Water & Wastewater Treatment

www.wwtonline.co.uk | WWT | AUGUST 2015 | 13 Project focus W essex Water is progressing well with its Water Supply Grid project, its major £225M scheme aimed at ensuring security of supply for customers by linking up multiple water sources and enabling smooth transfers around its area. Pipes and pipelines Water Supply Grid takes shape for Wessex Project focus ● £225M project on course for completion in 2017 ● 74km transfer main provides key link between south and north ● Grid to ensure future security of supply for customers new or refurbished pumping stations and 12 new storage tanks, ranging in capacity from 2 to 8 million litres. The centrepiece is a 74km transfer main leading from a new major pumping station at Sturminster Marshall in Dorset to a new storage tank at Camp Hill just west of Salisbury. This transfer provides the key link between Wessex Water's infrastructure in the south – where water is relatively plentiful – to the north, where it is less so. The aim is to ensure continued security of supply for customers, wherever they live in Wessex's region; the utility has not needed to have a hosepipe ban since privatisation, and wants to keep it this way. Wessex Water also wants to link up communities currently relying on a single source, such as a borehole, into an area-wide grid to tackle the risks of localised water quality problems in future. (Wessex gets 70% of its water from aquifers). There were 14 such 'standalone' sources before the start of the project, as well as four sources where low flow was a concern and 12 sources where nitrate levels were identified as a possible future risk. The completion of the grid will alleviate all of these concerns at once, while also preparing the ground for a number of abstraction licence reductions – in particular around the Salisbury area - due to take place in 2018. "What it means for our customers is that whether you are a customer in Dorset, Wiltshire or Somerset, come 2017, you have security of supply if water is scarce," says Drummond Modley, Wessex Water's programme manager. "Whether there is a drought or a technical problem with your local water source, you will always be able to get water." The grid will also open the door to water trading with neighbouring companies in the region on a scale that has not been possible before. Modley says that the programme of work is around 60% complete; there is 8km remaining to be completed on the main transfer pipeline route. £1M is set to be spent every week for the next 30 months as the projects near completion. The pipeline underwent a full environmental impact assessment prior to being granted planning permission in April 2013, and with 50% of the route passing through areas of outstanding natural beauty (AONB), impacts on local ecology have been carefully managed. Wessex Water's Programme Manager Drummond Modley surveying the pipeline route The eight-year programme of works, which has spanned two AMP periods, was started in 2010 and is on course to be fully commissioned by 2018. It comprises more than 50 individual projects, including more than 200km of new pipelines, 24 JAMES BROCKETT EDITOR WATER & WASTEWATER TREATMENT

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