Odour - impact assessment around a landfill site from 1 weather - type classification , complaint inventory and 2 numerical simulation

8 Gases released from landfill sites into the atmosphere have the potential to cause olfactory nuisances within the surrounding com9 munities. Landfill sites are often located over complex topography for convenience mainly related to waste disposal and environmental 10 masking. Dispersion of odours is strongly conditioned by local atmospheric dynamics. Assessment of odour impacts needs to take 11 into account the variability of local atmospheric dynamics. In this study, we discuss a method to assess odour impacts around a landfill 12 site located over complex terrain in order to provide information to be used subsequently to identify management strategies to reduce 13 olfactory nuisances in the residential neighbourhoods. A weather-type classification is defined in order to identify meteorological 14 conditions under which olfactory nuisances are to be expected. A non-steady state Gaussian model and a full-physics meteorological 15 model are used to predict olfactory nuisances for both the winter and summer scenarios that lead to the majority of complaints in 16 neighbourhoods surrounding the landfill site. Simulating representative scenarios rather than full years make a high resolution sim17 ulation of local atmospheric dynamics in space and time possible. Results underline the key role of local atmospheric dynamics in 18 driving the dispersion of odours. The odour concentration simulated by the full-physics meteorological model is combined with the 19 density of the population in order to calculate an average population exposure for the two scenarios. Results of this study are expected 20 to provide helpful information to develop technical solutions for an effective management of landfill operations, which would reduce 21 odour impacts within the surrounding communities. 22