Selecting transfer station locations for large solid waste systems

Abstract

In a city with a population over 6 000 000, solid waste collection activities require a lot of attention. The resources used for collection and transport, trucks and labor, can be utilized more effectively if waste is transported to the disposal area via transfer stations. The location of transfer stations becomes especially important when the daily average of solid waste to be transferred is around 6 000 tons and disposal areas are at least 30 kilometres away from the metropolitan. A general mathematical programming approach with four stages is proposed to determine the locations of transfer stations. Certain modifications are required for the case considered, all resulting in a model which identifies the trade-off between costs of carrying the waste by different transportation modes. The identification of the trade-off requires the estimation of relative cost values rather than individual costs. On the basis of the results obtained, economic feasibility of different alternatives can be evaluated upon the availability of cost information. The application of the model to İstanbul is summarized together with the details of analysis.