The water is treated in an aging plant before it reaches the Coeur d'Alene River. But if the plant ever fails "you'd have a catastrophic release of heavy metals to the river," said Mike Gearheard, EPA Superfund manager in Seattle.

EPA officials hope a cap over the main waste dump eventually will cut off rain and snowmelt carrying contamination into the ground water. But the Bunker Hill site still contributes more than half the zinc going into the Coeur d'Alene River -- about 1,400 pounds a day.

The 10-foot-wide trail, the result of a federal court-ordered cleanup agreement with Union Pacific Railroad, will be posted with hundreds of signs warning people not to wander onto the contaminated soil.

This month, the mining companies agreed to spend an additional $2.5 million by December, completing 70 more of the 700 yards awaiting remediation.

The yard cleanup delay forced EPA to defer other work while picking up cleanup on 100 of the properties, said Cami Grandinetti, EPA's Bunker Hill project manager. Before the yard problem surfaced, EPA had predicted cleanup would be finished this year.

When the project is done, EPA will able to say with confidence that it has protected people -- especially small children -- by greatly reducing lead pollution in yards, businesses and public areas, Grandinetti said.

But the site's worrisome ecological problems "are much more complex and long-term," she said.

A 'big and dirty' site

Does this mixed verdict mean the Bunker Hill project was a boondoggle?

No, congressional investigators say.

In 1999, the Bunker Hill cleanup was included on a federal list of "teenager" Superfund sites, a handful of places where cleanup had dragged on for more than a decade. Congress told EPA to push the laggard projects to completion.

Idaho's congressional delegation asked the General Accounting Office to determine whether Bunker Hill was bungled.

In a March 2001 report, the investigative arm of Congress said the cleanup has cost more than expected, but found no evidence of financial mismanagement.

The GAO calls Bunker Hill one of the nation's "big and dirty" sites where cleanup is a challenge and the major polluter went bankrupt.

The Bunker Hill smelter closed in 1981. When it was named to the Superfund list in 1983, it was the largest cleanup site in the nation.

The 7-by-3-mile rectangle along Interstate 90 is unusually complex. It contained five small towns with about 7,000 people; the 365-acre Bunker Hill mining and smelting complex; and 1,100 acres of polluted flood plains on the river.

The flood plains were tainted by millions of tons of mine wastes with an alphabet soup of contaminants -- antimony, arsenic, cadmium, copper, lead, mercury and zinc.

Smelter emissions and wind-blown dust contaminated thousands of yards with high levels of lead -- the most immediate health risk.

In 1983, more than 80 percent of the children in Kellogg and Smelterville and about 60 percent in Wardner and Page lived in homes with unsafe yards. A quarter of the preschoolers had worrisome blood lead levels.

Some of the lead came from the notorious 1973-74 Gulf Resources incident, when the smelter ejected 1,300 tons of lead oxide after company officials decided to run it with damaged emissions controls.

But that represents less than 5 percent of the total airborne lead released into the Silver Valley. Over its 64-year operations, the smelter spewed nearly 30,000 tons of lead, a 1999 technical report says.

Wind carried smelter emissions and soil-borne contaminants up and down the narrow valley, spreading pollution east to Wallace and west to Smelterville and Pinehurst. Periodic floods pushed mine pollution downstream.

The EPA has spent more public money on Bunker Hill than planned. It has also spent less on actual cleanup and more on studies and oversight than at four other comparable cleanups in Utah, Connecticut, Texas and Illinois. But there were good reasons, the GAO said.

Bunker Hill became an "orphan" site when Gulf Resources, the Texas company that owned the smelter complex, sought bankruptcy protection in 1993.

In Superfund talk, that's when the main polluter can't pay, forcing the EPA to take over and finance cleanup with money from the national Superfund account.

That raised the cost of labor by 40 percent because, under federal law, the EPA must pay union-scale wages when it's in charge. More than 87 experts and 600 contractors have worked on the project.

In the early 1990s, EPA and Idaho divided the project into two parts -- the towns where human health was most at risk from lead contamination and the rest of the site.

The surviving mining companies responsible for some of the cleanup agreed to tackle the towns in need of yard and small business cleanups, hiring contractors for the work.

