The two corroded water pipes that burst in the space of a week in Bukit Batok about a month ago were unrelated incidents, checks by the Public Utilities Board (PUB) found.
Minister for the Environment and Water Resources Masagos Zulkifli, revealing this yesterday in a written reply to a parliamentary question, said no additional leaks were detected in the area.
The pipes, one in Bukit Batok West Avenue 6, the other in Bukit Batok East Avenue 3, had burst on Sept 26 and Oct 1 respectively, spewing water several storeys high and causing localised flooding.
National water agency PUB had said initial observations indicated the leaks were due to corrosion.
Mr Murali Pillai (Bukit Batok) following up on this, asked what steps would be taken to prevent a similar occurence in future.
Mr Masagos said the leaking section of pipe at Bukit Batok West Avenue 6 has been replaced, and all 170m of water pipes at Bukit Batok East Avenue 3 are being replaced. The work is expected to be completed by the end of this month.
Both pipes, which were laid about 35 years ago, were well within their "design lifespan" of 70 years, he said. They had been checked in January and were found to be in good condition, and were due for inspection again in January next year.
Pointing to Singapore's track record of having about six leaks per 100km of pipes per year, he said this was "among the lowest incidences in the world".
He added that this was achieved through continuous monitoring of pipes with more than 300 sensors. All pipes in PUB's 5,500km network are also checked physically for leaks at least once a year.
In addition, the PUB is increasing its pace of pipe replacement.
Despite this, localised corrosion may occur in places where the water table is particularly high, and where the soil conditions are harsh, said Mr Masagos, adding that uneven soil settlement or damage from construction work can also cause leaks.
"While we aim to replace all faulty pipes before they fail, leaks like the ones which occurred in Bukit Batok will happen from time to time," he said. "PUB seeks to respond and fix the problem quickly, and most incidents are resolved within a few hours."
Seow Bei Yi