(BISMARCK, N.D.) — A crude oil spill from the Keystone pipeline in eastern North Dakota has turned out to have affected almost 10 times the amount of land as first reported, a state regulator said Monday.

North Dakota environmental scientist Bill Suess said the leak reported on Oct. 29 is now estimated by state regulators to have affected about 209,100 square feet (19,426 square meters) of land near Edinburg. State regulators had said the leak affected about 22,500 square feet (2,090 square meters) of land.

Calgary, Alberta-based TC Energy, formerly known as TransCanada, estimated its pipeline leaked an estimated 383,000 gallons (1.4 million liters) of oil. Suess said that estimate has not changed.

The cause of the spill is still unknown. An affected portion of the pipe has been sent to a third-party laboratory for inspection, as required by federal regulators.

TC Energy said the pipeline returned to service on Nov. 10 after approval of a repair and restart plan by the U.S. Pipeline and Hazardous Materials Safety Administration.

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