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.  Plus how you clear the area to make a good foundation is not obvious.  So let us add another $50 million just to close the breached zone and make it possible to put returning tailings back where they came from.

I cannot believe the regulators will let them continue operating the current tailings facility for future ongoing mining produced tailings.  Its history is tainted.  Thus a new tailings facility will be required before mining can recommence.  I see no obvious areas big enough to repeat the current tailings facility.  But let us assume there is one.  A new facility cannot be a centerline embankment.  It will have to be a downstream earth and rockfill dam with filters and drains and bells & whistles.  I guess that adds another $100 million.

In practice, the public outcry over building yet another hydraulic fill dam like the one that has just failed, will perforce, force consideration of filter press tailings disposal.  That involved putting the tailings through a filter press in order to squeeze out the water.  The end product is then more or less a solid that may be stacked and not be susceptible to flow. I would guess filter pressing would add yet another $100 million to our list of costs to reopen the mine.

When the Padcal tailings facility in the Philippines failed it filled in a local water reservoir that produced electricity.  The reservoir can no longer produce electricity and the power authorities are suing the mine for the loss of power generating capacity.   No loss of power generating capacity is involved in this instance, but it is not unreasonable to imagine that tour operators, fishermen, water users, and others will sue for loss of use or diminished use of the waters affected by the failure.  Let us add $100 million in lawyers fees alone, net alone awards the courts may make.

Let us not forget the cost to investors of the loss of share value.

I have by now lost count of the number of $100 million items needed to reopen the mine and restore the environment.  But however you add it up, it will not be cheap and could be a billion dollars in a short time.

And these costs pertain only to Imperial Metals.  The cost to other mining aspirants of delayed projects, additional tailings facility features, and so on is, in a sense, incalculable.   As one private correspondent said to me today: “This sets mining in Canada back for at least ten years.”  Another private correspondent said: “Nobody will permit a new mine in BC for at least ten years.”

In South Africa after the failure of the Merriespruit tailings facility, the regulators demanded and nowdays get quarterly reports from registered professional engineers on the status of each and every tailings facility.  Replicating that in BC will add about $100,000to $500,000 at least to each BC mine’s annual operating budget.  The number grow so fast, my head spins.

We hope these are pessimistic conclusions.  But I am not sure what to do to turn them optimistic.  If you have ideas let us know.

Standard accident theory tells us that an accident occurs when many small incidents or omissions line up.  It is like a pile of Swiss cheese with hole in it: inevitably a pile of cheese with hole in it will result where holes line up and you could poke a knitting needle through the holes without penetrating the cheese.

This theory explains what happened at Mt Polley.  Many tiny acts and omissions lined up—and we see now the results.

It is human nature to try to simplify the explanation of bad events.  There was a witch; there was an evil spell; there was an incompetent designer; there was a cash-strapped company.  We seek the one party to blame–it is so much easier to do that than consider an unlikely chain of events leading to disaster.

The game of blame has started re the Mt Polley tailings disaster.  The designers of the facility, Knight Piesold are being mentioned in reports.  AMEC staff on site to raise the embankment are noted.  Imperial Metals is called out by a former employee.  The anti-government folk blame both the Provincial and Federal governments.  Harper is even excoriated.

And of course those First Nations folk who resisted release of water and the BC regulators who are still reviewing the application to discharge excess water are duly noted.

Some are asking if there are insurance companies on the hook and able to pay.  Many are wondering if this will become yet another taxpayer charge.

The most intelligent call I read today is the call for an independent board of experts who should be free of any constraints in assigning blame.   Let us speculate what they will conclude.

The embankments were designed to hold tailings not water.  The embankment was centerline construction–not a good design for a water retaining structure.   The perimeter embankment have a number of sharp corners.  Not a good thing as tailings and water pressure push the embankments away from each other and cracks develop and failure results.  There are distinct layers of different permeability in the embankments–piping through the more permeable layer could have caused the failure.  The old tailings foreman talks of a need to place five million tons of rock.  Were they thinking of a toe buttress to increase stability.

Rule one in tailings management is keep the water away from the perimeter embankments.  This simple rule was violated with impunity–or at most a warning from the regulators.

I am sure there are many other details that i do not know or cannot see in the videos I have examined.

Regardless the following is clear:

• It was a bad design
• It was variably constructed
• Water was held against the embankment
• It was raised without due consideration of the implication of overloading a poor structure
• None of the consultants or the inspecting regulators understood what was going on
• Imperial Metals obfuscated and delayed
• The First Nations people played a delaying game that proved fatal.

Thus we see a chain of poor decisions leading to the inevitable failure.  It is not correct to place the blame on one party only.  If only one party had acted with knowledge and responsibility, the dam would still be standing and I would be blogging about the most recent book I have read.

Of course all the parties are culpable and will soon enough be judged by loss of company, reputation, and a polluted living environment.

Of course Imperial Metals as the mining company must take the greater blame.  They did not act proactively.  There was no peer review of the tailings facility —a common enough practice these days.  They skimped on expenditure.  They kept pushing the limits.

I suspect the regulators had nobody in their employ trained and experienced enough to fully appreciate what was going on.  They discerned that too much water against the embankment was bad, but obviously had not enough experience or insight to think what could and did happen.

The consultants left the job or kept to a narrow scope presumably defined by the mining company.

So I believe that even an independent board of experts will be forced to find as I write above, with more detail of course.  It is inevitable they will find all in the chain at fault.  And they will conclude it is yet another example of the basic rule: sometimes ten small faults or omission line up and the result is disaster.

I wrote about this a while back–see this link for our paper that explores these ideas in detail.

The official statements are now beginning to appear re Mt Polley.  Here are two.  First from the Mining Association of Canada.

OTTAWA, Aug. 8, 2014 /CNW/ – On August 4, a tailings breach occurred at the Mount Polley mine in British Columbia, owned and operated by Imperial Metals. This incident is an unfortunate and significant issue that is being taken very seriously by the company, the Mining Association of Canada (MAC) and all stakeholders involved.

Imperial Metals has apologized to the public for the breach of its tailings pond. Imperial has recognized and publicly asserted its responsibility to remedy the situation, and is working to stop the problem, get to the root of why it happened, mitigate the effects and prevent future failures. The company is cooperating fully with communities, and local and provincial authorities. Fortunately, the incident did not result in injuries, and the tailings from the Mount Polley mine are non-acid generating, but the company does recognize there has been a significant environmental impact that will have to be addressed. Preliminary water tests released on August 7 show that the water remains within drinking-quality guidelines and that impact to aquatic life and fish is not expected. Further testing is being undertaken by the provincial government.

“The mining industry in Canada operates on the basis of public confidence in sound public policy, effective regulation and responsible management practices by companies. The confidence of the public in what we do and how we do it is essential. Incidents such as this are very rare, but it is the goal of MAC members that they never occur, and we have been working hard for many years to achieve this goal. Clearly, we still have work to do,” stated Pierre Gratton, MAC’s President and CEO.

Imperial Metals has been a member of MAC for the past two years and is in the early stages of implementing the Towards Sustainable Mining (TSM) initiative, a major component of which includes commitments to ensure the safe operation and management of tailings. In fact, one of the main drivers behind the development of TSM in the late 1990s was to prevent incidents such as this. Through MAC’s tailings guides, initially published in 1998 and considered the global standard for tailings management, and through TSM, the industry has made steady improvement in this area.

The last similar event occurred at a closed site in 1991 and did not have any off-site impact. Every day, there are more than 200 mines operating in Canada, and MAC members have invested great effort in building a track record of the safe management of tailings facilities over recent decades.  MAC and its members, through MAC’s Tailings Working Group, comprising many of the best professionals in this field, will review this incident to assess what can be learned and implemented to further ensure these incidents do not occur.

The second is from Knight Piesold:

VANCOUVER, Aug. 8, 2014 /CNW/ – The breach of the tailings storage facility at Mount Polley is an extremely unfortunate incident and Knight Piésold Ltd. shares the concerns with respect to the effects to local communities, First Nations and the environment.

Going forward there will be a comprehensive examination of this incident and there will be questions about the engineering and design of the tailings storage facility. As the former Engineer of Record of the tailings storage facility at Mount Polley, we feel it appropriate to provide some clarity and transparency of the role of Knight Piésold Ltd.

Knight Piésold Ltd. informed Imperial Metals that we would not continue as the Engineer of Record for the Mount Polley Mine on February 10, 2011, and subsequently ceased to perform that role. During the time we acted as Engineer of Record, the tailings storage facility at Mount Polley operated safely and as it was designed. A third party Review Panel provided independent review of the tailings impoundment design during initial construction and permitting during 1995 to 1997.  In 2006, while we were Engineer of Record, an Independent Third Party Dam Safety Review by AMEC Earth and Environmental confirmed that the three embankments were well-designed and well-constructed entities from a dam safety perspective.

Since February 10, 2011, Knight Piésold Ltd. has not had any responsibility or knowledge of any aspects of the design, modifications or performance monitoring of the tailings storage facility at Mount Polley.  The original engineering done by Knight Piésold Ltd. accommodated a significantly lower water volume than the tailings storage facility reportedly held at the time of the breach.  Significant engineering and design changes were made subsequent to our involvement, such that the tailings storage facility can no longer be considered a Knight Piésold Ltd. design.

Upon completing all assignments as the Engineer of Record in 2010, Knight Piésold Ltd. wrote to Mount Polley Mining Corporation and to the Government of British Columbia’s Chief Inspector of Mines and stated that “the embankments and the overall tailings impoundment are getting large and it is extremely important that they be monitored, constructed and operated properly to prevent problems in the future.”  A formal handover of design, construction and monitoring responsibilities was conducted on March 8, 2011when AMEC Earth and Environmental was acknowledged as the new Engineer of Record for all future work at the Mount Polley tailings storage facility.

Knight Piésold Ltd. is not familiar with, and therefore cannot comment on, the details of the incident, or on the design, construction, operations, water management practices or any other aspects of the Mount Polley tailings storage facility.

Lest you fall for the story that such failures are very rare, read my paper at this link where I write about the three tailings failures in 2012.  At the Tailings and Mine Waste conference in October I present a paper on the three tailings failures in 2013.  To date in 2014 we have had two tailings failures, Mt Polley and Duke Energy.  So maybe three a year is a standard?

The Vancouver Sun reports as follows about the Mt Polley tailings failure:

Likely resident Gerald MacBurney worked at Mount Polley for seven years, the last two he says as a foreman directing work on the tailings dam.

He says AMEC instructed the company to bring in five million tonnes of rock to shore up the outside of the dam in order to handle the increased amount of water in the tailings pond.

He said the company never carried through, perhaps only bringing in one million tonnes of rock.

That’s because they didn’t want to take their large equipment — big haul trucks that can carry as much as 120 to 200 tonnes — away from delivering ore to the mill, according to MacBurney.

Global BC reports MacBurney as saying:

“They needed to put in five million tonnes [of rock] around the dam, because they added, once they went to a bigger mine life, they added five times the amount of water,” adds MacBurney. “That dam was never designed to hold five times that amount of water.”

“Five million tonnes, well we got maybe a couple hundred thousand. And that’s it, in two years. I’d had enough.”

