Certified Storm Water Operator Practice Exam

What can be added to sediment basins if maintaining the length to width ratio is not feasible?

1. Soil amendments

2. Baffles or convolutions

3. Vegetation

4. Siphons

The correct answer is: Baffles or convolutions

When maintaining the length to width ratio of a sediment basin is not feasible, adding baffles or convolutions is a practical solution. Baffles or convolutions are designed to enhance sedimentation by promoting turbulence and allowing for more effective sediment settling. These structures, typically constructed from materials like wood, concrete, or synthetic materials, are placed within the basin to create pathways that slow down water flow. This reduction in flow velocity gives sediment more time to settle out of the water column, improving the overall efficiency of the sediment basin. Additionally, by altering flow patterns, baffles can help to distribute incoming sediment more evenly throughout the basin, further enhancing sediment capture. In comparison, while options such as soil amendments, vegetation, and siphons can serve useful functions in different contexts, they do not directly address the issue of sedimentation efficiency associated with maintaining the length to width ratio in basins. Soil amendments may improve soil quality or stabilize slopes but do not primarily focus on sediment trapping. Similarly, vegetation can aid in sediment stabilization and can help prevent erosion, but it does not directly enhance the settling of sediment in the basin itself. Siphons are often utilized for water removal and management, but they do not facilitate sedimentation in the same way that baffles