EPA brought in the Army Corps of Engineers to clean up the nonpopulated areas -- the smelter complex, tailings impoundments, hills, ground and surface water, sediments, dust and some commercial properties.

In April 1995, EPA and the state of Idaho signed an agreement to spend $126 million on cleanup -- capping the state's share at $12.6 million. Superfund requires states to pay 10 percent of the cleanup tab.

EPA also obtained $33.2 million from four other companies responsible for pollution at Bunker Hill.

On-the-ground cleanup costs rose an additional $14 million, but that didn't change Idaho's share. A major reason for the increase: Idaho's insistence on minimizing the operation and maintenance costs it would assume upon completion.

Legal fees, EPA oversight costs and studies pushed the total spending to $212 million, the GAO says.

In addition, mining companies have spent about $41 million on yard and small business cleanups. They removed 2 feet of soil in gardens and 1 foot in yards where lead levels exceeded 1,000 parts per million -- or about a pint and a half of lead in one cubic yard of dirt -- the cleanup level agreed to for the project.

In the early 1980s, yard soils and house dust averaged two to five times the cleanup standard.

Health risk declines

In the mid-1980s, a local Superfund task force advising the EPA debated an extreme cleanup solution: Move the city of Kellogg.

"This town was built on mine tailings. Anywhere the river ran over 100 years, there's contamination. There was serious consideration given to moving the town, but people here said no," said Jerry Cobb, Panhandle Health District director.

The committee also explored scraping away all the contaminated dirt in the area and hauling it away.

The cost estimate: a whopping $169 million.

So the committee and the mining companies agreed on a less aggressive cleanup that cost about $41 million.

But cutting costs meant adhering to looser lead cleanup standards than at most Superfund sites. And it meant burying the waste in landfills within the valley rather than hauling it away for disposal. It was a controversial move.

The Silver Valley People's Action Coalition, a Kellogg group pushing for a lead health clinic, assailed the plan as a "massive compromise" that puts people at risk.

A Maryland engineer hired by the coalition with a $50,000 EPA grant said people should have been moved while their yards were cleaned, and he faulted EPA for choosing containment over waste removal.

But the yard work has achieved its central goal -- reducing lead levels in children's blood, Cobb said.

The cleanup is just shy of its goal of having 95 percent of all children below the federal safety limit for lead in blood.

"If we drop again this year, we are so low we can't push it further," Cobb said. "It's time to declare victory."

Children's blood lead levels decreased markedly from 1989 to 1991 as the highest-risk yards were addressed. But that downward trend stalled from 1992 to 1996 as new families moved into the area, renting homes with contaminated yards.

The Panhandle Health District's annual blood-lead survey found other avenues of exposure.

For instance, a 1-year-old in Kellogg in 1995 tested twice the lead safety limit. He spent part of his days in a day-care center that hadn't been cleaned up and with his grandparents, who lived in a house with a contaminated yard.

That same year, a 3-year-old tested three times the safety limit after his parents camped with him for the summer at Cataldo, where river sands and the flood plain have lead levels 20 times what's considered safe.

In 1996, several small children living in the Amy Lynn Apartments in Kellogg had elevated blood lead. A 4-year-old with lead five times too high was hospitalized and treated to reduce his blood-lead level.

The yard at the apartment complex had lead five to 10 times the cleanup limit. It was replaced later that year.

Overall blood-lead levels have dropped 50 to 60 percent since 1988, an April 2000 EPA review of the Superfund project said.

Wastes removed, trees planted

Rich Fink arrived in the Silver Valley seven years ago as cleanup manager for the Army Corps of Engineers.

The hillsides near the closed smelter complex were stripped of vegetation by decades of sulfur dioxide emissions. Gullies that once contained free-running streams were clogged 10 to 20 feet deep with mine wastes. Lead concentrations in the smelter complex were measured up to 100 times the cleanup goal.

"When I first went to Kellogg in 1995, I thought I was on the moon," said Fink, a construction engineer from Wenatchee.

Now, Fink calls the cleanup a major success.

The project dug up 30 percent more tainted materials than originally planned -- including enough waste from the gulches to fill more than 1 million pickup trucks.

