The Pipeline and Hazardous Materials Safety Administration (PHMSA) has reported that Plains All American’s 901 and 903 pipeline spill on 19 May 2015 along the Santa Barbra coast (USA), was caused by external corrosion.
The pipeline had leaked approximated 2400 bbls (over 140 000 gal.) of oil from the corroded pipe. The spill occurred after a shutdown was called on the pumps for the pipeline. As a result, after the pumps were restarted, a larger volume of oil flowed through the pipe at a high pressure, which breached the corroded 2 ft section of the pipe.
Read coverage of the May incident here.
PHMSA stated that it discovered “extensive” corrosion in the pipeline; the pipe walls had been degraded by approximately 74% of their original thickness in certain parts. In its recent report, the PHMSA explained: “The results of the metallurgical analysis indicate that the leak occurred at an area of external corrosion that ultimately failed in ductile overload under the imposed operating pressure. The morphology of the external corrosion observed on the pipe section is consistent with corrosion under insulation facilitated by wet-dry cycling.”
Marie Therese Dominguez, the Department of Transportation's PHMSA Administrator, stated that the extreme corrosion was missed in the pipelines previous inspections.
Rep. Lois Capps offered similar advice: "While we must continue to evaluate what went wrong in this situation, we must also ensure that we learn the lessons of the spill and take action to protect other communities from the same damage."
Edited from various sources by Stephanie Roker
Read the article online at: https://www.worldpipelines.com/regulations-and-standards/19022016/phmsa-extensive-corrosion-caused-plains-may-oil-spill/