Oil Tank - Leave it or remove it

[Jeremy Trier]

I am under contract for a multi-family in Pawtucket, RI and we are hammering out the details post-inspection.  The seller is pushing back on lots of the repairs I am asking for and I don't want to ask him to remove the oil tank no longer in use, but my father seems to think it's a terrible idea to leave it.  I have viewed many houses with oil tanks no longer in use that were capped and they weren't a problem. Both of my realtors said it should be fine, but I wanted to get feedback from you folks.  What do you think?  What's your experience?  FYI is was used this winter when they had to shut off gas due to separate circumstances.