Acid Sulfate Soils Management Plan · OPW19/0205

PROCEDURE A
Management of Acid Sulfate Soils


A1.     GENERAL
The procedures outlined below are provided for the management of the excavation, stockpiling,
handling and transport of acid sulfate soils (ASS). It is proposed to either treat ASS materials in-situ
during excavation or transport to an onsite ASS treatment area as soon as practicable. The Site
Supervisor or their delegated representative will be responsible for the excavation, stockpiling,
handling and transport of excavated ASS materials. The Site Supervisor or their delegated
representative will also be responsible for the supervision of in-situ treatment, and management of
the treatment area, and for ensuring that the excavated ASS is remediated and verified in accordance
with the ASS MP and associated procedures.

A2.       OBJECTIVES
1)    Appropriately manage the stockpiling, handling and transport of confirmed and suspected ASS
      materials

2)    Comply with conditions of licences, permits or other approvals issued for the project.

A3.       STATUTORY REQUIREMENTS AND GUIDELINES
1)    Queensland Acid Sulfate Soil Technical Manual: Soil Management Guidelines V4.0, 2014. Dear, S-
      E., Ahern, C. R., O'Brien, L. E., Dobos, S. K., McElnea, A. E., Moore, N. G. & Watling, K. M.
      Department of Science, Information Technology, Innovation and the Arts, Queensland
      Government

2)    Ahern, CR., Ahern, M.R. and Powell, Guidelines for Sampling and Analysis of Lowland Acid Sulfate
      Soils in Queensland, 1998

3)    State Planning Policy – state interest guideline, Water quality, August 2014

4)    Environmental Protection Act 1994
5)    Environmental Protection Policy (Water) 2009

A4.       MANAGEMENT MEASURES
A4 (A).          MANAGEMENT OF EXCAVATIONS
An earthworks strategy shall be developed to plan and track movement, treatment and verification of
ASS materials.
Should groundwater inflow be considered excessive during basement excavations, alternative
construction methodologies will be considered to mitigate the possible impacts of lowered
groundwater levels and the potential oxidation of surrounding sediments.
All waters collected from groundwater and surface water inflow into excavations via seepage and
runoff must be retained, monitored and appropriately treated to comply with the appropriate discharge
criteria (Procedure C) prior to discharge off site or re-use on site.

A4 (B).          STOCKPILING, HANDLING AND TRANSPORT OF ASS
Wherever practical the earthworks handling should involve transport directly from cut to treatment
areas and stockpiling of untreated soils with existing or potential acidity should be avoided. The
recommended maximum time period for which soils can be temporarily stockpiled without treatment
is 18 hours (overnight) for coarse sandy material and 3 days, (e.g. a weekend, 66 hours) for fine textured
silty clay material. The option of in-situ treatment may also be considered. However, treated soil will
still need to be stockpiled in an appropriate area for verification testing prior to removal off-site.

All confirmed ASS materials encountered during excavations will be transported to the designated ASS
treatment area or treated in-situ and stockpiled for verification sampling. Accurate details of material



April 2019
J000799-003-R-Rev0 – Procedure A                   1/2