Allocating Refuse Bins for Selective Waste Collection, A Case Study * Joaquín BAUTISTA a , Jordi PEREIRA b a Nissan Chair, Escola Técnica Superior d’Enginyeria Industrial de Barcelona. Universitat Politècnica de Catalunya, Barcelona, SPAIN b Departament d’Organització d’Empreses. Universitat Politècnica de Catalunya, Barcelona, SPAIN Abstract One of the problems found in Municipal Waste Management is the allocation of refuse bins to different collection areas where waste (glass, paper, plastic, organic material) is left by the citizens. The relationship between the studied problem and the apportionment of seats in a parliament is tackled and it is used to develop an ant algorithm approach to solve the problem. The algorithm is then compared to an exact procedure for a real life instance found in the metropolitan area of Barcelona. Key words: Location, Allocation, Integer Programming, Heuristics 1 Introduction Municipal Waste Management deals with the design, management and control of systems oriented towards the return and treatment of disposable goods, as well as the recovery and recycling of containers, bottles, packages and other forms of waste. Proper recovery of waste has gained importance in waste management due to social concerns. Municipal waste is not only a great source of recyclable goods, but it is also the nearest source of waste to citizens, more and more socially aware of their importance. Additionally, waste generation has increased during last years. For instance, the OECD has reported an increase of municipal waste generation per capita from 1990 to 2000 ranging from a 4% increase in the US to 26% in the EU. This increase, which has been continuous in recent years, generates serious problems not only during the collection phase, but also in the subsequent treatment phases. Those facts have been reflected in government legislations. For example, in the EU, a growing body of community directives based on the framework given by directives 75/442/CEE, 91/156/CEE and 94/62/CEE obliges its members to recover and recycle many products and components (e.g. containers, glass, paper, plastic, consumer goods, automotive components, electronics, etc…), as covered in the case of Spain by the July 15, 6/1993 and April 21, 10/1998 royal decrees. * This paper was not presented at any other revue. Corresponding author J. Bautista. Tel. +34934011703. Fax +34934016044 Email addresses: joaquin.bautista@upc.edu (Joaquín Bautista), jorge.pereira@upc.edu (Jordi Pereira).