Archive | Mining Environmental Accidents, Pollution, Tailing Dams and Abandoned Mines

Mt Polley: The Cost of Moving Forward – by Jack Caldwell (I Think – August 6, 2014)

Jack Caldwell, P.E. has a B.Sc. in Civil Engineering, an M.Sc. (Eng.) in Geotechnical Engineering and a post-graduate law degree. He has over 35 years engineering experience on mining, civil, geotechnical and site remediation projects. He has worked on numerous projects throughout southern Africa, Europe, Canada and the United States.

In one of the many article I read on the Mt Polley tailings failure was an estimate of what it will cost to get the mine going again. A figure of $50 million was quoted as the cost to pick up all the tailings and return them to the tailings facility. I imagine that figure is based on five million cubic meters of tailings at about $10 a cubic meter to pick up. Here is why I suspect the figure is grossly low.

In conventional civil or mining earthworks $10 a cubic meter would be generous. But the material to be picked up is still a near-fluid. It will slosh around in the truck and spill out through the opening in the truck bed. Also the bottom of the creek now covered with tailings is by no means uniform. It is probably rough and rugged and teaspoons will be required to pry the tailings out of every nook and cranny. So let us double the cost of picking up the tailings and taking them back to the facility.

While it will not be easy to pick up the tailings strewn along the creek, it may be impossible to get back the tailings in the lake. Do you dredge the lake? Of course you can dredge, but then you will pick up a lot of clean bottom sediment along with the tailing. Inevitably they will have to consider placing a subaqueous cover on top of the tailings in the lake. This was done off the coast of Los Angeles to cover PCB sediment on the ocean floor, so it could be done in BC. But at what cost? Say another $100 million.

Next the tailings facility breach has to be repaired so that the returned tailings will stay there. That means plugging the breach. I am not sure I would let a workman go near those steep slopes that subtend the failure zone. Continue Reading →

The Risky Rise of the [Mine Tailings] Dams – by Andrew Nikiforuk (The – August 7, 2014)

A massive mining wastewater spill in the interior of British Columbia highlights a new global trend: tailing dams that hold waste are not only getting bigger, but posing greater risks to watersheds and communities downstream.

Drawing upon recent industry reports and presentations made by engineers living in the province, it’s clear that the complexities of the industry have multiplied and with them, risks to water are escalating.

Increased global mining production of substances such as iron ore, gold, copper and nickel along with rising metal prices has tripled the value of the industry from $200 billion to $600 billion over the last decade.

But due to declining ore quality, the sheer volume of waste produced by the industry, which can contain substances such as arsenic, lead and cyanide, is increasing.

Every year, the industry digs and moves as much solid rock (several thousand million tonnes per year) as all earthen materials transported by natural geological processes, such as landslides and erosion.

Because of the challenge of peak metals and high global demand, the mining industry faces a number of somber risks, as reported by Andrew M. Robertson of Robertson GeoConsultants at a recent mining conference. Continue Reading →

Editorial: Mount Polley tailings spill – Imperial’s best not good enough – by John Cumming (Northern Miner – August 6, 2014)

The Northern Miner, first published in 1915, during the Cobalt Silver Rush, is considered Canada’s leading authority on the mining industry. Editor John Cumming MSc (Geol) is one of the country’s most well respected mining journalists.  [email protected]

The complete failure of the tailings dam at Imperial Metals’ Mount Polley copper–gold mine in Central B.C.’s Cariboo region on Aug. 4 is the most depressing thing to have happened in Canadian mining since the Bre-X Minerals debacle in 1997. It’s the worst tailings dam failure tied to a Canadian company since the Los Frailes disaster in Spain in 1998 (5 million cubic metres spilled) and the Omai spill in Guyana in 1995 (2.3 million cubic metres spilled).

It’s about as big a tailings dam failure as you can get: some 15 million cubic metres of tailings muck has so far flowed out of the mine’s tailings-impoundment area through a gaping hole in an obliterated eastern portion of a huge dam wall.

