It’s a beautiful, 60-degree day, the sky a cloudless blue. Spunn Road is lined by stately houses looking down on the historic main street of Jackson, California, the high peaks of the Sierra Nevada mountains visible in the distance. There’s a slight bend in the road—and there it is. A chain-link fence topped with barbed wired blocks access to a few dilapidated buildings and a 50-foot-tall rusting steel structure that, in another life, hoisted rock from the depths below. There’s a sign on the fence: TOXIC HAZARD KEEP OUT.
Argonaut Mine is located in the middle of the literal Mother Lode at the heart of California’s Gold Country region. It operated on and off from the 1850s until World War II. After that, the mine sat largely vacant as the town of Jackson grew around it. Today, the only obvious remains are the buildings and, visible across the valley, the remnants of the neighboring Kennedy Mine, which just beat out Argonaut for the title of the deepest mine in the state.
At Kennedy, the miners constructed an elaborate series of multi-story wooden wheels one can still visit today to lift the mine waste, called tailings, and dump it in the valley below. At Argonaut, they dumped the waste—full of arsenic, lead, and other heavy metals brought up from underground, as well as cyanide and mercury the miners added to help extract the gold—a few blocks away.
From the road, all that’s visible of the tailings area today is a large, muddy vacant lot, marked by no more than a small sign on a flimsy-looking fence. One can see where part of the fence was replaced last year after a drunk kid plowed through it.
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But the brown muck here is acidic and has average levels of arsenic, an element that can cause cancer, diabetes, cardiovascular disease, and skin lesions, of 400 parts per million. The level at which the state requires a site to be cleaned up is 100 parts per million. John Hillenbrand, a geologist with the Environmental Protection Agency, says he once recorded a value of 90,000 parts per million. Mercury and lead levels are also well above acceptable values.
At the bottom of the mining site, there’s also an old, four-story tall concrete dam, built in 1916 to prevent waste from the mine from flowing downstream. In 2015, the US Army Corps of Engineers declared the mine structurally unsound. If it failed, the agency said, it would send a 15-foot-deep mudflow past Jackson Junior High School, built directly below the dam, and into town. Within a year, Argonaut was listed on the National Priorities List, the list of so-called Superfund sites that are among the most contaminated places in the country.
Despite the cleanup at Argonaut being in the early stages, and the site being, as Hillenbrand describes it, “more straightforward” than most Superfund sites, the agency has already spent $8 million over the last several years. He says they have at least $14 million more to go.
And Argonaut is just one of thousands of abandoned mines littered across Gold Country.
Pre-1975, there was no state or federal law mandating cleanup of mining operations, and, in most cases, the miners or companies that operated these sites are long gone. Today, there’s an alphabet soup of state and federal laws and agencies that govern abandoned mines, but coordination is challenging, money is tight, and the projects themselves are complicated.
Though most abandoned mines aren’t toxic, those that are continue to leach out harmful contaminants like lead, mercury, and arsenic. Some are large, complex sites like Argonaut, requiring years of cleanup and millions of dollars. Many are smaller, left in the hands of under-resourced municipal governments or private landowners that are often unaware, unable, or unwilling to address the toxic legacy of mining.
“If you can’t see it, human nature is to minimize it,” says Hillenbrand. In Gold Country, though, where the history of mining is literally imprinted on the landscape, one would think it would be hard to miss. Yet because of money, legal wrangling, and local resistance, California has only just started to truly grapple with the toxic legacy of the Gold Rush and the threat it poses to people today.
Though gold is found throughout California, it’s the western foothills of the Sierra, a large swath in the central-eastern half of the state snaking along the north-south corridor of State Route 49 (named for the 49ers of the Gold Rush) that claims the title of Gold Country. With its rolling, oak-covered hills, expansive open space, and postcard-worthy historic towns, the region has become a popular destination for tourists and outdoor enthusiasts.
