Water Technology That Makes A Splash

FOR an island race, the British seem unusually pre-occupied with the possibility of running out of water. But as United Kingdom scientists add their weight to concerns about climate change and dwindling global water supplies, water companies are under scrutiny and under pressure to deliver technologies and strategies that will impress a demanding and increasingly environmentally-aware domestic market.

The UK government has stressed the need for a united approach. As former Environment Minister Elliott Morley (now responsible for implementing policies on climate change agreed at the G8 summit 2005) said: “There is no one solution to this complex challenge, and in a changing environment we need a joined-up approach if we are to protect the long-term sustainability of supply … working on a number of levels together to reduce leakage, improve technology, minimise waste.”

How is this political will and public desire translating itself into practice? In 2003, the Water Technology List was published as part of a government drive to support business investment in environmental technologies under the Green Technology Challenge. This allowed for the introduction of tax incentives to companies investing in green products.

The list is regularly updated to include the best in water saving and water-quality improving products that the UK has to offer.

These include:
* efficient toilets with low-rate and dual-flushing equipment;
* “cleaning-in-place” equipment - such as the i-pipe by Manchester-based company Kaiko - that works by measuring electrical flow in liquids that occur as their formulation changes, and therefore constantly monitors water quality;
* efficient showers such as low-flow showerheads as produced by companies such as Mira;
* efficient taps (faucets) such as electromagnetically operated and self-closing taps as produced by Doncaster company Pegler;
* flow controllers and leakage-detection equipment such as the PC-based meter and leak alarm system produced by Somerset company Elimileak;
* meters and monitoring equipment, rainwater harvesting equipment such as the disinfection unit offered by Nottingham-based company Stormsaver;
* efficient membrane filtration systems such as micro-filters that offer high-level purification allowing wastewater to be recovered and reused.

Many groups exist to promote efficient water use, such as Waterwise (www.waterwise.org.uk), an independent organisation set up in 2005 in the UK. The group receives some funding from the industry and which it aims to match through joint partnerships with other non-governmental organisations, business and government.

Waterwise director Jacob Tompkins, said: “The UK has an impressive record of driving and responding to market demand, and droughts in the UK in recent years have led to innovations in water-efficient technologies for home and business. The UK’s water-efficient technologies would transfer usefully to markets where water is already scarce or threatens to be in the future.”

British Water (www.britishwater.co.uk) was formed from the merger of two trade organisations in 1993 and today it is the voice of the UK water industry. Its technical director, Dr Ian Pallett, said that a research and innovation working group is being set up specifically to provide a route for member companies to highlight innovative technologies in the sector.

And he was keen to point out the work being done by groups such as Water Innovate, a spin-out company of Cranfield University, southern England. A range of exciting technologies being developed by Water Innovate include ZR-Coag, a high-performance chemical additive for water and wastewater treatment. Using zirconium compounds, ZR-Coag enables high-efficiency coagulation of drinkable supplies and waste-treatment effluents.

Other developments include N-Tox, a toxicity monitoring system that provides early warning of sludge treatment failure. The product detects nitrous oxide, a harmful greenhouse gas with global warming potential almost 300 times that of carbon dioxide.

Water Innovate has also produced ODOURsim, a powerful and revolutionary Windows-based software package specifically developed for the modelling and simulation of odours generated in municipal and industrial wastewater treatment plants. The software provides an essential tool to help develop
odour-management strategies.

On the domestic front, companies such as Elemental Solutions
(www.elementalsolutions.co.uk) are busy developing products that have grown directly from their independent research into sustainable water management. Such products include the Airflush urinal that is waterless; the ES4 WC that uses 4.5 litres to flush as opposed to an average nine litres for traditional toilets; and the Compus dry toilet that composts human waste.

Meanwhile, many supply companies are actively investigating ways of making new homes use less water. For example, Essex & Suffolk Water, in partnership with other interested parties, has funded a project to trial water-efficiency measures and grey water recycling in 37 new homes in Heybridge, Essex.

