ADG1304.21 Dewatering Management Plan_Rev1.1_17.12.24

                                                                                            ADG Consulting Pty Ltd


           Weekly laboratory analysis of treated discharge water and receiving waters for suspended solids
            and dissolved 0.45µm filterable metals (aluminium, arsenic, cadmium, chromium, copper, iron, lead,
            nickel, zinc and mercury). Total aluminium and iron will also be analysed for, if required.
           Pre‐discharge/initial monitoring of field parameters (pH, electrical conductivity, dissolved oxygen
            and oxidation‐reduction potential) in the extracted groundwater (prior to treatment) to assess
            changes in groundwater chemistry associated with PASS oxidation.
           Pre‐discharge/initial laboratory analysis of extracted groundwater (prior to treatment) for
            suspended solids, dissolved 0.45µm filterable metals (aluminium, arsenic, cadmium, chromium,
            copper, iron, lead, nickel, zinc and mercury) and for soluble sulfate and chloride to assess changes
            in groundwater chemistry associated with PASS oxidation. Total aluminium and iron will also be
            analysed for, if required.
           Laboratory analysis of untreated groundwater would also be performed periodically (monthly) if
            changes in untreated groundwater pH levels are detected that may indicate local acidification, and
            to determine any changes in local groundwaters that may require further investigation of potential
            environmental impacts.
      All samples will be recovered by a suitably qualified Environmental Scientist and submitted to a National
      Association of Testing Authorities (NATA) accredited laboratory for analysis.
6.5.3 Monitoring responsibilities
      The persons responsible for undertaking the compliance monitoring described in Section 6.5.2 above are
      shown in Table 5.

      Table 5 Monitoring responsibilities

                            Activity                          Frequency          Responsibility        Person

        Monitoring of field parameters in discharge water
                                                                  Daily           Site Manager      Site Manager
        and untreated extracted groundwater

        Monitoring of field parameters in untreated
                                                                                                   Environmental
        extracted groundwater, discharge water,                 Weekly           ADG Consulting
                                                                                                     Consultant
        receiving waters and background waters

        Laboratory analysis of samples recovered from                                              Environmental
                                                                Weekly           ADG Consulting
        discharge water and receiving waters                                                         Consultant

        Monitoring of field parameters in extracted                                                Environmental
                                                                Weekly           ADG Consulting
        groundwater (pre‐treated)                                                                    Consultant

        Laboratory analysis of samples recovered from       Initially, then as                     Environmental
                                                                                 ADG Consulting
        extracted groundwater (pre‐treated)                     required                             Consultant

6.6   Maintenance
      The groundwater treatment systems must be regularly maintained. Maintenance must include:
           Regular cleaning and or replacement of the filters within the filtration unit, where required to be
            installed.
           Regular removal of sediment from the sedimentation tank. The sediment must be either returned
            to the excavation pit for dewatering and bulking out with excavated material, or removed from the
            site by a licensed liquid waste contractor.
           Regular check of the dosing system and top‐up of buffering solutions and flocculants.




 ADG1304.21 Dewatering Management Plan_Rev1.1_17.12.24                                                      Page 14