Acid Sulfate Management Plan · MCU16/0103

FPE Ref: 4956-161019-1.0


           equivalent). For highly permeable soils, the option of placement of an impervious layer should be
           adopted;
          All soils below existing surface (pre filling levels) levels to be excavated within the site shall be
           subject to treatment and validation testing;
          All ASS material requiring treatment must only be treated in treatment areas;
          All excavation and treatment areas shall be isolated from major external catchments by perimeter
           drains and/or bunds covered with an impervious layer and a layer of fine Aglime to neutralise any
           leachate;
          Erosion and sediment protection measures must be installed in accordance with best practice (i.e.
           International Erosion Control Association or IECA) which will adequately contain runoff from all
           areas of land used for treatment of ASS;
          Soils shall be stockpiled for no more than 48 hours prior to neutralisation wherever possible;
          Soil must be sufficiently dry before liming is commenced so that the Aglime can be thoroughly
           mixed through the soil. Soil should be dried by spreading and leaving open to the atmosphere.
           Drying can be accelerated by regular aeration through turning with an excavator or backhoe.
           Drying should be carried out on a treatment pad within the bunded area protected from stormwater
           ingress;
          Treatment rates should be applied at 28.7mg/kg of Aglime and confirmed through validation
           testing;
          Mixing of ASS material with Aglime shall be carried out by spreading the soil in layers of not more
           than 300mm thick using an agricultural spreader and disc plough, rotary hoe or similar. Care shall
           be taken to ensure that mixing occurs throughout the depth of the layer prior to placement of new
           material;
          Following the successful treatment of the soil (as determined through the validation testing),
           material can potentially be reused onsite;
          Equipment used in the treatment of ASS shall be washed to prevent corrosion and transport of
           ASS material off the dedicated treatment area; and
          A treatment basin, of a size not less than that capable of accommodating a 24 hour storm event
           with an ARI of 1 in 5 years plus sediment storage volume, shall be constructed to capture any acid
           leachate and runoff from treatment areas prior to discharge.


9.4.3 Neutralising Materials
      A sufficient supply of Aglime shall be kept onsite at all times for the treatment of ASS. The Aglime
        should be fine ground (< 1mm) calcium carbonate (CaCO3);
      Dolomitic Aglime, or magnesium-blend Aglime, materials impose environmental risks from
        overdosing with the potential to damage estuarine ecosystems and should be avoided;
      The supply of Aglime shall be stored in a covered and bunded area to prevent accidental release to
        waters and/or deterioration of neutralising capacity;
      A reasonable quantity of calcium hydroxide solution (hydrated lime) shall be kept onsite at all times
        for treatment of acidic waters contained by the treatment basin/s; and




October 2016                           Acid Sulfate Soil Investigation Report                                20
                                             New Duplex, Noosaville