TransCanada has estimated that a pipeline leak detected earlier this week in South Dakota spilled about 16,800 gallons of oil.
According to the AP, the company told the National Response Center and the Pipeline and Hazardous Materials Administration (PHMSA) on Thursday that a leak at the Keystone pipeline released 400 barrels of oil.
TransCanda based its estimate on soil excavation work that exposed 100 feet of pipeline and included oil observed on the ground as well as the potential area impacted by the spill in its estimate.
The leak was initially detected on Saturday along the pipeline’s route near Freeman, South Dakota.
TransCanada said on Monday that emergency crews found “visible signs of oil on [a] small surface area” near the line.
PHMSA officials arrived at the site on Tuesday.
The cause of the spill is still being investigated.
The Calgary-based company said earlier this week that it expected flows from Alberta, Canada to Cushing, Oklahoma to be halted until at least Friday.
The section of the line that connects Cushing to the pipeline’s section in Texas is still operating.
TransCanada said on Tuesday that it will “continue to work with regulatory and government agencies on our response efforts.”