“Sheer Folly”: CCS and Groundwater

"By cost-effectively capturing CO2 before it is emitted into the atmosphere, transporting it in a pipeline, and storing it safely, fossil fuels can continue to be used in a carbon-constrained world."

“Pumping compressed carbon dioxide into an earth pin-pricked with holes in inherently risky,” reads last week’s Globe & Mail article about the new study (pdf) from the Munk Centre at University of Toronto.

When I noticed a curious advertisement on the back cover of The Walrus a number of months ago, I considered the same thing. Enbridge had taken out space to advertise its leadership in carbon solutions using a simplified diagram of CO2 molecules going down a pipe and bouncing happily in a saline aquifer containing water that is “unsuitable for drinking or agriculture.”

Piqued, I emailed Enbridge to ask about the ad. How is it determined that this saline water is unsuitable for our use? And, more importantly, is there a possibility that sequestration (or the full process of carbon capture and storage – CCS) could negatively affect groundwater supplies?

As you may imagine, I had a hard time getting a response.

With the release of Graham Thomson’s report, however, it looks like I’m not alone. Leakage into and contamination of groundwater are concerns, and the experts are divided.

“The biggest risk of storage and saline aquifers is potential impacts to groundwater,” Dr. Sally M. Benson, executive director of Stanford University’s Global Climate and Energy Project, has said.

Thomson quotes Benson: “Leakage is conceivable, but is unlikely in well-selected sites, is generally avoidable, predictable, can be detected and remedied promptly, and in any case is extremely unlikely to be of a magnitude that would endanger human health and the environment if performed under adequate regulatory oversight and according to best practices.”

Some experts think that the chance that a properly engineered CCS project would contaminate groundwater is a long shot, writes Thomson. And yet, the American Water Works Association says that large-scale CCS projects could endanger underground sources of drinking water—not just through leaks but through displacement of saline. The pressurized carbon dioxide plume injected over years into a saline aquifer would force salt water from the aquifer into underground sources of drinking water, it says.

Not only does CCS present water quality issues, it also raises questions of economics and consumption. The International Panel on Climate Change estimates the cost of sequestering one tonne of CO2 would range from $25 US to $115. A large part of those costs comes from energy requirements. Thomson claims that carbon capture technology is an “energy parasite.” He quotes Charlie Bullinger, senior engineer at the Great River power plant near Underwood, North Dakota: “[Carbon capture] costs half again as much as the cost of the plant, and physically, you have to double the amount of real estate of the plant to retrofit it on the back of a plant that already exists. At a minimum, you’d have to build 30 percent more power plants to get back to the base of where you first started.” Additionally, Thomson highlights an August 2009 report for Australia’s National Water Commission that says “coalfired power plants incorporating carbon capture and storage could be one-quarter to one-third more water intensive [than conventional plants].”

CCS also requires policy decisions that must be based on sound knowledge. Thomson raises alarm here, too: “Given the paucity of groundwater information in Canada and lack of national water standards, the push to accelerate [carbon capture and storage] could pose real risks to our groundwater resources.”

While Thomson’s report frantically produces issue after issue, he does prove that CCS is a complicated conundrum with serious implications, and nowhere as simple as Enbridge’s bouncing molecules and optimistic arrows. What do you think? Should CCS become a reality, will we have another reason to worry for the health of Canada’s groundwater?