Keystone pipeline leaks estimated 210,000 gallons of oil in South Dakota

Officials do not believe the leak in TransCanada Corp's pipeline, which carries oil from Canada to refineries in Illinois and Oklahoma, affected drinking water

TransCanada Corp's Keystone pipeline leaked an estimated 210,000 gallons of oil in north-eastern South Dakota, the company and state regulators reported on Thursday.

Crews shut down the pipeline on 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.