Acid sulfate Management Plan Reference Document OPW19-0239 · OPW19/0239

Gympie Terrace Noosaville Pty Ltd



4.0      SITE DESCRIPTION
The site is located at 217 to 219 Gympie Terrace, Noosaville; covering a total area of approximately
0.11 hectares.
The site was generally flat and clear at the time of our investigation, comprising short grass and a few small
to medium sized trees located in the south east corner.
Site conditions at the time of our investigation are shown in Photograph 1.




Photograph 1: Site conditions at the time of fieldwork, looking south west from borehole BH1.

5.0      OVERVIEW OF ENVIRONMENTAL ISSUES
This section provides a brief overview of environmental issues related to ASS associated with the excavation
stage of the proposed development.

  5.1 ASS Summary
The results from this investigation indicate that low levels of existing acidity and potential ASS (PASS) are
distributed throughout the natural sands across the site.
The SPP14 Guidelines require that the level of treatment for management of ASS is based on treatment of
all existing and potential acidity. The results of the laboratory testing have been accumulated in an Acid-
Base Account to give the Net Acidity for each sample in units of mol H+/tonne as presented in Table C1 of
our geotechnical report (ref. J000799-002-Rev0). This value has been calculated from sulfur trail potential
acidity (SCr) plus actual acidity (TAA).
Liming rates have been calculated in kg CaCO3/m³ using a factor of safety (fineness factor) of 1.5 and an
assumed bulk density of 1.8 tonne/m3. Calculation of liming rates required for full neutralisation of combined
existing and potential acidity are presented in Table 1.
Table 1: Liming Rates
 Material Type                          Depth                         Treatment Rate

                                        0 m – 1 m BGL                 5 kg CaCO3/m³
 Natural Sands
                                        Below 1 m BGL                 15 kg CaCO3/m³
Note:    * Below Ground Level
         ** Liming rate based on maximum values.




J000799-003-R-Rev0                                                                                  Page 2