To see the jaw-dropping scale of the devastation, watch the full video of a helicopter survey of the affected area at, posted by the Cariboo Regional District authority. The video takes 37 minutes, because the affected area is so huge: the massive tailings facility itself, Polley Lake immediately to the east and the deeply messed-up Hazeltine Creek, which empties into the western reaches of the formerly pristine Quesnel Lake, where there are critical salmon-spawning grounds.

In the video, huge amounts of material is actively flowing out of the tailings facility in great, muddy torrents into Hazeltine Creek. Have you ever seen a waterfall of mine tailings? It’s here in this video, in the middle of Hazeltine Creek — a formerly 1-metre wide trickle of wending water that is now a scoured-out 45 metres wide. Continue Reading →

Mount Polley mine tailings spill: Imperial Metals could face $1M fine (CBC News British Columbia – August 06, 2014)

Company ordered to stop pollution immediately and provide environmental impact assessment

Bill Bennett, B.C’s minister of energy and mines, says Imperial Metals will have to acknowledge and pay for any mistakes that led to the massive breach earlier this week of the tailings pond at its mine in central B.C.

The breach of the tailings pond dam at the copper and gold mine near Likely, B.C., released 10 billion litres of water and 4.5 million cubic metres of metals-laden fine sand, contaminating several lakes, creeks and rivers in the Cariboo region on Monday.

Speaking at a news conference Wednesday afternoon, Bennett said a pollution abatement order had been issued to Mount Polley Mining Corp., owned by Imperial Metals. If the firm does not comply, it could face fines of up to $1 million.

“If the company has made some mistakes… they will have to bear the responsibility,” Bennett told reporters in Williams Lake. Continue Reading →

What you need to know about tailings ponds – by Adrian Lee (MACLEAN’S Magazine – August 6, 2014)

Understanding the tailings ponds breach at Mount Polley near Likely, B.C., which has emptied mine waste into waterways

On Monday, an Imperial Metals tailings pond in B.C. breached its embankment, spilling contaminated water and waste material into the surrounding waterways and spurring a state of emergency in the area. It’s raised the ire of First Nations groups, who say the company ignored a report that the growth of the pond was unsustainable.

It’s angered environmental groups, furious at the suggestion that water with arsenic and mercury was released into the lakes. But what exactly are tailings ponds? Does the industry have an alternative? We talked to Scott Dunbar, the head of the University of British Columbia’s school of mining engineering, to explain the issues at play and the institutional attitudes that need to change so this doesn’t happen again.

Q: So what is a tailings pond, and how does it work?

When you take the rock out of the ground, you grind it up to particles about the size of sand and silt, then you run it through what they call a concentration plant and it separates the minerals of interest from the waste. The waste becomes tailings, and it gets mixed up with water, and it’s pumped out into this pond. The purpose of this pond, with an embankment around it, is to retain the tailings and allow them to drain as much as possible. It’s basically sand-sized particles, but there’s an awful lot of it that’s produced relative to the minerals that generate all that cash. This waste that has to be dealt with. It’s mostly silicates. If the filtering is done well, which it usually is, there would be very few metallics. Continue Reading →

Tailings ponds for mining and oilsands waste: FAQs (CBC News – August 05, 2014)

What’s in them, what makes them risky and how they’re regulated

The breach of a tailings pond at the Mount Polley copper and gold mine in B.C. has released 10 billion litres of mining wastewater into local waterways in early August. Local residents have been banned from using the water from the Quesnel and Cariboo river systems.

Here are the answers to some questions you might have about tailings ponds.

What are tailings?

Tailings are the byproducts left over from mining and extracting resources, such as extracting bitumen from the oilsands or minerals such as copper or gold from ores. Tailings include:

  • Finely ground rock particles – ranging from sand-sized to silt-sized.
  • Chemicals used to extract the valuable mineral or oil.
  • Water.

