Grey water is water from your bathroom sinks, showers, tubs, and washing machines. It is not water that has come into contact with faeces, either from the toilet or from washing nappies.
Grey water may contain traces of dirt, food, grease, hair, and certain household cleaning products. While grey water may look “dirty,” it is a safe and even beneficial source of irrigation water in a yard. If released into rivers, lakes, or estuaries, the nutrients in grey water become pollutants, but to plants, they are valuable fertilizer. Use grey water to water grass, ornamental plants or fruit trees. Grey water can be used directly on vegetables as long as it doesn't touch edible parts of the plants.
In any grey water system, it is essential to put nothing toxic down the drain--no bleach, no dye, no bath salts, no cleanser, no shampoo with unpronounceable ingredients, and no products containing boron, which is toxic to plants. It is crucial to use all-natural, biodegradable soaps whose ingredients do not harm plants. Most powdered detergent, and some liquid detergent, is sodium based, but sodium can keep seeds from sprouting and destroy the structure of clay soils.
Grey water is different from fresh water and requires different guidelines for it to be reused