RFI - Attachment H - Stormwater Management Plan_Issue C_

15 May 2019


Rubbish bins will be located within the building and car park for use by staff and visitors. The carparks
will be cleaned regularly. As a result of this and with the installation of the treatment devices, levels of
litter exiting the site via stormwater are expected to be negligible.

5.3.3.8.2       Sediment
The TSS outflow is identified in Table 5 above. As can be seen from the above table the pollutant load
reduction achieves the Water Quality Objectives. The TSS level is therefore considered acceptable.

5.3.3.8.3        Nitrogen and Phosphorous
The TN and TP loads are identified in the above Table 5. As can be seen the TN and TP loads leaving the
site achieve the Water Quality Objectives. The Nitrogen and Phosphorous residual loads are therefore
considered acceptable.

5.3.3.8.4     Hydrocarbons
Hydrocarbons will become trapped within the filter cartridges.

The hydrocarbons will be removed during the maintenance of the filter cartridges.

5.3.3.9 Surfactants
Washing of cars is not expected on site for the proposed development, as a result surfactants should not
be an issue for the drainage system.

5.3.3.9.1       Heavy Metals
Heavy metals in stormwater runoff generally become attached to fine sediment. The filter cartridges
will remove the majority of this fine sediment. The removal of the fine sediment should effectively
remove most of the heavy metals in the runoff.

5.3.3.9.2       Pathogens/Faecal Coliforms
Domestic animals within the development will be under the control of their owners at all times and the
owners will be expected to clean up after them.

5.4       Proposed Stormwater Quality Treatment Devices

5.4.1 Locations

The location of the proposed stormwater quality treatment device is shown on MPN Plan 7700-DA.01
attached in Appendix 3.
The devices will be located within the carpark drainage systems and within the detention tank located
on site.

5.4.2 Device and Size

The device type and size are depicted on MPN Plan 7700-DA.01 attached in Appendix 3.
The devices to be installed on site are mechanical filtration devices which have been sized to cater for
the development type and use.

The mechanical treatment devices have been used with success within many Australian Council areas to
ensure that stormwater runoff is treated to meet the local and state requirements.

5.4.3 Operation

The Stormwater 360 stormfilters will treat stormwater runoff from all surfaces within the proposed
development.



Excellence with Economy in Engineering                                                                         14
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