BOISE, Idaho (AP) — U.S. officials say they have almost completed a lengthy project to dig up and remove radioactive and hazardous waste buried for decades in unlined pits at an eastern Idaho nuclear facility that sits atop a giant aquifer.

The U.S. Department of Energy announced last week that it removed the final amount of specifically-targeted buried waste from a 97-acre landfill at its 890-square-mile site that includes the Idaho National Laboratory.

The waste includes plutonium-contaminated filters, graphite molds, sludges containing solvents and oxidized uranium generated during nuclear weapons production in Colorado. Some radioactive and hazardous waste remains in the landfill that will be covered with an earthen barrier.