Wisconsin Mound Soil Absorption System and Area FillPractice Exam

For an area fill mound, what is the prescribed slope ratio?

1. 2 to 1

2. 3 to 1

3. 4 to 1

4. 5 to 1

The correct answer is: 5 to 1

The prescribed slope ratio for an area fill mound is 5 to 1. This means that for every 5 units of horizontal distance, the mound rises by 1 unit vertically. This slope ratio is crucial for stability and drainage purposes, as it helps prevent erosion and allows for effective water absorption and management within the mound system. A slope of 5 to 1 is considered less steep compared to ratios like 2 to 1 or 3 to 1, which increases the risk of soil instability and runoff issues. The gentler slope also aids in distributing the load more evenly, reducing the potential for soil compaction that can occur with steeper slopes. Additionally, this ratio supports the overall design principles of mound systems, ensuring that the effluent can adequately infiltrate into the surrounding soil. In practical terms, a 5 to 1 slope allows for better vegetation establishment and maintenance, which further assists with erosion control and enhances the performance of the mound system.