The waste was consolidated into a few large impoundment areas. A four-acre lined cell with a leachate collection system was built within a 32-acre landfill at the old smelter site. It was used to hold the most dangerous heavy metals on the site.

Workers rebuilt Government Creek and Magnet Creek.

The corps hired Morrison Knudsen of Boise in 1995 to demolish more than 200 buildings in the industrial complex, including the zinc plant and the lead smelter.

Dispatching twenty 50-ton trucks, two huge excavators and 180 local workers, they disposed of the buildings and toxic dirt on the site.

On Memorial Day 1996, demolition experts blew up the smelter's two stacks, which towered 610 feet and 715 feet over the area.

Workers added nutrients to steep mountain slopes to allow crested wheat grass, Idaho fescue, lupine and yarrow to grow on the barren soils.

In September 1998, using Sikorsky sky crane helicopters, they sprayed the slopes with a glue-like substance called a "tackifier" that allows seeds to stick.

"It looked and smelled like Elmer's Glue," Grandinetti said. In all, they planted $8.5 million in vegetation on about 1,000 acres of hillsides. It is now spreading into a carpet of green.

About 1.75 million white pine seedlings had been planted on the hills by Gulf Resources before the corps started its work, but they remained tiny because of the soil's sterility.

More trees, including Rocky Mountain maples and mountain ash, were planted on more than 50 miles of terraces built by the mining companies to combat erosion. In all, 90,000 trees will be planted.

One of the most dramatic projects came in 1998. Cleanup managers temporarily moved a mile and a half of the Coeur d'Alene River up to a quarter mile out of its bed to remove 1.3 million cubic yards of mine tailings at Smelterville Flats.

"We dug a channel and shoved the river into it for a little over a year. It went really well," Grandinetti said.

The tailings contained between 48,000 and 90,000 tons of lead, a 1999 technical report says. They were replaced by clean fill to form the new river channel.

The tailings were hauled six miles east to the 260-acre Central Impoundment Area, a 1928 mine waste dump dubbed the "CIA."

Workers buried 22 million cubic yards of mine waste on the 60-foot tall CIA -- enough rock and soil to fill the former Kingdome three times.

To finish the job, they covered the huge mound with a thick plastic cap to keep rain from washing away more pollutants.

The project encountered problems with a subcontractor from Miles City, Mont. Last year, the Department of the Army and the EPA launched a criminal investigation of the landfill cap project.

There are allegations it wasn't installed correctly, Fink said. "We did an investigation to determine the liner's integrity. It's safe," he said. "But the fraud allegations are still under investigation."

Metals-laced groundwater still seeps under the CIA, but project engineers hope the cap will reduce the problem.

Recontamination a problem

Despite all the work, it's unclear whether the area will stay clean enough to protect future generations.

The project suffered setbacks when flooding carried more contamination into the Valley. A February 1996 flood was the worst since 1974; Shoshone County was declared a disaster area.

Forty-five Kellogg properties, 19 of which had already been cleaned, were contaminated.

In January 1997, the Superfund project office in Kellogg was flooded when a clay pipe carrying mine water ruptured, spewing sediments 6 to 8 inches deep across McKinley Avenue, one of Kellogg's main streets. The sediments contained lead nine times the cleanup level.

That same year, heavy rains and flooding in Milo Creek recontaminated 50 homes and about five miles of public right-of-way. Kids' blood levels shot back up at some of those homes.

The 2000 project review calls this a "unique problem at the Bunker Hill box" because the floodwaters carry so much mine waste. Towns and homeowners with limited budgets are ill-equipped to fix the damage, the report notes.

Kellogg Middle School has had some recontamination, possibly from blowing dust off the CIA near the school. And trucks going through the east gate of the former smelter site tracked out lead at concentrations four to six times above safety standards, the report notes.

The problems have stopped now that major earth-moving projects are finished, Grandinetti said.

Due to Gulf's bankruptcy, EPA owns 1,600 acres of Gulf's former property. It will be turned over to the state when cleanup is complete.

But a verdict on the cleanup's success can't be made for at least another five years. That's when the site will have stabilized enough for a clearer assessment, the GAO said.