Abstract: An underground storage tank with backfill deflectors is provided to permit installation of the storage tank underground without requiring any workers to enter the excavation. The backfill deflectors are preferably elongate, and generally the same length as or longer than the storage tanks with which they are used and are installed on the bottom of the excavation on either side of the tank. The deflectors have walls which are sloped or inclined in a direction which tends to direct backfill dumped thereon underneath the storage tank. Desirably, the deflectors direct the backfill under the tank without requiring any of the workers to enter the excavation to shovel the backfill underneath the lower portion or haunches of the tank. After a sufficient level of backfill is introduced into the excavation and directed under the tank by the deflectors, the backfill is vibrated to achieve a compacted backfill under the tank which is sufficient to support the tank.