Brulen is correct. Gasoline has true potential for disaster. A small static electric spark has enought heat energy to ignite vapors. The more of it you have the greater potential for a large fire & explosion. Vapors burning back to a 55gl drum would be something not to be around. When a gallon or two is accidentally ignited filling a tank, the person involved usually is critically injured or dies.
If I wanted to have bulk gasoline stored, having it delivered to a 500 gallon tank designed for that purpose would be the safest method. Now days those tanks cost a lot due to the built in spill containment. It would be prudent to it keep away from buildings.
If you have the space you might get away with a storage shed 100′ away from other blds for drums. I would want the best pumps designed for flammables and use of grounding straps.