It's great question. I won't be able to provide a precise quantitative answer to that.
I think much more investigation is warranted into what the precise factors were behind those cost overruns, and there were many. I think of the regulatory barriers that have ratcheted up in recent years. I say this not just because of recent changes in federal policy, but early on in the pipeline's efforts to get off the ground, there were challenges with the British Columbia provincial government, for example, as Kinder Morgan was trying to get that project over the line.
There were non-regulatory barriers as well. The simultaneous construction of Site C and Coastal GasLink, for example, does represent some competition for resources and skilled labour, if you will, that can increase costs of all of those projects together. Conditions on the ground also turned out to differ significantly from those initial estimates.
On top of all of this, COVID-19 and associated rapid price increases for certain key materials in the construction sector overall are also a factor.
I'd say that a lot of unfortunate challenges did face the project, but regulatory delays are certainly a big one. These kind of very large projects do incur considerable costs prior to any construction activity at all. Thinking about not just the regulatory burden that proponents need to overcome, but also the rapid and uncertain changes in the regulatory environment also make it more difficult to plan and navigate these kind of large infrastructure projects well.