11 April 2023
The West Gate Tunnel Project is a vital project for Victoria. It will provide an alternative to the West Gate Bridge, take thousands of trucks off residential streets in the inner west and create 6000 jobs.
To build the West Gate Tunnel approximately 1.5 million cubic meters of soil will need to be removed.
Digging up this amount of soil is a 24/7 operation at our tunnelling hub in Yarraville. Testing shows the levels of PFAS expected to be found during tunnel boring are low and at safe levels for the community and the environment. Groundwater testing along the tunnel alignment shows PFAS levels of between zero and 0.7 micrograms per litre or less, which is between detectable limits and much less than water that is safe to swim in.
Where does the soil go?
Soil from tunnelling is sent to Hi-Quality’s Bulla Spoil Processing Facility that manages and disposes of soil excavated by the West Gate Tunnel Project.
Hi Quality’s facility has been designed to effectively manage all tunnel soil with low levels of PFAS. The EPA has rigorously assessed the site’s environmental management plans to ensure all environmental risks are addressed. This includes groundwater and surface water quality, air quality, and noise.
How tunnel soil gets taken out of the ground
As our Tunnel Boring Machines (TBMs) dig underground, excavated soil is moved via a covered conveyor system that crosses high above Somerville Road to our purpose-built shed located on Whitehall Street, Yarraville.
It is then placed in storage areas before excavators load it into covered trucks for safe and secure transport to a disposal facility.
All relevant EPA Victoria and WorkSafe Victoria requirements are met every step of the way to protect the community and workers from the moment the soil is dug up to when it’s transported and disposed of appropriately.
Safely managing any soil
Extensive testing has shown that the levels of PFAS in the groundwater from soil extracted by the tunnel boring machines is expected to be low and at safe levels for the community and the environment.
Testing indicates levels of PFAS between zero and 0.7 micrograms per litre – which is between detectable limits and water that is safe to swim in.
Despite these findings, the Victorian Government has a strong track record of taking a conservative, safety focused approach to the management of PFAS. When managing soil, our first priority is to make sure protections are in place for the community and workers in line with EPA and WorkSafe requirements.
Safely transporting soil
The trucks that take tunnel soil away from West Gate Tunnel Project worksites are covered and sealed so there is no dust or soil dropped on the road.
Other safety measures include hosing down the truck and its wheels before it leaves site, and fully loading the truck in an enclosed shed.
Drivers are fully trained and GPS technology in the trucks allows monitoring to ensure truck routes are adhered to.
All trucks must meet EPA requirements, are fully assessed for roadworthiness and compliance with noise and emission limits and follow approved truck routes to get to the disposal site.