RFI - Attachment B - Stormwater Quality Engineering Response · 132008.1128.04

Memorandum
18-001942 - Sunrise Beach Interim RAC Water Quality




              Figure 2 - Treatment Train Effectiveness at the Bioretention Basin Outlet (Prior to Infiltration)



The below figure is the MUSIC output for the treatment train effectiveness of the RAC site in the interim stage. As can be
seen the necessary 80% reduction for TSS, 60% reduction for TP, 45% reduction for TN and 90% reduction for GP are
being achieved.




                                Figure 3 - Treatment Train Effectiveness for the RAC Site

The above investigation has been completed to confirm the RAC site can sufficiently achieve water quality reductions for
the RAC site in the interim Stage 1. As part of future works on the RL site a large bioretention basin has been proposed
and once completed negates the need to include the above mentioned infiltration basin in the MUSIC modelling.

Erosion and sediment control measures must be suitably designed, constructed and maintained throughout the
construction phase of the development.




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