In a new report released today, the National Wildlife Federation took a look at data on currents in the Straits of Mackinac. That’s where Enbridge’s twin pipelines run along the bottom of Lake Michigan.
Mike Shriberg is the executive director of the Federation’s Great Lakes office.
“What this report shows is that there are additional stresses on this pipeline beyond what it was designed for," he says.
Shriberg says we have more information about the velocity of the currents in the Straits than we did back in the 1950s when the pipelines were designed.
“The actual currents under the Straits are up to two times as strong as what the line was designed for, and it calls some significant questions into whether Line 5 can handle these greatly increased velocities,” he says.
Enbridge says the pipelines can handle the currents. Ryan Duffy is an Enbridge spokesman.
“You know, these are issues that have been raised before and we have addressed in the past. These are things that we are constantly and continuously inspecting for along Line 5 and all the tests we’ve done until this point have shown that the line is in very good condition,” says Duffy.
Duffy says a report by the Pipeline and Hazardous Materials Safety Administration from last May looked at several issues, including pipe movement.
The NWF's Mike Shriberg responded by email:
The report prepared by the LaMontagne Pipeline Assessment Corporation [the PHMSA report] summarizes Enbridge’s inline inspection data and is specifically not a “fitness for service” assessment. Page 44 of Dr. Ed Timm’s report [the NWF report] directly references and addresses the LaMontagne report, putting it into the context of the Timm report. One key difference is that the LaMontagne assessment was much more narrow in focus than Dr. Timm’s report. Even with this more narrow scope, the LaMontagne assessment found metal loss and crack-like anomalies that are consistent with the Timm report. Another major difference between the reports is that the Timm report, as part of its broader scope, looked at how the pipelines are under stress from stronger currents than the original pipeline engineers expected. The LaMontagne report did not. Despite these differences, one of the key conclusions from the LaMontagne report - that "Continued vigilance with respect to pipe movement is warranted.” – is very consistent with Dr. Timm’s conclusion. In fact, the new information released today greatly increases the need for this vigilance and adds to the mounting evidence that we should not trust the future of the Great Lakes to oil pipelines well beyond their design life.
These issues are likely to come up in Lansing on Monday during the next meeting of the Michigan Pipeline Safety Advisory Board. The advisory board was established by executive order by Governor Rick Snyder.
Editor's note: Enbridge is a financial supporter of this station.