A New Era, page-143

Disposal of toxic PASS is taken seriously these days

‘‘Residents will face the incessant movement of trucks carrying tunnel spoil. Much of the spoil will be toxic to be carried to licensed treatment facilities,’’ he said.
An SRLA spokeswoman said the vast majority of soil excavated would be safe to reuse for the project and on others.
An EPA Victoria spokesman said it would monitor compliance with its regulations for soil, plus pollution, gas emissions and other matters, throughout the entire project.

Soils ain't soils - that's why they had a seperate tender for PASS