TransCanada Oil announced the closure of the Keystone pipeline due to an oil spill of approximately 795,000 liters in South Dakota.
The leak took place in Marshall County, near the border with North Dakota.
It was detected early Thursday morning after a pressure drop in the operating system.
Emergency procedures were applied. The section of pipe about 56 kilometers south of the station was isolated in 15 minutes, reports TransCanada.
The spill comes days before the utility announces its decision to approve a license to build the controversial Keystone XL pipeline on Nov. 20.
A potential last regulatory step for this $ 8 billion project for which the US President, Donald Trump, had already given the green light last spring.
This is the second major pipeline leak, after an occurrence in April 2016.
Several antagonists still oppose the pipeline. According to them, it has sandhilis grass dunes covered on its path, a fragile ecosystem, but also farmland and cattle farmers.
The pipeline has to move oil from Alberta’s oil sands to Nebraska.