Continue Reading →

Mount Polley Mine tailings water ‘very close’ to drinking quality, company says – by Rhiannon Coppin and Bal Brach (CBC British Columbia – August 5, 2014)

Imperial Metals president Brian Kynoch says he would drink water from tailings pond that leaked into rivers

Imperial Metals president Brian Kynoch says the company accepts full responsibility for the breach that caused a massive failure at the Mount Polley Mine in central B.C. on Monday and sent billions of litres of wastewater into river systems.

“I apologize for what happened,” Kynoch said at a news conference plagued with technical problems in Likely, B.C., on Tuesday afternoon. “If you asked me two weeks ago if this could have happened, I would have said it couldn’t.”

Wastewater and tailings sediment from Imperial Metals’s Mount Polley copper and gold mine near Likely has contaminated several lakes, creeks and rivers in the Cariboo region, causing officials to evacuate local campgrounds and enact a number of water-use and drinking water bans. Continue Reading →

Mt Polley Tailings Failure: Lies versus the Truth – by Jack Caldwell (I Think – August 6, 2014)

Jack Caldwell, P.E. has a B.Sc. in Civil Engineering, an M.Sc. (Eng.) in Geotechnical Engineering and a post-graduate law degree. He has over 35 years engineering experience on mining, civil, geotechnical and site remediation projects. He has worked on numerous projects throughout southern Africa, Europe, Canada and the United States.

Today we have read all we can find on the failure of the Mt Polley tailings facility. It is all distressing. And mostly misleading. Here are a few clear thoughts on the topic.

The videos show that the tailings and water are still pouring out of the failed facility. Problem number one is how do you stop this flow. I do not know how I would stop the flow and nobody seems concerned to stop the flow. But more tailings and contaminated water are escaping as we write. If it rains, even more will be washed out. Demand number one is an answer as to how continued tailings flow will be stopped.

I can accept that the water and all it nasty constituents will be diluted by the rivers and lakes into which the water is flowing. But what of the solids? They are in the river, on the banks, and now in the lake. Will it ever be possible to clean this up, or will these tailings have to be allowed to wash by rain into the lake to join the bottom sediments? Maybe we need to build an emergency dam up-river of the lake to catch the solids.

Imperial Metals is saying the area affected is small by comparison with the area of the tailings facility. This is true, but irrelevant. Until they stop outflow, the threat of all the tailings to the environment remains. Continue Reading →

Mt Polley Mine Tailings Failure – by Jack Caldwell (I Think – August 5, 2014)

Jack Caldwell, P.E. has a B.Sc. in Civil Engineering, an M.Sc. (Eng.) in Geotechnical Engineering and a post-graduate law degree. He has over 35 years engineering experience on mining, civil, geotechnical and site remediation projects. He has worked on numerous projects throughout southern Africa, Europe, Canada and the United States.

It is always a very sad day when a major tailings facility failure occurs. As one commenter noted to me: “Whatever the facts, the failure casts a poor light on the industry, and makes all of our jobs more difficult in the future.”

Today we write about the failure of the Mt Polley tailings facility right here in British Columbia. I write only on the basis of the information readily available on the web. I have no other source of knowledge of this facility.

My first impression is that this is in a direct line of failures from Bafokeng, through Merriespruit, to now. Nothing has changed, this failure looks just like the failed Bafokeng dam looked when I went out to see it the week after it failed way back in the earlier 1970s.

We still cannot agree if the cause of the Bafokeng failure was overtopping of the crest of the perimeter embankment by too much water in the dam, piping of water through a sandy layer in the embankment, or slope instability via sliding of soft foundation clays. Continue Reading →

Spilled waste water at Mount Polley mine had failed guidelines for human, aquatic health – by Gordon Hoekstra and Tara Carman (Vancouver Sun – August 5, 2014)

Possible contamination after tailings pond for Imperial Metals’ mine breached, sending millions of cubic meters of waste into waterways southeast of Quesnel

The millions of cubic metres of water that poured out of Mount Polley mine when the dam collapsed had failed provincial water quality guidelines for human and aquatic health in the past, according to the B.C. environment ministry.

