What does Active Soil Depression (ASD) aim to achieve?

Active Soil Depression (ASD) is a radon mitigation strategy specifically designed to reduce radon entry into buildings by using mechanical means to depressurize the area beneath the structure. This technique involves creating a vacuum effect that pulls radon from the soil away from the foundation, effectively reducing the concentration of radon gas that can infiltrate the living space.

The process typically entails installing a venting system that draws air out from beneath the building, resulting in lower pressure in the soil immediate to the foundation. By maintaining this lower pressure, radon gas is less likely to enter the building because the negative pressure in the sub-slab area discourages radon from being drawn into the indoor environment.

In contrast, other options present different concepts. Increasing indoor air pressure does not directly mitigate radon and can sometimes facilitate its entry if not managed carefully. Creating a barrier against radon, while beneficial, refers more to physical barriers like membranes rather than active depressurization. Improving soil quality is unrelated to the primary goal of radon mitigation and does not directly affect the radon levels within a home. Thus, the objective of Active Soil Depression is clearly aligned with reducing radon entry through mechanical depressurization.