Acid Sulfate Management Plan · MCU16/0103

FPE Ref: 4956-161019-1.0


9.0 ASS MANAGEMENT PLAN
An ASS Management Plan (ASSMP) is required in accordance with the SPP (DILGP 2016) Guideline due to
the presence of ASS and likelihood of disturbance during construction.

Excavating soils which may be ASS, or filling that results in actual ASS being moved below the water table
or previously saturated ASS being aerated, can result in the following environmental and associated impacts
where these soils are not managed appropriately;
      Oxidisation of ASS in excavated or aerated sediments, resulting in acid production and potential
         release of heavy metals;
      Cosmetic and structural damage to concrete and other infrastructure;
      Uncontrolled run-off of acidic waters, heavy metals, and acid leaching to adjacent sensitive
         environments and groundwater resources; and
      Disease and mortality of flora and fauna species as a result of altered environmental conditions.

Based on the filling proposed and site investigations undertaken, proposed filling is unlikely to result in
lowering of groundwater levels recorded onsite and aeration of previously saturated ASS, nor result in ASS
being moved below the water table.

9.1 OBJECTIVES
The objectives of ASS treatment and management are to ensure that:
     There is adequate treatment of ASS through validation monitoring, such that soils have sufficient
        acidic naturalising capacity (ANC) measured through appropriate field soil testing and laboratory
        verification;
     Runoff from stockpiled soil and treatment areas is collected, tested and treated (if requiring
        treatment) prior to discharge to ensure compliance with Water Quality Objectives (WQO’s)
        applicable to the site;
     Groundwater quality of aquifers potentially affected by disturbance and treatment of ASS are
        monitored to check mitigation measures are effective in minimising likelihood of environmental
        harm; and
     Stormwater run-off from areas in which treated ASS soils are placed are monitored for appropriate
        quality indicators to check treatment has been effective in minimising likelihood of environmental
        harm.

9.2 RELEVANT LEGISLATIVE AND GUIDELINE DOCUMENTATION
This ASSMP has been completed with reference to and in general accordance with the following
documentation;
     Environmental Protection Act 1994;
     Environmental Protection Regulation 2008;
     Queensland Acid Sulfate Soil Technical Manual — Soil Management Guidelines, Version 3.8
       (Queensland Government, November 2002);
     Guidelines for Sampling and Analysis of Lowland Acid Sulfate Soils in Queensland (CR Ahern, MR
       Ahern and B Powel, October 1998).




October 2016                        Acid Sulfate Soil Investigation Report                              17
                                          New Duplex, Noosaville