Sedidepot Secure land based storage of contaminated marine and river sediments

Dredging fishing harbours, commercial ports, marinas and canal and river channels presents a major challenge, with many different operations being involved in the process of maintaining vessel draft clearance. Significantly large volumes of material, amounting to more than one million cubic metres in Var and several million cubic metres in Brittany, will have to be extracted in the years ahead to ensure optimum navigational conditions. Most of the dredged material consists of sediments which are safe and pose little pollution threat. In some zones, however, the presence of perceptible levels of contaminants makes it impossible to dispose of the dredged sediments at sea, raising the question of what to do with these polluted materials. SEDIDEPOT aims to provide an answer by examining the potential of land-based storage of pretreated dredged sediments.

The project will determine the conditions required for this waste to be stored in a way that meets both environmental and statutory requirements. The technical specifications for single-product storage chambers will be drawn up following laboratory studies and modelling relating to mechanical and hydrodynamic behaviour of sediments, leaching behaviour, liquid effluent, gas and odour emission monitoring, etc. Units lined with waterproof materials and equipped with a means of collecting effluents will be constructed at an experimental site and will be used exclusively for contaminated sediments. Full specifications for these units – size, securing, etc. – will be brought together in technical guidelines aimed at industry professionals and local authorities and detailing the design and operation of single-product storage chambers for pre-treated contaminated marine and river sediments.
The project will be developed in collaboration with the Ministry of Sustainable Development, Ecology and Planning (MEDAD: Ministère de l'Ecologie, du Développement et de l'Aménagement Durables) and forms part of the second phase of the SEDIMARD Programme launched in 2002 by Var Regional Council. SEDIMARD is a joint research initiative which is examining the processing of contaminated marine sediments and associated storage and development procedures, and which involves the ports in the Bretagne and PACA regions, as well as funding partners such as the Environment and Energy Efficiency Agency (ADEME: Agence de l'Environnement et de la Maîtrise de l'Energie) and the Water Agency (Agence de l'Eau).