My understanding is that, for the large part, the existing pipeline conversion as proposed and the construction for the new line in Ontario is largely going to be only in the very eastern part of the country. I also understand that the exact pipeline route won't be finalized until TransCanada has assessed and incorporated input from numerous stakeholders.
There will be a positive impact for Ontario if it goes forward, but in terms of the new construction jobs, they will be more limited than, say, in Quebec.