CPESC Erosion Control Methods & Techniques 2

Question 1

Which erosion control blanket (ECB) category is most appropriate for slopes steeper than 3:1 with high rainfall intensity?

Accepted Answer

Category 4 (high-performance TRM)

Answer

Category 4 high-performance TRMs provide permanent reinforcement for steep slopes and high-velocity flows where lower categories cannot maintain stability.

Question 2

What is the primary mechanism by which polyacrylamide (PAM) reduces erosion when applied to bare soil?

Accepted Answer

It flocculates soil particles and increases aggregate stability

Answer

PAM works by binding soil particles together, increasing aggregate stability and reducing detachment and transport by water.

Question 3

A check dam constructed with rock riprap in a drainage swale is designed primarily to:

Accepted Answer

Reduce flow velocity and trap sediment behind the structure

Answer

Rock check dams reduce the velocity of concentrated flow, allowing sediment to settle out behind the dam.

Question 4

During which phase of construction activity is soil most vulnerable to erosion?

Accepted Answer

Site clearing and grading when vegetation is removed

Answer

Clearing and grading removes protective vegetation and disturbs soil structure, leaving bare erodible soil exposed to rainfall and runoff.

Question 5

What is the recommended maximum slope length for rolled erosion control products (RECPs) used without additional anchoring on a 4:1 slope?

Accepted Answer

It depends on the specific RECP and site conditions

Answer

Maximum slope length for RECPs varies by product type, soil erodibility, rainfall intensity, and slope gradient, requiring site-specific evaluation.

(CPESC) Certified Professional in Erosion and Sediment Control Practice Test

(CPESC) Certified Professional in Erosion and Sediment Control Practice Test

CPESC Erosion Control Methods & Techniques 2