Council will soon begin Landfill Capping works at the Porepunkah Transfer Station.
These works will include the replacement of the existing clay capping with a geosynthetic clay liner over old landfill waste to meet the EPA’s requirements of Best Practice Environmental Management guidelines.
In addition to reaching compliance with the EPA requirements this will contribute to reducing the GHG emissions that result from residual organic waste that was buried when the Porepunkah Transfer Station was once a landfill site.
To support these crucial construction works there will be changed opening hours and accepted materials at the Porepunkah Transfer Station from Monday, 12 December 2022 to late 2023.
From Monday, 12 December 2022, the following materials will not be accepted:
- Cleanfill
- Green Waste
- Drummuster Containers
- Carbodies
From Tuesday, 10 January to completion of the project in Spring 2023 Porepunkah Transfer Station will be closed during weekdays.
Opening hours – Saturday and Sunday - 10am-2pm
Closed – Monday – Friday.
Council will keep residents informed of any further changes as the project progresses.
Project information
The Porepunkah Transfer Station Landfill Rehabilitation Capping Project will see the construction of an earth cap comprising of a subgrade, geosynthetic clay liner, confined and topsoil layers.
These are crucial construction works to ensure the residual landfill is appropriately contained and isolated from the outside environment, specifically water and atmosphere.
The works involve placing a barrier over filled landfill to minimise percolation of water into the existing landfill waste cells.
Caps do not destroy or remove contaminants. Instead, they isolate them and keep them in place to avoid the spread of contamination.
Caps prevent people and wildlife from coming in contact with contaminants.
Currently Council’s residual landfills across the Shire emit approximately 500 tonnes of greenhouse gas emissions. The capping works will also help to reduce these emissions, which is a key action for Council to reach net zero by 2023.
Green waste is currently one of the items that Council is unable to accept at the Porepunkah Transfer Station. This is because there is no other location within the footprint of the transfer station that would meet the Environment Protection Authority's required standards of green waste storage.
How Does It Work?
A cap isolates and prevents the spread of contamination in several ways. For example, it can:
- Stop rain from seeping through the material and carrying contaminants to the groundwater.
- Keep storm water runoff from carrying contaminated material offsite or into lakes and streams.
- Prevent wind from blowing contaminated material offsite.
- Control releases of gas from wastes containing or producing “volatile” chemicals (those that evaporate).
- Keep people and wildlife from coming into contact with the hazardous material and tracking contaminants offsite.
The subgrade is a 300mm layer and is required to provide a solid base over the waste to lay the geosynthetic clay liner (GCL).
The GCL is a woven fabric material sandwich with sodium bentonite clay in the middle which acts like a geomembrane, sealing the landfill and preventing water from entering the landfill.
The GCL consist of panels 45m long, 4.5m wide and 8mm thick. These panels are placed over the entire waste cell.
The confining layer is 300mm clay layer and acts as barrier to protect the GCL and prevent the seepage of water into the landfill.
These works aim to prevent leachate from the landfill entering natural water sources in the area.
The Environmental Protection Authority (EPA) provide strict guidelines on the construction of landfill caps.