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

                                                                           MWA Environmental




    3.3.3 ODOUR EMISSION RATES

    The Odour Emission Rate (OER) from a source is ultimately determined by the
    odour concentration of air being emitted and the volume of odorous air being
    emitted:

      OER (OU.m3/sec) = Odour Concentration (OU) x Ventilation Rate (m3/sec)


    The variation of the Ventilation Rate within poultry sheds is reasonably well
    defined and managed by computer control systems. The following key factors
    influence the variation of shed ventilation rate:

        •   Bird age / target temperature
        •   Number of birds
        •   Individual bird mass
        •   Ambient temperature and humidity

    The Odour Concentration within poultry sheds varies significantly depending
    upon shed design, ventilation system and farm management standards. The
    following key factors influence the odour concentration within poultry sheds:

        •   Litter moisture content and thus anaerobic biological activity, which is
            affected by:

                o   Frequency of litter replacement
                o   Water spillage from drinkers
                o   Effectiveness of drying by ventilation system
                o   Management (removal) of wet litter
                o   Litter depth

        •   Bird body and excrement odour (influenced by feed)


    Over many years, various odour estimation methods have been developed and
    applied for the purposes of representing emissions from poultry sheds.

    An odour estimation method which has been applied to the modelling of
    numerous poultry farm developments in South East Queensland in recent years
    is the ‘K Factor Method’ developed by Pacific Air & Environment6. This method
    estimates odour emission rates based upon the following relationship:




6 Ormerod, R. and G. Holmes (2005), Description of PAE Meat Chicken Farm Odour Emissions Model.



Ridgewood 12-002                              17                                   31 July 2014