I'm not sure anything has been stored in them. I bought them from a member some time ago and went a different way never using them. I believe he only had water in them. The barrels are not drilled in any way and are both capped with the original bung plugs. I'll go out in the morning and pull them out of the barn and confirm condition and contents if any residual. I think the member I got them from needed something with a bigger opening for mixing. These barrels would present a cleaning issue for mixing, but are fine for RO storage or ATO feed.