Environmental Geomechanics covers a broad class of problems where deforming geomaterials are involved, usually coupled with fluid flow and transport of some substance. Transport of contaminants and other substances may occur in the fluids, e.g. water, water vapour and air, filling the pores of geomaterials as happens in waste disposal problems or durability problems. Mass transport also takes place in reservoir engineering problems, where the fluids involved are oil, water, and gas. All these aspects are addressed in this book together with a theoretical framework.