The following Frequently Asked Questions & Answers (FAQs) may assist in your understanding of the ongoing environmental investigation at Holden Elizabeth.
TCE and PCE are both non-flammable, man-made chemicals. They were widely used in Australia as a solvent to remove grease from metal parts in both domestic and industrial environments and as an ingredient in adhesives, paint removers, correction fluids and spot removers.
At the Holden Elizabeth site, TCE and PCE were used for cleaning car components and as an additive in the parts painting process. The chemicals have not been used at the Holden Elizabeth plant since the 1980s.
Historically, some businesses in the industrial areas neighbouring the Holden Elizabeth site are also expected to have used industrial solvents containing TCE and PCE.
For decades, manufacturing industry played a major role in Adelaide’s development and growth. As a result, it is not uncommon for some form of contamination to be present from the historical use of industrial chemicals on many of these current and former industrial sites, such as the Holden site and its neighbouring industrial areas.
In general terms, contamination varies greatly from site to site and the presence of TCE and PCE in groundwater in any given location can often be attributed to more than one industrial site and contributed to groundwater contamination in the area.
Holden’s environmental assessment has been thorough. Samples from 150 groundwater wells and more than 300 soil bores have been analysed. This is includes wells that have been installed in the surrounding area to gain a better understanding of the movement of groundwater.
The investigation to date has found:
- Potential historical chlorinated solvent (TCE and/or PCE) source areas and likely direction of its movement in groundwater. TCE and PCE have migrated from the ground into the groundwater at low concentrations. TCE and PCE are present in groundwater over a broader area, from Holden’s historic practices and industrial activities on nearby properties.
- Hexavalent chromium in two wells within a localised area in the central portion of site.
- Localised petroleum hydrocarbon impacts in two former underground storage tank areas, with low mobility in groundwater.
- A non-chlorinated solvent release, which is no longer occurring, into an underground concrete-lined trench which has subsequently leaked, causing localised groundwater impact.
- Per-and polyfluoroalkyl substances in groundwater (PFAS), low concentrations have been identified in two areas associated with historic fire training activities.
Ongoing groundwater monitoring will confirm the nature and extent of environmental impacts, noting site contamination for all substances found to date – other than TCE and PCE in groundwater – is localised (restricted to small areas and small number of locations).
Testing of site soil indicates that the majority of the soil at the site is free of contamination.
Testing both on the Holden site and at nearby residential properties has indicated no unacceptable health risk to residents or anyone working at the Holden site.
TCE and PCE are present in groundwater at low concentrations with no imminent risk identified.
Historical industrial activities on both the Holden site and nearby properties have resulted in co-mingled plumes of TCE and PCE in groundwater.
Co-mingled plumes of TCE and PCE in groundwater mean there is more than one industrial property identified as the source of the TCE and PCE.
TCE can potentially reach the indoor environment because of its ability to evaporate from contaminated groundwater and move through the soil as vapour. These vapours can potentially enter buildings through openings in the building foundation or basement walls.
In overall terms, the groundwater depth (18-20m), low concentrations of TCE and the nature of the local geology (predominantly clay soils) under the Holden Elizabeth site and its neighbouring industrial sites can slow down or restrict soil vapour movement, therefore reducing vapour migration to the surface compared with sites with shallower groundwater and/or coarser grained soils.
TCE vapour monitoring conducted in the residential area to the north of the Holden site has shown TCE vapour levels in building crawl spaces to be below the adopted screening guidelines, therefore no unacceptable risks from vapour inhalation were reported.
Ongoing groundwater monitoring will confirm the nature and extent of environmental impacts. As already stated, there are no imminent health risks identified. A final site-specific risk assessment report will be prepared once investigations are completed.
Holden voluntarily commissioned a site contamination audit in March 2012. Under Holden’s Voluntary Site Contamination Assessment Proposal (VSCAP) all site assessment is to be completed by November 2018.
As outlined by the EPA (SA), an audit is a system of actions that is intended to protect human health and the environment where site contamination exists, as well as provide rigour, independence and objectivity in the assessment, remediation and management of contamination.
The assessment is carried out by Holden’s environmental consultants and verified by an EPA-accredited auditor. This work will continue until the environmental assessment is considered to be complete. Once complete, a Site Contamination Audit Report is issued which sets out the findings, determinations and outcomes of the audit, alongside any required next steps.
Yes, historical industrial activities on nearby properties have resulted in co-mingled plumes of TCE/PCE in groundwater.
The environmental assessment process is expected to be completed by November 2018, with completion of the site contamination audit.
Holden is committed to ensuring that any legacy environmental issues arising from its vehicle assembly operations are managed appropriately and in accordance with regulatory obligations, both now and once manufacturing ceases.