About the site

What is the ORFRC – site, facilities and equipment, resources [top]

The Oak Ridge Field Research Center (ORFRC) in Oak Ridge, Tennessee is located at the Y-12 National Security Complex. The ORFRC includes uncontaminated and contaminated areas in which research can be conducted. Contaminated portions of the site include a ground water plume that extends down Bear Creek Valley and contains uranium (U), technetium-99 (Tc), nitrate, thorium, and volatile organic compounds such as acetone, methylene chloride, toluene, and tetrachloroethylene. This plume originated with the former S-3 Waste Disposal Ponds, which were capped in 1988 and now are covered with asphalt and used as a parking lot. Nevertheless, the vast majority of contaminant mass migrated away from the Ponds, creating the extensive ground water plume as well as large secondary sources of contamination.


ORFRC facilities and equipment include dedicated drilling and other sampling equipment, support vehicles, a controlled atmosphere chamber for sample processing in the field, an equipment workshop, five field trailers/framed tents, refrigerators and freezers for sample archiving, two laboratories and analytical equipment (e.g., inductively coupled plasma mass spectrometry (ICP/MS), ion chromatography (IC), gas chromatography (GC), X-ray fluorescence (XRF)), a weather station, utilities such as power and water, and Internet connections are all available at the field site. The water table resides 0 to 4 meters below the surface and is readily accessible for coring, installation of ground water monitoring wells, pumping tests and reactive and nonreactive tracer tests. Staff working at the ORFRC have conducted over 5,000 feet of drilling, collected over 20,000 ground water and core samples, and shipped field relevant samples to DOE national laboratories and universities across the US and overseas.

Past (NABIR) and current (IFRC) research projects at the ORFRC have developed a website, listserver, and database that can be queried via the web to access over 40,000 pre-NABIR remedial investigation characterization data records and over 20,000 data records collected as part of the NABIR FRC characterization activities.

Real-world research opportunities [top]

Historical research, development, and testing associated with weapons production and related activities resulted in subsurface contamination that has been identified at over 7,000 discrete sites within the DOE complex. With the end of the Cold War threat, DOE shifted its emphasis to remediation, decommissioning, and decontamination of the immense volumes of contaminated ground water, sediments, and structures at its sites. DOE currently is responsible for remediating 1.7 trillion gallons of contaminated ground water, an amount equal to approximately four times the daily U.S. water consumption, and 40 million cubic meters of contaminated soil, enough to fill approximately 17 professional sports stadiums (Status Report on Paths to Closure, DOE/EM 0526, U.S. Department of Energy, Washington, D.C., March 2000). DOE also sponsors research intended to improve or develop remediation technologies, especially for difficult, currently intractable contaminants or conditions. (For more information see the ERSD Strategic Plan)

The ORFRC is like many DOE sites with its mixture of contaminant plumes and difficult hydrogeochemical conditions. For example, buried wastes in contact with a shallow water table have created large reservoirs of contamination. Rainfall patterns affect the water table level seasonally and over time. Furthermore, the hydrogeology of the area, with its fractures and karst geology, affects the movement of contaminant plumes. Plumes have migrated long distances to surface discharge points through preferred flow paths created by the fractures and karst conditions.

Remediation options are limited, especially for contaminated ground water. Moreover, current remediation practices for the source areas can affect biological, chemical, and physical processes that, in turn, may influence the movement of subsurface contaminants in unknown ways.

Past, current, and future research at the ORFRC can help DOE meet its real-world remediation challenges: site characterization, field experiments, and water and soil sample collection for use in laboratory-based research. Collectively, these activities will produce knowledge about the highly interactive natural processes that occur over a broad range of scales, thus controlling the fate and transport of contaminants.

Site contamination [top]

  • Liquid wastes (nitrate, metals, radionuclides such as uranium and technetium, other chemicals) were disposed of in four unlined ponds-the S-3 Ponds-from the 1950s until 1983

  • Plumes of contaminants flowed underground from the Ponds, creating extensive ground water contamination and large secondary sources of contamination

  • Ponds now are capped by an asphalt parking lot-capping prevents rainwater from directly infiltrating Ponds and releasing contaminants into surface and ground water

  • Rainwater infiltration (recharge) outside the cap (e.g., drainage ditch around Ponds) makes subsurface contaminants mobile in the watershed

Site allows watershed-wide research [top]

No other field research facility allows the investigation of subsurface contaminant fate and transport on such a large scale using a real-world, contaminated site.

Wastes travel through two main pathways in the ORFRC subsurface - shale saprolite (main pathway for nitrate and technetium) and gravel (main pathway for uranium)

  • Each pathway has different geologic, hydrologic, and microbial characteristics

  • Wastes discharge to Bear Creek and Maynardville Limestone, with its karst characteristics, then migrate further down the watershed

At the ORFRC, pH matters – uranium is highest where pH is low but more mobile in gravel where pH is high.

Major source zones and flow paths in the Bear Creek Valley watershed which encompasses the ORFRC.