Tailings Ponds
It happened early on Monday 4th August. The tailings pond dam at the Mount Polley Mine in central British Columbia gave way. Ten million cubic meters of contaminated water and 4.5 million cubic meters of metals-laden sands and silts washed out into Hazeltine Creek, the outlet for Polley Lake. Hazeltine Creek flows southeast into nearby Quesnel Lake and then through Caribou Creek and on to the Fraser River. The contaminated sands and silts, together with debris scoured out of Hazeltine Creek plugged Polley Lake which rose 1.5 meters behind the unstable, and likely temporary plug. Most of the sands and debris ended up in Quesnel Lake where another large debris field is evident. Timber and other debris ripped from the banks of the Hazeltine Creek was floating about in Quesnel Lake as giant islands and for a time there was concern that one of these would ram into and demolish the only road bridge connecting the small town of Lively to the outside world.
Breached dam of the Mount Polley mine tailings pond and the path of destruction down to Hazeltine Creek and Polley Lake. Image © CBC
The tailings pond was about 4 x 4 km in area, a relatively big one. (If the 10 + 4.5 million cubic meters of water and sediments released were giant sugar cubes or Lego blocks they would form a rectangular stack, 100 meters by 100 meters at its base, and soaring nearly 1.5 km high, three times the height of Toronto’s CN Tower or more than 1.5 times the height of the Burj Khalifa.) Tailings ponds are the preferred method for handling mining wastes and the wastes from use of coal, and they do fail from time to time. In Our Dying Planet I wrote of the failure of a containment pond for fly ash generated at the Kingston Fossil Plant, a giant coal-powered electricity generating station near Knoxville, Tennessee. This 4 million cubic meter spill was less than a third the size of the failure at Polley Lake. Of course, the tailings lakes being used in Alberta’s tar sands operations dwarf even Mount Polley; the Pembina Institute reports that 173 km2 of Alberta, an area half again as large as the city of Vancouver, is already covered by tailings lakes, that 25 thousand cubic meters of tailings waste is being produced each day, and that the expected total of contained tailings from tar sands operations will reach 1.3 billion cubic meters by 2060.
Fortunately, it now appears that the water from the Mount Polley tailings pond was relatively free of contaminants although the sediments are likely to include nickel, arsenic, lead and copper. Water samples from Polley and Quesnel Lakes appear safe to drink although a drinking water ban still remains in effect. The contaminant loads in the sediments, however, may be a bigger problem, and cleaning them up will take some time. Water is now being pumped from Polley Lake into Hazeltine Creek to minimize the risk of an uncontrolled rupture of the plug of contaminated sediments and further damage downstream. Some water continues to flow from the tailings pond although the mine staff are working hard to put a temporary dam in place. The mine is in a remote part of the province, so most of the damage that has been done has not affected infrastructure or communities.
Troublesome Externalities
Still, this failure must cause us to think of the many risks that the mammoth scale of resource extraction industries now imposes on the environment and on people. Back when mines were small holes that went deep underground, back when dump trucks stood only three times as tall as a man and carried modest loads, back when tar sands were worthless because we did not have the technology or the capital investment needed to mine them, our impacts on the environment were similarly modest. But we are not back there anymore. Our much greater ability to change the landscape has led to ever grander projects, but we continue to think of environmental damage as something we can repair after the fact if necessary, rather than as something we should absolutely minimize in the first place. We think this way because environmental degradation or damage is just one of those negative externalities that do not enter into the economic assessment of the feasibility of a project. Sure, we have progressed from the old days when rape of the environment, with no effort to minimize damage or undertake any remediation, was the usual approach in all resource extraction industries. Now there is lip-service to the idea that minimizing environmental damage, and repair of any damage caused, should be the norm for all extractive industries – fisheries, forestry, and all types of mining are all managed with regulations that are intended to achieve sustainability (in the case of fisheries and forestry), and avoid or remediate any collateral environmental damage. Industry spends money to comply with the regulations, and some responsible corporations even go beyond the requirements of the regulations in order to more fully avoid environmental damage. But most corporations do their best to minimize these expenses because there is no payback to investors when the extractive operation ends if the environment is successfully put back together. If they do the bare minimum and walk away leaving something less than perfect behind, their investors are not unhappy.
