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What is Greywater and Blackwater?

Types of Wastewater - Greywater and Blackwater

Every day the water we use in our household ends up becoming wastewater. The wastewater, depending on where it was used, and any chemicals in it ends up either as blackwater or greywater. For example, the water used in toilet is heavily contaminated and classified as blackwater, whereas the water used to wash your hands has low level of contaminants so it deemed greywater. The wastewater can be reused and treated with biological and chemical methods for recycling.

What is Blackwater?

Blackwater is the wastewater from toilets or urinals which consists of urine and fecal matter. Water from kitchens and dishwashers can also be classified as blackwater due to the presence of pathogens and grease.

Blackwater has a higher level of organic matter compared to greywater and is a hotspot for disease-carrying pathogens. This type of wastewater is unfit for human and animal consumption and blakcwater must not be used for household purposes or recycled as it cannot break down effectively in on-site treatment plants without the risk of contamination.

How is blackwater treated?

Blackwater can be treated by biological and chemical methods using on-site sewerage facilities like:

Looking to install a Home Sewage Treatment Plant? Let our wastewater experts help you.

What is Greywater?

Greywater is the water from non-toilet plumbing fixtures like taps and showers.

A large volumbe of greywater comes from household activities like dishwashing, laundry, and showers. There are organic pathogens, bacteria and chemicals present in grey wastewater but it can usually still be recycled for household purposes. Greywater hasn't come in contact with fecal waste so it is unlikely to contain disease-carrying pathogens and can be broken down safely during treatment and in gardens and lawns. The chemicals and organic matter present in the greywater can be absorbed by worms, plants and microbes in the soil. It can also be treated and used to flush the toilet and in the laundry.

How is greywater treated?

Biological treatment methods like sand filters and coarse filtration techniques can be used to treat greywater.

Both greywater and blackwater are not suitable for consumption.

If you are planning to reuse greywater in your home, make sure there are separate channels for greywater and blackwater. This will prevent contamination of greywater and also help you reuse water safely. It helps to minimise the use of chemicals in your home and regulate what you flush down the drain.

What is Greywater or Blackwater Infographic

Benefits of Reusing Greywater

  • Conserves water
  • Irrigates the garden using minimum resources
  • Reduces water bills
  • Puts less strain on municipal infrastructure for treatment, and disposal

How to improve the wastewater quality in your home?

  • Minimise the use of cleaning chemicals
  • Use natural and non-toxic products
  • Use a sink strainer in the kitchen to prevent food debris from entering your wastewater
  • Avoid using soaps, body wash and detergents with high sodium
  • Clean and replace the lint filter in your washing machine regularly
What is Greywater and Blackwater? Let our experts help you.

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Why Use Express Wastewater Solutions?


    Because we are not a manufacturer and not tied to one particular system we can always offer the best solution for your wastewater needs.


    Because we do this every day we have developed a close knit expert team for every step of the process – from plans and council paperwork to excavations, electrical and plumbing. We handle it all to make the whole process as stress free and quick as possible.


    Most people have never installed a home sewerage treatment plant and don’t know the next step, that is why we offer a free 30 minute phone consult with one of our experts to point you in the right direction.


    We handle your wastewater installation from start to finish we can deal with all the trades, council everything so you don’t have to worry about a thing.


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    Not sure what system is right for you, or want to know if your system is working properly? Just give one of our friendly wastewater experts a call and they will be more than happy to help.


    We will always look to repair your system rather than replace it if it does not need to be, which will generally save large amounts of money sometimes up to and over $10,000.