Negotiated Decision Notice - MCU24 0125, OPW24 158 & RAL24 0021 (As Published) · MCU24/0125

                                           B. each Type-A or Type-B sediment basin is to be provided with an automated
                                              system of flocculant dosing and a suitable supply of flocculant/coagulant,
                                              with the type of flocculant/coagulant determined based on Chemical
                                              Coagulants and Flocculants Fact Sheet (IECA, 2018);
                                           C. markers are provided within each basin indicating the maximum sediment
                                              storage level and any additional water storage capacity for water reuse;
                                           D. during discharge from the primary outlet system, the concentration of total
                                              suspended solids (TSS) discharged does not exceed 50mg/L and that pH
                                              is within the range of 6.5-8.54. These discharge standards apply equally to
                                              any intentional release of any water captured or stored within the site;
                                           E. The hydraulic structures such as inlets, outlets, spillways must be
                                              structurally sound for the design events as specified in IECA (2008); and
                                           F.   The sediment basin is to be constructed and operational before any
                                                disturbance occurs in the catchment upslope of the basin. Accumulated
                                                sediment from basins and other controls is to be removed and disposed of
                                                appropriately without causing water contamination.
                              ii.          For site sub-catchments less than 2,500m2 in area and where it is not feasible
                                           to divert runoff from these small disturbed areas of the site to a sediment basin,
                                           compensatory erosion and sediment controls are implemented prior to rainfall
                                           to ensure that erosion of those of areas is minimised and Type 2 or Type 3
                                           sediment controls are provided in accordance with IECA (2008).
                             iii.          Controls are to be installed to minimise the tracking of dirt from the site onto
                                           roadways. Any dirt on roadways caused by vehicles leaving the site is to be
                                           removed without causing water contamination, prior to rainfall and at least at
                                           the end of each work day.
                      d.      Manage works within waterways:
                              i.           Waterways, including perennial and permanent waterways, are not to be
                                           altered, nor riparian (including rehabilitated) vegetation disturbed without prior
                                           written approval of the relevant administering authority.
                              ii.          Work within waterways is to be:-
                                           A. only undertaken during the lower rainfall months;
                                           B. promptly rehabilitated conforming to the natural channel form, substrates
                                              and riparian vegetation as far as possible; and
                                           C. undertaken in accordance with Best Practice Erosion and Sediment
                                              Control, Appendix I – Instream works, Sections 14 and 16, (International
                                              Erosion Control Association, 2008).
                                    iii.   Temporary vehicular crossings of waterways are to be designed and
                                           constructed to convey flows for the 63%AEP and remain stable for all rainfall
                                           events up to the 10% AEP event of critical duration.
                                iv.        ESCs are not to be constructed within the riparian buffer zone, unless it is not
                                           feasible to site them elsewhere, and then only within cleared areas.




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Document Set ID: 24095782
Version: 12, Version Date: 05/09/2025