Noise and Air Quality Impact Assessment W D Milligan 31 July 2014

                                                                 MWA Environmental




3.0 ODOUR IMPACT ASSESSMENT
3.1 ODOUR ASSESSMENT METHODOLOGY

Detailed odour dispersion modelling has been conducted using the CALMET /
CALPUFF modelling system to assess the exposure of surrounding sensitive
receptors to odour emissions from the proposed poultry sheds. The modelling has
been updated from the November 2012 report in accordance with requests made by
Council through the peer review process in 2013. The odour emission rate models
and dispersion modelling methods are generally in accordance with the Best Practice
Guidance for the Poultry Industry – Plume Dispersion Modelling and Meteorological
Processing (PAE Holmes for DEEDI, May 2011).

The CALMET / CALPUFF modelling system considers 3-dimensional unsteady state
meteorology and is appropriate for modelling pollutant transport on a regional scale
and for complex terrain and coastal zones. The CALMET / CALPUFF modelling
system simulates the effects of spatially and time varying meteorology on pollutant
transport within the model domain, including chemical transformation and removal.
CALPUFF considers emissions as a series of puffs that if emitted at a sufficient
frequency simulate a continuous emission. This representation of the plume as a
series of puffs allows the pollutant transport to vary spatially across the model
domain in accordance with the 3-dimensional meteorological field.

A site-specific 3-dimensional prognostic meteorological dataset generated by TAPM
was processed using the CALMET program to provide meteorological inputs in a
form suitable for the CALPUFF dispersion model. The terrain and land use
resolution was refined to a 100 metre grid for the CALMET / CALPUFF modelling to
ensure a suitable representation of the terrain at the locality. CALMET prepares 3-
dimensional meteorological data for each hour of the CALPUFF run based upon the
prognostic meteorological data produced using TAPM.

The CALMET model was set up within a 10 km x 10 km area surrounding the subject
site with the CALPUFF model configured to model dispersion within a 5 km x 5 km
area surrounding the subject site. The topography of the subject site and
surrounding area was sourced from NASA Shuttle Radar Topography Mission
(SRTM3) digital elevation data at a resolution of 100 metres. A receptor grid of 100
metre resolution was modelled over the domain.



3.2 RELEVANT ODOUR AMENITY GUIDELINE

For the assessment of complex mixtures of odorants, the Queensland Ecoaccess
Guideline: Odour Impact Assessment from Developments recommends a 2.5 Odour
Units 99.5th percentile 1 hour average odour criterion as being appropriate for the
assessment of the odour amenity of a residential land use.




Ridgewood 12-002                        14                              31 July 2014