“They carried on going up instead of wider and doing the proper way of doing it,” says MacBurney.

 

Constructing a buttress of rock around the perimeter of a tailings facility embankment is not new or for that matter uncommon.  If the embankment slopes are steep and going higher than original planned, it is reasonable to construct a buttress around the toe of the dam. If water is seeping out of the impoundment and emerging as flow at the toe of the embankment, you first place a filter and then the mass of the buttress.

A decision to construct a filter and buttress at the toe of a tailings facility embankment is not taken lightly.  It is inevitably expensive to build.  But where there are valid concerns for the stability and integrity of the perimeter embankment, that is what is done.

If, as MacBurney says, a decision to stabilize the embankments was made, clearly somebody had concerns about the stability of the facility.  There must somewhere be a letter, report, or drawing showing what had to be done and explaining why it had to be done.  Such a document would surely have been provided to the regulators–for so significant a change from the original design would have required their concurrence.

And when timely construction of the buttress was not happening, surely somebody besides MacBurney, must have been concerned.  One would have expected the regulators to at the least have written to the company urging completion of the stabilization works.

I am not convinced that a buttress would have prevented the failure.   I suspect the upstream circular arc failure zone that is so apparent in the videos I have seen indicates high pore water pressures in the upstream part of the embankment–high enough pressures to have cause the failure.  Such a failure would not have been precluded by a buttress.

But if the two embankment that came together at the corner where failure occurred were moving apart, then the buttress may have indeed limited the movement.  Here is a picture of a recent failure in Hungary where the two perpendicular embankment both moved outwards and away from each other.  Maybe this is part of the Mt Polley story.

This mystery of the missing buttress could easily be cleared up if we had ready access to the reports.  Or if all such document were made public.

So the legal trials and travails begin.  Here is the first announcement:

LONDON, Ontario–(BUSINESS WIRE)–Siskinds LLP today announced the commencement of an investor class action against Imperial Metals Corporation (“Imperial”) (TSX:III) and certain of its directors, officers and related parties. The action relates to the circumstances surrounding the failure of the tailings facilities at Imperial’s Mount Polley gold and copper mine near Likely, British Columbia on August 4, 2014.  The action is brought to recover losses suffered by persons who acquired common shares or notes of Imperial between August 15, 2011 and August 4, 2014.

Siskinds website is at this link.  Appears they specialize in class action law suites, and to judge they are often successful.  Here is how they describe themselves:

The Siskinds class action team is comprised of a group of seasoned and talented litigators with a substantial record of success for their clients, both plaintiffs and defendants.  Siskinds has acted as counsel in more than 100 class actions. These include class actions involving breast implants, vanishing premium insurance products, price fixing conspiracies, defective drugs, employment and pension claims, environmental actions, and securities litigation.

If share prices for Imperial Metals have fallen forty or more percent, and they could fall more as the implications of the failure become more stark, then there certainly was a lot of money lost by investors.

Siskinds is casting the net wide.  They are intending to sue directors, officers, and related parties.  Could they sue the provincial regulators?  Certainly they will include the engineering companies involved.

Will they have to prove negligence or merely involvement?   Do they have to prove that the actions of one or more of the parties involved were the cause of the failure?  Or is it enough to establish loss of share value?

Thus we have another item to add to the list of the cost of “cleanup.”

Here are the stories of the seven dam failures that have occurred since the beginning of 2012. Six are failures of tailings facilities. The seventh is a rockfill dam. The following are extracts from technical papers that I wrote well before the Mt Polley failure. Details of the first three are available at this link. Details of the remaining four are in a paper that I will present at the Tailings and Mine Waste 2014 conference in Colorado in October of this year.

There is no common thread, except possibly a failure by those responsible to understand the beast, the Wicked Stepmother, they were dealing with.  If you see other common threads, then please comment.

GULLBRIDGE MINE, NEWFOUNDLAND, CANADA

The old Gullbridge mine tailings facility in Newfoundland is the responsibility of local government. Observations indicate potential problems. A respected consulting firm, Stantec, issues a report on the safety of the facility and concludes they cannot tell what is going on because of poor construction records, copious vegetation, and a lack of geotechnical data. They recommend a full investigation. But the local authorities delay, preferring to spend money on inexpensive reports in preference to expensive physical action, do nothing. The dam fails and tailings spill into the downgradient wetland. Now they are fixing the failure.

The Newfoundland and Labrador Department of Environment and Conservation (2012) reported:

At 7:45 am on Monday December 17, the tailings dam at the former Gullbridge copper mine, central Newfoundland failed while work was under way to stabilize it. The failure resulted in a breach of the 7 m high dam approximately 25 m wide. The dam was impounding mine tailings that were partially covered by water forming a tailings pond. As a result of the failure, the pond drained completely over the next few hours, and a small amount of the tailings escaped. Small quantities of tailings pond water continue to flow from the breach.

Gullbridge is a typical example of local authorities taking over a tailings facility without making the mine close it or even document how it was built. The local authorities appear not to have had the capacity to manage the facility. They engaged reputable consultants but failed to act on their advice, and appear to have stalled in order to minimize expenditure.

HB MINE, SALMO, BRITISH COLUMBIA, CANADA

The mine closes and very intelligently gets the local authorities to take over the site as a landfill. It appears the landfill folk in the local authorities engineering group did not understand tailings. Environmental groups warn of the dangers, but nobody hears them. It rains a lot, and piping and leaks are observed. In July 2012, the earth dam sloughs; a sinkhole develops; tailings move out into the environment; it will now cost almost a million dollar to fix; and the taxpayer pays.

A little more detail:

Residents who could be affected by a structural failure impacting the highway and properties below the site have been notified by the RCMP. Currently flaggers are positioned on the highway as a precautionary measure.

Geotechnical engineers have installed three pumps to decrease the level in the tailings pond as a first step. Additional larger diameter pumps and siphoning hoses are en route to continue to reduce water levels. An outlet channel is also being deepened. Several excavators are on site and will work at in-filling areas of seepage when they are able to be deployed safely.

Environmental monitoring and reporting is ongoing and 24 hour security has been implemented at the site. The weather forecast is favorable – with little or no precipitation forecast – and geo-technicians and engineers on site indicate the area is gradually getting drier. This should permit additional remediation planning and on-site work to proceed over the next few days.

The fact is it is expensive to maintain so-called closed tailings facilities. It takes expertise and experience to look after closed tailings facilities. And even the best consultants are cowed by clients who do not want to spend money, regardless of how dire the situation

CASA BERADI MINE, QUEBEC, CANADA

A news report describes the failure in these words:

During a routine evening inspection of the tailing ponds on Wednesday, May 1, 2013, at the Casa Berardi Mine, located approximately 95 kilometres north of the town of La Sarre, in the Abitibi region of northwestern Quebec, it was discovered that there was a breach of an internal tailings dyke which resulted in a surge of liquids and suspended solids over the external tailings dyke. A majority of the material was contained inside the tailings pond containment area and no further discharges into the environment have occurred. The Casa Berardi Mine has four tailings containment ponds and the material flowed from one tailings pond into another tailings pond, neither of which are in use for current operations.

From the little available on the web, it appears the mine was in transition at the time of failure. Hecla had recently bought the property from its previous owners and had not fully taken charge. It is just possible that in the inter-regnum those leaving the mine had not fully passed off operation to those taking over the mine, and this event occurred in the absence of committed oversight.

.

PHILEX MINE, PHILLIPINES

A tailings pond in the Philippines at Philex Mining Corporation’s Padcal gold mine is discovered to be leaking on August 1, 2012. Philex suspends its operations in order to investigate the source of the leak. The company deploys cleanup crews to remove chemicals and sediments discharging into the river nearby. The tailings failure was said to have been caused by heavy rains. However, I believe the spill resulted from failure of the penstock.

The mine is owned by a Hong Kong mining company and they have done a superb job of controlling the flow of information about what happened. The authorities have fussed and fumed, but to no avail. It seems the penstock is now plugged and mining and tailings disposal continues apace.

This failure also proves that the size and public pronouncements of the mining company are vain hot-air when it comes to the tailings facility. The penstocks had leaked for weeks before the main event; yet nobody did anything. And prior to the event, the government was supine. After the event, the government is grousing, suing, and making noise.

OBED MOUNTAIN COAL MINE, ALBERTA

News reports describe the failure thus:

On October 31, an impoundment holding a slurry of waste from Sherritt International’s Obed Mountain coal mine failed releasing approximately 670 million litres of waste into the Athabasca River watershed. Alberta government press releases referred to the waste as “process water”, “suspended solids, which include such things as clay and organic matter”, and sediments containing “such things as clay, mud, shale and coal particles”. Official statements have provided very little information about the extent or magnitude of the spill, and a November 4 statement stated the spill was somehow “contained”. As reported in the Edmonton Journal, the only thing that was contained was the waste remaining at the mine site. The plume released to the river ex-tended 113 km by November 8.

It appears that operations at the mine had been suspended last year, due to what is believed to be overwhelming economic and market pressures. Reclamation was in progress at the time of failure.

One report states “nobody knows when the facility was last inspected.”

Maybe they were just too busy with closure to notice facilities that were open. Once again this failure appears to have occurred at a time when there was a change of staff and operating procedures at the mine. May we conclude that when such changes are in progress, failure probabilities increase?

DUKE ENERGY, NORTH CAROLINA, USA

The first I read of this failure on Feb. 2, 2014 was a report that started:

Duke Energy said Monday that 50,000 to 82,000 tons of coal ash and up to 27 million gallons of water were released from a pond at its retired power plant in Eden into the Dan River, North Carolina and were still flowing.   Duke said a 48-inch stormwater pipe beneath the unlined ash pond broke Sunday afternoon. Water and ash from the 27-acre pond drained into the pipe.

A second report indicates that they knew of the broken pipe.

Duke initially estimated up to 82,000 tons of ash spilled from two ponds at a coal-fired plant in Eden that the utility closed two years ago after a stormwater pipe that ran under the ponds ruptured.

I liked this statement most:

Duke spokeswoman Paige Sheehan said the utility has hundreds of people working to repair the leak, and the flow of ash into the river has been slowed to a trickle – and shut off completely at times.

And despaired at this statement;

It’s not clear why the reinforced concrete pipeline broke. Built in the 1960s, it runs beneath the unlined ash pond – the only one of Duke’s 14 North Carolina ash ponds with such a pipe beneath it. A power plant in Indiana also has a pipe under its ash pond.

In fact it appears that there was also a 36-inch diameter pipe beneath the pond. I could not establish if it too failed.

Clearly there should not be pipes, in particular old ones, beneath tailings facilities. I believe this is true of stormwater pipes and penstock pipes. Also we may conclude that when politicians intervene to protect companies from regulators, failure will occur sooner or later,

A recent report on cleanup reads:

The biggest ash deposit yet found in the Dan, following a Feb. 2, 2014 spill 25 miles upriver at Duke Energy’s Dan River power plant, lies on the bottom just above Danville’s water in-take. The ash covers an area about 300 yards long and 25 yards wide. It is up to 1 foot deep. Its removal from the river will be far harder than its release into it from a broken metal pipe. Duke’s contractor will use a dredge that vacuums ash off the river bottom while disturbing sediment as little as possible. About 2,500 tons of ash and sediment will be sucked up by the end of June — a small fraction of the up to 39,000 tons that spilled.

