Written in Stone

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Nova Scotian Geologist Unsure of Alton Gas

By Zack Metcalfe

zack.metcalfe@gmail.com

FORT ELLIS: The health of the Shubenacadie River is time and again the focus of resistance to Alton Gas, the company intent on hollowing out local salt caverns and dumping the resulting brine into this fragile watershed.

A local geologist, however, is equally concerned with the caverns themselves.

Robert Grantham has spent a career underground, serving as a mining geologist in northern Manitoba and as curator of geology at Nova Scotia’s Museum of Natural History. He took active part in establishing Newfoundland’s Johnson Geo Centre as its founding executive director, and is a past president of the Atlantic Geoscience Society. Retirement found him in 2014.

“It’s not a happy situation ,” he said. “My problem is that I can’t get any information out of the company. I’ve tried many times and just can’t.”

The holes drilled by Alton Gas to locate these salt deposits contain a wealth of information for people like Grantham, namely the amount of salt and what other mineral deposits exist throughout. The integrity of any would-be caverns can be predicted from these drill holes, except their contents have not been made publicly available.

If these holes revealed solid, uninterrupted deposits of salt, said Grantham, the caverns they produce would probably hold natural gas without issue. If these deposits of salt are mixed, however, with layers of limestone or dolomite, these minerals will expose resulting caverns to weakness. If this should happen, and these caverns fail pressure tests, they will be useless, and the entire project will come to a halt. In this way, Alton Gas might be setting itself up for failure.

“If there are interspersed beds of any kind in the salt, it could create a leak, and that’s the problem,” said Grantham.

After raising these concerns and others in print several years back, Grantham received a call from an unnamed vice president of the Calgary based AltaGas, parent company to Alton Gas. While they would not give him the results of their drill hole analyses, they did read some results aloud over the phone. Apparently, there’s a lot of dolomite down there, raising red flags for Grantham.

“My whole problem is a lack of information from the company about the geology, about their drill holes, and about how much salt they’re encountering in each hole,” he said. “Without that information made public, they’ll dig out these caverns, dump all of this salt into the Shubenacadie – which is a horrible idea – and then, if it fails the pressure test, it’s game over. So, why not share the information about the geology now? Why not let experts talk about it?”

Cavernous natural gas storage is not a novel technique. Grantham is aware of similar projects and while, to his knowledge, there are no summary reports of their performance, his impression has been that no storage cavern is without its problems. A similar project undertaken in Port Hastings, Cape Breton, in the 1970s produced several such caverns, all of which failed pressure tests and were never used.

“I can see the same thing happening here,” he said.

And then there are earthquakes. Grantham said such terrestrial tremours are not unheard of in the Maritimes and are probably a consequence of the region rebounding from the last ice age (we’re still settling after the melting of heavy glaciers). These earthquakes have not been significant – 3.8, 3.9 – enough to rattle dishes and spook wildlife, but not enough to do serious damage.

The mass removal of salt to produce misshapen caverns might result in local instability, said Grantham, making earthquakes a possibility in the Stewiacke area, the severity of which cannot be guessed. He points to the increased frequency of earthquakes (by orders of magnitude) from hydraulic fracturing operations across North America.

“I’m not against the project, not at all, but I am against not sharing information and not proving, to me and the public, that these caverns can be developed safely and appropriately,” said Grantham. “I’m after professionalism; I’m after a high standard. I would love to meet with Alton Gas, to go over their interpretations of their drill holes, but that will never happen.”

Zack Metcalfe is a freelance journalist, columnist and author active across the Maritimes.