Rainwater and greywater use in buildings. Decision-making for water conservation

The government, water regulators and water supply undertakers are all encouraging the adoption of water conservation measures. One component of these measures is to use rainwater and greywater (water from wash basins, baths, and showers) as a source of water to reduce the reliance upon the mains water supply. There has been relatively little guidance on how separate or combined rainwater and greywater systems may provide safe water to buildings. This guide provides a background to the use of rainwater and greywater and identifies the barriers and benefits of this type of water use and recycling. It discusses the issues surrounding rainwater and greywater use, including regulation, water quality, hazards of operation, economics, design and suitability of application. The document is aimed at water utilities, local authorities, and environmental regulators. In addition, the document is aimed at private individuals and house builders with an interest in conserving water resources.