Study exam for the Soil Erosion and Sedimentation Control Training - Unit 4
Restriction
Method
Substitute
Motivation
Silt fencing, straw bales
Vegetative, structural
Elevation contours, trenching
Grading, nonwoven geotextile fabric
Length, steepness, 20-25
Roughness, length, 50-55
Smoothness, steepness, 10-15
Stone
Grass
Brush
Soil
Vegetative
Structural
Erosion
Trenches, stone mats
Crushed stone, geotextile fabric
Silt fences, straw bales
Silt fences
Trenches
Elevation contours
Crushed stones
12, steepness
6, elevation contour
9, height
3, elevation
Very little water will pass through them
Animals eat them
Deteriorate rapidly
Very time consuming to trench them in
Not cost effective
Crushed rock or stone, 50
Crushed glass, 40
Stone matting, 30
Straw
Nonwoven geotextile fabric
Sod
Silt fencing
2
4
3
6
Type of soil in the drainage area
Time the water remains in the basin
Velocity of the water flow
Size and density of sediment particles
Placing a gravel filter in front of or around the drain inlet
Anticipated storm event
Velocity of the water flow
Size of the drainage area
Time that the water remains in the basin
Type of soil in the drainage area
Vertical riser
Perforated
Dissipating
Outlet
Filtered
Perforated
Lined
Protected
Dissipaters
Minimumizer
Filter
Damper
Risers
Grates
Inlets
Pipes
Covering with straw bales
Placing a gravel filter in front of or around the drain inlet
Sealing with an impervious material
Installing silt fence around the perimeter of the drain inlet
Wrapping the grate with geotextile materials