Wisconsin Mound Soil Absorption System and Area FillPractice Exam

The slower the permeability, what will happen to the basal loading rate in a mound system?

1. It will increase

2. It will decrease

3. It will remain constant

4. It will fluctuate

The correct answer is: It will decrease

In a mound system, the basal loading rate refers to the amount of wastewater that can be effectively distributed over the soil interface per unit area without causing saturation and minimizing environmental risk, such as groundwater contamination. Slow permeability means that the soil has a reduced ability to absorb and transmit water, which can lead to a higher retention of effluent at the soil surface. When the permeability is low, the rate at which effluent can infiltrate into the soil decreases. Consequently, the basal loading rate must also decrease to ensure that the effluent is adequately treated before it moves deeper into the soil layers. If the loading rate were to remain high in context of slow permeability, it could saturate the surface and lead to ponding or runoff of effluent, compromising both the efficiency of the treatment process and environmental safety. Thus, in such scenarios, the appropriate response is to lower the basal loading rate to match the infiltration capacity of the soil, preventing potential malfunction of the system.