Dr Eric Donaldson, who lives next door to the Oakey Army Aviation Base, became the first person in Australia to reach a confidential settlement with the government for a claim over contamination from toxic firefighting foam chemicals.

The landmark case was negotiated by Dr Donaldson's son, Adair Donaldson, the director of Toowoomba law firm, Donaldson Law.

Dr Donaldson didn't join a class action, choosing instead to settle the matter outside the courts in a confidential agreement.

Adair Donaldson said his father was relieved about the outcome and would love to see "all claims" resolved.

"My father is incredibly relieved. He is glad that it is all over. He is someone who has been at the forefront of this issue for a long time," Mr Donaldson said.

"It was actually a very personal matter for me because it was our family property that was impacted by the contamination of the groundwater."

He said the settlement had no impact on any other claims and there was no admissions to liability.

"A large amount of people have decided to join a class action and I wish them all the best and I hope they get a great outcome," he said.

"In our situation we chose to negotiate directly with the commonwealth."

He said it was a complex matter which was not related to any personal injury claims.

The case is separate to ongoing class actions bought by residents living in Williamtown, Katherine in the Northern Territory and Oakey.

In all three towns, land and drinking water has been tainted with toxic per- and poly-fluoroalkyl chemicals (PFAS), manufactured historically by chemical giant 3M and used for decades in fire retardants at Australian military bases and fire stations.

Coalition Against PFAS president Lindsay Clout congratulated Dr Donaldson on Wednesday, but demanded to know why other residents hadn't been compensated.

Mr Clout, who is from one of about 750 households caught in a plume of contamination from the Williamtown RAAF base, said everyone impacted by the pollution scandal deserved a "fair go".

"Why is it that for four years the government has ignored the people of Williamtown, Oakey and Katherine every time they have proposed an out-of-court framework," he said.

"But now, with a Federal Court trial and a federal election looming, a solution is suddenly found, but for only one person."

Federal Member for Groom John McVeigh said Defence Legal has received 45 non-litigated claims and two claims had been resolved under existing departmental policy initiatives.

Mr Clout called on the Morrison government to clean up the pollution, compensate residents and be transparent.

Dr Donaldson previously told the media that much of the immediate human health impact has been "negative anxiety" experienced by those potentially impacted from the PFAS chemicals.

The former aviation doctor took it upon himself to arrange the blood tests that would become the precursor to the Defence-endorsed testing.

It's understood he has been working with Landcare to turn parts of his property where the groundwater is affected by the chemical into a koala sanctuary.