TOKWE MUKOSI, ZIMBABWE, AFRICA

Although not a tailings facility, the story of the Tokwe Mukosi dam hold lessons for the tailings industry. Zimbabwe is a dry land. Water is precious. Yet land is valuable for the subsistence farmers. Decades ago the authorities decided to build a dam in southern Zimbabwe to provide more water for agriculture.

Coyne and Bellier, a famous French dam design and construction company recommended a concrete arch dam. The Zimbabwean Department of Water Development said this would be too expensive. They decided to use their own design: a rockfill dam with an upstream concrete facing.

As is so often the case in Africa, construction started, was delayed, was undertaken intermittently, and funding was sporadic and/or diverted. An Italian company was brought in to do construction. Nobody living in the zone of future dam inundation was moved.

The rockfill embankment was planned to rise to 89-m high and impound 1.8 billion liters of water.

Placement of the rockfill proceeded over a decade or so. Then last year it rained. Reportedly the rainfall was about twice the annual average, although nobody seems to know for sure. The water started to flood the reservoir. People moved away fast. Heavy flooding in February 2014 caused a failure on 4 February, 2014.

Because the upstream concrete facing was not in place, water seeped and ultimately flowed through the rockfill. The authorities assured everyone: “The dam is sound; it is not failing; it is only water squeezing through the rocks.” Although wiser council prevailed and those living downstream of the dam were evacuated. This in spite of the following assurances by Engineer Mairukira, who said:

• The dam wall is premised on similar ones in other countries
• The structure is strong and will never collapse
• The dam wall is structurally safe
• We are using the latest technology to build it.

Pictures show a significant slumping of the rockfill of the front face of the dam. It still amazes me that the dam did not slump and fail completely. The Italian contractors continued to build up the crest of the embankment to keep ahead of the rising waters. Their courage, or folly, is astounding.

I have lost count of the number of radio stations, newspapers, and magazines that have contacted me asking for opinions on the Mt Polley tailings happenings.  Somehow the email from Adrian Lee of that most reputable of Canadian magazine, McLeans, had a air of intelligence the pulled me into replying.  (I confess to being a regular reader of McLeans.)

We talked and email over a few days.  I was impressed by his intellect: the questions he asked, the way he listened, and his response comments.  I opened up.  You can decide if this was wise or not—for below I make free to copy his article which includes some of the things he writes about some of the things I said.  This is good writing and good journalism.

Before you read, may I also note the many and insightful comments on my previous postings on Mt Polley.  They prove at least the following:

• I succeed as a blogger in being controversial
• I am often wrong as the more prudent heads of those commenting establish
• There are some pretty wise and experienced people out there (if only we could get them involved, all would be well.)

So when reading my postings, please also read the comments.  I do; I enjoy them; I learn from them; and often change my mind on the basis of what they say—although as a matter of policy I never indulge in debate with my commenters.

So then, from McLeans at this link:

Uprooted trees, muddied water with a silvery sheen, fish belly-up on the surface. There was something essentially un-Canadian about the first galling photos to emerge out of Mount Polley, B.C., where a copper and gold mine’s tailings pond—a containment area where the waste produced through the mining process is treated and allowed to dry before being disposed—burst through its earthen walls last week. All told, 10 million cubic metres of water contaminated with arsenic and mercury and 4.5 million cubic metres of tiny silt silicates spilled into Hazeltine Creek and Quesnel Lake. All this, too, right before the beginning of what the Department of Fisheries has suggested might be the largest salmon run since it started keeping records in 1913: As many as 72 million sockeye, it says, could wind north through the Fraser River in the coming month.

So it’s little wonder that anger and disappointment have been the primary emotions. “Hazeltine Creek will never again be what it was. It’s outrageous, it’s awful, it’s catastrophic,” said Al Richmond, chairman of the Cariboo Regional District, where the leak occurred. “It’s devastating, and there’s a great deal of uncertainty and mistrust.”

The recovery, so far, has gone as expected. Imperial Metals, which owns the mine and its tailings pond, has claimed responsibility, paying for the potable water being shipped in. After an initial water ban and state of emergency, a B.C. report that found the water to be safe to drink resulted in a partial rescinding of the ban. In the ensuing days, a salmon expert told Maclean’s that the sockeye salmon run will not be affected by the leak because of how quickly the chemicals are diluting through the rapidly flowing water, and it turned out that the tailings were non-acidic—all good news in a bad-news climate.

But the question of what comes next may be a far trickier proposition for what has been the largest such leak in Canadian history. What Imperial Metals will undertake is a long, arduous cleanup, the precise details of which have yet to be determined. It will take decades before it’s clear if it was successful—and, according to one expert, recent leaks in the United States have largely been handled by simply leaving the water and its tailings alone.

Tailings-pond leaks are rare, but they do happen: On average, three leaks occur every year worldwide. In B.C. alone, there are about 130 mines, each with at least one tailings pond, the default way of storing and disposing of mine waste “since the beginning of time,” said Scott Dunbar, the head of the University of British Columbia’s mining engineering program. “It’s a fact of life.” Reports say Canada’s previous case came last October, when a tailings pond that was in the reclamation process leaked at the Obed Mountain mine in Alberta, loosing 670,000 cubic metres of coal tailings into the Athabasca River.

That relative shortage of leaks means no one company specializes in their cleanup, and the fact that every region and leak is different means that a great deal of consulting needs to occur first, says Jack Caldwell, a mining and civil geotechnical consultant for B.C.’s Robertson GeoConsultants firm, who has been involved in “umpteen” tailings-pond designs and repairs over his four-decade career. First, Caldwell says, the breach must be closed. “Tailings are still flying out, and if it were to rain, more tailings would come out,” he said. Imperial has said this fix will be finished in three weeks’ time.

Then, the downstream tailings still floating on the surface of the water need to be picked up by one of three methods: a combination of front-end loader and trucks, a slurry pump, or using a water pump to blast the water and tailings toward another downstream embankment. Finally, the trickiest part of the process, is an effort so complex that one person involved in the industry posted on Caldwell’s mining blog that it’s like “putting smoke back into a cigar”—retrieving the tailings that are already at the bottom of the lake.

One option is dredging the lake, but Caldwell says that would actually loosen up all the tailings again, contaminating the water once more. “You’re probably going to cause more damage than benefit by doing that,” he said.

That means that the best course of action might actually be to leave the tailings in the lakebed, with the expectation that vegetation will grow over it. Caldwell, himself a proponent of this plan, says that’s what was done to handle decades’ worth of chemical runoff on the Palos Verdes shelf near Los Angeles and, in part, in Tennessee, where the Kingston Fossil Plant leaked more than four million cubic metres of coal ash in 2008, the largest such spill in America. After all, he says, “you’re never going to get everything clean.”

But if effectively doing nothing becomes the plan—Imperial has been given until Friday to file a report—it will further accentuate the perception of negligence on the part of Imperial by environmental groups. The damage—and it was devastating, especially at its epicentre—is also making it hard to move beyond the images to get to the facts and realities of the cleanup. “This is one of those horrible situations where you’re damned if you do, damned if you don’t,” says Caldwell. “I suppose, in this democracy, you’re just going to have to have a discussion to decide which is the lesser of the two evils.”

No one has denied that the spill is anything short of terrible, but, in the wake of the incident have come “crazy assertions” about the extent of the environmental impact before any reports have emerged, says Carl Walters, a professor emeritus at the University of British Columbia who has been studying sockeye salmon in the area for the last 40 years. He says he’s heard claims that the salmon would be confused by the scent of the contamination (they use scent, but only with organic compounds) and that for some of the claims about the spill’s effect on the lake to be true, “some of the water would have to flow uphill,” he says with a laugh. Walters expects that the contamination of the water—already somewhat low—will be carried out of the system within a month. “Unless they have another breach, it’s not really a big deal,” he said. “Anytime anything happens, the eco-babble comes out and, mostly, it sounds like science and, mostly, it has no scientific basis.”

That matter of knee-jerk environmental judgment—such as the David Suzuki Foundation’s recent call for a freeze on new permits for B.C. mines until every tailings pond is reviewed—also threatens to mask real issues. Take Jason McNamee, for instance: He’s a B.C. conservationist and a scientific adviser to the World Aquarium and Conservation for the Oceans Foundation, making him an unlikely dissident in the narrative that the Mount Polley leak is an unmitigated catastrophe.“The Mount Polley mine disaster is unacceptable,” he said, “but using the word disaster? Ah, I don’t know if that’s the correct terminology. It’s all about perspective; if we don’t take a longer-term perspective, how do we expect to make change?” He notes that volcanoes spew out ash that contains sulfuric acid and arsenic in “several orders of magnitudes more” than the Mount Polley spill did; the city of Victoria, too, unleashes around 130 million litres of untreated sewage every day into the Juan de Fuca Strait. “Some environmental groups like to rage at the system, but that doesn’t help. We need to be looking at solutions, and back that up with voting and other mechanisms of having your voice heard,” he said. “The miners are doing what miners do. They’re providing a necessary resource and making a profit. They’re not bad guys, and we don’t need to paint them as such.”

The long view is the wise one, especially since it will take a long time to assess the environmental impact. Caldwell says the cause of a tailings-pond failure in Bafokeng, South Africa, in 1972 is still something of a mystery, with the environment only finally recovering. And then, of course, there is cost. According to a Reuters report, analysts estimate that the cost of the cleanup could range from $50 million to $500 million, with BMO suggesting it will be in the $200-million range; over the weekend, Imperial Metals vice-president of corporate affairs, Steve Robertson, said any cost estimate at this point would be a mere guess. But Caldwell envisions the cost for the breach repairs and a likely facility replacement alone will be at least $200 million, a number that doesn’t even include legal costs and that tricky cleanup process; the 2008 Tennessee leak has recently exceeded one billion dollars in recovery costs. There are also questions about whether Imperial can endure that kind of financial hit without having to sell off assets, despite its commitment to cleaning up the spill: Mount Polley accounted for most of the company’s copper, gold and silver production in the second quarter.

In a situation where a decisive response is demanded by the local community, doing nothing, as some experts suggest, may yet be the best option. For the company, that presents a real risk. “Respect is earned, not given,” said Richmond, the Cariboo regional chairman. “It’s in Imperial Metals’ ballpark now.”

We are heartened by today’s announcements re the Mt Polley tailings facility failure.   I particular we applaud the choice of experts retained to do the engineering review.

CBC New reports as follows on this issue:

Minister of Energy and Mines Bill Bennett says the B.C. government is setting up two separate reviews following the Mount Polley tailings pond failure earlier this month.

Bennett said Monday that:

• The first review by three independent experts will investigate the failure of the tailings dam at the Mount Polley mine.
• The second review will require all mines in British Columbia that have tailings dams to have independent experts conduct a review of their facilities and submit them to the government.

The first review will be completed and submitted to the government and the Soda Creek and Williams Lake Indian bands by Jan. 31, 2015, and the recommendations will be implemented by the government “where needed,” Bennett promised.

