I got one of those last year for free from a company near here. They wash them clean and you can have as many as you want to haul. They get their raw product in the TOTE tanks and no one wants them back so they just stack up. They have to pay to get rid of them and welcome folks to come get them. They even give you an MSDS sheet for the former product although mine was clean as a whistle. I was going to use it to water with, but never did and finally gave it to my trash pick up man. Anyway as Chris said, they would make an excellent fuel tank, even has a shut off valve on the bottom. If I were looking for a fueling system, I would certainly look at those tanks, the top has an o-ring seal so water leakage would be nil. You may have to loosen the top when fueling to release the vacuum on it though, but with it being flexible, it shouldnt draw moist air in at night, just let the sides collapse a bit so less chance of condensate forming in the tank.
