EPA Victoria has approved an Environment Management Plan (EMP) for Cleanaway’s Ravenhall landfill, as part of its application to receive tunnel boring machine (TBM) spoil from the West Gate Tunnel project.
Initial testing on the West Gate Tunnel project showed per- and polyfluoroalkyl substances, PFAS, could be expected when tunneling begins.
In its summary of Cleanaway’s EMP, the EPA states that Ravenhall landfill’s spoil containment cell will comprise a combination of a liner overlaid with additional protection and drainage layers, and a leachate collection system to avoid the potential for PFAS leaching into groundwater.
“EPA concludes that the proposed containment system will control and contain any contaminants leaching from the soil. Therefore, leached contaminants are unlikely to migrate into groundwater below the containment cell,” the summary reads.
Cleanaway must provide the EPA with further details for the design of the containment cell, leachate storage ponds, water treatment plant and capping design, which should include specific details on the construction quality assurance.
“There is a requirement for regular sampling of soils prior to being placed in the containment cell to ensure it meets the cell acceptance criteria,” the summary reads.
“EPA is also required to review auditor assessed final specific designs prior to and following the construction of the containment system at the site.”
The West Gate Tunnel project is expected to generate three million tonnes of waste soils from tunnel alignment over an 18-month period.
According to the EPA, landfills in Victoria cannot absorb an additional three million tonnes of waste soils within an 18-month period without exhausting existing capacity in the market.
The tunnel soil will also be wet and require a large area to aid dewatering prior to deposit in a cell – this space and infrastructure is not available at most landfills.
The EPA states that generic landfill designs will not be used for sites approved to take TBM soil.
“The designs are engineered, modelled and auditor approved based on everything that is known about PFAS, making them unique in Australia,” the EPA said.
New regulations under section 71 of the Environment Protection Act 1970 allow for the management and disposal of TBM spoil to protect human health and the environment.
“Sites approved under the regulations to receive this type of spoil are not areas engineered and licensed for landfilling of the various types of industrial and municipal waste, so spoil received and contained at these sites will not be subject to landfill levy,” the EPA said.
“The sites will appropriately treat, manage, segregate and contain the material so that it may be reused in future if a suitable use can be established.”
In addition to approving Cleanaway’s EMP, the EPA has accepted a modification to Maddingley Brown Coal’s plan in Bacchus Marsh.
The amendment to the EMP upgrades the proposed design of the containment facility to match acceptance criteria consistent with the other approved EMPs.
According to an EPA statment, it does not change the nature of the material to be contained, but adds additional controls.
EMPs for Maddingley Brown Coal and Hi Quality in Bulla were approved in September, as part of their applications to receive TBM spoil from the project.
EPA assessed the plans for potential environmental impacts, such as runoff, odour, and potential land, surface water and ground water risks. The approval of an EMP does not mark the final decision on where the spoil will be sent.
Under government regulations, the owner of a site bidding to receive TBM spoil must develop an EMP and comply with specific conditions, including constructing an appropriate containment system and managing spoil appropriately so risks are controlled.
“The health of the local community and the environment is our first priority and these EMPs will ensure they are protected,” EPA Regulatory Standards, Assessments and Permissioning Executive Director Tim Eaton said.
“Each of the EMPs has been rigorously reviewed and approved on the basis they meet strict conditions designed to protect human health and the environment. EPA will monitor any selected site closely to ensure it operates in accordance with its EMP.’’