LEGACY LANDFILL ASSESSMENT
WHAT IS A LEGACY LANDFILL?
A legacy landfill is a closed historical facility that was used for the disposal of waste and pre-dates current requirements for the management and mitigation of potential environmental and human health impacts. It is therefore unlikely to have environmental controls and monitoring systems in accordance with modern day best practice and it is not regulated by a State Government appointed Authority such the Environment Protection Authority (EPA).
There are literally hundreds of old landfills in Australia that may be leaking potentially toxic materials into soil and water and emitting greenhouse gases, such as methane gas, into the atmosphere.
Many of these sites are now community land such as sporting ovals and recreation parks. In most cases sensitive land uses e.g residential areas have been developed adjacent to the landfill post closure.
Chemicals and gases are released during the decomposition of buried waste. Contamination can also be caused by the buried waste itself, for example oils and greases, paints and contaminated soils. The resulting contaminants are characterised by the type of waste present and the method of disposal and containment. Contamination impacts occur when legacy waste sites are not identified and appropriately managed.
Gases and vapours
released from the decomposition of waste may present a human health risk
through inhalation, or an explosion risk through the build-up of gas.
Contamination of soil, surface
water and groundwater occur when contaminated water (leachate) drains out of a
landfill through infiltration or as run-off. Contamination may result in an
environmental risk to water quality through connected ecosystems. Contamination may also have potential to
cause a human health risk where there is direct contact.
Lack of, or inappropriate, management and monitoring of contamination associated with legacy waste disposal sites may present a risk to the surrounding environment through migration into soil, air, groundwater and surface waterbodies.
MANAGEMENT OF LEGACY LANDFILL
investigation, assessment and management of a legacy landfill is a 4- staged
process. The outcome of each stage will determine the initiation and content of
the subsequent stage.
The team at Direct Future Consulting have assisted local government councils in South Australia and New South Wales to identify the environmental impacts of legacy landfills, implement management and mitigation actions, facilitate community engagement and disclosure, and comply with state environment protection authorities.