Grey water is something that every Perth home owner should know of, but there is a lot of grey area to be explained!

Grey water is something that every Perth home owner should know about, but there is a lot of grey area to be explained!

What is Grey Water?

Grey water is the used water in households that can be captured and reused. For example showers, sinks and laundry water is grey water. Blackwater is sewage or waste water that comes from toilets. In most homes water from the kitchen (dishwasher and sink) have too much organic material to efficiently and safely reuse as potable water?

Grey water comes from:

  • Showers and baths
  •  Washing machines
  • Wash basins
  • Spa baths
  • Laundry

Kitchens are classified as “dark” grey water.

How can I reuse Grey Water?

Grey water once captured can be reused in on the same property as water for gardens, lawns and orchards.

Untreated grey water can only be used for subsurface irrigation through drip line. Because the untreated grey water has varying levels of bacteria and active microbes it is not as useable as treated grey water.  It can have a distinctly bad odour and it can clog irrigation quickly.

The Department of Health has restrictions and guidelines to how untreated grey water can be used. See lesiglation via this link! 

Treated greywater has much more application. Treated grey water can be used in above ground sprinklers and irrigation, washing machines and toilet flushing as internal home water uses.

Weighing up the Pros and Cons

If you are planning on living in your house for many years then it is the right thing to do. You water bill will be reduced by thousands and you will be living more sustainably with less overall water consumption.


  • Reduced household water bills
  • Healthier garden with more access to water in periods of drought
  • Reduced overall water consumption (sustainable living)


  •  Initial cost
  • Health risks when grey water is not used appropriately

Can you get sick from grey water?

Not if your grey water treatment system is designed properly and maintained to a high standard.

In most households, grey water has a high nutrient loading. This means there are above average concentrations of sodium, nitrogen, phosphates and other impurities. Before grey water can be used it must be treated to balance or remove unwanted impurities.

By maintaining your grey water treatment system you will continue to be able to reuse water safely.

How does Grey Water help my garden and lawn?

Because grey water has a high nutrient loading it is actually very easy and healthy for your garden. Grey water treatment systems balance out nutrients in such a way that the water is healthier than the normal scheme water provided by Water Corporation.

The nitrogen, phosphates and salts give gardens life. But only when they are balanced – too much or too little will kill gardens as with anything in life!

Do cleaning products effect grey water?

Yes, but you don’t need to change what you are doing. Most homes do not use washing powders in quantities enough to overload grey water treatment systems.

Cleaning products have high levels of sodium and chemicals that change water acidity (ph.).  But prior to installing a grey water system we will take water samples for analysis. The results of the analysis take into account cleaning products and the grey water will be designed to rebalance the acidity and salinity of your grey water.

See more via the button below or contact us for a quote.

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3/14 Brolo Ct, O'Connor 6163, WA