SFA project – Microbial Observatory – Rifle, Colorado. Near the town of Rifle, Colorado, lies the primary field site for Phase I of the Subsurface Systems Scientific Focus Area 2.0 (SFA 2.0, sponsored by the DOE Office of Biological and Environmental Research—BER). The site’s history as a milling facility for ores rich in uranium and other metals (such as vanadium, selenium, and arsenic) has resulted in low but persistent levels of contamination within subsurface sediments and groundwater. With the support of BER, Earth Sciences Division and their collaborators from the DOE Joint Genome Institute have conducted major investigations at the Rifle site, to facilitate integrated, field-based subsurface biogeochemical and microbial genomics research relevant to uranium mobility to improve the predictive understanding of subsurface flow and transport relevant to metal and radionuclide contaminants.