A probe by the U.S. National Transportation Safety Board concluded Enbridge did not fix a defect on the pipeline when it was discovered five years earlier and control room staff responded poorly when Line 6B ruptured on July 25, 2010.
"Learning about Enbridge's poor handling of the rupture, you can't help but think of the Keystone Kops," said NTSB chair Deborah Hersman, referring to the incompetent policemen in silent films.
"Why didn't they recognize what was happening? What took so long?"
Enbridge (TSX:ENB) has billions in new pipeline projects and expansions in the works, including contentious plans to ship crude to the West Coast and to Central Canada.
Critics of the company's proposed Northern Gateway pipeline between Alberta and the B.C. coast as well as expansion to ship more Alberta crude eastward seized on the NTSB report as evidence the company should not be allowed to build those projects.
Hersman said Enbridge knew about a corrosion problem on Line 6B in 2005 — well before it ruptured and caused the most expensive onshore spill in U.S. history.
"Yet, for five years they did nothing to address the corrosion or cracking at the rupture site — and the problem festered."
The NTSB said it took 17 hours and 19 minutes for Enbridge staff to respond to alarms signalling a problem on the line in southern Michigan. And when they did respond, it was only after a worker with a local natural gas utility informed them of the spill.
Instead of stopping the flow, Enbridge staff misinterpreted the alarms and twice pumped more crude into the ruptured pipeline — representing about 81 per cent of the total spill, Hersman said.
More than three million litres of crude oil spilled into nearby wetlands, Talmadge Creek and the Kalamazoo River.
The total cleanup cost more than $800 million — more than five times the next most expensive onshore oil spill, Hersman said, citing figures from Enbridge and the U.S. Environmental Protection Agency.
She said poor regulatory oversight by the Pipeline and Hazardous Materials Safety Administration was also to blame.
"Delegating too much authority to the regulated to assess their own system risks and correct them is tantamount to the fox guarding the hen house," she said.
But Hersman said PHMSA did take the "necessary and important step" of proposing a $3.7-million fine against Enbridge last week.
In a release, Enbridge CEO Pat Daniel said the employees involved at the time of the spill were "trying to do the right thing."
"As with most such incidents, a series of unfortunate events and circumstances resulted in an outcome no one wanted."
He said the Kalamazoo River has since been re-opened for recreational use and that wildlife has returned to the area.
Stephen Wuori, Enbridge president of liquids pipelines, said the company has made changes after undertaking a thorough internal investigation.
"We will carefully examine the findings in the NTSB report to determine whether any further adjustments are appropriate."
NDP Natural Resources critic Peter Julian said the NTSB report was a "wake-up call" for Canada, especially after changes to the country's environmental review process passed Parliament last month as part of the Conservatives' controversial omnibus budget bill.
"The government is behaving in a profoundly irresponsible fashion," he said from Burnaby, B.C.
"And when you couple that with a company that has had repeated spills and seems to be, according to the NTSB, taking advantage of the fact that there isn't sufficient regulatory oversight, we've got a perfect storm."
Enbridge's Northern Gateway proposal would link oilsands crude to Asian markets, allowing Canadian companies to get a better price for the oil they produce. Enbridge has said it's confident it can operate the pipeline and marine terminal safely with top-notch procedures and equipment.
But First Nations groups, environmentalists and others fear that a spill from the pipeline or from the tankers that would travel in and out of the pipeline's terminus at Kitimat, B.C., could cause severe environmental damage.
"This should be the last warning signal we need that Enbridge cannot be trusted to build a tar sands pipeline through the largest intact temperate rainforest left on the planet," said Greenpeace campaigner Mike Hudema.
Enbridge also has big plans in the works to ship crude eastward from Alberta by expanding its existing system — including the one that broke in Michigan, 6B — and reversing the flow of Line 9 between Montreal and southern Ontario.
Gillian McEachern of Environmental Defence said Enbridge can't be trusted to ship crude through Ontario.
"The U.S. government found repeated instances of disregard for safety. The simple fact is if Enbridge can't ship tar sands oil safely in Michigan, why would it in Ontario?" she asked.
Jamie Ellerton of the group Ethical Oil said it's a "terrible thing" when pipelines spill, but "North Americans will continue to rely on fossil fuels for decades to come and pipelines are the safest and most effective way of transporting petroleum products to market."
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