Background In the European Union, landfilling of municipal solid wastes remains the principal waste management option. Landfill criteria and procedures are regulated by annex II of the EU Landfill Directive (1999/31/EC) and by the article 16 of the Council Decision (2003/33/EC) establishing criteria and procedures for the acceptance of waste at landfills. In 2007, the European Commission (DG Environment) started a project to exchange information and discuss the EU legislation on waste landfilling, in order to prepare more effective co-operation and control of how it takes place. The final report highlighted a gap in the implementation of the legislative documents. Within this framework, it is clear that more precise definitions are required concerning management requirements, particularly for landfill subcategories, such as pre-treated organic wastes. Objectives The project aims to demonstrate the environmental (particularly in terms of biogas production) and economic performance of a landfill for lesser reactive, biologically treated waste (pre-treated organic wastes) compared with a conventional landfill. It aims to control the moisture of the pre-treated organic waste, using innovative and monitored liquid injection, in order to shorten and temporarily concentrate the biogas production. The projects results will be useful to decision-makers for the definition of one of the non-hazardous landfill subcategories foreseen by the Landfill Directive. Expected results: The main expected result is an increase of biogas production of 20% in the cell at the landfill where the demonstration will be carried out, compared with conventionally managed landfill. Other outputs include: Creation of a methodology for setting up and implementing the system; Creation of a database containing all the monitoring data; Five technical publications aimed at landfill managers.