Grey water, black water – what’s the difference? Once you understand the differences between grey water and black water, you will be able to take advantage of recycling water around your property which will lower your water bills and increase your environmental awareness.

The water to flush your toilet and any kitchen waste water, which is full of fats, additives and chemicals, is known as black water. If you wish to recycle this water, you will need to install a full sewage treatment facility which is expensive for an individual home, especially as it needs to be extremely effective to turn the water back to an acceptable level for gardening or car washing.


The water that is easily recycled around your property is called grey water. This is the water that flows from your bath or shower, wash basins in your bathroom and also from the washing machine in your laundry. Although there will be chemicals in some of this water, it can be treated relatively easily and returned to use around your home.

Is grey water clean?

Some of your grey water may include minute traces of food and grease, hair and dirt particles and chemicals from cleaning products you have used around your home. It might look slightly sullied and you certainly wouldn’t want to drink it, but it can prove to be a great source of water for irrigation around your garden.

Where grey water isn’t fully treated, it should not be released into rivers or lakes because the grey water may include nutrients that would become pollutants in vast water systems which may be dangerous to the fish and other livestock in the river or lake. For plants, however, grey water is a particularly valuable fertilizer.

The benefits of using grey water

Apart from the financial savings made by reducing your water bill because you will be recycling water around your garden, by reusing all of your grey water, you will ensure that it doesn’t reach either the sewage system or your own personal septic system. This means that fewer pollutants will be entering the water systems run by your local water company.

By continuing to reuse grey water, you will complete the natural water cycle by returning it to your garden.

You wouldn’t want to have to catch water from your shower in 2 liter soda bottles, transfer the water into a watering can and then use it around your garden. The best laid plans will involve asking your finest environmental plumber to visit your home to see how water can be redirected from areas like showers and sinks in your bathroom direct to a water reservoir either in your garden or under your home. By using solar powered energy, the water can be pumped to a hosepipe so you can use it around the garden.

You will need to re-educate your family to make sure that you don’t put any bleach, dye, or any products which include boron (toxic to plants) into your grey water system. Reading every package to find out what is in your shampoo and soaps may change what you buy.

Grey water is best used as fresh as possible as the nutrients in the water will begin to break down if it stands for longer than 36 hours. If you can avoid adding a solar powered pump and filters to improve the water quality and for easy accessibility, your system for reusing water will be almost maintenance free.

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Get more tips on water and the environment from Damien Higgins of Eden Springs.