Stormwater and associated sediments at Perth’s marine beaches are contaminated predominantly with microbes and heavy metals. Nutrients, petroleum hydrocarbons, organic chemical compounds and suspended solids are also present in stormwater but to a lesser extent.
These findings were a result of the first comprehensive baseline study of the types and concentrations of contaminants in and around 65 stormwater drains in the Swan Region.
The drains were located in nine regions defined by the Cities of Wanneroo and Joondalup and the Towns of Cambridge and Cottesloe. The City of Stirling was further divided into the regions of Stirling and Scarborough, and the City of Rockingham into the regions of Rockingham, Shoalwater and Safety Bay.
The catchments for these drains consisted mostly of coastal roads, public car parks and reserves.
Although the types of contaminants reflected those expected from these types of catchments, the concentrations of some of the contaminants were far greater than expected.