The minister said the reviews were necessary to restore public confidence in the mining industry.

“We have a responsibility, as the jurisdiction where this failure took place, to find out exactly why it happened, ensure it never happens again and take a leadership role internationally in learning from this serious incident,” Bennett said.

When asked what might have caused the dam to fail on Aug. 4, Bennett said there is no “leading theory” yet.
The three experts appointed to review the dam failure are:

• Norbert Morgenstern, an adviser to consulting engineers.
• Steven Vick, a geotechnical engineer from Colorado.
• Dirk Van Zyl, a professor at the University of British Columbia’s Normal B. Keevil Institute of Mining Engineering.

Zyl called the the failure of the tailings facility at Mount Polley ” a dark day for the mining industry not only here in British Columbia, but worldwide.”

“It’s extremely important for us to understand how this breach happened and why so that we can move forward with the best possible practices in ongoing and future mining operations,” he said.

I do not believe a better panel could be found.  Morgenstern is the leading Canadian expert on tailings dams.  I first came across his name at university in the 1960s when we studied his theories for foundation design.  I have made presentations to him in his capacity as a peer reviewer to Suncor on their tailings facilities.  I have read many of his reports and listened to many of his lectures. He is old but still wise and sharp.  He is an expert of repute..

Steve Vick I first met in the early 1980s when we were working on tailings facilities in Colorado.  On an old posting on this blog I wrote this about Steve: Steven Vick’s great book is Degrees of Belief, Subjective Probability and Engineering Judgment.  This is the book that started and still underpins any enquiry into the nature of tailings facilities and their management via an understanding of the role of probability, judgment, and ultimately decision making in the mining context.   And of course there is his book Planning, Design, and Analysis of Tailings Dams.  I have read it again and again over the years for it is full of wisdom.  Read his paper at this link to see how thorough he is.

Writing in 2012 about Steven Vick, I said the following:

Risk is the product of probability and consequence.  In the long term, as time proceeds to infinity, the probability of an adverse event tends to one.  When seeking to control the risk of long-term tailings facility failure, there is little we can do about the probability of failure.  In the goodness of time it will occur.  All we can do today, is to seek to limit the consequences of failure, adverse performance, and unacceptable impact.

Steve Vick reminded us of this inescapable conclusion in a magnificent keynote address at the Tailings & Mine Waste 2012 conference just ended in Keystone, Colorado.   The authority and reputation of Steve, who is surely the doyen of tailings, ensures that his insight will force a change in the way we think about and act as tailings engineers.

Steve reminded us that the consequences of failure of a tailings facility go well beyond the physical impact of tailings that may escape the failed facility and impact the receiving environment.  The consequences may include significant and even total loss of shareholder value, the closure of the mine, the shutting down of the company, and huge financial expense to society.  And of course, there is loss of life, loss of reputation, and loss of industry credibility.

What can we do to minimize the consequences of failure of tailings facilities?  The best is to undertake filter-pressed, dry-stacking.  In the long term, things may move, but not flow—the worst consequence of failure.  Put the tailings in a place where the inevitable migration of material and constituents is to an accepting environment.  Avoid downstream rivers, lakes, and oceans.

Steve noted that in all cases the tailings facility will eventually become the ward of the state (society).   Only in the case of the UMTRA Program is there a supposedly perpetual government agency charged with looking after the closed tailings facilities: twenty-four old uranium mill tailings piles.

Steve noted that only European cathedrals have cultural value sufficient to induce society to care for them in the long term.  Closed tailings facilities will never be such icons of cultural respect.  Of course we can turn the closed impoundment into a riding stable as was done at the Cannon Mine.  But not all closed tailings facilities lend themselves to such conversion into socially beneficial places.

The inevitable conclusion from hearing Steve is that some mines just should never open.  Some tailings practices are going to have to go the way of the dodo.  His best example is a water cover.  And maybe hydraulic fill in places where the tailings will not be totally dry or frozen forever.

Maybe we should get Steve to head up an international evaluation of how to undertake tailings practices that result in long-term, tolerable consequences.  I suspect that if he or others do not do this, we will see no change in the rate of tailings facility failure and long-term negative consequences for too many places.  Why we may see the demise of  mining and society as we know and enjoy it.

I will credit anything he concludes.

Dirk Van Zyl is a long-time colleague and friend.  I took his job many years ago when he left SRK to come to the USA to do his doctoral thesis.  We are still working together on organizing conferences for InfoMine.  Dirk is quoted in one report as follows:

UBC Engineering Prof Dirk van Zyl says failures like this are about one in a million per year.

“…you always hope it never happens at home and  this time it did and so it’s a great force that’s released when you have such a failure

van Zyl says large failures like this and investigations of them often find there could be a number of ways the breach could have happened.

Actually his statistics are off by a thousand or two.  Franco Oboni of Riskope writes the following in a comment on a previous posting on this blog:

On a portfolio of approximately 3,500 tailings dams world-wide we evaluated that in the decade around 1979 (1974-1984) the rate of failure was 10-3 (one dam in one thousand per annum on average) and the decade around 1999 (1994-2004) the rate of failure was 2*10-4 (two dams in ten thousand per annum on average). Those numbers mean respectively 3.5 major dams breach in average per year (1974-1984), 0.7 major dams breach in average per year (1994-2004). With those averages one could easily evaluate the probability of having more failures in one year, but we will leave this aside, for the moment. Again, we do not know if 3,500 is still correct, but we assume it is for the sake of the discussion, and there is no clear definition of what a major breach is, so we assume these are the most widely reported failures, that reach even non expert public through media exposure. The validity of the 3.5-0.7 range can easily be “verified” by looking at the Chronology of major tailings dam failures as published, for example, by Wise-Uranium in their website. As such, the decrease from 3.5 to 0.7 can be seen as an indicator of the mining industry performing overall a better job today than it did in the past, but we will also leave this discussion to another time.

Many hazardous industries (chemical, electrical, for example) around the world consider the limit of credibility for an accident at a probability in the range of 10-5 to 10-6 (one in hundred thousand to one in a million). By the way, hydro dams have historic record of failure floating around the credibility threshold. Thus tailings dams are to be considered more hazardous than hydro dams, and they unfortunately cannot be breached at the end of service life: they have to stay there “forever”. Obviously, with the estimated values of the prior paragraph, major tailings dams breaches are to be considered way above credibility now, and more so, in the longer run, although long term consolidation may help a bit.

No matter.  Mt Polley simply confirms that there are two to three tailings failures per year.  We had Duke Energy earlier this year and probably one more to go before Christmas.  Well before the panel presents its findings.

The only misgiving I have is that these three gentlemen are extremely busy without the added burden of this panel work.  Where will they find time to do it all?  I suppose the answer is the old adage: if you want good work done, ask only those too busy to do it.

So we wish them speed and success at finding out why Mt Polley’s tailings facility breached.

The five pictures in this posting, were taken (by me) at the Getty Center in Los Angeles.  This place is surely a testament to genius and attention to detail.

Yesterday I was asked if Canadian guidelines are adequate to deal with the Mt Polley situation. More specifically, the questions continued: if the current Canadian guidelines regarding tailings dam safety had been implemented, would the failure have been avoided. Before I answer these questions, let us first take a look at the guidelines that are out there.

APEGBC, the Association of Professional Engineers and Geologists, of British Columbia on their website say this:

APEGBC recently published professional practice guidelines for dam safety reviews: the Professional Practice Guidelines – Legislated Dam Safety Reviews in BC, which were commissioned by the BC Ministry of Forests, Lands and Natural Resource Operations. The Guidelines define the professional services, standard of care and specific tasks to be provided by APEGBC members conducting this type of work; provide descriptions of the roles and responsibilities of the various participants/stakeholders involved in a dam safety review; and set out expectations for the appropriate knowledge, skill sets and experience to be held by APEGBC members working in this field. The Guidelines also aim to address consistency in the reporting prepared by APEGBC members providing professional services in the field of dam safety reviews.

The Mining Association of Canada has published two guidelines for tailings facilities. These are described well at this link in the following terms:

In 1998 the Mining Association of Canada (MAC) published A Guide to the Management of Tailings Facilities. This guide was prepared by the Canadian mining community and is designed to assist mine operators in developing a successful management system for their tailings facilities. It covers each stage of tailings management from design through construction, operation and then closure and reinforces the integrated nature of each element. Its purpose is to provide information on safe and environmentally responsible management of tailings facilities, to help mine operators develop tailings management systems that include environmental and safety criteria, and to improve the consistency of application of sound engineering and management principles to tailings facilities.

MAC published a follow up manual in 2003 entitled, Developing an Operation, Maintenance and Surveillance Manual for Tailings and Water Management Facilities. This manual was developed to compliment the 1998 guide with a view to focusing on the day to day operations of a tailings facility. The need for this manual became apparent in 2000 when mining companies were demonstrating a significant progress in adopting and implementing tailings management systems. The manual draws on sound industrial practice and procedures and was prepared by tailings experts within the Canadian mining community.

In 1999 the Canadian Dam Association (CDA) revised its Dam Safety Guidelines to include tailings dams. MAC and other contributors helped to develop and incorporate tailings facilities into CDA’s guidelines meaning they now have the same level of respect as conventional dams. Martin et al. (2002) report that the revised guidelines focus on the responsibility for dam safety, scope and frequency of dam safety reviews, the need for an operating manual and emergency planning.

The MAC guide and manual and the CDA guidelines are intended to complement government regulations and promote due diligence of a mineral operator. The overall goal is to protect the environment and the public from the hazards associated with tailings storage.

The MAC guide and manual and the CDA guidelines are intended to complement government regulations and promote due diligence of a mineral operator. The overall goal is to protect the environment and the public from the hazards associated with tailings storage.

Then there are documents on the same subject from the Canadian Dam Association. Their website notes as follows:

 CDA has developed Dam Safety Guidelines and related technical bulletins that have become primary  references for dam owners, operators and regulators. The CDA Mining Dams committee has developed  additional guidance on dam safety for tailing dams and other mining dams, following a three-year period  of input, review and comment. The new publication – Technical Bulletin, Application of Dam Safety  Guidelines to Mining Dams – addresses technical aspects of mining dam safety. This Bulletin will be  released at the annual CDA conference to be held from Oct. 6 to 9, 2014. Further guidance on  management and operation of tailing dams is available from the Mining Association of Canada.
There has been some confusion in the media with respect to CDA’s role in the regulation of dams. CDA  publishes guidance on the design, construction and safe operation of all dams including tailings dams. In  Canada, the licensing and regulation of dams is under provincial or territorial jurisdiction. While our Dam  Safety Guidelines and technical bulletins provide valuable assistance to regulators, dam owners and dam  managers, they are neither standards nor regulations. The Canadian Dam Association has no regulatory  authority.   The Mount Polley tailings dam failure illustrates the need for continual vigilance among mine owners,  dam safety engineers, operators, and regulators. The Canadian Dam Association supports efforts to  advance understanding and practices to improve safety at all dams.

In the past year I have done dam safety inspections for eleven tailings facilities from northern Quebec through the USA and Central America to South America. Obviously I read the guidelines noted above in detail before undertaking this task, and many times during the work.

