SVE has several advantages as a vadose zone remediation technology. Flowstones are formed via the degassing of vadose percolation waters. Many cave passages are formed by a combination of phreatic followed by vadose action. There are also problems in characterising the vadose zone (unsaturated zone). If the vadose zone envelops soil, the water contained therein is termed soil moisture. Above the water table is the vadose zone. During this vadose, or air filled state, abundant speleothem deposits formed. The primary coupling between groundwater and hydrological inputs is the unsaturated zone or vadose zone. This capillary action is the "upward movement of water through the vadose zone" (Coduto, 266). In essence, SVE is the vadose zone equivalent of the pump-and-treat technology for groundwater remediation.