Tepid Regulations
In situations where a major resource extraction operation, or a set of smaller nearby operations, comes to dominate the economic activity in a region, the economic power of the industry is such that it can influence government to minimize regulations, turn a blind eye, or, in other ways, let the industry get by with less effort to minimize or to remediate environmental damage. This is so because governments, the ultimate regulators, also tend to see environment as an externality – they understand the economic (and tax revenue) benefits of profitable industry that employs people far better than the intrinsic but often intangible, and certainly non-taxable, benefits of a healthy, sustainably managed environment. Environment comes second, if it even comes into consideration at all.
This certainly seems to be the case in Alberta’s tar sands district, where the enthusiasm of both provincial and national governments for an expansion of the industry seems to have led to minimal resource rents (Alberta), overly favorable taxation policies for the industry (national), weak regulations (Alberta), lack of enforcement (both), and perennial delays in putting additional or replacement tougher regulations in place (both). This overly compliant attitude by both governments has surely been encouraged by the Canadian Association of Petroleum Producers (CAPP), and individual operators, all of which have ample funds to spend in persuading government regulators to go easy, to go slow, and to give them yet more time to comply. This is all perfectly legal, but it is what happens when the foxes (the mining operators) are helping the farmers (the governments) look after the hen house (the environment).
Tailings lakes in Alberta’s tar sands district. Photo © Jeff McIntosh/Associated Press
In the tar sands district, there are enormous quantities of water being permanently contaminated through use in bitumen extraction. These are stored permanently in tailings lakes, because there is no current technology to clean them up at reasonable cost. This water is effectively being withdrawn permanently from the hydrological cycle, with no evident thought concerning the availability of water in that relatively arid region, or the impacts of those withdrawals on the environment. The Pembina Institute reports that about 11 thousand cubic meters of contaminated water are leaching from tar sands tailings lakes into waterways and groundwater every day. There is solid evidence of pollution damaging to fish and wildlife downstream. The lakes do not appear to be becoming clean by themselves, and the possibility of a tailings lake breach is a continuing possibility (and these tailings are dirty). What future problems for ourselves are we building in northern Alberta?
Tipping Points
One of the over-used phrases when discussing the environmental crisis is ‘tipping point.’ Recognition of the fact that environmental responses to stressors are rarely linear and sometimes rapid, leads naturally to a concern that as we continue to stress the environment, we must anticipate some unexpected, rapid, and perhaps consequential responses. The most frightening ‘tipping point’ in my view is what James Hansen calls ‘runaway climate change’. This is a situation that could arise if we push global temperature high enough to trigger several plausible positive feedback mechanisms that would then essentially take over and continually escalate the rate of warming no matter how much we reduce our own contributions of greenhouse gases. Potential positive feedback mechanisms include the melting of Arctic sea ice, the thawing of permafrost, and the melting of methane clathrates. Melting of the sea ice leaves the Arctic Ocean darker (less reflective) and capable of absorbing (as heat) more of the sunlight that impinges on it. As more ice melts, the rate of warming increases. This is already happening. Thawing of permafrost has the potential to release large quantities of trapped methane (a potent greenhouse gas) formed from decomposition of organic material in the frozen soils. This is starting to happen. Melting of methane clathrates will release more methane, and will happen when the oceans warm sufficiently. There are vast quantities of methane clathrates in the deep ocean and in subsea sediments. Remember the difficulties BP had in capping the Deepwater Horizon blowout. One early attempt with a large steel cone that was to be positioned over the well to funnel the emerging oil into a pipe to the surface failed dismally when methane in the emerging stream of oil combined with seawater to form clathrates which attached to its inner surfaces, plugging its narrow opening to the pipe, and causing the cone to be pushed away by the emerging oil.
Putting aside ‘runaway climate change’ as simply too awful to contemplate for very long, there remain a number of other potential ‘tipping points’ as nature responds to our meddling. The losses of insect pollinators due to our careless uses of pesticides and other chemicals are already having impacts on crop yields, but a tipping point in which widespread crop failure suddenly results is not far-fetched. Unexpected links between climate and insect-borne pathogens might lead to a sudden expansion to new regions of serious diseases like malaria. In much the same way, warming in British Columbia has already permitted a massive northern expansion and early incursions across the Rockies into northern Alberta by the mountain pine beetle resulting in large and growing losses in the BC forestry industry. Coinciding warming and shifts in location, timing and extent of rainfall have already led to severe droughts and floods in many parts of the world, but tipping into a long-term change in regional climate with severe consequences for food production or human health will likely occur and, because of the natural variability of weather, will not be recognized until some years after it happens. Has this already happened in the US Southwest or in western Australia?
