Acid mine drainage – alternative water supply for fracking operations
Today we speak to Carolyn Kotsol, CEO and President of Winner Water Services, about water usage in hydraulic fracturing and how using purified water from abandoned mines, known as ‘acid mine drainage’ can have a positive environmental impact.
Monica Thomas (Shale Gas International): Winner Water Services takes acid mine drainage and purifies it to a degree where it can be used for hydraulic fracturing operations. So, to begin with: can you explain what acid mine drainage is? Where exactly does it come from?
Carolyn Kotsol (Winner Water Services): Acid mine drainage is from coalmines and other mining industries, some of these could be mines that have been closed for decades. After mines have been closed they still leach out components form the mine, these components could be sulphates or metals; iron, manganese, magnesium, aluminium.
All of the materials that leach out from those mines end up going into water streams as the earth produces. It’s in those water streams that we find what we call ‘acid mine drainage’, because it is a drain really, from these closed mines. It could be from active mines as well, but it’s primarily closed mines, where that water is secreting from the earth and it’s causing problems.
It contaminates aquatic systems, so the fish and turtles and other aquatic species have contaminated water around them, oxygen is no longer able to be in the water streams and those species are exposed to some danger because of it.
Another problem with acid mine drainage can be seen in streams as they are produced across the earth. It looks like they are heavily coloured, with orange or dark red material – that’s primarily iron – magnesium and aluminium can turn the area around the stream white, so you can see it as well. Some things you can’t see, like sulphates or the other metals, but we know it’s there and it’s causing problems to the aquatic species.
So that’s basically what acid mine drainage is, material that is excreting from old mines and causing these high metals and other materials to contaminate the water stream.
MT: And is it a particularly bad problem in Pennsylvania, or is it a problem that is more widespread?
CK: It’s really focused on the areas where mining was prevalent, so of course Pennsylvania, West Virginia, portions of Ohio, Kentucky, Virginia – the Appalachian region. But there is another area out west that also suffers from this, and it’s Colorado.
Now the mines out there they may not have been coalmines, they may have been gold or silver, or other metals that they were mining there. But those mines are still going to secrete a lot of the minerals from the earth, so Colorado, Idaho, Montana, in that region of the Rocky Mountains, they also see some acid mine drainage from the mines that were closed several decades ago.
MT: That seems like a big environmental problem, doesn’t it?
CK: Yes, it is a big environmental problem and what’s interesting as well is; in the Appalachian area they see a lot more rainfall than they do out in the western states, therefore what we see happening there is some of the acid mine drainage could be diluted down if you have a really wet spring or fall, or a lot of snowfall over wintertime. But when you go out west, where they struggle to get water, it becomes a different type of problem just because of the environmental precipitation. But it certainly is a widespread problem.
MT: So your company takes this highly-contaminated water and you purify it so it can be used in fracking. But fracking is – or is perceived to be at least – a very dirty operation. So one would be excused in thinking that if we’re going to pump all that water into the ground, it doesn’t really matter whether it’s clean or dirty. But this is not the case, is it?
CK: That’s a good question and I have a couple of points I’d like to make. First of all, in the Appalachian region, because of all this precipitation that comes down – specifically in Pennsylvania, the Marcellus, and even Utica – there are a lot of ponds, rivers, and lakes, with fresh water available for the shale gas industry.
That water can also be potable water, it can be used for human consumption. So where we come in, is we take this non-potable water, in fact it’s a contaminated water stream, and clean it up to a point to where the hydraulic fracturing industry would like to see it, and that’s sort of the second point.
The first point is that it’s an environmental benefit to re-use a non-potable, contaminated water stream that’s been cleaned up and purified for hydraulic fracturing, in lieu of using fresh water that could be used for potable sources.
The second point is; in the hydraulic fracturing industry, the drillers and the producers on the backend of the process have their own recipe of chemicals that they use to push down into the earth to extract the gas. It’s a proprietary mixture of chemicals that they use to optimise the efficiencies of the well.
With every recipe that these folks are using in the well, they like to have a “fresh” – and I use “fresh” in quotes there – water stream to make sure that it doesn’t add any more complexity to their recipe. With the chemicals they are using, they want to have a cleaner water stream, so they know that their mix of chemicals is still intact and will still produce the efficiency that they need to get out of that well.
So it’s important that we provide them with a water stream that doesn’t interfere with their chemicals, but we also want to be kind to the environment and provide them with a water stream that we’re not taking away from human consumption. We’re truly purifying a contaminated stream and purifying it to provide them with a cleaner water stream that they can use.