The design and management of landfills across Australia is highly variable. Although landfill design has improved over time, many historical landfills still in operation have limited measures in place to stop contaminants from migrating off site. Two of the key pathways for contaminant transport are via leachate to groundwater and overland flow via surface run-off.
This study used a multiple lines of evidence approach to investigate whether a landfill which has operated since the 1960s has impacted an adjacent agricultural property. This investigation was undertaken in response to concerns raised by the resident to their local environmental regulator. The concerns were related to potential adverse impacts from the landfill on their property.
Since commencing operation, the landfill has received a wide variety of waste types, including, municipal solid waste, commercial/industrial waste, construction/demolition waste, agricultural waste, and special waste (e.g. animal carcasses). The landfill has limited environmental controls in place for containing and managing landfill leachates and surface water runoff. A range of samples were collected from the landfill and resident’s property including soils, sediments, surface waters, spring waters and groundwater. The samples were analysed for contaminants indicative of the landfill impacts.
Due to the complexity of the site, one of the key objectives of the study was to determine connectivity between different water sources. This information was used to develop a conceptual site model highlighting the potential fate and transport of the contaminants from the landfill. The data were used to determine if contaminants were migrating from the landfill onto the resident’s property and then to assess the significance of the impact. The process and findings of this investigation will be presented as well as the conceptual site model developed from the results and conclusions of the work.