From the TSB perspective, we are not responsible to look into the design and construction of new pipelines. The National Energy Board would have to approve the design and construction of any new pipelines. That would include the specifications that apply for mountainous terrain and the environmental considerations and geotechnical considerations are all factored in.
The companies would have to present their designs, and get those approved. The construction would be inspected and approved by the NEB before they would be allowed to operate any pipeline.
The National Energy Board would be the best organization to provide you with details of how they would do that, and the extent of their review and approvals.