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Huge Ponds Hold Tar Sands Sludge, And Great Risks

Danielle Droitsch

Posted August 25, 2014

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On August 4, 2014, the catastrophic failure of a mining company's dam in British Columbia, Canada, released over 2.5 billion gallons of contaminated water from a containment pond into the upper Faser River watershed. Only a few hundred miles east in Alberta, at least half a dozen dams containing the wastewater from the tar sands mining industry hold more than 100 times the volume of the British Columbia release and span over 43,000 acres of Canada's boreal forest. A breach from any one of these mine-tailings ponds would pose enormous risks to local communities and the surrounding boreal forest ecosystem.

And yet, Canadian authorities offer virtually no public information about the safety of these tailings dams, which already leak millions of gallons of wastewater — containing a suite of

Tar sands tailings pond

Source:  Rocky Kistner, NRDC

toxins, such as naphthenic acids, polycyclic aromatic hydrocarbons, phenolic compounds, ammonia, and mercury — every day. Meanwhile, Canadian regulators have opted not to enforce existing laws meant to limit the volume of toxic waste produced during tar sands mining or confront the leaks. Canada’s Pembina Institute projected that the volume of tailings will grow by at least 40 percent over the next two decades. By 2060, Pembina estimates that these mine-tailings ponds, which lie amidst the Canadian boreal landscape, will grow by another hundred and twenty billion gallons.

The tailings liability

The tar sands industry's tailings problem is a growing liability and it is getting worse. The mining operations generate massive volumes naphthenic acids, polycyclic aromatic hydrocarbons, phenolic compounds, ammonia, and mercury and other trace metals, and some of these compounds are carcinogenic. For every barrel of tar sands bitumen produced (the semi-solid substance from which oil is eventually refined), 1.5 barrels of liquid waste is added to the tailings ponds. According to the Pembina Institute, at current production levels, this means that every single day, mining operations have to store 6.6 million more gallons of tailings.

Already, more than 200 billion gallons of this liquid byproduct is stored behind those massive tailing dams, covering an area larger than Washington, D.C. According to Pembina, because of weak and unenforced regulations, the volume of tailings could grow to 343 billion gallons by 2060. 

 Tar sands tailings pond

Source:  Rocky Kistner, NRDC

The risks from the ponds are well known. Last year, David Schindler, the University of Alberta’s Killam Memorial Chair and Professor of Ecology, one of Canada's renowned water scientists, warned that a tar sands tailing breach was a huge threat. In 2013, the internationally respected Rosenberg International Forum on Water Policy, hosted by the University of California, convened international water experts to evaluate threats to the MacKenzie Basin (where the tar sands are located) and concluded, "… the largest single threat to the Mackenzie River Basin would be a large breach in the tailings ponds at one of the sites where surface mining bitumen is conducted."

Northern communities living downstream from these massive tailings dams are aware and concerned about risks presented by the tar-sands industry upstream. A larger spill could threaten not just the Athabasca river but the Peace-Athabasca delta, Lake Athabasca, the Slave river and delta, Great Slave Lake, and the Mackenzie river and delta, all of which empty into the Beaufort sea. Cleaning such a spill could cost billions of dollars.

Public information is lacking

Worldwide, major failures of tailings dams — like the recent one in British Columbia — occur at a frequency of two to five per year (there are approximately 3,500 tailings dams worldwide) while 35 smaller breaches occur annually. This is a much higher failure rate than experienced by water supply or hydroelectric dams. And Canada hasn't escaped this problem.

 Accessibility of Tailings Pond Management Documents in Alberta

Just last year, a massive breach of tailings pond dam from an Alberta coal mine operation dumped 177 million gallons of water and 9.8 million gallons of sediment into the Athabasca watershed (the same watershed threatened by tar sands tailings). Despite an ongoing investigation, the cause of the 2013 breach is still unknown, though critics claim that a lack of government oversight is partly to blame.

Generally, a number of risk factors can lead to tailings dam failures. These include:

  • While public bodies often own conventional dams, tailings dam are often owned and constructed by private mining companies who view the dams as a money-draining part of their operations.
  • Unlike conventional dams, tailings dams can have a lifetime of hundreds of years and are considered  permanent fixtures on landscapes. A conventional dam typically has a lifetime of less than 100 years.
  • While conventional dams are constructed over a relatively short period, mining dams are constructed continuously over many years. As an example, the Suncor Tar Island tailings dam, originally intended to be 12 meters tall and be in use for only 3 years, has now risen to 91 meters and is more than 40 years old.

Tailings dams information is lacking

Canadian authorities share little information about the safety of tar-sands-tailings lakes.  According the Pembina Institute, key documents like emergency preparedness plans, emergency response plans, operations and maintenance manuals, tailings-dam performance reports, and dam safety reviews are kept confidential for proprietary reasons. But according to the institute, "The difficulty in acquiring information on tar sands tailings dams, combined with the government of Alberta not publicly addressing concerns on tailings dam stability, limits the possibility for fair public scrutiny and independent dam assessment. Thus, the public is left to trust that tailings dams are safely constructed and maintained and that adequate plans for emergencies are in place."

And to be clear, tar sands tailings dams haven't escaped problems. Three major accidents have been reported, all in the 1970s, due to factors such as slope instability and foundation weakness. However, there is no public information about these events or the volume of tailings that was released.

