The objective of this study is to analyze flow within the vadose zone during a mid-scale hydrologic test to and to characterize transport processes in-situ. This project will employ numerical and experimental tools that have been developed under a previously funded EMSP proposal (project number 55332). Geophysical imaging techniques will be employed to image the changes produced by the transport experiments in-situ as they occur. Results will help to better understand flow and transport modes within the vadose zone at DOE sites, including the influence of natural heterogeneities and man-made structures. In addition the data will provide checks against which numerical flow and transport simulations can be compared.