Free CEPSCI Erosion and Sediment Control Measures Questions and Answers

Question 1

Sediment control structures such as silt fences most commonly trap sediment by the following means.

Accepted Answer

Slowing water to allow sediment particles to settle out.

Answer

Explanation:
Silt fences and similar sediment control structures primarily work by slowing down the flow of water. When water slows down, its ability to carry sediment is reduced, allowing particles of sediment (such as soil, sand, or other debris) to settle out of the water and accumulate behind the structure. This process effectively prevents sediment from being carried away by runoff and helps to protect surrounding areas from sediment pollution.
While silt fences do have openings that can trap larger particles of sediment, their main function is to slow down the velocity of water, which enables sedimentation. They are not primarily designed to prevent erosion or to act as physical barriers for vehicles, although they may serve these secondary functions to some extent depending on their design and placement.

Question 2

PAM is a chemical that is added to turbulent runoff primarily to achieve the following.

Accepted Answer

Cause flocculation that reduces sediment transport.

Answer

Explanation:
PAM (Polyacrylamide) is a chemical used in erosion and sediment control practices, particularly in controlling sediment in runoff from construction sites or disturbed areas. When added to turbulent runoff water, PAM functions by causing flocculation. Flocculation is the process where small particles in the water aggregate together to form larger particles (called flocs). These flocs are heavier and settle out more readily than individual particles, reducing the turbidity of the water and hence reducing sediment transport. This process helps to clarify the water by promoting the settling of suspended solids, which can then be trapped or filtered out more effectively by sediment control measures such as silt fences or sediment basins.

Question 3

The sediment control structure in the center-right side of the photo above is a:

Accepted Answer

Rock spillway for a sediment trap

Answer

Explanation:
A rock spillway for a sediment trap is designed to control sediment by allowing water to flow over a constructed barrier of rocks. This structure helps to slow down water flow, allowing sediment to settle out before water continues downstream. It's typically used in areas where sediment control is critical, such as construction sites, to prevent sediment from entering water bodies or stormwater systems.
In the context of erosion and sediment control BMPs (Best Management Practices), a rock spillway for a sediment trap is specifically designed to manage sediment runoff effectively.

Question 4

The main benefit of using mulches and ECBs is that they:

Accepted Answer

Provide instant cover

Answer

Explanation:
Mulches (such as wood chips or straw) and ECBs (Erosion Control Blankets) provide instant cover to bare soil upon installation. This immediate coverage helps to protect the soil from rain impact, reduce surface runoff, and prevent erosion before vegetation can become established. It is a critical initial step in erosion and sediment control on construction sites and other disturbed areas.
Unlike vegetation, which takes time to grow and provide cover, mulches, and ECBs offer an immediate solution to stabilize soil and prevent erosion during the early stages of project development. This early protection is essential for maintaining soil integrity and preventing sediment runoff into nearby water bodies or storm drains.

Question 5

When would a pipe slope drain (PSD) typically be used?

Accepted Answer

To direct water flow down the slope without causing erosion before stabilization.

Answer

Explanation:
A pipe slope drain (PSD) is used to safely direct water flow down a slope without causing erosion, especially in situations where the slope has not yet been stabilized or where permanent drainage structures are not yet installed. PSDs are designed to manage runoff and prevent erosion by safely conveying water away from sensitive areas until permanent stabilization measures can be implemented. They help to protect soil integrity and prevent sedimentation in nearby water bodies during construction or other land-disturbing activities. Therefore, option C is the correct answer as it accurately describes the primary purpose of a pipe slope drain.

CEPSCI - Certified Erosion Prevention and Sediment Control Inspector Practice Test

CEPSCI - Certified Erosion Prevention and Sediment Control Inspector Practice Test

Free CEPSCI Erosion and Sediment Control Measures Questions and Answers