Canada: Mount Polley mining disaster caused major changes to ecosystem

Published by MAC on 2015-05-06
Source: CBC News, Statement Mining.com

Study Documents Impacts of Tailings Impoundment Spill on Quesnel Lake

http://www.unbc.ca/releases/36934/study-documents-impacts-tailings-impoundment-spill-on-quesnel-lake

5 May 2015

Prince George, BC – A new research paper documents the physical and chemical characteristics, location, and extent of a sediment plume within Quesnel Lake for the first time since a mine tailings pond breach in August 2014, and discusses the initial and potential long term effects of the breach on the Quesnel Lake ecosystem.

The paper is co-authored by five UNBC researchers and their collaborators. The impact of a catastrophic mine tailings impoundment spill into one of North America’s largest fjord lakes: Quesnel Lake, British Columbia, Canada, was published online by the journal Geophysical Research Letters on May 5.

UNBC researcher Sam Albers collects samples. Download high-resolution image.

UNBC scientists Ellen Petticrew, Phil Owens, Sam Albers, Stephen Déry, and Nikolaus Gantner collaborated closely with researchers at the University of British Columbia and the Department of Fisheries and Oceans (DFO) to produce this paper.

Researchers used historic in-lake mooring data, newly collected data, as well as publicly available information from the British Columbia Ministry of the Environment, Environment Canada, and the Mount Polley Mining Corporation to compare pre-breach conditions to changes in the lake following the catastrophic failure of the tailings impoundment on Aug. 4, 2014.

UNBC researchers were amongst the first on scene, owing to the proximity of the Quesnel River Research Centre to the location of the breach. The QRRC is located 23 kilometres from the Mount Polley Mine (eight kilometres as the crow flies) and 10 kilometres away by boat from where Hazeltine Creek enters Quesnel Lake.

“The advantage of having a strong group of scientists who were already collaborating on other projects in Quesnel Lake, was that we were able to respond quickly to implement sampling,” says lead author and UNBC Geography Professor Dr. Ellen Petticrew. “Knowledge of lake movement drives the chemical conditions which influences biological exposure is extremely important information for assessing and responding to an unplanned disaster of this scale and enabling us to evaluate the impact on the aquatic ecosystem.”

The study reporting on results from Aug. 4 through to Oct. 4 found:

• A lake level rise of 7.7 centimetres was accompanied by a temperature increase of 1 to 2.5 C at the bottom of the lake.

• The turbidity of the water column was increased in the West Arm of Quesnel Lake, indicating the existence of a sediment plume at depths below 30 metres.

• Ultra-fine sediments remained suspended (394 cubic metres representing a surface area of about 1,000 square kilometres).

• The rocking of the water column, or seiching, redirected the plume towards the North and East Arms of Quesnel Lake, as well as towards the lake outflow, Quesnel River.

• Copper concentrations in sediment samples collected from Quesnel Lake and Quesnel River are elevated, often above sediment quality guidelines for freshwater ecosystems.

The researchers also identify knowledge gaps and stress the need for continued monitoring to determine what lessons can be learned.

“UNBC researchers from the Prince George campus and the Quesnel River Research Centre led the way by acting immediately to study the impact of the tailings pond breach,” says UNBC President Dr. Daniel Weeks. “Ongoing analysis is crucial and UNBC researchers are committed to thoroughly investigating Quesnel Lake and documenting the post-spill environment.”

The study involved close cooperation with scientists from across British Columbia and involved graduate students and technicians. It was supported by Forest Renewal BC, DFO, UBC, and UNBC.

The full paper is available at: http://onlinelibrary.wiley.com/doi/10.1002/2015GL063345/abstract

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Contact Information

Sam Albers
Manager, Quesnel River Research Centre
250-790-2031 - samuel.albers[at]unbc.ca

Peter James
Communications Officer
250-960-5420 - peter.james[at]unbc.ca

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Mount Polley spill shows increase in temperature, sediment levels: UNBC report

Researchers say data provides context, but doesn't predict long term impact of tailings pond spill

By Daybreak North, Daybreak Kamloops

CBC News

5 May 2015

A study on the impacts of a tailings pond spill at the Mount Polley mine last summer shows a number of changes to the Quesnel Lake ecosystem, but researchers say it's still too early to determine the long term impacts on fish and drinking water.