My opinion: the guidelines are all good and informative, but they are timid. They were written by those sympathetic and beholden to the mining industry and thus they were written so as not to offend anybody in mining. They were written to encourage miners to do better. But they make no demands that involve too great an effort or expenditure.

Another opinion: if you need these guidelines to tell you how to undertake a dam safety inspection, you better not undertake the dam safety inspection, for the guidelines are far below the degree of experience and expertise needed to undertake a professional, thorough, and competent dam safety inspection.

To take one example. There is a call in the APEGBC document for peer review. This is how it is stated:

An independent peer review is an additional level of review beyond the minimum requirements of Bylaw 14(b)(2) that may be undertaken for a variety of reasons (such as those listed in section 4.3) by an independent Qualified Professional Engineer not previously involved in the project. At the discretion of the Qualified Professional Engineer, in consultation with the reviewer(s) involved in the regular checking/review process outlined above, such an additional level of review may be deemed appropriate.

Alternatively, a local government or other approving authority may request an independent peer review to support project approval. An independent peer review may be undertaken by another Qualified Professional Engineer within the same firm, or an external Qualified Professional Engineer.

The independent peer review process should be more formal than the checking/review process carried out under Bylaw 14(b)(2). An independent peer reviewer should submit a signed, sealed and dated letter or report, to be either included with the dam safety review report or put on file, which includes the following:

• limitations and qualifications with regard to the independent peer review; and
• results of the independent peer review.

When an independent peer review is carried out, the Qualified Professional Engineer who signed the dam safety review report remains the Engineer of Record.

The independent peer review discussed above is not the same as an independent review or advisory service provided by a Qualified Professional Engineer who is retained by the Regulatory Authority, or sometimes a client.

Pusillanimous, is all I can conclude.

So sadly, I must conclude that even if the guidelines had been fully implemented at Mt Polley, which I am sure they were not, the failure probably would not have been avoided.

Fact is folk, that the best standards of practice internationally on big and important tailings dams involves at least the following:

• An annual report by the Engineer of Record on what was done at the dam by way of design, construction, deposition, and instrumentation during the preceding year.
• A report by an independent and different engineering firm of the status of the dam. In South Africa as a result of the Bafokeng and Merrispruit failures, this is done every three months.
• Annual or more frequent meetings by an independent panel of three senior peer reviewers. All the oil sands tailings impoundments have peer review boards. Nordie Morgenstern, to my knowledge, sits on those of Suncor and Syncrude.

I bet you none of this (these?) are done on any BC tailings dams. Certainly they were not done at Mt Polley. And none of the guidelines I mention above mandate these actions. Why? As I noted, to do so would offend the mining industry and result in rejection of the guidelines.

Sad but true. Thus I must conclude that the new independent review panel must find that the international standards of review were not followed, that Canadian guidelines do not mandate the same, and that if we are to preclude future failures of Canadian tailings facilities (four in the past two years) we are going to have to make major changes to the way we work.

This is not a matter or one in a million as Dirk van Zyl says. It is a matter of one in five thousand—each and every year and thus worthy of major attention and change.

As a result of postings on this blog, I get private emails from people on almost every topic.  Here is one such email that is a cry from the heart, a sad tale, related to mining, and so difficult that I cannot answer it.  I have the sender of the email’s permission to post the following in the hope that somebody, maybe one of the blog’s readers can help.

Some years ago I was very young & expecting my first child. In those days as you may know, a lot of the young boyfriends got scared & ran from their responsibilities.  I had the child which was a girl & have been looking ever since for her father, later at her request.

I am embarrassed because I remember giving the adoption agency his name hoping that he would come again but did not.

I was so upset that I didn’t want to remember him or his name so I blocked it out.  I needed to tell you all of this first. We have a good relationship my daughter & I.  I really want to help her in every way I can to find her father’s family.

This was back in the 60’s.  My daughter found out through the adoption agency that the man, her father died in a work related accident when he was in his 20’s, in the diamond mine in Noranda Que.  He was in his 20’s when I was with him & I was thinking he was maybe going to call me. Now I will never know.

This does not matter anymore because I am elderly now & just trying to help her. Her father worked in the Diamond Mines in Noranda Que.  He was from St. Lambert Que.  The accident would have happened in the 60’s.  This is all the information I have.

The laws in Que., are a lot stricter than any where else as far as giving information out. I think it is not right in this case because her father died. She really needs some closure. She wants to go to his grave.

I saw you on one of the sites I looked up on engineering & mining. The one with the nice poem.  I only want to know if you can help me in any way just to even give me some advice as to where I can start. Maybe some accidents in the mine of names in the 60’s.

Would you know of anyone in the company that may be able to guide me, maybe human resources or a name of someone that would help us.    I do not know your name, honestly I immediately went to e-mail you as soon as I saw it.

Even if you could give me an e-mail or the address of the diamond mine in Noranda Que. I googled it but came up with so much. I didn’t know which one to pick & there were no names. I would appreciate this a lot. I really am sorry to bother you about this but I am trying hard to get something before something happens to me & I won’t be able to help her. Should I contact human resources, if so do you have an address at that diamond mine in Noranda Que. Lot’s of if’s.

I replied that to my knowledge there were no diamond mines in Quebec in the sixties.  But maybe I am wrong.  So if you can help this lady, please email me at jcaldwell@infomine.com.   Thanks.

While we in BC have been preoccupied by the Mt Polley situation, yet another tailings failure has occurred.  This time in Mexico.  That brings the number of failures this year to three:  Duke Energy, Mt Polley, and Cananea.  Just the right number if the probability of failure is one in five thousand.

Reporting on the failure is sparse.  Here from the Mexico News Daily:

Negligence on the part of a copper mine in Cananea, Sonora, has been blamed for the spill of 40 million litres of copper sulphate into the Sonora River last week.

An earlier report by the environmental agency Profepa said it was sulfuric acid that was released by the Buenavista del Cobre mine, owned by Grupo Mexico. Arturo Rodríguez Abitia, assistant prosecutor of industrial inspection at Profepa, said the copper sulphate will have an environmental impact for its acidity. It is corrosive but will mix with the river water and become diluted and neutralized, he explained.

The tailings pond spill also contained heavy metals in concentrations that exceed health standards but are within those for environmental protection.

Residents of several municipalities are using potable water supplied by the government since their water systems, which draw from the Sonora River as well as the Bacanuchi, another river affected, have turned off the pumps.

Rodríguez said the mine acted in a negligent manner for not having monitored the release of the contents of the tailings pond. He said Profepa will be looking to apply the highest penaly possible, which is about 3 million pesos.

Monitoring of the mining industry is reported to be insufficient because three different agencies are responsible: Profepa, the Environmental and Natural Resources Secretariat (Semarnat), and the Economy Secretariat all have a role to play.

In saying the mine was at fault, Rodríguez said there should be control and emergency systems in place should a toxic spill occur, and the waste materials would be trapped by another pond to avoid being released into the river.

Detection systems to warn of a problem should also be in place.

Local officials said last week that the mine made no attempt to notify authorities of the incident. The water commission was advised by a municipal president.

Another mine in Durango was also faulted, in this case for a cyanide spill. Proyecto Magistral in El Oro released 2 million litres of water containing the compound, but it was reported to have been neutralized.

The Arizona Daily Star fills in a few details:

On Aug. 7, about 10 million gallons of mining acid spilled into the Sonora River, which supplies Hermosillo — Sonora’s capital — and tens of thousands of residents in various towns with drinking water. Sonoran state officials said residents alerted authorities to the spill while Grupo México, the mine’s owner, did not notify the state.

Tucson attorney Jesus Romo, who also lives in Banámichi, one of the affected towns, said the spill portends potential future damage from larger tailing ponds near the river.

“If they burst, it can mean the end of people living along the river,” he said.

The tailing pond that broke was more then 1.4 million cubic feet (40,000 cubic meters), but the others have have billions of cubic feet, he said.

The Sonoran government announced Monday that it has provided about $38,000 to each of the seven municipalities affected by the spill: Arizpe, Banámichi, San Felipe de Jesús, Baviácora, Aconchi, Ures and Hermosillo.

The World Socialist Web Site talks of a spill from a holding tanks, so this may not be a tailings falure after all.  Here is what they write:

Over 10 million gallons of toxic wastewater leached from a copper mine near the town of Cananea in northern Mexico spilled into the nearby Bacanuchi River on August 6. Reports indicate that copper waste tailings containing sulfuric acid and heavy metals leaked for more than a day from a holding tank into the river after heavy storms hit the region.

Hopefully we can get more definitive information.

The numbers just do not add up. As I read the many sites on the web, I learn that British Columbia has about thirty operating mines. The BC government has about $172 million in closure bonds. Say about five or six million a mine. That seems grossly inadequate to me. I have just finished estimating closure of one mine and it came to nearly $60 million. Does this mean BC should have $1.7 billion in closure bonds? Here are some observations from various websites that may help you ponder this issue.

From the British Columbia government website:

MEM seeks to provide reasonable assurance that the Province will not have to contribute to the costs of reclamation if a mining company defaults on its reclamation obligations. As a condition of Mines Act permits, the permittee must post financial security in an amount and form acceptable to the Chief Inspector of Mines. This security is held by the government until the Chief Inspector is satisfied that all reclamation requirements for the operation have been fulfilled.  Every mine site has unique management requirements and operational constraints; thus, the assessment of financial security is done on a site-specific basis. The security is set at a level that reflects all outstanding reclamation and closure obligations. For example, mines that require long-term drainage treatment for metal leaching and/or acid rock drainage require full security to cover outstanding liability and ongoing management.

The Fair Mining Collaborative tells us this about closure bonds in other jurisdictions:

BC law does not specify a minimum amount of security. This differs from other jurisdictions where minimum securities have been set. For example, in Montana the legislation mandates that a minimum security of $200/acre is required. In New Mexico, a minimum security of $10,000 is legally required. In India, different minimum securities are required for different categories of mines: larger securities are required for mines that require heavy machinery to perform operations such as deep-hole drilling, excavation, loading and transport. In Western Australia, as of January 1st 2012, tailings facilities were bonded at a minimum rate of A$18,000 per hectare, and waste rock piles are bonded at a rate of A$15,000 per hectare.

The Juneau Empire commenting on the KSM mine says this:

The bond KSM will be required to post has been a large concern for many Alaskans; the cost just to treat the water flowing over the mine site and into the Unuk River, which will be necessary at least for 200 years after the mine’s closure, is estimated at current prices to cost around $25 million per year, according to Seabridge Gold Inc. Vice President of Environmental Affairs Brent Murphy. Seabridge is the company behind KSM.

Now to the costs of Mt Polley. The Vancouver Observer notes:

Analysts say cleanup costs for Imperial Metals’ Mount Polley tailings disaster could cost anywhere from $50 million to $500 million, but the security bonds available today to help cover that are now a fraction of that.

Documents from the Ministry of Energy and Mines on July 25, 2013 suggest that Mount Polley Mining Corporation (owned by Imperial Metals) was expected to pay security bonds of $38 million by 2023, and that it had deposited $14.5 million as of March 2014.  The Ministry said clean up is expected to be paid for by the company. But when the Vancouver Observer asked what would happen in the event that Imperial Metals went bankrupt, a media representative from the Ministry wrote in an email:

“The Ministry of Energy and Mines holds $14.5 million in security bonding for the Mount Polley mine in the event that the company defaults on its responsibilities.”

