Wildlife to Get Detoxified Home on Range : Environment: Contaminated topsoil on the site of a former chemical weapons arsenal must be removed first. But the cleanup may make some animals homeless.

If the Rocky Mountain Arsenal is one of the most polluted places on Earth, the bald eagles that hunt prairie dogs here don’t seem to realize it.

Nor do the mule deer, coyotes, hawks and songbirds that thrive on this grassy prairie preserve, surrounded by urban sprawl on the north edge of Denver.

“The contamination saved this place,” tour guide Ray Telfer tells a busload of senior citizens, who are still chuckling at his stories of growing up on a farm that was located on this very spot.

Paradox is a big part of the arsenal’s legacy. The wind-swept Army base was once used to manufacture lethal chemicals. As a result, it is on the Environmental Protection Agency’s list of most-contaminated Superfund sites.

But it is scheduled to become a national wildlife refuge.

This will happen only after an enormous, years-long cleanup dislodges and perhaps endangers many of the very animals the refuge is supposed to protect.

Birds and prairie dogs were noticed around the arsenal during its manufacturing days, but since operations shut down a decade ago, larger animals have moved in and multiplied. Biologists believe the arsenal may be near its capacity for deer, coyotes and several other species.

If that is true, many animals will have nowhere to relocate when vast areas of contaminated topsoil are removed to make the arsenal safe for human visitors and the 142 animal species that live here.

A noxious stew of arsenic, mercury, chlordane and other poisons is bound into one-third of the arsenal’s 27 square miles. When the contaminated soil is carried away, with it will go burrows, grazing areas, berry bushes and nesting sites. Some species could take years to recover.

Until then, by law the arsenal cannot become a wildlife refuge. Its well-guarded fence will stay put, wildlife will be herded out of some areas and visitors who come for free nature tours sponsored by the U.S. Fish and Wildlife Service will travel in buses.

Such constraints did not seem to bother the arsenal’s 50,000 visitors last year.

“The hunger of city people for contact with the natural world blew us away,” said Tom Doherty, chief of the National Wildlife Federation’s Western Division.

The contamination nightmare goes back half a century, to when the Army confiscated the land from farm families like Telfer’s to build a gigantic, top-secret, chemical weapons plant for World War II.

The factory also produced millions of gallons of toxic waste.

Pesticides were manufactured by Shell Oil Co. on a section of leased land on the arsenal grounds. The long list of killer products from this operation includes many that will linger in the environment for decades.

Poisonous fluids were stored in open natural basins, spilled onto the land or injected into deep wells. After decades the sludge left in one basin was still so toxic that birds died minutes after landing on it.

Denver remained unaware of the environmental horror developing on its doorstep until the toxins began turning up miles away, in water used for drinking and irrigation.

The nightmare lingers. Cleanup will cost the Army and Shell at least $2 billion, experts estimate.

Even before the refuge cleanup was contemplated, some decontamination had been started under the Superfund program.

Water birds returned to holding ponds drained of toxins. Beginning next spring, destruction of the poisonous residues will begin in a specially constructed incinerator.

Ground water is being treated at eight pump-out stations, which detoxify a billion gallons a year. But because contaminants bound in the soil will continue to leech slowly into the aquifer, total purification will take decades.

The largest remaining issue is how to detoxify so many square miles of contaminated topsoil. The EPA has cleanup standards for cases affecting people, but little research has been developed to set targets for wildlife. Shell and the Army cannot even agree on an approach to these studies.

“The law requires we protect both people and the environment,” says Connally Mears, head of the EPA’s oversight operations at the arsenal. “Standards are actually higher in some cases for animals than for people.”

The cleanup decision could have ramifications for 59 military bases scheduled to close before 2000. Many offer a last chance to save large tracts of open land in metropolitan areas. Wildlife enthusiasts see the potential for more refuges.

Pete Gober, the Fish and Wildlife official who pushed the idea of a refuge at the arsenal, says: “It may not appeal to the traditionalists, but we can’t continue to plan for the past.”