THIS year, thousands of Denver school children are taking nature walks through the Rocky Mountain Arsenal Wildlife Refuge. Bald eagles, herds of deer, and countless other species make their home here at a vast 27-square-mile area northeast of the city.
The trails the youngsters take, however, are not made by fauna but by the US Army. For the last half century this habitat has been a chemical-weapons facility and pesticide factory.
Now it is increasingly becoming a heated battleground for environmentalists and the Army, which is trying to transform the toxic site into a national wildlife sanctuary. Environmentalists accuse the government of cutting corners and say the area is a long way from being safe for humans or wildlife.
The Army says this is a pioneering effort making the best use of taxpayers' money in cleaning up contaminated land. As the first Superfund site in the nation to be converted to a wildlife refuge, it is being closely watched.
"The initial reaction was this is one massive public relations snow job," explains Adrianne Anderson, former regional director of the National Toxics Campaign and environmental ethics professor at the University of Colorado.
She says the military's decision to turn the site into a wildlife area was a mistake, done only so the US government could save hundreds of millions of dollars in cleanup costs.
"What we've done so far I consider a success story," says US Army spokesman William Thomas. "For those who say it's not safe enough to be a wildlife refuge, well, the wildlife have lived here some 40 years. We didn't bring them out here; they have been here all along. They've been thriving."
Already the US Army has spent $750 million cleaning up the arsenal and says when the job is done in 2010, about $2 billion will have been spent.
One source of contention is how clean the arsenal land must be to be considered safe.
"I don't think the arsenal will ever be clean," explains Jeff Edson, the arsenal project manager for the Colorado Department of Health. "The groundwater will take several centuries to cleanse itself naturally, so the Army will be treating the groundwater at the arsenal in perpetuity. And the soils on the arsenal will continue to have residual contamination for probably centuries as well."
Mr. Edson says that today, the arsenal is still a very toxic facility, pointing out that most of the cleanup has yet to take place.
"This is a Superfund site. People have to understand that over three-quarters of the arsenal may have to be dug up or tilled due to elevated levels of chemicals that exist in the soils. We are talking about the potential for destruction of the habitat."
But the Environmental Protection Agency has stated that the risk to humans and wildlife is "negligible."
"There's still stuff in the ground that we need to deal with, we know that," says Mr. Thomas. "It comes down to three things: Take down the old structures, deal with the soil, and continue to monitor and treat water that's going off the arsenal. We've got a long way to go. We [the Army] made the commitment to start cleaning this place up. We've done it so far and we'll continue doing it."
In 1942, the US Army acquired the land, just northeast of Denver, to make weapons. The Army manufactured chemical and incendiary weapons until the 1960s and then leased the 17,000-acre piece of property to the Shell Oil Company, which in turn manufactured pesticides on the site.
Both the Army and Shell dumped thousands of tons of waste from their production efforts on arsenal property - burying it or disposing the liquid waste in massive open basins. These methods of disposal were widely accepted at the time. The extent of contamination on the site wasn't realized until Shell stopped production in 1982, and the Army began cleanup operations, dredging up toxic pools.
"I'd come out of my house and get this whiff of stuff, and I could not breathe," says a woman who once lived in a mobile home across the street from the facility. By 1988, most people in the neighborhood moved away. Several filed lawsuits against the Army and Shell for personal injury claims. Most of settled their cases out of court.
The Army's cleanup of the site has involved incinerating tons of contaminated soils and stockpiling millions of gallons of liquid waste. Congress set aside the arsenal as a national wildlife refuge - making it off limits to residential building, which meant a savings in billions of dollars since cleanup standards would be significantly lower.
Currently, visitors to the refuge are limited in what they can see. No one is allowed near the chemical weapons factories and no one is allowed near those sites where toxic wastes are stored. Most tours are conducted by US Fish and Wildlife officers, from inside government vans. US Fish and Wildlife Service project leader, Ray Rauch, admits that wildlife today are being adversely affected at the arsenal.
He says when the cleanup is done early in the next century, those problems will no longer exist. But even after the cleanup, when the arsenal is passed from the Army to the Department of Interior, visitors will be restricted to certain areas.
Those restrictions aren't enough for Ms. Anderson. She says the waste should be stored on the site, but that the site should not be a wildlife refuge where, she says, both humans and animals will be exposed to harmful chemicals.
State health officials won't know the impact on wildlife for years, admitting it is more difficult to document wildlife health issues than those of humans. They also say that with the arsenal's proximity to other industrial areas and Denver, other factors could impact the deer and bird populations of the site.