About Grey Water Systems
Grey water is generally thought of as any water derived from domestic processes such as washing, bathing or kitchen use. For anyone thinking of getting a composting toilet, due consideration should be given to the re-use of grey water.
Since grey water has not been overly contaminated by bum biscuits or yellow cordial, it is relatively safe to use in the garden. I use the term “relatively” in a meaningful way. It all depends on what you use in your house and what is washed down the drain, and to some extent, how long and under what conditions grey water is stored and treated prior to use. Different end uses require different water quality standards so some form of physical or biological treatment is often required in order to re-use water for higher end uses such as clothes washing, toilet flushing etc. There are plenty of ways to use grey water. One of the most common is to run it out via a grease trap and a hose directly onto garden beds. This has some shortfalls including creating hydrophilic soil by applying too much soap (sodium) to soil particles.