The City of Rockingham, Western Australia, is moving to install new groundwater monitoring wells and conduct contamination testing at a former landfill on Ennis Avenue, raising questions about what decades of buried waste may be doing to one of Perth's most important water resources.
Rockingham sits about 40 kilometres south of Perth's CBD on the Swan Coastal Plain, where sandy soils and a shallow water table make groundwater both essential and vulnerable. Perth depends heavily on groundwater for drinking water, and contaminants can travel quickly through the region's permeable soils to reach the water table. A former municipal landfill in that environment, established under the looser environmental rules of the mid-to-late 20th century, is exactly the kind of legacy problem that regulators and councils are still working through decades later.
Older, unlined landfills are a particular concern because decomposing waste generates leachate, a mixture of heavy metals, organic compounds, and other pollutants that can seep downward into groundwater over many years. Western Australia's Contaminated Sites Act 2003 places clear obligations on landowners, typically local governments in the case of former municipal tips, to investigate and manage those risks on an ongoing basis.
Source: NationGraph.
The City has posted a tender seeking contractors to carry out the well installation and water sampling and analysis work at the Ennis Avenue site. The inclusion of well development alongside routine sampling suggests this may represent a new or expanded phase of investigation, possibly triggered by a regulatory review, new findings, or the expiry of a previous monitoring arrangement. The site's formal classification under the Department of Water and Environmental Regulation's contaminated sites database would shed more light on how serious the risk has been assessed to be, though that information was not included in the tender.
For the more than 140,000 people living in Rockingham, a rapidly growing outer-suburban area that has seen housing estates push into formerly semi-rural land over the past two decades, the monitoring matters. Residents near Ennis Avenue may not be fully aware that testing is underway or what results from previous rounds have shown. Long-term monitoring at former landfill sites can run for years or indefinitely, and potential remediation carries costs that stretch council budgets already under pressure from new infrastructure demands.
The City has not publicly released details on the timeline or scope of the testing program beyond what appears in the tender. Results from the sampling work, once completed, would typically be reported to DWER and may inform whether further action is required at the site.
