The Groundwater Quality Scientific Focus Area (SFA) at SLAC National Accelerator Laboratory is investigating biogeochemical redox processes that control uranium, carbon, and BCE behavior in alluvial floodplains in the upper Colorado River Basin and surrounding areas, emphasizing hot spots of microbial and geochemical activity in organic-enriched, redox-cycled sediments. Major scientific questions being addressed include:
- What are the physical, hydrological, and biogeochemical characteristics of NRZs and evaporite-rich sediments?
- What biological, kinetic, and thermodynamic factors control the speciation and behavior of uranium, organic carbon, and BCEs?
- How do NRZs interact with surrounding floodplain aquifers?
- What role does microbial nitrogen cycling play in mediating uranium redox cycling?
- What are the mechanisms and rates of uranium release to surrounding aquifers?
The project is supported by DOE’s Office of Biological and Environmental Research (BER), within DOE’s Office of Science, as part of BER’s Subsurface Biogeochemical Research (SBR) program.