Hidden complexity when several factors act together to stress a population
Most insidious of all are the tipping points that occur when seemingly unrelated impacts combine to lessen the chance of an ecological system being able to sustain itself. Some of these are surely already playing out in the oceans, but we are seeing only glimpses of what is going on. As an example of the potential complexity, consider the production of any fishery species. The production of young is a vital task for every population if it is to persist, and heavily fished populations are already stressed by being less abundant than before, and made up of younger organisms. Each individual may have, at best, only one opportunity to reproduce, while its ancestors lived long enough to reproduce in multiple years. Indeed, in the Pacific bluefin tuna, a heavily overfished species, the average individual is caught before it even reaches maturity, yet its ancestors, prior to overfishing, were living 15 years and reaching maturity at five years of age. Thus, overfishing both reduces the number of animals available to spawn, and reduces the number of chances to reproduce by each individual.
While this may not seem very important, limiting the number of chances to reproduce limits the overall total number of offspring that can be produced by each parent, and for organisms like fish that have very high (close to 100%) and very variable mortality in the first few days or weeks after hatching, that reduction in number of chances to reproduce can greatly limit the chance of a fish to get to be a successful parent at all. (It’s a bit like throwing a pair of dice – if you have only one or two chances, the likelihood of throwing a pair of sixes is small, but if you get to throw them 15 or 20 times the odds are much more in your favor for at least one pair of sixes. Think of a fish successfully reproducing as being like you throwing a pair of sixes.)
The typically high and variable mortality of newly hatched and older juvenile fishes is due to a number of factors including the availability of food and how fast they can grow. If there is plenty of food, they will grow faster, become better able to avoid being eaten themselves, and perhaps grow to adulthood. If food is scarce, they will grow slowly if at all, and may starve if not consumed themselves. Either way far fewer of the young fish get to grow up. If the water is warmer, that may increase growth rates directly, but only if food is available. Given this kind of a production system, an adult fish may well need more than one or two chances to reproduce to have any chance of producing young that reach adulthood themselves. This is so despite the fact that fish typically shed thousands of eggs at a time – thousands of eggs, of which nearly 100% usually die before reaching adulthood.
Now consider the prey species consumed by the young hatchlings. These tiny planktonic species must be available to be consumed at the time and place that young fish are present. But their own growth, survival and reproductive success is affected by the environment too. To the direct effects on survival and growth of these small prey species due to warming, or ocean acidification, add in the indirect effects of melting sea ice and glaciers which alter ocean circulation, transporting populations of plankton along different paths than they travelled before. All these factors together act to make the prey more abundant, less abundant, or even absent from a particular location in a particular year. Suddenly, juvenile fish are produced at a time and place that does not coincide with abundant prey to eat. The result is a reproductive failure by the population that year.
Have this happen in just two or three years in a row and that population will decline far more rapidly than would be expected based on overfishing alone (and also far more rapidly than it would if climate change was occurring but the fishery population was not being heavily fished). Mostly we find out about failed reproduction only after the fact, when the new individuals would be large enough to start being caught. Only there aren’t any new individuals. Only rarely do we know the full reasons for why the failure occurred.
Figure 5 from MacKenzie et al 2007 showing the complex network of effects of climate change on a) reproductive success, and b) growth in three fishery species: cod, sprat and herring. Climate, by affecting salinity (S), oxygen content (O2) and water temperature (T) has both direct effects (solid arrows) and indirect effects (dashed arrows) on each species, and the pattern of effects on reproduction differs from that on growth. Figure © Global Change Biology
A number of recent reproductive failures of fishery species have been attributed to an absence of the usual prey species (or a shift in their distribution away from where the hatchlings are – which amounts to the same thing). In 2007, Brian MacKenzie and three colleagues, all from Danish research institutions, published a review of impacts of climate change on Baltic Sea fisheries, in the journal Global Change Biology. They showed complex direct and indirect effects of climate-induced changes in the environment (temperature, salinity, oxygen content) on cod, herring and sprat and on the copepod prey species used by their juveniles. That same year, in Fisheries Oceanography, Thomas Brunel and Jean Boucher of IFREMER, France, published a look at long-term trends in reproductive success of fishery species across the northeast Atlantic. They found that ten populations of cod, plaice, whiting and herring showed substantial declines over the period 1970-2000. These were strongly correlated with warming of ocean waters, however the details varied greatly among populations and species. In some, overfishing had a major impact on population size before climate effects on reproductive success began to add to the decline; in others effects on reproduction were paramount. The overall message from such studies is that the success of a fishery population, and hence its availability for capture, depends on a number of different, direct or indirect impacts that include complex effects of climate change as well as impacts from fishing.
