Heterogeneous sedimentary layering causes modeled transport parameters to be dependent upon the length scale, particularly in the vadose zone. In addition, factors influencing the rates and mechanisms of mass transfer between adjacent sedimentary layers of variant water content are not well understood. The goal of this research is to quantify flow and transport within individual layers in partially-saturated, layered sediments, and to determine the contribution of these individual layers to transport in a composite (e.g., multi-layer) system. Large, intact blocks of sediment (1 m x 1 m x 0.3 m) were collected from the Hanford flood deposits in Washington state. The samples were encased in a specially-designed aluminum container and porous fritted plates were affixed to the lower boundary. A suite of nonreactive (Br, PFBA, and PIPES) and reactive (U(VI)) tracers were applied at a point source. The progress of the tracers was monitored within individual layers, which were instrumented with combined tensiometer and TDR probes and solution samplers. The tracers were also monitored at five separate reservoirs at the lower boundary. The collection of large-scale intact sediments and the experimental configuration represent a significant advance in vadose zone studies because it interrogates the mechanisms governing mass exchange at the layer-scale. We will present initial results from this investigation, which will have implications towards modeling of fate and transport of contaminants in layered vadose zones.This research was funded by the DOE Office of Biological and Environmental Research. Oak Ridge National Laboratory is managed by the University of Tennessee-Battelle, LLC, under contract DE-AC05-00OR22725 with the US DOE.