Dragages et Travaux Publics (HK) Ltd has been awarded from Water Supplies Department Contract No.20/WSD/02 Leakage Detection of Buried Water Mains Affecting Slopes – Second Five-year Cycle. The Letter of Acceptence was received by the company on 21 February 2003 confirming the award of the contract with a contract sum of HK$33.9 million.

The Contract involves leakage detection survey on prescribed water main and drain sections maintained by WSD buried behind or in the vicinity of slope and to coordinate with relevant parties and report the survey results. A total of 4,300 pipes will be detected within the entire Hong Kong Special Administrative Region comprising 27% on Hong Kong Island, 24% in Kowloon and 49% in the New Terrirories. Total length of pipes to be detected reaches a total of 800km with a contract period of 1,190 days separated into seven work Sections.

The technique involves primarily the use of Leak Noise Correlators (LNC) connected between two prescribed contact points of a pipe to pin point leakages. A LNC consists of two microphones (sensors), two hydrophones and a correlator. The microphones are attached to contact points while hydrophones are attached to the hydrants along the water main to be surveyed. The correlator is used to cross correlates the leak noise reaching the microphones to calculate the leak position. The accuracy of measurement is within 0.5 metre.

As the technique used is relatively new, the project falls within Dragages’ business development strategies to diversify into less intense markets. As more and more infrastructure begins to age the demand for preventive maintenance works will inevitably grow.

To optimise on resources and at the same time explore new markets, an office is intended to be opened in Shenzhen (PRC) for data analysis and the preparation of reports. This will enable the company to establish a foot in the PRC in respect of staff members.

Mr. Luc Messier, Managing Director of Dragages, said “We treasure the opportunity to serve our new client WSD in this innovative and logistically demanding project and look forward to its successful implemention and completion. This will pave for many more demanding and innovative projects in this field including those under a BOT/PFI scheme which may be offered in future by WSD and other clients. This may include tunnels and water treatment plants”.