A friend is doing some remodeling in his house and he realized that he could easily redirect and store some of the greywater from the kitchen and bathroom to the garden. Either using it immediately or storing it for later use. Can this water be used directly or does it need some filtering?

  • I would not use grey water for my garden unless I absolutely had to. To be able to do this responsibly you'd need MSGS sheets on every product you put down that drain. Naw. Plants need the best we humans can provide and grey water is not at all a good idea.
    – stormy
    Commented Aug 28, 2017 at 20:10
  • Check your local codes concerning the use of grey water. In Florida grey water can only be used to flush toilets and urinals. edis.ifas.ufl.edu/m/#publication?id=AE453 Commented Aug 28, 2017 at 22:47

2 Answers 2


You can use grey water on the garden, but storing it is not a good idea without strong chemical treatments. It contains bacteria, so if you're going to use it, it needs to be immediate. There are lots of Q & As on this subject on the site already, but more information on why it isn't particularly environmentally friendly to store grey water here http://info.cat.org.uk/questions/water-and-sewage/can-i-store-and-use-grey-water-my-bathroom-and-sinks/


Though Bamboo is correct that graywater storage can become odiferous and messy, that is not the end of the story. There are underground storage systems for graywater and in ground systems that have plant treating the water and so that what you use in the garden is not sludge. Your system just needs to remove nitrogen fast enough before the bacteria get at it. The problem with these systems is that the usually the metabolic of the cleaning plants can't keep up with the supply once winter hits; so you end up with a mixed system using sewage system in winter and graywater system solution for the rest of year.

Local and state/provincial governments often don't have statutes to deal with graywater, but you should poke around for laws in your area, I advise you to do this on the quiet. All statutes are online typically so research should be easy and private.

I have seen graywater systems in the Yucatan that were marvelous, but they have warm weather all year around. Here in Massachusets, there is a green house based sewage based system that is fascinating and is used in rest stops in Vermont and by corporations. A graywater system simply needs to remove

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