What should be done with exposed soils in a filtering practice to ensure stability?

Stabilizing exposed soils in a filtering practice is essential for ensuring the integrity and functionality of the stormwater management system. When soils are exposed, they are vulnerable to erosion from wind and water, which can lead to sediment runoff and compromise the filtering system's effectiveness. By stabilizing the exposed soils, measures such as vegetation, geotextiles, or other erosion control methods can be implemented to promote soil cohesion and prevent erosion. Vegetation, for example, will add root structure that holds the soil in place while also enhancing water absorption and pollutant filtering.

The other options present approaches that do not adequately address the risks associated with exposed soils. Leaving soils as is can lead to significant erosion and sediment loss. Covering them with heavy materials might create additional issues such as hydrophobic surfaces that repel water, preventing proper infiltration. Similarly, adding additional layers of fill may not provide the required stability and can introduce further complications without addressing the exposed soil condition directly. Therefore, the best approach is to stabilize the exposed soils effectively to maintain the function and efficiency of the filtering practice.