Peter Van den bossche (DEME Group) presented “Cleaned sludge gets a second life in nature building project - case Bird rock”.

This project is located in the port area of Den Helder (Netherlands) and aims to unite the needs of industry and nature.
In this area a soil and remediation plant ‘t Oost is located with need to dispose sediments and soil.  Due to its unique location there is also a need for refuges for (small) wading birds and safe breeding grounds.  
These needs created the opportunity to develop an bird rock of about 2,3 ha allowing the reuse of 90,000 m3 contaminated soil and sediments and 35,000 ton of immobilised concrete.   A specific procedure was used to build the walls and roof of the rock, see presentation.  The roof was made with 0.5 meter immobilised material, shells were placed on top to recreate a tidal flat (flood line habitat for the birds).  
After one year more than 500 birds from 13 different species have colonies the bird rock.  This unique project indicates that industry and nature can get together.  

Want to know more? You can find the presentation here