Wisconsin Mound Soil Absorption System and Area FillPractice Exam

What construction mistake can cause system failure related to soil?

1. Using inadequate drainage

2. Compacting natural soil

3. Not applying mulch

4. Using coarse fill

The correct answer is: Compacting natural soil

Compacting natural soil is a key construction mistake that can lead to system failure related to soil in the context of a Wisconsin Mound Soil Absorption System. When soil is overly compacted, its ability to absorb water diminishes significantly. Proper absorption systems rely on the natural permeability of the soil to facilitate the movement of wastewater and prevent the accumulation of excess moisture. Compacted soil can create a barrier that inhibits water from percolating through the soil layers, disrupting the intended function of the absorption system. This can result in surface water pooling, potential overflow, and ultimately lead to system failure where wastewater does not get adequately treated before it reaches groundwater. Other construction practices, like using inadequate drainage or using coarse fill, may also lead to problems, but the compaction of the natural soil is particularly critical, as it directly affects the fundamental absorption capacity that these systems depend on.