Supply options
Direct piped from a water recycling plant for irrigation purposes
Treated wastewater can provide a viable water source for the irrigation of parks, public gardens and golf courses, especially where the potential reuse site is in the vicinity of an existing wastewater treatment plant. The treated wastewater is piped directly to the potential reuse site, stored and used via the irrigation network.
Community scale (third pipe) treated wastewater schemes
Treated wastewater from a water recycling plant is transported via a third pipe scheme to multiple users for watering lawns and gardens and for in-house non-drinking uses, such as toilet flushing and the cold water tap in laundries. The scheme can include irrigation of public open space within the community. This is most viable in new urban developments where the required pipelines can be installed together with other below-ground infrastructure.
Aerobic Treatment Units for single households in unsewered areas
Aerobic Treatment Units (ATUs) are a more advanced alternative to conventional septic tanks and provide an improved quality of wastewater treatment for single dwellings in unsewered areas. ATUs must be approved by the Department of Health and inspected by the local government. A permit to use the apparatus is issued by the local government prior to its use. The chlorinated effluent from ATUs may be used to surface irrigate garden areas but can only be used below grassed areas. It is not approved for any use in vegetable gardens.
A Code of Practice, a list of approved ATUs and required application forms and guidelines are available from the Department of Health website.
Managed aquifer recharge
There is growing interest in opportunities to inject or infiltrate treated wastewater, sourced either from wastewater treatment plants or sewer mining, into an aquifer for later abstraction to irrigate public open space, horticulture or for other reuse.
The Department of Water has developed a state wide policy – Draft Strategic policy 1.01 – Managed aquifer recharge in Western Australia – to address environmental and allocation management impacts of managed aquifer recharge.
This policy aligns with the environmental risk assessment approach taken in the Australian Guidelines for Water Recycling: Managing Health and Environmental Risks (Phase 2) Managed Aquifer Recharge (July 2009).
For more information on managed aquifer recharge and a copy of the Department of Water draft policy click here.
Further information on these supply options can be found in the Non-drinking water supply options section of the toolkit.