Background The annual volume of dredged materials in the European Union is estimated at around 200 million cubic meters. An essential part of these sediments are contaminated with pollutants like tributyl tin (TBT). As it is hazardous, the material cannot be easily disposed of without risking long-term negative effects on the environment. The large volumes of material generated pose a significant problem for the economic and technical feasibility of its treatment and disposal. Objectives The STABLE project aimed to demonstrate technically, economically and environmentally viable treatment methods for stabilising dredged materials. Following treatment of contaminants like TBT, dredged materials were to be reused as raw materials for infrastructure works, such as example harbour extensions. The new processing methods were designed with the aim of treating large volumes of contaminated materials. Once implemented and demonstrated, it was anticipated that the techniques could be easily adapted for infrastructure development in estuaries and coastal regions. Results The STABLE project succeeded in its aim to develop and demonstrate the potential of stabilising dredged materials. The project developed recipes to mix dredged sludge, fly ash and cement to make a stabile, non-leaching mixture, which can be used in infrastructure construction instead of virgin raw materials. The stability of the mixture is based, at this stage on laboratory tests simulating a time period of 20-30 years. The project applied an "environmentally friendly" dredging method utilising a new type of crab, which was GPS-steered enabling a very precise dredging, i.e. the masses dredged could be surveyd very closely quantity wise. Binder recipes for mixing contaminated sludge with cement and fly ash were developed and applied in practical tests. Results confirmed the recipes’ ability to create stabile, non-leaching sludge which could be used in infrastructure construction. Stablisation equipment was also developed, which was able to treat large volumes of sludge and ingredients in short time. This equipment seemed to be a success and worked effectively as planned. The samples were tested for strength development, water permeability and leaching of contaminants and the results indicated that the stabilised structure is going to meet the environmental permit conditions with respect to the water permeability and leaching of contaminants. Full verification of the project outcomes’ long term stability requires a long follow-up period. Nevertheless, stabilisation process equipment developed by the project proved efficient and reliable to treat large volumes of sludge. This new approach and technology that was developed by LIFE project is considered to offer good opportunities for transferability throughout the EU. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).