Water & Wastewater Treatment Magazine
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Anglian installs Europe's biggest ultrafiltration membrane An innovative filtration system is the centrepiece of a £36M project in Norwich for Anglian www.wwtonline.co.uk | WWT | MAY 2019 | 27 The Knowledge Innovation Zone A nglian Water has begun installing a state-of-the- art filtration system at its Water Treatment Works in Norwich as part of its £36mil- lion scheme to keep custom- ers' taps running for decades to come. The ultrafiltration mem- brane system at Heigham WTW will be the largest of its kind in Europe and work to in- stall its components will take place over the coming days. Work on the scheme began in 2017 and it makes up part of the half a billion pounds the water company is investing in the region between 2015 and 2020. The scheme will be completed later this year, and will supplement the existing treatment process. Every single day Anglian Water supplies millions of litres of water from the River Wensum to over a quarter of a million customers and busi- nesses that rely on it in and around Norwich. However the city is grow- ing. Norfolk is expected to be home to more than one million people by 2034, many of whom will choose to live in Norwich - one of the UK's fastest growing cities. This combined with being in one of the driest counties in the UK means investment is required to ensure there is a ready supply of water for people's daily lives and to power the economy. Anglian Water's investment will make sure the environment does not suffer as a result of this growth; ensuring levels of abstraction remain sustainable. Regan Harris from Anglian Water said: "Norwich is a rapidly growing, thriving city and a regional economic pow- erhouse. Water helps power that economy, so it's essential there's enough to go around but we also care for the envi- ronment and want to ensure we're protecting it." Historically, the Costessey Pits have been an important part of the water treatment process by providing natural storage for water from the Wensum prior to its treat- ment. This initial phase allows solids and sediment naturally occurring in the river to settle out from the water before it's pumped to the Heigham Water Treatment works for further treatment before entering supply. Parts of the River Wensum are designated Sites of Special Scientific Interest and Special Areas of Conservation. The Costessey Pits area specifically has a rich and diverse environ- ment that needs protecting. In the future, Anglian Water will not be able to take enough water from Costessey alone to support the needs of the growing population without having a detrimental impact on the environment. To protect the environment against this, more water will need to be taken further downstream in the Wensum - nearer Heigham Water Treatment Works itself. At Heigham, water flows are higher as the River Tud joins the River Wensum. These higher levels mean Anglian Water can take the water needed from the river without damaging the delicate ecosystem near Costessey. This hasn't been possible previ- ously because the water at this point in the river contained too much sediment to be treated without settling first; but the installation of the new filtration system will solve this problem and treat the water to the exceptional standards required. "We're planning decades into the future with this invest- ment, to make sure Norwich's water supplies are secure for years to come," Harris contin- ued. "Although fundamentally there is still the same finite volume of water to go around the Wensum and other rivers of Norfolk, we'll be preventing any extra stress on the ecosys- tem in the river in future."