Recycling greywater is one option that can be used to replace tap water on gardens. Rainwater tanks are another.

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What is greywater
There are two types of greywater recycling systems

There are some areas that are not suitable for greywater recycling. Such as environmentally sensitive land, escarpment areas, areas that have rare plants or threatened species, where soils are shallow or on properties in close proximity to waterways. For these reasons rainwater tanks are preferred.

The characteristics of greywater are influenced by the number of occupants, lifestyle and water usage patterns. There are many things to consider if you are to use greywater safely. NSW Water publishes guidelines on greywater reuse, including figures to help you calculate your water use and needs.

What is greywater?

Greywater is the wastewater from your shower, bath, hand basin, laundry tub and washing machine.

Water from a dishwasher and / or the kitchen sink is referred to as dark greywater. It has a higher load of chemicals, fats and organic matter.

Water from toilets is called blackwater.

Greywater recycling systems can only be installed on a property that is connected to sewer. Greywater should not escape from your property into a neighbouring one, into stormwater systems or aquifers used for drinking water — in fact it is illegal.

There are two types of greywater recycling systems

Diversion devices

Diversion devices redirect greywater for reuse outside on garden or lawns without treating it. No council approval is required provided that the greywater diversion device has a WaterMark licence. Untreated greywater should only be used for sub-surface garden irrigation — that is, through a network of pipes buried at least 100mm below the ground – to reduce the risk of human or animal contact.

There are limits to what you can do with untreated greywater because of the chemicals and bacteria in it. Stop using greywater when someone in the family is sick with gastroenteritis or another contagious disease, or during rain periods. Do not water herbs or vegetables with greywater.

Greywater treatment systems

These systems collect and treat the water to various levels of purity and hygiene. Treatment may include filtration, removal of chemicals and disinfection by chlorination or UV light. These types of systems can be used to recycle water to the toilet and washing machines. Greywater treatment systems must have a Certificate of Accreditation issued by NSW Health. Treatment systems also require an approval from Council. If you are thinking of installing a treatment system please talk to one of our environmental health officers.

Greywater treatment systems need to be maintained with regular servicing and filter replacements.