Certified Storm Water Operator Practice Exam

What is a limitation of sediment controls in construction?

1. They always reduce erosion

2. They rarely reduce runoff or erosion

3. They are too expensive to implement

4. They can only be used on flat surfaces

The correct answer is: They rarely reduce runoff or erosion

Sediment controls are designed to minimize the movement of sediment from construction sites into nearby waterways; however, it's important to understand their limitations. One significant limitation is that these controls typically focus on capturing sediment rather than addressing the root causes of erosion or runoff. In many cases, sediment controls, such as silt fences and sediment basins, might not effectively reduce the volume of runoff generated during rain events. While they can trap sediment already in motion, they do not inherently prevent runoff from occurring, which can lead to increased erosion elsewhere on the site or in surrounding areas. This means that although sediment control measures are essential tools for managing sediment, they do not significantly limit the overall runoff or prevent erosion from taking place on a more extensive scale. Understanding this limitation helps stormwater operators recognize the need for comprehensive erosion and sediment control plans that include various strategies both for controlling sediment and for minimizing the amount of runoff generated from construction activities.