Compiled Reference Document - MCU25/0020 (As Published)

8.1          Training and Orientation
Appropriate training should be provided to all Contractor staff involved in earthworks on the site, to be
delivered as part of site induction. Sessions should be conducted prior to the commencement of
earthworks and at other such regular intervals as required to ensure staff are fully aware of the
requirement for field management of ASS and associated waters, the management strategies to be
implemented, and their roles and responsibilities in achieving the desired management outcomes.

8.2          Management of Disturbed Material
The soils where excavated or otherwise disturbed as part of development works must be treated to
neutralise the net acidity present. Excavated soil shall be mixed with a neutralising agent (fine
agricultural lime) as follows:
   Fill and natural sand encountered to 4 m BGL – no treatment required.
   Materials excavated 4 m BGL and 8 m BGL – rate to be determined by characterisation testing.
Due to the spatial limitations, excavated soil from 4 m to 8 m BGL would need to be transferred to a
designated storage stockpile offsite while laboratory characterisation testing is completed.
Characterisation testing shall be undertaken at a rate of 1 test per 200 m3 of soil excavated from 4 m to
8 m BGL. Each characterisation sample will be taken by compositing excavated material from no less
than six subsample locations (including at depth) from the stockpile. The laboratory test regime for
characterisation testing will involve the CRS suite.
All materials (including volumes of soil and storage locations) must be recorded and tracked by the
Contractor. Material must be stored in a fashion that will allow treatment, if necessary, together with
suitable drainage management at the storage site to ensure that any surface water runoff and leachate is
able to be captured and effectively treated to ensure that no waters are released without meeting the
required site release criteria described in Table 7.
Following excavation of the basement, a lime guard layer will be applied to the subgrade soil at rate of
5 kg lime per m2, prior to construction of the blinding slab, or basement floor. A guard layer must also
be applied at a rate of 5 kg lime per m2 across the offsite stockpile subgrade.
Recommended liming rates assume the use of fine-grained agricultural lime with a purity of not less than
90%, a soil bulk density of 1.7 tonnes per cubic metre, and a factor of safety of 1.5 to allow for
incomplete mixing and the reactivity of the lime.

8.2.1        Verification Testing
To verify treatment of excavated ASS material from 4 m to 8 m BGL, verification testing will be carried out
at a rate of 1 test per 500 m3 of treated soil.
Each verification sample will be taken by compositing treated material from no less than six subsample
locations (including at depth) from treated soil within the treatment area. The laboratory test regime for
validation testing will involve the measurement of pH, net acidity (the sum of actual, potential and
residual acidity) and acid neutralising capacity (ANC). Where the pH post treatment is greater than 6.5
and the ANC is not less than 1.5 times the net acidity, then the validation shall be deemed successful.
If analysis of any verification sample/s indicates unsuccessful treatment, re-treatment of the represented
soil will be required prior to completion of another series of verification testing. This procedure should
be repeated until successful treatment has been verified.


Geo-environmental Investigation Proposed Residence
4 June 2025 | 25040-001-Rev1                                                                               22