CESSWI Sediment Control BMPs 3

Question 1

A construction site inspector finds silt fence buried under 18 inches of sediment. What is the CORRECT action?

Accepted Answer

Remove accumulated sediment and restore fence height

Answer

When sediment accumulates to one-third to one-half the fence height, it must be removed to restore the fence's storage capacity and structural integrity.

Question 2

What is the purpose of the J-hook or 'J-turn' method when installing silt fence at the ends of a run?

Accepted Answer

To prevent runoff from flowing around the ends of the fence

Answer

Turning the ends of a silt fence upslope in a J-hook formation prevents concentrated flow from bypassing the barrier at the fence endpoints.

Question 3

According to general CESSWI standards, what minimum freeboard should remain above accumulated sediment in a sediment basin before cleanout is required?

Accepted Answer

The basin should be cleaned when 50% of design storage is lost

Answer

Most design standards require cleanout when sediment has reduced the basin's design storage volume by 50%, ensuring adequate capacity remains for future storm events.

Question 4

Which BMP is BEST suited to slow concentrated flow in a vegetated swale on a construction site?

Accepted Answer

Fiber rolls or compost socks placed perpendicular to flow

Answer

Fiber rolls or compost socks placed as check dams in vegetated swales slow flow velocity and trap sediment without completely blocking the swale.

Question 5

What is the recommended maximum ponding depth behind a silt fence before the fabric is considered overstressed?

Accepted Answer

12 inches

Answer

Most silt fence installations are designed for a maximum ponding depth of 12 inches (1 foot); greater depths can cause fabric or post failure from hydrostatic pressure.

(CESSWI) Certified Erosion, Sediment, and Storm Water Inspector Practice Test

(CESSWI) Certified Erosion, Sediment, and Storm Water Inspector Practice Test

CESSWI Sediment Control BMPs 3