Using waste water

by Anonymous

Thanks for all the info! I had a quick question. I was planning to reuse grey water from my house (washing machine, shower, basin) to water my garden and use in the flush tanks.

We use organic soaps, so not too much of the chemical stuff gets in the water, except for the occasional shampoos.

Does it need to be treated/filtered before being used for these purposes?


My first thought was that for garden use, the pH of the gray water (with soap residue and so forth) may not be optimal.
However, I really did not know the answer to your question, so I did a little research.

First, one thing caught my attention from the Oregon state website regarding water conservation:

“Gray water will turn into black water within 24 hours if it is stored and not properly treated. Oregon law does not currently allow wastewater from kitchen sinks and dishwashers, which may contain high amounts of salts, fats, oils, grease, food particles, and corrosive detergents, to be used in water conservation systems.”

With a little more research from several sources, I found consistently that any wastewater from the shower, bathtub, washing machine, and bathroom sink should be collected and drained into a holding or storage tank, where it is filtered and disinfected.

Even though you are using mostly organic personal care and cleaning products, I think the organic matter in the waste water is also problematic, especially if the “gray water will turn into black water within 24 hrs if not treated.”

I saw comments from DIY users online to this effect also. One guy said the odor in the flush tank where he was using gray water was really bad after a day or so, and he was looking for a way to treat it naturally to get rid of the odor.

Apparently there is a disinfectant made with citric acid crystals that is used in RV tanks. So that might be an option if you want to look into that.

Obviously this is not my area of expertise but, for what it’s worth, I would not use the gray water unless it was treated/filtered.


Oregon Smart Guide: Water Conservation Systems

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