Going beyond the body shop
A profile of Subterra and the changing approach to leakage control
The engines of change are legislation and regulation: the new Roads and Streets Act will increase the cost of digging up the road, the Competition Act will mean dealing with independent connections and what Samorzewski describes as "more mature" clients, while the new regulator appears to be taking a softer line on levels of economic leakage.
Similar to gas market
Leak detection and prevention was once "body shop work," according to Samorzewski, a matter of supplying bodies to hunt for holes. Success in the new marketplace, he believes, will require full pipeline network management skills, not just the ability to find and reduce leaks. The basis for this belief lies in Samorzewski's experience of the gas industry, where he held a senior position with Transco. The water industry's current position Samorzewski describes as "uncannily similar" to that of gas in the early days of competition, with the same issues, culture, even the same language; gas also underwent an intensive period of "asset sweating". Hence Subterra is seeking to provide the kind of technological solutions which have succeeded in the gas sector.
Subterra's approach to leakage problems includes mapping assets and breaking the network down into manageable district metered areas (DMAs). This provides an understanding of how the system is working and where and why problems are occurring.
A leakage assessment and investigation programme for North of Scotland Water (NoSW) at Mallaig exemplifies this approach. A NoSW preliminary study into the supply capacity of a new membrane treatment plant suggested excessive leakage with a night flow of 27l/s.
Due to the age of the network, mix of pipe materials and lack of reliable flow and network infrastructure data, Subterra delineated five DMAs and installed new meters and flow monitoring equipment. The metering programme showed the level of leakage was not as significant as NoSW believed, a night flow of 16l/s was confirmed.
Taking into account known commercial usage and having carried out property counts, the level of unaccounted for water was calculated to be 11l/s. The quality of the new data meant the leak detection phase was carried out with a more direct targeting of resources than could have previously been managed.
The favoured method of leak detection was Step-testing because it provided a means of quantifying the leakage on the long lengths of cross-country mains. In addition the company carried out a survey of major assets using global positioning system (GPS). Asset mapping is becoming a growing area of activity for the company, with some water companies investing very heavily as accurate calculation of asset value becomes increasingly important.
Subterra believes its approach will make technology and information more easily available to asset managers. In this way the company thinks its emphasis is shifting from being a contractor to a service provider.
Alongside Step-testing, Subterra deploys leak detection systems such as Aqualogging, Permalogging and Radcom Soundsens. Permalogging has proved a very efficient tool for the extensive work Subterra undertakes in the urban areas supplied by Thames.
When it comes to repairs Samorzewski refers to Subterra as a "pioneer of no-dig technology," which he said was "the biggest cost-saver we can offer any utility." Section 71 of the new Roads and Streets Act, the legislation comes into force in 2001, means utilities will have to 'rent' sections of road they need to dig up for £1,000 per day. Fines will then be levied for failure to finish on schedule.
The company has developed products like Rolldown, Subline and Subcoil, the latter systems share the same principle of red-ucing the cross section of a thin-wall polyethylene pipe liner - it is folded into a 'U' shape, so it can be pulled through an existing pipeline and then reverted by compressed air into an 'O', filling the damaged pipe and stopping any leaks.
Subline is designed for renovating large-diameter pipelines, with liner folding taking place onsite. Subcoil is a smaller version of the system, designed for use on mains, which is supplied in factory folded lengths delivered on van-towable coils. The system was developed by Subterra and refined in conjunction with North West Water. It is deemed particularly suitable for long pipe runs, up to 1km can be carried on a single coil, in rural areas.
Because thin-wall polyethylene is flexible and the liner offers little resistance when pulled through the pipe it is able to follow bends in main. Service points are installed using a special ferrule, the liner will safely bridge gaps of up to 80mm and holes of up to 60mm in diameter.
Subterra was formed six months ago following the merger of Subterra Rehabilitation, Metro Rod and Total Pipeline Solutions. Although it is part of Thames and has a framework agreement with the company, Subterra does a lot of work with other water companies. The company is planning to increase its overseas operations - currently there are clients in Puerto Rico, Trinidad and Turkey - but Samorzewski believes the former eastern bloc countries offer a particularly lucrative market owing to years of under investment in water pipeline infrastructure. Following a period of restructuring to turn the business into a more client focused operation, Samorzewski is confident Subterra is now in a position to take advantage of these and many other opportunities.