Subsurface monitoring results during the big lost river infiltration within the Vadose Zone Research Park at the Idaho National Laboratory

The Idaho National Laboratory (INL) established a research facility to investigate the movement of water and solutes through the vadose zone. An improved understanding of the INL vadose zone will support ground-water monitoring, Wastewater Land Application Permits (WLAP), remediation of contamination sites, and constructing new facilities. The Vadose Zone Research Park (VZRP) is located at the new Idaho Nuclear Technology and Engineering Center percolation pond and includes a stretch of the Big Lost River. Data collected as part of an ongoing LDRD project being conducted at the VZRP captured water infiltration and redistribution from a 10-day Big Lost River flow event in June 2005. The data supports preferential-type flow behavior similar to percolation pond infiltration observations, rapid formation of perched water at various depths, non-sequential vertical and lateral water arrival, and a high degree of spatial variability in geohydrologic properties. Continued monitoring of hydraulic response to changes in the Big Lost River (BLR) flux, will aid INL and the Idaho Cleanup Project (ICP) operations in design and development of future waste disposal sites. The Big Lost River flow event and subsequent infiltration events will improve understanding of fluid transport and geochemical processes in complex heterogeneous vadose zones, and will provide a database of properties for development and validation of improved conceptual and predictive models.