The evaluation of remediation technology: a case of multiple criteria decision making

Abstract

This thesis explores current decision making practices in the selection of remediation technology, with the aim that future decisions will be consistent, justifiable, open to inspection and able to withstand detailed scrutiny. No prior research has collated, compared or critiqued the various methodologies currently in use for the selection of remediation technologies, nor has there been any observation and/or critique of the decision processes used in a real case. This lack of knowledge was addressed through an extensive literature review and observation of a live New Zealand case (Site X) which provided first hand examination of current remediation decision making practices. This study trials and advocates the use of a decision making framework incorporating Multiple Criteria Decision Analysis and Visual Interactive Modelling in general, and the use of Visual Interactive Sensitivity Analysis (V.I.S.A.) in particular. The intent of the inquiry was also to research the nature and extent of site contamination in New Zealand; and provide a broad overview of remediation. The selection of remediation technology was found to be complex given the diversity of stakeholder interest, the size of the financial and environmental stakes, the existence of multiple (often intangible and conflicting) criteria, and the paucity and limitations of decision aids used currently in remediation problems. The decision making model used by the Site X Decision Team was typical of many found in the literature, in that there was a lack of attention to both procedural details and the tenets of Decision Science. However, the post analysis of the Site X model results revealed that the decision was robust, and also that V.I.S.A could provide insight into the decision dynamics in a manner which was not possible through traditional, non-interactive methods. The research demonstrates that V.I.S.A., which combines both the Simple Multi-Attribute Rating Technique and Visual Interactive Modelling capability, has the ability to provide a generic, appropriate, consistently applied methodology for use when developing a model for the selection of remediation technologies in New Zealand.