Just north of Interstate 80, the UC Davis campus is a showcase of modern tastes: the Mondavi Center for the Performing Arts, its neighboring wine-and-food institute, a solar-powered housing complex, and gleaming new classroom buildings.

Just south of the freeway, in a rural area along Old Davis Road, sits a rambling collection of low-slung concrete structures, backed by scrubby vacant lots and surrounded by barbed wire.

Twenty years ago, workers hauled away the remains of nearly 800 irradiated beagles and dug up tons of toxic dog waste and contaminated gravel from the complex. They trucked much of it in metal drums to a nuclear disposal site in Washington state.

Today, UC Davis faces the prospect of a costly and prolonged cleanup at the federal Superfund site – a remnant of Cold War America and a legacy of the university's past.

"The technology then was dig a hole and cover it up," said Sue Fields, a manager with the university's Environmental Health and Safety Department who is supervising the cleanup project.

Old landfills at the site still contain toxic and radioactive waste. The university, the Davis community and the U.S. Environmental Protection Agency must now decide how best to proceed.

Fields said UC Davis officials expect to release a draft report this week detailing a range of options, from monitoring the groundwater to digging up the landfills and moving everything to a facility in Utah.

The cost could be anywhere from $6 million to $100 million, she said.

The 15-acre site on the rural south campus was once the Laboratory for Energy- Related Health Research.

UC Davis scientists conducted experiments there for the U.S. Department of Energy and prior agencies from the 1950s to the 1980s. Their mission: to study the possible effects of radiation from nuclear fallout.

They fed hundreds of beagles a diet laced with strontium 90, doused them in rays from cobalt 60 and injected them with radium 226. Then they froze their remains.

In one experiment, the beagles were exposed to cobalt 60 up to 22 hours a day, Fields said.

Fields said the research helped inform the ban on above-ground nuclear testing. Some of the tests were meant to study the development of bone cancer from low-level radiation. The experiments stopped in 1988 as the Cold War wound down.

Six years later, the U.S. Environmental Protection Agency declared the area a federal Superfund site and divided responsibility for its cleanup between the federal government and UC Davis.

The Energy Department completed its portion of the job in 2009. It spent two decades and tens of millions of dollars demolishing dog kennels, decontaminating buildings and digging up toxic sludge.

Now it's the university's turn.

The current phase of the cleanup deals less with the radioactive legacy of the beagle studies and more with decades of indiscriminate dumping by UC Davis in three unlined pits.

Beagle pens were built atop one of the primitive landfills; two others are nearby.

From the 1940s to the 1960s, waste from university labs and other parts of campus would be tipped into the pits and buried, said Fields.

The university caught a lucky break from nature.

Putah Creek flows south past the site into the Yolo Bypass wildlife area, but the creek has been largely unaffected, EPA and university officials said. Groundwater in the area moves away from the stream to the northeast.

Right now, the biggest concern is a plume of chloroform stretching northeast for more than a half-mile from the site, polluting soil and groundwater in adjacent agricultural land.

The chloroform was used as an anesthetic, Fields said.

Monitoring wells are already in place. A pilot project forces air into the soil to push the chloroform out, venting it skyward through a PVC pipe. Fields said 300 pounds of chloroform have been removed using the method.

Radioactive pollutants include tritium, a radioactive isotope of hydrogen, and carbon-14, also known as radiocarbon. Both were used in medical research, Fields said.

The substances are not especially mobile in soil, she said, so contamination has been limited to the area around the dump sites.

Carcinogenic chromium 6 is also on the U.S. EPA's list of contaminants that pose potential health risks at the site.

Some research suggests the chromium-6 may be a product of naturally occurring and nontoxic chromium-3 mixing with sewage and manganese beneath the surface and undergoing a chemical reaction.

Researchers are still trying to determine the source of the chromium 6 and how best to deal with it, Fields said.

As the university prepares to release its draft report, the EPA is embarking on a public outreach campaign and intends to hold community meetings.

Residents will have a chance to comment on the options before the EPA selects a cleanup plan, officials said. The state also will weigh in.

"We have the community phase so people will know what's going on there," said Kathy Setian, EPA's project manager.

G. Fred Lee, a Davis environmental engineer who advised a citizens group on the cleanup for 15 years, said he doesn't expect much public interest.

The Davis South Campus Superfund Oversight Committee disbanded about 18 months ago amid a funding dispute with the EPA, he said.

Few people live in the rural area, Lee said, and the contamination poses no immediate public health threat. "As long as you don't put a domestic well in there, you're all right," Lee said.

Even so, Lee, a longtime college professor, said he thinks it is important for citizens to monitor what the university does at the site. The area is not so far from the main campus, farmland and Davis residential neighborhoods, he said.

On Thursday, in the autumn sunshine, cyclists passed by on the Putah Creek levee trail, just yards from the once-radioactive research station. Goats bleated in an adjoining field.

The California Raptor Center, which helps injured hawks and owls, sits next door to the toxic site.

Lee says it's important to keep tabs on the cleanup and any future development in the area. "You have to have somebody watching the whole time," he said.

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