In dry areas where tank flotation is not a problem, what is the minimum depth of cover recommended for underground tanks?

The recommended answer indicates that a minimum depth of 1 foot of backfill plus an additional 4 inches of concrete is suitable for underground storage tanks in dry areas where flotation isn't a concern. This setup serves multiple purposes, primarily providing adequate structural support for the tank and protecting it against external forces, such as soil movement or impact.

Having both a foot of backfill, which typically consists of a granular material, allows for proper drainage and minimizes the accumulation of water around the tank. The additional layer of concrete enhances this protection further by creating a solid layer over the backfill that can withstand heavier loads, such as vehicular traffic or machinery above. This combination ensures that the tank has sufficient support while also contributing to its overall stability and integrity.

In contrast to this option, others may suggest less backfill or no concrete, which might not offer the same level of protection or structural support, especially in areas with changing soil conditions. Therefore, the combination of backfill and concrete is aimed at maximizing the operational safety and longevity of underground tanks in these environments.