The Pond 5 Tailings Impoundment at the Suncor Energy Oil Sands Mine north of Fort McMurray, Alberta, was turned over to the mine’s reclamation department in 2009 for closure. At the beginning of 2010, construction of a pond-wide coke cap, part of the proposed final cover, was begun. In the two years preceding construction of the pond-wide coke cap, the authors undertook extensive laboratory and field trials of a prototype coke cap.
This paper describes the theoretical and practical work done to formulate a viable and safe coke cap—in effect the cap that is now under construction across almost the entire pond. We describe field testing to characterize the tailings; laboratory testing undertaken to characterize the response of the tailings to planned construction procedure; and two prototype covers constructed in the winters of 2008 and early 2009 to test and confirm theoretical analyses and designs.