Mercury Rising: Dealing With the Dark Legacy of the Gold Rush

Published on May 23, 2008 - 9:04:17 AM

By: Don Baumgart, Sierra Citizen

When gold recently touched $1000 an ounce, the mainstream media ran stories about Sierra gold panning concessions that were experiencing a business boom. The glitter is still glamorous, but behind the shine lies the Gold Rush legacy of darker chemical remnants: mercury, lead, arsenic, and asbestos.

More than 150 years after James Marshall saw a sparkle in the American River that started a worldwide rush to California, the cleanup of those potentially harmful byproducts is just now being addressed.

"Stepping back and thinking about how much work there is to be done on this issue, it's huge," Dr. Carrie Monohan said. Monohan is a hydrologist consulting on several mercury contamination projects in the Sierra. "It's mind boggling!"

There are an estimated 47,000 abandoned mine sites on public lands in the Sierra, according to Monohan. "There are years of field work to be done just locating those and assessing what type of hazards they represent."

One of the more useful elements for collecting gold in the 1800s was mercury. Today it is one of the most prominent mining toxins in the Sierra Nevada.

The silvery metal commonly was dumped into Gold Rush creekside sluice boxes where it bound with finer-grained gold into an amalgam more easily removed from the box's sediments. When hydraulic mining created a great deal more slurry, more mercury was added. Some of the mercury got suspended in the water and transported downstream. Much of it is still with us.

Cleaning Up History

"There's a 20 to 30 percent loss rate of mercury to the environment," Monohan said. "An estimated 26 million pounds of mercury were used to extract gold from the ore in California during the Gold Rush. An estimated 10 million pounds of mercury were lost to the environment. A lot of it washed downstream and destroyed agricultural fields as it emptied into the Sacramento River Delta. There's still a lot of it left up here, and we can still see it sparkling in the creeks today."

"The County of Sacramento is estimating it will cost them between a half billion and a billion dollars to install new filters on the water systems to take out more mercury," Elizabeth "Izzy" Martin, CEO of the Sierra Fund, said.

"The state's rules are forcing Sacramento into that mode. They're a hundred miles down from the problem and trying to filter it out. Sacramento would very much like to come up here and clean up the mercury because they think it will probably be cheaper to clean up four hundred pounds of mercury up here than it will be to filter out two pounds of mercury down there."

A report published in March by the Sierra Fund describes what was left behind from the Gold Rush and how little we know about it. "Mining's Toxic Legacy" both summarizes current information and calls for more.

"We're interested in reaching out to all of the environmental health officers, all of the planning department directors, the planning commissioners, irrigation districts and water agencies, saying 'We know there's a problem; we suspect you know there's a problem'" Martin said. "We need to design some solutions that we can bring to the State of California."

Martin has spent a year working with state legislative leaders and reports, "Not one of them had heard anything about left-behind gold mining toxins." She has met with the State Secretary of Resources and briefed individual legislators. "Now what we want to do is educate the people of the Sierra."

"The obvious environmental impacts were all that anybody thought happened," Martin said. Hydraulic mining blasted Sierra hillsides creating sediment-choked riverbeds until legal action shut down the big water cannons.

Affecting Our Health

"Now the health problems are finally coming out," she added. "This is the first report ever done on the scope of the Gold Rush and its impact on the modern era, and particularly on the threat to human and wildlife health."

Martin calls the Sierra Fund report an "information bomb."

"We're living on top of elements that we know cause cancer and birth defects. We know that the toxics are here, we know what their health effect is on humans, and we've not looked to see if there's any relationship between us living on mining rubble and health effects. We think that's a really important piece of information." The Sierra Fund hopes to get the money to develop that knowledge.

"We're not the Centers for Disease Control. We're not going to do the end-all, be-all study," Martin added. "We're just hoping to shine a light on the Gold Rush. The main purpose of this study was to say ‘Look, State of California, we're still living on the toxic piles left behind by the Gold Rush. You need to come up here and help us figure out how to clean this up.' "

"The Sierra is California's watershed, and it affects everybody in the state," Martin continues.

"We want to document the problem. We want people to understand there's a big problem. We want to move people forward toward solutions. We're interested in having people understand that we can actually solve this one. We can clean this one up."

"We were so pleased to discover that most of the involved scientists while alarmed, really feel that something can be done."

