Odour impact assessment by means of dynamic olfactometry, dispersion modelling and social participation

This work discusses how it is possible to assess odour impact in presence of multiple similar sources by illustrating a case study. The study was conducted on an area of northern Italy comprising three small municipalities where four rendering plants are located near to each other. Based on the emission data resulting from olfactometric surveys conducted in different periods of the year the overall odour emission rate emitted by each plant were evaluated, showing that the major contributor to the odour impact on the territory was plant 2. These data were linked with meteorological and orographical data in order to evaluate odour dispersion with a model (Calpuff). The results of the odour dispersion modelling confirmed the outcomes of the olfactometric survey and they were further validated through a “questioning” survey, conducted with the aim of involving the population by means of questionnaires for reporting the perceived odour episodes, which showed a good correspondence (86.5%) between odour perceptions and simulated odour immissions.