LEHR site — safe for daily use; cleanup effort reaches milestone with results of study

Two new reports by the UC Davis Office of Environmental Health and Safety say that the campus Superfund site, formerly a federal research lab and campus landfills, is now safe for limited use.

The revised human-health and ecological-risk assessments mark a key step in the effort to clean up the property, which was deemed unsafe by the U.S. EPA in 1994.

The rural 15-acre plot once housed the U.S. Department of Energy's Laboratory for Energy-Related Health Research, which conducted studies for more than 30 years on the effects of low-level radiation exposure in animals. Today, UC Davis employs about 100 researchers at the Center for Health and the Environment where the LEHR once stood.

"The site-wide risk assessment is a significant milestone in the Superfund process," said Brian Oatman, campus environmental protection manager. "Now we can move from site assessment toward evaluating and selecting final remedies."

UC Davis owns the land and leased it through the 1980s to the Department of Energy, which built and operated the LEHR buildings. The two institutions are sharing the cleanup effort, with the DOE handling all work pertaining to the LEHR, and UC Davis in charge of the landfills.

The Department of Energy used beagles, chosen for their relatively long lifespan, to test the health effects of long-term exposure to strontium 90 and radium 226 for more than 30 years. Their research contract expired in 1989.

Between 1992 and 2002, the DOE removed thousands of cubic yards of radioactive waste and contaminated soil, and decontaminated five research buildings. It also disposed of more than 350 outdoor dog kennels.

Contrary to popular belief, irradiated beagles were never buried beneath the site, but were instead stored in the facility's freezers after they died. Their bodies were removed from campus at the very start of the cleanup.

Beginning in the 1940s, UC Davis used the site's three landfills for campus research waste. They were closed in the mid-1960s.

The 1994 discovery of chloroform groundwater contamination from the landfills led UC Davis to install a treatment system to sanitize the water. It works by drawing water up from the ground, removing contaminants with an air-stripping process, then reinjecting it into the ground. UC Davis officials estimate that more than 80 pounds of chloroform have been removed from roughly 212 million gallons of groundwater since 1998. Today, the treated water is considered safe enough to use to irrigate nearby horse pastures.

The new risk studies determined that the site would not be safe for humans to live on, but it is suitable for its current use as a research center.

The studies say the health hazard to wildlife and plants on the site is greater than that to humans, however. Health risks are particularly high for certain species including amphibians, mammals and birds that eat plants growing on the site.

The risk assessments' results, together with future feasibility studies expected to be released in the fall, will be used to determine whether further cleanup efforts are necessary. Options include leaving the land as it is, placing restrictions on its uses and removing the remaining underground waste.

Oatman said he expects the former landfills will be capped with impermeable covers to prevent further water contamination, and to keep local wildlife from digging up harmful chemicals.

For now, however, U.S. EPA officials agree that the site is safe for daily use.

"Their current operations are OK," said EPA toxicologist Dan Stralka. "There aren't any current exposures that are unhealthy."

Media Resources

Amy Agronis, Dateline, (530) 752-1932, abagronis@ucdavis.edu

Primary Category

Tags