Environmental campaigner and legal activist Erin Brockovich says there are “disturbing” comparisons between chemicals from toxic firefighting foam affecting parts of Australia and the case that made her famous.

Ms Brockovich is visiting Australia to support a class action lawsuit against the Department of Defence over contamination by per- and poly-fluoroalkyl substances (PFAS).

She told nine.com.au today Australia has a "huge problem" despite government assurances.

Firefighting foam used at defence bases throughout the country, including the Northern Territory and Queensland, contained the PFAS chemicals for decades.

It has since been revealed it leaked into soil and the water system.

Toxic firefighting foam has been linked to chemical contamination at sites around Australia.

The Federal Government was advised by an independent panel that while there was negligible evidence to link exposure to PFAS chemicals with human disease, health effects could not be dismissed.

Ms Brockovich, 58, is an ambassador for Shine Lawyers, which has begun lawsuits against the Defence Department in Katherine in the NT and Oakey in Queensland. The law firm is also investigating sites in Western Australia and Victoria.

Six hundred properties outside of Newcastle in NSW and within a 5km radius south of an RAAF base are also affected by PFAS contamination.

The residents of Williamtown in the Hunter Region of New South Wales have been affected by PFAS leaks. (Nine)

The government continues to supply some Williamtown residents with bottled water. (A Current Affair)

Ms Brockovich told nine.com.au the PFAS issue in Australia was playing out a “very familiar scenario” to her water contamination campaign during the 1990s, which became the subject of a film starring Julia Roberts.

“There is a similar conflicting message being put out that this can’t harm you, yet you cannot drink the water.”

“And it’s affecting cattle and other livestock. Farmers with poisoned herds are being told by the government ‘don’t eat the meat’, but they’re being allowed to sell it.

“Where is the consistency?”

In 1993, Ms Brockovich, a beauty pageant champion and single mother with no formal legal training, was the brains behind one of the largest pollution lawsuits in US history.

Legal activist and environmental campaigner Erin Brockovich. (Getty)

The billion-dollar Pacific Gas and Electric company was forced to pay out US$333 million after she brought the case over its leaking of the chemical chromium into drinking water in the Californian town of Hinkley.

Ms Brockovich has been touring some of the communities affected by PFAS contamination on behalf of Shine Lawyers.

In the US, cancer victims have been awarded multi-million court payouts for being exposed to plumes of PFAS waste.

Ms Brockovich says the technology exists in Australia to remedy the problem, but points to a lack of urgency.

Julia Roberts and Albert Finney in the film Erin Brockovich. (Supplied)

“The science is clearly in,” said.

“There’s solutions to these problems, why are we not fixing them? Cause we don’t want to spend the money up front and we’d rather just poison everybody and run it out and see if we can get away with it?”

Ms Brockovich, a champion of the underdog, today advised to people affected by PFAS contamination is to “get involved”.

“Let them know you’re mad. Get involved by joining councils and civic bodies. I’ve never been afraid of causing disruption.