The report, authored by five researchers at the University of Northern British Columbia, documented the findings of samples taken in the two months immediately following the spill, between Aug 4 and Oct 4, 2014.

It found the levels of the lake rose 7.7 centimetres in that time, and the temperature at the bottom of the lake increased from 1 to 2.5 degrees Celsius.

It also found higher levels of sediment — associated with an increase in turbidity in the lake.

"That plume that we observed is distributing throughout the lake as a result of the natural swinging or rocking of the lake," Nikolaus Gantner, one of the report's authors, told Daybreak North's Russel Bowers.

While the report provides the hard data, it doesn't have answers about what the impact of that sediment will be on fish.

"It does provide a bit of context in terms of what happened from our perspective, but in terms of the final answers as to whether I'm going to be able to eat my fish — these are long term questions that aren't immediately answerable at this point," another co-author Sam Albers, who is the manager of Quesnel River Research Centre in Likely, B.C., told Daybreak Kamloops' Shelley Joyce.

"It's going to be the first in a long series of research papers."

Report on CBC News "The National" https://www.youtube.com/watch?v=hnPGpF3-n18&feature=youtu.be

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Quesnel Lake future still cloudy after Mount Polley mine disaster: report

The Canadian Press

5 May 2015

A lake in British Columbia likely survived a major pollution disaster when a tailings pond at the Mount Polley mine collapsed last summer, but it needs constant monitoring to track any long-term impacts, says a new report.

Researchers from the University of Northern British Columbia and the University of B.C. studied the massive sediment plume of waste and water within Quesnel Lake in the three months following the breach of the tailings pond at the open pit gold-and-copper mine.

UBC physicist Bernard Laval said Tuesday that mine tailings were likely flushed from the lake into the Quesnel River, but huge amounts sunk to the bottom and could leach over the years.

Twenty-four million cubic metres of silt and water spilled into area waterways last August, including Quesnel Lake, a major sockeye salmon habitat.

"My sense is Mount Polley got very lucky in that their tailings are relatively chemically inert," Laval said. "The concern is that metals will dissolve into the water and make their way into the food chain."

The study found elevated levels of copper concentrations in sediment samples and discovered a sediment plume at depths below 30 metres in the west arm of Quesnel Lake.

It also documented a lake level rise of almost eight centimetres and a temperature increase at the bottom of the lake of up to 2.5 degrees Celsius.

"The contaminant introduction, mobilization, and bioaccumulation may pose risks to 31 resident and anadromous fish stocks, which support recreational, commercial and First Nations 32 fisheries," the report said.

"The nature of waste materials now present in Quesnel Lake presents a potential hazard to the metal content of aquatic food webs and the growth, survival and behaviour of important fish species."

Laval said constant monitoring of the lake's water quality by governments and scientists would ensure potential impacts are immediately known.

"The lake has some resilience," he said. "We don't know how much. It could have been worse, and the chemistry could have been worse."

Environment Minister Mary Polak said the study matches current and consistent clean water tests conducted by the government, but years of testing are necessary.

She said elevated levels of metals have been found in the lake, but so far there are no signs that the mine waste is dissolving into the water. Polak said current testing indicates it's safe to eat the fish from Quesnel Lake.

"It confirms what we've already found, and all those results are posted monthly and will continue to be posted monthly," she said.

Alaska's Lt.-Gov. Byron Mallott is set to tour the Mount Polley mine site Wednesday to view the aftermath of the tailings-pond collapse and gain evidence of B.C.'s commitment to preventing a similar mining disaster.

Mallott was dispatched by Alaska Gov. Bill Walker to register U.S. concerns about a threat that any future mining catastrophe in B.C. could have on waters flowing into that state.

Vancouver-based Imperial Metals, which operates Mount Polley, said it could reopen the mine in June if granted a permit.

