Attachment E - Stormwater Management Report · MCU24/0112

                                   Figure 2 - MUSIC layout for development

The developed site treatment train effectiveness is outlined in Table 2.

Table 2 - Treatment train effectiveness.

       Modelled Parameters              Source nodes             Residual load          % Reduction

 Flow (ML/yr)                                3.04                     3.04                    0

 Total Suspended Solids (kg/yr)              413                      80.2                   80.6

 Total Phosphorus (kg/yr)                   0.894                     0.268                   70

 Total Nitrogen (kg/yr)                      6.31                     2.79                   55.8

 Gross Pollutants (kg/yr)                    70.7                     1.07                   98.5

Based on the MUSIC modelling results in Table 2 above, the proposed treatment train achieves the
required pollutant load reduction objectives for all pollutants. The proposed proprietary treatment
measures are therefore considered adequate for the development. Further review and refinement of
the water quality treatment measures should be undertaken at the detailed design phase.

4. 3   Con st ruc t io n Ph a se

Management of stormwater runoff during construction and the implementation of an erosion & sediment
control program is necessary to avoid impacts to receiving waters from pollutants typically generated
during the construction phase. Typical pollutants are described in Table 3 below:

Table 3 – Pollutants Typically Generated During the Construction Phase

          Pollutant                                           Sources

 Litter (Gross Pollutants)    Paper, construction packaging, food packaging, cement bags.

 Sediment                     Unprotected exposed soils and stockpiles during earthworks and building.

 Hydrocarbons                 Fuel and oil spills, leaks from construction equipment.

 Toxic materials              Cement slurry, asphalt prime, solvents, cleaning agents, wash waters.



                                                                                                      4