I'm a retired civil engineer and can confirm that you have been given some good advice. Many times the owner of the property at the time spills occurred has gone out of business and no long financial viable. It is safe to assume that if there was a leak then you will need to deal with contaminated soils. Removal of the soils from the site would be very expensive (excavation, impacts to existing utilities and structures can be problematic, haul to an approved/licensed landfill, fill with approved soil, etc.). Check with the appropriate environmental agency (Department of Environmental Conservation in NY) and ask if they have any spill reports. Soil testing will be needed to determine the area of impact and if any contamination has left the site run in the other direction. The property owner of the spill originating site will need to clean all contamination on his site as well as adjacent property. It is also highly likely that any new construction will need to include construction of a sub slab ventilation system which will keep any vapors from entering the existing or new structures.
If you are still interested I would start by asking the current owner to perform a phase one investigation to determine if there were reported spills and request soil tests before considering any purchase.
Please remember that the rules and regulations very state by state and at times even by different regional offices within a state.
As stated above this is free advise which is worth exactly what you paid for it.
