Theme: 15. Suggest a New Topic Area

Formatted Title:

From Reactive to Proactive: A Decade of Managing Orphaned Site Contamination in South Australia

Background/Objectives:

Aquifer conditions in metropolitan Adelaide, South Australia, are conducive to the migration of legacy chlorinated groundwater plumes over large distances. Over decades these plumes have moved away from the industrial source areas towards residential settings. In 2013 and 2014 the ad hoc management of orphaned chlorinated hydrocarbon contamination, associated with historical automotive manufacturing activities in the metropolitan suburb of Clovelly Park, attracted considerable public attention and became a controversial political issue. The reactive response of the government resulted in sub-optimal stakeholder engagement and uncapped spending to assess orphaned site contamination. In 2015 the Board of the South Australian Environment Protection Authority (SA EPA) undertook a review into the Clovelly Park case to identify opportunities for improvement. The review recommendations were actioned in 2016 when the South Australian state government allocated funding to improve communication, assessment and management of public health risks posed by orphaned site contamination in South Australia. Over the past decade orphaned site contamination management in South Australia has evolved to the current structured, proactive, whole of government and community supported approach.

Approach/Activities:

The SA EPA has built capability in community and stakeholder engagement, procurement, project management and strategic program management with the establishment of a dedicated Orphaned Site Contamination Team in 2016. An annual allocation of $2M AUD covers costs associated with the newly created roles and expenditure on commissioning independent assessments of orphaned site contamination. Initially the program was run as a 4-year trial administered by the SA EPA under an internally developed Exceptional Circumstances Policy for Management of Orphaned Site Contamination that presents an unmanaged public health risk (EC Policy, 2016). This approach allowed government to monitor expenditure and the community response to see if the program was meeting expectations. It also enabled affected government stakeholders to build trust in the process led by the SA EPA.

An internal review completed in 2022 led to standardisation of key processes and the development of the Orphaned Site Contamination Management Framework (the OSCM Framework, 2022). Based on the demonstrated ability for the SA EPA to work with internal and external stakeholders in sensitively communicating and managing orphaned site contamination the funding was made on-going with the EC Policy updated in 2022 to reflect learnings and process improvements from the initial trial period.

Results/Lessons Learned:

Since 2016 the SA EPA has established 10 assessment areas covering a total area of over 7 km² and capturing more than 6000 properties.

Assessment and subsequently remediation is prioritized according to the OSCM Framework with contamination potentially presenting the greatest public health risk addressed first. Most of the program expenditure has related to assessing and managing the vapor intrusion risks associated with chlorinated hydrocarbon contamination. Timeframes for action, developed in consultation with SA Health, are incorporated into the framework and are used to manage stakeholder expectations. Assessment is staged with groundwater and soil vapor investigations conducted in public spaces to determine the extent and magnitude of contamination and to identify key data gaps which inform subsequent stages and priority for investigation. To date, the South Australian government has retrofitted 20 vapor mitigation systems to residential properties where TCE concentrations indoors were confirmed to be above levels considered safe.

While the SA EPA continues to explore alternative approaches to better manage vapor intrusion risk at the property level and at a broader land-use planning level, it has the first and most well-developed strategic orphaned site contamination management program implemented in Australia and serves as a benchmark for other jurisdictions nationally.

Rebecca Hughes

Affiliation

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(Group 1, Poster Board #128) From Reactive to Proactive: A Decade of Managing Orphaned Site Contamination in South Australia