Durham Region doubly at risk: Thin walls and highest concentration of water crossings

This analysis is based in part on a chart of watercrossings released by Enbridge in response to an information request by Equiterre which showed that Durham Region had the highest concentration of watercrossing over the whole line.

Note: on this and subsequent docs, Durham Region extends from approx. Kilometre post 3096 to Kilomtre post 3163.

It is also based on a spreadsheet prepared since the hearings by Darko Matovic, a professor at Queen's University which shows the wall thicknesses of the pipe along its length.

From this wall thickness spreadsheet, it was possible to extract that the wall thicknesses in Durham are overwhelmingly 1/4" or.281"

Wall Thickness Total Length  
0.25" 41.9 km 61.5%
0.28" 24.3 km 37.5%
0.50" 1.9 km 2.8%

Superimposed on the wall thickness spreadsheet is the areas that Enbridge has designated as 'high consequence'. They come in 2 categories - those areas through which the pipe passes and hence are directly impacted, and areas which would be affected by subsequent gravity flows or spray from a leak.

In addition, it was possible to map the 12 acknowledged leaks on Line 9b:

  • 7 leaks occurred where the thickness was .25"
  • 3 leaks occurred where the thickness was .281"
  • 2 leaks occurred where the thickness was .312"

While the sample here is very small, a trend is evident than thinner pipes are more likely to leak.

Conclusion: Durham Region is doubly at risk from the lowest grades of pipe and the highest concentration of water crossings