The West Gate Tunnel is a State Significant road project.
 

To build it, large amounts of soil will be dug up, and a facility is needed to receive and safely manage the soil.

Maddingley Brown Coal is proposing to develop Western Soil Treatment, a facility to manage the soil - known as spoil - some of which is expected to be contaminated with low levels of PFAS, a group of man-made chemicals.

The EPA has approved an Environmental Management Plan for the facility.

 

The project also needs planning approval, and a contract from the West Gate Tunnel Project's builders before it can proceed. 

Western Soil Treatment will not receive any West Gate Tunnel Project spoil until the project’s builders award a contract.

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The Proposal

Western Soil Treatment is situated within a State Significant Waste hub that includes a licensed Category C landfill.

Western Soil Treatment comprises two main areas.

The first is where covered, and sealed trucks would unload the soil into designated bays. The EPA has confirmed that the expected level of contamination is low (up to 0.7 micrograms per litre).

Trucks would be tracked by GPS from the tunnel site to make sure each load is unloaded in the right bay.

The soil will arrive at the site wet, like thick mud. It will be placed in specially constructed storage bays that are lined with layers of compacted clay, cement, lime and other materials to ensure they are watertight.

A sample from each batch of soil will be sent to a laboratory for testing on a daily basis. This testing will be conducted in line with national policies for managing PFAS and EPA regulations and requirements.

The soil will be held in the storage bays for a maximum of 21 days before being moved into the second area, a lined containment cell that is engineered to the highest safety standards.

The design of the containment cells has been upgraded and approved by the EPA, effectively doubling the strength of the liner system.

 

The level of contamination expected in the soil remains the same, but the  strengthened containment cell adds an even greater layer of protection against already very low risks.

Water from the facility will be drained into a purpose-built pond. A treatment plant will remove traces if PFAS through a state-of-the-art filtration process, leaving clean water that meets drinking water standards.

For more information, download the FAQs, a Fact Sheet and a summary of the EPA assessment of the proposal.

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A facility to safely manage soil from the West Gate Tunnel Project.

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Timeline
MBC commences discussions about project

November 2019

Stakeholder and community engagement

February and March 2020

Planning Scheme Amendment submitted

May 2020

Environmental Management Plan approved

August 2020

Successful site selected

TBC

We heard what you said

The proposal has been refined over eight months of consultation with stakeholders, regulators and agencies.

In February and March 2020, MBC undertook engagement on its proposal. This included community information sessions, a series of stakeholder briefings and two community pop-ups. 

 

Feedback from stakeholders has helped shape changes to the proposal to further reduce the already very low risks. The facility now includes:

  • A wastewater treatment plant to remove traces of PFAS from wastewater, leaving clean water that meets drinking water standards.

  • An upgraded containment cell with stronger liners – doubling the strength of the liner system using a landfill-standard double composite liner using a state-of-the-art membrane.

  • Strengthened storage bays and the construction of a prototype, which is proven to stop wastewater reaching groundwater.

All of these measures form part of an approved Environmental Management Plan, which will be overseen by the EPA in line with regulations and requires strict monitoring, compliance and auditing by an independent expert.

 

To see how stakeholders' feedback helped shape the proposal, click here.

To view the Environmental Management Plan, click here.

Water Treatment

A state-of-the-art wastewater facility will treat water to remove traces of PFAS.

Water from the wet spoil, storage bays and containment cell will drain into a large wastewater pond.

 

There, the wastewater will be passed through a filtration system that uses carbon filters

 

Any PFAS in the water will bond to the carbon filters. Full filters will be taken to a licensed facility for disposal.

 

This process leaves behind clean water that meets drinking water standards. This water will be used for onsite for dust suppression, forming a closed-loop wastewater treatment cycle.

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Compliance

Western Soil Treatment will be operated in line with strict EPA regulations.

The facility will be built and operated in line with the approved Environmental Management Plan.

The Environment Management Plan - which is available online here - details how the facility will receive, handle, analyse and dispose of the soil, including the removal of traces of PFAS chemicals from wastewater.

The Environmental Management Plan covers all aspects of the facility, including soil management and handling, sampling and analysis, wastewater treatment and disposal.

It also includes requirements for regular checks by an EPA appointed independent auditor.

For more information on the EPA’s regulation of the facility, visit the EPA West Gate Tunnel Community page.

 
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Next steps

Western Soil Treatment will not receive any West Gate Tunnel spoil until all environmental and planning approvals have been granted and a contract is awarded at the end of the tender process.

Check back for regular updates, or contact us using the form below.

Contact

For more information, please contact us via the form below.

We'll respond within 48 hours.

 
 

© 2020 by Western Soil Treatment Pty Ltd