Greywater is lightly contaminated waste water from the shower, bath and washbasin, but not from the toilet, which produces blackwater. After suitable treatment, greywater can be reused for purposes such as toilet flushing or garden watering, reducing the demand on the mains supply.
Characteristics
- Lightly polluted — contains soap, hair and skin particles but no sewage
- Distinct from blackwater — toilet waste is heavily contaminated and treated separately
- Reusable — after treatment it is suitable for non-drinking uses
- Water-saving — reuse cuts fresh-water consumption
Application
Sources of greywater
- Showers and baths
- Washbasins
- Sometimes washing machines
Reuse after treatment
- Toilet flushing — a common and effective reuse
- Garden and landscape watering
- Cleaning and irrigation where potable water is not required
Greywater systems collect, filter and store the water before it is pumped back for reuse, forming part of a sustainable building’s water strategy.
Related Terms
- Waste water
- Rainwater drainage
- Grey electricity
- Sustainable building
More guides and plans available at fredsdiyplans.com