SINGAPORE: The two water pipe bursts in Bukit Batok last week were caused by corrosion in the pipes, the director of PUB's water supply (network) department Michael Toh said on Wednesday (Oct 4).
Mr Toh was speaking during a site visit to Block 222, Bukit Batok East Avenue 3, where residents saw water shooting up several metres high at a carpark near the block after a water pipe burst last Sunday.
The incident came just days after a water pipe burst at Bukit Batok West, causing a three-storey-high geyser at a traffic junction.
The two leaks resulted in an estimated 7,580 cubic metres of water loss - roughly equivalent to three Olympic-sized swimming pools. About 7,500 cubic metres of water was lost from the first leak, and 80 cubic metres from the second.
As a result of the leaks, PUB will be conducting checks on all 100km of water pipes in Bukit Batok estate. Checks are expected to be completed by next week.
The agency will also replace the pipes in the vicinity of Bukit Batok Street 21, which are about 170m long, by December.
The pipe that burst at Bukit Batok West measured 700mm in diameter and was one of the major water pipes supplying water to the Bukit Batok estate. It had no prior leaks.
The second pipe at Bukit Batok East - which is smaller at 150mm in diameter -had two leaks on Oct 1 and one leak in 2012.
ACOUSTIC TECHNOLOGY TO TEST FOR LEAKS
Mr Toh explained that each kilometre of Singapore's 5,500km of water pipes is checked at least once a year. The last time water pipes in the Bukit Batok estate were checked was in January, and no leaks were detected then.
"All our pipes are laid underground; so the challenge for us is how do we have a look underground," said Mr Toh.
To test for leaks, PUB uses acoustic technology. Data loggers are temporarily attached to pipe valves, where they "listen" for increased noise - which may be an indication that a leak has occurred.
More sensors will also be installed in pipes to detect leaks.
Over the next two years, PUB will also renew 75km of older pipelines. More than 80 locations with old and leak-prone mains have been identified, including Serangoon Gardens, Hougang, Clementi, Bedok North and Stirling Road, as well as in industrial estates such as Kallang Way, Pioneer Sector, Benoi Sector and Tuas Road.
Mr Toh added that PUB takes each incident seriously.
"Every leak is disruptive, and in Singapore's context water is so precious to us," he said.