Holistic assessment of a landfill mining pilot project in Austria: Methodology and application

Abstract

Basic technical and economic examinations of Austrian mass waste landfills, concerning the recovery of secondary raw materials, have been carried out by the ‘LAMIS – Landfill Mining Austria’ pilot project for the first time in Austria. A main focus of the research – the subject of this article – was the first devotion of a pilot landfill to an integrated ecological and economic assessment so that its feasibility could be verified before a landfill mining project commenced. A Styrian mass waste landfill had been chosen for this purpose that had been put into operation in 1979 and received mechanically–biologically pre-treated municipal waste till 2012. The whole assessment procedure was divided into preliminary and main assessment phases to evaluate the general suitability of a landfill mining project with little financial and human resource expense. A portfolio chart, based on a questionnaire, was created for the preliminary assessment that, as a result, has provided a recommendation for subsequent investigation – the main assessment phase. In this case, specific economic criteria were assessed by net present value calculation, while ecological or socio-economic criteria were rated by utility analysis, transferring the result into a utility–net present value chart. In the case of the examined pilot landfill, assessing the landfill mining project produced a higher utility but a lower net present value than a landfill leaving-in for aftercare. Since no clearly preferable scenario could be identified this way, a cost–revenue analysis was carried out in addition that determined a dimensionless ratio: the ‘utility – net present value quotient’ of both scenarios. Comparing this quotient showed unmistakably that in the overall assessment, ‘leaving the landfill in aftercare’ was preferable to a ‘landfill mining project’ in that specific case.