I might have asked this before and maybe you folks could help. I am wanting to purchase a plastic 55 gallon drum from rural king to store water that was collected from the roof. This water would not be used for drinking but emergency use only for worse case scenarios. The problem, I haven't got a clue what was in them before. Was it syrup or roundup? It seems that these are food grade and once held....food. Any help would be greatly appreciated.... By the way, there is no odor of chemical from these tanks....I smelled several times.