Background Construction activity in the metropolitan area of Finland, including the southern Uusimaa region, generates huge amounts of loose, excavated soil. In many cases this is soft clay, which is difficult to use and is usually discarded. The total amount of soil material discarded in Finland is estimated at some 20-30 million tonnes/yr. In Uusimaa alone, the figure is some 4 million tonnes/yr. One of the main problems associated with this discarded soil is the shortage of available storage space. This is a problem in many densely populated regions in Europe. As a result, soil is being transported over longer and longer distances. In Uusimaa, it is currently transported between 200 and 500 km, which generates more than 2 tonnes of CO2 per 75 tonne truck load. This could amount to 120 000 tonnes of CO2/yr. The economic costs are also high, with transport alone costing from €2 million-4 million/yr. Objectives The project aims to demonstrate that it is possible to convert discarded soil into valuable secondary materials with civil-engineering applications. Specifically the project will provide the authorities with the tools and know-how to improve existing legislation so that it is not an obstacle to the appropriate use of secondary materials in construction. The project will also seek to determine the best possible solutions for the stabilisation of discarded soils, using regionally sourced commercial and by-product additives (such as fly ash). Finally, it aims to establish the optimum mixing of soil and stabilisation materials for different applications. Evaluation with the help of environmental life-cycle assessment, life-cycle cost assessment and follow-up of the pilots will verify the technical, environmental and economic feasibility. Expected results: The project will identify at least four civil-engineering applications for discarded soils and verify the feasibility of using these soils as construction materials; It will develop a model for environmentally-sound and cost effective procedures for using secondary and other materials; Landfilling and transport of discarded soils will be reduced and consequently, emissions of greenhouse gases will be reduced and the quality of the landscape and groundwater improved; The reduction in transport related greenhouse gas emissions could be some 1.2 million tonnes CO2/yr; Landfill costs in Europe could be reduced by more than €27 billion/yr; and The cost of construction in Europe could be reduced by some €3.5 billion/yr.