Understanding greywater

Greywater is the wastewater from showers, baths, basins and washing machines.

It is safe to reuse around the home and garden when done properly and can be as simple as collecting water in a bucket from your basin and shower. Greywater doesn’t include water from the kitchen sink or from toilets, which is known as black water.

Minimising the impact of greywater

Greywater can contain disease-causing microorganisms, oils, detergents, salts and more from cleaning products. Switching to greywater-safe cleaning products can minimise the impact on your wastewater and the environment, especially if you are using it to water the garden.

How to collect greywater

Buckets or bowls

Collecting greywater from your shower, basin or washing machine is easy and accessible. This can be used for watering plants. Don’t keep stored greywater for more than a day, as bacteria can grow.

You can leave a bucket in your shower or bowl under the bathroom and kitchen tap to collect water while it’s warming up.

Greywater diversion systems

A greywater diversion system can divert greywater to an irrigation system. This is good for low-risk sources of greywater, such as the bath, shower or washing machine.

If you are diverting your greywater to your garden, be mindful to use greywater-safe cleaning products or laundry detergent as they can affect your soil.

Greywater treatment systems

A greywater treatment system collects and treats greywater created in your house. Treated greywater is more clear and odourless than untreated greywater, and can be used to:

  • flush toilets
  • fill the washing machine
  • wash vehicles
  • water lawns and gardens.