Negotiated Report (Representations made) MCU24 0125, OPW24 0150 & RAL24 0021 (As Published) · MCU24/0125

                              ii.       Ensure clean stormwater is diverted/managed around or through the site
                                        without increasing the concentration of total suspended solids or other
                                        contaminants in the flow and without causing erosion (on-site or off-site). If it is
                                        not feasible to divert all areas discharging clean stormwater around or through
                                        the site, the clean stormwater runoff is managed in the same manner as
                                        contaminated stormwater runoff and ensures that sediment basins are sized to
                                        accommodate the additional volume of runoff.
                             iii.       Prior to each rainfall event ensure concentrated stormwater flow paths are
                                        provided with capacity in accordance with IECA (2008) Table 4.3.1 and do not
                                        cause water contamination, rill or gully erosion, sedimentation or damage to
                                        structures or property.
                      c.      Minimise sediment released from the site:
                              i.        All site sub-catchments greater than 2,500m2 in area, are to be provided with
                                        sediment controls which are designed, implemented and maintained to a
                                        standard which would achieve at least 80% of the average annual runoff volume
                                        of the contributing catchment treated (i.e. 80% hydrological effectiveness) to
                                        50mg/L Total Suspended Solids (TSS) or less, and pH in the range 6.5–8.5.
                                        Where this is proposed to be achieved through the use of sediment basins, the
                                        following applies:
                                        A. each basin is sized and operated in accordance with either a Type-A or
                                           Type-B sediment basin as documented in IECA (2008) Appendix B (June
                                           2018) unless otherwise justified, based on the contributing catchment area
                                           including undisturbed catchments which cannot be diverted;
                                        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:



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Document Set ID: 23843933
Version: 14, Version Date: 05/09/2025