PowerPoint Presentations

At the website http://www.ostrf.com/ are (or soon will be) PowerPoint presentations from the First International Oil Sands Tailings Conference, held in early December 2008 in Edmonton, Alberta. I recommend them to anyone interested in the history and development of mining and technology. Proceedings of the conference may also be obtained through the site.

What It’s All About

The soil that contains the oil is excavated and treated to recover the oil. Left behind are sands, silts, clays, and small amounts of oil. The clays cause the resulting mixture to behave like a fluid mud. The reason the mix behaves like a mud is that the clay particles are so small that electrostatic forces on the edges of the clay particles prevent the clay particles getting close together to form a solid that people can walk on. Much fundamental scientific investigation is going into understanding the chemistry and physics of these clay particles that prefer to remain alone and repulse fellow clay particles. The holy grail is a way to get the clay particles to stick together to form a solid that a little old lady in slippers could shuffle across.

Some ways of getting the mud to become a solid soil include squeezing the water out of the mud by applying pressure, spinning the mud to get centrifugal and centripetal forces to separate the clays, sands, and water, and adding chemicals to change the behavior of the repulsive clay particles. Every chemist has a better chemical to do this. And every equipment manufacturer has a better centrifuge or thickener to do the same. But it all costs money.

In the hot dry climates south of the equator, the miners discharge thin layers of mud-like tailings and let the sun dry the mass to create a surface you can walk on. But it is too cold in Northern Alberta for this to be effective. Granted freezing and thawingare partially effective in dewatering and consolidating the muds, but you need large areas and patience for this to be the total solution.

If you can build a water-retaining dike and let time and gravity induce drainage and consolidation of the tailings, you might succeed in dewatering the mud. Now the Spanish consider 2,000 years a drop in the bucket of time. After all they will remind you that 2,000 years ago a Spaniard was Emperor of Rome. But to the impatient North American, 200 years is all of history, and 20 years a life-time career. So waiting 2,000 years for time and gravity to turn the mud to solid soil is just not acceptable to the impatient.

The Alberta regulators, responding to public impatience for quick solutions, have mandated that after one year, newly placed tailings should have a strength of 5 kPa and should support our peripatetic old lady shuffling along in her slippers over a vast landscape of oil sands tailings. Hence the research and this conference.

The oil sands operators are advancing. First they have pinned the science of the clays. Then they have pinned the chemistry. Now they are researching the equipment that dewaters by stressing, spinning, and swirling the muds. Next they will master the intricacies of discharging the muds from pipelines behind dikes to form deposits that can be trafficked after areasonable period of patience.

Geotechnical Engineering Perspectives

As a geotechnical engineer, my instinct is to go with Ed McRoberts of AMEC Earth & Environmental whotells how the geotechnical engineer has always sought to build water-retaining structures toimpoundthe essentially-fluid tailings. And a fine job he andhis fellow engineers have done over the years. I liked his succession of slides showing how the cross section of thewater-retainingdike haschanged over the fifty years of oil sands mining from the years when legendary Canadian names like Hardy designed the embankments to the current day when he is in the lead.

The presentations from Suncor, Syncrude, Horizon Oil Sands, and Albion amply demonstrate the progression of oil sands deposition practice from putting the clay-dominated tailings into water-retaining structures, through adding gypsum to make the tailings behave like sands, to using the separate sand and clay streams to form impoundments, to mixing the sand and clay with sophisticated mechanical equipment to prevent segregation on deposition and so avoid the perils of a segregated mass. This is the story of the dominance of the clay mineralogists and chemists on the practice of tailings deposition.

The tension between a geotechnically-dominated perspective and an “awesome floc” dominated perspective persists. Not once did I hear about the old-fashioned geotechnical properties of the tailings; such things as permeability, shear strength, or consolidation coefficients. Yet I suspect it is these old fashioned soil mechanics things that will control the closure, reclamation, and long-term behavior of the tailings and their impoundments. It is just like the early days on the Uranium Mill Tailings Remediation Project when the only issue was the radioactivity of the tailings. It took a while to focus on the long-term soil mechanics issues that dominated a 1,000-year closure criterion.

