methane, landfill, odor, buffer


With population growing every year, more and more people are looking for places to live. This can lead to construction of houses near and around landfills. As homes get closer to landfills, the odors these landfills produce become more of a problem, and lead to an increase in odor complaints. Modeling these odors and recommending odor buffer distances will help determine limits on how close to landfills new homes should be allowed. This should help reduce future odor complaints. To solve this problem one must accurately estimate odorous gas emissions from the landfill. Often odors can be indicated by methane emissions. A new technique using hundreds of ambient VOC concentrations, which are taken from landfills on a quarterly basis, was used to invert and solve the Gaussian dispersion equation for methane emissions. In this technique, Voronoi diagram theory was used to automatically locate numerous point sources for optimal positioning relative to receptors. The newly solved methane emission rates can now be input into a dispersion model, and the resulting methane concentrations used as surrogates for odors around the landfill. One of the most important steps in the analysis is to determine which model is best to use for odor modeling. There are many considerations that go into this decision, such as how much time it takes to run the model, how accurate the model is, and how easy the model is to use. Two current models CALPUFF and AERMOD were compared. In the modeling, methane was used as a surrogate for the odors. Since landfills handle many different combinations of waste, the type of odor may vary from landfill to landfill. In this test case, H2S was assumed to be the main contributor to the odor emitted from the landfill, and the H2S-to-methane ratio was used to estimate downwind H2S concentrations from the modeled methane concentrations. Once an air dispersion model is selected, it can be used to model odors and to develop a graphical screening method to show where these odors are most likely to occur and how strong they will be. This can be used to determine how close to a landfill homes can be built without having significant odor impacts bothering these new residents. Also, this tool can be used for improving landfill gas management. Several example scenarios include the possibility of not enough soil cover placed on the waste, leaks from an aging collection system, or cracks in the collection piping created by the settling of waste.


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Graduation Date



Cooper, C. David


Master of Science (M.S.)


College of Engineering and Computer Science


Civil and Environmental Engineering

Degree Program

Environmental Engineering Sciences








Release Date

May 2009

Length of Campus-only Access


Access Status

Masters Thesis (Open Access)