Lyall Bills & Young’s secluded water recycling plant in the Olympic Park sets the standard for similar utilities, says Amanda Birch
Just past the manicured lawns surrounding the Olympic Stadium in London’s Stratford is a large sign to the ‘Old Ford Water Recycling Plant’. Pass through the gates into a woodland setting and it’s like entering another world. Mature trees and wild grasses grow unhindered, bees buzz and newts bob under the water of a small pond. Instead of the frenetic noise of the last-minute preparations for the Olympic and Paralympic Games, bird song pierces the air in this enclave, which retains the ambience of pre-Olympic east London. The contrast between the controlled and pristine appearance of the Olympic Park and this wild idyll is dramatic.
A simple, rectilinear building sits to one side of this 1.66ha serene oasis. Clad in larch and gabion baskets, this is a building designed to blend in with its woodland location. Its use isn’t immediately apparent but the presence of two large circular water tanks and Cor-ten steel loading bay doors suggest that this is an industrial facility.
The Old Ford Water Recycling Plant is the largest community wastewater recycling facility in the UK. The plant, which went on stream on 1 April, takes raw sewage from the Northern Outfall Sewer and cleans it through a multi-layered process before the water is fed into a non-potable network in the Olympic Park. This supply will flush the toilets of the Media Centre, the Handball Arena and Eton Manor and irrigate the plants around the main stadium as well as numerous green spaces in the park.
Jointly funded by the Olympic Delivery Authority and Thames Water, the Old Ford Water Recycling Plant was a pilot research project set up as part of the ODA’s sustainable water strategy, which had a target of reducing potable water use in the Park by 40 per cent. But this project is more than a vehicle for the ODA to meet its sustainability targets during the Games and into the Olympic Park’s legacy. It is also a platform for detailed research into reclaimed water that will be of national interest and will contribute to a growing body of work on this subject.
Designed by Lyall Bills & Young Architects, the recycling plant is one of four infrastructure buildings by the practice in the vicinity of the Olympic Park (AJ 12.08.10). One of these, the Old Ford Ground Water Pumping >> Station is on the same site: a collection of five striking cubes with a similar palette of materials. Cor-ten steel, the cladding material for the cubes, is referenced on the water recycling plant’s doors and both facilities have green roofs to encourage biodiversity – a given for all new infrastructure buildings on the Olympic Park.
The architects worked hard to design a water recycling plant that was sympathetic to its surroundings. The Old Ford location is a Site of Nature Conservation Importance and the land is leased to the London Wildlife Trust. To minimise its visual impact, the 45m x 13m building is largely single-storey. The exception is a double-height 10m-tall section at the eastern end or ‘dirty’ zone of the linear water treatment process (see page 79), to allow for emergency access and a 15m-tall odour stack, the verticality of the flue counterbalancing the horizontal building. The ‘clean’ zone is at the west end of the building and houses the office, visitors’ area and toilets. The height of the building therefore responds to the processes within.
The cladding materials were carefully considered. A robust material was needed for the base to cope with the risk of flooding and impact. As an alternative to concrete, gabion baskets were employed – a treatment that provides a ready-made habitat for plants and wildlife. Crushed Somerset stone was used in the gabions as it was considered to be a more refined finish by the planners, despite the ODA’s aim that material from the Olympic Park site, in this case crushed concrete, should be re-used where possible. At the eastern end of the building, the gabion baskets extend half-way up the building wrapping around to the southern elevation, where they drop to a low plinth before the building becomes single-storey. The north elevation follows a similar pattern.
The cladding of the upper section is larch boarding, which blends in with the mature trees encircling the building. Over time, the larch will weather to silver and merge with the grey gabion baskets below. This is not a building for people to look out of. Daylight is needed, but with minimal glare and solar gain. Rooflights were avoided for maintenance reasons. Instead, discreet, narrow windows are deployed where machinery isn’t located.
This is a carefully considered facility that will age gracefully. As the green roof matures, the materials fade and the trees and grasses grow even taller and wilder, this building will merge into the landscape, as intended.
The Old Ford Water Recycling Plant could easily have been just another brick utility shed with a tin roof. But, in response to the Olympic Delivery Authority’s aspiration for design quality, championed by Kay Hughes, the architects have delivered more than that through careful consideration of massing and materials. Whether future infrastructure buildings will employ a similar high quality is debatable. But if heavy technology continues to be brought back to dense areas near to where people live, then the stakes are raised. Taking a cue from the Victorians,more infrastructure buildings which celebrate their technologies and cloak them in materials sympathetic to their environs would be welcome.
AJ Buildings Library
See full project data, photographs and drawings for the Old Ford Water Recycling Plant
How it works
Unique on this scale in the UK, the Old Ford Water Recycling Plant houses an innovative treatment process that produces 600,000 litres per day of reclaimed water for non-potable applications. With the exception of BedZED’s wastewater reclamation plant, there are currently no membrane bioreactors in the UK for urban reuse. However, the BedZED plant only treats and recycles domestic sewage for toilet flushing. The Old Ford plant is 20 times larger and is linked to an extensive metered reuse network on the Olympic Park with multiple end-users.
Raw sewage passes into two underground septic tanks located outside the building, which provide flow equalisation and primary settling. The effluent then passes through a 1mm screen inside the facility to remove small fibres and hair that could clog the membranes. Influent is then treated by a membrane bioreactor (MBR) process, which combines biological treatment with a membrane filtration step. To ensure consistent reuse quality, the MBR product is further treated to remove any residual colour. Chlorine dosing ensures disinfection and suppresses bacterial re-growth in the distribution network. Finally, the reclaimed water flows into the outdoor larch-clad storage tank, from where it is pumped into a dedicated non-potable network when demand requires.
Future of the technology
After the Games, the London Legacy Development Corporation will operate the Park. Some venues will retain the reused water supply, while others will use the data generated by the Old Ford plant to determine whether they will utilise reclaimed water in the future for other purposes, such as cooling. Thames Water has a commitment to run the plant for seven years and will actively seek users for the water generated by the facility.
On-going research at the Old Ford plant will investigate process optimisation and energy minimisation, as well as support the development of standards and guidelines for water recycling systems. Also crucial will be gauging public perception about the use of recycled sewer water.
The majority of full-scale MBR plants for urban reuse are situated in the US and Japan, but their use is rapidly increasing in Europe, China and Australia.