The average water loss in the Danish water distribution network is below 10%. This level is among the lowest worldwide,and reducing the loss of drinking water is a global focus area.
Together with DTU, the water suppliers Nordvand and HOFOR and a number of other industry partners, AVK has joined the LEAKman partnership. The purpose is to implement state-of-the-art water distribution by using high-technology products and techniques and by tying components and software together into integrated solutions. The goal is to minimise water loss and major focus of this project is effective tracking and management of leakages.
Case: Klampenborg
As part of the LEAKman project, the two water suppliers Nordvand and HOFOR have each selected two areas where noise loggers will be installed. Automatic tracking ensures that leakages are quickly identified. This does not only minimise the water loss caused by leakages; it also prevents the damage from escalating and causing more serious financial consequences. At Nordvand they have already seen positive effects of the automatic loggers, as only a few days after installation, two leakages were identified.
Automatic tracking and reporting
Leif Koch A/S has developed noise loggers for automatic tracking. The leak noise behaves in a special way and can be recognised and distinguished from background noise by a microphone in the noise logger. Listening to the intensity and the frequency of the noise, the logger can identify and locate the leakage. The noise loggers can be programmed to 10,000 listening’s at a pre-defined time, typically between 2 am and 4 am when consumption and background noise are at a minimum. The signals will be sent as audio files to the water supply management system. If the logger recognises a leak noise, the audio file will contain a warning, and the water supply can then locate the leakage.
Placing the noise loggers
Each section of the distribution network is provided with a number of valves in order to be able to isolate a section which is as small as possible in case of pipe bursts or the need for establishing new pipes. The valves are spread across the whole section and thus, it is an obvious opportunity to place the noise loggers together with the valves.
Identifying leakages
Prior to installing the noise loggers, all valves in the selected area need to be checked to make sure that they are tight and function as intended.Then you need to decide where the loggers should be installed.
In Klampenborg, 125 noise loggers have been installed and two leaks were identified just a few days after installation. It is unlikely that these leakages would have been found without the automatic loggers. At least not in the short term.
One of the leaks was identified on a private pipe installation where the owner is usually responsible for the repair. In this case, it was fixed in cooperation with Nordvand, and the leakage was repaired in less than three weeks. The second leak was repaired within only one week after identification.
Before the noise loggers were installed in Klampenborg, leakages were detected at manual inspection of the distribution network. In this area they had a systematic but manual inspection every second year. So, without the loggers it may obviously take a while before a leak is identified – in Klampenborg up to two years. During this period, the water loss will be a significant cost, and it should be taken into account that over time, a leak may potentially turn into a pipe burst and cause even worse and more expensive damage. Leakage management is therefore an important tool to reduce water loss as well as costs.
Both Nordvand and HOFOR are already using automatic noise loggers at selected locations in their areas and as part of the LEAKman project, the whole Klampenborg district is now systematically monitored and on its way to absolutely minimise the water loss.