Water & Wastewater Treatment Magazine
Issue link: https://fhpublishing.uberflip.com/i/1062770
ozone diffuser rods are being put in to replace diffuser domes, on the grounds that these have a reduced surface area and are easier to clean during the site's annual maintenance shutdown. Finally, the site's sludge treatment will be significantly enhanced, with a new blending tank, two thickening tanks and one tank for thickened sludge, all of which improve the quality of sludge and its reliability for being recycled to land. Treated water from Bray Keleher feeds the Surrey Hills service reservoir from where it goes into the mains. Since this reservoir is also fed by Egham Treatment Works, which is run by Affinity Water (with any plant shutdowns needing to be covered by the other), the two companies have maintained a constructive dialogue about the project. The project is currently on time and on budget. The construction phase is expected to be complete in March next year, with the expanded plant being operational by November; this would be well in time to meet the March 2020 deadline required to fulfil the terms of the abstraction licence from the Environment Agency. A diagram of the works, with the new sections highlighted in bright green Hundreds of precast panels have been used to assemble tanks and structures www.wwtonline.co.uk | WWT | JANUARY 2019 | 19 a high degree of collaboration was needed between client, contractors and the supply chain, explains Brian Steventon, project manager at South East Water. "The model [showing the 3D design] has been shared between all of the supply chain," says Steventon. "It's been interesting to see the interface between the designers and the manufacturers. For example, when the panels are laid out they might want to put the rebars [reinforcing bars] in certain locations, which might not work with where the pipes go through, and in some cases we've had to move a pipe, in other cases move a rebar. It's been quite a detailed and challenging phase, and there's been some lively discussions." The project is introducing some improvements to treatment processes and equipment. New baffles will be installed in the pre-ozonation tank to make this more efficient. The settlement phase deploys a recently developed innovative technology, DWI-accredited TUBEdek Lamella Separation Tubular Settlers, made by 2H Water Technologies. At the second ozonation stage (inter ozonation), • BRAY KELEHER IN NUMBERS £22M The cost of the project 2020 The year that the project will be completed 25,000 Tonnes of earthworks needed to prepare for the project 350 Precast panels are being used in construction 68 ML/day The new capacity of the plant • IN QUOTES "Using precast concrete means that you have fewer people working at height, you've got fewer li ing operations going on, and it shortens the preliminary time that people are on site physically building, so there's a good safety benefit." Desmond Brown, head of engineering, South East Water "The Bray Keleher project is a flagship scheme within South East Water's current AMP investment programme and we are proud to be playing a leading role. The project has been meticulously planned and the collaborative approach to working is paying dividends, with work on site progressing well, and the project is on track for completion in spring 2020." Tony Stanbridge, operations manager, nmcn