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.
The Keystone pipeline is part of a 2,687-mile system that also is to include the proposed Keystone XL pipeline, which has faced persistent opposition from environmental groups, American Indian tribes and some landowners.
The Nebraska Public Service...