But critics have warned in the past that the amount of funds available through security bonds is far less than the mining industry’s liabilities. A report in 2001 by West Coast Environmental Law warned that the liabilities of BC mines far outweighed the total amount available in reclamation bonds. The report estimated BC mine reclamation liabilities at the time to be around $400 million, but the total available in bonds was less than half that amount, at just $172 million.

The Globe and Mail gives us the number of mines in BC.

The independent inspections of all other B.C. tailings ponds must be completed by Dec. 1. The province currently has 98 permitted tailings ponds at 60 operating and closed metal and coal mines. Thirty-one of the ponds are at active mines.

If there are but thirty one tailings ponds to be closed and the total in bonds is $172 million, that works out at about five to six million per mine or per tailings facility, not quite sure.

In a detailed paper Hutchison and Detorre say this about mine closure costs:

• Using an “optimistic” approach and assuming that the lowest cost elements are going to be required yields a total closure cost of $16.1 million. This has been the approach in some instances in the past. Using the worst case assumptions yields an unrealistically high cost of $57.0 million.
• Using the conventional approach and selecting the most likely costs for the highest probability closure elements yields a total closure cost of $29.8 million. This is often the approach used in the mining industry.
• The statistically based expected closure cost is $29.0 million.
• The statistically based most likely closure cost is $34.3 million. At a 90% confidence level the most likely cost is $36.4 million. These costs are higher than the conventionally estimated costs.

Goldcorp says this of their closure cost obligations:

Effective January 1, 2003, Goldcorp adopted accounting standards under both Canadian and US Generally Accepted Accounting Principles (GAAP) relating to Asset Retirement Obligations. The two standards, CICA 3110¹ and FAS 143², are substantially the same. In general, these standards apply to legal obligations associated with the retirement of a tangible long-lived asset that result from its acquisition, construction, development or normal operation. Goldcorp’s provision for closure amounted to $298.9 million in 2010, compared with a provision of $306.5 million in 2009. The slight drop in provision for 2010 is due to the closure work completed during the year, particularly at the San Martin and Porcupine mines.

Whatever the correct numbers, it is clear that you cannot close a mine for less than $50 million. Thus if BC has 30 operating mines, MEM should have $1.5 billion in the bank, not a mere $172 million.  Maybe we can get MEM to correct me if I am wrong.  Please weigh in with your comments.

Sometimes a blog is just that: a biographical log, a diary, a record of daily thoughts & doings. So here are a few random thoughts & doings from this weekend.

No Mt Polley except yesterday’s ruminations on the inadequacy of bonds for mine closure.  Some good comments.  See previous posting.

The weekend started with a lover: the blond hairs turned golden in the rays of the setting sun. And the rest is unrecordable.

Then to the problem of a leaky tap.  A trip to Home Depot to get a replacement only to find half the parts were missing from the box and hence return to the store to get another.  And when installing it, I broke the copper pipe.  Now a genuine plumber will help me at some enormous expense.

Last night I watched a new version of Otello by Rossini–not the Shakespeare version this.  Cecelia Bartoli and John Osborn give us something entirely new and different.  Although I have seen a different version that I cannot now locate.  Nowhere as dramatic as Verdi’s version but much nicer music.  Here is what Wikipedia says of Rossini’s version:

The opera deviates heavily from Shakespeare’s original, not only in that it takes place in Venice and not on Cyprus, but also in that the whole dramatic conflict develops in a different manner. The role of Iago is reduced to some degree, and it is much less diabolical than in the original or in Verdi‘s Otello of 1887. In further contrast, the role of Rodrigo, of subsidiary importance in Shakespeare and Verdi, is very prominent in Rossini’s version and is assigned some of the most difficult and brilliant music.

Keep in mind that Verdi was nearly 70 when he wrote his version of Othello.

After the completion and premiere of his opera Aida in December 1871, Verdi decided that it was time for him to end his successful career as a composer of opera, much as Rossini had done after the completion of the opera William Tell, though he was easily the most popular, and possibly the wealthiest, composer in Italy at the time. However, Verdi’s sixties were not good years: as musicologist Julian Budden notes, “he seemed to have entered [those years] in a mood of gloom and depression [..and..] his letters at the time were full of complaints about the Italian theatre, Italian politics and Italian music in general [all] seen by him as sinking beneath a tide of Germanism”.^[2]

The process of writing the first drafts of the libretto and the years of their revision, with Verdi all along not promising anything, dragged on. As Walker charts it, the opera was completed:

in three comparatively short bouts of composition: the first, very brief, was at Genoa in March 1884 [five years after the first drafts of the libretto began!]; the second, the principal one, at Genoa from December 1884 to April 1885; the third at Sant’ Agata from the middle of September to early October 1885.^[16]

By late August 1881, it appears that the text of the finale of act 3, over which there had been some considerable discussion (with ideas exchanged between both men) was sent to Verdi, who responded in a long letter from Milan regarding his feelings about its overall structure, the role of the chorus, and other issues.^[17] Throughout 1882 and 1883 very little happened, although during the winter of 1883 Verdi and Boito met in Genoa where the Verdis spent their winters, but it prompted Ricordi for three Christmases in a row to send a cake to Verdi with the figure of the Moor—in chocolate—on the top.^[18] In order to keep information about the composition within the group, this gesture may have been the cause for the name given to the project for many years, “chocolate”, as in Boito’s letter of 1864 noting that “the manufacture of chocolate was going ahead”.^[19]

Tonight was a new version of Orfeo ed Euridice by Christhoph Willibald Gluck.  I have four other DVD of this same opera, plus I have the Monteverdi L’Orfeo and the Orpheus in the Underworld of which Wikipedia says:

Orphée aux enfers (Orpheus in the Underworld) is an opéra bouffon (a form of operetta), or opéra féerie in its revised version, byJacques Offenbach. The French text was written by Ludovic Halévy and later revised by Hector-Jonathan Crémieux.

The work, first performed in 1858, is said to be the first classical full-length operetta.^[1] Offenbach’s earlier operettas were small-scale one-act works, since the law in France did not allow certain genres of full-length works. Orpheus was not only longer, but more musically adventurous than Offenbach’s earlier pieces.^[2]

This also marked the first time that Offenbach used Greek mythology as a backdrop for one of his buffooneries. The operetta is an irreverent parody and scathing satire on Gluck and his Orfeo ed Euridice and culminates in the risqué Galop infernal (“InfernalGalop“) that shocked some in the audience at the premiere. Other targets of satire, as would become typical in Offenbach’sburlesques, are the stilted performances of classical drama at the Comédie-Française and the scandals in society and politics of theSecond French Empire.

Bejun Metha plays Orfeo with his incredible countertenor voice.  I could listen to the sound all night.  It is pure beauty of sound.  Plus what an actor!

All tell the sad tale of the grief of Orfeo when his wife, Euridice, dies.  Orfeo goes to the underworld to claim he back.  He placates the furies with his harp.  But he is forbidden by Amor to look at Euridice before they get back to the upper world.  She, silly lass, makes a great fuss and forces him to look at her and she is lost to him forever.  Tonight’s version has Amor relent and let Euridice come alive again and go back to Orfeo.   Opera at its best and silliest.  And as good a way to end the weekend and plumbing tribulations.

In past postings I have provided Canadian mining wages and salaries from the CostMine 2014 Canadian Mine Salaries, Wages, and Benefits Report.  As noted on the CostMine website, this report provides the following:

• Hourly wage scales listed by job title for workers at 66 metal, diamond, industrial mineral and fossil fuel mines in 9 provinces and territories, including Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland, Northwest Territories, Nunavut, Ontario, Quebec and Saskatchewan.
• Salary summaries for managerial, technical and administrative personnel at 46 mines.
• Benefit plan profiles for each mine.
• Incentive bonus plan descriptions for many new and innovative plans reported by the mines.
• Statistical tables for comparing salaries and benchmark wages at surface and underground mines.
• Executive Compensation for 38 Canadian and American major, mid-tier and junior mining companies.
• Workers compensation tax rate summaries for mining in all provinces and territories.

Now let us examine a few facts about mining executive compensation.   Here are some average compensation (in $1,000) for Junior mining companies:

• CEO = 533
• President = 858
• Vice President = 706
• CFO = 245
• COO = 245

Now let us look at the same folk working for Major mining companies:

• CEO = 5,759
• President = 4,276
• Vice President = 2,399
• CFO = 2,495
• COO = 2,360

In very round numbers, the executive in a Major make about ten times as much as in a Junior.  Talk of a wide income distribution.  And these are averages.  Here are some maxima, first for the Major, then the Midtier, then the Junior:

• CEO = 9,898/3,854/3,924
• President = 9,898/3,854/3,924
• Vice President = 6,246/2,728/2,153
• CFO = 6,246/2,728/1,615
• COO = 5,334/1,402/340

Some top guys in the Juniors are doing well, although but a third of their Major counterparts.

Keep in mind that the above are not salaries.  The numbers include

• Salary
• Share-Based Awards
• Options-Based Awards
• Non-equity income
• All Other (presumable cars, planes, and clubs)

Still I suppose these guys work for it, considering the turn-over and tribulations they face when things go wrong.

The oft-asked question I get is this: how do you prevent a recurrence of the Mt Polley failure?

I have touched on some aspects of the answer in previous postings.  But let me, here, state my opinion succinctly.  Sure to be controversial, but this is what I truly believe is necessary to prevent a recurrence of Mt Polley, at least here in BC.

At least the following should be done for every tailings facility (in BC?):

Responsible Engineer:  There must be an engineer of record for each and every tailings facility.  Preferably this should be a named professional engineer.  I may countenance a company, but I prefer a real live person.  The responsible engineer must know all the facts of the facility and should feel free to offer his or her opinion without fear of dismissal or reprisal.  The responsible engineer should issue an annual report on construction and operation of the tailings facility–this report must be provided to the regulators.

Peer Review Committee:  This committee should include at least three senior persons knowledgeable about tailings management.  They should be independent of the company or person who is the responsible engineer.  They should meet at least once a year and preferably twice a year.  Their reports should go to senior management and to the regulators.

Dam Safety Engineer.  This person must be independent of the responsible engineer and the peer review committee. They should inspect the tailings facility at least every three years and report on the safety of the facility.  Their reports must go to the regulators, the peer review committee, the engineer of record, and mine management.   Preferable a different person should do the dam safety evaluation each time–no point I getting a built-in bias.

Mine Tailings Engineer.  There should be at every mine an engineer designated in charge of the tailings facility.  These folk need not necessarily be registered professional engineers, although that would be good.  But they must have experience and the ability to act when things need attention.

Trained Operators:  The people who run the tailings facility on a daily basis should be trained in what they do.  I would recommend that APEGBC or similar run the courses.  The operators should present to the peer review committee their observations and opinions without fear of reprisal.

Professional Regulators:  The regulators, MEM in the case of BC, should have on staff professional engineers who are able to review all reports and who have the power to make the mine do what the responsible engineer, the peer review committee, and the dam safety engineer recommend.