Theminor side-shows cropped up in the Q&A session.The first was the issue of why no cooperation between the major players in oil sands tailings disposal. The answer was that there is cooperation, there are no patents, and yet an admission that corporate knowledge belongs to the shareholders, not the public. Personally I see this as a fascinating instance of the tension between the advantages and disadvantages of competition versus cooperation. As one speaker put it: “Together we stand; together we fall. In New York they do not even know there are different companies involved.”

There are differences of soil, chemistry, and process at each different plant. There are different corporate histories of the development of tailings disposal technology: Suncor has been at it for fifty years, some have yet to discharge an ounce of tailings. There are young men scorning the old ways. There are old men building on the best of the past. And there are common pressures from the public and the regulators. It will take a master historian to tease apart the multiple threads that dominate the story of oil sands tailings disposal.

So before you go about criticizing the oil sands for their scale and seepage, take a look at the OSTRF site, read the papers by those who spend their working days seeking to improve practice, deal with multiple divergent stakeholders, and plot a course through the chemistry and physics of clay and soil mechanics, and pause to wonder that so much has been achieved and that such minds are at work.

And if reading the papers does not convince you, then take a drive from the Edmonton airport out to the Mayfield Hotel and contemplate the vast scale of houses and shops and roads that utterly dwarfeven the largest oil sand mine, and reflect that in the goodness of time the impoundments will be reclaimed, but the heavily mortgaged sprawl of ugly houses will remain.

ERCB Regulations

Richard Houlihan of the Alberta Energy Resource Conservation Board (ERCB) talked about proposed new ERCB regulations for oil sands tailings disposal.

The technical paper that accompanies Houlihan’s talk says this about the performance criteria the ERCB will demand be met (I quote it all as the implications are many millions of dollars; but I confess that in spite of my LLB I cannot make head or tail of this prose):

The performance criterion for fluid tailings reduction is based on fines captured in the Dedicated Disposal Areas (DDAs). Fines are defined as mineral solids with particle sizes equal to or less than 44 micrometers. The criterion establishes a minimum mass of dry fines in the oil sands feed expressed as a percentage of total fines in feed that must report to the DDAs. This requirement applies to a one-year period between surveys and phased as follows:

  • 20 percent from July 1, 2010 to June 30, 2011
  • 30 percent from July 1, 2012 to June 30, 2012
  • 50 percent from July 1, 2012 to June 30, 2013 and annually thereafter. The above requirements are for fines deposited in DDAs. The fines captured in DDAs must be in addition to the fines captured currently in hydraulically placed dikes and beaches.

DDAs must be formed in a manner that ensures trafficable deposits. The performance criteria are based on the strength of the deposit. The following criteria must be achieved annually:

  • Minimum undrained shear strength of 5 kilopascals (kPa) for the material deposited in the previous year.
  • Removal or remediation of material deposited in the previous year that does not meet the 5 kPa requirement
  • Deposit ready for reclamation within five years after active deposition has ceased. The deposit will have the strength, stability, and structure necessary to establish a trafficable surface. The surface must have minimum undrained shear strength of 10 kPa.

In summary, I suppose this says that you must entrain up to fifty percent of the clays in the sands and the resultant mass must get stronger and stronger as the days pass.

New regulations that have a profound impact on a major industry are inevitably controversial. But there appears to be no controversy arising from the oil sands companies. In the Q&A session, oil sands industry representatives generally complimented Houlihan for a thoughtful and reflective presentation and said they believed they could comply with the regulations. That is good, or is it?

Some industry watchers have noted that the proposed new regulations have been long in coming, and may not be stringent enough. But that is a standard refrain from the negative-nabobs, so we need not delay to consider their concerns.

Houlihan rightly recognized that there is a long history of oil sands tailings deposition and not all of it may have been good. But he emphasized that the task ahead of us it to make things better, not ruminate too much on the past.

In spite of Houlihan’s sober and thoughtful presentation and the positive industry response, I confess to a slight unease about the proposed regulations. Let me explain why.

