I'd give you some ideas, but it means Sabotage on your part, and you probably feel bad about a certain Type of Contamination via Used Motor oils, and then even worse about having to call the EPA in to inspect the grounds....

But the Base of the building would be brought into question, and the builders would probably have to remove all of it then remove the top 16 Inches of soil, and it quickly gets very expensive....

And I would never suggest Sabotage or Environmental Sabotage either....