Modern Building Services

10 MODERN BUILDING SERVICES SEPTEMBER 2022 FEATURE PIPED SERVICES, PUMPS ANDWATER Can greywater recycling snatch life from the “Jaws of death” ? Sam Burgess , Water Reuse Manager at SDS says wasting water should be as socially unacceptable as “blowing smoke in the face of a baby”. That was the urgent appeal of Environment Agency Chief Executive Sir James Bevan in his famous “Jaws of death” speech back in 2019 1 . D espite that warning, England is still on a trajectory to start running out of treated mains water within 20 years. By 2050, the deficit is predicted to reach 3,500 million litres per day. Yet up to 60% of the drinking water supplied to commercial buildings, such as office blocks or hotels, is used where high-level treatment is simply not needed. Water UK – the body that represents Water Companies – has told the Government that a maximum 2050 target of 85 litres per person per day is feasible by 2050 2 . But how? Current planning regulations for England and Wales require a 125 litres per person daily limit for new developments, but Environment Secretary George Eustice has said he will encourage local authorities in the 14 most water-stressed Water Company regions to adopt an optional 110 litres per person daily 3 . This lower limit is already applied through The London Plan, leading to a much greater take-up of grey water schemes in new buildings in the capital. Better understanding and evidence of what grey water systems can achieve is, therefore, essential to driving informed policy decision-making, as well as encouraging adoption by architects, engineers, developers, and planners. Recent innovations in grey water recycling technologies promise to help meet these challenges. Grey water is usually wastewater harvested from baths, showers, and hand basins, which is filtered, treated, and then reused for non-drinking purposes such as toilet flushing, laundry, or garden irrigation. On-demand technology Advances in grey water technology using a new ‘on-demand’ process are providing a more responsive and cost-efficient process that makes the return on Investment more favourable. The new technology is also offering early adopters of grey water systems the opportunity to replace legacy high-maintenance Membrane Bioreactor (MBR) systems with more efficient and cost-effective treatment systems. SDS’s Grey Water Recycling systems are supplied as package treatment plants. Larger scale systems use a sequence of leading-edge disk filtration and ultrafiltration processes. In one of the first residential installations in the UK, this system was successfully installed in a high-class apartment development in Holland Park, Kensington, one of London’s most exclusive addresses. Despite the extremely high-specification bathrooms, the building’s water usage was calculated to reduce by at least 15% to an average of 90 litres per person per day, more than meeting the planning requirements. The technology is also being adopted in new commercial and mixed-use developments in London; and seeing take-up in hotels both in, and outside of, the capital. Grey water systems are of course best suited for installation in new buildings because a separate network of additional pipework is required through the building.