Can your tanks be buried?
We have tanks specifically designed for burial, used primarily for septic and cistern tanks, but our standard above ground tanks are not designed for burial. The earthen load of the soil around an above ground tank wall will cause the sidewall to collapse. The only exception is if you build a vault and install the tank inside. A vault is a hole in the ground with reinforced walls (not supported by the tank).
Source: FAQs - Peabody