What should the slope of the embankment be below the water line in a WSP?

The correct answer reflects the recommended slope of the embankment below the water line in a Waste Stabilization Pond (WSP). A slope of 1 foot vertical to 2 feet horizontal is optimal for ensuring the stability of the embankment and preventing erosion. This gentler slope helps to provide adequate structural support to the embankment, reducing the risk of collapsing under the pressure of the water.

Additionally, this slope allows for better maintenance and inspection access while ensuring that water can flow properly within the pond. The gradual slope complements the dynamics of the pond system by minimizing turbulence that can lead to sediment disturbance or erosion.

In contrast, a steeper slope, such as 1 foot vertical to 1 foot horizontal or any variations that imply a more acute angle, might increase vulnerability to erosion and destabilization. A much gentler slope, like 3 feet vertical to 1 foot horizontal, could be undesirable in terms of space usage and retaining the area needed for effective functioning of the WSP. Thus, the chosen slope represents a balance between structural integrity, functionality, and maintenance efficiency in a WSP design.