Could we use grey water to water fruit trees and crops?

04 March 2012


Is it safe to use grey water, water from the sink or from the shower et cetera, to water things like fruit trees or crops in your garden?


David - Yes. I think I would be perfectly happy to water my flowerbeds with gray water but I think I would be just a little bit cautious about watering fruit or vegetables that you were going to eat, just as a precautionary measure.

Ben - So what sorts of problems could you actually build up in there? Is it going to fill up with pathogenic bacteria or is it purely just a case of, "We know it's been used, we know it's got the chemicals in it from say, your shampoo, and they may impact on the soil quality".

David - It's both of those. I mean, there's the shampoo chemicals that might be taken up by the plant and certainly, even though this grey water comes from maybe the sink, it can also come from the shower and the bath. That can also have pathogenic bacteria in it. Ben - He also mentions another one which is the runoff the drip collected from an air-conditioning unit. Now air-conditioning, essentially the water that comes out, is distilled water. Is that likely to be a problem? Presumably, it's going to be pure and clean, and really healthy water, but is it an issue to be putting distilled water on our plants?

David - No, I don't think that's an issue but I would just be slightly cautious with air-conditioning units of any type because of the issue of legionella which can cause Legionnaires' disease in very extreme circumstances. Now I'm not suggesting it would cause a problem in this case, but I would be cautious with that water.

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