How much spoil will the West Gate Tunnel Project generate?

About 3 million tonnes (1.5 million m³) over an 18-month period.

What are the risks of tunnel boring machine (TBM) spoil?

Tunnel boring machine (TBM) spoil can include contaminants, including PFAS. However, TBM spoil comes from depths of about 20 to 40 metres below ground level, where contamination levels tend to be low.

Regardless of depth or source, EPA closely monitors compliance with regulations and conditions to reduce the already low risk to the health of the community and the environment.

What happens after the spoil comes out of the tunnel?

The spoil will emerge from the TBMs on a conveyer belt into a large shed at the site in Yarraville.

The spoil will then be transported to the Bulla Spoil Facility and depending on the test results, the spoil will either be available for reuse, deposited into the containment cell at the Bulla Spoil Facility or disposed at a licensed facility.

While waiting for the test results the spoil will be laid out in bays and dewatered. Testing of the leachate (i.e., liquid that drains from the waste) will determine whether treatment of the water component is needed.

Why can’t tunnel boring spoil be disposed of at existing landfills?

While some landfills are already licensed to receive this kind of material, the volume and type need to be carefully transported and stored, in line with EPA’s strict conditions. Therefore, spoil is placed in a fit-for-purpose facility that will store it appropriately and minimise potential strain on existing landfill capacity.

Wherever possible, re-use or recycling are the preferred approaches to managing waste. EPA supports programs across the State to facilitate this shared responsibility, however, landfills in Victoria currently accept between 4 and 5 million tonnes of total waste per year.

How much soil currently goes to landfill in Victoria?

Landfills in metropolitan Melbourne accept about 650,000 tonnes of waste soil annually.

What is PFAS?

PFAS (per-and polyfluorinated alkyl substances) are a group of manufactured chemicals used in many industrial and household products. There are low background levels of PFAS in the environment across Victoria and around Australia.

Most of us are exposed to very low levels of PFAS in everyday life, from common items including some non-stick cooking equipment, furniture and carpets treated for stain resistance, clothing, fast food packaging or packaged food containers.

More information about PFAS and how EPA manages it is available on our website.

What are the effects of PFAS on the community and wildlife?

PFAS is persistent, meaning it doesn’t break down for a long time. PFAS also bioaccumulates and is soluble, which is most likely to impact aquatic systems.

Should PFAS enter sensitive aquatic ecosystems, it can build up in the food chain.

More information about PFAS and how EPA manages it is available on our website.

What measures are in place to prevent dust from the sites blowing onto surrounding areas?

The spoil received from the West Gate Tunnel Project will initially be wet, street sweepers and wheels wash facilites will also be in operation to ensure any dust generation from the haul roads is kept to a minimum. Air quality monitoring will also be undertaken to assess that dust control methods are working and are effective.

Is EPA studying the area around the landfill to see what the impacts and effects are on the community health?

We have ongoing air, dust, groundwater monitoring around these sites and have numerous ongoing projects looking at PFAS and other emerging contaminants, pharmaceuticals, and microplastics in biosolids. 

What controls will be in place to manage spoil movements?

The Bulla Spoil Facility must comply with an EPA-approved Environment Management Plan (EMP). The plan itself requires the duty holder to comply with strict conditions designed to protect human health and the environment, including that the processing area for the spoil is on an impervious surface.

If the recommendation is to take practical steps to minimize exposure to PFAS, why is it being stored near homes?

The approved EMP has multiple layers of management around the possible community and environmental impacts, both in the design and management of the site. These include the engineered design of the holding bays and long-term containment cell, through to the management plans to ensure dust is minimised.

The site has been engineered to accommodate a PFAS concentration that is 10 times greater that the amount expected in the spoil from the tunnel boring machine. 

What engagement occurred on the regulations?

The Department of Environment, Land, Water and Planning (DELWP) consulted EPA and other parts of government to ensure potential impacts to human health, planning and transport were considered.

For transparency the  approved EMP has been published on EPA's website, consistent with the requirements of the regulations.

What are the ongoing testing requirements?

The required testing regime is extensive and will continue beyond the operational life of the approved facility. As testing reveals more information about actual PFAS levels, testing can be adjusted with agreement from EPA. The testing regime is set out in the EMP and it is a legal requirement that it is delivered.

Results will be provided to EPA and an independent auditor for oversight. EPA will also make testing results public.

What is the testing process for the soil from West Gate Tunnel?

