Replacement of water pipes to be carried out urgently

PUBLISHED : Wednesday, 02 September, 2009, 12:00am
UPDATED : Wednesday, 02 September, 2009, 12:00am

Eight sections of fresh and seawater pipes underneath Gloucester Road would be replaced earlier than scheduled, the water chief said as he apologised for Monday's burst pipe that led to traffic chaos on Hong Kong Island.

Ma Lee-tak, the director of water supplies, vowed to fast-track programmes to replace the remaining section of the burst pipe and seven others cutting across the busy section between Arsenal Street and Marsh Road.

Under the previous plan, the burst section was supposed to be replaced early next year while the rest of the pipes were to be replaced no later than 2013.

While no new timetable was given, Ma expected the works could be completed within six months. Works details and traffic arrangements had to be further discussed with the Transport Department, Environmental Protection Department and police.

Replacement work would be done between 10pm and 6am, subject to noise control conditions

It was estimated that completing pipe work on one lane would take three nights. The road had at least four lanes in each direction.

Apologising to the public yesterday, Ma also revealed that the 23-year-old burst pipe had been inspected on August 15, when no signs of leakage were detected.

'We found no problem with the pipe and so we believe the pipe just deteriorated suddenly,' he said.

To improve monitoring of leaks, Ma said the department would send two engineers to the US next week to study the latest detection technology, in which a camera is inserted into the water mains to find leaks.

Ma also defended the progress of a programme to replace old pipes. He said 30 kilometres of pipes were being renewed each month, double the figure for last year.

As of July, about 1,000 kilometres of pipes had been replaced across the city under the HK$19 billion pipe scheme to replace 3,000 kilometres of pipes by 2015.

Damien Ku Chi-chung, president of the Hong Kong Institute of Utility Specialists, yesterday said Monday's burst water mains pipe could have been avoided if monitoring had sounded the alarm early enough.

'The water officials could have isolated the pipe or regulated the water pressure to buy time for the pipes if they had learned about the leakage,' Ku said.

The 'noise logger' leak test now used in the city was flawed when it came to detecting large leaks and leakage at joints, he said. In those cases, the pipes could deteriorate rapidly as soil might have been washed away, making their foundations even more unstable.

He said it was now time for the community to debate how the water mains replacements should be carried out.

Democratic Party legislator Kam Nai-wai yesterday said the Water Supplies Department should speed up not only the replacement of pipes across Gloucester Road, but also under roads into the tunnels.