Styrofoam dissolves in gasoline (in the anarchist's cookbook this was a recipie to make "napalm"). I wonder if this opens up a new venue for terrorism: drill a hole and pour in some solvent or catalyst, watch as the hill collapses...
"Oh, I certainly hope no terrorists come, and pump oil directly under our facilities!"
"Yes, that would truly be a devastating blow!"
"We can only hope that no hostile actors from oil-rich nations learn about our critical vulnerability to this clever, effective tactic!"