Groundwater demonstration begins on Oak Ridge disposal facility project

The Department of Energy's Oak Ridge Office of Environmental Management (OREM) and contractor United Cleanup Oak Ridge (UCOR) have finished fieldwork and have begun monitoring groundwater elevations for a study at the Environmental Management Disposal Facility (EMDF) project site in Tennessee.

The facility, which is slated for completion in 2030, is considered a vital piece of infrastructure to provide the waste disposal capacity OREM needs to complete cleanup at the Y-12 National Security Complex and Oak Ridge National Laboratory. OREM's current on-site waste disposal facility is more than 85 percent full.

According to EMDF federal project director Dennis Mayton, fieldwork needed to be completed on time so that OREM and UCOR could begin collecting data when the wet season begins. In eastern Tennessee, the wet season typically runs from December through March.

"We're extremely proud of UCOR and their subcontractor CTI and Associates, who have completed this important project on time despite being on a tight schedule," Mayton said.

The work: According to the DOE's Office of Environmental Management, this latest work marks the second major phase for the EMDF project. This past summer, teams completed the first phase- early site preparation-five months ahead of schedule and $12.3 million under budget.

Fieldwork for the second phase of the EMDF project began in February. Workers cleared and recontoured more than 30 acres of land. They also installed a geosynthetic cover system composed of three layers: the geomembrane, turf, and sand infill.

The 1.3 million-square-foot geomembrane layer simulates the effect of lined disposal cells on groundwater elevations, creating an impermeable barrier over the site. The turf, much like grass, slows the flow of stormwater, providing improved stormwater controls. The final layer, sand infill, weighs down the turf and prevents damage from strong winds.

According to DOE-EM, this work allows OREM and UCOR to gather information about how groundwater elevations change, providing valuable information for the landfill's final design. Gathering data during the wet seasons is important because that is when groundwater levels are highest; there is more rain, and plants without foliage absorb less water.

UCOR and teaming partner RSI will monitor groundwater elevations over the course of the next two wet seasons through 2026. That data will be used to inform the final design and enable the final phase of the project, which includes EMDF's construction.

She said it: "Completing the cover system was essential to the start of the groundwater field demonstration and continuing progress on this project," said Mary Magleby, UCOR EMDF project execution manager. "The next two wet seasons of monitoring will support the EMDF design phase and move us closer to completion."