You wouldn’t think it at first glance, but London is a ‘water-stressed’ city. According to the UK Environmental Agency, with an ever-growing population, climate change and occasional ‘drought conditions’ (yes, they can happen in the UK), the capital is often short on drinking water. However, there is now a solution, and it’s one generally favored by more arid countries than old, wet Blighty – a desalination plant. Opening this week, the Thames Gateway Water Treatment Works will, if called upon, convert saltwater from the Thames into drinking water. It will only be used in times when water production falls to a certain level during ‘hotter-than-usual’ months, but when fired up it will be capable of producing around 140 million liters a day – enough water for 1 million people.
Operated by Thames Water, the East London-situated plant has cost £270 million but will utilise renewable energy to power itself. Using a biodiesel made from used cooking oil, the plant will, in the words of Thames Water, provide “much-needed backup for the seriously water-stressed capital in the event of drought conditions.”
Speaking at the plant’s opening, Thames Water chief executive Martin Baggs said, “The 2005 to 2006 drought was too close for comfort, with only a very wet May saving the day, and we never want a repeat of that . . . It highlighted what we already knew: additional water sources are needed, as well as a lot more work on reducing leakage, to be sure we have sufficient supplies in the long term.”
In terms of how the plant actually works, the Thames Gateway Water Treatment Works will utilize a commonly-used desalination process known as reverse osmosis, which forces salty water through extremely fine membranes. It is however quite a ‘power-hungry’ method, and as such it will use about twice as much energy as a conventional water treatment plant.
Thames Water said the Gateway plant will significantly improve on one- or two-stage systems by employing a four-stage reverse osmosis system that converts about 85 percent of the saltwater into drinkable water. According to government officials, London is expected to see an additional 700,000 people move in by 2021, putting a massive strain on the city’s resources. Coupled with an increase in single-person households and, ironically, a lower rate of rainfall than the rest of the country, and it appears London has been forced to implement technologies usually found in the desert.