Utility took on leakage – and won

In the financial year 2007 to 2008 Scottish Water failed to meet its leakage reduction target for the second year running. Natasha Wiseman spoke to the utility on how they turned things around and are meeting new targets

In a recent public statement, Scottish Water has described how it has saved more than 180 million litres of water a day since being set new targets for reducing leakage by the regulator two years ago. Paul Kerr, head of leakage delivery at Scottish Water, told WWT that the company is now on track to meet its leakage target.

“We are clearly on the road to meeting and beating our target for the end of the financial year. We are on course to achieve a record level of reduction in water leaking from our water network,” he says.

In 2007 to 2008 Scottish Water failed to meet its leakage reduction target for the second year running. The company had decreased its reported leakage from 1,004Ml/day to 924Ml/day – but this was still 69Ml/day short of its target of 855Ml/day.

Reducing leakage

The regulator, the Water Industry Commission for Scotland (WICS), stepped up its monitoring of Scottish Water’s progress, and the company has responded by increasing investment in mains monitoring and repair, and doubling the number of engineers and technicians it employs in leakage reduction. WICS says targets set in 2006 are designed to be a first step towards Scottish Water reaching its economic level of leakage – the point at which the cost of reducing leakage is the same as the cost of the water lost. The utility is financed to move 50% closer to its economic level of leakage by 2010, and its economic level of leakage by 2014.

Head of leakage delivery, Paul Kerr, told WWT of installing monitoring equipment in district monitoring areas (DMAs) across its 47,000km network of water mains. Some DMAs have been rationalised, and now 96% of properties in Scotland are covered.

The utility believes this will ensure resources are targeted in the right areas. A national pressure management programme was also undertaken and capital funds have also been committed to the installation of pressure relief valves.

According to Kerr, it was easy to identify the Central Belt as the area where the greatest savings could be made, given that this is the most densely populated part of Scotland. An estimated 2Ml/d of drinking water is being saved in just one area of Glasgow, while the Edinburgh Leakage Delivery team has fixed more than 2,000 bursts, including six on the main trunk main serving the capital. The utility estimates that work by the Edinburgh team, which was set up in April 2008, is saving around 10Ml/d of water.

Another leakage blackspot was Coatbridge in Lanarkshire. A £120,000 project there involved splitting up the Sunnyside DMA into smaller areas and installing pressure-management valves. A reduction of 3Ml/d has been achieved.

Some of the success in reducing leakage in the Inverness area by 2Ml/d has been attributed to Halma’s wireless Permanet system. The technology communicates wirelessly with Permalog+ loggers to collect leak data and then transmits this information directly to an office computer or mobile phone via low-cost SMS telemetry.

With a permanent network of acoustic noise loggers in constant communication and a centralised data-management system, Halma says potential leaks can be instantly identified and targeted for investigation and repair. The advantage for the utility is that the technology negates the need for repeated and time-consuming patrols by anti-leak teams, allowing them to concentrate their time and effort more efficiently.

Additional benefits

The collected data can also be used to lower minimum night flow rates according to need. Halma says reductions of up to 50% have been recorded by the Permanet system in use by Yorkshire Water.

Kerr is keen to explain the additional benefits to the company that its leakage reduction measures are delivering. Reduced water volumes are bringing energy savings across the network – including pumping, treatment and sludge disposal. A reduction in chemical use at treatment plants has also been achieved.

Sustainable water management is now a key issue in the water industry and over the past 12 months Scottish Water has reduced its energy consumption by 9%. Kerr says that its leakage reduction programme has contributed to that figure.

Peter Farrer, director of customer service delivery told WWT that the reduction in leakage had reduced the overall water in the distribution network by 172Ml/d to 2,140Ml/d.

“We will be asking customers to look after their water and we must do the same. This achievement means we produce less water for our distribution network, saving energy and costs,” he says.

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