New Guidance on Landfills - Draft Landfill BPEM

The list of topics have been developed based on main themes of discussion during consultation workshops. The topics have been added to prompt further feedback on these issues. 

To protect other land uses from the potential effect of a failure of landfill design or management (such as migration of landfill gas, offensive odours, noise, litter and dust), an appropriate buffer distance must be maintained between the landfill and sensitive land uses. This is not an alternative to providing appropriate management practices, but provides added protection for the community.

The existing requirement of a 500 m buffer for amenity has been expanded to refer to health and safety risks.
The draft Landfill BPEM also proposes an additional requirement of a 500 m buffer for a closed landfill (one that has ceased receiving waste) for up to 30 years post-closure. This takes into account ongoing risks post-closure, such as landfill gas migration. These buffers provide a trigger for an assessment of risk rather than an exclusion zone.

Methane and carbon dioxide in landfill gas can cause health, safety, amenity and environmental risks. If not appropriately managed, landfill gas can be emitted from a site by a number of pathways.
The draft Landfill BPEM proposes specific ‘action levels’ for landfill gas to provide a clear trigger for action in relation to landfill gas for open and closed landfill sites.

If monitored levels exceed the landfill gas action levels, action must be taken to ensure that any risk associated with the landfill gas is mitigated. This could be an adjustment to the gas extraction system or a more detailed review of the capping and extraction system.

The draft Landfill BPEM also sets out requirements for the design of landfill cells. The overall cell design is critical for landfill gas management. The gas management system must be installed progressively.

The final cap on a landfill cell must minimise the amount of water that seeps through, provide a long-term, stable barrier between the waste and the environment, and prevent uncontrolled escape of landfill gas.
Clay caps have been used throughout Victoria for decades with good performance. The draft Landfill BPEM has incorporated technical specifications for phytocaps. These provide an alternative to clay capping that is particularly suitable for Australian conditions. They use the water removal capability of plants (evapotranspiration) and water storage capacity of the soils in the phytocap to reduce the rate of infiltration into the landfill .
Monitoring and maintenance of the soil and plants is a key part of the design process for phytocaps, which must be demonstrated to provide similar performance to a traditional clay cap.

The draft Landfill BPEM provides technical specification and operational management requirements for enhanced degradation landfills (EDLs). EDL’s are designed to maximise the rate of degradation of biodegradable wastes making it easier to use the landfill gas for power generation. The production of landfill gas is accelerated, resulting in increased gas capture during operation and immediately after closure of the landfill cell, but a reduced period of gas production. Therefore, the long term risk associated with landfill gas is reduced.

The siting of an EDL is particularly important and the draft Landfill BPEM proposes that EPA will only approve an EDL that meets all the siting requirements, such as separation from groundwater and appropriate buffer distances.

The draft Landfill BPEM has updated the design and construction requirements for landfills. This includes cell size, liner systems, installation and construction. The details of the liner system, specifications and construction quality have been developed for EPA by Monash University with input from world experts on geomembranes, geosynthetic clay and geotextiles.

The draft Landfill BPEM provides landfill operators and other organisations with guidance on undertaking effective community engagement. It outlines the benefits of planning and effectively undertaking engagement and outlines the types of approaches that could be used.