Unsaturated zone means the zone between the land surface and the regional water table. Generally, fluid pressure in this zone is less than atmospheric pressure, and some of the voids may contain air or other gases at atmospheric pressure. Beneath flooded areas or in perched water bodies the fluid pressure locally may be greater than atmospheric. Waste form means the radioactive waste materials and any encapsulating or stabilizing matrix. Waste package means the waste form and any containers, shielding, packing and other absorbent materials immediately surrounding an individual waste container.
Water table means that surface in a groundwater body at which the water pressure is atmospheric.