When diluted bitumen escaped from an Enbridge-owned pipeline in Michigan in 2010, the company quickly realized the tools it had been using to monitor the integrity of its network weren't up to the job.
The stress crack caused the pipeline to spill about 20,000 barrels of oil, much of it ending up in the Kalamazoo River. Cleanup operations have been going on for years and the spill is used as the prime exhibit for those opposed to the company's plan to build the Northern Gateway pipeline through northern B.C.
On Tuesday, Enbridge vice-president of pipeline integrity Walter Kresic told a Northern Gateway Community Advisory Board meeting at the Coast Inn of the North that even a large spill like the one in Michigan, doesn't mean the entire network is unsafe.
"The [inspection] technology wasn't as good as it should have been," he said. "Any of the new tools would have seen [the problem]."
Kresic said the spill was a turning point for both the company and the industry and work has been done to ensure the issues leading to a similar spill would be found and corrected before it reaches the point where oil would leak out.
"Marshall was a significant learning time for us when we knew that we could apply other safety management systems to provide further levels of defence," he said. "It's not just the technology, it's how you use the technology."
The Northern Gateway pipeline, proposed to connect northern Alberta with a port in Kitimat, is undergoing an environmental assessment with a report due later this month.
Kresic's hour-long presentation focused on what inline inspection tools are available to pipeline companies, how they work and what they measure. If Northern Gateway is built, the company would employ a host of tools to check on deformation, corrosion and cracking.
"The deformation and the corrosion tools will be run roughly every two to three years and the crack tool will be run every five years," he said. "We'll see how that cycle works and if there's any change needed then we'll increase the frequency."
To test for abnormalities, complex sensors up to nine metres in length are inserted into the pipeline while the pipeline is in operation. The oil pushes the tools down the pipe at rate slightly faster than a walking pace and sensors use technology like ultrasound or magnets to asses the condition of the pipeline millimetre by millimetre.
In the case of Northern Gateway, the pipeline will be divided into three sections for inspection. After an inspection tool makes its several week journey during each segment it's sent back to the vendor where the data is downloaded and analyzed, a process which can take anywhere from weeks to months.
"Some of the tools are more complex, the data, so they take up to four months, but some come to us in a couple of weeks if it's a simple inspection," Kresic said.
If a flaw is detected, the often the first step the company takes is to reduce the pressure in the line. The company can also choose to excavate the line to take a closer look the issue.
Kresic said excavations are also part the routine inspection practices to ensure the pipeline is in good, working order.
"On our system in 2013 we did in excess of 2,500 excavations across our system, which is a large number of digs," he said. "Each dig is roughly 10- to 30-metres in length and when we're there we check every square inch of the pipe and it gives us a perspective on how the rest of the pipeline is doing."
Despite all the tools at the company's disposal, Kresic said the Michigan spill proved the technology is not infallible, but he said the company is committed ensuring such a spill doesn't happen again.
