Appendix H Geotechnical Investigation - 14-16 Mary Street, Noosaville - Bounce Hostels 15.6.2018

J000605-001-R-Rev1                                                                                      March 2018


B1.0 ACID SULFATE SOILS INVESTIGATION METHOD AND RESULTS
B1.1 Investigation aims
The aims of this investigation were to:

   Conduct an ASS assessment in general accordance with SPP14 and the Queensland Sampling
    Guidelines
   Quantitatively identify the presence or absence of ASS across the site
   If necessary, assess the likely impact of the proposed development on ASS
   If necessary, provide prudent management measures so that the release of acid leachate from
    disturbed soil and groundwater does not have significant adverse effects on the natural and built
    environment or human health.

B1.2 Laboratory testing
A groundwater sample was collected from BH2 on 28 February 2018 to provide a ‘snapshot’ of the
groundwater conditions (groundwater suite laboratory testing).
A total of 64 soil samples were screened at our laboratory to assess field pH (pHF) and pH after oxidation
(pHFOX) using 30% hydrogen solution.
Based on the results of pH screening tests, 16 samples were selected to undergo quantitative analysis by
the Chromium Reducible Sulfur (Scr) suite in accordance with ASS Method 23F and 22B laboratory
procedures of Ahern et al (2004).
An overall acid-base accounting method was used to calculate a ‘net acidity’ value which is used to qualify
analytical test results and calculate liming rates. This equation is:

 Net Acidity = Actual Acidity (as TAA) + Retained Acidity (as SNAS) + Potential Acidity (as SCR) - insitu Acid
              Neutralising Capacity (ANC).

The laboratory certificates of analysis, chain of custody documents and laboratory quality control documents
are attached, and the results are summarised in Table B1. Observations and discussion on the laboratory
findings are provided below.

B1.3 Preliminary Screening
Results of preliminary screening are summarised in Table B1. Soil pH (represented by pHF results) was
found to range between pH 4.9 and pH 7.4 (acidic to neutral), with the majority of the samples being above
pH 6, indicating a low to medium probability of the presence of actual ASS at borehole locations. There was
generally a noted difference in the pHFOX and pHF test results for the majority of samples tested from the
boreholes. All samples displayed a mixture of extreme to low level reactions to the addition of hydrogen
peroxide. The pHFOX ranged from pH 1.2 to pH 6, and more than half of the samples observed were below
pH 3, suggesting a high potential for the presence of PASS.

B1.4 Quantitative Soils Analysis
Table B1.4 below shows the ASS action levels adopted in Queensland. These categories are used to identify
whether action / management of ASS spoil is required, based on ‘net acidity’. For major fill works and
disturbances of more than 1,000 tonnes, an action criterion of 0.03% S equivalents (18 moles/tonne) is
adopted for all soil types; and was adopted for this investigation.