Amended Stormwater Managment Plan

SC5594 – Walter Hay Dr, Noosaville                                                              10




3.3.3.2 Treatment Nodes
The following devices have been used in the treatment train to reduce these pollutant loads to achieve WQO’s.


    Bio-Retention Basin – An area of 100m2 of designated Bio-retention to treat carpark, landscape, and
    roof catchments to achieve the WQO’s was modelled. An extended detention depth of 200mm with a
    filter media of 200mm/hr sandy loam hydraulic conductivity has been modelled. The location of these
    devices is shown on the attached Appendix A.



3.3.4    Effectiveness in Pollution Reduction
The water quality development model was set up with the incorporation of the above devices to reduce
pollutant export to WQO levels. Table 3.6 indicates the predicted pollutant mean values of stormwater
discharged as calculated by MUSIC:


                                     Pollutant             Percentage Load Reduction

                        Total Suspended Solids (TSS)                  87.1%

                            Total Phosphorus (TP)                     61.8%

                              Total Nitrogen (TN)                     55.5%

                           Gross Pollutants (>5mm)                    100%

                                     Table 3.6 - Flow Based Pollutant Load Reduction



The MUSIC modelling results shown above indicate that the treatment train will adequately treat TSS, TP
and TN generated by stormwater runoff in accordance with the targets required under the water quality
objectives stated previously.