In the 6 recent years, there has been increasing interest into municipal solid waste (MSW) valorization, owing mainly to the hierarchy established by the new Waste Framework Directive 2008/98/EC (WFD), aiming at minimizing volumes of disposed waste.
There has also been a growing inquisitiveness on what will the fate of existing landfills will be, especially of the closed ones. Their total number is unknown, but there have been reports stating that in the EU exist over 150.000 old landfill sites and dumps, most of them abandoned.
The environmental problems that stem from the existence of both closed and operational landfills are multiple:
the abandoned landfill or dump sites need stabilization and rehabilitation
they are considered as environmental and health threats, and contaminants are usually abundant in leachate and air emissions
they usually occupy land close to existing settlements
landfill sites are unintentional storages for considerate amounts of raw and soil materials
The facts have recognized in the last 5 years by NGOs (Friends of the Earth Europe, 2009), the scientific community (Van Acker et al., 2010; Geysen, 2010) and the European Parliament (Resolution of 13 September 2011 on an effective raw materials strategy for Europe, 2011/2056(INI).