Erosion Control BMPs Flashcards
7 cards from real CESSWI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Erosion Control BMPs flashcards as text
What is the purpose of a tracking control BMP such as a stabilized construction entrance?
Answer: Reduce sediment tracked onto public roads by construction vehicles
Stabilized construction entrances use aggregate to dislodge mud from vehicle tires, preventing sediment from being tracked onto public roadways.
When is it appropriate to use a slope drain (pipe slope drain) as an erosion control BMP?
Answer: To convey concentrated runoff from the top to the bottom of a slope without causing erosion
Slope drains (pipe slope drains) safely convey concentrated runoff down steep slopes, discharging at the base with energy dissipation to prevent erosion.
A CESSWI inspector finds that an erosion control blanket on a 2:1 slope is not stapled at the recommended density. Which immediate risk does this create?
Answer: Wind and water can lift the blanket, leaving soil exposed underneath
Insufficient stapling allows wind or water to displace the blanket from the soil surface, creating gaps where erosion can occur.
What is the primary limitation of using straw mulch alone (without tackifier or netting) on slopes steeper than 3:1?
Answer: Straw will be displaced by wind and runoff velocity on steep slopes
On slopes steeper than 3:1, water velocity and wind forces exceed the stability of loose straw, requiring tackifier, netting, or blankets to hold mulch in place.
Which vegetative BMP is BEST suited for stabilizing the banks of a constructed drainage channel carrying intermittent high-velocity flows?
Answer: Turf reinforcement mat (TRM) with seeding
Turf reinforcement mats provide structural reinforcement to established vegetation roots, allowing grass to withstand high-velocity flows that would otherwise erode bare or lightly vegetated banks.
An inspector notices that sediment has accumulated to more than one-third of the height of a silt fence. What action is required?
Answer: The silt fence must be cleaned out or replaced to restore sediment storage capacity
When sediment reaches one-third of the fence height, the fence must be cleaned out because further accumulation reduces hydraulic head and risks failure from overtopping.
What distinguishes a horizontal slope drain from a standard pipe slope drain?
Answer: A horizontal slope drain runs along the toe of slope to intercept and redirect runoff laterally
Horizontal slope drains (also called diversion ditches or interceptor swales) run along contours at the toe or bench of slopes to intercept and redirect lateral runoff.