Contact the company that did the LUST removal and get their opinion. Many houses have these old tanks and it sounds like a legit company removed it. I would get more information before you kill the deal.
RpV Realty and Development
A sump pit picks up ground water from the perimeter piping. Depending on age and installation that ground pipe can be either under the basement floor or around the outside of the house. Since the oil tank is known to have been leaking into the ground, chances are some of the oil went into the ground pipe for the sump pit. Therefore you've got some residue in the pit.
- Maybe the previous company didn't clean the contamination fully or didn't clean the pit at all
- Maybe the previous company did a generally good job and this is just residual leaching into the system
Is the house going to burn down, be an EPA site or kill you? Probably not. Is there enough remaining oil in the ground to be a big issue? That depends on who you listen too. For some any amount of oil is a big deal. For others a small residual amount can be reasonably dealt with.
You could flush the pit a number of times and be done with it. That would probably work if it really is only a small residual amount. Granted flushing the system like that would likely be considered 'contamination' by some.
My recommendation is that you pay either the company that was there previously or another clean up company to come out, do a realistic assessment and make your decision from there.
Yes, having some old oil in the house isn't a good thing. However, I'd have to disagree that its a reason to run.
I would also try to make sure the water table/well is not affected.
Also, before you move forward with this deal, think resale. Will this issue affect you as a seller if you decide to sell the house 3-5 years down the road?
You might want to consider other homes.
Maybe your beagles can sniff out the problem? But seriously, I would keep looking. Unless this property is sold at a large discount, I would look at other homes. You don't want an oily stench seeping into your home.
I completely understand your concern! Get a really excellent home inspector and provide him or her with all the reports provided by the home seller. The home inspector during inspection should give you his or her opinion if you should have a full environmental study.
Best of Luck