RAINWATER RECYCLING OFFERS AN ATTRACTIVE SOLUTION AS WATER CRISIS DEEPENS by Gerry Quinn, Product Manager for Envireau rainwater recycling equipment, which is manufactured by Klargester

In years gone by, it was relatively cheap and convenient to use treated drinking water for everything from flushing the toilet and running the washing machine to cleaning the car and watering the garden.

But a shortage of rainfall in recent years has made water a precious commodity, with some experts fearing demand could outstrip supply by up to 10 per cent by the end of the decade if we do not use it more sparingly.

The situation has been exacerbated recently by an exceptionally dry winter in some parts of the UK, which has sparked fears that the country could be facing its worst drought in a century unless rainfall dramatically increases.

A raft of initiatives, which include bans on non-essential watering and compulsory water metering for existing homes, are currently being proposed by water companies desperate to conserve resources in some of the worst affected areas.

Such measures will no doubt prove to be effective in making people think about how much water they use, thereby reducing consumption. However, another simple yet highly effective solution, which is beginning to grow in popularity in the UK, is rainwater recycling.

Much of the water that we use does not need to be of drinking quality. In fact, studies show that 55 per cent of domestic treated water could be substituted for rainwater, while 85 per cent of water used for commerce and industry does not need to be of drinking standard.

With treated water in such short supply, it makes sense to look to other sources for many of our everyday needs. Rainwater can be safely used for a variety of non-potable purposes in and around the home, including flushing toilets, running washing machines, cleaning cars and watering the garden.

Rainwater can also be invaluable for industry - one of the largest water consumers -where it can be used for factory cooling systems, and cleaning vehicles and equipment, for instance.

Recycled rainwater can even be brought up to drinking standard, if required, by using an Ultra-violet Disinfection Unit. This can be particularly useful for very remote areas which do not have mains water and rely on natural sources.

All rainwater recycling systems operate using typical roof drainage layouts. This means rainwater runs down the roof and into the guttering and fall pipes in the normal way before passing through a filter, which removes the leaves and grit. The rainwater is then stored in an underground tank containing a pump and filter.

The Klargester Envireau gravity system pumps water to a dedicated header tank in the loft space via an inline filter, which further cleanses the water. One of the great advantages of this system is that the header tank also has a mains water supply, so if the pump was unable to work due to a power cut, or the underground tank became empty, the system would automatically switch to mains water.

Klargester also manufactures another system that pumps rainwater direct from the underground tank to the appropriate household appliance.

Rainwater management systems such as these have been developed to be as user- friendly as possible and are simple to install, maintain and operate. In addition to helping to preserve a valuable resource, they also make good sense economically for people building new homes, since all new domestic and commercial properties in the UK are automatically connected to water meters.

A full rainwater recycling tank for a two-storey house with a 100m² roof could provide enough water for 200 toilet flushes, 30 full washing machine cycles and 12 car washes. A 100m² roof area can yield up to 120m³ of rainwater per year with a value of up to £2.56m³, giving an annual saving of £256 for a property on a water meter.

Another key advantage is that when the rainwater has been recycled, it passes through the foul system, rather than the storm drains, meaning that it poses no flood risk. Consequently, rainwater recycling systems are becoming a necessity for gaining planning permission in some areas of the UK that could be at risk of flooding, particularly where regulators insist that surface run-off must be no greater than if the land was used for agricultural purposes.

Rainwater recycling systems, which cannot usually be retro-fitted, are currently used in about one per cent of new developments in the UK, although this figure is expected to increase.

The systems were introduced to the UK only about eight years ago, but they have long been popular abroad. For example, they have been used for about 20 years in Germany, which does not have as much rainfall as the UK and is more reliant on groundwater.

Water shortages could have immense ramifications on a global as well as national scale. While the current shortages in the UK have raised fears of standpipes and supply cuts, limited water resources are becoming such a problem throughout the world that they are likely to be a source of international conflict in the future.

Rainwater recycling offers a simple, yet very effective means of preserving one of our most precious resources. As the water crisis deepens, we expect that it will play a vital role in helping to offset some of the problems caused by climate change.

Click here to download this press release