<div id="myExtraContent1"> </div>
<div id="myExtraContent5"> </div>
Available Greywater Systems
There are three different types of Greywater systems approved for use in WA, and each has a different end use or conditions of approval. Most greywater systems are Greywater Diversion Devices (GDD). The second type of greywater system is a Greywater Treatment System (GTS). The third category of approval is manual bucketing. This means that you can collect the wash water from the laundry trough, for example, and use this to water plants.

Diversion Devices

GDD provide only a minimal level of treatment, which is the filtering or removal of solids, such as hair and lint. The recycled greywater can only be used for subsurface garden irrigation, which includes dripline or piped trenches. These are installed below ground with 100 mm of soil or mulch over the irrigation system. Subsurface irrigation reduces the risk to humans, pets and other animals of coming into contact with disease-causing organisms.

There are two main types of Diversion Devices:

1. Gravity device

Greywater is diverted from the source, usually by a hand-activated tap or valve, and flows by the use of gravity to the irrigation field. These systems are ideal if the property has sufficient slope. For dripline at least two metes of vertical head pressure is required for the drippers to emit water. For piped trench systems a minimal fall is all that is required to disperse greywater into the soil.

2. Pump device

Pump devices often incorporate a surge tank to cope with sudden influxes of greywater, and then it is pumped under pressure to the irrigation field. The surge tank acts as a temporary holding tank and not as a storage tank, as greywater cannot be stored for more than twenty-four hours as it can turn ‘septic’. Some pump systems are activated as soon as greywater enters the tank, while others collect greywater during the day (or night) and pump out when a reasonable volume is obtained.

Treatment Systems

GTSs use a number of strategies to filter, clean and disinfect greywater so that it can be safely used in the house. Treatment will reduce solids, nutrients and micro-organisms. This allows the treated greywater to be returned in-house and used for toilet flushing and/or for laundry use. The effluent from GTS approved in WA, can also be used for garden irrigation.

Some Greywater Treatment systems have a service agreement as part of the approval and installation conditions. This means that the homeowner pays an annual fee for regular checking and monitoring of the system. It is important that treated greywater is safe, is kept at a high quality and contains no disease-causing organisms. Only authorised, trained service contractors can undertake this service work.

What are Some Typical Costs for Installation?

Simple gravity systems may only cost hundreds of dollars for the unit, with installation extra depending on plumber and installer time, what piping needs changing, what application fees are required, and so on.

Pumped diversion devices could be up to several thousand dollars for the unit, with installation several thousand dollars more. Treatment systems are more expensive and may be ten thousand dollars or more fully installed.

How Can I find Out More?

You can obtain list of the approved greywater systems by contacting your local Council or downloading from the Health Department website. A quick internet search for ‘approved greywater systems in WA’ will enable you to find the list, and save and print it off in a pdf format.
<div id="myExtraContent7"> </div>
<div id="myExtraContent8"> </div>