Do you test removed Aboveground Storage Tanks?
The common statement we hear is people do not want to buy a home with an oil tank. You can dissect this statement by saying you do not want to buy a property where an oil tank leaked, and remediation is required. Because that is the real reason you don't want an oil tank.
People think if no tank is present, no leak. But in realty the oil may be below the floor and you don't know it. Curren visited the above site that had a leaking AST. We told the owner to remove tank and drill through the floor to test that the tank did not leak through the cracks in the basement floor. Owner never hired Curren, too scary of a proposition. 14 months later new property owner calls Curren, they have a lingering smell of oil in the basement, but when they bought the home it had been recently converted from oil to natural gas so how could oil smell still be present? They wanted Curren to do testing. Bingo we found oil below the floor, attorneys are now fighting it out with the old owner who covered up the tank leak.
Oil tank leak coverup. Photo below shows an oil tank that leaked, Curren removed the tank and cleaned the floor, advising that testing was required below the concrete.
The following photo shows the area where the leaking AST was located. Note the unpainted cinderblock wall on the right side of the photo. Note how stained the floor is on the right side of the photo from the tank leaking. FYI concrete is porous and you can't 100% remove oil if it has had time to soak into the concrete. 😒
Fast forward a month, and the walls have been painted and the floor cleaned up. You would never know by looking at the basement now that an oil tank leak occurred.
Now the question is did any of the oil leak below the concrete basement floor and impact the soils under the floor?
Well even with the tank removed and basement floor painted, the basement smelled of oil. The flipper who was selling (they only recently bought the house) the home called Curren. We advanced soil borings below the floor as we had originally recommended and found oil.
Note the round circles in the floor, there are bore holes advanced through the floor to look for oil in the soils. $8,500.00 later the oil leak was cleaned up.
Nothing lasts forever, and things can break. The photo below shows oil leaking from the valve on the lower side of the tank. Many tanks have an oil line that enters the tank on the lower side of the tank. This is a common area where oil can leak over time. Additionally this area can also have an oil fuel filter connected to the line. The fuel filter like the filter in your HVAC system or car needs to be changed periodically. So things get loosened and tighten, creating an opportunity for leak to leak from the tank. 
Now remember these tanks could be in place for 30, 40 or 50 years, an accumulation of drips over time can create a situation where soil remediation is needed.
Bottom line, if you are buying a home that had a heating oil AST what assurance do you have that the tank did not leak?
Is there a report from the removal company saying it didn't leak?
If there are cracks in the basement floor where the tank used to be, It's a good idea to test the soil below the tank, yes this involves drilling through the basement floor, but better safe than sorry.
If you have a house where an Aboveground Oil Tank was removed, you should have a professional evaluate the area to see if soil borings are warranted.
