Acid Sulfate Management Plan · MCU16/0103

FPE Ref: 4956-161019-1.0


8.0 SUMMARY OF INVESTIGATIONS
8.1 GENERAL
The investigations were carried out in general accordance with the Guidelines for Sampling and Analysis of
Lowland Acid Sulfate Soils (ASS) in Queensland (QASSIT, 1998) and the report prepared in accordance
with SPP (DIIGLP 2016).

Depths of investigations were targeted to a maximum depth of 2.0m below existing surface levels at
representative locations in vicinity of the proposed works. It is understood that the development is likely to
involve the excavation of greater than 100m3 and the filling of greater than 500m2 on land below 5m AHD.

8.2 SUMMARY OF INVESTIGATIONS AND ANALYSIS RESULTS
Field tests were undertaken to determine the reactivity of soils and the presence of AASS and PASS. These
were undertaken at 0.25m intervals to borehole termination depth with a total of 16 samples collected. The
field test pHF resulted in no samples with pH values below 4.0 indicating possible absence of Actual Acid
Sulfate Soils (AASS). The field test pHfox resulted in numerous samples having a pH below the pHFOX 3
trigger value and generally indicate the presence of PASS from the two bore holes.

Of all the 16 samples tested within the scope of these works, 11 were found to trigger the decision making
criteria (i.e. <4 pHF and <3pHFOX) for the determination of AASS / PASS.

Interpretation of the field test results suggest that PASS or soil types which pose a risk of acid generation
are likely to be present on the proposed development site, but it was considered that further laboratory
analysis was required to confirm or deny the presence of PASS. A representative selection of samples were
sent for laboratory testing (SCR testing).

Laboratory analysis confirmed that the net acidity values for the three samples within BH1 and BH2
exceeded the relevant 0.03% net acidity action criteria.

An Acid Sulfate Soil Management Plan is required for the subject site as PASS material was identified
during investigation works. An Acid Sulfate Soil Management Plan is provided in the following sections.




October 2016                         Acid Sulfate Soil Investigation Report                                16
                                           New Duplex, Noosaville