Prévenir l’intrusion de pathogènes : comment Bergen Vann a utilisé la surveillance de pression à haute fréquence pour protéger le réseau d’eau potable (en anglais)

Bergen Vann, the municipal water utility in Bergen, Norway, manages a complex distribution network serving residential, commercial and industrial customers. Maintaining continuous system pressure is critical to prevent contamination, as groundwater and trench water can be sources of contamination during depressurization or vacuum conditions in the pipeline network. Even if the work area or the exposed section of the pipeline is protected against trench water intrusion, it is still possible for groundwater or trench water to leak in through small cracks and holes.

Cloud-Based Pressure Transient Detection and Analysis

To assess the potential for drinking water contamination due to the intrusion of pathogens during low or negative pressure events, Bergen Vann conducted a study using high-resolution pressure monitoring tools. Pressure transients are usually far too fast to be detected by standard pressure loggers, which is why in this study, 15 PIPEMINDER high-resolution pressure loggers, which measure pressure at 128 samples per second, were deployed.

These devices have a measurement range of 0–20 bar (0-290 PSI) with an accuracy of ±0.25%. They feature automatic time synchronization via the mobile network and come with dedicated SIM cards for communication. The loggers are IP68-rated and can be installed in water-filled chambers. Using the network architecture and historical information about likely pressure surge locations, the pressure loggers were installed in different parts of the water distribution system, including in valve chambers with service valves.

Data from the pressure loggers is transmitted to RADAR^®, a secure, cloud-based platform combining powerful data analysis with a simple and easy-to-use interface. RADAR provides Bergen Vann with a detailed view of network activity including algorithms that identify and transmit pressure transient data based on system-defined levels. The software also includes shape classification for identifying pressure variation patterns and can classify data as oscillations, rapid pressure drops, pipe bursts or pump starts. Using utility-provided GIS data about the pipeline network (coordinates, diameter, pipe material, etc.), RADAR can use the time-synchronized pressure data to locate the source of the surge through network triangulation.

At Bergen Vann, advanced pressure monitoring with PIPEMINDER helps the utility keep an eye on pressure events in the drinking water network.

Uncovering Risks and Driving Resilience

Approximately 40% of pipeline breaks in Bergen must be repaired while the network is depressurized. There are also many other planned depressurized events where the water distribution network is shut down; such as private pipeline repairs, maintenance of the public water network and construction work.

Approximately 40% of pipeline breaks in Bergen must be repaired while the network is depressurized.

Contamination and Hydraulic Stress Exposure

Water samples from valve chambers revealed E. coli and enterococci. This indicates a significant risk of microbiological contamination of drinking water if water from water-filled manholes, trench water, or groundwater enters the pipeline network during these pressureless episodes. Pressure surges of up to ±4 bar (±58 PSI) were also recorded once monitoring began. Such pressure fluctuations impose stress variations on the pipe, which can reduce its lifespan and lead to fatigue fractures and costly repairs.

Identifying and Mitigating Pressure Surge Sources

With the GIS data in RADAR, the source of the pressure surges could be triangulated and detected to be primarily caused by industrial consumers and rapid valve operations. For example, one source of the pressure surges was identified as a laundry facility that draws water directly from the distribution network without regulation. The daily water consumption of the laundry facility is low, averaging about 20 m³/h, but withdrawals of 50 m³/h over a short time interval cause the pressure in the water pipeline network to fluctuate significantly, with an amplitude of approximately 4 bar (58 PSI). This results in a pressure surge of around 8 bar (116 PSI), which is highly damaging to the water pipeline network. Bergen Vann contacted the customer and conducted a physical inspection to assess the equipment at the customer's intake. Together, it was concluded that installing a tank would help to even out water consumption and counteract pressure surges.

The customer installed a buffer tank, which led to a significant reduction in pressure surges, decreasing stress on the distribution network and lowering the risk of pathogen intrusion. Overall, the high-frequency monitoring technology gave Bergen Vann unprecedented visibility into pressure dynamics, helped to pinpoint problem areas and work with customers to mitigate risks effectively.

PIPEMINDER installed on a service valve for drinking water distribution in Bergen, Norway.

Based on the initial study findings, Bergen Vann intends to install additional units permanently in the distribution network.

Advancing Distribution System Protection

By leveraging analytics and advanced pressure monitoring with PIPEMINDER, Bergen Vann significantly reduced contamination risks, improved operational resilience and reduced stress on the network. The project demonstrates how smart technologies can transform water network safety and efficiency.