Construction and demolition waste management – a holistic evaluation of environmental performance

• The performance of construction and demolition waste management system was assessed.
• MFA, LCA, ELCC and BAT approach were applied.
• Critical fraction for 70% recycling target is wood, currently recovered as energy.
• Different methodologies gave a diversified view of the possibilities to develop the system.
• Holistic approaches are needed for decisions on sustainability of waste management.

A growing amount of construction and demolition waste (C&DW) is produced in Europe each year. Increased recycling of C&DW is required by the EU Waste Framework Directive, targeting at 70% recycling of non-hazardous C&DW by 2020. The aim of the study was to assess the performance of the common Finnish C&DW management system against this target, thus identifying the environmental and economic impacts of the system and the effects brought about by changes in the waste composition. In this study, a combination of different methodologies was applied to evaluate holistically the performance of the C&DW management system: material flow analysis (MFA) was employed to assess material and energy recovery rates, life cycle assessment (LCA) was utilised to evaluate climate change impacts, and environmental life cycle costing (ELCC) was used for measuring the costs. In addition, the applicability of the best available technology (BAT) approach for developing the efficiency of the waste management system was scrutinised. Thus, aligned with the empirical aim of assessing the performance of Finnish C&DW in reference to the EU Waste Framework Directive, the theoretical aim of the study was to test how the employment of different assessment methodologies affects the performance results of the C&DW management system.According to the results, the overall system produced environmental benefits and was economically profitable, but was far behind the target of recycling 70%. Based on the assessments, the EU Waste Framework Directive target will not be achieved, even with the likely changes in waste composition. Thus, major changes will be needed to source separation and recovery within the system, e.g. by finding recycling concepts for waste wood without decreasing the environmental and economic benefits of the system. The employment of different methodologies gave a diversified view of the possibilities to develop the system. The metal treatment performed well in all assessments; hence improvements to it would not benefit the system notably. For wood the results were controversial, since the energy recovery generated environmental and economic benefits, but did not increase the recycling rate. Material recovery concepts should be developed, but simultaneously the environmental and economic benefits should be retained. Miscellaneous waste had the potential for increasing recycling and avoiding costs and emissions. Mixed waste was identified as the worst fraction in relation to climate change impacts, costs and material recycling. Applying the BAT approach showed that BAT for waste management needs to be based on system-level rather than installation-level assessments.This multi-methodological assessment of C&DW management showed the need for analysing the environmental performance of a system from different perspectives before decision-making. In general, the recycling of waste generates greater environmental benefits than energy recovery, but this may not always be the case. Regional differences in operations and waste composition may support arguments for differing recycling targets in different regions.