Tackling leakage from all angles

Finding leaks on transmission pipes and trunk mains can be especially challenging and with water utilities on the lookout for emerging technologies to tackle this issue, a satellite leak detection project in Africa appears to show that there are solutions at hand, as Jonathan Jacobi of satellite-based infrastructure intelligence firm Utilis explains

Marking a likely leak location

Supply interruptions and water losses from leaks on transmission pipes and trunk mains can be some of the most challenging issues water utilities face given the large diameter of the pipes and the materials of which they are made.  But a new satellite leak detection technology is making finding the leaks a lot easier.

Drinking water pipelines are one of the sector’s largest and most expensive capital assets and maintaining their integrity must be a key priority. In order to achieve this, the reduction of water losses is a strategic necessity.

In October 2019 a pioneering pilot project was carried out on more than 1,000km of transmission mains in the south of Africa using Utilis’ satellite-borne L-band synthetic-aperture radar (SAR) analytics. Points of interest on the vast trunk main network were narrowed down using the technology, then specialist acoustic leak detection equipment from Swiss water loss technology company Gutermann was used to verify them and pinpoint leaks.

Utilis 4 SARS image with pipe layers overlayed

While traditional leak detection techniques and instruments are less suitable for surveying large stretches of large-diameter pipes in rural terrain, Utilis’ technology is agnostic to pipe size or material, identifying leaks via soil moisture created by potable water mixing with the surrounding earth. The technology’s ability to pre-localise a leak, especially in such a difficult landscape, allows the surveying team to invest the time and equipment needed to pinpoint leaks, helping raise their efficiency and meet key performance indicators (KPIs).

Through random sampling, a total of 30 locations were identified for site investigation and verification in this project. This was followed by a leak validation exercise to mark the location and confirm the presence of a leak using Gutermann’s AQUASCAN TM2 trunk main leak correlator. This correlator is specialised in analysing the leak noise on large-diameter pipes and over distances of up to and sometimes even more than 1km distance. When the pipe distance and properties (material and diameter) are known, the correlator is able to pinpoint the leak extremely accurately.

The leak detection teams were able to locate leaks at all 30 locations, exhibiting 100% accuracy for the SAR technology and evidencing a highly effective job carried out by the teams in the field.

Wake-up call

The need to protect water supplies has never been more urgent. According to the World Resources Institute, demand for water has increased by 600% worldwide over the past 100 years and water utilities face challenges from aging infrastructure and vast networks spanning both urban and rural environments.

Utilis’ remote-sensing technology uses a sensor mounted on a satellite orbiting at 637km above earth, which means it can capture an entire network in one shot. It has the potential to capture thousands of leaks using a patented algorithm that identifies the unique signature of drinking water escaping into the ground.

Using satellite analytics helps companies identify hot spots to investigate further so that leaks can be targeted before surfacing, reducing potential damage to nearby infrastructure and the environment.

This is particularly useful in rural areas as it is traditionally much harder and more time-consuming detecting leaks in remote locations. In addition, the approach is non-invasive, can be frequently updated and is highly scalable.

“Fixing leaks is not just about stopping water-loss once we are already aware there is an issue, it is also vital to pre-empt problems and prevent further collateral damage to the infrastructure and environment,” said Uri Gutermann, chief executive of Gutermann. “There are solutions available to alleviate the pressure on water supplies and by harnessing technology and data to make intelligent, long-term decisions, utilities are better placed to tackle this growing problem.”

Cutting costs and water loss

Satellite leak detection offers utilities much lower operating costs, with no preparations or upfront investments required. Leaks can be located faster, resources can be managed more efficiently, and background losses reduced, all resulting in decreased water losses.

Since developing the technology in 2016, Utilis has worked on over 250 projects worldwide in countries including the US, UK, Italy, Chile, China and Africa, leading to more than 30,000 leaks verified and saving customers around 19,000 million litres (5,000 million gallons) a year.