Water and Effluent Treatment Magazine
Issue link: https://read.utilityweek.co.uk/i/805302
Grid scheme nears finish line • Wessex Water's new water supply grid project is in its final year of construction. Maureen Gaines has been catching up on its progress. region is classed as an area of outstanding natural beauty, and also rich with archaeology. "We have hugely sensitive settings and anything that was built was made to look like existing farm structures to fit into those settings," says Modley, who works for Wessex Water's in-house construction and engineering arm WECS. During the course of the project, the delivery team has also liaised with five planning authorities, and more than 300 landowners and land tenants. It also has had to overcome the unexpected including phos- phorus bombs from WWII, dormice, the relocation of barn owls, historic burials – "and the British Army getting in the way on Salisbury Plain". Pipeline routes were kept away from communities and, says Modley. "Some weren't really aware... They thought we were building roads, actually." TECHKNOW • A new OptiMISER control system has been developed to manage and optimise the grid • Open-cut techniques have been used • Pipeline material varies between, ductile iron, polyethylene and steel NEED TO KNOW 1 The grid will enable Wessex Water to redistribute surplus water to where it is needed 2 The grid satisfies four outcomes – supply resilience, drinking water quality, deliver to customers, and improve watercourse ecology 3 Wessex Water supplies about 350Ml of potable water across a patch covering 7,500km 3 including Dorset, Wiltshire and parts of Gloucestershire THE VERDICT "It's relentlous and therefore the team needs to be entirele focused to make sure it happens..." Drummond Modley ONSITE WATER SuPPly About 200km of pipelines have been laid during the eight-year project W alking into the home of civil engineering – One Great George Street, London – and its impressive decor it seems a fitting venue in which to hear how Wessex Water is progressing with its mammoth water supply grid project. Engineers gathered at the venue, which is the HQ for the Instituti0n of Civil Engineers, one evening in March to hear grid programme manager Drummond Modley give an insight into the scheme. The water supply grid is the biggest and most complex project that Wessex Water has ever done. It is the company's answer to meeting future demand and ensuring security of supply to customers as the grid will enable water to be moved to areas where it is needed. Outcomes The £230M, eight-year scheme is due to be completed in a year's time and will have involved 50 individual projects including the construction of 200km of pipelines, building or refurbishing 24 pumping stations, and establishing 12 storage tanks. The grid will satisfy four of Wessex Water's nine outcomes: • Delivering to customers • Supply resilience • Drinking water quality • Ensuring watercourses are in good ecological condition Establishing the grid has been no mean feat for Modley and his team. For instance, around 50% of Wessex Water's Modley says that over the past four years, about £1M has been spent a week on construction while the spend for the final year is reducing to between £2.5M and £3M a month. "It's relentless and therefore the team needs to be entirely focused to make sure it happens because there's not a lot of time and an awful lot of work to be done," says Modley. One of the things about the integrated grid is that Wessex Water has been able maximise delivery without having to build new treatment works or develop new water resources. Water resources Existing facilities have been upgraded for iron and nitrate removal, which Modley says is "fantastic from a sustainability point of view" because customers are getting what they need without new water resources having to be built. The grid has to be managed and Servelec's OptiMISER control system manages and optimises the transfer of water. The so›ware is enabling Wessex Water to move water in numerous directions at any one point in time. It has also given the company's control room total visibility. Modley concludes: "This is an important piece of new infrastrucure in the West Country. It's an example of trying to use our existing infrastructure and very much in line with using the three pillars of sustainability. To achieve this digital technology has been needed – it couldn't have been done using slide rules or computers from ten years' ago." Drummond Modley pROjECT spECs • Establish a water supply grid by 2018 • Construct 200km of new pipelines • Construct 24 new or refurbished pumping stations and 12 new storage tanks 10 WET NEWs APRIl 2017