WASHINGTON, Kan. — TC Energy has restarted the “unaffected” sections of the keystone pipeline, following last week’s oil spill in northeast Kansas.

It’s the largest spill in the history of the Keystone pipeline, resulting in hundreds of thousands of gallons of oil spilled near the Kansas-Nebraska border.

The pipeline carries oil from Canada to terminals in the United States.

TC Energy needs regulatory approval to restart the parts of the pipeline affected by the spill.

Kansas Governor Laura Kelly said she’s waiting on the findings of the investigation to decide the next steps.

The spill has been contained, according to local officials. No drinking water supply has been impacted.

TC Energy was granted a special permit from the Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA), which allows it to operate certain portions of the pipeline at higher stress levels than other lines.

The permit has received pushback from some democratic lawmakers, calling for stricter regulations.