Permafrost, Pipelines And Politics -- An Incompatible Mixture?

Early in January 2008 Gov. Sarah Palin of Alaska approved an application from TransCanada Alaska Co., LLC/Foothills Pipeline, Ltd to build a gas pipeline from Prudhoe Bay, Alaska to near Edmonton, Alberta, Canada. It remains to be seen whether the line, as envisioned, will be built.

The project faces several technical challenges, including the requirement that the gas must be chilled to prevent thawing the numerous underlying ice lenses in the permafrost soils. Chilling the gas, while resolving a likely subsidence problem, creates another. A chilled-gas pipeline creates an artificial heat sink that can freeze any water flowing under it. In dangerous, discontinuous permafrost soils where water can freely move, freezing could cause serious heave and lift the pipe above the surrounding terrain. Landslides from global warming on steep slopes then could destroy the pipe.

The Canadian National Energy Board (NEB) may not approve the proposed project. One reason for this disapproval could be that there is an alternative, less challenging route across northern Canada that likely would provide significantly greater benefits to Canada and to high value markets in the Northeast U.S. Several individuals (the author included) plan to request that the NEB consider an alternative northern route.

The alternative route goes offshore through the Beaufort Sea, the Amundsen and Coronation Gulfs, crosses Nunavut to the Hudson Bay, then offshore again to the base of James Bay. From that point, the route goes south through unfrozen sediments to major Canadian and U.S. markets. An illustration with this article shows arctic ice content and the other shows a map of the alternative route to the Northeast U.S. that avoids dangerous discontinuous permafrost zones. The alternative route has the following advantages:

1. Its overland segment is likely thaw stable for most of the route with low ice content soils representing probably 10-20% of the route vs. 50% and more in areas of an Alaskan route. Not as many engineering, construction, and maintenance problems.

2. The route avoids all areas of dangerous discontinuous permafrost which maximizes the potential for continual ice build-up under a chilled gas pipeline and resulting heave.

3. Minimum thickness of active layer (coldest permafrost).

4. High percentage of the route is offshore (the safest place for an arctic gas pipeline).

5. Shortest distance to major gas markets. (Not dependent on expansion of other pipelines to reach the major markets).

6. Most favorable onshore terrain (avoids mountains, earthquake zones, major river crossings, steep slopes, forests and discontinuous permafrost zones.)

7. Low snowfall along land portions of route (less construction downtime).

8. Less affected by global warming.

9. If the gas competes in New York, Montreal, and other eastern markets, it should obtain higher net-back wellhead prices. The route with the highest net-back price will result in the greatest long-term benefit to Alaska.

10. Lowest cost per mile and likely the shortest construction time.

11. Most efficient gas transportation (least fuel usage/mile).

12. Greater productivity per worker. Less unproductive portal-to-portal transportation time for workers.

13. Safest route for both workers and the pipeline.