The Keystone pipeline resumed moving crude oil Sunday after 1.4 million litres (9,120 barrels) of oil were spilled in North Dakota in late October.
Pipeline operator TC Energy will operate it at a reduced pressure, gradually increasing the volume of crude oil moving through the system, the Calgary-based company stated in an emailed release Sunday afternoon. The company said the repair and restart plan was approved by the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA).
The spill was one of the largest on-shore crude oil spills in the region in the last decade and Keystone’s largest spill.
The pipeline, which delivers roughly 93.8 million litres per day from Hardisty, Alta., to the U.S. Gulf Coast, had been shut down since the spill near Edinburg, N.D., was detected on Oct. 29. The spill impacted a nearby wetland.
TC Energy said it’s still investigating what caused the incident and analyzing the segment of removed pipe. “No significant impacts to the environment” have been found so far, the company’s website states.
Around 200 personnel have been working around the clock to clean up the site, and have recovered more than 1.08 million litres of oil.
In 2017, a Keystone leak in rural South Dakota spilled around 1.04 million litres, PHMSA data shows. Earlier this year, Keystone was partially shut after leaking 6,800 litres of crude in Missouri.
TC Energy has been working to expand the pipeline system to double its capacity but has faced regulatory hurdles. Completion of the Keystone XL project is currently slated for 2021.
The differential between West Texas Intermediate and Western Canadian Select sat at around $22 US as of Thursday.