House of Assembly Fifty-Third Parliament, First Session (53-1) 53 1 Parliament of South Australia House of Assembly published Question Time Site Contamination, Clovelly Park and Mitchell Park Site Contamination, Clovelly Park and Mitchell Park Mr MARSHALL House of Assembly Dunstan Leader of the Opposition Site Contamination, Clovelly Park and Mitchell Park Mr MARSHALL (Dunstan—Leader of the Opposition) (14:44): Supplementary, sir. Can the minister explain to the house what is the trigger and when was it first breached? The Hon. S.E. CLOSE House of Assembly Port Adelaide Minister for Manufacturing and Innovation Minister for Automotive Transformation Minister for the Public Sector Site Contamination, Clovelly Park and Mitchell Park The Hon. S.E. CLOSE (Port Adelaide—Minister for Manufacturing and Innovation, Minister for Automotive Transformation, Minister for the Public Sector) (14:44): As I think has been explained a few times, although I accept it is quite arcane science knowledge required, the trigger is the two micrograms per cubic metre, as explained by the Minister for Health. Mr Marshall House of Assembly Mr Marshall: I thought that was the airborne— The Hon. S.E. CLOSE House of Assembly The Hon. S.E. CLOSE: That is the trigger. Mr Marshall interjecting: The Speaker House of Assembly The SPEAKER: Patience, dear boy! The minister. The Hon. S.E. CLOSE House of Assembly The Hon. S.E. CLOSE: I wish I had watched The Curiosity Show with more attention when I was a child so that I can better understand the science. As I understand it, what we are dealing with is the legacy of industrial practices where chemicals that were used pretty freely in our industrial past were often simply thrown away, dumped, put down pugholes. This is a general issue that we have. Some of that material has gone into underground watercourses and some of that will—and I do not know what the triggers are for that to occur or the mechanisms for that to occur—come up through the soil and become airborne. The point at which it becomes an airborne vapour at a greater concentration inside a house than two micrograms per cubic metre is the point that triggers investigation, and that is what has caused now the correct people to get together to make a determination and then to advise the residents.