June 3, 2011 Pipeline Hazardous Materials and Safety Administration (PHMSA) issued TransCanada a Corrective Action Order (CAO), for Keystone's May 2011 leaks. On April 2, 2016, PHMSA issued a CAO to TransCanada for a leak in Hutchinson County, South Dakota, and again on April 9. The pipeline restarted at a reduced operating pressure on April 10 after the U.S. regulator approved the companies corrective actions and plan. A leak occurred in Marshall County, South Dakota in November 2017. This leak occurred early in the morning on November 16, 2017 near Amherst, South Dakota and was contained shortly after detection south of the Ludden pump station.