Rather than excavating a Cold War-era landfill just outside Albuquerque, Sandia National Laboratories wants to leave the nuclear waste in the ground and "monitor" it indefinitely — and the state of New Mexico has agreed that’s a good idea.

From 1959 until 1988, Sandia used the site, now known as the Mixed Waste Landfill, to dispose of radioactive wastes such as cobalt 60 and depleted uranium, and hazardous wastes such as lead.

After studying the site for more than a decade under a federal law that requires the lab to take stock of contaminated sites, Sandia decided that excavating, inspecting, and moving the landfill would be too dangerous. "It’s dry waste, in a dry, functioning landfill," says John Gould, a physical scientist at the U.S. Department of Energy, which oversees the lab. "It’s not going anywhere."

Dick Fate, deputy project manager for Sandia’s environmental restoration project, says that neutron probes installed underneath the landfill will monitor changes, and that Sandia will excavate the site if it becomes necessary.

But the Albuquerque-based nonprofit Citizen Action has petitioned the New Mexico Environment Department to clean up the site after the short-lived radionuclides have decayed. "This isn’t a landfill; landfills are planned," says Citizen Action’s Sue Dayton. "This is a dump." She wants the waste excavated and placed in monitored storage. In August, however, the state issued an "initial approval" of the long-term stewardship plan, stipulating the addition of a 3-foot dirt cover and an animal-intrusion barrier.

The New Mexico Environment Department is currently accepting comment, and a public hearing will be held in Albuquerque on Dec. 2, 2004.