A survey of life cycle approaches in waste management

Life-cycle thinking and life-cycle approaches are concepts that are getting increased attention worldwide and in particular in EU Policies related to sustainability. The European Commission is launching a number of activities to strengthen life-cycle thinking in policy and business. EU policies aim to decrease waste generation through new waste prevention initiatives, better use of resources and shift to more sustainable consumption patterns. The approach to waste management is based on three principles: waste prevention, recycling and reuse and improving the final disposal and monitoring. In particular, concerning the prevention and recycling of waste, the definition of a waste hierarchy should be the basis for the prioritisation of waste management options. The benefit of using Life Cycle Assessment (LCA) in analysing waste management systems is the provision of a comprehensive view of the processes and impacts involved. However, it is also clear that the studies will always be open for criticism as they are simplifications of reality. Moreover, in order to become the LCA, a leading tool within businesses and government to understand and manage risks or opportunities related to waste management and treatment technologies, there are methodological choices required and a number of aspects that still need to be worked out. It is therefore important to review open and grey literatures, EU guidelines, relevant environmental indicators and databases for the waste sector and data easily usable in waste policy decision-making, with an agreed approach and methodology based on life-cycle thinking. The following survey gathers and describes the existing guidelines and methodologies based on life-cycle thinking and applicable in waste policy decision-making.

This survey is focused on three main issues: definition and categorisation of waste streams and technologies; review and interpretation of existing waste-specific guidelines and tools; identification of specific key environmental performance indicators for the waste sector. Considering that a wide part of municipal solid waste is biodegradable and that their degradation is the main cause of greenhouse gas emissions in the waste management sector, considerable attention has been paid to biodegradable municipal waste.

The survey shows that general technical guidance documents should take into account the following key issues: how to categorise waste streams, how to develop a waste hierarchy from a life-cycle point of view, how to include any possible new waste treatment technologies and to take into account local and waste-related factors. Moreover, the survey summarises the generic/default values that could be used for waste-related key parameters when insufficient information/data are available. The survey identifies some key environmental performance indicators in the waste sector. The analysis of existing waste-specific guidelines and tools leads to a list of available methodologies and foreground/background environmental data sources that satisfy specific data constraints (origin, time-related coverage, geographical coverage, technology coverage).

The survey points out the need for strategic guidance documents for policy makers with quantitative examples to define the waste hierarchy. Depending on the characteristics of the specific cluster or area, such as climate, population density, etc., these documents should be integrated with quantitative considerations related to cost and social dimension, as complementary information to the environmental aspects of sustainability in waste management in order to address the preferable options to be considered for the definition of a local waste hierarchy.

The survey shows that a considerable number of decision models and methodologies for the integration of life-cycle thinking into waste management have been developed for several waste streams and waste-management and treatment technologies. This leads to the need of a critical analysis of the existing guidelines and tools.

A survey of life-cycle approaches in waste management has been presented in this paper. The analysis of specific waste streams and the integration of different environmental tools supporting the choice between different waste-treatment options could be taken into consideration for further work.