6. Noosa River DMP Ver0 (Combined)

Figure 7. Sub-bottom profiling Noosa River, Hilton Esplanade (Acoustic Imaging, 2020)



                  Geotechnical Investigations
Soil Surveys 2006
Acid sulfate testing was undertaken in November 2006 by Soil Surveys Engineering P/L as part of the original
Noosaville Dredge Management Plan (2006), with results indicating that:
          “there is ample self buffering capacity present in the soils to effectively neutralise any acid that could potentially
          be produced. Therefore we recommend that no lime treatment would be required on the samples tested during
          this investigation”

BMT 2022
The BMT Sediment Sampling Report, shows that the sand samples were dominated by sand fractions (0.06-2
mm), with a combined average of approximately 93%. There were minor (typically <10%) components of clay (<2
μm), silt (2-60 μm) and gravel (0.2-6 cm) fractions (0.06-2 mm) in samples. There were no cobbles (>6cm) or in
any of the site horizons.
Updated sediment sampling was undertaken by BMT in 2022; however, results were not consistent with the
previous Soil Surveys investigation, showing potential acid sulfates, generally at extremely low levels with one
high spot identified at BH08.
BMT 2022 assessed all samples in accordance with NAGD 2009, providing the following summary:
          “Overall, the sediments were relatively clean with no analytes exceeding the relevant NAGD screening levels or
          NEPM investigation levels, thus would be suitable for offshore or land-based disposal, with suitable PASS
          material management.”



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