Scientists are questioning the most damning evidence that a high-profile Saskatchewan carbon capture and storage project is leaking and dangerous.
Jane and Cameron Kerr, who own a farm near Weyburn, Sask., have cast doubt on the safety of a much-celebrated Canadian project to bury greenhouse gases after a series of bizarre incidents on their property that, they say, show those gases are escaping. After seeing accumulations of algae, unsightly sheens, strange bubbling and dead animals in and around a dug-out pond near their house, the Kerrs abandoned their property several years ago. Last summer, a consultant they hired confirmed that carbon dioxide from the Weyburn project was indeed bubbling up onto their land.
That finding cast doubt on claims by industry and researchers that the Weyburn project is safe, and that carbon dioxide can't escape from its reservoir 1.4 kilometres below the earth. Weyburn is considered a global test case for carbon capture and storage, a technology that has become a centrepiece of Canada's climate-change strategy and attracted huge amounts of public funding, including $2-billion from the government of Alberta. If carbon capture is unsafe, the public-policy ramifications are substantial: Political and environmental critics have already seized on the couple's story as evidence that the technology is wrong-headed.
But scientists say there may be natural explanations for many of the couple's experiences. They also say the "smoking gun" in their consultant's report may in fact signify nothing.
The most striking evidence found by the Kerrs' consultant, geological engineer Paul Lafleur, is that the carbon dioxide in soil gas on their property "is clearly the anthropogenic CO2 injected into the Weyburn reservoir."
Mr. Lafleur came to this conclusion after studying the isotopic signature of the gas, which he said was indisputably man-made. A lawyer for the family stood by that conclusion Thursday.
But those who have studied the Weyburn area for a decade as part of an $85-million research project on the injection site dispute Mr. Lafleur's conclusion. While the "fingerprint" of the Kerr gas does match the injected gas, it also matches the fingerprint of naturally occurring gases sampled in regional baseline studies in 2001, before the Weyburn project began full operation.
In fact, those samples found some fingerprints identical to those Mr. Lafleur discovered, said Steve Whittaker, a senior project manager at the Petroleum Technology Research Centre in Regina, which has led the massive study for the International Energy Agency.
The Kerr property gas's "isotopic composition is similar to background values in soil gas and it is not conclusive that it's [man-made]" he said. "For them to claim that it is indicative of the injected gas is not appropriate."
Mr. Whittaker's centre tested the Kerrs' well five times between 2002 and 2006 and found no indications of carbon dioxide in the water. In fact, levels of indicator substances fell slightly during that time.
Other elements of the Kerrs' story have also drawn questions. Samples collected a decade ago suggest that the high levels of carbon dioxide in their soil are not unusual for the area. A strong presence of the gas in the air can cause rapid asphyxiation. However, areas where carbon dioxide is known to leak into the soil - such as Mammoth Mountain, Calif., where it has killed trees - show soil gas concentrations of 20 to 90 per cent; the average on the Kerr property was 2.3 per cent. Even in Mammoth, it's considered dangerous only to those digging or lying on the ground.
Geologists also say the bubbling in the Kerr pond may be a release of natural gas, which fizzes like carbon dioxide and is prevalent in the hydrocarbon-rich region. And biologists say there may be other reasons for the odd pond growths and animal deaths. Kenneth Wilson, an assistant professor of biology at the University of Saskatchewan, has examined photos the Kerrs took of the growths. He said they look like blue-green algae, which is common in Prairie surface water.
"To get blooms like that, usually it's due to either runoff of fertilizer, or it can also happen quite naturally," he said. "They happen in sloughs all across the Prairies."
Those blooms can also be dangerous. Some of the cyanobacteria that make up blue-green algae form poisonous toxins. In fact, the government of Saskatchewan occasionally warns people to keep themselves, livestock and pets away from blue-green algae, some of which has a "foamy, sheen-like appearance" and can cause various ailments, even death.
At least one of the Kerrs' animal deaths appears to have occurred at the time algae was present.
"We'd be out to the pond and notice a blue slick and go back three hours later and find a rabbit that had dropped dead," Jane Kerr told The Globe this week.
Still, researchers say it's impossible to conclusively say what is happening on the Kerr property without gathering more data. Mr. Whittaker said a more in-depth study, which the Kerrs continue to call for, should be conducted to properly resolve the matter.
"I'm not discrediting what they're saying," he said. "I know this couple truly believes something is going on. And if something is there, we certainly want to find it."