Erosion and Sediment Control Correct Questions and Answers!!

Erosion and Sediment Control Correct

Questions and Answers!!

Minimum Standard 1 - ANSWER 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 - ANSWER - stabilize in 14 days

- temporarily seed

- mulch

- permanently stabilize if dormant > 1 year

Site at Final Grade - ANSWER - stabilize in 7 days (recommended immediately)

- permanently or temporarily seed and mulch

- mulch/matting/straw

Minimum Standard 2 - ANSWER 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 - ANSWER 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 - ANSWER 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 - ANSWER 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 - ANSWER 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 - ANSWER 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 - ANSWER 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 - ANSWER 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 - ANSWER 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 - ANSWER 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 - ANSWER 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 - ANSWER 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 - ANSWER 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