Summary for stainless steel storage tank Discussion
Stainless steel storage tank absorption risks are the main concern in this thread, where Vale Wefer asks whether a dug-up stainless tank that previously held diesel and may have been cleaned only superficially could still contain harmful residues. He wants to reuse it for waste vegetable oil, possibly with occasional mixed fuel, and asks whether it should be heated, used as-is, or discarded. Mr. Mooney replies that without a clear history or chemical analysis, nobody can guarantee the tank is free of dangerous contaminants, but he thinks it is unlikely to have anything unsafe to burn if it is basically empty and was last used for diesel rather than food storage. He notes that the main serious concern he can think of is PCB contamination, which would matter if the tank had been used with transformer oil or was actually a transformer housing. Vale confirms it will not contact food and will only store filtered waste vegetable oil or fuel.
Q. Hi everyone not sure if anyone here can answer this question or not, but here goes. Several years ago I received a stainless steel tank it had been used for diesel transport, storage, and dispensing by a defunct land grading company, well I found the other day they had actually dug up the tank a few years before they gave it to me, it was found underground at a job where they cleared and graded the lot, well one of the previous tenants there was a pest control business.
The grading company cleaned it up (how I don’t know maybe just a wash job?) and welded some drains and fillers/bungs in it. I’m wondering any of you would know if it could happen to have residual harmful chemicals on/in it. It did have a few years of use as a diesel tank. Should it be fired/heated to burn anything left on? Use it as is? Dispose of it, and if so how?
I would like to continue using it to store waste vegetable oil to be used as tractor fuel.
Vale Wefer
Just a regular Joe – Dalton, Georgia, USA
September 13, 2019
A. Hi Vale. With neither a clear history nor a chemical analysis nobody can assure you of the tank’s safety in terms of either its construction material or trace amounts of dangerous contaminants (I think you already realize this).
However, I would say that since it’s not being used for any sort of food storage, and it was most recently used for diesel fuel, and (I assume) it’s basically empty, it would be quite unlikely to have anything unsafe to burn. The only chemical I can think of offhand that would be serious trouble would be PCBs (the oil in power distribution transformers used to contain PCBs and that was very bad news). If you are reasonably confident that it’s a tank, not a transformer housing, and that it wouldn’t have been used to collect PCB-bearing oil from or for transformers, I personally wouldn’t worry about it … that’s a personal philosophy, not an expert opinion ⇦ huh? 🙂
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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September 2019
Mr. Mooney, Thank you for the timely response! I am certain that it was pest control business in that building, and you are correct in that this won’t have any contact with any food related item in the future. It will only serve to store and dispense used filtered waste vegetable oil. or possibly occasionally an accidentally mixed batch of gas and diesel fuel.
Vale Wefer [returning]
– dalton, Georgia
September 17, 2019