CEPSCI Construction Site Best Management Practices 2 — Questions and Answers
Question 1: What maintenance is required for silt fence to ensure it remains effective?
- No maintenance is required once installed
- Regular inspection for tears, undermining, and sagging, plus sediment removal when accumulation reaches one-third of fence height (Correct answer)
- Only replacement after every storm
- Monthly inspections only
Correct answer: Regular inspection for tears, undermining, and sagging, plus sediment removal when accumulation reaches one-third of fence height
Silt fence must be regularly inspected for damage, and accumulated sediment must be removed when it reaches one-third of the fence height to maintain flow-through capacity and prevent overtopping.
Question 2: Where should silt fence NOT be installed?
- Along the perimeter of disturbed areas
- In areas of concentrated flow such as drainage channels or swales (Correct answer)
- On the downslope side of disturbed areas
- Around topsoil stockpiles
Correct answer: In areas of concentrated flow such as drainage channels or swales
Silt fence is designed for sheet flow conditions only; in concentrated flow areas the hydraulic forces exceed the fence's capacity, causing it to fail and potentially creating a worse problem.
Question 3: A soil stockpile on a construction site should be managed by:
- Placing it in the lowest area of the site to intercept runoff
- Surrounding it with sediment controls and covering it with mulch or tarps to prevent erosion (Correct answer)
- Leaving it uncovered to dry faster
- Placing it immediately adjacent to any nearby waterways
Correct answer: Surrounding it with sediment controls and covering it with mulch or tarps to prevent erosion
Stockpiles must be surrounded with sediment controls such as silt fence or berms and covered with mulch or tarps to protect exposed soil from rain erosion.
Question 4: What is the recommended maximum contributing drainage area for a standard silt fence installation?
- 5 acres
- 0.25 acres per 100 linear feet of fence (Correct answer)
- 2 acres per linear foot
- No limit if the fence is doubled
Correct answer: 0.25 acres per 100 linear feet of fence
Silt fence is designed for small drainage areas, typically no more than 0.25 acres per 100 linear feet of fence, because larger contributing areas generate flows that overwhelm the fabric's limited capacity.
Question 5: Vehicle tracking controls should extend from the paved road onto the construction site at least:
- 10 feet
- 50 feet or until natural road surface is reached (Correct answer)
- 100 yards
- The length of the largest truck on site
Correct answer: 50 feet or until natural road surface is reached
A stabilized construction entrance should extend at least 50 feet from the paved road surface to allow vehicles sufficient travel distance to dislodge mud from tires before reaching pavement.
Question 6: Which of the following is a source control BMP rather than a treatment BMP?
- Sediment basin
- Silt fence
- Phased construction limiting the area of disturbance (Correct answer)
- Sediment trap
Correct answer: Phased construction limiting the area of disturbance
Source controls prevent sediment from being generated in the first place by limiting disturbed area, while treatment BMPs capture sediment after it has been mobilized; source controls are always preferable.
CEPSCI Construction Site Best Management Practices 2
What maintenance is required for silt fence to ensure it remains effective?