Each year Australians produce 5 to 10 billion litres of valuable urine - as much as 500 litres per person per year. And we use ten times this amount of water to carry the urine to treatment plants and into rivers and oceans. It saves water, recycles nutrients, and minimises the risk of faecal contamination. Dr Leeming says that the new system comes from a Swedish application of an Australian environmental research technique, which assesses the hygiene risks of recycling urine. Dr Leeming explains that the urine is piped off to holding tanks, from which farmers later pump it into tankers for use on the farm.
Faecal matter is collected and stored separately and composted in special bins.
Composting proceeds far more rapidly without the urine and the resulting organic matter is used as a soil improver. Groundwater still needs to be monitored periodically for excess salinity and nitrate content, just as it should be when recycling whole sewage effluents. The joint Swedish-Australian findings are soon to be published in the international research journal 'Water Research'. It may also have application in Australia's National Parks and Reserves as an alternative to existing systems of wastewater disposal in fragile environments. Dr Leeming says he expects the next stage of the Swedish project will be the development of a range of systems, supporting single households and isolated locations such as National Parks, up to communities of 12 to 20 families.