This fall a two-man dredge not much bigger than an oversized pontoon boat began sucking mud from the bottom of the Fox River, whose gray-green waters run through 39 miles of dams, paper mills, and blue-collar cities before emptying into Lake Michigan at Green Bay.
The dredging, scheduled to go around the clock until the river freezes later this month, is a first step in what promises to be one of largest cleanups of contaminated sediments ever in the US. It could pump up 7.25 million cubic yards of river bottom - enough to fill five Empire State Buildings - and cost an estimated $400 million.
To people who live along the river, this marks long-awaited progress on an environmental and public health problem that has eluded a solution for 30 years. But the effort also has wider implications nationally and in particular for this region, where freshwater lakes and industry intersect.
Because of their size and position at the industrial heart of the country, the Great Lakes have a large number of contaminated sites. The one here - focusing on toxins from paper mills - is among 43 "areas of concern" identified in a US-Canada agreement, many of which contain contaminated sediments. Contamination also tends to persist in the lakes, in contrast to coastal areas where it can be washed out to sea and flushed out by tides.
"The Great Lakes as a whole are crying out for cleanup," says David Allen, a former US Fish and Wildlife Service official who surveyed pollution from the Fox River to Lake Michigan. "There's probably more to be done than resources available."
Still, many see promise in the simple hum of the hydraulic dredge here in Menasha, the up-river end of the contaminated area. Improved technology has made it possible to suck up the sediments. Work has begun here at one of the worst sites. And paper companies - who were faced with the threat of a federal Superfund lawsuit - have agreed to pay.
"It's been pretty slow," says Bob Garfinkel, who owns a bait and tackle shop in Green Bay, near the river's mouth. "We realize it's a big project, but it's the only responsible thing to do."
The project, indeed, could take as long as two decades to complete. The aim is to remove polychlorinated biphenyls (PCBs) as well as other industrial waste that accumulated on the river bottom.
PCBs in places like the Fox are a problem left over from largely successful efforts in the 1970s to clean up pollution in the nation's waterways. Despite the success, contaminated sediments remain in many rivers, streams, estuaries and harbors across nationwide. But with better technologies, widespread cleanup efforts have begun in recent years.
Stephen Ells, an expert on contaminated sediments for the US Environmental Protection Agency, says cleanups have begun at most of the 67 worst sites around the country. But progress is slow, and work has not begun on many. One of the best known projects, an effort to remove PCBs from 40 miles of the upper Hudson River in New York, still awaits the beginning of dredging.
Among the hangups: money issues, and uncertainty about how best to clean up polluted sediments. "There are still a lot of unknowns," Mr. Ells says. "If you're spending hundreds of millions of dollars, you want to be sure it's going to be effective. That's why no one's jumping into these things."
Fox River illustrates the costs, the time consumed and the political challenges. "This is a touchy one," says Green Bay Mayor Jim Schmitt. "You have the environment and you have industry, and we need both to build and grow the city."
The lower Fox is not only one of most heavily industrialized rivers in the Great Lakes region but also the site of the world's largest concentration of paper mills. Paper dominates the local economy, providing thousands of jobs and creating the kind of steady prosperity that many industrial areas would envy.
It also has transformed the Fox into one of the worst toxic sites on the Great Lakes. From 1954 to 1971 the mills discharged hundreds of thousands of pounds of PCBs into the river. That prompted a state warning to limit consumption of fish and ducks from the river.
Seven paper companies have accepted responsibility for the PCBs in the Fox. But questions remain about details of the cleanup and how much it will cost. The firms hope to avoid dredging as much as possible and instead to cover the contaminated sediments with thick layers of rock and sand - a method the EPA says is unproven and may not save money.
"We just want to make sure the cleanup is done in a logical manner with the best scientific resources available," says Patrick Schillinger, president of the Wisconsin Paper Council, which represents the companies.
Environmental groups say the paper mills have dragged their feet and that the federal and state agencies responsible for enforcing a cleanup have been too willing to compromise. So far, the paper companies have committed about $140 million in damages and cleanup costs, a small fraction of what the government says they owe.
One result of the delay in cleaning the Fox is that only about a fifth of the PCBs still remain in the river. Most have been washed into Green Bay, making the river the largest source of PCBs in Lake Michigan. These PCBs are virtually irretrievable, says Mr. Allen.
The delay has also prolonged a clear threat to public health. Fish advisories have failed to prevent many people from catching and eating Fox River fish, especially Mexican and Hmong immigrants.
The work that's started on the Fox will take six years and remove about a tenth of the PCBs. Officials hope that by then a second phase of cleanup will begin, focusing on the 90 percent of PCBs on the last seven miles of the river. That phase could take 10 to 18 years. It could take 20 years after that for PCB levels in fish to be safe.
For Scott Hughes, an electrician who lives within sight of the dredging here, the hope for progress is personal: "I'm glad to see them clean it up," he says. "I have a little kid, and I like it that when he grows up, he'll be able to eat the fish."