Never mind the continued production of a fishery species. Consider the plight of coral reefs around the world. If ever there was a good example of a tipping point, this is it. Reefs have been impacted by humans for many years, through overfishing, pollution, and physical destruction either deliberately to blast out channels or harvest limestone for building purposes, or inadvertently through inappropriate coastal development that lowers water quality, increases turbidity or simply buries living reefs in fine silt. Reefs have also suffered for years. Now, with added pressures due to warming and ocean acidification, and continued overfishing, pollution and physical destruction, reefs in many locations are deteriorating rapidly – a classic tipping point brought about by the synergistic action of multiple stressors each of which might have been far less harmful if it had acted alone.
A coral reef in healthy condition – the way they are supposed to look. Photo © R. Steneck
Tipping Points in the Tar sands?
Still, let’s struggle back onto dry land, because there is a reason I brought up tipping points. I believe our relatively new ability to embark on giant projects causing major changes to environment, even without unplanned events like tailings pond failures, is setting us up for a variety of tipping points in the near future. The tar sands operations in Alberta certainly constitute such a giant project.
There has been a tendency in the long-running debate over the tar sands to deal with issues one at a time. This mirrors the practice of government to evaluate and approve new tar sands projects one at a time. Given the scale of the tar sands industry, and its potential scale in the future if it expands as proponents and governments want, it makes sense to look at all the issues surrounding this industry together – instead of a series of separate potential environmental problems, there is a set of interacting, possibly synergistic problems that are likely to cause unacceptable environmental change. Let’s build a list:
- While the products refined from tar sands bitumen yield essentially the same CO2 emissions as those obtained from conventional oil, extracting and refining the bitumen costs about three times the amount of energy (= three times the CO2 emissions).
- Much of the energy used to produce the bitumen and upgrade it (make it liquid) for transport comes from burning natural gas, the least polluting of the fossil fuels – good fuel is burned to produce environmentally poor fuel, sort of like using gold to produce lead.
- The current scale, and the planned expansion of the tar sands operations are such that executing these plans makes it impossible for Canada to reduce its national CO2 emissions, no matter what adjustments are made in other parts of the economy. Current estimates suggest Canadian emissions will still be higher than 1990 levels in 2020. This puts Canada in an impossible position with respect to other nations, a position which will complicate international relations in ways that are unclear.
- Tar sands production is currently being constrained by the lack of capacity to transport the bitumen to refineries and markets. New pipelines and other transport capacity will boost refinery activity and production of refined products, with the result that availability of fuels will increase, prices will fall, and the North American addiction to gasoline and similar fuels will lead to increased use. We will be using more of the environmentally dirtiest oil, at the very time that nations should be weaning themselves off these products. A recent estimate in Nature Climate Change by Peter Erickson and Michael Lazarus of the Seattle-based Stockholm Environment Institute, suggests that approval of the Keystone XL pipeline would unlock about four times the CO2 pollution than in previous estimates, because of this effect on price and use. Yes, it would be worse to transition towards fuels derived from coal, but not much worse.
- Tar sands operations have already radically altered 280 km2 of the boreal forest, wetland and lake system of northern Alberta. If they expand as planned some 140,000 km2 of natural habitat could be disturbed. To date, reclamation of terrestrial habitats has been negligible, and techniques for reclaiming the wetlands do not exist. The United Nations Environment Program has included Alberta’s tar sands region among the 100 hotspots of environmental degradation worldwide, and Environment Canada has referred to the “staggering challenges for forest conservation and reclamation”.
- The extensive wetlands are an important sink for CO2, storing between 2000 and 6000 tonnes CO2 per hectare. Yet the approved reclamation plans call for most of these wetlands to become upland forests. A 2011 study by Rebecca Rooney and colleagues from University of Alberta, published in the Proceedings of the National Academy of Sciences (USA) reported that the net loss of wetlands from mining ventures approved to that time, is equivalent to the release of 41.8 to 173.4 million tonnes stored CO2, and the permanent loss of the capacity to store 21 to 26 thousand tonnes CO2 per year into the future.