As far as I know, it is only at the oil sands mines that this system is in place.  And they have a good record.  Of course there is controversy about the oil sands tailings facilities.  But from personal experience, I know the system works and weeds out incidents and errors before they lead to failure.

In support of my proposition, see the recent piece by Gordon Hoekstra of the Vancouver Sun which reports as follows:

Dangerous occurrences at tailings storage facilities at mines in B.C. between 2000 and 2012 included a breach of a dike, the discovery of sinkholes and leaked tailings.

The B.C. Ministry of Energy and Mines provided details of 49 dangerous occurrences at tailings ponds at the request of The Vancouver Sun following Imperial Metals’ Mount Polley tailings dam collapse on Aug. 4.

The chief inspector of mines’ annual reports provide an annual breakdown of the number of dangerous occurrences, but the mines ministry initially balked at providing details of the dangerous occurrences, requested 10 days ago.

That is a lot of incidents!  The sinkhole incident in particular would have worried me.  Which only goes to show that in addition to all I  have suggested above, the regulators should be required to post on an easily accessible website, all reports from the mine, the responsible engineer, the peer review committee, and the dam safety engineer.  In addition the regulators should post all their correspondence with the mine.  Open information is the best way to guarantee safety.  Hiding it behind wall of confidentiality is a sure way to another failure.

On which, I cannot but wonder when we will get at least the following about Mt Polley:

• The original design report.
• Knight Piesold subsequent design changes.
• The AMEC design change documents
• The AMEC annual reports.
• Peer Review reports
• The Dam Safety reports whose  authors I know not.

I presume these reports exist, for if they do not, I have proven my point: not all was done as it should have been done, and the failure occurred.  And if they do not exist, how can the expert panel make any decision or recommendation other than what I write here?  And if they exist and are given to Messrs. Morgenstern, Vick, and Van Zyl why should we ordinary mortals not see them too?

Finally, we the public should be entitled to see the mine closure plans and cost estimates.  As I noted in a previous posting I think these are grossly inadequate.  Let us see this from MEM:

• A list of BC mines
• The Closure Plans
• The cost estimate for closure.

It should all be so easy, but it is not.  Why?

There is a great silence of information about the geotechnical issues possibly involved in the failure of the Mt Polley tailings dam.  No reports have been released; no letters published; no statistics provided.  Oh sure, a few old numbers of incidents in 2012, but the 2013 report is not yet ready.

As in any place silence breeds rumours.  People will talk and speculate, in spite of a promised independent report sometime next year.  I well recall the government in South Africa in the old days believed that if they kept us ignorant and silent, they could perpetuate apartheid.  That very upper class British attitude was behind the Dutchmen’s folly in South Africa and in British Columbia the British upper class belief that information is only for the upper class or a limited number of chosen few is still very much the prevailing ethic.  So we the general public remain ignorant and uninformed as the rulers keep tight reign on information that in a democracy should long ago have been public.

Luckily today we have a tool to beat the rulers that did not exist in apartheid South Africa and of which the British Columbia rulers still seem ignorant: we have blogs.  Scurrilous things, by opinionated fools, who are often drunk when they write.  And thus let me exercise my free right to blog (Libera me as the Scots sing in MacBeth of the oppressive British.)

As a blogger, many free people have sent me information and opinions and pictures.  The one above is one of them.  It shows the corner of the Mt Polley dam that failed when tailings were first being placed.  This is a fascinating photo.  Notice that at the corner where failure occurred there is on the upstream side a kind of dark line running up the upstream face of the embankment.  I have studied this long and hard and cannot make out what it is.  But it is something different.  Is it a trench, a zone of different material, a crack repair, a discontinuity of embankment construction where the two embankment meet?  Doe it have anything to do with the later failure?

Now take a look at the photo below, obviously taken some time after the first one.  They are still discharging tailings from the north side and they are still creating a fan beach with its crest near the corner that failed.

Now I see something very interesting on this photo.  Notice that the fan beach of tailings seems to be bounded to the left of the fan by a topographic rise–the kind of green area on the left hand side of the white tailings.  Now draw a line along the intersection of the green (vegetation?) and the white tailings.  Draw the line upwards, and it goes through the dike or embankment and seems to continue on the downstream side of the embankment.

Is this “line” a distinct topographic break–maybe there was a cliff along that line and that is why the tailings fan did not rise up above it.  Maybe there was a bedrock break along that line—so to the left, the foundation was solid.  And maybe to the right of the line, the foundation was soft soil—and the foundation had a tendency to settle when loaded.

If this idea is correct, we could ascribe the embankment failure to differential settlement more or less at the corner:  the embankment on rock foundation did not settle, whereas the embankment on a soil foundation did settle.  The result would be a crack at the corner through which water poured.

Recall that this was the cause of a tailings dam failure a few years ago in some South American country whose name begins with G.  I have the full story but have been sworn to silence as ………..you know the rest.

Now look at this picture below.  This is after the failure.  It appears as though there was an upstream failure of the embankment.

The obvious reasons for an upstream failure is what we dam engineers refer to as rapid drawdown—when the level of water is lowered fast, excess pore pressures in the dike cause upstream failure.  Bet nobody considered that when they decided to lower the water level as ordered to do so by the regulators.

Of course if a crack due to differential foundation settlement caused all the water to rush out, as it did, then there was a dramatic instance of rapid drawdown failure at work.  But that make rapid drawdown a result not a cause of the failure.

So a few sketch to further illustrate things.  First below the situation before failure.  I do not know how high the dam was, or how high the tailings behind the dam, or what the depth of water was.  But even to the uninitiated it is obvious this is not a stable situation—vertical walls of soil bounded by water do not stand up.  Try this if you doubt me: dig a hole in your garden.  Make the side of the hole vertical.  Fill the hole with water.  In a short time the side of the hole will fall in.  That is probably what happened at Mt Polley.

Next a sketch of what there was after failure. namely an upstream arc indicative of upstream failure.

Here then is a sketch that shows how and why upstream failure may have occurred.  The water seeps through the soil.  The water pressure pushes against a zone of failure as shown here bounded by the potential failure plane.  In the case of Mt Polley this became an actual failure plane.

To be thorough, let us record the possibility that piping was the cause of failure.  Professor Jennings was convinced this was the cause of the failure of the Bafokeng dam in 1972.  In short there is a layer of more permeable soil sandwiched between two layers of less permeable soil.  Water obviously flows preferentially through the more permeable soil.  If it flows too fast, it kind of erodes the more permeable soil.  Some of the pictures of the failure zone that I have seem to show layers of soil of very different type—whether the different types of soil include different permeabilities, I do not know.  That should be in those construction reports that are under lock & key to which only the upper class is granted access.

Finally there is the possibility, as shown below, that outward movement of the adjacent embankments at the corner caused a crack to form.  Recall this is what caused the failure of that tailings facility a few years ago in Hungary that resulted in tailings in the Danube.  The figure below is a plan view of the two adjacent dikes that came together at the corner that failed.  The big blue arrows are the force the water imposes on the dikes.  If there is outward movement as a result of these force, the corner cracks and there is failure.

On the issue of secrecy, have you seen today’s comment on a previous blog posting to this effect:

I’ve learned (but not substantiated) that there were at least two independent third-party reviews of this facility, and yet it still failed. Clearly the reviews themselves are not enough to prevent failure.

This is new to me and certainly not hitherto mentioned.  It will be interesting to see these reports if indeed they exist.  I confess, I probably would not have worried too much about this corner if I had been doing the dam safety inspection.   How often do we look at the foundation conditions that are the basis of design?  Funny thing happened on the way to the forum.  A while ago I did a dam safety inspection and determined that the design engineers had done no borings to establish foundation conditions.  In fact they are terrible—both the design engineers and the foundations.  But that is another story, for another day, many years hence.

At this link is a great Master thesis recently completed by Genki Taguchi, a student of the University of British Columbia.  He is now back in Japan working in the coal mining industry.  Dirk Van Zyl supervised the thesis.  And if that link does not work, here is a second link.  A great job by both.  And a document which should become required reading by all in tailings.

The thesis is call Fault Tree Analysis of Slurry and Dewatered Tailings Management – A Framework.   I helped him a little by suggesting that he go back to the Bafokeng tailings failure and analyze the failure using the methods he writes of.  He does a superb job and to my mind sheds new light on what may have happened.

He has prepared fault trees to quantify the probability of the main culprits that may have caused the failure: piping, static liquefaction, bulldozer error; penstock failure.  Then he does some simple slope stability analyses and shows that the factor of safety at the time of failure was just about unity.  He concludes:

It turns out that the likelihood of static slope instability is very high as a result of fault tree analysis. Although the static slope instability would be the main failure of Bafokeng TMF, it seems to be reasonable to think that not only one failure but also a string of failures triggering each other causes this disastrous failure.

I concur.  After the Bafokeng failure, I was involved with three other similar dams, of similar construction, similar tailings, and identical foundation soils.  They all failed by slope instability.  Luckily we had arranged to have the water off the top as a precautionary measure and so there was no off-site flow.

To give you added reasons to download the thesis, here is the abstract.

Fault trees are used in reliability and risk analysis to develop the probability of occurrence of the top event, or failure mode. The top event results from a logical sequence, or combination, of lower level events using “and” and “or” logic.

Probabilities for the basic events, i.e. the lowest level events identified, are calculated or estimated in order to calculate the probability for the top event.

This thesis develops a framework for fault tree analysis for failure of alternative tailings depositional schemes (slurry, thickened, paste and filtered). Failure is narrowly defined as the release of tailings to the environment. The following failure modes are evaluated for each of the depositional schemes: overtopping, static liquefaction, internal erosion, static slope instability and seismic slope instability.

The fault trees are representative of potential failure sequences in the industry as a whole and not on site-specific conditions. Expert elicitation methods are used to select the likelihoods of the basic events.

Not all events in the fault trees are applicable to the range of depositional schemes, e.g. overtopping as a result of a large pool on slurry deposited tailings management facilities is not an event that will occur for filtered tailings. The outcome is that some of the events and parts of fault trees “fall away” as the tailings solids content increases. Apart from providing a visualization of the reduction in probability of occurrence of the top events for the failure modes, the results also provide a range of probabilities for the overall probability of failure for the range of tailings management options.

The framework is used to develop a site-specific likelihood of failure of the Bafokeng tailings facility. The result demonstrates that the fault tree framework can provide useful insights in both industry-wide and site-specific tailings management facility failure likelihoods.

 I wonder if it will take as long for us to compile the fault tree of the Mt Polley tailings failure?

The Tyee, a local Vancouver newspaper at this link, with some amazement recognizes with regard to the Morgenstern, Vick, and Van Zyl panel:

In the probe the government has set up, there is mandated virtually no investigation of the role of the mining or environment ministries. There are 14 terms of reference, 13 of which deal strictly with the collapse itself, one of which may be interpreted as giving the panel members the right to look at the government’s role if they feel so inclined.

It does not take brain surgery to recognize that this panel is unsuited to look at any regulatory role the government should have played. That’s not their bag. They are picked for their skills at investigating mining methods, not regulation enforcement.

