TransCanada Corp.’s Keystone pipeline leaked an estimated 210,000 gallons of oil in northeastern South Dakota, the company and state regulators reported Thursday. Crews shut down the pipeline Thursday morning and activated emergency response procedures after a drop in pressure was detected resulting from the leak south of a pump station in Marshall County, TransCanada said in a statement. The cause was being investigated.

Officials don’t believe the leak affected any surface water bodies or threatened any drinking water systems from the spill onto agricultural land, said Brian Walsh, an environmental scientist manager at the South Dakota Department of Environment and Natural Resources, which has dispatched a staff member to the site. “Ultimately, the cleanup responsibility lies with TransCanada, and they’ll have to clean it up in compliance with our state regulations,” Walsh said. READ MORE