Wisconsin Mound Soil Absorption System and Area FillPractice Exam

For Area Fill mounds, what is the required depth to the Seasonal High Water Table?

1. 10 inches from the surface or deeper

2. 12 inches from the surface or deeper

3. 15 inches from the surface or deeper

4. 20 inches from the surface or deeper

The correct answer is: 12 inches from the surface or deeper

The requirement for the depth to the Seasonal High Water Table in Area Fill mounds is critical for ensuring proper function and longevity of the soil absorption system. A depth of 12 inches from the surface or deeper is necessary because it provides an adequate buffer to prevent the saturation of the absorption area, which can lead to system failure due to inadequate treatment of effluent. Maintaining this minimum depth above the Seasonal High Water Table ensures that the effluent can adequately infiltrate into the soil for treatment and allows for proper aeration of the soil. If the depth is less than 12 inches, there is a higher risk of effluent being unable to percolate correctly, leading to potential issues such as backup into living areas or surface water contamination. Thus, establishing a minimum distance of 12 inches is a standard practice in the design and regulation of these systems to protect public health and the environment.