Grey water - recycling water at home

Greywater is wastewater from non-toilet plumbing systems such as hand basins, washing machines, showers and baths. When handled properly, greywater can be safely reused for the garden.

Never re-use water from toilets, washing nappies or kitchen water. Do not use greywater on vegetables, fruit, herbs or anything you plan to eat.

Our use of water
The average Victorian household uses many litres of water every day, including in the:

• Bathroom – 50 per cent
• Laundry – 22 per cent
• Garden – 19 per cent
• Kitchen – 8 per cent.

• Never use water that has come in contact with the toilet or any other toileting fixture such as a bidet or urinal.
• Don’t use water that has been used to wash soiled nappies – this is also considered blackwater.
• Don’t reuse the water when you wash domestic pets, because of the high level of bacterial contamination.
• Don’t use greywater from the kitchen sink or dishwasher, as this can be contaminated with grease, bacteria and chemicals.

• Salts
• Food materials
• Household detergents, soaps and chemicals
• Bacteria and other disease-causing microbes.

• Expertise may be needed – consult with a licensed plumber before tapping into your plumbing system. All household plumbing work must be undertaken by a licensed plumber and comply with the Australian Standard AS 3500.
• Use ‘low risk’ greywater – your irrigation system should divert greywater from low-risk sources, such as the laundry rinse cycle, bath and shower.
• Keep it in your yard – your greywater must not leave the boundaries of your property. It must not be allowed to discharge into any (piped or surface) drainage system.
• Keep it out of the stormwater – your greywater must not leak into the stormwater system. Make sure your pipes don’t discharge near any underground agricultural pipes.
• Avoid overwatering – check how moist your soil is and spread the water around; don’t just water in the same place.
• Check for blockages – the contaminants in greywater, like grease and slime, can easily block pipes. A filter may help to avoid this problem.
• Store only for a short time – don’t store untreated greywater for any longer than 24 hours, as microbes will thrive. Your surge tank shouldn’t exceed 80 litres. Make sure you have an overflow drain connected to your surge tank that directs excess greywater straight to the sewer. You may want to get advice from a plumber on installing a settling tank to capture grease.

• Use a coarse filter to reduce the amounts of solids in your greywater. Otherwise, your plants will suffer from clogged soil.
• Ingredients in cleaners and detergents that can harm or kill plants include total salts, sodium, chloride and boron. Check product labels carefully.
• Evidence suggests that microbes from greywater have higher survival rates on the topsoil. All irrigation should be located sub-soil. Never hose, spray or mist untreated greywater.
• You may need to reduce the amount of fertiliser you use (note that native plants don’t like nutrients – plant selection could be critical for nutrients and soil moisture levels). Consult with your local nursery for further information.
• Regularly water your garden with fresh water to help prevent the build-up of salts in your soil.

• Use lower risk sources of greywater, such as water from the shower, bath and laundry rinse cycle.
• Don’t use greywater on vegetable gardens.
• Don’t use greywater if any member of your family is suffering from gastroenteritis.
• Don’t irrigate your garden with greywater in wet weather or if the soil is already sodden.
• Don’t allow greywater to form pools or ponds in your garden. The microbes will thrive, creating an offensive stink and a health hazard.
• Don’t allow your pets to drink greywater.
• Take all steps to reduce public access to areas irrigated with greywater.
• Keep children away from garden areas irrigated with greywater.
• Make sure your swimming pool and any other water features, like ponds and birdbaths, are safe from greywater runoff.
• Encourage all the family to wash their hands before eating.

• Choose phosphate-free or low-phosphate household cleaners and detergents.
• Install a lint filter in your washing machine.

• Licensed plumber
• Your local council
• Environment Protection Authority Tel. (03) 9695 2785
• Department of Human Services Victoria Tel. 1300 761 874

• Waste water from non-toilet plumbing systems such as handbasins, washing machines, showers and baths is known as ‘greywater’.
• Greywater needs to be used carefully. If it’s not used properly, it can make the householders ill and kill the plants you are trying to care for.
• Consult with a licensed plumber before you attempt to alter any plumbing in your home.

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