Tailings ponds are already leaking

While the public has little information about the risk of a breach, the regulation of tar-sands tailings dams is dismal. A 2008 study by Environmental Defence Canada, based on industry data, found that as much as 2.9 million gallons of water leaks from tar sands tailings ponds into the environment every day, with no enforcement by the government. New federal research by Environment Canada, released in February 2014, confirms that leaking tailings ponds are leaching into groundwater and then into the Athabasca river.

Even the weakest regulations on the books, designed to limit the volume of tailings waste, aren't enforced. There are news reports on how the tar sands industry is not complying with these regulations and Alberta regulators have announced they will not enforce the regulations first introduced in 2009.

Canadian authorities looking the other way

Perhaps most distressing is how authorities from the Canadian federal government treat the tar-sands tailings problem. A petition filed by NRDC and Environmental Defence Canada in 2010 with the Commission on Environmental Cooperation (CEC), a NAFTA oversight body, raised concerns about the leaking tailings ponds and the failure of federal government authorities to enforce its clean water laws. Recently, the CEC agreed to pursue an investigation, but in a shocking response, the Canadian government has not only refused to participate in the investigation but has announced it will fight to keep the investigation from happening.

And while the government has no plans to eliminate tailings from the tar sands production process, last year Alberta's premier traveled to Washington, D.C. to disingenuously claim that tailings dams would "disappear from Alberta's landscape in the near future."   It is no secret the Alberta government has failed to enforce its tailings regulations but its communication materials suggest they are enforcing the law. And despite clear evidence to the contrary, the Alberta government denies there is even a problem with leaking tailings ponds.

All of this leaves the public in both Canada and the United States with a strong impression that Albertan and federal Canadian regulators are, at best, ignoring the alarming growth of tailings waste and the fact that the ponds are leaking. This willful ignorance, coupled with the lack of public information about safety measures in place to prevent against a breach, does not inspire confidence that authorities are minding the store. It is in this atmosphere that the public has a right to demand information so they can learn about the risks of a catastrophic breach of a tar sands tailing dam and push for actions to prevent it from ever happening.'

This blog post was originally posted on Live Science.


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Michael BerndtsonAug 27 2014 10:31 AM

NRDC or the Canadian equivalent should continue to focus on this issue. It's may seem like a local environmental problem. It really will become a North American problem. And the world for that matter. We may have to pay for that cleanup one day.

When I think of tailing dams, I don't think of an inclosed API Separator. API or American Petroleum Institute separator is a tank that separates solids, heavy oil (maybe), light oil from the water phase. Usually for a refinery. A tailing dam pretty much is an earthen wall to trap of knockout rock and soil from water during mining operations. In Alberta, there's probably several liquid phases contained behind the dam, heavy oil, water and light oil. What's dissolved in the water at low concentrations can't be good. That water hopefully gets treated before flowing through or channeled around the dam.

All that processed bitumen from tar sands seems to be flowing to the PADD II refineries. Those would be refineries in the Midwest. Soon all that bitumen will flow to Texas and East Coast. That's without Keystone XL even being built.

A Proud CanadianAug 27 2014 08:14 PM

I knew that it was only a matter of time before you would go hyperbolic on this topic.
It is only natural that one mining company’s failure becomes a red alert for the oilsands. It is natural that of a massive worldwide use of tailings structures requires a focus on oilsands ponds only that have been in use for decades without even a hint of a possibility of a rumour of a whiff of a breach. It is natural not to write about these pond elsewhere in the world.
It is natural to write about the oilsands though for someone on the “Canada Project” …… if your funding source decrees it so. Come on Danielle…. Pembina Institute referencing Environmental defense selectively quoting Schindler. Etc… etc…..
I look forward to your colleagues reports from the Venezuela Project or the Saudi Project ….. or the Putin Project

A Proud CanadianAug 27 2014 08:19 PM

In what way are you paying for that cleanup? These ponds are integrated into full reclamation plans paid for by the operators.
Let me tell you what happens in a tailings pond……..
Originally, tailings were send to these large dam like structures to just sit. And slowly …. very slowly…… the fine silty material that suspends in the water, would eventually settle to the bottom. The “clear water” at the top of the pond would be re-used (offsetting river water). The problem with these ponds is that it takes long periods of time for the fine material to settle and free up the water. This is definitely a problem as it requires large areas for storage and extended durations where an operator needs to extract river water.
In terms of what happens to the hydrocarbons in these ponds….. most sink to the bottom during deposition. The bottom of the tailings pond becomes a sand/bitumen mixture (back to whence it came I suppose). Any light hydrocarbons in any watery phase are recycled back into the process within the free water. No water “flows through or around the dam”.
Now to the current day. Operators are preparing methods to deal with these silts/fines on a much more accelerated basis. Cyclones, Thickeners, Centrifuges, and other efforts are being put into place as we speak to deal with this. Water will be freed up much more quickly thus stopping the increase in tailings pond size as well as vastly reducing river water needs.
Danielle, if you are reading, you should inform readers on the requirements of Directive 74 (AER) and if you are in the loop at all, the upcoming (and much more restrictive) Tailings Management Framework, being prepared for later this year. Tell people what is actually being done.

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