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Mount Polley mining disaster caused major changes to ecosystem — study

Cecilia Jamasmie

Mining.com

6 May 2015

Nine months after Canada’s Mount Polley copper and gold mine’s tailings pond breach, a new report has found a number of changes in the local ecosystem caused by the massive spill.

Researchers from the University of Northern British Columbia and the University of B.C., who studied the sediment plume of waste and water within Quesnel Lake in the three months following the incident, have concluded the water reservoir’s ecosystem has changed.

Among other anomalies, the report quotes a rise in the lake’s water level of 7.7 centimetres between Aug 4 and Oct 4, 2014, with the temperature at the bottom of the lake climbing from 1 to 2.5 degrees Celsius.

It also found higher levels of sediment — associated with an increase in turbidity in the lake.

Mine tailings were likely flushed from the lake into the Quesnel River, says the document, with huge amounts sinking to the bottom, which could leach over the years, the team said in a statement.

However, they believe it is still too early to determine long-term impacts on fish and drinking water.

Vancouver-based Imperial Metals, which operates Mount Polley, has said it could reopen the mine in June if granted a permit.

The company laid off 120 employees this week, according to The Williams Lake Tribune. The figure adds to the 36 who lost their jobs last November, and the 50 people dismissed in February.

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Canadian, American groups call on B.C. to end underwater storage of mine tailings
 
Mines minister says that is not going happen in the province, or likely anywhere in Canada
 
By Gordon Hoekstra

Vancouver Sun

28 April 2015
 
The Greens Creek underground gold mine in Alaska has filtered its tailings and dry stacked them for more than two decades, a method recommended by a B.C. government-appointed expert panel following its investigation into the Mount Polley tailings dam failure last summer.

Dozens of Canadian and American environmental groups, First Nations and businesses, as well as scientists and individuals, have called on the B.C. government to end the use of storing mine waste under water and behind earth-and-rock dams.

But Energy and Mines Minister Bill Bennett said that is not going to happen in British Columbia. “I don’t think that’s in the cards for B.C. — or any other province in Canada — to adopt a policy where all you can use to manage tailings is dry-stack tailings,” Bennett said in an interview.

The demand from the U.S. and Canadian groups — sent in a letter Tuesday to Bennett and B.C. Environment Minister Mary Polak — came as a result of Imperial Metals’ Mount Polley tailings dam failure last summer.

The dam collapse released millions of cubic metres of water and tailings — finely-ground rock waste containing potentially toxic metals — into the Quesnel Lake watershed in the B.C. Interior.

The groups say their demand is based on a recommendation from the B.C. government-appointed expert panel to move away from the conventional method of storing tailings underwater behind earth dams.

Tasked with investigating the Mount Polley failure, the panel suggested a method called dry stacking, where the water is pressed from the tailings, which are then compacted and stacked. The panel also suggested backfilling underground mines and using old mine pits to store waste.

The diverse group of 90 organizations and individuals that signed the letter to the provincial government includes the Ketchikan Indian Community, Southeast Alaska Fishermen’s Alliance, Patagonia founder Yvon Chouinard, federal Green party leader Elizabeth May, University of Washington fisheries biologist Daniel E. Schindler, author and University of B.C. anthropologist Wade Davis, the David Suzuki Foundation and the Sierra Club of B.C.

“Part of our frustration here is we haven’t seen a strong commitment to the Mount Polley panel recommendations yet. We only hear vague statements about best available technologies,” said Chris Zimmer, Alaskan campaign director for River Without Borders.

Bennett said the expert panel did not recommend dry stacking exclusively, and noted that sometimes using water storage makes sense, particularly if a mine needs every drop of water to run their operations.

Instead, he said the bottom line from the report for him is about reducing water storage of mine waste where you can, and reducing the risk of failure by increasing safety factors.

He noted that both the Association of Professional Engineers and Geoscientists and the Mining Association of Canada are examining how to increase safety, and the province expects to launch a review of its dam safety regulations this summer.

The regulation review is expected to take about a year, Bennett said.