Storm Water Pollution Prevention Plan (SWPPP) Practice Test

A fiber roll or wattle is intended to serve what primary function?

1. Improve water quality

2. Reduce erosion

3. Capture sediment from low and slow runoff velocity

4. Enhance vegetation growth

The correct answer is: Capture sediment from low and slow runoff velocity

A fiber roll or wattle is primarily designed to capture sediment from low and slow runoff velocity. This practice is essential in controlling soil erosion, particularly in areas where surface water runoff is gradual. The fiber roll acts as a barrier, allowing sediment to settle out of the water as it flows over the roll, thereby preventing it from being transported further down the slope or into water bodies. While some of the other options, such as improving water quality and reducing erosion, are indeed linked to the function of fiber rolls, they are secondary to the primary function of sediment capture. The design and placement of these structures make them particularly effective at slowing down the rate of water flow, which facilitates sedimentation. Additionally, the capture of sediment can indirectly contribute to better water quality by removing pollutants attached to the sediment particles, but the main intention behind constructing a fiber roll is its sediment retention capability. The enhancement of vegetation growth is not the primary function; rather, it is a possible outcome of successful sediment control and stabilization efforts, but does not reflect the primary purpose of the fiber roll itself.