Interim cover



Interim cover has a task to give the tailings pond surface appropriate shape and to squeeze by its weight water out of tailings.
Up to 1.5 million cubic meters of different material: e.g. oil shale ash, radioactively contaminated soils, “Swedish ash” left from oils-shale process activities in 1930s, was used to build up the interim cover.

Excavation of oil-shale ash for interim cover from the eastern ash depository.

Clearing the “Swedish ash” area. This material was also used for interim cover construction.

Clearing the eastern ash depository.

First terraces of the oil-shale ash interim cover on the tailings pond surface.

Elevation of the interim cover is at its highest spot in the middle of the pond reaching 13 meters.

Tailings pond in 1995.

Tailings pond in 2002.
Compaction of the interim cover.
Finished interim cover in autumn 2004.

  General concept
  Dam stabilisation
  Trench and diaphragm wall
  Interim cover
  Surface reshaping
  Final cover
  by HansaNet
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