A measure of Australia’s chronic shortage of water and low soil fertility is the repeated demand for more dams and irrigation and for the payment of a phosphate bounty. Yet we squander vast quantities of both water and mineral nutrients (including phosphates) by our wasteful disposal of sewage. Instead of forward planning for the long-term use of an available agricultural asset, we follow the short-term, politically expedient policy of easy disposal of sewage. This frequently results in excessive growth of unwanted plants in and around the water into which the waste is discharged.
Possibly, our coastal cities are not suitably situated for agricultural use of sewage because piping and treatment areas are very expensive in these zones. In an area of usually moderate rainfall, such as Gosford, even the recycling of nutrients from sewage would leave more residual clean water that the district can use. It is ironic that this district has suffered lately from severe water restrictions! In these places fuel (possibly methane generation) seems a more reasonable use of sewage. However, in the country west of the Dividing Range, the volume of sewage, the level of the land and the usually low output of industrial waste make agricultural usage relatively simple. The supply seems inexhaustible and almost unaffected by drought. To see the end of water shortages, such as have been in evidence in some areas in 1978-81, would be most welcome in these districts. Installation, not replacement, would be the main cost.