"A lot of people living up here now don't even know there was a gold rush. They weren't raised here, didn't go to school here so they don't know anything about it. They don't know the gold rush left behind toxins."

"Currently, these toxins are accumulating in reservoirs and becoming more available to the food chain. The bright spot is that investments in restoring the free-flowing characteristics of our Sierra rivers can be leveraged toward removing toxic sediments from our waterways."

The general effects of mercury and arsenic on humans are known, but specific case evidence is not being collected. The Sierra Fund's report is an effort to educate caregivers about the importance of this data and to encourage them to collect it.

"We don't know anything about how mining toxins actually are affecting us," Martin said. "There's no evidence that the arsenic in the soil up here is causing a problem; there's no evidence that it isn't causing a problem. Is there any sign in our hair and body tissue of high levels of arsenic?

"We need to create a health research project that will look for people who are living in areas of the Sierra where we know there are tailings and then go test them."

"We're calling for better mapping of places where naturally occurring asbestos was disturbed by gold mining."

"I kept waiting for someone to do something about this," Martin said when asked about the call for improved health care records relating to the big three: mercury, arsenic, and asbestos.

"We hired the Chico School of Nursing to go out and see if anybody is taking those simple pieces of information. No, it wasn't being done," Martin said.

"It doesn't matter whether the patient is a recreational miner or a firefighter, you need to know when someone is coming in with an illness what they might be exposed to," Martin said.

"If the doctor doesn't ask what you do for a living, they're not going to make the right diagnosis."

One project aimed at discovering more is being conducted by Friends of Deer Creek looking at mercury content in abandoned mine sites on Nevada City property. A $200,000 grant from the federal Environmental Protection Agency (EPA) is funding a three-year investigation of the hazards posed by these former mines.

"We have selected five abandoned mine sites for assessment," Dr. Monohan said. Monohan is serving as consultant to Friends of Deer Creek.

The group is looking at the movement of mercury down the watershed. "We're looking at mine waste piles that are along the creeks and how they erode into the creeks during storms," Monohan said.

"We're looking for chemical contamination or physical hazards." They're finding mercury, arsenic and lead. There is no asbestos on those sites. Asbestos comes from serpentine gravel, and Nevada City doesn't have much serpentine.

"Once that is completed we will apply for implementation funds (from the EPA) to do remediation on those properties so they can be cleaned up and returned to open space for recreation," Monohan added.

"This is very important research that needs to be done, looking at how mercury gets into the food chain." A great deal of money has been spent looking at the problem in the Delta, "But that research has not been conducted up here. And we have five to ten times higher levels of mercury and therefore a much greater potential for exposure. It's absolutely imperative that we advance the research."

Studying the Yuba Watershed

Hirshman's Pond, recently acquired by Nevada City, is one of the sites selected for study by Friends of Deer Creek. The pond is below a hydraulic mining site and is a mine waste pit.

Using the force of water against hillsides, hydraulic mining brought down a slurry that was channelled into sluice boxes where mercury was added. Much of the mercury remains.

For the past year SYRCL has been working with diverse stakeholders, including public land management agencies, to develop the first Watershed Assessment for the entire Yuba.

"In diagnosing the health of the Yuba Watershed and her rivers, the residue of the Gold Rush touches everything," says Jason Rainey SYRCL executive director.

A Bureau of Land Management (BLM) project will begin in August where Humbug Creek drains from Malakoff Diggins State Park into the Yuba River. Malakoff was the site of major hydraulic mining during the Gold Rush. The location is considered to be a mercury hot spot, and BLM is conducting a suction dredge test.

Private dredges working that stretch of the South Yuba River seeking gold have recovered large quantities of mercury.

"BLM is interested in looking at techniques for cleaning the mercury out of the sediment," United States Geological Survey (USGS) hydrologist Jacob Fleck said.

"The BLM dredge test will be conducted from bank-to-bank at one location in the river to mimic a systematic cleanup effort," Fleck added. "The role of the USGS is to monitor the impact of the dredge activity on water quality, sediment reactivity, and biotic mercury levels near the cleanup and downstream."

"We are investigating the impact of the use of dredging technology for a systematic clean-up effort in a mercury-contaminated area."

