The waste product left over from making olive oil might be valuable for making biofuels.
Olives: A Feedstock for Food, Biodiesel, Ethanol and Medicine : Greentech Media: "Pomace also contains chemicals that are toxic to soil: The Israeli government has begun to regulate how it can be disposed.
Approximately 5 percent to 7 percent of the total olive mass, however, can be converted to biodiesel. The olive stone can also be converted into cellulosic ethanol. In other words, two fuels can be made from one feedstock."