Reference Document MCU22-0102 Stormwater Management Plan

SQIDEP Evaluation                                                  SPEL Basin, Sippy Downs


Performance Claim
The SPEL Basin performance claim is as follows:




This Body of Evidence (BOE) claim is based only on field test results from the Sippy Downs
test site. It is not based on any overseas test data.

It is noted that gross pollutants were not tested however the system tested includes a SPEL
Storm Sack draining into a stormwater pit. It is reasonable to assume that any gross
pollutants (particle size > 3mm) would be captured in the Storm Sack component of the
device. Even if the Storm Sack were to blind and go into bypass the gross pollutants would
be captured (up to the high flow bypass rate) within the stormwater pit upstream of the basin.

It is important to note this claim includes the performance benefit of both a Storm Sack and
the SPEL Basin filtration components so that any MUSIC model should not have a SPEL
Stormsack placed upstream of the device as its already included in the overall performance.

Hydrocarbons were not tested and the claim was revised to exclude it.

Site Background and Assumptions
The catchment is a small road catchment in Sippy Downs, Sunshine Coast. The catchment
was checked for changes across the monitoring period (March 2017- April 2018). Aerial
photography was taken across this period as can be seen below in Plates 1 to 4.

The broader catchment was maturing across the period, though no specific changes to the
road catchments are seen. It is suspected that some of the developing catchment loads may
have been transported into the monitored catchment in the early parts of the monitoring
program. Otherwise the catchment seems to be in typical condition and suitable for
monitoring.




                                                                                             8