Solving a Locational Distribution Problem of Non-Toxic Solid Waste on the Island of Puerto Rico
The island of Puerto Rico is confronting a crisis in waste management due to inadequate management from the local government, the decreasing number of landfills available, high population density, and paucity of places for waste disposal. This research develops a least-cost model for the disposal and transportation of non-hazardous solid waste. Location-allocation (LA) and Geographic Information Systems (GIS) software are used to analyze the efficiency of the present pattern of waste allocation and to identify a near-to-optimal assignment of waste for the landfills in operation today and the landfills that will be open by 2008. The near-to-optimal models obtained from the LA analysis are compared to a regional system that has been proposed by the Autoridad de Desperdicios Sólidos (ADS) for the management of waste and with other waste-related infrastructure.
The LA analysis revealed that the present allocation of waste is not efficiently distributed. The total cost of the present allocation of waste is 99,011.5 tons (miles) per day, while the least-cost model cost would be 83,201.5 (tons) miles per day. The least-cost model for 2008 allocated only seventy-two of the seventy-six municipios on the main island, leaving highly populated regions and 2,207.5 tons of waste generated per day out of the analysis. Most of the waste coming from the northeast would be transported to Humacaos landfill (east). These results appear to be more economically efficient than other scenarios considered by the ADS. By 2008 most of the regions will be facing greater demands than landfill capacity. The scenario that presents the biggest savings is the LA model with twenty-seven landfills, while the model developed for 2008 provides better results than predicted by ADS, but the total distances values and cost are higher than the other scenarios evaluated. This suggests that more landfills might be needed by 2008 in order to save in operating costs. Based on these results recommendations are posed in relation to the location of waste-related infrastructure and possible regional make-ups, among others.
Advisor:Nina S.-N. Lam; Paul H. Templet; Craig E. Colten
School:Louisiana State University in Shreveport
School Location:USA - Louisiana
Source Type:Master's Thesis
Date of Publication:08/30/2004