The issue highlights the complex challenges of managing vast amounts of rock and soil being dug up to build up to five tunnels over the next decade.
These projects will put a major strain on the state’s landfills, engineering firm GHD warned in an analysis of the impact of the North East Link, Metro Tunnel, West Gate Tunnel and Bonbeach and Edithvale level crossing removals.
There is currently not enough space in the state’s tips to store the most hazardous soil, known as Category A and B, the firm warned in a report for the North East Link’s environmental effects statement.
Only one landfill operator in Lyndhurst is licensed to take Category B soil and no landfill can take the most toxic type, Category A.
“The estimated volume of Category B waste spoil across the four projects could exceed the current total existing landfill capacity for this type of waste by 50 per cent,” the firm warned.
Craig Barker, who is an EPA auditor and was the government-appointed contamination expert for the North East Link, also warned that the state’s major projects would put “cumulative stress” on the waste industry.
Mr Barker questioned why thorough planning was not being done for the management of waste being generated by the $15.8 billion North East Link.
“Why has there not been the establishment of a formal technical working group for this project given that it is likely to be a dominant contributor to future volumes, where clearly, this will have some impact to the contaminated land industry within Victoria?”
Landfill operators claim they will have enough room to bury the piles of rubble and dirt, but GHD said this was not guaranteed and called for contingency plans.
But toxic material expert Andrew Helps said more testing of contaminated material was needed to see if it could be reused rather than sent to landfill.
“The thing with landfills is they’re one use only,” he said.
There would be an “enormous deficit” in future landfill capacity based on the amount of toxic material to be extracted from the infrastructure projects, he said.
The West Gate Tunnel’s contractors and Transurban are understood to be in discussions with landfill operators Hi-Quality Group in Bulla and Maddingley Brown Coal in Bacchus Marsh to find a place to dump the project’s spoil, with a contract expected to be signed within a fortnight.
Transport Infrastructure Minister Jacinta Allan said contractors on the state’s major projects were looking for the best ways to reuse rock and soil.
“There are strict rules in place to ensure contaminated soil is dealt with safely – so we can get on with delivering these vital projects.”
A West Gate Tunnel spokeswoman said all parties were working with the EPA and Worksafe to manage the excavated material.
“We’re building the West Gate Tunnel to finally give Melbourne an alternative to the West Gate Bridge and works are carefully planned and managed to minimise disruption as much as possible.”
The North East Link’s shortlisted contractors would be asked to draw up a spoil management plan and the project’s chief executive Duncan Elliott said the project would repurpose its soil.
“Through sustainability targets, we’re encouraging our three shortlisted bidders to look at innovative ways to reuse the spoil on site for things like landscaping and noise mounds, reducing the amount of material that needs to be removed.”
Maddingley Brown Coal and Hi-Quality could not be reached.
Timna Jacks is Transport Reporter at The Age
Benjamin is a state political reporter