Pipelines are an important but controversial means of transporting liquid and gas fuels over long distances, since once installed, they have very low operating costs and are often safer than rail or truck transportation. However, if leaks develop, they can be extremely damaging and costly to clean up. Furthermore, some highly explosive materials have the potential to cause catastrophic damage, posing an unacceptable risk to surrounding communities.

The high initial cost of pipeline construction means that it must remain in operation for decades in order to become profitable. As a result, any new pipline proposal implies a commitment of at least 30 years, further entrenching demand for fossil fuels.