I just watched "Grease" on the History Channel's 'Modern Marvels' series. It was a very interesting 60 min. documentary. They were slopping grease on everything from aircraft carriers to elevators in order to keep things running smoothly. I have a question that I don't think the show covered: What eventually happens to the expended grease? i.e., evaporates? biodegrades? any effects on groundwater, etc.?