Water & Wastewater Treatment Magazine
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Steady supplies Supply interruptions are one of the biggest sources of frustration for customers, but there are solutions that can help tackle the problem By Robin Hackett www.wwtonline.co.uk | WWT | SEPTEMBER 2018 | 27 Innovation Zone Reducing supply interruptions W hile previous Innova- tion Zone features have examined solutions that can help detect, predict and reduce leaks and bursts, water companies must also have solutions in place to minimise disruption caused by supply being interrupted, either through emergencies or for planned works. Ofwat's common perfor- mance commitments for PR19 include reducing the number of supply interruptions greater than three hours. Here we assess some of the options available to keep supplies running as well as to speed up repair work. GOAL 4 SUPPLY INTERRUPTIONS Overland Supply Service (Aquam) Aquam offers vehicles that each contain all the equipment required to restore drinking water to households. Though originally planned for emergency situations, the system can also be used during scheduled repair work to prevent loss of service. A single Overland Supply Vehicle (OSV) will contain all the hoses, fittings, tools and equipment necessary to build a bespoke water network for 24 houses, as well as the signage, barriers and ramps required for streetworks legislation. Each vehicle is manned by two trained technicians and features an Overland Supply Manifold (OSM), which becomes the hub of the temporary network. The OSM – the section onto which smaller pipes are connected – is a solid machine-cut nylon device, designed to be significantly more adaptable and robust than traditional manifolds. The OSVs also contain pressure-reducing valves, which can be used to help ensure supply is safe and stable, while water meters can be fitted to measure usage and avoid it being classed as 'unaccounted for'. Designed by Roman Boryslawskyj, a former Yorkshire Water operations manager in water supply and networks, the Overland Supply Service was developed to ensure companies could keep disruption to a minimum amid growing regulatory pressure to keep customers happy. Alternative and Emergency Drinking Water Supply Equipment (Arlington Water) This flexible, modular system can be used to address both planned and unplanned events and includes as standard the Arlington Emergency Water Tank (AEWT) – a 1,000-litre capacity water supply tank – as well as the Always in Supply (AiS) variable speed, digitally controlled pumping unit. The AiS, developed in conjunction with Thames Water and is now in widespread use by a number of UK water companies, is able to pressurise almost any section of isolated pipework and can be used to deliver water in a range of situations from individual properties to entire housing estates, factories and villages, as well as being used to boost low-pressure areas. The AEWTs can either be used on their own as gravity-fed static tanks or in conjunction with the AiS. Known as 'bag-in-box' tanks, AEWTs feature DWI-approved liner bags, which are replaced for each deployment, minimising cleaning requirements. The tanks can be filled from a hydrant, boundary box or stopcock in the case of a planned interruptions, from tankers or delivered full to site in the case of emergencies. Tests have shown that the water quality is maintained within the AEWT for well over a month, although utility company internal deployment standards will probably apply. The basic AiS system – which includes the pump, tanks and the required power sources – can be brought to site in a single van, but its modular nature means it can be made significantly larger if required, with the AEWTs able to be stacked five high. In addition, Bluetooth connectivity in the AIS units means they can coordinate across a large area, with several infusion points set up on a single area of network, which allows the units to work as a single system to maintain the desired flow and pressure.