Testing happens in multiple stages. Early testing was conducted as part of site investigation works as part of the Environment Effects Statement (EES). This information indicates potential areas of low-level contamination. Some of that information is available to the public through the EES process and published online.

When soil comes out of the tunnel, samples are collected and tested for levels of PFAS and other potential contaminant depending on its location along the tunnel alignment.

Once the spoil arrives at the Bulla Spoil Facility there are a series of bays to segregate the spoil. Each of those bays holds approximately 3000 cubic meters. The soil will be held in the bays while waiting for sampling results. The sampling results determine whether to soil can be contained on-site, disposed to landfill, or require treatment.

Has other contaminated soil on the project already been classified for removal by EPA?

EPA has processed multiple applications for soil disposal from various stages of the project. These applications cover a wide range of contaminants including PFAS. The permissions granted under the Regulations have authorised disposal at suitably licensed facilities.

What other chemicals or contaminants may be in the spoil?

Soil sampling to date has shown that there may be a broad range of potential contaminants at multiple points along the tunnel alignment.

The containment cell at the Bulla Spoil Facilityis just for the PFAS and it can only be used for storing spoil with leachable concentrations of PFOS+PFHxS below 7 ug/L (0.000007 g/L) and PFOA below 56 ug/L (0.000056 g/L).

The site has been engineered to accommodate concentrations that are 10 times greater that the amount expected in the spoil from the tunnel boring machine.

Will testing results be made available to the public?

Yes. The project partners are obligated to provide data to EPA within 21 days of each test. EPA will make these results available on its website.

Will EPA do any independent testing?

Yes. EPA is authorised to attend and conduct testing at any time. The frequency will change throughout the project and depend on the observations made by the officers during the inspections. Initially, while the process of soil management is being established on-site EPA will have a greater presence. Then depending on the compliance with the EMP, these may decrease. EPA visits to the site are unannounced and randomly timed to ensure officers obverse the true state of the site during the inspection.

When will the first deliveries of soil arrive on site?

The first trucks arrived at the Bulla Spoil Facility on 2 March 2022.

What routes are trucks going to take?

Truck movement routes are specified as a result of the 2016-17  Environmental Effect Statement . Planning limitations are applied to the usage of certain roads that must be avoided during the transport of material from the WGT. The Department of Transport is working with the project to ensure traffic is managed appropriately.

What are the days and hours of operation?

The Environment Management Plan allows for 24-hour operation.

Tunneling operations are required to occur 24 hours/day as the tunnel boring machines cannot stop for long periods once started.

For how long will truck deliveries occur?

The tunnel is expected to take approximately 18 months to construct. Production of spoil ramps up slowly to peak production for a few months and then decreases towards completion of the tunnel.

How many trucks of soil will go through Yarraville and Footscray each day?

Information is based on modeling done by the Waste Gate Tunnel project team. EPA has been advised that approximately 400 trucks per day are expected to be on the roads at peak of production for the duration of two to four months. At the start and as the project progresses towards the end the frequency of truck movement on the roads will be it will be much less.

Will EPA monitor the transportation of the waste so that it doesn’t create a hazardous spill on our roads?

EPA has required the waste generator to transport the soil in sealed trucks which will stop leakage of the wet material and dust. All truck movements will be recorded and records reconciled to ensure all waste goes to the correct location.

In the unexpected event of a crash leading to the loss of containment of some spoil, standard practices will be employed to prevent waste soils entering the stormwater system. At the levels expected, there is no risk to human health and the material can be safely handled by personnel.

Truck routes and operating hours are a matter for planning controls and EPA does not regulate which roads will be used.

How will leachate be prevented from entering waterways, wetlands and groundwater?

The Bulla Spoil Facility  has been designed specifically to manage the risks of low level PFAS containing soils. The design includes features to enable any water containing PFAS to be collected and treated prior to the soil being deposited in a specially designed containment cell. Cell design features include multiple layers of liner to ensure any residual water can be collected and removed rather than permeating the rock beneath the cell.

How are these design elements different to a normal landfill?

There are several landfill types in Victoria including municipal waste landfills and landfills for solid inert waste such as soils.

EPA defines the engineering requirements for each type. Each landfill cell is designed to meet the best practice environment management requirements and an EPA appointed auditor approves the design.

The Bulla Spoils Facility was  designed to protect the environment from PFAS specifically. The designs are engineered, modelled and auditor approved based on everything that is known about PFAS, making them unique in Australia.

The site has been engineered to accommodate a PFAS concentration that is 10 times greater that the amount expected in the spoil from the tunnel boring machine.