Pondering the pond’s purity

BY TOMMY BOUTROS

‘Extremely high’ levels of cancer-causing chemicals were found in a waterway adjacent to Sydney Airport. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were detected by researchers from the University of NSW in water tests of the Mill Stream, which runs from a pond in the Lakes Golf Cub in Mascot, alongside the eastern edge of the airport and into Botany Bay.

Associate Professor Stuart Khan and senior research associate Dr James McDonald from the University of NSW sampled water from 14 sites across the southeast of Sydney, including beaches, bays and ponds.
They found all of them contained multiple contaminants from stormwater run-off and sewage leaks, but many showed levels of PFOS and PFOA, particularly the Mill Stream.
PFOS and PFOA, once used in an assortment of household cleaning products, were phased out in December 2003, yet they are surprisingly resistant to degradation.
At 421 ng/L the affected water in the Mill Stream was six times the safe drinking average.

Fears that ponds in Centennial Park were also contaminated by PFOS and PFOA, posing a risk to nesting birds and wildlife, have proved unfounded.
However, the University of NSW claimed the three Centennial Parklands ponds showed positive readings for herbicides, pesticides, caffeine and paracetemol, which indicate that stormwater that fed into the ponds was contaminated at some stage by sewage.
However, Amara Glyn, Centennial Parklands Environmental Officer, disputes that there is a risk to the public.
“Centennial Parklands received the water quality results and data from the University of New South Wales and the data does not imply a significant public health risk in Centennial Park,” she said. “Nor does it imply a public health risk associated with any of the specific chemicals measured at any of the sites tested.
“Centennial Park’s ponds are physically linked to each other via a series of sluices and pipes, and also to the outside world via a number of major stormwater inlets.”
“The catchment for stormwater runoff covers about 600 hectares of which the Parklands themselves make up about 45 per cent. The Parklands works closely with the Local Land Services, Sydney Water and local councils to minimise stormwater runoff pollution.”

The NSW Environmental Protection Agency is conducting a state-wide investigation into PFOS and PFOA urban pollution which includes reviewing the results from the fourteen sites Prof Khan and Dr McDonald tested.