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

                                                                                                              ADG Consulting Pty Ltd

                              ingesting 2L of the recreational water solution per day. ANZECC/ARMCANZ (2000) Section 5.2.3.3, notes
                              that as a general guideline, under Toxic Chemicals, ‘Higher concentrations of toxicants may be tolerated
                              occasionally if it assumed that no person will ingest more than a maximum of 100 mL water during a
                              normal swimming session (NHMRC 1990) compared with 2L/d for potable water’, and Section 3.1.1.3,
                              under Risk based approach of the guidelines, ‘The guideline trigger values are based on bioavailable
                              concentrations, and hence are relatively conservative when compared with total concentrations in the
                              field, so the use of the decision frameworks will increase guideline concentrations in most cases’.
                              Therefore, any chemical toxicant trigger values would require reassessment and likely increase upwards
                              of any ANZG 2018 &/or ANZECC/ARMCANZ (2000) Guideline trigger values due to the slightly to
                              moderately disturbed nature (and thereby reduced sensitivity) of the receiving waters.

                              In conditioning more onerous criteria, rather than the available marine chemical toxicant trigger value
                              criteria contained within the ANZG/ANZECC Guidelines, an unachievable constraint may be placed on the
                              development. This DMP has allowed for contingency measures to be incorporated into the treatment
                              and discharge system if required, including silt curtains to be installed within the receiving waterway
                              surrounding the discharge location, or further onsite treatment measures such as filtration, to prevent
                              and/or minimise as far as reasonably practicable the potential for release of suspended solid loads into
                              the broader receiving waterway.




                        ADG1777.25 Dewatering Management Plan_Rev0_01.05.25                                                     Page 9




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