Ministerial Statement

Site Contamination, Thebarton

The Hon. I.K. HUNTER (Minister for Sustainability, Environment and Conservation, Minister for Water and the River Murray, Minister for Climate Change) (14:28): I seek leave to make a ministerial statement on the subject of TCE investigation at Thebarton.

Leave granted.

The Hon. I.K. HUNTER: Earlier this year, the Environment Protection Authority commenced assessment works on the Thebarton area to assess the extent of groundwater contamination and to determine if there was soil vapour intrusion. Residents were informed of this work prior to its taking place. The final report from the site contamination consultant is yet to be provided, but as part of their contract the consultant is required to inform the EPA of any soil vapour data that is potentially concerning.

I am advised that this is what occurred on 7 September when the EPA was provided data showing high concentrations of trichloroethene (TCE) vapour in soil in a small portion of the assessment area. The contaminant TCE is a volatile organic chemical that was historically used in industrial and commercial activities. Over a period of time, TCE can change to a gas form and then migrate upwards through the soil as vapour.

Upon receipt of the preliminary data, the EPA identified a total of 17 property titles with potential vapour intrusion risks associated with the high soil vapour results. Subsequently, on 8 and 9 September, the EPA contacted the impacted property owners and residents to seek permission to undertake subfloor and indoor air testing. Eight properties initially agreed to have indoor testing conducted and a further six have now provided permission for this to occur.

The EPA has contacted every owner/tenant that has had testing undertaken to date and provided them with the results. Other residents in Thebarton have also been provided with an update. The subfloor and indoor air testing results received so far indicate that three properties fell within a safe range, with no TCE vapour detected indoors, and five properties were found to be in the intervention range, between 20 to 70 micrograms per cubic metre of TCE detected indoors, and these will need mitigation action.

In line with the orphan sites policy, Renewal SA will be managing the installation of the mitigation system as an extension of the Beverley pilot project. It is important to note that two homes in Beverley have had systems installed that have successfully mitigated the soil vapour intrusion. The EPA has commenced discussions to formalise mitigation options as well as to progress any logistics regarding the timing for mitigation system installation in properties. The EPA will continue to work closely with each resident who lives in the area identified with high levels of TCE vapour in near surface soils and will continue to keep the community informed.