Dewatering Management Plan · OPW24/0032

                                                                                           ADG Consulting Pty Ltd


          Weekly monitoring of field parameters (pH, electrical conductivity, dissolved oxygen, temperature
           and turbidity) in the untreated extracted groundwater, treated discharge water, receiving waters
           and background waters by ADG Consulting.
          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_Rev0_08.10.21                                                        Page 14