Construction Mangement Plan Reference Document OPW19-0239 · OPW19/0239

                                                                                    mcnab construction
                                                                                     07-DOC-003 Rev 4
The presence of Acid Sulphate Soils in indicated by:

      •      Presence of Jarosite in soil (mottled yellow colour)
      •      Presence of rust-coloured iron-staining on soils and infrastructure and in water
      •      Presence of rotten egg smell (hydrogen sulphide) on disturbance to soils
      •      A soil PH of soil less than four or
      •      Presence of dark grey muds to grey sands or peats.

If Acid sulphate soils are indicated cease work immediately and contact the Project Manager.

7.5              Dispersive soils
Typically clays and fine silts

Dispersive soils are recognisable by:

      •      Opaque cloud appears when the soil aggregates break down in water or
      •      Base sandy patches in exposed areas

Visual monitoring should be undertaken regularly to look for any indication that dispersive soils are
present.

If dispersive soils are indicated, minimise disturbance and place emphasis on erosion and drainage
controls. Suspended fine clays are difficult and expensive to trap once mobilised. In some instances,
chemical treatment may be necessary to settle particles.

Erosion control matting is useful for preventing erosion. Sediment weirs with geo-fabric lining
upstream may assist with sediment control. For disturbance great than 1ha, a Type D sediment
basin is required.

7.6              Highly Erodible soils
The soils in the area of the work site are considered to have a potential for erosion. Due to the
variability of soils it is possible that highly erodible soils will be encountered.

The presence of highly erodible soils is indicated by:

      •      Rills or gullies and/or sedimentation down stream
      •      Non-cohesive soils, such as silt, fine sands and low to medium plastic clays.

If highly erodible soils are indicated, emphasis should be placed on the retention of vegetative cover
and prevention of erosion in the first instance. Although sediment control devices are useful in the
capture of lost sediments, they are not as effective in protecting the receiving environment as
maintaining high standards of erosion control. If the soils are dispersive, see notes above.

7.7              Vegetation disturbance
In the case of disturbance to vegetation within the road reserves or vegetation within a waterway,
the appropriate Local Government entity should be notified.




Infinity Apartments – Gympie Tce Noosaville Environmental Management
Plan                                                                                         Page 21 of 39