At first glance, water may not seem a resource that needs ?saving? in this country or indeed be part of an environmental agenda at all. Yet, in the last few years, the rate we have increased our use of water in the UK has put massive pressure on resources.
On average we each use around 155 litres of water a day, 70% more than 30 years ago. That?s around 1600 pints of water a week each. It takes 120 kilowatt hours to supply this water and 100 kWh to treat the dirty water a family puts in to the sewers every year. When you include the heating of water, this means that 20-25% of a family?s total average energy consumption is used on water ? enough to boil a kettle continuously for more than two months. It also costs the average family ?236 a year for water and sewerage. By taking the opportunity to implement water-saving measures when refurbishing homes, you can pass on significant savings to residents, and also achieve huge environmental improvements.
Despite recent instances of flooding in parts of the UK, water shortages are likely to become more common, and just because areas flood does not mean there is too much water overall. We are experiencing unpredictable amounts of rainfall due to global warming. This means an excess of rain can cause problems in some areas, while in others, such as Essex, there is not enough water and it has to be imported. Where flooding does occur, it is often intensified as so many of our natural ways of dealing with run-off (porous soil, reed beds etc) have been built on and there is nowhere for the water to go.
These problems can be alleviated during refurbishments in several ways:
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Installing water-reducing appliances
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Advising people how to use this resource effectively
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Installing water-recycling units
Significant amounts of water can be saved by collecting rainwater, or re-using water (grey water). The two methods can also be combined.
Greywater recycling
Grey-water recycling is when water used in the bath or by the washing machine is collected and re-used (usually for flushing the toilet). The daily amount used by these is about the same as the amount needed to flush the WC , and estimates on how much water could be saved through grey-water recycling range from 20-40%.
The waste water is collected and stored in a tank before being cleaned or filtered (or both) and made available for re-use for flushing the toilet, washing the car, or in the garden.
It is important that the water is adequately cleaned and only used for non-potable purposes.
Rainwater recycling
There are three types of rainwater recycling:
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Through the use of a water butt (see relevant section)
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Collecting the rainwater in a tank and using it to flush the toilet
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Installing a bigger collector and filtering the water for all domestic uses including drinking.
Collecting rainwater for flushing the toilet requires a tank of around 2m3, which collects water from the roof. A larger tank in a relatively rainy area could meet the needs of WC flushing, washing-machine and other uses? cutting water use by around 50%.
Water for such purposes (ie non-potable) has received certification by the Environment Agency.28
House type specific information: Underground storage tanks are commonly used to store rainwater. These must be made of concrete if the area where they are being installed has a high water table, otherwise flooding could occur and cause the tank to float out of the ground. Concrete is also a better option if the installation site is trafficked, eg in a driveway. Otherwise, a commonly used container is an old orange juice storage tank. Tanks range in size, but vary from the space-saving wall-mounted variety which has a capacity of 100 litres. This could be a good choice if there are space limitations on the house type or if a single system is being installed in a multi-occupancy flat where many flats are owner-occupied.
All rainwater-harvesting systems require pumps to transfer the water from storage tanks to the point of use.
For information on how best to commuincate ways to save water to residents click here.
