Grey Water
Greywater recycling and re-use in Australia in 2010
Why Recycle Greywater?
Climate change and population growth have resulted in increasing pressure on drinking water supplies. Greywater is a resource that can be recycled for indoor and/or outdoor purposes. Replacing the use of potable water for toilet flushing, washing machine supply and/or garden irrigation with greywater will reduce both the demand on drinking water supplies and the amount of sewage effluent discharged to the environment. By using treated greywater instead of drinking quality water for these purposes, more water is available in potable supply dams providing greater water security for cities and towns.
Kitchen Greywater
It is a common misconception that greywater does not contain pathogens and that it is only sewage and blackwater that require treatment prior to disposal or recycling. However, greywater can contain pathogens, and if poorly managed, can present a risk to human health and the environment. Raw greywater contains salts, especially sodium from powdered detergents, which can have a detrimental effect on soil structure and health. Raw kitchen wastewater which contains fats, oils and grease should not be diverted to gardens because they can reduce the availability of air to plants and harm micro-organisms. However, when greywater is treated using an advanced approved wastewater treatment system the resultant effluent can be safely applied to land by following the guidelines the Australian Standard AS/NZS 1547 Onsite Domestic Wastewater Management and relevant State wastewater code.
Due to the difficulty of treating fats, oils, grease and the high load of organic matter in kitchen wastewater most greywater treatment systems exclude kitchen water from the waste stream. The kitchen wastewater must, therefore, be diverted to sewer (or to a septic tank in unsewered areas).
Information regarding grey water rebates and the Green Loans Programe is available at the base of this page.
State Regulations
The grading, regulations and re-use options of treated Grey Water varies from State to State and at times even council to council. Manufacturers are required to put their systems through a six month testing process then apply to each state for approval to install systems. The systems water re-use options are dependent on the water quality acheived during the test period in accordance with the states relevant code and re-use options permitted. Currently re-cycled water from systems that achieve the highest grading can be used back into the home in Queensland, New South Wales and Victoria, while the other states generally only permit garden use of the water regardless of the quality.
The following is a state by state guide to each state's approach to recycled grey water.
Queensland
In 2007 as part of the Government's Climate Smart 2050 strategy, greywater re-use was recoginsed as part of the strategy needed to help secure future water supply and encourage the uptake of water efficient technolgy and behaviours. The Queensland Development Code details the specific uses of grey water through diversion, treatment and advanced treatmeat and found at www.dip.qld.gov.au/guidelines/queenslanddevelopmentcode
The recycled water from advanced treatment systems can be used for toilet flushing, cold water supply to the laundry as well as around the house hosing and sprinkler irrigation. A downloadable PDF is offered by the the Department of Infrastructure titled 'watersavings targets' to assist homeowners, councils, developers and builders understand what is permissable and the process. Greywater installations are regulated by the Queensland Plumbing and Wastewater Code. All links and PDF's are available on our website in the NovaGrey product section.
Victoria
Greywater regulation in Victoria is covered by the Victorian EPA's Code of Practice - Onsite waste water management plublication 891.2, dated November 2008. This document can be found at www.epa.vic.gov.au/water/wastewater/onsite
The Code recognises the role of recycled greywater helping to deal with the effects of Climate Change and poputation pressure on our drinking water supplies. As with the Queensland the code, it lists treated water into three catagories from untreated diversion up to advanced treatment suitable for internal re-use. Advanced treatment systems produce safe water by achieving what is termed a 10/10/10 standard in the treatment of Suspended Solids, Biochemical Oxygen Demand and removal of E.Coli.
Table 5.1 in the Code of Pratice outlines the permitted uses of the recycled water.
New South Wales
On July 1st 2010,The NSW Office of Water published guidelines for greywater use in households
The guidelines state that 'greywater can replace drinking water for irrigating gardens or lawns and, and if treated appropriately can be used in toilets and washing machines. The guideline also suggest using recycled greywater can save the household 100,000 of litres of drinking water each year. The benefits listed include;
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Reducing Potable Water Consumption
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Reducing the amount of sewage discharged to oceans or rivers
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Reducing Water Bills
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Maintaining a healthier garden, especially during drought periods.
The uses permitted are from bucketing, diversion and proper tretament with an approved system for in house re-use.
The website includes several fact sheets to use as a guide when considering purchasing and installing a greywater system. The fact sheets can be downloaded from the Solutions>Downloads section from our website.
