Moyne Shire councillors recently voted to adopt recommendations to protect the sites, including using the money to build a rock wall in front of a state government site once used to deposit night soils until the early 1980s.

A rock wall built in 2014 protects the second site, a council landfill that operated from the early 1970s until 1998, but erosion has continued at the sides of the 280-metre long structure.

No one knows exactly what material, and how much of it, was buried at the two sites with the council to also investigate what lies beneath the sand.

Kevin Elliott worked at the council-operated tip in the early 1990s and recalled an excavator digging trenches that were 30 metres long and 15 metres wide to deposit household rubbish.

"It was a fair trench, people would come out and dump their rubbish in there. Once the hole was full it was covered over with sand and they dug another one," Mr Elliott said.

"The town's waste collection that was done once a week was also deposited in there. It was basically just household rubbish."

He said he was oblivious to the future challenge to the council or threat to the environment while working at the tip and years later he has helped council contractors locate the trenches.

"I grew up on a farm so that sort of thing was normal, everyone had a tip on their own farm," Mr Elliott said.

"You can see where they were, over the years rubbish melts down and it sinks. You can see the indentations in the ground where the trenches were."

Council mayor Mick Wolfe said the tips posed a risk to the environment with wave action previously known to have exposed rubbish from the dunes.

"No one cared in those days, it was just bring your fridge, bring your washing machine. It was just dumped," Cr Wolfe said.

"There would be no one who could account for what's in there at the moment. That's the concern. The risk of contamination to the ocean and wildlife is there and it's serious."

He said his preference was to remove the contents of the tips, which a council-commissioned Tonkin Taylor report estimated could cost more than $10 million.

"My view at this stage would be unless we can guarantee complete reinforcement and containment of it, we should remove it. Because it is just going to be an ongoing problem for us and future generations," Cr Wolfe said.

"Originally a council motion I put up six years ago was for $20 million to deal with it. That seems a lot of money on its own but there's over $500 million in the state account for rehabilitation of tip sites."

The report also recommended sand re-nourishment of the dunes and warned a rock wall was "not a long-term management option as it is likely to fail in storm events and elevated water levels".

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