Federal Court hears 'daunting' $2B PFAS case against 3M over defence base contamination

Inside a Melbourne courtroom on a winter morning, Justice Catherine Button sat down to begin hearing what may be the most sprawling environmental lawsuit Australia has ever mounted against a foreign corporation. The Commonwealth was seeking $2 billion from 3M, the American chemical manufacturer, over contamination at twenty-eight defence bases scattered across the country. Before the first substantive arguments were even made, the judge stopped and said something that seemed to capture the weight of what lay ahead: she had never seen anything like this, and calling it daunting would be an understatement.

The contamination in question came from firefighting foam—specifically, foam containing PFAS chemicals that the military had sprayed on runways and training grounds for decades. PFAS stands for per- and polyfluoroalkyl substances, a class of synthetic chemicals that do not break down naturally in the environment. Once released into soil and groundwater, they persist. At some of the defence sites, contamination plumes had stagnated in place. At others, the chemicals had migrated into water supplies, pushing levels above what is considered safe to drink. The Commonwealth's case rested on a single core allegation: that 3M knew about these risks because it had conducted its own environmental testing, including studies on animals that showed the chemicals were persistent and toxic, but the company had withheld those results from regulators and the public.

The scale of the claim was staggering. The Commonwealth had filed a 1,600-page statement of claim detailing the alleged contamination across all twenty-eight sites. The government was not seeking to recover the cost of a single cleanup or a single investigation. It was seeking to recoup the entire bill for investigating, managing, and remediating contamination from the legacy use of this foam—a bill that had grown to two billion dollars. In March, when the Commonwealth first announced the lawsuit, officials called it the largest legal claim ever brought by the federal government against a private company.

3M's response was measured but firm. The company said it would defend itself through the legal process. It noted, somewhat pointedly, that it had stopped selling the foam in Australia two decades ago—yet the Department of Defence had continued using existing stocks long after that. The company was not admitting liability. This was significant because 3M had faced similar litigation elsewhere. In 2023, it had settled a claim brought by American public water providers for $14.5 billion, agreeing to fund testing and treatment of PFAS contamination in U.S. water systems. But that settlement, too, came without an admission of wrongdoing.

What became clear during the first case management hearing was that a traditional trial would take years—perhaps longer than anyone involved would remain in their current role. Justice Button said the matter could not run on conventional tracks or it would never reach resolution. Instead, she agreed to an expedited approach: 3M would plead guilty or not guilty to claims relating to just six of the twenty-eight defence bases by the end of the year. These six sites had been selected to represent the range of contamination problems the Commonwealth had documented—stagnant plumes, exceeded drinking water thresholds, ongoing migration. If the parties could narrow the scope this way, they might be able to identify the core scientific and legal disputes without litigating all twenty-eight sites from scratch.

Philip Solomon, the King's Counsel representing 3M, told the court that his team was substantial: four barristers and a large supporting legal staff, all dedicated to what he called the most complex matter he had ever encountered. He warned that 3M's defence would involve intricate science, with five separate limbs of liability and four separate limbs of causation to work through. The Commonwealth's barrister, Fiona McLeod AO SC, countered that the case was not as new as 3M suggested—the Commonwealth had been preparing its claim for some time, and the 1,600 pages reflected genuine investigation, not rushed work.

The court set a schedule. The parties would return on October 16 to confirm which six bases 3M would enter pleas to. 3M would file its full defence by December 11. From there, the case would move into the substantive phase, where the real work of proving or disproving contamination, causation, and liability would begin. For now, the machinery of the law had been set in motion, and everyone in the room understood they were embarking on something that would consume years and test the limits of environmental litigation in Australia.