Appendix 6. Odour Buffer Assessment [As Published] · 132007.2399

                                                                                                [8]
              Odour Buffer Assessment
              StarCo Developments


3.3.3       Alternative Assessment Tools for Odour Assessment – Expansion of Existing
        Activities

Alternatively, EPA will accept an assessment of odour impacts using the tools discussed in
Appendix A of the Guideline document. These tools are:

        Community odour surveys;

        Odour diaries;

        Odour complaints;

        Field observations of odour intensity, character and offensiveness; and

        Compliance history.

The guideline states

        These tools can be used for assessing the current status of odour impacts from
        existing industries that may wish to expand. Impact from an existing facility can be
        more realistically assessed using these tools in preference to relying solely on
        dispersion modelling. Once the survey is conducted to establish the current odour
        status of an existing facility, a site-specific odour assessment criterion can be
        developed for the expansion of this facility. Odour dispersion modelling should not
        be used to try to prove the absence of an adverse effect from an existing facility
        when community data, such as complaint records, are already available to
        demonstrate the current level of effect.

Some of these methods, for example, community odour surveys, have been incorporated into this
study for Noosa Springs



3.4 Summary of Criteria Based on EPA Guideline

In this case for defining a suitable buffer around the Noosa STP, a default odour criterion based on
the Guideline would be C99.5 1hr = 2.5 ou (see section 3.3.1). However, the results of the small
community survey and the complaints record collected by both Noosa Springs and the Noosa STP
must also be taken into consideration.

Actual experience of a community with a specific odour source is potentially far more meaningful
than default assessment criteria that do not take into account site specific factors or the important
influence of the modelling inputs and methods on predicted odour levels.




4   MODELLING METHODOLOGY

This section explains the approach taken to predict odour levels associated with the proposed
development. The prediction relies on odour dispersion modelling using the CALPUFF dispersion
model. As with any model CALPUFF requires inputs in three major areas:

        Emission rates and source details,

        Meteorology, and

        Terrain and surface details, as well as specification of specific receptor locations.



1898a report final.doc                                                       PAE Job Number 1898a