Greywater Reuse Systems

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Friendly detergents and chemicals PDF Print E-mail

Chosing ‘friendly’ detergents and cleaners

 At the individual household level, it may seem that the quantities being discharged are insignificant. However, the cumulative impacts from whole suburbs can be significant. You can make a difference. 

Click here for a List of chemicals. Please note the ones at the bottom of the page are better for the enviroment (and they are all liquids) Be aware that most  have either high salt and or high Phosphorous.

Some of the harmful characteristics present in household wastewater include:

  • Phosphorous
  • Nitrogen
  • Salts
  • pH levels
  • Greases and oils
  • Bleaches
  • Corrosive chemicals

Buying and using household detergents and chemicals


  • When buying detergent, read the side of the pack for information on the environmental benefits of the product.
  • Some detergents have the symbol ‘NP’ marked on their packaging. This means that the product contains little or no phosphorous, which is beneficial. Detergents containing phosphorous may be labelled ‘P’.
  • Choose products that have been endorsed by environmental groups or consumer groups for their environmental features.
  • Use detergents sparingly- we often add much more than is necessary.


Laundry Detergents

Salt is included in washing powders as filler. There is generally less salt in concentrated powders, and even less in liquids. Minimising the salt content of your greywater is important to prevent soil salinity.

Washing detergents also include phosphorus and nitrogen, which are nutrients necessary for plant growth, so greywater can be substituted for fertiliser and provide phosphorus and nitrogen to your garden and lawn.

The typical nutrient loads that are applied to the soil by irrigating with greywater are very similar to those that are applied by following the directions on common fertiliser packages. The reuse of greywater, therefore, has the potential to significantly reduce the need for fertiliser application on gardens and lawns. The application of nutrients through the irrigation process is also preferred, as the nutrients will be applied more gradually and will reduce the risk of nutrients being washed away during wet weather events.

However, too much phosphorus in greywater can be toxic to some plants, most notably native Australian plants. If your garden has native plants you should try to minimise the phosphorus content of your greywater by choosing a laundry detergent that is low in phosphorus.

  • Choose a liquid or concentrated powder washing detergent.
  • Choose a washing detergent that is low in phosphorus and salts.
  • The salts, nitrogen and phosphorus content of various washing detergents available in Australia can be found at


Fats in greywater generated from soaps and fabric softeners can make soil water-repellent.

  • The soil will benefit from an application of a soil rewetting agent every six months.

Bleaches and Disinfectants

Bleaches (such as hair dyes and nappy wash), disinfectants (including eucalyptus and tea tree oil) and germicides can detrimentally affect the health of soils by killing soil organisms.

  • Don’t reuse greywater when using cleaning chemicals in the bathroom or laundry, or when using hair dye, disinfectants.