Greywater and wastewater


What is greywater, blackwater and wastewater?

Greywater is household wastewater from non-toilet fixtures such as showers, taps, basins, washing machines and floor drains. It should not include kitchen sink and dishwasher wastewater because of pollutants such as oils, fats and food particles. 

Greywater can be reused for some home purposes. 

Blackwater is household wastewater mixed with waste from toilets. Blackwater should not be reused in the home as it may contain harmful organisms. 

Wastewater may include both greywater and blackwater. Wastewater may also be known as “sewage”.

What happens to wastewater?

The wastewater from individual houses, units and businesses enters a network of pipes and pumping stations to get to one of Council’s eight sewerage treatment facilities, where it is processed.

Treated wastewater may be discharged into the ocean or used to water outdoor sports facilities such as golf clubs.

How is wastewater treated?

Wastewater is processed at one of Council’s eight sewerage treatment plants. The bulk of wastewater then undergoes a secondary treatment and is discharged into the ocean at Kincumber, Norah Head or Wonga Pt ocean outfalls.

Some secondary treated sewage undergoes additional treatment and is used to water outdoor facilities such as golf courses.

Can I reuse greywater?

Yes, but you should not drink it.

How much water can I save if I reuse my greywater?

Using greywater outdoors could save each household up to 30,000 litres of drinking water each year.

How can I use greywater?

There are two types of greywater systems that allow you to use greywater in different ways:

  • A greywater diversion device allows untreated greywater to be used for outdoor purposes by distributing water to your garden through a below-surface irrigation system.
  • A greywater treatment system enables you to use treated greywater for above surface irrigation, flushing toilets and in washing machines. Treated greywater can also be stored. 

Is there any way I can collect and use greywater for free?

You can manually collect greywater using a bucket in the shower or laundry for reuse in the lawn and garden.

If I use greywater, can I water at any time?

To avoid water loss from evaporation, avoid watering between 10am and 4pm.

Is greywater suitable for vegetables, fruits and herbs?

No. Greywater may contain pathogenic organisms and should not be used to water any plants which will be eaten raw.

What should I do with spare greywater?

Unwanted greywater should be released through your sink or toilet into the sewerage network. It should not be released onto the street or into the stormwater system.


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