Grey water is used water from your shower, your hand basin and your washing machine. It’s household waste water that when treated is re-usable for things such as washing your car or boat, watering your garden, re-use in the washing machine and flushing the toilet.
The average household in Australia sends approximately three hundred litres of grey water back into sewerage pipes. Rather than wasting this grey water, you can install a grey water recycling system in your home. This way, when water fills the grey water tank, rather than using mains water, you can use the grey water. Grey water tanks not only help our environment, but they help you save money as the cost of water increases.
A major concern with grey water tanks is that it may be contaminated from urine in the shower or bath, or may contain other contaminants. Urine is sterile when fresh, and will generally not become contaminated. In fact it contains some vitamins and nutrients that in small volumes are good for the garden. Grey water systems automatically pump waste water that has not been used over a 24 hour period as per state regulations. Systems can also be flushed by easily opening a valve and redirecting the grey water directly to your sewer.
Grey Water Treatment Systems
Grey water systems treat the grey water to improve the bacteria load and chemical pollutants so that it can be stored. However, satisfactory grey water treatment tends to be neither cheap nor simple. Grey water systems have treatment processes that include filtering, settling of solids, anaerobic or aerobic digestion, chemical removal of pollutants and disinfection. Before installing a grey water treatment system you will need to seek advice from the Victorian Planning and Land Authority.
Plumbing
If your grey water system requires connection to the sewerage systems, i.e. the pipes below your sinks, shower or bath, this work must be carried out by a licensed plumber.
If you intend to intercept grey water before it enters the sewerage system, i.e. before it enters the drain hole of a sink, you can do this yourself. This may be a simple setup in which you bucket water from a sink or direct the grey water from your washing machine to your garden or grey water tank with the use of a hose.
Regulations about Grey Water Use
The use of grey water tanks does come with strict regulations to protect you and those around you. As such, airborne sprinkler systems are not allowed to be used with grey water tanks, and the use of the product does require permission from your local health authority. To reduce the risk associated with grey water systems, the following measures can be taken:
- Do not use sprinklers to distribute grey water.
- Use subsurface irrigations systems.
- Do not put grey water on food plants.
- Do not put grey water on lawns where children are likely to play.
- Do not allow grey water to leave your block.
- Do not irrigate grey water during periods of wet weather.
- Do not allow grey water to enter storm water drains, and
- Make sure that your grey water tank and the grey water does not become odorous and a nuisance.
The Public Health Act 1997 can be used to control actions that would impact on the health of your neighbours. If grey water flows onto your neighbour’s property, or odour becomes a problem, this act could regulate your activities.
The Environment Protection Act 1997 can be used to control actions that would cause environmental impact. For example, if you allow grey water from your grey water tank to flow off your block or to contaminate ground water or soil this Act could regulate your activities.
The Water and Sewerage Act 2000 and the Water and Sewerage Regulations 2001 require that any modifications of the drainage of waste from sinks, baths and showers for diversion to a grey water tank be conducted by a licenced plumber. Plumbing and drainage work associated with the installation of a grey water diversion valve or treatment system must also be carried out by a licensed plumber. The licensed plumber must notify Victorian Planning & Land Authority of their activities, the same as they would with any other plumbing installation.
The Victorian plumbing legislation does not apply to the installation of a hose to carry grey water directly to an irrigation area or a fitting used for the operation of a grey water diverter.
Back to Top |