A good law, rule, or regulation (I shall use the word regulation only in the remainder of this posting) is easy to understand and enforce. Even better is a regulation that it does not have to be enforced: people simply act in accordance with the spirit and letter of the regulation because it is so obviously the sensible thing to do.

A good regulation sets noble and achievable goals and leaves it to the person complying with the regulation to find the best way to achieve the goals inherent in the regulation.

Regulations may be prescriptive or performance-based. For example, a prescriptive regulation tells you to put three-feet of clay with a hydraulic conductivity of less than 10-6 cm/sec as the liner beneath your impoundment. By comparison, a performance-based regulation says: operate the impoundment so that is does not affect water quality---you prove to us that you are protecting groundwater quality.

Prescriptive regulations inevitably fail to achieve the desired outcome. Prescriptive regulations fail because they stifle human ingenuity and technical innovation. It’s like the failure of five-year plans to stimulate a communist economy.

At the worst a prescriptive regulation eliminates innovation and stops progress leading to a net loss for stakeholders and the environment.

My favourite example of a good goal-base regulation (actually a law of the United States government) is the one that governed the Uranium Mill Tailings Remediation (UMTRA) Project. It was pretty simple. It stated: close those 24 uranium mill tailings piles so that they are stable for 1,000 years to the extent reasonably achievable, and at any rate for 200 years.

On the basis of that simple directive, we advanced technology, improved engineering practice, remediated the sites, and got almost everybody to support what we did.

A good example of a bad regulation is the one foisted on the landfill industry many years ago. The regulation mandated a liner of clay with a specified thickness and permeability. In places where there was no clay, this caused great confusion. In practice, after a lot of to-and-fro, the industry was allowed to use geosynthetics including geomembranes, geosynthetic-clay-layers, and other innovative, technically sound, and cost-effect components. And there was far better groundwater as a result.

Now let us look at just one part of the proposed ERCB regulation for oil sands tailings. They say that within one year of placement the tailings should have a strength greater than 5 kPa and ultimately the strength should be greater than 10 kPa. And if the strength falls below those limits you will scoop them up, take them back to the plant, and rework them.

Let us leave aside the terminal ambiguity of how you measure the strength (I doubt a geotechnical engineer was involved in setting this vague requirement.) Fact is the five and ten kilopascal requirements are lifted from a technical paper by Jakubick, A., McKenna, G., and Robertson, A. (2003): Stabilisation of Tailings Deposits: International Experience. Proceedings of Mining and the Environment III, Sudbury, Ontario, Canada, 25-28 May, 2003.

Read this paper and you quickly see that it has nothing to do with oil sands tailings. It is all about uranium mill tailings stabilization in East Germany. And sadly it is based on out-of-date technology, now superseded by the vastly more powerful computer code FLAC. This is an egregious example of inappropriate engineering and regulation.

I admit that the underlying objective of the proposed ERCB regulations is noble: do not leave behind an oil sands tailings impoundment that consists of a well-engineered earth dike holding back fluid tailings. Presumably the regulators who wrote this proposed regulation want to avoid dike failure and flow of the impounded fluid-like tailings down the Athabasca River any time in the perpetual future.

Which make you wonder why they did not simply say so? They could have written the new regulation thus:

Design, build, operate, and close oil sands tailings impoundments so that they do not breach and the contents do not flow out for at least 10,000 years to the extent reasonably achievable and at any rate for 2,000 years.

There are many ways to achieve this and hence protect human health and the environment. Although I admit, the industry would probably not fall in line behind the regulators at the thought of providing long-term impoundment integrity. Much easier to support 5 and 10, ambiguous as they are.

On a small scale, tailings with a strength of five to ten kilopascals have been placed successfully for over twenty years at the Greens Creek mine on Admiralty Island in Alaska. They simply filter press the tailings, add a bit of cement, and place the result in a solid pile. In effect this is what the ERCB wants and is demanding. Witness the many presentations at the conference on ways to press, spin, swirl, and chemically amend the mud-like tailings to make the awesome floc. I propose a field trip to Juneau and Hawk Inlet.

