sediment Trapping Devises - -1. place near the lowest drainage points of a project
2. install as a first-step measure [MS-4]
3. stabilize immediately [MS-5]
, 4. must include outlet protection for basins [MS-11]
-Minimum Standard 7 - -Cut and Fill Slopes
roughening the surface of the slope decreases runoff, lowers the velocity runoff, increases
water retention, and leads to better seed germination
slopes that are found to be eroding excessively within on year of permanent stabilization
shall be provided with additional slop stabilizing measures until the problem is corrected
-Minimum Standard 8 - -Concentrated Runoff
shall not flow down cut or fill slopes unless contained within an adequate temporary or
permanent channel, flume or slope drain structure
outlets of these drains need outlet protection to prevent erosion from the concentrated
flow
size of pipe depends on drainage area
temporarily conduct concentrated stormwater runoff safely down the face of a cut or fill
slope without causing erosion on or below the slope
-Minimum Standard 9 - -Water Seeps
whenever water seeps from a slope face, adequate drainage or other protection shall be
provided
cut and fill operations may expose shallow aquifers or groundwater tables from which
water may seep through the side of a slope
-Minimum Standard 10 - -Inlet Protection
all storm sewer inlets that are made operable during construction shall be protected so
that sediment-laden water cannot enter the conveyance system without first being filtered
or otherwise treated to remove sediment
storm sewers are designed to efficiently transport stormwater away from the site, so when
sediment enters the storm sewer system, two negative effects can occur:
1. when velocity of flow is high, much of the sediment will be quickly transported to the
nearest receiving channel
2. when velocity of the flow is low, the sediment may be deposited in the pipes resulting in
clogging and potential flooding of a site during storm events
prevents sediment from entering storm drainage systems prior to permanent stabilization
of the disturbed area