Data sent to the ministry by Mount Polley as recently as Monday showed that selenium concentration exceeded drinking water guidelines by a factor of 2.8 times.

There have also been drinking water exceedances of sulphate over the last few years, according to information supplied to The Vancouver Sun by environment ministry spokesman Dave Crebo.

Aquatic water guidelines have also been exceeded in the past for nitrate, cadmium, copper and iron.

The release of 10 million cubic metres of water — enough to fill BC Place more than four times — is also potentially contaminated with toxic metals such as arsenic and mercury, a concern for hundreds of area residents’ water supply and important salmon habitat. Continue Reading →

B.C. mine had issues with rising waste water ahead of breach, consultant says (The Canadian Press/Globe and Mail – August 05, 2014)

The Globe and Mail is Canada’s national newspaper with the second largest broadsheet circulation in the country. It has enormous influence on Canada’s political and business elite.

Quesnel, B.C. — A tailings pond that breached Monday, releasing a slurry of contaminated water and mine waste into several central British Columbia waterways, had been growing at an unsustainable rate, an environmental consultant says.

Brian Olding, who operates Brian Olding and Associates Ltd., said Imperial Metals Corp. (TSX: III) had been working on fixing the problem with waste water from the mine. Olding said he was hired by the company as well as the Williams Lake and Soda Creek First Nations to review the company’s plans to treat and release water as part of the province’s effluent release permitting process.

“More water was coming in over the year than they could deal with,” Olding said. “They just kept building the walls up higher and higher every year and it got to the point where that was untenable.”

He said the firm was seeking a permit to treat and release some of the water to keep the size of the pond in check at its Mount Polley Mine, an open-pit gold and copper mine about 140 kilometres southeast of Quesnel.

The earthen dam at one end of the four-kilometre-long pond breached early Monday morning, sending a 45-metre-wide wall of water and mining debris into local creeks and lakes. Continue Reading →

Residents calling it an environmental disaster: tailings pond breach at Mount Polley Mine near Likely, BC – by Paula Baker, Marlisse Silver Sweeney and Justin McElroy (Global News – August 4, 2014)

Local residents are calling it an environmental disaster. A breach of the tailings pond on Mount Polley Mine sent five million cubic metres of toxic waste into Hazeltine Creek, Quesnel Lake and Polley Lake, with fears it could spread far and wide in the coming days.

Residents in the area, along with visitors to waterways near the Mount Polley Mine close to Likely, B.C., have been issued a complete water ban. Affecting close to 300 homes, it extends to the entire Quesnel and Cariboo River systems up to the Fraser River, including Quesnel Lake, Cariboo Creek, Hazeltine Creek and Polley Lake.

People in Quesnel are also being asked to avoid using water from the Quesnel River, and late in the day the Cariboo Regional District extended the water advisory right to the Fraser River – although they said that was a precautionary measure. Continue Reading →

Mainstream Media Ignorance About Mining – Especially Waste Disposal – by Marilyn Scales

Marilyn Scales - Canadian Mining JournalMarilyn Scales is a field editor for the Canadian Mining Journal, Canada’s first mining publication. She is one of Canada’s most senior mining commentators.

I’ve let the daily press get under my skin again. Newspapers and the CBC are telling the public that mining companies are going to destroy pristine Canadian lakes by turning them into dump sites for toxic mine waste. Why does the popular press still think that everything coming from a mine operation is “toxic”? Has no one outside the mining industry ever heard of sub-aqueous deposition?

There are 16 projects for which mining companies have applied to use lakes as tailings repositories, claim the environmentalists. The list includes the following 15:

– NORTHGATE MINERALS – Kemess North (Duncan Lake)
– SHERWOOD COPPER – Kutcho Creek (Andrea Creek)
– ADANAC MOLY – Ruby Creek (Ruby Creek)
– TASEKO MINES – Prosperity (Fish Lake)
– TERRANE METALS – Mount Milligan

Continue Reading →