Licences and approvals

Landfill gas around Melbourne Regional Landfill

Why is it a concern?

Landfill gas is a mixture of different types of gases produced from the breakdown of waste in landfills. It is odorous and in certain conditions, can potentially be explosive when mixed with air. It also contains greenhouse gases such as methane and carbon dioxide.

Landfill gas can potentially be released into the air. If landfill gas escapes from containment areas, such as gas wells, it can move through rocks and soils around the landfill. For these reasons, landfill gas requires careful management and monitoring.

How was it assessed?

A model of the landfill and its waste management systems was used to assess the landfill gas risk. The model considered things such as: the size of the site and the local landforms; cell liners; and the type of waste managed at the site. The model then put the landfill site in context of the surrounding geology, hydrology (surface and groundwater), air quality and human interactions. The model also predicted the potential for landfill gas to:

  • escape the containment methods proposed in the application
  • migrate through soil and rock to areas outside of the landfill.

Overall it was concluded that the landfill gas management and monitoring in the Works Approval application is best-practice and should be reinforced by EPA licence conditions.

How will it be managed?

Landfill Operations has to take all steps, where practical, to meet the emission levels for the various landfill gases set out in the Landfill BPEM. To do this, Landfill Operations must:

  • install gas wells at regular intervals that are connected to the gas extraction system specified in the Works Approval
  • use appropriate capping methods to make it easier to collect and control the landfill gas
  • extend the existing landfill gas monitoring system at the landfill.

Page last updated on 24 Mar 2017