Twelve test homes were fitted with six-litre flush toilets, low-volume flow showers, spray taps and low-capacity baths and then compared for efficiency against 12 control houses using standard appliances. The average amount used per person per day was 97 litres in the water-efficient homes compared with 102 litres in the control homes – a saving of five per cent.

Desalination plants are under investigation by two UK companies, South East Water and Thames Water that between them meet the needs of the most densely packed and water-needy parts of the country.

Desalination has its critics who say the process requires too much energy but Thames Water claims that it is the only way to provide London with the extra water the capital needs, quickly enough and at an acceptable cost. Its environment director, Richard Aylard, said: “It takes the same energy to produce only two litres of bottled water as the desalination plant would need to supply a family of four for a day. The use of the plant would be regulated by the Environment Agency and we would only turn to it when we need to.”

The Thames Water proposal would supply Londoners with 140 litres a day, drawing supplies from the tidal stretch of the River Thames where water is about one third as salty as the sea. It would be stored in a buffer tank before entering the treatment process where large, small and finer particles would be removed.

The water would be pushed under high pressure through very fine membranes that hold back salt and impurities. Minerals would then be added, the water would be disinfected and then begin its journey to customers’ homes.

Thames Water is also investing in addressing water lost through leakage and has already replaced 400km (250 miles) of London’s water mains since 2002 in the first systematic programme of pipe renewal in the capital since Victorian times. It plans to renew a further 1,370km (850 miles) of pipework by 2010 at a cost of 540 million pounds, and an additional 60 million pounds a year is being spent on locating and fixing leaks.

At Newhaven harbour in Sussex, South East Water has built a pilot desalination plant measuring 12 metres by 2.5m by 2.5m (the size of a cargo container) to conduct a trial into the technology. If approved, a full-scale plant would be contained in a building the size of a small warehouse and would be capable of producing up to 9.5 million litres a day. South East Water supplies 400 million litres a day, therefore the plant, if built, would supply just a small proportion of the area’s needs.

But South East Water intends the plant to run at full capacity only during long periods of dry weather when it would be blended with water from other sources and fed into the distribution system to reach those areas with shortages.

Transferring resources from an area of plenty to one of need is another approach being used by some collaborating companies. For example, construction is also well under way on a 25 million pounds project run jointly by Southern Water and South East Water that will transfer water from Kent to East Sussex where resources are already stretched.

A pipeline has been built to link Bewl reservoir, Kent, to Darwell reservoir, Sussex. A second pipe then runs from Darwell to South East Water’s treatment works at Ninfield, also Sussex. The scheme is designed to help secure supplies for customers in Sussex, especially during long, dry times.

Meanwhile, Southern Water has recently completed a micro-filtration plant that will improve water quality to the city of Southampton in southern England. The plant took two years to build at a cost of nine million pounds and includes latest mechanical and electrical equipment including millions of hollow micro-filters resembling fine porous straws to offer added protection to the quality of water.

Jon Crooke, its water operations manager, explained: “Water from underground at our treatment works in Otterbourne near Winchester is sucked from the outside to the inside of the fibres. This is designed to remove particles larger than one thousandth of a millimetre in diameter which cannot pass through the membrane.”

The same company is also helping to bring cleaner seas to the coastline at one of south-east England’s most popular stretches of beach at Margate and Broadstairs in Kent. Southern Water is spending 80 million pounds on a scheme to transfer wastewater from Margate and Broadstairs along one of a new 11km system of pipelines to a new treatment works that is being built as part of the project.

Up to 20 million litres of wastewater will be treated every day at the works where it will undergo a series of processes including disinfection by ultraviolet light. The treated wastewater will then be sent back to Margate via a parallel part of the pipeline system for release far out to sea.

Along with the engineering approach, the UK government and the water industry are also looking at simpler technologies such as water metering and water-awareness campaigns to do, perhaps, the hardest job of all: change consumer behaviour.