LANSING - A new analysis prepared by Dr. Edward E. Timm, PhD, PE, a retired Dow Chemical engineer, demonstrates multiple errors and omissions throughout the State of Michigan's Line 5 Alternatives Analysis.
“The plethora of questionable assumptions and unsupported conclusions found in many areas of the Alternatives Analysis raise questions about the lack of intellectual curiosity and objectiveness necessary for this kind of work to be credible,” said Dr. Timm. “As a result of these errors and omissions, at a minimum, it is recommended that an interdisciplinary group of technical experts drawn from a range of industry and non-industry sources be assembled to more closely examine the fitness for service of Line 5 under the Straits.”
Key findings included in the new study include the following:
√ One of the most important conclusions of the Dynamic Risk study—evaluating the condition of the 64-year-old Line 5—utilizes incomplete analysis, making it highly suspect and raising questions about the study’s credibility.
Over its 64 -year history, strong currents in the Straits of Mackinac have scoured the lake bottom underneath Line 5. According to public documents, Enbridge allowed multiple unsupported spans to develop during the first 50 years of Line 5’s operation, raising the risk of pipeline failure from bending stress and fatigue. Enbridge’s efforts to maintain pipeline supports were especially deficient during the 23-year period beginning in 1980 and ending in 2003. Yet Dynamic Risk failed to factor into its risk analysis the impact of 50 years of unsupported pipeline spans. Instead, Dynamic Risk estimated pipeline risk using a flawed mathematical model and assumed the pipeline to be in brand new condition, starting their analysis in 2018 and predicting a risk of pipeline rupture to 2053. They estimated a 1 in 60 chance of pipeline rupture through 2053 - but in fact, the pipeline has endured multiple rounds of span damage over the years. As a result, the expected failure probability of Line 5 under the Straits is 46.4% in 2017 and 72.5% in 2053 based on average failure rates for all pipelines. This is a far cry from the erroneous 1.6% figure calculated in the Alternatives Analysis.
√ Despite documented evidence of pipeline damage, the Dynamic Risk Alternatives Analysis fails to examine the causes of pipeline damage or its impact on Line 5.
The Alternatives Analysis states that bends found in the exposed underwater sections of Line 5 are of unknown origin but “may have been intentionally or unintentionally created as part of the installation process.” This statement is speculation on the part of the authors of the Alternatives Analysis. Records and data that are publicly available suggest that the pipeline was bent in multiple areas at least 26 years after the pipeline was installed. The type of bends and other damage found along the pipeline are consistent with damage created by gravity and strong currents. Original Bechtel documentation makes no mention of this damage. That this critical finding of damage was dismissed by the authors of the Alternatives Analysis without any investigation or explanation is puzzling. Moreover, of the 22 new screw anchors that Enbridge is currently requesting a permit to install along Line 5 in the Straits, five are to be located in areas where bends and other features point to pipeline damage.
√ Dynamic Risk based their probability of a pipeline rupture on average weather conditions rather than extreme conditions of high winds and waves.
Most people understand that structures don’t fail during nice weather. Wind and wave conditions in the Straits of Mackinac fluctuate greatly, yet Dynamic Risk removed from their analysis the most likely condition when a rupture would occur—during peak wind and wave velocity. This decision to use meteorological data from a period where “Wind conditions are fairly average compared to other years, without any particular high wind events or extreme situations” defies common sense. Excluding the very conditions that would be expected to lead to a rupture of Line 5 is neither explained in the Alternatives Analysis nor realistic. Peak water velocity in the Straits is estimated at least 20% higher than what Dynamic Risk evaluated.
"It's truly puzzling why Dynamic Risk would skirt widely-recognized best practices in their analysis and omit so many critical details from their examination of the rupture risk of Line 5," said Dr. Timm. "The glaring errors and omissions in this report disqualify much of the Alternatives Analysis as simply wrong."
