Salty water anytime, but we won’t drink sewage!

· And the list goes on….

By now you would have thought that despite three urban drought "crises" in Australia alone, we would have solved the issue. No, why do that, when the conference circuit is one of the great perks and opportunities for scientists, engineers, media and bureaucrats to get together chinwag, eat, drink and dance at their employers' (and hence our) expense. That's a lot of travel-generated CO2 gas emissions!

Potable water recycling was included along with desalination and dam building as part of three options for Sydney's future water supply back in 1970, when the Welcome Reef Dam was chosen to meet the next 50 years of demand growth. At that time potable recycling and desalination technologies were deemed too expensive and too underdeveloped. So, what happened? Environmentalists damned the idea of the dam and Sydney blundered on, full steam ahead for the inevitable next big water crisis, when Sydney's water demand would outstrip supply, which occurred in the late 1990s.

A time of "golden opportunities" arose for international consultants to design, build and operate these water desalination factories and the state government treasurers looking to collect opportunistic taxes and profits from the community. Desalination plants for all! Hence by 2009 Australia was in the top 10 countries worldwide for desalinated water production at an estimated capital cost in excess of $20 billion, along with a $2 billion per annum operating energy bill. Despite using the same technology, but a third the energy, potable water recycling was ignored or positively attacked as being unacceptable, risky and unhealthy.

Around the world, countries continued to supply traditional water at 3-5 star quality, while Australia politicians and the water industry bodies continued to promote the merits of desalinated water which is (6-star). In some cases, 'brave' politicians in the mid 2000s, such as the Queensland Premier and Toowoomba Mayor tried and failed to implement potable recycling. In some countries, they maintained their resolve. Singapore now gets 10% of its drinking water supply from recycled wastewater. Even in conservative USA, several modern (2010+) potable recycling schemes are up and running, and in Namibia (Windahoek), they have been running a potable water recycling plant since 1968!

Water crises are not necessary, but are popular with politicians, bureaucrats and the water industry to gain access to funding and approval to build infrastructure (which makes money for those who own or run it). If you can't make money out of water, you should give up as its usually a monopoly business, is an essential service and is a relatively simple business to operate. However, vested interests have managed to use the scaremongering of politicians and ill-informed media to "poo-poo" potable water recycling. They come up with arguments about health and potentially unknown consequences. Scientists and the water industry bodies hide behind "Risk Management Frameworks" which impose irrationally strict guidelines on anyone who even thinks about undertaking a potable water recycling scheme.

Meanwhile the performance and regulatory frameworks for traditional water supplies are orders of magnitude less stringent. In essence, traditional tap water (which is perfectly healthy is 3-5 star depending on where you live in Australia (regions 3-4 or Capital Cities 5), while desalinated water and potable recycled water are 6 star. Interestingly, the strict standards (frameworks/ regulations) applied to potable recycling are not applied to desalinated water, even though both use the same processes to produce their pure water.

Traditional water supplies use simple settling and crude filtering plus chlorination. Many country towns must rely on this 19^th century approach and, if managed well, can produce adequately safe drinking water (3-star). Until 1995, that is how even Sydney's main water supply operated, and Melbourne's too. They now each have a treatment facility and produce 4-star water, like many regional cities.

In the case of desalinated water and potable recycled water there are three to four additional treatment steps, which include microfiltration to remove fine particles, reverse osmosis membranes to remove dissolved contaminants (chemicals, pharmaceuticals, miniscule parasites, etc) and finally oxidation and/or Ultraviolet exposure to polish the water even further. This produces water so pure (6-star plus) it must be conditioned with softeners to make it compatible with the human body. Most bottled water is treated through the same process train as desalinated and potable recycled water, yet we are will to pay 1000 times the price for it, just for convenience and fashion.

The simplicity and sustainability of potable water recycling is that it solves many problems. Firstly, water security becomes very high and the water is used many times.

Secondly, it can source water from wastewater, stormwater and rainwater collected in urban catchments (which ironically often receive better rainfall amounts than their traditional dam catchments, e.g. Sydney's water catchments receive 8-900 mm annually, while the City receives 11-1200 mm annually).

Thirdly, by treating wastewater to create recycled drinking water (6 star) quality, we can remove all the waste particles, including drugs, fine particles, metals etc and hence when the water is finally returned to rivers, we produce no water pollution issues and hence improve the river/lake and ocean environments for nature and in-turn ourselves through non-contaminated fish/ oysters/prawns/seaweed. And the material removed can be 'mined' or reused as fertilizer, hence reducing our dependency on other natural resources.