Darwin residents have been warned to avoid two creeks polluted with toxic firefighting chemicals, as the Department of Defence continues to grapple with the emerging contamination scandal.
Defence has been investigating the extent of contamination in waterways around its air force base in Darwin, where per- and poly-fluoroalkyl substances (Pfas) were used in firefighting foam for decades.
Pfas has been shown to share a probable link with cancer and pregnancy-induced hypertension, and is highly persistent in the environment. The chemicals bioaccumulate, meaning they build up in living organisms over time.
On Wednesday night, the department told the local community of results of nine months of ongoing investigations into the contamination caused by its air force base. Drains leading into two creeks – Rapid Creek and Ludmilla Creek – showed significant levels of Pfas, it said.
Defence confirmed its advice that recreational activities should be avoided in the two creeks, which are poplar fishing spots, particularly with local Indigenous groups.
Water from those creeks is also not suitable for drinking, although most of Darwin’s water supply comes from a separate source, and is considered safe.
Defence also confirmed earlier investigations by the Northern Territory government that elevated levels of Pfas have been found in seafood, but that it was still safe to eat in small volumes.
Defence spokesman Steven Grzeskowiak said the department’s initial findings were broadly the same, and assured residents who live in the area that their bore water was safe to drink.
However, homegrown produce on these properties could pose a health risk because of Pfas concentration in soil.
Defence will undertake further analysis for both dry- and wet-season conditions, and a human health study due in late April will determine whether blood tests are needed for Darwin residents.
The Pfas contamination scandal has, so far, been concentrated in three locations: Williamtown in New South Wales, Oakey in Queensland, and Katherine in the Northern Territory.
Defence has faced criticism for its handling of the issue. It was warned of potential dangers with its firefighting foam in the 1980s, and the Australian government was repeatedly warned of the chemicals’ toxicity years before it began a gradual phase-out of their use in 2004. The contamination has caused health fears, losses in property values, and considerable anxiety and distress.
Defence is now facing two class actions from Oakey and Williamtown residents. Katherine residents are also considering a separate case.
Grzeskowiak noted that in Katherine, Williamtown and Oakey, where free testing has already been offered, people have historically been drinking contaminated water. “And we have not found that to be the case here in Darwin,” he said.
This week, the government announced an assistance package for Katherine, three hours’ drive south of Darwin, where contamination has been caused by decades of Pfas use at the town’s air force base, RAAF Tindal. The $5.7m package will include free blood tests for residents.
Pfas was manufactured by multinational giant 3M, which maintains there is no consistent evidence that it causes adverse health effects.
Australia’s military, fire services, and airport authorities imported large quantities of foam products containing Pfas, including the most toxic 3M Light Water.
The federal government was directly warned about its toxicity and persistency by the US Environmental Protection Agency as early as 2000.