"Even if you collect 98 percent of the mercury from the sediment, if you are increasing its surface area through the process and mobilizing mercury, you could be creating a bigger problem downstream."

Knowing the impact of suction dredging used as a clean-up tool is considered crucial to the potential use of this technology for recovery and restoration efforts in all mercury-contaminated river sediments.

When hydraulic mining was halted, the Gold Rush went underground.

Lead and arsenic are both naturally occurring metals found with gold. "When the ore was brought up from the depths of the earth," Monohan said, "it was pulverized and processed, extracting the gold and leaving the lead and arsenic."

Piles of crushed rock tailings containing dangerously high levels of toxins accumulated as waste from stamp mill operations once the search for gold moved from creeks to rocks.

Those toxins are being found in tailing piles, waste rock piles, and in crumbling building foundations. "Cement foundations dating from the Gold Rush can still be found, and they are disintegrating," Monohan added. "That cement was made with mine tailings, and as it crumbles the toxic elements are released into the environment."

"We've finished the assessment for one of the five sites," Monohan said of Friends of Deer Creek's project. Field work will be conducted this summer on the four remaining sites, and the organization will apply for their first implementation grant either this fall or fall of 2009.

Finding a Solution

Monohan also is involved with a mercury reclamation project at Nevada Irrigation District's Combie Reservoir. "This is a project going on right here to remedy mercury contamination."

This pilot project is being led by NID to address the mercury-contaminated sediments building up in the reservoir. It's using a new technology, mercury extraction equipment, that takes the contaminated sediment and spins it at 60 to 80 times the force of gravity, throwing the mercury out. "It's a fantastic project to apply this new technology and address this legacy issue," Monohan said. "The process cleans up not only the reservoir but also the downstream environment."

"At this point, no one is opposing this; everyone is working together on it from so many different angles."

Referencing studies by the U.S. Geologic Survey, Rainey says, "Federal scientists have know for a long while that reservoirs are hot spots for mining contamination in the food chain.

"However, they're also finding that the tail waters just below dams and turbines are also hot spots for spikes in methylmercury, for example. They're not certain why, but dams seem to be at the center of the problem."

She believes assessment and cleanup of Gold Rush mining wastes is a project whose time has come.

Adds SYRCL's Jason Rainey, "A decade ago state and federal agencies identified salmon and steelhead passage at Englebright as one of the best opportunies to recover wild populations of salmon in California. Status quo interests have often cited the toxic sediment behind the dam as a justification for inaction on salmon restoration.

"I suppose that means leave the problem simmering underwater and let the next generation deal with it. Why aren't local people chiming in unison to the state: 'let's restore our salmon heritage and clean up this mess at the same time?' "

Speaking of the urgent need to restore public lands blighted by abandoned Gold Rush mines and their residue, Monohan said, "As development continues in the Sierra at this rapid pace, these remaining open space lands are no longer rural and they are needed for recreational activity."

A lot of money is going to be needed to support the cleanup of these sites by various agencies.

California taxpayers already have agreed to spend money on water quality, Martin said, by passing Proposition 84. "I'm arguing that a significant piece of that water-quality bond money should be used to clean up the Sierra watershed, which provides more than 60 percent of the state's drinking water."

Then, she feels, it will be easier to go to the federal government, which owns half the watershed land in the Sierra, and say to them, "We're cleaning up our part; we need you to clean up yours."

Speaking of the Friends of Deer Creek project, Monohan summed up, "The fact that we have a project on the ground to address the abandoned mine sites is so novel an approach, and it should be repeated in cities across the Sierra."

"The gold rush was of immense value to the nation," Martin concludes, "and yet they have brought nothing back to clean up the mining sites. If we rural people who are living in the gold mine areas don't design the solution, the solution will not fit the problem."

Don Baumgart is a former daily newspaper reporter, was an Associated Press editor, and is now a magazine journalist living in Nevada City. He has written articles for national publications including Better Homes & Gardens, International Railway Traveler and Porthole cruise ship magazine. He writes an ongoing series of articles about the Gold Rush, "Becoming California" which can be found at www.ncgold.com.

You can read The Sierra Fund's, "Mining's Toxic Legacy" online at: http://www.sierrafund.org/campaigns/mining

Reprinted with permission from The Sierra Citizen, a publication of the South Yuba River Citizens League.

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