Promising research findings into natural ways to cleanse polluted water have brought Australia a step closer to a revolution in water reclamation the underground dam.

Researchers at CSIRO Land and Water have for several years been investigating the feasibility of diverting urban stormwater and treated effluent into underground aquifers, where it can be recycled for use on parks, gardens, ovals and farms.

The idea is to harvest surplus water during the wet part of the year, store it underground for some months, then bring it to the surface again for irrigation during the dry season.

Researchers consider these underground dams offer a uniquely Australian solution to the problems of water storage, water conservation and recycling. The water will be injected into appropriate aquifers, where it is protected from evaporation or pollution and does not submerge valuable land or habitat, as does a surface dam.

Now, microbiologist Dr Simon Toze has produced the clear evidence that storing water underground also purges it of disease-causing organisms, making it clean enough to recycle as irrigation.

Weve been studying the behaviour and fate of various microbes in groundwater taken from different parts of the country, he explains.

Weve looked at enteric (gut) viruses, the protozoan Cryptosporidium, and disease-causing bacteria like Salmonella and Aeromonas.

If we are to store large volumes of water underground for recycling, we need to know exactly what happens with these bugs, and whether they can survive in reclaimed water.

Once underground, the disease-causing organisms face a hostile array conditions such as temperature changes, lack of oxygen, lack of nutrients and a whole army of naturally occurring groundwater microorganisms that kill or inactivate them.
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Contact: Simon Toze
Simon.toze@csiro.au
61-8-93336-130
CSIRO Australia
6-Mar-2002