Edwardstown, 1102 South Road
Ground (bore) water contamination
In 2007 the EPA was notified that groundwater contamination at 1102 South Road, Edwardstown (on the corner of Daws and South Roads) had moved offsite, and had the potential to affect nearby properties in the area.
In August 2011, the EPA advised residents and commercial/industrial property owners with bores or groundwater wells not to use bore water for any purpose until further notice.
The contaminants identified were petroleum hydrocarbons and include benzene. These chemicals are essentially fuels and oils associated with fuel storage and vehicle maintenance. Once in the soil, they can move down to the water table and contaminate groundwater.
At this stage, the contamination is suspected to be the result of a former leaking underground petrol tank.
The EPA is working with the current site owners who have liability for the site contamination, to determine the extent of the contamination and a testing program has been developed in consultation with health experts and engineers.
The area is bounded by South Road to the east, Daws Road to the south, Carramar Avenue to the west and Dunorlan Road to the north.
Technical reports on this investigation are available on the EPA's Public Register. For information on how you can view or obtain a copy, click here.
Letters to residents
- Letter to residents, 6 August 2011
- Map of area under investigation, 6 August 2011
Frequently asked questions
How did the EPA become aware of groundwater contamination coming from 1102 South Road Edwardstown?
A notification relating to groundwater contamination at the site was received by the EPA on Wednesday, July 27 2011. As a result the EPA required additional information to be provided. Information received on Thursday, 4 August 2011, enabled the EPA to determine there may be a potential risk to off-site properties within the neighbourhood.
The EPA was originally informed about on-site groundwater contamination at this location in 2002. At that time, work was undertaken to remediate the site, including the removal of underground fuel storage tanks.
The notification received in July 2011 has been the first to the EPA since May 2003.
What are the chemicals of concern?
The contaminants of concern in the groundwater are chlorinated hydrocarbons, such as, perchloroethene (PCE), trichloroethene (TCE), dichloroethene (DCE) and vinyl chloride (VC), and petroleum hydrocarbons.
PCE and TCE are common industrial solvents and were used widely as dry cleaning fluids, degreasers and metal cleaners. DCE and VC are generally present as the result of the degradation and breakdown of TCE.
Petroleum hydrocarbons and benzene are liquid chemicals that readily flow and evaporate when released to the environment. Depending on how the chemicals were added to the soil, and the geology of the underlying soil and rock, it is likely that these chemicals migrated through the pores in the soil, dissolved in water and then flowed down gradient from the source or became present through breakdown chemical reactions.
Petroleum hydrocarbons like benzene are lighter than water. The hydrocarbon that is dissolved in water will migrate with the groundwater in the general direction of groundwater flow.
The chemicals of concern in the groundwater are petroleum hydrocarbons and includes benzene. These chemicals are essentially fuels and oils associated with fuel storage and vehicle maintenance. Once in the soil, they can move down to the water table and contaminate groundwater.
It is likely that the contamination is associated with historical leakages and spills associated with the use and storage of petroleum hydrocarbons at the site.
At this stage, the contamination is suspected to be the result of a former leaking underground petrol tank that EPA records show was removed in 2000.
For more information on the chemicals of concern, please refer to the fact sheets, chlorinated solvents, bensene and TCE from SA Health.
Can I use bore water?
Work to date has confirmed that the groundwater (bore water) in this assessment area is contaminated and should not be used for any purpose. Mains water and water from rainwater tanks are not affected by this contamination and home grown fruit and vegetables are safe to consume, provided they are not being watered with contaminated bore water.
Is there a soil vapour issue associated with the contamination arising from contaminated groundwater?
Works undertaken by environmental consultant AECOM during May and June 2016 focused on an area of approximately 1,340 properties in southeast Edwardstown and Ascot Park. All properties in the assessment area are considered to be safe, with predicted concentrations below 2 µg/m3 of TCE for indoor air.