On Friday, federal regulators ordered Plains All American Pipeline LP, the operator of the pipeline responsible for the spill, to determine the causes of the pipeline’s failure. Photo: Justin Sullivan/Getty Images Officials at the U.S. Transportation Department’s Pipeline and Hazardous Materials Safety Administration, the agency responsible for oversight of the line, said Friday the company must fulfill all of the requirements of the corrective order, issued Thursday, before the line can restart pumping oil. The order requires the company to determine the cause of the spill, and test the entire line for any conditions similar to the cause of the rupture. To do so, Plains All American must empty and purge the pipeline, and conduct a physical and analytical review that includes inspections of various engineering records and company data, among other materials. The […]