How many feet of backfill must be placed between adjacent tanks and between tanks and excavation walls?

The requirement for backfill between adjacent tanks and between tanks and excavation walls is set to ensure proper structural support and safety. Specifically, placing a minimum of 2 feet of backfill helps to distribute the weight of the tanks evenly and provides adequate separation to prevent any potential damage during installations or in the event of tank movements or soil settling over time. Additionally, the 2-foot backfill layer acts as a buffer to mitigate risks associated with soil erosion and groundwater effects, which can compromise the integrity of the tanks and their contents. This two-foot minimum is commonly referenced in industry guidelines, contributing to overall safety and compliance within underground storage tank installations. The other measurements do not meet the regulatory standards for adequate protection and stability.