Idaho Site Moves Closer to Returning Landfill Site to Native Desert Landscape

IDAHO FALLS, Idaho — U.S. Department of Energy Office of Environmental Management (EM) crews are working to safely demolish the largest remaining structure used in a project to retrieve targeted buried waste at a Cold War-era landfill at the Idaho National Laboratory Site.

The efforts by EM and cleanup contractor Idaho Environmental Coalition (IEC) to remove the facility are essential to eliminating risk to the workforce, public and the environment. The work also helps pave the way to the eventual closure of the 97-acre landfill, known as the Subsurface Disposal Area (SDA), returning the site to its native desert landscape.

The structure undergoing demolition, known as Accelerated Retrieval Project (ARP) VIII, is a large, soft-sided facility, enclosing more than three acres of the landfill. It was constructed to contain radiological and hazardous elements of buried legacy waste as it was exhumed.

Crews decontaminated the structure’s inner lining, which spanned several thousand square feet. Next, radiological control technicians ensured the material met stringent radiological control standards. Workers then applied a thick paint-like fixative to effectively “trap” remaining contaminants. That fixative has been effective in containing contaminants during demolition of other ARP structures.

Crews also conducted additional radiological surveys and regular air samplings to ensure any contamination remained fixed.

Nathan Bridges, Radiation, Protection, Safety and Health (RPS&H) senior manager at IEC, said such efforts are essential to safely completing demolition of ARP VIII.

“From radiological surveys to active decontamination, everything we do is focused on removing risk,” Bridges said. “And our workforce is successful, having safely demolished four similar ARP structures since 2022 without any incident.”

Water is applied to the facility’s floor and surrounding area to reduce the likelihood of dust travel during demolition.

“These steps are an important part to preventing unwanted dust and debris dispersion when the ARP is eventually pulled down,” Bridges said.

Debris generated from ARP demolition activities is immediately placed and buried in the landfill. Crews will place a protective overlay of nearly 25,000 cubic yards of soil — approximately 2,000 truckloads — over the ARP VIII demolition area.

ARP deactivation and demolition is a complex process that takes several months, but the workforce is experienced and able to work safely and address challenges efficiently. Bridges noted that the key to a successful and uneventful demolition is close coordination among employees.

“From the planning stage to completion, it will take approximately one year and tens of thousands of work hours from dozens of employees to demolish ARP VIII,” said Bridges. “In my 20 years of experience, I have not worked with a crew as skilled, efficient and productive as the people we have in Idaho.”

The ARP VIII demolition is scheduled for completion this summer. Crews will then work to demolish ARP IX and VII. EM and IEC expect to complete demolition of all remaining ARP facilities by the end of this year. There were seven in total.

Demolition of the ARP structures is necessary before construction can commence on an estimated 130-acre earthen cover over the landfill. The project will require an estimated 250,000 dump-truck loads of soils and rocks to be installed as the final step in remediation of the area.

In 2008, the DOE, U.S. Environmental Protection Agency and state of Idaho agreed to exhume targeted waste — such as plutonium filters, graphite molds, sludges, and a potentially reactive form of uranium — from a combined area of 5.69 acres from the SDA footprint. This remediation was completed in early 2022, approximately 18 months ahead of schedule.

-Contributor: Carter Harrison