CONTAMINATED WATER

In reply to Ms CHAPMAN (Bragg—Deputy Leader of the Opposition) (1 July 2008).

The Hon. J.D. HILL (Kaurna—Minister for Health, Minister for the Southern Suburbs, Minister Assisting the Premier in the Arts): I have been advised:

1.&2. The issuing of health alerts is done in accordance with established public health principles, the basis of which is a thorough assessment of the level of risk to the public. Not all contaminated sites pose an immediate threat to public health.

In relation to the General Motors-Holden (GMH) Woodville site, the Department of Health was notified in 2001 that chromium and petroleum hydrocarbons had been detected in shallow groundwater beneath the SA Manufacturing Park at 853-867 Port Road. Chromium was reported to be detected at concentrations exceeding the Australian Drinking Water Guideline value in some of the monitoring bores located on this site. The groundwater flow in the area is in the westerly direction. No chromium was detected in an off-site monitoring bore located down-gradient, approximately 50 metres to the west of the western site boundary.

A portion of the GMH site has been redeveloped for a commercial bulk-goods activity (Bunning's warehouse). The site is bounded by industry and a cemetery to the west, a racecourse to the north and mixed residential-industrial areas to the east and south. A search of registered bores recorded in the Department of Land, Water and Biodiversity Conservation drill hole enquiry system identified several bores within a one kilometre radius of the site. The only down-gradient registered bore in close proximity to the site is a drainage bore which is not used to extract water. There are some registered bores located to the south-east which are up-gradient (upstream of the groundwater flow) of the site.

Based on the flow characteristics of the groundwater and the location of residences, it was deemed that there was little risk to human health from chromium contamination of shallow groundwater at this site and no public health warning was issued by the then Department of Human Services.

The Department of Health recommends as a matter of course, that bore water is not to be used for drinking, cooking or watering edible plants without testing to prove suitability. Shallow unconfined (that is, bores that extract water from aquifers that are not confined between layers of impervious rock or clay) bores are the most susceptible to contamination and are not recommended for domestic use.