By reusing treated wastewater, we can make urban areas less dependent on rivers and reservoirs for their water.
Treated wastewater can be quite pure and drinkable. If the water doesn't quite come up to drinking water standard, it can be used for flushing toilets, in washing machines, for watering gardens, and in industry.
Grey Water Reuse - Reuse of grey water - water drained from showers, baths, washing machines, and kitchen sinks - for garden irrigation, can reduce houshold demand for outside water supplies.
Water Recycling at Rouse Hill - A new residential development at Rouse Hill, Sydney is being supplied with treated wastewater, but only for non-drinking purposes.
Water recycling. Victorian Government Health Information
With increasing pressure on our water supplies as a result of recent drought conditions and population growth in our metropolitan centres, water recycling is becoming established as a way of moving towards sustainable management of our resources and environment.
Water recycling adopts the concept of using water that is "fit for purpose". In practice this means using high quality drinking water for drinking and other personal uses, but not necessarily for purposes where alternative water sources can be safely used, such as toilet flushing, garden watering and crop irrigation.
Water Recycling - Benefits
Water Efficiency and Reuse (PDF). S B White & C Howe. Institute for Sustainable Futures. Sydney University. 1998
Effluent reuse has an important role to play in sustainable water resource management.
- less effluent discharge to waterways.
- less ecological impact of nutrients or other pollutants.
- reduced water demand.
- reduced average dry weather flow to sewage treatment plants.
Water Recycling - Melbourne
Source: Water Recycling Scenarios for Melbourne (PDF). Sustainability and Environment. Victoria. 2003
Link: Sustainability and Environment. Victoria
Proposal: Instead of using drinking water for all watering tasks, to use alternative water resources, such as recycled water from sewerage systems, rainwater collected in rainwater tanks, urban stormwater runoff and greywater, for non-potable uses.
Contents: Melbourne's water systems, the current status of water recycling, a snapshot of the water recycling scenarios considered, with information about economic, environmental and social benefits and costs.
Regional Victoria recycles about one third, and Melbourne less than 5 percent (not including treatment process recycling), of their respective treated sewage effluent. There is only limited recycling of rainwater, greywater and stormwater.
Water Recycling Australia
The Value of Water: Inquiry into Australias management of urban water. Parliament. Australia. 2002.12
Water reuse and recycling
Australia reuses only a small fraction of its wastewater, whether it be stormwater or effluent, and there are major opportunities to improve on this performance.
Water can be reused on gardens and playing fields, for irrigation, in industrial processes, and in the sewage treatment systems themselves, which are heavy users of water.
Developments such as Rouse Hill in NSW have implemented a dual pipe system that delivers both potable and recycled water to homes. Techniques such as Aquifer Storage and Recovery and sewer mining also introduce greater flexibility into systems for using wastewater.
New generation treatment systems
Australia has working examples of facilities that can treat wastewater to the highest standards, up to and including potable water. Technologies used include membrane filtration, bio-remediation, and dissolved air flotation processes.
This technology allows for smaller scale treatment plants - for individual suburbs, office buildings and housing developments. This will offer great opportunities for reuse of water, by creating multiple supply sources. The innovative system used at the Sydney Olympic site at Newington is a model of this direction.
Water Recycling - Australia
Water Recycling in Australia. Australian Academy of Technical Sciences and Engineering. 2004.5
The National Land and Water Resources Audit showed in 2002 that water resources from 26% of Australia's surface management areas and 31% of its groundwater management units were fully or over-allocated. In 1996-7, Australia used 26,000 GL of water, 75% for irrigation, 20% for urban and industrial purposes and 5% for stock and domestic use. Water is a valuable resource in Australia, but in short supply. There is scope to make better use of recycled water, stormwater and rainwater as additional water resources.
This report addresses current trends, particularly since 1999, in the processing, use and methods of application of recycled water internationally and in the Australian States and Territories. It explores a range of water recycling policy issues which include the impact of recycled water on society; the need for the continued assurance of public and environmental health; current regulatory processes and their accessibility to public scrutiny in Australia; the impact and potential impact of the greater substitution of recycled effluent water, storm water and rainwater for drinking water throughout the community and the need for continued investment in innovative research and developmental projects. The report provides observations and recommendations from the issues explored.
Water Recycling Potential - Australia
Issues Encountered in Advancing Australia’s Water Recycling Schemes. Sophia Dimitriadis, Australian Parliament Library, August 2005
There is a pressing need to implement sustainable projects that adequately contribute to Australia’s diminishing water supply while protecting public health and the environment.
As part of integrated water cycle management in urban and rural contexts, realising the potential of water recycling projects is one of the greatest challenges of the 21st century.
Internationally, non-potable reuse is widely practiced but to what extent will these schemes be implemented in Australia?
Water Recycling Potential - Australia
Going for Gold in Water Recycling. CSIRO. 2004.8
Australia could lead the world in water recycling, according to CSIRO scientists. We have the expertise; we have the technology - but do we have the will to go all the way?
Water Recycling Potential - Sydney
Experts Chart Recycling Route. Stephanie Peatling. Sydney Morning Herald. 2003.11.13
The Premier, Bob Carr, has met international experts to discuss a large-scale water recycling operation to help solve Sydney's future water needs.
Singapore's Water Reclamation Department substitutes traditional water stores with high-quality recycled water to top up the island's potable supplies.
Services Sydney, wants to "mine" effluent from the southern sewerage system, process it and re-use it to boost river flows as well as for industrial and other uses.
In Europe sewage is recycled back into drinking water, but academics say it would be hard to convince Australians of the safety of such a scheme.
The price of recycled water is likely to be much higher than the relatively modest price Sydney pays for its water. However, a study commissioned by Melbourne Water found that the price of recycled water will drop as the technology becomes more widely available.
Environmentalists are sceptical of large engineering solutions to the water shortage, saying the energy it would take to reuse the water would significantly contribute to Sydney's greenhouse gas emissions. Instead, they say householders and businesses should learn to make do with less.
Recycled Water and Health
Recycled Water and Your Health. Sydney Water
Recycled water has many purposes. It can be used for flushing toilets, washing cars and watering gardens. It can also be used for fire-fighting and for some construction purposes.
However, recycled water is not appropriate for personal use such as drinking, bathing, cooking, washing clothes or general cleaning inside the home.
It should also not be used on crops that are eaten raw or unprocessed. If you are uncertain whether to use recycled water or drinking water for any purpose, use the drinking water supply.
Staying healthy using recycled water
- Don't drink recycled water
- Don't use recycled water in pools and kids' play areas
- Cover upen cuts before use.
- Wash your hands after use.
- Use normal drinking water for your pets
- Advise visitors that you use recycled water
Recycled Water - Pricing
Recycled Water Pricing. Sydney Water
Recycled water is about one third of the price of drinking water. Plumbing a house for recycled water is more expensive than for a normal house. There is a recycled water service charge and a recycled water usage charge.