Rainwater Harvesting and Greywater Recycling

The UK is currently debating the best approaches to tackle what appears to be two contradictory water-related environmental issues. It is suggested that water supplies are under either moderate or serious levels of stress in most of England south of the Humber, but clearly visible changes in our climate are resulting in heavier rainfall events with more frequent incidences of severe flooding.

Existing water infrastructure is stretched and would struggle to provide the additional water needs for proposed future developments and handle the extra drainage from the more severe storm events. Rainwater harvesting (RWH) and greywater recycling (GWR) are two technologies that are relatively new to the UK and which have the potential to reduce both water demand and drainage.

The government has recognised that action must be taken and one of its approaches focuses on the Code for Sustainable Homes, currently mandatory for public sector housing. The national average per capita water consumption is currently 150 litres/day; levels 3 and 4 of the Code require that this be reduced by 30%. Levels 5 and 6 go further and demand a 47% reduction; achieving this latter figure will only be possible with some form of water recycling.

There is more to water recycling that just saving water, however. The water companies currently use around 3% of the country's electricity and this is associated with a similar amount of greenhouse gas emissions. Much of this energy is used simply for moving water, from source to treatment to supply and then back as wastewater for further treatment. Any reduction in water demand therefore carries with it savings in both energy and GHG emissions.

RWH and GWR have been widely used overseas but are still a young industry in the UK. Potentially, the technologies promise a lot but there are a number of questions that must be answered if the technological promise is to be delivered. In view of the proposed future house building programme and requirement for these developments to be carbon neutral, the market potential of water recycling technology in the UK is large.

Austin Court, the Birmingham home of the Institution of Engineering & Technology (IET), is 5 minutes from the major motorway networks. If you are arriving by train, the venue is an easy 15 minute walk from Birmingham New Street station.

View the full programme see www.aquaenviro.co.uk. Book online or contact Sally Wright (sallywright@aquaenviro.co.uk) for exhibition space. 

Here is a great site on setting up a rainwater system inexpensively: http://www.rainharvester.blogspot.com wonder - 12/11/2009 - 03:42