Despite the continued resistance from climate sceptics, the urgency of the climate crisis becomes clearer by the day. And so does the realisation that, by necessity, sustainable housing will have to be an important part of its solution. Have you ever thought about your home’s wastewater? If not, continue reading, you will be shocked.

On this article:

  • What is wastewater reuse?
  • Benefits of using wastewater in your home or business.
  • Improving the quality of the greywater.
  • Reusing wastewater outdoors.
  • Reusing greywater indoors.
  • Summary of wastewater systems for your home or business.

What is wastewater reuse?

On-site wastewater reuse can reduce water use in both urban and rural households. At present, most homes use potable (drinkable) water for practically everything in the house and garden, even flushing the toilet.

Your home is likely to create 2 types of wastewater:

  • Greywater is wastewater from non-toilet plumbing fixtures such as showers, basins and taps.
  • Blackwater is water that has been mixed with waste from the toilet. Because of the potential for contamination by food waste, pathogens and grease, water from kitchens and dishwashers should be excluded from greywater and considered blackwater.

Each wastewater type must be treated differently and can be used in various ways.

wastewater per household
Typical percentage of wastewater generation from household sources.

Benefits of using wastewater in your home or business:

  • reduce water bills
  • use fewer water resources
  • irrigate the garden during drought or water restrictions
  • cut down the amount of pollution going into waterways
  • help save money on new infrastructure for water supplies and wastewater treatment
  • decrease demand on infrastructure for sewage transport, treatment, and disposal, allowing it to work better and last longer.
Wastewater reuse system diagram
How to reuse your home's wastewater in a simple diagram.

According to Australian Government estimations, an average individual yields 84 L of greywater waste every day. This means that in a household of 5, over 153,000 L could be used as a resource rather than waste!

Imagine how could you help the environment by implementing a sustainable wastewater system. Moreover, imagine how much you would cut your bills. Something to think about right?

But, of those over a hundred thousand litres, how much can be used and for what purposes? 

Improving the quality of the greywater.

The quality of reused water depends on the treatment system, the water’s previous use, and the chemicals used in the home. You can take action to improve wastewater quality and simplify treatment requirements.

For greywater:

  • Minimise the use of cleaning chemicals. Use natural or biodegradable cleaning products where possible.
  • Use low- or no-sodium laundry detergents, soaps and shampoos.
  • Use a lint filter in washing machines. Clean and replace as necessary to ensure water can flow through it easily.
  • Switch to water-saving devices like low-flow faucet aerators, low-flow showerheads, shower times, dual flush toilets, bathwater diverters, soaker hoses, etc
  • Use full loads in the washing machine and dishwasher
  • Do not dispose of household chemicals down the sink. Contact your local council or water authority for information on chemical collection services.

How you can reuse greywater depends on where you live. Wastewater reuse in urban areas differs from reuse in rural areas. Also, the water treatment will vary depending on whether you are reusing outdoors or indoors.

In this article, we will focus on urban areas, as water reuse in rural areas would better fit an independent guide. 

Improve your wastewater quality
Minimise the use of cleaning chemicals

Wastewater reuse is key in sustainable homes

Our qualified plumbers know how to reuse your home’s wastewater. Give us a call!

Reusing wastewater outdoors

A family can use 30 to 50 per cent less drinkable water by reusing wastewater outdoors. But there are several safety and environmental measures that must be followed.

If veggies are to be consumed raw, avoid watering them with recycled or wastewater. Even after treatment, it is possible that some harmful organisms will remain.

The amount of wastewater reuse must be matched with the amount of water, sediments, and nutrients that the plants and soil in your garden can absorb in order to preserve the health of your garden. If excess wastewater is applied:

  • A surplus of nutrients could flow off or seep through the soil into waterways, causing algal blooms and other issues with water quality.
  • soils and plants may become waterlogged and inhibit plant growth
  • soils can become physically clogged with organic and suspended material or damaged by salts in the wastewater
  • salinity may increase in problem areas when greywater contributes to rising water tables.

Avoid these problems by:

  • planning your garden carefully
  • using phosphate-free and salt-free liquid or environmentally friendly detergents
  • filtering to remove solids.

Adjust the amount of wastewater to conditions in the garden. Do not irrigate if the soil is already saturated.

How to Reuse your Home's Wastewater
Source: oasisdesign.net/greywater/createanoasis

Reusing greywater indoors

It is typically more cost-effective to use rainwater indoors and greywater outdoors in homes with access to a consistent rainwater supply. Greywater that has been treated can help you conserve water indoors if you are unable to gather enough rainwater.

Greywater that has been properly treated can be utilised for laundry and toilet flushing, two home activities that require a lot of water on average. An average family can save 50L of potable water per day by reusing treated greywater for toilet flushing. An average family can save about 90L of potable water per day by reusing treated greywater in the washing machine. 

Greywater that is used to wash clothes again yet contains dissolved organic material may stain fabric. This issue can be solved by using an activated carbon filter on the water entering the washing machine.

Greywater for reuse indoors generally only comes from showers, hand basins, and laundries.

As long as it is used right away and is not kept for more than 24 hours before being reused or disposed of in the sewer, greywater from the shower or bathroom sink can be directly diverted for toilet flushing. It requires coarse filtration.

Greywater treatment and disinfection systems must be approved in your state and be used on any laundry, shower, or sink waste that is kept for more than 24 hours.

Important Note: Greywater can include dishwashing and kitchen sink waste, but it needs more complicated processing before it can be used again. In several Australian states, household cooking water cannot be recycled as greywater.

Summary of wastewater systems for your home or business:

a) Aerated wastewater treatment system

An aerated wastewater treatment system, otherwise known as an AWTS, was developed as a way of both adequately treating and reusing wastewater in a safe and eco-friendly way. It is used for the treatment of domestic wastewater from either one or multiple homes, through various treatment ‘chambers’ which are attached to an irrigation system. The treated wastewater can then be used to water your garden or other areas of your property.

b) Greywater collection system

Greywater can be used to clean driveways, wash the car or water the garden. It can also be used in the toilet.

Greywater is the sewage produced in the kitchen, bathroom, and laundry. Installing a treatment system or a greywater diversion is an option. The technique entails rerouting domestically useful effluent from the sinks, showers, and washing machines.

There are different types of greywater collection systems like:

  • Diversion
  • Diversion and filtration systems – the water is filtered from hair, lint and other contaminants before it is used
  • Diversion and treatment systems – The water is treated by biological and chemical methods or a combination of both. The resulting water is clean and safe to use for household purposes

c) Install toilet tank sink 

It is a circular system wherein the sink is integrated with the toilet. It is designed to recycle and conserve water. The toilet sink combo allows you to reduce your water consumption and save on water bills.

The sink uses freshwater so you can wash your hands. And the greywater gets stored in the toilet tank. So when the toilet gets flushed, greywater is used.

Now you know better. Upgrade your house plumbing with wastewater systems.

Every drop of water conserved is important. We don’t give our water usage much thought as long as there is neat water available.

Now you know how much you waste and how to solve the issue. If you need more detailed advice on wastewater systems, don’t hesitate to reach out. Our qualified plumbing division will walk you through the best sustainable plumbing solutions for your house or business!

Wastewater reuse is just one call away!

Our qualified plumbers know how to reuse your home’s wastewater. Give us a call!

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