Source: National Transportation Safety Board
National Transportation Safety Board Chairman Deborah A.P. Hersman today provided an update to a U.S. House of Representatives committee on the progress of the NTSB's investigation into an oil spill in Marshall, Michigan in July.
Testifying before the House Committee on Transportation and Infrastructure, Chairman Hersman reported that, although an official National Response Center report on the oil release was not issued until almost 1:30 p.m. on Monday, July 26, the leak may have started as early as the previous evening. Safety Board investigators arrived at the scene on Tuesday and found that the section of pipeline that ruptured was located in a swampy, wetland area, which was further saturated by the volume of oil that had spilled (estimated to be as much as 1 million gallons).
"Although many aspects of NTSB investigations are technical in nature, we are ever-cognizant of the collateral cost of accidents such as this," Chairman Hersman said. "The economic and environmental consequences of a spill of this magnitude are significant."
The pipeline is owned and operated by Enbridge Energy Partners (NYSE:EEP) of Calgary, Canada. The NTSB was able to remove and transport two sections of pipe, each exceeding 20 feet in length, from the accident site to its Training Center in Ashburn, Virginia for examination (the same facility where the section of pipe from last week's San Bruno accident is being shipped).
Hersman listed areas of progress in this investigation so far, such as completion of documentation of the coating system on the pipe and nondestructive testing of the ruptured pipe piece that found surface cracks and indications of corrosion.
She outlined six areas of inquiry the NTSB will pursue in this investigation: Supervisory Control and Data Acquisition (SCADA) data. SCADA is a system used by pipeline companies to monitor performance of their systems in real time. Pipeline controller performance. Operator notification and spill response. Responses to 9-1-1 calls. Inspection and maintenance history of the pipeline. Oversight activities and actions of the Pipeline and Hazardous Materials Safety Administration.
Last week, another Enbridge pipeline leaked oil in Illinois. That accident is being investigated by the NTSB, and the section of pipe that failed is being shipped to the Board's Ashburn facility for evaluation.