What is a potential risk when installing a mound system over excessively permeable soils?

The potential risk of installing a mound system over excessively permeable soils primarily lies in groundwater contamination. Mound systems are designed to treat wastewater through a series of layers that filter and break down contaminants before they are absorbed into the soil. When the underlying soil is highly permeable, it can allow wastewater to pass through too quickly, reducing the effectiveness of treatment and increasing the likelihood that untreated or inadequately treated effluents will reach the groundwater. This can lead to the contamination of the aquifer, harming both the environment and public health.

In contrast, other options such as underground flooding or insufficient drainage might occur in different contexts or scenarios but are not directly related to the permeability of the soil influencing the effectiveness of wastewater treatment operations. Increased maintenance needs may arise from various factors; however, the primary concern with excessive permeability remains the threat to groundwater quality.