Attachment 6 - Odour Impact Assessment - Katestone · 132005.638.06

4.2.2     Landfill

The modelled sources of odour produced by the landfill operations (and their odour emission rates) are detailed in
Table 2. The locations of the odour sources as modelled are presented in Figure 3. Four different spatial layouts
have been assessed to reflect the range of possible operations at landfill. Where cumulative results incorporating
the landfill emissions are presented, these are the maximum 99.5 th percentile of 1-hour average concentrations at
each receptor across any of the landfill layout scenarios after combination with the contribution of the proposed
composting operation.

The emission rates were sourced as follows:

    •     The active tip face is typically the most significant source of odour from a landfill receiving municipal solid
          waste (MSW). Active tip face odour emissions can be highly variable, therefore lower and upper bound
          emission rates have been identified to represent a realistic range of potential impacts.

              o    The lower bound odour emission rate of 1.27 ou/m2/s used for the active tip face was derived
                   from sampling at a landfill in QLD that receives primarily construction and demolition (C&D)
                   waste. It is relatively low for a landfill active tipping face, but likely representative of emissions
                   from the Noosa Resource Recovery Centre landfill active tip face much of the time.

              o    The upper bound odour emission rate of 7.06 ou/m2/s used for the active tip face was derived
                   from sampling at a landfill in Stapylton, QLD that receives a mix of wastes, including MSW. It is
                   a very high odour emission rate and emissions from the Noosa Resource Recovery Centre
                   landfill active tip face are likely to be much lower than this the majority of the time. Modelled
                   concentrations that assume this emission rate throughout the day are, therefore, likely to
                   represent over-estimates of the impact of the landfill.

              o    Noosa Council has estimated that, at night, the active tip face is covered with 70% consistency;
                   therefore, between 6pm – 6am, the active tip face has been modelled with an emission rate that
                   assumes 70% day cover and 30% uncovered active tip face emissions.

    •     The day cover odour emission rate of 0.35 ou/m2/s was derived from sampling at the same landfill in
          Stapylton as the upper bound active tipping face emission rate, and represents a high emission rate for
          covered material, compared to other literature values. It has been used across the upper and lower bound
          scenarios as a conservative emission rate for covered waste.

    •     The final cover emission rates of 0.03 ou/m2/s and 0.10 ou/m2/s were also derived from sampling at the
          same landfill in Stapylton, QLD. The lower bound emission rate is the maximum from sampling of final
          capped areas, while the upper bound emission rate is the average emission rate from interim capped
          areas, applied as a conservative representation of potential emissions bearing in mind that the application
          of final cover tends to occur in stages.

Table 2        Odour emission rates for landfill operations

                                                                 Odour emission rate (ou/m2/s)
        Odour-generating area
                                                     Lower bound                              Upper bound

             Active tip face                1.27 (day)           0.63 (night)          7.06 (day)          2.36 (night)
               Day cover                                                        0.35
              Final cover                                 0.03                                      0.10




 Katestone Environmental Australia Pty Ltd                                                           17 September 2026
 D25072-8 Noosa Council - Noosa Composting Odour Assessment - Final                                           Page 10