Department of Water Resources
A daily compilation of significant news articles and comment
May 23, 2008
4. Water Quality –
One mussel, one world of trouble
The
Mercury Rising
Dealing With the Dark Legacy of the Gold Rush
Yubanet.com
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One mussel, one world of trouble
The
Annie Flanzraich /
Half a billion dollars spent on water-quality environmental improvement programs.
A century of environmental debate about how to protect the blue waters.
A bi-state compact and its two, soon to be three, regional plans to protect the fragile ecosystem of the 1,600-foot deep lake.
And one mussel, brought in through the crevice of a boat, could destroy every effort over the past 50 years to keep
"They will jam up drinking-water intakes, they will shed their shells and the beaches would not be usable, they (can) put drag on boats so boats have to constantly be cleaned. It could kill the economy and ruin recreational tourism based on the lake," said John Singlaub, executive director of the Tahoe Regional Planning Agency. "This should be of concern to everyone."
Quagga and zebra mussels are close cousins, members of the Dreissena family of shellfish. While the differences between the two are subtle - from appearance to ecological tolerance - the effect is the same. Once introduced into a body of water, these filter-feeders will eat the food and nutrients species higher on the food chain need to survive. In turn, they can destroy an ecological system and collapse an entire food web.
"If you remove the basis of that food web, everything dies," said David Britton, the assistant aquatic nuisance species coordinator for the southwest region of the U.S. Fish and Wildlife Service. "They will eat themselves out of house and home, and then they will start dying off as well."
Ironically, the introduction of quagga or zebra mussels to
"It's not a thing you would want in the lake," Roberts said.
The locustlike creatures can spawn continuously if conditions are amenable - some adult mussels can produce 1 million eggs in one spawning season. Once their life cycle is over, the mussels die off in large batches and their sharp shells can saturate beaches, making them unusable.
"You have accumulated mussels dead in the water all at once that creates quality issues, and have been known to have recreational impacts," said Ted Thayer, the natural-resource and science-team leader for TRPA.
They can attach to most surfaces with their byssal threads - including boat hulls, water intakes, lake floor and even other native mussels.
"I've seem them crawl around like snails," Britton said. "They will move around to get on new substrate."
In their larvelike stage, quagga and zebra can find safe haven in standing water in the bilges, live wells and motors of boats, and be easily transported from one area to another.
If they grow into water-treatment facilities, quagga and zebra mussels can clog pipes and cause millions of dollars in infrastructure costs.
Introduced to the
"They are the poster child for invasive species," Britton said. "They are about as nasty as you can get as far as invasive species go."
And once introduced to a body of water - one mussel larvae is smaller than a grain of sand - can begin an infestation that can not be eradicated, only contained.
"The best we could hope for is control," Thayer said. "Once you have them, you've got them."
History of the quagga and zebra mussels
Zebra and quagga mussels are native Eastern Europe with zebra mussels coming from the Black and Caspian seas and quagga mussels coming from the
Zebra mussels were first discovered in the
Europeans have been dealing with the mussels for 200 years by designing industrial facilities with the creatures in mind. The mollusks also have natural predators and controls in those ecologies. But in
The mussels were found in Lake Mead on Jan. 6, 2007, and later throughout
Most recently zebra mussels found in January in San Justo Reservoir, San Benito County - a mere 250 miles away from Lake Tahoe.
- Sources:
What are quagga and zebra mussels?
Both quagga and zebra mussels are part of the Dreissena family and are close cousins. Differences include physical appearance and ecological tolerance.
They can range in size from microscopic as larvae to about two inches long as adults.
They can life up to five years and can spawn constantly if conditions are amenable producing millions of off spring.
In their larval stage the mussels are free floating and carried with currents. As adults they use byssal threads to attached to hard surfaces, and can detach to move to new habitats.
Zebra mussels can survive in waters as warm as 86 F but survive best in 64 F water. Scientists are researching if quagga Mussels can survive in similar temperatures, but prefer 61 F.
Both zebra mussels and quagga mussels can survive cold waters near freezing, but cannot tolerate freezing - zebras need waters above 54 F in order to reproduce and quaggas need temperatures about 48 F.
To survive the mussels also need low salinity, high calcium content, high PH. Both breeds and survive in low oxygen concentrations.
They prefer to exist in environments with waters moving at low speeds and hard to attach to. Quagga mussels can tolerate living in soft sediments, but zebra mussels seldom do.
Zebra mussels are typically found from just below the surface to about 40 feet. Quagga mussels are typically found at any depth as long as oxygen is available.
Both species prefer to avoid light and are usually found in shaded areas or below the depth that light penetrates water.#
http://www.nevadaappeal.com/article/TD/20080523/NEWS/662340821/-1/REGION
Mercury Rising
Dealing With the Dark Legacy of the Gold Rush
Yubanet.com – 5/23/08
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
"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
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
"The
"The state's rules are forcing
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
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
"The Sierra is
"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
"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
"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
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
Private dredges working that stretch of the
"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
"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.
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."#
http://yubanet.com/regional/Mercury-Rising.php
Don Baumgart is a former daily newspaper reporter, was an Associated Press editor, and is now a magazine journalist living in
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