Citation:
G.H. Drew, R. Smith, V. Gerard, C. Burge, M. Lowe, R. Kinnersley, R. Sneath and
P.J. Longhurst, Appropriateness of selecting different averaging times for
modelling chronic and acute exposure to environmental odours, Atmospheric
Environment, Volume 41, Issue 13, April 2007, Pages 2870-2880.
Abstract:
Odour emissions are episodic, characterised by periods of high emission rates,
interspersed with periods of low emissions. It is frequently the short term,
high concentration peaks that result in annoyance in the surrounding population.
Dispersion modelling is accepted as a useful tool for odour impact assessment,
and two approaches can be adopted. The first approach of modelling the hourly
average concentration can underestimate total odour concentration peaks,
resulting in annoyance and complaints. The second modelling approach involves
the use of short averaging times. This study assesses the appropriateness of
using different averaging times to model the dispersion of odour from a landfill
site. We also examine perception of odour in the community in conjunction with
the modelled odour dispersal, by using community monitors to record incidents of
odour. The results show that with the shorter averaging times, the modelled
pattern of dispersal reflects the pattern of observed odour incidents recorded
in the community monitoring database, with the modelled odour dispersing further
in a north easterly direction. Therefore, the current regulatory method of
dispersion modelling, using hourly averaging times, is less successful at
capturing peak concentrations, and does not capture the pattern of odour
emission as indicated by the community monitoring database. The use of short
averaging times is therefore of greater value in predicting the likely nuisance
impact of an odour source and in framing appropriate regulatory controls.
