I'm extremely skeptical of the whole thing, but I'm trying to learn more. The article you shared says:

Many geologists (myself included) believe there are places on Earth where long-term CO2 storage could be safely achieved, but it would require what scientists call “site characterization.” That means studying the location in enough detail to be confident that things put there will stay there. For example, the U.S. currently stores military radioactive waste in low-permeability salt formations in New Mexico, and there are numerous pending proposals to store CO2 in sandstones overlain by low-permeability shales in North Dakota.

Okay, so the CBC article seems to suggest that the site in question has been studied.

At the storage hub, the gas would be injected deep underground in the Basal Cambrian Sandstone formation, which sits one to two kilometres below the surface. The sponge-like sandstone has spaces that can be filled with CO2.

Above that formation is thick, non-porous rock salt that can act as a barrier to keep the carbon dioxide in the ground.

I have no idea whether it's been studied sufficiently, but the author of the article you shared seems to think it can be effective if that step is taken.

And I think even the most optimistic proponents of carbon storage argue that it's a means of mitigating the effects of heavy industry, not of making a meaningful difference in other ways. But they seem to think those mitigating effects can be important, and maybe even necessary?