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Cleaning inaccessible water reservoirs using remotely operated vehicles

Published 20 Mar 2023 (updated 29 Apr 2024) · 3 min read

Quick information

  • Available

At a glance

  • ROV for cleaning drinking water tunnels
  • Eliminates the need for shutdown and emptying
  • Ensures safe, sustainable drinking water

The Tunnel Remotely Operated Vehicle (TROV) cleans water tunnels and reservoirs, ensuring clean drinking water for residents and sustainability in private and municipal water systems. “The TROV is the world’s first remotely operated device for cleaning long, inaccessible drinking water tunnels,” says Frank Mohn, CEO of W. Giertsen Water Technology.

A few years ago, several Norwegian municipalities realised that their potable water could be at risk of contamination due to build up of sediments on the floor of their storage and distribution tunnels. The water tunnels and reservoirs had not been cleaned for 30 to 40 years. Humans could no longer walk into the tunnels due to HSE risks, and a lack of redundancy made it impossible to shut down tunnel basins for cleaning.

“A consortium of waterworks searched worldwide for a solution, but came up empty handed. So they issued a tender for an innovative concept: an unmanned robotic cleaning device that would pump sediment out of the reservoirs,” explains Mohn.

The TROV won the competition.

TROV cleans inaccessible drinking water reservoirs

The TROV is a remotely operated cleaning device for inaccessible water tunnels, reservoirs and caverns. The solution eliminates the need to shut down, empty and manually clean the water storage spaces. Using the TROV also enables utility owners to obtain water and sediment samples from deep in the water reservoirs, which can give valuable insight into the condition of the facility.

“We have developed an ROV with wheels. It’s like a huge vacuum cleaner that sucks up the sediments and transfers them out of the reservoir ,” says Mohn. “The sediment itself is not dangerous. However, it may become an incubator for harmful bacteria and parasites.”

Powered by electricity, the TROV moves on tunnel floors on wheels. Trained operators control the vehicle from the safety of a control room. Pumps, motors, transformers, lights and cameras are installed in the TROV chassis.

The TROV is built on years of experience from the offshore sector with rigorous demands linked to HSE and quality assurance.

Industrial machine inside cave

TROV increases sustainability in potable water

“Our solution is mainly about increasing the safety of drinking water for residents,” says Mohn. To his point, the TROV fully complies with requirements set by the Norwegian Food Safety Authority.

Moreover, the TROV can extend the life of potable water reservoirs through regular cleaning. “We promote sustainability in drinking water systems by protecting our most important natural resource,” he adds.

In turn, sustainable water management leads to cost efficiency. Internationally, water infrastructure in many large cities is 100 to 150 years old and replacing old water and sewer systems can be prohibitively expensive. State-of-the-art cleaning with the TROV could potentially extend the service life of urban infrastructure.

Huge adjacent markets

As the need for clean drinking water is ubiquitous, the TROV’s market potential spans the globe. The TROV will be useful in any country with inaccessible water reservoirs, raw water tunnels and long hydropower tunnels. It can also be used for hard-to-clean waterways and canals.

“In Norway alone, authorities estimate that USD 32 billion will be spent on upgrading the national drinking water and wastewater infrastructure over the next 20 years,” says Mohn.

The TROV’s developer, W. Giertsen Water Technology, is currently cleaning all the tunnels and reservoirs in Bergen municipality. It will soon build a second TROV and, eventually, an entire fleet.

The TROV adventure is just beginning. Mohn sums up by extending an invitation: “If you need to clean an inaccessible body of water, please get in touch. Our engineers envision many applications and uses for the TROV-technology.”

Frank Mohn


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Nygårdsviken 1, 5165 LAKSEVÅG, Norway

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