We are still learning about what it means to inject millions of litres of water into the earth to unleash unconventional gas.
Here in Canada, a comprehensive, independent scientific report on water use in hydraulic fracturing (fracking) and other unconventional operations is due any day from the not-for-profit, respected Canadian Council of Academies.
Meanwhile, scattered information about water use and the after effects continues to roll in from elsewhere.
In July, the U.S. Department of Energy reported on one of the first, preliminary examinations of what happens to the potentially toxic chemicals that are contained in some fracking fluids injected into the earth.
The department monitored chemicals in Western Pennsylvania for a year. It found that the chemical-laden fluids remained hundreds of metres below the more shallow drinking water aquifers in the region, which is a hotbed for U.S. fracking operations.
In other words, the fracking fluid did not affect drinking water, this study found.
The report is "interesting," Scott Anderson, a drilling expert with the U.S. Environment Defense Fund, told The Associated Press. But it's just one study, and Canadian environmentalists say this information does not seal the case.
"More than 40 per cent of fracking fluids get left in the ground and we know little about their mobilization or fate," says Andrew Nikiforuk, an Alberta-based author and expert on energy and the environment. "Fracking is underground mining and a good example of non-linear chaos. Man-made fractures can connect to natural fractures in unexpected ways."
The not-for-profit Science Media Centre of Canada says that between one and eight million gallons (up to 36 million litres) of water are used in each fracking well, and even when the used water is left in the earth, no studies prior to the U.S. Department of Energy study had looked at what happens to this underground water.
There are also wide discrepancies in the amount of used water that comes to the surface after a fracking operation – between 15 and 80 per cent of the injected water, according to the Science Media Centre. The centre notes that, consistent with the new U.S. study, no well water contamination has been traced directly to deep fracking water, but it also notes that there is "some uncertainty," which makes the coming Canadian Council of Academies report important.
"It should provide us with well-researched data," says Adam Goehner, technical analyst with the Calgary-based Pembina Institute, an environmental think tank.
With the information about water so tentative and preliminary, companies such as Gasfrac Energy Services Inc., based in Calgary and Houston, Tex., see a strong future for technologies such as their use of gelled propane, which Mr. Nikiforuk concedes does minimize water use. Other companies are working with different compounds, such as mixtures of carbon dioxide and nitrogen to lessen the amount of water injected.
It's going to take a lot more evidence to satisfy the industry's critics that new technologies like propane are the answer, though.
"It may minimize water use. But it may still contaminate groundwater," Mr. Nikiforuk says. "Frack fluids that minimize water usage are a bandage on a ruptured artery."