Before we dive into our story, we would like to make sure that all of us here are on the same page. We will often use the phrase “extreme resource extraction” – what do we mean by that?
Now I know that there is nothing more boring than a powerpoint presentation full of charts and graphs, so I promise this will be the only one… But this curve is vitally important to understanding what is going on all around the world today – this graph shows the “energy return on energy investment” from conventional oil extraction methods. Only about 50 years ago, 1 barrel of oil invested into extraction yielded about 100 barrels out in return. But people rapidly used up all the easily accessible stuff, and nowadays the number is somewhere closer to 1 to 5. As more accessible resources dry up, prices rise and methods formerly considered too expensive, too harmful, or too unpredictable become more and more appealing. A short-sighted gold rush mentality encourages rapid investment and expansion in new, untested technologies.
Tonight we will be focused on a trio of relatively new and very quickly growing industries that threaten the Great Lakes region – fracking, tar sands, and sulfide mining. Basically, these different forms of “extreme resource extraction” have three things in common. They are all ways of “scraping the bottom of the barrel” – getting very low-grade resources that were formerly considered unviable. They require high inputs – lots of energy in for relatively little energy out – and they are also very violent processes, using lots of explosives and harmful chemicals. And they all consume and permanently pollute very large amounts of water.
First we will take a look at horizontal hydraulic fracturing, what most people call “fracking.” Fracking is being used to extract oil or natural gas from shale deposits, where the fossil fuels exist in tiny pockets widely dispersed throughout the flaky sedimentary bedrock. Oil or gas shale exists in many places all around the world, including almost every Great Lakes state and province.
The first step is to drill a well, often about 2 miles deep, and then drill horizontally through the shale layer, up to 6 miles. Next, the bore-hole is coated with a cement well casing, usually about 1 inch thick. Then millions of gallons of water mixed with sand and a cocktail of chemicals including benzene, methanol, and other carcinogens are pumped into the well at great pressure to break the shale. Average water usage in one well-fracking is about 5 million gallons, but can vary widely – we heard about recent wells in Michigan which took over 35 million gallons to frack!
It takes an average of 400 truck trips to bring all this water, sand, and chemicals to and from each site. Here you can see trucks being used for another purpose as well – each one of these trucks has a huge diesel generator running for a week or two to power the well drilling.
When the high pressure water explodes out from a special pipe in the horizontal part and shatters the fragile shale, then the sand mixed in the fracking fluid keeps the cracks open so that oil or gas can escape. Generally about 30% of the injected fluids stay underground, while the rest comes spewing back up. One “drill pad” may include up to 10 wells, radiating out in all directions, and each well may be fracked multiple times. So we are talking about potentially hundreds of millions of gallons of water being consumed over the lifetime of each well site.
Waste water, which also includes high levels of radium, uranium, lead, and other toxins liberated from the bedrock, is left in tailings ponds near well sites, to evaporate, or it is pumped into old unused wells – out of sight, out of mind, apparently, but the process of force-injecting waste water into old wells has been causing earthquakes in Ohio, Texas, and Oklahoma!
Its not just water and fuel being wasted in large amounts. Fracking has created a huge demand for high-grade sand too. In the Driftless region of Southwest Wisconsin, where I am from, industrial sand strip-mining has moved in aggressively, and in a span of only 3 years, about 150 new giant sand mines have begun tearing apart fertile farmland!
Each well captures relatively little oil or gas – I have heard that most gas fracks arent even turning a profit! – and that means that companies are blanketing large areas with thousands of wells. Here is a photo from Colorado, which now has nearly 50,000 frack wells!
The average life of a frack well is less than 10 years, but they can cause permanent pollution if gas or fracking fluid escapes from leaky well casings and flows into aquifers or surface water. With so many wells being drilled so quickly, industry studies find that at least 6% of the cement well casings fail immediately, and a 60% failure rate at 30 years, and there are countless reports of accidental spills and leaks from trucks and tailings ponds.
Tar Sands are a type of low-grade resource that exist much closer to the surface. Tar sands are a mix of sand, clay, water, and bitumen, which is a very thick and sticky form of crude oil, when separated from the sand it has the consistency of cold molasses.
There is a huge tract of tar sands currently being mined in Alberta, Canada, and there are proposals to begin mining tar sands in Utah now as well.
