TC Energy will operate the pipeline at a reduced pressure with a gradual increase in the volume of crude oil.
Some wetlands appear to have been affected, but not any sources of drinking water.
Delivery will begin with commercial operation, which is targeted for the end of September in 2020.
Subsidiary Columbia Midstream Group owns four natural gas gathering systems.
TC Energy will retain a 15% stake and remain the operator of the pipeline.
TransCanada says its new name, TC Energy, reflects its diverse business interests in pipelines, power generation and energy storage operations.