Extensive studies have been conducted to assess the potential impact of this contamination to the environment and future workers on the site. The nearby Helena River was found to be at the most risk. Studies of the movement of the groundwater suggested that the contaminants could reach the river.
WA’s first Permeable Reactive Barriers (PRBs) were installed in 2010 to prevent this flow of groundwater contaminants into the Helena River. This system works by breaking down the chemicals, allowing only treated groundwater to flow out of the system.
Studies since the installation of the PRB have shown the system has successfully halted the flow of the contaminants, preventing damage to the Helena River.
The next step in managing the site is to address the contamination at the source.
Work was completed in early 2019 to remove the concrete slabs and services from the Bulbey Street site, followed by remediation of shallow soils where required. Affected soils have been excavated and transported for disposal at an appropriate landfill, approved by DWER.
A Site Management Plan will be in place throughout the work and dust monitoring will be undertaken during the excavation work.
The site investigations also identified a second area of groundwater contamination near Stanley Street. This area is undergoing ‘in-situ bioremediation’, which involves injecting emulsified vegetable oil and specifically developed non-toxic bacteria into the soil to breakdown the contaminants.
Throughout this process, extensive above- and below ground monitoring will be undertaken to ensure the safety of workers and the environment.
All remediation related activities are reviewed and approved by DWER and an accredited Contaminated Sites Auditor.
If you have any queries, please contact Doug Stirling from DevelopmentWA on 9482 7499.