About half of the extraction in Alberta is done with an “in situ” process which is similar to fracking in some ways – steam is injected into wells that run horizontally through the sediments, separating bitumen and bringing it to the top. The other half is done with open pit mining, like we see here. The forests are clearcut and topsoil is bulldozed away, then everything is excavated up to 200 ft deep.
These 400 ton dumptrucks are the size of a large house, and they are carrying away the land so rapidly that these mines can be seen from space!
Raw sand is taken to huge refineries nearby mine sites, and to separate bitumen from sand, once again a complex process requiring enormous amounts of water and chemicals and heat and electricity is used. To get one barrel of oil from the tar sands, energy equivalent to one third of a barrel of oil plus about three and a half barrels of water are consumed.
Waste water filled with chemicals, sand, and bitumen residue is deposited in tailings ponds lining the Athabasca river. Unlike most fracking tailings ponds, these pits are unlined, and it is estimated that about 2.5 million gallons of toxic slurry are leaching into the soil and the Athabasca River every day! And flowing downstream, poisoning first nations communities who live all around that area.
Separated bitumen is mixed with regular oil or natural gas to make “dilbit” – diluted bitumen – and then it is shipped by pipelines out to coastal areas where it will be further refined or exported. Tar sands extraction is far from the Great Lakes region, but pipelines run through every Great Lakes state and province, and many expansions are proposed. Many of these “expansions” simply mean getting permitted to pump more volume through already aging and leaking pipes, which means that leaks or spills could potentially threaten hundreds of communities and watersheds.
In port cities like Chicago and Detroit, people are also dealing with a toxic tar sands byproduct called petcoke. Petcoke is more like coal than oil, dry and dusty. It is much too dirty to be burned in power plants in the US, but it is being exported to other places like India or China. In the meantime, it is sitting in huge uncovered piles, blown by the wind and washed by the rain into rivers and nearby neighborhoods.
Lastly, we will look at Sulfide Metal Mining. “Sulfide minerals” are ancient layers of sedimentary rock that contain nearly every element in the periodic table, including a wide variety of metals, which are bonded with sulfur molecules. For example, pyrite or fools gold is the sulfide form of iron (FeS2). Sulfide minerals can also contain trace amounts of valuable metals like gold, silver, copper, nickel, platinum, chromium, or uranium. And we are talking about really small percentages here – nowadays an average gold mining operation takes out about 30 tons of rock to get one ounce of gold!
In most places, sulfide mineral layers are deep under many other layers, but in the Canadian Shield geologic area they are close to the surface.
Extraction starts when companies remove trees and topsoil, then use explosive charges to blast apart the rock.
The rock rubble is hauled off to processing plants where it is ground up into a very fine powder, and then mixed with water and chemicals and electricity to separate out the desired metals. Once again, this is an elaborate process – here you can see the huge scale of a taconite processing plant we saw in Northern Minnesota.
Once again, huge amounts of waste water and rock are left behind, this time they are full of sulfur and other undesirable and toxic metals like arsenic, cadmium, and lead. Exposure to air and water turns sulfur into sulfuric acid. This is called acid mine drainage. Sulfide mining tailings ponds are filled with extremely dangerous toxic waste – sulfuric acid is not only harmful in itself, it is also able to liberate heavy metals that are bonded in rocks and soil, so it accumulates more and more toxicity as it flows through a watershed or aquifer. This is a photo of nickel tailings in Sudbury, Ontario.
This is cyanide-laden run-off from a gold mine in British Columbia.
Taconite mining, which has been common around Lake Superior for many years, is similar to sulfide mining in some ways, different in others. Taconite is a generic name for any kind of rock that contains 10-20% iron. Taconite mining is similar because it involves extracting large amounts of rock, crushing it to fine powder, then separating iron with giant magnets. But most of the time, taconite mineral bodies are not sulfur-rich, so they dont have such high likelihoods of acid mine drainage. The company that is proposing the huge Penokee Hills taconite mine for northern Wisconsin has been insisting that this is not a sulfide mine, because the iron-bearing mineral body does not contain sulfur. However, there is a sulfide mineral body on top of it, which will have to be blasted and removed, so actually there will surely be acid mine drainage there as well.