What Is Greywater (Or Graywater)?
October 3, 2007 · Written by Joel
According to our Green Glossary, graywater/greywater is:
“waste water that does not contain sewage or fecal contamination (such as from the shower) and can be reused for irrigation after filtration.”
Graywater Central, from Oasis Design, defines it in a slightly different manner:
“Any water that has been used in the home, except water from toilets, is called graywater. Dish, shower, sink, and laundry water comprise 50-80% of residential waste water. This may be reused for other purposes, especially landscape irrigation.”

As part of our 100 ways to save the planet, we recommend the re-use of water, but what are the benefits of using graywater? Again, Graywater Central lists a few:
- Lower fresh water use
- Less strain on failing septic tank or treatment plant
- Graywater treatment in topsoil is highly effective
- Ability to build in areas unsuitable for conventional treatment
- Less energy and chemical use
- Groundwater recharge
- Plant growth
- Reclamation of otherwise wasted nutrients
Greywater.com is another great source of information that provides step-by-step information on how to set up an irrigation system, how much water you could save, what to do about pollutants and so on. Do you have a greywater system?
[Picture via Greywater.com]






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[...] Greywater - waste water that does not contain sewage or fecal contamination (such as from the shower) and can be reused for irrigation after filtration. Read more about greywater here. [...]