Greywater – Facts and Fiction

Although not of the same quality as the drinking water delivered through your taps, greywater generally contains sufficiently low levels of contaminants and is suitable for garden or lawn irrigation via sub-surface distribution.

With so much information floating around on greywater, we know that it can become confusing. Check out the following facts and fiction.

Please be aware that using buckets to collect greywater around the home can present hazards particularly for children. Collected water - such as baths or buckets - should not be left uncovered and unattended  and water tanks must not be accessible to children. 

When carrying buckets you should be careful of the weight involved and the risk of slipping. Reduce the risk of injury by carrying buckets only half full or investigate options such as trolley devices.

Guidelines for Greywater Use

Dos	Don’ts
Do use wastewater from baths, showers, sinks and washing machines.	Don’t use wastewater from the kitchen sink - the concoction/mix of fats, oils and food scraps is unsafe to use on your garden.
Do use phosphate-free detergents if you are using greywater from your washing machine – your plants will thank you for it.	Don’t store greywater for more than 24 hours.
Do stop using greywater if your plants are looking sickly.	Don’t let your children or pets play with or drink greywater.
Do put your greywater directly onto the roots as close to the soil as possible. This can reduce the survival rate of microbes.	Don’t use greywater for your vegetable or herb garden.
Do wash your hands after watering with greywater.	Don’t irrigate your garden with greywater in wet weather, or if the soil is already damp.

Greywater consists of all non-toilet wastewater.

FACT: It includes wastewater from showers, baths, spas, hand basins, washing machines, laundry troughs, dishwashers and kitchen sinks. When considering a greywater system it is advised that kitchen wastewater (including dishwashers) is not used. This is due to the high concentration of food wastes and chemicals that are not readily broken down by soil organisms.

A licensed plumber must be used to install a permanent greywater diversion system.

FACT: You must use a licensed plumber to install a permanent diversion system. These systems treat and store your greywater and can divert it for both toilet flushing and garden irrigation. You should also contact your local council to check whether any permits are required.

Greywater cannot be used to irrigate a vegetable garden.

FACT:Yes, but you can use it on nearby fruit trees, lawn areas and on other plants (both exotic and native shrubs and trees).

You can only store greywater for 24 hours.

FACT: Greywater must be used immediately. This is to prevent breeding of microbes.

I can buy products from the hardware store for temporary greywater diversion.

FACT: There are a number of off-the-shelf products available from your local hardware or plumbing shop to divert greywater direct to your garden. Usually people divert washing machine (final rinse) water and shower water onto garden beds through existing plumbing inspection hatches.

If you divert from the washing machine make sure the diameter of the diversion hose is not smaller than the washing machine hose or it may permanently damage the pump or burst the hose connection and flood the laundry.

Greywater is bad for your garden

FICTION: Greywater can be reused safely and effectively if used correctly. When setting up your greywater system for your garden, make sure you follow the guidelines set out by the Environmental Protection Authority (EPA) below.

Greywater is costly to set-up

FICTION: The easiest way to collect greywater is by using a bucket in the shower, sink or laundry trough – it’s simple and it’s free. If you want to install a greywater diversion system – they range from simple and cost effective to more high-end versions that not only treat the greywater, but direct it for toilet use. Contact your local plumber to talk about the system that is best for you and your budget. If you are considering installing a greywater treatment system you must get your local council and EPA approval.

You need permission for a temporary greywater diversion system

FICTION: You don’t need permission for a temporary greywater diversion system. This is a system that temporarily diverts greywater away from the sewerage system during warm, dry weather - for immediate use. The greywater is not stored or treated, and can be redirected to the sewer in wet periods.

The dos and don’ts listed on the EPA website titled ‘Household greywater reuse in Victoria’ also apply.

If you are designing or renovating your house, call a green plumber to ensure greywater use becomes a part of your design. 

Remember there is a rebate of $500 on permanent greywater systems. Your system must be installed by a licensed plumber. You can purchase a greywater system from your local hardware or plumbing supplier.

Need more information?

1. Visit the EPA website at www.epa.vic.gov.au and click on water, reuse.

2. www.greenplumbers.com.au

3. www.ourwater.vic.gov.au

4. www.lanfaxlabs.com.au