With all due respect to the scientists and engineers who are working so hard and presenting papers at the conference, it is going to take many dollars and much energy to achieve a comparable result in Fort McMurray.

A solid with an ill-defined strength may still seep, leak, liquefy, flow, or pollute. A pile of weak solids is still vulnerable to geomorphic forces. It is still liable to precipitation infiltration, throughflow, and exfiltration to the groundwater and surface waters.

As Gord McKenna said in his presentation to the conference attendees, the oil sands industry is light-years ahead of the regulators in seeking to achieve cost-effective, practical, and safe closure of the oil sands tailings impoundments. And the industry remains ahead of the regulators if these proposed regulations are any indication. The narrow focus of the proposed ERC regulations ignore issues the industry is facing and stakeholders are interested in; these issues include geomorphic stability, infiltration, exfiltration, constituent migration, landscaping, and support of vegetation.

It is sad to think of the energy and effort that will go into fighting about mud strength, fighting about CPT strength versus shear vane strength, total versus effective strength, pore pressure buildup and dissipation, strain rates and the normal distribution curve versus beta tail of field data. As a lawyer, I would challenge the proposed regulations on the basis that they are terminally ambiguous and un-interpretable.

That said, I recognize that most likely somewhere there is a young scientist, a bright engineer, an innovative manufacturer, or an avid supplier of chemicals with the solution to turning mud into rock up their sleeve. We must grant that these regulations are spurring vast quantities of research by eager manufacturers to come up with a better cyclone, a more effective thickener, or a floc-producing polymer. But if I am wrong and the solution to turning mud into rock is not just over the horizon, then these regulations are about to impose impossible costs and the death sentence on many an oil sand miner. As one of the regulators I spoke to during the conference said: “If they cannot do what we demand, or cannot afford it, then they had better not mine.”

These regulations ignore the benefits of in-pit disposal as compared to above-grade impoundment. The regulations ignore the potentials of a water cover, the opportunities inherent in geosynthetics, and the genius of engineered dike designers.

There is another aspect of the regulations that demands comment. There is the strange requirement that a specified percentage of the clay-sized tailings be entrained in the sands or awesome flocs. The presentation by Houlihan left me confused about just how much clay entrainment is required. In the Q&A period he equivocated on the issue. I would have thought it better to get the clay out of the sand rather than legislate to foul up the sand with the clay. Maybe I just have it all inside-out and backwards. And the oil sands industry sees this topsy-turvy regulation as a glorious opportunity to drive a Moxie through the holes in the logic and prose.

I admit to a certain absence of knowledge about oil sands tailings. I have not devoted a career to them. I am not privy to the insider lingo and quiet interactions that occur in cold climates. So I say at the outset sorry to any I may offend with these remarks. I am honoured to be in a position to comment and assure you my intention is to get folk thinking so that a better regulation is imposed. I aim for a simple, clear, regulation that is easy to follow, implement, and which truly leads to long-term protection of human health and the environment. So if you must respond and criticize me, do it only on the basis that the current regulations will lead to geomorphically stable, unleaking, vegetated landscape forms that will never flow down the Athabasca River. Whereas my approach would not achieve as fine a result.

Finally Jobs

The conference is over and the scientists and engineers are back to solving real-time problems. They are at work; the question is do they have work and a job for you?

Turning to CareerMine,I findnineteen jobs for the keywords oil sands tailings. There are positions advertised with Suncore, Syncrude, Shell, and more. The links are to the job descriptions. With time the jobs will be filled and the links broken, so please be patient if you come along in the future and find these jobs taken—presumably there will be othersonthe CareerMine Site.

One lady who will soon be at work in the oil sands tailings industryis Heather Kaminsky who made a great presentation and told us she is looking for a job. At this link is her thesis. I bet she will soon be snapped up inthe industry. Even if you cannot employ her, take a look at the profundity of her thesis; it provides great insight into current progress on oil sands tailings.

