WASHINGTON—The most expensive oil pipeline spill in U.S. history could have been prevented if the pipeline operator had repaired known defects on the line, a federal agency said on Tuesday after a two-year investigation of the spill.
The accident occurred near Marshall, Mich. on July 25, 2010, when a ruptured pipeline owned by Enbridge, Inc. sent more than one million gallons of diluted bitumen (crude oil from Canada's tar sands) into the Kalamazoo River and surrounding wetlands. Cleanup of the river is ongoing, and total costs have reached more than $800 million.
The National Transportation Safety Board concluded that Enbridge's integrity management program—the system used to respond to cracks and corrosion defects—was inadequate for pipeline safety.
NTSB investigators also cited factors that they said worsened the spill and increased the amount of oil that leaked into the river. Mistakes in the company's Alberta-based control room allowed the leak to go undetected for over 17 hours as oil continued to flow through the line. And once it was detected, the company's initial response was ineffective due to a lack of equipment and trained personnel.
"This investigation identified a complete breakdown of safety at Enbridge," Chairman Deborah A.P. Hersman said during Tuesday's NTSB meeting. "Their employees performed like Keystone Kops and failed to recognize their pipeline had ruptured and continued to pump crude into the environment. Despite multiple alarms and a loss of pressure in the pipeline…they failed to follow their own shutdown procedures."
The rupture resulted from a series of cracks on pipeline 6B that grew and coalesced into a gash of more than six and a half feet.
Enbridge first learned about the cracks after a 2005 inline inspection conducted by a contractor. Although the problem was serious enough to merit excavation and repair, it was misinterpreted as a minor defect and never addressed.
"Enbridge detected the very defect that led to this failure (in 2005)," Hersman said. "...Yet for five years they did nothing to address the corrosion or cracking at the site, and the problem festered."
The board also cited a regulatory gap. "We saw the operator take advantage of weak regulations," Hersman said.
Oversight of the nation's 2.5 million-mile pipeline system falls to the Pipeline and Hazardous Materials Safety Administration (PHMSA), a division of the U.S. Department of Transportation with fewer than 500 employees. The agency often relies on operators to self-report pipeline defects, and there are no clear requirements on when to repair corroded or cracked segments.
"This accident was the result of multiple mistakes and missteps made by Enbridge. But, there is also regulatory culpability," Hersman said. "Delegating too much authority to the regulated to assess their own system risks and correct them is tantamount to the fox guarding the henhouse. Regulators need regulations and practices with teeth."
The NTSB, an independent agency, listed 17 new safety recommendations directed at Enbridge, PHMSA, the U.S. Secretary of Transportation and other organizations including the American Petroleum Institute. It urged PHMSA to tighten corrosion regulations and conduct detailed reviews of operators' emergency response plans. It urged Enbridge to improve its integrity management program and to better train its control center operators in spill detection.
Cleanup of the 6B rupture has been particularly difficult because the oil that spilled was diluted bitumen, or dilbit, from Canada's tar sands region. Unlike conventional crude oil, much of the dilbit sank underwater, and it could be months or years before the cleanup is complete.
During a brief session with reporters after the three-hour meeting, Hersman said that NTSB's duties do not include addressing what type of oil 6B was transporting and whether it contributed to corrosion on the steel pipe. NTSB investigators did make it clear that corrosion was external on the spot where 6B ruptured.
But Hersman noted that one of the recommendations that NTSB presented to PHMSA on Tuesday was a repeat of a previous NTSB recommendation: That pipeline operators provide information about pipe diameter, operating pressure, product being transported and potential impact radius to emergency response agencies in communities with pipelines. If PHMSA adopts that recommendation, it will be up to the agency to decide whether operators need to specify the kind of crude oil—dilbit or conventional crude—in their pipelines.
Enbridge CEO Calls Review Fair
Patrick Daniel, chief executive officer and president of Enbridge, said the NTSB wasn't out of line in directing Enbridge to improve its pipeline integrity management, inline inspections, leak detection systems and make public awareness about its pipelines a priority.
"I think they have been fair to Enbridge," Daniel told InsideClimate News after sitting through the entire meeting. "It was a very thorough review. We have already implemented many of the recommendations. To tell you the truth, we started two years ago."
Daniel emphasized that Enbridge was under the impression it had a company-wide culture of safety before July 2010 when 6B ruptured in Marshall, Mich.