By OGJ editors
WASHINGTON, DC, Feb. 12 -- The National Transportation Safety Board called on US pipeline operators Tuesday to accelerate a new industry standard designed to minimize internal corrosion in steel pipelines.
The board's recommendation was included in a new report on the causes of a fatal accident involving the rupture of a 30-in. natural gas line owned by El Paso Co. in Carlsbad, NM, Aug. 19, 2000.
The explosion and fireball that resulted from the rupture killed 12 campers (OGJ Online, Aug. 20, 2000)
Causes
NTSB said that the pipeline tore open because of "severe" internal corrosion and a "significant reduction in pipe wall thickness."
Investigators blamed El Paso for "failure to prevent, detect, or control internal corrosion within the company's pipeline." Contributing to the accident were ineffective federal inspections of the company's internal corrosion control program that did not identify deficiencies, the board said.
NTSB noted that the pipe section that ruptured could not accommodate mechanical cleaning "pigs" used to remove water and other liquid and solid contaminants that can cause pipeline corrosion. In a related issue, the board noted that there was a partial clogging of the "drip," or stub line that branches off the bottom of a gas pipeline and collects liquids and solids that may have built up in the pipeline during normal operations.
NTSB said its investigation revealed that some liquids bypassed the drip and continued through the pipeline, further weakening the line, including the eventual rupture site. That's because the drip became partially clogged upstream of the rupture location. "At the rupture site, a bend in the pipe had created a low point in the pipeline where liquids and other residue accumulated and caused corrosion," NTSB said.
Blame assessed
The board faulted El Paso for not having an internal corrosion control program that was adequate to identify or mitigate the internal corrosion occurring in its pipelines before the accident.
"Had (El Paso) effectively monitored the quality of gas entering the pipeline and the operating conditions in the pipeline and periodically sampled and analyzed the liquids and deposits for corrosivity that were removed from the line, it would likely have detected the potential for significant corrosion to occur within the pipeline," the board said.
But federal regulators are also to blame for the accident, the board concluded: "Overall, the board found that the current federal pipeline safety regulations do not provide adequate guidance to pipeline operators or enforcement personnel in mitigating pipeline internal corrosion."
New rules
Since the accident, Congress has passed and President George W. Bush signed into law last December stronger pipeline safety rules (OGJ, Feb. 3, 2003, p. 70). The Department of Transportation's Research and Special Programs Administration, including the Office of Pipeline Safety, is promulgating rules to meet the new, stricter requirements.
Along with tougher federal measures, the board called on NACE International (formerly known as National Association of Corrosion Engineers) to update their standard known as RP-01-75.
Board investigators also reminded federal regulators to develop the requirements necessary to ensure that pipeline operators' internal corrosion-control programs address the role of water and other contaminants in the corrosion process. And they want OPS to evaluate its pipeline operator inspection program to identify deficiencies that resulted in the failure of the inspectors prior to the Carlsbad accident, to identify the inadequacies in El Paso's internal corrosion-control program. Then regulators should implement changes "necessary to ensure adequate assessments of pipeline operator safety programs."
Reactions
Reacting to the report, industry officials and federal regulators stressed that, since the accident more than 2 years ago, they have taken "aggressive measures" to improve pipeline safety and intend to follow the board's recommendations.
An embattled El Paso responded to the report with a statement saying, "As a company and as individuals, we have been deeply affected by the Carlsbad tragedy, and we have sought to learn from it.
"We have implemented an aggressive, comprehensive approach to pipeline integrity that addresses the full range of known risks, including internal corrosion. We have cooperated fully with the NTSB from the beginning of this investigation and with the other government agencies looking into this matter. We will address the recommendations issued by the NTSB as they apply to El Paso, and our cooperation will continue."
As the report was released, El Paso was already grappling with allegations of market manipulation during California's 2000-01 energy crises, a looming proxy fight stemming from shareholder allegations of securities fraud, and a meltdown in its stock price. The company's CEO, William Wise, last week announced he would be leaving the company by yearend.