Optimizing location of solid waste transshipment station in Rayong, Thailand

• Integer programming was applied to solve the location problem, incorporating unloading and loading times at garbage stations. • Sensitivity analysis using real-world data identified the optimal location for solid waste transshipment in Rayong, Thailand. • Economic evaluations demonstrated the financial feasibility of establishing the new solid waste transshipment facility. • The study offers an integrated approach combining operational efficiency with economic viability in waste management. Rayong is a model province for solid waste management in Thailand, with the Center of Integrated Solid Waste Management (CISWM) situated in Muang district handling around 1,000 t per day. The large amount of solid waste comes from the 62 local government organizations (LGOs) in Rayong, with 36 of these directly dispatching their solid waste to CISWM, while for the remaining 26 LGOs, the solid waste is first transshipped via a solid waste transshipment station in Klang district before being dispatched to CISWM, due to the long distance otherwise involved. The amount of solid waste is expected to increase in the future and the Rayong Provincial Administrative Organization (RPAO) wishes to decrease the associated transport costs. Therefore, this paper optimized the location of a solid waste transshipment station for the RPAO by forecasting the number of loads of solid waste from the 62 LGOs for the next 30 years. An integer programming model was developed to minimize the total system costs, combined with comparative economic analysis. Based on the results, Pluak Daeng district was the optimal location to establish a new solid waste transshipment station. Furthermore, it was worthwhile for the RPAO to invest in this additional solid waste transshipment station.