Sep. 18—State regulators have rejected the U.S. Energy Department's $12 million proposal to cap and cover unlined waste pits at Los Alamos National Laboratory and instead say the best option is for the agency to excavate it at an estimated cost of $805 million.
The federal agency's environmental managers contend covering the dumpsite in Area C with a 2-foot-thick, rock-and-dirt cap would not only be far less costly but also would be safer for workers, the environment and the community than digging up waste with radioactive material mixed in.
But the state Environment Department argues in a written statement excavating the site, while more expensive, would erase the hazards — including to groundwater — and wouldn't endanger workers if done correctly.
"Excavation will ensure that the source of contamination ... is removed," the Environment Department's opinion said. "It removes the source of contamination and eliminates the need for long-term monitoring and maintenance of the cover."
There will be a public comment period before the state issues a final remedy. Federal managers can request a hearing to challenge the state's conclusions.
The 75-year-old dumpsite was shut down in 1974 after taking in radioactive waste, caustic chemicals, treatment-plant sludge and a variety of trash, according to records. Critics contend the substances were never characterized during the Cold War to peg their hazards, creating a potentially toxic stew in unprotected caverns.
Two years ago, federal officials estimated the site contains 190,000 cubic yards of varied waste, and that about 240,000 cubic yards of material would have to be removed if the waste were excavated.
Area C's underground entrails consist of seven pits and 108 shafts, with concrete filling only 10 of the shafts.
The state's opinion echoes the concerns of environmentalists and anti-nuclear activists that the unlined pits could allow contaminants to eventually seep into groundwater, even though the aquifer is about 1,000 feet below the waste site.
A spokeswoman for the Department of Energy's Environmental Management Los Alamos Field Office wrote in an email the agency stands by its analysis that capping the old disposal site, combined with vigilant oversight, is the best choice.
"This recommendation would be protective of the health and safety of site workers, the environment and the public, including those who may live near, or use, the transportation routes that would be needed to dispose of excavated material," spokeswoman Stephanie Gallagher wrote. "It also utilizes techniques that have been successfully used at dozens of landfill sites in the arid environment of the Southwest, and at Los Alamos."