18164 - SBSMP - Rev 0

                                                                                          18164 - SBSMP/0
                                                                                                         Page 11




6.3 Operational Phase
Water quality objectives (WQO’s) for South East Queensland as set out in State Planning Policy
2017 (SPP 2017) should be achieved by identifying and adopting best practise techniques in
accordance with the abovementioned guidelines. Refer to Table 6.3 for the target WQO’s.

                           Table 6.3 – Minimum Mean Annual Load Reductions

                                                             Minimum Mean Annual
                                     Contaminant
                                                                Load Reductions

                            Total Suspended Solids (TSS)              ≥ 80%
                               Total Phosphorus (TP)                  ≥ 60%
                                Total Nitrogen (TN)                   ≥ 45%
                               Gross Pollutants (GP)                  ≥ 90%

Additionally, in order to satisfy Council’s condition no. 22(c) under application no. MCU16/0153
REC16/0041, the annual loads for the abovementioned contaminants from the post developed site
must be less than the annual loads from the pre developed site.

6.3.1 Sources of Contaminants
Potential sources of contaminants and stormwater quality improvement devices identified for the
operational phase of the development are outlined in Table 6.4.

                                   Table 6.4 - Sources of Contaminants

                                                 Pollutant
               Target Pollutant Type                              Acceptable Treatment Examples
                                                   Size

         Primary        Screening of gross                      Litter baskets, swales, buffer strips,
                                                 >5000um
        Pollutants          pollutants                               GPT’s, Bio-retention basins

                        Sedimentation of
       Secondary                                 125um -
                        coarse to medium                        Swales, sedimentation basins, ponds
       Pollutants                                5000um
                            sediment
                                                                 Bio-retention basins, constructed
                           Enhanced
                                                   10um –      wetland macrophyte zones, other bio
                      sedimentation of fine
                                                   125um         technologies, proprietary tertiary
                          particulates
                                                                    stormwater treatment dvices
         Tertiary     Adhesion and filtration                 Constructed wetland macrophyte zones,
                                                 0.45um –
        Pollutants    of very fine / colloidal                  other bio technologies, proprietary
                                                   10um
                             sediment                          tertiary stormwater treatment dvices

                       Biological uptake of                   Constructed wetland macrophyte zones,
                                                 <0.45um
                        dissolved particles                           other bio technologies


6.3.2 Proposed Treatment Train
The proposed treatment train has been modelled using the following methodology:

    1. Roofwater runoff from each proposed residential dwelling will be collected a 3kL water
       reuse tank with overflow to the internal drainage network and directed to the proposed
       bio-retention basin for treatment.


Site Based Stormwater Management Plan
Reconfiguration of a Lot and Mixed Use Development at 215 David Low Way, Peregian Beach