Attachment 6 - Odour Impact Assessment - Katestone · 132005.638.06

6. EMISSIONS TO THE ATMOSPHERE

Modelled source areas, odour emission rates, and total odour emissions for the proposed composting operations
are presented in Table 4. Further details of the source configuration in the dispersion modelling assessment are
provided in Section A2 of Appendix A. The layout of modelled sources is shown in Figure 2.

For the composting facility, the modelled areas were determined based on the provided site layout, while also being
informed by the precise design areas; the drawn areas are all marginally greater than the design areas, which is
conservative. Noosa Council provided the following design areas for individual sources:

    •     Commercial drop / green waste stockpile – 285 m2

    •     Public drop – 394 m2

    •     Maximum area occupied by freshly mixed compost - 140 m2

    •     Biofilter – 200 m2

    •     Maturation bays – 1,128 m2

Table 4         Composting operations odour emission rate summary
                                 Modelled source area            Emission rate                Emission rate
            Source
                                         (m2)                      (ou/m2/s)                     (ou/s)
        Commercial drop                  287.0                         2.4                         688.7
          Public drop                    384.3                         2.4                         922.3
            Bunker                       109.4                         4.0                         437.6
  Freshly mixed compost                  140.1                         4.0                         560.3
            Biofilter                    212.6                         1.9                         393.3
        Maturation bays                 1,551.4                        0.7                        1,042.5
                   Total odour emissions                                -                         4,044.7

Modelled source areas, odour emission rates, and total odour emissions for the landfill operations are presented
in Table 5 for the lower bound emissions scenario and in Table 6 for the upper bound emissions scenario. The
areas and emission rates presented are for the layout whereby the active tip face is located to the southwest of the
landfill (bottom left in Figure 3), but care has been taken to ensure that differences in source areas and total
emissions rates between the four scenarios are minimal. Further details of the source configuration in the dispersion
modelling assessment are provided in Section A2 of Appendix A.

For the landfill, modelled source areas were determined based on specific information provided by Noosa Council
alongside staged filling plans. The following key inputs were considered:

    •     Noosa Council advised that the active tip face area can range from 900-1,500 m2. The maximum stated
          area has been used, which is conservative.

    •     Noosa Council advised that the area covered with day cover only typically averages 12,000 m 2.

    •     It was assumed that the remainder of the landfill area had final cover applied – Noosa Council has advised
          that gas extraction covers the entire landfill, therefore this is a reasonable assumption, and the upper
          bound emission rate may over-state odour emissions from the covered areas of the landfill.




 Katestone Environmental Australia Pty Ltd                                                      17 September 2026
 D25072-8 Noosa Council - Noosa Composting Odour Assessment - Final                                      Page 16