Using Odor Panel Data to Enhance Odor Dispersion Models - Reality Checks Provide Better Results

摘要

Dispersion modeling is a powerful tool used by engineers to identify odor sources at wastewater treatment facilities (and other industrial and commercial facilities with sources of odor) and to prioritize which sources produce the most significant offsite impacts. Dispersion models like AERMOD and CalPuff are used frequently to assess odor impacts in offsite areas and are also used to project the impacts of apply new or additional odor control to key sources. However, like any model, there are limitations to the desire to apply dispersion model outputs to real-world situations. This occurs because of several reasons, such as fluctuating odor emissions from sources, modeling of only one compound when others may contribute to odor, or modeling odor when some sources are in fact more odorous than others. Furthermore, the output of odor dispersion modeling is inherently conservative, in that it shows worst-case meteorological conditions over what is often a period of 5 years of meteorological data. The result of these issues and conservativism can present problems when sharing the model outputs (in particular odor contour plots) with the general public. This paper provides an overview of how odor dispersion modeling is used, and offers three "reality check" potential enhancements that can provide modelers with tools to either reduce the model run time (which can be long, in particular with large area sources and a large number of offsite receptors) or provide an output plot that is more consistent with actual worst-case impacts offsite, and also more consistent with a history of complaints. In a sense, these suggested enhancements offer a form of calibration of the model to actual conditions, which wastewater treatment facility owners and the general public may find more reasonable and useful.