Integration of life cycle assessment with environmental, social and economic impact analysis methodologies for the selection of `sustainable' waste management options

This thesis describes a framework for a decision support tool which can assist the assessment of options/scenarios for the integrated management of municipal solid waste (MSW) within a local government area (LGA). The framework is applicable to MSW as a whole or to a MSW component. To demonstrate its application, the framework was applied in this thesis to the residential organic waste component including sewage sludge.

The work was initially focused on local government (i.e. municipal councils) in the state of Queensland (Australia). However, it is broadly applicable to LGAs anywhere in the developed countries. The goal was to achieve waste management practices which address needs of sustainable society (or briefly: 'sustainable' waste management) by balancing global and regional environmental impacts; social impacts at the local community level; and economic impacts. The framework integrates Life Cycle Assessment (LCA) with other environmental, social and economic tools. For this research, social and economic impacts were assumed to be similar across developed countries of the world. LCA was 'streamlined' to address the researcher's concerns about LCA complexity impeding a practical and operational application of LCA to the evaluation of integrated waste management practices.

For this process, 'spatial resolution' was introduced into the LCA process to account for impacts occurring at the local and regional levels - considerations usually neglected by conventional LCA. This was done by considering social impacts on the local community and by use of a regional scaling procedure for LCA data for emissions to the environment which may have impacts at the regional level.

The integration followed the structured approach of the Pressure-State-Response (PSR) model suggested by OECD (1993). This PSR model was modified/extended to encompass non-environmental issues and to guide the process of applying multiple tools. For this process, a clear relationship between 'pressure', 'state' and 'response' at the community, regional and global levels was required.

The framework primarily focussed on decision analysis and interpretation processes. Multi-Attribute Utility Theory (MAUT) was used to assist with the integration of qualitative and quantitative information. MAUT provides a well-structured approach to information assessment and facilitates objective, transparent decisions. The commercially available decision analysis software package Criterion DecisionPlus 3.0 developed by InfoHarvest Inc (1999) - based on MAUT - was also utilised as the platform for the framework developed in this research.

Finally, this thesis describes a case study involving the evaluation of a number of options for integrated organic waste management for a rural LGA in Southeast Queensland. Although refining and testing of the framework was the primary objective of its application to the case study, the case study also provided valuable and interesting results. The results are of use in the development of alternative strategies for managing residential organic wastes. This is specifically important because the integrated management of all organic wastes (including food wastes) has been neglected over many years and most municipal councils are now having to make difficult decisions about alternatives to landfill disposal.