There are reports of a slow-down in oil sands work. And that is probably true for the start-up of new projects. But the tailings continue to come and the ERCB will continue to demand more and more and quicker clean-up, closure, remediation, and reclamation. Engineers will continue to be in high demand to do this work.

During the conference, folk I chatted to said the slow down provides and opportunity for welcome relief. One newspaper captures the reason why a slowdown is not all bad:

Project costs skyrocketed, infrastructure pressures soared, labour shortages were rampant, worker health/safety issues mushroomed, housing costs went through the roof, and overpaid twenty-somethings spent like drunken sailors.

Although I cannot see what is wrong with being an overpaid twenty-something spending like a drunken sailor. If only! Those moralists!

Seriously, now is a great time to consider one of those career changing moves. And if you are ready for minus forty as youplace tailings with a strength of 5 kPa, seek out the jobs that are there in oil sands tailings.

And While We’re in the Conference

During a Q&A session at the First International Oil Sands Tailings Conference currently underway in Edmonton, somebody asked Ed McRoberts of AMEC “Please comment on seepage and leakage from the tailings impoundments.” This morning the Globe and Mail wrote about a report from Environmental Defense that states that leakage from the oil sands tailings impoundments is estimated to be about 11 million liters a day.

Ed McRoberts answered most professionally that as a geotechnical engineer he controlled seepage from the impoundments so that the seepage does not affect the stability of the embankments and dikes impounding the tailings and entrained water. But he noted that he could not comment on leakage, as that is an issue for groundwater hydrologists. So far, so good.

As I wished to leave Edmonton unscathed, I too, as a geotechnical engineer, refrain from comment on leakage from oil sands tailings impoundments. But before anybody gets hot and bothered about leakage from a tailings impoundment, I urge them to read the many reports on leakage from the Uranium Mill Tailings piles that we remediated and closed in the early 1990s. The reports are readily available on the U.S. Department of Energy’s UMTRA website.

What it all boils down to is that gravity will make entrained tailings waters leak downwards in the fullness of time, unless you have a perfect liner beneath the tailings. And such exfiltrating water, as I prefer to call it in the interests of technical precision, will move on downwards to the groundwater and, depending on the topography, to surface waters. But if these groundwaters and surface waters are already affected by the radioactivity already in the ground and its waters, then in reality there is no detrimental impact.

Regulations that governed UMTRA demanded that we limit resultant changes in groundwater constituent concentrations to less than background or less than pre-set maximum concentration limits. Those regulations recognized the obvious fact that if you seek to walk away from the reclaimed tailings impoundment and be sure it will perform as designed in the long term, you do not put a liner beneath the tailings, for no liner can be relied on and it only serves to direct tailings exfiltration to an outlet point where you will have to collect it and treat it in perpetuity.

In the long term, the only way to limit exfiltration from tailings is to limit infiltration. And that can only be done with a cover, a cover that limits infiltration to such an extent that the resulting exfiltration does not result in an exceedance of background water quality or pre-set maximum concentration limits.

Thus, I submit the issue is not the quantity of water that exfiltrates. The issue is the impact of the exfiltrating leakage on groundwater and surface water quality. So before you go getting hot and bothered, I plead that we get the facts and adjudicate the issue in reasonable technical and scientific terms. More screaming about filling Toronto’s Rogers Center stadium every year with leakage from the oil sand tailings impoundments (as the Globe and Mail does) is silly, irresponsible, incendiary, and plain bad journalism.

I have not read the report as I cannot find a Google link to the report. If you can direct me, I will read it and undertake to comment on its veracity, accuracy, and relevance to more screaming and shouting.

PS. An update. Here is the link to the report. I have read it, and am no more informed than I was before. I grew to maturity under the scrutiny of the Nuclear Regulatory Agency (NRC) inthe United States and learned early that the U.S. Environmental Protection Agency (EPA) has teeth and uses them. Both have lapsed, but I suspect their response to this issue would have been different. But then Canada is a small country of rugged individuals living in a harsh climate. Maybe they just do things differently and are proud of it.