Characterization of Year-to-Year Variability of Separation Distances Between Odour Sources and Residential Areas to Avoid Annoyance

Abstract

Direction-dependent separation distances between sources of malodorous gases and residential areas play a valuable role to avoid annoyance and complaints. Atmospheric dispersion modelling is routinely used to calculate these distances, with meteorological data regarded as one of the critical inputs for the models. This study explores the temporal representativeness of using one year of meteorological data as model input to calculate reliable separation distances. The year-to-year variability of direction-dependent separation distances in the vicinity of an odour source was assessed using a sample of six years of hourly meteorological observations. The calculations relate to the odour impact criterion prescribed by the jurisdiction of Queensland (Australia). The results show that the coefficient of variation, used as a statistical measure to characterize the year-to-year variability, has a mean value of 12%. Fair agreements are thus observed for the separation distances from one year to the other at the site under investigation, which supports the utilization of one year of meteorological data as a good compromise to achieve reliable accuracy. The findings of this study have the potential to support more cost-effective odour dispersion modelling guidelines.