For years, TransCanada, the Canadian company that wants to build the Keystone XL pipeline, has assured the project's opponents that the line will be equipped with sensors that can quickly detect oil spills.
In recent newspaper ads in Nebraska, for instance, TransCanada promised that the pipeline will be "monitored through a state-of-the-art oil control center 24 hours a day, 365 days a year. 21,000 sensors along the pipeline route relay information via satellite to the control center every five seconds."
Other companies make similar claims about their remote sensing technology, sometimes promising they can detect and isolate large spills within minutes.
But an InsideClimate News examination of 10 years of federal data shows that leak detection systems do not provide as much protection as the public has been led to believe.
Between 2002 and July 2012, remote sensors detected only 5 percent of the nation's pipeline spills, according to data from the Pipeline and Hazardous Materials Safety Administration (PHMSA).
The general public reported 22 percent of the spills during that period. Pipeline company employees at the scenes of accidents reported 62 percent.
Anthony Swift, an attorney who has spent years researching pipeline safety for the Natural Resources Defense Council, was taken aback by the findings. Swift's organization opposes the Keystone XL, and he said he had always known that leak detection systems didn't catch most of the spills. But "the fact that 19 out of 20 leaks aren't caught is surprising, and certainly runs counter to a lot of rhetoric we hear from the industry," he said.
Industry experts, however, were not surprised. Pipeline specialists interviewed by InsideClimate News said the findings are consistent with what they have observed.
"The reality of the science" is that there are limits to remote leak detection. "That's just the way it is," said Richard Kuprewicz, president of Accufacts, Inc., a consulting firm that provides pipeline expertise for government agencies, the industry and other parties. Kuprewicz has worked with TransCanada in the past, but is not involved with the Keystone XL.
Operators can feel pressured to "tell people things they shouldn't tell them because it's not true," Kuprewicz said. While the companies "may not be saying that with the intent of lying, the reality is, it's just real difficult to detect [releases] remotely."
TransCanada spokesman Grady Semmens answered questions about the Keystone XL in a series of emails. He said the pipeline's leak detection system will have "greater sensitivity" than is required by law. If the company can't identify the cause of a problem within 10 minutes, Semmens said the pipeline will be shut down and the affected section isolated "to immediately stop the flow of oil."
Leak detection is becoming increasingly important, because the industry plans to build thousands of miles of new pipelines over the next five years. Many of the pipelines will cross aquifers and rivers that are critically important for drinking water. Some of the projects, including the Keystone XL, will carry Canadian diluted bitumen, or dilbit, a mixture of heavy tar sands bitumen and light liquid chemicals. A recent InsideClimate News report on a 2010 dilbit spill in Michigan's Kalamazoo River revealed that the dilbit was much harder to clean up than conventional oil, because it gradually sank to the river's bottom.
The Michigan spill also showed the risk companies take when they tout the effectiveness of their leak detection technology.
Just 10 days before the accident, Enbridge Inc., which operates the Michigan pipeline, told federal regulators it could remotely detect and shut down a rupture in eight minutes. But when the line burst open, it took Enbridge 17 hours to confirm the spill.
Pipeline operators use a variety of methods to look for leaks, but the remote leak detection system—a combination of sensors, gauges, computer software and control room technicians called controllers—is the only one that offers real-time, continuous monitoring along the length of the line.
Operators often cite these systems as an example of their dedication to pipeline safety, particularly when they're questioned by citizens who fear that a leak may go undetected for hours or days.
Such questions are frequently asked in Nebraska, one of the six states along the Keystone XL's path. The line's southern leg, from Cushing, Okla. to the Texas Gulf Coast, is already under construction. The U.S. State Department is expected to decide early next year whether to approve the northern leg, which would cross the U.S.-Canada border.