"Federal regulators [Wednesday] released an order granting Exxon Mobil Corp. its second extension to finish investigating the cause of a pipeline rupture that spilled an estimated 5,000 barrels of Canadian oil sands crude in the Arkansas suburb of Mayflower 10 weeks ago."
"In its request for an extra month to determine why its Illinois-to-Texas Pegasus line burst, Exxon told the Pipeline and Hazardous Materials Safety Administration that its first test results called for more study 'to better understand the pipe properties and potential failure mechanisms.' The March 29 leak on Exxon's 96,000-barrel pipeline upended the already tense lobbying battle over White House approval of the Keystone XL oil link, as it would carry heavy Canadian crude similar to the fuel that spilled in Mayflower.
Exxon cited 'unforeseen testing delays' in requesting its first extension of PHMSA's initial May 17 deadline for testing. PHMSA agreed to give the oil company's pipeline arm until July 10 to produce a report on the likely cause of the Arkansas leak."