How deep should backfill be placed during the excavation of the tank?

The correct answer for the depth of backfill during the excavation of a tank is typically 12 to 18 inches. This range is established to ensure that there is adequate support for the tank while minimizing the risk of settling or shifting that could compromise the tank's integrity.

Additionally, backfilling to this depth allows for proper compaction and stabilization of the soil without overstressing the tank structure. It is crucial for maintaining the structural integrity of both the tank and the surrounding soil, as excessive backfill could lead to increased pressure on the tank itself.

Furthermore, a backfill depth of 12 to 18 inches is also aligned with construction best practices and industry standards, ensuring safety and compliance during tank installation. It provides a sufficient work surface for installation procedures and helps to monitor any groundwater or environmental factors that may affect the tank's performance over time.