- The Athabasca River, nearly 1500 km long, winds from its headwaters in the Columbia icefield in Jasper National Park, through the tar sands district and on to its delta into Lake Athabasca in Wood Buffalo National Park. It is also one of the longest undammed rivers in North America. Its water flow north from Lake Athabasca via the Slave River to Great Slave Lake and thence via the majestic Mackenzie River to the Arctic coast, a journey of about 4000 km. We all know what is happening to glaciers and the rivers they feed. The tar sands industry takes all its water from the Athabasca River or from groundwater sources in the basin. Current permits allow the taking of 349 million m3 water per year, an amount comparable to that used by a city of 2 million people. Unlike in most mining operations, that water is not used, cleaned and returned to the river. It’s used, dirtied, and stored forever in those giant tailings lakes. Flow in the river is already reaching critical low levels for fish populations during the winter months, and it is clear the river cannot supply the ever larger amounts of water a ramping up of tar sands production will demand. What will happen then? The governments have not yet introduced any regulations to limit operators access to water when river flow is low, and existing permits to draw water explicitly permit continued use so long as there is water available to use.
- The tailings lakes are already leaching contaminated waters into the Athabasca system. They are acutely toxic to animal life, containing naphthenic acids, for example, at concentrations 100 times greater than natural waters. And nobody knows how, if, or when these waters will be reclaimed.
- Air pollution is also a problem in Alberta’s tar sands paradise. Nitrous oxides, sulfur dioxide, volatile organic compounds and particulate matter are all emitted in large quantities from tar sands operations. Modelling of pollution from 6 operations (three in use and three more approved and under development) shows that they will collectively exceed provincial, national and international standards. Releases of benzene are also on the rise, from the burning of fossil fuels in operations and via evaporation from the tailings lakes.
- And then there are the pipelines, and the trains carrying explosive tar sands crude. Not only does construction of each pipeline snake across the countryside like a lengthening scar, the pipelines do rupture from time to time, and some, such as Northern Gateway will empty out into previously pristine coastal waters. To get the tar sands product to flow, it has to be diluted with natural gas condensate or similar fluids. Last year’s Lac Mégantic derailment and catastrophic fire showed what could happen to tar sands crude carried by train.
Put these ten issues together and it is clear – tar sand mining as practiced in Alberta is setting us up for any number of tipping points down the road. Meanwhile, our Harper government is spending a fortune of our money advertising the merits of the Keystone XL pipeline and Canada’s ethical oil on the walls of the Washington DC subway.
This used to be a productive, carbon sequestering environment of boreal forests and wetlands.
Photo © David Dodge, Pembina Institute.
Meanwhile, back at the Mount Polley Mine, the ban on use of water in Polley and Quesnel Lakes and Hazeltine and Caribou Creeks remains in effect, and Imperial Metals is still working to put temporary repairs in place at the tailings pond. A report in the Vancouver Sun suggests that Imperial Metals’ property and business interruption insurance ($15 million) may fall far short of the expected costs for clean-up, estimated to be in vicinity of $200 million. If that is not enough, production at the mine, now suspended, generates 83% of Imperial Metals’ revenue, and a class-action lawsuit by a group of investors in the company has already been filed. Needless to say, If the clean-up costs more than the deep pockets of Imperial Metals can provide, bankruptcy doesn’t magically repair the damaged environment. That troublesome externality will sit a permanent scar to join all those other scars in other places where industry made mistakes it could not repair.
How long will it take before we know the full extent of the damage? Let’s just observe that on 28th July 2014, over four years after the Deepwater Horizon blowout occurred, Charles Fisher of Penn State University, and 11 colleagues published a report in Proceedings of the National Academy of Sciences (USA) detailing their discovery of five, previously unknown, deep water coral reefs, two of which had been damaged by toxic substances from the blowout or from chemicals dispersed to control it. One of these reefs was 22 km southwest of the site and 1900 meters deep. That greatly expands the footprint of that disaster, both in distance and depth from previous estimates. The damage due to the Deepwater Horizon blowout continues today.
Humans are very powerful, and too often that power damages the fabric of the environment that ultimately sustains us. If there are tipping points in our future, and there probably are, we have put them there because we insist on seeing environmental damage as simply a troubling externality. It’s an externality that we need to internalize as quickly as we can.