Photographs of the pipeline that spilled oil off the Santa Barbara coast last month show extensive corrosion and provide clues about the cause of the rupture, federal regulators say.
What’s the Problem?
June 17, 2015 – Corrosion seen around the crack, combined with wear inside the pipe likely led to the rupture after a pressure spike when the operator restarted pumps on May 19, says Robert Bea, a civil engineering professor at UC Berkeley.
Photos released to the AP yesterday under a California Public Records Act request show the 6” rupture that spilled up to 101,000 gallons of oil, coating beaches and killing hundreds of birds and marine mammals. Bea said other photos released by Santa Barbara County show that approximately 10% of the pipe’s outer wall had worn away from corrosion.
Plains All American Pipeline, the company that operates the ruptured pipe, has declined to speculate as to the cause of the spill while it’s being investigated. Plains has apologized for the oil spill and is footing the bill for the cleanup costs, which have exceeded $62 million.
It is still unclear what the Pipeline and Hazardous Materials Safety Administration (PHMSA) will require Plains to do once the investigation has concluded. The agency initially ordered the company to keep the ruptured pipe and a bigger pipeline it joins shut down while tests are being conducted.
Richard Kuprewicz, a pipeline safety expert and president of Accufacts Inc., said that although the photos were revealing, they don’t show enough detail to reach conclusions about the cause of the rupture; however, he said there was significant deterioration in the protective wrapping around the pipe which could undermine cathodic protection, an electrical current that runs through the pipeline to prevent corrosion.
Bea also said that a sag in the pipe near where the rupture occurred could have led to greater corrosion inside and outside the pipe, making it harder for cathodic protection to be effective.