West Gate Tunnel’s toxic soil woes sees another timeline blowout

A new blowout could mean the bulk of the tunnelling works on the West Gate Tunnel may not begin until 2022 — the year it was supposed to be complete.

Major digging on the West Gate Tunnel may not begin until the new year as delays remain in arranging a site to store toxic soil that has plagued the project.

The timeline blowout could mean the bulk of the tunnelling works at the centre of the $6.7bn project may not begin until 2022, the year it was contracted to open to motorists.

Digging on the project has effectively stalled since a dispute broke out about cost overruns related to dirt containing industrial chemical PFAS and asbestos.

But it is understood a breakthrough on the stalemate is close with the government, project proponent Transurban and the builders having positive discussions on a way out of their current hole.

CPB and John Holland had hoped to be digging by June and have asked three waste companies bidding to handle the PFAS-contaminated dirt to submit their best and final offer.

All three sites at Bacchus Marsh, Bulla and Ravenhall have environmental and planning approval to handle the soil but are waiting to find out who will be awarded contracts.

Digging on the project has effectively stalled since a dispute broke out about cost overruns related to dirt containing industrial chemical PFAS and asbestos. Picture : Ian Currie

The Herald Sun understands that building a safe and secure site to store contaminated soil would take four to six months, with sources saying they have been told it is now unlikely major tunnelling would be able to begin until the new year.

Less construction work will be possible during the wetter winter months, while a Supreme Court challenge from three local councils is also yet to be resolved.

A government spokeswoman said thousands of workers were making progress on other parts of the project.

“The tunnel boring machines are assembled but can’t be switched on until Transurban and its builders choose a site for soil disposal,” she said.

Government documents obtained under Freedom of Information show that if approval is granted for one site, named Maddingley Brown Coal, there would be “earth walls” constructed around the site to buffer neighbouring residents and businesses.

There would also be a “protective liner around areas where any spoil containing PFAS is stored”.

Water run-off from the soil would be collected in an existing pond system that would be sealed and lined to protect the groundwater table and treated to remove PFAS.

These measures would need to be built, tested and approved for use by environmental regulators.

Documents also show local concerns were raised last year about trucks running 24/7 to the MBC site for “approximately 2 years” if that was the preferred destination for toxic soil.

At peak tunnelling there would be 400 trucks a day.

The briefings maintain there would be “minimal amenity impacts to locals” from expanding the MBC site, including “no odour, litter or dust, and minimal noise”.