Design of an urban solid waste transport system

The objective of this article is to present the design of a non-hazardous solid waste collection system in an urban context. The system is formed by three activities: optimal location of transference centers, optimal location of sanitary landfills, and flow distribution over the urban transport network in order to minimize the total cost for the whole operation. The total cost is formed by transportation costs and opening costs for centers and plants. A strategic mathematical model is developed to simultaneously solve the location and distribution problems described above. The model is a mixed continuous-integer programming model that gives the number and location of transfer centers and sanitary landfills as well as the flows and routes followed by the waste from the generation centers (typically residential areas and industrial zones) to the final destination in the transformation plants. The model was applied to the city of Santiago, Chile. The model was solved using a heuristic approach which gave a solution less expensive than the one currently being used in the city.