Neptune heralds smarter approach to managing leaks

A massive collaborative effort is under way to come up with new tools to help water companies manage their distribution networks more effectively. Tim Door, ABB's UK Water Industry Manager, explains

Water companies in England and Wales manage distribution networks that total more than 335,000km, according to Defra. And that does not include the almost 24 million connections to properties and associated customer supply pipes.

First there is the bad news: each and every metre of these pipes has the capacity to spring a leak. In 2008/9, water companies lost 2493Ml/d from the distribution network and a further 798Ml/d from supply pipes, adding up to a torrential 3,291Ml/d, according to the official figures from Ofwat.

The good news is that water companies have already made great inroads into the problems in their distribution systems, with leaks down by 5% in five years and by more than a third since they peaked in 1994/5.

No one doubts that it will take substantial effort and investment to keep this downward trend on track, but a collaborative project involving industry and academics promises to provide companies with a new set of tools to ensure that they are targeting their ongoing leak reduction campaigns as effectively as possible.

Project Neptune is a £2.7M, three-year initiative that aims to get companies working smarter by gathering and using real-time information on the pressures and flows in water distribution systems, not only to detect and repair leaks before they impact on customer supplies, but also to predict where failures are most likely to occur.

In principle, Neptune should enable companies to manage their networks and preventive maintenance programmes to prevent many leaks from happening in the first place.

Launched in 2007, Project Neptune is a strategic partnership between ABB, Yorkshire Water, United Utilities, the Engineering & Physical Sciences Research Council (EPSRC) and university researchers. The tools being developed will help improve operator understanding about what is going on in their distribution networks and enable them to take a more informed and integrated approach to three areas: pressure and energy management, information management and decision support tools.

The first step is to gather the data that the various models and alarms need to turn into useful information. This involves replacing traditional instrumentation with flow and pressure meters that can feed data back into the various Neptune applications.

Yorkshire Water had already started down this route before Neptune even started, with a programme known as RTNet which involved the replacement of existing manual logging equipment with systems equipped with onboard GPRS communications.

Some 1,800 loggers were deployed by 2009, which is around 35% of Yorkshire Water’s entire logger population. The company plans to extend this to all 6,000 loggers in its 31,500km distribution network over the course of the AMP5 investment cycle.

RTNet was initially trialled around the Harrogate and Dales area, with battery-powered devices transmitting data every 30 minutes. The system combines both flow meters and pressure measurement devices, which provide complementary data. For example, unexpected changes in flow tend to be good for spotting downstream events, while pressure is more sensitive to the head loss that results from a burst upstream. Combining the two parameters in the right way can drastically reduce the search area when on the hunt for a suspected leak.

The resulting data trail speeded up the detection and repair process during Yorkshire Water’s trial, with the company reporting that a burst that occurred before the system was implemented took around four hours longer to resolve than a similar incident during the trial.

Project Neptune takes the RTNet approach even further by using modelling to decide on the optimum placement of meters to maximise the sensitivity of the system using the fewest installed instruments. One of the key tools is an online hydraulic model that can interpolate from a few measurement points to infer the pressure and flow elsewhere in the system. The current status of the system can be continually updated, and short-term predictions can be made.

Another innovation that looks set to emerge from Neptune is a risk-based decision support system, which is designed to ensure that the distribution system operator responds in the optimum way to any abnormal conditions and minimises the impact of any leaks on customer supplies.

There are two distinct aspects involved in assessing the risk of a burst. The first is analysing the chances of a particular burst occurring. The second is calculating the impact of a burst, should it occur. This information can then be used to prioritise alarms, so that those most likely to cause a big problem for customers get dealt with first.

The likelihood of a pipe bursting is decided on the basis of three models: the pipe burst prediction model, the hydraulic model and the customer contacts model. The first of these looks at the age and types of assets in the relevant section of the distribution system.

Once this part of the model is defined it remains static. In contrast, the hydraulic model is constantly changing as the real-time flow and pressure data enters the system. The customer contacts model also changes dynamically, according to the level of problems reported by customers. The results can be presented in easy-to-use formats, such as risk maps over a given district metering area.

Operators can also run manual “what if” scenarios to predict what impact different isolation strategies or other actions would have.The aim is to close the loop between the control room and the field: collect data from the assets and transmit it to a central point; analyse the data and transform it into useful information; respond to the information and model potential responses from the control centre.

Pilot tests of the new systems are being carried out in the distribution network of both Yorkshire Water and United Utilities. All the new tools and applications are deployed using one of ABB’s newest open platforms, the 800xA control system, combined with the closely integrated historian (PGIM) system.

Neptune is due wind up by the end of 2010, soon after which ABB expects to commercialise the tools as a software package, subject to agreement with its partners on the project.

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