Decision making guidelines for mining historic landfill sites in Flanders

This study aims at showing how the United Nations Framework Classification for Resources (UNFC) can help to classify potential landfill mining projects with different levels of maturity, from exploration to production, under technical, socio-economic and project-planning aspects. Taking the example of three former landfill sites in Flanders general decision making guidelines regarding the future management of old landfills are provided. Using the ECLAR methodology for the evaluation (E) and classification (CL) of anthropogenic resources (AR), the individual projects, where clean land and/or materials are recovered, are mapped under the three-dimensional UNFC system. The Bornem project, yields a negative Net Present Value (NPV) of −17 Mio € (−44 €/t of excavated waste), i.e. the project is currently not economically viable. In case of changing key parameters the landfill has, however, reasonable prospects for future economic extraction. The Turnhout land development turned out to be economically viable with a NPV of 361,000 € (8 €/t of excavated waste). The Zuienkerke remediation project is at a too early stage to determine its socioeconomic viability. The main focus to compare and prioritize potential landfill mining projects in Flanders should be on (1) site specific conditions (e.g. landfill's composition, land prices), (2) project related factors (e.g. remediation required vs. resource/land recovery, selected technologies and project set-ups, private vs. public evaluation perspective) and (3) the timing of mining, considering future development of costs, prices, laws, available data and information.