Multi-Scale Mass Transfer Processes Controlling Natural Attenuation and Engineered Remediation: An IFC Focused on Hanford’s 300 Area Uranium Plume
Principal Investigator:
John Zachara, Ph.D.
Pacific Northwest National Laboratory
Field Site Manager:
Mark Freshley
Pacific Northwest National Laboratory
Co-Principal Investigators:
Gary Andersen (LBNL), James McKinley (PNNL), Don DePaolo (LBNL), Mark Rockhold (PNNL), James Fredrickson (PNNL), Yoram Rubin (U. CA/Berkeley), Roy Haggerty (Oregon State U.), Jim Szecsody (PNNL), Douglas Kent (USGS), Roelof Versteeg (INL), Alan Konopka (Purdue U.), Andy Ward (PNNL), Peter Lichtner (LANL), Bruce Williams (PNNL), Chongxuan Liu (PNNL), Chunmiao Zheng (U. Alabama).
ABSTRACT
The Pacific Northwest National Laboratory and a group of distinguished collaborators propose to use the Hanford 300 Area uranium (U) plume in waste management area 300 FF-5 as a site for an Integrated Field-Scale Subsurface Research Challenge (IFC). Multi-scale mass transfer processes are our scientific theme. A series of forefront science questions on mass transfer are posed for research which relate to the effect of spatial heterogeneities; the importance of scale; coupled interactions between biogeochemical, hydrologic, and mass transfer processes; and measurements/approaches needed to characterize and model a mass-transfer dominated system. Four site specific hypotheses will be evaluated that take advantage of the unique hydrogeologic attributes of the site. The hypotheses will focus on multi-scale mass transfer processes in the vadose zone and saturated zone, their influence on field-scale U(VI) biogeochemistry and transport, and their implications to natural attenuation and remediation. An innovative site has been designed that represents a transect from waste sources in the vadose zone, through contaminated aquifer regions, to final discharge to the Columbia River at the groundwater – river interface. Science and experimental collaborations, as well as leveraged facilities use and sharing are planned with an EM-22 project to evaluate the feasibility of polyphosphate-induced autunite precipitation to mitigate U(VI) discharge to the Columbia River. The IFC will proactively publish results in high-impact scientific journals, support collaborations with external ERSD (now CESD) investigators, and transfer data, knowledge, and coupled models to the Hanford site during and after the term of the project.
Experimental Test Plot at the Hanford 300 Area |
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Proposed design of the field experimental plot in the North end of the 300 Area. Characterization wells are drilled to 10’ and finished at 4’. Monitoring wells are drilled to 4-6’ and finished at 2’. Seasonal water table gradients and flow paths are noted. |
