Why not eliminate Williamtown PFAS at the source?
by Grant Scott · Newcastle HeraldWilliamtown has been Australia's reference case for PFAS for more than a decade.
It gave the country the phrase "red zone", the first residents on tank water, the first class action, and now the Commonwealth's $2 billion claim against 3M.
Defence has been remediating since 2018, and since March a plant on the south-western boundary has been pulling a million litres of contaminated groundwater a day out of the ground.
That plant is doing what it was built to do. But it was built to manage the problem, not to end it.
There is now an option to eliminate PFAS at its source rather than treat it at the boundary indefinitely. Why isn't that the plan?
Decades of firefighting foam left PFAS in the ground under six areas of the base. Rain and groundwater have carried it outward ever since, forming a plume that now reaches Fullerton Cove.
Pumping and treating groundwater captures PFAS that has already left. It does nothing about what is still releasing PFAS every time it rains: the old fire training area, the fire station and foam-testing pad, Lake Cochran, the sewage and trade-waste plants, the refuelling yard.
And it is not only the soil.
Defence's own investigation found PFAS had soaked into the pavements at the source areas and would keep leaching.
A pad sprayed with foam for 30 years gives PFAS back a little at a time, indefinitely, unless it is treated or sealed. So do the drains, pits and bunds.
Defence's monitoring says PFAS around the source areas has come down, but concentrations across the wider management area "remain broadly the same".
Defence attributes that, fairly, to decades of migration.
The community is being asked to accept that lag. That is reasonable only if every source behind the plume is being eliminated, completely and measurably, so the lag is finite and the plant has an end date.
Here is what has changed. In 2015 the choices for a contaminated hardstand or a sediment-filled drain were to leave it, or dig it out and truck it to landfill.
Contaminated soil, sediment and crushed concrete can now be locked up in place so the PFAS is bound and stops leaching, and the material reused on site as fill or pavement.
Drains and runoff paths can be sealed. New concrete can be specified so it does not take up PFAS in the first place.
None of this is exotic, and over the life of a site it is cheaper than an open-ended pumping bill.
It does not replace the treatment plants. It eliminates the reason they have to keep running.
The NSW EPA has, in effect, said the same thing. It will not decide on the areas south of the base until Defence has implemented the Cabbage Tree Road groundwater extraction. That is a regulator waiting for source-side action before it will move the boundary.
Residents south of the base have been waiting for the same thing since 2015.
One number would settle it.
Litres treated and tonnes of soil handled are the figures that reach community fact sheets. The figure that decides Williamtown's future is the mass of PFAS leaving each source area and crossing the base boundary each year, and whether it is falling towards zero.
Defence has the monitoring network and the groundwater model to produce that number, source by source. Publishing it would show which sources are finished, which are still contributing, and when the plume should respond.
Defence is not the villain here. It inherited a problem created by a product it was told was safe, and has spent heavily trying to fix it.
But 10 years in, with a working group at the table, an EPA review pending and a million litres a day going through the plant, Williamtown is the right place to ask the next question.
Not how much water has been treated, but how much PFAS is still getting out, from where, and what it would take to eliminate it.
The residents of the red zone have waited long enough for the answer to be a date rather than a volume.