Reference Document - Dewatering Management Plan (For Stamping) MCU25/0053 & OPW25/0074

                                                                                                                ADG Consulting Pty Ltd

                              extracted groundwater, treated discharge water and off‐site monitoring in the receiving waters (in the
                              mixing zone within a 20 m radius of the discharge point). The exact location within the receiving waterway
                              (Noosa River) is to be confirmed. Background water quality monitoring of field parameters will also be
                              conducted during each sampling event, if applicable. Background samples will be recovered from the
                              Noosa River, either upstream or downstream from the receiving water location (tide dependant)
                              approximately 300 m upstream of the discharge point).

                              The proposed monitoring locations are shown in Figure 1, Appendix A and are subject to confirmation
                              following mobilisation of dewatering equipment to site.

                              Monitoring will be undertaken at the following frequencies:
                                 Daily monitoring of field parameters (pH, and turbidity) in the treated discharge water. Daily
                                  monitoring will be undertaken by a suitably trained site employee under the supervision of the Site
                                  Manager.

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

                                  Weekly laboratory analysis of treated discharge water and receiving waters for suspended solids,
                                   dissolved 0.45µm filterable metals (aluminium, arsenic, cadmium, chromium, copper, iron, lead,
                                   nickel, zinc and mercury) and total metals (aluminium & iron) by ADG Consulting.

                                  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 (sampled by ADG Consulting).

                                  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), total metals (aluminium and iron) and for soluble
                                   sulfate and chloride to assess changes in groundwater chemistry associated with potential acid
                                   sulfate soil (PASS) oxidation (sampled by Environmental Consultant).

                                  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.




                        ADG1777.25 Dewatering Management Plan_Rev0_01.05.25                                                      Page 15




Document Set ID: 23735664
Version: 1, Version Date: 12/05/2025