In just one week Aarsleff rehabilitated three outfalls for Sønderborg Municipality in the South of Denmark.

Because water was penetrating into the pipelines, it was necessary to install two liners in each pipeline instead of just one. ”The first liner is closed at the pull end. When this liner is in place, we insert another liner into the first one. The second liner is installed with water pressure as is the normal procedure”, explains Contract Manager Peder Dahl-Nielsen.

The water pressure makes the two liners expand and press against the existing pipeline, thus pushing out the water that has penetrated into the pipeline.

The three outfalls comprised two 50m long pipelines of respectively DN450 mm and DN800 mm, and one 65m long DN600 mm pipeline.