Applying a decision support system tool to the integrated design and operation of a landfill.

摘要

Up until about the mid-1970's, landfills were still treated as garbage dumps even in some major centers throughout North America, and the rest of the world (Bolton, 1995). Over the last fifteen years, a significant shift towards a more sophisticated and technologically applied approach to landfill design and operation has occurred. Landfilling of solid waste has taken on a new complexity with terms such as bio-reactor being used to describe new methods of managing solid waste, while at the same time focusing on sustainable methods to handle the organics portion of the waste stream and its subsequent reuse as compost or other environmentally friendly material. (Reinhart and Townsend, 1998).;The application of operational research tools to optimize landfill design and operational components is in its infancy. Although these tools have been used to help address environmental situations for some time, including waste management systems, applying them in an integrated fashion to the landfill design and operations area is quite a new application.;These management tools have the ability to assist decision makers with optimizing landfill capacity, minimizing human health and environmental issues related to worksite safety, traffic flow issues, as well as air and ground water contamination, and address cash flow issues related to revenue and profitability. In addition, these same tools can help address socio-political and other intangible public perception concerns that are difficult to quantify.;A commercial software program based on the analytical hierarchy process (AHP) has been utilized in conjunction with Excels Monte Carlo simulation program to create an integrated decision making tool utilizing landfill design and operating parameters. A sensitivity analysis of the AHP model under nine different landfill scenarios is described and discussed. As well, in conjunction with Excel's monte carlo simulation, the model is applied to a specific case study, using design and operating parameters for a specific convertional landfill scenario. The model is used to predict future financial landfill scenarios, the impact changes to specific parameters have on the landfills revenue, costs, and profits. The benefit of parameter prioritizing, is not only in the integration aspect of landfill design and operations in a way that impacts bottom line of operating a landfill. This specific model also provides planning flexibility by introducing "what if" scenarios that can be produced modeled quite easily, and providing quick results.;However, as new and more sophisticated methods are developed to address sustainable landfilling practices, it is also becoming apparent that the infrastructure required to design, build, operate, and maintain these new technologies is also becoming more challenging. Notwithstanding the fact that the more space the infrastructure consumes within a landfill, the less space there is for landfilling, and consequently, reduced capacity for landfill. In that light, it is evident that, as in other areas of the waste management field, be it solid waste collection, recycling, or facility siting, applying operational research modeling tools to this area is not only possible, but necessary.