ELECTRE III as a support for participatory decision-making on the localisation of waste-treatment plants

Locating an incinerator and a facility to store ashes and other wastes is a long and complex process in Italy. The District of Turin faced this situation by choosing a participative approach to the problem and by using multi-criteria (MC) analysis as a support for a specific phase of this decision process. A group of 45 decision-makers (local authorities and representatives from the different communities that were involved) worked together with a facilitator group for 16 months to identify the criteria judged relevant to analyse the consequences of the location of a plant. Two MC models—one for the incinerator and the other for the waste-disposal plant—were elaborated and an ELECTRE method used to compare sites and rank them with the aim of selecting the best sites to activate an Environmental Impact Assessment procedure. A team made up of analysts from different organisations supported this work from a technical point of view. This paper proposes an analysis of this participatory decision process and synthesises the difficulties and results of the MC decision aid intervention.