The application of LCA impact assessment to environmental performance indices : a comparative study

Abstract

A wide variety of assessment techniques are presently available to quantify the environmental performance of an organisation. They are predominantly site- or area-specific, making them sensitive to differences in the environmental capacity of an area, and they exclude a number of global impacts. A more generic level-plane assessment tool, which quantifies the environmental burden, may therefore be needed to make a valid comparison between organisations. Furthermore, the generic process data used in these assessment tools, to inform policy decisions on a material or product, does not recognise the potential variation in burden of a sector. This thesis develops a corporate level-plane assessment tool using the techniques available from Life Cycle Assessment. This generic tool, the Total Environmental Potency Index (TEPI), is then compared with the Environment Agency's Integrated Environmental Index (IEI), to assess the significance of site location on compliance based site-specific indices like the IEI. The two indices are compared using realworld emission data from seven industrial collaborators in five sectors. Two of these, paper manufacture and power generation, are used to assess the potential variability among processes within the same sector. The potential use of the indices is also determined by examining the accessibility to the required data at each of the participating companies. The results show that site location significantly affects the IEI and that the TEPI can provide a useful generic impact assessment tool to compare sites from different locations or sectors. The burdens from processes within the same sector were highly variable, suggesting that process-specific data will be important if valid policy decisions are to be made in the future. The TEPI and its categories can provide a standard format for aggregating and presenting the required emission data in a way that protects its commercial sensitivity. Although the accessibility to this data was low to moderate, the potential for deriving emission data using mass balance studies was high, with a large amount of accessible input data available. The implications of these results for the use of internal and external impact assessment techniques within an organisation are discussed. A framework is provided to guide the use of process data and impact assessment techniques in the wide range of assessments made by organisations to manage and report on their environmental performance. Finally, the experiences gained from using the IEI and TEPI are used to make recommendations for their improvement, and further development by research.