To look at a government role and the law and regulations requires a specific sort of person, and it’s difficult to think of anyone suited other than a highly experienced lawyer or judge. To even begin to know the right questions requires a training that a scientist doesn’t, by nature, have. He or she may be highly skilled and trained, but not for this purpose.

I looked up the scope of work for the panel.  Here it is:

The purpose of the panel is to investigate into and report on the cause of the failure of the tailings storage facility that occurred on Aug. 4, 2014, at the Mount Polley mine in B.C. The panel will report on the cause of the failure of the tailings storage facility at the Mount Polley mine. In addition, the panel may make recommendations to government on actions that could be taken to ensure that a similar failure does not occur at other mine sites in B.C.

The panel is authorized, as part of its investigation and report, to comment on what actions could have been taken to prevent this failure and to identify practices or successes in other jurisdictions that could be considered for implementation in B.C.

Scope of Review

In its report, it is expected the panel will:

1. identify any mechanism(s) of failure of the tailings storage facility;
2. identify any technical, management, or other practices that may have enabled or contributed to the mechanism(s) of failure. This may include an independent review of the design, construction, operation, maintenance, surveillance and regulation of the facility;
3. identify any changes that could be considered to reduce the potential for future such occurrences.

In conducting its investigation and in order to prepare its report into the cause of the failure of the tailings storage facility at the Mount Polley mine, the Panel may, at its discretion, and as it deems necessary, examine some or all of the following in respect of the Mount Polley mine in B.C.:

1. geotechnical designs of the dams and structures associated with the TSF, including both intact and breached embankments, and including both the original design and all lifts of the embankment structure;
2. the adequacy of geotechnical investigations completed throughout design and operation of the facility;
3. interpretation of results of geotechnical investigations and associated laboratory testing;
4. patterns, trends, and relationships in instrumentation behaviour;
5. interpretation of instrumentation and performance data in relation to dam behaviour;
6. whether or not dam instrumentation and monitoring was consistent with standards of practice;
7. appropriateness of methods and input parameters for geotechnical analyses;
8. materials, methods, procedures, and quality assurance/quality control practices for dam construction and modification, and a determination with respect to whether or not construction was completed in general conformance with the design;
9. water balance and water quality as they relate to the TSF breach;
10. operational procedures and planning for tailings deposition and water management;
11. inspection and surveillance procedures and implementation;
12. the engineer of record’s field reviews to ensure that construction was in conformance with design;
13. regulatory oversight by the Ministry of Energy and Mines and the Ministry of Environment; and
14. other matters the Panel deems appropriate to be examined.

Precisely. The panel is intended to tell geotechnical and tailings engineers what went wrong, be it design, construction, or operation. The panel may comment on regulatory oversight with respect to the engineering, but I doubt if it is intended to look into regulatory and policy procedures.  Indeed Messrs. Morgenstern, Vick, and Van Zyl are not the best people to do that.  That undoubtedly falls outside of their scope of experience and competence.

All this debate set me thinking, so to relieve the pressure, I sketched the following which shows my current favorite explanation for failure.  I wonder if there was not a change of foundation conditions at the corner.  On one side the foundation materials were good and stiff and on the other side a bit softer.  Hence there would have been differential settlement leading to embankment cracking.

As I wrote in a previous posting:

Now take a look at the photo below, obviously taken some time after the first one.  They are still discharging tailings from the north side and they are still creating a fan beach with its crest near the corner that failed.

Now I see something very interesting on this photo.  Notice that the fan beach of tailings seems to be bounded to the left of the fan by a topographic rise–the kind of green area on the left hand side of the white tailings.  Now draw a line along the intersection of the green (vegetation?) and the white tailings.  Draw the line upwards, and it goes through the dike or embankment and seems to continue on the downstream side of the embankment.

Is this “line” a distinct topographic break–maybe there was a cliff along that line and that is why the tailings fan did not rise up above it.  Maybe there was a bedrock break along that line—so to the left, the foundation was solid.  And maybe to the right of the line, the foundation was soft soil—and the foundation had a tendency to settle when loaded.

We will know someday. So to pass the time I compiled the following fault tree of possible failure modes.  Set to do this by the previous posting where I wrote:

At this link is a great Master thesis recently completed by Genki Taguchi, a student of the University of British Columbia.  Dirk Van Zyl supervised the thesis.  And if that link does not work, here is a second link.  A great job by both.  And a document which should become required reading by all in tailings. The thesis is call Fault Tree Analysis of Slurry and Dewatered Tailings Management – A Framework.

As Dirk was the supervisor, he may choose to adopt this approach for the panel.   It will be fun to see.

Monday night we went to the tents at Bard on the Beach to see Shakespeare’s Opera presented by students from the University of British Columbia.

First a tail-gate meal in amongst the trees of chicken, bread, and wine.  Just the right stuff to put you in the mood for opera.  And we were not disappointed.

The students are all magnificent singers and we revel in the thought that there is such talent out there to take the place of older singers.  Opera proceeds with confidence into the future when you hear these young singers.

My favourite was Micah Schroeder as Mercutio singing the Queen Mab song from Charles Gounod’s Romeo et Juliette.  I cried during this.  As much because of the skill and beauty of the delivery as of the recollection of Bez Bezuidenhoud.  He was the head boy at Springs Boys High the year I was an imperfect prefect.  I did not play sport or sport any of those leadership characteristics the teachers sought in prefects.  But I was top of the class and a bit of a stirrer even in those days, and a sufficient number of teachers voted for me to become a prefect.  I worship Bez and followed his lead.  For he was a good person and a leader.

We put on Romeo and Juliet as the annual school Shakespeare production.  I was Friar Lawrence and Bez was Mercutio.   His delivery of the Queen Mab speech was perfect.  You could see her riding in lover’s dreams, for he was in love with that beautiful girl who lived next door to me–and she was a friend of proximity.  Here is the full speech:

 O, then I see Queen Mab hath been with you.
She is the fairies’ midwife, and she comes
In shape no bigger than an agate stone
On the forefinger of an alderman,
Drawn with a team of little atomies
Over men’s noses as they lie asleep;
Her wagon spokes made of long spinners’ legs,
The cover, of the wings of grasshoppers;
Her traces, of the smallest spider web;
Her collars, of the moonshine’s wat’ry beams;
Her whip, of cricket’s bone; the lash, of film;
Her wagoner, a small grey-coated gnat,
Not half so big as a round little worm
Pricked from the lazy finger of a maid;
Her chariot is an empty hazelnut,
Made by the joiner squirrel or old grub,
Time out o’ mind the fairies’ coachmakers.
And in this state she gallops night by night
Through lovers’ brains, and then they dream of love;
O’er courtiers’ knees, that dream on curtsies straight;
O’er lawyers’ fingers, who straight dream on fees;
O’er ladies’ lips, who straight on kisses dream,
Which oft the angry Mab with blisters plagues,
Because their breaths with sweetmeats tainted are.
Sometimes she gallops o’er a courtier’s nose,
And then dreams he of smelling out a suit;
And sometimes comes she with a tithe-pig’s tail
Tickling a parson’s nose as ‘a lies asleep,
Then dreams he of another benefice.
Sometimes she driveth o’er a soldier’s neck,
And then dreams he of cutting foreign throats,
Of breaches, ambuscadoes, Spanish blades,
Of healths five fathom deep; and then anon
Drums in his ear, at which he starts and wakes,
And being thus frighted, swears a prayer or two
And sleeps again. This is that very Mab
That plats the manes of horses in the night
And bakes the elflocks in foul sluttish hairs,
Which once untangled much misfortune bodes.
This is the hag, when maids lie on their backs,
That presses them and learns them first to bear,
Making them women of good carriage.
This is she!

Micah Schroeder brought back all those old memories and the emotions of us when we were so young.  I wish I could hear him sing it again.

Then last night I fell in love again, at a distance.  Laura Widgett as Giulietta singing Oh! Quante volte ti chiede from Bellini’s I Capuleti e I Montecchi  was the most thrilling rendition of that beautiful lament I have ever seen.  If there is a heaven, it is a place where Bellini is still composing opera.  He died in his early thirties having completed only nine operas—every one perfect.  He is my favourite opera composer.

Third favourite of the evening was Sheldon Baxter as Ford singing the angry husband from Verdi’s Falstaff.  No acting here—I believed his anger although he is almost too young to be a cuckolded husband.

We enjoyed the many fine performances by the ladies of the UBC opera program.  But maybe we could have heard more from the guys.  Brent MacKenzie as Romeo in the wedding scene was beautiful to hear.  Such a smooth tenor voice.  Surely he will go far.

No matter.  They were all so good that we surely will go see their performance at UBC coming up.  They are:

• The Bartered Bride in November 2014
• The Marriage of Figaro in February 2015
• La Traviata in June 2015.

Put them on your calender and come too.  Monday’s concert makes promise of great opera to come from UBC.

Spent today stuffing the bags to be handed to the over 150 delegates to next week’s conference here in Vancouver on Geosynthetics Mining Solutions 2014.   I also went through the volume of proceedings.  We have some amazingly interesting papers on aspects of geosynthetics use in mining new to me.  There is still time to join us on Tuesday if you push hard.

If you cannot attend the conference, the good news for today is that there is posted today a new EduMine course called Geosynthetics in Mining.  I am one of the authors along with Colleen Crystal (my daughter) and Tarik Hadj-Hamou (a very old friend).  I think you will find the course interesting.  EduMine advertises the course in these words:

Mining involves the design, construction, operation, and closure of many geotechnical structures, including: access roads, structural building pads and foundations, ponds, tailings facilities, heap leach pads, and waste rock dumps.

Geosynthetics are polymeric materials used extensively in mine geotechnical structures to enhance the performance of such structures. Geosynthetics are used in conjunction with soils and rocks to increase the overall strength of these materials, to control seepage from mine wastes and through soils and rocks, and to separate soils of different gradation and hence to limit piping and potential failure of soil structures.

This course introduces you to the types of geosynthetics used in mine structures, to the ways in which geosynthetics may be used to build safe mine structures, and to the many details that will make it possible for you to use geosynthetics at your mine to reduce costs and protect the environment.

This course describes many case histories of the successful use of geosynthetics in mining, thereby introducing concepts, ideas, details, and practical applications that you may copy or adapt to the specifics of your mine’s needs and facilities.

Then November 4 to 6 we present an EduMine live webcast Geosynthetics in Mining – Practice and Developments.  Of course we will talk about what is in the on-line course and also what we hear and learn during the conference.  So by the end of the webcast , you will be fully up-to-date with the latest on the use of geosynthetics in mining.  Specifically the webcast will:

• Describe the many current and new geosynthetics materials that are used in mining applications
• Discuss the use of geosynthetics in mine tailings facilities, heap leach pads, water retention ponds, and liners and covers
• Evaluate the challenges of using geosynthetics in the harsh environments of mines
• Describe current thinking and best practice for incorporating geosynthetics into mine waste disposal facilities that will have to last and perform in the post-closure long term
• Cover new and advanced information and solutions for the application of geosynthetics in mining
• Recap key learnings from pre-conference courses and workshops
• Review and discuss the most important conference keynote addresses and papers.

Mark at least one of these dates if you have to deal with geosynthetics in mining.  Looking forward to meeting you.