What environmental conditions increase the risk of UST leaks?

The option regarding soil permeability and groundwater levels is correct because both factors significantly influence the risk of leaks from underground storage tanks (USTs).

Soil permeability refers to how easily fluid can flow through the soil. When the soil is highly permeable, it can facilitate the movement of contaminants if a leak occurs. This means that any leaked product can quickly reach the groundwater or spread laterally through the soil, increasing the potential impact on the environment.

Groundwater levels are also critical; in areas where the groundwater is close to the surface, there is a higher chance that any leaks could directly contaminate the water supply. Furthermore, high water tables can reduce the effectiveness of natural filtration processes that would typically mitigate contaminant spread, making it easier for pollutants to migrate from the source to the groundwater.

Together, these two conditions create a higher risk environment for UST leaks, as they can enable quick and extensive movement of substances from the underground tanks into the surrounding environment.