Stormwater Erosion and Sedimentation Control exam questions fully solved & updated 2024

Erosion Process by which the land surface is worn away by the action of wind, water, and gravity Sedimentation Settling out of soil particles transported by wind and water. Water Erosion Classifications Overland and Stream/Channel Four Processes of Overland Erosion Splash/Drop, Sheet, Rill, Gully 3 Physical Effects of Erosion and Sedimentation Increased Flooding Reduced hydraulic capacities in Rivers, Streams, Channels, Reservoirs Increased maintenance of stormwater systems Increased water treatment costs Decreased recreational value 3 Biological Effects of Erosion and Sedimentation Reduced light for aquatic plants Clogs fish gills Impairs spawning Disrupts food chain Blankets bottom Suppresses aquatic life Disrupts ecosystem Planning the development to fit the terrain using the particular - Topography Soil Drainage patterns Natural vegetation of the site Minimize the extent of the area exposed at one time and duration of exposure Perimeter Controls Protect the disturbed area from off-site runoff Protect off-site areas from sediment damage Erosion Conteol Prevent on-site damages Keep ____ low and ____ runoff from site Low Retain Stabilized Disturbed Areas ____ after final grading to prevent _____ from causing erosion Immediately Raindrop Impacts Implement a thorough _____ and _____ (inspection) program as required in the Construction Generic Permit (CGP) Maintenance Follow up Clay and Much Soil particles smaller than .002mm Cause most erosion and turbidity problems in Florida and World Soils in Type A Hydrologic Group Low infiltration rates High runoff potential when thoroughly wetted Rainfall Index Only factor in the Universal Soil Loss Equation which is beyond the developers control Slope ___, ____ and ____ are the factors that are most easily manipulated by the developer Length, Gradient and Cover Factor RUSLE Equation used to predict soil loss Stabilized disturbed lands immediately to save ____ Money Who can you contact for soil survey info? NRCS 5 Soil Forming Factors Climate Topography Organisms Parent material Time T/F Waste disposal is a problem for the individual workers and some contractors but it's no big deal False T/F Truck washing should be done in a designated area, not near the perimeter controls True T/F Storage of paints, solvents, cement, pesticides, acids, or other potentially polluting chemicals is no big deal because they are only temporarily stored and get used up quickly. False Temporary Gravel Construction Entrance Specifications 50 ft long 6 inched thick 2 inch stone or FDOT #1 Prior to Installing Gravel Entrance A geotextile should be placed on the ground to simplify installation and maintenance Maintenance on Gravel Entrance When void spaces are full of sediment Maximum drainage area for silt fence under sheet flow conditions 1/4 acre per 100ft of barrier length Average Usable Life of Silt Fence 6 months Proper Installation of Silt Fence Specifications 4 inches deep 4 inches wide 8 inches of fabric to extend into the trench Silt Fence Stakes Specifications 2inchx4inchx3feet long 2inchx4inch frame will be constructed around the top Purpose of Sediment Trap Filter/Detain turbid water Drainage Area for Temporary Sediment Trap Maximum 5 acres Initial storage capacity 134 cubic yards per acre Max life is 18 months When constructing a pipe outlet sediment trap, the top of the riser pipe must be at least _____ feet below the top of the embankment 1.5 When constructing a storm inlet sediment trap, the trap shall be between _____ ft deep measured from the _____ point of the outlet 1-2 Low Purpose of a sediment basin Filter/detain turbid runoff from disturbed areas T/F In a sediment basin, baffles are used to increase flow length. True Maximum allowable drainage area for a temporary slope drain 5 acres T/F A diversion or earthen dike shall be used to direct stormwater into the temporary slope drain True The height of the dike at the inlet shall be equal to the ______ plus ___ inches Pipe diameter 6 Maximum spacing between check dams should be such that the _____ of the upstream dam is set at the same elevation as the ____ of the downstream dam Bottom Top Sediment should be removed from check dams when it reaches ____ of the original height or before Half A floating turbidity curtain is designed to ____ sediment laden water and allow enough ____ for sediments to settle out of suspension Contain Time A type 3 floating turbidity curtain may be used in considerable flow conditions, meaning less than ___ feet per second or ___ knots 5 3 In flowing water, turbidity curtains should be placed _____/______ the direction of the flow, not ______/______ Parallel to/Along Perpendicular/Across Anchor lines shall be attached to ____ not the_____ Bouys Bottom of the curtain or float In tidal and/or wave conditions, there should be a ___ foot gap between bottom of the curtain and the floor of the water body at mean low water 1