Brownfield Redevelopment - Landfill, Western Australia

RPS contaminated land specialists from Western Australia have been working for nearly two decades to monitor and remediate a former landfill zone for safe redevelopment.

Solution

Over 20 years of work at the site, our environmental teams have completed a wide range of studies and monitoring programs focused on landfill gases, soil and groundwater contamination.

With our work revealing that some of the fill material used to cap the site was contaminated with asbestos containing materials (ACM), we developed a comprehensive remediation and validation program that included the mechanical screening of 50,000 m3 of soil and daily monitoring for airborne asbestos fibres.

Remedial works were undertaken over a 21-week period, and the innovative method our team devised for remediation resulted in the reuse of approximately 95% of screened soils on site, with the remaining material encapsulated below a warning barrier. As a result, no fill needed to be removed for disposal elsewhere.

Remediation innovation helps to return 'waste land' to the community

Due to the former use of the site for waste disposal, the site has been classified as ‘contaminated – remediation required’ since the municipal landfill’s closure in 1990. Our team’s work has significantly improved the site’s condition and it has subsequently been redeveloped as sports playing fields and pitches.

A comprehensive program of monitoring was developed to characterise the groundwater and landfill gas prior to development. Additional monitoring was completed for two years post-development to demonstrate that the development of the site had not impacted groundwater or landfill gas. A long-term Site Management Plan was then developed to permit safe operation of the site into the future.

In 2020 the Western Australian Department of Water and Environmental Regulation (DWER) reclassified the site as ‘remediated for restricted use’.