CEPSCI Sediment Basin and Trap Design 2

Question 1

A skimmer outlet on a sediment basin is designed to:

Accepted Answer

Draw water from the surface of the pool to minimize turbulence and discharge the clearest water

Answer

A floating skimmer draws water from just below the surface, discharging the clearest, least turbid water while keeping the turbid bottom water retained for further settling.

Question 2

What is the purpose of installing an inlet energy dissipater or baffle in a sediment basin?

Accepted Answer

To dissipate the energy of incoming flows and prevent short-circuiting

Answer

Inlet energy dissipation structures reduce the velocity of incoming runoff to prevent resuspension of settled sediment and reduce the risk of short-circuiting through the basin.

Question 3

Short-circuiting in a sediment basin means:

Accepted Answer

Runoff flowing directly from inlet to outlet without adequate residence time for settling

Answer

Short-circuiting occurs when flow channels directly from the inlet to the outlet, bypassing the settling zone and reducing residence time, which dramatically reduces sediment removal efficiency.

Question 4

The emergency spillway of a sediment basin is designed to:

Accepted Answer

Safely pass flows from storms exceeding the design storm without causing basin failure

Answer

Emergency spillways safely convey overflows from storms exceeding the design capacity, preventing basin failure and uncontrolled breaching that could release stored sediment.

Question 5

Which soil property is most important when constructing the embankment of a sediment basin?

Accepted Answer

Adequate compaction and low permeability to prevent seepage and embankment failure

Answer

Sediment basin embankments must be constructed of properly compacted, low-permeability material to prevent seepage, piping failure, and embankment breaching.

CEPSCI - Certified Erosion Prevention and Sediment Control Inspector Practice Test

CEPSCI - Certified Erosion Prevention and Sediment Control Inspector Practice Test

CEPSCI Sediment Basin and Trap Design 2