What can excessively permeable soils lead to in mound systems?

Excessively permeable soils in mound systems can lead to the failure of the septic system due to their rapid drainage capabilities. When the soil is highly permeable, septic effluent can drain too quickly, not allowing adequate time for the biological treatment processes to occur. This can result in insufficient treatment of wastewater before it reaches the groundwater, increasing the risk of contamination and environmental harm. Therefore, the inability of the system to retain effluent for appropriate treatment is what causes the system to fail.

In contrast, soils that retain water more effectively allow for longer contact times with the soil, facilitating better treatment of effluent. Thus, excessively permeable soils disrupt this balance, leading to operational failures within the system.