ADG1304.21 Dewatering Management Plan_Rev1.1_17.12.24

                                                                                                          ADG Consulting Pty Ltd


      Regardless of the WQOs adopted in this DMP, the General Environmental Duty set out in the EP Act is
      paramount, which requires that “a person must not carry out an activity that causes or is likely to cause
      environmental harm unless the person takes all reasonable and practicable measures to prevent or
      minimise the harm”.
4.3   Proposed water quality objectives
      The proposed water quality objectives that have been developed for the discharge of extracted
      groundwater from the site are provided in the Tables below. All water discharged from the site must
      comply with the discharge criteria provided in Table 2. In addition, the receiving water quality within a
      20 m radius of the discharge point entry to the receiving water shall comply with the receiving water
      criteria provided in Table 3. Receiving waters data will be assessed against background monitoring data
      if non‐compliant results are obtained at the receiving waters monitoring location.

      Table 2 Discharge criteria

                               Parameter                                                        Criteria

        Physico‐chemical
        pH (pH units)                                                                          6.5 – 8.51
        Dissolved oxygen (% saturation)                                                           ≥802
        Suspended solids (mg/L)                                                                  ≤501,2
        Turbidity (NTU)                                                                           ≤502
        Litter                                                                               None visible
      Table notes:
      1. QWQG 2009 (2013) Refer to Table 8.2.1. Summary of design objectives for management of stormwater quality and flow –
         construction phase of development in Queensland.
      2. Typical discharge criteria recognised throughout Queensland & NSW.

      Table 3 Receiving waters criteria

                               Parameter                                                        Criteria

        Physico‐chemical
        pH (pH units)                                                                          7.8 – 8.31
        Dissolved oxygen (% saturation)                                                        85 – 1051
        Suspended solids (mg/L)                                                                   ≤141
        Turbidity (NTU)                                                                            ≤61
        Dissolved metals (µg/L)
        Aluminium                                                                   No relevant ANZG criteria available

        Arsenic                                                                                   2.32*
        Cadmium                                                                                   5.52
        Chromium                                                                                  4.42
        Copper                                                                                    1.32
        Iron                                                                        No relevant ANZG criteria available

        Lead                                                                                      4.42
        Nickel                                                                                     702
        Zinc                                                                                        82
        Mercury                                                                                   0.42
        Totals metals (µg/L)
        Aluminium                                                                        No ANZG criteria / 2003

        Iron                                                                             No ANZG criteria / 3003




 ADG1304.21 Dewatering Management Plan_Rev1.1_17.12.24                                                                     Page 7