Iron Mountain Mine has been called "the beast." A place where the water is so toxic, scientists had to come up with new methods to measure its acidity. The mine was once the largest copper mine in California. It closed in 1966 and has been off-limits since then.
"They mined the property from the 1890s up until 1963 and throughout that period the mine changed in what it produced, but throughout a lot of its life it produced acid for the refining industry in the Bay Area," Rick Sugarek, project manager for Iron Mountain for the Environmental Protection Agency, said.
Iron, zinc, copper, cadmium all occur naturally at Iron Mountain. It is exposed to the 100 inches of rain that fall on Iron Mountain each year. Undisturbed they would not pose a problem.
"That flushes through the mine, that flushes the contaminates out of the mine, and into the rivers," Sugarek said.
Frequent overflows from a dam built in the 1960s to contain contaminated water jeopardized wildlife below.
State fish and game biologist Jane Vorpagel has been monitoring the toxic run-off from Iron Mountain Mine since 1986.
"Small amounts of copper and zinc can kill fish because they actually have to breathe it through their gills," Vorpagel said.
Iron Mountain discharges a ton of iron and zinc each day.
"That's like having 100 refineries in one location," Sugarek said.
Scientists estimate that the mine will continue to shed its toxic mess for at least 3,000 years.
The EPA took over operation of the mine in the early 1980s, declaring it one of the nation's first toxic superfund sites in 1983. Since then they have made significant strides in cleaning up the mess including the construction of a treatment facility built in the early 1990s.
"We've been able to take 98 percent of the contaminates out of what's been going into the Sacramento," superfund division director Jane Diamond said.
It is a lengthy process. Water that runs from the mine is captured downstream in a reservoir. It is then piped down to a treatment plant and into the largest sludge thickener in the nation. There the toxic goo is separated out and then sent to ponds to dry. At the end of summer it will be trucked back up the mountain and contained in this massive storage area. It is lined to keep the toxic waste from making its way back down the mountain.
"We've diverted clean water around the mine, so a lot of the water that would have been contaminated in the past, by the mine, doesn't get contaminated anymore and if flows fresh around the mine site," Diamond said.
In June, the EPA was able to dredge and remove sediments that had built up over the years downstream from the mine, minimizing the residual environmental impact. The project was slated to take four years to clean up, but thanks to funding from the American Recovery and Reinvestment Act they were able to move much faster.
The total clean up has cost the EPA about $100 million. Former mine owners have chipped in another $150 million for clean-up, with one exception.
"The ore body is loaded with copper, zinc, gold, silver and many, many, other elements," mine owner Ted Arman said.
Arman, 89, bought the mine in 1976. In an interview taped last year, he told a reporter that he has been battling with the government for years to resume mining operations and make money off his investment. He has floated ideas ranging from converting the toxic sludge into fertilizer to placing a 230-foot tall statue of Jesus on top of the mountain.
"The idea is taking Iron Mountain Mine's 3,000 acres and make it all a Garden of Eden," Arman said.
Earlier this year a federal judge ordered Arman to pay the government $57 million plus interest for the ongoing clean up. But the EPA's regional director says collecting that seems unlikely.
"The current owner does not have the financial where is all to meet those obligations imposed by the court so the next step, we really need to work through the court, and we'll need to determine what the outcome will be," Jared Blumenfeld said.
That may mean the government takes over ownership of the mine. Ultimately it will be up to a judge to decide.
Written and produced by Ken Miguel