If a hold down pad is used in the bottom of the excavation, what may the bedding depth be reduced to?

The use of a hold down pad in the bottom of the excavation allows for a reduction in bedding depth because the pad provides additional stability and support for the underground storage tank. The hold down pad is designed to secure the tank in place, preventing it from shifting or floating due to hydrostatic pressure or other external forces.

With this added support, the bedding depth can safely be reduced to 6 inches. This specification is based on industry standards and engineering principles, ensuring that the tank remains secure while still allowing for sufficient drainage and protection against settling or deformation of the surrounding soil. A bedding depth of 4 inches would generally be considered too shallow to adequately support most tanks without risking instability. The choice of 8 inches and 1 foot also exceeds what is necessary when a hold down pad is in use, as it is more than sufficient to meet the required structural integrity while still accommodating the pad.