Legislative Assembly for the ACT: 2006 Week 2 Hansard (9 March) . .
(Question No 870)
Mr Prattasked the Minister for Urban Services, upon notice, on 14 February 2006 (redirected to the Chief Minister):
(1) What was the cause of the burst water main that ruptured in Jackie Howe Crescent, Macarthur on Wednesday, 8 January;
(2) Given that ActewAGL has stated that the quality control was not what it should have been", what is being done to ensure that adequate quality control is being undertaken at all water main installations;
(3) How often has the ruptured water main in Macarthur been surveyed in order to attempt to identify problems that may exist before they progress into more significant problems, as evidenced by the Jackie Howe Crescent incident;
(4) What is the method currently undertaken to identify potential weak-points or other problems in the water network, how are they identified, what occurs once they are identified and how often are inspections undertaken of the network;
(5) Of the 573 burst water pipes last financial year within the ACT network, what is the estimated volume of water lost due to these bursts and what is the estimated total cost to the Government due to repairs and other associated damage costs;
(6) What is the cost to the Government regarding the burst water main in Jackie Howe Crescent on 8 January 2006;
(7) Are any programs of pipe replacement planned for this financial year; if so, where will they occur and how much will they cost.
Mr Stanhope: The answer to the member's question is as follows:
(1) I am advised by ActewAGL that, as with most burst mains of this nature, it is extremely difficult to be certain of the cause. Canberra soils are susceptible to movement as moisture levels vary and this may have been the cause.
In any case, the main that failed in Macarthur is relatively 'young' (about twenty years old), did not have a history of repeated failures, and no leak was evident prior to the burst. The failure is considered a random event.
(2) Contractors lay major water mains and sewer mains, usually for land developers in new subdivisions. Quality control is a matter for land developers and they are liable for any failures in the first 12 months of operation.
(3) It is generally not feasible to inspect underground pipes looking for potential faults, and such inspections are not water industry practice except where mains are very old or fail repeatedly. Canberra's water network is relatively young and, as stated above, the main in question was about twenty years old. Advance warning of failures like that in Macarthur would be exceptional, except perhaps by a leak, and as stated above, no leak was evident in this case prior to the burst.
(4) Where a section of water main has repeated failures, it will be carefully assessed and replaced where judged advisable.