Minor Change Existing Approval OPW19 0266 03 · OPW19/0266.03

                      (a)     Minimise Erosion
                              (i)       For areas of the site which drain to a sediment basin, implement drainage and
                                        erosion control measures prior to rainfall which prevent or minimise rill erosion
                                        and gully erosion;
                              (ii)      For areas of the site which do not drain to a sediment basin, implement drainage
                                        and erosion control measures prior to rainfall (including contingency measures)
                                        which prevent or minimise erosion, including rain drop erosion, chemical erosion,
                                        rill erosion and gully erosion;
                              (iii)     Prior to the sealing of the plan of survey for the development, all site surfaces
                                        must be effectively stabilised using methods which have achieved effective short-
                                        term stabilisation and which will continue to achieve effective stabilisation in the
                                        medium to long-term. For the purpose of this condition, an effectively stabilised
                                        surface is defined as one that does not, or is not likely to result in visible evidence
                                        of soil loss caused by sheet, rill or gully erosion or lead to sedimentation, or lead
                                        to water contamination.
                      (b)     Manage concentrated stormwater flows
                              (i)       Prior to each rainfall event ensure concentrated stormwater flow paths are
                                        provided with capacity in accordance with IECA (2008) Table 4.3.1 and are
                                        structurally stable in all rainfall events for the following sources:
                                      (a) From stormwater catchments upslope of the area of disturbance which are
                                          either stable or external to the site, ensure stormwater is diverted or managed
                                          either:
                                         (i) around the site or through the site without causing erosion and without
                                             contaminating the flow; or
                                         (ii) if it is impractical to convey the flows around or through the site, convey the
                                              flows into appropriately sized sediment basins without causing erosion
                                      (b) From all disturbed areas of the site to sediment basin(s) without causing erosion
                      (c)     Minimise sediment released from the site
                              (i)       Install and maintain sediment basins for each disturbed catchment area of the
                                        site and including undisturbed catchments which cannot be diverted, such that:
                                      (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).
                                      (b) Each 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 6.5-8.5 unless entering a naturally acidic environment.
                              (ii)      Install and maintain additional sediment control measures within the site, as
                                        necessary to maximise sediment capture.
                              (iii)     Minimise the tracking of dirt from the site onto roadways. Ensure that all dirt on
                                        roadways caused by vehicles leaving the site is removed without causing water
                                        contamination, prior to rainfall and at least at the end of each work day.




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Document Set ID: 22642068
Version: 2, Version Date: 31/10/2023