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Earthquakes and Keystone XL

November 22, 2010

Some interesting back and forth recently about the risk to Keystone XL from seismic activity along the route, especially in light of recent earthquakes, including one in the Schuyler area, about 65 miles northwest of Lincoln, that measured 3.3 on the Richter scale. Schuyler is along the route of the Keystone I pipeline, which is already operational. Questioned about quakes and the pipeline, TransCanada representative Jeff Rauh said:

both Keystone and the proposed Keystone XL “have the toughness and flexibility to deal with those events, and they’re designed to operate safely in the event of an earthquake.”

This is an interesting assertion in light of the Draft Environmental Impact Statement conclusion about seismic activity:

Based on the evaluation of potential seismic hazards along the proposed ROW, the risk of pipeline rupture from earthquake ground motion would be considered to be minimal.  The proposed route would not cross any known active faults and is located outside of known zones of high seismic hazard.

So the risk from seismic activity is minimal, but the pipelines are “designed to operate safely in the event of an earthquake.” Is Rauh saying that the pipelines are overdesigned to handle a risk that TransCanada considers minimal? Or is he saying that nothing could ever go wrong with these pipelines, regardless of the mounting obvious risks?

Further doubts were raised in the DEIS comments submitted by a large coalition of route state organizations: Friends of the Niobrara, Honor the Earth, Intertribal Council on Utility Policy, Nebraska Chapter of Sierra Club, Nebraska Environmental Action Coalition, Nebraska Sustainable Agriculture Society, Northern Plains Resource Council, Plains Justice, Prairie Hills Audubon Society, Wachiska Audubon Society, and Western Nebraska Resources Council. The pipeline safety portion of the comments was drafted with the assistance of expert independent consultants and represents important considerations neglected by the DEIS, including the following discussion of risks from landslides and seismic activity:

Various critical issues concerning the Keystone XL pipeline’s specific route selection in the DEIS need further clarification and evaluation. Steep unstable slopes are insufficiently analyzed and avoided. Table 3.1.4-2 identifies areas of the proposed pipeline route that are “Areas with High Landslide Potential Crossed by the Project.” The impression that this table gives is that there are over 360 miles of pipeline routed in areas with high landslide potential.  No pipeline is capable of withstanding the forces of many tons associated with a massive landslide.  The DEIS states that “Keystone has considered landslide potential in its routing work and has selected crossings of these areas where the landslide potential is considered minimal.” Further detail is warranted to put this concern to rest given that landslide related failures usually end up as pipeline ruptures, with very large, high rate releases.  Table 3.1.4-2 needs to be expanded in further detail to identify those areas of the pipeline route where steep landslide would be of the “breakaway” type rather than slight or limited earth movement or settlement.  Pipelines are usually designed to handle slight earth movement or settlement.  A pipeline elevation profile should quickly help in determining breakaway landslide potential in those areas identified as steep unstable slopes.  Breakaway landslides place rapid and excessive abnormal loading forces on the pipeline.  Pipelines placed in breakaway landslide areas need to be routed out of these landslide areas.

The analysis of seismic activity at discounts almost entirely any risk from earthquakes along the route. These claims seem ignorant to local residents who have experienced repeated seismic activity along much of the route, including in some of the most biologically sensitive areas such as the Nebraska Sand Hills. Table 3.1.4-1 finds no “High Seismic Hazard” along the route, defined as “peak ground acceleration with 2 percent probability of exceedance in 50 years >0.5 g.” The studies cited are compilations of faults, not seismological analyses or projections of seismic risk in the area. A more thorough analysis should be performed in light of the grave risk to pipeline safety posed by active geologic faults.

If Keystone I and Keystone XL really can withstand seismic activity, people who live near the route deserve some proof of that. So far, TransCanada has produced nothing but bland assurances.


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