Sediment Containment Systems (SCS) - Which drainage method is EPA recommended / most effective?

Sediment Containment Systems (SCS) - Which drainage method is EPA recommended / most effective?

• A. Filter bag
• B. Riser pipe outlet structure
• C. Skimmer outlet
• D. Sump

Answer: (C)

The idea being tested is how to remove the cleanest possible water from a sediment containment system, so sediment stays in the basin to settle rather than leaving the site. A skimmer outlet does this best because it pulls water from the surface where the sediment concentration is lowest, helping to minimize suspended solids in the effluent. This surface withdrawal also reduces disturbance of settled material and limits short-circuiting, keeping more sediment behind where it belongs and allowing clearer water to exit. In contrast, a filter bag can clog and impede flow, a riser pipe outlet can draw in more sediment from deeper layers, and a sump typically drains from the bottom where heavier sediment is concentrated. Therefore, a skimmer outlet is the most effective EPA-recommended choice for SCS drainage.

The idea being tested is how to remove the cleanest possible water from a sediment containment system, so sediment stays in the basin to settle rather than leaving the site. A skimmer outlet does this best because it pulls water from the surface where the sediment concentration is lowest, helping to minimize suspended solids in the effluent. This surface withdrawal also reduces disturbance of settled material and limits short-circuiting, keeping more sediment behind where it belongs and allowing clearer water to exit. In contrast, a filter bag can clog and impede flow, a riser pipe outlet can draw in more sediment from deeper layers, and a sump typically drains from the bottom where heavier sediment is concentrated. Therefore, a skimmer outlet is the most effective EPA-recommended choice for SCS drainage.