Information Response - Email 1 of 2 MCU16/0153 & REC16/0041

                                             STORMWATER MANAGEMENT PLAN
      Client: Thomco (No 2087) Pty Ltd                              Location: 215 David Low Way, Peregian Beach



          Table 2 – Site stormwater quality objectives (as per WQO’s for Wallum Tannin-stained Streams)
                                 Pollutant                           Water Quality Objectives
                 Turbidity                               <20 NTU
                 Suspended Solids (SS)                   <6 mg/L (annual mean concentration)
                 Chlorophyll a                           <5 µg/L
                 Total Nitrogen                          <500 µg/L (annual mean concentration)
                 Oxidised N                              <60 µg/L
                 Ammonia N                               <20 µg/L
                 Organic N                               <420 µg/L
                 Total Phosphorus                        <50 µg/L (annual mean concentration)
                 Filterable Reactive Phosphorous
                                                 <20 µg/L
                 (FRP)
                 Dissolved Oxygen (% saturation)         85 – 110 % saturation
                 pH                                      5.0 - 7.0
                 Secchi Depth                            N/A
                 Conductivity                            500 µS/cm
                                                         Aim for no visible oils, petrochemicals, films or
                 Hydrocarbons
                                                         odours
                 Litter                                  Aim for no anthropogenic material greater
                                                         than 5 mm in any dimension.

3.2          Area of Treatment
      The total area of the proposed development is approximately 1.165 ha consisting of groundcover,
      roof area and road area. With the topography of the site and the proposed development layout, the
      entire site can be treated for water quality purposes.
      The treatable area of the site has been divided into three (3) catchments. The three (3) catchments
      are discussed further in Section 4.2 and can be seen in the Preliminary Stormwater Management
      Layout in Appendix B.


      4.0 WATER QUALITY MODELLING ASSESSMENT/APPROACH
4.1          Scenario Methodology
      The site was modelled using split catchment source nodes, comprised of roof area, road area and
      groundcover nodes.
4.2          Proposed Stormwater Treatment Train
      The following mitigation measures are proposed for the overall stormwater management at the site.
      Stormwater runoff from the site will be treated by three (3) bioretention basins prior to discharge off
      site.




      Covey Associates Pty Ltd                               6                                    Project No: 162042
      Consulting Engineers                                                                         100949Rpt Issue B