Yet, the region remains rooted in its frontier history, with countless reminders of the Gold Rush that gave birth to this quirky corner of the state. Towns have names like Emigrant Gap, Chinese Camp, and Rough-and-Ready, which seceded briefly in 1850 to avoid mining taxes and continues to celebrate ‘Secession Days’ each summer. There’s Sutter Creek, the ‘Jewel of the Mother Lode,’ and Placerville, nicknamed ‘hang town’ for a slew of Gold Rush-era public executions that took place there. In towns-turned-state-parks like Coloma and Columbia, one can give panning a try. Up the road in Nevada City, another 19th century boomtown, the community center is based in the old ironworks foundry, and a water cannon for hydraulic mining is prominently displayed in the town center.
Meandering along Highway 49, aptly called the Golden Chain Highway, one could believe that historic gold mining in the region was a rudimentary undertaking. Andrew Isenberg, a historian at the University of Kansas, describes the prevailing narrative of the period as that of a “windfall adventure.”
“People, they want to actually reenact this collective memory that we all have of mining as this environmentally benign thing that’s all kind of fun,” says Isenberg. But that’s a myth, he explains, pushing back against the very notion of a gold ‘rush.’ “That’s the romantic story,” he says. “In fact, gold mining is about the rise of industry in the United States.”
In reality, the deposits that could be excavated by hand in the Sierra Nevada were played out in a year. Of the tens of thousands of miners that descended on California in 1849, few ever found their fortune. Most went home. Those that stayed, though, developed increasingly invasive—and destructive—means of getting at the gold.
They dammed and diverted waterways to strain whole streambeds. They suctioned up bottom dirt from high alpine lakes and dug shafts deep into mountains of gravel above gold-bearing rivers. At the hydraulic mines, they washed away entire hillslopes with powerful water cannons, capturing nuggets of gold exposed within and leaving a slurry of mud, gravel, and mercury (added to the process to help bind with the gold) behind.
In some places, like Argonaut, miners dug to get at deposits of gold trapped in quartz veins deep underground. Contrary to the notion of a brief ‘rush’ in the 1850s, lode mining, as that method is called, took off in California much later and continued well into the 20th century.
According to Isenberg, people at the time understood the full impact of what they were doing.
“The industry is not really trying to hide this. They’re not saying that what they’re doing isn’t bad for the environment,” explains Isenberg. “They’re just saying, essentially, you got to break some eggs to make an omelet.”
It helped, of course, that, for over a century, no one would be held responsible for the damage.
Without any protections in place to require cleanup of mined lands, the Gold Rush—and the decades of invasive mining that followed—left a legacy of safety hazards and toxic contamination.
Today, the Department of Conservation estimates that there are roughly 47,000 abandoned mines across California, located across public and private land in almost every county in the state.
Experts admit that the 47,000 estimate is just that—an estimate. “For anybody to ever assert that there’s a determined number, a known number of abandoned mine features... it’s absurd,” says Scott Ludwig, the head of the Forest Service abandoned mine lands program. “I mean, every time we go out in the woods, whether it’s a trail crew, timber crew, or whatever, they find stuff.”
Hillenbrand at the EPA adds that the 47,000 number is also not helpful. “I don’t like that number. It’s just so intimidating,” he argues. According to Hillenbrand, the number “narrows down very rapidly” when one only considers sites that threaten public health. The Department of Conservation, for example, estimates that just 5,000 or so mines are contaminated.
“There’s a lot of mines, but we need to focus on sites that are close to people, that pose a real environmental harm,” says Hillenbrand.
But what exactly does it take for a vacant plot of land, or a pile of seemingly innocuous dirt, to pose a threat?
For the thousands of non-contaminated sites, for example, being clean isn’t the same as being safe. Every year, several people in California are injured or die in abandoned mines. People fall into shafts hundreds of feet deep. They stumble upon old explosives or asphyxiate on poisonous gases like carbon monoxide. They get bitten by rattlesnakes, trapped in derelict buildings, or lost in miles-long tunnels.
At the sites that are contaminated, meanwhile, contamination can mean a lot of different things.
Water flowing through old tunnels or waste rock left behind can produce acid mine drainage that’s highly toxic and corros Source: Gizmodo